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/*
* Low level 3-way in-core file merge.
*/
#ifndef LL_MERGE_H
#define LL_MERGE_H
#include "xdiff/xdiff.h"
/**
*
* 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.
*/
struct index_state;
/**
* This describes the set of options the calling program wants to affect
* the operation of a low-level (single file) merge.
*/
struct ll_merge_options {
/**
* Behave as though this were part of a merge between common ancestors in
* a recursive merge (merges of binary files may need to be handled
* differently in such cases, for example). If a helper program is
* specified by the `[merge "<driver>"] recursive` configuration, it will
* be used.
*/
unsigned virtual_ancestor : 1;
/**
* 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`.
*/
unsigned variant : 2;
/**
* 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.
*/
unsigned renormalize : 1;
/**
* Increase the length of conflict markers so that nested conflicts
 * can be differentiated.
*/
unsigned extra_marker_size;
/* Override the global conflict style. */
int conflict_style;
/* Extra xpparam_t flags as defined in xdiff/xdiff.h. */
long xdl_opts;
};
#define LL_MERGE_OPTIONS_INIT { .conflict_style = -1 }
enum ll_merge_result {
LL_MERGE_ERROR = -1,
LL_MERGE_OK = 0,
LL_MERGE_CONFLICT,
LL_MERGE_BINARY_CONFLICT,
};
/**
* 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.
*/
enum ll_merge_result ll_merge(mmbuffer_t *result_buf,
const char *path,
mmfile_t *ancestor, const char *ancestor_label,
mmfile_t *ours, const char *our_label,
mmfile_t *theirs, const char *their_label,
struct index_state *istate,
const struct ll_merge_options *opts);
int ll_merge_marker_size(struct index_state *istate, const char *path);
void reset_merge_attributes(void);
#endif