clone: add --sparse mode
[git.git] / builtin / difftool.c
blobc280e682b2aec8ba8d136576d2c3039b1d62b985
1 /*
2 * "git difftool" builtin command
4 * This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
5 * git-difftool--helper script.
7 * This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
8 * The GIT_DIFF* variables are exported for use by git-difftool--helper.
10 * Any arguments that are unknown to this script are forwarded to 'git diff'.
12 * Copyright (C) 2016 Johannes Schindelin
14 #define USE_THE_INDEX_COMPATIBILITY_MACROS
15 #include "cache.h"
16 #include "config.h"
17 #include "builtin.h"
18 #include "run-command.h"
19 #include "exec-cmd.h"
20 #include "parse-options.h"
21 #include "argv-array.h"
22 #include "strbuf.h"
23 #include "lockfile.h"
24 #include "object-store.h"
25 #include "dir.h"
27 static int trust_exit_code;
29 static const char *const builtin_difftool_usage[] = {
30 N_("git difftool [<options>] [<commit> [<commit>]] [--] [<path>...]"),
31 NULL
34 static int difftool_config(const char *var, const char *value, void *cb)
36 if (!strcmp(var, "difftool.trustexitcode")) {
37 trust_exit_code = git_config_bool(var, value);
38 return 0;
41 return git_default_config(var, value, cb);
44 static int print_tool_help(void)
46 const char *argv[] = { "mergetool", "--tool-help=diff", NULL };
47 return run_command_v_opt(argv, RUN_GIT_CMD);
50 static int parse_index_info(char *p, int *mode1, int *mode2,
51 struct object_id *oid1, struct object_id *oid2,
52 char *status)
54 if (*p != ':')
55 return error("expected ':', got '%c'", *p);
56 *mode1 = (int)strtol(p + 1, &p, 8);
57 if (*p != ' ')
58 return error("expected ' ', got '%c'", *p);
59 *mode2 = (int)strtol(p + 1, &p, 8);
60 if (*p != ' ')
61 return error("expected ' ', got '%c'", *p);
62 if (parse_oid_hex(++p, oid1, (const char **)&p))
63 return error("expected object ID, got '%s'", p);
64 if (*p != ' ')
65 return error("expected ' ', got '%c'", *p);
66 if (parse_oid_hex(++p, oid2, (const char **)&p))
67 return error("expected object ID, got '%s'", p);
68 if (*p != ' ')
69 return error("expected ' ', got '%c'", *p);
70 *status = *++p;
71 if (!*status)
72 return error("missing status");
73 if (p[1] && !isdigit(p[1]))
74 return error("unexpected trailer: '%s'", p + 1);
75 return 0;
79 * Remove any trailing slash from $workdir
80 * before starting to avoid double slashes in symlink targets.
82 static void add_path(struct strbuf *buf, size_t base_len, const char *path)
84 strbuf_setlen(buf, base_len);
85 if (buf->len && buf->buf[buf->len - 1] != '/')
86 strbuf_addch(buf, '/');
87 strbuf_addstr(buf, path);
91 * Determine whether we can simply reuse the file in the worktree.
93 static int use_wt_file(const char *workdir, const char *name,
94 struct object_id *oid)
96 struct strbuf buf = STRBUF_INIT;
97 struct stat st;
98 int use = 0;
100 strbuf_addstr(&buf, workdir);
101 add_path(&buf, buf.len, name);
103 if (!lstat(buf.buf, &st) && !S_ISLNK(st.st_mode)) {
104 struct object_id wt_oid;
105 int fd = open(buf.buf, O_RDONLY);
107 if (fd >= 0 &&
108 !index_fd(&the_index, &wt_oid, fd, &st, OBJ_BLOB, name, 0)) {
109 if (is_null_oid(oid)) {
110 oidcpy(oid, &wt_oid);
111 use = 1;
112 } else if (oideq(oid, &wt_oid))
113 use = 1;
117 strbuf_release(&buf);
119 return use;
122 struct working_tree_entry {
123 struct hashmap_entry entry;
124 char path[FLEX_ARRAY];
127 static int working_tree_entry_cmp(const void *unused_cmp_data,
128 const struct hashmap_entry *eptr,
129 const struct hashmap_entry *entry_or_key,
130 const void *unused_keydata)
132 const struct working_tree_entry *a, *b;
134 a = container_of(eptr, const struct working_tree_entry, entry);
135 b = container_of(entry_or_key, const struct working_tree_entry, entry);
137 return strcmp(a->path, b->path);
141 * The `left` and `right` entries hold paths for the symlinks hashmap,
142 * and a SHA-1 surrounded by brief text for submodules.
144 struct pair_entry {
145 struct hashmap_entry entry;
146 char left[PATH_MAX], right[PATH_MAX];
147 const char path[FLEX_ARRAY];
150 static int pair_cmp(const void *unused_cmp_data,
151 const struct hashmap_entry *eptr,
152 const struct hashmap_entry *entry_or_key,
153 const void *unused_keydata)
155 const struct pair_entry *a, *b;
157 a = container_of(eptr, const struct pair_entry, entry);
158 b = container_of(entry_or_key, const struct pair_entry, entry);
160 return strcmp(a->path, b->path);
163 static void add_left_or_right(struct hashmap *map, const char *path,
164 const char *content, int is_right)
166 struct pair_entry *e, *existing;
168 FLEX_ALLOC_STR(e, path, path);
169 hashmap_entry_init(&e->entry, strhash(path));
170 existing = hashmap_get_entry(map, e, entry, NULL);
171 if (existing) {
172 free(e);
173 e = existing;
174 } else {
175 e->left[0] = e->right[0] = '\0';
176 hashmap_add(map, &e->entry);
178 strlcpy(is_right ? e->right : e->left, content, PATH_MAX);
181 struct path_entry {
182 struct hashmap_entry entry;
183 char path[FLEX_ARRAY];
186 static int path_entry_cmp(const void *unused_cmp_data,
187 const struct hashmap_entry *eptr,
188 const struct hashmap_entry *entry_or_key,
189 const void *key)
191 const struct path_entry *a, *b;
193 a = container_of(eptr, const struct path_entry, entry);
194 b = container_of(entry_or_key, const struct path_entry, entry);
196 return strcmp(a->path, key ? key : b->path);
199 static void changed_files(struct hashmap *result, const char *index_path,
200 const char *workdir)
202 struct child_process update_index = CHILD_PROCESS_INIT;
203 struct child_process diff_files = CHILD_PROCESS_INIT;
204 struct strbuf index_env = STRBUF_INIT, buf = STRBUF_INIT;
205 const char *git_dir = absolute_path(get_git_dir()), *env[] = {
206 NULL, NULL
208 FILE *fp;
210 strbuf_addf(&index_env, "GIT_INDEX_FILE=%s", index_path);
211 env[0] = index_env.buf;
213 argv_array_pushl(&update_index.args,
214 "--git-dir", git_dir, "--work-tree", workdir,
215 "update-index", "--really-refresh", "-q",
216 "--unmerged", NULL);
217 update_index.no_stdin = 1;
218 update_index.no_stdout = 1;
219 update_index.no_stderr = 1;
220 update_index.git_cmd = 1;
221 update_index.use_shell = 0;
222 update_index.clean_on_exit = 1;
223 update_index.dir = workdir;
224 update_index.env = env;
225 /* Ignore any errors of update-index */
226 run_command(&update_index);
228 argv_array_pushl(&diff_files.args,
229 "--git-dir", git_dir, "--work-tree", workdir,
230 "diff-files", "--name-only", "-z", NULL);
231 diff_files.no_stdin = 1;
232 diff_files.git_cmd = 1;
233 diff_files.use_shell = 0;
234 diff_files.clean_on_exit = 1;
235 diff_files.out = -1;
236 diff_files.dir = workdir;
237 diff_files.env = env;
238 if (start_command(&diff_files))
239 die("could not obtain raw diff");
240 fp = xfdopen(diff_files.out, "r");
241 while (!strbuf_getline_nul(&buf, fp)) {
242 struct path_entry *entry;
243 FLEX_ALLOC_STR(entry, path, buf.buf);
244 hashmap_entry_init(&entry->entry, strhash(buf.buf));
245 hashmap_add(result, &entry->entry);
247 fclose(fp);
248 if (finish_command(&diff_files))
249 die("diff-files did not exit properly");
250 strbuf_release(&index_env);
251 strbuf_release(&buf);
254 static NORETURN void exit_cleanup(const char *tmpdir, int exit_code)
256 struct strbuf buf = STRBUF_INIT;
257 strbuf_addstr(&buf, tmpdir);
258 remove_dir_recursively(&buf, 0);
259 if (exit_code)
260 warning(_("failed: %d"), exit_code);
261 exit(exit_code);
264 static int ensure_leading_directories(char *path)
266 switch (safe_create_leading_directories(path)) {
267 case SCLD_OK:
268 case SCLD_EXISTS:
269 return 0;
270 default:
271 return error(_("could not create leading directories "
272 "of '%s'"), path);
277 * Unconditional writing of a plain regular file is what
278 * "git difftool --dir-diff" wants to do for symlinks. We are preparing two
279 * temporary directories to be fed to a Git-unaware tool that knows how to
280 * show a diff of two directories (e.g. "diff -r A B").
282 * Because the tool is Git-unaware, if a symbolic link appears in either of
283 * these temporary directories, it will try to dereference and show the
284 * difference of the target of the symbolic link, which is not what we want,
285 * as the goal of the dir-diff mode is to produce an output that is logically
286 * equivalent to what "git diff" produces.
288 * Most importantly, we want to get textual comparison of the result of the
289 * readlink(2). get_symlink() provides that---it returns the contents of
290 * the symlink that gets written to a regular file to force the external tool
291 * to compare the readlink(2) result as text, even on a filesystem that is
292 * capable of doing a symbolic link.
294 static char *get_symlink(const struct object_id *oid, const char *path)
296 char *data;
297 if (is_null_oid(oid)) {
298 /* The symlink is unknown to Git so read from the filesystem */
299 struct strbuf link = STRBUF_INIT;
300 if (has_symlinks) {
301 if (strbuf_readlink(&link, path, strlen(path)))
302 die(_("could not read symlink %s"), path);
303 } else if (strbuf_read_file(&link, path, 128))
304 die(_("could not read symlink file %s"), path);
306 data = strbuf_detach(&link, NULL);
307 } else {
308 enum object_type type;
309 unsigned long size;
310 data = read_object_file(oid, &type, &size);
311 if (!data)
312 die(_("could not read object %s for symlink %s"),
313 oid_to_hex(oid), path);
316 return data;
319 static int checkout_path(unsigned mode, struct object_id *oid,
320 const char *path, const struct checkout *state)
322 struct cache_entry *ce;
323 int ret;
325 ce = make_transient_cache_entry(mode, oid, path, 0);
326 ret = checkout_entry(ce, state, NULL, NULL);
328 discard_cache_entry(ce);
329 return ret;
332 static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
333 int argc, const char **argv)
335 char tmpdir[PATH_MAX];
336 struct strbuf info = STRBUF_INIT, lpath = STRBUF_INIT;
337 struct strbuf rpath = STRBUF_INIT, buf = STRBUF_INIT;
338 struct strbuf ldir = STRBUF_INIT, rdir = STRBUF_INIT;
339 struct strbuf wtdir = STRBUF_INIT;
340 char *lbase_dir, *rbase_dir;
341 size_t ldir_len, rdir_len, wtdir_len;
342 const char *workdir, *tmp;
343 int ret = 0, i;
344 FILE *fp;
345 struct hashmap working_tree_dups, submodules, symlinks2;
346 struct hashmap_iter iter;
347 struct pair_entry *entry;
348 struct index_state wtindex;
349 struct checkout lstate, rstate;
350 int rc, flags = RUN_GIT_CMD, err = 0;
351 struct child_process child = CHILD_PROCESS_INIT;
352 const char *helper_argv[] = { "difftool--helper", NULL, NULL, NULL };
353 struct hashmap wt_modified, tmp_modified;
354 int indices_loaded = 0;
356 workdir = get_git_work_tree();
358 /* Setup temp directories */
359 tmp = getenv("TMPDIR");
360 xsnprintf(tmpdir, sizeof(tmpdir), "%s/git-difftool.XXXXXX", tmp ? tmp : "/tmp");
361 if (!mkdtemp(tmpdir))
362 return error("could not create '%s'", tmpdir);
363 strbuf_addf(&ldir, "%s/left/", tmpdir);
364 strbuf_addf(&rdir, "%s/right/", tmpdir);
365 strbuf_addstr(&wtdir, workdir);
366 if (!wtdir.len || !is_dir_sep(wtdir.buf[wtdir.len - 1]))
367 strbuf_addch(&wtdir, '/');
368 mkdir(ldir.buf, 0700);
369 mkdir(rdir.buf, 0700);
371 memset(&wtindex, 0, sizeof(wtindex));
373 memset(&lstate, 0, sizeof(lstate));
374 lstate.base_dir = lbase_dir = xstrdup(ldir.buf);
375 lstate.base_dir_len = ldir.len;
376 lstate.force = 1;
377 memset(&rstate, 0, sizeof(rstate));
378 rstate.base_dir = rbase_dir = xstrdup(rdir.buf);
379 rstate.base_dir_len = rdir.len;
380 rstate.force = 1;
382 ldir_len = ldir.len;
383 rdir_len = rdir.len;
384 wtdir_len = wtdir.len;
386 hashmap_init(&working_tree_dups, working_tree_entry_cmp, NULL, 0);
387 hashmap_init(&submodules, pair_cmp, NULL, 0);
388 hashmap_init(&symlinks2, pair_cmp, NULL, 0);
390 child.no_stdin = 1;
391 child.git_cmd = 1;
392 child.use_shell = 0;
393 child.clean_on_exit = 1;
394 child.dir = prefix;
395 child.out = -1;
396 argv_array_pushl(&child.args, "diff", "--raw", "--no-abbrev", "-z",
397 NULL);
398 for (i = 0; i < argc; i++)
399 argv_array_push(&child.args, argv[i]);
400 if (start_command(&child))
401 die("could not obtain raw diff");
402 fp = xfdopen(child.out, "r");
404 /* Build index info for left and right sides of the diff */
405 i = 0;
406 while (!strbuf_getline_nul(&info, fp)) {
407 int lmode, rmode;
408 struct object_id loid, roid;
409 char status;
410 const char *src_path, *dst_path;
412 if (starts_with(info.buf, "::"))
413 die(N_("combined diff formats('-c' and '--cc') are "
414 "not supported in\n"
415 "directory diff mode('-d' and '--dir-diff')."));
417 if (parse_index_info(info.buf, &lmode, &rmode, &loid, &roid,
418 &status))
419 break;
420 if (strbuf_getline_nul(&lpath, fp))
421 break;
422 src_path = lpath.buf;
424 i++;
425 if (status != 'C' && status != 'R') {
426 dst_path = src_path;
427 } else {
428 if (strbuf_getline_nul(&rpath, fp))
429 break;
430 dst_path = rpath.buf;
433 if (S_ISGITLINK(lmode) || S_ISGITLINK(rmode)) {
434 strbuf_reset(&buf);
435 strbuf_addf(&buf, "Subproject commit %s",
436 oid_to_hex(&loid));
437 add_left_or_right(&submodules, src_path, buf.buf, 0);
438 strbuf_reset(&buf);
439 strbuf_addf(&buf, "Subproject commit %s",
440 oid_to_hex(&roid));
441 if (oideq(&loid, &roid))
442 strbuf_addstr(&buf, "-dirty");
443 add_left_or_right(&submodules, dst_path, buf.buf, 1);
444 continue;
447 if (S_ISLNK(lmode)) {
448 char *content = get_symlink(&loid, src_path);
449 add_left_or_right(&symlinks2, src_path, content, 0);
450 free(content);
453 if (S_ISLNK(rmode)) {
454 char *content = get_symlink(&roid, dst_path);
455 add_left_or_right(&symlinks2, dst_path, content, 1);
456 free(content);
459 if (lmode && status != 'C') {
460 if (checkout_path(lmode, &loid, src_path, &lstate)) {
461 ret = error("could not write '%s'", src_path);
462 goto finish;
466 if (rmode && !S_ISLNK(rmode)) {
467 struct working_tree_entry *entry;
469 /* Avoid duplicate working_tree entries */
470 FLEX_ALLOC_STR(entry, path, dst_path);
471 hashmap_entry_init(&entry->entry, strhash(dst_path));
472 if (hashmap_get(&working_tree_dups, &entry->entry,
473 NULL)) {
474 free(entry);
475 continue;
477 hashmap_add(&working_tree_dups, &entry->entry);
479 if (!use_wt_file(workdir, dst_path, &roid)) {
480 if (checkout_path(rmode, &roid, dst_path,
481 &rstate)) {
482 ret = error("could not write '%s'",
483 dst_path);
484 goto finish;
486 } else if (!is_null_oid(&roid)) {
488 * Changes in the working tree need special
489 * treatment since they are not part of the
490 * index.
492 struct cache_entry *ce2 =
493 make_cache_entry(&wtindex, rmode, &roid,
494 dst_path, 0, 0);
496 add_index_entry(&wtindex, ce2,
497 ADD_CACHE_JUST_APPEND);
499 add_path(&rdir, rdir_len, dst_path);
500 if (ensure_leading_directories(rdir.buf)) {
501 ret = error("could not create "
502 "directory for '%s'",
503 dst_path);
504 goto finish;
506 add_path(&wtdir, wtdir_len, dst_path);
507 if (symlinks) {
508 if (symlink(wtdir.buf, rdir.buf)) {
509 ret = error_errno("could not symlink '%s' to '%s'", wtdir.buf, rdir.buf);
510 goto finish;
512 } else {
513 struct stat st;
514 if (stat(wtdir.buf, &st))
515 st.st_mode = 0644;
516 if (copy_file(rdir.buf, wtdir.buf,
517 st.st_mode)) {
518 ret = error("could not copy '%s' to '%s'", wtdir.buf, rdir.buf);
519 goto finish;
526 fclose(fp);
527 fp = NULL;
528 if (finish_command(&child)) {
529 ret = error("error occurred running diff --raw");
530 goto finish;
533 if (!i)
534 goto finish;
537 * Changes to submodules require special treatment.This loop writes a
538 * temporary file to both the left and right directories to show the
539 * change in the recorded SHA1 for the submodule.
541 hashmap_for_each_entry(&submodules, &iter, entry,
542 entry /* member name */) {
543 if (*entry->left) {
544 add_path(&ldir, ldir_len, entry->path);
545 ensure_leading_directories(ldir.buf);
546 write_file(ldir.buf, "%s", entry->left);
548 if (*entry->right) {
549 add_path(&rdir, rdir_len, entry->path);
550 ensure_leading_directories(rdir.buf);
551 write_file(rdir.buf, "%s", entry->right);
556 * Symbolic links require special treatment.The standard "git diff"
557 * shows only the link itself, not the contents of the link target.
558 * This loop replicates that behavior.
560 hashmap_for_each_entry(&symlinks2, &iter, entry,
561 entry /* member name */) {
562 if (*entry->left) {
563 add_path(&ldir, ldir_len, entry->path);
564 ensure_leading_directories(ldir.buf);
565 write_file(ldir.buf, "%s", entry->left);
567 if (*entry->right) {
568 add_path(&rdir, rdir_len, entry->path);
569 ensure_leading_directories(rdir.buf);
570 write_file(rdir.buf, "%s", entry->right);
574 strbuf_release(&buf);
576 strbuf_setlen(&ldir, ldir_len);
577 helper_argv[1] = ldir.buf;
578 strbuf_setlen(&rdir, rdir_len);
579 helper_argv[2] = rdir.buf;
581 if (extcmd) {
582 helper_argv[0] = extcmd;
583 flags = 0;
584 } else
585 setenv("GIT_DIFFTOOL_DIRDIFF", "true", 1);
586 rc = run_command_v_opt(helper_argv, flags);
589 * If the diff includes working copy files and those
590 * files were modified during the diff, then the changes
591 * should be copied back to the working tree.
592 * Do not copy back files when symlinks are used and the
593 * external tool did not replace the original link with a file.
595 * These hashes are loaded lazily since they aren't needed
596 * in the common case of --symlinks and the difftool updating
597 * files through the symlink.
599 hashmap_init(&wt_modified, path_entry_cmp, NULL, wtindex.cache_nr);
600 hashmap_init(&tmp_modified, path_entry_cmp, NULL, wtindex.cache_nr);
602 for (i = 0; i < wtindex.cache_nr; i++) {
603 struct hashmap_entry dummy;
604 const char *name = wtindex.cache[i]->name;
605 struct stat st;
607 add_path(&rdir, rdir_len, name);
608 if (lstat(rdir.buf, &st))
609 continue;
611 if ((symlinks && S_ISLNK(st.st_mode)) || !S_ISREG(st.st_mode))
612 continue;
614 if (!indices_loaded) {
615 struct lock_file lock = LOCK_INIT;
616 strbuf_reset(&buf);
617 strbuf_addf(&buf, "%s/wtindex", tmpdir);
618 if (hold_lock_file_for_update(&lock, buf.buf, 0) < 0 ||
619 write_locked_index(&wtindex, &lock, COMMIT_LOCK)) {
620 ret = error("could not write %s", buf.buf);
621 goto finish;
623 changed_files(&wt_modified, buf.buf, workdir);
624 strbuf_setlen(&rdir, rdir_len);
625 changed_files(&tmp_modified, buf.buf, rdir.buf);
626 add_path(&rdir, rdir_len, name);
627 indices_loaded = 1;
630 hashmap_entry_init(&dummy, strhash(name));
631 if (hashmap_get(&tmp_modified, &dummy, name)) {
632 add_path(&wtdir, wtdir_len, name);
633 if (hashmap_get(&wt_modified, &dummy, name)) {
634 warning(_("both files modified: '%s' and '%s'."),
635 wtdir.buf, rdir.buf);
636 warning(_("working tree file has been left."));
637 warning("%s", "");
638 err = 1;
639 } else if (unlink(wtdir.buf) ||
640 copy_file(wtdir.buf, rdir.buf, st.st_mode))
641 warning_errno(_("could not copy '%s' to '%s'"),
642 rdir.buf, wtdir.buf);
646 if (err) {
647 warning(_("temporary files exist in '%s'."), tmpdir);
648 warning(_("you may want to cleanup or recover these."));
649 exit(1);
650 } else
651 exit_cleanup(tmpdir, rc);
653 finish:
654 if (fp)
655 fclose(fp);
657 free(lbase_dir);
658 free(rbase_dir);
659 strbuf_release(&ldir);
660 strbuf_release(&rdir);
661 strbuf_release(&wtdir);
662 strbuf_release(&buf);
664 return ret;
667 static int run_file_diff(int prompt, const char *prefix,
668 int argc, const char **argv)
670 struct argv_array args = ARGV_ARRAY_INIT;
671 const char *env[] = {
672 "GIT_PAGER=", "GIT_EXTERNAL_DIFF=git-difftool--helper", NULL,
673 NULL
675 int ret = 0, i;
677 if (prompt > 0)
678 env[2] = "GIT_DIFFTOOL_PROMPT=true";
679 else if (!prompt)
680 env[2] = "GIT_DIFFTOOL_NO_PROMPT=true";
683 argv_array_push(&args, "diff");
684 for (i = 0; i < argc; i++)
685 argv_array_push(&args, argv[i]);
686 ret = run_command_v_opt_cd_env(args.argv, RUN_GIT_CMD, prefix, env);
687 exit(ret);
690 int cmd_difftool(int argc, const char **argv, const char *prefix)
692 int use_gui_tool = 0, dir_diff = 0, prompt = -1, symlinks = 0,
693 tool_help = 0, no_index = 0;
694 static char *difftool_cmd = NULL, *extcmd = NULL;
695 struct option builtin_difftool_options[] = {
696 OPT_BOOL('g', "gui", &use_gui_tool,
697 N_("use `diff.guitool` instead of `diff.tool`")),
698 OPT_BOOL('d', "dir-diff", &dir_diff,
699 N_("perform a full-directory diff")),
700 OPT_SET_INT_F('y', "no-prompt", &prompt,
701 N_("do not prompt before launching a diff tool"),
702 0, PARSE_OPT_NONEG),
703 OPT_SET_INT_F(0, "prompt", &prompt, NULL,
704 1, PARSE_OPT_NONEG | PARSE_OPT_HIDDEN),
705 OPT_BOOL(0, "symlinks", &symlinks,
706 N_("use symlinks in dir-diff mode")),
707 OPT_STRING('t', "tool", &difftool_cmd, N_("tool"),
708 N_("use the specified diff tool")),
709 OPT_BOOL(0, "tool-help", &tool_help,
710 N_("print a list of diff tools that may be used with "
711 "`--tool`")),
712 OPT_BOOL(0, "trust-exit-code", &trust_exit_code,
713 N_("make 'git-difftool' exit when an invoked diff "
714 "tool returns a non - zero exit code")),
715 OPT_STRING('x', "extcmd", &extcmd, N_("command"),
716 N_("specify a custom command for viewing diffs")),
717 OPT_ARGUMENT("no-index", &no_index, N_("passed to `diff`")),
718 OPT_END()
721 git_config(difftool_config, NULL);
722 symlinks = has_symlinks;
724 argc = parse_options(argc, argv, prefix, builtin_difftool_options,
725 builtin_difftool_usage, PARSE_OPT_KEEP_UNKNOWN |
726 PARSE_OPT_KEEP_DASHDASH);
728 if (tool_help)
729 return print_tool_help();
731 if (!no_index && !startup_info->have_repository)
732 die(_("difftool requires worktree or --no-index"));
734 if (!no_index){
735 setup_work_tree();
736 setenv(GIT_DIR_ENVIRONMENT, absolute_path(get_git_dir()), 1);
737 setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1);
738 } else if (dir_diff)
739 die(_("--dir-diff is incompatible with --no-index"));
741 if (use_gui_tool + !!difftool_cmd + !!extcmd > 1)
742 die(_("--gui, --tool and --extcmd are mutually exclusive"));
744 if (use_gui_tool)
745 setenv("GIT_MERGETOOL_GUI", "true", 1);
746 else if (difftool_cmd) {
747 if (*difftool_cmd)
748 setenv("GIT_DIFF_TOOL", difftool_cmd, 1);
749 else
750 die(_("no <tool> given for --tool=<tool>"));
753 if (extcmd) {
754 if (*extcmd)
755 setenv("GIT_DIFFTOOL_EXTCMD", extcmd, 1);
756 else
757 die(_("no <cmd> given for --extcmd=<cmd>"));
760 setenv("GIT_DIFFTOOL_TRUST_EXIT_CODE",
761 trust_exit_code ? "true" : "false", 1);
764 * In directory diff mode, 'git-difftool--helper' is called once
765 * to compare the a / b directories. In file diff mode, 'git diff'
766 * will invoke a separate instance of 'git-difftool--helper' for
767 * each file that changed.
769 if (dir_diff)
770 return run_dir_diff(extcmd, symlinks, prefix, argc, argv);
771 return run_file_diff(prompt, prefix, argc, argv);