parse.c

flex编译器的源代码

void format_pinpoint_message( msg, arg )
char msg[], arg[];
	{
	char errmsg[MAXLINE];

	(void) sprintf( errmsg, msg, arg );
	pinpoint_message( errmsg );
	}


/* pinpoint_message - write out a message, pinpointing its location */

void pinpoint_message( str )
char str[];
	{
	line_pinpoint( str, linenum );
	}


/* line_warning - report a warning at a given line, unless -w was given */

void line_warning( str, line )
char str[];
int line;
	{
	char warning[MAXLINE];

	if ( ! nowarn )
		{
		sprintf( warning, "warning, %s", str );
		line_pinpoint( warning, line );
		}
	}


/* line_pinpoint - write out a message, pinpointing it at the given line */

void line_pinpoint( str, line )
char str[];
int line;
	{
	fprintf( stderr, "\"%s\", line %d: %s\n", infilename, line, str );
	}


/* yyerror - eat up an error message from the parser;
 *	     currently, messages are ignore
 */

void yyerror( msg )
char msg[];
	{
	}
#line 541 "y.tab.c"
#define YYABORT goto yyabort
#define YYREJECT goto yyabort
#define YYACCEPT goto yyaccept
#define YYERROR goto yyerrlab
int
yyparse()
{
    register int yym, yyn, yystate;
#if YYDEBUG
    register char *yys;
    extern char *getenv();

    if (yys = getenv("YYDEBUG"))
    {
        yyn = *yys;
        if (yyn >= '0' && yyn <= '9')
            yydebug = yyn - '0';
    }
#endif

    yynerrs = 0;
    yyerrflag = 0;
    yychar = (-1);

    yyssp = yyss;
    yyvsp = yyvs;
    *yyssp = yystate = 0;

yyloop:
    if (yyn = yydefred[yystate]) goto yyreduce;
    if (yychar < 0)
    {
        if ((yychar = yylex()) < 0) yychar = 0;
#if YYDEBUG
        if (yydebug)
        {
            yys = 0;
            if (yychar <= YYMAXTOKEN) yys = yyname[yychar];
            if (!yys) yys = "illegal-symbol";
            printf("%sdebug: state %d, reading %d (%s)\n",
                    YYPREFIX, yystate, yychar, yys);
        }
#endif
    }
    if ((yyn = yysindex[yystate]) && (yyn += yychar) >= 0 &&
            yyn <= YYTABLESIZE && yycheck[yyn] == yychar)
    {
#if YYDEBUG
        if (yydebug)
            printf("%sdebug: state %d, shifting to state %d\n",
                    YYPREFIX, yystate, yytable[yyn]);
#endif
        if (yyssp >= yyss + yystacksize - 1)
        {
            goto yyoverflow;
        }
        *++yyssp = yystate = yytable[yyn];
        *++yyvsp = yylval;
        yychar = (-1);
        if (yyerrflag > 0)  --yyerrflag;
        goto yyloop;
    }
    if ((yyn = yyrindex[yystate]) && (yyn += yychar) >= 0 &&
            yyn <= YYTABLESIZE && yycheck[yyn] == yychar)
    {
        yyn = yytable[yyn];
        goto yyreduce;
    }
    if (yyerrflag) goto yyinrecovery;
#ifdef lint
    goto yynewerror;
#endif
yynewerror:
    yyerror("syntax error");
#ifdef lint
    goto yyerrlab;
#endif
yyerrlab:
    ++yynerrs;
yyinrecovery:
    if (yyerrflag < 3)
    {
        yyerrflag = 3;
        for (;;)
        {
            if ((yyn = yysindex[*yyssp]) && (yyn += YYERRCODE) >= 0 &&
                    yyn <= YYTABLESIZE && yycheck[yyn] == YYERRCODE)
            {
#if YYDEBUG
                if (yydebug)
                    printf("%sdebug: state %d, error recovery shifting\
 to state %d\n", YYPREFIX, *yyssp, yytable[yyn]);
#endif
                if (yyssp >= yyss + yystacksize - 1)
                {
                    goto yyoverflow;
                }
                *++yyssp = yystate = yytable[yyn];
                *++yyvsp = yylval;
                goto yyloop;
            }
            else
            {
#if YYDEBUG
                if (yydebug)
                    printf("%sdebug: error recovery discarding state %d\n",
                            YYPREFIX, *yyssp);
#endif
                if (yyssp <= yyss) goto yyabort;
                --yyssp;
                --yyvsp;
            }
        }
    }
    else
    {
        if (yychar == 0) goto yyabort;
#if YYDEBUG
        if (yydebug)
        {
            yys = 0;
            if (yychar <= YYMAXTOKEN) yys = yyname[yychar];
            if (!yys) yys = "illegal-symbol";
            printf("%sdebug: state %d, error recovery discards token %d (%s)\n",
                    YYPREFIX, yystate, yychar, yys);
        }
#endif
        yychar = (-1);
        goto yyloop;
    }
yyreduce:
#if YYDEBUG
    if (yydebug)
        printf("%sdebug: state %d, reducing by rule %d (%s)\n",
                YYPREFIX, yystate, yyn, yyrule[yyn]);
#endif
    yym = yylen[yyn];
    yyval = yyvsp[1-yym];
    switch (yyn)
    {
case 1:
#line 113 "./parse.y"
{ /* add default rule */
			int def_rule;

			pat = cclinit();
			cclnegate( pat );

			def_rule = mkstate( -pat );

			/* Remember the number of the default rule so we
			 * don't generate "can't match" warnings for it.
			 */
			default_rule = num_rules;

			finish_rule( def_rule, false, 0, 0 );

			for ( i = 1; i <= lastsc; ++i )
				scset[i] = mkbranch( scset[i], def_rule );

			if ( spprdflt )
				add_action(
				"YY_FATAL_ERROR( \"flex scanner jammed\" )" );
			else
				add_action( "ECHO" );

			add_action( ";\n\tYY_BREAK\n" );
			}
break;
case 2:
#line 142 "./parse.y"
{ /* initialize for processing rules */

			/* Create default DFA start condition. */
			scinstal( "INITIAL", false );
			}
break;
case 6:
#line 153 "./parse.y"
{ synerr( "unknown error processing section 1" ); }
break;
case 7:
#line 157 "./parse.y"
{
			check_options();
			scon_stk = allocate_integer_array( lastsc + 1 );
			scon_stk_ptr = 0;
			}
break;
case 8:
#line 165 "./parse.y"
{ xcluflg = false; }
break;
case 9:
#line 168 "./parse.y"
{ xcluflg = true; }
break;
case 10:
#line 172 "./parse.y"
{ scinstal( nmstr, xcluflg ); }
break;
case 11:
#line 175 "./parse.y"
{ scinstal( nmstr, xcluflg ); }
break;
case 12:
#line 178 "./parse.y"
{ synerr( "bad start condition list" ); }
break;
case 16:
#line 189 "./parse.y"
{
			outfilename = copy_string( nmstr );
			did_outfilename = 1;
			}
break;
case 17:
#line 194 "./parse.y"
{ prefix = copy_string( nmstr ); }
break;
case 18:
#line 196 "./parse.y"
{ yyclass = copy_string( nmstr ); }
break;
case 19:
#line 200 "./parse.y"
{ scon_stk_ptr = yyvsp[-3]; }
break;
case 20:
#line 202 "./parse.y"
{ scon_stk_ptr = yyvsp[-3]; }
break;
case 22:
#line 207 "./parse.y"
{
			/* Initialize for a parse of one rule. */
			trlcontxt = variable_trail_rule = varlength = false;
			trailcnt = headcnt = rulelen = 0;
			current_state_type = STATE_NORMAL;
			previous_continued_action = continued_action;
			in_rule = true;

			new_rule();
			}
break;
case 23:
#line 220 "./parse.y"
{
			pat = yyvsp[0];
			finish_rule( pat, variable_trail_rule,
				headcnt, trailcnt );

			if ( scon_stk_ptr > 0 )
				{
				for ( i = 1; i <= scon_stk_ptr; ++i )
					scbol[scon_stk[i]] =
						mkbranch( scbol[scon_stk[i]],
								pat );
				}

			else
				{
				/* Add to all non-exclusive start conditions,
				 * including the default (0) start condition.
				 */

				for ( i = 1; i <= lastsc; ++i )
					if ( ! scxclu[i] )
						scbol[i] = mkbranch( scbol[i],
									pat );
				}

			if ( ! bol_needed )
				{
				bol_needed = true;

				if ( performance_report > 1 )
					pinpoint_message(
			"'^' operator results in sub-optimal performance" );
				}
			}
break;
case 24:
#line 256 "./parse.y"
{
			pat = yyvsp[0];
			finish_rule( pat, variable_trail_rule,
				headcnt, trailcnt );

			if ( scon_stk_ptr > 0 )
				{
				for ( i = 1; i <= scon_stk_ptr; ++i )
					scset[scon_stk[i]] =
						mkbranch( scset[scon_stk[i]],
								pat );
				}

			else
				{
				for ( i = 1; i <= lastsc; ++i )
					if ( ! scxclu[i] )
						scset[i] =
							mkbranch( scset[i],
								pat );
				}
			}
break;
case 25:
#line 280 "./parse.y"
{
			if ( scon_stk_ptr > 0 )
				build_eof_action();
	
			else
				{
				/* This EOF applies to all start conditions
				 * which don't already have EOF actions.
				 */
				for ( i = 1; i <= lastsc; ++i )
					if ( ! sceof[i] )
						scon_stk[++scon_stk_ptr] = i;

				if ( scon_stk_ptr == 0 )
					warn(
			"all start conditions already have <<EOF>> rules" );

				else
					build_eof_action();
				}
			}
break;
case 26:
#line 303 "./parse.y"
{ synerr( "unrecognized rule" ); }
break;
case 27:
#line 307 "./parse.y"
{ yyval = scon_stk_ptr; }
break;
case 28:
#line 311 "./parse.y"
{ yyval = yyvsp[-2]; }
break;
case 29:
#line 314 "./parse.y"
{
			yyval = scon_stk_ptr;

			for ( i = 1; i <= lastsc; ++i )
				{
				int j;

				for ( j = 1; j <= scon_stk_ptr; ++j )
					if ( scon_stk[j] == i )
						break;

				if ( j > scon_stk_ptr )
					scon_stk[++scon_stk_ptr] = i;
				}
			}
break;
case 30:
#line 331 "./parse.y"
{ yyval = scon_stk_ptr; }
break;
case 33:
#line 339 "./parse.y"
{ synerr( "bad start condition list" ); }
break;
case 34:
#line 343 "./parse.y"
{
			if ( (scnum = sclookup( nmstr )) == 0 )
				format_pinpoint_message(
					"undeclared start condition %s",
					nmstr );
			else
				{
				for ( i = 1; i <= scon_stk_ptr; ++i )
					if ( scon_stk[i] == scnum )
						{
						format_warn(
							"<%s> specified twice",
							scname[scnum] );
						break;
						}

				if ( i > scon_stk_ptr )
					scon_stk[++scon_stk_ptr] = scnum;
				}
			}
break;
case 35:
#line 366 "./parse.y"
{
			if ( transchar[lastst[yyvsp[0]]] != SYM_EPSILON )
				/* Provide final transition \now/ so it
				 * will be marked as a trailing context
				 * state.
				 */
				yyvsp[0] = link_machines( yyvsp[0],
						mkstate( SYM_EPSILON ) );

			mark_beginning_as_normal( yyvsp[0] );
			current_state_type = STATE_NORMAL;

			if ( previous_continued_action )
				{
				/* We need to treat this as variable trailing
				 * context so that the backup does not happen
				 * in the action but before the action switch
				 * statement.  If the backup happens in the
				 * action, then the rules "falling into" this
				 * one's action will *also* do the backup,
				 * erroneously.
				 */
				if ( ! varlength || headcnt != 0 )
					warn(
		"trailing context made variable due to preceding '|' action" );

				/* Mark as variable. */
				varlength = true;
				headcnt = 0;
				}

			if ( lex_compat || (varlength && headcnt == 0) )
				{ /* variable trailing context rule */
				/* Mark the first part of the rule as the
				 * accepting "head" part of a trailing
				 * context rule.