Add Driver support for -fno-constant-cfstrings.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102431 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Driver/Options.td

@@ -248,7 +248,7 @@ def fclasspath_EQ : Joined<"-fclasspath=">, Group<f_Group>;
 def fcolor_diagnostics : Flag<"-fcolor-diagnostics">, Group<f_Group>;
 def fcommon : Flag<"-fcommon">, Group<f_Group>;
 def fcompile_resource_EQ : Joined<"-fcompile-resource=">, Group<f_Group>;
-def fconstant_cfstrings : Flag<"-fconstant-cfstrings">, Group<clang_ignored_f_Group>;
+def fconstant_cfstrings : Flag<"-fconstant-cfstrings">, Group<f_Group>;
 def fconstant_string_class_EQ : Joined<"-fconstant-string-class=">, Group<f_Group>;
 def fcreate_profile : Flag<"-fcreate-profile">, Group<f_Group>;
 def fdebug_pass_arguments : Flag<"-fdebug-pass-arguments">, Group<f_Group>;

lib/Driver/Tools.cpp

@@ -1248,6 +1248,14 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                     options::OPT_fno_assume_sane_operator_new))
     CmdArgs.push_back("-fno-assume-sane-operator-new");
 
+  // -fconstant-cfstrings is default, and may be subject to argument translation
+  // on Darwin.
+  if (!Args.hasFlag(options::OPT_fconstant_cfstrings,
+                    options::OPT_fno_constant_cfstrings) ||
+      !Args.hasFlag(options::OPT_mconstant_cfstrings,
+                    options::OPT_mno_constant_cfstrings))
+    CmdArgs.push_back("-fno-constant-cfstrings");
+
   // -fshort-wchar default varies depending on platform; only
   // pass if specified.
   if (Arg *A = Args.getLastArg(options::OPT_fshort_wchar)) {