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Commit | Line | Data |
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525ab639 JH |
1 | /* |
2 | * Low level 3-way in-core file merge. | |
3 | * | |
4 | * Copyright (c) 2007 Junio C Hamano | |
5 | */ | |
6 | ||
7 | #include "cache.h" | |
8 | #include "attr.h" | |
9 | #include "xdiff-interface.h" | |
10 | #include "run-command.h" | |
525ab639 | 11 | #include "ll-merge.h" |
ef45bb1f | 12 | #include "quote.h" |
525ab639 JH |
13 | |
14 | struct ll_merge_driver; | |
15 | ||
16 | typedef int (*ll_merge_fn)(const struct ll_merge_driver *, | |
17 | mmbuffer_t *result, | |
18 | const char *path, | |
f01de62e | 19 | mmfile_t *orig, const char *orig_name, |
525ab639 JH |
20 | mmfile_t *src1, const char *name1, |
21 | mmfile_t *src2, const char *name2, | |
712516bc | 22 | const struct ll_merge_options *opts, |
23a64c9e | 23 | int marker_size); |
525ab639 JH |
24 | |
25 | struct ll_merge_driver { | |
26 | const char *name; | |
27 | const char *description; | |
28 | ll_merge_fn fn; | |
29 | const char *recursive; | |
30 | struct ll_merge_driver *next; | |
31 | char *cmdline; | |
32 | }; | |
33 | ||
34 | /* | |
35 | * Built-in low-levels | |
36 | */ | |
37 | static int ll_binary_merge(const struct ll_merge_driver *drv_unused, | |
38 | mmbuffer_t *result, | |
e0e2065f | 39 | const char *path, |
f01de62e | 40 | mmfile_t *orig, const char *orig_name, |
525ab639 JH |
41 | mmfile_t *src1, const char *name1, |
42 | mmfile_t *src2, const char *name2, | |
712516bc JN |
43 | const struct ll_merge_options *opts, |
44 | int marker_size) | |
525ab639 | 45 | { |
712516bc JN |
46 | mmfile_t *stolen; |
47 | assert(opts); | |
48 | ||
525ab639 | 49 | /* |
ed34567c JH |
50 | * The tentative merge result is the common ancestor for an |
51 | * internal merge. For the final merge, it is "ours" by | |
52 | * default but -Xours/-Xtheirs can tweak the choice. | |
525ab639 | 53 | */ |
a944af1d JH |
54 | if (opts->virtual_ancestor) { |
55 | stolen = orig; | |
56 | } else { | |
57 | switch (opts->variant) { | |
58 | default: | |
e6d29a4b | 59 | warning("Cannot merge binary files: %s (%s vs. %s)", |
e0e2065f JH |
60 | path, name1, name2); |
61 | /* fallthru */ | |
a944af1d JH |
62 | case XDL_MERGE_FAVOR_OURS: |
63 | stolen = src1; | |
64 | break; | |
65 | case XDL_MERGE_FAVOR_THEIRS: | |
66 | stolen = src2; | |
67 | break; | |
68 | } | |
69 | } | |
525ab639 JH |
70 | |
71 | result->ptr = stolen->ptr; | |
72 | result->size = stolen->size; | |
73 | stolen->ptr = NULL; | |
a944af1d JH |
74 | |
75 | /* | |
76 | * With -Xtheirs or -Xours, we have cleanly merged; | |
77 | * otherwise we got a conflict. | |
78 | */ | |
79 | return (opts->variant ? 0 : 1); | |
525ab639 JH |
80 | } |
81 | ||
82 | static int ll_xdl_merge(const struct ll_merge_driver *drv_unused, | |
83 | mmbuffer_t *result, | |
606475f3 | 84 | const char *path, |
f01de62e | 85 | mmfile_t *orig, const char *orig_name, |
525ab639 JH |
86 | mmfile_t *src1, const char *name1, |
87 | mmfile_t *src2, const char *name2, | |
712516bc JN |
88 | const struct ll_merge_options *opts, |
89 | int marker_size) | |
525ab639 | 90 | { |
00f8f97d | 91 | xmparam_t xmp; |
712516bc | 92 | assert(opts); |
525ab639 | 93 | |
dcd1742e JK |
94 | if (orig->size > MAX_XDIFF_SIZE || |
95 | src1->size > MAX_XDIFF_SIZE || | |
96 | src2->size > MAX_XDIFF_SIZE || | |
97 | buffer_is_binary(orig->ptr, orig->size) || | |
525ab639 JH |
98 | buffer_is_binary(src1->ptr, src1->size) || |
99 | buffer_is_binary(src2->ptr, src2->size)) { | |
525ab639 | 100 | return ll_binary_merge(drv_unused, result, |
606475f3 | 101 | path, |
f01de62e JN |
102 | orig, orig_name, |
103 | src1, name1, | |
525ab639 | 104 | src2, name2, |
712516bc | 105 | opts, marker_size); |
525ab639 JH |
106 | } |
107 | ||
00f8f97d | 108 | memset(&xmp, 0, sizeof(xmp)); |
560119b9 | 109 | xmp.level = XDL_MERGE_ZEALOUS; |
712516bc | 110 | xmp.favor = opts->variant; |
58a1ece4 | 111 | xmp.xpp.flags = opts->xdl_opts; |
c236bcd0 | 112 | if (git_xmerge_style >= 0) |
560119b9 | 113 | xmp.style = git_xmerge_style; |
23a64c9e JH |
114 | if (marker_size > 0) |
115 | xmp.marker_size = marker_size; | |
f01de62e | 116 | xmp.ancestor = orig_name; |
a4b5e91c JN |
117 | xmp.file1 = name1; |
118 | xmp.file2 = name2; | |
119 | return xdl_merge(orig, src1, src2, &xmp, result); | |
525ab639 JH |
120 | } |
121 | ||
122 | static int ll_union_merge(const struct ll_merge_driver *drv_unused, | |
123 | mmbuffer_t *result, | |
124 | const char *path_unused, | |
f01de62e | 125 | mmfile_t *orig, const char *orig_name, |
525ab639 JH |
126 | mmfile_t *src1, const char *name1, |
127 | mmfile_t *src2, const char *name2, | |
712516bc JN |
128 | const struct ll_merge_options *opts, |
129 | int marker_size) | |
525ab639 | 130 | { |
cd1d61c4 | 131 | /* Use union favor */ |
712516bc JN |
132 | struct ll_merge_options o; |
133 | assert(opts); | |
134 | o = *opts; | |
135 | o.variant = XDL_MERGE_FAVOR_UNION; | |
cd1d61c4 | 136 | return ll_xdl_merge(drv_unused, result, path_unused, |
f01de62e | 137 | orig, NULL, src1, NULL, src2, NULL, |
712516bc | 138 | &o, marker_size); |
525ab639 JH |
139 | } |
140 | ||
141 | #define LL_BINARY_MERGE 0 | |
142 | #define LL_TEXT_MERGE 1 | |
143 | #define LL_UNION_MERGE 2 | |
144 | static struct ll_merge_driver ll_merge_drv[] = { | |
145 | { "binary", "built-in binary merge", ll_binary_merge }, | |
146 | { "text", "built-in 3-way text merge", ll_xdl_merge }, | |
147 | { "union", "built-in union merge", ll_union_merge }, | |
148 | }; | |
149 | ||
5096d490 | 150 | static void create_temp(mmfile_t *src, char *path, size_t len) |
525ab639 JH |
151 | { |
152 | int fd; | |
153 | ||
5096d490 | 154 | xsnprintf(path, len, ".merge_file_XXXXXX"); |
525ab639 JH |
155 | fd = xmkstemp(path); |
156 | if (write_in_full(fd, src->ptr, src->size) != src->size) | |
0721c314 | 157 | die_errno("unable to write temp-file"); |
525ab639 JH |
158 | close(fd); |
159 | } | |
160 | ||
161 | /* | |
162 | * User defined low-level merge driver support. | |
163 | */ | |
164 | static int ll_ext_merge(const struct ll_merge_driver *fn, | |
165 | mmbuffer_t *result, | |
166 | const char *path, | |
f01de62e | 167 | mmfile_t *orig, const char *orig_name, |
525ab639 JH |
168 | mmfile_t *src1, const char *name1, |
169 | mmfile_t *src2, const char *name2, | |
712516bc JN |
170 | const struct ll_merge_options *opts, |
171 | int marker_size) | |
525ab639 | 172 | { |
23a64c9e | 173 | char temp[4][50]; |
ced621b2 | 174 | struct strbuf cmd = STRBUF_INIT; |
ef45bb1f JH |
175 | struct strbuf_expand_dict_entry dict[6]; |
176 | struct strbuf path_sq = STRBUF_INIT; | |
ac0ba18d | 177 | const char *args[] = { NULL, NULL }; |
525ab639 JH |
178 | int status, fd, i; |
179 | struct stat st; | |
712516bc | 180 | assert(opts); |
525ab639 | 181 | |
ef45bb1f | 182 | sq_quote_buf(&path_sq, path); |
66dbfd55 GV |
183 | dict[0].placeholder = "O"; dict[0].value = temp[0]; |
184 | dict[1].placeholder = "A"; dict[1].value = temp[1]; | |
185 | dict[2].placeholder = "B"; dict[2].value = temp[2]; | |
186 | dict[3].placeholder = "L"; dict[3].value = temp[3]; | |
ef45bb1f JH |
187 | dict[4].placeholder = "P"; dict[4].value = path_sq.buf; |
188 | dict[5].placeholder = NULL; dict[5].value = NULL; | |
66dbfd55 | 189 | |
525ab639 JH |
190 | if (fn->cmdline == NULL) |
191 | die("custom merge driver %s lacks command line.", fn->name); | |
192 | ||
193 | result->ptr = NULL; | |
194 | result->size = 0; | |
5096d490 JK |
195 | create_temp(orig, temp[0], sizeof(temp[0])); |
196 | create_temp(src1, temp[1], sizeof(temp[1])); | |
197 | create_temp(src2, temp[2], sizeof(temp[2])); | |
198 | xsnprintf(temp[3], sizeof(temp[3]), "%d", marker_size); | |
525ab639 | 199 | |
ced621b2 | 200 | strbuf_expand(&cmd, fn->cmdline, strbuf_expand_dict_cb, &dict); |
525ab639 | 201 | |
ac0ba18d JK |
202 | args[0] = cmd.buf; |
203 | status = run_command_v_opt(args, RUN_USING_SHELL); | |
525ab639 JH |
204 | fd = open(temp[1], O_RDONLY); |
205 | if (fd < 0) | |
206 | goto bad; | |
207 | if (fstat(fd, &st)) | |
208 | goto close_bad; | |
209 | result->size = st.st_size; | |
3733e694 | 210 | result->ptr = xmallocz(result->size); |
525ab639 JH |
211 | if (read_in_full(fd, result->ptr, result->size) != result->size) { |
212 | free(result->ptr); | |
213 | result->ptr = NULL; | |
214 | result->size = 0; | |
215 | } | |
216 | close_bad: | |
217 | close(fd); | |
218 | bad: | |
219 | for (i = 0; i < 3; i++) | |
691f1a28 | 220 | unlink_or_warn(temp[i]); |
ced621b2 | 221 | strbuf_release(&cmd); |
ef45bb1f | 222 | strbuf_release(&path_sq); |
525ab639 JH |
223 | return status; |
224 | } | |
225 | ||
226 | /* | |
227 | * merge.default and merge.driver configuration items | |
228 | */ | |
229 | static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail; | |
230 | static const char *default_ll_merge; | |
231 | ||
ef90d6d4 | 232 | static int read_merge_config(const char *var, const char *value, void *cb) |
525ab639 JH |
233 | { |
234 | struct ll_merge_driver *fn; | |
d731f0ad | 235 | const char *key, *name; |
525ab639 JH |
236 | int namelen; |
237 | ||
6ea358f7 TA |
238 | if (!strcmp(var, "merge.default")) |
239 | return git_config_string(&default_ll_merge, var, value); | |
525ab639 JH |
240 | |
241 | /* | |
242 | * We are not interested in anything but "merge.<name>.variable"; | |
243 | * especially, we do not want to look at variables such as | |
244 | * "merge.summary", "merge.tool", and "merge.verbosity". | |
245 | */ | |
d731f0ad | 246 | if (parse_config_key(var, "merge", &name, &namelen, &key) < 0 || !name) |
525ab639 JH |
247 | return 0; |
248 | ||
249 | /* | |
250 | * Find existing one as we might be processing merge.<name>.var2 | |
251 | * after seeing merge.<name>.var1. | |
252 | */ | |
525ab639 JH |
253 | for (fn = ll_user_merge; fn; fn = fn->next) |
254 | if (!strncmp(fn->name, name, namelen) && !fn->name[namelen]) | |
255 | break; | |
256 | if (!fn) { | |
257 | fn = xcalloc(1, sizeof(struct ll_merge_driver)); | |
258 | fn->name = xmemdupz(name, namelen); | |
259 | fn->fn = ll_ext_merge; | |
260 | *ll_user_merge_tail = fn; | |
261 | ll_user_merge_tail = &(fn->next); | |
262 | } | |
263 | ||
6ea358f7 TA |
264 | if (!strcmp("name", key)) |
265 | return git_config_string(&fn->description, var, value); | |
525ab639 | 266 | |
d731f0ad | 267 | if (!strcmp("driver", key)) { |
525ab639 JH |
268 | if (!value) |
269 | return error("%s: lacks value", var); | |
270 | /* | |
271 | * merge.<name>.driver specifies the command line: | |
272 | * | |
273 | * command-line | |
274 | * | |
275 | * The command-line will be interpolated with the following | |
276 | * tokens and is given to the shell: | |
277 | * | |
278 | * %O - temporary file name for the merge base. | |
279 | * %A - temporary file name for our version. | |
280 | * %B - temporary file name for the other branches' version. | |
23a64c9e | 281 | * %L - conflict marker length |
ef45bb1f | 282 | * %P - the original path (safely quoted for the shell) |
525ab639 JH |
283 | * |
284 | * The external merge driver should write the results in the | |
285 | * file named by %A, and signal that it has done with zero exit | |
286 | * status. | |
287 | */ | |
90dce515 | 288 | fn->cmdline = xstrdup(value); |
525ab639 JH |
289 | return 0; |
290 | } | |
291 | ||
6ea358f7 TA |
292 | if (!strcmp("recursive", key)) |
293 | return git_config_string(&fn->recursive, var, value); | |
525ab639 JH |
294 | |
295 | return 0; | |
296 | } | |
297 | ||
298 | static void initialize_ll_merge(void) | |
299 | { | |
300 | if (ll_user_merge_tail) | |
301 | return; | |
302 | ll_user_merge_tail = &ll_user_merge; | |
ef90d6d4 | 303 | git_config(read_merge_config, NULL); |
525ab639 JH |
304 | } |
305 | ||
306 | static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr) | |
307 | { | |
308 | struct ll_merge_driver *fn; | |
309 | const char *name; | |
310 | int i; | |
311 | ||
312 | initialize_ll_merge(); | |
313 | ||
314 | if (ATTR_TRUE(merge_attr)) | |
315 | return &ll_merge_drv[LL_TEXT_MERGE]; | |
316 | else if (ATTR_FALSE(merge_attr)) | |
317 | return &ll_merge_drv[LL_BINARY_MERGE]; | |
318 | else if (ATTR_UNSET(merge_attr)) { | |
319 | if (!default_ll_merge) | |
320 | return &ll_merge_drv[LL_TEXT_MERGE]; | |
321 | else | |
322 | name = default_ll_merge; | |
323 | } | |
324 | else | |
325 | name = merge_attr; | |
326 | ||
327 | for (fn = ll_user_merge; fn; fn = fn->next) | |
328 | if (!strcmp(fn->name, name)) | |
329 | return fn; | |
330 | ||
331 | for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++) | |
332 | if (!strcmp(ll_merge_drv[i].name, name)) | |
333 | return &ll_merge_drv[i]; | |
334 | ||
335 | /* default to the 3-way */ | |
336 | return &ll_merge_drv[LL_TEXT_MERGE]; | |
337 | } | |
338 | ||
23a64c9e | 339 | static int git_path_check_merge(const char *path, struct git_attr_check check[2]) |
525ab639 | 340 | { |
23a64c9e JH |
341 | if (!check[0].attr) { |
342 | check[0].attr = git_attr("merge"); | |
343 | check[1].attr = git_attr("conflict-marker-size"); | |
344 | } | |
d932f4eb | 345 | return git_check_attr(path, 2, check); |
525ab639 JH |
346 | } |
347 | ||
f217f0e8 EB |
348 | static void normalize_file(mmfile_t *mm, const char *path) |
349 | { | |
350 | struct strbuf strbuf = STRBUF_INIT; | |
351 | if (renormalize_buffer(path, mm->ptr, mm->size, &strbuf)) { | |
352 | free(mm->ptr); | |
353 | mm->size = strbuf.len; | |
354 | mm->ptr = strbuf_detach(&strbuf, NULL); | |
355 | } | |
356 | } | |
357 | ||
525ab639 JH |
358 | int ll_merge(mmbuffer_t *result_buf, |
359 | const char *path, | |
f01de62e | 360 | mmfile_t *ancestor, const char *ancestor_label, |
525ab639 JH |
361 | mmfile_t *ours, const char *our_label, |
362 | mmfile_t *theirs, const char *their_label, | |
712516bc | 363 | const struct ll_merge_options *opts) |
525ab639 | 364 | { |
23a64c9e | 365 | static struct git_attr_check check[2]; |
4fb40c2b | 366 | static const struct ll_merge_options default_opts; |
23a64c9e JH |
367 | const char *ll_driver_name = NULL; |
368 | int marker_size = DEFAULT_CONFLICT_MARKER_SIZE; | |
525ab639 JH |
369 | const struct ll_merge_driver *driver; |
370 | ||
4fb40c2b JN |
371 | if (!opts) |
372 | opts = &default_opts; | |
712516bc JN |
373 | |
374 | if (opts->renormalize) { | |
f217f0e8 EB |
375 | normalize_file(ancestor, path); |
376 | normalize_file(ours, path); | |
377 | normalize_file(theirs, path); | |
378 | } | |
23a64c9e JH |
379 | if (!git_path_check_merge(path, check)) { |
380 | ll_driver_name = check[0].value; | |
381 | if (check[1].value) { | |
382 | marker_size = atoi(check[1].value); | |
383 | if (marker_size <= 0) | |
384 | marker_size = DEFAULT_CONFLICT_MARKER_SIZE; | |
385 | } | |
386 | } | |
525ab639 | 387 | driver = find_ll_merge_driver(ll_driver_name); |
d694a179 JH |
388 | |
389 | if (opts->virtual_ancestor) { | |
390 | if (driver->recursive) | |
391 | driver = find_ll_merge_driver(driver->recursive); | |
392 | marker_size += 2; | |
393 | } | |
f01de62e | 394 | return driver->fn(driver, result_buf, path, ancestor, ancestor_label, |
23a64c9e | 395 | ours, our_label, theirs, their_label, |
712516bc | 396 | opts, marker_size); |
525ab639 | 397 | } |
8588567c JH |
398 | |
399 | int ll_merge_marker_size(const char *path) | |
400 | { | |
401 | static struct git_attr_check check; | |
402 | int marker_size = DEFAULT_CONFLICT_MARKER_SIZE; | |
403 | ||
404 | if (!check.attr) | |
405 | check.attr = git_attr("conflict-marker-size"); | |
d932f4eb | 406 | if (!git_check_attr(path, 1, &check) && check.value) { |
8588567c JH |
407 | marker_size = atoi(check.value); |
408 | if (marker_size <= 0) | |
409 | marker_size = DEFAULT_CONFLICT_MARKER_SIZE; | |
410 | } | |
411 | return marker_size; | |
525ab639 | 412 | } |