There are many places where we want to treat a missing variable the same as
a variable with an empty value.
In C++ we handle this by branching on maybe_t<env_var_t>::missing_or_empty().
If it returns false, we go on to access maybe_t<env_var_t>::value() aka
operator*.
In Rust, Environment::get() will return an Option<EnvVar>.
We could define a MissingOrEmpty trait and implement it for Option<EnvVar>.
However that will still leave us with ugly calls to Option::unwrap()
(by convention Rust does use shorthands like *).
Let's add a variable getter that returns none for empty variables.
This reverts commit 3d8f98c395.
In addition to the issues mentioned on the GitHub page for this commit,
it also broke the CentOS 7 build.
Note one can locally test the CentOS 7 build via:
./docker/docker_run_tests.sh ./docker/centos7.Dockerfile
Be more careful with sign extension issues stemming from the differences in how
an untyped literal is promoted to an integer vs how a typed (and signed) `char`
is promoted to an integer.
Also convert some `const[expr] static xxx` to `const[expr] xxx` where it makes
sense to let the compiler deduce on its own whether or not to allocate storage
for a constant variable rather than imposing our view that it should have STATIC
storage set aside for it.
A few call sites were not making use of the `XXX_LEN` definitions and were
calling `strlen(XXX)` - these have been updated to use `const_strlen(XXX)`
instead.
I'm not sure if any toolchains will have raise any issues with these changes...
CI will tell!
It seems that the WSLv1 implementation of pselect(2) does not check for
undelivered signals after the temporary sigmask is un-applied from the thread in
question.
Let's hope this doesn't causes build failures for e.g. musl: I just
know it's good on macOS and our Linux CI.
It's been a long time.
One fix this brings, is I discovered we #include assert.h or cassert
in a lot of places. If those ever happen to be in a file that doesn't
include common.h, or we are before common.h gets included, we're
unawaringly working with the system 'assert' macro again, which
may get disabled for debug builds or at least has different
behavior on crash. We undef 'assert' and redefine it in common.h.
Those were all eliminated, except in one catch-22 spot for
maybe.h: it can't include common.h. A fix might be to
make a fish_assert.h that *usually* common.h exports.
Prior to this commit, setting a universal variable may trigger syncing
against the file which will modify other universal variables. But if we
want to support multiple environments we need the parser to decide when to
sync uvars. Shift the decision of when to sync to the parser itself. When a
universal variable is modified, now we just set a flag and it's up to the
(main) parser when to pick it up. This is hopefully just a refactoring with
no user-visible changes.
Say the user has a multi-char binding (typically an escape sequence), and a
signal arrives partway through the binding. The signal has an event handler
which enques some readline event, for example, `repaint`. Prior to this
change, the readline event would cause the multi-char binding to fail. This
would cause bits of the escape sequence to be printed to the screen.
Fix this by noticing when a sequence was "interrupted" by a non-char event,
and then rotating a sequence of such interruptions to the front of the
queue.
Fixes#8628
readch_timed is called after reading the escape character \x1b. The escape
char may be a standalone key press or part of an escape sequence; fish
waits for a little bit (per the fish_escape_delay_ms variable) to see if
something else arrives, before treating it as standalone escape-key press.
It may happen that a signal is delivered while fish waits. Prior to this
change we would treat this signal as a "nothing was read" event, causing
escape to be wrongly treated as standalone.
Avoid this by using pselect() with a full signal mask, to ensure this call
completes.
Cygwin tests are failing because cygwin has a low limit of only 64 fds in
select(). Extend select_wrapper_t to also support using poll(), according to
a FISH_USE_POLL new define. All systems now use poll() except for Mac.
Rename select_wrapper_t to fd_readable_set_t since now it may not wrap
select().
This allows the deep-cmdsub.fish test to pass on Cygwin.
This reverts commit b56b230076.
which somehow made us miss repaints on uvar notifications.
The commit was a workaround for a polling bug which was later properly
fixed by 7c5b8b855 ("Use the uvar notifier pipe timestamp to avoid
excessive polling"), so it's no longer necessary.
Add a system test. If I had a better understanding of the bug I could
probably write a better test.
Fixes#8088
In the named pipe notifier, notifications are broadcast by writing to the
pipe, waiting briefly, and then reading it back. When clients see the pipe
as readable, they report the uvars as potentially changed and fish will
sync against the uvar file.
Prior to this change, we synced repeatedly when the pipe was readable. But
we can do somewhat better by also checking the named pipe's timestamp (via
fstat). If the pipe has not changed, then we can skip the sync even if
there is currently data lingering on it.
With this change we should sync against the variable file less often
(typically once or twice per write); in the next change we refactor this
logic so it's easier to follow.
Reproducible at least on Linux, where the "named pipe" universal
variable notifier is used:
rm -rf build/test/xdg_config
XDG_CONFIG_HOME=build/test/xdg_config ./build/fish -c "xterm -e ./build/fish"
The child fish reacts to keyboard input with a noticeable initial
delay. This is because the universal variable file is polled over
a million times, even when I immediately press Control-D. This polling
prevents readb() from handling keyboard input.
Before commit 939aba02d ("Refactor input_common.cpp:readb"), readb()
reacted to keyboard input even when there were universal variable
notifications. Restore this behavior, but make sure to call the
universal variable notifier after the new "prepare_to_select" logic.
Maybe the problem is in the notifier but the old behavior was sane.
Fixes the problems described in
7a556ec6f2 (commitcomment-49773677)
Adding "-d uvars-file" to the reproducesr shows that we are checking
the uvar file repeatedly:
uvar-file: universal log sync
uvar-file: universal log sync elided based on fast stat()
uvar-file: universal log no modifications
This concerns printing status messages for background jobs which have
stopped or finished. Previously fish would do this from two places:
1. Before running a command (including empty string)
2. If a signal is received during select()
So if the job finishes while fish is doing something else (like running an
event handler) then we would not print status messages until the user hit
return. This caused the job_summary.py test to be flaky.
Fix this by splitting the interrupt handler into two parts: a part that
handles signals (e.g. triggering exit from the reader), and a part that
always runs just before blocking in select(). This second part always
reaps jobs and prints their status messages. This narrows the window for a
job exit to be "missed" before fish blocks in select, and should make the
job_summary.py test more reliable.
This concerns the problem of "injecting" fancy fish bits like job reaping
into the "common" input stuff which is also used by fish_key_reader.
Instead of providing a callback, make the input event queue a base class
with virtual functions. This allows for a richer interface and simplifies
some memory management issues.
readb is used to read a single byte from stdin, or maybe update universal
variables, or maybe invoke completion handlers, etc. Previously it
returned char_event_t but this is more complex than necessary; instead we
can just have it return a single byte, or one of a few special error
codes. This makes the readb's role more clear.
"The" interrupt handler is used when we get a signal while waiting at the
prompt. Switch it from a global function pointer to an std::function. This
is a mild refactoring which itself will be replaced soon.
Now that timeouts are stored in the event queue peeker, we can remove the
notion of timeout events altogether. Instead you may ask for an event with
a timeout, and get back none on timeout. This simplifies how input events
work.
select_wrapper_t wraps up the annoying bits of using select(): keeping
track of the max fd, passing null for boring parameters, and
constructing the timeout. Introduce a wrapper struct for this and
replace the existing uses of select() with the wrapper.
In readch_timed, we were passing 1 as the number of fds. This is correct if
the fd is 0 (stdin) which it typically is; however this will fail if in_ is
not stdin. Switch to in_ + 1.
While the user waits at the prompt, fish is waiting in select(), on stdin.
The sigio based universal notifier interrupts select() by arranging for a
signal to be delivered, which causes select() to return with EINTR.
However we weren't polling the notifier at that point so we would not
notice uvar changes, until we got some real input.
I didn't notice this when testing, because my testing was changing fish
prompt colors which updated the prompt for other reasons.
Fixes#7671.
This runs build_tools/style.fish, which runs clang-format on C++, fish_indent on fish and (new) black on python.
If anything is wrong with the formatting, we should fix the tools, but automated formatting is worth it.
This was a sort of side channel that was only used to propagate redraws
after universal variable changes. We can eliminate it and handle these
more directly.
