A long term (but rather minor) pet-peeve of mine was the name
ll-merge.[ch]. I thought it made it harder to realize what stuff was
related to merging when I was working on the merge machinery and trying
to improve it.
Further, back in d1cbe1e6d8 ("hash-ll.h: split out of hash.h to remove
dependency on repository.h", 2023-04-22), we have split the portions of
hash.h that do not depend upon repository.h into a "hash-ll.h" (due to
the recommendation to use "ll" for "low-level" in its name[1], but which
I used as a suffix precisely because of my distaste for "ll-merge").
When we discussed adding additional "*-ll.h" files, a request was made
that we use "ll" consistently as either a prefix or a suffix. Since it
is already in use as both a prefix and a suffix, the only way to do so
is to rename some files.
Besides my distaste for the ll-merge.[ch] name, let me also note that
the files
ll-fsmonitor.h, ll-hash.h, ll-merge.h, ll-object-store.h, ll-read-cache.h
would have essentially nothing to do with each other and make no sense
to group. But giving them the common "ll-" prefix would group them. Using
"-ll" as a suffix thus seems just much more logical to me. Rename
ll-merge.[ch] to merge-ll.[ch] to achieve this consistency, and to
ensure we get a more logical grouping of files.
[1] https://lore.kernel.org/git/kl6lsfcu1g8w.fsf@chooglen-macbookpro.roam.corp.google.com/
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since some callers may want to send warning messages to somewhere other
than stdout/stderr, stop printing "warning: Cannot merge binary files"
from ll-merge and instead modify the return status of ll_merge() to
indicate when a merge of binary files has occurred. Message printing
probably does not belong in a "low-level merge" anyway.
This commit continues printing the message as-is, just from the callers
instead of within ll_merge(). Future changes will start handling the
message differently in the merge-ort codepath.
There was one special case here: the callers in rerere.c do NOT check
for and print such a message; since those code paths explicitly skip
over binary files, there is no reason to check for a return status of
LL_MERGE_BINARY_CONFLICT or print the related message.
Note that my methodology included first modifying ll_merge() to return
a struct, so that the compiler would catch all the callers for me and
ensure I had modified all of them. After modifying all of them, I then
changed the struct to an enum.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the related documentation from Documentation/technical/api-merge.txt
to ll-merge.h as it's easier for the developers to find the usage
information beside the code instead of looking for it in another doc file.
Only the ll-merge related doc is removed from
documentation/technical/api-merge.txt because this information will be
redundant and it'll be hard to keep it up to date and synchronized with
the documentation in ll-merge.h.
Signed-off-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When applying multiple patches with git am, or when rebasing using the
am backend, it's possible that one of our patches has updated a
gitattributes file. Currently, we cache this information, so if a
file in a subsequent patch has attributes applied, the file will be
written out with the attributes in place as of the time we started the
rebase or am operation, not with the attributes applied by the previous
patch. This problem does not occur when using the -m or -i flags to
rebase.
To ensure we write the correct data into the working tree, expire the
cache after each patch that touches a path ending in ".gitattributes".
Since we load these attributes in multiple separate files, we must
expire them accordingly.
Verify that both the am and rebase code paths work correctly, including
the conflict marker size with am -3.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Later patches in this series will modify file collision conflict
handling (e.g. from rename/add and rename/rename(2to1) conflicts) so
that multiply nested conflict markers can arise even before considering
conflicts in the virtual merge base. Including the virtual merge base
will provide a way to get triply (or higher) nested conflict markers.
This new way to get nested conflict markers will force the need for a
more general mechanism to extend the length of conflict markers in order
to differentiate between different nestings.
Along with this change to conflict marker length handling, we want to
make sure that we don't regress handling for other types of conflicts
with nested conflict markers. Add a more involved testcase using
merge.conflictstyle=diff3, where not only does the virtual merge base
contain conflicts, but its virtual merge base does as well (i.e. a case
with triply nested conflict markers). While there are multiple
reasonable ways to handle nested conflict markers in the virtual merge
base for this type of situation, the easiest approach that dovetails
well with the new needs for the file collision conflict handling is to
require that the length of the conflict markers increase with each
subsequent nesting.
Subsequent patches which change the rename/add and rename/rename(2to1)
conflict handling will modify the extra_marker_size flag appropriately
for their new needs.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
I looped over the toplevel header files, creating a temporary two-line C
program for each consisting of
#include "git-compat-util.h"
#include $HEADER
This patch is the result of manually fixing errors in compiling those
tiny programs.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the merge-recursive strategy a --patience option to use the
"patience diff" algorithm, which tends to improve results when
cherry-picking a patch that reorders functions at the same time as
refactoring them.
To support this, struct merge_options and ll_merge_options gain an
xdl_opts member, so programs can use arbitrary xdiff flags (think
"XDF_IGNORE_WHITESPACE") in a git-aware merge.
git merge and git rebase can be passed the -Xpatience option to
use this.
[jn: split from --ignore-space patch; with documentation]
Signed-off-by: Justin Frankel <justin@cockos.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Add a “renormalize” bit to the ll-merge options word so callers can
decide on a case-by-case basis whether the merge is likely to have
overlapped with a change in smudge/clean rules.
This reveals a few commands that have not been taking that situation
into account, though it does not fix them.
No functional change intended.
Cc: Eyvind Bernhardsen <eyvind.bernhardsen@gmail.com>
Improved-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ll_merge() takes its options in a flag word, which has a few
advantages:
- options flags can be cheaply passed around in registers, while
an option struct passed by pointer cannot;
- callers can easily pass 0 without trouble for no options,
while an option struct passed by value would not allow that.
The downside is that code to populate and access the flag word can be
somewhat opaque. Mitigate that with a few macros.
Cc: Avery Pennarun <apenwarr@gmail.com>
Cc: Bert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commands using the ll_merge() function will present conflict hunks
imitating ‘diff3 -m’ output if the merge.conflictstyle configuration
option is set appropriately. Unlike ‘diff3 -m’, the output does not
include a label for the merge base on the ||||||| line of the output,
and some tools misparse the conflict hunks without that.
Add a new ancestor_label parameter to ll_merge() to give callers the
power to rectify this situation. If ancestor_label is NULL, the output
format is unchanged. All callers pass NULL for now.
Requested-by: Stefan Monnier <monnier@iro.umontreal.ca>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jc/conflict-marker-size:
rerere: honor conflict-marker-size attribute
rerere: prepare for customizable conflict marker length
conflict-marker-size: new attribute
rerere: use ll_merge() instead of using xdl_merge()
merge-tree: use ll_merge() not xdl_merge()
xdl_merge(): allow passing down marker_size in xmparam_t
xdl_merge(): introduce xmparam_t for merge specific parameters
git_attr(): fix function signature
Conflicts:
builtin-merge-file.c
ll-merge.c
xdiff/xdiff.h
xdiff/xmerge.c
Teach "-X <option>" command line argument to "git merge" that is passed to
strategy implementations. "ours" and "theirs" autoresolution introduced
by the previous commit can be asked to the recursive strategy.
Signed-off-by: Avery Pennarun <apenwarr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This moves low-level merge functions out of merge-recursive.c and
places them in a new separate file, ll-merge.c
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren
Heba Waly
brian m. carlson
Junio C Hamano
Nguyễn Thái Ngọc Duy
Justin Frankel
Jonathan Nieder
Avery Pennarun