//@ compile-flags:-Cstrip=none
//@ run-fail
//@ check-run-results
//@ exec-env:RUST_BACKTRACE=1
//@ needs-unwind
//@ ignore-android FIXME #17520
//@ ignore-wasm no panic support
//@ ignore-openbsd no support for libbacktrace without filename
//@ ignore-emscripten no panic
//@ ignore-sgx Backtraces not symbolized
//@ ignore-fuchsia Backtraces not symbolized
//@ ignore-msvc the `__rust_{begin,end}_short_backtrace` symbols aren't reliable.


#[inline(never)]
fn __rust_begin_short_backtrace<T, F: FnOnce() -> T>(f: F) -> T {
    let result = f();
    std::hint::black_box(result)
}

#[inline(never)]
fn __rust_end_short_backtrace<T, F: FnOnce() -> T>(f: F) -> T {
    let result = f();
    std::hint::black_box(result)
}

fn first() {
    __rust_end_short_backtrace(|| second());
    // do not take effect since we already has a inner call of __rust_end_short_backtrace
}

fn second() {
    __rust_end_short_backtrace(|| third());
}

fn third() {
    fourth(); // won't show up in backtrace
}

fn fourth() {
    fifth(); // won't show up in backtrace
}

fn fifth() {
    __rust_begin_short_backtrace(|| sixth());
}

fn sixth() {
    seven();
}

fn seven() {
    panic!("debug!!!");
}

fn main() {
    first();
}