re PR bootstrap/46810 (sparc64-linux bootstrap fails with "C++ preprocessor…

re PR bootstrap/46810 (sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check")

	PR bootstrap/46810
	* configure.ac: Disable AC_MSG_ERROR while looking for the C++
	preprocessor.
	* configure: Rebuild.

Co-Authored-By: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

From-SVN: r167572

gcc/ChangeLog

+2010-12-07  Ian Lance Taylor  <iant@google.com>
+	    Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
+
+	PR bootstrap/46810
+	* configure.ac: Disable AC_MSG_ERROR while looking for the C++
+	preprocessor.
+	* configure: Rebuild.
+
 2010-12-07  Paul Koning  <ni1d@arrl.net>
 
 	* config/pdp11/pdp11.c (output_addr_const_pdp11): Output negative

gcc/configure

@@ -8433,14 +8433,6 @@ ac_cpp='$CXXCPP $CPPFLAGS'
 ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-
-
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking how to run the C++ preprocessor" >&5
 $as_echo_n "checking how to run the C++ preprocessor... " >&6; }
 if test -z "$CXXCPP"; then
@@ -8559,10 +8551,19 @@ if $ac_preproc_ok; then :
 else
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error "C++ preprocessor \"$CXXCPP\" fails sanity check
-See \`config.log' for more details." "$LINENO" 5; }
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: C++ preprocessor \"$CXXCPP\" fails sanity check
+See \`config.log' for more details." >&5
+$as_echo "$as_me: WARNING: C++ preprocessor \"$CXXCPP\" fails sanity check
+See \`config.log' for more details." >&2;}; }
 fi
 
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
 ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
 ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -8570,6 +8571,8 @@ ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ex
 ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 
 
+
+
 for ac_header in unordered_map
 do :
   ac_fn_cxx_check_header_preproc "$LINENO" "unordered_map" "ac_cv_header_unordered_map"
@@ -17506,7 +17509,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 17509 "configure"
+#line 17512 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -17612,7 +17615,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 17615 "configure"
+#line 17618 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H

gcc/configure.ac

@@ -913,6 +913,12 @@ AC_C_BIGENDIAN
 # Checks for C++ headers
 # ----------------------
 
+dnl Autoconf will give an error in the configure script if there is no
+dnl C++ preprocessor.  Hack to prevent that.
+m4_pushdef([AC_MSG_ERROR], m4_defn([AC_MSG_WARN]))[]dnl
+AC_PROG_CXXCPP
+m4_popdef([AC_MSG_ERROR])[]dnl
+
 AC_LANG_PUSH(C++)
 
 AC_CHECK_HEADERS(unordered_map)