Pascal

Pascal Programming Guide
Document Number 007-0740-030

Contributors
Written by David Graves
Edited by Janiece Carrico
Production by Laura Cooper
Engineering contributions by David Ciemiewicz, Mike Fong, Ken Harris, Mark Libby,
Claudia Lukas, Andrew Myers, Jim Terhorst, and Bill Johson
© Copyright 1991-93, Silicon Graphics, Inc.— All Rights Reserved
This document contains proprietary and conﬁdential information of Silicon Graphics,
Inc. The contents of this document may not be disclosed to third parties, copied, or
duplicated in any form, in whole or in part, without the prior written permission of
Silicon Graphics, Inc.
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in Technical Data and Computer Software clause at DFARS 52.227-7013 and/or in
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Unpublished rights are reserved under the Copyright Laws of the United States.
Contractor/manufacturer is Silicon Graphics, Inc., 2011 N. Shoreline Blvd., Mountain
View, CA 94039-7311.
Pascal Programming Guide
Document Number 007-0740-030
Mountain View, California
Silicon Graphics and IRIS are registered trademarks and POWER Fortran Accelerator,
IRIS-4D, and IRIX are trademarks of Silicon Graphics, Inc. UNIX is a registered
trademark of UNIX System Laboratories. VMS and VAX are trademarks of Digital
Equipment Corporation.

iii
Contents
Introduction................................................................................................ xiii
Organization ................................................................................. xiii
Pascal Programming Environment ............................................xiv
Programming Procedure..............................................................xiv
Related Documentation.................................................................xv
Notation and Syntax Conventions...............................................xv
1. Pascal Implementation.............................................................................1-1
1.1 Names .............................................................................................1-2
1.1.1 Use of Underscores .....................................................1-2
1.1.2 Lowercase in Public Names.......................................1-2
1.1.3 Alphabetic Labels........................................................1-2
1.2 Constants........................................................................................1-3
1.2.1 Non-Decimal Number Constants .............................1-3
1.2.2 String Padding.............................................................1-4
1.2.3 Non-Graphic Characters ............................................1-4
1.2.4 Constant Expressions .................................................1-6

iv
1.3 Statement Extensions....................................................................1-8
1.3.1 Ranges in Case Statement Constants .......................1-8
1.3.2 Otherwise Clause in Case Statement........................1-8
1.3.3 Return Statement.........................................................1-8
1.3.4 Continue Statement ....................................................1-9
1.3.5 Next Statement ............................................................1-9
1.3.6 Break Statement...........................................................1-9
1.3.7 Exit Statement..............................................................1-9
1.4 Declaration Extensions...............................................................1-10
1.4.1 Separate Compilation ...............................................1-10
1.4.2 Shared Variables........................................................1-12
1.4.3 Initialization Clauses ................................................1-13
1.4.4 Relax Declaration Ordering.....................................1-14
1.4.5 Internal and Extern ...................................................1-14
1.4.6 Function Return Types.............................................1-14
1.5 Predefined Procedures ...............................................................1-15
1.5.1 Assert ..........................................................................1-15
1.5.2 Argv ............................................................................1-15
1.5.3 Date .............................................................................1-15
1.5.4 Time.............................................................................1-16
1.6 Predefined Functions..................................................................1-16
1.6.1 Type Functions ..........................................................1-16
1.6.2 Min ..............................................................................1-17
1.6.3 Max..............................................................................1-17
1.6.4 Lbound........................................................................1-17
1.6.5 Hbound.......................................................................1-17
1.6.6 First..............................................................................1-18
1.6.7 Last ..............................................................................1-18
1.6.8 Sizeof...........................................................................1-18
1.6.9 Argc.............................................................................1-18
1.6.10 Bitand..........................................................................1-19
1.6.11 Bitor.............................................................................1-19
1.6.12 Bitxor...........................................................................1-19
1.6.13 Bitnot...........................................................................1-19

v
1.6.14 Clock ...........................................................................1-19
1.6.15 Lshift ...........................................................................1-20
1.6.16 Rshift ...........................................................................1-20
1.6.17 Firstof ..........................................................................1-20
1.6.18 Lastof...........................................................................1-20
1.6.19 Addr............................................................................1-20
1.6.20 Bitsize..........................................................................1-20
1.7 I/O Extensions.............................................................................1-21
1.7.1 Specifying Radix in the Write Statement...............1-21
1.7.2 Filename on Rewrite and Reset...............................1-21
1.7.3 Reading Character Strings .......................................1-21
1.7.4 Reading and Writing Enumeration Types ............1-22
1.7.5 Lazy I/O.....................................................................1-23
1.7.6 Standard Error...........................................................1-23
1.8 Predefined Data Type Extensions.............................................1-24
1.8.1 Cardinal ......................................................................1-24
1.8.2 Double.........................................................................1-24
1.8.3 Pointer.........................................................................1-24
1.8.4 String...........................................................................1-25
1.8.5 INTEGER16................................................................1-25
1.8.6 IINTEGER32...............................................................1-25
1.9 Predefined Data Type Attributes..............................................1-26
1.9.1 static ............................................................................1-26
1.9.2 volatile ........................................................................1-26
1.9.3 Static Arrays...............................................................1-27
1.9.4 Static Variables of Type Record ..............................1-27
1.9.5 Packed Records..........................................................1-27
1.10 Parameter Extensions .................................................................1-28
1.10.1 Univ.............................................................................1-28
1.10.2 Conformant Array Parameters................................1-28
1.10.3 In, Out, and In Out....................................................1-28

vi
1.11 Compiler Notes ...........................................................................1-29
1.11.1 Macro Preprocessor ..................................................1-29
1.11.2 Short Circuiting .........................................................1-30
1.11.3 Translation Limits .....................................................1-30
1.11.4 The –apc Option ........................................................1-30
1.11.5 The –casesense Option .............................................1-32
2. Compiling, Linking, and Running Pascal Programs........................2-1
2.1 Compiling and Linking Programs..............................................2-1
2.1.1 The Pascal Driver ........................................................2-2
2.1.2 Pascal Driver Options.................................................2-3
2.1.3 Compiling Multi-Language Programs.....................2-5
2.1.4 Linking Separate Language Objects.........................2-6
2.1.5 Making Inter-Language Calls....................................2-7
2.2 Running Programs........................................................................2-7
3. Storage Mapping........................................................................................3-1
3.1 Arrays, Records, and Variant Records.......................................3-1
3.1.1 Arrays ...........................................................................3-1
3.1.2 Records .........................................................................3-2
3.1.3 Variant Records...........................................................3-4
3.2 Ranges.............................................................................................3-5
3.2.1 Ranges in a Packed Record........................................3-5
3.2.2 Ranges in an Unpacked Record ................................3-5
3.2.3 Non-Ranges Following Ranges in Unpacked
Records .........................................................................3-6
3.2.4 Non-Range Elements in a Packed Record ...............3-7
3.3 Alignment, Size, and Value by Data Type ................................3-8
3.3.1 Set Sizing for Unpacked Records..............................3-9
3.3.2 Set Sizing for Packed Arrays by Type....................3-10
3.3.3 Packed Record Alignment .......................................3-11
3.4 Rules for Set Sizes........................................................................3-12

vii
4. Pascal/C Interface......................................................................................4-1
4.1 Guidelines for Using the Interface..............................................4-2
4.1.1 Single-precision Floating Point .................................4-2
4.1.2 Procedure and Function Parameters........................4-2
4.1.3 Pascal By-Value Arrays..............................................4-3
4.1.4 File Variables................................................................4-3
4.1.5 Passing String Data Between C and Pascal .............4-3
4.1.6 Graphics Strings ..........................................................4-4
4.1.7 Passing Variable Arguments.....................................4-4
4.1.8 Passing Pointers...........................................................4-5
4.1.9 Type Checking.............................................................4-5
4.1.10 One Main Routine.......................................................4-5
4.2 Calling Pascal from C ...................................................................4-6
4.2.1 C Return Values...........................................................4-6
4.2.2 C to Pascal Arguments ...............................................4-7
4.2.3 Calling a Pascal Function from C..............................4-8
4.2.4 Calling a Pascal Procedure from C...........................4-9
4.2.5 Passing Strings to a Pascal Procedure....................4-10
4.3 Calling C from Pascal .................................................................4-11
4.3.1 Calling a C Procedure...............................................4-12
4.3.2 Calling a C Function .................................................4-13
4.3.3 Passing Arrays...........................................................4-14
A. Man Pages ..................................................................................................A-1
Index......................................................................................................Index-1

ix
Figures
Figure 1-1 External Declarations in Header File......................................1-11
Figure 1-2 Separate Compilation Unit with External
Declarations ...............................................................................1-12
Figure 2-1 Pascal Compile Process ..............................................................2-3
Figure 2-2 Multi-Language Compile Process ............................................2-6
Figure 3-1 Record in Storage, End Padded ................................................3-3
Figure 3-2 Record in Storage, Middle Padding .........................................3-4
Figure 3-3 Ranges in a Packed Record........................................................3-5
Figure 3-4 Ranges in an Unpacked Record ................................................3-6
Figure 3-5 Non-Range Elements in an Unpacked Record .......................3-7
Figure 3-6 Non-Range Elements in a Packed Record ...............................3-7

xi
Tables
Table 1-1 Escape Character Sequences........................................................1-5
Table 1-2 Constant Operators and Predefined Functions ........................1-6
Table 1-3 Maximum Limits of Data Items ................................................1-30
Table 3-1 Value Ranges by Data Type.........................................................3-8
Table 3-2 Real and Double Maximum Values............................................3-8
Table 3-3 Real and Double Minimum Values ............................................3-8
Table 3-4 Size and Alignment of Data Types in Unpacked
Records or Arrays .........................................................................3-9
Table 3-5 Size and Alignment of Pascal Packed Arrays.........................3-10
Table 3-6 Size and Alignment of Pascal Packed Records.......................3-11
Table 3-7 Set Specifications.........................................................................3-13
Table 4-1 Declaration of Return Value Types ............................................4-6
Table 4-2 C Argument Types........................................................................4-7
Table 4-3 Pascal Parameter Data Types Expected by C..........................4-11

xiii
Introduction
This guide explains how to use the Silicon Graphic Pascal compiler. Two
assumptions are made of the Pascal programmer using the IRIS programming
environment:
• You are ﬂuent in the Pascal language.
• You are comfortable with the IRIX tools that exist on the IRIS.
Organization
This guide contains the following chapters and appendices:
Chapter 1, “Pascal Implementation,” lists and describes the set of extensions
that are supported by the Pascal compiler on the IRIS. The 1.2 Pascal Release
Notes provide a detailed list of changes from the ANSI standard.
Chapter 2, “Compiling, Linking, and Running Pascal Programs,” lists speciﬁc
commands for compiling, linking, and running Pascal programs on the
IRIS-4D. It also explains the tools used in each command procedure.
Chapter 3, “Storage Mapping,” explains storage mapping of Pascal arrays,
records, and variant records. Aslo discussed are alignment, size and value
ranges for the various data types.
Chapter 4, “Pascal/C Interface,”describes how to use command line options to
optimize PFA execution. It also describes the Pascal/C coding interface. The
Fortran 77 Programmer’s Guide describes the Pascal/Fortran interface.
Appendix A, “Man Pages” is a listing of the pc(1) man page.

xiv
Pascal Programming Environment
To write Pascal graphics and other programs in the IRIS-4D programming
environment, the programmer uses these tools:
• The IRIS-4D Pascal Graphics Library
• The Pascal compiler
• The IRIX debugger dbx
Programming Procedure
Write and run your Pascal programs according to the procedure listed below.
For speciﬁc instructions about each step, refer to the chapter or document
named in that step.
1. Write programs using the Pascal implementation described in Chapter 1
of this guide.
2. Use graphics routines according to the rules in the Graphics Library
Programming Guide and the man pages for the routines.
3. Compile, link, and run the programs as described in Chapter 2 of this
guide.
4. Debug the programs using dbx.
5. Optimize the programs as described in the IRIS-4D Series Compiler Guide.
There is additional information in this manual that can be useful when you
write programs:
• Storage mapping is described in Chapter 3.
• Interfaces between Pascal and C are described in Chapter 4.
• For reference, the Pascal compiler manual page is included in
Appendix A. You can also view it online by entering man pc at your
system prompt.

xv
Related Documentation
The following documents contain information relevant to PFA:
• IRIS-4D Series Compiler Guide, Silicon Graphics, Inc., document number
007-0905-030.
Notation and Syntax Conventions
This guide uses the following notation and syntax conventions:
italic Indicates arguments in a command line that you must replace
with a valid value. In text it is used to indicate commands,
document titles, ﬁle names, glossary items, new terms, and
variables.
courier Indicates computer output and program listings.
courier bold Indicates computer input and non-printing keys.
[ ] Brackets enclose optional command arguments. Do not enter
the brackets.
. . . An ellipsis indicates that the preceding optional items can
appear more than once in succession.
( ) Parentheses enclose items. Enter them exactly as shown.
{ } Braces enclose items from which you must select exactly one.
Do not enter the braces.
| The vertical bar separates items from which you can choose
one.

Pascal Programming Guide 1-1
Chapter 1
1. Pascal Implementation
The Pascal language supported by the compiler is an implementation of ANSI
Standard Pascal (ANSI/IEEE770X3.97-1983). This implementation complies
with ANSI requirements except for the extensions. When this chapter refers to
“SGI Pascal,” it means the IRIS-4D extended implementation of Pascal.
This chapter lists and describes the set of extensions that are supported by the
Pascal compiler on the IRIS. The 1.2 Pascal Release Notes provide a detailed list
of changes from the ANSI standard.
This implementation extends the ANSI deﬁnition of Pascal to provide features
for application development, and to meet the following objectives:
• Provide extensions that make Pascal usable for a wide class of programs
• Anticipate the requirements of programmers
• Be consistent with the direction of the emerging extended standard
• Be consistent with the IRIX/C programming environment
Read Section 1.1 to learn how ANSI Pascal is extended in this implementation.

1-2 Pascal Implementation
1.1 Names
There are three extensions for names.
1.1.1 Use of Underscores
SGI Pascal allows underscores (_) in identifiers. You can use underscores to
make names that are composed of several words. You can also use an
underscore as the first character of an identifier.
This feature is consistent with the use of underscores in the C language,
making calls between SGI Pascal routines and C functions compatible.
Examples are shown below.
read_integer
_bits_per_word
1.1.2 Lowercase in Public Names
Pascal is not case-sensitive to variable names. Be aware that this causes
problems for Pascal names intended to be linked with C functions, because
case is significant in C.
SGI Pascal converts to lowercase all characters in the names of external
variables, procedures, or functions.
1.1.3 Alphabetic Labels
SGI Pascal permits alphabetic labels in addition to numeric labels as specified
by ANSI Pascal.

1.2 Constants
There are four extensions for constants.
1.2.1 Non-Decimal Number Constants
SGI Pascal allows the use of any radix from base 2 to 36.
It is often useful to write integer constants in a radix other than base 10. This
occurs in programs that use data structures defined by the system. After base
10, base 2, 8, and 16 are the most frequently used bases.
You can specify a number in these bases with this form:
base#number
where base is a decimal number in the range 2 to 36, and number is a number in
the specified radix using a..z (either case) to denote the values 10 through 25.
The number must specify a value in the range 0..maxint (2147483647). The
example below shows the number 42 as it would be written in several different
bases:
2#101010
3#1120
4#222
8#52
42
10#42
11#39
16#2a
If the radix is a power of two (2, 4, 8, 16, or 32), the number may be negative if
it specifies a 32-bit value. For example, 16#8000000 is -2147483648, which is the
smallest integer contained in a 32-bit number.

1.2.2 String Padding
SGI Pascal pads a string constant with blanks on the right according to its use.
That is, assigning a 3-character literal to a 6-character variable causes the string
literal to be treated as being 6 characters long. Assigning a 6-character literal
string to a variable containing three characters causes an error.
ANSI Pascal requires that a literal character string have the same length as the
variable with which it is used. Manually adding extra blanks invites errors,
and changing a Pascal type deﬁnition would require manually changing all
literal strings that are used with variables of that type.
1.2.3 Non-Graphic Characters
Literal character strings cannot contain ASCII characters that have no graphic
representation. Control characters are the most commonly used characters
having no graphic representation.
SGI Pascal has a special form of character string, enclosed in double quotation
marks, in which such characters may be included. A backslash ( ) escape
character is used to signal the use of a special character. For example, the
following line rings (beeps) the bell on an ASCII terminal.
writeln(output, "a")

Table 1-1, following, lists escape character sequences used to encode special
characters.
Character Result
a alert (16#07)
b backspace (16#08)
f form feed (16#0c)
n newline (16#0a)
r char (16#0d)
t horizontal tab (16#09)
v vertical feed (16#0b)
backslash (16#5c)
" quotation mark (16#22)
’ single quote (16#27)
nnn character with octal value of nnn
xnnn character with hexadecimal value of nnn.
Table 1-1 Escape Character Sequences

1.2.4 Constant Expressions
Using a constant expression in type definitions or constant definitions often
makes programs easier to read and maintain. The following example shows
one use of a constant expression. Changing a single definition (array_size)
changes both the size of the array and the definition of the index type used to
access it.
const
array_size = 100;
type
array_index = 0..array_size-1;
var
v : array[ array_index ] of integer;
SGI Pascal permits you to use a constant expression where you might
ordinarily use a single integer or scalar constant. An expression can consist of
any of the following operators and predefined functions, as shown in Table
1-2.
Operator Function
+ addition
- subtraction and unary minus
* multiplication
div integer division
mod modulo
= equality relation
<> inequality relation
< less than
<= less than or equal to
>= greater than or equal to
> greater than
() parentheses
bitand bitwise AND
Table 1-2 Constant Operators and Predefined Functions

SGI Pascal does not allow the use of a leading left parenthesis in constant
expressions for the lower value of subrange types. That is, Pascal mistakenly
assumes that:
subrange = (11+12)*13 .. 14+15;
is an enumeration instead of a subrange.
bitor bitwise OR
bitxor bitwise exclusive-OR
lshift logical left shift
rshift logical right shift
lbound low bound of array
hbound high bound of array
ﬁrst lowest value of a scalar type
last highest value of a scalar type
sizeof the size (in bytes) of a data type
abs absolute value
chr inverse ordinal value of a scalar value
ord the ordinal value of a scalar value
pred the predecessor of a scalar value
succ the successor of a scalar value
type-functions converts from one type to another
Operator Function
Table 1-2 (continued) Constant Operators and Predeﬁned Functions

1.3 Statement Extensions
There are seven statement extensions.
1.3.1 Ranges in Case Statement Constants
SGI Pascal permits the specification of value ranges in a case statement. You
can specify the selectors in a case statement using the SGI Pascal range
notation to mean all values inclusive, as in the following example.
case i of
1900..1999 : writeln(’twentieth century’);
1800..1899 : writeln(’nineteenth century’);
1700..1799 : writeln(’eighteenth century’);
1600..1699 : writeln(’seventeenth century’);
otherwise :
write(i div 100:1);
writeln(’th century’);
end
1.3.2 Otherwise Clause in Case Statement
SGI Pascal extends the case statement to allow an otherwise clause, which is the
default statement when no case clause equal to the case value exists. You can
include any number of statements between otherwise and end, as in the example
in the section above.
If no otherwise is specified, and no case clause satisfies the case selector values
during execution, a case error warning message is printed.
1.3.3 Return Statement
SGI Pascal provides a return statement that permits a procedure or function to
return to the caller without branching to the end of the procedure or function.
If used within a function, return may optionally supply a function result.
Unless this expression is specified, the last value assigned to the function name
is the function result. Using the return statement is equivalent to assigning the

value in the expression to the function name and executing a goto to the end of
a routine.
function factorial(n:integer):integer;
begin
if n = 1 then return(1)
else return(n*factorial(n-1))
end;
1.3.4 Continue Statement
The continue statement causes the flow of control to continue at the next
iteration to the nearest enclosing loop statement (for, while, or repeat). If the
statement is a for statement, the control variable is incremented and the
termination test is performed.
for J := 1 to i do begin
if Line[J] = ’ ’ then continue;
write(output, Line:J);
end (for);f1
1.3.5 Next Statement
The next statement performs the same function as the continue statement.
1.3.6 Break Statement
The break statement causes the flow of control to exit the nearest enclosing loop
statement (for, while, or repeat). This feature permits you to end a loop without
using the test specified in the loop statement.
while p <> nil do begin
if p^.flag = 0 then break;
p := p^.next
end;
1.3.7 Exit Statement
The exit statement performs the same function as the break statement.

1.4 Declaration Extensions
There are six declaration extensions.
1.4.1 Separate Compilation
SGI Pascal permits breaking a program into several compilation units: one that
contains the main program, and the others containing procedures or functions
called by the main program. (The procedures and functions it calls need not be
written in Pascal.)
SGI Pascal also permits separately compiled compilation units to share data.
The compilation unit that contains the main program (the program compilation
unit) follows ANSI Pascal syntax for a program. Only one program
compilation unit is permitted.
A compilation unit that contains separately compiled procedures and
functions is called a separate compilation unit. In a separate compilation unit,
procedure, functions, and variables are placed sequentially without any
program headers or main program block.
SGI Pascal allows Pascal declarations to be placed before the program header,
whereas ANSI Pascal does not. All procedures, functions, and variables
preceding the program header are given external scope. This means that they
may be called (as with procedures and functions) or used (as with variables)
by separate compilation units.
Figure 1-1 shows the external declarations in a program compilation unit. The
top box shows the code in the include file externs.h, and the declarations.
In this example, the external directives and other statements in the header file
externs.h specify that initialize and sum (used by the main program) and their
parameters are defined in a separate compilation unit. (The separate
compilation unit is shown Figure 1-2.)
You can use the external directive to qualify only unnested routine names.

Figure 1-1 External Declarations in Header File
Initialize and sum must be defined when the main program is link edited.
Consider the two commands below, in which the file mainone.p contains the
Pascal source code for the main program, and bodies.o contains a previously
compiled object module of initialize and sum:
pc -c mainone.p (This compiles mainone.p)
pc -o exec mainone.o bodies.o (This link edits mainone with initialize
and sum)
The external directive is similar to the Pascal forward directive, because it
declares a routine name and its parameters without defining the body of the
routine. You can use the external directive only to qualify unnested routine
names.
All procedures, functions, and variables at the outermost level have external
scope.
begin
initialize;
writeln(sum(v));
end.
const
vector_size = 100;
type
vector_index = 0..vector_size-1;
vector = array[vector_index] of integer;
var
v : vector;
procedure initialize;
external;
function sun(var vect : vector) : integer;
external;
include "externs.h"
program main(output);

Continuing with the example on the previous page, Figure 1-2 shows the
separate compilation unit in which initialize and sum are defined with the
external directive.
Figure 1-2 Separate Compilation Unit with External Declarations
Note that, in this example, the external declarations are placed in the include
file externs.h. This reduces the chance of errors due to inconsistent declarations.
Use include files this way for statements shared by multiple compilation units.
1.4.2 Shared Variables
All variables that are declared at the outermost nesting of a compilation unit
have an external scope and can be used in different compilation units.
var
i : vector_index;
begin
for i :+ lbound(vector to hbound(vector) do v[i] :+ i;
end {procedure initialize};
function sum;
var
i : vector_index;
j : integer;
begin
j := 0;
for i := lbound(vector) to hbound(vector)
do j := j+vect[i];
return (j);
end {function sum};
include "externs.h"
vector_size = 100;
type
vector_index = 0..vector_size-1;
vector = array[vector_index] of integer;
var
v : vector;
external;
function sun(var vect : vector) : integer;
external;
const

The variable can have only one initializing clause and can be placed in only
one compilation unit. Look again at the example above. It illustrates a variable
named v that is accessed from both compilation units.
1.4.3 Initialization Clauses
SGI Pascal permits an external variable to have a clause that initializes either a
scalar, a set, an array, or a pointer. The BNF syntax of the extended variable
declaration is shown below.
var-decl ::= identifier-list ":" type-denoter
[" := "initial-clause]
initial-clause ::= constant-expr |
"[" initial-value-list "]"
initial-value ::= constant-expr [".." constant-expr] |
constant-expr ":" constant-expr |
"otherwise" ":" constant-expr |
"[" initial-value-list "]"
initial-value-list ::= initial-value |
initial-value-list "," initial-value
For scalar types, this initialization is very simple:
var
a : integer := 5;
letter : char := ’x’;
x1 : real := 6.5;
An initial value may also be given to a structured type (array or set). Every
element of an array must be initialized or given a speciﬁc default value.
type
color = (red, yellow, blue);
hue = set of color;
vector = array[1..100] of integer;
var
orange : hue := [red, yellow];
white : hue :=
[first(color)..last(color);
name : packed array[1..32] of char :=
’Silicon Graphics Computer Systems’:
vect : vector :=
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9,

30 : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
otherwise : 99];
pointers : array[0..127] of ^vector := [otherwise: nil];
The above clauses initialize two sets, a string, and two arrays. All elements of
the array vect, except the first 10 elements and the 10 elements starting at index
30, are initialized to 99. The array pointers is initialized entirely to the value nil.
1.4.4 Relax Declaration Ordering
The declaration clauses described in this section can be written in any order
and may be repeated. The ANSI requirement that a declaration must precede
any use must still be observed.
1.4.5 Internal and Extern
If you declare a procedure or function with the internal attribute, the procedure
or function becomes a local rather than global symbol. If you declare a
procedure or function extern, you can define it in a separate file. In the
following example, x is internal and therefore local:
function x (num : integer) : integer ; internal;
1.4.6 Function Return Types
Functions can return scalar types, records, arrays, and sets. For example:
program main;
type
rec = record
field1 : char;
field2 : integer;
end;
var
reca : rec;
function xx : rec;
var recb : rec;
begin
recb.field1 := ’a’;
recb.field2 := 9;
xx := recb;

end;
begin
reca := xx;
end.
1.5 Predefined Procedures
There are four extensions of predefined procedures.
1.5.1 Assert
assert(boolean-expr [,string])
The assert procedure evaluates a boolean expression and signals an execution
time error (similar to a checking error) if the value is not true.
If you specify the optional string, the string is written to standard error,
otherwise, this message is generated, along with the line number and file name
of the assert statement that causes the error:
assertion error in Pascal program
1.5.2 Argv
argv(integer-expr,string-var)
The argv procedure returns the i-th program argument, placing the result in a
string. The string can be blank, padded, or truncated, as required.
The value of the first parameter must be in the range 0..argc-1. Argument 0 is
the name of the program.
1.5.3 Date
date(string-var)
The date procedure returns the current date.

The resulting string has the form yy/mm/dd, where yy is replaced with the last
two digits of the year, mm is replaced with the number of the month (January
is 01), and dd is replaced with the day of the month (the first day is 01).
If the string is less than 8 characters long, data is truncated on the right; if the
string is longer than 8 characters, the string is padded with blanks on the right.
1.5.4 Time
time(string-var)
The time procedure returns the current time. The resulting string has the form
hh:mm:ss, where hh is replaced with the hour (on the 24-hour clock), mm is
replaced with minutes (00 means on the hour), and ss is replaced with seconds
(00 means on the minute).
If the string is less than eight characters, data is truncated on the right; if the
string is longer than eight characters, the string is padded with blanks on the
right.
1.6 Predefined Functions
There are 20 predefined function extensions.
1.6.1 Type Functions
ANSI Pascal offers two predefined type functions, ord and chr, that convert
predefined scalar types.
SGI Pascal allows all scalar types to have a conversion function that converts
an integer into that scalar type. As in ANSI Pascal, the ord function converts
from the scalar type to integer.
SGI Pascal lets all type identifiers for a scalar type be used in an expression to
convert its integer argument into the corresponding scalar value. Thus, if color
is an enumerated data type, color(i) is a function that returns the i-th element
of the enumeration.

boolean-var := boolean (integer-expr)
char-var := char(integer-expr)
color-var := color(integer-expr)
In Pascal, the ord function also operates on pointers, returning the machine
address of the item referenced by the pointer. A data type identifier that
represents a pointer data type can also be used to convert a cardinal number
into a valid pointer of that type. This feature is highly machine-dependent and
should be used sparingly.
1.6.2 Min
scalar-var := min(scalar-expr[,scalar-exp]...)
The min function returns the smallest of its scalar arguments. For example,
min(-6, 3, 5) returns -6.
1.6.3 Max
scalar-var := max(scalar-expr[,scalar-expr]...)
The max function returns the largest of its scalar arguments. For example,
max(-2, 3, 5) returns 5.
1.6.4 Lbound
scalar-var := lbound(array-type[,index])
The lbound function returns the lower bound of the array type specified by the
first argument. The array type must be specified by a type identifier or a
variable whose type is array. If the array is multi-dimensional, then an optional
second argument specifies the dimension. The default is 1, which specifies the
first or outermost dimension.
1.6.5 Hbound
scalar-var := hbound(array-type[,index])

The hbound function returns the upper bound of the array type specified by the
first argument. The array type must be specified by a type identifier or a
variable whose type is array. If the array is multi-dimensional, then an optional
second argument specifies the dimension. The default is 1, which specifies the
first or outermost dimension.
1.6.6 First
scalar-var := first(type-identifier)
The first function returns the first (lowest) value of the named scalar type. For
example, first(integer) returns -2147483848.
You can use first to find the bottom end of a range, or other scalar data type.
Scalar types include integers, ranges, boolean, characters and enumerations.
1.6.7 Last
scalar-var := last(type-identifier)
The last function returns the last (highest) value of the named scalar type. For
example, last(integer) returns 2147483847 (maxint). Use it to find the top end of
a range.
1.6.8 Sizeof
sizeof(type-id[,tagfield-value]...)
The sizeof function returns the number of bytes occupied by the data type
specified as an argument. If the argument specifies a record with a variant
record part, then additional arguments specify the value of each tagfield.

1.6.9 Argc
integer-var := argc
The argc function returns the number of arguments passed to the program. The
value of the function is 1 or greater.
1.6.10 Bitand
integer-var := bitand(integer-expr, integer-expr)
The bitand function returns the bitwise AND of the two integer-valued
operands.
1.6.11 Bitor
integer-var := bitor(integer-expr, integer-expr)
The bitor function returns the bitwise OR of the two integer-valued operands.
1.6.12 Bitxor
integer-var := bitxor(integer-expr,integer-expr)
The bitxor function returns the bitwise exclusive-OR of the two integer-valued
operands.
1.6.13 Bitnot
integer-var := bitnot(integer-expr, integer-expr)
The bitnot function returns the bitwise NOT of the two integer-valued
operands.

1.6.14 Clock
integer-var := clockf1
The clock function returns the number of milliseconds of processor time used
by the current process.
1.6.15 Lshift
integer-var := lshift(integer-expr, integer-expr)
The lshift function returns the left shift of the first integer-valued operand by
the amount specified in the second argument. Zeros are inserted on the right.
1.6.16 Rshift
integer-var := rshift(integer-expr, integer-expr)
The rshift function returns the right shift of the first integer-valued operand by
the amount specified in the second argument. Sign bits are inserted on the left
if the operand is an integer type; zero bits are inserted if the operand is a
cardinal type. You can force zero bits with the following construct:
rshift(cardinal(intexpr), shiftamount)
1.6.17 Firstof
The firstof function is equivalent to the first function.
1.6.18 Lastof
The lastof function is equivalent to the last function.

1.6.19 Addr
The addr function returns a pointer to the variable or function argument. The
argument can be a string constant but cannot be another other type of constant.
The argument can not be a nested or internal procedure, or a variable.
1.6.20 Bitsize
The bitsize function returns the size in bits of the data type indicated by the
argument.
1.7 I/O Extensions
There are six I/O extensions.
1.7.1 Specifying Radix in the Write Statement
Pascal permits the specification of operands in a write statement that writes
numbers in any radix from 2 through 36. The following code writes a number
in each radix:
for i := 2 to 36 do
writeln(’x is’,x:1:i,’ in radix’,i:1);
A minus sign precedes any printed number if the type of the number is integer
and the value is less than zero. If the type of the number is cardinal, then the
compiler interprets the number as not having a sign and prints the sign bit as
part of the number (rather than with a negative sign).
1.7.2 Filename on Rewrite and Reset
SGI Pascal accepts an optional string argument that specifies the path name of
the file to be opened or created. Otherwise, SGI Pascal creates a temporary file
that exists only during program execution, in the directory /tmp.
reset(inputfile [,string])
rewrite(outputfile [,string])

1.7.3 Reading Character Strings
SGI Pascal allows you to read characters into a character string array, while
ANSI Pascal does not. A string is defined to be a packed array of char whose
lower bond is 1 and whose upper bond is greater than 1.
In the following example, characters are read into the array one line at a time
until the end-of-file (eof) is reached.
program CountLines(input, output);
type
string80 = packed array[1..80] of char;
var
Line : string80;
begin
.
.
while not eof(input) do begin
readln(input, Line)
i := i+1;
end; {while}
write (’The number of lines is ’, I:1);f1
1.7.4 Reading and Writing Enumeration Types
SGI Pascal provides an extension to permit any enumerated scalar type to be
specified as the operand of a read or a write to a text file.
Reading an enumeration value interprets the programmer-defined name,
preceded optionally by blank, tab, or new-line characters. The end of the name
is delimited by any character that is not a valid character of an identifier. The
delimiting character is skipped. Good choices for delimiting characters are
blanks, tabs, commas, or new-lines.
Writing an enumerated value causes the programmer defined name to be
written out to the text file.

The following piece of code is an example of using enumerated values:
program testenum(input, output);
type
color = (red, orange, yellow, green, blue, violet,
black, white);
var
vcolor : color;
begin
repeat
writeln(’enter color’);
read(vcolor);
writeln(’The color is ’, vcolor : 0);
until eof;
end.
If any color other than the one specified in the color enumeration is entered, the
following message is displayed:
enumerated value string not within type
The color is red
where string represents the incorrect value entered.
When an incorrect value is entered, the first value in the enumeration (red in
the example above) is written to the screen.
1.7.5 Lazy I/O
SGI Pascal provides an extension to ANSI Pascal I/O that simplifies
terminal-oriented I/O. Standard Pascal defines the file pointer of a text file to
point to the first character of a line after a reset or readln operation. This makes
it difficult to issue a prompt message because the physical I/O operation for
the next line occurs at the end of the readln procedure.
SGI Pascal follows ANSI Pascal conventions, except that it does not perform
physical I/O until the program user actually uses the file pointer.
In effect, it is lazy about performing the I/O operation. This allows the user to
issue a prompt message after the readln (or reset) prior to the time when the
user’s terminal attempts to read the next line.

1.7.6 Standard Error
SGI Pascal provides an additional predefined text file called err, which is
mapped to IRIX standard error. Also, the files input and output are mapped to
the IRIX file standard input and standard output.
1.8 Predefined Data Type Extensions
There are six predefined data type extensions.
1.8.1 Cardinal
SGI Pascal accepts the cardinal data type that represents an unsigned integer in
the range 0..4294967295 ( 2 32
−1 ). If either operand of an expression is cardinal,
then the compiler uses unsigned arithmetic.
1.8.2 Double
SGI Pascal accepts a new predefined data type called double that represents a
double-precision floating point number. If either operand of an expression is
double, then the compiler uses double-precision.
1.8.3 Pointer
SGI Pascal defines a new predefined data type called pointer that is compatible
with any pointer type. This can be thought of as the type of the Pascal value
nil. Use pointer to write procedures and functions that accept an arbitrary
pointer type as an operand.
Note that you cannot directly de-reference a variable of this type because it is
not bound to a base type. To de-reference it, you must first assign the variable
to a normally typed pointer.

Procedure and Function Pointers
You can use the addr function to assign a value to a variable defined to be a
procedure or function pointer. This is useful in passing the address of a
procedure or function as a parameter. For example:
var proc_ptr : ^procedure (i:integer);
func_ptr : ^function (a,b:integer) : real;
1.8.4 String
This new SGI Pascal predefined array type is defined as
type string = array[1..80] of char;
1.8.5 INTEGER16
A variable defined as INTEGER16 represents a signed 16-bit integer, and
occupies a halfword.
1.8.6 INTEGER32
A variable defined as INTEGER32 represents a signed 32-bit integer, and
occupies a full word.

1.9 Predeﬁned Data Type Attributes
SGI Pascal supports two new data type attributes: static and volatile.
1.9.1 static
The compiler will allocate space for a static variable and keep the name local
to the procedure. The variable retains its value from one invocation of the
procedure to the next. In the following example, k is a static integer.
var first : boolean := true;
j : integer;
function show_static: integer;
var k : static integer;
i : integer;
begin
if first then begin
k := 9;
first := false;
end else
k := k + 3;
show_static := k;
end;
program main;
begin
for j := 1 to 2 do
writeln(’Show_Static ;+ ’,show_static:3);
end.
1.9.2 volatile
The compiler will not perform certain optimizations for a volatile variable.
This is useful for retaining pointer references that might appear to the
optimizer to be redundant.

1.9.3 Static Arrays
SGI Pascal permits you to initialize a static variable of type array (single or
multi-dimensional). For example:
type foo = (one,two);
var x : array [foo,foo] of foo := [[one,two], [two,one]];
1.9.4 Static Variables of Type Record
SGI Pascal permits you to initialize static variables of type record. For example:
type rec = record;
field1 : integer;
field2 : char;
end
var rec1 : rec := [1,’a’];
rec2 : rec := [Field2 := ’M’ ; Field1 := 3]’
1.9.5 Packed Records
In packed records, fields of subrange data types based on integers and
enumerated types are assumed by default to have word alignment. Thus, in
allocating the field, the compiler skips bits as necessary to avoid crossing a
word boundary. In extracting the field, the compiler always loads words. The
base type of a subrange can now be specified using the of keyword, as in the
following example:
i: 0..32767 of INTEGER16;
This causes the field i to have halfword alignment. Similarly,
i: 0..255 of char;
causes the field i to have the alignment of the data type char, that is, byte
alignment.

1.10 Parameter Extensions
1.10.1 Univ
The compiler will not perform type checking for a parameter with the
universal attribute Univ. The compiler will still perform size checking. For
example:
var y : real;
procedure x (j: univ integer);
…
x(y);
1.10.2 Conformant Array Parameters
Conformant array parameters allow array type parameters of functions and
procedures to have variable dimensions. You can use any array that conforms
to the parameter deﬁnition as an actual parameter. For example:
procedure print (msg : array[min..max: integer] of char);
var i : integer;
begin
for i := min to max do
write(msg[i]);
writeln;
end;
var
large : array [-10..10] of char
small : array [2..7] of char;
begin
… {Load some values into the arrays}
print(large);
print(small);
end.

1.10.3 In, Out, and In Out
These keywords specify the direction of parameter passing between routines.
Parameters declared as type in can not be changed within the scope of the
routine. Parameters declared as out are not expected to have a value when they
enter the procedure, but are expected to have a value when they leave it.
Flagging a parameter as in out tells the compiler that it contains a value and
that the procedure is permitted to modify that value.
1.11 Compiler Notes
These notes describe extensions that affect the compile process.
1.11.1 Macro Preprocessor
SGI Pascal invokes the C preprocessor (cpp) before each compilation, allowing
you to use cpp syntax in the program. The cpp variables LANGUAGE_PASCAL,
LANGUAGE_C, LANGUAGE_FORTRAN, and LANGUAGE_ASSEMBLY are
deﬁned automatically, allowing you to build header ﬁles that can be used by
different languages.
The following example shows two conditional statements, one written in
Pascal and the other written in C.
#ifdef LANGUAGE_PASCAL
type
pair =
record
high, low : integer;
end; {record}
#end
#ifdef LANGUAGE_C
typedef struct {
int high, low;
} pair
#end
You can also use the full conditional expression syntax of cpp, as well as C style
comments ( /* ...*/ ), which are stripped during compilation.

1.11.2 Short Circuiting
SGI Pascal always short circuits boolean expressions. Short circuiting is a
technique where only a portion of a boolean expression is actually executed.
For example, in this code:
if (P<>nil) and (P^.Count > 0) then
the expression involving P^.Count is not evaluated if the first expression is
false. This extension is permitted by ANSI Pascal. A program that relies on this
feature, as does this example, would not be portable.
1.11.3 Translation Limits
The following table shows the maximum limits imposed on certain items by
the Pascal compiler. Chapter 3 discusses set sizing rules in greater detail; see
Chapter 3 for more information.
1.11.4 The -apc Option
This option enables some of the Apollo Pascal extensions that are
implemented in the SGI Pascal compiler. This option must be passed to the SGI
Pascal compiler by using -Wf,-apc.
Pascal Specification Maximum
Literal string length 288
Procedure nesting levels 20
Set size 451 - 512 (see Section 3.4 for rules)
Significant characters 32
Table 1-3 Maximum Limits of Data Items

These extensions include:
• IN_RANGE: This built-in function determines whether a specified scalar
variable is within the defined range of an integer subrange or enumerated
type.
var i : -7..7;
begin
write(' enter i : ');
readln(i);
if (in_range(i)) then
....
• DISCARD: This procedure explicitly discards an expression value, which
could include a value returned by a function call.
• Non-standard MOD operator: Under this flag the MOD operator returns
a negative result when the dividend is negative.
• DEFINE: This attribute tells the compiler to allocate the variable in the
static data area and to make its name accessible externally.
var j : define integer := 9;
• EXTERN: This attribute tells the compiler not to allocate a space for the
variable since it may be allocated in a separate compiled procedure.
• infix bit operators: These bitwise operators are:
– & equivalent to BITAND
– ! equivalent to BITOR
– ~ equivalent to BITNOT
Examples:
var i,j : integer;
. . .
(i & j)
(i ! j )
(~ i)
• Type coercion: TYPE(var). Type coercions are a bitwise transfer from a
variable of one data type to a variable of another data type.
var i : integer;
x : real;
begin i := 456;
x := real(i);

The variable x now contains the same bits that i does, not the same
number value. Note that the SGI Pascal compiler currently implements
type conversion using the above syntax. Under the -apc flag the compiler
interprets this as a type coercion rather than type conversion.
• <type-id> pseudo function: SGI Pascal permits the use of the transfer
function on the left hand side of an assignment statement.
real(i) := x + y;
The above means that the assignment is done in floating point mode and
that the bits of i contain the same number as x+y.
• Constant strings may be assigned to non-packed arrays of char.
• Correctly aligned objects within a packed array are passed as VAR
parameters.
• implicit null otherwise: If no CASE is taken and OTHERWISE is left
undefined, the CASE statement has no effect and executes without an
error.
• array initialization [N of C]: This form tells the compiler to initialize N
elements of the array to the value C.
• Wild card array initialization: When initializing an array in the var part of
a routine, the compiler can compute the first dimension of the array.
var arr: array[1..*] of char := 'This is a test';
• Under the -apc flag integer is equivalent to INTEGER16 and occupies two
bytes of storage. Therefore, MAXINT = 32767.
• Real constants are permitted to be of the form “123.”
1.11.5 The -casesense Option
Assert case sensitivity on variable names. The default is case insensitive, that
is, variable names ABC and abc are considered to be the same identifier.

Chapter 2
2. Compiling, Linking, and Running Pascal Programs
This chapter lists speciﬁc commands for compiling, linking, and running
Pascal programs on the IRIS-4D. It also explains the tools used in each
command procedure.
You can ﬁnd general information about compiling, linking, and running
programs on the IRIS-4D in the IRIS-4D Series Compiler Guide.
2.1 Compiling and Linking Programs
Compile and link programs using the Pascal driver command pc as described
in this section.
This is the format of the pc command:
pc [options] filename
These are the parts of the command and their tasks:
• pc invokes the Pascal driver processes that compile, optimize, assemble,
and link edit the program. (To compile programs without linking, see
Section 2.1.2, “Pascal Driver Options” below.)
• option represents a driver option. The number of options allowed on a
command line by the compiler varies according to the task.

2-2 Compiling, Linking, and Running Pascal Programs
• filename may include Pascal source code, object code, and libraries:
– filename.p for Pascal source code
– filename.o for object code
– -l libraryname for libraries; libraries follow files
The output of the pc command is a program executable module.
2.1.1 The Pascal Driver
The Pascal driver invoked by the pc command is an intelligent program that in
turn invokes the five major components of the compiler system.
These are the five components, listed below in processing order:
1. Pascal compiler
2. optimizer
3. code generator
4. assembler
5. link editor
Figure 2-1 illustrates the compile process.
In this illustration, the primary driver phases are in the boxes. The principal
input is the source file more.p. The principal output is the executable file a.out.
The file name a.out is the default name for executables.
See Section 2.1.2 section below to rename the executable file during the
compile process.

Figure 2-1 Pascal Compile Process
2.1.2 Pascal Driver Options
Three driver output options are listed in this section according to the task each
one performs. Additional options are discussed briefly by category. The
complete set of options is listed in reference format in the pc(1) man page.
Produce a Linkable Object File
Use the --c driver option to produce a linkable object file instead of an
executable. This option stops the driver immediately after the assembler
phase.
The linkable object file has the suffix .o.
Here is an example of the driver command with this option:
pc -c more.p
Pascal Front End
Optimizer
Code Generator
Assembler
Link Editor
(optional)
more.p
more.o
a.out

The object file produced is more.o.
Note: When you want to place more than one object file on the command
line, specify the file containing the main program first. The link editor
requires this information.
Rename the Executable
Use the -o option to rename the executable during the compile process. If this
option is not used, the executable will be named a.out.
You can use this option with a source file or an object module.
Here is an example command line that takes the source file myprog.p, compiles
it, links it, and names the executable exec.myprog:
pc myprog.p -o exec.myprog
Here is an example command that takes the object module more.o, links it, and
names the executable exec.myprog:
pc more.o -o exec.myprog
Graphics Option
If your program contains graphics routines from the Graphics Library, you
need to use the graphics option. The graphics option, -Zg, automatically links
to your program two libraries and a conversion file: libpgl.a, libgl.a, and
p2cstr.o.
If you do not use the -Zg option, you can explicitly link the necessary routines
as follows:
pc sourcefile.p -lpgl -lgl /usr/lib/p2cstr.o
Debugging Options
When you are debugging, use the -g option with the output option discussed
above. The -g option creates an expanded symbol table in the object file and
links the file using the debugging flag. An example of compiling for
debugging is:
pc -g sourcefile.p -o executefile

There are other forms of the -g option, plus different options for profiling (-pn),
optimizing (-On), and other specialized driver functions. These are discussed
and listed in the release notes for your version of Pascal.
2.1.3 Compiling Multi-Language Programs
The compiler system provides drivers for other languages in addition to
Pascal, including C (standard), Fortran 77 (optional), and PL/1 (optional).
This section describes general multi-language compiling conventions.
When your application has two or more source programs written in different
languages, you should compile each program separately with the appropriate
driver, and then separately link them in another step. Use the -c option to
create objects suitable for link editing.
Driver Command Syntax
For each language below, see the man page listed with it for correct driver
command syntax:
C cc(1)
Fortran 77 f77(1)
PL/1 pl1(1)
Pascal pc(1)
Here is a command example with a C program and a Pascal program:
cc -c main.c
pc -c rest.p
main.c contains the main routine and is executed first, as required. Then the
Pascal source file rest.p is compiled.
The compile processes and output for this example are shown in Figure 2-2.

Figure 2-2 Multi-Language Compile Process
2.1.4 Linking Separate Language Objects
The driver recognizes the .o sufﬁx as the name of a ﬁle containing object code
suitable for link editing, and immediately invokes the link editor.
Here is an example command that link edits the object created in the last
example above:
pc -o all main.o rest.o
The command produces the executable program object all. You can achieve the
same results using the cc driver command with the additional option -l, as
shown below:
cc -o all main.o rest.o -lp -lm
Both f77 and cc use the C link library by default. However, the cc driver
command does not know the names of the link libraries required by Pascal
C Front End
Code Generator
Assembler
main.c
main.o
Pascal Front End
Code Generator
Assembler
rest.p
rest.o

objects. Therefore, you must specify them explicitly to the link editor, using the
-l option with the symbols for the other libraries.
The -l option with p links the Pascal library /usr/lib/libp.a.
The -l option with m links the Math library /usr/lib/libm.a.
See the FILES section of the Pascal pc(1) manual pages, for a complete list of
ﬁles available. See the ld man page for additional information about the -l
option.
2.1.5 Making Inter-Language Calls
In addition to compiling separate language source ﬁles into one executable,
you can make inter-language calls between C, Pascal, and Fortran 77.
An interface between C and Pascal is described in Chapter 4 of this manual. An
interface between Pascal and Fortran 77 is described in the Fortran 77
Programmer’s Guide.
2.2 Running Programs
Run Pascal programs using the name of the executable object module
produced by the pc command with the -o option.
If you do not rename the program during the compile process, it is named a.out
by default. Invoke it with this command in the directory where the executable
resides:
a.out
If you do rename the program during the compile process, invoke it with its
assigned name in the directory where the executable resides.
The IRIS-4D Series Compiler Guide contains more information about run time
considerations.

Chapter 3
3. Storage Mapping
Storage mapping of Pascal arrays, records, and variant records is described in
the first part of this chapter. Ranges are discussed in the second part.
Alignment, size and value ranges for the various data types are described in
the third part. The last section discusses rules for set sizing.
3.1 Arrays, Records, and Variant Records
Pascal maps arrays and records into storage like C maps arrays and structures.
3.1.1 Arrays
An array has the same boundary requirements as the data type specified for
the array. The size of an array is the size of the data type, multiplied by the
number of elements.
For example, for the following declaration,
x : array [1..2, 1..3] of double;
the size of the resulting array is 48 bytes (2*3*8, where 8 is the size of the
double-floating point type in bytes).

3-2 Storage Mapping
3.1.2 Records
Each member of a record begins at an offset from the record base. The offset
corresponds to the order in which a member is declared; the ﬁrst member is at
offset 0.
The size of a record in the object ﬁle is the size of its combined members plus
padding added, where necessary, by the compiler.
The following rules apply to records:
• Records must align on the same boundary as that required by the
member with the most restrictive boundary requirement. These are the
boundary requirements, listed by increasing degree of restrictiveness:
– byte
– halfword
– doubleword
• The compiler terminates the record on the same alignment boundary on
which it begins. For example, if a record begins on an even-byte
boundary, it also ends on an even-byte boundary.
Example: Record
This example shows a record in code:
type S = record
v : integer;
n : array [1..10] of char;
end;
Figure 3-1 shows how it is mapped in storage.

Figure 3-1 Record in Storage, End Padded
Note that the length of the record is 16 bytes, even though the byte count as
deﬁned by the v:integer and the n:array[1..10] of char components is only 14.
Because integer has a stricter boundary requirement (word boundary) than
char (byte boundary), the record must end on a word boundary (a byte offset
divisible by four). The compiler therefore adds two bytes of padding to meet
this requirement.
An array of data records illustrates the reason for this requirement. For
example, if the above record were the element-type of an array, some of the
v:integer components would not be aligned properly without the two-byte pad.
Example: Record with Different Alignment
This example shows a record with different alignment in code:
type S = record
n : packed array [1..10] of char;
v : integer;
end;
VVVV n[1] n[2] n[3] n[4]
n[5] n[6] n[7] n[8] n[9] n[10]
Byte 0 1 2 3 4 5 6 7
Byte 8 9 10 11 12 13 14 15
Padded bytes

3-4 Storage Mapping
Figure 3-2 Record in Storage, Middle Padding
In the example, the alignment requirements cause padding to appear in the
middle of the record. Note that the size of the record remains 16 bytes, but two
bytes of padding follow the n component to align v on a word boundary.
3.1.3 Variant Records
A variant record must align on the same boundary as the member with the
most restrictive boundary requirement.
These are the boundary requirements, listed by increasing degree of
restrictiveness:
• byte
• halfword
• word
• doubleword
For example, a variant record containing integer, char, and double data types
must align on a doubleword boundary, as required by the double data type.
VVVV
n[1] n[2] n[3] n[4] n[5] n[6] n[7] n[8]
n[9] n[10]
Byte 0 1 2 3 4 5 6 7
Byte 8 9 10 11 12 13 14 15
Padded bytes

3.2 Ranges
Ranges in a packed record are packed from the most-significant bit to the
least-significant bit in a word.
3.2.1 Ranges in a Packed Record
This example shows a packed record in code:
type virtual_address = packed record
offset : 0..4095; (* 12 bits *)
page : 0..1023; (* 10 bits *)
segment : 0..511; (* 9 bits *)
supervisor : 0..1; (* 1 bit *)
end;
Figure 3-3 Ranges in a Packed Record
3.2.2 Ranges in an Unpacked Record
Ranges in an unpacked record are packed from the most-significant bit to the
least-significant bit, but each range is aligned to the appropriate boundary.
This example shows an unpacked record in code:
type virtual_address = record
offset : 0..4095; (* 12 bits *)
page : 0..1023; (* 10 bits *)
segment : 0..511; (* 9 bits *)
supervisor : 0..1; (* 1 bit *)
end;
offset page segment
Bit
Byte 0 1 2 3 4 5 6 7
31 20 19 9 8 1 0
supervisor

3-6 Storage Mapping
Figure 3-4 Ranges in an Unpacked Record
3.2.3 Non-Ranges Following Ranges in Unpacked Records
For unpacked records, the compiler aligns a non-range element that follows a
range declaration to the next boundary appropriate for its type.
This example shows another unpacked record in code:
var x : record
a : 0..7; (* 3 bits packed *)
b : char; (* 8 bits *)
c : -32768..32767; (* 16 bits *)
end;
offset page
Bit
Byte 0 1 2 3 4 5 6 7
supervisor
segment
Bit
Byte 0 1 2 3 4 5 6 7
31 19 16 15 6 5 0
63 54 53 484746 32
Padded bytes

Figure 3-5 Non-Range Elements in an Unpacked Record
3.2.4 Non-Range Elements in a Packed Record
For a packed record, the computer bit-aligns booleans, chars, and ranges. All
other types are word or double-word aligned as appropriate for the type. This
example shows the same code as above in a packed record and its mapping in
storage:
var x : packed record
a : 0..7; (* 3 bits *)
b : char; (* 8 bits *)
c : -32768..32767 (* 16 bits *)
end;
Figure 3-6 Non-Range Elements in a Packed Record
31 29 28 24 23 17 16 0Bit
Byte 0 1 2 3 4 5 6 7
a b c
Padded bytes
Bit
Byte 0 1 2 3 4 5 6 7
a b c
Padded bytes
31 29 28 2120 5 4 0

3-8 Storage Mapping
3.3 Alignment, Size, and Value by Data Type
This section describes how the Pascal compiler implements size, alignment,
and value ranges for the various data types.
Table 3-1 shows the value ranges for the Pascal scalar types.
Note: See Table 3-2 and Table 3-3 for more data.
Table 3-2 and Table 3-3 show the approximate valid ranges for real and double.
Enumerated types with n elements are treated in the same manner as the
integer subrange 0..n-1.
Scalar Type Value Ranges
boolean 0 or 1
char 0..127
integer -231
..231
-1
cardinal 0..232
-1
real See Note
double See Note
Table 3-1 Value Ranges by Data Type
Type Maximum Value
real 3.40282356*1038
double 1.7976931348623158*10308
Table 3-2 Real and Double Maximum Values
Minimum Value
Type Denormalized Normalized
real 1.40129846 * 10-46
1.17 549429 * 10-38
double 4.9406564584124654*10-324
2.2250738585072012*10-308
Table 3-3 Real and Double Minimum Values

3.3.1 Set Sizing for Unpacked Records
Table 3-4, following, lists size and alignment parameters for unpacked records.
See Section 3.4, “Rules for Set Sizes,” for rules about specifying the upper and
lower bounds of sets.
Note: For unpacked records, the compiler uses the following formula for
determining the size of the set of a..b:
size=[b2 − a/32 + 1 words
The notation [ x ] indicates the floor of x, which is the largest
integer not greater than x.
Unpacked Records or Arrays (variables or fields)
Type Size Alignment
boolean 8 byte
char 8 byte
integer 32 word
cardinal 32 word
pointer 32 word
file 32 word
real 32 word
double 64 doubleword
subrange of:
0..255 or -128..127 8 byte
0..65535 or -32768..32767 16 halfword
0..232
- 1
-231..-231
- 1 32 word
set of char 128 word
set of a..b See note word
Table 3-4 Size and Alignment of Data Types in Unpacked Records or Arrays

3-10 Storage Mapping
3.3.2 Set Sizing for Packed Arrays by Type
The compiler uses the rules shown in Table 3-5 for aligning packed arrays.
Note: For packed arrays, the compiler uses the minimum number of bits
possible in creating the set of a..b.
Packed Arrays
Scalar Type Size Alignment
boolean 8 byte
char 8 byte
integer 32 word
cardinal 32 word
pointer 32 word
ﬁle 32 word
real 32 word
subrange of:
0..1 or -1..0 1 bit
0..3 or -2..1 2 2-bit
0..15 or -8..7 4 4-bit
0..255 or -128..127 8 byte
0..65535 or -32768..32767 16 halfword
0..232
- 1
-231..-231
- 1 32 word
set of char 128 word
set of a..b See note
Table 3-5 Size and Alignment of Pascal Packed Arrays

The following formula is used:
If
(b − 32 a/32+1)≤32
then
size = b −32a/32 + 1 bits
else
size = b/32−a/32+1words
Note that the set of a..b is aligned on an n-bit boundary where n is a power of 2.
The value of n is computed as follows:
n = 2log2(size)
For example, the set of 0..2 has a size of 3 bits as computed above and will align
on a 4-bit boundary.
See Section 3.4 at the end of this chapter for rules about specifying the upper
and lower bounds of sets.
3.3.3 Packed Record Alignment
The compiler uses the rules shown in Table 3-6 for aligning packed records.
Packed Arrays
Scalar Type Size Alignment
boolean 8 byte
char 8 byte
integer 32 word
cardinal 32 word
pointer 32 word
ﬁle 32 word
real 32 word
subrange of a..b See note bit/word
Table 3-6 Size and Alignment of Pascal Packed Records

3-12 Storage Mapping
Note: For packed records, the compiler uses the minimum number of bits
possible in creating a subrange field.
For the subrange a..b, this formula is used:
If a >= 0 then size = log2(b + 1)  bits
If a > 0 then size = max(log2(b + 1),log2(-a ) )+1 bits
The notation  x  indicates the ceiling of x, which is the smallest integer not
less than x.
To avoid crossing a word boundary, the compiler moves data types aligned to
bit boundaries in a packed record to the next word.
3.4 Rules for Set Sizes
The maximum number of elements permitted in a set ranges between 481 and
512. This variance is due to the way Pascal implements sets. For efficient
accessing of set elements, Pascal expects the lower-bound of a set to be a
multiple of 32. If for the set specified:
set of a..b
a is not a multiple of 32, Pascal adds elements to the set from a down to the next
multiple of 32 less than a.
For example, the set:
set of 5..31
would have internal padding elements 0..4 added. These padding elements are
inaccessible to the program. This implementation sacrifices some space for a
fast, consistent method of accessing set elements.
The padding required to pad the lower bound down to a multiple of 32 varies
between 0 and 31 elements.
For the set of a..b to be a valid set in Pascal, the following conditions must be
met:
size = ( b − 32 a / 32+ 1 ) < 512

Table 3-7 shows some example sets and whether each set is valid by the above
equation.
Speciﬁcation Lower Upper Set Size Valid Size
set of 1..511 0 (padded down to value by Pascal) 511 512 Yes
set of 0..511 0 511 512 Yes
set of 1..512 0* 512 513 No
set of 31..512 0* 512 513 No
set of 32..512 32 512 481 Yes
set of 32..543 32 543 512 Yes
Table 3-7 Set Speciﬁcations

Chapter 4
4. Pascal/C Interface
This chapter describes the coding interface between Pascal and C. The Fortran
77 Programmer’s Guide describes the Pascal/Fortran interface.
Section 4.1, “Guidelines for Using the Interface,” makes some comparisons
between Pascal and C, and lists guidelines for dealing with the differences
noted.
Section 4.2, “Calling Pascal from C,” lists rules and examples for calling Pascal
from C.
Section 4.3, “Calling C from Pascal,” lists rules and examples for calling C from
Pascal.

4-2 Pascal/C Interface
4.1 Guidelines for Using the Interface
In general, calling C from Pascal and Pascal from C is fairly simple. Most data
types in one language have natural counterparts in the other.
Differences exist in eight areas. Section 4.1.1 through Section 4.1.10 describe
these differences with some guidelines.
4.1.1 Single-precision Floating Point
In function calls, C automatically converts single-precision floating point
values to double-precision. Pascal passes single-precision floating by-value
arguments directly.
Follow these guidelines for passing double-precision values between a C
routine and a Pascal routine:
• If possible, write the Pascal routine so that it receives and returns
double-precision values.
• If the Pascal routine cannot receive a double-precision value, write a
Pascal routine to accept double-precision values from C. Then have that
routine call the single-precision Pascal routine.
The compiler has no problem passing single-precision values by reference
between C and Pascal.
4.1.2 Procedure and Function Parameters
C function variables and parameters consist of a single pointer to machine
code.
Pascal procedure and function parameters consist of a pointer to the machine
code, and a pointer to the stack frame of the lexical parent of the function.
Such values can be declared as structures in C. To create such a structure, put
the C function pointer in the first word and 0 in the second. C functions cannot
be nested, and have no lexical parent; therefore, the second word is irrelevant.
You cannot call a C routine with a function parameter from Pascal.

4.1.3 Pascal By-Value Arrays
C never passes arrays by value. In C, an array is actually a sort of pointer, and
so passing an array actually passes its address, which corresponds to Pascal
by-reference (VAR) array passing.
In practice, this is not a serious problem because passing Pascal arrays by value
is not efficient, and so most Pascal array parameters are VAR anyway. When it
is necessary to call a Pascal routine with a by-value array parameter from C,
pass a C structure containing the corresponding array declaration.
Check your copy of the Pascal Release Notes for detailed instructions to pass
packed array integer subranges by value.
4.1.4 File Variables
The Pascal text type and the C stdio package FILE* are compatible. However,
Pascal passes file variables only by reference. A Pascal routine cannot pass a
file variable by value to a C routine. C routines that pass files to Pascal routines
should pass the address of the FILE* variable, as with any reference parameter.
4.1.5 Passing String Data Between C and Pascal
C and Pascal handle strings differently. Pascal defines a string as a packed
array of characters, where the lower bound of the array is 1 and the upper
bound is an integer greater than 1. C indexes arrays from 0 to max-1. For
example, Pascal string parameters are typically declared so that the upper
bound is large enough to efficiently handle most processing requirements:
var s:packed array[1..100] of char
In passing an array, Pascal passes the entire array as specified, padding to the
end of the array with spaces. Most C programs treat strings as pointers to a
single character and use pointer arithmetic to step through the string. A null
character (0 in C) terminates a string in C.
The following example shows a Pascal routine that calls the C routine strtol
and passes the string s. Note that the routine ensures that the string terminates
with a null character.

type
astrindex = 1..20;
astrindex = packed array [astrindex] of char;
function atoi(var c: astring): integer; external;
program ptest(output);
var
s: astring;
i: astrindex;
begin
argv(1, s); {This predefined Pascal function is a MIPS
extension}
writeln(output, s);
{ Guarantee that the string is null-terminated (but might
bash the last character if the argument is too long).
"lbound" and "hbound" are MIPS extensions. }
s[hbound(s)] := chr(0);
for i := lbound(s) to hbound(s) do
if s[i] = ’ ’ then
begin
s[i] := chr(0);
break;
end;
writeln (output, atoi(s));
end.
For more information about strtol, see the strtol(3c) man page.
4.1.6 Graphics Strings
Using Graphics Library routines requires conversion for Pascal format strings.
You will need to convert Pascal strings to C formats. The procedure ﬁle
/usr/lib/p2cstr.o will perform this conversion for you. If you compile your
program with the -Zg option, this conversion will be done automatically.
The compile option -Zg will link p2cstr.o to perform the conversion. If you do
not use the -Zg option, you must explicitly link p2cstr.o. See Section 2.1.2,
“Pascal Driver Options,” for details.
4.1.7 Passing Variable Arguments
You can deﬁne C functions that take a variable number of arguments (printf
and its variants are examples). You cannot call such functions from Pascal.

4.1.8 Passing Pointers
A Pascal routine cannot pass a function pointer to a C routine.
You can pass a C pointer to a function to Pascal as a structure by value. The first
word of the structure must contain the function pointer and the second word
must contain a zero. Pascal requires this format because it expects an
environment specification in the second word.
4.1.9 Type Checking
Pascal checks certain variables for errors at execution time, whereas C does
not. For example, in a Pascal program, when a reference to an array exceeds its
bounds, the error is flagged (if run time checks are not suppressed). You can
not expect a C program to detect similar errors when you pass data to it from
a Pascal program.
4.1.10 One Main Routine
Only one main routine is allowed per program. You can write the main routine
in either Pascal or C. Here are examples of C and Pascal routines:
Pascal:
program p (output);
begin
writeln ("hi!");
end.
C:
main() {
printf("hi!n");
}

4.2 Calling Pascal from C
To call a Pascal function from C, perform these two tasks:
1. Write a C extern declaration to describe the return value type of the main
routine.
2. Write the call itself with the return value type and argument types as
required by the Pascal routine.
See Section 4.2.3, “Calling a Pascal Function from C” below, for an example.
4.2.1 C Return Values
Use Table 4-1 below as a guide to declaring the return value type.
If Pascal function returns: Declare C function as:
integer (also applies to subranges
with lower bounds < 0)
int
cardinal (also applies to subranges
with lower bounds > 0)
unsigned int
char char
boolean char
enumeration unsigned, or corresponding enum
(recall that C enums are signed)
real none
double double
pointer type corresponding pointer type
record type corresponding structure or union type
array type corresponding array type
Table 4-1 Declaration of Return Value Types

To call a Pascal procedure from C, write an extern declaration in this form:
extern void name();
Then call it with actual arguments with appropriate types.
Use Table 4-2 as a guide for values to pass that correspond to the Pascal
declarations listed.
C does not permit declaration of formal parameter types, but instead infers
them from the types of the actual arguments passed. (See Section 4.2.3 for an
example.)
4.2.2 C to Pascal Arguments
Table 4-2 shows the C argument types to declare in order to match those
expected by the Pascal routine.
If Pascal expects: C argument should be:
integer integer or char value -231
..231
-1
cardinal integer or char value 0..232
-1
subrange integer or char value in subrange
char integer or char (0..255)
boolean integer or char (0 or 1 only)
enumeration integer or char (0..N-1)
real none
double ﬂoat or double
procedure struct {void *p(); int *l}
function struct {function-type *f(); int *l}
pointer types1
pointer type, under 0 := lbound(s)
reference parameter pointer to the appropriate type
record types structure or union type
Table 4-2 C Argument Types

4.2.3 Calling a Pascal Function from C
This example shows a C routine calling a Pascal function.
Pascal:
function bah (
var f: text;
i: integer
) double;
begin
...
end {bah};
C declaration of bah:
extern double bah();
C call:
int i; double d;
FILE *f;
d = bah(&f, i);
by-reference array parameters corresponding array type
by-reference text FILE**
by-value array parameters structure containing the corresponding array
1
To pass a pointer to a function in a C-to-Pascal call, you must pass a structure by
value. The ﬁrst word of the structure must contain the function pointer and the second
word a zero. Pascal requires this format because it expects an environment
speciﬁcation in the second word.
If Pascal expects: C argument should be:
Table 4-2 (continued) C Argument Types

4.2.4 Calling a Pascal Procedure from C
This example shows a C routine calling a Pascal procedure.
Pascal:
type
int_array = array[1..100] of integer;
procedure humbug (
var a: int_array;
n: integer
): integer;
begin
...
end {humbug};
C declaration:
extern void humbug();
C call:
int a[100];
int n;
humbug(a, n);

4.2.5 Passing Strings to a Pascal Procedure
The following example is a C routine that passes strings to a Pascal procedure,
which then prints the strings. The example illustrates two points:
• The Pascal routine must check for the null [chr(0)] character, which
indicates the end of the string passed by the C routine.
• The Pascal routine must not write to output, but instead uses the stdout
ﬁle-stream descriptor passed by the C routine.
C routine:
/* Send the last command-line argument to the Pascal routine */
#include <stdio.h>
main(int argc, char **argv)
{
FILE *temp = stdout;
if (argc != 0)
p_routine(&temp, argv[argc-1]);
}
Pascal routine:
{ We assume the string passed to us by the C program will not
exceed 100 bytes in length. }
type
astring = packed array [1..100] of char;
procedure p_routine(var f: text; var c: astring);
var
i: integer;
begin
i := lbound(c);
{ check for null character }
while (i > hbound(c)) and (c[i] <> chr(0)) do
begin
write (f, c[i]) { write to file stream descriptor
passed from C }
i := i+1;
end;
writeln(f);
end; {p_routine}

4.3 Calling C from Pascal
To call a C routine from Pascal, you must write:
1. A Pascal declaration describing the C routine.
2. A procedure declaration or, if the C routine returns a value, a function
declaration.
3. Parameter and return value declarations corresponding to the C
parameter types, using Table 4-3 below as a guide.
If C expects: Pascal parameter should be:
int (same as signed int, long,
signed long, and signed)
integer
unsigned int (same asunsigned
and unsigned long)
cardinal
short (same as signed short) integer (or -32768..32767)
unsigned short cardinal (or 0..65535)
char (same as unsigned char) char
signed char integer (or -128..127)
ﬂoat double
double double
enum type corresponding enumeration type
string (char *) packed character array passed by reference (VAR)
pointer to function none
FILE* none
FILE** text, passed by reference (VAR)
pointer type corresponding pointer type or corresponding type
passed by reference
struct or union type corresponding record type
array type corresponding array type passed by reference (VAR)
Table 4-3 Pascal Parameter Data Types Expected by C

4.3.1 Calling a C Procedure
The following example shows code calling a C procedure from Pascal.
Note: A Pascal routine cannot pass a function pointer to a C routine.
C routine:
void bah (int i, float f, char *s)
{
...
}
Pascal declaration:
procedure bah (
i: integer;
f: double;
var a: packed array[1..100] of char);
external;
Pascal call:
str := "abc0";
bah(i, 1.0, str);

4.3.2 Calling a C Function
The following example shows code calling a C function from Pascal.
C routine:
float humbug(FILE **f, struct scrooge *x)
{
…
}
Pascal declaration:
type
scrooge_ptr = ^scrooge;
function humbug (
var f: text;
x: scrooge_ptr
): double;
external;
Pascal call:
x := humbug(input, sp);

4.3.3 Passing Arrays
The following example shows code calling a C array from Pascal.
C routine:
int sum(int a[], unsigned n)
{
…
}
Pascal declaration:
type
int_array = array[0..100] of integer;
function sum (
var a: int_array;
n: cardinal
): integer;
external;
avg := sum(samples, hbound(samples) + 1) /
(hbound(samples)+1);

Pascal Programming Guide A-1
Appendix A
A. Man Pages
This appendix is a listing of the pc(1) man page.

Pascal Programming Guide Index-1
Index
Symbols
-c driver option, 2-3
-g option, 2-4
-Zg option, 2-4
–apc option, 1-30
–casesense option, 1-32
–l option, 2-7
–o option, 2-7
–Zg option, 4-4
A
addr function, 1-20
alert, 1-5
alignment by data type, 3-8
alphabetic labels, 1-2
ANSI Standard Pascal, 1-1
argc function, 1-18
argv procedure, 1-15
arrays, 3-1
arrays, records, and variant records, 3-1
assert procedure, 1-15
B
backspace, 1-5
bitand function, 1-19
bitnot function, 1-19
bitor function, 1-19
bitsize function, 1-20
bitxor function, 1-19
braces, xv
brackets, xv
break statement, 1-9
C
C argument types, 4-7
C return values, 4-6
C to Pascal arguments, 4-7
calling a C function, 4-13
calling a C procedure, 4-12
calling a Pascal function from C, 4-8
calling a Pascal procedure from C, 4-9
calling C from Pascal, 4-11
calling Pascal from C, 4-6
cardinal data type extension, 1-24
carriage return, 1-5
case statement

Index-2 Index
otherwise clause, 1-8
case statement constant ranges, 1-8
case statement constants, 1-8
character
alert, 1-5
backspace, 1-5
carriage return, 1-5
form feed, 1-5
horizontal tab, 1-5
newline, 1-5
clock function, 1-19
compilation
separate, 1-10
compiler notes, 1-29
compiling and linking programs, 2-1
compiling multi-language programs, 2-5
compiling, linking, and running Pascal
programs, 2-1
conformant array parameters, 1-28
constant expressions, 1-6
constant operators, 1-6
constants, 1-3
continue statement, 1-9
courier, xv
courier bold, xv
D
date procedure, 1-15
debugging options, 2-4
declaration extensions, 1-10
declaration of return value types, 4-6
document contents summary, xiii
document introduction, xiii
document organization, xiii
double data type extension, 1-24
driver command syntax, 2-5
E
ellipsis, xv
escape character sequences, 1-5
example
record, 3-2
record with different alignment, 3-3
exit statement, 1-9
expressions
constants, 1-6
extensions
declaration, 1-10
Pascal names, 1-2
statement, 1-8
extern attribute, 1-14
external declarations in header file, 1-11
F
file variables, 4-3
FILE*, 4-3
filename on rewrite and reset, 1-21
first function, 1-18
firstof function, 1-20
form feed, 1-5
function
addr, 1-20
argc, 1-18
bitand, 1-19
bitnot, 1-19
bitor, 1-19
bitsize, 1-20
bitxor, 1-19
clock, 1-19
first, 1-18
firstof, 1-20
hbound, 1-17
last, 1-18
lastof, 1-20

lbound, 1-17
lshift, 1-20
max, 1-17
min, 1-17
rshift, 1-20
sizeof, 1-18
function return types, 1-14
functions
predeﬁned, 1-6, 1-16
G
Graphics Library Programming Guide, xiv
graphics option, 2-4
graphics strings, 4-4
H
hbound function, 1-17
horizontal tab, 1-5
I
in out parameter, 1-28
in parameter, 1-28
initialization clauses, 1-13
INTEGER16 data type extension, 1-25
INTEGER32 data type extension, 1-25
interface guidelines, 4-2
internal attribute, 1-14
I/O extension
ﬁlename on rewrite and reset, 1-21
lazy I/O, 1-23
reading and writing enumeration types, 1-22
reading character strings, 1-21
specifying radix in the write statement, 1-21
standard error, 1-23
I/O extensions, 1-21
IRIS-4D Pascal Graphics Library, xiv
IRIS-4D Series Compiler Guide, xiv
IRIX debugger dbx, xiv
italic, xv
L
labels
alphabetic, 1-2
last function, 1-18
lastof function, 1-20
lazy I/O, 1-23
lbound function, 1-17
linking separate language objects, 2-6
lowercase, 1-2
lowercase in public names, 1-2
lshift function, 1-20
M
macro preprocessor, 1-29
main routine, 4-5
making inter-language calls, 2-7
manual page, xiv
max function, 1-17
maximum limits of data items, 1-30
min function, 1-17
multi-language compile process, 2-6
N
names, 1-2
Pascal, 1-2
newline, 1-5
next statement, 1-9

Index-4 Index
non-decimal number constants, 1-3
non-graphic characters, 1-4
non-range elements in a packed record, 3-7
non-range elements in an unpacked record,
3-7
non-ranges following ranges in unpacked
records, 3-6
notation and syntax conventions, xv
O
operators
constants, 1-6
option
-apc, 1-30
-casesense, 1-32
otherwise clause, 1-8
out parameter, 1-28
P
p2cstr.o, 4-4
packed record alignment, 3-11
packed records, 1-27
parameter
in, 1-28
in out, 1-28
out, 1-28
parameter extension
univ, 1-28
parameter extensions, 1-28
parentheses, xv
Pascal
alphabetic labels, 1-2
constants, 1-3
implementation, 1-1
names, 1-2
Release Notes, xiii, 1-1
Pascal by-value arrays, 4-3
Pascal compile process, 2-3
Pascal compiler, xiv
Pascal driver, 2-2
Pascal driver options, 2-3
Pascal implementation, 1-1
Pascal name extensions, 1-2
Pascal names, 1-2
Pascal parameter data types expected by C,
4-11
Pascal programming environment, xv
Pascal Release Notes, xiii, 1-1
Pascal/C interface, 4-1
passing arrays, 4-14
passing string data between C and Pascal, 4-3
passing strings to a Pascal procedure, 4-10
passing variable arguments, 4-4
pc(1) man page, 2-3
pointer data type extension, 1-24
predefined data type attribute
static, 1-26
volatile, 1-26
predefined data type attributes, 1-26
predefined data type extension
cardinal, 1-24
double, 1-24
INTEGER16, 1-25
INTEGER32, 1-25
pointer, 1-24
string, 1-25
predefined data type extensions, 1-24
predefined function
addr, 1-20
argc, 1-18
bitand, 1-19
bitnot, 1-19
bitor, 1-19
bitsize, 1-20
bitxor, 1-19

clock, 1-19
first, 1-18
firstof, 1-20
hbound, 1-17
last, 1-18
lastof, 1-20
lbound, 1-17
lshift, 1-20
max, 1-17
min, 1-17
rshift, 1-20
sizeof, 1-18
predefined functions, 1-6, 1-16
predefined procedure
argv, 1-15
assert, 1-15
date, 1-15
time, 1-16
predefined procedures, 1-15
procedure and function parameters, 4-2
producing a linkable object file, 2-3
program compilation unit, 1-10
programming procedure, xiv
public names, 1-2
R
ranges, 3-5
ranges in a packed record, 3-5
ranges in an unpacked record, 3-5, 3-6
reading and writing enumeration types, 1-22
reading character strings, 1-21
real and double maximum values, 3-8
record in storage, end padded, 3-3
record in storage, middle padding, 3-4
records, 3-1, 3-2
related documentation, xv
relax declaration ordering, 1-14
Release Notes, xiii, 1-1
rename the executable, 2-4
return statement, 1-8
rshift function, 1-20
rules for set sizes, 3-12
running programs, 2-7
S
separate compilation, 1-10
separate compilation unit, 1-10
separate compilation unit with external
declarations, 1-12
sequences
escape character, 1-5
set size rules, 3-12
set specifications, 3-13
shared variables, 1-12
short circuiting, 1-30
single-precision floating point, 4-2
size and alignment of data types in unpacked
records or arrays, 3-9
size and alignment of Pascal packed arrays,
3-10
size and alignment of Pascal packed records,
3-11
Size by data type, 3-8
sizeof function, 1-18
sizing for packed arrays by type, 3-10
sizing for unpacked records, 3-9
specifying radix in the write statement, 1-21
standard error, 1-23
statement
break, 1-9
continue, 1-9
next, 1-9
return, 1-8

Index-6 Index
statement extensions, 1-8
static arrays, 1-27
static data type attribute, 1-26
static variables of type record, 1-27
stdout, 4-10
storage mapping, 3-1
string data type extension, 1-25
string padding, 1-4
strtol, 4-3
strtol(3c) man page, 4-4
syntax convention
braces, xv
brackets, xv
courier, xv
courier bold, xv
ellipsis, xv
italics, xv
parentheses, xv
vertical bar, xv
T
time procedure, 1-16
translation limits, 1-30
type checking, 4-5
type functions, 1-16
U
underscores, 1-2
univ parameter extension, 1-28
use of underscores, 1-2
V
value by data type, 3-8
value ranges by data type, 3-8
VAR, 4-3
variables
shared, 1-12
variant records, 3-1, 3-4
vertical bar, xv
volatile data type attribute, 1-26

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Pascal

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