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

5 files changed, 12 insertions, 2 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index e7dbe791c9..e17494aac8 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -2396,7 +2396,10 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
 
   case CK_Dependent:
     llvm_unreachable("dependent cast kind in IR gen!");
- 
+
+  case CK_BuiltinFnToFnPtr:
+    llvm_unreachable("builtin functions are handled elsewhere");
+
   // These two casts are currently treated as no-ops, although they could
   // potentially be real operations depending on the target's ABI.
   case CK_NonAtomicToAtomic:
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index b5628b5e96..a2101fb442 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -647,6 +647,7 @@ void AggExprEmitter::VisitCastExpr(CastExpr *E) {
   case CK_ARCReclaimReturnedObject:
   case CK_ARCExtendBlockObject:
   case CK_CopyAndAutoreleaseBlockObject:
+  case CK_BuiltinFnToFnPtr:
     llvm_unreachable("cast kind invalid for aggregate types");
   }
 }
diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 0233745afa..de3505c105 100644
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -427,6 +427,7 @@ ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
   case CK_ARCReclaimReturnedObject:
   case CK_ARCExtendBlockObject:
   case CK_CopyAndAutoreleaseBlockObject:
+  case CK_BuiltinFnToFnPtr:
     llvm_unreachable("invalid cast kind for complex value");
 
   case CK_FloatingRealToComplex:
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index a17a43639a..8a2a586fa4 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -691,6 +691,9 @@ public:
 
     case CK_Dependent: llvm_unreachable("saw dependent cast!");
 
+    case CK_BuiltinFnToFnPtr:
+      llvm_unreachable("builtin functions are handled elsewhere");
+
     case CK_ReinterpretMemberPointer:
     case CK_DerivedToBaseMemberPointer:
     case CK_BaseToDerivedMemberPointer:
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 58692f5cb3..d5ed233a97 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -1036,7 +1036,9 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
   // are in the same order as in the CastKind enum.
   switch (Kind) {
   case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
-      
+  case CK_BuiltinFnToFnPtr:
+    llvm_unreachable("builtin functions are handled elsewhere");
+
   case CK_LValueBitCast: 
   case CK_ObjCObjectLValueCast: {
     Value *V = EmitLValue(E).getAddress();