+#include "cache.h"
+#include "refs.h"
+#include "cache-tree.h"
+#include "mergesort.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "tag.h"
#include "blame.h"
void blame_origin_decref(struct blame_origin *o)
* get_origin() to obtain shared, refcounted copy instead of calling
* this function directly.
*/
-struct blame_origin *make_origin(struct commit *commit, const char *path)
+static struct blame_origin *make_origin(struct commit *commit, const char *path)
{
struct blame_origin *o;
FLEX_ALLOC_STR(o, path, path);
* Locate an existing origin or create a new one.
* This moves the origin to front position in the commit util list.
*/
-struct blame_origin *get_origin(struct commit *commit, const char *path)
+static struct blame_origin *get_origin(struct commit *commit, const char *path)
{
struct blame_origin *o, *l;
}
return make_origin(commit, path);
}
+
+
+
+static void verify_working_tree_path(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 mode;
+
+ if (!get_tree_entry(commit_oid->hash, path, blob_oid.hash, &mode) &&
+ sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
+ return;
+ }
+
+ pos = cache_name_pos(path, strlen(path));
+ if (pos >= 0)
+ ; /* path is in the index */
+ else if (-1 - pos < active_nr &&
+ !strcmp(active_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 commit_list **tail, const struct object_id *oid)
+{
+ struct commit *parent;
+
+ parent = lookup_commit_reference(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 commit_list **tail)
+{
+ int merge_head;
+ struct strbuf line = STRBUF_INIT;
+
+ merge_head = open(git_path_merge_head(), O_RDONLY);
+ if (merge_head < 0) {
+ if (errno == ENOENT)
+ return;
+ die("cannot open '%s' for reading", git_path_merge_head());
+ }
+
+ 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(), line.buf);
+ tail = append_parent(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 commit *c, struct strbuf *sb)
+{
+ size_t len;
+ void *buf = strbuf_detach(sb, &len);
+ set_commit_buffer(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 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 size, len;
+ struct cache_entry *ce;
+ unsigned mode;
+ struct strbuf msg = STRBUF_INIT;
+
+ read_cache();
+ time(&now);
+ commit = alloc_commit_node();
+ commit->object.parsed = 1;
+ commit->date = now;
+ parent_tail = &commit->parents;
+
+ if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL))
+ die("no such ref: HEAD");
+
+ parent_tail = append_parent(parent_tail, &head_oid);
+ append_merge_parents(parent_tail);
+ verify_working_tree_path(commit, path);
+
+ origin = make_origin(commit, path);
+
+ ident = fmt_ident("Not Committed Yet", "not.committed.yet", 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(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 (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
+ textconv_object(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(&the_index, path, buf.buf, buf.len, &buf, 0);
+ origin->file.ptr = buf.buf;
+ origin->file.size = buf.len;
+ pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_oid.hash);
+
+ /*
+ * 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_cache();
+ read_cache();
+
+ len = strlen(path);
+ if (!mode) {
+ int pos = cache_name_pos(path, len);
+ if (0 <= pos)
+ mode = active_cache[pos]->ce_mode;
+ else
+ /* Let's not bother reading from HEAD tree */
+ mode = S_IFREG | 0644;
+ }
+ size = cache_entry_size(len);
+ ce = xcalloc(1, size);
+ 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_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
+
+ cache_tree_invalidate_path(&the_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 (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
+ textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size))
+ ;
+ else
+ file->ptr = read_sha1_file(o->blob_oid.hash, &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)
+{
+ if (o->file.ptr) {
+ 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 = porigin->commit->util; 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 blame_origin *origin)
+{
+ if (!is_null_oid(&origin->blob_oid))
+ return 0;
+ if (get_tree_entry(origin->commit->object.oid.hash,
+ origin->path,
+ origin->blob_oid.hash, &origin->mode))
+ goto error_out;
+ if (sha1_object_info(origin->blob_oid.hash, 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 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 = parent->util; 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.
+ */
+ diff_setup(&diff_opts);
+ DIFF_OPT_SET(&diff_opts, RECURSIVE);
+ 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(&parent->tree->object.oid, &diff_opts);
+ else
+ diff_tree_oid(&parent->tree->object.oid,
+ &origin->commit->tree->object.oid,
+ "", &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 commit *parent,
+ struct blame_origin *origin)
+{
+ struct blame_origin *porigin = NULL;
+ struct diff_options diff_opts;
+ int i;
+
+ diff_setup(&diff_opts);
+ DIFF_OPT_SET(&diff_opts, RECURSIVE);
+ 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(&parent->tree->object.oid, &diff_opts);
+ else
+ diff_tree_oid(&parent->tree->object.oid,
+ &origin->commit->tree->object.oid,
+ "", &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 this[] 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 this and best_so_far and copying this 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 *this)
+{
+ int i;
+
+ if (!this[1].suspect)
+ return;
+ if (best_so_far[1].suspect) {
+ if (blame_entry_score(sb, &this[1]) < blame_entry_score(sb, &best_so_far[1]))
+ return;
+ }
+
+ for (i = 0; i < 3; i++)
+ blame_origin_incref(this[i].suspect);
+ decref_split(best_so_far);
+ memcpy(best_so_far, this, 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 this[3];
+ tlno += ent->s_lno;
+ same += ent->s_lno;
+ split_overlap(this, ent, tlno, plno, same, parent);
+ copy_split_if_better(sb, split, this);
+ decref_split(this);
+ }
+}
+
+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 */
+
+ diff_setup(&diff_opts);
+ DIFF_OPT_SET(&diff_opts, RECURSIVE);
+ 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_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
+
+ if (is_null_oid(&target->commit->object.oid))
+ do_diff_cache(&parent->tree->object.oid, &diff_opts);
+ else
+ diff_tree_oid(&parent->tree->object.oid,
+ &target->commit->tree->object.oid,
+ "", &diff_opts);
+
+ if (!DIFF_OPT_TST(&diff_opts, 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 this[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, this, &file_p);
+ copy_split_if_better(sb, blame_list[j].split,
+ this);
+ decref_split(this);
+ }
+ 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 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(p, origin);
+ if (!porigin)
+ continue;
+ if (!oidcmp(&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] &&
+ !oidcmp(&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]) {
+ 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 = commit->util;
+
+ /* 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(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(obj, NULL, 0);
+ if (obj->type != OBJ_COMMIT)
+ return NULL;
+
+ /* Do we have HEAD? */
+ if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL))
+ return NULL;
+ head_commit = lookup_commit_reference_gently(&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(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;
+
+ if (sb->reverse && sb->contents_from)
+ die(_("--contents and --reverse do not blend well."));
+
+ 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->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 &&
+ oidcmp(&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))
+ die("BUG: not unique item in first-parent chain");
+ c = c->parents->item;
+ }
+
+ if (oidcmp(&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 = sb->final->util;
+ 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(o))
+ die(_("no such path %s in %s"), path, final_commit_name);
+
+ if (DIFF_OPT_TST(&sb->revs->diffopt, ALLOW_TEXTCONV) &&
+ textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb->final_buf,
+ &sb->final_buf_size))
+ ;
+ else
+ sb->final_buf = read_sha1_file(o->blob_oid.hash, &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;
+}