Closed
Description
auto-reduced (treereduce-rust):
mod assert {
use std::mem::{Assume, BikeshedIntrinsicFrom};
pub fn is_transmutable<Src, Dst>()
where
Dst: BikeshedIntrinsicFrom<Src>,
{
}
}
#[repr(C)]
struct Zst;
#[repr(u8)]
enum V0 {
V = 0,
}
enum V2 {
V = 2,
}
enum Lopsided {
Smol(Zst),
Lorg(V0),
}
#[repr(C)]
#[repr(C)]
struct Dst(Lopsided, V2);
fn should_pad_variants() {
assert::is_transmutable::<Src, Dst>();
}
original code
original:
//! The variants of an enum must be padded with uninit bytes such that they have
//! the same length (in bytes).
#![crate_type = "lib"]
#![feature(transmutability)]
#![allow(dead_code)]
mod assert {
use std::mem::{Assume, BikeshedIntrinsicFrom};
pub fn is_transmutable<Src, Dst>()
where
Dst: BikeshedIntrinsicFrom<Src, {
Assume::ALIGNMENT
.and(Assume::LIFETIMES)
.and(Assume::SAFETY)
.and(Assume::LIFETIMES)
.and(Assume::SAFETY)
.and(Assume::SAFETY)
.and(Assume::ALIGNMENT)
}>
{}
}
#[derive(Clone, Copy)]
#[repr(C)] struct Zst;
#[derive(Clone, Copy)]
#[repr(u8)] enum V0 { V = 0 }
#[derive(Clone, Copy)]
#[repr(u8)] enum V2 { V = 2 }
#[repr(transmutability)]
enum Lopsided {
Smol(Zst),
Lorg(V0),
}
#[repr(C)] struct Src(V0, Zst V2);
#[repr(C)] struct Dst(Lopsided, V2);
fn should_pad_variants() {
// If the implementation (incorrectly) fails to pad `Lopsided::Smol` with
// an uninitialized byte, this transmutation might be (wrongly) accepted:
assert::is_transmutable::<Src, Dst>(); //~ ERROR cannot be safely transmuted
}
Version information
rustc 1.79.0-nightly (033becf83 2024-04-09)
binary: rustc
commit-hash: 033becf83c62814357f4810db149471db46ab816
commit-date: 2024-04-09
host: x86_64-unknown-linux-gnu
release: 1.79.0-nightly
LLVM version: 18.1.3
Command:
/home/matthias/.rustup/toolchains/master/bin/rustc
Program output
error[E0412]: cannot find type `Src` in this scope
--> /tmp/icemaker_global_tempdir.7GMaangOEeD3/rustc_testrunner_tmpdir_reporting.sKS3rJHCTOdj/mvce.rs:33:31
|
33 | assert::is_transmutable::<Src, Dst>();
| ^^^ not found in this scope
|
help: you might be missing a type parameter
|
32 | fn should_pad_variants<Src>() {
| +++++
warning: unused import: `Assume`
--> /tmp/icemaker_global_tempdir.7GMaangOEeD3/rustc_testrunner_tmpdir_reporting.sKS3rJHCTOdj/mvce.rs:2:20
|
2 | use std::mem::{Assume, BikeshedIntrinsicFrom};
| ^^^^^^
|
= note: `#[warn(unused_imports)]` on by default
error[E0601]: `main` function not found in crate `mvce`
--> /tmp/icemaker_global_tempdir.7GMaangOEeD3/rustc_testrunner_tmpdir_reporting.sKS3rJHCTOdj/mvce.rs:34:2
|
34 | }
| ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.7GMaangOEeD3/rustc_testrunner_tmpdir_reporting.sKS3rJHCTOdj/mvce.rs`
error[E0658]: use of unstable library feature 'transmutability'
--> /tmp/icemaker_global_tempdir.7GMaangOEeD3/rustc_testrunner_tmpdir_reporting.sKS3rJHCTOdj/mvce.rs:2:20
|
2 | use std::mem::{Assume, BikeshedIntrinsicFrom};
| ^^^^^^
|
= note: see issue #99571 <https://github.com/rust-lang/rust/issues/99571> for more information
= help: add `#![feature(transmutability)]` to the crate attributes to enable
= note: this compiler was built on 2024-04-09; consider upgrading it if it is out of date
error[E0658]: use of unstable library feature 'transmutability'
--> /tmp/icemaker_global_tempdir.7GMaangOEeD3/rustc_testrunner_tmpdir_reporting.sKS3rJHCTOdj/mvce.rs:2:28
|
2 | use std::mem::{Assume, BikeshedIntrinsicFrom};
| ^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #99571 <https://github.com/rust-lang/rust/issues/99571> for more information
= help: add `#![feature(transmutability)]` to the crate attributes to enable
= note: this compiler was built on 2024-04-09; consider upgrading it if it is out of date
error[E0658]: use of unstable library feature 'transmutability'
--> /tmp/icemaker_global_tempdir.7GMaangOEeD3/rustc_testrunner_tmpdir_reporting.sKS3rJHCTOdj/mvce.rs:6:14
|
6 | Dst: BikeshedIntrinsicFrom<Src>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #99571 <https://github.com/rust-lang/rust/issues/99571> for more information
= help: add `#![feature(transmutability)]` to the crate attributes to enable
= note: this compiler was built on 2024-04-09; consider upgrading it if it is out of date
thread 'rustc' panicked at /rustc/033becf83c62814357f4810db149471db46ab816/compiler/rustc_abi/src/lib.rs:581:13:
Size::sub: 0 - 1 would result in negative size
stack backtrace:
0: 0x79db92be6885 - std::backtrace_rs::backtrace::libunwind::trace::he2880c2699337794
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/../../backtrace/src/backtrace/libunwind.rs:105:5
1: 0x79db92be6885 - std::backtrace_rs::backtrace::trace_unsynchronized::h460ebc9cd0eb6331
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
2: 0x79db92be6885 - std::sys_common::backtrace::_print_fmt::h47b746c0604572c3
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/sys_common/backtrace.rs:68:5
3: 0x79db92be6885 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::ha907b996746f56a0
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/sys_common/backtrace.rs:44:22
4: 0x79db92c35abb - core::fmt::rt::Argument::fmt::hfe22b646b1687193
at /rustc/033becf83c62814357f4810db149471db46ab816/library/core/src/fmt/rt.rs:142:9
5: 0x79db92c35abb - core::fmt::write::h6b4a267d08f3d00d
at /rustc/033becf83c62814357f4810db149471db46ab816/library/core/src/fmt/mod.rs:1153:17
6: 0x79db92bdb3ff - std::io::Write::write_fmt::h0abdd14d11c1702a
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/io/mod.rs:1843:15
7: 0x79db92be665e - std::sys_common::backtrace::_print::hbeb8c9c7793a4a1e
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/sys_common/backtrace.rs:47:5
8: 0x79db92be665e - std::sys_common::backtrace::print::h6ca4866d684d9b00
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/sys_common/backtrace.rs:34:9
9: 0x79db92be9159 - std::panicking::default_hook::{{closure}}::h33647e3098e0b657
10: 0x79db92be8e75 - std::panicking::default_hook::ha6320bcd5d0e9cc8
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/panicking.rs:291:9
11: 0x79db8f46649f - std[5013708940097fa8]::panicking::update_hook::<alloc[d2bd3d5c53f6cb06]::boxed::Box<rustc_driver_impl[83e8eb7d3795c9f9]::install_ice_hook::{closure#0}>>::{closure#0}
12: 0x79db92be985c - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hf428354f3713bf5b
at /rustc/033becf83c62814357f4810db149471db46ab816/library/alloc/src/boxed.rs:2032:9
13: 0x79db92be985c - std::panicking::rust_panic_with_hook::h0014da0b7030d171
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/panicking.rs:792:13
14: 0x79db92be9606 - std::panicking::begin_panic_handler::{{closure}}::h639e3e9de7a3e2e4
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/panicking.rs:657:13
15: 0x79db92be6d49 - std::sys_common::backtrace::__rust_end_short_backtrace::h66ed5715b81f24d6
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/sys_common/backtrace.rs:171:18
16: 0x79db92be9337 - rust_begin_unwind
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/panicking.rs:645:5
17: 0x79db92c31f56 - core::panicking::panic_fmt::h2fea69f54f6dc828
at /rustc/033becf83c62814357f4810db149471db46ab816/library/core/src/panicking.rs:72:14
18: 0x79db8fffc247 - <rustc_abi[ad9a244720a52d55]::Size as core[b815557cbe89e06]::ops::arith::Sub>::sub::{closure#0}
19: 0x79db9000cb17 - <rustc_transmute[b6741d03a3d4c86]::layout::tree::Tree<rustc_transmute[b6741d03a3d4c86]::layout::rustc::Def, rustc_transmute[b6741d03a3d4c86]::layout::rustc::Ref>>::from_variant
20: 0x79db9000bffa - <rustc_transmute[b6741d03a3d4c86]::layout::tree::Tree<rustc_transmute[b6741d03a3d4c86]::layout::rustc::Def, rustc_transmute[b6741d03a3d4c86]::layout::rustc::Ref>>::from_enum
21: 0x79db9000c756 - <rustc_transmute[b6741d03a3d4c86]::layout::tree::Tree<rustc_transmute[b6741d03a3d4c86]::layout::rustc::Def, rustc_transmute[b6741d03a3d4c86]::layout::rustc::Ref>>::from_variant
22: 0x79db9000b43f - <rustc_transmute[b6741d03a3d4c86]::layout::tree::Tree<rustc_transmute[b6741d03a3d4c86]::layout::rustc::Def, rustc_transmute[b6741d03a3d4c86]::layout::rustc::Ref>>::from_struct
23: 0x79db9000f833 - <rustc_transmute[b6741d03a3d4c86]::rustc::TransmuteTypeEnv>::is_transmutable
24: 0x79db910150a5 - <rustc_trait_selection[f840d4be03886ec6]::traits::select::SelectionContext>::confirm_candidate
25: 0x79db8d4ba166 - <rustc_trait_selection[f840d4be03886ec6]::traits::select::SelectionContext>::evaluate_candidate
26: 0x79db9115a88c - <rustc_trait_selection[f840d4be03886ec6]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
27: 0x79db90f0f668 - <rustc_trait_selection[f840d4be03886ec6]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[f840d4be03886ec6]::traits::select::SelectionContext>::evaluate_root_obligation::{closure#0}>
28: 0x79db90f0dc9a - rustc_traits[ccae72c98d3fa03e]::evaluate_obligation::evaluate_obligation
29: 0x79db90f0d62b - rustc_query_impl[a13915abec574cc4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a13915abec574cc4]::query_impl::evaluate_obligation::dynamic_query::{closure#2}::{closure#0}, rustc_middle[867c8a7f7f3067fc]::query::erase::Erased<[u8; 2usize]>>
30: 0x79db90f0cb92 - rustc_query_system[37cb0ad7182a86b8]::query::plumbing::try_execute_query::<rustc_query_impl[a13915abec574cc4]::DynamicConfig<rustc_query_system[37cb0ad7182a86b8]::query::caches::DefaultCache<rustc_type_ir[f07d295899310239]::canonical::Canonical<rustc_middle[867c8a7f7f3067fc]::ty::context::TyCtxt, rustc_middle[867c8a7f7f3067fc]::ty::ParamEnvAnd<rustc_middle[867c8a7f7f3067fc]::ty::predicate::Predicate>>, rustc_middle[867c8a7f7f3067fc]::query::erase::Erased<[u8; 2usize]>>, false, false, false>, rustc_query_impl[a13915abec574cc4]::plumbing::QueryCtxt, false>
31: 0x79db90f0c7da - rustc_query_impl[a13915abec574cc4]::query_impl::evaluate_obligation::get_query_non_incr::__rust_end_short_backtrace
32: 0x79db8d404081 - <rustc_trait_selection[f840d4be03886ec6]::traits::fulfill::FulfillProcessor as rustc_data_structures[529620daf813c2f]::obligation_forest::ObligationProcessor>::process_obligation
33: 0x79db9080d663 - <rustc_data_structures[529620daf813c2f]::obligation_forest::ObligationForest<rustc_trait_selection[f840d4be03886ec6]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[f840d4be03886ec6]::traits::fulfill::FulfillProcessor>
34: 0x79db90fe11bf - <rustc_hir_typeck[90aadd5cc69e56e5]::fn_ctxt::FnCtxt>::check_argument_types
35: 0x79db90fd71eb - <rustc_hir_typeck[90aadd5cc69e56e5]::fn_ctxt::FnCtxt>::check_call
36: 0x79db9128d159 - <rustc_hir_typeck[90aadd5cc69e56e5]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
37: 0x79db91287a26 - <rustc_hir_typeck[90aadd5cc69e56e5]::fn_ctxt::FnCtxt>::check_block_with_expected
38: 0x79db9128d63d - <rustc_hir_typeck[90aadd5cc69e56e5]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
39: 0x79db909ee20e - rustc_hir_typeck[90aadd5cc69e56e5]::check::check_fn
40: 0x79db909e4749 - rustc_hir_typeck[90aadd5cc69e56e5]::typeck
41: 0x79db909e4109 - rustc_query_impl[a13915abec574cc4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a13915abec574cc4]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[867c8a7f7f3067fc]::query::erase::Erased<[u8; 8usize]>>
42: 0x79db909d0871 - rustc_query_system[37cb0ad7182a86b8]::query::plumbing::try_execute_query::<rustc_query_impl[a13915abec574cc4]::DynamicConfig<rustc_query_system[37cb0ad7182a86b8]::query::caches::VecCache<rustc_span[ef049dfdad08a076]::def_id::LocalDefId, rustc_middle[867c8a7f7f3067fc]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[a13915abec574cc4]::plumbing::QueryCtxt, false>
43: 0x79db909cf18c - rustc_query_impl[a13915abec574cc4]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
44: 0x79db909ced54 - <rustc_middle[867c8a7f7f3067fc]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[341fcfcfa163e951]::check_crate::{closure#4}>::{closure#0}
45: 0x79db909cda1f - rustc_hir_analysis[341fcfcfa163e951]::check_crate
46: 0x79db910ee93a - rustc_interface[791da96d69a7cf4c]::passes::analysis
47: 0x79db910ee495 - rustc_query_impl[a13915abec574cc4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a13915abec574cc4]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[867c8a7f7f3067fc]::query::erase::Erased<[u8; 1usize]>>
48: 0x79db915fa6a5 - rustc_query_system[37cb0ad7182a86b8]::query::plumbing::try_execute_query::<rustc_query_impl[a13915abec574cc4]::DynamicConfig<rustc_query_system[37cb0ad7182a86b8]::query::caches::SingleCache<rustc_middle[867c8a7f7f3067fc]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a13915abec574cc4]::plumbing::QueryCtxt, false>
49: 0x79db915fa409 - rustc_query_impl[a13915abec574cc4]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
50: 0x79db91480cd4 - rustc_interface[791da96d69a7cf4c]::interface::run_compiler::<core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>, rustc_driver_impl[83e8eb7d3795c9f9]::run_compiler::{closure#0}>::{closure#0}
51: 0x79db9154deff - std[5013708940097fa8]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[791da96d69a7cf4c]::util::run_in_thread_with_globals<rustc_interface[791da96d69a7cf4c]::util::run_in_thread_pool_with_globals<rustc_interface[791da96d69a7cf4c]::interface::run_compiler<core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>, rustc_driver_impl[83e8eb7d3795c9f9]::run_compiler::{closure#0}>::{closure#0}, core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>>::{closure#0}, core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>>
52: 0x79db9154dcee - <<std[5013708940097fa8]::thread::Builder>::spawn_unchecked_<rustc_interface[791da96d69a7cf4c]::util::run_in_thread_with_globals<rustc_interface[791da96d69a7cf4c]::util::run_in_thread_pool_with_globals<rustc_interface[791da96d69a7cf4c]::interface::run_compiler<core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>, rustc_driver_impl[83e8eb7d3795c9f9]::run_compiler::{closure#0}>::{closure#0}, core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>>::{closure#0}, core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b815557cbe89e06]::result::Result<(), rustc_span[ef049dfdad08a076]::ErrorGuaranteed>>::{closure#1} as core[b815557cbe89e06]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
53: 0x79db92bf328b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h53814b1241345312
at /rustc/033becf83c62814357f4810db149471db46ab816/library/alloc/src/boxed.rs:2018:9
54: 0x79db92bf328b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h68f33d2823fce7a0
at /rustc/033becf83c62814357f4810db149471db46ab816/library/alloc/src/boxed.rs:2018:9
55: 0x79db92bf328b - std::sys::pal::unix::thread::Thread::new::thread_start::h5c5183b404e56855
at /rustc/033becf83c62814357f4810db149471db46ab816/library/std/src/sys/pal/unix/thread.rs:108:17
56: 0x79db9299155a - <unknown>
57: 0x79db92a0ea3c - <unknown>
58: 0x0 - <unknown>
error: 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 1.79.0-nightly (033becf83 2024-04-09) running on x86_64-unknown-linux-gnu
query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `Dst: core::mem::transmutability::BikeshedIntrinsicFrom<{type error}, core::mem::transmutability::Assume { alignment: false, lifetimes: false, safety: false, validity: false }>`
#1 [typeck] type-checking `should_pad_variants`
#2 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 5 previous errors; 1 warning emitted
Some errors have detailed explanations: E0412, E0601, E0658.
For more information about an error, try `rustc --explain E0412`.
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Area: Concerning the application binary interface (ABI)Area: Memory layout of typesCategory: This is a bug.Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️Status: This bug is tracked inside the repo by a `known-bug` test.Status: A Minimal Complete and Verifiable Example has been found for this issueRelevant to the compiler team, which will review and decide on the PR/issue.