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, 9 insertions, 2 deletions

diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index cad8341afa..2ede77ec03 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -1310,12 +1310,16 @@ void CastExpr::CheckCastConsistency() const {
     assert(getType()->isBlockPointerType());
     assert(getSubExpr()->getType()->isBlockPointerType());
     goto CheckNoBasePath;
-      
+
+  case CK_FunctionToPointerDecay:
+    assert(getType()->isPointerType());
+    assert(getSubExpr()->getType()->isFunctionType());
+    goto CheckNoBasePath;
+
   // These should not have an inheritance path.
   case CK_Dynamic:
   case CK_ToUnion:
   case CK_ArrayToPointerDecay:
-  case CK_FunctionToPointerDecay:
   case CK_NullToMemberPointer:
   case CK_NullToPointer:
   case CK_ConstructorConversion:
@@ -1356,6 +1360,7 @@ void CastExpr::CheckCastConsistency() const {
   case CK_IntegralComplexToBoolean:
   case CK_LValueBitCast:            // -> bool&
   case CK_UserDefinedConversion:    // operator bool()
+  case CK_BuiltinFnToFnPtr:
   CheckNoBasePath:
     assert(path_empty() && "Cast kind should not have a base path!");
     break;
@@ -1468,6 +1473,8 @@ const char *CastExpr::getCastKindName() const {
     return "NonAtomicToAtomic";
   case CK_CopyAndAutoreleaseBlockObject:
     return "CopyAndAutoreleaseBlockObject";
+  case CK_BuiltinFnToFnPtr:
+    return "BuiltinFnToFnPtr";
   }
 
   llvm_unreachable("Unhandled cast kind!");