PR32185: Revert r291512 and add a testcase for PR32185.

This reverts an attempt to check that types match when matching a
dependently-typed non-type template parameter. (This comes up when matching the
parameters of a template template parameter against the parameters of a
template template argument.)

The matching rules here are murky at best. Our behavior after this revert is
definitely wrong for certain C++17 features (for 'auto' template parameter
types within the parameter list of a template template argument in particular),
but our behavior before this revert is wrong for some pre-existing testcases,
so reverting to our prior behavior seems like our best option.

llvm-svn: 300262

1 files changed, 3 insertions, 4 deletions

diff --git a/clang/test/SemaTemplate/deduction.cpp b/clang/test/SemaTemplate/deduction.cpp
index 8ac65aacd5b..74eb5a6ee58 100644
--- a/clang/test/SemaTemplate/deduction.cpp
+++ b/clang/test/SemaTemplate/deduction.cpp
@@ -483,16 +483,15 @@ namespace check_extended_pack {
 }
 
 namespace dependent_template_template_param_non_type_param_type {
-  template<int N> struct A { // expected-note 2{{candidate}}
+  template<int N> struct A {
     template<typename V = int, V M = 12, V (*Y)[M], template<V (*v)[M]> class W>
-    A(W<Y>); // expected-note {{[with V = int, M = 12, Y = &dependent_template_template_param_non_type_param_type::n]}}
+    A(W<Y>);
   };
 
   int n[12];
   template<int (*)[12]> struct Q {};
   Q<&n> qn;
-  // FIXME: This should be accepted, but we somehow fail to deduce W.
-  A<0> a(qn); // expected-error {{no matching constructor for initialization}}
+  A<0> a(qn);
 }
 
 namespace dependent_list_deduction {