Mercurial > hg > octave-lyh > gnulib-hg
changeset 2345:93d6633849d6
This is a big redesign of failure-stack and register handling, prompted
by bugs revealed when trying to add shy-groups. Overall, what happened
is that loops are now structured a little differently, groups can be
shy and the code is a little simpler.
(enum re_opcode_t): Remove jump_past_alt, maybe_pop_jump,
push_dummy_failure and dumy_failure_jump.
Add on_failure_jump_(exclusive, loop and smart).
Also fix the comment for (start|stop)_memory since they now only take
one argument (the second has becomes unnecessary).
(print_partial_compiled_pattern): Adjust for changes in re_opcode_t.
(print_compiled_pattern): Use %ld to printf long ints and flush to make
debugging a little easier.
(union fail_stack_elt): Make the integer unsigned.
(struct fail_stack_type): Add a `frame' element.
(INIT_FAIL_STACK): Init `frame' as well.
(POP_PATTERN_OP): New macro for re_compile_fastmap.
(DEBUG_PUSH, DEBUG_POP): Remove.
(NUM_REG_ITEMS): Remove.
(NUM_NONREG_ITEMS): Adjust.
(FAILURE_PAT, FAILURE_STR, NEXT_FAILURE_HANDLE, TOP_FAILURE_HANDLE):
New macros for the cycle detection.
(ENSURE_FAIL_STACK): New macro for PUSH_FAILURE_(REG|POINT).
(PUSH_FAILURE_REG, POP_FAILURE_REG, CHECK_INFINITE_LOOP): New macros.
(PUSH_FAILURE_POINT): Don't push registers any more.
The pattern address pushed is not the destination of the jump
but the source of it instead.
(NUM_FAILURE_ITEMS): Remove.
(POP_FAILURE_POINT): Adapt to the new stack structure (i.e. pop
registers before the actual failure point).
Don't hardcode any meaning for str==NULL anymore.
(union register_info_type, REG_MATCH_NULL_STRING_P, IS_ACTIVE)
(MATCHED_SOMETHING, EVER_MATCHED_SOMETHING, SET_REGS_MATCHED): Remove.
(REG_UNSET_VALUE): Use NULL (why not?).
(compile_range): Remove declaration since it doesn't exist.
(struct compile_stack_elt_t): Remove inner_group_offset.
(old_reg(start|end), reg_info, reg_dummy, reg_info_dummy): Remove.
(regex_grow_registers): Remove dead code.
(FIXUP_ALT_JUMP): New macro.
(regex_compile): Add shy-groups
Change loops to use on_failure_jump_smart&jump instead of
on_failure_jump&maybe_pop_jump.
Change + loops to eliminate the initial (dummy_failure_)jump.
Remove c1_base (looks like unused variable to me).
Use `jump' instead of `jump_past_alt' and don't bother with
push_dummy_failure in alternatives since it is now unnecessary.
Use FIXUP_ALT_JUMP.
Eliminate a useless `#ifdef emacs' for (re)allocating the stack.
(re_compile_fastmap): Remove dead variables i and num_regs.
Exit from loop when bufp->can_be_null rather than jumping to `done'.
Avoid jumping backwards so as to ensure termination.
Use PATTERN_STACK_EMPTY and POP_PATTERN_OP.
Improved handling of backreferences.
Remove dead code in handling of `anychar'.
(skip_noops, mutually_exclusive_p): New functions taken from the
handling of `maybe_pop_jump' in re_match_2_internal.
Slightly improve mutually_exclusive_p to handle ".+\n".
((lowest|highest)_active_reg, NO_(LOWEST|HIGHEST)_ACTIVE_REG)
Remove.
(re_match_2_internal): Use %p instead of 0x%x when printf'ing ptrs.
Don't SET_REGS_MATCHED anymore. Remove many dead variables.
Push register (in `start_memory') on the stack rather than storing it
in old_reg(start|end).
Remove the cycle detection from `stop_memory', replaced by the use
of on_failure_jump_loop for greedy loops.
Add code for the new on_failure_jump_<foo>.
Remove ad-hoc code in `on_failure_jump' to push more registers
in the case of a loop.
Take out code from `maybe_pop_jump' into separate functions and
adapt it to the semantics of `on_failure_jump_smart'.
Remove jump_past_alt, dummy_failure_jump and push_dummy_failure.
Remove dummy_failure handling and handling of `failures to jump
to on_failure_jump' (this last one was already dead code, it seems).
((group|alt|common_op)_match_null_string_p): Remove.
author | Stefan Monnier <monnier@iro.umontreal.ca> |
---|---|
date | Wed, 08 Mar 2000 23:25:41 +0000 |
parents | 6d1817aab7c9 |
children | 577179b11fe9 |
files | regex.c |
diffstat | 1 files changed, 636 insertions(+), 1232 deletions(-) [+] |
line wrap: on
line diff
--- a/regex.c +++ b/regex.c @@ -2,7 +2,7 @@ 0.12. (Implements POSIX draft P10003.2/D11.2, except for internationalization features.) - Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc. + Copyright (C) 1993,94,95,96,97,98,2000 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -19,6 +19,14 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ +/* TODO: + - detect nasty infinite loops like "\\(\\)+?ab" when matching "ac". + - use `keep_string' more often than just .*\n. + - structure the opcode space into opcode+flag. + - merge with glic's regex.[ch] + + That's it for now -sm */ + /* AIX requires this to be the first thing in the file. */ #if defined (_AIX) && !defined (REGEX_MALLOC) #pragma alloca @@ -473,19 +481,13 @@ /* Start remembering the text that is matched, for storing in a register. Followed by one byte with the register number, in the range 0 to one less than the pattern buffer's re_nsub - field. Then followed by one byte with the number of groups - inner to this one. (This last has to be part of the - start_memory only because we need it in the on_failure_jump - of re_match_2.) */ + field. */ start_memory, /* Stop remembering the text that is matched and store it in a memory register. Followed by one byte with the register number, in the range 0 to one less than `re_nsub' in the - pattern buffer, and one byte with the number of inner groups, - just like `start_memory'. (We need the number of inner - groups here because we don't have any easy way of finding the - corresponding start_memory when we're at a stop_memory.) */ + pattern buffer. */ stop_memory, /* Match a duplicate of something remembered. Followed by one @@ -508,9 +510,6 @@ /* Followed by two byte relative address to which to jump. */ jump, - /* Same as jump, but marks the end of an alternative. */ - jump_past_alt, - /* Followed by two-byte relative address of place to resume at in case of failure. */ on_failure_jump, @@ -519,29 +518,24 @@ current string position when executed. */ on_failure_keep_string_jump, - /* Throw away latest failure point and then jump to following - two-byte relative address. */ - pop_failure_jump, - - /* Change to pop_failure_jump if know won't have to backtrack to - match; otherwise change to jump. This is used to jump - back to the beginning of a repeat. If what follows this jump - clearly won't match what the repeat does, such that we can be - sure that there is no use backtracking out of repetitions - already matched, then we change it to a pop_failure_jump. - Followed by two-byte address. */ - maybe_pop_jump, - - /* Jump to following two-byte address, and push a dummy failure - point. This failure point will be thrown away if an attempt - is made to use it for a failure. A `+' construct makes this - before the first repeat. Also used as an intermediary kind - of jump when compiling an alternative. */ - dummy_failure_jump, - - /* Push a dummy failure point and continue. Used at the end of - alternatives. */ - push_dummy_failure, + /* Like `on_failure_jump', except that it assumes that the + pattern following it is mutually exclusive with the pattern + at the destination of the jump: if one matches something, + the other won't match at all. + Always used via `on_failure_jump_smart'. */ + on_failure_jump_exclusive, + + /* Just like `on_failure_jump', except that it checks that we + don't get stuck in an infinite loop (matching an empty string + indefinitely). */ + on_failure_jump_loop, + + /* A smart `on_failure_jump' used for greedy * and + operators. + It analyses the loop before which it is put and if the + loop does not require backtracking, it changes itself to + `on_failure_jump_exclusive', else it just defaults to + changing itself into `on_failure_jump_loop'. */ + on_failure_jump_smart, /* Followed by two-byte relative address and two-byte number n. After matching N times, jump to the address upon failure. */ @@ -855,13 +849,11 @@ break; case start_memory: - mcnt = *p++; - printf ("/start_memory/%d/%d", mcnt, *p++); + printf ("/start_memory/%d", *p++); break; case stop_memory: - mcnt = *p++; - printf ("/stop_memory/%d/%d", mcnt, *p++); + printf ("/stop_memory/%d", *p++); break; case duplicate: @@ -944,28 +936,19 @@ printf ("/on_failure_keep_string_jump to %d", p + mcnt - start); break; - case dummy_failure_jump: + case on_failure_jump_exclusive: extract_number_and_incr (&mcnt, &p); - printf ("/dummy_failure_jump to %d", p + mcnt - start); + printf ("/on_failure_jump_exclusive to %d", p + mcnt - start); break; - case push_dummy_failure: - printf ("/push_dummy_failure"); - break; - - case maybe_pop_jump: + case on_failure_jump_loop: extract_number_and_incr (&mcnt, &p); - printf ("/maybe_pop_jump to %d", p + mcnt - start); + printf ("/on_failure_jump_loop to %d", p + mcnt - start); break; - case pop_failure_jump: + case on_failure_jump_smart: extract_number_and_incr (&mcnt, &p); - printf ("/pop_failure_jump to %d", p + mcnt - start); - break; - - case jump_past_alt: - extract_number_and_incr (&mcnt, &p); - printf ("/jump_past_alt to %d", p + mcnt - start); + printf ("/on_failure_jump_smart to %d", p + mcnt - start); break; case jump: @@ -1066,7 +1049,7 @@ unsigned char *buffer = bufp->buffer; print_partial_compiled_pattern (buffer, buffer + bufp->used); - printf ("%d bytes used/%d bytes allocated.\n", bufp->used, bufp->allocated); + printf ("%ld bytes used/%ld bytes allocated.\n", bufp->used, bufp->allocated); if (bufp->fastmap_accurate && bufp->fastmap) { @@ -1082,6 +1065,7 @@ printf ("not_bol: %d\t", bufp->not_bol); printf ("not_eol: %d\t", bufp->not_eol); printf ("syntax: %d\n", bufp->syntax); + fflush (stdout); /* Perhaps we should print the translate table? */ } @@ -1246,7 +1230,7 @@ union fail_stack_elt { unsigned char *pointer; - int integer; + unsigned int integer; }; typedef union fail_stack_elt fail_stack_elt_t; @@ -1255,11 +1239,12 @@ { fail_stack_elt_t *stack; unsigned size; - unsigned avail; /* Offset of next open position. */ + unsigned avail; /* Offset of next open position. */ + unsigned frame; /* Offset of the cur constructed frame. */ } fail_stack_type; -#define FAIL_STACK_EMPTY() (fail_stack.avail == 0) -#define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0) +#define PATTERN_STACK_EMPTY() (fail_stack.avail == 0) +#define FAIL_STACK_EMPTY() (fail_stack.frame == 0) #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size) @@ -1278,6 +1263,7 @@ \ fail_stack.size = INIT_FAILURE_ALLOC; \ fail_stack.avail = 0; \ + fail_stack.frame = 0; \ } while (0) #define RESET_FAIL_STACK() REGEX_FREE_STACK (fail_stack.stack) @@ -1285,6 +1271,7 @@ #define INIT_FAIL_STACK() \ do { \ fail_stack.avail = 0; \ + fail_stack.frame = 0; \ } while (0) #define RESET_FAIL_STACK() @@ -1337,6 +1324,7 @@ ? 0 \ : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER, \ 1)) +#define POP_PATTERN_OP() POP_FAILURE_POINTER () /* Push a pointer value onto the failure stack. Assumes the variable `fail_stack'. Probably should only @@ -1362,110 +1350,105 @@ #define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer #define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail] -/* Used to omit pushing failure point id's when we're not debugging. */ -#ifdef DEBUG -#define DEBUG_PUSH PUSH_FAILURE_INT -#define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT () -#else -#define DEBUG_PUSH(item) -#define DEBUG_POP(item_addr) -#endif - - +/* Individual items aside from the registers. */ +#define NUM_NONREG_ITEMS 3 + +/* Used to examine the stack (to detect infinite loops). */ +#define FAILURE_PAT(h) fail_stack.stack[(h) - 1].pointer +#define FAILURE_STR(h) ((char*)fail_stack.stack[(h) - 2].pointer) +#define NEXT_FAILURE_HANDLE(h) fail_stack.stack[(h) - 3].integer +#define TOP_FAILURE_HANDLE() fail_stack.frame + + +#define ENSURE_FAIL_STACK(space) \ +while (REMAINING_AVAIL_SLOTS <= space) { \ + if (!GROW_FAIL_STACK (fail_stack)) \ + return -2; \ + DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", (fail_stack).size);\ + DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\ +} + +/* Push register NUM onto the stack. */ +#define PUSH_FAILURE_REG(num) \ +do { \ + char *destination; \ + ENSURE_FAIL_STACK(3); \ + DEBUG_PRINT4 (" Push reg %d (spanning %p -> %p)\n", \ + num, regstart[num], regend[num]); \ + PUSH_FAILURE_POINTER (regstart[num]); \ + PUSH_FAILURE_POINTER (regend[num]); \ + PUSH_FAILURE_INT (num); \ +} while (0) + +/* Pop a saved register off the stack. */ +#define POP_FAILURE_REG() \ +do { \ + int reg = POP_FAILURE_INT (); \ + regend[reg] = POP_FAILURE_POINTER (); \ + regstart[reg] = POP_FAILURE_POINTER (); \ + DEBUG_PRINT4 (" Pop 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 { \ + int failure = TOP_FAILURE_HANDLE(); \ + /* Check for infinite matching loops */ \ + while (failure > 0 && \ + (FAILURE_STR (failure) == string_place \ + || FAILURE_STR (failure) == NULL)) \ + { \ + assert (FAILURE_PAT (failure) >= bufp->buffer \ + && FAILURE_PAT (failure) <= bufp->buffer + bufp->used);\ + if (FAILURE_PAT (failure) == pat_cur) \ + goto fail; \ + 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. - Requires variables fail_stack, regstart, regend, reg_info, and + Requires variables fail_stack, regstart, regend and num_regs be declared. GROW_FAIL_STACK requires `destination' be declared. Does `return FAILURE_CODE' if runs out of memory. */ -#define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code) \ - do { \ - char *destination; \ - /* Must be int, so when we don't save any registers, the arithmetic \ - of 0 + -1 isn't done as unsigned. */ \ - int this_reg; \ - \ - DEBUG_STATEMENT (failure_id++); \ - DEBUG_STATEMENT (nfailure_points_pushed++); \ - DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \ - DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail);\ - DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\ - \ - DEBUG_PRINT2 (" slots needed: %d\n", NUM_FAILURE_ITEMS); \ - DEBUG_PRINT2 (" available: %d\n", REMAINING_AVAIL_SLOTS); \ - \ - /* Ensure we have enough space allocated for what we will push. */ \ - while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS) \ - { \ - if (!GROW_FAIL_STACK (fail_stack)) \ - return failure_code; \ - \ - DEBUG_PRINT2 ("\n Doubled stack; size now: %d\n", \ - (fail_stack).size); \ - DEBUG_PRINT2 (" slots available: %d\n", REMAINING_AVAIL_SLOTS);\ - } \ - \ - /* Push the info, starting with the registers. */ \ - DEBUG_PRINT1 ("\n"); \ - \ - if (1) \ - for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \ - this_reg++) \ - { \ - DEBUG_PRINT2 (" Pushing reg: %d\n", this_reg); \ - DEBUG_STATEMENT (num_regs_pushed++); \ - \ - DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \ - PUSH_FAILURE_POINTER (regstart[this_reg]); \ - \ - DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \ - PUSH_FAILURE_POINTER (regend[this_reg]); \ - \ - DEBUG_PRINT2 (" info: 0x%x\n ", reg_info[this_reg]); \ - DEBUG_PRINT2 (" match_null=%d", \ - REG_MATCH_NULL_STRING_P (reg_info[this_reg])); \ - DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg])); \ - DEBUG_PRINT2 (" matched_something=%d", \ - MATCHED_SOMETHING (reg_info[this_reg])); \ - DEBUG_PRINT2 (" ever_matched=%d", \ - EVER_MATCHED_SOMETHING (reg_info[this_reg])); \ - DEBUG_PRINT1 ("\n"); \ - PUSH_FAILURE_ELT (reg_info[this_reg].word); \ - } \ - \ - DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\ - PUSH_FAILURE_INT (lowest_active_reg); \ - \ - DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\ - PUSH_FAILURE_INT (highest_active_reg); \ - \ - DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \ - DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \ - PUSH_FAILURE_POINTER (pattern_place); \ - \ - DEBUG_PRINT2 (" Pushing string 0x%x: `", string_place); \ - DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, \ - size2); \ - DEBUG_PRINT1 ("'\n"); \ - PUSH_FAILURE_POINTER (string_place); \ - \ - DEBUG_PRINT2 (" Pushing failure id: %u\n", failure_id); \ - DEBUG_PUSH (failure_id); \ - } while (0) - -/* This is the number of items that are pushed and popped on the stack - for each register. */ -#define NUM_REG_ITEMS 3 - -/* Individual items aside from the registers. */ -#ifdef DEBUG -#define NUM_NONREG_ITEMS 5 /* Includes failure point id. */ -#else -#define NUM_NONREG_ITEMS 4 -#endif +#define PUSH_FAILURE_POINT(pattern, string_place) \ +do { \ + char *destination; \ + /* Must be int, so when we don't save any registers, the arithmetic \ + of 0 + -1 isn't done as unsigned. */ \ + \ + DEBUG_STATEMENT (failure_id++); \ + DEBUG_STATEMENT (nfailure_points_pushed++); \ + DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id); \ + DEBUG_PRINT2 (" Before push, next avail: %d\n", (fail_stack).avail); \ + DEBUG_PRINT2 (" size: %d\n", (fail_stack).size);\ + \ + ENSURE_FAIL_STACK (NUM_NONREG_ITEMS); \ + \ + DEBUG_PRINT1 ("\n"); \ + \ + DEBUG_PRINT2 (" Push frame index: %d\n", fail_stack.frame); \ + PUSH_FAILURE_INT (fail_stack.frame); \ + \ + DEBUG_PRINT2 (" Push string %p: `", string_place); \ + DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2, size2);\ + DEBUG_PRINT1 ("'\n"); \ + PUSH_FAILURE_POINTER (string_place); \ + \ + DEBUG_PRINT2 (" Push pattern %p: ", pattern); \ + DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern, pend); \ + PUSH_FAILURE_POINTER (pattern); \ + \ + /* Close the frame by moving the frame pointer past it. */ \ + fail_stack.frame = fail_stack.avail; \ +} while (0) /* Estimate the size of data pushed by a typical failure stack entry. An estimate is all we need, because all we use this for @@ -1473,14 +1456,6 @@ #define TYPICAL_FAILURE_SIZE 20 -/* This is how many items we actually use for a failure point. - It depends on the regexp. */ -#define NUM_FAILURE_ITEMS \ - (((0 \ - ? 0 : highest_active_reg - lowest_active_reg + 1) \ - * NUM_REG_ITEMS) \ - + NUM_NONREG_ITEMS) - /* How many items can still be added to the stack without overflowing it. */ #define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail) @@ -1490,19 +1465,13 @@ We restore into the parameters, all of which should be lvalues: STR -- the saved data position. PAT -- the saved pattern position. - LOW_REG, HIGH_REG -- the highest and lowest active registers. REGSTART, REGEND -- arrays of string positions. - REG_INFO -- array of information about each subexpression. Also assumes the variables `fail_stack' and (if debugging), `bufp', `pend', `string1', `size1', `string2', and `size2'. */ -#define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\ -{ \ - DEBUG_STATEMENT (fail_stack_elt_t failure_id;) \ - int this_reg; \ - const unsigned char *string_temp; \ - \ +#define POP_FAILURE_POINT(str, pat) \ +do { \ assert (!FAIL_STACK_EMPTY ()); \ \ /* Remove failure points and point to how many regs pushed. */ \ @@ -1510,119 +1479,35 @@ DEBUG_PRINT2 (" Before pop, next avail: %d\n", fail_stack.avail); \ DEBUG_PRINT2 (" size: %d\n", fail_stack.size); \ \ - assert (fail_stack.avail >= NUM_NONREG_ITEMS); \ + /* Pop the saved registers. */ \ + while (fail_stack.frame < fail_stack.avail) \ + POP_FAILURE_REG (); \ \ - DEBUG_POP (&failure_id.integer); \ - DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id.integer); \ + pat = (unsigned char *) POP_FAILURE_POINTER (); \ + DEBUG_PRINT2 (" Popping pattern %p: ", pat); \ + DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \ \ /* If the saved string location is NULL, it came from an \ on_failure_keep_string_jump opcode, and we want to throw away the \ saved NULL, thus retaining our current position in the string. */ \ - string_temp = POP_FAILURE_POINTER (); \ - if (string_temp != NULL) \ - str = (const char *) string_temp; \ - \ - DEBUG_PRINT2 (" Popping string 0x%x: `", str); \ + str = (char *) POP_FAILURE_POINTER (); \ + DEBUG_PRINT2 (" Popping string %p: `", str); \ DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \ DEBUG_PRINT1 ("'\n"); \ \ - pat = (unsigned char *) POP_FAILURE_POINTER (); \ - DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \ - DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \ - \ - /* Restore register info. */ \ - high_reg = (unsigned) POP_FAILURE_INT (); \ - DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \ - \ - low_reg = (unsigned) POP_FAILURE_INT (); \ - DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \ - \ - if (1) \ - for (this_reg = high_reg; this_reg >= low_reg; this_reg--) \ - { \ - DEBUG_PRINT2 (" Popping reg: %d\n", this_reg); \ - \ - reg_info[this_reg].word = POP_FAILURE_ELT (); \ - DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \ + fail_stack.frame = POP_FAILURE_INT (); \ + DEBUG_PRINT2 (" Popping frame index: %d\n", fail_stack.frame); \ \ - regend[this_reg] = (const char *) POP_FAILURE_POINTER (); \ - DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \ + assert (fail_stack.avail >= 0); \ + assert (fail_stack.frame <= fail_stack.avail); \ \ - regstart[this_reg] = (const char *) POP_FAILURE_POINTER (); \ - DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \ - } \ - else \ - { \ - for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \ - { \ - reg_info[this_reg].word.integer = 0; \ - regend[this_reg] = 0; \ - regstart[this_reg] = 0; \ - } \ - highest_active_reg = high_reg; \ - } \ - \ - set_regs_matched_done = 0; \ DEBUG_STATEMENT (nfailure_points_popped++); \ -} /* POP_FAILURE_POINT */ +} while (0) /* POP_FAILURE_POINT */ -/* Structure for per-register (a.k.a. per-group) information. - Other register information, such as the - starting and ending positions (which are addresses), and the list of - inner groups (which is a bits list) are maintained in separate - variables. - - We are making a (strictly speaking) nonportable assumption here: that - the compiler will pack our bit fields into something that fits into - the type of `word', i.e., is something that fits into one item on the - failure stack. */ - -typedef union -{ - fail_stack_elt_t word; - struct - { - /* This field is one if this group can match the empty string, - zero if not. If not yet determined, `MATCH_NULL_UNSET_VALUE'. */ -#define MATCH_NULL_UNSET_VALUE 3 - unsigned match_null_string_p : 2; - unsigned is_active : 1; - unsigned matched_something : 1; - unsigned ever_matched_something : 1; - } bits; -} register_info_type; - -#define REG_MATCH_NULL_STRING_P(R) ((R).bits.match_null_string_p) -#define IS_ACTIVE(R) ((R).bits.is_active) -#define MATCHED_SOMETHING(R) ((R).bits.matched_something) -#define EVER_MATCHED_SOMETHING(R) ((R).bits.ever_matched_something) - - -/* Call this when have matched a real character; it sets `matched' flags - for the subexpressions which we are currently inside. Also records - that those subexprs have matched. */ -#define SET_REGS_MATCHED() \ - do \ - { \ - if (!set_regs_matched_done) \ - { \ - unsigned r; \ - set_regs_matched_done = 1; \ - for (r = lowest_active_reg; r <= highest_active_reg; r++) \ - { \ - MATCHED_SOMETHING (reg_info[r]) \ - = EVER_MATCHED_SOMETHING (reg_info[r]) \ - = 1; \ - } \ - } \ - } \ - while (0) - /* Registers are set to a sentinel when they haven't yet matched. */ -static char reg_unset_dummy; -#define REG_UNSET_VALUE (®_unset_dummy) +#define REG_UNSET_VALUE NULL #define REG_UNSET(e) ((e) == REG_UNSET_VALUE) /* Subroutine declarations and macros for regex_compile. */ @@ -1631,7 +1516,6 @@ static void insert_op1 (), insert_op2 (); static boolean at_begline_loc_p (), at_endline_loc_p (); static boolean group_in_compile_stack (); -static reg_errcode_t compile_range (); /* Fetch the next character in the uncompiled pattern---translating it if necessary. Also cast from a signed character in the constant @@ -1778,7 +1662,6 @@ { pattern_offset_t begalt_offset; pattern_offset_t fixup_alt_jump; - pattern_offset_t inner_group_offset; pattern_offset_t laststart_offset; regnum_t regnum; } compile_stack_elt_t; @@ -1920,11 +1803,7 @@ static int regs_allocated_size; static const char ** regstart, ** regend; -static const char ** old_regstart, ** old_regend; static const char **best_regstart, **best_regend; -static register_info_type *reg_info; -static const char **reg_dummy; -static register_info_type *reg_info_dummy; /* Make the register vectors big enough for NUM_REGS registers, but don't make them smaller. */ @@ -1937,13 +1816,8 @@ { RETALLOC_IF (regstart, num_regs, const char *); RETALLOC_IF (regend, num_regs, const char *); - RETALLOC_IF (old_regstart, num_regs, const char *); - RETALLOC_IF (old_regend, num_regs, const char *); RETALLOC_IF (best_regstart, num_regs, const char *); RETALLOC_IF (best_regend, num_regs, const char *); - RETALLOC_IF (reg_info, num_regs, register_info_type); - RETALLOC_IF (reg_dummy, num_regs, const char *); - RETALLOC_IF (reg_info_dummy, num_regs, register_info_type); regs_allocated_size = num_regs; } @@ -1969,6 +1843,15 @@ The `fastmap' and `newline_anchor' fields are neither examined nor set. */ +/* Insert the `jump' from the end of last alternative to "here". + The space for the jump has already been allocated. */ +#define FIXUP_ALT_JUMP() \ +do { \ + if (fixup_alt_jump) \ + STORE_JUMP (jump, fixup_alt_jump, b); \ +} while (0) + + /* Return, freeing storage we allocated. */ #define FREE_STACK_RETURN(value) \ do { \ @@ -2042,6 +1925,7 @@ struct range_table_work_area range_table_work; #ifdef DEBUG + /* debug = 1; */ DEBUG_PRINT1 ("\nCompiling pattern: "); if (debug) { @@ -2258,9 +2142,8 @@ keep_string_p = true; } else - /* Anything else. */ - STORE_JUMP (maybe_pop_jump, b, laststart - 3); - + STORE_JUMP (jump, b, laststart - 3); + /* We've added more stuff to the buffer. */ b += 3; } @@ -2268,31 +2151,29 @@ /* On failure, jump from laststart to b + 3, which will be the end of the buffer after this jump is inserted. */ GET_BUFFER_SPACE (3); - INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump - : on_failure_jump, - laststart, b + 3); - pending_exact = 0; - b += 3; - if (!zero_times_ok) { - /* At least one repetition is required, so insert a - `dummy_failure_jump' before the initial - `on_failure_jump' instruction of the loop. This - effects a skip over that instruction the first time - we hit that loop. */ - GET_BUFFER_SPACE (3); - INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6); + assert (many_times_ok); + INSERT_JUMP (on_failure_jump_smart, b - 3, b + 3); + pending_exact = 0; b += 3; } - + else + { + INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump + : !many_times_ok ? + on_failure_jump : on_failure_jump_smart, + laststart, b + 3); + pending_exact = 0; + b += 3; + } } else /* not greedy */ { /* I wish the greedy and non-greedy cases could be merged. */ if (many_times_ok) { - /* The greedy multiple match looks like a repeat..until: + /* The non-greedy multiple match looks like a repeat..until: we only need a conditional jump at the end of the loop */ GET_BUFFER_SPACE (3); STORE_JUMP (on_failure_jump, b, laststart); @@ -2556,7 +2437,9 @@ Split that into two ranges,, the low one ending at 0237, and the high one starting at ...040. */ - int c1_base = (c1 & ~0177) | 040; + /* Unless I'm missing something, + this line is useless. -sm + int c1_base = (c1 & ~0177) | 040; */ SET_RANGE_TABLE_WORK_AREA (range_table_work, c, c1); c1 = 0237; } @@ -2678,8 +2561,31 @@ goto normal_backslash; handle_open: - bufp->re_nsub++; - regnum++; + { + int shy = 0; + if (p+1 < pend) + { + /* Look for a special (?...) construct */ + PATFETCH (c); + if ((syntax & RE_SHY_GROUPS) && c == '?') + { + PATFETCH (c); + switch (c) + { + case ':': shy = 1; break; + default: + /* Only (?:...) is supported right now. */ + FREE_STACK_RETURN (REG_BADPAT); + } + } + else PATUNFETCH; + } + + if (!shy) + { + bufp->re_nsub++; + regnum++; + } if (COMPILE_STACK_FULL) { @@ -2698,17 +2604,13 @@ COMPILE_STACK_TOP.fixup_alt_jump = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0; COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer; - COMPILE_STACK_TOP.regnum = regnum; - - /* We will eventually replace the 0 with the number of - groups inner to this one. But do not push a + COMPILE_STACK_TOP.regnum = shy ? -regnum : regnum; + + /* Do not push a start_memory for groups beyond the last one we can represent in the compiled pattern. */ - if (regnum <= MAX_REGNUM) - { - COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2; - BUF_PUSH_3 (start_memory, regnum, 0); - } + if (regnum <= MAX_REGNUM && !shy) + BUF_PUSH_2 (start_memory, regnum); compile_stack.avail++; @@ -2720,36 +2622,30 @@ clear pending_exact explicitly. */ pending_exact = 0; break; - + } case ')': if (syntax & RE_NO_BK_PARENS) goto normal_backslash; if (COMPILE_STACK_EMPTY) - if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD) - goto normal_backslash; - else - FREE_STACK_RETURN (REG_ERPAREN); + { + if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD) + goto normal_backslash; + else + FREE_STACK_RETURN (REG_ERPAREN); + } handle_close: - if (fixup_alt_jump) - { /* Push a dummy failure point at the end of the - alternative for a possible future - `pop_failure_jump' to pop. See comments at - `push_dummy_failure' in `re_match_2'. */ - BUF_PUSH (push_dummy_failure); - - /* We allocated space for this jump when we assigned - to `fixup_alt_jump', in the `handle_alt' case below. */ - STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1); - } + FIXUP_ALT_JUMP (); /* See similar code for backslashed left paren above. */ if (COMPILE_STACK_EMPTY) - if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD) - goto normal_char; - else - FREE_STACK_RETURN (REG_ERPAREN); + { + if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD) + goto normal_char; + else + FREE_STACK_RETURN (REG_ERPAREN); + } /* Since we just checked for an empty stack above, this ``can't happen''. */ @@ -2775,15 +2671,8 @@ /* We're at the end of the group, so now we know how many groups were inside this one. */ - if (this_group_regnum <= MAX_REGNUM) - { - unsigned char *inner_group_loc - = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset; - - *inner_group_loc = regnum - this_group_regnum; - BUF_PUSH_3 (stop_memory, this_group_regnum, - regnum - this_group_regnum); - } + if (this_group_regnum <= MAX_REGNUM && this_group_regnum > 0) + BUF_PUSH_2 (stop_memory, this_group_regnum); } break; @@ -2818,8 +2707,7 @@ fixup_alt_jump to right after `b', and leave behind three bytes which we'll fill in when we get to after `c'. */ - if (fixup_alt_jump) - STORE_JUMP (jump_past_alt, fixup_alt_jump, b); + FIXUP_ALT_JUMP (); /* Mark and leave space for a jump after this alternative, to be filled in later either by next alternative or @@ -3173,8 +3061,7 @@ /* Through the pattern now. */ - if (fixup_alt_jump) - STORE_JUMP (jump_past_alt, fixup_alt_jump, b); + FIXUP_ALT_JUMP (); if (!COMPILE_STACK_EMPTY) FREE_STACK_RETURN (REG_EPAREN); @@ -3192,8 +3079,10 @@ #ifdef DEBUG if (debug) { + re_compile_fastmap (bufp); DEBUG_PRINT1 ("\nCompiled pattern: \n"); print_compiled_pattern (bufp); + /* debug = 0; */ } #endif /* DEBUG */ @@ -3208,17 +3097,6 @@ { fail_stack.size = re_max_failures * TYPICAL_FAILURE_SIZE; -#ifdef emacs - if (! fail_stack.stack) - fail_stack.stack - = (fail_stack_elt_t *) xmalloc (fail_stack.size - * sizeof (fail_stack_elt_t)); - else - fail_stack.stack - = (fail_stack_elt_t *) xrealloc (fail_stack.stack, - (fail_stack.size - * sizeof (fail_stack_elt_t))); -#else /* not emacs */ if (! fail_stack.stack) fail_stack.stack = (fail_stack_elt_t *) malloc (fail_stack.size @@ -3228,7 +3106,6 @@ = (fail_stack_elt_t *) realloc (fail_stack.stack, (fail_stack.size * sizeof (fail_stack_elt_t))); -#endif /* not emacs */ } regex_grow_registers (num_regs); @@ -3388,15 +3265,13 @@ re_compile_fastmap (bufp) struct re_pattern_buffer *bufp; { - int i, j, k; + int j, k; #ifdef MATCH_MAY_ALLOCATE fail_stack_type fail_stack; #endif #ifndef REGEX_MALLOC char *destination; #endif - /* We don't push any register information onto the failure stack. */ - unsigned num_regs = 0; register char *fastmap = bufp->fastmap; unsigned char *pattern = bufp->buffer; @@ -3431,19 +3306,45 @@ bufp->fastmap_accurate = 1; /* It will be when we're done. */ bufp->can_be_null = 0; - while (1) + /* The loop below works as follows: + - It has a working-list kept in the PATTERN_STACK and which basically + starts by only containing a pointer to the first operation. + - If the opcode we're looking at is a match against some set of + chars, then we add those chars to the fastmap and go on to the + next work element from the worklist (done via `break'). + - If the opcode is a control operator on the other hand, we either + ignore it (if it's meaningless at this point, such as `start_memory') + or execute it (if it's a jump). If the jump has several destinations + (i.e. `on_failure_jump'), then we push the other destination onto the + worklist. + We guarantee termination by ignoring backward jumps (more or less), + so that `p' is monotonically increasing. More to the point, we + never set `p' (or push) anything `<= p1'. */ + + /* If can_be_null is set, then the fastmap will not be used anyway. */ + while (!bufp->can_be_null) { + /* `p1' is used as a marker of how far back a `on_failure_jump' + can go without being ignored. It is normally equal to `p' + (which prevents any backward `on_failure_jump') except right + after a plain `jump', to allow patterns such as: + 0: jump 10 + 3..9: <body> + 10: on_failure_jump 3 + as used for the *? operator. */ + unsigned char *p1 = p; + if (p == pend || *p == succeed) { /* We have reached the (effective) end of pattern. */ - if (!FAIL_STACK_EMPTY ()) + if (!PATTERN_STACK_EMPTY ()) { bufp->can_be_null |= path_can_be_null; /* Reset for next path. */ path_can_be_null = true; - p = fail_stack.stack[--fail_stack.avail].pointer; + p = POP_PATTERN_OP (); continue; } @@ -3457,14 +3358,13 @@ switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++)) { - /* I guess the idea here is to simply not bother with a fastmap - if a backreference is used, since it's too hard to figure out - the fastmap for the corresponding group. Setting - `can_be_null' stops `re_search_2' from using the fastmap, so - that is all we do. */ case duplicate: - bufp->can_be_null = 1; - goto done; + /* If the first character has to match a backreference, that means + that the group was empty (since it already matched). Since this + is the only case that interests us here, we can assume that the + backreference must match the empty string. */ + p++; + continue; /* Following are the cases which match a character. These end @@ -3534,9 +3434,8 @@ multibyte character in the range table. */ int c, count; - /* Make P points the range table. `+ 2' is to skip flag - bits for a character class. */ - p += CHARSET_BITMAP_SIZE (&p[-2]) + 2; + /* Make P points the range table. */ + p += CHARSET_BITMAP_SIZE (&p[-2]); /* Extract the number of ranges in range table into COUNT. */ EXTRACT_NUMBER_AND_INCR (count, p); @@ -3630,11 +3529,6 @@ if (!(bufp->syntax & RE_DOT_NEWLINE)) fastmap['\n'] = fastmap_newline; - /* Return if we have already set `can_be_null'; if we have, - then the fastmap is irrelevant. Something's wrong here. */ - else if (bufp->can_be_null) - goto done; - /* Otherwise, have to check alternative paths. */ break; } @@ -3649,7 +3543,7 @@ /* This match depends on text properties. These end with aborting optimizations. */ bufp->can_be_null = 1; - goto done; + continue; #if 0 k = *p++; simple_char_max = bufp->multibyte ? 0x80 : (1 << BYTEWIDTH); @@ -3727,44 +3621,38 @@ case wordbeg: case wordend: #endif - case push_dummy_failure: continue; case jump_n: - case pop_failure_jump: - case maybe_pop_jump: case jump: - case jump_past_alt: - case dummy_failure_jump: EXTRACT_NUMBER_AND_INCR (j, p); + if (j < 0) + /* Backward jumps can only go back to code that we've already + visited. `re_compile' should make sure this is true. */ + break; p += j; - if (j > 0) - continue; - - /* Jump backward implies we just went through the body of a - loop and matched nothing. Opcode jumped to should be - `on_failure_jump' or `succeed_n'. Just treat it like an - ordinary jump. For a * loop, it has pushed its failure - point already; if so, discard that as redundant. */ - if ((re_opcode_t) *p != on_failure_jump - && (re_opcode_t) *p != succeed_n) - continue; - - p++; - EXTRACT_NUMBER_AND_INCR (j, p); - p += j; - - /* If what's on the stack is where we are now, pop it. */ - if (!FAIL_STACK_EMPTY () - && fail_stack.stack[fail_stack.avail - 1].pointer == p) - fail_stack.avail--; - - continue; - + switch (SWITCH_ENUM_CAST ((re_opcode_t) *p)) + { + case on_failure_jump: + case on_failure_keep_string_jump: + case on_failure_jump_exclusive: + case on_failure_jump_loop: + case on_failure_jump_smart: + p++; + break; + default: + continue; + }; + /* Keep `p1' to allow the `on_failure_jump' we are jumping to + to jump back to "just after here". */ + /* Fallthrough */ case on_failure_jump: case on_failure_keep_string_jump: + case on_failure_jump_exclusive: + case on_failure_jump_loop: + case on_failure_jump_smart: handle_on_failure_jump: EXTRACT_NUMBER_AND_INCR (j, p); @@ -3775,7 +3663,10 @@ to push such a point since we obviously won't find any more fastmap entries beyond `pend'. Such a pattern can match the null string, though. */ - if (p + j < pend) + if (p + j <= p1) + /* Backward jump to be ignored. */ + ; + else if (p + j < pend) { if (!PUSH_PATTERN_OP (p + j, fail_stack)) { @@ -3817,7 +3708,7 @@ case start_memory: case stop_memory: - p += 2; + p += 1; continue; @@ -3838,8 +3729,6 @@ /* Set `can_be_null' for the last path (also the first path, if the pattern is empty). */ bufp->can_be_null |= path_can_be_null; - - done: RESET_FAIL_STACK (); return 0; } /* re_compile_fastmap */ @@ -4167,9 +4056,6 @@ /* Declarations and macros for re_match_2. */ static int bcmp_translate (); -static boolean alt_match_null_string_p (), - common_op_match_null_string_p (), - group_match_null_string_p (); /* This converts PTR, a pointer into one of the search strings `string1' and `string2' into an offset from the beginning of that string. */ @@ -4237,27 +4123,208 @@ REGEX_FREE_STACK (fail_stack.stack); \ FREE_VAR (regstart); \ FREE_VAR (regend); \ - FREE_VAR (old_regstart); \ - FREE_VAR (old_regend); \ FREE_VAR (best_regstart); \ FREE_VAR (best_regend); \ - FREE_VAR (reg_info); \ - FREE_VAR (reg_dummy); \ - FREE_VAR (reg_info_dummy); \ } while (0) #else #define FREE_VARIABLES() ((void)0) /* Do nothing! But inhibit gcc warning. */ #endif /* not MATCH_MAY_ALLOCATE */ -/* These values must meet several constraints. They must not be valid - register values; since we have a limit of 255 registers (because - we use only one byte in the pattern for the register number), we can - use numbers larger than 255. They must differ by 1, because of - NUM_FAILURE_ITEMS above. And the value for the lowest register must - be larger than the value for the highest register, so we do not try - to actually save any registers when none are active. */ -#define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH) -#define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1) + +/* Optimization routines. */ + +/* Jump over non-matching operations. */ +static unsigned char * +skip_noops (p, pend, memory) + unsigned char *p, *pend; + int memory; +{ + int mcnt; + while (p < pend) + { + switch (SWITCH_ENUM_CAST ((re_opcode_t) *p)) + { + case start_memory: + if (!memory) + return p; + case stop_memory: + p += 2; break; + case no_op: + p += 1; break; + case jump: + p += 1; + EXTRACT_NUMBER_AND_INCR (mcnt, p); + p += mcnt; + break; + default: + return p; + } + } + assert (p == pend); + return p; +} + +/* Non-zero if "p1 matches something" implies "p2 fails". */ +static int +mutually_exclusive_p (bufp, p1, p2) + struct re_pattern_buffer *bufp; + unsigned char *p1, *p2; +{ + int multibyte = bufp->multibyte; + unsigned char *pend = bufp->buffer + bufp->used; + + assert (p1 >= bufp->buffer && p1 <= pend + && p2 >= bufp->buffer && p2 <= pend); + + /* Skip over open/close-group commands. + If what follows this loop is a ...+ construct, + look at what begins its body, since we will have to + match at least one of that. */ + p2 = skip_noops (p2, pend, 1); + /* The same skip can be done for p1, except that skipping over + start_memory is not a good idea (if there's a group inside + the loop delimited by on_failure_jump_exclusive, then it + can't optimize the push away (it still works properly, but + slightly slower rather than faster)). */ + p1 = skip_noops (p1, pend, 0); + + /* If we're at the end of the pattern, we can change. */ + if (p2 == pend) + { + switch (SWITCH_ENUM_CAST ((re_opcode_t) *p1)) + { + case anychar: + case charset_not: + case charset: + case exactn: + DEBUG_PRINT1 (" End of pattern: fast loop.\n"); + return 1; + default: + return 0; + } + } + + else if ((re_opcode_t) *p2 == exactn + || (bufp->newline_anchor && (re_opcode_t) *p2 == endline)) + { + register unsigned int c + = *p2 == (unsigned char) endline ? '\n' : p2[2]; + + if ((re_opcode_t) *p1 == exactn) + { + if (!(multibyte /* && (c != '\n') */ + && BASE_LEADING_CODE_P (c)) + ? c != p1[2] + : (STRING_CHAR (&p2[2], pend - &p2[2]) + != STRING_CHAR (&p1[2], pend - &p1[2]))) + { + DEBUG_PRINT3 (" '%c' != '%c' => fast loop.\n", c, p1[2]); + return 1; + } + } + + else if ((re_opcode_t) *p1 == charset + || (re_opcode_t) *p1 == charset_not) + { + int not = (re_opcode_t) *p1 == charset_not; + + if (multibyte /* && (c != '\n') */ + && BASE_LEADING_CODE_P (c)) + c = STRING_CHAR (&p2[2], pend - &p2[2]); + + /* Test if C is listed in charset (or charset_not) + at `p1'. */ + if (SINGLE_BYTE_CHAR_P (c)) + { + if (c < CHARSET_BITMAP_SIZE (p1) * BYTEWIDTH + && p1[2 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) + not = !not; + } + else if (CHARSET_RANGE_TABLE_EXISTS_P (p1)) + CHARSET_LOOKUP_RANGE_TABLE (not, c, p1); + + /* `not' is equal to 1 if c would match, which means + that we can't change to pop_failure_jump. */ + if (!not) + { + DEBUG_PRINT1 (" No match => fast loop.\n"); + return 1; + } + } + else if ((re_opcode_t) *p1 == anychar + && c == '\n') + { + DEBUG_PRINT1 (" . != \\n => fast loop.\n"); + return 1; + } + } + else if ((re_opcode_t) *p2 == charset + || (re_opcode_t) *p2 == charset_not) + { + if ((re_opcode_t) *p1 == exactn) + /* Reuse the code above. */ + return mutually_exclusive_p (bufp, p2, p1); + + + /* It is hard to list up all the character in charset + P2 if it includes multibyte character. Give up in + such case. */ + else if (!multibyte || !CHARSET_RANGE_TABLE_EXISTS_P (p2)) + { + /* Now, we are sure that P2 has no range table. + So, for the size of bitmap in P2, `p2[1]' is + enough. But P1 may have range table, so the + size of bitmap table of P1 is extracted by + using macro `CHARSET_BITMAP_SIZE'. + + Since we know that all the character listed in + P2 is ASCII, it is enough to test only bitmap + table of P1. */ + + if (*p1 == *p2) + { + int idx; + /* We win if the charset inside the loop + has no overlap with the one after the loop. */ + for (idx = 0; + (idx < (int) p2[1] + && idx < CHARSET_BITMAP_SIZE (p1)); + idx++) + if ((p2[2 + idx] & p1[2 + idx]) != 0) + break; + + if (idx == p2[1] + || idx == CHARSET_BITMAP_SIZE (p1)) + { + DEBUG_PRINT1 (" No match => fast loop.\n"); + return 1; + } + } + else if ((re_opcode_t) *p1 == charset + || (re_opcode_t) *p1 == charset_not) + { + int idx; + /* We win if the charset_not inside the loop lists + every character listed in the charset after. */ + for (idx = 0; idx < (int) p2[1]; idx++) + if (! (p2[2 + idx] == 0 + || (idx < CHARSET_BITMAP_SIZE (p1) + && ((p2[2 + idx] & ~ p1[2 + idx]) == 0)))) + break; + + if (idx == p2[1]) + { + DEBUG_PRINT1 (" No match => fast loop.\n"); + return 1; + } + } + } + } + + /* Safe default. */ + return 0; +} + /* Matching routines. */ @@ -4351,10 +4418,6 @@ unsigned char *p = bufp->buffer; register unsigned char *pend = p + bufp->used; - /* Mark the opcode just after a start_memory, so we can test for an - empty subpattern when we get to the stop_memory. */ - unsigned char *just_past_start_mem = 0; - /* We use this to map every character in the string. */ RE_TRANSLATE_TYPE translate = bufp->translate; @@ -4363,13 +4426,11 @@ /* Failure point stack. Each place that can handle a failure further down the line pushes a failure point on this stack. It consists of - restart, regend, and reg_info for all registers corresponding to + regstart, and regend for all registers corresponding to the subexpressions we're currently inside, plus the number of such registers, and, finally, two char *'s. The first char * is where to resume scanning the pattern; the second one is where to resume - scanning the strings. If the latter is zero, the failure point is - a ``dummy''; if a failure happens and the failure point is a dummy, - it gets discarded and the next next one is tried. */ + scanning the strings. */ #ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */ fail_stack_type fail_stack; #endif @@ -4387,10 +4448,6 @@ an element for register zero. */ unsigned num_regs = bufp->re_nsub + 1; - /* The currently active registers. */ - unsigned lowest_active_reg = NO_LOWEST_ACTIVE_REG; - unsigned highest_active_reg = NO_HIGHEST_ACTIVE_REG; - /* Information on the contents of registers. These are pointers into the input strings; they record just what was matched (on this attempt) by a subexpression part of the pattern, that is, the @@ -4402,25 +4459,6 @@ const char **regstart, **regend; #endif - /* If a group that's operated upon by a repetition operator fails to - match anything, then the register for its start will need to be - restored because it will have been set to wherever in the string we - are when we last see its open-group operator. Similarly for a - register's end. */ -#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */ - const char **old_regstart, **old_regend; -#endif - - /* The is_active field of reg_info helps us keep track of which (possibly - nested) subexpressions we are currently in. The matched_something - field of reg_info[reg_num] helps us tell whether or not we have - matched any of the pattern so far this time through the reg_num-th - subexpression. These two fields get reset each time through any - loop their register is in. */ -#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global. */ - register_info_type *reg_info; -#endif - /* The following record the register info as found in the above variables when we find a match better than any we've seen before. This happens as we backtrack through the failure points, which in @@ -4440,15 +4478,6 @@ and need to test it, it's not garbage. */ const char *match_end = NULL; - /* This helps SET_REGS_MATCHED avoid doing redundant work. */ - int set_regs_matched_done = 0; - - /* Used when we pop values we don't care about. */ -#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global. */ - const char **reg_dummy; - register_info_type *reg_info_dummy; -#endif - #ifdef DEBUG /* Counts the total number of registers pushed. */ unsigned num_regs_pushed = 0; @@ -4468,16 +4497,10 @@ { regstart = REGEX_TALLOC (num_regs, const char *); regend = REGEX_TALLOC (num_regs, const char *); - old_regstart = REGEX_TALLOC (num_regs, const char *); - old_regend = REGEX_TALLOC (num_regs, const char *); best_regstart = REGEX_TALLOC (num_regs, const char *); best_regend = REGEX_TALLOC (num_regs, const char *); - reg_info = REGEX_TALLOC (num_regs, register_info_type); - reg_dummy = REGEX_TALLOC (num_regs, const char *); - reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type); - - if (!(regstart && regend && old_regstart && old_regend && reg_info - && best_regstart && best_regend && reg_dummy && reg_info_dummy)) + + if (!(regstart && regend && best_regstart && best_regend)) { FREE_VARIABLES (); return -2; @@ -4487,9 +4510,7 @@ { /* We must initialize all our variables to NULL, so that `FREE_VARIABLES' doesn't try to free them. */ - regstart = regend = old_regstart = old_regend = best_regstart - = best_regend = reg_dummy = NULL; - reg_info = reg_info_dummy = (register_info_type *) NULL; + regstart = regend = best_regstart = best_regend = NULL; } #endif /* MATCH_MAY_ALLOCATE */ @@ -4505,13 +4526,7 @@ register information struct. */ for (mcnt = 1; mcnt < num_regs; mcnt++) { - regstart[mcnt] = regend[mcnt] - = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE; - - REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE; - IS_ACTIVE (reg_info[mcnt]) = 0; - MATCHED_SOMETHING (reg_info[mcnt]) = 0; - EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0; + regstart[mcnt] = regend[mcnt] = REG_UNSET_VALUE; } /* We move `string1' into `string2' if the latter's empty -- but not if @@ -4566,7 +4581,7 @@ fails at this starting point in the input data. */ for (;;) { - DEBUG_PRINT2 ("\n0x%x: ", p); + DEBUG_PRINT2 ("\n%p: ", p); if (p == pend) { /* End of pattern means we might have succeeded. */ @@ -4796,7 +4811,6 @@ } while (--mcnt); } - SET_REGS_MATCHED (); break; @@ -4828,7 +4842,6 @@ && buf_ch == '\000')) goto fail; - SET_REGS_MATCHED (); DEBUG_PRINT2 (" Matched `%d'.\n", *d); d += buf_charlen; } @@ -4913,195 +4926,55 @@ if (!not) goto fail; - SET_REGS_MATCHED (); d += len; break; } /* The beginning of a group is represented by start_memory. - The arguments are the register number in the next byte, and the - number of groups inner to this one in the next. The text + The argument is the register number. The text matched within the group is recorded (in the internal registers data structure) under the register number. */ case start_memory: - DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]); - - /* Find out if this group can match the empty string. */ - p1 = p; /* To send to group_match_null_string_p. */ - - if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE) - REG_MATCH_NULL_STRING_P (reg_info[*p]) - = group_match_null_string_p (&p1, pend, reg_info); - - /* Save the position in the string where we were the last time - we were at this open-group operator in case the group is - operated upon by a repetition operator, e.g., with `(a*)*b' - against `ab'; then we want to ignore where we are now in - the string in case this attempt to match fails. */ - old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p]) - ? REG_UNSET (regstart[*p]) ? d : regstart[*p] - : regstart[*p]; - DEBUG_PRINT2 (" old_regstart: %d\n", - POINTER_TO_OFFSET (old_regstart[*p])); + DEBUG_PRINT2 ("EXECUTING start_memory %d:\n", *p); + + /* In case we need to undo this operation (via backtracking). */ + PUSH_FAILURE_REG ((unsigned int)*p); regstart[*p] = d; + regend[*p] = REG_UNSET_VALUE; /* probably unnecessary. -sm */ DEBUG_PRINT2 (" regstart: %d\n", POINTER_TO_OFFSET (regstart[*p])); - IS_ACTIVE (reg_info[*p]) = 1; - MATCHED_SOMETHING (reg_info[*p]) = 0; - - /* Clear this whenever we change the register activity status. */ - set_regs_matched_done = 0; - - /* This is the new highest active register. */ - highest_active_reg = *p; - - /* If nothing was active before, this is the new lowest active - register. */ - if (lowest_active_reg == NO_LOWEST_ACTIVE_REG) - lowest_active_reg = *p; - /* Move past the register number and inner group count. */ - p += 2; - just_past_start_mem = p; - + p += 1; break; /* The stop_memory opcode represents the end of a group. Its - arguments are the same as start_memory's: the register - number, and the number of inner groups. */ + argument is the same as start_memory's: the register number. */ case stop_memory: - DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]); - - /* We need to save the string position the last time we were at - this close-group operator in case the group is operated - upon by a repetition operator, e.g., with `((a*)*(b*)*)*' - against `aba'; then we want to ignore where we are now in - the string in case this attempt to match fails. */ - old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p]) - ? REG_UNSET (regend[*p]) ? d : regend[*p] - : regend[*p]; - DEBUG_PRINT2 (" old_regend: %d\n", - POINTER_TO_OFFSET (old_regend[*p])); + DEBUG_PRINT2 ("EXECUTING stop_memory %d:\n", *p); + + assert (!REG_UNSET (regstart[*p])); + /* Strictly speaking, there should be code such as: + + assert (REG_UNSET (regend[*p])); + PUSH_FAILURE_REGSTOP ((unsigned int)*p); + + But the only info to be pushed is regend[*p] and it is known to + be UNSET, so there really isn't anything to push. + Not pushing anything, on the other hand deprives us from the + guarantee that regend[*p] is UNSET since undoing this operation + will not reset its value properly. This is not important since + the value will only be read on the next start_memory or at + the very end and both events can only happen if this stop_memory + is *not* undone. */ regend[*p] = d; DEBUG_PRINT2 (" regend: %d\n", POINTER_TO_OFFSET (regend[*p])); - /* This register isn't active anymore. */ - IS_ACTIVE (reg_info[*p]) = 0; - - /* Clear this whenever we change the register activity status. */ - set_regs_matched_done = 0; - - /* If this was the only register active, nothing is active - anymore. */ - if (lowest_active_reg == highest_active_reg) - { - lowest_active_reg = NO_LOWEST_ACTIVE_REG; - highest_active_reg = NO_HIGHEST_ACTIVE_REG; - } - else - { /* We must scan for the new highest active register, since - it isn't necessarily one less than now: consider - (a(b)c(d(e)f)g). When group 3 ends, after the f), the - new highest active register is 1. */ - unsigned char r = *p - 1; - while (r > 0 && !IS_ACTIVE (reg_info[r])) - r--; - - /* If we end up at register zero, that means that we saved - the registers as the result of an `on_failure_jump', not - a `start_memory', and we jumped to past the innermost - `stop_memory'. For example, in ((.)*) we save - registers 1 and 2 as a result of the *, but when we pop - back to the second ), we are at the stop_memory 1. - Thus, nothing is active. */ - if (r == 0) - { - lowest_active_reg = NO_LOWEST_ACTIVE_REG; - highest_active_reg = NO_HIGHEST_ACTIVE_REG; - } - else - highest_active_reg = r; - } - - /* If just failed to match something this time around with a - group that's operated on by a repetition operator, try to - force exit from the ``loop'', and restore the register - information for this group that we had before trying this - last match. */ - if ((!MATCHED_SOMETHING (reg_info[*p]) - || just_past_start_mem == p - 1) - && (p + 2) < pend) - { - boolean is_a_jump_n = false; - - p1 = p + 2; - mcnt = 0; - switch ((re_opcode_t) *p1++) - { - case jump_n: - is_a_jump_n = true; - case pop_failure_jump: - case maybe_pop_jump: - case jump: - case dummy_failure_jump: - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - if (is_a_jump_n) - p1 += 2; - break; - - default: - /* do nothing */ ; - } - p1 += mcnt; - - /* If the next operation is a jump backwards in the pattern - to an on_failure_jump right before the start_memory - corresponding to this stop_memory, exit from the loop - by forcing a failure after pushing on the stack the - on_failure_jump's jump in the pattern, and d. */ - if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump - && (re_opcode_t) p1[3] == start_memory && p1[4] == *p) - { - /* If this group ever matched anything, then restore - what its registers were before trying this last - failed match, e.g., with `(a*)*b' against `ab' for - regstart[1], and, e.g., with `((a*)*(b*)*)*' - against `aba' for regend[3]. - - Also restore the registers for inner groups for, - e.g., `((a*)(b*))*' against `aba' (register 3 would - otherwise get trashed). */ - - if (EVER_MATCHED_SOMETHING (reg_info[*p])) - { - unsigned r; - - EVER_MATCHED_SOMETHING (reg_info[*p]) = 0; - - /* Restore this and inner groups' (if any) registers. */ - for (r = *p; r < *p + *(p + 1); r++) - { - regstart[r] = old_regstart[r]; - - /* xx why this test? */ - if (old_regend[r] >= regstart[r]) - regend[r] = old_regend[r]; - } - } - p1++; - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - PUSH_FAILURE_POINT (p1 + mcnt, d, -2); - - goto fail; - } - } - /* Move past the register number and the inner group count. */ - p += 2; + p += 1; break; @@ -5162,9 +5035,6 @@ : bcmp (d, d2, mcnt)) goto fail; d += mcnt, d2 += mcnt; - - /* Do this because we've match some characters. */ - SET_REGS_MATCHED (); } } break; @@ -5224,7 +5094,7 @@ /* on_failure_keep_string_jump is used to optimize `.*\n'. It pushes NULL as the value for the string on the stack. Then - `pop_failure_point' will keep the current value for the + `POP_FAILURE_POINT' will keep the current value for the string, instead of restoring it. To see why, consider matching `foo\nbar' against `.*\n'. The .* matches the foo; then the . fails against the \n. But the next thing we want @@ -5239,12 +5109,47 @@ `anychar's code to do something besides goto fail in this case; that seems worse than this. */ case on_failure_keep_string_jump: - DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump"); - + EXTRACT_NUMBER_AND_INCR (mcnt, p); + DEBUG_PRINT3 ("EXECUTING on_failure_keep_string_jump %d (to %p):\n", + mcnt, p + mcnt); + + PUSH_FAILURE_POINT (p - 3, NULL); + break; + + case on_failure_jump_exclusive: EXTRACT_NUMBER_AND_INCR (mcnt, p); - DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt); - - PUSH_FAILURE_POINT (p + mcnt, NULL, -2); + DEBUG_PRINT3 ("EXECUTING on_failure_jump_exclusive %d (to %p):\n", + mcnt, p + mcnt); + + if (! FAIL_STACK_EMPTY () + && FAILURE_PAT (TOP_FAILURE_HANDLE ()) == (p - 3) + && fail_stack.avail == fail_stack.frame) + { + /* We are trying to push failure F2 onto the stack but there + is already a failure F1 pushed from the same instruction. + Between F1 and now, something has matched (else this is an + improper use of on_failure_jump_exclusive), so that we know + that the fail-destination of F1 cannot match, hence we can + pop F1 before pushing F2. Instead of doing this pop/push, + we manually turn F1 into F2. + `fail_stack.avail == fail_stack.frame' makes sure + that popping F1 doesn't involve registers, else + this optimization cannot be done so trivially. */ + assert (FAILURE_STR (TOP_FAILURE_HANDLE ()) != d); + FAILURE_STR (TOP_FAILURE_HANDLE ()) = d; + } + else + PUSH_FAILURE_POINT (p - 3, d); + break; + + case on_failure_jump_loop: + on_failure: + 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); break; @@ -5261,272 +5166,55 @@ the repetition text and either the following jump or pop_failure_jump back to this on_failure_jump. */ case on_failure_jump: - on_failure: - DEBUG_PRINT1 ("EXECUTING on_failure_jump"); #if defined (WINDOWSNT) && defined (emacs) QUIT; #endif EXTRACT_NUMBER_AND_INCR (mcnt, p); - DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt); - - /* If this on_failure_jump comes right before a group (i.e., - the original * applied to a group), save the information - for that group and all inner ones, so that if we fail back - to this point, the group's information will be correct. - For example, in \(a*\)*\1, we need the preceding group, - and in \(zz\(a*\)b*\)\2, we need the inner group. */ - - /* We can't use `p' to check ahead because we push - a failure point to `p + mcnt' after we do this. */ - p1 = p; - - /* We need to skip no_op's before we look for the - start_memory in case this on_failure_jump is happening as - the result of a completed succeed_n, as in \(a\)\{1,3\}b\1 - against aba. */ - while (p1 < pend && (re_opcode_t) *p1 == no_op) - p1++; - - if (p1 < pend && (re_opcode_t) *p1 == start_memory) - { - /* We have a new highest active register now. This will - get reset at the start_memory we are about to get to, - but we will have saved all the registers relevant to - this repetition op, as described above. */ - highest_active_reg = *(p1 + 1) + *(p1 + 2); - if (lowest_active_reg == NO_LOWEST_ACTIVE_REG) - lowest_active_reg = *(p1 + 1); - } - - DEBUG_PRINT1 (":\n"); - PUSH_FAILURE_POINT (p + mcnt, d, -2); + DEBUG_PRINT3 ("EXECUTING on_failure_jump %d (to %p):\n", + mcnt, p + mcnt); + + PUSH_FAILURE_POINT (p -3, d); break; - - /* A smart repeat ends with `maybe_pop_jump'. - We change it to either `pop_failure_jump' or `jump'. */ - case maybe_pop_jump: + /* This operation is used for greedy * and +. + Compare the beginning of the repeat with what in the + pattern follows its end. If we can establish that there + is nothing that they would both match, i.e., that we + would have to backtrack because of (as in, e.g., `a*a') + then we can use a non-backtracking loop based on + on_failure_jump_exclusive instead of on_failure_jump_loop. */ + case on_failure_jump_smart: #if defined (WINDOWSNT) && defined (emacs) QUIT; #endif EXTRACT_NUMBER_AND_INCR (mcnt, p); - DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt); + DEBUG_PRINT3 ("EXECUTING on_failure_jump_smart %d (to %p).\n", + mcnt, p + mcnt); { - register unsigned char *p2 = p; - - /* Compare the beginning of the repeat with what in the - pattern follows its end. If we can establish that there - is nothing that they would both match, i.e., that we - would have to backtrack because of (as in, e.g., `a*a') - then we can change to pop_failure_jump, because we'll - never have to backtrack. - - This is not true in the case of alternatives: in - `(a|ab)*' we do need to backtrack to the `ab' alternative - (e.g., if the string was `ab'). But instead of trying to - detect that here, the alternative has put on a dummy - failure point which is what we will end up popping. */ - - /* Skip over open/close-group commands. - If what follows this loop is a ...+ construct, - look at what begins its body, since we will have to - match at least one of that. */ - while (1) - { - if (p2 + 2 < pend - && ((re_opcode_t) *p2 == stop_memory - || (re_opcode_t) *p2 == start_memory)) - p2 += 3; - else if (p2 + 6 < pend - && (re_opcode_t) *p2 == dummy_failure_jump) - p2 += 6; - else - break; - } - - p1 = p + mcnt; - /* p1[0] ... p1[2] are the `on_failure_jump' corresponding - to the `maybe_finalize_jump' of this case. Examine what - follows. */ - - /* If we're at the end of the pattern, we can change. */ - if (p2 == pend) - { - /* Consider what happens when matching ":\(.*\)" - against ":/". I don't really understand this code - yet. */ - p[-3] = (unsigned char) pop_failure_jump; - DEBUG_PRINT1 - (" End of pattern: change to `pop_failure_jump'.\n"); - } - - else if ((re_opcode_t) *p2 == exactn - || (bufp->newline_anchor && (re_opcode_t) *p2 == endline)) - { - register unsigned int c - = *p2 == (unsigned char) endline ? '\n' : p2[2]; - - if ((re_opcode_t) p1[3] == exactn) - { - if (!(multibyte /* && (c != '\n') */ - && BASE_LEADING_CODE_P (c)) - ? c != p1[5] - : (STRING_CHAR (&p2[2], pend - &p2[2]) - != STRING_CHAR (&p1[5], pend - &p1[5]))) - { - p[-3] = (unsigned char) pop_failure_jump; - DEBUG_PRINT3 (" %c != %c => pop_failure_jump.\n", - c, p1[5]); - } - } - - else if ((re_opcode_t) p1[3] == charset - || (re_opcode_t) p1[3] == charset_not) - { - int not = (re_opcode_t) p1[3] == charset_not; - - if (multibyte /* && (c != '\n') */ - && BASE_LEADING_CODE_P (c)) - c = STRING_CHAR (&p2[2], pend - &p2[2]); - - /* Test if C is listed in charset (or charset_not) - at `&p1[3]'. */ - if (SINGLE_BYTE_CHAR_P (c)) - { - if (c < CHARSET_BITMAP_SIZE (&p1[3]) * BYTEWIDTH - && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) - not = !not; - } - else if (CHARSET_RANGE_TABLE_EXISTS_P (&p1[3])) - CHARSET_LOOKUP_RANGE_TABLE (not, c, &p1[3]); - - /* `not' is equal to 1 if c would match, which means - that we can't change to pop_failure_jump. */ - if (!not) - { - p[-3] = (unsigned char) pop_failure_jump; - DEBUG_PRINT1 (" No match => pop_failure_jump.\n"); - } - } - } - else if ((re_opcode_t) *p2 == charset) + unsigned char *p1 = p; /* Next operation. */ + unsigned char *p2 = p + mcnt; /* Destination of the jump. */ + + p -= 3; /* Reset so that we will re-execute the + instruction once it's been changed. */ + + /* DEBUG_STATEMENT (debug = 1); */ + if (mutually_exclusive_p (bufp, p1, p2)) { - if ((re_opcode_t) p1[3] == exactn) - { - register unsigned int c = p1[5]; - int not = 0; - - if (multibyte && BASE_LEADING_CODE_P (c)) - c = STRING_CHAR (&p1[5], pend - &p1[5]); - - /* Test if C is listed in charset at `p2'. */ - if (SINGLE_BYTE_CHAR_P (c)) - { - if (c < CHARSET_BITMAP_SIZE (p2) * BYTEWIDTH - && (p2[2 + c / BYTEWIDTH] - & (1 << (c % BYTEWIDTH)))) - not = !not; - } - else if (CHARSET_RANGE_TABLE_EXISTS_P (p2)) - CHARSET_LOOKUP_RANGE_TABLE (not, c, p2); - - if (!not) - { - p[-3] = (unsigned char) pop_failure_jump; - DEBUG_PRINT1 (" No match => pop_failure_jump.\n"); - } - } - - /* It is hard to list up all the character in charset - P2 if it includes multibyte character. Give up in - such case. */ - else if (!multibyte || !CHARSET_RANGE_TABLE_EXISTS_P (p2)) - { - /* Now, we are sure that P2 has no range table. - So, for the size of bitmap in P2, `p2[1]' is - enough. But P1 may have range table, so the - size of bitmap table of P1 is extracted by - using macro `CHARSET_BITMAP_SIZE'. - - Since we know that all the character listed in - P2 is ASCII, it is enough to test only bitmap - table of P1. */ - - if ((re_opcode_t) p1[3] == charset_not) - { - int idx; - /* We win if the charset_not inside the loop lists - every character listed in the charset after. */ - for (idx = 0; idx < (int) p2[1]; idx++) - if (! (p2[2 + idx] == 0 - || (idx < CHARSET_BITMAP_SIZE (&p1[3]) - && ((p2[2 + idx] & ~ p1[5 + idx]) == 0)))) - break; - - if (idx == p2[1]) - { - p[-3] = (unsigned char) pop_failure_jump; - DEBUG_PRINT1 (" No match => pop_failure_jump.\n"); - } - } - else if ((re_opcode_t) p1[3] == charset) - { - int idx; - /* We win if the charset inside the loop - has no overlap with the one after the loop. */ - for (idx = 0; - (idx < (int) p2[1] - && idx < CHARSET_BITMAP_SIZE (&p1[3])); - idx++) - if ((p2[2 + idx] & p1[5 + idx]) != 0) - break; - - if (idx == p2[1] - || idx == CHARSET_BITMAP_SIZE (&p1[3])) - { - p[-3] = (unsigned char) pop_failure_jump; - DEBUG_PRINT1 (" No match => pop_failure_jump.\n"); - } - } + /* Use a fast `on_failure_keep_string_jump' loop. */ + *p = (unsigned char) on_failure_jump_exclusive; + /* STORE_NUMBER (p2 - 2, mcnt + 3); */ } - } + else + { + /* Default to a safe `on_failure_jump' loop. */ + DEBUG_PRINT1 (" smart default => slow loop.\n"); + *p = (unsigned char) on_failure_jump_loop; + } + /* DEBUG_STATEMENT (debug = 0); */ } - p -= 2; /* Point at relative address again. */ - if ((re_opcode_t) p[-1] != pop_failure_jump) - { - p[-1] = (unsigned char) jump; - DEBUG_PRINT1 (" Match => jump.\n"); - goto unconditional_jump; - } - /* Note fall through. */ - - - /* The end of a simple repeat has a pop_failure_jump back to - its matching on_failure_jump, where the latter will push a - failure point. The pop_failure_jump takes off failure - points put on by this pop_failure_jump's matching - on_failure_jump; we got through the pattern to here from the - matching on_failure_jump, so didn't fail. */ - case pop_failure_jump: - { - /* We need to pass separate storage for the lowest and - highest registers, even though we don't care about the - actual values. Otherwise, we will restore only one - register from the stack, since lowest will == highest in - `pop_failure_point'. */ - unsigned dummy_low_reg, dummy_high_reg; - unsigned char *pdummy; - const char *sdummy; - - DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n"); - POP_FAILURE_POINT (sdummy, pdummy, - dummy_low_reg, dummy_high_reg, - reg_dummy, reg_dummy, reg_info_dummy); - } - /* Note fall through. */ - + break; /* Unconditionally jump (without popping any failure points). */ case jump: @@ -5537,42 +5225,10 @@ EXTRACT_NUMBER_AND_INCR (mcnt, p); /* Get the amount to jump. */ DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt); p += mcnt; /* Do the jump. */ - DEBUG_PRINT2 ("(to 0x%x).\n", p); + DEBUG_PRINT2 ("(to %p).\n", p); break; - /* We need this opcode so we can detect where alternatives end - in `group_match_null_string_p' et al. */ - case jump_past_alt: - DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n"); - goto unconditional_jump; - - - /* Normally, the on_failure_jump pushes a failure point, which - then gets popped at pop_failure_jump. We will end up at - pop_failure_jump, also, and with a pattern of, say, `a+', we - are skipping over the on_failure_jump, so we have to push - something meaningless for pop_failure_jump to pop. */ - case dummy_failure_jump: - DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n"); - /* It doesn't matter what we push for the string here. What - the code at `fail' tests is the value for the pattern. */ - PUSH_FAILURE_POINT (0, 0, -2); - goto unconditional_jump; - - - /* At the end of an alternative, we need to push a dummy failure - point in case we are followed by a `pop_failure_jump', because - we don't want the failure point for the alternative to be - popped. For example, matching `(a|ab)*' against `aab' - requires that we match the `ab' alternative. */ - case push_dummy_failure: - DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n"); - /* See comments just above at `dummy_failure_jump' about the - two zeroes. */ - PUSH_FAILURE_POINT (0, 0, -2); - break; - /* Have to succeed matching what follows at least n times. After that, handle like `on_failure_jump'. */ case succeed_n: @@ -5586,11 +5242,11 @@ mcnt--; p += 2; STORE_NUMBER_AND_INCR (p, mcnt); - DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p, mcnt); + DEBUG_PRINT3 (" Setting %p to %d.\n", p, mcnt); } else if (mcnt == 0) { - DEBUG_PRINT2 (" Setting two bytes from 0x%x to no_op.\n", p+2); + DEBUG_PRINT2 (" Setting two bytes from %p to no_op.\n", p+2); p[2] = (unsigned char) no_op; p[3] = (unsigned char) no_op; goto on_failure; @@ -5620,7 +5276,7 @@ EXTRACT_NUMBER_AND_INCR (mcnt, p); p1 = p + mcnt; EXTRACT_NUMBER_AND_INCR (mcnt, p); - DEBUG_PRINT3 (" Setting 0x%x to %d.\n", p1, mcnt); + DEBUG_PRINT3 (" Setting %p to %d.\n", p1, mcnt); STORE_NUMBER (p1, mcnt); break; } @@ -5837,7 +5493,6 @@ goto fail; d += len; } - SET_REGS_MATCHED (); break; case notsyntaxspec: @@ -5868,7 +5523,6 @@ goto fail; d += len; } - SET_REGS_MATCHED (); break; case categoryspec: @@ -5887,7 +5541,6 @@ goto fail; d += len; } - SET_REGS_MATCHED (); break; case notcategoryspec: @@ -5906,7 +5559,6 @@ goto fail; d += len; } - SET_REGS_MATCHED (); break; #else /* not emacs */ @@ -5915,7 +5567,6 @@ PREFETCH (); if (!WORDCHAR_P (d)) goto fail; - SET_REGS_MATCHED (); d++; break; @@ -5924,7 +5575,6 @@ PREFETCH (); if (WORDCHAR_P (d)) goto fail; - SET_REGS_MATCHED (); d++; break; #endif /* not emacs */ @@ -5941,44 +5591,40 @@ QUIT; #endif if (!FAIL_STACK_EMPTY ()) - { /* A restart point is known. Restore to that state. */ + { + char *str; + unsigned char *pat; + /* A restart point is known. Restore to that state. */ DEBUG_PRINT1 ("\nFAIL:\n"); - POP_FAILURE_POINT (d, p, - lowest_active_reg, highest_active_reg, - regstart, regend, reg_info); - - /* If this failure point is a dummy, try the next one. */ - if (!p) - goto fail; - - /* If we failed to the end of the pattern, don't examine *p. */ - assert (p <= pend); - if (p < pend) - { - boolean is_a_jump_n = false; - - /* If failed to a backwards jump that's part of a repetition - loop, need to pop this failure point and use the next one. */ - switch ((re_opcode_t) *p) - { - case jump_n: - is_a_jump_n = true; - case maybe_pop_jump: - case pop_failure_jump: - case jump: - p1 = p + 1; - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - p1 += mcnt; - - if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n) - || (!is_a_jump_n - && (re_opcode_t) *p1 == on_failure_jump)) - goto fail; - break; - default: - /* do nothing */ ; - } - } + POP_FAILURE_POINT (str, pat); + switch (SWITCH_ENUM_CAST ((re_opcode_t) *pat++)) + { + case on_failure_keep_string_jump: + assert (str == NULL); + goto continue_failure_jump; + + case on_failure_jump_exclusive: + /* If something has matched, the alternative will not match, + so we might as well keep popping right away. */ + if (0 /* d != str && d != string2 */) /* Don't bother. -sm */ + /* (d == string2 && str == end1) => (d =~ str) */ + goto fail; + /* Fallthrough */ + + case on_failure_jump_loop: + case on_failure_jump: + case succeed_n: + d = str; + continue_failure_jump: + EXTRACT_NUMBER_AND_INCR (mcnt, pat); + p = pat + mcnt; + break; + + default: + abort(); + } + + assert (p >= bufp->buffer && p <= pend); if (d >= string1 && d <= end1) dend = end_match_1; @@ -5997,248 +5643,6 @@ /* Subroutine definitions for re_match_2. */ - -/* We are passed P pointing to a register number after a start_memory. - - Return true if the pattern up to the corresponding stop_memory can - match the empty string, and false otherwise. - - If we find the matching stop_memory, sets P to point to one past its number. - Otherwise, sets P to an undefined byte less than or equal to END. - - We don't handle duplicates properly (yet). */ - -static boolean -group_match_null_string_p (p, end, reg_info) - unsigned char **p, *end; - register_info_type *reg_info; -{ - int mcnt; - /* Point to after the args to the start_memory. */ - unsigned char *p1 = *p + 2; - - while (p1 < end) - { - /* Skip over opcodes that can match nothing, and return true or - false, as appropriate, when we get to one that can't, or to the - matching stop_memory. */ - - switch ((re_opcode_t) *p1) - { - /* Could be either a loop or a series of alternatives. */ - case on_failure_jump: - p1++; - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - - /* If the next operation is not a jump backwards in the - pattern. */ - - if (mcnt >= 0) - { - /* Go through the on_failure_jumps of the alternatives, - seeing if any of the alternatives cannot match nothing. - The last alternative starts with only a jump, - whereas the rest start with on_failure_jump and end - with a jump, e.g., here is the pattern for `a|b|c': - - /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6 - /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3 - /exactn/1/c - - So, we have to first go through the first (n-1) - alternatives and then deal with the last one separately. */ - - - /* Deal with the first (n-1) alternatives, which start - with an on_failure_jump (see above) that jumps to right - past a jump_past_alt. */ - - while ((re_opcode_t) p1[mcnt-3] == jump_past_alt) - { - /* `mcnt' holds how many bytes long the alternative - is, including the ending `jump_past_alt' and - its number. */ - - if (!alt_match_null_string_p (p1, p1 + mcnt - 3, - reg_info)) - return false; - - /* Move to right after this alternative, including the - jump_past_alt. */ - p1 += mcnt; - - /* Break if it's the beginning of an n-th alternative - that doesn't begin with an on_failure_jump. */ - if ((re_opcode_t) *p1 != on_failure_jump) - break; - - /* Still have to check that it's not an n-th - alternative that starts with an on_failure_jump. */ - p1++; - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - if ((re_opcode_t) p1[mcnt-3] != jump_past_alt) - { - /* Get to the beginning of the n-th alternative. */ - p1 -= 3; - break; - } - } - - /* Deal with the last alternative: go back and get number - of the `jump_past_alt' just before it. `mcnt' contains - the length of the alternative. */ - EXTRACT_NUMBER (mcnt, p1 - 2); - - if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info)) - return false; - - p1 += mcnt; /* Get past the n-th alternative. */ - } /* if mcnt > 0 */ - break; - - - case stop_memory: - assert (p1[1] == **p); - *p = p1 + 2; - return true; - - - default: - if (!common_op_match_null_string_p (&p1, end, reg_info)) - return false; - } - } /* while p1 < end */ - - return false; -} /* group_match_null_string_p */ - - -/* Similar to group_match_null_string_p, but doesn't deal with alternatives: - It expects P to be the first byte of a single alternative and END one - byte past the last. The alternative can contain groups. */ - -static boolean -alt_match_null_string_p (p, end, reg_info) - unsigned char *p, *end; - register_info_type *reg_info; -{ - int mcnt; - unsigned char *p1 = p; - - while (p1 < end) - { - /* Skip over opcodes that can match nothing, and break when we get - to one that can't. */ - - switch ((re_opcode_t) *p1) - { - /* It's a loop. */ - case on_failure_jump: - p1++; - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - p1 += mcnt; - break; - - default: - if (!common_op_match_null_string_p (&p1, end, reg_info)) - return false; - } - } /* while p1 < end */ - - return true; -} /* alt_match_null_string_p */ - - -/* Deals with the ops common to group_match_null_string_p and - alt_match_null_string_p. - - Sets P to one after the op and its arguments, if any. */ - -static boolean -common_op_match_null_string_p (p, end, reg_info) - unsigned char **p, *end; - register_info_type *reg_info; -{ - int mcnt; - boolean ret; - int reg_no; - unsigned char *p1 = *p; - - switch ((re_opcode_t) *p1++) - { - case no_op: - case begline: - case endline: - case begbuf: - case endbuf: - case wordbeg: - case wordend: - case wordbound: - case notwordbound: -#ifdef emacs - case before_dot: - case at_dot: - case after_dot: -#endif - break; - - case start_memory: - reg_no = *p1; - assert (reg_no > 0 && reg_no <= MAX_REGNUM); - ret = group_match_null_string_p (&p1, end, reg_info); - - /* Have to set this here in case we're checking a group which - contains a group and a back reference to it. */ - - if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE) - REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret; - - if (!ret) - return false; - break; - - /* If this is an optimized succeed_n for zero times, make the jump. */ - case jump: - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - if (mcnt >= 0) - p1 += mcnt; - else - return false; - break; - - case succeed_n: - /* Get to the number of times to succeed. */ - p1 += 2; - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - - if (mcnt == 0) - { - p1 -= 4; - EXTRACT_NUMBER_AND_INCR (mcnt, p1); - p1 += mcnt; - } - else - return false; - break; - - case duplicate: - if (!REG_MATCH_NULL_STRING_P (reg_info[*p1])) - return false; - break; - - case set_number_at: - p1 += 4; - - default: - /* All other opcodes mean we cannot match the empty string. */ - return false; - } - - *p = p1; - return true; -} /* common_op_match_null_string_p */ - - /* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN bytes; nonzero otherwise. */