From: Nathaniel Shead <nathanieloshead@gmail.com>
Date: Mon, 10 Nov 2025 12:41:25 +0000 (+1100)
Subject: c++/modules: Propagate purviewness to all parent namespaces
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2fbb6b2618e5220c049d889768b3aa3d48fda2ca;p=thirdparty%2Fgcc.git

c++/modules: Propagate purviewness to all parent namespaces

In PR c++/100134, tsubst_friend_function was adjusted to ensure that
instantiating a friend function in an unopened namespace still correctly
marked the namespace as purview.  This adjusts the fix to also apply
to nested namespaces.

gcc/cp/ChangeLog:

	* pt.cc (tsubst_friend_function): Mark all parent namespaces as
	purview if needed.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/tpl-friend-8_a.H: Add testcase.
	* g++.dg/modules/tpl-friend-8_b.C: Add testcase.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
---

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 02e795fab33..bbbf49363e8 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -11905,9 +11905,10 @@ tsubst_friend_function (tree decl, tree args)
 	 without necessarily having opened the enclosing namespace, so
 	 make sure the namespace is in the purview now too.  */
       if (modules_p ()
-	  && DECL_MODULE_PURVIEW_P (STRIP_TEMPLATE (new_friend))
-	  && TREE_CODE (DECL_CONTEXT (new_friend)) == NAMESPACE_DECL)
-	DECL_MODULE_PURVIEW_P (DECL_CONTEXT (new_friend)) = true;
+	  && DECL_MODULE_PURVIEW_P (STRIP_TEMPLATE (new_friend)))
+	for (tree ctx = DECL_CONTEXT (new_friend);
+	     TREE_CODE (ctx) == NAMESPACE_DECL; ctx = DECL_CONTEXT (ctx))
+	  DECL_MODULE_PURVIEW_P (ctx) = true;
     }
   else
     {
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H b/gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H
index bd2290460b5..7269d8eb794 100644
--- a/gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-8_a.H
@@ -7,3 +7,13 @@ namespace std {
     friend void f(A) { }
   };
 }
+
+namespace outer {
+  namespace inner {
+    inline namespace more_inner {
+      template<class T> struct B {
+	friend void g() {}
+      };
+    }
+  }
+}
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C b/gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C
index 76d7447c2eb..47569aa83c5 100644
--- a/gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-8_b.C
@@ -1,8 +1,13 @@
 // PR c++/100134
-// { dg-additional-options -fmodules-ts }
+// { dg-additional-options "-fmodules -Wno-global-module" }
 // { dg-module-cmi pr100134 }
+module;
+namespace outer::inner {
+  inline namespace more_inner {}
+}
 export module pr100134;
 
 import "tpl-friend-8_a.H";
 
 export std::A<int> a;
+export outer::inner::B<int> b;