From 1e166191ef330f3491d405bf3eb09b2b796c9b0e Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Sat, 15 Feb 2020 14:48:08 +0100 Subject: [PATCH] c++: Fix lambda in atomic constraint. find_template_parameters needs to find the mention of T in the lambda. Fixing that leaves this as a hard error, which may be surprising but is consistent with lambdas in other SFINAE contexts like template argument deduction. gcc/cp/ChangeLog 2020-02-15 Jason Merrill PR c++/92556 * pt.c (any_template_parm_r): Look into lambda body. --- gcc/cp/ChangeLog | 3 +++ gcc/cp/pt.c | 9 +++++++++ gcc/testsuite/g++.dg/cpp2a/concepts-lambda5.C | 10 ++++++++++ 3 files changed, 22 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-lambda5.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index ed6b0d0..6ac938b 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,5 +1,8 @@ 2020-02-15 Jason Merrill + PR c++/92556 + * pt.c (any_template_parm_r): Look into lambda body. + PR c++/92583 * pt.c (any_template_parm_r): Remove CONSTRUCTOR handling. diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index d19bde7..6c9abb8 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -10479,6 +10479,15 @@ any_template_parm_r (tree t, void *data) } break; + case LAMBDA_EXPR: + { + /* Look in the parms and body. */ + tree fn = lambda_function (t); + WALK_SUBTREE (TREE_TYPE (fn)); + WALK_SUBTREE (DECL_SAVED_TREE (fn)); + } + break; + default: break; } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-lambda5.C b/gcc/testsuite/g++.dg/cpp2a/concepts-lambda5.C new file mode 100644 index 0000000..fe47189 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-lambda5.C @@ -0,0 +1,10 @@ +// PR c++/92556 +// { dg-do compile { target c++2a } } + +// Having this as a hard error is consistent with template argument deduction; +// it's an open core issue (jason 2020-02-14). +template concept has_value + = requires { []{T::value;}; }; // { dg-error "" } +template void f() { } +template void f() { } +void q() { f(); } -- 2.7.4