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git/merge-ort.c

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/*
* "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"?)
*/
#define USE_THE_REPOSITORY_VARIABLE
#include "git-compat-util.h"
#include "merge-ort.h"
#include "alloc.h"
#include "advice.h"
#include "attr.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 "refs.h"
#include "revision.h"
#include "sparse-index.h"
#include "strmap.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,
/* INSERT NEW ENTRIES HERE */
/*
* Keep this entry after all regular conflict and info types; only
* errors (failures causing immediate abort of the merge) should
* come after this.
*/
NB_REGULAR_CONFLICT_TYPES,
/*
* Something is seriously wrong; cannot even perform merge;
* Keep this group _last_ other than NB_TOTAL_TYPES
*/
ERROR_SUBMODULE_CORRUPT,
ERROR_THREEWAY_CONTENT_MERGE_FAILED,
ERROR_OBJECT_WRITE_FAILED,
ERROR_OBJECT_READ_FAILED,
ERROR_OBJECT_NOT_A_BLOB,
/* Keep this entry _last_ in the list */
NB_TOTAL_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,
* please ensure the order matches what is used in 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)",
/* Something is seriously wrong; cannot even perform merge */
[ERROR_SUBMODULE_CORRUPT] =
"ERROR (submodule corrupt)",
[ERROR_THREEWAY_CONTENT_MERGE_FAILED] =
"ERROR (three-way content merge failed)",
[ERROR_OBJECT_WRITE_FAILED] =
"ERROR (object write failed)",
[ERROR_OBJECT_READ_FAILED] =
"ERROR (object read failed)",
[ERROR_OBJECT_NOT_A_BLOB] =
"ERROR (object is not a blob)",
};
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);
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;
}
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") &&
!starts_with(type_short_descriptions[type], "ERROR")) ||
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;
if (parse_tree(merge_base) < 0 ||
parse_tree(side1) < 0 ||
parse_tree(side2) < 0)
return -1;
init_tree_desc(t + 0, &merge_base->object.oid,
merge_base->buffer, merge_base->size);
init_tree_desc(t + 1, &side1->object.oid, side1->buffer, side1->size);
init_tree_desc(t + 2, &side2->object.oid, 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);
int ret = repo_in_merge_bases(repo, b, commit);
if (ret < 0) {
object_array_clear(&merges);
release_revisions(&revs);
return ret;
}
if (ret > 0)
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) {
int ret = repo_in_merge_bases(repo, m2, m1);
if (ret < 0) {
object_array_clear(&merges);
release_revisions(&revs);
return ret;
}
if (ret > 0) {
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, ret2;
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 */
ret2 = repo_in_merge_bases(&subrepo, commit_o, commit_a);
if (ret2 < 0) {
path_msg(opt, ERROR_SUBMODULE_CORRUPT, 0,
path, NULL, NULL, NULL,
_("error: failed to merge submodule %s "
"(repository corrupt)"),
path);
ret = -1;
goto cleanup;
}
if (ret2 > 0)
ret2 = repo_in_merge_bases(&subrepo, commit_o, commit_b);
if (ret2 < 0) {
path_msg(opt, ERROR_SUBMODULE_CORRUPT, 0,
path, NULL, NULL, NULL,
_("error: failed to merge submodule %s "
"(repository corrupt)"),
path);
ret = -1;
goto cleanup;
}
if (!ret2) {
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 */
ret2 = repo_in_merge_bases(&subrepo, commit_a, commit_b);
if (ret2 < 0) {
path_msg(opt, ERROR_SUBMODULE_CORRUPT, 0,
path, NULL, NULL, NULL,
_("error: failed to merge submodule %s "
"(repository corrupt)"),
path);
ret = -1;
goto cleanup;
}
if (ret2 > 0) {
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;
}
ret2 = repo_in_merge_bases(&subrepo, commit_b, commit_a);
if (ret2 < 0) {
path_msg(opt, ERROR_SUBMODULE_CORRUPT, 0,
path, NULL, NULL, NULL,
_("error: failed to merge submodule %s "
"(repository corrupt)"),
path);
ret = -1;
goto cleanup;
}
if (ret2 > 0) {
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 -1:
path_msg(opt, ERROR_SUBMODULE_CORRUPT, 0,
path, NULL, NULL, NULL,
_("error: failed to merge submodule %s "
"(repository corrupt)"),
path);
ret = -1;
break;
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->repo = opt->repo;
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 = LL_MERGE_OPTIONS_INIT;
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;
ll_opts.conflict_style = opt->conflict_style;
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 needed if we have content merges of content
* merges, which happens for example with rename/rename(2to1) and
* rename/add conflicts.
*/
int 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) {
path_msg(opt, ERROR_THREEWAY_CONTENT_MERGE_FAILED, 0,
pathnames[0], pathnames[1], pathnames[2], NULL,
_("error: failed to execute internal merge for %s"),
path);
ret = -1;
}
if (!ret &&
write_object_file(result_buf.ptr, result_buf.size,
OBJ_BLOB, &result->oid)) {
path_msg(opt, ERROR_OBJECT_WRITE_FAILED, 0,
pathnames[0], pathnames[1], pathnames[2], NULL,
_("error: unable to add %s to database"), path);
ret = -1;
}
free(result_buf.ptr);
if (ret)
return -1;
if (merge_status > 0)
clean = 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 (clean < 0)
return -1;
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 + 1 < renames->nr &&
!strcmp(oldpath, renames->queue[i+1]->one->path)) {
/* Handle rename/rename(1to2) or rename/rename(1to1) */
const char *pathnames[3];
struct version_info merged;
struct conflict_info *base, *side1, *side2;
unsigned was_binary_blob = 0;
pathnames[0] = oldpath;
pathnames[1] = newpath;
pathnames[2] = renames->queue[i+1]->two->path;
base = strmap_get(&opt->priv->paths, pathnames[0]);
side1 = strmap_get(&opt->priv->paths, pathnames[1]);
side2 = strmap_get(&opt->priv->paths, pathnames[2]);
VERIFY_CI(base);
VERIFY_CI(side1);
VERIFY_CI(side2);
if (!strcmp(pathnames[1], pathnames[2])) {
struct rename_info *ri = &opt->priv->renames;
int j;
/* Both sides renamed the same way */
assert(side1 == side2);
memcpy(&side1->stages[0], &base->stages[0],
sizeof(merged));
side1->filemask |= (1 << MERGE_BASE);
/* Mark base as resolved by removal */
base->merged.is_null = 1;
base->merged.clean = 1;
/*
* Disable remembering renames optimization;
* rename/rename(1to1) is incredibly rare, and
* just disabling the optimization is easier
* than purging cached_pairs,
* cached_target_names, and dir_rename_counts.
*/
for (j = 0; j < 3; j++)
ri->merge_trees[j] = NULL;
/* We handled both renames, i.e. i+1 handled */
i++;
/* Move to next rename */
continue;
}
/* This is a rename/rename(1to2) */
clean_merge = handle_content_merge(opt,
pair->one->path,
&base->stages[0],
&side1->stages[1],
&side2->stages[2],
pathnames,
1 + 2 * opt->priv->call_depth,
&merged);
if (clean_merge < 0)
return -1;
if (!clean_merge &&
merged.mode == side1->stages[1].mode &&
oideq(&merged.oid, &side1->stages[1].oid))
was_binary_blob = 1;
memcpy(&side1->stages[1], &merged, sizeof(merged));
if (was_binary_blob) {
/*
* Getting here means we were attempting to
* merge a binary blob.
*
* Since we can't merge binaries,
* handle_content_merge() just takes one
* side. But we don't want to copy the
* contents of one side to both paths. We
* used the contents of side1 above for
* side1->stages, let's use the contents of
* side2 for side2->stages below.
*/
oidcpy(&merged.oid, &side2->stages[2].oid);
merged.mode = side2->stages[2].mode;
}
memcpy(&side2->stages[2], &merged, sizeof(merged));
side1->path_conflict = 1;
side2->path_conflict = 1;
/*
* TODO: For renames we normally remove the path at the
* old name. It would thus seem consistent to do the
* same for rename/rename(1to2) cases, but we haven't
* done so traditionally and a number of the regression
* tests now encode an expectation that the file is
* left there at stage 1. If we ever decide to change
* this, add the following two lines here:
* base->merged.is_null = 1;
* base->merged.clean = 1;
* and remove the setting of base->path_conflict to 1.
*/
base->path_conflict = 1;
path_msg(opt, CONFLICT_RENAME_RENAME, 0,
pathnames[0], pathnames[1], pathnames[2], NULL,
_("CONFLICT (rename/rename): %s renamed to "
"%s in %s and to %s in %s."),
pathnames[0],
pathnames[1], opt->branch1,
pathnames[2], opt->branch2);
i++; /* We handled both renames, i.e. i+1 handled */
continue;
}
VERIFY_CI(oldinfo);
VERIFY_CI(newinfo);
target_index = pair->score; /* from collect_renames() */
assert(target_index == 1 || target_index == 2);
other_source_index = 3 - target_index;
old_sidemask = (1 << other_source_index); /* 2 or 4 */
source_deleted = (oldinfo->filemask == 1);
collision = ((newinfo->filemask & old_sidemask) != 0);
type_changed = !source_deleted &&
(S_ISREG(oldinfo->stages[other_source_index].mode) !=
S_ISREG(newinfo->stages[target_index].mode));
if (type_changed && collision) {
/*
* special handling so later blocks can handle this...
*
* if type_changed && collision are both true, then this
* was really a double rename, but one side wasn't
* detected due to lack of break detection. I.e.
* something like
* orig: has normal file 'foo'
* side1: renames 'foo' to 'bar', adds 'foo' symlink
* side2: renames 'foo' to 'bar'
* In this case, the foo->bar rename on side1 won't be
* detected because the new symlink named 'foo' is
* there and we don't do break detection. But we detect
* this here because we don't want to merge the content
* of the foo symlink with the foo->bar file, so we
* have some logic to handle this special case. The
* easiest way to do that is make 'bar' on side1 not
* be considered a colliding file but the other part
* of a normal rename. If the file is very different,
* well we're going to get content merge conflicts
* anyway so it doesn't hurt. And if the colliding
* file also has a different type, that'll be handled
* by the content merge logic in process_entry() too.
*
* See also t6430, 'rename vs. rename/symlink'
*/
collision = 0;
}
if (source_deleted) {
if (target_index == 1) {
rename_branch = opt->branch1;
delete_branch = opt->branch2;
} else {
rename_branch = opt->branch2;
delete_branch = opt->branch1;
}
}
assert(source_deleted || oldinfo->filemask & old_sidemask);
/* Need to check for special types of rename conflicts... */
if (collision && !source_deleted) {
/* collision: rename/add or rename/rename(2to1) */
const char *pathnames[3];
struct version_info merged;
struct conflict_info *base, *side1, *side2;
int clean;
pathnames[0] = oldpath;
pathnames[other_source_index] = oldpath;
pathnames[target_index] = newpath;
base = strmap_get(&opt->priv->paths, pathnames[0]);
side1 = strmap_get(&opt->priv->paths, pathnames[1]);
side2 = strmap_get(&opt->priv->paths, pathnames[2]);
VERIFY_CI(base);
VERIFY_CI(side1);
VERIFY_CI(side2);
clean = handle_content_merge(opt, pair->one->path,
&base->stages[0],
&side1->stages[1],
&side2->stages[2],
pathnames,
1 + 2 * opt->priv->call_depth,
&merged);
if (clean < 0)
return -1;
memcpy(&newinfo->stages[target_index], &merged,
sizeof(merged));
if (!clean) {
path_msg(opt, CONFLICT_RENAME_COLLIDES, 0,
newpath, oldpath, NULL, NULL,
_("CONFLICT (rename involved in "
"collision): rename of %s -> %s has "
"content conflicts AND collides "
"with another path; this may result "
"in nested conflict markers."),
oldpath, newpath);
}
} else if (collision && source_deleted) {
/*
* rename/add/delete or rename/rename(2to1)/delete:
* since oldpath was deleted on the side that didn't
* do the rename, there's not much of a content merge
* we can do for the rename. oldinfo->merged.is_null
* was already set, so we just leave things as-is so
* they look like an add/add conflict.
*/
newinfo->path_conflict = 1;
path_msg(opt, CONFLICT_RENAME_DELETE, 0,
newpath, oldpath, NULL, NULL,
_("CONFLICT (rename/delete): %s renamed "
"to %s in %s, but deleted in %s."),
oldpath, newpath, rename_branch, delete_branch);
} else {
/*
* a few different cases...start by copying the
* existing stage(s) from oldinfo over the newinfo
* and update the pathname(s).
*/
memcpy(&newinfo->stages[0], &oldinfo->stages[0],
sizeof(newinfo->stages[0]));
newinfo->filemask |= (1 << MERGE_BASE);
newinfo->pathnames[0] = oldpath;
if (type_changed) {
/* rename vs. typechange */
/* Mark the original as resolved by removal */
memcpy(&oldinfo->stages[0].oid, null_oid(),
sizeof(oldinfo->stages[0].oid));
oldinfo->stages[0].mode = 0;
oldinfo->filemask &= 0x06;
} else if (source_deleted) {
/* rename/delete */
newinfo->path_conflict = 1;
path_msg(opt, CONFLICT_RENAME_DELETE, 0,
newpath, oldpath, NULL, NULL,
_("CONFLICT (rename/delete): %s renamed"
" to %s in %s, but deleted in %s."),
oldpath, newpath,
rename_branch, delete_branch);
} else {
/* normal rename */
memcpy(&newinfo->stages[other_source_index],
&oldinfo->stages[other_source_index],
sizeof(newinfo->stages[0]));
newinfo->filemask |= (1 << other_source_index);
newinfo->pathnames[other_source_index] = oldpath;
}
}
if (!type_changed) {
/* Mark the original as resolved by removal */
oldinfo->merged.is_null = 1;
oldinfo->merged.clean = 1;
}
}
return clean_merge;
}
static inline int possible_side_renames(struct rename_info *renames,
unsigned side_index)
{
return renames->pairs[side_index].nr > 0 &&
!strintmap_empty(&renames->relevant_sources[side_index]);
}
static inline int possible_renames(struct rename_info *renames)
{
return possible_side_renames(renames, 1) ||
possible_side_renames(renames, 2) ||
!strmap_empty(&renames->cached_pairs[1]) ||
!strmap_empty(&renames->cached_pairs[2]);
}
static void resolve_diffpair_statuses(struct diff_queue_struct *q)
{
/*
* A simplified version of diff_resolve_rename_copy(); would probably
* just use that function but it's static...
*/
int i;
struct diff_filepair *p;
for (i = 0; i < q->nr; ++i) {
p = q->queue[i];
p->status = 0; /* undecided */
if (!DIFF_FILE_VALID(p->one))
p->status = DIFF_STATUS_ADDED;
else if (!DIFF_FILE_VALID(p->two))
p->status = DIFF_STATUS_DELETED;
else if (DIFF_PAIR_RENAME(p))
p->status = DIFF_STATUS_RENAMED;
}
}
static void prune_cached_from_relevant(struct rename_info *renames,
unsigned side)
{
/* Reason for this function described in add_pair() */
struct hashmap_iter iter;
struct strmap_entry *entry;
/* Remove from relevant_sources all entries in cached_pairs[side] */
strmap_for_each_entry(&renames->cached_pairs[side], &iter, entry) {
strintmap_remove(&renames->relevant_sources[side],
entry->key);
}
/* Remove from relevant_sources all entries in cached_irrelevant[side] */
strset_for_each_entry(&renames->cached_irrelevant[side], &iter, entry) {
strintmap_remove(&renames->relevant_sources[side],
entry->key);
}
}
static void use_cached_pairs(struct merge_options *opt,
struct strmap *cached_pairs,
struct diff_queue_struct *pairs)
{
struct hashmap_iter iter;
struct strmap_entry *entry;
/*
* Add to side_pairs all entries from renames->cached_pairs[side_index].
* (Info in cached_irrelevant[side_index] is not relevant here.)
*/
strmap_for_each_entry(cached_pairs, &iter, entry) {
struct diff_filespec *one, *two;
const char *old_name = entry->key;
const char *new_name = entry->value;
if (!new_name)
new_name = old_name;
/*
* cached_pairs has *copies* of old_name and new_name,
* because it has to persist across merges. Since
* pool_alloc_filespec() will just re-use the existing
* filenames, which will also get re-used by
* opt->priv->paths if they become renames, and then
* get freed at the end of the merge, that would leave
* the copy in cached_pairs dangling. Avoid this by
* making a copy here.
*/
old_name = mem_pool_strdup(&opt->priv->pool, old_name);
new_name = mem_pool_strdup(&opt->priv->pool, new_name);
/* We don't care about oid/mode, only filenames and status */
one = pool_alloc_filespec(&opt->priv->pool, old_name);
two = pool_alloc_filespec(&opt->priv->pool, new_name);
pool_diff_queue(&opt->priv->pool, pairs, one, two);
pairs->queue[pairs->nr-1]->status = entry->value ? 'R' : 'D';
}
}
static void cache_new_pair(struct rename_info *renames,
int side,
char *old_path,
char *new_path,
int free_old_value)
{
char *old_value;
new_path = xstrdup(new_path);
old_value = strmap_put(&renames->cached_pairs[side],
old_path, new_path);
strset_add(&renames->cached_target_names[side], new_path);
if (free_old_value)
free(old_value);
else
assert(!old_value);
}
static void possibly_cache_new_pair(struct rename_info *renames,
struct diff_filepair *p,
unsigned side,
char *new_path)
{
int dir_renamed_side = 0;
if (new_path) {
/*
* Directory renames happen on the other side of history from
* the side that adds new files to the old directory.
*/
dir_renamed_side = 3 - side;
} else {
int val = strintmap_get(&renames->relevant_sources[side],
p->one->path);
if (val == RELEVANT_NO_MORE) {
assert(p->status == 'D');
strset_add(&renames->cached_irrelevant[side],
p->one->path);
}
if (val <= 0)
return;
}
if (p->status == 'D') {
/*
* If we already had this delete, we'll just set it's value
* to NULL again, so no harm.
*/
strmap_put(&renames->cached_pairs[side], p->one->path, NULL);
} else if (p->status == 'R') {
if (!new_path)
new_path = p->two->path;
else
cache_new_pair(renames, dir_renamed_side,
p->two->path, new_path, 0);
cache_new_pair(renames, side, p->one->path, new_path, 1);
} else if (p->status == 'A' && new_path) {
cache_new_pair(renames, dir_renamed_side,
p->two->path, new_path, 0);
}
}
static int compare_pairs(const void *a_, const void *b_)
{
const struct diff_filepair *a = *((const struct diff_filepair **)a_);
const struct diff_filepair *b = *((const struct diff_filepair **)b_);
return strcmp(a->one->path, b->one->path);
}
/* Call diffcore_rename() to update deleted/added pairs into rename pairs */
static int detect_regular_renames(struct merge_options *opt,
unsigned side_index)
{
struct diff_options diff_opts;
struct rename_info *renames = &opt->priv->renames;
prune_cached_from_relevant(renames, side_index);
if (!possible_side_renames(renames, side_index)) {
/*
* No rename detection needed for this side, but we still need
* to make sure 'adds' are marked correctly in case the other
* side had directory renames.
*/
resolve_diffpair_statuses(&renames->pairs[side_index]);
return 0;
}
partial_clear_dir_rename_count(&renames->dir_rename_count[side_index]);
repo_diff_setup(opt->repo, &diff_opts);
diff_opts.flags.recursive = 1;
diff_opts.flags.rename_empty = 0;
diff_opts.detect_rename = DIFF_DETECT_RENAME;
diff_opts.rename_limit = opt->rename_limit;
if (opt->rename_limit <= 0)
diff_opts.rename_limit = 7000;
diff_opts.rename_score = opt->rename_score;
diff_opts.show_rename_progress = opt->show_rename_progress;
diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_setup_done(&diff_opts);
diff_queued_diff = renames->pairs[side_index];
trace2_region_enter("diff", "diffcore_rename", opt->repo);
diffcore_rename_extended(&diff_opts,
&opt->priv->pool,
&renames->relevant_sources[side_index],
&renames->dirs_removed[side_index],
&renames->dir_rename_count[side_index],
&renames->cached_pairs[side_index]);
trace2_region_leave("diff", "diffcore_rename", opt->repo);
resolve_diffpair_statuses(&diff_queued_diff);
if (diff_opts.needed_rename_limit > 0)
renames->redo_after_renames = 0;
if (diff_opts.needed_rename_limit > renames->needed_limit)
renames->needed_limit = diff_opts.needed_rename_limit;
renames->pairs[side_index] = diff_queued_diff;
diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_queued_diff.nr = 0;
diff_queued_diff.queue = NULL;
diff_flush(&diff_opts);
return 1;
}
/*
* Get information of all renames which occurred in 'side_pairs', making use
* of any implicit directory renames in side_dir_renames (also making use of
* implicit directory renames rename_exclusions as needed by
* check_for_directory_rename()). Add all (updated) renames into result.
*/
static int collect_renames(struct merge_options *opt,
struct diff_queue_struct *result,
unsigned side_index,
struct strmap *collisions,
struct strmap *dir_renames_for_side,
struct strmap *rename_exclusions)
{
int i, clean = 1;
struct diff_queue_struct *side_pairs;
struct rename_info *renames = &opt->priv->renames;
side_pairs = &renames->pairs[side_index];
for (i = 0; i < side_pairs->nr; ++i) {
struct diff_filepair *p = side_pairs->queue[i];
char *new_path; /* non-NULL only with directory renames */
if (p->status != 'A' && p->status != 'R') {
possibly_cache_new_pair(renames, p, side_index, NULL);
pool_diff_free_filepair(&opt->priv->pool, p);
continue;
}
new_path = check_for_directory_rename(opt, p->two->path,
side_index,
dir_renames_for_side,
rename_exclusions,
collisions,
&clean);
possibly_cache_new_pair(renames, p, side_index, new_path);
if (p->status != 'R' && !new_path) {
pool_diff_free_filepair(&opt->priv->pool, p);
continue;
}
if (new_path)
apply_directory_rename_modifications(opt, p, new_path);
/*
* p->score comes back from diffcore_rename_extended() with
* the similarity of the renamed file. The similarity is
* was used to determine that the two files were related
* and are a rename, which we have already used, but beyond
* that we have no use for the similarity. So p->score is
* now irrelevant. However, process_renames() will need to
* know which side of the merge this rename was associated
* with, so overwrite p->score with that value.
*/
p->score = side_index;
result->queue[result->nr++] = p;
}
return clean;
}
static int detect_and_process_renames(struct merge_options *opt)
{
struct diff_queue_struct combined = { 0 };
struct rename_info *renames = &opt->priv->renames;
struct strmap collisions[3];
int need_dir_renames, s, i, clean = 1;
unsigned detection_run = 0;
if (!possible_renames(renames))
goto cleanup;
trace2_region_enter("merge", "regular renames", opt->repo);
detection_run |= detect_regular_renames(opt, MERGE_SIDE1);
detection_run |= detect_regular_renames(opt, MERGE_SIDE2);
if (renames->needed_limit) {
renames->cached_pairs_valid_side = 0;
renames->redo_after_renames = 0;
}
if (renames->redo_after_renames && detection_run) {
int i, side;
struct diff_filepair *p;
/* Cache the renames, we found */
for (side = MERGE_SIDE1; side <= MERGE_SIDE2; side++) {
for (i = 0; i < renames->pairs[side].nr; ++i) {
p = renames->pairs[side].queue[i];
possibly_cache_new_pair(renames, p, side, NULL);
}
}
/* Restart the merge with the cached renames */
renames->redo_after_renames = 2;
trace2_region_leave("merge", "regular renames", opt->repo);
goto cleanup;
}
use_cached_pairs(opt, &renames->cached_pairs[1], &renames->pairs[1]);
use_cached_pairs(opt, &renames->cached_pairs[2], &renames->pairs[2]);
trace2_region_leave("merge", "regular renames", opt->repo);
trace2_region_enter("merge", "directory renames", opt->repo);
need_dir_renames =
!opt->priv->call_depth &&
(opt->detect_directory_renames == MERGE_DIRECTORY_RENAMES_TRUE ||
opt->detect_directory_renames == MERGE_DIRECTORY_RENAMES_CONFLICT);
if (need_dir_renames) {
get_provisional_directory_renames(opt, MERGE_SIDE1, &clean);
get_provisional_directory_renames(opt, MERGE_SIDE2, &clean);
handle_directory_level_conflicts(opt);
}
ALLOC_GROW(combined.queue,
renames->pairs[1].nr + renames->pairs[2].nr,
combined.alloc);
for (i = MERGE_SIDE1; i <= MERGE_SIDE2; i++) {
int other_side = 3 - i;
compute_collisions(&collisions[i],
&renames->dir_renames[other_side],
&renames->pairs[i]);
}
clean &= collect_renames(opt, &combined, MERGE_SIDE1,
collisions,
&renames->dir_renames[2],
&renames->dir_renames[1]);
clean &= collect_renames(opt, &combined, MERGE_SIDE2,
collisions,
&renames->dir_renames[1],
&renames->dir_renames[2]);
for (i = MERGE_SIDE1; i <= MERGE_SIDE2; i++)
free_collisions(&collisions[i]);
STABLE_QSORT(combined.queue, combined.nr, compare_pairs);
trace2_region_leave("merge", "directory renames", opt->repo);
trace2_region_enter("merge", "process renames", opt->repo);
clean &= process_renames(opt, &combined);
trace2_region_leave("merge", "process renames", opt->repo);
goto simple_cleanup; /* collect_renames() handles some of cleanup */
cleanup:
/*
* Free now unneeded filepairs, which would have been handled
* in collect_renames() normally but we skipped that code.
*/
for (s = MERGE_SIDE1; s <= MERGE_SIDE2; s++) {
struct diff_queue_struct *side_pairs;
int i;
side_pairs = &renames->pairs[s];
for (i = 0; i < side_pairs->nr; ++i) {
struct diff_filepair *p = side_pairs->queue[i];
pool_diff_free_filepair(&opt->priv->pool, p);
}
}
simple_cleanup:
/* Free memory for renames->pairs[] and combined */
for (s = MERGE_SIDE1; s <= MERGE_SIDE2; s++) {
free(renames->pairs[s].queue);
DIFF_QUEUE_CLEAR(&renames->pairs[s]);
}
for (i = 0; i < combined.nr; i++)
pool_diff_free_filepair(&opt->priv->pool, combined.queue[i]);
free(combined.queue);
return clean;
}
/*** Function Grouping: functions related to process_entries() ***/
static int sort_dirs_next_to_their_children(const char *one, const char *two)
{
unsigned char c1, c2;
/*
* Here we only care that entries for directories appear adjacent
* to and before files underneath the directory. We can achieve
* that by pretending to add a trailing slash to every file and
* then sorting. In other words, we do not want the natural
* sorting of
* foo
* foo.txt
* foo/bar
* Instead, we want "foo" to sort as though it were "foo/", so that
* we instead get
* foo.txt
* foo
* foo/bar
* To achieve this, we basically implement our own strcmp, except that
* if we get to the end of either string instead of comparing NUL to
* another character, we compare '/' to it.
*
* If this unusual "sort as though '/' were appended" perplexes
* you, perhaps it will help to note that this is not the final
* sort. write_tree() will sort again without the trailing slash
* magic, but just on paths immediately under a given tree.
*
* The reason to not use df_name_compare directly was that it was
* just too expensive (we don't have the string lengths handy), so
* it was reimplemented.
*/
/*
* NOTE: This function will never be called with two equal strings,
* because it is used to sort the keys of a strmap, and strmaps have
* unique keys by construction. That simplifies our c1==c2 handling
* below.
*/
while (*one && (*one == *two)) {
one++;
two++;
}
c1 = *one ? *one : '/';
c2 = *two ? *two : '/';
if (c1 == c2) {
/* Getting here means one is a leading directory of the other */
return (*one) ? 1 : -1;
} else
return c1 - c2;
}
static int read_oid_strbuf(struct merge_options *opt,
const struct object_id *oid,
struct strbuf *dst,
const char *path)
{
void *buf;
enum object_type type;
unsigned long size;
buf = repo_read_object_file(the_repository, oid, &type, &size);
if (!buf) {
path_msg(opt, ERROR_OBJECT_READ_FAILED, 0,
path, NULL, NULL, NULL,
_("error: cannot read object %s"), oid_to_hex(oid));
return -1;
}
if (type != OBJ_BLOB) {
free(buf);
path_msg(opt, ERROR_OBJECT_NOT_A_BLOB, 0,
path, NULL, NULL, NULL,
_("error: object %s is not a blob"), oid_to_hex(oid));
return -1;
}
strbuf_attach(dst, buf, size, size + 1);
return 0;
}
static int blob_unchanged(struct merge_options *opt,
const struct version_info *base,
const struct version_info *side,
const char *path)
{
struct strbuf basebuf = STRBUF_INIT;
struct strbuf sidebuf = STRBUF_INIT;
int ret = 0; /* assume changed for safety */
struct index_state *idx = &opt->priv->attr_index;
if (!idx->initialized)
initialize_attr_index(opt);
if (base->mode != side->mode)
return 0;
if (oideq(&base->oid, &side->oid))
return 1;
if (read_oid_strbuf(opt, &base->oid, &basebuf, path) ||
read_oid_strbuf(opt, &side->oid, &sidebuf, path))
goto error_return;
/*
* Note: binary | is used so that both renormalizations are
* performed. Comparison can be skipped if both files are
* unchanged since their sha1s have already been compared.
*/
if (renormalize_buffer(idx, path, basebuf.buf, basebuf.len, &basebuf) |
renormalize_buffer(idx, path, sidebuf.buf, sidebuf.len, &sidebuf))
ret = (basebuf.len == sidebuf.len &&
!memcmp(basebuf.buf, sidebuf.buf, basebuf.len));
error_return:
strbuf_release(&basebuf);
strbuf_release(&sidebuf);
return ret;
}
struct directory_versions {
/*
* versions: list of (basename -> version_info)
*
* The basenames are in reverse lexicographic order of full pathnames,
* as processed in process_entries(). This puts all entries within
* a directory together, and covers the directory itself after
* everything within it, allowing us to write subtrees before needing
* to record information for the tree itself.
*/
struct string_list versions;
/*
* offsets: list of (full relative path directories -> integer offsets)
*
* Since versions contains basenames from files in multiple different
* directories, we need to know which entries in versions correspond
* to which directories. Values of e.g.
* "" 0
* src 2
* src/moduleA 5
* Would mean that entries 0-1 of versions are files in the toplevel
* directory, entries 2-4 are files under src/, and the remaining
* entries starting at index 5 are files under src/moduleA/.
*/
struct string_list offsets;
/*
* last_directory: directory that previously processed file found in
*
* last_directory starts NULL, but records the directory in which the
* previous file was found within. As soon as
* directory(current_file) != last_directory
* then we need to start updating accounting in versions & offsets.
* Note that last_directory is always the last path in "offsets" (or
* NULL if "offsets" is empty) so this exists just for quick access.
*/
const char *last_directory;
/* last_directory_len: cached computation of strlen(last_directory) */
unsigned last_directory_len;
};
static int tree_entry_order(const void *a_, const void *b_)
{
const struct string_list_item *a = a_;
const struct string_list_item *b = b_;
const struct merged_info *ami = a->util;
const struct merged_info *bmi = b->util;
return base_name_compare(a->string, strlen(a->string), ami->result.mode,
b->string, strlen(b->string), bmi->result.mode);
}
static int write_tree(struct object_id *result_oid,
struct string_list *versions,
unsigned int offset,
size_t hash_size)
{
size_t maxlen = 0, extra;
unsigned int nr;
struct strbuf buf = STRBUF_INIT;
int i, ret = 0;
assert(offset <= versions->nr);
nr = versions->nr - offset;
if (versions->nr)
/* No need for STABLE_QSORT -- filenames must be unique */
QSORT(versions->items + offset, nr, tree_entry_order);
/* Pre-allocate some space in buf */
extra = hash_size + 8; /* 8: 6 for mode, 1 for space, 1 for NUL char */
for (i = 0; i < nr; i++) {
maxlen += strlen(versions->items[offset+i].string) + extra;
}
strbuf_grow(&buf, maxlen);
/* Write each entry out to buf */
for (i = 0; i < nr; i++) {
struct merged_info *mi = versions->items[offset+i].util;
struct version_info *ri = &mi->result;
strbuf_addf(&buf, "%o %s%c",
ri->mode,
versions->items[offset+i].string, '\0');
strbuf_add(&buf, ri->oid.hash, hash_size);
}
/* Write this object file out, and record in result_oid */
if (write_object_file(buf.buf, buf.len, OBJ_TREE, result_oid))
ret = -1;
strbuf_release(&buf);
return ret;
}
static void record_entry_for_tree(struct directory_versions *dir_metadata,
const char *path,
struct merged_info *mi)
{
const char *basename;
if (mi->is_null)
/* nothing to record */
return;
basename = path + mi->basename_offset;
assert(strchr(basename, '/') == NULL);
string_list_append(&dir_metadata->versions,
basename)->util = &mi->result;
}
static int write_completed_directory(struct merge_options *opt,
const char *new_directory_name,
struct directory_versions *info)
{
const char *prev_dir;
struct merged_info *dir_info = NULL;
unsigned int offset, ret = 0;
/*
* Some explanation of info->versions and info->offsets...
*
* process_entries() iterates over all relevant files AND
* directories in reverse lexicographic order, and calls this
* function. Thus, an example of the paths that process_entries()
* could operate on (along with the directories for those paths
* being shown) is:
*
* xtract.c ""
* tokens.txt ""
* src/moduleB/umm.c src/moduleB
* src/moduleB/stuff.h src/moduleB
* src/moduleB/baz.c src/moduleB
* src/moduleB src
* src/moduleA/foo.c src/moduleA
* src/moduleA/bar.c src/moduleA
* src/moduleA src
* src ""
* Makefile ""
*
* info->versions:
*
* always contains the unprocessed entries and their
* version_info information. For example, after the first five
* entries above, info->versions would be:
*
* xtract.c <xtract.c's version_info>
* token.txt <token.txt's version_info>
* umm.c <src/moduleB/umm.c's version_info>
* stuff.h <src/moduleB/stuff.h's version_info>
* baz.c <src/moduleB/baz.c's version_info>
*
* Once a subdirectory is completed we remove the entries in
* that subdirectory from info->versions, writing it as a tree
* (write_tree()). Thus, as soon as we get to src/moduleB,
* info->versions would be updated to
*
* xtract.c <xtract.c's version_info>
* token.txt <token.txt's version_info>
* moduleB <src/moduleB's version_info>
*
* info->offsets:
*
* helps us track which entries in info->versions correspond to
* which directories. When we are N directories deep (e.g. 4
* for src/modA/submod/subdir/), we have up to N+1 unprocessed
* directories (+1 because of toplevel dir). Corresponding to
* the info->versions example above, after processing five entries
* info->offsets will be:
*
* "" 0
* src/moduleB 2
*
* which is used to know that xtract.c & token.txt are from the
* toplevel dirctory, while umm.c & stuff.h & baz.c are from the
* src/moduleB directory. Again, following the example above,
* once we need to process src/moduleB, then info->offsets is
* updated to
*
* "" 0
* src 2
*
* which says that moduleB (and only moduleB so far) is in the
* src directory.
*
* One unique thing to note about info->offsets here is that
* "src" was not added to info->offsets until there was a path
* (a file OR directory) immediately below src/ that got
* processed.
*
* Since process_entry() just appends new entries to info->versions,
* write_completed_directory() only needs to do work if the next path
* is in a directory that is different than the last directory found
* in info->offsets.
*/
/*
* If we are working with the same directory as the last entry, there
* is no work to do. (See comments above the directory_name member of
* struct merged_info for why we can use pointer comparison instead of
* strcmp here.)
*/
if (new_directory_name == info->last_directory)
return 0;
/*
* If we are just starting (last_directory is NULL), or last_directory
* is a prefix of the current directory, then we can just update
* info->offsets to record the offset where we started this directory
* and update last_directory to have quick access to it.
*/
if (info->last_directory == NULL ||
!strncmp(new_directory_name, info->last_directory,
info->last_directory_len)) {
uintptr_t offset = info->versions.nr;
info->last_directory = new_directory_name;
info->last_directory_len = strlen(info->last_directory);
/*
* Record the offset into info->versions where we will
* start recording basenames of paths found within
* new_directory_name.
*/
string_list_append(&info->offsets,
info->last_directory)->util = (void*)offset;
return 0;
}
/*
* The next entry that will be processed will be within
* new_directory_name. Since at this point we know that
* new_directory_name is within a different directory than
* info->last_directory, we have all entries for info->last_directory
* in info->versions and we need to create a tree object for them.
*/
dir_info = strmap_get(&opt->priv->paths, info->last_directory);
assert(dir_info);
offset = (uintptr_t)info->offsets.items[info->offsets.nr-1].util;
if (offset == info->versions.nr) {
/*
* Actually, we don't need to create a tree object in this
* case. Whenever all files within a directory disappear
* during the merge (e.g. unmodified on one side and
* deleted on the other, or files were renamed elsewhere),
* then we get here and the directory itself needs to be
* omitted from its parent tree as well.
*/
dir_info->is_null = 1;
} else {
/*
* Write out the tree to the git object directory, and also
* record the mode and oid in dir_info->result.
*/
dir_info->is_null = 0;
dir_info->result.mode = S_IFDIR;
if (write_tree(&dir_info->result.oid, &info->versions, offset,
opt->repo->hash_algo->rawsz) < 0)
ret = -1;
}
/*
* We've now used several entries from info->versions and one entry
* from info->offsets, so we get rid of those values.
*/
info->offsets.nr--;
info->versions.nr = offset;
/*
* Now we've taken care of the completed directory, but we need to
* prepare things since future entries will be in
* new_directory_name. (In particular, process_entry() will be
* appending new entries to info->versions.) So, we need to make
* sure new_directory_name is the last entry in info->offsets.
*/
prev_dir = info->offsets.nr == 0 ? NULL :
info->offsets.items[info->offsets.nr-1].string;
if (new_directory_name != prev_dir) {
uintptr_t c = info->versions.nr;
string_list_append(&info->offsets,
new_directory_name)->util = (void*)c;
}
/* And, of course, we need to update last_directory to match. */
info->last_directory = new_directory_name;
info->last_directory_len = strlen(info->last_directory);
return ret;
}
/* Per entry merge function */
static int process_entry(struct merge_options *opt,
const char *path,
struct conflict_info *ci,
struct directory_versions *dir_metadata)
{
int df_file_index = 0;
VERIFY_CI(ci);
assert(ci->filemask >= 0 && ci->filemask <= 7);
/* ci->match_mask == 7 was handled in collect_merge_info_callback() */
assert(ci->match_mask == 0 || ci->match_mask == 3 ||
ci->match_mask == 5 || ci->match_mask == 6);
if (ci->dirmask) {
record_entry_for_tree(dir_metadata, path, &ci->merged);
if (ci->filemask == 0)
/* nothing else to handle */
return 0;
assert(ci->df_conflict);
}
if (ci->df_conflict && ci->merged.result.mode == 0) {
int i;
/*
* directory no longer in the way, but we do have a file we
* need to place here so we need to clean away the "directory
* merges to nothing" result.
*/
ci->df_conflict = 0;
assert(ci->filemask != 0);
ci->merged.clean = 0;
ci->merged.is_null = 0;
/* and we want to zero out any directory-related entries */
ci->match_mask = (ci->match_mask & ~ci->dirmask);
ci->dirmask = 0;
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
if (ci->filemask & (1 << i))
continue;
ci->stages[i].mode = 0;
oidcpy(&ci->stages[i].oid, null_oid());
}
} else if (ci->df_conflict && ci->merged.result.mode != 0) {
/*
* This started out as a D/F conflict, and the entries in
* the competing directory were not removed by the merge as
* evidenced by write_completed_directory() writing a value
* to ci->merged.result.mode.
*/
struct conflict_info *new_ci;
const char *branch;
const char *old_path = path;
int i;
assert(ci->merged.result.mode == S_IFDIR);
/*
* If filemask is 1, we can just ignore the file as having
* been deleted on both sides. We do not want to overwrite
* ci->merged.result, since it stores the tree for all the
* files under it.
*/
if (ci->filemask == 1) {
ci->filemask = 0;
return 0;
}
/*
* This file still exists on at least one side, and we want
* the directory to remain here, so we need to move this
* path to some new location.
*/
new_ci = mem_pool_calloc(&opt->priv->pool, 1, sizeof(*new_ci));
/* We don't really want new_ci->merged.result copied, but it'll
* be overwritten below so it doesn't matter. We also don't
* want any directory mode/oid values copied, but we'll zero
* those out immediately. We do want the rest of ci copied.
*/
memcpy(new_ci, ci, sizeof(*ci));
new_ci->match_mask = (new_ci->match_mask & ~new_ci->dirmask);
new_ci->dirmask = 0;
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
if (new_ci->filemask & (1 << i))
continue;
/* zero out any entries related to directories */
new_ci->stages[i].mode = 0;
oidcpy(&new_ci->stages[i].oid, null_oid());
}
/*
* Find out which side this file came from; note that we
* cannot just use ci->filemask, because renames could cause
* the filemask to go back to 7. So we use dirmask, then
* pick the opposite side's index.
*/
df_file_index = (ci->dirmask & (1 << 1)) ? 2 : 1;
branch = (df_file_index == 1) ? opt->branch1 : opt->branch2;
path = unique_path(opt, path, branch);
strmap_put(&opt->priv->paths, path, new_ci);
path_msg(opt, CONFLICT_FILE_DIRECTORY, 0,
path, old_path, NULL, NULL,
_("CONFLICT (file/directory): directory in the way "
"of %s from %s; moving it to %s instead."),
old_path, branch, path);
/*
* Zero out the filemask for the old ci. At this point, ci
* was just an entry for a directory, so we don't need to
* do anything more with it.
*/
ci->filemask = 0;
/*
* Now note that we're working on the new entry (path was
* updated above.
*/
ci = new_ci;
}
/*
* NOTE: Below there is a long switch-like if-elseif-elseif... block
* which the code goes through even for the df_conflict cases
* above.
*/
if (ci->match_mask) {
ci->merged.clean = !ci->df_conflict && !ci->path_conflict;
if (ci->match_mask == 6) {
/* stages[1] == stages[2] */
ci->merged.result.mode = ci->stages[1].mode;
oidcpy(&ci->merged.result.oid, &ci->stages[1].oid);
} else {
/* determine the mask of the side that didn't match */
unsigned int othermask = 7 & ~ci->match_mask;
int side = (othermask == 4) ? 2 : 1;
ci->merged.result.mode = ci->stages[side].mode;
ci->merged.is_null = !ci->merged.result.mode;
if (ci->merged.is_null)
ci->merged.clean = 1;
oidcpy(&ci->merged.result.oid, &ci->stages[side].oid);
assert(othermask == 2 || othermask == 4);
assert(ci->merged.is_null ==
(ci->filemask == ci->match_mask));
}
} else if (ci->filemask >= 6 &&
(S_IFMT & ci->stages[1].mode) !=
(S_IFMT & ci->stages[2].mode)) {
/* Two different items from (file/submodule/symlink) */
if (opt->priv->call_depth) {
/* Just use the version from the merge base */
ci->merged.clean = 0;
oidcpy(&ci->merged.result.oid, &ci->stages[0].oid);
ci->merged.result.mode = ci->stages[0].mode;
ci->merged.is_null = (ci->merged.result.mode == 0);
} else {
/* Handle by renaming one or both to separate paths. */
unsigned o_mode = ci->stages[0].mode;
unsigned a_mode = ci->stages[1].mode;
unsigned b_mode = ci->stages[2].mode;
struct conflict_info *new_ci;
const char *a_path = NULL, *b_path = NULL;
int rename_a = 0, rename_b = 0;
new_ci = mem_pool_alloc(&opt->priv->pool,
sizeof(*new_ci));
if (S_ISREG(a_mode))
rename_a = 1;
else if (S_ISREG(b_mode))
rename_b = 1;
else {
rename_a = 1;
rename_b = 1;
}
if (rename_a)
a_path = unique_path(opt, path, opt->branch1);
if (rename_b)
b_path = unique_path(opt, path, opt->branch2);
if (rename_a && rename_b) {
path_msg(opt, CONFLICT_DISTINCT_MODES, 0,
path, a_path, b_path, NULL,
_("CONFLICT (distinct types): %s had "
"different types on each side; "
"renamed both of them so each can "
"be recorded somewhere."),
path);
} else {
path_msg(opt, CONFLICT_DISTINCT_MODES, 0,
path, rename_a ? a_path : b_path,
NULL, NULL,
_("CONFLICT (distinct types): %s had "
"different types on each side; "
"renamed one of them so each can be "
"recorded somewhere."),
path);
}
ci->merged.clean = 0;
memcpy(new_ci, ci, sizeof(*new_ci));
/* Put b into new_ci, removing a from stages */
new_ci->merged.result.mode = ci->stages[2].mode;
oidcpy(&new_ci->merged.result.oid, &ci->stages[2].oid);
new_ci->stages[1].mode = 0;
oidcpy(&new_ci->stages[1].oid, null_oid());
new_ci->filemask = 5;
if ((S_IFMT & b_mode) != (S_IFMT & o_mode)) {
new_ci->stages[0].mode = 0;
oidcpy(&new_ci->stages[0].oid, null_oid());
new_ci->filemask = 4;
}
/* Leave only a in ci, fixing stages. */
ci->merged.result.mode = ci->stages[1].mode;
oidcpy(&ci->merged.result.oid, &ci->stages[1].oid);
ci->stages[2].mode = 0;
oidcpy(&ci->stages[2].oid, null_oid());
ci->filemask = 3;
if ((S_IFMT & a_mode) != (S_IFMT & o_mode)) {
ci->stages[0].mode = 0;
oidcpy(&ci->stages[0].oid, null_oid());
ci->filemask = 2;
}
/* Insert entries into opt->priv_paths */
assert(rename_a || rename_b);
if (rename_a)
strmap_put(&opt->priv->paths, a_path, ci);
if (!rename_b)
b_path = path;
strmap_put(&opt->priv->paths, b_path, new_ci);
if (rename_a && rename_b)
strmap_remove(&opt->priv->paths, path, 0);
/*
* Do special handling for b_path since process_entry()
* won't be called on it specially.
*/
strmap_put(&opt->priv->conflicted, b_path, new_ci);
record_entry_for_tree(dir_metadata, b_path,
&new_ci->merged);
/*
* Remaining code for processing this entry should
* think in terms of processing a_path.
*/
if (a_path)
path = a_path;
}
} else if (ci->filemask >= 6) {
/* Need a two-way or three-way content merge */
struct version_info merged_file;
int clean_merge;
struct version_info *o = &ci->stages[0];
struct version_info *a = &ci->stages[1];
struct version_info *b = &ci->stages[2];
clean_merge = handle_content_merge(opt, path, o, a, b,
ci->pathnames,
opt->priv->call_depth * 2,
&merged_file);
if (clean_merge < 0)
return -1;
ci->merged.clean = clean_merge &&
!ci->df_conflict && !ci->path_conflict;
ci->merged.result.mode = merged_file.mode;
ci->merged.is_null = (merged_file.mode == 0);
oidcpy(&ci->merged.result.oid, &merged_file.oid);
if (clean_merge && ci->df_conflict) {
assert(df_file_index == 1 || df_file_index == 2);
ci->filemask = 1 << df_file_index;
ci->stages[df_file_index].mode = merged_file.mode;
oidcpy(&ci->stages[df_file_index].oid, &merged_file.oid);
}
if (!clean_merge) {
const char *reason = _("content");
if (ci->filemask == 6)
reason = _("add/add");
if (S_ISGITLINK(merged_file.mode))
reason = _("submodule");
path_msg(opt, CONFLICT_CONTENTS, 0,
path, NULL, NULL, NULL,
_("CONFLICT (%s): Merge conflict in %s"),
reason, path);
}
} else if (ci->filemask == 3 || ci->filemask == 5) {
/* Modify/delete */
const char *modify_branch, *delete_branch;
int side = (ci->filemask == 5) ? 2 : 1;
int index = opt->priv->call_depth ? 0 : side;
ci->merged.result.mode = ci->stages[index].mode;
oidcpy(&ci->merged.result.oid, &ci->stages[index].oid);
ci->merged.clean = 0;
modify_branch = (side == 1) ? opt->branch1 : opt->branch2;
delete_branch = (side == 1) ? opt->branch2 : opt->branch1;
if (opt->renormalize &&
blob_unchanged(opt, &ci->stages[0], &ci->stages[side],
path)) {
if (!ci->path_conflict) {
/*
* Blob unchanged after renormalization, so
* there's no modify/delete conflict after all;
* we can just remove the file.
*/
ci->merged.is_null = 1;
ci->merged.clean = 1;
/*
* file goes away => even if there was a
* directory/file conflict there isn't one now.
*/
ci->df_conflict = 0;
} else {
/* rename/delete, so conflict remains */
}
} else if (ci->path_conflict &&
oideq(&ci->stages[0].oid, &ci->stages[side].oid)) {
/*
* This came from a rename/delete; no action to take,
* but avoid printing "modify/delete" conflict notice
* since the contents were not modified.
*/
} else {
path_msg(opt, CONFLICT_MODIFY_DELETE, 0,
path, NULL, NULL, NULL,
_("CONFLICT (modify/delete): %s deleted in %s "
"and modified in %s. Version %s of %s left "
"in tree."),
path, delete_branch, modify_branch,
modify_branch, path);
}
} else if (ci->filemask == 2 || ci->filemask == 4) {
/* Added on one side */
int side = (ci->filemask == 4) ? 2 : 1;
ci->merged.result.mode = ci->stages[side].mode;
oidcpy(&ci->merged.result.oid, &ci->stages[side].oid);
ci->merged.clean = !ci->df_conflict && !ci->path_conflict;
} else if (ci->filemask == 1) {
/* Deleted on both sides */
ci->merged.is_null = 1;
ci->merged.result.mode = 0;
oidcpy(&ci->merged.result.oid, null_oid());
assert(!ci->df_conflict);
ci->merged.clean = !ci->path_conflict;
}
/*
* If still conflicted, record it separately. This allows us to later
* iterate over just conflicted entries when updating the index instead
* of iterating over all entries.
*/
if (!ci->merged.clean)
strmap_put(&opt->priv->conflicted, path, ci);
/* Record metadata for ci->merged in dir_metadata */
record_entry_for_tree(dir_metadata, path, &ci->merged);
return 0;
}
static void prefetch_for_content_merges(struct merge_options *opt,
struct string_list *plist)
{
struct string_list_item *e;
struct oid_array to_fetch = OID_ARRAY_INIT;
if (opt->repo != the_repository || !repo_has_promisor_remote(the_repository))
return;
for (e = &plist->items[plist->nr-1]; e >= plist->items; --e) {
/* char *path = e->string; */
struct conflict_info *ci = e->util;
int i;
/* Ignore clean entries */
if (ci->merged.clean)
continue;
/* Ignore entries that don't need a content merge */
if (ci->match_mask || ci->filemask < 6 ||
!S_ISREG(ci->stages[1].mode) ||
!S_ISREG(ci->stages[2].mode) ||
oideq(&ci->stages[1].oid, &ci->stages[2].oid))
continue;
/* Also don't need content merge if base matches either side */
if (ci->filemask == 7 &&
S_ISREG(ci->stages[0].mode) &&
(oideq(&ci->stages[0].oid, &ci->stages[1].oid) ||
oideq(&ci->stages[0].oid, &ci->stages[2].oid)))
continue;
for (i = 0; i < 3; i++) {
unsigned side_mask = (1 << i);
struct version_info *vi = &ci->stages[i];
if ((ci->filemask & side_mask) &&
S_ISREG(vi->mode) &&
oid_object_info_extended(opt->repo, &vi->oid, NULL,
OBJECT_INFO_FOR_PREFETCH))
oid_array_append(&to_fetch, &vi->oid);
}
}
promisor_remote_get_direct(opt->repo, to_fetch.oid, to_fetch.nr);
oid_array_clear(&to_fetch);
}
static int process_entries(struct merge_options *opt,
struct object_id *result_oid)
{
struct hashmap_iter iter;
struct strmap_entry *e;
struct string_list plist = STRING_LIST_INIT_NODUP;
struct string_list_item *entry;
struct directory_versions dir_metadata = { STRING_LIST_INIT_NODUP,
STRING_LIST_INIT_NODUP,
NULL, 0 };
int ret = 0;
trace2_region_enter("merge", "process_entries setup", opt->repo);
if (strmap_empty(&opt->priv->paths)) {
oidcpy(result_oid, opt->repo->hash_algo->empty_tree);
return 0;
}
/* Hack to pre-allocate plist to the desired size */
trace2_region_enter("merge", "plist grow", opt->repo);
ALLOC_GROW(plist.items, strmap_get_size(&opt->priv->paths), plist.alloc);
trace2_region_leave("merge", "plist grow", opt->repo);
/* Put every entry from paths into plist, then sort */
trace2_region_enter("merge", "plist copy", opt->repo);
strmap_for_each_entry(&opt->priv->paths, &iter, e) {
string_list_append(&plist, e->key)->util = e->value;
}
trace2_region_leave("merge", "plist copy", opt->repo);
trace2_region_enter("merge", "plist special sort", opt->repo);
plist.cmp = sort_dirs_next_to_their_children;
string_list_sort(&plist);
trace2_region_leave("merge", "plist special sort", opt->repo);
trace2_region_leave("merge", "process_entries setup", opt->repo);
/*
* Iterate over the items in reverse order, so we can handle paths
* below a directory before needing to handle the directory itself.
*
* This allows us to write subtrees before we need to write trees,
* and it also enables sane handling of directory/file conflicts
* (because it allows us to know whether the directory is still in
* the way when it is time to process the file at the same path).
*/
trace2_region_enter("merge", "processing", opt->repo);
prefetch_for_content_merges(opt, &plist);
for (entry = &plist.items[plist.nr-1]; entry >= plist.items; --entry) {
char *path = entry->string;
/*
* NOTE: mi may actually be a pointer to a conflict_info, but
* we have to check mi->clean first to see if it's safe to
* reassign to such a pointer type.
*/
struct merged_info *mi = entry->util;
if (write_completed_directory(opt, mi->directory_name,
&dir_metadata) < 0) {
ret = -1;
goto cleanup;
}
if (mi->clean)
record_entry_for_tree(&dir_metadata, path, mi);
else {
struct conflict_info *ci = (struct conflict_info *)mi;
if (process_entry(opt, path, ci, &dir_metadata) < 0) {
ret = -1;
goto cleanup;
};
}
}
trace2_region_leave("merge", "processing", opt->repo);
trace2_region_enter("merge", "process_entries cleanup", opt->repo);
if (dir_metadata.offsets.nr != 1 ||
(uintptr_t)dir_metadata.offsets.items[0].util != 0) {
printf("dir_metadata.offsets.nr = %"PRIuMAX" (should be 1)\n",
(uintmax_t)dir_metadata.offsets.nr);
printf("dir_metadata.offsets.items[0].util = %u (should be 0)\n",
(unsigned)(uintptr_t)dir_metadata.offsets.items[0].util);
fflush(stdout);
BUG("dir_metadata accounting completely off; shouldn't happen");
}
if (write_tree(result_oid, &dir_metadata.versions, 0,
opt->repo->hash_algo->rawsz) < 0)
ret = -1;
cleanup:
string_list_clear(&plist, 0);
string_list_clear(&dir_metadata.versions, 0);
string_list_clear(&dir_metadata.offsets, 0);
trace2_region_leave("merge", "process_entries cleanup", opt->repo);
return ret;
}
/*** Function Grouping: functions related to merge_switch_to_result() ***/
static int checkout(struct merge_options *opt,
struct tree *prev,
struct tree *next)
{
/* Switch the index/working copy from old to new */
int ret;
struct tree_desc trees[2];
struct unpack_trees_options unpack_opts;
memset(&unpack_opts, 0, sizeof(unpack_opts));
unpack_opts.head_idx = -1;
unpack_opts.src_index = opt->repo->index;
unpack_opts.dst_index = opt->repo->index;
setup_unpack_trees_porcelain(&unpack_opts, "merge");
/*
* NOTE: if this were just "git checkout" code, we would probably
* read or refresh the cache and check for a conflicted index, but
* builtin/merge.c or sequencer.c really needs to read the index
* and check for conflicted entries before starting merging for a
* good user experience (no sense waiting for merges/rebases before
* erroring out), so there's no reason to duplicate that work here.
*/
/* 2-way merge to the new branch */
unpack_opts.update = 1;
unpack_opts.merge = 1;
unpack_opts.quiet = 0; /* FIXME: sequencer might want quiet? */
unpack_opts.verbose_update = (opt->verbosity > 2);
unpack_opts.fn = twoway_merge;
unpack_opts.preserve_ignored = 0; /* FIXME: !opts->overwrite_ignore */
if (parse_tree(prev) < 0)
return -1;
init_tree_desc(&trees[0], &prev->object.oid, prev->buffer, prev->size);
if (parse_tree(next) < 0)
return -1;
init_tree_desc(&trees[1], &next->object.oid, next->buffer, next->size);
ret = unpack_trees(2, trees, &unpack_opts);
clear_unpack_trees_porcelain(&unpack_opts);
return ret;
}
static int record_conflicted_index_entries(struct merge_options *opt)
{
struct hashmap_iter iter;
struct strmap_entry *e;
struct index_state *index = opt->repo->index;
struct checkout state = CHECKOUT_INIT;
int errs = 0;
int original_cache_nr;
if (strmap_empty(&opt->priv->conflicted))
return 0;
/*
* We are in a conflicted state. These conflicts might be inside
* sparse-directory entries, so check if any entries are outside
* of the sparse-checkout cone preemptively.
*
* We set original_cache_nr below, but that might change if
* index_name_pos() calls ask for paths within sparse directories.
*/
strmap_for_each_entry(&opt->priv->conflicted, &iter, e) {
if (!path_in_sparse_checkout(e->key, index)) {
ensure_full_index(index);
break;
}
}
/* If any entries have skip_worktree set, we'll have to check 'em out */
state.force = 1;
state.quiet = 1;
state.refresh_cache = 1;
state.istate = index;
original_cache_nr = index->cache_nr;
/* Append every entry from conflicted into index, then sort */
strmap_for_each_entry(&opt->priv->conflicted, &iter, e) {
const char *path = e->key;
struct conflict_info *ci = e->value;
int pos;
struct cache_entry *ce;
int i;
VERIFY_CI(ci);
/*
* The index will already have a stage=0 entry for this path,
* because we created an as-merged-as-possible version of the
* file and checkout() moved the working copy and index over
* to that version.
*
* However, previous iterations through this loop will have
* added unstaged entries to the end of the cache which
* ignore the standard alphabetical ordering of cache
* entries and break invariants needed for index_name_pos()
* to work. However, we know the entry we want is before
* those appended cache entries, so do a temporary swap on
* cache_nr to only look through entries of interest.
*/
SWAP(index->cache_nr, original_cache_nr);
pos = index_name_pos(index, path, strlen(path));
SWAP(index->cache_nr, original_cache_nr);
if (pos < 0) {
if (ci->filemask != 1)
BUG("Conflicted %s but nothing in basic working tree or index; this shouldn't happen", path);
cache_tree_invalidate_path(index, path);
} else {
ce = index->cache[pos];
/*
* Clean paths with CE_SKIP_WORKTREE set will not be
* written to the working tree by the unpack_trees()
* call in checkout(). Our conflicted entries would
* have appeared clean to that code since we ignored
* the higher order stages. Thus, we need override
* the CE_SKIP_WORKTREE bit and manually write those
* files to the working disk here.
*/
if (ce_skip_worktree(ce))
errs |= checkout_entry(ce, &state, NULL, NULL);
/*
* Mark this cache entry for removal and instead add
* new stage>0 entries corresponding to the
* conflicts. If there are many conflicted entries, we
* want to avoid memmove'ing O(NM) entries by
* inserting the new entries one at a time. So,
* instead, we just add the new cache entries to the
* end (ignoring normal index requirements on sort
* order) and sort the index once we're all done.
*/
ce->ce_flags |= CE_REMOVE;
}
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
struct version_info *vi;
if (!(ci->filemask & (1ul << i)))
continue;
vi = &ci->stages[i];
ce = make_cache_entry(index, vi->mode, &vi->oid,
path, i+1, 0);
add_index_entry(index, ce, ADD_CACHE_JUST_APPEND);
}
}
/*
* Remove the unused cache entries (and invalidate the relevant
* cache-trees), then sort the index entries to get the conflicted
* entries we added to the end into their right locations.
*/
remove_marked_cache_entries(index, 1);
/*
* No need for STABLE_QSORT -- cmp_cache_name_compare sorts primarily
* on filename and secondarily on stage, and (name, stage #) are a
* unique tuple.
*/
QSORT(index->cache, index->cache_nr, cmp_cache_name_compare);
return errs;
}
static void print_submodule_conflict_suggestion(struct string_list *csub) {
struct string_list_item *item;
struct strbuf msg = STRBUF_INIT;
struct strbuf tmp = STRBUF_INIT;
struct strbuf subs = STRBUF_INIT;
if (!csub->nr)
return;
strbuf_add_separated_string_list(&subs, " ", csub);
for_each_string_list_item(item, csub) {
struct conflicted_submodule_item *util = item->util;
/*
* NEEDSWORK: The steps to resolve these errors deserve a more
* detailed explanation than what is currently printed below.
*/
if (util->flag == CONFLICT_SUBMODULE_NOT_INITIALIZED ||
util->flag == CONFLICT_SUBMODULE_HISTORY_NOT_AVAILABLE)
continue;
/*
* TRANSLATORS: This is a line of advice to resolve a merge
* conflict in a submodule. The first argument is the submodule
* name, and the second argument is the abbreviated id of the
* commit that needs to be merged. For example:
* - go to submodule (mysubmodule), and either merge commit abc1234"
*/
strbuf_addf(&tmp, _(" - go to submodule (%s), and either merge commit %s\n"
" or update to an existing commit which has merged those changes\n"),
item->string, util->abbrev);
}
/*
* TRANSLATORS: This is a detailed message for resolving submodule
* conflicts. The first argument is string containing one step per
* submodule. The second is a space-separated list of submodule names.
*/
strbuf_addf(&msg,
_("Recursive merging with submodules currently only supports trivial cases.\n"
"Please manually handle the merging of each conflicted submodule.\n"
"This can be accomplished with the following steps:\n"
"%s"
" - come back to superproject and run:\n\n"
" git add %s\n\n"
" to record the above merge or update\n"
" - resolve any other conflicts in the superproject\n"
" - commit the resulting index in the superproject\n"),
tmp.buf, subs.buf);
advise_if_enabled(ADVICE_SUBMODULE_MERGE_CONFLICT, "%s", msg.buf);
strbuf_release(&subs);
strbuf_release(&tmp);
strbuf_release(&msg);
}
void merge_display_update_messages(struct merge_options *opt,
int detailed,
struct merge_result *result)
{
struct merge_options_internal *opti = result->priv;
struct hashmap_iter iter;
struct strmap_entry *e;
struct string_list olist = STRING_LIST_INIT_NODUP;
FILE *o = stdout;
if (opt->record_conflict_msgs_as_headers)
BUG("Either display conflict messages or record them as headers, not both");
trace2_region_enter("merge", "display messages", opt->repo);
/* Hack to pre-allocate olist to the desired size */
ALLOC_GROW(olist.items, strmap_get_size(&opti->conflicts),
olist.alloc);
/* Put every entry from output into olist, then sort */
strmap_for_each_entry(&opti->conflicts, &iter, e) {
string_list_append(&olist, e->key)->util = e->value;
}
string_list_sort(&olist);
/* Print to stderr if we hit errors rather than just conflicts */
if (result->clean < 0)
o = stderr;
/* Iterate over the items, printing them */
for (int path_nr = 0; path_nr < olist.nr; ++path_nr) {
struct string_list *conflicts = olist.items[path_nr].util;
for (int i = 0; i < conflicts->nr; i++) {
struct logical_conflict_info *info =
conflicts->items[i].util;
/* On failure, ignore regular conflict types */
if (result->clean < 0 &&
info->type < NB_REGULAR_CONFLICT_TYPES)
continue;
if (detailed) {
fprintf(o, "%lu", (unsigned long)info->paths.nr);
fputc('\0', o);
for (int n = 0; n < info->paths.nr; n++) {
fputs(info->paths.v[n], o);
fputc('\0', o);
}
fputs(type_short_descriptions[info->type], o);
fputc('\0', o);
}
fputs(conflicts->items[i].string, o);
fputc('\n', o);
if (detailed)
fputc('\0', o);
}
}
string_list_clear(&olist, 0);
if (result->clean >= 0)
print_submodule_conflict_suggestion(&opti->conflicted_submodules);
/* Also include needed rename limit adjustment now */
diff_warn_rename_limit("merge.renamelimit",
opti->renames.needed_limit, 0);
trace2_region_leave("merge", "display messages", opt->repo);
}
void merge_get_conflicted_files(struct merge_result *result,
struct string_list *conflicted_files)
{
struct hashmap_iter iter;
struct strmap_entry *e;
struct merge_options_internal *opti = result->priv;
strmap_for_each_entry(&opti->conflicted, &iter, e) {
const char *path = e->key;
struct conflict_info *ci = e->value;
int i;
VERIFY_CI(ci);
for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
struct stage_info *si;
if (!(ci->filemask & (1ul << i)))
continue;
si = xmalloc(sizeof(*si));
si->stage = i+1;
si->mode = ci->stages[i].mode;
oidcpy(&si->oid, &ci->stages[i].oid);
string_list_append(conflicted_files, path)->util = si;
}
}
/* string_list_sort() uses a stable sort, so we're good */
string_list_sort(conflicted_files);
}
void merge_switch_to_result(struct merge_options *opt,
struct tree *head,
struct merge_result *result,
int update_worktree_and_index,
int display_update_msgs)
{
assert(opt->priv == NULL);
if (result->clean >= 0 && update_worktree_and_index) {
trace2_region_enter("merge", "checkout", opt->repo);
if (checkout(opt, head, result->tree)) {
/* failure to function */
result->clean = -1;
merge_finalize(opt, result);
trace2_region_leave("merge", "checkout", opt->repo);
return;
}
trace2_region_leave("merge", "checkout", opt->repo);
trace2_region_enter("merge", "record_conflicted", opt->repo);
opt->priv = result->priv;
if (record_conflicted_index_entries(opt)) {
/* failure to function */
opt->priv = NULL;
result->clean = -1;
merge_finalize(opt, result);
trace2_region_leave("merge", "record_conflicted",
opt->repo);
return;
}
opt->priv = NULL;
trace2_region_leave("merge", "record_conflicted", opt->repo);
trace2_region_enter("merge", "write_auto_merge", opt->repo);
if (refs_update_ref(get_main_ref_store(opt->repo), "", "AUTO_MERGE",
&result->tree->object.oid, NULL, REF_NO_DEREF,
UPDATE_REFS_MSG_ON_ERR)) {
/* failure to function */
opt->priv = NULL;
result->clean = -1;
merge_finalize(opt, result);
trace2_region_leave("merge", "write_auto_merge",
opt->repo);
return;
}
trace2_region_leave("merge", "write_auto_merge", opt->repo);
}
if (display_update_msgs)
merge_display_update_messages(opt, /* detailed */ 0, result);
merge_finalize(opt, result);
}
void merge_finalize(struct merge_options *opt,
struct merge_result *result)
{
if (opt->renormalize)
git_attr_set_direction(GIT_ATTR_CHECKIN);
assert(opt->priv == NULL);
if (result->priv) {
clear_or_reinit_internal_opts(result->priv, 0);
FREE_AND_NULL(result->priv);
}
}
/*** Function Grouping: helper functions for merge_incore_*() ***/
static struct tree *shift_tree_object(struct repository *repo,
struct tree *one, struct tree *two,
const char *subtree_shift)
{
struct object_id shifted;
if (!*subtree_shift) {
shift_tree(repo, &one->object.oid, &two->object.oid, &shifted, 0);
} else {
shift_tree_by(repo, &one->object.oid, &two->object.oid, &shifted,
subtree_shift);
}
if (oideq(&two->object.oid, &shifted))
return two;
return lookup_tree(repo, &shifted);
}
static inline void set_commit_tree(struct commit *c, struct tree *t)
{
c->maybe_tree = t;
}
static struct commit *make_virtual_commit(struct repository *repo,
struct tree *tree,
const char *comment)
{
struct commit *commit = alloc_commit_node(repo);
set_merge_remote_desc(commit, comment, (struct object *)commit);
set_commit_tree(commit, tree);
commit->object.parsed = 1;
return commit;
}
static void merge_start(struct merge_options *opt, struct merge_result *result)
{
struct rename_info *renames;
int i;
struct mem_pool *pool = NULL;
/* Sanity checks on opt */
trace2_region_enter("merge", "sanity checks", opt->repo);
assert(opt->repo);
assert(opt->branch1 && opt->branch2);
assert(opt->detect_directory_renames >= MERGE_DIRECTORY_RENAMES_NONE &&
opt->detect_directory_renames <= MERGE_DIRECTORY_RENAMES_TRUE);
assert(opt->rename_limit >= -1);
assert(opt->rename_score >= 0 && opt->rename_score <= MAX_SCORE);
assert(opt->show_rename_progress >= 0 && opt->show_rename_progress <= 1);
assert(opt->xdl_opts >= 0);
assert(opt->recursive_variant >= MERGE_VARIANT_NORMAL &&
opt->recursive_variant <= MERGE_VARIANT_THEIRS);
if (opt->msg_header_prefix)
assert(opt->record_conflict_msgs_as_headers);
/*
* detect_renames, verbosity, buffer_output, and obuf are ignored
* fields that were used by "recursive" rather than "ort" -- but
* sanity check them anyway.
*/
assert(opt->detect_renames >= -1 &&
opt->detect_renames <= DIFF_DETECT_COPY);
assert(opt->verbosity >= 0 && opt->verbosity <= 5);
assert(opt->buffer_output <= 2);
assert(opt->obuf.len == 0);
assert(opt->priv == NULL);
if (result->_properly_initialized != 0 &&
result->_properly_initialized != RESULT_INITIALIZED)
BUG("struct merge_result passed to merge_incore_*recursive() must be zeroed or filled with values from a previous run");
assert(!!result->priv == !!result->_properly_initialized);
if (result->priv) {
opt->priv = result->priv;
result->priv = NULL;
/*
* opt->priv non-NULL means we had results from a previous
* run; do a few sanity checks that user didn't mess with
* it in an obvious fashion.
*/
assert(opt->priv->call_depth == 0);
assert(!opt->priv->toplevel_dir ||
0 == strlen(opt->priv->toplevel_dir));
}
trace2_region_leave("merge", "sanity checks", opt->repo);
/* Default to histogram diff. Actually, just hardcode it...for now. */
opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF);
/* Handle attr direction stuff for renormalization */
if (opt->renormalize)
git_attr_set_direction(GIT_ATTR_CHECKOUT);
/* Initialization of opt->priv, our internal merge data */
trace2_region_enter("merge", "allocate/init", opt->repo);
if (opt->priv) {
clear_or_reinit_internal_opts(opt->priv, 1);
string_list_init_nodup(&opt->priv->conflicted_submodules);
trace2_region_leave("merge", "allocate/init", opt->repo);
return;
}
opt->priv = xcalloc(1, sizeof(*opt->priv));
/* Initialization of various renames fields */
renames = &opt->priv->renames;
mem_pool_init(&opt->priv->pool, 0);
pool = &opt->priv->pool;
for (i = MERGE_SIDE1; i <= MERGE_SIDE2; i++) {
strintmap_init_with_options(&renames->dirs_removed[i],
NOT_RELEVANT, pool, 0);
strmap_init_with_options(&renames->dir_rename_count[i],
NULL, 1);
strmap_init_with_options(&renames->dir_renames[i],
NULL, 0);
/*
* relevant_sources uses -1 for the default, because we need
* to be able to distinguish not-in-strintmap from valid
* relevant_source values from enum file_rename_relevance.
* In particular, possibly_cache_new_pair() expects a negative
* value for not-found entries.
*/
strintmap_init_with_options(&renames->relevant_sources[i],
-1 /* explicitly invalid */,
pool, 0);
strmap_init_with_options(&renames->cached_pairs[i],
NULL, 1);
strset_init_with_options(&renames->cached_irrelevant[i],
NULL, 1);
strset_init_with_options(&renames->cached_target_names[i],
NULL, 0);
}
for (i = MERGE_SIDE1; i <= MERGE_SIDE2; i++) {
strintmap_init_with_options(&renames->deferred[i].possible_trivial_merges,
0, pool, 0);
strset_init_with_options(&renames->deferred[i].target_dirs,
pool, 1);
renames->deferred[i].trivial_merges_okay = 1; /* 1 == maybe */
}
/*
* Although we initialize opt->priv->paths with strdup_strings=0,
* that's just to avoid making yet another copy of an allocated
* string. Putting the entry into paths means we are taking
* ownership, so we will later free it.
*
* In contrast, conflicted just has a subset of keys from paths, so
* we don't want to free those (it'd be a duplicate free).
*/
strmap_init_with_options(&opt->priv->paths, pool, 0);
strmap_init_with_options(&opt->priv->conflicted, pool, 0);
/*
* keys & string_lists in conflicts will sometimes need to outlive
* "paths", so it will have a copy of relevant keys. It's probably
* a small subset of the overall paths that have special output.
*/
strmap_init(&opt->priv->conflicts);
trace2_region_leave("merge", "allocate/init", opt->repo);
}
static void merge_check_renames_reusable(struct merge_result *result,
struct tree *merge_base,
struct tree *side1,
struct tree *side2)
{
struct rename_info *renames;
struct tree **merge_trees;
struct merge_options_internal *opti = result->priv;
if (!opti)
return;
renames = &opti->renames;
merge_trees = renames->merge_trees;
/*
* Handle case where previous merge operation did not want cache to
* take effect, e.g. because rename/rename(1to1) makes it invalid.
*/
if (!merge_trees[0]) {
assert(!merge_trees[0] && !merge_trees[1] && !merge_trees[2]);
renames->cached_pairs_valid_side = 0; /* neither side valid */
return;
}
/*
* Handle other cases; note that merge_trees[0..2] will only
* be NULL if opti is, or if all three were manually set to
* NULL by e.g. rename/rename(1to1) handling.
*/
assert(merge_trees[0] && merge_trees[1] && merge_trees[2]);
/* Check if we meet a condition for re-using cached_pairs */
if (oideq(&merge_base->object.oid, &merge_trees[2]->object.oid) &&
oideq(&side1->object.oid, &result->tree->object.oid))
renames->cached_pairs_valid_side = MERGE_SIDE1;
else if (oideq(&merge_base->object.oid, &merge_trees[1]->object.oid) &&
oideq(&side2->object.oid, &result->tree->object.oid))
renames->cached_pairs_valid_side = MERGE_SIDE2;
else
renames->cached_pairs_valid_side = 0; /* neither side valid */
}
/*** Function Grouping: merge_incore_*() and their internal variants ***/
static void move_opt_priv_to_result_priv(struct merge_options *opt,
struct merge_result *result)
{
/*
* opt->priv and result->priv are a bit weird. opt->priv contains
* information that we can re-use in subsequent merge operations to
* enable our cached renames optimization. The best way to provide
* that to subsequent merges is putting it in result->priv.
* However, putting it directly there would mean retrofitting lots
* of functions in this file to also take a merge_result pointer,
* which is ugly and annoying. So, we just make sure at the end of
* the merge (the outer merge if there are internal recursive ones)
* to move it.
*/
assert(opt->priv && !result->priv);
result->priv = opt->priv;
result->_properly_initialized = RESULT_INITIALIZED;
opt->priv = NULL;
}
/*
* Originally from merge_trees_internal(); heavily adapted, though.
*/
static void merge_ort_nonrecursive_internal(struct merge_options *opt,
struct tree *merge_base,
struct tree *side1,
struct tree *side2,
struct merge_result *result)
{
struct object_id working_tree_oid;
if (opt->subtree_shift) {
side2 = shift_tree_object(opt->repo, side1, side2,
opt->subtree_shift);
merge_base = shift_tree_object(opt->repo, side1, merge_base,
opt->subtree_shift);
}
redo:
trace2_region_enter("merge", "collect_merge_info", opt->repo);
if (collect_merge_info(opt, merge_base, side1, side2) != 0) {
/*
* TRANSLATORS: The %s arguments are: 1) tree hash of a merge
* base, and 2-3) the trees for the two trees we're merging.
*/
error(_("collecting merge info failed for trees %s, %s, %s"),
oid_to_hex(&merge_base->object.oid),
oid_to_hex(&side1->object.oid),
oid_to_hex(&side2->object.oid));
result->clean = -1;
move_opt_priv_to_result_priv(opt, result);
return;
}
trace2_region_leave("merge", "collect_merge_info", opt->repo);
trace2_region_enter("merge", "renames", opt->repo);
result->clean = detect_and_process_renames(opt);
trace2_region_leave("merge", "renames", opt->repo);
if (opt->priv->renames.redo_after_renames == 2) {
trace2_region_enter("merge", "reset_maps", opt->repo);
clear_or_reinit_internal_opts(opt->priv, 1);
trace2_region_leave("merge", "reset_maps", opt->repo);
goto redo;
}
trace2_region_enter("merge", "process_entries", opt->repo);
if (process_entries(opt, &working_tree_oid) < 0)
result->clean = -1;
trace2_region_leave("merge", "process_entries", opt->repo);
/* Set return values */
result->path_messages = &opt->priv->conflicts;
if (result->clean >= 0) {
result->tree = parse_tree_indirect(&working_tree_oid);
if (!result->tree)
die(_("unable to read tree (%s)"),
oid_to_hex(&working_tree_oid));
/* existence of conflicted entries implies unclean */
result->clean &= strmap_empty(&opt->priv->conflicted);
}
if (!opt->priv->call_depth || result->clean < 0)
move_opt_priv_to_result_priv(opt, result);
}
/*
* Originally from merge_recursive_internal(); somewhat adapted, though.
*/
static void merge_ort_internal(struct merge_options *opt,
const struct commit_list *_merge_bases,
struct commit *h1,
struct commit *h2,
struct merge_result *result)
{
struct commit_list *merge_bases = copy_commit_list(_merge_bases);
struct commit *next;
struct commit *merged_merge_bases;
const char *ancestor_name;
struct strbuf merge_base_abbrev = STRBUF_INIT;
if (!merge_bases) {
if (repo_get_merge_bases(the_repository, h1, h2,
&merge_bases) < 0) {
result->clean = -1;
goto out;
}
/* See merge-ort.h:merge_incore_recursive() declaration NOTE */
merge_bases = reverse_commit_list(merge_bases);
}
merged_merge_bases = pop_commit(&merge_bases);
if (!merged_merge_bases) {
/* if there is no common ancestor, use an empty tree */
struct tree *tree;
tree = lookup_tree(opt->repo, opt->repo->hash_algo->empty_tree);
merged_merge_bases = make_virtual_commit(opt->repo, tree,
"ancestor");
ancestor_name = "empty tree";
} else if (merge_bases) {
ancestor_name = "merged common ancestors";
} else {
strbuf_add_unique_abbrev(&merge_base_abbrev,
&merged_merge_bases->object.oid,
DEFAULT_ABBREV);
ancestor_name = merge_base_abbrev.buf;
}
for (next = pop_commit(&merge_bases); next;
next = pop_commit(&merge_bases)) {
const char *saved_b1, *saved_b2;
struct commit *prev = merged_merge_bases;
opt->priv->call_depth++;
/*
* When the merge fails, the result contains files
* with conflict markers. The cleanness flag is
* ignored (unless indicating an error), it was never
* actually used, as result of merge_trees has always
* overwritten it: the committed "conflicts" were
* already resolved.
*/
saved_b1 = opt->branch1;
saved_b2 = opt->branch2;
opt->branch1 = "Temporary merge branch 1";
opt->branch2 = "Temporary merge branch 2";
merge_ort_internal(opt, NULL, prev, next, result);
if (result->clean < 0)
goto out;
opt->branch1 = saved_b1;
opt->branch2 = saved_b2;
opt->priv->call_depth--;
merged_merge_bases = make_virtual_commit(opt->repo,
result->tree,
"merged tree");
commit_list_insert(prev, &merged_merge_bases->parents);
commit_list_insert(next, &merged_merge_bases->parents->next);
clear_or_reinit_internal_opts(opt->priv, 1);
}
opt->ancestor = ancestor_name;
merge_ort_nonrecursive_internal(opt,
repo_get_commit_tree(opt->repo,
merged_merge_bases),
repo_get_commit_tree(opt->repo, h1),
repo_get_commit_tree(opt->repo, h2),
result);
strbuf_release(&merge_base_abbrev);
opt->ancestor = NULL; /* avoid accidental re-use of opt->ancestor */
out:
free_commit_list(merge_bases);
}
void merge_incore_nonrecursive(struct merge_options *opt,
struct tree *merge_base,
struct tree *side1,
struct tree *side2,
struct merge_result *result)
{
trace2_region_enter("merge", "incore_nonrecursive", opt->repo);
trace2_region_enter("merge", "merge_start", opt->repo);
assert(opt->ancestor != NULL);
merge_check_renames_reusable(result, merge_base, side1, side2);
merge_start(opt, result);
/*
* Record the trees used in this merge, so if there's a next merge in
* a cherry-pick or rebase sequence it might be able to take advantage
* of the cached_pairs in that next merge.
*/
opt->priv->renames.merge_trees[0] = merge_base;
opt->priv->renames.merge_trees[1] = side1;
opt->priv->renames.merge_trees[2] = side2;
trace2_region_leave("merge", "merge_start", opt->repo);
merge_ort_nonrecursive_internal(opt, merge_base, side1, side2, result);
trace2_region_leave("merge", "incore_nonrecursive", opt->repo);
}
void merge_incore_recursive(struct merge_options *opt,
const struct commit_list *merge_bases,
struct commit *side1,
struct commit *side2,
struct merge_result *result)
{
trace2_region_enter("merge", "incore_recursive", opt->repo);
/* We set the ancestor label based on the merge_bases */
assert(opt->ancestor == NULL);
trace2_region_enter("merge", "merge_start", opt->repo);
merge_start(opt, result);
trace2_region_leave("merge", "merge_start", opt->repo);
merge_ort_internal(opt, merge_bases, side1, side2, result);
trace2_region_leave("merge", "incore_recursive", opt->repo);
}
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