ICE: `thin_box`: ` RawPtr operands CValue(ByVal(v3)...`

[matthiaskrgr]

auto-reduced (treereduce-rust):

#![feature(thin_box)]

use std::boxed::ThinBox;
use std::error::Error;

use std::fmt;

fn main() {
    let expected = "Foo error!";
    let a: ThinBox<dyn Error> = ThinBox::new_unsize(Foo(expected));
}

#[derive(Debug)]

struct Foo(&'static str);

impl fmt::Display for Foo {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.0)
    }
}

impl Error for Foo {}

original:

#![feature(thin_box)]
// run-pass
use std::boxed::ThinBox;
use std::error::Error;
use std::ops::Deref;
use std::fmt;

fn main() {
    let expected = "Foo error!";
    let a: ThinBox<dyn Error> = ThinBox::new_unsize(Foo(expected));
    let a = a.deref();
    let msg = a.to_string();
    assert_eq!(expected, msg);
}

#[derive(Debug)]
#[repr(align(1024))]
struct Foo(&'static str);

impl fmt::Display for Foo {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self.0)
    }
}

impl Error for Foo {}

Version information

rustc 1.79.0-nightly (290d79241 2024-04-22)
binary: rustc
commit-hash: 290d792411566c94273e5d1a980a1ab91f1d950b
commit-date: 2024-04-22
host: x86_64-unknown-linux-gnu
release: 1.79.0-nightly
LLVM version: 18.1.4

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zcodegen-backend=cranelift

Program output

warning: unused variable: `a`
  --> /tmp/icemaker_global_tempdir.gikjMqxOJjk8/rustc_testrunner_tmpdir_reporting.WOGOOImz49M8/mvce.rs:10:9
   |
10 |     let a: ThinBox<dyn Error> = ThinBox::new_unsize(Foo(expected));
   |         ^ help: if this is intentional, prefix it with an underscore: `_a`
   |
   = note: `#[warn(unused_variables)]` on by default

error: internal compiler error: src/value_and_place.rs:109:18: RawPtr operands CValue(ByVal(v3), TyAndLayout { ty: *mut (), layout: Layout { size: Size(8 bytes), align: AbiAndPrefAlign { abi: Align(8 bytes), pref: Align(8 bytes) }, abi: Scalar(Initialized { value: Pointer(AddressSpace(0)), valid_range: 0..=18446744073709551615 }), fields: Primitive, largest_niche: None, variants: Single { index: 0 }, max_repr_align: None, unadjusted_abi_align: Align(8 bytes) } }) CValue(ByRef(Pointer { base: Stack(ss1), offset: Offset32(0) }, None), TyAndLayout { ty: DynMetadata<dyn std::error::Error>, layout: Layout { size: Size(8 bytes), align: AbiAndPrefAlign { abi: Align(8 bytes), pref: Align(8 bytes) }, abi: Scalar(Initialized { value: Pointer(AddressSpace(0)), valid_range: 1..=18446744073709551615 }), fields: Arbitrary { offsets: [Size(0 bytes), Size(8 bytes)], memory_index: [0, 1] }, largest_niche: Some(Niche { offset: Size(0 bytes), value: Pointer(AddressSpace(0)), valid_range: 1..=18446744073709551615 }), variants: Single { index: 0 }, max_repr_align: None, unadjusted_abi_align: Align(8 bytes) } })

thread 'rustc' panicked at src/value_and_place.rs:109:18:
Box<dyn Any>
stack backtrace:
   0:     0x7a9b144ac935 - std::backtrace_rs::backtrace::libunwind::trace::h26e1fa40e8cb8736
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/../../backtrace/src/backtrace/libunwind.rs:105:5
   1:     0x7a9b144ac935 - std::backtrace_rs::backtrace::trace_unsynchronized::h859af531c2f619a1
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7a9b144ac935 - std::sys_common::backtrace::_print_fmt::h770ada6f33df9a23
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7a9b144ac935 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h1202620471ff2013
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7a9b144fba6b - core::fmt::rt::Argument::fmt::h1d7f69a8f0bb037c
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/core/src/fmt/rt.rs:165:63
   5:     0x7a9b144fba6b - core::fmt::write::h2cfd50c1c61a678b
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/core/src/fmt/mod.rs:1157:21
   6:     0x7a9b144a14bf - std::io::Write::write_fmt::h68244818dfe9446a
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/io/mod.rs:1832:15
   7:     0x7a9b144ac70e - std::sys_common::backtrace::_print::hb0df927864ffa3c4
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7a9b144ac70e - std::sys_common::backtrace::print::hb29ea7496634044b
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7a9b144af079 - std::panicking::default_hook::{{closure}}::hcfcc8ff96a30a9c7
  10:     0x7a9b144aedbd - std::panicking::default_hook::h8bb790ee0d607409
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/panicking.rs:298:9
  11:     0x7a9b10e3227c - std[37c8ccdab8a3c0d8]::panicking::update_hook::<alloc[34ed19a5ff888b12]::boxed::Box<rustc_driver_impl[480b09937bfb0708]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7a9b144af776 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h11842aeeeb09579f
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/alloc/src/boxed.rs:2036:9
  13:     0x7a9b144af776 - std::panicking::rust_panic_with_hook::h2039ccc53629d416
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/panicking.rs:799:13
  14:     0x7a9b10e62584 - std[37c8ccdab8a3c0d8]::panicking::begin_panic::<rustc_errors[6444c462ca5918aa]::ExplicitBug>::{closure#0}
  15:     0x7a9b10e5ef36 - std[37c8ccdab8a3c0d8]::sys_common::backtrace::__rust_end_short_backtrace::<std[37c8ccdab8a3c0d8]::panicking::begin_panic<rustc_errors[6444c462ca5918aa]::ExplicitBug>::{closure#0}, !>
  16:     0x7a9b10e5a506 - std[37c8ccdab8a3c0d8]::panicking::begin_panic::<rustc_errors[6444c462ca5918aa]::ExplicitBug>
  17:     0x7a9b10e6b801 - <rustc_errors[6444c462ca5918aa]::diagnostic::BugAbort as rustc_errors[6444c462ca5918aa]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  18:     0x7a9b1131155c - rustc_middle[d30f97e255128713]::util::bug::opt_span_bug_fmt::<rustc_span[128fa906eb8a1c67]::span_encoding::Span>::{closure#0}
  19:     0x7a9b112f982a - rustc_middle[d30f97e255128713]::ty::context::tls::with_opt::<rustc_middle[d30f97e255128713]::util::bug::opt_span_bug_fmt<rustc_span[128fa906eb8a1c67]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  20:     0x7a9b112f96cb - rustc_middle[d30f97e255128713]::ty::context::tls::with_context_opt::<rustc_middle[d30f97e255128713]::ty::context::tls::with_opt<rustc_middle[d30f97e255128713]::util::bug::opt_span_bug_fmt<rustc_span[128fa906eb8a1c67]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  21:     0x7a9b0f68fe70 - rustc_middle[d30f97e255128713]::util::bug::bug_fmt
  22:     0x7a9b03e14bc9 - rustc_codegen_cranelift[f872669b1689024d]::base::codegen_fn_body
  23:     0x7a9b03e2a1bd - rustc_codegen_cranelift[f872669b1689024d]::driver::aot::module_codegen::{closure#0}
  24:     0x7a9b03e26477 - rustc_codegen_cranelift[f872669b1689024d]::driver::aot::module_codegen
  25:     0x7a9b03e33779 - rustc_codegen_cranelift[f872669b1689024d]::driver::aot::run_aot
  26:     0x7a9b03e60f21 - <rustc_codegen_cranelift[f872669b1689024d]::CraneliftCodegenBackend as rustc_codegen_ssa[db212267bf182275]::traits::backend::CodegenBackend>::codegen_crate
  27:     0x7a9b130a945d - rustc_interface[ffee9ea60ef965c3]::passes::start_codegen
  28:     0x7a9b130a8ad8 - <rustc_interface[ffee9ea60ef965c3]::queries::Queries>::codegen_and_build_linker
  29:     0x7a9b12dea7f6 - rustc_interface[ffee9ea60ef965c3]::interface::run_compiler::<core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>, rustc_driver_impl[480b09937bfb0708]::run_compiler::{closure#0}>::{closure#1}
  30:     0x7a9b12dd8627 - std[37c8ccdab8a3c0d8]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[ffee9ea60ef965c3]::util::run_in_thread_with_globals<rustc_interface[ffee9ea60ef965c3]::util::run_in_thread_pool_with_globals<rustc_interface[ffee9ea60ef965c3]::interface::run_compiler<core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>, rustc_driver_impl[480b09937bfb0708]::run_compiler::{closure#0}>::{closure#1}, core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>>::{closure#0}, core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>>
  31:     0x7a9b12dd83ea - <<std[37c8ccdab8a3c0d8]::thread::Builder>::spawn_unchecked_<rustc_interface[ffee9ea60ef965c3]::util::run_in_thread_with_globals<rustc_interface[ffee9ea60ef965c3]::util::run_in_thread_pool_with_globals<rustc_interface[ffee9ea60ef965c3]::interface::run_compiler<core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>, rustc_driver_impl[480b09937bfb0708]::run_compiler::{closure#0}>::{closure#1}, core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>>::{closure#0}, core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d851a872a27282f9]::result::Result<(), rustc_span[128fa906eb8a1c67]::ErrorGuaranteed>>::{closure#2} as core[d851a872a27282f9]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  32:     0x7a9b144b960b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h8fcfbedcc7bc1020
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/alloc/src/boxed.rs:2022:9
  33:     0x7a9b144b960b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hb725f441e1474916
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/alloc/src/boxed.rs:2022:9
  34:     0x7a9b144b960b - std::sys::pal::unix::thread::Thread::new::thread_start::h34c8a550ac2bc24c
                               at /rustc/290d792411566c94273e5d1a980a1ab91f1d950b/library/std/src/sys/pal/unix/thread.rs:108:17
  35:     0x7a9b0dca955a - <unknown>
  36:     0x7a9b0dd26a3c - <unknown>
  37:                0x0 - <unknown>

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: please make sure that you have updated to the latest nightly

note: rustc 1.79.0-nightly (290d79241 2024-04-22) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z codegen-backend=cranelift -Z dump-mir-dir=dir

query stack during panic:
end of query stack
error: aborting due to 1 previous error; 1 warning emitted

@rustbot label +F-thin_box

[rustbot]

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[bjorn3]

rust-lang/rust#123840 incorrectly assumed that scalar CValue's are always represented as CValueInner::ByVal while they can also be represented as CValueInner::ByRef. Unlike cg_ssa, cg_clif doesn't eagerly convert to the "canonical" form. Should be fixed in d0c5141.

[bjorn3]

Will sync the fix to the rust repo after the next cranelift update is done later today.

[bjorn3]

Fixed with the latest sync.