I tried building libsigc++-2.0.6 (http://libsigc.sourceforge.net/) on AIX 5.2 with GCC 3.3.2 and 3.4.2. GCC 3.4.2 worked fine. However, with GCC 3.3.2, I ran into the following problem: .. /bin/sh ../libtool --mode=link g++ -O2 -mcpu=common -Wl,-blibpath:/opt/TWWfsw/gcc332r/lib -Wl,-brtl -Wl,-blibpath:/usr/lib -o test_trackable test_trackable.o ../sigc++/libsigc-2.0.la g++ -O2 -mcpu=common -Wl,-blibpath:/opt/TWWfsw/gcc332r/lib -Wl,-brtl -Wl,-blibpath:/usr/lib -o .libs/test_trackable test_trackable.o -L../sigc++/.libs -lsigc-2.0 -L/opt/TWWfsw/gcc332/lib -lstdc++ -Wl,-blibpath:/opt/TWWfsw/libsigc++20/lib/gcc32:\ /opt/TWWfsw/gcc332/lib:/opt/TWWfsw/gcc332r/lib:/usr/lib ld: 0711-317 ERROR: Undefined symbol: _GLOBAL__F_signal.ccAo6sTo ld: 0711-317 ERROR: Undefined symbol: _GLOBAL__F_functors_slot.cccL3Cqq Because I set LDFLAGS="-Wl,-brtl" during the ./configure state, libtool will create a static and shared version of the libsigc++ library. The two undefined symbols, _GLOBAL__F_signal.ccAo6sTo and _GLOBAL__F_functors_slot.cccL3Cqq, come from the static version of the libsigc++ library, ../sigc++/.libs/libsigc-2.0.a. I thought it odd the linker would use ../sigc++/.libs/libsigc-2.0.a rather than ../sigc++/.libs/libsigc-2.0.so. However, after adding "-v -Wl,-v" to the final link command, I found the following: g++ -v -Wl,-v -O2 -mcpu=common -Wl,-blibpath:/opt/TWWfsw/gcc332r/lib -Wl,-brtl -Wl,-blibpath:/usr/lib -o .libs/test_trackable test_trackable.o -L../sigc++/.libs -lsigc-2.0 -L/opt/TWWfsw/gcc332/lib -lstdc++ -Wl,-blibpath:/opt/TWWfsw/libsigc++20/lib/gcc32:\ /opt/TWWfsw/gcc332/lib:/opt/TWWfsw/gcc332r/lib:/usr/lib ... /opt/TWWfsw/gcc332/bin/g++ -x c -c -o /tmp//ccI74qdc.o -mcpu=common -fno-exceptions -w /tmp//ccgMXWab.c ... Looking at the /tmp/ccgMXWab.c file, I see: extern void *x13 __asm__ ("_GLOBAL__F_signal.ccAo6sTo"); extern void *x19 __asm__ ("_GLOBAL__F_functors_slot.cccL3Cqq"); If I change these two lines to match the corresponding entries in ../sigc++/.libs/libsigc-2.0.so: extern void *x13 __asm__ ("_GLOBAL__F_signal.ccKvSdiF"); extern void *x19 __asm__ ("_GLOBAL__F_functors_slot.ccHOMFb6"); then the link step that failed above succeeds. So, is the error because collect2 is not honoring -brtl and reading ../sigc++/.libs/libsigc-2.0.a rather than ../sigc++/.libs/libsigc-2.0.so? If so, what is the solution? BTW, GCC 3.4.2 doesn't seem to have this problem because it never generates the _GLOBAL__F_signal or _GLOBAL__F_functors_slot entries. Also, the "ccKvSdiF" extension to _GLOBAL__F_signal changes at every compilation so we cannot rely on it as a constant value. -- albert chin (china@xxxxxxxxxxxxxxxxxx)
