From 92a38cfd775c045d7ed8b989b231410849fc22fe Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Mon, 4 Jun 2018 09:22:52 -0400 Subject: [PATCH] PR c++/85765 - SFINAE and non-type default template arg. * pt.c (type_unification_real): Do full semantic processing if substituting a partial args list replaces all template parms. From-SVN: r261146 --- gcc/cp/ChangeLog | 6 +++++ gcc/cp/pt.c | 30 +++++++++++++++++----- gcc/testsuite/g++.dg/cpp0x/fntmpdefarg10.C | 18 +++++++++++++ 3 files changed, 47 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/fntmpdefarg10.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 5d4caccdb39..773e9334a5e 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2018-06-04 Jason Merrill + + PR c++/85765 - SFINAE and non-type default template arg. + * pt.c (type_unification_real): Do full semantic processing if + substituting a partial args list replaces all template parms. + 2018-06-03 Jason Merrill PR c++/85739 - ICE with pointer to member template parm. diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 4c5890deeb8..d3915ddcddf 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -20387,8 +20387,6 @@ type_unification_real (tree tparms, location_t save_loc = input_location; if (DECL_P (parm)) input_location = DECL_SOURCE_LOCATION (parm); - if (saw_undeduced == 1) - ++processing_template_decl; if (saw_undeduced == 1 && TREE_CODE (parm) == PARM_DECL @@ -20396,11 +20394,14 @@ type_unification_real (tree tparms, { /* The type of this non-type parameter depends on undeduced parameters. Don't try to use its default argument yet, + since we might deduce an argument for it on the next pass, but do check whether the arguments we already have cause substitution failure, so that that happens before we try later default arguments (78489). */ + ++processing_template_decl; tree type = tsubst (TREE_TYPE (parm), full_targs, complain, NULL_TREE); + --processing_template_decl; if (type == error_mark_node) arg = error_mark_node; else @@ -20408,10 +20409,27 @@ type_unification_real (tree tparms, } else { - arg = tsubst_template_arg (arg, full_targs, complain, NULL_TREE); + tree substed = NULL_TREE; + if (saw_undeduced == 1 && processing_template_decl == 0) + { + /* First instatiate in template context, in case we still + depend on undeduced template parameters. */ + ++processing_template_decl; + substed = tsubst_template_arg (arg, full_targs, complain, + NULL_TREE); + --processing_template_decl; + if (substed != error_mark_node + && !uses_template_parms (substed)) + /* We replaced all the tparms, substitute again out of + template context. */ + substed = NULL_TREE; + } + if (!substed) + substed = tsubst_template_arg (arg, full_targs, complain, + NULL_TREE); - if (!uses_template_parms (arg)) - arg = convert_template_argument (parm, arg, full_targs, + if (!uses_template_parms (substed)) + arg = convert_template_argument (parm, substed, full_targs, complain, i, NULL_TREE); else if (saw_undeduced == 1) arg = NULL_TREE; @@ -20419,8 +20437,6 @@ type_unification_real (tree tparms, arg = error_mark_node; } - if (saw_undeduced == 1) - --processing_template_decl; input_location = save_loc; *checks = get_deferred_access_checks (); pop_deferring_access_checks (); diff --git a/gcc/testsuite/g++.dg/cpp0x/fntmpdefarg10.C b/gcc/testsuite/g++.dg/cpp0x/fntmpdefarg10.C new file mode 100644 index 00000000000..f0f9dfb73dc --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/fntmpdefarg10.C @@ -0,0 +1,18 @@ +// PR c++/85765 +// { dg-do compile { target c++11 } } + +struct il { il(); il(const il&); }; + +int* begin(il); + +template T&& declval(); + +template())), decltype(*U(),0) = 0> +U g(T& t, long) { return begin(t); } // #1 + +template +int g(T& t, ...); // #2 + +volatile il a; + +auto n = g(a, 0); // calls #1 and ends with a hard error, should call #2 -- 2.30.2