re PR bootstrap/45538 (--enable-build-with-cxx compiling gcc/libcpp/charset.c)

	PR bootstrap/45538
	* configure.ac: Use AC_USE_SYSTEM_EXTENSIONS.  Remove switch of
	AC_LANG based on ENABLE_BUILD_WITH_CXX.

From-SVN: r166896

libcpp/ChangeLog

+2010-11-17  Ian Lance Taylor  <iant@google.com>
+
+	PR bootstrap/45538
+	* configure.ac: Use AC_USE_SYSTEM_EXTENSIONS.  Remove switch of
+	AC_LANG based on ENABLE_BUILD_WITH_CXX.
+
 2010-11-16  Kai Tietz  <kai.tietz@onevision.com>
 
 	PR preprocessor/17349

libcpp/config.in

@@ -275,6 +275,28 @@
 /* Define to 1 if your <sys/time.h> declares `struct tm'. */
 #undef TM_IN_SYS_TIME
 
+/* Enable extensions on AIX 3, Interix.  */
+#ifndef _ALL_SOURCE
+# undef _ALL_SOURCE
+#endif
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
+/* Enable threading extensions on Solaris.  */
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# undef _POSIX_PTHREAD_SEMANTICS
+#endif
+/* Enable extensions on HP NonStop.  */
+#ifndef _TANDEM_SOURCE
+# undef _TANDEM_SOURCE
+#endif
+/* Enable general extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# undef __EXTENSIONS__
+#endif
+
+
 /* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
    significant byte first (like Motorola and SPARC, unlike Intel). */
 #if defined AC_APPLE_UNIVERSAL_BUILD
@@ -293,6 +315,16 @@
 /* Define for large files, on AIX-style hosts. */
 #undef _LARGE_FILES
 
+/* Define to 1 if on MINIX. */
+#undef _MINIX
+
+/* Define to 2 if the system does not provide POSIX.1 features except with
+   this defined. */
+#undef _POSIX_1_SOURCE
+
+/* Define to 1 if you need to in order for `stat' and other things to work. */
+#undef _POSIX_SOURCE
+
 /* Define to empty if `const' does not conform to ANSI C. */
 #undef const
 

libcpp/configure.ac

@@ -14,6 +14,7 @@ AC_PROG_CC
 AC_PROG_CXX
 AC_PROG_RANLIB
 
+AC_USE_SYSTEM_EXTENSIONS
 AC_SYS_LARGEFILE
 
 # See if we are building gcc with C++.
@@ -58,18 +59,8 @@ fi
 AC_HEADER_TIME
 ACX_HEADER_STRING
 
-# AC_CHECK_HEADERS is repeated to work around apparent autoconf 2.59 bug.  If
-# AC_CHECK_HEADERS comes after the if clause, the last AC_LANG call gets used,
-# no matter which branch is taken.
-if test "$ENABLE_BUILD_WITH_CXX" = "no"; then
-   AC_LANG(C)
-   AC_CHECK_HEADERS(locale.h fcntl.h limits.h stddef.h \
+AC_CHECK_HEADERS(locale.h fcntl.h limits.h stddef.h \
 	stdlib.h strings.h string.h sys/file.h unistd.h)
-else
-   AC_LANG(C++)
-   AC_CHECK_HEADERS(locale.h fcntl.h limits.h stddef.h \
-	stdlib.h strings.h string.h sys/stat.h sys/file.h unistd.h)
-fi
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_BIGENDIAN