Diagnose class members that shadow a template parameter. Fixes
<rdar://problem/6952203>. 

To do this, we actually remove a not-quite-correct optimization in the
C++ name lookup routines. We'll revisit this optimization for the
general case once more C++ is working.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73659 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 3c6f706..7746035 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3807,6 +3807,14 @@
     Diag(D.getDeclSpec().getThreadSpecLoc(), diag::err_invalid_thread);
 
   NamedDecl *PrevDecl = LookupName(S, II, LookupMemberName, true);
+
+  if (PrevDecl && PrevDecl->isTemplateParameter()) {
+    // Maybe we will complain about the shadowed template parameter.
+    DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
+    // Just pretend that we didn't see the previous declaration.
+    PrevDecl = 0;
+  }
+
   if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
     PrevDecl = 0;
 
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 1d26845..f29cd17 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -685,7 +685,7 @@
       // identifier chain.
       if (isa<RecordDecl>(Ctx)) {
         R = LookupQualifiedName(Ctx, Name, NameKind, RedeclarationOnly);
-        if (R || RedeclarationOnly)
+        if (R)
           return std::make_pair(true, R);
       }
       if (Ctx->getParent() != Ctx->getLexicalParent() 
@@ -697,7 +697,7 @@
         for (OutOfLineCtx = Ctx; OutOfLineCtx && !OutOfLineCtx->isFileContext();
              OutOfLineCtx = OutOfLineCtx->getParent()) {
           R = LookupQualifiedName(OutOfLineCtx, Name, NameKind, RedeclarationOnly);
-          if (R || RedeclarationOnly)
+          if (R)
             return std::make_pair(true, R);
         }
       }
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 0ae9f1d..fb41b2b 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -444,6 +444,9 @@
   if (Previous.begin() != Previous.end())
     PrevDecl = *Previous.begin();
 
+  if (PrevDecl && !isDeclInScope(PrevDecl, CurContext, S))
+    PrevDecl = 0;
+  
   DeclContext *SemanticContext = CurContext;
   if (SS.isNotEmpty() && !SS.isInvalid()) {
     SemanticContext = computeDeclContext(SS);
diff --git a/test/Parser/cxx-template-decl.cpp b/test/Parser/cxx-template-decl.cpp
index ae5d8f9..75b26a9 100644
--- a/test/Parser/cxx-template-decl.cpp
+++ b/test/Parser/cxx-template-decl.cpp
@@ -66,6 +66,17 @@
 template<int Size> // expected-note{{template parameter is declared here}}
 void shadow3(int Size); // expected-error{{declaration of 'Size' shadows template parameter}}
 
+// <rdar://problem/6952203>
+template<typename T> // expected-note{{here}}
+struct shadow4 {
+  int T; // expected-error{{shadows}}
+};
+
+template<typename T> // expected-note{{here}}
+struct shadow5 {
+  int T(int, float); // expected-error{{shadows}}
+};
+
 // Non-type template parameters in scope
 template<int Size> 
 void f(int& i) {
diff --git a/test/SemaTemplate/nested-template.cpp b/test/SemaTemplate/nested-template.cpp
index bd9e89f..84b1d35 100644
--- a/test/SemaTemplate/nested-template.cpp
+++ b/test/SemaTemplate/nested-template.cpp
@@ -1,4 +1,4 @@
-// RUN: clang-cc -fsyntax-only %s
+// RUN: clang-cc -fsyntax-only -verify %s
 
 class A;