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.
The problem is that collect2 first looks in ".a" libraries for symbols and then
in ".so" libraries. It ignores -brtl (which redefines the library search order
to ".so" first and ".a" second).
--
Summary: collect2 uses wrong search order if -brtl specified
Product: gcc
Version: 3.3.2
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: other
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: bugzilla-gcc at thewrittenword dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: powerpc-ibm-aix5.2.0.0
GCC host triplet: powerpc-ibm-aix5.2.0.0
GCC target triplet: powerpc-ibm-aix5.2.0.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18720
