fix PR4010: add support for the warn_unused_result for function pointers

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91803 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 11 insertions, 8 deletions

diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 034b91ed0f..466ddc663f 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -398,14 +398,18 @@ void CallExpr::DoDestroy(ASTContext& C) {
   C.Deallocate(this);
 }
 
-FunctionDecl *CallExpr::getDirectCallee() {
+Decl *CallExpr::getCalleeDecl() {
   Expr *CEE = getCallee()->IgnoreParenCasts();
   if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CEE))
-    return dyn_cast<FunctionDecl>(DRE->getDecl());
+    return DRE->getDecl();
 
   return 0;
 }
 
+FunctionDecl *CallExpr::getDirectCallee() {
+    return dyn_cast_or_null<FunctionDecl>(getCalleeDecl());
+}
+
 /// setNumArgs - This changes the number of arguments present in this call.
 /// Any orphaned expressions are deleted by this, and any new operands are set
 /// to null.
@@ -858,7 +862,7 @@ bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1,
   case CXXMemberCallExprClass: {
     // If this is a direct call, get the callee.
     const CallExpr *CE = cast<CallExpr>(this);
-    if (const FunctionDecl *FD = CE->getDirectCallee()) {
+    if (const Decl *FD = CE->getCalleeDecl()) {
       // If the callee has attribute pure, const, or warn_unused_result, warn
       // about it. void foo() { strlen("bar"); } should warn.
       //
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 84ee207338..718db0437f 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -47,7 +47,7 @@ static const FunctionType *getFunctionType(const Decl *d,
 // FIXME: We should provide an abstraction around a method or function
 // to provide the following bits of information.
 
-/// isFunctionOrMethod - Return true if the given decl has function
+/// isFunction - Return true if the given decl has function
 /// type (function or function-typed variable).
 static bool isFunction(const Decl *d) {
   return getFunctionType(d, false) != NULL;
@@ -731,14 +731,13 @@ static void HandleWarnUnusedResult(Decl *D, const AttributeList &Attr, Sema &S)
   }
 
   // TODO: could also be applied to methods?
-  FunctionDecl *Fn = dyn_cast<FunctionDecl>(D);
-  if (!Fn) {
+  if (!isFunctionOrMethod(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << 0 /*function*/;
     return;
   }
 
-  Fn->addAttr(::new (S.Context) WarnUnusedResultAttr());
+  D->addAttr(::new (S.Context) WarnUnusedResultAttr());
 }
 
 static void HandleWeakAttr(Decl *D, const AttributeList &Attr, Sema &S) {
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index c2a3a3a8ca..6a68db75ea 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -96,7 +96,7 @@ void Sema::DiagnoseUnusedExprResult(const Stmt *S) {
   if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
     // If the callee has attribute pure, const, or warn_unused_result, warn with
     // a more specific message to make it clear what is happening.
-    if (const FunctionDecl *FD = CE->getDirectCallee()) {
+    if (const Decl *FD = CE->getCalleeDecl()) {
       if (FD->getAttr<WarnUnusedResultAttr>()) {
         Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result";
         return;