Emit an error message if the value passed to __builtin_returnaddress isn't a constant

__builtin_returnaddress requires that the value passed into is be a constant.
However, at -O0 even a constant expression may not be converted to a constant.
Emit an error message intead of crashing.

llvm-svn: 198531

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 882b5280fa1..b4bd0194ee4 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -26,6 +26,7 @@
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
 #include "llvm/IR/CallingConv.h"
+#include "llvm/IR/LLVMContext.h"
 
 using namespace llvm;
 
@@ -2131,6 +2132,12 @@ SDValue AArch64TargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) co
   MachineFrameInfo *MFI = MF.getFrameInfo();
   MFI->setReturnAddressIsTaken(true);
 
+  if (!isa<ConstantSDNode>(Op.getOperand(0))) {
+    DAG.getContext()->emitError("argument to '__builtin_return_address' must "
+                                "be a constant integer");
+    return SDValue();
+  }
+
   EVT VT = Op.getValueType();
   SDLoc dl(Op);
   unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();