Collect and emit proper backtraces for `delay_span_bug`s #106321

compiler-errors · 2022-12-31T02:21:40Z

This is a follow-up to #106317, which addresses this comment (#106267 (comment)) which notes that delay_span_bugs' backtraces are nonsense.

Captures and emits the backtrace of the delayed span bug when it's created, rather than using the backtrace of the place where delayed bugs are flushed.

To test, I delayed a span bug during HIR typeck, specifically in typeck_with_fallback...

Before, note flush_delayed on frame 18. This is at the end of the compilation session, far from where the bug is being delayed.

error: internal compiler error: test
 --> /home/ubuntu/test.rs:1:1
  |
1 | fn main() {}
  | ^^^^^^^^^
  |
  = note: delayed at compiler/rustc_hir_typeck/src/lib.rs:196:14

thread 'rustc' panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1634:13
stack backtrace:
   0:     0x7f9c3ec69dd1 - std::backtrace_rs::backtrace::libunwind::trace::h26056f81198c6594
                               at /home/ubuntu/rust2/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f9c3ec69dd1 - std::backtrace_rs::backtrace::trace_unsynchronized::hacfb345a0c6d5bb1
                               at /home/ubuntu/rust2/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f9c3ec69dd1 - std::sys_common::backtrace::_print_fmt::h18ea6016ac8030f3
                               at /home/ubuntu/rust2/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f9c3ec69dd1 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::he35dde201d0c2d09
                               at /home/ubuntu/rust2/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f9c3ecee308 - core::fmt::write::h094ad263467a053c
                               at /home/ubuntu/rust2/library/core/src/fmt/mod.rs:1208:17
   5:     0x7f9c3ec8aaf1 - std::io::Write::write_fmt::hd47b4e2324b4d9b7
                               at /home/ubuntu/rust2/library/std/src/io/mod.rs:1682:15
   6:     0x7f9c3ec69bfa - std::sys_common::backtrace::_print::h43044162653a17fc
                               at /home/ubuntu/rust2/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7f9c3ec69bfa - std::sys_common::backtrace::print::hc8605da258fa5aeb
                               at /home/ubuntu/rust2/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7f9c3ec4db87 - std::panicking::default_hook::{{closure}}::h9e37f23f75122a15
   9:     0x7f9c3ec4d97b - std::panicking::default_hook::h602873a063f84da2
                               at /home/ubuntu/rust2/library/std/src/panicking.rs:286:9
  10:     0x7f9c3f6672b2 - <alloc[48d7b30605060536]::boxed::Box<dyn for<'a, 'b> core[672e3947e150d6c6]::ops::function::Fn<(&'a core[672e3947e150d6c6]::panic::panic_info::PanicInfo<'b>,), Output = ()> + core[672e3947e150d6c6]::marker::Send + core[672e3947e150d6c6]::marker::Sync> as core[672e3947e150d6c6]::ops::function::Fn<(&core[672e3947e150d6c6]::panic::panic_info::PanicInfo,)>>::call
                               at /home/ubuntu/rust2/library/alloc/src/boxed.rs:2002:9
  11:     0x7f9c3f6672b2 - rustc_driver[f5b6d32d8905ecdd]::DEFAULT_HOOK::{closure#0}::{closure#0}
                               at /home/ubuntu/rust2/compiler/rustc_driver/src/lib.rs:1204:17
  12:     0x7f9c3ec4e0d3 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hfd13333ca953ae8e
                               at /home/ubuntu/rust2/library/alloc/src/boxed.rs:2002:9
  13:     0x7f9c3ec4e0d3 - std::panicking::rust_panic_with_hook::h45753e10264ebe7e
                               at /home/ubuntu/rust2/library/std/src/panicking.rs:692:13
  14:     0x7f9c422a1aa3 - std[3330b4673efabfce]::panicking::begin_panic::<rustc_errors[1b15f4e7e49d1fd5]::ExplicitBug>::{closure#0}
                               at /home/ubuntu/rust2/library/std/src/panicking.rs:608:9
  15:     0x7f9c422a1a46 - std[3330b4673efabfce]::sys_common::backtrace::__rust_end_short_backtrace::<std[3330b4673efabfce]::panicking::begin_panic<rustc_errors[1b15f4e7e49d1fd5]::ExplicitBug>::{closure#0}, !>
                               at /home/ubuntu/rust2/library/std/src/sys_common/backtrace.rs:137:18
  16:     0x7f9c3f63a996 - std[3330b4673efabfce]::panicking::begin_panic::<rustc_errors[1b15f4e7e49d1fd5]::ExplicitBug>
                               at /home/ubuntu/rust2/library/std/src/panicking.rs:607:12
  17:     0x7f9c4227a496 - std[3330b4673efabfce]::panic::panic_any::<rustc_errors[1b15f4e7e49d1fd5]::ExplicitBug>
                               at /home/ubuntu/rust2/library/std/src/panic.rs:61:5
  18:     0x7f9c4227cdf7 - <rustc_errors[1b15f4e7e49d1fd5]::HandlerInner>::flush_delayed::<alloc[48d7b30605060536]::vec::Vec<rustc_errors[1b15f4e7e49d1fd5]::diagnostic::Diagnostic>, &str, rustc_errors[1b15f4e7e49d1fd5]::ExplicitBug>
                               at /home/ubuntu/rust2/compiler/rustc_errors/src/lib.rs:1634:13
  19:     0x7f9c422498cf - <rustc_errors[1b15f4e7e49d1fd5]::Handler>::flush_delayed
                               at /home/ubuntu/rust2/compiler/rustc_errors/src/lib.rs:1225:9
 
[ FRAMES INTENTIONALLY OMITTED ]

  44:     0x7f9c3f6f3584 - <std[3330b4673efabfce]::thread::Builder>::spawn_unchecked_::<rustc_interface[947706ead88047d0]::util::run_in_thread_pool_with_globals<rustc_interface[947706ead88047d0]::interface::run_compiler<core[672e3947e150d6c6]::result::Result<(), rustc_errors[1b15f4e7e49d1fd5]::ErrorGuaranteed>, rustc_driver[f5b6d32d8905ecdd]::run_compiler::{closure#1}>::{closure#0}, core[672e3947e150d6c6]::result::Result<(), rustc_errors[1b15f4e7e49d1fd5]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[672e3947e150d6c6]::result::Result<(), rustc_errors[1b15f4e7e49d1fd5]::ErrorGuaranteed>>::{closure#1}
                               at /home/ubuntu/rust2/library/std/src/thread/mod.rs:549:30
  45:     0x7f9c3f6f3584 - <<std[3330b4673efabfce]::thread::Builder>::spawn_unchecked_<rustc_interface[947706ead88047d0]::util::run_in_thread_pool_with_globals<rustc_interface[947706ead88047d0]::interface::run_compiler<core[672e3947e150d6c6]::result::Result<(), rustc_errors[1b15f4e7e49d1fd5]::ErrorGuaranteed>, rustc_driver[f5b6d32d8905ecdd]::run_compiler::{closure#1}>::{closure#0}, core[672e3947e150d6c6]::result::Result<(), rustc_errors[1b15f4e7e49d1fd5]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[672e3947e150d6c6]::result::Result<(), rustc_errors[1b15f4e7e49d1fd5]::ErrorGuaranteed>>::{closure#1} as core[672e3947e150d6c6]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
                               at /home/ubuntu/rust2/library/core/src/ops/function.rs:250:5
  46:     0x7f9c3ec81968 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::he8b26fc22c6f51ec
                               at /home/ubuntu/rust2/library/alloc/src/boxed.rs:1988:9
  47:     0x7f9c3ec81968 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h5cf9cbe75a8c3ddc
                               at /home/ubuntu/rust2/library/alloc/src/boxed.rs:1988:9
  48:     0x7f9c3ec5f99c - std::sys::unix::thread::Thread::new::thread_start::h2d6dd4455e97d031
                               at /home/ubuntu/rust2/library/std/src/sys/unix/thread.rs:108:17
  49:     0x7f9c37c69609 - start_thread
  50:     0x7f9c3ead0133 - clone
  51:                0x0 - <unknown>

After, note typeck_with_fallback on the 5th frame, that's where we actually need to be pointed to:

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

error: internal compiler error: test
 --> /home/ubuntu/test.rs:1:1
  |
1 | fn main() {}
  | ^^^^^^^^^
  |
  = note: delayed at    0: <rustc_errors::HandlerInner>::emit_diagnostic
                       at ./compiler/rustc_errors/src/lib.rs:1279:29
             1: <rustc_errors::HandlerInner>::delay_span_bug::<rustc_span::span_encoding::Span, &str>
                       at ./compiler/rustc_errors/src/lib.rs:1553:9
             2: <rustc_errors::Handler>::delay_span_bug::<rustc_span::span_encoding::Span, &str>
                       at ./compiler/rustc_errors/src/lib.rs:995:9
             3: <rustc_session::session::Session>::delay_span_bug::<rustc_span::span_encoding::Span, &str>
                       at ./compiler/rustc_session/src/session.rs:600:9
             4: rustc_hir_typeck::typeck_with_fallback::<rustc_hir_typeck::typeck::{closure#0}>::{closure#0}
                       at ./compiler/rustc_hir_typeck/src/lib.rs:196:5
             5: rustc_hir_typeck::typeck_with_fallback::<rustc_hir_typeck::typeck::{closure#0}>
                       at ./compiler/rustc_hir_typeck/src/lib.rs:185:36
             6: rustc_hir_typeck::typeck
                       at ./compiler/rustc_hir_typeck/src/lib.rs:166:9

[ FRAMES INTENTIONALLY OMITTED ]

           108: std::panicking::try::<core::result::Result<(), rustc_errors::ErrorGuaranteed>, core::panic::unwind_safe::AssertUnwindSafe<<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#1}::{closure#0}>>
                       at ./library/std/src/panicking.rs:447:19
           109: std::panic::catch_unwind::<core::panic::unwind_safe::AssertUnwindSafe<<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#1}::{closure#0}>, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
                       at ./library/std/src/panic.rs:140:14
           110: <std::thread::Builder>::spawn_unchecked_::<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#1}
                       at ./library/std/src/thread/mod.rs:549:30
           111: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
                       at ./library/core/src/ops/function.rs:250:5
           112: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
                       at ./library/alloc/src/boxed.rs:1988:9
           113: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
                       at ./library/alloc/src/boxed.rs:1988:9
           114: std::sys::unix::thread::Thread::new::thread_start
                       at ./library/std/src/sys/unix/thread.rs:108:17
           115: start_thread
           116: clone

rustbot · 2022-12-31T02:21:46Z

r? @TaKO8Ki

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compiler/rustc_errors/src/lib.rs

Noratrieb · 2023-01-10T11:41:35Z

r? Nilstrieb
@bors r+

I would like if we had a better way to test ICE messages in general (delayed bugs and also other kinds of ICEs), maybe some kind of -Z flag, but we can do that in a follow-up PR since we currently don't really have anything.

bors · 2023-01-10T11:41:37Z

📌 Commit 05c1ac0 has been approved by Nilstrieb

It is now in the queue for this repository.

bors · 2023-01-10T11:41:38Z

🌲 The tree is currently closed for pull requests below priority 50. This pull request will be tested once the tree is reopened.

Rollup of 9 pull requests Successful merges: - rust-lang#106321 (Collect and emit proper backtraces for `delay_span_bug`s) - rust-lang#106397 (Check `impl`'s `where` clauses in `consider_impl_candidate` in experimental solver) - rust-lang#106427 (Improve fluent error messages) - rust-lang#106570 (add tests for div_duration_* functions) - rust-lang#106648 (Polymorphization cleanup) - rust-lang#106664 (Remove unnecessary lseek syscall when using std::fs::read) - rust-lang#106709 (Disable "split dwarf inlining" by default.) - rust-lang#106715 (Autolabel and ping wg for changes to new solver) - rust-lang#106717 (fix typo LocalItemId -> ItemLocalId) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup

pnkfelix · 2023-01-18T17:28:58Z

oddly, this appears to have injected a slight regression according to the timing results presented on rollup PR #106730.

it may well be noise, though.

compiler-errors · 2023-01-18T17:32:38Z

As @Nilstrieb said, I'm inclined to believe this is noise because this code is on the error path only. We never delay span bugs without fatally exiting.

rustbot assigned TaKO8Ki Dec 31, 2022

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Dec 31, 2022

compiler-errors mentioned this pull request Dec 31, 2022

backtrace missing when rustc panics #106267

Closed

WaffleLapkin reviewed Dec 31, 2022

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compiler/rustc_errors/src/lib.rs Outdated Show resolved Hide resolved

compiler-errors force-pushed the delayed-bug-backtrace branch from 53ffff4 to 7bab33a Compare December 31, 2022 05:51

Collect backtraces for delayed span-bugs too

05c1ac0

compiler-errors force-pushed the delayed-bug-backtrace branch from 7bab33a to 05c1ac0 Compare January 9, 2023 22:04

rustbot assigned Noratrieb Jan 10, 2023

rustbot unassigned TaKO8Ki Jan 10, 2023

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jan 10, 2023

Noratrieb mentioned this pull request Jan 11, 2023

Rollup of 9 pull requests #106730

Merged

bors merged commit 0681a96 into rust-lang:master Jan 11, 2023

rustbot added this to the 1.68.0 milestone Jan 11, 2023

compiler-errors deleted the delayed-bug-backtrace branch August 11, 2023 19:58

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Collect and emit proper backtraces for `delay_span_bug`s #106321

Collect and emit proper backtraces for `delay_span_bug`s #106321

compiler-errors commented Dec 31, 2022

rustbot commented Dec 31, 2022

Noratrieb commented Jan 10, 2023

bors commented Jan 10, 2023

bors commented Jan 10, 2023

pnkfelix commented Jan 18, 2023

compiler-errors commented Jan 18, 2023 •

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Collect and emit proper backtraces for delay_span_bugs #106321

Collect and emit proper backtraces for delay_span_bugs #106321

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compiler-errors commented Dec 31, 2022

rustbot commented Dec 31, 2022

Noratrieb commented Jan 10, 2023

bors commented Jan 10, 2023

bors commented Jan 10, 2023

pnkfelix commented Jan 18, 2023

compiler-errors commented Jan 18, 2023 • edited Loading

Collect and emit proper backtraces for `delay_span_bug`s #106321

Collect and emit proper backtraces for `delay_span_bug`s #106321

compiler-errors commented Jan 18, 2023 •

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