[driver] Don't blindly accept all -g options.
rdar://10383444

llvm-svn: 143732
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 4f84d0a..8c0382f 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1455,8 +1455,24 @@
   // wrong.
   Args.ClaimAllArgs(options::OPT_g_Group);
   if (Arg *A = Args.getLastArg(options::OPT_g_Group))
-    if (!A->getOption().matches(options::OPT_g0))
-      CmdArgs.push_back("-g");
+    if (!A->getOption().matches(options::OPT_g0)) {
+      StringRef ArgString = A->getAsString(Args);
+      bool Valid_g = llvm::StringSwitch<bool>(ArgString)
+        .Case("-g", true)
+        .Case("-g3", true)
+        .Case("-gdwarf-2", true)
+        .Case("-gstabs", true)
+        .Case("-gstabs+", true)
+        .Case("-gstabs1", true)
+        .Case("-gstabs2", true)
+        .Case("-gfull", true)
+        .Case("-gused", true)
+        .Default(false);
+      if (Valid_g)
+        CmdArgs.push_back("-g");
+      else
+        D.Diag(diag::warn_drv_clang_unsupported) << ArgString;
+    }
 
   Args.AddAllArgs(CmdArgs, options::OPT_ffunction_sections);
   Args.AddAllArgs(CmdArgs, options::OPT_fdata_sections);