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.
