Issue warning if method body starts with a semicolon.

Fixes 
<rdar://problem/7308503> clang should disallow the trailing semicolon in method definitions

llvm-svn: 84645

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -201,6 +201,9 @@ def warn_expected_implementation : Warning<
   "@end must appear in an @implementation context">;
 def error_property_ivar_decl : Error<
   "property synthesize requires specification of an ivar">;
+def warn_semicolon_before_method_nody : Warning<
+  "semicolon at start of method definition is ignored">,
+  InGroup<DiagGroup<"semicolon-at-method-body">>;
 
 def err_expected_field_designator : Error<
   "expected a field designator, such as '.field = 4'">;

clang/lib/Parse/ParseObjc.cpp

@@ -1371,8 +1371,11 @@ Parser::DeclPtrTy Parser::ParseObjCMethodDefinition() {
                                         "parsing Objective-C method");
 
   // parse optional ';'
-  if (Tok.is(tok::semi))
+  if (Tok.is(tok::semi)) {
+    if (ObjCImpDecl)
+      Diag(Tok, diag::warn_semicolon_before_method_nody);
     ConsumeToken();
+  }
 
   // We should have an opening brace now.
   if (Tok.isNot(tok::l_brace)) {

clang/test/SemaObjC/objc-string-constant.m

@@ -29,7 +29,7 @@
 @end
 
 @implementation Subclass
-- (NSString *)token;
+- (NSString *)token;	// expected-warning {{semicolon at start of method definition is ignored}}
 {
   NSMutableString *result = nil;
 

clang/test/SemaObjC/try-catch.m

@@ -30,7 +30,7 @@ typedef struct _NSZone NSZone;
 @end
 
 @implementation XCRefactoringTransformation
-- (NSDictionary *)setUpInfoForTransformKey:(NSString *)transformKey outError:(NSError **)outError; {
+- (NSDictionary *)setUpInfoForTransformKey:(NSString *)transformKey outError:(NSError **)outError {
     @try {}
     // the exception name is optional (weird)
     @catch (NSException *) {}