objective-C: warn under a flag if missing argument

name results in unintended selector name. 
// rdar://12263549

llvm-svn: 163634

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -357,6 +357,12 @@ def err_nsnumber_nonliteral_unary : Error<
 def warn_cstyle_param : Warning<
   "use of C-style parameters in Objective-C method declarations"
   " is deprecated">, InGroup<DeprecatedDeclarations>;
+def warn_missing_argument_name : Warning<
+  "no parameter name in the middle of a selector"
+  " may result in incomplete selector name">,
+  InGroup<DiagGroup<"missing-argument-name-in-selector">>, DefaultIgnore;
+def note_missing_argument_name : Note<
+  "did you mean %0 as the selector name">;
 
 let CategoryName = "ARC Parse Issue" in {
 def err_arc_bridge_retain : Error<

clang/lib/Parse/ParseObjc.cpp

@@ -1031,7 +1031,7 @@ Decl *Parser::ParseObjCMethodDecl(SourceLocation mLoc,
                             Scope::FunctionPrototypeScope|Scope::DeclScope);
 
   AttributePool allParamAttrs(AttrFactory);
-  
+  bool warnSelectorName = false;
   while (1) {
     ParsedAttributes paramAttrs(AttrFactory);
     Sema::ObjCArgInfo ArgInfo;
@@ -1100,8 +1100,16 @@ Decl *Parser::ParseObjCMethodDecl(SourceLocation mLoc,
     
     // Check for another keyword selector.
     SelIdent = ParseObjCSelectorPiece(selLoc);
-    if (!SelIdent && Tok.isNot(tok::colon))
-      break;
+    if (!SelIdent) {
+      if (Tok.isNot(tok::colon))
+        break;
+      // parameter name was not followed with selector name; as in:
+      // - (void) Meth: (id) Name:(id)Arg2; Issue a warning as user
+      // might have meant: - (void) Meth: (id)Arg1 Name:(id)Arg2;
+      Diag(Tok, diag::warn_missing_argument_name); // missing argument name.
+      warnSelectorName = true;
+    }
+    
     // We have a selector or a colon, continue parsing.
   }
 
@@ -1142,6 +1150,9 @@ Decl *Parser::ParseObjCMethodDecl(SourceLocation mLoc,
   
   Selector Sel = PP.getSelectorTable().getSelector(KeyIdents.size(),
                                                    &KeyIdents[0]);
+  if (warnSelectorName)
+    Diag(mLoc, diag::note_missing_argument_name) << Sel.getAsString();
+  
   Decl *Result
        = Actions.ActOnMethodDeclaration(getCurScope(), mLoc, Tok.getLocation(),
                                         mType, DSRet, ReturnType, 

clang/test/SemaObjC/warn-missing-selector-arg-name.m

@@ -0,0 +1,22 @@
+// RUN: %clang_cc1  -fsyntax-only -verify -Wno-objc-root-class -Wmissing-argument-name-in-selector %s
+// RUN: %clang_cc1 -x objective-c++ -fsyntax-only -verify -Wno-objc-root-class -Wmissing-argument-name-in-selector %s
+// rdar://12263549
+
+@interface Super @end
+@interface INTF : Super
+-(void) Name1:(id)Arg1 Name2:(id)Arg2; // Name1:Name2:
+-(void) Name1:(id) Name2:(id)Arg2; // expected-warning {{no parameter name in the middle of a selector may result in incomplete selector name}} \
+                                   // expected-note {{did you mean Name1:: as the selector name}}
+-(void) Name1:(id)Arg1 Name2:(id)Arg2 Name3:(id)Arg3; // Name1:Name2:Name3:
+-(void) Name1:(id)Arg1 Name2:(id) Name3:(id)Arg3; // expected-warning {{no parameter name in the middle of a selector may result in incomplete selector name}} \
+                                                  // expected-note {{did you mean Name1:Name2:: as the selector name}}
+@end
+
+@implementation INTF
+-(void) Name1:(id)Arg1 Name2:(id)Arg2{}
+-(void) Name1:(id) Name2:(id)Arg2 {} // expected-warning {{no parameter name in the middle of a selector may result in incomplete selector name}} \
+  				     // expected-note {{did you mean Name1:: as the selector name}}
+-(void) Name1:(id)Arg1 Name2:(id)Arg2 Name3:(id)Arg3 {}
+-(void) Name1:(id)Arg1 Name2:(id) Name3:(id)Arg3 {} // expected-warning {{no parameter name in the middle of a selector may result in incomplete selector name}} \
+						    // expected-note {{did you mean Name1:Name2:: as the selector name}}
+@end