Check for duplicate declaration of method of a class

in its extension.

llvm-svn: 65854

1 files changed, 31 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index f1f03844a24..fe26090a174 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -443,6 +443,35 @@ void Sema::MergeProtocolPropertiesIntoClass(Decl *CDecl,
   }
 }
 
+/// DiagnoseClassExtensionDupMethods - Check for duplicate declartation of
+/// a class method in its extension.
+///
+void Sema::DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT, 
+                                            ObjCInterfaceDecl *ID) {
+  if (!ID)
+    return;  // Possibly due to previous error
+
+  llvm::DenseMap<Selector, const ObjCMethodDecl*> MethodMap;
+  for (ObjCInterfaceDecl::method_iterator i = ID->meth_begin(),
+       e =  ID->meth_end(); i != e; ++i) {
+    ObjCMethodDecl *MD = *i;
+    MethodMap[MD->getSelector()] = MD;
+  }
+
+  if (MethodMap.empty())
+    return;
+  for (ObjCCategoryDecl::method_iterator i = CAT->meth_begin(),
+       e =  CAT->meth_end(); i != e; ++i) {
+    ObjCMethodDecl *Method = *i;
+    const ObjCMethodDecl *&PrevMethod = MethodMap[Method->getSelector()];
+    if (PrevMethod && !MatchTwoMethodDeclarations(Method, PrevMethod)) {
+      Diag(Method->getLocation(), diag::err_duplicate_method_decl)
+            << Method->getDeclName();
+      Diag(PrevMethod->getLocation(), diag::note_previous_declaration);
+    }
+  }
+}
+
 /// ActOnForwardProtocolDeclaration - 
 Action::DeclTy *
 Sema::ActOnForwardProtocolDeclaration(SourceLocation AtProtocolLoc,
@@ -1237,6 +1266,8 @@ void Sema::ActOnAtEnd(SourceLocation AtEndLoc, DeclTy *classDecl,
 
     // Merge protocol properties into category
     MergeProtocolPropertiesIntoClass(C, C);
+    if (C->getIdentifier() == 0)
+      DiagnoseClassExtensionDupMethods(C, C->getClassInterface());
   }
   if (ObjCContainerDecl *CDecl = dyn_cast<ObjCContainerDecl>(ClassDecl)) {
     // ProcessPropertyDecl is responsible for diagnosing conflicts with any