This fixes an annyoing regression introduced in 2012 by this change:
https://codereview.appspot.com/5394041
The idea of the change is to interpolate the value passed to --with-sysroot in
the value passed to --with-gxx-include-dir, so that you can change the sysroot
at run time, i.e. pass --sysroot to the compiler, and have the gxx-include-dir
automatically translated relatively to the new sysroot.
The original submission did just that:
https://gcc.gnu.org/ml/gcc-patches/2011-11/msg01751.html
but it was probably done against a branch so the version eventually installed
does the interpolation unconditionally, i.e. even when gxx-include-dir is the
default C++ include path in the install tree.
The result is that, if you configure --with-sysroot with a value that happens
to be identical to the start of the default C++ path in the install tree, the
mechanism triggers and the C++ include path is completely broken if you pass
--sysroot to the compiler. IOW the same issue as the one meant to be fixed,
but this time when --with-gxx-include-dir is not passed.
So the attached patch restores the original implementation by doing the
interpolation only when both --with-sysroot and --with-gxx-include-dir are
specified on the configure line.
Tested on x86-64/Linux, applied on the mainline as obvious.
2018-05-10 Eric Botcazou <ebotca...@adacore.com>
* configure.ac (gcc_gxx_include_dir_add_sysroot): Set it to 1 only
when --with-gxx-include-dir is also specified.
* configure: Regenerate.
--
Eric BotcazouIndex: configure.ac
===================================================================
--- configure.ac (revision 260071)
+++ configure.ac (working copy)
@@ -205,6 +205,11 @@ no) ;;
*) gcc_gxx_include_dir=$with_gxx_include_dir ;;
esac])
+# If both --with-sysroot and --with-gxx-include-dir are passed, we interpolate
+# the former in the latter and, upon success, compute gcc_gxx_include_dir as
+# relative to the sysroot.
+gcc_gxx_include_dir_add_sysroot=0
+
# This logic must match libstdc++-v3/acinclude.m4:GLIBCXX_EXPORT_INSTALL_INFO.
if test x${gcc_gxx_include_dir} = x; then
if test x${enable_version_specific_runtime_libs} = xyes; then
@@ -216,15 +221,10 @@ if test x${gcc_gxx_include_dir} = x; the
fi
gcc_gxx_include_dir="\$(libsubdir)/\$(libsubdir_to_prefix)$libstdcxx_incdir"
fi
-fi
-
-gcc_gxx_include_dir_add_sysroot=0
-if test "${with_sysroot+set}" = set; then
+elif test "${with_sysroot+set}" = set; then
gcc_gxx_without_sysroot=`expr "${gcc_gxx_include_dir}" : "${with_sysroot}"'\(.*\)'`
if test "${gcc_gxx_without_sysroot}"; then
- if test x${with_sysroot} != x/; then
- gcc_gxx_include_dir="${gcc_gxx_without_sysroot}"
- fi
+ gcc_gxx_include_dir="${gcc_gxx_without_sysroot}"
gcc_gxx_include_dir_add_sysroot=1
fi
fi
