Remove warning about shadowing a built-in; built-ins aren't actually

considered to be a part of the translation unit unless they're named
in a way that brings them into existence.

llvm-svn: 98729

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -113,8 +113,7 @@ def warn_decl_shadow :
           "local variable|"
           "variable in %2|"
           "static data member of %2|"
-          "field of %2|"
-          "global built-in function}1">,
+          "field of %2}1">,
   InGroup<Shadow>, DefaultIgnore;
 
 // C++ using declarations

clang/lib/Sema/SemaDecl.cpp

@@ -2482,16 +2482,8 @@ void Sema::DiagnoseShadow(NamedDecl* D, const LookupResult& R) {
   DeclarationName Name = D->getDeclName();
 
   // Return if lookup has no result.
-  if (R.getResultKind() != LookupResult::Found) {
-    // Emit warning for built-in shadowing.
-    if (Name.getAsIdentifierInfo() &&
-        Name.getAsIdentifierInfo()->getBuiltinID())
-      Diag(D->getLocation(), diag::warn_decl_shadow)
-        << Name
-        << 4 // global builtin
-        << Context.getTranslationUnitDecl();
+  if (R.getResultKind() != LookupResult::Found)
     return;
-  }
 
   // Return if not variable decl.
   NamedDecl* ShadowedDecl = R.getFoundDecl();

clang/test/Sema/warn-shadow.c

@@ -16,5 +16,5 @@ void foo() {
     }
   }
 
-  int __sync_fetch_and_add; // expected-warning {{declaration shadows a global built-in function}}
+  int sin; // okay; 'sin' has not been declared, even though it's a builtin.
 }