From 7ce078ceca42f184f6f60c3ca921b6e07cf2c4bd Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Wed, 3 May 2023 13:32:55 -0400
Subject: [PATCH] c++: over-eager friend matching [PR109649]
A bug in the simplification I did around 91618; at this point X<int>::f has
DECL_IMPLICIT_INSTANTIATION set, but we've already identified what template
it corresponds to, so we don't want to call check_explicit_specialization.
To distinguish this case we need to look at DECL_TI_TEMPLATE. grokfndecl
has for a long time set it to the OVERLOAD in this case, while the new cases
I added for 91618 were leaving DECL_TEMPLATE_INFO null; let's adjust them to
match.
PR c++/91618
PR c++/109649
gcc/cp/ChangeLog:
* friend.cc (do_friend): Don't call check_explicit_specialization if
DECL_TEMPLATE_INFO is already set.
* decl2.cc (check_classfn): Set DECL_TEMPLATE_INFO.
* name-lookup.cc (set_decl_namespace): Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/template/friend77.C: New test.
---
gcc/cp/decl2.cc | 1 +
gcc/cp/friend.cc | 3 ++-
gcc/cp/name-lookup.cc | 1 +
gcc/testsuite/g++.dg/template/friend77.C | 19 +++++++++++++++++++
4 files changed, 23 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/template/friend77.C
diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index 9594be4092c3..b510cdac5541 100644
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -855,6 +855,7 @@ check_classfn (tree ctype, tree function, tree template_parms)
So tell check_explicit_specialization to look for a match. */
SET_DECL_IMPLICIT_INSTANTIATION (function);
+ DECL_TEMPLATE_INFO (function) = build_template_info (fns, NULL_TREE);
matched = function;
}
diff --git a/gcc/cp/friend.cc b/gcc/cp/friend.cc
index b36de2b20bba..5ab5c1fec730 100644
--- a/gcc/cp/friend.cc
+++ b/gcc/cp/friend.cc
@@ -661,7 +661,8 @@ do_friend (tree scope, tree declarator, tree decl,
if (decl == error_mark_node)
return error_mark_node;
- if (!class_template_depth && DECL_IMPLICIT_INSTANTIATION (decl))
+ if (!class_template_depth && DECL_IMPLICIT_INSTANTIATION (decl)
+ && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
/* "[if no non-template match is found,] each remaining function template
is replaced with the specialization chosen by deduction from the
friend declaration or discarded if deduction fails."
diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 8fd5733c1e24..ad03141df430 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -5938,6 +5938,7 @@ set_decl_namespace (tree decl, tree scope, bool friendp)
So tell check_explicit_specialization to look for a match. */
SET_DECL_IMPLICIT_INSTANTIATION (decl);
+ DECL_TEMPLATE_INFO (decl) = build_template_info (old, NULL_TREE);
return;
}
diff --git a/gcc/testsuite/g++.dg/template/friend77.C b/gcc/testsuite/g++.dg/template/friend77.C
new file mode 100644
index 000000000000..f232cb107563
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/friend77.C
@@ -0,0 +1,19 @@
+// PR c++/109649
+
+template <typename>
+class X
+{
+ void f(){}
+};
+
+class Y
+{
+ friend void X<int>::f(); // { dg-error "private" }
+};
+
+int main()
+{
+ X<int> t;
+ t.f(); // { dg-error "private" }
+ Y b;
+}
--
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