y.tab.c

本源码为一个编译原理课程设计程序,它采用了YACC和LEX实现了一个功能强大的计算器编译器!

  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;

  /* Shift the lookahead token.  */
  YYDPRINTF ((stderr, "Shifting token %s, ", yytname[yytoken]));

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

  *++yyvsp = yylval;


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

  yystate = yyn;
  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 3:
#line 39 "calc.y"
    {printf("--> ");}
    break;

  case 4:
#line 40 "calc.y"
    {yyerrok;printf("\n--> ");}
    break;

  case 7:
#line 45 "calc.y"
    {
		if(dflag==DEC_ON)printf( "\t=%g\n--> " , yyvsp[0] );
		else if(dflag==HEX_ON)printf( "\t=0x%08X\n--> " , (BIGINT)yyvsp[0] );
		else printf( "\t=0%o\n--> " , (BIGINT)yyvsp[0] );
		}
    break;

  case 8:
#line 50 "calc.y"
    {
			       i=(int)yyvsp[-2]; reg[i] = yyvsp[0] ; 
			       if(dflag==DEC_ON) printf( "\t%c=%g\n--> " , 'a'+i,reg[i] );
			       else if(dflag==HEX_ON) printf( "\t%c=0x%08X\n--> " , 'a'+i,(BIGINT)reg[i] );
			       else  printf( "\t%c=0%o\n--> " , 'a'+i,(BIGINT)reg[i] );
			      }
    break;

  case 9:
#line 58 "calc.y"
    { yyval = yyvsp[-2] + yyvsp[0] ; }
    break;

  case 10:
#line 59 "calc.y"
    { yyval = yyvsp[-2] - yyvsp[0] ; }
    break;

  case 11:
#line 60 "calc.y"
    { yyval = yyvsp[-2] * yyvsp[0] ; }
    break;

  case 12:
#line 61 "calc.y"
    { yyval = yyvsp[-2] / yyvsp[0] ; }
    break;

  case 13:
#line 62 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] % (BIGINT)yyvsp[0] ; }
    break;

  case 14:
#line 63 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] & (BIGINT)yyvsp[0] ; }
    break;

  case 15:
#line 64 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] | (BIGINT)yyvsp[0] ; }
    break;

  case 16:
#line 65 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] ^ (BIGINT)yyvsp[0] ; }
    break;

  case 17:
#line 66 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] << (BIGINT)yyvsp[0] ; }
    break;

  case 18:
#line 67 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] >> (BIGINT)yyvsp[0] ; }
    break;

  case 19:
#line 68 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] && (BIGINT)yyvsp[0] ; }
    break;

  case 20:
#line 69 "calc.y"
    { yyval = (BIGINT)yyvsp[-2] || (BIGINT)yyvsp[0] ; }
    break;

  case 21:
#line 70 "calc.y"
    { yyval = yyvsp[-2]<yyvsp[0]?1:0; }
    break;

  case 22:
#line 71 "calc.y"
    { yyval = yyvsp[-2]>yyvsp[0]?1:0; }
    break;

  case 23:
#line 72 "calc.y"
    { yyval = yyvsp[-1] ; }
    break;

  case 24:
#line 73 "calc.y"
    { yyval = -yyvsp[0] ; }
    break;

  case 25:
#line 74 "calc.y"
    { yyval = ~((BIGINT)yyvsp[0]); }
    break;

  case 26:
#line 75 "calc.y"
    { yyval = !( (BIGINT)yyvsp[0] ) ; }
    break;

  case 27:
#line 76 "calc.y"
    { yyval = yyvsp[0] ; }
    break;

  case 28:
#line 77 "calc.y"
    { ival=(int)yyvsp[0];yyval = reg[ival] ; }
    break;

  case 29:
#line 78 "calc.y"
    { yyval =sin(yyvsp[0]) ; }
    break;

  case 30:
#line 79 "calc.y"
    { yyval =cos(yyvsp[0]) ; }
    break;

  case 31:
#line 80 "calc.y"
    { yyval =tan(yyvsp[0]) ; }
    break;

  case 32:
#line 81 "calc.y"
    { yyval =log(yyvsp[0]) ; }
    break;

  case 33:
#line 82 "calc.y"
    { yyval =abs(yyvsp[0]) ; }
    break;

  case 34:
#line 83 "calc.y"
    { yyval =sqrt(yyvsp[0]) ; }
    break;

  case 35:
#line 86 "calc.y"
    { exit(0); }
    break;

  case 36:
#line 87 "calc.y"
    { printf("\033[2J\033[1;1H\n--> "); }
    break;

  case 37:
#line 88 "calc.y"
    { dflag=HEX_ON; printf(">> Hex display mod on!\n--> "); }
    break;

  case 38:
#line 89 "calc.y"
    { dflag=DEC_ON; printf(">> Dec display mod on!\n--> "); }
    break;

  case 39:
#line 90 "calc.y"
    { dflag=OCT_ON; printf(">> Oct display mod on!\n--> "); }
    break;

  case 40:
#line 91 "calc.y"
    { 
			for(i=0;i<26;i++)
			{
			    if(dflag==DEC_ON)printf("\t%c=%g\n",'a'+i,reg[i]); 
			    else if(dflag==HEX_ON)printf("\t%c=0x%08X\n",'a'+i,(BIGINT)reg[i]);
			    else printf("\t%c=0%o\n",'a'+i,(BIGINT)reg[i]);
			 }
		 printf("--> ");
		 }
    break;

  case 41:
#line 100 "calc.y"
    { for(i=0;i<26;i++)reg[i]=0; printf(">>All registers erased!\n--> ");}
    break;

  case 42:
#line 101 "calc.y"
    {
			 printf(">> COMMANDS:\n");
			 printf("> help: Display this help section.\n");
			 printf("> clear: Clear the screen.\n");
			 printf("> dec: Decimal mode to display  numbers or registers.\n");
			 printf("> hex: Hexadecimal mode to display numbers or registers.\n");
			 printf("> oct: Octal mode to display numbers or registers.\n");
			 printf("> list: List the values in the 26 registers which are ranged from 'a'/'A' to 'z'/'Z'.\n");
			 printf("> erase: Reset all registers to 0.\n");
			 printf("> exit: Quit this program.\n");
			 printf("--> ");
			 }
    break;


    }

/* Line 999 of yacc.c.  */
#line 1349 "y.tab.c"

  yyvsp -= yylen;
  yyssp -= yylen;


  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
      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");
    }



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

      /* Return failure if at end of input.  */
      if (yychar == YYEOF)
        {
	  /* Pop the error token.  */
          YYPOPSTACK;
	  /* Pop the rest of the stack.  */
	  while (yyss < yyssp)
	    {
	      YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
	      yydestruct (yystos[*yyssp], yyvsp);
	      YYPOPSTACK;
	    }
	  YYABORT;
        }

      YYDSYMPRINTF ("Error: discarding", yytoken, &yylval, &yylloc);
      yydestruct (yytoken, &yylval);
      yychar = YYEMPTY;

    }

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


/*----------------------------------------------------.
| yyerrlab1 -- error raised explicitly by an action.  |
`----------------------------------------------------*/
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;

      YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
      yydestruct (yystos[yystate], yyvsp);
      yyvsp--;
      yystate = *--yyssp;

      YY_STACK_PRINT (yyss, yyssp);
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  YYDPRINTF ((stderr, "Shifting error token, "));

  *++yyvsp = yylval;


  yystate = yyn;
  goto yynewstate;


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

/*-----------------------------------.
| yyabortlab -- YYABORT comes here.  |
`-----------------------------------*/
yyabortlab:
  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 115 "calc.y"


int yyerror(char *str)
{
         fprintf(stderr,"Error: %s\n",str);
         return 1;      
}

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