/* * $Id: GNUregex.c,v 1.13 2005/05/17 16:56:36 hno Exp $ */ /* Extended regular expression matching and search library, * version 0.12. * (Implements POSIX draft P10003.2/D11.2, except for * internationalization features.) * * Copyright (C) 1993 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 * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. */ /* AIX requires this to be the first thing in the file. */ #if defined (_AIX) && !defined (REGEX_MALLOC) #pragma alloca #endif #ifndef _GNU_SOURCE #define _GNU_SOURCE 1 #endif #include "config.h" #if !HAVE_ALLOCA #define REGEX_MALLOC 1 #endif /* The `emacs' switch turns on certain matching commands * that make sense only in Emacs. */ #ifdef emacs #include "lisp.h" #include "buffer.h" #include "syntax.h" /* Emacs uses `NULL' as a predicate. */ #undef NULL #else /* not emacs */ /* We used to test for `BSTRING' here, but only GCC and Emacs define * `BSTRING', as far as I know, and neither of them use this code. */ #if HAVE_STRING_H || STDC_HEADERS #include #else #include #endif #ifdef STDC_HEADERS #include #else char *malloc(); char *realloc(); #endif /* Define the syntax stuff for \<, \>, etc. */ /* This must be nonzero for the wordchar and notwordchar pattern * commands in re_match_2. */ #ifndef Sword #define Sword 1 #endif #ifdef SYNTAX_TABLE extern char *re_syntax_table; #else /* not SYNTAX_TABLE */ /* How many characters in the character set. */ #define CHAR_SET_SIZE 256 static char re_syntax_table[CHAR_SET_SIZE]; static void init_syntax_once(void) { register int c; static int done = 0; if (done) return; memset(re_syntax_table, 0, sizeof re_syntax_table); for (c = 'a'; c <= 'z'; c++) re_syntax_table[c] = Sword; for (c = 'A'; c <= 'Z'; c++) re_syntax_table[c] = Sword; for (c = '0'; c <= '9'; c++) re_syntax_table[c] = Sword; re_syntax_table['_'] = Sword; done = 1; } #endif /* not SYNTAX_TABLE */ #define SYNTAX(c) re_syntax_table[c] #endif /* not emacs */ /* Get the interface, including the syntax bits. */ #include "GNUregex.h" /* isalpha etc. are used for the character classes. */ #include #ifndef isascii #define isascii(c) 1 #endif #ifdef isblank #define ISBLANK(c) (isascii (c) && isblank (c)) #else #define ISBLANK(c) ((c) == ' ' || (c) == '\t') #endif #ifdef isgraph #define ISGRAPH(c) (isascii (c) && isgraph (c)) #else #define ISGRAPH(c) (isascii (c) && isprint (c) && !isspace (c)) #endif #define ISPRINT(c) (isascii (c) && isprint (c)) #define ISDIGIT(c) (isascii (c) && isdigit (c)) #define ISALNUM(c) (isascii (c) && isalnum (c)) #define ISALPHA(c) (isascii (c) && isalpha (c)) #define ISCNTRL(c) (isascii (c) && iscntrl (c)) #define ISLOWER(c) (isascii (c) && islower (c)) #define ISPUNCT(c) (isascii (c) && ispunct (c)) #define ISSPACE(c) (isascii (c) && isspace (c)) #define ISUPPER(c) (isascii (c) && isupper (c)) #define ISXDIGIT(c) (isascii (c) && isxdigit (c)) #ifndef NULL #define NULL 0 #endif /* We remove any previous definition of `SIGN_EXTEND_CHAR', * since ours (we hope) works properly with all combinations of * machines, compilers, `char' and `unsigned char' argument types. * (Per Bothner suggested the basic approach.) */ #undef SIGN_EXTEND_CHAR #ifdef __STDC__ #define SIGN_EXTEND_CHAR(c) ((signed char) (c)) #else /* not __STDC__ */ /* As in Harbison and Steele. */ #define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128) #endif /* Should we use malloc or alloca? If REGEX_MALLOC is not defined, we * use `alloca' instead of `malloc'. This is because using malloc in * re_search* or re_match* could cause memory leaks when C-g is used in * Emacs; also, malloc is slower and causes storage fragmentation. On * the other hand, malloc is more portable, and easier to debug. * * Because we sometimes use alloca, some routines have to be macros, * not functions -- `alloca'-allocated space disappears at the end of the * function it is called in. */ #ifdef REGEX_MALLOC #define REGEX_ALLOCATE malloc #define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize) #else /* not REGEX_MALLOC */ /* Emacs already defines alloca, sometimes. */ #ifndef alloca /* Make alloca work the best possible way. */ #ifdef __GNUC__ #define alloca __builtin_alloca #else /* not __GNUC__ */ #if HAVE_ALLOCA_H #include #else /* not __GNUC__ or HAVE_ALLOCA_H */ #ifndef _AIX /* Already did AIX, up at the top. */ char *alloca(); #endif /* not _AIX */ #endif /* not HAVE_ALLOCA_H */ #endif /* not __GNUC__ */ #endif /* not alloca */ #define REGEX_ALLOCATE alloca /* Assumes a `char *destination' variable. */ #define REGEX_REALLOCATE(source, osize, nsize) \ (destination = (char *) alloca (nsize), \ xmemcpy (destination, source, osize), \ destination) #endif /* not REGEX_MALLOC */ /* True if `size1' is non-NULL and PTR is pointing anywhere inside * `string1' or just past its end. This works if PTR is NULL, which is * a good thing. */ #define FIRST_STRING_P(ptr) \ (size1 && string1 <= (ptr) && (ptr) <= string1 + size1) /* (Re)Allocate N items of type T using malloc, or fail. */ #define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t))) #define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t))) #define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t))) #define BYTEWIDTH 8 /* In bits. */ #define STREQ(s1, s2) ((strcmp (s1, s2) == 0)) #define MAX(a, b) ((a) > (b) ? (a) : (b)) #define MIN(a, b) ((a) < (b) ? (a) : (b)) typedef char boolean; #define false 0 #define true 1 /* These are the command codes that appear in compiled regular * expressions. Some opcodes are followed by argument bytes. A * command code can specify any interpretation whatsoever for its * arguments. Zero bytes may appear in the compiled regular expression. * * The value of `exactn' is needed in search.c (search_buffer) in Emacs. * So regex.h defines a symbol `RE_EXACTN_VALUE' to be 1; the value of * `exactn' we use here must also be 1. */ typedef enum { no_op = 0, /* Followed by one byte giving n, then by n literal bytes. */ exactn = 1, /* Matches any (more or less) character. */ anychar, /* Matches any one char belonging to specified set. First * following byte is number of bitmap bytes. Then come bytes * for a bitmap saying which chars are in. Bits in each byte * are ordered low-bit-first. A character is in the set if its * bit is 1. A character too large to have a bit in the map is * automatically not in the set. */ charset, /* Same parameters as charset, but match any character that is * not one of those specified. */ charset_not, /* 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.) */ 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.) */ stop_memory, /* Match a duplicate of something remembered. Followed by one * byte containing the register number. */ duplicate, /* Fail unless at beginning of line. */ begline, /* Fail unless at end of line. */ endline, /* Succeeds if at beginning of buffer (if emacs) or at beginning * of string to be matched (if not). */ begbuf, /* Analogously, for end of buffer/string. */ endbuf, /* 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, /* Like on_failure_jump, but pushes a placeholder instead of the * 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, /* Followed by two-byte relative address and two-byte number n. * After matching N times, jump to the address upon failure. */ succeed_n, /* Followed by two-byte relative address, and two-byte number n. * Jump to the address N times, then fail. */ jump_n, /* Set the following two-byte relative address to the * subsequent two-byte number. The address *includes* the two * bytes of number. */ set_number_at, wordchar, /* Matches any word-constituent character. */ notwordchar, /* Matches any char that is not a word-constituent. */ wordbeg, /* Succeeds if at word beginning. */ wordend, /* Succeeds if at word end. */ wordbound, /* Succeeds if at a word boundary. */ notwordbound /* Succeeds if not at a word boundary. */ #ifdef emacs ,before_dot, /* Succeeds if before point. */ at_dot, /* Succeeds if at point. */ after_dot, /* Succeeds if after point. */ /* Matches any character whose syntax is specified. Followed by * a byte which contains a syntax code, e.g., Sword. */ syntaxspec, /* Matches any character whose syntax is not that specified. */ notsyntaxspec #endif /* emacs */ } re_opcode_t; /* Common operations on the compiled pattern. */ /* Store NUMBER in two contiguous bytes starting at DESTINATION. */ #define STORE_NUMBER(destination, number) \ do { \ (destination)[0] = (number) & 0377; \ (destination)[1] = (number) >> 8; \ } while (0) /* Same as STORE_NUMBER, except increment DESTINATION to * the byte after where the number is stored. Therefore, DESTINATION * must be an lvalue. */ #define STORE_NUMBER_AND_INCR(destination, number) \ do { \ STORE_NUMBER (destination, number); \ (destination) += 2; \ } while (0) /* Put into DESTINATION a number stored in two contiguous bytes starting * at SOURCE. */ #define EXTRACT_NUMBER(destination, source) \ do { \ (destination) = *(source) & 0377; \ (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8; \ } while (0) #ifdef DEBUG static void extract_number(dest, source) int *dest; unsigned char *source; { int temp = SIGN_EXTEND_CHAR(*(source + 1)); *dest = *source & 0377; *dest += temp << 8; } #ifndef EXTRACT_MACROS /* To debug the macros. */ #undef EXTRACT_NUMBER #define EXTRACT_NUMBER(dest, src) extract_number (&dest, src) #endif /* not EXTRACT_MACROS */ #endif /* DEBUG */ /* Same as EXTRACT_NUMBER, except increment SOURCE to after the number. * SOURCE must be an lvalue. */ #define EXTRACT_NUMBER_AND_INCR(destination, source) \ do { \ EXTRACT_NUMBER (destination, source); \ (source) += 2; \ } while (0) #ifdef DEBUG static void extract_number_and_incr(destination, source) int *destination; unsigned char **source; { extract_number(destination, *source); *source += 2; } #ifndef EXTRACT_MACROS #undef EXTRACT_NUMBER_AND_INCR #define EXTRACT_NUMBER_AND_INCR(dest, src) \ extract_number_and_incr (&dest, &src) #endif /* not EXTRACT_MACROS */ #endif /* DEBUG */ /* If DEBUG is defined, Regex prints many voluminous messages about what * it is doing (if the variable `debug' is nonzero). If linked with the * main program in `iregex.c', you can enter patterns and strings * interactively. And if linked with the main program in `main.c' and * the other test files, you can run the already-written tests. */ #ifdef DEBUG /* We use standard I/O for debugging. */ #include /* It is useful to test things that ``must'' be true when debugging. */ #include static int debug = 0; #define DEBUG_STATEMENT(e) e #define DEBUG_PRINT1(x) if (debug) printf (x) #define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2) #define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3) #define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4) #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) \ if (debug) print_partial_compiled_pattern (s, e) #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) \ if (debug) print_double_string (w, s1, sz1, s2, sz2) extern void printchar(); /* Print the fastmap in human-readable form. */ void print_fastmap(fastmap) char *fastmap; { unsigned was_a_range = 0; unsigned i = 0; while (i < (1 << BYTEWIDTH)) { if (fastmap[i++]) { was_a_range = 0; printchar(i - 1); while (i < (1 << BYTEWIDTH) && fastmap[i]) { was_a_range = 1; i++; } if (was_a_range) { printf("-"); printchar(i - 1); } } } putchar('\n'); } /* Print a compiled pattern string in human-readable form, starting at * the START pointer into it and ending just before the pointer END. */ void print_partial_compiled_pattern(start, end) unsigned char *start; unsigned char *end; { int mcnt, mcnt2; unsigned char *p = start; unsigned char *pend = end; if (start == NULL) { printf("(null)\n"); return; } /* Loop over pattern commands. */ while (p < pend) { switch ((re_opcode_t) * p++) { case no_op: printf("/no_op"); break; case exactn: mcnt = *p++; printf("/exactn/%d", mcnt); do { putchar('/'); printchar(*p++); } while (--mcnt); break; case start_memory: mcnt = *p++; printf("/start_memory/%d/%d", mcnt, *p++); break; case stop_memory: mcnt = *p++; printf("/stop_memory/%d/%d", mcnt, *p++); break; case duplicate: printf("/duplicate/%d", *p++); break; case anychar: printf("/anychar"); break; case charset: case charset_not: { register int c; printf("/charset%s", (re_opcode_t) * (p - 1) == charset_not ? "_not" : ""); assert(p + *p < pend); for (c = 0; c < *p; c++) { unsigned bit; unsigned char map_byte = p[1 + c]; putchar('/'); for (bit = 0; bit < BYTEWIDTH; bit++) if (map_byte & (1 << bit)) printchar(c * BYTEWIDTH + bit); } p += 1 + *p; break; } case begline: printf("/begline"); break; case endline: printf("/endline"); break; case on_failure_jump: extract_number_and_incr(&mcnt, &p); printf("/on_failure_jump/0/%d", mcnt); break; case on_failure_keep_string_jump: extract_number_and_incr(&mcnt, &p); printf("/on_failure_keep_string_jump/0/%d", mcnt); break; case dummy_failure_jump: extract_number_and_incr(&mcnt, &p); printf("/dummy_failure_jump/0/%d", mcnt); break; case push_dummy_failure: printf("/push_dummy_failure"); break; case maybe_pop_jump: extract_number_and_incr(&mcnt, &p); printf("/maybe_pop_jump/0/%d", mcnt); break; case pop_failure_jump: extract_number_and_incr(&mcnt, &p); printf("/pop_failure_jump/0/%d", mcnt); break; case jump_past_alt: extract_number_and_incr(&mcnt, &p); printf("/jump_past_alt/0/%d", mcnt); break; case jump: extract_number_and_incr(&mcnt, &p); printf("/jump/0/%d", mcnt); break; case succeed_n: extract_number_and_incr(&mcnt, &p); extract_number_and_incr(&mcnt2, &p); printf("/succeed_n/0/%d/0/%d", mcnt, mcnt2); break; case jump_n: extract_number_and_incr(&mcnt, &p); extract_number_and_incr(&mcnt2, &p); printf("/jump_n/0/%d/0/%d", mcnt, mcnt2); break; case set_number_at: extract_number_and_incr(&mcnt, &p); extract_number_and_incr(&mcnt2, &p); printf("/set_number_at/0/%d/0/%d", mcnt, mcnt2); break; case wordbound: printf("/wordbound"); break; case notwordbound: printf("/notwordbound"); break; case wordbeg: printf("/wordbeg"); break; case wordend: printf("/wordend"); #ifdef emacs case before_dot: printf("/before_dot"); break; case at_dot: printf("/at_dot"); break; case after_dot: printf("/after_dot"); break; case syntaxspec: printf("/syntaxspec"); mcnt = *p++; printf("/%d", mcnt); break; case notsyntaxspec: printf("/notsyntaxspec"); mcnt = *p++; printf("/%d", mcnt); break; #endif /* emacs */ case wordchar: printf("/wordchar"); break; case notwordchar: printf("/notwordchar"); break; case begbuf: printf("/begbuf"); break; case endbuf: printf("/endbuf"); break; default: printf("?%d", *(p - 1)); } } printf("/\n"); } void print_compiled_pattern(bufp) struct re_pattern_buffer *bufp; { 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); if (bufp->fastmap_accurate && bufp->fastmap) { printf("fastmap: "); print_fastmap(bufp->fastmap); } printf("re_nsub: %d\t", bufp->re_nsub); printf("regs_alloc: %d\t", bufp->regs_allocated); printf("can_be_null: %d\t", bufp->can_be_null); printf("newline_anchor: %d\n", bufp->newline_anchor); printf("no_sub: %d\t", bufp->no_sub); printf("not_bol: %d\t", bufp->not_bol); printf("not_eol: %d\t", bufp->not_eol); printf("syntax: %d\n", bufp->syntax); /* Perhaps we should print the translate table? */ } void print_double_string(where, string1, size1, string2, size2) const char *where; const char *string1; const char *string2; int size1; int size2; { unsigned this_char; if (where == NULL) printf("(null)"); else { if (FIRST_STRING_P(where)) { for (this_char = where - string1; this_char < size1; this_char++) printchar(string1[this_char]); where = string2; } for (this_char = where - string2; this_char < size2; this_char++) printchar(string2[this_char]); } } #else /* not DEBUG */ #undef assert #define assert(e) #define DEBUG_STATEMENT(e) #define DEBUG_PRINT1(x) #define DEBUG_PRINT2(x1, x2) #define DEBUG_PRINT3(x1, x2, x3) #define DEBUG_PRINT4(x1, x2, x3, x4) #define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) #define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2) #endif /* not DEBUG */ /* Set by `re_set_syntax' to the current regexp syntax to recognize. Can * also be assigned to arbitrarily: each pattern buffer stores its own * syntax, so it can be changed between regex compilations. */ reg_syntax_t re_syntax_options = RE_SYNTAX_EMACS; /* Specify the precise syntax of regexps for compilation. This provides * for compatibility for various utilities which historically have * different, incompatible syntaxes. * * The argument SYNTAX is a bit mask comprised of the various bits * defined in regex.h. We return the old syntax. */ reg_syntax_t re_set_syntax(syntax) reg_syntax_t syntax; { reg_syntax_t ret = re_syntax_options; re_syntax_options = syntax; return ret; } /* This table gives an error message for each of the error codes listed * in regex.h. Obviously the order here has to be same as there. */ static const char *re_error_msg[] = {NULL, /* REG_NOERROR */ "No match", /* REG_NOMATCH */ "Invalid regular expression", /* REG_BADPAT */ "Invalid collation character", /* REG_ECOLLATE */ "Invalid character class name", /* REG_ECTYPE */ "Trailing backslash", /* REG_EESCAPE */ "Invalid back reference", /* REG_ESUBREG */ "Unmatched [ or [^", /* REG_EBRACK */ "Unmatched ( or \\(", /* REG_EPAREN */ "Unmatched \\{", /* REG_EBRACE */ "Invalid content of \\{\\}", /* REG_BADBR */ "Invalid range end", /* REG_ERANGE */ "Memory exhausted", /* REG_ESPACE */ "Invalid preceding regular expression", /* REG_BADRPT */ "Premature end of regular expression", /* REG_EEND */ "Regular expression too big", /* REG_ESIZE */ "Unmatched ) or \\)", /* REG_ERPAREN */ }; /* Subroutine declarations and macros for regex_compile. */ /* Fetch the next character in the uncompiled pattern---translating it * if necessary. Also cast from a signed character in the constant * string passed to us by the user to an unsigned char that we can use * as an array index (in, e.g., `translate'). */ #define PATFETCH(c) \ do {if (p == pend) return REG_EEND; \ c = (unsigned char) *p++; \ if (translate) c = translate[c]; \ } while (0) /* Fetch the next character in the uncompiled pattern, with no * translation. */ #define PATFETCH_RAW(c) \ do {if (p == pend) return REG_EEND; \ c = (unsigned char) *p++; \ } while (0) /* Go backwards one character in the pattern. */ #define PATUNFETCH p-- /* If `translate' is non-null, return translate[D], else just D. We * cast the subscript to translate because some data is declared as * `char *', to avoid warnings when a string constant is passed. But * when we use a character as a subscript we must make it unsigned. */ #define TRANSLATE(d) (translate ? translate[(unsigned char) (d)] : (d)) /* Macros for outputting the compiled pattern into `buffer'. */ /* If the buffer isn't allocated when it comes in, use this. */ #define INIT_BUF_SIZE 32 /* Make sure we have at least N more bytes of space in buffer. */ #define GET_BUFFER_SPACE(n) \ while (b - bufp->buffer + (n) > bufp->allocated) \ EXTEND_BUFFER () /* Make sure we have one more byte of buffer space and then add C to it. */ #define BUF_PUSH(c) \ do { \ GET_BUFFER_SPACE (1); \ *b++ = (unsigned char) (c); \ } while (0) /* Ensure we have two more bytes of buffer space and then append C1 and C2. */ #define BUF_PUSH_2(c1, c2) \ do { \ GET_BUFFER_SPACE (2); \ *b++ = (unsigned char) (c1); \ *b++ = (unsigned char) (c2); \ } while (0) /* As with BUF_PUSH_2, except for three bytes. */ #define BUF_PUSH_3(c1, c2, c3) \ do { \ GET_BUFFER_SPACE (3); \ *b++ = (unsigned char) (c1); \ *b++ = (unsigned char) (c2); \ *b++ = (unsigned char) (c3); \ } while (0) /* Store a jump with opcode OP at LOC to location TO. We store a * relative address offset by the three bytes the jump itself occupies. */ #define STORE_JUMP(op, loc, to) \ store_op1 (op, loc, (to) - (loc) - 3) /* Likewise, for a two-argument jump. */ #define STORE_JUMP2(op, loc, to, arg) \ store_op2 (op, loc, (to) - (loc) - 3, arg) /* Like `STORE_JUMP', but for inserting. Assume `b' is the buffer end. */ #define INSERT_JUMP(op, loc, to) \ insert_op1 (op, loc, (to) - (loc) - 3, b) /* Like `STORE_JUMP2', but for inserting. Assume `b' is the buffer end. */ #define INSERT_JUMP2(op, loc, to, arg) \ insert_op2 (op, loc, (to) - (loc) - 3, arg, b) /* This is not an arbitrary limit: the arguments which represent offsets * into the pattern are two bytes long. So if 2^16 bytes turns out to * be too small, many things would have to change. */ #define MAX_BUF_SIZE (1L << 16) /* Extend the buffer by twice its current size via realloc and * reset the pointers that pointed into the old block to point to the * correct places in the new one. If extending the buffer results in it * being larger than MAX_BUF_SIZE, then flag memory exhausted. */ #define EXTEND_BUFFER() \ do { \ unsigned char *old_buffer = bufp->buffer; \ if (bufp->allocated == MAX_BUF_SIZE) \ return REG_ESIZE; \ bufp->allocated <<= 1; \ if (bufp->allocated > MAX_BUF_SIZE) \ bufp->allocated = MAX_BUF_SIZE; \ bufp->buffer = (unsigned char *) realloc (bufp->buffer, bufp->allocated);\ if (bufp->buffer == NULL) \ return REG_ESPACE; \ /* If the buffer moved, move all the pointers into it. */ \ if (old_buffer != bufp->buffer) \ { \ b = (b - old_buffer) + bufp->buffer; \ begalt = (begalt - old_buffer) + bufp->buffer; \ if (fixup_alt_jump) \ fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\ if (laststart) \ laststart = (laststart - old_buffer) + bufp->buffer; \ if (pending_exact) \ pending_exact = (pending_exact - old_buffer) + bufp->buffer; \ } \ } while (0) /* Since we have one byte reserved for the register number argument to * {start,stop}_memory, the maximum number of groups we can report * things about is what fits in that byte. */ #define MAX_REGNUM 255 /* But patterns can have more than `MAX_REGNUM' registers. We just * ignore the excess. */ typedef unsigned regnum_t; /* Macros for the compile stack. */ /* Since offsets can go either forwards or backwards, this type needs to * be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1. */ typedef int pattern_offset_t; typedef struct { 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; typedef struct { compile_stack_elt_t *stack; unsigned size; unsigned avail; /* Offset of next open position. */ } compile_stack_type; static void store_op1(re_opcode_t op, unsigned char *loc, int arg); static void store_op2( re_opcode_t op, unsigned char *loc, int arg1, int arg2); static void insert_op1(re_opcode_t op, unsigned char *loc, int arg, unsigned char *end); static void insert_op2(re_opcode_t op, unsigned char *loc, int arg1, int arg2, unsigned char *end); static boolean at_begline_loc_p(const char * pattern, const char *p, reg_syntax_t syntax); static boolean at_endline_loc_p(const char *p, const char *pend, int syntax); static boolean group_in_compile_stack(compile_stack_type compile_stack, regnum_t regnum); static reg_errcode_t compile_range(const char **p_ptr, const char *pend, char *translate, reg_syntax_t syntax, unsigned char *b); #define INIT_COMPILE_STACK_SIZE 32 #define COMPILE_STACK_EMPTY (compile_stack.avail == 0) #define COMPILE_STACK_FULL (compile_stack.avail == compile_stack.size) /* The next available element. */ #define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail]) /* Set the bit for character C in a list. */ #define SET_LIST_BIT(c) \ (b[((unsigned char) (c)) / BYTEWIDTH] \ |= 1 << (((unsigned char) c) % BYTEWIDTH)) /* Get the next unsigned number in the uncompiled pattern. */ #define GET_UNSIGNED_NUMBER(num) \ { if (p != pend) \ { \ PATFETCH (c); \ while (ISDIGIT (c)) \ { \ if (num < 0) \ num = 0; \ num = num * 10 + c - '0'; \ if (p == pend) \ break; \ PATFETCH (c); \ } \ } \ } #define CHAR_CLASS_MAX_LENGTH 6 /* Namely, `xdigit'. */ #define IS_CHAR_CLASS(string) \ (STREQ (string, "alpha") || STREQ (string, "upper") \ || STREQ (string, "lower") || STREQ (string, "digit") \ || STREQ (string, "alnum") || STREQ (string, "xdigit") \ || STREQ (string, "space") || STREQ (string, "print") \ || STREQ (string, "punct") || STREQ (string, "graph") \ || STREQ (string, "cntrl") || STREQ (string, "blank")) /* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX. * Returns one of error codes defined in `regex.h', or zero for success. * * Assumes the `allocated' (and perhaps `buffer') and `translate' * fields are set in BUFP on entry. * * If it succeeds, results are put in BUFP (if it returns an error, the * contents of BUFP are undefined): * `buffer' is the compiled pattern; * `syntax' is set to SYNTAX; * `used' is set to the length of the compiled pattern; * `fastmap_accurate' is zero; * `re_nsub' is the number of subexpressions in PATTERN; * `not_bol' and `not_eol' are zero; * * The `fastmap' and `newline_anchor' fields are neither * examined nor set. */ static reg_errcode_t regex_compile(const char *pattern, int size, reg_syntax_t syntax, struct re_pattern_buffer *bufp) { /* We fetch characters from PATTERN here. Even though PATTERN is * `char *' (i.e., signed), we declare these variables as unsigned, so * they can be reliably used as array indices. */ register unsigned char c, c1; /* A random tempory spot in PATTERN. */ const char *p1; /* Points to the end of the buffer, where we should append. */ register unsigned char *b; /* Keeps track of unclosed groups. */ compile_stack_type compile_stack; /* Points to the current (ending) position in the pattern. */ const char *p = pattern; const char *pend = pattern + size; /* How to translate the characters in the pattern. */ char *translate = bufp->translate; /* Address of the count-byte of the most recently inserted `exactn' * command. This makes it possible to tell if a new exact-match * character can be added to that command or if the character requires * a new `exactn' command. */ unsigned char *pending_exact = 0; /* Address of start of the most recently finished expression. * This tells, e.g., postfix * where to find the start of its * operand. Reset at the beginning of groups and alternatives. */ unsigned char *laststart = 0; /* Address of beginning of regexp, or inside of last group. */ unsigned char *begalt; /* Place in the uncompiled pattern (i.e., the {) to * which to go back if the interval is invalid. */ const char *beg_interval; /* Address of the place where a forward jump should go to the end of * the containing expression. Each alternative of an `or' -- except the * last -- ends with a forward jump of this sort. */ unsigned char *fixup_alt_jump = 0; /* Counts open-groups as they are encountered. Remembered for the * matching close-group on the compile stack, so the same register * number is put in the stop_memory as the start_memory. */ regnum_t regnum = 0; #ifdef DEBUG DEBUG_PRINT1("\nCompiling pattern: "); if (debug) { unsigned debug_count; for (debug_count = 0; debug_count < size; debug_count++) printchar(pattern[debug_count]); putchar('\n'); } #endif /* DEBUG */ /* Initialize the compile stack. */ compile_stack.stack = TALLOC(INIT_COMPILE_STACK_SIZE, compile_stack_elt_t); if (compile_stack.stack == NULL) return REG_ESPACE; compile_stack.size = INIT_COMPILE_STACK_SIZE; compile_stack.avail = 0; /* Initialize the pattern buffer. */ bufp->syntax = syntax; bufp->fastmap_accurate = 0; bufp->not_bol = bufp->not_eol = 0; /* Set `used' to zero, so that if we return an error, the pattern * printer (for debugging) will think there's no pattern. We reset it * at the end. */ bufp->used = 0; /* Always count groups, whether or not bufp->no_sub is set. */ bufp->re_nsub = 0; #if !defined (emacs) && !defined (SYNTAX_TABLE) /* Initialize the syntax table. */ init_syntax_once(); #endif if (bufp->allocated == 0) { if (bufp->buffer) { /* If zero allocated, but buffer is non-null, try to realloc * enough space. This loses if buffer's address is bogus, but * that is the user's responsibility. */ RETALLOC(bufp->buffer, INIT_BUF_SIZE, unsigned char); } else { /* Caller did not allocate a buffer. Do it for them. */ bufp->buffer = TALLOC(INIT_BUF_SIZE, unsigned char); } if (!bufp->buffer) return REG_ESPACE; bufp->allocated = INIT_BUF_SIZE; } begalt = b = bufp->buffer; /* Loop through the uncompiled pattern until we're at the end. */ while (p != pend) { PATFETCH(c); switch (c) { case '^': { if ( /* If at start of pattern, it's an operator. */ p == pattern + 1 /* If context independent, it's an operator. */ || syntax & RE_CONTEXT_INDEP_ANCHORS /* Otherwise, depends on what's come before. */ || at_begline_loc_p(pattern, p, syntax)) BUF_PUSH(begline); else goto normal_char; } break; case '$': { if ( /* If at end of pattern, it's an operator. */ p == pend /* If context independent, it's an operator. */ || syntax & RE_CONTEXT_INDEP_ANCHORS /* Otherwise, depends on what's next. */ || at_endline_loc_p(p, pend, syntax)) BUF_PUSH(endline); else goto normal_char; } break; case '+': case '?': if ((syntax & RE_BK_PLUS_QM) || (syntax & RE_LIMITED_OPS)) goto normal_char; handle_plus: case '*': /* If there is no previous pattern... */ if (!laststart) { if (syntax & RE_CONTEXT_INVALID_OPS) return REG_BADRPT; else if (!(syntax & RE_CONTEXT_INDEP_OPS)) goto normal_char; } { /* Are we optimizing this jump? */ boolean keep_string_p = false; /* 1 means zero (many) matches is allowed. */ char zero_times_ok = 0, many_times_ok = 0; /* If there is a sequence of repetition chars, collapse it * down to just one (the right one). We can't combine * interval operators with these because of, e.g., `a{2}*', * which should only match an even number of `a's. */ for (;;) { zero_times_ok |= c != '+'; many_times_ok |= c != '?'; if (p == pend) break; PATFETCH(c); if (c == '*' || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?'))); else if (syntax & RE_BK_PLUS_QM && c == '\\') { if (p == pend) return REG_EESCAPE; PATFETCH(c1); if (!(c1 == '+' || c1 == '?')) { PATUNFETCH; PATUNFETCH; break; } c = c1; } else { PATUNFETCH; break; } /* If we get here, we found another repeat character. */ } /* Star, etc. applied to an empty pattern is equivalent * to an empty pattern. */ if (!laststart) break; /* Now we know whether or not zero matches is allowed * and also whether or not two or more matches is allowed. */ if (many_times_ok) { /* More than one repetition is allowed, so put in at the * end a backward relative jump from `b' to before the next * jump we're going to put in below (which jumps from * laststart to after this jump). * * But if we are at the `*' in the exact sequence `.*\n', * insert an unconditional jump backwards to the ., * instead of the beginning of the loop. This way we only * push a failure point once, instead of every time * through the loop. */ assert(p - 1 > pattern); /* Allocate the space for the jump. */ GET_BUFFER_SPACE(3); /* We know we are not at the first character of the pattern, * because laststart was nonzero. And we've already * incremented `p', by the way, to be the character after * the `*'. Do we have to do something analogous here * for null bytes, because of RE_DOT_NOT_NULL? */ if (TRANSLATE(*(p - 2)) == TRANSLATE('.') && zero_times_ok && p < pend && TRANSLATE(*p) == TRANSLATE('\n') && !(syntax & RE_DOT_NEWLINE)) { /* We have .*\n. */ STORE_JUMP(jump, b, laststart); keep_string_p = true; } else /* Anything else. */ STORE_JUMP(maybe_pop_jump, b, laststart - 3); /* We've added more stuff to the buffer. */ b += 3; } /* 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); b += 3; } } break; case '.': laststart = b; BUF_PUSH(anychar); break; case '[': { boolean had_char_class = false; if (p == pend) return REG_EBRACK; /* Ensure that we have enough space to push a charset: the * opcode, the length count, and the bitset; 34 bytes in all. */ GET_BUFFER_SPACE(34); laststart = b; /* We test `*p == '^' twice, instead of using an if * statement, so we only need one BUF_PUSH. */ BUF_PUSH(*p == '^' ? charset_not : charset); if (*p == '^') p++; /* Remember the first position in the bracket expression. */ p1 = p; /* Push the number of bytes in the bitmap. */ BUF_PUSH((1 << BYTEWIDTH) / BYTEWIDTH); /* Clear the whole map. */ memset(b, 0, (1 << BYTEWIDTH) / BYTEWIDTH); /* charset_not matches newline according to a syntax bit. */ if ((re_opcode_t) b[-2] == charset_not && (syntax & RE_HAT_LISTS_NOT_NEWLINE)) SET_LIST_BIT('\n'); /* Read in characters and ranges, setting map bits. */ for (;;) { if (p == pend) return REG_EBRACK; PATFETCH(c); /* \ might escape characters inside [...] and [^...]. */ if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\') { if (p == pend) return REG_EESCAPE; PATFETCH(c1); SET_LIST_BIT(c1); continue; } /* Could be the end of the bracket expression. If it's * not (i.e., when the bracket expression is `[]' so * far), the ']' character bit gets set way below. */ if (c == ']' && p != p1 + 1) break; /* Look ahead to see if it's a range when the last thing * was a character class. */ if (had_char_class && c == '-' && *p != ']') return REG_ERANGE; /* Look ahead to see if it's a range when the last thing * was a character: if this is a hyphen not at the * beginning or the end of a list, then it's the range * operator. */ if (c == '-' && !(p - 2 >= pattern && p[-2] == '[') && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^') && *p != ']') { reg_errcode_t ret = compile_range(&p, pend, translate, syntax, b); if (ret != REG_NOERROR) return ret; } else if (p[0] == '-' && p[1] != ']') { /* This handles ranges made up of characters only. */ reg_errcode_t ret; /* Move past the `-'. */ PATFETCH(c1); ret = compile_range(&p, pend, translate, syntax, b); if (ret != REG_NOERROR) return ret; } /* See if we're at the beginning of a possible character * class. */ else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':') { /* Leave room for the null. */ char str[CHAR_CLASS_MAX_LENGTH + 1]; PATFETCH(c); c1 = 0; /* If pattern is `[[:'. */ if (p == pend) return REG_EBRACK; for (;;) { PATFETCH(c); if (c == ':' || c == ']' || p == pend || c1 == CHAR_CLASS_MAX_LENGTH) break; str[c1++] = c; } str[c1] = '\0'; /* If isn't a word bracketed by `[:' and:`]': * undo the ending character, the letters, and leave * the leading `:' and `[' (but set bits for them). */ if (c == ':' && *p == ']') { int ch; boolean is_alnum = STREQ(str, "alnum"); boolean is_alpha = STREQ(str, "alpha"); boolean is_blank = STREQ(str, "blank"); boolean is_cntrl = STREQ(str, "cntrl"); boolean is_digit = STREQ(str, "digit"); boolean is_graph = STREQ(str, "graph"); boolean is_lower = STREQ(str, "lower"); boolean is_print = STREQ(str, "print"); boolean is_punct = STREQ(str, "punct"); boolean is_space = STREQ(str, "space"); boolean is_upper = STREQ(str, "upper"); boolean is_xdigit = STREQ(str, "xdigit"); if (!IS_CHAR_CLASS(str)) return REG_ECTYPE; /* Throw away the ] at the end of the character * class. */ PATFETCH(c); if (p == pend) return REG_EBRACK; for (ch = 0; ch < 1 << BYTEWIDTH; ch++) { if ((is_alnum && ISALNUM(ch)) || (is_alpha && ISALPHA(ch)) || (is_blank && ISBLANK(ch)) || (is_cntrl && ISCNTRL(ch)) || (is_digit && ISDIGIT(ch)) || (is_graph && ISGRAPH(ch)) || (is_lower && ISLOWER(ch)) || (is_print && ISPRINT(ch)) || (is_punct && ISPUNCT(ch)) || (is_space && ISSPACE(ch)) || (is_upper && ISUPPER(ch)) || (is_xdigit && ISXDIGIT(ch))) SET_LIST_BIT(ch); } had_char_class = true; } else { c1++; while (c1--) PATUNFETCH; SET_LIST_BIT('['); SET_LIST_BIT(':'); had_char_class = false; } } else { had_char_class = false; SET_LIST_BIT(c); } } /* Discard any (non)matching list bytes that are all 0 at the * end of the map. Decrease the map-length byte too. */ while ((int) b[-1] > 0 && b[b[-1] - 1] == 0) b[-1]--; b += b[-1]; } break; case '(': if (syntax & RE_NO_BK_PARENS) goto handle_open; else goto normal_char; case ')': if (syntax & RE_NO_BK_PARENS) goto handle_close; else goto normal_char; case '\n': if (syntax & RE_NEWLINE_ALT) goto handle_alt; else goto normal_char; case '|': if (syntax & RE_NO_BK_VBAR) goto handle_alt; else goto normal_char; case '{': if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES) goto handle_interval; else goto normal_char; case '\\': if (p == pend) return REG_EESCAPE; /* Do not translate the character after the \, so that we can * distinguish, e.g., \B from \b, even if we normally would * translate, e.g., B to b. */ PATFETCH_RAW(c); switch (c) { case '(': if (syntax & RE_NO_BK_PARENS) goto normal_backslash; handle_open: bufp->re_nsub++; regnum++; if (COMPILE_STACK_FULL) { RETALLOC(compile_stack.stack, compile_stack.size << 1, compile_stack_elt_t); if (compile_stack.stack == NULL) return REG_ESPACE; compile_stack.size <<= 1; } /* These are the values to restore when we hit end of this * group. They are all relative offsets, so that if the * whole pattern moves because of realloc, they will still * be valid. */ COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer; 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 * 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); } compile_stack.avail++; fixup_alt_jump = 0; laststart = 0; begalt = b; /* If we've reached MAX_REGNUM groups, then this open * won't actually generate any code, so we'll have to * 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 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); } /* See similar code for backslashed left paren above. */ if (COMPILE_STACK_EMPTY) { if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD) goto normal_char; else return REG_ERPAREN; } /* Since we just checked for an empty stack above, this * ``can't happen''. */ assert(compile_stack.avail != 0); { /* We don't just want to restore into `regnum', because * later groups should continue to be numbered higher, * as in `(ab)c(de)' -- the second group is #2. */ regnum_t this_group_regnum; compile_stack.avail--; begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset; fixup_alt_jump = COMPILE_STACK_TOP.fixup_alt_jump ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1 : 0; laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset; this_group_regnum = COMPILE_STACK_TOP.regnum; /* If we've reached MAX_REGNUM groups, then this open * won't actually generate any code, so we'll have to * clear pending_exact explicitly. */ pending_exact = 0; /* 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); } } break; case '|': /* `\|'. */ if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR) goto normal_backslash; handle_alt: if (syntax & RE_LIMITED_OPS) goto normal_char; /* Insert before the previous alternative a jump which * jumps to this alternative if the former fails. */ GET_BUFFER_SPACE(3); INSERT_JUMP(on_failure_jump, begalt, b + 6); pending_exact = 0; b += 3; /* The alternative before this one has a jump after it * which gets executed if it gets matched. Adjust that * jump so it will jump to this alternative's analogous * jump (put in below, which in turn will jump to the next * (if any) alternative's such jump, etc.). The last such * jump jumps to the correct final destination. A picture: * _____ _____ * | | | | * | v | v * a | b | c * * If we are at `b', then fixup_alt_jump right now points to a * three-byte space after `a'. We'll put in the jump, set * 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); /* Mark and leave space for a jump after this alternative, * to be filled in later either by next alternative or * when know we're at the end of a series of alternatives. */ fixup_alt_jump = b; GET_BUFFER_SPACE(3); b += 3; laststart = 0; begalt = b; break; case '{': /* If \{ is a literal. */ if (!(syntax & RE_INTERVALS) /* If we're at `\{' and it's not the open-interval * operator. */ || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES)) || (p - 2 == pattern && p == pend)) goto normal_backslash; handle_interval: { /* If got here, then the syntax allows intervals. */ /* At least (most) this many matches must be made. */ int lower_bound = -1, upper_bound = -1; beg_interval = p - 1; if (p == pend) { if (syntax & RE_NO_BK_BRACES) goto unfetch_interval; else return REG_EBRACE; } GET_UNSIGNED_NUMBER(lower_bound); if (c == ',') { GET_UNSIGNED_NUMBER(upper_bound); if (upper_bound < 0) upper_bound = RE_DUP_MAX; } else /* Interval such as `{1}' => match exactly once. */ upper_bound = lower_bound; if (lower_bound < 0 || upper_bound > RE_DUP_MAX || lower_bound > upper_bound) { if (syntax & RE_NO_BK_BRACES) goto unfetch_interval; else return REG_BADBR; } if (!(syntax & RE_NO_BK_BRACES)) { if (c != '\\') return REG_EBRACE; PATFETCH(c); } if (c != '}') { if (syntax & RE_NO_BK_BRACES) goto unfetch_interval; else return REG_BADBR; } /* We just parsed a valid interval. */ /* If it's invalid to have no preceding re. */ if (!laststart) { if (syntax & RE_CONTEXT_INVALID_OPS) return REG_BADRPT; else if (syntax & RE_CONTEXT_INDEP_OPS) laststart = b; else goto unfetch_interval; } /* If the upper bound is zero, don't want to succeed at * all; jump from `laststart' to `b + 3', which will be * the end of the buffer after we insert the jump. */ if (upper_bound == 0) { GET_BUFFER_SPACE(3); INSERT_JUMP(jump, laststart, b + 3); b += 3; } /* Otherwise, we have a nontrivial interval. When * we're all done, the pattern will look like: * set_number_at * set_number_at * succeed_n * * jump_n * (The upper bound and `jump_n' are omitted if * `upper_bound' is 1, though.) */ else { /* If the upper bound is > 1, we need to insert * more at the end of the loop. */ unsigned nbytes = 10 + (upper_bound > 1) * 10; GET_BUFFER_SPACE(nbytes); /* Initialize lower bound of the `succeed_n', even * though it will be set during matching by its * attendant `set_number_at' (inserted next), * because `re_compile_fastmap' needs to know. * Jump to the `jump_n' we might insert below. */ INSERT_JUMP2(succeed_n, laststart, b + 5 + (upper_bound > 1) * 5, lower_bound); b += 5; /* Code to initialize the lower bound. Insert * before the `succeed_n'. The `5' is the last two * bytes of this `set_number_at', plus 3 bytes of * the following `succeed_n'. */ insert_op2(set_number_at, laststart, 5, lower_bound, b); b += 5; if (upper_bound > 1) { /* More than one repetition is allowed, so * append a backward jump to the `succeed_n' * that starts this interval. * * When we've reached this during matching, * we'll have matched the interval once, so * jump back only `upper_bound - 1' times. */ STORE_JUMP2(jump_n, b, laststart + 5, upper_bound - 1); b += 5; /* The location we want to set is the second * parameter of the `jump_n'; that is `b-2' as * an absolute address. `laststart' will be * the `set_number_at' we're about to insert; * `laststart+3' the number to set, the source * for the relative address. But we are * inserting into the middle of the pattern -- * so everything is getting moved up by 5. * Conclusion: (b - 2) - (laststart + 3) + 5, * i.e., b - laststart. * * We insert this at the beginning of the loop * so that if we fail during matching, we'll * reinitialize the bounds. */ insert_op2(set_number_at, laststart, b - laststart, upper_bound - 1, b); b += 5; } } pending_exact = 0; beg_interval = NULL; } break; unfetch_interval: /* If an invalid interval, match the characters as literals. */ assert(beg_interval); p = beg_interval; beg_interval = NULL; /* normal_char and normal_backslash need `c'. */ PATFETCH(c); if (!(syntax & RE_NO_BK_BRACES)) { if (p > pattern && p[-1] == '\\') goto normal_backslash; } goto normal_char; #ifdef emacs /* There is no way to specify the before_dot and after_dot * operators. rms says this is ok. --karl */ case '=': BUF_PUSH(at_dot); break; case 's': laststart = b; PATFETCH(c); BUF_PUSH_2(syntaxspec, syntax_spec_code[c]); break; case 'S': laststart = b; PATFETCH(c); BUF_PUSH_2(notsyntaxspec, syntax_spec_code[c]); break; #endif /* emacs */ case 'w': laststart = b; BUF_PUSH(wordchar); break; case 'W': laststart = b; BUF_PUSH(notwordchar); break; case '<': BUF_PUSH(wordbeg); break; case '>': BUF_PUSH(wordend); break; case 'b': BUF_PUSH(wordbound); break; case 'B': BUF_PUSH(notwordbound); break; case '`': BUF_PUSH(begbuf); break; case '\'': BUF_PUSH(endbuf); break; case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': if (syntax & RE_NO_BK_REFS) goto normal_char; c1 = c - '0'; if (c1 > regnum) return REG_ESUBREG; /* Can't back reference to a subexpression if inside of it. */ if (group_in_compile_stack(compile_stack, c1)) goto normal_char; laststart = b; BUF_PUSH_2(duplicate, c1); break; case '+': case '?': if (syntax & RE_BK_PLUS_QM) goto handle_plus; else goto normal_backslash; default: normal_backslash: /* You might think it would be useful for \ to mean * not to translate; but if we don't translate it * it will never match anything. */ c = TRANSLATE(c); goto normal_char; } break; default: /* Expects the character in `c'. */ normal_char: /* If no exactn currently being built. */ if (!pending_exact /* If last exactn not at current position. */ || pending_exact + *pending_exact + 1 != b /* We have only one byte following the exactn for the count. */ || *pending_exact == (1 << BYTEWIDTH) - 1 /* If followed by a repetition operator. */ || *p == '*' || *p == '^' || ((syntax & RE_BK_PLUS_QM) ? *p == '\\' && (p[1] == '+' || p[1] == '?') : (*p == '+' || *p == '?')) || ((syntax & RE_INTERVALS) && ((syntax & RE_NO_BK_BRACES) ? *p == '{' : (p[0] == '\\' && p[1] == '{')))) { /* Start building a new exactn. */ laststart = b; BUF_PUSH_2(exactn, 0); pending_exact = b - 1; } BUF_PUSH(c); (*pending_exact)++; break; } /* switch (c) */ } /* while p != pend */ /* Through the pattern now. */ if (fixup_alt_jump) STORE_JUMP(jump_past_alt, fixup_alt_jump, b); if (!COMPILE_STACK_EMPTY) return REG_EPAREN; free(compile_stack.stack); /* We have succeeded; set the length of the buffer. */ bufp->used = b - bufp->buffer; #ifdef DEBUG if (debug) { DEBUG_PRINT1("\nCompiled pattern: "); print_compiled_pattern(bufp); } #endif /* DEBUG */ return REG_NOERROR; } /* regex_compile */ /* Subroutines for `regex_compile'. */ /* Store OP at LOC followed by two-byte integer parameter ARG. */ void store_op1(re_opcode_t op, unsigned char *loc, int arg) { *loc = (unsigned char) op; STORE_NUMBER(loc + 1, arg); } /* Like `store_op1', but for two two-byte parameters ARG1 and ARG2. */ void store_op2( re_opcode_t op, unsigned char *loc, int arg1, int arg2) { *loc = (unsigned char) op; STORE_NUMBER(loc + 1, arg1); STORE_NUMBER(loc + 3, arg2); } /* Copy the bytes from LOC to END to open up three bytes of space at LOC * for OP followed by two-byte integer parameter ARG. */ void insert_op1(re_opcode_t op, unsigned char *loc, int arg, unsigned char *end) { register unsigned char *pfrom = end; register unsigned char *pto = end + 3; while (pfrom != loc) *--pto = *--pfrom; store_op1(op, loc, arg); } /* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2. */ void insert_op2(re_opcode_t op, unsigned char *loc, int arg1, int arg2, unsigned char *end) { register unsigned char *pfrom = end; register unsigned char *pto = end + 5; while (pfrom != loc) *--pto = *--pfrom; store_op2(op, loc, arg1, arg2); } /* P points to just after a ^ in PATTERN. Return true if that ^ comes * after an alternative or a begin-subexpression. We assume there is at * least one character before the ^. */ boolean at_begline_loc_p(const char * pattern, const char *p, reg_syntax_t syntax) { const char *prev = p - 2; boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\'; return /* After a subexpression? */ (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash)) /* After an alternative? */ || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash)); } /* The dual of at_begline_loc_p. This one is for $. We assume there is * at least one character after the $, i.e., `P < PEND'. */ boolean at_endline_loc_p(const char *p, const char *pend, int syntax) { const char *next = p; boolean next_backslash = *next == '\\'; const char *next_next = p + 1 < pend ? p + 1 : NULL; return /* Before a subexpression? */ (syntax & RE_NO_BK_PARENS ? *next == ')' : next_backslash && next_next && *next_next == ')') /* Before an alternative? */ || (syntax & RE_NO_BK_VBAR ? *next == '|' : next_backslash && next_next && *next_next == '|'); } /* Returns true if REGNUM is in one of COMPILE_STACK's elements and * false if it's not. */ boolean group_in_compile_stack(compile_stack_type compile_stack, regnum_t regnum) { int this_element; for (this_element = compile_stack.avail - 1; this_element >= 0; this_element--) if (compile_stack.stack[this_element].regnum == regnum) return true; return false; } /* Read the ending character of a range (in a bracket expression) from the * uncompiled pattern *P_PTR (which ends at PEND). We assume the * starting character is in `P[-2]'. (`P[-1]' is the character `-'.) * Then we set the translation of all bits between the starting and * ending characters (inclusive) in the compiled pattern B. * * Return an error code. * * We use these short variable names so we can use the same macros as * `regex_compile' itself. */ reg_errcode_t compile_range(const char **p_ptr, const char *pend, char *translate, reg_syntax_t syntax, unsigned char *b) { unsigned this_char; const char *p = *p_ptr; int range_start, range_end; if (p == pend) return REG_ERANGE; /* Even though the pattern is a signed `char *', we need to fetch * with unsigned char *'s; if the high bit of the pattern character * is set, the range endpoints will be negative if we fetch using a * signed char *. * * We also want to fetch the endpoints without translating them; the * appropriate translation is done in the bit-setting loop below. */ range_start = ((unsigned char *) p)[-2]; range_end = ((unsigned char *) p)[0]; /* Have to increment the pointer into the pattern string, so the * caller isn't still at the ending character. */ (*p_ptr)++; /* If the start is after the end, the range is empty. */ if (range_start > range_end) return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR; /* Here we see why `this_char' has to be larger than an `unsigned * char' -- the range is inclusive, so if `range_end' == 0xff * (assuming 8-bit characters), we would otherwise go into an infinite * loop, since all characters <= 0xff. */ for (this_char = range_start; this_char <= range_end; this_char++) { SET_LIST_BIT(TRANSLATE(this_char)); } return REG_NOERROR; } /* Failure stack declarations and macros; both re_compile_fastmap and * re_match_2 use a failure stack. These have to be macros because of * REGEX_ALLOCATE. */ /* Number of failure points for which to initially allocate space * when matching. If this number is exceeded, we allocate more * space, so it is not a hard limit. */ #ifndef INIT_FAILURE_ALLOC #define INIT_FAILURE_ALLOC 5 #endif /* Roughly the maximum number of failure points on the stack. Would be * exactly that if always used MAX_FAILURE_SPACE each time we failed. * This is a variable only so users of regex can assign to it; we never * change it ourselves. */ int re_max_failures = 2000; typedef const unsigned char *fail_stack_elt_t; typedef struct { fail_stack_elt_t *stack; unsigned size; unsigned avail; /* Offset of next open position. */ } fail_stack_type; #define FAIL_STACK_EMPTY() (fail_stack.avail == 0) #define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0) #define FAIL_STACK_FULL() (fail_stack.avail == fail_stack.size) #define FAIL_STACK_TOP() (fail_stack.stack[fail_stack.avail]) /* Initialize `fail_stack'. Do `return -2' if the alloc fails. */ #define INIT_FAIL_STACK() \ do { \ fail_stack.stack = (fail_stack_elt_t *) \ REGEX_ALLOCATE (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \ \ if (fail_stack.stack == NULL) \ return -2; \ \ fail_stack.size = INIT_FAILURE_ALLOC; \ fail_stack.avail = 0; \ } while (0) /* Double the size of FAIL_STACK, up to approximately `re_max_failures' items. * * Return 1 if succeeds, and 0 if either ran out of memory * allocating space for it or it was already too large. * * REGEX_REALLOCATE requires `destination' be declared. */ #define DOUBLE_FAIL_STACK(fail_stack) \ ((fail_stack).size > re_max_failures * MAX_FAILURE_ITEMS \ ? 0 \ : ((fail_stack).stack = (fail_stack_elt_t *) \ REGEX_REALLOCATE ((fail_stack).stack, \ (fail_stack).size * sizeof (fail_stack_elt_t), \ ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)), \ \ (fail_stack).stack == NULL \ ? 0 \ : ((fail_stack).size <<= 1, \ 1))) /* Push PATTERN_OP on FAIL_STACK. * * Return 1 if was able to do so and 0 if ran out of memory allocating * space to do so. */ #define PUSH_PATTERN_OP(pattern_op, fail_stack) \ ((FAIL_STACK_FULL () \ && !DOUBLE_FAIL_STACK (fail_stack)) \ ? 0 \ : ((fail_stack).stack[(fail_stack).avail++] = pattern_op, \ 1)) /* This pushes an item onto the failure stack. Must be a four-byte * value. Assumes the variable `fail_stack'. Probably should only * be called from within `PUSH_FAILURE_POINT'. */ #define PUSH_FAILURE_ITEM(item) \ fail_stack.stack[fail_stack.avail++] = (fail_stack_elt_t) item /* The complement operation. Assumes `fail_stack' is nonempty. */ #define POP_FAILURE_ITEM() 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_ITEM #define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_ITEM () #else #define DEBUG_PUSH(item) #define DEBUG_POP(item_addr) #endif /* 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 * num_regs be declared. DOUBLE_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 (!DOUBLE_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"); \ \ 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_ITEM (regstart[this_reg]); \ \ DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \ PUSH_FAILURE_ITEM (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_ITEM (reg_info[this_reg].word); \ } \ \ DEBUG_PRINT2 (" Pushing low active reg: %d\n", lowest_active_reg);\ PUSH_FAILURE_ITEM (lowest_active_reg); \ \ DEBUG_PRINT2 (" Pushing high active reg: %d\n", highest_active_reg);\ PUSH_FAILURE_ITEM (highest_active_reg); \ \ DEBUG_PRINT2 (" Pushing pattern 0x%x: ", pattern_place); \ DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend); \ PUSH_FAILURE_ITEM (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_ITEM (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 /* We push at most this many items on the stack. */ #define MAX_FAILURE_ITEMS ((num_regs - 1) * NUM_REG_ITEMS + NUM_NONREG_ITEMS) /* We actually push this many items. */ #define NUM_FAILURE_ITEMS \ ((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) /* Pops what PUSH_FAIL_STACK pushes. * * 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; \ \ assert (!FAIL_STACK_EMPTY ()); \ \ /* Remove failure points and point to how many regs pushed. */ \ DEBUG_PRINT1 ("POP_FAILURE_POINT:\n"); \ 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); \ \ DEBUG_POP (&failure_id); \ DEBUG_PRINT2 (" Popping failure id: %u\n", failure_id); \ \ /* 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_ITEM (); \ if (string_temp != NULL) \ str = (const char *) string_temp; \ \ DEBUG_PRINT2 (" Popping string 0x%x: `", str); \ DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2); \ DEBUG_PRINT1 ("'\n"); \ \ pat = (unsigned char *) POP_FAILURE_ITEM (); \ DEBUG_PRINT2 (" Popping pattern 0x%x: ", pat); \ DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend); \ \ /* Restore register info. */ \ high_reg = (unsigned long) POP_FAILURE_ITEM (); \ DEBUG_PRINT2 (" Popping high active reg: %d\n", high_reg); \ \ low_reg = (unsigned long) POP_FAILURE_ITEM (); \ DEBUG_PRINT2 (" Popping low active reg: %d\n", low_reg); \ \ 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_ITEM (); \ DEBUG_PRINT2 (" info: 0x%x\n", reg_info[this_reg]); \ \ regend[this_reg] = (const char *) POP_FAILURE_ITEM (); \ DEBUG_PRINT2 (" end: 0x%x\n", regend[this_reg]); \ \ regstart[this_reg] = (const char *) POP_FAILURE_ITEM (); \ DEBUG_PRINT2 (" start: 0x%x\n", regstart[this_reg]); \ } \ \ DEBUG_STATEMENT (nfailure_points_popped++); \ } /* POP_FAILURE_POINT */ /* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in * BUFP. A fastmap records which of the (1 << BYTEWIDTH) possible * characters can start a string that matches the pattern. This fastmap * is used by re_search to skip quickly over impossible starting points. * * The caller must supply the address of a (1 << BYTEWIDTH)-byte data * area as BUFP->fastmap. * * We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in * the pattern buffer. * * Returns 0 if we succeed, -2 if an internal error. */ int re_compile_fastmap(bufp) struct re_pattern_buffer *bufp; { int j, k; fail_stack_type fail_stack; #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; unsigned long size = bufp->used; const unsigned char *p = pattern; register unsigned char *pend = pattern + size; /* Assume that each path through the pattern can be null until * proven otherwise. We set this false at the bottom of switch * statement, to which we get only if a particular path doesn't * match the empty string. */ boolean path_can_be_null = true; /* We aren't doing a `succeed_n' to begin with. */ boolean succeed_n_p = false; assert(fastmap != NULL && p != NULL); INIT_FAIL_STACK(); memset(fastmap, 0, 1 << BYTEWIDTH); /* Assume nothing's valid. */ bufp->fastmap_accurate = 1; /* It will be when we're done. */ bufp->can_be_null = 0; while (p != pend || !FAIL_STACK_EMPTY()) { if (p == pend) { bufp->can_be_null |= path_can_be_null; /* Reset for next path. */ path_can_be_null = true; p = fail_stack.stack[--fail_stack.avail]; } /* We should never be about to go beyond the end of the pattern. */ assert(p < pend); #ifdef SWITCH_ENUM_BUG switch ((int) ((re_opcode_t) * p++)) #else switch ((re_opcode_t) * p++) #endif { /* 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; return 0; /* Following are the cases which match a character. These end * with `break'. */ case exactn: fastmap[p[1]] = 1; break; case charset: for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))) fastmap[j] = 1; break; case charset_not: /* Chars beyond end of map must be allowed. */ for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++) fastmap[j] = 1; for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))) fastmap[j] = 1; break; case wordchar: for (j = 0; j < (1 << BYTEWIDTH); j++) if (SYNTAX(j) == Sword) fastmap[j] = 1; break; case notwordchar: for (j = 0; j < (1 << BYTEWIDTH); j++) if (SYNTAX(j) != Sword) fastmap[j] = 1; break; case anychar: /* `.' matches anything ... */ for (j = 0; j < (1 << BYTEWIDTH); j++) fastmap[j] = 1; /* ... except perhaps newline. */ if (!(bufp->syntax & RE_DOT_NEWLINE)) fastmap['\n'] = 0; /* 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) return 0; /* Otherwise, have to check alternative paths. */ break; #ifdef emacs case syntaxspec: k = *p++; for (j = 0; j < (1 << BYTEWIDTH); j++) if (SYNTAX(j) == (enum syntaxcode) k) fastmap[j] = 1; break; case notsyntaxspec: k = *p++; for (j = 0; j < (1 << BYTEWIDTH); j++) if (SYNTAX(j) != (enum syntaxcode) k) fastmap[j] = 1; break; /* All cases after this match the empty string. These end with * `continue'. */ case before_dot: case at_dot: case after_dot: continue; #endif /* not emacs */ case no_op: case begline: case endline: case begbuf: case endbuf: case wordbound: case notwordbound: case wordbeg: case wordend: 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); 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] == p) fail_stack.avail--; continue; case on_failure_jump: case on_failure_keep_string_jump: handle_on_failure_jump: EXTRACT_NUMBER_AND_INCR(j, p); /* For some patterns, e.g., `(a?)?', `p+j' here points to the * end of the pattern. We don't want to push such a point, * since when we restore it above, entering the switch will * increment `p' past the end of the pattern. We don't need * 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 (!PUSH_PATTERN_OP(p + j, fail_stack)) return -2; } else bufp->can_be_null = 1; if (succeed_n_p) { EXTRACT_NUMBER_AND_INCR(k, p); /* Skip the n. */ succeed_n_p = false; } continue; case succeed_n: /* Get to the number of times to succeed. */ p += 2; /* Increment p past the n for when k != 0. */ EXTRACT_NUMBER_AND_INCR(k, p); if (k == 0) { p -= 4; succeed_n_p = true; /* Spaghetti code alert. */ goto handle_on_failure_jump; } continue; case set_number_at: p += 4; continue; case start_memory: case stop_memory: p += 2; continue; default: abort(); /* We have listed all the cases. */ } /* switch *p++ */ /* Getting here means we have found the possible starting * characters for one path of the pattern -- and that the empty * string does not match. We need not follow this path further. * Instead, look at the next alternative (remembered on the * stack), or quit if no more. The test at the top of the loop * does these things. */ path_can_be_null = false; p = pend; } /* while p */ /* 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; return 0; } /* re_compile_fastmap */ /* Set REGS to hold NUM_REGS registers, storing them in STARTS and * ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use * this memory for recording register information. STARTS and ENDS * must be allocated using the malloc library routine, and must each * be at least NUM_REGS * sizeof (regoff_t) bytes long. * * If NUM_REGS == 0, then subsequent matches should allocate their own * register data. * * Unless this function is called, the first search or match using * PATTERN_BUFFER will allocate its own register data, without * freeing the old data. */ void re_set_registers(bufp, regs, num_regs, starts, ends) struct re_pattern_buffer *bufp; struct re_registers *regs; unsigned num_regs; regoff_t *starts, *ends; { if (num_regs) { bufp->regs_allocated = REGS_REALLOCATE; regs->num_regs = num_regs; regs->start = starts; regs->end = ends; } else { bufp->regs_allocated = REGS_UNALLOCATED; regs->num_regs = 0; regs->start = regs->end = (regoff_t) 0; } } /* Searching routines. */ /* Like re_search_2, below, but only one string is specified, and * doesn't let you say where to stop matching. */ int re_search(bufp, string, size, startpos, range, regs) struct re_pattern_buffer *bufp; const char *string; int size, startpos, range; struct re_registers *regs; { return re_search_2(bufp, NULL, 0, string, size, startpos, range, regs, size); } /* Using the compiled pattern in BUFP->buffer, first tries to match the * virtual concatenation of STRING1 and STRING2, starting first at index * STARTPOS, then at STARTPOS + 1, and so on. * * STRING1 and STRING2 have length SIZE1 and SIZE2, respectively. * * RANGE is how far to scan while trying to match. RANGE = 0 means try * only at STARTPOS; in general, the last start tried is STARTPOS + * RANGE. * * In REGS, return the indices of the virtual concatenation of STRING1 * and STRING2 that matched the entire BUFP->buffer and its contained * subexpressions. * * Do not consider matching one past the index STOP in the virtual * concatenation of STRING1 and STRING2. * * We return either the position in the strings at which the match was * found, -1 if no match, or -2 if error (such as failure * stack overflow). */ int re_search_2(bufp, string1, size1, string2, size2, startpos, range, regs, stop) struct re_pattern_buffer *bufp; const char *string1, *string2; int size1, size2; int startpos; int range; struct re_registers *regs; int stop; { int val; register char *fastmap = bufp->fastmap; register char *translate = bufp->translate; int total_size = size1 + size2; int endpos = startpos + range; /* Check for out-of-range STARTPOS. */ if (startpos < 0 || startpos > total_size) return -1; /* Fix up RANGE if it might eventually take us outside * the virtual concatenation of STRING1 and STRING2. */ if (endpos < -1) range = -1 - startpos; else if (endpos > total_size) range = total_size - startpos; /* If the search isn't to be a backwards one, don't waste time in a * search for a pattern that must be anchored. */ if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0) { if (startpos > 0) return -1; else range = 1; } /* Update the fastmap now if not correct already. */ if (fastmap && !bufp->fastmap_accurate) if (re_compile_fastmap(bufp) == -2) return -2; /* Loop through the string, looking for a place to start matching. */ for (;;) { /* If a fastmap is supplied, skip quickly over characters that * cannot be the start of a match. If the pattern can match the * null string, however, we don't need to skip characters; we want * the first null string. */ if (fastmap && startpos < total_size && !bufp->can_be_null) { if (range > 0) { /* Searching forwards. */ register const char *d; register int lim = 0; int irange = range; if (startpos < size1 && startpos + range >= size1) lim = range - (size1 - startpos); d = (startpos >= size1 ? string2 - size1 : string1) + startpos; /* Written out as an if-else to avoid testing `translate' * inside the loop. */ if (translate) while (range > lim && !fastmap[(unsigned char) translate[(unsigned char) *d++]]) range--; else while (range > lim && !fastmap[(unsigned char) *d++]) range--; startpos += irange - range; } else { /* Searching backwards. */ register char c = (size1 == 0 || startpos >= size1 ? string2[startpos - size1] : string1[startpos]); if (!fastmap[(unsigned char) TRANSLATE(c)]) goto advance; } } /* If can't match the null string, and that's all we have left, fail. */ if (range >= 0 && startpos == total_size && fastmap && !bufp->can_be_null) return -1; val = re_match_2(bufp, string1, size1, string2, size2, startpos, regs, stop); if (val >= 0) return startpos; if (val == -2) return -2; advance: if (!range) break; else if (range > 0) { range--; startpos++; } else { range++; startpos--; } } return -1; } /* re_search_2 */ /* Declarations and macros for re_match_2. */ /* Structure for per-register (a.k.a. per-group) information. * This must not be longer than one word, because we push this value * onto the failure stack. 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; static boolean alt_match_null_string_p(unsigned char *p, unsigned char *end, register_info_type *reg_info); static boolean common_op_match_null_string_p( unsigned char **p, unsigned char *end, register_info_type *reg_info); static int bcmp_translate(unsigned char const *s1, unsigned char const *s2, register int len, char *translate); static boolean group_match_null_string_p(unsigned char **p, unsigned char *end, register_info_type *reg_info); #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 \ { \ unsigned r; \ for (r = lowest_active_reg; r <= highest_active_reg; r++) \ { \ MATCHED_SOMETHING (reg_info[r]) \ = EVER_MATCHED_SOMETHING (reg_info[r]) \ = 1; \ } \ } \ while (0) /* This converts PTR, a pointer into one of the search strings `string1' * and `string2' into an offset from the beginning of that string. */ #define POINTER_TO_OFFSET(ptr) \ (FIRST_STRING_P (ptr) ? (ptr) - string1 : (ptr) - string2 + size1) /* Registers are set to a sentinel when they haven't yet matched. */ #define REG_UNSET_VALUE ((char *) -1) #define REG_UNSET(e) ((e) == REG_UNSET_VALUE) /* Macros for dealing with the split strings in re_match_2. */ #define MATCHING_IN_FIRST_STRING (dend == end_match_1) /* Call before fetching a character with *d. This switches over to * string2 if necessary. */ #define PREFETCH() \ while (d == dend) \ { \ /* End of string2 => fail. */ \ if (dend == end_match_2) \ goto fail; \ /* End of string1 => advance to string2. */ \ d = string2; \ dend = end_match_2; \ } /* Test if at very beginning or at very end of the virtual concatenation * of `string1' and `string2'. If only one string, it's `string2'. */ #define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2) #define AT_STRINGS_END(d) ((d) == end2) /* Test if D points to a character which is word-constituent. We have * two special cases to check for: if past the end of string1, look at * the first character in string2; and if before the beginning of * string2, look at the last character in string1. */ #define WORDCHAR_P(d) \ (SYNTAX ((d) == end1 ? *string2 \ : (d) == string2 - 1 ? *(end1 - 1) : *(d)) \ == Sword) /* Test if the character before D and the one at D differ with respect * to being word-constituent. */ #define AT_WORD_BOUNDARY(d) \ (AT_STRINGS_BEG (d) || AT_STRINGS_END (d) \ || WORDCHAR_P (d - 1) != WORDCHAR_P (d)) /* Free everything we malloc. */ #ifdef REGEX_MALLOC #define FREE_VAR(var) if (var) free (var); var = NULL #define FREE_VARIABLES() \ do { \ FREE_VAR (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 /* not REGEX_MALLOC */ /* Some MIPS systems (at least) want this to free alloca'd storage. */ #define FREE_VARIABLES() alloca (0) #endif /* not REGEX_MALLOC */ /* 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) /* Matching routines. */ #ifndef emacs /* Emacs never uses this. */ /* re_match is like re_match_2 except it takes only a single string. */ int re_match(bufp, string, size, pos, regs) struct re_pattern_buffer *bufp; const char *string; int size, pos; struct re_registers *regs; { return re_match_2(bufp, NULL, 0, string, size, pos, regs, size); } #endif /* not emacs */ /* re_match_2 matches the compiled pattern in BUFP against the * the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1 * and SIZE2, respectively). We start matching at POS, and stop * matching at STOP. * * If REGS is non-null and the `no_sub' field of BUFP is nonzero, we * store offsets for the substring each group matched in REGS. See the * documentation for exactly how many groups we fill. * * We return -1 if no match, -2 if an internal error (such as the * failure stack overflowing). Otherwise, we return the length of the * matched substring. */ int re_match_2(bufp, string1, size1, string2, size2, pos, regs, stop) struct re_pattern_buffer *bufp; const char *string1, *string2; int size1, size2; int pos; struct re_registers *regs; int stop; { /* General temporaries. */ int mcnt; unsigned char *p1; /* Just past the end of the corresponding string. */ const char *end1, *end2; /* Pointers into string1 and string2, just past the last characters in * each to consider matching. */ const char *end_match_1, *end_match_2; /* Where we are in the data, and the end of the current string. */ const char *d, *dend; /* Where we are in the pattern, and the end of the pattern. */ unsigned char *p = bufp->buffer; register unsigned char *pend = p + bufp->used; /* We use this to map every character in the string. */ char *translate = bufp->translate; /* 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 * 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. */ fail_stack_type fail_stack; #ifdef DEBUG static unsigned failure_id = 0; unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0; #endif /* We fill all the registers internally, independent of what we * return, for use in backreferences. The number here includes * an element for register zero. */ unsigned num_regs = bufp->re_nsub + 1; /* The currently active registers. */ unsigned long lowest_active_reg = NO_LOWEST_ACTIVE_REG; unsigned long 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 * regnum-th regstart pointer points to where in the pattern we began * matching and the regnum-th regend points to right after where we * stopped matching the regnum-th subexpression. (The zeroth register * keeps track of what the whole pattern matches.) */ const char **regstart = NULL, **regend = NULL; /* 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. */ const char **old_regstart = NULL, **old_regend = NULL; /* 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. */ register_info_type *reg_info = NULL; /* 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 * turn happens only if we have not yet matched the entire string. */ unsigned best_regs_set = false; const char **best_regstart = NULL, **best_regend = NULL; /* Logically, this is `best_regend[0]'. But we don't want to have to * allocate space for that if we're not allocating space for anything * else (see below). Also, we never need info about register 0 for * any of the other register vectors, and it seems rather a kludge to * treat `best_regend' differently than the rest. So we keep track of * the end of the best match so far in a separate variable. We * initialize this to NULL so that when we backtrack the first time * and need to test it, it's not garbage. */ const char *match_end = NULL; /* Used when we pop values we don't care about. */ const char **reg_dummy = NULL; register_info_type *reg_info_dummy = NULL; #ifdef DEBUG /* Counts the total number of registers pushed. */ unsigned num_regs_pushed = 0; #endif DEBUG_PRINT1("\n\nEntering re_match_2.\n"); INIT_FAIL_STACK(); /* Do not bother to initialize all the register variables if there are * no groups in the pattern, as it takes a fair amount of time. If * there are groups, we include space for register 0 (the whole * pattern), even though we never use it, since it simplifies the * array indexing. We should fix this. */ if (bufp->re_nsub) { 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)) { FREE_VARIABLES(); return -2; } } #ifdef REGEX_MALLOC else { /* 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; } #endif /* REGEX_MALLOC */ /* The starting position is bogus. */ if (pos < 0 || pos > size1 + size2) { FREE_VARIABLES(); return -1; } /* Initialize subexpression text positions to -1 to mark ones that no * start_memory/stop_memory has been seen for. Also initialize the * 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; } /* We move `string1' into `string2' if the latter's empty -- but not if * `string1' is null. */ if (size2 == 0 && string1 != NULL) { string2 = string1; size2 = size1; string1 = 0; size1 = 0; } end1 = string1 + size1; end2 = string2 + size2; /* Compute where to stop matching, within the two strings. */ if (stop <= size1) { end_match_1 = string1 + stop; end_match_2 = string2; } else { end_match_1 = end1; end_match_2 = string2 + stop - size1; } /* `p' scans through the pattern as `d' scans through the data. * `dend' is the end of the input string that `d' points within. `d' * is advanced into the following input string whenever necessary, but * this happens before fetching; therefore, at the beginning of the * loop, `d' can be pointing at the end of a string, but it cannot * equal `string2'. */ if (size1 > 0 && pos <= size1) { d = string1 + pos; dend = end_match_1; } else { d = string2 + pos - size1; dend = end_match_2; } DEBUG_PRINT1("The compiled pattern is: "); DEBUG_PRINT_COMPILED_PATTERN(bufp, p, pend); DEBUG_PRINT1("The string to match is: `"); DEBUG_PRINT_DOUBLE_STRING(d, string1, size1, string2, size2); DEBUG_PRINT1("'\n"); /* This loops over pattern commands. It exits by returning from the * function if the match is complete, or it drops through if the match * fails at this starting point in the input data. */ for (;;) { DEBUG_PRINT2("\n0x%x: ", p); if (p == pend) { /* End of pattern means we might have succeeded. */ DEBUG_PRINT1("end of pattern ... "); /* If we haven't matched the entire string, and we want the * longest match, try backtracking. */ if (d != end_match_2) { DEBUG_PRINT1("backtracking.\n"); if (!FAIL_STACK_EMPTY()) { /* More failure points to try. */ boolean same_str_p = (FIRST_STRING_P(match_end) == MATCHING_IN_FIRST_STRING); /* If exceeds best match so far, save it. */ if (!best_regs_set || (same_str_p && d > match_end) || (!same_str_p && !MATCHING_IN_FIRST_STRING)) { best_regs_set = true; match_end = d; DEBUG_PRINT1("\nSAVING match as best so far.\n"); for (mcnt = 1; mcnt < num_regs; mcnt++) { best_regstart[mcnt] = regstart[mcnt]; best_regend[mcnt] = regend[mcnt]; } } goto fail; } /* If no failure points, don't restore garbage. */ else if (best_regs_set) { restore_best_regs: /* Restore best match. It may happen that `dend == * end_match_1' while the restored d is in string2. * For example, the pattern `x.*y.*z' against the * strings `x-' and `y-z-', if the two strings are * not consecutive in memory. */ DEBUG_PRINT1("Restoring best registers.\n"); d = match_end; dend = ((d >= string1 && d <= end1) ? end_match_1 : end_match_2); for (mcnt = 1; mcnt < num_regs; mcnt++) { regstart[mcnt] = best_regstart[mcnt]; regend[mcnt] = best_regend[mcnt]; } } } /* d != end_match_2 */ DEBUG_PRINT1("Accepting match.\n"); /* If caller wants register contents data back, do it. */ if (regs && !bufp->no_sub) { /* Have the register data arrays been allocated? */ if (bufp->regs_allocated == REGS_UNALLOCATED) { /* No. So allocate them with malloc. We need one * extra element beyond `num_regs' for the `-1' marker * GNU code uses. */ regs->num_regs = MAX(RE_NREGS, num_regs + 1); regs->start = TALLOC(regs->num_regs, regoff_t); regs->end = TALLOC(regs->num_regs, regoff_t); if (regs->start == NULL || regs->end == NULL) return -2; bufp->regs_allocated = REGS_REALLOCATE; } else if (bufp->regs_allocated == REGS_REALLOCATE) { /* Yes. If we need more elements than were already * allocated, reallocate them. If we need fewer, just * leave it alone. */ if (regs->num_regs < num_regs + 1) { regs->num_regs = num_regs + 1; RETALLOC(regs->start, regs->num_regs, regoff_t); RETALLOC(regs->end, regs->num_regs, regoff_t); if (regs->start == NULL || regs->end == NULL) return -2; } } else assert(bufp->regs_allocated == REGS_FIXED); /* Convert the pointer data in `regstart' and `regend' to * indices. Register zero has to be set differently, * since we haven't kept track of any info for it. */ if (regs->num_regs > 0) { regs->start[0] = pos; regs->end[0] = (MATCHING_IN_FIRST_STRING ? d - string1 : d - string2 + size1); } /* Go through the first `min (num_regs, regs->num_regs)' * registers, since that is all we initialized. */ for (mcnt = 1; mcnt < MIN(num_regs, regs->num_regs); mcnt++) { if (REG_UNSET(regstart[mcnt]) || REG_UNSET(regend[mcnt])) regs->start[mcnt] = regs->end[mcnt] = -1; else { regs->start[mcnt] = POINTER_TO_OFFSET(regstart[mcnt]); regs->end[mcnt] = POINTER_TO_OFFSET(regend[mcnt]); } } /* If the regs structure we return has more elements than * were in the pattern, set the extra elements to -1. If * we (re)allocated the registers, this is the case, * because we always allocate enough to have at least one * -1 at the end. */ for (mcnt = num_regs; mcnt < regs->num_regs; mcnt++) regs->start[mcnt] = regs->end[mcnt] = -1; } /* regs && !bufp->no_sub */ FREE_VARIABLES(); DEBUG_PRINT4("%u failure points pushed, %u popped (%u remain).\n", nfailure_points_pushed, nfailure_points_popped, nfailure_points_pushed - nfailure_points_popped); DEBUG_PRINT2("%u registers pushed.\n", num_regs_pushed); mcnt = d - pos - (MATCHING_IN_FIRST_STRING ? string1 : string2 - size1); DEBUG_PRINT2("Returning %d from re_match_2.\n", mcnt); return mcnt; } /* Otherwise match next pattern command. */ #ifdef SWITCH_ENUM_BUG switch ((int) ((re_opcode_t) * p++)) #else switch ((re_opcode_t) * p++) #endif { /* Ignore these. Used to ignore the n of succeed_n's which * currently have n == 0. */ case no_op: DEBUG_PRINT1("EXECUTING no_op.\n"); break; /* Match the next n pattern characters exactly. The following * byte in the pattern defines n, and the n bytes after that * are the characters to match. */ case exactn: mcnt = *p++; DEBUG_PRINT2("EXECUTING exactn %d.\n", mcnt); /* This is written out as an if-else so we don't waste time * testing `translate' inside the loop. */ if (translate) { do { PREFETCH(); if (translate[(unsigned char) *d++] != (char) *p++) goto fail; } while (--mcnt); } else { do { PREFETCH(); if (*d++ != (char) *p++) goto fail; } while (--mcnt); } SET_REGS_MATCHED(); break; /* Match any character except possibly a newline or a null. */ case anychar: DEBUG_PRINT1("EXECUTING anychar.\n"); PREFETCH(); if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE(*d) == '\n') || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE(*d) == '\000')) goto fail; SET_REGS_MATCHED(); DEBUG_PRINT2(" Matched `%d'.\n", *d); d++; break; case charset: case charset_not: { register unsigned char c; boolean not = (re_opcode_t) * (p - 1) == charset_not; DEBUG_PRINT2("EXECUTING charset%s.\n", not ? "_not" : ""); PREFETCH(); c = TRANSLATE(*d); /* The character to match. */ /* Cast to `unsigned' instead of `unsigned char' in case the * bit list is a full 32 bytes long. */ if (c < (unsigned) (*p * BYTEWIDTH) && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) not = !not; p += 1 + *p; if (!not) goto fail; SET_REGS_MATCHED(); d++; 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 * 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])); regstart[*p] = d; DEBUG_PRINT2(" regstart: %d\n", POINTER_TO_OFFSET(regstart[*p])); IS_ACTIVE(reg_info[*p]) = 1; MATCHED_SOMETHING(reg_info[*p]) = 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; 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. */ 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])); 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; /* 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]) || (re_opcode_t) p[-3] == start_memory) && (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 ((long) old_regend[r] >= (long) 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; break; /* \ has been turned into a `duplicate' command which is * followed by the numeric value of as the register number. */ case duplicate: { register const char *d2, *dend2; int regno = *p++; /* Get which register to match against. */ DEBUG_PRINT2("EXECUTING duplicate %d.\n", regno); /* Can't back reference a group which we've never matched. */ if (REG_UNSET(regstart[regno]) || REG_UNSET(regend[regno])) goto fail; /* Where in input to try to start matching. */ d2 = regstart[regno]; /* Where to stop matching; if both the place to start and * the place to stop matching are in the same string, then * set to the place to stop, otherwise, for now have to use * the end of the first string. */ dend2 = ((FIRST_STRING_P(regstart[regno]) == FIRST_STRING_P(regend[regno])) ? regend[regno] : end_match_1); for (;;) { /* If necessary, advance to next segment in register * contents. */ while (d2 == dend2) { if (dend2 == end_match_2) break; if (dend2 == regend[regno]) break; /* End of string1 => advance to string2. */ d2 = string2; dend2 = regend[regno]; } /* At end of register contents => success */ if (d2 == dend2) break; /* If necessary, advance to next segment in data. */ PREFETCH(); /* How many characters left in this segment to match. */ mcnt = dend - d; /* Want how many consecutive characters we can match in * one shot, so, if necessary, adjust the count. */ if (mcnt > dend2 - d2) mcnt = dend2 - d2; /* Compare that many; failure if mismatch, else move * past them. */ if (translate ? bcmp_translate((unsigned char *)d, (unsigned char *)d2, mcnt, translate) : memcmp(d, d2, mcnt)) goto fail; d += mcnt, d2 += mcnt; } } break; /* begline matches the empty string at the beginning of the string * (unless `not_bol' is set in `bufp'), and, if * `newline_anchor' is set, after newlines. */ case begline: DEBUG_PRINT1("EXECUTING begline.\n"); if (AT_STRINGS_BEG(d)) { if (!bufp->not_bol) break; } else if (d[-1] == '\n' && bufp->newline_anchor) { break; } /* In all other cases, we fail. */ goto fail; /* endline is the dual of begline. */ case endline: DEBUG_PRINT1("EXECUTING endline.\n"); if (AT_STRINGS_END(d)) { if (!bufp->not_eol) break; } /* We have to ``prefetch'' the next character. */ else if ((d == end1 ? *string2 : *d) == '\n' && bufp->newline_anchor) { break; } goto fail; /* Match at the very beginning of the data. */ case begbuf: DEBUG_PRINT1("EXECUTING begbuf.\n"); if (AT_STRINGS_BEG(d)) break; goto fail; /* Match at the very end of the data. */ case endbuf: DEBUG_PRINT1("EXECUTING endbuf.\n"); if (AT_STRINGS_END(d)) break; goto fail; /* 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 * 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 * to do is match the \n against the \n; if we restored the * string value, we would be back at the foo. * * Because this is used only in specific cases, we don't need to * check all the things that `on_failure_jump' does, to make * sure the right things get saved on the stack. Hence we don't * share its code. The only reason to push anything on the * stack at all is that otherwise we would have to change * `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(" %d (to 0x%x):\n", mcnt, p + mcnt); PUSH_FAILURE_POINT(p + mcnt, NULL, -2); break; /* Uses of on_failure_jump: * * Each alternative starts with an on_failure_jump that points * to the beginning of the next alternative. Each alternative * except the last ends with a jump that in effect jumps past * the rest of the alternatives. (They really jump to the * ending jump of the following alternative, because tensioning * these jumps is a hassle.) * * Repeats start with an on_failure_jump that points past both * 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"); 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 \(\(a*\)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); break; /* A smart repeat ends with `maybe_pop_jump'. * We change it to either `pop_failure_jump' or `jump'. */ case maybe_pop_jump: EXTRACT_NUMBER_AND_INCR(mcnt, p); DEBUG_PRINT2("EXECUTING maybe_pop_jump %d.\n", 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. */ while (p2 + 2 < pend && ((re_opcode_t) * p2 == stop_memory || (re_opcode_t) * p2 == start_memory)) p2 += 3; /* Skip over args, too. */ /* 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 char c = *p2 == (unsigned char) endline ? '\n' : p2[2]; 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 ((re_opcode_t) p1[3] == exactn && p1[5] != c) { 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 (c < (unsigned char) (p1[4] * BYTEWIDTH) && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) not = !not; /* `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"); } } } } 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 long 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. */ /* Unconditionally jump (without popping any failure points). */ case jump: unconditional_jump: 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); 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: EXTRACT_NUMBER(mcnt, p + 2); DEBUG_PRINT2("EXECUTING succeed_n %d.\n", mcnt); assert(mcnt >= 0); /* Originally, this is how many times we HAVE to succeed. */ if (mcnt > 0) { mcnt--; p += 2; STORE_NUMBER_AND_INCR(p, mcnt); DEBUG_PRINT3(" Setting 0x%x to %d.\n", p, mcnt); } else if (mcnt == 0) { DEBUG_PRINT2(" Setting two bytes from 0x%x to no_op.\n", p + 2); p[2] = (unsigned char) no_op; p[3] = (unsigned char) no_op; goto on_failure; } break; case jump_n: EXTRACT_NUMBER(mcnt, p + 2); DEBUG_PRINT2("EXECUTING jump_n %d.\n", mcnt); /* Originally, this is how many times we CAN jump. */ if (mcnt) { mcnt--; STORE_NUMBER(p + 2, mcnt); goto unconditional_jump; } /* If don't have to jump any more, skip over the rest of command. */ else p += 4; break; case set_number_at: { DEBUG_PRINT1("EXECUTING set_number_at.\n"); 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); STORE_NUMBER(p1, mcnt); break; } case wordbound: DEBUG_PRINT1("EXECUTING wordbound.\n"); if (AT_WORD_BOUNDARY(d)) break; goto fail; case notwordbound: DEBUG_PRINT1("EXECUTING notwordbound.\n"); if (AT_WORD_BOUNDARY(d)) goto fail; break; case wordbeg: DEBUG_PRINT1("EXECUTING wordbeg.\n"); if (WORDCHAR_P(d) && (AT_STRINGS_BEG(d) || !WORDCHAR_P(d - 1))) break; goto fail; case wordend: DEBUG_PRINT1("EXECUTING wordend.\n"); if (!AT_STRINGS_BEG(d) && WORDCHAR_P(d - 1) && (!WORDCHAR_P(d) || AT_STRINGS_END(d))) break; goto fail; #ifdef emacs #ifdef emacs19 case before_dot: DEBUG_PRINT1("EXECUTING before_dot.\n"); if (PTR_CHAR_POS((unsigned char *) d) >= point) goto fail; break; case at_dot: DEBUG_PRINT1("EXECUTING at_dot.\n"); if (PTR_CHAR_POS((unsigned char *) d) != point) goto fail; break; case after_dot: DEBUG_PRINT1("EXECUTING after_dot.\n"); if (PTR_CHAR_POS((unsigned char *) d) <= point) goto fail; break; #else /* not emacs19 */ case at_dot: DEBUG_PRINT1("EXECUTING at_dot.\n"); if (PTR_CHAR_POS((unsigned char *) d) + 1 != point) goto fail; break; #endif /* not emacs19 */ case syntaxspec: DEBUG_PRINT2("EXECUTING syntaxspec %d.\n", mcnt); mcnt = *p++; goto matchsyntax; case wordchar: DEBUG_PRINT1("EXECUTING Emacs wordchar.\n"); mcnt = (int) Sword; matchsyntax: PREFETCH(); if (SYNTAX(*d++) != (enum syntaxcode) mcnt) goto fail; SET_REGS_MATCHED(); break; case notsyntaxspec: DEBUG_PRINT2("EXECUTING notsyntaxspec %d.\n", mcnt); mcnt = *p++; goto matchnotsyntax; case notwordchar: DEBUG_PRINT1("EXECUTING Emacs notwordchar.\n"); mcnt = (int) Sword; matchnotsyntax: PREFETCH(); if (SYNTAX(*d++) == (enum syntaxcode) mcnt) goto fail; SET_REGS_MATCHED(); break; #else /* not emacs */ case wordchar: DEBUG_PRINT1("EXECUTING non-Emacs wordchar.\n"); PREFETCH(); if (!WORDCHAR_P(d)) goto fail; SET_REGS_MATCHED(); d++; break; case notwordchar: DEBUG_PRINT1("EXECUTING non-Emacs notwordchar.\n"); PREFETCH(); if (WORDCHAR_P(d)) goto fail; SET_REGS_MATCHED(); d++; break; #endif /* not emacs */ default: abort(); } continue; /* Successfully executed one pattern command; keep going. */ /* We goto here if a matching operation fails. */ fail: if (!FAIL_STACK_EMPTY()) { /* 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 */ ; } } if (d >= string1 && d <= end1) dend = end_match_1; } else break; /* Matching at this starting point really fails. */ } /* for (;;) */ if (best_regs_set) goto restore_best_regs; FREE_VARIABLES(); return -1; /* Failure to match. */ } /* re_match_2 */ /* 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). */ boolean group_match_null_string_p(unsigned char **p, unsigned char *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. */ boolean alt_match_null_string_p(unsigned char *p, unsigned char *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. */ boolean common_op_match_null_string_p( unsigned char **p, unsigned char *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. */ int bcmp_translate(unsigned char const *s1, unsigned char const*s2, register int len, char *translate) { register unsigned char const *p1 = s1, *p2 = s2; while (len) { if (translate[*p1++] != translate[*p2++]) return 1; len--; } return 0; } /* Entry points for GNU code. */ /* re_compile_pattern is the GNU regular expression compiler: it * compiles PATTERN (of length SIZE) and puts the result in BUFP. * Returns 0 if the pattern was valid, otherwise an error string. * * Assumes the `allocated' (and perhaps `buffer') and `translate' fields * are set in BUFP on entry. * * We call regex_compile to do the actual compilation. */ const char * re_compile_pattern(pattern, length, bufp) const char *pattern; int length; struct re_pattern_buffer *bufp; { reg_errcode_t ret; /* GNU code is written to assume at least RE_NREGS registers will be set * (and at least one extra will be -1). */ bufp->regs_allocated = REGS_UNALLOCATED; /* And GNU code determines whether or not to get register information * by passing null for the REGS argument to re_match, etc., not by * setting no_sub. */ bufp->no_sub = 0; /* Match anchors at newline. */ bufp->newline_anchor = 1; ret = regex_compile(pattern, length, re_syntax_options, bufp); return re_error_msg[(int) ret]; } /* Entry points compatible with 4.2 BSD regex library. We don't define * them if this is an Emacs or POSIX compilation. */ #if !defined (emacs) && !defined (_POSIX_SOURCE) /* BSD has one and only one pattern buffer. */ static struct re_pattern_buffer re_comp_buf; char * re_comp(s) const char *s; { reg_errcode_t ret; if (!s) { if (!re_comp_buf.buffer) return (char *)"No previous regular expression"; return 0; } if (!re_comp_buf.buffer) { re_comp_buf.buffer = (unsigned char *) malloc(200); if (re_comp_buf.buffer == NULL) return (char *)"Memory exhausted"; re_comp_buf.allocated = 200; re_comp_buf.fastmap = (char *) malloc(1 << BYTEWIDTH); if (re_comp_buf.fastmap == NULL) return (char *)"Memory exhausted"; } /* Since `re_exec' always passes NULL for the `regs' argument, we * don't need to initialize the pattern buffer fields which affect it. */ /* Match anchors at newlines. */ re_comp_buf.newline_anchor = 1; ret = regex_compile(s, strlen(s), re_syntax_options, &re_comp_buf); /* Yes, we're discarding `const' here. */ return (char *) re_error_msg[(int) ret]; } int re_exec(s) const char *s; { const int len = strlen(s); return 0 <= re_search(&re_comp_buf, s, len, 0, len, (struct re_registers *) 0); } #endif /* not emacs and not _POSIX_SOURCE */ /* POSIX.2 functions. Don't define these for Emacs. */ #ifndef emacs /* regcomp takes a regular expression as a string and compiles it. * * PREG is a regex_t *. We do not expect any fields to be initialized, * since POSIX says we shouldn't. Thus, we set * * `buffer' to the compiled pattern; * `used' to the length of the compiled pattern; * `syntax' to RE_SYNTAX_POSIX_EXTENDED if the * REG_EXTENDED bit in CFLAGS is set; otherwise, to * RE_SYNTAX_POSIX_BASIC; * `newline_anchor' to REG_NEWLINE being set in CFLAGS; * `fastmap' and `fastmap_accurate' to zero; * `re_nsub' to the number of subexpressions in PATTERN. * * PATTERN is the address of the pattern string. * * CFLAGS is a series of bits which affect compilation. * * If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we * use POSIX basic syntax. * * If REG_NEWLINE is set, then . and [^...] don't match newline. * Also, regexec will try a match beginning after every newline. * * If REG_ICASE is set, then we considers upper- and lowercase * versions of letters to be equivalent when matching. * * If REG_NOSUB is set, then when PREG is passed to regexec, that * routine will report only success or failure, and nothing about the * registers. * * It returns 0 if it succeeds, nonzero if it doesn't. (See regex.h for * the return codes and their meanings.) */ int regcomp(preg, pattern, cflags) regex_t *preg; const char *pattern; int cflags; { reg_errcode_t ret; unsigned syntax = (cflags & REG_EXTENDED) ? RE_SYNTAX_POSIX_EXTENDED : RE_SYNTAX_POSIX_BASIC; /* regex_compile will allocate the space for the compiled pattern. */ preg->buffer = 0; preg->allocated = 0; /* Don't bother to use a fastmap when searching. This simplifies the * REG_NEWLINE case: if we used a fastmap, we'd have to put all the * characters after newlines into the fastmap. This way, we just try * every character. */ preg->fastmap = 0; if (cflags & REG_ICASE) { unsigned i; preg->translate = (char *) malloc(CHAR_SET_SIZE); if (preg->translate == NULL) return (int) REG_ESPACE; /* Map uppercase characters to corresponding lowercase ones. */ for (i = 0; i < CHAR_SET_SIZE; i++) preg->translate[i] = ISUPPER(i) ? tolower(i) : i; } else preg->translate = NULL; /* If REG_NEWLINE is set, newlines are treated differently. */ if (cflags & REG_NEWLINE) { /* REG_NEWLINE implies neither . nor [^...] match newline. */ syntax &= ~RE_DOT_NEWLINE; syntax |= RE_HAT_LISTS_NOT_NEWLINE; /* It also changes the matching behavior. */ preg->newline_anchor = 1; } else preg->newline_anchor = 0; preg->no_sub = !!(cflags & REG_NOSUB); /* POSIX says a null character in the pattern terminates it, so we * can use strlen here in compiling the pattern. */ ret = regex_compile(pattern, strlen(pattern), syntax, preg); /* POSIX doesn't distinguish between an unmatched open-group and an * unmatched close-group: both are REG_EPAREN. */ if (ret == REG_ERPAREN) ret = REG_EPAREN; return (int) ret; } /* regexec searches for a given pattern, specified by PREG, in the * string STRING. * * If NMATCH is zero or REG_NOSUB was set in the cflags argument to * `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at * least NMATCH elements, and we set them to the offsets of the * corresponding matched substrings. * * EFLAGS specifies `execution flags' which affect matching: if * REG_NOTBOL is set, then ^ does not match at the beginning of the * string; if REG_NOTEOL is set, then $ does not match at the end. * * We return 0 if we find a match and REG_NOMATCH if not. */ int regexec(preg, string, nmatch, pmatch, eflags) const regex_t *preg; const char *string; size_t nmatch; regmatch_t pmatch[]; int eflags; { int ret; struct re_registers regs; regex_t private_preg; int len = strlen(string); boolean want_reg_info = !preg->no_sub && nmatch > 0; private_preg = *preg; private_preg.not_bol = !!(eflags & REG_NOTBOL); private_preg.not_eol = !!(eflags & REG_NOTEOL); /* The user has told us exactly how many registers to return * information about, via `nmatch'. We have to pass that on to the * matching routines. */ private_preg.regs_allocated = REGS_FIXED; if (want_reg_info) { regs.num_regs = nmatch; regs.start = TALLOC(nmatch, regoff_t); regs.end = TALLOC(nmatch, regoff_t); if (regs.start == NULL || regs.end == NULL) return (int) REG_NOMATCH; } /* Perform the searching operation. */ ret = re_search(&private_preg, string, len, /* start: */ 0, /* range: */ len, want_reg_info ? ®s : (struct re_registers *) 0); /* Copy the register information to the POSIX structure. */ if (want_reg_info) { if (ret >= 0) { unsigned r; for (r = 0; r < nmatch; r++) { pmatch[r].rm_so = regs.start[r]; pmatch[r].rm_eo = regs.end[r]; } } /* If we needed the temporary register info, free the space now. */ free(regs.start); free(regs.end); } /* We want zero return to mean success, unlike `re_search'. */ return ret >= 0 ? (int) REG_NOERROR : (int) REG_NOMATCH; } /* Returns a message corresponding to an error code, ERRCODE, returned * from either regcomp or regexec. We don't use PREG here. */ size_t regerror(errcode, preg, errbuf, errbuf_size) int errcode; const regex_t *preg; char *errbuf; size_t errbuf_size; { const char *msg; size_t msg_size; if (errcode < 0 || errcode >= (sizeof(re_error_msg) / sizeof(re_error_msg[0]))) /* Only error codes returned by the rest of the code should be passed * to this routine. If we are given anything else, or if other regex * code generates an invalid error code, then the program has a bug. * Dump core so we can fix it. */ abort(); msg = re_error_msg[errcode]; /* POSIX doesn't require that we do anything in this case, but why * not be nice. */ if (!msg) msg = "Success"; msg_size = strlen(msg) + 1; /* Includes the null. */ if (errbuf_size != 0) { if (msg_size > errbuf_size) { strncpy(errbuf, msg, errbuf_size - 1); errbuf[errbuf_size - 1] = 0; } else strcpy(errbuf, msg); } return msg_size; } /* Free dynamically allocated space used by PREG. */ void regfree(preg) regex_t *preg; { if (preg->buffer != NULL) free(preg->buffer); preg->buffer = NULL; preg->allocated = 0; preg->used = 0; if (preg->fastmap != NULL) free(preg->fastmap); preg->fastmap = NULL; preg->fastmap_accurate = 0; if (preg->translate != NULL) free(preg->translate); preg->translate = NULL; } #endif /* not emacs */ /* * Local variables: * make-backup-files: t * version-control: t * trim-versions-without-asking: nil * End: */