[Bug bootstrap/62077] --with-build-config=bootstrap-lto fails

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62077

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #61 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #60)
> Workaround confirmed for GCC 5 (--enable-stage1-checking=release).

So, what about just use the workaround automatically for the default
--enable-stage1-checking (of course, if somebody uses something explicitly, he
is on his own)?
Like:

--- configure.ac.jj    2015-03-27 18:32:41.000000000 +0100
+++ configure.ac    2015-04-17 13:01:30.117314053 +0200
@@ -3482,7 +3482,19 @@ AC_ARG_ENABLE(stage1-checking,
         [choose additional checking for stage1 of the compiler])],
 [stage1_checking=--enable-checking=${enable_stage1_checking}],
 [if test "x$enable_checking" = xno || test "x$enable_checking" = x; then
-  stage1_checking=--enable-checking=yes,types
+  # For --disable-checking or implicit --enable-checking=release, avoid
+  # setting --enable-checking=gc in the default stage1 checking for LTO
+  # bootstraps.  See PR62077.
+  stage1_checking=--enable-checking=release,misc,gimple,rtlflag,tree,types
+  case $BUILD_CONFIG in
+    *lto*)
+      if test "x$enable_checking" = x && \
+     test -d ${srcdir}/gcc && \
+     test x"`cat ${srcdir}/gcc/DEV-PHASE`" = xexperimental; then
+    stage1_checking=--enable-checking=yes,types
+      fi;;
+    *) stage1_checking=--enable-checking=yes,types;;
+  esac
 else
   stage1_checking=--enable-checking=$enable_checking,types
 fi])

I've so far successfully bootstrapped GCC 5 branch with
../configure --prefix=/tmp/blah --with-gnu-as --with-gnu-ld
--enable-languages=all,go --disable-multilib --disable-nls --with-arch=haswell
--with-tune=haswell --with-build-config=bootstrap-lto
--enable-stage1-checking=release,misc,gimple,rtlflag,tree,types
so it indeed is the gc checking that breaks the LTO bootstrap comparison.
release,misc,gimple,rtlflag,tree,types I believe enables everything yes,types
enables, except for gc checking.