parse-gram.c

bison 2.0 主要可以用来做语法分析用的

#line 308 "parse-gram.y"
    { (yyval.list) = symbol_list_prepend ((yyvsp[-1].list), (yyvsp[0].symbol), (yylsp[0])); }
    break;

  case 50:
#line 314 "parse-gram.y"
    {
       current_type = (yyvsp[0].uniqstr);
     }
    break;

  case 51:
#line 318 "parse-gram.y"
    {
       symbol_class_set ((yyvsp[0].symbol), current_class, (yylsp[0]));
       symbol_type_set ((yyvsp[0].symbol), current_type, (yylsp[0]));
     }
    break;

  case 52:
#line 323 "parse-gram.y"
    {
      symbol_class_set ((yyvsp[-1].symbol), current_class, (yylsp[-1]));
      symbol_type_set ((yyvsp[-1].symbol), current_type, (yylsp[-1]));
      symbol_user_token_number_set ((yyvsp[-1].symbol), (yyvsp[0].integer), (yylsp[0]));
    }
    break;

  case 53:
#line 329 "parse-gram.y"
    {
      symbol_class_set ((yyvsp[-1].symbol), current_class, (yylsp[-1]));
      symbol_type_set ((yyvsp[-1].symbol), current_type, (yylsp[-1]));
      symbol_make_alias ((yyvsp[-1].symbol), (yyvsp[0].symbol), (yyloc));
    }
    break;

  case 54:
#line 335 "parse-gram.y"
    {
      symbol_class_set ((yyvsp[-2].symbol), current_class, (yylsp[-2]));
      symbol_type_set ((yyvsp[-2].symbol), current_type, (yylsp[-2]));
      symbol_user_token_number_set ((yyvsp[-2].symbol), (yyvsp[-1].integer), (yylsp[-1]));
      symbol_make_alias ((yyvsp[-2].symbol), (yyvsp[0].symbol), (yyloc));
    }
    break;

  case 60:
#line 364 "parse-gram.y"
    {
      if (yacc_flag)
	complain_at ((yyloc), _("POSIX forbids declarations in the grammar"));
    }
    break;

  case 61:
#line 369 "parse-gram.y"
    {
      yyerrok;
    }
    break;

  case 62:
#line 375 "parse-gram.y"
    { current_lhs = (yyvsp[0].symbol); current_lhs_location = (yylsp[0]); }
    break;

  case 64:
#line 379 "parse-gram.y"
    { grammar_rule_end ((yylsp[0])); }
    break;

  case 65:
#line 380 "parse-gram.y"
    { grammar_rule_end ((yylsp[0])); }
    break;

  case 67:
#line 386 "parse-gram.y"
    { grammar_rule_begin (current_lhs, current_lhs_location); }
    break;

  case 68:
#line 388 "parse-gram.y"
    { grammar_current_rule_symbol_append ((yyvsp[0].symbol), (yylsp[0])); }
    break;

  case 69:
#line 390 "parse-gram.y"
    { grammar_current_rule_action_append ((yyvsp[0].chars), (yylsp[0])); }
    break;

  case 70:
#line 392 "parse-gram.y"
    { grammar_current_rule_prec_set ((yyvsp[0].symbol), (yylsp[0])); }
    break;

  case 71:
#line 394 "parse-gram.y"
    { grammar_current_rule_dprec_set ((yyvsp[0].integer), (yylsp[0])); }
    break;

  case 72:
#line 396 "parse-gram.y"
    { grammar_current_rule_merge_set ((yyvsp[0].uniqstr), (yylsp[0])); }
    break;

  case 73:
#line 400 "parse-gram.y"
    { (yyval.symbol) = (yyvsp[0].symbol); }
    break;

  case 74:
#line 401 "parse-gram.y"
    { (yyval.symbol) = (yyvsp[0].symbol); }
    break;

  case 75:
#line 406 "parse-gram.y"
    { (yyval.chars) = (yyvsp[0].chars); }
    break;

  case 76:
#line 412 "parse-gram.y"
    {
      (yyval.symbol) = symbol_get ((yyvsp[0].chars), (yylsp[0]));
      symbol_class_set ((yyval.symbol), token_sym, (yylsp[0]));
    }
    break;

  case 77:
#line 421 "parse-gram.y"
    {
      (yyval.chars) = (yyvsp[0].chars) + 1;
      (yyval.chars)[strlen ((yyval.chars)) - 1] = '\0';
    }
    break;

  case 79:
#line 430 "parse-gram.y"
    {
      muscle_code_grow ("epilogue", (yyvsp[0].chars), (yylsp[0]));
      scanner_last_string_free ();
    }
    break;


    }

/* Line 1037 of yacc.c.  */
#line 1739 "parse-gram.c"

  yyvsp -= yylen;
  yyssp -= yylen;
  yylsp -= yylen;

  YY_STACK_PRINT (yyss, yyssp);

  *++yyvsp = yyval;
  *++yylsp = yyloc;

  /* Now `shift' the result of the reduction.  Determine what state
     that goes to, based on the state we popped back to and the rule
     number reduced by.  */

  yyn = yyr1[yyn];

  yystate = yypgoto[yyn - YYNTOKENS] + *yyssp;
  if (0 <= yystate && yystate <= YYLAST && yycheck[yystate] == *yyssp)
    yystate = yytable[yystate];
  else
    yystate = yydefgoto[yyn - YYNTOKENS];

  goto yynewstate;


/*------------------------------------.
| yyerrlab -- here on detecting error |
`------------------------------------*/
yyerrlab:
  /* If not already recovering from an error, report this error.  */
  if (!yyerrstatus)
    {
      ++yynerrs;
#if YYERROR_VERBOSE
      yyn = yypact[yystate];

      if (YYPACT_NINF < yyn && yyn < YYLAST)
	{
	  YYSIZE_T yysize = 0;
	  int yytype = YYTRANSLATE (yychar);
	  const char* yyprefix;
	  char *yymsg;
	  int yyx;

	  /* Start YYX at -YYN if negative to avoid negative indexes in
	     YYCHECK.  */
	  int yyxbegin = yyn < 0 ? -yyn : 0;

	  /* Stay within bounds of both yycheck and yytname.  */
	  int yychecklim = YYLAST - yyn;
	  int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
	  int yycount = 0;

	  yyprefix = ", expecting ";
	  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
	    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
	      {
		yysize += yystrlen (yyprefix) + yystrlen (yytname [yyx]);
		yycount += 1;
		if (yycount == 5)
		  {
		    yysize = 0;
		    break;
		  }
	      }
	  yysize += (sizeof ("syntax error, unexpected ")
		     + yystrlen (yytname[yytype]));
	  yymsg = (char *) YYSTACK_ALLOC (yysize);
	  if (yymsg != 0)
	    {
	      char *yyp = yystpcpy (yymsg, "syntax error, unexpected ");
	      yyp = yystpcpy (yyp, yytname[yytype]);

	      if (yycount < 5)
		{
		  yyprefix = ", expecting ";
		  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
		    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
		      {
			yyp = yystpcpy (yyp, yyprefix);
			yyp = yystpcpy (yyp, yytname[yyx]);
			yyprefix = " or ";
		      }
		}
	      yyerror (yymsg);
	      YYSTACK_FREE (yymsg);
	    }
	  else
	    yyerror ("syntax error; also virtual memory exhausted");
	}
      else
#endif /* YYERROR_VERBOSE */
	yyerror ("syntax error");
    }

  yyerror_range[0] = yylloc;

  if (yyerrstatus == 3)
    {
      /* If just tried and failed to reuse look-ahead token after an
	 error, discard it.  */

      if (yychar <= YYEOF)
        {
          /* If at end of input, pop the error token,
	     then the rest of the stack, then return failure.  */
	  if (yychar == YYEOF)
	     for (;;)
	       {
                 yyerror_range[0] = *yylsp;
		 YYPOPSTACK;
		 if (yyssp == yyss)
		   YYABORT;
		 yydestruct ("Error: popping",
                             yystos[*yyssp], yyvsp, yylsp);
	       }
        }
      else
	{
	  yydestruct ("Error: discarding", yytoken, &yylval, &yylloc);
	  yychar = YYEMPTY;
	}
    }

  /* Else will try to reuse look-ahead token after shifting the error
     token.  */
  goto yyerrlab1;


/*---------------------------------------------------.
| yyerrorlab -- error raised explicitly by YYERROR.  |
`---------------------------------------------------*/
yyerrorlab:

#ifdef __GNUC__
  /* Pacify GCC when the user code never invokes YYERROR and the label
     yyerrorlab therefore never appears in user code.  */
  if (0)
     goto yyerrorlab;
#endif

  yyerror_range[0] = yylsp[1-yylen];
  yylsp -= yylen;
  yyvsp -= yylen;
  yyssp -= yylen;
  yystate = *yyssp;
  goto yyerrlab1;


/*-------------------------------------------------------------.
| yyerrlab1 -- common code for both syntax error and YYERROR.  |
`-------------------------------------------------------------*/
yyerrlab1:
  yyerrstatus = 3;	/* Each real token shifted decrements this.  */

  for (;;)
    {
      yyn = yypact[yystate];
      if (yyn != YYPACT_NINF)
	{
	  yyn += YYTERROR;
	  if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYTERROR)
	    {
	      yyn = yytable[yyn];
	      if (0 < yyn)
		break;
	    }
	}

      /* Pop the current state because it cannot handle the error token.  */
      if (yyssp == yyss)
	YYABORT;

      yyerror_range[0] = *yylsp;
      yydestruct ("Error: popping", yystos[yystate], yyvsp, yylsp);
      YYPOPSTACK;
      yystate = *yyssp;
      YY_STACK_PRINT (yyss, yyssp);
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  *++yyvsp = yylval;

  yyerror_range[1] = yylloc;
  /* Using YYLLOC is tempting, but would change the location of
     the look-ahead.  YYLOC is available though. */
  YYLLOC_DEFAULT (yyloc, yyerror_range - 1, 2);
  *++yylsp = yyloc;

  /* Shift the error token. */
  YY_SYMBOL_PRINT ("Shifting", yystos[yyn], yyvsp, yylsp);

  yystate = yyn;
  goto yynewstate;


/*-------------------------------------.
| yyacceptlab -- YYACCEPT comes here.  |
`-------------------------------------*/
yyacceptlab:
  yyresult = 0;
  goto yyreturn;

/*-----------------------------------.
| yyabortlab -- YYABORT comes here.  |
`-----------------------------------*/
yyabortlab:
  yydestruct ("Error: discarding lookahead",
              yytoken, &yylval, &yylloc);
  yychar = YYEMPTY;
  yyresult = 1;
  goto yyreturn;

#ifndef yyoverflow
/*----------------------------------------------.
| yyoverflowlab -- parser overflow comes here.  |
`----------------------------------------------*/
yyoverflowlab:
  yyerror ("parser stack overflow");
  yyresult = 2;
  /* Fall through.  */
#endif

yyreturn:
#ifndef yyoverflow
  if (yyss != yyssa)
    YYSTACK_FREE (yyss);
#endif
  return yyresult;
}


#line 436 "parse-gram.y"



/* Return the location of the left-hand side of a rule whose
   right-hand side is RHS[1] ... RHS[N].  Ignore empty nonterminals in
   the right-hand side, and return an empty location equal to the end
   boundary of RHS[0] if the right-hand side is empty.  */

static YYLTYPE
lloc_default (YYLTYPE const *rhs, int n)
{
  int i;
  YYLTYPE loc;

  /* SGI MIPSpro 7.4.1m miscompiles "loc.start = loc.end = rhs[n].end;".
     The bug is fixed in 7.4.2m, but play it safe for now.  */
  loc.start = rhs[n].end;
  loc.end = rhs[n].end;

  /* Ignore empty nonterminals the start of the the right-hand side.
     Do not bother to ignore them at the end of the right-hand side,
     since empty nonterminals have the same end as their predecessors.  */
  for (i = 1; i <= n; i++)
    if (! equal_boundaries (rhs[i].start, rhs[i].end))
      {
	loc.start = rhs[i].start;
	break;
      }

  return loc;
}


/* Add a lex-param or a parse-param (depending on TYPE) with
   declaration DECL and location LOC.  */

static void
add_param (char const *type, char *decl, location loc)
{
  static char const alphanum[26 + 26 + 1 + 10] =
    "abcdefghijklmnopqrstuvwxyz"
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "_"
    "0123456789";
  char const *name_start = NULL;
  char *p;

  /* Stop on last actual character.  */
  for (p = decl; p[1]; p++)
    if ((p == decl
	 || ! memchr (alphanum, p[-1], sizeof alphanum))
	&& memchr (alphanum, p[0], sizeof alphanum - 10))
      name_start = p;

  /* Strip the surrounding '{' and '}', and any blanks just inside
     the braces.  */
  while (*--p == ' ' || *p == '\t')
    continue;
  p[1] = '\0';
  while (*++decl == ' ' || *decl == '\t')
    continue;

  if (! name_start)
    complain_at (loc, _("missing identifier in parameter declaration"));
  else
    {
      char *name;
      size_t name_len;

      for (name_len = 1;
	   memchr (alphanum, name_start[name_len], sizeof alphanum);
	   name_len++)
	continue;

      name = xmalloc (name_len + 1);
      memcpy (name, name_start, name_len);
      name[name_len] = '\0';
      muscle_pair_list_grow (type, decl, name);
      free (name);
    }

  scanner_last_string_free ();
}

/*----------------------------------------------------.
| When debugging the parser, display tokens' values.  |
`----------------------------------------------------*/

static void
print_token_value (FILE *file, int type, YYSTYPE const *value)
{
  fputc (' ', file);
  switch (type)
    {
    case ID:
      fprintf (file, " = %s", value->symbol->tag);
      break;

    case INT:
      fprintf (file, " = %d", value->integer);
      break;

    case STRING:
      fprintf (file, " = \"%s\"", value->chars);
      break;

    case TYPE:
      fprintf (file, " = <%s>", value->uniqstr);
      break;

    case BRACED_CODE:
    case PERCENT_DESTRUCTOR:
    case PERCENT_LEX_PARAM:
    case PERCENT_PARSE_PARAM:
    case PERCENT_PRINTER:
    case PERCENT_UNION:
    case PROLOGUE:
    case EPILOGUE:
      fprintf (file, " = {{ %s }}", value->chars);
      break;

    default:
      fprintf (file, "unknown token type");
      break;
    }
}

static void
gram_error (location const *loc, char const *msg)
{
  complain_at (*loc, "%s", msg);
}

char const *
token_name (int type)
{
  return yytname[type];
}