From: Jason Merrill <jason@redhat.com>
To: Patrick Palka <ppalka@redhat.com>, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] c++: remove use_default_args parm of coerce_template_parms
Date: Mon, 24 Oct 2022 15:56:57 -0400 [thread overview]
Message-ID: <97401243-a3c9-733a-44fb-c5522c6efb28@redhat.com> (raw)
In-Reply-To: <20221024162726.3463437-1-ppalka@redhat.com>
On 10/24/22 12:27, Patrick Palka wrote:
> It looks like the parameter use_default_args introduced in r110693 is
> effectively unused ever since r7-5536-g3c75aaa3d884ef removed the last
> (and probably only) 'coerce_template_parms (..., true, false)' call, so
> this patch gets rid of it.
>
> In passing, I noticed we currently define wrapper overloads of
> coerce_template_parms that effectively default complain and
> require_all_args, but it seems cleaner to specify default arguments
> for the main overload instead. And I suppose we should also give
> c_innermost_t_p the same defaults.
>
> However, I'm not sure about defaulting complain to tf_none since it's
> contrary to how we default every other complain parameter to either
> tf_error or tf_warning_or_error (for sake of non-SFINAE callers), so
> this tf_none default seems surprising. And since just three callers
> (all in constraint.cc) use this complain=tf_none default, and just one
> caller (determine_specialization) passes complain=tf_warning_or_error,
> it seems best to just not default complain here.
Agreed, it's probably better in general not to default complain, that's
a source of SFINAE bugs.
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> trunk?
OK.
> gcc/cp/ChangeLog:
>
> * constraint.cc (resolve_function_concept_overload): Explicitly
> pass tf_none to coerce_template_parms.
> (resolve_concept_check): Likewise.
> (normalize_concept_check): Likewise.
> * cp-tree.h (coerce_template_parms): Declare the main overload
> and default its last parameter to true. Remove other overloads.
> * pt.cc (determine_specialization): Adjust calls to
> coerce_template_parms and coerce_innermost_template_parms after
> removing their last parameter.
> (coerce_template_args_for_ttp): Likewise.
> (coerce_ttp_args_for_tta): Likewise.
> (coerce_template_template_parms): Likewise.
> (coerce_template_parms): Remove use_default_args parameter.
> Remove wrapper overloads. No longer static.
> (coerce_innermost_template_parms): Remove use_default_args
> parameter.
> (lookup_template_class): As with determine_specialization.
> (finish_template_variable): Likewise.
> (tsubst_decl): Likewise.
> (instantiate_alias_template): Likewise.
> (fn_type_unification): Likewise.
> (resolve_overloaded_unification): Likewise.
> (resolve_nondeduced_context): Likewise.
> (get_partial_spec_bindings): Likewise.
> ---
> gcc/cp/constraint.cc | 6 +--
> gcc/cp/cp-tree.h | 4 +-
> gcc/cp/pt.cc | 107 +++++++++++--------------------------------
> 3 files changed, 32 insertions(+), 85 deletions(-)
>
> diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
> index 74898ca1a23..5e6a3bcf059 100644
> --- a/gcc/cp/constraint.cc
> +++ b/gcc/cp/constraint.cc
> @@ -323,7 +323,7 @@ resolve_function_concept_overload (tree ovl, tree args)
> /* Remember the candidate if we can deduce a substitution. */
> ++processing_template_decl;
> tree parms = TREE_VALUE (DECL_TEMPLATE_PARMS (tmpl));
> - if (tree subst = coerce_template_parms (parms, args, tmpl))
> + if (tree subst = coerce_template_parms (parms, args, tmpl, tf_none))
> {
> if (subst == error_mark_node)
> ++nerrs;
> @@ -404,7 +404,7 @@ resolve_concept_check (tree check)
> tree args = TREE_OPERAND (id, 1);
> tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (tmpl));
> ++processing_template_decl;
> - tree result = coerce_template_parms (parms, args, tmpl);
> + tree result = coerce_template_parms (parms, args, tmpl, tf_none);
> --processing_template_decl;
> if (result == error_mark_node)
> return error_mark_node;
> @@ -726,7 +726,7 @@ normalize_concept_check (tree check, tree args, norm_info info)
> /* Turn on template processing; coercing non-type template arguments
> will automatically assume they're non-dependent. */
> ++processing_template_decl;
> - tree subst = coerce_template_parms (parms, targs, tmpl);
> + tree subst = coerce_template_parms (parms, targs, tmpl, tf_none);
> --processing_template_decl;
> if (subst == error_mark_node)
> return error_mark_node;
> diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
> index 60a25101049..b210943ab25 100644
> --- a/gcc/cp/cp-tree.h
> +++ b/gcc/cp/cp-tree.h
> @@ -7459,8 +7459,8 @@ extern tree get_function_template_decl (const_tree);
> extern tree resolve_nondeduced_context (tree, tsubst_flags_t);
> extern tree resolve_nondeduced_context_or_error (tree, tsubst_flags_t);
> extern hashval_t iterative_hash_template_arg (tree arg, hashval_t val);
> -extern tree coerce_template_parms (tree, tree, tree);
> -extern tree coerce_template_parms (tree, tree, tree, tsubst_flags_t);
> +extern tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
> + bool = true);
> extern tree canonicalize_type_argument (tree, tsubst_flags_t);
> extern void register_local_specialization (tree, tree);
> extern tree retrieve_local_specialization (tree);
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index 1289aabec75..9882ee6d9ce 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -148,10 +148,8 @@ static void add_pending_template (tree);
> static tree reopen_tinst_level (struct tinst_level *);
> static tree tsubst_initializer_list (tree, tree);
> static tree get_partial_spec_bindings (tree, tree, tree);
> -static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
> - bool, bool);
> static tree coerce_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
> - bool, bool);
> + bool = true);
> static void tsubst_enum (tree, tree, tree);
> static bool check_instantiated_args (tree, tree, tsubst_flags_t);
> static int check_non_deducible_conversion (tree, tree, unification_kind_t, int,
> @@ -2172,8 +2170,7 @@ determine_specialization (tree template_id,
> {
> tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (fns));
> targs = coerce_template_parms (parms, explicit_targs, fns,
> - tf_warning_or_error,
> - /*req_all*/true, /*use_defarg*/true);
> + tf_warning_or_error);
> if (targs != error_mark_node
> && constraints_satisfied_p (fns, targs))
> templates = tree_cons (targs, fns, templates);
> @@ -7833,10 +7830,7 @@ coerce_template_args_for_ttp (tree templ, tree arglist,
> arglist = add_to_template_args (outer, arglist);
>
> tree parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
> - return coerce_template_parms (parmlist, arglist, templ,
> - complain,
> - /*require_all_args=*/true,
> - /*use_default_args=*/true);
> + return coerce_template_parms (parmlist, arglist, templ, complain);
> }
>
> /* A cache of template template parameters with match-all default
> @@ -7910,9 +7904,7 @@ coerce_ttp_args_for_tta (tree& arg, tree pargs, tsubst_flags_t complain)
> {
> tree aparms
> = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (arg_tmpl));
> - pargs = coerce_template_parms (aparms, pargs, arg_tmpl, complain,
> - /*require_all*/true,
> - /*use_default*/true);
> + pargs = coerce_template_parms (aparms, pargs, arg_tmpl, complain);
> }
> --processing_template_decl;
> return pargs;
> @@ -8079,8 +8071,7 @@ coerce_template_template_parms (tree parm_parms_full,
> pargs = add_to_template_args (outer_args, pargs);
> }
>
> - pargs = coerce_template_parms (arg_parms, pargs, NULL_TREE, tf_none,
> - /*require_all*/true, /*use_default*/true);
> + pargs = coerce_template_parms (arg_parms, pargs, NULL_TREE, tf_none);
> if (pargs != error_mark_node)
> {
> tree targs = make_tree_vec (nargs);
> @@ -8840,19 +8831,16 @@ pack_expansion_args_count (tree args)
> warning messages are issued under control of COMPLAIN.
>
> If REQUIRE_ALL_ARGS is false, argument deduction will be performed
> - for arguments not specified in ARGS. Otherwise, if
> - USE_DEFAULT_ARGS is true, default arguments will be used to fill in
> - unspecified arguments. If REQUIRE_ALL_ARGS is true, but
> - USE_DEFAULT_ARGS is false, then all arguments must be specified in
> - ARGS. */
> + for arguments not specified in ARGS. If REQUIRE_ALL_ARGS is true,
> + arguments not specified in ARGS must have default arguments with
> + which we'll fill in ARGS. */
>
> -static tree
> +tree
> coerce_template_parms (tree parms,
> tree args,
> tree in_decl,
> tsubst_flags_t complain,
> - bool require_all_args,
> - bool use_default_args)
> + bool require_all_args /* = true */)
> {
> int nparms, nargs, parm_idx, arg_idx, lost = 0;
> tree orig_inner_args;
> @@ -8913,9 +8901,8 @@ coerce_template_parms (tree parms,
> || (nargs < nparms - variadic_p
> && require_all_args
> && !variadic_args_p
> - && (!use_default_args
> - || (TREE_VEC_ELT (parms, nargs) != error_mark_node
> - && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
> + && (TREE_VEC_ELT (parms, nargs) != error_mark_node
> + && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs)))))
> {
> bad_nargs:
> if (complain & tf_error)
> @@ -9183,30 +9170,6 @@ coerce_template_parms (tree parms,
> return new_inner_args;
> }
>
> -/* Convert all template arguments to their appropriate types, and
> - return a vector containing the innermost resulting template
> - arguments. If any error occurs, return error_mark_node. Error and
> - warning messages are not issued.
> -
> - Note that no function argument deduction is performed, and default
> - arguments are used to fill in unspecified arguments. */
> -tree
> -coerce_template_parms (tree parms, tree args, tree in_decl)
> -{
> - return coerce_template_parms (parms, args, in_decl, tf_none, true, true);
> -}
> -
> -/* Convert all template arguments to their appropriate type, and
> - instantiate default arguments as needed. This returns a vector
> - containing the innermost resulting template arguments, or
> - error_mark_node if unsuccessful. */
> -tree
> -coerce_template_parms (tree parms, tree args, tree in_decl,
> - tsubst_flags_t complain)
> -{
> - return coerce_template_parms (parms, args, in_decl, complain, true, true);
> -}
> -
> /* Like coerce_template_parms. If PARMS represents all template
> parameters levels, this function returns a vector of vectors
> representing all the resulting argument levels. Note that in this
> @@ -9219,11 +9182,10 @@ coerce_template_parms (tree parms, tree args, tree in_decl,
>
> static tree
> coerce_innermost_template_parms (tree parms,
> - tree args,
> - tree in_decl,
> - tsubst_flags_t complain,
> - bool require_all_args,
> - bool use_default_args)
> + tree args,
> + tree in_decl,
> + tsubst_flags_t complain,
> + bool require_all_args /* = true */)
> {
> int parms_depth = TMPL_PARMS_DEPTH (parms);
> int args_depth = TMPL_ARGS_DEPTH (args);
> @@ -9243,8 +9205,7 @@ coerce_innermost_template_parms (tree parms,
> if (cur_depth == args_depth)
> l = coerce_template_parms (TREE_VALUE (level),
> args, in_decl, complain,
> - require_all_args,
> - use_default_args);
> + require_all_args);
> else
> l = TMPL_ARGS_LEVEL (args, cur_depth);
>
> @@ -9257,8 +9218,7 @@ coerce_innermost_template_parms (tree parms,
> else
> coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
> args, in_decl, complain,
> - require_all_args,
> - use_default_args);
> + require_all_args);
> return coerced_args;
> }
>
> @@ -9953,9 +9913,7 @@ lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
> actually tsubst'd into the definition to create the
> instantiation. */
> arglist = coerce_innermost_template_parms (parmlist, arglist, gen_tmpl,
> - complain,
> - /*require_all_args=*/true,
> - /*use_default_args=*/true);
> + complain);
>
> if (arglist == error_mark_node)
> /* We were unable to bind the arguments. */
> @@ -10371,9 +10329,7 @@ finish_template_variable (tree var, tsubst_flags_t complain)
> tree arglist = TREE_OPERAND (var, 1);
>
> tree parms = DECL_TEMPLATE_PARMS (templ);
> - arglist = coerce_innermost_template_parms (parms, arglist, templ, complain,
> - /*req_all*/true,
> - /*use_default*/true);
> + arglist = coerce_innermost_template_parms (parms, arglist, templ, complain);
> if (arglist == error_mark_node)
> return error_mark_node;
>
> @@ -15022,8 +14978,7 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
> the template. */
> argvec = (coerce_innermost_template_parms
> (DECL_TEMPLATE_PARMS (gen_tmpl),
> - argvec, t, complain,
> - /*all*/true, /*defarg*/true));
> + argvec, t, complain));
> if (argvec == error_mark_node)
> RETURN (error_mark_node);
> hash = spec_hasher::hash (gen_tmpl, argvec);
> @@ -21956,11 +21911,8 @@ instantiate_alias_template (tree tmpl, tree args, tsubst_flags_t complain)
> if (tmpl == error_mark_node || args == error_mark_node)
> return error_mark_node;
>
> - args =
> - coerce_innermost_template_parms (DECL_TEMPLATE_PARMS (tmpl),
> - args, tmpl, complain,
> - /*require_all_args=*/true,
> - /*use_default_args=*/true);
> + args = coerce_innermost_template_parms (DECL_TEMPLATE_PARMS (tmpl),
> + args, tmpl, complain);
>
> /* FIXME check for satisfaction in check_instantiated_args. */
> if (flag_concepts
> @@ -22210,8 +22162,7 @@ fn_type_unification (tree fn,
> explicit_targs
> = (coerce_template_parms (tparms, explicit_targs, fn,
> complain|tf_partial,
> - /*require_all_args=*/false,
> - /*use_default_args=*/false));
> + /*require_all_args=*/false));
> if (explicit_targs == error_mark_node)
> goto fail;
>
> @@ -23304,9 +23255,7 @@ resolve_overloaded_unification (tree tparms,
> continue;
>
> subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
> - expl_subargs, NULL_TREE, tf_none,
> - /*require_all_args=*/true,
> - /*use_default_args=*/true);
> + expl_subargs, NULL_TREE, tf_none);
> if (subargs != error_mark_node
> && !any_dependent_template_arguments_p (subargs))
> {
> @@ -23450,9 +23399,7 @@ resolve_nondeduced_context (tree orig_expr, tsubst_flags_t complain)
> continue;
>
> subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
> - expl_subargs, NULL_TREE, tf_none,
> - /*require_all_args=*/true,
> - /*use_default_args=*/true);
> + expl_subargs, NULL_TREE, tf_none);
> if (subargs != error_mark_node
> && !any_dependent_template_arguments_p (subargs))
> {
> @@ -25581,7 +25528,7 @@ get_partial_spec_bindings (tree tmpl, tree spec_tmpl, tree args)
> if (spec_args != error_mark_node)
> spec_args = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
> INNERMOST_TEMPLATE_ARGS (spec_args),
> - tmpl, tf_none, false, false);
> + tmpl, tf_none, false);
>
> pop_tinst_level ();
>
prev parent reply other threads:[~2022-10-24 19:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-24 16:27 Patrick Palka
2022-10-24 19:56 ` Jason Merrill [this message]
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