regexp: removed alloca() is lre_exec() - added specific opcodes for \s and \S to have a smaller bytecode - optimized \b and \B

This commit is contained in:
Fabrice Bellard
2025-12-22 15:12:46 +01:00
parent 7bd1ae2c76
commit f1139494d1
5 changed files with 94 additions and 69 deletions

View File

@@ -31,6 +31,8 @@ DEF(char32, 5)
DEF(char32_i, 5)
DEF(dot, 1)
DEF(any, 1) /* same as dot but match any character including line terminator */
DEF(space, 1)
DEF(not_space, 1) /* must come after */
DEF(line_start, 1)
DEF(line_start_m, 1)
DEF(line_end, 1)

View File

@@ -34,7 +34,9 @@
/*
TODO:
- remove REOP_char_i and REOP_range_i by precomputing the case folding.
- add specific opcodes for simple unicode property tests so that the
generated bytecode is smaller.
- Add a lock step execution mode (=linear time execution guaranteed)
when the regular expression is "simple" i.e. no backreference nor
complicated lookahead. The opcodes are designed for this execution
@@ -1078,7 +1080,7 @@ static int get_class_atom(REParseState *s, REStringList *cr,
goto default_escape;
if (cr_init_char_range(s, cr, c))
return -1;
c = CLASS_RANGE_BASE;
c += CLASS_RANGE_BASE;
break;
case 'c':
c = *p;
@@ -1584,6 +1586,8 @@ static BOOL re_need_check_adv_and_capture_init(BOOL *pneed_capture_init,
case REOP_char32_i:
case REOP_dot:
case REOP_any:
case REOP_space:
case REOP_not_space:
need_check_adv = FALSE;
break;
case REOP_line_start:
@@ -2028,9 +2032,9 @@ static int re_parse_term(REParseState *s, BOOL is_backward_dir)
case 'b':
case 'B':
if (p[1] != 'b') {
re_emit_op(s, s->ignore_case ? REOP_not_word_boundary_i : REOP_not_word_boundary);
re_emit_op(s, s->ignore_case && s->is_unicode ? REOP_not_word_boundary_i : REOP_not_word_boundary);
} else {
re_emit_op(s, s->ignore_case ? REOP_word_boundary_i : REOP_word_boundary);
re_emit_op(s, s->ignore_case && s->is_unicode ? REOP_word_boundary_i : REOP_word_boundary);
}
p += 2;
break;
@@ -2167,8 +2171,15 @@ static int re_parse_term(REParseState *s, BOOL is_backward_dir)
if (is_backward_dir)
re_emit_op(s, REOP_prev);
if (c >= CLASS_RANGE_BASE) {
int ret;
int ret = 0;
/* optimize the common 'space' tests */
if (c == (CLASS_RANGE_BASE + CHAR_RANGE_s)) {
re_emit_op(s, REOP_space);
} else if (c == (CLASS_RANGE_BASE + CHAR_RANGE_S)) {
re_emit_op(s, REOP_not_space);
} else {
ret = re_emit_string_list(s, cr);
}
re_string_list_free(cr);
if (ret)
return -1;
@@ -2607,14 +2618,6 @@ static BOOL is_line_terminator(uint32_t c)
return (c == '\n' || c == '\r' || c == CP_LS || c == CP_PS);
}
static BOOL is_word_char(uint32_t c)
{
return ((c >= '0' && c <= '9') ||
(c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c == '_'));
}
#define GET_CHAR(c, cptr, cbuf_end, cbuf_type) \
do { \
if (cbuf_type == 0) { \
@@ -2769,7 +2772,7 @@ static no_inline int stack_realloc(REExecContext *s, size_t n)
/* return 1 if match, 0 if not match or < 0 if error. */
static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
uint8_t **regs, const uint8_t *pc, const uint8_t *cptr)
const uint8_t *pc, const uint8_t *cptr)
{
int opcode;
int cbuf_type;
@@ -2809,24 +2812,24 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
}
/* avoid saving the previous value if already saved */
#define SAVE_REG(idx, value) \
#define SAVE_CAPTURE_CHECK(idx, value) \
{ \
StackElem *sp1; \
sp1 = sp; \
for(;;) { \
if (sp1 > bp) { \
if (sp1[-2].val == -(int)(idx + 1)) \
if (sp1[-2].val == idx) \
break; \
sp1 -= 2; \
} else { \
CHECK_STACK_SPACE(2); \
sp[0].val = -(int)(idx + 1); \
sp[1].ptr = regs[idx]; \
sp[0].val = idx; \
sp[1].ptr = capture[idx]; \
sp += 2; \
break; \
} \
} \
regs[idx] = (value); \
capture[idx] = (value); \
}
@@ -2851,13 +2854,9 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
REExecStateEnum type;
if (bp == s->stack_buf)
return 0;
/* undo the modifications to capture[] and regs[] */
/* undo the modifications to capture[] */
while (sp > bp) {
intptr_t idx2 = sp[-2].val;
if (idx2 >= 0)
capture[idx2] = sp[-1].ptr;
else
regs[-idx2 - 1] = sp[-1].ptr;
capture[sp[-2].val] = sp[-1].ptr;
sp -= 2;
}
@@ -2910,13 +2909,9 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
for(;;) {
REExecStateEnum type;
type = bp[-1].bp.type;
/* undo the modifications to capture[] and regs[] */
/* undo the modifications to capture[] */
while (sp > bp) {
intptr_t idx2 = sp[-2].val;
if (idx2 >= 0)
capture[idx2] = sp[-1].ptr;
else
regs[-idx2 - 1] = sp[-1].ptr;
capture[sp[-2].val] = sp[-1].ptr;
sp -= 2;
}
pc = sp[-3].ptr;
@@ -3019,6 +3014,20 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
goto no_match;
GET_CHAR(c, cptr, cbuf_end, cbuf_type);
break;
case REOP_space:
if (cptr == cbuf_end)
goto no_match;
GET_CHAR(c, cptr, cbuf_end, cbuf_type);
if (!lre_is_space(c))
goto no_match;
break;
case REOP_not_space:
if (cptr == cbuf_end)
goto no_match;
GET_CHAR(c, cptr, cbuf_end, cbuf_type);
if (lre_is_space(c))
goto no_match;
break;
case REOP_save_start:
case REOP_save_end:
val = *pc++;
@@ -3044,20 +3053,20 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
}
break;
case REOP_set_i32:
idx = pc[0];
idx = 2 * s->capture_count + pc[0];
val = get_u32(pc + 1);
pc += 5;
SAVE_REG(idx, (void *)(uintptr_t)val);
SAVE_CAPTURE_CHECK(idx, (void *)(uintptr_t)val);
break;
case REOP_loop:
{
uint32_t val2;
idx = pc[0];
idx = 2 * s->capture_count + pc[0];
val = get_u32(pc + 1);
pc += 5;
val2 = (uintptr_t)regs[idx] - 1;
SAVE_REG(idx, (void *)(uintptr_t)val2);
val2 = (uintptr_t)capture[idx] - 1;
SAVE_CAPTURE_CHECK(idx, (void *)(uintptr_t)val2);
if (val2 != 0) {
pc += (int)val;
if (lre_poll_timeout(s))
@@ -3072,14 +3081,14 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
{
const uint8_t *pc1;
uint32_t val2, limit;
idx = pc[0];
idx = 2 * s->capture_count + pc[0];
limit = get_u32(pc + 1);
val = get_u32(pc + 5);
pc += 9;
/* decrement the counter */
val2 = (uintptr_t)regs[idx] - 1;
SAVE_REG(idx, (void *)(uintptr_t)val2);
val2 = (uintptr_t)capture[idx] - 1;
SAVE_CAPTURE_CHECK(idx, (void *)(uintptr_t)val2);
if (val2 > limit) {
/* normal loop if counter > limit */
@@ -3090,7 +3099,7 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
/* check advance */
if ((opcode == REOP_loop_check_adv_split_goto_first ||
opcode == REOP_loop_check_adv_split_next_first) &&
regs[idx + 1] == cptr &&
capture[idx + 1] == cptr &&
val2 != limit) {
goto no_match;
}
@@ -3116,14 +3125,14 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
}
break;
case REOP_set_char_pos:
idx = pc[0];
idx = 2 * s->capture_count + pc[0];
pc++;
SAVE_REG(idx, (uint8_t *)cptr);
SAVE_CAPTURE_CHECK(idx, (uint8_t *)cptr);
break;
case REOP_check_advance:
idx = pc[0];
idx = 2 * s->capture_count + pc[0];
pc++;
if (regs[idx] == cptr)
if (capture[idx] == cptr)
goto no_match;
break;
case REOP_word_boundary:
@@ -3139,18 +3148,22 @@ static intptr_t lre_exec_backtrack(REExecContext *s, uint8_t **capture,
v1 = FALSE;
} else {
PEEK_PREV_CHAR(c, cptr, s->cbuf, cbuf_type);
if (ignore_case)
c = lre_canonicalize(c, s->is_unicode);
v1 = is_word_char(c);
if (c < 256) {
v1 = (lre_is_word_byte(c) != 0);
} else {
v1 = ignore_case && (c == 0x017f || c == 0x212a);
}
}
/* current char */
if (cptr >= cbuf_end) {
v2 = FALSE;
} else {
PEEK_CHAR(c, cptr, cbuf_end, cbuf_type);
if (ignore_case)
c = lre_canonicalize(c, s->is_unicode);
v2 = is_word_char(c);
if (c < 256) {
v2 = (lre_is_word_byte(c) != 0);
} else {
v2 = ignore_case && (c == 0x017f || c == 0x212a);
}
}
if (v1 ^ v2 ^ is_boundary)
goto no_match;
@@ -3315,8 +3328,7 @@ int lre_exec(uint8_t **capture,
int cbuf_type, void *opaque)
{
REExecContext s_s, *s = &s_s;
int re_flags, i, ret, register_count;
uint8_t **regs;
int re_flags, i, ret;
const uint8_t *cptr;
re_flags = lre_get_flags(bc_buf);
@@ -3335,10 +3347,6 @@ int lre_exec(uint8_t **capture,
for(i = 0; i < s->capture_count * 2; i++)
capture[i] = NULL;
/* XXX: modify the API so that the registers are allocated after
the captures to suppress some tests */
register_count = bc_buf[RE_HEADER_REGISTER_COUNT];
regs = alloca(register_count * sizeof(regs[0]));
cptr = cbuf + (cindex << cbuf_type);
if (0 < cindex && cindex < clen && s->cbuf_type == 2) {
@@ -3348,13 +3356,19 @@ int lre_exec(uint8_t **capture,
}
}
ret = lre_exec_backtrack(s, capture, regs, bc_buf + RE_HEADER_LEN,
cptr);
ret = lre_exec_backtrack(s, capture, bc_buf + RE_HEADER_LEN, cptr);
if (s->stack_buf != s->static_stack_buf)
lre_realloc(s->opaque, s->stack_buf, 0);
return ret;
}
int lre_get_alloc_count(const uint8_t *bc_buf)
{
return bc_buf[RE_HEADER_CAPTURE_COUNT] * 2 +
bc_buf[RE_HEADER_REGISTER_COUNT];
}
int lre_get_capture_count(const uint8_t *bc_buf)
{
return bc_buf[RE_HEADER_CAPTURE_COUNT];
@@ -3393,7 +3407,7 @@ int main(int argc, char **argv)
int len, flags, ret, i;
uint8_t *bc;
char error_msg[64];
uint8_t *capture[CAPTURE_COUNT_MAX * 2];
uint8_t *capture;
const char *input;
int input_len, capture_count;
@@ -3412,6 +3426,7 @@ int main(int argc, char **argv)
input = argv[3];
input_len = strlen(input);
capture = malloc(sizeof(capture[0]) * lre_get_alloc_count(bc));
ret = lre_exec(capture, bc, (uint8_t *)input, 0, input_len, 0, NULL);
printf("ret=%d\n", ret);
if (ret == 1) {
@@ -3427,6 +3442,7 @@ int main(int argc, char **argv)
printf("\n");
}
}
free(capture);
return 0;
}
#endif

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@@ -46,6 +46,7 @@
uint8_t *lre_compile(int *plen, char *error_msg, int error_msg_size,
const char *buf, size_t buf_len, int re_flags,
void *opaque);
int lre_get_alloc_count(const uint8_t *bc_buf);
int lre_get_capture_count(const uint8_t *bc_buf);
int lre_get_flags(const uint8_t *bc_buf);
const char *lre_get_groupnames(const uint8_t *bc_buf);

View File

@@ -147,6 +147,11 @@ static inline int lre_is_id_continue_byte(uint8_t c) {
UNICODE_C_DIGIT);
}
static inline int lre_is_word_byte(uint8_t c) {
return lre_ctype_bits[c] & (UNICODE_C_UPPER | UNICODE_C_LOWER |
UNICODE_C_UNDER | UNICODE_C_DIGIT);
}
int lre_is_space_non_ascii(uint32_t c);
static inline int lre_is_space(uint32_t c) {

View File

@@ -45487,7 +45487,6 @@ static JSValue js_string_split(JSContext *ctx, JSValueConst this_val,
goto add_tail;
goto done;
}
q = p;
for (q = p; (q += !r) <= s - r - !r; q = p = e + r) {
e = string_indexof(sp, rp, q);
if (e < 0)
@@ -47423,7 +47422,7 @@ static JSValue js_regexp_exec(JSContext *ctx, JSValueConst this_val,
JSValue indices, indices_groups;
uint8_t *re_bytecode;
uint8_t **capture, *str_buf;
int rc, capture_count, shift, i, re_flags;
int rc, capture_count, shift, i, re_flags, alloc_count;
int64_t last_index;
const char *group_name_ptr;
JSObject *p_obj;
@@ -47453,12 +47452,13 @@ static JSValue js_regexp_exec(JSContext *ctx, JSValueConst this_val,
last_index = 0;
}
str = JS_VALUE_GET_STRING(str_val);
capture_count = lre_get_capture_count(re_bytecode);
if (capture_count > 0) {
capture = js_malloc(ctx, sizeof(capture[0]) * capture_count * 2);
alloc_count = lre_get_alloc_count(re_bytecode);
if (alloc_count > 0) {
capture = js_malloc(ctx, sizeof(capture[0]) * alloc_count);
if (!capture)
goto fail;
}
capture_count = lre_get_capture_count(re_bytecode);
shift = str->is_wide_char;
str_buf = str->u.str8;
if (last_index > str->len) {
@@ -47642,7 +47642,7 @@ static JSValue js_regexp_replace(JSContext *ctx, JSValueConst this_val, JSValueC
uint8_t *re_bytecode;
int ret;
uint8_t **capture, *str_buf;
int capture_count, shift, re_flags;
int capture_count, alloc_count, shift, re_flags;
int next_src_pos, start, end;
int64_t last_index;
StringBuffer b_s, *b = &b_s;
@@ -47676,12 +47676,13 @@ static JSValue js_regexp_replace(JSContext *ctx, JSValueConst this_val, JSValueC
if (js_regexp_get_lastIndex(ctx, &last_index, this_val))
goto fail;
}
capture_count = lre_get_capture_count(re_bytecode);
if (capture_count > 0) {
capture = js_malloc(ctx, sizeof(capture[0]) * capture_count * 2);
alloc_count = lre_get_alloc_count(re_bytecode);
if (alloc_count > 0) {
capture = js_malloc(ctx, sizeof(capture[0]) * alloc_count);
if (!capture)
goto fail;
}
capture_count = lre_get_capture_count(re_bytecode);
fullUnicode = ((re_flags & (LRE_FLAG_UNICODE | LRE_FLAG_UNICODE_SETS)) != 0);
shift = str->is_wide_char;
str_buf = str->u.str8;