git/unpack-trees.c
Junio C Hamano 83c90314aa unpack_trees(): skip trees that are the same in all input
unpack_trees() merges two trees (the current HEAD and the destination
commit) when switching to another branch, checking and updating the index
entry where the destination differs from the current HEAD.  It merges three
trees (the common ancestor, the current HEAD and the other commit) when
performing a three-way merge, checking and updating the index entry when
the merge result differs from the current HEAD.  It does so by walking the
input trees in parallel all the way down to the leaves.

One common special case is a directory is identical across the trees
involved in the merge.  In such a case, we do not have to descend into the
directory at all---we know that the end result is to keep the entries in
the current index.

This optimization cannot be applied in a few special cases in
unpack_trees(), though.  We need to descend into the directory and update
the index entries from the target tree in the following cases:

 - When resetting (e.g. "git reset --hard"); and

 - When checking out a tree for the first time into an empty working tree
   (e.g. "git read-tree -m -u HEAD HEAD" with missing .git/index).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-01-04 13:03:32 -08:00

1654 lines
42 KiB
C

#define NO_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
#include "dir.h"
#include "tree.h"
#include "tree-walk.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#include "progress.h"
#include "refs.h"
#include "attr.h"
/*
* Error messages expected by scripts out of plumbing commands such as
* read-tree. Non-scripted Porcelain is not required to use these messages
* and in fact are encouraged to reword them to better suit their particular
* situation better. See how "git checkout" and "git merge" replaces
* them using setup_unpack_trees_porcelain(), for example.
*/
const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
/* ERROR_WOULD_OVERWRITE */
"Entry '%s' would be overwritten by merge. Cannot merge.",
/* ERROR_NOT_UPTODATE_FILE */
"Entry '%s' not uptodate. Cannot merge.",
/* ERROR_NOT_UPTODATE_DIR */
"Updating '%s' would lose untracked files in it",
/* ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN */
"Untracked working tree file '%s' would be overwritten by merge.",
/* ERROR_WOULD_LOSE_UNTRACKED_REMOVED */
"Untracked working tree file '%s' would be removed by merge.",
/* ERROR_BIND_OVERLAP */
"Entry '%s' overlaps with '%s'. Cannot bind.",
/* ERROR_SPARSE_NOT_UPTODATE_FILE */
"Entry '%s' not uptodate. Cannot update sparse checkout.",
/* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
"Working tree file '%s' would be overwritten by sparse checkout update.",
/* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
"Working tree file '%s' would be removed by sparse checkout update.",
};
#define ERRORMSG(o,type) \
( ((o) && (o)->msgs[(type)]) \
? ((o)->msgs[(type)]) \
: (unpack_plumbing_errors[(type)]) )
void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
const char *cmd)
{
int i;
const char **msgs = opts->msgs;
const char *msg;
char *tmp;
const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
if (advice_commit_before_merge)
msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
"Please, commit your changes or stash them before you can %s.";
else
msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
sprintf(tmp, msg, cmd, cmd2);
msgs[ERROR_WOULD_OVERWRITE] = tmp;
msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
msgs[ERROR_NOT_UPTODATE_DIR] =
"Updating the following directories would lose untracked files in it:\n%s";
if (advice_commit_before_merge)
msg = "The following untracked working tree files would be %s by %s:\n%%s"
"Please move or remove them before you can %s.";
else
msg = "The following untracked working tree files would be %s by %s:\n%%s";
tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
sprintf(tmp, msg, "removed", cmd, cmd2);
msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
sprintf(tmp, msg, "overwritten", cmd, cmd2);
msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
/*
* Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
* cannot easily display it as a list.
*/
msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'. Cannot bind.";
msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
"Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
"The following Working tree files would be overwritten by sparse checkout update:\n%s";
msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
"The following Working tree files would be removed by sparse checkout update:\n%s";
opts->show_all_errors = 1;
/* rejected paths may not have a static buffer */
for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++)
opts->unpack_rejects[i].strdup_strings = 1;
}
static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
unsigned int set, unsigned int clear)
{
unsigned int size = ce_size(ce);
struct cache_entry *new = xmalloc(size);
clear |= CE_HASHED | CE_UNHASHED;
if (set & CE_REMOVE)
set |= CE_WT_REMOVE;
memcpy(new, ce, size);
new->next = NULL;
new->ce_flags = (new->ce_flags & ~clear) | set;
add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
}
/*
* add error messages on path <path>
* corresponding to the type <e> with the message <msg>
* indicating if it should be display in porcelain or not
*/
static int add_rejected_path(struct unpack_trees_options *o,
enum unpack_trees_error_types e,
const char *path)
{
if (!o->show_all_errors)
return error(ERRORMSG(o, e), path);
/*
* Otherwise, insert in a list for future display by
* display_error_msgs()
*/
string_list_append(&o->unpack_rejects[e], path);
return -1;
}
/*
* display all the error messages stored in a nice way
*/
static void display_error_msgs(struct unpack_trees_options *o)
{
int e, i;
int something_displayed = 0;
for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
struct string_list *rejects = &o->unpack_rejects[e];
if (rejects->nr > 0) {
struct strbuf path = STRBUF_INIT;
something_displayed = 1;
for (i = 0; i < rejects->nr; i++)
strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
error(ERRORMSG(o, e), path.buf);
strbuf_release(&path);
}
string_list_clear(rejects, 0);
}
if (something_displayed)
printf("Aborting\n");
}
/*
* Unlink the last component and schedule the leading directories for
* removal, such that empty directories get removed.
*/
static void unlink_entry(struct cache_entry *ce)
{
if (!check_leading_path(ce->name, ce_namelen(ce)))
return;
if (remove_or_warn(ce->ce_mode, ce->name))
return;
schedule_dir_for_removal(ce->name, ce_namelen(ce));
}
static struct checkout state;
static int check_updates(struct unpack_trees_options *o)
{
unsigned cnt = 0, total = 0;
struct progress *progress = NULL;
struct index_state *index = &o->result;
int i;
int errs = 0;
if (o->update && o->verbose_update) {
for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
struct cache_entry *ce = index->cache[cnt];
if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE))
total++;
}
progress = start_progress_delay("Checking out files",
total, 50, 1);
cnt = 0;
}
if (o->update)
git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
for (i = 0; i < index->cache_nr; i++) {
struct cache_entry *ce = index->cache[i];
if (ce->ce_flags & CE_WT_REMOVE) {
display_progress(progress, ++cnt);
if (o->update)
unlink_entry(ce);
continue;
}
}
remove_marked_cache_entries(&o->result);
remove_scheduled_dirs();
for (i = 0; i < index->cache_nr; i++) {
struct cache_entry *ce = index->cache[i];
if (ce->ce_flags & CE_UPDATE) {
display_progress(progress, ++cnt);
ce->ce_flags &= ~CE_UPDATE;
if (o->update) {
errs |= checkout_entry(ce, &state, NULL);
}
}
}
stop_progress(&progress);
if (o->update)
git_attr_set_direction(GIT_ATTR_CHECKIN, NULL);
return errs != 0;
}
static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
static int verify_absent_sparse(struct cache_entry *ce, enum unpack_trees_error_types, struct unpack_trees_options *o);
static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
{
const char *basename;
basename = strrchr(ce->name, '/');
basename = basename ? basename+1 : ce->name;
return excluded_from_list(ce->name, ce_namelen(ce), basename, NULL, o->el) <= 0;
}
static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o)
{
int was_skip_worktree = ce_skip_worktree(ce);
if (!ce_stage(ce) && will_have_skip_worktree(ce, o))
ce->ce_flags |= CE_SKIP_WORKTREE;
else
ce->ce_flags &= ~CE_SKIP_WORKTREE;
/*
* if (!was_skip_worktree && !ce_skip_worktree()) {
* This is perfectly normal. Move on;
* }
*/
/*
* Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout
* area as a result of ce_skip_worktree() shortcuts in
* verify_absent() and verify_uptodate().
* Make sure they don't modify worktree if they are already
* outside checkout area
*/
if (was_skip_worktree && ce_skip_worktree(ce)) {
ce->ce_flags &= ~CE_UPDATE;
/*
* By default, when CE_REMOVE is on, CE_WT_REMOVE is also
* on to get that file removed from both index and worktree.
* If that file is already outside worktree area, don't
* bother remove it.
*/
if (ce->ce_flags & CE_REMOVE)
ce->ce_flags &= ~CE_WT_REMOVE;
}
if (!was_skip_worktree && ce_skip_worktree(ce)) {
/*
* If CE_UPDATE is set, verify_uptodate() must be called already
* also stat info may have lost after merged_entry() so calling
* verify_uptodate() again may fail
*/
if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
return -1;
ce->ce_flags |= CE_WT_REMOVE;
}
if (was_skip_worktree && !ce_skip_worktree(ce)) {
if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
return -1;
ce->ce_flags |= CE_UPDATE;
}
return 0;
}
static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o)
{
int ret = o->fn(src, o);
if (ret > 0)
ret = 0;
return ret;
}
static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o)
{
ce->ce_flags |= CE_UNPACKED;
if (o->cache_bottom < o->src_index->cache_nr &&
o->src_index->cache[o->cache_bottom] == ce) {
int bottom = o->cache_bottom;
while (bottom < o->src_index->cache_nr &&
o->src_index->cache[bottom]->ce_flags & CE_UNPACKED)
bottom++;
o->cache_bottom = bottom;
}
}
static void mark_all_ce_unused(struct index_state *index)
{
int i;
for (i = 0; i < index->cache_nr; i++)
index->cache[i]->ce_flags &= ~CE_UNPACKED;
}
static int locate_in_src_index(struct cache_entry *ce,
struct unpack_trees_options *o)
{
struct index_state *index = o->src_index;
int len = ce_namelen(ce);
int pos = index_name_pos(index, ce->name, len);
if (pos < 0)
pos = -1 - pos;
return pos;
}
/*
* We call unpack_index_entry() with an unmerged cache entry
* only in diff-index, and it wants a single callback. Skip
* the other unmerged entry with the same name.
*/
static void mark_ce_used_same_name(struct cache_entry *ce,
struct unpack_trees_options *o)
{
struct index_state *index = o->src_index;
int len = ce_namelen(ce);
int pos;
for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) {
struct cache_entry *next = index->cache[pos];
if (len != ce_namelen(next) ||
memcmp(ce->name, next->name, len))
break;
mark_ce_used(next, o);
}
}
static struct cache_entry *next_cache_entry(struct unpack_trees_options *o)
{
const struct index_state *index = o->src_index;
int pos = o->cache_bottom;
while (pos < index->cache_nr) {
struct cache_entry *ce = index->cache[pos];
if (!(ce->ce_flags & CE_UNPACKED))
return ce;
pos++;
}
return NULL;
}
static void add_same_unmerged(struct cache_entry *ce,
struct unpack_trees_options *o)
{
struct index_state *index = o->src_index;
int len = ce_namelen(ce);
int pos = index_name_pos(index, ce->name, len);
if (0 <= pos)
die("programming error in a caller of mark_ce_used_same_name");
for (pos = -pos - 1; pos < index->cache_nr; pos++) {
struct cache_entry *next = index->cache[pos];
if (len != ce_namelen(next) ||
memcmp(ce->name, next->name, len))
break;
add_entry(o, next, 0, 0);
mark_ce_used(next, o);
}
}
static int unpack_index_entry(struct cache_entry *ce,
struct unpack_trees_options *o)
{
struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
int ret;
src[0] = ce;
mark_ce_used(ce, o);
if (ce_stage(ce)) {
if (o->skip_unmerged) {
add_entry(o, ce, 0, 0);
return 0;
}
}
ret = call_unpack_fn(src, o);
if (ce_stage(ce))
mark_ce_used_same_name(ce, o);
return ret;
}
static int find_cache_pos(struct traverse_info *, const struct name_entry *);
static void restore_cache_bottom(struct traverse_info *info, int bottom)
{
struct unpack_trees_options *o = info->data;
if (o->diff_index_cached)
return;
o->cache_bottom = bottom;
}
static int switch_cache_bottom(struct traverse_info *info)
{
struct unpack_trees_options *o = info->data;
int ret, pos;
if (o->diff_index_cached)
return 0;
ret = o->cache_bottom;
pos = find_cache_pos(info->prev, &info->name);
if (pos < -1)
o->cache_bottom = -2 - pos;
else if (pos < 0)
o->cache_bottom = o->src_index->cache_nr;
return ret;
}
static int fast_forward_merge(int n, unsigned long dirmask,
struct name_entry *names,
struct traverse_info *info);
static int traverse_trees_recursive(int n, unsigned long dirmask,
unsigned long df_conflicts,
struct name_entry *names,
struct traverse_info *info)
{
int i, ret, bottom;
struct tree_desc t[MAX_UNPACK_TREES];
void *buf[MAX_UNPACK_TREES];
struct traverse_info newinfo;
struct name_entry *p;
if (!df_conflicts) {
int status = fast_forward_merge(n, dirmask, names, info);
if (status)
return status;
}
p = names;
while (!p->mode)
p++;
newinfo = *info;
newinfo.prev = info;
newinfo.name = *p;
newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 1;
newinfo.conflicts |= df_conflicts;
for (i = 0; i < n; i++, dirmask >>= 1) {
const unsigned char *sha1 = NULL;
if (dirmask & 1)
sha1 = names[i].sha1;
buf[i] = fill_tree_descriptor(t+i, sha1);
}
bottom = switch_cache_bottom(&newinfo);
ret = traverse_trees(n, t, &newinfo);
restore_cache_bottom(&newinfo, bottom);
for (i = 0; i < n; i++)
free(buf[i]);
return ret;
}
/*
* Compare the traverse-path to the cache entry without actually
* having to generate the textual representation of the traverse
* path.
*
* NOTE! This *only* compares up to the size of the traverse path
* itself - the caller needs to do the final check for the cache
* entry having more data at the end!
*/
static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
{
int len, pathlen, ce_len;
const char *ce_name;
if (info->prev) {
int cmp = do_compare_entry(ce, info->prev, &info->name);
if (cmp)
return cmp;
}
pathlen = info->pathlen;
ce_len = ce_namelen(ce);
/* If ce_len < pathlen then we must have previously hit "name == directory" entry */
if (ce_len < pathlen)
return -1;
ce_len -= pathlen;
ce_name = ce->name + pathlen;
len = tree_entry_len(n->path, n->sha1);
return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
}
static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n)
{
int cmp = do_compare_entry(ce, info, n);
if (cmp)
return cmp;
/*
* Even if the beginning compared identically, the ce should
* compare as bigger than a directory leading up to it!
*/
return ce_namelen(ce) > traverse_path_len(info, n);
}
static int ce_in_traverse_path(const struct cache_entry *ce,
const struct traverse_info *info)
{
if (!info->prev)
return 1;
if (do_compare_entry(ce, info->prev, &info->name))
return 0;
/*
* If ce (blob) is the same name as the path (which is a tree
* we will be descending into), it won't be inside it.
*/
return (info->pathlen < ce_namelen(ce));
}
static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage)
{
int len = traverse_path_len(info, n);
struct cache_entry *ce = xcalloc(1, cache_entry_size(len));
ce->ce_mode = create_ce_mode(n->mode);
ce->ce_flags = create_ce_flags(len, stage);
hashcpy(ce->sha1, n->sha1);
make_traverse_path(ce->name, info, n);
return ce;
}
static int unpack_nondirectories(int n, unsigned long mask,
unsigned long dirmask,
struct cache_entry **src,
const struct name_entry *names,
const struct traverse_info *info)
{
int i;
struct unpack_trees_options *o = info->data;
unsigned long conflicts;
/* Do we have *only* directories? Nothing to do */
if (mask == dirmask && !src[0])
return 0;
conflicts = info->conflicts;
if (o->merge)
conflicts >>= 1;
conflicts |= dirmask;
/*
* Ok, we've filled in up to any potential index entry in src[0],
* now do the rest.
*/
for (i = 0; i < n; i++) {
int stage;
unsigned int bit = 1ul << i;
if (conflicts & bit) {
src[i + o->merge] = o->df_conflict_entry;
continue;
}
if (!(mask & bit))
continue;
if (!o->merge)
stage = 0;
else if (i + 1 < o->head_idx)
stage = 1;
else if (i + 1 > o->head_idx)
stage = 3;
else
stage = 2;
src[i + o->merge] = create_ce_entry(info, names + i, stage);
}
if (o->merge)
return call_unpack_fn(src, o);
for (i = 0; i < n; i++)
if (src[i] && src[i] != o->df_conflict_entry)
add_entry(o, src[i], 0, 0);
return 0;
}
static int unpack_failed(struct unpack_trees_options *o, const char *message)
{
discard_index(&o->result);
if (!o->gently) {
if (message)
return error("%s", message);
return -1;
}
return -1;
}
/* NEEDSWORK: give this a better name and share with tree-walk.c */
static int name_compare(const char *a, int a_len,
const char *b, int b_len)
{
int len = (a_len < b_len) ? a_len : b_len;
int cmp = memcmp(a, b, len);
if (cmp)
return cmp;
return (a_len - b_len);
}
/*
* The tree traversal is looking at name p. If we have a matching entry,
* return it. If name p is a directory in the index, do not return
* anything, as we will want to match it when the traversal descends into
* the directory.
*/
static int find_cache_pos(struct traverse_info *info,
const struct name_entry *p)
{
int pos;
struct unpack_trees_options *o = info->data;
struct index_state *index = o->src_index;
int pfxlen = info->pathlen;
int p_len = tree_entry_len(p->path, p->sha1);
for (pos = o->cache_bottom; pos < index->cache_nr; pos++) {
struct cache_entry *ce = index->cache[pos];
const char *ce_name, *ce_slash;
int cmp, ce_len;
if (ce->ce_flags & CE_UNPACKED) {
/*
* cache_bottom entry is already unpacked, so
* we can never match it; don't check it
* again.
*/
if (pos == o->cache_bottom)
++o->cache_bottom;
continue;
}
if (!ce_in_traverse_path(ce, info))
continue;
ce_name = ce->name + pfxlen;
ce_slash = strchr(ce_name, '/');
if (ce_slash)
ce_len = ce_slash - ce_name;
else
ce_len = ce_namelen(ce) - pfxlen;
cmp = name_compare(p->path, p_len, ce_name, ce_len);
/*
* Exact match; if we have a directory we need to
* delay returning it.
*/
if (!cmp)
return ce_slash ? -2 - pos : pos;
if (0 < cmp)
continue; /* keep looking */
/*
* ce_name sorts after p->path; could it be that we
* have files under p->path directory in the index?
* E.g. ce_name == "t-i", and p->path == "t"; we may
* have "t/a" in the index.
*/
if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) &&
ce_name[p_len] < '/')
continue; /* keep looking */
break;
}
return -1;
}
static struct cache_entry *find_cache_entry(struct traverse_info *info,
const struct name_entry *p)
{
int pos = find_cache_pos(info, p);
struct unpack_trees_options *o = info->data;
if (0 <= pos)
return o->src_index->cache[pos];
else
return NULL;
}
static int fast_forward_merge(int n, unsigned long dirmask,
struct name_entry *names,
struct traverse_info *info)
{
int i;
struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
struct unpack_trees_options *o = info->data;
/* merging two or more trees with an identical subdirectory? */
if ((n < 2) || ((1UL << n) - 1) != dirmask ||
!o->merge || o->reset || o->initial_checkout)
return 0;
for (i = 1; i < n; i++)
if (hashcmp(names[i-1].sha1, names[i].sha1))
return 0;
/*
* Instead of descending into the directory, keep the contents
* of the current index.
*/
while (1) {
struct cache_entry *ce;
ce = next_cache_entry(o);
if (!ce)
break;
/* Is the entry still in that directory? */
if (do_compare_entry(ce, info, names))
break;
/*
* Note: we do not just run unpack_index_entry() here,
* as the callback may want to compare what is in the
* index with what are from the HEAD and the other tree
* and reject the merge. We pretend that ancestors, the
* HEAD and the other tree all have the same contents as
* the current index, which is a lie, but it works.
*/
for (i = 0; i < n + 1; i++)
src[i] = ce;
mark_ce_used(ce, o);
if (call_unpack_fn(src, o) < 0)
return unpack_failed(o, NULL);
if (ce_stage(ce))
mark_ce_used_same_name(ce, o);
}
return dirmask;
}
static void debug_path(struct traverse_info *info)
{
if (info->prev) {
debug_path(info->prev);
if (*info->prev->name.path)
putchar('/');
}
printf("%s", info->name.path);
}
static void debug_name_entry(int i, struct name_entry *n)
{
printf("ent#%d %06o %s\n", i,
n->path ? n->mode : 0,
n->path ? n->path : "(missing)");
}
static void debug_unpack_callback(int n,
unsigned long mask,
unsigned long dirmask,
struct name_entry *names,
struct traverse_info *info)
{
int i;
printf("* unpack mask %lu, dirmask %lu, cnt %d ",
mask, dirmask, n);
debug_path(info);
putchar('\n');
for (i = 0; i < n; i++)
debug_name_entry(i, names + i);
}
static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info)
{
struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
struct unpack_trees_options *o = info->data;
const struct name_entry *p = names;
/* Find first entry with a real name (we could use "mask" too) */
while (!p->mode)
p++;
if (o->debug_unpack)
debug_unpack_callback(n, mask, dirmask, names, info);
/* Are we supposed to look at the index too? */
if (o->merge) {
while (1) {
int cmp;
struct cache_entry *ce;
if (o->diff_index_cached)
ce = next_cache_entry(o);
else
ce = find_cache_entry(info, p);
if (!ce)
break;
cmp = compare_entry(ce, info, p);
if (cmp < 0) {
if (unpack_index_entry(ce, o) < 0)
return unpack_failed(o, NULL);
continue;
}
if (!cmp) {
if (ce_stage(ce)) {
/*
* If we skip unmerged index
* entries, we'll skip this
* entry *and* the tree
* entries associated with it!
*/
if (o->skip_unmerged) {
add_same_unmerged(ce, o);
return mask;
}
}
src[0] = ce;
}
break;
}
}
if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0)
return -1;
if (src[0]) {
if (ce_stage(src[0]))
mark_ce_used_same_name(src[0], o);
else
mark_ce_used(src[0], o);
}
/* Now handle any directories.. */
if (dirmask) {
unsigned long conflicts = mask & ~dirmask;
if (o->merge) {
conflicts <<= 1;
if (src[0])
conflicts |= 1;
}
/* special case: "diff-index --cached" looking at a tree */
if (o->diff_index_cached &&
n == 1 && dirmask == 1 && S_ISDIR(names->mode)) {
int matches;
matches = cache_tree_matches_traversal(o->src_index->cache_tree,
names, info);
/*
* Everything under the name matches; skip the
* entire hierarchy. diff_index_cached codepath
* special cases D/F conflicts in such a way that
* it does not do any look-ahead, so this is safe.
*/
if (matches) {
o->cache_bottom += matches;
return mask;
}
}
if (traverse_trees_recursive(n, dirmask, conflicts,
names, info) < 0)
return -1;
return mask;
}
return mask;
}
/*
* N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the
* resulting index, -2 on failure to reflect the changes to the work tree.
*/
int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
{
int i, ret;
static struct cache_entry *dfc;
struct exclude_list el;
if (len > MAX_UNPACK_TREES)
die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
memset(&state, 0, sizeof(state));
state.base_dir = "";
state.force = 1;
state.quiet = 1;
state.refresh_cache = 1;
memset(&el, 0, sizeof(el));
if (!core_apply_sparse_checkout || !o->update)
o->skip_sparse_checkout = 1;
if (!o->skip_sparse_checkout) {
if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, NULL, &el, 0) < 0)
o->skip_sparse_checkout = 1;
else
o->el = &el;
}
memset(&o->result, 0, sizeof(o->result));
o->result.initialized = 1;
o->result.timestamp.sec = o->src_index->timestamp.sec;
o->result.timestamp.nsec = o->src_index->timestamp.nsec;
o->merge_size = len;
mark_all_ce_unused(o->src_index);
if (!dfc)
dfc = xcalloc(1, cache_entry_size(0));
o->df_conflict_entry = dfc;
if (len) {
const char *prefix = o->prefix ? o->prefix : "";
struct traverse_info info;
setup_traverse_info(&info, prefix);
info.fn = unpack_callback;
info.data = o;
info.show_all_errors = o->show_all_errors;
if (o->prefix) {
/*
* Unpack existing index entries that sort before the
* prefix the tree is spliced into. Note that o->merge
* is always true in this case.
*/
while (1) {
struct cache_entry *ce = next_cache_entry(o);
if (!ce)
break;
if (ce_in_traverse_path(ce, &info))
break;
if (unpack_index_entry(ce, o) < 0)
goto return_failed;
}
}
if (traverse_trees(len, t, &info) < 0)
goto return_failed;
}
/* Any left-over entries in the index? */
if (o->merge) {
while (1) {
struct cache_entry *ce = next_cache_entry(o);
if (!ce)
break;
if (unpack_index_entry(ce, o) < 0)
goto return_failed;
}
}
mark_all_ce_unused(o->src_index);
if (o->trivial_merges_only && o->nontrivial_merge) {
ret = unpack_failed(o, "Merge requires file-level merging");
goto done;
}
if (!o->skip_sparse_checkout) {
int empty_worktree = 1;
for (i = 0; i < o->result.cache_nr; i++) {
struct cache_entry *ce = o->result.cache[i];
if (apply_sparse_checkout(ce, o)) {
ret = -1;
goto done;
}
if (!ce_skip_worktree(ce))
empty_worktree = 0;
}
if (o->result.cache_nr && empty_worktree) {
/* dubious---why should this fail??? */
ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
goto done;
}
}
o->src_index = NULL;
ret = check_updates(o) ? (-2) : 0;
if (o->dst_index)
*o->dst_index = o->result;
done:
for (i = 0; i < el.nr; i++)
free(el.excludes[i]);
if (el.excludes)
free(el.excludes);
return ret;
return_failed:
if (o->show_all_errors)
display_error_msgs(o);
mark_all_ce_unused(o->src_index);
ret = unpack_failed(o, NULL);
goto done;
}
/* Here come the merge functions */
static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
{
return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
}
static int same(struct cache_entry *a, struct cache_entry *b)
{
if (!!a != !!b)
return 0;
if (!a && !b)
return 1;
if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
return 0;
return a->ce_mode == b->ce_mode &&
!hashcmp(a->sha1, b->sha1);
}
/*
* When a CE gets turned into an unmerged entry, we
* want it to be up-to-date
*/
static int verify_uptodate_1(struct cache_entry *ce,
struct unpack_trees_options *o,
enum unpack_trees_error_types error_type)
{
struct stat st;
if (o->index_only || (!((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) && (o->reset || ce_uptodate(ce))))
return 0;
if (!lstat(ce->name, &st)) {
unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
if (!changed)
return 0;
/*
* NEEDSWORK: the current default policy is to allow
* submodule to be out of sync wrt the supermodule
* index. This needs to be tightened later for
* submodules that are marked to be automatically
* checked out.
*/
if (S_ISGITLINK(ce->ce_mode))
return 0;
errno = 0;
}
if (errno == ENOENT)
return 0;
return o->gently ? -1 :
add_rejected_path(o, error_type, ce->name);
}
static int verify_uptodate(struct cache_entry *ce,
struct unpack_trees_options *o)
{
if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
return 0;
return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
}
static int verify_uptodate_sparse(struct cache_entry *ce,
struct unpack_trees_options *o)
{
return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
}
static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
{
if (ce)
cache_tree_invalidate_path(o->src_index->cache_tree, ce->name);
}
/*
* Check that checking out ce->sha1 in subdir ce->name is not
* going to overwrite any working files.
*
* Currently, git does not checkout subprojects during a superproject
* checkout, so it is not going to overwrite anything.
*/
static int verify_clean_submodule(struct cache_entry *ce,
enum unpack_trees_error_types error_type,
struct unpack_trees_options *o)
{
return 0;
}
static int verify_clean_subdirectory(struct cache_entry *ce,
enum unpack_trees_error_types error_type,
struct unpack_trees_options *o)
{
/*
* we are about to extract "ce->name"; we would not want to lose
* anything in the existing directory there.
*/
int namelen;
int i;
struct dir_struct d;
char *pathbuf;
int cnt = 0;
unsigned char sha1[20];
if (S_ISGITLINK(ce->ce_mode) &&
resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) {
/* If we are not going to update the submodule, then
* we don't care.
*/
if (!hashcmp(sha1, ce->sha1))
return 0;
return verify_clean_submodule(ce, error_type, o);
}
/*
* First let's make sure we do not have a local modification
* in that directory.
*/
namelen = strlen(ce->name);
for (i = locate_in_src_index(ce, o);
i < o->src_index->cache_nr;
i++) {
struct cache_entry *ce2 = o->src_index->cache[i];
int len = ce_namelen(ce2);
if (len < namelen ||
strncmp(ce->name, ce2->name, namelen) ||
ce2->name[namelen] != '/')
break;
/*
* ce2->name is an entry in the subdirectory to be
* removed.
*/
if (!ce_stage(ce2)) {
if (verify_uptodate(ce2, o))
return -1;
add_entry(o, ce2, CE_REMOVE, 0);
mark_ce_used(ce2, o);
}
cnt++;
}
/*
* Then we need to make sure that we do not lose a locally
* present file that is not ignored.
*/
pathbuf = xmalloc(namelen + 2);
memcpy(pathbuf, ce->name, namelen);
strcpy(pathbuf+namelen, "/");
memset(&d, 0, sizeof(d));
if (o->dir)
d.exclude_per_dir = o->dir->exclude_per_dir;
i = read_directory(&d, pathbuf, namelen+1, NULL);
if (i)
return o->gently ? -1 :
add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
free(pathbuf);
return cnt;
}
/*
* This gets called when there was no index entry for the tree entry 'dst',
* but we found a file in the working tree that 'lstat()' said was fine,
* and we're on a case-insensitive filesystem.
*
* See if we can find a case-insensitive match in the index that also
* matches the stat information, and assume it's that other file!
*/
static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
{
struct cache_entry *src;
src = index_name_exists(o->src_index, name, len, 1);
return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
}
static int check_ok_to_remove(const char *name, int len, int dtype,
struct cache_entry *ce, struct stat *st,
enum unpack_trees_error_types error_type,
struct unpack_trees_options *o)
{
struct cache_entry *result;
/*
* It may be that the 'lstat()' succeeded even though
* target 'ce' was absent, because there is an old
* entry that is different only in case..
*
* Ignore that lstat() if it matches.
*/
if (ignore_case && icase_exists(o, name, len, st))
return 0;
if (o->dir && excluded(o->dir, name, &dtype))
/*
* ce->name is explicitly excluded, so it is Ok to
* overwrite it.
*/
return 0;
if (S_ISDIR(st->st_mode)) {
/*
* We are checking out path "foo" and
* found "foo/." in the working tree.
* This is tricky -- if we have modified
* files that are in "foo/" we would lose
* them.
*/
if (verify_clean_subdirectory(ce, error_type, o) < 0)
return -1;
return 0;
}
/*
* The previous round may already have decided to
* delete this path, which is in a subdirectory that
* is being replaced with a blob.
*/
result = index_name_exists(&o->result, name, len, 0);
if (result) {
if (result->ce_flags & CE_REMOVE)
return 0;
}
return o->gently ? -1 :
add_rejected_path(o, error_type, name);
}
/*
* We do not want to remove or overwrite a working tree file that
* is not tracked, unless it is ignored.
*/
static int verify_absent_1(struct cache_entry *ce,
enum unpack_trees_error_types error_type,
struct unpack_trees_options *o)
{
int len;
struct stat st;
if (o->index_only || o->reset || !o->update)
return 0;
len = check_leading_path(ce->name, ce_namelen(ce));
if (!len)
return 0;
else if (len > 0) {
char path[PATH_MAX + 1];
memcpy(path, ce->name, len);
path[len] = 0;
lstat(path, &st);
return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
error_type, o);
} else if (!lstat(ce->name, &st))
return check_ok_to_remove(ce->name, ce_namelen(ce),
ce_to_dtype(ce), ce, &st,
error_type, o);
return 0;
}
static int verify_absent(struct cache_entry *ce,
enum unpack_trees_error_types error_type,
struct unpack_trees_options *o)
{
if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
return 0;
return verify_absent_1(ce, error_type, o);
}
static int verify_absent_sparse(struct cache_entry *ce,
enum unpack_trees_error_types error_type,
struct unpack_trees_options *o)
{
enum unpack_trees_error_types orphaned_error = error_type;
if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
return verify_absent_1(ce, orphaned_error, o);
}
static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
struct unpack_trees_options *o)
{
int update = CE_UPDATE;
if (!old) {
if (verify_absent(merge, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
return -1;
if (!o->skip_sparse_checkout && will_have_skip_worktree(merge, o))
update |= CE_SKIP_WORKTREE;
invalidate_ce_path(merge, o);
} else if (!(old->ce_flags & CE_CONFLICTED)) {
/*
* See if we can re-use the old CE directly?
* That way we get the uptodate stat info.
*
* This also removes the UPDATE flag on a match; otherwise
* we will end up overwriting local changes in the work tree.
*/
if (same(old, merge)) {
copy_cache_entry(merge, old);
update = 0;
} else {
if (verify_uptodate(old, o))
return -1;
if (ce_skip_worktree(old))
update |= CE_SKIP_WORKTREE;
invalidate_ce_path(old, o);
}
} else {
/*
* Previously unmerged entry left as an existence
* marker by read_index_unmerged();
*/
invalidate_ce_path(old, o);
}
add_entry(o, merge, update, CE_STAGEMASK);
return 1;
}
static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
struct unpack_trees_options *o)
{
/* Did it exist in the index? */
if (!old) {
if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
return -1;
return 0;
}
if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o))
return -1;
add_entry(o, ce, CE_REMOVE, 0);
invalidate_ce_path(ce, o);
return 1;
}
static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o)
{
add_entry(o, ce, 0, 0);
return 1;
}
#if DBRT_DEBUG
static void show_stage_entry(FILE *o,
const char *label, const struct cache_entry *ce)
{
if (!ce)
fprintf(o, "%s (missing)\n", label);
else
fprintf(o, "%s%06o %s %d\t%s\n",
label,
ce->ce_mode,
sha1_to_hex(ce->sha1),
ce_stage(ce),
ce->name);
}
#endif
int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
{
struct cache_entry *index;
struct cache_entry *head;
struct cache_entry *remote = stages[o->head_idx + 1];
int count;
int head_match = 0;
int remote_match = 0;
int df_conflict_head = 0;
int df_conflict_remote = 0;
int any_anc_missing = 0;
int no_anc_exists = 1;
int i;
for (i = 1; i < o->head_idx; i++) {
if (!stages[i] || stages[i] == o->df_conflict_entry)
any_anc_missing = 1;
else
no_anc_exists = 0;
}
index = stages[0];
head = stages[o->head_idx];
if (head == o->df_conflict_entry) {
df_conflict_head = 1;
head = NULL;
}
if (remote == o->df_conflict_entry) {
df_conflict_remote = 1;
remote = NULL;
}
/*
* First, if there's a #16 situation, note that to prevent #13
* and #14.
*/
if (!same(remote, head)) {
for (i = 1; i < o->head_idx; i++) {
if (same(stages[i], head)) {
head_match = i;
}
if (same(stages[i], remote)) {
remote_match = i;
}
}
}
/*
* We start with cases where the index is allowed to match
* something other than the head: #14(ALT) and #2ALT, where it
* is permitted to match the result instead.
*/
/* #14, #14ALT, #2ALT */
if (remote && !df_conflict_head && head_match && !remote_match) {
if (index && !same(index, remote) && !same(index, head))
return o->gently ? -1 : reject_merge(index, o);
return merged_entry(remote, index, o);
}
/*
* If we have an entry in the index cache, then we want to
* make sure that it matches head.
*/
if (index && !same(index, head))
return o->gently ? -1 : reject_merge(index, o);
if (head) {
/* #5ALT, #15 */
if (same(head, remote))
return merged_entry(head, index, o);
/* #13, #3ALT */
if (!df_conflict_remote && remote_match && !head_match)
return merged_entry(head, index, o);
}
/* #1 */
if (!head && !remote && any_anc_missing)
return 0;
/*
* Under the "aggressive" rule, we resolve mostly trivial
* cases that we historically had git-merge-one-file resolve.
*/
if (o->aggressive) {
int head_deleted = !head;
int remote_deleted = !remote;
struct cache_entry *ce = NULL;
if (index)
ce = index;
else if (head)
ce = head;
else if (remote)
ce = remote;
else {
for (i = 1; i < o->head_idx; i++) {
if (stages[i] && stages[i] != o->df_conflict_entry) {
ce = stages[i];
break;
}
}
}
/*
* Deleted in both.
* Deleted in one and unchanged in the other.
*/
if ((head_deleted && remote_deleted) ||
(head_deleted && remote && remote_match) ||
(remote_deleted && head && head_match)) {
if (index)
return deleted_entry(index, index, o);
if (ce && !head_deleted) {
if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
return -1;
}
return 0;
}
/*
* Added in both, identically.
*/
if (no_anc_exists && head && remote && same(head, remote))
return merged_entry(head, index, o);
}
/* Below are "no merge" cases, which require that the index be
* up-to-date to avoid the files getting overwritten with
* conflict resolution files.
*/
if (index) {
if (verify_uptodate(index, o))
return -1;
}
o->nontrivial_merge = 1;
/* #2, #3, #4, #6, #7, #9, #10, #11. */
count = 0;
if (!head_match || !remote_match) {
for (i = 1; i < o->head_idx; i++) {
if (stages[i] && stages[i] != o->df_conflict_entry) {
keep_entry(stages[i], o);
count++;
break;
}
}
}
#if DBRT_DEBUG
else {
fprintf(stderr, "read-tree: warning #16 detected\n");
show_stage_entry(stderr, "head ", stages[head_match]);
show_stage_entry(stderr, "remote ", stages[remote_match]);
}
#endif
if (head) { count += keep_entry(head, o); }
if (remote) { count += keep_entry(remote, o); }
return count;
}
/*
* Two-way merge.
*
* The rule is to "carry forward" what is in the index without losing
* information across a "fast-forward", favoring a successful merge
* over a merge failure when it makes sense. For details of the
* "carry forward" rule, please see <Documentation/git-read-tree.txt>.
*
*/
int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o)
{
struct cache_entry *current = src[0];
struct cache_entry *oldtree = src[1];
struct cache_entry *newtree = src[2];
if (o->merge_size != 2)
return error("Cannot do a twoway merge of %d trees",
o->merge_size);
if (oldtree == o->df_conflict_entry)
oldtree = NULL;
if (newtree == o->df_conflict_entry)
newtree = NULL;
if (current) {
if ((!oldtree && !newtree) || /* 4 and 5 */
(!oldtree && newtree &&
same(current, newtree)) || /* 6 and 7 */
(oldtree && newtree &&
same(oldtree, newtree)) || /* 14 and 15 */
(oldtree && newtree &&
!same(oldtree, newtree) && /* 18 and 19 */
same(current, newtree))) {
return keep_entry(current, o);
}
else if (oldtree && !newtree && same(current, oldtree)) {
/* 10 or 11 */
return deleted_entry(oldtree, current, o);
}
else if (oldtree && newtree &&
same(current, oldtree) && !same(current, newtree)) {
/* 20 or 21 */
return merged_entry(newtree, current, o);
}
else {
/* all other failures */
if (oldtree)
return o->gently ? -1 : reject_merge(oldtree, o);
if (current)
return o->gently ? -1 : reject_merge(current, o);
if (newtree)
return o->gently ? -1 : reject_merge(newtree, o);
return -1;
}
}
else if (newtree) {
if (oldtree && !o->initial_checkout) {
/*
* deletion of the path was staged;
*/
if (same(oldtree, newtree))
return 1;
return reject_merge(oldtree, o);
}
return merged_entry(newtree, current, o);
}
return deleted_entry(oldtree, current, o);
}
/*
* Bind merge.
*
* Keep the index entries at stage0, collapse stage1 but make sure
* stage0 does not have anything there.
*/
int bind_merge(struct cache_entry **src,
struct unpack_trees_options *o)
{
struct cache_entry *old = src[0];
struct cache_entry *a = src[1];
if (o->merge_size != 1)
return error("Cannot do a bind merge of %d trees\n",
o->merge_size);
if (a && old)
return o->gently ? -1 :
error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
if (!a)
return keep_entry(old, o);
else
return merged_entry(a, NULL, o);
}
/*
* One-way merge.
*
* The rule is:
* - take the stat information from stage0, take the data from stage1
*/
int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o)
{
struct cache_entry *old = src[0];
struct cache_entry *a = src[1];
if (o->merge_size != 1)
return error("Cannot do a oneway merge of %d trees",
o->merge_size);
if (!a || a == o->df_conflict_entry)
return deleted_entry(old, old, o);
if (old && same(old, a)) {
int update = 0;
if (o->reset && !ce_uptodate(old) && !ce_skip_worktree(old)) {
struct stat st;
if (lstat(old->name, &st) ||
ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE))
update |= CE_UPDATE;
}
add_entry(o, old, update, 0);
return 0;
}
return merged_entry(a, old, o);
}