ICE: issue-37725.rs -Zmir-opt-level=2 --emit mir

[matthiaskrgr]

interestingly this one only crashes with -Zmir-opt-level=2 AND --emit mir

Code

./src/test/ui/issues/issue-37725.rs

// build-pass
#![allow(dead_code)]
trait Foo {
    fn foo(&self);
}

fn foo<'a>(s: &'a mut ()) where &'a mut (): Foo {
    s.foo();
}
fn main() {}

Meta

rustc --version --verbose:

rustc 1.49.0-nightly (98edd1fbf 2020-10-06)
binary: rustc
commit-hash: 98edd1fbf8a68977a2a7c1312eb1ebff80515a92
commit-date: 2020-10-06
host: x86_64-unknown-linux-gnu
release: 1.49.0-nightly
LLVM version: 11.0

Error output

error: internal compiler error: Encountered error `Unimplemented` selecting `Binder(<&mut () as Foo>)` during codegen
  |
  = note: delayed at compiler/rustc_trait_selection/src/traits/codegen/mod.rs:65:32

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', compiler/rustc_errors/src/lib.rs:961:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

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 1.49.0-nightly (98edd1fbf 2020-10-06) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=2

Backtrace

error: internal compiler error: Encountered error `Unimplemented` selecting `Binder(<&mut () as Foo>)` during codegen
  |
  = note: delayed at compiler/rustc_trait_selection/src/traits/codegen/mod.rs:65:32

thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', compiler/rustc_errors/src/lib.rs:961:13
stack backtrace:
   0:     0x7fdf59d2b0b0 - std::backtrace_rs::backtrace::libunwind::trace::h622bab51c72c4e69
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/../../backtrace/src/backtrace/libunwind.rs:96
   1:     0x7fdf59d2b0b0 - std::backtrace_rs::backtrace::trace_unsynchronized::h7e820b882ebd41ee
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/../../backtrace/src/backtrace/mod.rs:66
   2:     0x7fdf59d2b0b0 - std::sys_common::backtrace::_print_fmt::h64d46258114db92f
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:79
   3:     0x7fdf59d2b0b0 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h47111d0c1b5f0da5
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:58
   4:     0x7fdf59d9a07c - core::fmt::write::h1857a60b204f1b6a
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/core/src/fmt/mod.rs:1080
   5:     0x7fdf59d1d052 - std::io::Write::write_fmt::h4604516fed3e5731
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/io/mod.rs:1516
   6:     0x7fdf59d2fe7d - std::sys_common::backtrace::_print::h785e7a78d5ef272c
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:61
   7:     0x7fdf59d2fe7d - std::sys_common::backtrace::print::h108047ac5c4555d5
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:48
   8:     0x7fdf59d2fe7d - std::panicking::default_hook::{{closure}}::h1d0c271f0d087ebf
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:208
   9:     0x7fdf59d2fb28 - std::panicking::default_hook::h692753e26f11b7b7
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:227
  10:     0x7fdf5a5bd3e8 - rustc_driver::report_ice::h767ab601e5f63209
  11:     0x7fdf59d306c6 - std::panicking::rust_panic_with_hook::h74ddc20305301cd9
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:581
  12:     0x7fdf59d30249 - std::panicking::begin_panic_handler::{{closure}}::h1a9ca6427ceee1d0
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:484
  13:     0x7fdf59d2b54c - std::sys_common::backtrace::__rust_end_short_backtrace::h97e27b7ab754adde
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:153
  14:     0x7fdf59d30209 - rust_begin_unwind
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:483
  15:     0x7fdf59d301bb - std::panicking::begin_panic_fmt::h45d0f154d1dd3395
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:437
  16:     0x7fdf5d5d9281 - rustc_errors::HandlerInner::flush_delayed::h4e44ea29efc5a508
  17:     0x7fdf5d5d5be1 - <rustc_errors::HandlerInner as core::ops::drop::Drop>::drop::hc2218eb325dc8425
  18:     0x7fdf5a60ad76 - core::ptr::drop_in_place::he652386dc31d9e30
  19:     0x7fdf5a60cbc6 - <alloc::rc::Rc<T> as core::ops::drop::Drop>::drop::h60c7e2432b201062
  20:     0x7fdf5a5e66fd - core::ptr::drop_in_place::h2f4d4236293b18c7
  21:     0x7fdf5a5e0dea - rustc_span::with_source_map::h23e56868796f6dc3
  22:     0x7fdf5a615ed2 - rustc_interface::interface::create_compiler_and_run::h9a8debbb19483b80
  23:     0x7fdf5a5f4d0a - scoped_tls::ScopedKey<T>::set::hacc47b1cdb25a215
  24:     0x7fdf5a618611 - std::sys_common::backtrace::__rust_begin_short_backtrace::h3d5db7946c19f316
  25:     0x7fdf5a59618e - core::ops::function::FnOnce::call_once{{vtable.shim}}::he1a30fa4d30a2178
  26:     0x7fdf59d3efda - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h588ce842808b3fd0
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/alloc/src/boxed.rs:1042
  27:     0x7fdf59d3efda - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h46bc655f05471a92
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/alloc/src/boxed.rs:1042
  28:     0x7fdf59d3efda - std::sys::unix::thread::Thread::new::thread_start::hb4b79d379b730058
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys/unix/thread.rs:87
  29:     0x7fdf59c3b3e9 - start_thread
  30:     0x7fdf59b58293 - __GI___clone
  31:                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 1.49.0-nightly (98edd1fbf 2020-10-06) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=2

query stack during panic:
end of query stack

[matthiaskrgr]

oops, dupe of #73021