xref: /freebsd/contrib/llvm-project/llvm/lib/Support/AutoConvert.cpp (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
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__
119