Fix scoping of method declarations and issue

warning when same parameter name used multiple times.
// rdar://8877730


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125229 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 77 insertions, 11 deletions

diff --git a/include/clang/Basic/DiagnosticCommonKinds.td b/include/clang/Basic/DiagnosticCommonKinds.td
index 49504e6e22..85c64c5cef 100644
--- a/include/clang/Basic/DiagnosticCommonKinds.td
+++ b/include/clang/Basic/DiagnosticCommonKinds.td
@@ -44,6 +44,7 @@ def err_expected_colon_after_setter_name : Error<
 def ext_no_declarators : ExtWarn<"declaration does not declare anything">,
   InGroup<MissingDeclarations>;
 def err_param_redefinition : Error<"redefinition of parameter %0">;
+def warn_method_param_redefinition : Warning<"redefinition of method parameter %0">;
 def err_invalid_storage_class_in_func_decl : Error<
   "invalid storage class specifier in function declarator">;
 def err_expected_namespace_name : Error<"expected namespace name">;
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 8b24e925ed..4731ad8d27 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -4251,6 +4251,7 @@ public:
   };
 
   Decl *ActOnMethodDeclaration(
+    Scope *S,
     SourceLocation BeginLoc, // location of the + or -.
     SourceLocation EndLoc,   // location of the ; or {.
     tok::TokenKind MethodType,
diff --git a/lib/Parse/ParseObjc.cpp b/lib/Parse/ParseObjc.cpp
index af53d7d592..0aae43adb8 100644
--- a/lib/Parse/ParseObjc.cpp
+++ b/lib/Parse/ParseObjc.cpp
@@ -868,7 +868,7 @@ Decl *Parser::ParseObjCMethodDecl(SourceLocation mLoc,
 
     Selector Sel = PP.getSelectorTable().getNullarySelector(SelIdent);
     Decl *Result
-         = Actions.ActOnMethodDeclaration(mLoc, Tok.getLocation(),
+         = Actions.ActOnMethodDeclaration(getCurScope(), mLoc, Tok.getLocation(),
                                           mType, IDecl, DSRet, ReturnType, Sel,
                                           0, 
                                           CParamInfo.data(), CParamInfo.size(),
@@ -879,7 +879,9 @@ Decl *Parser::ParseObjCMethodDecl(SourceLocation mLoc,
 
   llvm::SmallVector<IdentifierInfo *, 12> KeyIdents;
   llvm::SmallVector<Sema::ObjCArgInfo, 12> ArgInfos;
-
+  ParseScope PrototypeScope(this,
+                            Scope::FunctionPrototypeScope|Scope::DeclScope);
+  
   while (1) {
     Sema::ObjCArgInfo ArgInfo;
 
@@ -976,18 +978,25 @@ Decl *Parser::ParseObjCMethodDecl(SourceLocation mLoc,
   // If attributes exist after the method, parse them.
   if (getLang().ObjC2)
     MaybeParseGNUAttributes(attrs);
-
-  if (KeyIdents.size() == 0)
+  
+  if (KeyIdents.size() == 0) {
+    // Leave prototype scope.
+    PrototypeScope.Exit();
     return 0;
+  }
+  
   Selector Sel = PP.getSelectorTable().getSelector(KeyIdents.size(),
                                                    &KeyIdents[0]);
   Decl *Result
-       = Actions.ActOnMethodDeclaration(mLoc, Tok.getLocation(),
+       = Actions.ActOnMethodDeclaration(getCurScope(), mLoc, Tok.getLocation(),
                                         mType, IDecl, DSRet, ReturnType, Sel,
                                         &ArgInfos[0], 
                                         CParamInfo.data(), CParamInfo.size(),
                                         attrs.getList(),
                                         MethodImplKind, isVariadic);
+  // Leave prototype scope.
+  PrototypeScope.Exit();
+  
   PD.complete(Result);
   return Result;
 }
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index a2f6b516be..a3d93ab85e 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -1664,6 +1664,7 @@ bool containsInvalidMethodImplAttribute(const AttrVec &A) {
 }
 
 Decl *Sema::ActOnMethodDeclaration(
+    Scope *S,
     SourceLocation MethodLoc, SourceLocation EndLoc,
     tok::TokenKind MethodType, Decl *ClassDecl,
     ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
@@ -1721,6 +1722,20 @@ Decl *Sema::ActOnMethodDeclaration(
       ArgType = adjustParameterType(ArgType);
     }
 
+    LookupResult R(*this, ArgInfo[i].Name, ArgInfo[i].NameLoc, 
+                   LookupOrdinaryName, ForRedeclaration);
+    LookupName(R, S);
+    if (R.isSingleResult()) {
+      NamedDecl *PrevDecl = R.getFoundDecl();
+      if (S->isDeclScope(PrevDecl)) {
+        // FIXME. This should be an error; but will break projects.
+        Diag(ArgInfo[i].NameLoc, diag::warn_method_param_redefinition) 
+          << ArgInfo[i].Name;
+        Diag(PrevDecl->getLocation(), 
+             diag::note_previous_declaration);
+      }
+    }
+
     ParmVarDecl* Param
       = ParmVarDecl::Create(Context, ObjCMethod, ArgInfo[i].NameLoc,
                             ArgInfo[i].Name, ArgType, DI,
@@ -1739,9 +1754,12 @@ Decl *Sema::ActOnMethodDeclaration(
     // Apply the attributes to the parameter.
     ProcessDeclAttributeList(TUScope, Param, ArgInfo[i].ArgAttrs);
 
+    S->AddDecl(Param);
+    IdResolver.AddDecl(Param);
+
     Params.push_back(Param);
   }
-
+  
   for (unsigned i = 0, e = CNumArgs; i != e; ++i) {
     ParmVarDecl *Param = cast<ParmVarDecl>(CParamInfo[i].Param);
     QualType ArgType = Param->getType();
@@ -1757,8 +1775,7 @@ Decl *Sema::ActOnMethodDeclaration(
       Param->setInvalidDecl();
     }
     Param->setDeclContext(ObjCMethod);
-    if (Param->getDeclName())
-      IdResolver.RemoveDecl(Param);
+    
     Params.push_back(Param);
   }
   
diff --git a/test/Parser/objc-forcollection-neg-2.m b/test/Parser/objc-forcollection-neg-2.m
index e02c51c1ba..6aa74c9c0b 100644
--- a/test/Parser/objc-forcollection-neg-2.m
+++ b/test/Parser/objc-forcollection-neg-2.m
@@ -1,11 +1,11 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
 
 typedef struct objc_class *Class;
+struct __objcFastEnumerationState; 
 typedef struct objc_object {
  Class isa;
 } *id;
     
-            
 @protocol P @end
 
 @interface MyList
diff --git a/test/Parser/objc-forcollection-neg.m b/test/Parser/objc-forcollection-neg.m
index 0ba093efa0..d896c35f3f 100644
--- a/test/Parser/objc-forcollection-neg.m
+++ b/test/Parser/objc-forcollection-neg.m
@@ -1,5 +1,6 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
 
+struct __objcFastEnumerationState; 
 typedef struct objc_class *Class;
 typedef struct objc_object {
  Class isa;
diff --git a/test/Parser/objc-foreach-syntax.m b/test/Parser/objc-foreach-syntax.m
index 943540ef1f..cc82725b17 100644
--- a/test/Parser/objc-foreach-syntax.m
+++ b/test/Parser/objc-foreach-syntax.m
@@ -1,7 +1,6 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
 
-
-
+struct __objcFastEnumerationState; 
 @implementation MyList // expected-warning {{cannot find interface declaration for 'MyList'}}
 - (unsigned int)countByEnumeratingWithState:  (struct __objcFastEnumerationState *)state objects:  (id *)items count:(unsigned int)stackcount
 {
diff --git a/test/SemaObjC/method-prototype-scope.m b/test/SemaObjC/method-prototype-scope.m
new file mode 100644
index 0000000000..2184172f35
--- /dev/null
+++ b/test/SemaObjC/method-prototype-scope.m
@@ -0,0 +1,38 @@
+// RUN: %clang_cc1  -fsyntax-only -verify %s
+
+// rdar://8877730
+
+int object;
+
+@class NSString, NSArray;
+
+@interface Test 
+- Func:(int)XXXX, id object;
+
+- doSomethingElseWith:(id)object;
+
+- (NSString *)doSomethingWith:(NSString *)object and:(NSArray *)object; // expected-warning {{redefinition of method parameter 'object'}} \
+					  // expected-note {{previous declaration is here}}
+@end
+
+@implementation Test
+
+- (NSString *)doSomethingWith:(NSString *)object and:(NSArray *)object // expected-warning {{redefinition of method parameter 'object'}} \
+					  // expected-note {{previous declaration is here}}
+{
+    return object; // expected-warning {{incompatible pointer types returning 'NSArray *' from a function with result type 'NSString *'}}
+}
+
+- Func:(int)XXXX, id object { return object; }
+
+- doSomethingElseWith:(id)object { return object; }
+
+@end
+
+struct P;
+
+@interface Test1
+- doSomethingWith:(struct S *)object and:(struct P *)obj; // expected-warning {{declaration of 'struct S' will not be visible outside of this function}}
+@end
+
+int obj;