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cpython/Modules/sre_lib.h

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/*
* Secret Labs' Regular Expression Engine
*
* regular expression matching engine
*
* Copyright (c) 1997-2001 by Secret Labs AB. All rights reserved.
*
* See the _sre.c file for information on usage and redistribution.
*/
/* String matching engine */
/* This file is included three times, with different character settings */
LOCAL(int)
SRE(at)(SRE_STATE* state, SRE_CHAR* ptr, SRE_CODE at)
{
/* check if pointer is at given position */
Py_ssize_t thisp, thatp;
switch (at) {
case SRE_AT_BEGINNING:
case SRE_AT_BEGINNING_STRING:
return ((void*) ptr == state->beginning);
case SRE_AT_BEGINNING_LINE:
return ((void*) ptr == state->beginning ||
SRE_IS_LINEBREAK((int) ptr[-1]));
case SRE_AT_END:
return (((void*) (ptr+1) == state->end &&
SRE_IS_LINEBREAK((int) ptr[0])) ||
((void*) ptr == state->end));
case SRE_AT_END_LINE:
return ((void*) ptr == state->end ||
SRE_IS_LINEBREAK((int) ptr[0]));
case SRE_AT_END_STRING:
return ((void*) ptr == state->end);
case SRE_AT_BOUNDARY:
if (state->beginning == state->end)
return 0;
thatp = ((void*) ptr > state->beginning) ?
SRE_IS_WORD((int) ptr[-1]) : 0;
thisp = ((void*) ptr < state->end) ?
SRE_IS_WORD((int) ptr[0]) : 0;
return thisp != thatp;
case SRE_AT_NON_BOUNDARY:
if (state->beginning == state->end)
return 0;
thatp = ((void*) ptr > state->beginning) ?
SRE_IS_WORD((int) ptr[-1]) : 0;
thisp = ((void*) ptr < state->end) ?
SRE_IS_WORD((int) ptr[0]) : 0;
return thisp == thatp;
case SRE_AT_LOC_BOUNDARY:
if (state->beginning == state->end)
return 0;
thatp = ((void*) ptr > state->beginning) ?
SRE_LOC_IS_WORD((int) ptr[-1]) : 0;
thisp = ((void*) ptr < state->end) ?
SRE_LOC_IS_WORD((int) ptr[0]) : 0;
return thisp != thatp;
case SRE_AT_LOC_NON_BOUNDARY:
if (state->beginning == state->end)
return 0;
thatp = ((void*) ptr > state->beginning) ?
SRE_LOC_IS_WORD((int) ptr[-1]) : 0;
thisp = ((void*) ptr < state->end) ?
SRE_LOC_IS_WORD((int) ptr[0]) : 0;
return thisp == thatp;
case SRE_AT_UNI_BOUNDARY:
if (state->beginning == state->end)
return 0;
thatp = ((void*) ptr > state->beginning) ?
SRE_UNI_IS_WORD((int) ptr[-1]) : 0;
thisp = ((void*) ptr < state->end) ?
SRE_UNI_IS_WORD((int) ptr[0]) : 0;
return thisp != thatp;
case SRE_AT_UNI_NON_BOUNDARY:
if (state->beginning == state->end)
return 0;
thatp = ((void*) ptr > state->beginning) ?
SRE_UNI_IS_WORD((int) ptr[-1]) : 0;
thisp = ((void*) ptr < state->end) ?
SRE_UNI_IS_WORD((int) ptr[0]) : 0;
return thisp == thatp;
}
return 0;
}
LOCAL(int)
SRE(charset)(SRE_CODE* set, SRE_CODE ch)
{
/* check if character is a member of the given set */
int ok = 1;
for (;;) {
switch (*set++) {
case SRE_OP_FAILURE:
return !ok;
case SRE_OP_LITERAL:
/* <LITERAL> <code> */
if (ch == set[0])
return ok;
set++;
break;
case SRE_OP_CATEGORY:
/* <CATEGORY> <code> */
if (sre_category(set[0], (int) ch))
return ok;
set++;
break;
case SRE_OP_CHARSET:
/* <CHARSET> <bitmap> */
if (ch < 256 &&
(set[ch/SRE_CODE_BITS] & (1u << (ch & (SRE_CODE_BITS-1)))))
return ok;
set += 256/SRE_CODE_BITS;
break;
case SRE_OP_RANGE:
/* <RANGE> <lower> <upper> */
if (set[0] <= ch && ch <= set[1])
return ok;
set += 2;
break;
case SRE_OP_NEGATE:
ok = !ok;
break;
case SRE_OP_BIGCHARSET:
/* <BIGCHARSET> <blockcount> <256 blockindices> <blocks> */
{
Py_ssize_t count, block;
count = *(set++);
if (ch < 0x10000u)
block = ((unsigned char*)set)[ch >> 8];
else
block = -1;
set += 256/sizeof(SRE_CODE);
if (block >=0 &&
(set[(block * 256 + (ch & 255))/SRE_CODE_BITS] &
(1u << (ch & (SRE_CODE_BITS-1)))))
return ok;
set += count * (256/SRE_CODE_BITS);
break;
}
default:
/* internal error -- there's not much we can do about it
here, so let's just pretend it didn't match... */
return 0;
}
}
}
LOCAL(Py_ssize_t) SRE(match)(SRE_STATE* state, SRE_CODE* pattern);
LOCAL(Py_ssize_t)
SRE(count)(SRE_STATE* state, SRE_CODE* pattern, Py_ssize_t maxcount)
{
SRE_CODE chr;
SRE_CHAR c;
SRE_CHAR* ptr = (SRE_CHAR *)state->ptr;
SRE_CHAR* end = (SRE_CHAR *)state->end;
Py_ssize_t i;
/* adjust end */
if (maxcount < end - ptr && maxcount != SRE_MAXREPEAT)
end = ptr + maxcount;
switch (pattern[0]) {
case SRE_OP_IN:
/* repeated set */
TRACE(("|%p|%p|COUNT IN\n", pattern, ptr));
while (ptr < end && SRE(charset)(pattern + 2, *ptr))
ptr++;
break;
case SRE_OP_ANY:
/* repeated dot wildcard. */
TRACE(("|%p|%p|COUNT ANY\n", pattern, ptr));
while (ptr < end && !SRE_IS_LINEBREAK(*ptr))
ptr++;
break;
case SRE_OP_ANY_ALL:
/* repeated dot wildcard. skip to the end of the target
string, and backtrack from there */
TRACE(("|%p|%p|COUNT ANY_ALL\n", pattern, ptr));
ptr = end;
break;
case SRE_OP_LITERAL:
/* repeated literal */
chr = pattern[1];
TRACE(("|%p|%p|COUNT LITERAL %d\n", pattern, ptr, chr));
c = (SRE_CHAR) chr;
#if SIZEOF_SRE_CHAR < 4
if ((SRE_CODE) c != chr)
; /* literal can't match: doesn't fit in char width */
else
#endif
while (ptr < end && *ptr == c)
ptr++;
break;
case SRE_OP_LITERAL_IGNORE:
/* repeated literal */
chr = pattern[1];
TRACE(("|%p|%p|COUNT LITERAL_IGNORE %d\n", pattern, ptr, chr));
while (ptr < end && (SRE_CODE) state->lower(*ptr) == chr)
ptr++;
break;
case SRE_OP_NOT_LITERAL:
/* repeated non-literal */
chr = pattern[1];
TRACE(("|%p|%p|COUNT NOT_LITERAL %d\n", pattern, ptr, chr));
c = (SRE_CHAR) chr;
#if SIZEOF_SRE_CHAR < 4
if ((SRE_CODE) c != chr)
ptr = end; /* literal can't match: doesn't fit in char width */
else
#endif
while (ptr < end && *ptr != c)
ptr++;
break;
case SRE_OP_NOT_LITERAL_IGNORE:
/* repeated non-literal */
chr = pattern[1];
TRACE(("|%p|%p|COUNT NOT_LITERAL_IGNORE %d\n", pattern, ptr, chr));
while (ptr < end && (SRE_CODE) state->lower(*ptr) != chr)
ptr++;
break;
default:
/* repeated single character pattern */
TRACE(("|%p|%p|COUNT SUBPATTERN\n", pattern, ptr));
while ((SRE_CHAR*) state->ptr < end) {
i = SRE(match)(state, pattern);
if (i < 0)
return i;
if (!i)
break;
}
TRACE(("|%p|%p|COUNT %" PY_FORMAT_SIZE_T "d\n", pattern, ptr,
(SRE_CHAR*) state->ptr - ptr));
return (SRE_CHAR*) state->ptr - ptr;
}
TRACE(("|%p|%p|COUNT %" PY_FORMAT_SIZE_T "d\n", pattern, ptr,
ptr - (SRE_CHAR*) state->ptr));
return ptr - (SRE_CHAR*) state->ptr;
}
#if 0 /* not used in this release */
LOCAL(int)
SRE(info)(SRE_STATE* state, SRE_CODE* pattern)
{
/* check if an SRE_OP_INFO block matches at the current position.
returns the number of SRE_CODE objects to skip if successful, 0
if no match */
SRE_CHAR* end = (SRE_CHAR*) state->end;
SRE_CHAR* ptr = (SRE_CHAR*) state->ptr;
Py_ssize_t i;
/* check minimal length */
if (pattern[3] && end - ptr < pattern[3])
return 0;
/* check known prefix */
if (pattern[2] & SRE_INFO_PREFIX && pattern[5] > 1) {
/* <length> <skip> <prefix data> <overlap data> */
for (i = 0; i < pattern[5]; i++)
if ((SRE_CODE) ptr[i] != pattern[7 + i])
return 0;
return pattern[0] + 2 * pattern[6];
}
return pattern[0];
}
#endif
/* The macros below should be used to protect recursive SRE(match)()
* calls that *failed* and do *not* return immediately (IOW, those
* that will backtrack). Explaining:
*
* - Recursive SRE(match)() returned true: that's usually a success
* (besides atypical cases like ASSERT_NOT), therefore there's no
* reason to restore lastmark;
*
* - Recursive SRE(match)() returned false but the current SRE(match)()
* is returning to the caller: If the current SRE(match)() is the
* top function of the recursion, returning false will be a matching
* failure, and it doesn't matter where lastmark is pointing to.
* If it's *not* the top function, it will be a recursive SRE(match)()
* failure by itself, and the calling SRE(match)() will have to deal
* with the failure by the same rules explained here (it will restore
* lastmark by itself if necessary);
*
* - Recursive SRE(match)() returned false, and will continue the
* outside 'for' loop: must be protected when breaking, since the next
* OP could potentially depend on lastmark;
*
* - Recursive SRE(match)() returned false, and will be called again
* inside a local for/while loop: must be protected between each
* loop iteration, since the recursive SRE(match)() could do anything,
* and could potentially depend on lastmark.
*
* For more information, check the discussion at SF patch #712900.
*/
#define LASTMARK_SAVE() \
do { \
ctx->lastmark = state->lastmark; \
ctx->lastindex = state->lastindex; \
} while (0)
#define LASTMARK_RESTORE() \
do { \
state->lastmark = ctx->lastmark; \
state->lastindex = ctx->lastindex; \
} while (0)
#define RETURN_ERROR(i) do { return i; } while(0)
#define RETURN_FAILURE do { ret = 0; goto exit; } while(0)
#define RETURN_SUCCESS do { ret = 1; goto exit; } while(0)
#define RETURN_ON_ERROR(i) \
do { if (i < 0) RETURN_ERROR(i); } while (0)
#define RETURN_ON_SUCCESS(i) \
do { RETURN_ON_ERROR(i); if (i > 0) RETURN_SUCCESS; } while (0)
#define RETURN_ON_FAILURE(i) \
do { RETURN_ON_ERROR(i); if (i == 0) RETURN_FAILURE; } while (0)
#define SFY(x) #x
#define DATA_STACK_ALLOC(state, type, ptr) \
do { \
alloc_pos = state->data_stack_base; \
TRACE(("allocating %s in %" PY_FORMAT_SIZE_T "d " \
"(%" PY_FORMAT_SIZE_T "d)\n", \
SFY(type), alloc_pos, sizeof(type))); \
if (sizeof(type) > state->data_stack_size - alloc_pos) { \
int j = data_stack_grow(state, sizeof(type)); \
if (j < 0) return j; \
if (ctx_pos != -1) \
DATA_STACK_LOOKUP_AT(state, SRE(match_context), ctx, ctx_pos); \
} \
ptr = (type*)(state->data_stack+alloc_pos); \
state->data_stack_base += sizeof(type); \
} while (0)
#define DATA_STACK_LOOKUP_AT(state, type, ptr, pos) \
do { \
TRACE(("looking up %s at %" PY_FORMAT_SIZE_T "d\n", SFY(type), pos)); \
ptr = (type*)(state->data_stack+pos); \
} while (0)
#define DATA_STACK_PUSH(state, data, size) \
do { \
TRACE(("copy data in %p to %" PY_FORMAT_SIZE_T "d " \
"(%" PY_FORMAT_SIZE_T "d)\n", \
data, state->data_stack_base, size)); \
if (size > state->data_stack_size - state->data_stack_base) { \
int j = data_stack_grow(state, size); \
if (j < 0) return j; \
if (ctx_pos != -1) \
DATA_STACK_LOOKUP_AT(state, SRE(match_context), ctx, ctx_pos); \
} \
memcpy(state->data_stack+state->data_stack_base, data, size); \
state->data_stack_base += size; \
} while (0)
#define DATA_STACK_POP(state, data, size, discard) \
do { \
TRACE(("copy data to %p from %" PY_FORMAT_SIZE_T "d " \
"(%" PY_FORMAT_SIZE_T "d)\n", \
data, state->data_stack_base-size, size)); \
memcpy(data, state->data_stack+state->data_stack_base-size, size); \
if (discard) \
state->data_stack_base -= size; \
} while (0)
#define DATA_STACK_POP_DISCARD(state, size) \
do { \
TRACE(("discard data from %" PY_FORMAT_SIZE_T "d " \
"(%" PY_FORMAT_SIZE_T "d)\n", \
state->data_stack_base-size, size)); \
state->data_stack_base -= size; \
} while(0)
#define DATA_PUSH(x) \
DATA_STACK_PUSH(state, (x), sizeof(*(x)))
#define DATA_POP(x) \
DATA_STACK_POP(state, (x), sizeof(*(x)), 1)
#define DATA_POP_DISCARD(x) \
DATA_STACK_POP_DISCARD(state, sizeof(*(x)))
#define DATA_ALLOC(t,p) \
DATA_STACK_ALLOC(state, t, p)
#define DATA_LOOKUP_AT(t,p,pos) \
DATA_STACK_LOOKUP_AT(state,t,p,pos)
#define MARK_PUSH(lastmark) \
do if (lastmark > 0) { \
i = lastmark; /* ctx->lastmark may change if reallocated */ \
DATA_STACK_PUSH(state, state->mark, (i+1)*sizeof(void*)); \
} while (0)
#define MARK_POP(lastmark) \
do if (lastmark > 0) { \
DATA_STACK_POP(state, state->mark, (lastmark+1)*sizeof(void*), 1); \
} while (0)
#define MARK_POP_KEEP(lastmark) \
do if (lastmark > 0) { \
DATA_STACK_POP(state, state->mark, (lastmark+1)*sizeof(void*), 0); \
} while (0)
#define MARK_POP_DISCARD(lastmark) \
do if (lastmark > 0) { \
DATA_STACK_POP_DISCARD(state, (lastmark+1)*sizeof(void*)); \
} while (0)
#define JUMP_NONE 0
#define JUMP_MAX_UNTIL_1 1
#define JUMP_MAX_UNTIL_2 2
#define JUMP_MAX_UNTIL_3 3
#define JUMP_MIN_UNTIL_1 4
#define JUMP_MIN_UNTIL_2 5
#define JUMP_MIN_UNTIL_3 6
#define JUMP_REPEAT 7
#define JUMP_REPEAT_ONE_1 8
#define JUMP_REPEAT_ONE_2 9
#define JUMP_MIN_REPEAT_ONE 10
#define JUMP_BRANCH 11
#define JUMP_ASSERT 12
#define JUMP_ASSERT_NOT 13
#define DO_JUMP(jumpvalue, jumplabel, nextpattern) \
DATA_ALLOC(SRE(match_context), nextctx); \
nextctx->last_ctx_pos = ctx_pos; \
nextctx->jump = jumpvalue; \
nextctx->pattern = nextpattern; \
ctx_pos = alloc_pos; \
ctx = nextctx; \
goto entrance; \
jumplabel: \
while (0) /* gcc doesn't like labels at end of scopes */ \
typedef struct {
Py_ssize_t last_ctx_pos;
Py_ssize_t jump;
SRE_CHAR* ptr;
SRE_CODE* pattern;
Py_ssize_t count;
Py_ssize_t lastmark;
Py_ssize_t lastindex;
union {
SRE_CODE chr;
SRE_REPEAT* rep;
} u;
} SRE(match_context);
/* check if string matches the given pattern. returns <0 for
error, 0 for failure, and 1 for success */
LOCAL(Py_ssize_t)
SRE(match)(SRE_STATE* state, SRE_CODE* pattern)
{
SRE_CHAR* end = (SRE_CHAR *)state->end;
Py_ssize_t alloc_pos, ctx_pos = -1;
Py_ssize_t i, ret = 0;
Py_ssize_t jump;
unsigned int sigcount=0;
SRE(match_context)* ctx;
SRE(match_context)* nextctx;
TRACE(("|%p|%p|ENTER\n", pattern, state->ptr));
DATA_ALLOC(SRE(match_context), ctx);
ctx->last_ctx_pos = -1;
ctx->jump = JUMP_NONE;
ctx->pattern = pattern;
ctx_pos = alloc_pos;
entrance:
ctx->ptr = (SRE_CHAR *)state->ptr;
if (ctx->pattern[0] == SRE_OP_INFO) {
/* optimization info block */
/* <INFO> <1=skip> <2=flags> <3=min> ... */
if (ctx->pattern[3] && (Py_uintptr_t)(end - ctx->ptr) < ctx->pattern[3]) {
TRACE(("reject (got %" PY_FORMAT_SIZE_T "d chars, "
"need %" PY_FORMAT_SIZE_T "d)\n",
end - ctx->ptr, (Py_ssize_t) ctx->pattern[3]));
RETURN_FAILURE;
}
ctx->pattern += ctx->pattern[1] + 1;
}
for (;;) {
++sigcount;
if ((0 == (sigcount & 0xfff)) && PyErr_CheckSignals())
RETURN_ERROR(SRE_ERROR_INTERRUPTED);
switch (*ctx->pattern++) {
case SRE_OP_MARK:
/* set mark */
/* <MARK> <gid> */
TRACE(("|%p|%p|MARK %d\n", ctx->pattern,
ctx->ptr, ctx->pattern[0]));
i = ctx->pattern[0];
if (i & 1)
state->lastindex = i/2 + 1;
if (i > state->lastmark) {
/* state->lastmark is the highest valid index in the
state->mark array. If it is increased by more than 1,
the intervening marks must be set to NULL to signal
that these marks have not been encountered. */
Py_ssize_t j = state->lastmark + 1;
while (j < i)
state->mark[j++] = NULL;
state->lastmark = i;
}
state->mark[i] = ctx->ptr;
ctx->pattern++;
break;
case SRE_OP_LITERAL:
/* match literal string */
/* <LITERAL> <code> */
TRACE(("|%p|%p|LITERAL %d\n", ctx->pattern,
ctx->ptr, *ctx->pattern));
if (ctx->ptr >= end || (SRE_CODE) ctx->ptr[0] != ctx->pattern[0])
RETURN_FAILURE;
ctx->pattern++;
ctx->ptr++;
break;
case SRE_OP_NOT_LITERAL:
/* match anything that is not literal character */
/* <NOT_LITERAL> <code> */
TRACE(("|%p|%p|NOT_LITERAL %d\n", ctx->pattern,
ctx->ptr, *ctx->pattern));
if (ctx->ptr >= end || (SRE_CODE) ctx->ptr[0] == ctx->pattern[0])
RETURN_FAILURE;
ctx->pattern++;
ctx->ptr++;
break;
case SRE_OP_SUCCESS:
/* end of pattern */
TRACE(("|%p|%p|SUCCESS\n", ctx->pattern, ctx->ptr));
state->ptr = ctx->ptr;
RETURN_SUCCESS;
case SRE_OP_AT:
/* match at given position */
/* <AT> <code> */
TRACE(("|%p|%p|AT %d\n", ctx->pattern, ctx->ptr, *ctx->pattern));
if (!SRE(at)(state, ctx->ptr, *ctx->pattern))
RETURN_FAILURE;
ctx->pattern++;
break;
case SRE_OP_CATEGORY:
/* match at given category */
/* <CATEGORY> <code> */
TRACE(("|%p|%p|CATEGORY %d\n", ctx->pattern,
ctx->ptr, *ctx->pattern));
if (ctx->ptr >= end || !sre_category(ctx->pattern[0], ctx->ptr[0]))
RETURN_FAILURE;
ctx->pattern++;
ctx->ptr++;
break;
case SRE_OP_ANY:
/* match anything (except a newline) */
/* <ANY> */
TRACE(("|%p|%p|ANY\n", ctx->pattern, ctx->ptr));
if (ctx->ptr >= end || SRE_IS_LINEBREAK(ctx->ptr[0]))
RETURN_FAILURE;
ctx->ptr++;
break;
case SRE_OP_ANY_ALL:
/* match anything */
/* <ANY_ALL> */
TRACE(("|%p|%p|ANY_ALL\n", ctx->pattern, ctx->ptr));
if (ctx->ptr >= end)
RETURN_FAILURE;
ctx->ptr++;
break;
case SRE_OP_IN:
/* match set member (or non_member) */
/* <IN> <skip> <set> */
TRACE(("|%p|%p|IN\n", ctx->pattern, ctx->ptr));
if (ctx->ptr >= end || !SRE(charset)(ctx->pattern + 1, *ctx->ptr))
RETURN_FAILURE;
ctx->pattern += ctx->pattern[0];
ctx->ptr++;
break;
case SRE_OP_LITERAL_IGNORE:
TRACE(("|%p|%p|LITERAL_IGNORE %d\n",
ctx->pattern, ctx->ptr, ctx->pattern[0]));
if (ctx->ptr >= end ||
state->lower(*ctx->ptr) != state->lower(*ctx->pattern))
RETURN_FAILURE;
ctx->pattern++;
ctx->ptr++;
break;
case SRE_OP_NOT_LITERAL_IGNORE:
TRACE(("|%p|%p|NOT_LITERAL_IGNORE %d\n",
ctx->pattern, ctx->ptr, *ctx->pattern));
if (ctx->ptr >= end ||
state->lower(*ctx->ptr) == state->lower(*ctx->pattern))
RETURN_FAILURE;
ctx->pattern++;
ctx->ptr++;
break;
case SRE_OP_IN_IGNORE:
TRACE(("|%p|%p|IN_IGNORE\n", ctx->pattern, ctx->ptr));
if (ctx->ptr >= end
|| !SRE(charset)(ctx->pattern+1,
(SRE_CODE)state->lower(*ctx->ptr)))
RETURN_FAILURE;
ctx->pattern += ctx->pattern[0];
ctx->ptr++;
break;
case SRE_OP_JUMP:
case SRE_OP_INFO:
/* jump forward */
/* <JUMP> <offset> */
TRACE(("|%p|%p|JUMP %d\n", ctx->pattern,
ctx->ptr, ctx->pattern[0]));
ctx->pattern += ctx->pattern[0];
break;
case SRE_OP_BRANCH:
/* alternation */
/* <BRANCH> <0=skip> code <JUMP> ... <NULL> */
TRACE(("|%p|%p|BRANCH\n", ctx->pattern, ctx->ptr));
LASTMARK_SAVE();
ctx->u.rep = state->repeat;
if (ctx->u.rep)
MARK_PUSH(ctx->lastmark);
for (; ctx->pattern[0]; ctx->pattern += ctx->pattern[0]) {
if (ctx->pattern[1] == SRE_OP_LITERAL &&
(ctx->ptr >= end ||
(SRE_CODE) *ctx->ptr != ctx->pattern[2]))
continue;
if (ctx->pattern[1] == SRE_OP_IN &&
(ctx->ptr >= end ||
!SRE(charset)(ctx->pattern + 3, (SRE_CODE) *ctx->ptr)))
continue;
state->ptr = ctx->ptr;
DO_JUMP(JUMP_BRANCH, jump_branch, ctx->pattern+1);
if (ret) {
if (ctx->u.rep)
MARK_POP_DISCARD(ctx->lastmark);
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
if (ctx->u.rep)
MARK_POP_KEEP(ctx->lastmark);
LASTMARK_RESTORE();
}
if (ctx->u.rep)
MARK_POP_DISCARD(ctx->lastmark);
RETURN_FAILURE;
case SRE_OP_REPEAT_ONE:
/* match repeated sequence (maximizing regexp) */
/* this operator only works if the repeated item is
exactly one character wide, and we're not already
collecting backtracking points. for other cases,
use the MAX_REPEAT operator */
/* <REPEAT_ONE> <skip> <1=min> <2=max> item <SUCCESS> tail */
TRACE(("|%p|%p|REPEAT_ONE %d %d\n", ctx->pattern, ctx->ptr,
ctx->pattern[1], ctx->pattern[2]));
if ((Py_ssize_t) ctx->pattern[1] > end - ctx->ptr)
RETURN_FAILURE; /* cannot match */
state->ptr = ctx->ptr;
ret = SRE(count)(state, ctx->pattern+3, ctx->pattern[2]);
RETURN_ON_ERROR(ret);
DATA_LOOKUP_AT(SRE(match_context), ctx, ctx_pos);
ctx->count = ret;
ctx->ptr += ctx->count;
/* when we arrive here, count contains the number of
matches, and ctx->ptr points to the tail of the target
string. check if the rest of the pattern matches,
and backtrack if not. */
if (ctx->count < (Py_ssize_t) ctx->pattern[1])
RETURN_FAILURE;
if (ctx->pattern[ctx->pattern[0]] == SRE_OP_SUCCESS) {
/* tail is empty. we're finished */
state->ptr = ctx->ptr;
RETURN_SUCCESS;
}
LASTMARK_SAVE();
if (ctx->pattern[ctx->pattern[0]] == SRE_OP_LITERAL) {
/* tail starts with a literal. skip positions where
the rest of the pattern cannot possibly match */
ctx->u.chr = ctx->pattern[ctx->pattern[0]+1];
for (;;) {
while (ctx->count >= (Py_ssize_t) ctx->pattern[1] &&
(ctx->ptr >= end || *ctx->ptr != ctx->u.chr)) {
ctx->ptr--;
ctx->count--;
}
if (ctx->count < (Py_ssize_t) ctx->pattern[1])
break;
state->ptr = ctx->ptr;
DO_JUMP(JUMP_REPEAT_ONE_1, jump_repeat_one_1,
ctx->pattern+ctx->pattern[0]);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
LASTMARK_RESTORE();
ctx->ptr--;
ctx->count--;
}
} else {
/* general case */
while (ctx->count >= (Py_ssize_t) ctx->pattern[1]) {
state->ptr = ctx->ptr;
DO_JUMP(JUMP_REPEAT_ONE_2, jump_repeat_one_2,
ctx->pattern+ctx->pattern[0]);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
ctx->ptr--;
ctx->count--;
LASTMARK_RESTORE();
}
}
RETURN_FAILURE;
case SRE_OP_MIN_REPEAT_ONE:
/* match repeated sequence (minimizing regexp) */
/* this operator only works if the repeated item is
exactly one character wide, and we're not already
collecting backtracking points. for other cases,
use the MIN_REPEAT operator */
/* <MIN_REPEAT_ONE> <skip> <1=min> <2=max> item <SUCCESS> tail */
TRACE(("|%p|%p|MIN_REPEAT_ONE %d %d\n", ctx->pattern, ctx->ptr,
ctx->pattern[1], ctx->pattern[2]));
if ((Py_ssize_t) ctx->pattern[1] > end - ctx->ptr)
RETURN_FAILURE; /* cannot match */
state->ptr = ctx->ptr;
if (ctx->pattern[1] == 0)
ctx->count = 0;
else {
/* count using pattern min as the maximum */
ret = SRE(count)(state, ctx->pattern+3, ctx->pattern[1]);
RETURN_ON_ERROR(ret);
DATA_LOOKUP_AT(SRE(match_context), ctx, ctx_pos);
if (ret < (Py_ssize_t) ctx->pattern[1])
/* didn't match minimum number of times */
RETURN_FAILURE;
/* advance past minimum matches of repeat */
ctx->count = ret;
ctx->ptr += ctx->count;
}
if (ctx->pattern[ctx->pattern[0]] == SRE_OP_SUCCESS) {
/* tail is empty. we're finished */
state->ptr = ctx->ptr;
RETURN_SUCCESS;
} else {
/* general case */
LASTMARK_SAVE();
while ((Py_ssize_t)ctx->pattern[2] == SRE_MAXREPEAT
|| ctx->count <= (Py_ssize_t)ctx->pattern[2]) {
state->ptr = ctx->ptr;
DO_JUMP(JUMP_MIN_REPEAT_ONE,jump_min_repeat_one,
ctx->pattern+ctx->pattern[0]);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
state->ptr = ctx->ptr;
ret = SRE(count)(state, ctx->pattern+3, 1);
RETURN_ON_ERROR(ret);
DATA_LOOKUP_AT(SRE(match_context), ctx, ctx_pos);
if (ret == 0)
break;
assert(ret == 1);
ctx->ptr++;
ctx->count++;
LASTMARK_RESTORE();
}
}
RETURN_FAILURE;
case SRE_OP_REPEAT:
/* create repeat context. all the hard work is done
by the UNTIL operator (MAX_UNTIL, MIN_UNTIL) */
/* <REPEAT> <skip> <1=min> <2=max> item <UNTIL> tail */
TRACE(("|%p|%p|REPEAT %d %d\n", ctx->pattern, ctx->ptr,
ctx->pattern[1], ctx->pattern[2]));
/* install new repeat context */
ctx->u.rep = (SRE_REPEAT*) PyObject_MALLOC(sizeof(*ctx->u.rep));
if (!ctx->u.rep) {
PyErr_NoMemory();
RETURN_FAILURE;
}
ctx->u.rep->count = -1;
ctx->u.rep->pattern = ctx->pattern;
ctx->u.rep->prev = state->repeat;
ctx->u.rep->last_ptr = NULL;
state->repeat = ctx->u.rep;
state->ptr = ctx->ptr;
DO_JUMP(JUMP_REPEAT, jump_repeat, ctx->pattern+ctx->pattern[0]);
state->repeat = ctx->u.rep->prev;
PyObject_FREE(ctx->u.rep);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
RETURN_FAILURE;
case SRE_OP_MAX_UNTIL:
/* maximizing repeat */
/* <REPEAT> <skip> <1=min> <2=max> item <MAX_UNTIL> tail */
/* FIXME: we probably need to deal with zero-width
matches in here... */
ctx->u.rep = state->repeat;
if (!ctx->u.rep)
RETURN_ERROR(SRE_ERROR_STATE);
state->ptr = ctx->ptr;
ctx->count = ctx->u.rep->count+1;
TRACE(("|%p|%p|MAX_UNTIL %" PY_FORMAT_SIZE_T "d\n", ctx->pattern,
ctx->ptr, ctx->count));
if (ctx->count < (Py_ssize_t) ctx->u.rep->pattern[1]) {
/* not enough matches */
ctx->u.rep->count = ctx->count;
DO_JUMP(JUMP_MAX_UNTIL_1, jump_max_until_1,
ctx->u.rep->pattern+3);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
ctx->u.rep->count = ctx->count-1;
state->ptr = ctx->ptr;
RETURN_FAILURE;
}
if ((ctx->count < (Py_ssize_t) ctx->u.rep->pattern[2] ||
ctx->u.rep->pattern[2] == SRE_MAXREPEAT) &&
state->ptr != ctx->u.rep->last_ptr) {
/* we may have enough matches, but if we can
match another item, do so */
ctx->u.rep->count = ctx->count;
LASTMARK_SAVE();
MARK_PUSH(ctx->lastmark);
/* zero-width match protection */
DATA_PUSH(&ctx->u.rep->last_ptr);
ctx->u.rep->last_ptr = state->ptr;
DO_JUMP(JUMP_MAX_UNTIL_2, jump_max_until_2,
ctx->u.rep->pattern+3);
DATA_POP(&ctx->u.rep->last_ptr);
if (ret) {
MARK_POP_DISCARD(ctx->lastmark);
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
MARK_POP(ctx->lastmark);
LASTMARK_RESTORE();
ctx->u.rep->count = ctx->count-1;
state->ptr = ctx->ptr;
}
/* cannot match more repeated items here. make sure the
tail matches */
state->repeat = ctx->u.rep->prev;
DO_JUMP(JUMP_MAX_UNTIL_3, jump_max_until_3, ctx->pattern);
RETURN_ON_SUCCESS(ret);
state->repeat = ctx->u.rep;
state->ptr = ctx->ptr;
RETURN_FAILURE;
case SRE_OP_MIN_UNTIL:
/* minimizing repeat */
/* <REPEAT> <skip> <1=min> <2=max> item <MIN_UNTIL> tail */
ctx->u.rep = state->repeat;
if (!ctx->u.rep)
RETURN_ERROR(SRE_ERROR_STATE);
state->ptr = ctx->ptr;
ctx->count = ctx->u.rep->count+1;
TRACE(("|%p|%p|MIN_UNTIL %" PY_FORMAT_SIZE_T "d %p\n", ctx->pattern,
ctx->ptr, ctx->count, ctx->u.rep->pattern));
if (ctx->count < (Py_ssize_t) ctx->u.rep->pattern[1]) {
/* not enough matches */
ctx->u.rep->count = ctx->count;
DO_JUMP(JUMP_MIN_UNTIL_1, jump_min_until_1,
ctx->u.rep->pattern+3);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
ctx->u.rep->count = ctx->count-1;
state->ptr = ctx->ptr;
RETURN_FAILURE;
}
LASTMARK_SAVE();
/* see if the tail matches */
state->repeat = ctx->u.rep->prev;
DO_JUMP(JUMP_MIN_UNTIL_2, jump_min_until_2, ctx->pattern);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
state->repeat = ctx->u.rep;
state->ptr = ctx->ptr;
LASTMARK_RESTORE();
if ((ctx->count >= (Py_ssize_t) ctx->u.rep->pattern[2]
&& ctx->u.rep->pattern[2] != SRE_MAXREPEAT) ||
state->ptr == ctx->u.rep->last_ptr)
RETURN_FAILURE;
ctx->u.rep->count = ctx->count;
/* zero-width match protection */
DATA_PUSH(&ctx->u.rep->last_ptr);
ctx->u.rep->last_ptr = state->ptr;
DO_JUMP(JUMP_MIN_UNTIL_3,jump_min_until_3,
ctx->u.rep->pattern+3);
DATA_POP(&ctx->u.rep->last_ptr);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_SUCCESS;
}
ctx->u.rep->count = ctx->count-1;
state->ptr = ctx->ptr;
RETURN_FAILURE;
case SRE_OP_GROUPREF:
/* match backreference */
TRACE(("|%p|%p|GROUPREF %d\n", ctx->pattern,
ctx->ptr, ctx->pattern[0]));
i = ctx->pattern[0];
{
Py_ssize_t groupref = i+i;
if (groupref >= state->lastmark) {
RETURN_FAILURE;
} else {
SRE_CHAR* p = (SRE_CHAR*) state->mark[groupref];
SRE_CHAR* e = (SRE_CHAR*) state->mark[groupref+1];
if (!p || !e || e < p)
RETURN_FAILURE;
while (p < e) {
if (ctx->ptr >= end || *ctx->ptr != *p)
RETURN_FAILURE;
p++;
ctx->ptr++;
}
}
}
ctx->pattern++;
break;
case SRE_OP_GROUPREF_IGNORE:
/* match backreference */
TRACE(("|%p|%p|GROUPREF_IGNORE %d\n", ctx->pattern,
ctx->ptr, ctx->pattern[0]));
i = ctx->pattern[0];
{
Py_ssize_t groupref = i+i;
if (groupref >= state->lastmark) {
RETURN_FAILURE;
} else {
SRE_CHAR* p = (SRE_CHAR*) state->mark[groupref];
SRE_CHAR* e = (SRE_CHAR*) state->mark[groupref+1];
if (!p || !e || e < p)
RETURN_FAILURE;
while (p < e) {
if (ctx->ptr >= end ||
state->lower(*ctx->ptr) != state->lower(*p))
RETURN_FAILURE;
p++;
ctx->ptr++;
}
}
}
ctx->pattern++;
break;
case SRE_OP_GROUPREF_EXISTS:
TRACE(("|%p|%p|GROUPREF_EXISTS %d\n", ctx->pattern,
ctx->ptr, ctx->pattern[0]));
/* <GROUPREF_EXISTS> <group> <skip> codeyes <JUMP> codeno ... */
i = ctx->pattern[0];
{
Py_ssize_t groupref = i+i;
if (groupref >= state->lastmark) {
ctx->pattern += ctx->pattern[1];
break;
} else {
SRE_CHAR* p = (SRE_CHAR*) state->mark[groupref];
SRE_CHAR* e = (SRE_CHAR*) state->mark[groupref+1];
if (!p || !e || e < p) {
ctx->pattern += ctx->pattern[1];
break;
}
}
}
ctx->pattern += 2;
break;
case SRE_OP_ASSERT:
/* assert subpattern */
/* <ASSERT> <skip> <back> <pattern> */
TRACE(("|%p|%p|ASSERT %d\n", ctx->pattern,
ctx->ptr, ctx->pattern[1]));
state->ptr = ctx->ptr - ctx->pattern[1];
if (state->ptr < state->beginning)
RETURN_FAILURE;
DO_JUMP(JUMP_ASSERT, jump_assert, ctx->pattern+2);
RETURN_ON_FAILURE(ret);
ctx->pattern += ctx->pattern[0];
break;
case SRE_OP_ASSERT_NOT:
/* assert not subpattern */
/* <ASSERT_NOT> <skip> <back> <pattern> */
TRACE(("|%p|%p|ASSERT_NOT %d\n", ctx->pattern,
ctx->ptr, ctx->pattern[1]));
state->ptr = ctx->ptr - ctx->pattern[1];
if (state->ptr >= state->beginning) {
DO_JUMP(JUMP_ASSERT_NOT, jump_assert_not, ctx->pattern+2);
if (ret) {
RETURN_ON_ERROR(ret);
RETURN_FAILURE;
}
}
ctx->pattern += ctx->pattern[0];
break;
case SRE_OP_FAILURE:
/* immediate failure */
TRACE(("|%p|%p|FAILURE\n", ctx->pattern, ctx->ptr));
RETURN_FAILURE;
default:
TRACE(("|%p|%p|UNKNOWN %d\n", ctx->pattern, ctx->ptr,
ctx->pattern[-1]));
RETURN_ERROR(SRE_ERROR_ILLEGAL);
}
}
exit:
ctx_pos = ctx->last_ctx_pos;
jump = ctx->jump;
DATA_POP_DISCARD(ctx);
if (ctx_pos == -1)
return ret;
DATA_LOOKUP_AT(SRE(match_context), ctx, ctx_pos);
switch (jump) {
case JUMP_MAX_UNTIL_2:
TRACE(("|%p|%p|JUMP_MAX_UNTIL_2\n", ctx->pattern, ctx->ptr));
goto jump_max_until_2;
case JUMP_MAX_UNTIL_3:
TRACE(("|%p|%p|JUMP_MAX_UNTIL_3\n", ctx->pattern, ctx->ptr));
goto jump_max_until_3;
case JUMP_MIN_UNTIL_2:
TRACE(("|%p|%p|JUMP_MIN_UNTIL_2\n", ctx->pattern, ctx->ptr));
goto jump_min_until_2;
case JUMP_MIN_UNTIL_3:
TRACE(("|%p|%p|JUMP_MIN_UNTIL_3\n", ctx->pattern, ctx->ptr));
goto jump_min_until_3;
case JUMP_BRANCH:
TRACE(("|%p|%p|JUMP_BRANCH\n", ctx->pattern, ctx->ptr));
goto jump_branch;
case JUMP_MAX_UNTIL_1:
TRACE(("|%p|%p|JUMP_MAX_UNTIL_1\n", ctx->pattern, ctx->ptr));
goto jump_max_until_1;
case JUMP_MIN_UNTIL_1:
TRACE(("|%p|%p|JUMP_MIN_UNTIL_1\n", ctx->pattern, ctx->ptr));
goto jump_min_until_1;
case JUMP_REPEAT:
TRACE(("|%p|%p|JUMP_REPEAT\n", ctx->pattern, ctx->ptr));
goto jump_repeat;
case JUMP_REPEAT_ONE_1:
TRACE(("|%p|%p|JUMP_REPEAT_ONE_1\n", ctx->pattern, ctx->ptr));
goto jump_repeat_one_1;
case JUMP_REPEAT_ONE_2:
TRACE(("|%p|%p|JUMP_REPEAT_ONE_2\n", ctx->pattern, ctx->ptr));
goto jump_repeat_one_2;
case JUMP_MIN_REPEAT_ONE:
TRACE(("|%p|%p|JUMP_MIN_REPEAT_ONE\n", ctx->pattern, ctx->ptr));
goto jump_min_repeat_one;
case JUMP_ASSERT:
TRACE(("|%p|%p|JUMP_ASSERT\n", ctx->pattern, ctx->ptr));
goto jump_assert;
case JUMP_ASSERT_NOT:
TRACE(("|%p|%p|JUMP_ASSERT_NOT\n", ctx->pattern, ctx->ptr));
goto jump_assert_not;
case JUMP_NONE:
TRACE(("|%p|%p|RETURN %" PY_FORMAT_SIZE_T "d\n", ctx->pattern,
ctx->ptr, ret));
break;
}
return ret; /* should never get here */
}
LOCAL(Py_ssize_t)
SRE(search)(SRE_STATE* state, SRE_CODE* pattern)
{
SRE_CHAR* ptr = (SRE_CHAR *)state->start;
SRE_CHAR* end = (SRE_CHAR *)state->end;
Py_ssize_t status = 0;
Py_ssize_t prefix_len = 0;
Py_ssize_t prefix_skip = 0;
SRE_CODE* prefix = NULL;
SRE_CODE* charset = NULL;
SRE_CODE* overlap = NULL;
int flags = 0;
if (pattern[0] == SRE_OP_INFO) {
/* optimization info block */
/* <INFO> <1=skip> <2=flags> <3=min> <4=max> <5=prefix info> */
flags = pattern[2];
if (pattern[3] > 1) {
/* adjust end point (but make sure we leave at least one
character in there, so literal search will work) */
end -= pattern[3] - 1;
if (end <= ptr)
end = ptr;
}
if (flags & SRE_INFO_PREFIX) {
/* pattern starts with a known prefix */
/* <length> <skip> <prefix data> <overlap data> */
prefix_len = pattern[5];
prefix_skip = pattern[6];
prefix = pattern + 7;
overlap = prefix + prefix_len - 1;
} else if (flags & SRE_INFO_CHARSET)
/* pattern starts with a character from a known set */
/* <charset> */
charset = pattern + 5;
pattern += 1 + pattern[1];
}
TRACE(("prefix = %p %" PY_FORMAT_SIZE_T "d %" PY_FORMAT_SIZE_T "d\n",
prefix, prefix_len, prefix_skip));
TRACE(("charset = %p\n", charset));
#if defined(USE_FAST_SEARCH)
if (prefix_len > 1) {
/* pattern starts with a known prefix. use the overlap
table to skip forward as fast as we possibly can */
Py_ssize_t i = 0;
end = (SRE_CHAR *)state->end;
if (prefix_len > end - ptr)
return 0;
#if SIZEOF_SRE_CHAR < 4
for (i = 0; i < prefix_len; i++)
if ((SRE_CODE)(SRE_CHAR) prefix[i] != prefix[i])
return 0; /* literal can't match: doesn't fit in char width */
#endif
while (ptr < end) {
SRE_CHAR c = (SRE_CHAR) prefix[0];
while (*ptr++ != c) {
if (ptr >= end)
return 0;
}
if (ptr >= end)
return 0;
i = 1;
do {
if (*ptr == (SRE_CHAR) prefix[i]) {
if (++i != prefix_len) {
if (++ptr >= end)
return 0;
continue;
}
/* found a potential match */
TRACE(("|%p|%p|SEARCH SCAN\n", pattern, ptr));
state->start = ptr - (prefix_len - 1);
state->ptr = ptr - (prefix_len - prefix_skip - 1);
if (flags & SRE_INFO_LITERAL)
return 1; /* we got all of it */
status = SRE(match)(state, pattern + 2*prefix_skip);
if (status != 0)
return status;
/* close but no cigar -- try again */
if (++ptr >= end)
return 0;
}
i = overlap[i];
} while (i != 0);
}
return 0;
}
#endif
if (pattern[0] == SRE_OP_LITERAL) {
/* pattern starts with a literal character. this is used
for short prefixes, and if fast search is disabled */
SRE_CHAR c = (SRE_CHAR) pattern[1];
#if SIZEOF_SRE_CHAR < 4
if ((SRE_CODE) c != pattern[1])
return 0; /* literal can't match: doesn't fit in char width */
#endif
end = (SRE_CHAR *)state->end;
while (ptr < end) {
while (*ptr != c) {
if (++ptr >= end)
return 0;
}
TRACE(("|%p|%p|SEARCH LITERAL\n", pattern, ptr));
state->start = ptr;
state->ptr = ++ptr;
if (flags & SRE_INFO_LITERAL)
return 1; /* we got all of it */
status = SRE(match)(state, pattern + 2);
if (status != 0)
break;
}
} else if (charset) {
/* pattern starts with a character from a known set */
end = (SRE_CHAR *)state->end;
for (;;) {
while (ptr < end && !SRE(charset)(charset, *ptr))
ptr++;
if (ptr >= end)
return 0;
TRACE(("|%p|%p|SEARCH CHARSET\n", pattern, ptr));
state->start = ptr;
state->ptr = ptr;
status = SRE(match)(state, pattern);
if (status != 0)
break;
ptr++;
}
} else
/* general case */
while (ptr <= end) {
TRACE(("|%p|%p|SEARCH\n", pattern, ptr));
state->start = state->ptr = ptr++;
status = SRE(match)(state, pattern);
if (status != 0)
break;
}
return status;
}
#undef SRE_CHAR
#undef SIZEOF_SRE_CHAR
#undef SRE
/* vim:ts=4:sw=4:et
*/
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