[RS6000] dg-do !compile and scan-assembler
[official-gcc.git] / zlib / gzlib.c
blob4105e6aff92594fb9cfa557aa8349cea5a5d4a2b
1 /* gzlib.c -- zlib functions common to reading and writing gzip files
2 * Copyright (C) 2004-2017 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
6 #include "gzguts.h"
8 #if defined(_WIN32) && !defined(__BORLANDC__) && !defined(__MINGW32__)
9 # define LSEEK _lseeki64
10 #else
11 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
12 # define LSEEK lseek64
13 #else
14 # define LSEEK lseek
15 #endif
16 #endif
18 /* Local functions */
19 local void gz_reset OF((gz_statep));
20 local gzFile gz_open OF((const void *, int, const char *));
22 #if defined UNDER_CE
24 /* Map the Windows error number in ERROR to a locale-dependent error message
25 string and return a pointer to it. Typically, the values for ERROR come
26 from GetLastError.
28 The string pointed to shall not be modified by the application, but may be
29 overwritten by a subsequent call to gz_strwinerror
31 The gz_strwinerror function does not change the current setting of
32 GetLastError. */
33 char ZLIB_INTERNAL *gz_strwinerror (error)
34 DWORD error;
36 static char buf[1024];
38 wchar_t *msgbuf;
39 DWORD lasterr = GetLastError();
40 DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
41 | FORMAT_MESSAGE_ALLOCATE_BUFFER,
42 NULL,
43 error,
44 0, /* Default language */
45 (LPVOID)&msgbuf,
47 NULL);
48 if (chars != 0) {
49 /* If there is an \r\n appended, zap it. */
50 if (chars >= 2
51 && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
52 chars -= 2;
53 msgbuf[chars] = 0;
56 if (chars > sizeof (buf) - 1) {
57 chars = sizeof (buf) - 1;
58 msgbuf[chars] = 0;
61 wcstombs(buf, msgbuf, chars + 1);
62 LocalFree(msgbuf);
64 else {
65 sprintf(buf, "unknown win32 error (%ld)", error);
68 SetLastError(lasterr);
69 return buf;
72 #endif /* UNDER_CE */
74 /* Reset gzip file state */
75 local void gz_reset(state)
76 gz_statep state;
78 state->x.have = 0; /* no output data available */
79 if (state->mode == GZ_READ) { /* for reading ... */
80 state->eof = 0; /* not at end of file */
81 state->past = 0; /* have not read past end yet */
82 state->how = LOOK; /* look for gzip header */
84 state->seek = 0; /* no seek request pending */
85 gz_error(state, Z_OK, NULL); /* clear error */
86 state->x.pos = 0; /* no uncompressed data yet */
87 state->strm.avail_in = 0; /* no input data yet */
90 /* Open a gzip file either by name or file descriptor. */
91 local gzFile gz_open(path, fd, mode)
92 const void *path;
93 int fd;
94 const char *mode;
96 gz_statep state;
97 z_size_t len;
98 int oflag;
99 #ifdef O_CLOEXEC
100 int cloexec = 0;
101 #endif
102 #ifdef O_EXCL
103 int exclusive = 0;
104 #endif
106 /* check input */
107 if (path == NULL)
108 return NULL;
110 /* allocate gzFile structure to return */
111 state = (gz_statep)malloc(sizeof(gz_state));
112 if (state == NULL)
113 return NULL;
114 state->size = 0; /* no buffers allocated yet */
115 state->want = GZBUFSIZE; /* requested buffer size */
116 state->msg = NULL; /* no error message yet */
118 /* interpret mode */
119 state->mode = GZ_NONE;
120 state->level = Z_DEFAULT_COMPRESSION;
121 state->strategy = Z_DEFAULT_STRATEGY;
122 state->direct = 0;
123 while (*mode) {
124 if (*mode >= '0' && *mode <= '9')
125 state->level = *mode - '0';
126 else
127 switch (*mode) {
128 case 'r':
129 state->mode = GZ_READ;
130 break;
131 #ifndef NO_GZCOMPRESS
132 case 'w':
133 state->mode = GZ_WRITE;
134 break;
135 case 'a':
136 state->mode = GZ_APPEND;
137 break;
138 #endif
139 case '+': /* can't read and write at the same time */
140 free(state);
141 return NULL;
142 case 'b': /* ignore -- will request binary anyway */
143 break;
144 #ifdef O_CLOEXEC
145 case 'e':
146 cloexec = 1;
147 break;
148 #endif
149 #ifdef O_EXCL
150 case 'x':
151 exclusive = 1;
152 break;
153 #endif
154 case 'f':
155 state->strategy = Z_FILTERED;
156 break;
157 case 'h':
158 state->strategy = Z_HUFFMAN_ONLY;
159 break;
160 case 'R':
161 state->strategy = Z_RLE;
162 break;
163 case 'F':
164 state->strategy = Z_FIXED;
165 break;
166 case 'T':
167 state->direct = 1;
168 break;
169 default: /* could consider as an error, but just ignore */
172 mode++;
175 /* must provide an "r", "w", or "a" */
176 if (state->mode == GZ_NONE) {
177 free(state);
178 return NULL;
181 /* can't force transparent read */
182 if (state->mode == GZ_READ) {
183 if (state->direct) {
184 free(state);
185 return NULL;
187 state->direct = 1; /* for empty file */
190 /* save the path name for error messages */
191 #ifdef WIDECHAR
192 if (fd == -2) {
193 len = wcstombs(NULL, path, 0);
194 if (len == (z_size_t)-1)
195 len = 0;
197 else
198 #endif
199 len = strlen((const char *)path);
200 state->path = (char *)malloc(len + 1);
201 if (state->path == NULL) {
202 free(state);
203 return NULL;
205 #ifdef WIDECHAR
206 if (fd == -2)
207 if (len)
208 wcstombs(state->path, path, len + 1);
209 else
210 *(state->path) = 0;
211 else
212 #endif
213 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
214 (void)snprintf(state->path, len + 1, "%s", (const char *)path);
215 #else
216 strcpy(state->path, path);
217 #endif
219 /* compute the flags for open() */
220 oflag =
221 #ifdef O_LARGEFILE
222 O_LARGEFILE |
223 #endif
224 #ifdef O_BINARY
225 O_BINARY |
226 #endif
227 #ifdef O_CLOEXEC
228 (cloexec ? O_CLOEXEC : 0) |
229 #endif
230 (state->mode == GZ_READ ?
231 O_RDONLY :
232 (O_WRONLY | O_CREAT |
233 #ifdef O_EXCL
234 (exclusive ? O_EXCL : 0) |
235 #endif
236 (state->mode == GZ_WRITE ?
237 O_TRUNC :
238 O_APPEND)));
240 /* open the file with the appropriate flags (or just use fd) */
241 state->fd = fd > -1 ? fd : (
242 #ifdef WIDECHAR
243 fd == -2 ? _wopen(path, oflag, 0666) :
244 #endif
245 open((const char *)path, oflag, 0666));
246 if (state->fd == -1) {
247 free(state->path);
248 free(state);
249 return NULL;
251 if (state->mode == GZ_APPEND) {
252 LSEEK(state->fd, 0, SEEK_END); /* so gzoffset() is correct */
253 state->mode = GZ_WRITE; /* simplify later checks */
256 /* save the current position for rewinding (only if reading) */
257 if (state->mode == GZ_READ) {
258 state->start = LSEEK(state->fd, 0, SEEK_CUR);
259 if (state->start == -1) state->start = 0;
262 /* initialize stream */
263 gz_reset(state);
265 /* return stream */
266 return (gzFile)state;
269 /* -- see zlib.h -- */
270 gzFile ZEXPORT gzopen(path, mode)
271 const char *path;
272 const char *mode;
274 return gz_open(path, -1, mode);
277 /* -- see zlib.h -- */
278 gzFile ZEXPORT gzopen64(path, mode)
279 const char *path;
280 const char *mode;
282 return gz_open(path, -1, mode);
285 /* -- see zlib.h -- */
286 gzFile ZEXPORT gzdopen(fd, mode)
287 int fd;
288 const char *mode;
290 char *path; /* identifier for error messages */
291 gzFile gz;
293 if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
294 return NULL;
295 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
296 (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd);
297 #else
298 sprintf(path, "<fd:%d>", fd); /* for debugging */
299 #endif
300 gz = gz_open(path, fd, mode);
301 free(path);
302 return gz;
305 /* -- see zlib.h -- */
306 #ifdef WIDECHAR
307 gzFile ZEXPORT gzopen_w(path, mode)
308 const wchar_t *path;
309 const char *mode;
311 return gz_open(path, -2, mode);
313 #endif
315 /* -- see zlib.h -- */
316 int ZEXPORT gzbuffer(file, size)
317 gzFile file;
318 unsigned size;
320 gz_statep state;
322 /* get internal structure and check integrity */
323 if (file == NULL)
324 return -1;
325 state = (gz_statep)file;
326 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
327 return -1;
329 /* make sure we haven't already allocated memory */
330 if (state->size != 0)
331 return -1;
333 /* check and set requested size */
334 if ((size << 1) < size)
335 return -1; /* need to be able to double it */
336 if (size < 2)
337 size = 2; /* need two bytes to check magic header */
338 state->want = size;
339 return 0;
342 /* -- see zlib.h -- */
343 int ZEXPORT gzrewind(file)
344 gzFile file;
346 gz_statep state;
348 /* get internal structure */
349 if (file == NULL)
350 return -1;
351 state = (gz_statep)file;
353 /* check that we're reading and that there's no error */
354 if (state->mode != GZ_READ ||
355 (state->err != Z_OK && state->err != Z_BUF_ERROR))
356 return -1;
358 /* back up and start over */
359 if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
360 return -1;
361 gz_reset(state);
362 return 0;
365 /* -- see zlib.h -- */
366 z_off64_t ZEXPORT gzseek64(file, offset, whence)
367 gzFile file;
368 z_off64_t offset;
369 int whence;
371 unsigned n;
372 z_off64_t ret;
373 gz_statep state;
375 /* get internal structure and check integrity */
376 if (file == NULL)
377 return -1;
378 state = (gz_statep)file;
379 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
380 return -1;
382 /* check that there's no error */
383 if (state->err != Z_OK && state->err != Z_BUF_ERROR)
384 return -1;
386 /* can only seek from start or relative to current position */
387 if (whence != SEEK_SET && whence != SEEK_CUR)
388 return -1;
390 /* normalize offset to a SEEK_CUR specification */
391 if (whence == SEEK_SET)
392 offset -= state->x.pos;
393 else if (state->seek)
394 offset += state->skip;
395 state->seek = 0;
397 /* if within raw area while reading, just go there */
398 if (state->mode == GZ_READ && state->how == COPY &&
399 state->x.pos + offset >= 0) {
400 ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
401 if (ret == -1)
402 return -1;
403 state->x.have = 0;
404 state->eof = 0;
405 state->past = 0;
406 state->seek = 0;
407 gz_error(state, Z_OK, NULL);
408 state->strm.avail_in = 0;
409 state->x.pos += offset;
410 return state->x.pos;
413 /* calculate skip amount, rewinding if needed for back seek when reading */
414 if (offset < 0) {
415 if (state->mode != GZ_READ) /* writing -- can't go backwards */
416 return -1;
417 offset += state->x.pos;
418 if (offset < 0) /* before start of file! */
419 return -1;
420 if (gzrewind(file) == -1) /* rewind, then skip to offset */
421 return -1;
424 /* if reading, skip what's in output buffer (one less gzgetc() check) */
425 if (state->mode == GZ_READ) {
426 n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ?
427 (unsigned)offset : state->x.have;
428 state->x.have -= n;
429 state->x.next += n;
430 state->x.pos += n;
431 offset -= n;
434 /* request skip (if not zero) */
435 if (offset) {
436 state->seek = 1;
437 state->skip = offset;
439 return state->x.pos + offset;
442 /* -- see zlib.h -- */
443 z_off_t ZEXPORT gzseek(file, offset, whence)
444 gzFile file;
445 z_off_t offset;
446 int whence;
448 z_off64_t ret;
450 ret = gzseek64(file, (z_off64_t)offset, whence);
451 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
454 /* -- see zlib.h -- */
455 z_off64_t ZEXPORT gztell64(file)
456 gzFile file;
458 gz_statep state;
460 /* get internal structure and check integrity */
461 if (file == NULL)
462 return -1;
463 state = (gz_statep)file;
464 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
465 return -1;
467 /* return position */
468 return state->x.pos + (state->seek ? state->skip : 0);
471 /* -- see zlib.h -- */
472 z_off_t ZEXPORT gztell(file)
473 gzFile file;
475 z_off64_t ret;
477 ret = gztell64(file);
478 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
481 /* -- see zlib.h -- */
482 z_off64_t ZEXPORT gzoffset64(file)
483 gzFile file;
485 z_off64_t offset;
486 gz_statep state;
488 /* get internal structure and check integrity */
489 if (file == NULL)
490 return -1;
491 state = (gz_statep)file;
492 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
493 return -1;
495 /* compute and return effective offset in file */
496 offset = LSEEK(state->fd, 0, SEEK_CUR);
497 if (offset == -1)
498 return -1;
499 if (state->mode == GZ_READ) /* reading */
500 offset -= state->strm.avail_in; /* don't count buffered input */
501 return offset;
504 /* -- see zlib.h -- */
505 z_off_t ZEXPORT gzoffset(file)
506 gzFile file;
508 z_off64_t ret;
510 ret = gzoffset64(file);
511 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
514 /* -- see zlib.h -- */
515 int ZEXPORT gzeof(file)
516 gzFile file;
518 gz_statep state;
520 /* get internal structure and check integrity */
521 if (file == NULL)
522 return 0;
523 state = (gz_statep)file;
524 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
525 return 0;
527 /* return end-of-file state */
528 return state->mode == GZ_READ ? state->past : 0;
531 /* -- see zlib.h -- */
532 const char * ZEXPORT gzerror(file, errnum)
533 gzFile file;
534 int *errnum;
536 gz_statep state;
538 /* get internal structure and check integrity */
539 if (file == NULL)
540 return NULL;
541 state = (gz_statep)file;
542 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
543 return NULL;
545 /* return error information */
546 if (errnum != NULL)
547 *errnum = state->err;
548 return state->err == Z_MEM_ERROR ? "out of memory" :
549 (state->msg == NULL ? "" : state->msg);
552 /* -- see zlib.h -- */
553 void ZEXPORT gzclearerr(file)
554 gzFile file;
556 gz_statep state;
558 /* get internal structure and check integrity */
559 if (file == NULL)
560 return;
561 state = (gz_statep)file;
562 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
563 return;
565 /* clear error and end-of-file */
566 if (state->mode == GZ_READ) {
567 state->eof = 0;
568 state->past = 0;
570 gz_error(state, Z_OK, NULL);
573 /* Create an error message in allocated memory and set state->err and
574 state->msg accordingly. Free any previous error message already there. Do
575 not try to free or allocate space if the error is Z_MEM_ERROR (out of
576 memory). Simply save the error message as a static string. If there is an
577 allocation failure constructing the error message, then convert the error to
578 out of memory. */
579 void ZLIB_INTERNAL gz_error(state, err, msg)
580 gz_statep state;
581 int err;
582 const char *msg;
584 /* free previously allocated message and clear */
585 if (state->msg != NULL) {
586 if (state->err != Z_MEM_ERROR)
587 free(state->msg);
588 state->msg = NULL;
591 /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
592 if (err != Z_OK && err != Z_BUF_ERROR)
593 state->x.have = 0;
595 /* set error code, and if no message, then done */
596 state->err = err;
597 if (msg == NULL)
598 return;
600 /* for an out of memory error, return literal string when requested */
601 if (err == Z_MEM_ERROR)
602 return;
604 /* construct error message with path */
605 if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
606 NULL) {
607 state->err = Z_MEM_ERROR;
608 return;
610 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
611 (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
612 "%s%s%s", state->path, ": ", msg);
613 #else
614 strcpy(state->msg, state->path);
615 strcat(state->msg, ": ");
616 strcat(state->msg, msg);
617 #endif
620 #ifndef INT_MAX
621 /* portably return maximum value for an int (when limits.h presumed not
622 available) -- we need to do this to cover cases where 2's complement not
623 used, since C standard permits 1's complement and sign-bit representations,
624 otherwise we could just use ((unsigned)-1) >> 1 */
625 unsigned ZLIB_INTERNAL gz_intmax()
627 unsigned p, q;
629 p = 1;
630 do {
631 q = p;
632 p <<= 1;
633 p++;
634 } while (p > q);
635 return q >> 1;
637 #endif