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Diffstat (limited to 'Documentation/technical/api-merge.txt')
| -rw-r--r-- | Documentation/technical/api-merge.txt | 71 |
1 files changed, 51 insertions, 20 deletions
diff --git a/Documentation/technical/api-merge.txt b/Documentation/technical/api-merge.txt index a7e050bb7a..9dc1bed768 100644 --- a/Documentation/technical/api-merge.txt +++ b/Documentation/technical/api-merge.txt @@ -17,6 +17,40 @@ responsible for a few things. 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 ----------------------------- @@ -28,15 +62,24 @@ Low-level (single file) merge `.git/info/attributes` into account. Returns 0 for a clean merge. -The caller: +Calling sequence: -1. allocates an mmbuffer_t variable for the result; -2. allocates and fills variables with the file's original content - and two modified versions (using `read_mmfile`, for example); -3. calls ll_merge(); -4. reads the output from result_buf.ptr and result_buf.size; -5. releases buffers when finished (free(ancestor.ptr); free(ours.ptr); - free(theirs.ptr); free(result_buf.ptr);). +* 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 @@ -47,18 +90,6 @@ 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. -The `flag` parameter is a bitfield: - - - The `LL_OPT_VIRTUAL_ANCESTOR` bit indicates whether this is an - internal merge to consolidate ancestors for a recursive merge. - - - The `LL_OPT_FAVOR_MASK` bits allow local conflicts to be automatically - resolved in favor of one side or the other (as in 'git merge-file' - `--ours`/`--theirs`/`--union`). - They can be populated by `create_ll_flag`, whose argument can be - `XDL_MERGE_FAVOR_OURS`, `XDL_MERGE_FAVOR_THEIRS`, or - `XDL_MERGE_FAVOR_UNION`. - Everything else --------------- |