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git/builtin-log.c
Linus Torvalds 750f7b668f Finally implement "git log --follow"
Ok, I've really held off doing this too damn long, because I'm lazy, and I
was always hoping that somebody else would do it.

But no, people keep asking for it, but nobody actually did anything, so I
decided I might as well bite the bullet, and instead of telling people
they could add a "--follow" flag to "git log" to do what they want to do,
I decided that it looks like I just have to do it for them..

The code wasn't actually that complicated, in that the diffstat for this
patch literally says "70 insertions(+), 1 deletions(-)", but I will have
to admit that in order to get to this fairly simple patch, you did have to
know and understand the internal git diff generation machinery pretty
well, and had to really be able to follow how commit generation interacts
with generating patches and generating the log.

So I suspect that while I was right that it wasn't that hard, I might have
been expecting too much of random people - this patch does seem to be
firmly in the core "Linus or Junio" territory.

To make a long story short: I'm sorry for it taking so long until I just
did it.

I'm not going to guarantee that this works for everybody, but you really
can just look at the patch, and after the appropriate appreciative noises
("Ooh, aah") over how clever I am, you can then just notice that the code
itself isn't really that complicated.

All the real new code is in the new "try_to_follow_renames()" function. It
really isn't rocket science: we notice that the pathname we were looking
at went away, so we start a full tree diff and try to see if we can
instead make that pathname be a rename or a copy from some other previous
pathname. And if we can, we just continue, except we show *that*
particular diff, and ever after we use the _previous_ pathname.

One thing to look out for: the "rename detection" is considered to be a
singular event in the _linear_ "git log" output! That's what people want
to do, but I just wanted to point out that this patch is *not* carrying
around a "commit,pathname" kind of pair and it's *not* going to be able to
notice the file coming from multiple *different* files in earlier history.

IOW, if you use "git log --follow", then you get the stupid CVS/SVN kind
of "files have single identities" kind of semantics, and git log will just
pick the identity based on the normal move/copy heuristics _as_if_ the
history could be linearized.

Put another way: I think the model is broken, but given the broken model,
I think this patch does just about as well as you can do. If you have
merges with the same "file" having different filenames over the two
branches, git will just end up picking _one_ of the pathnames at the point
where the newer one goes away. It never looks at multiple pathnames in
parallel.

And if you understood all that, you probably didn't need it explained, and
if you didn't understand the above blathering, it doesn't really mtter to
you. What matters to you is that you can now do

	git log -p --follow builtin-rev-list.c

and it will find the point where the old "rev-list.c" got renamed to
"builtin-rev-list.c" and show it as such.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-22 23:37:11 -07:00

769 lines
19 KiB
C

/*
* Builtin "git log" and related commands (show, whatchanged)
*
* (C) Copyright 2006 Linus Torvalds
* 2006 Junio Hamano
*/
#include "cache.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "log-tree.h"
#include "builtin.h"
#include "tag.h"
#include "reflog-walk.h"
#include "patch-ids.h"
#include "refs.h"
static int default_show_root = 1;
/* this is in builtin-diff.c */
void add_head(struct rev_info *revs);
static void add_name_decoration(const char *prefix, const char *name, struct object *obj)
{
int plen = strlen(prefix);
int nlen = strlen(name);
struct name_decoration *res = xmalloc(sizeof(struct name_decoration) + plen + nlen);
memcpy(res->name, prefix, plen);
memcpy(res->name + plen, name, nlen + 1);
res->next = add_decoration(&name_decoration, obj, res);
}
static int add_ref_decoration(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
{
struct object *obj = parse_object(sha1);
if (!obj)
return 0;
add_name_decoration("", refname, obj);
while (obj->type == OBJ_TAG) {
obj = ((struct tag *)obj)->tagged;
if (!obj)
break;
add_name_decoration("tag: ", refname, obj);
}
return 0;
}
static void cmd_log_init(int argc, const char **argv, const char *prefix,
struct rev_info *rev)
{
int i;
int decorate = 0;
rev->abbrev = DEFAULT_ABBREV;
rev->commit_format = CMIT_FMT_DEFAULT;
rev->verbose_header = 1;
rev->show_root_diff = default_show_root;
argc = setup_revisions(argc, argv, rev, "HEAD");
if (rev->diffopt.pickaxe || rev->diffopt.filter)
rev->always_show_header = 0;
if (rev->diffopt.follow_renames) {
rev->always_show_header = 0;
if (rev->diffopt.nr_paths != 1)
usage("git logs can only follow renames on one pathname at a time");
}
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--decorate")) {
if (!decorate)
for_each_ref(add_ref_decoration, NULL);
decorate = 1;
} else
die("unrecognized argument: %s", arg);
}
}
static int cmd_log_walk(struct rev_info *rev)
{
struct commit *commit;
prepare_revision_walk(rev);
while ((commit = get_revision(rev)) != NULL) {
log_tree_commit(rev, commit);
if (!rev->reflog_info) {
/* we allow cycles in reflog ancestry */
free(commit->buffer);
commit->buffer = NULL;
}
free_commit_list(commit->parents);
commit->parents = NULL;
}
return 0;
}
static int git_log_config(const char *var, const char *value)
{
if (!strcmp(var, "log.showroot")) {
default_show_root = git_config_bool(var, value);
return 0;
}
return git_diff_ui_config(var, value);
}
int cmd_whatchanged(int argc, const char **argv, const char *prefix)
{
struct rev_info rev;
git_config(git_log_config);
init_revisions(&rev, prefix);
rev.diff = 1;
rev.diffopt.recursive = 1;
rev.simplify_history = 0;
cmd_log_init(argc, argv, prefix, &rev);
if (!rev.diffopt.output_format)
rev.diffopt.output_format = DIFF_FORMAT_RAW;
return cmd_log_walk(&rev);
}
static int show_object(const unsigned char *sha1, int suppress_header)
{
unsigned long size;
enum object_type type;
char *buf = read_sha1_file(sha1, &type, &size);
int offset = 0;
if (!buf)
return error("Could not read object %s", sha1_to_hex(sha1));
if (suppress_header)
while (offset < size && buf[offset++] != '\n') {
int new_offset = offset;
while (new_offset < size && buf[new_offset++] != '\n')
; /* do nothing */
offset = new_offset;
}
if (offset < size)
fwrite(buf + offset, size - offset, 1, stdout);
free(buf);
return 0;
}
static int show_tree_object(const unsigned char *sha1,
const char *base, int baselen,
const char *pathname, unsigned mode, int stage)
{
printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
return 0;
}
int cmd_show(int argc, const char **argv, const char *prefix)
{
struct rev_info rev;
struct object_array_entry *objects;
int i, count, ret = 0;
git_config(git_log_config);
init_revisions(&rev, prefix);
rev.diff = 1;
rev.diffopt.recursive = 1;
rev.combine_merges = 1;
rev.dense_combined_merges = 1;
rev.always_show_header = 1;
rev.ignore_merges = 0;
rev.no_walk = 1;
cmd_log_init(argc, argv, prefix, &rev);
count = rev.pending.nr;
objects = rev.pending.objects;
for (i = 0; i < count && !ret; i++) {
struct object *o = objects[i].item;
const char *name = objects[i].name;
switch (o->type) {
case OBJ_BLOB:
ret = show_object(o->sha1, 0);
break;
case OBJ_TAG: {
struct tag *t = (struct tag *)o;
printf("%stag %s%s\n\n",
diff_get_color(rev.diffopt.color_diff,
DIFF_COMMIT),
t->tag,
diff_get_color(rev.diffopt.color_diff,
DIFF_RESET));
ret = show_object(o->sha1, 1);
objects[i].item = (struct object *)t->tagged;
i--;
break;
}
case OBJ_TREE:
printf("%stree %s%s\n\n",
diff_get_color(rev.diffopt.color_diff,
DIFF_COMMIT),
name,
diff_get_color(rev.diffopt.color_diff,
DIFF_RESET));
read_tree_recursive((struct tree *)o, "", 0, 0, NULL,
show_tree_object);
break;
case OBJ_COMMIT:
rev.pending.nr = rev.pending.alloc = 0;
rev.pending.objects = NULL;
add_object_array(o, name, &rev.pending);
ret = cmd_log_walk(&rev);
break;
default:
ret = error("Unknown type: %d", o->type);
}
}
free(objects);
return ret;
}
/*
* This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
*/
int cmd_log_reflog(int argc, const char **argv, const char *prefix)
{
struct rev_info rev;
git_config(git_log_config);
init_revisions(&rev, prefix);
init_reflog_walk(&rev.reflog_info);
rev.abbrev_commit = 1;
rev.verbose_header = 1;
cmd_log_init(argc, argv, prefix, &rev);
/*
* This means that we override whatever commit format the user gave
* on the cmd line. Sad, but cmd_log_init() currently doesn't
* allow us to set a different default.
*/
rev.commit_format = CMIT_FMT_ONELINE;
rev.always_show_header = 1;
/*
* We get called through "git reflog", so unlike the other log
* routines, we need to set up our pager manually..
*/
setup_pager();
return cmd_log_walk(&rev);
}
int cmd_log(int argc, const char **argv, const char *prefix)
{
struct rev_info rev;
git_config(git_log_config);
init_revisions(&rev, prefix);
rev.always_show_header = 1;
cmd_log_init(argc, argv, prefix, &rev);
return cmd_log_walk(&rev);
}
/* format-patch */
#define FORMAT_PATCH_NAME_MAX 64
static int istitlechar(char c)
{
return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') || c == '.' || c == '_';
}
static char *extra_headers = NULL;
static int extra_headers_size = 0;
static const char *fmt_patch_suffix = ".patch";
static int git_format_config(const char *var, const char *value)
{
if (!strcmp(var, "format.headers")) {
int len;
if (!value)
die("format.headers without value");
len = strlen(value);
extra_headers_size += len + 1;
extra_headers = xrealloc(extra_headers, extra_headers_size);
extra_headers[extra_headers_size - len - 1] = 0;
strcat(extra_headers, value);
return 0;
}
if (!strcmp(var, "format.suffix")) {
if (!value)
die("format.suffix without value");
fmt_patch_suffix = xstrdup(value);
return 0;
}
if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
return 0;
}
return git_log_config(var, value);
}
static FILE *realstdout = NULL;
static const char *output_directory = NULL;
static int reopen_stdout(struct commit *commit, int nr, int keep_subject,
int numbered_files)
{
char filename[PATH_MAX];
char *sol;
int len = 0;
int suffix_len = strlen(fmt_patch_suffix) + 1;
if (output_directory) {
if (strlen(output_directory) >=
sizeof(filename) - FORMAT_PATCH_NAME_MAX - suffix_len)
return error("name of output directory is too long");
strlcpy(filename, output_directory, sizeof(filename) - suffix_len);
len = strlen(filename);
if (filename[len - 1] != '/')
filename[len++] = '/';
}
if (numbered_files) {
sprintf(filename + len, "%d", nr);
len = strlen(filename);
} else {
sprintf(filename + len, "%04d", nr);
len = strlen(filename);
sol = strstr(commit->buffer, "\n\n");
if (sol) {
int j, space = 1;
sol += 2;
/* strip [PATCH] or [PATCH blabla] */
if (!keep_subject && !prefixcmp(sol, "[PATCH")) {
char *eos = strchr(sol + 6, ']');
if (eos) {
while (isspace(*eos))
eos++;
sol = eos;
}
}
for (j = 0;
j < FORMAT_PATCH_NAME_MAX - suffix_len - 5 &&
len < sizeof(filename) - suffix_len &&
sol[j] && sol[j] != '\n';
j++) {
if (istitlechar(sol[j])) {
if (space) {
filename[len++] = '-';
space = 0;
}
filename[len++] = sol[j];
if (sol[j] == '.')
while (sol[j + 1] == '.')
j++;
} else
space = 1;
}
while (filename[len - 1] == '.'
|| filename[len - 1] == '-')
len--;
filename[len] = 0;
}
if (len + suffix_len >= sizeof(filename))
return error("Patch pathname too long");
strcpy(filename + len, fmt_patch_suffix);
}
fprintf(realstdout, "%s\n", filename);
if (freopen(filename, "w", stdout) == NULL)
return error("Cannot open patch file %s",filename);
return 0;
}
static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
{
struct rev_info check_rev;
struct commit *commit;
struct object *o1, *o2;
unsigned flags1, flags2;
if (rev->pending.nr != 2)
die("Need exactly one range.");
o1 = rev->pending.objects[0].item;
flags1 = o1->flags;
o2 = rev->pending.objects[1].item;
flags2 = o2->flags;
if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
die("Not a range.");
init_patch_ids(ids);
/* given a range a..b get all patch ids for b..a */
init_revisions(&check_rev, prefix);
o1->flags ^= UNINTERESTING;
o2->flags ^= UNINTERESTING;
add_pending_object(&check_rev, o1, "o1");
add_pending_object(&check_rev, o2, "o2");
prepare_revision_walk(&check_rev);
while ((commit = get_revision(&check_rev)) != NULL) {
/* ignore merges */
if (commit->parents && commit->parents->next)
continue;
add_commit_patch_id(commit, ids);
}
/* reset for next revision walk */
clear_commit_marks((struct commit *)o1,
SEEN | UNINTERESTING | SHOWN | ADDED);
clear_commit_marks((struct commit *)o2,
SEEN | UNINTERESTING | SHOWN | ADDED);
o1->flags = flags1;
o2->flags = flags2;
}
static void gen_message_id(char *dest, unsigned int length, char *base)
{
const char *committer = git_committer_info(-1);
const char *email_start = strrchr(committer, '<');
const char *email_end = strrchr(committer, '>');
if(!email_start || !email_end || email_start > email_end - 1)
die("Could not extract email from committer identity.");
snprintf(dest, length, "%s.%lu.git.%.*s", base,
(unsigned long) time(NULL),
(int)(email_end - email_start - 1), email_start + 1);
}
int cmd_format_patch(int argc, const char **argv, const char *prefix)
{
struct commit *commit;
struct commit **list = NULL;
struct rev_info rev;
int nr = 0, total, i, j;
int use_stdout = 0;
int numbered = 0;
int start_number = -1;
int keep_subject = 0;
int numbered_files = 0; /* _just_ numbers */
int subject_prefix = 0;
int ignore_if_in_upstream = 0;
int thread = 0;
const char *in_reply_to = NULL;
struct patch_ids ids;
char *add_signoff = NULL;
char message_id[1024];
char ref_message_id[1024];
git_config(git_format_config);
init_revisions(&rev, prefix);
rev.commit_format = CMIT_FMT_EMAIL;
rev.verbose_header = 1;
rev.diff = 1;
rev.combine_merges = 0;
rev.ignore_merges = 1;
rev.diffopt.msg_sep = "";
rev.diffopt.recursive = 1;
rev.extra_headers = extra_headers;
/*
* Parse the arguments before setup_revisions(), or something
* like "git format-patch -o a123 HEAD^.." may fail; a123 is
* possibly a valid SHA1.
*/
for (i = 1, j = 1; i < argc; i++) {
if (!strcmp(argv[i], "--stdout"))
use_stdout = 1;
else if (!strcmp(argv[i], "-n") ||
!strcmp(argv[i], "--numbered"))
numbered = 1;
else if (!prefixcmp(argv[i], "--start-number="))
start_number = strtol(argv[i] + 15, NULL, 10);
else if (!strcmp(argv[i], "--numbered-files"))
numbered_files = 1;
else if (!strcmp(argv[i], "--start-number")) {
i++;
if (i == argc)
die("Need a number for --start-number");
start_number = strtol(argv[i], NULL, 10);
}
else if (!strcmp(argv[i], "-k") ||
!strcmp(argv[i], "--keep-subject")) {
keep_subject = 1;
rev.total = -1;
}
else if (!strcmp(argv[i], "--output-directory") ||
!strcmp(argv[i], "-o")) {
i++;
if (argc <= i)
die("Which directory?");
if (output_directory)
die("Two output directories?");
output_directory = argv[i];
}
else if (!strcmp(argv[i], "--signoff") ||
!strcmp(argv[i], "-s")) {
const char *committer;
const char *endpos;
committer = git_committer_info(1);
endpos = strchr(committer, '>');
if (!endpos)
die("bogos committer info %s\n", committer);
add_signoff = xmalloc(endpos - committer + 2);
memcpy(add_signoff, committer, endpos - committer + 1);
add_signoff[endpos - committer + 1] = 0;
}
else if (!strcmp(argv[i], "--attach")) {
rev.mime_boundary = git_version_string;
rev.no_inline = 1;
}
else if (!prefixcmp(argv[i], "--attach=")) {
rev.mime_boundary = argv[i] + 9;
rev.no_inline = 1;
}
else if (!strcmp(argv[i], "--inline")) {
rev.mime_boundary = git_version_string;
rev.no_inline = 0;
}
else if (!prefixcmp(argv[i], "--inline=")) {
rev.mime_boundary = argv[i] + 9;
rev.no_inline = 0;
}
else if (!strcmp(argv[i], "--ignore-if-in-upstream"))
ignore_if_in_upstream = 1;
else if (!strcmp(argv[i], "--thread"))
thread = 1;
else if (!prefixcmp(argv[i], "--in-reply-to="))
in_reply_to = argv[i] + 14;
else if (!strcmp(argv[i], "--in-reply-to")) {
i++;
if (i == argc)
die("Need a Message-Id for --in-reply-to");
in_reply_to = argv[i];
} else if (!prefixcmp(argv[i], "--subject-prefix=")) {
subject_prefix = 1;
rev.subject_prefix = argv[i] + 17;
} else if (!prefixcmp(argv[i], "--suffix="))
fmt_patch_suffix = argv[i] + 9;
else
argv[j++] = argv[i];
}
argc = j;
if (start_number < 0)
start_number = 1;
if (numbered && keep_subject)
die ("-n and -k are mutually exclusive.");
if (keep_subject && subject_prefix)
die ("--subject-prefix and -k are mutually exclusive.");
if (numbered_files && use_stdout)
die ("--numbered-files and --stdout are mutually exclusive.");
argc = setup_revisions(argc, argv, &rev, "HEAD");
if (argc > 1)
die ("unrecognized argument: %s", argv[1]);
if (!rev.diffopt.output_format)
rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY | DIFF_FORMAT_PATCH;
if (!rev.diffopt.text)
rev.diffopt.binary = 1;
if (!output_directory && !use_stdout)
output_directory = prefix;
if (output_directory) {
if (use_stdout)
die("standard output, or directory, which one?");
if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
die("Could not create directory %s",
output_directory);
}
if (rev.pending.nr == 1) {
if (rev.max_count < 0) {
rev.pending.objects[0].item->flags |= UNINTERESTING;
add_head(&rev);
}
/* Otherwise, it is "format-patch -22 HEAD", and
* get_revision() would return only the specified count.
*/
}
if (ignore_if_in_upstream)
get_patch_ids(&rev, &ids, prefix);
if (!use_stdout)
realstdout = fdopen(dup(1), "w");
prepare_revision_walk(&rev);
while ((commit = get_revision(&rev)) != NULL) {
/* ignore merges */
if (commit->parents && commit->parents->next)
continue;
if (ignore_if_in_upstream &&
has_commit_patch_id(commit, &ids))
continue;
nr++;
list = xrealloc(list, nr * sizeof(list[0]));
list[nr - 1] = commit;
}
total = nr;
if (numbered)
rev.total = total + start_number - 1;
rev.add_signoff = add_signoff;
rev.ref_message_id = in_reply_to;
while (0 <= --nr) {
int shown;
commit = list[nr];
rev.nr = total - nr + (start_number - 1);
/* Make the second and subsequent mails replies to the first */
if (thread) {
if (nr == (total - 2)) {
strncpy(ref_message_id, message_id,
sizeof(ref_message_id));
ref_message_id[sizeof(ref_message_id)-1]='\0';
rev.ref_message_id = ref_message_id;
}
gen_message_id(message_id, sizeof(message_id),
sha1_to_hex(commit->object.sha1));
rev.message_id = message_id;
}
if (!use_stdout)
if (reopen_stdout(commit, rev.nr, keep_subject,
numbered_files))
die("Failed to create output files");
shown = log_tree_commit(&rev, commit);
free(commit->buffer);
commit->buffer = NULL;
/* We put one extra blank line between formatted
* patches and this flag is used by log-tree code
* to see if it needs to emit a LF before showing
* the log; when using one file per patch, we do
* not want the extra blank line.
*/
if (!use_stdout)
rev.shown_one = 0;
if (shown) {
if (rev.mime_boundary)
printf("\n--%s%s--\n\n\n",
mime_boundary_leader,
rev.mime_boundary);
else
printf("-- \n%s\n\n", git_version_string);
}
if (!use_stdout)
fclose(stdout);
}
free(list);
if (ignore_if_in_upstream)
free_patch_ids(&ids);
return 0;
}
static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
{
unsigned char sha1[20];
if (get_sha1(arg, sha1) == 0) {
struct commit *commit = lookup_commit_reference(sha1);
if (commit) {
commit->object.flags |= flags;
add_pending_object(revs, &commit->object, arg);
return 0;
}
}
return -1;
}
static const char cherry_usage[] =
"git-cherry [-v] <upstream> [<head>] [<limit>]";
int cmd_cherry(int argc, const char **argv, const char *prefix)
{
struct rev_info revs;
struct patch_ids ids;
struct commit *commit;
struct commit_list *list = NULL;
const char *upstream;
const char *head = "HEAD";
const char *limit = NULL;
int verbose = 0;
if (argc > 1 && !strcmp(argv[1], "-v")) {
verbose = 1;
argc--;
argv++;
}
switch (argc) {
case 4:
limit = argv[3];
/* FALLTHROUGH */
case 3:
head = argv[2];
/* FALLTHROUGH */
case 2:
upstream = argv[1];
break;
default:
usage(cherry_usage);
}
init_revisions(&revs, prefix);
revs.diff = 1;
revs.combine_merges = 0;
revs.ignore_merges = 1;
revs.diffopt.recursive = 1;
if (add_pending_commit(head, &revs, 0))
die("Unknown commit %s", head);
if (add_pending_commit(upstream, &revs, UNINTERESTING))
die("Unknown commit %s", upstream);
/* Don't say anything if head and upstream are the same. */
if (revs.pending.nr == 2) {
struct object_array_entry *o = revs.pending.objects;
if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
return 0;
}
get_patch_ids(&revs, &ids, prefix);
if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
die("Unknown commit %s", limit);
/* reverse the list of commits */
prepare_revision_walk(&revs);
while ((commit = get_revision(&revs)) != NULL) {
/* ignore merges */
if (commit->parents && commit->parents->next)
continue;
commit_list_insert(commit, &list);
}
while (list) {
char sign = '+';
commit = list->item;
if (has_commit_patch_id(commit, &ids))
sign = '-';
if (verbose) {
char *buf = NULL;
unsigned long buflen = 0;
pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
&buf, &buflen, 0, NULL, NULL, 0);
printf("%c %s %s\n", sign,
sha1_to_hex(commit->object.sha1), buf);
free(buf);
}
else {
printf("%c %s\n", sign,
sha1_to_hex(commit->object.sha1));
}
list = list->next;
}
free_patch_ids(&ids);
return 0;
}