| 1 | /* Parse a printf-style format string. |
| 2 | |
| 3 | Copyright (C) 1986-2020 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "common-defs.h" |
| 21 | #include "format.h" |
| 22 | |
| 23 | format_pieces::format_pieces (const char **arg, bool gdb_extensions) |
| 24 | { |
| 25 | const char *s; |
| 26 | const char *string; |
| 27 | const char *prev_start; |
| 28 | const char *percent_loc; |
| 29 | char *sub_start, *current_substring; |
| 30 | enum argclass this_argclass; |
| 31 | |
| 32 | s = *arg; |
| 33 | |
| 34 | if (gdb_extensions) |
| 35 | { |
| 36 | string = *arg; |
| 37 | *arg += strlen (*arg); |
| 38 | } |
| 39 | else |
| 40 | { |
| 41 | /* Parse the format-control string and copy it into the string STRING, |
| 42 | processing some kinds of escape sequence. */ |
| 43 | |
| 44 | char *f = (char *) alloca (strlen (s) + 1); |
| 45 | string = f; |
| 46 | |
| 47 | while ((gdb_extensions || *s != '"') && *s != '\0') |
| 48 | { |
| 49 | int c = *s++; |
| 50 | switch (c) |
| 51 | { |
| 52 | case '\0': |
| 53 | continue; |
| 54 | |
| 55 | case '\\': |
| 56 | switch (c = *s++) |
| 57 | { |
| 58 | case '\\': |
| 59 | *f++ = '\\'; |
| 60 | break; |
| 61 | case 'a': |
| 62 | *f++ = '\a'; |
| 63 | break; |
| 64 | case 'b': |
| 65 | *f++ = '\b'; |
| 66 | break; |
| 67 | case 'e': |
| 68 | *f++ = '\e'; |
| 69 | break; |
| 70 | case 'f': |
| 71 | *f++ = '\f'; |
| 72 | break; |
| 73 | case 'n': |
| 74 | *f++ = '\n'; |
| 75 | break; |
| 76 | case 'r': |
| 77 | *f++ = '\r'; |
| 78 | break; |
| 79 | case 't': |
| 80 | *f++ = '\t'; |
| 81 | break; |
| 82 | case 'v': |
| 83 | *f++ = '\v'; |
| 84 | break; |
| 85 | case '"': |
| 86 | *f++ = '"'; |
| 87 | break; |
| 88 | default: |
| 89 | /* ??? TODO: handle other escape sequences. */ |
| 90 | error (_("Unrecognized escape character \\%c in format string."), |
| 91 | c); |
| 92 | } |
| 93 | break; |
| 94 | |
| 95 | default: |
| 96 | *f++ = c; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | /* Terminate our escape-processed copy. */ |
| 101 | *f++ = '\0'; |
| 102 | |
| 103 | /* Whether the format string ended with double-quote or zero, we're |
| 104 | done with it; it's up to callers to complain about syntax. */ |
| 105 | *arg = s; |
| 106 | } |
| 107 | |
| 108 | /* Need extra space for the '\0's. Doubling the size is sufficient. */ |
| 109 | |
| 110 | current_substring = (char *) xmalloc (strlen (string) * 2 + 1000); |
| 111 | m_storage.reset (current_substring); |
| 112 | |
| 113 | /* Now scan the string for %-specs and see what kinds of args they want. |
| 114 | argclass classifies the %-specs so we can give printf-type functions |
| 115 | something of the right size. */ |
| 116 | |
| 117 | const char *f = string; |
| 118 | prev_start = string; |
| 119 | while (*f) |
| 120 | if (*f++ == '%') |
| 121 | { |
| 122 | int seen_hash = 0, seen_zero = 0, lcount = 0, seen_prec = 0; |
| 123 | int seen_space = 0, seen_plus = 0; |
| 124 | int seen_big_l = 0, seen_h = 0, seen_big_h = 0; |
| 125 | int seen_big_d = 0, seen_double_big_d = 0; |
| 126 | int seen_size_t = 0; |
| 127 | int bad = 0; |
| 128 | int n_int_args = 0; |
| 129 | bool seen_i64 = false; |
| 130 | |
| 131 | /* Skip over "%%", it will become part of a literal piece. */ |
| 132 | if (*f == '%') |
| 133 | { |
| 134 | f++; |
| 135 | continue; |
| 136 | } |
| 137 | |
| 138 | sub_start = current_substring; |
| 139 | |
| 140 | strncpy (current_substring, prev_start, f - 1 - prev_start); |
| 141 | current_substring += f - 1 - prev_start; |
| 142 | *current_substring++ = '\0'; |
| 143 | |
| 144 | if (*sub_start != '\0') |
| 145 | m_pieces.emplace_back (sub_start, literal_piece, 0); |
| 146 | |
| 147 | percent_loc = f - 1; |
| 148 | |
| 149 | /* Check the validity of the format specifier, and work |
| 150 | out what argument it expects. We only accept C89 |
| 151 | format strings, with the exception of long long (which |
| 152 | we autoconf for). */ |
| 153 | |
| 154 | /* The first part of a format specifier is a set of flag |
| 155 | characters. */ |
| 156 | while (*f != '\0' && strchr ("0-+ #", *f)) |
| 157 | { |
| 158 | if (*f == '#') |
| 159 | seen_hash = 1; |
| 160 | else if (*f == '0') |
| 161 | seen_zero = 1; |
| 162 | else if (*f == ' ') |
| 163 | seen_space = 1; |
| 164 | else if (*f == '+') |
| 165 | seen_plus = 1; |
| 166 | f++; |
| 167 | } |
| 168 | |
| 169 | /* The next part of a format specifier is a width. */ |
| 170 | if (gdb_extensions && *f == '*') |
| 171 | { |
| 172 | ++f; |
| 173 | ++n_int_args; |
| 174 | } |
| 175 | else |
| 176 | { |
| 177 | while (*f != '\0' && strchr ("0123456789", *f)) |
| 178 | f++; |
| 179 | } |
| 180 | |
| 181 | /* The next part of a format specifier is a precision. */ |
| 182 | if (*f == '.') |
| 183 | { |
| 184 | seen_prec = 1; |
| 185 | f++; |
| 186 | if (gdb_extensions && *f == '*') |
| 187 | { |
| 188 | ++f; |
| 189 | ++n_int_args; |
| 190 | } |
| 191 | else |
| 192 | { |
| 193 | while (*f != '\0' && strchr ("0123456789", *f)) |
| 194 | f++; |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | /* The next part of a format specifier is a length modifier. */ |
| 199 | switch (*f) |
| 200 | { |
| 201 | case 'h': |
| 202 | seen_h = 1; |
| 203 | f++; |
| 204 | break; |
| 205 | case 'l': |
| 206 | f++; |
| 207 | lcount++; |
| 208 | if (*f == 'l') |
| 209 | { |
| 210 | f++; |
| 211 | lcount++; |
| 212 | } |
| 213 | break; |
| 214 | case 'L': |
| 215 | seen_big_l = 1; |
| 216 | f++; |
| 217 | break; |
| 218 | case 'H': |
| 219 | /* Decimal32 modifier. */ |
| 220 | seen_big_h = 1; |
| 221 | f++; |
| 222 | break; |
| 223 | case 'D': |
| 224 | /* Decimal64 and Decimal128 modifiers. */ |
| 225 | f++; |
| 226 | |
| 227 | /* Check for a Decimal128. */ |
| 228 | if (*f == 'D') |
| 229 | { |
| 230 | f++; |
| 231 | seen_double_big_d = 1; |
| 232 | } |
| 233 | else |
| 234 | seen_big_d = 1; |
| 235 | break; |
| 236 | case 'z': |
| 237 | /* For size_t or ssize_t. */ |
| 238 | seen_size_t = 1; |
| 239 | f++; |
| 240 | break; |
| 241 | case 'I': |
| 242 | /* Support the Windows '%I64' extension, because an |
| 243 | earlier call to format_pieces might have converted %lld |
| 244 | to %I64d. */ |
| 245 | if (f[1] == '6' && f[2] == '4') |
| 246 | { |
| 247 | f += 3; |
| 248 | lcount = 2; |
| 249 | seen_i64 = true; |
| 250 | } |
| 251 | break; |
| 252 | } |
| 253 | |
| 254 | switch (*f) |
| 255 | { |
| 256 | case 'u': |
| 257 | if (seen_hash) |
| 258 | bad = 1; |
| 259 | /* FALLTHROUGH */ |
| 260 | |
| 261 | case 'o': |
| 262 | case 'x': |
| 263 | case 'X': |
| 264 | if (seen_space || seen_plus) |
| 265 | bad = 1; |
| 266 | /* FALLTHROUGH */ |
| 267 | |
| 268 | case 'd': |
| 269 | case 'i': |
| 270 | if (seen_size_t) |
| 271 | this_argclass = size_t_arg; |
| 272 | else if (lcount == 0) |
| 273 | this_argclass = int_arg; |
| 274 | else if (lcount == 1) |
| 275 | this_argclass = long_arg; |
| 276 | else |
| 277 | this_argclass = long_long_arg; |
| 278 | |
| 279 | if (seen_big_l) |
| 280 | bad = 1; |
| 281 | break; |
| 282 | |
| 283 | case 'c': |
| 284 | this_argclass = lcount == 0 ? int_arg : wide_char_arg; |
| 285 | if (lcount > 1 || seen_h || seen_big_l) |
| 286 | bad = 1; |
| 287 | if (seen_prec || seen_zero || seen_space || seen_plus) |
| 288 | bad = 1; |
| 289 | break; |
| 290 | |
| 291 | case 'p': |
| 292 | this_argclass = ptr_arg; |
| 293 | if (lcount || seen_h || seen_big_l) |
| 294 | bad = 1; |
| 295 | if (seen_prec) |
| 296 | bad = 1; |
| 297 | if (seen_hash || seen_zero || seen_space || seen_plus) |
| 298 | bad = 1; |
| 299 | |
| 300 | if (gdb_extensions) |
| 301 | { |
| 302 | switch (f[1]) |
| 303 | { |
| 304 | case 's': |
| 305 | case 'F': |
| 306 | case '[': |
| 307 | case ']': |
| 308 | f++; |
| 309 | break; |
| 310 | } |
| 311 | } |
| 312 | |
| 313 | break; |
| 314 | |
| 315 | case 's': |
| 316 | this_argclass = lcount == 0 ? string_arg : wide_string_arg; |
| 317 | if (lcount > 1 || seen_h || seen_big_l) |
| 318 | bad = 1; |
| 319 | if (seen_zero || seen_space || seen_plus) |
| 320 | bad = 1; |
| 321 | break; |
| 322 | |
| 323 | case 'e': |
| 324 | case 'f': |
| 325 | case 'g': |
| 326 | case 'E': |
| 327 | case 'G': |
| 328 | if (seen_double_big_d) |
| 329 | this_argclass = dec128float_arg; |
| 330 | else if (seen_big_d) |
| 331 | this_argclass = dec64float_arg; |
| 332 | else if (seen_big_h) |
| 333 | this_argclass = dec32float_arg; |
| 334 | else if (seen_big_l) |
| 335 | this_argclass = long_double_arg; |
| 336 | else |
| 337 | this_argclass = double_arg; |
| 338 | |
| 339 | if (lcount || seen_h) |
| 340 | bad = 1; |
| 341 | break; |
| 342 | |
| 343 | case '*': |
| 344 | error (_("`*' not supported for precision or width in printf")); |
| 345 | |
| 346 | case 'n': |
| 347 | error (_("Format specifier `n' not supported in printf")); |
| 348 | |
| 349 | case '\0': |
| 350 | error (_("Incomplete format specifier at end of format string")); |
| 351 | |
| 352 | default: |
| 353 | error (_("Unrecognized format specifier '%c' in printf"), *f); |
| 354 | } |
| 355 | |
| 356 | if (bad) |
| 357 | error (_("Inappropriate modifiers to " |
| 358 | "format specifier '%c' in printf"), |
| 359 | *f); |
| 360 | |
| 361 | f++; |
| 362 | |
| 363 | sub_start = current_substring; |
| 364 | |
| 365 | if (lcount > 1 && !seen_i64 && USE_PRINTF_I64) |
| 366 | { |
| 367 | /* Windows' printf does support long long, but not the usual way. |
| 368 | Convert %lld to %I64d. */ |
| 369 | int length_before_ll = f - percent_loc - 1 - lcount; |
| 370 | |
| 371 | strncpy (current_substring, percent_loc, length_before_ll); |
| 372 | strcpy (current_substring + length_before_ll, "I64"); |
| 373 | current_substring[length_before_ll + 3] = |
| 374 | percent_loc[length_before_ll + lcount]; |
| 375 | current_substring += length_before_ll + 4; |
| 376 | } |
| 377 | else if (this_argclass == wide_string_arg |
| 378 | || this_argclass == wide_char_arg) |
| 379 | { |
| 380 | /* Convert %ls or %lc to %s. */ |
| 381 | int length_before_ls = f - percent_loc - 2; |
| 382 | |
| 383 | strncpy (current_substring, percent_loc, length_before_ls); |
| 384 | strcpy (current_substring + length_before_ls, "s"); |
| 385 | current_substring += length_before_ls + 2; |
| 386 | } |
| 387 | else |
| 388 | { |
| 389 | strncpy (current_substring, percent_loc, f - percent_loc); |
| 390 | current_substring += f - percent_loc; |
| 391 | } |
| 392 | |
| 393 | *current_substring++ = '\0'; |
| 394 | |
| 395 | prev_start = f; |
| 396 | |
| 397 | m_pieces.emplace_back (sub_start, this_argclass, n_int_args); |
| 398 | } |
| 399 | |
| 400 | /* Record the remainder of the string. */ |
| 401 | |
| 402 | if (f > prev_start) |
| 403 | { |
| 404 | sub_start = current_substring; |
| 405 | |
| 406 | strncpy (current_substring, prev_start, f - prev_start); |
| 407 | current_substring += f - prev_start; |
| 408 | *current_substring++ = '\0'; |
| 409 | |
| 410 | m_pieces.emplace_back (sub_start, literal_piece, 0); |
| 411 | } |
| 412 | } |