Fix a crash mangling decayed val argument-typed function.

// rdar: //8620510 and PR7666

llvm-svn: 118019

2 files changed, 9 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/Mangle.cpp b/clang/lib/CodeGen/Mangle.cpp
index e47d9cb43a6..37ecf285983 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 55357c7d63a..e78ad3996ee 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]) {}
+}