bjoernager/rust
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avoid nesting the user-defined main so deeply on the stack

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This commit is contained in:
Ralf Jung 2025-01-11 15:43:43 +01:00
parent 9f7fe81d53
commit 471d830106
5 changed files with 26 additions and 45 deletions
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29
library/std/src/rt.rs
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@ -157,7 +157,7 @@ fn lang_start_internal(
argc: isize,
argv: *const *const u8,
sigpipe: u8,
) -> Result<isize, !> {
) -> isize {
// Guard against the code called by this function from unwinding outside of the Rust-controlled
// code, which is UB. This is a requirement imposed by a combination of how the
// `#[lang="start"]` attribute is implemented as well as by the implementation of the panicking
@ -174,18 +174,24 @@ fn lang_start_internal(
panic::catch_unwind(move || {
// SAFETY: Only called once during runtime initialization.
unsafe { init(argc, argv, sigpipe) };
let ret_code =
panic::catch_unwind(move || panic::catch_unwind(main).unwrap_or(101) as isize).map_err(
move |e| {
// Print a specific error when we abort due to a panicing payload destructor.
mem::forget(e);
rtabort!("drop of the panic payload panicked");
},
);
let ret_code = panic::catch_unwind(main).unwrap_or_else(move |payload| {
// Carefully dispose of the panic payload.
let payload = panic::AssertUnwindSafe(payload);
panic::catch_unwind(move || drop({ payload }.0)).unwrap_or_else(move |e| {
mem::forget(e); // do *not* drop the 2nd payload
rtabort!("drop of the panic payload panicked");
});
// Return error code for panicking programs.
101
});
let ret_code = ret_code as isize;
cleanup();
// Guard against multiple threads calling `libc::exit` concurrently.
// See the documentation for `unique_thread_exit` for more information.
crate::sys::exit_guard::unique_thread_exit();
ret_code
})
.unwrap_or_else(handle_rt_panic)
@ -199,11 +205,10 @@ fn lang_start<T: crate::process::Termination + 'static>(
argv: *const *const u8,
sigpipe: u8,
) -> isize {
let Ok(v) = lang_start_internal(
lang_start_internal(
&move || crate::sys::backtrace::__rust_begin_short_backtrace(main).report().to_i32(),
argc,
argv,
sigpipe,
);
v
)
}