1 /* Styling for ui_file
2 Copyright (C) 2018-2024 Free Software Foundation, Inc.
3
4 This file is part of GDB.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18
19 #include "ui-style.h"
20 #include "gdbsupport/gdb_regex.h"
21
22 /* A regular expression that is used for matching ANSI terminal escape
23 sequences. */
24
25 static const char ansi_regex_text[] =
26 /* Introduction. */
27 "^\033\\["
28 #define DATA_SUBEXP 1
29 /* Capture parameter and intermediate bytes. */
30 "("
31 /* Parameter bytes. */
32 "[\x30-\x3f]*"
33 /* Intermediate bytes. */
34 "[\x20-\x2f]*"
35 /* End the first capture. */
36 ")"
37 /* The final byte. */
38 #define FINAL_SUBEXP 2
39 "([\x40-\x7e])";
40
41 /* The number of subexpressions to allocate space for, including the
42 "0th" whole match subexpression. */
43 #define NUM_SUBEXPRESSIONS 3
44
45 /* The compiled form of ansi_regex_text. */
46
47 static regex_t ansi_regex;
48
49 /* This maps bright colors to RGB triples. The index is the bright
50 color index, starting with bright black. The values come from
51 xterm. */
52
53 static const uint8_t bright_colors[][3] = {
54 { 127, 127, 127 }, /* Black. */
55 { 255, 0, 0 }, /* Red. */
56 { 0, 255, 0 }, /* Green. */
57 { 255, 255, 0 }, /* Yellow. */
58 { 92, 92, 255 }, /* Blue. */
59 { 255, 0, 255 }, /* Magenta. */
60 { 0, 255, 255 }, /* Cyan. */
61 { 255, 255, 255 } /* White. */
62 };
63
64 /* See ui-style.h. */
65
66 bool
append_ansi(bool is_fg,std::string * str)67 ui_file_style::color::append_ansi (bool is_fg, std::string *str) const
68 {
69 if (m_simple)
70 {
71 if (m_value >= BLACK && m_value <= WHITE)
72 str->append (std::to_string (m_value + (is_fg ? 30 : 40)));
73 else if (m_value > WHITE && m_value <= WHITE + 8)
74 str->append (std::to_string (m_value - WHITE + (is_fg ? 90 : 100)));
75 else if (m_value != -1)
76 {
77 str->append (is_fg ? "38;5;" : "48;5;");
78 str->append (std::to_string (m_value));
79 }
80 else
81 return false;
82 }
83 else
84 {
85 str->append (is_fg ? "38;2;" : "48;2;");
86 str->append (std::to_string (m_red)
87 + ";" + std::to_string (m_green)
88 + ";" + std::to_string (m_blue));
89 }
90 return true;
91 }
92
93 /* See ui-style.h. */
94
95 void
get_rgb(uint8_t * rgb)96 ui_file_style::color::get_rgb (uint8_t *rgb) const
97 {
98 if (m_simple)
99 {
100 /* Can't call this for a basic color or NONE -- those will end
101 up in the assert below. */
102 if (m_value >= 8 && m_value <= 15)
103 memcpy (rgb, bright_colors[m_value - 8], 3 * sizeof (uint8_t));
104 else if (m_value >= 16 && m_value <= 231)
105 {
106 int value = m_value;
107 value -= 16;
108 /* This obscure formula seems to be what terminals actually
109 do. */
110 int component = value / 36;
111 rgb[0] = component == 0 ? 0 : (55 + component * 40);
112 value %= 36;
113 component = value / 6;
114 rgb[1] = component == 0 ? 0 : (55 + component * 40);
115 value %= 6;
116 rgb[2] = value == 0 ? 0 : (55 + value * 40);
117 }
118 else if (m_value >= 232)
119 {
120 uint8_t v = (m_value - 232) * 10 + 8;
121 rgb[0] = v;
122 rgb[1] = v;
123 rgb[2] = v;
124 }
125 else
126 gdb_assert_not_reached ("get_rgb called on invalid color");
127 }
128 else
129 {
130 rgb[0] = m_red;
131 rgb[1] = m_green;
132 rgb[2] = m_blue;
133 }
134 }
135
136 /* See ui-style.h. */
137
138 std::string
to_ansi()139 ui_file_style::to_ansi () const
140 {
141 std::string result ("\033[");
142 bool need_semi = m_foreground.append_ansi (true, &result);
143 if (!m_background.is_none ())
144 {
145 if (need_semi)
146 result.push_back (';');
147 m_background.append_ansi (false, &result);
148 need_semi = true;
149 }
150 if (m_intensity != NORMAL)
151 {
152 if (need_semi)
153 result.push_back (';');
154 result.append (std::to_string (m_intensity));
155 need_semi = true;
156 }
157 if (m_reverse)
158 {
159 if (need_semi)
160 result.push_back (';');
161 result.push_back ('7');
162 }
163 result.push_back ('m');
164 return result;
165 }
166
167 /* Read a ";" and a number from STRING. Return the number of
168 characters read and put the number into *NUM. */
169
170 static bool
read_semi_number(const char * string,regoff_t * idx,long * num)171 read_semi_number (const char *string, regoff_t *idx, long *num)
172 {
173 if (string[*idx] != ';')
174 return false;
175 ++*idx;
176 if (string[*idx] < '0' || string[*idx] > '9')
177 return false;
178 char *tail;
179 *num = strtol (string + *idx, &tail, 10);
180 *idx = tail - string;
181 return true;
182 }
183
184 /* A helper for ui_file_style::parse that reads an extended color
185 sequence; that is, and 8- or 24- bit color. */
186
187 static bool
extended_color(const char * str,regoff_t * idx,ui_file_style::color * color)188 extended_color (const char *str, regoff_t *idx, ui_file_style::color *color)
189 {
190 long value;
191
192 if (!read_semi_number (str, idx, &value))
193 return false;
194
195 if (value == 5)
196 {
197 /* 8-bit color. */
198 if (!read_semi_number (str, idx, &value))
199 return false;
200
201 if (value >= 0 && value <= 255)
202 *color = ui_file_style::color (value);
203 else
204 return false;
205 }
206 else if (value == 2)
207 {
208 /* 24-bit color. */
209 long r, g, b;
210 if (!read_semi_number (str, idx, &r)
211 || r > 255
212 || !read_semi_number (str, idx, &g)
213 || g > 255
214 || !read_semi_number (str, idx, &b)
215 || b > 255)
216 return false;
217 *color = ui_file_style::color (r, g, b);
218 }
219 else
220 {
221 /* Unrecognized sequence. */
222 return false;
223 }
224
225 return true;
226 }
227
228 /* See ui-style.h. */
229
230 bool
parse(const char * buf,size_t * n_read)231 ui_file_style::parse (const char *buf, size_t *n_read)
232 {
233 regmatch_t subexps[NUM_SUBEXPRESSIONS];
234
235 int match = regexec (&ansi_regex, buf, ARRAY_SIZE (subexps), subexps, 0);
236 if (match == REG_NOMATCH)
237 {
238 *n_read = 0;
239 return false;
240 }
241 /* Other failures mean the regexp is broken. */
242 gdb_assert (match == 0);
243 /* The regexp is anchored. */
244 gdb_assert (subexps[0].rm_so == 0);
245 /* The final character exists. */
246 gdb_assert (subexps[FINAL_SUBEXP].rm_eo - subexps[FINAL_SUBEXP].rm_so == 1);
247
248 if (buf[subexps[FINAL_SUBEXP].rm_so] != 'm')
249 {
250 /* We don't handle this sequence, so just drop it. */
251 *n_read = subexps[0].rm_eo;
252 return false;
253 }
254
255 /* Examine each setting in the match and apply it to the result.
256 See the Select Graphic Rendition section of
257 https://en.wikipedia.org/wiki/ANSI_escape_code. In essence each
258 code is just a number, separated by ";"; there are some more
259 wrinkles but we don't support them all.. */
260
261 /* "\033[m" means the same thing as "\033[0m", so handle that
262 specially here. */
263 if (subexps[DATA_SUBEXP].rm_so == subexps[DATA_SUBEXP].rm_eo)
264 *this = ui_file_style ();
265
266 for (regoff_t i = subexps[DATA_SUBEXP].rm_so;
267 i < subexps[DATA_SUBEXP].rm_eo;
268 ++i)
269 {
270 if (buf[i] == ';')
271 {
272 /* Skip. */
273 }
274 else if (buf[i] >= '0' && buf[i] <= '9')
275 {
276 char *tail;
277 long value = strtol (buf + i, &tail, 10);
278 i = tail - buf;
279
280 switch (value)
281 {
282 case 0:
283 /* Reset. */
284 *this = ui_file_style ();
285 break;
286 case 1:
287 /* Bold. */
288 m_intensity = BOLD;
289 break;
290 case 2:
291 /* Dim. */
292 m_intensity = DIM;
293 break;
294 case 7:
295 /* Reverse. */
296 m_reverse = true;
297 break;
298 case 21:
299 m_intensity = NORMAL;
300 break;
301 case 22:
302 /* Normal. */
303 m_intensity = NORMAL;
304 break;
305 case 27:
306 /* Inverse off. */
307 m_reverse = false;
308 break;
309
310 case 30:
311 case 31:
312 case 32:
313 case 33:
314 case 34:
315 case 35:
316 case 36:
317 case 37:
318 /* Note: not 38. */
319 case 39:
320 m_foreground = color (value - 30);
321 break;
322
323 case 40:
324 case 41:
325 case 42:
326 case 43:
327 case 44:
328 case 45:
329 case 46:
330 case 47:
331 /* Note: not 48. */
332 case 49:
333 m_background = color (value - 40);
334 break;
335
336 case 90:
337 case 91:
338 case 92:
339 case 93:
340 case 94:
341 case 95:
342 case 96:
343 case 97:
344 m_foreground = color (value - 90 + 8);
345 break;
346
347 case 100:
348 case 101:
349 case 102:
350 case 103:
351 case 104:
352 case 105:
353 case 106:
354 case 107:
355 m_background = color (value - 100 + 8);
356 break;
357
358 case 38:
359 /* If we can't parse the extended color, fail. */
360 if (!extended_color (buf, &i, &m_foreground))
361 {
362 *n_read = subexps[0].rm_eo;
363 return false;
364 }
365 break;
366
367 case 48:
368 /* If we can't parse the extended color, fail. */
369 if (!extended_color (buf, &i, &m_background))
370 {
371 *n_read = subexps[0].rm_eo;
372 return false;
373 }
374 break;
375
376 default:
377 /* Ignore everything else. */
378 break;
379 }
380 }
381 else
382 {
383 /* Unknown, let's just ignore. */
384 }
385 }
386
387 *n_read = subexps[0].rm_eo;
388 return true;
389 }
390
391 /* See ui-style.h. */
392
393 bool
skip_ansi_escape(const char * buf,int * n_read)394 skip_ansi_escape (const char *buf, int *n_read)
395 {
396 regmatch_t subexps[NUM_SUBEXPRESSIONS];
397
398 int match = regexec (&ansi_regex, buf, ARRAY_SIZE (subexps), subexps, 0);
399 if (match == REG_NOMATCH || buf[subexps[FINAL_SUBEXP].rm_so] != 'm')
400 return false;
401
402 *n_read = subexps[FINAL_SUBEXP].rm_eo;
403 return true;
404 }
405
406 void _initialize_ui_style ();
407 void
_initialize_ui_style()408 _initialize_ui_style ()
409 {
410 int code = regcomp (&ansi_regex, ansi_regex_text, REG_EXTENDED);
411 /* If the regular expression was incorrect, it was a programming
412 error. */
413 gdb_assert (code == 0);
414 }
415