Check and enable -Wshadow by default.

paveljanik · paveljanik · commit fd5654cab1e5 · 2016-09-22T16:36:03.000+02:00
diff --git a/configure.ac b/configure.ac
@@ -203,6 +203,7 @@ if test "x$CXXFLAGS_overridden" = "xno"; then
   AX_CHECK_COMPILE_FLAG([-Wextra],[CXXFLAGS="$CXXFLAGS -Wextra"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wformat],[CXXFLAGS="$CXXFLAGS -Wformat"],,[[$CXXFLAG_WERROR]])
   AX_CHECK_COMPILE_FLAG([-Wformat-security],[CXXFLAGS="$CXXFLAGS -Wformat-security"],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_COMPILE_FLAG([-Wshadow],[CXXFLAGS="$CXXFLAGS -Wshadow"],,[[$CXXFLAG_WERROR]])
 
   ## Some compilers (gcc) ignore unknown -Wno-* options, but warn about all
   ## unknown options if any other warning is produced. Test the -Wfoo case, and
