This adopts the new function store, replacing the C++ version.
It also reimplements builtin_function in Rust, as these was too coupled to
the function store to handle in a separate commit.
DirIter had a serious bug where it would crash on an invalid path. Make it more
robust and rationalize its error handling. Move it into its own module and add
tests.
Prior to this change, we had a silly wrapper type EventDescription which wrapped
EventType, which actually described the event.
Remove this wrapper and rename EventType to EventDescription (since it describes
more than just the type of event).
The RETURN_IN_ORDER argparse mode (enabled via leading '-') causes non-options
(i.e. positionals) to be returned intermixed with options in the original order,
instead of being permuted to the end. Such positionals are identified via the
option sentinel of char code 1. Use a real named constant for this return,
rather than weird stuff like '\u{1}'
This also allows scoped feature tests that makes testing feature flags thread-safe.
As in you can guarantee that the test actually has the correct feature flag
value, regardless of which other tests are running in parallell.
This also cleans up and removes unnecessary usage of FFI-oriented `feature_metadata_t`,
which is only used from Rust code after `builtins/status` was ported.
Note this is slightly incomplete - the FD is not moved into the parser, and so
will be freed at the end of each directory change. The FD saved in the parser is
never actually used in existing code, so this doesn't break anything, but will
need to be corrected once the parser is ported.
This shaves about 9 seconds off of the runtime, and makes the test
deterministic.
We do not touch the test_convert test because there is a known failure and we
need to track it down before making it deterministic.
Get some stuff out of the common module, which is growing large.
Also migrate the tests into "native" Rust tests so they will run in parallel.
We have to use an explicit setlocale() call to get a multibyte locale, for the
"crazy" tests.
Prior to this commit, FLOG used the ffi bridge to get the output fd. Invert
this: have fish set the output fd within main. This allows FLOG to be used in
pure Rust tests.
Two small fixes:
1. ParsedSourceRef, if present, should not be None; express that in the type.
2. ParsedSourceRef is intended to be shareable across threads; make it so.
Use as_wstr() instead of from_ffi() in a few places to avoid an allocation,
and make job_control_t work in &wstr instead of &str to reduce complexity at
the call sites.
- Using an option makes it much clearer that the check for empty args is
redundant.
- Also prefer implementing TryFrom only for &str, to not hide the string
conversion and allocation happening.
This was present in the C++ version for command, though never for type.
Checking over all elements of PATH can be slow on some platforms eg
WSL2, so only do that when used with `--all`.
Based on discussion in
https://github.com/fish-shell/fish-shell/pull/9856
This restores the status quo where builtins are like external commands
in that they can't see anything after a 0x00, because that's the c-style
string terminator.
* Make NULs work for builtins
This switches from passing a c-string to output_stream_t::append to
passing a proper string.
That means a builtin that prints a NUL no longer crashes with "thread '' panicked
at 'String contained intermediate NUL character: ".
Instead, it will actually handle the NUL, even as an argument.
That means something like
`echo foo\x00bar` will now actually print a NUL instead of truncating
after the `foo` because we passed c-strings around everywhere.
The former is *necessary* for e.g. `string`, the latter is a change
that on the whole makes dealing with NULs easier, but it is a
behavioral change.
To restore the c-string behavior we would have to truncate arguments
at NUL.
See #9739.
* Use AsRef instead of trait bound
Prior to this change, parser_t exposed an environment_t, and Rust had to go
through that. But because we have implemented Environment in Rust, it is
better to just expose the native Environment from parser_t. Make that
change and update call sites.
The writembs macro was ported from C++, which attempted to detect when a NULL
termcap was used. However we have never gotten a bug report from this. Bravely
remove it.
The outputter code has a lot of checks that string capabilities are non-empty;
just enforce that at the curses layer so we can remove those checks.
Also remove some types and traits, replacing them with simple functions.
Per code review, we think that tparm does nothing when there are no parameters,
and it is safe to remove it, even though this is a break from C++. This
simplifies some code.
This makes some simplifications to scoped_push and ScopeGuard:
1. ScopeGuard no longer uses ManuallyDrop; the memory management is now
trivial and no longer requires `unsafe`.
2. The functions `cancel` and `rollback` have been removed, as
these were unused. They can be added back later if needed.
3. `scoped_push` has been simplified in both signature and implementation.
4. `Projection` is no longer required and has been removed.
Also add some tests.
We can't just call the Rust version of `fish_setlocale()` without also either
calling the C++ version of `fish_setlocale()` or removing all `src/complete.cpp`
variables that are initialized and aliasing them to their new rust counterparts.
Since we're not interested in keeping the C++ code around, just call the C++
version of the function via ffi until we don't have *any* C++ code referencing
`src/common.h` at all.
Note that *not* doing this and then calling the rust version of
`fish_setlocale()` instead of the C++ version will cause errant behavior and
random segfaults as the C++ code will try to read and use uninitialized values
(including uninitialized pointers) that have only had their rust counterparts
init.
This is not yet used but will take eventually take the place of all (n)curses
access. The curses C library does a lot of header file magic with macro voodoo
to make it easier to perform certain tasks (such as access or override string
capabilities) but this functionality isn't actually directly exposed by the
library's ABI.
The rust wrapper eschews all of that for a more straight-forward implementation,
directly wrapping only the basic curses library calls that are required to
perform the tasks we care about. This should let us avoid the subtle
cross-platform differences between the various curses implementations that
plagued the previous C++ implementation.
All functionality in this module that requires an initialized curses TERMINAL
pointer (`cur_term`, traditionally) has been subsumed by the `Term` instance,
which once initialized with `curses::setup()` can be obtained at any time with
`curses::Term()` (which returns an Option that evaluates to `None` if `cur_term`
hasn't yet been initialized).
Either add rust wrappers for C++ functions called via ffi or port some pure code
from C++ to rust to provide support for the upcoming `env_dispatch` rewrite.
The global variables are moved (not copied) from C++ to rust and exported as
extern C integers. On the rust side they are accessed only with atomic semantics
but regular int access is preserved from the C++ side (until that code is also
ported).
It's not clear whether or not `system_wcwidth()` was picked solely because of
the namespace conflict (which is easily remedied) but using the most obvious
name for this function should be the way to go.
We already have our own overload of `wcwidth()` (`fish_wcwidth()`) so it should
be more obvious which is the bare system call and which isn't.
(I do want to move this w/ some of the other standalone extern C wrappers to the
unix module later.)
Pull in the correct descriptions merged from across the various C++ header and
source files and get rid of the getter function that's only used in one place
but causes us to split the documentation for FISH_EMOJI_WIDTH across multiple
declarations.
This can be used for functions that accept non-Unicode content (i.e. &CStr or
CString) but are often used in our code base with a UTF-8 or UTF-32 string
on-hand.
When such a function is passed a CString, it's passed through as-is and
allocation-free. But when, as is often the case, we have a static string we can
now pass it in directly with all the nice ergonomics thereof instead of having
to manually create and unwrap a CString at the call location.
There's an upstream request to add this functionality to the standard library:
https://github.com/rust-lang/rust/issues/71448
This is more complicated than it needs to be thanks to the presence of CMake and
the C++ ffi in the picture. rsconf can correctly detect the required libraries
and instruct rustc to link against them, but since we generate a static rust
library and have CMake link it against the C++ binaries, we are still at the
mercy of CMake picking up the symbols we want.
Unfortunately, we could detect the gettext symbols but discover at runtime that
they weren't linked in because CMake was compiled with `-DWITH_GETTEXT=0` or
similar (as the macOS CI runner does). This means we also need to pass state
between CMake and our build script to communicate which CMake options were
enabled.
Delegate the `view` and `view_mut` to the newly added `Projection<T>`, which
makes everything oh so much clearer and cleaner. Add comments to clarify what is
happening.
This can be used when you primarily want to return a reference but in order for
that reference to live long enough it must be returned with an object.
i.e. given `Mutex<Foo { bar }>` you want a function to lock the mutex and return
a reference to `bar` but you can't return that reference since it has a lifetime
dependency on `MutexGuard` (which only derefs to all of `Foo` and not just
`bar`). You can return a `Projection` owning the `MutexGuard<Foo>` and set it up
to deref to `&bar`.
This wasn't providing a lot of value, and the license compatibility is iffy.
There's a bit of weirdness in that this now uses a `Box<dyn Error>`,
but since currently nothing actually errors out let's punt that for
later.
This is a terrible way of going about things,
and means we're currently broken on any unix that isn't specifically listed.
But at least it'll build and allow us to keep the FreeBSD CI running.
Historically fish has used the functions `fish_wcstol`, `fish_wcstoi`, and
`fish_wcstoul` (and some long long variants) for most integer conversions.
These have semantics that are deliberately different from the libc
functions, such as consuming trailing whitespace, and disallowing `-` in
unsigned versions.
fish has started to drift away from these semantics; some divergence from
C++ has crept in.
Rename the existing `fish_wcs*` functions in Rust to remove the fish
prefix, to express that they attempt to mirror libc semantics; then
introduce `fish_` wrappers which are ported from C++. Also fix some
miscellaneous bugs which have crept in, such as missing range checks.
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.
owning_null_terminated_array is used for environment variables, where we need to
provide envp for child processes. This switches the implementation from C++ to
Rust.
We retain the C++ owning_null_terminated_array_t; it simply wraps the Rust
version now.
The `u64::from(buf.f_flag)` was needed in two places. The existing handled macOS
which always has a 32-bit statfs::f_flag, but statvfs::f_flag is an `unsigned
long` which means it needs to be coerced to 64-bits on 32-bit targets.
There's no reason to inject prefix into our newly allocated str after storing
pattern in there. Just allocate with the needed capacity up front and then
insert in the correct order.
There's no reason to inject prefix into our newly allocated str after storing
pattern in there. Just allocate with the needed capacity up front and then
insert in the correct order.
The new asan exit handlers are called to get proper ASAN leak reports (as
calling _exit(0) skips the LSAN reporting stage and exits with success every
time).
They are no-ops when not compiled for ASAN.
This ports some signal setup and handling bits to Rust.
The signal handling machinery requires walking over the list of known signals;
that's not supported by the Signal type. Rather than duplicate the list of
signals yet again, switch back to a table, as we had in C++.
This also adds two further pieces which were neglected by the Signal struct:
1. Localize signal descriptions
2. Support for integers as the signal name
This allows the rust code to free up C++ resources allocated for a callback even
when the callback isn't executed (as opposed to requiring the callback to run
and at the end of the callback cleaning up all allocated resources).
Also add type-erased destructor registration to callback_t. This allows for
freeing variables allocated by the callback for debounce_t's
perform_with_callback() that don't end up having their completion called due to
a timeout.
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.
Like the WSL check, this was incorrectly assuming WSL implies
cfg(windows) when it's actually picked up as Linux.
Also, improve over the C++ code by not relying on the build-time WSL
status to determine if we are running on WSL at runtime since it's often
the case that the fish binaries are built on a non-WSL host (for
packaging) then executed on a WSL only at runtime.
(But it's ok to assume if fish has been built for Windows or not Linux
that it will either be run or not run on top of a Win32 character device
system.)
Also, port of the comment and relevant WSL and fish issue links over
from the CPP codebase for posterity.
* Since we already have an allocation of length wstr.len(), it's
probably better to allocate the result (which is strictly less than or
equal to the input length) up-front rather than risk thrashing the Vec
allocation,
* There's no need to compare c2 against '\0' since that will just cause
to_digit(16) to return None anyway,
* Our convert_hex() specialization of to_digit(16) that only checks
capital letters A-F without also checking lowercase a-f isn't
significantly faster than just use to_digit(16), and we already assert
that the input *wasn't* a lowercase a-f before making the call, so
there's no point in using a special function to handle that.
Prior to this change, wstr::split had two weird behaviors:
1. Splitting an empty string would yield nothing, rather than an empty
string.
2. Splitting a string with the separator character as last character
would not yield an empty string.
For example L!("x:y:").split(':') would return ["x", "y"] instead of
what it does in C++, which is ["x", "y", ""].
Fix these.
This reverts commit 76dc849fca.
The warning added in that commit is incorrect. The functions
unescape_string_url and unescape_string_var will not panic, because
char_at() return 0 if the index is equal to its length.
This reverts commit f9c92753c4.
This commit attempted to replace exit_without_destructors() with
std::process::exit; however this is wrong for two reasons:
1. std::process::exit() runs Rust runtime cleanup stuff we don't want
2. std::process::exit() invokes destructors, meaning atexit handlers,
which we don't want.
The type system no longer guarantees that the input string is nul-terminated,
meaning accessing beyond the range-checked `i` a char-at-a-time is no longer
safe. (In C++, we would either be using a plain C string which is always
nul-terminated or we would be using (w)string::cstr() which similarly grants
access to its nul-terminated buffer.)
Aside from that, there's no need to explicitly check `if c2 == '\0'` because
'\0' is not a valid hex digit so the `?` tacked on to `convert_hex_digit(c2)?`
will abort and return `None` anyway.
convert_hex_digit() is not appreciably faster than char::to_digit(16) and makes
the code less maintainable since it encodes certain assumptions; since it's also
not used consistently just drop it in favor of the std fn.
Since the output string (per the decode logic) is always shorter than or equal
to the input string, just reserve the input string size upfront to prevent vec
reallocations.
Somewhat counter-intuitively, this code is active when compiling under *Linux*
and is always false when compiling under Windows. The logic was incorrectly
reversed before (it's easier to reason about when you realize that fish doesn't
even compile under Windows because it uses tons of libc functions).
As the code was actually never compiled, it wasn't actually tested for validity
either and there were some issues that prevented it from compiling that have
since been fixed. The logic has also been adjusted a bit to make it possible to
use the rust-native int parsing instead of `libc::strtod()`.
The code has been changed to use `once_cell::race::OnceBool` instead of
`once_cell::sync::Lazy<T>` which imposes a greater runtime burden with locking
and other overhead. We don't care if the code runs more than once on init (if
calls were to race, though they probably don't) - just that the code isn't
subsequently executed on each call. The `once_cell::race` module is a better fit
here, though it doesn't expose the ergonomic `Lazy<T>` façade around its types.
is_main_thread() and co were previously ported to threads.rs, so remove the
duplicate code and move everything else related to threads there as well. No
need for common.rs to be as long as our old common.cpp!
I left #[deprecated] stubs in common.rs to help redirect anyone porting code
over that we can remove after the port has finished.
Additionally, the fork guards had previously been left as a todo!() item but I
ported that over. They're all called from the now-central threads::init()
function so there isn't a need to call each individual thread-management-fn
manually.
The decision was made a while back to try and embrace/use the native rust thread
functionality and utilities so the manual thread management code has been ripped
out and was replaced with code that marshals the native rust values instead. The
values won't line up with what the C++ code sees, but it never lined up anyway
since each was using a separate counter to keep track of the values.
Except for the indent visitor bits.
Tests for parse_util_detect_errors* are not ported yet because they depend
on expand.h (and operation_context.h which depends on env.h).
This caused math to assert out because it never wrote into the buffer.
Now, presumably it wrote somewhere but I don't know where, so fixing
this seems like a good idea.
Fixes#9735.
The translation is fairly direct though it adds some duplication, for example
there are multiple "match" statements that mimic function overloading.
Rust has no overloading, and we cannot have generic methods in the Node trait
(due to a Rust limitation, the error is like "cannot be made into an object")
so we include the type name in method names.
Give clients like "indent_visitor_t" a Rust companion ("IndentVisitor")
that takes care of the AST traversal while the AST consumption remains
in C++ for now. In future, "IndentVisitor" should absorb the entirety of
"indent_visitor_t". This pattern requires that "fish_indent" be exposed
includable header to the CXX bridge.
Alternatively, we could define FFI wrappers for recursive AST traversal.
Rust requires we separate the AST visitors for "mut" and "const"
scenarios. Take this opportunity to concretize both visitors:
The only client that requires mutable access is the populator. To match the
structure of the C++ populator which makes heavy use of function overloading,
we need to add a bunch of functions to the trait. Since there is no other
mutable visit, this seems acceptable.
The "const" visitors never use "will_visit_fields_of()" or
"did_visit_fields_of()", so remove them (though this is debatable).
Like in the C++ implementation, the AST nodes themselves are largely defined
via macros. Union fields like "Statement" and "ArgumentOrRedirection"
do currently not use macros but may in future.
This commit also introduces a precedent for a type that is defined in one
CXX bridge and used in another one - "ParseErrorList". To make this work
we need to manually define "ExternType".
There is one annoyance with CXX: functions that take explicit lifetime
parameters require to be marked as unsafe. This makes little sense
because functions that return `&Foo` with implicit lifetime can be
misused the same way on the C++ side.
One notable change is that we cannot directly port "find_block_open_keyword()"
(which is used to compute an error) because it relies on the stack of visited
nodes. We cannot modify a stack of node references while we do the "mut"
walk. Happily, an idiomatic solution is easy: we can tell the AST visitor
to backtrack to the parent node and create the error there.
Since "node_t::accept_base" is no longer a template we don't need the
"node_visitation_t" trampoline anymore.
The added copying at the FFI boundary makes things slower (memcpy dominates
the profile) but it's not unusable, which is good news:
$ hyperfine ./fish.{old,new}" -c 'source ../share/completions/git.fish'"
Benchmark 1: ./fish.old -c 'source ../share/completions/git.fish'
Time (mean ± σ): 195.5 ms ± 2.9 ms [User: 190.1 ms, System: 4.4 ms]
Range (min … max): 193.2 ms … 205.1 ms 15 runs
Benchmark 2: ./fish.new -c 'source ../share/completions/git.fish'
Time (mean ± σ): 677.5 ms ± 62.0 ms [User: 665.4 ms, System: 10.0 ms]
Range (min … max): 611.7 ms … 805.5 ms 10 runs
Summary
'./fish.old -c 'source ../share/completions/git.fish'' ran
3.47 ± 0.32 times faster than './fish.new -c 'source ../share/completions/git.fish''
Leftovers:
- Enum variants are still snakecase; I didn't get around to changing this yet.
- "ast_type_to_string()" still returns a snakecase name. This could be
changed since it's not user visible.
A JobId is not supposed to convert to other types.
Since this type is defined as NonZeroU32 (which cannot be -1), we need to
add some conversion functions to match the C++ behavior.
Overall, it would have been better to keep using the C++ type.
The conversion to usize is used for array accesses, so negative values
would cause crashes either way. Let's do it earlier so we can get rid of
the suspect C-style cast.
This allows us to use the scoped push in more scenarios by appeasing the
borrow checker.
Use it in a couple of places instead of ScopeGuard. Hopefully this is makes
porting easier.
Even though we generally dont' want to use this type (because it's immutable),
it can be advantageous when working with the std::fs API. This is because
it implements "AsRef<Path>" which neither of CString and Vec<u8> do.
This is basically a subset of type, so we might as well.
To be clear this is `command -s` and friends, if you do `command grep` that's
handled as a keyword.
One issue here is that we can't get "one path or not" because I don't
know how to translate a maybe_t? Do we need to make it a shared_ptr instead?
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.
Existing C++ code didn't use a function for this but simply added
ENCODE_DIRECT_BASE. In Rust that's more verbose because char won't do
arithmetics, hence the function.
We'll add a dual function for decoding, so let's rename this.
BTW we should get rid of the "wchar" naming, it's just "char" in Rust.
Prior to this change, wcstoi("0x") would fail with missing digits.
However strtoul will "backtrack" to return just the 0 and leave the x as
the remainder. Implement this behavior.
Prior to this change, wcstoi() would return an error if the requested
type were unsigned, and the input had a leading minus sign. However this
causes problems for printf, which expects strtoul behavior.
Add "modulo base" behavior which wraps the negative value to positive.
Factor this into an option; the default is False (but code which
previously used strtoull directly should set it to true).
fish_wcstoi_partial is like fish_wcstoi: it converts from a string to an
int optionally inferring the radix. fish_wcstoi_partial also returns the
number of characters consumed.
Unfortunately we cannot use wide string literals in match statements
(not sure if there's an easy fix).
Because of this, I converted the input to UTF-8 so we could use the match
statement. This conversion is confusing, let's skip it.
Everything but signal handlers has been changed to use `Signal` instead of
`c_int` or `i32` signal values.
Event handlers are using `usize` to match C++, at least for now.
Signal is a newtype around NonZeroI32. We could use NonZeroU8 since all signal
values comfortably fit, but using i32 lets us avoid a fallible attempt at
narrowing values returned from the system as integers to the narrower u8 type.
Known signals are explicitly defined as constants and can be matched against
with equality or with pattern matching in a `match` block. Unknown signal values
are passed-through without causing any issues.
We're using per-OS targeting to enable certain libc SIGXXX values - we could
change this to dynamically detecting what's available in build.rs but then it
might not match what libc exposes, still giving us build failures.
This should be used in lieu of manually targeting individual operating systems
when using features shared by all BSD families.
e.g. instead of
#[cfg(any(target_os = "freebsd", target_os = "dragonflybsd", ...))]
fn foo() { }
you would use
#[cfg(feature = "bsd")]
fn foo() { }
This feature is automatically detected at build-time (see build.rs changes) and
should *not* be enabled manually. Additionally, this feature may not be used to
conditionally require any other dependency, as that isn't supported for
auto-enabled features.
Just address two clippy lints that are fallout from changing the signal type.
There's no longer any need to convert these (which gets rid of an unwrap).
Due to limitations imposed by the borrow checker, there are very few places
where we will be able to use the `ScopedPush` class ported over from the C++
codebase (once you capture the value w/ a `ScopedPush` you can't access the
value - or the mutable reference you used to reach it! - until the `ScopedPush`
object goes out of scope).
This alternative requires binding the previous values to a variable and manually
restoring them in the callback passed to the `ScopeGuard` constructor, but will
work with rust's borrow and `&mut` paradigm.
Currently the `autocxx` generated code does not produce any code intelligence
because `rust-analyzer` can't find the generated code since it's not in the
workspace. Here, we detect `rust-analyzer` by checking for a `RUSTC_WRAPPER`
environment variable containing `rust-analyzer` and changing (or avoid changing)
the output directory accordingly.
Closes#9654.
This was added to support signals; however we are unlikely to use this
for anything else. Remove it; just use a u64 to report signals that have
been set.
This optimizes over both the rust rewrite and the original C++ code. The rust
rewrite saw `std::bitset` replaced with `[bool; 65]` which could result in a
lot of memory copy bandwidth each time we checked for and received no signals.
The original C++ code would iterate over all signal slots to see if any were
set. The code now returns a single u64 and only checks slots that are known to
have signals via an intelligent `Iterator` impl.
You can now use a reference to CxxWString or an allocated UniquePtr<CxxWString>
to get an &wstr temporary to use without having to allocate again (e.g. via
`from_ffi()`).
wchar.rs should not import let alone reexport FFI strings.
Stop re-exporting utf32str! because we use L! instead.
In wchar_ffi.rs, stop re-exporting cxx::CxxWString because that hasn't
seen adoption.
I think we should use re-exports only for aliases like "wstr" or for aliases
into internal modules.
So I'd probably remove `pub use wchar_ffi::wcharz_t = crate::ffi::wcharz_t`
as well.
bool_assert_comparison is stupid, the reason they give is "it's shorter". Well,
`assert!(!foo)` is nowhere near as readable as `assert_eq!(foo, false)` because
of the ! noise from the macro.
Uninlined format args is a stupid lint that Rust actually walked back when they
made it an official warning because you still have to use a mix of inlined and
un-inlined format args (the latter of which won't complain) since only idents
can be inlined.
This shows some of the ugliness of the rust borrow checker when it comes to
safely implementing any sort of recursive access and the need to be overly
explicit about which types are actually used across threads and which aren't.
We're forced to use an `Arc` for `ItemMaker` (née `item_maker_t`) because
there's no other way to make it clear that its lifetime will last longer than
the FdMonitor's. But once we've created an `Arc<T>` we can't call
`Arc::get_mut()` to get an `&mut T` once we've created even a single weak
reference to the Arc (because that weak ref could be upgraded to a strong ref at
any time). This means we need to finish configuring any non-atomic properties
(such as `ItemMaker::always_exit`) before we initialize the callback (which
needs an `Arc<ItemMaker>` to do its thing).
Because rust doesn't like self-referential types and because of the fact that we
now need to create both the `ItemMaker` and the `FdMonitorItem` separately
before we set the callback (at which point it becomes impossible to get a
mutable reference to the `ItemMaker`), `ItemMaker::item` is dropped from the
struct and we instead have the "constructor" for `ItemMaker` take a reference to
an `FdMonitor` instance and directly add itself to the monitor's set, meaning we
don't need to move the item out of the `ItemMaker` in order to add it to the
`FdMonitor` set later.
We were only using their ffi implementations which are automatically
exported/public, but the actual functions we would need if we were to use
FdMonitor and co. in native rust code were either private or missing convenient
wrappers.
The existing code is kept, but a rusty version of these functions is added for
code that needs them.
These should only be temporarily used when porting 1-to-1 from C++; we should
use the std library's `read()` and `write_all()` methods instead in the future.
By extracting the equivalent of i32::cmp() into its own const function,
it becomes a lot easier to see what is happening and the logic can be
more direct.
These will be used in the parser.
Maybe this type should be a struct with boolean fields. The current way has
the upside that the usage is exactly the same as in C++.
For some reason this error is triggered by tests after the Rust port of
ast.cpp. Might want to get to the bottom of this but moving it back
to match the original C++ logic fixes it.
This is one of the few warnings we disable due to false positives. Let's also
disable it in the preprocessing steps needed for the Rust build.
Other warnings we ignore are -Wno-address -Wunused-local-typedefs and
-Wunused-macros. I didn't add them here because I don't expect that they
will be triggered by the headers we give to cxx.
Prior to this fix, the Rust FLOG output was regressed from C++, because
it put quotes around strings. However if we used Display, we would fail
to FLOG non-display types like ThreadIDs.
There is apparently no way in Rust to write a function which formats a
value preferentially using Display, falling back to Debug.
Fix this by introducing two new traits, FloggableDisplay and
FloggableDebug. FloggableDisplay is implemented for all Display types,
and FloggableDebug can be "opted into" for any Debug type:
impl FloggableDebug for MyType {}
Both traits have a 'to_flog_str' function. FLOG brings them both into
scope, and Rust figures out which 'to_flog_str' gets called.
