regex.c

正则表达式库

  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 <stdio.h>

/* It is useful to test things that ``must'' be true when debugging.  */
#include <assert.h>

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.  */