When tree-transforming an expression sequence, always flag expanded

variadic argument pack expansions as having changed, rather than doing
it for each changed expansion, which leaves out zero-argument packs
with catastrophic consequences.

Fixes PR10260.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134483 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 0 deletions

diff --git a/test/CodeGenCXX/variadic-templates.cpp b/test/CodeGenCXX/variadic-templates.cpp
index 4f3cf1fe9d..90c8370675 100644
--- a/test/CodeGenCXX/variadic-templates.cpp
+++ b/test/CodeGenCXX/variadic-templates.cpp
@@ -9,4 +9,15 @@ int get_num_types(Types...) {
 // CHECK: ret i32 3
 template int get_num_types(int, float, double);
 
+// PR10260 - argument packs that expand to nothing
+namespace test1 {
+  template <class... T> void foo() {
+    int values[sizeof...(T)+1] = { T::value... };
+    // CHECK: define linkonce_odr void @_ZN5test13fooIJEEEvv()
+    // CHECK: alloca [1 x i32], align 4
+  }
 
+  void test() {
+    foo<>();
+  }
+}