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2094 lines
48 KiB
2094 lines
48 KiB
/* regexpr.c |
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* |
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* Author: Tatu Ylonen <ylo@ngs.fi> |
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* |
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* Copyright (c) 1991 Tatu Ylonen, Espoo, Finland |
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* |
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* Permission to use, copy, modify, distribute, and sell this software |
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* and its documentation for any purpose is hereby granted without |
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* fee, provided that the above copyright notice appear in all copies. |
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* This software is provided "as is" without express or implied |
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* warranty. |
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* |
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* Created: Thu Sep 26 17:14:05 1991 ylo |
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* Last modified: Mon Nov 4 17:06:48 1991 ylo |
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* Ported to Think C: 19 Jan 1992 guido@cwi.nl |
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* |
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* This code draws many ideas from the regular expression packages by |
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* Henry Spencer of the University of Toronto and Richard Stallman of |
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* the Free Software Foundation. |
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* |
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* Emacs-specific code and syntax table code is almost directly borrowed |
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* from GNU regexp. |
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* |
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* Bugs fixed and lots of reorganization by Jeffrey C. Ollie, April |
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* 1997 Thanks for bug reports and ideas from Andrew Kuchling, Tim |
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* Peters, Guido van Rossum, Ka-Ping Yee, Sjoerd Mullender, and |
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* probably one or two others that I'm forgetting. |
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* |
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* $Id: regexpr.c,v 1.36 2002/08/07 16:21:51 loewis Exp $ */ |
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#include "Python.h" |
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#include "regexpr.h" |
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/* The original code blithely assumed that sizeof(short) == 2. Not |
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* always true. Original instances of "(short)x" were replaced by |
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* SHORT(x), where SHORT is #defined below. */ |
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#define SHORT(x) ((x) & 0x8000 ? (x) - 0x10000 : (x)) |
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/* The stack implementation is taken from an idea by Andrew Kuchling. |
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* It's a doubly linked list of arrays. The advantages of this over a |
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* simple linked list are that the number of mallocs required are |
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* reduced. It also makes it possible to statically allocate enough |
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* space so that small patterns don't ever need to call malloc. |
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* |
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* The advantages over a single array is that is periodically |
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* realloced when more space is needed is that we avoid ever copying |
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* the stack. */ |
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/* item_t is the basic stack element. Defined as a union of |
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* structures so that both registers, failure points, and counters can |
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* be pushed/popped from the stack. There's nothing built into the |
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* item to keep track of whether a certain stack item is a register, a |
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* failure point, or a counter. */ |
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typedef union item_t |
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{ |
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struct |
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{ |
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int num; |
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int level; |
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unsigned char *start; |
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unsigned char *end; |
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} reg; |
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struct |
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{ |
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int count; |
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int level; |
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int phantom; |
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unsigned char *code; |
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unsigned char *text; |
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} fail; |
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struct |
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{ |
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int num; |
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int level; |
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int count; |
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} cntr; |
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} item_t; |
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#define STACK_PAGE_SIZE 256 |
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#define NUM_REGISTERS 256 |
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/* A 'page' of stack items. */ |
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typedef struct item_page_t |
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{ |
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item_t items[STACK_PAGE_SIZE]; |
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struct item_page_t *prev; |
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struct item_page_t *next; |
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} item_page_t; |
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typedef struct match_state |
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{ |
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/* The number of registers that have been pushed onto the stack |
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* since the last failure point. */ |
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int count; |
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/* Used to control when registers need to be pushed onto the |
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* stack. */ |
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int level; |
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/* The number of failure points on the stack. */ |
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int point; |
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/* Storage for the registers. Each register consists of two |
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* pointers to characters. So register N is represented as |
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* start[N] and end[N]. The pointers must be converted to |
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* offsets from the beginning of the string before returning the |
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* registers to the calling program. */ |
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unsigned char *start[NUM_REGISTERS]; |
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unsigned char *end[NUM_REGISTERS]; |
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/* Keeps track of whether a register has changed recently. */ |
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int changed[NUM_REGISTERS]; |
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/* Structure to encapsulate the stack. */ |
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struct |
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{ |
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/* index into the current page. If index == 0 and you need |
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* to pop an item, move to the previous page and set index |
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* = STACK_PAGE_SIZE - 1. Otherwise decrement index to |
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* push a page. If index == STACK_PAGE_SIZE and you need |
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* to push a page move to the next page and set index = |
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* 0. If there is no new next page, allocate a new page |
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* and link it in. Otherwise, increment index to push a |
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* page. */ |
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int index; |
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item_page_t *current; /* Pointer to the current page. */ |
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item_page_t first; /* First page is statically allocated. */ |
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} stack; |
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} match_state; |
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/* Initialize a state object */ |
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/* #define NEW_STATE(state) \ */ |
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/* memset(&state, 0, (void *)(&state.stack) - (void *)(&state)); \ */ |
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/* state.stack.current = &state.stack.first; \ */ |
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/* state.stack.first.prev = NULL; \ */ |
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/* state.stack.first.next = NULL; \ */ |
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/* state.stack.index = 0; \ */ |
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/* state.level = 1 */ |
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#define NEW_STATE(state, nregs) \ |
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{ \ |
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int i; \ |
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for (i = 0; i < nregs; i++) \ |
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{ \ |
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state.start[i] = NULL; \ |
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state.end[i] = NULL; \ |
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state.changed[i] = 0; \ |
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} \ |
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state.stack.current = &state.stack.first; \ |
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state.stack.first.prev = NULL; \ |
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state.stack.first.next = NULL; \ |
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state.stack.index = 0; \ |
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state.level = 1; \ |
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state.count = 0; \ |
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state.level = 0; \ |
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state.point = 0; \ |
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} |
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/* Free any memory that might have been malloc'd */ |
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#define FREE_STATE(state) \ |
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while(state.stack.first.next != NULL) \ |
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{ \ |
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state.stack.current = state.stack.first.next; \ |
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state.stack.first.next = state.stack.current->next; \ |
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free(state.stack.current); \ |
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} |
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/* Discard the top 'count' stack items. */ |
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#define STACK_DISCARD(stack, count, on_error) \ |
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stack.index -= count; \ |
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while (stack.index < 0) \ |
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{ \ |
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if (stack.current->prev == NULL) \ |
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on_error; \ |
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stack.current = stack.current->prev; \ |
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stack.index += STACK_PAGE_SIZE; \ |
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} |
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/* Store a pointer to the previous item on the stack. Used to pop an |
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* item off of the stack. */ |
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#define STACK_PREV(stack, top, on_error) \ |
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if (stack.index == 0) \ |
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{ \ |
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if (stack.current->prev == NULL) \ |
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on_error; \ |
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stack.current = stack.current->prev; \ |
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stack.index = STACK_PAGE_SIZE - 1; \ |
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} \ |
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else \ |
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{ \ |
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stack.index--; \ |
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} \ |
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top = &(stack.current->items[stack.index]) |
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/* Store a pointer to the next item on the stack. Used to push an item |
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* on to the stack. */ |
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#define STACK_NEXT(stack, top, on_error) \ |
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if (stack.index == STACK_PAGE_SIZE) \ |
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{ \ |
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if (stack.current->next == NULL) \ |
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{ \ |
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stack.current->next = (item_page_t *)malloc(sizeof(item_page_t)); \ |
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if (stack.current->next == NULL) \ |
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on_error; \ |
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stack.current->next->prev = stack.current; \ |
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stack.current->next->next = NULL; \ |
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} \ |
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stack.current = stack.current->next; \ |
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stack.index = 0; \ |
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} \ |
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top = &(stack.current->items[stack.index++]) |
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/* Store a pointer to the item that is 'count' items back in the |
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* stack. STACK_BACK(stack, top, 1, on_error) is equivalent to |
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* STACK_TOP(stack, top, on_error). */ |
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#define STACK_BACK(stack, top, count, on_error) \ |
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{ \ |
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int index; \ |
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item_page_t *current; \ |
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current = stack.current; \ |
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index = stack.index - (count); \ |
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while (index < 0) \ |
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{ \ |
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if (current->prev == NULL) \ |
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on_error; \ |
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current = current->prev; \ |
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index += STACK_PAGE_SIZE; \ |
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} \ |
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top = &(current->items[index]); \ |
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} |
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/* Store a pointer to the top item on the stack. Execute the |
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* 'on_error' code if there are no items on the stack. */ |
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#define STACK_TOP(stack, top, on_error) \ |
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if (stack.index == 0) \ |
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{ \ |
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if (stack.current->prev == NULL) \ |
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on_error; \ |
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top = &(stack.current->prev->items[STACK_PAGE_SIZE - 1]); \ |
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} \ |
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else \ |
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{ \ |
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top = &(stack.current->items[stack.index - 1]); \ |
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} |
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/* Test to see if the stack is empty */ |
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#define STACK_EMPTY(stack) ((stack.index == 0) && \ |
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(stack.current->prev == NULL)) |
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/* Return the start of register 'reg' */ |
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#define GET_REG_START(state, reg) (state.start[reg]) |
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/* Return the end of register 'reg' */ |
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#define GET_REG_END(state, reg) (state.end[reg]) |
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/* Set the start of register 'reg'. If the state of the register needs |
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* saving, push it on the stack. */ |
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#define SET_REG_START(state, reg, text, on_error) \ |
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if(state.changed[reg] < state.level) \ |
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{ \ |
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item_t *item; \ |
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STACK_NEXT(state.stack, item, on_error); \ |
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item->reg.num = reg; \ |
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item->reg.start = state.start[reg]; \ |
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item->reg.end = state.end[reg]; \ |
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item->reg.level = state.changed[reg]; \ |
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state.changed[reg] = state.level; \ |
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state.count++; \ |
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} \ |
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state.start[reg] = text |
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/* Set the end of register 'reg'. If the state of the register needs |
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* saving, push it on the stack. */ |
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#define SET_REG_END(state, reg, text, on_error) \ |
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if(state.changed[reg] < state.level) \ |
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{ \ |
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item_t *item; \ |
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STACK_NEXT(state.stack, item, on_error); \ |
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item->reg.num = reg; \ |
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item->reg.start = state.start[reg]; \ |
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item->reg.end = state.end[reg]; \ |
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item->reg.level = state.changed[reg]; \ |
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state.changed[reg] = state.level; \ |
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state.count++; \ |
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} \ |
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state.end[reg] = text |
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#define PUSH_FAILURE(state, xcode, xtext, on_error) \ |
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{ \ |
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item_t *item; \ |
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STACK_NEXT(state.stack, item, on_error); \ |
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item->fail.code = xcode; \ |
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item->fail.text = xtext; \ |
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item->fail.count = state.count; \ |
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item->fail.level = state.level; \ |
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item->fail.phantom = 0; \ |
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state.count = 0; \ |
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state.level++; \ |
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state.point++; \ |
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} |
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/* Update the last failure point with a new position in the text. */ |
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#define UPDATE_FAILURE(state, xtext, on_error) \ |
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{ \ |
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item_t *item; \ |
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STACK_BACK(state.stack, item, state.count + 1, on_error); \ |
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if (!item->fail.phantom) \ |
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{ \ |
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item_t *item2; \ |
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STACK_NEXT(state.stack, item2, on_error); \ |
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item2->fail.code = item->fail.code; \ |
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item2->fail.text = xtext; \ |
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item2->fail.count = state.count; \ |
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item2->fail.level = state.level; \ |
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item2->fail.phantom = 1; \ |
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state.count = 0; \ |
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state.level++; \ |
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state.point++; \ |
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} \ |
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else \ |
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{ \ |
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STACK_DISCARD(state.stack, state.count, on_error); \ |
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STACK_TOP(state.stack, item, on_error); \ |
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item->fail.text = xtext; \ |
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state.count = 0; \ |
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state.level++; \ |
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} \ |
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} |
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#define POP_FAILURE(state, xcode, xtext, on_empty, on_error) \ |
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{ \ |
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item_t *item; \ |
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do \ |
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{ \ |
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while(state.count > 0) \ |
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{ \ |
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STACK_PREV(state.stack, item, on_error); \ |
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state.start[item->reg.num] = item->reg.start; \ |
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state.end[item->reg.num] = item->reg.end; \ |
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state.changed[item->reg.num] = item->reg.level; \ |
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state.count--; \ |
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} \ |
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STACK_PREV(state.stack, item, on_empty); \ |
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xcode = item->fail.code; \ |
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xtext = item->fail.text; \ |
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state.count = item->fail.count; \ |
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state.level = item->fail.level; \ |
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state.point--; \ |
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} \ |
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while (item->fail.text == NULL); \ |
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} |
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enum regexp_compiled_ops /* opcodes for compiled regexp */ |
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{ |
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Cend, /* end of pattern reached */ |
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Cbol, /* beginning of line */ |
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Ceol, /* end of line */ |
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Cset, /* character set. Followed by 32 bytes of set. */ |
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Cexact, /* followed by a byte to match */ |
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Canychar, /* matches any character except newline */ |
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Cstart_memory, /* set register start addr (followed by reg number) */ |
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Cend_memory, /* set register end addr (followed by reg number) */ |
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Cmatch_memory, /* match a duplicate of reg contents (regnum follows)*/ |
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Cjump, /* followed by two bytes (lsb,msb) of displacement. */ |
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Cstar_jump, /* will change to jump/update_failure_jump at runtime */ |
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Cfailure_jump, /* jump to addr on failure */ |
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Cupdate_failure_jump, /* update topmost failure point and jump */ |
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Cdummy_failure_jump, /* push a dummy failure point and jump */ |
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Cbegbuf, /* match at beginning of buffer */ |
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Cendbuf, /* match at end of buffer */ |
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Cwordbeg, /* match at beginning of word */ |
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Cwordend, /* match at end of word */ |
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Cwordbound, /* match if at word boundary */ |
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Cnotwordbound, /* match if not at word boundary */ |
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Csyntaxspec, /* matches syntax code (1 byte follows) */ |
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Cnotsyntaxspec, /* matches if syntax code does not match (1 byte follows) */ |
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Crepeat1 |
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}; |
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enum regexp_syntax_op /* syntax codes for plain and quoted characters */ |
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{ |
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Rend, /* special code for end of regexp */ |
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Rnormal, /* normal character */ |
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Ranychar, /* any character except newline */ |
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Rquote, /* the quote character */ |
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Rbol, /* match beginning of line */ |
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Reol, /* match end of line */ |
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Roptional, /* match preceding expression optionally */ |
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Rstar, /* match preceding expr zero or more times */ |
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Rplus, /* match preceding expr one or more times */ |
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Ror, /* match either of alternatives */ |
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Ropenpar, /* opening parenthesis */ |
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Rclosepar, /* closing parenthesis */ |
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Rmemory, /* match memory register */ |
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Rextended_memory, /* \vnn to match registers 10-99 */ |
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Ropenset, /* open set. Internal syntax hard-coded below. */ |
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/* the following are gnu extensions to "normal" regexp syntax */ |
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Rbegbuf, /* beginning of buffer */ |
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Rendbuf, /* end of buffer */ |
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Rwordchar, /* word character */ |
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Rnotwordchar, /* not word character */ |
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Rwordbeg, /* beginning of word */ |
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Rwordend, /* end of word */ |
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Rwordbound, /* word bound */ |
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Rnotwordbound, /* not word bound */ |
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Rnum_ops |
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}; |
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static int re_compile_initialized = 0; |
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static int regexp_syntax = 0; |
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int re_syntax = 0; /* Exported copy of regexp_syntax */ |
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static unsigned char regexp_plain_ops[256]; |
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static unsigned char regexp_quoted_ops[256]; |
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static unsigned char regexp_precedences[Rnum_ops]; |
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static int regexp_context_indep_ops; |
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static int regexp_ansi_sequences; |
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#define NUM_LEVELS 5 /* number of precedence levels in use */ |
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#define MAX_NESTING 100 /* max nesting level of operators */ |
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#define SYNTAX(ch) re_syntax_table[(unsigned char)(ch)] |
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unsigned char re_syntax_table[256]; |
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void re_compile_initialize(void) |
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{ |
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int a; |
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static int syntax_table_inited = 0; |
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if (!syntax_table_inited) |
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{ |
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syntax_table_inited = 1; |
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memset(re_syntax_table, 0, 256); |
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for (a = 'a'; a <= 'z'; a++) |
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re_syntax_table[a] = Sword; |
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for (a = 'A'; a <= 'Z'; a++) |
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re_syntax_table[a] = Sword; |
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for (a = '0'; a <= '9'; a++) |
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re_syntax_table[a] = Sword | Sdigit | Shexdigit; |
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for (a = '0'; a <= '7'; a++) |
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re_syntax_table[a] |= Soctaldigit; |
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for (a = 'A'; a <= 'F'; a++) |
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re_syntax_table[a] |= Shexdigit; |
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for (a = 'a'; a <= 'f'; a++) |
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re_syntax_table[a] |= Shexdigit; |
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re_syntax_table['_'] = Sword; |
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for (a = 9; a <= 13; a++) |
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re_syntax_table[a] = Swhitespace; |
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re_syntax_table[' '] = Swhitespace; |
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} |
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re_compile_initialized = 1; |
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for (a = 0; a < 256; a++) |
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{ |
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regexp_plain_ops[a] = Rnormal; |
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regexp_quoted_ops[a] = Rnormal; |
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} |
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for (a = '0'; a <= '9'; a++) |
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regexp_quoted_ops[a] = Rmemory; |
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regexp_plain_ops['\134'] = Rquote; |
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if (regexp_syntax & RE_NO_BK_PARENS) |
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{ |
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regexp_plain_ops['('] = Ropenpar; |
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regexp_plain_ops[')'] = Rclosepar; |
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} |
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else |
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{ |
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regexp_quoted_ops['('] = Ropenpar; |
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regexp_quoted_ops[')'] = Rclosepar; |
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} |
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if (regexp_syntax & RE_NO_BK_VBAR) |
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regexp_plain_ops['\174'] = Ror; |
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else |
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regexp_quoted_ops['\174'] = Ror; |
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regexp_plain_ops['*'] = Rstar; |
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if (regexp_syntax & RE_BK_PLUS_QM) |
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{ |
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regexp_quoted_ops['+'] = Rplus; |
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regexp_quoted_ops['?'] = Roptional; |
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} |
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else |
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{ |
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regexp_plain_ops['+'] = Rplus; |
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regexp_plain_ops['?'] = Roptional; |
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} |
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if (regexp_syntax & RE_NEWLINE_OR) |
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regexp_plain_ops['\n'] = Ror; |
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regexp_plain_ops['\133'] = Ropenset; |
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regexp_plain_ops['\136'] = Rbol; |
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regexp_plain_ops['$'] = Reol; |
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regexp_plain_ops['.'] = Ranychar; |
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if (!(regexp_syntax & RE_NO_GNU_EXTENSIONS)) |
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{ |
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regexp_quoted_ops['w'] = Rwordchar; |
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regexp_quoted_ops['W'] = Rnotwordchar; |
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regexp_quoted_ops['<'] = Rwordbeg; |
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regexp_quoted_ops['>'] = Rwordend; |
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regexp_quoted_ops['b'] = Rwordbound; |
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regexp_quoted_ops['B'] = Rnotwordbound; |
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regexp_quoted_ops['`'] = Rbegbuf; |
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regexp_quoted_ops['\''] = Rendbuf; |
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} |
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if (regexp_syntax & RE_ANSI_HEX) |
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regexp_quoted_ops['v'] = Rextended_memory; |
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for (a = 0; a < Rnum_ops; a++) |
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regexp_precedences[a] = 4; |
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if (regexp_syntax & RE_TIGHT_VBAR) |
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{ |
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regexp_precedences[Ror] = 3; |
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regexp_precedences[Rbol] = 2; |
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regexp_precedences[Reol] = 2; |
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} |
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else |
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{ |
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regexp_precedences[Ror] = 2; |
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regexp_precedences[Rbol] = 3; |
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regexp_precedences[Reol] = 3; |
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} |
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regexp_precedences[Rclosepar] = 1; |
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regexp_precedences[Rend] = 0; |
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regexp_context_indep_ops = (regexp_syntax & RE_CONTEXT_INDEP_OPS) != 0; |
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regexp_ansi_sequences = (regexp_syntax & RE_ANSI_HEX) != 0; |
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} |
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|
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int re_set_syntax(int syntax) |
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{ |
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int ret; |
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|
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ret = regexp_syntax; |
|
regexp_syntax = syntax; |
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re_syntax = syntax; /* Exported copy */ |
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re_compile_initialize(); |
|
return ret; |
|
} |
|
|
|
static int hex_char_to_decimal(int ch) |
|
{ |
|
if (ch >= '0' && ch <= '9') |
|
return ch - '0'; |
|
if (ch >= 'a' && ch <= 'f') |
|
return ch - 'a' + 10; |
|
if (ch >= 'A' && ch <= 'F') |
|
return ch - 'A' + 10; |
|
return 16; |
|
} |
|
|
|
static void re_compile_fastmap_aux(unsigned char *code, int pos, |
|
unsigned char *visited, |
|
unsigned char *can_be_null, |
|
unsigned char *fastmap) |
|
{ |
|
int a; |
|
int b; |
|
int syntaxcode; |
|
|
|
if (visited[pos]) |
|
return; /* we have already been here */ |
|
visited[pos] = 1; |
|
for (;;) |
|
switch (code[pos++]) { |
|
case Cend: |
|
{ |
|
*can_be_null = 1; |
|
return; |
|
} |
|
case Cbol: |
|
case Cbegbuf: |
|
case Cendbuf: |
|
case Cwordbeg: |
|
case Cwordend: |
|
case Cwordbound: |
|
case Cnotwordbound: |
|
{ |
|
for (a = 0; a < 256; a++) |
|
fastmap[a] = 1; |
|
break; |
|
} |
|
case Csyntaxspec: |
|
{ |
|
syntaxcode = code[pos++]; |
|
for (a = 0; a < 256; a++) |
|
if (SYNTAX(a) & syntaxcode) |
|
fastmap[a] = 1; |
|
return; |
|
} |
|
case Cnotsyntaxspec: |
|
{ |
|
syntaxcode = code[pos++]; |
|
for (a = 0; a < 256; a++) |
|
if (!(SYNTAX(a) & syntaxcode) ) |
|
fastmap[a] = 1; |
|
return; |
|
} |
|
case Ceol: |
|
{ |
|
fastmap['\n'] = 1; |
|
if (*can_be_null == 0) |
|
*can_be_null = 2; /* can match null, but only at end of buffer*/ |
|
return; |
|
} |
|
case Cset: |
|
{ |
|
for (a = 0; a < 256/8; a++) |
|
if (code[pos + a] != 0) |
|
for (b = 0; b < 8; b++) |
|
if (code[pos + a] & (1 << b)) |
|
fastmap[(a << 3) + b] = 1; |
|
pos += 256/8; |
|
return; |
|
} |
|
case Cexact: |
|
{ |
|
fastmap[(unsigned char)code[pos]] = 1; |
|
return; |
|
} |
|
case Canychar: |
|
{ |
|
for (a = 0; a < 256; a++) |
|
if (a != '\n') |
|
fastmap[a] = 1; |
|
return; |
|
} |
|
case Cstart_memory: |
|
case Cend_memory: |
|
{ |
|
pos++; |
|
break; |
|
} |
|
case Cmatch_memory: |
|
{ |
|
for (a = 0; a < 256; a++) |
|
fastmap[a] = 1; |
|
*can_be_null = 1; |
|
return; |
|
} |
|
case Cjump: |
|
case Cdummy_failure_jump: |
|
case Cupdate_failure_jump: |
|
case Cstar_jump: |
|
{ |
|
a = (unsigned char)code[pos++]; |
|
a |= (unsigned char)code[pos++] << 8; |
|
pos += (int)SHORT(a); |
|
if (visited[pos]) |
|
{ |
|
/* argh... the regexp contains empty loops. This is not |
|
good, as this may cause a failure stack overflow when |
|
matching. Oh well. */ |
|
/* this path leads nowhere; pursue other paths. */ |
|
return; |
|
} |
|
visited[pos] = 1; |
|
break; |
|
} |
|
case Cfailure_jump: |
|
{ |
|
a = (unsigned char)code[pos++]; |
|
a |= (unsigned char)code[pos++] << 8; |
|
a = pos + (int)SHORT(a); |
|
re_compile_fastmap_aux(code, a, visited, can_be_null, fastmap); |
|
break; |
|
} |
|
case Crepeat1: |
|
{ |
|
pos += 2; |
|
break; |
|
} |
|
default: |
|
{ |
|
PyErr_SetString(PyExc_SystemError, "Unknown regex opcode: memory corrupted?"); |
|
return; |
|
/*NOTREACHED*/ |
|
} |
|
} |
|
} |
|
|
|
static int re_do_compile_fastmap(unsigned char *buffer, int used, int pos, |
|
unsigned char *can_be_null, |
|
unsigned char *fastmap) |
|
{ |
|
unsigned char small_visited[512], *visited; |
|
|
|
if (used <= sizeof(small_visited)) |
|
visited = small_visited; |
|
else |
|
{ |
|
visited = malloc(used); |
|
if (!visited) |
|
return 0; |
|
} |
|
*can_be_null = 0; |
|
memset(fastmap, 0, 256); |
|
memset(visited, 0, used); |
|
re_compile_fastmap_aux(buffer, pos, visited, can_be_null, fastmap); |
|
if (visited != small_visited) |
|
free(visited); |
|
return 1; |
|
} |
|
|
|
void re_compile_fastmap(regexp_t bufp) |
|
{ |
|
if (!bufp->fastmap || bufp->fastmap_accurate) |
|
return; |
|
assert(bufp->used > 0); |
|
if (!re_do_compile_fastmap(bufp->buffer, |
|
bufp->used, |
|
0, |
|
&bufp->can_be_null, |
|
bufp->fastmap)) |
|
return; |
|
if (PyErr_Occurred()) return; |
|
if (bufp->buffer[0] == Cbol) |
|
bufp->anchor = 1; /* begline */ |
|
else |
|
if (bufp->buffer[0] == Cbegbuf) |
|
bufp->anchor = 2; /* begbuf */ |
|
else |
|
bufp->anchor = 0; /* none */ |
|
bufp->fastmap_accurate = 1; |
|
} |
|
|
|
/* |
|
* star is coded as: |
|
* 1: failure_jump 2 |
|
* ... code for operand of star |
|
* star_jump 1 |
|
* 2: ... code after star |
|
* |
|
* We change the star_jump to update_failure_jump if we can determine |
|
* that it is safe to do so; otherwise we change it to an ordinary |
|
* jump. |
|
* |
|
* plus is coded as |
|
* |
|
* jump 2 |
|
* 1: failure_jump 3 |
|
* 2: ... code for operand of plus |
|
* star_jump 1 |
|
* 3: ... code after plus |
|
* |
|
* For star_jump considerations this is processed identically to star. |
|
* |
|
*/ |
|
|
|
static int re_optimize_star_jump(regexp_t bufp, unsigned char *code) |
|
{ |
|
unsigned char map[256]; |
|
unsigned char can_be_null; |
|
unsigned char *p1; |
|
unsigned char *p2; |
|
unsigned char ch; |
|
int a; |
|
int b; |
|
int num_instructions = 0; |
|
|
|
a = (unsigned char)*code++; |
|
a |= (unsigned char)*code++ << 8; |
|
a = (int)SHORT(a); |
|
|
|
p1 = code + a + 3; /* skip the failure_jump */ |
|
/* Check that the jump is within the pattern */ |
|
if (p1<bufp->buffer || bufp->buffer+bufp->used<p1) |
|
{ |
|
PyErr_SetString(PyExc_SystemError, "Regex VM jump out of bounds (failure_jump opt)"); |
|
return 0; |
|
} |
|
|
|
assert(p1[-3] == Cfailure_jump); |
|
p2 = code; |
|
/* p1 points inside loop, p2 points to after loop */ |
|
if (!re_do_compile_fastmap(bufp->buffer, bufp->used, |
|
(int)(p2 - bufp->buffer), |
|
&can_be_null, map)) |
|
goto make_normal_jump; |
|
|
|
/* If we might introduce a new update point inside the |
|
* loop, we can't optimize because then update_jump would |
|
* update a wrong failure point. Thus we have to be |
|
* quite careful here. |
|
*/ |
|
|
|
/* loop until we find something that consumes a character */ |
|
loop_p1: |
|
num_instructions++; |
|
switch (*p1++) |
|
{ |
|
case Cbol: |
|
case Ceol: |
|
case Cbegbuf: |
|
case Cendbuf: |
|
case Cwordbeg: |
|
case Cwordend: |
|
case Cwordbound: |
|
case Cnotwordbound: |
|
{ |
|
goto loop_p1; |
|
} |
|
case Cstart_memory: |
|
case Cend_memory: |
|
{ |
|
p1++; |
|
goto loop_p1; |
|
} |
|
case Cexact: |
|
{ |
|
ch = (unsigned char)*p1++; |
|
if (map[(int)ch]) |
|
goto make_normal_jump; |
|
break; |
|
} |
|
case Canychar: |
|
{ |
|
for (b = 0; b < 256; b++) |
|
if (b != '\n' && map[b]) |
|
goto make_normal_jump; |
|
break; |
|
} |
|
case Cset: |
|
{ |
|
for (b = 0; b < 256; b++) |
|
if ((p1[b >> 3] & (1 << (b & 7))) && map[b]) |
|
goto make_normal_jump; |
|
p1 += 256/8; |
|
break; |
|
} |
|
default: |
|
{ |
|
goto make_normal_jump; |
|
} |
|
} |
|
/* now we know that we can't backtrack. */ |
|
while (p1 != p2 - 3) |
|
{ |
|
num_instructions++; |
|
switch (*p1++) |
|
{ |
|
case Cend: |
|
{ |
|
return 0; |
|
} |
|
case Cbol: |
|
case Ceol: |
|
case Canychar: |
|
case Cbegbuf: |
|
case Cendbuf: |
|
case Cwordbeg: |
|
case Cwordend: |
|
case Cwordbound: |
|
case Cnotwordbound: |
|
{ |
|
break; |
|
} |
|
case Cset: |
|
{ |
|
p1 += 256/8; |
|
break; |
|
} |
|
case Cexact: |
|
case Cstart_memory: |
|
case Cend_memory: |
|
case Cmatch_memory: |
|
case Csyntaxspec: |
|
case Cnotsyntaxspec: |
|
{ |
|
p1++; |
|
break; |
|
} |
|
case Cjump: |
|
case Cstar_jump: |
|
case Cfailure_jump: |
|
case Cupdate_failure_jump: |
|
case Cdummy_failure_jump: |
|
{ |
|
goto make_normal_jump; |
|
} |
|
default: |
|
{ |
|
return 0; |
|
} |
|
} |
|
} |
|
|
|
/* make_update_jump: */ |
|
code -= 3; |
|
a += 3; /* jump to after the Cfailure_jump */ |
|
code[0] = Cupdate_failure_jump; |
|
code[1] = a & 0xff; |
|
code[2] = a >> 8; |
|
if (num_instructions > 1) |
|
return 1; |
|
assert(num_instructions == 1); |
|
/* if the only instruction matches a single character, we can do |
|
* better */ |
|
p1 = code + 3 + a; /* start of sole instruction */ |
|
if (*p1 == Cset || *p1 == Cexact || *p1 == Canychar || |
|
*p1 == Csyntaxspec || *p1 == Cnotsyntaxspec) |
|
code[0] = Crepeat1; |
|
return 1; |
|
|
|
make_normal_jump: |
|
code -= 3; |
|
*code = Cjump; |
|
return 1; |
|
} |
|
|
|
static int re_optimize(regexp_t bufp) |
|
{ |
|
unsigned char *code; |
|
|
|
code = bufp->buffer; |
|
|
|
while(1) |
|
{ |
|
switch (*code++) |
|
{ |
|
case Cend: |
|
{ |
|
return 1; |
|
} |
|
case Canychar: |
|
case Cbol: |
|
case Ceol: |
|
case Cbegbuf: |
|
case Cendbuf: |
|
case Cwordbeg: |
|
case Cwordend: |
|
case Cwordbound: |
|
case Cnotwordbound: |
|
{ |
|
break; |
|
} |
|
case Cset: |
|
{ |
|
code += 256/8; |
|
break; |
|
} |
|
case Cexact: |
|
case Cstart_memory: |
|
case Cend_memory: |
|
case Cmatch_memory: |
|
case Csyntaxspec: |
|
case Cnotsyntaxspec: |
|
{ |
|
code++; |
|
break; |
|
} |
|
case Cstar_jump: |
|
{ |
|
if (!re_optimize_star_jump(bufp, code)) |
|
{ |
|
return 0; |
|
} |
|
/* fall through */ |
|
} |
|
case Cupdate_failure_jump: |
|
case Cjump: |
|
case Cdummy_failure_jump: |
|
case Cfailure_jump: |
|
case Crepeat1: |
|
{ |
|
code += 2; |
|
break; |
|
} |
|
default: |
|
{ |
|
return 0; |
|
} |
|
} |
|
} |
|
} |
|
|
|
#define NEXTCHAR(var) \ |
|
{ \ |
|
if (pos >= size) \ |
|
goto ends_prematurely; \ |
|
(var) = regex[pos]; \ |
|
pos++; \ |
|
} |
|
|
|
#define ALLOC(amount) \ |
|
{ \ |
|
if (pattern_offset+(amount) > alloc) \ |
|
{ \ |
|
alloc += 256 + (amount); \ |
|
pattern = realloc(pattern, alloc); \ |
|
if (!pattern) \ |
|
goto out_of_memory; \ |
|
} \ |
|
} |
|
|
|
#define STORE(ch) pattern[pattern_offset++] = (ch) |
|
|
|
#define CURRENT_LEVEL_START (starts[starts_base + current_level]) |
|
|
|
#define SET_LEVEL_START starts[starts_base + current_level] = pattern_offset |
|
|
|
#define PUSH_LEVEL_STARTS \ |
|
if (starts_base < (MAX_NESTING-1)*NUM_LEVELS) \ |
|
starts_base += NUM_LEVELS; \ |
|
else \ |
|
goto too_complex \ |
|
|
|
#define POP_LEVEL_STARTS starts_base -= NUM_LEVELS |
|
|
|
#define PUT_ADDR(offset,addr) \ |
|
{ \ |
|
int disp = (addr) - (offset) - 2; \ |
|
pattern[(offset)] = disp & 0xff; \ |
|
pattern[(offset)+1] = (disp>>8) & 0xff; \ |
|
} |
|
|
|
#define INSERT_JUMP(pos,type,addr) \ |
|
{ \ |
|
int a, p = (pos), t = (type), ad = (addr); \ |
|
for (a = pattern_offset - 1; a >= p; a--) \ |
|
pattern[a + 3] = pattern[a]; \ |
|
pattern[p] = t; \ |
|
PUT_ADDR(p+1,ad); \ |
|
pattern_offset += 3; \ |
|
} |
|
|
|
#define SETBIT(buf,offset,bit) (buf)[(offset)+(bit)/8] |= (1<<((bit) & 7)) |
|
|
|
#define SET_FIELDS \ |
|
{ \ |
|
bufp->allocated = alloc; \ |
|
bufp->buffer = pattern; \ |
|
bufp->used = pattern_offset; \ |
|
} |
|
|
|
#define GETHEX(var) \ |
|
{ \ |
|
unsigned char gethex_ch, gethex_value; \ |
|
NEXTCHAR(gethex_ch); \ |
|
gethex_value = hex_char_to_decimal(gethex_ch); \ |
|
if (gethex_value == 16) \ |
|
goto hex_error; \ |
|
NEXTCHAR(gethex_ch); \ |
|
gethex_ch = hex_char_to_decimal(gethex_ch); \ |
|
if (gethex_ch == 16) \ |
|
goto hex_error; \ |
|
(var) = gethex_value * 16 + gethex_ch; \ |
|
} |
|
|
|
#define ANSI_TRANSLATE(ch) \ |
|
{ \ |
|
switch (ch) \ |
|
{ \ |
|
case 'a': \ |
|
case 'A': \ |
|
{ \ |
|
ch = 7; /* audible bell */ \ |
|
break; \ |
|
} \ |
|
case 'b': \ |
|
case 'B': \ |
|
{ \ |
|
ch = 8; /* backspace */ \ |
|
break; \ |
|
} \ |
|
case 'f': \ |
|
case 'F': \ |
|
{ \ |
|
ch = 12; /* form feed */ \ |
|
break; \ |
|
} \ |
|
case 'n': \ |
|
case 'N': \ |
|
{ \ |
|
ch = 10; /* line feed */ \ |
|
break; \ |
|
} \ |
|
case 'r': \ |
|
case 'R': \ |
|
{ \ |
|
ch = 13; /* carriage return */ \ |
|
break; \ |
|
} \ |
|
case 't': \ |
|
case 'T': \ |
|
{ \ |
|
ch = 9; /* tab */ \ |
|
break; \ |
|
} \ |
|
case 'v': \ |
|
case 'V': \ |
|
{ \ |
|
ch = 11; /* vertical tab */ \ |
|
break; \ |
|
} \ |
|
case 'x': /* hex code */ \ |
|
case 'X': \ |
|
{ \ |
|
GETHEX(ch); \ |
|
break; \ |
|
} \ |
|
default: \ |
|
{ \ |
|
/* other characters passed through */ \ |
|
if (translate) \ |
|
ch = translate[(unsigned char)ch]; \ |
|
break; \ |
|
} \ |
|
} \ |
|
} |
|
|
|
char *re_compile_pattern(unsigned char *regex, int size, regexp_t bufp) |
|
{ |
|
int a; |
|
int pos; |
|
int op; |
|
int current_level; |
|
int level; |
|
int opcode; |
|
int pattern_offset = 0, alloc; |
|
int starts[NUM_LEVELS * MAX_NESTING]; |
|
int starts_base; |
|
int future_jumps[MAX_NESTING]; |
|
int num_jumps; |
|
unsigned char ch = '\0'; |
|
unsigned char *pattern; |
|
unsigned char *translate; |
|
int next_register; |
|
int paren_depth; |
|
int num_open_registers; |
|
int open_registers[RE_NREGS]; |
|
int beginning_context; |
|
|
|
if (!re_compile_initialized) |
|
re_compile_initialize(); |
|
bufp->used = 0; |
|
bufp->fastmap_accurate = 0; |
|
bufp->uses_registers = 1; |
|
bufp->num_registers = 1; |
|
translate = bufp->translate; |
|
pattern = bufp->buffer; |
|
alloc = bufp->allocated; |
|
if (alloc == 0 || pattern == NULL) |
|
{ |
|
alloc = 256; |
|
pattern = malloc(alloc); |
|
if (!pattern) |
|
goto out_of_memory; |
|
} |
|
pattern_offset = 0; |
|
starts_base = 0; |
|
num_jumps = 0; |
|
current_level = 0; |
|
SET_LEVEL_START; |
|
num_open_registers = 0; |
|
next_register = 1; |
|
paren_depth = 0; |
|
beginning_context = 1; |
|
op = -1; |
|
/* we use Rend dummy to ensure that pending jumps are updated |
|
(due to low priority of Rend) before exiting the loop. */ |
|
pos = 0; |
|
while (op != Rend) |
|
{ |
|
if (pos >= size) |
|
op = Rend; |
|
else |
|
{ |
|
NEXTCHAR(ch); |
|
if (translate) |
|
ch = translate[(unsigned char)ch]; |
|
op = regexp_plain_ops[(unsigned char)ch]; |
|
if (op == Rquote) |
|
{ |
|
NEXTCHAR(ch); |
|
op = regexp_quoted_ops[(unsigned char)ch]; |
|
if (op == Rnormal && regexp_ansi_sequences) |
|
ANSI_TRANSLATE(ch); |
|
} |
|
} |
|
level = regexp_precedences[op]; |
|
/* printf("ch='%c' op=%d level=%d current_level=%d |
|
curlevstart=%d\n", ch, op, level, current_level, |
|
CURRENT_LEVEL_START); */ |
|
if (level > current_level) |
|
{ |
|
for (current_level++; current_level < level; current_level++) |
|
SET_LEVEL_START; |
|
SET_LEVEL_START; |
|
} |
|
else |
|
if (level < current_level) |
|
{ |
|
current_level = level; |
|
for (;num_jumps > 0 && |
|
future_jumps[num_jumps-1] >= CURRENT_LEVEL_START; |
|
num_jumps--) |
|
PUT_ADDR(future_jumps[num_jumps-1], pattern_offset); |
|
} |
|
switch (op) |
|
{ |
|
case Rend: |
|
{ |
|
break; |
|
} |
|
case Rnormal: |
|
{ |
|
normal_char: |
|
opcode = Cexact; |
|
store_opcode_and_arg: /* opcode & ch must be set */ |
|
SET_LEVEL_START; |
|
ALLOC(2); |
|
STORE(opcode); |
|
STORE(ch); |
|
break; |
|
} |
|
case Ranychar: |
|
{ |
|
opcode = Canychar; |
|
store_opcode: |
|
SET_LEVEL_START; |
|
ALLOC(1); |
|
STORE(opcode); |
|
break; |
|
} |
|
case Rquote: |
|
{ |
|
Py_FatalError("Rquote"); |
|
/*NOTREACHED*/ |
|
} |
|
case Rbol: |
|
{ |
|
if (!beginning_context) { |
|
if (regexp_context_indep_ops) |
|
goto op_error; |
|
else |
|
goto normal_char; |
|
} |
|
opcode = Cbol; |
|
goto store_opcode; |
|
} |
|
case Reol: |
|
{ |
|
if (!((pos >= size) || |
|
((regexp_syntax & RE_NO_BK_VBAR) ? |
|
(regex[pos] == '\174') : |
|
(pos+1 < size && regex[pos] == '\134' && |
|
regex[pos+1] == '\174')) || |
|
((regexp_syntax & RE_NO_BK_PARENS)? |
|
(regex[pos] == ')'): |
|
(pos+1 < size && regex[pos] == '\134' && |
|
regex[pos+1] == ')')))) { |
|
if (regexp_context_indep_ops) |
|
goto op_error; |
|
else |
|
goto normal_char; |
|
} |
|
opcode = Ceol; |
|
goto store_opcode; |
|
/* NOTREACHED */ |
|
break; |
|
} |
|
case Roptional: |
|
{ |
|
if (beginning_context) { |
|
if (regexp_context_indep_ops) |
|
goto op_error; |
|
else |
|
goto normal_char; |
|
} |
|
if (CURRENT_LEVEL_START == pattern_offset) |
|
break; /* ignore empty patterns for ? */ |
|
ALLOC(3); |
|
INSERT_JUMP(CURRENT_LEVEL_START, Cfailure_jump, |
|
pattern_offset + 3); |
|
break; |
|
} |
|
case Rstar: |
|
case Rplus: |
|
{ |
|
if (beginning_context) { |
|
if (regexp_context_indep_ops) |
|
goto op_error; |
|
else |
|
goto normal_char; |
|
} |
|
if (CURRENT_LEVEL_START == pattern_offset) |
|
break; /* ignore empty patterns for + and * */ |
|
ALLOC(9); |
|
INSERT_JUMP(CURRENT_LEVEL_START, Cfailure_jump, |
|
pattern_offset + 6); |
|
INSERT_JUMP(pattern_offset, Cstar_jump, CURRENT_LEVEL_START); |
|
if (op == Rplus) /* jump over initial failure_jump */ |
|
INSERT_JUMP(CURRENT_LEVEL_START, Cdummy_failure_jump, |
|
CURRENT_LEVEL_START + 6); |
|
break; |
|
} |
|
case Ror: |
|
{ |
|
ALLOC(6); |
|
INSERT_JUMP(CURRENT_LEVEL_START, Cfailure_jump, |
|
pattern_offset + 6); |
|
if (num_jumps >= MAX_NESTING) |
|
goto too_complex; |
|
STORE(Cjump); |
|
future_jumps[num_jumps++] = pattern_offset; |
|
STORE(0); |
|
STORE(0); |
|
SET_LEVEL_START; |
|
break; |
|
} |
|
case Ropenpar: |
|
{ |
|
SET_LEVEL_START; |
|
if (next_register < RE_NREGS) |
|
{ |
|
bufp->uses_registers = 1; |
|
ALLOC(2); |
|
STORE(Cstart_memory); |
|
STORE(next_register); |
|
open_registers[num_open_registers++] = next_register; |
|
bufp->num_registers++; |
|
next_register++; |
|
} |
|
paren_depth++; |
|
PUSH_LEVEL_STARTS; |
|
current_level = 0; |
|
SET_LEVEL_START; |
|
break; |
|
} |
|
case Rclosepar: |
|
{ |
|
if (paren_depth <= 0) |
|
goto parenthesis_error; |
|
POP_LEVEL_STARTS; |
|
current_level = regexp_precedences[Ropenpar]; |
|
paren_depth--; |
|
if (paren_depth < num_open_registers) |
|
{ |
|
bufp->uses_registers = 1; |
|
ALLOC(2); |
|
STORE(Cend_memory); |
|
num_open_registers--; |
|
STORE(open_registers[num_open_registers]); |
|
} |
|
break; |
|
} |
|
case Rmemory: |
|
{ |
|
if (ch == '0') |
|
goto bad_match_register; |
|
assert(ch >= '0' && ch <= '9'); |
|
bufp->uses_registers = 1; |
|
opcode = Cmatch_memory; |
|
ch -= '0'; |
|
goto store_opcode_and_arg; |
|
} |
|
case Rextended_memory: |
|
{ |
|
NEXTCHAR(ch); |
|
if (ch < '0' || ch > '9') |
|
goto bad_match_register; |
|
NEXTCHAR(a); |
|
if (a < '0' || a > '9') |
|
goto bad_match_register; |
|
ch = 10 * (a - '0') + ch - '0'; |
|
if (ch == 0 || ch >= RE_NREGS) |
|
goto bad_match_register; |
|
bufp->uses_registers = 1; |
|
opcode = Cmatch_memory; |
|
goto store_opcode_and_arg; |
|
} |
|
case Ropenset: |
|
{ |
|
int complement; |
|
int prev; |
|
int offset; |
|
int range; |
|
int firstchar; |
|
|
|
SET_LEVEL_START; |
|
ALLOC(1+256/8); |
|
STORE(Cset); |
|
offset = pattern_offset; |
|
for (a = 0; a < 256/8; a++) |
|
STORE(0); |
|
NEXTCHAR(ch); |
|
if (translate) |
|
ch = translate[(unsigned char)ch]; |
|
if (ch == '\136') |
|
{ |
|
complement = 1; |
|
NEXTCHAR(ch); |
|
if (translate) |
|
ch = translate[(unsigned char)ch]; |
|
} |
|
else |
|
complement = 0; |
|
prev = -1; |
|
range = 0; |
|
firstchar = 1; |
|
while (ch != '\135' || firstchar) |
|
{ |
|
firstchar = 0; |
|
if (regexp_ansi_sequences && ch == '\134') |
|
{ |
|
NEXTCHAR(ch); |
|
ANSI_TRANSLATE(ch); |
|
} |
|
if (range) |
|
{ |
|
for (a = prev; a <= (int)ch; a++) |
|
SETBIT(pattern, offset, a); |
|
prev = -1; |
|
range = 0; |
|
} |
|
else |
|
if (prev != -1 && ch == '-') |
|
range = 1; |
|
else |
|
{ |
|
SETBIT(pattern, offset, ch); |
|
prev = ch; |
|
} |
|
NEXTCHAR(ch); |
|
if (translate) |
|
ch = translate[(unsigned char)ch]; |
|
} |
|
if (range) |
|
SETBIT(pattern, offset, '-'); |
|
if (complement) |
|
{ |
|
for (a = 0; a < 256/8; a++) |
|
pattern[offset+a] ^= 0xff; |
|
} |
|
break; |
|
} |
|
case Rbegbuf: |
|
{ |
|
opcode = Cbegbuf; |
|
goto store_opcode; |
|
} |
|
case Rendbuf: |
|
{ |
|
opcode = Cendbuf; |
|
goto store_opcode; |
|
} |
|
case Rwordchar: |
|
{ |
|
opcode = Csyntaxspec; |
|
ch = Sword; |
|
goto store_opcode_and_arg; |
|
} |
|
case Rnotwordchar: |
|
{ |
|
opcode = Cnotsyntaxspec; |
|
ch = Sword; |
|
goto store_opcode_and_arg; |
|
} |
|
case Rwordbeg: |
|
{ |
|
opcode = Cwordbeg; |
|
goto store_opcode; |
|
} |
|
case Rwordend: |
|
{ |
|
opcode = Cwordend; |
|
goto store_opcode; |
|
} |
|
case Rwordbound: |
|
{ |
|
opcode = Cwordbound; |
|
goto store_opcode; |
|
} |
|
case Rnotwordbound: |
|
{ |
|
opcode = Cnotwordbound; |
|
goto store_opcode; |
|
} |
|
default: |
|
{ |
|
abort(); |
|
} |
|
} |
|
beginning_context = (op == Ropenpar || op == Ror); |
|
} |
|
if (starts_base != 0) |
|
goto parenthesis_error; |
|
assert(num_jumps == 0); |
|
ALLOC(1); |
|
STORE(Cend); |
|
SET_FIELDS; |
|
if(!re_optimize(bufp)) |
|
return "Optimization error"; |
|
return NULL; |
|
|
|
op_error: |
|
SET_FIELDS; |
|
return "Badly placed special character"; |
|
|
|
bad_match_register: |
|
SET_FIELDS; |
|
return "Bad match register number"; |
|
|
|
hex_error: |
|
SET_FIELDS; |
|
return "Bad hexadecimal number"; |
|
|
|
parenthesis_error: |
|
SET_FIELDS; |
|
return "Badly placed parenthesis"; |
|
|
|
out_of_memory: |
|
SET_FIELDS; |
|
return "Out of memory"; |
|
|
|
ends_prematurely: |
|
SET_FIELDS; |
|
return "Regular expression ends prematurely"; |
|
|
|
too_complex: |
|
SET_FIELDS; |
|
return "Regular expression too complex"; |
|
} |
|
|
|
#undef CHARAT |
|
#undef NEXTCHAR |
|
#undef GETHEX |
|
#undef ALLOC |
|
#undef STORE |
|
#undef CURRENT_LEVEL_START |
|
#undef SET_LEVEL_START |
|
#undef PUSH_LEVEL_STARTS |
|
#undef POP_LEVEL_STARTS |
|
#undef PUT_ADDR |
|
#undef INSERT_JUMP |
|
#undef SETBIT |
|
#undef SET_FIELDS |
|
|
|
#define PREFETCH if (text == textend) goto fail |
|
|
|
#define NEXTCHAR(var) \ |
|
PREFETCH; \ |
|
var = (unsigned char)*text++; \ |
|
if (translate) \ |
|
var = translate[var] |
|
|
|
int re_match(regexp_t bufp, unsigned char *string, int size, int pos, |
|
regexp_registers_t old_regs) |
|
{ |
|
unsigned char *code; |
|
unsigned char *translate; |
|
unsigned char *text; |
|
unsigned char *textstart; |
|
unsigned char *textend; |
|
int a; |
|
int b; |
|
int ch; |
|
int reg; |
|
int match_end; |
|
unsigned char *regstart; |
|
unsigned char *regend; |
|
int regsize; |
|
match_state state; |
|
|
|
assert(pos >= 0 && size >= 0); |
|
assert(pos <= size); |
|
|
|
text = string + pos; |
|
textstart = string; |
|
textend = string + size; |
|
|
|
code = bufp->buffer; |
|
|
|
translate = bufp->translate; |
|
|
|
NEW_STATE(state, bufp->num_registers); |
|
|
|
continue_matching: |
|
switch (*code++) |
|
{ |
|
case Cend: |
|
{ |
|
match_end = text - textstart; |
|
if (old_regs) |
|
{ |
|
old_regs->start[0] = pos; |
|
old_regs->end[0] = match_end; |
|
if (!bufp->uses_registers) |
|
{ |
|
for (a = 1; a < RE_NREGS; a++) |
|
{ |
|
old_regs->start[a] = -1; |
|
old_regs->end[a] = -1; |
|
} |
|
} |
|
else |
|
{ |
|
for (a = 1; a < bufp->num_registers; a++) |
|
{ |
|
if ((GET_REG_START(state, a) == NULL) || |
|
(GET_REG_END(state, a) == NULL)) |
|
{ |
|
old_regs->start[a] = -1; |
|
old_regs->end[a] = -1; |
|
continue; |
|
} |
|
old_regs->start[a] = GET_REG_START(state, a) - textstart; |
|
old_regs->end[a] = GET_REG_END(state, a) - textstart; |
|
} |
|
for (; a < RE_NREGS; a++) |
|
{ |
|
old_regs->start[a] = -1; |
|
old_regs->end[a] = -1; |
|
} |
|
} |
|
} |
|
FREE_STATE(state); |
|
return match_end - pos; |
|
} |
|
case Cbol: |
|
{ |
|
if (text == textstart || text[-1] == '\n') |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Ceol: |
|
{ |
|
if (text == textend || *text == '\n') |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Cset: |
|
{ |
|
NEXTCHAR(ch); |
|
if (code[ch/8] & (1<<(ch & 7))) |
|
{ |
|
code += 256/8; |
|
goto continue_matching; |
|
} |
|
goto fail; |
|
} |
|
case Cexact: |
|
{ |
|
NEXTCHAR(ch); |
|
if (ch != (unsigned char)*code++) |
|
goto fail; |
|
goto continue_matching; |
|
} |
|
case Canychar: |
|
{ |
|
NEXTCHAR(ch); |
|
if (ch == '\n') |
|
goto fail; |
|
goto continue_matching; |
|
} |
|
case Cstart_memory: |
|
{ |
|
reg = *code++; |
|
SET_REG_START(state, reg, text, goto error); |
|
goto continue_matching; |
|
} |
|
case Cend_memory: |
|
{ |
|
reg = *code++; |
|
SET_REG_END(state, reg, text, goto error); |
|
goto continue_matching; |
|
} |
|
case Cmatch_memory: |
|
{ |
|
reg = *code++; |
|
regstart = GET_REG_START(state, reg); |
|
regend = GET_REG_END(state, reg); |
|
if ((regstart == NULL) || (regend == NULL)) |
|
goto fail; /* or should we just match nothing? */ |
|
regsize = regend - regstart; |
|
|
|
if (regsize > (textend - text)) |
|
goto fail; |
|
if(translate) |
|
{ |
|
for (; regstart < regend; regstart++, text++) |
|
if (translate[*regstart] != translate[*text]) |
|
goto fail; |
|
} |
|
else |
|
for (; regstart < regend; regstart++, text++) |
|
if (*regstart != *text) |
|
goto fail; |
|
goto continue_matching; |
|
} |
|
case Cupdate_failure_jump: |
|
{ |
|
UPDATE_FAILURE(state, text, goto error); |
|
/* fall to next case */ |
|
} |
|
/* treat Cstar_jump just like Cjump if it hasn't been optimized */ |
|
case Cstar_jump: |
|
case Cjump: |
|
{ |
|
a = (unsigned char)*code++; |
|
a |= (unsigned char)*code++ << 8; |
|
code += (int)SHORT(a); |
|
if (code<bufp->buffer || bufp->buffer+bufp->used<code) { |
|
PyErr_SetString(PyExc_SystemError, "Regex VM jump out of bounds (Cjump)"); |
|
FREE_STATE(state); |
|
return -2; |
|
} |
|
goto continue_matching; |
|
} |
|
case Cdummy_failure_jump: |
|
{ |
|
unsigned char *failuredest; |
|
|
|
a = (unsigned char)*code++; |
|
a |= (unsigned char)*code++ << 8; |
|
a = (int)SHORT(a); |
|
assert(*code == Cfailure_jump); |
|
b = (unsigned char)code[1]; |
|
b |= (unsigned char)code[2] << 8; |
|
failuredest = code + (int)SHORT(b) + 3; |
|
if (failuredest<bufp->buffer || bufp->buffer+bufp->used < failuredest) { |
|
PyErr_SetString(PyExc_SystemError, "Regex VM jump out of bounds (Cdummy_failure_jump failuredest)"); |
|
FREE_STATE(state); |
|
return -2; |
|
} |
|
PUSH_FAILURE(state, failuredest, NULL, goto error); |
|
code += a; |
|
if (code<bufp->buffer || bufp->buffer+bufp->used < code) { |
|
PyErr_SetString(PyExc_SystemError, "Regex VM jump out of bounds (Cdummy_failure_jump code)"); |
|
FREE_STATE(state); |
|
return -2; |
|
} |
|
goto continue_matching; |
|
} |
|
case Cfailure_jump: |
|
{ |
|
a = (unsigned char)*code++; |
|
a |= (unsigned char)*code++ << 8; |
|
a = (int)SHORT(a); |
|
if (code+a<bufp->buffer || bufp->buffer+bufp->used < code+a) { |
|
PyErr_SetString(PyExc_SystemError, "Regex VM jump out of bounds (Cfailure_jump)"); |
|
FREE_STATE(state); |
|
return -2; |
|
} |
|
PUSH_FAILURE(state, code + a, text, goto error); |
|
goto continue_matching; |
|
} |
|
case Crepeat1: |
|
{ |
|
unsigned char *pinst; |
|
a = (unsigned char)*code++; |
|
a |= (unsigned char)*code++ << 8; |
|
a = (int)SHORT(a); |
|
pinst = code + a; |
|
if (pinst<bufp->buffer || bufp->buffer+bufp->used<pinst) { |
|
PyErr_SetString(PyExc_SystemError, "Regex VM jump out of bounds (Crepeat1)"); |
|
FREE_STATE(state); |
|
return -2; |
|
} |
|
/* pinst is sole instruction in loop, and it matches a |
|
* single character. Since Crepeat1 was originally a |
|
* Cupdate_failure_jump, we also know that backtracking |
|
* is useless: so long as the single-character |
|
* expression matches, it must be used. Also, in the |
|
* case of +, we've already matched one character, so + |
|
* can't fail: nothing here can cause a failure. */ |
|
switch (*pinst++) |
|
{ |
|
case Cset: |
|
{ |
|
if (translate) |
|
{ |
|
while (text < textend) |
|
{ |
|
ch = translate[(unsigned char)*text]; |
|
if (pinst[ch/8] & (1<<(ch & 7))) |
|
text++; |
|
else |
|
break; |
|
} |
|
} |
|
else |
|
{ |
|
while (text < textend) |
|
{ |
|
ch = (unsigned char)*text; |
|
if (pinst[ch/8] & (1<<(ch & 7))) |
|
text++; |
|
else |
|
break; |
|
} |
|
} |
|
break; |
|
} |
|
case Cexact: |
|
{ |
|
ch = (unsigned char)*pinst; |
|
if (translate) |
|
{ |
|
while (text < textend && |
|
translate[(unsigned char)*text] == ch) |
|
text++; |
|
} |
|
else |
|
{ |
|
while (text < textend && (unsigned char)*text == ch) |
|
text++; |
|
} |
|
break; |
|
} |
|
case Canychar: |
|
{ |
|
while (text < textend && (unsigned char)*text != '\n') |
|
text++; |
|
break; |
|
} |
|
case Csyntaxspec: |
|
{ |
|
a = (unsigned char)*pinst; |
|
if (translate) |
|
{ |
|
while (text < textend && |
|
(SYNTAX(translate[*text]) & a) ) |
|
text++; |
|
} |
|
else |
|
{ |
|
while (text < textend && (SYNTAX(*text) & a) ) |
|
text++; |
|
} |
|
break; |
|
} |
|
case Cnotsyntaxspec: |
|
{ |
|
a = (unsigned char)*pinst; |
|
if (translate) |
|
{ |
|
while (text < textend && |
|
!(SYNTAX(translate[*text]) & a) ) |
|
text++; |
|
} |
|
else |
|
{ |
|
while (text < textend && !(SYNTAX(*text) & a) ) |
|
text++; |
|
} |
|
break; |
|
} |
|
default: |
|
{ |
|
FREE_STATE(state); |
|
PyErr_SetString(PyExc_SystemError, "Unknown regex opcode: memory corrupted?"); |
|
return -2; |
|
/*NOTREACHED*/ |
|
} |
|
} |
|
/* due to the funky way + and * are compiled, the top |
|
* failure- stack entry at this point is actually a |
|
* success entry -- update it & pop it */ |
|
UPDATE_FAILURE(state, text, goto error); |
|
goto fail; /* i.e., succeed <wink/sigh> */ |
|
} |
|
case Cbegbuf: |
|
{ |
|
if (text == textstart) |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Cendbuf: |
|
{ |
|
if (text == textend) |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Cwordbeg: |
|
{ |
|
if (text == textend) |
|
goto fail; |
|
if (!(SYNTAX(*text) & Sword)) |
|
goto fail; |
|
if (text == textstart) |
|
goto continue_matching; |
|
if (!(SYNTAX(text[-1]) & Sword)) |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Cwordend: |
|
{ |
|
if (text == textstart) |
|
goto fail; |
|
if (!(SYNTAX(text[-1]) & Sword)) |
|
goto fail; |
|
if (text == textend) |
|
goto continue_matching; |
|
if (!(SYNTAX(*text) & Sword)) |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Cwordbound: |
|
{ |
|
/* Note: as in gnu regexp, this also matches at the |
|
* beginning and end of buffer. */ |
|
|
|
if (text == textstart || text == textend) |
|
goto continue_matching; |
|
if ((SYNTAX(text[-1]) & Sword) ^ (SYNTAX(*text) & Sword)) |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Cnotwordbound: |
|
{ |
|
/* Note: as in gnu regexp, this never matches at the |
|
* beginning and end of buffer. */ |
|
if (text == textstart || text == textend) |
|
goto fail; |
|
if (!((SYNTAX(text[-1]) & Sword) ^ (SYNTAX(*text) & Sword))) |
|
goto continue_matching; |
|
goto fail; |
|
} |
|
case Csyntaxspec: |
|
{ |
|
NEXTCHAR(ch); |
|
if (!(SYNTAX(ch) & (unsigned char)*code++)) |
|
goto fail; |
|
goto continue_matching; |
|
} |
|
case Cnotsyntaxspec: |
|
{ |
|
NEXTCHAR(ch); |
|
if (SYNTAX(ch) & (unsigned char)*code++) |
|
goto fail; |
|
goto continue_matching; |
|
} |
|
default: |
|
{ |
|
FREE_STATE(state); |
|
PyErr_SetString(PyExc_SystemError, "Unknown regex opcode: memory corrupted?"); |
|
return -2; |
|
/*NOTREACHED*/ |
|
} |
|
} |
|
|
|
|
|
|
|
#if 0 /* This line is never reached --Guido */ |
|
abort(); |
|
#endif |
|
/* |
|
*NOTREACHED |
|
*/ |
|
|
|
/* Using "break;" in the above switch statement is equivalent to "goto fail;" */ |
|
fail: |
|
POP_FAILURE(state, code, text, goto done_matching, goto error); |
|
goto continue_matching; |
|
|
|
done_matching: |
|
/* if(translated != NULL) */ |
|
/* free(translated); */ |
|
FREE_STATE(state); |
|
return -1; |
|
|
|
error: |
|
/* if (translated != NULL) */ |
|
/* free(translated); */ |
|
FREE_STATE(state); |
|
return -2; |
|
} |
|
|
|
|
|
#undef PREFETCH |
|
#undef NEXTCHAR |
|
|
|
int re_search(regexp_t bufp, unsigned char *string, int size, int pos, |
|
int range, regexp_registers_t regs) |
|
{ |
|
unsigned char *fastmap; |
|
unsigned char *translate; |
|
unsigned char *text; |
|
unsigned char *partstart; |
|
unsigned char *partend; |
|
int dir; |
|
int ret; |
|
unsigned char anchor; |
|
|
|
assert(size >= 0 && pos >= 0); |
|
assert(pos + range >= 0 && pos + range <= size); /* Bugfix by ylo */ |
|
|
|
fastmap = bufp->fastmap; |
|
translate = bufp->translate; |
|
if (fastmap && !bufp->fastmap_accurate) { |
|
re_compile_fastmap(bufp); |
|
if (PyErr_Occurred()) return -2; |
|
} |
|
|
|
anchor = bufp->anchor; |
|
if (bufp->can_be_null == 1) /* can_be_null == 2: can match null at eob */ |
|
fastmap = NULL; |
|
|
|
if (range < 0) |
|
{ |
|
dir = -1; |
|
range = -range; |
|
} |
|
else |
|
dir = 1; |
|
|
|
if (anchor == 2) { |
|
if (pos != 0) |
|
return -1; |
|
else |
|
range = 0; |
|
} |
|
|
|
for (; range >= 0; range--, pos += dir) |
|
{ |
|
if (fastmap) |
|
{ |
|
if (dir == 1) |
|
{ /* searching forwards */ |
|
|
|
text = string + pos; |
|
partend = string + size; |
|
partstart = text; |
|
if (translate) |
|
while (text != partend && |
|
!fastmap[(unsigned char) translate[(unsigned char)*text]]) |
|
text++; |
|
else |
|
while (text != partend && !fastmap[(unsigned char)*text]) |
|
text++; |
|
pos += text - partstart; |
|
range -= text - partstart; |
|
if (pos == size && bufp->can_be_null == 0) |
|
return -1; |
|
} |
|
else |
|
{ /* searching backwards */ |
|
text = string + pos; |
|
partstart = string + pos - range; |
|
partend = text; |
|
if (translate) |
|
while (text != partstart && |
|
!fastmap[(unsigned char) |
|
translate[(unsigned char)*text]]) |
|
text--; |
|
else |
|
while (text != partstart && |
|
!fastmap[(unsigned char)*text]) |
|
text--; |
|
pos -= partend - text; |
|
range -= partend - text; |
|
} |
|
} |
|
if (anchor == 1) |
|
{ /* anchored to begline */ |
|
if (pos > 0 && (string[pos - 1] != '\n')) |
|
continue; |
|
} |
|
assert(pos >= 0 && pos <= size); |
|
ret = re_match(bufp, string, size, pos, regs); |
|
if (ret >= 0) |
|
return pos; |
|
if (ret == -2) |
|
return -2; |
|
} |
|
return -1; |
|
} |
|
|
|
/* |
|
** Local Variables: |
|
** mode: c |
|
** c-file-style: "python" |
|
** End: |
|
*/
|
|
|