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 <cassert>
  18 #include <fcntl.h>
  19 #include <sys/stat.h>
  20 #include <unistd.h>
  21
  22 static int savedStdHandleAutoConversionMode[3] = {-1, -1, -1};
  23
  24 int disableAutoConversion(int FD) {
  25   static const struct f_cnvrt Convert = {
  26       SETCVTOFF, // cvtcmd
  27       0,         // pccsid
  28       0,         // fccsid
  29   };
  30
  31   return fcntl(FD, F_CONTROL_CVT, &Convert);
  32 }
  33
  34 int restoreStdHandleAutoConversion(int FD) {
  35   assert(FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO);
  36   if (savedStdHandleAutoConversionMode[FD] == -1)
  37     return 0;
  38   struct f_cnvrt Cvt = {
  39       savedStdHandleAutoConversionMode[FD], // cvtcmd
  40       0,                                    // pccsid
  41       0,                                    // fccsid
  42   };
  43   return (fcntl(FD, F_CONTROL_CVT, &Cvt));
  44 }
  45
  46 int enableAutoConversion(int FD) {
  47   struct f_cnvrt Query = {
  48       QUERYCVT, // cvtcmd
  49       0,        // pccsid
  50       0,        // fccsid
  51   };
  52
  53   if (fcntl(FD, F_CONTROL_CVT, &Query) == -1)
  54     return -1;
  55
  56   // We don't need conversion for UTF-8 tagged files.
  57   // TODO: Remove the assumption of ISO8859-1 = UTF-8 here when we fully resolve
  58   // problems related to UTF-8 tagged source files.
  59   // When the pccsid is not ISO8859-1, autoconversion is still needed.
  60   if (Query.pccsid == CCSID_ISO8859_1 &&
  61       (Query.fccsid == CCSID_UTF_8 || Query.fccsid == CCSID_ISO8859_1))
  62     return 0;
  63
  64   // Save the state of std handles before we make changes to it.
  65   if ((FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO) &&
  66       savedStdHandleAutoConversionMode[FD] == -1)
  67     savedStdHandleAutoConversionMode[FD] = Query.cvtcmd;
  68
  69   if (FD == STDOUT_FILENO || FD == STDERR_FILENO)
  70     Query.cvtcmd = SETCVTON;
  71   else
  72     Query.cvtcmd = SETCVTALL;
  73
  74   Query.pccsid =
  75       (FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO)
  76           ? 0
  77           : CCSID_UTF_8;
  78   // Assume untagged files to be IBM-1047 encoded.
  79   Query.fccsid = (Query.fccsid == FT_UNTAGGED) ? CCSID_IBM_1047 : Query.fccsid;
  80   return fcntl(FD, F_CONTROL_CVT, &Query);
  81 }
  82
  83 std::error_code llvm::disableAutoConversion(int FD) {
  84   if (::disableAutoConversion(FD) == -1)
  85     return std::error_code(errno, std::generic_category());
  86
  87   return std::error_code();
  88 }
  89
  90 std::error_code llvm::enableAutoConversion(int FD) {
  91   if (::enableAutoConversion(FD) == -1)
  92     return std::error_code(errno, std::generic_category());
  93
  94   return std::error_code();
  95 }
  96
  97 std::error_code llvm::restoreStdHandleAutoConversion(int FD) {
  98   if (::restoreStdHandleAutoConversion(FD) == -1)
  99     return std::error_code(errno, std::generic_category());
 100
 101   return std::error_code();
 102 }
 103
 104 std::error_code llvm::setFileTag(int FD, int CCSID, bool Text) {
 105   assert((!Text || (CCSID != FT_UNTAGGED && CCSID != FT_BINARY)) &&
 106          "FT_UNTAGGED and FT_BINARY are not allowed for text files");
 107   struct file_tag Tag;
 108   Tag.ft_ccsid = CCSID;
 109   Tag.ft_txtflag = Text;
 110   Tag.ft_deferred = 0;
 111   Tag.ft_rsvflags = 0;
 112
 113   if (fcntl(FD, F_SETTAG, &Tag) == -1)
 114     return std::error_code(errno, std::generic_category());
 115   return std::error_code();
 116 }
 117
 118 #endif // __MVS__