misc.c

flex编译器的源代码

	action_offset = prolog_offset = action_index;
	action_array[action_index] = '\0';
	}


/* mark_prolog - mark the current position in the action array as
 *               representing the end of the action prolog
 */
void mark_prolog()
	{
	action_array[action_index++] = '\0';
	action_offset = action_index;
	action_array[action_index] = '\0';
	}


/* mk2data - generate a data statement for a two-dimensional array
 *
 * Generates a data statement initializing the current 2-D array to "value".
 */
void mk2data( value )
int value;
	{
	if ( datapos >= NUMDATAITEMS )
		{
		outc( ',' );
		dataflush();
		}

	if ( datapos == 0 )
		/* Indent. */
		out( "    " );

	else
		outc( ',' );

	++datapos;

	out_dec( "%5d", value );
	}


/* mkdata - generate a data statement
 *
 * Generates a data statement initializing the current array element to
 * "value".
 */
void mkdata( value )
int value;
	{
	if ( datapos >= NUMDATAITEMS )
		{
		outc( ',' );
		dataflush();
		}

	if ( datapos == 0 )
		/* Indent. */
		out( "    " );
	else
		outc( ',' );

	++datapos;

	out_dec( "%5d", value );
	}


/* myctoi - return the integer represented by a string of digits */

int myctoi( array )
char array[];
	{
	int val = 0;

	(void) sscanf( array, "%d", &val );

	return val;
	}


/* myesc - return character corresponding to escape sequence */

Char myesc( array )
Char array[];
	{
	Char c, esc_char;

	switch ( array[1] )
		{
		case 'b': return '\b';
		case 'f': return '\f';
		case 'n': return '\n';
		case 'r': return '\r';
		case 't': return '\t';

#if __STDC__
		case 'a': return '\a';
		case 'v': return '\v';
#else
		case 'a': return '\007';
		case 'v': return '\013';
#endif

		case '0':
		case '1':
		case '2':
		case '3':
		case '4':
		case '5':
		case '6':
		case '7':
			{ /* \<octal> */
			int sptr = 1;

			while ( isascii( array[sptr] ) &&
				isdigit( array[sptr] ) )
				/* Don't increment inside loop control
				 * because if isdigit() is a macro it might
				 * expand into multiple increments ...
				 */
				++sptr;

			c = array[sptr];
			array[sptr] = '\0';

			esc_char = otoi( array + 1 );

			array[sptr] = c;

			return esc_char;
			}

		case 'x':
			{ /* \x<hex> */
			int sptr = 2;

			while ( isascii( array[sptr] ) &&
				isxdigit( (char) array[sptr] ) )
				/* Don't increment inside loop control
				 * because if isdigit() is a macro it might
				 * expand into multiple increments ...
				 */
				++sptr;

			c = array[sptr];
			array[sptr] = '\0';

			esc_char = htoi( array + 2 );

			array[sptr] = c;

			return esc_char;
			}

		default:
			return array[1];
		}
	}


/* otoi - convert an octal digit string to an integer value */

int otoi( str )
Char str[];
	{
	unsigned int result;

	(void) sscanf( (char *) str, "%o", &result );
	return result;
	}


/* out - various flavors of outputing a (possibly formatted) string for the
 *	 generated scanner, keeping track of the line count.
 */

void out( str )
const char str[];
	{
	fputs( str, stdout );
	out_line_count( str );
	}

void out_dec( fmt, n )
const char fmt[];
int n;
	{
	printf( fmt, n );
	out_line_count( fmt );
	}

void out_dec2( fmt, n1, n2 )
const char fmt[];
int n1, n2;
	{
	printf( fmt, n1, n2 );
	out_line_count( fmt );
	}

void out_hex( fmt, x )
const char fmt[];
unsigned int x;
	{
	printf( fmt, x );
	out_line_count( fmt );
	}

void out_line_count( str )
const char str[];
	{
	register int i;

	for ( i = 0; str[i]; ++i )
		if ( str[i] == '\n' )
			++out_linenum;
	}

void out_str( fmt, str )
const char fmt[], str[];
	{
	printf( fmt, str );
	out_line_count( fmt );
	out_line_count( str );
	}

void out_str3( fmt, s1, s2, s3 )
const char fmt[], s1[], s2[], s3[];
	{
	printf( fmt, s1, s2, s3 );
	out_line_count( fmt );
	out_line_count( s1 );
	out_line_count( s2 );
	out_line_count( s3 );
	}

void out_str_dec( fmt, str, n )
const char fmt[], str[];
int n;
	{
	printf( fmt, str, n );
	out_line_count( fmt );
	out_line_count( str );
	}

void outc( c )
int c;
	{
	putc( c, stdout );

	if ( c == '\n' )
		++out_linenum;
	}

void outn( str )
const char str[];
	{
	puts( str );
	out_line_count( str );
	++out_linenum;
	}


/* readable_form - return the the human-readable form of a character
 *
 * The returned string is in static storage.
 */

char *readable_form( c )
register int c;
	{
	static char rform[10];

	if ( (c >= 0 && c < 32) || c >= 127 )
		{
		switch ( c )
			{
			case '\b': return "\\b";
			case '\f': return "\\f";
			case '\n': return "\\n";
			case '\r': return "\\r";
			case '\t': return "\\t";

#if __STDC__
			case '\a': return "\\a";
			case '\v': return "\\v";
#endif

			default:
				(void) sprintf( rform, "\\%.3o",
						(unsigned int) c );
				return rform;
			}
		}

	else if ( c == ' ' )
		return "' '";

	else
		{
		rform[0] = c;
		rform[1] = '\0';

		return rform;
		}
	}


/* reallocate_array - increase the size of a dynamic array */

void *reallocate_array( array, size, element_size )
void *array;
int size;
size_t element_size;
	{
	register void *new_array;
	size_t num_bytes = element_size * size;

	new_array = flex_realloc( array, num_bytes );
	if ( ! new_array )
		flexfatal( _( "attempt to increase array size failed" ) );

	return new_array;
	}


/* skelout - write out one section of the skeleton file
 *
 * Description
 *    Copies skelfile or skel array to stdout until a line beginning with
 *    "%%" or EOF is found.
 */
void skelout()
	{
	char buf_storage[MAXLINE];
	char *buf = buf_storage;
	int do_copy = 1;

	/* Loop pulling lines either from the skelfile, if we're using
	 * one, or from the skel[] array.
	 */
	while ( skelfile ?
		(fgets( buf, MAXLINE, skelfile ) != NULL) :
		((buf = (char *) skel[skel_ind++]) != 0) )
		{ /* copy from skel array */
		if ( buf[0] == '%' )
			{ /* control line */
			switch ( buf[1] )
				{
				case '%':
					return;

				case '+':
					do_copy = C_plus_plus;
					break;

				case '-':
					do_copy = ! C_plus_plus;
					break;

				case '*':
					do_copy = 1;
					break;

				default:
					flexfatal(
					_( "bad line in skeleton file" ) );
				}
			}

		else if ( do_copy )
			{
			if ( skelfile )
				/* Skeleton file reads include final
				 * newline, skel[] array does not.
				 */
				out( buf );
			else
				outn( buf );
			}
		}
	}


/* transition_struct_out - output a yy_trans_info structure
 *
 * outputs the yy_trans_info structure with the two elements, element_v and
 * element_n.  Formats the output with spaces and carriage returns.
 */

void transition_struct_out( element_v, element_n )
int element_v, element_n;
	{
	out_dec2( " {%4d,%4d },", element_v, element_n );

	datapos += TRANS_STRUCT_PRINT_LENGTH;

	if ( datapos >= 79 - TRANS_STRUCT_PRINT_LENGTH )
		{
		outc( '\n' );

		if ( ++dataline % 10 == 0 )
			outc( '\n' );

		datapos = 0;
		}
	}


/* The following is only needed when building flex's parser using certain
 * broken versions of bison.
 */
void *yy_flex_xmalloc( size )
int size;
	{
	void *result = flex_alloc( (size_t) size );

	if ( ! result  )
		flexfatal(
			_( "memory allocation failed in yy_flex_xmalloc()" ) );

	return result;
	}


/* zero_out - set a region of memory to 0
 *
 * Sets region_ptr[0] through region_ptr[size_in_bytes - 1] to zero.
 */

void zero_out( region_ptr, size_in_bytes )
char *region_ptr;
size_t size_in_bytes;
	{
	register char *rp, *rp_end;

	rp = region_ptr;
	rp_end = region_ptr + size_in_bytes;

	while ( rp < rp_end )
		*rp++ = 0;
	}