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cex: derivation reference counting

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* src/derivation.h, src/derivation.c: Make derivation struct opaque.
Add derivation_list type for clarity.
(derivation_list_new): New.
(derivation_list_append): New.
(derivation_list_prepend): New.
(derivation_new_leaf): New constructor for derivations with no
children.
* src/counterexample.c, src/parse-simulation.c,
* src/parse-simulation.h: Replace uses of gl_list_t containing
derivations with derivation_list and its API.
Replace calls of dervation_new using null children with
derivation_new_leaf.
* src/parse-simulation.c: replace ps_chunk and its API with typed
versions si_chunk and deriv_chunk.
* src/parse-simlation.h, src/parse-simulation.c: Remove
parse_state_retain_deriv in favor of derivation reference counting.
* src/counterexample.c: Remove search_state_retain_deriv.
This commit is contained in:
Vincent Imbimbo
2020-05-21 22:13:11 -04:00
committed by Akim Demaille
parent fc39ccab6b
commit 35c4a8e65e
5 changed files with 224 additions and 140 deletions
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95
src/counterexample.c
View File

@@ -169,7 +169,7 @@ si_bfs_free (si_bfs_node *n)
*
* this returns the derivation of the productions that lead to conflict_sym
*/
static inline gl_list_t
static inline derivation_list
expand_to_conflict (state_item_number start, symbol_number conflict_sym)
{
si_bfs_node *init = si_bfs_new (start, NULL);
@@ -216,11 +216,9 @@ expand_to_conflict (state_item_number start, symbol_number conflict_sym)
exit (1);
}
derivation *dinit = derivation_new (conflict_sym, NULL);
gl_list_t result =
gl_list_create (GL_LINKED_LIST, NULL, NULL,
(gl_listelement_dispose_fn) derivation_free,
true, 1, (const void **) &dinit);
derivation *dinit = derivation_new_leaf (conflict_sym);
derivation_list result = derivation_list_new ();
derivation_list_append (result, dinit);
// iterate backwards through the generated path to create a derivation
// of the conflict symbol containing derivations of each production step.
@@ -232,23 +230,22 @@ expand_to_conflict (state_item_number start, symbol_number conflict_sym)
{
item_number *i = NULL;
for (i = pos + 1; !item_number_is_rule_number (*i); ++i)
gl_list_add_last (result, derivation_new (*i, NULL));
derivation_list_append (result, derivation_new_leaf (*i));
symbol_number lhs =
rules[item_number_as_rule_number (*i)].lhs->number;
derivation *deriv = derivation_new (lhs, result);
result =
gl_list_create (GL_LINKED_LIST, NULL, NULL,
(gl_listelement_dispose_fn) derivation_free,
true, 1, (const void **) &deriv);
result = derivation_list_new ();
derivation_list_append (result, deriv);
}
else
{
symbol_number sym = item_number_as_symbol_number (*(pos - 1));
derivation *deriv = derivation_new (sym, NULL);
gl_list_add_first (result, deriv);
derivation *deriv = derivation_new_leaf (sym);
derivation_list_prepend (result, deriv);
}
}
gl_list_free (queue);
derivation_free ((derivation*)gl_list_get_at (result, 0));
gl_list_remove_at (result, 0);
return result;
}
@@ -263,16 +260,15 @@ expand_to_conflict (state_item_number start, symbol_number conflict_sym)
*/
static derivation *
complete_diverging_example (symbol_number conflict_sym,
gl_list_t path, gl_list_t derivs)
gl_list_t path, derivation_list derivs)
{
// The idea is to transfer each pending symbol on the productions
// associated with the given StateItems to the resulting derivation.
gl_list_t result =
gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
derivation_list result = derivation_list_new ();
bool lookahead_required = false;
if (!derivs)
{
derivs = gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
derivs = derivation_list_new ();
gl_list_add_last (result, derivation_dot ());
lookahead_required = true;
}
@@ -295,9 +291,8 @@ complete_diverging_example (symbol_number conflict_sym,
if (gl_list_size (result) == 1 && !item_number_is_rule_number (pos)
&& gl_list_get_at (result, 0) == derivation_dot() )
{
gl_list_add_last (result,
derivation_new (item_number_as_symbol_number
(pos), NULL));
derivation_list_append (result,
derivation_new_leaf (item_number_as_symbol_number (pos)));
lookahead_required = false;
}
item_number *i = item;
@@ -313,7 +308,7 @@ complete_diverging_example (symbol_number conflict_sym,
symbol_number sym = item_number_as_symbol_number (*i);
if (!lookahead_required || sym == conflict_sym)
{
gl_list_add_last (result, derivation_new (sym, NULL));
derivation_list_append (result, derivation_new_leaf (sym));
lookahead_required = false;
continue;
}
@@ -330,25 +325,19 @@ complete_diverging_example (symbol_number conflict_sym,
if (bitset_test (FIRSTS (sym), conflict_sym))
{
lookahead_required = false;
gl_list_t next_derivs = expand_to_conflict (nsi,
conflict_sym);
derivation_list next_derivs =
expand_to_conflict (nsi, conflict_sym);
gl_list_iterator_t it = gl_list_iterator (next_derivs);
derivation *d = NULL;
while (gl_list_iterator_next (&it, (const void **) &d, NULL))
gl_list_add_last (result, d);
derivation_list_append (result, d);
i += gl_list_size (next_derivs) - 1;
// next_derivs is leaked to prevent the copied derivations from
// being freed. It is somewhat difficult to for expand_to_conflict
// to decide which derivation list will be the final one that is
// returned, so each list frees its derivations when freed.
derivation_list_free (next_derivs);
}
else if (nullable[sym - ntokens])
{
derivation *d = derivation_new (sym,
gl_list_create_empty
(GL_LINKED_LIST, NULL,
NULL, NULL, 1));
gl_list_add_last (result, d);
derivation *d = derivation_new_leaf (sym);
derivation_list_append (result, d);
}
else
{
@@ -356,7 +345,7 @@ complete_diverging_example (symbol_number conflict_sym,
// having the conflict symbol in its lookahead, no example
// containing the symbol after the conflict item
// can be found.
gl_list_add_last (result, derivation_new (1, NULL));
derivation_list_append (result, derivation_new_leaf (1));
lookahead_required = false;
}
}
@@ -371,19 +360,20 @@ complete_diverging_example (symbol_number conflict_sym,
{
const void *tmp_deriv = gl_list_node_value (derivs, deriv);
deriv = gl_list_previous_node (derivs, deriv);
gl_list_add_first (result, tmp_deriv);
derivation_list_prepend (result, (derivation*)tmp_deriv);
}
else
gl_list_add_first (result, derivation_new (*i, NULL));
derivation_list_prepend (result, derivation_new_leaf (*i));
}
// completing the derivation
derivation *new_deriv = derivation_new (rules[r].lhs->number, result);
result =
gl_list_create (GL_LINKED_LIST, NULL, NULL, NULL, true, 1,
(const void **) &new_deriv);
result = derivation_list_new ();
derivation_list_append (result, new_deriv);
}
derivation *res = (derivation *) gl_list_get_at (result, 0);
gl_list_free (result);
derivation_retain (res);
derivation_list_free (result);
derivation_list_free (derivs);
return res;
}
@@ -567,13 +557,6 @@ search_state_free (search_state *ss)
free (ss);
}
static inline void
search_state_retain_derivs (search_state *ss)
{
parse_state_retain_deriv (ss->states[0]);
parse_state_retain_deriv (ss->states[1]);
}
static void
search_state_print (search_state *ss)
{
@@ -608,9 +591,11 @@ complete_diverging_examples(search_state *ss,
derivation *new_derivs[2];
for (int i = 0; i < 2; ++i)
{
gl_list_t sitems, derivs;
gl_list_t sitems;
derivation_list derivs;
parse_state_lists (ss->states[i], &sitems, &derivs);
new_derivs[i] = complete_diverging_example (next_sym, sitems, derivs);
gl_list_free (sitems);
}
return new_counterexample (new_derivs[0], new_derivs[1], false, true);
}
@@ -778,6 +763,8 @@ reduction_step (search_state *ss, const item_number *conflict_item,
gl_list_add_last (result, copy);
}
gl_list_free (reduced);
if (symbol_set != si->lookahead)
bitset_free (symbol_set);
return result;
}
@@ -1068,17 +1055,16 @@ unifying_example (state_item_number itm1,
&& has_common_prefix (si1src->item, si2src->item))
{
// Stage 4: both paths share a prefix
const derivation *d1 = parse_state_derivation (ps1);
const derivation *d2 = parse_state_derivation (ps2);
derivation *d1 = parse_state_derivation (ps1);
derivation *d2 = parse_state_derivation (ps2);
if (parse_state_derivation_completed (ps1)
&& parse_state_derivation_completed (ps2)
&& d1->sym == d2->sym)
&& parse_state_derivation_completed (ps2))
{
// Once we have two derivations for the same symbol,
// we've found a unifying counterexample.
cex = new_counterexample (d1, d2, true, false);
// prevent d1/d2 from being freed.
search_state_retain_derivs (ss);
derivation_retain (d1);
derivation_retain (d2);
goto cex_search_end;
}
if (!stage3result)
@@ -1116,7 +1102,6 @@ cex_search_end:;
if (stage3result)
{
cex = complete_diverging_examples (stage3result, next_sym);
search_state_retain_derivs (stage3result);
search_state_free (stage3result);
}
// Otherwise, construct a nonunifying counterexample that

71
src/derivation.c
View File

@@ -18,37 +18,94 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include <gl_linked_list.h>
#include "system.h"
#include "derivation.h"
static derivation d_dot = { -1, NULL };
struct derivation
{
symbol_number sym;
gl_list_t children;
int reference_count;
};
const derivation *
static derivation d_dot = { -1, NULL, -1 };
derivation *
derivation_dot (void)
{
return &d_dot;
}
void
derivation_list_append (derivation_list dl, derivation *d)
{
derivation_retain (d);
gl_list_add_last (dl, d);
}
void
derivation_list_prepend (derivation_list dl, derivation *d)
{
derivation_retain (d);
gl_list_add_first (dl, d);
}
void derivation_list_free (derivation_list dl)
{
gl_list_iterator_t it = gl_list_iterator (dl);
derivation *d;
while (gl_list_iterator_next (&it, (const void **) &d, NULL))
if (d != &d_dot)
derivation_free (d);
gl_list_free (dl);
}
derivation *
derivation_new (symbol_number sym, gl_list_t children)
derivation_new (symbol_number sym, derivation_list children)
{
derivation *deriv = xmalloc (sizeof (derivation));
deriv->sym = sym;
deriv->children = children;
deriv->reference_count = 0;
return deriv;
}
void
derivation_retain (derivation *d)
{
++d->reference_count;
}
void
derivation_free (derivation *d)
{
if (d && d != &d_dot)
if (!d)
return;
derivation_list free_queue =
gl_list_create (GL_LINKED_LIST, NULL, NULL, NULL, true,
1, (const void **)&d);
while (gl_list_size (free_queue) > 0)
{
if (d->children)
gl_list_free (d->children);
free (d);
derivation *deriv = (derivation *) gl_list_get_at (free_queue, 0);
if (--deriv->reference_count == 0)
{
if (deriv->children)
{
gl_list_iterator_t it = gl_list_iterator (deriv->children);
derivation *child;
while (gl_list_iterator_next (&it, (const void **) &child, NULL))
if (child != &d_dot)
gl_list_add_last (free_queue, child);
gl_list_free (deriv->children);
}
free (deriv);
}
gl_list_remove_at (free_queue, 0);
}
gl_list_free (free_queue);
}
size_t

28
src/derivation.h
View File

@@ -20,7 +20,7 @@
#ifndef DERIVATION_H
# define DERIVATION_H
# include <gl_list.h>
# include <gl_xlist.h>
# include "gram.h"
@@ -29,18 +29,30 @@
relevant to the counterexample. The leaves of a derivation form a
counterexample when printed. */
typedef struct derivation
{
symbol_number sym;
gl_list_t children;
} derivation;
typedef gl_list_t derivation_list;
typedef struct derivation derivation;
derivation *derivation_new (symbol_number sym, gl_list_t children);
static inline derivation_list derivation_list_new (void)
{
return gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
}
void derivation_list_append (derivation_list dl, derivation *d);
void derivation_list_prepend (derivation_list dl, derivation *d);
void derivation_list_free (derivation_list dl);
derivation *derivation_new (symbol_number sym, derivation_list children);
static inline derivation *derivation_new_leaf (symbol_number sym)
{
return derivation_new (sym, NULL);
}
size_t derivation_size (const derivation *deriv);
void derivation_print (const derivation *deriv, FILE *f);
void derivation_print_leaves (const derivation *deriv, FILE *f);
void derivation_free (derivation *deriv);
void derivation_retain (derivation *deriv);
const derivation *derivation_dot (void);
derivation *derivation_dot (void);
#endif /* DERIVATION_H */

165
src/parse-simulation.c
View File

@@ -27,22 +27,26 @@
#include "nullable.h"
#include "parse-simulation.h"
typedef struct
{
// elements newly added in this chunk
gl_list_t contents;
// properties of the linked list this chunk represents
const void *head_elt;
const void *tail_elt;
size_t total_size;
} ps_chunk;
typedef struct parse_state
{
// path of state-items the parser has traversed
ps_chunk state_items;
struct si_chunk
{
// elements newly added in this chunk
gl_list_t contents;
// properties of the linked list this chunk represents
const state_item *head_elt;
const state_item *tail_elt;
size_t total_size;
} state_items;
// list of derivations of the symbols
ps_chunk derivs;
struct deriv_chunk
{
derivation_list contents;
const derivation *head_elt;
const derivation *tail_elt;
size_t total_size;
} derivs;
struct parse_state *parent;
int reference_count;
// incremented during productions,
@@ -60,23 +64,47 @@ typedef struct parse_state
static void
ps_chunk_prepend (ps_chunk *chunk, const void *element)
ps_si_prepend (parse_state *ps, const state_item *si)
{
gl_list_add_first (chunk->contents, element);
chunk->head_elt = element;
++chunk->total_size;
if (!chunk->tail_elt)
chunk->tail_elt = element;
struct si_chunk *sic = &ps->state_items;
gl_list_add_first (sic->contents, si);
sic->head_elt = si;
++sic->total_size;
if (!sic->tail_elt)
sic->tail_elt = si;
}
static void
ps_chunk_append (ps_chunk *chunk, const void *element)
ps_si_append (parse_state *ps, const state_item *si)
{
gl_list_add_last (chunk->contents, element);
chunk->tail_elt = element;
++chunk->total_size;
if (!chunk->head_elt)
chunk->head_elt = element;
struct si_chunk *sic = &ps->state_items;
gl_list_add_last (sic->contents, si);
sic->tail_elt = si;
++sic->total_size;
if (!sic->head_elt)
sic->head_elt = si;
}
static void
ps_derivs_prepend (parse_state *ps, derivation *d)
{
struct deriv_chunk *dc = &ps->derivs;
derivation_list_prepend (dc->contents, d);
dc->head_elt = d;
++dc->total_size;
if (!dc->tail_elt)
dc->tail_elt = d;
}
static void
ps_derivs_append (parse_state *ps, derivation *d)
{
struct deriv_chunk *dc = &ps->derivs;
derivation_list_append (dc->contents, d);
dc->tail_elt = d;
++dc->total_size;
if (!dc->head_elt)
dc->head_elt = d;
}
static int allocs = 0;
@@ -88,8 +116,7 @@ empty_parse_state (void)
parse_state *res = xcalloc (1, sizeof *res);
res->state_items.contents
= gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
res->derivs.contents
= gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
res->derivs.contents = derivation_list_new ();
++allocs;
return res;
}
@@ -98,8 +125,8 @@ parse_state *
new_parse_state (const state_item *si)
{
parse_state *res = empty_parse_state ();
ps_chunk_append (&res->state_items, si);
ps_chunk_append (&res->derivs, derivation_dot ());
ps_si_append (res, si);
ps_derivs_append (res, derivation_dot ());
return res;
}
@@ -110,8 +137,7 @@ copy_parse_state (bool prepend, parse_state *parent)
memcpy (res, parent, sizeof *res);
res->state_items.contents
= gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
res->derivs.contents
= gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
res->derivs.contents = derivation_list_new ();
res->parent = parent;
res->prepend = prepend;
res->reference_count = 0;
@@ -127,10 +153,10 @@ parse_state_derivation_completed (const parse_state *ps)
return ps->derivs.total_size == 1;
}
const derivation *
derivation *
parse_state_derivation (const parse_state *ps)
{
return ps->derivs.head_elt;
return (derivation *)ps->derivs.head_elt;
}
const state_item *
@@ -169,12 +195,6 @@ parse_state_free_contents_early (parse_state *ps)
ps->free_contents_early = true;
}
void
parse_state_retain_deriv (parse_state *ps)
{
ps->derivs.contents = NULL;
}
void
free_parse_state (parse_state *original_ps)
{
@@ -191,7 +211,7 @@ free_parse_state (parse_state *original_ps)
if (ps->state_items.contents)
gl_list_free (ps->state_items.contents);
if (ps->derivs.contents)
gl_list_free (ps->derivs.contents);
derivation_list_free (ps->derivs.contents);
}
if (ps->reference_count <= 0)
{
@@ -205,7 +225,7 @@ free_parse_state (parse_state *original_ps)
size_t
parse_state_hasher (const parse_state *ps, size_t max)
{
const ps_chunk *sis = &ps->state_items;
const struct si_chunk *sis = &ps->state_items;
return ((state_item *) sis->head_elt - state_items +
(state_item *) sis->tail_elt - state_items + sis->total_size) % max;
}
@@ -213,8 +233,8 @@ parse_state_hasher (const parse_state *ps, size_t max)
bool
parse_state_comparator (const parse_state *ps1, const parse_state *ps2)
{
const ps_chunk *sis1 = &ps1->state_items;
const ps_chunk *sis2 = &ps2->state_items;
const struct si_chunk *sis1 = &ps1->state_items;
const struct si_chunk *sis2 = &ps2->state_items;
return sis1->head_elt == sis2->head_elt
&& sis1->tail_elt == sis2->tail_elt
&& sis1->total_size == sis2->total_size;
@@ -245,10 +265,20 @@ parse_state_completed_steps (const parse_state *ps, int *shifts, int *production
*shifts = root_ps->state_items.total_size - count;
}
typedef void (*chunk_append_fn) (gl_list_t, const void *);
// A version of gl_list_add_last which has the chunk_append_fn
// signature.
void list_add_last (gl_list_t list, const void *elt)
{
gl_list_add_last (list, elt);
}
// takes an array of n gl_lists and flattens them into two list
// based off of the index split
static void
list_flatten_and_split (gl_list_t *list, gl_list_t *rets, int split, int n)
list_flatten_and_split (gl_list_t *list, gl_list_t *rets, int split, int n,
chunk_append_fn append_fn)
{
int ret_index = 0;
int ret_array = 0;
@@ -267,7 +297,7 @@ list_flatten_and_split (gl_list_t *list, gl_list_t *rets, int split, int n)
if (ret_index++ == split)
++ret_array;
if (rets[ret_array])
gl_list_add_last (rets[ret_array], si);
append_fn (rets[ret_array], si);
}
}
}
@@ -284,7 +314,7 @@ parse_state_list_new (void)
// Emulates a reduction on a parse state by popping some amount of
// derivations and state_items off of the parse_state and returning
// the result in ret. Returns the derivation of what's popped.
static gl_list_t
static derivation_list
parser_pop (parse_state *ps, int deriv_index,
int si_index, parse_state *ret)
{
@@ -305,13 +335,14 @@ parser_pop (parse_state *ps, int deriv_index,
gl_list_add_first (chunks[3], pn->derivs.contents);
}
}
gl_list_t popped_derivs =
gl_list_create_empty (GL_LINKED_LIST, NULL, NULL, NULL, true);
gl_list_t popped_derivs = derivation_list_new ();
gl_list_t ret_chunks[4] = { ret->state_items.contents, NULL,
ret->derivs.contents, popped_derivs
};
list_flatten_and_split (chunks, ret_chunks, si_index, 2);
list_flatten_and_split (chunks + 2, ret_chunks + 2, deriv_index, 2);
list_flatten_and_split (chunks, ret_chunks, si_index, 2,
list_add_last);
list_flatten_and_split (chunks + 2, ret_chunks + 2, deriv_index, 2,
(chunk_append_fn)derivation_list_append);
size_t s_size = gl_list_size (ret->state_items.contents);
ret->state_items.total_size = s_size;
if (s_size > 0)
@@ -346,18 +377,19 @@ parser_pop (parse_state *ps, int deriv_index,
void
parse_state_lists (parse_state *ps, gl_list_t *sitems,
gl_list_t *derivs)
derivation_list *derivs)
{
parse_state *temp = empty_parse_state ();
size_t si_size = ps->state_items.total_size;
size_t deriv_size = ps->derivs.total_size;
parser_pop (ps, si_size, deriv_size, temp);
derivation_list dl = parser_pop (ps, si_size, deriv_size, temp);
*sitems = temp->state_items.contents;
*derivs = temp->derivs.contents;
// prevent the return lists from being freed
temp->state_items.contents = NULL;
temp->derivs.contents = NULL;
free_parse_state (temp);
derivation_list_free (dl);
}
/**
@@ -379,8 +411,8 @@ nullable_closure (parse_state *ps, state_item *si, gl_list_t state_list)
state_item *nsi = state_items + sin;
current_ps = copy_parse_state (false, current_ps);
ps_chunk_append (&current_ps->state_items, nsi);
ps_chunk_append (&current_ps->derivs, derivation_new (sp, NULL));
ps_si_append (current_ps, nsi);
ps_derivs_append (current_ps, derivation_new_leaf (sp));
parse_state_retain (current_ps);
gl_list_add_last (state_list, current_ps);
}
@@ -401,8 +433,8 @@ simulate_transition (parse_state *ps)
if (si_next < 0)
return result;
parse_state *next_ps = copy_parse_state (false, ps);
ps_chunk_append (&next_ps->state_items, state_items + si_next);
ps_chunk_append (&next_ps->derivs, derivation_new (sym, NULL));
ps_si_append (next_ps, state_items + si_next);
ps_derivs_append (next_ps, derivation_new_leaf (sym));
parse_state_retain (next_ps);
gl_list_add_last (result, next_ps);
@@ -448,7 +480,7 @@ simulate_production (parse_state *ps, symbol_number compat_sym)
if (!compatible (*itm1, compat_sym) || !production_allowed (si, next))
continue;
parse_state *next_ps = copy_parse_state (false, ps);
ps_chunk_append (&next_ps->state_items, next);
ps_si_append (next_ps, next);
parse_state_retain (next_ps);
gl_list_add_last (result, next_ps);
if (next_ps->depth >= 0)
@@ -472,9 +504,9 @@ simulate_reduction (parse_state *ps, int rule_len, bitset symbol_set)
if (ps->depth >= 0)
d_size--; // account for dot
parse_state *new_root = empty_parse_state ();
gl_list_t popped_derivs = parser_pop (ps, d_size - rule_len,
s_size - rule_len - 1,
new_root);
derivation_list popped_derivs =
parser_pop (ps, d_size - rule_len,
s_size - rule_len - 1, new_root);
// update derivation
state_item *si = (state_item *) ps->state_items.tail_elt;
@@ -482,13 +514,12 @@ simulate_reduction (parse_state *ps, int rule_len, bitset symbol_set)
symbol_number lhs = r->lhs->number;
derivation *deriv = derivation_new (lhs, popped_derivs);
--new_root->depth;
ps_chunk_append (&new_root->derivs, deriv);
ps_derivs_append (new_root, deriv);
if (s_size != rule_len + 1)
{
state_item *tail = (state_item *) new_root->state_items.tail_elt;
ps_chunk_append (&new_root->state_items,
state_items + si_trans[tail - state_items]);
ps_si_append (new_root, state_items + si_trans[tail - state_items]);
parse_state_retain (new_root);
gl_list_add_last (result, new_root);
}
@@ -504,13 +535,13 @@ simulate_reduction (parse_state *ps, int rule_len, bitset symbol_set)
{
//Prepend the result from the reverse production
parse_state *copy = copy_parse_state (true, new_root);
ps_chunk_prepend (&copy->state_items, psis);
ps_si_prepend (copy, psis);
// Append the left hand side to the end of the parser state
copy = copy_parse_state (false, copy);
ps_chunk *sis = &copy->state_items;
struct si_chunk *sis = &copy->state_items;
const state_item *tail = sis->tail_elt;
ps_chunk_append (sis, state_items + si_trans[tail - state_items]);
ps_si_append (copy, state_items + si_trans[tail - state_items]);
parse_state_retain (copy);
gl_list_add_last (result, copy);
nullable_closure (copy, (state_item *) sis->tail_elt, result);
@@ -534,9 +565,9 @@ parser_prepend (parse_state *ps)
{
parse_state *copy = copy_parse_state (true, ps);
parse_state_retain (copy);
ps_chunk_prepend (&copy->state_items, state_items + sin);
ps_si_prepend (copy, state_items + sin);
if (SI_TRANSITION (head))
ps_chunk_prepend (&copy->derivs, derivation_new (prepend_sym, NULL));
ps_derivs_prepend (copy, derivation_new_leaf (prepend_sym));
gl_list_add_last (result, copy);
}
return result;

5
src/parse-simulation.h
View File

@@ -86,7 +86,6 @@ void parse_state_retain (parse_state *ps);
* when its reference count reaches 1. This is used to
* free memory while the parse state is in a hash set. */
void parse_state_free_contents_early (parse_state *ps);
void parse_state_retain_deriv (parse_state *ps);
void free_parse_state (parse_state *ps);
/* counts the amount of shift and production steps in this parse state */
@@ -94,7 +93,7 @@ void parse_state_completed_steps (const parse_state *ps, int *shifts, int *produ
/* parse state getters */
bool parse_state_derivation_completed (const parse_state *ps);
const derivation *parse_state_derivation (const parse_state *ps);
derivation *parse_state_derivation (const parse_state *ps);
const state_item *parse_state_head (const parse_state *ps);
const state_item *parse_state_tail (const parse_state *ps);
int parse_state_length (const parse_state *ps);
@@ -102,7 +101,7 @@ int parse_state_depth (const parse_state *ps);
/* returns the linked lists that the parse state is supposed to represent */
void parse_state_lists (parse_state *ps, gl_list_t *state_items,
gl_list_t *derivs);
derivation_list *derivs);
/* various functions that return a list of states based off of
* whatever operation is simulated. After whatever operation, every possible