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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@295006 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 71c8fb8b7ae358e73e7e529a214a84123529949d..ebe0841b3c2353cfc6249a8f4a86bbfafbc795e1 100644 (file)
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/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;

diff --git a/test/CodeGenCXX/new-array-init.cpp b/test/CodeGenCXX/new-array-init.cpp
index 0429ae770bc814083385d7b1cf6595b5e7ce157f..ccc218e2b2dcf929175b74263aa4d4ab0adc165f 100644 (file)
--- a/test/CodeGenCXX/new-array-init.cpp
+++ b/test/CodeGenCXX/new-array-init.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++11 -triple i386-unknown-unknown %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -std=c++11 -triple i386-unknown-unknown %s -emit-llvm -fsanitize=signed-integer-overflow -o - | FileCheck --check-prefix=SIO %s
 
 // CHECK: @[[ABC4:.*]] = {{.*}} constant [4 x i8] c"abc\00"
 // CHECK: @[[ABC15:.*]] = {{.*}} constant [15 x i8] c"abc\00\00\00\00
@@ -116,3 +117,9 @@ void aggr_sufficient(int n) {
   struct Aggr { int a, b; };
   new Aggr[n] { 1, 2, 3 };
 }
+
+// SIO-LABEL: define void @_Z14constexpr_testv
+void constexpr_test() {
+  // SIO: call i8* @_Zna{{.}}(i32 4)
+  new int[0+1]{0};
+}