std\sys\pal\windows/stack_overflow.rs
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#![cfg_attr(test, allow(dead_code))]
use crate::sys::c;
use crate::thread;
/// Reserve stack space for use in stack overflow exceptions.
pub fn reserve_stack() {
let result = unsafe { c::SetThreadStackGuarantee(&mut 0x5000) };
// Reserving stack space is not critical so we allow it to fail in the released build of libstd.
// We still use debug assert here so that CI will test that we haven't made a mistake calling the function.
debug_assert_ne!(result, 0, "failed to reserve stack space for exception handling");
}
unsafe extern "system" fn vectored_handler(ExceptionInfo: *mut c::EXCEPTION_POINTERS) -> i32 {
// SAFETY: It's up to the caller (which in this case is the OS) to ensure that `ExceptionInfo` is valid.
unsafe {
let rec = &(*(*ExceptionInfo).ExceptionRecord);
let code = rec.ExceptionCode;
if code == c::EXCEPTION_STACK_OVERFLOW {
rtprintpanic!(
"\nthread '{}' has overflowed its stack\n",
thread::current().name().unwrap_or("<unknown>")
);
}
c::EXCEPTION_CONTINUE_SEARCH
}
}
pub fn init() {
// SAFETY: `vectored_handler` has the correct ABI and is safe to call during exception handling.
unsafe {
let result = c::AddVectoredExceptionHandler(0, Some(vectored_handler));
// Similar to the above, adding the stack overflow handler is allowed to fail
// but a debug assert is used so CI will still test that it normally works.
debug_assert!(!result.is_null(), "failed to install exception handler");
}
// Set the thread stack guarantee for the main thread.
reserve_stack();
}