(re_search_internal): Limit search to the beginning of the buffer if the initial states are empty for contexts that do not include CONTEXT_BEGBUF or, if !preg->newline_anchor, that do not include any one of CONTEXT_BEGBUF and CONTEXT_NEWLINE.

This commit is contained in:
Ulrich Drepper 2003-12-17 22:58:24 +00:00
parent 219ebb6d8d
commit c70f81dd2c

View File

@ -597,6 +597,24 @@ re_search_internal (preg, string, length, start, range, stop, nmatch, pmatch,
|| dfa->init_state_begbuf == NULL, 0))
return REG_NOMATCH;
#ifdef DEBUG
/* We assume front-end functions already check them. */
assert (start + range >= 0 && start + range <= length);
#endif
/* If initial states with non-begbuf contexts have no elements,
the regex must be anchored. If preg->newline_anchor is set,
we'll never use init_state_nl, so do not check it. */
if (dfa->init_state->nodes.nelem == 0
&& dfa->init_state_word->nodes.nelem == 0
&& (dfa->init_state_nl->nodes.nelem == 0
|| !preg->newline_anchor))
{
if (start != 0 && start + range != 0)
return REG_NOMATCH;
start = range = 0;
}
re_node_set_init_empty (&empty_set);
memset (&mctx, '\0', sizeof (re_match_context_t));
@ -630,11 +648,6 @@ re_search_internal (preg, string, length, start, range, stop, nmatch, pmatch,
else
mctx.state_log = NULL;
#ifdef DEBUG
/* We assume front-end functions already check them. */
assert (start + range >= 0 && start + range <= length);
#endif
match_first = start;
input.tip_context = ((eflags & REG_NOTBOL) ? CONTEXT_BEGBUF
: CONTEXT_NEWLINE | CONTEXT_BEGBUF);