llvm/lib/Support/AutoConvert.cpp

   1 //===- AutoConvert.cpp - Auto conversion between ASCII/EBCDIC -------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains functions used for auto conversion between
  10 // ASCII/EBCDIC codepages specific to z/OS.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifdef __MVS__
  15
  16 #include "llvm/Support/AutoConvert.h"
  17 #include "llvm/Support/Error.h"
  18 #include <cassert>
  19 #include <fcntl.h>
  20 #include <sys/stat.h>
  21 #include <unistd.h>
  22
  23 using namespace llvm;
  24
  25 static int savedStdHandleAutoConversionMode[3] = {-1, -1, -1};
  26
  27 int disablezOSAutoConversion(int FD) {
  28   static const struct f_cnvrt Convert = {
  29       SETCVTOFF, // cvtcmd
  30       0,         // pccsid
  31       0,         // fccsid
  32   };
  33
  34   return fcntl(FD, F_CONTROL_CVT, &Convert);
  35 }
  36
  37 int restorezOSStdHandleAutoConversion(int FD) {
  38   assert(FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO);
  39   if (savedStdHandleAutoConversionMode[FD] == -1)
  40     return 0;
  41   struct f_cnvrt Cvt = {
  42       savedStdHandleAutoConversionMode[FD], // cvtcmd
  43       0,                                    // pccsid
  44       0,                                    // fccsid
  45   };
  46   return (fcntl(FD, F_CONTROL_CVT, &Cvt));
  47 }
  48
  49 int enablezOSAutoConversion(int FD) {
  50   struct f_cnvrt Query = {
  51       QUERYCVT, // cvtcmd
  52       0,        // pccsid
  53       0,        // fccsid
  54   };
  55
  56   if (fcntl(FD, F_CONTROL_CVT, &Query) == -1)
  57     return -1;
  58
  59   // We don't need conversion for UTF-8 tagged files.
  60   // TODO: Remove the assumption of ISO8859-1 = UTF-8 here when we fully resolve
  61   // problems related to UTF-8 tagged source files.
  62   // When the pccsid is not ISO8859-1, autoconversion is still needed.
  63   if (Query.pccsid == CCSID_ISO8859_1 &&
  64       (Query.fccsid == CCSID_UTF_8 || Query.fccsid == CCSID_ISO8859_1))
  65     return 0;
  66
  67   // Save the state of std handles before we make changes to it.
  68   if ((FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO) &&
  69       savedStdHandleAutoConversionMode[FD] == -1)
  70     savedStdHandleAutoConversionMode[FD] = Query.cvtcmd;
  71
  72   if (FD == STDOUT_FILENO || FD == STDERR_FILENO)
  73     Query.cvtcmd = SETCVTON;
  74   else
  75     Query.cvtcmd = SETCVTALL;
  76
  77   Query.pccsid =
  78       (FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO)
  79           ? 0
  80           : CCSID_UTF_8;
  81   // Assume untagged files to be IBM-1047 encoded.
  82   Query.fccsid = (Query.fccsid == FT_UNTAGGED) ? CCSID_IBM_1047 : Query.fccsid;
  83   return fcntl(FD, F_CONTROL_CVT, &Query);
  84 }
  85
  86 std::error_code llvm::disablezOSAutoConversion(int FD) {
  87   if (::disablezOSAutoConversion(FD) == -1)
  88     return errnoAsErrorCode();
  89
  90   return std::error_code();
  91 }
  92
  93 std::error_code llvm::enablezOSAutoConversion(int FD) {
  94   if (::enablezOSAutoConversion(FD) == -1)
  95     return errnoAsErrorCode();
  96
  97   return std::error_code();
  98 }
  99
 100 std::error_code llvm::restorezOSStdHandleAutoConversion(int FD) {
 101   if (::restorezOSStdHandleAutoConversion(FD) == -1)
 102     return errnoAsErrorCode();
 103
 104   return std::error_code();
 105 }
 106
 107 std::error_code llvm::setzOSFileTag(int FD, int CCSID, bool Text) {
 108   assert((!Text || (CCSID != FT_UNTAGGED && CCSID != FT_BINARY)) &&
 109          "FT_UNTAGGED and FT_BINARY are not allowed for text files");
 110   struct file_tag Tag;
 111   Tag.ft_ccsid = CCSID;
 112   Tag.ft_txtflag = Text;
 113   Tag.ft_deferred = 0;
 114   Tag.ft_rsvflags = 0;
 115
 116   if (fcntl(FD, F_SETTAG, &Tag) == -1)
 117     return errnoAsErrorCode();
 118   return std::error_code();
 119 }
 120
 121 ErrorOr<__ccsid_t> llvm::getzOSFileTag(const char *FileName, const int FD) {
 122   // If we have a file descriptor, use it to find out file tagging. Otherwise we
 123   // need to use stat() with the file path.
 124   if (FD != -1) {
 125     struct f_cnvrt Query = {
 126         QUERYCVT, // cvtcmd
 127         0,        // pccsid
 128         0,        // fccsid
 129     };
 130     if (fcntl(FD, F_CONTROL_CVT, &Query) == -1)
 131       return std::error_code(errno, std::generic_category());
 132     return Query.fccsid;
 133   }
 134   struct stat Attr;
 135   if (stat(FileName, &Attr) == -1)
 136     return std::error_code(errno, std::generic_category());
 137   return Attr.st_tag.ft_ccsid;
 138 }
 139
 140 ErrorOr<bool> llvm::needzOSConversion(const char *FileName, const int FD) {
 141   ErrorOr<__ccsid_t> Ccsid = getzOSFileTag(FileName, FD);
 142   if (std::error_code EC = Ccsid.getError())
 143     return EC;
 144   // We don't need conversion for UTF-8 tagged files or binary files.
 145   // TODO: Remove the assumption of ISO8859-1 = UTF-8 here when we fully resolve
 146   // problems related to UTF-8 tagged source files.
 147   switch (*Ccsid) {
 148   case CCSID_UTF_8:
 149   case CCSID_ISO8859_1:
 150   case FT_BINARY:
 151     return false;
 152   default:
 153     return true;
 154   }
 155 }
 156
 157 #endif //__MVS__