gdb/regex.h

   1 /* Definitions for data structures callers pass the regex library.
   2    Copyright (C) 1985, 1989 Free Software Foundation, Inc.
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation; either version 2 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 /* Define number of parens for which we record the beginnings and ends.
  19    This affects how much space the `struct re_registers' type takes up.  */
  20 #ifndef RE_NREGS
  21 #define RE_NREGS 10
  22 #endif
  23
  24 /* These bits are used in the obscure_syntax variable to choose among
  25    alternative regexp syntaxes.  */
  26
  27 /* 1 means plain parentheses serve as grouping, and backslash
  28      parentheses are needed for literal searching.
  29    0 means backslash-parentheses are grouping, and plain parentheses
  30      are for literal searching.  */
  31 #define RE_NO_BK_PARENS 1
  32
  33 /* 1 means plain | serves as the "or"-operator, and \| is a literal.
  34    0 means \| serves as the "or"-operator, and | is a literal.  */
  35 #define RE_NO_BK_VBAR 2
  36
  37 /* 0 means plain + or ? serves as an operator, and \+, \? are literals.
  38    1 means \+, \? are operators and plain +, ? are literals.  */
  39 #define RE_BK_PLUS_QM 4
  40
  41 /* 1 means | binds tighter than ^ or $.
  42    0 means the contrary.  */
  43 #define RE_TIGHT_VBAR 8
  44
  45 /* 1 means treat \n as an _OR operator
  46    0 means treat it as a normal character */
  47 #define RE_NEWLINE_OR 16
  48
  49 /* 0 means that a special characters (such as *, ^, and $) always have
  50      their special meaning regardless of the surrounding context.
  51    1 means that special characters may act as normal characters in some
  52      contexts.  Specifically, this applies to:
  53         ^ - only special at the beginning, or after ( or |
  54         $ - only special at the end, or before ) or |
  55         *, +, ? - only special when not after the beginning, (, or | */
  56 #define RE_CONTEXT_INDEP_OPS 32
  57
  58 /* Now define combinations of bits for the standard possibilities.  */
  59 #define RE_SYNTAX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR | RE_CONTEXT_INDEP_OPS)
  60 #define RE_SYNTAX_EGREP (RE_SYNTAX_AWK | RE_NEWLINE_OR)
  61 #define RE_SYNTAX_GREP (RE_BK_PLUS_QM | RE_NEWLINE_OR)
  62 #define RE_SYNTAX_EMACS 0
  63
  64 /* This data structure is used to represent a compiled pattern. */
  65
  66 struct re_pattern_buffer
  67   {
  68     char *buffer;       /* Space holding the compiled pattern commands. */
  69     int allocated;      /* Size of space that  buffer  points to */
  70     int used;           /* Length of portion of buffer actually occupied */
  71     char *fastmap;      /* Pointer to fastmap, if any, or zero if none. */
  72                         /* re_search uses the fastmap, if there is one,
  73                            to skip quickly over totally implausible characters */
  74     char *translate;    /* Translate table to apply to all characters before comparing.
  75                            Or zero for no translation.
  76                            The translation is applied to a pattern when it is compiled
  77                            and to data when it is matched. */
  78     char fastmap_accurate;
  79                         /* Set to zero when a new pattern is stored,
  80                            set to one when the fastmap is updated from it. */
  81     char can_be_null;   /* Set to one by compiling fastmap
  82                            if this pattern might match the null string.
  83                            It does not necessarily match the null string
  84                            in that case, but if this is zero, it cannot.
  85                            2 as value means can match null string
  86                            but at end of range or before a character
  87                            listed in the fastmap.  */
  88   };
  89
  90 /* Structure to store "register" contents data in.
  91
  92    Pass the address of such a structure as an argument to re_match, etc.,
  93    if you want this information back.
  94
  95    start[i] and end[i] record the string matched by \( ... \) grouping i,
  96    for i from 1 to RE_NREGS - 1.
  97    start[0] and end[0] record the entire string matched. */
  98
  99 struct re_registers
 100   {
 101     int start[RE_NREGS];
 102     int end[RE_NREGS];
 103   };
 104
 105 /* These are the command codes that appear in compiled regular expressions, one per byte.
 106   Some command codes are followed by argument bytes.
 107   A command code can specify any interpretation whatever for its arguments.
 108   Zero-bytes may appear in the compiled regular expression. */
 109
 110 enum regexpcode
 111   {
 112     unused,
 113     exactn,    /* followed by one byte giving n, and then by n literal bytes */
 114     begline,   /* fails unless at beginning of line */
 115     endline,   /* fails unless at end of line */
 116     jump,        /* followed by two bytes giving relative address to jump to */
 117     on_failure_jump,     /* followed by two bytes giving relative address of place
 118                             to resume at in case of failure. */
 119     finalize_jump,       /* Throw away latest failure point and then jump to address. */
 120     maybe_finalize_jump, /* Like jump but finalize if safe to do so.
 121                             This is used to jump back to the beginning
 122                             of a repeat.  If the command that follows
 123                             this jump is clearly incompatible with the
 124                             one at the beginning of the repeat, such that
 125                             we can be sure that there is no use backtracking
 126                             out of repetitions already completed,
 127                             then we finalize. */
 128     dummy_failure_jump,  /* jump, and push a dummy failure point.
 129                             This failure point will be thrown away
 130                             if an attempt is made to use it for a failure.
 131                             A + construct makes this before the first repeat.  */
 132     anychar,     /* matches any one character */
 133     charset,     /* matches any one char belonging to specified set.
 134                     First following byte is # bitmap bytes.
 135                     Then come bytes for a bit-map saying which chars are in.
 136                     Bits in each byte are ordered low-bit-first.
 137                     A character is in the set if its bit is 1.
 138                     A character too large to have a bit in the map
 139                     is automatically not in the set */
 140     charset_not, /* similar but match any character that is NOT one of those specified */
 141     start_memory, /* starts remembering the text that is matched
 142                     and stores it in a memory register.
 143                     followed by one byte containing the register number.
 144                     Register numbers must be in the range 0 through NREGS. */
 145     stop_memory, /* stops remembering the text that is matched
 146                     and stores it in a memory register.
 147                     followed by one byte containing the register number.
 148                     Register numbers must be in the range 0 through NREGS. */
 149     duplicate,    /* match a duplicate of something remembered.
 150                     Followed by one byte containing the index of the memory register. */
 151     before_dot,  /* Succeeds if before dot */
 152     at_dot,      /* Succeeds if at dot */
 153     after_dot,   /* Succeeds if after dot */
 154     begbuf,      /* Succeeds if at beginning of buffer */
 155     endbuf,      /* Succeeds if at end of buffer */
 156     wordchar,    /* Matches any word-constituent character */
 157     notwordchar, /* Matches any char that is not a word-constituent */
 158     wordbeg,     /* Succeeds if at word beginning */
 159     wordend,     /* Succeeds if at word end */
 160     wordbound,   /* Succeeds if at a word boundary */
 161     notwordbound, /* Succeeds if not at a word boundary */
 162     syntaxspec,  /* Matches any character whose syntax is specified.
 163                     followed by a byte which contains a syntax code, Sword or such like */
 164     notsyntaxspec /* Matches any character whose syntax differs from the specified. */
 165   };
 166 \f
 167 extern char *re_compile_pattern ();
 168 /* Is this really advertised? */
 169 extern void re_compile_fastmap ();
 170 extern int re_search (), re_search_2 ();
 171 extern int re_match (), re_match_2 ();
 172
 173 /* 4.2 bsd compatibility (yuck) */
 174 extern char *re_comp ();
 175 extern int re_exec ();
 176
 177 #ifdef SYNTAX_TABLE
 178 extern char *re_syntax_table;
 179 #endif
 180
 181 extern int re_set_syntax ();