This operation has quadratic complexity, which is especially painful
on Windows, where shell scripts are *already* slow (mainly due to the
overhead of the POSIX emulation layer).
Let's reimplement this with linear complexity (using a hash map to
match the commits' subject lines) for the common case; Sadly, the
fixup/squash feature's design neglected performance considerations,
allowing arbitrary prefixes (read: `fixup! hell` will match the
commit subject `hello world`), which means that we are stuck with
quadratic performance in the worst case.
The reimplemented logic also happens to fix a bug where commented-out
lines (representing empty patches) were dropped by the previous code.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In particular on Windows, where shell scripts are even more expensive
than on MacOSX or Linux, it makes sense to move a loop that forks
Git at least once for every line in the todo list into a builtin.
Note: The original code did not try to skip unnecessary picks of root
commits but punts instead (probably --root was not considered common
enough of a use case to bother optimizing). We do the same, for now.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In particular on Windows, where shell scripts are even more expensive
than on MacOSX or Linux, it makes sense to move a loop that forks
Git at least once for every line in the todo list into a builtin.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is crucial to improve performance on Windows, as the speed is now
mostly dominated by the SHA-1 transformation (because it spawns a new
rev-parse process for *every* line, and spawning processes is pretty
slow from Git for Windows' MSYS2 Bash).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The first step of an interactive rebase is to generate the so-called "todo
script", to be stored in the state directory as "git-rebase-todo" and to
be edited by the user.
Originally, we adjusted the output of `git log <options>` using a simple
sed script. Over the course of the years, the code became more
complicated. We now use shell scripting to edit the output of `git log`
conditionally, depending whether to keep "empty" commits (i.e. commits
that do not change any files).
On platforms where shell scripting is not native, this can be a serious
drag. And it opens the door for incompatibilities between platforms when
it comes to shell scripting or to Unix-y commands.
Let's just re-implement the todo script generation in plain C, using the
revision machinery directly.
This is substantially faster, improving the speed relative to the
shell script version of the interactive rebase from 2x to 3x on Windows.
Note that the rearrange_squash() function in git-rebase--interactive
relied on the fact that we set the "format" variable to the config setting
rebase.instructionFormat. Relying on a side effect like this is no good,
hence we explicitly perform that assignment (possibly again) in
rearrange_squash().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The shell script version of the interactive rebase has a very specific
final message. Teach the sequencer to print the same.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
For the benefit of e.g. the shell prompt, the interactive rebase not
only displays the progress for the user to see, but also writes it into
the msgnum/end files in the state directory.
Teach the sequencer this new trick.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The interactive rebase keeps the user informed about its progress.
If the sequencer wants to do the grunt work of the interactive
rebase, it also needs to show that progress.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the behavior of the shell script version of the interactive
rebase, by using the `output` function defined in `git-rebase.sh`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the behavior of the shell script version of the interactive
rebase, by using the `output` function defined in `git-rebase.sh`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Instead of using the convenience function run_command_v_opt_cd_env(), we
now use the run_command() function. The former function is simply a
wrapper of the latter, trying to make it more convenient to use.
However, we already have to construct the argv and the env parameters,
and we will need even finer control e.g. over the output of the command,
so let's just stop using the convenience function.
Based on patches and suggestions by Johannes Sixt and Jeff King.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Rather than abusing a strbuf to come up with an environment block, let's
just use the argv_array structure which serves the same purpose much
better.
While at it, rename the function to reflect the fact that it does not
really care exactly what environment variables are defined in said file.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the upcoming patch, we will support rebase -i's progress
reporting. The progress skips comments but counts 'noop's.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The parsing part of a 'drop' command is almost identical to parsing a
'pick', while the operation is the same as that of a 'noop'.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The interactive rebase has the very special magic that a cherry-pick
that exits with a status different from 0 and 1 signifies a failure to
even record that a cherry-pick was started.
This can happen e.g. when a fast-forward fails because it would
overwrite untracked files.
In that case, we must reschedule the command that we thought we already
had at least started successfully.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The sequencer already has an idea about using different merge
strategies. We just piggy-back on top of that, using rebase -i's
own settings, when running the sequencer in interactive rebase mode.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Git's `rebase` command inspects the `rebase.autostash` config setting
to determine whether it should stash any uncommitted changes before
rebasing and re-apply them afterwards.
As we introduce more bits and pieces to let the sequencer act as
interactive rebase's backend, here is the part that adds support for
the autostash feature.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When continuing after a `pick` command failed, we want that commit
to show up in the rewritten-list (and its notes to be rewritten), too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When rebasing commits that have commit notes attached, the interactive
rebase rewrites those notes faithfully at the end. The sequencer must
do this, too, if it wishes to do interactive rebase's job.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
We already used the same reflog message as the scripted version of rebase
-i when finishing. With this commit, we do that also for all the commands
before that.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This makes the code DRYer, with the obvious benefit that we can enhance
the code further in a single place.
We can also reuse the functionality elsewhere by calling this new
function.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The sequencer already knew how to fast-forward instead of
cherry-picking, if possible.
We want to continue to do this, of course, but in case of the 'reword'
command, we will need to call `git commit` after fast-forwarding.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is now trivial, as all the building blocks are in place: all we need
to do is to flip the "edit" switch when committing.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When doing an interactive rebase, we want to leave a 'patch' file for
further inspection by the user (even if we never tried to actually apply
that patch, since we're cherry-picking instead).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
An interactive rebase operates on a detached HEAD (to keep the reflog
of the original branch relatively clean), and updates the branch only
at the end.
Now that the sequencer learns to perform interactive rebases, it also
needs to learn the trick to update the branch before removing the
directory containing the state of the interactive rebase.
We introduce a new head_ref variable in a wider scope than necessary at
the moment, to allow for a later patch that prints out "Successfully
rebased and updated <ref>".
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When the last command of an interactive rebase fails, the user needs to
resolve the problem and then continue the interactive rebase. Naturally,
the todo script is empty by then. So let's not complain about that!
To that end, let's move that test out of the function that parses the
todo script, and into the more high-level function read_populate_todo().
This is also necessary by now because the lower-level parse_insn_buffer()
has no idea whether we are performing an interactive rebase or not.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When a cherry-pick continues without a "todo script", the intention is
simply to pick a single commit.
However, when an interactive rebase is continued without a "todo
script", it means that the last command has been completed and that we
now need to clean up.
This commit guards the revert/cherry-pick specific steps so that they
are not executed in rebase -i mode.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When an interactive rebase is interrupted, the user may stage changes
before continuing, and we need to commit those changes in that case.
Please note that the nested "if" added to the sequencer_continue() is
not combined into a single "if" because it will be extended with an
"else" clause in a later patch in this patch series.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When the interactive rebase aborts, it writes out an author-script file
to record the author information for the current commit. As we are about
to teach the sequencer how to perform the actions behind an interactive
rebase, it needs to write those author-script files, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
For users' convenience, most rebase commands can be abbreviated, e.g.
'p' instead of 'pick' and 'x' instead of 'exec'. Let's teach the
sequencer to handle those abbreviated commands just fine.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is a huge patch, and at the same time a huge step forward to
execute the performance-critical parts of the interactive rebase in a
builtin command.
Since 'fixup' and 'squash' are not only similar, but also need to know
about each other (we want to reduce a series of fixups/squashes into a
single, final commit message edit, from the user's point of view), we
really have to implement them both at the same time.
Most of the actual work is done by the existing code path that already
handles the "pick" and the "edit" commands; We added support for other
features (e.g. to amend the commit message) in the patches leading up to
this one, yet there are still quite a few bits in this patch that simply
would not make sense as individual patches (such as: determining whether
there was anything to "fix up" in the "todo" script, etc).
In theory, it would be possible to reuse the fast-forward code path also
for the fixup and the squash code paths, but in practice this would make
the code less readable. The end result cannot be fast-forwarded anyway,
therefore let's just extend the cherry-picking code path for now.
Since the sequencer parses the entire `git-rebase-todo` script in one go,
fixup or squash commands without a preceding pick can be reported early
(in git-rebase--interactive, we could only report such errors just before
executing the fixup/squash).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the interactive rebase, commands that were successfully processed are
not simply discarded, but appended to the 'done' file instead. This is
used e.g. to display the current state to the user in the output of
`git status` or the progress.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When calling `git rebase -i -v`, the user wants to see some statistics
after the commits were rebased. Let's show some.
The strbuf we use to perform that task will be used for other things
in subsequent commits, hence it is declared and initialized in a wider
scope than strictly needed here.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The 'exec' command is a little special among rebase -i's commands, as it
does *not* have a SHA-1 as first parameter. Instead, everything after the
`exec` command is treated as command-line to execute.
Let's reuse the arg/arg_len fields of the todo_item structure (which hold
the oneline for pick/edit commands) to point to the command-line.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This patch is a straight-forward reimplementation of the `edit`
operation of the interactive rebase command.
Well, not *quite* straight-forward: when stopping, the `edit`
command wants to write the `patch` file (which is not only the
patch, but includes the commit message and author information). To
that end, this patch requires the earlier work that taught the
log-tree machinery to respect the `file` setting of
rev_info->diffopt to write to a file stream different than stdout.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The 'noop' command is probably the most boring of all rebase -i commands
to support in the sequencer.
Which makes it an excellent candidate for this first stab to add support
for rebase -i's commands to the sequencer.
For the moment, let's also treat empty lines and commented-out lines as
'noop'; We will refine that handling later in this patch series.
To make it easier to identify "classes" of todo_commands (such as:
determine whether a command is pick-like, i.e. handles a single commit),
let's enforce a certain order of said commands.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This patch introduces a new action for the sequencer. It really does not
do a whole lot of its own right now, but lays the ground work for
patches to come. The intention, of course, is to finally make the
sequencer the work horse of the interactive rebase (the original idea
behind the "sequencer" concept).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
It is actually not safe to look for a commit message by looking for the
first empty line and skipping it.
The find_commit_subject() function looks more carefully, so let's use
it. Since we are interested in the entire commit message, we re-compute
the string length after verifying that the commit subject is not empty
(in which case the entire commit message would be empty, something that
should not happen but that we want to handle gracefully).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
It is the current coding style of the Git project to write
if (...) {
...
} else {
...
}
instead of putting the closing brace and the "else" keyword on separate
lines.
Pointed out by Junio Hamano.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This was noticed while addressing Junio Hamano's concern that some
"else" operators were on separate lines than the preceding closing
brace.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This reverts commit 39784cd362.
The function had only one caller when the "remove useless" was
written, but another topic will soon make heavy use of it and more
importantly the function will return different paths depending on
the value in opts.
This function is used only once, for the removal of the
directory. It is not used for the creation of the directory nor
anywhere else.
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In contrast to "git am --abort", a sequencer abort did not check
whether the current HEAD is the one that is expected. This can lead
to loss of work (when not spotted and resolved using reflog before
the garbage collector chimes in).
This behavior is now changed by mimicking "git am --abort". The
abortion is done but HEAD is not changed when the current HEAD is
not the expected HEAD.
A new file "sequencer/abort-safety" is added to save the expected
HEAD.
The new behavior is only active when --abort is invoked on multiple
picks. The problem does not occur for the single-pick case because
it is handled differently.
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Silence a clang warning introduced by a recently graduated topic.
* js/prepare-sequencer:
sequencer: silence -Wtautological-constant-out-of-range-compare
When clang compiles sequencer.c, it complains:
sequencer.c:632:14: warning: comparison of constant 2 with
expression of type 'const enum todo_command' is always
true [-Wtautological-constant-out-of-range-compare]
if (command < ARRAY_SIZE(todo_command_strings))
This is because "command" is an enum that may only have two
values (0 and 1) and the array in question has two elements.
As it turns out, clang is actually wrong here, at least
according to its own bug tracker:
https://llvm.org/bugs/show_bug.cgi?id=16154
But it's still worth working around this, as the warning is
present with -Wall, meaning we fail compilation with "make
DEVELOPER=1".
Casting the enum to size_t sufficiently unconfuses clang. As
a bonus, it also catches any possible out-of-bounds access
if the enum takes on a negative value (which shouldn't
happen either, but again, this is a defensive check).
Signed-off-by: Jeff King <peff@peff.net>
