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 static int savedStdHandleAutoConversionMode[3] = {-1, -1, -1};
  24
  25 int disableAutoConversion(int FD) {
  26   static const struct f_cnvrt Convert = {
  27       SETCVTOFF, // cvtcmd
  28       0,         // pccsid
  29       0,         // fccsid
  30   };
  31
  32   return fcntl(FD, F_CONTROL_CVT, &Convert);
  33 }
  34
  35 int restoreStdHandleAutoConversion(int FD) {
  36   assert(FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO);
  37   if (savedStdHandleAutoConversionMode[FD] == -1)
  38     return 0;
  39   struct f_cnvrt Cvt = {
  40       savedStdHandleAutoConversionMode[FD], // cvtcmd
  41       0,                                    // pccsid
  42       0,                                    // fccsid
  43   };
  44   return (fcntl(FD, F_CONTROL_CVT, &Cvt));
  45 }
  46
  47 int enableAutoConversion(int FD) {
  48   struct f_cnvrt Query = {
  49       QUERYCVT, // cvtcmd
  50       0,        // pccsid
  51       0,        // fccsid
  52   };
  53
  54   if (fcntl(FD, F_CONTROL_CVT, &Query) == -1)
  55     return -1;
  56
  57   // We don't need conversion for UTF-8 tagged files.
  58   // TODO: Remove the assumption of ISO8859-1 = UTF-8 here when we fully resolve
  59   // problems related to UTF-8 tagged source files.
  60   // When the pccsid is not ISO8859-1, autoconversion is still needed.
  61   if (Query.pccsid == CCSID_ISO8859_1 &&
  62       (Query.fccsid == CCSID_UTF_8 || Query.fccsid == CCSID_ISO8859_1))
  63     return 0;
  64
  65   // Save the state of std handles before we make changes to it.
  66   if ((FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO) &&
  67       savedStdHandleAutoConversionMode[FD] == -1)
  68     savedStdHandleAutoConversionMode[FD] = Query.cvtcmd;
  69
  70   if (FD == STDOUT_FILENO || FD == STDERR_FILENO)
  71     Query.cvtcmd = SETCVTON;
  72   else
  73     Query.cvtcmd = SETCVTALL;
  74
  75   Query.pccsid =
  76       (FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO)
  77           ? 0
  78           : CCSID_UTF_8;
  79   // Assume untagged files to be IBM-1047 encoded.
  80   Query.fccsid = (Query.fccsid == FT_UNTAGGED) ? CCSID_IBM_1047 : Query.fccsid;
  81   return fcntl(FD, F_CONTROL_CVT, &Query);
  82 }
  83
  84 std::error_code llvm::disableAutoConversion(int FD) {
  85   if (::disableAutoConversion(FD) == -1)
  86     return errnoAsErrorCode();
  87
  88   return std::error_code();
  89 }
  90
  91 std::error_code llvm::enableAutoConversion(int FD) {
  92   if (::enableAutoConversion(FD) == -1)
  93     return errnoAsErrorCode();
  94
  95   return std::error_code();
  96 }
  97
  98 std::error_code llvm::restoreStdHandleAutoConversion(int FD) {
  99   if (::restoreStdHandleAutoConversion(FD) == -1)
 100     return errnoAsErrorCode();
 101
 102   return std::error_code();
 103 }
 104
 105 std::error_code llvm::setFileTag(int FD, int CCSID, bool Text) {
 106   assert((!Text || (CCSID != FT_UNTAGGED && CCSID != FT_BINARY)) &&
 107          "FT_UNTAGGED and FT_BINARY are not allowed for text files");
 108   struct file_tag Tag;
 109   Tag.ft_ccsid = CCSID;
 110   Tag.ft_txtflag = Text;
 111   Tag.ft_deferred = 0;
 112   Tag.ft_rsvflags = 0;
 113
 114   if (fcntl(FD, F_SETTAG, &Tag) == -1)
 115     return errnoAsErrorCode();
 116   return std::error_code();
 117 }
 118
 119 #endif // __MVS__