std/sys/pal/unix/stack_overflow/
mod.rs

1#![cfg_attr(test, allow(dead_code))]
2#![forbid(unsafe_op_in_unsafe_fn)]
3
4cfg_select! {
5    // This is intentionally not enabled on iOS/tvOS/watchOS/visionOS, as it uses
6    // several symbols that might lead to rejections from the App Store, namely
7    // `sigaction`, `sigaltstack`, `sysctlbyname`, `mmap`, `munmap` and `mprotect`.
8    //
9    // This might be overly cautious, though it is also what Swift does (and they
10    // usually have fewer qualms about forwards compatibility, since the runtime
11    // is shipped with the OS):
12    // <https://github.com/apple/swift/blob/swift-5.10-RELEASE/stdlib/public/runtime/CrashHandlerMacOS.cpp>
13    any(
14        target_os = "linux",
15        target_os = "freebsd",
16        target_os = "hurd",
17        target_os = "macos",
18        target_os = "netbsd",
19        target_os = "openbsd",
20        target_os = "solaris",
21        target_os = "illumos",
22    ) => {
23        mod handler_signal;
24        mod thread_info;
25        use handler_signal as imp;
26    }
27    target_os = "cygwin" => {
28        mod handler_cygwin;
29        use handler_cygwin as imp;
30    }
31    _ => {
32        mod handler_none;
33        use handler_none as imp;
34    }
35}
36
37/// # Safety
38/// Must be called only once, on the main thread, during program startup.
39pub unsafe fn init() {
40    // miri doesn't model signals nor stack overflows and this code has some
41    // synchronization properties that we don't want to expose to user code,
42    // hence we disable it on miri.
43    if cfg!(miri) {
44        return;
45    }
46
47    // SAFETY: guaranteed by caller.
48    unsafe { imp::init() };
49}
50
51pub struct Handler {
52    data: *mut libc::c_void,
53}
54
55impl Handler {
56    pub unsafe fn new() -> Handler {
57        // The stack overflow detection logic, even if disabled, has some
58        // synchronization logic that should be disabled under miri.
59        if cfg!(miri) {
60            return Handler::null();
61        }
62
63        imp::make_handler(false)
64    }
65
66    fn null() -> Handler {
67        Handler { data: crate::ptr::null_mut() }
68    }
69}
70
71impl Drop for Handler {
72    fn drop(&mut self) {
73        // The stack overflow detection logic, even if disabled, has some
74        // synchronization logic that should be disabled under miri.
75        if cfg!(miri) {
76            return;
77        }
78
79        unsafe { imp::drop_handler(self.data) };
80    }
81}
std/sys/pal/unix/stack_overflow/mod.rs

std/sys/pal/unix/stack_overflow/
mod.rs
