ICE: could not find allocation for alloc3

[matthiaskrgr]

auto-reduced (treereduce-rust):

extern "C" {
    pub type ExternType;
}

pub struct Wrapper(ExternType);
pub static MAGIC_FFI_REF: &'static Wrapper = unsafe {
    std::mem::transmute(&{
        let y = 42;
        y
    })
};

original:

//@ check-pass

// Test that we can handle newtypes wrapping extern types

#![feature(extern_types)]

use std::marker::PhantomData;

extern "C" {
  pub type ExternType;
}
unsafe impl Sync for ExternType {}
static MAGIC_FFI_STATIC: u8 = 42;

#[repr(transparent)]
pub struct Wrapper(ExternType);
pub static MAGIC_FFI_REF: &'static Wrapper = unsafe {
  std::mem::transmute(&{ //~ ERROR temporary value dropped while borrowed
        let y = 42;
        y
    })
};

#[repr(MAGIC_FFI_REF2)]
pub struct Wrapper2(PhantomData<Vec<i32>>, ExternType);
pub static MAGIC_FFI_REF2: &'static Wrapper2 = unsafe {
  std::mem::transmute(&MAGIC_FFI_STATIC)
};

fn main() {}

Version information

rustc 1.81.0-nightly (c25ac9d6c 2024-06-12)
binary: rustc
commit-hash: c25ac9d6cc285e57e1176dc2da6848b9d0163810
commit-date: 2024-06-12
host: x86_64-unknown-linux-gnu
release: 1.81.0-nightly
LLVM version: 18.1.7

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

error[E0658]: extern types are experimental
 --> /tmp/icemaker_global_tempdir.SZuuVndvH6Hc/rustc_testrunner_tmpdir_reporting.sWVUdMqkpzcR/mvce.rs:2:5
  |
2 |     pub type ExternType;
  |     ^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #43467 <https://github.com/rust-lang/rust/issues/43467> for more information
  = help: add `#![feature(extern_types)]` to the crate attributes to enable
  = note: this compiler was built on 2024-06-12; consider upgrading it if it is out of date

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.SZuuVndvH6Hc/rustc_testrunner_tmpdir_reporting.sWVUdMqkpzcR/mvce.rs:11:3
   |
11 | };
   |   ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.SZuuVndvH6Hc/rustc_testrunner_tmpdir_reporting.sWVUdMqkpzcR/mvce.rs`

error[E0277]: `ExternType` cannot be shared between threads safely
 --> /tmp/icemaker_global_tempdir.SZuuVndvH6Hc/rustc_testrunner_tmpdir_reporting.sWVUdMqkpzcR/mvce.rs:6:27
  |
6 | pub static MAGIC_FFI_REF: &'static Wrapper = unsafe {
  |                           ^^^^^^^^^^^^^^^^ `ExternType` cannot be shared between threads safely
  |
  = help: within `&'static Wrapper`, the trait `Sync` is not implemented for `ExternType`, which is required by `&'static Wrapper: Sync`
note: required because it appears within the type `Wrapper`
 --> /tmp/icemaker_global_tempdir.SZuuVndvH6Hc/rustc_testrunner_tmpdir_reporting.sWVUdMqkpzcR/mvce.rs:5:12
  |
5 | pub struct Wrapper(ExternType);
  |            ^^^^^^^
  = note: required because it appears within the type `&'static Wrapper`
  = note: shared static variables must have a type that implements `Sync`

error: internal compiler error: compiler/rustc_const_eval/src/interpret/validity.rs:708:19: could not find allocation for alloc2

thread 'rustc' panicked at compiler/rustc_const_eval/src/interpret/validity.rs:708:19:
Box<dyn Any>
stack backtrace:
   0:     0x77051b809ae5 - std::backtrace_rs::backtrace::libunwind::trace::h6be50cef0e090531
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/../../backtrace/src/backtrace/libunwind.rs:116:5
   1:     0x77051b809ae5 - std::backtrace_rs::backtrace::trace_unsynchronized::h84167074cb4f1713
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x77051b809ae5 - std::sys_common::backtrace::_print_fmt::hb5cf039fd1f30b07
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x77051b809ae5 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h01adaba1565f117f
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x77051b85a77b - core::fmt::rt::Argument::fmt::h2910e36f4e21d32d
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/core/src/fmt/rt.rs:165:63
   5:     0x77051b85a77b - core::fmt::write::h6d9d2f7ff8571b34
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/core/src/fmt/mod.rs:1168:21
   6:     0x77051b7fe6bf - std::io::Write::write_fmt::hd882c0f914f56bf0
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/io/mod.rs:1835:15
   7:     0x77051b8098be - std::sys_common::backtrace::_print::hcc6c907dafd9aacb
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x77051b8098be - std::sys_common::backtrace::print::h2c716a051c9b24be
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x77051b80c2f9 - std::panicking::default_hook::{{closure}}::he8ad829f77bd4e23
  10:     0x77051b80c09c - std::panicking::default_hook::heb22a1402d2cff23
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/panicking.rs:292:9
  11:     0x7705180b2c9f - std[5c07af62f3786d14]::panicking::update_hook::<alloc[eebcfc85002bd7db]::boxed::Box<rustc_driver_impl[2b4723ede88f52b1]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x77051b80cbff - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hd8f0fcaec26c179e
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/alloc/src/boxed.rs:2076:9
  13:     0x77051b80cbff - std::panicking::rust_panic_with_hook::hc9dbad8884217847
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/panicking.rs:801:13
  14:     0x7705180e3621 - std[5c07af62f3786d14]::panicking::begin_panic::<rustc_errors[d9dad43edaa48690]::ExplicitBug>::{closure#0}
  15:     0x7705180e03d6 - std[5c07af62f3786d14]::sys_common::backtrace::__rust_end_short_backtrace::<std[5c07af62f3786d14]::panicking::begin_panic<rustc_errors[d9dad43edaa48690]::ExplicitBug>::{closure#0}, !>
  16:     0x7705180e00b6 - std[5c07af62f3786d14]::panicking::begin_panic::<rustc_errors[d9dad43edaa48690]::ExplicitBug>
  17:     0x7705180ecb71 - <rustc_errors[d9dad43edaa48690]::diagnostic::BugAbort as rustc_errors[d9dad43edaa48690]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  18:     0x7705185da21c - rustc_middle[f645b954b6a941ee]::util::bug::opt_span_bug_fmt::<rustc_span[9012e0e35e67507c]::span_encoding::Span>::{closure#0}
  19:     0x7705185c328a - rustc_middle[f645b954b6a941ee]::ty::context::tls::with_opt::<rustc_middle[f645b954b6a941ee]::util::bug::opt_span_bug_fmt<rustc_span[9012e0e35e67507c]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  20:     0x7705185c310b - rustc_middle[f645b954b6a941ee]::ty::context::tls::with_context_opt::<rustc_middle[f645b954b6a941ee]::ty::context::tls::with_opt<rustc_middle[f645b954b6a941ee]::util::bug::opt_span_bug_fmt<rustc_span[9012e0e35e67507c]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  21:     0x770515fdddb0 - rustc_middle[f645b954b6a941ee]::util::bug::bug_fmt
  22:     0x77051aa9a7bd - rustc_const_eval[6538e0f20481f9b7]::interpret::validity::mutability::<rustc_const_eval[6538e0f20481f9b7]::const_eval::machine::CompileTimeInterpreter>.cold
  23:     0x770519b54b22 - <rustc_const_eval[6538e0f20481f9b7]::interpret::validity::ValidityVisitor<rustc_const_eval[6538e0f20481f9b7]::const_eval::machine::CompileTimeInterpreter>>::check_safe_pointer
  24:     0x770519b6f0c9 - <rustc_const_eval[6538e0f20481f9b7]::interpret::eval_context::InterpCx<rustc_const_eval[6538e0f20481f9b7]::const_eval::machine::CompileTimeInterpreter>>::validate_operand_internal
  25:     0x77051a5c1ae9 - rustc_const_eval[6538e0f20481f9b7]::const_eval::eval_queries::eval_body_using_ecx::<rustc_middle[f645b954b6a941ee]::mir::interpret::allocation::ConstAllocation>
  26:     0x77051a581705 - rustc_const_eval[6538e0f20481f9b7]::const_eval::eval_queries::eval_static_initializer_provider
  27:     0x77051a5814a7 - rustc_query_impl[860f4585269295fe]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[860f4585269295fe]::query_impl::eval_static_initializer::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f645b954b6a941ee]::query::erase::Erased<[u8; 16usize]>>
  28:     0x77051a581489 - <rustc_query_impl[860f4585269295fe]::query_impl::eval_static_initializer::dynamic_query::{closure#2} as core[207868f0da9fe1eb]::ops::function::FnOnce<(rustc_middle[f645b954b6a941ee]::ty::context::TyCtxt, rustc_span[9012e0e35e67507c]::def_id::DefId)>>::call_once
  29:     0x770519a1cc80 - rustc_query_system[88bb5c8529314a04]::query::plumbing::try_execute_query::<rustc_query_impl[860f4585269295fe]::DynamicConfig<rustc_query_system[88bb5c8529314a04]::query::caches::DefIdCache<rustc_middle[f645b954b6a941ee]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[860f4585269295fe]::plumbing::QueryCtxt, false>
  30:     0x77051a2416c3 - rustc_query_impl[860f4585269295fe]::query_impl::eval_static_initializer::get_query_non_incr::__rust_end_short_backtrace
  31:     0x7705196b868a - <rustc_middle[f645b954b6a941ee]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[f165ce28b444ebe1]::check_crate::{closure#3}>::{closure#0}
  32:     0x7705196b69a2 - rustc_hir_analysis[f165ce28b444ebe1]::check_crate
  33:     0x770519e4f13e - rustc_interface[8465b2f8b714accd]::passes::analysis
  34:     0x770519e4ec87 - rustc_query_impl[860f4585269295fe]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[860f4585269295fe]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f645b954b6a941ee]::query::erase::Erased<[u8; 1usize]>>
  35:     0x77051a1f7d25 - rustc_query_system[88bb5c8529314a04]::query::plumbing::try_execute_query::<rustc_query_impl[860f4585269295fe]::DynamicConfig<rustc_query_system[88bb5c8529314a04]::query::caches::SingleCache<rustc_middle[f645b954b6a941ee]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[860f4585269295fe]::plumbing::QueryCtxt, false>
  36:     0x77051a1f7a8f - rustc_query_impl[860f4585269295fe]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  37:     0x77051a0d0952 - rustc_interface[8465b2f8b714accd]::interface::run_compiler::<core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>, rustc_driver_impl[2b4723ede88f52b1]::run_compiler::{closure#0}>::{closure#1}
  38:     0x77051a0ef649 - std[5c07af62f3786d14]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[8465b2f8b714accd]::util::run_in_thread_with_globals<rustc_interface[8465b2f8b714accd]::util::run_in_thread_pool_with_globals<rustc_interface[8465b2f8b714accd]::interface::run_compiler<core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>, rustc_driver_impl[2b4723ede88f52b1]::run_compiler::{closure#0}>::{closure#1}, core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>>::{closure#0}, core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>>
  39:     0x77051a0ef3fa - <<std[5c07af62f3786d14]::thread::Builder>::spawn_unchecked_<rustc_interface[8465b2f8b714accd]::util::run_in_thread_with_globals<rustc_interface[8465b2f8b714accd]::util::run_in_thread_pool_with_globals<rustc_interface[8465b2f8b714accd]::interface::run_compiler<core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>, rustc_driver_impl[2b4723ede88f52b1]::run_compiler::{closure#0}>::{closure#1}, core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>>::{closure#0}, core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[207868f0da9fe1eb]::result::Result<(), rustc_span[9012e0e35e67507c]::ErrorGuaranteed>>::{closure#2} as core[207868f0da9fe1eb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  40:     0x77051b816a7b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd64233370b4bbb13
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/alloc/src/boxed.rs:2062:9
  41:     0x77051b816a7b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h8b9a0bf226b4eb10
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/alloc/src/boxed.rs:2062:9
  42:     0x77051b816a7b - std::sys::pal::unix::thread::Thread::new::thread_start::h25e4cee516ffa27e
                               at /rustc/c25ac9d6cc285e57e1176dc2da6848b9d0163810/library/std/src/sys/pal/unix/thread.rs:108:17
  43:     0x770514ca6ded - <unknown>
  44:     0x770514d2a0dc - <unknown>
  45:                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 1.81.0-nightly (c25ac9d6c 2024-06-12) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [eval_static_initializer] evaluating initializer of static `MAGIC_FFI_REF`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 4 previous errors

Some errors have detailed explanations: E0277, E0601, E0658.
For more information about an error, try `rustc --explain E0277`.

@rustbot label +F-extern_types

[matthiaskrgr]

Regression in nightly-2024-05-23

#117329 cc @RalfJung 🤔

[RalfJung]

#[repr(MAGIC_FFI_REF2)]

But why?^^
Anyway it doesn't seem to affect the test.

[RalfJung]

This is not a recent regression, here's a reproducer on stable:

pub struct Wrapper;
pub static MAGIC_FFI_REF: &'static Wrapper = unsafe {
    std::mem::transmute(&{
        let y = 42;
        y
    })
};

[matthiaskrgr]

But why?^^

lol XD its just side effect of the fuzzing I guess :D