The seventh batch
[git.git] / ll-merge.h
blobaceb1b24132306a272182556ee15003a1f0d4e08
1 /*
2 * Low level 3-way in-core file merge.
3 */
5 #ifndef LL_MERGE_H
6 #define LL_MERGE_H
8 #include "xdiff/xdiff.h"
10 /**
12 * Calling sequence:
13 * ----------------
15 * - Prepare a `struct ll_merge_options` to record options.
16 * If you have no special requests, skip this and pass `NULL`
17 * as the `opts` parameter to use the default options.
19 * - Allocate an mmbuffer_t variable for the result.
21 * - Allocate and fill variables with the file's original content
22 * and two modified versions (using `read_mmfile`, for example).
24 * - Call `ll_merge()`.
26 * - Read the merged content from `result_buf.ptr` and `result_buf.size`.
28 * - Release buffers when finished. A simple
29 * `free(ancestor.ptr); free(ours.ptr); free(theirs.ptr);
30 * free(result_buf.ptr);` will do.
32 * If the modifications do not merge cleanly, `ll_merge` will return a
33 * nonzero value and `result_buf` will generally include a description of
34 * the conflict bracketed by markers such as the traditional `<<<<<<<`
35 * and `>>>>>>>`.
37 * The `ancestor_label`, `our_label`, and `their_label` parameters are
38 * used to label the different sides of a conflict if the merge driver
39 * supports this.
43 struct index_state;
45 /**
46 * This describes the set of options the calling program wants to affect
47 * the operation of a low-level (single file) merge.
49 struct ll_merge_options {
51 /**
52 * Behave as though this were part of a merge between common ancestors in
53 * a recursive merge (merges of binary files may need to be handled
54 * differently in such cases, for example). If a helper program is
55 * specified by the `[merge "<driver>"] recursive` configuration, it will
56 * be used.
58 unsigned virtual_ancestor : 1;
60 /**
61 * Resolve local conflicts automatically in favor of one side or the other
62 * (as in 'git merge-file' `--ours`/`--theirs`/`--union`). Can be `0`,
63 * `XDL_MERGE_FAVOR_OURS`, `XDL_MERGE_FAVOR_THEIRS`,
64 * or `XDL_MERGE_FAVOR_UNION`.
66 unsigned variant : 2;
68 /**
69 * Resmudge and clean the "base", "theirs" and "ours" files before merging.
70 * Use this when the merge is likely to have overlapped with a change in
71 * smudge/clean or end-of-line normalization rules.
73 unsigned renormalize : 1;
75 /**
76 * Increase the length of conflict markers so that nested conflicts
77  * can be differentiated.
79 unsigned extra_marker_size;
81 /* Extra xpparam_t flags as defined in xdiff/xdiff.h. */
82 long xdl_opts;
85 /**
86 * Perform a three-way single-file merge in core. This is a thin wrapper
87 * around `xdl_merge` that takes the path and any merge backend specified in
88 * `.gitattributes` or `.git/info/attributes` into account.
89 * Returns 0 for a clean merge.
91 int ll_merge(mmbuffer_t *result_buf,
92 const char *path,
93 mmfile_t *ancestor, const char *ancestor_label,
94 mmfile_t *ours, const char *our_label,
95 mmfile_t *theirs, const char *their_label,
96 struct index_state *istate,
97 const struct ll_merge_options *opts);
99 int ll_merge_marker_size(struct index_state *istate, const char *path);
100 void reset_merge_attributes(void);
102 #endif