git/commit.c
Junio C Hamano dea6737bb7 Merge branch 'ds/close-object-store' into maint
The commit-graph file is now part of the "files that the runtime
may keep open file descriptors on, all of which would need to be
closed when done with the object store", and the file descriptor to
an existing commit-graph file now is closed before "gc" finalizes a
new instance to replace it.

* ds/close-object-store:
  packfile: rename close_all_packs to close_object_store
  packfile: close commit-graph in close_all_packs
  commit-graph: use raw_object_store when closing
  commit-graph: extract write_commit_graph_file()
  commit-graph: extract copy_oids_to_commits()
  commit-graph: extract count_distinct_commits()
  commit-graph: extract fill_oids_from_all_packs()
  commit-graph: extract fill_oids_from_commit_hex()
  commit-graph: extract fill_oids_from_packs()
  commit-graph: create write_commit_graph_context
  commit-graph: remove Future Work section
  commit-graph: collapse parameters into flags
  commit-graph: return with errors during write
  commit-graph: fix the_repository reference
2019-07-29 12:38:22 -07:00

1583 lines
39 KiB
C

#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "commit-graph.h"
#include "repository.h"
#include "object-store.h"
#include "pkt-line.h"
#include "utf8.h"
#include "diff.h"
#include "revision.h"
#include "notes.h"
#include "alloc.h"
#include "gpg-interface.h"
#include "mergesort.h"
#include "commit-slab.h"
#include "prio-queue.h"
#include "sha1-lookup.h"
#include "wt-status.h"
#include "advice.h"
#include "refs.h"
#include "commit-reach.h"
static struct commit_extra_header *read_commit_extra_header_lines(const char *buf, size_t len, const char **);
int save_commit_buffer = 1;
const char *commit_type = "commit";
struct commit *lookup_commit_reference_gently(struct repository *r,
const struct object_id *oid, int quiet)
{
struct object *obj = deref_tag(r,
parse_object(r, oid),
NULL, 0);
if (!obj)
return NULL;
return object_as_type(r, obj, OBJ_COMMIT, quiet);
}
struct commit *lookup_commit_reference(struct repository *r, const struct object_id *oid)
{
return lookup_commit_reference_gently(r, oid, 0);
}
struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name)
{
struct commit *c = lookup_commit_reference(the_repository, oid);
if (!c)
die(_("could not parse %s"), ref_name);
if (!oideq(oid, &c->object.oid)) {
warning(_("%s %s is not a commit!"),
ref_name, oid_to_hex(oid));
}
return c;
}
struct commit *lookup_commit(struct repository *r, const struct object_id *oid)
{
struct object *obj = lookup_object(r, oid);
if (!obj)
return create_object(r, oid, alloc_commit_node(r));
return object_as_type(r, obj, OBJ_COMMIT, 0);
}
struct commit *lookup_commit_reference_by_name(const char *name)
{
struct object_id oid;
struct commit *commit;
if (get_oid_committish(name, &oid))
return NULL;
commit = lookup_commit_reference(the_repository, &oid);
if (parse_commit(commit))
return NULL;
return commit;
}
static timestamp_t parse_commit_date(const char *buf, const char *tail)
{
const char *dateptr;
if (buf + 6 >= tail)
return 0;
if (memcmp(buf, "author", 6))
return 0;
while (buf < tail && *buf++ != '\n')
/* nada */;
if (buf + 9 >= tail)
return 0;
if (memcmp(buf, "committer", 9))
return 0;
while (buf < tail && *buf++ != '>')
/* nada */;
if (buf >= tail)
return 0;
dateptr = buf;
while (buf < tail && *buf++ != '\n')
/* nada */;
if (buf >= tail)
return 0;
/* dateptr < buf && buf[-1] == '\n', so parsing will stop at buf-1 */
return parse_timestamp(dateptr, NULL, 10);
}
static const unsigned char *commit_graft_sha1_access(size_t index, void *table)
{
struct commit_graft **commit_graft_table = table;
return commit_graft_table[index]->oid.hash;
}
static int commit_graft_pos(struct repository *r, const unsigned char *sha1)
{
return sha1_pos(sha1, r->parsed_objects->grafts,
r->parsed_objects->grafts_nr,
commit_graft_sha1_access);
}
int register_commit_graft(struct repository *r, struct commit_graft *graft,
int ignore_dups)
{
int pos = commit_graft_pos(r, graft->oid.hash);
if (0 <= pos) {
if (ignore_dups)
free(graft);
else {
free(r->parsed_objects->grafts[pos]);
r->parsed_objects->grafts[pos] = graft;
}
return 1;
}
pos = -pos - 1;
ALLOC_GROW(r->parsed_objects->grafts,
r->parsed_objects->grafts_nr + 1,
r->parsed_objects->grafts_alloc);
r->parsed_objects->grafts_nr++;
if (pos < r->parsed_objects->grafts_nr)
memmove(r->parsed_objects->grafts + pos + 1,
r->parsed_objects->grafts + pos,
(r->parsed_objects->grafts_nr - pos - 1) *
sizeof(*r->parsed_objects->grafts));
r->parsed_objects->grafts[pos] = graft;
return 0;
}
struct commit_graft *read_graft_line(struct strbuf *line)
{
/* The format is just "Commit Parent1 Parent2 ...\n" */
int i, phase;
const char *tail = NULL;
struct commit_graft *graft = NULL;
struct object_id dummy_oid, *oid;
strbuf_rtrim(line);
if (!line->len || line->buf[0] == '#')
return NULL;
/*
* phase 0 verifies line, counts hashes in line and allocates graft
* phase 1 fills graft
*/
for (phase = 0; phase < 2; phase++) {
oid = graft ? &graft->oid : &dummy_oid;
if (parse_oid_hex(line->buf, oid, &tail))
goto bad_graft_data;
for (i = 0; *tail != '\0'; i++) {
oid = graft ? &graft->parent[i] : &dummy_oid;
if (!isspace(*tail++) || parse_oid_hex(tail, oid, &tail))
goto bad_graft_data;
}
if (!graft) {
graft = xmalloc(st_add(sizeof(*graft),
st_mult(sizeof(struct object_id), i)));
graft->nr_parent = i;
}
}
return graft;
bad_graft_data:
error("bad graft data: %s", line->buf);
assert(!graft);
return NULL;
}
static int read_graft_file(struct repository *r, const char *graft_file)
{
FILE *fp = fopen_or_warn(graft_file, "r");
struct strbuf buf = STRBUF_INIT;
if (!fp)
return -1;
if (advice_graft_file_deprecated)
advise(_("Support for <GIT_DIR>/info/grafts is deprecated\n"
"and will be removed in a future Git version.\n"
"\n"
"Please use \"git replace --convert-graft-file\"\n"
"to convert the grafts into replace refs.\n"
"\n"
"Turn this message off by running\n"
"\"git config advice.graftFileDeprecated false\""));
while (!strbuf_getwholeline(&buf, fp, '\n')) {
/* The format is just "Commit Parent1 Parent2 ...\n" */
struct commit_graft *graft = read_graft_line(&buf);
if (!graft)
continue;
if (register_commit_graft(r, graft, 1))
error("duplicate graft data: %s", buf.buf);
}
fclose(fp);
strbuf_release(&buf);
return 0;
}
void prepare_commit_graft(struct repository *r)
{
char *graft_file;
if (r->parsed_objects->commit_graft_prepared)
return;
if (!startup_info->have_repository)
return;
graft_file = get_graft_file(r);
read_graft_file(r, graft_file);
/* make sure shallows are read */
is_repository_shallow(r);
r->parsed_objects->commit_graft_prepared = 1;
}
struct commit_graft *lookup_commit_graft(struct repository *r, const struct object_id *oid)
{
int pos;
prepare_commit_graft(r);
pos = commit_graft_pos(r, oid->hash);
if (pos < 0)
return NULL;
return r->parsed_objects->grafts[pos];
}
int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
{
int i, ret;
for (i = ret = 0; i < the_repository->parsed_objects->grafts_nr && !ret; i++)
ret = fn(the_repository->parsed_objects->grafts[i], cb_data);
return ret;
}
int unregister_shallow(const struct object_id *oid)
{
int pos = commit_graft_pos(the_repository, oid->hash);
if (pos < 0)
return -1;
if (pos + 1 < the_repository->parsed_objects->grafts_nr)
MOVE_ARRAY(the_repository->parsed_objects->grafts + pos,
the_repository->parsed_objects->grafts + pos + 1,
the_repository->parsed_objects->grafts_nr - pos - 1);
the_repository->parsed_objects->grafts_nr--;
return 0;
}
struct commit_buffer {
void *buffer;
unsigned long size;
};
define_commit_slab(buffer_slab, struct commit_buffer);
struct buffer_slab *allocate_commit_buffer_slab(void)
{
struct buffer_slab *bs = xmalloc(sizeof(*bs));
init_buffer_slab(bs);
return bs;
}
void free_commit_buffer_slab(struct buffer_slab *bs)
{
clear_buffer_slab(bs);
free(bs);
}
void set_commit_buffer(struct repository *r, struct commit *commit, void *buffer, unsigned long size)
{
struct commit_buffer *v = buffer_slab_at(
r->parsed_objects->buffer_slab, commit);
v->buffer = buffer;
v->size = size;
}
const void *get_cached_commit_buffer(struct repository *r, const struct commit *commit, unsigned long *sizep)
{
struct commit_buffer *v = buffer_slab_peek(
r->parsed_objects->buffer_slab, commit);
if (!v) {
if (sizep)
*sizep = 0;
return NULL;
}
if (sizep)
*sizep = v->size;
return v->buffer;
}
const void *repo_get_commit_buffer(struct repository *r,
const struct commit *commit,
unsigned long *sizep)
{
const void *ret = get_cached_commit_buffer(r, commit, sizep);
if (!ret) {
enum object_type type;
unsigned long size;
ret = repo_read_object_file(r, &commit->object.oid, &type, &size);
if (!ret)
die("cannot read commit object %s",
oid_to_hex(&commit->object.oid));
if (type != OBJ_COMMIT)
die("expected commit for %s, got %s",
oid_to_hex(&commit->object.oid), type_name(type));
if (sizep)
*sizep = size;
}
return ret;
}
void repo_unuse_commit_buffer(struct repository *r,
const struct commit *commit,
const void *buffer)
{
struct commit_buffer *v = buffer_slab_peek(
r->parsed_objects->buffer_slab, commit);
if (!(v && v->buffer == buffer))
free((void *)buffer);
}
void free_commit_buffer(struct parsed_object_pool *pool, struct commit *commit)
{
struct commit_buffer *v = buffer_slab_peek(
pool->buffer_slab, commit);
if (v) {
FREE_AND_NULL(v->buffer);
v->size = 0;
}
}
static inline void set_commit_tree(struct commit *c, struct tree *t)
{
c->maybe_tree = t;
}
struct tree *repo_get_commit_tree(struct repository *r,
const struct commit *commit)
{
if (commit->maybe_tree || !commit->object.parsed)
return commit->maybe_tree;
if (commit->graph_pos != COMMIT_NOT_FROM_GRAPH)
return get_commit_tree_in_graph(r, commit);
return NULL;
}
struct object_id *get_commit_tree_oid(const struct commit *commit)
{
return &get_commit_tree(commit)->object.oid;
}
void release_commit_memory(struct parsed_object_pool *pool, struct commit *c)
{
set_commit_tree(c, NULL);
c->index = 0;
free_commit_buffer(pool, c);
free_commit_list(c->parents);
c->object.parsed = 0;
}
const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
{
struct commit_buffer *v = buffer_slab_peek(
the_repository->parsed_objects->buffer_slab, commit);
void *ret;
if (!v) {
if (sizep)
*sizep = 0;
return NULL;
}
ret = v->buffer;
if (sizep)
*sizep = v->size;
v->buffer = NULL;
v->size = 0;
return ret;
}
int parse_commit_buffer(struct repository *r, struct commit *item, const void *buffer, unsigned long size, int check_graph)
{
const char *tail = buffer;
const char *bufptr = buffer;
struct object_id parent;
struct commit_list **pptr;
struct commit_graft *graft;
const int tree_entry_len = the_hash_algo->hexsz + 5;
const int parent_entry_len = the_hash_algo->hexsz + 7;
if (item->object.parsed)
return 0;
item->object.parsed = 1;
tail += size;
if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||
bufptr[tree_entry_len] != '\n')
return error("bogus commit object %s", oid_to_hex(&item->object.oid));
if (get_oid_hex(bufptr + 5, &parent) < 0)
return error("bad tree pointer in commit %s",
oid_to_hex(&item->object.oid));
set_commit_tree(item, lookup_tree(r, &parent));
bufptr += tree_entry_len + 1; /* "tree " + "hex sha1" + "\n" */
pptr = &item->parents;
graft = lookup_commit_graft(r, &item->object.oid);
while (bufptr + parent_entry_len < tail && !memcmp(bufptr, "parent ", 7)) {
struct commit *new_parent;
if (tail <= bufptr + parent_entry_len + 1 ||
get_oid_hex(bufptr + 7, &parent) ||
bufptr[parent_entry_len] != '\n')
return error("bad parents in commit %s", oid_to_hex(&item->object.oid));
bufptr += parent_entry_len + 1;
/*
* The clone is shallow if nr_parent < 0, and we must
* not traverse its real parents even when we unhide them.
*/
if (graft && (graft->nr_parent < 0 || grafts_replace_parents))
continue;
new_parent = lookup_commit(r, &parent);
if (new_parent)
pptr = &commit_list_insert(new_parent, pptr)->next;
}
if (graft) {
int i;
struct commit *new_parent;
for (i = 0; i < graft->nr_parent; i++) {
new_parent = lookup_commit(r,
&graft->parent[i]);
if (!new_parent)
continue;
pptr = &commit_list_insert(new_parent, pptr)->next;
}
}
item->date = parse_commit_date(bufptr, tail);
if (check_graph)
load_commit_graph_info(r, item);
return 0;
}
int repo_parse_commit_internal(struct repository *r,
struct commit *item,
int quiet_on_missing,
int use_commit_graph)
{
enum object_type type;
void *buffer;
unsigned long size;
int ret;
if (!item)
return -1;
if (item->object.parsed)
return 0;
if (use_commit_graph && parse_commit_in_graph(r, item))
return 0;
buffer = repo_read_object_file(r, &item->object.oid, &type, &size);
if (!buffer)
return quiet_on_missing ? -1 :
error("Could not read %s",
oid_to_hex(&item->object.oid));
if (type != OBJ_COMMIT) {
free(buffer);
return error("Object %s not a commit",
oid_to_hex(&item->object.oid));
}
ret = parse_commit_buffer(r, item, buffer, size, 0);
if (save_commit_buffer && !ret) {
set_commit_buffer(r, item, buffer, size);
return 0;
}
free(buffer);
return ret;
}
int repo_parse_commit_gently(struct repository *r,
struct commit *item, int quiet_on_missing)
{
return repo_parse_commit_internal(r, item, quiet_on_missing, 1);
}
void parse_commit_or_die(struct commit *item)
{
if (parse_commit(item))
die("unable to parse commit %s",
item ? oid_to_hex(&item->object.oid) : "(null)");
}
int find_commit_subject(const char *commit_buffer, const char **subject)
{
const char *eol;
const char *p = commit_buffer;
while (*p && (*p != '\n' || p[1] != '\n'))
p++;
if (*p) {
p = skip_blank_lines(p + 2);
eol = strchrnul(p, '\n');
} else
eol = p;
*subject = p;
return eol - p;
}
struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
{
struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
new_list->item = item;
new_list->next = *list_p;
*list_p = new_list;
return new_list;
}
unsigned commit_list_count(const struct commit_list *l)
{
unsigned c = 0;
for (; l; l = l->next )
c++;
return c;
}
struct commit_list *copy_commit_list(struct commit_list *list)
{
struct commit_list *head = NULL;
struct commit_list **pp = &head;
while (list) {
pp = commit_list_append(list->item, pp);
list = list->next;
}
return head;
}
void free_commit_list(struct commit_list *list)
{
while (list)
pop_commit(&list);
}
struct commit_list * commit_list_insert_by_date(struct commit *item, struct commit_list **list)
{
struct commit_list **pp = list;
struct commit_list *p;
while ((p = *pp) != NULL) {
if (p->item->date < item->date) {
break;
}
pp = &p->next;
}
return commit_list_insert(item, pp);
}
static int commit_list_compare_by_date(const void *a, const void *b)
{
timestamp_t a_date = ((const struct commit_list *)a)->item->date;
timestamp_t b_date = ((const struct commit_list *)b)->item->date;
if (a_date < b_date)
return 1;
if (a_date > b_date)
return -1;
return 0;
}
static void *commit_list_get_next(const void *a)
{
return ((const struct commit_list *)a)->next;
}
static void commit_list_set_next(void *a, void *next)
{
((struct commit_list *)a)->next = next;
}
void commit_list_sort_by_date(struct commit_list **list)
{
*list = llist_mergesort(*list, commit_list_get_next, commit_list_set_next,
commit_list_compare_by_date);
}
struct commit *pop_most_recent_commit(struct commit_list **list,
unsigned int mark)
{
struct commit *ret = pop_commit(list);
struct commit_list *parents = ret->parents;
while (parents) {
struct commit *commit = parents->item;
if (!parse_commit(commit) && !(commit->object.flags & mark)) {
commit->object.flags |= mark;
commit_list_insert_by_date(commit, list);
}
parents = parents->next;
}
return ret;
}
static void clear_commit_marks_1(struct commit_list **plist,
struct commit *commit, unsigned int mark)
{
while (commit) {
struct commit_list *parents;
if (!(mark & commit->object.flags))
return;
commit->object.flags &= ~mark;
parents = commit->parents;
if (!parents)
return;
while ((parents = parents->next))
commit_list_insert(parents->item, plist);
commit = commit->parents->item;
}
}
void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark)
{
struct commit_list *list = NULL;
while (nr--) {
clear_commit_marks_1(&list, *commit, mark);
commit++;
}
while (list)
clear_commit_marks_1(&list, pop_commit(&list), mark);
}
void clear_commit_marks(struct commit *commit, unsigned int mark)
{
clear_commit_marks_many(1, &commit, mark);
}
struct commit *pop_commit(struct commit_list **stack)
{
struct commit_list *top = *stack;
struct commit *item = top ? top->item : NULL;
if (top) {
*stack = top->next;
free(top);
}
return item;
}
/*
* Topological sort support
*/
/* count number of children that have not been emitted */
define_commit_slab(indegree_slab, int);
define_commit_slab(author_date_slab, timestamp_t);
void record_author_date(struct author_date_slab *author_date,
struct commit *commit)
{
const char *buffer = get_commit_buffer(commit, NULL);
struct ident_split ident;
const char *ident_line;
size_t ident_len;
char *date_end;
timestamp_t date;
ident_line = find_commit_header(buffer, "author", &ident_len);
if (!ident_line)
goto fail_exit; /* no author line */
if (split_ident_line(&ident, ident_line, ident_len) ||
!ident.date_begin || !ident.date_end)
goto fail_exit; /* malformed "author" line */
date = parse_timestamp(ident.date_begin, &date_end, 10);
if (date_end != ident.date_end)
goto fail_exit; /* malformed date */
*(author_date_slab_at(author_date, commit)) = date;
fail_exit:
unuse_commit_buffer(commit, buffer);
}
int compare_commits_by_author_date(const void *a_, const void *b_,
void *cb_data)
{
const struct commit *a = a_, *b = b_;
struct author_date_slab *author_date = cb_data;
timestamp_t a_date = *(author_date_slab_at(author_date, a));
timestamp_t b_date = *(author_date_slab_at(author_date, b));
/* newer commits with larger date first */
if (a_date < b_date)
return 1;
else if (a_date > b_date)
return -1;
return 0;
}
int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused)
{
const struct commit *a = a_, *b = b_;
/* newer commits first */
if (a->generation < b->generation)
return 1;
else if (a->generation > b->generation)
return -1;
/* use date as a heuristic when generations are equal */
if (a->date < b->date)
return 1;
else if (a->date > b->date)
return -1;
return 0;
}
int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
{
const struct commit *a = a_, *b = b_;
/* newer commits with larger date first */
if (a->date < b->date)
return 1;
else if (a->date > b->date)
return -1;
return 0;
}
/*
* Performs an in-place topological sort on the list supplied.
*/
void sort_in_topological_order(struct commit_list **list, enum rev_sort_order sort_order)
{
struct commit_list *next, *orig = *list;
struct commit_list **pptr;
struct indegree_slab indegree;
struct prio_queue queue;
struct commit *commit;
struct author_date_slab author_date;
if (!orig)
return;
*list = NULL;
init_indegree_slab(&indegree);
memset(&queue, '\0', sizeof(queue));
switch (sort_order) {
default: /* REV_SORT_IN_GRAPH_ORDER */
queue.compare = NULL;
break;
case REV_SORT_BY_COMMIT_DATE:
queue.compare = compare_commits_by_commit_date;
break;
case REV_SORT_BY_AUTHOR_DATE:
init_author_date_slab(&author_date);
queue.compare = compare_commits_by_author_date;
queue.cb_data = &author_date;
break;
}
/* Mark them and clear the indegree */
for (next = orig; next; next = next->next) {
struct commit *commit = next->item;
*(indegree_slab_at(&indegree, commit)) = 1;
/* also record the author dates, if needed */
if (sort_order == REV_SORT_BY_AUTHOR_DATE)
record_author_date(&author_date, commit);
}
/* update the indegree */
for (next = orig; next; next = next->next) {
struct commit_list *parents = next->item->parents;
while (parents) {
struct commit *parent = parents->item;
int *pi = indegree_slab_at(&indegree, parent);
if (*pi)
(*pi)++;
parents = parents->next;
}
}
/*
* find the tips
*
* tips are nodes not reachable from any other node in the list
*
* the tips serve as a starting set for the work queue.
*/
for (next = orig; next; next = next->next) {
struct commit *commit = next->item;
if (*(indegree_slab_at(&indegree, commit)) == 1)
prio_queue_put(&queue, commit);
}
/*
* This is unfortunate; the initial tips need to be shown
* in the order given from the revision traversal machinery.
*/
if (sort_order == REV_SORT_IN_GRAPH_ORDER)
prio_queue_reverse(&queue);
/* We no longer need the commit list */
free_commit_list(orig);
pptr = list;
*list = NULL;
while ((commit = prio_queue_get(&queue)) != NULL) {
struct commit_list *parents;
for (parents = commit->parents; parents ; parents = parents->next) {
struct commit *parent = parents->item;
int *pi = indegree_slab_at(&indegree, parent);
if (!*pi)
continue;
/*
* parents are only enqueued for emission
* when all their children have been emitted thereby
* guaranteeing topological order.
*/
if (--(*pi) == 1)
prio_queue_put(&queue, parent);
}
/*
* all children of commit have already been
* emitted. we can emit it now.
*/
*(indegree_slab_at(&indegree, commit)) = 0;
pptr = &commit_list_insert(commit, pptr)->next;
}
clear_indegree_slab(&indegree);
clear_prio_queue(&queue);
if (sort_order == REV_SORT_BY_AUTHOR_DATE)
clear_author_date_slab(&author_date);
}
struct rev_collect {
struct commit **commit;
int nr;
int alloc;
unsigned int initial : 1;
};
static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
{
struct commit *commit;
if (is_null_oid(oid))
return;
commit = lookup_commit(the_repository, oid);
if (!commit ||
(commit->object.flags & TMP_MARK) ||
parse_commit(commit))
return;
ALLOC_GROW(revs->commit, revs->nr + 1, revs->alloc);
revs->commit[revs->nr++] = commit;
commit->object.flags |= TMP_MARK;
}
static int collect_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
const char *ident, timestamp_t timestamp,
int tz, const char *message, void *cbdata)
{
struct rev_collect *revs = cbdata;
if (revs->initial) {
revs->initial = 0;
add_one_commit(ooid, revs);
}
add_one_commit(noid, revs);
return 0;
}
struct commit *get_fork_point(const char *refname, struct commit *commit)
{
struct object_id oid;
struct rev_collect revs;
struct commit_list *bases;
int i;
struct commit *ret = NULL;
memset(&revs, 0, sizeof(revs));
revs.initial = 1;
for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
if (!revs.nr && !get_oid(refname, &oid))
add_one_commit(&oid, &revs);
for (i = 0; i < revs.nr; i++)
revs.commit[i]->object.flags &= ~TMP_MARK;
bases = get_merge_bases_many(commit, revs.nr, revs.commit);
/*
* There should be one and only one merge base, when we found
* a common ancestor among reflog entries.
*/
if (!bases || bases->next)
goto cleanup_return;
/* And the found one must be one of the reflog entries */
for (i = 0; i < revs.nr; i++)
if (&bases->item->object == &revs.commit[i]->object)
break; /* found */
if (revs.nr <= i)
goto cleanup_return;
ret = bases->item;
cleanup_return:
free_commit_list(bases);
return ret;
}
static const char gpg_sig_header[] = "gpgsig";
static const int gpg_sig_header_len = sizeof(gpg_sig_header) - 1;
static int do_sign_commit(struct strbuf *buf, const char *keyid)
{
struct strbuf sig = STRBUF_INIT;
int inspos, copypos;
const char *eoh;
/* find the end of the header */
eoh = strstr(buf->buf, "\n\n");
if (!eoh)
inspos = buf->len;
else
inspos = eoh - buf->buf + 1;
if (!keyid || !*keyid)
keyid = get_signing_key();
if (sign_buffer(buf, &sig, keyid)) {
strbuf_release(&sig);
return -1;
}
for (copypos = 0; sig.buf[copypos]; ) {
const char *bol = sig.buf + copypos;
const char *eol = strchrnul(bol, '\n');
int len = (eol - bol) + !!*eol;
if (!copypos) {
strbuf_insert(buf, inspos, gpg_sig_header, gpg_sig_header_len);
inspos += gpg_sig_header_len;
}
strbuf_insert(buf, inspos++, " ", 1);
strbuf_insert(buf, inspos, bol, len);
inspos += len;
copypos += len;
}
strbuf_release(&sig);
return 0;
}
int parse_signed_commit(const struct commit *commit,
struct strbuf *payload, struct strbuf *signature)
{
unsigned long size;
const char *buffer = get_commit_buffer(commit, &size);
int in_signature, saw_signature = -1;
const char *line, *tail;
line = buffer;
tail = buffer + size;
in_signature = 0;
saw_signature = 0;
while (line < tail) {
const char *sig = NULL;
const char *next = memchr(line, '\n', tail - line);
next = next ? next + 1 : tail;
if (in_signature && line[0] == ' ')
sig = line + 1;
else if (starts_with(line, gpg_sig_header) &&
line[gpg_sig_header_len] == ' ')
sig = line + gpg_sig_header_len + 1;
if (sig) {
strbuf_add(signature, sig, next - sig);
saw_signature = 1;
in_signature = 1;
} else {
if (*line == '\n')
/* dump the whole remainder of the buffer */
next = tail;
strbuf_add(payload, line, next - line);
in_signature = 0;
}
line = next;
}
unuse_commit_buffer(commit, buffer);
return saw_signature;
}
int remove_signature(struct strbuf *buf)
{
const char *line = buf->buf;
const char *tail = buf->buf + buf->len;
int in_signature = 0;
const char *sig_start = NULL;
const char *sig_end = NULL;
while (line < tail) {
const char *next = memchr(line, '\n', tail - line);
next = next ? next + 1 : tail;
if (in_signature && line[0] == ' ')
sig_end = next;
else if (starts_with(line, gpg_sig_header) &&
line[gpg_sig_header_len] == ' ') {
sig_start = line;
sig_end = next;
in_signature = 1;
} else {
if (*line == '\n')
/* dump the whole remainder of the buffer */
next = tail;
in_signature = 0;
}
line = next;
}
if (sig_start)
strbuf_remove(buf, sig_start - buf->buf, sig_end - sig_start);
return sig_start != NULL;
}
static void handle_signed_tag(struct commit *parent, struct commit_extra_header ***tail)
{
struct merge_remote_desc *desc;
struct commit_extra_header *mergetag;
char *buf;
unsigned long size, len;
enum object_type type;
desc = merge_remote_util(parent);
if (!desc || !desc->obj)
return;
buf = read_object_file(&desc->obj->oid, &type, &size);
if (!buf || type != OBJ_TAG)
goto free_return;
len = parse_signature(buf, size);
if (size == len)
goto free_return;
/*
* We could verify this signature and either omit the tag when
* it does not validate, but the integrator may not have the
* public key of the signer of the tag he is merging, while a
* later auditor may have it while auditing, so let's not run
* verify-signed-buffer here for now...
*
* if (verify_signed_buffer(buf, len, buf + len, size - len, ...))
* warn("warning: signed tag unverified.");
*/
mergetag = xcalloc(1, sizeof(*mergetag));
mergetag->key = xstrdup("mergetag");
mergetag->value = buf;
mergetag->len = size;
**tail = mergetag;
*tail = &mergetag->next;
return;
free_return:
free(buf);
}
int check_commit_signature(const struct commit *commit, struct signature_check *sigc)
{
struct strbuf payload = STRBUF_INIT;
struct strbuf signature = STRBUF_INIT;
int ret = 1;
sigc->result = 'N';
if (parse_signed_commit(commit, &payload, &signature) <= 0)
goto out;
ret = check_signature(payload.buf, payload.len, signature.buf,
signature.len, sigc);
out:
strbuf_release(&payload);
strbuf_release(&signature);
return ret;
}
void verify_merge_signature(struct commit *commit, int verbosity)
{
char hex[GIT_MAX_HEXSZ + 1];
struct signature_check signature_check;
memset(&signature_check, 0, sizeof(signature_check));
check_commit_signature(commit, &signature_check);
find_unique_abbrev_r(hex, &commit->object.oid, DEFAULT_ABBREV);
switch (signature_check.result) {
case 'G':
break;
case 'U':
die(_("Commit %s has an untrusted GPG signature, "
"allegedly by %s."), hex, signature_check.signer);
case 'B':
die(_("Commit %s has a bad GPG signature "
"allegedly by %s."), hex, signature_check.signer);
default: /* 'N' */
die(_("Commit %s does not have a GPG signature."), hex);
}
if (verbosity >= 0 && signature_check.result == 'G')
printf(_("Commit %s has a good GPG signature by %s\n"),
hex, signature_check.signer);
signature_check_clear(&signature_check);
}
void append_merge_tag_headers(struct commit_list *parents,
struct commit_extra_header ***tail)
{
while (parents) {
struct commit *parent = parents->item;
handle_signed_tag(parent, tail);
parents = parents->next;
}
}
static void add_extra_header(struct strbuf *buffer,
struct commit_extra_header *extra)
{
strbuf_addstr(buffer, extra->key);
if (extra->len)
strbuf_add_lines(buffer, " ", extra->value, extra->len);
else
strbuf_addch(buffer, '\n');
}
struct commit_extra_header *read_commit_extra_headers(struct commit *commit,
const char **exclude)
{
struct commit_extra_header *extra = NULL;
unsigned long size;
const char *buffer = get_commit_buffer(commit, &size);
extra = read_commit_extra_header_lines(buffer, size, exclude);
unuse_commit_buffer(commit, buffer);
return extra;
}
int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data)
{
struct commit_extra_header *extra, *to_free;
int res = 0;
to_free = read_commit_extra_headers(commit, NULL);
for (extra = to_free; !res && extra; extra = extra->next) {
if (strcmp(extra->key, "mergetag"))
continue; /* not a merge tag */
res = fn(commit, extra, data);
}
free_commit_extra_headers(to_free);
return res;
}
static inline int standard_header_field(const char *field, size_t len)
{
return ((len == 4 && !memcmp(field, "tree", 4)) ||
(len == 6 && !memcmp(field, "parent", 6)) ||
(len == 6 && !memcmp(field, "author", 6)) ||
(len == 9 && !memcmp(field, "committer", 9)) ||
(len == 8 && !memcmp(field, "encoding", 8)));
}
static int excluded_header_field(const char *field, size_t len, const char **exclude)
{
if (!exclude)
return 0;
while (*exclude) {
size_t xlen = strlen(*exclude);
if (len == xlen && !memcmp(field, *exclude, xlen))
return 1;
exclude++;
}
return 0;
}
static struct commit_extra_header *read_commit_extra_header_lines(
const char *buffer, size_t size,
const char **exclude)
{
struct commit_extra_header *extra = NULL, **tail = &extra, *it = NULL;
const char *line, *next, *eof, *eob;
struct strbuf buf = STRBUF_INIT;
for (line = buffer, eob = line + size;
line < eob && *line != '\n';
line = next) {
next = memchr(line, '\n', eob - line);
next = next ? next + 1 : eob;
if (*line == ' ') {
/* continuation */
if (it)
strbuf_add(&buf, line + 1, next - (line + 1));
continue;
}
if (it)
it->value = strbuf_detach(&buf, &it->len);
strbuf_reset(&buf);
it = NULL;
eof = memchr(line, ' ', next - line);
if (!eof)
eof = next;
else if (standard_header_field(line, eof - line) ||
excluded_header_field(line, eof - line, exclude))
continue;
it = xcalloc(1, sizeof(*it));
it->key = xmemdupz(line, eof-line);
*tail = it;
tail = &it->next;
if (eof + 1 < next)
strbuf_add(&buf, eof + 1, next - (eof + 1));
}
if (it)
it->value = strbuf_detach(&buf, &it->len);
return extra;
}
void free_commit_extra_headers(struct commit_extra_header *extra)
{
while (extra) {
struct commit_extra_header *next = extra->next;
free(extra->key);
free(extra->value);
free(extra);
extra = next;
}
}
int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
struct commit_list *parents, struct object_id *ret,
const char *author, const char *sign_commit)
{
struct commit_extra_header *extra = NULL, **tail = &extra;
int result;
append_merge_tag_headers(parents, &tail);
result = commit_tree_extended(msg, msg_len, tree, parents, ret,
author, sign_commit, extra);
free_commit_extra_headers(extra);
return result;
}
static int find_invalid_utf8(const char *buf, int len)
{
int offset = 0;
static const unsigned int max_codepoint[] = {
0x7f, 0x7ff, 0xffff, 0x10ffff
};
while (len) {
unsigned char c = *buf++;
int bytes, bad_offset;
unsigned int codepoint;
unsigned int min_val, max_val;
len--;
offset++;
/* Simple US-ASCII? No worries. */
if (c < 0x80)
continue;
bad_offset = offset-1;
/*
* Count how many more high bits set: that's how
* many more bytes this sequence should have.
*/
bytes = 0;
while (c & 0x40) {
c <<= 1;
bytes++;
}
/*
* Must be between 1 and 3 more bytes. Longer sequences result in
* codepoints beyond U+10FFFF, which are guaranteed never to exist.
*/
if (bytes < 1 || 3 < bytes)
return bad_offset;
/* Do we *have* that many bytes? */
if (len < bytes)
return bad_offset;
/*
* Place the encoded bits at the bottom of the value and compute the
* valid range.
*/
codepoint = (c & 0x7f) >> bytes;
min_val = max_codepoint[bytes-1] + 1;
max_val = max_codepoint[bytes];
offset += bytes;
len -= bytes;
/* And verify that they are good continuation bytes */
do {
codepoint <<= 6;
codepoint |= *buf & 0x3f;
if ((*buf++ & 0xc0) != 0x80)
return bad_offset;
} while (--bytes);
/* Reject codepoints that are out of range for the sequence length. */
if (codepoint < min_val || codepoint > max_val)
return bad_offset;
/* Surrogates are only for UTF-16 and cannot be encoded in UTF-8. */
if ((codepoint & 0x1ff800) == 0xd800)
return bad_offset;
/* U+xxFFFE and U+xxFFFF are guaranteed non-characters. */
if ((codepoint & 0xfffe) == 0xfffe)
return bad_offset;
/* So are anything in the range U+FDD0..U+FDEF. */
if (codepoint >= 0xfdd0 && codepoint <= 0xfdef)
return bad_offset;
}
return -1;
}
/*
* This verifies that the buffer is in proper utf8 format.
*
* If it isn't, it assumes any non-utf8 characters are Latin1,
* and does the conversion.
*/
static int verify_utf8(struct strbuf *buf)
{
int ok = 1;
long pos = 0;
for (;;) {
int bad;
unsigned char c;
unsigned char replace[2];
bad = find_invalid_utf8(buf->buf + pos, buf->len - pos);
if (bad < 0)
return ok;
pos += bad;
ok = 0;
c = buf->buf[pos];
strbuf_remove(buf, pos, 1);
/* We know 'c' must be in the range 128-255 */
replace[0] = 0xc0 + (c >> 6);
replace[1] = 0x80 + (c & 0x3f);
strbuf_insert(buf, pos, replace, 2);
pos += 2;
}
}
static const char commit_utf8_warn[] =
N_("Warning: commit message did not conform to UTF-8.\n"
"You may want to amend it after fixing the message, or set the config\n"
"variable i18n.commitencoding to the encoding your project uses.\n");
int commit_tree_extended(const char *msg, size_t msg_len,
const struct object_id *tree,
struct commit_list *parents, struct object_id *ret,
const char *author, const char *sign_commit,
struct commit_extra_header *extra)
{
int result;
int encoding_is_utf8;
struct strbuf buffer;
assert_oid_type(tree, OBJ_TREE);
if (memchr(msg, '\0', msg_len))
return error("a NUL byte in commit log message not allowed.");
/* Not having i18n.commitencoding is the same as having utf-8 */
encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
strbuf_init(&buffer, 8192); /* should avoid reallocs for the headers */
strbuf_addf(&buffer, "tree %s\n", oid_to_hex(tree));
/*
* NOTE! This ordering means that the same exact tree merged with a
* different order of parents will be a _different_ changeset even
* if everything else stays the same.
*/
while (parents) {
struct commit *parent = pop_commit(&parents);
strbuf_addf(&buffer, "parent %s\n",
oid_to_hex(&parent->object.oid));
}
/* Person/date information */
if (!author)
author = git_author_info(IDENT_STRICT);
strbuf_addf(&buffer, "author %s\n", author);
strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
if (!encoding_is_utf8)
strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
while (extra) {
add_extra_header(&buffer, extra);
extra = extra->next;
}
strbuf_addch(&buffer, '\n');
/* And add the comment */
strbuf_add(&buffer, msg, msg_len);
/* And check the encoding */
if (encoding_is_utf8 && !verify_utf8(&buffer))
fprintf(stderr, _(commit_utf8_warn));
if (sign_commit && do_sign_commit(&buffer, sign_commit)) {
result = -1;
goto out;
}
result = write_object_file(buffer.buf, buffer.len, commit_type, ret);
out:
strbuf_release(&buffer);
return result;
}
define_commit_slab(merge_desc_slab, struct merge_remote_desc *);
static struct merge_desc_slab merge_desc_slab = COMMIT_SLAB_INIT(1, merge_desc_slab);
struct merge_remote_desc *merge_remote_util(struct commit *commit)
{
return *merge_desc_slab_at(&merge_desc_slab, commit);
}
void set_merge_remote_desc(struct commit *commit,
const char *name, struct object *obj)
{
struct merge_remote_desc *desc;
FLEX_ALLOC_STR(desc, name, name);
desc->obj = obj;
*merge_desc_slab_at(&merge_desc_slab, commit) = desc;
}
struct commit *get_merge_parent(const char *name)
{
struct object *obj;
struct commit *commit;
struct object_id oid;
if (get_oid(name, &oid))
return NULL;
obj = parse_object(the_repository, &oid);
commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
if (commit && !merge_remote_util(commit))
set_merge_remote_desc(commit, name, obj);
return commit;
}
/*
* Append a commit to the end of the commit_list.
*
* next starts by pointing to the variable that holds the head of an
* empty commit_list, and is updated to point to the "next" field of
* the last item on the list as new commits are appended.
*
* Usage example:
*
* struct commit_list *list;
* struct commit_list **next = &list;
*
* next = commit_list_append(c1, next);
* next = commit_list_append(c2, next);
* assert(commit_list_count(list) == 2);
* return list;
*/
struct commit_list **commit_list_append(struct commit *commit,
struct commit_list **next)
{
struct commit_list *new_commit = xmalloc(sizeof(struct commit_list));
new_commit->item = commit;
*next = new_commit;
new_commit->next = NULL;
return &new_commit->next;
}
const char *find_commit_header(const char *msg, const char *key, size_t *out_len)
{
int key_len = strlen(key);
const char *line = msg;
while (line) {
const char *eol = strchrnul(line, '\n');
if (line == eol)
return NULL;
if (eol - line > key_len &&
!strncmp(line, key, key_len) &&
line[key_len] == ' ') {
*out_len = eol - line - key_len - 1;
return line + key_len + 1;
}
line = *eol ? eol + 1 : NULL;
}
return NULL;
}
/*
* Inspect the given string and determine the true "end" of the log message, in
* order to find where to put a new Signed-off-by: line. Ignored are
* trailing comment lines and blank lines. To support "git commit -s
* --amend" on an existing commit, we also ignore "Conflicts:". To
* support "git commit -v", we truncate at cut lines.
*
* Returns the number of bytes from the tail to ignore, to be fed as
* the second parameter to append_signoff().
*/
size_t ignore_non_trailer(const char *buf, size_t len)
{
size_t boc = 0;
size_t bol = 0;
int in_old_conflicts_block = 0;
size_t cutoff = wt_status_locate_end(buf, len);
while (bol < cutoff) {
const char *next_line = memchr(buf + bol, '\n', len - bol);
if (!next_line)
next_line = buf + len;
else
next_line++;
if (buf[bol] == comment_line_char || buf[bol] == '\n') {
/* is this the first of the run of comments? */
if (!boc)
boc = bol;
/* otherwise, it is just continuing */
} else if (starts_with(buf + bol, "Conflicts:\n")) {
in_old_conflicts_block = 1;
if (!boc)
boc = bol;
} else if (in_old_conflicts_block && buf[bol] == '\t') {
; /* a pathname in the conflicts block */
} else if (boc) {
/* the previous was not trailing comment */
boc = 0;
in_old_conflicts_block = 0;
}
bol = next_line - buf;
}
return boc ? len - boc : len - cutoff;
}