When performing name lookup for a redeclaration, ignore module

visibility restrictions. This ensures that all declarations of the
same entity end up in the same redeclaration chain, even if some of
those declarations aren't visible. While this may seem unfortunate to
some---why can't two C modules have different functions named
'f'?---it's an acknowedgment that a module does not introduce a new
"namespace" of names.

As part of this, stop merging the 'module-private' bit from previous
declarations to later declarations, because we want each declaration
in a module to stand on its own because this can effect, for example,
submodule visibility.

Note that this notion of names that are invisible to normal name
lookup but are available for redeclaration lookups is how we should
implement friend declarations and extern declarations within local
function scopes. I'm not tackling that problem now.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146980 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 0 deletions

diff --git a/test/Modules/redecl-merge.m b/test/Modules/redecl-merge.m
index 6497268c38..7021d14f69 100644
--- a/test/Modules/redecl-merge.m
+++ b/test/Modules/redecl-merge.m
@@ -20,6 +20,18 @@ B *f1() {
 
 @class B;
 
+// Test redeclarations of entities in explicit submodules, to make
+// sure we're maintaining the declaration chains even when normal name
+// lookup can't see what we're looking for.
+void testExplicit() {
+  Explicit *e;
+  int *(*fp)(void) = &explicit_func;
+  int *ip = explicit_func();
+
+  // FIXME: Should complain about definition not having been imported.
+  struct explicit_struct es = { 0 };
+}
+
 __import_module__ redecl_merge_bottom;
 
 @implementation B