git/unpack-trees.c
Junio C Hamano 54dc783766 Merge branch 'bd/maint-unpack-trees-parawalk-fix' into maint
* bd/maint-unpack-trees-parawalk-fix:
  unpack-trees: Make index lookahead less pessimal
2010-06-28 16:18:02 -07:00

1451 lines
36 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" replaces not_uptodate_file to
* explain why it does not allow switching between branches when you have
* local changes, for example.
*/
static struct unpack_trees_error_msgs unpack_plumbing_errors = {
/* would_overwrite */
"Entry '%s' would be overwritten by merge. Cannot merge.",
/* not_uptodate_file */
"Entry '%s' not uptodate. Cannot merge.",
/* not_uptodate_dir */
"Updating '%s' would lose untracked files in it",
/* would_lose_untracked */
"Untracked working tree file '%s' would be %s by merge.",
/* bind_overlap */
"Entry '%s' overlaps with '%s'. Cannot bind.",
/* sparse_not_uptodate_file */
"Entry '%s' not uptodate. Cannot update sparse checkout.",
/* would_lose_orphaned */
"Working tree file '%s' would be %s by sparse checkout update.",
};
#define ERRORMSG(o,fld) \
( ((o) && (o)->msgs.fld) \
? ((o)->msgs.fld) \
: (unpack_plumbing_errors.fld) )
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;
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);
}
/*
* 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 (has_symlink_or_noent_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_REMOVE | 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;
}
if (ce->ce_flags & CE_REMOVE) {
display_progress(progress, ++cnt);
if (o->update)
unlink_entry(ce);
}
}
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, const char *action, struct unpack_trees_options *o);
static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
{
const char *basename;
if (ce_stage(ce))
return 0;
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 (will_have_skip_worktree(ce, o))
ce->ce_flags |= CE_SKIP_WORKTREE;
else
ce->ce_flags &= ~CE_SKIP_WORKTREE;
/*
* We only care about files getting into the checkout area
* If merge strategies want to remove some, go ahead, this
* flag will be removed eventually in unpack_trees() if it's
* outside checkout area.
*/
if (ce->ce_flags & CE_REMOVE)
return 0;
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, "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[5] = { ce, NULL, };
int ret;
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 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];
struct traverse_info newinfo;
struct name_entry *p;
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;
fill_tree_descriptor(t+i, sha1);
}
bottom = switch_cache_bottom(&newinfo);
ret = traverse_trees(n, t, &newinfo);
restore_cache_bottom(&newinfo, bottom);
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 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;
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;
}
/*
* 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(). Clear them.
*/
if (ce_skip_worktree(ce))
ce->ce_flags &= ~(CE_UPDATE | CE_REMOVE);
else
empty_worktree = 0;
}
if (o->result.cache_nr && empty_worktree) {
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:
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 error(ERRORMSG(o, 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,
const char *error_msg)
{
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 :
error(error_msg, 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, ERRORMSG(o, not_uptodate_file));
}
static int verify_uptodate_sparse(struct cache_entry *ce,
struct unpack_trees_options *o)
{
return verify_uptodate_1(ce, o, ERRORMSG(o, 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, const char *action,
struct unpack_trees_options *o)
{
return 0;
}
static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
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, action, 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 :
error(ERRORMSG(o, 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, struct cache_entry *dst, struct stat *st)
{
struct cache_entry *src;
src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
}
/*
* 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, const char *action,
struct unpack_trees_options *o,
const char *error_msg)
{
struct stat st;
if (o->index_only || o->reset || !o->update)
return 0;
if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
return 0;
if (!lstat(ce->name, &st)) {
int dtype = ce_to_dtype(ce);
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, ce, &st))
return 0;
if (o->dir && excluded(o->dir, ce->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, action, 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, ce->name, ce_namelen(ce), 0);
if (result) {
if (result->ce_flags & CE_REMOVE)
return 0;
}
return o->gently ? -1 :
error(ERRORMSG(o, would_lose_untracked), ce->name, action);
}
return 0;
}
static int verify_absent(struct cache_entry *ce, const char *action,
struct unpack_trees_options *o)
{
if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
return 0;
return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
}
static int verify_absent_sparse(struct cache_entry *ce, const char *action,
struct unpack_trees_options *o)
{
return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
}
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, "overwritten", o))
return -1;
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, "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, "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, 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);
}