2017-02-19 18:47:28 UTC
In many installations, clang has strange/odd/buggy library search paths. In
particular, on the Ubuntu binaries from http://releases.llvm.org/download.html
search in /lib64/ although this directory contains no libraries (only the ld.so).
This confuses the AC_LIB_PREPARE_MULTILIB macro: it expects 64-bit libraries
in $PREFIX/lib64 (this hack was implemented for the sake of openSUSE systems).
But in Ubuntu, 64-bit binaries are in $PREFIX/lib.
I'm adding two patches:
1) The ability for the user to override the results of AC_LIB_PREPARE_MULTILIB.
With this patch, I can run the configuration with
acl_cv_libdirstems=lib,lib64 CC=clang ./configure --with-libsigsegv-prefix=...
and it (i.e. gl_LIBSIGSEGV) will find the installed 64-bit binaries of
libsigsegv, whereas before with just
CC=clang ./configure --with-libsigsegv-prefix=...
it did not find them.
2) Prefer to ask the system compiler (/usr/bin/gcc) about the characteristics of
the system, rather than $CC.