ICE: primitive read not possible for type: AlignedUsize

[matthiaskrgr]

Code

src/test/ui/dyn-star/align.rs

//[normal] check-pass

#![feature(dyn_star)]
//~^ WARN the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes

use std::fmt::Debug;

#[cfg_attr(over_aligned,      repr(C, align(1024)))]
#[cfg_attr(not(over_aligned), repr(C))]
#[derive(Debug)]
struct AlignedUsize(usize);

fn main() {
    let x = AlignedUsize(12) as dyn* Debug;
    //[over_aligned]~^ ERROR `AlignedUsize` needs to be a pointer-sized type
}

Meta

rustc --version --verbose:

<version>

Error output

warning: the feature `dyn_star` is incomplete and may not be safe to use and/or cause compiler crashes
 --> src/test/ui/dyn-star/align.rs:4:12
  |
4 | #![feature(dyn_star)]
  |            ^^^^^^^^
  |
  = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
  = note: `#[warn(incomplete_features)]` on by default

warning: unused variable: `x`
  --> src/test/ui/dyn-star/align.rs:15:9
   |
15 |     let x = AlignedUsize(12) as dyn* Debug;
   |         ^ help: if this is intentional, prefix it with an underscore: `_x`
   |
   = note: `#[warn(unused_variables)]` on by default

Backtrace

error: internal compiler error: /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/compiler/rustc_const_eval/src/interpret/operand.rs:391:13: primitive read not possible for type: AlignedUsize
  --> src/test/ui/dyn-star/align.rs:15:13
   |
15 |     let x = AlignedUsize(12) as dyn* Debug;
   |             ^^^^^^^^^^^^^^^^

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/compiler/rustc_errors/src/lib.rs:969:33
stack backtrace:
   0:     0x7fb1de566a50 - std::backtrace_rs::backtrace::libunwind::trace::hc67583789182810a
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7fb1de566a50 - std::backtrace_rs::backtrace::trace_unsynchronized::h1938dfa1aa97f8ae
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fb1de566a50 - std::sys_common::backtrace::_print_fmt::hc27f3d4fb7d08e50
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7fb1de566a50 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h0efab7bfe941d4d0
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fb1da5c863e - core::fmt::write::h816cc3b1bcaa0f63
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/core/src/fmt/mod.rs:1208:17
   5:     0x7fb1de55ab25 - std::io::Write::write_fmt::h33dba8a681e64ab5
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/io/mod.rs:1682:15
   6:     0x7fb1de566815 - std::sys_common::backtrace::_print::ha3a4aa724c6dd991
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7fb1de566815 - std::sys_common::backtrace::print::h871c005525ccf4a5
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7fb1de568b2f - std::panicking::default_hook::{{closure}}::h424788f485e3b8e1
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/panicking.rs:267:22
   9:     0x7fb1de56886a - std::panicking::default_hook::ha4cff4743b1eccf9
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/panicking.rs:286:9
  10:     0x7fb1dd7c53c4 - <rustc_driver[31383bd51e4ce3bf]::DEFAULT_HOOK::{closure#0}::{closure#0} as core[521a141dd0e2ec56]::ops::function::FnOnce<(&core[521a141dd0e2ec56]::panic::panic_info::PanicInfo,)>>::call_once::{shim:vtable#0}
  11:     0x7fb1de56931d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hafd0e2079dea2b50
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/alloc/src/boxed.rs:2032:9
  12:     0x7fb1de56931d - std::panicking::rust_panic_with_hook::hc5412f99bf75d7f4
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/panicking.rs:692:13
  13:     0x7fb1dde39f11 - std[cb58addc38ea5d7f]::panicking::begin_panic::<rustc_errors[268b7194fd18b781]::ExplicitBug>::{closure#0}
  14:     0x7fb1dde38de6 - std[cb58addc38ea5d7f]::sys_common::backtrace::__rust_end_short_backtrace::<std[cb58addc38ea5d7f]::panicking::begin_panic<rustc_errors[268b7194fd18b781]::ExplicitBug>::{closure#0}, !>
  15:     0x7fb1ddd9d0c6 - std[cb58addc38ea5d7f]::panicking::begin_panic::<rustc_errors[268b7194fd18b781]::ExplicitBug>
  16:     0x7fb1dde38976 - std[cb58addc38ea5d7f]::panic::panic_any::<rustc_errors[268b7194fd18b781]::ExplicitBug>
  17:     0x7fb1dde33cf0 - <rustc_errors[268b7194fd18b781]::HandlerInner>::span_bug::<rustc_span[4526806d7c1f36b2]::span_encoding::Span, &alloc[3463f07d9a1225bb]::string::String>
  18:     0x7fb1dde31a77 - <rustc_errors[268b7194fd18b781]::Handler>::span_bug::<rustc_span[4526806d7c1f36b2]::span_encoding::Span, &alloc[3463f07d9a1225bb]::string::String>
  19:     0x7fb1dddd9908 - rustc_middle[3045a148646aecd0]::ty::context::tls::with_context_opt::<rustc_middle[3045a148646aecd0]::ty::context::tls::with_opt<rustc_middle[3045a148646aecd0]::util::bug::opt_span_bug_fmt<rustc_span[4526806d7c1f36b2]::span_encoding::Span>::{closure#0}, ()>::{closure#0}, ()>
  20:     0x7fb1dddd97a6 - rustc_middle[3045a148646aecd0]::util::bug::opt_span_bug_fmt::<rustc_span[4526806d7c1f36b2]::span_encoding::Span>
  21:     0x7fb1dc904a24 - rustc_middle[3045a148646aecd0]::util::bug::span_bug_fmt::<rustc_span[4526806d7c1f36b2]::span_encoding::Span>
  22:     0x7fb1dc8daa99 - <rustc_const_eval[51ebc319a3c288fc]::interpret::eval_context::InterpCx<rustc_mir_transform[1c913e9f9ba10abc]::const_prop::ConstPropMachine>>::eval_rvalue_into_place
  23:     0x7fb1dbf8d4b7 - <rustc_mir_transform[1c913e9f9ba10abc]::const_prop_lint::ConstPropagator as rustc_middle[3045a148646aecd0]::mir::visit::Visitor>::visit_body
  24:     0x7fb1dbf83d2a - <rustc_mir_transform[1c913e9f9ba10abc]::const_prop_lint::ConstProp as rustc_mir_transform[1c913e9f9ba10abc]::pass_manager::MirLint>::run_lint
  25:     0x7fb1db9f53a3 - rustc_mir_transform[1c913e9f9ba10abc]::run_analysis_to_runtime_passes
  26:     0x7fb1db9f3e54 - rustc_mir_transform[1c913e9f9ba10abc]::mir_drops_elaborated_and_const_checked
  27:     0x7fb1dc63f8a9 - rustc_query_system[fc3aa43ff1e3f72f]::query::plumbing::try_execute_query::<rustc_query_impl[a10e1632aef79c39]::plumbing::QueryCtxt, rustc_query_system[fc3aa43ff1e3f72f]::query::caches::DefaultCache<rustc_middle[3045a148646aecd0]::ty::WithOptConstParam<rustc_span[4526806d7c1f36b2]::def_id::LocalDefId>, &rustc_data_structures[9e70e8f4e8382b0d]::steal::Steal<rustc_middle[3045a148646aecd0]::mir::Body>>>
  28:     0x7fb1dc0f8a13 - rustc_mir_transform[1c913e9f9ba10abc]::optimized_mir
  29:     0x7fb1dc0f4553 - rustc_query_system[fc3aa43ff1e3f72f]::query::plumbing::try_execute_query::<rustc_query_impl[a10e1632aef79c39]::plumbing::QueryCtxt, rustc_query_system[fc3aa43ff1e3f72f]::query::caches::DefaultCache<rustc_span[4526806d7c1f36b2]::def_id::DefId, &rustc_middle[3045a148646aecd0]::mir::Body>>
  30:     0x7fb1dc3281d3 - <rustc_middle[3045a148646aecd0]::ty::context::TyCtxt>::instance_mir
  31:     0x7fb1dc31937b - rustc_monomorphize[542e48549e1eab61]::collector::collect_neighbours
  32:     0x7fb1dc316773 - rustc_monomorphize[542e48549e1eab61]::collector::collect_items_rec
  33:     0x7fb1dcc34e6c - <rustc_session[883587d705af57a8]::session::Session>::time::<(), rustc_monomorphize[542e48549e1eab61]::collector::collect_crate_mono_items::{closure#1}>
  34:     0x7fb1dcc34969 - rustc_monomorphize[542e48549e1eab61]::collector::collect_crate_mono_items
  35:     0x7fb1dcc33ca3 - rustc_monomorphize[542e48549e1eab61]::partitioning::collect_and_partition_mono_items
  36:     0x7fb1dcf83870 - rustc_query_system[fc3aa43ff1e3f72f]::query::plumbing::try_execute_query::<rustc_query_impl[a10e1632aef79c39]::plumbing::QueryCtxt, rustc_query_system[fc3aa43ff1e3f72f]::query::caches::DefaultCache<(), (&std[cb58addc38ea5d7f]::collections::hash::set::HashSet<rustc_span[4526806d7c1f36b2]::def_id::DefId, core[521a141dd0e2ec56]::hash::BuildHasherDefault<rustc_hash[fdce590595b7296d]::FxHasher>>, &[rustc_middle[3045a148646aecd0]::mir::mono::CodegenUnit])>>
  37:     0x7fb1dcf8353b - rustc_query_system[fc3aa43ff1e3f72f]::query::plumbing::get_query::<rustc_query_impl[a10e1632aef79c39]::queries::collect_and_partition_mono_items, rustc_query_impl[a10e1632aef79c39]::plumbing::QueryCtxt>
  38:     0x7fb1dcf8347e - <rustc_query_impl[a10e1632aef79c39]::Queries as rustc_middle[3045a148646aecd0]::ty::query::QueryEngine>::collect_and_partition_mono_items
  39:     0x7fb1dceb5e4b - rustc_codegen_ssa[62e3ce45a5d58d5f]::base::codegen_crate::<rustc_codegen_llvm[8cc7a0b1f5c8b714]::LlvmCodegenBackend>
  40:     0x7fb1dceb5c09 - <rustc_codegen_llvm[8cc7a0b1f5c8b714]::LlvmCodegenBackend as rustc_codegen_ssa[62e3ce45a5d58d5f]::traits::backend::CodegenBackend>::codegen_crate
  41:     0x7fb1dca7fc21 - <rustc_session[883587d705af57a8]::session::Session>::time::<alloc[3463f07d9a1225bb]::boxed::Box<dyn core[521a141dd0e2ec56]::any::Any>, rustc_interface[24fa5d2953a1af2]::passes::start_codegen::{closure#0}>
  42:     0x7fb1dca7f714 - rustc_interface[24fa5d2953a1af2]::passes::start_codegen
  43:     0x7fb1dca79ac0 - <rustc_interface[24fa5d2953a1af2]::passes::QueryContext>::enter::<<rustc_interface[24fa5d2953a1af2]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[521a141dd0e2ec56]::result::Result<alloc[3463f07d9a1225bb]::boxed::Box<dyn core[521a141dd0e2ec56]::any::Any>, rustc_errors[268b7194fd18b781]::ErrorGuaranteed>>
  44:     0x7fb1dca76ec3 - <rustc_interface[24fa5d2953a1af2]::queries::Queries>::ongoing_codegen
  45:     0x7fb1dca75fd2 - <rustc_interface[24fa5d2953a1af2]::interface::Compiler>::enter::<rustc_driver[31383bd51e4ce3bf]::run_compiler::{closure#1}::{closure#2}, core[521a141dd0e2ec56]::result::Result<core[521a141dd0e2ec56]::option::Option<rustc_interface[24fa5d2953a1af2]::queries::Linker>, rustc_errors[268b7194fd18b781]::ErrorGuaranteed>>
  46:     0x7fb1dca70fd2 - rustc_span[4526806d7c1f36b2]::with_source_map::<core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>, rustc_interface[24fa5d2953a1af2]::interface::run_compiler<core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>, rustc_driver[31383bd51e4ce3bf]::run_compiler::{closure#1}>::{closure#0}::{closure#1}>
  47:     0x7fb1dca70ac9 - <scoped_tls[cdc8eb0d557683b4]::ScopedKey<rustc_span[4526806d7c1f36b2]::SessionGlobals>>::set::<rustc_interface[24fa5d2953a1af2]::interface::run_compiler<core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>, rustc_driver[31383bd51e4ce3bf]::run_compiler::{closure#1}>::{closure#0}, core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>>
  48:     0x7fb1dca700d8 - std[cb58addc38ea5d7f]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[24fa5d2953a1af2]::util::run_in_thread_pool_with_globals<rustc_interface[24fa5d2953a1af2]::interface::run_compiler<core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>, rustc_driver[31383bd51e4ce3bf]::run_compiler::{closure#1}>::{closure#0}, core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>>
  49:     0x7fb1dca6fdfc - <<std[cb58addc38ea5d7f]::thread::Builder>::spawn_unchecked_<rustc_interface[24fa5d2953a1af2]::util::run_in_thread_pool_with_globals<rustc_interface[24fa5d2953a1af2]::interface::run_compiler<core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>, rustc_driver[31383bd51e4ce3bf]::run_compiler::{closure#1}>::{closure#0}, core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[521a141dd0e2ec56]::result::Result<(), rustc_errors[268b7194fd18b781]::ErrorGuaranteed>>::{closure#1} as core[521a141dd0e2ec56]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  50:     0x7fb1de5705d3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::he14419f019efa077
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/alloc/src/boxed.rs:2000:9
  51:     0x7fb1de5705d3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hc04646210560e02e
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/alloc/src/boxed.rs:2000:9
  52:     0x7fb1de5705d3 - std::sys::unix::thread::Thread::new::thread_start::h9810da48ba5dc059
                               at /rustc/c5d82ed7a4ad94a538bb87e5016e7d5ce0bd434b/library/std/src/sys/unix/thread.rs:108:17
  53:     0x7fb1da3078fd - <unknown>
  54:     0x7fb1da389a60 - <unknown>
  55:                0x0 - <unknown>

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 1.67.0-nightly (c5d82ed7a 2022-11-19) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [mir_drops_elaborated_and_const_checked] elaborating drops for `main`
#1 [optimized_mir] optimizing MIR for `main`
#2 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack
error: aborting due to previous error; 2 warnings emitted

[langston-barrett]

Were there special flags needed to get this to ICE? I can't reproduce on

rustc 1.70.0-nightly (511364e78 2023-03-16)
binary: rustc
commit-hash: 511364e7874dba9649a264100407e4bffe7b5425
commit-date: 2023-03-16
host: x86_64-unknown-linux-gnu
release: 1.70.0-nightly
LLVM version: 15.0.7

[compiler-errors]

You need to do a full build, not just a check, so make sure it gets all the way to codegen?

[compiler-errors]

Oh, nvm, you need to compile this with --cfg over_aligned.

[JohnTitor]

MCVE:

#![feature(dyn_star)]
#![allow(incomplete_features)]

use std::fmt::Debug;

#[repr(C)]
#[derive(Debug)]
struct AlignedUsize(usize);

fn main() {
    let _x = AlignedUsize(12) as dyn* Debug;
}

1.70.0-nightly (696aaad 2023-04-09) now emits an error instead of ICE:

error[E0277]: `AlignedUsize` needs to have the same ABI as a pointer
  --> src/main.rs:11:14
   |
11 |     let _x = AlignedUsize(12) as dyn* Debug;
   |              ^^^^^^^^^^^^^^^^ `AlignedUsize` needs to be a pointer-like type
   |
   = help: the trait `PointerLike` is not implemented for `AlignedUsize`

For more information about this error, try `rustc --explain E0277`.

Marking as E-needs-test