A proposed change to Xorg upstream would use GNU ld's -wrap option
to simplify some of the test cases that have to override functions
with test wrappers - is there a Solaris ld equivalent of this
functionality? A command line equivalent would be preferable, but
a mapfile option could be made to work. It seems like it's a
combination of symbol renaming, direct linking and an automatic
dlsym alias to the function in a linked library.
The GNU ld documentation of this option:
--wrap symbol
Use a wrapper function for symbol. Any undefined reference to
symbol will be resolved to __wrap_symbol. Any undefined reference
to __real_symbol will be resolved to symbol.
This can be used to provide a wrapper for a system function. The
wrapper function should be called __wrap_symbol. If it wishes to
call the system function, it should call __real_symbol.
Here is a trivial example:
void *
__wrap_malloc (size_t c)
{
printf ("malloc called with %zu\n", c);
return __real_malloc (c);
}
If you link other code with this file using --wrap malloc, then
all calls to malloc will call the function __wrap_malloc
instead. The call to __real_malloc in __wrap_malloc will call the
real malloc function.
You may wish to provide a __real_malloc function as well, so that
links without the --wrap option will succeed. If you do this, you
should not put the definition of __real_malloc in the same file as
__wrap_malloc; if you do, the assembler may resolve the call
before the linker has a chance to wrap it to malloc.
(copied from
http://sourceware.org/binutils/docs-2.19/ld/Options.html#index-g_t_002d_002dwrap-249
)
--
-Alan Coopersmith- alan.coopersmith at sun.com
Sun Microsystems, Inc. - X Window System Engineering
