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regexpr.c
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regexpr.c
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/*
regexpr.c
Author: Tatu Ylonen <[email protected]>
Copyright (c) 1991 Tatu Ylonen, Espoo, Finland
Permission to use, copy, modify, distribute, and sell this software
and its documentation for any purpose is hereby granted without fee,
provided that the above copyright notice appear in all copies. This
software is provided "as is" without express or implied warranty.
Created: Thu Sep 26 17:14:05 1991 ylo
Last modified: Mon Nov 4 17:06:48 1991 ylo
Ported to Think C: 19 Jan 1992 [email protected]
This code draws many ideas from the regular expression packages by
Henry Spencer of the University of Toronto and Richard Stallman of the
Free Software Foundation.
Emacs-specific code and syntax table code is almost directly borrowed
from GNU regexp.
*/
#include "myproto.h" /* For PROTO macro --Guido */
#include <stdio.h>
#include <assert.h>
#include "regexpr.h"
#ifdef THINK_C
/* Think C on the Mac really needs these headers... --Guido */
#include <stdlib.h>
#include <string.h>
#else
#ifdef __STDC__
/* Don't mess around, use the standard headers */
#include <stdlib.h>
#include <string.h>
#else
char *malloc();
void free();
char *realloc();
#endif /* __STDC__ */
#endif /* THINK_C */
#define MACRO_BEGIN do {
#define MACRO_END } while (0)
enum regexp_compiled_ops /* opcodes for compiled regexp */
{
Cend, /* end of pattern reached */
Cbol, /* beginning of line */
Ceol, /* end of line */
Cset, /* character set. Followed by 32 bytes of set. */
Cexact, /* followed by a byte to match */
Canychar, /* matches any character except newline */
Cstart_memory, /* set register start addr (followed by reg number) */
Cend_memory, /* set register end addr (followed by reg number) */
Cmatch_memory, /* match a duplicate of reg contents (regnum follows)*/
Cjump, /* followed by two bytes (lsb,msb) of displacement. */
Cstar_jump, /* will change to jump/update_failure_jump at runtime */
Cfailure_jump, /* jump to addr on failure */
Cupdate_failure_jump, /* update topmost failure point and jump */
Cdummy_failure_jump, /* push a dummy failure point and jump */
Cbegbuf, /* match at beginning of buffer */
Cendbuf, /* match at end of buffer */
Cwordbeg, /* match at beginning of word */
Cwordend, /* match at end of word */
Cwordbound, /* match if at word boundary */
Cnotwordbound, /* match if not at word boundary */
#ifdef emacs
Cemacs_at_dot, /* emacs only: matches at dot */
#endif /* emacs */
Csyntaxspec, /* matches syntax code (1 byte follows) */
Cnotsyntaxspec /* matches if syntax code does not match (1 byte foll)*/
};
enum regexp_syntax_op /* syntax codes for plain and quoted characters */
{
Rend, /* special code for end of regexp */
Rnormal, /* normal character */
Ranychar, /* any character except newline */
Rquote, /* the quote character */
Rbol, /* match beginning of line */
Reol, /* match end of line */
Roptional, /* match preceding expression optionally */
Rstar, /* match preceding expr zero or more times */
Rplus, /* match preceding expr one or more times */
Ror, /* match either of alternatives */
Ropenpar, /* opening parenthesis */
Rclosepar, /* closing parenthesis */
Rmemory, /* match memory register */
Rextended_memory, /* \vnn to match registers 10-99 */
Ropenset, /* open set. Internal syntax hard-coded below. */
/* the following are gnu extensions to "normal" regexp syntax */
Rbegbuf, /* beginning of buffer */
Rendbuf, /* end of buffer */
Rwordchar, /* word character */
Rnotwordchar, /* not word character */
Rwordbeg, /* beginning of word */
Rwordend, /* end of word */
Rwordbound, /* word bound */
Rnotwordbound, /* not word bound */
#ifdef emacs
Remacs_at_dot, /* emacs: at dot */
Remacs_syntaxspec, /* syntaxspec */
Remacs_notsyntaxspec, /* notsyntaxspec */
#endif /* emacs */
Rnum_ops
};
static int re_compile_initialized = 0;
static int regexp_syntax = 0;
int re_syntax = 0; /* Exported copy of regexp_syntax */
static unsigned char regexp_plain_ops[256];
static unsigned char regexp_quoted_ops[256];
static unsigned char regexp_precedences[Rnum_ops];
static int regexp_context_indep_ops;
static int regexp_ansi_sequences;
#define NUM_LEVELS 5 /* number of precedence levels in use */
#define MAX_NESTING 100 /* max nesting level of operators */
#ifdef emacs
/* This code is for emacs compatibility only. */
#include "config.h"
#include "lisp.h"
#include "buffer.h"
#include "syntax.h"
/* emacs defines NULL in some strange way? */
#undef NULL
#define NULL 0
#else /* emacs */
#define SYNTAX(ch) re_syntax_table[(unsigned char)(ch)]
#define Sword 1
#ifdef SYNTAX_TABLE
char *re_syntax_table;
#else
static char re_syntax_table[256];
#endif /* SYNTAX_TABLE */
#endif /* emacs */
static void re_compile_initialize PROTO((void));
static void re_compile_initialize()
{
int a;
#if !defined(emacs) && !defined(SYNTAX_TABLE)
static int syntax_table_inited = 0;
if (!syntax_table_inited)
{
syntax_table_inited = 1;
memset(re_syntax_table, 0, 256);
for (a = 'a'; a <= 'z'; a++)
re_syntax_table[a] = Sword;
for (a = 'A'; a <= 'Z'; a++)
re_syntax_table[a] = Sword;
for (a = '0'; a <= '9'; a++)
re_syntax_table[a] = Sword;
}
#endif /* !emacs && !SYNTAX_TABLE */
re_compile_initialized = 1;
for (a = 0; a < 256; a++)
{
regexp_plain_ops[a] = Rnormal;
regexp_quoted_ops[a] = Rnormal;
}
for (a = '0'; a <= '9'; a++)
regexp_quoted_ops[a] = Rmemory;
regexp_plain_ops['\134'] = Rquote;
if (regexp_syntax & RE_NO_BK_PARENS)
{
regexp_plain_ops['('] = Ropenpar;
regexp_plain_ops[')'] = Rclosepar;
}
else
{
regexp_quoted_ops['('] = Ropenpar;
regexp_quoted_ops[')'] = Rclosepar;
}
if (regexp_syntax & RE_NO_BK_VBAR)
regexp_plain_ops['\174'] = Ror;
else
regexp_quoted_ops['\174'] = Ror;
regexp_plain_ops['*'] = Rstar;
if (regexp_syntax & RE_BK_PLUS_QM)
{
regexp_quoted_ops['+'] = Rplus;
regexp_quoted_ops['?'] = Roptional;
}
else
{
regexp_plain_ops['+'] = Rplus;
regexp_plain_ops['?'] = Roptional;
}
if (regexp_syntax & RE_NEWLINE_OR)
regexp_plain_ops['\n'] = Ror;
regexp_plain_ops['\133'] = Ropenset;
regexp_plain_ops['\136'] = Rbol;
regexp_plain_ops['$'] = Reol;
regexp_plain_ops['.'] = Ranychar;
if (!(regexp_syntax & RE_NO_GNU_EXTENSIONS))
{
#ifdef emacs
regexp_quoted_ops['='] = Remacs_at_dot;
regexp_quoted_ops['s'] = Remacs_syntaxspec;
regexp_quoted_ops['S'] = Remacs_notsyntaxspec;
#endif /* emacs */
regexp_quoted_ops['w'] = Rwordchar;
regexp_quoted_ops['W'] = Rnotwordchar;
regexp_quoted_ops['<'] = Rwordbeg;
regexp_quoted_ops['>'] = Rwordend;
regexp_quoted_ops['b'] = Rwordbound;
regexp_quoted_ops['B'] = Rnotwordbound;
regexp_quoted_ops['`'] = Rbegbuf;
regexp_quoted_ops['\''] = Rendbuf;
}
if (regexp_syntax & RE_ANSI_HEX)
regexp_quoted_ops['v'] = Rextended_memory;
for (a = 0; a < Rnum_ops; a++)
regexp_precedences[a] = 4;
if (regexp_syntax & RE_TIGHT_VBAR)
{
regexp_precedences[Ror] = 3;
regexp_precedences[Rbol] = 2;
regexp_precedences[Reol] = 2;
}
else
{
regexp_precedences[Ror] = 2;
regexp_precedences[Rbol] = 3;
regexp_precedences[Reol] = 3;
}
regexp_precedences[Rclosepar] = 1;
regexp_precedences[Rend] = 0;
regexp_context_indep_ops = (regexp_syntax & RE_CONTEXT_INDEP_OPS) != 0;
regexp_ansi_sequences = (regexp_syntax & RE_ANSI_HEX) != 0;
}
int re_set_syntax(syntax)
int syntax;
{
int ret;
ret = regexp_syntax;
regexp_syntax = syntax;
re_syntax = syntax; /* Exported copy */
re_compile_initialize();
return ret;
}
static int hex_char_to_decimal PROTO((int));
static int hex_char_to_decimal(ch)
int ch;
{
if (ch >= '0' && ch <= '9')
return ch - '0';
if (ch >= 'a' && ch <= 'f')
return ch - 'a' + 10;
if (ch >= 'A' && ch <= 'F')
return ch - 'A' + 10;
return 16;
}
char *re_compile_pattern(regex, size, bufp)
char *regex;
int size;
regexp_t bufp;
{
int a, pos, op, current_level, level, opcode;
int pattern_offset, alloc;
int starts[NUM_LEVELS * MAX_NESTING], starts_base;
int future_jumps[MAX_NESTING], num_jumps;
unsigned char ch;
char *pattern, *translate;
int next_register, paren_depth, num_open_registers, open_registers[RE_NREGS];
int beginning_context;
#define NEXTCHAR(var) \
MACRO_BEGIN \
if (pos >= size) \
goto ends_prematurely; \
(var) = regex[pos]; \
pos++; \
MACRO_END
#define ALLOC(amount) \
MACRO_BEGIN \
if (pattern_offset+(amount) > alloc) \
{ \
alloc += 256 + (amount); \
pattern = realloc(pattern, alloc); \
if (!pattern) \
goto out_of_memory; \
} \
MACRO_END
#define STORE(ch) pattern[pattern_offset++] = (ch)
#define CURRENT_LEVEL_START (starts[starts_base + current_level])
#define SET_LEVEL_START starts[starts_base + current_level] = pattern_offset
#define PUSH_LEVEL_STARTS if (starts_base < (MAX_NESTING-1)*NUM_LEVELS) \
starts_base += NUM_LEVELS; \
else \
goto too_complex
#define POP_LEVEL_STARTS starts_base -= NUM_LEVELS
#define PUT_ADDR(offset,addr) \
MACRO_BEGIN \
int disp = (addr) - (offset) - 2; \
pattern[(offset)] = disp & 0xff; \
pattern[(offset)+1] = (disp>>8) & 0xff; \
MACRO_END
#define INSERT_JUMP(pos,type,addr) \
MACRO_BEGIN \
int a, p = (pos), t = (type), ad = (addr); \
for (a = pattern_offset - 1; a >= p; a--) \
pattern[a + 3] = pattern[a]; \
pattern[p] = t; \
PUT_ADDR(p+1,ad); \
pattern_offset += 3; \
MACRO_END
#define SETBIT(buf,offset,bit) (buf)[(offset)+(bit)/8] |= (1<<((bit) & 7))
#define SET_FIELDS \
MACRO_BEGIN \
bufp->allocated = alloc; \
bufp->buffer = pattern; \
bufp->used = pattern_offset; \
MACRO_END
#define GETHEX(var) \
MACRO_BEGIN \
char gethex_ch, gethex_value; \
NEXTCHAR(gethex_ch); \
gethex_value = hex_char_to_decimal(gethex_ch); \
if (gethex_value == 16) \
goto hex_error; \
NEXTCHAR(gethex_ch); \
gethex_ch = hex_char_to_decimal(gethex_ch); \
if (gethex_ch == 16) \
goto hex_error; \
(var) = gethex_value * 16 + gethex_ch; \
MACRO_END
#define ANSI_TRANSLATE(ch) \
MACRO_BEGIN \
switch (ch) \
{ \
case 'a': \
case 'A': \
ch = 7; /* audible bell */ \
break; \
case 'b': \
case 'B': \
ch = 8; /* backspace */ \
break; \
case 'f': \
case 'F': \
ch = 12; /* form feed */ \
break; \
case 'n': \
case 'N': \
ch = 10; /* line feed */ \
break; \
case 'r': \
case 'R': \
ch = 13; /* carriage return */ \
break; \
case 't': \
case 'T': \
ch = 9; /* tab */ \
break; \
case 'v': \
case 'V': \
ch = 11; /* vertical tab */ \
break; \
case 'x': /* hex code */ \
case 'X': \
GETHEX(ch); \
break; \
default: \
/* other characters passed through */ \
if (translate) \
ch = translate[(unsigned char)ch]; \
break; \
} \
MACRO_END
if (!re_compile_initialized)
re_compile_initialize();
bufp->used = 0;
bufp->fastmap_accurate = 0;
bufp->uses_registers = 0;
translate = bufp->translate;
pattern = bufp->buffer;
alloc = bufp->allocated;
if (alloc == 0 || pattern == NULL)
{
alloc = 256;
pattern = malloc(alloc);
if (!pattern)
goto out_of_memory;
}
pattern_offset = 0;
starts_base = 0;
num_jumps = 0;
current_level = 0;
SET_LEVEL_START;
num_open_registers = 0;
next_register = 1;
paren_depth = 0;
beginning_context = 1;
op = -1;
/* we use Rend dummy to ensure that pending jumps are updated (due to
low priority of Rend) before exiting the loop. */
pos = 0;
while (op != Rend)
{
if (pos >= size)
op = Rend;
else
{
NEXTCHAR(ch);
if (translate)
ch = translate[(unsigned char)ch];
op = regexp_plain_ops[(unsigned char)ch];
if (op == Rquote)
{
NEXTCHAR(ch);
op = regexp_quoted_ops[(unsigned char)ch];
if (op == Rnormal && regexp_ansi_sequences)
ANSI_TRANSLATE(ch);
}
}
level = regexp_precedences[op];
/* printf("ch='%c' op=%d level=%d current_level=%d curlevstart=%d\n",
ch, op, level, current_level, CURRENT_LEVEL_START); */
if (level > current_level)
{
for (current_level++; current_level < level; current_level++)
SET_LEVEL_START;
SET_LEVEL_START;
}
else
if (level < current_level)
{
current_level = level;
for (;num_jumps > 0 &&
future_jumps[num_jumps-1] >= CURRENT_LEVEL_START;
num_jumps--)
PUT_ADDR(future_jumps[num_jumps-1], pattern_offset);
}
switch (op)
{
case Rend:
break;
case Rnormal:
normal_char:
opcode = Cexact;
store_opcode_and_arg: /* opcode & ch must be set */
SET_LEVEL_START;
ALLOC(2);
STORE(opcode);
STORE(ch);
break;
case Ranychar:
opcode = Canychar;
store_opcode:
SET_LEVEL_START;
ALLOC(1);
STORE(opcode);
break;
case Rquote:
abort();
/*NOTREACHED*/
case Rbol:
if (!beginning_context)
if (regexp_context_indep_ops)
goto op_error;
else
goto normal_char;
opcode = Cbol;
goto store_opcode;
case Reol:
if (!((pos >= size) ||
((regexp_syntax & RE_NO_BK_VBAR) ?
(regex[pos] == '\174') :
(pos+1 < size && regex[pos] == '\134' &&
regex[pos+1] == '\174')) ||
((regexp_syntax & RE_NO_BK_PARENS)?
(regex[pos] == ')'):
(pos+1 < size && regex[pos] == '\134' &&
regex[pos+1] == ')'))))
if (regexp_context_indep_ops)
goto op_error;
else
goto normal_char;
opcode = Ceol;
goto store_opcode;
/* NOTREACHED */
break;
case Roptional:
if (beginning_context)
if (regexp_context_indep_ops)
goto op_error;
else
goto normal_char;
if (CURRENT_LEVEL_START == pattern_offset)
break; /* ignore empty patterns for ? */
ALLOC(3);
INSERT_JUMP(CURRENT_LEVEL_START, Cfailure_jump,
pattern_offset + 3);
break;
case Rstar:
case Rplus:
if (beginning_context)
if (regexp_context_indep_ops)
goto op_error;
else
goto normal_char;
if (CURRENT_LEVEL_START == pattern_offset)
break; /* ignore empty patterns for + and * */
ALLOC(9);
INSERT_JUMP(CURRENT_LEVEL_START, Cfailure_jump,
pattern_offset + 6);
INSERT_JUMP(pattern_offset, Cstar_jump, CURRENT_LEVEL_START);
if (op == Rplus) /* jump over initial failure_jump */
INSERT_JUMP(CURRENT_LEVEL_START, Cdummy_failure_jump,
CURRENT_LEVEL_START + 6);
break;
case Ror:
ALLOC(6);
INSERT_JUMP(CURRENT_LEVEL_START, Cfailure_jump,
pattern_offset + 6);
if (num_jumps >= MAX_NESTING)
goto too_complex;
STORE(Cjump);
future_jumps[num_jumps++] = pattern_offset;
STORE(0);
STORE(0);
SET_LEVEL_START;
break;
case Ropenpar:
SET_LEVEL_START;
if (next_register < RE_NREGS)
{
bufp->uses_registers = 1;
ALLOC(2);
STORE(Cstart_memory);
STORE(next_register);
open_registers[num_open_registers++] = next_register;
next_register++;
}
paren_depth++;
PUSH_LEVEL_STARTS;
current_level = 0;
SET_LEVEL_START;
break;
case Rclosepar:
if (paren_depth <= 0)
goto parenthesis_error;
POP_LEVEL_STARTS;
current_level = regexp_precedences[Ropenpar];
paren_depth--;
if (paren_depth < num_open_registers)
{
bufp->uses_registers = 1;
ALLOC(2);
STORE(Cend_memory);
num_open_registers--;
STORE(open_registers[num_open_registers]);
}
break;
case Rmemory:
if (ch == '0')
goto bad_match_register;
assert(ch >= '0' && ch <= '9');
bufp->uses_registers = 1;
opcode = Cmatch_memory;
ch -= '0';
goto store_opcode_and_arg;
case Rextended_memory:
NEXTCHAR(ch);
if (ch < '0' || ch > '9')
goto bad_match_register;
NEXTCHAR(a);
if (a < '0' || a > '9')
goto bad_match_register;
ch = 10 * (a - '0') + ch - '0';
if (ch <= 0 || ch >= RE_NREGS)
goto bad_match_register;
bufp->uses_registers = 1;
opcode = Cmatch_memory;
goto store_opcode_and_arg;
case Ropenset:
{
int complement,prev,offset,range,firstchar;
SET_LEVEL_START;
ALLOC(1+256/8);
STORE(Cset);
offset = pattern_offset;
for (a = 0; a < 256/8; a++)
STORE(0);
NEXTCHAR(ch);
if (translate)
ch = translate[(unsigned char)ch];
if (ch == '\136')
{
complement = 1;
NEXTCHAR(ch);
if (translate)
ch = translate[(unsigned char)ch];
}
else
complement = 0;
prev = -1;
range = 0;
firstchar = 1;
while (ch != '\135' || firstchar)
{
firstchar = 0;
if (regexp_ansi_sequences && ch == '\134')
{
NEXTCHAR(ch);
ANSI_TRANSLATE(ch);
}
if (range)
{
for (a = prev; a <= (int)ch; a++)
SETBIT(pattern, offset, a);
prev = -1;
range = 0;
}
else
if (prev != -1 && ch == '-')
range = 1;
else
{
SETBIT(pattern, offset, ch);
prev = ch;
}
NEXTCHAR(ch);
if (translate)
ch = translate[(unsigned char)ch];
}
if (range)
SETBIT(pattern, offset, '-');
if (complement)
{
for (a = 0; a < 256/8; a++)
pattern[offset+a] ^= 0xff;
}
break;
}
case Rbegbuf:
opcode = Cbegbuf;
goto store_opcode;
case Rendbuf:
opcode = Cendbuf;
goto store_opcode;
case Rwordchar:
opcode = Csyntaxspec;
ch = Sword;
goto store_opcode_and_arg;
case Rnotwordchar:
opcode = Cnotsyntaxspec;
ch = Sword;
goto store_opcode_and_arg;
case Rwordbeg:
opcode = Cwordbeg;
goto store_opcode;
case Rwordend:
opcode = Cwordend;
goto store_opcode;
case Rwordbound:
opcode = Cwordbound;
goto store_opcode;
case Rnotwordbound:
opcode = Cnotwordbound;
goto store_opcode;
#ifdef emacs
case Remacs_at_dot:
opcode = Cemacs_at_dot;
goto store_opcode;
case Remacs_syntaxspec:
NEXTCHAR(ch);
if (translate)
ch = translate[(unsigned char)ch];
opcode = Csyntaxspec;
ch = syntax_spec_code[(unsigned char)ch];
goto store_opcode_and_arg;
case Remacs_notsyntaxspec:
NEXTCHAR(ch);
if (translate)
ch = translate[(unsigned char)ch];
opcode = Cnotsyntaxspec;
ch = syntax_spec_code[(unsigned char)ch];
goto store_opcode_and_arg;
#endif /* emacs */
default:
abort();
}
beginning_context = (op == Ropenpar || op == Ror);
}
if (starts_base != 0)
goto parenthesis_error;
assert(num_jumps == 0);
ALLOC(1);
STORE(Cend);
SET_FIELDS;
return NULL;
op_error:
SET_FIELDS;
return "Badly placed special character";
bad_match_register:
SET_FIELDS;
return "Bad match register number";
hex_error:
SET_FIELDS;
return "Bad hexadecimal number";
parenthesis_error:
SET_FIELDS;
return "Badly placed parenthesis";
out_of_memory:
SET_FIELDS;
return "Out of memory";
ends_prematurely:
SET_FIELDS;
return "Regular expression ends prematurely";
too_complex:
SET_FIELDS;
return "Regular expression too complex";
}
#undef CHARAT
#undef NEXTCHAR
#undef GETHEX
#undef ALLOC
#undef STORE
#undef CURRENT_LEVEL_START
#undef SET_LEVEL_START
#undef PUSH_LEVEL_STARTS
#undef POP_LEVEL_STARTS
#undef PUT_ADDR
#undef INSERT_JUMP
#undef SETBIT
#undef SET_FIELDS
static void re_compile_fastmap_aux
PROTO((char *, int, char *, char *, char *));
static void re_compile_fastmap_aux(code, pos, visited, can_be_null, fastmap)
char *code, *visited, *can_be_null, *fastmap;
int pos;
{
int a, b, syntaxcode;
if (visited[pos])
return; /* we have already been here */
visited[pos] = 1;
for (;;)
switch (code[pos++])
{
case Cend:
*can_be_null = 1;
return;
case Cbol:
case Cbegbuf:
case Cendbuf:
case Cwordbeg:
case Cwordend:
case Cwordbound:
case Cnotwordbound:
#ifdef emacs
case Cemacs_at_dot:
#endif /* emacs */
break;
case Csyntaxspec:
syntaxcode = code[pos++];
for (a = 0; a < 256; a++)
if (SYNTAX(a) == syntaxcode)
fastmap[a] = 1;
return;
case Cnotsyntaxspec:
syntaxcode = code[pos++];
for (a = 0; a < 256; a++)
if (SYNTAX(a) != syntaxcode)
fastmap[a] = 1;
return;
case Ceol:
fastmap['\n'] = 1;
if (*can_be_null == 0)
*can_be_null = 2; /* can match null, but only at end of buffer*/
return;
case Cset:
for (a = 0; a < 256/8; a++)
if (code[pos + a] != 0)
for (b = 0; b < 8; b++)
if (code[pos + a] & (1 << b))
fastmap[(a << 3) + b] = 1;
pos += 256/8;
return;
case Cexact:
fastmap[(unsigned char)code[pos]] = 1;
return;
case Canychar:
for (a = 0; a < 256; a++)
if (a != '\n')
fastmap[a] = 1;
return;
case Cstart_memory:
case Cend_memory:
pos++;
break;
case Cmatch_memory:
/* should this ever happen for sensible patterns??? */
*can_be_null = 1;
return;
case Cjump:
case Cdummy_failure_jump:
case Cupdate_failure_jump:
case Cstar_jump:
a = (unsigned char)code[pos++];
a |= (unsigned char)code[pos++] << 8;
pos += (int)(short)a;
if (visited[pos])
{
/* argh... the regexp contains empty loops. This is not
good, as this may cause a failure stack overflow when
matching. Oh well. */
/* this path leads nowhere; pursue other paths. */
return;
}
visited[pos] = 1;
break;
case Cfailure_jump:
a = (unsigned char)code[pos++];
a |= (unsigned char)code[pos++] << 8;
a = pos + (int)(short)a;
re_compile_fastmap_aux(code, a, visited, can_be_null, fastmap);
break;
default:
abort(); /* probably some opcode is missing from this switch */
/*NOTREACHED*/
}
}
static int re_do_compile_fastmap PROTO((char *, int, int, char *, char *));
static int re_do_compile_fastmap(buffer, used, pos, can_be_null, fastmap)
char *buffer, *fastmap, *can_be_null;
int used, pos;
{
char small_visited[512], *visited;
if (used <= sizeof(small_visited))
visited = small_visited;
else
{
visited = malloc(used);
if (!visited)
return 0;
}
*can_be_null = 0;
memset(fastmap, 0, 256);
memset(visited, 0, used);
re_compile_fastmap_aux(buffer, pos, visited, can_be_null, fastmap);
if (visited != small_visited)
free(visited);
return 1;
}
void re_compile_fastmap(bufp)
regexp_t bufp;
{
if (!bufp->fastmap || bufp->fastmap_accurate)
return;
assert(bufp->used > 0);
if (!re_do_compile_fastmap(bufp->buffer, bufp->used, 0, &bufp->can_be_null,
bufp->fastmap))
return;
if (bufp->buffer[0] == Cbol)
bufp->anchor = 1; /* begline */
else
if (bufp->buffer[0] == Cbegbuf)
bufp->anchor = 2; /* begbuf */
else
bufp->anchor = 0; /* none */
bufp->fastmap_accurate = 1;
}
#define INITIAL_FAILURES 128 /* initial # failure points to allocate */
#define MAX_FAILURES 4100 /* max # of failure points before failing */
int re_match_2(bufp, string1, size1, string2, size2, pos, regs, mstop)
regexp_t bufp;
char *string1, *string2;
int size1, size2, pos, mstop;
regexp_registers_t regs;
{
struct failure_point { char *text, *partend, *code; }
*failure_stack_start, *failure_sp, *failure_stack_end,
initial_failure_stack[INITIAL_FAILURES];
char *code, *translate, *text, *textend, *partend, *part_2_end;
char *regstart_text[RE_NREGS], *regstart_partend[RE_NREGS];
char *regend_text[RE_NREGS], *regend_partend[RE_NREGS];
int a, b, ch, reg, regch, match_end;
char *regtext, *regpartend, *regtextend;
#define PREFETCH \
MACRO_BEGIN \
if (text == partend) \
{ \
if (text == textend) \
goto fail; \
text = string2; \
partend = part_2_end; \
} \
MACRO_END
#define NEXTCHAR(var) \
MACRO_BEGIN \
PREFETCH; \
(var) = (unsigned char)*text++; \
if (translate) \
(var) = (unsigned char)translate[(var)]; \
MACRO_END
assert(pos >= 0 && size1 >= 0 && size2 >= 0 && mstop >= 0);
assert(mstop <= size1 + size2);
assert(pos <= mstop);
if (pos <= size1)
{
text = string1 + pos;
if (mstop <= size1)
{
partend = string1 + mstop;
textend = partend;
}
else
{
partend = string1 + size1;
textend = string2 + mstop - size1;
}
part_2_end = string2 + mstop - size1;
}
else
{
text = string2 + pos - size1;
partend = string2 + mstop - size1;
textend = partend;
part_2_end = partend;
}
if (bufp->uses_registers && regs != NULL)
for (a = 0; a < RE_NREGS; a++)
regend_text[a] = NULL;
code = bufp->buffer;
translate = bufp->translate;
failure_stack_start = failure_sp = initial_failure_stack;
failure_stack_end = initial_failure_stack + INITIAL_FAILURES;
#if 0
/* re_search_2 has already done this, and otherwise we get little benefit
from this. So I'll leave this out. */
if (bufp->fastmap_accurate && !bufp->can_be_null &&
text != textend &&
!bufp->fastmap[translate ?
(unsigned char)translate[(unsigned char)*text] :
(unsigned char)*text])
return -1; /* it can't possibly match */
#endif
continue_matching:
for (;;)
{