Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA. */
-/* BUGS:
- - (x?)*y\1z should match both xxxxyxz and xxxyz.
- TODO:
+/* TODO:
- structure the opcode space into opcode+flag.
- merge with glibc's regex.[ch].
- replace (succeed_n + jump_n + set_number_at) with something that doesn't
} \
} while (0)
-/* Discard a saved register off the stack. */
-#define DISCARD_FAILURE_REG_OR_COUNT() \
-do { \
- int reg = POP_FAILURE_INT (); \
- if (reg == -1) \
- { \
- /* It's a counter. */ \
- POP_FAILURE_POINTER (); \
- reg = POP_FAILURE_INT (); \
- DEBUG_PRINT3 (" Discard counter %p = %d\n", ptr, reg); \
- } \
- else \
- { \
- POP_FAILURE_POINTER (); \
- POP_FAILURE_POINTER (); \
- DEBUG_PRINT4 (" Discard reg %d (spanning %p -> %p)\n", \
- reg, regstart[reg], regend[reg]); \
- } \
-} while (0)
-
/* Check that we are not stuck in an infinite loop. */
#define CHECK_INFINITE_LOOP(pat_cur, string_place) \
do { \
&& FAILURE_PAT (failure) <= bufp->buffer + bufp->used); \
if (FAILURE_PAT (failure) == pat_cur) \
{ \
- while (fail_stack.frame < fail_stack.avail) \
- DISCARD_FAILURE_REG_OR_COUNT (); \
- goto fail; \
+ cycle = 1; \
+ break; \
} \
DEBUG_PRINT2 (" Other pattern: %p\n", FAILURE_PAT (failure)); \
failure = NEXT_FAILURE_HANDLE(failure); \
} \
DEBUG_PRINT2 (" Other string: %p\n", FAILURE_STR (failure)); \
} while (0)
-
+
/* Push the information about the state we will need
if we ever fail back to it.
/* But patterns can have more than `MAX_REGNUM' registers. We just
ignore the excess. */
-typedef unsigned regnum_t;
+typedef int regnum_t;
/* Macros for the compile stack. */
if (!RE_TRANSLATE_P (translate))
{
+ EXTEND_RANGE_TABLE (work_area, 2);
work_area->table[work_area->used++] = (start);
work_area->table[work_area->used++] = (end);
- return;
+ return -1;
}
eqv_table = XCHAR_TABLE (translate)->extras[2];
#endif /* emacs */
-/* We need to find the image of the range start..end when passed through
+/* Record the the image of the range start..end when passed through
TRANSLATE. This is not necessarily TRANSLATE(start)..TRANSLATE(end)
and is not even necessarily contiguous.
- We approximate it with the smallest contiguous range that contains
- all the chars we need. However, that is not good enough for Latin-1,
- so we do a better job in that case.
+ Normally we approximate it with the smallest contiguous range that contains
+ all the chars we need. However, for Latin-1 we go to extra effort
+ to do a better job.
+
+ This function is not called for ASCII ranges.
Returns -1 if successful, REG_ESPACE if ran out of space. */
#ifdef emacs
/* For Latin-1 ranges, use set_image_of_range_1
to get proper handling of ranges that include letters and nonletters.
- For ASCII, this is not necessary.
+ For a range that includes the whole of Latin-1, this is not necessary.
For other character sets, we don't bother to get this right. */
- if (start < 04400 && end > 0200)
+ if (RE_TRANSLATE_P (translate) && start < 04400
+ && !(start < 04200 && end >= 04377))
{
+ int newend;
int tem;
- tem = set_image_of_range_1 (work_area, start, end, translate);
+ newend = end;
+ if (newend > 04377)
+ newend = 04377;
+ tem = set_image_of_range_1 (work_area, start, newend, translate);
if (tem > 0)
return tem;
}
#endif
- cmin = TRANSLATE (start), cmax = TRANSLATE (end);
+ EXTEND_RANGE_TABLE (work_area, 2);
+ work_area->table[work_area->used++] = (start);
+ work_area->table[work_area->used++] = (end);
+
+ cmin = -1, cmax = -1;
if (RE_TRANSLATE_P (translate))
- for (; start <= end; start++)
- {
- re_wchar_t c = TRANSLATE (start);
- cmin = MIN (cmin, c);
- cmax = MAX (cmax, c);
- }
+ {
+ int ch;
- EXTEND_RANGE_TABLE (work_area, 2);
- work_area->table[work_area->used++] = (cmin);
- work_area->table[work_area->used++] = (cmax);
+ for (ch = start; ch <= end; ch++)
+ {
+ re_wchar_t c = TRANSLATE (ch);
+ if (! (start <= c && c <= end))
+ {
+ if (cmin == -1)
+ cmin = c, cmax = c;
+ else
+ {
+ cmin = MIN (cmin, c);
+ cmax = MAX (cmax, c);
+ }
+ }
+ }
+
+ if (cmin != -1)
+ {
+ EXTEND_RANGE_TABLE (work_area, 2);
+ work_area->table[work_area->used++] = (cmin);
+ work_area->table[work_area->used++] = (cmax);
+ }
+ }
return -1;
}
unsigned int startoffset = 0;
re_opcode_t ofj =
/* Check if the loop can match the empty string. */
- (simple || !analyse_first (laststart, b, NULL, 0)) ?
- on_failure_jump : on_failure_jump_loop;
+ (simple || !analyse_first (laststart, b, NULL, 0))
+ ? on_failure_jump : on_failure_jump_loop;
assert (skip_one_char (laststart) <= b);
if (!zero_times_ok && simple)
{
boolean emptyp = analyse_first (laststart, b, NULL, 0);
- /* The non-greedy multiple match looks like a repeat..until:
- we only need a conditional jump at the end of the loop */
+ /* The non-greedy multiple match looks like
+ a repeat..until: we only need a conditional jump
+ at the end of the loop. */
if (emptyp) BUF_PUSH (no_op);
STORE_JUMP (emptyp ? on_failure_jump_nastyloop
: on_failure_jump, b, laststart);
{
/* The repeat...until naturally matches one or more.
To also match zero times, we need to first jump to
- the end of the loop (its conditional jump). */
+ the end of the loop (its conditional jump). */
INSERT_JUMP (jump, laststart, b);
b += 3;
}
goto unfetch_interval;
}
- if (upper_bound == 0)
- /* If the upper bound is zero, just drop the sub pattern
- altogether. */
- b = laststart;
- else if (lower_bound == 1 && upper_bound == 1)
- /* Just match it once: nothing to do here. */
- ;
-
- /* Otherwise, we have a nontrivial interval. When
- we're all done, the pattern will look like:
- set_number_at <jump count> <upper bound>
- set_number_at <succeed_n count> <lower bound>
-
succeed_n <after jump addr> <succeed_n count>
- <body of loop>
- jump_n <succeed_n addr> <jump count>
- (The upper bound and `jump_n' are omitted if
- `upper_bound' is 1, though.) */
- else
- { /* If the upper bound is > 1, we need to insert
- more at the end of the loop. */
- unsigned int nbytes = (upper_bound < 0 ? 3
- : upper_bound > 1 ? 5 : 0);
- unsigned int startoffset = 0;
-
- GET_BUFFER_SPACE (20); /* We might use less. */
-
- if (lower_bound == 0)
- {
- /* A succeed_n that starts with 0 is really a
- a simple on_failure_jump_loop. */
- INSERT_JUMP (on_failure_jump_loop, laststart,
- b + 3 + nbytes);
- b += 3;
- }
- else
- {
- /* Initialize lower bound of the `succeed_n', even
- though it will be set during matching by its
- attendant `set_number_at' (inserted next),
- because `re_compile_fastmap' needs to know.
- Jump to the `jump_n' we might insert below. */
- INSERT_JUMP2 (succeed_n, laststart,
- b + 5 + nbytes,
- lower_bound);
- b += 5;
-
- /* Code to initialize the lower bound. Insert
- before the `succeed_n'. The `5' is the last two
- bytes of this `set_number_at', plus 3 bytes of
- the following `succeed_n'. */
- insert_op2 (set_number_at, laststart, 5, lower_bound, b);
- b += 5;
- startoffset += 5;
- }
-
- if (upper_bound < 0)
- {
- /* A negative upper bound stands for infinity,
- in which case it degenerates to a plain jump. */
- STORE_JUMP (jump, b, laststart + startoffset);
- b += 3;
- }
- else if (upper_bound > 1)
- { /* More than one repetition is allowed, so
- append a backward jump to the `succeed_n'
- that starts this interval.
-
- When we've reached this during matching,
- we'll have matched the interval once, so
- jump back only `upper_bound - 1' times. */
- STORE_JUMP2 (jump_n, b, laststart + startoffset,
- upper_bound - 1);
- b += 5;
-
- /* The location we want to set is the second
- parameter of the `jump_n'; that is `b-2' as
- an absolute address. `laststart' will be
- the `set_number_at' we're about to insert;
- `laststart+3' the number to set, the source
- for the relative address. But we are
- inserting into the middle of the pattern --
- so everything is getting moved up by 5.
- Conclusion: (b - 2) - (laststart + 3) + 5,
- i.e., b - laststart.
-
- We insert this at the beginning of the loop
- so that if we fail during matching, we'll
- reinitialize the bounds. */
- insert_op2 (set_number_at, laststart, b - laststart,
- upper_bound - 1, b);
- b += 5;
- }
- }
+ if (upper_bound == 0)
+ /* If the upper bound is zero, just drop the sub pattern
+ altogether. */
+ b = laststart;
+ else if (lower_bound == 1 && upper_bound == 1)
+ /* Just match it once: nothing to do here. */
+ ;
+
+ /* Otherwise, we have a nontrivial interval. When
+ we're all done, the pattern will look like:
+ set_number_at <jump count> <upper bound>
+ set_number_at <succeed_n count> <lower bound>
+ succeed_n <after jump addr> <succeed_n count>
+ <body of loop>
+ jump_n <succeed_n addr> <jump count>
+ (The upper bound and `jump_n' are omitted if
+ `upper_bound' is 1, though.) */
+ else
+ { /* If the upper bound is > 1, we need to insert
+ more at the end of the loop. */
+ unsigned int nbytes = (upper_bound < 0 ? 3
+ : upper_bound > 1 ? 5 : 0);
+ unsigned int startoffset = 0;
+
+ GET_BUFFER_SPACE (20); /* We might use less. */
+
+ if (lower_bound == 0)
+ {
+ /* A succeed_n that starts with 0 is really a
+ a simple on_failure_jump_loop. */
+ INSERT_JUMP (on_failure_jump_loop, laststart,
+ b + 3 + nbytes);
+ b += 3;
+ }
+ else
+ {
+ /* Initialize lower bound of the `succeed_n', even
+ though it will be set during matching by its
+ attendant `set_number_at' (inserted next),
+ because `re_compile_fastmap' needs to know.
+ Jump to the `jump_n' we might insert below. */
+ INSERT_JUMP2 (succeed_n, laststart,
+ b + 5 + nbytes,
+ lower_bound);
+ b += 5;
+
+ /* Code to initialize the lower bound. Insert
+ before the `succeed_n'. The `5' is the last two
+ bytes of this `set_number_at', plus 3 bytes of
+ the following `succeed_n'. */
+ insert_op2 (set_number_at, laststart, 5, lower_bound, b);
+ b += 5;
+ startoffset += 5;
+ }
+
+ if (upper_bound < 0)
+ {
+ /* A negative upper bound stands for infinity,
+ in which case it degenerates to a plain jump. */
+ STORE_JUMP (jump, b, laststart + startoffset);
+ b += 3;
+ }
+ else if (upper_bound > 1)
+ { /* More than one repetition is allowed, so
+ append a backward jump to the `succeed_n'
+ that starts this interval.
+
+ When we've reached this during matching,
+ we'll have matched the interval once, so
+ jump back only `upper_bound - 1' times. */
+ STORE_JUMP2 (jump_n, b, laststart + startoffset,
+ upper_bound - 1);
+ b += 5;
+
+ /* The location we want to set is the second
+ parameter of the `jump_n'; that is `b-2' as
+ an absolute address. `laststart' will be
+ the `set_number_at' we're about to insert;
+ `laststart+3' the number to set, the source
+ for the relative address. But we are
+ inserting into the middle of the pattern --
+ so everything is getting moved up by 5.
+ Conclusion: (b - 2) - (laststart + 3) + 5,
+ i.e., b - laststart.
+
+ We insert this at the beginning of the loop
+ so that if we fail during matching, we'll
+ reinitialize the bounds. */
+ insert_op2 (set_number_at, laststart, b - laststart,
+ upper_bound - 1, b);
+ b += 5;
+ }
+ }
pending_exact = 0;
beg_interval = NULL;
}
cycle detection cannot work. Worse yet, such a detection
can not only fail to detect a cycle, but it can also wrongly
detect a cycle (between different instantiations of the same
- loop.
+ loop).
So the method used for those nasty loops is a little different:
We use a special cycle-detection-stack-frame which is pushed
when the on_failure_jump_nastyloop failure-point is *popped*.
mcnt, p + mcnt);
assert ((re_opcode_t)p[-4] == no_op);
- CHECK_INFINITE_LOOP (p - 4, d);
- PUSH_FAILURE_POINT (p - 3, d);
+ {
+ int cycle = 0;
+ CHECK_INFINITE_LOOP (p - 4, d);
+ if (!cycle)
+ /* If there's a cycle, just continue without pushing
+ this failure point. The failure point is the "try again"
+ option, which shouldn't be tried.
+ We want (x?)*?y\1z to match both xxyz and xxyxz. */
+ PUSH_FAILURE_POINT (p - 3, d);
+ }
break;
-
/* Simple loop detecting on_failure_jump: just check on the
failure stack if the same spot was already hit earlier. */
case on_failure_jump_loop:
EXTRACT_NUMBER_AND_INCR (mcnt, p);
DEBUG_PRINT3 ("EXECUTING on_failure_jump_loop %d (to %p):\n",
mcnt, p + mcnt);
-
- CHECK_INFINITE_LOOP (p - 3, d);
- PUSH_FAILURE_POINT (p - 3, d);
+ {
+ int cycle = 0;
+ CHECK_INFINITE_LOOP (p - 3, d);
+ if (cycle)
+ /* If there's a cycle, get out of the loop, as if the matching
+ had failed. We used to just `goto fail' here, but that was
+ aborting the search a bit too early: we want to keep the
+ empty-loop-match and keep matching after the loop.
+ We want (x?)*y\1z to match both xxyz and xxyxz. */
+ p += mcnt;
+ else
+ PUSH_FAILURE_POINT (p - 3, d);
+ }
break;
projects / gnulib.git / blobdiff