Change the representation of builtin functions in the AST

(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call.  Fixes PR13195.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162962 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 8 deletions

diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index 2bbc41326e..19636f4143 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -2413,17 +2413,16 @@ public:
 
     // Build a reference to the __builtin_shufflevector builtin
     FunctionDecl *Builtin = cast<FunctionDecl>(*Lookup.first);
-    ExprResult Callee
-      = SemaRef.Owned(new (SemaRef.Context) DeclRefExpr(Builtin, false,
-                                                        Builtin->getType(),
-                                                        VK_LValue, BuiltinLoc));
-    Callee = SemaRef.UsualUnaryConversions(Callee.take());
-    if (Callee.isInvalid())
-      return ExprError();
+    Expr *Callee = new (SemaRef.Context) DeclRefExpr(Builtin, false,
+                                                  SemaRef.Context.BuiltinFnTy,
+                                                  VK_RValue, BuiltinLoc);
+    QualType CalleePtrTy = SemaRef.Context.getPointerType(Builtin->getType());
+    Callee = SemaRef.ImpCastExprToType(Callee, CalleePtrTy,
+                                       CK_BuiltinFnToFnPtr).take();
 
     // Build the CallExpr
     ExprResult TheCall = SemaRef.Owned(
-      new (SemaRef.Context) CallExpr(SemaRef.Context, Callee.take(), SubExprs,
+      new (SemaRef.Context) CallExpr(SemaRef.Context, Callee, SubExprs,
                                      Builtin->getCallResultType(),
                             Expr::getValueKindForType(Builtin->getResultType()),
                                      RParenLoc));