user-manual.txt: render ASCII art correctly under Asciidoctor
[git/git.git] / convert.c
1 #include "cache.h"
2 #include "config.h"
3 #include "object-store.h"
4 #include "attr.h"
5 #include "run-command.h"
6 #include "quote.h"
7 #include "sigchain.h"
8 #include "pkt-line.h"
9 #include "sub-process.h"
10 #include "utf8.h"
11
12 /*
13 * convert.c - convert a file when checking it out and checking it in.
14 *
15 * This should use the pathname to decide on whether it wants to do some
16 * more interesting conversions (automatic gzip/unzip, general format
17 * conversions etc etc), but by default it just does automatic CRLF<->LF
18 * translation when the "text" attribute or "auto_crlf" option is set.
19 */
20
21 /* Stat bits: When BIN is set, the txt bits are unset */
22 #define CONVERT_STAT_BITS_TXT_LF 0x1
23 #define CONVERT_STAT_BITS_TXT_CRLF 0x2
24 #define CONVERT_STAT_BITS_BIN 0x4
25
26 enum crlf_action {
27 CRLF_UNDEFINED,
28 CRLF_BINARY,
29 CRLF_TEXT,
30 CRLF_TEXT_INPUT,
31 CRLF_TEXT_CRLF,
32 CRLF_AUTO,
33 CRLF_AUTO_INPUT,
34 CRLF_AUTO_CRLF
35 };
36
37 struct text_stat {
38 /* NUL, CR, LF and CRLF counts */
39 unsigned nul, lonecr, lonelf, crlf;
40
41 /* These are just approximations! */
42 unsigned printable, nonprintable;
43 };
44
45 static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
46 {
47 unsigned long i;
48
49 memset(stats, 0, sizeof(*stats));
50
51 for (i = 0; i < size; i++) {
52 unsigned char c = buf[i];
53 if (c == '\r') {
54 if (i+1 < size && buf[i+1] == '\n') {
55 stats->crlf++;
56 i++;
57 } else
58 stats->lonecr++;
59 continue;
60 }
61 if (c == '\n') {
62 stats->lonelf++;
63 continue;
64 }
65 if (c == 127)
66 /* DEL */
67 stats->nonprintable++;
68 else if (c < 32) {
69 switch (c) {
70 /* BS, HT, ESC and FF */
71 case '\b': case '\t': case '\033': case '\014':
72 stats->printable++;
73 break;
74 case 0:
75 stats->nul++;
76 /* fall through */
77 default:
78 stats->nonprintable++;
79 }
80 }
81 else
82 stats->printable++;
83 }
84
85 /* If file ends with EOF then don't count this EOF as non-printable. */
86 if (size >= 1 && buf[size-1] == '\032')
87 stats->nonprintable--;
88 }
89
90 /*
91 * The same heuristics as diff.c::mmfile_is_binary()
92 * We treat files with bare CR as binary
93 */
94 static int convert_is_binary(const struct text_stat *stats)
95 {
96 if (stats->lonecr)
97 return 1;
98 if (stats->nul)
99 return 1;
100 if ((stats->printable >> 7) < stats->nonprintable)
101 return 1;
102 return 0;
103 }
104
105 static unsigned int gather_convert_stats(const char *data, unsigned long size)
106 {
107 struct text_stat stats;
108 int ret = 0;
109 if (!data || !size)
110 return 0;
111 gather_stats(data, size, &stats);
112 if (convert_is_binary(&stats))
113 ret |= CONVERT_STAT_BITS_BIN;
114 if (stats.crlf)
115 ret |= CONVERT_STAT_BITS_TXT_CRLF;
116 if (stats.lonelf)
117 ret |= CONVERT_STAT_BITS_TXT_LF;
118
119 return ret;
120 }
121
122 static const char *gather_convert_stats_ascii(const char *data, unsigned long size)
123 {
124 unsigned int convert_stats = gather_convert_stats(data, size);
125
126 if (convert_stats & CONVERT_STAT_BITS_BIN)
127 return "-text";
128 switch (convert_stats) {
129 case CONVERT_STAT_BITS_TXT_LF:
130 return "lf";
131 case CONVERT_STAT_BITS_TXT_CRLF:
132 return "crlf";
133 case CONVERT_STAT_BITS_TXT_LF | CONVERT_STAT_BITS_TXT_CRLF:
134 return "mixed";
135 default:
136 return "none";
137 }
138 }
139
140 const char *get_cached_convert_stats_ascii(const struct index_state *istate,
141 const char *path)
142 {
143 const char *ret;
144 unsigned long sz;
145 void *data = read_blob_data_from_index(istate, path, &sz);
146 ret = gather_convert_stats_ascii(data, sz);
147 free(data);
148 return ret;
149 }
150
151 const char *get_wt_convert_stats_ascii(const char *path)
152 {
153 const char *ret = "";
154 struct strbuf sb = STRBUF_INIT;
155 if (strbuf_read_file(&sb, path, 0) >= 0)
156 ret = gather_convert_stats_ascii(sb.buf, sb.len);
157 strbuf_release(&sb);
158 return ret;
159 }
160
161 static int text_eol_is_crlf(void)
162 {
163 if (auto_crlf == AUTO_CRLF_TRUE)
164 return 1;
165 else if (auto_crlf == AUTO_CRLF_INPUT)
166 return 0;
167 if (core_eol == EOL_CRLF)
168 return 1;
169 if (core_eol == EOL_UNSET && EOL_NATIVE == EOL_CRLF)
170 return 1;
171 return 0;
172 }
173
174 static enum eol output_eol(enum crlf_action crlf_action)
175 {
176 switch (crlf_action) {
177 case CRLF_BINARY:
178 return EOL_UNSET;
179 case CRLF_TEXT_CRLF:
180 return EOL_CRLF;
181 case CRLF_TEXT_INPUT:
182 return EOL_LF;
183 case CRLF_UNDEFINED:
184 case CRLF_AUTO_CRLF:
185 return EOL_CRLF;
186 case CRLF_AUTO_INPUT:
187 return EOL_LF;
188 case CRLF_TEXT:
189 case CRLF_AUTO:
190 /* fall through */
191 return text_eol_is_crlf() ? EOL_CRLF : EOL_LF;
192 }
193 warning(_("illegal crlf_action %d"), (int)crlf_action);
194 return core_eol;
195 }
196
197 static void check_global_conv_flags_eol(const char *path, enum crlf_action crlf_action,
198 struct text_stat *old_stats, struct text_stat *new_stats,
199 int conv_flags)
200 {
201 if (old_stats->crlf && !new_stats->crlf ) {
202 /*
203 * CRLFs would not be restored by checkout
204 */
205 if (conv_flags & CONV_EOL_RNDTRP_DIE)
206 die(_("CRLF would be replaced by LF in %s"), path);
207 else if (conv_flags & CONV_EOL_RNDTRP_WARN)
208 warning(_("CRLF will be replaced by LF in %s.\n"
209 "The file will have its original line"
210 " endings in your working directory"), path);
211 } else if (old_stats->lonelf && !new_stats->lonelf ) {
212 /*
213 * CRLFs would be added by checkout
214 */
215 if (conv_flags & CONV_EOL_RNDTRP_DIE)
216 die(_("LF would be replaced by CRLF in %s"), path);
217 else if (conv_flags & CONV_EOL_RNDTRP_WARN)
218 warning(_("LF will be replaced by CRLF in %s.\n"
219 "The file will have its original line"
220 " endings in your working directory"), path);
221 }
222 }
223
224 static int has_crlf_in_index(const struct index_state *istate, const char *path)
225 {
226 unsigned long sz;
227 void *data;
228 const char *crp;
229 int has_crlf = 0;
230
231 data = read_blob_data_from_index(istate, path, &sz);
232 if (!data)
233 return 0;
234
235 crp = memchr(data, '\r', sz);
236 if (crp) {
237 unsigned int ret_stats;
238 ret_stats = gather_convert_stats(data, sz);
239 if (!(ret_stats & CONVERT_STAT_BITS_BIN) &&
240 (ret_stats & CONVERT_STAT_BITS_TXT_CRLF))
241 has_crlf = 1;
242 }
243 free(data);
244 return has_crlf;
245 }
246
247 static int will_convert_lf_to_crlf(struct text_stat *stats,
248 enum crlf_action crlf_action)
249 {
250 if (output_eol(crlf_action) != EOL_CRLF)
251 return 0;
252 /* No "naked" LF? Nothing to convert, regardless. */
253 if (!stats->lonelf)
254 return 0;
255
256 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
257 /* If we have any CR or CRLF line endings, we do not touch it */
258 /* This is the new safer autocrlf-handling */
259 if (stats->lonecr || stats->crlf)
260 return 0;
261
262 if (convert_is_binary(stats))
263 return 0;
264 }
265 return 1;
266
267 }
268
269 static int validate_encoding(const char *path, const char *enc,
270 const char *data, size_t len, int die_on_error)
271 {
272 /* We only check for UTF here as UTF?? can be an alias for UTF-?? */
273 if (istarts_with(enc, "UTF")) {
274 /*
275 * Check for detectable errors in UTF encodings
276 */
277 if (has_prohibited_utf_bom(enc, data, len)) {
278 const char *error_msg = _(
279 "BOM is prohibited in '%s' if encoded as %s");
280 /*
281 * This advice is shown for UTF-??BE and UTF-??LE encodings.
282 * We cut off the last two characters of the encoding name
283 * to generate the encoding name suitable for BOMs.
284 */
285 const char *advise_msg = _(
286 "The file '%s' contains a byte order "
287 "mark (BOM). Please use UTF-%s as "
288 "working-tree-encoding.");
289 const char *stripped = NULL;
290 char *upper = xstrdup_toupper(enc);
291 upper[strlen(upper)-2] = '\0';
292 if (!skip_prefix(upper, "UTF-", &stripped))
293 skip_prefix(stripped, "UTF", &stripped);
294 advise(advise_msg, path, stripped);
295 free(upper);
296 if (die_on_error)
297 die(error_msg, path, enc);
298 else {
299 return error(error_msg, path, enc);
300 }
301
302 } else if (is_missing_required_utf_bom(enc, data, len)) {
303 const char *error_msg = _(
304 "BOM is required in '%s' if encoded as %s");
305 const char *advise_msg = _(
306 "The file '%s' is missing a byte order "
307 "mark (BOM). Please use UTF-%sBE or UTF-%sLE "
308 "(depending on the byte order) as "
309 "working-tree-encoding.");
310 const char *stripped = NULL;
311 char *upper = xstrdup_toupper(enc);
312 if (!skip_prefix(upper, "UTF-", &stripped))
313 skip_prefix(stripped, "UTF", &stripped);
314 advise(advise_msg, path, stripped, stripped);
315 free(upper);
316 if (die_on_error)
317 die(error_msg, path, enc);
318 else {
319 return error(error_msg, path, enc);
320 }
321 }
322
323 }
324 return 0;
325 }
326
327 static void trace_encoding(const char *context, const char *path,
328 const char *encoding, const char *buf, size_t len)
329 {
330 static struct trace_key coe = TRACE_KEY_INIT(WORKING_TREE_ENCODING);
331 struct strbuf trace = STRBUF_INIT;
332 int i;
333
334 strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding);
335 for (i = 0; i < len && buf; ++i) {
336 strbuf_addf(
337 &trace, "| \033[2m%2i:\033[0m %2x \033[2m%c\033[0m%c",
338 i,
339 (unsigned char) buf[i],
340 (buf[i] > 32 && buf[i] < 127 ? buf[i] : ' '),
341 ((i+1) % 8 && (i+1) < len ? ' ' : '\n')
342 );
343 }
344 strbuf_addchars(&trace, '\n', 1);
345
346 trace_strbuf(&coe, &trace);
347 strbuf_release(&trace);
348 }
349
350 static int check_roundtrip(const char *enc_name)
351 {
352 /*
353 * check_roundtrip_encoding contains a string of comma and/or
354 * space separated encodings (eg. "UTF-16, ASCII, CP1125").
355 * Search for the given encoding in that string.
356 */
357 const char *found = strcasestr(check_roundtrip_encoding, enc_name);
358 const char *next;
359 int len;
360 if (!found)
361 return 0;
362 next = found + strlen(enc_name);
363 len = strlen(check_roundtrip_encoding);
364 return (found && (
365 /*
366 * check that the found encoding is at the
367 * beginning of check_roundtrip_encoding or
368 * that it is prefixed with a space or comma
369 */
370 found == check_roundtrip_encoding || (
371 (isspace(found[-1]) || found[-1] == ',')
372 )
373 ) && (
374 /*
375 * check that the found encoding is at the
376 * end of check_roundtrip_encoding or
377 * that it is suffixed with a space or comma
378 */
379 next == check_roundtrip_encoding + len || (
380 next < check_roundtrip_encoding + len &&
381 (isspace(next[0]) || next[0] == ',')
382 )
383 ));
384 }
385
386 static const char *default_encoding = "UTF-8";
387
388 static int encode_to_git(const char *path, const char *src, size_t src_len,
389 struct strbuf *buf, const char *enc, int conv_flags)
390 {
391 char *dst;
392 size_t dst_len;
393 int die_on_error = conv_flags & CONV_WRITE_OBJECT;
394
395 /*
396 * No encoding is specified or there is nothing to encode.
397 * Tell the caller that the content was not modified.
398 */
399 if (!enc || (src && !src_len))
400 return 0;
401
402 /*
403 * Looks like we got called from "would_convert_to_git()".
404 * This means Git wants to know if it would encode (= modify!)
405 * the content. Let's answer with "yes", since an encoding was
406 * specified.
407 */
408 if (!buf && !src)
409 return 1;
410
411 if (validate_encoding(path, enc, src, src_len, die_on_error))
412 return 0;
413
414 trace_encoding("source", path, enc, src, src_len);
415 dst = reencode_string_len(src, src_len, default_encoding, enc,
416 &dst_len);
417 if (!dst) {
418 /*
419 * We could add the blob "as-is" to Git. However, on checkout
420 * we would try to reencode to the original encoding. This
421 * would fail and we would leave the user with a messed-up
422 * working tree. Let's try to avoid this by screaming loud.
423 */
424 const char* msg = _("failed to encode '%s' from %s to %s");
425 if (die_on_error)
426 die(msg, path, enc, default_encoding);
427 else {
428 error(msg, path, enc, default_encoding);
429 return 0;
430 }
431 }
432 trace_encoding("destination", path, default_encoding, dst, dst_len);
433
434 /*
435 * UTF supports lossless conversion round tripping [1] and conversions
436 * between UTF and other encodings are mostly round trip safe as
437 * Unicode aims to be a superset of all other character encodings.
438 * However, certain encodings (e.g. SHIFT-JIS) are known to have round
439 * trip issues [2]. Check the round trip conversion for all encodings
440 * listed in core.checkRoundtripEncoding.
441 *
442 * The round trip check is only performed if content is written to Git.
443 * This ensures that no information is lost during conversion to/from
444 * the internal UTF-8 representation.
445 *
446 * Please note, the code below is not tested because I was not able to
447 * generate a faulty round trip without an iconv error. Iconv errors
448 * are already caught above.
449 *
450 * [1] http://unicode.org/faq/utf_bom.html#gen2
451 * [2] https://support.microsoft.com/en-us/help/170559/prb-conversion-problem-between-shift-jis-and-unicode
452 */
453 if (die_on_error && check_roundtrip(enc)) {
454 char *re_src;
455 size_t re_src_len;
456
457 re_src = reencode_string_len(dst, dst_len,
458 enc, default_encoding,
459 &re_src_len);
460
461 trace_printf("Checking roundtrip encoding for %s...\n", enc);
462 trace_encoding("reencoded source", path, enc,
463 re_src, re_src_len);
464
465 if (!re_src || src_len != re_src_len ||
466 memcmp(src, re_src, src_len)) {
467 const char* msg = _("encoding '%s' from %s to %s and "
468 "back is not the same");
469 die(msg, path, enc, default_encoding);
470 }
471
472 free(re_src);
473 }
474
475 strbuf_attach(buf, dst, dst_len, dst_len + 1);
476 return 1;
477 }
478
479 static int encode_to_worktree(const char *path, const char *src, size_t src_len,
480 struct strbuf *buf, const char *enc)
481 {
482 char *dst;
483 size_t dst_len;
484
485 /*
486 * No encoding is specified or there is nothing to encode.
487 * Tell the caller that the content was not modified.
488 */
489 if (!enc || (src && !src_len))
490 return 0;
491
492 dst = reencode_string_len(src, src_len, enc, default_encoding,
493 &dst_len);
494 if (!dst) {
495 error(_("failed to encode '%s' from %s to %s"),
496 path, default_encoding, enc);
497 return 0;
498 }
499
500 strbuf_attach(buf, dst, dst_len, dst_len + 1);
501 return 1;
502 }
503
504 static int crlf_to_git(const struct index_state *istate,
505 const char *path, const char *src, size_t len,
506 struct strbuf *buf,
507 enum crlf_action crlf_action, int conv_flags)
508 {
509 struct text_stat stats;
510 char *dst;
511 int convert_crlf_into_lf;
512
513 if (crlf_action == CRLF_BINARY ||
514 (src && !len))
515 return 0;
516
517 /*
518 * If we are doing a dry-run and have no source buffer, there is
519 * nothing to analyze; we must assume we would convert.
520 */
521 if (!buf && !src)
522 return 1;
523
524 gather_stats(src, len, &stats);
525 /* Optimization: No CRLF? Nothing to convert, regardless. */
526 convert_crlf_into_lf = !!stats.crlf;
527
528 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
529 if (convert_is_binary(&stats))
530 return 0;
531 /*
532 * If the file in the index has any CR in it, do not
533 * convert. This is the new safer autocrlf handling,
534 * unless we want to renormalize in a merge or
535 * cherry-pick.
536 */
537 if ((!(conv_flags & CONV_EOL_RENORMALIZE)) &&
538 has_crlf_in_index(istate, path))
539 convert_crlf_into_lf = 0;
540 }
541 if (((conv_flags & CONV_EOL_RNDTRP_WARN) ||
542 ((conv_flags & CONV_EOL_RNDTRP_DIE) && len))) {
543 struct text_stat new_stats;
544 memcpy(&new_stats, &stats, sizeof(new_stats));
545 /* simulate "git add" */
546 if (convert_crlf_into_lf) {
547 new_stats.lonelf += new_stats.crlf;
548 new_stats.crlf = 0;
549 }
550 /* simulate "git checkout" */
551 if (will_convert_lf_to_crlf(&new_stats, crlf_action)) {
552 new_stats.crlf += new_stats.lonelf;
553 new_stats.lonelf = 0;
554 }
555 check_global_conv_flags_eol(path, crlf_action, &stats, &new_stats, conv_flags);
556 }
557 if (!convert_crlf_into_lf)
558 return 0;
559
560 /*
561 * At this point all of our source analysis is done, and we are sure we
562 * would convert. If we are in dry-run mode, we can give an answer.
563 */
564 if (!buf)
565 return 1;
566
567 /* only grow if not in place */
568 if (strbuf_avail(buf) + buf->len < len)
569 strbuf_grow(buf, len - buf->len);
570 dst = buf->buf;
571 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
572 /*
573 * If we guessed, we already know we rejected a file with
574 * lone CR, and we can strip a CR without looking at what
575 * follow it.
576 */
577 do {
578 unsigned char c = *src++;
579 if (c != '\r')
580 *dst++ = c;
581 } while (--len);
582 } else {
583 do {
584 unsigned char c = *src++;
585 if (! (c == '\r' && (1 < len && *src == '\n')))
586 *dst++ = c;
587 } while (--len);
588 }
589 strbuf_setlen(buf, dst - buf->buf);
590 return 1;
591 }
592
593 static int crlf_to_worktree(const char *src, size_t len,
594 struct strbuf *buf, enum crlf_action crlf_action)
595 {
596 char *to_free = NULL;
597 struct text_stat stats;
598
599 if (!len || output_eol(crlf_action) != EOL_CRLF)
600 return 0;
601
602 gather_stats(src, len, &stats);
603 if (!will_convert_lf_to_crlf(&stats, crlf_action))
604 return 0;
605
606 /* are we "faking" in place editing ? */
607 if (src == buf->buf)
608 to_free = strbuf_detach(buf, NULL);
609
610 strbuf_grow(buf, len + stats.lonelf);
611 for (;;) {
612 const char *nl = memchr(src, '\n', len);
613 if (!nl)
614 break;
615 if (nl > src && nl[-1] == '\r') {
616 strbuf_add(buf, src, nl + 1 - src);
617 } else {
618 strbuf_add(buf, src, nl - src);
619 strbuf_addstr(buf, "\r\n");
620 }
621 len -= nl + 1 - src;
622 src = nl + 1;
623 }
624 strbuf_add(buf, src, len);
625
626 free(to_free);
627 return 1;
628 }
629
630 struct filter_params {
631 const char *src;
632 unsigned long size;
633 int fd;
634 const char *cmd;
635 const char *path;
636 };
637
638 static int filter_buffer_or_fd(int in, int out, void *data)
639 {
640 /*
641 * Spawn cmd and feed the buffer contents through its stdin.
642 */
643 struct child_process child_process = CHILD_PROCESS_INIT;
644 struct filter_params *params = (struct filter_params *)data;
645 int write_err, status;
646 const char *argv[] = { NULL, NULL };
647
648 /* apply % substitution to cmd */
649 struct strbuf cmd = STRBUF_INIT;
650 struct strbuf path = STRBUF_INIT;
651 struct strbuf_expand_dict_entry dict[] = {
652 { "f", NULL, },
653 { NULL, NULL, },
654 };
655
656 /* quote the path to preserve spaces, etc. */
657 sq_quote_buf(&path, params->path);
658 dict[0].value = path.buf;
659
660 /* expand all %f with the quoted path */
661 strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
662 strbuf_release(&path);
663
664 argv[0] = cmd.buf;
665
666 child_process.argv = argv;
667 child_process.use_shell = 1;
668 child_process.in = -1;
669 child_process.out = out;
670
671 if (start_command(&child_process)) {
672 strbuf_release(&cmd);
673 return error(_("cannot fork to run external filter '%s'"),
674 params->cmd);
675 }
676
677 sigchain_push(SIGPIPE, SIG_IGN);
678
679 if (params->src) {
680 write_err = (write_in_full(child_process.in,
681 params->src, params->size) < 0);
682 if (errno == EPIPE)
683 write_err = 0;
684 } else {
685 write_err = copy_fd(params->fd, child_process.in);
686 if (write_err == COPY_WRITE_ERROR && errno == EPIPE)
687 write_err = 0;
688 }
689
690 if (close(child_process.in))
691 write_err = 1;
692 if (write_err)
693 error(_("cannot feed the input to external filter '%s'"),
694 params->cmd);
695
696 sigchain_pop(SIGPIPE);
697
698 status = finish_command(&child_process);
699 if (status)
700 error(_("external filter '%s' failed %d"), params->cmd, status);
701
702 strbuf_release(&cmd);
703 return (write_err || status);
704 }
705
706 static int apply_single_file_filter(const char *path, const char *src, size_t len, int fd,
707 struct strbuf *dst, const char *cmd)
708 {
709 /*
710 * Create a pipeline to have the command filter the buffer's
711 * contents.
712 *
713 * (child --> cmd) --> us
714 */
715 int err = 0;
716 struct strbuf nbuf = STRBUF_INIT;
717 struct async async;
718 struct filter_params params;
719
720 memset(&async, 0, sizeof(async));
721 async.proc = filter_buffer_or_fd;
722 async.data = &params;
723 async.out = -1;
724 params.src = src;
725 params.size = len;
726 params.fd = fd;
727 params.cmd = cmd;
728 params.path = path;
729
730 fflush(NULL);
731 if (start_async(&async))
732 return 0; /* error was already reported */
733
734 if (strbuf_read(&nbuf, async.out, 0) < 0) {
735 err = error(_("read from external filter '%s' failed"), cmd);
736 }
737 if (close(async.out)) {
738 err = error(_("read from external filter '%s' failed"), cmd);
739 }
740 if (finish_async(&async)) {
741 err = error(_("external filter '%s' failed"), cmd);
742 }
743
744 if (!err) {
745 strbuf_swap(dst, &nbuf);
746 }
747 strbuf_release(&nbuf);
748 return !err;
749 }
750
751 #define CAP_CLEAN (1u<<0)
752 #define CAP_SMUDGE (1u<<1)
753 #define CAP_DELAY (1u<<2)
754
755 struct cmd2process {
756 struct subprocess_entry subprocess; /* must be the first member! */
757 unsigned int supported_capabilities;
758 };
759
760 static int subprocess_map_initialized;
761 static struct hashmap subprocess_map;
762
763 static int start_multi_file_filter_fn(struct subprocess_entry *subprocess)
764 {
765 static int versions[] = {2, 0};
766 static struct subprocess_capability capabilities[] = {
767 { "clean", CAP_CLEAN },
768 { "smudge", CAP_SMUDGE },
769 { "delay", CAP_DELAY },
770 { NULL, 0 }
771 };
772 struct cmd2process *entry = (struct cmd2process *)subprocess;
773 return subprocess_handshake(subprocess, "git-filter", versions, NULL,
774 capabilities,
775 &entry->supported_capabilities);
776 }
777
778 static void handle_filter_error(const struct strbuf *filter_status,
779 struct cmd2process *entry,
780 const unsigned int wanted_capability)
781 {
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 *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$", 3);
1127 dst += 3;
1128 len -= dollar + 1 - src;
1129 src = dollar + 1;
1130 }
1131 }
1132 memmove(dst, src, len);
1133 strbuf_setlen(buf, dst + len - buf->buf);
1134 return 1;
1135 }
1136
1137 static int ident_to_worktree(const char *src, size_t len,
1138 struct strbuf *buf, int ident)
1139 {
1140 struct object_id oid;
1141 char *to_free = NULL, *dollar, *spc;
1142 int cnt;
1143
1144 if (!ident)
1145 return 0;
1146
1147 cnt = count_ident(src, len);
1148 if (!cnt)
1149 return 0;
1150
1151 /* are we "faking" in place editing ? */
1152 if (src == buf->buf)
1153 to_free = strbuf_detach(buf, NULL);
1154 hash_object_file(src, len, "blob", &oid);
1155
1156 strbuf_grow(buf, len + cnt * (the_hash_algo->hexsz + 3));
1157 for (;;) {
1158 /* step 1: run to the next '$' */
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 struct attr_check_item *ccheck = NULL;
1301
1302 if (!check) {
1303 check = attr_check_initl("crlf", "ident", "filter",
1304 "eol", "text", "working-tree-encoding",
1305 NULL);
1306 user_convert_tail = &user_convert;
1307 git_config(read_convert_config, NULL);
1308 }
1309
1310 git_check_attr(istate, path, check);
1311 ccheck = check->items;
1312 ca->crlf_action = git_path_check_crlf(ccheck + 4);
1313 if (ca->crlf_action == CRLF_UNDEFINED)
1314 ca->crlf_action = git_path_check_crlf(ccheck + 0);
1315 ca->ident = git_path_check_ident(ccheck + 1);
1316 ca->drv = git_path_check_convert(ccheck + 2);
1317 if (ca->crlf_action != CRLF_BINARY) {
1318 enum eol eol_attr = git_path_check_eol(ccheck + 3);
1319 if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_LF)
1320 ca->crlf_action = CRLF_AUTO_INPUT;
1321 else if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_CRLF)
1322 ca->crlf_action = CRLF_AUTO_CRLF;
1323 else if (eol_attr == EOL_LF)
1324 ca->crlf_action = CRLF_TEXT_INPUT;
1325 else if (eol_attr == EOL_CRLF)
1326 ca->crlf_action = CRLF_TEXT_CRLF;
1327 }
1328 ca->working_tree_encoding = git_path_check_encoding(ccheck + 5);
1329
1330 /* Save attr and make a decision for action */
1331 ca->attr_action = ca->crlf_action;
1332 if (ca->crlf_action == CRLF_TEXT)
1333 ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT;
1334 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE)
1335 ca->crlf_action = CRLF_BINARY;
1336 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_TRUE)
1337 ca->crlf_action = CRLF_AUTO_CRLF;
1338 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_INPUT)
1339 ca->crlf_action = CRLF_AUTO_INPUT;
1340 }
1341
1342 int would_convert_to_git_filter_fd(const struct index_state *istate, const char *path)
1343 {
1344 struct conv_attrs ca;
1345
1346 convert_attrs(istate, &ca, path);
1347 if (!ca.drv)
1348 return 0;
1349
1350 /*
1351 * Apply a filter to an fd only if the filter is required to succeed.
1352 * We must die if the filter fails, because the original data before
1353 * filtering is not available.
1354 */
1355 if (!ca.drv->required)
1356 return 0;
1357
1358 return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL);
1359 }
1360
1361 const char *get_convert_attr_ascii(const struct index_state *istate, const char *path)
1362 {
1363 struct conv_attrs ca;
1364
1365 convert_attrs(istate, &ca, path);
1366 switch (ca.attr_action) {
1367 case CRLF_UNDEFINED:
1368 return "";
1369 case CRLF_BINARY:
1370 return "-text";
1371 case CRLF_TEXT:
1372 return "text";
1373 case CRLF_TEXT_INPUT:
1374 return "text eol=lf";
1375 case CRLF_TEXT_CRLF:
1376 return "text eol=crlf";
1377 case CRLF_AUTO:
1378 return "text=auto";
1379 case CRLF_AUTO_CRLF:
1380 return "text=auto eol=crlf";
1381 case CRLF_AUTO_INPUT:
1382 return "text=auto eol=lf";
1383 }
1384 return "";
1385 }
1386
1387 int convert_to_git(const struct index_state *istate,
1388 const char *path, const char *src, size_t len,
1389 struct strbuf *dst, int conv_flags)
1390 {
1391 int ret = 0;
1392 struct conv_attrs ca;
1393
1394 convert_attrs(istate, &ca, path);
1395
1396 ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL);
1397 if (!ret && ca.drv && ca.drv->required)
1398 die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
1399
1400 if (ret && dst) {
1401 src = dst->buf;
1402 len = dst->len;
1403 }
1404
1405 ret |= encode_to_git(path, src, len, dst, ca.working_tree_encoding, conv_flags);
1406 if (ret && dst) {
1407 src = dst->buf;
1408 len = dst->len;
1409 }
1410
1411 if (!(conv_flags & CONV_EOL_KEEP_CRLF)) {
1412 ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, conv_flags);
1413 if (ret && dst) {
1414 src = dst->buf;
1415 len = dst->len;
1416 }
1417 }
1418 return ret | ident_to_git(src, len, dst, ca.ident);
1419 }
1420
1421 void convert_to_git_filter_fd(const struct index_state *istate,
1422 const char *path, int fd, struct strbuf *dst,
1423 int conv_flags)
1424 {
1425 struct conv_attrs ca;
1426 convert_attrs(istate, &ca, path);
1427
1428 assert(ca.drv);
1429 assert(ca.drv->clean || ca.drv->process);
1430
1431 if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL))
1432 die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
1433
1434 encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
1435 crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, conv_flags);
1436 ident_to_git(dst->buf, dst->len, dst, ca.ident);
1437 }
1438
1439 static int convert_to_working_tree_internal(const struct index_state *istate,
1440 const char *path, const char *src,
1441 size_t len, struct strbuf *dst,
1442 int normalizing, struct delayed_checkout *dco)
1443 {
1444 int ret = 0, ret_filter = 0;
1445 struct conv_attrs ca;
1446
1447 convert_attrs(istate, &ca, path);
1448
1449 ret |= ident_to_worktree(src, len, dst, ca.ident);
1450 if (ret) {
1451 src = dst->buf;
1452 len = dst->len;
1453 }
1454 /*
1455 * CRLF conversion can be skipped if normalizing, unless there
1456 * is a smudge or process filter (even if the process filter doesn't
1457 * support smudge). The filters might expect CRLFs.
1458 */
1459 if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) {
1460 ret |= crlf_to_worktree(src, len, dst, ca.crlf_action);
1461 if (ret) {
1462 src = dst->buf;
1463 len = dst->len;
1464 }
1465 }
1466
1467 ret |= encode_to_worktree(path, src, len, dst, ca.working_tree_encoding);
1468 if (ret) {
1469 src = dst->buf;
1470 len = dst->len;
1471 }
1472
1473 ret_filter = apply_filter(
1474 path, src, len, -1, dst, ca.drv, CAP_SMUDGE, dco);
1475 if (!ret_filter && ca.drv && ca.drv->required)
1476 die(_("%s: smudge filter %s failed"), path, ca.drv->name);
1477
1478 return ret | ret_filter;
1479 }
1480
1481 int async_convert_to_working_tree(const struct index_state *istate,
1482 const char *path, const char *src,
1483 size_t len, struct strbuf *dst,
1484 void *dco)
1485 {
1486 return convert_to_working_tree_internal(istate, path, src, len, dst, 0, dco);
1487 }
1488
1489 int convert_to_working_tree(const struct index_state *istate,
1490 const char *path, const char *src,
1491 size_t len, struct strbuf *dst)
1492 {
1493 return convert_to_working_tree_internal(istate, path, src, len, dst, 0, NULL);
1494 }
1495
1496 int renormalize_buffer(const struct index_state *istate, const char *path,
1497 const char *src, size_t len, struct strbuf *dst)
1498 {
1499 int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL);
1500 if (ret) {
1501 src = dst->buf;
1502 len = dst->len;
1503 }
1504 return ret | convert_to_git(istate, path, src, len, dst, CONV_EOL_RENORMALIZE);
1505 }
1506
1507 /*****************************************************************
1508 *
1509 * Streaming conversion support
1510 *
1511 *****************************************************************/
1512
1513 typedef int (*filter_fn)(struct stream_filter *,
1514 const char *input, size_t *isize_p,
1515 char *output, size_t *osize_p);
1516 typedef void (*free_fn)(struct stream_filter *);
1517
1518 struct stream_filter_vtbl {
1519 filter_fn filter;
1520 free_fn free;
1521 };
1522
1523 struct stream_filter {
1524 struct stream_filter_vtbl *vtbl;
1525 };
1526
1527 static int null_filter_fn(struct stream_filter *filter,
1528 const char *input, size_t *isize_p,
1529 char *output, size_t *osize_p)
1530 {
1531 size_t count;
1532
1533 if (!input)
1534 return 0; /* we do not keep any states */
1535 count = *isize_p;
1536 if (*osize_p < count)
1537 count = *osize_p;
1538 if (count) {
1539 memmove(output, input, count);
1540 *isize_p -= count;
1541 *osize_p -= count;
1542 }
1543 return 0;
1544 }
1545
1546 static void null_free_fn(struct stream_filter *filter)
1547 {
1548 ; /* nothing -- null instances are shared */
1549 }
1550
1551 static struct stream_filter_vtbl null_vtbl = {
1552 null_filter_fn,
1553 null_free_fn,
1554 };
1555
1556 static struct stream_filter null_filter_singleton = {
1557 &null_vtbl,
1558 };
1559
1560 int is_null_stream_filter(struct stream_filter *filter)
1561 {
1562 return filter == &null_filter_singleton;
1563 }
1564
1565
1566 /*
1567 * LF-to-CRLF filter
1568 */
1569
1570 struct lf_to_crlf_filter {
1571 struct stream_filter filter;
1572 unsigned has_held:1;
1573 char held;
1574 };
1575
1576 static int lf_to_crlf_filter_fn(struct stream_filter *filter,
1577 const char *input, size_t *isize_p,
1578 char *output, size_t *osize_p)
1579 {
1580 size_t count, o = 0;
1581 struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter;
1582
1583 /*
1584 * We may be holding onto the CR to see if it is followed by a
1585 * LF, in which case we would need to go to the main loop.
1586 * Otherwise, just emit it to the output stream.
1587 */
1588 if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) {
1589 output[o++] = lf_to_crlf->held;
1590 lf_to_crlf->has_held = 0;
1591 }
1592
1593 /* We are told to drain */
1594 if (!input) {
1595 *osize_p -= o;
1596 return 0;
1597 }
1598
1599 count = *isize_p;
1600 if (count || lf_to_crlf->has_held) {
1601 size_t i;
1602 int was_cr = 0;
1603
1604 if (lf_to_crlf->has_held) {
1605 was_cr = 1;
1606 lf_to_crlf->has_held = 0;
1607 }
1608
1609 for (i = 0; o < *osize_p && i < count; i++) {
1610 char ch = input[i];
1611
1612 if (ch == '\n') {
1613 output[o++] = '\r';
1614 } else if (was_cr) {
1615 /*
1616 * Previous round saw CR and it is not followed
1617 * by a LF; emit the CR before processing the
1618 * current character.
1619 */
1620 output[o++] = '\r';
1621 }
1622
1623 /*
1624 * We may have consumed the last output slot,
1625 * in which case we need to break out of this
1626 * loop; hold the current character before
1627 * returning.
1628 */
1629 if (*osize_p <= o) {
1630 lf_to_crlf->has_held = 1;
1631 lf_to_crlf->held = ch;
1632 continue; /* break but increment i */
1633 }
1634
1635 if (ch == '\r') {
1636 was_cr = 1;
1637 continue;
1638 }
1639
1640 was_cr = 0;
1641 output[o++] = ch;
1642 }
1643
1644 *osize_p -= o;
1645 *isize_p -= i;
1646
1647 if (!lf_to_crlf->has_held && was_cr) {
1648 lf_to_crlf->has_held = 1;
1649 lf_to_crlf->held = '\r';
1650 }
1651 }
1652 return 0;
1653 }
1654
1655 static void lf_to_crlf_free_fn(struct stream_filter *filter)
1656 {
1657 free(filter);
1658 }
1659
1660 static struct stream_filter_vtbl lf_to_crlf_vtbl = {
1661 lf_to_crlf_filter_fn,
1662 lf_to_crlf_free_fn,
1663 };
1664
1665 static struct stream_filter *lf_to_crlf_filter(void)
1666 {
1667 struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf));
1668
1669 lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl;
1670 return (struct stream_filter *)lf_to_crlf;
1671 }
1672
1673 /*
1674 * Cascade filter
1675 */
1676 #define FILTER_BUFFER 1024
1677 struct cascade_filter {
1678 struct stream_filter filter;
1679 struct stream_filter *one;
1680 struct stream_filter *two;
1681 char buf[FILTER_BUFFER];
1682 int end, ptr;
1683 };
1684
1685 static int cascade_filter_fn(struct stream_filter *filter,
1686 const char *input, size_t *isize_p,
1687 char *output, size_t *osize_p)
1688 {
1689 struct cascade_filter *cas = (struct cascade_filter *) filter;
1690 size_t filled = 0;
1691 size_t sz = *osize_p;
1692 size_t to_feed, remaining;
1693
1694 /*
1695 * input -- (one) --> buf -- (two) --> output
1696 */
1697 while (filled < sz) {
1698 remaining = sz - filled;
1699
1700 /* do we already have something to feed two with? */
1701 if (cas->ptr < cas->end) {
1702 to_feed = cas->end - cas->ptr;
1703 if (stream_filter(cas->two,
1704 cas->buf + cas->ptr, &to_feed,
1705 output + filled, &remaining))
1706 return -1;
1707 cas->ptr += (cas->end - cas->ptr) - to_feed;
1708 filled = sz - remaining;
1709 continue;
1710 }
1711
1712 /* feed one from upstream and have it emit into our buffer */
1713 to_feed = input ? *isize_p : 0;
1714 if (input && !to_feed)
1715 break;
1716 remaining = sizeof(cas->buf);
1717 if (stream_filter(cas->one,
1718 input, &to_feed,
1719 cas->buf, &remaining))
1720 return -1;
1721 cas->end = sizeof(cas->buf) - remaining;
1722 cas->ptr = 0;
1723 if (input) {
1724 size_t fed = *isize_p - to_feed;
1725 *isize_p -= fed;
1726 input += fed;
1727 }
1728
1729 /* do we know that we drained one completely? */
1730 if (input || cas->end)
1731 continue;
1732
1733 /* tell two to drain; we have nothing more to give it */
1734 to_feed = 0;
1735 remaining = sz - filled;
1736 if (stream_filter(cas->two,
1737 NULL, &to_feed,
1738 output + filled, &remaining))
1739 return -1;
1740 if (remaining == (sz - filled))
1741 break; /* completely drained two */
1742 filled = sz - remaining;
1743 }
1744 *osize_p -= filled;
1745 return 0;
1746 }
1747
1748 static void cascade_free_fn(struct stream_filter *filter)
1749 {
1750 struct cascade_filter *cas = (struct cascade_filter *)filter;
1751 free_stream_filter(cas->one);
1752 free_stream_filter(cas->two);
1753 free(filter);
1754 }
1755
1756 static struct stream_filter_vtbl cascade_vtbl = {
1757 cascade_filter_fn,
1758 cascade_free_fn,
1759 };
1760
1761 static struct stream_filter *cascade_filter(struct stream_filter *one,
1762 struct stream_filter *two)
1763 {
1764 struct cascade_filter *cascade;
1765
1766 if (!one || is_null_stream_filter(one))
1767 return two;
1768 if (!two || is_null_stream_filter(two))
1769 return one;
1770
1771 cascade = xmalloc(sizeof(*cascade));
1772 cascade->one = one;
1773 cascade->two = two;
1774 cascade->end = cascade->ptr = 0;
1775 cascade->filter.vtbl = &cascade_vtbl;
1776 return (struct stream_filter *)cascade;
1777 }
1778
1779 /*
1780 * ident filter
1781 */
1782 #define IDENT_DRAINING (-1)
1783 #define IDENT_SKIPPING (-2)
1784 struct ident_filter {
1785 struct stream_filter filter;
1786 struct strbuf left;
1787 int state;
1788 char ident[GIT_MAX_HEXSZ + 5]; /* ": x40 $" */
1789 };
1790
1791 static int is_foreign_ident(const char *str)
1792 {
1793 int i;
1794
1795 if (!skip_prefix(str, "$Id: ", &str))
1796 return 0;
1797 for (i = 0; str[i]; i++) {
1798 if (isspace(str[i]) && str[i+1] != '$')
1799 return 1;
1800 }
1801 return 0;
1802 }
1803
1804 static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
1805 {
1806 size_t to_drain = ident->left.len;
1807
1808 if (*osize_p < to_drain)
1809 to_drain = *osize_p;
1810 if (to_drain) {
1811 memcpy(*output_p, ident->left.buf, to_drain);
1812 strbuf_remove(&ident->left, 0, to_drain);
1813 *output_p += to_drain;
1814 *osize_p -= to_drain;
1815 }
1816 if (!ident->left.len)
1817 ident->state = 0;
1818 }
1819
1820 static int ident_filter_fn(struct stream_filter *filter,
1821 const char *input, size_t *isize_p,
1822 char *output, size_t *osize_p)
1823 {
1824 struct ident_filter *ident = (struct ident_filter *)filter;
1825 static const char head[] = "$Id";
1826
1827 if (!input) {
1828 /* drain upon eof */
1829 switch (ident->state) {
1830 default:
1831 strbuf_add(&ident->left, head, ident->state);
1832 /* fallthrough */
1833 case IDENT_SKIPPING:
1834 /* fallthrough */
1835 case IDENT_DRAINING:
1836 ident_drain(ident, &output, osize_p);
1837 }
1838 return 0;
1839 }
1840
1841 while (*isize_p || (ident->state == IDENT_DRAINING)) {
1842 int ch;
1843
1844 if (ident->state == IDENT_DRAINING) {
1845 ident_drain(ident, &output, osize_p);
1846 if (!*osize_p)
1847 break;
1848 continue;
1849 }
1850
1851 ch = *(input++);
1852 (*isize_p)--;
1853
1854 if (ident->state == IDENT_SKIPPING) {
1855 /*
1856 * Skipping until '$' or LF, but keeping them
1857 * in case it is a foreign ident.
1858 */
1859 strbuf_addch(&ident->left, ch);
1860 if (ch != '\n' && ch != '$')
1861 continue;
1862 if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
1863 strbuf_setlen(&ident->left, sizeof(head) - 1);
1864 strbuf_addstr(&ident->left, ident->ident);
1865 }
1866 ident->state = IDENT_DRAINING;
1867 continue;
1868 }
1869
1870 if (ident->state < sizeof(head) &&
1871 head[ident->state] == ch) {
1872 ident->state++;
1873 continue;
1874 }
1875
1876 if (ident->state)
1877 strbuf_add(&ident->left, head, ident->state);
1878 if (ident->state == sizeof(head) - 1) {
1879 if (ch != ':' && ch != '$') {
1880 strbuf_addch(&ident->left, ch);
1881 ident->state = 0;
1882 continue;
1883 }
1884
1885 if (ch == ':') {
1886 strbuf_addch(&ident->left, ch);
1887 ident->state = IDENT_SKIPPING;
1888 } else {
1889 strbuf_addstr(&ident->left, ident->ident);
1890 ident->state = IDENT_DRAINING;
1891 }
1892 continue;
1893 }
1894
1895 strbuf_addch(&ident->left, ch);
1896 ident->state = IDENT_DRAINING;
1897 }
1898 return 0;
1899 }
1900
1901 static void ident_free_fn(struct stream_filter *filter)
1902 {
1903 struct ident_filter *ident = (struct ident_filter *)filter;
1904 strbuf_release(&ident->left);
1905 free(filter);
1906 }
1907
1908 static struct stream_filter_vtbl ident_vtbl = {
1909 ident_filter_fn,
1910 ident_free_fn,
1911 };
1912
1913 static struct stream_filter *ident_filter(const struct object_id *oid)
1914 {
1915 struct ident_filter *ident = xmalloc(sizeof(*ident));
1916
1917 xsnprintf(ident->ident, sizeof(ident->ident),
1918 ": %s $", oid_to_hex(oid));
1919 strbuf_init(&ident->left, 0);
1920 ident->filter.vtbl = &ident_vtbl;
1921 ident->state = 0;
1922 return (struct stream_filter *)ident;
1923 }
1924
1925 /*
1926 * Return an appropriately constructed filter for the path, or NULL if
1927 * the contents cannot be filtered without reading the whole thing
1928 * in-core.
1929 *
1930 * Note that you would be crazy to set CRLF, smuge/clean or ident to a
1931 * large binary blob you would want us not to slurp into the memory!
1932 */
1933 struct stream_filter *get_stream_filter(const struct index_state *istate,
1934 const char *path,
1935 const struct object_id *oid)
1936 {
1937 struct conv_attrs ca;
1938 struct stream_filter *filter = NULL;
1939
1940 convert_attrs(istate, &ca, path);
1941 if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean))
1942 return NULL;
1943
1944 if (ca.working_tree_encoding)
1945 return NULL;
1946
1947 if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF)
1948 return NULL;
1949
1950 if (ca.ident)
1951 filter = ident_filter(oid);
1952
1953 if (output_eol(ca.crlf_action) == EOL_CRLF)
1954 filter = cascade_filter(filter, lf_to_crlf_filter());
1955 else
1956 filter = cascade_filter(filter, &null_filter_singleton);
1957
1958 return filter;
1959 }
1960
1961 void free_stream_filter(struct stream_filter *filter)
1962 {
1963 filter->vtbl->free(filter);
1964 }
1965
1966 int stream_filter(struct stream_filter *filter,
1967 const char *input, size_t *isize_p,
1968 char *output, size_t *osize_p)
1969 {
1970 return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
1971 }