Fix crash when using archaic protocol, rdar://10238337

llvm-svn: 141215

clang/lib/AST/SelectorLocationsKind.cpp

@@ -54,8 +54,11 @@ SourceLocation getArgLoc<Expr>(Expr *Arg) {
 
 template <>
 SourceLocation getArgLoc<ParmVarDecl>(ParmVarDecl *Arg) {
+  SourceLocation Loc = Arg->getLocStart();
+  if (Loc.isInvalid())
+    return Loc;
   // -1 to point to left paren of the method parameter's type.
-  return Arg->getLocStart().getLocWithOffset(-1);
+  return Loc.getLocWithOffset(-1);
 }
 
 template <typename T>

clang/test/SemaObjC/protocol-archane.m

@@ -33,3 +33,10 @@ typedef struct objc_class *Class;
 
 Class <SomeProtocol> UnfortunateGCCExtension;
 
+// rdar://10238337
+@protocol Broken @end
+@interface Crash @end
+@implementation Crash
+- (void)crashWith:(<Broken>)a { // expected-warning {{protocol qualifiers without 'id' is archaic}}
+}
+@end