ICE: `expected wide pointer extra data`

[matthiaskrgr]

auto-reduced (treereduce-rust):

fn main() {
    extern "C" {
        static symbol: [usize];
    }
    println!("{}", symbol[0]);
}

original:

//~ ERROR rustc_outlives

const _: bool = false && false;
const _: bool = true && false;
const _: bool = {
    let mut x = true && false;
    x
};
const _TOO_LOW: () = { u64::from_str_radix("12345ABCD" 1); };

fn main() {
    extern "C" {
        static symbol: [usize]; //~ ERROR: the size for values of type
    }
    println!("{}", symbol[0]);
    //~^ ERROR: extern static is unsafe
}

Version information

rustc 1.83.0-nightly (851f69868 2024-09-28)
binary: rustc
commit-hash: 851f698682aa2e4c226e1a2c1af30adbcb63aae2
commit-date: 2024-09-28
host: x86_64-unknown-linux-gnu
release: 1.83.0-nightly
LLVM version: 19.1.0

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zmir-opt-level=5 -Zvalidate-mir

Program output

error[E0277]: the size for values of type `[usize]` cannot be known at compilation time
 --> /tmp/icemaker_global_tempdir.UzS9t28kBj7Z/rustc_testrunner_tmpdir_reporting.ClR4SdutAcRi/mvce.rs:3:24
  |
3 |         static symbol: [usize];
  |                        ^^^^^^^ doesn't have a size known at compile-time
  |
  = help: the trait `Sized` is not implemented for `[usize]`

error[E0133]: use of extern static is unsafe and requires unsafe function or block
 --> /tmp/icemaker_global_tempdir.UzS9t28kBj7Z/rustc_testrunner_tmpdir_reporting.ClR4SdutAcRi/mvce.rs:5:20
  |
5 |     println!("{}", symbol[0]);
  |                    ^^^^^^ use of extern static
  |
  = note: extern statics are not controlled by the Rust type system: invalid data, aliasing violations or data races will cause undefined behavior

error: internal compiler error: /rustc/851f698682aa2e4c226e1a2c1af30adbcb63aae2/compiler/rustc_const_eval/src/interpret/place.rs:36:17: expected wide pointer extra data (e.g. slice length or trait object vtable)

thread 'rustc' panicked at /rustc/851f698682aa2e4c226e1a2c1af30adbcb63aae2/compiler/rustc_const_eval/src/interpret/place.rs:36:17:
Box<dyn Any>
stack backtrace:
   0:     0x7407a38ceaba - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h7900a3ecde60f42e
   1:     0x7407a40037e6 - core::fmt::write::h550ce993e33b1b64
   2:     0x7407a51ae991 - std::io::Write::write_fmt::h934b266016a01ab9
   3:     0x7407a38ce912 - std::sys::backtrace::BacktraceLock::print::hfed7190cfb479085
   4:     0x7407a38d0e31 - std::panicking::default_hook::{{closure}}::hf3239a9153976196
   5:     0x7407a38d0c64 - std::panicking::default_hook::ha9ae936b7eae362b
   6:     0x7407a299a03f - std[7abf0287877b87c3]::panicking::update_hook::<alloc[dcdda265b4d77909]::boxed::Box<rustc_driver_impl[2b0d10d4d558aac7]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x7407a38d1548 - std::panicking::rust_panic_with_hook::h62359f8c356e73f3
   8:     0x7407a29d41e1 - std[7abf0287877b87c3]::panicking::begin_panic::<rustc_errors[47f0f04182922d6e]::ExplicitBug>::{closure#0}
   9:     0x7407a29c7286 - std[7abf0287877b87c3]::sys::backtrace::__rust_end_short_backtrace::<std[7abf0287877b87c3]::panicking::begin_panic<rustc_errors[47f0f04182922d6e]::ExplicitBug>::{closure#0}, !>
  10:     0x7407a29c2769 - std[7abf0287877b87c3]::panicking::begin_panic::<rustc_errors[47f0f04182922d6e]::ExplicitBug>
  11:     0x7407a29dda71 - <rustc_errors[47f0f04182922d6e]::diagnostic::BugAbort as rustc_errors[47f0f04182922d6e]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x7407a30020a4 - rustc_middle[8066596e1db03fa9]::util::bug::opt_span_bug_fmt::<rustc_span[19f86c6d4b17e07c]::span_encoding::Span>::{closure#0}
  13:     0x7407a2fe7dea - rustc_middle[8066596e1db03fa9]::ty::context::tls::with_opt::<rustc_middle[8066596e1db03fa9]::util::bug::opt_span_bug_fmt<rustc_span[19f86c6d4b17e07c]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x7407a2fe7c7b - rustc_middle[8066596e1db03fa9]::ty::context::tls::with_context_opt::<rustc_middle[8066596e1db03fa9]::ty::context::tls::with_opt<rustc_middle[8066596e1db03fa9]::util::bug::opt_span_bug_fmt<rustc_span[19f86c6d4b17e07c]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x7407a05cd630 - rustc_middle[8066596e1db03fa9]::util::bug::bug_fmt
  16:     0x7407a312dcf3 - <rustc_const_eval[45b572bde6308908]::interpret::place::MPlaceTy as rustc_const_eval[45b572bde6308908]::interpret::projection::Projectable<rustc_middle[8066596e1db03fa9]::mir::interpret::pointer::CtfeProvenance>>::len::<rustc_const_eval[45b572bde6308908]::const_eval::dummy_machine::DummyMachine>
  17:     0x7407a4a53010 - <rustc_mir_transform[7719501850dfb079]::gvn::VnState>::insert
  18:     0x7407a4a4519c - <rustc_mir_transform[7719501850dfb079]::gvn::VnState>::simplify_rvalue
  19:     0x7407a16394e4 - <rustc_mir_transform[7719501850dfb079]::gvn::GVN as rustc_mir_transform[7719501850dfb079]::pass_manager::MirPass>::run_pass
  20:     0x7407a400bd8d - rustc_mir_transform[7719501850dfb079]::pass_manager::run_passes_inner
  21:     0x7407a4a075e2 - rustc_mir_transform[7719501850dfb079]::optimized_mir
  22:     0x7407a4a05e9d - rustc_query_impl[6f1e8f04bf490f6a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6f1e8f04bf490f6a]::query_impl::optimized_mir::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8066596e1db03fa9]::query::erase::Erased<[u8; 8usize]>>
  23:     0x7407a402fa38 - rustc_query_system[808f2ed519714d18]::query::plumbing::try_execute_query::<rustc_query_impl[6f1e8f04bf490f6a]::DynamicConfig<rustc_query_system[808f2ed519714d18]::query::caches::DefIdCache<rustc_middle[8066596e1db03fa9]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[6f1e8f04bf490f6a]::plumbing::QueryCtxt, false>
  24:     0x7407a402eff3 - rustc_query_impl[6f1e8f04bf490f6a]::query_impl::optimized_mir::get_query_non_incr::__rust_end_short_backtrace
  25:     0x7407a1480699 - <rustc_middle[8066596e1db03fa9]::ty::context::TyCtxt>::instance_mir
  26:     0x7407a43a47dc - rustc_interface[a8f766607a628292]::passes::run_required_analyses
  27:     0x7407a4b068de - rustc_interface[a8f766607a628292]::passes::analysis
  28:     0x7407a4b068b1 - rustc_query_impl[6f1e8f04bf490f6a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[6f1e8f04bf490f6a]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8066596e1db03fa9]::query::erase::Erased<[u8; 1usize]>>
  29:     0x7407a4e7892e - rustc_query_system[808f2ed519714d18]::query::plumbing::try_execute_query::<rustc_query_impl[6f1e8f04bf490f6a]::DynamicConfig<rustc_query_system[808f2ed519714d18]::query::caches::SingleCache<rustc_middle[8066596e1db03fa9]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[6f1e8f04bf490f6a]::plumbing::QueryCtxt, false>
  30:     0x7407a4e7860f - rustc_query_impl[6f1e8f04bf490f6a]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  31:     0x7407a4d1825e - rustc_interface[a8f766607a628292]::interface::run_compiler::<core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>, rustc_driver_impl[2b0d10d4d558aac7]::run_compiler::{closure#0}>::{closure#1}
  32:     0x7407a4de3290 - std[7abf0287877b87c3]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[a8f766607a628292]::util::run_in_thread_with_globals<rustc_interface[a8f766607a628292]::util::run_in_thread_pool_with_globals<rustc_interface[a8f766607a628292]::interface::run_compiler<core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>, rustc_driver_impl[2b0d10d4d558aac7]::run_compiler::{closure#0}>::{closure#1}, core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>>::{closure#0}, core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>>
  33:     0x7407a4de38fa - <<std[7abf0287877b87c3]::thread::Builder>::spawn_unchecked_<rustc_interface[a8f766607a628292]::util::run_in_thread_with_globals<rustc_interface[a8f766607a628292]::util::run_in_thread_pool_with_globals<rustc_interface[a8f766607a628292]::interface::run_compiler<core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>, rustc_driver_impl[2b0d10d4d558aac7]::run_compiler::{closure#0}>::{closure#1}, core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>>::{closure#0}, core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9c5d060eac7beb80]::result::Result<(), rustc_span[19f86c6d4b17e07c]::ErrorGuaranteed>>::{closure#1} as core[9c5d060eac7beb80]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  34:     0x7407a4de3ceb - std::sys::pal::unix::thread::Thread::new::thread_start::ha5204e3fc18d4472
  35:     0x7407a656039d - <unknown>
  36:     0x7407a65e549c - <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 1.83.0-nightly (851f69868 2024-09-28) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=5 -Z validate-mir -Z dump-mir-dir=dir

query stack during panic:
#0 [optimized_mir] optimizing MIR for `main`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 3 previous errors

Some errors have detailed explanations: E0133, E0277.
For more information about an error, try `rustc --explain E0133`.

[matthiaskrgr]

This bisects to #128612

[jieyouxu]

Hm, it feels that it should not have reached const-eval, possibly error-tainting related?

[matthiaskrgr]

yeah, probably

mvce:

//@ compile-flags: -Zmir-opt-level=5 -Zvalidate-mir
fn main() {
    extern "C" {
        static x: [usize];
    }
    x[0];
}