2 * Low level 3-way in-core file merge.
4 * Copyright (c) 2007 Junio C Hamano
9 #include "xdiff-interface.h"
10 #include "run-command.h"
13 struct ll_merge_driver
;
15 typedef int (*ll_merge_fn
)(const struct ll_merge_driver
*,
19 mmfile_t
*src1
, const char *name1
,
20 mmfile_t
*src2
, const char *name2
,
24 struct ll_merge_driver
{
26 const char *description
;
28 const char *recursive
;
29 struct ll_merge_driver
*next
;
36 static int ll_binary_merge(const struct ll_merge_driver
*drv_unused
,
38 const char *path_unused
,
40 mmfile_t
*src1
, const char *name1
,
41 mmfile_t
*src2
, const char *name2
,
42 int flag
, int marker_size
)
45 * The tentative merge result is "ours" for the final round,
46 * or common ancestor for an internal merge. Still return
47 * "conflicted merge" status.
49 mmfile_t
*stolen
= (flag
& 01) ? orig
: src1
;
51 result
->ptr
= stolen
->ptr
;
52 result
->size
= stolen
->size
;
57 static int ll_xdl_merge(const struct ll_merge_driver
*drv_unused
,
61 mmfile_t
*src1
, const char *name1
,
62 mmfile_t
*src2
, const char *name2
,
63 int flag
, int marker_size
)
67 int favor
= (flag
>> 1) & 03;
69 if (buffer_is_binary(orig
->ptr
, orig
->size
) ||
70 buffer_is_binary(src1
->ptr
, src1
->size
) ||
71 buffer_is_binary(src2
->ptr
, src2
->size
)) {
72 warning("Cannot merge binary files: %s (%s vs. %s)\n",
74 return ll_binary_merge(drv_unused
, result
,
81 memset(&xmp
, 0, sizeof(xmp
));
82 if (git_xmerge_style
>= 0)
83 style
= git_xmerge_style
;
85 xmp
.marker_size
= marker_size
;
86 return xdl_merge(orig
,
89 &xmp
, XDL_MERGE_FLAGS(XDL_MERGE_ZEALOUS
, style
, favor
),
93 static int ll_union_merge(const struct ll_merge_driver
*drv_unused
,
95 const char *path_unused
,
97 mmfile_t
*src1
, const char *name1
,
98 mmfile_t
*src2
, const char *name2
,
99 int flag
, int marker_size
)
103 int status
, saved_style
;
105 /* We have to force the RCS "merge" style */
106 saved_style
= git_xmerge_style
;
107 git_xmerge_style
= 0;
108 status
= ll_xdl_merge(drv_unused
, result
, path_unused
,
109 orig
, src1
, NULL
, src2
, NULL
,
111 git_xmerge_style
= saved_style
;
115 src
= dst
= result
->ptr
;
118 if ((marker_size
< size
) &&
119 (*src
== '<' || *src
== '=' || *src
== '>')) {
122 for (i
= 0; i
< marker_size
; i
++)
125 if (src
[marker_size
] != '\n')
127 src
+= marker_size
+ 1;
128 size
-= marker_size
+ 1;
136 } while (ch
!= '\n' && size
);
138 result
->size
= dst
- result
->ptr
;
142 #define LL_BINARY_MERGE 0
143 #define LL_TEXT_MERGE 1
144 #define LL_UNION_MERGE 2
145 static struct ll_merge_driver ll_merge_drv
[] = {
146 { "binary", "built-in binary merge", ll_binary_merge
},
147 { "text", "built-in 3-way text merge", ll_xdl_merge
},
148 { "union", "built-in union merge", ll_union_merge
},
151 static void create_temp(mmfile_t
*src
, char *path
)
155 strcpy(path
, ".merge_file_XXXXXX");
157 if (write_in_full(fd
, src
->ptr
, src
->size
) != src
->size
)
158 die_errno("unable to write temp-file");
163 * User defined low-level merge driver support.
165 static int ll_ext_merge(const struct ll_merge_driver
*fn
,
169 mmfile_t
*src1
, const char *name1
,
170 mmfile_t
*src2
, const char *name2
,
171 int flag
, int marker_size
)
174 struct strbuf cmd
= STRBUF_INIT
;
175 struct strbuf_expand_dict_entry dict
[] = {
182 const char *args
[] = { NULL
, NULL
};
186 if (fn
->cmdline
== NULL
)
187 die("custom merge driver %s lacks command line.", fn
->name
);
191 create_temp(orig
, temp
[0]);
192 create_temp(src1
, temp
[1]);
193 create_temp(src2
, temp
[2]);
194 sprintf(temp
[3], "%d", marker_size
);
196 strbuf_expand(&cmd
, fn
->cmdline
, strbuf_expand_dict_cb
, &dict
);
199 status
= run_command_v_opt(args
, RUN_USING_SHELL
);
200 fd
= open(temp
[1], O_RDONLY
);
205 result
->size
= st
.st_size
;
206 result
->ptr
= xmalloc(result
->size
+ 1);
207 if (read_in_full(fd
, result
->ptr
, result
->size
) != result
->size
) {
215 for (i
= 0; i
< 3; i
++)
216 unlink_or_warn(temp
[i
]);
217 strbuf_release(&cmd
);
222 * merge.default and merge.driver configuration items
224 static struct ll_merge_driver
*ll_user_merge
, **ll_user_merge_tail
;
225 static const char *default_ll_merge
;
227 static int read_merge_config(const char *var
, const char *value
, void *cb
)
229 struct ll_merge_driver
*fn
;
230 const char *ep
, *name
;
233 if (!strcmp(var
, "merge.default")) {
235 default_ll_merge
= xstrdup(value
);
240 * We are not interested in anything but "merge.<name>.variable";
241 * especially, we do not want to look at variables such as
242 * "merge.summary", "merge.tool", and "merge.verbosity".
244 if (prefixcmp(var
, "merge.") || (ep
= strrchr(var
, '.')) == var
+ 5)
248 * Find existing one as we might be processing merge.<name>.var2
249 * after seeing merge.<name>.var1.
253 for (fn
= ll_user_merge
; fn
; fn
= fn
->next
)
254 if (!strncmp(fn
->name
, name
, namelen
) && !fn
->name
[namelen
])
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
);
266 if (!strcmp("name", ep
)) {
268 return error("%s: lacks value", var
);
269 fn
->description
= xstrdup(value
);
273 if (!strcmp("driver", ep
)) {
275 return error("%s: lacks value", var
);
277 * merge.<name>.driver specifies the command line:
281 * The command-line will be interpolated with the following
282 * tokens and is given to the shell:
284 * %O - temporary file name for the merge base.
285 * %A - temporary file name for our version.
286 * %B - temporary file name for the other branches' version.
287 * %L - conflict marker length
289 * The external merge driver should write the results in the
290 * file named by %A, and signal that it has done with zero exit
293 fn
->cmdline
= xstrdup(value
);
297 if (!strcmp("recursive", ep
)) {
299 return error("%s: lacks value", var
);
300 fn
->recursive
= xstrdup(value
);
307 static void initialize_ll_merge(void)
309 if (ll_user_merge_tail
)
311 ll_user_merge_tail
= &ll_user_merge
;
312 git_config(read_merge_config
, NULL
);
315 static const struct ll_merge_driver
*find_ll_merge_driver(const char *merge_attr
)
317 struct ll_merge_driver
*fn
;
321 initialize_ll_merge();
323 if (ATTR_TRUE(merge_attr
))
324 return &ll_merge_drv
[LL_TEXT_MERGE
];
325 else if (ATTR_FALSE(merge_attr
))
326 return &ll_merge_drv
[LL_BINARY_MERGE
];
327 else if (ATTR_UNSET(merge_attr
)) {
328 if (!default_ll_merge
)
329 return &ll_merge_drv
[LL_TEXT_MERGE
];
331 name
= default_ll_merge
;
336 for (fn
= ll_user_merge
; fn
; fn
= fn
->next
)
337 if (!strcmp(fn
->name
, name
))
340 for (i
= 0; i
< ARRAY_SIZE(ll_merge_drv
); i
++)
341 if (!strcmp(ll_merge_drv
[i
].name
, name
))
342 return &ll_merge_drv
[i
];
344 /* default to the 3-way */
345 return &ll_merge_drv
[LL_TEXT_MERGE
];
348 static int git_path_check_merge(const char *path
, struct git_attr_check check
[2])
350 if (!check
[0].attr
) {
351 check
[0].attr
= git_attr("merge");
352 check
[1].attr
= git_attr("conflict-marker-size");
354 return git_checkattr(path
, 2, check
);
357 int ll_merge(mmbuffer_t
*result_buf
,
360 mmfile_t
*ours
, const char *our_label
,
361 mmfile_t
*theirs
, const char *their_label
,
364 static struct git_attr_check check
[2];
365 const char *ll_driver_name
= NULL
;
366 int marker_size
= DEFAULT_CONFLICT_MARKER_SIZE
;
367 const struct ll_merge_driver
*driver
;
368 int virtual_ancestor
= flag
& 01;
370 if (!git_path_check_merge(path
, check
)) {
371 ll_driver_name
= check
[0].value
;
372 if (check
[1].value
) {
373 marker_size
= atoi(check
[1].value
);
374 if (marker_size
<= 0)
375 marker_size
= DEFAULT_CONFLICT_MARKER_SIZE
;
378 driver
= find_ll_merge_driver(ll_driver_name
);
379 if (virtual_ancestor
&& driver
->recursive
)
380 driver
= find_ll_merge_driver(driver
->recursive
);
381 return driver
->fn(driver
, result_buf
, path
, ancestor
,
382 ours
, our_label
, theirs
, their_label
,
386 int ll_merge_marker_size(const char *path
)
388 static struct git_attr_check check
;
389 int marker_size
= DEFAULT_CONFLICT_MARKER_SIZE
;
392 check
.attr
= git_attr("conflict-marker-size");
393 if (!git_checkattr(path
, 1, &check
) && check
.value
) {
394 marker_size
= atoi(check
.value
);
395 if (marker_size
<= 0)
396 marker_size
= DEFAULT_CONFLICT_MARKER_SIZE
;