In Microsoft mode, make "Unqualified lookup into dependent bases of class templates" works inside a friend function definition at class scope.

Basically we have to look into the parent *lexical* DeclContext for friend functions at class scope. That's because calling GetParent() return the namespace or file DeclContext.

This fixes all remaining cases of "Unqualified lookup into dependent bases of class templates" when parsing MFC code with clang.

llvm-svn: 145127

3 files changed, 40 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ef9d787fe43..e6e6e5f5e1e 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -1511,8 +1511,8 @@ bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
   // unqualified lookup.  This is useful when (for example) the
   // original lookup would not have found something because it was a
   // dependent name.
-  for (DeclContext *DC = SS.isEmpty() ? CurContext : 0;
-       DC; DC = DC->getParent()) {
+  DeclContext *DC = SS.isEmpty() ? CurContext : 0;
+  while (DC) {
     if (isa<CXXRecordDecl>(DC)) {
       LookupQualifiedName(R, DC);
 
@@ -1591,6 +1591,17 @@ bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
 
       R.clear();
     }
+
+    // In Microsoft mode, if we are performing lookup from within a friend
+    // function definition declared at class scope then we must set
+    // DC to the lexical parent to be able to search into the parent
+    // class.
+    if (getLangOptions().MicrosoftMode && DC->isFunctionOrMethod() &&
+        cast<FunctionDecl>(DC)->getFriendObjectKind() &&
+        DC->getLexicalParent()->isRecord())
+      DC = DC->getLexicalParent();
+    else
+      DC = DC->getParent();
   }
 
   // We didn't find anything, so try to correct for a typo.
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 9b605c9319d..b54f1a30ab1 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -8825,7 +8825,7 @@ Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
     // to instantiation time to be able to search into type dependent base
     // classes.
     if (getLangOptions().MicrosoftMode && CurContext->isDependentContext() && 
-        (isa<CXXMethodDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
+        (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
       CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, NumArgs,
                                           Context.DependentTy, VK_RValue,
                                           RParenLoc);
diff --git a/clang/test/SemaTemplate/ms-lookup-template-base-classes.cpp b/clang/test/SemaTemplate/ms-lookup-template-base-classes.cpp
index cc5edf7997a..901f104ec36 100644
--- a/clang/test/SemaTemplate/ms-lookup-template-base-classes.cpp
+++ b/clang/test/SemaTemplate/ms-lookup-template-base-classes.cpp
@@ -97,4 +97,29 @@ void foo()
 	b.g2(); // expected-note {{required here}}
 }
 
-}
\ No newline at end of file
+}
+
+
+namespace lookup_dependent_base_class_friend {
+
+template <class T>
+class B {
+public:
+  static void g();  // expected-note {{must qualify identifier to find this declaration in dependent base class}} 
+};
+
+template <class T>
+class A : public B<T> {
+public:
+  friend void foo(A<T> p){
+    g(); // expected-warning {{use of identifier 'g' found via unqualified lookup into dependent bases of class templates is a Microsoft extension}}
+  }
+};
+
+int main2()
+{
+  A<int> a;
+  foo(a); // expected-note {{requested here}}
+}
+
+}