On Thu, Oct 14, 2010 at 23:53, Jeff Squyres <jsquyres@cisco.com> wrote:

The configure test essentially looks like this -- could you try this manually and see what happens?

cat > conftest_weak.h <<EOF
int real(int i);
int fake(int i);
EOF

cat > conftest_weak.c <<EOF
#include "conftest_weak.h"
#pragma weak fake = real
int real(int i) { return i; }
EOF

cat > conftest.c <<EOF
#include "conftest_weak.h"
int main() { return fake(3); }
EOF

# Try the compile
clang $CFLAGS -c conftest_weak.c
clang $CFLAGS conftest.c conftest_weak.o -o conftest $LDFLAGS $LIBS

The configure test rules that weak symbol support is there if both compiler invocations return an exit status of 0.

They exit 0 and

$ nm conftest |g 'real|fake'

00000000004004a0 W fake

00000000004004a0 T real

so it looks like that is working fine. It also works fine when I stuff it into a shared library:

$ clang -c -fPIC conftest_weak.c

$ clang -shared -fPIC conftest.c conftest_weak.o -o conftest.so

$ nm conftest.so |g 'real|fake'

00000000000005a0 W fake

00000000000005a0 T real

Jed