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742910838e
First, we should avoid code such as
gl_list_iterator_t it = gl_list_iterator (deriv->children);
derivation *child = NULL;
while (gl_list_iterator_next (&it, (const void **) &child, NULL))
{
derivation_print (child, f);
because of -Wstrict-aliasing (whose job is to catch type-punning
issues). See https://lists.gnu.org/r/bug-bison/2020-05/msg00039.html.
Rather we need
gl_list_iterator_t it = gl_list_iterator (deriv->children);
const void **p = NULL;
while (gl_list_iterator_next (&it, &p, NULL))
{
derivation *child = (derivation *) p;
derivation_print (child, f);
Second, list iterators actually have destructors. Even though they
are noop in the case of linked-lists, we should use them.
Let's address both issues with typed wrappers (such as
derivation_list_next) that take care of both issues, and besides allow
to scope the iterators within the loop:
derivation *child;
for (gl_list_iterator_t it = gl_list_iterator (deriv->children);
derivation_list_next (&it, &child);
)
{
derivation_print (child, f);
* src/derivation.h, src/derivation.c (derivation_list_next): New.
Use it where appropriate.
* src/counterexample.c (search_state_list_next): New.
Use it where appropriate.
* src/parse-simulation.h, src/parse-simulation.c
* src/state-item.h (state_item_list_next): New.
Use it where appropriate.
109 lines
3.4 KiB
C
109 lines
3.4 KiB
C
/* Counterexample Generation Search Nodes
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Copyright (C) 2020 Free Software Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef STATE_ITEM_H
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# define STATE_ITEM_H
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# include <bitsetv.h>
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# include <gl_list.h>
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# include <hash.h>
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# include "gram.h"
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# include "state.h"
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/* Initializes a graph connecting (state, production item) pairs to
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pairs they can make a transition or production step to. This graph
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is used to search for paths that represent counterexamples of some
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conflict.
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state_items is an array of state state-item pairs ordered by state.
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state_item_map maps state numbers to the first item which
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corresponds to it in the array. A state's portion in state_items
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begins with its items in the same order as it was in the
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state. This is then followed by productions from the closure of the
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state in order by rule.
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There are two type of edges in this graph transitions and
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productions. Transitions are the same as transitions from the
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parser except edges are only between items from the same
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rule.
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Productions are edges from items with a nonterminal after the dot to
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the production of that nonterminal in the same state. These edges are
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stored as a bitset in a state-item.
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The inverses of these edges are stored in a bitset in the state-item,
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"revs." A state-item that begins with a dot will have reverse
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production edges, and all others will have reverse transition
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edges. */
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# define SI_DISABLED(sin) (state_items[sin].trans == -2)
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# define SI_PRODUCTION(si) ((si) == state_items || *((si)->item - 1) < 0)
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# define SI_TRANSITION(si) ((si) != state_items && *((si)->item - 1) >= 0)
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typedef int state_item_number;
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typedef struct
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{
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const state *state;
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item_number *item;
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state_item_number trans;
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bitset prods;
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bitset revs;
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bitset lookahead;
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} state_item;
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extern bitsetv firsts;
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# define FIRSTS(sym) firsts[(sym) - ntokens]
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extern size_t nstate_items;
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extern state_item_number *state_item_map;
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/** Array mapping state_item_numbers to state_items */
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extern state_item *state_items;
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state_item *state_item_lookup (state_number s, state_item_number off);
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static inline state_item_number
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state_item_index_lookup (state_number s, state_item_number off)
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{
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return state_item_map[s] + off;
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}
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void state_items_init (void);
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void print_state_item (const state_item *si, FILE *out);
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void state_items_free (void);
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bool production_allowed (const state_item *si, const state_item *next);
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static inline bool
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state_item_list_next (gl_list_iterator_t *it, state_item **si)
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{
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const void *p = NULL;
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bool res = gl_list_iterator_next (it, &p, NULL);
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if (res)
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*si = (state_item *) p;
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else
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gl_list_iterator_free (it);
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return res;
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}
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#endif /* STATE_ITEM_H */
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