parse.c

C++版 词法分析、语法分析器

  else
    {
      yychar1 = YYTRANSLATE(YY_parse_CHAR);

#if YY_parse_DEBUG != 0
      if (YY_parse_DEBUG_FLAG)
	{
	  fprintf (stderr, "Next token is %d (%s", YY_parse_CHAR, yytname[yychar1]);
	  /* Give the individual parser a way to print the precise meaning
	     of a token, for further debugging info.  */
#ifdef YYPRINT
	  YYPRINT (stderr, YY_parse_CHAR, YY_parse_LVAL);
#endif
	  fprintf (stderr, ")\n");
	}
#endif
    }

  yyn += yychar1;
  if (yyn < 0 || yyn > YYLAST || yycheck[yyn] != yychar1)
    YYGOTO(yydefault);

  yyn = yytable[yyn];

  /* yyn is what to do for this token type in this state.
     Negative => reduce, -yyn is rule number.
     Positive => shift, yyn is new state.
       New state is final state => don't bother to shift,
       just return success.
     0, or most negative number => error.  */

  if (yyn < 0)
    {
      if (yyn == YYFLAG)
	YYGOTO(yyerrlab);
      yyn = -yyn;
      YYGOTO(yyreduce);
    }
  else if (yyn == 0)
    YYGOTO(yyerrlab);

  if (yyn == YYFINAL)
    YYACCEPT;

  /* Shift the lookahead token.  */

#if YY_parse_DEBUG != 0
  if (YY_parse_DEBUG_FLAG)
    fprintf(stderr, "Shifting token %d (%s), ", YY_parse_CHAR, yytname[yychar1]);
#endif

  /* Discard the token being shifted unless it is eof.  */
  if (YY_parse_CHAR != YYEOF)
    YY_parse_CHAR = YYEMPTY;

  *++yyvsp = YY_parse_LVAL;
#ifdef YY_parse_LSP_NEEDED
  *++yylsp = YY_parse_LLOC;
#endif

  /* count tokens shifted since error; after three, turn off error status.  */
  if (yyerrstatus) yyerrstatus--;

  yystate = yyn;
  YYGOTO(yynewstate);

/* Do the default action for the current state.  */
YYLABEL(yydefault)

  yyn = yydefact[yystate];
  if (yyn == 0)
    YYGOTO(yyerrlab);

/* Do a reduction.  yyn is the number of a rule to reduce with.  */
YYLABEL(yyreduce)
  yylen = yyr2[yyn];
  if (yylen > 0)
    yyval = yyvsp[1-yylen]; /* implement default value of the action */

#if YY_parse_DEBUG != 0
  if (YY_parse_DEBUG_FLAG)
    {
      int i;

      fprintf (stderr, "Reducing via rule %d (line %d), ",
	       yyn, yyrline[yyn]);

      /* Print the symbols being reduced, and their result.  */
      for (i = yyprhs[yyn]; yyrhs[i] > 0; i++)
	fprintf (stderr, "%s ", yytname[yyrhs[i]]);
      fprintf (stderr, " -> %s\n", yytname[yyr1[yyn]]);
    }
#endif


/* #line 783 "/u/icdc/rdt/tools/lib/bison.cc" */
#line 1096 "y.tab.c"

  switch (yyn) {

case 1:
#line 53 "parse.y"
{ /* add default rule */
			int def_rule;

			pat = cclinit();
			cclnegate( pat );

			def_rule = mkstate( -pat );

			finish_rule( def_rule, false, 0, 0 );

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

			if ( spprdflt )
			    fputs( "YY_FATAL_ERROR( \"flex scanner jammed\" )",
				   temp_action_file );
			else
			    fputs( "ECHO", temp_action_file );

			fputs( ";\n\tYY_BREAK\n", temp_action_file );
			;
    break;}
case 2:
#line 77 "parse.y"
{
			/* initialize for processing rules */

			/* create default DFA start condition */
			scinstal( "INITIAL", false );
			;
    break;}
case 5:
#line 88 "parse.y"
{ synerr( "unknown error processing section 1" ); ;
    break;}
case 7:
#line 95 "parse.y"
{
			/* these productions are separate from the s1object
			 * rule because the semantics must be done before
			 * we parse the remainder of an s1object
			 */

			xcluflg = false;
			;
    break;}
case 8:
#line 105 "parse.y"
{ xcluflg = true; ;
    break;}
case 9:
#line 109 "parse.y"
{ scinstal( nmstr, xcluflg ); ;
    break;}
case 10:
#line 112 "parse.y"
{ scinstal( nmstr, xcluflg ); ;
    break;}
case 11:
#line 115 "parse.y"
{ synerr( "bad start condition list" ); ;
    break;}
case 14:
#line 123 "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;
			new_rule();
			;
    break;}
case 15:
#line 134 "parse.y"
{
			pat = yyvsp[0];
			finish_rule( pat, variable_trail_rule,
				     headcnt, trailcnt );

			for ( i = 1; i <= actvp; ++i )
			    scbol[actvsc[i]] =
				mkbranch( scbol[actvsc[i]], pat );

			if ( ! bol_needed )
			    {
			    bol_needed = true;

			    if ( performance_report )
				pinpoint_message( 
			    "'^' operator results in sub-optimal performance" );
			    }
			;
    break;}
case 16:
#line 154 "parse.y"
{
			pat = yyvsp[0];
			finish_rule( pat, variable_trail_rule,
				     headcnt, trailcnt );

			for ( i = 1; i <= actvp; ++i )
			    scset[actvsc[i]] =
				mkbranch( scset[actvsc[i]], pat );
			;
    break;}
case 17:
#line 165 "parse.y"
{
			pat = yyvsp[0];
			finish_rule( pat, variable_trail_rule,
				     headcnt, trailcnt );

			/* 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 )
				pinpoint_message(
			    "'^' operator results in sub-optimal performance" );
			    }
			;
    break;}
case 18:
#line 189 "parse.y"
{
			pat = yyvsp[0];
			finish_rule( pat, variable_trail_rule,
				     headcnt, trailcnt );

			for ( i = 1; i <= lastsc; ++i )
			    if ( ! scxclu[i] )
				scset[i] = mkbranch( scset[i], pat );
			;
    break;}
case 19:
#line 200 "parse.y"
{ build_eof_action(); ;
    break;}
case 20:
#line 203 "parse.y"
{
			/* this EOF applies to all start conditions
			 * which don't already have EOF actions
			 */
			actvp = 0;

			for ( i = 1; i <= lastsc; ++i )
			    if ( ! sceof[i] )
				actvsc[++actvp] = i;

			if ( actvp == 0 )
			    pinpoint_message(
		"warning - all start conditions already have <<EOF>> rules" );

			else
			    build_eof_action();
			;
    break;}
case 21:
#line 222 "parse.y"
{ synerr( "unrecognized rule" ); ;
    break;}
case 23:
#line 229 "parse.y"
{
			if ( (scnum = sclookup( nmstr )) == 0 )
			    format_pinpoint_message(
				"undeclared start condition %s", nmstr );

			else
			    actvsc[++actvp] = scnum;
			;
    break;}
case 24:
#line 239 "parse.y"
{
			if ( (scnum = sclookup( nmstr )) == 0 )
			    format_pinpoint_message(
				"undeclared start condition %s", nmstr );
			else
			    actvsc[actvp = 1] = scnum;
			;
    break;}
case 25:
#line 248 "parse.y"
{ synerr( "bad start condition list" ); ;
    break;}
case 26:
#line 252 "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 )
				{
				fprintf( stderr,
    "%s: warning - trailing context rule at line %d made variable because\n",
					 program_name, linenum );
				fprintf( stderr,
					 "      of preceding '|' action\n" );
				}

			    /* mark as variable */
			    varlength = true;
			    headcnt = 0;
			    }

			if ( varlength && headcnt == 0 )
			    { /* variable trailing context rule */
			    /* mark the first part of the rule as the accepting
			     * "head" part of a trailing context rule
			     */
			    /* by the way, we didn't do this at the beginning
			     * of this production because back then
			     * current_state_type was set up for a trail
			     * rule, and add_accept() can create a new
			     * state ...
			     */
			    add_accept( yyvsp[-1], num_rules | YY_TRAILING_HEAD_MASK );
			    variable_trail_rule = true;
			    }
			
			else
			    trailcnt = rulelen;

			yyval = link_machines( yyvsp[-1], yyvsp[0] );
			;
    break;}
case 27:
#line 309 "parse.y"
{ synerr( "trailing context used twice" ); ;
    break;}
case 28:
#line 312 "parse.y"
{
			if ( trlcontxt )
			    {
			    synerr( "trailing context used twice" );
			    yyval = mkstate( SYM_EPSILON );
			    }

			else if ( previous_continued_action )
			    {
			    /* see the comment in the rule for "re2 re"
			     * above
			     */
			    if ( ! varlength || headcnt != 0 )
				{
				fprintf( stderr,
    "%s: warning - trailing context rule at line %d made variable because\n",
					 program_name, linenum );
				fprintf( stderr,
					 "      of preceding '|' action\n" );
				}

			    /* mark as variable */
			    varlength = true;
			    headcnt = 0;
			    }

 			if ( varlength && headcnt == 0 )
 			    {
 			    /* again, see the comment in the rule for "re2 re"
 			     * above
 			     */
 			    add_accept( yyvsp[-1], num_rules | YY_TRAILING_HEAD_MASK );
 			    variable_trail_rule = true;
 			    }

 			else
 			    {
 			    if ( ! varlength )
 				headcnt = rulelen;

 			    ++rulelen;
 			    trailcnt = 1;
 			    }

			trlcontxt = true;

			eps = mkstate( SYM_EPSILON );
			yyval = link_machines( yyvsp[-1],
				 link_machines( eps, mkstate( '\n' ) ) );
			;
    break;}
case 29:
#line 364 "parse.y"
{
		        yyval = yyvsp[0];

			if ( trlcontxt )
			    {
			    if ( varlength && headcnt == 0 )
				/* both head and trail are variable-length */
				variable_trail_rule = true;
			    else
				trailcnt = rulelen;
			    }
		        ;
    break;}
case 30:
#line 380 "parse.y"
{
			varlength = true;
			yyval = mkor( yyvsp[-2], yyvsp[0] );
			;
    break;}
case 31:
#line 386 "parse.y"
{ yyval = yyvsp[0]; ;
    break;}
case 32:
#line 391 "parse.y"
{
			/* this rule is written separately so
			 * the reduction will occur before the trailing
			 * series is parsed
			 */

			if ( trlcontxt )
			    synerr( "trailing context used twice" );
			else
			    trlcontxt = true;

			if ( varlength )
			    /* we hope the trailing context is fixed-length */
			    varlength = false;
			else
			    headcnt = rulelen;

			rulelen = 0;

			current_state_type = STATE_TRAILING_CONTEXT;
			yyval = yyvsp[-1];
			;
    break;}
case 33:
#line 416 "parse.y"
{
			/* this is where concatenation of adjacent patterns
			 * gets done
			 */
			yyval = link_machines( yyvsp[-1], yyvsp[0] );
			;
    break;}
case 34:
#line 424 "parse.y"
{ yyval = yyvsp[0]; ;
    break;}
case 35:
#line 428 "parse.y"
{
			varlength = true;

			yyval = mkclos( yyvsp[-1] );
			;
    break;}
case 36:
#line 435 "parse.y"
{
			varlength = true;

			yyval = mkposcl( yyvsp[-1] );
			;
    break;}
case 37:
#line 442 "parse.y"
{
			varlength = true;

			yyval = mkopt( yyvsp[-1] );