From b40d45cb1930e9aa8a1f9a6a8728fd47ebeeaaac Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Wed, 7 Apr 2021 15:38:07 -0400
Subject: [PATCH] c++: base template friend [PR52625]
Here we were mistakenly treating the injected-class-name as a partial
specialization.
gcc/cp/ChangeLog:
PR c++/52625
* pt.c (maybe_process_partial_specialization): Check
DECL_SELF_REFERENCE_P.
gcc/testsuite/ChangeLog:
PR c++/52625
* g++.dg/template/friend70.C: New test.
---
gcc/cp/pt.c | 4 ++++
gcc/testsuite/g++.dg/template/friend70.C | 9 +++++++++
2 files changed, 13 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/template/friend70.C
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index a08d08d28340..dee802121e5d 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -984,6 +984,10 @@ maybe_process_partial_specialization (tree type)
if (CLASS_TYPE_P (type) && CLASSTYPE_LAMBDA_EXPR (type))
return type;
+ /* An injected-class-name is not a specialization. */
+ if (DECL_SELF_REFERENCE_P (TYPE_NAME (type)))
+ return type;
+
if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
{
error ("name of class shadows template template parameter %qD",
diff --git a/gcc/testsuite/g++.dg/template/friend70.C b/gcc/testsuite/g++.dg/template/friend70.C
new file mode 100644
index 000000000000..54965486f795
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/friend70.C
@@ -0,0 +1,9 @@
+// PR c++/52625
+
+template<class>
+class base {};
+
+class derived : public base<derived>
+{
+ template<class> friend class base;
+};
--
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