1 #include "vterm_internal.h"
2
3 #define UNICODE_INVALID 0xFFFD
4
5 #if defined(DEBUG) && DEBUG > 1
6 # define DEBUG_PRINT_UTF8
7 #endif
8
9 struct UTF8DecoderData {
10 // number of bytes remaining in this codepoint
11 int bytes_remaining;
12
13 // number of bytes total in this codepoint once it's finished
14 // (for detecting overlongs)
15 int bytes_total;
16
17 int this_cp;
18 };
19
init_utf8(VTermEncoding * enc,void * data_)20 static void init_utf8(VTermEncoding *enc, void *data_)
21 {
22 struct UTF8DecoderData *data = data_;
23
24 data->bytes_remaining = 0;
25 data->bytes_total = 0;
26 }
27
decode_utf8(VTermEncoding * enc,void * data_,uint32_t cp[],int * cpi,int cplen,const char bytes[],size_t * pos,size_t bytelen)28 static void decode_utf8(VTermEncoding *enc, void *data_,
29 uint32_t cp[], int *cpi, int cplen,
30 const char bytes[], size_t *pos, size_t bytelen)
31 {
32 struct UTF8DecoderData *data = data_;
33
34 #ifdef DEBUG_PRINT_UTF8
35 printf("BEGIN UTF-8\n");
36 #endif
37
38 for(; *pos < bytelen && *cpi < cplen; (*pos)++) {
39 unsigned char c = bytes[*pos];
40
41 #ifdef DEBUG_PRINT_UTF8
42 printf(" pos=%zd c=%02x rem=%d\n", *pos, c, data->bytes_remaining);
43 #endif
44
45 if(c < 0x20)
46 return;
47
48 else if(c >= 0x20 && c < 0x80) {
49 if(data->bytes_remaining)
50 cp[(*cpi)++] = UNICODE_INVALID;
51
52 cp[(*cpi)++] = c;
53 #ifdef DEBUG_PRINT_UTF8
54 printf(" UTF-8 char: U+%04x\n", c);
55 #endif
56 data->bytes_remaining = 0;
57 }
58
59 else if(c >= 0x80 && c < 0xc0) {
60 if(!data->bytes_remaining) {
61 cp[(*cpi)++] = UNICODE_INVALID;
62 continue;
63 }
64
65 data->this_cp <<= 6;
66 data->this_cp |= c & 0x3f;
67 data->bytes_remaining--;
68
69 if(!data->bytes_remaining) {
70 #ifdef DEBUG_PRINT_UTF8
71 printf(" UTF-8 raw char U+%04x bytelen=%d ", data->this_cp, data->bytes_total);
72 #endif
73 // Check for overlong sequences
74 switch(data->bytes_total) {
75 case 2:
76 if(data->this_cp < 0x0080) data->this_cp = UNICODE_INVALID; break;
77 case 3:
78 if(data->this_cp < 0x0800) data->this_cp = UNICODE_INVALID; break;
79 case 4:
80 if(data->this_cp < 0x10000) data->this_cp = UNICODE_INVALID; break;
81 case 5:
82 if(data->this_cp < 0x200000) data->this_cp = UNICODE_INVALID; break;
83 case 6:
84 if(data->this_cp < 0x4000000) data->this_cp = UNICODE_INVALID; break;
85 }
86 // Now look for plain invalid ones
87 if((data->this_cp >= 0xD800 && data->this_cp <= 0xDFFF) ||
88 data->this_cp == 0xFFFE ||
89 data->this_cp == 0xFFFF)
90 data->this_cp = UNICODE_INVALID;
91 #ifdef DEBUG_PRINT_UTF8
92 printf(" char: U+%04x\n", data->this_cp);
93 #endif
94 cp[(*cpi)++] = data->this_cp;
95 }
96 }
97
98 else if(c >= 0xc0 && c < 0xe0) {
99 if(data->bytes_remaining)
100 cp[(*cpi)++] = UNICODE_INVALID;
101
102 data->this_cp = c & 0x1f;
103 data->bytes_total = 2;
104 data->bytes_remaining = 1;
105 }
106
107 else if(c >= 0xe0 && c < 0xf0) {
108 if(data->bytes_remaining)
109 cp[(*cpi)++] = UNICODE_INVALID;
110
111 data->this_cp = c & 0x0f;
112 data->bytes_total = 3;
113 data->bytes_remaining = 2;
114 }
115
116 else if(c >= 0xf0 && c < 0xf8) {
117 if(data->bytes_remaining)
118 cp[(*cpi)++] = UNICODE_INVALID;
119
120 data->this_cp = c & 0x07;
121 data->bytes_total = 4;
122 data->bytes_remaining = 3;
123 }
124
125 else if(c >= 0xf8 && c < 0xfc) {
126 if(data->bytes_remaining)
127 cp[(*cpi)++] = UNICODE_INVALID;
128
129 data->this_cp = c & 0x03;
130 data->bytes_total = 5;
131 data->bytes_remaining = 4;
132 }
133
134 else if(c >= 0xfc && c < 0xfe) {
135 if(data->bytes_remaining)
136 cp[(*cpi)++] = UNICODE_INVALID;
137
138 data->this_cp = c & 0x01;
139 data->bytes_total = 6;
140 data->bytes_remaining = 5;
141 }
142
143 else {
144 cp[(*cpi)++] = UNICODE_INVALID;
145 }
146 }
147 }
148
149 static VTermEncoding encoding_utf8 = {
150 .init = &init_utf8,
151 .decode = &decode_utf8,
152 };
153
decode_usascii(VTermEncoding * enc,void * data,uint32_t cp[],int * cpi,int cplen,const char bytes[],size_t * pos,size_t bytelen)154 static void decode_usascii(VTermEncoding *enc, void *data,
155 uint32_t cp[], int *cpi, int cplen,
156 const char bytes[], size_t *pos, size_t bytelen)
157 {
158 int is_gr = bytes[*pos] & 0x80;
159
160 for(; *pos < bytelen && *cpi < cplen; (*pos)++) {
161 unsigned char c = bytes[*pos] ^ is_gr;
162
163 if(c < 0x20 || c >= 0x80)
164 return;
165
166 cp[(*cpi)++] = c;
167 }
168 }
169
170 static VTermEncoding encoding_usascii = {
171 .decode = &decode_usascii,
172 };
173
174 struct StaticTableEncoding {
175 const VTermEncoding enc;
176 const uint32_t chars[128];
177 };
178
decode_table(VTermEncoding * enc,void * data,uint32_t cp[],int * cpi,int cplen,const char bytes[],size_t * pos,size_t bytelen)179 static void decode_table(VTermEncoding *enc, void *data,
180 uint32_t cp[], int *cpi, int cplen,
181 const char bytes[], size_t *pos, size_t bytelen)
182 {
183 struct StaticTableEncoding *table = (struct StaticTableEncoding *)enc;
184 int is_gr = bytes[*pos] & 0x80;
185
186 for(; *pos < bytelen && *cpi < cplen; (*pos)++) {
187 unsigned char c = bytes[*pos] ^ is_gr;
188
189 if(c < 0x20 || c >= 0x80)
190 return;
191
192 if(table->chars[c])
193 cp[(*cpi)++] = table->chars[c];
194 else
195 cp[(*cpi)++] = c;
196 }
197 }
198
199 #include "encoding/DECdrawing.inc"
200 #include "encoding/uk.inc"
201
202 static struct {
203 VTermEncodingType type;
204 char designation;
205 VTermEncoding *enc;
206 }
207 encodings[] = {
208 { ENC_UTF8, 'u', &encoding_utf8 },
209 { ENC_SINGLE_94, '0', (VTermEncoding*)&encoding_DECdrawing },
210 { ENC_SINGLE_94, 'A', (VTermEncoding*)&encoding_uk },
211 { ENC_SINGLE_94, 'B', &encoding_usascii },
212 { 0 },
213 };
214
215 /* This ought to be INTERNAL but isn't because it's used by unit testing */
vterm_lookup_encoding(VTermEncodingType type,char designation)216 VTermEncoding *vterm_lookup_encoding(VTermEncodingType type, char designation)
217 {
218 for(int i = 0; encodings[i].designation; i++)
219 if(encodings[i].type == type && encodings[i].designation == designation)
220 return encodings[i].enc;
221 return NULL;
222 }
223