lex.yy.c

Spim软件的一些源码。其中有Xspim的

	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 302 "d:\\Jim\\Software\\Spim\\Cpu\\scanner.l"




void
initialize_scanner (FILE *in_file)
{
  yyin = in_file;
#ifdef FLEX_SCANNER
  yyrestart(in_file);
#if (YY_FLEX_MAJOR_VERSION==2 && YY_FLEX_MINOR_VERSION==5 && YY_FLEX_SUBMINOR_VERSION==33)
  /* flex 2.5.33 flips the polarity of this flag (sigh) */
  yy_init = 0;
#else
  yy_init = 1;
#endif
#endif
  line_no = 1;
  current_line = NULL;
  line_returned = 0;
  eof_returned = 0;
}


void
scanner_start_line ()
{
  current_line = NULL;
  line_returned = 0;
}


/* This is a work-around for a bug in flex v 2.5.31 (but not earlier or
   later versions such as 2.5.4) that left this symbol undefined. */

#ifndef yytext_ptr
#define yytext_ptr yytext
#endif


/* 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);
	}
}


/* A backslash has just been read, return the character designated by *STR.  */

static YY_CHAR
scan_escape (YY_CHAR **str)
{
  YY_CHAR first = **str;
  *str += 1;
  switch (first)
    {
    case 'a': return '\a';
    case 'b': return '\b';
    case 'f': return '\f';
    case 'n': return '\n';
    case 'r': return '\r';
    case 't': return '\t';
    case '\\': return '\\';
    case '"': return '"';
    case '\'': return '\'';

    case 'x':
    case 'X':
      {
	YY_CHAR c1 = **str, c2 = *(*str + 1);
	int b = 0;

	if ('0' <= c1 && c1 <= '9') b = c1 - '0';
	else if ('A' <= c1 && c1 <= 'F') b = c1 - 'A' + 10;
	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 if ('a' <= c2 && c2 <= 'f') b += c2 - 'a' + 10;
	else yyerror ("Bad character in \\X construct in string");

	*str += 2;
	return (YY_CHAR) b;
      }

    default:
      {
	char message[] = "Bad character \\X";
	message[strlen (message) - 1] = first;
	yyerror (message);
	return '\0';
      }
    }
}


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

static YY_CHAR *
copy_str (YY_CHAR *str, int chop)
{
  int new_len = strlen (str) - chop;
  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 '0':		/* \nnn */
	case '1':
	case '2':
	case '3':
	  {
	    YY_CHAR c2 = *(str + 2), c3 = *(str + 3);
	    int b = (*(str + 1) - '0') << 3;

	    if ('0' <= c2 && c2 <= '7')
	      b = (c2 - '0') << 3;
	    else
	      yyerror ("Bad character in \\ooo construct in string");

	    if ('0' <= c3 && c3 <= '7')
	      b += c3 - '0';
	    else
	      yyerror ("Bad character in \\ooo construct in string");

	    *n ++ = (YY_CHAR) b;
	    str += 4;
	    new_len -= 3;
	    continue;
	  }
	case 'X':
	  {
	    YY_CHAR c2 = *(str + 2), c3 = *(str + 3);
	    int b = 0;

	    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");

	    b <<= 4;
	    if ('0' <= c3 && c3 <= '9')
	      b += c3 - '0';
	    else if ('A' <= c3 && c3 <= 'F')
	      b += c3 - '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';
  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. */

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

  if (current_line == NULL) return;

  /* Print part of line that has been consumed. */
  if (0 <= prefix_length)
    {
      /* yytext and current_line point to same line */
      error ("	  ");
      c = *(current_line + prefix_length);
      *(current_line + prefix_length) = '\0';
      error ("%s", current_line);
      *(current_line + prefix_length) = (char)c;
      error ("%s", yytext);
    }
  else
    {
      /* yytext and current_line point to different lines */
      error ("	  ");
      error ("%s", current_line);
      prefix_length = strlen(current_line);
    }

  /* Flush the rest of the line (not consumed) from lex input. */
  if (*yytext != '\n')
    {
      while ((c = input ()) != '\n' && c != EOF && c != 1)
	*bp ++ = (char)c;
      *bp = '\0';
      error ("%s\n", buffer);
      if (c == '\n') unput ('\n');
      current_line = NULL;
    }

  /* Print marker to point at which consumption stopped. */
  if (1024 <= prefix_length) return;
  error ("	  ");
  for (i = 0; i < prefix_length; i ++) buffer[i] = ' ';
  buffer[i] = '\0';
  error ("%s^\n", buffer);
}


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


static int
check_keyword (YY_CHAR *id, int allow_pseudo_ops)
{
  name_val_val *entry =
    map_string_to_name_val_val (keyword_tbl,
			     sizeof(keyword_tbl) / sizeof (name_val_val),
			     id);
  if (entry == NULL)
    return (0);
  else if (!allow_pseudo_ops && entry->value2 == PSEUDO_OP)
    return (0);
  else
    return (entry->value1);
}


static name_val_val 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}
};

int
register_name_to_number (char *name)
{
  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
    {
      name_val_val *entry =
	map_string_to_name_val_val (register_tbl,
				 sizeof (register_tbl) / sizeof (name_val_val),
				 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. */

char *
source_line ()
{
  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;

#ifdef FLEX_SCANNER
      /* Ran into null byte, inserted by yylex. In necessary, look further
	 for newline. (This only works for scanners produced by flex. Other
         versions of lex need similar code, or source code lines will end
         early. */
      if (*eol1 == '\0' && yy_hold_char != '\n')
	{
	  null1 = eol1;
	  *eol1 = yy_hold_char;
	  for ( ; *eol1 != '\0' && *eol1 != '\n'; )
	    eol1 += 1;
	}
#endif

      /* 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);
    }
}