plural.c

研读AxCrypt对加解密的处理方法

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

  switch (yyn) {

case 1:
#line 151 "plural.y"
{
	    if (yyvsp[0].exp == NULL)
	      YYABORT;
	    ((struct parse_args *) arg)->res = yyvsp[0].exp;
	  }
    break;
case 2:
#line 159 "plural.y"
{
	    yyval.exp = new_exp_3 (qmop, yyvsp[-4].exp, yyvsp[-2].exp, yyvsp[0].exp);
	  }
    break;
case 3:
#line 163 "plural.y"
{
	    yyval.exp = new_exp_2 (lor, yyvsp[-2].exp, yyvsp[0].exp);
	  }
    break;
case 4:
#line 167 "plural.y"
{
	    yyval.exp = new_exp_2 (land, yyvsp[-2].exp, yyvsp[0].exp);
	  }
    break;
case 5:
#line 171 "plural.y"
{
	    yyval.exp = new_exp_2 (yyvsp[-1].op, yyvsp[-2].exp, yyvsp[0].exp);
	  }
    break;
case 6:
#line 175 "plural.y"
{
	    yyval.exp = new_exp_2 (yyvsp[-1].op, yyvsp[-2].exp, yyvsp[0].exp);
	  }
    break;
case 7:
#line 179 "plural.y"
{
	    yyval.exp = new_exp_2 (yyvsp[-1].op, yyvsp[-2].exp, yyvsp[0].exp);
	  }
    break;
case 8:
#line 183 "plural.y"
{
	    yyval.exp = new_exp_2 (yyvsp[-1].op, yyvsp[-2].exp, yyvsp[0].exp);
	  }
    break;
case 9:
#line 187 "plural.y"
{
	    yyval.exp = new_exp_1 (lnot, yyvsp[0].exp);
	  }
    break;
case 10:
#line 191 "plural.y"
{
	    yyval.exp = new_exp_0 (var);
	  }
    break;
case 11:
#line 195 "plural.y"
{
	    if ((yyval.exp = new_exp_0 (num)) != NULL)
	      yyval.exp->val.num = yyvsp[0].num;
	  }
    break;
case 12:
#line 200 "plural.y"
{
	    yyval.exp = yyvsp[-1].exp;
	  }
    break;
}

#line 705 "/home/haible/gnu/arch/linuxlibc6/share/bison/bison.simple"


  yyvsp -= yylen;
  yyssp -= yylen;
#if YYLSP_NEEDED
  yylsp -= yylen;
#endif

#if YYDEBUG
  if (yydebug)
    {
      short *yyssp1 = yyss - 1;
      YYFPRINTF (stderr, "state stack now");
      while (yyssp1 != yyssp)
	YYFPRINTF (stderr, " %d", *++yyssp1);
      YYFPRINTF (stderr, "\n");
    }
#endif

  *++yyvsp = yyval;
#if YYLSP_NEEDED
  *++yylsp = yyloc;
#endif

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

  goto yynewstate;


/*------------------------------------.
| yyerrlab -- here on detecting error |
`------------------------------------*/
yyerrlab:
  /* If not already recovering from an error, report this error.  */
  if (!yyerrstatus)
    {
      ++yynerrs;

#ifdef YYERROR_VERBOSE
      yyn = yypact[yystate];

      if (yyn > YYFLAG && yyn < YYLAST)
	{
	  YYSIZE_T yysize = 0;
	  char *yymsg;
	  int yyx, yycount;

	  yycount = 0;
	  /* Start YYX at -YYN if negative to avoid negative indexes in
	     YYCHECK.  */
	  for (yyx = yyn < 0 ? -yyn : 0;
	       yyx < (int) (sizeof (yytname) / sizeof (char *)); yyx++)
	    if (yycheck[yyx + yyn] == yyx)
	      yysize += yystrlen (yytname[yyx]) + 15, yycount++;
	  yysize += yystrlen ("parse error, unexpected ") + 1;
	  yysize += yystrlen (yytname[YYTRANSLATE (yychar)]);
	  yymsg = (char *) YYSTACK_ALLOC (yysize);
	  if (yymsg != 0)
	    {
	      char *yyp = yystpcpy (yymsg, "parse error, unexpected ");
	      yyp = yystpcpy (yyp, yytname[YYTRANSLATE (yychar)]);

	      if (yycount < 5)
		{
		  yycount = 0;
		  for (yyx = yyn < 0 ? -yyn : 0;
		       yyx < (int) (sizeof (yytname) / sizeof (char *));
		       yyx++)
		    if (yycheck[yyx + yyn] == yyx)
		      {
			const char *yyq = ! yycount ? ", expecting " : " or ";
			yyp = yystpcpy (yyp, yyq);
			yyp = yystpcpy (yyp, yytname[yyx]);
			yycount++;
		      }
		}
	      yyerror (yymsg);
	      YYSTACK_FREE (yymsg);
	    }
	  else
	    yyerror ("parse error; also virtual memory exhausted");
	}
      else
#endif /* defined (YYERROR_VERBOSE) */
	yyerror ("parse error");
    }
  goto yyerrlab1;


/*--------------------------------------------------.
| yyerrlab1 -- error raised explicitly by an action |
`--------------------------------------------------*/
yyerrlab1:
  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)
	YYABORT;
      YYDPRINTF ((stderr, "Discarding token %d (%s).\n",
		  yychar, yytname[yychar1]));
      yychar = YYEMPTY;
    }

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

  yyerrstatus = 3;		/* Each real token shifted decrements this */

  goto yyerrhandle;


/*-------------------------------------------------------------------.
| yyerrdefault -- current state does not do anything special for the |
| error token.                                                       |
`-------------------------------------------------------------------*/
yyerrdefault:
#if 0
  /* This is wrong; only states that explicitly want error tokens
     should shift them.  */

  /* If its default is to accept any token, ok.  Otherwise pop it.  */
  yyn = yydefact[yystate];
  if (yyn)
    goto yydefault;
#endif


/*---------------------------------------------------------------.
| yyerrpop -- pop the current state because it cannot handle the |
| error token                                                    |
`---------------------------------------------------------------*/
yyerrpop:
  if (yyssp == yyss)
    YYABORT;
  yyvsp--;
  yystate = *--yyssp;
#if YYLSP_NEEDED
  yylsp--;
#endif

#if YYDEBUG
  if (yydebug)
    {
      short *yyssp1 = yyss - 1;
      YYFPRINTF (stderr, "Error: state stack now");
      while (yyssp1 != yyssp)
	YYFPRINTF (stderr, " %d", *++yyssp1);
      YYFPRINTF (stderr, "\n");
    }
#endif

/*--------------.
| yyerrhandle.  |
`--------------*/
yyerrhandle:
  yyn = yypact[yystate];
  if (yyn == YYFLAG)
    goto yyerrdefault;

  yyn += YYTERROR;
  if (yyn < 0 || yyn > YYLAST || yycheck[yyn] != YYTERROR)
    goto yyerrdefault;

  yyn = yytable[yyn];
  if (yyn < 0)
    {
      if (yyn == YYFLAG)
	goto yyerrpop;
      yyn = -yyn;
      goto yyreduce;
    }
  else if (yyn == 0)
    goto yyerrpop;

  if (yyn == YYFINAL)
    YYACCEPT;

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

  *++yyvsp = yylval;
#if YYLSP_NEEDED
  *++yylsp = yylloc;
#endif

  yystate = yyn;
  goto yynewstate;


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

/*-----------------------------------.
| yyabortlab -- YYABORT comes here.  |
`-----------------------------------*/
yyabortlab:
  yyresult = 1;
  goto yyreturn;

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

yyreturn:
#ifndef yyoverflow
  if (yyss != yyssa)
    YYSTACK_FREE (yyss);
#endif
  return yyresult;
}
#line 205 "plural.y"


void
internal_function
FREE_EXPRESSION (struct expression *exp)
{
  if (exp == NULL)
    return;

  /* Handle the recursive case.  */
  switch (exp->nargs)
    {
    case 3:
      FREE_EXPRESSION (exp->val.args[2]);
      /* FALLTHROUGH */
    case 2:
      FREE_EXPRESSION (exp->val.args[1]);
      /* FALLTHROUGH */
    case 1:
      FREE_EXPRESSION (exp->val.args[0]);
      /* FALLTHROUGH */
    default:
      break;
    }

  free (exp);
}


static int
yylex (YYSTYPE *lval, const char **pexp)
{
  const char *exp = *pexp;
  int result;

  while (1)
    {
      if (exp[0] == '\0')
	{
	  *pexp = exp;
	  return YYEOF;
	}

      if (exp[0] != ' ' && exp[0] != '\t')
	break;

      ++exp;
    }

  result = *exp++;
  switch (result)
    {
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9':
      {
	unsigned long int n = result - '0';
	while (exp[0] >= '0' && exp[0] <= '9')
	  {
	    n *= 10;
	    n += exp[0] - '0';
	    ++exp;
	  }
	lval->num = n;
	result = NUMBER;
      }
      break;

    case '=':
      if (exp[0] == '=')
	{
	  ++exp;
	  lval->op = equal;
	  result = EQUOP2;
	}
      else
	result = YYERRCODE;
      break;

    case '!':
      if (exp[0] == '=')
	{
	  ++exp;
	  lval->op = not_equal;
	  result = EQUOP2;
	}
      break;

    case '&':
    case '|':
      if (exp[0] == result)
	++exp;
      else
	result = YYERRCODE;
      break;

    case '<':
      if (exp[0] == '=')
	{
	  ++exp;
	  lval->op = less_or_equal;
	}
      else
	lval->op = less_than;
      result = CMPOP2;
      break;

    case '>':
      if (exp[0] == '=')
	{
	  ++exp;
	  lval->op = greater_or_equal;
	}
      else
	lval->op = greater_than;
      result = CMPOP2;
      break;

    case '*':
      lval->op = mult;
      result = MULOP2;
      break;

    case '/':
      lval->op = divide;
      result = MULOP2;
      break;

    case '%':
      lval->op = module;
      result = MULOP2;
      break;

    case '+':
      lval->op = plus;
      result = ADDOP2;
      break;

    case '-':
      lval->op = minus;
      result = ADDOP2;
      break;

    case 'n':
    case '?':
    case ':':
    case '(':
    case ')':
      /* Nothing, just return the character.  */
      break;

    case ';':
    case '\n':
    case '\0':
      /* Be safe and let the user call this function again.  */
      --exp;
      result = YYEOF;
      break;

    default:
      result = YYERRCODE;
#if YYDEBUG != 0
      --exp;
#endif
      break;
    }

  *pexp = exp;

  return result;
}


static void
yyerror (const char *str)
{
  /* Do nothing.  We don't print error messages here.  */
}