gen.c

flex 词法分析工具 类似于lex 此版本为较早前的版本

		else
			indent_puts( "if ( yyleng >= YYLMAX ) \\" );

		indent_up();
		indent_puts(
		"YY_FATAL_ERROR( \"token too large, exceeds YYLMAX\" ); \\" );
		indent_down();

		if ( yymore_used )
			{
			indent_puts(
"yy_flex_strncpy( &yytext[yy_more_offset], yytext_ptr, yyleng + 1 ); \\" );
			indent_puts( "yyleng += yy_more_offset; \\" );
			indent_puts(
				"yy_prev_more_offset = yy_more_offset; \\" );
			indent_puts( "yy_more_offset = 0; \\" );
			}
		else
			{
			indent_puts(
		"yy_flex_strncpy( yytext, yytext_ptr, yyleng + 1 ); \\" );
			}
		}

	set_indent( 0 );

	skelout();


	out_dec( "#define YY_NUM_RULES %d\n", num_rules );
	out_dec( "#define YY_END_OF_BUFFER %d\n", num_rules + 1 );

	if ( fullspd )
		{
		/* Need to define the transet type as a size large
		 * enough to hold the biggest offset.
		 */
		int total_table_size = tblend + numecs + 1;
		char *trans_offset_type =
			(total_table_size >= MAX_SHORT || long_align) ?
				"long" : "short";

		set_indent( 0 );
		indent_puts( "struct yy_trans_info" );
		indent_up();
		indent_puts( "{" ); 	/* } for vi */

		if ( long_align )
			indent_puts( "long yy_verify;" );
		else
			indent_puts( "short yy_verify;" );

		/* In cases where its sister yy_verify *is* a "yes, there is
		 * a transition", yy_nxt is the offset (in records) to the
		 * next state.  In most cases where there is no transition,
		 * the value of yy_nxt is irrelevant.  If yy_nxt is the -1th
		 * record of a state, though, then yy_nxt is the action number
		 * for that state.
		 */

		indent_put2s( "%s yy_nxt;", trans_offset_type );
		indent_puts( "};" );
		indent_down();
		}

	if ( fullspd )
		genctbl();
	else if ( fulltbl )
		genftbl();
	else
		gentabs();

	/* Definitions for backing up.  We don't need them if REJECT
	 * is being used because then we use an alternative backin-up
	 * technique instead.
	 */
	if ( num_backing_up > 0 && ! reject )
		{
		if ( ! C_plus_plus )
			{
			indent_puts(
			"static yy_state_type yy_last_accepting_state;" );
			indent_puts(
				"static char *yy_last_accepting_cpos;\n" );
			}
		}

	if ( nultrans )
		{
		out_str_dec( C_state_decl, "yy_NUL_trans", lastdfa + 1 );

		for ( i = 1; i <= lastdfa; ++i )
			{
			if ( fullspd )
				out_dec( "    &yy_transition[%d],\n", base[i] );
			else
				mkdata( nultrans[i] );
			}

		dataend();
		}

	if ( ddebug )
		{ /* Spit out table mapping rules to line numbers. */
		if ( ! C_plus_plus )
			{
			indent_puts( "extern int yy_flex_debug;" );
			indent_puts( "int yy_flex_debug = 1;\n" );
			}

		out_str_dec( long_align ? C_long_decl : C_short_decl,
			"yy_rule_linenum", num_rules );
		for ( i = 1; i < num_rules; ++i )
			mkdata( rule_linenum[i] );
		dataend();
		}

	if ( reject )
		{
		/* Declare state buffer variables. */
		if ( ! C_plus_plus )
			{
			outn(
	"static yy_state_type yy_state_buf[YY_BUF_SIZE + 2], *yy_state_ptr;" );
			outn( "static char *yy_full_match;" );
			outn( "static int yy_lp;" );
			}

		if ( variable_trailing_context_rules )
			{
			if ( ! C_plus_plus )
				{
				outn(
				"static int yy_looking_for_trail_begin = 0;" );
				outn( "static int yy_full_lp;" );
				outn( "static int *yy_full_state;" );
				}

			out_hex( "#define YY_TRAILING_MASK 0x%x\n",
				(unsigned int) YY_TRAILING_MASK );
			out_hex( "#define YY_TRAILING_HEAD_MASK 0x%x\n",
				(unsigned int) YY_TRAILING_HEAD_MASK );
			}

		outn( "#define REJECT \\" );
		outn( "{ \\" );		/* } for vi */
		outn(
	"*yy_cp = yy_hold_char; /* undo effects of setting up yytext */ \\" );
		outn(
	"yy_cp = yy_full_match; /* restore poss. backed-over text */ \\" );

		if ( variable_trailing_context_rules )
			{
			outn(
		"yy_lp = yy_full_lp; /* restore orig. accepting pos. */ \\" );
			outn(
		"yy_state_ptr = yy_full_state; /* restore orig. state */ \\" );
			outn(
	"yy_current_state = *yy_state_ptr; /* restore curr. state */ \\" );
			}

		outn( "++yy_lp; \\" );
		outn( "goto find_rule; \\" );
		/* { for vi */
		outn( "}" );
		}

	else
		{
		outn(
		"/* The intent behind this definition is that it'll catch" );
		outn( " * any uses of REJECT which flex missed." );
		outn( " */" );
		outn( "#define REJECT reject_used_but_not_detected" );
		}

	if ( yymore_used )
		{
		if ( ! C_plus_plus )
			{
			if ( yytext_is_array )
				{
				indent_puts( "static int yy_more_offset = 0;" );
				indent_puts(
					"static int yy_prev_more_offset = 0;" );
				}
			else
				{
				indent_puts( "static int yy_more_flag = 0;" );
				indent_puts( "static int yy_more_len = 0;" );
				}
			}

		if ( yytext_is_array )
			{
			indent_puts(
	"#define yymore() (yy_more_offset = yy_flex_strlen( yytext ))" );
			indent_puts( "#define YY_NEED_STRLEN" );
			indent_puts( "#define YY_MORE_ADJ 0" );
			indent_puts( "#define YY_RESTORE_YY_MORE_OFFSET \\" );
			indent_up();
			indent_puts( "{ \\" );
			indent_puts( "yy_more_offset = yy_prev_more_offset; \\" );
			indent_puts( "yyleng -= yy_more_offset; \\" );
			indent_puts( "}" );
			indent_down();
			}
		else
			{
			indent_puts( "#define yymore() (yy_more_flag = 1)" );
			indent_puts( "#define YY_MORE_ADJ yy_more_len" );
			indent_puts( "#define YY_RESTORE_YY_MORE_OFFSET" );
			}
		}

	else
		{
		indent_puts( "#define yymore() yymore_used_but_not_detected" );
		indent_puts( "#define YY_MORE_ADJ 0" );
		indent_puts( "#define YY_RESTORE_YY_MORE_OFFSET" );
		}

	if ( ! C_plus_plus )
		{
		if ( yytext_is_array )
			{
			outn( "#ifndef YYLMAX" );
			outn( "#define YYLMAX 8192" );
			outn( "#endif\n" );
			outn( "char yytext[YYLMAX];" );
			outn( "char *yytext_ptr;" );
			}

		else
			outn( "char *yytext;" );
		}

	out( &action_array[defs1_offset] );

	line_directive_out( stdout, 0 );

	skelout();

	if ( ! C_plus_plus )
		{
		if ( use_read )
			{
			outn(
"\tif ( (result = read( fileno(yyin), (char *) buf, max_size )) < 0 ) \\" );
			outn(
		"\t\tYY_FATAL_ERROR( \"input in flex scanner failed\" );" );
			}

		else
			{
			outn(
			"\tif ( yy_current_buffer->yy_is_interactive ) \\" );
			outn( "\t\t{ \\" );
			outn( "\t\tint c = '*', n; \\" );
			outn( "\t\tfor ( n = 0; n < max_size && \\" );
	outn( "\t\t\t     (c = getc( yyin )) != EOF && c != '\\n'; ++n ) \\" );
			outn( "\t\t\tbuf[n] = (char) c; \\" );
			outn( "\t\tif ( c == '\\n' ) \\" );
			outn( "\t\t\tbuf[n++] = (char) c; \\" );
			outn( "\t\tif ( c == EOF && ferror( yyin ) ) \\" );
			outn(
	"\t\t\tYY_FATAL_ERROR( \"input in flex scanner failed\" ); \\" );
			outn( "\t\tresult = n; \\" );
			outn( "\t\t} \\" );
			outn(
	"\telse if ( ((result = fread( buf, 1, max_size, yyin )) == 0) \\" );
			outn( "\t\t  && ferror( yyin ) ) \\" );
			outn(
		"\t\tYY_FATAL_ERROR( \"input in flex scanner failed\" );" );
			}
		}

	skelout();

	indent_puts( "#define YY_RULE_SETUP \\" );
	indent_up();
	if ( bol_needed )
		{
		indent_puts( "if ( yyleng > 0 ) \\" );
		indent_up();
		indent_puts( "yy_current_buffer->yy_at_bol = \\" );
		indent_puts( "\t\t(yytext[yyleng - 1] == '\\n'); \\" );
		indent_down();
		}
	indent_puts( "YY_USER_ACTION" );
	indent_down();

	skelout();

	/* Copy prolog to output file. */
	out( &action_array[prolog_offset] );

	line_directive_out( stdout, 0 );

	skelout();

	set_indent( 2 );

	if ( yymore_used && ! yytext_is_array )
		{
		indent_puts( "yy_more_len = 0;" );
		indent_puts( "if ( yy_more_flag )" );
		indent_up();
		indent_puts( "{" );
		indent_puts( "yy_more_len = yy_c_buf_p - yytext_ptr;" );
		indent_puts( "yy_more_flag = 0;" );
		indent_puts( "}" );
		indent_down();
		}

	skelout();

	gen_start_state();

	/* Note, don't use any indentation. */
	outn( "yy_match:" );
	gen_next_match();

	skelout();
	set_indent( 2 );
	gen_find_action();

	skelout();
	if ( do_yylineno )
		{
		indent_puts( "if ( yy_act != YY_END_OF_BUFFER )" );
		indent_up();
		indent_puts( "{" );
		indent_puts( "int yyl;" );
		indent_puts( "for ( yyl = 0; yyl < yyleng; ++yyl )" );
		indent_up();
		indent_puts( "if ( yytext[yyl] == '\\n' )" );
		indent_up();
		indent_puts( "++yylineno;" );
		indent_down();
		indent_down();
		indent_puts( "}" );
		indent_down();
		}

	skelout();
	if ( ddebug )
		{
		indent_puts( "if ( yy_flex_debug )" );
		indent_up();

		indent_puts( "{" );
		indent_puts( "if ( yy_act == 0 )" );
		indent_up();
		indent_puts( C_plus_plus ?
			"cerr << \"--scanner backing up\\n\";" :
			"fprintf( stderr, \"--scanner backing up\\n\" );" );
		indent_down();

		do_indent();
		out_dec( "else if ( yy_act < %d )\n", num_rules );
		indent_up();

		if ( C_plus_plus )
			{
			indent_puts(
	"cerr << \"--accepting rule at line \" << yy_rule_linenum[yy_act] <<" );
			indent_puts(
			"         \"(\\\"\" << yytext << \"\\\")\\n\";" );
			}
		else
			{
			indent_puts(
	"fprintf( stderr, \"--accepting rule at line %d (\\\"%s\\\")\\n\"," );

			indent_puts(
				"         yy_rule_linenum[yy_act], yytext );" );
			}

		indent_down();

		do_indent();
		out_dec( "else if ( yy_act == %d )\n", num_rules );
		indent_up();

		if ( C_plus_plus )
			{
			indent_puts(
"cerr << \"--accepting default rule (\\\"\" << yytext << \"\\\")\\n\";" );
			}
		else
			{
			indent_puts(
	"fprintf( stderr, \"--accepting default rule (\\\"%s\\\")\\n\"," );
			indent_puts( "         yytext );" );
			}

		indent_down();

		do_indent();
		out_dec( "else if ( yy_act == %d )\n", num_rules + 1 );
		indent_up();

		indent_puts( C_plus_plus ?
			"cerr << \"--(end of buffer or a NUL)\\n\";" :
		"fprintf( stderr, \"--(end of buffer or a NUL)\\n\" );" );

		indent_down();

		do_indent();
		outn( "else" );
		indent_up();

		if ( C_plus_plus )
			{
			indent_puts(
	"cerr << \"--EOF (start condition \" << YY_START << \")\\n\";" );
			}
		else
			{
			indent_puts(
	"fprintf( stderr, \"--EOF (start condition %d)\\n\", YY_START );" );
			}

		indent_down();

		indent_puts( "}" );
		indent_down();
		}

	/* Copy actions to output file. */
	skelout();
	indent_up();
	gen_bu_action();
	out( &action_array[action_offset] );

	line_directive_out( stdout, 0 );

	/* generate cases for any missing EOF rules */
	for ( i = 1; i <= lastsc; ++i )
		if ( ! sceof[i] )
			{
			do_indent();
			out_str( "case YY_STATE_EOF(%s):\n", scname[i] );
			did_eof_rule = true;
			}

	if ( did_eof_rule )
		{
		indent_up();
		indent_puts( "yyterminate();" );
		indent_down();
		}


	/* Generate code for handling NUL's, if needed. */

	/* First, deal with backing up and setting up yy_cp if the scanner
	 * finds that it should JAM on the NUL.
	 */
	skelout();
	set_indent( 4 );

	if ( fullspd || fulltbl )
		indent_puts( "yy_cp = yy_c_buf_p;" );

	else
		{ /* compressed table */
		if ( ! reject && ! interactive )
			{
			/* Do the guaranteed-needed backing up to figure
			 * out the match.
			 */
			indent_puts( "yy_cp = yy_last_accepting_cpos;" );
			indent_puts(
				"yy_current_state = yy_last_accepting_state;" );
			}

		else
			/* Still need to initialize yy_cp, though
			 * yy_current_state was set up by
			 * yy_get_previous_state().
			 */
			indent_puts( "yy_cp = yy_c_buf_p;" );
		}


	/* Generate code for yy_get_previous_state(). */
	set_indent( 1 );
	skelout();

	gen_start_state();

	set_indent( 2 );
	skelout();
	gen_next_state( true );

	set_indent( 1 );
	skelout();
	gen_NUL_trans();

	skelout();
	if ( do_yylineno )
		{ /* update yylineno inside of unput() */
		indent_puts( "if ( c == '\\n' )" );
		indent_up();
		indent_puts( "--yylineno;" );
		indent_down();
		}

	skelout();
	/* Update BOL and yylineno inside of input(). */
	if ( bol_needed )
		{
		indent_puts( "yy_current_buffer->yy_at_bol = (c == '\\n');" );
		if ( do_yylineno )
			{
			indent_puts( "if ( yy_current_buffer->yy_at_bol )" );
			indent_up();
			indent_puts( "++yylineno;" );
			indent_down();
			}
		}

	else if ( do_yylineno )
		{
		indent_puts( "if ( c == '\\n' )" );
		indent_up();
		indent_puts( "++yylineno;" );
		indent_down();
		}

	skelout();

	/* Copy remainder of input to output. */

	line_directive_out( stdout, 1 );

	if ( sectnum == 3 )
		(void) flexscan(); /* copy remainder of input to output */
	}