Sun Microsystems SunSoft Pascal 4.0 User's Guide
تبلیغات
تبلیغات
Pascal 4.0 User’s Guide
A Sun Microsystems, Inc. Business
2550 Garcia Avenue
Mountain View, CA 94043
U.S.A.
Part No.: 802-2943-10
Revision A, November 1995
Please
Recycle
1995 Sun Microsystems, Inc. 2550 Garcia Avenue, Mountain View, California 94043-1100 U.S.A.
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Portions of this product may be derived from the UNIX ® system and from the Berkeley 4.3 BSD system, licensed from the
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RESTRICTED RIGHTS LEGEND: Use, duplication, or disclosure by the government is subject to restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in Technical Data and Computer Software clause at DFARS 252.227-7013 and FAR 52.227-19.
The product described in this manual may be protected by one or more U.S. patents, foreign patents, or pending applications.
TRADEMARKS
Sun, the Sun logo, Sun Microsystems, Sun Microsystems Computer Corporation, Solaris, the Sun Microsystems Computer
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INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
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Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xix
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pascal Compiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
2
2
Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Text Editors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Debuggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
XView Toolkit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Native Language Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Internationalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Locale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Licensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Pascal Programs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A Simple Pascal Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
5
3
4
7
7
3
3
2
3 iii
iv
Compiling the Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Running the Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Renaming the Executable File . . . . . . . . . . . . . . . . . . . . . . . .
9
An Interactive Pascal Program . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
8
9
Compiling the Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Running the Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Redirecting I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Using a File Name as a File Variable . . . . . . . . . . . . . . . . . . .
12
Where Did My Program Fail?. . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
Using Pascal Traceback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
Using a Sample Program with Segmentation Violation . . .
14
3. The Pascal Compiler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
pc
Version Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
Compile and Link Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18
Language Preprocessor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
File Name Extensions Accepted By
pc
. . . . . . . . . . . . . . . . . . . .
20
Option-Passing on the Command-Line. . . . . . . . . . . . . . . . . . . .
21
Option-Passing in the Program Text . . . . . . . . . . . . . . . . . . . . . .
21
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23
–a
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
–B
binding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
–b
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
-bsdmalloc
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25
–C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25
Pascal 4.0 User’s Guide
Contents
–c
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
-calign
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
–cg89
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
–cg92
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
-cond
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26
–config
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27
–D
name
[=
def
]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27
–dalign
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28
-dn
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28
-dryrun
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28
-dy
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28
–fast
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28
-fnonstd
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29
–fns
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29
–fround=
r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29
–ftrap=
t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
-G
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
–g
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
–H
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
-h
name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
–help
or
-flags
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
–I
pathname . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
–i
name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
-keeptmp
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32 v
vi
–L
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
–l
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
-L
directory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
-libmieee
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
–libmil
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
–l
lib . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
–misalign
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
-mt
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
–native
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35
-nocx
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35
-nolib
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35
–nolibmil
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35
-noqueue
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35
-notrace
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36
–O[
level
]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36
–o
filename. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38
–P
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38
–p
and
–pg
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39
–pic
,
-Kpic
and
–PIC
,
-KPIC
. . . . . . . . . . . . . . . . . . . . . . .
39
–Qoption
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
–Qpath
pathname . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
–Qproduce
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
-qp
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
-R
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41
Pascal 4.0 User’s Guide
Contents
-R
path
[:
dir
]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41
-Rw
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41
–S
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46
–s[
level
]
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46
–sb
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46
–sbfast
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
46
-tc
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47
–temp=
dir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47
–tim
e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
48
–U
name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
–V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
–V0
and
–V1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
–v
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
–w
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
-xa
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
-xarch=
a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
-xcache=
c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
53
-xchip=
c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
54
-xcg89
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55
-xcg92
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55
–xF
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55
-xildoff
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56
-
xildon
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56
–xl
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56 vii
viii
-xlibmieee
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56
-xlibmil
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56
-xlibmopt
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
–xlicinfo
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
–xMerge
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
-xnolib
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
-xnolibmopt
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
-x05
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
-xpg
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
58
-xprofile=
p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
58
-xregs=
r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
60
–xs
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
61
-xsafe=mem
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
61
-xsb
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
61
-xsbfast
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
61
-xspace
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
62
-xtarget=
t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
62
–Z
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
66
-ztext
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
66
4. Program Construction and Management . . . . . . . . . . . . . . . . .
67
Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
67
Using Program Units and Module Units . . . . . . . . . . . . . . .
68
Compiling with Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
69
Using Units and Header Files . . . . . . . . . . . . . . . . . . . . . . . .
70
Pascal 4.0 User’s Guide
Sharing Variables Between Units . . . . . . . . . . . . . . . . . . . . . .
71
Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
74
5. Separate Compilation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
75
Working with Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
75
Using Program Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
76
Using Module Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
76
Sharing Variables and Routines Across Multiple Units . . . . . .
76
Compiling without the
-xl
Option. . . . . . . . . . . . . . . . . . . .
77
Using the
-xl
Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
80
Sharing Declarations in Multiple Units. . . . . . . . . . . . . . . . . . . .
87
6. The C–Pascal Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
89
Compilation of Mixed-Language Programs . . . . . . . . . . . . . . . .
89
Compatibility of Types for C and Pascal. . . . . . . . . . . . . . . . . . .
90
Precautions with Compatible Types . . . . . . . . . . . . . . . . . . .
91
Incompatibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
92
General Parameter Passing in C and Pascal . . . . . . . . . . . . . . . .
93
Procedure Calls: C–Pascal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
93
Variable Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
94
Value Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
112
Function Return Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
115
Input and Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
116
Procedure Calls: Pascal–C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
117
Variable Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
117
Value Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
129
Contents ix
x
Function Return Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
130
Parameters That Are Pointers to Procedures . . . . . . . . . . . .
131
Procedures and Functions as Parameters . . . . . . . . . . . . . . . . . .
132
Global Variables in C and Pascal . . . . . . . . . . . . . . . . . . . . . . . . .
133
File-Passing Between Pascal and C . . . . . . . . . . . . . . . . . . . . . . .
134
7. The C++–Pascal Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
137
Sample Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
137
Compatibility of Types for C++ and Pascal . . . . . . . . . . . . . . . .
138
C++ Name Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
138
Procedure Calls: C++–Pascal . . . . . . . . . . . . . . . . . . . . . . . . . . . .
138
Arguments Passed by Reference . . . . . . . . . . . . . . . . . . . . . .
139
Arguments Passed by Value . . . . . . . . . . . . . . . . . . . . . . . . . .
150
Function Return Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
152
Procedure Calls: Pascal–C++ . . . . . . . . . . . . . . . . . . . . . . . . . . . .
155
Arguments Passed by Reference . . . . . . . . . . . . . . . . . . . . . .
155
Arguments Passed by Value . . . . . . . . . . . . . . . . . . . . . . . . . .
157
Function Return Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
159
Global Variables in C++ and Pascal . . . . . . . . . . . . . . . . . . . . . . .
161
Pascal File Pointers to C++ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
162
8. The FORTRAN–Pascal Interface . . . . . . . . . . . . . . . . . . . . . . . .
163
Compiler Mixed-Language Programs . . . . . . . . . . . . . . . . . . . . .
163
Compatibility of Types for FORTRAN and Pascal. . . . . . . . . . .
164
Precautions with Compatible Types . . . . . . . . . . . . . . . . . . .
165
Incompatibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
166
Pascal 4.0 User’s Guide
General Parameter-Passing in FORTRAN and Pascal. . . . . . . .
167
Procedure Calls: FORTRAN-Pascal . . . . . . . . . . . . . . . . . . . . . . .
168
Variable Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
168
Value Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
180
Pointers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
183
Function Return Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
184
Procedure Calls: Pascal-FORTRAN . . . . . . . . . . . . . . . . . . . . . . .
185
Variable Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
186
Value Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
197
Pointers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
200
Function Return Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
201
Routines as Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
202
9. Error Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
205
Compiler Syntax Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
205
Illegal Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
205
String Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
206
Digits in Real Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
206
Replacements, Insertions, and Deletions . . . . . . . . . . . . . . .
207
Undefined or Improper Identifiers . . . . . . . . . . . . . . . . . . . .
208
Expected Symbols and Malformed Constructs . . . . . . . . . .
208
Expected and Unexpected End-of-file. . . . . . . . . . . . . . . . . .
209
Compiler Semantic Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
210
Format of the Error Diagnostics. . . . . . . . . . . . . . . . . . . . . . .
210
Incompatible Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
210
Contents xi
xii
The
scalar
Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
211
Procedure and Function Type Errors. . . . . . . . . . . . . . . . . . .
211
Scalar Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
212
Expression Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
212
Type Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
214
Unreachable Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
215
The
goto
Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
216
Uninitialized Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
216
Unused Variables, Constants, Types, Labels, and Routines 216
Compiler Panics, I/O Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
217
Runtime Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
217
10. The XView Toolkit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
221
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
221
Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
222
Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
222
Object-Oriented Programming. . . . . . . . . . . . . . . . . . . . . . . .
222
Pascal Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
223
Compiling with Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . .
224
Header Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
224
Attribute Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
225
Handles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
226
Data Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
226
Coding Fragment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
227
Conversion of C to Pascal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
227
Pascal 4.0 User’s Guide
An Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
227
Sample Translation of an XView Function to Pascal . . . . . .
229
Sample Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
230
Menu Demo Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
231
11. Math Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
233
Contents of the Math Libraries. . . . . . . . . . . . . . . . . . . . . . . . . . .
234
libm
Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
235
IEEE Support Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
236
ieee_functions()
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
237
ieee_values()
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
237
ieee_retrospective()
. . . . . . . . . . . . . . . . . . . . . . . . . . .
238
SPARC Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
238
Arithmetic Exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
239
Math Library Exception-Handling Function:
matherr()
. . . .
240
libsunmath
Support for IEEE Modes and Exceptions . . . . . .
242
Contents xiii
xiv Pascal 4.0 User’s Guide
Figures
Figure 3-1 Organization of Pascal Compilation. . . . . . . . . . . . . . . . . . . . . .
Figure 3-2 Options in Program Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
23
Figure 10-1 A Sample Class Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
223 xv
xvi Pascal 4.0 User’s Guide
Tables
Table 3-1
Table 3-2
Table 3-3
Table 3-4
Table 3-5
Table 3-6
Table 3-7
Table 3-8
Table 3-9
Table 6-1
Table 6-2
Table 6-3
Table 8-1
–xl
File Name Suffixes Recognized by Pascal . . . . . . . . . . . . . . . . .
Options That Can Be Passed in Program Text . . . . . . . . . . . . .
The -xarch Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The -xcache Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The -xchip Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The -xprofile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The -xregs Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The -xtarget Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-xtarget Expansions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C and Pascal Size and Alignment of Compatible Types . . . . .
63
90
C and Pascal Size and Alignment of Compatible Types with –xl
91
Set Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
110
Default Sizes and Alignments of Compatible Types (Pascal and
FORTRAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
165
54
59
60
62
20
21
51
53 with –xl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
165 xvii
Table 10-1 C Declarations to Pascal Declarations . . . . . . . . . . . . . . . . . . . .
228
Table 11-1 Contents of Math Libraries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
234 xviii Pascal 4.0 User’s Guide
Preface
This manual describes the Pascal 4.0 compiler from SunSoft™. The purpose of this manual is to help you begin writing and compiling Pascal programs on a
SPARCstation™.
In a previous major release, this Pascal compiler also ran on Solaris 1.x. Some features remain in the documentation as being for Solaris 1.x only.
The README file that accompanies the product contains other release-specific information,
Note – All references to Pascal in this manual refer to the Pascal 4.0 compiler unless otherwise indicated.
Operating Environment
For information on the operating environment, see the README file.
Installation
For instructions on how to install Pascal, refer to the Installing SunSoft
Developer Products (SPARC/Solaris) manual. xix
Audience
Organization
xx
This guide was prepared for software engineers who write Pascal programs on a SPARCstation. It assumes you are familiar with ISO standard Pascal and the
Solaris™ operating system.
This guide contains the following chapters:
•
Chapter 1, “Introduction,” gives basic information about the Pascal compiler and related program development tools.
•
Chapter 2, “Pascal Programs,” describes how to write, compile, and run a
Pascal program.
•
Chapter 3, “The Pascal Compiler,” describes the pc command and its options.
• Chapter 4, “Program Construction and Management,” is an introduction to how complex programs are built in Pascal.
• Chapter 5, “Separate Compilation,” describes how programs can be divided into several units, and how they are compiled and linked.
•
Chapter 6, “The C–Pascal Interface,” describes how to write programs that are partly in C and partly in Pascal.
•
Chapter 7, “The C++–Pascal Interface,” describes how to write programs that are partly in C++ and partly in Pascal.
•
Chapter 8, “The FORTRAN–Pascal Interface,” describes how to write programs that are partly in FORTRAN and partly in Pascal.
• Chapter 9, “Error Diagnostics,” describes the errors you may encounter while writing programs with Pascal.
• Chapter 10, “The XView Toolkit,” describes how to use the XView toolkit with Pascal.
•
Chapter 11, “Math Libraries,” describes how to use the libm and libsunmath functions in Pascal programs.
•
Appendix A, “Pascal Preprocessor,” describes the Pascal preprocessors, with emphasis on the nonstandard preprocessor, cppas .
Pascal 4.0 User’s Guide
• Appendix B, “Error Messages,” lists all the error messages the compiler produces.
This guide concludes with an index.
Conventions Used in This Guide
This guide contains syntax diagrams of the Pascal language in extended
Backus-Naur Formalism (BNF) notation. Here are the meta symbols:
Table P-1 BNF Meta Symbols
Meta Symbol
::=
|
(a | b)
[ a ]
{ a }
'abc '
Description
Defined as
Can be used as an alternative
Either a or b
Zero or one instance of a
Zero or more instances of a
The characters abc
The following table describes the type styles and symbols used in this guide:
Table P-2 Typographic Conventions
Typeface or
Symbol Meaning
AaBbCc123 The names of commands, files, and directories; on-screen computer output
Example
Edit your .login
file.
Use ls -a to list all files.
hostname% You have mail.
AaBbCc123 What you type, contrasted with onscreen computer output
AaBbCc123 Command-line placeholder: replace with a real name or value
AaBbCc123 Book titles, new words or terms, or words to be emphasized hostname% su
Password:
To delete a file, type rm filename .
Read the User’s Guide.
These are called class options.
You must be root to do this.
Preface xxi
Shell Prompts in Command Examples
The following table shows the default system prompt and superuser prompt for the C shell, Bourne shell, and Korn shell.
Table P-3 Shell Prompts
Shell
C shell prompt
C shell superuser prompt
Bourne shell and Korn shell prompt
Bourne shell and Korn shell superuser prompt
$
#
Prompt machine_name% machine_name#
Related Documentation
This manual is designed to accompany the following documents:
•
The Pascal 4.0 Reference Manual, which describes extensions to standard
Pascal
• The Pascal 4.0 Quick Reference, which summarizes the compiler options
Both this manual and the Pascal 4.0 Reference Manual are available in the
AnswerBook
®
system, an on-line documentation viewing tool that takes advantage of dynamically linked headings and cross-references. The Installing
SunSoft Developer Products (SPARC/Solaris) manual shows you how to install
AnswerBook.
Manual Page
Pascal 4.0 provides an on-line manual page (also known as man page), on pc (1), that describes the Pascal compiler. This document is included in the
Pascal package and must be installed with the rest of the software
Once you install the documentation, you can read about pc by entering the man command followed by the command name, as in: hostname% man pc xxii Pascal 4.0 User’s Guide
README Files
The README default directory is: /opt/SUNWspro/READMEs .
This directory contains the following files:
• A Pascal 4.0
README , called pascal , that describes the new features, software incompatibilities, and software bugs
• A floating-point white paper, “What Every Scientist Should Know About
Floating-Point Arithmetic,” by David Goldberg, in PostScript™ format. The file is called floating-point.ps
, and can be printed on any PostScriptcompatible printer that has Palatino font. It can be viewed on-line by using the imagetool command: hostname% imagetool floating-point.ps
This paper is also available in the AnswerBook system.
Other Related Documentation
Other reference material includes:
Profiling Tools
Numerical Computation Guide
Documents in Hard Copy and in AnswerBook
The following table shows what documents are on-line, in hard copy, or both:
Pascal 4.0 User’s Guide
Pascal 4.0 Reference Manual
Pascal 4.0 Quick Reference
Installing SunSoft Developer Products (SPARC/Solaris)
Profiling Tools
Title
Table P-4 Documents in Hard Copy and in AnswerBook
Hard Copy
X
X
X
X
On-Line
X (AnswerBook)
X (AnswerBook)
X (AnswerBook)
X (AnswerBook)
Preface xxiii
Table P-4 Documents in Hard Copy and in AnswerBook (Continued)
Hard Copy Title
Numerical Computation Guide
README
What Every Scientist Should Know About Floating-Point Arithmetic
On-Line
X (AnswerBook)
X (CD-ROM)
X (AnswerBook and CD-ROM) xxiv Pascal 4.0 User’s Guide
Standards
Introduction
1
This chapter gives an overview of the features of Pascal, including compatibility, internationalization, and licensing. It contains the following sections:
Standards
Pascal Compiler
Features
Compatibility
Text Editors
Debuggers
XView Toolkit
Native Language Support
Licensing page 1 page 2 page 2 page 2 page 3 page 3 page 3 page 3 page 5
Pascal is a derivative of the Berkeley Pascal system distributed with UNIX
®
4.2
BSD. It complies with FIPS PUB 109 ANSI/IEEE 770 X3.97-1983 and
BS 6192/ ISO 7185 at both level 0 and level 1.
1
2
1
Pascal Compiler
Features
Compatibility
The name of the Pascal compiler is pc . If given an argument file name ending with .p
or .pas
, pc compiles the file and leaves the result in an executable file, called a.out
by default.
Pascal includes many extensions to the standard, including the following:
• Separate compilation of programs and modules
• dbx (symbolic debugger) support
•
Optimizer support
• Multiple label , const , type , and var declarations
•
Variable-length character strings
• Compile-time initializations
• static and extern declarations
•
Different sizes of integer and real data types
• Integer constants in any base, from 2 to 16
•
Extended input/output facilities
• Extended library of built-in functions and procedures
• Universal and function and procedure pointer types
•
Direction of parameter passing: into a routine, out of a routine, or both
• Functions that return structured-type results
Note – For other release-specific information, please refer to the README file that accompanies the product release.
In general, Pascal 4.0 runs in the Solaris 2.x or above operating environment.
This product is not compatible with /usr/ucblib/libucb.a
on the Solaris
2.x environment.
Pascal 4.0 User’s Guide
1
Text Editors
The operating system provides two main editors:
• Text Editor —A window-based text editor that runs in the OpenWindows environment. Start this tool by typing textedit at the system prompt.
• vi —The standard visual display editor that offers the capabilities of both a line and a screen editor. It also provides several commands for editing programs. For example:
• The autoindent option provides white space at the beginning of a line.
• The showmatch option shows matching parentheses.
Debuggers
SunSoft offers a variety of programming tools that run in the Solaris operating environment. For debugging, the following tools are available:
• dbx —A symbolic debugger
• debugger —A window- and mouse-based version of the symbolic debugger
You can use Pascal with fix-and-continue, a debugger functionality. See the debugger documentation for details of this feature.
XView Toolkit
The XView application programmer’s interface (API) is an object-oriented and server-based user-interface toolkit for the X Window System Version 11 (X11).
It is designed for manipulating XView windows and other XView objects.
Chapter 10, “The XView Toolkit,” describes how to use XView with Pascal.
Native Language Support
Sun supports the development of applications in languages other than English.
These languages include most European languages and Japanese. As a result, you can easily switch your application from one native language to another.
This feature is known as internationalization.
Introduction 3
4
1
Internationalization
A product can support up to four levels of internationalization:
•
Level 1 —Allows native-language characters (such as the a-umlaut). This is referred to as the 8-bit clean model because the eighth bit in each byte is used to represent native-language characters.
•
Level 2 —Recognizes and displays international date and time formats, such as 26.07.90 in Italian; international decimal units, such as 1.234.567,89 in
French; and international monetary units, such as 1.234,56 Pts in Spanish.
• Level 3 —Contains support for localized messages and text presentation.
•
Level 4 —Contains Asian language support.
Pascal supports all four levels. See the Pascal 4.0 Reference Manual for a description of the date and time functions in internationalized formats.
Pascal does not allow input and output in the various international formats. If it does, it does not comply with the Pascal language standard, ANSI/IEEE
770 X3.97-1983.
For example, the standard specifies a period ( .
) as the decimal unit in the floating-point representation. Consider the following program, which prints a floating-point value: program sample(output); var r : real := 1.2; begin writeln(r); end.
When you compile and run the program on the internationalized Pascal compiler, the output is:
1.20000000000000e+00
Pascal 4.0 User’s Guide
Licensing
Locale
1
If you reset your system locale to, for example, France, and rerun the program, the output is the same. Pascal does not replace the period with a comma, the
French decimal unit.
You can change your application from one native language to another by setting the locale. For information on this and other native language support features, see the Solaris documentation on internationalization.
This compiler uses network licensing, as described in the manual, Installing
SunSoft Developer Products (SPARC/Solaris).
When you invoke the compiler, if a license is available, the compiler starts. If no license is available, your request for a license is put on a queue, and your compile job continues when a license becomes available. A single license can be used for any number of simultaneous compiles by a single user on a single machine. There are two licensing-related options:
•
-noqueue —Does not queue request if no license is available.
•
-xlicinfo —Returns information on the status of licensing.
The -xlicinfo option does not check out a license.
For details on how to obtain a license—where to call, what information to have ready—refer to the manual, Installing SunSoft Developer Products
(SPARC/Solaris).
Introduction 5
1
6 Pascal 4.0 User’s Guide
Pascal Programs
2
This chapter cites two examples that illustrate how to compile and execute a program. It also explains how to use the traceback facility to find out why a program fails. The sections are:
A Simple Pascal Program
An Interactive Pascal Program
Where Did My Program Fail?
page 7 page 10 page 13
Building a program with SPARCompiler Pascal requires three steps:
1. Writing a program in Pascal using an editor and saving it in a file with a
.p
or .pas
suffix
2. Compiling the .p
or .pas
file using the pc command
3. Executing the program by typing the name of the executable file at the system prompt
A Simple Pascal Program
The following is a simple Pascal program that converts temperatures from
Fahrenheit to Celsius. Use an editor to type the code on your system and save it in a file called temp.p
.
7
2 program temperature(output) ;
{ Program to convert temperatures from
Fahrenheit to Celsius. } const
MIN = 32 ;
MAX = 50 ;
CONVERT = 5 / 9 ; var fahren: integer ; celsius: real ; begin writeln('Fahrenheit writeln('----------
Celsius') ;
-------') ; for fahren := MIN to MAX do begin celsius := CONVERT * (fahren - 32) ; writeln(fahren: 5, celsius: 18: 2) ;
end ; end.
Compiling the Program
Now compile the program with pc , the Pascal compiler, by typing at the system prompt: hostname% pc temp.p
Pascal names the compiled version of the program a.out
by default.
8 Pascal 4.0 User’s Guide
2
Running the Program
To run the program, enter a.out
at the prompt. The output of temp.p
is then displayed: hostname% a.out
Fahrenheit Celsius
---------- -------
32 0.00
33
34
35
36
0.56
1.11
1.67
2.22
41
42
43
44
37
38
39
40
2.78
3.33
3.89
4.44
5.00
5.56
6.11
6.67
45
46
47
48
49
50
7.22
7.78
8.33
8.89
9.44
10.00
Renaming the Executable File
It is inconvenient to have the result of every compilation in a file called a.out
.
If such a file already exists, it is overwritten. You can avoid this in either of the two following ways:
• Change the name of a.out
after each compilation with the mv command: hostname% mv a.out temp
• Use the compiler –o option to name the output executable file. This example places the executable code in the file temp : hostname% pc –o temp temp.p
Pascal Programs 9
2
Now run the program by typing the name of the executable file. The output follows: hostname% temp
Fahrenheit Celsius
---------- -------
32 0.00
.
.
33
34
.
0.56
1.11
.
.
.
An Interactive Pascal Program
In Pascal, the predefined file variable, input , is equivalent to the operating system standard input file, stdin . Similarly, the file variable, output , is equivalent to the standard output file, stdout .
Following is a Pascal program that copies input to output . Use an editor to type the code on your system and store it in a file called copy.p
: program copy(input, output);
{ This program copies input to output. } var
c: char; begin
while not eof do begin
while not eoln do begin
read(c);
write(c)
end;
readln;
writeln
end end. { copy }
10 Pascal 4.0 User’s Guide
2
Compiling the Program
Use the pc command to compile the program and store it in the executable file copy . Here is the command format: hostname% pc -o copy copy.p
Running the Program
Because the standard files input and output default to the terminal, the program simply echoes each line you type. The program terminates when you type the end-of-file (Control-d) character at the beginning of a line. Try it: hostname% copy hello, are you listening?
hello, are you listening?
goodbye, I must go now.
goodbye, I must go now.
(Control-d)
Redirecting I/O
To write the output to a file instead of to the terminal, use the redirection operator, > , followed by a file name. For instance, to write to a file called data , enter the following: hostname% copy > data hello, are you listening?
goodbye, I must go now.
(Control-d)
Pascal Programs 11
12
2
Using the same program, but with the < operator to redirect input, you can print the file on the terminal: hostname% copy < data hello, are you listening?
goodbye, I must go now.
Using a File Name as a File Variable
You can also redirect the output by listing the file as a file variable in the program statement. The Pascal library associates the file variable with a file of the same name. For example, copy2.p
lists data as the input file variable: program copy2(data, output);
{ This program redirects input. } var
c: char;
data: text; begin
reset(data);
while not eof(data) do begin
while not eoln(data) do begin
read(data, c);
write(c)
end;
readln(data);
writeln
end end. { copy2 }
Pascal 4.0 User’s Guide
2
Assuming that the file data is still in the current directory, you can compile and run the program as follows: hostname% pc -o copy2 copy2.p hostname% copy2 hello, are you listening?
goodbye, I must go now.
Where Did My Program Fail?
SPARCompiler Pascal can trace why a program failed; its traceback utility finds the routine that triggers the error.
Using Pascal Traceback
Pascal traceback installs signal handlers on selected signals and dumps a backtrace when those signals are caught. The backtrace shows the chain of calls leading from the routine in which the error occurred, all the way back to the main program.
Pascal catches the following set of signals:
SIGQUIT
SIGILL
SIGTRAP
SIGIOT
SIGABRT
SIGEMT
SIGFPE
SIGBUS
SIGSEGV
SIGSYS
SIGPIPE
SIGTERM
SIGLOST
See the signal (3) man page for further information on these signals.
After the system produces the traceback, it continues with whatever action it would have taken if the interposer had not been in place, including calling a user signal handler that was previously set.
The traceback facility uses the debugger dbx . To obtain a traceback,
SPARCworks must be installed on your system, and the directory containing dbx must be in your PATH environment variable. If the traceback routine cannot find dbx , it does not produce the traceback.
Use the -notrace command-line option to disable traceback.
Pascal Programs 13
2
14
Using a Sample Program with Segmentation Violation
A segmentation violation occurs when your program tries to reference memory outside your address space. The operating system detects this action and generates an error message. Following is an example program, SegViol.p
, which contains a segmentation violation: program SegmentationViolation; type
Pinteger = ^integer; procedure ErrorInHere; var
IntVar: integer;
NullPtr: Pinteger; begin
NullPtr := nil;
{ Next statement causes a SEGV }
IntVar := NullPtr^; end; procedure Call1;
procedure Call2;
begin
ErrorInHere;
end; begin
Call2; end; begin
Call1; end.
Compiling and Running the Program
When you compile and run the program, you receive output similar to the following. The first line indicates the name of the offending signal—in this case, a segmentation violation.
Pascal 4.0 User’s Guide
2 hostname% pc SegViol.p hostname% a.out
*** a.out terminated by signal 11: segmentation violation
*** Traceback being written to a.out.trace
Abort (core dumped) hostname% more a.out.trace
*** Stacktrace of a.out
*** Program terminated due to segmentation violation
[3] __PC0__sigdie(0xb, 0xefffedf0, 0xefffec30, 0x0, 0x1, 0x0), at 0x12128
---- called from signal handler with signal 11 (SIGSEGV) ------
[4] ErrorInHere(), at 0x115ec
[5] Call2(0xefffefc8, 0xefffefa8, 0xefffef88, 0x0, 0xef74dd58, 0x0), at 0x11624
[6] Call1(0x25400, 0x25800, 0x25b80, 0x25b80, 0x3, 0x0), at 0x11660
[7] program(0x1, 0xeffff0fc, 0x4, 0xef7d0000, 0x2, 0xef74dae8), at 0x116a4
[8] main(0x1, 0xeffff0fc, 0xeffff104, 0x25000, 0x0, 0x0), at 0x116e0 detaching from process 17266
In this example, ErrorInHere reported the error. The ErrorInHere procedure was called by Call1.Call2
, which was in turn called by the main program. Routine names, such as Call1.Call2
, indicate a nested routine. If
Pascal cannot find the name of a routine, for example, because the executable file has been stripped, it prints the hex address.
Using the
-g
Option
If you compile the program with the –g option, the traceback also reports the arguments, the line number, and the file name of each routine.
Pascal Programs 15
2
Try compiling SegViol.p
with –g : hostname% pc -g SegViol.p hostname% a.out
*** a.out terminated by signal 11: segmentation violation
*** Traceback being written to a.out.trace
Abort (core dumped) hostname% more a.out.trace
*** Stacktrace of a.out
*** Program terminated due to segmentation violation
[3] __PC0__sigdie(0xb, 0xefffedf0, 0xefffec30, 0x0, 0x1, 0x0), at 0x12128
---- called from signal handler with signal 11 (SIGSEGV) ------
[4] ErrorInHere(), line 12 in “SegViol.p”
[5] Call2(), line 18 in "SegViol.p"
[6] Call1(), line 21 in "SegViol.p"
[7] program(), line 25 in "SegViol.p" detaching from process 17285
The program prints the ASCII values of character variables.
If you compile some modules with –g and others without, the line numbers may not be accurate for all the routines.
16 Pascal 4.0 User’s Guide
The Pascal Compiler
3
The name of the Pascal compiler is pc . If you give pc a file name as an argument, and the file name ends with .p
or .pas
, pc compiles the file and leaves the result in an executable file, called a.out
by default.
The syntax of this command is: pc [ options ] filename
This chapter contains the following sections: pc Version Number
Compile and Link Sequence
Language Preprocessor
File Name Extensions Accepted By pc
Option-Passing on the Command-Line
Option-Passing in the Program Text
Options page 17 page 18 page 19 page 20 page 21 page 21 page 23
pc Version Number
To identify the version number of pc when you compile your program, call the compiler with the –V option. This option instructs the compiler to produce output that identifies the versions of all the programs used in compiling, the compiler itself, the code generator, and so on.
17
3
To identify the version number given an executable or object file created by the
Pascal compiler, use the following command.
hostname% mcs -p a.out | grep Pascal
SC4.0 18 Mar 1995 Pascal 4.0
Compile and Link Sequence
You can compile the file any.p
with the following command-line: hostname% pc any.p
This command actually invokes the compiler driver, which calls several programs or passes of the program, each of which processes the program. The output of each pass is the input to the next one.
After several passes, the object file any.o
is created. An executable file is then generated with the default name a.out
. Finally, the file any.o
is removed.
pc calls:
• cpp , the C preprocessor or cppas , the preprocessor used when you use the
-xl option
• pc0 , the Pascal front end
• The global optimizer if you use the -O option
• cg , the code generator, which generates the relocatable object file
• pc3 , which checks for conflicts in symbol names
• ld , the linker, which generates the executable files using any libraries necessary to resolve undefined symbols
The above is the default action of pc ; some compiler options change what pc calls.
18 Pascal 4.0 User’s Guide
Figure 3-1 shows the sequence of events when you invoke pc .
Compiler pc
Source and include files
Compiler preprocessor cpp or cppas
Compiler frontend pc0
Optimize with
-O[ level ] option
Optimizer iropt
Code generator cg
Symbol conflict checking pc3
Link editor ld
Executable a.out
3
Libraries
Figure 3-1 Organization of Pascal Compilation
Language Preprocessor
The cpp (1) program is the C language preprocessor. The compiler driver pc normally calls cpp (1) during the first pass of a Pascal compilation. If you use the –xl switch, pc calls the alternate preprocessor cppas . Then cpp (1) and cppas operate on files that contain the extension .p
or .pas
.
You can give directives to cpp (1) or cppas to define constants, conditionally compile parts of your program, include external files, and take other actions.
For example, the following program shows the use of an include directive, which asks cpp (1) to copy the named file into the program before compilation.
The Pascal Compiler 19
3 program showinclude;
#include "file.i" begin
...
end.
See the man page for cpp (1) for information on its directives and other features. Appendix A, “Pascal Preprocessor,” describes cppas .
File Name Extensions Accepted By pc
Pascal source files generally use the extension .p
. The compiler recognizes other file name extensions. Table 3-1 lists the most important extensions.
The table notes that pc can produce assembler source files as well as unlinked object files. In each case, you can pass these partially compiled files to pc , which then finishes the compilation, linking, and loading.
Table 3-1 File Name Suffixes Recognized by Pascal
.p
Suffix
.pas
.pi
.s
.o
Description
Usual extension for Pascal source files.
Valid extension for a Pascal source file. The extension instructs pc to put object files in the current directory. The default name of the object file is the name of the source file, but with a .o
suffix.
Default extension for Pascal source files that have been processed by the Pascal preprocessor (either cpp or cppas ).
Extension for assembler source files that are produced when you call pc with the -S option.
Extension for object files that are generated by the compiler when you call pc with the -c option.
20 Pascal 4.0 User’s Guide
3
Option-Passing on the Command-Line
To pass an option on the command-line, use a dash ( ) followed by the option name. In some cases, you must supply additional information, such as a file name. For example, this command activates the listing option -l , which is off by default: hostname% pc -l rmc.p
The following command causes the generated object file to be named rmc instead of the default, a.out
.
hostname% pc -o rmc rmc.p
Option-Passing in the Program Text
Some options can be passed to the compiler in program text as well as on the command-line. With this facility, you can use different option values for different parts of a program.
Here are four examples of how options can be passed in program text:
{$P+}
{$H*}
(*$I-*)
{$l+,L-,n+}
Table 3-2 shows the options that can be passed in program text.
Table 3-2 Options That Can Be Passed in Program Text
Option Description b
C
Uses buffering of the file output.
Uses runtime checks (same as t ).
calign Uses C data formats.
H Uses check heap pointers.
l
L p
Makes a listing.
Maps identifiers and keywords to lowercase.
Uses statement limit counting (different from command-line p
1
). See stlimit in the Pascal 4.0 Reference Manual.
The Pascal Compiler 21
3
22
Table 3-2 Options That Can Be Passed in Program Text (Continued)
Option
P t u w
Uses partial evaluation of boolean expressions.
Uses runtime checks (same as C, but different from the command-line t
1
).
Trims to 72-character line (not usable on command-line).
Prints warning diagnostics.
Description
1. The options p and t are different when they are used within program text and when they are used on the command-line because they are received directly by pc0 when they are used in program text, while the compiler driver gives them to other compiler passes when they are given on the command-line. If you want to set them on the command-line and also want them to have the same effect as passing them in program text, use the Qoption command-line option to pass them directly to pc0 .
You set options within comments, which can be delimited by either { and } or
(* and *) . The first character in the comment must be the $ (dollar sign).
$ must be immediately followed by an option letter. Next must be either + , , or
* .
If you want to set more than one option, you can insert a comma after the first option, followed by another option letter and + , , or * . You can set any number of options on a single line. There must be no embedded spaces. You can place spaces and other ordinary comment text after the last + , , or * .
The new option setting takes effect at the next noncomment token.
The symbols + (plus sign) and (minus sign) turn the option on and off, respectively. To understand the symbol * , you must know how options work in Pascal.
Except for b , each option in Table 3-2 has a current value and a “first in, last out” stack of up to 16 values. Again, except for b , each option can be on or off.
When you begin compiling a program, each stack is empty and each option has an initial current value, which may be the option default value or may have been set on the command line.
Pascal 4.0 User’s Guide
3
When the compiler encounters an option followed by...
+
-
*
This is what happens...
The current value is pushed onto the stack, and the current value becomes ON.
The current value is pushed onto the stack, and the current value becomes OFF.
The last value is popped off the stack and becomes the current value.
If no values have been pushed onto the stack, the effect of * is undefined.
Figure 3-2 illustrates how options are passed in program text.
Program: program options (output); begin
{$l+ Turns on listing} writeln ('After $l-');
{$l- Turns off listing}
{Notice that this line prints.} writeln ('After $l+');
{$l* Turns listing on again}
{Notice that this line does not print.} end.
writeln ('After $l*')
Output: hostname% pc options.p
Fri Mar 1 17:33:18 1995 options.p:
4 writeln ('After $l-');
5 {$l- Turns off listing}
6 {Notice that this line prints.}
10 writeln ('After $l*')
11 end.
Figure 3-2 Options in Program Text
Options
This section describes all the pc command options in alphabetical order.
Unless otherwise stated at the beginning of the description for the option, all of these options work for both the Solaris 1.x and Solaris 2.x environments.
In general, processing of the compiler options is from left to right, so selective overriding of macros can be done. This rule does not apply to linker options.
The Pascal Compiler 23
3
24
–a
The –a option is the old style of basic block profiling for tcov . See
-xprofile=tcov for information on the new style of profiling and the tcov (1) man page for more details. Also see the manual, Profiling Tools.
The –a option inserts code to count how many times each basic block is executed. It also calls a runtime recording mechanism that creates a .d
file for every .p
file at normal termination. The .d
file accumulates execution data for the corresponding source file. The tcov (1) utility can then be run on the source file to generate statistics about the program.
If set at compile-time, the TCOVDIR environment variable specifies the directory of where the .d
files are located. If this variable is not set, then the
.d
files remain in the same directory as the .f
files.
The -xprofile=tcov and the -a options are compatible in a single executable. That is, you can link a program that contains some files which have been compiled with -xprofile=tcov , and others with -a . You cannot compile a single file with both options.
–B binding
The –B option specifies whether libraries for linking are static (not shared, indicated with -Bstatic ), or dynamic (shared, indicated with -Bdynamic ).
Link editing is the set of operations necessary to build an executable program from one or more object files. Static linking indicates that the results of these operations are saved to a file. Dynamic linking refers to these operations when performed at runtime. The executable that results from dynamic linking appears in the running process, but is not saved to a file.
–b
It is inefficient for Pascal to send each character to a terminal as it generates its output. It is even less efficient if the output is the input of another program, such as the line printer daemon, lpr (1).
To gain efficiency, Pascal buffers output characters; it saves the characters in memory until the buffer is full and then outputs the entire buffer in one system interaction. By default, Pascal output is line-buffered.
Pascal 4.0 User’s Guide
3
The –b option on the command-line turns on block-buffering with a block size of 1,024. You cannot turn off buffering from the command-line.
If you give the –b option in a comment in the program, you can turn off buffering or turn on block buffering. The valid values are:
{$b0}
{$b1}
{$b2}
No buffering
Line buffering
Block buffering. The block size is 1,024.
Any number greater than 2 (for example, {$b5} ) is treated as {$b2} . You can only use this option in the main program. The block buffering value in effect at the end of the main program is used for the entire program.
-bsdmalloc
(Solaris 1.x only) The -bsdmalloc option specifies faster malloc and uses the more efficient malloc from the library, libbsdmalloc.a
. This option also causes the flags, -u _malloc /lib/libbsdmalloc.a
, to be passed to the linker.
–C
The –C option enables runtime checks that verifies that:
•
Subscripts and subranges are in range.
• The number of lines written to output does not exceed the number set by the linelimit procedure. (See the Pascal 4.0 Reference Manual for information on linelimit .)
• Overflow, underflow, and divide-by-zero do not exist.
•
The assert statement is correct. (See the Pascal 4.0 Reference Manual for information on assert .)
If you do not specify –C , most runtime checks are disabled, and pc treats the assert statement as a comment and never uses calls to the linelimit procedure to halt the program. However, divide-by-zero checks are always made.
The –V0 and –V1 options implicitly turn on –C .
The Pascal Compiler 25
26
3
–c
-calign
The -calign option instructs the compiler to allocate storage in records the same way as the C compiler allocates structures. See the Pascal 4.0 Reference
Manual for details of how data is aligned with and without -calign .
You can use calign within a program as well as on the command-line.
However, calign only has an effect in the type and var sections of the program. Any types you define when calign is on use C-style alignment whenever you define variables of that type.
–cg89
The –c option instructs the compiler not to call the linker, ld (1). The Pascal compiler, pc , leaves a .o
or object file for each source file. Without –c , pc calls the linker when it finishes compilation, and produces an executable file, called a.out
by default.
(Solaris 1.x only) The –cg89 option generates code to run on generic SPARC architecture.
(Solaris 2.x only) This option is a macro for:
-xarch=v7 -xchip=old -xcache=64/32/1 .
–cg92
(Solaris 1.x only) The –cg92 option generates code to run on SPARC V8 architecture.
(Solaris 2.x only) This option is a macro for:
-xarch=v8 -xchip=super -xcache=16/64/4:1024/64/1
-cond
You can only use this option when you also use the -xl option.
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The –cond option instructs pc to compile the lines in your program that begin with the %debug compiler directive. If you compile your program without
–cond , pc treats lines with the %debug directive as comments.
–xl runs your program through the preprocessor cppas , which handles the
Apollo DOMAIN ®
-style Pascal compiler directives, such as %debug .
See Appendix A, “Pascal Preprocessor,” for a complete description of conditional variables, cppas , and compiler directives.
–config
You can only use this option when you also use the -xl option.
The –config option sets a conditional variable to true . You can only use this option when you use the preprocessor cppas , which is invoked when you use the -xl option.
Pascal supports the –config option with only one value. For example, Pascal accepts –config one , but not –config one two . To specify more than one variable, use multiple –config options on the command-line.
If you use -config but do not give a variable, the value of the predefined conditional variable %config is set to true .
–xl runs your program through the preprocessor cppas , which handles the
Apollo DOMAIN -style Pascal compiler directives, such as %config .
See Appendix A, “Pascal Preprocessor,” for a complete description of conditional variables, cppas , and compiler directives.
–D name [= def ]
The –D option defines a symbol name to the C preprocessor, cpp . It is equivalent to using the #define statement in your program. If you do not include a definition, name is defined as 1. See cpp (1) for more information.
If you use this option with the -xl option, -D is equivalent to using the
%config directive in your program.
The Pascal Compiler 27
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28
–dalign
The – dalign option instructs the compiler to generate double load and store instructions wherever possible for faster execution. All double-typed data become double-aligned, so do not use this option when correct alignment is not ensured.
-dn
(Solaris 2.x only) The -dn option specifies static linking in the link editor.
-dryrun
The –dryrun option instructs the compiler to show, but not execute, the commands constructed by the compilation driver. You can then see the order of execution of compiler passes without actually executing them.
-dy
(Solaris 2.x only) The -dy option specifies dynamic linking in the link editor.
–fast
(Solaris 1.x only) The –fast option selects optimum compilation options for speed and provides close to the maximum performance for most realistic applications. A convenience option, it chooses the fastest code generation option available on the compile-time hardware, the optimization level -02 , the
-dalign option, and a set of inline expansion templates. If you combine fast with other options, the last specification applies.
(Solaris 2.x only) The -fast option includes -fns -ftrap=%none ; that is, it turns off all trapping. In previous releases, the -fast macro option included
-fnonstd; now it does not.
-fast includes -native in its expansion.
The code generation option, the optimization level, and using inline template files can be overridden by subsequent switches. For example, although the optimization part of -fast is -O2 , the optimization part of -fast -03 is -03 .
Pascal 4.0 User’s Guide
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Do not use this option for programs that depend on IEEE standard exception handling; you can get different numerical results, premature program termination, or unexpected SIGFPE signals.
Note – The criteria for the -fast option vary with the compilers from SunSoft:
C, C++, FORTRAN 77, Fortran 90, and Pascal. See the appropriate documentation for the specifics.
-fnonstd
The -fnonstd option causes nonstandard initialization of floating-point arithmetic hardware. By default, IEEE 754 floating-point arithmetic is nonstop, and underflows are gradual. (See the Numerical Computation Guide for details.)
The –fnonstd option causes hardware traps to be enabled for floating-point overflow, division by zero, and invalid operation exceptions. These hardware traps are converted into SIGFPE signals, and if the program has no SIGFPE handler, it terminates with a memory dump.
-fnonstd also causes the math library to be linked in by passing -lm to the linker.
(Solaris 2.x only) This option is a synonym for -fns -ftrap=common .
–fns
(Solaris 2.x only) The -fns option turns on the SPARC non-standard floatingpoint mode.
The default is the SPARC standard floating-point mode.
If you compile one routine with -fns , then compile all routines of the program with the –fns option; otherwise, unexpected results may occur.
–fround= r
(Solaris 2.x only) The -fround= r option sets the IEEE 754 rounding mode that is established during program initialization.
r must be one of: nearest , tozero , negative , positive .
The Pascal Compiler 29
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3
The default is -fround=nearest .
The meanings are the same as those for the ieee_flags subroutine.
If you compile one routine with -fround= r, compile all routines of the program with the same –fround= r option; otherwise, unexpected results may occur.
–ftrap= t
(Solaris 2.x only) The -ftrap= t option sets the IEEE 754 trapping mode in effect at startup.
t is a comma-separated list of one or more of the following: %all , %none , common , [ no% ] invalid , [ no% ] overflow , [ no% ] underflow , [ no% ] division ,
[ no% ] inexact . The default is -ftrap=%none .
This option sets the IEEE 754 trapping modes that are established at program initialization. Processing is left-to-right. The common exceptions, by definition, are invalid, division by zero, and overflow.
Example: -ftrap=%all,no%inexact means set all traps, except inexact .
The meanings are the same as for the ieee_flags function, except that:
•
%all turns on all the trapping modes.
•
%none , the default, turns off all trapping modes.
• A no% prefix turns off that specific trapping mode.
If you compile one routine with -ftrap= t, compile all routines of the program with the same -ftrap= t option; otherwise, unexpected results may occur.
-G
(Solaris 2.x only) The -G option builds a shared library. All object files specified with this command option should have been compiled with either the -pic or the -PIC option.
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–g
The –g option instructs pc to produce additional symbol table information for dbx and debugger . With -g , the incremental linker, ild , is called, instead of ld .
You can compile using both the -g and -O options. However, there are some side effects:
• The next and step commands do not work, but the cont command does.
•
If you have makefiles that rely on -g overriding -O , you must revise those files.
•
If you have makefiles that check for a warning message that -g overrides
-O , you must revise those make files.
Note – Special case: -04 -g . The combination -04 -g turns off inlining that you usually get with -04 .
–H
The –H option instructs pc to compile code to perform range-checking on pointers into the heap. This option is implicitly turned on by the –V0 and –V1 options.
-h name
(Solaris 2.x only) The -h name option names a shared dynamic library and provides a way to have versions of a shared dynamic library.
This is a loader option, passed to ld . In general, the name after -h should be exactly the same as the one after -o . A space between the -h and name is optional.
The compile-time loader assigns the specified name to the shared dynamic library you are creating. It records the name in the library file as the intrinsic name of the library. If there is no -h name option, then no intrinsic name is recorded in the library file.
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–help or -flags
The –help or -flags option lists and summarizes all available options.
–I pathname
The –I option gives the preprocessor additional places to look for #include and %include files. For example, hostname% pc -I/home/incfiles -I/usr/incfiles program.p
The preprocessor searches for #include and %include files in this order:
1. In /opt/SUNWspro/SC4.0/include/pascal
2. In the directory containing the source file, except when you use the
#include < file > form, in which case this directory is not searched
3. In directories named with –I options, if any, in left to right order
4. In /usr/include
–i name
Every executable file has a list of needed shared library files. When the runtime linker links the library into an executable file, the linker copies the intrinsic name from the library into that list of needed shared library files. If there is no intrinsic name of a shared library, then the linker copies the path of the shared library file instead.
The –i option produces a listing for the specified procedure, function,
#include , or %include file. For example, this command instructs the compiler to make a listing of the routines in the file scanner.i
.
hostname% pc –i scanner.i program.p
See cpp (1), or Chapter 4, “Program Construction and Management,” or
Chapter 5, “Separate Compilation,” for information on include files.
-keeptmp
The -keeptmp option keeps temporary files that are created during compilation, so they are retained instead of being deleted automatically.
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–L
The –L option maps all keywords and identifiers to lowercase. In Pascal, uppercase and lowercase are not interchangeable in identifiers and keywords.
In standard Pascal, the case is insignificant outside of character strings and character constants. The –L option is most useful for transporting programs from other systems. See also the –s option.
–l
The –l option produces a listing of the program. For example: hostname% pc -l random.p
Pascal PC -- Version SC4.0 09 Jan 1995 Pascal 4.0
Mon Jan 09 09:04 1995 random.p:
1 program random_number(output);
2
4
5
6 var i: integer; x: integer;
7
8
9
10
11
12 begin for i := 1 to 5 do begin
write(trunc(random(x) * 101)) end; writeln end.
The first line identifies the version of the compiler you are using. The next line gives the modification time of the file being compiled. The remainder of the listing is the source program.
-L directory
The -L directory option adds directory to the ld library search path for ld .
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-libmieee
Forces IEEE 754 style return values for math routines in exceptional cases. In such cases, no exception message is printed, and errno is not set.
–libmil
The –libmil option instructs the compiler to select the best inline templates for the floating-point option and operating system release available on this system.
–l lib
The –l lib option links ld (1) with the object library, lib.
Do not use the -lucb option because Pascal is not compatible with the object library, libucb .
–misalign
The –misalign option allows for misaligned data in memory. Use this option only if you receive a warning message that your data is misaligned.
With the –misalign option, pc generates much slower code for references to formal parameters. If possible, recode the indicated section instead of recompiling your program with this option.
-mt
The -mt option uses multithread-safe libraries, eliminates conflicts between threads, so that Pascal library routines can be safely used in a multiprocessing environment.
The MT-safe library for Pascal is called libpc_mt .
On a single-processor system, the code that is generated with this option runs more slowly; the degradation in performance is usually insignificant, however.
Refer to the Multithreaded Programming Guide in the Solaris documentation for more information.
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–native
The –native option causes pc to generate code for the best floating-point hardware available on the machine you are compiling on.
The -fast macro includes -native in its expansion.
(Solaris 2.x only) This option is a synonym for -xtarget=native .
-nocx
(Solaris 1.x only) The -nocx option makes the output executable file about
128K bytes smaller by not linking with the -lcx option. However, the runtime performance and accuracy of binary-decimal base conversion is somewhat compromised.
-nolib
The -nolib option instructs the compiler not to link any libraries by default—that is, no -l options are passed to ld . Normally, the pc driver passes -lc to ld .
When you use -nolib , pass all -l options yourself. For example, the following command links libm statically and the other libraries dynamically: hostname% pc -nolib -Bstatic -lm -Bdynamic -lc test.p
–nolibmil
The –nolibmil option instructs the compiler to reset –fast so that it does not include inline templates. Use this option after the –fast option, as in: hostname% pc –fast –nolibmil myprog.p
-noqueue
The -noqueue option instructs the compiler not to queue this compilation if a license is not available. Under normal circumstances, if no license is available, the compiler waits until one becomes available. With this option, the compiler returns immediately.
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-notrace
The -notrace option disables runtime traceback. It is only effective when compiling the main program.
–O[ level ]
The –O option instructs the compiler to run the compiled program through the object code optimizer. The –O option also calls the –P option, which ensures boolean expressions are only evaluated as much as needed to determine the result. This process causes an increase in compile time in exchange for a decrease in compiled code size and execution time.
There are four levels of optimization. You indicate the level by specifying a digit from 1 to 4 after the –O option. If you leave out the digit, the optimization level defaults to –O2 .
The level numbers are interpreted as follows:
–O
This is the most likely level of optimization to give fastest performance for most reasonable applications. The default is –O2 .
–O1,-xO1
This is the minimum amount of optimization (peephole) and is postpass assembly-level. Do not use –O1 unless -O2 and -O3 result in excessive compilation time or shortage of swap space.
–O2 , -xO2
This is the basic local and global optimization—induction-variable elimination, local and global common subexpression elimination, algebraic simplification, copy propagation, constant propagation, loopinvariant optimization, register allocation, control-flow optimization, tail-recursion elimination, dead-code elimination, and tail-call elimination.
Level -O2 does not optimize references to or definitions of external or indirect variables. This level is the appropriate level for device drivers and programs that modify external variables from within signal handlers.
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–O3 , -xO3
Same as -O2 , but optimizes the uses and definitions of external variables.
Level -O3 does not trace the effects of pointer assignments. Do not use
Level -O3 when compiling device drivers or programs that modify external variables from within signal handlers.
–O4 , -xO3
Same as -O3 , but traces the effects of pointer assignments and gathers alias information. Do not use Level -O4 when compiling device drivers or programs that modify external variables from within signal handlers.
-O5 , -xO5
(Solaris 2.x only) Generates the highest level of optimization. This level uses optimization algorithms that take more compilation time or that do not have as high a certainty of improving execution time.
Optimization at this level is more likely to improve performance if it is done with profile feedback. See -xprofile .
Note – Levels -O3 and -O4 may result in an increase in the size of the executables. When optimizing for size, use level -O2 . For most programs ,
–O4 is faster than –O3 , which is faster than –O2 , which is faster than –O1 .
However, in a few cases –O2 may be faster than the others, and –O3 may be faster than –O4 . You can try compiling with each level to see if you have one of these rare cases.
If the optimizer runs out of memory, it tries to recover by retrying the current procedure at a lower level of optimization, then resumes subsequent procedures at the original level specified in the –O command-line option.
If you optimize at –O3 or –O4 with very large procedures (thousands of lines of code in a single procedure), the optimizer may require an unreasonable amount of memory. Such cases may result in degraded machine performance.
You can prevent this from happening in the C shell by limiting the amount of virtual memory available to a single process. To do this, use the limit command (see csh (1)).
For example, to limit virtual memory to 16 megabytes: hostname% limit datasize 16M
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This command causes the optimizer to try to recover if it reaches 16 megabytes of data space.
This limit cannot be greater than the machine’s total available swap space, and in practice, should be small enough to permit normal use of the machine while a large compilation is in progress. For example, on a machine with 32 megabytes of swap space, the command limit datasize 16M ensures that a single compilation never consumes more than half of the machine’s swap space.
The best setting of data size depends on the degree of optimization requested and the amount of real memory and virtual memory available. To find the actual swap space: hostname% /usr/sbin/swap -s
To find the actual real memory: hostname% /usr/sbin/prtconf | grep Memory
–o filename
The –o option instructs the compiler to name the generated executable,
filename. The default file name for executable files is a.out
; for object files, it is the source file name with a .o
extension. For example, the following command stores the executable in the file, myprog : hostname% pc -o myprog myprog.p
If you use this option with the -c option, the name you give is used as the name for the object file. The default file name for object files is the source file name with a .o
extension. You cannot give the object file the same name as the source file.
–P
The –P option causes the compiler to use partial evaluation semantics on the boolean operators, and and or . Left-to-right evaluation is guaranteed, and the second operand is evaluated only if necessary to determine the result.
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–p and –pg
The –p and –pg options instruct the compiler to produce code that counts the number of times each routine is called. The profiling is based on a periodic sample taken by the system, rather than by line counters.
Using the
-p
Option
To generate an execution profile using the –p option:
1. Compile with the –p option.
2. Run a.out
, which produces a mon.out
executable file.
3. Type prof a.out
. The program prints a profile.
Using the
-pg
Option
To generate an execution profile using the –pg option:
1. Compile with the –pg option.
2. Run a.out
, which produces a gmon.out
executable file, a more sophisticated profiling tool than mon.out
.
3. Type gprof a.out
. The program prints a profile.
–pic
,
-Kpic and –PIC
,
-KPIC
The -pic and -PIC options cause the compiler to generate positionindependent code (PIC). One of these options should be used for objects which are then put into shared libraries. With PIC, each reference to a global datum is generated as a dereference of a pointer in the global offset table. Each function call is generated in pc -relative addressing mode through a procedure linkage table.
The size of the global offset table is limited to 8Kbytes with -pic . The -PIC option expands the global offset table to handle 32-bit addresses for those rare cases where there are too many data objects for -pic .
For more information on PIC , see the section on shared libraries in the Solaris documentation.
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–Qoption
The –Qoption passes an option to the program. The option value must be appropriate to that program and can begin with a plus or minus sign. The program value can be either as (1) (Solaris 1.x only), fbe (1) (Solaris 2.x only), cpp (1), cppas , inline (1), iropt , ld (1), pc0 , or pc3 . For example, the following command passes the option -R to cpp and allows recursive macros: hostname% pc -Qoption cpp -R myprog.p
–Qpath pathname
The –Qpath option inserts a path name into the compilation search path, hence providing an alternate path to search for each compiler component. You can select this option, for instance, to use a different linker or assembler. In the following command, pc searches /home/pascal/sparc for the compiler components and uses them if it finds them; if pc does not find the specified components, it uses the default components: hostname% pc -Qpath /home/pascal/sparc testp.p
–Qproduce
The –Qproduce option instructs pc to produce source code of the type
sourcetype, which can be one of the following:
.o
.pi
.s
Object file from as (1)
Preprocessed Pascal source from cpp (1)
Assembler source. This option is the same as the -S option.
For example, the following command produces the file, hello.s
: hostname% pc -Qproduce .s hello.p
-qp
The -qp option is the same as -p option.
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-R
(Solaris 1.x only) The –R option instructs pc to call the assembler, as (1). This option merges the data segment of the resulting program with the text segment. See also -xMerge (Solaris 2.x only).
-R path [ : dir ]
(Solaris 2.x only) The -R path [: dir ] option passes a colon-separated list of directories that specify the library search path used by the runtime linker. If present and not null, it is recorded in the output object file and passed to the runtime linker.
If both LD_RUN_PATH and the -R option are specified, the -R option takes precedence.
-Rw
The -Rw option checks and issues warnings on record fields which are used, but not set.
By default, the Pascal compiler generates warnings of this kind for whole variables, but not for fields.
This option works only for local record variables that are defined in procedures or functions, not for global variables, that is, variables that are in the main program or in a separately compiled module. This is because global variables may appear to be initialized not in the main program itself, but in some procedure or function that is compiled separately, which is subsequently linked to the executable program.
This option is suppressed when the -Z option is on. See “–Z” on page 66. In this case, all local variables and their components are initialized by zero values.
When this option is on, the compiler performs a full analysis (as far as possible at compile time) of how record fields are assigned and used. Warnings contain full access constructs for fields which are used, but not set, for example,
V.F1.F2^.F3
.
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The compiler issues warnings at the end of the procedure where the record variables are defined, that is, when some of the fields are definitely not set.
However, no warnings are issued if fields are used in the source before they are initialized, as the control flow may be different.
In some cases, it is not possible to determine at compile time whether the fields have actually been initialized. For example:
•
For the array variable V , whose elements are records, if any assignment of the kind V[i]:= X or V[i].F:= Y occurs, the compiler considers the corresponding fields of V[i] for all values of i to be initialized. If such a field is used, but not set, it is denoted as V[...].F
in the warning message.
• All formal parameters are assumed to be initialized. Consequently, the compiler does not perform any checking for these component fields.
With the -Rw option, the compiler takes into account built-in procedures which initialize their argument variables, for example, reset(f) for the file buffer variable f^ and its components.
rewrite(f) does not initialize f^ . The compiler also examines field handling inside WITH statements.
Use the -Rw option to check the use of “unsafe” variant records, such as the assignment of a variant to a field, or the use of another field from a “parallel” variant. These practices may result in runtime errors which are hard to find.
Note – The -Rw option requires extra compile-time, and is, therefore, recommended for use in debugging only.
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Examples:
The Pascal main program, r.p
(record and array of records) program p; procedure qq; type compl = record re, im: integer end;
arc = array[1..2] of compl; var z: compl;
a: arc; begin writeln(z.im); writeln(a[1].re); end; begin end.
The commands to compile r.p
and the -Rw warnings that are issued hostname% pc -Rw r.p
Fri Jan 27 17:35:50 1995 r.p:
In procedure qq: w 18280 field z.im is used but never set w 18280 field a[...].re is used but never set
The Pascal main program, rr.p
(two records) program p; type r = record a,b: integer end; procedure qq; var r1, r2: r; var i: integer; begin
i:=r1.a;
i:=r2.a;
i:=r1.b;
i:=r2.b; end; begin
qq; end.
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The commands to compile rr.p
and the -Rw warnings that are issued hostname% pc -Rw rr.p
Mon Feb 20 14:59:04 1995 pas/rr.p:
In procedure qq: w 18280 field r1.b is used but never set w 18280 field r1.a is used but never set w 18280 field r2.b is used but never set w 18280 field r2.a is used but never set
The Pascal main program, recvar.p
(variant record) program p; procedure qq; type r = record
x,y: integer;
case integer of
0:(a: integer);
1: (b: char); end; var v: r; begin
v.x:= 1;
writeln(v.y); end; begin qq; end.
The commands to compile recvar.p
hostname% pc -Rw recvar.p
Mon Feb 20 15:55:18 1995 recvar.p:
In procedure qq: w 18260 field v.a is neither used nor set w 18260 field v.b is neither used nor set w 18280 field v.y is used but never set hostname% a.out
0
Pascal 4.0 User’s Guide
The Pascal main program, with.p
( with statement) program p; type C = record re, im: integer end;
AC = array[1..2] of C;
RC = record C1, C2: C end;
PRC = ^RC; procedure qq; var
c: C;
ac: AC;
rc: RC;
prc: PRC; begin
ac[1]:= c;
with ac[1] do
begin
re:= 1;
writeln(im);
end;
with prc^.C1 do
begin
writeln(im);
end; end; begin qq; end.
The commands to compile and execute with.p
hostname% pc -Rw with.p
Mon Feb 20 16:28:34 1995 with.p:
In procedure qq: w 18280 variable c is used but never set w 18260 variable rc is neither used nor set w 18280 field prc^.C1.im is used but never set hostname% a.out
0
*** a.out terminated by signal 11: segmentation violation
*** Traceback being written to a.out.trace
Abort (core dumped)
3
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–S
–s[ level ]
The –s option instructs the compiler to accept standard Pascal only. Pascal has two levels of compliance with standard Pascal: Level 0 and Level 1. The only difference between the two is that Level 1 also allows conformant arrays.
Specify the level of compliance as follows:
•
–s0 Accept Level 0 compliance with standard Pascal
•
-s or –s1 Accept Level 1 compliance with standard Pascal
This option causes many features of Pascal that are not found in standard
Pascal to be diagnosed with warning messages. These features include:
• Nonstandard procedures and functions
•
Extensions to the procedure write
• Padding of constant strings with blanks
• Preprocessor directives
In addition, all letters, except character strings and constants, are mapped to lowercase. Thus, the case of keywords and identifiers is ignored.
This option is most useful when a program is to be ported to other machines.
–sb
The –S option compiles the program and outputs the assembly language in the file, sourcefile. s . For example, the following command places the assembly language translation of rmc.p
in the file rmc.s
. No executable file is created.
hostname% pc –S rmc.p
The –sb option produces a database for source browsing.
–sbfast
The –sbfast option performs the same task as -sb , but does not compile.
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-tc
The -tc option instructs the compiler to generate pc3 stab information that allows cross-module type checking.
This option can be used for two purposes:
•
To check for any name conflicts that your program may have with the standard libraries with which it is to be linked, such as libc . The linker allows name conflicts, which may cause erroneous runtime behavior in your program.
For example, the following program has a name conflict with libc :
program p(output);
var time: integer;
begin
writeln(wallclock);
end.
When the program is compiled with the -tc option, pc3 issues a warning that the name time is already defined as a libc routine. Running a.out
causes a core dump. To avoid this problem, change the name of the variable that has the conflict—in this case, time .
•
To check for possible name conflicts in the various modules of your program. These conflicts arise if you define a routine with the same name in several modules, or refer to an external, but undefined, variable. The linker detects these error situations and does not create the executable file.
–temp= dir
The –temp option instructs pc to locate the temporary files that it creates during compilation in the directory named dir. For example, the following command puts the temporary files in the current directory.
hostname% pc -temp=. hello.p
If you do not specify a temporary directory, pc places the temporary files in the /tmp directory.
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–time
The –time option instructs the compiler to report execution performance statistics for the various compilation passes. Here is some sample output; some spaces have been removed so the output would fit on the page.
hostname% pc -time hello.p cpp:time U:0.0s+S:0.1s=0.2s REAL:1.6s 11%. core T:0k D:0k. io IN:4b OUT:3b. pf IN:25p OUt:184p.
pc0:time U:0.0s+S:0.3s=0.4s REAL:3.2s 13%. core T:0k D:4k. io IN:4b OUT:4b. pf IN:70pOUT:131p.
cg: time U:0.0s+S:0.1s=0.2s REAL:2.0s 12%. core T:0k D:1k. io IN:2b OUT:1b. pf IN:39p OUT:163p.
as: time U:0.0s+S:0.2s=0.3s REAL:1.5s 19%. core T:0k D:1k. io IN:3b OUT:10b.pf IN:33pOUT:117p.
pc3:time U:0.1s+S:0.1s=0.3s REAL:0.9s 31%. core T:0k D:1k. io IN:7b OUT:0b. pf IN:20pOUT:109p.
ld:time U:0.8s+S:0.9s=1.8sREAL:10.2s 17%. core T:0k D:21k.io IN:74bOUT:29b.pf IN:89pOUT:184p.
Each line begins with the name of the compiler pass. The rest of the line is divided into four parts: time , core , io , and pf .
• time gives the time used by that pass of the compiler, in this order: a. User time b. System time c. Total CPU time, which is the sum of user and system time d. Real (clock) time e. Percent of real time used by CPU time
• core gives memory usage statistics for the pass, in this order: a. The first item is always 0, and currently has no meaning.
b. The second item is the integral resident set size.
• The io section gives the volume of input and output operations, expressed in blocks.
• The pf section gives the amount of page faults, expressed in pages, in this order: a. Page faults not requiring physical I/O b. Page faults requiring physical I/O
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–U name
The –U option removes any initial definition of the cpp (1) symbol name. See cpp (1) for more information. You cannot use this option with the -xl option.
–V
The –V option prints the version number of each compilation pass.
–V0 and –V1
The –V0 and –V1 options turn on sets of options that insert checks into the object file, as follows:
–V0
–V1
Equivalent to -C , -H , -L , and -s0
Equivalent to –C , –H , –L , and –s1
–v
The –v (verbose) option prints the command line used to call each compilation pass.
–w
By default, the compiler prints warnings about inconsistencies it finds in the input program. The –w option turns off the warnings.
To turn off warnings in a program comment, use this command: hostname% {$w-}
-xa
Same as -a .
-xarch= a
(Solaris 2.x only) The -xarch= a option limits the set of instructions the compiler may use.
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a must be one of: generic , v7 , v8 , v8a , v8plus , v8plusa .
Although this option can be used alone, it is part of the expansion of the xtarget option; its primary use is to override a value supplied by the xtarget option.
This option limits the instructions generated to those of the specified architecture, and allows the specified set of instructions. It does not guarantee an instruction is used; however, under optimization, it is usually used.
If this option is used with optimization, the appropriate choice can provide good performance of the executable on the specified architecture. An inappropriate choice can result in serious degradation of performance.
50 Pascal 4.0 User’s Guide
3 v7, v8, and v8a are all binary compatible.
v8plus and v8plusa are binary compatible with each other and forward, but not backward. For any particular choice, the generated executable can run much more slowly on earlier architectures (to the left in the above list).
Table 3-3 The -xarch Values
Value Meaning generic Get good performance on most SPARCs, and major degradation on none.
v7 v8a
This is the default. This option uses the best instruction set for good performance on most SPARC processors without major performance degradation on any of them. With each new release, this best instruction set will be adjusted, if appropriate.
Limit the instruction set to V7 architecture.
This option uses the best instruction set for good performance on the V7 architecture, but without the quad-precision floating-point instructions.
This is equivalent to using the best instruction set for good performance on the V8 architecture, but without the following instructions:
The quad-precision floating-point instructions
The integer mul and div instructions
The fsmuld instruction
Examples: SPARCstation 1, SPARCstation 2
Limit the instruction set to the V8a version of the V8 architecture.
This option uses the best instruction set for good performance on the V8 architecture, but without:
The quad-precision floating-point instructions
The fsmuld instruction
Example: Any machine based on MicroSPARC I chip architecture
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Table 3-3 The -xarch Values (Continued)
Value v8
Meaning
Limit the instruction set to V8 architecture.
This option uses the best instruction set for good performance on the V8 architecture, but without quad-precision floating-point instructions.
Example: SPARCstation 10 v8plus Limit the instruction set to the V8plus version of the V9 architecture.
By definition, V8plus, or V8+, means the V9 architectue, except:
Without the quad-precision floating point instructions
Limited to the 32-bit subset defined by the V8+ specification
Without the VIS instructions
This option uses the best instruction set for good performance on the V9 architecture. In V8+, a system with the 64-bit registers of V9 runs in 32-bit addressing mode, but the upper 32 bits of the i and l registers must not affect program results.
Example: Any machine based on UltraSPARC chip architecture.
Use of this option also causes the .o
file to be marked as a Sun-specific
V8+ binary; such files will not run on a v7 or v8 machine.
v8plusa Limit the instruction set to the V8plusa version of the V9 architecture.
By defintion, V8plusa means the V8plus arcitecture, plus:
The UltraSPARC-specific instructions
The VIS instructions
This option uses the best instruction set for good performance on the
UltraSPARC™ architecture but limited to the 32-bit subset defined by the
V8+ specification.
Example: Any machine based on UltraSPARC chip architecture.
Use of this option also causes the .o
file to be marked as a Sun-specific
V8+ binary; such files will not run on a v7 or v8 machine.
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-xcache= c
(Solaris 2.x only) The -xcache= c option defines the cache properties for use by the optimizer.
c must be one of the following:
• generic
• s1 / l1 / a1
• s1 / l1 / a1 : s2 / l2 / a2
• s1 / l1 / a1 : s2 / l2 / a2 : s3 / l3 / a3
The si / li / ai are defined as follows: si li ai
The size of the data cache at level i, in kilobytes
The line size of the data cache at level i, in bytes
The associativity of the data cache at level i
Value generic
Although this option can be used alone, it is part of the expansion of the target option; its primary use is to override a value supplied by the target option.
This option specifies the cache properties that the optimizer can use. It does not guarantee that any particular cache property is used.
Table 3-4 The -xcache Values
Meaning
Define the cache properties for good performance on most SPARCs.
This is the default value which directs the compiler to use cache properties for good performance on most SPARC processors, without major performance degradation on any of them.
With each new release, these best timing properties will be adjusted, if appropriate.
s1 / l1 / a1 s1 / l1 / a1 : s2 / l2 / a2
Define level 1 cache properties.
Define levels 1 and 2 cache properties.
s1 / l1 / a1 : s2 / l2 / a2 : s3 / l3 / a3 Define levels 1, 2, and 3 cache properties
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Example: -xcache=16/32/4:1024/32/1 specifies the following:
Level 1 cache has:
16K bytes
32 bytes line size
4-way associativity
Level 2 cache has:
1024K bytes
32 bytes line size
Direct mapping associativity
-xchip= c
(Solaris 2.x only) The -xchip= c option specifies the target processor for use by the optimizer.
c must be one of: generic , old , super , super2 , micro , micro2 , hyper , hyper2 , powerup , ultra
Although this option can be used alone, it is part of the expansion of the target option; its primary use is to provide a value supplied by the -target option.
This option specifies timing properties by specifying the target processor.
Some effects are:
•
The ordering of instructions, that is, scheduling
• The way the compiler uses branches
• The instructions to use in cases where semantically equivalent alternatives are available
Table 3-5 The -xchip Values
Value Meaning generic Use timing properties for good performance on most SPARCs.
old super
This is the default value that directs the compiler to use the best timing properties for good performance on most SPARC processors, without major performance degradation on any of them.
Use timing properties of pre-SuperSPARC™ processors.
Use timing properties of the SuperSPARC chip.
super2 Use timing properties of the SuperSPARC II chip.
micro Use timing properties of the MicroSPARC™ chip.
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Table 3-5 The -xchip Values (Continued)
Value Meaning micro2 Use timing properties of the MicroSPARC II chip.
hyper ultra
Use timing properties of the HyperSPARC™ chip.
hyper2 Use timing properties of the HyperSPARC II chip.
powerup Use timing properties of the Weitek
®
PowerUp™ chip.
Use timing properties of the UltraSPARC chip.
-xcg89
Same as -cg89 .
-xcg92
Same as -cg92 .
–xF
(Solaris 2.x only) The –xF option enables performance analysis of the executable file using the SPARCworks Performance Analyzer and Debugger. This option also causes the assembler to generate some debugging information in the object file, necessary for data collection. The compiler generates code that can be reordered at the function level. It takes each function in the file and places it into a separate section. For example, functions fcn1() and fcn2() are placed in the sections .text%fcn1 and .text%fcn2 . You can control the order of functions in the final executable by using the –xF and the loader
–Mmapfile options.
In the map file, if you include the flag O in the string of segment flags, then the static linker ld attempts to place sections in the order they appear in the map file. See the Solaris documentation for details about this option, the segment flags, and the map file.
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-xildoff
(Solaris 2.x only) Turns off the incremental linker and forces the use of ld . This option is the default if you do not use the -g option, or you do not use the -G option, or any source files are present on the command line. Override this default by using the -xildon option.
xildon
(Solaris 2.x only) Turns on the incremental linker and forces the use of ild in incremental mode. This option is the default if you use the -g option, and you do not use the -G option, and there are no source files present on the command line. Override this default by using the -xildoff option.
–xl
The –xl option implements a set of features that provide broad compatibility with Apollo Pascal. We recommend using –xl only when porting Pascal systems from Apollo platforms to SPARC system platforms. See the Pascal 4.0
Reference Manual for details of the features controlled by -xl .
When you use -xl , the compiler invokes the cppas preprocessor in place of cpp (1). See Appendix A, “Pascal Preprocessor,” for information on cppas .
Modules compiled with –xl are not compatible with modules compiled without –xl . You should not link these two types of modules together.
-xlibmieee
Same as -libmieee .
-xlibmil
Same as -libmil .
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-xlibmopt
Uses a math routine library optimized for performance. The results may be slightly different than those produced by the normal math library. This option is implied by the -fast option.
–xlicinfo
The -xlicinfo option returns information about the licensing system. In particular, it returns the name of the license server and the IDs of users who have licenses checked out. When you give this option, the compiler is not invoked and a license is not checked out.
–xMerge
(Solaris 2.x only) The –xMerge option instructs pc to call the assembler, as (1), with the –R option. This option merges the data segment of the resulting program with the text segment. See also -R (Solaris 1.x only).
-xnolib
Same as -nolib .
-xnolibmopt
Resets -fast , and does not use the math routine library.
Use this option after the -fast option on the command-line, as in: pc -fast -xnolibmopt ....
-x05
Optimizes the object code.
(Solaris 2.x) This option can be combined with –g , but not with –xa .
When -O is used with the -g option, a limited amount of debugging is available.
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Generates the highest level of optimization. Uses optimization algorithms that take more compilation time or that do not have as high a certainty of improving execution time. Optimization at this level is more likely to improve performance if it is done with profile feedback. See -xprofile=p .
If the optimizer runs out of memory, it tries to recover by retrying the current procedure at a lower level of optimization and resumes subsequent procedures at the original level specified in the command-line option.
-xpg
Same as -p and -pg
-xprofile= p
(Solaris 2.x only) The -xprofile= p option collects data for a profile or use a profile to optimize.
p must be collect , use[ :name] , or tcov .
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This option causes execution frequency data to be collected and saved during execution, then the data can be used in subsequent runs to improve performance.
Table 3-6 The -xprofile Values
Value Meaning collect Collect and save execution frequency for later use by the optimizer.
use tcov
The compiler inserts code to measure the execution frequency at a low level. During execution, the measured frequency data is written into
.prof
files that correspond to each of the source files.
If you run the program several times, the execution frequency data accumulates in the .prof
files; that is, output from prior runs is not lost.
Use execution frequency data saved by the compiler.
Optimize by using the execution frequency data previously generated and saved in the .prof
files by the compiler.
The source files and the compiler options (excepting only this option), must be exactly the same as for the compilation used to create the compiled program that was executed to create the .prof
files.
Correctly collects data for programs that have source code in header files or make use of C++ templates. See -a for information on the old style of profiling, the tcov (1) man page, and the Profiling Tools manual for more details.
Code instrumentation is performed similarly to that of -a , but .d
files are no longer generated. Instead, a single file is generated, whose name is based off of the final executable. For example, if the program is run out of /foo/bar/myprog , then the data file is stored in
/foo/bar/myprog.profile/myprog.tcovd
.
When running tcov , you must pass it the -x option to make it use the new style of data. If not, tcov uses the old .d
files, if any, by default for data, and produces unexpected output.
Unlike -a , the TCOVDIR environment variable has no effect at compiletime. However, its value is used at program runtime.
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-xregs= r
(Solaris 2.x only) The -xregs= r option specifies the usage of registers for the generated code.
r is a comma-separated list that consists of one or more of the following:
[ no% ] appl , [ no% ] float .
Example: -xregs=appl,no%float
Table 3-7 The -xregs Values
Value appl
Meaning
Allow using the registers g2 , g3 , and g4 .
In the SPARC ABI, these registers are described as application registers.
Using these registers can increase performance because fewer load and store instructions are needed. However, such use can conflict with some old library programs written in assembly code.
no%appl Do not use the appl registers.
float Allow using the floating-point registers as specified in the SPARC ABI.
You can use these registers even if the program contains no floatingpoint code.
no%float Do not use the floating-point registers.
With this option, a source program cannot contain any floating-point code.
The default is -xregs=appl,float .
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–xs
(Solaris 2.x only) The -xs option disables Auto-Read for dbx in case you cannot keep the .o
files around. This option passes the -s option to the assembler and the linker.
•
No Auto-Read —This is the older way of loading symbol tables.
• The compiler instructs the linker to place all symbol tables for dbx in the executable file.
• The linker links more slowly and dbx initializes more slowly.
• If you move the executables to another directory, then to use dbx you must move the source files, but you need not move the object ( .o
) files.
•
Auto-Read —This is the newer (and default) way of loading symbol tables.
• The compiler distributes this information in the .o
files so that dbx loads the symbol table information only if and when it is needed.
• The linker links faster and dbx initializes faster.
• If you move the executables to another directory, then to use dbx , you must move both the source files and the object ( .o
) files.
-xsafe=mem
(Solaris 2.x only) The -xsafe=mem option allows the compiler to assume no memory-based traps occur.
This option grants permission to use the speculative load instruction on V9 machines.
-xsb
Same as -sb .
-xsbfast
Same as -sbfast .
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-xspace
(Solaris 2.x only) The -xspace option does no optimizations that increase the code size.
Example: Do not unroll loops.
-xtarget= t
(Solaris 2.x only) The -xtarget= t option specifies the target system for the instruction set and optimization.
t must be one of: native , generic , system-name.
The -xtarget option permits a quick and easy specification of the -xarch ,
-xchip , and -xcache combinations that occur on real systems. The only meaning of -xtarget is in its expansion.
Table 3-8 The -xtarget Values
Value native
Meaning
Get the best performance on the host system.
generic
The compiler generates code for the best performance on the host system. It determines the available architecture, chip, and cache properties of the machine on which the compiler is running.
Get the best performance for generic architecture, chip, and cache.
The compiler expands -xtarget=generic to:
-xarch=generic -xchip=generic -xcache=generic system-name
This is the default value.
Get the best performance for the specified system.
You select a system name from Table 3-9 that lists the mnemonic encodings of the actual system names and numbers.
The performance of some programs may benefit by providing the compiler with an accurate description of the target computer hardware. When program performance is critical, the proper specification of the target hardware could be
Pascal 4.0 User’s Guide
3 very important. This is especially true when running on the newer SPARC processors. However, for most programs and older SPARC processors, the performance gain is negligible and a generic specification is sufficient.
Each specific value for -xtarget expands into a specific set of values for the xarch , -xchip , and -xcache options. See Table 3-9 for the values. For example:
-xtarget=sun4/15 is equivalent to:
-xarch=v8a -xchip=micro -xcache=2/16/1
Table 3-9 -xtarget Expansions
-xtarget sun4/15 sun4/20 sun4/25 sun4/30 sun4/40 sun4/50 sun4/60 sun4/65 sun4/75 sun4/110 sun4/150 sun4/260 sun4/280 sun4/330 sun4/370 sun4/390 sun4/470 sun4/490 sun4/630 v7 v7 v7 v7 v7 v7 v7 v7 v7 v7 v7 v7 v7
-xarch v8a v7 v7 v8a v7 v7 old old old old old old old old old old old old old
-xchip micro old old micro old old
-xcache
2/16/1
64/16/1
64/32/1
2/16/1
64/16/1
64/32/1
64/16/1
64/16/1
64/32/1
2/16/1
2/16/1
128/16/1
128/16/1
128/16/1
128/16/1
128/16/1
128/32/1
128/32/1
64/32/1
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64 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v7 v8a v8a v8a v7 v7 v7 v7 v8a v7 v8a v8a
-xarch v7 v7 v7 v7 v7 ss2p ss4 ss5 ssvyger ss10 ss10/hs11 ss10/hs12 ss10/hs14 ss10/20 ss10/hs21 ss10/hs22 ss10/30 ss10/40 ss10/41 ss10/50
-xtarget sun4/670 sun4/690 sselc ssipc ssipx sslc sslt sslx sslx2 ssslc ss1 ss1plus ss2
Pascal 4.0 User’s Guide super hyper hyper super super super super powerup micro2 micro2 micro2 super hyper hyper hyper
-xchip old old old old old old old old old micro old micro micro2
-xcache
64/32/1
64/32/1
64/32/1
64/16/1
64/32/1
2/16/1
64/32/1
2/16/1
8/64/1
64/16/1
64/16/1
64/16/1
64/32/1
64/31/1
8/64/1
8/64/1
8/64/1
16/32/4
256/64/1
256/64/1
256/64/1
16/32/4
256/64/1
256/64/1
16/32/4
16/32/4
16/32/4:1024/32/1
16/32/4
v8 v8 v7 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8 v8
-xarch v8 v8 v8 v8 v8 ss20/hs22 ss20/51 ss20/61 ss20/71 ss20/91 ss20/502 ss10/512 ss20/514 ss20/612 ss20/712 ss20/912 ss600/41 ss600/51 ss600/61 ss600/120
-xtarget ss10/51 ss10/61 ss10/71 ss10/402 ss10/412 ss10/512 ss10/514 ss10/612 ss10/712 ss20/hs11 ss20/hs12 ss20/hs14 ss20/hs21
The Pascal Compiler super super super super super super old hyper super super super2 super2 super super super
-xchip super super super2 super super super super super super2 hyper hyper hyper hyper
-xcache
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
256/64/1
256/64/1
256/64/1
256/64/1
256/64/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
64/32/1
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-xtarget ss600/140 ss600/412 ss600/ ss600/ ss600/ ss1000 sc2000 cs6400 solb5 solb6 ultra ultra1/140 ultra1/170 ultra1/1170 ultra1/2170 ultra1/2200 v8 v8 v8 v8 v8 v8 v8 v7 v8 v8 v8
-xarch v7 v8 v8 v8 v8 super super super old super ultra ultra ultra
-xchip old super super super super ultra ultra ultra
-xcache
64/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/32/1
16/32/4:1024/64/1
16/32/4:2048/64/1
128/32/1
16/32/4:1024/32/1
16/32/1:512/64/1
16/32/1:512/64/1
16/32/1:512/64/1
16/32/1:512/64/1
16/32/1:512/64/1
16/32/1:1024/64/1
–Z
The –Z option instructs pc to insert code that initializes all local variables to zero. Standard Pascal does not allow initialization of variables.
-ztext
(Solaris 2.x only) The -ztext option forces a fatal error if relocations remain against non-writable, allocatable sections.
Pascal 4.0 User’s Guide
Units
Program Construction and
Management
4
This chapter is an introduction to the methods generally used to construct and manage programs using Pascal. It describes units and libraries in two separate sections:
Units
Libraries page 67 page 74
For many reasons, it is often inconvenient to store a program in a single file, as in the case of a very large program.
You can break up a program in several ways. Perhaps the simplest way is to use an include file. An include file is a separate file that is copied in by the compiler when it encounters an include compiler directive. For example, in the following program: program include (output);
#include "includefile" the line #include "includefile" is a compiler directive to cpp (1), the
Pascal compiler’s preprocessor. The directive instructs cpp (1) to find the file includefile and copy it into the stream before continuing.
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The actual includefile looks like this: begin writeln ('Hello, world.') end.
In this example, the include file contains the entire program. In reality, an include file probably contains a set of variable or procedure declarations.
include files are often used when a set of declarations needs to be shared among a number of programs.
However, suppose your program is very large and takes a long time to compile. Using include files may make editing more convenient, but when you make a change in one part of your program, you still must recompile the entire program. As another example, suppose you want to be able to share compiled code with other people, but for reasons of security or convenience, do not want to share the source code.
Both of these problems are solved by separately compiled units, generally called units. A unit is a part of a program stored in its own file and linked with the rest of the program after compilation.
Using Program Units and Module Units
There are two kinds of units:
•
Program unit —This unit looks like any program. It begins with a program header and contains the main program.
Here is an example: program program_unit (output); procedure say_hello; extern; begin say_hello end.
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The body of the procedure say_hello is not defined in this program unit, but the program unit does contain a declaration of the interface to the procedure. The keyword extern declares that say_hello is declared in a module unit.
1
•
Module unit —This unit can begin with an optional module header, followed by a set of compilable declarations and definitions. Modules that call externally defined routines must have declarations for those routines.
Here is an example: module module_unit; procedure say_hello; begin writeln ('Hello, world.') end;
Every program must have one and only one program unit; a program can have any number of module units. Any unit can call procedures declared in any other unit; each unit must have external declarations for every procedure it uses that is not defined in that unit.
A module unit can also be used as a library, that is, as a collection of useful routines that is shared among a number of programs.
Compiling with Units
Consider the units given in the previous section, “Using Program Units and
Module Units.” You can compile and link these units on a single line by executing the following command, which then produces the executable, a.out
.
hostname% pc program_unit.p module_unit.p
1. A statement that shows the interface of a routine is called a declaration, because it declares the name and parameters of the routine. The set of statements that shows the entire routine, including the body, is called the definition of the routine. There can be only one definition for a given routine, but every routine must be declared in every module or program unit that uses it.
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You can also separate the compilation and linking or loading steps, as follows: hostname% pc program_unit.p -c hostname% pc module_unit.p -c hostname% pc program_unit.o module_unit.o
In this case, you call pc on each unit with the “compile only” option ( -c ), which produces an object file with the extension .o
. When you use this option, the compiler driver does not call the linker, ld . You then call pc a second time, giving the names of the object files, and pc calls pc3 to check for name and type conflicts before calling the linker.
Calling the linker or loader ld (1) directly does not have the same effect as calling pc ; when you call ld (1) directly, the files are linked and loaded, but they are not checked for conflicts.
Using Units and Header Files
A complex program may have many routines defined in modules. Each routine must have a declaration (for example, procedure proc; extern; ) in each file that calls the routine. The easiest way to be sure that you have a correct and consistent set of declarations is to create a header file.
A header file is a file that contains a set of declarations, nothing else. You use a header file by using an include directive to include the header file in the compilation.
For example, here is a modified version of the program, program_unit , that uses a header file: program program_unit2 (output); include "header.h" begin say_hello end.
In this case, the content of header.h
is very simple: procedure say_hello; extern;
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4
In a real program, header.h
would probably contain many declarations and would be included in several modules. Aside from routine declarations, header files often contain constant, type, and variable declarations.
Sharing Variables Between Units
Variables that are global across a unit (that is, not declared locally in a routine) can be public or private . A public variable can be shared by any unit that is linked to the unit that declares the variable. A private variable cannot be shared.
You can use the public and private reserved words to declare that a var section declares public or private variables. For example: program program_unit3 (output); public var x : integer; private var y : integer;
When you do not use public or private , variables are public by default.
However, when you compile with the -xl option, variables are private by default.
To share a public variable, simply declare it in each unit where you want to share it. As long as the variable is public , each reference to that variable accesses the same data.
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Here is a program unit that declares a variable: program program_unit3 (output); var x : integer; procedure say_hello; external; begin for x := 1 to 5 do say_hello end.
Here is a module unit that declares a variable with the same name: module module_unit3; var x : integer; procedure say_hello; begin writeln ('Hello, world for the', x, ' time.') end;
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By default, both definitions of variable x are public . Thus, when you compile and link the program and module units, references to x refer to the same variable, as follows: hostname% pc program_unit3.p module_unit3.p program_unit.p: module_unit.p:
Linking: hostname% a.out
Hello, world for the 1 time.
Hello, world for the 2 time.
Hello, world for the 3 time.
Hello, world for the 4 time.
Hello, world for the 5 time.
If you compile the program giving the -xl option, the variables are private by default, as follows: hostname% pc -xl program_unit.p module_unit.p program_unit.p: module_unit.p:
Linking: hostname% a.out
Hello, world for the 0 time.
Hello, world for the 0 time.
Hello, world for the 0 time.
Hello, world for the 0 time.
Hello, world for the 0 time.
You can get the same effect by explicitly declaring the variable in a private var section. Similarly, when you use -xl , you can create public variables by declaring them in a public var section.
As with routine declarations, it is often a good idea to declare public variables in an include file. Doing so makes it easier to keep your declarations consistent.
There are other methods for making variables visible to different units. See
Chapter 5, “Separate Compilation,” for more information.
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Libraries
You can use a module unit as a library of useful functions. The simplest way to do so is to create a source file containing the definitions of your library routines and then compile it using the -c option. You can then link the resulting .o
file to any number of files. For convenience, you probably should create a header file containing the routine declarations for the library.
A simple library as described above has two problems:
• When a library grows in size, it may become inconvenient to store its source in a single file, both for ease of editing and so you can avoid recompiling a large file when you change only part of it.
On the other hand, it would be inconvenient to have to name many library modules on the command-line when you link your program. Thus, it would be helpful to be able to combine a number of library modules.
•
Several programs that you run at the same time may share the same library.
Under the scheme described above, each program has its own copy of the library. It saves space and even I/O time if several programs share library code.
Both problems have solutions. First, you can combine or archive modules together. Secondly, you can create a shared library.
See the Solaris documentation on the linker and libraries for information on creating archived and shared libraries.
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Separate Compilation
5
This chapter describes how to compile Pascal programs in separate units.
Chapter 4, “Program Construction and Management,” gives an introduction to the concepts in this chapter. Following are the sections:
Working with Units
Sharing Variables and Routines Across Multiple Units
Sharing Declarations in Multiple Units page 75 page 76 page 87
In separate compilation, a program is divided into several units that can be separately compiled into object ( .o
) files. The object files are then linked using pc , which invokes pc3 to check for the consistent use of global names and declarations across the different units, and then invokes ld (1) to link and load the units. You can also give pc the names of all the units at once, in which case pc compiles all the units, checks for consistency, and links the units in one step.
Separate compilation is different from independent compilation. In independent compilation, you invoke ld directly, so there is no consistency checking. Independent compilation is not addressed in this guide.
Working with Units
Pascal provides two types of source files or units: the program unit and the module unit.
75
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Using Program Units
The program unit is the source program with the program header. It has the following syntax:
< program unit > ::= < program heading > < declaration list > < program body >
Each program you write can have only one program unit. The program body is the first code that Pascal executes.
Using Module Units
A module unit is a source program that does not have a program header. It has the following syntax:
< module unit > ::= [ < module heading > ] < declaration list >
The module heading contains the reserved word module followed by an identifier:
< module heading > ::= [ 'module' < identifier > ';' ]
For example: module sum;
This is a legal module heading. The module heading is optional.
Sharing Variables and Routines Across Multiple Units
Pascal supports three methods of sharing variables and routines between units:
• include files
•
Multiple variable declarations
• extern/define variable declarations
These methods are not mutually exclusive; for example, you can declare a variable as either extern or define in an include file.
The following sections describe these methods.
76 Pascal 4.0 User’s Guide
The program unit, shrvar_prog.p
5
Compiling without the
-xl
Option
There are three ways of sharing variables and routines across units when you compile your program without the –xl option.
Sharing Public Variables
If you declare a variable in two or more separate units and the variable is public in both places, that variable is shared between units. Variables are public by default, unless you compile with the -xl option, in which case variables are private by default. In this example, the variable global is public by default, and thus shared between the program and the module.
program shrvar_prog; var
global: integer; procedure proc; external; begin { program body }
global := 1;
writeln('From MAIN, before PROC: ', global);
proc;
writeln('From MAIN, after PROC: ', global) end. { shrvar_prog }
The module unit, shrvar_mod.p
.
The assignment of a new value to global and max_array in the procedure proc in shrvar_prog.p
is repeated in shrvar_mod.p
.
module shrvar_mod; var
global: integer; procedure proc; begin writeln('From PROC: ',global); global := global + 1 end; { proc }
Separate Compilation 77
5
The commands to compile and execute shrvar_prog.p
and shrvar_mod.p
hostname% pc shrvar_prog.p shrvar_mod.p shrvar_prog.p: shrvar_mod.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 1
From MAIN, after PROC : 2
Using
extern
Option to Share Routines
If a program or module calls a procedure not defined in that unit, you must declare it with either the extern or external routine option. For instance, in the previous example, the procedure proc is defined in shrvar_mod.p
, but used in shrvar_prog.p
. Thus, it is declared as external in shrvar_prog.p
. Also, proc must also be defined as public in shrvar_mod.p
, which is the default.
Using
include
Files to Share Variables and Routines
The include file contains the declarations for the program. Placing all program declarations in a single file makes your program more consistent and easier to maintain.
To use this feature, place the number sign character ( # ) in the first position of a line immediately followed by the word include , and then a file name enclosed in angle brackets ( < and > ) or double quotation marks ( " ). The different enclosures ( <> and "" ) affect the search order for files. The syntax for the #include directive is determined by cpp (1).
When the compiler encounters the #include in the input, it inserts the lines from the included file into the input stream.
78 Pascal 4.0 User’s Guide
5
The program unit, inc_prog.p
, which includes the file include.h
program inc_prog;
#include "include.h" begin { program body}
global := 1;
writeln('From MAIN, before PROC: ', global);
proc;
writeln('From MAIN, after PROC: ', global) end. { inc_prog }
The module unit, inc_mod.p
, which also includes the file include.h
module inc_mod;
#include "include.h" procedure proc; begin
writeln('From PROC : ', global);
global := global + 1 end; { proc }
The include file, include.h
var
global : integer; procedure proc; extern;
The commands to compile and execute inc_prog.p
and inc_mod.p
hostname% pc inc_prog.p inc_mod.p inc_prog.p: inc_mod.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 1
From MAIN, after PROC: 2
Separate Compilation 79
5
Using the
-xl
Option
When you use the – xl option, variables and top-level procedures and functions declared in the program unit default to private . Look at the difference when you compile and execute shrvar_prog.p
and shrvar_mod.p
with – xl . See the source code in “Sharing Public Variables” on page 77.
The commands to compile and execute shrvar_prog.p
and shrvar_mod.p
with the –xl option hostname% pc -xl shrvar_prog.p shrvar_mod.p shrvar_prog.p: shrvar_mod.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 0
From MAIN, after PROC: 1
Without – xl , the variable global in shrvar_mod.p
is treated as public ; here, global is treated as private . Thus, the assignment: global := global + 1; is not reflected in shrvar_prog.p
; instead, each file uses its own private copy of global .
The following sections describe five ways of sharing variables and routines across units when you compile your program with – xl .
Using
public var
Declarations
The following examples uses the public attribute in the var declaration to make global public when you compile your program with –xl .
80 Pascal 4.0 User’s Guide
5
The program unit, pubvar_prog.p
, which declares global as public program pubvar_prog; public var
global: integer; procedure proc;
external; begin
global := 1;
writeln('From MAIN, before PROC: ', global);
proc;
writeln('From MAIN, after PROC: ', global) end. { pubvar_prog }
The module unit, pubvar_mod.p
, which also declares global as public module pubvar_mod; public var
global : integer; procedure proc; begin
writeln('From PROC :',global);
global := global + 1; end; { proc }
The commands to compile and execute pubvar_prog.p
and pubvar_mod.p
hostname% pc -xl pubvar_prog.p pubvar_mod.p pubvar_prog.p: pubvar_mod.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 1
From MAIN, after PROC: 2
Separate Compilation 81
5
The program unit, defvar_prog.p
Using the
define
Variable Attribute
This example makes global public using the define attribute of the variable declaration.
program defvar_prog; var
global: extern integer; procedure proc;
external; begin
global := 1;
writeln('From MAIN, before PROC: ', global);
proc;
writeln('From MAIN, after PROC: ', global); end. { defvar_prog }
The module unit, defvar_mod.p
, which makes global public using the define attribute module defvar_mod; var
global : define integer; procedure proc; begin
writeln('From PROC : ',global);
global := global + 1; end; { proc }
82 Pascal 4.0 User’s Guide
5
The commands to compile and execute defvar_prog.p
and defvar_mod.p
hostname% pc -xl defvar_prog.p defvar_mod.p defvar_prog.p: defvar_mod.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 1
From MAIN, after PROC : 2
Using the
define
Declaration
This example defines global in the module defvar_mod2 using the define declaration. The advantage of using the define declaration over the define variable attribute is that the define declaration can be easily converted to use include files.
The program unit, defvar_prog.p
program defvar_prog; var
global: extern integer; procedure proc;
external; begin
global := 1;
writeln('From MAIN, before PROC: ', global);
proc;
writeln('From MAIN, after PROC: ', global) end. { defvar_prog }
Separate Compilation 83
5
The module unit, defvar_mod2.p
, which defines global in a define declaration module defvar_mod2; var
global : extern integer; define
global; procedure proc; begin
writeln('From PROC : ',global);
global := global + 1; end; { proc }
The commands to compile and execute defvar_prog.p
and defvar_mod2.p
hostname% pc -xl defvar_prog.p defvar_mod2.p defvar_prog.p: defvar_mod2.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 1
From MAIN, after PROC : 2
Using
include
Files
In the following example, the extern declaration for the variable global is in the include file, inc_prog2.p
, and is therefore included in both files. The define declaration in file inc_mod2.p
cancels the extern definition.
84 Pascal 4.0 User’s Guide
The program unit , inc_prog2.p
program inc_prog2;
%include "include2.h"; procedure proc; extern; begin
global := 1;
writeln('From MAIN, before PROC: ',global);
proc;
writeln('From MAIN, after PROC: ',global); end. { proc }
The module unit , inc_mod2.p
module inc_mod2; define
global;
%include "include2.h"; procedure proc; begin
writeln('From PROC : ',global);
global := global + 1; end; { proc }
The include file, include2.h
var
global : extern integer;
5
Separate Compilation 85
5
The commands to compile and execute inc_prog2.p
and inc_mod2.p
hostname% pc -xl inc_prog2.p inc_mod2.p inc_prog2.p: inc_mod2.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 1
From MAIN, after PROC : 2
Using
extern
In the previous example, the extern definition for variables is put into an include file and then shared. You can do the same for the extern procedure definition. In doing so, you must also declare the variable with a define declaration in the module that defines the procedure. This declaration nullifies the effect of the extern declaration.
The program unit, ext_prog.p
program ext_prog;
%include "extern.h"; begin
global := 1;
writeln('From MAIN, before PROC: ',global);
proc;
writeln('From MAIN, after PROC: ',global); end. { ext_prog }
86 Pascal 4.0 User’s Guide
5
The module unit, ext_mod.p
module ext_mod; define
global, proc;
%include "extern.h"; procedure proc; begin
writeln('From PROC : ',global);
global := global + 1; end; { proc }
The include file, extern.h
var
global : extern integer; procedure proc; extern;
The commands to compile and execute ext_prog.p
and ext_mod.p
hostname% pc -xl ext_prog.p ext_mod.p ext_prog.p: ext_mod.p:
Linking: hostname% a.out
From MAIN, before PROC: 1
From PROC : 1
From MAIN, after PROC: 2
Sharing Declarations in Multiple Units
Using extern and external directives for procedure and function declarations, you can optionally specify the source language of a separately compiled procedure or function. For example, extern fortran directs the compiler to generate calling sequences compatible with the FORTRAN compiler from SunSoft . Then, external c directs the compiler to generate calling sequences compatible with SunSoft C compiler.
Separate Compilation 87
5
For routines declared extern fortran or external fortran , the changes in the calling sequence are as follows:
• For value parameters, the compiler creates a copy of the actual argument value in the caller’s environment and passes a pointer to the temporary variable on the stack. Thus, you need not create (otherwise useless) temporary variables.
•
The compiler appends an underscore to the name of the external procedure to conform to a naming convention of the f77 (1) compiler. Pascal procedure names called from underscore ( _ ).
FORTRAN must supply their own trailing
• Multidimensional Pascal arrays are not compatible with FORTRAN arrays.
Because FORTRAN uses column-major ordering, a multidimensional
Pascal array passed to FORTRAN appears transposed.
For routines declared extern c or external c , a warning is generated if you attempt to pass a nested function.
When you compile your program with the –xl option, you can also use nonpascal to declare non-Pascal routines when porting written in DOMAIN Pascal, FORTRAN , and C.
DOMAIN programs
88 Pascal 4.0 User’s Guide
The C–Pascal Interface
6
This chapter describes how to mix C and Pascal modules in the same program.
It contains the following sections:
Compilation of Mixed-Language Programs
Compatibility of Types for C and Pascal
General Parameter Passing in C and Pascal
Procedure Calls: C–Pascal
Procedure Calls: Pascal–C
Procedures and Functions as Parameters
Global Variables in C and Pascal
File-Passing Between Pascal and C page 89 page 90 page 93 page 93 page 117 page 132 page 133 page 134
The examples in this chapter assume that you are using the ANSI C compiler.
To invoke ANSI C:
• On the Solaris 1.x environment, use the acc command
• On the Solaris 2.x environment, use the cc command
Compilation of Mixed-Language Programs
You must use the compiler option –lpc when you compile a C main routine that calls Pascal.
–lpc includes the Pascal object library libpc . For example: hostname% pc -c -calign my_pascal.p hostname% cc my_pascal.o my_c.c -lpc
89
6
The -c option produces an unlinked object file. The -calign option causes pc to use C-like data formats for aggregate objects.
When you compile a Pascal main routine that calls C, you don’t have to use any special options, but the -calign option is again useful. The C object library, libc , is automatically brought in for every Pascal compilation.
For example: hostname% cc -c my_c.c hostname% pc -calign my_c.o my_pascal.p
Compatibility of Types for C and Pascal
Table 6-1 and Table 6-2 list the default sizes and alignments of compatible types for C and Pascal.
Table 6-1 C and Pascal Size and Alignment of Compatible Types
Pascal Type double longreal real single shortreal integer16 integer32 integer
C Type double double double float float short int int int
-128..127
char boolean alfa char char a [10 ] char char string char a [80] varying[n] of char struct { int , char [n]} record struct/union
Size (bytes) Alignment (bytes)
8 8
4
4
8
8
8
8
4
4
1
10
1
80
-
-
4
1
2
4
2
4
4
1
1
1
1
1
4
Same as element type
90 Pascal 4.0 User’s Guide
6
Table 6-1 C and Pascal Size and Alignment of Compatible Types (Continued)
Pascal Type array variant record fields in packed record
C Type array struct/union bit field
Size (bytes) Alignment (bytes)
Same as element type
-
-
-
-
Table 6-2 C and Pascal Size and Alignment of Compatible Types with –xl
Pascal Type real integer
C Type float short int
Size (bytes) Alignment (bytes)
4
2
4
2
Precautions with Compatible Types
This section describes the precautions you should take when working with compatible types.
The
shortreal
Type
The Pascal shortreal and C float compatibility works if you pass by reference. See “Value Parameters” on page 112 for examples that show you how to pass by value.
Character Strings
C has several assumptions about strings. All C strings are:
• Passed by reference since C strings are arrays
•
Terminated by a null byte
• Located in static variable storage
You can satisfy these assumptions as follows:
•
Pass by reference by making the strings var , in , out , or in out parameters.
•
Provide the null byte explicitly before passing a string to C. Pascal guarantees the null byte only if the string is a constant. The null byte is not required by the ISO Pascal Standard.
The C–Pascal Interface 91
6
92
Array Indexes
Pascal array indexes can start at any integer; C array indexes always start at zero.
Aggregate Types
Aggregate types include arrays, varying arrays, sets, strings, alphas, records, and variant records.
Pascal aggregate types may require alignment and layout adjustment to match
C unions, structures, and arrays. Pascal aggregate types can be any of the following: arrays, varying arrays, sets, strings, alphas, records, or variant records.
However, you can use the -calign option to eliminate some of these differences. With -calign , the following assumptions are made:
• Pascal records have the same data layout as C structures.
•
Arrays have the same data layout in both languages. However, if you use the -xl option in addition to -calign , boolean arrays with an odd number of elements are different.
• Pascal variants are the same as C unions.
Incompatibilities
This section describes the incompatibilities between C and Pascal types.
Enumerated Types
C enumerated types are incompatible with Pascal enumerated types. Pascal enumerated types are represented internally by sequences of integral values starting with 0. Storage is allocated for a variable of an enumerated type as if the type was a subrange of integer. For example, an enumerated type of fewer than 128 elements is treated as 0..127, which, according to the rules above, is equivalent to a char in C.
C enumerated types are allocated a full word and can take on arbitrary integer values.
Pascal 4.0 User’s Guide
6
Pascal Set Types
In Pascal, a set type is implemented as a bit vector, which is similar to a C short-word array, where each short-word contains two bytes. Thus, sets are bit-vectors, and they are allocated in multiples of 16 bits. To find out the size of a set, enter the following code: ceiling( ord( highest_element ) / 16 )
Direct access to individual elements of a set is highly machine-dependent and should be avoided.
General Parameter Passing in C and Pascal
A few general rules apply to parameter passing:
•
C passes all arrays by reference since C strings are arrays.
• C passes all structures by value.
• In C, if you want to pass anything else by reference, then you must explicitly prepend the reference ampersand ( & ), or pass an explicit pointer.
• Pascal passes all parameters by value unless you explicitly state that they are var , in out , or out parameters, in which case they are passed by reference.
Procedure Calls: C–Pascal
Here are examples of how a C main program calls a Pascal procedure:
The Pascal procedure, Samp , in the file Samp.p
. Note the procedure definition.
procedure Samp(var i: integer; var r: real); begin
i := 9;
r := 9.9
end; { Samp }
The C–Pascal Interface 93
6
The C main program,
SampMain.c
. Note the procedure definition and call.
#include <stdio.h> extern void Samp(int *, double *); int main (void)
{
int i ;
double d ;
Samp(&i, &d) ;
printf ("%d %3.1f \n", i, d) ;
}
The commands to compile and execute Samp.p
and
SampMain.c
hostname% pc -c Samp.p hostname% cc Samp.o SampMain.c hostname% a.out
9 9.9
Variable Parameters
Pascal passes all variable parameters by reference, which C can do, too.
94 Pascal 4.0 User’s Guide
The Pascal procedure,
SimVar.p
The C main program,
SimVarMain.c
Simple Types without
–xl
Without -xl , simple types match, as in the following example: procedure SimVar(
var t, f: boolean;
var c: char;
var si: integer16;
var i: integer;
var sr: shortreal;
var r: real); begin
t := true;
f := false;
c := 'z';
si := 9;
i := 9;
sr := 9.9;
r := 9.9; end; { SimVar }
#include <stdio.h> extern void SimVar(char *, char *, char *, short *,
int *, float *, double *); int main(void)
{
char
short
int
float
double t, f, c; si; i; sr; r;
SimVar(&t, &f, &c, &si, &i, &sr, &r);
printf(" %08o %08o %c %d %d %3.1f %3.1f \n", t, f, c, si, i, sr, r);
}
6
The C–Pascal Interface 95
96
6
The commands to compile and execute SimVar.p
and
SimVarMain.c
hostname% pc -c SimVar.p hostname% cc SimVar.o SimVarMain.c hostname% a.out
00000001 00000000 z 9 9 9.9 9.9
Simple Types with
–xl
With the -xl option, the Pascal real must be paired with a C float , and the
Pascal integer must be paired with a C short int .
Strings of Characters
The C counterpart to the Pascal alfa and string types are arrays; C passes all arrays by reference. The C counterpart to the Pascal varying is a structure;
C passes structures by value.
Before you call Pascal with a null varying string, set the byte count to zero because that is what Pascal assumes about such strings.
C can pass a structure consisting of a four-byte integer and an array of characters to a Pascal procedure, expecting a var parameter that is a variablelength string.
See the following example:
The Pascal procedure,
StrVar.p
type
TVarStr = varying [25] of char; procedure StrVar(
var a: alfa;
var s: string;
var v: TVarStr); begin
a := 'abcdefghi' + chr(0);
s := 'abcdefghijklmnopqrstuvwxyz' + chr(0);
v := 'varstr' + chr(0); end; { StrVar }
Pascal 4.0 User’s Guide
The C main program,
StrVarMain.c
#include <stdio.h>
#include <string.h> struct TVarLenStr {
int nbytes;
char a[25];
}; extern void StrVar(char *, char *, struct TVarLenStr *); int main(void)
{
struct TVarLenStr vls;
char s10[10], s80[80], s25[25];
vls.nbytes = 0;
StrVar(s10, s80, &vls);
strncpy(s25, vls.a, vls.nbytes);
printf(" s10 = '%s' \n s80 = '%s' \n s25 = '%s' \n", s10, s80, s25);
printf(" strlen(s25) = %d \n", strlen(s25));
}
The commands to compile and execute StrVar.p
and
StrVarMain.c
hostname% pc -c StrVar.p hostname% cc StrVar.o StrVarMain.c -lpc hostname% a.out
s10='abcdefghi'
s80='abcdefghijklmnopqrtstuvwxyz'
s25='varstr'
strlen(s25)=6
Fixed Arrays
For a fixed array parameter, pass the same type and size by reference, as shown in the following example:
6
The C–Pascal Interface 97
6
The Pascal procedure,
FixVec.p
type
VecTyp = array [0..8] of integer; procedure FixVec(var V: TVec; var Sum: integer); var
i: integer; begin
Sum := 0;
for i := 0 to 8 do
Sum := Sum + V[i] end; { FixVec }
The C main program,
FixVecMain.c
#include <stdio.h> extern void FixVec(int [], int *); int main(void)
{
int Sum;
static int a[] = {0,1,2,3,4,5,6,7,8};
FixVec(a, &Sum);
printf(" %d \n", Sum);
}
98
The commands to compile and execute FixVec.p
and
FixVecMain.c
hostname% pc -c -calign FixVec.p hostname% cc FixVec.o FixVecMain.c -lpc hostname% a.out
36
Although it does not apply in this example, arrays of aggregates in Pascal have, by default, a size that is always a multiple of four bytes. When you use the -calign option to compile the Pascal code, that difference with C is eliminated.
The following example illustrates this point. The string 'Sunday' only gets through to the C main program when you compile the Pascal routine using
-calign .
Pascal 4.0 User’s Guide
6
The Pascal procedure,
DaysOfWeek.p
type
TDay= array [0..8] of char;
TWeek = array [0..6] of day;
TYear = array [0..51] of week; procedure DaysOfWeek(var Y: TYear); begin v[1][1] := 'Sunday'; end;
The C main program,
DaysOfWeekMain.c
#include <stdio.h> extern void DaysOfWeek(char [][7][9]); int main(void)
{
char Year[52][7][9];
DaysOfWeek(Year);
printf(" Day = '%s' \n", Year[1][1]);
}
The commands to compile and execute DaysOfWeek.p
and
DaysOfWeekMain.c
without
-calign hostname% pc -c DaysOfWeek.p hostname% cc DaysOfWeek.o DaysOfWeekMain.c -lpc hostname% a.out
Day = ''
The commands to compile and execute DaysOfWeek.p
and
DaysOfWeekMain.c
with
-calign hostname% pc -c -calign DaysOfWeek.p hostname% cc DaysOfWeek.o DaysOfWeekMain.c -lpc hostname% a.out day = 'Sunday '
The C–Pascal Interface 99
100
6
The
univ
Arrays
You can pass any size array to a Pascal procedure expecting a univ array, although there is no special gain in doing so, because there is no type or size checking for separate compilations. However, if you want to use an existing
Pascal procedure that has a univ array, you can do so. All univ arrays that are in , out , in out , or var parameters pass by reference.
The Pascal procedure,
UniVec.p
, which defines a 10element array type
TVec = array [0..9] of integer; procedure UniVec(
var V: univ TVec;
in Last: integer;
var Sum: integer); var
i: integer; begin
Sum := 0;
for i := 0 to Last do
Sum := Sum + V[i]; end; { UniVec }
The C main program,
UniVecMain.c
, which passes a 3-element array to the Pascal procedure written to do a 10element array
#include <stdio.h> extern void UniVec(int *, int, int *); int main(void)
{
int Sum;
static int a[] = {7, 8, 9};
UniVec(a, 2, &Sum);
printf(" %d \n", Sum);
}
Pascal 4.0 User’s Guide
6
The commands to compile and execute UniVec.p
and
UniVecMain.c
with -calign hostname% pc -c -calign UniVec.p hostname% cc UniVec.o UniVecMain.c -lpc hostname% a.out
24
Conformant Arrays
For single-dimension conformant arrays, pass upper and lower bounds, placed after the declared parameter list. If the array is multidimensional, pass element widths as well, one element width for each dimension, except the last one.
See this example: function ip(var x: array [lb..ub: integer] of real): real; extern double ip(double [], int, int);
...
double v1[10];
double z;
z = ip(v1, 0, 9);
...
One bounds pair may apply to several arrays if they are declared in the same parameter group: function ip(var x,y:array[lb..ub:integer] of real):real;
...
double v1[10], v2[10] ;
extern double ip() ;
double z ;
z = ip ( v1, v2, 0, 9 ) ;
...
With multidimensional arrays, for all dimensions but the last one, pass the low bound, high bound, and element width.
The C–Pascal Interface 101
102
6
The Pascal procedure,
IntCA.p
. Pascal passes the bounds pair .
Examples of single-dimension, multidimension, and array-of-character conformant arrays follow. Conformant arrays are included here only because they are a relatively standard feature; there are usually more efficient and simpler ways to do the same thing.
Example 1: Single-Dimension Array procedure IntCA(var a: array [lb..ub: integer] of integer); begin
a[1] := 1;
a[2] := 2 end; { IntCA }
The C main program,
IntCAMain.c
#include <stdio.h> extern void IntCA(int [], int, int); int main(void)
{
int k ;
static int s[] = { 0, 0, 0 };
IntCA (s, 0, sizeof(s)-1);
for (k=0 ; k < 3 ; k++)
printf(" %d \n", s[k]);
}
The commands to compile and execute IntCA.p
and
IntCAMain.c
with -calign hostname% pc -c -calign IntCA.p hostname% cc IntCA.o IntCAMain.c -lpc hostname% a.out
0
1
2
Pascal 4.0 User’s Guide
Example 2: Multi-Dimension Array
The Pascal procedure,
RealCA.p
. Pascal passes low bound, high bound, and element width.
procedure RealCA(var A: array [r1..r2: integer] of
array [c1..c2: integer] of real); var
col, row: integer; begin
for row := r1 to r2 do
for col := c1 to c2 do
if row = col then
A[row, col] := 1.0
else
A[row, col] := 0.0
end; { RealCA }
6
The C main program,
RealCAMain.c
. Array M has 2 rows of 3 columns each.
c1 and c2 are the first and last columns.
r1 and r2 are the first and last rows.
wc is the width of a column element (smallest) and is equal to sizeof( M[0][0] ) .
wr is the width of a row element (next largest) and is equal to
(c2-c1+1) * wc .
#include <stdio.h>
#define NC 3
#define NR 2 extern void RealCA(double [][NC], int, int, int, int, int); int main(void)
{
double
int
M[NR][NC]; col, c1, c2, row, r1, r2, wc, wr;
c1 = 0;
r1 = 0;
c2 = NC - 1;
r2 = NR - 1;
wc = sizeof(M[0][0]);
wr = (c2 - c1 + 1) * wc;
RealCA(M, r1, r2, wr, c1, c2);
for (row = r1; row <= r2; row++) {
printf("\n");
};
printf("\n");
}
for (col = c1; col <= c2; col++)
printf("%4.1f", M[row][col]);
The C–Pascal Interface 103
104
6
The commands to compile and execute RealCA.p
and
RealCAMain.c
with -calign hostname% pc -c -calign RealCA.p hostname% cc RealCA.o RealCAMain.c -lpc hostname% a.out
1.0
0.0
0.0
0.0
1.0
0.0
If wc is the width of the smallest element, as determined by sizeof() , then the width of the next largest element is the number of those smaller elements in the next larger element multiplied by wc .
width of next largest element = (ub - lb + 1) * wc
In general, ( lb , ub , wc ) are the bounds and element width of the next lower dimension of the array. This definition is recursive.
Example 3: Array of Characters
The Pascal procedure,
ChrCAVar.p
procedure ChrCAVar(var a: array [lb..ub: integer] of char); begin
a[0] := 'T';
a[13] := 'o'; end; { ChrCAVar }
The C main program,
ChrCAVarMain.c
. For C, the lower bound is always 0.
#include <stdio.h> extern void ChrCAVar(char [], int, int); int main(void)
{
static char s[] = "this is a string" ;
ChrCAVar( s, 0, sizeof(s)-1) ; /*(s, lower, upper)*/
printf("%11s \n", s) ;
}
Pascal 4.0 User’s Guide
6
The commands to compile and execute ChrCAVar.p
and
ChrCAVarMain.c
hostname% pc -c -calign ChrCAVar.p hostname% cc ChrCAVar.o ChrCAVarMain.c -lpc hostname% a.out
This is a string
Records and Structures
In most cases, a Pascal record describes the same objects as its C structure equivalent, provided that the components have compatible types and are declared in the same order. The compatibility of the types depends mostly on size and alignment. For more information on size and alignments of simple components, see “Compatibility of Types for C and Pascal” on page 90.
By default, the alignment of a record is always four bytes and the size of a record is always a multiple of four bytes. However, when you use -calign in compiling the Pascal code, the size and alignment of the Pascal record matches the size and alignment of the equivalent C structure.
A Pascal record of an integer and a character string matches a C structure of the same constructs, as follows:
The Pascal procedure,
StruChr.p
. It is safer for the
Pascal procedure to explicitly provide the null byte and include it in the count before the string is passed to C.
type
TLenStr = record
nbytes: integer;
chrstr: array [0..24] of char
end; procedure StruChr(var v: TLenStr); begin
v.NBytes := 14;
v.ChrStr := 'St. Petersburg' + chr(0); end; { StruChr }
The C–Pascal Interface 105
6
The C main program,
StruChrMain.c
#include <stdio.h>
#include <string.h> struct TVarLenStr {
int NBytes;
char a[25];
}; extern void StruChr(struct TVarLenStr *); int main(void)
{
struct TVarLenStr vls;
char s25[25];
vls.NBytes = 0;
StruChr(&vls);
strncpy(s25, vls.a, vls.NBytes);
printf(" s25 = '%s' \n", s25);
printf(" strlen(s25) = %d \n", strlen(s25));
}
The commands to compile and execute StruChr.p
and
StruChrMain.c
hostname% pc -c StruChr.p hostname% cc StruChr.o StruChrMain.c -lpc hostname% a.out
s25='St. Petersburg'
strlen(s25) = 13
The record in the example above has, by default, the same size and alignment as the equivalent C record. Some records, though, are laid out differently unless you use the -calign option.
106 Pascal 4.0 User’s Guide
6
The Pascal routine,
DayWeather.p
The C main program,
DayWeatherMain.c
Consider this example: type
TDayWeather = record
TDay: array [0..8] of char;
TWeather: array [0..20] of char;
end;
TDayWeatherArray = array [0..1] of TDayWeather; procedure DayWeather(var W: TDayWeatherArray;
var WeatherSize: integer); begin
W[1].TDay := 'Sunday' + chr(0);
W[1].TWeather := 'Sunny' + chr(0);
WeatherSize := 5; end; { StruChr }
#include <stdio.h>
#include <string.h> struct TDayRec {
char TDay[9];
char TWeather[21];
}; extern void DayWeather(struct TDayRec [], int *); int main(void)
{
char s25[25];
char t25[25];
struct TDayRec dr[2];
int nbytes = 0;
DayWeather(dr, &nbytes);
strncpy(s25, dr[1].TDay, 6);
printf(" day = '%s' \n", s25);
strncpy(t25, dr[1].TWeather, nbytes);
printf(" weather = '%s' \n", t25);
}
The C–Pascal Interface 107
108
6
When you compile the Pascal routine without using the -calign option, the program does not work correctly.
The commands to compile and execute DayWeather.p
and
DayWeatherMain.c
without
-calign hostname% pc -c DayWeather.p hostname% cc DayWeather.o DayWeatherMain.c -lpc hostname% a.out
day = ''
weather = ' sun'
The commands to compile and execute DayWeather.p
and
DayWeatherMain.c
with
-calign hostname% pc -calign -c DayWeather.p hostname% cc DayWeather.o DayWeatherMain.c -lpc hostname% a.out
day = 'Sunday'
weather = 'sunny'
Variant Records
C equivalents of variant records can sometimes be constructed, although there is some variation with architecture and sometimes a need to adjust alignment.
You can avoid the need to adjust alignment by using the -calign option.
The Pascal procedure,
VarRec.p
type
vr = record
case tag: char of
'a': (ch1, ch2: char);
'b': (flag: boolean);
'K': (ALIGN: integer);
end; procedure VarRec(var x: vr); begin
if x.ch1 = 'a' then
x.ch2 := 'Z' end; { VarRec }
Pascal 4.0 User’s Guide
The C main program,
VarRecMain.c
#include <stdio.h>
struct vlr {
char tag;
union {
struct {
char ch1, ch2;
}a_var;
struct {
char flag;
}b_var;
struct {
int ALIGN;
}c_var;
}var_part;
}; extern void VarRec(struct vlr *); int main(void)
{
struct vlr *x;
x = (struct vlr *)malloc(sizeof(struct vlr));
x->tag = 'a';
x->var_part.a_var.ch1 = 'a';
x->var_part.a_var.ch2 = 'b';
VarRec(x);
printf(" %c \n", x->var_part.a_var.ch2);
}
The commands to compile and execute VarRec.p
and
VarRecMain.c
hostname% pc -c -calign VarRec.p hostname% cc VarRec.o VarRecMain.c -lpc hostname% a.out
Z
6
The C–Pascal Interface 109
6
110
Pascal Set Type
In Pascal, a set type is implemented as a bit vector, which is similar to a C short-word array. Direct access to individual elements of a set is highly machine-dependent and should be avoided.
In Pascal, bits are numbered within a byte from the most significant to least, as shown in Table 6-3.
Table 6-3 Set Implementation
Set set+3: set+2: set+1: set+0:
Bit Numbering
31, 30, 29, 28, 27, 26, 25, 24
23, 22, 21, 20, 19, 18, 17, 16
15, 14, 13, 12, 11, 10, 9, 8
7, 6, 5, 4, 3, 2, 1, 0
In C, a set could be described as a short-word array beginning at an even address. With the current set representation, it does not matter what the lower-bound value is.
The nth element in a set [lower...upper] can be tested as follows:
#define LG2BITSLONG 5 /* log2( bits in long word) */
#define LG2BITSWORD 4 /* log2( bits in short word) */
#define MSKBITSLONG 0x1f
#define MSKBITSHORT 0x0 short *setptr; /* set as array of shorts */ int upper; /* upper bound of the set */ int elem; /* ordinal value of set element */ int i;
} if ( setptr[elem >> LG2BITSWORD] &
(1 << (elem & MSKBITSWORD)) ) {
/* elem is in set */
Pascal 4.0 User’s Guide
6
Pascal
intset
Type
The Pascal intset type is predefined as set of [0..127] . A variable of this type takes 16 bytes of storage.
The Pascal procedure,
IntSetVar.p
, which has an intset of the elements
[1, 3, 7, 8] procedure IntSetVar(var s: intset); begin
s := [1, 3, 7, 8] end; { IntSetVar }
The C main program,
IntSetVarMain.c
#include <stdio.h> extern void IntSetVar(unsigned int *); int main(void)
{
int w ;
unsigned int *p, *s ;
s = (unsigned int *) malloc(16);
IntSetVar(s) ;
for (w = 0, p = s ; w < 4 ; w++, p++)
printf("%012o %3d \n", *p, w);
printf(" 110 001 010 (binary, word 4) \n");
printf(" 876 543 210 (bits, word 4)" \n");
}
The commands to compile and execute IntSetVar.p
and
IntSetVarMain.c
. The output of this example depends on the architecture of your machine.
hostname% pc -c IntSetVar.p hostname% cc IntSetVar.o IntSetVarMain.c -lpc hostname% a.out
000000000000 0
000000000000 1
000000000000 2
000000000612 3
110 001 010 (binary, word 4)
876 543 210 (bits, word 4)
The C–Pascal Interface 111
6
Value Parameters
There are three types of value parameters in Pascal.
Simple Types without
–xl
Without –xl , simple types match, as in the following example:
The Pascal procedure,
SimVal. p .
t , f , c , i , r , and s are value parameters .
procedure SimVal( t, f: boolean; c: char; si: integer16; i: integer; sr: shortreal; r: real; var reply: integer); begin
Reply := 0;
if t then
Reply := Reply + 1;
if not f then
Reply := Reply + 8;
if c='z' then
Reply := Reply + 64;
if si=9 then
Reply := Reply + 512;
if i=9 then
Reply := Reply + 4096;
if sr=shortreal(9.9) then
Reply := Reply + 32768;
if r=9.9 then
Reply := Reply + 262144; end; { SimVal }
112 Pascal 4.0 User’s Guide
6
The C main program,
SimValMain.c
#include <stdio.h> extern void SimVal(
char, char, char,
short,
int,
float,
double,
int *); int main(void)
{
char t = 1, f = 0;
char c = 'z';
short si = 9;
int i = 9;
float sr = 9.9;
double r = 9.9;
int args;
SimVal(t, f, c, si, i, sr, r, &args);
printf(" args = %06o \n", args);
The commands to compile and execute SimVal.p
and
SimValMain.c
hostname% pc -c SimVal.p hostname% cc SimVal.o SimValMain.c -lpc hostname% a.out
args=111111
If no function prototype is provided for SimVal in SimValMain.c
, then sr:shortreal must be changed to sr:real in SimVal.p
. This change is necessary because in C, a float is promoted to double in the absence of function prototypes. In -xl mode, change sr:shortreal to sr:longreal .
Simple Types with
–xl
With -xl , the Pascal real must be paired with a C float , and the Pascal integer must be paired with a C short int .
The C–Pascal Interface 113
114
6
The Pascal procedure,
ChrCAVal.p
The C main program,
ChrCAValMain.c
Arrays
Since C cannot pass arrays by value, it cannot pass strings of characters, fixed arrays, or univ arrays by value.
Conformant Arrays
Pascal passes all value parameters on the stack or in registers, except for value conformant array parameters, which are handled by creating a copy in the caller environment and passing a pointer to the copy. In addition, the bounds of the array must be passed (see “Conformant Arrays” on page 101).
This example is the same as the single-dimension example in “Conformant
Arrays,” except that the var prefix is deleted.
procedure ChrCAVal(a: array [lb..ub: integer] of char); begin
a[0] := 'T';
a[13] := 'o'; end; { ChrCAVal }
#include <stdio.h> extern void ChrCAVal(char [], int, int); int main(void)
{
static char s[] = "This is a string";
ChrCAVal(s, 0, sizeof(s) -1);
printf(" %11s \n", s);
}
Pascal 4.0 User’s Guide
6
The commands to compile and execute ChrCAVal.p
and
ChrCAValMain.c
with
-calign hostname% pc -c -calign ChrCAVal.p hostname% cc ChrCAVal.o ChrCAValMain.c -lpc hostname% a.out
This is a string
Function Return Values
Function return values match types the same as with parameters, and they pass in much the same way.
Simple Types
The simple types pass in a straightforward way, as follows:
The Pascal function,
RetReal.p
function RetReal(x: real): real; begin
RetReal := x + 1.0
end; { RetReal }
The C main program,
RetRealMain.c
#include <stdio.h> extern double RetReal(double); int main(void)
{
double r, s;
r = 2.0;
s = RetReal(r);
printf(" %f \n", s);
}
The C–Pascal Interface 115
116
6
The commands to compile and execute RetReal.p
and
RetRealMain.c
hostname% pc -c RetReal.p hostname% cc RetReal.o RetRealMain.c hostname% a.out
3.000000
Input and Output
If your C main program calls a Pascal procedure that does I/O, then include the following code in the C main program before you call the Pascal procedure:
__PC0__PCSTART();
Also, in the C main program just before exit, add the following line:
__PC0__PCEXIT();
See this example:
The Pascal procedure, IO.p
procedure IO; begin
writeln('Hello Pascal and St. Petersburg!'); end;
The C main program, IOMain.c
#include <stdio.h> extern void IO(); int main(void)
{
IO(); printf("Hello C! \n");
}
Pascal 4.0 User’s Guide
The commands to compile and execute IO.p
and IOMain.c
hostname% pc -c IO.p hostname% cc IO.o IOMain.c -lpc hostname% a.out
Hello Pascal and St. Petersburg!
Hello C!
Procedure Calls: Pascal–C
This section parallels the section, “Procedure Calls: C–Pascal” on page 93.
Earlier comments and restrictions also apply here.
Variable Parameters
Pascal passes all variable parameters by reference, which C can do, too.
Simple Types
Simple types pass in a straightforward manner, as follows:
The C function, SimRef.c
void SimRef(
char
char
char
short
int
float
double
{
*t = 1;
*f = 0;
*c = 'z';
*si = 9;
*i = 9;
*sr = 9.9;
*r = 9.9;
}
*t,
*f,
*c,
*si,
*i,
*sr,
*r)
6
The C–Pascal Interface 117
6
The Pascal main program,
SimRefMain.p
program SimRefMain(output); var
t, f: boolean;
c: char;
si: integer16;
i: integer;
sr: shortreal;
r: real; procedure SimRef(
var t, f: boolean;
var c: char;
var si: integer16;
var i: integer;
var sr: shortreal;
var r: real);
external c; begin
SimRef(t, f, c, si, i, sr, r);
writeln(t, f: 6, c: 2, si: 2, i: 2, sr :4:1, r :4:1); end. { SimRefMain }
The commands to compile and execute SimRef.c
and
SimRefMain.p
hostname% cc -c SimRef.c hostname% pc SimRef.o SimRefMain.p hostname% a.out true false z 9 9 9.9 9.9
Strings of Characters
The alfa and string types pass simply; varying strings are more complicated. All pass by reference.
118 Pascal 4.0 User’s Guide
The C function, StrVar.c
#include <string.h> struct TVarLenStr {
int nbytes;
char a[26];
}; void StrVar(char *s10, char *s80, struct TVarLenStr *vls)
{
static char ax[11] = "abcdefghij";
static char sx[81] = "abcdefghijklmnopqrstuvwxyz";
static char vx[6] = "varstr";
strncpy(s10, ax, 11);
strncpy(s80, sx, 80);
strncpy(vls->a, vx, 6);
vls->nbytes = 6;
}
The Pascal main program,
StrVarMain.p
program StrVarMain(output); type
TVarStr = varying[26] of char; var
a: alfa;
s: string;
v: TVarstr; procedure StrVar(var a: alfa; var s: string; var v: TVarStr); external c; begin
StrVar(a, s, v);
writeln(a);
writeln(s);
writeln(v);
writeln(' length(v) = ', length(v) :2); end. { StrVarMain }
6
The C–Pascal Interface 119
120
6
The commands to compile and execute StrVar.c
and
StrVarMain.p
hostname% cc -c StrVar.c hostname% pc StrVar.o StrVarMain.p hostname% a.out abcdefghij abcdefghijklmnopqrtstuvwxyz varstr
length(v) = 6
Avoid constructs that rely on strings being in static variable storage. For example, you could use mktemp (3) in Pascal as follows:
Incorrect use of string in static variable storage tmp := mktemp('/tmp/eph.xxxxxx')
This use is incorrect, since mktemp() modifies its argument. Instead, use the C library routine strncpy() (see string (3)) to copy the string constant to a declared char array variable, as in:
Correct solution using the C library routine strncpy() program Use_mktemp ; procedure strncpy( var dest: univ string ; var srce: univ string ; length: integer) ; external c ; procedure mktemp(var dest: univ string); external c;
...
var path: string ; begin
...
strncpy( path, '/tmp/eph.xxxxxx', sizeof(path)) ; mktemp( path ) ;
...
end .
Pascal 4.0 User’s Guide
The C function, FixVec.c
6
Fixed Arrays
For a fixed-array parameter, pass the same type and size, as in this example: void FixVec(int V[9], int *Sum)
{
int i;
*Sum = 0;
for (i = 0; i <= 8; i++)
*Sum = *Sum + V[i];
}
The Pascal main program,
FixVecMain.p
program FixVecMain(output); type
TVec = array [0..8] of integer; var
V: TVec := [0, 1, 2, 3, 4, 5, 6, 7, 8];
Sum: integer; procedure FixVec(var XV: TVec; var XSum: integer); external c; begin
FixVec(V, Sum);
writeln(Sum: 3); end. { FixVecMain }
The commands to compile and execute FixVec.c
and
FixVecMain.p
hostname% cc -c FixVec.c hostname% pc -calign FixVec.o FixVecMain.p hostname% a.out
36
The -calign option is not needed for this example, but may be necessary if the array parameter is an array of aggregates.
The C–Pascal Interface 121
122
6
The C function, UniVec.c
The
univ
Arrays
The univ arrays that are in , out , in out, or var parameters pass by reference.
Here is an example: void UniVec(int V[3], int Last, int *Sum)
{
int i;
*Sum = 0;
for (i = 0; i <= Last; i++)
*Sum += V[i];
}
The Pascal main program,
UniVecMain.p
program UniVecMain(output); type
TVec = array [0..9] of integer; var
Sum: integer;
V: array [0..2] of integer; procedure UniVec(var V: univ TVec; in Last: integer;
var Sum: integer); external c; begin
V[0] := 7;
V[1] := 8;
V[2] := 9;
UniVec(V, 2, Sum);
writeln(Sum); end. { UniVecMain }
The commands to compile and execute UniVec.c
and
UniVecMain.p
hostname% cc -c UniVec.c hostname% pc -calign UniVec.o UniVecMain.p hostname% a.out
24
Pascal 4.0 User’s Guide
The C function, IntCA.c
6
The -calign option is not needed for this example, but may be necessary if the array parameter is an array of aggregates.
Conformant Arrays
For single-dimension conformant arrays, pass upper and lower bounds placed after the declared parameter list. If the array is multidimensional, pass element widths as well, one element width for each dimension, except the last one. Chapter 8, “The FORTRAN–Pascal Interface,” has an example of multidimensional conformant array passing.
The following example uses a single-dimension array: void IntCA(int a[], int lb, int ub)
{ int k;
for (k=0; k <= ub - lb; k++) a[k] = 4;
}
The Pascal main program,
IntCAMain.p
. Note that what
Pascal passes as s , is received in C as a , lb , ub .
program IntCAMain(output); var
s: array [1..3] of integer;
i: integer; procedure IntCA(var a: array [lb..ub: integer] of integer); external c; begin
IntCA(s);
for i := 1 to 3 do
write(s[i]);
writeln end. { IntCAMain }
The C–Pascal Interface 123
124
6
The commands to compile and execute IntCA.c
and
IntCAMain.p
hostname% cc -c IntCA.c hostname% pc -calign IntCA.o IntCAMain.p hostname% a.out
4 4 4
The -calign option is not needed for this example, but may be necessary if the array parameter is an array of aggregates.
Records and Structures
In most cases, a Pascal record describes the same objects as its C structure equivalent, provided that the components have compatible types and are declared in the same order. For more information, see “Compatibility of Types for C and Pascal” on page 90.
Records that contain aggregates may differ because aggregates in C and Pascal sometimes have different sizes and alignments. If you compile the Pascal code with the -calign option, the differences are eliminated.
A Pascal record of an integer and a character string matches a C structure of an integer and an array of char values, as follows:
The C function, StruChr.c
#include <string.h> struct TVarLenStr {
int nbytes;
char a[26];
}; void StruChr(struct TVarLenStr *v)
{
strncpy(v->a, "strvar", 6);
v->nbytes = 6;
}
Pascal 4.0 User’s Guide
6
The Pascal main program,
StruChrMain.p
program StruChrMain(output); type
TVarLenStr = record
nbytes: integer;
a: array [0..25] of char
end; var
vls: TVarLenStr;
i: integer; procedure StruChr(var vls: TVarLenStr); external c; begin
StruChr(vls);
write(' string=''');
for i := 0 to vls.nbytes - 1 do
write(vls.a[i]);
writeln('''');
writeln(' length = ', vls.nbytes) end. { StruChrMain }
The commands to compile and execute StruChr.c
and
StruChrMain.p
hostname% cc -c StruChr.c hostname% pc -calign StruChr.o StruChrMain.p hostname% a.out
string=' strvar'
length= 6
Variant Records
C equivalents of variant records can sometimes be constructed, although there is some variation with the architecture, and sometimes you have to adjust the alignment.
The C–Pascal Interface 125
6
The C function, VarRec.c
Following are some examples: struct vlr {
char tag;
union { struct {
char ch1, ch2;
} a_var; struct {
char flag;
} b_var; struct {
int ALIGN;
} c_var;
} var_part;
}; void VarRec(struct vlr *x)
{
if (x->var_part.a_var.ch1 == 'a') x->var_part.a_var.ch2 = 'Z';
}
126 Pascal 4.0 User’s Guide
6
The Pascal main program,
VarRecMain.p
program VarRecMain; type
vr = record
case tag: char of
'a': (ch1, ch2: char);
'b': (flag: boolean);
'K': (ALIGN: integer)
end; var
x: vr; procedure VarRec(var d: vr); external c; begin
x.tag := 'a';
x.ch1 := 'a';
x.ch2 := 'b';
VarRec(x);
writeln(x.ch2) end. { VarRecMain }
The commands to compile and execute VarRec.c
and
VarRecMain.p
hostname% cc -c VarRec.c hostname% pc -calign VarRec.o VarRecMain.p hostname% a.out
Z
The -calign option is not needed in the previous example, but may be necessary if the record contains aggregates.
Non-Pascal Procedures
When you use the -xl option in compiling Pascal code, you can use the nonpascal keyword to declare that an external procedure is written in another language. This keyword generally causes everything to be passed by reference.
The C–Pascal Interface 127
128
6
See this example:
The C function, NonPas.c
. In the function for_C , s is a pointer (declared var in the procedure declaration), and len is not a pointer (not declared var in the procedure declaration). In the function for_nonpascal , s is still a pointer (though not declared var in the procedure declaration), and len is now a pointer (though not declared var ).
#include <stdio.h> void for_C(char *s, int len)
{
int i;
for (i = 0; i < len; i++) putchar(s[i]);
putchar('\n');
} void for_NonPascal(char *s, int *len)
{
int i;
for (i = 0; i < *len; i++) putchar(s[i]);
putchar('\n');
}
The Pascal main program,
NonPasMain.p
program NonPasMain; var
s: string; procedure for_C(var s: string; len: integer); external c; procedure for_NonPascal(var s: string; len: integer); nonpascal; begin
s :='Hello from Pascal';
for_C(s, 18);
for_NonPascal(s, 18); end. { NonPasMain }
The commands to compile and execute NonPas.c
and
NonPasMain.p
hostname% cc -c NonPas.c hostname% pc NonPas.o NonPasMain.p hostname% a.out
Hello from Pascal
Hello from Pascal
Pascal 4.0 User’s Guide
Value Parameters
In general, Pascal passes value parameters in registers or on the stack, widening to a full word if necessary.
Simple Types
With value parameters, simple types match, as in the following example:
6
The C function, SimVal.c
void SimVal(
char
char
char t, f, c,
short
int
float
double
int
{
*reply = 0;
if (t) si, i, sr, r,
*reply)
if (!f)
if (c == 'z')
if (si == 9)
if (i == 9)
*reply += 01;
*reply += 010;
*reply += 0100;
if (sr ==(float)9.9) *reply += 0100000;
if (r == 9.9) *reply +=01000000;
}
*reply += 01000;
*reply += 010000;
The C–Pascal Interface 129
130
6
The Pascal main program,
SimValMain.p
program SimVal(output); var
t: boolean
f: boolean
:= true;
:= false;
c: char := 'z'; si: integer16 := 9;
i: integer := 9;
sr: shortreal := 9.9;
r: double
args: integer;
:= 9.9; procedure SimVal(
t, f: boolean;
c: char;
si: integer16;
i: integer;
sr: shortreal;
r: double;
var Reply: integer);
external c; begin
SimVal(t, f, c, si, i, sr, r, args);
writeln(' args = ', args :6 oct); end. { SimVal }
The commands to compile and execute SimVal.c
and
SimValMain.p
hostname% cc -c SimVal.c hostname% pc SimVal.o SimValMain.p hostname% a.out
args=111111
Function Return Values
Function return values match types in the same manner as with parameters, and they pass in much the same way. See “Variable Parameters” on page 94.
The following example shows how to pass simple types.
Pascal 4.0 User’s Guide
6
The C function, RetReal.c
double RetReal(double *x)
{
return(*x + 1.0);
}
The Pascal main program,
RetRealMain.p
program RetRealMain; var
r, s: real; function RetReal(var x: real): real; external c; begin
r := 2.0;
s := RetReal(r);
writeln(r: 4: 1, s: 4: 1) end. { RetRealMain }
The commands to compile and execute RetReal.c
and
RetRealMain.p
hostname% cc -c RetReal.c hostname% pc RetReal.o RetRealMain.p hostname% a.out
2.0 3.0
Parameters That Are Pointers to Procedures
Pascal has a special type that is a pointer to a procedure. A variable of this type can be used as a parameter, as follows:
The C function, ProcPar.c
#include <string.h> void proc_c (void (*p)()) /* a pointer to procedure argument */
{
char *s ;
s = "Called from C";
(*p)( s, strlen(s)); /* Call the Pascal routine */
}
The C–Pascal Interface 131
6
The Pascal main program,
ProcParMain.p
, which calls the
C procedure, proc_c , passing it the address of the Pascal procedure, proc_pas . The C procedure assigns a value to the string s , and calls the procedure whose pointer it just received.
Then the Pascal procedure, proc_pas , writes a literal constant and the string it just received.
program ProcParMain; type
{ Declare a procedure pointer type. }
proc_ptr = ^procedure(var s: string; i: integer);
{Declare an external C procedure which takes a procedure argument.} procedure proc_c(p: proc_ptr); external c; procedure proc_pas(var cstr: string; strlen: integer); var
i: integer; begin
write('Hello from PROC_PASCAL: ');
for i := 1 to strlen do
write(cstr[i])
writeln; end; { proc_pas } begin
{ Call the C routine. }
proc_c(addr(proc_pas)) end. { ProcParMain }
The commands to compile and execute ProcPar.c
and
ProcParMain.p
hostname% cc -c ProcPar.c hostname% pc ProcPar.o ProcParMain.p hostname% a.out
Hello from PROC_PASCAL: Called from C
Procedures and Functions as Parameters
It is probably clearer to pass a pointer to a procedure than to pass the procedure name itself. See “Procedure Calls: Pascal–C” on page 117.
A procedure or function passed as an argument is associated with a static link to its lexical parent’s activation record. When an outer block procedure or function is passed as an argument, Pascal passes a null pointer in the position normally occupied by the passed routine’s static link. So that procedures and
132 Pascal 4.0 User’s Guide
6 functions can be passed to other languages as arguments, the static links for all procedure or function arguments are placed after the end of the conformant array bounds pairs, if any.
Routines in other languages can be passed to Pascal; a dummy argument must be passed in the position normally occupied by the passed routine’s static link.
If the passed routine is not a Pascal routine, the argument is used only as a placeholder.
Global Variables in C and Pascal
If the types are compatible, a global variable can be shared between C and
Pascal.
An example:
The Pascal procedure,
GloVar.p
var
Year: integer; procedure GloVar; begin
Year := 2001 end; { GloVar }
The C main program,
GloVarMain.c
#include <stdio.h> extern void GloVar(); int Year; int main(void)
{
Year = 2042;
GloVar();
printf( " %d \n", Year ) ;
}
The C–Pascal Interface 133
6
The commands to compile and execute GloVar.p
and
GloVarMain.c
without –xl .
With -xl , the Pascal integer must be paired with a C short int and declared public since the default visibility is private .
hostname% pc -c GloVar.p hostname% cc GloVar.o GloVarMain.c hostname% a.out
2001
File-Passing Between Pascal and C
You can pass a file pointer from Pascal to C, then have C do the I/O, as in:
The C procedure,
UseFilePtr.c
#include <stdio.h> void UseFilePtr (FILE *ptr)
{
{ /* Write to the file: */
fprintf( ptr, "[1] Passing the file descriptor \n") ;
fprintf( ptr, "[2] and writing information \n") ;
fprintf( ptr, "[3] to a file \n") ;
}
The Pascal main program,
UseFilePtrMain.p
program UseFilePtrMain; var
f: text;
cfile: univ_ptr; procedure UseFilePtr(cf: univ_ptr); external c; begin
rewrite(f, 'myfile.data'); { Make the file. }
cfile := getfile(f); { Get a file pointer. }
UseFilePtr(cfile); { Call the C function. } end. { UseFilePtrMain }
134 Pascal 4.0 User’s Guide
The commands to compile and execute UseFilePtc.c
and
UseFilePtrMain.p
hostname% cc -c UseFilePtr.c hostname% pc UseFilePtr.o UseFilePtrMain.p hostname% a.out hostname% cat myfile.data
[1] Passing the file descriptor
[2] and writing information
[3] to a file
6
The C–Pascal Interface 135
6
136 Pascal 4.0 User’s Guide
Sample Interface
The C++–Pascal Interface
This chapter describes how to mix C++ and Pascal modules in the same program. It contains the following sections:
Sample Interface
Compatibility of Types for C++ and Pascal
C++ Name Encoding
Procedure Calls: C++–Pascal
Procedure Calls: Pascal–C++
Global Variables in C++ and Pascal
Pascal File Pointers to C++ page 137 page 138 page 138 page 138 page 155 page 161 page 162
7
You must use the compiler option -lpc when you use CC to link a C++ main routine that calls Pascal.
-lpc denotes linking with the Pascal runtime support library libpc . On the Solaris 1.x environment, if you use pc to link, you must add the -lc option.
The -calign option causes pc to use data formats for aggregate objects similar to those in C++.
137
7
Compatibility of Types for C++ and Pascal
Table 6-1 and Table 6-2 on page 90 list the default sizes and alignments of compatible types for C and Pascal. They apply to C++ as well.
C++ Name Encoding
To implement function overloading and type-safe linkage, the C++ compiler normally appends type information to the function names. To prevent the C++ compiler from doing so, and to allow Pascal to call a C++ function, declare the
C++ function with the extern "C" language construct. One common way to do this is in the declaration of a function, like this: extern "C" void f (int);
...
void f (int) { /* ...body of f... */ }
For brevity, you can also combine extern "C " with the definition of the function, as in: extern "C" void f (int)
{ /* ...body of f... */ }
Procedure Calls: C++–Pascal
Following are examples that illustrate how a C++ main program calls a Pascal procedure. Included in each example are the Pascal procedure, the C++ main program, and the commands to compile and execute the final program.
The Pascal procedure, Samp, in the file, Samp.p
procedure Samp (var i: integer; var r: real); begin
i := 7;
r := 3.14; end
138 Pascal 4.0 User’s Guide
7
The C++ main program,
SampMain.cc
#include <stdio.h> extern "C" void Samp (int&, double&); int main(void)
{
int i;
double d;
Samp (i, d);
printf ("%d %3.2f \n", i, d);
}
The commands to compile and execute Samp.p and
SampMain.cc
: c hostname% pc -c Samp.p hostname% CC Samp.o SampMain.cc -lpc hostname% a.out
7 3.14
Arguments Passed by Reference
C++ arguments can be passed by reference. This section describes how they work with Pascal.
The C++–Pascal Interface 139
7
Simple Types without the
-xl
Option
Without the -xl option, simple types match, as in the following example:
The Pascal procedure,
SampRef , in the file, Samp.p
procedure SamRef (
var t, f: boolean;
var c: char;
var i: integer;
var s: integer16;
var r: shortreal;
var d: real
); begin
t := true;
f := false;
c := 'z';
i := 9;
s := 9;
r := 9.9;
d := 9.9; end;
140 Pascal 4.0 User’s Guide
7
The C++ main program,
SamRefMain.cc
#include <stdio.h> extern "C" void SamRef (
char &,
char
char
&,
&,
int
short
&,
&,
float &,
double &); int main(void)
{
char
int
short t, f, c; i; s;
float r;
double d;
SamRef (t, f, c, i, s, r, d); printf ("%08o %08o %c %d %d %3.1f %3.1f \n",
t, f, c, i, s, r, d);
}
The commands to compile and execute SamRef.p and
SamRefMain.cc
hostname% pc -c SamRef.p hostname% CC SimRef.o SamRefMain.cc -lpc hostname% a.out
00000001 00000000 z 9 9 9.9 9.9
Simple Types with the
-xl
Option
With the -xl option, the Pascal real must be paired with a C++ float ; the
Pascal integer must be paired with a C++ short int .
The C++–Pascal Interface 141
7
The Pascal procedure,
StrRef.p
Strings of Characters
The C++ counterpart to the Pascal alfa and string types are arrays. The C++ counterpart to the Pascal varying type is a structure.
Here is an example: type
TVarStr = varying [25] of char; procedure StrRef (
var a: alfa;
var s: string;
var v: TVarStr
); begin
a := 'abcdefghi' + chr(0);
s := 'abcdefghijklmnopqrstuvwxyz' + chr(0);
v := 'varstr' + chr(0); end;
142 Pascal 4.0 User’s Guide
The C++ main program,
StrRefMain.cc
#include <stdio.h>
#include <string.h>
struct TVarLenStr {
int NBytes;
char a[25];
}; extern "C" void StrRef (
char *,
char *,
TVarLenStr &); int main(void)
{
struct TVarLenStr vls;
char s10[10], s80[80], s25[25];
vls.NBytes = 0;
StrRef (s10, s80, vls);
strncpy (s25, vls.a, vls.NBytes);
printf (" s10 = '%s' \n s80 = '%s' \n s25 = '%s' \n",
s10, s80, s25);
printf (" strlen (s25) = %d \n", strlen(s25));
}
The commands to compile and execute StrRef.p
and
StrRefMain.cc
hostname% pc -c StrRef.p hostname% CC StrRef.o StrRefMain.cc -lpc hostname% a.out s10 = 'abcdefghi' s80 = 'abcdefghijklmnopqrstuvwxyz' s25 = 'varstr' strlen (s25) = 6
7
The C++–Pascal Interface 143
144
7
The Pascal procedure,
FixVec.p
Fixed Arrays type
TVec = array [0..8] of integer; procedure FixVec (
var V: TVec;
var Sum: integer
);
var
i: integer; begin
Sum := 0;
for i := 0 to 8 do
Sum := Sum + V[i]; end;
The C++ main program,
FixVedMain.cc
#include <stdio.h> extern "C" void FixVec (
int [],
int &); int main(void)
{
int Sum;
static int a[] = {1,2,3,4,5,6,7,8,9};
FixVec (a, Sum);
printf (" %d \n", Sum);
}
The commands to compile and execute FixVec.p
and
FixVecMain.cc
hostname% pc -c FixVec.p hostname% CC FixVec.o FixVecMain.cc -lpc hostname% a.out
45
Pascal 4.0 User’s Guide
The Pascal procedure,
DaysOfWeek.p
The C++ main program,
DaysOfWeekMain.cc
7
Although it does not apply to this example, arrays of aggregates in Pascal have, by default, a size that is a multiple of four bytes. When you use the
-calign option to compile Pascal code, that difference from C++ is eliminated.
The following example illustrates this point. The string 'Sunday' only gets through to the C++ main program when you compile the Pascal routine using the -calign option.
type
TDay = array [0..8] of char;
TWeek = array [0..6] of TDay;
TYear = array [0..51] of TWeek; procedure DaysOfWeek (
var Y: TYear
); begin
Y[1][1] := 'Sunday'; end;
#include <stdio.h> extern "C" void DaysOfWeek (
char [52][7][9]); int main(void)
{
char Year [52][7][9];
DaysOfWeek (Year);
printf (" Day = '%s' \n", Year[1][1]);
}
The C++–Pascal Interface 145
7
The commands to compile and execute DaysOfWeek.p
and
DaysOfWeekMain.cc
without the -calign option hostname% pc -c DaysOfWeek.p hostname% CC DaysOfWeek.o DaysOfWeekMain.cc -lpc hostname% a.out
Day = ''
The commands to compile and execute DaysOfWeek.p
and
DaysOfWeekMain.cc
with the
-calign option hostname% pc -c -calign DaysOfWeek.p hostname% CC DaysOfWeek.o DaysOfWeekMain.cc -lpc hostname% a.out
Day = 'Sunday'
Records and Structures
A Pascal record of an integer and a character string matches a C++ structure of the same constructs, as in this example:
The Pascal procedure,
StruChr.p
. It is safer for the
Pascal procedure to explicitly provide the null byte and include it in the count before the string is passed to C++.
type
TLenStr = record
NBytes: integer;
ChrStr: array [0..24] of char;
end; procedure StruChr (
var v: TLenStr
); begin
v.NBytes := 14;
v.ChrStr := 'St.Petersburg' + chr(0); end;
146 Pascal 4.0 User’s Guide
The C++ main program,
StruChrMain.cc
#include <stdio.h>
#include <string.h>
struct TVarLenStr {
int NBytes;
char a[25];
}; extern "C" void StruChr (
TVarLenStr &); int main(void)
{
struct TVarLenStr vls;
char s25[25];
vls.NBytes = 0;
StruChr (vls);
strncpy (s25, vls.a, vls.NBytes);
printf ("s25 = '%s' \n", s25);
printf ("strlen (s25) = %d \n", strlen(s25));
}
The commands to compile and execute StruChr.p
and
StruChr.cc
hostname% pc -c StruChr.p hostname% CC StruChr.o StruChrMain.cc -lpc hostname% a.out s25 = 'St.Petersburg' strlen (s25) = 13
7
The C++–Pascal Interface 147
7
The Pascal procedure ,
DayWeather.p
Consider this example: type
TDayWeather = record
TDay: array [0..8] of char;
TWeather:array [0..20] of char;
end;
TDayWeatherArray = array [0..1] of TDayWeather; procedure DayWeather (
var W: TDayWeatherArray;
var WeatherSize: integer
); begin
W[1].TDay := 'Sunday';
W[1].TWeather := 'Sunny';
WeatherSize := 5; end;
148 Pascal 4.0 User’s Guide
The C++ main program,
DayWeatherMain.cc
#include <stdio.h>
#include <string.h>
struct TDayRec {
char TDay[9];
char TWeather[21];
}; extern "C" void DayWeather (
TDayRec [2],
int &); int main(void)
{
struct TDayRec dr[2];
int NBytes;
char s25[25];
char t25[25];
NBytes = 0;
DayWeather (dr, NBytes);
strncpy (s25, dr[1].TDay, 6);
printf (" day = '%s' \n", s25);
strncpy (t25, dr[1].TWeather, NBytes);
printf (" weather = '%s' \n", t25);
}
7
The C++–Pascal Interface 149
7
When you compile the Pascal routine without the
-calign option, the program does not work correctly.
hostname% pc -c DayWeather.p hostname% CC DayWeather.o DayWeatherMain.cc -lpc hostname% a.out day = '' weather = ' Sun'
Compile with the -calign option. The program now works correctly.
hostname% pc -calign -c DayWeather.p hostname% CC DayWeather.o DayWeatherMain.cc -lpc hostname% a.out
day = 'Sunday'
weather = 'Sunny'
Arguments Passed by Value
C++ arguments can be passed by value. In this section, we describe how they work with Pascal.
150 Pascal 4.0 User’s Guide
The Pascal procedure,
SimVal.p
Simple Types without the
-xl
Option
Without the -xl option, simple types match, as in the following example:
7 procedure SimVal(
t, f: boolean;
c: char;
si:integer16;
i: integer;
sr:shortreal;
r: real;
var Reply: integer); begin
Reply := 0;
if t then
Reply := Reply + 1;
if not f then
Reply := Reply + 8
if c='z' then
Reply := Reply + 64;
if si=9 then
Reply := Reply + 512;
if i=9 then
Reply := Reply + 4096;
if sr=shortreal(9.9) then
Reply := Reply + 32768;
if r=9.9 then
Reply := Reply + 262144; end;
The C++–Pascal Interface 151
152
7
The C++ main program,
SimValMain.cc
#include <stdio.h> extern "C" void SimVal(
char,
char,
char,
short,
int,
float,
double,
int &); int main(void)
{
char t = 1, f = 0, c= 'z';
short si = 9;
int
float i=9; sr = 9.9;
double r =9.9;
int args;
SimVal (t, f, c, si, i, sr, r, args);
printf (" args = %07o \n", args);
return 0;
}
The commands to compile and execute SimVal.p
and
SimVal.cc
hostname% pc -c SimVal.p hostname% CC SimVal.o SimValMain.cc -lpc hostname% a.out args = 111111
Function Return Values
Function return values match types in the same manner as with parameters.
They pass in much the same way.
Pascal 4.0 User’s Guide
The Pascal function,
RetReal.p
Simple Types
Simple types pass in a straightforward way, as in the following example:
7 function RetReal (r: real): real; begin
RetReal := r + 1 end;
The C++ main program,
RetRealMain.cc
#include <stdio.h> extern "C" double RetReal (double); int main(void)
{
double r, s;
r = 2.0;
s = RetReal (r);
printf (" %f \n", s);
}
The commands to compile and execute RetReal.p
and
RetRealMain.cc
hostname% pc -c RetReal.p hostname% CC RetReal.o RetRealMain.cc -lpc hostname% a.out
3.000000
The C++–Pascal Interface 153
154
7
The Pascal function,
RetShortReal.p
Type
shortreal
function RetShortReal (r: shortreal): shortreal; begin
RetShortReal := r + 1.0
end;
The C++ main program,
RetShortRealMain.cc
#include <stdio.h>
#include <math.h> extern "C" float RetShortReal (float); int main(void)
{
float r, s;
r = 2.0;
s = RetShortReal(r);
printf (" %8.6f \n", s);
}
The commands to compile and execute RetShortReal.p
and RetRealMain.cc
hostname% pc -c RetShortReal.p hostname% CC RetShortReal.o RetShortRealMain.cc -lpc hostname% a.out
3.000000
Input and Output
The Pascal function, IO.p
procedure IO; begin
writeln ('Hello, Pascal & St.Petersburg !'); end;
Pascal 4.0 User’s Guide
7
The C++ main program,
IOMain.cc
#include <stdio.h> extern "C" {
void IO ();
}; int main(void)
{
IO ();
printf ("Hello, C++ ! \n");
}
The commands to compile and execute IO.p
and IOMain.cc
hostname% pc -c IO.p hostname% CC IO.o IOMain.cc -lpc hostname% a.out
Hello, Pascal & St.Petersburg !
Hello, C++ !
Procedure Calls: Pascal–C++
A Pascal main program can also call C++ functions. The following examples show you how to pass simple types and arguments and include the commands that are used to compile and execute the final programs.
Arguments Passed by Reference
Pascal arguments can be passed by reference. Here we discuss how they work with C++.
The C++–Pascal Interface 155
7
Simple Types Passed by Reference
Simple types pass in a straightforward manner, as follows:
The C++ function, SimRef.cc
extern "C" void SimRef (
char &t,
char &f,
char &c,
int &i,
short &s,
float &r,
double &d)
{
t = 1;
f = 0;
c = 'z';
i = 9;
s = 9;
r = 9.9;
d = 9.9;
}
156 Pascal 4.0 User’s Guide
7
The Pascal main program,
SimRefMain.p
program SimRefMain (output); var
t, f: boolean;
c: char;
i: integer;
s: integer16;
r: shortreal;
d: real; procedure SimRef (
var t, f: boolean;
var c: char;
var i: integer;
var s: integer16;
var r: shortreal;
var d: real
); external C; begin
SimRef (t, f, c, i, s, r, d);
writeln (t, f: 6, c: 2, i: 2, s: 2, r: 4: 1, d: 4: 1); end.
The commands to compile and execute SimRef.cc
and
SimRefMain.p
hostname% CC -c SimRef.cc hostname% pc SimRef.o SimRefMain.p hostname% a.out true false z 9 9 9.9 9.9
Arguments Passed by Value
Pascal arguments can also be passed by value. Here is how they work with
C++.
The C++–Pascal Interface 157
7
Simple Types
Simple types match with value parameters. See the following example:
The C++ function, SimVal.cc
extern "C" void SimVal(
char t,
char f,
char c,
short si,
int i,
float sr,
double r,
int& Reply)
{
Reply = 0;
if (t) Reply += 01;
if (! f) Reply += 010;
if (c == 'z') Reply += 0100;
if (si == 9) Reply += 01000;
if (i == 9) Reply += 010000;
if (sr == (float)9.9) Reply += 0100000;
if (r == 9.9) Reply += 01000000;
}
158 Pascal 4.0 User’s Guide
7
The Pascal main program,
SimValMain.p
program SimValMain(output); var
t: boolean := true;
f: boolean := false;
c: char := 'z';
si:integer16:= 9;
i: integer := 9;
sr:shortreal:= 9.9;
r: real := 9.9;
args: integer; procedure SimVal(
t, f: boolean;
c: char;
si:integer16;
i: integer;
sr:shortreal;
r: real;
var Reply: integer); external C; begin
SimVal(t, f, c, si, i, sr, r, args);
writeln(' args = ', args :7 oct); end.
The commands to compile and execute SimVal.cc
and
SimValMain.p
hostname% CC -c SimVal.cc hostname% pc SimVal.o SimValMain.p hostname% a.out args = 111111
Function Return Values
Function return values match types in the same manner as with parameters.
They pass in much the same way.
The C++–Pascal Interface 159
7
The following example shows how to pass simple types:
The C++ function, RetReal.cc
extern "C" double RetReal (double &x)
{
return (x + 1.0);
}
The Pascal main program,
RetRealMain.p
program RetRealMain (output); var
r, s: real; function RetReal (var x: real): real; external C; begin
r := 2.0;
s := RetReal (r);
writeln ( r: 4: 1,' Return - ', s: 4: 1); end.
The commands to compile and execute RetReal.cc
and
RetRealMain.p
hostname% CC -c RetReal.cc hostname% pc RetReal.o RetRealMain.p hostname% a.out
2.0 Return - 3.0
160 Pascal 4.0 User’s Guide
7
Global Variables in C++ and Pascal
If the types are compatible, a global variable can be shared between C++ and
Pascal. See this example:
The Pascal procedure,
GloVar.p
var
Year: integer; procedure GloVar; begin
Year := 1995; end;
The C++ main program,
GloVarMain.cc
#include <stdio.h> extern "C" void GloVar (); int Year; int main(void)
{
Year = 2042;
GloVar ();
printf (" %d \n", Year);
}
The commands to compile and execute GloVar.p
and
GloVarMain.cc
hostname% pc -c GloVar.p hostname% CC GloVar.o GloVarMain.cc -lpc hostname% a.out
1995
The C++–Pascal Interface 161
7
Pascal File Pointers to C++
You can pass a file pointer from Pascal to C++, then have C++ do the I/O. See this example.
The C++ procedure,
UseFilePtr.cc
#include <stdio.h> extern "C" void UseFilePtr (FILE* ptr)
{
fprintf (ptr, "[1] \n");
fprintf (ptr, "[2] \n");
fprintf (ptr, "[3] \n");
}
The C++ main program,
UseFilePtrMain.p
program UseFilePtrMain (output); var
f: text;
cfile: univ_ptr; procedure UseFilePtr (cf: univ_ptr); external C; begin
rewrite (f, 'myfile.data');
cfile := getfile (f);
UseFilePtr (cfile); end.
The commands to compile and execute UseFilePtr.cc
and
UseFilePtrMain.p
hostname% CC -c UseFilePtr.cc hostname% pc UseFilePtr.o UseFilePtrMain.p hostname% a.out
[1]
[2]
[3]
162 Pascal 4.0 User’s Guide
The FORTRAN–Pascal Interface
8
This chapter describes how to mix FORTRAN 77 and Pascal modules in the same program. It contains the following sections:
Compiler Mixed-Language Programs
Compatibility of Types for FORTRAN and Pascal
General Parameter-Passing in FORTRAN and Pascal
Procedure Calls: FORTRAN-Pascal
Procedure Calls: Pascal-FORTRAN
Routines as Parameters page 163 page 164 page 167 page 168 page 185 page 202
Compiler Mixed-Language Programs
When you compile with the -v (verbose) option, the Pascal driver brings in the runtime libraries for the main module.
However, when you compile a module that is not the main module, and which is written in a language different from the main module, you must explicitly bring in the runtime library on the command-line.
For example, you must use the compiler options –lpfc and –lpc when you compile a FORTRAN main routine that calls Pascal. The –lpfc option links the common startup code for programs containing mixed Pascal and
FORTRAN object libraries. The –lpc option includes the Pascal object library, libpc .
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8
Specify –lpfc on the command-line before –lpc . For example: hostname% pc -c my_pascal.p hostname% f77 my_pascal.o my_fortran.f -lpfc -lpc
Sampmain.f:
MAIN:
The -c option to pc produces an unlinked object file.
When you compile a Pascal main routine that calls FORTRAN, you must use the compiler options –lpfc and –lF77 . The –lF77 option links the
FORTRAN object library, libf77 .
You must specify -lpfc on the command-line before -lF77 . For example: hostname% f77 -c my_fortran.f hostname% pc my_fortran.o my_pascal.p -lpfc -lF77 my_fortran.f:
MAIN:
You can omit the libraries if the foreign language module does not interact with the runtime environment, that is, it does no I/O, memory allocation, and so on. However, there is no overhead to linking to an unused library; therefore, always link in the appropriate runtime libraries, even if you think you may not need them.
Compatibility of Types for FORTRAN and Pascal
Table 8-1 lists the default sizes and alignments of compatible types for
FORTRAN and Pascal.
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Table 8-1 Default Sizes and Alignments of Compatible Types (Pascal and FORTRAN)
Pascal Type double longreal real single shortreal integer16 integer32 integer
-128..127
boolean alfa char string varying[n] of char array record
FORTRAN Type double precision double precision double precision real real integer*2 integer*4 integer*4 logical*1
, byte, or character logical*1
, byte, or character character*10 character character*80 structure /v / integer*4 character*n end structure array structure
Size (Bytes)
8
4
4
8
8
4
1
2
4
1
10
1
80
-
Same as element type
-
Alignment (Bytes)
8
8
8
4
4
2
4
4
1
1
1
1
1
4
4
Table 8-2 lists the default sizes and alignments of compatible types for
FORTRAN and Pascal with the xl option:
Table 8-2 Sizes and Alignments of Compatible Types (Pascal and FORTRAN) with –xl
Pascal Type real integer
FORTRAN Type real integer*2
Size (Bytes)
4
2
Alignment (Bytes)
4
2
Precautions with Compatible Types
This section describes the precautions you must take when working with character strings and array indexes.
The FORTRAN–Pascal Interface 165
166
8
Character Strings
There are some precautions to take with character strings regarding the null byte, passing by value, and static storage:
•
Set the byte count to zero before calling Pascal with a null varying string, because that is what Pascal assumes about such strings.
• Pass a structure consisting of a 4-byte integer and an array of characters from FORTRAN to a Pascal procedure, expecting a var parameter that is a variable-length string.
•
Pass by reference by making the strings var , in , out , or in out parameters.
• Set the string to constant because FORTRAN and Pascal each guarantees the null byte only if the string is a constant. Neither of them relies on the null byte, which is not required by the ISO Pascal Standard.
Array Indexes
The Pascal and FORTRAN array indexes can start at any integer; be sure they match.
Incompatibilities
There are several incompatibilities between Pascal and FORTRAN variant records, enumerated types, and set types.
Variant Records
In general, Pascal variant records require adjustment of alignment to match with FORTRAN unions and structures.
Enumerated Types
Pascal enumerated types have no comparable type in FORTRAN.
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Pascal Set Types
In Pascal, a set type is implemented as a bit vector, which is similar to a
FORTRAN 16-bit word. Direct access to individual elements of a set is highly machine-dependent and should be avoided.
Multidimensional Arrays
Pascal multidimension arrays are incompatible with FORTRAN multidimension arrays. Since Pascal arrays use row-major indexing, and FORTRAN arrays use column-major indexing, an array passed in either direction appears to be transposed.
General Parameter-Passing in FORTRAN and Pascal
A few general rules apply to passing parameters:
• By default, FORTRAN passes all parameters by reference.
• In FORTRAN, if you want to pass anything by value, then you must explicitly use the nonstandard function %VAL() .
• Pascal passes all parameters by value unless you explicitly state that they are var , out , or in out parameters, in which case they are passed by reference.
• The routine options nonpascal , extern fortran , and external fortran pass by reference.
The FORTRAN–Pascal Interface 167
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Procedure Calls: FORTRAN-Pascal
Here are examples of how a FORTRAN main program calls a Pascal procedure.
The Pascal procedure, Samp.p
.
Note the procedure definition.
The procedure name in the procedure statement is in lowercase with a trailing underscore (_). This format is required to match the conventions of the FORTRAN compiler.
var parameters are used to match
FORTRAN defaults.
procedure samp_(var i: integer; var r: real); begin
i := 9;
r := 9.9
end; { samp_ }
The FORTRAN main program,
Sampmain.f
. Note the procedure declaration and call.
FORTRAN converts to lowercase by default; you do not explicitly give the underscore (_).
integer i
double precision d
call Samp ( i, d )
write( *, '(I2, F4.1)') i, d
stop
end
The commands to compile and execute Samp.p
and
Sampmain.f
hostname% pc -c Samp.p hostname% f77 Samp.o Sampmain.f -lpfc -lpc
Sampmain.f:
MAIN: hostname% a.out
9 9.9
Variable Parameters
Pascal passes all var parameters by reference, FORTRAN’s default.
Simple Types without the
–xl
Option
With var parameters, simple types match.
168 Pascal 4.0 User’s Guide
The Pascal procedure,
SimVar.p
See the following example: procedure simvar_(var t, f: boolean; var c: char;
var i: integer; var r: real;
var si: integer16; var sr: shortreal); begin
t := true;
f := false;
c := 'z';
i := 9;
r := 9.9;
si := 9;
sr := 9.9
end; { simvar_ }
The FORTRAN main program,
SimVarmain.f
logical*1 t, f
character c
integer*4 i
double precision d
integer*2 si
real sr
call SimVar ( t, f, c, i, d, si, sr )
write(*, "(L2,L2,A2,I2,F4.1,I2,F4.1)")
& t, f, c, i, d, si,sr
stop
end
The commands to compile and execute SimVar.p
and
SimVarmain.f
hostname% pc -c SimVar.p hostname% f77 SimVar.o SimVarmain.f -lpfc -lpc
SimVarmain.f:
MAIN: hostname% a.out
T F z 9 9.9 9 9.9
8
The FORTRAN–Pascal Interface 169
170
8
The Pascal procedure,
StrVar.p
Simple Types with the
–xl
Option
When you pass the -xl option, the Pascal data type real must be paired with a FORTRAN data type real ; the Pascal data type integer must be paired with a FORTRAN data type, integer*2 .
Strings of Characters
The FORTRAN counterpart to the Pascal alfa and string types is a character string, and the FORTRAN counterpart to the Pascal varying is a structure. By default, FORTRAN, passes all by reference: type
varstr = varying [25] of char; procedure strvar_(var a: alfa; var s: string;
var v: varstr); begin
a := 'abcdefghij';
s := 'abcdefghijklmnopqrtstuvwxyz';
v := 'oyvay' end; { strvar_ }
The FORTRAN main program,
StrVarmain.f
structure /VarLenStr/
integer nbytes
character a*25
end structure
record /VarLenStr/ vls
character s10*10, s80*80, s25*25
vls.nbytes = 0
Call StrVar( s10, s80, vls )
s25(1:5) = vls.a(1:vls.nbytes)
write (*, 1) s10, s80, s25
1 format("s10='", A, "'",
& / "s80='", A, "'",
& / "s25='", A, "'" )
end
Pascal 4.0 User’s Guide
The commands to compile and execute StrVar.p
and
StrVarmain.f
hostname% pc -c StrVar.p hostname% f77 StrVar.o StrVarmain.f -lpfc -lpc
StrVarmain.f:
MAIN: hostname% a.out s10='abcdefghij' s80='abcdefghijklmnopqrtstuvwxyz s25='oyvay'
Fixed Arrays
For a fixed array parameter, pass the same type and size by reference, as shown in the following example:
The Pascal procedure,
FixVec.p
type
VecTyp = array [0..8] of integer; procedure fixvec_(var V: VecTyp; var Total: integer); var
i: integer; begin
Total := 0;
for i := 0 to 8 do
Total := Total + V[i] end; { fixvec_ }
The FORTRAN main program,
FixVecmain.f
integer Sum
integer a(9)
data a / 1,2,3,4,5,6,7,8,9 /
call FixVec ( a, Sum )
write( *, "( I3 )") Sum
stop
end
8
The FORTRAN–Pascal Interface 171
8
The commands to compile and execute FixVec.p
and
FixVecmain.f
hostname% pc -c FixVec.p hostname% f77 FixVec.o FixVecmain.f -lpfc -lpc hostname% a.out
FixVecmain.f:
MAIN:
45
The
univ
Arrays
You can pass any size array to a Pascal procedure expecting a univ array, but there is no advantage in doing so, since there is no type or size checking for separate compilations. However, if you want to use an existing Pascal procedure that has a univ array, you can do so. All univ arrays that are in , out , in out, or var parameters pass by reference.
The Pascal procedure,
UniVec.p
, which defines a 10element array type
VecTyp = array [0..9] of integer; procedure univec_(in V:univ VecTyp; var Last: integer;
var Total: integer); var
i: integer; begin
Total := 0;
for i := 0 to Last do
Total := Total + V[i] end; { univec_ }
The FORTRAN main program,
UniVecmain.f
, which passes a 3-element array to the Pascal procedure written to do a 10element array
integer Sum
integer a(0:2)
data a / 7, 8, 9 /
call UniVec ( a, 2, Sum )
write( *, "( I3 )") Sum
stop
end
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The commands to compile and execute UniVec.p
and
UniVecmain.f
hostname% pc -c UniVec.p
hostname% f77 UniVec.o UniVecmain.f -lpfc -lpc
UniVecmain.f:
MAIN: hostname% a.out
24
Conformant Arrays
For conformant arrays, with single-dimension array, pass upper and lower bounds, placed after the declared parameter list, as in: function ip(var x:array[lb..ub:integer] of real):real;
...
double precision v1(10) double precision z z = ip ( v1, %VAL(0), %VAL(9) )
...
Pascal passes the bounds by value, so FORTRAN must pass them by value, too.
One bounds pair may apply to several arrays if they are declared in the same parameter group: function ip(var x,y:array[lb..ub:integer] of real):real;
...
double precision v1(10), v2(10) double precision z z = ip ( v1, v2, %VAL(0), %VAL(9) )
...
Examples of single-dimension array and array of character conformant arrays follow. Conformant arrays are included here only because they are a relatively standard feature; there are usually more efficient and simpler ways to do that.
The FORTRAN–Pascal Interface 173
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8
The Pascal procedure,
IntCA.p
. Pascal passes the bounds by value.
Example 1: Single-Dimension Array procedure intca_(var a: array [lb..ub: integer] of integer); begin
a[1] := 1;
a[2] := 2 end; { intca_ }
The FORTRAN main program,
IntCAmain.f
integer k
integer s(0:2)
data s / 0, 0, 0 /
call IntCA ( s, %VAL(0), %VAL(2) )
do k = 0, 2
write( *, "(I1)" ) s(k)
end do
stop
end
The commands to compile and execute IntCA.p
and
IntCAmain.f
hostname% pc -c IntCA.p hostname% f77 IntCA.o IntCAmain.f -lpfc -lpc
IntCAmain.f:
0
1
MAIN: hostname% a.out
2
Example 2: Array of Characters
The Pascal procedure,
ChrCA.p
. Pascal passes the bounds by value.
procedure chrca_(var a: array [lb..ub: integer] of char); begin
a[0] := 'T';
a[13] := 'o' end; { chrca_ }
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The FORTRAN main program,
ChrCAmain.f
character s*16
data s / "this is a string" /
call ChrCA( s, %VAL(0), %VAL(15) )
write( *, "(A)" ) s
stop
end
The commands to compile and execute ChrCA.p
and
CharCAmain.f
hostname% pc -c ChrCA.p hostname% f77 ChrCA.o ChrCAmain.f -lpfc -lpc
ChrCAmain.f:
MAIN: hostname% a.out
This is a string
Records and Structures
In most cases, a Pascal record describes the same objects as its FORTRAN structure equivalent, provided that the components have compatible types and are declared in the same order. The compatibility of the types depends mostly on size and alignment.
For more information, see “Compatibility of Types for FORTRAN and Pascal” on page 164.
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8
The Pascal procedure,
StruChr.p
A Pascal record of an integer and a character string matches a FORTRAN structure of the same. Consider these examples: type
lenstr =
record
nbytes: integer;
chrstr: array [0..25] of char
end; procedure struchr_(var v: lenstr); begin
v.chrstr := 'oyvay';
v.nbytes := 5 end; { struchr_ }
The FORTRAN main program,
StruChrmain.f
structure /VarLenStr/
integer nbytes
character a*25
end structure
record /VarLenStr/ vls
character s25*25
vls.nbytes = 0
Call StruChr( vls )
s25(1:5) = vls.a(1:vls.nbytes)
write ( *, 1 ) s25
1 format("s25='", A, "'" )
stop
end
The commands to compile and execute Struchr.p
and
StruChrmain.f
hostname% pc -c StruChr.p hostname% f77 StruChr.o StruChrmain.f -lpfc -lpc
StruChrmain.f:
MAIN: hostname% a.out s25='oyvay'
Pascal 4.0 User’s Guide
The Pascal procedure,
VarRec.p
8
Variant Records
FORTRAN equivalents of variant records can sometimes be constructed, although there is some variation with architecture, and sometimes you need to adjust the alignment.
type vr = record
case tag: char of
'a': ( ch1, ch2: char ) ;
'b': ( flag: boolean ) ;
'K': ( ALIGN: integer ) ;
end ; procedure varrec_ ( var Rec: vr ) ; begin
if ( Rec.ch1 = 'a' )
then Rec.ch2 := 'Z' end; { VarRec.p }
The FORTRAN–Pascal Interface 177
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8
The FORTRAN main program,
VarRecmain.f
. The variable
ALIGN is integer*2 , and is needed to match the Pascal variant record layout.
structure /a_var/
character ch1, ch2
end structure
structure /b_var/
character flag
end structure
structure /c_var/
integer*2 ALIGN
end structure
structure /var_part/
union
map
record /a_var/ a_rec
end map
map
record /b_var/ b_rec
end map
map
record /c_var/ c_rec
end map
end union
end structure
structure /vrnt/
character tag
record /var_part/ var_rec
end structure
record /vrnt/ VRec
VRec.var_rec.a_rec.ch1 = 'a'
VRec.var_rec.a_rec.ch2 = 'b'
call varrec ( VRec )
write ( *, * ) VRec.var_rec.a_rec.ch2
stop
end
The commands to compile and execute VarRec.p
and
VarRecmain.f
without –xl hostname% pc -c VarRec.p hostname% f77 VarRec.o VarRecmain.f
VarRecmain.f:
MAIN: hostname% a.out b
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Pascal Set Type
The Pascal set type is incompatible with FORTRAN.
Pascal
intset
Type
The Pascal intset type is predefined as set of [0..127] . A variable of this type takes a minimum of 16 bytes of storage.
The Pascal procedure,
IntSetVar.p
, which has an intset of the elements
[1 , 3 , 7 , 8] procedure intsetvar_(var s: intset); begin
s := [1, 3, 7, 8] end; { intsetvar_ }
The FORTRAN main program,
IntSetVarmain.f
integer*2 s(8)
pointer ( ps, s )
ps = malloc(16)
call IntSetVar ( s )
do i = 5, 8
write( *, 1 ) s(i), i
end do
1 format(o3,1x, 'octal (word', i2, ')')
write( *, "('110 001 010 (binary, word 8)')")
write( *, "('876 543 210 (bit nos, word 8)')")
stop
The FORTRAN–Pascal Interface 179
8
The commands to compile and execute IntSetVar.p
and
IntSetVarmain.f
. The output of this example depends on the architecture of your machine.
hostname% pc -c IntSetVar.p hostname% f77 IntSetVar.o IntSetVarmain.f -lpfc -lpc
IntSetVarmain.f:
MAIN: hostname% a.out
0 octal
0 octal
0 octal
612 octal
110 001 010
876 543 210
(word 5)
(word 6)
(word 7)
(word 8)
(binary, word 8)
(bit nos, word 8)
Value Parameters
In general, Pascal passes value parameters on the stack.
Simple Types without the
–xl
Option
Without the -xl option, simple types match.
180 Pascal 4.0 User’s Guide
See the following example:
The Pascal procedure,
SimVal.p
.
t , f , c , i , r , and s are value parameters.
procedure simval_(t, f: boolean; c: char; i: integer;
r: real; s: integer16; var reply: integer); begin
reply := 0;
{ If nth arg is ok, set nth octal digit to one. }
if t then
reply := reply + 1;
if not f then
reply := reply + 8;
if c = 'z' then
reply := reply + 64;
if i = 9 then
reply := reply + 512;
if r = 9.9 then
reply := reply + 4096;
if s = 9 then
reply := reply + 32768 end; { simval_ }
8
The FORTRAN main program,
SimValmain.f
logical*1
character
integer*4 i
double precision d t, f c
integer*2
integer*4 s args
data t / .true. /, f / .false. /, c / 'z' /
& i / 9 /, d / 9.9 /, s / 9 /
call SimVal( %VAL(t), %VAL(f), %VAL(c),
& %VAL(i), %VAL(d), %VAL(s), args )
write( *, 1 ) args
1 format('args=', o6, '(If nth digit=1, arg n OK)')
stop
end
The FORTRAN–Pascal Interface 181
182
8
The commands to compile and execute SimVal.p
and
SimValmain.f
hostname% pc -c SimVal.p hostname% f77 SimVal.o SimValmain.f -lpfc -lpc
SimValmain.f:
MAIN: hostname% a.out args=111111(If nth digit=1, arg n OK)
Simple Types with the
–xl
Option
With the -xl option, match Pascal real with FORTRAN real and Pascal integer with FORTRAN integer*2 .
You can pass by value using the %VAL() feature of FORTRAN.
Type
shortreal
Unlike C, there is no problem with passing shortreal value parameters between Pascal and FORTRAN. They can be passed exactly as in the previous example, with the Pascal shortreal type matching the FORTRAN real type.
Arrays
Since FORTRAN cannot pass arrays by value, it cannot pass strings of characters, fixed arrays, or univ arrays by value.
Conformant Arrays
Although Pascal generally passes all value parameters on the stack, the exception is value-conformant array parameters, which are handled by creating a copy in the caller environment and passing a pointer to the copy. In addition, the bounds of the array must be passed. See “Conformant Arrays” on page 173.
This example is the same as the one in the earlier section, except that the var prefix is deleted.
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8
Pascal procedure, ChrCAx.p
procedure chrca_ ( a: array [lb..ub:integer] of char) ; begin
a[0] := 'T' ;
a[13] := 'o' ; end; { chrca_ }
The FORTRAN main program,
ChrCAmain.f
character s*16
data s / "this is a string" /
call ChrCA( s, %VAL(0), %VAL(15) )
write( *, "(A)" ) s
stop
end
The commands to compile and execute ChrCAx.p
and
ChrCAmain.f
hostname% pc -c ChrCAx.p hostname% f77 ChrCAx.o ChrCAmain.f -lpfc -lpc
ChrCAmain.f:
MAIN: hostname% a.out
This is a string
Pointers
Pointers are easy to pass, as shown in the following example:
The Pascal procedure,
PassPtr.p
. In the Pascal procedure statement, the name must be all in lowercase, with a trailing underscore (_).
type
PtrInt = ^integer ;
PtrReal = ^real ; procedure passptr_ ( var iPtr: PtrInt ;
var dPtr: PtrReal ) ; begin
iPtr^ := 9 ;
dPtr^ := 9.9 ; end ;
The FORTRAN–Pascal Interface 183
8
The FORTRAN main program,
PassPtrmain.f
. In the
FORTRAN main program, the name is converted to lowercase.
Uppsercase is ignored.
program PassPtrmain
integer i
double precision d
integer iptr, dptr
pointer ( iPtr, i ), ( dPtr, d )
iPtr = malloc( 4 )
dPtr = malloc( 8 )
i = 0
d = 0.0
call PassPtr ( iPtr, dPtr )
write( *, "(i2, f4.1)" ) i, d
stop
end
The commands to compile and execute PastPtr.p
and
PassPtrmain.f
hostname% pc -c PassPtr.p hostname% f77 PassPtr.o PassPtrmain.f -lpfc -lpc
PassPtrmain.f:
MAIN passptrmain: hostname% a.out
9 9.9
Function Return Values
Function return values match types the same as with parameters, and they pass in much the same way. See “Procedure Calls: FORTRAN-Pascal” on page 168.
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The Pascal function,
RetReal.p
Simple Types
The simple types pass in a straightforward way, as follows: function retreal_(var x: real): real; begin
retreal_ := x + 1 end; { retreal_ }
The FORTRAN main program,
RetRealmain.f
double precision r, s, RetReal
r = 2.0
s = RetReal( r )
write( *, "(2f4.1)") r, s
stop
end
The commands to compile and execute RetReal.p
and
RetRealmain.f
without – xl hostname% pc -c RetReal.p hostname% f77 RetReal.o RetRealmain.f -lpfc -lpc
RetRealmain.f:
MAIN: hostname% a.out
2.0 3.0
Type
shortreal
There is no problem with returning a shortreal function value between
Pascal and FORTRAN. As in the previous example, it can be passed exactly, with the Pascal shortreal type matching the FORTRAN real type (without
-xl ).
Procedure Calls: Pascal-FORTRAN
This section parallels “Procedure Calls: FORTRAN-Pascal” on page 168. The comments and restrictions given in that section apply here, also.
The FORTRAN–Pascal Interface 185
8
Variable Parameters
Pascal passes all var parameters by reference, the FORTRAN default.
Simple Types
Simple types pass in a straightforward manner, as follows:
The FORTRAN subroutine,
SimVar.f
subroutine SimVar ( t, f, c, i, d, si, sr )
logical*1 t, f
character c
integer i
double precision d
integer*2 si
real sr
t = .true.
f = .false.
c = 'z'
i = 9
d = 9.9
si = 9
sr = 9.9
return
end
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The Pascal main program,
SimVarmain.p
program SimVarmain(output); var
t, f: boolean;
c: char;
i: integer;
r: real;
si: integer16;
sr: shortreal; procedure simvar(var t, f: boolean; var c: char;
var i: integer; var r: real;
var si: integer16; var sr: shortreal);
external fortran; begin
simvar(t, f, c, i, r, si, sr);
writeln(t, f: 6, c: 2, i: 2, r: 4: 1, si: 2, sr: 4: 1) end. { SimVarmain }
The commands to compile and execute SimVar.p
and
SimVarmain.p
hostname% f77 -c SimVar.f
SimVar.f: simvar: hostname% pc SimVar.o SimVarmain.p -lpfc -lF77 hostname% a.out true false z 9 9.9 9 9.9
Strings of Characters
The alfa and string types pass simply; varying strings are a little tricky. All pass by reference.
The FORTRAN–Pascal Interface 187
188
8
The FORTRAN subroutine,
StrVar.f
subroutine StrVar ( s10, s80, vls )
character s10*10, s80*80
structure /VarLenStr/
integer nbytes
character a*25
end structure
record /VarLenStr/ vls
character ax*10, sx*80, vx*5
data ax / "abcdefghij" /,
& sx / "abcdefghijklmnopqrstuvwxyz" /,
& vx / "oyvay" /
s10(1:10) = ax(1:10)
s80(1:80) = sx(1:80)
vls.a(1:5) = vx(1:5)
vls.nbytes = 5
return
end
The Pascal main program,
StrVarmain.p
program StrVarmain(output); type
varstr = varying [25] of char; var
a: alfa;
s: string;
v: varstr; procedure strvar(var xa: alfa; var xs: string;
var xv: varstr); external fortran; begin
strvar(a, s, v);
writeln(a);
writeln(s);
writeln(v);
writeln('length(v)= ', length(v): 2) end. { StrVarmain }
Pascal 4.0 User’s Guide
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The commands to compile and execute StrVar.f
and
StrVarmain.p
hostname% f77 -c StrVar.f
StrVar.f: strvar: hostname% pc StrVar.o StrVarmain.p -lpfc -lF77 hostname% a.out abcdefghij abcdefghijklmnopqrstuvwxyz oyvay length(v)= 5
Character Dummy Arguments
When you call FORTRAN 77 routines with character dummy arguments from
Pascal programs—that is, routines in which string arguments are specified as character*(*) in the FORTRAN source, there is no explicit analogue in
Pascal.
So, if you try to simply pass an actual string and specify the FORTRAN routine as extern fortran , the program fails, because implementation of this type of arguments implies that the actual length of the string is implicitly passed as an extra value argument after the string pointer.
To specify this routine in Pascal, declare it as having two arguments: a VAR argument of string type for the string pointer, and an extra value argument of integer32 type for the string length.
It is incorrect to specify the routine as extern fortran because Pascal passes all arguments to FORTRAN routines by reference. Consequently, to pass this type of argument, you must:
• Declare two arguments as described above, specifying the routine as simply external (without the fortran directive)
•
Add a trailing underscore to the routine name in a Pascal program
The FORTRAN–Pascal Interface 189
8
The following example illustrates this method:
The Pascal program, sun.pas
program Test(input,output); var
s : string; procedure mygrout_(var prompt :string; length :integer32); external; begin
writeln('Starting...');
s := 'Trio Jeepy';
mygrout_(s, 8);
writeln('Ending...') end.
The FORTRAN subroutine, mygrout.f
subroutine MyGrout(N)
character*(*)N
write(6,*) N
return
end
The commands to compile and run this program hostname% pc -g -c sun.pas hostname% f77 -g sun.o mygrout.f -lpc mygrout.f:
mygrout: hostname% a.out
Starting...
Trio Jee
Ending...
190 Pascal 4.0 User’s Guide
The FORTRAN subroutine,
FixVec.f
Fixed Arrays
For a fixed-array parameter, pass the same type and size by reference:
subroutine FixVec ( V, Sum )
integer Sum
integer V(0:8)
integer i
Sum = 0
do 2 i = 0, 8
2 Sum = Sum + V(i)
return
end
8
The Pascal main program,
FixVecmain.p
program FixVecmain(output); type
VecTyp = array [0..8] of integer; var
V: VecTyp := [1, 2, 3, 4, 5, 6, 7, 8, 9];
Sum: integer; procedure fixvec(var XV: VecTyp; var XSum: integer);
external fortran; begin
fixvec(V, Sum);
writeln(Sum: 4) end. { FixVecmain }
The commands to compile and execute FixVec.f
and
FixVecmain.p
hostname% f77 -c FixVec.f
FixVec.f: fixvec: hostname% pc FixVec.o FixVecmain.p -lpfc -lF77 hostname% a.out
45
The FORTRAN–Pascal Interface 191
192
8
The FORTRAN subroutine,
UniVec.f
The
univ
Arrays
The univ arrays that are in , out , in out , or var parameters pass by reference.
subroutine UniVec ( V, Last, Sum )
integer V(0:2), Last, Sum, i
Sum = 0
do i = 0, Last
Sum = Sum + V(i)
end do
return
end
The Pascal main program,
UniVecmain.p
program UniVec; type
VecTyp = array [0..9] of integer; procedure univec(var V:univ VecTyp; in Last: integer;
var Sum: integer); external fortran; var
Sum: integer;
V: array [0..2] of integer; begin
V[0] := 7;
V[1] := 8;
V[2] := 9;
univec(V, 2, Sum);
writeln(Sum) end. { UniVec }
Pascal 4.0 User’s Guide
The commands to compile and execute UniVec.f
and
UniVecmain.p
hostname% f77 -c UniVec.f
UniVec.f: univec: hostname% pc UniVec.o UniVecmain.p -lpfc -lF77 hostname% a.out
24
Conformant Arrays
Pascal-conformant array parameters are not compatible if Pascal calls
FORTRAN.
8
The FORTRAN–Pascal Interface 193
194
8
The FORTRAN subroutine,
StruChr.f
Records and Structures
Records and structures pass as follows:
subroutine StruChr ( vls )
structure /VarLenStr/
integer nbytes
character a*25
end structure
record /VarLenStr/ vls
vls.a(1:5) = 'oyvay'
vls.nbytes = 5
return
end
The Pascal main program,
StruChrmain.p
program StruChrmain; type
lenstr =
record
nbytes: integer;
chrstr: array [0..25] of char
end; var
v: lenstr; procedure struchr(var v: lenstr);
external fortran; begin
struchr(v);
writeln('v.chrstr = "', v.chrstr, '"');
writeln('v.nbytes =', v.nbytes: 2) end. { StruChrmain }
Pascal 4.0 User’s Guide
8
The commands to compile and execute StruChr.f
and
StruChrmain.p
hostname% f77 -c StruChr.f
StruChr.f:
struchr: hostname% pc StruChr.o StruChrmain.p -lpfc -lF77 hostname% a.out v.chrstr = "oyvay" v.nbytes = 5
Variant Records
You can construct FORTRAN equivalents of variant records. There is some variation with architecture, and sometimes you need to adjust the alignment.
The FORTRAN–Pascal Interface 195
8
Chapter 6, “The C–Pascal Interface,” has an example that matches the following example.
The FORTRAN subroutine,
VarRec.f
. The variable ALIGN is integer*2 and is needed to match the Pascal variant record layout.
subroutine VarRec ( VRec )
structure /a_var/
character ch1, ch2
end structure
structure /b_var/
character flag
end structure
structure /c_var/
integer*2 ALIGN
end structure
structure /var_part/
union
map
record /a_var/ a_rec
end map
map
record /b_var/ b_rec
end map
map
record /c_var/ c_rec
end map
end union
end structure
structure /vrnt/
character tag
record /var_part/ var_rec
end structure
record /vrnt/ VRec
if ( VRec.var_rec.a_rec.ch1 .eq. 'a' )
& VRec.var_rec.a_rec.ch2 = 'Z'
return
end
196 Pascal 4.0 User’s Guide
8
The Pascal main program,
VarRecmain.p
program VarRecmain; type
vr =
record
case tag: char of
'a': ( ch1, ch2: char );
'b': ( flag: boolean );
'K': ( ALIGN: integer )
end; var
Rec: vr; procedure varrec(var d: vr); external fortran; begin
Rec.tag := 'a';
Rec.ch1 := 'a';
Rec.ch2 := 'b';
varrec(Rec);
writeln(Rec.ch2) end. { VarRecmain }
The commands to compile and execute VarRec.f
and
VarRecmain.p
without –xl hostname% f77 -c VarRec.f
VarRec.f: varrec: hostname% pc VarRec.o VarRecmain.p -lpfc -lF77 hostname% a.out b
Value Parameters
With external fortran on the procedure statement, Pascal passes value parameters as FORTRAN expects them.
The FORTRAN–Pascal Interface 197
8
The FORTRAN subroutine,
SimVal.f
Simple Types
With external fortran , the procedure name in the procedure statement and in the call must be in lowercase, with no underscore ( _ ).
subroutine SimVal( t, f, c, i, d, s, reply )
logical*1 t, f
character c
integer*4 i
double precision d
integer*2 s
integer*4 reply
reply = 0
if ( t ) reply = reply + 1
if ( .not. f ) reply = reply + 8
if ( c .eq. 'z' ) reply = reply + 64
if ( i .eq. 9 ) reply = reply + 512
if ( d .eq. 9.9 ) reply = reply + 4096
if ( s .eq. 9 ) reply = reply + 32768
return
end
198 Pascal 4.0 User’s Guide
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The Pascal main program,
SimValmain.p
program SimVal(output); var
t: boolean := true;
f: boolean := false;
c: char := 'z';
i: integer := 9;
r: real := 9.9;
s: integer16 := 9;
args: integer; procedure simval(t, f: boolean; c: char; i: integer;
r: real; s: integer16; var reply: integer);
external fortran; begin
simval(t, f, c, i, r, s, args); writeln('args=', args: 6 oct, ' (If nth digit=1, arg n OK.)') end. { SimVal }
The commands to compile and execute SimVal.f
and
SimValmain.p
hostname% f77 -c SimVal.f
SimVal.f:
simval: hostname% pc SimVal.o SimValmain.p -lpfc -lF77 hostname% a.out args=111111 (If nth digit=1, arg n OK.)
The FORTRAN–Pascal Interface 199
200
8
Pointers
Pointers are easy to pass, as shown in the following example:
The FORTRAN subroutine,
PassPtr.f
. In the FORTRAN subroutine, the name is converted to lowercase.
Uppsercase is ignored.
subroutine PassPtr ( iPtr, dPtr )
integer i
double precision d
pointer ( iPtr, i ), ( dPtr, d )
i = 9
d = 9.9
return
end
The Pascal main program,
PassPtrmain.p
. In the
Pascal program, where it calls the FORTRAN subroutine, the name must be in lowercase.
program PassPtrmain; type
PtrInt = ^ integer;
PtrReal = ^ real; var
i: integer := 0;
r: real := 0.0;
iP: PtrInt;
rP: PtrReal; procedure passptr(var xiP: PtrInt; var xrP: PtrReal);
external fortran; begin
iP := addr(i);
rP := addr(r);
passptr(iP, rP);
writeln(i: 2, r: 4: 1) end. { PassPtrmain }
Pascal 4.0 User’s Guide
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The commands to compile and execute PassPtr.f
and
PassPtrmain.p
hostname% f77 -c PassPtr.f
PassPtr.f:
passptr: hostname% pc PassPtr.o PassPtrmain.p -lpfc -lF77 hostname% a.out
9 9.9
Function Return Values
Function return values match types the same as with parameters, and they pass in much the same way.
Simple Types
The simple types pass in a straightforward way, as in this example:
The FORTRAN function,
RetReal.f
double precision function retreal ( x )
retreal = x + 1.0
return
end
The Pascal main program,
RetRealmain.p
program retrealmain; var
r, s: real; function retreal(x: real): real; external fortran; begin
r := 2.0;
s := retreal(r);
writeln(r: 4: 1, s: 4: 1) end. { retrealmain }
The FORTRAN–Pascal Interface 201
8
The commands to compile and execute RetReal.f
and
RetRealmain.p
hostname% f77 -c RetReal.f
RetReal.f
retreal: hostname% pc RetReal.o RetRealmain.p -lpfc -lF77 hostname% a.out
2.0 3.0
Type
shortreal
You can return a shortreal function value between Pascal and FORTRAN.
Pass it exactly as in the previous example, with the Pascal shortreal type matching the FORTRAN real type (without -xl ).
Routines as Parameters
If the passed procedure is a top-level procedure, write it as follows:
The FORTRAN subroutine,
PassProc.f
subroutine PassProc ( r, s, prcdr )
real r, s
external prcdr
call prcdr ( r, s )
return end
202 Pascal 4.0 User’s Guide
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The Pascal main program,
PassProcmain.p
program PassProcmain; var
a, b: real; procedure passproc(var u: real; var v: real;
procedure p(var r: real; var s: real));
external fortran; procedure AddOne(var x: real; var y: real); begin
y := x + 1 end; { AddOne } begin
a := 8.0;
b := 0.0;
passproc(a, b, AddOne);
writeln(a: 4: 1, b: 4: 1) end. { PassProcmain }
The commands to compile and execute PassProc.f
and
PassProcmain.p
hostname% f77 -c PassProc.f
PassProc.f
passproc hostname% pc PassProc.o PassProcmain.p -lpfc -lF77 hostname% a.out
8.0 9.0
If the procedure is not a top-level procedure, then you do not deal with how to pass it, because that requires allowing for the static link. A procedure or function passed as an argument is associated with a static link to its lexical parent’s activation record.
When an outer block procedure or function is passed as an argument, Pascal passes a null pointer in the position normally occupied by the static link of the passed routine. So that procedures and functions can be passed to other languages as arguments, the static links for all procedure or function arguments are placed after the end of the conformant array bounds pairs, if any.
The FORTRAN–Pascal Interface 203
8
Routines in other languages can be passed to Pascal; a dummy argument must be passed in the position normally occupied by the static link of the passed routine. If the passed routine is not a Pascal routine, the argument is used only as a placeholder.
204 Pascal 4.0 User’s Guide
Error Diagnostics
9
This chapter discusses the errors you may come across while writing software programs with Pascal. It contains the following sections:
Compiler Syntax Errors
Compiler Semantic Errors
Compiler Panics, I/O Errors
Runtime Errors page 205 page 210 page 217 page 217
Note – Appendix B, “Error Messages,” lists in numerical order all the error messages generated by Pascal.
Compiler Syntax Errors
Here are some common syntax errors in Pascal programs and the ways that the compiler handles them.
Illegal Characters
Characters such as @ are not part of Pascal. If they are found in the source program and are not part of a string constant, a character constant, or a comment, they are considered to be illegal characters. This error can happen if you leave off a closing string quotation mark ( ' ).
205
9
206
Most nonprinting characters in your input are also illegal, except in character constants and character strings. Except for the tab and formfeed characters, which are used to format the program, nonprinting characters in the input file print as the character ?
in your listing.
String Errors
Encountering an end-of-line after an opening string quotation mark ( ' ) without first encountering the matching closing quote yields the diagnostic:
Unmatched ' for string.
Also, anything enclosed in double quotes (for example, "hello" ) is treated as a comment and is, therefore, ignored.
Programs containing # characters (other than in column 1 or in arbitrary-based integers) can produce this diagnostic, because early implementations of Pascal use # as a string delimiter. In this version, # is used for #include and preprocessor directives, and must be in column 1.
Digits in Real Numbers
Pascal requires digits in real numbers before the decimal point. Thus, the statements b := .075; and c := 05e-10; generate the following diagnostics in Pascal:
Mon Feb 13 10:46:44 1995 digerr.p:
5 b:= .075; e 18740-------------------^--- Digits required before decimal point
6 c:= .05e-10 e 18740-------------------^--- Digits required before decimal point
These constructs are also illegal as data input to variables in read statements whose arguments are variables of type real , single , shortreal , double , and longreal .
Pascal 4.0 User’s Guide
9
Replacements, Insertions, and Deletions
When Pascal encounters a syntax error in the input text, the compiler invokes an error recovery procedure. This procedure examines the input text immediately after the point of error and uses a set of simple corrections to determine whether or not to allow the analysis to continue. These corrections involve replacing an input token with a different token or inserting a token.
Most of these changes do not cause fatal syntax errors.
The exception is the insertion of or replacement with a symbol, such as an identifier or a number; in these cases, the recovery makes no attempt to determine which identifier or what number should be inserted. Thus, these are considered fatal syntax errors.
The Pascal program, synerr.p
, which uses ** as an exponentiation operator program synerr_example(output); var i, j are integer; begin
for j :* 1 to 20 begin
write(j);
i = 2 ** j;
writeln(i))
end end. { synerr_example } synerr.p
produces a fatal syntax error when you compile it because Pascal does not have an exponentiation operator.
hostname% pc synerr.p
Mon Feb 13 10:56:19 1995 synerr.p:
3 var i, j are integer; e 18460----------------^--- Replaced identifier with a ':'
6 for j :* 1 to 20 begin
E 18490-----------------^--- Expected keyword (null)
E 18460-----------------^--- Replaced ':' with a identifier e 18480----------------------------^--- Inserted keyword do
8 i = 2 ** j; e 18480---------------^--- Inserted keyword if
E 18480----------------------^--- Inserted identifier e 18480-------------------------^--- Inserted keyword then
9 writeln(i)) e 18450-------------------------^--- Deleted ')'
Error Diagnostics 207
208
9
Undefined or Improper Identifiers
If an identifier is encountered in the input but is undeclared, the error recovery mechanism replaces it with an identifier of the appropriate class.
Further references to this identifier are summarized at the end of the containing procedure, function, or at the end of the program. This is the case if the reference occurs in the main program.
Similarly, if you use an identifier in an inappropriate way, for example, if a type identifier is used in an assignment statement, pc produces a diagnostic and inserts an identifier of the appropriate class. Further incorrect references to this identifier are flagged only if they involve incorrect use in a different way.
pc summarizes all incorrect uses in the same way it summarizes uses of undeclared variables.
Expected Symbols and Malformed Constructs
If none of the corrections mentioned previously appears reasonable, the error recovery routine examines the input to the left of the point of error to see if there is only one symbol that can follow this input. If so, the recovery prints a diagnostic which indicates that the given symbol is expected.
In cases where none of these corrections resolve the problems in the input, the recovery may issue a diagnostic that indicates “malformed” input. If necessary, pc can then skip forward in the input to a place where analysis can continue. This process may cause some errors in the missed text to be skipped.
See this example:
The Pascal program, synerr2.p
. Here output is misspelled, and a is given a
FORTRAN-style variable declaration.
program synerr2_example(input,outpu); integer a(10) begin
read(b);
for c := 1 to 10 do
a(c) := b * c end. { synerr2_example }
Pascal 4.0 User’s Guide
9
These are the error messages you receive when you compile synerr2.p
. On line 6, parentheses are used for subscripting (as in FORTRAN), rather than the square brackets that are used in Pascal.
The compiler noted that a was not defined as a procedure
(delimited by parentheses in
Pascal). Since you cannot assign values to procedure calls, pc diagnosed a malformed statement at the point of assignment.
hostname% pc synerr2.p
Mon Feb 13 11:02:04 1995 synerr2.p:
3 integer a(10) e 18480-------^--- Inserted '['
E 18490-----------------^--- Expected identifier
6 read(b);
E 18420----------------^--- Undefined variable
7 for c := 1 to 10 do
E 18420---------------^--- Undefined variable
8 a(c) := b * c
E 18420---------------^--- Undefined procedure
E 15010 line 1 - File output listed in program statement but not declared
In program synerr2_example:
E 18240 a undefined on line 8
E 18240 b undefined on lines 6 8
E 18240 c undefined on lines 7 8
Expected and Unexpected End-of-file
If pc finds a complete program, but there is more (noncomment) text in the input file, then it indicates that an end-of-file is expected. This situation may occur after a bracketing error, or if too many end s are present in the input. The message may appear after the recovery says that it Expected '.' because a period ( .
) is the symbol that terminates a program.
If severe errors in the input prohibit further processing, pc may produce a diagnostic message followed by QUIT . Examples include unterminated comments and lines longer than 1,024 characters.
The Pascal program, mism.p
program mismatch_example(output); begin
writeln('***');
{ The next line is the last line in the file. }
writeln
Error Diagnostics 209
9
When you compile mism.p
, the end-of-file is reached before an end delimiter hostname% pc mism.p
E 26020-------^--- Malformed declaration
15130-------^--- Unexpected end-of-file - QUIT
Compiler Semantic Errors
The following sections explain the typical formats and terminology used in
Pascal error messages.
Format of the Error Diagnostics
In the example program above, the error diagnostics from the Pascal compiler include the line number in the text of the program, as well as the text of the error message. While this number is most often the line where the error occurred, it can refer to the line number containing a bracketing keyword like end or until . If so, the diagnostic may refer to the previous statement. This diagnostic occurs because of the method the compiler uses for sampling line numbers. The absence of a trailing semicolon ( ; ) in the previous statement causes the line number corresponding to the end or until to become associated with the statement.
As Pascal is a free-format language, the line number associations can only be approximate and may seem arbitrary in some cases.
Incompatible Types
Since Pascal is a strongly-typed language, many type errors can occur, which are called type clashes by the compiler.
The Pascal compiler distinguishes among the following type classes in its diagnostics: array boolean char file integer pointer real record scalar string varying
210 Pascal 4.0 User’s Guide
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Thus, if you try to assign an integer value to a char variable, you receive a diagnostic as follows:
Mon Feb 13 13:16:20 1995 inchar.p:
E 25190 line 6 - Type clash: integer is incompatible with char
... 25560: Type of expression clashed with type of variable in assignment
In this case, one error produces a two-line error message. If the same error occurs more than once, the same explanatory diagnostic is given each time.
The scalar Class
The only class whose meaning is not self-explanatory is scalar . It has a precise meaning in the Pascal standard where it refers to char , integer , and boolean types as well as the enumerated types. For the purposes of the
Pascal compiler, scalar in an error message refers to a user-defined enumerated type, such as color in: type color = (red, green, blue)
For integers, the more precise denotation integer is used.
Procedure and Function Type Errors
For built-in procedures and functions, two kinds of errors may occur. If a routine is called with the wrong number of arguments, a message similar to the following is displayed:
Mon Feb 13 13:21:26 1995 sin.p:
E 10010 line 6 - Builtin function SIN takes exactly 1 argument
If the type of an argument is wrong, you receive a message similar to the following:
Mon Feb 13 13:31:14 1995 abs.p:
E 10180 line 8 - Argument to ABS must be of type integer or real, not char
Error Diagnostics 211
9
Scalar Error Messages
Error messages stating that scalar (user-defined) types cannot be read from and written to files are often difficult to interpret. In fact, if you define: type color = (red, green, blue) standard Pascal does not associate these constants with the strings red , green , and blue in any way. Pascal adds an extension so that enumerated types can be read and written; however, if the program is to be portable, you must write your own routines to perform these functions.
Standard Pascal only allows the reading of characters, integers, and real numbers from text files, including input (not strings or boolean s). You can make the following declaration: file of color
However, the representation is binary rather than as strings, and it is impossible to define input as other than a text file.
Expression Diagnostics
The diagnostics for semantically ill-formed expressions are explicit, as the following program shows. This program, expr.p
, is admittedly far-fetched, but illustrates that the error messages are clear enough so you can easily determine the problem in the expressions.
212 Pascal 4.0 User’s Guide
program expr_example(output); var
a: set of char;
b: Boolean;
c: (red, green, blue);
p: ^ integer;
A: alfa;
B: packed array [1..5] of char; begin
b := true;
c := red;
new(p);
a := [];
A := 'Hello, yellow';
b := a and b;
a := a * 3;
if input < 2 then writeln('boo');
if p <= 2 then writeln('sure nuff');
if A = B then writeln('same');
if c = true then writeln('hue''s and color''s') end. { expr_example }
This program generates the following error messages: hostname% pc expr.p
Mon Feb 13 13:36:51 1995 expr.p:
E 13050 line 16 - Constant string too long
E 20070 line 17 - Left operand of and must be Boolean, not set
E 25550 line 18 - expression has invalid type
E 20030 line 18 - Cannot mix sets with integers and reals as operands of *
E 20240 line 19 - files may not participate in comparisons
E 20230 line 20 - pointers and integers cannot be compared - operator was <=
E 20220 line 21 - Strings not same length in = comparison
E 20230 line 22 - scalars and Booleans cannot be compared - operator was =
9
Error Diagnostics 213
9
Type Equivalence
The Pascal compiler produces several diagnostics that generate the following message: non-equivalent types
In general, Pascal considers types to be the same only if they derive from the same type identifier. Therefore, the following two variables have different types, even though the types look the same and have the same characteristics.
x : record a: integer; b: char; end; y : record a: integer; b: char; end;
The assignment: x := y produces the following diagnostic messages:
Mon Feb 13 14:22:46 1995 inchar.p:
E 25170 line 12 - Type clash: non-identical record types
... 25560: Type of expression clashed with type of variable in assignment
214 Pascal 4.0 User’s Guide
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To make the assignment statement work, you must declare a type and use it to declare the variables, as follows: type r = record a: integer; b: char; end; var x: r; y: r;
Alternatively, you could use the declaration: x, y : record a: integer; b: char; end;
The assignment statement then works.
Unreachable Statements
Pascal flags unreachable statements. Such statements usually correspond to errors in the program logic, as shown in the following example:
The Pascal program, unreached.p
program unreached_example(output); label
1; begin
goto 1;
writeln('Unreachable.');
1:
writeln('Reached this.'); end. { unreached_example }
Error Diagnostics 215
9
This error message is generated when you compile unreached.p
.
hostname% pc unreached.p
Tue Feb 14 14:21:03 1995 unreached.p: w 18630 line 8 - Unreachable statement
A statement is considered to be reachable if there is a potential path of control, even if it cannot be taken. Thus, no diagnostic is produced for the statement: if false then writeln('Impossible!')
The goto Statement
Pascal detects and produces an error message about goto statements that transfer control into structured statements—for example, for and while . It does not allow such jumps, nor does it allow branching from the then part of an if statement into the else part. Such checks are made only within the body of a single procedure or function.
Uninitialized Variables
Pascal does not necessarily set variables to an initial value unless you explicitly request that with the –Z option. The exception is static variables, which are guaranteed to be initialized with zero values.
Because variable use is not tracked across separate compilation units, pc does nothing about uninitialized or unused variables in global scope, that is, in the main program. However, pc checks variables with local scope—those declared in procedures and functions, to make sure they are initialized before being used.
pc flags uninitialized variables with a warning message.
Unused Variables, Constants, Types, Labels, and Routines
If you declare a variable, constant, type, procedure, or function in local scope but never use it, Pascal gives you a warning message. It does not do this for items declared in global scope because you can use the items in a separately compiled unit.
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Compiler Panics, I/O Errors
One class of error that rarely occurs, but which causes termination of all processing when it does, is a panic.
A panic indicates a compiler-detected internal inconsistency. A typical panic message follows: pc0 internal error line=110 yyline=109
If you receive such a message, compilation is terminated. Save a copy of your program, then contact Sun Customer Support. If you were making changes to an existing program when the problem occurred, you may be able to work around the problem by determining which change caused the internal error and making a different change or error correction to your program.
The only other error that aborts compilation when no source errors are detected is running out of memory. Most tables in Pascal, with the exception of the parse stack, are dynamically allocated, and can grow to take up a good deal of process space. In general, you can get around this problem with large programs by using the separate compilation facility. See Chapter 5, “Separate
Compilation,” for details.
If you receive an out of space message during translation of a large procedure or function, or one containing a large number of string constants, either break the procedure or function into smaller pieces or increase the maximum data segment size using the limit command of csh (1).
Runtime Errors
If you declare a label but never use it, Pascal gives you a warning. This is true even for a label declared in global scope.
When Pascal detects an error in a program during runtime, it prints an error message and aborts the program, producing a core image.
Following is a list of runtime errors that Pascal generates:
< filename > : Attempt to read from a file open for writing
< filename > : Attempt to write to a file open for reading
Error Diagnostics 217
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218
< filename > : Bad data found on enumerated read
< filename > : Bad data found on integer read
< filename > : Bad data found on real read
< filename > : Bad data found on string read
< filename > : Bad data found on varying of char read
< filename > : Cannot close file
< filename > : Could not create file
< filename > : Could not open file
< filename > : Could not remove file
< filename > : Could not reset file
< filename > : Could not seek file
< filename > : Could not write to file
< filename > : File name too long (maximum of < number > exceeded
< filename > : File table overflow (maximum of < number > exceeded)
< filename > : Line limit exceeded
< filename > : Non-positive format widths are non-standard
< filename > : Overflow on integer read
< filename > : Tried to read past end of file
< filename > : eoln is undefined when eof is true
Argument < number > is out of the domain of atan
Pascal 4.0 User’s Guide
9
Argument to argv of < number > is out of range
Assertion #< number > failed: < assertion message >
Cannot close null file
Cannot compute cos(< number >)
Cannot compute sin(< number >)
Cannot open null file
Enumerated type value of < number > is out of range on output
Floating point division by zero
Floating point operand is signaling Not-A-Number
Floating point overflow
Floating point underflow
Illegal argument of < number > to trunc
Inexact floating point result
Integer divide by zero
Integer overflow
Internal error in enumerated type read
Invalid floating point operand
Label of < number > not found in case
Negative argument of < number > to sqrt
Non-positive argument of < number > to ln
Overflow/Subrange/Array Subscript Error
Error Diagnostics 219
9
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Pointer value (< number >) out of legal range
Ran out of memory
Range lower bound of < number > out of set bounds
Range upper bound of < number > out of set bounds
Reference to an inactive file
Second operand to MOD (< number >) must be greater than zero
Statement count limit of < number > exceeded
Subrange or array subscript is out of range
Sun FPA not enabled
Unknown SIGFPE code
Unordered floating point comparison
Value of < number > out of set bounds
Varying length string index < number > is out of range exp(< number >) yields a result that is out of the range of reals i = < number >: Bad i to pack(a,i,z) i = < number >: Bad i to unpack(z,a,i) pack(a,i,z): z has < number > more elements than a substring outside of bounds of string unpack(z,a,i): z has < number > more elements than a
Pascal 4.0 User’s Guide
Overview
The XView Toolkit
10
This chapter introduces the XView programmer’s toolkit, a part of the XView application programmer’s interface (API). It assumes you are familiar with
XView windows as a user, and introduces XView from a programmer’s point of view. For details, see the XView Programming Manual by Dan Heller,
O’Reilly & Associates, Inc., 1990.
The sections in this chapter are:
Overview
Pascal Interface
Conversion of C to Pascal
Sample Program page 221 page 223 page 227 page 230
Note – Support for the XView toolkit will not be provided in future releases of
Pascal.
The XView API is an object-oriented, server-based, user-interface toolkit for the
X Window System Version 11 (X11). It is designed and documented to help programmers manipulate XView windows and other XView objects. This chapter focuses on using it with Pascal.
221
10
222
Tools
This kit is a collection of functions. The runtime system is based on each application having access to a server-based Notifier, which distributes input to the appropriate window, and a Window Manager, which manages overlapping windows. There is also a Selection Service for exchanging data between windows (in the same or different processes).
Objects
XView is an object-oriented system. XView applications create and manipulate
XView objects that are associated with XView packages. Objects in the same package share common properties. The major objects are windows, icons, cursors, menus, scrollbars, and frames. A frame contains non-overlapping subwindows within its borders. You manipulate an object by passing a unique identifier or handle for that object to procedures associated with that object.
Object-Oriented Programming
Traditional programs are made up of procedures. When you need to operate on some data, you pass the data to a procedure. This style of programming can be referred to as procedure-oriented programming.
In object-oriented programming, the data are organized into objects, which are similar to records in that an object can contain data fields of different types. In addition to data, though, objects also have associated procedures, called methods. The methods of an object generally perform all operations that can be performed on the data of the object. When you need to operate on the data in an object, you direct the object to do the operation. This is referred to as sending a message to the object, and is similar to calling a procedure.
Each object is an instance of a given class. A class is much like a type in that it defines a kind of object. Creating an instance of a given class is much like declaring a variable of a given type, since creating an instance of a class creates an object that has the properties and characteristics defined for its class.
Classes are different from types in that a class can inherit data fields and methods from another class. In fact, you always define a new class by declaring it a subclass of some class. The new class is called a child or descendant class; the old class is called a superclass, parent, or ancestor class.
A descendant can itself have descendants. Thus, classes form a tree structure,
Pascal 4.0 User’s Guide
Pascal Interface
10 with the root being the class from which all others are descended. In the
XView toolkit, the root is the class Generic Object, which has no data fields and no methods. Each descendant of Generic Object is specialized in some way, perhaps with additional data fields or methods.
What gives object orientation its power is that the inherited methods of a subclass can be reimplemented so that they take actions suited to the subclass.
For example, consider a system that has three classes: Drawable Object,
Window, and Icon. Window and Icon are subclasses of Drawable Object. This setup creates the hierarchical relationship illustrated in Figure 10-1.
Drawabl e
Object
Window Icon
Figure 10-1 A Sample Class Hierarchy
Suppose that Drawable Object has a method that draws the object. Window and Icon inherit that method, but each implements it in a different way.
Window defines a Draw method that draws windows; Icon defines a Draw method that draws icons.
When you write your program, you can send a message to an object directing it to draw itself without knowing whether, at runtime, the object is an icon or a window. This method works because both Window and Icon are descendants of Drawable Object. At runtime, the object that receives the method draws itself using its class implementation of the Draw method.
To write XView applications in Pascal, you use special libraries, modules files, object handles, and standard procedures.
The XView Toolkit 223
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224
Compiling with Libraries
Most XView procedures you call are in the libraries pxview , xview , and X11 .
To compile an XView program, link the libraries, in order. For example: hostname% pc my_pascal.p -lpxview -lxview -lolgx -lX11
Header Files
The header files define the necessary data types, constants, and external procedures necessary to write programs using the XView interface with Pascal.
Names
The names of the header file are the same as the XView C language header files with the .h
extension changed to _p.h
. For example, the Pascal header file corresponding to the XView file panel.h
is named panel_p.h
. Other header files are canvas_p.h, text_p.h
, and so on.
In addition to the header files corresponding to the XView headers, there is an another one, stddefs_p.h
.
This file defines some basic types that are used by most of the other Pascal
XView header files, and is included by the header files that need it.
Usage
To use header files with Pascal, put in include lines for any other header files you need.
Attribute Procedures
Each class of objects has its own set of attributes. Each attribute has a predefined (default) value. For example, for the class of scrollbars, there is a width and a color.
The standard C interface to XView defines two routines, xv_get() and xv_set() , which get and set attributes of XView objects. These routines take an arbitrary number and type of parameters and return various types, depending on its arguments.
Pascal 4.0 User’s Guide
10
Instead of these routines, the Pascal interface to XView defines a separate routine to get and set each attribute.
• set —The routine to set an attribute is called set_ attrname. Each set routine is a procedure, and takes as its first argument the object for which the attribute is being set. The second argument is the value of the attribute.
• get —The routine to get the value of an attribute is called get_ attrname.
Each get routine is a function, and takes an XView object as the first argument. It returns the value of the attribute requested.
For example: set_WIN_SHOW ( frame, true ); width := get_CANVAS_WIDTH ( canvas );
These routines are defined in the header file, attrgetset_p.h
.
Attribute Lists
Some of the XView C routines can optionally take extra arguments that are lists of attributes and values. The extra arguments vary in number and type. You must pass a 0 to the last argument of these routines.
Since Pascal does not support variable length argument lists, the Pascal definition has a single argument.
Instead, special versions of these routines are provided which take as a last argument an argument of type Attr_avlist . This type is a pointer to an array of attributes and values. The special routines are: xv_init_l() , xv_create_l() , xv_find_l() , selection_ask_l() , selection_init_request_l() .
The XView Toolkit 225
226
10
Example calls are:
Here, mymenu is an object of type XV_object.
mymenu := xv_create (NULL, MENU, 0); ncols := get_MENU_NCOLS (mymenu); set_MENU_NITEMS (mymenu, items);
xv_find_l (mymenu, MENU, attr_create_list_2s (MENU_DEFAULT,4)); xv_destroy (mymenu);
The lists for Attr_avlist are created by functions that have the following names: attr_create_list_ n () attr_create_list_ ns ()
• The n indicates the number of arguments the routine accepts.
•
The number of arguments can be 1-16.
• The routines ending in s return a pointer to a static attribute-value array, which is reused with each call to the static list routines.
• The versions without the s return a dynamically allocated list, which should be passed to xv_destroy() when you are finished with it.
Handles
When you create an XView object, xv_create() returns a handle for that object. You pass this handle to the appropriate procedure for manipulating the object.
Data Types
Each XView object has its own specific data type. The name of an object’s data type always starts with a capital letter. For example, the data type for a scrollbar is Scrollbar . The standard list of these types is in the header files.
Pascal 4.0 User’s Guide
10
Coding Fragment
Here is an example that illustrates the style of programming with the XView interface in Pascal. This program:
• Creates a vertical scrollbar with a view length of 100 pixels
•
Changes the view length to 200 pixels
• Destroys the scrollbar var bar, pi: Scrollbar; begin bar := xv_create ( 0, SCROLLBAR, 0 ); pi := xv_create_l ( 0, SCROLLBAR,
attr_create_list_4s ( SCROLLBAR_VIEW_LENGTH, 100,
SCROLLBAR_DIRECTION, SCROLLBAR_VERTICAL)); set_SCROLLBAR_VIEW_LENGTH( bar, 200 ); xv_destroy ( bar );
In this example:
• bar is declared to be of type Scrollbar .
• xv_create() and xv_create_l() are invoked as functions.
• set SCROLLBAR_VIEW_LENGTH () is invoked as a procedure.
• xv_destroy() is invoked as a procedure.
Conversion of C to Pascal
Here is an example of a problem that you may encounter when converting C to
Pascal. It recommends some changes that you can make to work around the problem.
An Example
The Problem —Besides the six standard generic procedures, there are approximately 80 other procedures, plus hundreds of attributes. These are all documented in the XView Programming Manual. The problem is that all of the coding is in C.
The XView Toolkit 227
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228
The Straightforward Part —You can use the following items of information as you find them in the manual, with no change:
• The XView procedure names
•
The XView object names
• The XView object data types (except Boolean , see the following section)
The More Complex Parts —You must make the following changes:
•
Any elementary C data type used must be converted to the corresponding
Pascal data type.
•
Any C procedure that returns something must be invoked in Pascal as a function; otherwise, it must be invoked as a procedure.
• The XView type Boolean must be converted to the Pascal type, boolean .
Table 10-1 shows you how to convert C declarations to Pascal.
Table 10-1 C Declarations to Pascal Declarations int short
C unsigned
Pascal integer , subrange, or numeric constant unsigned , subrange, or numeric constant
1 integer16 , subrange, or numeric constant unsigned short unsigned16 , subrange, or nonnegative numeric constant char char (or single-letter string literal for special definition modules) float double shortreal , longreal , or real constant (always passed as LONGREAL ) real or real constant any pointer type pointer type any enum type unsigned type any struct type record type of corresponding size and layout char * array of char or string literal other array types array type of corresponding size
1. Defined in stddefs_p.h
Pascal 4.0 User’s Guide
10
Sample Translation of an XView Function to Pascal
In the section, “Summary of Procedures and Macros,” in the XView
Programming Manual, is the following entry: texsw_insert()
Inserts characters in buf into textsw at the current insertion point. The number of characters actually inserted is returned. This will equal buf_len unless there was a memory allocation failure. If there was a failure, it will return 0.
Textsw_index textsw_insert(textsw, buf, buf_len)
Textsw textsw; char int
*buf; buf_len;
If you translate the entry to Pascal, it means:
•
Leave the object data type, Textsw , as is.
• Since the function returns the number of characters inserted, invoke it as an integer function.
...
var textsw: Textsw ; buf: array[0..3] of char ; buf_len: integer;
N:Textsw_index; begin
...
N := textsw_insert (textsw, buf, buf_len) ; end.
The XView Toolkit 229
10
Sample Program
The following program, xview.p
, makes a window: program hello(output);
#include "stddefs_p.h"
#include "attrgetset_p.h" var
base_frame :Frame;
base_panel :Panel;
message :Xv_panel_or_item_ptr;
text :string; begin
text :=
'
Hello, World!
'
;
xv_init(0);
base_frame := xv_create(nil, FRAME, 0);
base_panel := xv_create(base_frame, PANEL, 0);
message := xv_create(panel, PANEL_MESSAGE, 0);
set_PANEL_LABEL_STRING(message, text);
window_main_loop(base_frame); end. {hello}
To compile xview.p
and link in the necessary libraries, use the following command-line. Replace local_library_path with the path for the Pascal XView libraries on your system.
hostname% pc -I local_library_path xview.p -L$OPENWINHOME/lib \
-lpxview -lxview -lolgx -lX11
Now run the executable file: hostname% a.out
Soon after you run the executable file, the window opens as a single frame, with the string Hello, World!
in the frame header.
230 Pascal 4.0 User’s Guide
10
Menu Demo Program
Here is a more complicated program, menu_demo.p
, that makes a window and a panel with a menu button. The choices displayed are: Option 1, Option2, and Option 3.
program MenuDemo(output);
#include "stddefs_p.h"
#include "attrgetset_p.h" var
base_frame : Frame;
base_panel : Panel;
button : Panel_button_item;
menu : Menu;
frame_label : string;
button_label : string;
option1 : Cstringp;
option2 : Cstringp;
option3 : Cstringp; procedure menu_proc(menu_: Menu; menu_item: Menu_item); var
menu_string : Cstringp; begin
menu_string := get_MENU_STRING(menu_item);
set_FRAME_RIGHT_FOOTER(base_frame, menu_string^); end; begin
frame_label := 'FRAME LABEL';
button_label := 'BUTTON LABEL';
new(option1); option1^ := 'OPTION 1';
new(option2); option2^ := 'OPTION 2';
new(option3); option3^ := 'OPTION 3';
xv_init(0);
The XView Toolkit 231
10
base_frame := xv_create(nil, FRAME, 0);
set_FRAME_LABEL(base_frame, frame_label);
set_FRAME_SHOW_FOOTER(base_frame, TRUE);
base_panel := xv_create(base_frame, PANEL, 0);
menu := xv_create(nil, MENU, 0);
set_MENU_STRINGS_3(menu, option1, option2, option3);
set_MENU_NOTIFY_PROC(menu, addr(menu_proc));
button := xv_create(base_panel, PANEL_BUTTON, 0);
set_PANEL_LABEL_WIDTH(button, 200);
set_PANEL_LABEL_STRING(button, button_label);
set_PANEL_ITEM_MENU(button, menu);
window_main_loop(base_frame); end. {menu_demo}
To compile menu_demo.p
and link in the necessary libraries, use the following command-line: hostname% pc menu_demo.p -Ipascal_xview_include_path \
-Lpascal_xview_include_path -lpxview -lxview -lolgx -lX11
Now run the executable file: hostname% a.out
232 Pascal 4.0 User’s Guide
Math Libraries
11
This chapter describes how to use the libm and libsunmath functions in
Pascal programs. The math libraries are always accessible from a Pascal program because the Pascal compiler driver pc calls ld , the linker and loader, with the -lsunmath -lm options. If you compile Pascal program with the -v option, it prints the command-line used to call each of the compilation passes.
For convenience, Pascal supports special Pascal header files, math_p.h
and sunmath_p.h
, which contain prototypes of math functions, procedures, and some useful constants. The math_p.h
file refers to sunmath_p.h
by an
#include directive.
This chapter contains the following sections:
Contents of the Math Libraries libm Functions
IEEE Support Functions
SPARC Libraries
Arithmetic Exceptions
Math Library Exception-Handling Function: matherr() libsunmath Support for IEEE Modes and Exceptions page 234 page 235 page 236 page 238 page 239 page 240 page 242
233
11
Contents of the Math Libraries
Altogether, there are three math libraries:
• libm.a
—A set of functions required by the various standards to which the operating system conforms
• libm.so
—(Solaris 2.x only) The shared version of libm.a
• libsunmath.a
—A set of functions not required by the standards, but are of common use
Table 11-1 lists the contents of the math libraries.
Table 11-1 Contents of Math Libraries
Algebraic functions
Roots m+
Euclidean distance m+, s
Transcendental functions
Elementary transcendental functions
Trigonometric functions
Trigonometric functions of radian arguments m+
Trigonometric functions of degree arguments s
Trigonometric functions (scaled in Pi) s
Trigonometric functions (with double precision Pi) s
Hyperbolic functions m+
Exponential, logarithm, power m+, s
Financial functions s
Higher transcendental functions
Bessel m+
Gamma m+
Error function m+
Integral rounding functions m+, s
234 Pascal 4.0 User’s Guide
libm Functions
11
Table 11-1 Contents of Math Libraries (Continued)
Random number generators
Additive pseudo-random generators s
Linear pseudo-random generators s
Random number shufflers s
IEEE support functions
IEEE functions m+
IEEE test m+
IEEE values s
IEEE sun s
Control flags s
Floating-point trap handling
IEEE handling s
Handling for specific SIGFPE codes (in libc )
Error handling function m
Data conversion s
BSD miscellaneous s
Base conversion routines (in libc )
FORTRAN intrinsic functions s s
Legend : m Functions available in bundled libm m+
Functions available in bundled libm and as single-precision version only in libsunmath
Functions available in unbundled libm ( libsunmath )
Most numerical functions are available in double- and single-precision version.
In general, the names of the single-precision version are formed by adding f to the names of the double-precision version.
Math Libraries 235
11
The following Pascal program is an example of how to use math functions.
program TestLibm(output);
#include <math_p.h> var
d0,d1,d2: double;
f0,f1,f2: single; begin
d0 := 0.0; d1 := 1.0; d2 := 2.0;
f0 := 0.0; f1 := 1.0; f2 := 2.0;
writeln('Trigonometric functions');
writeln(sin(d0));
writeln(sinf(f0));
sincos(M_PI_2, d1, d2);
writeln(d1, d2);
sincosf(M_PI_2, f1, f2);
writeln(f1, f2);
writeln('Exponential, logarithm, power');
writeln(exp(d1));
writeln(log(d1));
writeln(pow(d1, d1));
writeln(expf(f1));
writeln(logf(f1));
writeln(powf(f1, f1)); end.
IEEE Support Functions
This section describes the IEEE support functions, including ieee_functions() , ieee_values() , and ieeee_retrospective() .
236 Pascal 4.0 User’s Guide
11
ieee_functions()
The functions described in ieee_functions (3M) provide capabilities either required by the IEEE standard or recommended in its appendix. Example: program TestIEEEFunctions(output);
#include "math_p.h" var
d1: double := 1.0;
d2: double := 2.0;
i1: integer := 1; begin
writeln('IEEE functions');
writeln(ilogb(d1));
writeln(isnan(d1));
writeln(copysign(d1, d2));
writeln(fabs(d1));
writeln(fmod(d1, d1));
writeln(nextafter(d1, d1));
writeln(remainder(d1, d1));
writeln(scalbn(d1, i1)); end.
ieee_values()
IEEE values, such as infinity, NaN, minimum and maximum positive floatingpoint numbers, are provided by special functions described in the ieee_values (3M) man page. Another example follows.
Math Libraries 237
11 program TestIEEEValues(output);
#include "math_p.h" var
l0: integer32 := 0; begin
writeln('IEEE values');
writeln(infinity);
writeln(signaling_nan(l0));
writeln(quiet_nan(l0));
writeln(max_normal);
writeln(max_subnormal);
writeln(min_normal);
writeln(min_subnormal); end.
ieee_retrospective()
The libm function ieee_retrospective() prints to stderr information about unrequited exceptions and nonstandard IEEE modes. Pascal programs call ieee_retrospective() on exit by default.
SPARC Libraries
The libm and libsunmath libraries also contain:
• Argument reduction functions, using infinitely precise Pi and trigonometric functions scaled in Pi
•
Data conversion routines for converting floating-point data between IEEE and non-IEEE formats
•
Random number generators
There are two facilities for generating uniform pseudo-random numbers, addrans (3M) and lcrans (3M).
addrans is an additive random number generator; lcrans is a linear congruential random number generator. In addition, shufrans (3M) shuffles a set of pseudo-random numbers to provide even more randomness for applications that need it.
238 Pascal 4.0 User’s Guide
11 program TestRandom(output);
#include "math_p.h" var
n: integer := 100;
i: integer;
ilb, { Lower bound }
iub: integer; { Upper bound }
ia: array [1..100] of integer; begin
writeln('Integer linear congruential random number generator');
ilb := I_LCRAN_LB;
iub := I_LCRAN_UB;
i_lcrans_(ia, n, ilb, iub);
for i := 1 to n do
writeln(ia[i]);
writeln('Integer additive random number generator');
ilb := minint;
iub := maxint;
i_addrans_(ia, n, ilb, iub);
for i := 1 to n do
writeln(ia[i]);
writeln('Integer random number shufflers');
i_shufrans_(ia, n, ilb, iub);
for i := 1 to n do
writeln(ia[i]); end.
Arithmetic Exceptions
An arithmetic exception arises when an attempted atomic arithmetic operation does not produce an acceptable result. The meaning of the terms “atomic” and
“acceptable” may vary, depending on the context.
Following are the five types of IEEE floating-point exceptions:
•
Invalid operation —An operand is invalid for the operation about to be performed.
Math Libraries 239
11
• Division by zero —The divisor is zero, and the dividend is a finite non-zero number; or, more generally, an exact infinite result is delivered by an operation on finite operands.
•
Overflow —The correctly rounded result is larger than the largest number in the required precision.
• Underflow —The number is too small, or precision is lost, and no signal handler is established for underflow.
• Inexact —The rounded result of a valid operation is different from the infinitely precise result. This exception occurs whenever there is untrapped overflow or untrapped underflow.
Math Library Exception-Handling Function: matherr()
Some libm functions are specified to call matherr() when an exception is detected. You can redefine matherr() by including a function named matherr() in the program. When an exception occurs, a pointer to the exception structure, exc , is passed to the user-supplied matherr() function.
This structure, defined in the math_p.h
header file, is as follows: type
exception = record
kind: integer;
name: ^string;
arg1: double;
arg2: double;
retval: double;
end;
The element kind is an integer constant that describes the type of exception that occurred, and is one of the following constants. These constants are defined in the header file.
240 Pascal 4.0 User’s Guide
11
DOMAIN
SING
OVERFLOW
UNDERFLOW
TLOSS
PLOSS
Argument domain exception
Argument singularity
Overflow range exception
Underflow range exception
Total loss of significance
Partial loss of significance
If your matherr() function returns a non-zero result, no exception message is printed, and errno is not set.
program TestMatherr(output);
#include <math_p.h> function matherr(var info: exception): integer; begin
case info.kind of
DOMAIN: begin
{ change sqrt to return sqrt(-arg1), not NaN }
if substr(info.name^, 1, length('sqrt')) = 'sqrt' then begin
info.retval := sqrt(-info.arg1);
matherr := 1; { No exception message will be printed }
end;
end;
otherwise
matherr := 0;
end; end; begin
writeln('Error handling function');
writeln('sqrt(-1)= ', sqrt(-1)); end.
Math Libraries 241
11
libsunmath Support for IEEE Modes and Exceptions
ieee_handler() is used primarily to establish a signal handler for a particular floating-point exception or group of exceptions.
The syntax of this function is described in the ieee_handler (3M) man page.
This following Pascal program demonstrates how to abort on division by zero.
program TestIEEEHandler(output);
#include <math_p.h> procedure DivisionHandler(
sig: integer;
sip: univ_ptr;
uap: univ_ptr); begin
writeln('Bad data - division by zero.'); end; { DivisionHandler } var
FpAction, FpException: string;
Zero: integer := 0; begin
FpAction := 'set';
FpException := 'division';
writeln(ieee_handler(FpAction, FpException,
addr(DivisionHandler)));
writeln('1/0 = ', 1 / Zero);
writeln(ieee_handler(FpAction, FpException, SIGFPE_DEFAULT));
writeln('1/0 = ', 1 / Zero); end.
ieee_flags() is the recommended interface to:
• Query or set rounding direction mode
•
Query or set rounding precision mode
• Examine, clear, or set accrued exception flags
242 Pascal 4.0 User’s Guide
11
The syntax of this function is described in the ieee_flags (3M) man page.
If an exception is raised at any time during program execution, then its flag is set, unless it is explicitly cleared. Clearing accrued exceptions is done by a call, as shown in the following Pascal program.
program TestIEEEFlags(output);
#include "math_p.h" var
FlAction, FlMode, FlIn: string;
FlOut: string_pointer;
Zero: integer := 0; begin
writeln(sqr(-1)); { Invalid operation }
writeln(1 / Zero); { Division by zero }
writeln(exp(709.8)); { Overflow }
writeln(exp(-708.5)); { Underflow }
writeln(log(1.1)); { Inexact }
FlAction := 'clear';
FlMode := 'exception';
FlIn := 'all';
writeln(ieee_flags(FlAction, FlMode, FlIn, FlOut)); end.
Math Libraries 243
11
244 Pascal 4.0 User’s Guide
Pascal Preprocessor
This appendix describes the preprocessors, cpp (1) and cppas .
A
cpp cppas
cpp (1) is the C language preprocessor. Pascal runs your source program through cpp (1) when you compile it without the –xl option. For a complete description of cpp (1), see the Solaris documentation.
The cppas preprocessor handles the Pascal conditional variables and compiler directives. You call cppas using the –xl option.
Conditional Variables
A conditional variable is defined when it appears in a %var directive; otherwise, it is undefined. In addition, we predefine:
__sun
__sparc
__unix
__SVR4
__SUNPRO_PC=0x400 sun sparc unix
These variables are not predefined when you use -s0 , -s1 , -V0 , or -V1 .
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A defined conditional variable is enabled ( true ) when it appears in either the
%enable directive or in the –config option; otherwise, it is disabled ( false ), as in:
%var one two
%enable two
The following section describes %var and %enable . Programs that contain conditional variables must be compiled with the –xl option.
Compiler Directives
A directive indicates some action for the compiler to take. You can use a directive anywhere in your program.
Each directive consists of a percent sign ( % ) followed by the directive name.
Programs that contain compiler directives must be compiled with the –xl option.
Table A-1 summarizes the compiler directives.
Table A-1 cppas Compiler Directives
Compiler
Directive
%config
%debug
%else
%elseif
Description
Sets a special predefined conditional variable with a value of either true or false .
Instructs pc to compile this line of code when you use the -cond compiler directive.
If expression in %if expression %then is false , the compiler skips over the %then part and executes the %else part instead.
If expression in %if expression %then is false , the compiler skips over the %then part and executes the %elseif part instead. Similar to
%els e.
%elseifdef If expression in %ifdef expression %then is false, the compiler skips over the %then part and executes the %elseifdef part instead.
%enable Sets a conditional variable to true .
%endif
%error
Indicates the end of an %if or %ifdef directive.
Prints a string on the standard output and treats it as an error.
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Table A-1 cppas Compiler Directives (Continued)
Compiler
Directive
%exit
Description
Stops processing the current Pascal source file.
%if
%ifdef
When the compiler encounters a %if expression %then directive, it evaluates expression. If expression is true , pc executes the statements after %then . If expression is false , pc skips over %then .
Determines whether or not you previously defined a conditional variable in a %var directive.
%include Inserts the lines from the specified file into the input stream.
%list
%nolist
Enables a listing of the program.
Disables the program listing.
%slibrary Inserts the lines from the specified file into the input stream. Same as
%include .
%var Defines conditional variables.
%warning Prints a warning string on the standard output.
The rest of this appendix contains detailed descriptions and examples of each directive.
The
%config
Directive
The %config directive is a predefined conditional variable with a value of either true or false .
Syntax
%config
Comments
%config is true when you compile your program with the -config option; otherwise, %config is false .
Use %config in an %if , %ifdef , %elseif , or %elseifdef directive to catch any undefined values specified with -config . Do not define %config in the
%var directive.
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The Pascal program, config.p
, which defines the conditional variables one and two
Example program config_example(output);
{ This program demonstrates the use of the
%config compiler directive. } var
a: integer := maxint;
b: integer := minint;
%var one two begin
writeln('Begin program.');
%if one %then
writeln('One is defined as ', a:2, '.');
%elseif two %then
writeln('Two is defined as ', b:2, '.');
%elseif %config %then
writeln('Nothing is defined.');
%endif
writeln('End program.') end. { config_example }
The output when you compile config.p
without the
-config option hostname% pc -xl config.p hostname% a.out
Begin program.
End program.
The output when you define the variable one hostname% pc -xl -config one config.p hostname% a.out
Begin program.
One is defined as 32767.
End program.
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The output when you define two hostname% pc -xl -config two config.p hostname% a.out
Begin program.
Two is defined as -32768.
End program.
The output when you define foo hostname% pc -xl -config foo config.p
Fri Mar 3 15:22 1995 config.p
Error: –CONFIG command argument foo was never declared.
Compilation failed
The
%debug
Directive
The %debug directive instructs pc to compile this line of code when you use the –cond compiler directive.
Syntax
%debug;
Comments
The %debug directive works in conjunction with the –cond compiler option.
–cond causes pc to compile the lines in your program that begin with
%debug . Without –cond , pc treats lines with %debug as comments.
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Example
The Pascal program, debug.p
program debug_example(output);
{ This program demonstrates the use of the
%debug compiler directive. } begin
writeln ('Hello, how are you?');
%debug; writeln ('Fine, thank you.'); end. { debug example }
The output when you compile debug.p
without the –cond option hostname% pc -xl debug.p hostname% a.out
Hello, how are you?
The output when you use –cond hostname% pc -xl –cond debug.p hostname% a.out
Hello, how are you?
Fine, thank you.
The
%else
Directive
The %else directive provides an alternative action to the %if directive.
Syntax
%if expression %then
.
.
%else
.
.
%endif
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The Pascal program, if_then_else.p
Example program if_then_else (output);
%var red begin
%if red %then writeln ('It is red.');
%else writeln ('It is not red.')
%endif end.
The output when you compile if_then_else.p
without the
-config hostname% pc -xl if_then_else.p hostname% a.out
It is not red.
The output when you supply
-config with the argument red hostname% pc -xl -config red if_then_else.p hostname% a.out
It is red.
The
%elseif
Directive
The %elseif directive provides an alternative action to the %if directive.
Syntax
%if expression %then
.
.
%elseif expression %then
.
.
%endif
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The Pascal program, elseif.p
Comments
If the expression in %if expression %then is false , pc skips over the %then part and executes the %elseif part instead. expression consists of a conditional variable and the optional boolean operators, and , or , and not .
See the %else listing for examples of expression.
Example program elseif_example(output);
{ This program demonstrates the use of the
%if, %then, and %elseif directives. }
%var blue red begin
%if blue %then
writeln('The color is blue.');
%elseif red %then
writeln('The color is red.');
%endif end. { elseif_example }
The output when you supply
-config with the argument blue hostname% pc -xl -config blue elseif.p hostname% a.out
The color is blue.
The output when you supply
-config with the argument red hostname% pc -xl -config red elseif.p hostname% a.out
The color is red.
The
%elseifdef
Directive
The %elseifdef directive provides an alternative action to the %ifdef directive.
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Syntax
%ifdef expression %then
.
.
%elseifdef expression %then
.
.
%endif
Comments
If the expression in %ifdef expression %then is false , pc skips over the
%then part and executes the %elseifdef part instead. expression consists of a conditional variable and the optional boolean operators, and , or , and not .
See the %else listing for examples of expression.
Example
The Pascal program, ifdef.p
, which first checks if bird1 has been defined. If not, it defines it with a %var directive. If bird1 has been defined, the program checks whether or not it needs to define bird2 .
program ifdef_example(output);
%include 'bird.h'; begin
%ifdef not(bird1) %then
%var bird1
%elseifdef not(bird2) %then
%var bird2
%endif;
%if bird1 %then
writeln('Bird one is a ', a, '.');
%elseif bird2 %then
writeln('Bird two is a ', b, '.')
%endif end. { ifdef_example }
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The include file, bird.h
var
a: array[1..7] of char := 'penguin';
b: array[1..6] of char := 'toucan';
%var bird1
The output when you enable bird1 with the -config option hostname% pc -xl -config bird1 ifdef.p hostname% a.out
Bird two is a penguin.
The output when you enable bird2 with the -config option hostname% pc -xl -config bird2 ifdef.p hostname% a.out
Bird two is a toucan.
The
%enable
Directive
The %enable directive sets a conditional variable to true .
Syntax
%enable var1 ..., varN
Comments
A defined conditional variable is enable ( true ) when it appears in either the
%enable directive or in the -config option. Conditional variables are false by default.
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Example
The Pascal program, enable.p
. This example sets the conditional variable two to true , which is equivalent to setting the -config option to two on the command-line.
program enable_example(output);
{ This program demonstrates the use of
the %enable compiler directive. } var
a: integer;
b: integer;
%var one, two
%enable two begin
%if one %then
a := maxint;
writeln('One is defined as ', a:2, '.');
%endif
%if two %then
b := minint;
writeln('Two is defined as ', b:2, '.');
%endif end. { enable_example }
The commands to compile and output enable.p
hostname% pc -xl enable.p hostname% a.out
Two is defined as -32768.
The
%endif
Directive
The %endif directive indicates the end of a %if or %ifdef directive. See the sections on %if and %ifdef for more information on this directive.
The
%error
Directive
The %error directive causes the compiler to print a string on the standard output and treat it as an error.
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Syntax
%error ' string '
Comments pc does not produce an object file.
Example
The Pascal program, error.p
program error_example(output);
{ This program demonstrates the use of the
%error compiler directive. }
%var arch begin
%if arch %then
writeln('This is a SPARC computer.');
%else
%error 'Unknown architecture.'
%endif end. { error_example } error.p
produces this error if you compile it without the
–config sparc option.
hostname% pc -xl error.p
Tue Feb 28 17:10 1995 error.p
Line 12 : %error 'Unknown architecture.'
E --------------------^---'Unknown architecture.'
Compilation failed
The
%exit
Directive
The %exit directive instructs the compiler to stop processing the current
Pascal source file.
Syntax
%exit
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The Pascal program, exit_directive.p
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Comments
If the compiler encounters an %exit directive within an include file, it stops processing the include file, but continues processing the source file in which it is included. In effect, %exit is equivalent to an end-of-file marker.
When the compiler processes an %exit directive within an %if or %ifdef construct, it closes all %if or %ifdef s before it stops processing the current file.
Example program exit_directive(output); begin
writeln('Hello, world!') end. { exit_directive }
%exit
Everything after the %exit is ignored.
So you can put anything here.
The commands to compile and execute exit_directive.p
hostname% pc -xl exit_directive.p hostname% a.out
Hello, world!
The
%if
Directive
The %if directive is a conditional branching directive.
Syntax
%if e xpression %then
.
.
%end if
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Comments
When pc encounters a %if directive, it evaluates expression. If expression is true , pc executes the statements in the %then part. If expression is false , pc skips over the %then part and executes the %else , %elseif , or %endif directive. If no such directive exists, pc proceeds to the next statement.
The expression consists of a conditional variable and the optional boolean operators and , or , and not . You can set a conditional variable on the command-line by using the -config option. See “–config” on page 27 for information on this option.
Assuming one and two are conditional variables, expression can be any of the following: one two one and two one or two not one not two
Example
See the example in the %else listing on page 250.
The
%ifdef
Directive
The %ifdef directive determines whether or not you previously defined a conditional variable in a %var directive.
Syntax
%ifdef expression %then
.
.
%elseifdef expression %then
.
.
%endif
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The program unit, include_prog.p
A
Comments
expression consists of a conditional variable and the optional boolean operators and , or , and not . See the %else listing for examples of expression.
%ifdef is especially useful for determining whether or not a conditional variable has been declared in an include file.
Example
See the example in “The %elseifdef Directive.”
The
%include
Directive
The %include directive inserts lines from the specified file in the input stream.
Syntax
%include ' filename
' ;
Comments
When cppas encounters the %include directive, it inserts the lines from the file name into the input stream.
Example program include_prog;
%include 'extern.h'; begin
global := 1;
writeln('From MAIN, before PROC: ',global);
proc;
writeln('From MAIN, after PROC: ',global); end. { include_prog }
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The module unit, include_mod.p
module include_mod; define
global, proc;
%include 'extern.h'; procedure proc; begin
writeln('From PROC : ',global);
global := global + 1; end; { proc }
The include file, include.h
var
global : integer; procedure proc; extern;
The commands to compile and execute ext_prog.p
and ext_mod.p
hostname% pc -xl include_prog.p include_mod.p include_prog.p: include_mod.p:
Linking: hostname% a.out
From MAIN, before PROC:1
From PROC : 1
From MAIN, after PROC:2
The
%list
Directive
The %list directive enables a listing of the program.
Syntax
%list;
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The Pascal program, list.p
A
Comments
The %list directive and the -l compiler option perform the same function.
Example program list_example(output);
{ This program demonstrates the use of the %list
and %nolist directives. }
%list;
%include 'types.h';
%nolist; begin
pri := [red, yellow, blue];
pos := [true, false];
cap := ['A'..'Z'];
dig := [0..100]; writeln('There are ',card(pri): 4, ' primary colors.'); writeln('There are ',card(pos): 4, ' possibilities.'); writeln('There are ',card(cap): 4, ' capital letters.''); writeln('There are ',card(dig): 4, ' digits.') end. { list_example }
The include file, types.h
type
lowints = 0..100;
primary_colors = set of (red, yellow, blue);
possibilities = set of boolean;
capital_letters = set of 'A'..'Z';
digits = set of lowints; var
pri: primary_colors;
pos: possibilities;
cap: capital_letters;
dig: digits;
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The listing includes the time each unit was compiled and the name of each unit compiled.
hostname% pc -xl list.p
Tue Feb 28 15:48 1995 list.p:
6 %list;
Tue Feb 28 15:50 1995 ./types.h:
1 type
4
5
2
3
6 lowints = 0..100; primary_colors = set of (red, yellow, blue); possibilities = set of boolean; capital_letters = set of 'A'..'Z'; digits = set of lowints;
8 var
9 pri: primary_colors;
10
11 pos: possibilities; cap: capital_letters;
12 dig: digits;
Tue Feb 28 15:52 1995 list.p:
7 %include 'types.h'; hostname% a.out
There are 3 primary colors
There are 2 possibilities
There are 26 capital letters
There are 101 digits
The
%nolist
Directive
The %nolist directive disables the program listing.
Syntax
%nolist;
Comments
%nolist is the default.
Example
See the example under “The %list Directive.”
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The
%slibrary
Directive cppas treats %slibrar y in the same manner as the %include directive. See
“The %include Directive” on page 259.
The
%var
Directive
The %var directive defines conditional variables for the preprocessor.
Syntax
%var var1 ..., varN
Comments
A conditional variable is defined when it appears in a %var directive; otherwise, it is undefined.
Example
See the example under “The %config Directive” on page 247.
The
%warning
Directive
The %warning directive instructs pc to print a string on the standard output as a compiler warning.
Syntax
%warning ' string '
Comments pc produces an object file.
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The Pascal program, warning.p
Example program warning_example(output);
{ This program demonstrates the use of the
%warning compiler directives. }
%var blue begin
%if blue %then
writeln('The color is blue.');
%else
%warning 'Color not defined'
%endif end. { warning_example }
The output when you compile warning.p
without the
–config option hostname% pc -xl warning.p
Fri Mar 3 15:03 1995 warning.p
Line 12:%warning 'Color not defined' w -------------------^----- 'Architecture not defined'
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Error Messages
B
The following is a list of the error messages produced by Pascal, arranged by message number.
10010: Builtin <function> takes exactly <number> argumen ts
10020: Builtin <function> takes at least <number> arguments
10030: Builtin <function> takes at least <number> arguments and at most <number>
10040: Built-in <function> cannot be passed as a parameter
10050: argv takes two arguments
10060: argv's first argument must be an integer, not <type>
10070: argv's second argument must be a string, not <type>
10080: Argument to card must be a set, not <type>
10090: flush takes at most one argument
10100: flush's argument must be a file, not <type>
10110: Not enough arguments to <function>
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B
266
10120: Too many arguments to <function>
10130: Actual argument cannot be conformant array
10140: Actual argument is incompatible with formal var parameter <identifier> of <function>
10150: Actual argument is incompatible with formal
<paramtype> parameter <identifier> of <function>
10160: Actual argument to NONPASCAL procedure cannot be conformant array
10170: Extra arguments to ADDR ignored
10180: Argument to <function> must be of type <type> , not
<type>
10190: Second argument to <function> must be of type <type> , not <type>
10200: First argument to <function> must be of type <type> , not <type>
10210: Illegal argument to IN_RANGE
10220: Type clash in argument to IN_RANGE
10230: Illegal argument to ADDR
10240: Third argument to <function> must be of type <type> , not <type>
10250: Argument to ADDR is a dynamically allocated variable
<identifier>
10260: Argument to ADDR is an internal variable <identifier>
10270: Argument to ADDR is a nested function <function>
10280: Argument to ADDR is an internal procedure <function>
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10290: Fourth argument to <function> must be of type <type> , not <type>
10300: First argument to <function> cannot be a univ_ptr
10310: < number > argument to < function > must be of type < type >, not < type >
10320: < number > argument to < function > must be unpacked
10330: < number > argument to < function > must be packed
10340: <function> (line <number> ) has <number> arguments
10350: Transfer functions take exactly one argument
10360: sizeof takes at least 1 argument
10370: Formal arguments should be given only in forward declaration
10380: Types must be specified for arguments
10390: Each procedure/function argument must be declared separately
10400: <function> takes no arguments
10410: <function> takes either zero or one argument
10420: <function> takes exactly one argument
10430: <function> 's argument must be integer or real, not
<type>
10440: seed's argument must be an integer, not <type>
10450: <function> 's argument must be a real, not <type>
10460: <function> 's argument must be an integer or real, not
<type>
Error Messages 267
B
268
10470: ord's argument must be of scalar type, not <type>
10480: <function> 's argument must be of scalar type, not
<type>
10490: odd's argument must be an integer, not <type>
10500: chr's argument must be an integer, not <type>
10510: Argument to eoln must be a text file, not <type>
10520: Argument to eof must be file, not <type>
10530: Transfer functions take only one argument
10540: Arguments to <function> must be variables, not expressions
10550: Read requires an argument
10560: Write requires an argument
10570: Message requires an argument
10580: null takes no arguments
10590: <function> expects one argument
10600: Argument to <function> must be a file, not <type>
10610: <function> expects one or two arguments
10620: First argument to <function> must be a file, not <type>
10630: Second argument to <function> must be a string, not
<type>
10640: <function> expects at least one argument
10650: (First) argument to <function> must be a pointer, not
<type>
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10660: Second and successive arguments to <function> must be constants
10670: Argument to <function> must be a alfa, not <type>
10680: halt takes no arguments
10690: stlimit requires one argument
10700: stlimit's argument must be an integer, not <type>
10710: remove expects one argument
10720: remove's argument must be a string, not <type>
10730: linelimit expects two arguments
10740: linelimit's second argument must be an integer, not
<type>
10750: linelimit's first argument must be a text file, not
<type>
10760: page expects one argument
10770: Argument to page must be a text file, not <type>
10780: Assert expects one or two arguments
10790: Second argument to assert must be a string, not
<type>
10800: pack expects three arguments
10810: unpack expects three arguments
10820: Illegal transfer function argument
10830: constant argument expected
Error Messages 269
B
270
10840: Illegal argument with format radix specification; probably a comma missing
11010: have incompatible conformant array schemas
11020: sizeof(conformant array) is undefined
11030: Conformant arrays are not allowed at ANSI Level 0
11040: Subscripting allowed only on arrays, not on <type> s
11050: subrange value or array subscript ( <integer> ) is out of range
11060: compiler takes size of array
11070: Elements of a packed array cannot be passed by reference
11080: Subscripting allowed only on arrays and varying, not on <type> s
11090: Varying size must be a constant
11100: Size of <identifier> is zero
11110: Character array lower bound <> 1
11120: Character array upper bound of 1
11130: <function> requires a to be an unpacked array, not
<type>
11140: <function> requires z to be a packed array, not <type>
11150: <operation> not allowed on arrays - only allow = and
<>
11160: Packed multidimensional conformant arrays are not permitted
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11170: For-statement variable <identifier> cannot be an element of a record
11180: . allowed only on records, not on <type> s
11190: <identifier> is not a field in this record
11200: Record required when specifying variant tags
11210: Missing case constants in variant record
11220: <identifier> is a duplicate field name in this record
11230: Duplicate variant case label in record
11240: <operation> not allowed on records - only allow = and
<>
11250: Variable in with statement refers to <identifier> , not to a record
11260: Too many tag fields
11270: No variant case label value equals specified constant value
11280: Tag fields cannot be <type> s
11290: Bad variant constant
11300: variant required after case
12010: Assert expression must be Boolean, not <type> s
12020: illegal transfer function with <identifier>
12030: Illegal transfer function
12040: Transfer functions on bit fields not implemented
12050: Oct/hex allowed only on writeln/write calls
Error Messages 271
B
272
12060: Width expressions allowed only in writeln/write calls
12070: Cannot write <type> s with two write widths
12080: Can't write <identifier> s with oct/hex
12090: First write width must be integer, not <type>
12100: Second write width must be integer, not <type>
12110: Negative widths are not allowed
12120: Cannot write unpacked array to textfile
12130: Can't read <type> s from a text file
12140: Can't 'readln' a non text file
12150: Oct/hex allowed only on text files
12160: Write widths allowed only on text files
12170: Cannot write unpacked array to textfile
12180: Can't write <type> s to a text file
12190: Can't 'writeln' a non text file
13010: constant identifier required
13020: Constant value cannot be evaluated at compile-time
13030: Constant too large for this implementation
13040: <identifier> is a constant and cannot be qualified
13050: Constant string too long
13060: Constant expression is required
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13070: constant argument expected
13080: newline in string or char constant
13090: empty character constant
13100: too many characters in character constant
14010: Constant declarations should precede type, var and routine declarations
14020: Label declarations should precede const, type, var and routine declarations
14030: Type declarations should precede var and routine declarations
14040: All types should be declared in one type part
14050: All constants should be declared in one const part
14060: INTERNAL ignored, procedure was previously declared
PUBLIC or as EXTERNAL
14070: <function> has already been declared forward
14080: Unknown language <identifier> in EXTERN procedure declaration ignored
14090: Unresolved forward declaration of <function>
14100: <identifier> DEFINED, but not declared
14110: label <identifier> was declared but not defined
14120: PUBLIC procedures must be declared at outer block level
14130: PRIVATE ignored, procedure was declared DEFINED previously
Error Messages 273
B
274
14140: PUBLIC ignored, procedure was declared INTERNAL or
PRIVATE previously
14150: PRIVATE ignored, procedure was declared PUBLIC or as
EXTERNAL previously
14160: For-statement variable <identifier> must be declared in the block in which it is used
14170: All labels should be declared in one label part
14180: Expected identifier VARYING in declaration
14190: Variable declarations should precede routine declarations
14200: All variables should be declared in one var part
14210: public vars must be declared at outer block level
14220: Declarations may not be both STATIC and PUBLIC,
STATIC is ignored
14230: Declarations may not be both DEFINE and PRIVATE,
DEFINE is ignored
14240: Declarations may not be both EXTERN and PRIVATE,
EXTERN is ignored
14250: <identifier> was declared in a DEFINE, cannot be STATIC
14260: <identifier> was declared in a DEFINE, cannot be PRIVATE
14270: <identifier> used as both a field and a type name in a record definition
14280: cannot DEFINE <identifier> , variable was not previously declared as EXTERN
14290: Declaration found when statement expected
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14300: Expected keyword begin after declarations, before statements
14310: Improper initialization for variable <identifier>
14320: <identifier> is already defined globally
14330: Definition of name <identifier> after applied use in
<identifier>
14340: Definition of name <identifier> after applied use
14350: <identifier> is already defined in this block
14360: Range lower bound exceeds upper bound
14370: '*' subrange descriptor used in illegal context
14380: Cannot initialize dynamic local variables
15010: File <identifier> listed in program statement but not declared
15020: File <identifier> listed in program statement but declared as a <identifier>
15030: File <identifier> listed in program statement but defined as <identifier>
15040: Files cannot be passed by value
15050: Files cannot be a component of <identifier > passed by value
15060: Pre-defined files input and output redefined
15070: Files cannot be members of files
15080: Missing closing <quote or bracket> for include file name
15090: Include filename must end in .i or .h
Error Messages 275
B
276
15100: Cannot open #include file <filename>
15110: line <number> does not exist in file <identifier>
15120: End-of-file expected - QUIT
15130: Unexpected end-of-file - QUIT
16010: <identifier> is not a function
16020: Too many levels of function/procedure nesting
16030: No assignment to the function variable
16040: Functions should not return <type> s
16050: Procedure/function nesting too deep
16060: pcc_fvar(): no result for this function
16070: <identifier> is a <class> , not a function
16080: Illegal function qualification
16090: compiler takes size of function
16100: Can't call <identifier> , its not a pointer to a procedure or function
16110: Can't qualify a function result value
16120: Cannot assign value to built in function
16130: INTERNAL option illegal for procedure pointer option ignored
16140: Unknown option for procedure pointer ignored :
<option>
16150: Too many levels of function/procedure nesting
Pascal 4.0 User’s Guide
B
16160: Procedure/function nesting too deep
16170: Can't call <identifier> , its not a pointer to a procedure or function
16180: Can't call <identifier> , it's <class> not a procedure
16190: Procedure <identifier> found where expression required
16200: Illegal procedure call, expecting value
16210: Non-pascal routine <identifier> will fail if called indirectly from pascal
16220: Passing nested routine <identifier> to non-pascal routine <identifier>
16230: Can't call <identifier> , its not a pointer to a procedure or function
17010: Case label out of range
17020: Real constant out of range for this implementation
17030: Short real out of range for this implementation
17040: Short real <number> out of range for this implementation
17050: Implementation restriction: sets must be indexed by
16 bit quantities
17060: Subscript of <identifier> is out of range
17070: Subscript value of <number> is out of range
17080: subrange value or array subscript ( <integer> ) is out of range
17090: Successor of <integer> is out of range
Error Messages 277
B
278
17100: Predecessor of <integer> is out of range
17110: Value of <integer> is out of range
17120: Range upper bound of <integer> out of set bounds
17130: Range lower bound of <integer> out of set bounds
17140: Value of <integer> out of set bounds
17150: value of <integer> (initial assign. to for loop variable) is out of range
17160: Value of <integer> (terminal assign. to for loop variable) is out of range
17170: Tag type is out of range
17180: Base out of range (2..36)
18020: (* in a (* ... *) comment
18030: { in a { ... } comment
18040: Comment does not terminate - QUIT
18050: Illegal character, use the -xl option to process % compiler directives
18060: Illegal character
18070: unexpected EOF
18080: Point of error
18090: Parsing resumes
18100: Parse stack overflow
18110: Expression passed to UNIV formal <identifier> was converted to <type> of size <number> bytes
Pascal 4.0 User’s Guide
B
18120: 8 or 9 in octal number
18130: Number too large for this implementation
18140: <operation> is undefined for reals
18150: <identifier> cannot have more elements in z ( <integer> ) than in a ( <integer> )
18160: <identifier> is an unimplemented extension
18180: Initializer must be a string
18190: Initialization string <string> is too long
18200: Expected 'options', not <identifier>
18210: Unknown option ignored : <identifier>
18220: Duplicate options specification : <identifier>
18230: Unimplemented option ignored : <identifier>
18240: <identifier> undefined on line <number>
18250: <identifier> improperly used on line <number>
18260: <identifier> is neither used nor set
18270: <identifier> is never used
18280: <identifier> is used but never set
18290: Length of external label for identifier <identifier> exceeds implementation limit
18300: Applied use of <identifier> before definition in this block
18320: <operation> is forbidden for reals
Error Messages 279
B
280
18420: Undefined <identifier>
18430: Undefined identifier
18440: Improper <identifier> identifier
18450: Deleted <token>
18460: Replaced <token> with a <token>
18470: Replaced <class> id with a <class> id
18480: Inserted <token>
18490: Expected <token>
18500: Label <identifier> not defined in correct block
18510: Label <identifier> redefined
18520: <identifier> is undefined
18530: ^ allowed only on files and pointers, not on <type> s
18540: Pascal uses [] for subscripting, not ()
18550: Error occurred on qualification of <identifier>
18560: division by 0
18580: Variable required in this context
18590: Universal pointers may not be dereferenced
18600: Illegal format
18610: Unknown format radix <identifier> ignored, expecting hex or oct
18620: Expression required
Pascal 4.0 User’s Guide
B
18630: Unreachable statement
18640: Unrecoverable syntax error - QUIT
18650: Too many syntax errors - QUIT
18660: Input line too long - QUIT
18670: Unrecognizable # statement
18680: Include syntax error - expected ' or \" not found
18690: Absurdly deep include nesting - QUIT
18700: Too many levels of include nesting - QUIT
18710: Bad arbitrary base integer
18720: Bad base <number> number, <number>
18730: Digits required after decimal point
18740: Digits required before decimal point
18750: Digits required in exponent
18760: Space required between number and word-symbol
18770: Character/string delimiter is '
18780: Unmatched ' for string
18790: Null string not allowed
18800: Invalid preprocessed file (probably renamed as
'.p'). Compile the original .p file with -sb again
19010: Module name expected after keyword MODULE
19020: Identifiers after module name ignored
Error Messages 281
B
282
19030: Missing program statement
19040: Input is used but not defined in the program statement
19050: Output is used but not defined in the program statement
19060: Program parameter <identifier> is repeated
20010: Left operand of <operator> must be integer, real or set, not <type>
20020: Right operand of <operator> must be integer, real or set, not <type>
20030: Cannot mix sets with integers and reals as operands of <type>
20040: Operands of <operator> must be Boolean or Integer
20050: Left operand of / must be integer or real, not <type>
20060: Right operand of / must be integer or real, not
<type>
20070: Left operand of <operator> must be Boolean, not <type>
20080: Right operand of <operator> must be Boolean, not <type>
20090: Left operand of <operator> must be integer, not <type>
20100: Right operand of <operator> must be integer, not <type>
20110: Right operand of 'in' must be a set, not <type>
20120: Operands of + are of incompatible types
20130: Operand of <operator> must be integer or real, not
<type>
Pascal 4.0 User’s Guide
B
20140: Operands of <operator> must both be sets
20150: Set types of operands of <operator> must be compatible
20160: Incorrect statement usage const. with operand
20170: ^ allowed only on files and pointers, not on <type> s
20180: <operation> is an illegal operation on strings
20190: not must operate on a Boolean or Integer, not <type>
20200: not must operate on a Boolean, not <type>
20210: <operation> not allowed on pointers - only allow = and
<>
20220: Strings not same length in <operator> comparison
20230: <identifier> s and <identifier> s cannot be compared operator was <operator>
20240: <identifier> s may not participate in comparisons
21010: Attempt to pass IN parameter to formal reference parameter
21020: Expression type clashed with type of value parameter
<identifier> of <identifier>
21030: Expression given (variable required) for var parameter <identifier> of <identifier>
21040: Parenthesis not allowed for var parameter <identifier> of <identifier>
21050: Parameter type not identical to type of var parameter <identifier> of <identifier>
21060: Packed/unpacked type conflict between formal and actual parameters
Error Messages 283
B
284
21070: Conformant array parameters in the same specification must be the same type
21080: actual parameter is not an array
21090: array index type is incompatible with conformant array parameter <identifier>
21100: array index type is not within of index type of conformant array parameter <identifier>
21110: array index type is not within range[ <number> ..
<number> ] of index type of conformant array parameter <identifier>
21130: <class> <identifier> given for formal <class> parameter
<identifier>
21140: does not match type of formal <class> parameter
<identifier> (line <number> )
21150: <class> parameter <identifier> of <identifier> (line <number> )
21160: does not match <class> parameter <identifier> of <identifier>
(line <number> )
21170: Type of <class> parameter <identifier> of <identifier> (line
<number> )
21180: does not match type of <class> parameter <identifier> of
<identifier> (line <number> )
21190: Parameter congruity error: incompatible groupings
21200: Packed/unpacked type conflict between parameters of
<identifier> and <identifier>
21210: than formal <class> parameter <identifier> (line <number> )
21220: Conformant array parameter bound symbol table entry is NULL
Pascal 4.0 User’s Guide
B
21230: Program parameter <identifier> is repeated
21240: Previous declaration for formal parameter ' <identifier> ' has different type
21250: Previous declaration for formal parameter ' <identifier> ' has different name ' <identifier> '
21260: Previous declaration for procedure ' <identifier> ' had different number of formal parameters
21270: Formal <class> <name> cannot be qualified
21280: <class> <name> cannot be qualified
21290: Expression given, <class> required for <class> parameter
<identifier>
21300: Variable given, <class> required for <class> parameter
<identifier>
21310: Cannot take value of OUT parameter
21320: Invalid assignment to a parameter marked as IN
21330: Parameter congruity error: incompatible groupings
21340: UNIV parameter <identifier> should be passed as a var parameter
21350: Fields which select variant parts may not be passed by reference
21360: Cannot pass components of packed structures by reference
21370: Cannot pass components of packed structures by VAR,
OUT, or IN/OUT
22010: Ran out of memory (gentypind)
Error Messages 285
B
286
22020: Ran out of memory (case)
22030: Ran out of memory (hash)
22040: Ran out of memory (TRIM)
22050: Ran out of memory (defnl)
22060: Ran out of memory (buffer_ir_pass)
22070: Ran out of memory (string)
22080: Ran out of memory (tralloc)
22090: out of memory (tstr)
22100: out of memory
22110: Ran out of hash tables
22120: Ran out of tree tables
22130: Out of space (put_on_idlist)
22140: out of tree space; try simplifying
22150: out of temporary string space
23010: <identifier> is a non-standard function
23020: <identifier> is a non-standard procedure
23030: Two argument forms of reset and rewrite are nonstandard
23040: NIL values in const declaration are non-standard
23050: Set constants in const declaration are non-standard
23060: Expressions in const declaration are non-standard
Pascal 4.0 User’s Guide
B
23070: Routine Options are not standard
23080: External procedures and functions are not standard
23090: Separately compiled routine segments are not standard
23100: UNIV parameters are non-standard
23110: IN parameters are non-standard
23120: OUT parameters are non-standard
23130: IN OUT parameters are non-standard
23140: <identifier> is a nonstandard function
23150: OTHERWISE clause in case statements is non-standard
23160: Ranges in case statements are non-standard
23170: Transfer functions are non-standard
23180: Reading scalars from text files is non-standard
23190: Writing <type> s with two write widths is non-standard
23200: Zero widths are non-standard
23210: Oct and hex are non-standard
23220: Writing <type> s to text files is non-standard
23230: <identifier> is a nonstandard procedure
23240: Short-circuit operators are non-standard
23250: <operator> comparison on sets is non-standard
23260: record comparison is non-standard
Error Messages 287
B
288
23270: Storage Class non-standard
23280: Initialization in declaration part is non-standard
23290: UNIV_PTR types are non-standard
23300: '_' in an identifier is nonstandard
23310: Octal constants are non-standard
23320: <operator> is non-standard
24010: Cannot exit -- not within a loop
24020: For-statement variable <identifier> must be unqualified
24030: For-statement variable <identifier> cannot be an element of a record
24040: For-statement variable <identifier> may be illegally changed at line <number>
24050: For-statement variable <identifier> must be declared in the block in which it is used
24060: For-statement variable <identifier> cannot be <type> s
24070: Can't modify the for-statement variable <identifier> in the range of the loop
24080: Incorrect control variable
24090: Type of initial expression clashed with index type in 'for' statement
24100: Type of limit expression clashed with index type in
'for' statement
24110: Can't modify the for variable <identifier> in the range of the loop
Pascal 4.0 User’s Guide
B
24120: Case selectors cannot be <type> s
24130: Duplicate otherwise clause in case statement
24140: Case label type clashed with case selector expression type
24150: Multiply defined label in case, lines <number> and
<number>
24160: No case-list-elements
24170: Bad case constant
24180: Range in case label must be in ascending order
24190: Maximum number of case selectors exceeded
24200: Cannot next -- not within a loop
24210: Goto <label> is into a structured statement
24220: Goto <label> from line <number> is into a structured statement
24230: Variable in with statement refers to <type> , not to a record
24240: Maximum WITH nesting depth exceeded, ignoring WITH variables
24250: Variable in with statement not correct
24260: cannot assign to lhs
24270: Variable required
24280: <class> <identifier> found where variable required
24290: univ_ptr variable cannot be dereferenced in assignment
Error Messages 289
B
290
24300: Improper use of the DEFINE statement
24310: End matched <keyword> on line <number>
24320: Inserted keyword end matching {begin|record|class} on line <number>
25010: {pack|unpack}: elements of a and z must have the same type
25020: component types of formal and actual arrays are not conformable
25030: Type of function <name> (line <number> )
25040: Case label type clashed with case selector expression type
25050: Type clash: initializer must be a pointer
25060: Type clash: type of initializer does not match type of array
25070: Type clash: Integer is incompatible with real
25080: Type clash: Initializer out of range
25090: Type clash: real is incompatible with integer
25100: This resulted because you used '/' which always returns real rather
25110: than 'div' which divides integers and returns integers
25120: Type clash: non-identical scalar types
25130: Type clash: unequal length strings
25140: Type clash: varying char and unknown
Pascal 4.0 User’s Guide
B
25150: Type clash: packed and unpacked set
25160: Type clash: files not allowed in this context
25170: Type clash: non-identical <class> types
25180: Type clash: <type> s with file components not allowed in this context
25190: Type clash: <type> is incompatible with <type>
25200: Type clash: string and unpacked array
25210: Type clash: string and packed array with lower bound
<> 1
25220: Type clash: Non-identical string types must be packed
25230: Type clash: packed array with lower bound <> 1
25240: Set default type 'intset' is not a set
25250: Upper bound of element type clashed with set type in constant set
25260: Lower bound of element type clashed with set type in constant set
25270: Element type clashed with set type in constant set
25280: Set elements must be scalars, not <type> s
25290: Set of real is not allowed
25300: Procedures cannot have types
25310: Function type can be specified only by using a type identifier
Error Messages 291
B
292
25320: Function type should be given only in forward declaration
25330: Different type declared previously for function return <name>
25340: Function type must be specified
25350: Type of expression in while statement must be
Boolean, not <type>
25360: Until expression type must be Boolean, not <type> , in repeat statement
25370: Array index type incompatible with declared index type
25380: Too many subscripts
25390: Bad type of variable used for call
25400: Transfer functions only work on types of the same size
25410: Only type char allowed in varying array
25420: Type mismatch in read from non-text file
25430: Type mismatch in write to non-text file
25440: Specified tag constant type clashed with variant case selector type
25460: Tag type is out of range
25470: Variant label type incompatible with selector type
25480: set types must be compatible in comparisons operator was <operator>
Pascal 4.0 User’s Guide
B
25490: <class> types must be identical in comparisons operator was <operator>
25500: Index type clashed with set component type for 'in'
25510: Operands of + are of incompatible types
25520: Type names (e.g.
<type> ) allowed only in declarations
25530: Type name (e.g.
<type> ) found in illegal context
25540: Set types of operands of <operator> must be compatible
25550: expression has invalid type
25560: Type of expression clashed with type of variable in assignment
25570: Type of expression in if statement must be Boolean, not <type>
25580: Type of transfer function does not match type of right side
25590: <identifier> is a <class> , not a type as required
25600: Set type must be range or scalar, not <type>
25610: Sets must have basetype with range <number> ..
<number>
25620: Subrange type cannot contain a expression
25630: Scalar types must be identical in subranges
25640: Can't mix <identifier> s and <identifier> s in subranges
25650: Subrange of real is not allowed
25660: Subrange bounds must be Boolean, character, integer or scalar, not <type>
Error Messages 293
B
294
25670: Index type for arrays cannot be real
25680: Array index type is a <type> , not a range or scalar as required
25690: Packed conformant array schema requires type identifier as element type
25700: Illegal type in VARYING array, only type CHAR allowed
25710: Size of <type> type exceeds implementation limits
25720: Initializer must be a constant value of same type
26010: Malformed program statement
26020: Malformed declaration
26030: Malformed const declaration
26040: Malformed type declaration
26050: Malformed var declaration
26060: Malformed record declaration
26070: Malformed statement in case
26080: Malformed statement
26090: Missing/malformed expression
26100: Label restricted to 4 digits
26110: Label declared non-integer
26120: Replaced unknown parameter specifier <identifier> with
OUT
26130: Deleted ';' before keyword else
Pascal 4.0 User’s Guide
B
26140: Extension to WITH statement not allowed
27010: Integer overflow in constant expression
The following are internal error messages. If any of them is displayed, contact
Sun Customer Support.
18330: NAME with no symbol table entry
18340: ir_symbol: unknown class
18350: ir_leaf: cannot take address of op <identifier>
18360: ir_leaf: illegal leaf node, op = <identifier>
18370: ir_starg: illegal STARG
18380: ir_exit: no return label
18390: cannot take address of op < identifier >
18400: op '< identifier >' not implemented yet
18410: goal < integer > not defined for op < operation >
18570: wasted space: < number >
Error Messages 295
B
296 Pascal 4.0 User’s Guide
Index
A
–a option to pc command, 24 a.out
, 2, 8, 9, 17 address parameters, 169 alignment of types in FORTRAN, 165 and operator, 38
AnswerBook, xxii arguments, See parameters arithmetic exceptions in math libraries, 239 arrays, conformant parameters by value, 101, 114, 123,
193 as (1) assembler, 40, 57 assert statement, 25 attributes for XView, 224 automatic replacement of errors, 207
Auto-Read definition, 61 for dbx , disable, 61
B
–B option to pc command, 24
-b option to pc command, 25 block buffering of program output, 25 boolean expression, 36, 38 breaking a program into parts, 67
-bsdmalloc option to pc command, 25 buffering of program output, controlling, 24 built-in function and procedure type errors, 211
C
-C option to pc command, 25, 49
–c option to pc command, 26
C programming language, 89 to 134, 245 arrays by value, 114
C calls Pascal, 93 to 116 compatible types, 90 function return values, 115, 130 global variables in C and Pascal, 133 parameter passing, 93 parameters as pointers to procedures, 131
Pascal calls C, 117 to 132 interface, 89 procedures and functions as parameters, 131 records and structures, 105, 124 sharing declarations, 88 strings by value, 114 value parameters, 129 to 130
297
298 var parameters, 94, 117
C++ programming language, 137 to 162 arguments, passing of by reference, 139, 155 by value, 150, 157 arrays, fixed, 144
C++ calls Pascal, 138 to 155 character strings, 142 compatible types, 138 compiler options, 137 function return values, 152, 159 functions, 155 global variables in C++ and
Pascal, 161
-lpc and -lc options, 137 name encoding, 138 parameter passing, 152
Pascal calls C++, 155 to 160 file pointers to C++, 162 interface, 137 records and structures, 146 value parameters, 158
-calign option to pc command, 26 cg , the code generator, 18
–cg89 option to pc command, 26
–cg92 option to pc command, 26 character data type, 33, 46 characters, illegal, 205 compatible types
Pascal and C, 90
Pascal and C++, 138
Pascal and FORTRAN, 165 compiler, 8, 11, 17 to 66 driver, 18 panics, 217 compiler directives, 246 to 263
#include , 67
%config , 247
%debug , 27, 249
%else , 250
%elseif , 251
%elseifdef , 252
%enable , 246, 254
%endif , 255
%error , 255
%exit , 256
%if , 247, 257
%ifdef , 255, 257, 258
%include , 259, 263
%list , 260
%nolist , 262
%slibrary , 263
%var , 247, 258, 263
%warning , 263 compiler semantic errors, 210 to 217 can’t read and write scalars, 212 expression diagnostics, 212 function and procedure type errors, 211 goto statement, 216 incompatible types, 210 procedures and functions as parameters, 211 scalar, 211 type equivalence, 214 uninitialized variables, 216 unreachable statements, 215 unused item errors, 216 compiler syntax errors, 205 to 209 digits in real numbers, 206 expected symbols, malformed constructs, 208 expected, unexpected, end-of-file,
QUIT , 209 illegal characters, 205 replacements, insertions, deletions, 207 string errors, 206 undefined or improper identifiers, 208 compiling a Pascal program, 8, 13 units, 69 with libraries, XView, 224
–cond option to pc command, 27, 249 conditional compilation, 27 variables, 246
Pascal 4.0 User’s Guide
–config option, 245, 252, 256 defined, 246 undefined, 245
%config directive, 247
–config option to pc command, 27, 246,
252 conformant arrays parameters between Pascal and
C, 101, 114, 123 parameters between Pascal and
C++, 152, 158, 159 parameters between Pascal and
FORTRAN, 182, 193 conventions, xxi cpp
#include directive, 67 the C preprocessor, 18, 27, 40, 49, 245 cppas , 245 to 263 compiler directives, 246 to 263 conditional variables, 245 preprocessor, 27, 40 the -xl preprocessor, 18, 19
D
–D option to pc command, 27
–dalign option to pc command, 28 data type character, 33, 46 data types, XView, 226 dbx , 3, 31, 61
%debug compiler directive, 27, 249 debugger , 3 debugging disable Auto-Read for dbx , 61 fix-and-continue feature, 3 with dbx , 3 with –g option to pc command, 31 declarations define , 83 sharing between multiple units of different languages, 87
#define statement, 27 define declaration, 83 variable, 76 define variable, 82 diagnostics, format of, 210 digits in real numbers, 206 directives, See compiler directives
–dn option to pc command, 28 documentation, xxii to xxiii
DOMAIN Pascal, 27
–dryrun option to pc command, 28
–dy option to pc command, 28
E
%else directive, 250
%elseif directive, 251
%elseifdef directive, 252
%enable directive, 246, 254
%endif directive, 255 end-of-file errors, 209 enumerated types, 92, 166 equivalence of types, errors, 214
%error directive, 255 error recovery, 207 errors, 205 to 220 automatic replacement, 207 from incompatible types, 210 from uninitialized variables, 216 from unreachable statements, 215 from unused items, 216 illegal characters, 205 in constructs, 208 in ends of program files, 209 in expressions, 212 in function and procedure types, 211 in goto statement, 216 in identifiers, 208 in reading and writing scalars, 212 in real numbers, 206 in scalars, 211 in semantics, 210 in strings, 206 in symbols, 208 in syntax, 205
Index 299
300 in type equivalence, 214 out of memory, 217 runtime, 217 to 220 exception-handling function in math libraries, 240 executable file, 2, 9, 11, 18, 46 default, 9, 17 how to rename, 9 execution profile, 39
%exit directive, 256 expression diagnostics, 212 extended language features, 56 extern option, 86, 88 variable, 76 external option, See extern option
F
–fast option to pc command, 28 faster linking and initializing, 61 fbe (1) assembler, 40 features, Pascal compiler, 2 file name extensions, 20 variable, 12
-flags option to pc command, 32 floating-point, nonstandard, 29
–fnonstd option to pc command, 29
-fns option to pc command, 29 format of error diagnostics, 210
FORTRAN programming language, 163 to 204 and Pascal, compatible types, 165 arrays by value, 182 character dummy arguments, 189 compatible types, 164
FORTRAN calls Pascal, 168 to 185 function return values, 184, 201 incompatibilities with Pascal, 166 parameter passing, 167
Pascal calls FORTRAN, 185 to 202 interface, 163 procedures and functions as parameters, 202 to 204 records and structures, 175, 194 sharing declarations, 88 strings by value, 182 value parameters, 181, 197 var parameters, 168, 186 to 197
-fround= r option to pc command, 29
-ftrap= t option to pc command, 30 function extern option, 86, 88 external , 88 return values with C, 115, 130 return values with FORTRAN, 184,
201 type errors, 211
G
-G option to pc command, 30
–g option to pc command, 31 global variables
C and Pascal, 133
C++ and Pascal, 161 goto statement, compiler semantic error, 216
H
–H option to pc command, 31, 49 handles, XView, 226 header files for XView, 224 in a program, 70 math libraries, 233
–help option to pc command, 32
–h name option to pc command, 31
I
–I option to pc command, 32
–i option to pc command, 32
I/O errors, 212, 217
Pascal 4.0 User’s Guide
identifier errors, 208 identifiers, 33, 46, 76
IEEE support functions in math libraries, 236
%if directive, 247, 257
%ifdef directive, 255, 257, 258 illegal characters, 205
#include directive, 67
%include directive, 259, 263 include file, 84, 257 and library header files, 74 as header file, 70 introduction, 67 producing a listing of, 32 search order, 32 to break a program up, 67 incompatible type errors, 210 inline(1) procedure call expander, 40 input, 10 to 13 installation, xix interface
C++-Pascal, 137
C–Pascal, 89
FORTRAN-Pascal, 163 internationalization, 4 iropt , 40
K
-keeptmp option to pc command, 32 keyword, 33, 46
-Kpic and -KPIC options to pc command, 39
L
–L option to pc command, 33
-l option to pc command, 33, 261 language support, See internationalization ld (1) linker, 26, 34, 40
-L directory option to pc command, 33
Level 0 standard Pascal, 1, 46
Level 1 standard Pascal, 1, 46 lib object library, 34 libm functions in math libraries, 235 libm.a
math library, 234 libm.so
math library, 234
–libmieee option to pc command, 34
–libmil option to pc command, 34 libraries compiling with XView, 224 creating, 74 libsunmath support in math libraries, 242 libsunmath.a
math library, 234 licensing, 5
-noqueue option, 5 queuing, 5 status, 5
-xlicinfo option, 5 line buffering, of program output, 24 linelimit procedure, 25 linking units, 69
%list directive, 260 listing the Pascal program, 33
–l lib option to pc command, 34 locale language support, 5 logic errors, 215 lowercase characters, 33, 46
M malformed construct errors, 208 manuals, See documentation math libraries, 233 to 243 arithmetic exceptions, 239 contents, 234 function and procedure prototypes, 233
IEEE support functions, 236 libm functions, 235 libm.a
, 234 libm.so
, 234 libsunmath support, 242 libsunmath.a
, 234
Index 301
302 matherr() exception-handling function, 240
Pascal header files, 233
SPARC libraries, 238 memory, out of, 217
–misalign option to pc command, 34 module heading, 76 source files, 75 unit, 69
–mt option to pc command, 34 mv command, 9
N
–native option to pc command, 35
-nocx option to pc command, 35
–nolib option to pc command, 35
–nolibmil option to pc command, 35
%nolist directive, 262 nonstandard floating point, 29
-noqueue licensing option, 5, 35
Notifier, XView, 222
-notrace option to pc command, 36
O
–O option to pc command, 36
–o option to pc command, 9, 38 object code optimizer, 36 object file, 18 operating environment, See Solaris 2.x
operating system operator and , 38 or , 38 redirection ( > ), 11 options order of processing, 23 to pc command, 23 to 66 order of processing, options, 23 out of memory error, 217 output, 10 to 13
P
–P option to pc command, 36, 38
–p option to pc command, 39 panics, compiler, 217 parameter passing
C and Pascal, 93
C++ and Pascal, 152
FORTRAN and Pascal, 167 parameters as pointers to procedures with C, 131 passed by address, 94, 168, 186, 197 passed by reference, 94, 168, 186, 197 passed by reference between C and
Pascal, 117 to 128 passed by value between Pascal and C, 129 to 130 between Pascal and C++, 152 between Pascal and
FORTRAN, 180, 197 to
202 value conformant array, 101, 114, 123,
193 value conformant array passed between Pascal and
FORTRAN, 182 var , 95, 117 to 128, 168, 186 to 197
Pascal program how to compile, 8, 13 how to list, 33 how to run, 9 to 13 how to write, 7 pc command, 2, 7, 8, 11, 17 to 66
–a option, 24
–B option, 24
–b option, 25
-bsdmalloc option, 25
–C option, 25
–c option, 26
-calign option, 26
–cg89 option, 26
–cg92 option, 26
–cond option, 27, 249
–config option, 27, 246, 252, 256
–D option, 27
Pascal 4.0 User’s Guide
Index
–dalign option, 28
–dn option, 28
–dryrun option, 28
–dy option, 28
–fast option, 28
-flags option, 32
–fnonstd option, 29
-fns option, 29
-fround= r option, 29
-ftrap= t option, 30
-G option, 30
–G option, 30
–g option, 31
–H option, 31, 49
–help option, 32
–h name option, 31
–I option, 32
–i option, 32
-keeptmp option, 32
-Kpic and -KPIC options, 39
–L option, 33
–l option, 33, 261
-L directory option, 33
–libmieee option, 34
–libmil option, 34 list of options, 23 to 66
-l lib option, 34
–misalign option, 34
–mt option, 34
–native option, 35
-nocx option, 35
–nolib option, 35
–nolibmil option, 35
-noqueue option, 35
-notrace option, 36
–O option, 36
–o option, 9, 38
–P option, 36, 38
–p option, 39
–pg option, 39
–PIC option, 39
–pic option, 39
–Qoption , 40
-qp option, 40
–Qpath option, 40
–Qproduce option, 40
-R option, 41
–R path option, 41
–Rw option, 41
–S option, 46
-s option, 46
-s0 and –s1 options, 49
–sb option, 46
–sbfast option, 46
-tc option, 47
–temp option, 47
–time option, 48
–U option, 49
–V option, 17
–v option, 49
–VO and –V1 options, 49
–w option, 49
–xarch= a option, 49
–xcache= c option, 53
–xchip= c option, 54
–xF option, 55
–xildoff option, 56
–xildon option, 56
–xl option, 56, 245
–xlibmopt option, 57
–xlicinfo option, 57
–xMerge option, 57
–xnolibmopt option, 57
-xregs= r option, 60
-xs option, 61
-xsafe=mem option, 61
-xspace option, 62
–xtarget= t option, 62
–Z option, 66
–ztext option, 66 pc0 , 18, 40 pc3 , 18, 40
–pg option to pc command, 39
-PIC option to pc command, 39
-pic option to pc command, 39 pointer range checking, 31 preprocessor, 32 cpp (1), 27, 40 cppas , 27, 40 private variable, 73, 80
303
304 procedure and function type errors, 211 extern option, 86, 88 external , 88 linelimit , 25 type errors, 211 write , 46 program breakup of a, 67 logic errors, 215 source files, 75 unit, 68 programming object-oriented, 222 procedure-oriented, 222 public variable, 73, 80
Q
–Qoption to pc command, 40
-qp option to pc command, 40
–Qpath option to pc command, 40
–Qproduce option to pc command, 40 queuing for a license, 5
QUIT errors, 209
R
-R option to pc command, 41 range check on pointers, 31 reading and writing scalars, errors in, 212 real numbers, errors, 206 records, variant, 108, 125, 195 redirecting input and output, 11 to 13 reference parameters, 94, 117, 128, 169 replacements in the case of errors, 207
–R path option to pc command, 41 running a Pascal program, 9 to 13 runtime errors, 217 to 220
–Rw option to pc command, 41
S
–S option to pc command, 46
-s option to pc command, 46
-s0 and -s1 options, 49
–sb option to pc command, 46
–sbfast option to pc command, 46 scalar errors, 211
Selection Service, XView, 222 semantic errors, 210 separate compilation, 75 to 88 define variable, 76 extern variable, 76 module source files, 76 program source files, 76 separately compiled units, 68 set types, 93, 110, 167, 179 shared libraries, 24 sharing routines among units, 76 to 88 variables among units, 71 to 73, 76 to
86 variables and routines across multiple units using define variable, 82 using extern variable, 86 using include files, 78, 84 using public var declarations, 80 with –xl , 80 without –xl , 77 shortreal , 154, 182 sizes of types, 165
%slibrary directive, 263 source code, 40 file, 38
SPARC math libraries, 238 standard input file, 10 output file, 10
Pascal, Level 0 and 1, 1, 46 statement
Pascal 4.0 User’s Guide
#define , 27 assert , 25 stdin , 10 stdout , 10 string errors, 206 symbol errors, 208 table for dbx , 61 syntax errors and recovery, 205 to 207
T
-tc option to pc command, 47 tcov (1) utility, 24
–temp option to pc command, 47 text editor textedit , 3 vi , 3
–time option to pc command, 48 type equivalence, errors, 214 shortreal , 154, 182 sizes, See sizes of types types compatible in C and Pascal, 90 compatible in C++ and Pascal, 138 compatible in FORTRAN and
Pascal, 165 enumerated, 92, 166 incompatible, 210 set, 93, 110, 167, 179
U
–U option to pc command, 49 uninitialized variable error, 216 units compiling and linking, 69 introductory information, 67 to 73 separately compiled, 68 sharing routines, 76 to 88 sharing variables, 71 to 73, 76 to 86 unreachable statements, errors, 215 unused item errors, 216 uppercase characters, 33, 46
/usr/include , 32
V
-V option to pc command, 17
–v option to pc command, 49 value conformant array parameters, 101,
114, 123, 182, 193 value parameters with C, 129, 130 with C++, 152 with FORTRAN, 181, 197
%var directive, 247, 258, 263 variable conditional, 27, 246 define , 82 initialization of and errors, 216 parameters, 94 with C, 117, 128 with C++, 161 with FORTRAN, 168 private , 73, 80 public , 73, 80 variables and routines, sharing across multiple units using define variable, 82 using define declaration, 83 using extern variable, 86 using include files, 78, 84 using public var declarations, 80 without –xl , 77 variant records, 108, 125, 195 vi text editor, 3
–VO and –V1 options to pc command, 49
W
–w option to pc command, 49
%warning directive, 263 warning diagnostic, 49
Window Manager, XView, 222 write procedure, 46
Index 305
306 writing a Pascal program, 7 writing scalars, errors in, 212
X
–xarch= a option to pc command, 49
–xcache= a option to pc command, 53
–xchip= c option to pc command, 54
–xF option to pc command, 55
–xildoff option to pc command, 56
–xildon option to pc command, 56
–xl option to pc command, 56, 245
–xlibmopt option to pc command, 57
-xlicinfo licensing option, 5
–xlicinfo option to pc command, 57
–xMerge option to pc command, 57
–xnolibmopt option to pc command, 57
-xregs= r option to pc command, 60
-xs option to pc command, 61
-xsafe=mem option to pc command, 61
-xspace option to pc command, 62
–xtarget= t option to pc command, 62
XView attributes, 224 data types, 226 documentation, 221 handles, 226 header files, 224 introduction, 3
Notifier, 222
Selection Service, 222
Window Manager, 222
Z
–Z option to pc command, 66
–ztext option to pc command, 66
Pascal 4.0 User’s Guide
Index 307
Copyright 1995 Sun Microsystems, Inc., 2550 Garcia Avenue, Mountain View, Californie 94043-1100 U.S.A.
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