Add Support for 'warn_unused_result" attribute on

objective-c methods. (radar 7418262).

llvm-svn: 99903

3 files changed, 26 insertions, 7 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 6a71e925d9b..b4e5a5d9602 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -914,8 +914,15 @@ bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
   case CXXConstructExprClass:
     return false;
 
-  case ObjCMessageExprClass:
+  case ObjCMessageExprClass: {
+    const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);
+    const ObjCMethodDecl *MD = ME->getMethodDecl();
+    if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
+      Loc = getExprLoc();
+      return true;
+    }
     return false;
+  }
 
   case ObjCImplicitSetterGetterRefExprClass: {   // Dot syntax for message send.
 #if 0
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index b3041129dba..d12dec4561c 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -837,18 +837,24 @@ static void HandleWarnUnusedResult(Decl *D, const AttributeList &Attr, Sema &S)
     return;
   }
 
-  if (!isFunction(D)) {
+  if (!isFunction(D) && !isa<ObjCMethodDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << 0 /*function*/;
     return;
   }
 
-  if (getFunctionType(D)->getResultType()->isVoidType()) {
-    S.Diag(Attr.getLoc(), diag::warn_attribute_void_function)
-      << Attr.getName();
+  if (isFunction(D) && getFunctionType(D)->getResultType()->isVoidType()) {
+    S.Diag(Attr.getLoc(), diag::warn_attribute_void_function_method)
+      << Attr.getName() << 0;
     return;
   }
-
+  if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
+    if (MD->getResultType()->isVoidType()) {
+      S.Diag(Attr.getLoc(), diag::warn_attribute_void_function_method)
+      << Attr.getName() << 1;
+      return;
+    }
+  
   D->addAttr(::new (S.Context) WarnUnusedResultAttr());
 }
 
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 733022aac35..1e37bb00c47 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -119,7 +119,13 @@ void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
       }
     }        
   }
-
+  else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
+    const ObjCMethodDecl *MD = ME->getMethodDecl();
+    if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
+      Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result";
+      return;
+    }
+  }
   Diag(Loc, DiagID) << R1 << R2;
 }