git/blame.c
Junio C Hamano 96379f043f Merge branch 'en/merge-directory-renames'
"git merge-recursive" backend recently learned a new heuristics to
infer file movement based on how other files in the same directory
moved.  As this is inherently less robust heuristics than the one
based on the content similarity of the file itself (rather than
based on what its neighbours are doing), it sometimes gives an
outcome unexpected by the end users.  This has been toned down to
leave the renamed paths in higher/conflicted stages in the index so
that the user can examine and confirm the result.

* en/merge-directory-renames:
  merge-recursive: switch directory rename detection default
  merge-recursive: give callers of handle_content_merge() access to contents
  merge-recursive: track information associated with directory renames
  t6043: fix copied test description to match its purpose
  merge-recursive: switch from (oid,mode) pairs to a diff_filespec
  merge-recursive: cleanup handle_rename_* function signatures
  merge-recursive: track branch where rename occurred in rename struct
  merge-recursive: remove ren[12]_other fields from rename_conflict_info
  merge-recursive: shrink rename_conflict_info
  merge-recursive: move some struct declarations together
  merge-recursive: use 'ci' for rename_conflict_info variable name
  merge-recursive: rename locals 'o' and 'a' to 'obuf' and 'abuf'
  merge-recursive: rename diff_filespec 'one' to 'o'
  merge-recursive: rename merge_options argument from 'o' to 'opt'
  Use 'unsigned short' for mode, like diff_filespec does
2019-05-09 00:37:22 +09:00

1906 lines
51 KiB
C

#include "cache.h"
#include "refs.h"
#include "object-store.h"
#include "cache-tree.h"
#include "mergesort.h"
#include "diff.h"
#include "diffcore.h"
#include "tag.h"
#include "blame.h"
#include "alloc.h"
#include "commit-slab.h"
define_commit_slab(blame_suspects, struct blame_origin *);
static struct blame_suspects blame_suspects;
struct blame_origin *get_blame_suspects(struct commit *commit)
{
struct blame_origin **result;
result = blame_suspects_peek(&blame_suspects, commit);
return result ? *result : NULL;
}
static void set_blame_suspects(struct commit *commit, struct blame_origin *origin)
{
*blame_suspects_at(&blame_suspects, commit) = origin;
}
void blame_origin_decref(struct blame_origin *o)
{
if (o && --o->refcnt <= 0) {
struct blame_origin *p, *l = NULL;
if (o->previous)
blame_origin_decref(o->previous);
free(o->file.ptr);
/* Should be present exactly once in commit chain */
for (p = get_blame_suspects(o->commit); p; l = p, p = p->next) {
if (p == o) {
if (l)
l->next = p->next;
else
set_blame_suspects(o->commit, p->next);
free(o);
return;
}
}
die("internal error in blame_origin_decref");
}
}
/*
* Given a commit and a path in it, create a new origin structure.
* The callers that add blame to the scoreboard should use
* get_origin() to obtain shared, refcounted copy instead of calling
* this function directly.
*/
static struct blame_origin *make_origin(struct commit *commit, const char *path)
{
struct blame_origin *o;
FLEX_ALLOC_STR(o, path, path);
o->commit = commit;
o->refcnt = 1;
o->next = get_blame_suspects(commit);
set_blame_suspects(commit, o);
return o;
}
/*
* Locate an existing origin or create a new one.
* This moves the origin to front position in the commit util list.
*/
static struct blame_origin *get_origin(struct commit *commit, const char *path)
{
struct blame_origin *o, *l;
for (o = get_blame_suspects(commit), l = NULL; o; l = o, o = o->next) {
if (!strcmp(o->path, path)) {
/* bump to front */
if (l) {
l->next = o->next;
o->next = get_blame_suspects(commit);
set_blame_suspects(commit, o);
}
return blame_origin_incref(o);
}
}
return make_origin(commit, path);
}
static void verify_working_tree_path(struct repository *r,
struct commit *work_tree, const char *path)
{
struct commit_list *parents;
int pos;
for (parents = work_tree->parents; parents; parents = parents->next) {
const struct object_id *commit_oid = &parents->item->object.oid;
struct object_id blob_oid;
unsigned short mode;
if (!get_tree_entry(commit_oid, path, &blob_oid, &mode) &&
oid_object_info(r, &blob_oid, NULL) == OBJ_BLOB)
return;
}
pos = index_name_pos(r->index, path, strlen(path));
if (pos >= 0)
; /* path is in the index */
else if (-1 - pos < r->index->cache_nr &&
!strcmp(r->index->cache[-1 - pos]->name, path))
; /* path is in the index, unmerged */
else
die("no such path '%s' in HEAD", path);
}
static struct commit_list **append_parent(struct repository *r,
struct commit_list **tail,
const struct object_id *oid)
{
struct commit *parent;
parent = lookup_commit_reference(r, oid);
if (!parent)
die("no such commit %s", oid_to_hex(oid));
return &commit_list_insert(parent, tail)->next;
}
static void append_merge_parents(struct repository *r,
struct commit_list **tail)
{
int merge_head;
struct strbuf line = STRBUF_INIT;
merge_head = open(git_path_merge_head(r), O_RDONLY);
if (merge_head < 0) {
if (errno == ENOENT)
return;
die("cannot open '%s' for reading",
git_path_merge_head(r));
}
while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
struct object_id oid;
if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid))
die("unknown line in '%s': %s",
git_path_merge_head(r), line.buf);
tail = append_parent(r, tail, &oid);
}
close(merge_head);
strbuf_release(&line);
}
/*
* This isn't as simple as passing sb->buf and sb->len, because we
* want to transfer ownership of the buffer to the commit (so we
* must use detach).
*/
static void set_commit_buffer_from_strbuf(struct repository *r,
struct commit *c,
struct strbuf *sb)
{
size_t len;
void *buf = strbuf_detach(sb, &len);
set_commit_buffer(r, c, buf, len);
}
/*
* Prepare a dummy commit that represents the work tree (or staged) item.
* Note that annotating work tree item never works in the reverse.
*/
static struct commit *fake_working_tree_commit(struct repository *r,
struct diff_options *opt,
const char *path,
const char *contents_from)
{
struct commit *commit;
struct blame_origin *origin;
struct commit_list **parent_tail, *parent;
struct object_id head_oid;
struct strbuf buf = STRBUF_INIT;
const char *ident;
time_t now;
int len;
struct cache_entry *ce;
unsigned mode;
struct strbuf msg = STRBUF_INIT;
repo_read_index(r);
time(&now);
commit = alloc_commit_node(r);
commit->object.parsed = 1;
commit->date = now;
parent_tail = &commit->parents;
if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
die("no such ref: HEAD");
parent_tail = append_parent(r, parent_tail, &head_oid);
append_merge_parents(r, parent_tail);
verify_working_tree_path(r, commit, path);
origin = make_origin(commit, path);
ident = fmt_ident("Not Committed Yet", "not.committed.yet",
WANT_BLANK_IDENT, NULL, 0);
strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n");
for (parent = commit->parents; parent; parent = parent->next)
strbuf_addf(&msg, "parent %s\n",
oid_to_hex(&parent->item->object.oid));
strbuf_addf(&msg,
"author %s\n"
"committer %s\n\n"
"Version of %s from %s\n",
ident, ident, path,
(!contents_from ? path :
(!strcmp(contents_from, "-") ? "standard input" : contents_from)));
set_commit_buffer_from_strbuf(r, commit, &msg);
if (!contents_from || strcmp("-", contents_from)) {
struct stat st;
const char *read_from;
char *buf_ptr;
unsigned long buf_len;
if (contents_from) {
if (stat(contents_from, &st) < 0)
die_errno("Cannot stat '%s'", contents_from);
read_from = contents_from;
}
else {
if (lstat(path, &st) < 0)
die_errno("Cannot lstat '%s'", path);
read_from = path;
}
mode = canon_mode(st.st_mode);
switch (st.st_mode & S_IFMT) {
case S_IFREG:
if (opt->flags.allow_textconv &&
textconv_object(r, read_from, mode, &null_oid, 0, &buf_ptr, &buf_len))
strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
die_errno("cannot open or read '%s'", read_from);
break;
case S_IFLNK:
if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
die_errno("cannot readlink '%s'", read_from);
break;
default:
die("unsupported file type %s", read_from);
}
}
else {
/* Reading from stdin */
mode = 0;
if (strbuf_read(&buf, 0, 0) < 0)
die_errno("failed to read from stdin");
}
convert_to_git(r->index, path, buf.buf, buf.len, &buf, 0);
origin->file.ptr = buf.buf;
origin->file.size = buf.len;
pretend_object_file(buf.buf, buf.len, OBJ_BLOB, &origin->blob_oid);
/*
* Read the current index, replace the path entry with
* origin->blob_sha1 without mucking with its mode or type
* bits; we are not going to write this index out -- we just
* want to run "diff-index --cached".
*/
discard_index(r->index);
repo_read_index(r);
len = strlen(path);
if (!mode) {
int pos = index_name_pos(r->index, path, len);
if (0 <= pos)
mode = r->index->cache[pos]->ce_mode;
else
/* Let's not bother reading from HEAD tree */
mode = S_IFREG | 0644;
}
ce = make_empty_cache_entry(r->index, len);
oidcpy(&ce->oid, &origin->blob_oid);
memcpy(ce->name, path, len);
ce->ce_flags = create_ce_flags(0);
ce->ce_namelen = len;
ce->ce_mode = create_ce_mode(mode);
add_index_entry(r->index, ce,
ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
cache_tree_invalidate_path(r->index, path);
return commit;
}
static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, int xdl_opts)
{
xpparam_t xpp = {0};
xdemitconf_t xecfg = {0};
xdemitcb_t ecb = {NULL};
xpp.flags = xdl_opts;
xecfg.hunk_func = hunk_func;
ecb.priv = cb_data;
return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
}
/*
* Given an origin, prepare mmfile_t structure to be used by the
* diff machinery
*/
static void fill_origin_blob(struct diff_options *opt,
struct blame_origin *o, mmfile_t *file, int *num_read_blob)
{
if (!o->file.ptr) {
enum object_type type;
unsigned long file_size;
(*num_read_blob)++;
if (opt->flags.allow_textconv &&
textconv_object(opt->repo, o->path, o->mode,
&o->blob_oid, 1, &file->ptr, &file_size))
;
else
file->ptr = read_object_file(&o->blob_oid, &type,
&file_size);
file->size = file_size;
if (!file->ptr)
die("Cannot read blob %s for path %s",
oid_to_hex(&o->blob_oid),
o->path);
o->file = *file;
}
else
*file = o->file;
}
static void drop_origin_blob(struct blame_origin *o)
{
FREE_AND_NULL(o->file.ptr);
}
/*
* Any merge of blames happens on lists of blames that arrived via
* different parents in a single suspect. In this case, we want to
* sort according to the suspect line numbers as opposed to the final
* image line numbers. The function body is somewhat longish because
* it avoids unnecessary writes.
*/
static struct blame_entry *blame_merge(struct blame_entry *list1,
struct blame_entry *list2)
{
struct blame_entry *p1 = list1, *p2 = list2,
**tail = &list1;
if (!p1)
return p2;
if (!p2)
return p1;
if (p1->s_lno <= p2->s_lno) {
do {
tail = &p1->next;
if ((p1 = *tail) == NULL) {
*tail = p2;
return list1;
}
} while (p1->s_lno <= p2->s_lno);
}
for (;;) {
*tail = p2;
do {
tail = &p2->next;
if ((p2 = *tail) == NULL) {
*tail = p1;
return list1;
}
} while (p1->s_lno > p2->s_lno);
*tail = p1;
do {
tail = &p1->next;
if ((p1 = *tail) == NULL) {
*tail = p2;
return list1;
}
} while (p1->s_lno <= p2->s_lno);
}
}
static void *get_next_blame(const void *p)
{
return ((struct blame_entry *)p)->next;
}
static void set_next_blame(void *p1, void *p2)
{
((struct blame_entry *)p1)->next = p2;
}
/*
* Final image line numbers are all different, so we don't need a
* three-way comparison here.
*/
static int compare_blame_final(const void *p1, const void *p2)
{
return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
? 1 : -1;
}
static int compare_blame_suspect(const void *p1, const void *p2)
{
const struct blame_entry *s1 = p1, *s2 = p2;
/*
* to allow for collating suspects, we sort according to the
* respective pointer value as the primary sorting criterion.
* The actual relation is pretty unimportant as long as it
* establishes a total order. Comparing as integers gives us
* that.
*/
if (s1->suspect != s2->suspect)
return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
if (s1->s_lno == s2->s_lno)
return 0;
return s1->s_lno > s2->s_lno ? 1 : -1;
}
void blame_sort_final(struct blame_scoreboard *sb)
{
sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame,
compare_blame_final);
}
static int compare_commits_by_reverse_commit_date(const void *a,
const void *b,
void *c)
{
return -compare_commits_by_commit_date(a, b, c);
}
/*
* For debugging -- origin is refcounted, and this asserts that
* we do not underflow.
*/
static void sanity_check_refcnt(struct blame_scoreboard *sb)
{
int baa = 0;
struct blame_entry *ent;
for (ent = sb->ent; ent; ent = ent->next) {
/* Nobody should have zero or negative refcnt */
if (ent->suspect->refcnt <= 0) {
fprintf(stderr, "%s in %s has negative refcnt %d\n",
ent->suspect->path,
oid_to_hex(&ent->suspect->commit->object.oid),
ent->suspect->refcnt);
baa = 1;
}
}
if (baa)
sb->on_sanity_fail(sb, baa);
}
/*
* If two blame entries that are next to each other came from
* contiguous lines in the same origin (i.e. <commit, path> pair),
* merge them together.
*/
void blame_coalesce(struct blame_scoreboard *sb)
{
struct blame_entry *ent, *next;
for (ent = sb->ent; ent && (next = ent->next); ent = next) {
if (ent->suspect == next->suspect &&
ent->s_lno + ent->num_lines == next->s_lno) {
ent->num_lines += next->num_lines;
ent->next = next->next;
blame_origin_decref(next->suspect);
free(next);
ent->score = 0;
next = ent; /* again */
}
}
if (sb->debug) /* sanity */
sanity_check_refcnt(sb);
}
/*
* Merge the given sorted list of blames into a preexisting origin.
* If there were no previous blames to that commit, it is entered into
* the commit priority queue of the score board.
*/
static void queue_blames(struct blame_scoreboard *sb, struct blame_origin *porigin,
struct blame_entry *sorted)
{
if (porigin->suspects)
porigin->suspects = blame_merge(porigin->suspects, sorted);
else {
struct blame_origin *o;
for (o = get_blame_suspects(porigin->commit); o; o = o->next) {
if (o->suspects) {
porigin->suspects = sorted;
return;
}
}
porigin->suspects = sorted;
prio_queue_put(&sb->commits, porigin->commit);
}
}
/*
* Fill the blob_sha1 field of an origin if it hasn't, so that later
* call to fill_origin_blob() can use it to locate the data. blob_sha1
* for an origin is also used to pass the blame for the entire file to
* the parent to detect the case where a child's blob is identical to
* that of its parent's.
*
* This also fills origin->mode for corresponding tree path.
*/
static int fill_blob_sha1_and_mode(struct repository *r,
struct blame_origin *origin)
{
if (!is_null_oid(&origin->blob_oid))
return 0;
if (get_tree_entry(&origin->commit->object.oid, origin->path, &origin->blob_oid, &origin->mode))
goto error_out;
if (oid_object_info(r, &origin->blob_oid, NULL) != OBJ_BLOB)
goto error_out;
return 0;
error_out:
oidclr(&origin->blob_oid);
origin->mode = S_IFINVALID;
return -1;
}
/*
* We have an origin -- check if the same path exists in the
* parent and return an origin structure to represent it.
*/
static struct blame_origin *find_origin(struct repository *r,
struct commit *parent,
struct blame_origin *origin)
{
struct blame_origin *porigin;
struct diff_options diff_opts;
const char *paths[2];
/* First check any existing origins */
for (porigin = get_blame_suspects(parent); porigin; porigin = porigin->next)
if (!strcmp(porigin->path, origin->path)) {
/*
* The same path between origin and its parent
* without renaming -- the most common case.
*/
return blame_origin_incref (porigin);
}
/* See if the origin->path is different between parent
* and origin first. Most of the time they are the
* same and diff-tree is fairly efficient about this.
*/
repo_diff_setup(r, &diff_opts);
diff_opts.flags.recursive = 1;
diff_opts.detect_rename = 0;
diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
paths[0] = origin->path;
paths[1] = NULL;
parse_pathspec(&diff_opts.pathspec,
PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
PATHSPEC_LITERAL_PATH, "", paths);
diff_setup_done(&diff_opts);
if (is_null_oid(&origin->commit->object.oid))
do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
else
diff_tree_oid(get_commit_tree_oid(parent),
get_commit_tree_oid(origin->commit),
"", &diff_opts);
diffcore_std(&diff_opts);
if (!diff_queued_diff.nr) {
/* The path is the same as parent */
porigin = get_origin(parent, origin->path);
oidcpy(&porigin->blob_oid, &origin->blob_oid);
porigin->mode = origin->mode;
} else {
/*
* Since origin->path is a pathspec, if the parent
* commit had it as a directory, we will see a whole
* bunch of deletion of files in the directory that we
* do not care about.
*/
int i;
struct diff_filepair *p = NULL;
for (i = 0; i < diff_queued_diff.nr; i++) {
const char *name;
p = diff_queued_diff.queue[i];
name = p->one->path ? p->one->path : p->two->path;
if (!strcmp(name, origin->path))
break;
}
if (!p)
die("internal error in blame::find_origin");
switch (p->status) {
default:
die("internal error in blame::find_origin (%c)",
p->status);
case 'M':
porigin = get_origin(parent, origin->path);
oidcpy(&porigin->blob_oid, &p->one->oid);
porigin->mode = p->one->mode;
break;
case 'A':
case 'T':
/* Did not exist in parent, or type changed */
break;
}
}
diff_flush(&diff_opts);
clear_pathspec(&diff_opts.pathspec);
return porigin;
}
/*
* We have an origin -- find the path that corresponds to it in its
* parent and return an origin structure to represent it.
*/
static struct blame_origin *find_rename(struct repository *r,
struct commit *parent,
struct blame_origin *origin)
{
struct blame_origin *porigin = NULL;
struct diff_options diff_opts;
int i;
repo_diff_setup(r, &diff_opts);
diff_opts.flags.recursive = 1;
diff_opts.detect_rename = DIFF_DETECT_RENAME;
diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_opts.single_follow = origin->path;
diff_setup_done(&diff_opts);
if (is_null_oid(&origin->commit->object.oid))
do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
else
diff_tree_oid(get_commit_tree_oid(parent),
get_commit_tree_oid(origin->commit),
"", &diff_opts);
diffcore_std(&diff_opts);
for (i = 0; i < diff_queued_diff.nr; i++) {
struct diff_filepair *p = diff_queued_diff.queue[i];
if ((p->status == 'R' || p->status == 'C') &&
!strcmp(p->two->path, origin->path)) {
porigin = get_origin(parent, p->one->path);
oidcpy(&porigin->blob_oid, &p->one->oid);
porigin->mode = p->one->mode;
break;
}
}
diff_flush(&diff_opts);
clear_pathspec(&diff_opts.pathspec);
return porigin;
}
/*
* Append a new blame entry to a given output queue.
*/
static void add_blame_entry(struct blame_entry ***queue,
const struct blame_entry *src)
{
struct blame_entry *e = xmalloc(sizeof(*e));
memcpy(e, src, sizeof(*e));
blame_origin_incref(e->suspect);
e->next = **queue;
**queue = e;
*queue = &e->next;
}
/*
* src typically is on-stack; we want to copy the information in it to
* a malloced blame_entry that gets added to the given queue. The
* origin of dst loses a refcnt.
*/
static void dup_entry(struct blame_entry ***queue,
struct blame_entry *dst, struct blame_entry *src)
{
blame_origin_incref(src->suspect);
blame_origin_decref(dst->suspect);
memcpy(dst, src, sizeof(*src));
dst->next = **queue;
**queue = dst;
*queue = &dst->next;
}
const char *blame_nth_line(struct blame_scoreboard *sb, long lno)
{
return sb->final_buf + sb->lineno[lno];
}
/*
* It is known that lines between tlno to same came from parent, and e
* has an overlap with that range. it also is known that parent's
* line plno corresponds to e's line tlno.
*
* <---- e ----->
* <------>
* <------------>
* <------------>
* <------------------>
*
* Split e into potentially three parts; before this chunk, the chunk
* to be blamed for the parent, and after that portion.
*/
static void split_overlap(struct blame_entry *split,
struct blame_entry *e,
int tlno, int plno, int same,
struct blame_origin *parent)
{
int chunk_end_lno;
memset(split, 0, sizeof(struct blame_entry [3]));
if (e->s_lno < tlno) {
/* there is a pre-chunk part not blamed on parent */
split[0].suspect = blame_origin_incref(e->suspect);
split[0].lno = e->lno;
split[0].s_lno = e->s_lno;
split[0].num_lines = tlno - e->s_lno;
split[1].lno = e->lno + tlno - e->s_lno;
split[1].s_lno = plno;
}
else {
split[1].lno = e->lno;
split[1].s_lno = plno + (e->s_lno - tlno);
}
if (same < e->s_lno + e->num_lines) {
/* there is a post-chunk part not blamed on parent */
split[2].suspect = blame_origin_incref(e->suspect);
split[2].lno = e->lno + (same - e->s_lno);
split[2].s_lno = e->s_lno + (same - e->s_lno);
split[2].num_lines = e->s_lno + e->num_lines - same;
chunk_end_lno = split[2].lno;
}
else
chunk_end_lno = e->lno + e->num_lines;
split[1].num_lines = chunk_end_lno - split[1].lno;
/*
* if it turns out there is nothing to blame the parent for,
* forget about the splitting. !split[1].suspect signals this.
*/
if (split[1].num_lines < 1)
return;
split[1].suspect = blame_origin_incref(parent);
}
/*
* split_overlap() divided an existing blame e into up to three parts
* in split. Any assigned blame is moved to queue to
* reflect the split.
*/
static void split_blame(struct blame_entry ***blamed,
struct blame_entry ***unblamed,
struct blame_entry *split,
struct blame_entry *e)
{
if (split[0].suspect && split[2].suspect) {
/* The first part (reuse storage for the existing entry e) */
dup_entry(unblamed, e, &split[0]);
/* The last part -- me */
add_blame_entry(unblamed, &split[2]);
/* ... and the middle part -- parent */
add_blame_entry(blamed, &split[1]);
}
else if (!split[0].suspect && !split[2].suspect)
/*
* The parent covers the entire area; reuse storage for
* e and replace it with the parent.
*/
dup_entry(blamed, e, &split[1]);
else if (split[0].suspect) {
/* me and then parent */
dup_entry(unblamed, e, &split[0]);
add_blame_entry(blamed, &split[1]);
}
else {
/* parent and then me */
dup_entry(blamed, e, &split[1]);
add_blame_entry(unblamed, &split[2]);
}
}
/*
* After splitting the blame, the origins used by the
* on-stack blame_entry should lose one refcnt each.
*/
static void decref_split(struct blame_entry *split)
{
int i;
for (i = 0; i < 3; i++)
blame_origin_decref(split[i].suspect);
}
/*
* reverse_blame reverses the list given in head, appending tail.
* That allows us to build lists in reverse order, then reverse them
* afterwards. This can be faster than building the list in proper
* order right away. The reason is that building in proper order
* requires writing a link in the _previous_ element, while building
* in reverse order just requires placing the list head into the
* _current_ element.
*/
static struct blame_entry *reverse_blame(struct blame_entry *head,
struct blame_entry *tail)
{
while (head) {
struct blame_entry *next = head->next;
head->next = tail;
tail = head;
head = next;
}
return tail;
}
/*
* Process one hunk from the patch between the current suspect for
* blame_entry e and its parent. This first blames any unfinished
* entries before the chunk (which is where target and parent start
* differing) on the parent, and then splits blame entries at the
* start and at the end of the difference region. Since use of -M and
* -C options may lead to overlapping/duplicate source line number
* ranges, all we can rely on from sorting/merging is the order of the
* first suspect line number.
*/
static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
int tlno, int offset, int same,
struct blame_origin *parent)
{
struct blame_entry *e = **srcq;
struct blame_entry *samep = NULL, *diffp = NULL;
while (e && e->s_lno < tlno) {
struct blame_entry *next = e->next;
/*
* current record starts before differing portion. If
* it reaches into it, we need to split it up and
* examine the second part separately.
*/
if (e->s_lno + e->num_lines > tlno) {
/* Move second half to a new record */
int len = tlno - e->s_lno;
struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
n->suspect = e->suspect;
n->lno = e->lno + len;
n->s_lno = e->s_lno + len;
n->num_lines = e->num_lines - len;
e->num_lines = len;
e->score = 0;
/* Push new record to diffp */
n->next = diffp;
diffp = n;
} else
blame_origin_decref(e->suspect);
/* Pass blame for everything before the differing
* chunk to the parent */
e->suspect = blame_origin_incref(parent);
e->s_lno += offset;
e->next = samep;
samep = e;
e = next;
}
/*
* As we don't know how much of a common stretch after this
* diff will occur, the currently blamed parts are all that we
* can assign to the parent for now.
*/
if (samep) {
**dstq = reverse_blame(samep, **dstq);
*dstq = &samep->next;
}
/*
* Prepend the split off portions: everything after e starts
* after the blameable portion.
*/
e = reverse_blame(diffp, e);
/*
* Now retain records on the target while parts are different
* from the parent.
*/
samep = NULL;
diffp = NULL;
while (e && e->s_lno < same) {
struct blame_entry *next = e->next;
/*
* If current record extends into sameness, need to split.
*/
if (e->s_lno + e->num_lines > same) {
/*
* Move second half to a new record to be
* processed by later chunks
*/
int len = same - e->s_lno;
struct blame_entry *n = xcalloc(1, sizeof (struct blame_entry));
n->suspect = blame_origin_incref(e->suspect);
n->lno = e->lno + len;
n->s_lno = e->s_lno + len;
n->num_lines = e->num_lines - len;
e->num_lines = len;
e->score = 0;
/* Push new record to samep */
n->next = samep;
samep = n;
}
e->next = diffp;
diffp = e;
e = next;
}
**srcq = reverse_blame(diffp, reverse_blame(samep, e));
/* Move across elements that are in the unblamable portion */
if (diffp)
*srcq = &diffp->next;
}
struct blame_chunk_cb_data {
struct blame_origin *parent;
long offset;
struct blame_entry **dstq;
struct blame_entry **srcq;
};
/* diff chunks are from parent to target */
static int blame_chunk_cb(long start_a, long count_a,
long start_b, long count_b, void *data)
{
struct blame_chunk_cb_data *d = data;
if (start_a - start_b != d->offset)
die("internal error in blame::blame_chunk_cb");
blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
start_b + count_b, d->parent);
d->offset = start_a + count_a - (start_b + count_b);
return 0;
}
/*
* We are looking at the origin 'target' and aiming to pass blame
* for the lines it is suspected to its parent. Run diff to find
* which lines came from parent and pass blame for them.
*/
static void pass_blame_to_parent(struct blame_scoreboard *sb,
struct blame_origin *target,
struct blame_origin *parent)
{
mmfile_t file_p, file_o;
struct blame_chunk_cb_data d;
struct blame_entry *newdest = NULL;
if (!target->suspects)
return; /* nothing remains for this target */
d.parent = parent;
d.offset = 0;
d.dstq = &newdest; d.srcq = &target->suspects;
fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
fill_origin_blob(&sb->revs->diffopt, target, &file_o, &sb->num_read_blob);
sb->num_get_patch++;
if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
die("unable to generate diff (%s -> %s)",
oid_to_hex(&parent->commit->object.oid),
oid_to_hex(&target->commit->object.oid));
/* The rest are the same as the parent */
blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
*d.dstq = NULL;
queue_blames(sb, parent, newdest);
return;
}
/*
* The lines in blame_entry after splitting blames many times can become
* very small and trivial, and at some point it becomes pointless to
* blame the parents. E.g. "\t\t}\n\t}\n\n" appears everywhere in any
* ordinary C program, and it is not worth to say it was copied from
* totally unrelated file in the parent.
*
* Compute how trivial the lines in the blame_entry are.
*/
unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e)
{
unsigned score;
const char *cp, *ep;
if (e->score)
return e->score;
score = 1;
cp = blame_nth_line(sb, e->lno);
ep = blame_nth_line(sb, e->lno + e->num_lines);
while (cp < ep) {
unsigned ch = *((unsigned char *)cp);
if (isalnum(ch))
score++;
cp++;
}
e->score = score;
return score;
}
/*
* best_so_far[] and potential[] are both a split of an existing blame_entry
* that passes blame to the parent. Maintain best_so_far the best split so
* far, by comparing potential and best_so_far and copying potential into
* bst_so_far as needed.
*/
static void copy_split_if_better(struct blame_scoreboard *sb,
struct blame_entry *best_so_far,
struct blame_entry *potential)
{
int i;
if (!potential[1].suspect)
return;
if (best_so_far[1].suspect) {
if (blame_entry_score(sb, &potential[1]) <
blame_entry_score(sb, &best_so_far[1]))
return;
}
for (i = 0; i < 3; i++)
blame_origin_incref(potential[i].suspect);
decref_split(best_so_far);
memcpy(best_so_far, potential, sizeof(struct blame_entry[3]));
}
/*
* We are looking at a part of the final image represented by
* ent (tlno and same are offset by ent->s_lno).
* tlno is where we are looking at in the final image.
* up to (but not including) same match preimage.
* plno is where we are looking at in the preimage.
*
* <-------------- final image ---------------------->
* <------ent------>
* ^tlno ^same
* <---------preimage----->
* ^plno
*
* All line numbers are 0-based.
*/
static void handle_split(struct blame_scoreboard *sb,
struct blame_entry *ent,
int tlno, int plno, int same,
struct blame_origin *parent,
struct blame_entry *split)
{
if (ent->num_lines <= tlno)
return;
if (tlno < same) {
struct blame_entry potential[3];
tlno += ent->s_lno;
same += ent->s_lno;
split_overlap(potential, ent, tlno, plno, same, parent);
copy_split_if_better(sb, split, potential);
decref_split(potential);
}
}
struct handle_split_cb_data {
struct blame_scoreboard *sb;
struct blame_entry *ent;
struct blame_origin *parent;
struct blame_entry *split;
long plno;
long tlno;
};
static int handle_split_cb(long start_a, long count_a,
long start_b, long count_b, void *data)
{
struct handle_split_cb_data *d = data;
handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
d->split);
d->plno = start_a + count_a;
d->tlno = start_b + count_b;
return 0;
}
/*
* Find the lines from parent that are the same as ent so that
* we can pass blames to it. file_p has the blob contents for
* the parent.
*/
static void find_copy_in_blob(struct blame_scoreboard *sb,
struct blame_entry *ent,
struct blame_origin *parent,
struct blame_entry *split,
mmfile_t *file_p)
{
const char *cp;
mmfile_t file_o;
struct handle_split_cb_data d;
memset(&d, 0, sizeof(d));
d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
/*
* Prepare mmfile that contains only the lines in ent.
*/
cp = blame_nth_line(sb, ent->lno);
file_o.ptr = (char *) cp;
file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;
/*
* file_o is a part of final image we are annotating.
* file_p partially may match that image.
*/
memset(split, 0, sizeof(struct blame_entry [3]));
if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))
die("unable to generate diff (%s)",
oid_to_hex(&parent->commit->object.oid));
/* remainder, if any, all match the preimage */
handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
}
/* Move all blame entries from list *source that have a score smaller
* than score_min to the front of list *small.
* Returns a pointer to the link pointing to the old head of the small list.
*/
static struct blame_entry **filter_small(struct blame_scoreboard *sb,
struct blame_entry **small,
struct blame_entry **source,
unsigned score_min)
{
struct blame_entry *p = *source;
struct blame_entry *oldsmall = *small;
while (p) {
if (blame_entry_score(sb, p) <= score_min) {
*small = p;
small = &p->next;
p = *small;
} else {
*source = p;
source = &p->next;
p = *source;
}
}
*small = oldsmall;
*source = NULL;
return small;
}
/*
* See if lines currently target is suspected for can be attributed to
* parent.
*/
static void find_move_in_parent(struct blame_scoreboard *sb,
struct blame_entry ***blamed,
struct blame_entry **toosmall,
struct blame_origin *target,
struct blame_origin *parent)
{
struct blame_entry *e, split[3];
struct blame_entry *unblamed = target->suspects;
struct blame_entry *leftover = NULL;
mmfile_t file_p;
if (!unblamed)
return; /* nothing remains for this target */
fill_origin_blob(&sb->revs->diffopt, parent, &file_p, &sb->num_read_blob);
if (!file_p.ptr)
return;
/* At each iteration, unblamed has a NULL-terminated list of
* entries that have not yet been tested for blame. leftover
* contains the reversed list of entries that have been tested
* without being assignable to the parent.
*/
do {
struct blame_entry **unblamedtail = &unblamed;
struct blame_entry *next;
for (e = unblamed; e; e = next) {
next = e->next;
find_copy_in_blob(sb, e, parent, split, &file_p);
if (split[1].suspect &&
sb->move_score < blame_entry_score(sb, &split[1])) {
split_blame(blamed, &unblamedtail, split, e);
} else {
e->next = leftover;
leftover = e;
}
decref_split(split);
}
*unblamedtail = NULL;
toosmall = filter_small(sb, toosmall, &unblamed, sb->move_score);
} while (unblamed);
target->suspects = reverse_blame(leftover, NULL);
}
struct blame_list {
struct blame_entry *ent;
struct blame_entry split[3];
};
/*
* Count the number of entries the target is suspected for,
* and prepare a list of entry and the best split.
*/
static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
int *num_ents_p)
{
struct blame_entry *e;
int num_ents, i;
struct blame_list *blame_list = NULL;
for (e = unblamed, num_ents = 0; e; e = e->next)
num_ents++;
if (num_ents) {
blame_list = xcalloc(num_ents, sizeof(struct blame_list));
for (e = unblamed, i = 0; e; e = e->next)
blame_list[i++].ent = e;
}
*num_ents_p = num_ents;
return blame_list;
}
/*
* For lines target is suspected for, see if we can find code movement
* across file boundary from the parent commit. porigin is the path
* in the parent we already tried.
*/
static void find_copy_in_parent(struct blame_scoreboard *sb,
struct blame_entry ***blamed,
struct blame_entry **toosmall,
struct blame_origin *target,
struct commit *parent,
struct blame_origin *porigin,
int opt)
{
struct diff_options diff_opts;
int i, j;
struct blame_list *blame_list;
int num_ents;
struct blame_entry *unblamed = target->suspects;
struct blame_entry *leftover = NULL;
if (!unblamed)
return; /* nothing remains for this target */
repo_diff_setup(sb->repo, &diff_opts);
diff_opts.flags.recursive = 1;
diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_setup_done(&diff_opts);
/* Try "find copies harder" on new path if requested;
* we do not want to use diffcore_rename() actually to
* match things up; find_copies_harder is set only to
* force diff_tree_oid() to feed all filepairs to diff_queue,
* and this code needs to be after diff_setup_done(), which
* usually makes find-copies-harder imply copy detection.
*/
if ((opt & PICKAXE_BLAME_COPY_HARDEST)
|| ((opt & PICKAXE_BLAME_COPY_HARDER)
&& (!porigin || strcmp(target->path, porigin->path))))
diff_opts.flags.find_copies_harder = 1;
if (is_null_oid(&target->commit->object.oid))
do_diff_cache(get_commit_tree_oid(parent), &diff_opts);
else
diff_tree_oid(get_commit_tree_oid(parent),
get_commit_tree_oid(target->commit),
"", &diff_opts);
if (!diff_opts.flags.find_copies_harder)
diffcore_std(&diff_opts);
do {
struct blame_entry **unblamedtail = &unblamed;
blame_list = setup_blame_list(unblamed, &num_ents);
for (i = 0; i < diff_queued_diff.nr; i++) {
struct diff_filepair *p = diff_queued_diff.queue[i];
struct blame_origin *norigin;
mmfile_t file_p;
struct blame_entry potential[3];
if (!DIFF_FILE_VALID(p->one))
continue; /* does not exist in parent */
if (S_ISGITLINK(p->one->mode))
continue; /* ignore git links */
if (porigin && !strcmp(p->one->path, porigin->path))
/* find_move already dealt with this path */
continue;
norigin = get_origin(parent, p->one->path);
oidcpy(&norigin->blob_oid, &p->one->oid);
norigin->mode = p->one->mode;
fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, &sb->num_read_blob);
if (!file_p.ptr)
continue;
for (j = 0; j < num_ents; j++) {
find_copy_in_blob(sb, blame_list[j].ent,
norigin, potential, &file_p);
copy_split_if_better(sb, blame_list[j].split,
potential);
decref_split(potential);
}
blame_origin_decref(norigin);
}
for (j = 0; j < num_ents; j++) {
struct blame_entry *split = blame_list[j].split;
if (split[1].suspect &&
sb->copy_score < blame_entry_score(sb, &split[1])) {
split_blame(blamed, &unblamedtail, split,
blame_list[j].ent);
} else {
blame_list[j].ent->next = leftover;
leftover = blame_list[j].ent;
}
decref_split(split);
}
free(blame_list);
*unblamedtail = NULL;
toosmall = filter_small(sb, toosmall, &unblamed, sb->copy_score);
} while (unblamed);
target->suspects = reverse_blame(leftover, NULL);
diff_flush(&diff_opts);
clear_pathspec(&diff_opts.pathspec);
}
/*
* The blobs of origin and porigin exactly match, so everything
* origin is suspected for can be blamed on the parent.
*/
static void pass_whole_blame(struct blame_scoreboard *sb,
struct blame_origin *origin, struct blame_origin *porigin)
{
struct blame_entry *e, *suspects;
if (!porigin->file.ptr && origin->file.ptr) {
/* Steal its file */
porigin->file = origin->file;
origin->file.ptr = NULL;
}
suspects = origin->suspects;
origin->suspects = NULL;
for (e = suspects; e; e = e->next) {
blame_origin_incref(porigin);
blame_origin_decref(e->suspect);
e->suspect = porigin;
}
queue_blames(sb, porigin, suspects);
}
/*
* We pass blame from the current commit to its parents. We keep saying
* "parent" (and "porigin"), but what we mean is to find scapegoat to
* exonerate ourselves.
*/
static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit,
int reverse)
{
if (!reverse) {
if (revs->first_parent_only &&
commit->parents &&
commit->parents->next) {
free_commit_list(commit->parents->next);
commit->parents->next = NULL;
}
return commit->parents;
}
return lookup_decoration(&revs->children, &commit->object);
}
static int num_scapegoats(struct rev_info *revs, struct commit *commit, int reverse)
{
struct commit_list *l = first_scapegoat(revs, commit, reverse);
return commit_list_count(l);
}
/* Distribute collected unsorted blames to the respected sorted lists
* in the various origins.
*/
static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry *blamed)
{
blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,
compare_blame_suspect);
while (blamed)
{
struct blame_origin *porigin = blamed->suspect;
struct blame_entry *suspects = NULL;
do {
struct blame_entry *next = blamed->next;
blamed->next = suspects;
suspects = blamed;
blamed = next;
} while (blamed && blamed->suspect == porigin);
suspects = reverse_blame(suspects, NULL);
queue_blames(sb, porigin, suspects);
}
}
#define MAXSG 16
static void pass_blame(struct blame_scoreboard *sb, struct blame_origin *origin, int opt)
{
struct rev_info *revs = sb->revs;
int i, pass, num_sg;
struct commit *commit = origin->commit;
struct commit_list *sg;
struct blame_origin *sg_buf[MAXSG];
struct blame_origin *porigin, **sg_origin = sg_buf;
struct blame_entry *toosmall = NULL;
struct blame_entry *blames, **blametail = &blames;
num_sg = num_scapegoats(revs, commit, sb->reverse);
if (!num_sg)
goto finish;
else if (num_sg < ARRAY_SIZE(sg_buf))
memset(sg_buf, 0, sizeof(sg_buf));
else
sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
/*
* The first pass looks for unrenamed path to optimize for
* common cases, then we look for renames in the second pass.
*/
for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {
struct blame_origin *(*find)(struct repository *, struct commit *, struct blame_origin *);
find = pass ? find_rename : find_origin;
for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
i < num_sg && sg;
sg = sg->next, i++) {
struct commit *p = sg->item;
int j, same;
if (sg_origin[i])
continue;
if (parse_commit(p))
continue;
porigin = find(sb->repo, p, origin);
if (!porigin)
continue;
if (oideq(&porigin->blob_oid, &origin->blob_oid)) {
pass_whole_blame(sb, origin, porigin);
blame_origin_decref(porigin);
goto finish;
}
for (j = same = 0; j < i; j++)
if (sg_origin[j] &&
oideq(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {
same = 1;
break;
}
if (!same)
sg_origin[i] = porigin;
else
blame_origin_decref(porigin);
}
}
sb->num_commits++;
for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
i < num_sg && sg;
sg = sg->next, i++) {
struct blame_origin *porigin = sg_origin[i];
if (!porigin)
continue;
if (!origin->previous) {
blame_origin_incref(porigin);
origin->previous = porigin;
}
pass_blame_to_parent(sb, origin, porigin);
if (!origin->suspects)
goto finish;
}
/*
* Optionally find moves in parents' files.
*/
if (opt & PICKAXE_BLAME_MOVE) {
filter_small(sb, &toosmall, &origin->suspects, sb->move_score);
if (origin->suspects) {
for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
i < num_sg && sg;
sg = sg->next, i++) {
struct blame_origin *porigin = sg_origin[i];
if (!porigin)
continue;
find_move_in_parent(sb, &blametail, &toosmall, origin, porigin);
if (!origin->suspects)
break;
}
}
}
/*
* Optionally find copies from parents' files.
*/
if (opt & PICKAXE_BLAME_COPY) {
if (sb->copy_score > sb->move_score)
filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
else if (sb->copy_score < sb->move_score) {
origin->suspects = blame_merge(origin->suspects, toosmall);
toosmall = NULL;
filter_small(sb, &toosmall, &origin->suspects, sb->copy_score);
}
if (!origin->suspects)
goto finish;
for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
i < num_sg && sg;
sg = sg->next, i++) {
struct blame_origin *porigin = sg_origin[i];
find_copy_in_parent(sb, &blametail, &toosmall,
origin, sg->item, porigin, opt);
if (!origin->suspects)
goto finish;
}
}
finish:
*blametail = NULL;
distribute_blame(sb, blames);
/*
* prepend toosmall to origin->suspects
*
* There is no point in sorting: this ends up on a big
* unsorted list in the caller anyway.
*/
if (toosmall) {
struct blame_entry **tail = &toosmall;
while (*tail)
tail = &(*tail)->next;
*tail = origin->suspects;
origin->suspects = toosmall;
}
for (i = 0; i < num_sg; i++) {
if (sg_origin[i]) {
if (!sg_origin[i]->suspects)
drop_origin_blob(sg_origin[i]);
blame_origin_decref(sg_origin[i]);
}
}
drop_origin_blob(origin);
if (sg_buf != sg_origin)
free(sg_origin);
}
/*
* The main loop -- while we have blobs with lines whose true origin
* is still unknown, pick one blob, and allow its lines to pass blames
* to its parents. */
void assign_blame(struct blame_scoreboard *sb, int opt)
{
struct rev_info *revs = sb->revs;
struct commit *commit = prio_queue_get(&sb->commits);
while (commit) {
struct blame_entry *ent;
struct blame_origin *suspect = get_blame_suspects(commit);
/* find one suspect to break down */
while (suspect && !suspect->suspects)
suspect = suspect->next;
if (!suspect) {
commit = prio_queue_get(&sb->commits);
continue;
}
assert(commit == suspect->commit);
/*
* We will use this suspect later in the loop,
* so hold onto it in the meantime.
*/
blame_origin_incref(suspect);
parse_commit(commit);
if (sb->reverse ||
(!(commit->object.flags & UNINTERESTING) &&
!(revs->max_age != -1 && commit->date < revs->max_age)))
pass_blame(sb, suspect, opt);
else {
commit->object.flags |= UNINTERESTING;
if (commit->object.parsed)
mark_parents_uninteresting(commit);
}
/* treat root commit as boundary */
if (!commit->parents && !sb->show_root)
commit->object.flags |= UNINTERESTING;
/* Take responsibility for the remaining entries */
ent = suspect->suspects;
if (ent) {
suspect->guilty = 1;
for (;;) {
struct blame_entry *next = ent->next;
if (sb->found_guilty_entry)
sb->found_guilty_entry(ent, sb->found_guilty_entry_data);
if (next) {
ent = next;
continue;
}
ent->next = sb->ent;
sb->ent = suspect->suspects;
suspect->suspects = NULL;
break;
}
}
blame_origin_decref(suspect);
if (sb->debug) /* sanity */
sanity_check_refcnt(sb);
}
}
static const char *get_next_line(const char *start, const char *end)
{
const char *nl = memchr(start, '\n', end - start);
return nl ? nl + 1 : end;
}
/*
* To allow quick access to the contents of nth line in the
* final image, prepare an index in the scoreboard.
*/
static int prepare_lines(struct blame_scoreboard *sb)
{
const char *buf = sb->final_buf;
unsigned long len = sb->final_buf_size;
const char *end = buf + len;
const char *p;
int *lineno;
int num = 0;
for (p = buf; p < end; p = get_next_line(p, end))
num++;
ALLOC_ARRAY(sb->lineno, num + 1);
lineno = sb->lineno;
for (p = buf; p < end; p = get_next_line(p, end))
*lineno++ = p - buf;
*lineno = len;
sb->num_lines = num;
return sb->num_lines;
}
static struct commit *find_single_final(struct rev_info *revs,
const char **name_p)
{
int i;
struct commit *found = NULL;
const char *name = NULL;
for (i = 0; i < revs->pending.nr; i++) {
struct object *obj = revs->pending.objects[i].item;
if (obj->flags & UNINTERESTING)
continue;
obj = deref_tag(revs->repo, obj, NULL, 0);
if (obj->type != OBJ_COMMIT)
die("Non commit %s?", revs->pending.objects[i].name);
if (found)
die("More than one commit to dig from %s and %s?",
revs->pending.objects[i].name, name);
found = (struct commit *)obj;
name = revs->pending.objects[i].name;
}
if (name_p)
*name_p = xstrdup_or_null(name);
return found;
}
static struct commit *dwim_reverse_initial(struct rev_info *revs,
const char **name_p)
{
/*
* DWIM "git blame --reverse ONE -- PATH" as
* "git blame --reverse ONE..HEAD -- PATH" but only do so
* when it makes sense.
*/
struct object *obj;
struct commit *head_commit;
struct object_id head_oid;
if (revs->pending.nr != 1)
return NULL;
/* Is that sole rev a committish? */
obj = revs->pending.objects[0].item;
obj = deref_tag(revs->repo, obj, NULL, 0);
if (obj->type != OBJ_COMMIT)
return NULL;
/* Do we have HEAD? */
if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
return NULL;
head_commit = lookup_commit_reference_gently(revs->repo,
&head_oid, 1);
if (!head_commit)
return NULL;
/* Turn "ONE" into "ONE..HEAD" then */
obj->flags |= UNINTERESTING;
add_pending_object(revs, &head_commit->object, "HEAD");
if (name_p)
*name_p = revs->pending.objects[0].name;
return (struct commit *)obj;
}
static struct commit *find_single_initial(struct rev_info *revs,
const char **name_p)
{
int i;
struct commit *found = NULL;
const char *name = NULL;
/*
* There must be one and only one negative commit, and it must be
* the boundary.
*/
for (i = 0; i < revs->pending.nr; i++) {
struct object *obj = revs->pending.objects[i].item;
if (!(obj->flags & UNINTERESTING))
continue;
obj = deref_tag(revs->repo, obj, NULL, 0);
if (obj->type != OBJ_COMMIT)
die("Non commit %s?", revs->pending.objects[i].name);
if (found)
die("More than one commit to dig up from, %s and %s?",
revs->pending.objects[i].name, name);
found = (struct commit *) obj;
name = revs->pending.objects[i].name;
}
if (!name)
found = dwim_reverse_initial(revs, &name);
if (!name)
die("No commit to dig up from?");
if (name_p)
*name_p = xstrdup(name);
return found;
}
void init_scoreboard(struct blame_scoreboard *sb)
{
memset(sb, 0, sizeof(struct blame_scoreboard));
sb->move_score = BLAME_DEFAULT_MOVE_SCORE;
sb->copy_score = BLAME_DEFAULT_COPY_SCORE;
}
void setup_scoreboard(struct blame_scoreboard *sb,
const char *path,
struct blame_origin **orig)
{
const char *final_commit_name = NULL;
struct blame_origin *o;
struct commit *final_commit = NULL;
enum object_type type;
init_blame_suspects(&blame_suspects);
if (sb->reverse && sb->contents_from)
die(_("--contents and --reverse do not blend well."));
if (!sb->repo)
BUG("repo is NULL");
if (!sb->reverse) {
sb->final = find_single_final(sb->revs, &final_commit_name);
sb->commits.compare = compare_commits_by_commit_date;
} else {
sb->final = find_single_initial(sb->revs, &final_commit_name);
sb->commits.compare = compare_commits_by_reverse_commit_date;
}
if (sb->final && sb->contents_from)
die(_("cannot use --contents with final commit object name"));
if (sb->reverse && sb->revs->first_parent_only)
sb->revs->children.name = NULL;
if (!sb->final) {
/*
* "--not A B -- path" without anything positive;
* do not default to HEAD, but use the working tree
* or "--contents".
*/
setup_work_tree();
sb->final = fake_working_tree_commit(sb->repo,
&sb->revs->diffopt,
path, sb->contents_from);
add_pending_object(sb->revs, &(sb->final->object), ":");
}
if (sb->reverse && sb->revs->first_parent_only) {
final_commit = find_single_final(sb->revs, NULL);
if (!final_commit)
die(_("--reverse and --first-parent together require specified latest commit"));
}
/*
* If we have bottom, this will mark the ancestors of the
* bottom commits we would reach while traversing as
* uninteresting.
*/
if (prepare_revision_walk(sb->revs))
die(_("revision walk setup failed"));
if (sb->reverse && sb->revs->first_parent_only) {
struct commit *c = final_commit;
sb->revs->children.name = "children";
while (c->parents &&
!oideq(&c->object.oid, &sb->final->object.oid)) {
struct commit_list *l = xcalloc(1, sizeof(*l));
l->item = c;
if (add_decoration(&sb->revs->children,
&c->parents->item->object, l))
BUG("not unique item in first-parent chain");
c = c->parents->item;
}
if (!oideq(&c->object.oid, &sb->final->object.oid))
die(_("--reverse --first-parent together require range along first-parent chain"));
}
if (is_null_oid(&sb->final->object.oid)) {
o = get_blame_suspects(sb->final);
sb->final_buf = xmemdupz(o->file.ptr, o->file.size);
sb->final_buf_size = o->file.size;
}
else {
o = get_origin(sb->final, path);
if (fill_blob_sha1_and_mode(sb->repo, o))
die(_("no such path %s in %s"), path, final_commit_name);
if (sb->revs->diffopt.flags.allow_textconv &&
textconv_object(sb->repo, path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,
&sb->final_buf_size))
;
else
sb->final_buf = read_object_file(&o->blob_oid, &type,
&sb->final_buf_size);
if (!sb->final_buf)
die(_("cannot read blob %s for path %s"),
oid_to_hex(&o->blob_oid),
path);
}
sb->num_read_blob++;
prepare_lines(sb);
if (orig)
*orig = o;
free((char *)final_commit_name);
}
struct blame_entry *blame_entry_prepend(struct blame_entry *head,
long start, long end,
struct blame_origin *o)
{
struct blame_entry *new_head = xcalloc(1, sizeof(struct blame_entry));
new_head->lno = start;
new_head->num_lines = end - start;
new_head->suspect = o;
new_head->s_lno = start;
new_head->next = head;
blame_origin_incref(o);
return new_head;
}