From dc9bc5aeb8cc34f9fda7d23e0ddb7c3d50f15bea Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Tue, 2 Nov 2010 16:54:00 +0000
Subject: [PATCH] Fix a crash mangling decayed val argument-typed function. //
 rdar: //8620510 and PR7666

llvm-svn: 118019
---
 clang/lib/CodeGen/Mangle.cpp     | 4 +++-
 clang/test/CodeGenCXX/mangle.cpp | 6 ++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/clang/lib/CodeGen/Mangle.cpp b/clang/lib/CodeGen/Mangle.cpp
index e47d9cb43a62..37ecf285983f 100644
--- a/clang/lib/CodeGen/Mangle.cpp
+++ b/clang/lib/CodeGen/Mangle.cpp
@@ -1324,7 +1324,9 @@ void CXXNameMangler::mangleType(const ConstantArrayType *T) {
 }
 void CXXNameMangler::mangleType(const VariableArrayType *T) {
   Out << 'A';
-  mangleExpression(T->getSizeExpr());
+  // decayed vla types (size 0) will just be skipped.
+  if (T->getSizeExpr())
+    mangleExpression(T->getSizeExpr());
   Out << '_';
   mangleType(T->getElementType());
 }
diff --git a/clang/test/CodeGenCXX/mangle.cpp b/clang/test/CodeGenCXX/mangle.cpp
index 55357c7d63a4..e78ad3996eeb 100644
--- a/clang/test/CodeGenCXX/mangle.cpp
+++ b/clang/test/CodeGenCXX/mangle.cpp
@@ -624,3 +624,9 @@ namespace test20 {
   template <class T> void test1(decltype(f<>(T()))) {}
   template void test1<int>(decltype(f<>(int())));
 }
+
+// rdar:// 8620510
+namespace test21 {
+  // CHECK: define void @_ZN6test2112vla_arg_funcEiPA_i(
+  void vla_arg_func(int X, int a[X][X]) {}
+}