"Dan Nicholson" <[EMAIL PROTECTED]> writes: [...]
> And now I've come upon this old thread: > > http://rpm5.org/community/rpm-devel/1554.html > > This is definitely the problem. When --as-needed is used, libc is > bound first to tmire, causing regcomp and friends to be resolved > through libc rather than libpcreposix. the symbol conflict is a mess. pcreposix better be fixed (http://rpm5.org/community/rpm-devel/1562.html) it's hard to beat libc... here is what happens: % echo 'int f() { regcomp(); }' > liba.c % gcc -shared -o liba.so liba.c -lpcreposix % ldd liba.so libpcreposix.so.0 => /usr/lib/libpcreposix.so.0 (0xb7f76000) libc.so.6 => /lib/i686/libc.so.6 (0xb7e28000) libpcre.so.0 => /lib/libpcre.so.0 (0xb7e00000) % gcc -shared -o liba_.so liba.so % LD_LIBRARY_PATH=`pwd` ldd liba_.so liba.so => /tmp/liba.so (0xb7f44000) libc.so.6 => /lib/i686/libc.so.6 (0xb7de2000) libpcreposix.so.0 => /usr/lib/libpcreposix.so.0 (0xb7de0000) libpcre.so.0 => /lib/libpcre.so.0 (0xb7db8000) one can see -lc has been added. confirmed by: % gcc -nostdlib -shared -o liba_.so liba.so % LD_LIBRARY_PATH=`pwd` ldd liba_.so liba.so => /tmp/liba.so (0xb7f19000) libpcreposix.so.0 => /usr/lib/libpcreposix.so.0 (0xb7f03000) libc.so.6 => /lib/i686/libc.so.6 (0xb7db5000) libpcre.so.0 => /lib/libpcre.so.0 (0xb7d8d000) but using -nostdlib is harder when building a binary... hence the need to force -lpcreposix at each linking steps: % gcc -shared -o liba_.so liba.so -lpcreposix % LD_LIBRARY_PATH=`pwd` ldd liba_.so liba.so => /tmp/liba.so (0xb7f9f000) libpcreposix.so.0 => /usr/lib/libpcreposix.so.0 (0xb7f89000) libc.so.6 => /lib/i686/libc.so.6 (0xb7e3b000) libpcre.so.0 => /lib/libpcre.so.0 (0xb7e13000) which defeats the idea of DSO which should handle their deps themselves. and such hacks do not play well with --as-needed: export LD_LIBRARY_PATH=/tmp cd /tmp echo 'int f() { printf("fa "); }' > liba.c echo 'int f() { printf("fb "); }' > libb.c echo 'int g() { }' >> libb.c echo 'int h() { f(); g(); }' > libx.c echo 'main() { h(); g(); printf("\n"); }' > t.c gcc -o liba.so -shared liba.c gcc -o libb.so -shared libb.c gcc -o libx.so -shared libx.c -L. -la -lb gcc t.c -L. -lx ; ./a.out # fb gcc t.c -L. -lx -la; ./a.out # fa gcc -Wl,--as-needed t.c -L. -lx -la; ./a.out # fb i wonder if ld could have a warning to detect about multiple symbols in DSO and so tell about possible issues with --as-needed. ______________________________________________________________________ RPM Package Manager http://rpm5.org Developer Communication List rpm-devel@rpm5.org
