When the new expr's array size is an ICE, emit it as a constant expression.

This bypasses integer sanitization checks which are redundant on the expression since it's been checked by Sema. Fixes a clang codegen assertion on "void test() { new int[0+1]{0}; }" when building with -fsanitize=signed-integer-overflow.

llvm-svn: 295006

1 files changed, 4 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 71c8fb8b7ae..ebe0841b3c2 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -659,7 +659,10 @@ static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
   // Emit the array size expression.
   // We multiply the size of all dimensions for NumElements.
   // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6.
-  numElements = CGF.EmitScalarExpr(e->getArraySize());
+  numElements = CGF.CGM.EmitConstantExpr(e->getArraySize(),
+                                         CGF.getContext().getSizeType(), &CGF);
+  if (!numElements)
+    numElements = CGF.EmitScalarExpr(e->getArraySize());
   assert(isa<llvm::IntegerType>(numElements->getType()));
 
   // The number of elements can be have an arbitrary integer type;