From c393c99d3dc8329dc1a36011e70faa9700185051 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Sat, 14 Mar 2020 17:10:39 -0400 Subject: [PATCH] c++: Fix CTAD with multiple-arg ctor template [93248]. When cp_unevaluated_operand is set, tsubst_decl thinks that if it sees a PARM_DECL that isn't already in local_specializations, we're in a decltype in a trailing return type or some such, and so we only want a substitution for a single PARM_DECL. In this case, we want the whole chain, so make sure cp_unevaluated_operand is cleared. gcc/cp/ChangeLog 2020-03-14 Jason Merrill PR c++/93248 * pt.c (build_deduction_guide): Clear cp_unevaluated_operand for substituting DECL_ARGUMENTS. --- gcc/cp/ChangeLog | 6 ++++++ gcc/cp/pt.c | 5 ++++- gcc/testsuite/g++.dg/cpp1z/class-deduction71.C | 6 ++++++ 3 files changed, 16 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp1z/class-deduction71.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 79434c9d45e..b4fa15047b5 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-03-14 Jason Merrill + + PR c++/93248 + * pt.c (build_deduction_guide): Clear cp_unevaluated_operand for + substituting DECL_ARGUMENTS. + 2020-03-14 Jakub Jelinek * logic.cc (formula::formula): Change "a an" to "an" in a comment. diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 789ccdbbbd1..0f3c2ad8fec 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -28071,10 +28071,13 @@ build_deduction_guide (tree type, tree ctor, tree outer_args, tsubst_flags_t com complain, ctor); if (fparms == error_mark_node) ok = false; - fargs = tsubst (fargs, tsubst_args, complain, ctor); if (ci) ci = tsubst_constraint_info (ci, tsubst_args, complain, ctor); + /* Parms are to have DECL_CHAIN tsubsted, which would be skipped if + cp_unevaluated_operand. */ + cp_evaluated ev; + fargs = tsubst (fargs, tsubst_args, complain, ctor); current_template_parms = save_parms; } diff --git a/gcc/testsuite/g++.dg/cpp1z/class-deduction71.C b/gcc/testsuite/g++.dg/cpp1z/class-deduction71.C new file mode 100644 index 00000000000..2fc71de8d95 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/class-deduction71.C @@ -0,0 +1,6 @@ +// PR c++/93248 +// { dg-do compile { target c++17 } } + +template struct S +{ template S (T, V, long = 0); }; +using U = decltype(S{0, 4u}); -- 2.30.2