From f9f166251f181ddcee64092d89aecbc1166ca706 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Thu, 23 Apr 2020 17:29:55 -0400 Subject: [PATCH] c++: Lambda in friend of constrained class [PR94645] In the testcase below, when grokfndecl processes the operator() decl for the lambda inside the friend function foo, processing_template_decl is rightly 1, but template_class_depth on the lambda's closure type incorrectly returns 0 instead of 1. Since processing_template_decl > template_class_depth, this makes grokfndecl think that the operator() has its own set of template arguments, and so we attach the innermost set of constraints -- those belonging to struct l -- to the operator() decl. We then get confused when checking constraints_satisfied_p on the operator() because it doesn't have template information and yet has constraints associated with it. This patch fixes template_class_depth to return the correct template nesting level in cases like these, in that when it hits a friend function it walks into the DECL_FRIEND_CONTEXT of the friend rather than into the CP_DECL_CONTEXT. gcc/cp/ChangeLog: PR c++/94645 * pt.c (template_class_depth): Walk into the DECL_FRIEND_CONTEXT of a friend declaration rather than into its CP_DECL_CONTEXT. gcc/testsuite/ChangeLog: PR c++/94645 * g++.dg/cpp2a/concepts-lambda6.C: New test. --- gcc/cp/ChangeLog | 6 ++++++ gcc/cp/pt.c | 7 ++++++- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/cpp2a/concepts-lambda6.C | 19 +++++++++++++++++++ 4 files changed, 36 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-lambda6.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index fa150e3462f..6506f288e05 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-04-23 Patrick Palka + + PR c++/94645 + * pt.c (template_class_depth): Walk into the DECL_FRIEND_CONTEXT of a + friend declaration rather than into its CP_DECL_CONTEXT. + 2020-04-23 Iain Sandoe PR c++/94288 diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 2fe7b66707c..66308a2d295 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -390,7 +390,12 @@ template_class_depth (tree type) ++depth; if (DECL_P (type)) - type = CP_DECL_CONTEXT (type); + { + if (tree fctx = DECL_FRIEND_CONTEXT (type)) + type = fctx; + else + type = CP_DECL_CONTEXT (type); + } else if (LAMBDA_TYPE_P (type) && LAMBDA_TYPE_EXTRA_SCOPE (type)) type = LAMBDA_TYPE_EXTRA_SCOPE (type); else diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index f9ab061922e..e0df5bc0a99 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-04-23 Patrick Palka + + PR c++/94645 + * g++.dg/cpp2a/concepts-lambda6.C: New test. + 2019-04-23 Eric Botcazou * g++.dg/opt/store-merging-4.C: New test. diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-lambda6.C b/gcc/testsuite/g++.dg/cpp2a/concepts-lambda6.C new file mode 100644 index 00000000000..0b7c04562e9 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-lambda6.C @@ -0,0 +1,19 @@ +// PR c++/94645 +// { dg-do compile { target concepts } } + +struct unordered_map { + int cend() const noexcept; +}; + +template concept HasMapInterface = requires(a t) { t.cend(); }; + +template requires HasMapInterface +struct l { + friend void foo(l opt) { ([]() {})(); } +}; + +struct p { + static unordered_map map(); +}; + +void g(l

*y) { foo(*y); } -- 2.30.2