1//! This is just a sample of what FFI using this crate can look like.
2
3#![cfg_attr(not(io_safety_is_in_std), allow(unused_imports))]
4#![allow(missing_docs)]
5
6#[cfg(any(unix, target_os = "wasi", target_os = "hermit"))]
7use crate::{BorrowedFd, OwnedFd};
8#[cfg(windows)]
9use crate::{BorrowedHandle, HandleOrInvalid};
10
11#[cfg(any(unix, target_os = "wasi", target_os = "hermit"))]
12use libc::{c_char, c_int, c_void, size_t, ssize_t};
13#[cfg(windows)]
14use {
15 core::ffi::c_void,
16 windows_sys::core::PCWSTR,
17 windows_sys::Win32::Foundation::BOOL,
18 windows_sys::Win32::Security::SECURITY_ATTRIBUTES,
19 windows_sys::Win32::Storage::FileSystem::{
20 FILE_CREATION_DISPOSITION, FILE_FLAGS_AND_ATTRIBUTES, FILE_SHARE_MODE,
21 },
22 windows_sys::Win32::System::IO::OVERLAPPED,
23};
24
25// Declare a few FFI functions ourselves, to show off the FFI ergonomics.
26#[cfg(all(
27 io_safety_is_in_std,
28 any(unix, target_os = "wasi", target_os = "hermit")
29))]
30unsafeextern "C" {
31 pub unsafefn open(pathname: *const c_char, flags: c_int, ...) -> Option<OwnedFd>;
32}
33#[cfg(any(unix, target_os = "wasi"))]
34unsafeextern "C" {
35 pub unsafefn read(fd: BorrowedFd<'_>, ptr: *mut c_void, size: size_t) -> ssize_t;
36 pub unsafefn write(fd: BorrowedFd<'_>, ptr: *const c_void, size: size_t) -> ssize_t;
37}
38#[cfg(any(unix, target_os = "wasi"))]
39pub use libc::{O_CLOEXEC, O_CREAT, O_RDONLY, O_RDWR, O_TRUNC, O_WRONLY};
40
41// The Windows analogs of the above. Note the use of [`HandleOrInvalid`] as
42// the return type for `CreateFileW`, since that function is defined to return
43// [`INVALID_HANDLE_VALUE`] on error instead of null.
44#[cfg(windows)]
45extern "system" {
46 pub fn CreateFileW(
47 lpfilename: PCWSTR,
48 dwdesiredaccess: u32,
49 dwsharemode: FILE_SHARE_MODE,
50 lpsecurityattributes: *const SECURITY_ATTRIBUTES,
51 dwcreationdisposition: FILE_CREATION_DISPOSITION,
52 dwflagsandattributes: FILE_FLAGS_AND_ATTRIBUTES,
53 htemplatefile: HANDLE,
54 ) -> HandleOrInvalid;
55 pub fn ReadFile(
56 hfile: BorrowedHandle<'_>,
57 lpbuffer: *mut c_void,
58 nnumberofbytestoread: u32,
59 lpnumberofbytesread: *mut u32,
60 lpoverlapped: *mut OVERLAPPED,
61 ) -> BOOL;
62 pub fn WriteFile(
63 hfile: BorrowedHandle<'_>,
64 lpbuffer: *const c_void,
65 nnumberofbytestowrite: u32,
66 lpnumberofbyteswritten: *mut u32,
67 lpoverlapped: *mut OVERLAPPED,
68 ) -> BOOL;
69}
70
71#[cfg(windows)]
72pub use {
73 windows_sys::Win32::Foundation::HANDLE,
74 windows_sys::Win32::Storage::FileSystem::{
75 CREATE_ALWAYS, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, FILE_GENERIC_READ, FILE_GENERIC_WRITE,
76 OPEN_EXISTING,
77 },
78};
79