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
23static int savedStdHandleAutoConversionMode[3] = {-1, -1, -1};
24
25int 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
35int 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
47int 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
84std::error_code llvm::disableAutoConversion(int FD) {
85 if (::disableAutoConversion(FD) == -1)
86 return errnoAsErrorCode();
87
88 return std::error_code();
89}
90
91std::error_code llvm::enableAutoConversion(int FD) {
92 if (::enableAutoConversion(FD) == -1)
93 return errnoAsErrorCode();
94
95 return std::error_code();
96}
97
98std::error_code llvm::restoreStdHandleAutoConversion(int FD) {
99 if (::restoreStdHandleAutoConversion(FD) == -1)
100 return errnoAsErrorCode();
101
102 return std::error_code();
103}
104
105std::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__
120