Modules: Search for a visible definition of the decl context when computing visibility of a default template parameter

The code is/was already correct for the case where a parameter is a
parameter of its enclosing lexical DeclContext (functions and classes).
But for other templates (alias and variable templates) they don't create
their own scope to be members of - in those cases, they parameter should
be considered visible if any definition of the lexical decl context is
visible.

[this should cleanup the failure on the libstdc++ modules buildbot]
[this doesn't actually fix the variable template case for a
secondary/compounding reason (its lexical decl context is incorrectly
considered to be the translation unit)]

Test covers all 4 kinds of templates with default args, including a
regression test for the still broken variable template case.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D60892

llvm-svn: 358795

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/test/Modules/Inputs/nested-template-default-arg-redecl/alias1.h b/clang/test/Modules/Inputs/nested-template-default-arg-redecl/alias1.h
new file mode 100644
index 00000000000..736abcbbda4
--- /dev/null
+++ b/clang/test/Modules/Inputs/nested-template-default-arg-redecl/alias1.h
@@ -0,0 +1 @@
+#include "alias.h"