[PATCH] c++: modules ICE with typename friend declaration

[Patrick Palka via Gcc-patches]

A couple of xtreme-header-* modules tests began ICEing in C++23 mode
ever since r13-2650-g5d84a4418aa962 introduced into <ranges> the
dependently scoped friend declaration

  friend /* typename */ _OuterIter::value_type;

ultimately because the streaming code assumes a TYPE_P friend must
be a class type, but here it's a TYPENAME_TYPE, which doesn't have
a TEMPLATE_INFO or CLASSTYPE_BEFRIENDING_CLASSES.  This patch tries
to correct this in a minimal way.

Tested on x86_64-pc-linux-gnu, does this look OK for trunk?

gcc/cp/ChangeLog:

        * module.cc (friend_from_decl_list): Don't consider
        CLASSTYPE_TEMPLATE_INFO for a TYPENAME_TYPE friend.
        (trees_in::read_class_def): Don't add to
        CLASSTYPE_BEFRIENDING_CLASSES for a TYPENAME_TYPE friend.

gcc/testsuite/ChangeLog:

        * g++.dg/modules/typename-friend.C: New test.
---
 gcc/cp/module.cc                               | 5 +++--
 gcc/testsuite/g++.dg/modules/typename-friend.C | 9 +++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/modules/typename-friend.C

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index f27f4d091e5..1a1ff5be574 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -4734,7 +4734,8 @@ friend_from_decl_list (tree frnd)
       if (TYPE_P (frnd))
        {
          res = TYPE_NAME (frnd);
-         if (CLASSTYPE_TEMPLATE_INFO (frnd))
+         if (CLASS_TYPE_P (frnd)
+             && CLASSTYPE_TEMPLATE_INFO (frnd))
            tmpl = CLASSTYPE_TI_TEMPLATE (frnd);
        }
       else if (DECL_TEMPLATE_INFO (frnd))
@@ -12121,7 +12122,7 @@ trees_in::read_class_def (tree defn, tree 
maybe_template)
            {
              tree f = TREE_VALUE (friend_classes);
 
-             if (TYPE_P (f))
+             if (CLASS_TYPE_P (f))
                {
                  CLASSTYPE_BEFRIENDING_CLASSES (f)
                    = tree_cons (NULL_TREE, type,
diff --git a/gcc/testsuite/g++.dg/modules/typename-friend.C 
b/gcc/testsuite/g++.dg/modules/typename-friend.C
new file mode 100644
index 00000000000..d8faf7955c3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/typename-friend.C
@@ -0,0 +1,9 @@
+// { dg-additional-options "-fmodules-ts" }
+
+export module x;
+
+template<class T>
+struct A {
+  friend typename T::type;
+  friend void f(A) { }
+};
-- 
2.37.3.662.g36f8e7ed7d