lr.tab.c

L属性定义的利用lex和yacc做的计算器。

#ifdef YYPARSE_PARAM
#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
int
yyparse (void *YYPARSE_PARAM)
#else
int
yyparse (YYPARSE_PARAM)
    void *YYPARSE_PARAM;
#endif
#else /* ! YYPARSE_PARAM */
#if (defined __STDC__ || defined __C99__FUNC__ \
     || defined __cplusplus || defined _MSC_VER)
int
yyparse (void)
#else
int
yyparse ()

#endif
#endif
{
  
  int yystate;
  int yyn;
  int yyresult;
  /* Number of tokens to shift before error messages enabled.  */
  int yyerrstatus;
  /* Look-ahead token as an internal (translated) token number.  */
  int yytoken = 0;
#if YYERROR_VERBOSE
  /* Buffer for error messages, and its allocated size.  */
  char yymsgbuf[128];
  char *yymsg = yymsgbuf;
  YYSIZE_T yymsg_alloc = sizeof yymsgbuf;
#endif

  /* Three stacks and their tools:
     `yyss': related to states,
     `yyvs': related to semantic values,
     `yyls': related to locations.

     Refer to the stacks thru separate pointers, to allow yyoverflow
     to reallocate them elsewhere.  */

  /* The state stack.  */
  yytype_int16 yyssa[YYINITDEPTH];
  yytype_int16 *yyss = yyssa;
  yytype_int16 *yyssp;

  /* The semantic value stack.  */
  YYSTYPE yyvsa[YYINITDEPTH];
  YYSTYPE *yyvs = yyvsa;
  YYSTYPE *yyvsp;



#define YYPOPSTACK(N)   (yyvsp -= (N), yyssp -= (N))

  YYSIZE_T yystacksize = YYINITDEPTH;

  /* The variables used to return semantic value and location from the
     action routines.  */
  YYSTYPE yyval;


  /* The number of symbols on the RHS of the reduced rule.
     Keep to zero when no symbol should be popped.  */
  int yylen = 0;

  YYDPRINTF ((stderr, "Starting parse\n"));

  yystate = 0;
  yyerrstatus = 0;
  yynerrs = 0;
  yychar = YYEMPTY;		/* Cause a token to be read.  */

  /* Initialize stack pointers.
     Waste one element of value and location stack
     so that they stay on the same level as the state stack.
     The wasted elements are never initialized.  */

  yyssp = yyss;
  yyvsp = yyvs;

  goto yysetstate;

/*------------------------------------------------------------.
| yynewstate -- Push a new state, which is found in yystate.  |
`------------------------------------------------------------*/
 yynewstate:
  /* In all cases, when you get here, the value and location stacks
     have just been pushed.  So pushing a state here evens the stacks.  */
  yyssp++;

 yysetstate:
  *yyssp = yystate;

  if (yyss + yystacksize - 1 <= yyssp)
    {
      /* Get the current used size of the three stacks, in elements.  */
      YYSIZE_T yysize = yyssp - yyss + 1;

#ifdef yyoverflow
      {
	/* Give user a chance to reallocate the stack.  Use copies of
	   these so that the &'s don't force the real ones into
	   memory.  */
	YYSTYPE *yyvs1 = yyvs;
	yytype_int16 *yyss1 = yyss;


	/* Each stack pointer address is followed by the size of the
	   data in use in that stack, in bytes.  This used to be a
	   conditional around just the two extra args, but that might
	   be undefined if yyoverflow is a macro.  */
	yyoverflow (YY_("memory exhausted"),
		    &yyss1, yysize * sizeof (*yyssp),
		    &yyvs1, yysize * sizeof (*yyvsp),

		    &yystacksize);

	yyss = yyss1;
	yyvs = yyvs1;
      }
#else /* no yyoverflow */
# ifndef YYSTACK_RELOCATE
      goto yyexhaustedlab;
# else
      /* Extend the stack our own way.  */
      if (YYMAXDEPTH <= yystacksize)
	goto yyexhaustedlab;
      yystacksize *= 2;
      if (YYMAXDEPTH < yystacksize)
	yystacksize = YYMAXDEPTH;

      {
	yytype_int16 *yyss1 = yyss;
	union yyalloc *yyptr =
	  (union yyalloc *) YYSTACK_ALLOC (YYSTACK_BYTES (yystacksize));
	if (! yyptr)
	  goto yyexhaustedlab;
	YYSTACK_RELOCATE (yyss);
	YYSTACK_RELOCATE (yyvs);

#  undef YYSTACK_RELOCATE
	if (yyss1 != yyssa)
	  YYSTACK_FREE (yyss1);
      }
# endif
#endif /* no yyoverflow */

      yyssp = yyss + yysize - 1;
      yyvsp = yyvs + yysize - 1;


      YYDPRINTF ((stderr, "Stack size increased to %lu\n",
		  (unsigned long int) yystacksize));

      if (yyss + yystacksize - 1 <= yyssp)
	YYABORT;
    }

  YYDPRINTF ((stderr, "Entering state %d\n", yystate));

  goto yybackup;

/*-----------.
| yybackup.  |
`-----------*/
yybackup:

  /* Do appropriate processing given the current state.  Read a
     look-ahead token if we need one and don't already have one.  */

  /* First try to decide what to do without reference to look-ahead token.  */
  yyn = yypact[yystate];
  if (yyn == YYPACT_NINF)
    goto yydefault;

  /* Not known => get a look-ahead token if don't already have one.  */

  /* YYCHAR is either YYEMPTY or YYEOF or a valid look-ahead symbol.  */
  if (yychar == YYEMPTY)
    {
      YYDPRINTF ((stderr, "Reading a token: "));
      yychar = YYLEX;
    }

  if (yychar <= YYEOF)
    {
      yychar = yytoken = YYEOF;
      YYDPRINTF ((stderr, "Now at end of input.\n"));
    }
  else
    {
      yytoken = YYTRANSLATE (yychar);
      YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
    }

  /* If the proper action on seeing token YYTOKEN is to reduce or to
     detect an error, take that action.  */
  yyn += yytoken;
  if (yyn < 0 || YYLAST < yyn || yycheck[yyn] != yytoken)
    goto yydefault;
  yyn = yytable[yyn];
  if (yyn <= 0)
    {
      if (yyn == 0 || yyn == YYTABLE_NINF)
	goto yyerrlab;
      yyn = -yyn;
      goto yyreduce;
    }

  if (yyn == YYFINAL)
    YYACCEPT;

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

  /* Shift the look-ahead token.  */
  YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);

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

  yystate = yyn;
  *++yyvsp = yylval;

  goto yynewstate;


/*-----------------------------------------------------------.
| yydefault -- do the default action for the current state.  |
`-----------------------------------------------------------*/
yydefault:
  yyn = yydefact[yystate];
  if (yyn == 0)
    goto yyerrlab;
  goto yyreduce;


/*-----------------------------.
| yyreduce -- Do a reduction.  |
`-----------------------------*/
yyreduce:
  /* yyn is the number of a rule to reduce with.  */
  yylen = yyr2[yyn];

  /* If YYLEN is nonzero, implement the default value of the action:
     `$$ = $1'.

     Otherwise, the following line sets YYVAL to garbage.
     This behavior is undocumented and Bison
     users should not rely upon it.  Assigning to YYVAL
     unconditionally makes the parser a bit smaller, and it avoids a
     GCC warning that YYVAL may be used uninitialized.  */
  yyval = yyvsp[1-yylen];


  YY_REDUCE_PRINT (yyn);
  switch (yyn)
    {
        case 2:
#line 9 "lr.y"
    { (yyvsp[(2) - (3)]) = (yyvsp[(1) - (3)]); ;}
    break;

  case 5:
#line 12 "lr.y"
    { (yyvsp[(1) - (3)]) = (yyval); (yyvsp[(3) - (3)]) = (yyval); printf("%d", (yyvsp[(3) - (3)])); ;}
    break;

  case 6:
#line 13 "lr.y"
    { (yyvsp[(1) - (1)]) = (yyval); printf("%d", (yyvsp[(1) - (1)]));;}
    break;


/* Line 1267 of yacc.c.  */
#line 1319 "lr.tab.c"
      default: break;
    }
  YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyn], &yyval, &yyloc);

  YYPOPSTACK (yylen);
  yylen = 0;
  YY_STACK_PRINT (yyss, yyssp);

  *++yyvsp = yyval;


  /* 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
      yyerror (YY_("syntax error"));
#else
      {
	YYSIZE_T yysize = yysyntax_error (0, yystate, yychar);
	if (yymsg_alloc < yysize && yymsg_alloc < YYSTACK_ALLOC_MAXIMUM)
	  {
	    YYSIZE_T yyalloc = 2 * yysize;
	    if (! (yysize <= yyalloc && yyalloc <= YYSTACK_ALLOC_MAXIMUM))
	      yyalloc = YYSTACK_ALLOC_MAXIMUM;
	    if (yymsg != yymsgbuf)
	      YYSTACK_FREE (yymsg);
	    yymsg = (char *) YYSTACK_ALLOC (yyalloc);
	    if (yymsg)
	      yymsg_alloc = yyalloc;
	    else
	      {
		yymsg = yymsgbuf;
		yymsg_alloc = sizeof yymsgbuf;
	      }
	  }

	if (0 < yysize && yysize <= yymsg_alloc)
	  {
	    (void) yysyntax_error (yymsg, yystate, yychar);
	    yyerror (yymsg);
	  }
	else
	  {
	    yyerror (YY_("syntax error"));
	    if (yysize != 0)
	      goto yyexhaustedlab;
	  }
      }
#endif
    }



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

      if (yychar <= YYEOF)
	{
	  /* Return failure if at end of input.  */
	  if (yychar == YYEOF)
	    YYABORT;
	}
      else
	{
	  yydestruct ("Error: discarding",
		      yytoken, &yylval);
	  yychar = YYEMPTY;
	}
    }

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


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

  /* Pacify compilers like GCC when the user code never invokes
     YYERROR and the label yyerrorlab therefore never appears in user
     code.  */
  if (/*CONSTCOND*/ 0)
     goto yyerrorlab;

  /* Do not reclaim the symbols of the rule which action triggered
     this YYERROR.  */
  YYPOPSTACK (yylen);
  yylen = 0;
  YY_STACK_PRINT (yyss, yyssp);
  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;


      yydestruct ("Error: popping",
		  yystos[yystate], yyvsp);
      YYPOPSTACK (1);
      yystate = *yyssp;
      YY_STACK_PRINT (yyss, yyssp);
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  *++yyvsp = yylval;


  /* 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:
  yyresult = 1;
  goto yyreturn;

#ifndef yyoverflow
/*-------------------------------------------------.
| yyexhaustedlab -- memory exhaustion comes here.  |
`-------------------------------------------------*/
yyexhaustedlab:
  yyerror (YY_("memory exhausted"));
  yyresult = 2;
  /* Fall through.  */
#endif

yyreturn:
  if (yychar != YYEOF && yychar != YYEMPTY)
     yydestruct ("Cleanup: discarding lookahead",
		 yytoken, &yylval);
  /* Do not reclaim the symbols of the rule which action triggered
     this YYABORT or YYACCEPT.  */
  YYPOPSTACK (yylen);
  YY_STACK_PRINT (yyss, yyssp);
  while (yyssp != yyss)
    {
      yydestruct ("Cleanup: popping",
		  yystos[*yyssp], yyvsp);
      YYPOPSTACK (1);
    }
#ifndef yyoverflow
  if (yyss != yyssa)
    YYSTACK_FREE (yyss);
#endif
#if YYERROR_VERBOSE
  if (yymsg != yymsgbuf)
    YYSTACK_FREE (yymsg);
#endif
  /* Make sure YYID is used.  */
  return YYID (yyresult);
}


#line 14 "lr.y"


int yyerror(char *msg)
{
    fprintf(stderr, msg);
}

int main()
{
	yyparse();
        return 1;
}


#include "lex.yy.c"