vendor/libgit2-sys/libgit2/src/merge_file.c - toolchain/rustc - Git at Google

 /*
  * 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 "fileops.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)

 int git_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 = git_merge_file__input_from_index(
 			&ancestor_input, &odb_object[0], odb, ancestor)) < 0)
 			goto done;

 		ancestor_ptr = &ancestor_input;
 	}

 	if ((error = git_merge_file__input_from_index(
 			&our_input, &odb_object[1], odb, ours)) < 0 ||
 		(error = git_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);
 }
	/*
	* 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 "fileops.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)

	int git_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 = git_merge_file__input_from_index(
	&ancestor_input, &odb_object[0], odb, ancestor)) < 0)
	goto done;

	ancestor_ptr = &ancestor_input;
	}

	if ((error = git_merge_file__input_from_index(
	&our_input, &odb_object[1], odb, ours)) < 0 \|\|
	(error = git_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);
	}