1 files changed, 15 insertions, 2 deletions
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index be79e79fd0..6a74ff4743 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1107,10 +1107,23 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                     options::OPT_fno_lax_vector_conversions))
     CmdArgs.push_back("-fno-lax-vector-conversions");
 
+  // Handle -fobjc-gc and -fobjc-gc-only. They are exclusive, and -fobjc-gc-only
+  // takes precedence.
+  const Arg *GCArg = Args.getLastArg(options::OPT_fobjc_gc_only);
+  if (!GCArg)
+    GCArg = Args.getLastArg(options::OPT_fobjc_gc);
+  if (GCArg) {
+    if (getToolChain().SupportsObjCGC()) {
+      GCArg->render(Args, CmdArgs);
+    } else {
+      // FIXME: We should move this to a hard error.
+      D.Diag(clang::diag::warn_drv_objc_gc_unsupported)
+        << GCArg->getAsString(Args);
+    }
+  }
+
   Args.AddLastArg(CmdArgs, options::OPT_fno_caret_diagnostics);
   Args.AddLastArg(CmdArgs, options::OPT_fno_show_column);
-  Args.AddLastArg(CmdArgs, options::OPT_fobjc_gc_only);
-  Args.AddLastArg(CmdArgs, options::OPT_fobjc_gc);
   Args.AddLastArg(CmdArgs, options::OPT_fobjc_sender_dependent_dispatch);
   Args.AddLastArg(CmdArgs, options::OPT_fdiagnostics_print_source_range_info);
   Args.AddLastArg(CmdArgs, options::OPT_ftime_report);