Fix validation of the -mthread-model flag in the Clang driver

[itessier]

Summary

The ToolChain class validates the -mthread-model flag in the constructor which doesn't work correctly since the thread model methods are virtual methods. The check is moved into Clang::ConstructJob() when constructing the internal command line.

[compnerd]

The change looks good. Can you please add some test cases for this? Or do existing test cases cover this already?

[itessier]

In D37496#861746, @compnerd wrote:

The change looks good. Can you please add some test cases for this? Or do existing test cases cover this already?

Should have added this to the description, but yes there are existing tests that cover this flag (test/Driver/thread-model.c). D37493 removes the only overridden thread model methods so we can't test the fix in this CL.

[itessier]

Do you mind submitting this CL? I don't have access to SVN.

[jroelofs]

r312748

lib/Driver/ToolChain.cpp

     : D(D), Triple(T), Args(Args), CachedRTTIArg(GetRTTIArgument(Args)),
       CachedRTTIMode(CalculateRTTIMode(Args, Triple, CachedRTTIArg)),
       EffectiveTriple() {
-  if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
-    if (!isThreadModelSupported(A->getValue()))
-      D.Diag(diag::err_drv_invalid_thread_model_for_target)
-          << A->getValue() << A->getAsString(Args);
-
   std::string CandidateLibPath = getArchSpecificLibPath();
   if (getVFS().exists(CandidateLibPath))
     getFilePaths().push_back(CandidateLibPath);

lib/Driver/ToolChains/Clang.cpp

   }
 
   CmdArgs.push_back("-mthread-model");
-  if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
+  if (Arg *A = Args.getLastArg(options::OPT_mthread_model)) {
+    if (!getToolChain().isThreadModelSupported(A->getValue()))
+      D.Diag(diag::err_drv_invalid_thread_model_for_target)
+          << A->getValue() << A->getAsString(Args);
     CmdArgs.push_back(A->getValue());
+  }
   else
     CmdArgs.push_back(Args.MakeArgString(getToolChain().getThreadModel()));