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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198531 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 9c74ae4ce2..220b1c4a35 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -31,6 +31,7 @@
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/LLVMContext.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -1844,6 +1845,12 @@ lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
 
 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
                                             SelectionDAG &DAG) const {
+  if (!isa<ConstantSDNode>(Op.getOperand(0))) {
+    DAG.getContext()->emitError("argument to '__builtin_return_address' must "
+                                "be a constant integer");
+    return SDValue();
+  }
+
   // check the depth
   assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
          "Return address can be determined only for current frame.");