git/diff-lib.c
Junio C Hamano 1cfe77333f git-blame: no rev means start from the working tree file.
Warning: this changes the semantics.

This makes "git blame" without any positive rev to start digging
from the working tree copy, which is made into a fake commit
whose sole parent is the HEAD.

It also adds --contents <file> option to pretend as if the
working tree copy has the contents of the named file.  You can
use '-' to make the command read from the standard input.

If you want the command to start annotating from the HEAD
commit, you need to explicitly give HEAD parameter.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-05 14:55:11 -08:00

417 lines
9.9 KiB
C

/*
* Copyright (C) 2005 Junio C Hamano
*/
#include "cache.h"
#include "quote.h"
#include "commit.h"
#include "diff.h"
#include "diffcore.h"
#include "revision.h"
#include "cache-tree.h"
/*
* diff-files
*/
int run_diff_files(struct rev_info *revs, int silent_on_removed)
{
int entries, i;
int diff_unmerged_stage = revs->max_count;
if (diff_unmerged_stage < 0)
diff_unmerged_stage = 2;
entries = read_cache();
if (entries < 0) {
perror("read_cache");
return -1;
}
for (i = 0; i < entries; i++) {
struct stat st;
unsigned int oldmode, newmode;
struct cache_entry *ce = active_cache[i];
int changed;
if (!ce_path_match(ce, revs->prune_data))
continue;
if (ce_stage(ce)) {
struct combine_diff_path *dpath;
int num_compare_stages = 0;
size_t path_len;
path_len = ce_namelen(ce);
dpath = xmalloc (combine_diff_path_size (5, path_len));
dpath->path = (char *) &(dpath->parent[5]);
dpath->next = NULL;
dpath->len = path_len;
memcpy(dpath->path, ce->name, path_len);
dpath->path[path_len] = '\0';
dpath->mode = 0;
hashclr(dpath->sha1);
memset(&(dpath->parent[0]), 0,
sizeof(struct combine_diff_parent)*5);
while (i < entries) {
struct cache_entry *nce = active_cache[i];
int stage;
if (strcmp(ce->name, nce->name))
break;
/* Stage #2 (ours) is the first parent,
* stage #3 (theirs) is the second.
*/
stage = ce_stage(nce);
if (2 <= stage) {
int mode = ntohl(nce->ce_mode);
num_compare_stages++;
hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
dpath->parent[stage-2].mode =
canon_mode(mode);
dpath->parent[stage-2].status =
DIFF_STATUS_MODIFIED;
}
/* diff against the proper unmerged stage */
if (stage == diff_unmerged_stage)
ce = nce;
i++;
}
/*
* Compensate for loop update
*/
i--;
if (revs->combine_merges && num_compare_stages == 2) {
show_combined_diff(dpath, 2,
revs->dense_combined_merges,
revs);
free(dpath);
continue;
}
free(dpath);
dpath = NULL;
/*
* Show the diff for the 'ce' if we found the one
* from the desired stage.
*/
diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
if (ce_stage(ce) != diff_unmerged_stage)
continue;
}
if (lstat(ce->name, &st) < 0) {
if (errno != ENOENT && errno != ENOTDIR) {
perror(ce->name);
continue;
}
if (silent_on_removed)
continue;
diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
ce->sha1, ce->name, NULL);
continue;
}
changed = ce_match_stat(ce, &st, 0);
if (!changed && !revs->diffopt.find_copies_harder)
continue;
oldmode = ntohl(ce->ce_mode);
newmode = canon_mode(st.st_mode);
if (!trust_executable_bit &&
S_ISREG(newmode) && S_ISREG(oldmode) &&
((newmode ^ oldmode) == 0111))
newmode = oldmode;
diff_change(&revs->diffopt, oldmode, newmode,
ce->sha1, (changed ? null_sha1 : ce->sha1),
ce->name, NULL);
}
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
return 0;
}
/*
* diff-index
*/
/* A file entry went away or appeared */
static void diff_index_show_file(struct rev_info *revs,
const char *prefix,
struct cache_entry *ce,
unsigned char *sha1, unsigned int mode)
{
diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
sha1, ce->name, NULL);
}
static int get_stat_data(struct cache_entry *ce,
unsigned char **sha1p,
unsigned int *modep,
int cached, int match_missing)
{
unsigned char *sha1 = ce->sha1;
unsigned int mode = ce->ce_mode;
if (!cached) {
static unsigned char no_sha1[20];
int changed;
struct stat st;
if (lstat(ce->name, &st) < 0) {
if (errno == ENOENT && match_missing) {
*sha1p = sha1;
*modep = mode;
return 0;
}
return -1;
}
changed = ce_match_stat(ce, &st, 0);
if (changed) {
mode = create_ce_mode(st.st_mode);
if (!trust_executable_bit && S_ISREG(st.st_mode))
mode = ce->ce_mode;
sha1 = no_sha1;
}
}
*sha1p = sha1;
*modep = mode;
return 0;
}
static void show_new_file(struct rev_info *revs,
struct cache_entry *new,
int cached, int match_missing)
{
unsigned char *sha1;
unsigned int mode;
/* New file in the index: it might actually be different in
* the working copy.
*/
if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
return;
diff_index_show_file(revs, "+", new, sha1, mode);
}
static int show_modified(struct rev_info *revs,
struct cache_entry *old,
struct cache_entry *new,
int report_missing,
int cached, int match_missing)
{
unsigned int mode, oldmode;
unsigned char *sha1;
if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
if (report_missing)
diff_index_show_file(revs, "-", old,
old->sha1, old->ce_mode);
return -1;
}
if (revs->combine_merges && !cached &&
(hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
struct combine_diff_path *p;
int pathlen = ce_namelen(new);
p = xmalloc(combine_diff_path_size(2, pathlen));
p->path = (char *) &p->parent[2];
p->next = NULL;
p->len = pathlen;
memcpy(p->path, new->name, pathlen);
p->path[pathlen] = 0;
p->mode = ntohl(mode);
hashclr(p->sha1);
memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
p->parent[0].status = DIFF_STATUS_MODIFIED;
p->parent[0].mode = ntohl(new->ce_mode);
hashcpy(p->parent[0].sha1, new->sha1);
p->parent[1].status = DIFF_STATUS_MODIFIED;
p->parent[1].mode = ntohl(old->ce_mode);
hashcpy(p->parent[1].sha1, old->sha1);
show_combined_diff(p, 2, revs->dense_combined_merges, revs);
free(p);
return 0;
}
oldmode = old->ce_mode;
if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
!revs->diffopt.find_copies_harder)
return 0;
mode = ntohl(mode);
oldmode = ntohl(oldmode);
diff_change(&revs->diffopt, oldmode, mode,
old->sha1, sha1, old->name, NULL);
return 0;
}
static int diff_cache(struct rev_info *revs,
struct cache_entry **ac, int entries,
const char **pathspec,
int cached, int match_missing)
{
while (entries) {
struct cache_entry *ce = *ac;
int same = (entries > 1) && ce_same_name(ce, ac[1]);
if (!ce_path_match(ce, pathspec))
goto skip_entry;
switch (ce_stage(ce)) {
case 0:
/* No stage 1 entry? That means it's a new file */
if (!same) {
show_new_file(revs, ce, cached, match_missing);
break;
}
/* Show difference between old and new */
show_modified(revs, ac[1], ce, 1,
cached, match_missing);
break;
case 1:
/* No stage 3 (merge) entry?
* That means it's been deleted.
*/
if (!same) {
diff_index_show_file(revs, "-", ce,
ce->sha1, ce->ce_mode);
break;
}
/* We come here with ce pointing at stage 1
* (original tree) and ac[1] pointing at stage
* 3 (unmerged). show-modified with
* report-missing set to false does not say the
* file is deleted but reports true if work
* tree does not have it, in which case we
* fall through to report the unmerged state.
* Otherwise, we show the differences between
* the original tree and the work tree.
*/
if (!cached &&
!show_modified(revs, ce, ac[1], 0,
cached, match_missing))
break;
diff_unmerge(&revs->diffopt, ce->name,
ntohl(ce->ce_mode), ce->sha1);
break;
case 3:
diff_unmerge(&revs->diffopt, ce->name,
0, null_sha1);
break;
default:
die("impossible cache entry stage");
}
skip_entry:
/*
* Ignore all the different stages for this file,
* we've handled the relevant cases now.
*/
do {
ac++;
entries--;
} while (entries && ce_same_name(ce, ac[0]));
}
return 0;
}
/*
* This turns all merge entries into "stage 3". That guarantees that
* when we read in the new tree (into "stage 1"), we won't lose sight
* of the fact that we had unmerged entries.
*/
static void mark_merge_entries(void)
{
int i;
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (!ce_stage(ce))
continue;
ce->ce_flags |= htons(CE_STAGEMASK);
}
}
int run_diff_index(struct rev_info *revs, int cached)
{
int ret;
struct object *ent;
struct tree *tree;
const char *tree_name;
int match_missing = 0;
/*
* Backward compatibility wart - "diff-index -m" does
* not mean "do not ignore merges", but totally different.
*/
if (!revs->ignore_merges)
match_missing = 1;
if (read_cache() < 0) {
perror("read_cache");
return -1;
}
mark_merge_entries();
ent = revs->pending.objects[0].item;
tree_name = revs->pending.objects[0].name;
tree = parse_tree_indirect(ent->sha1);
if (!tree)
return error("bad tree object %s", tree_name);
if (read_tree(tree, 1, revs->prune_data))
return error("unable to read tree object %s", tree_name);
ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
cached, match_missing);
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
return ret;
}
int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
{
struct tree *tree;
struct rev_info revs;
int i;
struct cache_entry **dst;
struct cache_entry *last = NULL;
/*
* This is used by git-blame to run diff-cache internally;
* it potentially needs to repeatedly run this, so we will
* start by removing the higher order entries the last round
* left behind.
*/
dst = active_cache;
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (ce_stage(ce)) {
if (last && !strcmp(ce->name, last->name))
continue;
cache_tree_invalidate_path(active_cache_tree,
ce->name);
last = ce;
ce->ce_mode = 0;
ce->ce_flags &= ~htons(CE_STAGEMASK);
}
*dst++ = ce;
}
active_nr = dst - active_cache;
init_revisions(&revs, NULL);
revs.prune_data = opt->paths;
tree = parse_tree_indirect(tree_sha1);
if (!tree)
die("bad tree object %s", sha1_to_hex(tree_sha1));
if (read_tree(tree, 1, opt->paths))
return error("unable to read tree %s", sha1_to_hex(tree_sha1));
return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
1, 0);
}