Problem: On MS-Windows, when 'autochdir' is set, diff mode with files in
different directories does not work. (Axel Bender)
Solution: Remember the current directory and use it where needed. (Christian
Brabandt)
d87c36ea5e
---
see: "autochdir + encoding=utf8 messes up diff"
https://groups.google.com/d/msg/vim_dev/QrE4Y2LMJR8/uxigns5KGxYJ
Regarding the individual items in the header:
`Vim - Vi improved by Bram Moolenar`
Bram Moolenar is already mentioned throughout the documentation, as
well as the intro screen.
`:help uganda`
It's already shown to all users who don't use `shortmess+=I` upon
starting nvim, and is already placed prominently in help.txt, i.e.,
`:help` run with no arguments.
`:help credits`
Already mentioned near the top of help.txt.
`README.md`
Already mentioned in develop.txt.
"vimrc" refers to all files that are used to configure Neovim. The main
configuration file is init.vim nowadays.
All nvimrc references that are left refer to a local ".nvimrc" which is read
if 'exrc' is set. ".ngvimrc" references were completely wiped.
Closes#3552.
From a very high level point of view, Vim/Nvim can be described as state
machines following these instructions in a loop:
- Read user input
- Peform some action. The action is determined by the current state and can
switch states.
- Possibly display some feedback to the user.
This is not immediately visible because these instructions spread across dozens
of nested loops and function calls, making it very hard to modify the state
machine(to support more event types, for example).
So far, the approach Nvim has taken to allow more events is this:
- At the very core function that blocks for input, poll for arbitrary events.
- If the event received from the OS is user input, just return it normally to
the callers.
- If the event is not direct result of user input(possibly a vimscript function
call coming from a msgpack-rpc socket or a job control callback), return a
special key code(`K_EVENT`) that is handled by callers where it is safer to
perform arbitrary actions.
One problem with this approach is that the `K_EVENT` signal is being sent across
multiple states that may be unaware of it. This was partially fixed with the
`input_enable_events`/`input_disable_events` functions, which were added as a
mechanism that the upper layers can use to tell the core input functions that it
is ready to accept `K_EVENT`.
Another problem is that the mapping engine is implemented in getchar.c
which is called from every state, but the mapping engine is not aware of
`K_EVENT` so events can break mappings.
While it is theoretically possible to modify getchar.c to make it aware of
`K_EVENT`, this commit fixes the problem with a different approach: Model Nvim
as a pushdown automaton(https://en.wikipedia.org/wiki/Pushdown_automaton). This
design has many advantages which include:
- Decoupling the event loop from the states reponsible for handling events.
- Better control of state transition with less dependency on global variable
hacks(eg: 'restart_edit' global variable).
- Easier removal of global variables and function splitting. That is because
many variables are for state-specific information, and probably ended up being
global to simplify communication between functions, which we fix by storing
state-specific information in specialized structures.
The final goal is to let Nvim have a single top-level event loop represented by
the following pseudo-code:
```
while not quitting
let event = read_event
current_state(event)
update_screen()
```
This closely mirrors the state machine description above and makes it easier to
understand, extend and debug the program.
Note that while the pseudo code suggests an explicit stack of states that
doesn't rely on return addresses(as suggested by the principles of
automata-based programming:
https://en.wikipedia.org/wiki/Automata-based_programming), for now we'll use the
call stack as a structure to manage state transitioning as it would be very
difficult to refactor Nvim to use an explicit stack of states, and the benefits
would be small.
While this change may seem like an endless amount of work, it is possible to
do it incrementally as was shown in the previous commits. The general procedure
is:
1- Find a blocking `vgetc()`(or derivatives) call. This call represents an
implicit state of the program.
2- Split the code before and after the `vgetc()` call into functions that match
the signature of `state_check_callback` and `state_execute_callback.
Only `state_execute_callback` is required.
3- Create a `VimState` "subclass" and a initializer function that sets the
function pointers and performs any other required initialization steps. If
the state has no local variables, just use `VimState` without subclassing.
4- Instead of calling the original function containing the `vgetc()`,
initialize a stack-allocated `VimState` subclass, then call `state_enter` to
begin processing events in the state.
5- The check/execute callbacks can return 1 to continue normally, 0 to break the
loop or -1 to skip to the next iteration. These callbacks contain code that
execute before and after the old `vgetc()` call.
The functions created in step 2 may contain other `vgetc()` calls. These
represent implicit sub-states of the current state, but it is fine to remove
them later in smaller steps since we didn't break compatibility with existing
code.
The new function contains logic that must be executed after handling input in
normal mode and also before the first main loop iteration. Also rename
`main_loop` to `normal_enter` and move it to normal.c
Note about ~/.local/share/nvim/site used in one usr_\* file: this one talks
about user-local installation of third-party plugins, and
~/.local/share/nvim/site is the proper place for them. Most other files talk
about user own configuration and this is ~/.config.
- Add functions that are able to query XDG.
- Replace defaults for
- &runtimepath. Does not follow #78.
- &viewdir.
- &undodir.
- &directory.
- &backupdir. Does not follow #78.
- vimrc location.
- Remove user vimrc file line from :version message.
Notes:
- E136 code greatly changed its meaning: now it is write error and not read
error.
- E195 was removed because shada_read_everything will already do all the
necessary error reporting.
- E886 can be reported by both :rshada and :wshada, but :rshada comes first and
AFAIR it is the only error which is not E575 and can be reported by :rshada.
What works:
1. ShaDa file dumping: header, registers, jump list, history, search patterns,
substitute strings, variables.
2. ShaDa file reading: registers, global marks, variables.
Most was not tested.
TODO:
1. Merging.
2. Reading history, local marks, jump and buffer lists.
3. Documentation update.
4. Converting some data from &encoding.
5. Safer variant of dumping viminfo (dump to temporary file then rename).
6. Removing old viminfo code (currently masked with `#if 0` in a ShaDa file for
reference).
The call to `event_init()` was too late. `command_line_scan()` in `main()` could
already need the loop initialized. Ref https://github.com/neovim/neovim/issues/3045#issuecomment-123405833.
A consequence of this change is that it was necessary to move the
`channel_from_stdio()` call to `command_line_scan()` when embedded_mode is set.
- Improve the implementation of deferred/immediate events.
- Use the new queue module to change how/when events are queued/processed by
giving a private queue to each emitter.
- Immediate events(which only exist to break uv_run recursion) are now
represented in the `loop->fast_events` queue.
- Events pushed to child queues are propagated to the event loop main queue and
processed as K_EVENT keys.
The main problem is that <c-c> is a default mapping but also sets got_int.
Because of the former, normal_cmd() is kicked off which eventually leads to
sourcing the clipboard provider. But due to the latter, do_source() throws an
error, because got_int is set.
This is a temporary workaround and sources the clipboard provider before
main_loop(), if &clipboard is set.
References #3023.
- New libuv/pty process abstraction with simplified API and no globals.
- Remove nvim/os/job*. Jobs are now a concept that apply only to programs
spawned by vimscript job* functions.
- Refactor shell.c/channel.c to use the new module, which brings a number of
advantages:
- Simplified API, less code
- No slots in the user job table are used
- Not possible to acidentally receive data from vimscript
- Implement job table in eval.c, which is now a hash table with unilimited job
slots and unique job ids.
- Add event loop abstraction module under src/nvim/event. The
src/nvim/event/loop module replaces src/nvim/os/event
- Remove direct dependency on libuv signal/timer API and use the new abstraction
instead.
- Replace all references to uv_default_loop() by &loop.uv, a new global variable
that wraps libuv main event loop but allows the event loop functions to be
reused in other contexts.
This event loop is just a stub instance used in synchronous libuv function
calls, it needs to be decoupled from the main event loop in order to run it from
another thread.
Error messages in general should be namespaced, especially in the
context of a shell. Given the possibility of a backgrounded job printing
messages to standard output/error, namespacing these messages should
avoid any confusion as to where the message came from.
Helped-by: Scott Prager <splinterofchaos@gmail.com>
Helped-by: oni-link <knil.ino@gmail.com>
This removes the need for preprocessor defines as array indices, and
brings error handling more in line with other files, which for the most
most part to use constant strings (also, see `globals.h`).
Helped-By: Nicolas Hillegeer <nicolas@hillegeer.com>
Making an environment variable empty can be a way of unsetting it for
platforms that don't support unsetenv(). In most cases, we treat empty
variables as having been unset. For all others, use os_env_exists().
- Create a private libuv loop instead of re-using uv_default_loop(), to
avoid conflict[1] with existing watcher(s) on the fd.
- Expose the global "input" fd as a getter instead of a mutable global.
[1] .deps/build/src/libuv/src/unix/core.c:833:
uv__io_stop: Assertion `loop->watchers[w->fd] == w' failed.
If stdin is non-blocking, many tools (e.g. cat(1), read(1)) which assume
that stdin is blocking, will break in odd ways:
read: read error: 0: Resource temporarily unavailable
cat: -: Resource temporarily unavailable
rm: error closing file
libuv puts stdin in nonblocking mode, and leaves it that way at exit
(this is apparently by design). So, before this commit, this always
works (because the shell clobbers O_NONBLOCK):
$ nvim --cmd q
$ read
...but these forms do _not_ work:
$ nvim --cmd q && read
$ echo foo | nvim --cmd q && read
$ nvim && read
After this commit, all of the above forms work.
Background:
437b4397b9 (diff-41f4d294430cd8c36538999d62681ae2)https://github.com/fish-shell/fish-shell/issues/176#issuecomment-15800155
- bash (and other shells: zsh, tcsh, fish), upon returning to the
foreground, always sets fd 0 back to blocking mode. This practice only
applies to stdin, _not_ stdout or stderr (in practice these fds may be
affected anyways).
- bash/zsh/tcsh/fish do _not_ restore the non-blocking status of stdin
when _resuming a job_.
- We do _not_ save/restore the original flags visible to
fcntl(F_[SG]ETFL), because (counterintuitively) that isn't expected.
Helped-by: oni-link <knil.ino@gmail.com>
Closes#2086Closes#2377
---
Note: The following implementation of stream_set_blocking() was
discarded, because it resulted in a failed libuv assertion[1]:
int stream_set_blocking(int fd, bool blocking)
{
uv_pipe_t stream;
uv_pipe_init(uv_default_loop(), &stream, 0);
uv_pipe_open(&stream, fd);
int retval = uv_stream_set_blocking((uv_stream_t *)&stream, blocking);
uv_close((uv_handle_t *)&stream, NULL);
return retval;
}
[1] .deps/build/src/libuv/src/unix/core.c:833: uv__io_stop: Assertion `loop->watchers[w->fd] == w' failed.
This is done for consistency with '-h' and '--help'.
While here, also move the mch_exit() call out of usage
to make it clear what is being done.
Helped-by: Justin M. Keyes <justinkz@gmail.com>
