[PATCH] c++/modules: befriending template from current class scope

[Patrick Palka]

Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look
OK for trunk?

-- >8 --

Here the TEMPLATE_DECL representing the template friend declaration for
B has class scope since B has class scope, but get_merge_kind assumes
all DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P TEMPLATE_DECL have namespace
scope and wrongly returns MK_named instead of MK_local_friend.

gcc/cp/ChangeLog:

        * module.cc (trees_out::get_merge_kind) <case depset::EK_DECL>:
        Accomodate class-scope DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P
        TEMPLATE_DECL.  Merge IDENTIFIER_ANON_P branches.

gcc/testsuite/ChangeLog:

        * g++.dg/modules/friend-7.h: New test.
        * g++.dg/modules/friend-7_a.H: New test.
        * g++.dg/modules/friend-7_b.C: New test.
---
 gcc/cp/module.cc                          | 19 +++++++++----------
 gcc/testsuite/g++.dg/modules/friend-7.h   |  5 +++++
 gcc/testsuite/g++.dg/modules/friend-7_a.H |  3 +++
 gcc/testsuite/g++.dg/modules/friend-7_b.C |  5 +++++
 4 files changed, 22 insertions(+), 10 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/modules/friend-7.h
 create mode 100644 gcc/testsuite/g++.dg/modules/friend-7_a.H
 create mode 100644 gcc/testsuite/g++.dg/modules/friend-7_b.C

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 106af7bdb3e..fa91c6ff9cb 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -10491,21 +10491,20 @@ trees_out::get_merge_kind (tree decl, depset *dep)
                    break;
                  }
 
-           if (RECORD_OR_UNION_TYPE_P (ctx))
+           if (TREE_CODE (decl) == TEMPLATE_DECL
+               && DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P (decl))
              {
-               if (IDENTIFIER_ANON_P (DECL_NAME (decl)))
-                 mk = MK_field;
+               mk = MK_local_friend;
                break;
              }
 
-           if (TREE_CODE (decl) == TEMPLATE_DECL
-               && DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P (decl))
-             mk = MK_local_friend;
-           else if (IDENTIFIER_ANON_P (DECL_NAME (decl)))
+           if (IDENTIFIER_ANON_P (DECL_NAME (decl)))
              {
-               if (DECL_IMPLICIT_TYPEDEF_P (decl)
-                   && UNSCOPED_ENUM_P (TREE_TYPE (decl))
-                   && TYPE_VALUES (TREE_TYPE (decl)))
+               if (RECORD_OR_UNION_TYPE_P (ctx))
+                 mk = MK_field;
+               else if (DECL_IMPLICIT_TYPEDEF_P (decl)
+                        && UNSCOPED_ENUM_P (TREE_TYPE (decl))
+                        && TYPE_VALUES (TREE_TYPE (decl)))
                  /* Keyed by first enum value, and underlying type.  */
                  mk = MK_enum;
                else
diff --git a/gcc/testsuite/g++.dg/modules/friend-7.h 
b/gcc/testsuite/g++.dg/modules/friend-7.h
new file mode 100644
index 00000000000..c0f00394f3b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/friend-7.h
@@ -0,0 +1,5 @@
+template<class T>
+struct A {
+  template<class U> struct B { };
+  template<class U> friend struct B;
+};
diff --git a/gcc/testsuite/g++.dg/modules/friend-7_a.H 
b/gcc/testsuite/g++.dg/modules/friend-7_a.H
new file mode 100644
index 00000000000..e750e4c7d8d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/friend-7_a.H
@@ -0,0 +1,3 @@
+// { dg-additional-options "-fmodule-header" }
+// { dg-module-cmi {} }
+#include "friend-7.h"
diff --git a/gcc/testsuite/g++.dg/modules/friend-7_b.C 
b/gcc/testsuite/g++.dg/modules/friend-7_b.C
new file mode 100644
index 00000000000..d90b685d89d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/friend-7_b.C
@@ -0,0 +1,5 @@
+// { dg-additional-options "-fmodules-ts" }
+#include "friend-7.h"
+import "friend-7_a.H";
+
+A<int> a;
-- 
2.44.0.rc1.15.g4fc51f00ef