pspsdk 0.0.2

//! Implementation of various bits and pieces of the `panic!` macro and
//! associated runtime pieces.
//!
//! Specifically, this module contains the implementation of:
//!
//! * Panic hooks
//! * Executing a panic up to doing the actual implementation
//! * Shims around "try"

use core::{
    any::Any,
    fmt, intrinsics,
    mem::{self, ManuallyDrop},
    panic::{Location, PanicPayload},
};

use alloc::{boxed::Box, string::String};

use crate::process;

// Prints to the "panic output", depending on the platform this may be:
// - the standard error output
// - some dedicated platform specific output
// - nothing (so this macro is a no-op)
macro_rules! rtprintpanic {
    ($($t:tt)*) => {
        #[cfg(not(panic = "immediate-abort"))] {
            print(format_args!($($t)*));
        }

        #[cfg(panic = "immediate-abort")]
        {
            let _ = format_args!($($t)*);
        }
    }
}

macro_rules! rtabort {
    ($($t:tt)*) => {
        {
            print_and_die(format_args!("fatal runtime error: {}, aborting\n", format_args!($($t)*)));
        }
    }
}

#[cfg(not(feature = "std"))]
fn print(args: core::fmt::Arguments) {
    use io_core::io::Write;

    cfg_select! {
        not(panic = "immediate-abort") => {
            if cfg!(pbp) {
                crate::io::printing::_dprint(args);
            }

            if let Some(mut out) = crate::os::stdio::panic_output() {
                let _ = out.write_fmt(args);
            }
        },
        _ => {}
    }
}

#[cfg(not(feature = "std"))]
fn print_and_die(args: core::fmt::Arguments) -> ! {
    print(args);
    crate::process::abort();
}

#[inline(never)]
#[cfg(all(not(feature = "std"), panic = "immediate-abort"))]
#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
    crate::process::abort()
}

// Binary interface to the panic runtime that the standard library depends on.
//
// The standard library is tagged with `#![needs_panic_runtime]` (introduced in
// RFC 1513) to indicate that it requires some other crate tagged with
// `#![panic_runtime]` to exist somewhere. Each panic runtime is intended to
// implement these symbols (with the same signatures) so we can get matched up
// to them.
//
// One day this may look a little less ad-hoc with the compiler helping out to
// hook up these functions, but it is not this day!
#[allow(improper_ctypes)]
unsafe extern "C" {
    #[rustc_std_internal_symbol]
    fn __rust_panic_cleanup(payload: *mut u8) -> *mut (dyn Any + Send + 'static);
}

unsafe extern "Rust" {
    /// `PanicPayload` lazily performs allocation only when needed (this avoids
    /// allocations when using the "abort" panic runtime).
    #[rustc_std_internal_symbol]
    fn __rust_start_panic(payload: &mut dyn PanicPayload) -> u32;
}

/// This function is called by the panic runtime if FFI code catches a Rust
/// panic but doesn't rethrow it. We don't support this case since it messes
/// with our panic count.
#[cfg(not(test))]
#[cfg(not(feature = "std"))]
#[rustc_std_internal_symbol]
extern "C" fn __rust_drop_panic() -> ! {
    rtabort!("Rust panics must be rethrown")
}

/// This function is called by the panic runtime if it catches an exception
/// object which does not correspond to a Rust panic.
#[cfg(not(test))]
#[rustc_std_internal_symbol]
extern "C" fn __rust_foreign_exception() -> ! {
    rtabort!("Rust cannot catch foreign exceptions")
}

#[doc(hidden)]
#[cfg(not(test))]
#[cfg(panic = "immediate-abort")]
pub mod panic_count {
    /// A reason for forcing an immediate abort on panic.
    #[derive(Debug)]
    pub enum MustAbort {
        AlwaysAbort,
        PanicInHook,
    }

    #[inline]
    pub fn increase(run_panic_hook: bool) -> Option<MustAbort> {
        None
    }

    #[inline]
    pub fn finished_panic_hook() {}

    #[inline]
    pub fn decrease() {}

    #[inline]
    pub fn set_always_abort() {}

    // Disregards ALWAYS_ABORT_FLAG
    #[inline]
    #[must_use]
    pub fn get_count() -> usize {
        0
    }

    #[must_use]
    #[inline]
    pub fn count_is_zero() -> bool {
        true
    }
}

#[doc(hidden)]
#[cfg(not(test))]
#[cfg(not(panic = "immediate-abort"))]
pub mod panic_count {
    use core::sync::atomic::{AtomicUsize, Ordering};

    const ALWAYS_ABORT_FLAG: usize = 1 << (usize::BITS - 1);

    /// A reason for forcing an immediate abort on panic.
    #[derive(Debug)]
    pub enum MustAbort {
        AlwaysAbort,
        PanicInHook,
    }

    // Panic count for the current thread and whether a panic hook is currently
    // being executed..
    // thread_local! {
    //     static LOCAL_PANIC_COUNT: Cell<(usize, bool)> = const { Cell::new((0, false)) }
    // }
    // TODO: Make this thread local
    // static LOCAL_PANIC_COUNT: Cell<(usize, bool)> = const { Cell::new((0, false)) };

    // Sum of panic counts from all threads. The purpose of this is to have
    // a fast path in `count_is_zero` (which is used by `panicking`). In any particular
    // thread, if that thread currently views `GLOBAL_PANIC_COUNT` as being zero,
    // then `LOCAL_PANIC_COUNT` in that thread is zero. This invariant holds before
    // and after increase and decrease, but not necessarily during their execution.
    //
    // Additionally, the top bit of GLOBAL_PANIC_COUNT (GLOBAL_ALWAYS_ABORT_FLAG)
    // records whether panic::always_abort() has been called. This can only be
    // set, never cleared.
    // panic::always_abort() is usually called to prevent memory allocations done by
    // the panic handling in the child created by `libc::fork`.
    // Memory allocations performed in a child created with `libc::fork` are undefined
    // behavior in most operating systems.
    // Accessing LOCAL_PANIC_COUNT in a child created by `libc::fork` would lead to a memory
    // allocation. Only GLOBAL_PANIC_COUNT can be accessed in this situation. This is
    // sufficient because a child process will always have exactly one thread only.
    // See also #85261 for details.
    //
    // This could be viewed as a struct containing a single bit and an n-1-bit
    // value, but if we wrote it like that it would be more than a single word,
    // and even a newtype around usize would be clumsy because we need atomics.
    // But we use such a tuple for the return type of increase().
    //
    // Stealing a bit is fine because it just amounts to assuming that each
    // panicking thread consumes at least 2 bytes of address space.
    static GLOBAL_PANIC_COUNT: AtomicUsize = AtomicUsize::new(0);

    // Increases the global and local panic count, and returns whether an
    // immediate abort is required.
    //
    // This also updates thread-local state to keep track of whether a panic
    // hook is currently executing.
    #[must_use = "MustAbort may not be ignored"]
    pub fn increase(_run_panic_hook: bool) -> Option<MustAbort> {
        let global_count = GLOBAL_PANIC_COUNT.fetch_add(1, Ordering::Relaxed);
        if global_count & ALWAYS_ABORT_FLAG != 0 {
            // Do *not* access thread-local state, we might be after a `fork`.
            return Some(MustAbort::AlwaysAbort);
        }

        None

        // LOCAL_PANIC_COUNT.with(|c| {
        //     let (count, in_panic_hook) = c.get();
        //     if in_panic_hook {
        //         return Some(MustAbort::PanicInHook);
        //     }
        //     c.set((count + 1, run_panic_hook));
        //     None
        // })
    }

    pub fn finished_panic_hook() {
        // LOCAL_PANIC_COUNT.with(|c| {
        //     let (count, _) = c.get();
        //     c.set((count, false));
        // });
    }

    pub fn decrease() {
        GLOBAL_PANIC_COUNT.fetch_sub(1, Ordering::Relaxed);
        // LOCAL_PANIC_COUNT.with(|c| {
        //     let (count, _) = c.get();
        //     c.set((count - 1, false));
        // });
    }

    pub fn set_always_abort() {
        GLOBAL_PANIC_COUNT.fetch_or(ALWAYS_ABORT_FLAG, Ordering::Relaxed);
    }

    // Disregards ALWAYS_ABORT_FLAG
    #[must_use]
    pub fn get_count() -> usize {
        GLOBAL_PANIC_COUNT.load(Ordering::Relaxed)
        // LOCAL_PANIC_COUNT.with(|c| c.get().0)
    }

    // Disregards ALWAYS_ABORT_FLAG
    #[must_use]
    #[inline]
    pub fn count_is_zero() -> bool {
        if GLOBAL_PANIC_COUNT.load(Ordering::Relaxed) & !ALWAYS_ABORT_FLAG == 0 {
            // Fast path: if `GLOBAL_PANIC_COUNT` is zero, all threads
            // (including the current one) will have `LOCAL_PANIC_COUNT`
            // equal to zero, so TLS access can be avoided.
            //
            // In terms of performance, a relaxed atomic load is similar to a normal
            // aligned memory read (e.g., a mov instruction in x86), but with some
            // compiler optimization restrictions. On the other hand, a TLS access
            // might require calling a non-inlinable function (such as `__tls_get_addr`
            // when using the GD TLS model).
            true
        } else {
            is_zero_slow_path()
        }
    }

    // Slow path is in a separate function to reduce the amount of code
    // inlined from `count_is_zero`.
    #[cold]
    #[inline(never)]
    fn is_zero_slow_path() -> bool {
        GLOBAL_PANIC_COUNT.load(Ordering::Relaxed) == 0
        // LOCAL_PANIC_COUNT.with(|c| c.get().0 == 0)
    }
}

#[cfg(all(feature = "std", not(target_os = "psp")))]
pub use std::panic::catch_unwind;

/// Invoke a closure, capturing the cause of an unwinding panic if one occurs.
#[cfg(not(feature = "std"))]
#[cfg(panic = "immediate-abort")]
pub fn catch_unwind<R, F: FnOnce() -> R>(f: F) -> Result<R, Box<dyn Any + Send>> {
    Ok(f())
}

/// Invoke a closure, capturing the cause of an unwinding panic if one occurs.
#[cfg(not(feature = "std"))]
#[cfg(not(panic = "immediate-abort"))]
pub fn catch_unwind<R, F: FnOnce() -> R>(f: F) -> Result<R, Box<dyn Any + Send>> {
    union Data<F, R> {
        f: ManuallyDrop<F>,
        r: ManuallyDrop<R>,
        p: ManuallyDrop<Box<dyn Any + Send>>,
    }

    // We do some sketchy operations with ownership here for the sake of
    // performance. We can only pass pointers down to `do_call` (can't pass
    // objects by value), so we do all the ownership tracking here manually
    // using a union.
    //
    // We go through a transition where:
    //
    // * First, we set the data field `f` to be the argumentless closure that we're going to call.
    // * When we make the function call, the `do_call` function below, we take ownership of the
    //   function pointer. At this point the `data` union is entirely uninitialized.
    // * If the closure successfully returns, we write the return value into the data's return slot
    //   (field `r`).
    // * If the closure panics (`do_catch` below), we write the panic payload into field `p`.
    // * Finally, when we come back out of the `try` intrinsic we're in one of two states:
    //
    //      1. The closure didn't panic, in which case the return value was filled in. We move it
    //         out of `data.r` and return it.
    //      2. The closure panicked, in which case the panic payload was filled in. We move it out
    //         of `data.p` and return it.
    //
    // Once we stack all that together we should have the "most efficient'
    // method of calling a catch panic whilst juggling ownership.
    let mut data = Data {
        f: ManuallyDrop::new(f),
    };

    // SAFETY:
    //
    // Access to the union's fields: this is `std` and we know that the `catch_unwind`
    // intrinsic fills in the `r` or `p` union field based on its return value.
    //
    // The call to `intrinsics::catch_unwind` is made safe by:
    // - `do_call`, the first argument, can be called with the initial `data_ptr`.
    // - `do_catch`, the second argument, can be called with the `data_ptr` as well.
    // See their safety preconditions for more information
    unsafe {
        return if intrinsics::catch_unwind(do_call, &raw mut data, do_catch) {
            Err(ManuallyDrop::into_inner(data.p))
        } else {
            Ok(ManuallyDrop::into_inner(data.r))
        };
    }

    // We consider unwinding to be rare, so mark this function as cold. However,
    // do not mark it no-inline -- that decision is best to leave to the
    // optimizer (in most cases this function is not inlined even as a normal,
    // non-cold function, though, as of the writing of this comment).
    #[cold]
    // #[optimize(size)]
    unsafe fn cleanup(payload: *mut u8) -> Box<dyn Any + Send + 'static> {
        // SAFETY: The whole unsafe block hinges on a correct implementation of
        // the panic handler `__rust_panic_cleanup`. As such we can only
        // assume it returns the correct thing for `Box::from_raw` to work
        // without undefined behavior.
        let obj = unsafe { Box::from_raw(__rust_panic_cleanup(payload)) };
        panic_count::decrease();
        obj
    }

    // SAFETY:
    // data must be non-NUL, correctly aligned, and a pointer to a `Data<F, R>`
    // Its must contains a valid `f` (type: F) value that can be use to fill
    // `data.r`.
    #[inline]
    unsafe fn do_call<F: FnOnce() -> R, R>(data: *mut Data<F, R>) {
        // SAFETY: this is the responsibility of the caller, see above.
        unsafe {
            let f = ManuallyDrop::take(&mut (*data).f);
            (*data).r = ManuallyDrop::new(f());
        }
    }

    // We *do* want this part of the catch to be inlined: this allows the
    // compiler to properly track accesses to the Data union and optimize it
    // away most of the time.
    //
    // SAFETY:
    // data must be non-NUL, correctly aligned, and a pointer to a `Data<F, R>`
    // Since this uses `cleanup` it also hinges on a correct implementation of
    // `__rustc_panic_cleanup`.
    #[inline]
    #[rustc_nounwind] // `intrinsic::catch_unwind` requires catch fn to be nounwind
    unsafe fn do_catch<F: FnOnce() -> R, R>(data: *mut Data<F, R>, payload: *mut u8) {
        // SAFETY: this is the responsibility of the caller, see above.
        //
        // When `__rustc_panic_cleaner` is correctly implemented we can rely
        // on `obj` being the correct thing to pass to `data.p` (after wrapping
        // in `ManuallyDrop`).
        unsafe {
            let obj = cleanup(payload);
            (*data).p = ManuallyDrop::new(obj);
        }
    }
}

/// Determines whether the current thread is unwinding because of panic.
#[inline]
pub fn panicking() -> bool {
    !panic_count::count_is_zero()
}

/// Entry point of panics from the core crate (`panic_impl` lang item).
#[cfg(not(feature = "std"))]
#[cfg(not(any(test, doctest)))]
#[panic_handler]
pub fn panic_handler(info: &core::panic::PanicInfo<'_>) -> ! {
    struct FormatStringPayload<'a> {
        inner: &'a core::panic::PanicMessage<'a>,
        string: Option<String>,
    }

    impl FormatStringPayload<'_> {
        fn fill(&mut self) -> &mut String {
            let inner = self.inner;
            // Lazily, the first time this gets called, run the actual string formatting.
            self.string.get_or_insert_with(|| alloc::format!("{inner}"))
        }
    }

    unsafe impl PanicPayload for FormatStringPayload<'_> {
        fn take_box(&mut self) -> *mut (dyn Any + Send) {
            // We do two allocations here, unfortunately. But (a) they're required with the current
            // scheme, and (b) we don't handle panic + OOM properly anyway (see comment in
            // begin_panic below).
            let contents = mem::take(self.fill());
            Box::into_raw(Box::new(contents))
        }

        fn get(&mut self) -> &(dyn Any + Send) {
            self.fill()
        }
    }

    impl fmt::Display for FormatStringPayload<'_> {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            if let Some(s) = &self.string {
                f.write_str(s)
            } else {
                fmt::Display::fmt(&self.inner, f)
            }
        }
    }

    struct StaticStrPayload(&'static str);

    unsafe impl PanicPayload for StaticStrPayload {
        fn take_box(&mut self) -> *mut (dyn Any + Send) {
            Box::into_raw(Box::new(self.0))
        }

        fn get(&mut self) -> &(dyn Any + Send) {
            &self.0
        }

        fn as_str(&mut self) -> Option<&str> {
            Some(self.0)
        }
    }

    impl fmt::Display for StaticStrPayload {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            f.write_str(self.0)
        }
    }

    let loc = info.location().unwrap(); // The current implementation always returns Some
    let msg = info.message();
    // crate::sys::backtrace::__rust_end_short_backtrace(move || {
    //     if let Some(s) = msg.as_str() {
    //         panic_with_hook(
    //             &mut StaticStrPayload(s),
    //             loc,
    //             info.can_unwind(),
    //             info.force_no_backtrace(),
    //         );
    //     } else {
    //         panic_with_hook(
    //             &mut FormatStringPayload {
    //                 inner: &msg,
    //                 string: None,
    //             },
    //             loc,
    //             info.can_unwind(),
    //             info.force_no_backtrace(),
    //         );
    //     }
    // })

    if let Some(s) = msg.as_str() {
        panic_with_hook(
            &mut StaticStrPayload(s),
            loc,
            true,  // info.can_unwind(),
            false, // info.force_no_backtrace(),
        );
    } else {
        panic_with_hook(
            &mut FormatStringPayload {
                inner: &msg,
                string: None,
            },
            loc,
            true,  // info.can_unwind(),
            false, // info.force_no_backtrace(),
        );
    }
}

/// This is the entry point of panicking for the non-format-string variants of
/// panic!() and assert!(). In particular, this is the only entry point that supports
/// arbitrary payloads, not just format strings.
#[cfg_attr(not(any(test, doctest)), lang = "begin_panic")]
// lang item for CTFE panic support
// never inline unless panic=immediate-abort to avoid code
// bloat at the call sites as much as possible
#[cfg_attr(not(panic = "immediate-abort"), inline(never), cold)]
#[cfg_attr(panic = "immediate-abort", inline)]
#[track_caller]
pub fn begin_panic<M: Any + Send>(msg: M) -> ! {
    if cfg!(panic = "immediate-abort") {
        process::abort()
    }

    struct Payload<A> {
        inner: Option<A>,
    }

    unsafe impl<A: Send + 'static> PanicPayload for Payload<A> {
        fn take_box(&mut self) -> *mut (dyn Any + Send) {
            // Note that this should be the only allocation performed in this code path. Currently
            // this means that panic!() on OOM will invoke this code path, but then again we're not
            // really ready for panic on OOM anyway. If we do start doing this, then we should
            // propagate this allocation to be performed in the parent of this thread instead of the
            // thread that's panicking.
            let data = match self.inner.take() {
                Some(a) => Box::new(a) as Box<dyn Any + Send>,
                None => process::abort(),
            };
            Box::into_raw(data)
        }

        fn get(&mut self) -> &(dyn Any + Send) {
            match self.inner {
                Some(ref a) => a,
                None => process::abort(),
            }
        }
    }

    impl<A: 'static> fmt::Display for Payload<A> {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            match &self.inner {
                Some(a) => f.write_str(payload_as_str(a)),
                None => process::abort(),
            }
        }
    }

    let loc = Location::caller();
    // crate::sys::backtrace::__rust_end_short_backtrace(move || {
    //     panic_with_hook(
    //         &mut Payload { inner: Some(msg) },
    //         loc,
    //         // can_unwind
    //         true,
    //         // force_no_backtrace
    //         false,
    //     )
    // })

    panic_with_hook(
        &mut Payload { inner: Some(msg) },
        loc,
        // can_unwind
        true,
        // force_no_backtrace
        false,
    )
}

fn payload_as_str(payload: &dyn Any) -> &str {
    if let Some(&s) = payload.downcast_ref::<&'static str>() {
        s
    } else if let Some(s) = payload.downcast_ref::<String>() {
        s.as_str()
    } else {
        "Box<dyn Any>"
    }
}

/// Central point for dispatching panics.
///
/// Executes the primary logic for a panic, including checking for recursive
/// panics, panic hooks, and finally dispatching to the panic runtime to either
/// abort or unwind.
fn panic_with_hook(
    payload: &mut dyn PanicPayload, location: &'static Location<'static>, can_unwind: bool,
    _force_no_backtrace: bool,
) -> ! {
    let must_abort = panic_count::increase(true);

    // Check if we need to abort immediately.
    if let Some(must_abort) = must_abort {
        match must_abort {
            panic_count::MustAbort::PanicInHook => {
                // Don't try to format the message in this case, perhaps that is causing the
                // recursive panics. However if the message is just a string, no user-defined
                // code is involved in printing it, so that is risk-free.
                let message: &str = payload.as_str().unwrap_or_default();
                rtprintpanic!(
                    "panicked at {location}:\n{message}\nthread panicked while processing panic. \
                     aborting.\n"
                );
            },
            panic_count::MustAbort::AlwaysAbort => {
                // Unfortunately, this does not print a backtrace, because creating
                // a `Backtrace` will allocate, which we must avoid here.
                rtprintpanic!("aborting due to panic at {location}:\n{payload}\n");
            },
        }
        crate::process::abort();
    }

    // Indicate that we have finished executing the panic hook. After this point
    // it is fine if there is a panic while executing destructors, as long as it
    // it contained within a `catch_unwind`.
    panic_count::finished_panic_hook();

    if !can_unwind {
        // If a thread panics while running destructors or tries to unwind
        // through a nounwind function (e.g. extern "C") then we cannot continue
        // unwinding and have to abort immediately.
        rtprintpanic!("thread caused non-unwinding panic. aborting.\n");
        crate::process::abort();
    }

    let panics = panic_count::get_count();

    if panics > 1 {
        rtabort!("thread panicked while processing panic. aborting.")
    }


    rust_panic(payload)
}

/// This is the entry point for `resume_unwind`.
/// It just forwards the payload to the panic runtime.
#[cfg_attr(panic = "immediate-abort", inline)]
pub fn resume_unwind(payload: Box<dyn Any + Send>) -> ! {
    if let Some(must_abort) = panic_count::increase(false) {
        match must_abort {
            panic_count::MustAbort::PanicInHook => {
                rtprintpanic!("thread panicked while processing panic. aborting.\n");
            },
            panic_count::MustAbort::AlwaysAbort => {
                rtprintpanic!("aborting due to panic\n");
            },
        }

        crate::process::abort();
    }

    struct RewrapBox(Box<dyn Any + Send>);

    unsafe impl PanicPayload for RewrapBox {
        fn take_box(&mut self) -> *mut (dyn Any + Send) {
            Box::into_raw(mem::replace(&mut self.0, Box::new(())))
        }

        fn get(&mut self) -> &(dyn Any + Send) {
            &*self.0
        }
    }

    impl fmt::Display for RewrapBox {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            f.write_str(payload_as_str(&self.0))
        }
    }

    rust_panic(&mut RewrapBox(payload))
}

/// A function with a fixed suffix (through `rustc_std_internal_symbol`)
/// on which to slap yer breakpoints.
#[inline(never)]
#[cfg_attr(not(test), rustc_std_internal_symbol)]
#[cfg(not(panic = "immediate-abort"))]
#[cfg(not(feature = "std"))]
fn rust_panic(msg: &mut dyn PanicPayload) -> ! {
    let code = unsafe { __rust_start_panic(msg) };

    rtabort!("failed to initiate panic, error {code}")
}

#[cfg_attr(not(test), rustc_std_internal_symbol)]
#[cfg(panic = "immediate-abort")]
#[cfg(not(feature = "std"))]
fn rust_panic(_: &mut dyn PanicPayload) -> ! {
    crate::process::abort();
}

pub(crate) struct AssertUnwindSafe<T>(pub T);
impl<T> core::panic::UnwindSafe for AssertUnwindSafe<T> {}

// TODO: EH personality was moved from the panic_unwind crate to std in
// https://github.com/rust-lang/rust/pull/92845. This no-op implementation
// should be replaced with the version from std when using no_std.
#[cfg(not(feature = "std"))]
#[lang = "eh_personality"]
unsafe extern "C" fn rust_eh_personality() {}

#[cfg_attr(panic = "unwind", link(name = "unwind", kind = "static"))]
unsafe extern "C" {}

/// These symbols and functions should not actually be used. `libunwind`,
/// however, requires them to be present so that it can link.
// TODO: Patch these out of libunwind instead.
#[cfg(all(target_os = "psp", feature = "non-stub-code", not(panic = "immediate-abort")))]
mod libunwind_shims {
    #[unsafe(no_mangle)]
    unsafe extern "C" fn fprintf(_stream: *const u8, _format: *const u8, _: ...) -> isize {
        -1
    }

    #[unsafe(no_mangle)]
    unsafe extern "C" fn fflush(_stream: *const u8) -> i32 {
        -1
    }

    #[unsafe(no_mangle)]
    #[allow(deprecated)]
    unsafe extern "C" fn abort() {
        // loop {
        // crate::sys::spin_loop();
        // }
        crate::process::abort()
    }

    #[unsafe(no_mangle)]
    unsafe extern "C" fn malloc(size: usize) -> *mut u8 {
        use alloc::alloc::{alloc, Layout};

        let size = size + 4;

        unsafe {
            let data = alloc(Layout::from_size_align_unchecked(size, 4));
            *(data as *mut usize) = size;

            data.offset(4)
        }
    }


    #[unsafe(no_mangle)]
    unsafe extern "C" fn free(data: *mut u8) {
        use alloc::alloc::{dealloc, Layout};

        unsafe {
            let base = data.sub(4);
            let size = *(base as *mut usize);

            dealloc(base, Layout::from_size_align_unchecked(size, 4));
        }
    }

    #[unsafe(no_mangle)]
    unsafe extern "C" fn getenv(_name: *const u8) -> *const u8 {
        core::ptr::null()
    }

    #[unsafe(no_mangle)]
    unsafe extern "C" fn __assert_func(_: *const u8, _: i32, _: *const u8, _: *const u8) {}

    #[unsafe(no_mangle)]
    static _impure_ptr: [usize; 0] = [];
}