[patch] Fix PR bootstrap/54820

[Eric Botcazou]

Hi,

native compilers are now built with -static-libstdc++ -static-libgcc (if 
bootstrapped) because the switches are added to LDFLAGS during stage 2 and 3.
Nothing is done for stage 1 or cross-compilers, except for Ada where we force 
the switches, but this is far from ideal as reported under the PR.

The attached patch enables -static-libstdc++ -static-libgcc for stage 1 and 
cross-compilers if g++ is detected and the switches work, using the same idea 
as for later stages (i.e. setting --with-stage1-ldflags if not already set).
It turns out that --with-stage1-ldflags is currently broken: LDFLAGS is 
correctly passed and set in gcc/ at configure time during stage 1, but a 
'make' invocation from the toplevel passes an empty LDFLAGS to gcc/.

Tested on x86_64-suse-linux, OK for the mainline?


2012-10-09  Eric Botcazou  <ebotca...@adacore.com>

        PR bootstrap/54820
        * Makefile.tpl (STAGE1_FLAGS_TO_PASS): New variable.
        (host_modules): Add STAGE1_FLAGS_TO_PASS to args.
        * Makefile.in: Regenerate.
        * configure.ac (have_static_libs): New variable and associated check.
        (stage1-ldflags): Move to after stage1_libs and set to -static-libstdc++
        -static-libgcc if stage1_libs is empty and have_static_libs is yes.
        * configure: Regenerate.
gcc/ada
        * gcc-interface/Make-lang.in (GCC_LINK): Remove -static-libstdc++
        -static-libgcc.


-- 
Eric Botcazou
Index: Makefile.tpl
===================================================================
--- Makefile.tpl	(revision 192137)
+++ Makefile.tpl	(working copy)
@@ -615,6 +615,12 @@ EXTRA_HOST_FLAGS = \
 
 FLAGS_TO_PASS = $(BASE_FLAGS_TO_PASS) $(EXTRA_HOST_FLAGS)
 
+# Flags to pass to stage1 or when not bootstrapping.
+
+STAGE1_FLAGS_TO_PASS = \
+	LDFLAGS="$${LDFLAGS}" \
+	HOST_LIBS="$${HOST_LIBS}"
+
 # Flags to pass to stage2 and later makes.
 
 POSTSTAGE1_FLAGS_TO_PASS = \
@@ -1161,7 +1167,7 @@ clean-stage[+id+]-[+prefix+][+module+]:
 [+ all prefix="" subdir="$(HOST_SUBDIR)"
        exports="$(HOST_EXPORTS)"
        poststage1_exports="$(POSTSTAGE1_HOST_EXPORTS)"
-       args="$(EXTRA_HOST_FLAGS)"
+       args="$(EXTRA_HOST_FLAGS) $(STAGE1_FLAGS_TO_PASS)"
        poststage1_args="$(POSTSTAGE1_FLAGS_TO_PASS)" +]
 
 .PHONY: check-[+module+] maybe-check-[+module+]
Index: configure.ac
===================================================================
--- configure.ac	(revision 192137)
+++ configure.ac	(working copy)
@@ -1182,6 +1182,22 @@ if test -z "$LD"; then
   fi
 fi
 
+# Check whether -static-libstdc++ -static-libgcc is supported
+have_static_libs=no
+if test "$GCC" = yes; then
+  saved_LDFLAGS="$LDFLAGS"
+
+  LDFLAGS="$LDFLAGS -static-libstdc++ -static-libgcc"
+  AC_MSG_CHECKING([whether g++ accepts -static-libstdc++ -static-libgcc])
+  AC_LANG_PUSH(C++)
+  AC_LINK_IFELSE([int main() {}],
+    [AC_MSG_RESULT([yes]); have_static_libs=yes],
+    [AC_MSG_RESULT([no])])
+  AC_LANG_POP(C++)
+
+  LDFLAGS="$saved_LDFLAGS"
+fi
+
 ACX_PROG_GNAT
 ACX_PROG_CMP_IGNORE_INITIAL
 
@@ -1478,17 +1494,6 @@ case $with_host_libstdcxx in
     ;;
 esac
 
-# Linker flags to use for stage1 or when not boostrapping.
-AC_ARG_WITH(stage1-ldflags,
-[AS_HELP_STRING([--with-stage1-ldflags=FLAGS], [linker flags for stage1])],
-[if test "$withval" = "no" -o "$withval" = "yes"; then
-   stage1_ldflags=
- else
-   stage1_ldflags=$withval
- fi],
-[stage1_ldflags=])
-AC_SUBST(stage1_ldflags)
-
 # Libraries to use for stage1 or when not bootstrapping.
 AC_ARG_WITH(stage1-libs,
 [AS_HELP_STRING([--with-stage1-libs=LIBS], [libraries for stage1])],
@@ -1500,6 +1505,23 @@ AC_ARG_WITH(stage1-libs,
 [stage1_libs=$with_host_libstdcxx])
 AC_SUBST(stage1_libs)
 
+# Linker flags to use for stage1 or when not bootstrapping.
+AC_ARG_WITH(stage1-ldflags,
+[AS_HELP_STRING([--with-stage1-ldflags=FLAGS], [linker flags for stage1])],
+[if test "$withval" = "no" -o "$withval" = "yes"; then
+   stage1_ldflags=
+ else
+   stage1_ldflags=$withval
+ fi],
+[stage1_ldflags=
+ # In stage 1, default to linking libstdc++ and libgcc statically with GCC
+ # if supported.  But if the user explicitly specified the libraries to use,
+ # trust that they are doing what they want.
+ if test "$stage1_libs" = "" -a "$have_static_libs" = yes; then
+   stage1_ldflags="-static-libstdc++ -static-libgcc"
+ fi])
+AC_SUBST(stage1_ldflags)
+
 # Libraries to use for stage2 and later builds.  This defaults to the
 # argument passed to --with-host-libstdcxx.
 AC_ARG_WITH(boot-libs,
Index: gcc/ada/gcc-interface/Make-lang.in
===================================================================
--- gcc/ada/gcc-interface/Make-lang.in	(revision 192137)
+++ gcc/ada/gcc-interface/Make-lang.in	(working copy)
@@ -172,7 +172,7 @@ endif
 # Strip -Werror during linking for the LTO bootstrap
 GCC_LINKERFLAGS = $(filter-out -Werror, $(ALL_LINKERFLAGS))
 
-GCC_LINK=$(LINKER) $(GCC_LINKERFLAGS) -static-libgcc -static-libstdc++ $(LDFLAGS)
+GCC_LINK=$(LINKER) $(GCC_LINKERFLAGS) $(LDFLAGS)
 
 # Lists of files for various purposes.