diff --git a/library/std/src/rt.rs b/library/std/src/rt.rs index b2492238bd37b..24a362072ab61 100644 --- a/library/std/src/rt.rs +++ b/library/std/src/rt.rs @@ -67,7 +67,7 @@ macro_rules! rtunwrap { }; } -fn handle_rt_panic(e: Box) { +fn handle_rt_panic(e: Box) -> T { mem::forget(e); rtabort!("initialization or cleanup bug"); } @@ -157,7 +157,7 @@ fn lang_start_internal( argc: isize, argv: *const *const u8, sigpipe: u8, -) -> Result { +) -> 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 @@ -168,19 +168,33 @@ fn lang_start_internal( // panic is a std implementation bug. A quite likely one too, as there isn't any way to // prevent std from accidentally introducing a panic to these functions. Another is from // user code from `main` or, more nefariously, as described in e.g. issue #86030. - // SAFETY: Only called once during runtime initialization. - panic::catch_unwind(move || unsafe { init(argc, argv, sigpipe) }) - .unwrap_or_else(handle_rt_panic); - let ret_code = panic::catch_unwind(move || panic::catch_unwind(main).unwrap_or(101) as isize) - .map_err(move |e| { - mem::forget(e); - rtabort!("drop of the panic payload panicked"); + // + // We use `catch_unwind` with `handle_rt_panic` instead of `abort_unwind` to make the error in + // case of a panic a bit nicer. + panic::catch_unwind(move || { + // SAFETY: Only called once during runtime initialization. + unsafe { init(argc, argv, sigpipe) }; + + 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 }); - panic::catch_unwind(cleanup).unwrap_or_else(handle_rt_panic); - // Guard against multiple threads calling `libc::exit` concurrently. - // See the documentation for `unique_thread_exit` for more information. - panic::catch_unwind(crate::sys::exit_guard::unique_thread_exit).unwrap_or_else(handle_rt_panic); - ret_code + 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) } #[cfg(not(any(test, doctest)))] @@ -191,11 +205,10 @@ fn lang_start( 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 + ) } diff --git a/src/tools/miri/tests/fail/tail_calls/cc-mismatch.stderr b/src/tools/miri/tests/fail/tail_calls/cc-mismatch.stderr index b416f0eb68976..5061c9e8dc3f0 100644 --- a/src/tools/miri/tests/fail/tail_calls/cc-mismatch.stderr +++ b/src/tools/miri/tests/fail/tail_calls/cc-mismatch.stderr @@ -15,9 +15,9 @@ LL | extern "rust-call" fn call_once(self, args: Args) -> Self::Output; = note: inside `std::panicking::r#try:: i32 + std::marker::Sync + std::panic::RefUnwindSafe>` at RUSTLIB/std/src/panicking.rs:LL:CC = note: inside `std::panic::catch_unwind::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at RUSTLIB/std/src/panic.rs:LL:CC = note: inside closure at RUSTLIB/std/src/rt.rs:LL:CC - = note: inside `std::panicking::r#try::do_call::<{closure@std::rt::lang_start_internal::{closure#1}}, isize>` at RUSTLIB/std/src/panicking.rs:LL:CC - = note: inside `std::panicking::r#try::` at RUSTLIB/std/src/panicking.rs:LL:CC - = note: inside `std::panic::catch_unwind::<{closure@std::rt::lang_start_internal::{closure#1}}, isize>` at RUSTLIB/std/src/panic.rs:LL:CC + = note: inside `std::panicking::r#try::do_call::<{closure@std::rt::lang_start_internal::{closure#0}}, isize>` at RUSTLIB/std/src/panicking.rs:LL:CC + = note: inside `std::panicking::r#try::` at RUSTLIB/std/src/panicking.rs:LL:CC + = note: inside `std::panic::catch_unwind::<{closure@std::rt::lang_start_internal::{closure#0}}, isize>` at RUSTLIB/std/src/panic.rs:LL:CC = note: inside `std::rt::lang_start_internal` at RUSTLIB/std/src/rt.rs:LL:CC = note: inside `std::rt::lang_start::<()>` at RUSTLIB/std/src/rt.rs:LL:CC diff --git a/src/tools/miri/tests/pass/backtrace/backtrace-api-v1.stderr b/src/tools/miri/tests/pass/backtrace/backtrace-api-v1.stderr index 48d9649c9201f..1ee5298f17d63 100644 --- a/src/tools/miri/tests/pass/backtrace/backtrace-api-v1.stderr +++ b/src/tools/miri/tests/pass/backtrace/backtrace-api-v1.stderr @@ -10,7 +10,7 @@ RUSTLIB/core/src/ops/function.rs:LL:CC (std::ops::function::impls::call_once) RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try::do_call) RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try) RUSTLIB/std/src/panic.rs:LL:CC (std::panic::catch_unwind) -RUSTLIB/std/src/rt.rs:LL:CC (std::rt::lang_start_internal::{closure#1}) +RUSTLIB/std/src/rt.rs:LL:CC (std::rt::lang_start_internal::{closure#0}) RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try::do_call) RUSTLIB/std/src/panicking.rs:LL:CC (std::panicking::r#try) RUSTLIB/std/src/panic.rs:LL:CC (std::panic::catch_unwind) diff --git a/src/tools/miri/tests/pass/backtrace/backtrace-global-alloc.stderr b/src/tools/miri/tests/pass/backtrace/backtrace-global-alloc.stderr index 667ee04e62413..26cdee18e3c23 100644 --- a/src/tools/miri/tests/pass/backtrace/backtrace-global-alloc.stderr +++ b/src/tools/miri/tests/pass/backtrace/backtrace-global-alloc.stderr @@ -14,7 +14,7 @@ at RUSTLIB/std/src/panicking.rs:LL:CC 7: std::panic::catch_unwind at RUSTLIB/std/src/panic.rs:LL:CC - 8: std::rt::lang_start_internal::{closure#1} + 8: std::rt::lang_start_internal::{closure#0} at RUSTLIB/std/src/rt.rs:LL:CC 9: std::panicking::r#try::do_call at RUSTLIB/std/src/panicking.rs:LL:CC diff --git a/src/tools/miri/tests/pass/backtrace/backtrace-std.stderr b/src/tools/miri/tests/pass/backtrace/backtrace-std.stderr index b3a3a9d654a78..d89ae3837b981 100644 --- a/src/tools/miri/tests/pass/backtrace/backtrace-std.stderr +++ b/src/tools/miri/tests/pass/backtrace/backtrace-std.stderr @@ -22,7 +22,7 @@ at RUSTLIB/std/src/panicking.rs:LL:CC 11: std::panic::catch_unwind at RUSTLIB/std/src/panic.rs:LL:CC - 12: std::rt::lang_start_internal::{closure#1} + 12: std::rt::lang_start_internal::{closure#0} at RUSTLIB/std/src/rt.rs:LL:CC 13: std::panicking::r#try::do_call at RUSTLIB/std/src/panicking.rs:LL:CC