ice: miri: `aggregate_field_path_elem: got non-aggregate type CoroutineClosure`

[matthiaskrgr]

Code

// edition:2021
// skip-filecheck
// EMIT_MIR_FOR_EACH_PANIC_STRATEGY

#![feature(async_closure, noop_waker, async_fn_traits)]

use std::future::Future;
use std::ops::{AsyncFnMut, AsyncFnOnce};
use std::pin::pin;
use std::task::*;

pub fn block_on<T>(fut: impl Future<Output = T>) -> T {
    let mut fut = pin!(fut);
    let ctx = &mut Context::from_waker(Waker::noop());

    loop {
        match fut.as_mut().poll(ctx) {
            Poll::Pending => {}
            Poll::Ready(t) => break t,
        }
    }
}

async fn call_mut(f: &mut impl AsyncFnMut(i32)) {
    f(0).await;
}

async fn call_once(f: impl AsyncFnOnce(i32)) {
    f(1).await;
}

// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.mir
// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_mut.0.mir
// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_mut.0.mir
// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.coroutine_by_move.0.mir
pub fn main() {
    block_on(async {
        let b = 2i32;
        let mut async_closure = async move |a: i32| {
            let a = &a;
            let b = &b;
        };
        call_mut(&mut async_closure).await;
        call_once(async_closure).await;
    });
}

Meta

rustc --version --verbose:

miri 0.1.0 (6cc4843 2024-02-10)

Error output

<output>

Backtrace

Preparing a sysroot for Miri (target: x86_64-unknown-linux-gnu)... done
WARNING: Ignoring `RUSTC_WRAPPER` environment variable, Miri does not support wrapping.
   Compiling mirice v0.1.0 (/tmp/im/mirice)
    Finished dev [unoptimized + debuginfo] target(s) in 0.07s
     Running `/home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo-miri runner target/miri/x86_64-unknown-linux-gnu/debug/mirice`
warning: unused variable: `a`
  --> src/main.rs:40:17
   |
40 |             let a = &a;
   |                 ^ help: if this is intentional, prefix it with an underscore: `_a`
   |
   = note: `#[warn(unused_variables)]` on by default

warning: unused variable: `b`
  --> src/main.rs:41:17
   |
41 |             let b = &b;
   |                 ^ help: if this is intentional, prefix it with an underscore: `_b`

error: internal compiler error: /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/compiler/rustc_const_eval/src/interpret/validity.rs:292:18: aggregate_field_path_elem: got non-aggregate type CoroutineClosure(DefId(0:17 ~ mirice[9343]::main::{closure#0}::{closure#0}), [i8, Binder(extern "RustCall" fn(std::future::ResumeTy, (i32,)) -> ((), ()), []), (i32,), Binder(fn() -> (&ReBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon }) i32,), [Region(BrAnon)]), CoroutineWitness(DefId(0:18 ~ mirice[9343]::main::{closure#0}::{closure#0}::{closure#0}), [])])

thread 'rustc' panicked at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/compiler/rustc_errors/src/lib.rs:929:30:
Box<dyn Any>
stack backtrace:
   0:     0x7fb448a0b936 - std::backtrace_rs::backtrace::libunwind::trace::hce337a0fd0c5e1da
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7fb448a0b936 - std::backtrace_rs::backtrace::trace_unsynchronized::hbc9b4a5cec9b81eb
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fb448a0b936 - std::sys_common::backtrace::_print_fmt::habe453adcd959f3b
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7fb448a0b936 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h67bb2d10ecb8af10
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fb448a5e380 - core::fmt::rt::Argument::fmt::hd5debad710e176b4
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/core/src/fmt/rt.rs:142:9
   5:     0x7fb448a5e380 - core::fmt::write::h5987d5bee25e3bd6
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/core/src/fmt/mod.rs:1120:17
   6:     0x7fb4489ff0ef - std::io::Write::write_fmt::h0876e0f4bddb923c
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/io/mod.rs:1854:15
   7:     0x7fb448a0b714 - std::sys_common::backtrace::_print::h4ae69e83d64cbf46
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7fb448a0b714 - std::sys_common::backtrace::print::h1d97d5831d0262fb
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7fb448a0e4d7 - std::panicking::default_hook::{{closure}}::h39fabb1b3e65f47a
  10:     0x7fb448a0e239 - std::panicking::default_hook::h416520d6bb2cb53f
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/panicking.rs:292:9
  11:     0x7fb4457266dc - std[3acc11fb688f3d76]::panicking::update_hook::<alloc[408654ec2a1215fa]::boxed::Box<rustc_driver_impl[a7481a600b2f11a0]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7fb448a0ec26 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h2450ecbe2b1c1ea3
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/alloc/src/boxed.rs:2030:9
  13:     0x7fb448a0ec26 - std::panicking::rust_panic_with_hook::h99ef5cbc4b3b0ae4
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/panicking.rs:785:13
  14:     0x7fb445758034 - std[3acc11fb688f3d76]::panicking::begin_panic::<rustc_errors[1a010a4816a218fe]::ExplicitBug>::{closure#0}
  15:     0x7fb445754726 - std[3acc11fb688f3d76]::sys_common::backtrace::__rust_end_short_backtrace::<std[3acc11fb688f3d76]::panicking::begin_panic<rustc_errors[1a010a4816a218fe]::ExplicitBug>::{closure#0}, !>
  16:     0x7fb44574fe56 - std[3acc11fb688f3d76]::panicking::begin_panic::<rustc_errors[1a010a4816a218fe]::ExplicitBug>
  17:     0x7fb445763271 - <rustc_errors[1a010a4816a218fe]::diagnostic_builder::BugAbort as rustc_errors[1a010a4816a218fe]::diagnostic_builder::EmissionGuarantee>::emit_producing_guarantee
  18:     0x7fb445b1a16e - <rustc_errors[1a010a4816a218fe]::DiagCtxt>::bug::<alloc[408654ec2a1215fa]::string::String>
  19:     0x7fb445bb505b - rustc_middle[9f94bb95ba4eb693]::util::bug::opt_span_bug_fmt::<rustc_span[4a89bdba9678f8e0]::span_encoding::Span>::{closure#0}
  20:     0x7fb445b9c2ea - rustc_middle[9f94bb95ba4eb693]::ty::context::tls::with_opt::<rustc_middle[9f94bb95ba4eb693]::util::bug::opt_span_bug_fmt<rustc_span[4a89bdba9678f8e0]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7fb445b9c188 - rustc_middle[9f94bb95ba4eb693]::ty::context::tls::with_context_opt::<rustc_middle[9f94bb95ba4eb693]::ty::context::tls::with_opt<rustc_middle[9f94bb95ba4eb693]::util::bug::opt_span_bug_fmt<rustc_span[4a89bdba9678f8e0]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7fb443b8f9e0 - rustc_middle[9f94bb95ba4eb693]::util::bug::bug_fmt
  23:     0x5557bd9cd04a - <rustc_const_eval[12fc7f34b1bb2601]::interpret::validity::ValidityVisitor<miri[827b2b8b4315e2f2]::machine::MiriMachine> as rustc_const_eval[12fc7f34b1bb2601]::interpret::visitor::ValueVisitor<miri[827b2b8b4315e2f2]::machine::MiriMachine>>::visit_field
  24:     0x5557bd9ce2c8 - <rustc_const_eval[12fc7f34b1bb2601]::interpret::validity::ValidityVisitor<miri[827b2b8b4315e2f2]::machine::MiriMachine> as rustc_const_eval[12fc7f34b1bb2601]::interpret::visitor::ValueVisitor<miri[827b2b8b4315e2f2]::machine::MiriMachine>>::visit_value
  25:     0x5557bd9a998a - <rustc_const_eval[12fc7f34b1bb2601]::interpret::eval_context::InterpCx<miri[827b2b8b4315e2f2]::machine::MiriMachine>>::validate_operand_internal
  26:     0x5557bd99ce8f - <rustc_const_eval[12fc7f34b1bb2601]::interpret::eval_context::InterpCx<miri[827b2b8b4315e2f2]::machine::MiriMachine>>::eval_rvalue_into_place
  27:     0x5557bda18ff3 - <rustc_const_eval[12fc7f34b1bb2601]::interpret::eval_context::InterpCx<miri[827b2b8b4315e2f2]::machine::MiriMachine> as miri[827b2b8b4315e2f2]::concurrency::thread::EvalContextExt>::run_threads
  28:     0x5557bda2a514 - miri[827b2b8b4315e2f2]::eval::eval_entry
  29:     0x5557bd86c693 - <miri[93aa4a3be542fe23]::MiriCompilerCalls as rustc_driver_impl[a7481a600b2f11a0]::Callbacks>::after_analysis
  30:     0x7fb44773a5ba - rustc_interface[57a4cb1189ffa880]::interface::run_compiler::<core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>, rustc_driver_impl[a7481a600b2f11a0]::run_compiler::{closure#0}>::{closure#0}
  31:     0x7fb4477d2b46 - std[3acc11fb688f3d76]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[57a4cb1189ffa880]::util::run_in_thread_with_globals<rustc_interface[57a4cb1189ffa880]::util::run_in_thread_pool_with_globals<rustc_interface[57a4cb1189ffa880]::interface::run_compiler<core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>, rustc_driver_impl[a7481a600b2f11a0]::run_compiler::{closure#0}>::{closure#0}, core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>>::{closure#0}, core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>>
  32:     0x7fb4477d2973 - <<std[3acc11fb688f3d76]::thread::Builder>::spawn_unchecked_<rustc_interface[57a4cb1189ffa880]::util::run_in_thread_with_globals<rustc_interface[57a4cb1189ffa880]::util::run_in_thread_pool_with_globals<rustc_interface[57a4cb1189ffa880]::interface::run_compiler<core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>, rustc_driver_impl[a7481a600b2f11a0]::run_compiler::{closure#0}>::{closure#0}, core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>>::{closure#0}, core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[8df037f8ced6ea1f]::result::Result<(), rustc_span[4a89bdba9678f8e0]::ErrorGuaranteed>>::{closure#1} as core[8df037f8ced6ea1f]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  33:     0x7fb448a17eb5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h61e4d902e063b23d
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/alloc/src/boxed.rs:2016:9
  34:     0x7fb448a17eb5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hfa3eaf4f75275f59
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/alloc/src/boxed.rs:2016:9
  35:     0x7fb448a17eb5 - std::sys::pal::unix::thread::Thread::new::thread_start::hb901d27f412b0ecd
                               at /rustc/6cc4843512d613f51ec81aba689180c31b0b28b6/library/std/src/sys/pal/unix/thread.rs:108:17
  36:     0x7fb4427bd9eb - <unknown>
  37:     0x7fb4428417cc - <unknown>
  38:                0x0 - <unknown>

note: we would appreciate a bug report: https://github.com/rust-lang/miri/issues/new

note: please attach the file at `/tmp/im/mirice/rustc-ice-2024-02-11T21_09_07-2228199.txt` to your bug report

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C incremental=[REDACTED] -C target-cpu=native

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
end of query stack

Miri caused an ICE during evaluation. Here's the interpreter backtrace at the time of the panic:
note: the place in the program where the ICE was triggered
  --> src/main.rs:44:19
   |
44 |         call_once(async_closure).await;
   |                   ^^^^^^^^^^^^^
   |
   = note: inside closure at src/main.rs:44:19: 44:32
note: inside `block_on::<(), {async block@src/main.rs:37:14: 45:6}>`
  --> src/main.rs:17:15
   |
17 |         match fut.as_mut().poll(ctx) {
   |               ^^^^^^^^^^^^^^^^^^^^^^
note: inside `main`
  --> src/main.rs:37:5
   |
37 | /     block_on(async {
38 | |         let b = 2i32;
39 | |         let mut async_closure = async move |a: i32| {
40 | |             let a = &a;
...  |
44 | |         call_once(async_closure).await;
45 | |     });
   | |______^
   = note: inside `<fn() as std::ops::FnOnce<()>>::call_once - shim(fn())` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5: 250:71
   = note: inside `std::sys_common::backtrace::__rust_begin_short_backtrace::<fn(), ()>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/sys_common/backtrace.rs:155:18: 155:21
   = note: inside closure at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:166:18: 166:82
   = note: inside `std::ops::function::impls::<impl std::ops::FnOnce<()> for &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>::call_once` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ops/function.rs:284:13: 284:31
   = note: inside `std::panicking::r#try::do_call::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:554:40: 554:43
   = note: inside `std::panicking::r#try::<i32, &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:518:19: 518:81
   = note: inside `std::panic::catch_unwind::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:142:14: 142:33
   = note: inside closure at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:148:48: 148:73
   = note: inside `std::panicking::r#try::do_call::<{closure@std::rt::lang_start_internal::{closure#2}}, isize>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:554:40: 554:43
   = note: inside `std::panicking::r#try::<isize, {closure@std::rt::lang_start_internal::{closure#2}}>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:518:19: 518:81
   = note: inside `std::panic::catch_unwind::<{closure@std::rt::lang_start_internal::{closure#2}}, isize>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:142:14: 142:33
   = note: inside `std::rt::lang_start_internal` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:148:20: 148:98
   = note: inside `std::rt::lang_start::<()>` at /home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:165:17: 170:6

error: aborting due to 1 previous error; 2 warnings emitted

[matthiaskrgr]

bit smaller:

#![feature(async_closure, noop_waker, async_fn_traits)]

use std::future::Future;
use std::ops::AsyncFnOnce;
use std::pin::pin;
use std::task::*;

pub fn block_on<T>(fut: impl Future<Output = T>) -> T {
    let mut fut = pin!(fut);
    let ctx = &mut Context::from_waker(Waker::noop());

    loop {
        match fut.as_mut().poll(ctx) {
            Poll::Pending => {}
            Poll::Ready(t) => break t,
        }
    }
}

async fn call_once(f: impl AsyncFnOnce(i32)) {
    f(1).await;
}


pub fn main() {
    block_on(async {
        let b = 2i32;
        let mut async_closure = async move |_| {
            let b = &b;
        };
        call_once(async_closure).await;
    });
}

cc @rust-lang/miri

[RalfJung]

Yeah we have special support for Coroutines and Closures in this logic:

rust/compiler/rustc_const_eval/src/interpret/validity.rs

Lines 239 to 240 in 77f8c3c

	// coroutines and closures.
	ty::Closure(def_id, _) | ty::Coroutine(def_id, _) => {

And it seems now we have a new similar kind of unnamed ADT that needs similar support. @compiler-errors How similar is it to Coroutines and Closures, can it reuse the exact same logic? In particular, will closure_captures give a sensible result?

Maybe it'd make sense to group these in one TyKind to they can be treated together where appropriate?

[RalfJung]

Hm, why is there a function that says "closure or coroutine" that only checks for closures?

rust/compiler/rustc_middle/src/ty/util.rs

Lines 550 to 552 in c567edd

	pub fn is_closure_or_coroutine(self, def_id: DefId) -> bool {
	matches!(self.def_kind(def_id), DefKind::Closure)
	}

Or does DefKind::Closure also include coroutines? It doesn't have a doc comment that would say so. Does it include CoroutineClosure as well?

[matthiaskrgr]

shorter sample from tests/codegen/async-closure-debug.rs

#![feature(async_closure)]

fn async_closure_test(upvar: &str) -> impl async Fn() + '_ {
    async move || {
        let hello = String::from("hello");
        println!("{hello}, {upvar}");
    }
}

fn main() {
    let _async_closure = async_closure_test("world");
}

[RalfJung]

Yeah #120361 didn't add Miri tests so I am not surprised that it is broken.

[compiler-errors]

@RalfJung:

Maybe it'd make sense to group these in one TyKind to they can be treated together where appropriate?

They are extremely different (they have different substs, have different layouts, different traits are implemented for them), and it would be very confusing to group them into one TyKind.

Or does DefKind::Closure also include coroutines? It doesn't have a doc comment that would say so.

Yes, this was recently done by @bvanjoi and @petrochenkov, I believe. The reason behind this is that they are all expressed in the HIR (and earlier in the AST) as the same construct hir::ExprKind::Closure, and the DefCollector that assigns DefIds cannot not distinguish them.

Does it include CoroutineClosure as well?

Yes, it does. I can make that change to clarify the function behavior.

[RalfJung]

Yes, this was recently done by @bvanjoi and @petrochenkov, I believe. The reason behind this is that they are all expressed in the HIR (and earlier in the AST) as the same construct hir::ExprKind::Closure, and the DefCollector that assigns DefIds cannot not distinguish them.

Okay. Would be good to document this in the DefKind definition then, the current situation is quite confusing.