mirrors-c
/
git
mirror of https://github.com/git/git.git
2
0
Fork 0
Code Issues Projects Releases Wiki Activity Software Blog
git/merge-ort.c

5143 lines
164 KiB
C
Raw Blame History

/*
* "Ostensibly Recursive's Twin" merge strategy, or "ort" for short. Meant
* as a drop-in replacement for the "recursive" merge strategy, allowing one
* to replace
*
* git merge [-s recursive]
*
* with
*
* git merge -s ort
*
* Note: git's parser allows the space between '-s' and its argument to be
* missing. (Should I have backronymed "ham", "alsa", "kip", "nap, "alvo",
* "cale", "peedy", or "ins" instead of "ort"?)
*/
#include "git-compat-util.h"
#include "merge-ort.h"
#include "alloc.h"
#include "attr.h"
#include "blob.h"
#include "cache-tree.h"
#include "commit.h"
#include "commit-reach.h"
#include "diff.h"
#include "diffcore.h"
#include "dir.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "entry.h"
#include "merge-ll.h"
#include "match-trees.h"
#include "mem-pool.h"
#include "object-name.h"
#include "object-store-ll.h"
#include "oid-array.h"
#include "path.h"
#include "promisor-remote.h"
#include "read-cache-ll.h"
#include "revision.h"
#include "sparse-index.h"
#include "strmap.h"
#include "submodule-config.h"
#include "submodule.h"
#include "trace2.h"
#include "tree.h"
#include "unpack-trees.h"
#include "xdiff-interface.h"
/*
* We have many arrays of size 3. Whenever we have such an array, the
* indices refer to one of the sides of the three-way merge. This is so
* pervasive that the constants 0, 1, and 2 are used in many places in the
* code (especially in arithmetic operations to find the other side's index
* or to compute a relevant mask), but sometimes these enum names are used
* to aid code clarity.
*
* See also 'filemask' and 'dirmask' in struct conflict_info; the "ith side"
* referred to there is one of these three sides.
*/
enum merge_side {
MERGE_BASE = 0,
MERGE_SIDE1 = 1,
MERGE_SIDE2 = 2
};
static unsigned RESULT_INITIALIZED = 0x1abe11ed; /* unlikely accidental value */
struct traversal_callback_data {
unsigned long mask;
unsigned long dirmask;
struct name_entry names[3];
};
struct deferred_traversal_data {
/*
* possible_trivial_merges: directories to be explored only when needed
*
* possible_trivial_merges is a map of directory names to
* dir_rename_mask. When we detect that a directory is unchanged on
* one side, we can sometimes resolve the directory without recursing
* into it. Renames are the only things that can prevent such an
* optimization. However, for rename sources:
* - If no parent directory needed directory rename detection, then
* no path under such a directory can be a relevant_source.
* and for rename destinations:
* - If no cached rename has a target path under the directory AND
* - If there are no unpaired relevant_sources elsewhere in the
* repository
* then we don't need any path under this directory for a rename
* destination. The only way to know the last item above is to defer
* handling such directories until the end of collect_merge_info(),
* in handle_deferred_entries().
*
* For each we store dir_rename_mask, since that's the only bit of
* information we need, other than the path, to resume the recursive
* traversal.
*/
struct strintmap possible_trivial_merges;
/*
* trivial_merges_okay: if trivial directory merges are okay
*
* See possible_trivial_merges above. The "no unpaired
* relevant_sources elsewhere in the repository" is a single boolean
* per merge side, which we store here. Note that while 0 means no,
* 1 only means "maybe" rather than "yes"; we optimistically set it
* to 1 initially and only clear when we determine it is unsafe to
* do trivial directory merges.
*/
unsigned trivial_merges_okay;
/*
* target_dirs: ancestor directories of rename targets
*
* target_dirs contains all directory names that are an ancestor of
* any rename destination.
*/
struct strset target_dirs;
};
struct rename_info {
/*
* All variables that are arrays of size 3 correspond to data tracked
* for the sides in enum merge_side. Index 0 is almost always unused
* because we often only need to track information for MERGE_SIDE1 and
* MERGE_SIDE2 (MERGE_BASE can't have rename information since renames
* are determined relative to what changed since the MERGE_BASE).
*/
/*
* pairs: pairing of filenames from diffcore_rename()
*/
struct diff_queue_struct pairs[3];
/*
* dirs_removed: directories removed on a given side of history.
*
* The keys of dirs_removed[side] are the directories that were removed
* on the given side of history. The value of the strintmap for each
* directory is a value from enum dir_rename_relevance.
*/
struct strintmap dirs_removed[3];
/*
* dir_rename_count: tracking where parts of a directory were renamed to
*
* When files in a directory are renamed, they may not all go to the
* same location. Each strmap here tracks:
* old_dir => {new_dir => int}
* That is, dir_rename_count[side] is a strmap to a strintmap.
*/
struct strmap dir_rename_count[3];
/*
* dir_renames: computed directory renames
*
* This is a map of old_dir => new_dir and is derived in part from
* dir_rename_count.
*/
struct strmap dir_renames[3];
/*
* relevant_sources: deleted paths wanted in rename detection, and why
*
* relevant_sources is a set of deleted paths on each side of
* history for which we need rename detection. If a path is deleted
* on one side of history, we need to detect if it is part of a
* rename if either
* * the file is modified/deleted on the other side of history
* * we need to detect renames for an ancestor directory
* If neither of those are true, we can skip rename detection for
* that path. The reason is stored as a value from enum
* file_rename_relevance, as the reason can inform the algorithm in
* diffcore_rename_extended().
*/
struct strintmap relevant_sources[3];
struct deferred_traversal_data deferred[3];
/*
* dir_rename_mask:
* 0: optimization removing unmodified potential rename source okay
* 2 or 4: optimization okay, but must check for files added to dir
* 7: optimization forbidden; need rename source in case of dir rename
*/
unsigned dir_rename_mask:3;
/*
* callback_data_*: supporting data structures for alternate traversal
*
* We sometimes need to be able to traverse through all the files
* in a given tree before all immediate subdirectories within that
* tree. Since traverse_trees() doesn't do that naturally, we have
* a traverse_trees_wrapper() that stores any immediate
* subdirectories while traversing files, then traverses the
* immediate subdirectories later. These callback_data* variables
* store the information for the subdirectories so that we can do
* that traversal order.
*/
struct traversal_callback_data *callback_data;
int callback_data_nr, callback_data_alloc;
char *callback_data_traverse_path;
/*
* merge_trees: trees passed to the merge algorithm for the merge
*
* merge_trees records the trees passed to the merge algorithm. But,
* this data also is stored in merge_result->priv. If a sequence of
* merges are being done (such as when cherry-picking or rebasing),
* the next merge can look at this and re-use information from
* previous merges under certain circumstances.
*
* See also all the cached_* variables.
*/
struct tree *merge_trees[3];
/*
* cached_pairs_valid_side: which side's cached info can be reused
*
* See the description for merge_trees. For repeated merges, at most
* only one side's cached information can be used. Valid values:
* MERGE_SIDE2: cached data from side2 can be reused
* MERGE_SIDE1: cached data from side1 can be reused
* 0: no cached data can be reused
* -1: See redo_after_renames; both sides can be reused.
*/
int cached_pairs_valid_side;
/*
* cached_pairs: Caching of renames and deletions.
*
* These are mappings recording renames and deletions of individual
* files (not directories). They are thus a map from an old
* filename to either NULL (for deletions) or a new filename (for
* renames).
*/
struct strmap cached_pairs[3];
/*
* cached_target_names: just the destinations from cached_pairs
*
* We sometimes want a fast lookup to determine if a given filename
* is one of the destinations in cached_pairs. cached_target_names
* is thus duplicative information, but it provides a fast lookup.
*/
struct strset cached_target_names[3];
/*
* cached_irrelevant: Caching of rename_sources that aren't relevant.
*
* If we try to detect a rename for a source path and succeed, it's
* part of a rename. If we try to detect a rename for a source path
* and fail, then it's a delete. If we do not try to detect a rename
* for a path, then we don't know if it's a rename or a delete. If
* merge-ort doesn't think the path is relevant, then we just won't
* cache anything for that path. But there's a slight problem in
* that merge-ort can think a path is RELEVANT_LOCATION, but due to
* commit 9bd342137e ("diffcore-rename: determine which
* relevant_sources are no longer relevant", 2021-03-13),
* diffcore-rename can downgrade the path to RELEVANT_NO_MORE. To
* avoid excessive calls to diffcore_rename_extended() we still need
* to cache such paths, though we cannot record them as either
* renames or deletes. So we cache them here as a "turned out to be
* irrelevant *for this commit*" as they are often also irrelevant
* for subsequent commits, though we will have to do some extra
* checking to see whether such paths become relevant for rename
* detection when cherry-picking/rebasing subsequent commits.
*/
struct strset cached_irrelevant[3];
/*
* redo_after_renames: optimization flag for "restarting" the merge
*
* Sometimes it pays to detect renames, cache them, and then
* restart the merge operation from the beginning. The reason for
* this is that when we know where all the renames are, we know
* whether a certain directory has any paths under it affected --
* and if a directory is not affected then it permits us to do
* trivial tree merging in more cases. Doing trivial tree merging
* prevents the need to run process_entry() on every path
* underneath trees that can be trivially merged, and
* process_entry() is more expensive than collect_merge_info() --
* plus, the second collect_merge_info() will be much faster since
* it doesn't have to recurse into the relevant trees.
*
* Values for this flag:
* 0 = don't bother, not worth it (or conditions not yet checked)
* 1 = conditions for optimization met, optimization worthwhile
* 2 = we already did it (don't restart merge yet again)
*/
unsigned redo_after_renames;
/*
* needed_limit: value needed for inexact rename detection to run
*
* If the current rename limit wasn't high enough for inexact
* rename detection to run, this records the limit needed. Otherwise,
* this value remains 0.
*/
int needed_limit;
};
struct merge_options_internal {
/*
* paths: primary data structure in all of merge ort.
*
* The keys of paths:
* * are full relative paths from the toplevel of the repository
* (e.g. "drivers/firmware/raspberrypi.c").
* * store all relevant paths in the repo, both directories and
* files (e.g. drivers, drivers/firmware would also be included)
* * these keys serve to intern all the path strings, which allows
* us to do pointer comparison on directory names instead of
* strcmp; we just have to be careful to use the interned strings.
*
* The values of paths:
* * either a pointer to a merged_info, or a conflict_info struct
* * merged_info contains all relevant information for a
* non-conflicted entry.
* * conflict_info contains a merged_info, plus any additional
* information about a conflict such as the higher orders stages
* involved and the names of the paths those came from (handy
* once renames get involved).
* * a path may start "conflicted" (i.e. point to a conflict_info)
* and then a later step (e.g. three-way content merge) determines
* it can be cleanly merged, at which point it'll be marked clean
* and the algorithm will ignore any data outside the contained
* merged_info for that entry
* * If an entry remains conflicted, the merged_info portion of a
* conflict_info will later be filled with whatever version of
* the file should be placed in the working directory (e.g. an
* as-merged-as-possible variation that contains conflict markers).
*/
struct strmap paths;
/*
* conflicted: a subset of keys->values from "paths"
*
* conflicted is basically an optimization between process_entries()
* and record_conflicted_index_entries(); the latter could loop over
* ALL the entries in paths AGAIN and look for the ones that are
* still conflicted, but since process_entries() has to loop over
* all of them, it saves the ones it couldn't resolve in this strmap
* so that record_conflicted_index_entries() can iterate just the
* relevant entries.
*/
struct strmap conflicted;
/*
* pool: memory pool for fast allocation/deallocation
*
* We allocate room for lots of filenames and auxiliary data
* structures in merge_options_internal, and it tends to all be
* freed together too. Using a memory pool for these provides a
* nice speedup.
*/
struct mem_pool pool;
/*
* conflicts: logical conflicts and messages stored by _primary_ path
*
* This is a map of pathnames (a subset of the keys in "paths" above)
* to struct string_list, with each item's `util` containing a
* `struct logical_conflict_info`. Note, though, that for each path,
* it only stores the logical conflicts for which that path is the
* primary path; the path might be part of additional conflicts.
*/
struct strmap conflicts;
/*
* renames: various data relating to rename detection
*/
struct rename_info renames;
/*
* attr_index: hacky minimal index used for renormalization
*
* renormalization code _requires_ an index, though it only needs to
* find a .gitattributes file within the index. So, when
* renormalization is important, we create a special index with just
* that one file.
*/
struct index_state attr_index;
/*
* current_dir_name, toplevel_dir: temporary vars
*
* These are used in collect_merge_info_callback(), and will set the
* various merged_info.directory_name for the various paths we get;
* see documentation for that variable and the requirements placed on
* that field.
*/
const char *current_dir_name;
const char *toplevel_dir;
/* call_depth: recursion level counter for merging merge bases */
int call_depth;
/* field that holds submodule conflict information */
struct string_list conflicted_submodules;
};
struct conflicted_submodule_item {
char *abbrev;
int flag;
};
static void conflicted_submodule_item_free(void *util, const char *str UNUSED)
{
struct conflicted_submodule_item *item = util;
free(item->abbrev);
free(item);
}
struct version_info {
struct object_id oid;
unsigned short mode;
};
struct merged_info {
/* if is_null, ignore result. otherwise result has oid & mode */
struct version_info result;
unsigned is_null:1;
/*
* clean: whether the path in question is cleanly merged.
*
* see conflict_info.merged for more details.
*/
unsigned clean:1;
/*
* basename_offset: offset of basename of path.
*
* perf optimization to avoid recomputing offset of final '/'
* character in pathname (0 if no '/' in pathname).
*/
size_t basename_offset;
/*
* directory_name: containing directory name.
*
* Note that we assume directory_name is constructed such that
* strcmp(dir1_name, dir2_name) == 0 iff dir1_name == dir2_name,
* i.e. string equality is equivalent to pointer equality. For this
* to hold, we have to be careful setting directory_name.
*/
const char *directory_name;
};
struct conflict_info {
/*
* merged: the version of the path that will be written to working tree
*
* WARNING: It is critical to check merged.clean and ensure it is 0
* before reading any conflict_info fields outside of merged.
* Allocated merge_info structs will always have clean set to 1.
* Allocated conflict_info structs will have merged.clean set to 0
* initially. The merged.clean field is how we know if it is safe
* to access other parts of conflict_info besides merged; if a
* conflict_info's merged.clean is changed to 1, the rest of the
* algorithm is not allowed to look at anything outside of the
* merged member anymore.
*/
struct merged_info merged;
/* oids & modes from each of the three trees for this path */
struct version_info stages[3];
/* pathnames for each stage; may differ due to rename detection */
const char *pathnames[3];
/* Whether this path is/was involved in a directory/file conflict */
unsigned df_conflict:1;
/*
* Whether this path is/was involved in a non-content conflict other
* than a directory/file conflict (e.g. rename/rename, rename/delete,
* file location based on possible directory rename).
*/
unsigned path_conflict:1;
/*
* For filemask and dirmask, the ith bit corresponds to whether the
* ith entry is a file (filemask) or a directory (dirmask). Thus,
* filemask & dirmask is always zero, and filemask | dirmask is at
* most 7 but can be less when a path does not appear as either a
* file or a directory on at least one side of history.
*
* Note that these masks are related to enum merge_side, as the ith
* entry corresponds to side i.
*
* These values come from a traverse_trees() call; more info may be
* found looking at tree-walk.h's struct traverse_info,
* particularly the documentation above the "fn" member (note that
* filemask = mask & ~dirmask from that documentation).
*/
unsigned filemask:3;
unsigned dirmask:3;
/*
* Optimization to track which stages match, to avoid the need to
* recompute it in multiple steps. Either 0 or at least 2 bits are
* set; if at least 2 bits are set, their corresponding stages match.
*/
unsigned match_mask:3;
};
enum conflict_and_info_types {
/* "Simple" conflicts and informational messages */
INFO_AUTO_MERGING = 0,
CONFLICT_CONTENTS, /* text file that failed to merge */
CONFLICT_BINARY,
CONFLICT_FILE_DIRECTORY,
CONFLICT_DISTINCT_MODES,
CONFLICT_MODIFY_DELETE,
/* Regular rename */
CONFLICT_RENAME_RENAME, /* same file renamed differently */
CONFLICT_RENAME_COLLIDES, /* rename/add or two files renamed to 1 */
CONFLICT_RENAME_DELETE,
/* Basic directory rename */
CONFLICT_DIR_RENAME_SUGGESTED,
INFO_DIR_RENAME_APPLIED,
/* Special directory rename cases */
INFO_DIR_RENAME_SKIPPED_DUE_TO_RERENAME,
CONFLICT_DIR_RENAME_FILE_IN_WAY,
CONFLICT_DIR_RENAME_COLLISION,
CONFLICT_DIR_RENAME_SPLIT,
/* Basic submodule */
INFO_SUBMODULE_FAST_FORWARDING,
CONFLICT_SUBMODULE_FAILED_TO_MERGE,
/* Special submodule cases broken out from FAILED_TO_MERGE */
CONFLICT_SUBMODULE_FAILED_TO_MERGE_BUT_POSSIBLE_RESOLUTION,
CONFLICT_SUBMODULE_NOT_INITIALIZED,
CONFLICT_SUBMODULE_HISTORY_NOT_AVAILABLE,
CONFLICT_SUBMODULE_MAY_HAVE_REWINDS,
CONFLICT_SUBMODULE_NULL_MERGE_BASE,
/* Keep this entry _last_ in the list */
NB_CONFLICT_TYPES,
};
/*
* Short description of conflict type, relied upon by external tools.
*
* We can add more entries, but DO NOT change any of these strings. Also,
* Order MUST match conflict_info_and_types.
*/
static const char *type_short_descriptions[] = {
/*** "Simple" conflicts and informational messages ***/
[INFO_AUTO_MERGING] = "Auto-merging",
[CONFLICT_CONTENTS] = "CONFLICT (contents)",
[CONFLICT_BINARY] = "CONFLICT (binary)",
[CONFLICT_FILE_DIRECTORY] = "CONFLICT (file/directory)",
[CONFLICT_DISTINCT_MODES] = "CONFLICT (distinct modes)",
[CONFLICT_MODIFY_DELETE] = "CONFLICT (modify/delete)",
/*** Regular rename ***/
[CONFLICT_RENAME_RENAME] = "CONFLICT (rename/rename)",
[CONFLICT_RENAME_COLLIDES] = "CONFLICT (rename involved in collision)",
[CONFLICT_RENAME_DELETE] = "CONFLICT (rename/delete)",
/*** Basic directory rename ***/
[CONFLICT_DIR_RENAME_SUGGESTED] =
"CONFLICT (directory rename suggested)",
[INFO_DIR_RENAME_APPLIED] = "Path updated due to directory rename",
/*** Special directory rename cases ***/
[INFO_DIR_RENAME_SKIPPED_DUE_TO_RERENAME] =
"Directory rename skipped since directory was renamed on both sides",
[CONFLICT_DIR_RENAME_FILE_IN_WAY] =
"CONFLICT (file in way of directory rename)",
[CONFLICT_DIR_RENAME_COLLISION] = "CONFLICT(directory rename collision)",
[CONFLICT_DIR_RENAME_SPLIT] = "CONFLICT(directory rename unclear split)",
/*** Basic submodule ***/
[INFO_SUBMODULE_FAST_FORWARDING] = "Fast forwarding submodule",
[CONFLICT_SUBMODULE_FAILED_TO_MERGE] = "CONFLICT (submodule)",
/*** Special submodule cases broken out from FAILED_TO_MERGE ***/
[CONFLICT_SUBMODULE_FAILED_TO_MERGE_BUT_POSSIBLE_RESOLUTION] =
"CONFLICT (submodule with possible resolution)",
[CONFLICT_SUBMODULE_NOT_INITIALIZED] =
"CONFLICT (submodule not initialized)",
[CONFLICT_SUBMODULE_HISTORY_NOT_AVAILABLE] =
"CONFLICT (submodule history not available)",
[CONFLICT_SUBMODULE_MAY_HAVE_REWINDS] =
"CONFLICT (submodule may have rewinds)",
[CONFLICT_SUBMODULE_NULL_MERGE_BASE] =
"CONFLICT (submodule lacks merge base)"
};
struct logical_conflict_info {
enum conflict_and_info_types type;
struct strvec paths;
};
/*** Function Grouping: various utility functions ***/
/*
* For the next three macros, see warning for conflict_info.merged.
*
* In each of the below, mi is a struct merged_info*, and ci was defined
* as a struct conflict_info* (but we need to verify ci isn't actually
* pointed at a struct merged_info*).
*
* INITIALIZE_CI: Assign ci to mi but only if it's safe; set to NULL otherwise.
* VERIFY_CI: Ensure that something we assigned to a conflict_info* is one.
* ASSIGN_AND_VERIFY_CI: Similar to VERIFY_CI but do assignment first.
*/
#define INITIALIZE_CI(ci, mi) do { \
(ci) = (!(mi) || (mi)->clean) ? NULL : (struct conflict_info *)(mi); \
} while (0)
#define VERIFY_CI(ci) assert(ci && !ci->merged.clean);
#define ASSIGN_AND_VERIFY_CI(ci, mi) do { \
(ci) = (struct conflict_info *)(mi); \
assert((ci) && !(mi)->clean); \
} while (0)
static void free_strmap_strings(struct strmap *map)
{
struct hashmap_iter iter;
struct strmap_entry *entry;
strmap_for_each_entry(map, &iter, entry) {
free((char*)entry->key);
}
}
static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
int reinitialize)
{
struct rename_info *renames = &opti->renames;
int i;
void (*strmap_clear_func)(struct strmap *, int) =
reinitialize ? strmap_partial_clear : strmap_clear;
void (*strintmap_clear_func)(struct strintmap *) =
reinitialize ? strintmap_partial_clear : strintmap_clear;
void (*strset_clear_func)(struct strset *) =
reinitialize ? strset_partial_clear : strset_clear;
strmap_clear_func(&opti->paths, 0);
/*
* All keys and values in opti->conflicted are a subset of those in
* opti->paths. We don't want to deallocate anything twice, so we
* don't free the keys and we pass 0 for free_values.
*/
strmap_clear_func(&opti->conflicted, 0);
if (opti->attr_index.cache_nr) /* true iff opt->renormalize */
discard_index(&opti->attr_index);
/* Free memory used by various renames maps */
for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) {
strintmap_clear_func(&renames->dirs_removed[i]);
strmap_clear_func(&renames->dir_renames[i], 0);
strintmap_clear_func(&renames->relevant_sources[i]);
if (!reinitialize)
assert(renames->cached_pairs_valid_side == 0);
if (i != renames->cached_pairs_valid_side &&
-1 != renames->cached_pairs_valid_side) {
strset_clear_func(&renames->cached_target_names[i]);
strmap_clear_func(&renames->cached_pairs[i], 1);
strset_clear_func(&renames->cached_irrelevant[i]);
partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
if (!reinitialize)
strmap_clear(&renames->dir_rename_count[i], 1);
}
}
for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) {
strintmap_clear_func(&renames->deferred[i].possible_trivial_merges);
strset_clear_func(&renames->deferred[i].target_dirs);
renames->deferred[i].trivial_merges_okay = 1; /* 1 == maybe */
}
renames->cached_pairs_valid_side = 0;
renames->dir_rename_mask = 0;
if (!reinitialize) {
struct hashmap_iter iter;
struct strmap_entry *e;
/* Release and free each strbuf found in output */
strmap_for_each_entry(&opti->conflicts, &iter, e) {
struct string_list *list = e->value;
for (int i = 0; i < list->nr; i++) {
struct logical_conflict_info *info =
list->items[i].util;
strvec_clear(&info->paths);
}
/*
* While strictly speaking we don't need to
* free(conflicts) here because we could pass
* free_values=1 when calling strmap_clear() on
* opti->conflicts, that would require strmap_clear
* to do another strmap_for_each_entry() loop, so we
* just free it while we're iterating anyway.
*/
string_list_clear(list, 1);
free(list);
}
strmap_clear(&opti->conflicts, 0);
}
mem_pool_discard(&opti->pool, 0);
string_list_clear_func(&opti->conflicted_submodules,
conflicted_submodule_item_free);
/* Clean out callback_data as well. */
FREE_AND_NULL(renames->callback_data);
renames->callback_data_nr = renames->callback_data_alloc = 0;
}
__attribute__((format (printf, 2, 3)))
static int err(struct merge_options *opt, const char *err, ...)
{
va_list params;
struct strbuf sb = STRBUF_INIT;
strbuf_addstr(&sb, "error: ");
va_start(params, err);
strbuf_vaddf(&sb, err, params);
va_end(params);
error("%s", sb.buf);
strbuf_release(&sb);
return -1;
}
static void format_commit(struct strbuf *sb,
int indent,
struct repository *repo,
struct commit *commit)
{
struct merge_remote_desc *desc;
struct pretty_print_context ctx = {0};
ctx.abbrev = DEFAULT_ABBREV;
strbuf_addchars(sb, ' ', indent);
desc = merge_remote_util(commit);
if (desc) {
strbuf_addf(sb, "virtual %s\n", desc->name);
return;
}
repo_format_commit_message(repo, commit, "%h %s", sb, &ctx);
strbuf_addch(sb, '\n');
}
__attribute__((format (printf, 8, 9)))
static void path_msg(struct merge_options *opt,
enum conflict_and_info_types type,
int omittable_hint, /* skippable under --remerge-diff */
const char *primary_path,
const char *other_path_1, /* may be NULL */
const char *other_path_2, /* may be NULL */
struct string_list *other_paths, /* may be NULL */
const char *fmt, ...)
{
va_list ap;
struct string_list *path_conflicts;
struct logical_conflict_info *info;
struct strbuf buf = STRBUF_INIT;
struct strbuf *dest;
struct strbuf tmp = STRBUF_INIT;
/* Sanity checks */
assert(omittable_hint ==
!starts_with(type_short_descriptions[type], "CONFLICT") ||
type == CONFLICT_DIR_RENAME_SUGGESTED);
if (opt->record_conflict_msgs_as_headers && omittable_hint)
return; /* Do not record mere hints in headers */
if (opt->priv->call_depth && opt->verbosity < 5)
return; /* Ignore messages from inner merges */
/* Ensure path_conflicts (ptr to array of logical_conflict) allocated */
path_conflicts = strmap_get(&opt->priv->conflicts, primary_path);
if (!path_conflicts) {
path_conflicts = xmalloc(sizeof(*path_conflicts));
string_list_init_dup(path_conflicts);
strmap_put(&opt->priv->conflicts, primary_path, path_conflicts);
}
/* Add a logical_conflict at the end to store info from this call */
info = xcalloc(1, sizeof(*info));
info->type = type;
strvec_init(&info->paths);
/* Handle the list of paths */
strvec_push(&info->paths, primary_path);
if (other_path_1)
strvec_push(&info->paths, other_path_1);
if (other_path_2)
strvec_push(&info->paths, other_path_2);
if (other_paths)
for (int i = 0; i < other_paths->nr; i++)
strvec_push(&info->paths, other_paths->items[i].string);
/* Handle message and its format, in normal case */
dest = (opt->record_conflict_msgs_as_headers ? &tmp : &buf);
va_start(ap, fmt);
if (opt->priv->call_depth) {
strbuf_addchars(dest, ' ', 2);
strbuf_addstr(dest, "From inner merge:");
strbuf_addchars(dest, ' ', opt->priv->call_depth * 2);
}
strbuf_vaddf(dest, fmt, ap);
va_end(ap);
/* Handle specialized formatting of message under --remerge-diff */
if (opt->record_conflict_msgs_as_headers) {
int i_sb = 0, i_tmp = 0;
/* Start with the specified prefix */
if (opt->msg_header_prefix)
strbuf_addf(&buf, "%s ", opt->msg_header_prefix);
/* Copy tmp to sb, adding spaces after newlines */
strbuf_grow(&buf, buf.len + 2*tmp.len); /* more than sufficient */
for (; i_tmp < tmp.len; i_tmp++, i_sb++) {
/* Copy next character from tmp to sb */
buf.buf[buf.len + i_sb] = tmp.buf[i_tmp];
/* If we copied a newline, add a space */
if (tmp.buf[i_tmp] == '\n')
buf.buf[++i_sb] = ' ';
}
/* Update length and ensure it's NUL-terminated */
buf.len += i_sb;
buf.buf[buf.len] = '\0';
strbuf_release(&tmp);
}
string_list_append_nodup(path_conflicts, strbuf_detach(&buf, NULL))
->util = info;
}
static struct diff_filespec *pool_alloc_filespec(struct mem_pool *pool,
const char *path)
{
/* Similar to alloc_filespec(), but allocate from pool and reuse path */
struct diff_filespec *spec;
spec = mem_pool_calloc(pool, 1, sizeof(*spec));
spec->path = (char*)path; /* spec won't modify it */
spec->count = 1;
spec->is_binary = -1;
return spec;
}
static struct diff_filepair *pool_diff_queue(struct mem_pool *pool,
struct diff_queue_struct *queue,
struct diff_filespec *one,
struct diff_filespec *two)
{
/* Same code as diff_queue(), except allocate from pool */
struct diff_filepair *dp;
dp = mem_pool_calloc(pool, 1, sizeof(*dp));
dp->one = one;
dp->two = two;
if (queue)
diff_q(queue, dp);
return dp;
}
/* add a string to a strbuf, but converting "/" to "_" */
static void add_flattened_path(struct strbuf *out, const char *s)
{
size_t i = out->len;
strbuf_addstr(out, s);
for (; i < out->len; i++)
if (out->buf[i] == '/')
out->buf[i] = '_';
}
static char *unique_path(struct merge_options *opt,
const char *path,
const char *branch)
{
char *ret = NULL;
struct strbuf newpath = STRBUF_INIT;
int suffix = 0;
size_t base_len;
struct strmap *existing_paths = &opt->priv->paths;
strbuf_addf(&newpath, "%s~", path);
add_flattened_path(&newpath, branch);
base_len = newpath.len;
while (strmap_contains(existing_paths, newpath.buf)) {
strbuf_setlen(&newpath, base_len);
strbuf_addf(&newpath, "_%d", suffix++);
}
/* Track the new path in our memory pool */
ret = mem_pool_alloc(&opt->priv->pool, newpath.len + 1);
memcpy(ret, newpath.buf, newpath.len + 1);
strbuf_release(&newpath);
return ret;
}
/*** Function Grouping: functions related to collect_merge_info() ***/
static int traverse_trees_wrapper_callback(int n,
unsigned long mask,
unsigned long dirmask,
struct name_entry *names,
struct traverse_info *info)
{
struct merge_options *opt = info->data;
struct rename_info *renames = &opt->priv->renames;
unsigned filemask = mask & ~dirmask;
assert(n==3);
if (!renames->callback_data_traverse_path)
renames->callback_data_traverse_path = xstrdup(info->traverse_path);
if (filemask && filemask == renames->dir_rename_mask)
renames->dir_rename_mask = 0x07;
ALLOC_GROW(renames->callback_data, renames->callback_data_nr + 1,
renames->callback_data_alloc);
renames->callback_data[renames->callback_data_nr].mask = mask;
renames->callback_data[renames->callback_data_nr].dirmask = dirmask;
COPY_ARRAY(renames->callback_data[renames->callback_data_nr].names,
names, 3);
renames->callback_data_nr++;
return mask;
}
/*
* Much like traverse_trees(), BUT:
* - read all the tree entries FIRST, saving them
* - note that the above step provides an opportunity to compute necessary
* additional details before the "real" traversal
* - loop through the saved entries and call the original callback on them
*/
static int traverse_trees_wrapper(struct index_state *istate,
int n,
struct tree_desc *t,
struct traverse_info *info)
{
int ret, i, old_offset;
traverse_callback_t old_fn;
char *old_callback_data_traverse_path;
struct merge_options *opt = info->data;
struct rename_info *renames = &opt->priv->renames;
assert(renames->dir_rename_mask == 2 || renames->dir_rename_mask == 4);
old_callback_data_traverse_path = renames->callback_data_traverse_path;
old_fn = info->fn;
old_offset = renames->callback_data_nr;
renames->callback_data_traverse_path = NULL;
info->fn = traverse_trees_wrapper_callback;
ret = traverse_trees(istate, n, t, info);
if (ret < 0)
return ret;
info->traverse_path = renames->callback_data_traverse_path;
info->fn = old_fn;
for (i = old_offset; i < renames->callback_data_nr; ++i) {
info->fn(n,
renames->callback_data[i].mask,
renames->callback_data[i].dirmask,
renames->callback_data[i].names,
info);
}
renames->callback_data_nr = old_offset;
free(renames->callback_data_traverse_path);
renames->callback_data_traverse_path = old_callback_data_traverse_path;
info->traverse_path = NULL;
return 0;
}
static void setup_path_info(struct merge_options *opt,
struct string_list_item *result,
const char *current_dir_name,
int current_dir_name_len,
char *fullpath, /* we'll take over ownership */
struct name_entry *names,
struct name_entry *merged_version,
unsigned is_null, /* boolean */
unsigned df_conflict, /* boolean */
unsigned filemask,
unsigned dirmask,
int resolved /* boolean */)
{
/* result->util is void*, so mi is a convenience typed variable */
struct merged_info *mi;
assert(!is_null || resolved);
assert(!df_conflict || !resolved); /* df_conflict implies !resolved */
assert(resolved == (merged_version != NULL));
mi = mem_pool_calloc(&opt->priv->pool, 1,
resolved ? sizeof(struct merged_info) :
sizeof(struct conflict_info));
mi->directory_name = current_dir_name;
mi->basename_offset = current_dir_name_len;
mi->clean = !!resolved;
if (resolved) {
mi->result.mode = merged_version->mode;
oidcpy(&mi->result.oid, &merged_version->oid);
mi->is_null = !!is_null;
} else {
int i;
struct conflict_info *ci;
ASSIGN_AND_VERIFY_CI(ci, mi);
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
ci->pathnames[i] = fullpath;
ci->stages[i].mode = names[i].mode;
oidcpy(&ci->stages[i].oid, &names[i].oid);
}
ci->filemask = filemask;
ci->dirmask = dirmask;
ci->df_conflict = !!df_conflict;
if (dirmask)
/*
* Assume is_null for now, but if we have entries
* under the directory then when it is complete in
* write_completed_directory() it'll update this.
* Also, for D/F conflicts, we have to handle the
* directory first, then clear this bit and process
* the file to see how it is handled -- that occurs
* near the top of process_entry().
*/
mi->is_null = 1;
}
strmap_put(&opt->priv->paths, fullpath, mi);
result->string = fullpath;
result->util = mi;
}
static void add_pair(struct merge_options *opt,
struct name_entry *names,
const char *pathname,
unsigned side,
unsigned is_add /* if false, is_delete */,
unsigned match_mask,
unsigned dir_rename_mask)
{
struct diff_filespec *one, *two;
struct rename_info *renames = &opt->priv->renames;
int names_idx = is_add ? side : 0;
if (is_add) {
assert(match_mask == 0 || match_mask == 6);
if (strset_contains(&renames->cached_target_names[side],
pathname))
return;
} else {
unsigned content_relevant = (match_mask == 0);
unsigned location_relevant = (dir_rename_mask == 0x07);
assert(match_mask == 0 || match_mask == 3 || match_mask == 5);
/*
* If pathname is found in cached_irrelevant[side] due to
* previous pick but for this commit content is relevant,
* then we need to remove it from cached_irrelevant.
*/
if (content_relevant)
/* strset_remove is no-op if strset doesn't have key */
strset_remove(&renames->cached_irrelevant[side],
pathname);
/*
* We do not need to re-detect renames for paths that we already
* know the pairing, i.e. for cached_pairs (or
* cached_irrelevant). However, handle_deferred_entries() needs
* to loop over the union of keys from relevant_sources[side] and
* cached_pairs[side], so for simplicity we set relevant_sources
* for all the cached_pairs too and then strip them back out in
* prune_cached_from_relevant() at the beginning of
* detect_regular_renames().
*/
if (content_relevant || location_relevant) {
/* content_relevant trumps location_relevant */
strintmap_set(&renames->relevant_sources[side], pathname,
content_relevant ? RELEVANT_CONTENT : RELEVANT_LOCATION);
}
/*
* Avoid creating pair if we've already cached rename results.
* Note that we do this after setting relevant_sources[side]
* as noted in the comment above.
*/
if (strmap_contains(&renames->cached_pairs[side], pathname) ||
strset_contains(&renames->cached_irrelevant[side], pathname))
return;
}
one = pool_alloc_filespec(&opt->priv->pool, pathname);
two = pool_alloc_filespec(&opt->priv->pool, pathname);
fill_filespec(is_add ? two : one,
&names[names_idx].oid, 1, names[names_idx].mode);
pool_diff_queue(&opt->priv->pool, &renames->pairs[side], one, two);
}
static void collect_rename_info(struct merge_options *opt,
struct name_entry *names,
const char *dirname,
const char *fullname,
unsigned filemask,
unsigned dirmask,
unsigned match_mask)
{
struct rename_info *renames = &opt->priv->renames;
unsigned side;
/*
* Update dir_rename_mask (determines ignore-rename-source validity)
*
* dir_rename_mask helps us keep track of when directory rename
* detection may be relevant. Basically, whenver a directory is
* removed on one side of history, and a file is added to that
* directory on the other side of history, directory rename
* detection is relevant (meaning we have to detect renames for all
* files within that directory to deduce where the directory
* moved). Also, whenever a directory needs directory rename
* detection, due to the "majority rules" choice for where to move
* it (see t6423 testcase 1f), we also need to detect renames for
* all files within subdirectories of that directory as well.
*
* Here we haven't looked at files within the directory yet, we are
* just looking at the directory itself. So, if we aren't yet in
* a case where a parent directory needed directory rename detection
* (i.e. dir_rename_mask != 0x07), and if the directory was removed
* on one side of history, record the mask of the other side of
* history in dir_rename_mask.
*/
if (renames->dir_rename_mask != 0x07 &&
(dirmask == 3 || dirmask == 5)) {
/* simple sanity check */
assert(renames->dir_rename_mask == 0 ||
renames->dir_rename_mask == (dirmask & ~1));
/* update dir_rename_mask; have it record mask of new side */
renames->dir_rename_mask = (dirmask & ~1);
}
/* Update dirs_removed, as needed */
if (dirmask == 1 || dirmask == 3 || dirmask == 5) {
/* absent_mask = 0x07 - dirmask; sides = absent_mask/2 */
unsigned sides = (0x07 - dirmask)/2;
unsigned relevance = (renames->dir_rename_mask == 0x07) ?
RELEVANT_FOR_ANCESTOR : NOT_RELEVANT;
/*
* Record relevance of this directory. However, note that
* when collect_merge_info_callback() recurses into this
* directory and calls collect_rename_info() on paths
* within that directory, if we find a path that was added
* to this directory on the other side of history, we will
* upgrade this value to RELEVANT_FOR_SELF; see below.
*/
if (sides & 1)
strintmap_set(&renames->dirs_removed[1], fullname,
relevance);
if (sides & 2)
strintmap_set(&renames->dirs_removed[2], fullname,
relevance);
}
/*
* Here's the block that potentially upgrades to RELEVANT_FOR_SELF.
* When we run across a file added to a directory. In such a case,
* find the directory of the file and upgrade its relevance.
*/
if (renames->dir_rename_mask == 0x07 &&
(filemask == 2 || filemask == 4)) {
/*
* Need directory rename for parent directory on other side
* of history from added file. Thus
* side = (~filemask & 0x06) >> 1
* or
* side = 3 - (filemask/2).
*/
unsigned side = 3 - (filemask >> 1);
strintmap_set(&renames->dirs_removed[side], dirname,
RELEVANT_FOR_SELF);
}
if (filemask == 0 || filemask == 7)
return;
for (side = MERGE_SIDE1; side <= MERGE_SIDE2; ++side) {
unsigned side_mask = (1 << side);
/* Check for deletion on side */
if ((filemask & 1) && !(filemask & side_mask))
add_pair(opt, names, fullname, side, 0 /* delete */,
match_mask & filemask,
renames->dir_rename_mask);
/* Check for addition on side */
if (!(filemask & 1) && (filemask & side_mask))
add_pair(opt, names, fullname, side, 1 /* add */,
match_mask & filemask,
renames->dir_rename_mask);
}
}
static int collect_merge_info_callback(int n,
unsigned long mask,
unsigned long dirmask,
struct name_entry *names,
struct traverse_info *info)
{
/*
* n is 3. Always.
* common ancestor (mbase) has mask 1, and stored in index 0 of names
* head of side 1 (side1) has mask 2, and stored in index 1 of names
* head of side 2 (side2) has mask 4, and stored in index 2 of names
*/
struct merge_options *opt = info->data;
struct merge_options_internal *opti = opt->priv;
struct rename_info *renames = &opt->priv->renames;
struct string_list_item pi; /* Path Info */
struct conflict_info *ci; /* typed alias to pi.util (which is void*) */
struct name_entry *p;
size_t len;
char *fullpath;
const char *dirname = opti->current_dir_name;
unsigned prev_dir_rename_mask = renames->dir_rename_mask;
unsigned filemask = mask & ~dirmask;
unsigned match_mask = 0; /* will be updated below */
unsigned mbase_null = !(mask & 1);
unsigned side1_null = !(mask & 2);
unsigned side2_null = !(mask & 4);
unsigned side1_matches_mbase = (!side1_null && !mbase_null &&
names[0].mode == names[1].mode &&
oideq(&names[0].oid, &names[1].oid));
unsigned side2_matches_mbase = (!side2_null && !mbase_null &&
names[0].mode == names[2].mode &&
oideq(&names[0].oid, &names[2].oid));
unsigned sides_match = (!side1_null && !side2_null &&
names[1].mode == names[2].mode &&
oideq(&names[1].oid, &names[2].oid));
/*
* Note: When a path is a file on one side of history and a directory
* in another, we have a directory/file conflict. In such cases, if
* the conflict doesn't resolve from renames and deletions, then we
* always leave directories where they are and move files out of the
* way. Thus, while struct conflict_info has a df_conflict field to
* track such conflicts, we ignore that field for any directories at
* a path and only pay attention to it for files at the given path.
* The fact that we leave directories were they are also means that
* we do not need to worry about getting additional df_conflict
* information propagated from parent directories down to children
* (unlike, say traverse_trees_recursive() in unpack-trees.c, which
* sets a newinfo.df_conflicts field specifically to propagate it).
*/
unsigned df_conflict = (filemask != 0) && (dirmask != 0);
/* n = 3 is a fundamental assumption. */
if (n != 3)
BUG("Called collect_merge_info_callback wrong");
/*
* A bunch of sanity checks verifying that traverse_trees() calls
* us the way I expect. Could just remove these at some point,
* though maybe they are helpful to future code readers.
*/
assert(mbase_null == is_null_oid(&names[0].oid));
assert(side1_null == is_null_oid(&names[1].oid));
assert(side2_null == is_null_oid(&names[2].oid));
assert(!mbase_null || !side1_null || !side2_null);
assert(mask > 0 && mask < 8);
/* Determine match_mask */
if (side1_matches_mbase)
match_mask = (side2_matches_mbase ? 7 : 3);
else if (side2_matches_mbase)
match_mask = 5;
else if (sides_match)
match_mask = 6;
/*
* Get the name of the relevant filepath, which we'll pass to
* setup_path_info() for tracking.
*/
p = names;
while (!p->mode)
p++;
len = traverse_path_len(info, p->pathlen);
/* +1 in both of the following lines to include the NUL byte */
fullpath = mem_pool_alloc(&opt->priv->pool, len + 1);
make_traverse_path(fullpath, len + 1, info, p->path, p->pathlen);
/*
* If mbase, side1, and side2 all match, we can resolve early. Even
* if these are trees, there will be no renames or anything
* underneath.
*/
if (side1_matches_mbase && side2_matches_mbase) {
/* mbase, side1, & side2 all match; use mbase as resolution */
setup_path_info(opt, &pi, dirname, info->pathlen, fullpath,
names, names+0, mbase_null, 0 /* df_conflict */,
filemask, dirmask, 1 /* resolved */);
return mask;
}
/*
* If the sides match, and all three paths are present and are
* files, then we can take either as the resolution. We can't do
* this with trees, because there may be rename sources from the
* merge_base.
*/
if (sides_match && filemask == 0x07) {
/* use side1 (== side2) version as resolution */
setup_path_info(opt, &pi, dirname, info->pathlen, fullpath,
names, names+1, side1_null, 0,
filemask, dirmask, 1);
return mask;
}
/*
* If side1 matches mbase and all three paths are present and are
* files, then we can use side2 as the resolution. We cannot
* necessarily do so this for trees, because there may be rename
* destinations within side2.
*/
if (side1_matches_mbase && filemask == 0x07) {
/* use side2 version as resolution */
setup_path_info(opt, &pi, dirname, info->pathlen, fullpath,
names, names+2, side2_null, 0,
filemask, dirmask, 1);
return mask;
}
/* Similar to above but swapping sides 1 and 2 */
if (side2_matches_mbase && filemask == 0x07) {
/* use side1 version as resolution */
setup_path_info(opt, &pi, dirname, info->pathlen, fullpath,
names, names+1, side1_null, 0,
filemask, dirmask, 1);
return mask;
}
/*
* Sometimes we can tell that a source path need not be included in
* rename detection -- namely, whenever either
* side1_matches_mbase && side2_null
* or
* side2_matches_mbase && side1_null
* However, we call collect_rename_info() even in those cases,
* because exact renames are cheap and would let us remove both a
* source and destination path. We'll cull the unneeded sources
* later.
*/
collect_rename_info(opt, names, dirname, fullpath,
filemask, dirmask, match_mask);
/*
* None of the special cases above matched, so we have a
* provisional conflict. (Rename detection might allow us to
* unconflict some more cases, but that comes later so all we can
* do now is record the different non-null file hashes.)
*/
setup_path_info(opt, &pi, dirname, info->pathlen, fullpath,
names, NULL, 0, df_conflict, filemask, dirmask, 0);
ci = pi.util;
VERIFY_CI(ci);
ci->match_mask = match_mask;
/* If dirmask, recurse into subdirectories */
if (dirmask) {
struct traverse_info newinfo;
struct tree_desc t[3];
void *buf[3] = {NULL, NULL, NULL};
const char *original_dir_name;
int i, ret, side;
/*
* Check for whether we can avoid recursing due to one side
* matching the merge base. The side that does NOT match is
* the one that might have a rename destination we need.
*/
assert(!side1_matches_mbase || !side2_matches_mbase);
side = side1_matches_mbase ? MERGE_SIDE2 :
side2_matches_mbase ? MERGE_SIDE1 : MERGE_BASE;
if (filemask == 0 && (dirmask == 2 || dirmask == 4)) {
/*
* Also defer recursing into new directories; set up a
* few variables to let us do so.
*/
ci->match_mask = (7 - dirmask);
side = dirmask / 2;
}
if (renames->dir_rename_mask != 0x07 &&
side != MERGE_BASE &&
renames->deferred[side].trivial_merges_okay &&
!strset_contains(&renames->deferred[side].target_dirs,
pi.string)) {
strintmap_set(&renames->deferred[side].possible_trivial_merges,
pi.string, renames->dir_rename_mask);
renames->dir_rename_mask = prev_dir_rename_mask;
return mask;
}
/* We need to recurse */
ci->match_mask &= filemask;
newinfo = *info;
newinfo.prev = info;
newinfo.name = p->path;
newinfo.namelen = p->pathlen;
newinfo.pathlen = st_add3(newinfo.pathlen, p->pathlen, 1);
/*
* If this directory we are about to recurse into cared about
* its parent directory (the current directory) having a D/F
* conflict, then we'd propagate the masks in this way:
* newinfo.df_conflicts |= (mask & ~dirmask);
* But we don't worry about propagating D/F conflicts. (See
* comment near setting of local df_conflict variable near
* the beginning of this function).
*/
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
if (i == 1 && side1_matches_mbase)
t[1] = t[0];
else if (i == 2 && side2_matches_mbase)
t[2] = t[0];
else if (i == 2 && sides_match)
t[2] = t[1];
else {
const struct object_id *oid = NULL;
if (dirmask & 1)
oid = &names[i].oid;
buf[i] = fill_tree_descriptor(opt->repo,
t + i, oid);
}
dirmask >>= 1;
}
original_dir_name = opti->current_dir_name;
opti->current_dir_name = pi.string;
if (renames->dir_rename_mask == 0 ||
renames->dir_rename_mask == 0x07)
ret = traverse_trees(NULL, 3, t, &newinfo);
else
ret = traverse_trees_wrapper(NULL, 3, t, &newinfo);
opti->current_dir_name = original_dir_name;
renames->dir_rename_mask = prev_dir_rename_mask;
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++)
free(buf[i]);
if (ret < 0)
return -1;
}
return mask;
}
static void resolve_trivial_directory_merge(struct conflict_info *ci, int side)
{
VERIFY_CI(ci);
assert((side == 1 && ci->match_mask == 5) ||
(side == 2 && ci->match_mask == 3));
oidcpy(&ci->merged.result.oid, &ci->stages[side].oid);
ci->merged.result.mode = ci->stages[side].mode;
ci->merged.is_null = is_null_oid(&ci->stages[side].oid);
ci->match_mask = 0;
ci->merged.clean = 1; /* (ci->filemask == 0); */
}
static int handle_deferred_entries(struct merge_options *opt,
struct traverse_info *info)
{
struct rename_info *renames = &opt->priv->renames;
struct hashmap_iter iter;
struct strmap_entry *entry;
int side, ret = 0;
int path_count_before, path_count_after = 0;
path_count_before = strmap_get_size(&opt->priv->paths);
for (side = MERGE_SIDE1; side <= MERGE_SIDE2; side++) {
unsigned optimization_okay = 1;
struct strintmap copy;
/* Loop over the set of paths we need to know rename info for */
strset_for_each_entry(&renames->relevant_sources[side],
&iter, entry) {
char *rename_target, *dir, *dir_marker;
struct strmap_entry *e;
/*
* If we don't know delete/rename info for this path,
* then we need to recurse into all trees to get all
* adds to make sure we have it.
*/
if (strset_contains(&renames->cached_irrelevant[side],
entry->key))
continue;
e = strmap_get_entry(&renames->cached_pairs[side],
entry->key);
if (!e) {
optimization_okay = 0;
break;
}
/* If this is a delete, we have enough info already */
rename_target = e->value;
if (!rename_target)
continue;
/* If we already walked the rename target, we're good */
if (strmap_contains(&opt->priv->paths, rename_target))
continue;
/*
* Otherwise, we need to get a list of directories that
* will need to be recursed into to get this
* rename_target.
*/
dir = xstrdup(rename_target);
while ((dir_marker = strrchr(dir, '/'))) {
*dir_marker = '\0';
if (strset_contains(&renames->deferred[side].target_dirs,
dir))
break;
strset_add(&renames->deferred[side].target_dirs,
dir);
}
free(dir);
}
renames->deferred[side].trivial_merges_okay = optimization_okay;
/*
* We need to recurse into any directories in
* possible_trivial_merges[side] found in target_dirs[side].
* But when we recurse, we may need to queue up some of the
* subdirectories for possible_trivial_merges[side]. Since
* we can't safely iterate through a hashmap while also adding
* entries, move the entries into 'copy', iterate over 'copy',
* and then we'll also iterate anything added into
* possible_trivial_merges[side] once this loop is done.
*/
copy = renames->deferred[side].possible_trivial_merges;
strintmap_init_with_options(&renames->deferred[side].possible_trivial_merges,
0,
&opt->priv->pool,
0);
strintmap_for_each_entry(&copy, &iter, entry) {
const char *path = entry->key;
unsigned dir_rename_mask = (intptr_t)entry->value;
struct conflict_info *ci;
unsigned dirmask;
struct tree_desc t[3];
void *buf[3] = {NULL,};
int i;
ci = strmap_get(&opt->priv->paths, path);
VERIFY_CI(ci);
dirmask = ci->dirmask;
if (optimization_okay &&
!strset_contains(&renames->deferred[side].target_dirs,
path)) {
resolve_trivial_directory_merge(ci, side);
continue;
}
info->name = path;
info->namelen = strlen(path);
info->pathlen = info->namelen + 1;
for (i = 0; i < 3; i++, dirmask >>= 1) {
if (i == 1 && ci->match_mask == 3)
t[1] = t[0];
else if (i == 2 && ci->match_mask == 5)
t[2] = t[0];
else if (i == 2 && ci->match_mask == 6)
t[2] = t[1];
else {
const struct object_id *oid = NULL;
if (dirmask & 1)
oid = &ci->stages[i].oid;
buf[i] = fill_tree_descriptor(opt->repo,
t+i, oid);
}
}
ci->match_mask &= ci->filemask;
opt->priv->current_dir_name = path;
renames->dir_rename_mask = dir_rename_mask;
if (renames->dir_rename_mask == 0 ||
renames->dir_rename_mask == 0x07)
ret = traverse_trees(NULL, 3, t, info);
else
ret = traverse_trees_wrapper(NULL, 3, t, info);
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++)
free(buf[i]);
if (ret < 0)
return ret;
}
strintmap_clear(&copy);
strintmap_for_each_entry(&renames->deferred[side].possible_trivial_merges,
&iter, entry) {
const char *path = entry->key;
struct conflict_info *ci;
ci = strmap_get(&opt->priv->paths, path);
VERIFY_CI(ci);
assert(renames->deferred[side].trivial_merges_okay &&
!strset_contains(&renames->deferred[side].target_dirs,
path));
resolve_trivial_directory_merge(ci, side);
}
if (!optimization_okay || path_count_after)
path_count_after = strmap_get_size(&opt->priv->paths);
}
if (path_count_after) {
/*
* The choice of wanted_factor here does not affect
* correctness, only performance. When the
* path_count_after / path_count_before
* ratio is high, redoing after renames is a big
* performance boost. I suspect that redoing is a wash
* somewhere near a value of 2, and below that redoing will
* slow things down. I applied a fudge factor and picked
* 3; see the commit message when this was introduced for
* back of the envelope calculations for this ratio.
*/
const int wanted_factor = 3;
/* We should only redo collect_merge_info one time */
assert(renames->redo_after_renames == 0);
if (path_count_after / path_count_before >= wanted_factor) {
renames->redo_after_renames = 1;
renames->cached_pairs_valid_side = -1;
}
} else if (renames->redo_after_renames == 2)
renames->redo_after_renames = 0;
return ret;
}
static int collect_merge_info(struct merge_options *opt,
struct tree *merge_base,
struct tree *side1,
struct tree *side2)
{
int ret;
struct tree_desc t[3];
struct traverse_info info;
opt->priv->toplevel_dir = "";
opt->priv->current_dir_name = opt->priv->toplevel_dir;
setup_traverse_info(&info, opt->priv->toplevel_dir);
info.fn = collect_merge_info_callback;
info.data = opt;
info.show_all_errors = 1;
parse_tree(merge_base);
parse_tree(side1);
parse_tree(side2);
init_tree_desc(t + 0, merge_base->buffer, merge_base->size);
init_tree_desc(t + 1, side1->buffer, side1->size);
init_tree_desc(t + 2, side2->buffer, side2->size);
trace2_region_enter("merge", "traverse_trees", opt->repo);
ret = traverse_trees(NULL, 3, t, &info);
if (ret == 0)
ret = handle_deferred_entries(opt, &info);
trace2_region_leave("merge", "traverse_trees", opt->repo);
return ret;
}
/*** Function Grouping: functions related to threeway content merges ***/
static int find_first_merges(struct repository *repo,
const char *path,
struct commit *a,
struct commit *b,
struct object_array *result)
{
int i, j;
struct object_array merges = OBJECT_ARRAY_INIT;
struct commit *commit;
int contains_another;
char merged_revision[GIT_MAX_HEXSZ + 2];
const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
"--all", merged_revision, NULL };
struct rev_info revs;
struct setup_revision_opt rev_opts;
memset(result, 0, sizeof(struct object_array));
memset(&rev_opts, 0, sizeof(rev_opts));
/* get all revisions that merge commit a */
xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
oid_to_hex(&a->object.oid));
repo_init_revisions(repo, &revs, NULL);
/* FIXME: can't handle linked worktrees in submodules yet */
revs.single_worktree = path != NULL;
setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
/* save all revisions from the above list that contain b */
if (prepare_revision_walk(&revs))
die("revision walk setup failed");
while ((commit = get_revision(&revs)) != NULL) {
struct object *o = &(commit->object);
if (repo_in_merge_bases(repo, b, commit))
add_object_array(o, NULL, &merges);
}
reset_revision_walk();
/* Now we've got all merges that contain a and b. Prune all
* merges that contain another found merge and save them in
* result.
*/
for (i = 0; i < merges.nr; i++) {
struct commit *m1 = (struct commit *) merges.objects[i].item;
contains_another = 0;
for (j = 0; j < merges.nr; j++) {
struct commit *m2 = (struct commit *) merges.objects[j].item;
if (i != j && repo_in_merge_bases(repo, m2, m1)) {
contains_another = 1;
break;
}
}
if (!contains_another)
add_object_array(merges.objects[i].item, NULL, result);
}
object_array_clear(&merges);
release_revisions(&revs);
return result->nr;
}
static int merge_submodule(struct merge_options *opt,
const char *path,
const struct object_id *o,
const struct object_id *a,
const struct object_id *b,
struct object_id *result)
{
struct repository subrepo;
struct strbuf sb = STRBUF_INIT;
int ret = 0;
struct commit *commit_o, *commit_a, *commit_b;
int parent_count;
struct object_array merges;
int i;
int search = !opt->priv->call_depth;
int sub_not_initialized = 1;
int sub_flag = CONFLICT_SUBMODULE_FAILED_TO_MERGE;
/* store fallback answer in result in case we fail */
oidcpy(result, opt->priv->call_depth ? o : a);
/* we can not handle deletion conflicts */
if (is_null_oid(a) || is_null_oid(b))
BUG("submodule deleted on one side; this should be handled outside of merge_submodule()");
if ((sub_not_initialized = repo_submodule_init(&subrepo,
opt->repo, path, null_oid()))) {
path_msg(opt, CONFLICT_SUBMODULE_NOT_INITIALIZED, 0,
path, NULL, NULL, NULL,
_("Failed to merge submodule %s (not checked out)"),
path);
sub_flag = CONFLICT_SUBMODULE_NOT_INITIALIZED;
goto cleanup;
}
if (is_null_oid(o)) {
path_msg(opt, CONFLICT_SUBMODULE_NULL_MERGE_BASE, 0,
path, NULL, NULL, NULL,
_("Failed to merge submodule %s (no merge base)"),
path);
goto cleanup;
}
if (!(commit_o = lookup_commit_reference(&subrepo, o)) ||
!(commit_a = lookup_commit_reference(&subrepo, a)) ||
!(commit_b = lookup_commit_reference(&subrepo, b))) {
path_msg(opt, CONFLICT_SUBMODULE_HISTORY_NOT_AVAILABLE, 0,
path, NULL, NULL, NULL,
_("Failed to merge submodule %s (commits not present)"),
path);
sub_flag = CONFLICT_SUBMODULE_HISTORY_NOT_AVAILABLE;
goto cleanup;
}
/* check whether both changes are forward */
if (!repo_in_merge_bases(&subrepo, commit_o, commit_a) ||
!repo_in_merge_bases(&subrepo, commit_o, commit_b)) {
path_msg(opt, CONFLICT_SUBMODULE_MAY_HAVE_REWINDS, 0,
path, NULL, NULL, NULL,
_("Failed to merge submodule %s "
"(commits don't follow merge-base)"),
path);
goto cleanup;
}
/* Case #1: a is contained in b or vice versa */
if (repo_in_merge_bases(&subrepo, commit_a, commit_b)) {
oidcpy(result, b);
path_msg(opt, INFO_SUBMODULE_FAST_FORWARDING, 1,
path, NULL, NULL, NULL,
_("Note: Fast-forwarding submodule %s to %s"),
path, oid_to_hex(b));
ret = 1;
goto cleanup;
}
if (repo_in_merge_bases(&subrepo, commit_b, commit_a)) {
oidcpy(result, a);
path_msg(opt, INFO_SUBMODULE_FAST_FORWARDING, 1,
path, NULL, NULL, NULL,
_("Note: Fast-forwarding submodule %s to %s"),
path, oid_to_hex(a));
ret = 1;
goto cleanup;
}
/*
* Case #2: There are one or more merges that contain a and b in
* the submodule. If there is only one, then present it as a
* suggestion to the user, but leave it marked unmerged so the
* user needs to confirm the resolution.
*/
/* Skip the search if makes no sense to the calling context. */
if (!search)
goto cleanup;
/* find commit which merges them */
parent_count = find_first_merges(&subrepo, path, commit_a, commit_b,
&merges);
switch (parent_count) {
case 0:
path_msg(opt, CONFLICT_SUBMODULE_FAILED_TO_MERGE, 0,
path, NULL, NULL, NULL,
_("Failed to merge submodule %s"), path);
break;
case 1:
format_commit(&sb, 4, &subrepo,
(struct commit *)merges.objects[0].item);
path_msg(opt, CONFLICT_SUBMODULE_FAILED_TO_MERGE_BUT_POSSIBLE_RESOLUTION, 0,
path, NULL, NULL, NULL,
_("Failed to merge submodule %s, but a possible merge "
"resolution exists: %s"),
path, sb.buf);
strbuf_release(&sb);
break;
default:
for (i = 0; i < merges.nr; i++)
format_commit(&sb, 4, &subrepo,
(struct commit *)merges.objects[i].item);
path_msg(opt, CONFLICT_SUBMODULE_FAILED_TO_MERGE_BUT_POSSIBLE_RESOLUTION, 0,
path, NULL, NULL, NULL,
_("Failed to merge submodule %s, but multiple "
"possible merges exist:\n%s"), path, sb.buf);
strbuf_release(&sb);
}
object_array_clear(&merges);
cleanup:
if (!opt->priv->call_depth && !ret) {
struct string_list *csub = &opt->priv->conflicted_submodules;
struct conflicted_submodule_item *util;
const char *abbrev;
util = xmalloc(sizeof(*util));
util->flag = sub_flag;
util->abbrev = NULL;
if (!sub_not_initialized) {
abbrev = repo_find_unique_abbrev(&subrepo, b, DEFAULT_ABBREV);
util->abbrev = xstrdup(abbrev);
}
string_list_append(csub, path)->util = util;
}
if (!sub_not_initialized)
repo_clear(&subrepo);
return ret;
}
static void initialize_attr_index(struct merge_options *opt)
{
/*
* The renormalize_buffer() functions require attributes, and
* annoyingly those can only be read from the working tree or from
* an index_state. merge-ort doesn't have an index_state, so we
* generate a fake one containing only attribute information.
*/
struct merged_info *mi;
struct index_state *attr_index = &opt->priv->attr_index;
struct cache_entry *ce;
attr_index->initialized = 1;
if (!opt->renormalize)
return;
mi = strmap_get(&opt->priv->paths, GITATTRIBUTES_FILE);
if (!mi)
return;
if (mi->clean) {
int len = strlen(GITATTRIBUTES_FILE);
ce = make_empty_cache_entry(attr_index, len);
ce->ce_mode = create_ce_mode(mi->result.mode);
ce->ce_flags = create_ce_flags(0);
ce->ce_namelen = len;
oidcpy(&ce->oid, &mi->result.oid);
memcpy(ce->name, GITATTRIBUTES_FILE, len);
add_index_entry(attr_index, ce,
ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
get_stream_filter(attr_index, GITATTRIBUTES_FILE, &ce->oid);
} else {
int stage, len;
struct conflict_info *ci;
ASSIGN_AND_VERIFY_CI(ci, mi);
for (stage = 0; stage < 3; stage++) {
unsigned stage_mask = (1 << stage);
if (!(ci->filemask & stage_mask))
continue;
len = strlen(GITATTRIBUTES_FILE);
ce = make_empty_cache_entry(attr_index, len);
ce->ce_mode = create_ce_mode(ci->stages[stage].mode);
ce->ce_flags = create_ce_flags(stage);
ce->ce_namelen = len;
oidcpy(&ce->oid, &ci->stages[stage].oid);
memcpy(ce->name, GITATTRIBUTES_FILE, len);
add_index_entry(attr_index, ce,
ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
get_stream_filter(attr_index, GITATTRIBUTES_FILE,
&ce->oid);
}
}
}
static int merge_3way(struct merge_options *opt,
const char *path,
const struct object_id *o,
const struct object_id *a,
const struct object_id *b,
const char *pathnames[3],
const int extra_marker_size,
mmbuffer_t *result_buf)
{
mmfile_t orig, src1, src2;
struct ll_merge_options ll_opts = {0};
char *base, *name1, *name2;
enum ll_merge_result merge_status;
if (!opt->priv->attr_index.initialized)
initialize_attr_index(opt);
ll_opts.renormalize = opt->renormalize;
ll_opts.extra_marker_size = extra_marker_size;
ll_opts.xdl_opts = opt->xdl_opts;
if (opt->priv->call_depth) {
ll_opts.virtual_ancestor = 1;
ll_opts.variant = 0;
} else {
switch (opt->recursive_variant) {
case MERGE_VARIANT_OURS:
ll_opts.variant = XDL_MERGE_FAVOR_OURS;
break;
case MERGE_VARIANT_THEIRS:
ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
break;
default:
ll_opts.variant = 0;
break;
}
}
assert(pathnames[0] && pathnames[1] && pathnames[2] && opt->ancestor);
if (pathnames[0] == pathnames[1] && pathnames[1] == pathnames[2]) {
base = mkpathdup("%s", opt->ancestor);
name1 = mkpathdup("%s", opt->branch1);
name2 = mkpathdup("%s", opt->branch2);
} else {
base = mkpathdup("%s:%s", opt->ancestor, pathnames[0]);
name1 = mkpathdup("%s:%s", opt->branch1, pathnames[1]);
name2 = mkpathdup("%s:%s", opt->branch2, pathnames[2]);
}
read_mmblob(&orig, o);
read_mmblob(&src1, a);
read_mmblob(&src2, b);
merge_status = ll_merge(result_buf, path, &orig, base,
&src1, name1, &src2, name2,
&opt->priv->attr_index, &ll_opts);
if (merge_status == LL_MERGE_BINARY_CONFLICT)
path_msg(opt, CONFLICT_BINARY, 0,
path, NULL, NULL, NULL,
"warning: Cannot merge binary files: %s (%s vs. %s)",
path, name1, name2);
free(base);
free(name1);
free(name2);
free(orig.ptr);
free(src1.ptr);
free(src2.ptr);
return merge_status;
}
static int handle_content_merge(struct merge_options *opt,
const char *path,
const struct version_info *o,
const struct version_info *a,
const struct version_info *b,
const char *pathnames[3],
const int extra_marker_size,
struct version_info *result)
{
/*
* path is the target location where we want to put the file, and
* is used to determine any normalization rules in ll_merge.
*
* The normal case is that path and all entries in pathnames are
* identical, though renames can affect which path we got one of
* the three blobs to merge on various sides of history.
*
* extra_marker_size is the amount to extend conflict markers in
* ll_merge; this is neeed if we have content merges of content
* merges, which happens for example with rename/rename(2to1) and
* rename/add conflicts.
*/
unsigned clean = 1;
/*
* handle_content_merge() needs both files to be of the same type, i.e.
* both files OR both submodules OR both symlinks. Conflicting types
* needs to be handled elsewhere.
*/
assert((S_IFMT & a->mode) == (S_IFMT & b->mode));
/* Merge modes */
if (a->mode == b->mode || a->mode == o->mode)
result->mode = b->mode;
else {
/* must be the 100644/100755 case */
assert(S_ISREG(a->mode));
result->mode = a->mode;
clean = (b->mode == o->mode);
/*
* FIXME: If opt->priv->call_depth && !clean, then we really
* should not make result->mode match either a->mode or
* b->mode; that causes t6036 "check conflicting mode for
* regular file" to fail. It would be best to use some other
* mode, but we'll confuse all kinds of stuff if we use one
* where S_ISREG(result->mode) isn't true, and if we use
* something like 0100666, then tree-walk.c's calls to
* canon_mode() will just normalize that to 100644 for us and
* thus not solve anything.
*
* Figure out if there's some kind of way we can work around
* this...
*/
}
/*
* Trivial oid merge.
*
* Note: While one might assume that the next four lines would
* be unnecessary due to the fact that match_mask is often
* setup and already handled, renames don't always take care
* of that.
*/
if (oideq(&a->oid, &b->oid) || oideq(&a->oid, &o->oid))
oidcpy(&result->oid, &b->oid);
else if (oideq(&b->oid, &o->oid))
oidcpy(&result->oid, &a->oid);
/* Remaining rules depend on file vs. submodule vs. symlink. */
else if (S_ISREG(a->mode)) {
mmbuffer_t result_buf;
int ret = 0, merge_status;
int two_way;
/*
* If 'o' is different type, treat it as null so we do a
* two-way merge.
*/
two_way = ((S_IFMT & o->mode) != (S_IFMT & a->mode));
merge_status = merge_3way(opt, path,
two_way ? null_oid() : &o->oid,
&a->oid, &b->oid,
pathnames, extra_marker_size,
&result_buf);
if ((merge_status < 0) || !result_buf.ptr)
ret = err(opt, _("Failed to execute internal merge"));
if (!ret &&
write_object_file(result_buf.ptr, result_buf.size,
OBJ_BLOB, &result->oid))
ret = err(opt, _("Unable to add %s to database"),
path);
free(result_buf.ptr);
if (ret)
return -1;
clean &= (merge_status == 0);
path_msg(opt, INFO_AUTO_MERGING, 1, path, NULL, NULL, NULL,
_("Auto-merging %s"), path);
} else if (S_ISGITLINK(a->mode)) {
int two_way = ((S_IFMT & o->mode) != (S_IFMT & a->mode));
clean = merge_submodule(opt, pathnames[0],
two_way ? null_oid() : &o->oid,
&a->oid, &b->oid, &result->oid);
if (opt->priv->call_depth && two_way && !clean) {
result->mode = o->mode;
oidcpy(&result->oid, &o->oid);
}
} else if (S_ISLNK(a->mode)) {
if (opt->priv->call_depth) {
clean = 0;
result->mode = o->mode;
oidcpy(&result->oid, &o->oid);
} else {
switch (opt->recursive_variant) {
case MERGE_VARIANT_NORMAL:
clean = 0;
oidcpy(&result->oid, &a->oid);
break;
case MERGE_VARIANT_OURS:
oidcpy(&result->oid, &a->oid);
break;
case MERGE_VARIANT_THEIRS:
oidcpy(&result->oid, &b->oid);
break;
}
}
} else
BUG("unsupported object type in the tree: %06o for %s",
a->mode, path);
return clean;
}
/*** Function Grouping: functions related to detect_and_process_renames(), ***
*** which are split into directory and regular rename detection sections. ***/
/*** Function Grouping: functions related to directory rename detection ***/
struct collision_info {
struct string_list source_files;
unsigned reported_already:1;
};
/*
* Return a new string that replaces the beginning portion (which matches
* rename_info->key), with rename_info->util.new_dir. In perl-speak:
* new_path_name = (old_path =~ s/rename_info->key/rename_info->value/);
* NOTE:
* Caller must ensure that old_path starts with rename_info->key + '/'.
*/
static char *apply_dir_rename(struct strmap_entry *rename_info,
const char *old_path)
{
struct strbuf new_path = STRBUF_INIT;
const char *old_dir = rename_info->key;
const char *new_dir = rename_info->value;
int oldlen, newlen, new_dir_len;
oldlen = strlen(old_dir);
if (*new_dir == '\0')
/*
* If someone renamed/merged a subdirectory into the root
* directory (e.g. 'some/subdir' -> ''), then we want to
* avoid returning
* '' + '/filename'
* as the rename; we need to make old_path + oldlen advance
* past the '/' character.
*/
oldlen++;
new_dir_len = strlen(new_dir);
newlen = new_dir_len + (strlen(old_path) - oldlen) + 1;
strbuf_grow(&new_path, newlen);
strbuf_add(&new_path, new_dir, new_dir_len);
strbuf_addstr(&new_path, &old_path[oldlen]);
return strbuf_detach(&new_path, NULL);
}
static int path_in_way(struct strmap *paths, const char *path, unsigned side_mask)
{
struct merged_info *mi = strmap_get(paths, path);
struct conflict_info *ci;
if (!mi)
return 0;
INITIALIZE_CI(ci, mi);
return mi->clean || (side_mask & (ci->filemask | ci->dirmask));
}
/*
* See if there is a directory rename for path, and if there are any file
* level conflicts on the given side for the renamed location. If there is
* a rename and there are no conflicts, return the new name. Otherwise,
* return NULL.
*/
static char *handle_path_level_conflicts(struct merge_options *opt,
const char *path,
unsigned side_index,
struct strmap_entry *rename_info,
struct strmap *collisions)
{
char *new_path = NULL;
struct collision_info *c_info;
int clean = 1;
struct strbuf collision_paths = STRBUF_INIT;
/*
* entry has the mapping of old directory name to new directory name
* that we want to apply to path.
*/
new_path = apply_dir_rename(rename_info, path);
if (!new_path)
BUG("Failed to apply directory rename!");
/*
* The caller needs to have ensured that it has pre-populated
* collisions with all paths that map to new_path. Do a quick check
* to ensure that's the case.
*/
c_info = strmap_get(collisions, new_path);
if (!c_info)
BUG("c_info is NULL");
/*
* Check for one-sided add/add/.../add conflicts, i.e.
* where implicit renames from the other side doing
* directory rename(s) can affect this side of history
* to put multiple paths into the same location. Warn
* and bail on directory renames for such paths.
*/
if (c_info->reported_already) {
clean = 0;
} else if (path_in_way(&opt->priv->paths, new_path, 1 << side_index)) {
c_info->reported_already = 1;
strbuf_add_separated_string_list(&collision_paths, ", ",
&c_info->source_files);
path_msg(opt, CONFLICT_DIR_RENAME_FILE_IN_WAY, 0,
new_path, NULL, NULL, &c_info->source_files,
_("CONFLICT (implicit dir rename): Existing "
"file/dir at %s in the way of implicit "
"directory rename(s) putting the following "
"path(s) there: %s."),
new_path, collision_paths.buf);
clean = 0;
} else if (c_info->source_files.nr > 1) {
c_info->reported_already = 1;
strbuf_add_separated_string_list(&collision_paths, ", ",
&c_info->source_files);
path_msg(opt, CONFLICT_DIR_RENAME_COLLISION, 0,
new_path, NULL, NULL, &c_info->source_files,
_("CONFLICT (implicit dir rename): Cannot map "
"more than one path to %s; implicit directory "
"renames tried to put these paths there: %s"),
new_path, collision_paths.buf);
clean = 0;
}
/* Free memory we no longer need */
strbuf_release(&collision_paths);
if (!clean && new_path) {
free(new_path);
return NULL;
}
return new_path;
}
static void get_provisional_directory_renames(struct merge_options *opt,
unsigned side,
int *clean)
{
struct hashmap_iter iter;
struct strmap_entry *entry;
struct rename_info *renames = &opt->priv->renames;
/*
* Collapse
* dir_rename_count: old_directory -> {new_directory -> count}
* down to
* dir_renames: old_directory -> best_new_directory
* where best_new_directory is the one with the unique highest count.
*/
strmap_for_each_entry(&renames->dir_rename_count[side], &iter, entry) {
const char *source_dir = entry->key;
struct strintmap *counts = entry->value;
struct hashmap_iter count_iter;
struct strmap_entry *count_entry;
int max = 0;
int bad_max = 0;
const char *best = NULL;
strintmap_for_each_entry(counts, &count_iter, count_entry) {
const char *target_dir = count_entry->key;
intptr_t count = (intptr_t)count_entry->value;
if (count == max)
bad_max = max;
else if (count > max) {
max = count;
best = target_dir;
}
}
if (max == 0)
continue;
if (bad_max == max) {
path_msg(opt, CONFLICT_DIR_RENAME_SPLIT, 0,
source_dir, NULL, NULL, NULL,
_("CONFLICT (directory rename split): "
"Unclear where to rename %s to; it was "
"renamed to multiple other directories, "
"with no destination getting a majority of "
"the files."),
source_dir);
*clean = 0;
} else {
strmap_put(&renames->dir_renames[side],
source_dir, (void*)best);
}
}
}
static void handle_directory_level_conflicts(struct merge_options *opt)
{
struct hashmap_iter iter;
struct strmap_entry *entry;
struct string_list duplicated = STRING_LIST_INIT_NODUP;
struct rename_info *renames = &opt->priv->renames;
struct strmap *side1_dir_renames = &renames->dir_renames[MERGE_SIDE1];
struct strmap *side2_dir_renames = &renames->dir_renames[MERGE_SIDE2];
int i;
strmap_for_each_entry(side1_dir_renames, &iter, entry) {
if (strmap_contains(side2_dir_renames, entry->key))
string_list_append(&duplicated, entry->key);
}
for (i = 0; i < duplicated.nr; i++) {
strmap_remove(side1_dir_renames, duplicated.items[i].string, 0);
strmap_remove(side2_dir_renames, duplicated.items[i].string, 0);
}
string_list_clear(&duplicated, 0);
}
static struct strmap_entry *check_dir_renamed(const char *path,
struct strmap *dir_renames)
{
char *temp = xstrdup(path);
char *end;
struct strmap_entry *e = NULL;
while ((end = strrchr(temp, '/'))) {
*end = '\0';
e = strmap_get_entry(dir_renames, temp);
if (e)
break;
}
free(temp);
return e;
}
static void compute_collisions(struct strmap *collisions,
struct strmap *dir_renames,
struct diff_queue_struct *pairs)
{
int i;
strmap_init_with_options(collisions, NULL, 0);
if (strmap_empty(dir_renames))
return;
/*
* Multiple files can be mapped to the same path due to directory
* renames done by the other side of history. Since that other
* side of history could have merged multiple directories into one,
* if our side of history added the same file basename to each of
* those directories, then all N of them would get implicitly
* renamed by the directory rename detection into the same path,
* and we'd get an add/add/.../add conflict, and all those adds
* from *this* side of history. This is not representable in the
* index, and users aren't going to easily be able to make sense of
* it. So we need to provide a good warning about what's
* happening, and fall back to no-directory-rename detection
* behavior for those paths.
*
* See testcases 9e and all of section 5 from t6043 for examples.
*/
for (i = 0; i < pairs->nr; ++i) {
struct strmap_entry *rename_info;
struct collision_info *collision_info;
char *new_path;
struct diff_filepair *pair = pairs->queue[i];
if (pair->status != 'A' && pair->status != 'R')
continue;
rename_info = check_dir_renamed(pair->two->path, dir_renames);
if (!rename_info)
continue;
new_path = apply_dir_rename(rename_info, pair->two->path);
assert(new_path);
collision_info = strmap_get(collisions, new_path);
if (collision_info) {
free(new_path);
} else {
CALLOC_ARRAY(collision_info, 1);
string_list_init_nodup(&collision_info->source_files);
strmap_put(collisions, new_path, collision_info);
}
string_list_insert(&collision_info->source_files,
pair->two->path);
}
}
static void free_collisions(struct strmap *collisions)
{
struct hashmap_iter iter;
struct strmap_entry *entry;
/* Free each value in the collisions map */
strmap_for_each_entry(collisions, &iter, entry) {
struct collision_info *info = entry->value;
string_list_clear(&info->source_files, 0);
}
/*
* In compute_collisions(), we set collisions.strdup_strings to 0
* so that we wouldn't have to make another copy of the new_path
* allocated by apply_dir_rename(). But now that we've used them
* and have no other references to these strings, it is time to
* deallocate them.
*/
free_strmap_strings(collisions);
strmap_clear(collisions, 1);
}
static char *check_for_directory_rename(struct merge_options *opt,
const char *path,
unsigned side_index,
struct strmap *dir_renames,
struct strmap *dir_rename_exclusions,
struct strmap *collisions,
int *clean_merge)
{
char *new_path;
struct strmap_entry *rename_info;
struct strmap_entry *otherinfo;
const char *new_dir;
int other_side = 3 - side_index;
/*
* Cases where we don't have or don't want a directory rename for
* this path.
*/
if (strmap_empty(dir_renames))
return NULL;
if (strmap_get(&collisions[other_side], path))
return NULL;
rename_info = check_dir_renamed(path, dir_renames);
if (!rename_info)
return NULL;
/*
* This next part is a little weird. We do not want to do an
* implicit rename into a directory we renamed on our side, because
* that will result in a spurious rename/rename(1to2) conflict. An
* example:
* Base commit: dumbdir/afile, otherdir/bfile
* Side 1: smrtdir/afile, otherdir/bfile
* Side 2: dumbdir/afile, dumbdir/bfile
* Here, while working on Side 1, we could notice that otherdir was
* renamed/merged to dumbdir, and change the diff_filepair for
* otherdir/bfile into a rename into dumbdir/bfile. However, Side
* 2 will notice the rename from dumbdir to smrtdir, and do the
* transitive rename to move it from dumbdir/bfile to
* smrtdir/bfile. That gives us bfile in dumbdir vs being in
* smrtdir, a rename/rename(1to2) conflict. We really just want
* the file to end up in smrtdir. And the way to achieve that is
* to not let Side1 do the rename to dumbdir, since we know that is
* the source of one of our directory renames.
*
* That's why otherinfo and dir_rename_exclusions is here.
*
* As it turns out, this also prevents N-way transient rename
* confusion; See testcases 9c and 9d of t6043.
*/
new_dir = rename_info->value; /* old_dir = rename_info->key; */
otherinfo = strmap_get_entry(dir_rename_exclusions, new_dir);
if (otherinfo) {
path_msg(opt, INFO_DIR_RENAME_SKIPPED_DUE_TO_RERENAME, 1,
rename_info->key, path, new_dir, NULL,
_("WARNING: Avoiding applying %s -> %s rename "
"to %s, because %s itself was renamed."),
rename_info->key, new_dir, path, new_dir);
return NULL;
}
new_path = handle_path_level_conflicts(opt, path, side_index,
rename_info,
&collisions[side_index]);
*clean_merge &= (new_path != NULL);
return new_path;
}
static void apply_directory_rename_modifications(struct merge_options *opt,
struct diff_filepair *pair,
char *new_path)
{
/*
* The basic idea is to get the conflict_info from opt->priv->paths
* at old path, and insert it into new_path; basically just this:
* ci = strmap_get(&opt->priv->paths, old_path);
* strmap_remove(&opt->priv->paths, old_path, 0);
* strmap_put(&opt->priv->paths, new_path, ci);
* However, there are some factors complicating this:
* - opt->priv->paths may already have an entry at new_path
* - Each ci tracks its containing directory, so we need to
* update that
* - If another ci has the same containing directory, then
* the two char*'s MUST point to the same location. See the
* comment in struct merged_info. strcmp equality is not
* enough; we need pointer equality.
* - opt->priv->paths must hold the parent directories of any
* entries that are added. So, if this directory rename
* causes entirely new directories, we must recursively add
* parent directories.
* - For each parent directory added to opt->priv->paths, we
* also need to get its parent directory stored in its
* conflict_info->merged.directory_name with all the same
* requirements about pointer equality.
*/
struct string_list dirs_to_insert = STRING_LIST_INIT_NODUP;
struct conflict_info *ci, *new_ci;
struct strmap_entry *entry;
const char *branch_with_new_path, *branch_with_dir_rename;
const char *old_path = pair->two->path;
const char *parent_name;
const char *cur_path;
int i, len;
entry = strmap_get_entry(&opt->priv->paths, old_path);
old_path = entry->key;
ci = entry->value;
VERIFY_CI(ci);
/* Find parent directories missing from opt->priv->paths */
cur_path = mem_pool_strdup(&opt->priv->pool, new_path);
free((char*)new_path);
new_path = (char *)cur_path;
while (1) {
/* Find the parent directory of cur_path */
char *last_slash = strrchr(cur_path, '/');
if (last_slash) {
parent_name = mem_pool_strndup(&opt->priv->pool,
cur_path,
last_slash - cur_path);
} else {
parent_name = opt->priv->toplevel_dir;
break;
}
/* Look it up in opt->priv->paths */
entry = strmap_get_entry(&opt->priv->paths, parent_name);
if (entry) {
parent_name = entry->key; /* reuse known pointer */
break;
}
/* Record this is one of the directories we need to insert */
string_list_append(&dirs_to_insert, parent_name);
cur_path = parent_name;
}
/* Traverse dirs_to_insert and insert them into opt->priv->paths */
for (i = dirs_to_insert.nr-1; i >= 0; --i) {
struct conflict_info *dir_ci;
char *cur_dir = dirs_to_insert.items[i].string;
CALLOC_ARRAY(dir_ci, 1);
dir_ci->merged.directory_name = parent_name;
len = strlen(parent_name);
/* len+1 because of trailing '/' character */
dir_ci->merged.basename_offset = (len > 0 ? len+1 : len);
dir_ci->dirmask = ci->filemask;
strmap_put(&opt->priv->paths, cur_dir, dir_ci);
parent_name = cur_dir;
}
assert(ci->filemask == 2 || ci->filemask == 4);
assert(ci->dirmask == 0 || ci->dirmask == 1);
if (ci->dirmask == 0)
strmap_remove(&opt->priv->paths, old_path, 0);
else {
/*
* This file exists on one side, but we still had a directory
* at the old location that we can't remove until after
* processing all paths below it. So, make a copy of ci in
* new_ci and only put the file information into it.
*/
new_ci = mem_pool_calloc(&opt->priv->pool, 1, sizeof(*new_ci));
memcpy(new_ci, ci, sizeof(*ci));
assert(!new_ci->match_mask);
new_ci->dirmask = 0;
new_ci->stages[1].mode = 0;
oidcpy(&new_ci->stages[1].oid, null_oid());
/*
* Now that we have the file information in new_ci, make sure
* ci only has the directory information.
*/
ci->filemask = 0;
ci->merged.clean = 1;
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
if (ci->dirmask & (1 << i))
continue;
/* zero out any entries related to files */
ci->stages[i].mode = 0;
oidcpy(&ci->stages[i].oid, null_oid());
}
// Now we want to focus on new_ci, so reassign ci to it
ci = new_ci;
}
branch_with_new_path = (ci->filemask == 2) ? opt->branch1 : opt->branch2;
branch_with_dir_rename = (ci->filemask == 2) ? opt->branch2 : opt->branch1;
/* Now, finally update ci and stick it into opt->priv->paths */
ci->merged.directory_name = parent_name;
len = strlen(parent_name);
ci->merged.basename_offset = (len > 0 ? len+1 : len);
new_ci = strmap_get(&opt->priv->paths, new_path);
if (!new_ci) {
/* Place ci back into opt->priv->paths, but at new_path */
strmap_put(&opt->priv->paths, new_path, ci);
} else {
int index;
/* A few sanity checks */
VERIFY_CI(new_ci);
assert(ci->filemask == 2 || ci->filemask == 4);
assert((new_ci->filemask & ci->filemask) == 0);
assert(!new_ci->merged.clean);
/* Copy stuff from ci into new_ci */
new_ci->filemask |= ci->filemask;
if (new_ci->dirmask)
new_ci->df_conflict = 1;
index = (ci->filemask >> 1);
new_ci->pathnames[index] = ci->pathnames[index];
new_ci->stages[index].mode = ci->stages[index].mode;
oidcpy(&new_ci->stages[index].oid, &ci->stages[index].oid);
ci = new_ci;
}
if (opt->detect_directory_renames == MERGE_DIRECTORY_RENAMES_TRUE) {
/* Notify user of updated path */
if (pair->status == 'A')
path_msg(opt, INFO_DIR_RENAME_APPLIED, 1,
new_path, old_path, NULL, NULL,
_("Path updated: %s added in %s inside a "
"directory that was renamed in %s; moving "
"it to %s."),
old_path, branch_with_new_path,
branch_with_dir_rename, new_path);
else
path_msg(opt, INFO_DIR_RENAME_APPLIED, 1,
new_path, old_path, NULL, NULL,
_("Path updated: %s renamed to %s in %s, "
"inside a directory that was renamed in %s; "
"moving it to %s."),
pair->one->path, old_path, branch_with_new_path,
branch_with_dir_rename, new_path);
} else {
/*
* opt->detect_directory_renames has the value
* MERGE_DIRECTORY_RENAMES_CONFLICT, so mark these as conflicts.
*/
ci->path_conflict = 1;
if (pair->status == 'A')
path_msg(opt, CONFLICT_DIR_RENAME_SUGGESTED, 1,
new_path, old_path, NULL, NULL,
_("CONFLICT (file location): %s added in %s "
"inside a directory that was renamed in %s, "
"suggesting it should perhaps be moved to "
"%s."),
old_path, branch_with_new_path,
branch_with_dir_rename, new_path);
else
path_msg(opt, CONFLICT_DIR_RENAME_SUGGESTED, 1,
new_path, old_path, NULL, NULL,
_("CONFLICT (file location): %s renamed to %s "
"in %s, inside a directory that was renamed "
"in %s, suggesting it should perhaps be "
"moved to %s."),
pair->one->path, old_path, branch_with_new_path,
branch_with_dir_rename, new_path);
}
/*
* Finally, record the new location.
*/
pair->two->path = new_path;
}
/*** Function Grouping: functions related to regular rename detection ***/
static int process_renames(struct merge_options *opt,
struct diff_queue_struct *renames)
{
int clean_merge = 1, i;
for (i = 0; i < renames->nr; ++i) {
const char *oldpath = NULL, *newpath;
struct diff_filepair *pair = renames->queue[i];
struct conflict_info *oldinfo = NULL, *newinfo = NULL;
struct strmap_entry *old_ent, *new_ent;
unsigned int old_sidemask;
int target_index, other_source_index;
int source_deleted, collision, type_changed;
const char *rename_branch = NULL, *delete_branch = NULL;
old_ent = strmap_get_entry(&opt->priv->paths, pair->one->path);
new_ent = strmap_get_entry(&opt->priv->paths, pair->two->path);
if (old_ent) {
oldpath = old_ent->key;
oldinfo = old_ent->value;
}
newpath = pair->two->path;
if (new_ent) {
newpath = new_ent->key;
newinfo = new_ent->value;
}
/*
* If pair->one->path isn't in opt->priv->paths, that means
* that either directory rename detection removed that
* path, or a parent directory of oldpath was resolved and
* we don't even need the rename; in either case, we can
* skip it. If oldinfo->merged.clean, then the other side
* of history had no changes to oldpath and we don't need
* the rename and can skip it.
*/
if (!oldinfo || oldinfo->merged.clean)
continue;
/*
* diff_filepairs have copies of pathnames, thus we have to
* use standard 'strcmp()' (negated) instead of '=='.
*/
if (i