configure.in: Test the ability to symlink directories.

2005-05-24  Paolo Bonzini <bonzini@gnu.org>

	* configure.in: Test the ability to symlink directories.
	* configure: Regenerate.

	* Makefile.def (bootstrap-stage): New definitions.
	* Makefile.tpl (configure-stage1-gcc,
	configure-stage2-gcc, configure-stage3-gcc,
	all-stage1-gcc, all-stage2-gcc, all-stage3-gcc,
	new-bootstrap, new-cleanstrap, new-restage1, new-restage2,
	new-restage3, compare): Autogenerate, see Makefile.in
	entry for behavioral changes.
	(distclean-stage1, new-stage1-start, new-stage1-end,
	new-stage1-bubble, distclean-stage2, new-stage2-start,
	new-stage2-end, new-stage2-bubble, distclean-stage3,
	new-stage3-start, new-stage3-end): New autogenerated targets.
	(objext, prebootstrap, BOOT_CFLAGS,
	POSTSTAGE1_FLAGS_TO_PASS): Move above the autogenerated
	targets.

	* Makefile.in: Regenerate.
	(distclean-stage1, new-stage1-start, new-stage1-end,
	new-stage1-bubble, distclean-stage2, new-stage2-start,
	new-stage2-end, new-stage2-bubble, distclean-stage3,
	new-stage3-start, new-stage3-end): New targets.
	(all-stage1-gcc): Move prebootstrap dependency from here...
	(configure-stage1-gcc): ...to here.
	(new-bootstrap): Use bubble targets.
	(new-cleanstrap, new-restage1, new-restage2, new-restage3):
	Use per-stage distclean targets.
	(configure-stage1-gcc, configure-stage2-gcc,
	configure-stage3-gcc, all-stage1-gcc,
	all-stage2-gcc, all-stage3-gcc, new-bootstrap):
	Use new-stageN-start to prepare the tree.

From-SVN: r82200

ChangeLog

+2005-05-24  Paolo Bonzini <bonzini@gnu.org>
+
+	* configure.in: Test the ability to symlink directories.
+	* configure: Regenerate.
+
+	* Makefile.def (bootstrap-stage): New definitions.
+	* Makefile.tpl (configure-stage1-gcc,
+	configure-stage2-gcc, configure-stage3-gcc,
+	all-stage1-gcc, all-stage2-gcc, all-stage3-gcc,
+	new-bootstrap, new-cleanstrap, new-restage1, new-restage2,
+	new-restage3, compare): Autogenerate, see Makefile.in
+	entry for behavioral changes.
+	(distclean-stage1, new-stage1-start, new-stage1-end,
+	new-stage1-bubble, distclean-stage2, new-stage2-start,
+	new-stage2-end, new-stage2-bubble, distclean-stage3,
+	new-stage3-start, new-stage3-end): New autogenerated targets.
+	(objext, prebootstrap, BOOT_CFLAGS,
+	POSTSTAGE1_FLAGS_TO_PASS): Move above the autogenerated
+	targets.
+
+	* Makefile.in: Regenerate.
+	(distclean-stage1, new-stage1-start, new-stage1-end,
+	new-stage1-bubble, distclean-stage2, new-stage2-start,
+	new-stage2-end, new-stage2-bubble, distclean-stage3,
+	new-stage3-start, new-stage3-end): New targets.
+	(all-stage1-gcc): Move prebootstrap dependency from here...
+	(configure-stage1-gcc): ...to here.
+	(new-bootstrap): Use bubble targets.
+	(new-cleanstrap, new-restage1, new-restage2, new-restage3):
+	Use per-stage distclean targets.
+	(configure-stage1-gcc, configure-stage2-gcc,
+	configure-stage3-gcc, all-stage1-gcc,
+	all-stage2-gcc, all-stage3-gcc, new-bootstrap):
+	Use new-stageN-start to prepare the tree.
+
 2004-05-23  Paolo Bonzini  <bonzini@gnu.org>
 
 	* Makefile.def (host_modules): add libcpp.

Makefile.def

@@ -213,3 +213,21 @@ flags_to_pass = { flag= LIBCXXFLAGS_FOR_TARGET ; };
 flags_to_pass = { flag= NM_FOR_TARGET ; };
 flags_to_pass = { flag= RANLIB_FOR_TARGET ; };
 flags_to_pass = { flag= WINDRES_FOR_TARGET ; };
+
+// Toplevel bootstrap
+bootstrap_stage = {
+	id=1 ; next=2 ;
+	extra_configure_flags='--disable-intermodule \
+	  --disable-coverage --enable-languages="$(STAGE1_LANGUAGES)"' ;
+	extra_make_flags='CFLAGS="$(STAGE1_CFLAGS)"' ; };
+bootstrap_stage = {
+	id=2 ; prev=1 ; next=3 ;
+	extra_configure_flags="@stage2_werror_flag@" ;
+	extra_make_flags="$(POSTSTAGE1_FLAGS_TO_PASS)" ; };
+bootstrap_stage = {
+	id=3 ; prev=2 ;
+	compare_target=compare ;
+	bootstrap_target=new-bootstrap ;
+	cleanstrap_target=new-cleanstrap ;
+	extra_configure_flags="@stage2_werror_flag@" ;
+	extra_make_flags="$(POSTSTAGE1_FLAGS_TO_PASS)" ; };

configure.in

@@ -25,6 +25,7 @@ AC_ARG_PROGRAM
 
 # Get 'install' or 'install-sh' and its variants.
 AC_PROG_INSTALL
+AC_PROG_LN_S
 
 sinclude(config/acx.m4)
 
@@ -2247,6 +2248,36 @@ case $build in
 esac
 AC_SUBST(stage1_cflags)
 
+# It makes debugging easier if we create as symlinks the stage directories
+# gcc for stageN-gcc and stage-prev for stage(N-1).  In case this is not
+# possible, however, we can resort to mv.
+AC_CACHE_CHECK([if symbolic links between directories work],
+[gcc_cv_prog_ln_s_dir],
+[if test "${LN_S}" = "ln -s" \
+   && mkdir confdir.s1 \
+   && ln -s confdir.s1 confdir.s2 \
+   && echo timestamp1 > confdir.s1/conftest.1 \
+   && cmp confdir.s1/conftest.1 confdir.s2/conftest.1 \
+   && echo timestamp2 > confdir.s2/conftest.2 \
+   && cmp confdir.s1/conftest.2 confdir.s1/conftest.2 \
+   && rm -f confdir.s2; then
+  gcc_cv_prog_ln_s_dir=yes
+else
+  gcc_cv_prog_ln_s_dir=yes
+fi
+rm -rf confdir.s1 confdir.s2])
+
+case ${gcc_cv_prog_ln_s_dir} in
+  yes)
+    CREATE_LINK_TO_DIR='ln -s $$1 $$2'
+    UNDO_LINK_TO_DIR='rm -f $$1' ;;
+  *)
+    CREATE_LINK_TO_DIR='mv $$1 $$2'
+    UNDO_LINK_TO_DIR='mv $$1 $$2' ;;
+esac
+AC_SUBST(CREATE_LINK_TO_DIR)
+AC_SUBST(UNDO_LINK_TO_DIR)
+
 # Enable -Werror in bootstrap stage2 and later.
 # Change the default to "no" on release branches.
 AC_ARG_ENABLE(werror,