flex.skl

flex编译器的源代码

do_action:	/* This label is used only to access EOF actions. */

%% debug code goes here

		switch ( yy_act )
	{ /* beginning of action switch */
%% actions go here

	case YY_END_OF_BUFFER:
		{
		/* Amount of text matched not including the EOB char. */
		int yy_amount_of_matched_text = (int) (yy_cp - yytext_ptr) - 1;

		/* Undo the effects of YY_DO_BEFORE_ACTION. */
		*yy_cp = yy_hold_char;

		if ( yy_current_buffer->yy_buffer_status == YY_BUFFER_NEW )
			{
			/* We're scanning a new file or input source.  It's
			 * possible that this happened because the user
			 * just pointed yyin at a new source and called
			 * yylex().  If so, then we have to assure
			 * consistency between yy_current_buffer and our
			 * globals.  Here is the right place to do so, because
			 * this is the first action (other than possibly a
			 * back-up) that will match for the new input source.
			 */
			yy_n_chars = yy_current_buffer->yy_n_chars;
			yy_current_buffer->yy_input_file = yyin;
			yy_current_buffer->yy_buffer_status = YY_BUFFER_NORMAL;
			}

		/* Note that here we test for yy_c_buf_p "<=" to the position
		 * of the first EOB in the buffer, since yy_c_buf_p will
		 * already have been incremented past the NUL character
		 * (since all states make transitions on EOB to the
		 * end-of-buffer state).  Contrast this with the test
		 * in input().
		 */
		if ( yy_c_buf_p <= &yy_current_buffer->yy_ch_buf[yy_n_chars] )
			{ /* This was really a NUL. */
			yy_state_type yy_next_state;

			yy_c_buf_p = yytext_ptr + yy_amount_of_matched_text;

			yy_current_state = yy_get_previous_state();

			/* Okay, we're now positioned to make the NUL
			 * transition.  We couldn't have
			 * yy_get_previous_state() go ahead and do it
			 * for us because it doesn't know how to deal
			 * with the possibility of jamming (and we don't
			 * want to build jamming into it because then it
			 * will run more slowly).
			 */

			yy_next_state = yy_try_NUL_trans( yy_current_state );

			yy_bp = yytext_ptr + YY_MORE_ADJ;

			if ( yy_next_state )
				{
				/* Consume the NUL. */
				yy_cp = ++yy_c_buf_p;
				yy_current_state = yy_next_state;
				goto yy_match;
				}

			else
				{
%% code to do back-up for compressed tables and set up yy_cp goes here
				goto yy_find_action;
				}
			}

		else switch ( yy_get_next_buffer() )
			{
			case EOB_ACT_END_OF_FILE:
				{
				yy_did_buffer_switch_on_eof = 0;

				if ( yywrap() )
					{
					/* Note: because we've taken care in
					 * yy_get_next_buffer() to have set up
					 * yytext, we can now set up
					 * yy_c_buf_p so that if some total
					 * hoser (like flex itself) wants to
					 * call the scanner after we return the
					 * YY_NULL, it'll still work - another
					 * YY_NULL will get returned.
					 */
					yy_c_buf_p = yytext_ptr + YY_MORE_ADJ;

					yy_act = YY_STATE_EOF(YY_START);
					goto do_action;
					}

				else
					{
					if ( ! yy_did_buffer_switch_on_eof )
						YY_NEW_FILE;
					}
				break;
				}

			case EOB_ACT_CONTINUE_SCAN:
				yy_c_buf_p =
					yytext_ptr + yy_amount_of_matched_text;

				yy_current_state = yy_get_previous_state();

				yy_cp = yy_c_buf_p;
				yy_bp = yytext_ptr + YY_MORE_ADJ;
				goto yy_match;

			case EOB_ACT_LAST_MATCH:
				yy_c_buf_p =
				&yy_current_buffer->yy_ch_buf[yy_n_chars];

				yy_current_state = yy_get_previous_state();

				yy_cp = yy_c_buf_p;
				yy_bp = yytext_ptr + YY_MORE_ADJ;
				goto yy_find_action;
			}
		break;
		}

	default:
		YY_FATAL_ERROR(
			"fatal flex scanner internal error--no action found" );
	} /* end of action switch */
		} /* end of scanning one token */
	} /* end of yylex */

%+
yyFlexLexer::yyFlexLexer( istream* arg_yyin, ostream* arg_yyout )
	{
	yyin = arg_yyin;
	yyout = arg_yyout;
	yy_c_buf_p = 0;
	yy_init = 1;
	yy_start = 0;
	yy_flex_debug = 0;
	yylineno = 1;	// this will only get updated if %option yylineno

	yy_did_buffer_switch_on_eof = 0;

	yy_looking_for_trail_begin = 0;
	yy_more_flag = 0;
	yy_more_len = 0;

	yy_start_stack_ptr = yy_start_stack_depth = 0;
	yy_start_stack = 0;

	yy_current_buffer = 0;

#ifdef YY_USES_REJECT
	yy_state_buf = new yy_state_type[YY_BUF_SIZE + 2];
#else
	yy_state_buf = 0;
#endif
	}

yyFlexLexer::~yyFlexLexer()
	{
	delete yy_state_buf;
	yy_delete_buffer( yy_current_buffer );
	}

void yyFlexLexer::switch_streams( istream* new_in, ostream* new_out )
	{
	if ( new_in )
		{
		yy_delete_buffer( yy_current_buffer );
		yy_switch_to_buffer( yy_create_buffer( new_in, YY_BUF_SIZE ) );
		}

	if ( new_out )
		yyout = new_out;
	}

#ifdef YY_INTERACTIVE
int yyFlexLexer::LexerInput( char* buf, int /* max_size */ )
#else
int yyFlexLexer::LexerInput( char* buf, int max_size )
#endif
	{
	if ( yyin->eof() || yyin->fail() )
		return 0;

#ifdef YY_INTERACTIVE
	yyin->get( buf[0] );

	if ( yyin->eof() )
		return 0;

	if ( yyin->bad() )
		return -1;

	return 1;

#else
	(void) yyin->read( buf, max_size );

	if ( yyin->bad() )
		return -1;
	else
		return yyin->gcount();
#endif
	}

void yyFlexLexer::LexerOutput( const char* buf, int size )
	{
	(void) yyout->write( buf, size );
	}
%*

/* yy_get_next_buffer - try to read in a new buffer
 *
 * Returns a code representing an action:
 *	EOB_ACT_LAST_MATCH -
 *	EOB_ACT_CONTINUE_SCAN - continue scanning from current position
 *	EOB_ACT_END_OF_FILE - end of file
 */

%-
static int yy_get_next_buffer()
%+
int yyFlexLexer::yy_get_next_buffer()
%*
	{
	register char *dest = yy_current_buffer->yy_ch_buf;
	register char *source = yytext_ptr;
	register int number_to_move, i;
	int ret_val;

	if ( yy_c_buf_p > &yy_current_buffer->yy_ch_buf[yy_n_chars + 1] )
		YY_FATAL_ERROR(
		"fatal flex scanner internal error--end of buffer missed" );

	if ( yy_current_buffer->yy_fill_buffer == 0 )
		{ /* Don't try to fill the buffer, so this is an EOF. */
		if ( yy_c_buf_p - yytext_ptr - YY_MORE_ADJ == 1 )
			{
			/* We matched a singled characater, the EOB, so
			 * treat this as a final EOF.
			 */
			return EOB_ACT_END_OF_FILE;
			}

		else
			{
			/* We matched some text prior to the EOB, first
			 * process it.
			 */
			return EOB_ACT_LAST_MATCH;
			}
		}

	/* Try to read more data. */

	/* First move last chars to start of buffer. */
	number_to_move = (int) (yy_c_buf_p - yytext_ptr) - 1;

	for ( i = 0; i < number_to_move; ++i )
		*(dest++) = *(source++);

	if ( yy_current_buffer->yy_buffer_status == YY_BUFFER_EOF_PENDING )
		/* don't do the read, it's not guaranteed to return an EOF,
		 * just force an EOF
		 */
		yy_n_chars = 0;

	else
		{
		int num_to_read =
			yy_current_buffer->yy_buf_size - number_to_move - 1;

		while ( num_to_read <= 0 )
			{ /* Not enough room in the buffer - grow it. */
#ifdef YY_USES_REJECT
			YY_FATAL_ERROR(
"input buffer overflow, can't enlarge buffer because scanner uses REJECT" );
#else

			/* just a shorter name for the current buffer */
			YY_BUFFER_STATE b = yy_current_buffer;

			int yy_c_buf_p_offset =
				(int) (yy_c_buf_p - b->yy_ch_buf);

			if ( b->yy_is_our_buffer )
				{
				int new_size = b->yy_buf_size * 2;

				if ( new_size <= 0 )
					b->yy_buf_size += b->yy_buf_size / 8;
				else
					b->yy_buf_size *= 2;

				b->yy_ch_buf = (char *)
					/* Include room in for 2 EOB chars. */
					yy_flex_realloc( (void *) b->yy_ch_buf,
							 b->yy_buf_size + 2 );
				}
			else
				/* Can't grow it, we don't own it. */
				b->yy_ch_buf = 0;

			if ( ! b->yy_ch_buf )
				YY_FATAL_ERROR(
				"fatal error - scanner input buffer overflow" );

			yy_c_buf_p = &b->yy_ch_buf[yy_c_buf_p_offset];

			num_to_read = yy_current_buffer->yy_buf_size -
						number_to_move - 1;
#endif
			}

		if ( num_to_read > YY_READ_BUF_SIZE )
			num_to_read = YY_READ_BUF_SIZE;

		/* Read in more data. */
		YY_INPUT( (&yy_current_buffer->yy_ch_buf[number_to_move]),
			yy_n_chars, num_to_read );
		}

	if ( yy_n_chars == 0 )
		{
		if ( number_to_move == YY_MORE_ADJ )
			{
			ret_val = EOB_ACT_END_OF_FILE;
			yyrestart( yyin );
			}

		else
			{
			ret_val = EOB_ACT_LAST_MATCH;
			yy_current_buffer->yy_buffer_status =
				YY_BUFFER_EOF_PENDING;
			}
		}

	else
		ret_val = EOB_ACT_CONTINUE_SCAN;

	yy_n_chars += number_to_move;
	yy_current_buffer->yy_ch_buf[yy_n_chars] = YY_END_OF_BUFFER_CHAR;
	yy_current_buffer->yy_ch_buf[yy_n_chars + 1] = YY_END_OF_BUFFER_CHAR;

	yytext_ptr = &yy_current_buffer->yy_ch_buf[0];

	return ret_val;
	}


/* yy_get_previous_state - get the state just before the EOB char was reached */

%-
static yy_state_type yy_get_previous_state()
%+
yy_state_type yyFlexLexer::yy_get_previous_state()
%*
	{
	register yy_state_type yy_current_state;
	register char *yy_cp;

%% code to get the start state into yy_current_state goes here

	for ( yy_cp = yytext_ptr + YY_MORE_ADJ; yy_cp < yy_c_buf_p; ++yy_cp )
		{
%% code to find the next state goes here
		}

	return yy_current_state;
	}


/* yy_try_NUL_trans - try to make a transition on the NUL character
 *
 * synopsis
 *	next_state = yy_try_NUL_trans( current_state );
 */

%-
#ifdef YY_USE_PROTOS
static yy_state_type yy_try_NUL_trans( yy_state_type yy_current_state )
#else
static yy_state_type yy_try_NUL_trans( yy_current_state )
yy_state_type yy_current_state;
#endif
%+
yy_state_type yyFlexLexer::yy_try_NUL_trans( yy_state_type yy_current_state )
%*
	{
	register int yy_is_jam;
%% code to find the next state, and perhaps do backing up, goes here

	return yy_is_jam ? 0 : yy_current_state;
	}


%-
#ifndef YY_NO_UNPUT
#ifdef YY_USE_PROTOS
static void yyunput( int c, register char *yy_bp )
#else
static void yyunput( c, yy_bp )
int c;
register char *yy_bp;
#endif
%+
void yyFlexLexer::yyunput( int c, register char* yy_bp )
%*
	{
	register char *yy_cp = yy_c_buf_p;

	/* undo effects of setting up yytext */
	*yy_cp = yy_hold_char;

	if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 )
		{ /* need to shift things up to make room */
		/* +2 for EOB chars. */
		register int number_to_move = yy_n_chars + 2;
		register char *dest = &yy_current_buffer->yy_ch_buf[
					yy_current_buffer->yy_buf_size + 2];
		register char *source =
				&yy_current_buffer->yy_ch_buf[number_to_move];

		while ( source > yy_current_buffer->yy_ch_buf )
			*--dest = *--source;

		yy_cp += (int) (dest - source);
		yy_bp += (int) (dest - source);
		yy_n_chars = yy_current_buffer->yy_buf_size;

		if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 )
			YY_FATAL_ERROR( "flex scanner push-back overflow" );
		}

	*--yy_cp = (char) c;

%% update yylineno here

	yytext_ptr = yy_bp;
	yy_hold_char = *yy_cp;
	yy_c_buf_p = yy_cp;
	}
%-
#endif	/* ifndef YY_NO_UNPUT */
%*


%-
#ifdef __cplusplus
static int yyinput()
#else
static int input()
#endif
%+
int yyFlexLexer::yyinput()
%*
	{
	int c;

	*yy_c_buf_p = yy_hold_char;

	if ( *yy_c_buf_p == YY_END_OF_BUFFER_CHAR )
		{
		/* yy_c_buf_p now points to the character we want to return.
		 * If this occurs *before* the EOB characters, then it's a
		 * valid NUL; if not, then we've hit the end of the buffer.
		 */
		if ( yy_c_buf_p < &yy_current_buffer->yy_ch_buf[yy_n_chars] )
			/* This was really a NUL. */
			*yy_c_buf_p = '\0';

		else
			{ /* need more input */
			yytext_ptr = yy_c_buf_p;
			++yy_c_buf_p;

			switch ( yy_get_next_buffer() )
				{
				case EOB_ACT_END_OF_FILE:
					{
					if ( yywrap() )
						{
						yy_c_buf_p =
						yytext_ptr + YY_MORE_ADJ;
						return EOF;
						}

					if ( ! yy_did_buffer_switch_on_eof )
						YY_NEW_FILE;
#ifdef __cplusplus
					return yyinput();
#else
					return input();
#endif