When doing arithmatic on vla pointer, make sure

to emit vla size to prevent an irgen crash.
// rdar://11485774


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158117 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 23 insertions, 0 deletions

diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index e0265545be..fa7b136831 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -1970,6 +1970,9 @@ static Value *emitPointerArithmetic(CodeGenFunction &CGF,
   QualType elementType = pointerType->getPointeeType();
   if (const VariableArrayType *vla
         = CGF.getContext().getAsVariableArrayType(elementType)) {
+    // arithmatic on VLA pointer - make sure to emit the VLA size.
+    CGF.EmitVariablyModifiedType(elementType);
+    
     // The element count here is the total number of non-VLA elements.
     llvm::Value *numElements = CGF.getVLASize(vla).first;
 
diff --git a/test/CodeGen/vla.c b/test/CodeGen/vla.c
index 9e62da52e0..d34f26b779 100644
--- a/test/CodeGen/vla.c
+++ b/test/CodeGen/vla.c
@@ -142,3 +142,23 @@ int test4(unsigned n, char (*p)[n][n+1][6]) {
   // CHECK-NEXT: ret i32 [[T7]]
   return p2 - p;
 }
+
+// rdar://11485774
+void test5(void)
+{
+  // CHECK: define void @test5(
+  int a[5], i = 0;
+  // CHECK: [[A:%.*]] = alloca [5 x i32], align 4
+  // CHECK-NEXT: [[I:%.*]] = alloca i32, align 4
+  // CHECK-NEXT: [[CL:%.*]] = alloca i32*, align 4
+  // CHECK-NEXT: store i32 0, i32* [[I]], align 4
+
+  (typeof(++i, (int (*)[i])a)){&a} += 0;
+  // CHECK-NEXT: [[Z:%.*]] = bitcast [5 x i32]* [[A]] to i32*
+  // CHECK-NEXT: store i32* [[Z]], i32** [[CL]]
+  // CHECK-NEXT: [[O:%.*]]  = load i32** [[CL]]
+  // CHECK-NEXT: [[T:%.*]] = load i32* [[I]], align 4
+  // CHECK-NEXT: [[VLAIX:%.*]] = mul nsw i32 0, [[T]]
+  // CHECK-NEXT: [[ADDPTR:%.*]] = getelementptr inbounds i32* [[O]], i32 [[VLAIX]]
+  // CHECK-NEXT: store i32* [[ADDPTR]], i32** [[CL]]
+}