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cex: fix parse state leaks

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* src/parse_simulation.c: Fix bug in parse_state_free.
Free new_root when simulate_reduction generates zero states.

* src/parse-simulation.c, src/parse-simulation.h
(parse_state_list, parse_state_list_append): New.
* src/parse-simulation.c, src/parse-simulation.h,
* src/counterexample.c: Replace all uses of lists of parse states and
appends to parse_state_lists with the new API.
This commit is contained in:
Vincent Imbimbo
2020-05-21 22:13:12 -04:00
committed by Akim Demaille
parent 35c4a8e65e
commit 150b2318ed
3 changed files with 53 additions and 39 deletions
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67
src/parse-simulation.c
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@@ -199,7 +199,8 @@ void
free_parse_state (parse_state *original_ps)
{
bool free_contents = true;
for (parse_state *ps = original_ps; ps && free_contents; ps = ps->parent)
parse_state *parent_ps = NULL;
for (parse_state *ps = original_ps; ps && free_contents; ps = parent_ps)
{
--ps->reference_count;
free_contents = (ps->reference_count == 1 && ps->free_contents_early)
@@ -213,11 +214,11 @@ free_parse_state (parse_state *original_ps)
if (ps->derivs.contents)
derivation_list_free (ps->derivs.contents);
}
parent_ps = ps->parent;
if (ps->reference_count <= 0)
{
free (ps);
++frees;
break;
}
}
}
@@ -303,7 +304,7 @@ list_flatten_and_split (gl_list_t *list, gl_list_t *rets, int split, int n,
}
}
static gl_list_t
static parse_state_list
parse_state_list_new (void)
{
return gl_list_create_empty (GL_LINKED_LIST, NULL, NULL,
@@ -311,6 +312,12 @@ parse_state_list_new (void)
true);
}
void parse_state_list_append (parse_state_list pl, parse_state *ps)
{
parse_state_retain (ps);
gl_list_add_last (pl, ps);
}
// 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.
@@ -397,7 +404,7 @@ parse_state_lists (parse_state *ps, gl_list_t *sitems,
* nullable symbols whenever possible from the given state_item.
*/
void
nullable_closure (parse_state *ps, state_item *si, gl_list_t state_list)
nullable_closure (parse_state *ps, state_item *si, parse_state_list state_list)
{
parse_state *current_ps = ps;
state_item_number prev_sin = si - state_items;
@@ -413,8 +420,7 @@ nullable_closure (parse_state *ps, state_item *si, gl_list_t state_list)
current_ps = copy_parse_state (false, current_ps);
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);
parse_state_list_append (state_list, current_ps);
}
}
@@ -435,8 +441,7 @@ simulate_transition (parse_state *ps)
parse_state *next_ps = copy_parse_state (false, ps);
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);
parse_state_list_append (result, next_ps);
nullable_closure (next_ps, state_items + si_next, result);
return result;
@@ -481,8 +486,7 @@ simulate_production (parse_state *ps, symbol_number compat_sym)
continue;
parse_state *next_ps = copy_parse_state (false, ps);
ps_si_append (next_ps, next);
parse_state_retain (next_ps);
gl_list_add_last (result, next_ps);
parse_state_list_append (result, next_ps);
if (next_ps->depth >= 0)
++next_ps->depth;
nullable_closure (next_ps, next, result);
@@ -520,8 +524,7 @@ simulate_reduction (parse_state *ps, int rule_len, bitset symbol_set)
{
state_item *tail = (state_item *) new_root->state_items.tail_elt;
ps_si_append (new_root, state_items + si_trans[tail - state_items]);
parse_state_retain (new_root);
gl_list_add_last (result, new_root);
parse_state_list_append (result, new_root);
}
else
{
@@ -529,22 +532,31 @@ simulate_reduction (parse_state *ps, int rule_len, bitset symbol_set)
// with possible source state-items.
const state_item *head = ps->state_items.head_elt;
gl_list_t prev = lssi_reverse_production (head, symbol_set);
gl_list_iterator_t it = gl_list_iterator (prev);
state_item *psis;
while (gl_list_iterator_next (&it, (const void **) &psis, NULL))
// TODO: better understand what causes this case.
if (gl_list_size (prev) == 0)
{
//Prepend the result from the reverse production
parse_state *copy = copy_parse_state (true, new_root);
ps_si_prepend (copy, psis);
// new_root needs to have an RC of 1 to be freed correctly here.
parse_state_retain (new_root);
free_parse_state (new_root);
}
else
{
gl_list_iterator_t it = gl_list_iterator (prev);
state_item *psis;
while (gl_list_iterator_next (&it, (const void **) &psis, NULL))
{
//Prepend the result from the reverse production
parse_state *copy = copy_parse_state (true, new_root);
ps_si_prepend (copy, psis);
// Append the left hand side to the end of the parser state
copy = copy_parse_state (false, copy);
struct si_chunk *sis = &copy->state_items;
const state_item *tail = sis->tail_elt;
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);
// Append the left hand side to the end of the parser state
copy = copy_parse_state (false, copy);
struct si_chunk *sis = &copy->state_items;
const state_item *tail = sis->tail_elt;
ps_si_append (copy, state_items + si_trans[tail - state_items]);
parse_state_list_append (result, copy);
nullable_closure (copy, (state_item *) sis->tail_elt, result);
}
}
gl_list_free (prev);
}
@@ -564,11 +576,10 @@ parser_prepend (parse_state *ps)
BITSET_FOR_EACH (biter, prev, sin, 0)
{
parse_state *copy = copy_parse_state (true, ps);
parse_state_retain (copy);
ps_si_prepend (copy, state_items + sin);
if (SI_TRANSITION (head))
ps_derivs_prepend (copy, derivation_new_leaf (prepend_sym));
gl_list_add_last (result, copy);
parse_state_list_append (result, copy);
}
return result;
}