This implements the primary environment stack, and other environments such
as the null and snapshot environments, in Rust. These are used to implement
the push and pop from block scoped commands such as `for` and `begin`, and
also function calls.
Largely routine but for the trampolines in iothread.h and iothread.cpp which
were a real PITA to get correct w/ all their variants.
Integration is complete with all old code ripped out and the tests using the
rust version of the code.
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.
Most of it is duplicated, hence untested.
Functions like mbrtowc are not exposed by the libc crate, so declare them
ourselves.
Since we don't know the definition of C macros, add two big hacks to make
this work:
1. Replace MB_LEN_MAX and mbstate_t with values (resp types) that should
be large enough for any implementation.
2. Detect the definition of MB_CUR_MAX in the build script. This requires
more changes for each new libc. We could also use this approach for 1.
Additionally, this commit brings a small behavior change to
read_unquoted_escape(): we cannot decode surrogate code points like \UDE01
into a Rust char, so use � (\UFFFD, replacement character) instead.
Previously, we added such code points to a wcstring; looks like they were
ignored when printed.
wcs2string converts a wide string to a narrow one. The result is
null-terminated and may also contain interior null-characters.
std::string allows this.
Rust's null-terminated string, CString, does not like interior null-characters.
This means we will need to use Vec<u8> or OsString for the places where we
use interior null-characters.
On the other hand, we want to use CString for places that require a
null-terminator, because other Rust types don't guarantee the null-terminator.
Turns out there is basically no overlap between the two use cases, so make
it two functions. Their equivalents in Rust will have the same name, so
we'll only need to adjust the type when porting.
Prior to this change, abbreviations were stored as fish variables, often
universal. However we intend to add additional features to abbreviations
which would be very awkward to shoe-horn into variables.
Re-implement abbreviations using a builtin, managing them internally.
Existing abbreviations stored in universal variables are still imported,
for compatibility. However new abbreviations will need to be added to a
function. A follow-up commit will add it.
Now that abbr is a built-in, remove the abbr function; but leave the
abbr.fish file so that stale files from past installs do not override
the abbr builtin.
Closes#9240.
Squash of the following commits (in reverse-chronological order):
commit 03b5cab3dc40eca9d50a9df07a8a32524338a807
Author: Mahmoud Al-Qudsi <mqudsi@neosmart.net>
Date: Sun Sep 25 15:09:04 2022 -0500
Handle differently declared posix_spawnxxx_t on macOS
On macOS, posix_spawnattr_t and posix_spawn_file_actions_t are declared as void
pointers, so we can't use maybe_t's bool operator to test if it has a value.
commit aed83b8bb308120c0f287814d108b5914593630a
Author: Mahmoud Al-Qudsi <mqudsi@neosmart.net>
Date: Sun Sep 25 14:48:46 2022 -0500
Update maybe_t tests to reflect dynamic bool conversion
maybe_t<T> is now bool-convertible only if T _isn't_ already bool-convertible.
commit 2b5a12ca97b46f96b1c6b56a41aafcbdb0dfddd6
Author: Mahmoud Al-Qudsi <mqudsi@neosmart.net>
Date: Sun Sep 25 14:34:03 2022 -0500
Make maybe_t a little harder to misuse
We've had a few bugs over the years stemming from accidental misuse of maybe_t
with bool-convertible types. This patch disables maybe_t's bool operator if the
type T is already bool convertible, forcing the (barely worth mentioning) need
to use maybe_t::has_value() instead.
This patch both removes maybe_t's bool conversion for bool-convertible types and
updates the existing codebase to use the explicit `has_value()` method in place
of existing implicit bool conversions.
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!
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.
Or should we stop using it?
I'm fine with either always or never using auto-formatting but our current
way of using it only sometimes is confusing.
No functional change.
This adds a line to `set --show`s output like
```
$PATH: originally inherited as |/home/alfa/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl:/var/lib/flatpak/exports/bin|
```
to help with debugging.
Note that this means keeping an additional copy of the original
environment around. At most this would be one ARG_MAX's worth, which
is about 2M.
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.
This gets the passwd entry for $USER (if it is set). If that gives the
same uid that geteuid() gives us, we assume the data is correct.
If not, we reset $USER (and $HOME if it's empty) from the passwd value for our UID.
This allows using $USER in a prompt even if you've `su`d. Bash gets around this by having a special escape in its $PS1 DSL that checks passwd instead.
Fixes#8583
Currently,
set -q --unpath PATH
simply ignores the "--unpath" bit (and same for "--path").
This changes it, so just like exportedness you can check pathness.
+ No functional change here, just renames and #include changes.
+ CMake can't have slashes in the target names. I'm suspciious of
that weird machinery for test, but I made it work.
+ A couple of builtins did not include their own headers, that
is no longer the case.
* Add `set --function`
This makes the function's scope available, even inside of blocks. Outside of blocks it's the toplevel local scope.
This removes the need to declare variables locally before use, and will probably end up being the main way variables get set.
E.g.:
```fish
set -l thing
if condition
set thing one
else
set thing two
end
```
could be written as
```fish
if condition
set -f thing one
else
set -f thing two
end
```
Note: Many scripts shipped with fish use workarounds like `and`/`or`
instead of `if`, so it isn't easy to find good examples.
Also, if there isn't an else-branch in that above, just with
```fish
if condition
set -f thing one
end
```
that means something different from setting it before! Now, if
`condition` isn't true, it would use a global (or universal) variable of
te same name!
Some more interesting parts:
Because it *is* a local scope, setting a variable `-f` and
`-l` in the toplevel of a function ends up the same:
```fish
function foo2
set -l foo bar
set -f foo baz # modifies the *same* variable!
end
```
but setting it locally inside a block creates a new local variable
that shadows the function-scoped variable:
```fish
function foo3
set -f foo bar
begin
set -l foo banana
# $foo is banana
end
# $foo is bar again
end
```
This is how local variables already work. "Local" is actually "block-scoped".
Also `set --show` will only show the closest local scope, so it won't
show a shadowed function-level variable. Again, this is how local
variables already work, and could be done as a separate change.
As a fun tidbit, functions with --no-scope-shadowing can now use this to set variables in the calling function. That's probably okay given that it's already an escape hatch (but to be clear: if it turns out to problematic I reserve the right to remove it).
Fixes#565
This doesn't work.
The real thing that tells if something is read-only is
electric_var_t::readonly().
This wasn't used, and we provide no way to make a variable read-only,
which makes this an unnecessary footgun.
