matthiaskrgr
commented
1 month ago smaller
const NULL_BOX: Box<u16> = unsafe { std::mem::transmute(&1) };Closed matthiaskrgr closed 1 month ago
matthiaskrgr
commented
1 month ago smaller
const NULL_BOX: Box<u16> = unsafe { std::mem::transmute(&1) };
auto-reduced (treereduce-rust):
original code
original: ````rust // ignore-tidy-linelength // Strip out raw byte dumps to make comparison platform-independent: //@ normalize-stderr-test: "(the raw bytes of the constant) \(size: [0-9]*, align: [0-9]*\)" -> "$1 (size: $$SIZE, align: $$ALIGN)" //@ normalize-stderr-test: "([0-9a-f][0-9a-f] |╾─*ALLOC[0-9]+(\+[a-z0-9]+)?()?─*╼ )+ *│.*" -> "HEX_DUMP"
#![allow(invalid_value)]
use std::mem;
#[repr(C)]
union MaybeUninit {
uninit: (),
init: T,
}
const UNALIGNED: &u16 = unsafe { mem::transmute(&[0u8; 4]) };
//~^ ERROR it is undefined behavior to use this value
//~| constructing invalid value: encountered an unaligned reference (required 2 byte alignment but found 1)
const UNALIGNED_BOX: Box = unsafe { mem::transmute(&[0u8; 4]) };
//~ inside `UNALIGNED_READ`
//~| constructing invalid value: encountered an unaligned box (required 2 byte alignment but found 1)
const NULL: &u16 = unsafe { mem::transmute(0usize) };
//~^ ERROR it is undefined behavior to use this value
const NULL_BOX: Box = unsafe { mem::transmute(&13) };
//~^ ERROR it is undefined behavior to use this value
// It is very important that we reject this: We do promote `&(4 * REF_AS_USIZE)`,
// but that would fail to compile; so we ended up breaking user code that would
// have worked fine had we not promoted.
const REF_AS_USIZE: usize = unsafe { mem::transmute(&0) };
//~^ ERROR evaluation of constant value failed
const REF_AS_USIZE_SLICE: &[usize] = &[unsafe { mem::transmute(&0) }];
//~^ ERROR evaluation of constant value failed
const REF_AS_USIZE_BOX_SLICE: Box<[usize]> = unsafe { mem::transmute::<&[usize], _>(&[mem::transmute(&0)]) };
//~^ ERROR evaluation of constant value failed
const USIZE_AS_REF: &'static u8 = unsafe { mem::transmute(1337usize) };
//~^ ERROR it is undefined behavior to use this value
const USIZE_AS_BOX: Box = unsafe { mem::transmute(1337usize) };
//~^ ERROR it is undefined behavior to use this value
const UNINIT_PTR: *const i32 = unsafe { MaybeUninit { uninit: () }.init };
//~^ ERROR evaluation of constant value failed
//~| uninitialized
const NULL_FN_PTR: fn() = unsafe { mem::transmute(0usize) };
//~^ ERROR it is undefined behavior to use this value
const UNINIT_FN_PTR: fn() = unsafe { MaybeUninit { uninit: () }.init };
//~^ ERROR evaluation of constant value failed
//~| uninitialized
const DANGLING_FN_PTR: fn() = unsafe { mem::transmute(13usize) };
//~^ ERROR it is undefined behavior to use this value
const DATA_FN_PTR: fn() = unsafe { mem::transmute(&13) };
//~^ ERROR it is undefined behavior to use this value
const UNALIGNED_READ: () = unsafe {
let x = &[0u8; 4];
let C = x.as_ptr().cast::();
ptr.read(); //~ inside `UNALIGNED_READ`
};
fn main() {}
````
Version information
Command:
/home/gh-matthiaskrgr/.rustup/toolchains/master/bin/rustcProgram output
``` error[E0601]: `main` function not found in crate `mvce` --> /tmp/icemaker_global_tempdir.bJIO8sESgXOC/rustc_testrunner_tmpdir_reporting.0sBZX3hnC5YA/mvce.rs:5:59 | 5 | const NULL_BOX: Box = unsafe { mem::transmute(&13) };
| ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.bJIO8sESgXOC/rustc_testrunner_tmpdir_reporting.0sBZX3hnC5YA/mvce.rs`
error[E0517]: attribute should be applied to a struct, enum, or union
--> /tmp/icemaker_global_tempdir.bJIO8sESgXOC/rustc_testrunner_tmpdir_reporting.0sBZX3hnC5YA/mvce.rs:3:8
|
3 | #[repr(C)]
| ^
4 |
5 | const NULL_BOX: Box = unsafe { mem::transmute(&13) };
| ---------------------------------------------------------- not a struct, enum, or union
error: internal compiler error: compiler/rustc_const_eval/src/interpret/validity.rs:622:33: the static const safety checks accepted mutable references they should not have accepted
--> /tmp/icemaker_global_tempdir.bJIO8sESgXOC/rustc_testrunner_tmpdir_reporting.0sBZX3hnC5YA/mvce.rs:5:1
|
5 | const NULL_BOX: Box = unsafe { mem::transmute(&13) };
| ^^^^^^^^^^^^^^^^^^^^^^^^
thread 'rustc' panicked at compiler/rustc_const_eval/src/interpret/validity.rs:622:33:
Box
stack backtrace:
0: 0x7bcdbda7b18a - ::fmt::hf56f131060334410
1: 0x7bcdbe203297 - core::fmt::write::hca99a1033ad8fb7e
2: 0x7bcdbf0ce473 - std::io::Write::write_fmt::h3ee0545282dfb25b
3: 0x7bcdbda7afe2 - std::sys::backtrace::BacktraceLock::print::he60ba974f9acf9d9
4: 0x7bcdbda7d761 - std::panicking::default_hook::{{closure}}::hde21c1684decca25
5: 0x7bcdbda7d594 - std::panicking::default_hook::h52af35cff2244cca
6: 0x7bcdbcb808af - std[a418af8a4b80da9d]::panicking::update_hook::>::{closure#0}
7: 0x7bcdbda7de88 - std::panicking::rust_panic_with_hook::h5733bff0390959c4
8: 0x7bcdbcbba091 - std[a418af8a4b80da9d]::panicking::begin_panic::::{closure#0}
9: 0x7bcdbcbad706 - std[a418af8a4b80da9d]::sys::backtrace::__rust_end_short_backtrace::::{closure#0}, !>
10: 0x7bcdbcba8e79 - std[a418af8a4b80da9d]::panicking::begin_panic::
11: 0x7bcdbcbc3211 - ::emit_producing_guarantee
12: 0x7bcdbcacad0d - ::span_bug::
13: 0x7bcdbcaec838 - rustc_middle[cdd3c0f25a03279b]::util::bug::opt_span_bug_fmt::::{closure#0}
14: 0x7bcdbcaec86a - rustc_middle[cdd3c0f25a03279b]::ty::context::tls::with_opt::::{closure#0}, !>::{closure#0}
15: 0x7bcdbcae08fb - rustc_middle[cdd3c0f25a03279b]::ty::context::tls::with_context_opt::::{closure#0}, !>::{closure#0}, !>
16: 0x7bcdbbb43187 - rustc_middle[cdd3c0f25a03279b]::util::bug::span_bug_fmt::
17: 0x7bcdbe861d30 - >::check_safe_pointer
18: 0x7bcdbe867d0b - as rustc_const_eval[1e343bddbce1c9f9]::interpret::visitor::ValueVisitor>::visit_value
19: 0x7bcdbbbcf850 - rustc_const_eval[1e343bddbce1c9f9]::const_eval::eval_queries::eval_to_allocation_raw_provider
20: 0x7bcdbe84a876 - rustc_query_impl[59345be8fa34e1e5]::plumbing::__rust_begin_short_backtrace::>
21: 0x7bcdbe84a092 - rustc_query_system[af0e7f2cb0d9ade9]::query::plumbing::try_execute_query::, rustc_middle[cdd3c0f25a03279b]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[59345be8fa34e1e5]::plumbing::QueryCtxt, false>
22: 0x7bcdbe849c6f - rustc_query_impl[59345be8fa34e1e5]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
23: 0x7bcdbe84bad8 - rustc_const_eval[1e343bddbce1c9f9]::const_eval::eval_queries::eval_to_const_value_raw_provider
24: 0x7bcdbe84b8f6 - rustc_query_impl[59345be8fa34e1e5]::plumbing::__rust_begin_short_backtrace::>
25: 0x7bcdbe84a055 - rustc_query_system[af0e7f2cb0d9ade9]::query::plumbing::try_execute_query::, rustc_middle[cdd3c0f25a03279b]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[59345be8fa34e1e5]::plumbing::QueryCtxt, false>
26: 0x7bcdbe849b73 - rustc_query_impl[59345be8fa34e1e5]::query_impl::eval_to_const_value_raw::get_query_non_incr::__rust_end_short_backtrace
27: 0x7bcdbe45467d - ::par_body_owners::::{closure#0}
28: 0x7bcdbe451f06 - rustc_hir_analysis[416db8bc62cc6f14]::check_crate
29: 0x7bcdbe44e845 - rustc_interface[36ae3b7efb67c520]::passes::run_required_analyses
30: 0x7bcdbeef13de - rustc_interface[36ae3b7efb67c520]::passes::analysis
31: 0x7bcdbeef13b1 - rustc_query_impl[59345be8fa34e1e5]::plumbing::__rust_begin_short_backtrace::>
32: 0x7bcdbf072bee - rustc_query_system[af0e7f2cb0d9ade9]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[59345be8fa34e1e5]::plumbing::QueryCtxt, false>
33: 0x7bcdbf07294f - rustc_query_impl[59345be8fa34e1e5]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
34: 0x7bcdbeee98fc - rustc_interface[36ae3b7efb67c520]::interface::run_compiler::, rustc_driver_impl[f105cbeea98b4d25]::run_compiler::{closure#0}>::{closure#1}
35: 0x7bcdbef8d410 - std[a418af8a4b80da9d]::sys::backtrace::__rust_begin_short_backtrace::, rustc_driver_impl[f105cbeea98b4d25]::run_compiler::{closure#0}>::{closure#1}, core[d660f6968a6ca250]::result::Result<(), rustc_span[28d86ad0cd00d34a]::ErrorGuaranteed>>::{closure#0}, core[d660f6968a6ca250]::result::Result<(), rustc_span[28d86ad0cd00d34a]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d660f6968a6ca250]::result::Result<(), rustc_span[28d86ad0cd00d34a]::ErrorGuaranteed>>
36: 0x7bcdbef8da7a - <::spawn_unchecked_, rustc_driver_impl[f105cbeea98b4d25]::run_compiler::{closure#0}>::{closure#1}, core[d660f6968a6ca250]::result::Result<(), rustc_span[28d86ad0cd00d34a]::ErrorGuaranteed>>::{closure#0}, core[d660f6968a6ca250]::result::Result<(), rustc_span[28d86ad0cd00d34a]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d660f6968a6ca250]::result::Result<(), rustc_span[28d86ad0cd00d34a]::ErrorGuaranteed>>::{closure#1} as core[d660f6968a6ca250]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
37: 0x7bcdbef8de6b - std::sys::pal::unix::thread::Thread::new::thread_start::h05af6d35f9d401bc
38: 0x7bcdb9294ac3 - start_thread
at ./nptl/pthread_create.c:442:8
39: 0x7bcdb9326850 - __GI___clone3
at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
40: 0x0 -
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 (4f1be9215 2024-09-14) running on x86_64-unknown-linux-gnu
query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `NULL_BOX`
#1 [eval_to_const_value_raw] simplifying constant for the type system `NULL_BOX`
end of query stack
error: aborting due to 3 previous errors
Some errors have detailed explanations: E0517, E0601.
For more information about an error, try `rustc --explain E0517`.
```