1 /* 2 * ***************************************************************************** 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2018-2021 Gavin D. Howard and contributors. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * * Redistributions of source code must retain the above copyright notice, this 12 * list of conditions and the following disclaimer. 13 * 14 * * Redistributions in binary form must reproduce the above copyright notice, 15 * this list of conditions and the following disclaimer in the documentation 16 * and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 * 30 * ***************************************************************************** 31 * 32 * Code for implementing buffered I/O on my own terms. 33 * 34 */ 35 36 #include <assert.h> 37 #include <errno.h> 38 #include <string.h> 39 40 #ifndef _WIN32 41 #include <unistd.h> 42 #endif // _WIN32 43 44 #include <file.h> 45 #include <vm.h> 46 47 #if !BC_ENABLE_LINE_LIB 48 49 /** 50 * Translates an integer into a string. 51 * @param val The value to translate. 52 * @param buf The return parameter. 53 */ 54 static void 55 bc_file_ultoa(unsigned long long val, char buf[BC_FILE_ULL_LENGTH]) 56 { 57 char buf2[BC_FILE_ULL_LENGTH]; 58 size_t i, len; 59 60 // We need to make sure the entire thing is zeroed. 61 // NOLINTNEXTLINE 62 memset(buf2, 0, BC_FILE_ULL_LENGTH); 63 64 // The i = 1 is to ensure that there is a null byte at the end. 65 for (i = 1; val; ++i) 66 { 67 unsigned long long mod = val % 10; 68 69 buf2[i] = ((char) mod) + '0'; 70 val /= 10; 71 } 72 73 len = i; 74 75 // Since buf2 is reversed, reverse it into buf. 76 for (i = 0; i < len; ++i) 77 { 78 buf[i] = buf2[len - i - 1]; 79 } 80 } 81 82 /** 83 * Output to the file directly. 84 * @param fd The file descriptor. 85 * @param buf The buffer of data to output. 86 * @param n The number of bytes to output. 87 * @return A status indicating error or success. We could have a fatal I/O 88 * error or EOF. 89 */ 90 static BcStatus 91 bc_file_output(int fd, const char* buf, size_t n) 92 { 93 size_t bytes = 0; 94 sig_atomic_t lock; 95 96 BC_SIG_TRYLOCK(lock); 97 98 // While the number of bytes written is less than intended... 99 while (bytes < n) 100 { 101 // Write. 102 ssize_t written = write(fd, buf + bytes, n - bytes); 103 104 // Check for error and return, if any. 105 if (BC_ERR(written == -1)) 106 { 107 BC_SIG_TRYUNLOCK(lock); 108 109 return errno == EPIPE ? BC_STATUS_EOF : BC_STATUS_ERROR_FATAL; 110 } 111 112 bytes += (size_t) written; 113 } 114 115 BC_SIG_TRYUNLOCK(lock); 116 117 return BC_STATUS_SUCCESS; 118 } 119 120 #endif // !BC_ENABLE_LINE_LIB 121 122 BcStatus 123 bc_file_flushErr(BcFile* restrict f, BcFlushType type) 124 { 125 BcStatus s; 126 127 BC_SIG_ASSERT_LOCKED; 128 129 #if BC_ENABLE_LINE_LIB 130 131 // Just flush and propagate the error. 132 if (fflush(f->f) == EOF) s = BC_STATUS_ERROR_FATAL; 133 else s = BC_STATUS_SUCCESS; 134 135 #else // BC_ENABLE_LINE_LIB 136 137 // If there is stuff to output... 138 if (f->len) 139 { 140 #if BC_ENABLE_HISTORY 141 142 // If history is enabled... 143 if (BC_TTY) 144 { 145 // If we have been told to save the extras, and there *are* 146 // extras... 147 if (f->buf[f->len - 1] != '\n' && 148 (type == BC_FLUSH_SAVE_EXTRAS_CLEAR || 149 type == BC_FLUSH_SAVE_EXTRAS_NO_CLEAR)) 150 { 151 size_t i; 152 153 // Look for the last newline. 154 for (i = f->len - 2; i < f->len && f->buf[i] != '\n'; --i) 155 { 156 continue; 157 } 158 159 i += 1; 160 161 // Save the extras. 162 bc_vec_string(&vm.history.extras, f->len - i, f->buf + i); 163 } 164 // Else clear the extras if told to. 165 else if (type >= BC_FLUSH_NO_EXTRAS_CLEAR) 166 { 167 bc_vec_popAll(&vm.history.extras); 168 } 169 } 170 #endif // BC_ENABLE_HISTORY 171 172 // Actually output. 173 s = bc_file_output(f->fd, f->buf, f->len); 174 f->len = 0; 175 } 176 else s = BC_STATUS_SUCCESS; 177 178 #endif // BC_ENABLE_LINE_LIB 179 180 return s; 181 } 182 183 void 184 bc_file_flush(BcFile* restrict f, BcFlushType type) 185 { 186 BcStatus s; 187 sig_atomic_t lock; 188 189 BC_SIG_TRYLOCK(lock); 190 191 s = bc_file_flushErr(f, type); 192 193 // If we have an error... 194 if (BC_ERR(s)) 195 { 196 // For EOF, set it and jump. 197 if (s == BC_STATUS_EOF) 198 { 199 vm.status = (sig_atomic_t) s; 200 BC_SIG_TRYUNLOCK(lock); 201 BC_JMP; 202 } 203 // Blow up on fatal error. Okay, not blow up, just quit. 204 else bc_vm_fatalError(BC_ERR_FATAL_IO_ERR); 205 } 206 207 BC_SIG_TRYUNLOCK(lock); 208 } 209 210 #if !BC_ENABLE_LINE_LIB 211 212 void 213 bc_file_write(BcFile* restrict f, BcFlushType type, const char* buf, size_t n) 214 { 215 sig_atomic_t lock; 216 217 BC_SIG_TRYLOCK(lock); 218 219 // If we have enough to flush, do it. 220 if (n > f->cap - f->len) 221 { 222 bc_file_flush(f, type); 223 assert(!f->len); 224 } 225 226 // If the output is large enough to flush by itself, just output it. 227 // Otherwise, put it into the buffer. 228 if (BC_UNLIKELY(n > f->cap - f->len)) 229 { 230 BcStatus s = bc_file_output(f->fd, buf, n); 231 232 if (BC_ERR(s)) 233 { 234 // For EOF, set it and jump. 235 if (s == BC_STATUS_EOF) 236 { 237 vm.status = (sig_atomic_t) s; 238 BC_SIG_TRYUNLOCK(lock); 239 BC_JMP; 240 } 241 // Blow up on fatal error. Okay, not blow up, just quit. 242 else bc_vm_fatalError(BC_ERR_FATAL_IO_ERR); 243 } 244 } 245 else 246 { 247 // NOLINTNEXTLINE 248 memcpy(f->buf + f->len, buf, n); 249 f->len += n; 250 } 251 252 BC_SIG_TRYUNLOCK(lock); 253 } 254 255 #endif // BC_ENABLE_LINE_LIB 256 257 void 258 bc_file_printf(BcFile* restrict f, const char* fmt, ...) 259 { 260 va_list args; 261 sig_atomic_t lock; 262 263 BC_SIG_TRYLOCK(lock); 264 265 va_start(args, fmt); 266 bc_file_vprintf(f, fmt, args); 267 va_end(args); 268 269 BC_SIG_TRYUNLOCK(lock); 270 } 271 272 void 273 bc_file_vprintf(BcFile* restrict f, const char* fmt, va_list args) 274 { 275 BC_SIG_ASSERT_LOCKED; 276 277 #if BC_ENABLE_LINE_LIB 278 279 // Just print and propagate the error. 280 if (BC_ERR(vfprintf(f->f, fmt, args) < 0)) 281 { 282 bc_vm_fatalError(BC_ERR_FATAL_IO_ERR); 283 } 284 285 #else // BC_ENABLE_LINE_LIB 286 287 char* percent; 288 const char* ptr = fmt; 289 char buf[BC_FILE_ULL_LENGTH]; 290 291 // This is a poor man's printf(). While I could look up algorithms to make 292 // it as fast as possible, and should when I write the standard library for 293 // a new language, for bc, outputting is not the bottleneck. So we cheese it 294 // for now. 295 296 // Find each percent sign. 297 while ((percent = strchr(ptr, '%')) != NULL) 298 { 299 char c; 300 301 // If the percent sign is not where we are, write what's inbetween to 302 // the buffer. 303 if (percent != ptr) 304 { 305 size_t len = (size_t) (percent - ptr); 306 bc_file_write(f, bc_flush_none, ptr, len); 307 } 308 309 c = percent[1]; 310 311 // We only parse some format specifiers, the ones bc uses. If you add 312 // more, you need to make sure to add them here. 313 if (c == 'c') 314 { 315 uchar uc = (uchar) va_arg(args, int); 316 317 bc_file_putchar(f, bc_flush_none, uc); 318 } 319 else if (c == 's') 320 { 321 char* s = va_arg(args, char*); 322 323 bc_file_puts(f, bc_flush_none, s); 324 } 325 #if BC_DEBUG_CODE 326 // We only print signed integers in debug code. 327 else if (c == 'd') 328 { 329 int d = va_arg(args, int); 330 331 // Take care of negative. Let's not worry about overflow. 332 if (d < 0) 333 { 334 bc_file_putchar(f, bc_flush_none, '-'); 335 d = -d; 336 } 337 338 // Either print 0 or translate and print. 339 if (!d) bc_file_putchar(f, bc_flush_none, '0'); 340 else 341 { 342 bc_file_ultoa((unsigned long long) d, buf); 343 bc_file_puts(f, bc_flush_none, buf); 344 } 345 } 346 #endif // BC_DEBUG_CODE 347 else 348 { 349 unsigned long long ull; 350 351 // These are the ones that it expects from here. Fortunately, all of 352 // these are unsigned types, so they can use the same code, more or 353 // less. 354 assert((c == 'l' || c == 'z') && percent[2] == 'u'); 355 356 if (c == 'z') ull = (unsigned long long) va_arg(args, size_t); 357 else ull = (unsigned long long) va_arg(args, unsigned long); 358 359 // Either print 0 or translate and print. 360 if (!ull) bc_file_putchar(f, bc_flush_none, '0'); 361 else 362 { 363 bc_file_ultoa(ull, buf); 364 bc_file_puts(f, bc_flush_none, buf); 365 } 366 } 367 368 // Increment to the next spot after the specifier. 369 ptr = percent + 2 + (c == 'l' || c == 'z'); 370 } 371 372 // If we get here, there are no more percent signs, so we just output 373 // whatever is left. 374 if (ptr[0]) bc_file_puts(f, bc_flush_none, ptr); 375 376 #endif // BC_ENABLE_LINE_LIB 377 } 378 379 void 380 bc_file_puts(BcFile* restrict f, BcFlushType type, const char* str) 381 { 382 #if BC_ENABLE_LINE_LIB 383 // This is used because of flushing issues with using bc_file_write() when 384 // bc is using a line library. It's also using printf() because puts() 385 // writes a newline. 386 bc_file_printf(f, "%s", str); 387 #else // BC_ENABLE_LINE_LIB 388 bc_file_write(f, type, str, strlen(str)); 389 #endif // BC_ENABLE_LINE_LIB 390 } 391 392 void 393 bc_file_putchar(BcFile* restrict f, BcFlushType type, uchar c) 394 { 395 sig_atomic_t lock; 396 397 BC_SIG_TRYLOCK(lock); 398 399 #if BC_ENABLE_LINE_LIB 400 401 if (BC_ERR(fputc(c, f->f) == EOF)) 402 { 403 // This is here to prevent a stack overflow from unbounded recursion. 404 if (f->f == stderr) exit(BC_STATUS_ERROR_FATAL); 405 406 bc_vm_fatalError(BC_ERR_FATAL_IO_ERR); 407 } 408 409 #else // BC_ENABLE_LINE_LIB 410 411 if (f->len == f->cap) bc_file_flush(f, type); 412 413 assert(f->len < f->cap); 414 415 f->buf[f->len] = (char) c; 416 f->len += 1; 417 418 #endif // BC_ENABLE_LINE_LIB 419 420 BC_SIG_TRYUNLOCK(lock); 421 } 422 423 #if BC_ENABLE_LINE_LIB 424 425 void 426 bc_file_init(BcFile* f, FILE* file) 427 { 428 BC_SIG_ASSERT_LOCKED; 429 f->f = file; 430 } 431 432 #else // BC_ENABLE_LINE_LIB 433 434 void 435 bc_file_init(BcFile* f, int fd, char* buf, size_t cap) 436 { 437 BC_SIG_ASSERT_LOCKED; 438 439 f->fd = fd; 440 f->buf = buf; 441 f->len = 0; 442 f->cap = cap; 443 } 444 445 #endif // BC_ENABLE_LINE_LIB 446 447 void 448 bc_file_free(BcFile* f) 449 { 450 BC_SIG_ASSERT_LOCKED; 451 bc_file_flush(f, bc_flush_none); 452 } 453