[pushed] c++: base template friend [PR52625]

[Jason Merrill via Gcc-patches]

Here we were mistakenly treating the injected-class-name as a partial
specialization.

Tested x86_64-pc-linux-gnu, applying to trunk.

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 a08d08d2834..dee802121e5 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 00000000000..54965486f79
--- /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;
+};

base-commit: a528594cf9a74e5a0fbac13ef673064ed73e1b89
-- 
2.27.0