Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 1240 insertions, 0 deletions

diff --git a/third_party/rust/libloading/src/os/mod.rs b/third_party/rust/libloading/src/os/mod.rs
new file mode 100644
index 0000000000..710353f5ef
--- /dev/null
+++ b/third_party/rust/libloading/src/os/mod.rs
@@ -0,0 +1,27 @@
+//! Unsafe but flexible platform-specific bindings to dynamic library loading facilities.
+//!
+//! These modules expose more extensive and powerful bindings to the dynamic
+//! library loading facilities. Use of these bindings come at the cost of less (in most cases,
+//! none at all) safety guarantees, which are provided by the top-level bindings.
+//!
+//! # Examples
+//!
+//! Using these modules will likely involve conditional compilation:
+//!
+//! ```ignore
+//! # extern crate libloading;
+//! #[cfg(unix)]
+//! use libloading::os::unix::*;
+//! #[cfg(windows)]
+//! use libloading::os::windows::*;
+//! ```
+
+/// UNIX implementation of dynamic library loading.
+#[cfg(any(unix, libloading_docs))]
+#[cfg_attr(libloading_docs, doc(cfg(unix)))]
+pub mod unix;
+
+/// Windows implementation of dynamic library loading.
+#[cfg(any(windows, libloading_docs))]
+#[cfg_attr(libloading_docs, doc(cfg(windows)))]
+pub mod windows;
diff --git a/third_party/rust/libloading/src/os/unix/consts.rs b/third_party/rust/libloading/src/os/unix/consts.rs
new file mode 100644
index 0000000000..ea7a6a102d
--- /dev/null
+++ b/third_party/rust/libloading/src/os/unix/consts.rs
@@ -0,0 +1,237 @@
+use std::os::raw::c_int;
+
+/// Perform lazy binding.
+///
+/// Relocations shall be performed at an implementation-defined time, ranging from the time
+/// of the [`Library::open`] call until the first reference to a given symbol occurs.
+/// Specifying `RTLD_LAZY` should improve performance on implementations supporting dynamic
+/// symbol binding since a process might not reference all of the symbols in an executable
+/// object file. And, for systems supporting dynamic symbol resolution for normal process
+/// execution, this behaviour mimics the normal handling of process execution.
+///
+/// Conflicts with [`RTLD_NOW`].
+///
+/// [`Library::open`]: crate::os::unix::Library::open
+pub const RTLD_LAZY: c_int = posix::RTLD_LAZY;
+
+/// Perform eager binding.
+///
+/// All necessary relocations shall be performed when the executable object file is first
+/// loaded. This may waste some processing if relocations are performed for symbols
+/// that are never referenced. This behaviour may be useful for applications that need to
+/// know that all symbols referenced during execution will be available before
+/// [`Library::open`] returns.
+///
+/// Conflicts with [`RTLD_LAZY`].
+///
+/// [`Library::open`]: crate::os::unix::Library::open
+pub const RTLD_NOW: c_int = posix::RTLD_NOW;
+
+/// Make loaded symbols available for resolution globally.
+///
+/// The executable object file's symbols shall be made available for relocation processing of any
+/// other executable object file. In addition, calls to [`Library::get`] on `Library` obtained from
+/// [`Library::this`] allows executable object files loaded with this mode to be searched.
+///
+/// [`Library::this`]: crate::os::unix::Library::this
+/// [`Library::get`]: crate::os::unix::Library::get
+pub const RTLD_GLOBAL: c_int = posix::RTLD_GLOBAL;
+
+/// Load symbols into an isolated namespace.
+///
+/// The executable object file's symbols shall not be made available for relocation processing of
+/// any other executable object file. This mode of operation is most appropriate for e.g. plugins.
+pub const RTLD_LOCAL: c_int = posix::RTLD_LOCAL;
+
+#[cfg(all(libloading_docs, not(unix)))]
+mod posix {
+    use super::c_int;
+    pub(super) const RTLD_LAZY: c_int = !0;
+    pub(super) const RTLD_NOW: c_int = !0;
+    pub(super) const RTLD_GLOBAL: c_int = !0;
+    pub(super) const RTLD_LOCAL: c_int = !0;
+}
+
+#[cfg(any(not(libloading_docs), unix))]
+mod posix {
+    extern crate cfg_if;
+    use self::cfg_if::cfg_if;
+    use super::c_int;
+    cfg_if! {
+        if #[cfg(target_os = "haiku")] {
+            pub(super) const RTLD_LAZY: c_int = 0;
+        } else if #[cfg(target_os = "aix")] {
+            pub(super) const RTLD_LAZY: c_int = 4;
+        } else if #[cfg(any(
+            target_os = "linux",
+            target_os = "android",
+            target_os = "emscripten",
+
+            target_os = "macos",
+            target_os = "ios",
+            target_os = "freebsd",
+            target_os = "dragonfly",
+            target_os = "openbsd",
+            target_os = "netbsd",
+
+            target_os = "solaris",
+            target_os = "illumos",
+
+            target_env = "uclibc",
+            target_env = "newlib",
+
+            target_os = "fuchsia",
+            target_os = "redox",
+        ))] {
+            pub(super) const RTLD_LAZY: c_int = 1;
+        } else {
+            compile_error!(
+                "Target has no known `RTLD_LAZY` value. Please submit an issue or PR adding it."
+            );
+        }
+    }
+
+    cfg_if! {
+        if #[cfg(target_os = "haiku")] {
+            pub(super) const RTLD_NOW: c_int = 1;
+        } else if #[cfg(any(
+            target_os = "linux",
+            all(target_os = "android", target_pointer_width = "64"),
+            target_os = "emscripten",
+
+            target_os = "macos",
+            target_os = "ios",
+            target_os = "freebsd",
+            target_os = "dragonfly",
+            target_os = "openbsd",
+            target_os = "netbsd",
+
+            target_os = "aix",
+            target_os = "solaris",
+            target_os = "illumos",
+
+            target_env = "uclibc",
+            target_env = "newlib",
+
+            target_os = "fuchsia",
+            target_os = "redox",
+        ))] {
+            pub(super) const RTLD_NOW: c_int = 2;
+        } else if #[cfg(all(target_os = "android",target_pointer_width = "32"))] {
+            pub(super) const RTLD_NOW: c_int = 0;
+        } else {
+            compile_error!(
+                "Target has no known `RTLD_NOW` value. Please submit an issue or PR adding it."
+            );
+        }
+    }
+
+    cfg_if! {
+        if #[cfg(any(
+            target_os = "haiku",
+            all(target_os = "android",target_pointer_width = "32"),
+        ))] {
+            pub(super) const RTLD_GLOBAL: c_int = 2;
+        } else if #[cfg(target_os = "aix")] {
+            pub(super) const RTLD_GLOBAL: c_int = 0x10000;
+        } else if #[cfg(any(
+            target_env = "uclibc",
+            all(target_os = "linux", target_arch = "mips"),
+            all(target_os = "linux", target_arch = "mips64"),
+        ))] {
+            pub(super) const RTLD_GLOBAL: c_int = 4;
+        } else if #[cfg(any(
+            target_os = "macos",
+            target_os = "ios",
+        ))] {
+            pub(super) const RTLD_GLOBAL: c_int = 8;
+        } else if #[cfg(any(
+            target_os = "linux",
+            all(target_os = "android", target_pointer_width = "64"),
+            target_os = "emscripten",
+
+            target_os = "freebsd",
+            target_os = "dragonfly",
+            target_os = "openbsd",
+            target_os = "netbsd",
+
+            target_os = "solaris",
+            target_os = "illumos",
+
+            target_env = "newlib",
+
+            target_os = "fuchsia",
+            target_os = "redox",
+        ))] {
+            pub(super) const RTLD_GLOBAL: c_int = 0x100;
+        } else {
+            compile_error!(
+                "Target has no known `RTLD_GLOBAL` value. Please submit an issue or PR adding it."
+            );
+        }
+    }
+
+    cfg_if! {
+        if #[cfg(target_os = "netbsd")] {
+            pub(super) const RTLD_LOCAL: c_int = 0x200;
+        } else if #[cfg(target_os = "aix")] {
+            pub(super) const RTLD_LOCAL: c_int = 0x80000;
+        } else if #[cfg(any(
+            target_os = "macos",
+            target_os = "ios",
+        ))] {
+            pub(super) const RTLD_LOCAL: c_int = 4;
+        } else if #[cfg(any(
+            target_os = "linux",
+            target_os = "android",
+            target_os = "emscripten",
+
+            target_os = "freebsd",
+            target_os = "dragonfly",
+            target_os = "openbsd",
+
+            target_os = "haiku",
+
+            target_os = "solaris",
+            target_os = "illumos",
+
+            target_env = "uclibc",
+            target_env = "newlib",
+
+            target_os = "fuchsia",
+            target_os = "redox",
+        ))] {
+            pub(super) const RTLD_LOCAL: c_int = 0;
+        } else {
+            compile_error!(
+                "Target has no known `RTLD_LOCAL` value. Please submit an issue or PR adding it."
+            );
+        }
+    }
+}
+
+// Other constants that exist but are not bound because they are platform-specific (non-posix)
+// extensions. Some of these constants are only relevant to `dlsym` or `dlmopen` calls.
+//
+// RTLD_CONFGEN
+// RTLD_DEFAULT
+// RTLD_DI_CONFIGADDR
+// RTLD_DI_LINKMAP
+// RTLD_DI_LMID
+// RTLD_DI_ORIGIN
+// RTLD_DI_PROFILENAME
+// RTLD_DI_PROFILEOUT
+// RTLD_DI_SERINFO
+// RTLD_DI_SERINFOSIZE
+// RTLD_DI_TLS_DATA
+// RTLD_DI_TLS_MODID
+// RTLD_FIRST
+// RTLD_GROUP
+// RTLD_NEXT
+// RTLD_PARENT
+// RTLD_PROBE
+// RTLD_SELF
+// RTLD_WORLD
+// RTLD_NODELETE
+// RTLD_NOLOAD
+// RTLD_DEEPBIND
diff --git a/third_party/rust/libloading/src/os/unix/mod.rs b/third_party/rust/libloading/src/os/unix/mod.rs
new file mode 100644
index 0000000000..df7efdad54
--- /dev/null
+++ b/third_party/rust/libloading/src/os/unix/mod.rs
@@ -0,0 +1,444 @@
+// A hack for docs.rs to build documentation that has both windows and linux documentation in the
+// same rustdoc build visible.
+#[cfg(all(libloading_docs, not(unix)))]
+mod unix_imports {}
+#[cfg(any(not(libloading_docs), unix))]
+mod unix_imports {
+    pub(super) use std::os::unix::ffi::OsStrExt;
+}
+
+pub use self::consts::*;
+use self::unix_imports::*;
+use std::ffi::{CStr, OsStr};
+use std::os::raw;
+use std::{fmt, marker, mem, ptr};
+use util::{cstr_cow_from_bytes, ensure_compatible_types};
+
+mod consts;
+
+// dl* family of functions did not have enough thought put into it.
+//
+// Whole error handling scheme is done via setting and querying some global state, therefore it is
+// not safe to use dynamic library loading in MT-capable environment at all. Only in POSIX 2008+TC1
+// a thread-local state was allowed for `dlerror`, making the dl* family of functions MT-safe.
+//
+// In practice (as of 2020-04-01) most of the widely used targets use a thread-local for error
+// state and have been doing so for a long time. Regardless the comments in this function shall
+// remain as a documentation for the future generations.
+fn with_dlerror<T, F>(wrap: fn(crate::error::DlDescription) -> crate::Error, closure: F)
+-> Result<T, Option<crate::Error>>
+where F: FnOnce() -> Option<T> {
+    // We used to guard all uses of dl* functions with our own mutex. This made them safe to use in
+    // MT programs provided the only way a program used dl* was via this library. However, it also
+    // had a number of downsides or cases where it failed to handle the problems. For instance,
+    // if any other library called `dlerror` internally concurrently with `libloading` things would
+    // still go awry.
+    //
+    // On platforms where `dlerror` is still MT-unsafe, `dlsym` (`Library::get`) can spuriously
+    // succeed and return a null pointer for a symbol when the actual symbol look-up operation
+    // fails. Instances where the actual symbol _could_ be `NULL` are platform specific. For
+    // instance on GNU glibc based-systems (an excerpt from dlsym(3)):
+    //
+    // > The value of a symbol returned by dlsym() will never be NULL if the shared object is the
+    // > result of normal compilation,  since  a  global  symbol is never placed at the NULL
+    // > address. There are nevertheless cases where a lookup using dlsym() may return NULL as the
+    // > value of a symbol. For example, the symbol value may be  the  result of a GNU indirect
+    // > function (IFUNC) resolver function that returns NULL as the resolved value.
+
+    // While we could could call `dlerror` here to clear the previous error value, only the `dlsym`
+    // call depends on it being cleared beforehand and only in some cases too. We will instead
+    // clear the error inside the dlsym binding instead.
+    //
+    // In all the other cases, clearing the error here will only be hiding misuse of these bindings
+    // or a bug in implementation of dl* family of functions.
+    closure().ok_or_else(|| unsafe {
+        // This code will only get executed if the `closure` returns `None`.
+        let error = dlerror();
+        if error.is_null() {
+            // In non-dlsym case this may happen when there’re bugs in our bindings or there’s
+            // non-libloading user of libdl; possibly in another thread.
+            None
+        } else {
+            // You can’t even rely on error string being static here; call to subsequent dlerror
+            // may invalidate or overwrite the error message. Why couldn’t they simply give up the
+            // ownership over the message?
+            // TODO: should do locale-aware conversion here. OTOH Rust doesn’t seem to work well in
+            // any system that uses non-utf8 locale, so I doubt there’s a problem here.
+            let message = CStr::from_ptr(error).into();
+            Some(wrap(crate::error::DlDescription(message)))
+            // Since we do a copy of the error string above, maybe we should call dlerror again to
+            // let libdl know it may free its copy of the string now?
+        }
+    })
+}
+
+/// A platform-specific counterpart of the cross-platform [`Library`](crate::Library).
+pub struct Library {
+    handle: *mut raw::c_void
+}
+
+unsafe impl Send for Library {}
+
+// That being said... this section in the volume 2 of POSIX.1-2008 states:
+//
+// > All functions defined by this volume of POSIX.1-2008 shall be thread-safe, except that the
+// > following functions need not be thread-safe.
+//
+// With notable absence of any dl* function other than dlerror in the list. By “this volume”
+// I suppose they refer precisely to the “volume 2”. dl* family of functions are specified
+// by this same volume, so the conclusion is indeed that dl* functions are required by POSIX
+// to be thread-safe. Great!
+//
+// See for more details:
+//
+//  * https://github.com/nagisa/rust_libloading/pull/17
+//  * http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_09_01
+unsafe impl Sync for Library {}
+
+impl Library {
+    /// Find and eagerly load a shared library (module).
+    ///
+    /// If the `filename` contains a [path separator], the `filename` is interpreted as a `path` to
+    /// a file. Otherwise, platform-specific algorithms are employed to find a library with a
+    /// matching file name.
+    ///
+    /// This is equivalent to <code>[Library::open](filename, [RTLD_LAZY] | [RTLD_LOCAL])</code>.
+    ///
+    /// [path separator]: std::path::MAIN_SEPARATOR
+    ///
+    /// # Safety
+    ///
+    /// When a library is loaded, initialisation routines contained within the library are executed.
+    /// For the purposes of safety, the execution of these routines is conceptually the same calling an
+    /// unknown foreign function and may impose arbitrary requirements on the caller for the call
+    /// to be sound.
+    ///
+    /// Additionally, the callers of this function must also ensure that execution of the
+    /// termination routines contained within the library is safe as well. These routines may be
+    /// executed when the library is unloaded.
+    #[inline]
+    pub unsafe fn new<P: AsRef<OsStr>>(filename: P) -> Result<Library, crate::Error> {
+        Library::open(Some(filename), RTLD_LAZY | RTLD_LOCAL)
+    }
+
+    /// Load the `Library` representing the current executable.
+    ///
+    /// [`Library::get`] calls of the returned `Library` will look for symbols in following
+    /// locations in order:
+    ///
+    /// 1. The original program image;
+    /// 2. Any executable object files (e.g. shared libraries) loaded at program startup;
+    /// 3. Any executable object files loaded at runtime (e.g. via other `Library::new` calls or via
+    ///    calls to the `dlopen` function).
+    ///
+    /// Note that the behaviour of a `Library` loaded with this method is different from that of
+    /// Libraries loaded with [`os::windows::Library::this`].
+    ///
+    /// This is equivalent to <code>[Library::open](None, [RTLD_LAZY] | [RTLD_LOCAL])</code>.
+    ///
+    /// [`os::windows::Library::this`]: crate::os::windows::Library::this
+    #[inline]
+    pub fn this() -> Library {
+        unsafe {
+            // SAFE: this does not load any new shared library images, no danger in it executing
+            // initialiser routines.
+            Library::open(None::<&OsStr>, RTLD_LAZY | RTLD_LOCAL).expect("this should never fail")
+        }
+    }
+
+    /// Find and load an executable object file (shared library).
+    ///
+    /// See documentation for [`Library::this`] for further description of the behaviour
+    /// when the `filename` is `None`. Otherwise see [`Library::new`].
+    ///
+    /// Corresponds to `dlopen(filename, flags)`.
+    ///
+    /// # Safety
+    ///
+    /// When a library is loaded, initialisation routines contained within the library are executed.
+    /// For the purposes of safety, the execution of these routines is conceptually the same calling an
+    /// unknown foreign function and may impose arbitrary requirements on the caller for the call
+    /// to be sound.
+    ///
+    /// Additionally, the callers of this function must also ensure that execution of the
+    /// termination routines contained within the library is safe as well. These routines may be
+    /// executed when the library is unloaded.
+    pub unsafe fn open<P>(filename: Option<P>, flags: raw::c_int) -> Result<Library, crate::Error>
+    where P: AsRef<OsStr> {
+        let filename = match filename {
+            None => None,
+            Some(ref f) => Some(cstr_cow_from_bytes(f.as_ref().as_bytes())?),
+        };
+        with_dlerror(|desc| crate::Error::DlOpen { desc }, move || {
+            let result = dlopen(match filename {
+                None => ptr::null(),
+                Some(ref f) => f.as_ptr()
+            }, flags);
+            // ensure filename lives until dlopen completes
+            drop(filename);
+            if result.is_null() {
+                None
+            } else {
+                Some(Library {
+                    handle: result
+                })
+            }
+        }).map_err(|e| e.unwrap_or(crate::Error::DlOpenUnknown))
+    }
+
+    unsafe fn get_impl<T, F>(&self, symbol: &[u8], on_null: F) -> Result<Symbol<T>, crate::Error>
+    where F: FnOnce() -> Result<Symbol<T>, crate::Error>
+    {
+        ensure_compatible_types::<T, *mut raw::c_void>()?;
+        let symbol = cstr_cow_from_bytes(symbol)?;
+        // `dlsym` may return nullptr in two cases: when a symbol genuinely points to a null
+        // pointer or the symbol cannot be found. In order to detect this case a double dlerror
+        // pattern must be used, which is, sadly, a little bit racy.
+        //
+        // We try to leave as little space as possible for this to occur, but we can’t exactly
+        // fully prevent it.
+        match with_dlerror(|desc| crate::Error::DlSym { desc }, || {
+            dlerror();
+            let symbol = dlsym(self.handle, symbol.as_ptr());
+            if symbol.is_null() {
+                None
+            } else {
+                Some(Symbol {
+                    pointer: symbol,
+                    pd: marker::PhantomData
+                })
+            }
+        }) {
+            Err(None) => on_null(),
+            Err(Some(e)) => Err(e),
+            Ok(x) => Ok(x)
+        }
+
+    }
+
+    /// Get a pointer to a function or static variable by symbol name.
+    ///
+    /// The `symbol` may not contain any null bytes, with the exception of the last byte. Providing a
+    /// null terminated `symbol` may help to avoid an allocation.
+    ///
+    /// Symbol is interpreted as-is; no mangling is done. This means that symbols like `x::y` are
+    /// most likely invalid.
+    ///
+    /// # Safety
+    ///
+    /// Users of this API must specify the correct type of the function or variable loaded. Using a
+    /// `Symbol` with a wrong type is undefined.
+    ///
+    /// # Platform-specific behaviour
+    ///
+    /// Implementation of thread local variables is extremely platform specific and uses of such
+    /// variables that work on e.g. Linux may have unintended behaviour on other targets.
+    ///
+    /// On POSIX implementations where the `dlerror` function is not confirmed to be MT-safe (such
+    /// as FreeBSD), this function will unconditionally return an error when the underlying `dlsym`
+    /// call returns a null pointer. There are rare situations where `dlsym` returns a genuine null
+    /// pointer without it being an error. If loading a null pointer is something you care about,
+    /// consider using the [`Library::get_singlethreaded`] call.
+    #[inline(always)]
+    pub unsafe fn get<T>(&self, symbol: &[u8]) -> Result<Symbol<T>, crate::Error> {
+        extern crate cfg_if;
+        cfg_if::cfg_if! {
+            // These targets are known to have MT-safe `dlerror`.
+            if #[cfg(any(
+                target_os = "linux",
+                target_os = "android",
+                target_os = "openbsd",
+                target_os = "macos",
+                target_os = "ios",
+                target_os = "solaris",
+                target_os = "illumos",
+                target_os = "redox",
+                target_os = "fuchsia"
+            ))] {
+                self.get_singlethreaded(symbol)
+            } else {
+                self.get_impl(symbol, || Err(crate::Error::DlSymUnknown))
+            }
+        }
+    }
+
+    /// Get a pointer to function or static variable by symbol name.
+    ///
+    /// The `symbol` may not contain any null bytes, with the exception of the last byte. Providing a
+    /// null terminated `symbol` may help to avoid an allocation.
+    ///
+    /// Symbol is interpreted as-is; no mangling is done. This means that symbols like `x::y` are
+    /// most likely invalid.
+    ///
+    /// # Safety
+    ///
+    /// Users of this API must specify the correct type of the function or variable loaded.
+    ///
+    /// It is up to the user of this library to ensure that no other calls to an MT-unsafe
+    /// implementation of `dlerror` occur during the execution of this function. Failing that, the
+    /// behaviour of this function is not defined.
+    ///
+    /// # Platform-specific behaviour
+    ///
+    /// The implementation of thread-local variables is extremely platform specific and uses of such
+    /// variables that work on e.g. Linux may have unintended behaviour on other targets.
+    #[inline(always)]
+    pub unsafe fn get_singlethreaded<T>(&self, symbol: &[u8]) -> Result<Symbol<T>, crate::Error> {
+        self.get_impl(symbol, || Ok(Symbol {
+            pointer: ptr::null_mut(),
+            pd: marker::PhantomData
+        }))
+    }
+
+    /// Convert the `Library` to a raw handle.
+    ///
+    /// The handle returned by this function shall be usable with APIs which accept handles
+    /// as returned by `dlopen`.
+    pub fn into_raw(self) -> *mut raw::c_void {
+        let handle = self.handle;
+        mem::forget(self);
+        handle
+    }
+
+    /// Convert a raw handle returned by `dlopen`-family of calls to a `Library`.
+    ///
+    /// # Safety
+    ///
+    /// The pointer shall be a result of a successful call of the `dlopen`-family of functions or a
+    /// pointer previously returned by `Library::into_raw` call. It must be valid to call `dlclose`
+    /// with this pointer as an argument.
+    pub unsafe fn from_raw(handle: *mut raw::c_void) -> Library {
+        Library {
+            handle
+        }
+    }
+
+    /// Unload the library.
+    ///
+    /// This method might be a no-op, depending on the flags with which the `Library` was opened,
+    /// what library was opened or other platform specifics.
+    ///
+    /// You only need to call this if you are interested in handling any errors that may arise when
+    /// library is unloaded. Otherwise the implementation of `Drop` for `Library` will close the
+    /// library and ignore the errors were they arise.
+    ///
+    /// The underlying data structures may still get leaked if an error does occur.
+    pub fn close(self) -> Result<(), crate::Error> {
+        let result = with_dlerror(|desc| crate::Error::DlClose { desc }, || {
+            if unsafe { dlclose(self.handle) } == 0 {
+                Some(())
+            } else {
+                None
+            }
+        }).map_err(|e| e.unwrap_or(crate::Error::DlCloseUnknown));
+        // While the library is not free'd yet in case of an error, there is no reason to try
+        // dropping it again, because all that will do is try calling `dlclose` again. only
+        // this time it would ignore the return result, which we already seen failing…
+        std::mem::forget(self);
+        result
+    }
+}
+
+impl Drop for Library {
+    fn drop(&mut self) {
+        unsafe {
+            dlclose(self.handle);
+        }
+    }
+}
+
+impl fmt::Debug for Library {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&format!("Library@{:p}", self.handle))
+    }
+}
+
+/// Symbol from a library.
+///
+/// A major difference compared to the cross-platform `Symbol` is that this does not ensure that the
+/// `Symbol` does not outlive the `Library` it comes from.
+pub struct Symbol<T> {
+    pointer: *mut raw::c_void,
+    pd: marker::PhantomData<T>
+}
+
+impl<T> Symbol<T> {
+    /// Convert the loaded `Symbol` into a raw pointer.
+    pub fn into_raw(self) -> *mut raw::c_void {
+        self.pointer
+    }
+}
+
+impl<T> Symbol<Option<T>> {
+    /// Lift Option out of the symbol.
+    pub fn lift_option(self) -> Option<Symbol<T>> {
+        if self.pointer.is_null() {
+            None
+        } else {
+            Some(Symbol {
+                pointer: self.pointer,
+                pd: marker::PhantomData,
+            })
+        }
+    }
+}
+
+unsafe impl<T: Send> Send for Symbol<T> {}
+unsafe impl<T: Sync> Sync for Symbol<T> {}
+
+impl<T> Clone for Symbol<T> {
+    fn clone(&self) -> Symbol<T> {
+        Symbol { ..*self }
+    }
+}
+
+impl<T> ::std::ops::Deref for Symbol<T> {
+    type Target = T;
+    fn deref(&self) -> &T {
+        unsafe {
+            // Additional reference level for a dereference on `deref` return value.
+            &*(&self.pointer as *const *mut _ as *const T)
+        }
+    }
+}
+
+impl<T> fmt::Debug for Symbol<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        unsafe {
+            let mut info = mem::MaybeUninit::<DlInfo>::uninit();
+            if dladdr(self.pointer, info.as_mut_ptr()) != 0 {
+                let info = info.assume_init();
+                if info.dli_sname.is_null() {
+                    f.write_str(&format!("Symbol@{:p} from {:?}",
+                                         self.pointer,
+                                         CStr::from_ptr(info.dli_fname)))
+                } else {
+                    f.write_str(&format!("Symbol {:?}@{:p} from {:?}",
+                                         CStr::from_ptr(info.dli_sname), self.pointer,
+                                         CStr::from_ptr(info.dli_fname)))
+                }
+            } else {
+                f.write_str(&format!("Symbol@{:p}", self.pointer))
+            }
+        }
+    }
+}
+
+// Platform specific things
+#[cfg_attr(any(target_os = "linux", target_os = "android"), link(name="dl"))]
+#[cfg_attr(any(target_os = "freebsd", target_os = "dragonfly"), link(name="c"))]
+extern {
+    fn dlopen(filename: *const raw::c_char, flags: raw::c_int) -> *mut raw::c_void;
+    fn dlclose(handle: *mut raw::c_void) -> raw::c_int;
+    fn dlsym(handle: *mut raw::c_void, symbol: *const raw::c_char) -> *mut raw::c_void;
+    fn dlerror() -> *mut raw::c_char;
+    fn dladdr(addr: *mut raw::c_void, info: *mut DlInfo) -> raw::c_int;
+}
+
+#[repr(C)]
+struct DlInfo {
+  dli_fname: *const raw::c_char,
+  dli_fbase: *mut raw::c_void,
+  dli_sname: *const raw::c_char,
+  dli_saddr: *mut raw::c_void
+}
diff --git a/third_party/rust/libloading/src/os/windows/mod.rs b/third_party/rust/libloading/src/os/windows/mod.rs
new file mode 100644
index 0000000000..e3da940a29
--- /dev/null
+++ b/third_party/rust/libloading/src/os/windows/mod.rs
@@ -0,0 +1,532 @@
+// A hack for docs.rs to build documentation that has both windows and linux documentation in the
+// same rustdoc build visible.
+#[cfg(all(libloading_docs, not(windows)))]
+mod windows_imports {
+    pub(super) enum WORD {}
+    pub(super) struct DWORD;
+    pub(super) enum HMODULE {}
+    pub(super) enum FARPROC {}
+
+    pub(super) mod consts {
+        use super::DWORD;
+        pub(crate) const LOAD_IGNORE_CODE_AUTHZ_LEVEL: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_AS_DATAFILE: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_AS_IMAGE_RESOURCE: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_SEARCH_APPLICATION_DIR: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_SEARCH_DEFAULT_DIRS: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_SEARCH_SYSTEM32: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_SEARCH_USER_DIRS: DWORD = DWORD;
+        pub(crate) const LOAD_WITH_ALTERED_SEARCH_PATH: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_REQUIRE_SIGNED_TARGET: DWORD = DWORD;
+        pub(crate) const LOAD_LIBRARY_SAFE_CURRENT_DIRS: DWORD = DWORD;
+    }
+}
+#[cfg(any(not(libloading_docs), windows))]
+mod windows_imports {
+    extern crate winapi;
+    pub(super) use self::winapi::shared::minwindef::{WORD, DWORD, HMODULE, FARPROC};
+    pub(super) use self::winapi::shared::ntdef::WCHAR;
+    pub(super) use self::winapi::um::{errhandlingapi, libloaderapi};
+    pub(super) use std::os::windows::ffi::{OsStrExt, OsStringExt};
+    pub(super) const SEM_FAILCE: DWORD = 1;
+
+    pub(super) mod consts {
+        pub(crate) use super::winapi::um::libloaderapi::{
+            LOAD_IGNORE_CODE_AUTHZ_LEVEL,
+            LOAD_LIBRARY_AS_DATAFILE,
+            LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE,
+            LOAD_LIBRARY_AS_IMAGE_RESOURCE,
+            LOAD_LIBRARY_SEARCH_APPLICATION_DIR,
+            LOAD_LIBRARY_SEARCH_DEFAULT_DIRS,
+            LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR,
+            LOAD_LIBRARY_SEARCH_SYSTEM32,
+            LOAD_LIBRARY_SEARCH_USER_DIRS,
+            LOAD_WITH_ALTERED_SEARCH_PATH,
+            LOAD_LIBRARY_REQUIRE_SIGNED_TARGET,
+            LOAD_LIBRARY_SAFE_CURRENT_DIRS,
+        };
+    }
+}
+
+use self::windows_imports::*;
+use util::{ensure_compatible_types, cstr_cow_from_bytes};
+use std::ffi::{OsStr, OsString};
+use std::{fmt, io, marker, mem, ptr};
+
+/// The platform-specific counterpart of the cross-platform [`Library`](crate::Library).
+pub struct Library(HMODULE);
+
+unsafe impl Send for Library {}
+// Now, this is sort-of-tricky. MSDN documentation does not really make any claims as to safety of
+// the Win32 APIs. Sadly, whomever I asked, even current and former Microsoft employees, couldn’t
+// say for sure whether the Win32 APIs used to implement `Library` are thread-safe or not.
+//
+// My investigation ended up with a question about thread-safety properties of the API involved
+// being sent to an internal (to MS) general question mailing-list. The conclusion of the mail is
+// as such:
+//
+// * Nobody inside MS (at least out of all of the people who have seen the question) knows for
+//   sure either;
+// * However, the general consensus between MS developers is that one can rely on the API being
+//   thread-safe. In case it is not thread-safe it should be considered a bug on the Windows
+//   part. (NB: bugs filed at https://connect.microsoft.com/ against Windows Server)
+unsafe impl Sync for Library {}
+
+impl Library {
+    /// Find and load a module.
+    ///
+    /// If the `filename` specifies a full path, the function only searches that path for the
+    /// module. Otherwise, if the `filename` specifies a relative path or a module name without a
+    /// path, the function uses a Windows-specific search strategy to find the module. For more
+    /// information, see the [Remarks on MSDN][msdn].
+    ///
+    /// If the `filename` specifies a library filename without a path and with the extension omitted,
+    /// the `.dll` extension is implicitly added. This behaviour may be suppressed by appending a
+    /// trailing `.` to the `filename`.
+    ///
+    /// This is equivalent to <code>[Library::load_with_flags](filename, 0)</code>.
+    ///
+    /// [msdn]: https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryw#remarks
+    ///
+    /// # Safety
+    ///
+    /// When a library is loaded, initialisation routines contained within the library are executed.
+    /// For the purposes of safety, the execution of these routines is conceptually the same calling an
+    /// unknown foreign function and may impose arbitrary requirements on the caller for the call
+    /// to be sound.
+    ///
+    /// Additionally, the callers of this function must also ensure that execution of the
+    /// termination routines contained within the library is safe as well. These routines may be
+    /// executed when the library is unloaded.
+    #[inline]
+    pub unsafe fn new<P: AsRef<OsStr>>(filename: P) -> Result<Library, crate::Error> {
+        Library::load_with_flags(filename, 0)
+    }
+
+    /// Get the `Library` representing the original program executable.
+    ///
+    /// Note that the behaviour of the `Library` loaded with this method is different from
+    /// Libraries loaded with [`os::unix::Library::this`]. For more information refer to [MSDN].
+    ///
+    /// Corresponds to `GetModuleHandleExW(0, NULL, _)`.
+    ///
+    /// [`os::unix::Library::this`]: crate::os::unix::Library::this
+    /// [MSDN]: https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-getmodulehandleexw
+    pub fn this() -> Result<Library, crate::Error> {
+        unsafe {
+            let mut handle: HMODULE = std::ptr::null_mut();
+            with_get_last_error(|source| crate::Error::GetModuleHandleExW { source }, || {
+                let result = libloaderapi::GetModuleHandleExW(0, std::ptr::null_mut(), &mut handle);
+                if result == 0 {
+                    None
+                } else {
+                    Some(Library(handle))
+                }
+            }).map_err(|e| e.unwrap_or(crate::Error::GetModuleHandleExWUnknown))
+        }
+    }
+
+    /// Get a module that is already loaded by the program.
+    ///
+    /// This function returns a `Library` corresponding to a module with the given name that is
+    /// already mapped into the address space of the process. If the module isn't found, an error is
+    /// returned.
+    ///
+    /// If the `filename` does not include a full path and there are multiple different loaded
+    /// modules corresponding to the `filename`, it is impossible to predict which module handle
+    /// will be returned. For more information refer to [MSDN].
+    ///
+    /// If the `filename` specifies a library filename without a path and with the extension omitted,
+    /// the `.dll` extension is implicitly added. This behaviour may be suppressed by appending a
+    /// trailing `.` to the `filename`.
+    ///
+    /// This is equivalent to `GetModuleHandleExW(0, filename, _)`.
+    ///
+    /// [MSDN]: https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-getmodulehandleexw
+    pub fn open_already_loaded<P: AsRef<OsStr>>(filename: P) -> Result<Library, crate::Error> {
+        let wide_filename: Vec<u16> = filename.as_ref().encode_wide().chain(Some(0)).collect();
+
+        let ret = unsafe {
+            let mut handle: HMODULE = std::ptr::null_mut();
+            with_get_last_error(|source| crate::Error::GetModuleHandleExW { source }, || {
+                // Make sure no winapi calls as a result of drop happen inside this closure, because
+                // otherwise that might change the return value of the GetLastError.
+                let result = libloaderapi::GetModuleHandleExW(0, wide_filename.as_ptr(), &mut handle);
+                if result == 0 {
+                    None
+                } else {
+                    Some(Library(handle))
+                }
+            }).map_err(|e| e.unwrap_or(crate::Error::GetModuleHandleExWUnknown))
+        };
+
+        drop(wide_filename); // Drop wide_filename here to ensure it doesn’t get moved and dropped
+                             // inside the closure by mistake. See comment inside the closure.
+        ret
+    }
+
+    /// Find and load a module, additionally adjusting behaviour with flags.
+    ///
+    /// See [`Library::new`] for documentation on the handling of the `filename` argument. See the
+    /// [flag table on MSDN][flags] for information on applicable values for the `flags` argument.
+    ///
+    /// Corresponds to `LoadLibraryExW(filename, reserved: NULL, flags)`.
+    ///
+    /// [flags]: https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters
+    ///
+    /// # Safety
+    ///
+    /// When a library is loaded, initialisation routines contained within the library are executed.
+    /// For the purposes of safety, the execution of these routines is conceptually the same calling an
+    /// unknown foreign function and may impose arbitrary requirements on the caller for the call
+    /// to be sound.
+    ///
+    /// Additionally, the callers of this function must also ensure that execution of the
+    /// termination routines contained within the library is safe as well. These routines may be
+    /// executed when the library is unloaded.
+    pub unsafe fn load_with_flags<P: AsRef<OsStr>>(filename: P, flags: DWORD) -> Result<Library, crate::Error> {
+        let wide_filename: Vec<u16> = filename.as_ref().encode_wide().chain(Some(0)).collect();
+        let _guard = ErrorModeGuard::new();
+
+        let ret = with_get_last_error(|source| crate::Error::LoadLibraryExW { source }, || {
+            // Make sure no winapi calls as a result of drop happen inside this closure, because
+            // otherwise that might change the return value of the GetLastError.
+            let handle =
+                libloaderapi::LoadLibraryExW(wide_filename.as_ptr(), std::ptr::null_mut(), flags);
+            if handle.is_null()  {
+                None
+            } else {
+                Some(Library(handle))
+            }
+        }).map_err(|e| e.unwrap_or(crate::Error::LoadLibraryExWUnknown));
+        drop(wide_filename); // Drop wide_filename here to ensure it doesn’t get moved and dropped
+                             // inside the closure by mistake. See comment inside the closure.
+        ret
+    }
+
+    /// Get a pointer to a function or static variable by symbol name.
+    ///
+    /// The `symbol` may not contain any null bytes, with the exception of the last byte. A null
+    /// terminated `symbol` may avoid a string allocation in some cases.
+    ///
+    /// Symbol is interpreted as-is; no mangling is done. This means that symbols like `x::y` are
+    /// most likely invalid.
+    ///
+    /// # Safety
+    ///
+    /// Users of this API must specify the correct type of the function or variable loaded.
+    pub unsafe fn get<T>(&self, symbol: &[u8]) -> Result<Symbol<T>, crate::Error> {
+        ensure_compatible_types::<T, FARPROC>()?;
+        let symbol = cstr_cow_from_bytes(symbol)?;
+        with_get_last_error(|source| crate::Error::GetProcAddress { source }, || {
+            let symbol = libloaderapi::GetProcAddress(self.0, symbol.as_ptr());
+            if symbol.is_null() {
+                None
+            } else {
+                Some(Symbol {
+                    pointer: symbol,
+                    pd: marker::PhantomData
+                })
+            }
+        }).map_err(|e| e.unwrap_or(crate::Error::GetProcAddressUnknown))
+    }
+
+    /// Get a pointer to a function or static variable by ordinal number.
+    ///
+    /// # Safety
+    ///
+    /// Users of this API must specify the correct type of the function or variable loaded.
+    pub unsafe fn get_ordinal<T>(&self, ordinal: WORD) -> Result<Symbol<T>, crate::Error> {
+        ensure_compatible_types::<T, FARPROC>()?;
+        with_get_last_error(|source| crate::Error::GetProcAddress { source }, || {
+            let ordinal = ordinal as usize as *mut _;
+            let symbol = libloaderapi::GetProcAddress(self.0, ordinal);
+            if symbol.is_null() {
+                None
+            } else {
+                Some(Symbol {
+                    pointer: symbol,
+                    pd: marker::PhantomData
+                })
+            }
+        }).map_err(|e| e.unwrap_or(crate::Error::GetProcAddressUnknown))
+    }
+
+    /// Convert the `Library` to a raw handle.
+    pub fn into_raw(self) -> HMODULE {
+        let handle = self.0;
+        mem::forget(self);
+        handle
+    }
+
+    /// Convert a raw handle to a `Library`.
+    ///
+    /// # Safety
+    ///
+    /// The handle must be the result of a successful call of `LoadLibraryA`, `LoadLibraryW`,
+    /// `LoadLibraryExW`, or `LoadLibraryExA`, or a handle previously returned by the
+    /// `Library::into_raw` call.
+    pub unsafe fn from_raw(handle: HMODULE) -> Library {
+        Library(handle)
+    }
+
+    /// Unload the library.
+    ///
+    /// You only need to call this if you are interested in handling any errors that may arise when
+    /// library is unloaded. Otherwise this will be done when `Library` is dropped.
+    ///
+    /// The underlying data structures may still get leaked if an error does occur.
+    pub fn close(self) -> Result<(), crate::Error> {
+        let result = with_get_last_error(|source| crate::Error::FreeLibrary { source }, || {
+            if unsafe { libloaderapi::FreeLibrary(self.0) == 0 } {
+                None
+            } else {
+                Some(())
+            }
+        }).map_err(|e| e.unwrap_or(crate::Error::FreeLibraryUnknown));
+        // While the library is not free'd yet in case of an error, there is no reason to try
+        // dropping it again, because all that will do is try calling `FreeLibrary` again. only
+        // this time it would ignore the return result, which we already seen failing...
+        std::mem::forget(self);
+        result
+    }
+}
+
+impl Drop for Library {
+    fn drop(&mut self) {
+        unsafe { libloaderapi::FreeLibrary(self.0); }
+    }
+}
+
+impl fmt::Debug for Library {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        unsafe {
+            // FIXME: use Maybeuninit::uninit_array when stable
+            let mut buf =
+                mem::MaybeUninit::<[mem::MaybeUninit::<WCHAR>; 1024]>::uninit().assume_init();
+            let len = libloaderapi::GetModuleFileNameW(self.0,
+                buf[..].as_mut_ptr().cast(), 1024) as usize;
+            if len == 0 {
+                f.write_str(&format!("Library@{:p}", self.0))
+            } else {
+                let string: OsString = OsString::from_wide(
+                    // FIXME: use Maybeuninit::slice_get_ref when stable
+                    &*(&buf[..len] as *const [_] as *const [WCHAR])
+                );
+                f.write_str(&format!("Library@{:p} from {:?}", self.0, string))
+            }
+        }
+    }
+}
+
+/// A symbol from a library.
+///
+/// A major difference compared to the cross-platform `Symbol` is that this does not ensure that the
+/// `Symbol` does not outlive the `Library` that it comes from.
+pub struct Symbol<T> {
+    pointer: FARPROC,
+    pd: marker::PhantomData<T>
+}
+
+impl<T> Symbol<T> {
+    /// Convert the loaded `Symbol` into a handle.
+    pub fn into_raw(self) -> FARPROC {
+        self.pointer
+    }
+}
+
+impl<T> Symbol<Option<T>> {
+    /// Lift Option out of the symbol.
+    pub fn lift_option(self) -> Option<Symbol<T>> {
+        if self.pointer.is_null() {
+            None
+        } else {
+            Some(Symbol {
+                pointer: self.pointer,
+                pd: marker::PhantomData,
+            })
+        }
+    }
+}
+
+unsafe impl<T: Send> Send for Symbol<T> {}
+unsafe impl<T: Sync> Sync for Symbol<T> {}
+
+impl<T> Clone for Symbol<T> {
+    fn clone(&self) -> Symbol<T> {
+        Symbol { ..*self }
+    }
+}
+
+impl<T> ::std::ops::Deref for Symbol<T> {
+    type Target = T;
+    fn deref(&self) -> &T {
+        unsafe {
+            // Additional reference level for a dereference on `deref` return value.
+            &*(&self.pointer as *const *mut _ as *const T)
+        }
+    }
+}
+
+impl<T> fmt::Debug for Symbol<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(&format!("Symbol@{:p}", self.pointer))
+    }
+}
+
+struct ErrorModeGuard(DWORD);
+
+impl ErrorModeGuard {
+    #[allow(clippy::if_same_then_else)]
+    fn new() -> Option<ErrorModeGuard> {
+        unsafe {
+            let mut previous_mode = 0;
+            if errhandlingapi::SetThreadErrorMode(SEM_FAILCE, &mut previous_mode) == 0 {
+                // How in the world is it possible for what is essentially a simple variable swap
+                // to fail?  For now we just ignore the error -- the worst that can happen here is
+                // the previous mode staying on and user seeing a dialog error on older Windows
+                // machines.
+                None
+            } else if previous_mode == SEM_FAILCE {
+                None
+            } else {
+                Some(ErrorModeGuard(previous_mode))
+            }
+        }
+    }
+}
+
+impl Drop for ErrorModeGuard {
+    fn drop(&mut self) {
+        unsafe {
+            errhandlingapi::SetThreadErrorMode(self.0, ptr::null_mut());
+        }
+    }
+}
+
+fn with_get_last_error<T, F>(wrap: fn(crate::error::WindowsError) -> crate::Error, closure: F)
+-> Result<T, Option<crate::Error>>
+where F: FnOnce() -> Option<T> {
+    closure().ok_or_else(|| {
+        let error = unsafe { errhandlingapi::GetLastError() };
+        if error == 0 {
+            None
+        } else {
+            Some(wrap(crate::error::WindowsError(io::Error::from_raw_os_error(error as i32))))
+        }
+    })
+}
+
+/// Do not check AppLocker rules or apply Software Restriction Policies for the DLL.
+///
+/// This action applies only to the DLL being loaded and not to its dependencies. This value is
+/// recommended for use in setup programs that must run extracted DLLs during installation.
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_IGNORE_CODE_AUTHZ_LEVEL: DWORD = consts::LOAD_IGNORE_CODE_AUTHZ_LEVEL;
+
+/// Map the file into the calling process’ virtual address space as if it were a data file.
+///
+/// Nothing is done to execute or prepare to execute the mapped file. Therefore, you cannot call
+/// functions like [`Library::get`] with this DLL. Using this value causes writes to read-only
+/// memory to raise an access violation. Use this flag when you want to load a DLL only to extract
+/// messages or resources from it.
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_AS_DATAFILE: DWORD = consts::LOAD_LIBRARY_AS_DATAFILE;
+
+/// Map the file into the calling process’ virtual address space as if it were a data file.
+///
+/// Similar to [`LOAD_LIBRARY_AS_DATAFILE`], except that the DLL file is opened with exclusive
+/// write access for the calling process. Other processes cannot open the DLL file for write access
+/// while it is in use. However, the DLL can still be opened by other processes.
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE: DWORD = consts::LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE;
+
+/// Map the file into the process’ virtual address space as an image file.
+///
+/// The loader does not load the static imports or perform the other usual initialisation steps.
+/// Use this flag when you want to load a DLL only to extract messages or resources from it.
+///
+/// Unless the application depends on the file having the in-memory layout of an image, this value
+/// should be used with either [`LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE`] or
+/// [`LOAD_LIBRARY_AS_DATAFILE`].
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_AS_IMAGE_RESOURCE: DWORD = consts::LOAD_LIBRARY_AS_IMAGE_RESOURCE;
+
+/// Search the application's installation directory for the DLL and its dependencies.
+///
+/// Directories in the standard search path are not searched. This value cannot be combined with
+/// [`LOAD_WITH_ALTERED_SEARCH_PATH`].
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_SEARCH_APPLICATION_DIR: DWORD = consts::LOAD_LIBRARY_SEARCH_APPLICATION_DIR;
+
+/// Search default directories when looking for the DLL and its dependencies.
+///
+/// This value is a combination of [`LOAD_LIBRARY_SEARCH_APPLICATION_DIR`],
+/// [`LOAD_LIBRARY_SEARCH_SYSTEM32`], and [`LOAD_LIBRARY_SEARCH_USER_DIRS`]. Directories in the
+/// standard search path are not searched. This value cannot be combined with
+/// [`LOAD_WITH_ALTERED_SEARCH_PATH`].
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_SEARCH_DEFAULT_DIRS: DWORD = consts::LOAD_LIBRARY_SEARCH_DEFAULT_DIRS;
+
+/// Directory that contains the DLL is temporarily added to the beginning of the list of
+/// directories that are searched for the DLL’s dependencies.
+///
+/// Directories in the standard search path are not searched.
+///
+/// The `filename` parameter must specify a fully qualified path. This value cannot be combined
+/// with [`LOAD_WITH_ALTERED_SEARCH_PATH`].
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR: DWORD = consts::LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR;
+
+/// Search `%windows%\system32` for the DLL and its dependencies.
+///
+/// Directories in the standard search path are not searched. This value cannot be combined with
+/// [`LOAD_WITH_ALTERED_SEARCH_PATH`].
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_SEARCH_SYSTEM32: DWORD = consts::LOAD_LIBRARY_SEARCH_SYSTEM32;
+
+///  Directories added using the `AddDllDirectory` or the `SetDllDirectory` function are searched
+///  for the DLL and its dependencies.
+///
+///  If more than one directory has been added, the order in which the directories are searched is
+///  unspecified. Directories in the standard search path are not searched. This value cannot be
+///  combined with [`LOAD_WITH_ALTERED_SEARCH_PATH`].
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_SEARCH_USER_DIRS: DWORD = consts::LOAD_LIBRARY_SEARCH_USER_DIRS;
+
+/// If `filename` specifies an absolute path, the system uses the alternate file search strategy
+/// discussed in the [Remarks section] to find associated executable modules that the specified
+/// module causes to be loaded.
+///
+/// If this value is used and `filename` specifies a relative path, the behaviour is undefined.
+///
+/// If this value is not used, or if `filename` does not specify a path, the system uses the
+/// standard search strategy discussed in the [Remarks section] to find associated executable
+/// modules that the specified module causes to be loaded.
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+///
+/// [Remarks]: https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#remarks
+pub const LOAD_WITH_ALTERED_SEARCH_PATH: DWORD = consts::LOAD_WITH_ALTERED_SEARCH_PATH;
+
+/// Specifies that the digital signature of the binary image must be checked at load time.
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_REQUIRE_SIGNED_TARGET: DWORD = consts::LOAD_LIBRARY_REQUIRE_SIGNED_TARGET;
+
+/// Allow loading a DLL for execution from the current directory only if it is under a directory in
+/// the Safe load list.
+///
+/// See [flag documentation on MSDN](https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw#parameters).
+pub const LOAD_LIBRARY_SAFE_CURRENT_DIRS: DWORD = consts::LOAD_LIBRARY_SAFE_CURRENT_DIRS;