mirror of
https://github.com/git/git.git
synced 2024-05-28 02:16:29 +02:00
712516bcac
Keeping track of the flag bits is proving more trouble than it's worth. Instead, use a pointer to an options struct like most similar APIs do. Callers with no special requests can pass NULL to request the default options. Cc: Bert Wesarg <bert.wesarg@googlemail.com> Cc: Avery Pennarun <apenwarr@gmail.com> Helped-by: Justin Frankel <justin@cockos.com> Helped-by: Bert Wesarg <bert.wesarg@googlemail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
105 lines
3.3 KiB
Plaintext
105 lines
3.3 KiB
Plaintext
merge API
|
|
=========
|
|
|
|
The merge API helps a program to reconcile two competing sets of
|
|
improvements to some files (e.g., unregistered changes from the work
|
|
tree versus changes involved in switching to a new branch), reporting
|
|
conflicts if found. The library called through this API is
|
|
responsible for a few things.
|
|
|
|
* determining which trees to merge (recursive ancestor consolidation);
|
|
|
|
* lining up corresponding files in the trees to be merged (rename
|
|
detection, subtree shifting), reporting edge cases like add/add
|
|
and rename/rename conflicts to the user;
|
|
|
|
* performing a three-way merge of corresponding files, taking
|
|
path-specific merge drivers (specified in `.gitattributes`)
|
|
into account.
|
|
|
|
Data structures
|
|
---------------
|
|
|
|
* `mmbuffer_t`, `mmfile_t`
|
|
|
|
These store data usable for use by the xdiff backend, for writing and
|
|
for reading, respectively. See `xdiff/xdiff.h` for the definitions
|
|
and `diff.c` for examples.
|
|
|
|
* `struct ll_merge_options`
|
|
|
|
This describes the set of options the calling program wants to affect
|
|
the operation of a low-level (single file) merge. Some options:
|
|
|
|
`virtual_ancestor`::
|
|
Behave as though this were part of a merge between common
|
|
ancestors in a recursive merge.
|
|
If a helper program is specified by the
|
|
`[merge "<driver>"] recursive` configuration, it will
|
|
be used (see linkgit:gitattributes[5]).
|
|
|
|
`variant`::
|
|
Resolve local conflicts automatically in favor
|
|
of one side or the other (as in 'git merge-file'
|
|
`--ours`/`--theirs`/`--union`). Can be `0`,
|
|
`XDL_MERGE_FAVOR_OURS`, `XDL_MERGE_FAVOR_THEIRS`, or
|
|
`XDL_MERGE_FAVOR_UNION`.
|
|
|
|
`renormalize`::
|
|
Resmudge and clean the "base", "theirs" and "ours" files
|
|
before merging. Use this when the merge is likely to have
|
|
overlapped with a change in smudge/clean or end-of-line
|
|
normalization rules.
|
|
|
|
Low-level (single file) merge
|
|
-----------------------------
|
|
|
|
`ll_merge`::
|
|
|
|
Perform a three-way single-file merge in core. This is
|
|
a thin wrapper around `xdl_merge` that takes the path and
|
|
any merge backend specified in `.gitattributes` or
|
|
`.git/info/attributes` into account. Returns 0 for a
|
|
clean merge.
|
|
|
|
Calling sequence:
|
|
|
|
* Prepare a `struct ll_merge_options` to record options.
|
|
If you have no special requests, skip this and pass `NULL`
|
|
as the `opts` parameter to use the default options.
|
|
|
|
* Allocate an mmbuffer_t variable for the result.
|
|
|
|
* Allocate and fill variables with the file's original content
|
|
and two modified versions (using `read_mmfile`, for example).
|
|
|
|
* Call `ll_merge()`.
|
|
|
|
* Read the merged content from `result_buf.ptr` and `result_buf.size`.
|
|
|
|
* Release buffers when finished. A simple
|
|
`free(ancestor.ptr); free(ours.ptr); free(theirs.ptr);
|
|
free(result_buf.ptr);` will do.
|
|
|
|
If the modifications do not merge cleanly, `ll_merge` will return a
|
|
nonzero value and `result_buf` will generally include a description of
|
|
the conflict bracketed by markers such as the traditional `<<<<<<<`
|
|
and `>>>>>>>`.
|
|
|
|
The `ancestor_label`, `our_label`, and `their_label` parameters are
|
|
used to label the different sides of a conflict if the merge driver
|
|
supports this.
|
|
|
|
Everything else
|
|
---------------
|
|
|
|
Talk about <merge-recursive.h> and merge_file():
|
|
|
|
- merge_trees() to merge with rename detection
|
|
- merge_recursive() for ancestor consolidation
|
|
- try_merge_command() for other strategies
|
|
- conflict format
|
|
- merge options
|
|
|
|
(Daniel, Miklos, Stephan, JC)
|