https://gcc.gnu.org/g:b5f6a56940e70838a07e885de03a92e2bd64674a
commit r15-59-gb5f6a56940e70838a07e885de03a92e2bd64674a
Author: Nathaniel Shead <nathanielosh...@gmail.com>
Date: Mon Apr 29 17:00:13 2024 +1000
c++: Fix instantiation of imported temploid friends [PR114275]
This patch fixes a number of issues with the handling of temploid friend
declarations.
The primary issue is that instantiations of friend declarations should
attach the declaration to the same module as the befriending class, by
[module.unit] p7.1 and [temp.friend] p2; this could be a different
module from the current TU, and so needs special handling.
The other main issue here is that we can't assume that just because name
lookup didn't find a definition for a hidden class template, that it
doesn't exist at all: it could be a non-exported entity that we've
nevertheless streamed in from an imported module. We need to ensure
that when instantiating template friend classes that we return the same
TEMPLATE_DECL that we got from our imports, otherwise we will get later
issues with 'duplicate_decls' (rightfully) complaining that they're
different when trying to merge.
This doesn't appear necessary for function templates due to the existing
name lookup handling already finding these hidden declarations.
PR c++/105320
PR c++/114275
gcc/cp/ChangeLog:
* cp-tree.h (propagate_defining_module): Declare.
(lookup_imported_hidden_friend): Declare.
* decl.cc (duplicate_decls): Also check if hidden decls can be
redeclared in this module.
* module.cc (imported_temploid_friends): New.
(init_modules): Initialize it.
(trees_out::decl_value): Write it; don't consider imported
temploid friends as attached to a module.
(trees_in::decl_value): Read it.
(get_originating_module_decl): Follow the owning decl for an
imported temploid friend.
(propagate_defining_module): New.
* name-lookup.cc (get_mergeable_namespace_binding): New.
(lookup_imported_hidden_friend): New.
* pt.cc (tsubst_friend_function): Propagate defining module for
new friend functions.
(tsubst_friend_class): Lookup imported hidden friends. Check
for valid module attachment of existing names. Propagate
defining module for new classes.
gcc/testsuite/ChangeLog:
* g++.dg/modules/tpl-friend-10_a.C: New test.
* g++.dg/modules/tpl-friend-10_b.C: New test.
* g++.dg/modules/tpl-friend-10_c.C: New test.
* g++.dg/modules/tpl-friend-10_d.C: New test.
* g++.dg/modules/tpl-friend-11_a.C: New test.
* g++.dg/modules/tpl-friend-11_b.C: New test.
* g++.dg/modules/tpl-friend-12_a.C: New test.
* g++.dg/modules/tpl-friend-12_b.C: New test.
* g++.dg/modules/tpl-friend-12_c.C: New test.
* g++.dg/modules/tpl-friend-12_d.C: New test.
* g++.dg/modules/tpl-friend-12_e.C: New test.
* g++.dg/modules/tpl-friend-12_f.C: New test.
* g++.dg/modules/tpl-friend-13_a.C: New test.
* g++.dg/modules/tpl-friend-13_b.C: New test.
* g++.dg/modules/tpl-friend-13_c.C: New test.
* g++.dg/modules/tpl-friend-13_d.C: New test.
* g++.dg/modules/tpl-friend-13_e.C: New test.
* g++.dg/modules/tpl-friend-13_f.C: New test.
* g++.dg/modules/tpl-friend-13_g.C: New test.
* g++.dg/modules/tpl-friend-14_a.C: New test.
* g++.dg/modules/tpl-friend-14_b.C: New test.
* g++.dg/modules/tpl-friend-14_c.C: New test.
* g++.dg/modules/tpl-friend-14_d.C: New test.
* g++.dg/modules/tpl-friend-9.C: New test.
Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
Reviewed-by: Jason Merrill <ja...@redhat.com>
Diff:
---
gcc/cp/cp-tree.h | 2 +
gcc/cp/decl.cc | 37 ++++++++-------
gcc/cp/module.cc | 62 ++++++++++++++++++++++++++
gcc/cp/name-lookup.cc | 53 ++++++++++++++++++++++
gcc/cp/pt.cc | 29 +++++++++++-
gcc/testsuite/g++.dg/modules/tpl-friend-10_a.C | 15 +++++++
gcc/testsuite/g++.dg/modules/tpl-friend-10_b.C | 5 +++
gcc/testsuite/g++.dg/modules/tpl-friend-10_c.C | 7 +++
gcc/testsuite/g++.dg/modules/tpl-friend-10_d.C | 8 ++++
gcc/testsuite/g++.dg/modules/tpl-friend-11_a.C | 14 ++++++
gcc/testsuite/g++.dg/modules/tpl-friend-11_b.C | 5 +++
gcc/testsuite/g++.dg/modules/tpl-friend-12_a.C | 10 +++++
gcc/testsuite/g++.dg/modules/tpl-friend-12_b.C | 9 ++++
gcc/testsuite/g++.dg/modules/tpl-friend-12_c.C | 10 +++++
gcc/testsuite/g++.dg/modules/tpl-friend-12_d.C | 8 ++++
gcc/testsuite/g++.dg/modules/tpl-friend-12_e.C | 7 +++
gcc/testsuite/g++.dg/modules/tpl-friend-12_f.C | 8 ++++
gcc/testsuite/g++.dg/modules/tpl-friend-13_a.C | 13 ++++++
gcc/testsuite/g++.dg/modules/tpl-friend-13_b.C | 11 +++++
gcc/testsuite/g++.dg/modules/tpl-friend-13_c.C | 13 ++++++
gcc/testsuite/g++.dg/modules/tpl-friend-13_d.C | 7 +++
gcc/testsuite/g++.dg/modules/tpl-friend-13_e.C | 18 ++++++++
gcc/testsuite/g++.dg/modules/tpl-friend-13_f.C | 7 +++
gcc/testsuite/g++.dg/modules/tpl-friend-13_g.C | 11 +++++
gcc/testsuite/g++.dg/modules/tpl-friend-14_a.C | 8 ++++
gcc/testsuite/g++.dg/modules/tpl-friend-14_b.C | 8 ++++
gcc/testsuite/g++.dg/modules/tpl-friend-14_c.C | 7 +++
gcc/testsuite/g++.dg/modules/tpl-friend-14_d.C | 9 ++++
gcc/testsuite/g++.dg/modules/tpl-friend-9.C | 13 ++++++
29 files changed, 397 insertions(+), 17 deletions(-)
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 4ac8cf69869..1938ada0268 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7417,6 +7417,7 @@ extern unsigned get_importing_module (tree, bool = false)
ATTRIBUTE_PURE;
extern void set_instantiating_module (tree);
extern void set_defining_module (tree);
extern void maybe_key_decl (tree ctx, tree decl);
+extern void propagate_defining_module (tree decl, tree orig);
extern void mangle_module (int m, bool include_partition);
extern void mangle_module_fini ();
@@ -7650,6 +7651,7 @@ extern bool template_guide_p
(const_tree);
extern bool builtin_guide_p (const_tree);
extern void store_explicit_specifier (tree, tree);
extern tree lookup_explicit_specifier (tree);
+extern tree lookup_imported_hidden_friend (tree);
extern void walk_specializations (bool,
void (*)(bool, spec_entry *,
void *),
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 91268ff631d..d88e0698652 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -2276,30 +2276,35 @@ duplicate_decls (tree newdecl, tree olddecl, bool
hiding, bool was_hidden)
if (modules_p ()
&& TREE_CODE (CP_DECL_CONTEXT (olddecl)) == NAMESPACE_DECL
- && TREE_CODE (olddecl) != NAMESPACE_DECL
- && !hiding)
+ && TREE_CODE (olddecl) != NAMESPACE_DECL)
{
if (!module_may_redeclare (olddecl, newdecl))
return error_mark_node;
- tree not_tmpl = STRIP_TEMPLATE (olddecl);
- if (DECL_LANG_SPECIFIC (not_tmpl)
- && DECL_MODULE_ATTACH_P (not_tmpl)
- /* Typedefs are not entities and so are OK to be redeclared
- as exported: see [module.interface]/p6. */
- && TREE_CODE (olddecl) != TYPE_DECL)
+ if (!hiding)
{
- if (DECL_MODULE_EXPORT_P (STRIP_TEMPLATE (newdecl))
- && !DECL_MODULE_EXPORT_P (not_tmpl))
+ /* The old declaration should match the exportingness of the new
+ declaration. But hidden friend declarations just keep the
+ exportingness of the old declaration; see CWG2588. */
+ tree not_tmpl = STRIP_TEMPLATE (olddecl);
+ if (DECL_LANG_SPECIFIC (not_tmpl)
+ && DECL_MODULE_ATTACH_P (not_tmpl)
+ /* Typedefs are not entities and so are OK to be redeclared
+ as exported: see [module.interface]/p6. */
+ && TREE_CODE (olddecl) != TYPE_DECL)
{
- auto_diagnostic_group d;
- error ("conflicting exporting for declaration %qD", newdecl);
- inform (olddecl_loc,
- "previously declared here without exporting");
+ if (DECL_MODULE_EXPORT_P (newdecl)
+ && !DECL_MODULE_EXPORT_P (not_tmpl))
+ {
+ auto_diagnostic_group d;
+ error ("conflicting exporting for declaration %qD", newdecl);
+ inform (olddecl_loc,
+ "previously declared here without exporting");
+ }
}
+ else if (DECL_MODULE_EXPORT_P (newdecl))
+ DECL_MODULE_EXPORT_P (not_tmpl) = true;
}
- else if (DECL_MODULE_EXPORT_P (newdecl))
- DECL_MODULE_EXPORT_P (not_tmpl) = true;
}
/* We have committed to returning OLDDECL at this point. */
diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index c2f077d6fd8..5b8ff5bc483 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -2727,6 +2727,12 @@ vec<tree, va_heap, vl_embed> *post_load_decls;
typedef hash_map<tree, auto_vec<tree>> keyed_map_t;
static keyed_map_t *keyed_table;
+/* Instantiations of temploid friends imported from another module
+ need to be attached to the same module as the temploid. This maps
+ these decls to the temploid they are instantiated them, as there is
+ no other easy way to get this information. */
+static hash_map<tree, tree> *imported_temploid_friends;
+
/********************************************************************/
/* Tree streaming. The tree streaming is very specific to the tree
structures themselves. A tag indicates the kind of tree being
@@ -7820,6 +7826,12 @@ trees_out::decl_value (tree decl, depset *dep)
&& DECL_MODULE_ATTACH_P (not_tmpl))
is_attached = true;
+ /* But don't consider imported temploid friends as attached,
+ since importers will need to merge this decl even if it was
+ attached to a different module. */
+ if (imported_temploid_friends->get (decl))
+ is_attached = false;
+
bits.b (is_attached);
}
bits.b (dep && dep->has_defn ());
@@ -7997,6 +8009,15 @@ trees_out::decl_value (tree decl, depset *dep)
}
}
+ if (TREE_CODE (inner) == FUNCTION_DECL
+ || TREE_CODE (inner) == TYPE_DECL)
+ {
+ /* Write imported temploid friends so that importers can reconstruct
+ this information on stream-in. */
+ tree* slot = imported_temploid_friends->get (decl);
+ tree_node (slot ? *slot : NULL_TREE);
+ }
+
bool is_typedef = false;
if (!type && TREE_CODE (inner) == TYPE_DECL)
{
@@ -8303,6 +8324,11 @@ trees_in::decl_value ()
}
}
+ if (TREE_CODE (inner) == FUNCTION_DECL
+ || TREE_CODE (inner) == TYPE_DECL)
+ if (tree owner = tree_node ())
+ imported_temploid_friends->put (decl, owner);
+
/* Regular typedefs will have a NULL TREE_TYPE at this point. */
unsigned tdef_flags = 0;
bool is_typedef = false;
@@ -18941,6 +18967,12 @@ get_originating_module_decl (tree decl)
&& DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P (decl))
decl = TYPE_NAME (DECL_CHAIN (decl));
+ /* An imported temploid friend is attached to the same module the
+ befriending class was. */
+ if (imported_temploid_friends)
+ if (tree *slot = imported_temploid_friends->get (decl))
+ decl = *slot;
+
int use;
if (tree ti = node_template_info (decl, use))
{
@@ -19249,6 +19281,34 @@ maybe_key_decl (tree ctx, tree decl)
vec.safe_push (decl);
}
+/* DECL is an instantiated friend that should be attached to the same
+ module that ORIG is. */
+
+void
+propagate_defining_module (tree decl, tree orig)
+{
+ if (!modules_p ())
+ return;
+
+ tree not_tmpl = STRIP_TEMPLATE (orig);
+ if (DECL_LANG_SPECIFIC (not_tmpl) && DECL_MODULE_ATTACH_P (not_tmpl))
+ {
+ tree inner = STRIP_TEMPLATE (decl);
+ retrofit_lang_decl (inner);
+ DECL_MODULE_ATTACH_P (inner) = true;
+ }
+
+ if (DECL_LANG_SPECIFIC (not_tmpl) && DECL_MODULE_IMPORT_P (not_tmpl))
+ {
+ bool exists = imported_temploid_friends->put (decl, orig);
+
+ /* We should only be called if lookup for an existing decl
+ failed, in which case there shouldn't already be an entry
+ in the map. */
+ gcc_assert (!exists);
+ }
+}
+
/* Create the flat name string. It is simplest to have it handy. */
void
@@ -20462,6 +20522,8 @@ init_modules (cpp_reader *reader)
pending_table = new pending_map_t (EXPERIMENT (1, 400));
entity_map = new entity_map_t (EXPERIMENT (1, 400));
vec_safe_reserve (entity_ary, EXPERIMENT (1, 400));
+ imported_temploid_friends
+ = new hash_map<tree,tree> (EXPERIMENT (1, 400));
}
#if CHECKING_P
diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 7af7f00e34c..4dffc0e9acc 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -4131,6 +4131,22 @@ mergeable_namespace_slots (tree ns, tree name, bool
is_attached, tree *vec)
return vslot;
}
+/* Retrieve the bindings for an existing mergeable entity in namespace
+ NS slot NAME. Returns NULL if no such bindings exists. */
+
+static tree
+get_mergeable_namespace_binding (tree ns, tree name, bool is_attached)
+{
+ tree *mslot = find_namespace_slot (ns, name, false);
+ if (!mslot || !*mslot || TREE_CODE (*mslot) != BINDING_VECTOR)
+ return NULL_TREE;
+
+ tree *vslot = get_fixed_binding_slot
+ (mslot, name, is_attached ? BINDING_SLOT_PARTITION : BINDING_SLOT_GLOBAL,
+ false);
+ return vslot ? *vslot : NULL_TREE;
+}
+
/* DECL is a new mergeable namespace-scope decl. Add it to the
mergeable entities on GSLOT. */
@@ -4453,6 +4469,43 @@ push_local_binding (tree id, tree decl, bool is_using)
add_decl_to_level (b, decl);
}
+/* Lookup the FRIEND_TMPL within all merged module imports. Used to dedup
+ instantiations of temploid hidden friends from imported modules. */
+
+tree
+lookup_imported_hidden_friend (tree friend_tmpl)
+{
+ /* For a class-scope friend class it should have been found by regular
+ name lookup. Otherwise we're looking in the current namespace. */
+ gcc_checking_assert (CP_DECL_CONTEXT (friend_tmpl) == current_namespace);
+
+ tree inner = DECL_TEMPLATE_RESULT (friend_tmpl);
+ if (!DECL_LANG_SPECIFIC (inner)
+ || !DECL_MODULE_IMPORT_P (inner))
+ return NULL_TREE;
+
+ /* Imported temploid friends are not considered as attached to this
+ module for merging purposes. */
+ tree bind = get_mergeable_namespace_binding (current_namespace,
+ DECL_NAME (inner), false);
+ if (!bind)
+ return NULL_TREE;
+
+ /* We're only interested in declarations coming from the same module
+ of the friend class we're attempting to instantiate. */
+ int m = get_originating_module (friend_tmpl);
+ gcc_assert (m != 0);
+
+ /* There should be at most one class template from the module we're
+ looking for, return it. */
+ for (ovl_iterator iter (bind); iter; ++iter)
+ if (DECL_CLASS_TEMPLATE_P (*iter)
+ && get_originating_module (*iter) == m)
+ return *iter;
+
+ return NULL_TREE;
+}
+
/* true means unconditionally make a BLOCK for the next level pushed. */
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 3b2106dd3f6..1c3eef60c06 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -11512,6 +11512,10 @@ tsubst_friend_function (tree decl, tree args)
new_friend_result_template_info = DECL_TEMPLATE_INFO (not_tmpl);
}
+ /* We need to propagate module attachment for the new friend from the
+ owner of this template. */
+ propagate_defining_module (new_friend, decl);
+
/* Inside pushdecl_namespace_level, we will push into the
current namespace. However, the friend function should go
into the namespace of the template. */
@@ -11715,6 +11719,12 @@ tsubst_friend_class (tree friend_tmpl, tree args)
tmpl = lookup_name (DECL_NAME (friend_tmpl), LOOK_where::CLASS_NAMESPACE,
LOOK_want::NORMAL | LOOK_want::HIDDEN_FRIEND);
+ if (!tmpl)
+ /* If we didn't find by name lookup, the type may still exist but as a
+ 'hidden' import; we should check for this too to avoid accidentally
+ instantiating a duplicate. */
+ tmpl = lookup_imported_hidden_friend (friend_tmpl);
+
if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
{
/* The friend template has already been declared. Just
@@ -11723,6 +11733,12 @@ tsubst_friend_class (tree friend_tmpl, tree args)
of course. We only need the innermost template parameters
because that is all that redeclare_class_template will look
at. */
+
+ if (modules_p ())
+ /* Check that the existing declaration's module attachment is
+ compatible with the attachment of the friend template. */
+ module_may_redeclare (tmpl, friend_tmpl);
+
if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
> TMPL_ARGS_DEPTH (args))
{
@@ -11751,9 +11767,16 @@ tsubst_friend_class (tree friend_tmpl, tree args)
if (tmpl != error_mark_node)
{
/* The new TMPL is not an instantiation of anything, so we
- forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE
+ forget its origins. It is also not a specialization of
+ anything. We don't reset CLASSTYPE_TI_TEMPLATE
for the new type because that is supposed to be the
corresponding template decl, i.e., TMPL. */
+ spec_entry elt;
+ elt.tmpl = friend_tmpl;
+ elt.args = CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl));
+ elt.spec = TREE_TYPE (tmpl);
+ type_specializations->remove_elt (&elt);
+
DECL_USE_TEMPLATE (tmpl) = 0;
DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
@@ -11772,6 +11795,10 @@ tsubst_friend_class (tree friend_tmpl, tree args)
args, tf_warning_or_error);
}
+ /* We need to propagate the attachment of the original template to the
+ newly instantiated template type. */
+ propagate_defining_module (tmpl, friend_tmpl);
+
/* Inject this template into the enclosing namspace scope. */
tmpl = pushdecl_namespace_level (tmpl, /*hiding=*/true);
}
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-10_a.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-10_a.C
new file mode 100644
index 00000000000..7547326e554
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-10_a.C
@@ -0,0 +1,15 @@
+// PR c++/105320
+// { dg-additional-options "-fmodules-ts -Wno-global-module" }
+// { dg-module-cmi test_support }
+
+module;
+template<class> struct _Sp_atomic;
+template<class> struct shared_ptr {
+ template<class> friend struct _Sp_atomic;
+ using atomic_type = _Sp_atomic<int>;
+};
+export module test_support;
+export
+template<class T> struct A {
+ shared_ptr<T> data;
+};
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-10_b.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-10_b.C
new file mode 100644
index 00000000000..6b88ee4258b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-10_b.C
@@ -0,0 +1,5 @@
+// PR c++/105320
+// { dg-additional-options "-fmodules-ts" }
+
+import test_support;
+A<int> a;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-10_c.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-10_c.C
new file mode 100644
index 00000000000..90bcd18a45e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-10_c.C
@@ -0,0 +1,7 @@
+// PR c++/105320
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi user:part }
+
+export module user:part;
+import test_support;
+export A<int> b;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-10_d.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-10_d.C
new file mode 100644
index 00000000000..861d19c9eaa
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-10_d.C
@@ -0,0 +1,8 @@
+// PR c++/105320
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi user }
+
+export module user;
+export import :part;
+import test_support;
+A<double> c;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-11_a.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-11_a.C
new file mode 100644
index 00000000000..f29eebd1a7f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-11_a.C
@@ -0,0 +1,14 @@
+// PR c++/114275
+// { dg-additional-options "-fmodules-ts -Wno-global-module" }
+// { dg-module-cmi M }
+
+module;
+
+template <typename... _Elements> struct T;
+
+template <typename H> struct T<H> {
+ template <typename...> friend struct T;
+};
+
+export module M;
+export template <typename=void> void fun() { T<int> t; }
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-11_b.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-11_b.C
new file mode 100644
index 00000000000..5bf79998139
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-11_b.C
@@ -0,0 +1,5 @@
+// PR c++/114275
+// { dg-additional-options "-fmodules-ts" }
+
+import M;
+int main() { fun(); }
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-12_a.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-12_a.C
new file mode 100644
index 00000000000..216dbf62c71
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-12_a.C
@@ -0,0 +1,10 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M:A }
+
+module M:A;
+
+template <typename T> struct A {
+ template <typename U> friend struct B;
+private:
+ int x = 42;
+};
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-12_b.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-12_b.C
new file mode 100644
index 00000000000..26e1c38b518
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-12_b.C
@@ -0,0 +1,9 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M:B }
+
+export module M:B;
+import :A;
+
+export template <typename U> struct B {
+ int foo(A<U> a) { return a.x; }
+};
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-12_c.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-12_c.C
new file mode 100644
index 00000000000..e44c2819cfd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-12_c.C
@@ -0,0 +1,10 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M:C }
+
+export module M:C;
+import :A;
+
+template <typename T> struct B;
+export template <typename T, typename U> int bar(B<T> t, U u) {
+ return t.foo(u);
+}
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-12_d.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-12_d.C
new file mode 100644
index 00000000000..9a575ad5046
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-12_d.C
@@ -0,0 +1,8 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M }
+
+export module M;
+export import :B;
+export import :C;
+
+export int go_in_module();
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-12_e.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-12_e.C
new file mode 100644
index 00000000000..329d1e8b263
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-12_e.C
@@ -0,0 +1,7 @@
+// { dg-additional-options "-fmodules-ts" }
+
+module M;
+
+int go_in_module() {
+ return bar(B<int>{}, A<int>{});
+}
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-12_f.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-12_f.C
new file mode 100644
index 00000000000..c9855663fbd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-12_f.C
@@ -0,0 +1,8 @@
+// { dg-additional-options "-fmodules-ts" }
+
+import M;
+
+int main() {
+ B<double> b{};
+ go_in_module();
+}
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-13_a.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-13_a.C
new file mode 100644
index 00000000000..8c972776d60
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-13_a.C
@@ -0,0 +1,13 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M }
+
+export module M;
+export template <typename> struct A {
+ friend struct S;
+ template <typename> friend struct T;
+};
+
+export template <typename> struct B {
+ friend void f();
+ template <typename> friend void g();
+};
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-13_b.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-13_b.C
new file mode 100644
index 00000000000..0e27e97b113
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-13_b.C
@@ -0,0 +1,11 @@
+// { dg-additional-options "-fmodules-ts" }
+
+import M;
+
+A<int> a;
+struct S {}; // { dg-error "conflicts with import" }
+template <typename> struct T {}; // { dg-error "conflicts with import" }
+
+B<int> c;
+void f() {} // { dg-error "conflicts with import" }
+template <typename> void g() {} // { dg-error "conflicts with import" }
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-13_c.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-13_c.C
new file mode 100644
index 00000000000..3464aa26bf8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-13_c.C
@@ -0,0 +1,13 @@
+// { dg-additional-options "-fmodules-ts" }
+
+import M;
+
+struct S {}; // { dg-error "conflicts with import" }
+template <typename> struct T {}; // { dg-message "previously declared" }
+A<int> a; // { dg-message "required from here" }
+
+void f() {} // { dg-message "previously declared" }
+template <typename> void g() {} // { dg-message "previously declared" }
+B<int> b; // { dg-message "required from here" }
+
+// { dg-error "conflicting declaration" "" { target *-*-* } 0 }
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-13_d.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-13_d.C
new file mode 100644
index 00000000000..5b935474ab2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-13_d.C
@@ -0,0 +1,7 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi X }
+
+export module X;
+export import M;
+A<int> ax;
+B<int> bx;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-13_e.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-13_e.C
new file mode 100644
index 00000000000..afbd0a39c23
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-13_e.C
@@ -0,0 +1,18 @@
+// { dg-additional-options "-fmodules-ts" }
+
+// 'import X' does not correctly notice that S has already been declared.
+struct S {}; // { dg-message "previously declared" "" { xfail *-*-* } }
+template <typename> struct T {}; // { dg-message "previously declared" }
+void f() {} // { dg-message "previously declared" }
+template <typename T> void g() {} // { dg-message "previously declared" }
+
+import X;
+A<double> a2; // { dg-message "required from here" }
+B<double> b2; // { dg-message "required from here" }
+
+// specifically, S and T are defined in M, not X, despite the instantiation
being in X
+// { dg-error "conflicting declaration \[^\n\r\]* S@M" "" { xfail *-*-* } 0 }
+// { dg-error "conflicting declaration \[^\n\r\]* T@M" "" { target *-*-* } 0 }
+// and similarly for f and g
+// { dg-error "conflicting declaration \[^\n\r\]* f@M" "" { target *-*-* } 0 }
+// { dg-error "conflicting declaration \[^\n\r\]* g@M" "" { target *-*-* } 0 }
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-13_f.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-13_f.C
new file mode 100644
index 00000000000..287f95c7bdc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-13_f.C
@@ -0,0 +1,7 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi Y }
+
+export module Y;
+export import M;
+A<double> ay;
+B<double> by;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-13_g.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-13_g.C
new file mode 100644
index 00000000000..b7da60f2322
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-13_g.C
@@ -0,0 +1,11 @@
+// { dg-additional-options "-fmodules-ts" }
+
+import X;
+import Y;
+
+// This should happily refer to the same S and T
+// as already instantiated in both X and Y
+A<long> az;
+
+// And same for f and g
+B<long> bz;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-14_a.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-14_a.C
new file mode 100644
index 00000000000..6912512ecf7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-14_a.C
@@ -0,0 +1,8 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M }
+
+export module M;
+
+export extern "C++" template <typename> struct A {
+ template <typename> friend struct B;
+};
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-14_b.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-14_b.C
new file mode 100644
index 00000000000..5f8aa7fd62e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-14_b.C
@@ -0,0 +1,8 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi X }
+
+export module X;
+export import M;
+
+A<int> x;
+export extern "C++" template <typename T> struct B { using type = T; };
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-14_c.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-14_c.C
new file mode 100644
index 00000000000..8d89298878a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-14_c.C
@@ -0,0 +1,7 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi Y }
+
+export module Y;
+export import M;
+
+A<double> x;
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-14_d.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-14_d.C
new file mode 100644
index 00000000000..7a842586b62
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-14_d.C
@@ -0,0 +1,9 @@
+// { dg-additional-options "-fmodules-ts" }
+
+import X;
+import Y;
+
+int main() {
+ A<long> a;
+ B<int>::type r = 10;
+}
diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-9.C
b/gcc/testsuite/g++.dg/modules/tpl-friend-9.C
new file mode 100644
index 00000000000..c7216f0f8c1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/tpl-friend-9.C
@@ -0,0 +1,13 @@
+// PR c++/114275
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi M }
+
+export module M;
+
+template<class> struct A {
+ template<class> friend struct B;
+ friend void C();
+};
+A<int> a;
+void C() {}
+template<class> struct B { };
