deno/cli/windows_util.rs
2022-07-15 12:30:25 -04:00

90 lines
3.3 KiB
Rust

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
/// Ensures that stdin, stdout, and stderr are open and have valid HANDLEs
/// associated with them. There are many places where a `std::fs::File` is
/// constructed from a stdio handle; if the handle is null this causes a panic.
pub fn ensure_stdio_open() {
#[cfg(windows)]
// SAFETY: winapi calls
unsafe {
use std::mem::size_of;
use winapi::shared::minwindef::DWORD;
use winapi::shared::minwindef::FALSE;
use winapi::shared::minwindef::TRUE;
use winapi::shared::ntdef::NULL;
use winapi::shared::winerror::ERROR_INVALID_HANDLE;
use winapi::um::errhandlingapi::GetLastError;
use winapi::um::fileapi::CreateFileA;
use winapi::um::fileapi::OPEN_EXISTING;
use winapi::um::handleapi::GetHandleInformation;
use winapi::um::handleapi::INVALID_HANDLE_VALUE;
use winapi::um::minwinbase::SECURITY_ATTRIBUTES;
use winapi::um::processenv::GetStdHandle;
use winapi::um::processenv::SetStdHandle;
use winapi::um::winbase::STD_ERROR_HANDLE;
use winapi::um::winbase::STD_INPUT_HANDLE;
use winapi::um::winbase::STD_OUTPUT_HANDLE;
use winapi::um::winnt::FILE_ATTRIBUTE_NORMAL;
use winapi::um::winnt::FILE_GENERIC_READ;
use winapi::um::winnt::FILE_GENERIC_WRITE;
use winapi::um::winnt::FILE_READ_ATTRIBUTES;
use winapi::um::winnt::FILE_SHARE_READ;
use winapi::um::winnt::FILE_SHARE_WRITE;
for std_handle in [STD_INPUT_HANDLE, STD_OUTPUT_HANDLE, STD_ERROR_HANDLE] {
// Check whether stdio handle is open.
let is_valid = match GetStdHandle(std_handle) {
NULL | INVALID_HANDLE_VALUE => false,
handle => {
// The stdio handle is open; check whether its handle is valid.
let mut flags: DWORD = 0;
match GetHandleInformation(handle, &mut flags) {
TRUE => true,
FALSE if GetLastError() == ERROR_INVALID_HANDLE => false,
FALSE => {
panic!("GetHandleInformation failed (error {})", GetLastError());
}
_ => unreachable!(),
}
}
};
if !is_valid {
// Open NUL device.
let desired_access = match std_handle {
STD_INPUT_HANDLE => FILE_GENERIC_READ,
_ => FILE_GENERIC_WRITE | FILE_READ_ATTRIBUTES,
};
let security_attributes = SECURITY_ATTRIBUTES {
nLength: size_of::<SECURITY_ATTRIBUTES>() as DWORD,
lpSecurityDescriptor: NULL,
bInheritHandle: TRUE,
};
let file_handle = CreateFileA(
b"\\\\?\\NUL\0" as *const _ as *mut _,
desired_access,
FILE_SHARE_READ | FILE_SHARE_WRITE,
&security_attributes as *const _ as *mut _,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL,
);
match file_handle {
NULL => unreachable!(),
INVALID_HANDLE_VALUE => {
panic!("Could not open NUL device (error {})", GetLastError());
}
_ => {}
}
// Assign the opened NUL handle to the missing stdio handle.
let success = SetStdHandle(std_handle, file_handle);
match success {
TRUE => {}
FALSE => panic!("SetStdHandle failed (error {})", GetLastError()),
_ => unreachable!(),
}
}
}
}
}