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Miri ICE/possible miscompilation with diverging function returning repr(transparent) wrapper with uninhabited ZST, transmuted to function pointer returning wrapped field. #135802

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zachs18 opened this issue Jan 21, 2025 · 1 comment
Open

Miri ICE/possible miscompilation with diverging function returning repr(transparent) wrapper with uninhabited ZST, transmuted to function pointer returning wrapped field. #135802

zachs18 opened this issue Jan 21, 2025 · 1 comment
Labels
A-ABI Area: Concerning the application binary interface (ABI) A-miri Area: The miri tool C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.

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@zachs18
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zachs18 commented Jan 21, 2025 •
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This code ICEs Miri, the normal compiler compiles this without complaint, but might be miscompiling it1, though a const version using -Zunleash-the-miri-inside-of-you does ICE the compiler.

Code

type Field = u8; // any non-1ZST probably
#[repr(transparent)]
struct Foo {
  _zst: std::convert::Infallible,
  _field: Field,
}
fn foo() -> Foo {
  panic!()
}
fn main() {
  let f: fn() -> Foo = foo;
  let f: fn() -> Field = unsafe { std::mem::transmute(f) };
  f();
}  
cargo +nightly miri run
modified version using `-Zunleash-the-miri-inside-of-you` that ICEs rustc 
type Field = u8; // any non-1ZST probably
#[repr(transparent)]
struct Foo {
  _zst: std::convert::Infallible,
  _field: Field,
}
const fn foo() -> Foo {
    panic!()
}
fn main() {
    const {
        let f: fn() -> Foo = foo;
        let f: fn() -> Field = unsafe { std::mem::transmute(f) };
        f();
    }
}
RUSTFLAGS="-Zunleash-the-miri-inside-of-you" cargo +nightly run

Backtrace:

thread 'rustc' panicked at compiler/rustc_const_eval/src/interpret/call.rs:253:13:
assertion failed: caller_abi.eq_abi(callee_abi)
stack backtrace:
   0:     0x7e3cb9b652a5 - std::backtrace::Backtrace::create::h8985a2f6ef2eb84f
   1:     0x7e3cb80e39f5 - std::backtrace::Backtrace::force_capture::h9a611efb2a942dc9
   2:     0x7e3cb725a4e0 - std[4faddc71fb6fa0e5]::panicking::update_hook::<alloc[c55780341d73682]::boxed::Box<rustc_driver_impl[80a9ca323d3e3890]::install_ice_hook::{closure#1}>>::{closure#0}
   3:     0x7e3cb80fc333 - std::panicking::rust_panic_with_hook::hf47d9e178e038701
   4:     0x7e3cb80fbff6 - std::panicking::begin_panic_handler::{{closure}}::hd9b9f2d3dd54e86c
   5:     0x7e3cb80f99e9 - std::sys::backtrace::__rust_end_short_backtrace::h342bb668fc58e319
   6:     0x7e3cb80fbced - rust_begin_unwind
   7:     0x7e3cb4da8db0 - core::panicking::panic_fmt::hb3cd74fdfc019257
   8:     0x7e3cb5897b9c - core::panicking::panic::h92e08174b9fe42d1
   9:     0x7e3cb92c11bb - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<rustc_const_eval[e3d2a21e14ef9d90]::const_eval::machine::CompileTimeMachine>>::init_stack_frame
  10:     0x7e3cb92bde11 - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<rustc_const_eval[e3d2a21e14ef9d90]::const_eval::machine::CompileTimeMachine>>::init_fn_call
  11:     0x7e3cb6314e8f - rustc_const_eval[e3d2a21e14ef9d90]::const_eval::eval_queries::eval_to_allocation_raw_provider
  12:     0x7e3cb9041f5c - rustc_query_impl[283282ac12660651]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[283282ac12660651]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 24usize]>>
  13:     0x7e3cb9041fb7 - <rustc_query_impl[283282ac12660651]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2} as core[b8d8efd06dd057cd]::ops::function::FnOnce<(rustc_middle[d099a8b084c78b18]::ty::context::TyCtxt, rustc_middle[d099a8b084c78b18]::ty::PseudoCanonicalInput<rustc_middle[d099a8b084c78b18]::mir::interpret::GlobalId>)>>::call_once
  14:     0x7e3cb90406be - rustc_query_system[57efd1c10fae1b2]::query::plumbing::try_execute_query::<rustc_query_impl[283282ac12660651]::DynamicConfig<rustc_query_system[57efd1c10fae1b2]::query::caches::DefaultCache<rustc_middle[d099a8b084c78b18]::ty::PseudoCanonicalInput<rustc_middle[d099a8b084c78b18]::mir::interpret::GlobalId>, rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[283282ac12660651]::plumbing::QueryCtxt, true>
  15:     0x7e3cb903fffd - rustc_query_impl[283282ac12660651]::query_impl::eval_to_allocation_raw::get_query_incr::__rust_end_short_backtrace
  16:     0x7e3cb904475f - rustc_const_eval[e3d2a21e14ef9d90]::const_eval::eval_queries::eval_to_const_value_raw_provider
  17:     0x7e3cb9044554 - rustc_query_impl[283282ac12660651]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[283282ac12660651]::query_impl::eval_to_const_value_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 24usize]>>
  18:     0x7e3cb904450d - <rustc_query_impl[283282ac12660651]::query_impl::eval_to_const_value_raw::dynamic_query::{closure#2} as core[b8d8efd06dd057cd]::ops::function::FnOnce<(rustc_middle[d099a8b084c78b18]::ty::context::TyCtxt, rustc_middle[d099a8b084c78b18]::ty::PseudoCanonicalInput<rustc_middle[d099a8b084c78b18]::mir::interpret::GlobalId>)>>::call_once
  19:     0x7e3cb903f2e6 - rustc_query_system[57efd1c10fae1b2]::query::plumbing::try_execute_query::<rustc_query_impl[283282ac12660651]::DynamicConfig<rustc_query_system[57efd1c10fae1b2]::query::caches::DefaultCache<rustc_middle[d099a8b084c78b18]::ty::PseudoCanonicalInput<rustc_middle[d099a8b084c78b18]::mir::interpret::GlobalId>, rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 24usize]>>, false, true, false>, rustc_query_impl[283282ac12660651]::plumbing::QueryCtxt, true>
  20:     0x7e3cb903ebc7 - rustc_query_impl[283282ac12660651]::query_impl::eval_to_const_value_raw::get_query_incr::__rust_end_short_backtrace
  21:     0x7e3cb95e110b - <rustc_middle[d099a8b084c78b18]::ty::context::TyCtxt>::const_eval_resolve
  22:     0x7e3cb5825b39 - <rustc_mir_transform[e7af90bdb15a3f20]::known_panics_lint::ConstPropagator as rustc_middle[d099a8b084c78b18]::mir::visit::Visitor>::visit_operand
  23:     0x7e3cb5829080 - <rustc_mir_transform[e7af90bdb15a3f20]::known_panics_lint::ConstPropagator as rustc_middle[d099a8b084c78b18]::mir::visit::Visitor>::visit_assign
  24:     0x7e3cb582799b - <rustc_mir_transform[e7af90bdb15a3f20]::known_panics_lint::ConstPropagator as rustc_middle[d099a8b084c78b18]::mir::visit::Visitor>::visit_body
  25:     0x7e3cb95f79f9 - <rustc_mir_transform[e7af90bdb15a3f20]::known_panics_lint::KnownPanicsLint as rustc_mir_transform[e7af90bdb15a3f20]::pass_manager::MirLint>::run_lint
  26:     0x7e3cb880b6f3 - rustc_mir_transform[e7af90bdb15a3f20]::run_analysis_to_runtime_passes
  27:     0x7e3cb8c28174 - rustc_mir_transform[e7af90bdb15a3f20]::mir_drops_elaborated_and_const_checked
  28:     0x7e3cb8c27da5 - rustc_query_impl[283282ac12660651]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[283282ac12660651]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 8usize]>>
  29:     0x7e3cb8c2bcd9 - rustc_query_system[57efd1c10fae1b2]::query::plumbing::try_execute_query::<rustc_query_impl[283282ac12660651]::DynamicConfig<rustc_data_structures[ff6b6eb237e26604]::vec_cache::VecCache<rustc_span[6fdbe82b95f770dc]::def_id::LocalDefId, rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[57efd1c10fae1b2]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[283282ac12660651]::plumbing::QueryCtxt, true>
  30:     0x7e3cb8c24dae - rustc_query_impl[283282ac12660651]::query_impl::mir_drops_elaborated_and_const_checked::get_query_incr::__rust_end_short_backtrace
  31:     0x7e3cb8c248f3 - <rustc_middle[d099a8b084c78b18]::hir::map::Map>::par_body_owners::<rustc_interface[5facaafd3cd44e6f]::passes::run_required_analyses::{closure#3}::{closure#0}>::{closure#0}
  32:     0x7e3cb8c21df4 - rustc_interface[5facaafd3cd44e6f]::passes::run_required_analyses
  33:     0x7e3cb976ca9e - rustc_interface[5facaafd3cd44e6f]::passes::analysis
  34:     0x7e3cb976ca6f - rustc_query_impl[283282ac12660651]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[283282ac12660651]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 0usize]>>
  35:     0x7e3cb97683cf - rustc_query_system[57efd1c10fae1b2]::query::plumbing::try_execute_query::<rustc_query_impl[283282ac12660651]::DynamicConfig<rustc_query_system[57efd1c10fae1b2]::query::caches::SingleCache<rustc_middle[d099a8b084c78b18]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[283282ac12660651]::plumbing::QueryCtxt, true>
  36:     0x7e3cb9767d47 - rustc_query_impl[283282ac12660651]::query_impl::analysis::get_query_incr::__rust_end_short_backtrace
  37:     0x7e3cb9820669 - rustc_interface[5facaafd3cd44e6f]::passes::create_and_enter_global_ctxt::<core[b8d8efd06dd057cd]::option::Option<rustc_interface[5facaafd3cd44e6f]::queries::Linker>, rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  38:     0x7e3cb9813896 - rustc_interface[5facaafd3cd44e6f]::interface::run_compiler::<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}
  39:     0x7e3cb9670807 - std[4faddc71fb6fa0e5]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_with_globals<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_pool_with_globals<rustc_interface[5facaafd3cd44e6f]::interface::run_compiler<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  40:     0x7e3cb96704d9 - <<std[4faddc71fb6fa0e5]::thread::Builder>::spawn_unchecked_<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_with_globals<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_pool_with_globals<rustc_interface[5facaafd3cd44e6f]::interface::run_compiler<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[b8d8efd06dd057cd]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  41:     0x7e3cb966fc6b - std::sys::pal::unix::thread::Thread::new::thread_start::h07063fc11dcd9adf
  42:     0x7e3cb389ca94 - start_thread
                               at ./nptl/pthread_create.c:447:8
  43:     0x7e3cb3929c3c - clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:78:0
  44:                0x0 - <unknown>


rustc version: 1.86.0-nightly (9a1d156f3 2025-01-19)
platform: x86_64-unknown-linux-gnu

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `main::{constant#0}`
#1 [eval_to_const_value_raw] simplifying constant for the type system `main::{constant#0}`
#2 [mir_drops_elaborated_and_const_checked] elaborating drops for `main`
#3 [analysis] running analysis passes on this crate
end of query stack

Meta

rustc --version --verbose:

rustc 1.86.0-nightly (9a1d156f3 2025-01-19)
binary: rustc
commit-hash: 9a1d156f38c51441ee51e5a068f1d0caf4bb0f27
commit-date: 2025-01-19
host: x86_64-unknown-linux-gnu
release: 1.86.0-nightly
LLVM version: 19.1.7

Error output

Error output 
thread 'rustc' panicked at /rustc/9a1d156f38c51441ee51e5a068f1d0caf4bb0f27/compiler/rustc_const_eval/src/interpret/call.rs:253:13:
assertion failed: caller_abi.eq_abi(callee_abi)
stack backtrace:
   0:     0x78aed8af951a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h70d5098cfd90b01a
   1:     0x78aed9212da6 - core::fmt::write::h854c563aac02d08a
   2:     0x78aeda171291 - std::io::Write::write_fmt::hac4174e389a0e8e6
   3:     0x78aed8af9372 - std::sys::backtrace::BacktraceLock::print::hc6aba0d6b3a91e1f
   4:     0x78aed8afb7f2 - std::panicking::default_hook::{{closure}}::h9628a97795328020
   5:     0x78aed8afb67a - std::panicking::default_hook::h0dc7e102448ae736
   6:     0x78aed7c59eeb - std[4faddc71fb6fa0e5]::panicking::update_hook::<alloc[c55780341d73682]::boxed::Box<rustc_driver_impl[80a9ca323d3e3890]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x78aed8afc333 - std::panicking::rust_panic_with_hook::hf47d9e178e038701
   8:     0x78aed8afbff6 - std::panicking::begin_panic_handler::{{closure}}::hd9b9f2d3dd54e86c
   9:     0x78aed8af99e9 - std::sys::backtrace::__rust_end_short_backtrace::h342bb668fc58e319
  10:     0x78aed8afbced - rust_begin_unwind
  11:     0x78aed57a8db0 - core::panicking::panic_fmt::hb3cd74fdfc019257
  12:     0x78aed6297b9c - core::panicking::panic::h92e08174b9fe42d1
  13:     0x592a4689f7ae - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<miri[d18ac4a41561b88d]::machine::MiriMachine>>::check_argument_compat
  14:     0x592a4689ec5a - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<miri[d18ac4a41561b88d]::machine::MiriMachine>>::init_stack_frame
  15:     0x592a4689c98b - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<miri[d18ac4a41561b88d]::machine::MiriMachine>>::init_fn_call
  16:     0x592a46915db4 - miri[d18ac4a41561b88d]::eval::eval_entry::{closure#0}
  17:     0x592a46911e9b - miri[d18ac4a41561b88d]::eval::eval_entry
  18:     0x592a467c4226 - <miri[e9b5d2e94aebaf6c]::MiriCompilerCalls as rustc_driver_impl[80a9ca323d3e3890]::Callbacks>::after_analysis
  19:     0x78aeda220676 - rustc_interface[5facaafd3cd44e6f]::passes::create_and_enter_global_ctxt::<core[b8d8efd06dd057cd]::option::Option<rustc_interface[5facaafd3cd44e6f]::queries::Linker>, rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  20:     0x78aeda213896 - rustc_interface[5facaafd3cd44e6f]::interface::run_compiler::<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}
  21:     0x78aeda070807 - std[4faddc71fb6fa0e5]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_with_globals<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_pool_with_globals<rustc_interface[5facaafd3cd44e6f]::interface::run_compiler<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  22:     0x78aeda0704d9 - <<std[4faddc71fb6fa0e5]::thread::Builder>::spawn_unchecked_<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_with_globals<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_pool_with_globals<rustc_interface[5facaafd3cd44e6f]::interface::run_compiler<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[b8d8efd06dd057cd]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  23:     0x78aeda06fc6b - std::sys::pal::unix::thread::Thread::new::thread_start::h07063fc11dcd9adf
  24:     0x78aed429ca94 - start_thread
                               at ./nptl/pthread_create.c:447:8
  25:     0x78aed4329c3c - clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:78:0
  26:                0x0 - <unknown>

error: the compiler unexpectedly panicked. this is a bug.

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

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

note: please attach the file at `/tmp/sadkjlhfsakdf/rustc-ice-2025-01-21T00_17_45-3693735.txt` to your bug report

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

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:7:5
   |
7  |     panic!()
   |     ^^^^^^^^
   |
   = note: BACKTRACE:
   = note: inside `foo` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/panic.rs:90:9: 90:30
note: inside `main`
  --> src/main.rs:12:5
   |
12 |     f();
   |     ^^^
   = note: inside `<fn() as std::ops::FnOnce<()>>::call_once - shim(fn())` at /home/zachary/.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::backtrace::__rust_begin_short_backtrace::<fn(), ()>` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/sys/backtrace.rs:152:18: 152:21
   = note: inside closure at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:194:18: 194:75
   = 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/zachary/.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/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:587:40: 587:43
   = note: inside `std::panicking::r#try::<i32, &dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe>` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:550:19: 550:88
   = note: inside `std::panic::catch_unwind::<&dyn std::ops::Fn() -> i32 + std::marker::Sync + std::panic::RefUnwindSafe, i32>` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:358:14: 358:33
   = note: inside closure at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:163:24: 163:49
   = note: inside `std::panicking::r#try::do_call::<{closure@std::rt::lang_start_internal::{closure#0}}, isize>` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:587:40: 587:43
   = note: inside `std::panicking::r#try::<isize, {closure@std::rt::lang_start_internal::{closure#0}}>` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:550:19: 550:88
   = note: inside `std::panic::catch_unwind::<{closure@std::rt::lang_start_internal::{closure#0}}, isize>` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:358:14: 358:33
   = note: inside `std::rt::lang_start_internal` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:159:5: 181:7
   = note: inside `std::rt::lang_start::<()>` at /home/zachary/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/rt.rs:193:5: 198:6
   = note: this note originates in the macro `$crate::panic::panic_2021` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
ICE file 

thread 'rustc' panicked at /rustc/9a1d156f38c51441ee51e5a068f1d0caf4bb0f27/compiler/rustc_const_eval/src/interpret/call.rs:253:13:
assertion failed: caller_abi.eq_abi(callee_abi)
stack backtrace:
   0:     0x78aeda5652a5 - std::backtrace::Backtrace::create::h8985a2f6ef2eb84f
   1:     0x78aed8ae39f5 - std::backtrace::Backtrace::force_capture::h9a611efb2a942dc9
   2:     0x78aed7c5a4e0 - std[4faddc71fb6fa0e5]::panicking::update_hook::<alloc[c55780341d73682]::boxed::Box<rustc_driver_impl[80a9ca323d3e3890]::install_ice_hook::{closure#1}>>::{closure#0}
   3:     0x78aed8afc333 - std::panicking::rust_panic_with_hook::hf47d9e178e038701
   4:     0x78aed8afbff6 - std::panicking::begin_panic_handler::{{closure}}::hd9b9f2d3dd54e86c
   5:     0x78aed8af99e9 - std::sys::backtrace::__rust_end_short_backtrace::h342bb668fc58e319
   6:     0x78aed8afbced - rust_begin_unwind
   7:     0x78aed57a8db0 - core::panicking::panic_fmt::hb3cd74fdfc019257
   8:     0x78aed6297b9c - core::panicking::panic::h92e08174b9fe42d1
   9:     0x592a4689f7ae - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<miri[d18ac4a41561b88d]::machine::MiriMachine>>::check_argument_compat
  10:     0x592a4689ec5a - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<miri[d18ac4a41561b88d]::machine::MiriMachine>>::init_stack_frame
  11:     0x592a4689c98b - <rustc_const_eval[e3d2a21e14ef9d90]::interpret::eval_context::InterpCx<miri[d18ac4a41561b88d]::machine::MiriMachine>>::init_fn_call
  12:     0x592a46915db4 - miri[d18ac4a41561b88d]::eval::eval_entry::{closure#0}
  13:     0x592a46911e9b - miri[d18ac4a41561b88d]::eval::eval_entry
  14:     0x592a467c4226 - <miri[e9b5d2e94aebaf6c]::MiriCompilerCalls as rustc_driver_impl[80a9ca323d3e3890]::Callbacks>::after_analysis
  15:     0x78aeda220676 - rustc_interface[5facaafd3cd44e6f]::passes::create_and_enter_global_ctxt::<core[b8d8efd06dd057cd]::option::Option<rustc_interface[5facaafd3cd44e6f]::queries::Linker>, rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  16:     0x78aeda213896 - rustc_interface[5facaafd3cd44e6f]::interface::run_compiler::<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}
  17:     0x78aeda070807 - std[4faddc71fb6fa0e5]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_with_globals<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_pool_with_globals<rustc_interface[5facaafd3cd44e6f]::interface::run_compiler<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  18:     0x78aeda0704d9 - <<std[4faddc71fb6fa0e5]::thread::Builder>::spawn_unchecked_<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_with_globals<rustc_interface[5facaafd3cd44e6f]::util::run_in_thread_pool_with_globals<rustc_interface[5facaafd3cd44e6f]::interface::run_compiler<(), rustc_driver_impl[80a9ca323d3e3890]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[b8d8efd06dd057cd]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  19:     0x78aeda06fc6b - std::sys::pal::unix::thread::Thread::new::thread_start::h07063fc11dcd9adf
  20:     0x78aed429ca94 - start_thread
                               at ./nptl/pthread_create.c:447:8
  21:     0x78aed4329c3c - clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:78:0
  22:                0x0 - <unknown>


rustc version: 1.86.0-nightly (9a1d156f3 2025-01-19)
platform: x86_64-unknown-linux-gnu

query stack during panic:
end of query stack

@rustbot label +A-miri +A-ABI

This shouldn't ICE regardless, but whether there is a miscompilation depends on if the original code is sound:

CC rust-lang/unsafe-code-guidelines#485

Possible Miscompilation

Does #[repr(transparent)]s ABI-compatility guarantee apply in the prescence of uninhabited 1-ZST fields?

A #[repr(transparent)] wrapper that contains an uninhabited 1-ZST field gets Uninhabited ABI IIUC, which may contradict the guarantees about #[repr(transparent)] wrappers being ABI-compatible.

Consider Foo from above:

type Field = u8; // any non-1ZST probably
#[repr(transparent)]
struct Foo {
  _zst: std::convert::Infallible,
  _field: Field,
}

If #[repr(transparent)]'s ABI-compatility guarantees do apply, then the above code should be sound:

  1. If a function returns Foo, it must diverge (e.g. by panicking).
  2. If Foo is ABI-compatible with Field, then it should be sound to transmute a function pointer to a diverging fn() -> Foo into a fn() -> Field that also diverges.
rustc_layout(debug)

Using #![feature(rustc_attrs)] and #[rustc_layout(debug)] we see that the ABI it has is

error: layout_of(Foo) = Layout {
          // snip
           abi: Uninhabited,
          // snip
       }

whereas Field has

error: layout_of(u8) = Layout {
           // snip
           abi: Scalar(
               Initialized {
                   value: Int(
                       I8,
                       false,
                   ),
                   valid_range: 0..=255,
               },
           ),
           // snip
        }

Possible Miscompilation

Assuming this is supposed to be sound, then there is an observable miscompilation here too. Where Field is returned by invisible reference, fn(u32) -> Foo does not return Foo by invisible reference, so transmuting fn(u32) -> Foo into fn(u32) -> Field will pass a different number of arguments.

Specifically on x86_64-unknown-linux-gnu: If Field is returned on the stack, then fn(..) -> Foo does not reserve stack space or pass a hidden reference parameter, but fn(..) -> Field does. This can be made into an observable miscompilation if the function takes parameters: (playground link, IIUC: the invisible reference is being passed, but the callee isn't expecting it, so it thinks it's the first "real" parameter instead (caller: ret by-ref in rdi, x in rsi; callee: ret uninhabited, x in rdi)).

Footnotes

  1. see "Possible Miscompilation" section ↩
@zachs18 zachs18 added C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jan 21, 2025
@rustbot rustbot added needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. A-ABI Area: Concerning the application binary interface (ABI) A-miri Area: The miri tool labels Jan 21, 2025
@zachs18 zachs18 mentioned this issue Jan 21, 2025
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ia0 commented Jan 21, 2025

I would argue the original code is unsound. The intent (coming from the name) of repr(transparent) is to have the same runtime behavior as the "wrapped" field. Using an uninhabited 1-ZST breaks this intent. I believe this is an oversight of layout.repr.transparent.constraint-field. In particular, I would expect the first bullet point to be (added term in bold):

  • any number of inhabited fields with size 0 and alignment 1 (e.g. PhantomData<T>), and

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A-ABI Area: Concerning the application binary interface (ABI) A-miri Area: The miri tool C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
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