git/commit.c
Junio C Hamano 08f704f294 toposort: rename "lifo" field
The primary invariant of sort_in_topological_order() is that a
parent commit is not emitted until all children of it are.  When
traversing a forked history like this with "git log C E":

    A----B----C
     \
      D----E

we ensure that A is emitted after all of B, C, D, and E are done, B
has to wait until C is done, and D has to wait until E is done.

In some applications, however, we would further want to control how
these child commits B, C, D and E on two parallel ancestry chains
are shown.

Most of the time, we would want to see C and B emitted together, and
then E and D, and finally A (i.e. the --topo-order output).  The
"lifo" parameter of the sort_in_topological_order() function is used
to control this behaviour.  We start the traversal by knowing two
commits, C and E.  While keeping in mind that we also need to
inspect E later, we pick C first to inspect, and we notice and
record that B needs to be inspected.  By structuring the "work to be
done" set as a LIFO stack, we ensure that B is inspected next,
before other in-flight commits we had known that we will need to
inspect, e.g. E.

When showing in --date-order, we would want to see commits ordered
by timestamps, i.e. show C, E, B and D in this order before showing
A, possibly mixing commits from two parallel histories together.
When "lifo" parameter is set to false, the function keeps the "work
to be done" set sorted in the date order to realize this semantics.
After inspecting C, we add B to the "work to be done" set, but the
next commit we inspect from the set is E which is newer than B.

The name "lifo", however, is too strongly tied to the way how the
function implements its behaviour, and does not describe what the
behaviour _means_.

Replace this field with an enum rev_sort_order, with two possible
values: REV_SORT_IN_GRAPH_ORDER and REV_SORT_BY_COMMIT_DATE, and
update the existing code.  The mechanical replacement rule is:

  "lifo == 0" is equivalent to "sort_order == REV_SORT_BY_COMMIT_DATE"
  "lifo == 1" is equivalent to "sort_order == REV_SORT_IN_GRAPH_ORDER"

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-11 15:15:21 -07:00

1383 lines
32 KiB
C

#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "pkt-line.h"
#include "utf8.h"
#include "diff.h"
#include "revision.h"
#include "notes.h"
#include "gpg-interface.h"
#include "mergesort.h"
#include "commit-slab.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";
static int commit_count;
static struct commit *check_commit(struct object *obj,
const unsigned char *sha1,
int quiet)
{
if (obj->type != OBJ_COMMIT) {
if (!quiet)
error("Object %s is a %s, not a commit",
sha1_to_hex(sha1), typename(obj->type));
return NULL;
}
return (struct commit *) obj;
}
struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
int quiet)
{
struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
if (!obj)
return NULL;
return check_commit(obj, sha1, quiet);
}
struct commit *lookup_commit_reference(const unsigned char *sha1)
{
return lookup_commit_reference_gently(sha1, 0);
}
struct commit *lookup_commit_or_die(const unsigned char *sha1, const char *ref_name)
{
struct commit *c = lookup_commit_reference(sha1);
if (!c)
die(_("could not parse %s"), ref_name);
if (hashcmp(sha1, c->object.sha1)) {
warning(_("%s %s is not a commit!"),
ref_name, sha1_to_hex(sha1));
}
return c;
}
struct commit *lookup_commit(const unsigned char *sha1)
{
struct object *obj = lookup_object(sha1);
if (!obj) {
struct commit *c = alloc_commit_node();
c->index = commit_count++;
return create_object(sha1, OBJ_COMMIT, c);
}
if (!obj->type)
obj->type = OBJ_COMMIT;
return check_commit(obj, sha1, 0);
}
struct commit *lookup_commit_reference_by_name(const char *name)
{
unsigned char sha1[20];
struct commit *commit;
if (get_sha1_committish(name, sha1))
return NULL;
commit = lookup_commit_reference(sha1);
if (!commit || parse_commit(commit))
return NULL;
return commit;
}
static unsigned long 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 strtoul will stop at buf-1 */
return strtoul(dateptr, NULL, 10);
}
static struct commit_graft **commit_graft;
static int commit_graft_alloc, commit_graft_nr;
static int commit_graft_pos(const unsigned char *sha1)
{
int lo, hi;
lo = 0;
hi = commit_graft_nr;
while (lo < hi) {
int mi = (lo + hi) / 2;
struct commit_graft *graft = commit_graft[mi];
int cmp = hashcmp(sha1, graft->sha1);
if (!cmp)
return mi;
if (cmp < 0)
hi = mi;
else
lo = mi + 1;
}
return -lo - 1;
}
int register_commit_graft(struct commit_graft *graft, int ignore_dups)
{
int pos = commit_graft_pos(graft->sha1);
if (0 <= pos) {
if (ignore_dups)
free(graft);
else {
free(commit_graft[pos]);
commit_graft[pos] = graft;
}
return 1;
}
pos = -pos - 1;
if (commit_graft_alloc <= ++commit_graft_nr) {
commit_graft_alloc = alloc_nr(commit_graft_alloc);
commit_graft = xrealloc(commit_graft,
sizeof(*commit_graft) *
commit_graft_alloc);
}
if (pos < commit_graft_nr)
memmove(commit_graft + pos + 1,
commit_graft + pos,
(commit_graft_nr - pos - 1) *
sizeof(*commit_graft));
commit_graft[pos] = graft;
return 0;
}
struct commit_graft *read_graft_line(char *buf, int len)
{
/* The format is just "Commit Parent1 Parent2 ...\n" */
int i;
struct commit_graft *graft = NULL;
while (len && isspace(buf[len-1]))
buf[--len] = '\0';
if (buf[0] == '#' || buf[0] == '\0')
return NULL;
if ((len + 1) % 41)
goto bad_graft_data;
i = (len + 1) / 41 - 1;
graft = xmalloc(sizeof(*graft) + 20 * i);
graft->nr_parent = i;
if (get_sha1_hex(buf, graft->sha1))
goto bad_graft_data;
for (i = 40; i < len; i += 41) {
if (buf[i] != ' ')
goto bad_graft_data;
if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
goto bad_graft_data;
}
return graft;
bad_graft_data:
error("bad graft data: %s", buf);
free(graft);
return NULL;
}
static int read_graft_file(const char *graft_file)
{
FILE *fp = fopen(graft_file, "r");
char buf[1024];
if (!fp)
return -1;
while (fgets(buf, sizeof(buf), fp)) {
/* The format is just "Commit Parent1 Parent2 ...\n" */
int len = strlen(buf);
struct commit_graft *graft = read_graft_line(buf, len);
if (!graft)
continue;
if (register_commit_graft(graft, 1))
error("duplicate graft data: %s", buf);
}
fclose(fp);
return 0;
}
static void prepare_commit_graft(void)
{
static int commit_graft_prepared;
char *graft_file;
if (commit_graft_prepared)
return;
graft_file = get_graft_file();
read_graft_file(graft_file);
/* make sure shallows are read */
is_repository_shallow();
commit_graft_prepared = 1;
}
struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
{
int pos;
prepare_commit_graft();
pos = commit_graft_pos(sha1);
if (pos < 0)
return NULL;
return commit_graft[pos];
}
int for_each_commit_graft(each_commit_graft_fn fn, void *cb_data)
{
int i, ret;
for (i = ret = 0; i < commit_graft_nr && !ret; i++)
ret = fn(commit_graft[i], cb_data);
return ret;
}
int unregister_shallow(const unsigned char *sha1)
{
int pos = commit_graft_pos(sha1);
if (pos < 0)
return -1;
if (pos + 1 < commit_graft_nr)
memmove(commit_graft + pos, commit_graft + pos + 1,
sizeof(struct commit_graft *)
* (commit_graft_nr - pos - 1));
commit_graft_nr--;
return 0;
}
int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size)
{
const char *tail = buffer;
const char *bufptr = buffer;
unsigned char parent[20];
struct commit_list **pptr;
struct commit_graft *graft;
if (item->object.parsed)
return 0;
item->object.parsed = 1;
tail += size;
if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
if (get_sha1_hex(bufptr + 5, parent) < 0)
return error("bad tree pointer in commit %s",
sha1_to_hex(item->object.sha1));
item->tree = lookup_tree(parent);
bufptr += 46; /* "tree " + "hex sha1" + "\n" */
pptr = &item->parents;
graft = lookup_commit_graft(item->object.sha1);
while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
struct commit *new_parent;
if (tail <= bufptr + 48 ||
get_sha1_hex(bufptr + 7, parent) ||
bufptr[47] != '\n')
return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
bufptr += 48;
/*
* 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(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(graft->parent[i]);
if (!new_parent)
continue;
pptr = &commit_list_insert(new_parent, pptr)->next;
}
}
item->date = parse_commit_date(bufptr, tail);
return 0;
}
int parse_commit(struct commit *item)
{
enum object_type type;
void *buffer;
unsigned long size;
int ret;
if (!item)
return -1;
if (item->object.parsed)
return 0;
buffer = read_sha1_file(item->object.sha1, &type, &size);
if (!buffer)
return error("Could not read %s",
sha1_to_hex(item->object.sha1));
if (type != OBJ_COMMIT) {
free(buffer);
return error("Object %s not a commit",
sha1_to_hex(item->object.sha1));
}
ret = parse_commit_buffer(item, buffer, size);
if (save_commit_buffer && !ret) {
item->buffer = buffer;
return 0;
}
free(buffer);
return ret;
}
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 += 2;
for (eol = p; *eol && *eol != '\n'; eol++)
; /* do nothing */
} 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;
}
void free_commit_list(struct commit_list *list)
{
while (list) {
struct commit_list *temp = list;
list = temp->next;
free(temp);
}
}
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)
{
unsigned long a_date = ((const struct commit_list *)a)->item->date;
unsigned long 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 = (*list)->item;
struct commit_list *parents = ret->parents;
struct commit_list *old = *list;
*list = (*list)->next;
free(old);
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(struct commit *commit, unsigned int mark)
{
struct commit_list *list = NULL;
commit_list_insert(commit, &list);
while (list)
clear_commit_marks_1(&list, pop_commit(&list), mark);
}
void clear_commit_marks_for_object_array(struct object_array *a, unsigned mark)
{
struct object *object;
struct commit *commit;
unsigned int i;
for (i = 0; i < a->nr; i++) {
object = a->objects[i].item;
commit = lookup_commit_reference_gently(object->sha1, 1);
if (commit)
clear_commit_marks(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);
/*
* 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 *work, **insert;
struct commit_list **pptr;
struct indegree_slab indegree;
if (!orig)
return;
*list = NULL;
init_indegree_slab(&indegree);
/* Mark them and clear the indegree */
for (next = orig; next; next = next->next) {
struct commit *commit = next->item;
*(indegree_slab_at(&indegree, commit)) = 1;
}
/* 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.
*/
work = NULL;
insert = &work;
for (next = orig; next; next = next->next) {
struct commit *commit = next->item;
if (*(indegree_slab_at(&indegree, commit)) == 1)
insert = &commit_list_insert(commit, insert)->next;
}
/* process the list in topological order */
if (sort_order != REV_SORT_IN_GRAPH_ORDER)
commit_list_sort_by_date(&work);
pptr = list;
*list = NULL;
while (work) {
struct commit *commit;
struct commit_list *parents, *work_item;
work_item = work;
work = work_item->next;
work_item->next = NULL;
commit = work_item->item;
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) {
switch (sort_order) {
case REV_SORT_BY_COMMIT_DATE:
commit_list_insert_by_date(parent, &work);
break;
default: /* REV_SORT_IN_GRAPH_ORDER */
commit_list_insert(parent, &work);
break;
}
}
}
/*
* work_item is a commit all of whose children
* have already been emitted. we can emit it now.
*/
*(indegree_slab_at(&indegree, commit)) = 0;
*pptr = work_item;
pptr = &work_item->next;
}
clear_indegree_slab(&indegree);
}
/* merge-base stuff */
/* bits #0..15 in revision.h */
#define PARENT1 (1u<<16)
#define PARENT2 (1u<<17)
#define STALE (1u<<18)
#define RESULT (1u<<19)
static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);
static struct commit *interesting(struct commit_list *list)
{
while (list) {
struct commit *commit = list->item;
list = list->next;
if (commit->object.flags & STALE)
continue;
return commit;
}
return NULL;
}
/* all input commits in one and twos[] must have been parsed! */
static struct commit_list *paint_down_to_common(struct commit *one, int n, struct commit **twos)
{
struct commit_list *list = NULL;
struct commit_list *result = NULL;
int i;
one->object.flags |= PARENT1;
commit_list_insert_by_date(one, &list);
if (!n)
return list;
for (i = 0; i < n; i++) {
twos[i]->object.flags |= PARENT2;
commit_list_insert_by_date(twos[i], &list);
}
while (interesting(list)) {
struct commit *commit;
struct commit_list *parents;
struct commit_list *next;
int flags;
commit = list->item;
next = list->next;
free(list);
list = next;
flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
if (flags == (PARENT1 | PARENT2)) {
if (!(commit->object.flags & RESULT)) {
commit->object.flags |= RESULT;
commit_list_insert_by_date(commit, &result);
}
/* Mark parents of a found merge stale */
flags |= STALE;
}
parents = commit->parents;
while (parents) {
struct commit *p = parents->item;
parents = parents->next;
if ((p->object.flags & flags) == flags)
continue;
if (parse_commit(p))
return NULL;
p->object.flags |= flags;
commit_list_insert_by_date(p, &list);
}
}
free_commit_list(list);
return result;
}
static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
{
struct commit_list *list = NULL;
struct commit_list *result = NULL;
int i;
for (i = 0; i < n; i++) {
if (one == twos[i])
/*
* We do not mark this even with RESULT so we do not
* have to clean it up.
*/
return commit_list_insert(one, &result);
}
if (parse_commit(one))
return NULL;
for (i = 0; i < n; i++) {
if (parse_commit(twos[i]))
return NULL;
}
list = paint_down_to_common(one, n, twos);
while (list) {
struct commit_list *next = list->next;
if (!(list->item->object.flags & STALE))
commit_list_insert_by_date(list->item, &result);
free(list);
list = next;
}
return result;
}
struct commit_list *get_octopus_merge_bases(struct commit_list *in)
{
struct commit_list *i, *j, *k, *ret = NULL;
struct commit_list **pptr = &ret;
for (i = in; i; i = i->next) {
if (!ret)
pptr = &commit_list_insert(i->item, pptr)->next;
else {
struct commit_list *new = NULL, *end = NULL;
for (j = ret; j; j = j->next) {
struct commit_list *bases;
bases = get_merge_bases(i->item, j->item, 1);
if (!new)
new = bases;
else
end->next = bases;
for (k = bases; k; k = k->next)
end = k;
}
ret = new;
}
}
return ret;
}
static int remove_redundant(struct commit **array, int cnt)
{
/*
* Some commit in the array may be an ancestor of
* another commit. Move such commit to the end of
* the array, and return the number of commits that
* are independent from each other.
*/
struct commit **work;
unsigned char *redundant;
int *filled_index;
int i, j, filled;
work = xcalloc(cnt, sizeof(*work));
redundant = xcalloc(cnt, 1);
filled_index = xmalloc(sizeof(*filled_index) * (cnt - 1));
for (i = 0; i < cnt; i++)
parse_commit(array[i]);
for (i = 0; i < cnt; i++) {
struct commit_list *common;
if (redundant[i])
continue;
for (j = filled = 0; j < cnt; j++) {
if (i == j || redundant[j])
continue;
filled_index[filled] = j;
work[filled++] = array[j];
}
common = paint_down_to_common(array[i], filled, work);
if (array[i]->object.flags & PARENT2)
redundant[i] = 1;
for (j = 0; j < filled; j++)
if (work[j]->object.flags & PARENT1)
redundant[filled_index[j]] = 1;
clear_commit_marks(array[i], all_flags);
for (j = 0; j < filled; j++)
clear_commit_marks(work[j], all_flags);
free_commit_list(common);
}
/* Now collect the result */
memcpy(work, array, sizeof(*array) * cnt);
for (i = filled = 0; i < cnt; i++)
if (!redundant[i])
array[filled++] = work[i];
for (j = filled, i = 0; i < cnt; i++)
if (redundant[i])
array[j++] = work[i];
free(work);
free(redundant);
free(filled_index);
return filled;
}
struct commit_list *get_merge_bases_many(struct commit *one,
int n,
struct commit **twos,
int cleanup)
{
struct commit_list *list;
struct commit **rslt;
struct commit_list *result;
int cnt, i;
result = merge_bases_many(one, n, twos);
for (i = 0; i < n; i++) {
if (one == twos[i])
return result;
}
if (!result || !result->next) {
if (cleanup) {
clear_commit_marks(one, all_flags);
for (i = 0; i < n; i++)
clear_commit_marks(twos[i], all_flags);
}
return result;
}
/* There are more than one */
cnt = 0;
list = result;
while (list) {
list = list->next;
cnt++;
}
rslt = xcalloc(cnt, sizeof(*rslt));
for (list = result, i = 0; list; list = list->next)
rslt[i++] = list->item;
free_commit_list(result);
clear_commit_marks(one, all_flags);
for (i = 0; i < n; i++)
clear_commit_marks(twos[i], all_flags);
cnt = remove_redundant(rslt, cnt);
result = NULL;
for (i = 0; i < cnt; i++)
commit_list_insert_by_date(rslt[i], &result);
free(rslt);
return result;
}
struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
int cleanup)
{
return get_merge_bases_many(one, 1, &two, cleanup);
}
/*
* Is "commit" a descendant of one of the elements on the "with_commit" list?
*/
int is_descendant_of(struct commit *commit, struct commit_list *with_commit)
{
if (!with_commit)
return 1;
while (with_commit) {
struct commit *other;
other = with_commit->item;
with_commit = with_commit->next;
if (in_merge_bases(other, commit))
return 1;
}
return 0;
}
/*
* Is "commit" an ancestor of (i.e. reachable from) the "reference"?
*/
int in_merge_bases(struct commit *commit, struct commit *reference)
{
struct commit_list *bases;
int ret = 0;
if (parse_commit(commit) || parse_commit(reference))
return ret;
bases = paint_down_to_common(commit, 1, &reference);
if (commit->object.flags & PARENT2)
ret = 1;
clear_commit_marks(commit, all_flags);
clear_commit_marks(reference, all_flags);
free_commit_list(bases);
return ret;
}
struct commit_list *reduce_heads(struct commit_list *heads)
{
struct commit_list *p;
struct commit_list *result = NULL, **tail = &result;
struct commit **array;
int num_head, i;
if (!heads)
return NULL;
/* Uniquify */
for (p = heads; p; p = p->next)
p->item->object.flags &= ~STALE;
for (p = heads, num_head = 0; p; p = p->next) {
if (p->item->object.flags & STALE)
continue;
p->item->object.flags |= STALE;
num_head++;
}
array = xcalloc(sizeof(*array), num_head);
for (p = heads, i = 0; p; p = p->next) {
if (p->item->object.flags & STALE) {
array[i++] = p->item;
p->item->object.flags &= ~STALE;
}
}
num_head = remove_redundant(array, num_head);
for (i = 0; i < num_head; i++)
tail = &commit_list_insert(array[i], tail)->next;
return result;
}
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;
/* find the end of the header */
inspos = strstr(buf->buf, "\n\n") - 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 unsigned char *sha1,
struct strbuf *payload, struct strbuf *signature)
{
unsigned long size;
enum object_type type;
char *buffer = read_sha1_file(sha1, &type, &size);
int in_signature, saw_signature = -1;
char *line, *tail;
if (!buffer || type != OBJ_COMMIT)
goto cleanup;
line = buffer;
tail = buffer + size;
in_signature = 0;
saw_signature = 0;
while (line < tail) {
const char *sig = NULL;
char *next = memchr(line, '\n', tail - line);
next = next ? next + 1 : tail;
if (in_signature && line[0] == ' ')
sig = line + 1;
else if (!prefixcmp(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;
}
cleanup:
free(buffer);
return saw_signature;
}
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_sha1_file(desc->obj->sha1, &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);
}
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;
enum object_type type;
char *buffer = read_sha1_file(commit->object.sha1, &type, &size);
if (buffer && type == OBJ_COMMIT)
extra = read_commit_extra_header_lines(buffer, size, exclude);
free(buffer);
return extra;
}
static inline int standard_header_field(const char *field, size_t len)
{
return ((len == 4 && !memcmp(field, "tree ", 5)) ||
(len == 6 && !memcmp(field, "parent ", 7)) ||
(len == 6 && !memcmp(field, "author ", 7)) ||
(len == 9 && !memcmp(field, "committer ", 10)) ||
(len == 8 && !memcmp(field, "encoding ", 9)));
}
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) && field[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 = strchr(line, ' ');
if (next <= eof)
eof = next;
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 struct strbuf *msg, unsigned char *tree,
struct commit_list *parents, unsigned char *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, 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;
while (len) {
unsigned char c = *buf++;
int bytes, bad_offset;
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 5 more bytes */
if (bytes < 1 || bytes > 5)
return bad_offset;
/* Do we *have* that many bytes? */
if (len < bytes)
return bad_offset;
offset += bytes;
len -= bytes;
/* And verify that they are good continuation bytes */
do {
if ((*buf++ & 0xc0) != 0x80)
return bad_offset;
} while (--bytes);
/* We could/should check the value and length here too */
}
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.
*
* Fixme: we should probably also disallow overlong forms and
* invalid characters. But we don't do that currently.
*/
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[] =
"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 struct strbuf *msg, unsigned char *tree,
struct commit_list *parents, unsigned char *ret,
const char *author, const char *sign_commit,
struct commit_extra_header *extra)
{
int result;
int encoding_is_utf8;
struct strbuf buffer;
assert_sha1_type(tree, OBJ_TREE);
if (memchr(msg->buf, '\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", sha1_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_list *next = parents->next;
struct commit *parent = parents->item;
strbuf_addf(&buffer, "parent %s\n",
sha1_to_hex(parent->object.sha1));
free(parents);
parents = next;
}
/* 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_addbuf(&buffer, msg);
/* 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))
return -1;
result = write_sha1_file(buffer.buf, buffer.len, commit_type, ret);
strbuf_release(&buffer);
return result;
}
struct commit *get_merge_parent(const char *name)
{
struct object *obj;
struct commit *commit;
unsigned char sha1[20];
if (get_sha1(name, sha1))
return NULL;
obj = parse_object(sha1);
commit = (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
if (commit && !commit->util) {
struct merge_remote_desc *desc;
desc = xmalloc(sizeof(*desc));
desc->obj = obj;
desc->name = strdup(name);
commit->util = desc;
}
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 = xmalloc(sizeof(struct commit_list));
new->item = commit;
*next = new;
new->next = NULL;
return &new->next;
}
void print_commit_list(struct commit_list *list,
const char *format_cur,
const char *format_last)
{
for ( ; list; list = list->next) {
const char *format = list->next ? format_cur : format_last;
printf(format, sha1_to_hex(list->item->object.sha1));
}
}