lex.yy.c

词法分析lex.yy原代码

#else
YY_BUFFER_STATE yy_scan_string( yy_str )
yyconst char *yy_str;
#endif
	{
	int len;
	for ( len = 0; yy_str[len]; ++len )
		;

	return yy_scan_bytes( yy_str, len );
	}
#endif


#ifndef YY_NO_SCAN_BYTES
#ifdef YY_USE_PROTOS
YY_BUFFER_STATE yy_scan_bytes( yyconst char *bytes, int len )
#else
YY_BUFFER_STATE yy_scan_bytes( bytes, len )
yyconst char *bytes;
int len;
#endif
	{
	YY_BUFFER_STATE b;
	char *buf;
	yy_size_t n;
	int i;

	/* Get memory for full buffer, including space for trailing EOB's. */
	n = len + 2;
	buf = (char *) yy_flex_alloc( n );
	if ( ! buf )
		YY_FATAL_ERROR( "out of dynamic memory in yy_scan_bytes()" );

	for ( i = 0; i < len; ++i )
		buf[i] = bytes[i];

	buf[len] = buf[len+1] = YY_END_OF_BUFFER_CHAR;

	b = yy_scan_buffer( buf, n );
	if ( ! b )
		YY_FATAL_ERROR( "bad buffer in yy_scan_bytes()" );

	/* It's okay to grow etc. this buffer, and we should throw it
	 * away when we're done.
	 */
	b->yy_is_our_buffer = 1;

	return b;
	}
#endif


#ifndef YY_NO_PUSH_STATE
#ifdef YY_USE_PROTOS
static void yy_push_state( int new_state )
#else
static void yy_push_state( new_state )
int new_state;
#endif
	{
	if ( yy_start_stack_ptr >= yy_start_stack_depth )
		{
		yy_size_t new_size;

		yy_start_stack_depth += YY_START_STACK_INCR;
		new_size = yy_start_stack_depth * sizeof( int );

		if ( ! yy_start_stack )
			yy_start_stack = (int *) yy_flex_alloc( new_size );

		else
			yy_start_stack = (int *) yy_flex_realloc(
					(void *) yy_start_stack, new_size );

		if ( ! yy_start_stack )
			YY_FATAL_ERROR(
			"out of memory expanding start-condition stack" );
		}

	yy_start_stack[yy_start_stack_ptr++] = YY_START;

	BEGIN(new_state);
	}
#endif


#ifndef YY_NO_POP_STATE
static void yy_pop_state()
	{
	if ( --yy_start_stack_ptr < 0 )
		YY_FATAL_ERROR( "start-condition stack underflow" );

	BEGIN(yy_start_stack[yy_start_stack_ptr]);
	}
#endif


#ifndef YY_NO_TOP_STATE
static int yy_top_state()
	{
	return yy_start_stack[yy_start_stack_ptr - 1];
	}
#endif

#ifndef YY_EXIT_FAILURE
#define YY_EXIT_FAILURE 2
#endif

#ifdef YY_USE_PROTOS
static void yy_fatal_error( yyconst char msg[] )
#else
static void yy_fatal_error( msg )
char msg[];
#endif
	{
	(void) fprintf( stderr, "%s\n", msg );
	exit( YY_EXIT_FAILURE );
	}



/* Redefine yyless() so it works in section 3 code. */

#undef yyless
#define yyless(n) \
	do \
		{ \
		/* Undo effects of setting up yytext. */ \
		yytext[yyleng] = yy_hold_char; \
		yy_c_buf_p = yytext + n; \
		yy_hold_char = *yy_c_buf_p; \
		*yy_c_buf_p = '\0'; \
		yyleng = n; \
		} \
	while ( 0 )


/* Internal utility routines. */

#ifndef yytext_ptr
#ifdef YY_USE_PROTOS
static void yy_flex_strncpy( char *s1, yyconst char *s2, int n )
#else
static void yy_flex_strncpy( s1, s2, n )
char *s1;
yyconst char *s2;
int n;
#endif
	{
	register int i;
	for ( i = 0; i < n; ++i )
		s1[i] = s2[i];
	}
#endif

#ifdef YY_NEED_STRLEN
#ifdef YY_USE_PROTOS
static int yy_flex_strlen( yyconst char *s )
#else
static int yy_flex_strlen( s )
yyconst char *s;
#endif
	{
	register int n;
	for ( n = 0; s[n]; ++n )
		;

	return n;
	}
#endif


#ifdef YY_USE_PROTOS
static void *yy_flex_alloc( yy_size_t size )
#else
static void *yy_flex_alloc( size )
yy_size_t size;
#endif
	{
	return (void *) malloc( size );
	}

#ifdef YY_USE_PROTOS
static void *yy_flex_realloc( void *ptr, yy_size_t size )
#else
static void *yy_flex_realloc( ptr, size )
void *ptr;
yy_size_t size;
#endif
	{
	/* The cast to (char *) in the following accommodates both
	 * implementations that use char* generic pointers, and those
	 * that use void* generic pointers.  It works with the latter
	 * because both ANSI C and C++ allow castless assignment from
	 * any pointer type to void*, and deal with argument conversions
	 * as though doing an assignment.
	 */
	return (void *) realloc( (char *) ptr, size );
	}

#ifdef YY_USE_PROTOS
static void yy_flex_free( void *ptr )
#else
static void yy_flex_free( ptr )
void *ptr;
#endif
	{
	free( ptr );
	}

#if YY_MAIN
int main()
	{
	yylex();
	return 0;
	}
#endif
#line 316 "scanner.l"




#ifdef __STDC__
void
initialize_scanner (FILE *in_file)
#else
void
initialize_scanner (in_file)
     FILE *in_file;
#endif
{
  yyin = in_file;
#ifdef FLEX_SCANNER
  yyrestart(in_file);
  yy_init = 1;
#endif
  line_no = 1;
  current_line = NULL;
  line_returned = 0;
  eof_returned = 0;
}


#ifdef __STDC__
void
scanner_start_line (void)
#else
void
scanner_start_line ()
#endif
{
  current_line = NULL;
  line_returned = 0;
}


/* Use yywrap to insert a marker character, which causes the
   scanner to return Y_EOF, before return a hard EOF.  This
   wouldn't be necessary, except that bison does not allow
   the parser to use EOF (= 0) as a non-terminal */

int yywrap()
{
	if (eof_returned)
		return (1);
	else
	{
		unput ('\001');
		eof_returned = 1;
#ifdef FLEX_SCANNER
		yy_did_buffer_switch_on_eof = 1;
#endif
		return (0);
	}
}


/* Return a freshly-allocated copy of STRING with the last CHOP
   characters removed. */

#ifdef __STDC__
static YY_CHAR *
copy_str (YY_CHAR *str, int chop)
#else
static YY_CHAR *
copy_str (str, chop)
     YY_CHAR *str;
     int chop;
#endif
{
  register int new_len = strlen (str) - chop;
  register YY_CHAR *new_str = (YY_CHAR *) xmalloc (new_len + 1), *n;

  for (n = new_str; *str != '\0' && new_len > 0; new_len -= 1)
    if (*str == '\\')
      switch (*(str + 1))
	{
	case 'n':
	  {
	    *n ++ = '\n';
	    str += 2;
	    new_len -= 1;
	    continue;
	  }
	case 't':
	  {
	    *n ++ = '\t';
	    str += 2;
	    new_len -= 1;
	    continue;
	  }
	case '"':
	  {
	    *n ++ = '"';
	    str += 2;
	    new_len -= 1;
	    continue;
	  }
	case 'X':
	  {
	    YY_CHAR c1 = *(str + 2), c2 = *(str + 3);
	    int b = 0;

	    if ('0' <= c1 && c1 <= '9') b = c1 - '0';
	    else if ('A' <= c1 && c1 <= 'F') b = c1 - 'A' + 10;
	    else yyerror ("Bad character in \\X construct in string");

	    b <<= 4;
	    if ('0' <= c2 && c2 <= '9') b += c2 - '0';
	    else if ('A' <= c2 && c2 <= 'F') b += c2 - 'A' + 10;
	    else yyerror ("Bad character in \\X construct in string");

	    *n ++ = (YY_CHAR) b;
	    str += 4;
	    new_len -= 3;
	    continue;
	  }
	default:
	  {
	    *n ++ = *str ++;
	    continue;
	  }
	}
    else
      *n ++ = *str ++;

  *n = '\0';
  y_str_length = n - new_str;
  return (new_str);
}


/* On a parse error, write out the current line and print a caret (^)
   below the point at which the error occured.	Also, reset the input
   stream to the begining of the next line. */

#ifdef __STDC__
void
print_erroneous_line (void)
#else
void
print_erroneous_line ()
#endif
{
  int prefix_length = yytext - current_line;
  int i, c;
  YY_CHAR buffer[1024], *bp = buffer;

  if (current_line == NULL) return;

  error ("	  ");
  c = *(current_line + prefix_length);
  *(current_line + prefix_length) = '\0';
  error ("%s", current_line);
  *(current_line + prefix_length) = (char)c;
  error ("%s", yytext);

  /* Flush the rest of the line. */
  if (*yytext != '\n')
    {
      while ((c = input ()) != '\n' && c != EOF)
	*bp ++ = (char)c;
      *bp = '\0';
      error ("%s\n", buffer);
      if (c == '\n') unput ('\n');
      current_line = NULL;
    }


  if (1024 <= prefix_length) return;

  error ("	  ");
  for (i = 0; i < prefix_length; i ++) buffer[i] = ' ';
  buffer[i] = '\0';
  error ("%s^\n", buffer);
}


static inst_info keyword_tbl [] = {
#undef OP
#define OP(NAME, OPCODE, TYPE, R_OPCODE) {NAME, OPCODE, TYPE},
#include "op.h"
};


#ifdef __STDC__
static int
check_keyword (YY_CHAR *id, int allow_pseudo_ops)
#else
static int
check_keyword (id, allow_pseudo_ops)
     YY_CHAR *id;
     int allow_pseudo_ops;
#endif
{
  inst_info *entry =
    map_string_to_inst_info (keyword_tbl,
			     sizeof(keyword_tbl) / sizeof (inst_info),
			     id);
  if (entry == NULL)
    return (0);
  else if (!allow_pseudo_ops && entry->value2 == PSEUDO_OP)
    return (0);
  else
    return (entry->value1);
}


static inst_info register_tbl [] = {
  {"a0", 4, 0},
  {"a1", 5, 0},
  {"a2", 6, 0},
  {"a3", 7, 0},
  {"at", 1, 0},
  {"fp", 30, 0},
  {"gp", 28, 0},
  {"k0", 26, 0},
  {"k1", 27, 0},
  {"kt0", 26, 0},
  {"kt1", 27, 0},
  {"ra", 31, 0},
  {"s0", 16, 0},
  {"s1", 17, 0},
  {"s2", 18, 0},
  {"s3", 19, 0},
  {"s4", 20, 0},
  {"s5", 21, 0},
  {"s6", 22, 0},
  {"s7", 23, 0},
  {"s8", 30, 0},
  {"sp", 29, 0},
  {"t0", 8, 0},
  {"t1", 9, 0},
  {"t2", 10, 0},
  {"t3", 11, 0},
  {"t4", 12, 0},
  {"t5", 13, 0},
  {"t6", 14, 0},
  {"t7", 15, 0},
  {"t8", 24, 0},
  {"t9", 25, 0},
  {"v0", 2, 0},
  {"v1", 3, 0},
  {"zero", 0, 0}
};


#ifdef __STDC__
int
register_name_to_number (char *name)
#else
int
register_name_to_number (name)
     char *name;
#endif
{
  register int c1 = *name, c2 = *(name + 1);

  if ('0' <= c1 && c1 <= '9'
      && (c2 == '\0' || (('0' <= c2 && c2 <= '9') && *(name + 2) == '\0')))
    return (atoi (name));
  else if (c1 == 'f' && c2 >= '0' && c2 <= '9')
    return atoi (name + 1);
  else
    {
      inst_info *entry =
	map_string_to_inst_info (register_tbl,
				 sizeof (register_tbl) / sizeof (inst_info),
				 name);
      if (entry == NULL)
	return (-1);
      else
	return (entry->value1);
    }
}


/* Exactly once, return the current source line, as a printable string
   with a line number.  Subsequent calls receive NULL instead of the
   line. */

#ifdef __STDC__
char *
source_line ()
#else
char *
source_line ()
#endif
{
  if (line_returned)
    return (NULL);
  else if (current_line == NULL)	/* Error on line */
    return (NULL);
  else
    {
      YY_CHAR *eol1, c1;
      YY_CHAR *null1 = NULL;
      char *r;

      /* Find end of line: */
      for (eol1 = current_line; *eol1 != '\0' && *eol1 != '\n'; ) eol1 += 1;

      /* Ran into null byte, inserted by yylex. In necessary, look further
	 for newline */
      if (*eol1 == '\0' && yy_hold_char != '\n')
	{
	  null1 = eol1;
	  *eol1 = yy_hold_char;
	  for ( ; *eol1 != '\0' && *eol1 != '\n'; )
	    eol1 += 1;
	}

      /* Save end-of-line character and null terminate string so it can
	 be printed. */
      c1 = *eol1;
      *eol1 = '\0';

      r = (char *) xmalloc (eol1 - current_line + 10);
      sprintf (r, "%d: %s", current_line_no, current_line);

      /* Restore end-of-line character and, if necessary, yylex's null byte. */
      *eol1 = c1;
      if (null1 != NULL)
	{
	  *null1 = '\0';
	}
      line_returned = 1;
      return ((char *) r);
    }
}