#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) { 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 = o->commit->util; p; l = p, p = p->next) { if (p == o) { if (l) l->next = p->next; else o->commit->util = 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 = commit->util; commit->util = 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 = commit->util, l = NULL; o; l = o, o = o->next) { if (!strcmp(o->path, path)) { /* bump to front */ if (l) { l->next = o->next; o->next = commit->util; commit->util = o; } return blame_origin_incref(o); } } 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(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(o->file.ptr); o->file.ptr = NULL; } } /* * 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. 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_sha1(parent->tree->object.oid.hash, origin->commit->tree->object.oid.hash, "", &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_sha1(parent->tree->object.oid.hash, origin->commit->tree->object.oid.hash, "", &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_sha1() 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_sha1(parent->tree->object.oid.hash, target->commit->tree->object.oid.hash, "", &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 = 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 = 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; } 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; }