------- Additional Comments From hjl at lucon dot org 2005-03-03 00:05 ------- Created an attachment (id=8315) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8315&action=view) A testcase
/export/build/gnu/gcc-4.0/build-x86_64-linux/gcc/xgcc -B/export/build/gnu/gcc-4.0/build-x86_64-linux/gcc/ -O2 -fPIC -c -o foo.o foo.c /export/build/gnu/gcc-4.0/build-x86_64-linux/gcc/xgcc -B/export/build/gnu/gcc-4.0/build-x86_64-linux/gcc/ -o libfoo.so -shared foo.o foo.o: In function `foo': foo.c:(.text+0x5): undefined reference to `memcpy' /usr/local/bin/ld: foo.o: relocation R_X86_64_PC32 against `memcpy' can not be used when making a shared object; recompile with -fPIC /usr/local/bin/ld: final link failed: Bad value collect2: ld returned 1 exit status make: *** [libfoo.so] Error 1 The problem is gcc mishandles #pragma GCC visibility push(hidden) #pragma GCC visibility push(default) typedef long unsigned int size_t; extern void *memcpy (void *, const void *, size_t); #pragma GCC visibility pop and thinks memcpy is hidden. It only happens to builtin functions. When memcpy is renamed to bar, gcc is OK. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20297
