From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1888) id 5F4723857703; Sun, 24 Sep 2023 18:42:49 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5F4723857703 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1695580969; bh=bh5AI7tZqeGcp4VhgloLN1oeY3jRo1t5af9owSqxnEI=; h=From:To:Subject:Date:From; b=o1H6y+FQCM/kVl0HZwLvSoGqXRtxVlh0OubGxMw1JwPxSN5ovRPUefo4ee2CR8q9U Ykts5BQmIzSPyYUWNMr4/JrhxL9gWnvqqkLRxIfkhpdeZoMJJeEhrniNAcCS7QhOre 3g5rRKBkF9d6PmJMS/McmpW4gZF0ysloICN3VNNA= 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 r13-7836] c++: constraint rewriting during ttp coercion [PR111485] X-Act-Checkin: gcc X-Git-Author: Patrick Palka X-Git-Refname: refs/heads/releases/gcc-13 X-Git-Oldrev: b9e02590f7d35f1f8e8e95ab1f2e30f24113f551 X-Git-Newrev: 59f5786c20a42be13ac6fec567ffe840045012ad Message-Id: <20230924184249.5F4723857703@sourceware.org> Date: Sun, 24 Sep 2023 18:42:49 +0000 (GMT) List-Id: https://gcc.gnu.org/g:59f5786c20a42be13ac6fec567ffe840045012ad commit r13-7836-g59f5786c20a42be13ac6fec567ffe840045012ad Author: Patrick Palka Date: Fri Sep 22 06:25:49 2023 -0400 c++: constraint rewriting during ttp coercion [PR111485] In order to compare the constraints of a ttp with that of its argument, we rewrite the ttp's constraints in terms of the argument template's template parameters. The substitution to achieve this currently uses a single level of template arguments, but that never does the right thing because a ttp's template parameters always have level >= 2. This patch fixes this by including the outer template arguments in the substitution, which ought to match the depth of the ttp. The second testcase demonstrates it's better to substitute the concrete outer template arguments instead of generic ones since a ttp's constraints could depend on outer parameters. PR c++/111485 gcc/cp/ChangeLog: * pt.cc (is_compatible_template_arg): New parameter 'args'. Add the outer template arguments 'args' to 'new_args'. (convert_template_argument): Pass 'args' to is_compatible_template_arg. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-ttp5.C: New test. * g++.dg/cpp2a/concepts-ttp6.C: New test. (cherry picked from commit 6f902a42b0afe3f3145bcb864695fc290b5acc3e) Diff: --- gcc/cp/pt.cc | 5 +++-- gcc/testsuite/g++.dg/cpp2a/concepts-ttp5.C | 24 ++++++++++++++++++++++++ gcc/testsuite/g++.dg/cpp2a/concepts-ttp6.C | 17 +++++++++++++++++ 3 files changed, 44 insertions(+), 2 deletions(-) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index bf2dbd681ac..174567fc1ec 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -8334,7 +8334,7 @@ canonicalize_expr_argument (tree arg, tsubst_flags_t complain) constrained than the parameter. */ static bool -is_compatible_template_arg (tree parm, tree arg) +is_compatible_template_arg (tree parm, tree arg, tree args) { tree parm_cons = get_constraints (parm); @@ -8355,6 +8355,7 @@ is_compatible_template_arg (tree parm, tree arg) { tree aparms = DECL_INNERMOST_TEMPLATE_PARMS (arg); new_args = template_parms_level_to_args (aparms); + new_args = add_to_template_args (args, new_args); ++processing_template_decl; parm_cons = tsubst_constraint_info (parm_cons, new_args, tf_none, NULL_TREE); @@ -8609,7 +8610,7 @@ convert_template_argument (tree parm, // Check that the constraints are compatible before allowing the // substitution. if (val != error_mark_node) - if (!is_compatible_template_arg (parm, arg)) + if (!is_compatible_template_arg (parm, arg, args)) { if (in_decl && (complain & tf_error)) { diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ttp5.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp5.C new file mode 100644 index 00000000000..abc22ce59d8 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp5.C @@ -0,0 +1,24 @@ +// PR c++/111485 +// { dg-do compile { target c++20 } } + +template constexpr bool always_true = true; + +template concept C = always_true; +template concept D = C || true; + +template class TT> struct example; +template class UU> using example_t = example; + +template +struct A { + template class TT> struct example; + + template class UU> using example_t = example; + + template + struct B { + template class UU> using example_t = example; + }; +}; + +template struct A::B; diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-ttp6.C b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp6.C new file mode 100644 index 00000000000..6396e99cc05 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-ttp6.C @@ -0,0 +1,17 @@ +// PR c++/111485 +// { dg-do compile { target c++20 } } + +template constexpr bool always_true = true; + +template concept C = always_true; + +template requires C class TT> +void f(); + +template requires C +struct A; + +int main() { + f(); + f(); // { dg-error "no match|constraint mismatch" } +}