git/archive.c
Karthik Nayak 47cfc9bd7d attr: add flag --source to work with tree-ish
The contents of the .gitattributes files may evolve over time, but "git
check-attr" always checks attributes against them in the working tree
and/or in the index. It may be beneficial to optionally allow the users
to check attributes taken from a commit other than HEAD against paths.

Add a new flag `--source` which will allow users to check the
attributes against a commit (actually any tree-ish would do). When the
user uses this flag, we go through the stack of .gitattributes files but
instead of checking the current working tree and/or in the index, we
check the blobs from the provided tree-ish object. This allows the
command to also be used in bare repositories.

Since we use a tree-ish object, the user can pass "--source
HEAD:subdirectory" and all the attributes will be looked up as if
subdirectory was the root directory of the repository.

We cannot simply use the `<rev>:<path>` syntax without the `--source`
flag, similar to how it is used in `git show` because any non-flag
parameter before `--` is treated as an attribute and any parameter after
`--` is treated as a pathname.

The change involves creating a new function `read_attr_from_blob`, which
given the path reads the blob for the path against the provided source and
parses the attributes line by line. This function is plugged into
`read_attr()` function wherein we go through the stack of attributes
files.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Toon Claes <toon@iotcl.com>
Co-authored-by: toon@iotcl.com
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-14 08:49:55 -08:00

740 lines
19 KiB
C

#include "cache.h"
#include "config.h"
#include "refs.h"
#include "object-store.h"
#include "commit.h"
#include "tree-walk.h"
#include "attr.h"
#include "archive.h"
#include "parse-options.h"
#include "unpack-trees.h"
#include "dir.h"
#include "quote.h"
static char const * const archive_usage[] = {
N_("git archive [<options>] <tree-ish> [<path>...]"),
"git archive --list",
N_("git archive --remote <repo> [--exec <cmd>] [<options>] <tree-ish> [<path>...]"),
N_("git archive --remote <repo> [--exec <cmd>] --list"),
NULL
};
static const struct archiver **archivers;
static int nr_archivers;
static int alloc_archivers;
static int remote_allow_unreachable;
void register_archiver(struct archiver *ar)
{
ALLOC_GROW(archivers, nr_archivers + 1, alloc_archivers);
archivers[nr_archivers++] = ar;
}
void init_archivers(void)
{
init_tar_archiver();
init_zip_archiver();
}
static void format_subst(const struct commit *commit,
const char *src, size_t len,
struct strbuf *buf, struct pretty_print_context *ctx)
{
char *to_free = NULL;
struct strbuf fmt = STRBUF_INIT;
if (src == buf->buf)
to_free = strbuf_detach(buf, NULL);
for (;;) {
const char *b, *c;
b = memmem(src, len, "$Format:", 8);
if (!b)
break;
c = memchr(b + 8, '$', (src + len) - b - 8);
if (!c)
break;
strbuf_reset(&fmt);
strbuf_add(&fmt, b + 8, c - b - 8);
strbuf_add(buf, src, b - src);
format_commit_message(commit, fmt.buf, buf, ctx);
len -= c + 1 - src;
src = c + 1;
}
strbuf_add(buf, src, len);
strbuf_release(&fmt);
free(to_free);
}
static void *object_file_to_archive(const struct archiver_args *args,
const char *path,
const struct object_id *oid,
unsigned int mode,
enum object_type *type,
unsigned long *sizep)
{
void *buffer;
const struct commit *commit = args->convert ? args->commit : NULL;
struct checkout_metadata meta;
init_checkout_metadata(&meta, args->refname,
args->commit_oid ? args->commit_oid :
(args->tree ? &args->tree->object.oid : NULL), oid);
path += args->baselen;
buffer = read_object_file(oid, type, sizep);
if (buffer && S_ISREG(mode)) {
struct strbuf buf = STRBUF_INIT;
size_t size = 0;
strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
convert_to_working_tree(args->repo->index, path, buf.buf, buf.len, &buf, &meta);
if (commit)
format_subst(commit, buf.buf, buf.len, &buf, args->pretty_ctx);
buffer = strbuf_detach(&buf, &size);
*sizep = size;
}
return buffer;
}
struct directory {
struct directory *up;
struct object_id oid;
int baselen, len;
unsigned mode;
char path[FLEX_ARRAY];
};
struct archiver_context {
struct archiver_args *args;
write_archive_entry_fn_t write_entry;
struct directory *bottom;
};
static const struct attr_check *get_archive_attrs(struct index_state *istate,
const char *path)
{
static struct attr_check *check;
if (!check)
check = attr_check_initl("export-ignore", "export-subst", NULL);
git_check_attr(istate, NULL, path, check);
return check;
}
static int check_attr_export_ignore(const struct attr_check *check)
{
return check && ATTR_TRUE(check->items[0].value);
}
static int check_attr_export_subst(const struct attr_check *check)
{
return check && ATTR_TRUE(check->items[1].value);
}
static int write_archive_entry(const struct object_id *oid, const char *base,
int baselen, const char *filename, unsigned mode,
void *context)
{
static struct strbuf path = STRBUF_INIT;
struct archiver_context *c = context;
struct archiver_args *args = c->args;
write_archive_entry_fn_t write_entry = c->write_entry;
int err;
const char *path_without_prefix;
unsigned long size;
void *buffer;
enum object_type type;
args->convert = 0;
strbuf_reset(&path);
strbuf_grow(&path, PATH_MAX);
strbuf_add(&path, args->base, args->baselen);
strbuf_add(&path, base, baselen);
strbuf_addstr(&path, filename);
if (S_ISDIR(mode) || S_ISGITLINK(mode))
strbuf_addch(&path, '/');
path_without_prefix = path.buf + args->baselen;
if (!S_ISDIR(mode)) {
const struct attr_check *check;
check = get_archive_attrs(args->repo->index, path_without_prefix);
if (check_attr_export_ignore(check))
return 0;
args->convert = check_attr_export_subst(check);
}
if (args->verbose)
fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
err = write_entry(args, oid, path.buf, path.len, mode, NULL, 0);
if (err)
return err;
return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
}
/* Stream it? */
if (S_ISREG(mode) && !args->convert &&
oid_object_info(args->repo, oid, &size) == OBJ_BLOB &&
size > big_file_threshold)
return write_entry(args, oid, path.buf, path.len, mode, NULL, size);
buffer = object_file_to_archive(args, path.buf, oid, mode, &type, &size);
if (!buffer)
return error(_("cannot read '%s'"), oid_to_hex(oid));
err = write_entry(args, oid, path.buf, path.len, mode, buffer, size);
free(buffer);
return err;
}
static void queue_directory(const struct object_id *oid,
struct strbuf *base, const char *filename,
unsigned mode, struct archiver_context *c)
{
struct directory *d;
size_t len = st_add4(base->len, 1, strlen(filename), 1);
d = xmalloc(st_add(sizeof(*d), len));
d->up = c->bottom;
d->baselen = base->len;
d->mode = mode;
c->bottom = d;
d->len = xsnprintf(d->path, len, "%.*s%s/", (int)base->len, base->buf, filename);
oidcpy(&d->oid, oid);
}
static int write_directory(struct archiver_context *c)
{
struct directory *d = c->bottom;
int ret;
if (!d)
return 0;
c->bottom = d->up;
d->path[d->len - 1] = '\0'; /* no trailing slash */
ret =
write_directory(c) ||
write_archive_entry(&d->oid, d->path, d->baselen,
d->path + d->baselen, d->mode,
c) != READ_TREE_RECURSIVE;
free(d);
return ret ? -1 : 0;
}
static int queue_or_write_archive_entry(const struct object_id *oid,
struct strbuf *base, const char *filename,
unsigned mode, void *context)
{
struct archiver_context *c = context;
while (c->bottom &&
!(base->len >= c->bottom->len &&
!strncmp(base->buf, c->bottom->path, c->bottom->len))) {
struct directory *next = c->bottom->up;
free(c->bottom);
c->bottom = next;
}
if (S_ISDIR(mode)) {
size_t baselen = base->len;
const struct attr_check *check;
/* Borrow base, but restore its original value when done. */
strbuf_addstr(base, filename);
strbuf_addch(base, '/');
check = get_archive_attrs(c->args->repo->index, base->buf);
strbuf_setlen(base, baselen);
if (check_attr_export_ignore(check))
return 0;
queue_directory(oid, base, filename, mode, c);
return READ_TREE_RECURSIVE;
}
if (write_directory(c))
return -1;
return write_archive_entry(oid, base->buf, base->len, filename, mode,
context);
}
struct extra_file_info {
char *base;
struct stat stat;
void *content;
};
int write_archive_entries(struct archiver_args *args,
write_archive_entry_fn_t write_entry)
{
struct archiver_context context;
struct unpack_trees_options opts;
struct tree_desc t;
int err;
struct strbuf path_in_archive = STRBUF_INIT;
struct strbuf content = STRBUF_INIT;
struct object_id fake_oid;
int i;
oidcpy(&fake_oid, null_oid());
if (args->baselen > 0 && args->base[args->baselen - 1] == '/') {
size_t len = args->baselen;
while (len > 1 && args->base[len - 2] == '/')
len--;
if (args->verbose)
fprintf(stderr, "%.*s\n", (int)len, args->base);
err = write_entry(args, &args->tree->object.oid, args->base,
len, 040777, NULL, 0);
if (err)
return err;
}
memset(&context, 0, sizeof(context));
context.args = args;
context.write_entry = write_entry;
/*
* Setup index and instruct attr to read index only
*/
if (!args->worktree_attributes) {
memset(&opts, 0, sizeof(opts));
opts.index_only = 1;
opts.head_idx = -1;
opts.src_index = args->repo->index;
opts.dst_index = args->repo->index;
opts.fn = oneway_merge;
init_tree_desc(&t, args->tree->buffer, args->tree->size);
if (unpack_trees(1, &t, &opts))
return -1;
git_attr_set_direction(GIT_ATTR_INDEX);
}
err = read_tree(args->repo, args->tree,
&args->pathspec,
queue_or_write_archive_entry,
&context);
if (err == READ_TREE_RECURSIVE)
err = 0;
while (context.bottom) {
struct directory *next = context.bottom->up;
free(context.bottom);
context.bottom = next;
}
for (i = 0; i < args->extra_files.nr; i++) {
struct string_list_item *item = args->extra_files.items + i;
char *path = item->string;
struct extra_file_info *info = item->util;
put_be64(fake_oid.hash, i + 1);
if (!info->content) {
strbuf_reset(&path_in_archive);
if (info->base)
strbuf_addstr(&path_in_archive, info->base);
strbuf_addstr(&path_in_archive, basename(path));
strbuf_reset(&content);
if (strbuf_read_file(&content, path, info->stat.st_size) < 0)
err = error_errno(_("cannot read '%s'"), path);
else
err = write_entry(args, &fake_oid, path_in_archive.buf,
path_in_archive.len,
canon_mode(info->stat.st_mode),
content.buf, content.len);
} else {
err = write_entry(args, &fake_oid,
path, strlen(path),
canon_mode(info->stat.st_mode),
info->content, info->stat.st_size);
}
if (err)
break;
}
strbuf_release(&path_in_archive);
strbuf_release(&content);
return err;
}
static const struct archiver *lookup_archiver(const char *name)
{
int i;
if (!name)
return NULL;
for (i = 0; i < nr_archivers; i++) {
if (!strcmp(name, archivers[i]->name))
return archivers[i];
}
return NULL;
}
struct path_exists_context {
struct pathspec pathspec;
struct archiver_args *args;
};
static int reject_entry(const struct object_id *oid UNUSED,
struct strbuf *base,
const char *filename, unsigned mode,
void *context)
{
int ret = -1;
struct path_exists_context *ctx = context;
if (S_ISDIR(mode)) {
struct strbuf sb = STRBUF_INIT;
strbuf_addbuf(&sb, base);
strbuf_addstr(&sb, filename);
if (!match_pathspec(ctx->args->repo->index,
&ctx->pathspec,
sb.buf, sb.len, 0, NULL, 1))
ret = READ_TREE_RECURSIVE;
strbuf_release(&sb);
}
return ret;
}
static int path_exists(struct archiver_args *args, const char *path)
{
const char *paths[] = { path, NULL };
struct path_exists_context ctx;
int ret;
ctx.args = args;
parse_pathspec(&ctx.pathspec, 0, 0, "", paths);
ctx.pathspec.recursive = 1;
ret = read_tree(args->repo, args->tree,
&ctx.pathspec,
reject_entry, &ctx);
clear_pathspec(&ctx.pathspec);
return ret != 0;
}
static void parse_pathspec_arg(const char **pathspec,
struct archiver_args *ar_args)
{
/*
* must be consistent with parse_pathspec in path_exists()
* Also if pathspec patterns are dependent, we're in big
* trouble as we test each one separately
*/
parse_pathspec(&ar_args->pathspec, 0,
PATHSPEC_PREFER_FULL,
"", pathspec);
ar_args->pathspec.recursive = 1;
if (pathspec) {
while (*pathspec) {
if (**pathspec && !path_exists(ar_args, *pathspec))
die(_("pathspec '%s' did not match any files"), *pathspec);
pathspec++;
}
}
}
static void parse_treeish_arg(const char **argv,
struct archiver_args *ar_args, const char *prefix,
int remote)
{
const char *name = argv[0];
const struct object_id *commit_oid;
time_t archive_time;
struct tree *tree;
const struct commit *commit;
struct object_id oid;
char *ref = NULL;
/* Remotes are only allowed to fetch actual refs */
if (remote && !remote_allow_unreachable) {
const char *colon = strchrnul(name, ':');
int refnamelen = colon - name;
if (!dwim_ref(name, refnamelen, &oid, &ref, 0))
die(_("no such ref: %.*s"), refnamelen, name);
} else {
dwim_ref(name, strlen(name), &oid, &ref, 0);
}
if (get_oid(name, &oid))
die(_("not a valid object name: %s"), name);
commit = lookup_commit_reference_gently(ar_args->repo, &oid, 1);
if (commit) {
commit_oid = &commit->object.oid;
archive_time = commit->date;
} else {
commit_oid = NULL;
archive_time = time(NULL);
}
tree = parse_tree_indirect(&oid);
if (!tree)
die(_("not a tree object: %s"), oid_to_hex(&oid));
if (prefix) {
struct object_id tree_oid;
unsigned short mode;
int err;
err = get_tree_entry(ar_args->repo,
&tree->object.oid,
prefix, &tree_oid,
&mode);
if (err || !S_ISDIR(mode))
die(_("current working directory is untracked"));
tree = parse_tree_indirect(&tree_oid);
}
ar_args->refname = ref;
ar_args->tree = tree;
ar_args->commit_oid = commit_oid;
ar_args->commit = commit;
ar_args->time = archive_time;
}
static void extra_file_info_clear(void *util, const char *str UNUSED)
{
struct extra_file_info *info = util;
free(info->base);
free(info->content);
free(info);
}
static int add_file_cb(const struct option *opt, const char *arg, int unset)
{
struct archiver_args *args = opt->value;
const char **basep = (const char **)opt->defval;
const char *base = *basep;
char *path;
struct string_list_item *item;
struct extra_file_info *info;
if (unset) {
string_list_clear_func(&args->extra_files,
extra_file_info_clear);
return 0;
}
if (!arg)
return -1;
info = xmalloc(sizeof(*info));
info->base = xstrdup_or_null(base);
if (!strcmp(opt->long_name, "add-file")) {
path = prefix_filename(args->prefix, arg);
if (stat(path, &info->stat))
die(_("File not found: %s"), path);
if (!S_ISREG(info->stat.st_mode))
die(_("Not a regular file: %s"), path);
info->content = NULL; /* read the file later */
} else if (!strcmp(opt->long_name, "add-virtual-file")) {
struct strbuf buf = STRBUF_INIT;
const char *p = arg;
if (*p != '"')
p = strchr(p, ':');
else if (unquote_c_style(&buf, p, &p) < 0)
die(_("unclosed quote: '%s'"), arg);
if (!p || *p != ':')
die(_("missing colon: '%s'"), arg);
if (p == arg)
die(_("empty file name: '%s'"), arg);
path = buf.len ?
strbuf_detach(&buf, NULL) : xstrndup(arg, p - arg);
if (args->prefix) {
char *save = path;
path = prefix_filename(args->prefix, path);
free(save);
}
memset(&info->stat, 0, sizeof(info->stat));
info->stat.st_mode = S_IFREG | 0644;
info->content = xstrdup(p + 1);
info->stat.st_size = strlen(info->content);
} else {
BUG("add_file_cb() called for %s", opt->long_name);
}
item = string_list_append_nodup(&args->extra_files, path);
item->util = info;
return 0;
}
static int number_callback(const struct option *opt, const char *arg, int unset)
{
BUG_ON_OPT_NEG(unset);
*(int *)opt->value = strtol(arg, NULL, 10);
return 0;
}
static int parse_archive_args(int argc, const char **argv,
const struct archiver **ar, struct archiver_args *args,
const char *name_hint, int is_remote)
{
const char *format = NULL;
const char *base = NULL;
const char *remote = NULL;
const char *exec = NULL;
const char *output = NULL;
int compression_level = -1;
int verbose = 0;
int i;
int list = 0;
int worktree_attributes = 0;
struct option opts[] = {
OPT_GROUP(""),
OPT_STRING(0, "format", &format, N_("fmt"), N_("archive format")),
OPT_STRING(0, "prefix", &base, N_("prefix"),
N_("prepend prefix to each pathname in the archive")),
{ OPTION_CALLBACK, 0, "add-file", args, N_("file"),
N_("add untracked file to archive"), 0, add_file_cb,
(intptr_t)&base },
{ OPTION_CALLBACK, 0, "add-virtual-file", args,
N_("path:content"), N_("add untracked file to archive"), 0,
add_file_cb, (intptr_t)&base },
OPT_STRING('o', "output", &output, N_("file"),
N_("write the archive to this file")),
OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
N_("read .gitattributes in working directory")),
OPT__VERBOSE(&verbose, N_("report archived files on stderr")),
OPT_NUMBER_CALLBACK(&compression_level,
N_("set compression level"), number_callback),
OPT_GROUP(""),
OPT_BOOL('l', "list", &list,
N_("list supported archive formats")),
OPT_GROUP(""),
OPT_STRING(0, "remote", &remote, N_("repo"),
N_("retrieve the archive from remote repository <repo>")),
OPT_STRING(0, "exec", &exec, N_("command"),
N_("path to the remote git-upload-archive command")),
OPT_END()
};
argc = parse_options(argc, argv, NULL, opts, archive_usage, 0);
if (remote)
die(_("Unexpected option --remote"));
if (exec)
die(_("the option '%s' requires '%s'"), "--exec", "--remote");
if (output)
die(_("Unexpected option --output"));
if (is_remote && args->extra_files.nr)
die(_("options '%s' and '%s' cannot be used together"), "--add-file", "--remote");
if (!base)
base = "";
if (list) {
for (i = 0; i < nr_archivers; i++)
if (!is_remote || archivers[i]->flags & ARCHIVER_REMOTE)
printf("%s\n", archivers[i]->name);
exit(0);
}
if (!format && name_hint)
format = archive_format_from_filename(name_hint);
if (!format)
format = "tar";
/* We need at least one parameter -- tree-ish */
if (argc < 1)
usage_with_options(archive_usage, opts);
*ar = lookup_archiver(format);
if (!*ar || (is_remote && !((*ar)->flags & ARCHIVER_REMOTE)))
die(_("Unknown archive format '%s'"), format);
args->compression_level = Z_DEFAULT_COMPRESSION;
if (compression_level != -1) {
int levels_ok = (*ar)->flags & ARCHIVER_WANT_COMPRESSION_LEVELS;
int high_ok = (*ar)->flags & ARCHIVER_HIGH_COMPRESSION_LEVELS;
if (levels_ok && (compression_level <= 9 || high_ok))
args->compression_level = compression_level;
else {
die(_("Argument not supported for format '%s': -%d"),
format, compression_level);
}
}
args->verbose = verbose;
args->base = base;
args->baselen = strlen(base);
args->worktree_attributes = worktree_attributes;
return argc;
}
int write_archive(int argc, const char **argv, const char *prefix,
struct repository *repo,
const char *name_hint, int remote)
{
const struct archiver *ar = NULL;
struct pretty_print_describe_status describe_status = {0};
struct pretty_print_context ctx = {0};
struct archiver_args args;
int rc;
git_config_get_bool("uploadarchive.allowunreachable", &remote_allow_unreachable);
git_config(git_default_config, NULL);
describe_status.max_invocations = 1;
ctx.date_mode.type = DATE_NORMAL;
ctx.abbrev = DEFAULT_ABBREV;
ctx.describe_status = &describe_status;
args.pretty_ctx = &ctx;
args.repo = repo;
args.prefix = prefix;
string_list_init_dup(&args.extra_files);
argc = parse_archive_args(argc, argv, &ar, &args, name_hint, remote);
if (!startup_info->have_repository) {
/*
* We know this will die() with an error, so we could just
* die ourselves; but its error message will be more specific
* than what we could write here.
*/
setup_git_directory();
}
parse_treeish_arg(argv, &args, prefix, remote);
parse_pathspec_arg(argv + 1, &args);
rc = ar->write_archive(ar, &args);
string_list_clear_func(&args.extra_files, extra_file_info_clear);
free(args.refname);
return rc;
}
static int match_extension(const char *filename, const char *ext)
{
int prefixlen = strlen(filename) - strlen(ext);
/*
* We need 1 character for the '.', and 1 character to ensure that the
* prefix is non-empty (k.e., we don't match .tar.gz with no actual
* filename).
*/
if (prefixlen < 2 || filename[prefixlen - 1] != '.')
return 0;
return !strcmp(filename + prefixlen, ext);
}
const char *archive_format_from_filename(const char *filename)
{
int i;
for (i = 0; i < nr_archivers; i++)
if (match_extension(filename, archivers[i]->name))
return archivers[i]->name;
return NULL;
}