git/merge-recursive.h
Patrick Steinhardt 44ec7c575f merge: fix leaking merge bases
When calling either the recursive or the ORT merge machineries we need
to provide a list of merge bases. The ownership of that parameter is
then implicitly transferred to the callee, which is somewhat fishy.
Furthermore, that list may leak in some cases where the merge machinery
runs into an error, thus causing a memory leak.

Refactor the code such that we stop transferring ownership. Instead, the
merge machinery will now create its own local copies of the passed in
list as required if they need to modify the list. Free the list at the
callsites as required.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-11 13:15:08 -07:00

130 lines
3.8 KiB
C

#ifndef MERGE_RECURSIVE_H
#define MERGE_RECURSIVE_H
#include "strbuf.h"
struct commit;
struct commit_list;
struct object_id;
struct repository;
struct tree;
struct merge_options_internal;
struct merge_options {
struct repository *repo;
/* ref names used in console messages and conflict markers */
const char *ancestor;
const char *branch1;
const char *branch2;
/* rename related options */
int detect_renames;
enum {
MERGE_DIRECTORY_RENAMES_NONE = 0,
MERGE_DIRECTORY_RENAMES_CONFLICT = 1,
MERGE_DIRECTORY_RENAMES_TRUE = 2
} detect_directory_renames;
int rename_limit;
int rename_score;
int show_rename_progress;
/* xdiff-related options (patience, ignore whitespace, ours/theirs) */
long xdl_opts;
int conflict_style;
enum {
MERGE_VARIANT_NORMAL = 0,
MERGE_VARIANT_OURS,
MERGE_VARIANT_THEIRS
} recursive_variant;
/* console output related options */
int verbosity;
unsigned buffer_output; /* 1: output at end, 2: keep buffered */
struct strbuf obuf; /* output buffer; if buffer_output == 2, caller
* must handle and call strbuf_release */
/* miscellaneous control options */
const char *subtree_shift;
unsigned renormalize : 1;
unsigned record_conflict_msgs_as_headers : 1;
const char *msg_header_prefix;
/* internal fields used by the implementation */
struct merge_options_internal *priv;
};
void init_merge_options(struct merge_options *opt, struct repository *repo);
void copy_merge_options(struct merge_options *dst, struct merge_options *src);
void clear_merge_options(struct merge_options *opt);
/* parse the option in s and update the relevant field of opt */
int parse_merge_opt(struct merge_options *opt, const char *s);
/*
* RETURN VALUES: All the merge_* functions below return a value as follows:
* > 0 Merge was clean
* = 0 Merge had conflicts
* < 0 Merge hit an unexpected and unrecoverable problem (e.g. disk
* full) and aborted merge part-way through.
*/
/*
* rename-detecting three-way merge, no recursion.
*
* Outputs:
* - See RETURN VALUES above
* - opt->repo->index has the new index
* - new index NOT written to disk
* - The working tree is updated with results of the merge
*/
int merge_trees(struct merge_options *opt,
struct tree *head,
struct tree *merge,
struct tree *merge_base);
/*
* merge_recursive is like merge_trees() but with recursive ancestor
* consolidation.
*
* NOTE: empirically, about a decade ago it was determined that with more
* than two merge bases, optimal behavior was found when the
* merge_bases were passed in the order of oldest commit to newest
* commit. Also, merge_bases will be consumed (emptied) so make a
* copy if you need it.
*
* Outputs:
* - See RETURN VALUES above
* - *result is treated as scratch space for temporary recursive merges
* - opt->repo->index has the new index
* - new index NOT written to disk
* - The working tree is updated with results of the merge
*/
int merge_recursive(struct merge_options *opt,
struct commit *h1,
struct commit *h2,
const struct commit_list *merge_bases,
struct commit **result);
/*
* merge_recursive_generic can operate on trees instead of commits, by
* wrapping the trees into virtual commits, and calling merge_recursive().
* It also writes out the in-memory index to disk if the merge is successful.
*
* Outputs:
* - See RETURN VALUES above
* - *result is treated as scratch space for temporary recursive merges
* - opt->repo->index has the new index
* - new index also written to $GIT_INDEX_FILE on disk
* - The working tree is updated with results of the merge
*/
int merge_recursive_generic(struct merge_options *opt,
const struct object_id *head,
const struct object_id *merge,
int num_merge_bases,
const struct object_id *merge_bases,
struct commit **result);
#endif