On Sun, Mar 29, 2015 at 7:34 PM, H.J. Lu <hjl.to...@gmail.com> wrote: > On Sun, Mar 29, 2015 at 7:25 PM, H.J. Lu <hjl.to...@gmail.com> wrote: >> We shouldn't call external function, __cpu_indicator_init, while an object >> is being relocated since its .got.plt section hasn't been updated. It >> works for non-PIE since no update on .got.plt section is required. This >> patch hides __cpu_indicator_init/__cpu_model from linker to force linker >> to resolve __cpu_indicator_init/__cpu_model to their hidden definitions >> in libgcc.a while providing backward binary compatibility. >> >> OK for trunk, 4.9 and 4.9 branches? >> >> Thanks. >> >> >> H.J. >> --- >> libgcc/ >> >> PR target/65612 >> * config/i386/cpuinfo.c (__cpu_model): Initialize. >> (__cpu_indicator_init@GCC_4.8.0): New. >> (__cpu_model@GCC_4.8.0): Likewise. >> >> gcc/testsuite/ >> >> PR target/65612 >> * g++.dg/ext/mv18.C: New test. >> * g++.dg/ext/mv19.C: Likewise. >> * g++.dg/ext/mv20.C: Likewise. > > It doesn' work for shared C++ library: > > /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/g++ -O2 -c > -o main.o main.cc > /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/g++ -shared > -fPIC -O2 -o libmv20.so mv20.cc > /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/g++ -O2 -o x > main.o libmv20.so -Wl,-R,. > /usr/local/bin/ld: x: hidden symbol `__cpu_model' in > /export/build/gnu/gcc-x32/release/usr/gcc-5.0.0-x32/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.0.0/libgcc.a(cpuinfo.o) > is referenced by DSO > /usr/local/bin/ld: final link failed: Bad value > collect2: error: ld returned 1 exit status > Makefile:12: recipe for target 'x' failed > make: *** [x] Error 1 > [hjl@gnu-tools-1 pr65612]$ > > -- > H.J.
We need something like libgcc_nonshared.a, which contains cpuinfo.o, and link together with -lgcc_s when creating executable or DSO. -- H.J.
