c error recovery. treat an invalid redeclaration

of a c-function for what it is. Otherwise, this func
is treated as an overloadable c-function resulting in
a crash much later. // rdar://11743706

llvm-svn: 163224

clang/lib/Sema/SemaDecl.cpp

@@ -5565,6 +5565,9 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
       D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
                                                   isExplicitSpecialization));
     }
+    // Make graceful recovery from an invalid redeclaration.
+    else if (!Previous.empty())
+           D.setRedeclaration(true);
     assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||
             Previous.getResultKind() != LookupResult::FoundOverloaded) &&
            "previous declaration set still overloaded");

clang/test/Sema/invalid-decl.c

@@ -29,3 +29,12 @@ typedef struct {
 void f(StructType *buf) {
   buf->fun = 0;
 }
+
+// rdar://11743706
+static void bar(hid_t, char); // expected-error {{expected identifier}}
+
+static void bar(hid_t p, char); // expected-error {{unknown type name 'hid_t'}}
+
+void foo() {
+  (void)bar;
+}