On Fri, Aug 25, 2023 at 12:33:31PM -0400, Patrick Palka via Gcc-patches wrote:
> Boostrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
> trunk?
Very nice. LGTM.
> -- >8 --
>
> This replaces manual memory management via conversion_obstack_alloc(0)
> and obstack_free with the recently added conversion_obstack_sentinel,
> and also uses the latter in build_user_type_conversion and
> build_operator_new_call.
>
> gcc/cp/ChangeLog:
>
> * call.cc (build_user_type_conversion): Free allocated
> conversions.
> (build_converted_constant_expr_internal): Use
> conversion_obstack_sentinel instead.
> (perform_dguide_overload_resolution): Likewise.
> (build_new_function_call): Likewise.
> (build_operator_new_call): Free allocated conversions.
> (build_op_call): Use conversion_obstack_sentinel instead.
> (build_conditional_expr): Use conversion_obstack_sentinel
> instead, and hoist it out to the outermost scope.
> (build_new_op): Use conversion_obstack_sentinel instead
> and set it up before the first goto. Remove second unneeded goto.
> (build_op_subscript): Use conversion_obstack_sentinel instead.
> (ref_conv_binds_to_temporary): Likewise.
> (build_new_method_call): Likewise.
> (can_convert_arg): Likewise.
> (can_convert_arg_bad): Likewise.
> (perform_implicit_conversion_flags): Likewise.
> (perform_direct_initialization_if_possible): Likewise.
> (initialize_reference): Likewise.
> ---
> gcc/cp/call.cc | 107 ++++++++++---------------------------------------
> 1 file changed, 22 insertions(+), 85 deletions(-)
>
> diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
> index 673ec91d60e..432ac99b4bb 100644
> --- a/gcc/cp/call.cc
> +++ b/gcc/cp/call.cc
> @@ -4646,6 +4646,9 @@ build_user_type_conversion (tree totype, tree expr, int
> flags,
> tree ret;
>
> auto_cond_timevar tv (TV_OVERLOAD);
> +
> + conversion_obstack_sentinel cos;
> +
> cand = build_user_type_conversion_1 (totype, expr, flags, complain);
>
> if (cand)
> @@ -4698,15 +4701,13 @@ build_converted_constant_expr_internal (tree type,
> tree expr,
> int flags, tsubst_flags_t complain)
> {
> conversion *conv;
> - void *p;
> tree t;
> location_t loc = cp_expr_loc_or_input_loc (expr);
>
> if (error_operand_p (expr))
> return error_mark_node;
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> conv = implicit_conversion (type, TREE_TYPE (expr), expr,
> /*c_cast_p=*/false, flags, complain);
> @@ -4815,9 +4816,6 @@ build_converted_constant_expr_internal (tree type, tree
> expr,
> expr = error_mark_node;
> }
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return expr;
> }
>
> @@ -4985,8 +4983,7 @@ perform_dguide_overload_resolution (tree dguides, const
> vec<tree, va_gc> *args,
>
> gcc_assert (deduction_guide_p (OVL_FIRST (dguides)));
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - void *p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> z_candidate *cand = perform_overload_resolution (dguides, args,
> &candidates,
> &any_viable_p, complain);
> @@ -4999,9 +4996,6 @@ perform_dguide_overload_resolution (tree dguides, const
> vec<tree, va_gc> *args,
> else
> result = cand->fn;
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return result;
> }
>
> @@ -5015,7 +5009,6 @@ build_new_function_call (tree fn, vec<tree, va_gc>
> **args,
> {
> struct z_candidate *candidates, *cand;
> bool any_viable_p;
> - void *p;
> tree result;
>
> if (args != NULL && *args != NULL)
> @@ -5028,8 +5021,7 @@ build_new_function_call (tree fn, vec<tree, va_gc>
> **args,
> if (flag_tm)
> tm_malloc_replacement (fn);
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p,
> complain);
> @@ -5061,9 +5053,6 @@ build_new_function_call (tree fn, vec<tree, va_gc>
> **args,
> == BUILT_IN_NORMAL)
> result = coro_validate_builtin_call (result);
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return result;
> }
>
> @@ -5108,6 +5097,8 @@ build_operator_new_call (tree fnname, vec<tree, va_gc>
> **args,
> if (*args == NULL)
> return error_mark_node;
>
> + conversion_obstack_sentinel cos;
> +
> /* Based on:
>
> [expr.new]
> @@ -5234,7 +5225,6 @@ build_op_call (tree obj, vec<tree, va_gc> **args,
> tsubst_flags_t complain)
> tree fns, convs, first_mem_arg = NULL_TREE;
> bool any_viable_p;
> tree result = NULL_TREE;
> - void *p;
>
> auto_cond_timevar tv (TV_OVERLOAD);
>
> @@ -5273,8 +5263,7 @@ build_op_call (tree obj, vec<tree, va_gc> **args,
> tsubst_flags_t complain)
> return error_mark_node;
> }
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> if (fns)
> {
> @@ -5377,9 +5366,6 @@ build_op_call (tree obj, vec<tree, va_gc> **args,
> tsubst_flags_t complain)
> }
> }
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return result;
> }
>
> @@ -5587,7 +5573,6 @@ build_conditional_expr (const op_location_t &loc,
> bool is_glvalue = true;
> struct z_candidate *candidates = 0;
> struct z_candidate *cand;
> - void *p;
> tree orig_arg2, orig_arg3;
>
> auto_cond_timevar tv (TV_OVERLOAD);
> @@ -5631,6 +5616,8 @@ build_conditional_expr (const op_location_t &loc,
> || error_operand_p (arg3))
> return error_mark_node;
>
> + conversion_obstack_sentinel cos;
> +
> orig_arg2 = arg2;
> orig_arg3 = arg3;
>
> @@ -5911,9 +5898,6 @@ build_conditional_expr (const op_location_t &loc,
> conversion *conv3;
> bool converted = false;
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> -
> conv2 = conditional_conversion (arg2, arg3, complain);
> conv3 = conditional_conversion (arg3, arg2, complain);
>
> @@ -5969,9 +5953,6 @@ build_conditional_expr (const op_location_t &loc,
> converted = true;
> }
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> if (result)
> return result;
>
> @@ -6961,7 +6942,6 @@ build_new_op (const op_location_t &loc, enum tree_code
> code, int flags,
> enum tree_code code2 = ERROR_MARK;
> enum tree_code code_orig_arg1 = ERROR_MARK;
> enum tree_code code_orig_arg2 = ERROR_MARK;
> - void *p;
> bool strict_p;
> bool any_viable_p;
>
> @@ -6972,6 +6952,8 @@ build_new_op (const op_location_t &loc, enum tree_code
> code, int flags,
> || error_operand_p (arg3))
> return error_mark_node;
>
> + conversion_obstack_sentinel cos;
> +
> bool ismodop = code == MODIFY_EXPR;
> if (ismodop)
> {
> @@ -7042,13 +7024,10 @@ build_new_op (const op_location_t &loc, enum
> tree_code code, int flags,
> if (arg3 != NULL_TREE)
> arglist->quick_push (arg3);
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> -
> result = add_operator_candidates (&candidates, code, code2, arglist,
> lookups, flags, complain);
> if (result == error_mark_node)
> - goto user_defined_result_ready;
> + return error_mark_node;
>
> switch (code)
> {
> @@ -7343,11 +7322,6 @@ build_new_op (const op_location_t &loc, enum tree_code
> code, int flags,
> }
> }
>
> - user_defined_result_ready:
> -
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> if (result || result_valid_p)
> return result;
>
> @@ -7443,7 +7417,6 @@ build_op_subscript (const op_location_t &loc, tree obj,
> tree fns, first_mem_arg = NULL_TREE;
> bool any_viable_p;
> tree result = NULL_TREE;
> - void *p;
>
> auto_cond_timevar tv (TV_OVERLOAD);
>
> @@ -7473,8 +7446,7 @@ build_op_subscript (const op_location_t &loc, tree obj,
> return error_mark_node;
> }
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> if (fns)
> {
> @@ -7542,9 +7514,6 @@ build_op_subscript (const op_location_t &loc, tree obj,
> gcc_unreachable ();
> }
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return result;
> }
>
> @@ -9687,8 +9656,7 @@ ref_conv_binds_to_temporary (tree type, tree expr, bool
> direct_init_p/*=false*/)
> {
> gcc_assert (TYPE_REF_P (type));
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - void *p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> const int flags = direct_init_p ? LOOKUP_NORMAL : LOOKUP_IMPLICIT;
> conversion *conv = implicit_conversion (type, TREE_TYPE (expr), expr,
> @@ -9697,9 +9665,6 @@ ref_conv_binds_to_temporary (tree type, tree expr, bool
> direct_init_p/*=false*/)
> if (conv && !conv->bad_p)
> ret = tristate (conv_binds_ref_to_temporary (conv));
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return ret;
> }
>
> @@ -11423,7 +11388,6 @@ build_new_method_call (tree instance, tree fns,
> vec<tree, va_gc> **args,
> tree orig_instance;
> tree orig_fns;
> vec<tree, va_gc> *orig_args = NULL;
> - void *p;
>
> auto_cond_timevar tv (TV_OVERLOAD);
>
> @@ -11550,8 +11514,7 @@ build_new_method_call (tree instance, tree fns,
> vec<tree, va_gc> **args,
> else
> first_mem_arg = maybe_resolve_dummy (instance, false);
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> /* The number of arguments artificial parms in ARGS; we subtract one
> because
> there's no 'this' in ARGS. */
> @@ -11816,9 +11779,6 @@ skip_prune:
> call = build_nop (void_type_node, call);
> }
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> if (orig_args != NULL)
> release_tree_vector (orig_args);
>
> @@ -13335,11 +13295,9 @@ can_convert_arg (tree to, tree from, tree arg, int
> flags,
> tsubst_flags_t complain)
> {
> conversion *t;
> - void *p;
> bool ok_p;
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
> /* We want to discard any access checks done for this test,
> as we might not be in the appropriate access context and
> we'll do the check again when we actually perform the
> @@ -13352,8 +13310,6 @@ can_convert_arg (tree to, tree from, tree arg, int
> flags,
>
> /* Discard the access checks now. */
> pop_deferring_access_checks ();
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
>
> return ok_p;
> }
> @@ -13365,15 +13321,11 @@ can_convert_arg_bad (tree to, tree from, tree arg,
> int flags,
> tsubst_flags_t complain)
> {
> conversion *t;
> - void *p;
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
> /* Try to perform the conversion. */
> t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
> flags, complain);
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
>
> return t != NULL;
> }
> @@ -13408,7 +13360,6 @@ perform_implicit_conversion_flags (tree type, tree
> expr,
> tsubst_flags_t complain, int flags)
> {
> conversion *conv;
> - void *p;
> location_t loc = cp_expr_loc_or_input_loc (expr);
>
> if (TYPE_REF_P (type))
> @@ -13419,8 +13370,7 @@ perform_implicit_conversion_flags (tree type, tree
> expr,
> if (error_operand_p (expr))
> return error_mark_node;
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> conv = implicit_conversion (type, TREE_TYPE (expr), expr,
> /*c_cast_p=*/false,
> @@ -13441,9 +13391,6 @@ perform_implicit_conversion_flags (tree type, tree
> expr,
> expr = convert_like (conv, expr, complain);
> }
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return expr;
> }
>
> @@ -13469,7 +13416,6 @@ perform_direct_initialization_if_possible (tree type,
> tsubst_flags_t complain)
> {
> conversion *conv;
> - void *p;
>
> if (type == error_mark_node || error_operand_p (expr))
> return error_mark_node;
> @@ -13496,8 +13442,7 @@ perform_direct_initialization_if_possible (tree type,
> return build_cplus_new (type, expr, complain);
> }
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> conv = implicit_conversion (type, TREE_TYPE (expr), expr,
> c_cast_p,
> @@ -13519,9 +13464,6 @@ perform_direct_initialization_if_possible (tree type,
> /*issue_conversion_warnings=*/false,
> c_cast_p, /*nested_p=*/false, complain);
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return expr;
> }
>
> @@ -13760,14 +13702,12 @@ initialize_reference (tree type, tree expr,
> int flags, tsubst_flags_t complain)
> {
> conversion *conv;
> - void *p;
> location_t loc = cp_expr_loc_or_input_loc (expr);
>
> if (type == error_mark_node || error_operand_p (expr))
> return error_mark_node;
>
> - /* Get the high-water mark for the CONVERSION_OBSTACK. */
> - p = conversion_obstack_alloc (0);
> + conversion_obstack_sentinel cos;
>
> conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
> flags, complain);
> @@ -13814,9 +13754,6 @@ initialize_reference (tree type, tree expr,
> else
> gcc_unreachable ();
>
> - /* Free all the conversions we allocated. */
> - obstack_free (&conversion_obstack, p);
> -
> return expr;
> }
>
> --
> 2.42.0.29.gcd9da15a85
>
Marek
