vendor/libgit2-sys/libgit2/src/attr.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 "attr.h"

 #include "repository.h"
 #include "sysdir.h"
 #include "config.h"
 #include "attr_file.h"
 #include "ignore.h"
 #include "git2/oid.h"
 #include <ctype.h>

 const char *git_attr__true  = "[internal]__TRUE__";
 const char *git_attr__false = "[internal]__FALSE__";
 const char *git_attr__unset = "[internal]__UNSET__";

 git_attr_t git_attr_value(const char *attr)
 {
 	if (attr == NULL || attr == git_attr__unset)
 		return GIT_ATTR_UNSPECIFIED_T;

 	if (attr == git_attr__true)
 		return GIT_ATTR_TRUE_T;

 	if (attr == git_attr__false)
 		return GIT_ATTR_FALSE_T;

 	return GIT_ATTR_VALUE_T;
 }

 static int collect_attr_files(
 	git_repository *repo,
 	git_attr_session *attr_session,
 	uint32_t flags,
 	const char *path,
 	git_vector *files);

 static void release_attr_files(git_vector *files);

 int git_attr_get(
 	const char **value,
 	git_repository *repo,
 	uint32_t flags,
 	const char *pathname,
 	const char *name)
 {
 	int error;
 	git_attr_path path;
 	git_vector files = GIT_VECTOR_INIT;
 	size_t i, j;
 	git_attr_file *file;
 	git_attr_name attr;
 	git_attr_rule *rule;
 	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;

 	assert(value && repo && name);

 	*value = NULL;

 	if (git_repository_is_bare(repo))
 		dir_flag = GIT_DIR_FLAG_FALSE;

 	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
 		return -1;

 	if ((error = collect_attr_files(repo, NULL, flags, pathname, &files)) < 0)
 		goto cleanup;

 	memset(&attr, 0, sizeof(attr));
 	attr.name = name;
 	attr.name_hash = git_attr_file__name_hash(name);

 	git_vector_foreach(&files, i, file) {

 		git_attr_file__foreach_matching_rule(file, &path, j, rule) {
 			size_t pos;

 			if (!git_vector_bsearch(&pos, &rule->assigns, &attr)) {
 				*value = ((git_attr_assignment *)git_vector_get(
 							  &rule->assigns, pos))->value;
 				goto cleanup;
 			}
 		}
 	}

 cleanup:
 	release_attr_files(&files);
 	git_attr_path__free(&path);

 	return error;
 }


 typedef struct {
 	git_attr_name name;
 	git_attr_assignment *found;
 } attr_get_many_info;

 int git_attr_get_many_with_session(
 	const char **values,
 	git_repository *repo,
 	git_attr_session *attr_session,
 	uint32_t flags,
 	const char *pathname,
 	size_t num_attr,
 	const char **names)
 {
 	int error;
 	git_attr_path path;
 	git_vector files = GIT_VECTOR_INIT;
 	size_t i, j, k;
 	git_attr_file *file;
 	git_attr_rule *rule;
 	attr_get_many_info *info = NULL;
 	size_t num_found = 0;
 	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;

 	if (!num_attr)
 		return 0;

 	assert(values && repo && names);

 	if (git_repository_is_bare(repo))
 		dir_flag = GIT_DIR_FLAG_FALSE;

 	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
 		return -1;

 	if ((error = collect_attr_files(repo, attr_session, flags, pathname, &files)) < 0)
 		goto cleanup;

 	info = git__calloc(num_attr, sizeof(attr_get_many_info));
 	GIT_ERROR_CHECK_ALLOC(info);

 	git_vector_foreach(&files, i, file) {

 		git_attr_file__foreach_matching_rule(file, &path, j, rule) {

 			for (k = 0; k < num_attr; k++) {
 				size_t pos;

 				if (info[k].found != NULL) /* already found assignment */
 					continue;

 				if (!info[k].name.name) {
 					info[k].name.name = names[k];
 					info[k].name.name_hash = git_attr_file__name_hash(names[k]);
 				}

 				if (!git_vector_bsearch(&pos, &rule->assigns, &info[k].name)) {
 					info[k].found = (git_attr_assignment *)
 						git_vector_get(&rule->assigns, pos);
 					values[k] = info[k].found->value;

 					if (++num_found == num_attr)
 						goto cleanup;
 				}
 			}
 		}
 	}

 	for (k = 0; k < num_attr; k++) {
 		if (!info[k].found)
 			values[k] = NULL;
 	}

 cleanup:
 	release_attr_files(&files);
 	git_attr_path__free(&path);
 	git__free(info);

 	return error;
 }

 int git_attr_get_many(
 	const char **values,
 	git_repository *repo,
 	uint32_t flags,
 	const char *pathname,
 	size_t num_attr,
 	const char **names)
 {
 	return git_attr_get_many_with_session(
 		values, repo, NULL, flags, pathname, num_attr, names);
 }

 int git_attr_foreach(
 	git_repository *repo,
 	uint32_t flags,
 	const char *pathname,
 	int (*callback)(const char *name, const char *value, void *payload),
 	void *payload)
 {
 	int error;
 	git_attr_path path;
 	git_vector files = GIT_VECTOR_INIT;
 	size_t i, j, k;
 	git_attr_file *file;
 	git_attr_rule *rule;
 	git_attr_assignment *assign;
 	git_strmap *seen = NULL;
 	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;

 	assert(repo && callback);

 	if (git_repository_is_bare(repo))
 		dir_flag = GIT_DIR_FLAG_FALSE;

 	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
 		return -1;

 	if ((error = collect_attr_files(repo, NULL, flags, pathname, &files)) < 0 ||
 		(error = git_strmap_alloc(&seen)) < 0)
 		goto cleanup;

 	git_vector_foreach(&files, i, file) {

 		git_attr_file__foreach_matching_rule(file, &path, j, rule) {

 			git_vector_foreach(&rule->assigns, k, assign) {
 				/* skip if higher priority assignment was already seen */
 				if (git_strmap_exists(seen, assign->name))
 					continue;

 				git_strmap_insert(seen, assign->name, assign, &error);
 				if (error < 0)
 					goto cleanup;

 				error = callback(assign->name, assign->value, payload);
 				if (error) {
 					git_error_set_after_callback(error);
 					goto cleanup;
 				}
 			}
 		}
 	}

 cleanup:
 	git_strmap_free(seen);
 	release_attr_files(&files);
 	git_attr_path__free(&path);

 	return error;
 }

 static int preload_attr_file(
 	git_repository *repo,
 	git_attr_session *attr_session,
 	git_attr_file_source source,
 	const char *base,
 	const char *file)
 {
 	int error;
 	git_attr_file *preload = NULL;

 	if (!file)
 		return 0;
 	if (!(error = git_attr_cache__get(
 			&preload, repo, attr_session, source, base, file, git_attr_file__parse_buffer)))
 		git_attr_file__free(preload);

 	return error;
 }

 static int system_attr_file(
 	git_buf *out,
 	git_attr_session *attr_session)
 {
 	int error;

 	if (!attr_session) {
 		error = git_sysdir_find_system_file(out, GIT_ATTR_FILE_SYSTEM);

 		if (error == GIT_ENOTFOUND)
 			git_error_clear();

 		return error;
 	}

 	if (!attr_session->init_sysdir) {
 		error = git_sysdir_find_system_file(&attr_session->sysdir, GIT_ATTR_FILE_SYSTEM);

 		if (error == GIT_ENOTFOUND)
 			git_error_clear();
 		else if (error)
 			return error;

 		attr_session->init_sysdir = 1;
 	}

 	if (attr_session->sysdir.size == 0)
 		return GIT_ENOTFOUND;

 	/* We can safely provide a git_buf with no allocation (asize == 0) to
 	 * a consumer. This allows them to treat this as a regular `git_buf`,
 	 * but their call to `git_buf_dispose` will not attempt to free it.
 	 */
 	git_buf_attach_notowned(
 		out, attr_session->sysdir.ptr, attr_session->sysdir.size);
 	return 0;
 }

 static int attr_setup(git_repository *repo, git_attr_session *attr_session)
 {
 	int error = 0;
 	const char *workdir = git_repository_workdir(repo);
 	git_index *idx = NULL;
 	git_buf path = GIT_BUF_INIT;

 	if (attr_session && attr_session->init_setup)
 		return 0;

 	if ((error = git_attr_cache__init(repo)) < 0)
 		return error;

 	/* preload attribute files that could contain macros so the
 	 * definitions will be available for later file parsing
 	 */

 	error = system_attr_file(&path, attr_session);

 	if (error == 0)
 		error = preload_attr_file(
 			repo, attr_session, GIT_ATTR_FILE__FROM_FILE, NULL, path.ptr);

 	if (error != GIT_ENOTFOUND)
 		goto out;

 	if ((error = preload_attr_file(
 			repo, attr_session, GIT_ATTR_FILE__FROM_FILE,
 			NULL, git_repository_attr_cache(repo)->cfg_attr_file)) < 0)
 		goto out;

 	if ((error = git_repository_item_path(&path,
 			repo, GIT_REPOSITORY_ITEM_INFO)) < 0)
 		goto out;

 	if ((error = preload_attr_file(
 			repo, attr_session, GIT_ATTR_FILE__FROM_FILE,
 			path.ptr, GIT_ATTR_FILE_INREPO)) < 0)
 		goto out;

 	if (workdir != NULL &&
 		(error = preload_attr_file(
 			repo, attr_session, GIT_ATTR_FILE__FROM_FILE, workdir, GIT_ATTR_FILE)) < 0)
 		goto out;

 	if ((error = git_repository_index__weakptr(&idx, repo)) < 0 ||
 		(error = preload_attr_file(
 			repo, attr_session, GIT_ATTR_FILE__FROM_INDEX, NULL, GIT_ATTR_FILE)) < 0)
 		goto out;

 	if (attr_session)
 		attr_session->init_setup = 1;

 out:
 	git_buf_dispose(&path);

 	return error;
 }

 int git_attr_add_macro(
 	git_repository *repo,
 	const char *name,
 	const char *values)
 {
 	int error;
 	git_attr_rule *macro = NULL;
 	git_pool *pool;

 	if ((error = git_attr_cache__init(repo)) < 0)
 		return error;

 	macro = git__calloc(1, sizeof(git_attr_rule));
 	GIT_ERROR_CHECK_ALLOC(macro);

 	pool = &git_repository_attr_cache(repo)->pool;

 	macro->match.pattern = git_pool_strdup(pool, name);
 	GIT_ERROR_CHECK_ALLOC(macro->match.pattern);

 	macro->match.length = strlen(macro->match.pattern);
 	macro->match.flags = GIT_ATTR_FNMATCH_MACRO;

 	error = git_attr_assignment__parse(repo, pool, &macro->assigns, &values);

 	if (!error)
 		error = git_attr_cache__insert_macro(repo, macro);

 	if (error < 0)
 		git_attr_rule__free(macro);

 	return error;
 }

 typedef struct {
 	git_repository *repo;
 	git_attr_session *attr_session;
 	uint32_t flags;
 	const char *workdir;
 	git_index *index;
 	git_vector *files;
 } attr_walk_up_info;

 static int attr_decide_sources(
 	uint32_t flags, bool has_wd, bool has_index, git_attr_file_source *srcs)
 {
 	int count = 0;

 	switch (flags & 0x03) {
 	case GIT_ATTR_CHECK_FILE_THEN_INDEX:
 		if (has_wd)
 			srcs[count++] = GIT_ATTR_FILE__FROM_FILE;
 		if (has_index)
 			srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
 		break;
 	case GIT_ATTR_CHECK_INDEX_THEN_FILE:
 		if (has_index)
 			srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
 		if (has_wd)
 			srcs[count++] = GIT_ATTR_FILE__FROM_FILE;
 		break;
 	case GIT_ATTR_CHECK_INDEX_ONLY:
 		if (has_index)
 			srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
 		break;
 	}

 	return count;
 }

 static int push_attr_file(
 	git_repository *repo,
 	git_attr_session *attr_session,
 	git_vector *list,
 	git_attr_file_source source,
 	const char *base,
 	const char *filename)
 {
 	int error = 0;
 	git_attr_file *file = NULL;

 	error = git_attr_cache__get(&file, repo, attr_session,
 		source, base, filename, git_attr_file__parse_buffer);

 	if (error < 0)
 		return error;

 	if (file != NULL) {
 		if ((error = git_vector_insert(list, file)) < 0)
 			git_attr_file__free(file);
 	}

 	return error;
 }

 static int push_one_attr(void *ref, const char *path)
 {
 	int error = 0, n_src, i;
 	attr_walk_up_info *info = (attr_walk_up_info *)ref;
 	git_attr_file_source src[2];

 	n_src = attr_decide_sources(
 		info->flags, info->workdir != NULL, info->index != NULL, src);

 	for (i = 0; !error && i < n_src; ++i)
 		error = push_attr_file(info->repo, info->attr_session,
 			info->files, src[i], path, GIT_ATTR_FILE);

 	return error;
 }

 static void release_attr_files(git_vector *files)
 {
 	size_t i;
 	git_attr_file *file;

 	git_vector_foreach(files, i, file) {
 		git_attr_file__free(file);
 		files->contents[i] = NULL;
 	}
 	git_vector_free(files);
 }

 static int collect_attr_files(
 	git_repository *repo,
 	git_attr_session *attr_session,
 	uint32_t flags,
 	const char *path,
 	git_vector *files)
 {
 	int error = 0;
 	git_buf dir = GIT_BUF_INIT, attrfile = GIT_BUF_INIT;
 	const char *workdir = git_repository_workdir(repo);
 	attr_walk_up_info info = { NULL };

 	if ((error = attr_setup(repo, attr_session)) < 0)
 		return error;

 	/* Resolve path in a non-bare repo */
 	if (workdir != NULL)
 		error = git_path_find_dir(&dir, path, workdir);
 	else
 		error = git_path_dirname_r(&dir, path);
 	if (error < 0)
 		goto cleanup;

 	/* in precendence order highest to lowest:
 	 * - $GIT_DIR/info/attributes
 	 * - path components with .gitattributes
 	 * - config core.attributesfile
 	 * - $GIT_PREFIX/etc/gitattributes
 	 */

 	error = git_repository_item_path(&attrfile, repo, GIT_REPOSITORY_ITEM_INFO);
 	if (error < 0)
 		goto cleanup;

 	error = push_attr_file(
 		repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
 		attrfile.ptr, GIT_ATTR_FILE_INREPO);
 	if (error < 0)
 		goto cleanup;

 	info.repo = repo;
 	info.attr_session = attr_session;
 	info.flags = flags;
 	info.workdir = workdir;
 	if (git_repository_index__weakptr(&info.index, repo) < 0)
 		git_error_clear(); /* no error even if there is no index */
 	info.files = files;

 	if (!strcmp(dir.ptr, "."))
 		error = push_one_attr(&info, "");
 	else
 		error = git_path_walk_up(&dir, workdir, push_one_attr, &info);

 	if (error < 0)
 		goto cleanup;

 	if (git_repository_attr_cache(repo)->cfg_attr_file != NULL) {
 		error = push_attr_file(
 			repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
 			NULL, git_repository_attr_cache(repo)->cfg_attr_file);
 		if (error < 0)
 			goto cleanup;
 	}

 	if ((flags & GIT_ATTR_CHECK_NO_SYSTEM) == 0) {
 		error = system_attr_file(&dir, attr_session);

 		if (!error)
 			error = push_attr_file(
 				repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
 				NULL, dir.ptr);
 		else if (error == GIT_ENOTFOUND)
 			error = 0;
 	}

  cleanup:
 	if (error < 0)
 		release_attr_files(files);
 	git_buf_dispose(&attrfile);
 	git_buf_dispose(&dir);

 	return error;
 }
	/*
	* 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 "attr.h"

	#include "repository.h"
	#include "sysdir.h"
	#include "config.h"
	#include "attr_file.h"
	#include "ignore.h"
	#include "git2/oid.h"
	#include <ctype.h>

	const char *git_attr__true = "[internal]__TRUE__";
	const char *git_attr__false = "[internal]__FALSE__";
	const char *git_attr__unset = "[internal]__UNSET__";

	git_attr_t git_attr_value(const char *attr)
	{
	if (attr == NULL \|\| attr == git_attr__unset)
	return GIT_ATTR_UNSPECIFIED_T;

	if (attr == git_attr__true)
	return GIT_ATTR_TRUE_T;

	if (attr == git_attr__false)
	return GIT_ATTR_FALSE_T;

	return GIT_ATTR_VALUE_T;
	}

	static int collect_attr_files(
	git_repository *repo,
	git_attr_session *attr_session,
	uint32_t flags,
	const char *path,
	git_vector *files);

	static void release_attr_files(git_vector *files);

	int git_attr_get(
	const char **value,
	git_repository *repo,
	uint32_t flags,
	const char *pathname,
	const char *name)
	{
	int error;
	git_attr_path path;
	git_vector files = GIT_VECTOR_INIT;
	size_t i, j;
	git_attr_file *file;
	git_attr_name attr;
	git_attr_rule *rule;
	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;

	assert(value && repo && name);

	*value = NULL;

	if (git_repository_is_bare(repo))
	dir_flag = GIT_DIR_FLAG_FALSE;

	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
	return -1;

	if ((error = collect_attr_files(repo, NULL, flags, pathname, &files)) < 0)
	goto cleanup;

	memset(&attr, 0, sizeof(attr));
	attr.name = name;
	attr.name_hash = git_attr_file__name_hash(name);

	git_vector_foreach(&files, i, file) {

	git_attr_file__foreach_matching_rule(file, &path, j, rule) {
	size_t pos;

	if (!git_vector_bsearch(&pos, &rule->assigns, &attr)) {
	value = ((git_attr_assignment )git_vector_get(
	&rule->assigns, pos))->value;
	goto cleanup;
	}
	}
	}

	cleanup:
	release_attr_files(&files);
	git_attr_path__free(&path);

	return error;
	}


	typedef struct {
	git_attr_name name;
	git_attr_assignment *found;
	} attr_get_many_info;

	int git_attr_get_many_with_session(
	const char **values,
	git_repository *repo,
	git_attr_session *attr_session,
	uint32_t flags,
	const char *pathname,
	size_t num_attr,
	const char **names)
	{
	int error;
	git_attr_path path;
	git_vector files = GIT_VECTOR_INIT;
	size_t i, j, k;
	git_attr_file *file;
	git_attr_rule *rule;
	attr_get_many_info *info = NULL;
	size_t num_found = 0;
	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;

	if (!num_attr)
	return 0;

	assert(values && repo && names);

	if (git_repository_is_bare(repo))
	dir_flag = GIT_DIR_FLAG_FALSE;

	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
	return -1;

	if ((error = collect_attr_files(repo, attr_session, flags, pathname, &files)) < 0)
	goto cleanup;

	info = git__calloc(num_attr, sizeof(attr_get_many_info));
	GIT_ERROR_CHECK_ALLOC(info);

	git_vector_foreach(&files, i, file) {

	git_attr_file__foreach_matching_rule(file, &path, j, rule) {

	for (k = 0; k < num_attr; k++) {
	size_t pos;

	if (info[k].found != NULL) /* already found assignment */
	continue;

	if (!info[k].name.name) {
	info[k].name.name = names[k];
	info[k].name.name_hash = git_attr_file__name_hash(names[k]);
	}

	if (!git_vector_bsearch(&pos, &rule->assigns, &info[k].name)) {
	info[k].found = (git_attr_assignment *)
	git_vector_get(&rule->assigns, pos);
	values[k] = info[k].found->value;

	if (++num_found == num_attr)
	goto cleanup;
	}
	}
	}
	}

	for (k = 0; k < num_attr; k++) {
	if (!info[k].found)
	values[k] = NULL;
	}

	cleanup:
	release_attr_files(&files);
	git_attr_path__free(&path);
	git__free(info);

	return error;
	}

	int git_attr_get_many(
	const char **values,
	git_repository *repo,
	uint32_t flags,
	const char *pathname,
	size_t num_attr,
	const char **names)
	{
	return git_attr_get_many_with_session(
	values, repo, NULL, flags, pathname, num_attr, names);
	}

	int git_attr_foreach(
	git_repository *repo,
	uint32_t flags,
	const char *pathname,
	int (callback)(const char name, const char value, void payload),
	void *payload)
	{
	int error;
	git_attr_path path;
	git_vector files = GIT_VECTOR_INIT;
	size_t i, j, k;
	git_attr_file *file;
	git_attr_rule *rule;
	git_attr_assignment *assign;
	git_strmap *seen = NULL;
	git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;

	assert(repo && callback);

	if (git_repository_is_bare(repo))
	dir_flag = GIT_DIR_FLAG_FALSE;

	if (git_attr_path__init(&path, pathname, git_repository_workdir(repo), dir_flag) < 0)
	return -1;

	if ((error = collect_attr_files(repo, NULL, flags, pathname, &files)) < 0 \|\|
	(error = git_strmap_alloc(&seen)) < 0)
	goto cleanup;

	git_vector_foreach(&files, i, file) {

	git_attr_file__foreach_matching_rule(file, &path, j, rule) {

	git_vector_foreach(&rule->assigns, k, assign) {
	/* skip if higher priority assignment was already seen */
	if (git_strmap_exists(seen, assign->name))
	continue;

	git_strmap_insert(seen, assign->name, assign, &error);
	if (error < 0)
	goto cleanup;

	error = callback(assign->name, assign->value, payload);
	if (error) {
	git_error_set_after_callback(error);
	goto cleanup;
	}
	}
	}
	}

	cleanup:
	git_strmap_free(seen);
	release_attr_files(&files);
	git_attr_path__free(&path);

	return error;
	}

	static int preload_attr_file(
	git_repository *repo,
	git_attr_session *attr_session,
	git_attr_file_source source,
	const char *base,
	const char *file)
	{
	int error;
	git_attr_file *preload = NULL;

	if (!file)
	return 0;
	if (!(error = git_attr_cache__get(
	&preload, repo, attr_session, source, base, file, git_attr_file__parse_buffer)))
	git_attr_file__free(preload);

	return error;
	}

	static int system_attr_file(
	git_buf *out,
	git_attr_session *attr_session)
	{
	int error;

	if (!attr_session) {
	error = git_sysdir_find_system_file(out, GIT_ATTR_FILE_SYSTEM);

	if (error == GIT_ENOTFOUND)
	git_error_clear();

	return error;
	}

	if (!attr_session->init_sysdir) {
	error = git_sysdir_find_system_file(&attr_session->sysdir, GIT_ATTR_FILE_SYSTEM);

	if (error == GIT_ENOTFOUND)
	git_error_clear();
	else if (error)
	return error;

	attr_session->init_sysdir = 1;
	}

	if (attr_session->sysdir.size == 0)
	return GIT_ENOTFOUND;

	/* We can safely provide a git_buf with no allocation (asize == 0) to
	* a consumer. This allows them to treat this as a regular `git_buf`,
	* but their call to `git_buf_dispose` will not attempt to free it.
	*/
	git_buf_attach_notowned(
	out, attr_session->sysdir.ptr, attr_session->sysdir.size);
	return 0;
	}

	static int attr_setup(git_repository repo, git_attr_session attr_session)
	{
	int error = 0;
	const char *workdir = git_repository_workdir(repo);
	git_index *idx = NULL;
	git_buf path = GIT_BUF_INIT;

	if (attr_session && attr_session->init_setup)
	return 0;

	if ((error = git_attr_cache__init(repo)) < 0)
	return error;

	/* preload attribute files that could contain macros so the
	* definitions will be available for later file parsing
	*/

	error = system_attr_file(&path, attr_session);

	if (error == 0)
	error = preload_attr_file(
	repo, attr_session, GIT_ATTR_FILE__FROM_FILE, NULL, path.ptr);

	if (error != GIT_ENOTFOUND)
	goto out;

	if ((error = preload_attr_file(
	repo, attr_session, GIT_ATTR_FILE__FROM_FILE,
	NULL, git_repository_attr_cache(repo)->cfg_attr_file)) < 0)
	goto out;

	if ((error = git_repository_item_path(&path,
	repo, GIT_REPOSITORY_ITEM_INFO)) < 0)
	goto out;

	if ((error = preload_attr_file(
	repo, attr_session, GIT_ATTR_FILE__FROM_FILE,
	path.ptr, GIT_ATTR_FILE_INREPO)) < 0)
	goto out;

	if (workdir != NULL &&
	(error = preload_attr_file(
	repo, attr_session, GIT_ATTR_FILE__FROM_FILE, workdir, GIT_ATTR_FILE)) < 0)
	goto out;

	if ((error = git_repository_index__weakptr(&idx, repo)) < 0 \|\|
	(error = preload_attr_file(
	repo, attr_session, GIT_ATTR_FILE__FROM_INDEX, NULL, GIT_ATTR_FILE)) < 0)
	goto out;

	if (attr_session)
	attr_session->init_setup = 1;

	out:
	git_buf_dispose(&path);

	return error;
	}

	int git_attr_add_macro(
	git_repository *repo,
	const char *name,
	const char *values)
	{
	int error;
	git_attr_rule *macro = NULL;
	git_pool *pool;

	if ((error = git_attr_cache__init(repo)) < 0)
	return error;

	macro = git__calloc(1, sizeof(git_attr_rule));
	GIT_ERROR_CHECK_ALLOC(macro);

	pool = &git_repository_attr_cache(repo)->pool;

	macro->match.pattern = git_pool_strdup(pool, name);
	GIT_ERROR_CHECK_ALLOC(macro->match.pattern);

	macro->match.length = strlen(macro->match.pattern);
	macro->match.flags = GIT_ATTR_FNMATCH_MACRO;

	error = git_attr_assignment__parse(repo, pool, &macro->assigns, &values);

	if (!error)
	error = git_attr_cache__insert_macro(repo, macro);

	if (error < 0)
	git_attr_rule__free(macro);

	return error;
	}

	typedef struct {
	git_repository *repo;
	git_attr_session *attr_session;
	uint32_t flags;
	const char *workdir;
	git_index *index;
	git_vector *files;
	} attr_walk_up_info;

	static int attr_decide_sources(
	uint32_t flags, bool has_wd, bool has_index, git_attr_file_source *srcs)
	{
	int count = 0;

	switch (flags & 0x03) {
	case GIT_ATTR_CHECK_FILE_THEN_INDEX:
	if (has_wd)
	srcs[count++] = GIT_ATTR_FILE__FROM_FILE;
	if (has_index)
	srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
	break;
	case GIT_ATTR_CHECK_INDEX_THEN_FILE:
	if (has_index)
	srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
	if (has_wd)
	srcs[count++] = GIT_ATTR_FILE__FROM_FILE;
	break;
	case GIT_ATTR_CHECK_INDEX_ONLY:
	if (has_index)
	srcs[count++] = GIT_ATTR_FILE__FROM_INDEX;
	break;
	}

	return count;
	}

	static int push_attr_file(
	git_repository *repo,
	git_attr_session *attr_session,
	git_vector *list,
	git_attr_file_source source,
	const char *base,
	const char *filename)
	{
	int error = 0;
	git_attr_file *file = NULL;

	error = git_attr_cache__get(&file, repo, attr_session,
	source, base, filename, git_attr_file__parse_buffer);

	if (error < 0)
	return error;

	if (file != NULL) {
	if ((error = git_vector_insert(list, file)) < 0)
	git_attr_file__free(file);
	}

	return error;
	}

	static int push_one_attr(void ref, const char path)
	{
	int error = 0, n_src, i;
	attr_walk_up_info info = (attr_walk_up_info )ref;
	git_attr_file_source src[2];

	n_src = attr_decide_sources(
	info->flags, info->workdir != NULL, info->index != NULL, src);

	for (i = 0; !error && i < n_src; ++i)
	error = push_attr_file(info->repo, info->attr_session,
	info->files, src[i], path, GIT_ATTR_FILE);

	return error;
	}

	static void release_attr_files(git_vector *files)
	{
	size_t i;
	git_attr_file *file;

	git_vector_foreach(files, i, file) {
	git_attr_file__free(file);
	files->contents[i] = NULL;
	}
	git_vector_free(files);
	}

	static int collect_attr_files(
	git_repository *repo,
	git_attr_session *attr_session,
	uint32_t flags,
	const char *path,
	git_vector *files)
	{
	int error = 0;
	git_buf dir = GIT_BUF_INIT, attrfile = GIT_BUF_INIT;
	const char *workdir = git_repository_workdir(repo);
	attr_walk_up_info info = { NULL };

	if ((error = attr_setup(repo, attr_session)) < 0)
	return error;

	/* Resolve path in a non-bare repo */
	if (workdir != NULL)
	error = git_path_find_dir(&dir, path, workdir);
	else
	error = git_path_dirname_r(&dir, path);
	if (error < 0)
	goto cleanup;

	/* in precendence order highest to lowest:
	* - $GIT_DIR/info/attributes
	* - path components with .gitattributes
	* - config core.attributesfile
	* - $GIT_PREFIX/etc/gitattributes
	*/

	error = git_repository_item_path(&attrfile, repo, GIT_REPOSITORY_ITEM_INFO);
	if (error < 0)
	goto cleanup;

	error = push_attr_file(
	repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
	attrfile.ptr, GIT_ATTR_FILE_INREPO);
	if (error < 0)
	goto cleanup;

	info.repo = repo;
	info.attr_session = attr_session;
	info.flags = flags;
	info.workdir = workdir;
	if (git_repository_index__weakptr(&info.index, repo) < 0)
	git_error_clear(); /* no error even if there is no index */
	info.files = files;

	if (!strcmp(dir.ptr, "."))
	error = push_one_attr(&info, "");
	else
	error = git_path_walk_up(&dir, workdir, push_one_attr, &info);

	if (error < 0)
	goto cleanup;

	if (git_repository_attr_cache(repo)->cfg_attr_file != NULL) {
	error = push_attr_file(
	repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
	NULL, git_repository_attr_cache(repo)->cfg_attr_file);
	if (error < 0)
	goto cleanup;
	}

	if ((flags & GIT_ATTR_CHECK_NO_SYSTEM) == 0) {
	error = system_attr_file(&dir, attr_session);

	if (!error)
	error = push_attr_file(
	repo, attr_session, files, GIT_ATTR_FILE__FROM_FILE,
	NULL, dir.ptr);
	else if (error == GIT_ENOTFOUND)
	error = 0;
	}

	cleanup:
	if (error < 0)
	release_attr_files(files);
	git_buf_dispose(&attrfile);
	git_buf_dispose(&dir);

	return error;
	}