[Bug lto/59582] LTO discards symbol that defined as weak elsewhere

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59582

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> ---
Works for me:

[hjl@gnu-6 pr59582]$ cat main.c 
int callback() { return 0; }
int main() { return s_func(); }
[hjl@gnu-6 pr59582]$ cat ext.c 
__attribute__((weak)) int callback() { return 1; }
int s_func() { return callback(); }
[hjl@gnu-6 pr59582]$ make
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/  -c -o ext.o ext.c
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -flto   -c -o main.o main.c
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -flto  ext.o main.o -o e
[hjl@gnu-6 pr59582]$ ld -V
GNU ld (GNU Binutils) 2.24.51.20131224
  Supported emulations:
   elf_x86_64
   elf32_x86_64
   elf_i386
   i386linux
   elf_l1om
   elf_k1om
[hjl@gnu-6 pr59582]$ /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc -v
Using built-in specs.
COLLECT_GCC=/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
Target: x86_64-unknown-linux-gnu
Configured with: /export/gnu/import/git/gcc/configure
--enable-languages=c,c++,fortran --disable-bootstrap --prefix=/usr/gcc-4.9.0
--with-local-prefix=/usr/local --enable-gnu-indirect-function --with-fpmath=sse
Thread model: posix
gcc version 4.9.0 20131223 (experimental) (GCC) 
[hjl@gnu-6 pr59582]$