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
22using namespace llvm;
23
24static int savedStdHandleAutoConversionMode[3] = {-1, -1, -1};
25
26int disablezOSAutoConversion(int FD) {
27 static const struct f_cnvrt Convert = {
28 SETCVTOFF, // cvtcmd
29 0, // pccsid
30 0, // fccsid
31 };
32
33 return fcntl(FD, F_CONTROL_CVT, &Convert);
34}
35
36int restorezOSStdHandleAutoConversion(int FD) {
37 assert(FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO);
38 if (savedStdHandleAutoConversionMode[FD] == -1)
39 return 0;
40 struct f_cnvrt Cvt = {
41 savedStdHandleAutoConversionMode[FD], // cvtcmd
42 0, // pccsid
43 0, // fccsid
44 };
45 return (fcntl(FD, F_CONTROL_CVT, &Cvt));
46}
47
48int enablezOSAutoConversion(int FD) {
49 struct f_cnvrt Query = {
50 QUERYCVT, // cvtcmd
51 0, // pccsid
52 0, // fccsid
53 };
54
55 if (fcntl(FD, F_CONTROL_CVT, &Query) == -1)
56 return -1;
57
58 // We don't need conversion for UTF-8 tagged files.
59 // TODO: Remove the assumption of ISO8859-1 = UTF-8 here when we fully resolve
60 // problems related to UTF-8 tagged source files.
61 // When the pccsid is not ISO8859-1, autoconversion is still needed.
62 if (Query.pccsid == CCSID_ISO8859_1 &&
63 (Query.fccsid == CCSID_UTF_8 || Query.fccsid == CCSID_ISO8859_1))
64 return 0;
65
66 // Save the state of std handles before we make changes to it.
67 if ((FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO) &&
68 savedStdHandleAutoConversionMode[FD] == -1)
69 savedStdHandleAutoConversionMode[FD] = Query.cvtcmd;
70
71 if (FD == STDOUT_FILENO || FD == STDERR_FILENO)
72 Query.cvtcmd = SETCVTON;
73 else
74 Query.cvtcmd = SETCVTALL;
75
76 Query.pccsid =
77 (FD == STDIN_FILENO || FD == STDOUT_FILENO || FD == STDERR_FILENO)
78 ? 0
79 : CCSID_UTF_8;
80 // Assume untagged files to be IBM-1047 encoded.
81 Query.fccsid = (Query.fccsid == FT_UNTAGGED) ? CCSID_IBM_1047 : Query.fccsid;
82 return fcntl(FD, F_CONTROL_CVT, &Query);
83}
84
85std::error_code llvm::setzOSFileTag(int FD, int CCSID, bool Text) {
86 assert((!Text || (CCSID != FT_UNTAGGED && CCSID != FT_BINARY)) &&
87 "FT_UNTAGGED and FT_BINARY are not allowed for text files");
88 struct file_tag Tag;
89 Tag.ft_ccsid = CCSID;
90 Tag.ft_txtflag = Text;
91 Tag.ft_deferred = 0;
92 Tag.ft_rsvflags = 0;
93
94 if (fcntl(FD, F_SETTAG, &Tag) == -1)
95 return errnoAsErrorCode();
96 return std::error_code();
97}
98
99ErrorOr<__ccsid_t> llvm::getzOSFileTag(const char *FileName, const int FD) {
100 // If we have a file descriptor, use it to find out file tagging. Otherwise we
101 // need to use stat() with the file path.
102 if (FD != -1) {
103 struct f_cnvrt Query = {
104 QUERYCVT, // cvtcmd
105 0, // pccsid
106 0, // fccsid
107 };
108 if (fcntl(FD, F_CONTROL_CVT, &Query) == -1)
109 return std::error_code(errno, std::generic_category());
110 return Query.fccsid;
111 }
112 struct stat Attr;
113 if (stat(FileName, &Attr) == -1)
114 return std::error_code(errno, std::generic_category());
115 return Attr.st_tag.ft_ccsid;
116}
117
118ErrorOr<bool> llvm::needzOSConversion(const char *FileName, const int FD) {
119 ErrorOr<__ccsid_t> Ccsid = getzOSFileTag(FileName, FD);
120 if (std::error_code EC = Ccsid.getError())
121 return EC;
122 // We don't need conversion for UTF-8 tagged files or binary files.
123 // TODO: Remove the assumption of ISO8859-1 = UTF-8 here when we fully resolve
124 // problems related to UTF-8 tagged source files.
125 switch (*Ccsid) {
126 case CCSID_UTF_8:
127 case CCSID_ISO8859_1:
128 case FT_BINARY:
129 return false;
130 default:
131 return true;
132 }
133}
134
135#endif //__MVS__
136