Today the reader exposes its internals directly, e.g. to the commandline
builtin. This is of course not thread safe. For example in concurrent
execution, running `commandline` twice in separate threads would cause a
race and likely a crash.
Fix this by factoring all the commandline state into a new type
'commandline_state_t'. Make it a singleton (there is only one command
line
after all) and protect it with a lock.
No user visible change here.
This only uses the functions fish ships with, but still doesn't allow
any *customization*, which is the point of no-config.
This makes it a lot more usable, given that the actual normal prompt
and things are there.
This still doesn't set any colors, because we don't run
__fish_config_interactive because we don't read config.fish (any
config.fish), because that would run the snippets.
It's not super clear what $SHLVL is useful for, but the current
definition is essentially
"number of shells in the parent processes + 1"
which isn't *super useful*?
Bash's behavior here is a bit weird in that it increments $SHLVL
basically always, but since it auto-execs the last process it will
decrement it again, so in practice it's often not incremented.
E.g.
```
> echo $SHLVL
1
> bash -c 'echo $SHLVL; bash'
2
>> echo $SHLVL
2
```
Both bashes here end up having the same $SHLVL because this is
equivalent to `echo $SHLVL; exec bash`. Running `echo $SHLVL` and then
`bash -c 'echo $SHLVL'` in an interactive bash will have a different
result (1 and 2) because that doesn't *exec* the inner bash.
That's not something we want to get into, so what we do is increment
$SHLVL in every interactive fish. Non-interactive fish will simply
import the existing value.
That means if you had e.g. a bash that runs a fish script that ends up
opening a new fish session, you would have a $SHLVL of *2* - one for the
bash, and one for the inner fish.
We key this off is_interactive_session() (which can also be enabled
via `fish -i`) because it's easy and because `fish -i` is asking for
fish to be, in some form, "interactive".
That means most of the time $SHLVL will be "how many shells am I deep,
how often do I have to `exit`", except for when you specifically asked
for a fish to be "interactive". If that's a problem, we can rethink it.
Fixes#7864.
Several functions including wgetopt and execve operate on null-terminated
arrays of nul-terminated pointers: a list of pointers to C strings where
the last pointer is null. Prior to this change, each process_t stored its
argv in such an array. This had two problems:
1. It was awkward to work with this type, instead of using std::vector,
etc.
2. The process's arguments would be rearranged by builtins which is
surprising
Our null terminated arrays were built around a fancy type that would copy
input strings and also generate an array of pointers to them, in one big
allocation.
Switch to a new model where we construct an array of pointers over
existing strings. So you can supply a `vector<string>` and now
`null_terminated_array_t` will just make a list of pointers to them. Now
processes can just store their argv in a familiar wcstring_list_t.
Add compile-time checks to ensure list of string subcommands, builtins,
and electric variables are kept in asciibetical order to facilitate
binary search lookups.
If given a windows path like `F:\foo`, this currently ends up
assert()ing in path_normalize_for_cd.
Instead, since these paths violate a bunch of assumptions we make, we
reject them and fall back on getting $PWD via getcwd() (which should
give us a nice proper unixy path).
Fixes#7636.
This isn't tested because it would require a system where a windowsy
path passes paths_are_same_file, and on the unix systems we run our
tests that's impossible as far as I can tell?
Prior to this change, histories were immortal and allocated with either
unique_ptr or just leaked via new. But this can result in races in the
path detection test, as the destructor races with the pointer-captured
history. Switch to using shared_ptr.
Prior to this change, `fish_private_mode` worked by just suppressing
history outright. With this change, `fish_private_mode` can be toggled on
and off. Commands entered while `fish_private_mode` is set are stored but
in memory only; they are not written to disk.
Fixes#7590Fixes#7589
fish_user_paths is a fish-specific variable that can be persisted by
making it a universal variable or by making it a global variable set at
startup in `config.fish`.
Since it is not defined in a clean installation, a user could
inadvertently create it as `set -Ux fish_user_paths ....` the first
time, creating a horrible, ugly, self-loathing mess that will have you
chasing ghosts and bisecting for naught once fish re-imports
fish_user_paths as a *global* variable that shadows the universal one.
While that is true for any universal variable that is re-imported as a
global variable, only fish_user_paths has the potential to really screw
things up because we also re-export PATH based off of its value in turn.
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.
