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tre-parse.c
1739 lines (1597 loc) · 43.8 KB
/
tre-parse.c
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/*
tre-parse.c - Regexp parser
This software is released under a BSD-style license.
See the file LICENSE for details and copyright.
*/
/*
This parser is just a simple recursive descent parser for POSIX.2
regexps. The parser supports both the obsolete default syntax and
the "extended" syntax, and some nonstandard extensions.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */
#include <string.h>
#include <assert.h>
#include <limits.h>
#include "xmalloc.h"
#include "tre-mem.h"
#include "tre-ast.h"
#include "tre-stack.h"
#include "tre-parse.h"
/* Characters with special meanings in regexp syntax. */
#define CHAR_PIPE L'|'
#define CHAR_LPAREN L'('
#define CHAR_RPAREN L')'
#define CHAR_LBRACE L'{'
#define CHAR_RBRACE L'}'
#define CHAR_LBRACKET L'['
#define CHAR_RBRACKET L']'
#define CHAR_MINUS L'-'
#define CHAR_STAR L'*'
#define CHAR_QUESTIONMARK L'?'
#define CHAR_PLUS L'+'
#define CHAR_PERIOD L'.'
#define CHAR_COLON L':'
#define CHAR_EQUAL L'='
#define CHAR_COMMA L','
#define CHAR_CARET L'^'
#define CHAR_DOLLAR L'$'
#define CHAR_BACKSLASH L'\\'
#define CHAR_HASH L'#'
#define CHAR_TILDE L'~'
/* Some macros for expanding \w, \s, etc. */
static const struct tre_macro_struct {
const char c;
const char *expansion;
} tre_macros[] =
{ {'t', "\t"}, {'n', "\n"}, {'r', "\r"},
{'f', "\f"}, {'a', "\a"}, {'e', "\033"},
{'w', "[[:alnum:]_]"}, {'W', "[^[:alnum:]_]"}, {'s', "[[:space:]]"},
{'S', "[^[:space:]]"}, {'d', "[[:digit:]]"}, {'D', "[^[:digit:]]"},
{ 0, NULL }
};
/* Expands a macro delimited by `regex' and `regex_end' to `buf', which
must have at least `len' items. Sets buf[0] to zero if the there
is no match in `tre_macros'. */
static void
tre_expand_macro(const tre_char_t *regex, const tre_char_t *regex_end,
tre_char_t *buf, size_t buf_len)
{
int i;
buf[0] = 0;
if (regex >= regex_end)
return;
for (i = 0; tre_macros[i].expansion; i++)
{
if (tre_macros[i].c == *regex)
{
unsigned int j;
DPRINT(("Expanding macro '%c' => '%s'\n",
tre_macros[i].c, tre_macros[i].expansion));
for (j = 0; tre_macros[i].expansion[j] && j < buf_len; j++)
buf[j] = tre_macros[i].expansion[j];
buf[j] = 0;
break;
}
}
}
static reg_errcode_t
tre_new_item(tre_mem_t mem, int min, int max, int *i, int *max_i,
tre_ast_node_t ***items)
{
reg_errcode_t status;
tre_ast_node_t **array = *items;
/* Allocate more space if necessary. */
if (*i >= *max_i)
{
tre_ast_node_t **new_items;
DPRINT(("out of array space, i = %d\n", *i));
/* If the array is already 1024 items large, give up -- there's
probably an error in the regexp (e.g. not a '\0' terminated
string and missing ']') */
if (*max_i > 1024)
return REG_ESPACE;
*max_i *= 2;
new_items = xrealloc(array, sizeof(*items) * *max_i);
if (new_items == NULL)
return REG_ESPACE;
*items = array = new_items;
}
array[*i] = tre_ast_new_literal(mem, min, max, -1);
status = array[*i] == NULL ? REG_ESPACE : REG_OK;
(*i)++;
return status;
}
/* Expands a character class to character ranges. */
static reg_errcode_t
tre_expand_ctype(tre_mem_t mem, tre_ctype_t class, tre_ast_node_t ***items,
int *i, int *max_i, int cflags)
{
reg_errcode_t status = REG_OK;
tre_cint_t c;
int j, min = -1, max = 0;
assert(TRE_MB_CUR_MAX == 1);
DPRINT((" expanding class to character ranges\n"));
for (j = 0; (j < 256) && (status == REG_OK); j++)
{
c = (tre_cint_t) j;
if (tre_isctype(c, class)
|| ((cflags & REG_ICASE)
&& (tre_isctype(tre_tolower(c), class)
|| tre_isctype(tre_toupper(c), class))))
{
if (min < 0)
min = c;
max = c;
}
else if (min >= 0)
{
DPRINT((" range %c (%d) to %c (%d)\n", min, min, max, max));
status = tre_new_item(mem, min, max, i, max_i, items);
min = -1;
}
}
if (min >= 0 && status == REG_OK)
status = tre_new_item(mem, min, max, i, max_i, items);
return status;
}
static int
tre_compare_items(const void *a, const void *b)
{
const tre_ast_node_t *node_a = *(tre_ast_node_t * const *)a;
const tre_ast_node_t *node_b = *(tre_ast_node_t * const *)b;
tre_literal_t *l_a = node_a->obj, *l_b = node_b->obj;
int a_min = l_a->code_min, b_min = l_b->code_min;
if (a_min < b_min)
return -1;
else if (a_min > b_min)
return 1;
else
return 0;
}
#ifndef TRE_USE_SYSTEM_WCTYPE
/* isalnum() and the rest may be macros, so wrap them to functions. */
int tre_isalnum_func(tre_cint_t c) { return tre_isalnum(c); }
int tre_isalpha_func(tre_cint_t c) { return tre_isalpha(c); }
#ifdef tre_isascii
int tre_isascii_func(tre_cint_t c) { return tre_isascii(c); }
#else /* !tre_isascii */
int tre_isascii_func(tre_cint_t c) { return !(c >> 7); }
#endif /* !tre_isascii */
#ifdef tre_isblank
int tre_isblank_func(tre_cint_t c) { return tre_isblank(c); }
#else /* !tre_isblank */
int tre_isblank_func(tre_cint_t c) { return ((c == ' ') || (c == '\t')); }
#endif /* !tre_isblank */
int tre_iscntrl_func(tre_cint_t c) { return tre_iscntrl(c); }
int tre_isdigit_func(tre_cint_t c) { return tre_isdigit(c); }
int tre_isgraph_func(tre_cint_t c) { return tre_isgraph(c); }
int tre_islower_func(tre_cint_t c) { return tre_islower(c); }
int tre_isprint_func(tre_cint_t c) { return tre_isprint(c); }
int tre_ispunct_func(tre_cint_t c) { return tre_ispunct(c); }
int tre_isspace_func(tre_cint_t c) { return tre_isspace(c); }
int tre_isupper_func(tre_cint_t c) { return tre_isupper(c); }
int tre_isxdigit_func(tre_cint_t c) { return tre_isxdigit(c); }
struct {
char *name;
int (*func)(tre_cint_t);
} tre_ctype_map[] = {
{ "alnum", &tre_isalnum_func },
{ "alpha", &tre_isalpha_func },
#ifdef tre_isascii
{ "ascii", &tre_isascii_func },
#endif /* tre_isascii */
#ifdef tre_isblank
{ "blank", &tre_isblank_func },
#endif /* tre_isblank */
{ "cntrl", &tre_iscntrl_func },
{ "digit", &tre_isdigit_func },
{ "graph", &tre_isgraph_func },
{ "lower", &tre_islower_func },
{ "print", &tre_isprint_func },
{ "punct", &tre_ispunct_func },
{ "space", &tre_isspace_func },
{ "upper", &tre_isupper_func },
{ "xdigit", &tre_isxdigit_func },
{ NULL, NULL}
};
tre_ctype_t tre_ctype(const char *name)
{
int i;
for (i = 0; tre_ctype_map[i].name != NULL; i++)
{
if (strcmp(name, tre_ctype_map[i].name) == 0)
return tre_ctype_map[i].func;
}
return (tre_ctype_t)0;
}
#endif /* !TRE_USE_SYSTEM_WCTYPE */
/* Maximum number of character classes that can occur in a negated bracket
expression. */
#define MAX_NEG_CLASSES 64
/* Maximum length of character class names. */
#define MAX_CLASS_NAME
#define REST(re) (int)(ctx->re_end - (re)), (re)
static reg_errcode_t
tre_parse_bracket_items(tre_parse_ctx_t *ctx, int negate,
tre_ctype_t neg_classes[], int *num_neg_classes,
tre_ast_node_t ***items, int *num_items,
int *items_size)
{
const tre_char_t *re = ctx->re;
reg_errcode_t status = REG_OK;
tre_ctype_t class = (tre_ctype_t)0;
int i = *num_items;
int max_i = *items_size;
int skip;
/* Build an array of the items in the bracket expression. */
while (status == REG_OK)
{
skip = 0;
if (re == ctx->re_end)
{
status = REG_EBRACK;
}
else if (*re == CHAR_RBRACKET && re > ctx->re)
{
DPRINT(("tre_parse_bracket: done: '%.*" STRF "'\n", REST(re)));
re++;
break;
}
else
{
tre_cint_t min = 0, max = 0;
class = (tre_ctype_t)0;
if (re + 2 < ctx->re_end
&& *(re + 1) == CHAR_MINUS && *(re + 2) != CHAR_RBRACKET)
{
DPRINT(("tre_parse_bracket: range: '%.*" STRF "'\n", REST(re)));
min = *re;
max = *(re + 2);
re += 3;
/* XXX - Should use collation order instead of encoding values
in character ranges. */
if (min > max)
status = REG_ERANGE;
}
else if (re + 1 < ctx->re_end
&& *re == CHAR_LBRACKET && *(re + 1) == CHAR_PERIOD)
status = REG_ECOLLATE;
else if (re + 1 < ctx->re_end
&& *re == CHAR_LBRACKET && *(re + 1) == CHAR_EQUAL)
status = REG_ECOLLATE;
else if (re + 1 < ctx->re_end
&& *re == CHAR_LBRACKET && *(re + 1) == CHAR_COLON)
{
char tmp_str[64];
const tre_char_t *endptr = re + 2;
int len;
DPRINT(("tre_parse_bracket: class: '%.*" STRF "'\n", REST(re)));
while (endptr < ctx->re_end && *endptr != CHAR_COLON)
endptr++;
if (endptr != ctx->re_end)
{
len = MIN(endptr - re - 2, 63);
#ifdef TRE_WCHAR
{
tre_char_t tmp_wcs[64];
wcsncpy(tmp_wcs, re + 2, (size_t)len);
tmp_wcs[len] = L'\0';
#if defined HAVE_WCSRTOMBS
{
mbstate_t state;
const tre_char_t *src = tmp_wcs;
memset(&state, '\0', sizeof(state));
len = wcsrtombs(tmp_str, &src, sizeof(tmp_str), &state);
}
#elif defined HAVE_WCSTOMBS
len = wcstombs(tmp_str, tmp_wcs, 63);
#endif /* defined HAVE_WCSTOMBS */
}
#else /* !TRE_WCHAR */
strncpy(tmp_str, (const char*)re + 2, len);
#endif /* !TRE_WCHAR */
tmp_str[len] = '\0';
DPRINT((" class name: %s\n", tmp_str));
class = tre_ctype(tmp_str);
if (!class)
status = REG_ECTYPE;
/* Optimize character classes for 8 bit character sets. */
if (status == REG_OK && ctx->cur_max == 1)
{
status = tre_expand_ctype(ctx->mem, class, items,
&i, &max_i, ctx->cflags);
class = (tre_ctype_t)0;
skip = 1;
}
re = endptr + 2;
}
else
status = REG_ECTYPE;
min = 0;
max = TRE_CHAR_MAX;
}
else
{
DPRINT(("tre_parse_bracket: char: '%.*" STRF "'\n", REST(re)));
if (*re == CHAR_MINUS && *(re + 1) != CHAR_RBRACKET
&& ctx->re != re)
/* Two ranges are not allowed to share and endpoint. */
status = REG_ERANGE;
min = max = *re++;
}
if (status != REG_OK)
break;
if (class && negate)
if (*num_neg_classes >= MAX_NEG_CLASSES)
status = REG_ESPACE;
else
neg_classes[(*num_neg_classes)++] = class;
else if (!skip)
{
status = tre_new_item(ctx->mem, min, max, &i, &max_i, items);
if (status != REG_OK)
break;
((tre_literal_t*)((*items)[i-1])->obj)->u.class = class;
}
/* Add opposite-case counterpoints if REG_ICASE is present.
This is broken if there are more than two "same" characters. */
if (ctx->cflags & REG_ICASE && !class && status == REG_OK && !skip)
{
tre_cint_t cmin, ccurr;
DPRINT(("adding opposite-case counterpoints\n"));
while (min <= max)
{
if (tre_islower(min))
{
cmin = ccurr = tre_toupper(min++);
while (tre_islower(min) && tre_toupper(min) == ccurr + 1
&& min <= max)
ccurr = tre_toupper(min++);
status = tre_new_item(ctx->mem, cmin, ccurr,
&i, &max_i, items);
}
else if (tre_isupper(min))
{
cmin = ccurr = tre_tolower(min++);
while (tre_isupper(min) && tre_tolower(min) == ccurr + 1
&& min <= max)
ccurr = tre_tolower(min++);
status = tre_new_item(ctx->mem, cmin, ccurr,
&i, &max_i, items);
}
else min++;
if (status != REG_OK)
break;
}
if (status != REG_OK)
break;
}
}
}
*num_items = i;
*items_size = max_i;
ctx->re = re;
return status;
}
static reg_errcode_t
tre_parse_bracket(tre_parse_ctx_t *ctx, tre_ast_node_t **result)
{
tre_ast_node_t *node = NULL;
int negate = 0;
reg_errcode_t status = REG_OK;
tre_ast_node_t **items, *u, *n;
int i = 0, j, max_i = 32, curr_max, curr_min;
tre_ctype_t neg_classes[MAX_NEG_CLASSES];
int num_neg_classes = 0;
/* Start off with an array of `max_i' elements. */
items = xmalloc(sizeof(*items) * max_i);
if (items == NULL)
return REG_ESPACE;
if (*ctx->re == CHAR_CARET)
{
DPRINT(("tre_parse_bracket: negate: '%.*" STRF "'\n", REST(ctx->re)));
negate = 1;
ctx->re++;
}
status = tre_parse_bracket_items(ctx, negate, neg_classes, &num_neg_classes,
&items, &i, &max_i);
if (status != REG_OK)
goto parse_bracket_done;
/* Sort the array if we need to negate it. */
if (negate)
qsort(items, (unsigned)i, sizeof(*items), tre_compare_items);
curr_max = curr_min = 0;
/* Build a union of the items in the array, negated if necessary. */
for (j = 0; j < i && status == REG_OK; j++)
{
int min, max;
tre_literal_t *l = items[j]->obj;
min = l->code_min;
max = l->code_max;
DPRINT(("item: %d - %d, class %ld, curr_max = %d\n",
(int)l->code_min, (int)l->code_max, (long)l->u.class, curr_max));
if (negate)
{
if (min < curr_max)
{
/* Overlap. */
curr_max = MAX(max + 1, curr_max);
DPRINT(("overlap, curr_max = %d\n", curr_max));
l = NULL;
}
else
{
/* No overlap. */
curr_max = min - 1;
if (curr_max >= curr_min)
{
DPRINT(("no overlap\n"));
l->code_min = curr_min;
l->code_max = curr_max;
}
else
{
DPRINT(("no overlap, zero room\n"));
l = NULL;
}
curr_min = curr_max = max + 1;
}
}
if (l != NULL)
{
int k;
DPRINT(("creating %d - %d\n", (int)l->code_min, (int)l->code_max));
l->position = ctx->position;
if (num_neg_classes > 0)
{
l->neg_classes = tre_mem_alloc(ctx->mem,
(sizeof(l->neg_classes)
* (num_neg_classes + 1)));
if (l->neg_classes == NULL)
{
status = REG_ESPACE;
break;
}
for (k = 0; k < num_neg_classes; k++)
l->neg_classes[k] = neg_classes[k];
l->neg_classes[k] = (tre_ctype_t)0;
}
else
l->neg_classes = NULL;
if (node == NULL)
node = items[j];
else
{
u = tre_ast_new_union(ctx->mem, node, items[j]);
if (u == NULL)
status = REG_ESPACE;
node = u;
}
}
}
if (status != REG_OK)
goto parse_bracket_done;
if (negate)
{
int k;
DPRINT(("final: creating %d - %d\n", curr_min, (int)TRE_CHAR_MAX));
n = tre_ast_new_literal(ctx->mem, curr_min, TRE_CHAR_MAX, ctx->position);
if (n == NULL)
status = REG_ESPACE;
else
{
tre_literal_t *l = n->obj;
if (num_neg_classes > 0)
{
l->neg_classes = tre_mem_alloc(ctx->mem,
(sizeof(l->neg_classes)
* (num_neg_classes + 1)));
if (l->neg_classes == NULL)
{
status = REG_ESPACE;
goto parse_bracket_done;
}
for (k = 0; k < num_neg_classes; k++)
l->neg_classes[k] = neg_classes[k];
l->neg_classes[k] = (tre_ctype_t)0;
}
else
l->neg_classes = NULL;
if (node == NULL)
node = n;
else
{
u = tre_ast_new_union(ctx->mem, node, n);
if (u == NULL)
status = REG_ESPACE;
node = u;
}
}
}
if (status != REG_OK)
goto parse_bracket_done;
#ifdef TRE_DEBUG
tre_ast_print(node);
#endif /* TRE_DEBUG */
parse_bracket_done:
xfree(items);
ctx->position++;
*result = node;
return status;
}
/* Parses a positive decimal integer. Returns -1 if the string does not
contain a valid number. */
static int
tre_parse_int(const tre_char_t **regex, const tre_char_t *regex_end)
{
int num = -1;
const tre_char_t *r = *regex;
while (r < regex_end && *r >= L'0' && *r <= L'9')
{
if (num < 0)
num = 0;
num = num * 10 + *r - L'0';
r++;
}
*regex = r;
return num;
}
static reg_errcode_t
tre_parse_bound(tre_parse_ctx_t *ctx, tre_ast_node_t **result)
{
int min, max, i;
int cost_ins, cost_del, cost_subst, cost_max;
int limit_ins, limit_del, limit_subst, limit_err;
const tre_char_t *r = ctx->re;
const tre_char_t *start;
int minimal = (ctx->cflags & REG_UNGREEDY) ? 1 : 0;
int approx = 0;
int costs_set = 0;
int counts_set = 0;
cost_ins = cost_del = cost_subst = cost_max = TRE_PARAM_UNSET;
limit_ins = limit_del = limit_subst = limit_err = TRE_PARAM_UNSET;
/* Parse number (minimum repetition count). */
min = -1;
if (r < ctx->re_end && *r >= L'0' && *r <= L'9') {
DPRINT(("tre_parse: min count: '%.*" STRF "'\n", REST(r)));
min = tre_parse_int(&r, ctx->re_end);
}
/* Parse comma and second number (maximum repetition count). */
max = min;
if (r < ctx->re_end && *r == CHAR_COMMA)
{
r++;
DPRINT(("tre_parse: max count: '%.*" STRF "'\n", REST(r)));
max = tre_parse_int(&r, ctx->re_end);
}
/* Check that the repeat counts are sane. */
if ((max >= 0 && min > max) || max > RE_DUP_MAX)
return REG_BADBR;
/*
'{'
optionally followed immediately by a number == minimum repcount
optionally followed by , then a number == maximum repcount
+ then a number == maximum insertion count
- then a number == maximum deletion count
# then a number == maximum substitution count
~ then a number == maximum number of errors
Any of +, -, # or ~ without followed by a number means that
the maximum count/number of errors is infinite.
An equation of the form
Xi + Yd + Zs < C
can be specified to set costs and the cost limit to a value
different from the default value:
- X is the cost of an insertion
- Y is the cost of a deletion
- Z is the cost of a substitution
- C is the maximum cost
If no count limit or cost is set for an operation, the operation
is not allowed at all.
*/
do {
int done;
start = r;
/* Parse count limit settings */
done = 0;
if (!counts_set)
while (r + 1 < ctx->re_end && !done)
{
switch (*r)
{
case CHAR_PLUS: /* Insert limit */
DPRINT(("tre_parse: ins limit: '%.*" STRF "'\n", REST(r)));
r++;
limit_ins = tre_parse_int(&r, ctx->re_end);
if (limit_ins < 0)
limit_ins = INT_MAX;
counts_set = 1;
break;
case CHAR_MINUS: /* Delete limit */
DPRINT(("tre_parse: del limit: '%.*" STRF "'\n", REST(r)));
r++;
limit_del = tre_parse_int(&r, ctx->re_end);
if (limit_del < 0)
limit_del = INT_MAX;
counts_set = 1;
break;
case CHAR_HASH: /* Substitute limit */
DPRINT(("tre_parse: subst limit: '%.*" STRF "'\n", REST(r)));
r++;
limit_subst = tre_parse_int(&r, ctx->re_end);
if (limit_subst < 0)
limit_subst = INT_MAX;
counts_set = 1;
break;
case CHAR_TILDE: /* Maximum number of changes */
DPRINT(("tre_parse: count limit: '%.*" STRF "'\n", REST(r)));
r++;
limit_err = tre_parse_int(&r, ctx->re_end);
if (limit_err < 0)
limit_err = INT_MAX;
approx = 1;
break;
case CHAR_COMMA:
r++;
break;
case L' ':
r++;
break;
case L'}':
done = 1;
break;
default:
done = 1;
break;
}
}
/* Parse cost restriction equation. */
done = 0;
if (!costs_set)
while (r + 1 < ctx->re_end && !done)
{
switch (*r)
{
case CHAR_PLUS:
case L' ':
r++;
break;
case L'<':
DPRINT(("tre_parse: max cost: '%.*" STRF "'\n", REST(r)));
r++;
while (*r == L' ')
r++;
cost_max = tre_parse_int(&r, ctx->re_end);
if (cost_max < 0)
cost_max = INT_MAX;
else
cost_max--;
approx = 1;
break;
case CHAR_COMMA:
r++;
done = 1;
break;
default:
if (*r >= L'0' && *r <= L'9')
{
#ifdef TRE_DEBUG
const tre_char_t *sr = r;
#endif /* TRE_DEBUG */
int cost = tre_parse_int(&r, ctx->re_end);
/* XXX - make sure r is not past end. */
switch (*r)
{
case L'i': /* Insert cost */
DPRINT(("tre_parse: ins cost: '%.*" STRF "'\n",
REST(sr)));
r++;
cost_ins = cost;
costs_set = 1;
break;
case L'd': /* Delete cost */
DPRINT(("tre_parse: del cost: '%.*" STRF "'\n",
REST(sr)));
r++;
cost_del = cost;
costs_set = 1;
break;
case L's': /* Substitute cost */
DPRINT(("tre_parse: subst cost: '%.*" STRF "'\n",
REST(sr)));
r++;
cost_subst = cost;
costs_set = 1;
break;
default:
return REG_BADBR;
}
}
else
{
done = 1;
break;
}
}
}
} while (start != r);
/* Missing }. */
if (r >= ctx->re_end)
return REG_EBRACE;
/* Empty contents of {}. */
if (r == ctx->re)
return REG_BADBR;
/* Parse the ending '}' or '\}'.*/
if (ctx->cflags & REG_EXTENDED)
{
if (r >= ctx->re_end || *r != CHAR_RBRACE)
return REG_BADBR;
r++;
}
else
{
if (r + 1 >= ctx->re_end
|| *r != CHAR_BACKSLASH
|| *(r + 1) != CHAR_RBRACE)
return REG_BADBR;
r += 2;
}
/* Parse trailing '?' marking minimal repetition. */
if (r < ctx->re_end)
{
if (*r == CHAR_QUESTIONMARK)
{
minimal = !(ctx->cflags & REG_UNGREEDY);
r++;
}
else if (*r == CHAR_STAR || *r == CHAR_PLUS)
{
/* These are reserved for future extensions. */
return REG_BADRPT;
}
}
/* Create the AST node(s). */
if (min == 0 && max == 0)
{
*result = tre_ast_new_literal(ctx->mem, EMPTY, -1, -1);
if (*result == NULL)
return REG_ESPACE;
}
else
{
if (min < 0 && max < 0)
/* Only approximate parameters set, no repetitions. */
min = max = 1;
*result = tre_ast_new_iter(ctx->mem, *result, min, max, minimal);
if (!*result)
return REG_ESPACE;
/* If approximate matching parameters are set, add them to the
iteration node. */
if (approx || costs_set || counts_set)
{
int *params;
tre_iteration_t *iter = (*result)->obj;
if (costs_set || counts_set)
{
if (limit_ins == TRE_PARAM_UNSET)
{
if (cost_ins == TRE_PARAM_UNSET)
limit_ins = 0;
else
limit_ins = INT_MAX;
}
if (limit_del == TRE_PARAM_UNSET)
{
if (cost_del == TRE_PARAM_UNSET)
limit_del = 0;
else
limit_del = INT_MAX;
}
if (limit_subst == TRE_PARAM_UNSET)
{
if (cost_subst == TRE_PARAM_UNSET)
limit_subst = 0;
else
limit_subst = INT_MAX;
}
}
if (cost_max == TRE_PARAM_UNSET)
cost_max = INT_MAX;
if (limit_err == TRE_PARAM_UNSET)
limit_err = INT_MAX;
ctx->have_approx = 1;
params = tre_mem_alloc(ctx->mem, sizeof(*params) * TRE_PARAM_LAST);
if (!params)
return REG_ESPACE;
for (i = 0; i < TRE_PARAM_LAST; i++)
params[i] = TRE_PARAM_UNSET;
params[TRE_PARAM_COST_INS] = cost_ins;
params[TRE_PARAM_COST_DEL] = cost_del;
params[TRE_PARAM_COST_SUBST] = cost_subst;
params[TRE_PARAM_COST_MAX] = cost_max;
params[TRE_PARAM_MAX_INS] = limit_ins;
params[TRE_PARAM_MAX_DEL] = limit_del;
params[TRE_PARAM_MAX_SUBST] = limit_subst;
params[TRE_PARAM_MAX_ERR] = limit_err;
iter->params = params;
}
}
DPRINT(("tre_parse_bound: min %d, max %d, costs [%d,%d,%d, total %d], "
"limits [%d,%d,%d, total %d]\n",
min, max, cost_ins, cost_del, cost_subst, cost_max,
limit_ins, limit_del, limit_subst, limit_err));
ctx->re = r;
return REG_OK;
}
typedef enum {
PARSE_RE = 0,
PARSE_ATOM,
PARSE_MARK_FOR_SUBMATCH,
PARSE_BRANCH,
PARSE_PIECE,
PARSE_CATENATION,
PARSE_POST_CATENATION,
PARSE_UNION,
PARSE_POST_UNION,
PARSE_POSTFIX,
PARSE_RESTORE_CFLAGS
} tre_parse_re_stack_symbol_t;
reg_errcode_t
tre_parse(tre_parse_ctx_t *ctx)
{
tre_ast_node_t *result = NULL;
tre_parse_re_stack_symbol_t symbol;
reg_errcode_t status = REG_OK;
tre_stack_t *stack = ctx->stack;
int bottom = tre_stack_num_objects(stack);
int depth = 0;
int temporary_cflags = 0;
DPRINT(("tre_parse: parsing '%.*" STRF "', len = %d\n",
ctx->len, ctx->re, ctx->len));
if (!ctx->nofirstsub)
{
STACK_PUSH(stack, int, ctx->submatch_id);
STACK_PUSH(stack, int, PARSE_MARK_FOR_SUBMATCH);
ctx->submatch_id++;
}
STACK_PUSH(stack, int, PARSE_RE);
ctx->re_start = ctx->re;
ctx->re_end = ctx->re + ctx->len;
/* The following is basically just a recursive descent parser. I use
an explicit stack instead of recursive functions mostly because of
two reasons: compatibility with systems which have an overflowable
call stack, and efficiency (both in lines of code and speed). */
while (tre_stack_num_objects(stack) > bottom && status == REG_OK)
{
if (status != REG_OK)
break;
symbol = tre_stack_pop_int(stack);
switch (symbol)
{
case PARSE_RE:
/* Parse a full regexp. A regexp is one or more branches,
separated by the union operator `|'. */
#ifdef REG_LITERAL
if (!(ctx->cflags & REG_LITERAL)
&& ctx->cflags & REG_EXTENDED)
#endif /* REG_LITERAL */
STACK_PUSHX(stack, int, PARSE_UNION);
STACK_PUSHX(stack, int, PARSE_BRANCH);
break;
case PARSE_BRANCH:
/* Parse a branch. A branch is one or more pieces, concatenated.
A piece is an atom possibly followed by a postfix operator. */
STACK_PUSHX(stack, int, PARSE_CATENATION);
STACK_PUSHX(stack, int, PARSE_PIECE);
break;
case PARSE_PIECE:
/* Parse a piece. A piece is an atom possibly followed by one
or more postfix operators. */
#ifdef REG_LITERAL
if (!(ctx->cflags & REG_LITERAL))
#endif /* REG_LITERAL */
STACK_PUSHX(stack, int, PARSE_POSTFIX);
STACK_PUSHX(stack, int, PARSE_ATOM);
break;
case PARSE_CATENATION:
/* If the expression has not ended, parse another piece. */
{
tre_char_t c;
if (ctx->re >= ctx->re_end)
break;
c = *ctx->re;
#ifdef REG_LITERAL
if (!(ctx->cflags & REG_LITERAL))