From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1888) id 0E1F6398CC23; Fri, 9 Jul 2021 14:22:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0E1F6398CC23 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Patrick Palka To: gcc-cvs@gcc.gnu.org Subject: [gcc r12-2221] c++: find_template_parameters and TEMPLATE_DECLs [PR101247] X-Act-Checkin: gcc X-Git-Author: Patrick Palka X-Git-Refname: refs/heads/master X-Git-Oldrev: 2e345e4ad6bb6595a9e3b182aa349d4f306b0921 X-Git-Newrev: f53e66019df819f55d424cc56f8b0ea81c074b55 Message-Id: <20210709142250.0E1F6398CC23@sourceware.org> Date: Fri, 9 Jul 2021 14:22:50 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Jul 2021 14:22:50 -0000 https://gcc.gnu.org/g:f53e66019df819f55d424cc56f8b0ea81c074b55 commit r12-2221-gf53e66019df819f55d424cc56f8b0ea81c074b55 Author: Patrick Palka Date: Fri Jul 9 10:20:22 2021 -0400 c++: find_template_parameters and TEMPLATE_DECLs [PR101247] r12-1989 fixed the testcase in the PR, but unfortunately the fix is buggy: it breaks the case where the common template between the TEMPLATE_DECL t and ctx_parms is the innermost template (as in concepts-memtmpl5.C below). This can be fixed by instead passing the TREE_TYPE of ctmpl to common_enclosing_class when ctmpl is a class template. But even after that's fixed, the analogous case where the innermost template is a partial specialization is still broken (as in concepts-memtmpl5a.C below), because ctmpl is always a primary template. So this patch instead takes a diferent approach that doesn't rely on ctx_parms at all: when looking for the template parameters of a TEMPLATE_DECL that are shared with the current template context, just walk its DECL_CONTEXT. As long as the template is not overly general (e.g. we didn't pass it through most_general_template), this should give us exactly what we want, since if a TEMPLATE_DECL can be referred to from some template context then the template parameters it uses must all be in-scope and contained in its DECL_CONTEXT. This effectively makes us treat TEMPLATE_DECLs more similarly to other _DECLs (whose DECL_CONTEXT we also walk). PR c++/101247 gcc/cp/ChangeLog: * pt.c (any_template_parm_r) : Just walk the DECL_CONTEXT. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-memtmpl4.C: Uncomment the commented out example, which we now handle correctly. * g++.dg/cpp2a/concepts-memtmpl5.C: New test. * g++.dg/cpp2a/concepts-memtmpl5a.C: New test. Diff: --- gcc/cp/pt.c | 14 +++++--------- gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C | 2 +- gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C | 11 +++++++++++ gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C | 15 +++++++++++++++ 4 files changed, 32 insertions(+), 10 deletions(-) diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 7e56ccfc45f..dc0f0b7b58e 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -10728,15 +10728,11 @@ any_template_parm_r (tree t, void *data) break; case TEMPLATE_DECL: - { - /* If T is a member template that shares template parameters with - ctx_parms, we need to mark all those parameters for mapping. */ - if (tree ctmpl = TREE_TYPE (INNERMOST_TEMPLATE_PARMS (ftpi->ctx_parms))) - if (tree com = common_enclosing_class (DECL_CONTEXT (t), - DECL_CONTEXT (ctmpl))) - if (tree ti = CLASSTYPE_TEMPLATE_INFO (com)) - WALK_SUBTREE (TI_ARGS (ti)); - } + /* If T is a member template that shares template parameters with + ctx_parms, we need to mark all those parameters for mapping. + To that end, it should suffice to just walk the DECL_CONTEXT of + the template (assuming the template is not overly general). */ + WALK_SUBTREE (DECL_CONTEXT (t)); break; case LAMBDA_EXPR: diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C index 625149e5025..f990ae17859 100644 --- a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl4.C @@ -24,5 +24,5 @@ int main() { A::B::f(0); A::C::f(0); - // A::C::g(); + A::C::g(); } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C new file mode 100644 index 00000000000..3c83bb88485 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5.C @@ -0,0 +1,11 @@ +// PR c++/101247 +// { dg-do compile { target concepts } } + +template struct A { + template static constexpr bool d = true; + static void g() requires d; +}; + +int main() { + A::g(); +} diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C new file mode 100644 index 00000000000..458f1cdf856 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memtmpl5a.C @@ -0,0 +1,15 @@ +// PR c++/101247 +// { dg-do compile { target concepts } } +// A variant of concepts-memtmpl5.C that uses a partial specialization +// of A instead of the primary template. + +template struct A; + +template requires true struct A { + template static constexpr bool d = true; + static void g() requires d; +}; + +int main() { + A::g(); +}