[Bug bootstrap/44107] libstdc++ (dylib) is built with an erroneous dependency towards /usr/lib

["Denis.Excoffier at airbus dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44107

--- Comment #10 from Denis Excoffier <Denis.Excoffier at airbus dot com> 2011-03-20 20:34:37 UTC ---
(In reply to comment #8)
> "DYLD_PRINT_LIBRARIES=1 ./myexe " 
> is really useful for making sure that the libraries you think should be used
> actually are ;-)
This is great, thank you for the hint.

This shows that the sets 'y' (ie patched) and 'z' (ie unchanged) have a real
dependency towards /usr/lib/libgcc_s.1.dylib. The set 'x' (modif
t-slibgcc-darwin) does not have it. Perhaps (i don't know) it is inside anyway
(i mean statically) but i suppose that  if some libgcc_s.1.dylib must be
statically included, the one just-compiled will be chosen.

Now comes the question of the beginning (which is also included in the title of
this PR): why does my C++ program have (like in 'y' or 'z'+DYLD_LIBRARY_PATH)
to use a /usr/lib/libgcc_s.1.dylib (dated 2007-10-06, 264016 bytes on my Darwin
9.8.0), when we could take advantage of the one in $(prefix)/lib (newer and
only 89656 bytes), or none at all (like in 'x')?

Second question, why is /usr/lib hardwired into t-slibgcc-darwin (line 31)?
That fact, let it alone, is already suspicious for me...