ice with -Zmir-opt-level=2 issue-50865-private-impl-trait/auxiliary/lib.rs

[matthiaskrgr]

Code

./src/test/ui/issues/issue-50865-private-impl-trait/auxiliary/lib.rs

#![crate_type = "lib"]

pub fn bar<P>( // Error won't happen if "bar" is not generic
    _baz: P,
) {
    hide_foo()();
}

fn hide_foo() -> impl Fn() { // Error won't happen if "iterate" hasn't impl Trait or has generics
    foo
}

fn foo() { // Error won't happen if "foo" isn't used in "iterate" or has generics
}

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(<impl std::ops::Fn<()> as std::ops::Fn<()>>)` 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(<impl std::ops::Fn<()> as std::ops::Fn<()>>)` 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:     0x7f0f02a6f0b0 - std::backtrace_rs::backtrace::libunwind::trace::h622bab51c72c4e69
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/../../backtrace/src/backtrace/libunwind.rs:96
   1:     0x7f0f02a6f0b0 - std::backtrace_rs::backtrace::trace_unsynchronized::h7e820b882ebd41ee
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/../../backtrace/src/backtrace/mod.rs:66
   2:     0x7f0f02a6f0b0 - std::sys_common::backtrace::_print_fmt::h64d46258114db92f
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:79
   3:     0x7f0f02a6f0b0 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h47111d0c1b5f0da5
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:58
   4:     0x7f0f02ade07c - core::fmt::write::h1857a60b204f1b6a
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/core/src/fmt/mod.rs:1080
   5:     0x7f0f02a61052 - std::io::Write::write_fmt::h4604516fed3e5731
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/io/mod.rs:1516
   6:     0x7f0f02a73e7d - std::sys_common::backtrace::_print::h785e7a78d5ef272c
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:61
   7:     0x7f0f02a73e7d - std::sys_common::backtrace::print::h108047ac5c4555d5
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:48
   8:     0x7f0f02a73e7d - std::panicking::default_hook::{{closure}}::h1d0c271f0d087ebf
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:208
   9:     0x7f0f02a73b28 - std::panicking::default_hook::h692753e26f11b7b7
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:227
  10:     0x7f0f033013e8 - rustc_driver::report_ice::h767ab601e5f63209
  11:     0x7f0f02a746c6 - std::panicking::rust_panic_with_hook::h74ddc20305301cd9
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:581
  12:     0x7f0f02a74249 - std::panicking::begin_panic_handler::{{closure}}::h1a9ca6427ceee1d0
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:484
  13:     0x7f0f02a6f54c - std::sys_common::backtrace::__rust_end_short_backtrace::h97e27b7ab754adde
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys_common/backtrace.rs:153
  14:     0x7f0f02a74209 - rust_begin_unwind
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:483
  15:     0x7f0f02a741bb - std::panicking::begin_panic_fmt::h45d0f154d1dd3395
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/panicking.rs:437
  16:     0x7f0f0631d281 - rustc_errors::HandlerInner::flush_delayed::h4e44ea29efc5a508
  17:     0x7f0f06319be1 - <rustc_errors::HandlerInner as core::ops::drop::Drop>::drop::hc2218eb325dc8425
  18:     0x7f0f0334ed76 - core::ptr::drop_in_place::he652386dc31d9e30
  19:     0x7f0f03350bc6 - <alloc::rc::Rc<T> as core::ops::drop::Drop>::drop::h60c7e2432b201062
  20:     0x7f0f0332a6fd - core::ptr::drop_in_place::h2f4d4236293b18c7
  21:     0x7f0f03324dea - rustc_span::with_source_map::h23e56868796f6dc3
  22:     0x7f0f03359ed2 - rustc_interface::interface::create_compiler_and_run::h9a8debbb19483b80
  23:     0x7f0f03338d0a - scoped_tls::ScopedKey<T>::set::hacc47b1cdb25a215
  24:     0x7f0f0335c611 - std::sys_common::backtrace::__rust_begin_short_backtrace::h3d5db7946c19f316
  25:     0x7f0f032da18e - core::ops::function::FnOnce::call_once{{vtable.shim}}::he1a30fa4d30a2178
  26:     0x7f0f02a82fda - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h588ce842808b3fd0
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/alloc/src/boxed.rs:1042
  27:     0x7f0f02a82fda - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h46bc655f05471a92
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/alloc/src/boxed.rs:1042
  28:     0x7f0f02a82fda - std::sys::unix::thread::Thread::new::thread_start::hb4b79d379b730058
                               at /rustc/98edd1fbf8a68977a2a7c1312eb1ebff80515a92/library/std/src/sys/unix/thread.rs:87
  29:     0x7f0f0297f3e9 - start_thread
  30:     0x7f0f0289c293 - __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

[JohnTitor]

Seems it regressed in #73905, cc @matthewjasper

[tedhorst]

This occurs in regex_syntax as well.

[matthewjasper]

I think that this is a missing normalize call here:

rust/compiler/rustc_mir/src/transform/inline.rs

Line 204 in 8cc82ee

let instance = Instance::resolve(self.tcx, self.param_env, callee_def_id, substs)

[tmiasko]

#77306?

[JohnTitor]

Yeah, just checked and it fixes the issue, cc @lcnr

[matthewjasper]

#77306 has merged now