Open System Services Porting Guide (G06.24+, H06.03+)

Table Of Contents
Migrating Guardian Applications to the OSS
Environment
Open System Services Porting Guide520573-006
8-26
Include File Search Order
/usr/include/stdio.h are identical to the contents of
$SYSTEM.SYSTEM.STDIOH, for example.
Any Guardian C or C++ source code that includes completely qualified header file
names in Guardian filename syntax must be modified to use the equivalent OSS
pathname syntax.
Include File Search Order
When C or C++ source modules are compiled in the Guardian environment, the search
order for header files included in the source code is given by the SSV pragma list
provided. When using c89, #include files with names enclosed in double quotes
("") are searched for first in the current directory. The #include files with names
surrounded by angle brackets (<>) or the continued search of #include files
enclosed in double quotes occurs in the directories named with the -I flags specified
in the compiler command line in the order from left to right. Finally #include files are
searched for in the /usr/include directory.
New Pragmas
Some of the compiler pragmas used in Guardian C or C++ programs have no effect in
the OSS environment. When C or C++ program modules are compiled by c89, the
following pragmas are ignored or generate an error:
These pragmas can be removed from the C or C++ source files if the source files are
to be compiled in the OSS environment.
Feature-Test Macros
Feature-test macros control the visibility of symbols. They determine which set of
features is included in header files. The following feature-test macros can be used in
the OSS environment. Which symbols are defined by including a standard header file
is determined as described in Feature-Test Macros on page 7-13.
The feature-test macro _XOPEN_SOURCE is set by default in c89. The
_XOPEN_SOURCE macro is a superset of the _POSIX_SOURCE and
_POSIX_C_SOURCE macros. The _TANDEM_SOURCE feature-test macro is used to
make identifiers defined by HP visible.
RUNNABLE Generates executable object file
SEARCH Searches object file to resolve external references (used with
RUNNABLE)
SSV Specifies list of search subvolumes for files in #include
directives
NOXMEM Gives an error; all OSS programs are wide model