diff options
Diffstat (limited to 'src/backend/regex/regc_nfa.c')
| -rw-r--r-- | src/backend/regex/regc_nfa.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/backend/regex/regc_nfa.c b/src/backend/regex/regc_nfa.c index 60fb0bec5d7..06bbcae0ee3 100644 --- a/src/backend/regex/regc_nfa.c +++ b/src/backend/regex/regc_nfa.c @@ -1490,6 +1490,7 @@ removetraverse(struct nfa *nfa, { case PLAIN: case EMPTY: + case CANTMATCH: /* nothing to do */ break; case AHEAD: @@ -1627,6 +1628,12 @@ optimize(struct nfa *nfa, if (verbose) fprintf(f, "\ninitial cleanup:\n"); #endif + /* If we have any CANTMATCH arcs, drop them; but this is uncommon */ + if (nfa->flags & HASCANTMATCH) + { + removecantmatch(nfa); + nfa->flags &= ~HASCANTMATCH; + } cleanup(nfa); /* may simplify situation */ #ifdef REG_DEBUG if (verbose) @@ -2951,6 +2958,34 @@ clonesuccessorstates(struct nfa *nfa, } /* + * removecantmatch - remove CANTMATCH arcs, which are no longer useful + * once we are done with the parsing phase. (We need them only to + * preserve connectedness of NFA subgraphs during parsing.) + */ +static void +removecantmatch(struct nfa *nfa) +{ + struct state *s; + + for (s = nfa->states; s != NULL; s = s->next) + { + struct arc *a; + struct arc *nexta; + + for (a = s->outs; a != NULL; a = nexta) + { + nexta = a->outchain; + if (a->type == CANTMATCH) + { + freearc(nfa, a); + if (NISERR()) + return; + } + } + } +} + +/* * cleanup - clean up NFA after optimizations */ static void @@ -3659,6 +3694,8 @@ dumpnfa(struct nfa *nfa, fprintf(f, ", eol [%ld]", (long) nfa->eos[1]); if (nfa->flags & HASLACONS) fprintf(f, ", haslacons"); + if (nfa->flags & HASCANTMATCH) + fprintf(f, ", hascantmatch"); if (nfa->flags & MATCHALL) { fprintf(f, ", minmatchall %d", nfa->minmatchall); @@ -3781,6 +3818,9 @@ dumparc(struct arc *a, break; case EMPTY: break; + case CANTMATCH: + fprintf(f, "X"); + break; default: fprintf(f, "0x%x/0%lo", a->type, (long) a->co); break; |