this is documented in doc/install.texi: """ This option is only useful when you are already using @option{--with-sysroot}."""
now, lets error out if you configure --with-build-sysroot without --with-sysroot. Ok for the trunk? This was hit in PR55743. I think the patch in http://gcc.gnu.org/ml/gcc-patches/2013-01/msg00198.html is still valid, but independent of this. Matthias
gcc/ 2013-01-14 Matthias Klose <d...@ubuntu.com> * configure.ac: fail --with-build-sysroot without --with-sysroot. * configure: Regenerate. Index: gcc/configure.ac =================================================================== --- gcc/configure.ac (Revision 195151) +++ gcc/configure.ac (Arbeitskopie) @@ -755,15 +755,6 @@ configured_native_system_header_dir="${withval}" ], [configured_native_system_header_dir=]) -AC_ARG_WITH(build-sysroot, - [AS_HELP_STRING([--with-build-sysroot=sysroot], - [use sysroot as the system root during the build])], - [if test x"$withval" != x ; then - SYSROOT_CFLAGS_FOR_TARGET="--sysroot=$withval" - fi], - [SYSROOT_CFLAGS_FOR_TARGET=]) -AC_SUBST(SYSROOT_CFLAGS_FOR_TARGET) - if test "x$prefix" = xNONE; then test_prefix=/usr/local else @@ -805,6 +796,19 @@ AC_SUBST(TARGET_SYSTEM_ROOT_DEFINE) AC_SUBST(CROSS_SYSTEM_HEADER_DIR) +AC_ARG_WITH(build-sysroot, + [AS_HELP_STRING([--with-build-sysroot=sysroot], + [use sysroot as the system root during the build])], + [if test x"$withval" != x ; then + SYSROOT_CFLAGS_FOR_TARGET="--sysroot=$withval" + fi], + [SYSROOT_CFLAGS_FOR_TARGET=]) +AC_SUBST(SYSROOT_CFLAGS_FOR_TARGET) +if test x"$TARGET_SYSTEM_ROOT" = x && test x"$SYSROOT_CFLAGS_FOR_TARGET" != x +then + AC_MSG_ERROR([option --with-build-sysroot requires --with-sysroot]) +fi + AC_ARG_WITH(specs, [AS_HELP_STRING([--with-specs=SPECS], [add SPECS to driver command-line processing])],