6.59.7 Symbol-Renaming Pragmas
For compatibility with the Solaris system headers, GCC
#pragma directives that change the name used in
assembly for a given declaration. To get this effect
on all platforms supported by GCC, use the asm labels extension (see Asm Labels).
redefine_extname oldname newname
This pragma gives the C function oldname the assembly symbol
newname. The preprocessor macro
is defined if this pragma is available (currently on all platforms).
This pragma and the asm labels extension interact in a complicated
manner. Here are some corner cases you may want to be aware of.
- Both pragmas silently apply only to declarations with external
linkage. Asm labels do not have this restriction.
- In C++, both pragmas silently apply only to declarations with
“C” linkage. Again, asm labels do not have this restriction.
- If any of the three ways of changing the assembly name of a
declaration is applied to a declaration whose assembly name has
already been determined (either by a previous use of one of these
features, or because the compiler needed the assembly name in order to
generate code), and the new name is different, a warning issues and
the name does not change.
- The oldname used by
#pragma redefine_extname is
always the C-language name.