6057f1f58015ad7cae9792309dd635a1e7933586
[git/git.git] / convert.c
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "config.h"
4 #include "object-store.h"
5 #include "attr.h"
6 #include "run-command.h"
7 #include "quote.h"
8 #include "sigchain.h"
9 #include "pkt-line.h"
10 #include "sub-process.h"
11 #include "utf8.h"
12
13 /*
14 * convert.c - convert a file when checking it out and checking it in.
15 *
16 * This should use the pathname to decide on whether it wants to do some
17 * more interesting conversions (automatic gzip/unzip, general format
18 * conversions etc etc), but by default it just does automatic CRLF<->LF
19 * translation when the "text" attribute or "auto_crlf" option is set.
20 */
21
22 /* Stat bits: When BIN is set, the txt bits are unset */
23 #define CONVERT_STAT_BITS_TXT_LF 0x1
24 #define CONVERT_STAT_BITS_TXT_CRLF 0x2
25 #define CONVERT_STAT_BITS_BIN 0x4
26
27 enum crlf_action {
28 CRLF_UNDEFINED,
29 CRLF_BINARY,
30 CRLF_TEXT,
31 CRLF_TEXT_INPUT,
32 CRLF_TEXT_CRLF,
33 CRLF_AUTO,
34 CRLF_AUTO_INPUT,
35 CRLF_AUTO_CRLF
36 };
37
38 struct text_stat {
39 /* NUL, CR, LF and CRLF counts */
40 unsigned nul, lonecr, lonelf, crlf;
41
42 /* These are just approximations! */
43 unsigned printable, nonprintable;
44 };
45
46 static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
47 {
48 unsigned long i;
49
50 memset(stats, 0, sizeof(*stats));
51
52 for (i = 0; i < size; i++) {
53 unsigned char c = buf[i];
54 if (c == '\r') {
55 if (i+1 < size && buf[i+1] == '\n') {
56 stats->crlf++;
57 i++;
58 } else
59 stats->lonecr++;
60 continue;
61 }
62 if (c == '\n') {
63 stats->lonelf++;
64 continue;
65 }
66 if (c == 127)
67 /* DEL */
68 stats->nonprintable++;
69 else if (c < 32) {
70 switch (c) {
71 /* BS, HT, ESC and FF */
72 case '\b': case '\t': case '\033': case '\014':
73 stats->printable++;
74 break;
75 case 0:
76 stats->nul++;
77 /* fall through */
78 default:
79 stats->nonprintable++;
80 }
81 }
82 else
83 stats->printable++;
84 }
85
86 /* If file ends with EOF then don't count this EOF as non-printable. */
87 if (size >= 1 && buf[size-1] == '\032')
88 stats->nonprintable--;
89 }
90
91 /*
92 * The same heuristics as diff.c::mmfile_is_binary()
93 * We treat files with bare CR as binary
94 */
95 static int convert_is_binary(unsigned long size, const struct text_stat *stats)
96 {
97 if (stats->lonecr)
98 return 1;
99 if (stats->nul)
100 return 1;
101 if ((stats->printable >> 7) < stats->nonprintable)
102 return 1;
103 return 0;
104 }
105
106 static unsigned int gather_convert_stats(const char *data, unsigned long size)
107 {
108 struct text_stat stats;
109 int ret = 0;
110 if (!data || !size)
111 return 0;
112 gather_stats(data, size, &stats);
113 if (convert_is_binary(size, &stats))
114 ret |= CONVERT_STAT_BITS_BIN;
115 if (stats.crlf)
116 ret |= CONVERT_STAT_BITS_TXT_CRLF;
117 if (stats.lonelf)
118 ret |= CONVERT_STAT_BITS_TXT_LF;
119
120 return ret;
121 }
122
123 static const char *gather_convert_stats_ascii(const char *data, unsigned long size)
124 {
125 unsigned int convert_stats = gather_convert_stats(data, size);
126
127 if (convert_stats & CONVERT_STAT_BITS_BIN)
128 return "-text";
129 switch (convert_stats) {
130 case CONVERT_STAT_BITS_TXT_LF:
131 return "lf";
132 case CONVERT_STAT_BITS_TXT_CRLF:
133 return "crlf";
134 case CONVERT_STAT_BITS_TXT_LF | CONVERT_STAT_BITS_TXT_CRLF:
135 return "mixed";
136 default:
137 return "none";
138 }
139 }
140
141 const char *get_cached_convert_stats_ascii(const struct index_state *istate,
142 const char *path)
143 {
144 const char *ret;
145 unsigned long sz;
146 void *data = read_blob_data_from_index(istate, path, &sz);
147 ret = gather_convert_stats_ascii(data, sz);
148 free(data);
149 return ret;
150 }
151
152 const char *get_wt_convert_stats_ascii(const char *path)
153 {
154 const char *ret = "";
155 struct strbuf sb = STRBUF_INIT;
156 if (strbuf_read_file(&sb, path, 0) >= 0)
157 ret = gather_convert_stats_ascii(sb.buf, sb.len);
158 strbuf_release(&sb);
159 return ret;
160 }
161
162 static int text_eol_is_crlf(void)
163 {
164 if (auto_crlf == AUTO_CRLF_TRUE)
165 return 1;
166 else if (auto_crlf == AUTO_CRLF_INPUT)
167 return 0;
168 if (core_eol == EOL_CRLF)
169 return 1;
170 if (core_eol == EOL_UNSET && EOL_NATIVE == EOL_CRLF)
171 return 1;
172 return 0;
173 }
174
175 static enum eol output_eol(enum crlf_action crlf_action)
176 {
177 switch (crlf_action) {
178 case CRLF_BINARY:
179 return EOL_UNSET;
180 case CRLF_TEXT_CRLF:
181 return EOL_CRLF;
182 case CRLF_TEXT_INPUT:
183 return EOL_LF;
184 case CRLF_UNDEFINED:
185 case CRLF_AUTO_CRLF:
186 return EOL_CRLF;
187 case CRLF_AUTO_INPUT:
188 return EOL_LF;
189 case CRLF_TEXT:
190 case CRLF_AUTO:
191 /* fall through */
192 return text_eol_is_crlf() ? EOL_CRLF : EOL_LF;
193 }
194 warning(_("illegal crlf_action %d"), (int)crlf_action);
195 return core_eol;
196 }
197
198 static void check_global_conv_flags_eol(const char *path, enum crlf_action crlf_action,
199 struct text_stat *old_stats, struct text_stat *new_stats,
200 int conv_flags)
201 {
202 if (old_stats->crlf && !new_stats->crlf ) {
203 /*
204 * CRLFs would not be restored by checkout
205 */
206 if (conv_flags & CONV_EOL_RNDTRP_DIE)
207 die(_("CRLF would be replaced by LF in %s"), path);
208 else if (conv_flags & CONV_EOL_RNDTRP_WARN)
209 warning(_("CRLF will be replaced by LF in %s.\n"
210 "The file will have its original line"
211 " endings in your working directory"), path);
212 } else if (old_stats->lonelf && !new_stats->lonelf ) {
213 /*
214 * CRLFs would be added by checkout
215 */
216 if (conv_flags & CONV_EOL_RNDTRP_DIE)
217 die(_("LF would be replaced by CRLF in %s"), path);
218 else if (conv_flags & CONV_EOL_RNDTRP_WARN)
219 warning(_("LF will be replaced by CRLF in %s.\n"
220 "The file will have its original line"
221 " endings in your working directory"), path);
222 }
223 }
224
225 static int has_crlf_in_index(const struct index_state *istate, const char *path)
226 {
227 unsigned long sz;
228 void *data;
229 const char *crp;
230 int has_crlf = 0;
231
232 data = read_blob_data_from_index(istate, path, &sz);
233 if (!data)
234 return 0;
235
236 crp = memchr(data, '\r', sz);
237 if (crp) {
238 unsigned int ret_stats;
239 ret_stats = gather_convert_stats(data, sz);
240 if (!(ret_stats & CONVERT_STAT_BITS_BIN) &&
241 (ret_stats & CONVERT_STAT_BITS_TXT_CRLF))
242 has_crlf = 1;
243 }
244 free(data);
245 return has_crlf;
246 }
247
248 static int will_convert_lf_to_crlf(size_t len, struct text_stat *stats,
249 enum crlf_action crlf_action)
250 {
251 if (output_eol(crlf_action) != EOL_CRLF)
252 return 0;
253 /* No "naked" LF? Nothing to convert, regardless. */
254 if (!stats->lonelf)
255 return 0;
256
257 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
258 /* If we have any CR or CRLF line endings, we do not touch it */
259 /* This is the new safer autocrlf-handling */
260 if (stats->lonecr || stats->crlf)
261 return 0;
262
263 if (convert_is_binary(len, stats))
264 return 0;
265 }
266 return 1;
267
268 }
269
270 static int validate_encoding(const char *path, const char *enc,
271 const char *data, size_t len, int die_on_error)
272 {
273 /* We only check for UTF here as UTF?? can be an alias for UTF-?? */
274 if (istarts_with(enc, "UTF")) {
275 /*
276 * Check for detectable errors in UTF encodings
277 */
278 if (has_prohibited_utf_bom(enc, data, len)) {
279 const char *error_msg = _(
280 "BOM is prohibited in '%s' if encoded as %s");
281 /*
282 * This advice is shown for UTF-??BE and UTF-??LE encodings.
283 * We cut off the last two characters of the encoding name
284 * to generate the encoding name suitable for BOMs.
285 */
286 const char *advise_msg = _(
287 "The file '%s' contains a byte order "
288 "mark (BOM). Please use UTF-%s as "
289 "working-tree-encoding.");
290 const char *stripped = NULL;
291 char *upper = xstrdup_toupper(enc);
292 upper[strlen(upper)-2] = '\0';
293 if (!skip_prefix(upper, "UTF-", &stripped))
294 skip_prefix(stripped, "UTF", &stripped);
295 advise(advise_msg, path, stripped);
296 free(upper);
297 if (die_on_error)
298 die(error_msg, path, enc);
299 else {
300 return error(error_msg, path, enc);
301 }
302
303 } else if (is_missing_required_utf_bom(enc, data, len)) {
304 const char *error_msg = _(
305 "BOM is required in '%s' if encoded as %s");
306 const char *advise_msg = _(
307 "The file '%s' is missing a byte order "
308 "mark (BOM). Please use UTF-%sBE or UTF-%sLE "
309 "(depending on the byte order) as "
310 "working-tree-encoding.");
311 const char *stripped = NULL;
312 char *upper = xstrdup_toupper(enc);
313 if (!skip_prefix(upper, "UTF-", &stripped))
314 skip_prefix(stripped, "UTF", &stripped);
315 advise(advise_msg, path, stripped, stripped);
316 free(upper);
317 if (die_on_error)
318 die(error_msg, path, enc);
319 else {
320 return error(error_msg, path, enc);
321 }
322 }
323
324 }
325 return 0;
326 }
327
328 static void trace_encoding(const char *context, const char *path,
329 const char *encoding, const char *buf, size_t len)
330 {
331 static struct trace_key coe = TRACE_KEY_INIT(WORKING_TREE_ENCODING);
332 struct strbuf trace = STRBUF_INIT;
333 int i;
334
335 strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding);
336 for (i = 0; i < len && buf; ++i) {
337 strbuf_addf(
338 &trace, "| \033[2m%2i:\033[0m %2x \033[2m%c\033[0m%c",
339 i,
340 (unsigned char) buf[i],
341 (buf[i] > 32 && buf[i] < 127 ? buf[i] : ' '),
342 ((i+1) % 8 && (i+1) < len ? ' ' : '\n')
343 );
344 }
345 strbuf_addchars(&trace, '\n', 1);
346
347 trace_strbuf(&coe, &trace);
348 strbuf_release(&trace);
349 }
350
351 static int check_roundtrip(const char *enc_name)
352 {
353 /*
354 * check_roundtrip_encoding contains a string of comma and/or
355 * space separated encodings (eg. "UTF-16, ASCII, CP1125").
356 * Search for the given encoding in that string.
357 */
358 const char *found = strcasestr(check_roundtrip_encoding, enc_name);
359 const char *next;
360 int len;
361 if (!found)
362 return 0;
363 next = found + strlen(enc_name);
364 len = strlen(check_roundtrip_encoding);
365 return (found && (
366 /*
367 * check that the found encoding is at the
368 * beginning of check_roundtrip_encoding or
369 * that it is prefixed with a space or comma
370 */
371 found == check_roundtrip_encoding || (
372 (isspace(found[-1]) || found[-1] == ',')
373 )
374 ) && (
375 /*
376 * check that the found encoding is at the
377 * end of check_roundtrip_encoding or
378 * that it is suffixed with a space or comma
379 */
380 next == check_roundtrip_encoding + len || (
381 next < check_roundtrip_encoding + len &&
382 (isspace(next[0]) || next[0] == ',')
383 )
384 ));
385 }
386
387 static const char *default_encoding = "UTF-8";
388
389 static int encode_to_git(const char *path, const char *src, size_t src_len,
390 struct strbuf *buf, const char *enc, int conv_flags)
391 {
392 char *dst;
393 size_t dst_len;
394 int die_on_error = conv_flags & CONV_WRITE_OBJECT;
395
396 /*
397 * No encoding is specified or there is nothing to encode.
398 * Tell the caller that the content was not modified.
399 */
400 if (!enc || (src && !src_len))
401 return 0;
402
403 /*
404 * Looks like we got called from "would_convert_to_git()".
405 * This means Git wants to know if it would encode (= modify!)
406 * the content. Let's answer with "yes", since an encoding was
407 * specified.
408 */
409 if (!buf && !src)
410 return 1;
411
412 if (validate_encoding(path, enc, src, src_len, die_on_error))
413 return 0;
414
415 trace_encoding("source", path, enc, src, src_len);
416 dst = reencode_string_len(src, src_len, default_encoding, enc,
417 &dst_len);
418 if (!dst) {
419 /*
420 * We could add the blob "as-is" to Git. However, on checkout
421 * we would try to reencode to the original encoding. This
422 * would fail and we would leave the user with a messed-up
423 * working tree. Let's try to avoid this by screaming loud.
424 */
425 const char* msg = _("failed to encode '%s' from %s to %s");
426 if (die_on_error)
427 die(msg, path, enc, default_encoding);
428 else {
429 error(msg, path, enc, default_encoding);
430 return 0;
431 }
432 }
433 trace_encoding("destination", path, default_encoding, dst, dst_len);
434
435 /*
436 * UTF supports lossless conversion round tripping [1] and conversions
437 * between UTF and other encodings are mostly round trip safe as
438 * Unicode aims to be a superset of all other character encodings.
439 * However, certain encodings (e.g. SHIFT-JIS) are known to have round
440 * trip issues [2]. Check the round trip conversion for all encodings
441 * listed in core.checkRoundtripEncoding.
442 *
443 * The round trip check is only performed if content is written to Git.
444 * This ensures that no information is lost during conversion to/from
445 * the internal UTF-8 representation.
446 *
447 * Please note, the code below is not tested because I was not able to
448 * generate a faulty round trip without an iconv error. Iconv errors
449 * are already caught above.
450 *
451 * [1] http://unicode.org/faq/utf_bom.html#gen2
452 * [2] https://support.microsoft.com/en-us/help/170559/prb-conversion-problem-between-shift-jis-and-unicode
453 */
454 if (die_on_error && check_roundtrip(enc)) {
455 char *re_src;
456 size_t re_src_len;
457
458 re_src = reencode_string_len(dst, dst_len,
459 enc, default_encoding,
460 &re_src_len);
461
462 trace_printf("Checking roundtrip encoding for %s...\n", enc);
463 trace_encoding("reencoded source", path, enc,
464 re_src, re_src_len);
465
466 if (!re_src || src_len != re_src_len ||
467 memcmp(src, re_src, src_len)) {
468 const char* msg = _("encoding '%s' from %s to %s and "
469 "back is not the same");
470 die(msg, path, enc, default_encoding);
471 }
472
473 free(re_src);
474 }
475
476 strbuf_attach(buf, dst, dst_len, dst_len + 1);
477 return 1;
478 }
479
480 static int encode_to_worktree(const char *path, const char *src, size_t src_len,
481 struct strbuf *buf, const char *enc)
482 {
483 char *dst;
484 size_t dst_len;
485
486 /*
487 * No encoding is specified or there is nothing to encode.
488 * Tell the caller that the content was not modified.
489 */
490 if (!enc || (src && !src_len))
491 return 0;
492
493 dst = reencode_string_len(src, src_len, enc, default_encoding,
494 &dst_len);
495 if (!dst) {
496 error(_("failed to encode '%s' from %s to %s"),
497 path, default_encoding, enc);
498 return 0;
499 }
500
501 strbuf_attach(buf, dst, dst_len, dst_len + 1);
502 return 1;
503 }
504
505 static int crlf_to_git(const struct index_state *istate,
506 const char *path, const char *src, size_t len,
507 struct strbuf *buf,
508 enum crlf_action crlf_action, int conv_flags)
509 {
510 struct text_stat stats;
511 char *dst;
512 int convert_crlf_into_lf;
513
514 if (crlf_action == CRLF_BINARY ||
515 (src && !len))
516 return 0;
517
518 /*
519 * If we are doing a dry-run and have no source buffer, there is
520 * nothing to analyze; we must assume we would convert.
521 */
522 if (!buf && !src)
523 return 1;
524
525 gather_stats(src, len, &stats);
526 /* Optimization: No CRLF? Nothing to convert, regardless. */
527 convert_crlf_into_lf = !!stats.crlf;
528
529 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
530 if (convert_is_binary(len, &stats))
531 return 0;
532 /*
533 * If the file in the index has any CR in it, do not
534 * convert. This is the new safer autocrlf handling,
535 * unless we want to renormalize in a merge or
536 * cherry-pick.
537 */
538 if ((!(conv_flags & CONV_EOL_RENORMALIZE)) &&
539 has_crlf_in_index(istate, path))
540 convert_crlf_into_lf = 0;
541 }
542 if (((conv_flags & CONV_EOL_RNDTRP_WARN) ||
543 ((conv_flags & CONV_EOL_RNDTRP_DIE) && len))) {
544 struct text_stat new_stats;
545 memcpy(&new_stats, &stats, sizeof(new_stats));
546 /* simulate "git add" */
547 if (convert_crlf_into_lf) {
548 new_stats.lonelf += new_stats.crlf;
549 new_stats.crlf = 0;
550 }
551 /* simulate "git checkout" */
552 if (will_convert_lf_to_crlf(len, &new_stats, crlf_action)) {
553 new_stats.crlf += new_stats.lonelf;
554 new_stats.lonelf = 0;
555 }
556 check_global_conv_flags_eol(path, crlf_action, &stats, &new_stats, conv_flags);
557 }
558 if (!convert_crlf_into_lf)
559 return 0;
560
561 /*
562 * At this point all of our source analysis is done, and we are sure we
563 * would convert. If we are in dry-run mode, we can give an answer.
564 */
565 if (!buf)
566 return 1;
567
568 /* only grow if not in place */
569 if (strbuf_avail(buf) + buf->len < len)
570 strbuf_grow(buf, len - buf->len);
571 dst = buf->buf;
572 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
573 /*
574 * If we guessed, we already know we rejected a file with
575 * lone CR, and we can strip a CR without looking at what
576 * follow it.
577 */
578 do {
579 unsigned char c = *src++;
580 if (c != '\r')
581 *dst++ = c;
582 } while (--len);
583 } else {
584 do {
585 unsigned char c = *src++;
586 if (! (c == '\r' && (1 < len && *src == '\n')))
587 *dst++ = c;
588 } while (--len);
589 }
590 strbuf_setlen(buf, dst - buf->buf);
591 return 1;
592 }
593
594 static int crlf_to_worktree(const char *path, const char *src, size_t len,
595 struct strbuf *buf, enum crlf_action crlf_action)
596 {
597 char *to_free = NULL;
598 struct text_stat stats;
599
600 if (!len || output_eol(crlf_action) != EOL_CRLF)
601 return 0;
602
603 gather_stats(src, len, &stats);
604 if (!will_convert_lf_to_crlf(len, &stats, crlf_action))
605 return 0;
606
607 /* are we "faking" in place editing ? */
608 if (src == buf->buf)
609 to_free = strbuf_detach(buf, NULL);
610
611 strbuf_grow(buf, len + stats.lonelf);
612 for (;;) {
613 const char *nl = memchr(src, '\n', len);
614 if (!nl)
615 break;
616 if (nl > src && nl[-1] == '\r') {
617 strbuf_add(buf, src, nl + 1 - src);
618 } else {
619 strbuf_add(buf, src, nl - src);
620 strbuf_addstr(buf, "\r\n");
621 }
622 len -= nl + 1 - src;
623 src = nl + 1;
624 }
625 strbuf_add(buf, src, len);
626
627 free(to_free);
628 return 1;
629 }
630
631 struct filter_params {
632 const char *src;
633 unsigned long size;
634 int fd;
635 const char *cmd;
636 const char *path;
637 };
638
639 static int filter_buffer_or_fd(int in, int out, void *data)
640 {
641 /*
642 * Spawn cmd and feed the buffer contents through its stdin.
643 */
644 struct child_process child_process = CHILD_PROCESS_INIT;
645 struct filter_params *params = (struct filter_params *)data;
646 int write_err, status;
647 const char *argv[] = { NULL, NULL };
648
649 /* apply % substitution to cmd */
650 struct strbuf cmd = STRBUF_INIT;
651 struct strbuf path = STRBUF_INIT;
652 struct strbuf_expand_dict_entry dict[] = {
653 { "f", NULL, },
654 { NULL, NULL, },
655 };
656
657 /* quote the path to preserve spaces, etc. */
658 sq_quote_buf(&path, params->path);
659 dict[0].value = path.buf;
660
661 /* expand all %f with the quoted path */
662 strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
663 strbuf_release(&path);
664
665 argv[0] = cmd.buf;
666
667 child_process.argv = argv;
668 child_process.use_shell = 1;
669 child_process.in = -1;
670 child_process.out = out;
671
672 if (start_command(&child_process)) {
673 strbuf_release(&cmd);
674 return error(_("cannot fork to run external filter '%s'"),
675 params->cmd);
676 }
677
678 sigchain_push(SIGPIPE, SIG_IGN);
679
680 if (params->src) {
681 write_err = (write_in_full(child_process.in,
682 params->src, params->size) < 0);
683 if (errno == EPIPE)
684 write_err = 0;
685 } else {
686 write_err = copy_fd(params->fd, child_process.in);
687 if (write_err == COPY_WRITE_ERROR && errno == EPIPE)
688 write_err = 0;
689 }
690
691 if (close(child_process.in))
692 write_err = 1;
693 if (write_err)
694 error(_("cannot feed the input to external filter '%s'"),
695 params->cmd);
696
697 sigchain_pop(SIGPIPE);
698
699 status = finish_command(&child_process);
700 if (status)
701 error(_("external filter '%s' failed %d"), params->cmd, status);
702
703 strbuf_release(&cmd);
704 return (write_err || status);
705 }
706
707 static int apply_single_file_filter(const char *path, const char *src, size_t len, int fd,
708 struct strbuf *dst, const char *cmd)
709 {
710 /*
711 * Create a pipeline to have the command filter the buffer's
712 * contents.
713 *
714 * (child --> cmd) --> us
715 */
716 int err = 0;
717 struct strbuf nbuf = STRBUF_INIT;
718 struct async async;
719 struct filter_params params;
720
721 memset(&async, 0, sizeof(async));
722 async.proc = filter_buffer_or_fd;
723 async.data = &params;
724 async.out = -1;
725 params.src = src;
726 params.size = len;
727 params.fd = fd;
728 params.cmd = cmd;
729 params.path = path;
730
731 fflush(NULL);
732 if (start_async(&async))
733 return 0; /* error was already reported */
734
735 if (strbuf_read(&nbuf, async.out, len) < 0) {
736 err = error(_("read from external filter '%s' failed"), cmd);
737 }
738 if (close(async.out)) {
739 err = error(_("read from external filter '%s' failed"), cmd);
740 }
741 if (finish_async(&async)) {
742 err = error(_("external filter '%s' failed"), cmd);
743 }
744
745 if (!err) {
746 strbuf_swap(dst, &nbuf);
747 }
748 strbuf_release(&nbuf);
749 return !err;
750 }
751
752 #define CAP_CLEAN (1u<<0)
753 #define CAP_SMUDGE (1u<<1)
754 #define CAP_DELAY (1u<<2)
755
756 struct cmd2process {
757 struct subprocess_entry subprocess; /* must be the first member! */
758 unsigned int supported_capabilities;
759 };
760
761 static int subprocess_map_initialized;
762 static struct hashmap subprocess_map;
763
764 static int start_multi_file_filter_fn(struct subprocess_entry *subprocess)
765 {
766 static int versions[] = {2, 0};
767 static struct subprocess_capability capabilities[] = {
768 { "clean", CAP_CLEAN },
769 { "smudge", CAP_SMUDGE },
770 { "delay", CAP_DELAY },
771 { NULL, 0 }
772 };
773 struct cmd2process *entry = (struct cmd2process *)subprocess;
774 return subprocess_handshake(subprocess, "git-filter", versions, NULL,
775 capabilities,
776 &entry->supported_capabilities);
777 }
778
779 static void handle_filter_error(const struct strbuf *filter_status,
780 struct cmd2process *entry,
781 const unsigned int wanted_capability) {
782 if (!strcmp(filter_status->buf, "error"))
783 ; /* The filter signaled a problem with the file. */
784 else if (!strcmp(filter_status->buf, "abort") && wanted_capability) {
785 /*
786 * The filter signaled a permanent problem. Don't try to filter
787 * files with the same command for the lifetime of the current
788 * Git process.
789 */
790 entry->supported_capabilities &= ~wanted_capability;
791 } else {
792 /*
793 * Something went wrong with the protocol filter.
794 * Force shutdown and restart if another blob requires filtering.
795 */
796 error(_("external filter '%s' failed"), entry->subprocess.cmd);
797 subprocess_stop(&subprocess_map, &entry->subprocess);
798 free(entry);
799 }
800 }
801
802 static int apply_multi_file_filter(const char *path, const char *src, size_t len,
803 int fd, struct strbuf *dst, const char *cmd,
804 const unsigned int wanted_capability,
805 struct delayed_checkout *dco)
806 {
807 int err;
808 int can_delay = 0;
809 struct cmd2process *entry;
810 struct child_process *process;
811 struct strbuf nbuf = STRBUF_INIT;
812 struct strbuf filter_status = STRBUF_INIT;
813 const char *filter_type;
814
815 if (!subprocess_map_initialized) {
816 subprocess_map_initialized = 1;
817 hashmap_init(&subprocess_map, cmd2process_cmp, NULL, 0);
818 entry = NULL;
819 } else {
820 entry = (struct cmd2process *)subprocess_find_entry(&subprocess_map, cmd);
821 }
822
823 fflush(NULL);
824
825 if (!entry) {
826 entry = xmalloc(sizeof(*entry));
827 entry->supported_capabilities = 0;
828
829 if (subprocess_start(&subprocess_map, &entry->subprocess, cmd, start_multi_file_filter_fn)) {
830 free(entry);
831 return 0;
832 }
833 }
834 process = &entry->subprocess.process;
835
836 if (!(entry->supported_capabilities & wanted_capability))
837 return 0;
838
839 if (wanted_capability & CAP_CLEAN)
840 filter_type = "clean";
841 else if (wanted_capability & CAP_SMUDGE)
842 filter_type = "smudge";
843 else
844 die(_("unexpected filter type"));
845
846 sigchain_push(SIGPIPE, SIG_IGN);
847
848 assert(strlen(filter_type) < LARGE_PACKET_DATA_MAX - strlen("command=\n"));
849 err = packet_write_fmt_gently(process->in, "command=%s\n", filter_type);
850 if (err)
851 goto done;
852
853 err = strlen(path) > LARGE_PACKET_DATA_MAX - strlen("pathname=\n");
854 if (err) {
855 error(_("path name too long for external filter"));
856 goto done;
857 }
858
859 err = packet_write_fmt_gently(process->in, "pathname=%s\n", path);
860 if (err)
861 goto done;
862
863 if ((entry->supported_capabilities & CAP_DELAY) &&
864 dco && dco->state == CE_CAN_DELAY) {
865 can_delay = 1;
866 err = packet_write_fmt_gently(process->in, "can-delay=1\n");
867 if (err)
868 goto done;
869 }
870
871 err = packet_flush_gently(process->in);
872 if (err)
873 goto done;
874
875 if (fd >= 0)
876 err = write_packetized_from_fd(fd, process->in);
877 else
878 err = write_packetized_from_buf(src, len, process->in);
879 if (err)
880 goto done;
881
882 err = subprocess_read_status(process->out, &filter_status);
883 if (err)
884 goto done;
885
886 if (can_delay && !strcmp(filter_status.buf, "delayed")) {
887 string_list_insert(&dco->filters, cmd);
888 string_list_insert(&dco->paths, path);
889 } else {
890 /* The filter got the blob and wants to send us a response. */
891 err = strcmp(filter_status.buf, "success");
892 if (err)
893 goto done;
894
895 err = read_packetized_to_strbuf(process->out, &nbuf) < 0;
896 if (err)
897 goto done;
898
899 err = subprocess_read_status(process->out, &filter_status);
900 if (err)
901 goto done;
902
903 err = strcmp(filter_status.buf, "success");
904 }
905
906 done:
907 sigchain_pop(SIGPIPE);
908
909 if (err)
910 handle_filter_error(&filter_status, entry, wanted_capability);
911 else
912 strbuf_swap(dst, &nbuf);
913 strbuf_release(&nbuf);
914 return !err;
915 }
916
917
918 int async_query_available_blobs(const char *cmd, struct string_list *available_paths)
919 {
920 int err;
921 char *line;
922 struct cmd2process *entry;
923 struct child_process *process;
924 struct strbuf filter_status = STRBUF_INIT;
925
926 assert(subprocess_map_initialized);
927 entry = (struct cmd2process *)subprocess_find_entry(&subprocess_map, cmd);
928 if (!entry) {
929 error(_("external filter '%s' is not available anymore although "
930 "not all paths have been filtered"), cmd);
931 return 0;
932 }
933 process = &entry->subprocess.process;
934 sigchain_push(SIGPIPE, SIG_IGN);
935
936 err = packet_write_fmt_gently(
937 process->in, "command=list_available_blobs\n");
938 if (err)
939 goto done;
940
941 err = packet_flush_gently(process->in);
942 if (err)
943 goto done;
944
945 while ((line = packet_read_line(process->out, NULL))) {
946 const char *path;
947 if (skip_prefix(line, "pathname=", &path))
948 string_list_insert(available_paths, xstrdup(path));
949 else
950 ; /* ignore unknown keys */
951 }
952
953 err = subprocess_read_status(process->out, &filter_status);
954 if (err)
955 goto done;
956
957 err = strcmp(filter_status.buf, "success");
958
959 done:
960 sigchain_pop(SIGPIPE);
961
962 if (err)
963 handle_filter_error(&filter_status, entry, 0);
964 return !err;
965 }
966
967 static struct convert_driver {
968 const char *name;
969 struct convert_driver *next;
970 const char *smudge;
971 const char *clean;
972 const char *process;
973 int required;
974 } *user_convert, **user_convert_tail;
975
976 static int apply_filter(const char *path, const char *src, size_t len,
977 int fd, struct strbuf *dst, struct convert_driver *drv,
978 const unsigned int wanted_capability,
979 struct delayed_checkout *dco)
980 {
981 const char *cmd = NULL;
982
983 if (!drv)
984 return 0;
985
986 if (!dst)
987 return 1;
988
989 if ((wanted_capability & CAP_CLEAN) && !drv->process && drv->clean)
990 cmd = drv->clean;
991 else if ((wanted_capability & CAP_SMUDGE) && !drv->process && drv->smudge)
992 cmd = drv->smudge;
993
994 if (cmd && *cmd)
995 return apply_single_file_filter(path, src, len, fd, dst, cmd);
996 else if (drv->process && *drv->process)
997 return apply_multi_file_filter(path, src, len, fd, dst,
998 drv->process, wanted_capability, dco);
999
1000 return 0;
1001 }
1002
1003 static int read_convert_config(const char *var, const char *value, void *cb)
1004 {
1005 const char *key, *name;
1006 int namelen;
1007 struct convert_driver *drv;
1008
1009 /*
1010 * External conversion drivers are configured using
1011 * "filter.<name>.variable".
1012 */
1013 if (parse_config_key(var, "filter", &name, &namelen, &key) < 0 || !name)
1014 return 0;
1015 for (drv = user_convert; drv; drv = drv->next)
1016 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
1017 break;
1018 if (!drv) {
1019 drv = xcalloc(1, sizeof(struct convert_driver));
1020 drv->name = xmemdupz(name, namelen);
1021 *user_convert_tail = drv;
1022 user_convert_tail = &(drv->next);
1023 }
1024
1025 /*
1026 * filter.<name>.smudge and filter.<name>.clean specifies
1027 * the command line:
1028 *
1029 * command-line
1030 *
1031 * The command-line will not be interpolated in any way.
1032 */
1033
1034 if (!strcmp("smudge", key))
1035 return git_config_string(&drv->smudge, var, value);
1036
1037 if (!strcmp("clean", key))
1038 return git_config_string(&drv->clean, var, value);
1039
1040 if (!strcmp("process", key))
1041 return git_config_string(&drv->process, var, value);
1042
1043 if (!strcmp("required", key)) {
1044 drv->required = git_config_bool(var, value);
1045 return 0;
1046 }
1047
1048 return 0;
1049 }
1050
1051 static int count_ident(const char *cp, unsigned long size)
1052 {
1053 /*
1054 * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
1055 */
1056 int cnt = 0;
1057 char ch;
1058
1059 while (size) {
1060 ch = *cp++;
1061 size--;
1062 if (ch != '$')
1063 continue;
1064 if (size < 3)
1065 break;
1066 if (memcmp("Id", cp, 2))
1067 continue;
1068 ch = cp[2];
1069 cp += 3;
1070 size -= 3;
1071 if (ch == '$')
1072 cnt++; /* $Id$ */
1073 if (ch != ':')
1074 continue;
1075
1076 /*
1077 * "$Id: ... "; scan up to the closing dollar sign and discard.
1078 */
1079 while (size) {
1080 ch = *cp++;
1081 size--;
1082 if (ch == '$') {
1083 cnt++;
1084 break;
1085 }
1086 if (ch == '\n')
1087 break;
1088 }
1089 }
1090 return cnt;
1091 }
1092
1093 static int ident_to_git(const char *path, const char *src, size_t len,
1094 struct strbuf *buf, int ident)
1095 {
1096 char *dst, *dollar;
1097
1098 if (!ident || (src && !count_ident(src, len)))
1099 return 0;
1100
1101 if (!buf)
1102 return 1;
1103
1104 /* only grow if not in place */
1105 if (strbuf_avail(buf) + buf->len < len)
1106 strbuf_grow(buf, len - buf->len);
1107 dst = buf->buf;
1108 for (;;) {
1109 dollar = memchr(src, '$', len);
1110 if (!dollar)
1111 break;
1112 memmove(dst, src, dollar + 1 - src);
1113 dst += dollar + 1 - src;
1114 len -= dollar + 1 - src;
1115 src = dollar + 1;
1116
1117 if (len > 3 && !memcmp(src, "Id:", 3)) {
1118 dollar = memchr(src + 3, '$', len - 3);
1119 if (!dollar)
1120 break;
1121 if (memchr(src + 3, '\n', dollar - src - 3)) {
1122 /* Line break before the next dollar. */
1123 continue;
1124 }
1125
1126 memcpy(dst, "Id$", 3);
1127 dst += 3;
1128 len -= dollar + 1 - src;
1129 src = dollar + 1;
1130 }
1131 }
1132 memmove(dst, src, len);
1133 strbuf_setlen(buf, dst + len - buf->buf);
1134 return 1;
1135 }
1136
1137 static int ident_to_worktree(const char *path, const char *src, size_t len,
1138 struct strbuf *buf, int ident)
1139 {
1140 struct object_id oid;
1141 char *to_free = NULL, *dollar, *spc;
1142 int cnt;
1143
1144 if (!ident)
1145 return 0;
1146
1147 cnt = count_ident(src, len);
1148 if (!cnt)
1149 return 0;
1150
1151 /* are we "faking" in place editing ? */
1152 if (src == buf->buf)
1153 to_free = strbuf_detach(buf, NULL);
1154 hash_object_file(src, len, "blob", &oid);
1155
1156 strbuf_grow(buf, len + cnt * (the_hash_algo->hexsz + 3));
1157 for (;;) {
1158 /* step 1: run to the next '$' */
1159 dollar = memchr(src, '$', len);
1160 if (!dollar)
1161 break;
1162 strbuf_add(buf, src, dollar + 1 - src);
1163 len -= dollar + 1 - src;
1164 src = dollar + 1;
1165
1166 /* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */
1167 if (len < 3 || memcmp("Id", src, 2))
1168 continue;
1169
1170 /* step 3: skip over Id$ or Id:xxxxx$ */
1171 if (src[2] == '$') {
1172 src += 3;
1173 len -= 3;
1174 } else if (src[2] == ':') {
1175 /*
1176 * It's possible that an expanded Id has crept its way into the
1177 * repository, we cope with that by stripping the expansion out.
1178 * This is probably not a good idea, since it will cause changes
1179 * on checkout, which won't go away by stash, but let's keep it
1180 * for git-style ids.
1181 */
1182 dollar = memchr(src + 3, '$', len - 3);
1183 if (!dollar) {
1184 /* incomplete keyword, no more '$', so just quit the loop */
1185 break;
1186 }
1187
1188 if (memchr(src + 3, '\n', dollar - src - 3)) {
1189 /* Line break before the next dollar. */
1190 continue;
1191 }
1192
1193 spc = memchr(src + 4, ' ', dollar - src - 4);
1194 if (spc && spc < dollar-1) {
1195 /* There are spaces in unexpected places.
1196 * This is probably an id from some other
1197 * versioning system. Keep it for now.
1198 */
1199 continue;
1200 }
1201
1202 len -= dollar + 1 - src;
1203 src = dollar + 1;
1204 } else {
1205 /* it wasn't a "Id$" or "Id:xxxx$" */
1206 continue;
1207 }
1208
1209 /* step 4: substitute */
1210 strbuf_addstr(buf, "Id: ");
1211 strbuf_addstr(buf, oid_to_hex(&oid));
1212 strbuf_addstr(buf, " $");
1213 }
1214 strbuf_add(buf, src, len);
1215
1216 free(to_free);
1217 return 1;
1218 }
1219
1220 static const char *git_path_check_encoding(struct attr_check_item *check)
1221 {
1222 const char *value = check->value;
1223
1224 if (ATTR_UNSET(value) || !strlen(value))
1225 return NULL;
1226
1227 if (ATTR_TRUE(value) || ATTR_FALSE(value)) {
1228 die(_("true/false are no valid working-tree-encodings"));
1229 }
1230
1231 /* Don't encode to the default encoding */
1232 if (same_encoding(value, default_encoding))
1233 return NULL;
1234
1235 return value;
1236 }
1237
1238 static enum crlf_action git_path_check_crlf(struct attr_check_item *check)
1239 {
1240 const char *value = check->value;
1241
1242 if (ATTR_TRUE(value))
1243 return CRLF_TEXT;
1244 else if (ATTR_FALSE(value))
1245 return CRLF_BINARY;
1246 else if (ATTR_UNSET(value))
1247 ;
1248 else if (!strcmp(value, "input"))
1249 return CRLF_TEXT_INPUT;
1250 else if (!strcmp(value, "auto"))
1251 return CRLF_AUTO;
1252 return CRLF_UNDEFINED;
1253 }
1254
1255 static enum eol git_path_check_eol(struct attr_check_item *check)
1256 {
1257 const char *value = check->value;
1258
1259 if (ATTR_UNSET(value))
1260 ;
1261 else if (!strcmp(value, "lf"))
1262 return EOL_LF;
1263 else if (!strcmp(value, "crlf"))
1264 return EOL_CRLF;
1265 return EOL_UNSET;
1266 }
1267
1268 static struct convert_driver *git_path_check_convert(struct attr_check_item *check)
1269 {
1270 const char *value = check->value;
1271 struct convert_driver *drv;
1272
1273 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1274 return NULL;
1275 for (drv = user_convert; drv; drv = drv->next)
1276 if (!strcmp(value, drv->name))
1277 return drv;
1278 return NULL;
1279 }
1280
1281 static int git_path_check_ident(struct attr_check_item *check)
1282 {
1283 const char *value = check->value;
1284
1285 return !!ATTR_TRUE(value);
1286 }
1287
1288 struct conv_attrs {
1289 struct convert_driver *drv;
1290 enum crlf_action attr_action; /* What attr says */
1291 enum crlf_action crlf_action; /* When no attr is set, use core.autocrlf */
1292 int ident;
1293 const char *working_tree_encoding; /* Supported encoding or default encoding if NULL */
1294 };
1295
1296 static void convert_attrs(const struct index_state *istate,
1297 struct conv_attrs *ca, const char *path)
1298 {
1299 static struct attr_check *check;
1300
1301 if (!check) {
1302 check = attr_check_initl("crlf", "ident", "filter",
1303 "eol", "text", "working-tree-encoding",
1304 NULL);
1305 user_convert_tail = &user_convert;
1306 git_config(read_convert_config, NULL);
1307 }
1308
1309 if (!git_check_attr(istate, path, check)) {
1310 struct attr_check_item *ccheck = check->items;
1311 ca->crlf_action = git_path_check_crlf(ccheck + 4);
1312 if (ca->crlf_action == CRLF_UNDEFINED)
1313 ca->crlf_action = git_path_check_crlf(ccheck + 0);
1314 ca->ident = git_path_check_ident(ccheck + 1);
1315 ca->drv = git_path_check_convert(ccheck + 2);
1316 if (ca->crlf_action != CRLF_BINARY) {
1317 enum eol eol_attr = git_path_check_eol(ccheck + 3);
1318 if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_LF)
1319 ca->crlf_action = CRLF_AUTO_INPUT;
1320 else if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_CRLF)
1321 ca->crlf_action = CRLF_AUTO_CRLF;
1322 else if (eol_attr == EOL_LF)
1323 ca->crlf_action = CRLF_TEXT_INPUT;
1324 else if (eol_attr == EOL_CRLF)
1325 ca->crlf_action = CRLF_TEXT_CRLF;
1326 }
1327 ca->working_tree_encoding = git_path_check_encoding(ccheck + 5);
1328 } else {
1329 ca->drv = NULL;
1330 ca->crlf_action = CRLF_UNDEFINED;
1331 ca->ident = 0;
1332 }
1333
1334 /* Save attr and make a decision for action */
1335 ca->attr_action = ca->crlf_action;
1336 if (ca->crlf_action == CRLF_TEXT)
1337 ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT;
1338 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE)
1339 ca->crlf_action = CRLF_BINARY;
1340 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_TRUE)
1341 ca->crlf_action = CRLF_AUTO_CRLF;
1342 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_INPUT)
1343 ca->crlf_action = CRLF_AUTO_INPUT;
1344 }
1345
1346 int would_convert_to_git_filter_fd(const struct index_state *istate, const char *path)
1347 {
1348 struct conv_attrs ca;
1349
1350 convert_attrs(istate, &ca, path);
1351 if (!ca.drv)
1352 return 0;
1353
1354 /*
1355 * Apply a filter to an fd only if the filter is required to succeed.
1356 * We must die if the filter fails, because the original data before
1357 * filtering is not available.
1358 */
1359 if (!ca.drv->required)
1360 return 0;
1361
1362 return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL);
1363 }
1364
1365 const char *get_convert_attr_ascii(const struct index_state *istate, const char *path)
1366 {
1367 struct conv_attrs ca;
1368
1369 convert_attrs(istate, &ca, path);
1370 switch (ca.attr_action) {
1371 case CRLF_UNDEFINED:
1372 return "";
1373 case CRLF_BINARY:
1374 return "-text";
1375 case CRLF_TEXT:
1376 return "text";
1377 case CRLF_TEXT_INPUT:
1378 return "text eol=lf";
1379 case CRLF_TEXT_CRLF:
1380 return "text eol=crlf";
1381 case CRLF_AUTO:
1382 return "text=auto";
1383 case CRLF_AUTO_CRLF:
1384 return "text=auto eol=crlf";
1385 case CRLF_AUTO_INPUT:
1386 return "text=auto eol=lf";
1387 }
1388 return "";
1389 }
1390
1391 int convert_to_git(const struct index_state *istate,
1392 const char *path, const char *src, size_t len,
1393 struct strbuf *dst, int conv_flags)
1394 {
1395 int ret = 0;
1396 struct conv_attrs ca;
1397
1398 convert_attrs(istate, &ca, path);
1399
1400 ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL);
1401 if (!ret && ca.drv && ca.drv->required)
1402 die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
1403
1404 if (ret && dst) {
1405 src = dst->buf;
1406 len = dst->len;
1407 }
1408
1409 ret |= encode_to_git(path, src, len, dst, ca.working_tree_encoding, conv_flags);
1410 if (ret && dst) {
1411 src = dst->buf;
1412 len = dst->len;
1413 }
1414
1415 if (!(conv_flags & CONV_EOL_KEEP_CRLF)) {
1416 ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, conv_flags);
1417 if (ret && dst) {
1418 src = dst->buf;
1419 len = dst->len;
1420 }
1421 }
1422 return ret | ident_to_git(path, src, len, dst, ca.ident);
1423 }
1424
1425 void convert_to_git_filter_fd(const struct index_state *istate,
1426 const char *path, int fd, struct strbuf *dst,
1427 int conv_flags)
1428 {
1429 struct conv_attrs ca;
1430 convert_attrs(istate, &ca, path);
1431
1432 assert(ca.drv);
1433 assert(ca.drv->clean || ca.drv->process);
1434
1435 if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL))
1436 die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
1437
1438 encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
1439 crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, conv_flags);
1440 ident_to_git(path, dst->buf, dst->len, dst, ca.ident);
1441 }
1442
1443 static int convert_to_working_tree_internal(const struct index_state *istate,
1444 const char *path, const char *src,
1445 size_t len, struct strbuf *dst,
1446 int normalizing, struct delayed_checkout *dco)
1447 {
1448 int ret = 0, ret_filter = 0;
1449 struct conv_attrs ca;
1450
1451 convert_attrs(istate, &ca, path);
1452
1453 ret |= ident_to_worktree(path, src, len, dst, ca.ident);
1454 if (ret) {
1455 src = dst->buf;
1456 len = dst->len;
1457 }
1458 /*
1459 * CRLF conversion can be skipped if normalizing, unless there
1460 * is a smudge or process filter (even if the process filter doesn't
1461 * support smudge). The filters might expect CRLFs.
1462 */
1463 if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) {
1464 ret |= crlf_to_worktree(path, src, len, dst, ca.crlf_action);
1465 if (ret) {
1466 src = dst->buf;
1467 len = dst->len;
1468 }
1469 }
1470
1471 ret |= encode_to_worktree(path, src, len, dst, ca.working_tree_encoding);
1472 if (ret) {
1473 src = dst->buf;
1474 len = dst->len;
1475 }
1476
1477 ret_filter = apply_filter(
1478 path, src, len, -1, dst, ca.drv, CAP_SMUDGE, dco);
1479 if (!ret_filter && ca.drv && ca.drv->required)
1480 die(_("%s: smudge filter %s failed"), path, ca.drv->name);
1481
1482 return ret | ret_filter;
1483 }
1484
1485 int async_convert_to_working_tree(const struct index_state *istate,
1486 const char *path, const char *src,
1487 size_t len, struct strbuf *dst,
1488 void *dco)
1489 {
1490 return convert_to_working_tree_internal(istate, path, src, len, dst, 0, dco);
1491 }
1492
1493 int convert_to_working_tree(const struct index_state *istate,
1494 const char *path, const char *src,
1495 size_t len, struct strbuf *dst)
1496 {
1497 return convert_to_working_tree_internal(istate, path, src, len, dst, 0, NULL);
1498 }
1499
1500 int renormalize_buffer(const struct index_state *istate, const char *path,
1501 const char *src, size_t len, struct strbuf *dst)
1502 {
1503 int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL);
1504 if (ret) {
1505 src = dst->buf;
1506 len = dst->len;
1507 }
1508 return ret | convert_to_git(istate, path, src, len, dst, CONV_EOL_RENORMALIZE);
1509 }
1510
1511 /*****************************************************************
1512 *
1513 * Streaming conversion support
1514 *
1515 *****************************************************************/
1516
1517 typedef int (*filter_fn)(struct stream_filter *,
1518 const char *input, size_t *isize_p,
1519 char *output, size_t *osize_p);
1520 typedef void (*free_fn)(struct stream_filter *);
1521
1522 struct stream_filter_vtbl {
1523 filter_fn filter;
1524 free_fn free;
1525 };
1526
1527 struct stream_filter {
1528 struct stream_filter_vtbl *vtbl;
1529 };
1530
1531 static int null_filter_fn(struct stream_filter *filter,
1532 const char *input, size_t *isize_p,
1533 char *output, size_t *osize_p)
1534 {
1535 size_t count;
1536
1537 if (!input)
1538 return 0; /* we do not keep any states */
1539 count = *isize_p;
1540 if (*osize_p < count)
1541 count = *osize_p;
1542 if (count) {
1543 memmove(output, input, count);
1544 *isize_p -= count;
1545 *osize_p -= count;
1546 }
1547 return 0;
1548 }
1549
1550 static void null_free_fn(struct stream_filter *filter)
1551 {
1552 ; /* nothing -- null instances are shared */
1553 }
1554
1555 static struct stream_filter_vtbl null_vtbl = {
1556 null_filter_fn,
1557 null_free_fn,
1558 };
1559
1560 static struct stream_filter null_filter_singleton = {
1561 &null_vtbl,
1562 };
1563
1564 int is_null_stream_filter(struct stream_filter *filter)
1565 {
1566 return filter == &null_filter_singleton;
1567 }
1568
1569
1570 /*
1571 * LF-to-CRLF filter
1572 */
1573
1574 struct lf_to_crlf_filter {
1575 struct stream_filter filter;
1576 unsigned has_held:1;
1577 char held;
1578 };
1579
1580 static int lf_to_crlf_filter_fn(struct stream_filter *filter,
1581 const char *input, size_t *isize_p,
1582 char *output, size_t *osize_p)
1583 {
1584 size_t count, o = 0;
1585 struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter;
1586
1587 /*
1588 * We may be holding onto the CR to see if it is followed by a
1589 * LF, in which case we would need to go to the main loop.
1590 * Otherwise, just emit it to the output stream.
1591 */
1592 if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) {
1593 output[o++] = lf_to_crlf->held;
1594 lf_to_crlf->has_held = 0;
1595 }
1596
1597 /* We are told to drain */
1598 if (!input) {
1599 *osize_p -= o;
1600 return 0;
1601 }
1602
1603 count = *isize_p;
1604 if (count || lf_to_crlf->has_held) {
1605 size_t i;
1606 int was_cr = 0;
1607
1608 if (lf_to_crlf->has_held) {
1609 was_cr = 1;
1610 lf_to_crlf->has_held = 0;
1611 }
1612
1613 for (i = 0; o < *osize_p && i < count; i++) {
1614 char ch = input[i];
1615
1616 if (ch == '\n') {
1617 output[o++] = '\r';
1618 } else if (was_cr) {
1619 /*
1620 * Previous round saw CR and it is not followed
1621 * by a LF; emit the CR before processing the
1622 * current character.
1623 */
1624 output[o++] = '\r';
1625 }
1626
1627 /*
1628 * We may have consumed the last output slot,
1629 * in which case we need to break out of this
1630 * loop; hold the current character before
1631 * returning.
1632 */
1633 if (*osize_p <= o) {
1634 lf_to_crlf->has_held = 1;
1635 lf_to_crlf->held = ch;
1636 continue; /* break but increment i */
1637 }
1638
1639 if (ch == '\r') {
1640 was_cr = 1;
1641 continue;
1642 }
1643
1644 was_cr = 0;
1645 output[o++] = ch;
1646 }
1647
1648 *osize_p -= o;
1649 *isize_p -= i;
1650
1651 if (!lf_to_crlf->has_held && was_cr) {
1652 lf_to_crlf->has_held = 1;
1653 lf_to_crlf->held = '\r';
1654 }
1655 }
1656 return 0;
1657 }
1658
1659 static void lf_to_crlf_free_fn(struct stream_filter *filter)
1660 {
1661 free(filter);
1662 }
1663
1664 static struct stream_filter_vtbl lf_to_crlf_vtbl = {
1665 lf_to_crlf_filter_fn,
1666 lf_to_crlf_free_fn,
1667 };
1668
1669 static struct stream_filter *lf_to_crlf_filter(void)
1670 {
1671 struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf));
1672
1673 lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl;
1674 return (struct stream_filter *)lf_to_crlf;
1675 }
1676
1677 /*
1678 * Cascade filter
1679 */
1680 #define FILTER_BUFFER 1024
1681 struct cascade_filter {
1682 struct stream_filter filter;
1683 struct stream_filter *one;
1684 struct stream_filter *two;
1685 char buf[FILTER_BUFFER];
1686 int end, ptr;
1687 };
1688
1689 static int cascade_filter_fn(struct stream_filter *filter,
1690 const char *input, size_t *isize_p,
1691 char *output, size_t *osize_p)
1692 {
1693 struct cascade_filter *cas = (struct cascade_filter *) filter;
1694 size_t filled = 0;
1695 size_t sz = *osize_p;
1696 size_t to_feed, remaining;
1697
1698 /*
1699 * input -- (one) --> buf -- (two) --> output
1700 */
1701 while (filled < sz) {
1702 remaining = sz - filled;
1703
1704 /* do we already have something to feed two with? */
1705 if (cas->ptr < cas->end) {
1706 to_feed = cas->end - cas->ptr;
1707 if (stream_filter(cas->two,
1708 cas->buf + cas->ptr, &to_feed,
1709 output + filled, &remaining))
1710 return -1;
1711 cas->ptr += (cas->end - cas->ptr) - to_feed;
1712 filled = sz - remaining;
1713 continue;
1714 }
1715
1716 /* feed one from upstream and have it emit into our buffer */
1717 to_feed = input ? *isize_p : 0;
1718 if (input && !to_feed)
1719 break;
1720 remaining = sizeof(cas->buf);
1721 if (stream_filter(cas->one,
1722 input, &to_feed,
1723 cas->buf, &remaining))
1724 return -1;
1725 cas->end = sizeof(cas->buf) - remaining;
1726 cas->ptr = 0;
1727 if (input) {
1728 size_t fed = *isize_p - to_feed;
1729 *isize_p -= fed;
1730 input += fed;
1731 }
1732
1733 /* do we know that we drained one completely? */
1734 if (input || cas->end)
1735 continue;
1736
1737 /* tell two to drain; we have nothing more to give it */
1738 to_feed = 0;
1739 remaining = sz - filled;
1740 if (stream_filter(cas->two,
1741 NULL, &to_feed,
1742 output + filled, &remaining))
1743 return -1;
1744 if (remaining == (sz - filled))
1745 break; /* completely drained two */
1746 filled = sz - remaining;
1747 }
1748 *osize_p -= filled;
1749 return 0;
1750 }
1751
1752 static void cascade_free_fn(struct stream_filter *filter)
1753 {
1754 struct cascade_filter *cas = (struct cascade_filter *)filter;
1755 free_stream_filter(cas->one);
1756 free_stream_filter(cas->two);
1757 free(filter);
1758 }
1759
1760 static struct stream_filter_vtbl cascade_vtbl = {
1761 cascade_filter_fn,
1762 cascade_free_fn,
1763 };
1764
1765 static struct stream_filter *cascade_filter(struct stream_filter *one,
1766 struct stream_filter *two)
1767 {
1768 struct cascade_filter *cascade;
1769
1770 if (!one || is_null_stream_filter(one))
1771 return two;
1772 if (!two || is_null_stream_filter(two))
1773 return one;
1774
1775 cascade = xmalloc(sizeof(*cascade));
1776 cascade->one = one;
1777 cascade->two = two;
1778 cascade->end = cascade->ptr = 0;
1779 cascade->filter.vtbl = &cascade_vtbl;
1780 return (struct stream_filter *)cascade;
1781 }
1782
1783 /*
1784 * ident filter
1785 */
1786 #define IDENT_DRAINING (-1)
1787 #define IDENT_SKIPPING (-2)
1788 struct ident_filter {
1789 struct stream_filter filter;
1790 struct strbuf left;
1791 int state;
1792 char ident[GIT_MAX_HEXSZ + 5]; /* ": x40 $" */
1793 };
1794
1795 static int is_foreign_ident(const char *str)
1796 {
1797 int i;
1798
1799 if (!skip_prefix(str, "$Id: ", &str))
1800 return 0;
1801 for (i = 0; str[i]; i++) {
1802 if (isspace(str[i]) && str[i+1] != '$')
1803 return 1;
1804 }
1805 return 0;
1806 }
1807
1808 static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
1809 {
1810 size_t to_drain = ident->left.len;
1811
1812 if (*osize_p < to_drain)
1813 to_drain = *osize_p;
1814 if (to_drain) {
1815 memcpy(*output_p, ident->left.buf, to_drain);
1816 strbuf_remove(&ident->left, 0, to_drain);
1817 *output_p += to_drain;
1818 *osize_p -= to_drain;
1819 }
1820 if (!ident->left.len)
1821 ident->state = 0;
1822 }
1823
1824 static int ident_filter_fn(struct stream_filter *filter,
1825 const char *input, size_t *isize_p,
1826 char *output, size_t *osize_p)
1827 {
1828 struct ident_filter *ident = (struct ident_filter *)filter;
1829 static const char head[] = "$Id";
1830
1831 if (!input) {
1832 /* drain upon eof */
1833 switch (ident->state) {
1834 default:
1835 strbuf_add(&ident->left, head, ident->state);
1836 /* fallthrough */
1837 case IDENT_SKIPPING:
1838 /* fallthrough */
1839 case IDENT_DRAINING:
1840 ident_drain(ident, &output, osize_p);
1841 }
1842 return 0;
1843 }
1844
1845 while (*isize_p || (ident->state == IDENT_DRAINING)) {
1846 int ch;
1847
1848 if (ident->state == IDENT_DRAINING) {
1849 ident_drain(ident, &output, osize_p);
1850 if (!*osize_p)
1851 break;
1852 continue;
1853 }
1854
1855 ch = *(input++);
1856 (*isize_p)--;
1857
1858 if (ident->state == IDENT_SKIPPING) {
1859 /*
1860 * Skipping until '$' or LF, but keeping them
1861 * in case it is a foreign ident.
1862 */
1863 strbuf_addch(&ident->left, ch);
1864 if (ch != '\n' && ch != '$')
1865 continue;
1866 if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
1867 strbuf_setlen(&ident->left, sizeof(head) - 1);
1868 strbuf_addstr(&ident->left, ident->ident);
1869 }
1870 ident->state = IDENT_DRAINING;
1871 continue;
1872 }
1873
1874 if (ident->state < sizeof(head) &&
1875 head[ident->state] == ch) {
1876 ident->state++;
1877 continue;
1878 }
1879
1880 if (ident->state)
1881 strbuf_add(&ident->left, head, ident->state);
1882 if (ident->state == sizeof(head) - 1) {
1883 if (ch != ':' && ch != '$') {
1884 strbuf_addch(&ident->left, ch);
1885 ident->state = 0;
1886 continue;
1887 }
1888
1889 if (ch == ':') {
1890 strbuf_addch(&ident->left, ch);
1891 ident->state = IDENT_SKIPPING;
1892 } else {
1893 strbuf_addstr(&ident->left, ident->ident);
1894 ident->state = IDENT_DRAINING;
1895 }
1896 continue;
1897 }
1898
1899 strbuf_addch(&ident->left, ch);
1900 ident->state = IDENT_DRAINING;
1901 }
1902 return 0;
1903 }
1904
1905 static void ident_free_fn(struct stream_filter *filter)
1906 {
1907 struct ident_filter *ident = (struct ident_filter *)filter;
1908 strbuf_release(&ident->left);
1909 free(filter);
1910 }
1911
1912 static struct stream_filter_vtbl ident_vtbl = {
1913 ident_filter_fn,
1914 ident_free_fn,
1915 };
1916
1917 static struct stream_filter *ident_filter(const struct object_id *oid)
1918 {
1919 struct ident_filter *ident = xmalloc(sizeof(*ident));
1920
1921 xsnprintf(ident->ident, sizeof(ident->ident),
1922 ": %s $", oid_to_hex(oid));
1923 strbuf_init(&ident->left, 0);
1924 ident->filter.vtbl = &ident_vtbl;
1925 ident->state = 0;
1926 return (struct stream_filter *)ident;
1927 }
1928
1929 /*
1930 * Return an appropriately constructed filter for the path, or NULL if
1931 * the contents cannot be filtered without reading the whole thing
1932 * in-core.
1933 *
1934 * Note that you would be crazy to set CRLF, smuge/clean or ident to a
1935 * large binary blob you would want us not to slurp into the memory!
1936 */
1937 struct stream_filter *get_stream_filter(const struct index_state *istate,
1938 const char *path,
1939 const struct object_id *oid)
1940 {
1941 struct conv_attrs ca;
1942 struct stream_filter *filter = NULL;
1943
1944 convert_attrs(istate, &ca, path);
1945 if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean))
1946 return NULL;
1947
1948 if (ca.working_tree_encoding)
1949 return NULL;
1950
1951 if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF)
1952 return NULL;
1953
1954 if (ca.ident)
1955 filter = ident_filter(oid);
1956
1957 if (output_eol(ca.crlf_action) == EOL_CRLF)
1958 filter = cascade_filter(filter, lf_to_crlf_filter());
1959 else
1960 filter = cascade_filter(filter, &null_filter_singleton);
1961
1962 return filter;
1963 }
1964
1965 void free_stream_filter(struct stream_filter *filter)
1966 {
1967 filter->vtbl->free(filter);
1968 }
1969
1970 int stream_filter(struct stream_filter *filter,
1971 const char *input, size_t *isize_p,
1972 char *output, size_t *osize_p)
1973 {
1974 return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
1975 }