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Diffstat (limited to 'builtin-blame.c')
| -rw-r--r-- | builtin-blame.c | 2520 |
1 files changed, 2520 insertions, 0 deletions
diff --git a/builtin-blame.c b/builtin-blame.c new file mode 100644 index 0000000000..4ea343189f --- /dev/null +++ b/builtin-blame.c @@ -0,0 +1,2520 @@ +/* + * Pickaxe + * + * Copyright (c) 2006, Junio C Hamano + */ + +#include "cache.h" +#include "builtin.h" +#include "blob.h" +#include "commit.h" +#include "tag.h" +#include "tree-walk.h" +#include "diff.h" +#include "diffcore.h" +#include "revision.h" +#include "quote.h" +#include "xdiff-interface.h" +#include "cache-tree.h" +#include "string-list.h" +#include "mailmap.h" +#include "parse-options.h" + +static char blame_usage[] = "git blame [options] [rev-opts] [rev] [--] file"; + +static const char *blame_opt_usage[] = { + blame_usage, + "", + "[rev-opts] are documented in git-rev-list(1)", + NULL +}; + +static int longest_file; +static int longest_author; +static int max_orig_digits; +static int max_digits; +static int max_score_digits; +static int show_root; +static int reverse; +static int blank_boundary; +static int incremental; +static int cmd_is_annotate; +static int xdl_opts = XDF_NEED_MINIMAL; +static struct string_list mailmap; + +#ifndef DEBUG +#define DEBUG 0 +#endif + +/* stats */ +static int num_read_blob; +static int num_get_patch; +static int num_commits; + +#define PICKAXE_BLAME_MOVE 01 +#define PICKAXE_BLAME_COPY 02 +#define PICKAXE_BLAME_COPY_HARDER 04 +#define PICKAXE_BLAME_COPY_HARDEST 010 + +/* + * blame for a blame_entry with score lower than these thresholds + * is not passed to the parent using move/copy logic. + */ +static unsigned blame_move_score; +static unsigned blame_copy_score; +#define BLAME_DEFAULT_MOVE_SCORE 20 +#define BLAME_DEFAULT_COPY_SCORE 40 + +/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */ +#define METAINFO_SHOWN (1u<<12) +#define MORE_THAN_ONE_PATH (1u<<13) + +/* + * One blob in a commit that is being suspected + */ +struct origin { + int refcnt; + struct commit *commit; + mmfile_t file; + unsigned char blob_sha1[20]; + char path[FLEX_ARRAY]; +}; + +/* + * Given an origin, prepare mmfile_t structure to be used by the + * diff machinery + */ +static void fill_origin_blob(struct origin *o, mmfile_t *file) +{ + if (!o->file.ptr) { + enum object_type type; + num_read_blob++; + file->ptr = read_sha1_file(o->blob_sha1, &type, + (unsigned long *)(&(file->size))); + if (!file->ptr) + die("Cannot read blob %s for path %s", + sha1_to_hex(o->blob_sha1), + o->path); + o->file = *file; + } + else + *file = o->file; +} + +/* + * Origin is refcounted and usually we keep the blob contents to be + * reused. + */ +static inline struct origin *origin_incref(struct origin *o) +{ + if (o) + o->refcnt++; + return o; +} + +static void origin_decref(struct origin *o) +{ + if (o && --o->refcnt <= 0) { + free(o->file.ptr); + free(o); + } +} + +static void drop_origin_blob(struct origin *o) +{ + if (o->file.ptr) { + free(o->file.ptr); + o->file.ptr = NULL; + } +} + +/* + * Each group of lines is described by a blame_entry; it can be split + * as we pass blame to the parents. They form a linked list in the + * scoreboard structure, sorted by the target line number. + */ +struct blame_entry { + struct blame_entry *prev; + struct blame_entry *next; + + /* the first line of this group in the final image; + * internally all line numbers are 0 based. + */ + int lno; + + /* how many lines this group has */ + int num_lines; + + /* the commit that introduced this group into the final image */ + struct origin *suspect; + + /* true if the suspect is truly guilty; false while we have not + * checked if the group came from one of its parents. + */ + char guilty; + + /* true if the entry has been scanned for copies in the current parent + */ + char scanned; + + /* the line number of the first line of this group in the + * suspect's file; internally all line numbers are 0 based. + */ + int s_lno; + + /* how significant this entry is -- cached to avoid + * scanning the lines over and over. + */ + unsigned score; +}; + +/* + * The current state of the blame assignment. + */ +struct scoreboard { + /* the final commit (i.e. where we started digging from) */ + struct commit *final; + struct rev_info *revs; + const char *path; + + /* + * The contents in the final image. + * Used by many functions to obtain contents of the nth line, + * indexed with scoreboard.lineno[blame_entry.lno]. + */ + const char *final_buf; + unsigned long final_buf_size; + + /* linked list of blames */ + struct blame_entry *ent; + + /* look-up a line in the final buffer */ + int num_lines; + int *lineno; +}; + +static inline int same_suspect(struct origin *a, struct origin *b) +{ + if (a == b) + return 1; + if (a->commit != b->commit) + return 0; + return !strcmp(a->path, b->path); +} + +static void sanity_check_refcnt(struct scoreboard *); + +/* + * 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. + */ +static void coalesce(struct scoreboard *sb) +{ + struct blame_entry *ent, *next; + + for (ent = sb->ent; ent && (next = ent->next); ent = next) { + if (same_suspect(ent->suspect, next->suspect) && + ent->guilty == next->guilty && + ent->s_lno + ent->num_lines == next->s_lno) { + ent->num_lines += next->num_lines; + ent->next = next->next; + if (ent->next) + ent->next->prev = ent; + origin_decref(next->suspect); + free(next); + ent->score = 0; + next = ent; /* again */ + } + } + + if (DEBUG) /* sanity */ + sanity_check_refcnt(sb); +} + +/* + * 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 origin *make_origin(struct commit *commit, const char *path) +{ + struct origin *o; + o = xcalloc(1, sizeof(*o) + strlen(path) + 1); + o->commit = commit; + o->refcnt = 1; + strcpy(o->path, path); + return o; +} + +/* + * Locate an existing origin or create a new one. + */ +static struct origin *get_origin(struct scoreboard *sb, + struct commit *commit, + const char *path) +{ + struct blame_entry *e; + + for (e = sb->ent; e; e = e->next) { + if (e->suspect->commit == commit && + !strcmp(e->suspect->path, path)) + return origin_incref(e->suspect); + } + return make_origin(commit, path); +} + +/* + * 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. + */ +static int fill_blob_sha1(struct origin *origin) +{ + unsigned mode; + + if (!is_null_sha1(origin->blob_sha1)) + return 0; + if (get_tree_entry(origin->commit->object.sha1, + origin->path, + origin->blob_sha1, &mode)) + goto error_out; + if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB) + goto error_out; + return 0; + error_out: + hashclr(origin->blob_sha1); + 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 origin *find_origin(struct scoreboard *sb, + struct commit *parent, + struct origin *origin) +{ + struct origin *porigin = NULL; + struct diff_options diff_opts; + const char *paths[2]; + + if (parent->util) { + /* + * Each commit object can cache one origin in that + * commit. This is a freestanding copy of origin and + * not refcounted. + */ + struct origin *cached = parent->util; + if (!strcmp(cached->path, origin->path)) { + /* + * The same path between origin and its parent + * without renaming -- the most common case. + */ + porigin = get_origin(sb, parent, cached->path); + + /* + * If the origin was newly created (i.e. get_origin + * would call make_origin if none is found in the + * scoreboard), it does not know the blob_sha1, + * so copy it. Otherwise porigin was in the + * scoreboard and already knows blob_sha1. + */ + if (porigin->refcnt == 1) + hashcpy(porigin->blob_sha1, cached->blob_sha1); + return porigin; + } + /* otherwise it was not very useful; free it */ + free(parent->util); + parent->util = NULL; + } + + /* 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; + + diff_tree_setup_paths(paths, &diff_opts); + if (diff_setup_done(&diff_opts) < 0) + die("diff-setup"); + + if (is_null_sha1(origin->commit->object.sha1)) + do_diff_cache(parent->tree->object.sha1, &diff_opts); + else + diff_tree_sha1(parent->tree->object.sha1, + origin->commit->tree->object.sha1, + "", &diff_opts); + diffcore_std(&diff_opts); + + /* It is either one entry that says "modified", or "created", + * or nothing. + */ + if (!diff_queued_diff.nr) { + /* The path is the same as parent */ + porigin = get_origin(sb, parent, origin->path); + hashcpy(porigin->blob_sha1, origin->blob_sha1); + } + else if (diff_queued_diff.nr != 1) + die("internal error in blame::find_origin"); + else { + struct diff_filepair *p = diff_queued_diff.queue[0]; + switch (p->status) { + default: + die("internal error in blame::find_origin (%c)", + p->status); + case 'M': + porigin = get_origin(sb, parent, origin->path); + hashcpy(porigin->blob_sha1, p->one->sha1); + break; + case 'A': + case 'T': + /* Did not exist in parent, or type changed */ + break; + } + } + diff_flush(&diff_opts); + diff_tree_release_paths(&diff_opts); + if (porigin) { + /* + * Create a freestanding copy that is not part of + * the refcounted origin found in the scoreboard, and + * cache it in the commit. + */ + struct origin *cached; + + cached = make_origin(porigin->commit, porigin->path); + hashcpy(cached->blob_sha1, porigin->blob_sha1); + parent->util = cached; + } + 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 origin *find_rename(struct scoreboard *sb, + struct commit *parent, + struct origin *origin) +{ + struct origin *porigin = NULL; + struct diff_options diff_opts; + int i; + const char *paths[2]; + + 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; + paths[0] = NULL; + diff_tree_setup_paths(paths, &diff_opts); + if (diff_setup_done(&diff_opts) < 0) + die("diff-setup"); + + if (is_null_sha1(origin->commit->object.sha1)) + do_diff_cache(parent->tree->object.sha1, &diff_opts); + else + diff_tree_sha1(parent->tree->object.sha1, + origin->commit->tree->object.sha1, + "", &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(sb, parent, p->one->path); + hashcpy(porigin->blob_sha1, p->one->sha1); + break; + } + } + diff_flush(&diff_opts); + diff_tree_release_paths(&diff_opts); + return porigin; +} + +/* + * Parsing of patch chunks... + */ +struct chunk { + /* line number in postimage; up to but not including this + * line is the same as preimage + */ + int same; + + /* preimage line number after this chunk */ + int p_next; + + /* postimage line number after this chunk */ + int t_next; +}; + +struct patch { + struct chunk *chunks; + int num; +}; + +struct blame_diff_state { + struct xdiff_emit_state xm; + struct patch *ret; + unsigned hunk_post_context; + unsigned hunk_in_pre_context : 1; +}; + +static void process_u_diff(void *state_, char *line, unsigned long len) +{ + struct blame_diff_state *state = state_; + struct chunk *chunk; + int off1, off2, len1, len2, num; + + num = state->ret->num; + if (len < 4 || line[0] != '@' || line[1] != '@') { + if (state->hunk_in_pre_context && line[0] == ' ') + state->ret->chunks[num - 1].same++; + else { + state->hunk_in_pre_context = 0; + if (line[0] == ' ') + state->hunk_post_context++; + else + state->hunk_post_context = 0; + } + return; + } + + if (num && state->hunk_post_context) { + chunk = &state->ret->chunks[num - 1]; + chunk->p_next -= state->hunk_post_context; + chunk->t_next -= state->hunk_post_context; + } + state->ret->num = ++num; + state->ret->chunks = xrealloc(state->ret->chunks, + sizeof(struct chunk) * num); + chunk = &state->ret->chunks[num - 1]; + if (parse_hunk_header(line, len, &off1, &len1, &off2, &len2)) { + state->ret->num--; + return; + } + + /* Line numbers in patch output are one based. */ + off1--; + off2--; + + chunk->same = len2 ? off2 : (off2 + 1); + + chunk->p_next = off1 + (len1 ? len1 : 1); + chunk->t_next = chunk->same + len2; + state->hunk_in_pre_context = 1; + state->hunk_post_context = 0; +} + +static struct patch *compare_buffer(mmfile_t *file_p, mmfile_t *file_o, + int context) +{ + struct blame_diff_state state; + xpparam_t xpp; + xdemitconf_t xecfg; + xdemitcb_t ecb; + + xpp.flags = xdl_opts; + memset(&xecfg, 0, sizeof(xecfg)); + xecfg.ctxlen = context; + ecb.outf = xdiff_outf; + ecb.priv = &state; + memset(&state, 0, sizeof(state)); + state.xm.consume = process_u_diff; + state.ret = xmalloc(sizeof(struct patch)); + state.ret->chunks = NULL; + state.ret->num = 0; + + xdi_diff(file_p, file_o, &xpp, &xecfg, &ecb); + + if (state.ret->num) { + struct chunk *chunk; + chunk = &state.ret->chunks[state.ret->num - 1]; + chunk->p_next -= state.hunk_post_context; + chunk->t_next -= state.hunk_post_context; + } + return state.ret; +} + +/* + * Run diff between two origins and grab the patch output, so that + * we can pass blame for lines origin is currently suspected for + * to its parent. + */ +static struct patch *get_patch(struct origin *parent, struct origin *origin) +{ + mmfile_t file_p, file_o; + struct patch *patch; + + fill_origin_blob(parent, &file_p); + fill_origin_blob(origin, &file_o); + if (!file_p.ptr || !file_o.ptr) + return NULL; + patch = compare_buffer(&file_p, &file_o, 0); + num_get_patch++; + return patch; +} + +static void free_patch(struct patch *p) +{ + free(p->chunks); + free(p); +} + +/* + * Link in a new blame entry to the scoreboard. Entries that cover the + * same line range have been removed from the scoreboard previously. + */ +static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e) +{ + struct blame_entry *ent, *prev = NULL; + + origin_incref(e->suspect); + + for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next) + prev = ent; + + /* prev, if not NULL, is the last one that is below e */ + e->prev = prev; + if (prev) { + e->next = prev->next; + prev->next = e; + } + else { + e->next = sb->ent; + sb->ent = e; + } + if (e->next) + e->next->prev = e; +} + +/* + * src typically is on-stack; we want to copy the information in it to + * a malloced blame_entry that is already on the linked list of the + * scoreboard. The origin of dst loses a refcnt while the origin of src + * gains one. + */ +static void dup_entry(struct blame_entry *dst, struct blame_entry *src) +{ + struct blame_entry *p, *n; + + p = dst->prev; + n = dst->next; + origin_incref(src->suspect); + origin_decref(dst->suspect); + memcpy(dst, src, sizeof(*src)); + dst->prev = p; + dst->next = n; + dst->score = 0; +} + +static const char *nth_line(struct scoreboard *sb, int 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 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 = 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 = 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 = origin_incref(parent); +} + +/* + * split_overlap() divided an existing blame e into up to three parts + * in split. Adjust the linked list of blames in the scoreboard to + * reflect the split. + */ +static void split_blame(struct scoreboard *sb, + struct blame_entry *split, + struct blame_entry *e) +{ + struct blame_entry *new_entry; + + if (split[0].suspect && split[2].suspect) { + /* The first part (reuse storage for the existing entry e) */ + dup_entry(e, &split[0]); + + /* The last part -- me */ + new_entry = xmalloc(sizeof(*new_entry)); + memcpy(new_entry, &(split[2]), sizeof(struct blame_entry)); + add_blame_entry(sb, new_entry); + + /* ... and the middle part -- parent */ + new_entry = xmalloc(sizeof(*new_entry)); + memcpy(new_entry, &(split[1]), sizeof(struct blame_entry)); + add_blame_entry(sb, new_entry); + } + 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(e, &split[1]); + else if (split[0].suspect) { + /* me and then parent */ + dup_entry(e, &split[0]); + + new_entry = xmalloc(sizeof(*new_entry)); + memcpy(new_entry, &(split[1]), sizeof(struct blame_entry)); + add_blame_entry(sb, new_entry); + } + else { + /* parent and then me */ + dup_entry(e, &split[1]); + + new_entry = xmalloc(sizeof(*new_entry)); + memcpy(new_entry, &(split[2]), sizeof(struct blame_entry)); + add_blame_entry(sb, new_entry); + } + + if (DEBUG) { /* sanity */ + struct blame_entry *ent; + int lno = sb->ent->lno, corrupt = 0; + + for (ent = sb->ent; ent; ent = ent->next) { + if (lno != ent->lno) + corrupt = 1; + if (ent->s_lno < 0) + corrupt = 1; + lno += ent->num_lines; + } + if (corrupt) { + lno = sb->ent->lno; + for (ent = sb->ent; ent; ent = ent->next) { + printf("L %8d l %8d n %8d\n", + lno, ent->lno, ent->num_lines); + lno = ent->lno + ent->num_lines; + } + die("oops"); + } + } +} + +/* + * 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++) + origin_decref(split[i].suspect); +} + +/* + * Helper for blame_chunk(). blame_entry e is known to overlap with + * the patch hunk; split it and pass blame to the parent. + */ +static void blame_overlap(struct scoreboard *sb, struct blame_entry *e, + int tlno, int plno, int same, + struct origin *parent) +{ + struct blame_entry split[3]; + + split_overlap(split, e, tlno, plno, same, parent); + if (split[1].suspect) + split_blame(sb, split, e); + decref_split(split); +} + +/* + * Find the line number of the last line the target is suspected for. + */ +static int find_last_in_target(struct scoreboard *sb, struct origin *target) +{ + struct blame_entry *e; + int last_in_target = -1; + + for (e = sb->ent; e; e = e->next) { + if (e->guilty || !same_suspect(e->suspect, target)) + continue; + if (last_in_target < e->s_lno + e->num_lines) + last_in_target = e->s_lno + e->num_lines; + } + return last_in_target; +} + +/* + * Process one hunk from the patch between the current suspect for + * blame_entry e and its parent. Find and split the overlap, and + * pass blame to the overlapping part to the parent. + */ +static void blame_chunk(struct scoreboard *sb, + int tlno, int plno, int same, + struct origin *target, struct origin *parent) +{ + struct blame_entry *e; + + for (e = sb->ent; e; e = e->next) { + if (e->guilty || !same_suspect(e->suspect, target)) + continue; + if (same <= e->s_lno) + continue; + if (tlno < e->s_lno + e->num_lines) + blame_overlap(sb, e, tlno, plno, same, parent); + } +} + +/* + * 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 int pass_blame_to_parent(struct scoreboard *sb, + struct origin *target, + struct origin *parent) +{ + int i, last_in_target, plno, tlno; + struct patch *patch; + + last_in_target = find_last_in_target(sb, target); + if (last_in_target < 0) + return 1; /* nothing remains for this target */ + + patch = get_patch(parent, target); + plno = tlno = 0; + for (i = 0; i < patch->num; i++) { + struct chunk *chunk = &patch->chunks[i]; + + blame_chunk(sb, tlno, plno, chunk->same, target, parent); + plno = chunk->p_next; + tlno = chunk->t_next; + } + /* The rest (i.e. anything after tlno) are the same as the parent */ + blame_chunk(sb, tlno, plno, last_in_target, target, parent); + + free_patch(patch); + return 0; +} + +/* + * 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. + */ +static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e) +{ + unsigned score; + const char *cp, *ep; + + if (e->score) + return e->score; + + score = 1; + cp = nth_line(sb, e->lno); + ep = 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 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 (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1])) + return; + } + + for (i = 0; i < 3; i++) + 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 scoreboard *sb, + struct blame_entry *ent, + int tlno, int plno, int same, + struct 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); + } +} + +/* + * 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 scoreboard *sb, + struct blame_entry *ent, + struct origin *parent, + struct blame_entry *split, + mmfile_t *file_p) +{ + const char *cp; + int cnt; + mmfile_t file_o; + struct patch *patch; + int i, plno, tlno; + + /* + * Prepare mmfile that contains only the lines in ent. + */ + cp = nth_line(sb, ent->lno); + file_o.ptr = (char*) cp; + cnt = ent->num_lines; + + while (cnt && cp < sb->final_buf + sb->final_buf_size) { + if (*cp++ == '\n') + cnt--; + } + file_o.size = cp - file_o.ptr; + + patch = compare_buffer(file_p, &file_o, 1); + + /* + * 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])); + plno = tlno = 0; + for (i = 0; i < patch->num; i++) { + struct chunk *chunk = &patch->chunks[i]; + + handle_split(sb, ent, tlno, plno, chunk->same, parent, split); + plno = chunk->p_next; + tlno = chunk->t_next; + } + /* remainder, if any, all match the preimage */ + handle_split(sb, ent, tlno, plno, ent->num_lines, parent, split); + free_patch(patch); +} + +/* + * See if lines currently target is suspected for can be attributed to + * parent. + */ +static int find_move_in_parent(struct scoreboard *sb, + struct origin *target, + struct origin *parent) +{ + int last_in_target, made_progress; + struct blame_entry *e, split[3]; + mmfile_t file_p; + + last_in_target = find_last_in_target(sb, target); + if (last_in_target < 0) + return 1; /* nothing remains for this target */ + + fill_origin_blob(parent, &file_p); + if (!file_p.ptr) + return 0; + + made_progress = 1; + while (made_progress) { + made_progress = 0; + for (e = sb->ent; e; e = e->next) { + if (e->guilty || !same_suspect(e->suspect, target) || + ent_score(sb, e) < blame_move_score) + continue; + find_copy_in_blob(sb, e, parent, split, &file_p); + if (split[1].suspect && + blame_move_score < ent_score(sb, &split[1])) { + split_blame(sb, split, e); + made_progress = 1; + } + decref_split(split); + } + } + return 0; +} + +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 scoreboard *sb, + struct origin *target, + int min_score, + int *num_ents_p) +{ + struct blame_entry *e; + int num_ents, i; + struct blame_list *blame_list = NULL; + + for (e = sb->ent, num_ents = 0; e; e = e->next) + if (!e->scanned && !e->guilty && + same_suspect(e->suspect, target) && + min_score < ent_score(sb, e)) + num_ents++; + if (num_ents) { + blame_list = xcalloc(num_ents, sizeof(struct blame_list)); + for (e = sb->ent, i = 0; e; e = e->next) + if (!e->scanned && !e->guilty && + same_suspect(e->suspect, target) && + min_score < ent_score(sb, e)) + blame_list[i++].ent = e; + } + *num_ents_p = num_ents; + return blame_list; +} + +/* + * Reset the scanned status on all entries. + */ +static void reset_scanned_flag(struct scoreboard *sb) +{ + struct blame_entry *e; + for (e = sb->ent; e; e = e->next) + e->scanned = 0; +} + +/* + * 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 int find_copy_in_parent(struct scoreboard *sb, + struct origin *target, + struct commit *parent, + struct origin *porigin, + int opt) +{ + struct diff_options diff_opts; + const char *paths[1]; + int i, j; + int retval; + struct blame_list *blame_list; + int num_ents; + + blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents); + if (!blame_list) + return 1; /* nothing remains for this target */ + + diff_setup(&diff_opts); + DIFF_OPT_SET(&diff_opts, RECURSIVE); + diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT; + + paths[0] = NULL; + diff_tree_setup_paths(paths, &diff_opts); + if (diff_setup_done(&diff_opts) < 0) + die("diff-setup"); + + /* 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_sha1(target->commit->object.sha1)) + do_diff_cache(parent->tree->object.sha1, &diff_opts); + else + diff_tree_sha1(parent->tree->object.sha1, + target->commit->tree->object.sha1, + "", &diff_opts); + + if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER)) + diffcore_std(&diff_opts); + + retval = 0; + while (1) { + int made_progress = 0; + + for (i = 0; i < diff_queued_diff.nr; i++) { + struct diff_filepair *p = diff_queued_diff.queue[i]; + struct origin *norigin; + mmfile_t file_p; + struct blame_entry this[3]; + + if (!DIFF_FILE_VALID(p->one)) + continue; /* does not exist in parent */ + if (porigin && !strcmp(p->one->path, porigin->path)) + /* find_move already dealt with this path */ + continue; + + norigin = get_origin(sb, parent, p->one->path); + hashcpy(norigin->blob_sha1, p->one->sha1); + fill_origin_blob(norigin, &file_p); + 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); + } + origin_decref(norigin); + } + + for (j = 0; j < num_ents; j++) { + struct blame_entry *split = blame_list[j].split; + if (split[1].suspect && + blame_copy_score < ent_score(sb, &split[1])) { + split_blame(sb, split, blame_list[j].ent); + made_progress = 1; + } + else + blame_list[j].ent->scanned = 1; + decref_split(split); + } + free(blame_list); + + if (!made_progress) + break; + blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents); + if (!blame_list) { + retval = 1; + break; + } + } + reset_scanned_flag(sb); + diff_flush(&diff_opts); + diff_tree_release_paths(&diff_opts); + return retval; +} + +/* + * 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 scoreboard *sb, + struct origin *origin, struct origin *porigin) +{ + struct blame_entry *e; + + if (!porigin->file.ptr && origin->file.ptr) { + /* Steal its file */ + porigin->file = origin->file; + origin->file.ptr = NULL; + } + for (e = sb->ent; e; e = e->next) { + if (!same_suspect(e->suspect, origin)) + continue; + origin_incref(porigin); + origin_decref(e->suspect); + e->suspect = porigin; + } +} + +/* + * 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) +{ + if (!reverse) + return commit->parents; + return lookup_decoration(&revs->children, &commit->object); +} + +static int num_scapegoats(struct rev_info *revs, struct commit *commit) +{ + int cnt; + struct commit_list *l = first_scapegoat(revs, commit); + for (cnt = 0; l; l = l->next) + cnt++; + return cnt; +} + +#define MAXSG 16 + +static void pass_blame(struct scoreboard *sb, struct 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 origin *sg_buf[MAXSG]; + struct origin *porigin, **sg_origin = sg_buf; + + num_sg = num_scapegoats(revs, commit); + 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; pass++) { + struct origin *(*find)(struct scoreboard *, + struct commit *, struct origin *); + find = pass ? find_rename : find_origin; + + for (i = 0, sg = first_scapegoat(revs, commit); + i < num_sg && sg; + sg = sg->next, i++) { + struct commit *p = sg->item; + int j, same; + + if (sg_origin[i]) + continue; + if (parse_commit(p)) + continue; + porigin = find(sb, p, origin); + if (!porigin) + continue; + if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) { + pass_whole_blame(sb, origin, porigin); + origin_decref(porigin); + goto finish; + } + for (j = same = 0; j < i; j++) + if (sg_origin[j] && + !hashcmp(sg_origin[j]->blob_sha1, + porigin->blob_sha1)) { + same = 1; + break; + } + if (!same) + sg_origin[i] = porigin; + else + origin_decref(porigin); + } + } + + num_commits++; + for (i = 0, sg = first_scapegoat(revs, commit); + i < num_sg && sg; + sg = sg->next, i++) { + struct origin *porigin = sg_origin[i]; + if (!porigin) + continue; + if (pass_blame_to_parent(sb, origin, porigin)) + goto finish; + } + + /* + * Optionally find moves in parents' files. + */ + if (opt & PICKAXE_BLAME_MOVE) + for (i = 0, sg = first_scapegoat(revs, commit); + i < num_sg && sg; + sg = sg->next, i++) { + struct origin *porigin = sg_origin[i]; + if (!porigin) + continue; + if (find_move_in_parent(sb, origin, porigin)) + goto finish; + } + + /* + * Optionally find copies from parents' files. + */ + if (opt & PICKAXE_BLAME_COPY) + for (i = 0, sg = first_scapegoat(revs, commit); + i < num_sg && sg; + sg = sg->next, i++) { + struct origin *porigin = sg_origin[i]; + if (find_copy_in_parent(sb, origin, sg->item, + porigin, opt)) + goto finish; + } + + finish: + for (i = 0; i < num_sg; i++) { + if (sg_origin[i]) { + drop_origin_blob(sg_origin[i]); + origin_decref(sg_origin[i]); + } + } + drop_origin_blob(origin); + if (sg_buf != sg_origin) + free(sg_origin); +} + +/* + * Information on commits, used for output. + */ +struct commit_info +{ + const char *author; + const char *author_mail; + unsigned long author_time; + const char *author_tz; + + /* filled only when asked for details */ + const char *committer; + const char *committer_mail; + unsigned long committer_time; + const char *committer_tz; + + const char *summary; +}; + +/* + * Parse author/committer line in the commit object buffer + */ +static void get_ac_line(const char *inbuf, const char *what, + int bufsz, char *person, const char **mail, + unsigned long *time, const char **tz) +{ + int len, tzlen, maillen; + char *tmp, *endp, *timepos; + + tmp = strstr(inbuf, what); + if (!tmp) + goto error_out; + tmp += strlen(what); + endp = strchr(tmp, '\n'); + if (!endp) + len = strlen(tmp); + else + len = endp - tmp; + if (bufsz <= len) { + error_out: + /* Ugh */ + *mail = *tz = "(unknown)"; + *time = 0; + return; + } + memcpy(person, tmp, len); + + tmp = person; + tmp += len; + *tmp = 0; + while (*tmp != ' ') + tmp--; + *tz = tmp+1; + tzlen = (person+len)-(tmp+1); + + *tmp = 0; + while (*tmp != ' ') + tmp--; + *time = strtoul(tmp, NULL, 10); + timepos = tmp; + + *tmp = 0; + while (*tmp != ' ') + tmp--; + *mail = tmp + 1; + *tmp = 0; + maillen = timepos - tmp; + + if (!mailmap.nr) + return; + + /* + * mailmap expansion may make the name longer. + * make room by pushing stuff down. + */ + tmp = person + bufsz - (tzlen + 1); + memmove(tmp, *tz, tzlen); + tmp[tzlen] = 0; + *tz = tmp; + + tmp = tmp - (maillen + 1); + memmove(tmp, *mail, maillen); + tmp[maillen] = 0; + *mail = tmp; + + /* + * Now, convert e-mail using mailmap + */ + map_email(&mailmap, tmp + 1, person, tmp-person-1); +} + +static void get_commit_info(struct commit *commit, + struct commit_info *ret, + int detailed) +{ + int len; + char *tmp, *endp; + static char author_buf[1024]; + static char committer_buf[1024]; + static char summary_buf[1024]; + + /* + * We've operated without save_commit_buffer, so + * we now need to populate them for output. + */ + if (!commit->buffer) { + enum object_type type; + unsigned long size; + commit->buffer = + read_sha1_file(commit->object.sha1, &type, &size); + if (!commit->buffer) + die("Cannot read commit %s", + sha1_to_hex(commit->object.sha1)); + } + ret->author = author_buf; + get_ac_line(commit->buffer, "\nauthor ", + sizeof(author_buf), author_buf, &ret->author_mail, + &ret->author_time, &ret->author_tz); + + if (!detailed) + return; + + ret->committer = committer_buf; + get_ac_line(commit->buffer, "\ncommitter ", + sizeof(committer_buf), committer_buf, &ret->committer_mail, + &ret->committer_time, &ret->committer_tz); + + ret->summary = summary_buf; + tmp = strstr(commit->buffer, "\n\n"); + if (!tmp) { + error_out: + sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1)); + return; + } + tmp += 2; + endp = strchr(tmp, '\n'); + if (!endp) + endp = tmp + strlen(tmp); + len = endp - tmp; + if (len >= sizeof(summary_buf) || len == 0) + goto error_out; + memcpy(summary_buf, tmp, len); + summary_buf[len] = 0; +} + +/* + * To allow LF and other nonportable characters in pathnames, + * they are c-style quoted as needed. + */ +static void write_filename_info(const char *path) +{ + printf("filename "); + write_name_quoted(path, stdout, '\n'); +} + +/* + * The blame_entry is found to be guilty for the range. Mark it + * as such, and show it in incremental output. + */ +static void found_guilty_entry(struct blame_entry *ent) +{ + if (ent->guilty) + return; + ent->guilty = 1; + if (incremental) { + struct origin *suspect = ent->suspect; + + printf("%s %d %d %d\n", + sha1_to_hex(suspect->commit->object.sha1), + ent->s_lno + 1, ent->lno + 1, ent->num_lines); + if (!(suspect->commit->object.flags & METAINFO_SHOWN)) { + struct commit_info ci; + suspect->commit->object.flags |= METAINFO_SHOWN; + get_commit_info(suspect->commit, &ci, 1); + printf("author %s\n", ci.author); + printf("author-mail %s\n", ci.author_mail); + printf("author-time %lu\n", ci.author_time); + printf("author-tz %s\n", ci.author_tz); + printf("committer %s\n", ci.committer); + printf("committer-mail %s\n", ci.committer_mail); + printf("committer-time %lu\n", ci.committer_time); + printf("committer-tz %s\n", ci.committer_tz); + printf("summary %s\n", ci.summary); + if (suspect->commit->object.flags & UNINTERESTING) + printf("boundary\n"); + } + write_filename_info(suspect->path); + maybe_flush_or_die(stdout, "stdout"); + } +} + +/* + * The main loop -- while the scoreboard has lines whose true origin + * is still unknown, pick one blame_entry, and allow its current + * suspect to pass blames to its parents. + */ +static void assign_blame(struct scoreboard *sb, int opt) +{ + struct rev_info *revs = sb->revs; + + while (1) { + struct blame_entry *ent; + struct commit *commit; + struct origin *suspect = NULL; + + /* find one suspect to break down */ + for (ent = sb->ent; !suspect && ent; ent = ent->next) + if (!ent->guilty) + suspect = ent->suspect; + if (!suspect) + return; /* all done */ + + /* + * We will use this suspect later in the loop, + * so hold onto it in the meantime. + */ + origin_incref(suspect); + commit = suspect->commit; + if (!commit->object.parsed) + parse_commit(commit); + if (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 && !show_root) + commit->object.flags |= UNINTERESTING; + + /* Take responsibility for the remaining entries */ + for (ent = sb->ent; ent; ent = ent->next) + if (same_suspect(ent->suspect, suspect)) + found_guilty_entry(ent); + origin_decref(suspect); + + if (DEBUG) /* sanity */ + sanity_check_refcnt(sb); + } +} + +static const char *format_time(unsigned long time, const char *tz_str, + int show_raw_time) +{ + static char time_buf[128]; + time_t t = time; + int minutes, tz; + struct tm *tm; + + if (show_raw_time) { + sprintf(time_buf, "%lu %s", time, tz_str); + return time_buf; + } + + tz = atoi(tz_str); + minutes = tz < 0 ? -tz : tz; + minutes = (minutes / 100)*60 + (minutes % 100); + minutes = tz < 0 ? -minutes : minutes; + t = time + minutes * 60; + tm = gmtime(&t); + + strftime(time_buf, sizeof(time_buf), "%Y-%m-%d %H:%M:%S ", tm); + strcat(time_buf, tz_str); + return time_buf; +} + +#define OUTPUT_ANNOTATE_COMPAT 001 +#define OUTPUT_LONG_OBJECT_NAME 002 +#define OUTPUT_RAW_TIMESTAMP 004 +#define OUTPUT_PORCELAIN 010 +#define OUTPUT_SHOW_NAME 020 +#define OUTPUT_SHOW_NUMBER 040 +#define OUTPUT_SHOW_SCORE 0100 +#define OUTPUT_NO_AUTHOR 0200 + +static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent) +{ + int cnt; + const char *cp; + struct origin *suspect = ent->suspect; + char hex[41]; + + strcpy(hex, sha1_to_hex(suspect->commit->object.sha1)); + printf("%s%c%d %d %d\n", + hex, + ent->guilty ? ' ' : '*', // purely for debugging + ent->s_lno + 1, + ent->lno + 1, + ent->num_lines); + if (!(suspect->commit->object.flags & METAINFO_SHOWN)) { + struct commit_info ci; + suspect->commit->object.flags |= METAINFO_SHOWN; + get_commit_info(suspect->commit, &ci, 1); + printf("author %s\n", ci.author); + printf("author-mail %s\n", ci.author_mail); + printf("author-time %lu\n", ci.author_time); + printf("author-tz %s\n", ci.author_tz); + printf("committer %s\n", ci.committer); + printf("committer-mail %s\n", ci.committer_mail); + printf("committer-time %lu\n", ci.committer_time); + printf("committer-tz %s\n", ci.committer_tz); + write_filename_info(suspect->path); + printf("summary %s\n", ci.summary); + if (suspect->commit->object.flags & UNINTERESTING) + printf("boundary\n"); + } + else if (suspect->commit->object.flags & MORE_THAN_ONE_PATH) + write_filename_info(suspect->path); + + cp = nth_line(sb, ent->lno); + for (cnt = 0; cnt < ent->num_lines; cnt++) { + char ch; + if (cnt) + printf("%s %d %d\n", hex, + ent->s_lno + 1 + cnt, + ent->lno + 1 + cnt); + putchar('\t'); + do { + ch = *cp++; + putchar(ch); + } while (ch != '\n' && + cp < sb->final_buf + sb->final_buf_size); + } +} + +static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt) +{ + int cnt; + const char *cp; + struct origin *suspect = ent->suspect; + struct commit_info ci; + char hex[41]; + int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP); + + get_commit_info(suspect->commit, &ci, 1); + strcpy(hex, sha1_to_hex(suspect->commit->object.sha1)); + + cp = nth_line(sb, ent->lno); + for (cnt = 0; cnt < ent->num_lines; cnt++) { + char ch; + int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8; + + if (suspect->commit->object.flags & UNINTERESTING) { + if (blank_boundary) + memset(hex, ' ', length); + else if (!cmd_is_annotate) { + length--; + putchar('^'); + } + } + + printf("%.*s", length, hex); + if (opt & OUTPUT_ANNOTATE_COMPAT) + printf("\t(%10s\t%10s\t%d)", ci.author, + format_time(ci.author_time, ci.author_tz, + show_raw_time), + ent->lno + 1 + cnt); + else { + if (opt & OUTPUT_SHOW_SCORE) + printf(" %*d %02d", + max_score_digits, ent->score, + ent->suspect->refcnt); + if (opt & OUTPUT_SHOW_NAME) + printf(" %-*.*s", longest_file, longest_file, + suspect->path); + if (opt & OUTPUT_SHOW_NUMBER) + printf(" %*d", max_orig_digits, + ent->s_lno + 1 + cnt); + + if (!(opt & OUTPUT_NO_AUTHOR)) + printf(" (%-*.*s %10s", + longest_author, longest_author, + ci.author, + format_time(ci.author_time, + ci.author_tz, + show_raw_time)); + printf(" %*d) ", + max_digits, ent->lno + 1 + cnt); + } + do { + ch = *cp++; + putchar(ch); + } while (ch != '\n' && + cp < sb->final_buf + sb->final_buf_size); + } +} + +static void output(struct scoreboard *sb, int option) +{ + struct blame_entry *ent; + + if (option & OUTPUT_PORCELAIN) { + for (ent = sb->ent; ent; ent = ent->next) { + struct blame_entry *oth; + struct origin *suspect = ent->suspect; + struct commit *commit = suspect->commit; + if (commit->object.flags & MORE_THAN_ONE_PATH) + continue; + for (oth = ent->next; oth; oth = oth->next) { + if ((oth->suspect->commit != commit) || + !strcmp(oth->suspect->path, suspect->path)) + continue; + commit->object.flags |= MORE_THAN_ONE_PATH; + break; + } + } + } + + for (ent = sb->ent; ent; ent = ent->next) { + if (option & OUTPUT_PORCELAIN) + emit_porcelain(sb, ent); + else { + emit_other(sb, ent, option); + } + } +} + +/* + * 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 scoreboard *sb) +{ + const char *buf = sb->final_buf; + unsigned long len = sb->final_buf_size; + int num = 0, incomplete = 0, bol = 1; + + if (len && buf[len-1] != '\n') + incomplete++; /* incomplete line at the end */ + while (len--) { + if (bol) { + sb->lineno = xrealloc(sb->lineno, + sizeof(int* ) * (num + 1)); + sb->lineno[num] = buf - sb->final_buf; + bol = 0; + } + if (*buf++ == '\n') { + num++; + bol = 1; + } + } + sb->lineno = xrealloc(sb->lineno, + sizeof(int* ) * (num + incomplete + 1)); + sb->lineno[num + incomplete] = buf - sb->final_buf; + sb->num_lines = num + incomplete; + return sb->num_lines; +} + +/* + * Add phony grafts for use with -S; this is primarily to + * support git-cvsserver that wants to give a linear history + * to its clients. + */ +static int read_ancestry(const char *graft_file) +{ + FILE *fp = fopen(graft_file, "r"); + char buf[1024]; + if (!fp) + return -1; + while (fgets(buf, sizeof(buf), fp)) { + /* The format is just "Commit Parent1 Parent2 ...\n" */ + int len = strlen(buf); + struct commit_graft *graft = read_graft_line(buf, len); + if (graft) + register_commit_graft(graft, 0); + } + fclose(fp); + return 0; +} + +/* + * How many columns do we need to show line numbers in decimal? + */ +static int lineno_width(int lines) +{ + int i, width; + + for (width = 1, i = 10; i <= lines + 1; width++) + i *= 10; + return width; +} + +/* + * How many columns do we need to show line numbers, authors, + * and filenames? + */ +static void find_alignment(struct scoreboard *sb, int *option) +{ + int longest_src_lines = 0; + int longest_dst_lines = 0; + unsigned largest_score = 0; + struct blame_entry *e; + + for (e = sb->ent; e; e = e->next) { + struct origin *suspect = e->suspect; + struct commit_info ci; + int num; + + if (strcmp(suspect->path, sb->path)) + *option |= OUTPUT_SHOW_NAME; + num = strlen(suspect->path); + if (longest_file < num) + longest_file = num; + if (!(suspect->commit->object.flags & METAINFO_SHOWN)) { + suspect->commit->object.flags |= METAINFO_SHOWN; + get_commit_info(suspect->commit, &ci, 1); + num = strlen(ci.author); + if (longest_author < num) + longest_author = num; + } + num = e->s_lno + e->num_lines; + if (longest_src_lines < num) + longest_src_lines = num; + num = e->lno + e->num_lines; + if (longest_dst_lines < num) + longest_dst_lines = num; + if (largest_score < ent_score(sb, e)) + largest_score = ent_score(sb, e); + } + max_orig_digits = lineno_width(longest_src_lines); + max_digits = lineno_width(longest_dst_lines); + max_score_digits = lineno_width(largest_score); +} + +/* + * For debugging -- origin is refcounted, and this asserts that + * we do not underflow. + */ +static void sanity_check_refcnt(struct 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, + sha1_to_hex(ent->suspect->commit->object.sha1), + ent->suspect->refcnt); + baa = 1; + } + } + for (ent = sb->ent; ent; ent = ent->next) { + /* Mark the ones that haven't been checked */ + if (0 < ent->suspect->refcnt) + ent->suspect->refcnt = -ent->suspect->refcnt; + } + for (ent = sb->ent; ent; ent = ent->next) { + /* + * ... then pick each and see if they have the the + * correct refcnt. + */ + int found; + struct blame_entry *e; + struct origin *suspect = ent->suspect; + + if (0 < suspect->refcnt) + continue; + suspect->refcnt = -suspect->refcnt; /* Unmark */ + for (found = 0, e = sb->ent; e; e = e->next) { + if (e->suspect != suspect) + continue; + found++; + } + if (suspect->refcnt != found) { + fprintf(stderr, "%s in %s has refcnt %d, not %d\n", + ent->suspect->path, + sha1_to_hex(ent->suspect->commit->object.sha1), + ent->suspect->refcnt, found); + baa = 2; + } + } + if (baa) { + int opt = 0160; + find_alignment(sb, &opt); + output(sb, opt); + die("Baa %d!", baa); + } +} + +/* + * Used for the command line parsing; check if the path exists + * in the working tree. + */ +static int has_string_in_work_tree(const char *path) +{ + struct stat st; + return !lstat(path, &st); +} + +static unsigned parse_score(const char *arg) +{ + char *end; + unsigned long score = strtoul(arg, &end, 10); + if (*end) + return 0; + return score; +} + +static const char *add_prefix(const char *prefix, const char *path) +{ + return prefix_path(prefix, prefix ? strlen(prefix) : 0, path); +} + +/* + * Parsing of (comma separated) one item in the -L option + */ +static const char *parse_loc(const char *spec, + struct scoreboard *sb, long lno, + long begin, long *ret) +{ + char *term; + const char *line; + long num; + int reg_error; + regex_t regexp; + regmatch_t match[1]; + + /* Allow "-L <something>,+20" to mean starting at <something> + * for 20 lines, or "-L <something>,-5" for 5 lines ending at + * <something>. + */ + if (1 < begin && (spec[0] == '+' || spec[0] == '-')) { + num = strtol(spec + 1, &term, 10); + if (term != spec + 1) { + if (spec[0] == '-') + num = 0 - num; + if (0 < num) + *ret = begin + num - 2; + else if (!num) + *ret = begin; + else + *ret = begin + num; + return term; + } + return spec; + } + num = strtol(spec, &term, 10); + if (term != spec) { + *ret = num; + return term; + } + if (spec[0] != '/') + return spec; + + /* it could be a regexp of form /.../ */ + for (term = (char*) spec + 1; *term && *term != '/'; term++) { + if (*term == '\\') + term++; + } + if (*term != '/') + return spec; + + /* try [spec+1 .. term-1] as regexp */ + *term = 0; + begin--; /* input is in human terms */ + line = nth_line(sb, begin); + + if (!(reg_error = regcomp(®exp, spec + 1, REG_NEWLINE)) && + !(reg_error = regexec(®exp, line, 1, match, 0))) { + const char *cp = line + match[0].rm_so; + const char *nline; + + while (begin++ < lno) { + nline = nth_line(sb, begin); + if (line <= cp && cp < nline) + break; + line = nline; + } + *ret = begin; + regfree(®exp); + *term++ = '/'; + return term; + } + else { + char errbuf[1024]; + regerror(reg_error, ®exp, errbuf, 1024); + die("-L parameter '%s': %s", spec + 1, errbuf); + } +} + +/* + * Parsing of -L option + */ +static void prepare_blame_range(struct scoreboard *sb, + const char *bottomtop, + long lno, + long *bottom, long *top) +{ + const char *term; + + term = parse_loc(bottomtop, sb, lno, 1, bottom); + if (*term == ',') { + term = parse_loc(term + 1, sb, lno, *bottom + 1, top); + if (*term) + usage(blame_usage); + } + if (*term) + usage(blame_usage); +} + +static int git_blame_config(const char *var, const char *value, void *cb) +{ + if (!strcmp(var, "blame.showroot")) { + show_root = git_config_bool(var, value); + return 0; + } + if (!strcmp(var, "blame.blankboundary")) { + blank_boundary = git_config_bool(var, value); + return 0; + } + return git_default_config(var, value, cb); +} + +/* + * 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(const char *path, const char *contents_from) +{ + struct commit *commit; + struct origin *origin; + unsigned char head_sha1[20]; + struct strbuf buf; + const char *ident; + time_t now; + int size, len; + struct cache_entry *ce; + unsigned mode; + + if (get_sha1("HEAD", head_sha1)) + die("No such ref: HEAD"); + + time(&now); + commit = xcalloc(1, sizeof(*commit)); + commit->parents = xcalloc(1, sizeof(*commit->parents)); + commit->parents->item = lookup_commit_reference(head_sha1); + commit->object.parsed = 1; + commit->date = now; + commit->object.type = OBJ_COMMIT; + + origin = make_origin(commit, path); + + strbuf_init(&buf, 0); + if (!contents_from || strcmp("-", contents_from)) { + struct stat st; + const char *read_from; + unsigned long fin_size; + + if (contents_from) { + if (stat(contents_from, &st) < 0) + die("Cannot stat %s", contents_from); + read_from = contents_from; + } + else { + if (lstat(path, &st) < 0) + die("Cannot lstat %s", path); + read_from = path; + } + fin_size = xsize_t(st.st_size); + mode = canon_mode(st.st_mode); + switch (st.st_mode & S_IFMT) { + case S_IFREG: + if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size) + die("cannot open or read %s", read_from); + break; + case S_IFLNK: + if (readlink(read_from, buf.buf, buf.alloc) != fin_size) + die("cannot readlink %s", read_from); + buf.len = fin_size; + break; + default: + die("unsupported file type %s", read_from); + } + } + else { + /* Reading from stdin */ + contents_from = "standard input"; + mode = 0; + if (strbuf_read(&buf, 0, 0) < 0) + die("read error %s from stdin", strerror(errno)); + } + 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_sha1); + commit->util = origin; + + /* + * 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); + hashcpy(ce->sha1, origin->blob_sha1); + memcpy(ce->name, path, len); + ce->ce_flags = create_ce_flags(len, 0); + ce->ce_mode = create_ce_mode(mode); + add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); + + /* + * We are not going to write this out, so this does not matter + * right now, but someday we might optimize diff-index --cached + * with cache-tree information. + */ + cache_tree_invalidate_path(active_cache_tree, path); + + commit->buffer = xmalloc(400); + ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0); + snprintf(commit->buffer, 400, + "tree 0000000000000000000000000000000000000000\n" + "parent %s\n" + "author %s\n" + "committer %s\n\n" + "Version of %s from %s\n", + sha1_to_hex(head_sha1), + ident, ident, path, contents_from ? contents_from : path); + return commit; +} + +static const char *prepare_final(struct scoreboard *sb) +{ + int i; + const char *final_commit_name = NULL; + struct rev_info *revs = sb->revs; + + /* + * There must be one and only one positive commit in the + * revs->pending array. + */ + for (i = 0; i < revs->pending.nr; i++) { + struct object *obj = revs->pending.objects[i].item; + if (obj->flags & UNINTERESTING) + continue; + while (obj->type == OBJ_TAG) + obj = deref_tag(obj, NULL, 0); + if (obj->type != OBJ_COMMIT) + die("Non commit %s?", revs->pending.objects[i].name); + if (sb->final) + die("More than one commit to dig from %s and %s?", + revs->pending.objects[i].name, + final_commit_name); + sb->final = (struct commit *) obj; + final_commit_name = revs->pending.objects[i].name; + } + return final_commit_name; +} + +static const char *prepare_initial(struct scoreboard *sb) +{ + int i; + const char *final_commit_name = NULL; + struct rev_info *revs = sb->revs; + + /* + * 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; + while (obj->type == OBJ_TAG) + obj = deref_tag(obj, NULL, 0); + if (obj->type != OBJ_COMMIT) + die("Non commit %s?", revs->pending.objects[i].name); + if (sb->final) + die("More than one commit to dig down to %s and %s?", + revs->pending.objects[i].name, + final_commit_name); + sb->final = (struct commit *) obj; + final_commit_name = revs->pending.objects[i].name; + } + if (!final_commit_name) + die("No commit to dig down to?"); + return final_commit_name; +} + +static int blame_copy_callback(const struct option *option, const char *arg, int unset) +{ + int *opt = option->value; + + /* + * -C enables copy from removed files; + * -C -C enables copy from existing files, but only + * when blaming a new file; + * -C -C -C enables copy from existing files for + * everybody + */ + if (*opt & PICKAXE_BLAME_COPY_HARDER) + *opt |= PICKAXE_BLAME_COPY_HARDEST; + if (*opt & PICKAXE_BLAME_COPY) + *opt |= PICKAXE_BLAME_COPY_HARDER; + *opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE; + + if (arg) + blame_copy_score = parse_score(arg); + return 0; +} + +static int blame_move_callback(const struct option *option, const char *arg, int unset) +{ + int *opt = option->value; + + *opt |= PICKAXE_BLAME_MOVE; + + if (arg) + blame_move_score = parse_score(arg); + return 0; +} + +static int blame_bottomtop_callback(const struct option *option, const char *arg, int unset) +{ + const char **bottomtop = option->value; + if (!arg) + return -1; + if (*bottomtop) + die("More than one '-L n,m' option given"); + *bottomtop = arg; + return 0; +} + +int cmd_blame(int argc, const char **argv, const char *prefix) +{ + struct rev_info revs; + const char *path; + struct scoreboard sb; + struct origin *o; + struct blame_entry *ent; + long dashdash_pos, bottom, top, lno; + const char *final_commit_name = NULL; + enum object_type type; + + static const char *bottomtop = NULL; + static int output_option = 0, opt = 0; + static int show_stats = 0; + static const char *revs_file = NULL; + static const char *contents_from = NULL; + static const struct option options[] = { + OPT_BOOLEAN(0, "incremental", &incremental, "Show blame entries as we find them, incrementally"), + OPT_BOOLEAN('b', NULL, &blank_boundary, "Show blank SHA-1 for boundary commits (Default: off)"), + OPT_BOOLEAN(0, "root", &show_root, "Do not treat root commits as boundaries (Default: off)"), + OPT_BOOLEAN(0, "show-stats", &show_stats, "Show work cost statistics"), + OPT_BIT(0, "score-debug", &output_option, "Show output score for blame entries", OUTPUT_SHOW_SCORE), + OPT_BIT('f', "show-name", &output_option, "Show original filename (Default: auto)", OUTPUT_SHOW_NAME), + OPT_BIT('n', "show-number", &output_option, "Show original linenumber (Default: off)", OUTPUT_SHOW_NUMBER), + OPT_BIT('p', "porcelain", &output_option, "Show in a format designed for machine consumption", OUTPUT_PORCELAIN), + OPT_BIT('c', NULL, &output_option, "Use the same output mode as git-annotate (Default: off)", OUTPUT_ANNOTATE_COMPAT), + OPT_BIT('t', NULL, &output_option, "Show raw timestamp (Default: off)", OUTPUT_RAW_TIMESTAMP), + OPT_BIT('l', NULL, &output_option, "Show long commit SHA1 (Default: off)", OUTPUT_LONG_OBJECT_NAME), + OPT_BIT('s', NULL, &output_option, "Suppress author name and timestamp (Default: off)", OUTPUT_NO_AUTHOR), + OPT_BIT('w', NULL, &xdl_opts, "Ignore whitespace differences", XDF_IGNORE_WHITESPACE), + OPT_STRING('S', NULL, &revs_file, "file", "Use revisions from <file> instead of calling git-rev-list"), + OPT_STRING(0, "contents", &contents_from, "file", "Use <file>'s contents as the final image"), + { OPTION_CALLBACK, 'C', NULL, &opt, "score", "Find line copies within and across files", PARSE_OPT_OPTARG, blame_copy_callback }, + { OPTION_CALLBACK, 'M', NULL, &opt, "score", "Find line movements within and across files", PARSE_OPT_OPTARG, blame_move_callback }, + OPT_CALLBACK('L', NULL, &bottomtop, "n,m", "Process only line range n,m, counting from 1", blame_bottomtop_callback), + OPT_END() + }; + + struct parse_opt_ctx_t ctx; + + cmd_is_annotate = !strcmp(argv[0], "annotate"); + + git_config(git_blame_config, NULL); + init_revisions(&revs, NULL); + save_commit_buffer = 0; + dashdash_pos = 0; + + parse_options_start(&ctx, argc, argv, PARSE_OPT_KEEP_DASHDASH | + PARSE_OPT_KEEP_ARGV0); + for (;;) { + switch (parse_options_step(&ctx, options, blame_opt_usage)) { + case PARSE_OPT_HELP: + exit(129); + case PARSE_OPT_DONE: + if (ctx.argv[0]) + dashdash_pos = ctx.cpidx; + goto parse_done; + } + + if (!strcmp(ctx.argv[0], "--reverse")) { + ctx.argv[0] = "--children"; + reverse = 1; + } + parse_revision_opt(&revs, &ctx, options, blame_opt_usage); + } +parse_done: + argc = parse_options_end(&ctx); + + if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER)) + opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE | + PICKAXE_BLAME_COPY_HARDER); + + if (!blame_move_score) + blame_move_score = BLAME_DEFAULT_MOVE_SCORE; + if (!blame_copy_score) + blame_copy_score = BLAME_DEFAULT_COPY_SCORE; + + /* + * We have collected options unknown to us in argv[1..unk] + * which are to be passed to revision machinery if we are + * going to do the "bottom" processing. + * + * The remaining are: + * + * (1) if dashdash_pos != 0, its either + * "blame [revisions] -- <path>" or + * "blame -- <path> <rev>" + * + * (2) otherwise, its one of the two: + * "blame [revisions] <path>" + * "blame <path> <rev>" + * + * Note that we must strip out <path> from the arguments: we do not + * want the path pruning but we may want "bottom" processing. + */ + if (dashdash_pos) { + switch (argc - dashdash_pos - 1) { + case 2: /* (1b) */ + if (argc != 4) + usage_with_options(blame_opt_usage, options); + /* reorder for the new way: <rev> -- <path> */ + argv[1] = argv[3]; + argv[3] = argv[2]; + argv[2] = "--"; + /* FALLTHROUGH */ + case 1: /* (1a) */ + path = add_prefix(prefix, argv[--argc]); + argv[argc] = NULL; + break; + default: + usage_with_options(blame_opt_usage, options); + } + } else { + if (argc < 2) + usage_with_options(blame_opt_usage, options); + path = add_prefix(prefix, argv[argc - 1]); + if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */ + path = add_prefix(prefix, argv[1]); + argv[1] = argv[2]; + } + argv[argc - 1] = "--"; + + setup_work_tree(); + if (!has_string_in_work_tree(path)) + die("cannot stat path %s: %s", path, strerror(errno)); + } + + setup_revisions(argc, argv, &revs, NULL); + memset(&sb, 0, sizeof(sb)); + + sb.revs = &revs; + if (!reverse) + final_commit_name = prepare_final(&sb); + else if (contents_from) + die("--contents and --children do not blend well."); + else + final_commit_name = prepare_initial(&sb); + + 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(path, contents_from); + add_pending_object(&revs, &(sb.final->object), ":"); + } + else if (contents_from) + die("Cannot use --contents with final commit object name"); + + /* + * If we have bottom, this will mark the ancestors of the + * bottom commits we would reach while traversing as + * uninteresting. + */ + if (prepare_revision_walk(&revs)) + die("revision walk setup failed"); + + if (is_null_sha1(sb.final->object.sha1)) { + char *buf; + o = sb.final->util; + buf = xmalloc(o->file.size + 1); + memcpy(buf, o->file.ptr, o->file.size + 1); + sb.final_buf = buf; + sb.final_buf_size = o->file.size; + } + else { + o = get_origin(&sb, sb.final, path); + if (fill_blob_sha1(o)) + die("no such path %s in %s", path, final_commit_name); + + sb.final_buf = read_sha1_file(o->blob_sha1, &type, + &sb.final_buf_size); + if (!sb.final_buf) + die("Cannot read blob %s for path %s", + sha1_to_hex(o->blob_sha1), + path); + } + num_read_blob++; + lno = prepare_lines(&sb); + + bottom = top = 0; + if (bottomtop) + prepare_blame_range(&sb, bottomtop, lno, &bottom, &top); + if (bottom && top && top < bottom) { + long tmp; + tmp = top; top = bottom; bottom = tmp; + } + if (bottom < 1) + bottom = 1; + if (top < 1) + top = lno; + bottom--; + if (lno < top) + die("file %s has only %lu lines", path, lno); + + ent = xcalloc(1, sizeof(*ent)); + ent->lno = bottom; + ent->num_lines = top - bottom; + ent->suspect = o; + ent->s_lno = bottom; + + sb.ent = ent; + sb.path = path; + + if (revs_file && read_ancestry(revs_file)) + die("reading graft file %s failed: %s", + revs_file, strerror(errno)); + + read_mailmap(&mailmap, ".mailmap", NULL); + + if (!incremental) + setup_pager(); + + assign_blame(&sb, opt); + + if (incremental) + return 0; + + coalesce(&sb); + + if (!(output_option & OUTPUT_PORCELAIN)) + find_alignment(&sb, &output_option); + + output(&sb, output_option); + free((void *)sb.final_buf); + for (ent = sb.ent; ent; ) { + struct blame_entry *e = ent->next; + free(ent); + ent = e; + } + + if (show_stats) { + printf("num read blob: %d\n", num_read_blob); + printf("num get patch: %d\n", num_get_patch); + printf("num commits: %d\n", num_commits); + } + return 0; +} |