chore: add vendor directory

11 files changed, 572 insertions, 0 deletions

diff --git a/vendor/stacker/src/alloc_stack_restore_guard.rs b/vendor/stacker/src/alloc_stack_restore_guard.rs
new file mode 100644
index 00000000..ef2babb7
--- /dev/null
+++ b/vendor/stacker/src/alloc_stack_restore_guard.rs
@@ -0,0 +1,47 @@
+use crate::{get_stack_limit, set_stack_limit};
+
+pub struct StackRestoreGuard {
+    new_stack: *mut u8,
+    stack_bytes: usize,
+    old_stack_limit: Option<usize>,
+}
+
+const ALIGNMENT: usize = 16;
+
+impl StackRestoreGuard {
+    pub fn new(stack_bytes: usize) -> StackRestoreGuard {
+        // On these platforms we do not use stack guards. this is very unfortunate,
+        // but there is not much we can do about it without OS support.
+        // We simply allocate the requested size from the global allocator with a suitable
+        // alignment.
+        let stack_bytes = stack_bytes
+            .checked_add(ALIGNMENT - 1)
+            .expect("unreasonably large stack requested")
+            / ALIGNMENT
+            * ALIGNMENT;
+        let layout = std::alloc::Layout::from_size_align(stack_bytes, ALIGNMENT).unwrap();
+        let ptr = unsafe { std::alloc::alloc(layout) };
+        assert!(!ptr.is_null(), "unable to allocate stack");
+        StackRestoreGuard {
+            new_stack: ptr,
+            stack_bytes,
+            old_stack_limit: get_stack_limit(),
+        }
+    }
+
+    pub fn stack_area(&self) -> (*mut u8, usize) {
+        (self.new_stack, self.stack_bytes)
+    }
+}
+
+impl Drop for StackRestoreGuard {
+    fn drop(&mut self) {
+        unsafe {
+            std::alloc::dealloc(
+                self.new_stack,
+                std::alloc::Layout::from_size_align_unchecked(self.stack_bytes, ALIGNMENT),
+            );
+        }
+        set_stack_limit(self.old_stack_limit);
+    }
+}
diff --git a/vendor/stacker/src/arch/asm.h b/vendor/stacker/src/arch/asm.h
new file mode 100644
index 00000000..56c9d289
--- /dev/null
+++ b/vendor/stacker/src/arch/asm.h
@@ -0,0 +1,5 @@
+#if defined(APPLE) || (defined(WINDOWS) && defined(X86))
+#define GLOBAL(name) .globl _ ## name; _ ## name
+#else
+#define GLOBAL(name) .globl name; name
+#endif
diff --git a/vendor/stacker/src/arch/windows.c b/vendor/stacker/src/arch/windows.c
new file mode 100644
index 00000000..89485a0c
--- /dev/null
+++ b/vendor/stacker/src/arch/windows.c
@@ -0,0 +1,5 @@
+#include <windows.h>

+

+PVOID __stacker_get_current_fiber() {

+    return GetCurrentFiber();

+}

diff --git a/vendor/stacker/src/backends/fallback.rs b/vendor/stacker/src/backends/fallback.rs
new file mode 100644
index 00000000..a812cbc9
--- /dev/null
+++ b/vendor/stacker/src/backends/fallback.rs
@@ -0,0 +1,4 @@
+#[inline(always)]
+pub unsafe fn guess_os_stack_limit() -> Option<usize> {
+    None
+}
diff --git a/vendor/stacker/src/backends/macos.rs b/vendor/stacker/src/backends/macos.rs
new file mode 100644
index 00000000..42b28516
--- /dev/null
+++ b/vendor/stacker/src/backends/macos.rs
@@ -0,0 +1,6 @@
+pub unsafe fn guess_os_stack_limit() -> Option<usize> {
+    Some(
+        libc::pthread_get_stackaddr_np(libc::pthread_self()) as usize
+            - libc::pthread_get_stacksize_np(libc::pthread_self()) as usize,
+    )
+}
diff --git a/vendor/stacker/src/backends/mod.rs b/vendor/stacker/src/backends/mod.rs
new file mode 100644
index 00000000..8da895d6
--- /dev/null
+++ b/vendor/stacker/src/backends/mod.rs
@@ -0,0 +1,28 @@
+cfg_if! {
+    if #[cfg(miri)] {
+        mod fallback;
+        pub use fallback::guess_os_stack_limit;
+    } else if #[cfg(windows)] {
+        pub(crate) mod windows;
+        pub use windows::guess_os_stack_limit;
+    } else if #[cfg(any(
+        target_os = "linux",
+        target_os = "solaris",
+        target_os = "netbsd",
+        target_os = "freebsd",
+        target_os = "dragonfly",
+        target_os = "illumos"
+    ))] {
+        mod unix;
+        pub use unix::guess_os_stack_limit;
+    } else if #[cfg(target_os = "openbsd")] {
+        mod openbsd;
+        pub use openbsd::guess_os_stack_limit;
+    } else if #[cfg(target_os = "macos")] {
+        mod macos;
+        pub use macos::guess_os_stack_limit;
+    } else {
+        mod fallback;
+        pub use fallback::guess_os_stack_limit;
+    }
+}
diff --git a/vendor/stacker/src/backends/openbsd.rs b/vendor/stacker/src/backends/openbsd.rs
new file mode 100644
index 00000000..ee582d84
--- /dev/null
+++ b/vendor/stacker/src/backends/openbsd.rs
@@ -0,0 +1,9 @@
+pub unsafe fn guess_os_stack_limit() -> Option<usize> {
+    let mut stackinfo = std::mem::MaybeUninit::<libc::stack_t>::uninit();
+    let res = libc::pthread_stackseg_np(libc::pthread_self(), stackinfo.as_mut_ptr());
+    if res != 0 {
+        return None;
+    }
+    let stackinfo = stackinfo.assume_init();
+    Some(stackinfo.ss_sp as usize - stackinfo.ss_size)
+}
diff --git a/vendor/stacker/src/backends/unix.rs b/vendor/stacker/src/backends/unix.rs
new file mode 100644
index 00000000..97ef209f
--- /dev/null
+++ b/vendor/stacker/src/backends/unix.rs
@@ -0,0 +1,40 @@
+#[cfg(any(target_os = "freebsd", target_os = "dragonfly", target_os = "illumos"))]
+use libc::pthread_attr_get_np as get_attr;
+#[cfg(any(target_os = "linux", target_os = "solaris", target_os = "netbsd"))]
+use libc::pthread_getattr_np as get_attr;
+
+pub unsafe fn guess_os_stack_limit() -> Option<usize> {
+    let mut attr = PthreadAttr::new()?;
+    (get_attr(libc::pthread_self(), &mut attr.0) == 0).then_some(())?;
+    let mut stackaddr = std::ptr::null_mut();
+    let mut stacksize = 0;
+    (libc::pthread_attr_getstack(&attr.0, &mut stackaddr, &mut stacksize) == 0).then_some(())?;
+    Some(stackaddr as usize)
+}
+
+struct PthreadAttr(libc::pthread_attr_t);
+
+impl Drop for PthreadAttr {
+    fn drop(&mut self) {
+        unsafe {
+            let ret = libc::pthread_attr_destroy(&mut self.0);
+            if ret != 0 {
+                let err = std::io::Error::last_os_error();
+                panic!(
+                    "pthread_attr_destroy failed with error code {}: {}",
+                    ret, err
+                );
+            }
+        }
+    }
+}
+
+impl PthreadAttr {
+    unsafe fn new() -> Option<Self> {
+        let mut attr = std::mem::MaybeUninit::<libc::pthread_attr_t>::uninit();
+        if libc::pthread_attr_init(attr.as_mut_ptr()) != 0 {
+            return None;
+        }
+        Some(PthreadAttr(attr.assume_init()))
+    }
+}
diff --git a/vendor/stacker/src/backends/windows.rs b/vendor/stacker/src/backends/windows.rs
new file mode 100644
index 00000000..69c76133
--- /dev/null
+++ b/vendor/stacker/src/backends/windows.rs
@@ -0,0 +1,142 @@
+use libc::c_void;
+use std::io;
+use std::ptr;
+use windows_sys::Win32::Foundation::BOOL;
+use windows_sys::Win32::System::Memory::VirtualQuery;
+use windows_sys::Win32::System::Threading::{
+    ConvertFiberToThread, ConvertThreadToFiber, CreateFiber, DeleteFiber, IsThreadAFiber,
+    SetThreadStackGuarantee, SwitchToFiber,
+};
+
+// Make sure the libstacker.a (implemented in C) is linked.
+// See https://github.com/rust-lang/rust/issues/65610
+#[link(name = "stacker")]
+extern "C" {
+    fn __stacker_get_current_fiber() -> *mut c_void;
+}
+
+struct FiberInfo<F> {
+    callback: std::mem::MaybeUninit<F>,
+    panic: Option<Box<dyn std::any::Any + Send + 'static>>,
+    parent_fiber: *mut c_void,
+}
+
+unsafe extern "system" fn fiber_proc<F: FnOnce()>(data: *mut c_void) {
+    // This function is the entry point to our inner fiber, and as argument we get an
+    // instance of `FiberInfo`. We will set-up the "runtime" for the callback and execute
+    // it.
+    let data = &mut *(data as *mut FiberInfo<F>);
+    let old_stack_limit = crate::get_stack_limit();
+    crate::set_stack_limit(guess_os_stack_limit());
+    let callback = data.callback.as_ptr();
+    data.panic = std::panic::catch_unwind(std::panic::AssertUnwindSafe(callback.read())).err();
+
+    // Restore to the previous Fiber
+    crate::set_stack_limit(old_stack_limit);
+    SwitchToFiber(data.parent_fiber);
+}
+
+pub fn _grow(stack_size: usize, callback: &mut dyn FnMut()) {
+    // Fibers (or stackful coroutines) is the only official way to create new stacks on the
+    // same thread on Windows. So in order to extend the stack we create fiber and switch
+    // to it so we can use it's stack. After running `callback` within our fiber, we switch
+    // back to the current stack and destroy the fiber and its associated stack.
+    unsafe {
+        let was_fiber = IsThreadAFiber() == 1 as BOOL;
+        let mut data = FiberInfo {
+            callback: std::mem::MaybeUninit::new(callback),
+            panic: None,
+            parent_fiber: {
+                if was_fiber {
+                    // Get a handle to the current fiber. We need to use a C implementation
+                    // for this as GetCurrentFiber is an header only function.
+                    __stacker_get_current_fiber()
+                } else {
+                    // Convert the current thread to a fiber, so we are able to switch back
+                    // to the current stack. Threads coverted to fibers still act like
+                    // regular threads, but they have associated fiber data. We later
+                    // convert it back to a regular thread and free the fiber data.
+                    ConvertThreadToFiber(ptr::null_mut())
+                }
+            },
+        };
+
+        if data.parent_fiber.is_null() {
+            panic!(
+                "unable to convert thread to fiber: {}",
+                io::Error::last_os_error()
+            );
+        }
+
+        let fiber = CreateFiber(
+            stack_size as usize,
+            Some(fiber_proc::<&mut dyn FnMut()>),
+            &mut data as *mut FiberInfo<&mut dyn FnMut()> as *mut _,
+        );
+        if fiber.is_null() {
+            panic!("unable to allocate fiber: {}", io::Error::last_os_error());
+        }
+
+        // Switch to the fiber we created. This changes stacks and starts executing
+        // fiber_proc on it. fiber_proc will run `callback` and then switch back to run the
+        // next statement.
+        SwitchToFiber(fiber);
+        DeleteFiber(fiber);
+
+        // Clean-up.
+        if !was_fiber && ConvertFiberToThread() == 0 {
+            // FIXME: Perhaps should not panic here?
+            panic!(
+                "unable to convert back to thread: {}",
+                io::Error::last_os_error()
+            );
+        }
+
+        if let Some(p) = data.panic {
+            std::panic::resume_unwind(p);
+        }
+    }
+}
+
+#[inline(always)]
+fn get_thread_stack_guarantee() -> Option<usize> {
+    let min_guarantee = if cfg!(target_pointer_width = "32") {
+        0x1000
+    } else {
+        0x2000
+    };
+    let mut stack_guarantee = 0;
+    unsafe {
+        // Read the current thread stack guarantee
+        // This is the stack reserved for stack overflow
+        // exception handling.
+        // This doesn't return the true value so we need
+        // some further logic to calculate the real stack
+        // guarantee. This logic is what is used on x86-32 and
+        // x86-64 Windows 10. Other versions and platforms may differ
+        let ret = SetThreadStackGuarantee(&mut stack_guarantee);
+        if ret == 0 {
+            return None;
+        }
+    };
+    Some(std::cmp::max(stack_guarantee, min_guarantee) as usize + 0x1000)
+}
+
+#[inline(always)]
+pub unsafe fn guess_os_stack_limit() -> Option<usize> {
+    // Query the allocation which contains our stack pointer in order
+    // to discover the size of the stack
+    //
+    // FIXME: we could read stack base from the TIB, specifically the 3rd element of it.
+    type QueryT = windows_sys::Win32::System::Memory::MEMORY_BASIC_INFORMATION;
+    let mut mi = std::mem::MaybeUninit::<QueryT>::uninit();
+    let res = VirtualQuery(
+        psm::stack_pointer() as *const _,
+        mi.as_mut_ptr(),
+        std::mem::size_of::<QueryT>() as usize,
+    );
+    if res == 0 {
+        return None;
+    }
+    Some(mi.assume_init().AllocationBase as usize + get_thread_stack_guarantee()? + 0x1000)
+}
diff --git a/vendor/stacker/src/lib.rs b/vendor/stacker/src/lib.rs
new file mode 100644
index 00000000..ee5803c3
--- /dev/null
+++ b/vendor/stacker/src/lib.rs
@@ -0,0 +1,181 @@
+//! A library to help grow the stack when it runs out of space.
+//!
+//! This is an implementation of manually instrumented segmented stacks where points in a program's
+//! control flow are annotated with "maybe grow the stack here". Each point of annotation indicates
+//! how far away from the end of the stack it's allowed to be, plus the amount of stack to allocate
+//! if it does reach the end.
+//!
+//! Once a program has reached the end of its stack, a temporary stack on the heap is allocated and
+//! is switched to for the duration of a closure.
+//!
+//! For a set of lower-level primitives, consider the `psm` crate.
+//!
+//! # Examples
+//!
+//! ```
+//! // Grow the stack if we are within the "red zone" of 32K, and if we allocate
+//! // a new stack allocate 1MB of stack space.
+//! //
+//! // If we're already in bounds, just run the provided closure on current stack.
+//! stacker::maybe_grow(32 * 1024, 1024 * 1024, || {
+//!     // guaranteed to have at least 32K of stack
+//! });
+//! ```
+
+#![allow(improper_ctypes)]
+
+#[macro_use]
+extern crate cfg_if;
+extern crate libc;
+#[cfg(windows)]
+extern crate windows_sys;
+#[macro_use]
+extern crate psm;
+
+mod backends;
+
+use std::cell::Cell;
+
+/// Grows the call stack if necessary.
+///
+/// This function is intended to be called at manually instrumented points in a program where
+/// recursion is known to happen quite a bit. This function will check to see if we're within
+/// `red_zone` bytes of the end of the stack, and if so it will allocate a new stack of at least
+/// `stack_size` bytes.
+///
+/// The closure `f` is guaranteed to run on a stack with at least `red_zone` bytes, and it will be
+/// run on the current stack if there's space available.
+#[inline(always)]
+pub fn maybe_grow<R, F: FnOnce() -> R>(red_zone: usize, stack_size: usize, callback: F) -> R {
+    // if we can't guess the remaining stack (unsupported on some platforms) we immediately grow
+    // the stack and then cache the new stack size (which we do know now because we allocated it.
+    let enough_space = match remaining_stack() {
+        Some(remaining) => remaining >= red_zone,
+        None => false,
+    };
+    if enough_space {
+        callback()
+    } else {
+        grow(stack_size, callback)
+    }
+}
+
+/// Always creates a new stack for the passed closure to run on.
+/// The closure will still be on the same thread as the caller of `grow`.
+/// This will allocate a new stack with at least `stack_size` bytes.
+pub fn grow<R, F: FnOnce() -> R>(stack_size: usize, callback: F) -> R {
+    // To avoid monomorphizing `_grow()` and everything it calls,
+    // we convert the generic callback to a dynamic one.
+    let mut opt_callback = Some(callback);
+    let mut ret = None;
+    let ret_ref = &mut ret;
+
+    // This wrapper around `callback` achieves two things:
+    // * It converts the `impl FnOnce` to a `dyn FnMut`.
+    //   `dyn` because we want it to not be generic, and
+    //   `FnMut` because we can't pass a `dyn FnOnce` around without boxing it.
+    // * It eliminates the generic return value, by writing it to the stack of this function.
+    //   Otherwise the closure would have to return an unsized value, which isn't possible.
+    let dyn_callback: &mut dyn FnMut() = &mut || {
+        let taken_callback = opt_callback.take().unwrap();
+        *ret_ref = Some(taken_callback());
+    };
+
+    _grow(stack_size, dyn_callback);
+    ret.unwrap()
+}
+
+/// Queries the amount of remaining stack as interpreted by this library.
+///
+/// This function will return the amount of stack space left which will be used
+/// to determine whether a stack switch should be made or not.
+pub fn remaining_stack() -> Option<usize> {
+    let current_ptr = current_stack_ptr();
+    get_stack_limit().map(|limit| current_ptr.saturating_sub(limit))
+}
+
+psm_stack_information!(
+    yes {
+        fn current_stack_ptr() -> usize {
+            psm::stack_pointer() as usize
+        }
+    }
+    no {
+        #[inline(always)]
+        fn current_stack_ptr() -> usize {
+            unsafe {
+                let mut x = std::mem::MaybeUninit::<u8>::uninit();
+                // Unlikely to be ever exercised. As a fallback we execute a volatile read to a
+                // local (to hopefully defeat the optimisations that would make this local a static
+                // global) and take its address. This way we get a very approximate address of the
+                // current frame.
+                x.as_mut_ptr().write_volatile(42);
+                x.as_ptr() as usize
+            }
+        }
+    }
+);
+
+thread_local! {
+    static STACK_LIMIT: Cell<Option<usize>> = Cell::new(unsafe {
+        backends::guess_os_stack_limit()
+    })
+}
+
+#[inline(always)]
+fn get_stack_limit() -> Option<usize> {
+    STACK_LIMIT.with(|s| s.get())
+}
+
+#[inline(always)]
+#[allow(unused)]
+fn set_stack_limit(l: Option<usize>) {
+    STACK_LIMIT.with(|s| s.set(l))
+}
+
+psm_stack_manipulation! {
+    yes {
+        #[cfg(not(any(target_arch = "wasm32",target_os = "hermit")))]
+        #[path = "mmap_stack_restore_guard.rs"]
+        mod stack_restore_guard;
+
+        #[cfg(any(target_arch = "wasm32",target_os = "hermit"))]
+        #[path = "alloc_stack_restore_guard.rs"]
+        mod stack_restore_guard;
+
+        use stack_restore_guard::StackRestoreGuard;
+
+        fn _grow(requested_stack_size: usize, callback: &mut dyn FnMut()) {
+            // Other than that this code has no meaningful gotchas.
+            unsafe {
+                // We use a guard pattern to ensure we deallocate the allocated stack when we leave
+                // this function and also try to uphold various safety invariants required by `psm`
+                // (such as not unwinding from the callback we pass to it).
+                // `StackRestoreGuard` allocates a memory area with suitable size and alignment.
+                // It also sets up stack guards if supported on target.
+                let guard = StackRestoreGuard::new(requested_stack_size);
+                let (stack_base, allocated_stack_size) = guard.stack_area();
+                debug_assert!(allocated_stack_size >= requested_stack_size);
+                set_stack_limit(Some(stack_base as usize));
+                // TODO should we not pass `allocated_stack_size` here?
+                let panic = psm::on_stack(stack_base, requested_stack_size, move || {
+                    std::panic::catch_unwind(std::panic::AssertUnwindSafe(callback)).err()
+                });
+                drop(guard);
+                if let Some(p) = panic {
+                    std::panic::resume_unwind(p);
+                }
+            }
+        }
+    }
+
+    no {
+        #[cfg(not(windows))]
+        fn _grow(stack_size: usize, callback: &mut dyn FnMut()) {
+            let _ = stack_size;
+            callback();
+        }
+        #[cfg(windows)]
+        use backends::windows::_grow;
+    }
+}
diff --git a/vendor/stacker/src/mmap_stack_restore_guard.rs b/vendor/stacker/src/mmap_stack_restore_guard.rs
new file mode 100644
index 00000000..1e021c2d
--- /dev/null
+++ b/vendor/stacker/src/mmap_stack_restore_guard.rs
@@ -0,0 +1,105 @@
+use crate::{get_stack_limit, set_stack_limit};
+
+pub struct StackRestoreGuard {
+    mapping: *mut u8,
+    size_with_guard: usize,
+    page_size: usize,
+    old_stack_limit: Option<usize>,
+}
+
+impl StackRestoreGuard {
+    pub fn new(requested_size: usize) -> StackRestoreGuard {
+        // For maximum portability we want to produce a stack that is aligned to a page and has
+        // a size that’s a multiple of page size. It is natural to use mmap to allocate
+        // these pages. Furthermore, we want to allocate two extras pages for the stack guard.
+        // To achieve that we do our calculations in number of pages and convert to bytes last.
+        let page_size = page_size();
+        let requested_pages = requested_size
+            .checked_add(page_size - 1)
+            .expect("unreasonably large stack requested")
+            / page_size;
+        let page_count_with_guard = std::cmp::max(1, requested_pages) + 2;
+        let size_with_guard = page_count_with_guard
+            .checked_mul(page_size)
+            .expect("unreasonably large stack requested");
+
+        unsafe {
+            let new_stack = libc::mmap(
+                std::ptr::null_mut(),
+                size_with_guard,
+                libc::PROT_NONE,
+                libc::MAP_PRIVATE | libc::MAP_ANON,
+                -1, // Some implementations assert fd = -1 if MAP_ANON is specified
+                0,
+            );
+            assert_ne!(
+                new_stack,
+                libc::MAP_FAILED,
+                "mmap failed to allocate stack: {}",
+                std::io::Error::last_os_error()
+            );
+            let guard = StackRestoreGuard {
+                mapping: new_stack as *mut u8,
+                page_size,
+                size_with_guard,
+                old_stack_limit: get_stack_limit(),
+            };
+            // We leave two guard pages without read/write access in our allocation.
+            // There is one guard page below the stack and another above it.
+            let above_guard_page = new_stack.add(page_size);
+            #[cfg(not(target_os = "openbsd"))]
+            let result = libc::mprotect(
+                above_guard_page,
+                size_with_guard - 2 * page_size,
+                libc::PROT_READ | libc::PROT_WRITE,
+            );
+            #[cfg(target_os = "openbsd")]
+            let result = if libc::mmap(
+                above_guard_page,
+                size_with_guard - 2 * page_size,
+                libc::PROT_READ | libc::PROT_WRITE,
+                libc::MAP_FIXED | libc::MAP_PRIVATE | libc::MAP_ANON | libc::MAP_STACK,
+                -1,
+                0,
+            ) == above_guard_page
+            {
+                0
+            } else {
+                -1
+            };
+            assert_ne!(
+                result,
+                -1,
+                "mprotect/mmap failed: {}",
+                std::io::Error::last_os_error()
+            );
+            guard
+        }
+    }
+
+    // TODO this should return a *mut [u8], but pointer slices only got proper support with Rust 1.79.
+    pub fn stack_area(&self) -> (*mut u8, usize) {
+        unsafe {
+            (
+                self.mapping.add(self.page_size),
+                self.size_with_guard - self.page_size,
+            )
+        }
+    }
+}
+
+impl Drop for StackRestoreGuard {
+    fn drop(&mut self) {
+        unsafe {
+            // FIXME: check the error code and decide what to do with it.
+            // Perhaps a debug_assertion?
+            libc::munmap(self.mapping as *mut std::ffi::c_void, self.size_with_guard);
+        }
+        set_stack_limit(self.old_stack_limit);
+    }
+}
+
+fn page_size() -> usize {
+    // FIXME: consider caching the page size.
+    unsafe { libc::sysconf(libc::_SC_PAGE_SIZE) as usize }
+}