diff options
| -rw-r--r-- | src/nvim/regexp.c | 24 | ||||
| -rw-r--r-- | src/nvim/regexp.h | 1 | ||||
| -rw-r--r-- | src/nvim/regexp_nfa.c | 10 | ||||
| -rw-r--r-- | src/nvim/version.c | 2 |
4 files changed, 24 insertions, 13 deletions
diff --git a/src/nvim/regexp.c b/src/nvim/regexp.c index 3e287e590b..dddd347822 100644 --- a/src/nvim/regexp.c +++ b/src/nvim/regexp.c @@ -6984,10 +6984,12 @@ regprog_T *vim_regcomp(char_u *expr_arg, int re_flags) /* * First try the NFA engine, unless backtracking was requested. */ - if (regexp_engine != BACKTRACKING_ENGINE) - prog = nfa_regengine.regcomp(expr, re_flags); - else + if (regexp_engine != BACKTRACKING_ENGINE) { + prog = nfa_regengine.regcomp(expr, + re_flags + (regexp_engine == AUTOMATIC_ENGINE ? RE_AUTO : 0)); + } else { prog = bt_regengine.regcomp(expr, re_flags); + } // Check for error compiling regexp with initial engine. if (prog == NULL) { @@ -7003,15 +7005,13 @@ regprog_T *vim_regcomp(char_u *expr_arg, int re_flags) BT_REGEXP_DEBUG_LOG_NAME); } #endif - // If the NFA engine failed, try the backtracking engine. - // Disabled for now, both engines fail on the same patterns. - // Re-enable when regcomp() fails when the pattern would work better - // with the other engine. - // - // if (regexp_engine == AUTOMATIC_ENGINE) { - // prog = bt_regengine.regcomp(expr, re_flags); - // regexp_engine = BACKTRACKING_ENGINE; - // } + // If the NFA engine failed, try the backtracking engine. The NFA engine + // also fails for patterns that it can't handle well but are still valid + // patterns, thus a retry should work. + if (regexp_engine == AUTOMATIC_ENGINE) { + regexp_engine = BACKTRACKING_ENGINE; + prog = bt_regengine.regcomp(expr, re_flags); + } } if (prog != NULL) { diff --git a/src/nvim/regexp.h b/src/nvim/regexp.h index 1af01fe411..37513d8c27 100644 --- a/src/nvim/regexp.h +++ b/src/nvim/regexp.h @@ -5,6 +5,7 @@ #define RE_MAGIC 1 /* 'magic' option */ #define RE_STRING 2 /* match in string instead of buffer text */ #define RE_STRICT 4 /* don't allow [abc] without ] */ +#define RE_AUTO 8 /* automatic engine selection */ /* values for reg_do_extmatch */ #define REX_SET 1 /* to allow \z\(...\), */ diff --git a/src/nvim/regexp_nfa.c b/src/nvim/regexp_nfa.c index 4ef91814ac..d9dc09b623 100644 --- a/src/nvim/regexp_nfa.c +++ b/src/nvim/regexp_nfa.c @@ -315,6 +315,9 @@ typedef struct { int has_pim; /* TRUE when any state has a PIM */ } nfa_list_T; +/// re_flags passed to nfa_regcomp(). +static int nfa_re_flags; + /* NFA regexp \ze operator encountered. */ static int nfa_has_zend; @@ -1894,6 +1897,12 @@ static int nfa_regpiece(void) return OK; } + // The engine is very inefficient (uses too many states) when the maximum is + // much larger than the minimum. Bail out if we can use the other engine. + if ((nfa_re_flags & RE_AUTO) && maxval > minval + 200) { + return FAIL; + } + /* Ignore previous call to nfa_regatom() */ post_ptr = post_start + my_post_start; /* Save parse state after the repeated atom and the \{} */ @@ -6287,6 +6296,7 @@ static regprog_T *nfa_regcomp(char_u *expr, int re_flags) return NULL; nfa_regengine.expr = expr; + nfa_re_flags = re_flags; init_class_tab(); diff --git a/src/nvim/version.c b/src/nvim/version.c index 2ebc080eb8..d43108d29a 100644 --- a/src/nvim/version.c +++ b/src/nvim/version.c @@ -216,7 +216,7 @@ static int included_patches[] = { //596 NA 595, 594, - //593, + 593, //592 NA //591 NA 590, |