[gcc r14-9327] c++/modules: befriending template from current class scope

[Patrick Palka via Gcc-cvs]

https://gcc.gnu.org/g:b0d11bb02a4a4c7d61e9b53411ccdc54610b1429

commit r14-9327-gb0d11bb02a4a4c7d61e9b53411ccdc54610b1429
Author: Patrick Palka <ppa...@redhat.com>
Date:   Tue Mar 5 20:36:36 2024 -0500

    c++/modules: befriending template from current class scope
    
    Here the TEMPLATE_DECL representing the template friend declaration
    naming B has class scope since the template 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 for the 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.  Consolidate IDENTIFIER_ANON_P cases.
    
    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.
    
    Reviewed-by: Jason Merrill <ja...@redhat.com>

Diff:
---
 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 |  6 ++++++
 4 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 67f132d28d7..80b63a70a62 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -10498,21 +10498,20 @@ trees_out::get_merge_kind (tree decl, depset *dep)
                    }
                }
 
-           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..eb5e45a3f43
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/friend-7_b.C
@@ -0,0 +1,6 @@
+// { dg-additional-options "-fmodules-ts" }
+#include "friend-7.h"
+import "friend-7_a.H";
+
+A<int> a;
+A<int>::B<char> b;