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Add runtime assertion on unhandled case in concat_fsas()

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Camden Dixie O'Brien 2024-10-27 13:21:10 +00:00
parent edc14bc1de
commit 755f3f6805
1 changed files with 10 additions and 4 deletions
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14
lib/construct.c
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@ -39,6 +39,10 @@ static void construct_term(const regex_term_t *term, fsa_t *out)
static void concat_fsas(fsa_t *base, const fsa_t *other) static void concat_fsas(fsa_t *base, const fsa_t *other)
{ {
// TODO: Handle the other's final state having transition rules.
assert(0 == other->states[0].count);
// Copy states other than the final state (index zero) to base.
const int new_count = base->count + other->count - 1; const int new_count = base->count + other->count - 1;
if (base->capacity < new_count) { if (base->capacity < new_count) {
do do
@ -47,23 +51,25 @@ static void concat_fsas(fsa_t *base, const fsa_t *other)
base->states = realloc(base->states, base->capacity); base->states = realloc(base->states, base->capacity);
assert(base->states); assert(base->states);
} }
const int copy_size = (other->count - 1) * sizeof(fsa_state_t); const int copy_size = (other->count - 1) * sizeof(fsa_state_t);
memcpy(&base->states[base->count], &other->states[1], copy_size); memcpy(&base->states[base->count], &other->states[1], copy_size);
const int id_offset = base->count - 1; // Retarget new states' rules.
for (int i = base->count; i < new_count; ++i) { for (int i = base->count; i < new_count; ++i) {
fsa_state_t *state = &base->states[i]; fsa_state_t *state = &base->states[i];
for (int j = 0; j < state->count; ++j) { for (int j = 0; j < state->count; ++j) {
if (0 == state->rules[j].next) if (0 == state->rules[j].next)
state->rules[j].next = base->initial; state->rules[j].next = base->initial;
else else
state->rules[j].next += id_offset; // States' indices have increased by one less than the
// base count, as the final state came before them and
// was not copied.
state->rules[j].next += base->count - 1;
} }
} }
base->initial = other->initial + base->count - 1;
base->count = new_count; base->count = new_count;
base->initial = other->initial + id_offset;
free(other->states[0].rules); free(other->states[0].rules);
free(other->states); free(other->states);