I've had a few problems trying to build a profiling version of SpiderMonkey from gecko-1.9.2 on OS X.
First, in order to build SpiderMonkey at all on OS X 10.6, it's necessary to pick GCC 4.0 because the standard GCC 4.2.1 can't build it.
$ CC=gcc-4.0 CXX=g++-4.0 ../configure --enable-optimize --disable-debug
Then, in order to turn on the profiling support, the
-pg flag must be passed to the compiler and linker:
$ CC=gcc-4.0 CXX=g++-4.0 ../configure --enable-optimize="-O3 -fstrict-aliasing -pg" --disable-debug
Finally, to stop the resulting JS shell from instantly crashing,
__attribute((fastcall)) needs to be turned off in