xref: /freebsd/contrib/llvm-project/llvm/lib/Support/ConvertEBCDIC.cpp (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 //===--- ConvertEBCDIC.cpp - UTF8/EBCDIC CharSet Conversion -----*- C++ -*-===//
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 /// \file
10 /// This file provides utility functions for converting between EBCDIC-1047 and
11 /// UTF-8.
12 ///
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #include "llvm/Support/ConvertEBCDIC.h"
17 
18 using namespace llvm;
19 
20 static const unsigned char ISO88591ToIBM1047[256] = {
21     0x00, 0x01, 0x02, 0x03, 0x37, 0x2d, 0x2e, 0x2f, 0x16, 0x05, 0x15, 0x0b,
22     0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x3c, 0x3d, 0x32, 0x26,
23     0x18, 0x19, 0x3f, 0x27, 0x1c, 0x1d, 0x1e, 0x1f, 0x40, 0x5a, 0x7f, 0x7b,
24     0x5b, 0x6c, 0x50, 0x7d, 0x4d, 0x5d, 0x5c, 0x4e, 0x6b, 0x60, 0x4b, 0x61,
25     0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0x7a, 0x5e,
26     0x4c, 0x7e, 0x6e, 0x6f, 0x7c, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
27     0xc8, 0xc9, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xe2,
28     0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xad, 0xe0, 0xbd, 0x5f, 0x6d,
29     0x79, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x91, 0x92,
30     0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6,
31     0xa7, 0xa8, 0xa9, 0xc0, 0x4f, 0xd0, 0xa1, 0x07, 0x20, 0x21, 0x22, 0x23,
32     0x24, 0x25, 0x06, 0x17, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x09, 0x0a, 0x1b,
33     0x30, 0x31, 0x1a, 0x33, 0x34, 0x35, 0x36, 0x08, 0x38, 0x39, 0x3a, 0x3b,
34     0x04, 0x14, 0x3e, 0xff, 0x41, 0xaa, 0x4a, 0xb1, 0x9f, 0xb2, 0x6a, 0xb5,
35     0xbb, 0xb4, 0x9a, 0x8a, 0xb0, 0xca, 0xaf, 0xbc, 0x90, 0x8f, 0xea, 0xfa,
36     0xbe, 0xa0, 0xb6, 0xb3, 0x9d, 0xda, 0x9b, 0x8b, 0xb7, 0xb8, 0xb9, 0xab,
37     0x64, 0x65, 0x62, 0x66, 0x63, 0x67, 0x9e, 0x68, 0x74, 0x71, 0x72, 0x73,
38     0x78, 0x75, 0x76, 0x77, 0xac, 0x69, 0xed, 0xee, 0xeb, 0xef, 0xec, 0xbf,
39     0x80, 0xfd, 0xfe, 0xfb, 0xfc, 0xba, 0xae, 0x59, 0x44, 0x45, 0x42, 0x46,
40     0x43, 0x47, 0x9c, 0x48, 0x54, 0x51, 0x52, 0x53, 0x58, 0x55, 0x56, 0x57,
41     0x8c, 0x49, 0xcd, 0xce, 0xcb, 0xcf, 0xcc, 0xe1, 0x70, 0xdd, 0xde, 0xdb,
42     0xdc, 0x8d, 0x8e, 0xdf};
43 
44 static const unsigned char IBM1047ToISO88591[256] = {
45     0x00, 0x01, 0x02, 0x03, 0x9c, 0x09, 0x86, 0x7f, 0x97, 0x8d, 0x8e, 0x0b,
46     0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x9d, 0x0a, 0x08, 0x87,
47     0x18, 0x19, 0x92, 0x8f, 0x1c, 0x1d, 0x1e, 0x1f, 0x80, 0x81, 0x82, 0x83,
48     0x84, 0x85, 0x17, 0x1b, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x05, 0x06, 0x07,
49     0x90, 0x91, 0x16, 0x93, 0x94, 0x95, 0x96, 0x04, 0x98, 0x99, 0x9a, 0x9b,
50     0x14, 0x15, 0x9e, 0x1a, 0x20, 0xa0, 0xe2, 0xe4, 0xe0, 0xe1, 0xe3, 0xe5,
51     0xe7, 0xf1, 0xa2, 0x2e, 0x3c, 0x28, 0x2b, 0x7c, 0x26, 0xe9, 0xea, 0xeb,
52     0xe8, 0xed, 0xee, 0xef, 0xec, 0xdf, 0x21, 0x24, 0x2a, 0x29, 0x3b, 0x5e,
53     0x2d, 0x2f, 0xc2, 0xc4, 0xc0, 0xc1, 0xc3, 0xc5, 0xc7, 0xd1, 0xa6, 0x2c,
54     0x25, 0x5f, 0x3e, 0x3f, 0xf8, 0xc9, 0xca, 0xcb, 0xc8, 0xcd, 0xce, 0xcf,
55     0xcc, 0x60, 0x3a, 0x23, 0x40, 0x27, 0x3d, 0x22, 0xd8, 0x61, 0x62, 0x63,
56     0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0xab, 0xbb, 0xf0, 0xfd, 0xfe, 0xb1,
57     0xb0, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0xaa, 0xba,
58     0xe6, 0xb8, 0xc6, 0xa4, 0xb5, 0x7e, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
59     0x79, 0x7a, 0xa1, 0xbf, 0xd0, 0x5b, 0xde, 0xae, 0xac, 0xa3, 0xa5, 0xb7,
60     0xa9, 0xa7, 0xb6, 0xbc, 0xbd, 0xbe, 0xdd, 0xa8, 0xaf, 0x5d, 0xb4, 0xd7,
61     0x7b, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0xad, 0xf4,
62     0xf6, 0xf2, 0xf3, 0xf5, 0x7d, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
63     0x51, 0x52, 0xb9, 0xfb, 0xfc, 0xf9, 0xfa, 0xff, 0x5c, 0xf7, 0x53, 0x54,
64     0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0xb2, 0xd4, 0xd6, 0xd2, 0xd3, 0xd5,
65     0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0xb3, 0xdb,
66     0xdc, 0xd9, 0xda, 0x9f};
67 
68 std::error_code
69 ConverterEBCDIC::convertToEBCDIC(StringRef Source,
70                                  SmallVectorImpl<char> &Result) {
71   assert(Result.empty() && "Result must be empty!");
72   const unsigned char *Table = ISO88591ToIBM1047;
73   const unsigned char *Ptr =
74       reinterpret_cast<const unsigned char *>(Source.data());
75   size_t Length = Source.size();
76   Result.reserve(Length);
77   while (Length--) {
78     unsigned char Ch = *Ptr++;
79     // Handle UTF-8 2-byte-sequences in input.
80     if (Ch >= 128) {
81       // Only two-byte sequences can be decoded.
82       if (Ch != 0xc2 && Ch != 0xc3)
83         return std::make_error_code(std::errc::illegal_byte_sequence);
84       // Is buffer truncated?
85       if (!Length)
86         return std::make_error_code(std::errc::invalid_argument);
87       unsigned char Ch2 = *Ptr++;
88       // Is second byte well-formed?
89       if ((Ch2 & 0xc0) != 0x80)
90         return std::make_error_code(std::errc::illegal_byte_sequence);
91       Ch = Ch2 | (Ch << 6);
92       Length--;
93     }
94     // Translate the character.
95     Ch = Table[Ch];
96     Result.push_back(static_cast<char>(Ch));
97   }
98   return std::error_code();
99 }
100 
101 void ConverterEBCDIC::convertToUTF8(StringRef Source,
102                                     SmallVectorImpl<char> &Result) {
103   assert(Result.empty() && "Result must be empty!");
104 
105   const unsigned char *Table = IBM1047ToISO88591;
106   const unsigned char *Ptr =
107       reinterpret_cast<const unsigned char *>(Source.data());
108   size_t Length = Source.size();
109   Result.reserve(Length);
110   while (Length--) {
111     unsigned char Ch = *Ptr++;
112     // Translate the character.
113     Ch = Table[Ch];
114     // Handle UTF-8 2-byte-sequences in output.
115     if (Ch >= 128) {
116       // First byte prefixed with either 0xc2 or 0xc3.
117       Result.push_back(static_cast<char>(0xc0 | (Ch >> 6)));
118       // Second byte is either the same as the ASCII byte or ASCII byte -64.
119       Ch = Ch & 0xbf;
120     }
121     Result.push_back(static_cast<char>(Ch));
122   }
123 }
124