git/submodule-config.c
Antonio Ospite 76e9bdc437 submodule: support reading .gitmodules when it's not in the working tree
When the .gitmodules file is not available in the working tree, try
using the content from the index and from the current branch. This
covers the case when the file is part of the repository but for some
reason it is not checked out, for example because of a sparse checkout.

This makes it possible to use at least the 'git submodule' commands
which *read* the gitmodules configuration file without fully populating
the working tree.

Writing to .gitmodules will still require that the file is checked out,
so check for that before calling config_set_in_gitmodules_file_gently.

Add a similar check also in git-submodule.sh::cmd_add() to anticipate
the eventual failure of the "git submodule add" command when .gitmodules
is not safely writeable; this prevents the command from leaving the
repository in a spurious state (e.g. the submodule repository was cloned
but .gitmodules was not updated because
config_set_in_gitmodules_file_gently failed).

Moreover, since config_from_gitmodules() now accesses the global object
store, it is necessary to protect all code paths which call the function
against concurrent access to the global object store. Currently this
only happens in builtin/grep.c::grep_submodules(), so call
grep_read_lock() before invoking code involving
config_from_gitmodules().

Finally, add t7418-submodule-sparse-gitmodules.sh to verify that reading
from .gitmodules succeeds and that writing to it fails when the file is
not checked out.

NOTE: there is one rare case where this new feature does not work
properly yet: nested submodules without .gitmodules in their working
tree.  This has been documented with a warning and a test_expect_failure
item in t7814, and in this case the current behavior is not altered: no
config is read.

Signed-off-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-31 15:01:30 +09:00

790 lines
20 KiB
C

#include "cache.h"
#include "dir.h"
#include "repository.h"
#include "config.h"
#include "submodule-config.h"
#include "submodule.h"
#include "strbuf.h"
#include "object-store.h"
#include "parse-options.h"
/*
* submodule cache lookup structure
* There is one shared set of 'struct submodule' entries which can be
* looked up by their sha1 blob id of the .gitmodules file and either
* using path or name as key.
* for_path stores submodule entries with path as key
* for_name stores submodule entries with name as key
*/
struct submodule_cache {
struct hashmap for_path;
struct hashmap for_name;
unsigned initialized:1;
unsigned gitmodules_read:1;
};
/*
* thin wrapper struct needed to insert 'struct submodule' entries to
* the hashmap
*/
struct submodule_entry {
struct hashmap_entry ent;
struct submodule *config;
};
enum lookup_type {
lookup_name,
lookup_path
};
static int config_path_cmp(const void *unused_cmp_data,
const void *entry,
const void *entry_or_key,
const void *unused_keydata)
{
const struct submodule_entry *a = entry;
const struct submodule_entry *b = entry_or_key;
return strcmp(a->config->path, b->config->path) ||
oidcmp(&a->config->gitmodules_oid, &b->config->gitmodules_oid);
}
static int config_name_cmp(const void *unused_cmp_data,
const void *entry,
const void *entry_or_key,
const void *unused_keydata)
{
const struct submodule_entry *a = entry;
const struct submodule_entry *b = entry_or_key;
return strcmp(a->config->name, b->config->name) ||
oidcmp(&a->config->gitmodules_oid, &b->config->gitmodules_oid);
}
static struct submodule_cache *submodule_cache_alloc(void)
{
return xcalloc(1, sizeof(struct submodule_cache));
}
static void submodule_cache_init(struct submodule_cache *cache)
{
hashmap_init(&cache->for_path, config_path_cmp, NULL, 0);
hashmap_init(&cache->for_name, config_name_cmp, NULL, 0);
cache->initialized = 1;
}
static void free_one_config(struct submodule_entry *entry)
{
free((void *) entry->config->path);
free((void *) entry->config->name);
free((void *) entry->config->branch);
free((void *) entry->config->update_strategy.command);
free(entry->config);
}
static void submodule_cache_clear(struct submodule_cache *cache)
{
struct hashmap_iter iter;
struct submodule_entry *entry;
if (!cache->initialized)
return;
/*
* We iterate over the name hash here to be symmetric with the
* allocation of struct submodule entries. Each is allocated by
* their .gitmodules blob sha1 and submodule name.
*/
hashmap_iter_init(&cache->for_name, &iter);
while ((entry = hashmap_iter_next(&iter)))
free_one_config(entry);
hashmap_free(&cache->for_path, 1);
hashmap_free(&cache->for_name, 1);
cache->initialized = 0;
cache->gitmodules_read = 0;
}
void submodule_cache_free(struct submodule_cache *cache)
{
submodule_cache_clear(cache);
free(cache);
}
static unsigned int hash_oid_string(const struct object_id *oid,
const char *string)
{
return memhash(oid->hash, the_hash_algo->rawsz) + strhash(string);
}
static void cache_put_path(struct submodule_cache *cache,
struct submodule *submodule)
{
unsigned int hash = hash_oid_string(&submodule->gitmodules_oid,
submodule->path);
struct submodule_entry *e = xmalloc(sizeof(*e));
hashmap_entry_init(e, hash);
e->config = submodule;
hashmap_put(&cache->for_path, e);
}
static void cache_remove_path(struct submodule_cache *cache,
struct submodule *submodule)
{
unsigned int hash = hash_oid_string(&submodule->gitmodules_oid,
submodule->path);
struct submodule_entry e;
struct submodule_entry *removed;
hashmap_entry_init(&e, hash);
e.config = submodule;
removed = hashmap_remove(&cache->for_path, &e, NULL);
free(removed);
}
static void cache_add(struct submodule_cache *cache,
struct submodule *submodule)
{
unsigned int hash = hash_oid_string(&submodule->gitmodules_oid,
submodule->name);
struct submodule_entry *e = xmalloc(sizeof(*e));
hashmap_entry_init(e, hash);
e->config = submodule;
hashmap_add(&cache->for_name, e);
}
static const struct submodule *cache_lookup_path(struct submodule_cache *cache,
const struct object_id *gitmodules_oid, const char *path)
{
struct submodule_entry *entry;
unsigned int hash = hash_oid_string(gitmodules_oid, path);
struct submodule_entry key;
struct submodule key_config;
oidcpy(&key_config.gitmodules_oid, gitmodules_oid);
key_config.path = path;
hashmap_entry_init(&key, hash);
key.config = &key_config;
entry = hashmap_get(&cache->for_path, &key, NULL);
if (entry)
return entry->config;
return NULL;
}
static struct submodule *cache_lookup_name(struct submodule_cache *cache,
const struct object_id *gitmodules_oid, const char *name)
{
struct submodule_entry *entry;
unsigned int hash = hash_oid_string(gitmodules_oid, name);
struct submodule_entry key;
struct submodule key_config;
oidcpy(&key_config.gitmodules_oid, gitmodules_oid);
key_config.name = name;
hashmap_entry_init(&key, hash);
key.config = &key_config;
entry = hashmap_get(&cache->for_name, &key, NULL);
if (entry)
return entry->config;
return NULL;
}
int check_submodule_name(const char *name)
{
/* Disallow empty names */
if (!*name)
return -1;
/*
* Look for '..' as a path component. Check both '/' and '\\' as
* separators rather than is_dir_sep(), because we want the name rules
* to be consistent across platforms.
*/
goto in_component; /* always start inside component */
while (*name) {
char c = *name++;
if (c == '/' || c == '\\') {
in_component:
if (name[0] == '.' && name[1] == '.' &&
(!name[2] || name[2] == '/' || name[2] == '\\'))
return -1;
}
}
return 0;
}
static int name_and_item_from_var(const char *var, struct strbuf *name,
struct strbuf *item)
{
const char *subsection, *key;
int subsection_len, parse;
parse = parse_config_key(var, "submodule", &subsection,
&subsection_len, &key);
if (parse < 0 || !subsection)
return 0;
strbuf_add(name, subsection, subsection_len);
if (check_submodule_name(name->buf) < 0) {
warning(_("ignoring suspicious submodule name: %s"), name->buf);
strbuf_release(name);
return 0;
}
strbuf_addstr(item, key);
return 1;
}
static struct submodule *lookup_or_create_by_name(struct submodule_cache *cache,
const struct object_id *gitmodules_oid, const char *name)
{
struct submodule *submodule;
struct strbuf name_buf = STRBUF_INIT;
submodule = cache_lookup_name(cache, gitmodules_oid, name);
if (submodule)
return submodule;
submodule = xmalloc(sizeof(*submodule));
strbuf_addstr(&name_buf, name);
submodule->name = strbuf_detach(&name_buf, NULL);
submodule->path = NULL;
submodule->url = NULL;
submodule->update_strategy.type = SM_UPDATE_UNSPECIFIED;
submodule->update_strategy.command = NULL;
submodule->fetch_recurse = RECURSE_SUBMODULES_NONE;
submodule->ignore = NULL;
submodule->branch = NULL;
submodule->recommend_shallow = -1;
oidcpy(&submodule->gitmodules_oid, gitmodules_oid);
cache_add(cache, submodule);
return submodule;
}
static int parse_fetch_recurse(const char *opt, const char *arg,
int die_on_error)
{
switch (git_parse_maybe_bool(arg)) {
case 1:
return RECURSE_SUBMODULES_ON;
case 0:
return RECURSE_SUBMODULES_OFF;
default:
if (!strcmp(arg, "on-demand"))
return RECURSE_SUBMODULES_ON_DEMAND;
if (die_on_error)
die("bad %s argument: %s", opt, arg);
else
return RECURSE_SUBMODULES_ERROR;
}
}
int parse_submodule_fetchjobs(const char *var, const char *value)
{
int fetchjobs = git_config_int(var, value);
if (fetchjobs < 0)
die(_("negative values not allowed for submodule.fetchjobs"));
return fetchjobs;
}
int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
{
return parse_fetch_recurse(opt, arg, 1);
}
int option_fetch_parse_recurse_submodules(const struct option *opt,
const char *arg, int unset)
{
int *v;
if (!opt->value)
return -1;
v = opt->value;
if (unset) {
*v = RECURSE_SUBMODULES_OFF;
} else {
if (arg)
*v = parse_fetch_recurse_submodules_arg(opt->long_name, arg);
else
*v = RECURSE_SUBMODULES_ON;
}
return 0;
}
static int parse_update_recurse(const char *opt, const char *arg,
int die_on_error)
{
switch (git_parse_maybe_bool(arg)) {
case 1:
return RECURSE_SUBMODULES_ON;
case 0:
return RECURSE_SUBMODULES_OFF;
default:
if (die_on_error)
die("bad %s argument: %s", opt, arg);
return RECURSE_SUBMODULES_ERROR;
}
}
int parse_update_recurse_submodules_arg(const char *opt, const char *arg)
{
return parse_update_recurse(opt, arg, 1);
}
static int parse_push_recurse(const char *opt, const char *arg,
int die_on_error)
{
switch (git_parse_maybe_bool(arg)) {
case 1:
/* There's no simple "on" value when pushing */
if (die_on_error)
die("bad %s argument: %s", opt, arg);
else
return RECURSE_SUBMODULES_ERROR;
case 0:
return RECURSE_SUBMODULES_OFF;
default:
if (!strcmp(arg, "on-demand"))
return RECURSE_SUBMODULES_ON_DEMAND;
else if (!strcmp(arg, "check"))
return RECURSE_SUBMODULES_CHECK;
else if (!strcmp(arg, "only"))
return RECURSE_SUBMODULES_ONLY;
else if (die_on_error)
die("bad %s argument: %s", opt, arg);
else
return RECURSE_SUBMODULES_ERROR;
}
}
int parse_push_recurse_submodules_arg(const char *opt, const char *arg)
{
return parse_push_recurse(opt, arg, 1);
}
static void warn_multiple_config(const struct object_id *treeish_name,
const char *name, const char *option)
{
const char *commit_string = "WORKTREE";
if (treeish_name)
commit_string = oid_to_hex(treeish_name);
warning("%s:.gitmodules, multiple configurations found for "
"'submodule.%s.%s'. Skipping second one!",
commit_string, name, option);
}
struct parse_config_parameter {
struct submodule_cache *cache;
const struct object_id *treeish_name;
const struct object_id *gitmodules_oid;
int overwrite;
};
static int parse_config(const char *var, const char *value, void *data)
{
struct parse_config_parameter *me = data;
struct submodule *submodule;
struct strbuf name = STRBUF_INIT, item = STRBUF_INIT;
int ret = 0;
/* this also ensures that we only parse submodule entries */
if (!name_and_item_from_var(var, &name, &item))
return 0;
submodule = lookup_or_create_by_name(me->cache,
me->gitmodules_oid,
name.buf);
if (!strcmp(item.buf, "path")) {
if (!value)
ret = config_error_nonbool(var);
else if (!me->overwrite && submodule->path)
warn_multiple_config(me->treeish_name, submodule->name,
"path");
else {
if (submodule->path)
cache_remove_path(me->cache, submodule);
free((void *) submodule->path);
submodule->path = xstrdup(value);
cache_put_path(me->cache, submodule);
}
} else if (!strcmp(item.buf, "fetchrecursesubmodules")) {
/* when parsing worktree configurations we can die early */
int die_on_error = is_null_oid(me->gitmodules_oid);
if (!me->overwrite &&
submodule->fetch_recurse != RECURSE_SUBMODULES_NONE)
warn_multiple_config(me->treeish_name, submodule->name,
"fetchrecursesubmodules");
else
submodule->fetch_recurse = parse_fetch_recurse(
var, value,
die_on_error);
} else if (!strcmp(item.buf, "ignore")) {
if (!value)
ret = config_error_nonbool(var);
else if (!me->overwrite && submodule->ignore)
warn_multiple_config(me->treeish_name, submodule->name,
"ignore");
else if (strcmp(value, "untracked") &&
strcmp(value, "dirty") &&
strcmp(value, "all") &&
strcmp(value, "none"))
warning("Invalid parameter '%s' for config option "
"'submodule.%s.ignore'", value, name.buf);
else {
free((void *) submodule->ignore);
submodule->ignore = xstrdup(value);
}
} else if (!strcmp(item.buf, "url")) {
if (!value) {
ret = config_error_nonbool(var);
} else if (!me->overwrite && submodule->url) {
warn_multiple_config(me->treeish_name, submodule->name,
"url");
} else {
free((void *) submodule->url);
submodule->url = xstrdup(value);
}
} else if (!strcmp(item.buf, "update")) {
if (!value)
ret = config_error_nonbool(var);
else if (!me->overwrite &&
submodule->update_strategy.type != SM_UPDATE_UNSPECIFIED)
warn_multiple_config(me->treeish_name, submodule->name,
"update");
else if (parse_submodule_update_strategy(value,
&submodule->update_strategy) < 0)
die(_("invalid value for %s"), var);
} else if (!strcmp(item.buf, "shallow")) {
if (!me->overwrite && submodule->recommend_shallow != -1)
warn_multiple_config(me->treeish_name, submodule->name,
"shallow");
else
submodule->recommend_shallow =
git_config_bool(var, value);
} else if (!strcmp(item.buf, "branch")) {
if (!me->overwrite && submodule->branch)
warn_multiple_config(me->treeish_name, submodule->name,
"branch");
else {
free((void *)submodule->branch);
submodule->branch = xstrdup(value);
}
}
strbuf_release(&name);
strbuf_release(&item);
return ret;
}
static int gitmodule_oid_from_commit(const struct object_id *treeish_name,
struct object_id *gitmodules_oid,
struct strbuf *rev)
{
int ret = 0;
if (is_null_oid(treeish_name)) {
oidclr(gitmodules_oid);
return 1;
}
strbuf_addf(rev, "%s:.gitmodules", oid_to_hex(treeish_name));
if (get_oid(rev->buf, gitmodules_oid) >= 0)
ret = 1;
return ret;
}
/* This does a lookup of a submodule configuration by name or by path
* (key) with on-demand reading of the appropriate .gitmodules from
* revisions.
*/
static const struct submodule *config_from(struct submodule_cache *cache,
const struct object_id *treeish_name, const char *key,
enum lookup_type lookup_type)
{
struct strbuf rev = STRBUF_INIT;
unsigned long config_size;
char *config = NULL;
struct object_id oid;
enum object_type type;
const struct submodule *submodule = NULL;
struct parse_config_parameter parameter;
/*
* If any parameter except the cache is a NULL pointer just
* return the first submodule. Can be used to check whether
* there are any submodules parsed.
*/
if (!treeish_name || !key) {
struct hashmap_iter iter;
struct submodule_entry *entry;
entry = hashmap_iter_first(&cache->for_name, &iter);
if (!entry)
return NULL;
return entry->config;
}
if (!gitmodule_oid_from_commit(treeish_name, &oid, &rev))
goto out;
switch (lookup_type) {
case lookup_name:
submodule = cache_lookup_name(cache, &oid, key);
break;
case lookup_path:
submodule = cache_lookup_path(cache, &oid, key);
break;
}
if (submodule)
goto out;
config = read_object_file(&oid, &type, &config_size);
if (!config || type != OBJ_BLOB)
goto out;
/* fill the submodule config into the cache */
parameter.cache = cache;
parameter.treeish_name = treeish_name;
parameter.gitmodules_oid = &oid;
parameter.overwrite = 0;
git_config_from_mem(parse_config, CONFIG_ORIGIN_SUBMODULE_BLOB, rev.buf,
config, config_size, &parameter, NULL);
strbuf_release(&rev);
free(config);
switch (lookup_type) {
case lookup_name:
return cache_lookup_name(cache, &oid, key);
case lookup_path:
return cache_lookup_path(cache, &oid, key);
default:
return NULL;
}
out:
strbuf_release(&rev);
free(config);
return submodule;
}
static void submodule_cache_check_init(struct repository *repo)
{
if (repo->submodule_cache && repo->submodule_cache->initialized)
return;
if (!repo->submodule_cache)
repo->submodule_cache = submodule_cache_alloc();
submodule_cache_init(repo->submodule_cache);
}
/*
* Note: This function is private for a reason, the '.gitmodules' file should
* not be used as as a mechanism to retrieve arbitrary configuration stored in
* the repository.
*
* Runs the provided config function on the '.gitmodules' file found in the
* working directory.
*/
static void config_from_gitmodules(config_fn_t fn, struct repository *repo, void *data)
{
if (repo->worktree) {
struct git_config_source config_source = { 0 };
const struct config_options opts = { 0 };
struct object_id oid;
char *file;
file = repo_worktree_path(repo, GITMODULES_FILE);
if (file_exists(file)) {
config_source.file = file;
} else if (repo->submodule_prefix) {
/*
* When get_oid and config_with_options, used below,
* become able to work on a specific repository, this
* warning branch can be removed.
*/
warning("nested submodules without %s in the working tree are not supported yet",
GITMODULES_FILE);
goto out;
} else if (get_oid(GITMODULES_INDEX, &oid) >= 0) {
config_source.blob = GITMODULES_INDEX;
} else if (get_oid(GITMODULES_HEAD, &oid) >= 0) {
config_source.blob = GITMODULES_HEAD;
} else {
goto out;
}
config_with_options(fn, data, &config_source, &opts);
out:
free(file);
}
}
static int gitmodules_cb(const char *var, const char *value, void *data)
{
struct repository *repo = data;
struct parse_config_parameter parameter;
parameter.cache = repo->submodule_cache;
parameter.treeish_name = NULL;
parameter.gitmodules_oid = &null_oid;
parameter.overwrite = 1;
return parse_config(var, value, &parameter);
}
void repo_read_gitmodules(struct repository *repo)
{
submodule_cache_check_init(repo);
if (repo_read_index(repo) < 0)
return;
if (!is_gitmodules_unmerged(repo->index))
config_from_gitmodules(gitmodules_cb, repo, repo);
repo->submodule_cache->gitmodules_read = 1;
}
void gitmodules_config_oid(const struct object_id *commit_oid)
{
struct strbuf rev = STRBUF_INIT;
struct object_id oid;
submodule_cache_check_init(the_repository);
if (gitmodule_oid_from_commit(commit_oid, &oid, &rev)) {
git_config_from_blob_oid(gitmodules_cb, rev.buf,
&oid, the_repository);
}
strbuf_release(&rev);
the_repository->submodule_cache->gitmodules_read = 1;
}
static void gitmodules_read_check(struct repository *repo)
{
submodule_cache_check_init(repo);
/* read the repo's .gitmodules file if it hasn't been already */
if (!repo->submodule_cache->gitmodules_read)
repo_read_gitmodules(repo);
}
const struct submodule *submodule_from_name(struct repository *r,
const struct object_id *treeish_name,
const char *name)
{
gitmodules_read_check(r);
return config_from(r->submodule_cache, treeish_name, name, lookup_name);
}
const struct submodule *submodule_from_path(struct repository *r,
const struct object_id *treeish_name,
const char *path)
{
gitmodules_read_check(r);
return config_from(r->submodule_cache, treeish_name, path, lookup_path);
}
void submodule_free(struct repository *r)
{
if (r->submodule_cache)
submodule_cache_clear(r->submodule_cache);
}
static int config_print_callback(const char *var, const char *value, void *cb_data)
{
char *wanted_key = cb_data;
if (!strcmp(wanted_key, var))
printf("%s\n", value);
return 0;
}
int print_config_from_gitmodules(struct repository *repo, const char *key)
{
int ret;
char *store_key;
ret = git_config_parse_key(key, &store_key, NULL);
if (ret < 0)
return CONFIG_INVALID_KEY;
config_from_gitmodules(config_print_callback, repo, store_key);
free(store_key);
return 0;
}
int config_set_in_gitmodules_file_gently(const char *key, const char *value)
{
int ret;
ret = git_config_set_in_file_gently(GITMODULES_FILE, key, value);
if (ret < 0)
/* Maybe the user already did that, don't error out here */
warning(_("Could not update .gitmodules entry %s"), key);
return ret;
}
struct fetch_config {
int *max_children;
int *recurse_submodules;
};
static int gitmodules_fetch_config(const char *var, const char *value, void *cb)
{
struct fetch_config *config = cb;
if (!strcmp(var, "submodule.fetchjobs")) {
*(config->max_children) = parse_submodule_fetchjobs(var, value);
return 0;
} else if (!strcmp(var, "fetch.recursesubmodules")) {
*(config->recurse_submodules) = parse_fetch_recurse_submodules_arg(var, value);
return 0;
}
return 0;
}
void fetch_config_from_gitmodules(int *max_children, int *recurse_submodules)
{
struct fetch_config config = {
.max_children = max_children,
.recurse_submodules = recurse_submodules
};
config_from_gitmodules(gitmodules_fetch_config, the_repository, &config);
}
static int gitmodules_update_clone_config(const char *var, const char *value,
void *cb)
{
int *max_jobs = cb;
if (!strcmp(var, "submodule.fetchjobs"))
*max_jobs = parse_submodule_fetchjobs(var, value);
return 0;
}
void update_clone_config_from_gitmodules(int *max_jobs)
{
config_from_gitmodules(gitmodules_update_clone_config, the_repository, &max_jobs);
}