[libgit2.git] / src / merge_file.c

/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */

#include "common.h"

#include "repository.h"
#include "posix.h"
#include "futils.h"
#include "index.h"
#include "diff_xdiff.h"
#include "merge.h"

#include "git2/repository.h"
#include "git2/object.h"
#include "git2/index.h"
#include "git2/merge.h"

#include "xdiff/xdiff.h"

/* only examine the first 8000 bytes for binaryness.
 * https://github.com/git/git/blob/77bd3ea9f54f1584147b594abc04c26ca516d987/xdiff-interface.c#L197
 */
#define GIT_MERGE_FILE_BINARY_SIZE 8000

#define GIT_MERGE_FILE_SIDE_EXISTS(X)	((X)->mode != 0)

static int merge_file_input_from_index(
	git_merge_file_input *input_out,
	git_odb_object **odb_object_out,
	git_odb *odb,
	const git_index_entry *entry)
{
	int error = 0;

	assert(input_out && odb_object_out && odb && entry);

	if ((error = git_odb_read(odb_object_out, odb, &entry->id)) < 0)
		goto done;

	input_out->path = entry->path;
	input_out->mode = entry->mode;
	input_out->ptr = (char *)git_odb_object_data(*odb_object_out);
	input_out->size = git_odb_object_size(*odb_object_out);

done:
	return error;
}

static void merge_file_normalize_opts(
	git_merge_file_options *out,
	const git_merge_file_options *given_opts)
{
	if (given_opts)
		memcpy(out, given_opts, sizeof(git_merge_file_options));
	else {
		git_merge_file_options default_opts = GIT_MERGE_FILE_OPTIONS_INIT;
		memcpy(out, &default_opts, sizeof(git_merge_file_options));
	}
}

static int merge_file__xdiff(
	git_merge_file_result *out,
	const git_merge_file_input *ancestor,
	const git_merge_file_input *ours,
	const git_merge_file_input *theirs,
	const git_merge_file_options *given_opts)
{
	xmparam_t xmparam;
	mmfile_t ancestor_mmfile = {0}, our_mmfile = {0}, their_mmfile = {0};
	mmbuffer_t mmbuffer;
	git_merge_file_options options = GIT_MERGE_FILE_OPTIONS_INIT;
	const char *path;
	int xdl_result;
	int error = 0;

	memset(out, 0x0, sizeof(git_merge_file_result));

	merge_file_normalize_opts(&options, given_opts);

	memset(&xmparam, 0x0, sizeof(xmparam_t));

	if (ancestor) {
		xmparam.ancestor = (options.ancestor_label) ?
			options.ancestor_label : ancestor->path;
		ancestor_mmfile.ptr = (char *)ancestor->ptr;
		ancestor_mmfile.size = ancestor->size;
	}

	xmparam.file1 = (options.our_label) ?
		options.our_label : ours->path;
	our_mmfile.ptr = (char *)ours->ptr;
	our_mmfile.size = ours->size;

	xmparam.file2 = (options.their_label) ?
		options.their_label : theirs->path;
	their_mmfile.ptr = (char *)theirs->ptr;
	their_mmfile.size = theirs->size;

	if (options.favor == GIT_MERGE_FILE_FAVOR_OURS)
		xmparam.favor = XDL_MERGE_FAVOR_OURS;
	else if (options.favor == GIT_MERGE_FILE_FAVOR_THEIRS)
		xmparam.favor = XDL_MERGE_FAVOR_THEIRS;
	else if (options.favor == GIT_MERGE_FILE_FAVOR_UNION)
		xmparam.favor = XDL_MERGE_FAVOR_UNION;

	xmparam.level = (options.flags & GIT_MERGE_FILE_SIMPLIFY_ALNUM) ?
		XDL_MERGE_ZEALOUS_ALNUM : XDL_MERGE_ZEALOUS;

	if (options.flags & GIT_MERGE_FILE_STYLE_DIFF3)
		xmparam.style = XDL_MERGE_DIFF3;

	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE)
		xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE;
	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_CHANGE)
		xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE_CHANGE;
	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_EOL)
		xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE_AT_EOL;

	if (options.flags & GIT_MERGE_FILE_DIFF_PATIENCE)
		xmparam.xpp.flags |= XDF_PATIENCE_DIFF;

	if (options.flags & GIT_MERGE_FILE_DIFF_MINIMAL)
		xmparam.xpp.flags |= XDF_NEED_MINIMAL;

	xmparam.marker_size = options.marker_size;

	if ((xdl_result = xdl_merge(&ancestor_mmfile, &our_mmfile,
		&their_mmfile, &xmparam, &mmbuffer)) < 0) {
		git_error_set(GIT_ERROR_MERGE, "failed to merge files");
		error = -1;
		goto done;
	}

	path = git_merge_file__best_path(
		ancestor ? ancestor->path : NULL,
		ours->path,
		theirs->path);

	if (path != NULL && (out->path = git__strdup(path)) == NULL) {
		error = -1;
		goto done;
	}

	out->automergeable = (xdl_result == 0);
	out->ptr = (const char *)mmbuffer.ptr;
	out->len = mmbuffer.size;
	out->mode = git_merge_file__best_mode(
		ancestor ? ancestor->mode : 0,
		ours->mode,
		theirs->mode);

done:
	if (error < 0)
		git_merge_file_result_free(out);

	return error;
}

static bool merge_file__is_binary(const git_merge_file_input *file)
{
	size_t len = file ? file->size : 0;

	if (len > GIT_XDIFF_MAX_SIZE)
		return true;
	if (len > GIT_MERGE_FILE_BINARY_SIZE)
		len = GIT_MERGE_FILE_BINARY_SIZE;

	return len ? (memchr(file->ptr, 0, len) != NULL) : false;
}

static int merge_file__binary(
	git_merge_file_result *out,
	const git_merge_file_input *ours,
	const git_merge_file_input *theirs,
	const git_merge_file_options *given_opts)
{
	const git_merge_file_input *favored = NULL;

	memset(out, 0x0, sizeof(git_merge_file_result));

	if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_OURS)
		favored = ours;
	else if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_THEIRS)
		favored = theirs;
	else
		goto done;

	if ((out->path = git__strdup(favored->path)) == NULL ||
		(out->ptr = git__malloc(favored->size)) == NULL)
		goto done;

	memcpy((char *)out->ptr, favored->ptr, favored->size);
	out->len = favored->size;
	out->mode = favored->mode;
	out->automergeable = 1;

done:
	return 0;
}

static int merge_file__from_inputs(
	git_merge_file_result *out,
	const git_merge_file_input *ancestor,
	const git_merge_file_input *ours,
	const git_merge_file_input *theirs,
	const git_merge_file_options *given_opts)
{
	if (merge_file__is_binary(ancestor) ||
		merge_file__is_binary(ours) ||
		merge_file__is_binary(theirs))
		return merge_file__binary(out, ours, theirs, given_opts);

	return merge_file__xdiff(out, ancestor, ours, theirs, given_opts);
}

static git_merge_file_input *git_merge_file__normalize_inputs(
	git_merge_file_input *out,
	const git_merge_file_input *given)
{
	memcpy(out, given, sizeof(git_merge_file_input));

	if (!out->path)
		out->path = "file.txt";

	if (!out->mode)
		out->mode = 0100644;

	return out;
}

int git_merge_file(
	git_merge_file_result *out,
	const git_merge_file_input *ancestor,
	const git_merge_file_input *ours,
	const git_merge_file_input *theirs,
	const git_merge_file_options *options)
{
	git_merge_file_input inputs[3] = { {0} };

	assert(out && ours && theirs);

	memset(out, 0x0, sizeof(git_merge_file_result));

	if (ancestor)
		ancestor = git_merge_file__normalize_inputs(&inputs[0], ancestor);

	ours = git_merge_file__normalize_inputs(&inputs[1], ours);
	theirs = git_merge_file__normalize_inputs(&inputs[2], theirs);

	return merge_file__from_inputs(out, ancestor, ours, theirs, options);
}

int git_merge_file_from_index(
	git_merge_file_result *out,
	git_repository *repo,
	const git_index_entry *ancestor,
	const git_index_entry *ours,
	const git_index_entry *theirs,
	const git_merge_file_options *options)
{
	git_merge_file_input *ancestor_ptr = NULL,
		ancestor_input = {0}, our_input = {0}, their_input = {0};
	git_odb *odb = NULL;
	git_odb_object *odb_object[3] = { 0 };
	int error = 0;

	assert(out && repo && ours && theirs);

	memset(out, 0x0, sizeof(git_merge_file_result));

	if ((error = git_repository_odb(&odb, repo)) < 0)
		goto done;

	if (ancestor) {
		if ((error = merge_file_input_from_index(
			&ancestor_input, &odb_object[0], odb, ancestor)) < 0)
			goto done;

		ancestor_ptr = &ancestor_input;
	}

	if ((error = merge_file_input_from_index(&our_input, &odb_object[1], odb, ours)) < 0 ||
	    (error = merge_file_input_from_index(&their_input, &odb_object[2], odb, theirs)) < 0)
		goto done;

	error = merge_file__from_inputs(out,
		ancestor_ptr, &our_input, &their_input, options);

done:
	git_odb_object_free(odb_object[0]);
	git_odb_object_free(odb_object[1]);
	git_odb_object_free(odb_object[2]);
	git_odb_free(odb);

	return error;
}

void git_merge_file_result_free(git_merge_file_result *result)
{
	if (result == NULL)
		return;

	git__free((char *)result->path);
	git__free((char *)result->ptr);
}
Commit	Line	Data
bec65a5e ET	1	/*
	2	* Copyright (C) the libgit2 contributors. All rights reserved.
	3	*
	4	* This file is part of libgit2, distributed under the GNU GPL v2 with
	5	* a Linking Exception. For full terms see the included COPYING file.
	6	*/
	7
	8	#include "common.h"
eae0bfdc	9
bec65a5e	10	#include "repository.h"
05d47768	11	#include "posix.h"
22a2d3d5	12	#include "futils.h"
05d47768	13	#include "index.h"
6c014bcc	14	#include "diff_xdiff.h"
3f04219f	15	#include "merge.h"
bec65a5e ET	16
	17	#include "git2/repository.h"
	18	#include "git2/object.h"
	19	#include "git2/index.h"
e4352066	20	#include "git2/merge.h"
bec65a5e ET	21
	22	#include "xdiff/xdiff.h"
	23
e4352066 ET	24	/* only examine the first 8000 bytes for binaryness.
	25	* https://github.com/git/git/blob/77bd3ea9f54f1584147b594abc04c26ca516d987/xdiff-interface.c#L197
	26	*/
	27	#define GIT_MERGE_FILE_BINARY_SIZE 8000
	28
bec65a5e ET	29	#define GIT_MERGE_FILE_SIDE_EXISTS(X) ((X)->mode != 0)
bec65a5e ET	30
22a2d3d5	31	static int merge_file_input_from_index(
05d47768 ET	32	git_merge_file_input *input_out,
	33	git_odb_object **odb_object_out,
	34	git_odb *odb,
bec65a5e ET	35	const git_index_entry *entry)
bec65a5e ET	36	{
bec65a5e	37	int error = 0;
1fed6b07	38
05d47768	39	assert(input_out && odb_object_out && odb && entry);
1fed6b07	40
05d47768	41	if ((error = git_odb_read(odb_object_out, odb, &entry->id)) < 0)
bec65a5e	42	goto done;
1fed6b07	43
05d47768 ET	44	input_out->path = entry->path;
	45	input_out->mode = entry->mode;
	46	input_out->ptr = (char )git_odb_object_data(odb_object_out);
	47	input_out->size = git_odb_object_size(*odb_object_out);
1fed6b07	48
bec65a5e	49	done:
bec65a5e ET	50	return error;
	51	}
	52
05d47768 ET	53	static void merge_file_normalize_opts(
	54	git_merge_file_options *out,
	55	const git_merge_file_options *given_opts)
bec65a5e	56	{
05d47768 ET	57	if (given_opts)
	58	memcpy(out, given_opts, sizeof(git_merge_file_options));
	59	else {
	60	git_merge_file_options default_opts = GIT_MERGE_FILE_OPTIONS_INIT;
	61	memcpy(out, &default_opts, sizeof(git_merge_file_options));
	62	}
bec65a5e ET	63	}
bec65a5e ET	64
e4352066	65	static int merge_file__xdiff(
bec65a5e	66	git_merge_file_result *out,
05d47768 ET	67	const git_merge_file_input *ancestor,
	68	const git_merge_file_input *ours,
	69	const git_merge_file_input *theirs,
	70	const git_merge_file_options *given_opts)
bec65a5e ET	71	{
bec65a5e ET	72	xmparam_t xmparam;
05d47768	73	mmfile_t ancestor_mmfile = {0}, our_mmfile = {0}, their_mmfile = {0};
bec65a5e	74	mmbuffer_t mmbuffer;
05d47768 ET	75	git_merge_file_options options = GIT_MERGE_FILE_OPTIONS_INIT;
05d47768 ET	76	const char *path;
bec65a5e ET	77	int xdl_result;
	78	int error = 0;
	79
bec65a5e ET	80	memset(out, 0x0, sizeof(git_merge_file_result));
bec65a5e ET	81
7dcd42a5	82	merge_file_normalize_opts(&options, given_opts);
1fed6b07	83
bec65a5e	84	memset(&xmparam, 0x0, sizeof(xmparam_t));
bec65a5e	85
05d47768 ET	86	if (ancestor) {
	87	xmparam.ancestor = (options.ancestor_label) ?
	88	options.ancestor_label : ancestor->path;
	89	ancestor_mmfile.ptr = (char *)ancestor->ptr;
	90	ancestor_mmfile.size = ancestor->size;
	91	}
bec65a5e	92
05d47768 ET	93	xmparam.file1 = (options.our_label) ?
	94	options.our_label : ours->path;
	95	our_mmfile.ptr = (char *)ours->ptr;
	96	our_mmfile.size = ours->size;
	97
	98	xmparam.file2 = (options.their_label) ?
	99	options.their_label : theirs->path;
	100	their_mmfile.ptr = (char *)theirs->ptr;
	101	their_mmfile.size = theirs->size;
	102
	103	if (options.favor == GIT_MERGE_FILE_FAVOR_OURS)
bec65a5e	104	xmparam.favor = XDL_MERGE_FAVOR_OURS;
05d47768	105	else if (options.favor == GIT_MERGE_FILE_FAVOR_THEIRS)
bec65a5e	106	xmparam.favor = XDL_MERGE_FAVOR_THEIRS;
05d47768	107	else if (options.favor == GIT_MERGE_FILE_FAVOR_UNION)
db3462ce	108	xmparam.favor = XDL_MERGE_FAVOR_UNION;
bec65a5e	109
05d47768	110	xmparam.level = (options.flags & GIT_MERGE_FILE_SIMPLIFY_ALNUM) ?
c1d648c5 ET	111	XDL_MERGE_ZEALOUS_ALNUM : XDL_MERGE_ZEALOUS;
c1d648c5 ET	112
05d47768	113	if (options.flags & GIT_MERGE_FILE_STYLE_DIFF3)
e651e8e2 ET	114	xmparam.style = XDL_MERGE_DIFF3;
e651e8e2 ET	115
13de9363	116	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE)
45a86bbf	117	xmparam.xpp.flags \|= XDF_IGNORE_WHITESPACE;
13de9363	118	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_CHANGE)
45a86bbf	119	xmparam.xpp.flags \|= XDF_IGNORE_WHITESPACE_CHANGE;
13de9363	120	if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_EOL)
45a86bbf JG	121	xmparam.xpp.flags \|= XDF_IGNORE_WHITESPACE_AT_EOL;
45a86bbf JG	122
74c37c2a JG	123	if (options.flags & GIT_MERGE_FILE_DIFF_PATIENCE)
	124	xmparam.xpp.flags \|= XDF_PATIENCE_DIFF;
	125
	126	if (options.flags & GIT_MERGE_FILE_DIFF_MINIMAL)
	127	xmparam.xpp.flags \|= XDF_NEED_MINIMAL;
	128
eae0bfdc PP	129	xmparam.marker_size = options.marker_size;
eae0bfdc PP	130
05d47768 ET	131	if ((xdl_result = xdl_merge(&ancestor_mmfile, &our_mmfile,
05d47768 ET	132	&their_mmfile, &xmparam, &mmbuffer)) < 0) {
ac3d33df	133	git_error_set(GIT_ERROR_MERGE, "failed to merge files");
bec65a5e ET	134	error = -1;
	135	goto done;
	136	}
1fed6b07	137
3f04219f ET	138	path = git_merge_file__best_path(
3f04219f ET	139	ancestor ? ancestor->path : NULL,
fcd1b786 PS	140	ours->path,
fcd1b786 PS	141	theirs->path);
3f04219f ET	142
3f04219f ET	143	if (path != NULL && (out->path = git__strdup(path)) == NULL) {
05d47768 ET	144	error = -1;
	145	goto done;
	146	}
	147
bec65a5e	148	out->automergeable = (xdl_result == 0);
7dcd42a5	149	out->ptr = (const char *)mmbuffer.ptr;
bec65a5e	150	out->len = mmbuffer.size;
3f04219f ET	151	out->mode = git_merge_file__best_mode(
3f04219f ET	152	ancestor ? ancestor->mode : 0,
fcd1b786 PS	153	ours->mode,
fcd1b786 PS	154	theirs->mode);
bec65a5e ET	155
bec65a5e ET	156	done:
05d47768 ET	157	if (error < 0)
	158	git_merge_file_result_free(out);
	159
bec65a5e ET	160	return error;
bec65a5e ET	161	}
05d47768	162
e4352066 ET	163	static bool merge_file__is_binary(const git_merge_file_input *file)
	164	{
	165	size_t len = file ? file->size : 0;
	166
6c014bcc	167	if (len > GIT_XDIFF_MAX_SIZE)
e4352066 ET	168	return true;
	169	if (len > GIT_MERGE_FILE_BINARY_SIZE)
	170	len = GIT_MERGE_FILE_BINARY_SIZE;
	171
	172	return len ? (memchr(file->ptr, 0, len) != NULL) : false;
	173	}
	174
	175	static int merge_file__binary(
	176	git_merge_file_result *out,
	177	const git_merge_file_input *ours,
	178	const git_merge_file_input *theirs,
	179	const git_merge_file_options *given_opts)
	180	{
	181	const git_merge_file_input *favored = NULL;
	182
	183	memset(out, 0x0, sizeof(git_merge_file_result));
	184
	185	if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_OURS)
	186	favored = ours;
	187	else if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_THEIRS)
	188	favored = theirs;
	189	else
	190	goto done;
	191
	192	if ((out->path = git__strdup(favored->path)) == NULL \|\|
	193	(out->ptr = git__malloc(favored->size)) == NULL)
	194	goto done;
	195
	196	memcpy((char *)out->ptr, favored->ptr, favored->size);
	197	out->len = favored->size;
	198	out->mode = favored->mode;
	199	out->automergeable = 1;
	200
	201	done:
	202	return 0;
	203	}
	204
	205	static int merge_file__from_inputs(
	206	git_merge_file_result *out,
	207	const git_merge_file_input *ancestor,
	208	const git_merge_file_input *ours,
	209	const git_merge_file_input *theirs,
	210	const git_merge_file_options *given_opts)
	211	{
	212	if (merge_file__is_binary(ancestor) \|\|
	213	merge_file__is_binary(ours) \|\|
	214	merge_file__is_binary(theirs))
	215	return merge_file__binary(out, ours, theirs, given_opts);
	216
	217	return merge_file__xdiff(out, ancestor, ours, theirs, given_opts);
	218	}
	219
05d47768 ET	220	static git_merge_file_input *git_merge_file__normalize_inputs(
	221	git_merge_file_input *out,
	222	const git_merge_file_input *given)
	223	{
	224	memcpy(out, given, sizeof(git_merge_file_input));
	225
	226	if (!out->path)
	227	out->path = "file.txt";
	228
	229	if (!out->mode)
	230	out->mode = 0100644;
	231
	232	return out;
	233	}
	234
	235	int git_merge_file(
	236	git_merge_file_result *out,
	237	const git_merge_file_input *ancestor,
	238	const git_merge_file_input *ours,
	239	const git_merge_file_input *theirs,
	240	const git_merge_file_options *options)
	241	{
	242	git_merge_file_input inputs[3] = { {0} };
	243
	244	assert(out && ours && theirs);
	245
	246	memset(out, 0x0, sizeof(git_merge_file_result));
	247
	248	if (ancestor)
	249	ancestor = git_merge_file__normalize_inputs(&inputs[0], ancestor);
	250
	251	ours = git_merge_file__normalize_inputs(&inputs[1], ours);
	252	theirs = git_merge_file__normalize_inputs(&inputs[2], theirs);
	253
e4352066	254	return merge_file__from_inputs(out, ancestor, ours, theirs, options);
05d47768 ET	255	}
	256
	257	int git_merge_file_from_index(
	258	git_merge_file_result *out,
	259	git_repository *repo,
	260	const git_index_entry *ancestor,
	261	const git_index_entry *ours,
	262	const git_index_entry *theirs,
	263	const git_merge_file_options *options)
	264	{
e4352066 ET	265	git_merge_file_input *ancestor_ptr = NULL,
e4352066 ET	266	ancestor_input = {0}, our_input = {0}, their_input = {0};
05d47768 ET	267	git_odb *odb = NULL;
	268	git_odb_object *odb_object[3] = { 0 };
	269	int error = 0;
	270
	271	assert(out && repo && ours && theirs);
	272
	273	memset(out, 0x0, sizeof(git_merge_file_result));
	274
	275	if ((error = git_repository_odb(&odb, repo)) < 0)
	276	goto done;
	277
	278	if (ancestor) {
22a2d3d5	279	if ((error = merge_file_input_from_index(
e4352066	280	&ancestor_input, &odb_object[0], odb, ancestor)) < 0)
05d47768 ET	281	goto done;
05d47768 ET	282
e4352066	283	ancestor_ptr = &ancestor_input;
05d47768 ET	284	}
05d47768 ET	285
22a2d3d5 UG	286	if ((error = merge_file_input_from_index(&our_input, &odb_object[1], odb, ours)) < 0 \|\|
22a2d3d5 UG	287	(error = merge_file_input_from_index(&their_input, &odb_object[2], odb, theirs)) < 0)
05d47768 ET	288	goto done;
05d47768 ET	289
e4352066 ET	290	error = merge_file__from_inputs(out,
e4352066 ET	291	ancestor_ptr, &our_input, &their_input, options);
05d47768 ET	292
	293	done:
	294	git_odb_object_free(odb_object[0]);
	295	git_odb_object_free(odb_object[1]);
	296	git_odb_object_free(odb_object[2]);
	297	git_odb_free(odb);
	298
	299	return error;
	300	}
	301
	302	void git_merge_file_result_free(git_merge_file_result *result)
	303	{
	304	if (result == NULL)
	305	return;
	306
7f930ded	307	git__free((char *)result->path);
e4352066	308	git__free((char *)result->ptr);
05d47768	309	}