Fix an assertion failure / accepts-invalid in -fms-extensions mode. Don't build

a dependent-scope id expression when a templated member function of a
non-templated class references an unknown identifier, since instantiation won't
rebuild it (and we can tell at parse time that it'll never work). Based on a
patch by Faisal Vali!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180701 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 35 insertions, 9 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index a0e6c2144e..f5900c06c7 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1916,15 +1916,17 @@ ExprResult Sema::ActOnIdExpression(Scope *S,
     // If this name wasn't predeclared and if this is not a function
     // call, diagnose the problem.
     if (R.empty()) {
-
       // In Microsoft mode, if we are inside a template class member function
-      // and we can't resolve an identifier then assume the identifier is type
-      // dependent. The goal is to postpone name lookup to instantiation time 
-      // to be able to search into type dependent base classes.
-      if (getLangOpts().MicrosoftMode && CurContext->isDependentContext() &&
-          isa<CXXMethodDecl>(CurContext))
-        return ActOnDependentIdExpression(SS, TemplateKWLoc, NameInfo,
-                                          IsAddressOfOperand, TemplateArgs);
+      // whose parent class has dependent base classes, and we can't resolve
+      // an identifier, then assume the identifier is type dependent.  The
+      // goal is to postpone name lookup to instantiation time to be able to
+      // search into the type dependent base classes.
+      if (getLangOpts().MicrosoftMode) {
+        CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext);
+        if (MD && MD->getParent()->hasAnyDependentBases())
+          return ActOnDependentIdExpression(SS, TemplateKWLoc, NameInfo,
+                                            IsAddressOfOperand, TemplateArgs);
+      }
 
       CorrectionCandidateCallback DefaultValidator;
       if (DiagnoseEmptyLookup(S, SS, R, CCC ? *CCC : DefaultValidator))
diff --git a/test/SemaTemplate/ms-lookup-template-base-classes.cpp b/test/SemaTemplate/ms-lookup-template-base-classes.cpp
index 8f80cb59e8..cb1a7f50b7 100644
--- a/test/SemaTemplate/ms-lookup-template-base-classes.cpp
+++ b/test/SemaTemplate/ms-lookup-template-base-classes.cpp
@@ -8,7 +8,6 @@ public:
    void g();// expected-note {{must qualify identifier to find this declaration in dependent base class}}
 };
 
-
 template <class T>
 class B : public A<T> {
 public:
@@ -28,6 +27,31 @@ void test()
     b.z(3);
 }
 
+struct A2 {
+  template<class T> void f(T) {
+    XX; //expected-error {{use of undeclared identifier 'XX'}}
+    A2::XX; //expected-error {{no member named 'XX' in 'A2'}}
+  }
+};
+template void A2::f(int);
+
+template<class T0>
+struct A3 {
+  template<class T1> void f(T1) {
+    XX; //expected-error {{use of undeclared identifier 'XX'}}
+  }
+};
+template void A3<int>::f(int);
+
+template<class T0>
+struct A4 {
+  void f(char) {
+    XX; //expected-error {{use of undeclared identifier 'XX'}}
+  }
+};
+template class A4<int>;
+
+
 namespace lookup_dependent_bases_id_expr {
 
 template<class T> class A {