There are too many gl_list_t in there, it's hard to understand what is
going on. Introduce and use more precise types. I sure can be wrong
in some places, it's hard to tell without proper tool support.
* src/counterexample.c, src/lssi.c, src/lssi.h, src/parse-simulation.c,
* src/parse-simulation.h, src/state-item.c, src/state-item.h
(si_bfs_node_list, search_state_list, ssb_list, lssi_list)
(state_item_list): New.
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.
* 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.
* 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.
