1 /* Styling for ui_file 2 Copyright (C) 2018-2019 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 "defs.h" 20 #include "ui-style.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 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 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 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 171 read_semi_number (const char *string, int *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 188 extended_color (const char *str, int *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 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 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 407 _initialize_ui_style () 408 { 409 int code = regcomp (&ansi_regex, ansi_regex_text, REG_EXTENDED); 410 /* If the regular expression was incorrect, it was a programming 411 error. */ 412 gdb_assert (code == 0); 413 } 414