[PATCH] c++: Clear uninstantiated friend flag when instantiating [PR104234]

[Nathaniel Shead]

Bootstrapped and regtested on x86_64-pc-linux-gnu. I don't have write
access.

-- >8 --

Otherwise attempting to get the originating module declaration ICEs
because the DECL_CHAIN of an instantiated friend template is no longer
its context.

        PR c++/104234
        PR c++/112580

gcc/cp/ChangeLog:

        * pt.cc (tsubst_template_decl):

gcc/testsuite/ChangeLog:

        * g++.dg/modules/pr104234.C: New test.

Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
---
 gcc/cp/pt.cc                            |  2 ++
 gcc/testsuite/g++.dg/modules/pr104234.C | 16 ++++++++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/modules/pr104234.C

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index ed681afb5d4..5e10a523e1a 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -14789,6 +14789,8 @@ tsubst_template_decl (tree t, tree args, tsubst_flags_t 
complain,
   if (PRIMARY_TEMPLATE_P (t))
     DECL_PRIMARY_TEMPLATE (r) = r;
 
+  DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P (r) = false;
+
   if (!lambda_fntype && !class_p)
     {
       /* Record this non-type partial instantiation.  */
diff --git a/gcc/testsuite/g++.dg/modules/pr104234.C 
b/gcc/testsuite/g++.dg/modules/pr104234.C
new file mode 100644
index 00000000000..d81f0d435bc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/pr104234.C
@@ -0,0 +1,16 @@
+// PR c++/104234
+// { dg-additional-options "-fmodules-ts" }
+
+template <typename> struct _Node_handle_common {
+  template <typename> friend class _Rb_tree;
+};
+struct _Hashtable {
+  using node_type = _Node_handle_common<int>;
+  node_type __trans_tmp_1;
+};
+template <typename> class _Rb_tree {
+  struct _Rb_tree_impl {
+    _Rb_tree_impl();
+  } _M_impl;
+};
+_Rb_tree<int> _M_tmap_;
-- 
2.42.0