This can be used to determine whether the previous command produced a real status, or just carried over the status from the command before it. Backgrounded commands and variable assignments will not increment status_generation, all other commands will.
In practice this means that, if fish ever gets multiple variable stacks,
we will only incorporate environment variable changes from other fish
instances on the "main thread."
Profiling revealed string comparison in variable lookups to be a
significant hotspot. This change causes `make test` to complete ~4.5%
faster per `hyperfine`.
fish's handling of terminal sizes is currently rather twisted. The
essential problem is that the terminal size may change at any point from a
SIGWINCH, and common_get_{width,height} may modify it and post variable
change events from arbitrary locations.
Tighten up the semantics. Assign responsibility for managing the tty size
to a new class, `termsize_container_t`. Rationalize locking and reentrancy.
Explicitly nail down the relationship between $COLUMNS/$LINES and the tty
size. The new semantics are: whatever changed most recently takes
precendence.
Variables like $status and $history showed up in all scopes, including
universal, when querying with `set -q` or `set -S`.
This makes it so they all only count as set in global scope, because
we already only allow assignment to electric variables in global scope.
Fixes#7032
fish will react to certain variable modifications, such as "TZ." Only do
this if the main stack is modified. This has no effect now because there
is always a single stack, but will become important when concurrent
execution is supported.
PATH and CDPATH have special behavior around empty elements. Express this
directly in env_stack_t::set rather than via variable dispatch; this is
cleaner.
Universal exported variables (created by `set -xU`) used to show up
both as universal and global variable in child instances of fish.
As a result, when changing an exported universal variable, the
new value would only be visible after a new login (or deleting the
variable from global scope in each fish instance).
Additionally, something like `set -xU EDITOR vim -g` would be imported
into the global scope as a single word resulting in failures to
execute $EDITOR in fish.
We cannot simply give precedence to universal variables, because
another process might have exported the same variable. Instead, we
only skip importing a variable when it is equivalent to an exported
universal variable with the same name. We compare their values after
joining with spaces, hence skipping those imports does not change the
environment fish passes to its children. Only the representation in
fish is changed from `"vim -g"` to `vim -g`.
Closes#5258.
This eliminates the issue #5348 for universal variables.
Because an exported universal variable must be exported in all variable
stacks, explicit invalidation is infeasible. Switch the universal variables
to a generation count.
Prior to this fix, fish would invalidate the exported variable list
whenever an exported variable changes. However we soon will not have a
single "exported variable list." If a global variable changes, it is
infeasible to find all exported variable lists and invalidate them.
Switch to a new model where we store a list of generation counts. Every
time an exported variable changes, the node gets a new generation. If the
current generation list does not match the cached one, then we know that
our exported variable list is stale.
This makes the following changes:
1. Events in background threads are executed in those threads, instead of
being silently dropped
2. Blocked events are now per-parser instead of global
3. Events are posted in builtin_set instead of within the environment stack
The last one means that we no longer support event handlers for implicit
sets like (example) argv. Instead only the `set` builtin (and also `cd`)
post variable-change events.
Events from universal variable changes are still not fully rationalized.
When setting a variable without a specified scope, we should give priority
to an existing local or global above an existing universal variable with
the same name.
In 16fd780484 there was a regression that
made universal variables have priority.
Fixes#5883
Prior to this fix, a function_block stored a process_t, which was only used
when printing backtraces. Switch this to an array of arguments, and make
various other cleanups around null terminated argument arrays.
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.
env_scoped_t lives between environment_t and env_stack_t.
It represents the read-only logic of env_stack_t and will be used to back
the new environment snapshot implementation.
Prior to this change, fish used a global flag to decide if we should check
for changes to universal variables. This flag was then checked at arbitrary
locations, potentially triggering variable updates and event handlers for
those updates; this was very hard to reason about.
Switch to triggering a universal variable update at a fixed location,
after running an external command. The common case is that the variable
file has not changed, which we can identify with just a stat() call, so
this is pretty cheap.
When popping a scope from the environment stack, we currently do a lot of
nonsense like looking for changed curses variables. We want to centralize
this in env_stack_t so that it can be migrated to the env_dispatch logic.
Move this logic up one level in preparation for doing that.
This new file is supposed to encapsulate all of the logic around
reacting to variable changes, as opposed to the environment core.
This is to help break up the env.cpp monolith.
This switches env_var_t to be an immutable value type, and stores its
contents via a shared_ptr. This eliminates string copying when fetching
env_var_t values.
Mostly related to usage _(L"foo"), keeping in mind the _
macro does a wcstring().c_str() already.
And a smattering of other trivial micro-optimizations certain
to not help tangibly.
Since Unicode 9, the width of some characters changed to 2.
Depending on the system, it might have support for it, or it might
not.
Instead of hardcoding specific glibc etc versions, we check what the
system wcwidth says to "😃", U+1F603 "Grinning Face With Big Eyes".
The intention is to, in most cases, make setting $fish_emoji_width
unnecessary, but since it sets the "guessed_emoji_width", that variable still takes precedence if it is set.
Unfortunately this approach has some caveats:
- It relies on the locale being set to a unicode-supporting one.
(C.UTF-8 is unfortunately not standard, so we can't use it)
- It relies on the terminal's wcwidth having unicode9 support IFF the
system wcwidth does.
This is like #5722, but at runtime.
The additional caveat is that we don't try to achieve a unicode
locale, but since we re-run the heuristic when the locale changes (and
we try to get a unicode locale), we should still often get the correct
value.
Plus if you use a C locale and your terminal still displays emoji,
you've misconfigured your system.
Fixes#5722.
Prior to this fix, an "event" was used as both a predicate on which events
to match, and also as the event itself. Re-express these concepts
distinctly: an event is something that happened, an event_handler is the
predicate and name of the function to execute.
Taking advantage of the maybe_t's, the logic and nesting here
can be a bit less intense.
Small adjustments to debug output, and found a more accurate
version number for Lion Terminal.app.
Longer term we should have a terminal_t class or something
encapsulating all the kinds of terminal detection we have
with methods that return the color support, and also stuff
like whether the terminal has the newline glitch, the
ambiguous width character behavior, etc.
