c++: remove coerce_innermost_template_parms
Commit Message
IIUC the only practical difference between coerce_innermost_template_parms
and the main function coerce_template_parms is that the former takes
a multi-level template parameter list and returns a template argument
vector of the same depth, whereas the latter takes a single-level
template parameter vector and returns a single-level template argument
vector.
This patch gets rid of the wrapper function and just overloads the
behavior of the main function according to whether 'parms' is a
multi-level template parameter list or a single-level template argument
vector. It turns out we can assume parms and args have the same depth
in the multi-level case, which simplifies the overloading logic.
Besides the (subjective) simplificatio benefit, another benefit of this
unification is that it avoids a redundant copy of a multi-level 'args'.
Now, we can return new_args directly from c_t_p. (And because of this,
we need to turn new_inner_args into a reference so that updating it also
updates new_args.)
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk?
gcc/cp/ChangeLog:
* pt.cc (coerce_template_parms): Salvage part of the function
comment from c_innermost_t_p. Handle parms being a full
template parameter list.
(coerce_innermost_template_parms): Remove.
(lookup_template_class): Use c_t_p instead of c_innermost_t_p.
(finish_template_variable): Likewise.
(tsubst_decl): Likewise.
(instantiate_alias_template): Likewise.
---
gcc/cp/pt.cc | 92 +++++++++++++++-------------------------------------
1 file changed, 27 insertions(+), 65 deletions(-)
Comments
On 11/18/22 16:59, Patrick Palka wrote:
> IIUC the only practical difference between coerce_innermost_template_parms
> and the main function coerce_template_parms is that the former takes
> a multi-level template parameter list and returns a template argument
> vector of the same depth, whereas the latter takes a single-level
> template parameter vector and returns a single-level template argument
> vector.
>
> This patch gets rid of the wrapper function and just overloads the
> behavior of the main function according to whether 'parms' is a
> multi-level template parameter list or a single-level template argument
> vector. It turns out we can assume parms and args have the same depth
> in the multi-level case, which simplifies the overloading logic.
>
> Besides the (subjective) simplificatio benefit, another benefit of this
> unification is that it avoids a redundant copy of a multi-level 'args'.
> Now, we can return new_args directly from c_t_p. (And because of this,
> we need to turn new_inner_args into a reference so that updating it also
> updates new_args.)
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> trunk?
OK. But this doesn't really seem like stage 3 material; let's hold off
on further cleanups like this until next stage 1.
> gcc/cp/ChangeLog:
>
> * pt.cc (coerce_template_parms): Salvage part of the function
> comment from c_innermost_t_p. Handle parms being a full
> template parameter list.
> (coerce_innermost_template_parms): Remove.
> (lookup_template_class): Use c_t_p instead of c_innermost_t_p.
> (finish_template_variable): Likewise.
> (tsubst_decl): Likewise.
> (instantiate_alias_template): Likewise.
> ---
> gcc/cp/pt.cc | 92 +++++++++++++++-------------------------------------
> 1 file changed, 27 insertions(+), 65 deletions(-)
>
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index 0310e38c9b9..2666e455edf 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -148,8 +148,6 @@ 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_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
> - 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,
> @@ -8827,6 +8825,14 @@ pack_expansion_args_count (tree args)
> arguments. If any error occurs, return error_mark_node. Error and
> warning messages are issued under control of COMPLAIN.
>
> + If PARMS represents all template parameters levels, this function
> + returns a vector of vectors representing all the resulting argument
> + levels. Note that in this case, only the innermost arguments are
> + coerced because the outermost ones are supposed to have been coerced
> + already. Otherwise, if PARMS represents only (the innermost) vector
> + of parameters, this function returns a vector containing just the
> + innermost resulting arguments.
> +
> If REQUIRE_ALL_ARGS is false, argument deduction will be performed
> for arguments not specified in ARGS. If REQUIRE_ALL_ARGS is true,
> arguments not specified in ARGS must have default arguments which
> @@ -8842,8 +8848,6 @@ coerce_template_parms (tree parms,
> int nparms, nargs, parm_idx, arg_idx, lost = 0;
> tree orig_inner_args;
> tree inner_args;
> - tree new_args;
> - tree new_inner_args;
>
> /* When used as a boolean value, indicates whether this is a
> variadic template parameter list. Since it's an int, we can also
> @@ -8864,6 +8868,17 @@ coerce_template_parms (tree parms,
> if (args == error_mark_node)
> return error_mark_node;
>
> + bool return_full_args = false;
> + if (TREE_CODE (parms) == TREE_LIST)
> + {
> + if (TMPL_PARMS_DEPTH (parms) > 1)
> + {
> + gcc_assert (TMPL_PARMS_DEPTH (parms) == TMPL_ARGS_DEPTH (args));
> + return_full_args = true;
> + }
> + parms = INNERMOST_TEMPLATE_PARMS (parms);
> + }
> +
> nparms = TREE_VEC_LENGTH (parms);
>
> /* Determine if there are any parameter packs or default arguments. */
> @@ -8961,8 +8976,8 @@ coerce_template_parms (tree parms,
> template-id may be nested within a "sizeof". */
> cp_evaluated ev;
>
> - new_inner_args = make_tree_vec (nparms);
> - new_args = add_outermost_template_args (args, new_inner_args);
> + tree new_args = add_outermost_template_args (args, make_tree_vec (nparms));
> + tree& new_inner_args = TMPL_ARGS_LEVEL (new_args, TMPL_ARGS_DEPTH (new_args));
> int pack_adjust = 0;
> for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
> {
> @@ -9164,59 +9179,7 @@ coerce_template_parms (tree parms,
> SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
> TREE_VEC_LENGTH (new_inner_args));
>
> - return new_inner_args;
> -}
> -
> -/* 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
> - case, only the innermost arguments are coerced because the
> - outermost ones are supposed to have been coerced already.
> -
> - Otherwise, if PARMS represents only (the innermost) vector of
> - parameters, this function returns a vector containing just the
> - innermost resulting arguments. */
> -
> -static tree
> -coerce_innermost_template_parms (tree parms,
> - 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);
> - tree coerced_args;
> -
> - if (parms_depth > 1)
> - {
> - coerced_args = make_tree_vec (parms_depth);
> - tree level;
> - int cur_depth;
> -
> - for (level = parms, cur_depth = parms_depth;
> - parms_depth > 0 && level != NULL_TREE;
> - level = TREE_CHAIN (level), --cur_depth)
> - {
> - tree l;
> - if (cur_depth == args_depth)
> - l = coerce_template_parms (TREE_VALUE (level),
> - args, in_decl, complain,
> - require_all_args);
> - else
> - l = TMPL_ARGS_LEVEL (args, cur_depth);
> -
> - if (l == error_mark_node)
> - return error_mark_node;
> -
> - SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l);
> - }
> - }
> - else
> - coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
> - args, in_decl, complain,
> - require_all_args);
> - return coerced_args;
> + return return_full_args ? new_args : new_inner_args;
> }
>
> /* Returns true if T is a wrapper to make a C++20 template parameter
> @@ -9909,8 +9872,7 @@ lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
> /* Calculate the BOUND_ARGS. These will be the args that are
> actually tsubst'd into the definition to create the
> instantiation. */
> - arglist = coerce_innermost_template_parms (parmlist, arglist, gen_tmpl,
> - complain);
> + arglist = coerce_template_parms (parmlist, arglist, gen_tmpl, complain);
>
> if (arglist == error_mark_node)
> /* We were unable to bind the arguments. */
> @@ -10326,7 +10288,7 @@ 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);
> + arglist = coerce_template_parms (parms, arglist, templ, complain);
> if (arglist == error_mark_node)
> return error_mark_node;
>
> @@ -14962,7 +14924,7 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
> /* We're fully specializing a template declaration, so
> we need to coerce the innermost arguments corresponding to
> the template. */
> - argvec = (coerce_innermost_template_parms
> + argvec = (coerce_template_parms
> (DECL_TEMPLATE_PARMS (gen_tmpl),
> argvec, t, complain));
> if (argvec == error_mark_node)
> @@ -21800,8 +21762,8 @@ 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);
> + args = coerce_template_parms (DECL_TEMPLATE_PARMS (tmpl),
> + args, tmpl, complain);
>
> /* FIXME check for satisfaction in check_instantiated_args. */
> if (flag_concepts
@@ -148,8 +148,6 @@ 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_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
- 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,
@@ -8827,6 +8825,14 @@ pack_expansion_args_count (tree args)
arguments. If any error occurs, return error_mark_node. Error and
warning messages are issued under control of COMPLAIN.
+ If PARMS represents all template parameters levels, this function
+ returns a vector of vectors representing all the resulting argument
+ levels. Note that in this case, only the innermost arguments are
+ coerced because the outermost ones are supposed to have been coerced
+ already. Otherwise, if PARMS represents only (the innermost) vector
+ of parameters, this function returns a vector containing just the
+ innermost resulting arguments.
+
If REQUIRE_ALL_ARGS is false, argument deduction will be performed
for arguments not specified in ARGS. If REQUIRE_ALL_ARGS is true,
arguments not specified in ARGS must have default arguments which
@@ -8842,8 +8848,6 @@ coerce_template_parms (tree parms,
int nparms, nargs, parm_idx, arg_idx, lost = 0;
tree orig_inner_args;
tree inner_args;
- tree new_args;
- tree new_inner_args;
/* When used as a boolean value, indicates whether this is a
variadic template parameter list. Since it's an int, we can also
@@ -8864,6 +8868,17 @@ coerce_template_parms (tree parms,
if (args == error_mark_node)
return error_mark_node;
+ bool return_full_args = false;
+ if (TREE_CODE (parms) == TREE_LIST)
+ {
+ if (TMPL_PARMS_DEPTH (parms) > 1)
+ {
+ gcc_assert (TMPL_PARMS_DEPTH (parms) == TMPL_ARGS_DEPTH (args));
+ return_full_args = true;
+ }
+ parms = INNERMOST_TEMPLATE_PARMS (parms);
+ }
+
nparms = TREE_VEC_LENGTH (parms);
/* Determine if there are any parameter packs or default arguments. */
@@ -8961,8 +8976,8 @@ coerce_template_parms (tree parms,
template-id may be nested within a "sizeof". */
cp_evaluated ev;
- new_inner_args = make_tree_vec (nparms);
- new_args = add_outermost_template_args (args, new_inner_args);
+ tree new_args = add_outermost_template_args (args, make_tree_vec (nparms));
+ tree& new_inner_args = TMPL_ARGS_LEVEL (new_args, TMPL_ARGS_DEPTH (new_args));
int pack_adjust = 0;
for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
{
@@ -9164,59 +9179,7 @@ coerce_template_parms (tree parms,
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
TREE_VEC_LENGTH (new_inner_args));
- return new_inner_args;
-}
-
-/* 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
- case, only the innermost arguments are coerced because the
- outermost ones are supposed to have been coerced already.
-
- Otherwise, if PARMS represents only (the innermost) vector of
- parameters, this function returns a vector containing just the
- innermost resulting arguments. */
-
-static tree
-coerce_innermost_template_parms (tree parms,
- 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);
- tree coerced_args;
-
- if (parms_depth > 1)
- {
- coerced_args = make_tree_vec (parms_depth);
- tree level;
- int cur_depth;
-
- for (level = parms, cur_depth = parms_depth;
- parms_depth > 0 && level != NULL_TREE;
- level = TREE_CHAIN (level), --cur_depth)
- {
- tree l;
- if (cur_depth == args_depth)
- l = coerce_template_parms (TREE_VALUE (level),
- args, in_decl, complain,
- require_all_args);
- else
- l = TMPL_ARGS_LEVEL (args, cur_depth);
-
- if (l == error_mark_node)
- return error_mark_node;
-
- SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l);
- }
- }
- else
- coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
- args, in_decl, complain,
- require_all_args);
- return coerced_args;
+ return return_full_args ? new_args : new_inner_args;
}
/* Returns true if T is a wrapper to make a C++20 template parameter
@@ -9909,8 +9872,7 @@ lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
/* Calculate the BOUND_ARGS. These will be the args that are
actually tsubst'd into the definition to create the
instantiation. */
- arglist = coerce_innermost_template_parms (parmlist, arglist, gen_tmpl,
- complain);
+ arglist = coerce_template_parms (parmlist, arglist, gen_tmpl, complain);
if (arglist == error_mark_node)
/* We were unable to bind the arguments. */
@@ -10326,7 +10288,7 @@ 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);
+ arglist = coerce_template_parms (parms, arglist, templ, complain);
if (arglist == error_mark_node)
return error_mark_node;
@@ -14962,7 +14924,7 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
/* We're fully specializing a template declaration, so
we need to coerce the innermost arguments corresponding to
the template. */
- argvec = (coerce_innermost_template_parms
+ argvec = (coerce_template_parms
(DECL_TEMPLATE_PARMS (gen_tmpl),
argvec, t, complain));
if (argvec == error_mark_node)
@@ -21800,8 +21762,8 @@ 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);
+ args = coerce_template_parms (DECL_TEMPLATE_PARMS (tmpl),
+ args, tmpl, complain);
/* FIXME check for satisfaction in check_instantiated_args. */
if (flag_concepts