From 0dfbb28a9549c2503204b0338bf550f1bff9c681 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Mon, 3 Apr 2023 18:23:58 -0400
Subject: [PATCH] c++: friend template matching [PR107484]
Here friend matching tries to find a matching non-template friend and fails,
so we mark the friend as a template specialization to be determined later.
Then cplus_decl_attributes tries again to find a matching function and gets
confused by DECL_TEMPLATE_INSTANTIATION without DECL_TEMPLATE_INFO. But it
doesn't make sense for find_last_decl to be trying to match anything with
DECL_USE_TEMPLATE set; those are matched elsewhere.
PR c++/107484
gcc/cp/ChangeLog:
* decl2.cc (find_last_decl): Return early if DECL_USE_TEMPLATE.
gcc/testsuite/ChangeLog:
* g++.dg/lookup/friend25.C: New test.
---
gcc/cp/decl2.cc | 5 +++++
gcc/testsuite/g++.dg/lookup/friend25.C | 9 +++++++++
2 files changed, 14 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/lookup/friend25.C
diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index 2b195e999975..9594be4092c3 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -1613,6 +1613,11 @@ find_last_decl (tree decl)
if (tree name = DECL_P (decl) ? DECL_NAME (decl) : NULL_TREE)
{
+ /* Template specializations are matched elsewhere. */
+ if (DECL_LANG_SPECIFIC (decl)
+ && DECL_USE_TEMPLATE (decl))
+ return NULL_TREE;
+
/* Look up the declaration in its scope. */
tree pushed_scope = NULL_TREE;
if (tree ctype = DECL_CONTEXT (decl))
diff --git a/gcc/testsuite/g++.dg/lookup/friend25.C b/gcc/testsuite/g++.dg/lookup/friend25.C
new file mode 100644
index 000000000000..74cf5dc34319
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/friend25.C
@@ -0,0 +1,9 @@
+// PR c++/107484
+
+namespace qualified_friend_no_match {
+ void f(int);
+ template<typename T> void f(T*);
+ struct X {
+ friend void qualified_friend_no_match::f(double); // { dg-error "does not match any template" }
+ };
+}
--
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