Guardian Procedure Calls Reference Manual (G06.25+)

Introduction to Guardian Procedure Calls
Guardian Procedure Calls Reference Manual—522629-013
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External Declarations Files for Guardian Procedures
External Declarations Files for Guardian
Procedures
Like all procedures in an application program, Guardian procedures must be declared
before they can be called. Guardian procedures are declared as external procedures.
A $SYSTEM.SYSTEM file contains many of the Guardian procedure declarations for
each programming language. For example:
•
pTAL declarations are in $SYSTEM.SYSTEM.EXTDECS0.
•
C declarations are in $SYSTEM.SYSTEM.CEXTDECS (usually referred to as the
cextdecs file).
Other header files in $SYSTEM.SYSTEM also contain Guardian procedure
declarations. For example:
•
$SYSTEM.SYSTEM.HSETJMP contains declarations for procedures that perform
nonlocal goto operations.
•
$SYSTEM.SYSTEM.HTDMSIG contains declarations for the signal-handling
procedures.
The setjmp.h and tdmsig.h header files contain the equivalent C language
declarations.
Your application should include the appropriate compiler instructions specifying the
names of the appropriate external declarations files and the Guardian procedures that
your application calls. The compiler instruction must precede the first invocation of a
Guardian procedure. Refer to your programming language reference manual for
information about compiler instructions. For example:
•
Refer to the pTAL Reference Manual for details on using the SOURCE compiler
command with the TAL and pTAL programming languages.
•
Refer to the C/C++ Programmer’s Guide for details on using the #include
compiler command with the C programming language.
The procedure syntax descriptions for TAL and pTAL throughout this manual assume
that an external declarations file (EXTDECS0, EXTDECS1, or EXTDECS) on
$SYSTEM.SYSTEM is declared. Where a different header file is needed, the
appropriate SOURCE compiler command is shown with the syntax.
Multiple versions of the external declarations file are provided for compiling your
program to run on previous versions of the operating system as well as on the current
version; older versions, however, do not support pTAL. Procedures that require
EXTDECS0 are noted. For further information, refer to the Guardian Programmer’s
Guide.