[C++] Interpret unknown identifier in parameter clause as unknown type

instead of as parameter name without a type.

llvm-svn: 359979

clang/lib/Parse/ParseDecl.cpp

@@ -2649,6 +2649,9 @@ bool Parser::ParseImplicitInt(DeclSpec &DS, CXXScopeSpec *SS,
     case tok::semi:
       // This looks like a variable or function declaration. The type is
       // probably missing. We're done parsing decl-specifiers.
+      // But only if we are not in a function prototype scope.
+      if (getCurScope()->isFunctionPrototypeScope())
+        break;
       if (SS)
         AnnotateScopeToken(*SS, /*IsNewAnnotation*/false);
       return false;

clang/test/Parser/editor-placeholder-recovery.cpp

@@ -64,7 +64,7 @@ void avoidPlaceholderErrors(Struct &obj) {
     }
 }
 
-void Struct::method(<#Struct &x#>, noSupressionHere) { // expected-error {{unknown type name 'noSupressionHere'}} expected-error {{C++ requires a type specifier for all declarations}}
+void Struct::method(<#Struct &x#>, noSupressionHere) { // expected-error {{unknown type name 'noSupressionHere'}}
 #ifndef SUPPRESS
   // expected-error@-2 {{editor placeholder in source file}}
 #endif

clang/test/SemaCXX/unknown-type-name.cpp

@@ -72,9 +72,7 @@ void f(int, T::type x, char) { } // expected-error{{missing 'typename'}}
 
 int *p;
 
-// FIXME: We should assume that 'undeclared' is a type, not a parameter name
-//        here, and produce an 'unknown type name' diagnostic instead.
-int f1(undeclared, int); // expected-error{{requires a type specifier}}
+int f1(undeclared, int); // expected-error{{unknown type name 'undeclared'}}
 
 int f2(undeclared, 0); // expected-error{{undeclared identifier}}