configure.ac: enable C++ warnings

configure.ac

@@ -21,7 +21,6 @@ dnl Programs
 dnl ---------------------------------------------------------------------------
 AC_PROG_CC_C99
 AC_PROG_CXX
-AC_CXX_COMPILE_STDCXX_0X
 AC_PROG_RANLIB
 
 AC_PROG_INSTALL
@@ -110,6 +109,19 @@ if test -z "$prefix" || test "x$prefix" = xNONE; then
 	done
 fi
 
+dnl ---------------------------------------------------------------------------
+dnl Language Checks
+dnl ---------------------------------------------------------------------------
+
+AC_CXX_COMPILE_STDCXX_0X
+if test "$ax_cv_cxx_compile_cxx0x_native" != yes; then
+	if test "$ax_cv_cxx_compile_cxx0x_gxx" = yes; then
+	   	AM_CXXFLAGS="$AM_CXXFLAGS -std=gnu++0x"
+	elif test "$ax_cv_cxx_compile_cxx0x_cxx" = yes; then
+	   	AM_CXXFLAGS="$AM_CXXFLAGS -std=c++0x"
+	fi
+fi
+
 dnl ---------------------------------------------------------------------------
 dnl Header/Library Checks
 dnl ---------------------------------------------------------------------------
@@ -1487,6 +1499,17 @@ then
 	AX_APPEND_COMPILE_FLAGS([-Wcast-qual])
 	AX_APPEND_COMPILE_FLAGS([-Wwrite-strings])
 	AX_APPEND_COMPILE_FLAGS([-pedantic])
+
+	AC_LANG_PUSH([C++])
+	AX_APPEND_COMPILE_FLAGS([-Wall])
+	AX_APPEND_COMPILE_FLAGS([-Wextra])
+	AX_APPEND_COMPILE_FLAGS([-Wmissing-declarations])
+	AX_APPEND_COMPILE_FLAGS([-Wshadow])
+	AX_APPEND_COMPILE_FLAGS([-Wpointer-arith])
+	AX_APPEND_COMPILE_FLAGS([-Wcast-qual])
+	AX_APPEND_COMPILE_FLAGS([-Wwrite-strings])
+	AX_APPEND_COMPILE_FLAGS([-Wsign-compare])
+	AC_LANG_POP
 fi
 
 dnl ---------------------------- warnings as errors ---------------------------