User's Manual

Table 19 Symbol names
DefinitionSymbol
Largest architecture revision level used by any compilation unit__SYSTEM_ID
Initial value of FPU status register._FPU_STATUS
Address of first byte following the end of the main program's data segment; identifies the beginning
of the heap segment.
_end
Size of the Thread Local Storage segment required by the program. This symbol is not reserved
in PA32 (SOM).
__TLS_SIZE
Beginning of the text segment.__text_start
End of the text segment._etext
Beginning of the data segment.__data_start
End of initialized data._edata
Global pointer value. This symbol is not reserved in PA32 (SOM).__gp
Beginning of the .init section.__init_start
End of the .init section.__init_end
Beginning of the .fini section.__fini_start
End of the .fini section.__fini_end
Beginning of the unwind table. This symbol is not reserved in PA32 (SOM).__unwind_start
End of the unwind table. This symbol is not reserved in PA32 (SOM).__unwind_end
Dynamic Path Searching for Shared Libraries
Dynamic path searching is the process that enables you to specify the location of shared libraries
at run time. In PA-32 mode, you can enable run-time dynamic path searching of shared libraries
in the following ways:
• By linking the program with +s, enabling the program to use the path list defined by the
SHLIB_PATH environment variable at run time.
• By storing a directory path list in the program with the linker option +b path_list.
If +s or +b path_list is enabled, all shared libraries specified with the -l library or -l:library linker
options are subject to a dynamic path lookup at run time.
In IPF, the dynamic path searching behavior has changed (same as PA-64 mode):
• The +s dynamic path searching option is enabled by default. It is not enabled by default in
PA-32 mode.
• The LD_LIBRARY_PATH environment variable is available in addition to the SHLIB_PATH
environment variable.
• An embedded run-time path list called RUNPATH may be stored in the executable. If +b
path_list is specified at link time, these directories are added to RUNPATH. If +b path_list is
not specified, the linker creates a default RUNPATH consisting of:
1. directories in the -L option (if specified), followed by
2. directories in the LPATH environment variable (if specified).
• By default, the linker ignores the ordering of the +b path_list and +s options.
• At run time, the dynamic loader searches directory paths in the following order:
dynamic path (if set using dlsetlibpath())1.
2. LD_LIBRARY_PATH (if set)
Dynamic Path Searching for Shared Libraries 83