Enable -Z panic-in-drop=abort by default

[Amanieu]

This PR switches the default value of -Z panic-in-drop to abort. This causes Rust programs to abort if a panic escapes from a Drop impl (it is not caught by catch_unwind).

See rust-lang/lang-team#97 for a more detailed rationale on this change.

Most of the changes in this PR involve fixing tests to work with the new behavior. For now, stdlib tests which rely on panics in drop are simply disabled with #[ignore]. However, if in the future we decide to make this change permanent and remove the -Z panic-in-drop=unwind option then we can simplify the implementation of the collections, especially with regards to drain_filter.

r? @joshtriplett

[rust-log-analyzer]

The job x86_64-gnu-llvm-12 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

failures:

---- [incremental] incremental/delayed_span_bug.rs stdout ----

error in revision `cfail1`: Error: expected failure status (Some(101)) but received status None.
status: signal: 6 (core dumped)
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/incremental/delayed_span_bug.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--cfg" "cfail1" "-C" "incremental=/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/delayed_span_bug/delayed_span_bug.inc" "-Z" "incremental-verify-ich" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/delayed_span_bug" "-Crpath" "-O" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/delayed_span_bug/auxiliary"
stdout: none
--- stderr -------------------------------
warning: Error finalizing incremental compilation session directory `/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/delayed_span_bug/delayed_span_bug.inc/delayed_span_bug-3iuktwy7w0wpu/s-g85jft81jz-fkftbz-working`: No such file or directory (os error 2)
warning: 1 warning emitted


error: internal compiler error: no errors encountered even though `delay_span_bug` issued

error: internal compiler error: delayed span bug triggered by #[rustc_error(delay_span_bug_from_inside_query)]
   |
LL | fn main() {}
   | ^^^^^^^^^
   |
   |
   = note: delayed at compiler/rustc_middle/src/util/bug.rs:45:14

thread 'rustc' panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1291:13
stack backtrace:
   0:     0x7f317f0d05f2 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hbaf39c7e135a5f29
   1:     0x7f317f1381bf - core::fmt::write::h17fceefd44a8563d
   2:     0x7f317f0bf803 - std::io::Write::write_fmt::hce4aaa025715dd55
   3:     0x7f317f0d3b9c - std::panicking::default_hook::{{closure}}::h710259246eb13b44
   4:     0x7f317f0d36ed - std::panicking::default_hook::h9c7fbd10a3b26c0c
   5:     0x7f317fb7a3b1 - rustc_driver[8ed9b98a7c93dd6b]::DEFAULT_HOOK::{closure#0}::{closure#0}
   6:     0x7f317f0d45ed - std::panicking::rust_panic_with_hook::hb63e1080147ab8fb
   7:     0x7f31823ab313 - std[45702258e1bbc8d]::panicking::begin_panic::<rustc_errors[9bd6aca994b05f94]::ExplicitBug>::{closure#0}
   8:     0x7f31823aa216 - std[45702258e1bbc8d]::sys_common::backtrace::__rust_end_short_backtrace::<std[45702258e1bbc8d]::panicking::begin_panic<rustc_errors[9bd6aca994b05f94]::ExplicitBug>::{closure#0}, !>
   9:     0x7f317fb3138f - std[45702258e1bbc8d]::panicking::begin_panic::<rustc_errors[9bd6aca994b05f94]::ExplicitBug>
  10:     0x7f31823a0996 - std[45702258e1bbc8d]::panic::panic_any::<rustc_errors[9bd6aca994b05f94]::ExplicitBug>
  11:     0x7f31823a4d32 - <rustc_errors[9bd6aca994b05f94]::HandlerInner as core[a65aa9227bae4abc]::ops::drop::Drop>::drop
  12:     0x7f317fb8fea0 - <alloc[d149d8c8d6a713e7]::rc::Rc<rustc_session[d666950372548c5f]::session::Session> as core[a65aa9227bae4abc]::ops::drop::Drop>::drop
  13:     0x7f317fbccf49 - core[a65aa9227bae4abc]::ptr::drop_in_place::<rustc_interface[f56f2f0b26d6c35e]::interface::Compiler>
  14:     0x7f317fbc9e57 - rustc_span[6d3d3d5a9e908e9c]::with_source_map::<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_interface[f56f2f0b26d6c35e]::interface::create_compiler_and_run<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#1}>
  15:     0x7f317fbbc0b0 - <scoped_tls[433840387f49a653]::ScopedKey<rustc_span[6d3d3d5a9e908e9c]::SessionGlobals>>::set::<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>
  16:     0x7f317fb8c249 - std[45702258e1bbc8d]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[f56f2f0b26d6c35e]::util::run_in_thread_pool_with_globals<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>
  17:     0x7f317fbd6a31 - std[45702258e1bbc8d]::panicking::try::<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, core[a65aa9227bae4abc]::panic::unwind_safe::AssertUnwindSafe<<std[45702258e1bbc8d]::thread::Builder>::spawn_unchecked_<rustc_interface[f56f2f0b26d6c35e]::util::run_in_thread_pool_with_globals<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#1}::{closure#0}>>
  18:     0x7f317fbcf271 - <<std[45702258e1bbc8d]::thread::Builder>::spawn_unchecked_<rustc_interface[f56f2f0b26d6c35e]::util::run_in_thread_pool_with_globals<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#1} as core[a65aa9227bae4abc]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  19:     0x7f317f0dfa43 - std::sys::unix::thread::Thread::new::thread_start::hb758e3f4652c5e3b
  20:     0x7f317962b609 - start_thread
  21:     0x7f317ef3e163 - clone
  22:                0x0 - <unknown>
note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md


note: rustc 1.61.0-nightly (8ab5939ba 2022-03-22) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z threads=1 -C incremental -Z incremental -Z ui-testing -Z deduplicate-diagnostics=no -C prefer-dynamic -C rpath -C debuginfo=0
query stack during panic:
end of query stack
thread 'rustc' panicked at 'panic in a function that cannot unwind', library/core/src/panicking.rs:107:58
stack backtrace:
stack backtrace:
   0:     0x7f317f0d05f2 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hbaf39c7e135a5f29
   1:     0x7f317f1381bf - core::fmt::write::h17fceefd44a8563d
   2:     0x7f317f0bf803 - std::io::Write::write_fmt::hce4aaa025715dd55
   3:     0x7f317f0d3b9c - std::panicking::default_hook::{{closure}}::h710259246eb13b44
   4:     0x7f317f0d36ed - std::panicking::default_hook::h9c7fbd10a3b26c0c
   5:     0x7f317fb7a3b1 - rustc_driver[8ed9b98a7c93dd6b]::DEFAULT_HOOK::{closure#0}::{closure#0}
   6:     0x7f317f0d45ed - std::panicking::rust_panic_with_hook::hb63e1080147ab8fb
   7:     0x7f317f0d4319 - std::panicking::begin_panic_handler::{{closure}}::h28de1e26006d66f9
   8:     0x7f317f0d0b14 - std::sys_common::backtrace::__rust_end_short_backtrace::h26ee2e41c2c2875a
   9:     0x7f317f0d4039 - rust_begin_unwind
  10:     0x7f317f080b7b - core::panicking::panic_no_unwind::hdd8236a91374a97f
  11:     0x7f317fb9038e - <alloc[d149d8c8d6a713e7]::rc::Rc<rustc_session[d666950372548c5f]::session::Session> as core[a65aa9227bae4abc]::ops::drop::Drop>::drop
  12:     0x7f317fbccf49 - core[a65aa9227bae4abc]::ptr::drop_in_place::<rustc_interface[f56f2f0b26d6c35e]::interface::Compiler>
  13:     0x7f317fbc9e57 - rustc_span[6d3d3d5a9e908e9c]::with_source_map::<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_interface[f56f2f0b26d6c35e]::interface::create_compiler_and_run<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#1}>
  14:     0x7f317fbbc0b0 - <scoped_tls[433840387f49a653]::ScopedKey<rustc_span[6d3d3d5a9e908e9c]::SessionGlobals>>::set::<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>
  15:     0x7f317fb8c249 - std[45702258e1bbc8d]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[f56f2f0b26d6c35e]::util::run_in_thread_pool_with_globals<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>
  16:     0x7f317fbd6a31 - std[45702258e1bbc8d]::panicking::try::<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, core[a65aa9227bae4abc]::panic::unwind_safe::AssertUnwindSafe<<std[45702258e1bbc8d]::thread::Builder>::spawn_unchecked_<rustc_interface[f56f2f0b26d6c35e]::util::run_in_thread_pool_with_globals<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#1}::{closure#0}>>
  17:     0x7f317fbcf271 - <<std[45702258e1bbc8d]::thread::Builder>::spawn_unchecked_<rustc_interface[f56f2f0b26d6c35e]::util::run_in_thread_pool_with_globals<rustc_interface[f56f2f0b26d6c35e]::interface::run_compiler<core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>, rustc_driver[8ed9b98a7c93dd6b]::run_compiler::{closure#1}>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#0}, core[a65aa9227bae4abc]::result::Result<(), rustc_errors[9bd6aca994b05f94]::ErrorGuaranteed>>::{closure#1} as core[a65aa9227bae4abc]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  18:     0x7f317f0dfa43 - std::sys::unix::thread::Thread::new::thread_start::hb758e3f4652c5e3b
  19:     0x7f317962b609 - start_thread
  20:     0x7f317ef3e163 - clone
  21:                0x0 - <unknown>
error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.


note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.61.0-nightly (8ab5939ba 2022-03-22) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z threads=1 -C incremental -Z incremental -Z ui-testing -Z deduplicate-diagnostics=no -C prefer-dynamic -C rpath -C debuginfo=0
query stack during panic:
end of query stack
thread panicked while panicking. aborting.
------------------------------------------

[bjorn3]

Looks like this causes delay_span_bug to abort the process if it triggers rather than continue unwinding to the main entry point of rustc_driver and return an error value.

[Amanieu]

So this seems to be due to the unfortunate design of rustc_error::Handler which emits delayed diagnostics from its Drop impl. I can think of 2 ways to solve this:

• Compile rustc with panic=abort so that we abort immediately instead of propagating a panic up to rustc_driver (at which point it just exits anyways).
• Rework Handler so that it works as a scope (similar to scoped threads Tracking Issue for scoped threads #93203). Delayed diagnostics are only emitted if the scope ends normally (not panicking). This is a more involved change since Handler is somewhat widely used in rustc.

[bors]

☔ The latest upstream changes (presumably #96622) made this pull request unmergeable. Please resolve the merge conflicts.

[Dylan-DPC]

Closing this as inactive