PR16933: Don't try to codegen things after we've seen errors.

Refactor the underlying code a bit to remove unnecessary calls to
"hasErrorOccurred" & make them consistently at all the entry points to
the IRGen ASTConsumer.

llvm-svn: 188707

clang/lib/CodeGen/ModuleBuilder.cpp

@@ -66,10 +66,16 @@ namespace {
     }
 
     virtual void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
+      if (Diags.hasErrorOccurred())
+        return;
+
       Builder->HandleCXXStaticMemberVarInstantiation(VD);
     }
 
     virtual bool HandleTopLevelDecl(DeclGroupRef DG) {
+      if (Diags.hasErrorOccurred())
+        return true;
+
       // Make sure to emit all elements of a Decl.
       for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
         Builder->EmitTopLevelDecl(*I);
@@ -81,6 +87,9 @@ namespace {
     /// client hack on the type, which can occur at any point in the file
     /// (because these can be defined in declspecs).
     virtual void HandleTagDeclDefinition(TagDecl *D) {
+      if (Diags.hasErrorOccurred())
+        return;
+
       Builder->UpdateCompletedType(D);
       
       // In C++, we may have member functions that need to be emitted at this 
@@ -98,6 +107,9 @@ namespace {
     }
 
     virtual void HandleTagDeclRequiredDefinition(const TagDecl *D) LLVM_OVERRIDE {
+      if (Diags.hasErrorOccurred())
+        return;
+
       if (CodeGen::CGDebugInfo *DI = Builder->getModuleDebugInfo())
         if (const RecordDecl *RD = dyn_cast<RecordDecl>(D))
           DI->completeRequiredType(RD);