Silence the -Wshadow warning for enumerators shadowing a type.

Amends r344259 so that enumerators shadowing types are not diagnosed, as shadowing under those circumstances is rarely (if ever) an issue in practice.

llvm-svn: 344898

clang/lib/Sema/SemaDecl.cpp

@@ -16295,7 +16295,7 @@ Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst,
     return nullptr;
 
   if (PrevDecl) {
-    if (!TheEnumDecl->isScoped()) {
+    if (!TheEnumDecl->isScoped() && isa<ValueDecl>(PrevDecl)) {
       // Check for other kinds of shadowing not already handled.
       CheckShadow(New, PrevDecl, R);
     }

clang/test/Sema/warn-shadow.c

@@ -64,3 +64,10 @@ enum PR24718_1{pr24718}; // expected-note {{previous declaration is here}}
 void PR24718(void) {
   enum PR24718_2{pr24718}; // expected-warning {{declaration shadows a variable in the global scope}}
 }
+
+struct PR24718_3;
+struct PR24718_4 {
+  enum {
+    PR24718_3 // Does not shadow a type.
+  };
+};

clang/test/SemaCXX/warn-shadow.cpp

@@ -225,3 +225,10 @@ void f(int a) {
 
 int PR24718;
 enum class X { PR24718 }; // Ok, not shadowing
+
+struct PR24718_1;
+struct PR24718_2 {
+  enum {
+    PR24718_1 // Does not shadow a type.
+  };
+};