[Bug other/16600] New: gcc/configure.ac problem: gcc_gxx_include_dir computation wrong

["dylan at dylex dot net" <gcc-bugzilla at gcc dot gnu dot org>]

gcc/configure.ac:139 in 3.4.1 (also on trunk)
gcc_gxx_include_dir is computed by taking $libsubdir/$unlibsubdir/.. and
appending exec_prefix with leading prefix stripped, all components replaced by
"..".  This is all dandy for normal people, but (for multi-arch support) I use
things like:
  --prefix=/usr/local/gcc-3.4.1 --exec-prefix=/usr/local/gcc-3.4.1-x86_64
Which results in
  ignoring nonexistent directory
"/usr/local/gcc-3.4.1/lib/gcc/x86_64-pc-linux/3.4.1/../../../..-x86_64/include/c++/3.4.1"
which is completely wrong.  I recommend this (untested):
  gcc_gxx_include_dir="\$(libsubdir)/\$(unlibsubdir)/..\`echo \$(exec_prefix) |
sed -e 's|^\$(prefix)\(/\|$\)|\1|' -e
's|/[^/]*|/..|g'\`/include/"${libstdcxx_incdir}

-- 
           Summary: gcc/configure.ac problem: gcc_gxx_include_dir
                    computation wrong
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: other
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dylan at dylex dot net
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: x86_64-pc-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16600