Closed
Description
Code
You can repro with RUSTFLAGS="-Zunpretty=mir" MIRIFLAGS="-Zmir-opt-level=3" cargo miri run
// This test checks that calling `mem::{uninitialized,zeroed}` with certain types results
// in a lint.
use std::mem::{self};
struct Wrap<T> { wrapped: T }
#[allow(unused)]
fn generic<T: 'static>() {
unsafe {
let _val: Wrap<&'static T> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
}
}
fn main() {}Meta
rustc --version --verbose:
rustc 1.69.0-nightly (20081880a 2023-02-13)
binary: rustc
commit-hash: 20081880ad2a98bbc8c8293f96c5b284d1584d86
commit-date: 2023-02-13
host: x86_64-unknown-linux-gnu
release: 1.69.0-nightly
LLVM version: 15.0.7
Error output
warning: use of deprecated function `std::mem::uninitialized`: use `mem::MaybeUninit` instead
--> src/main.rs:10:43
|
10 | let _val: Wrap<&'static T> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
| ^^^^^^^^^^^^^
|
= note: `#[warn(deprecated)]` on by default
warning: field `wrapped` is never read
--> src/main.rs:5:18
|
5 | struct Wrap<T> { wrapped: T }
| ---- ^^^^^^^
| |
| field in this struct
|
= note: `#[warn(dead_code)]` on by default
warning: the type `Wrap<&T>` does not permit being left uninitialized
--> src/main.rs:10:38
|
10 | let _val: Wrap<&'static T> = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
| ^^^^^^^^^^^^^^^^^^^^
| |
| this code causes undefined behavior when executed
| help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
|
= note: `Wrap<&T>` must be non-null
note: because references must be non-null (in this struct field)
--> src/main.rs:5:18
|
5 | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
= note: `#[warn(invalid_value)]` on by default
Backtrace
thread 'rustc' panicked at 'need to be able to compute layouts: Unknown(T)', compiler/rustc_const_eval/src/util/might_permit_raw_init.rs:111:48
stack backtrace:
0: 0x7febf276a9ea - std::backtrace_rs::backtrace::libunwind::trace::h599c8a609f9333f9
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
1: 0x7febf276a9ea - std::backtrace_rs::backtrace::trace_unsynchronized::hd98c4236d5e12dd3
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
2: 0x7febf276a9ea - std::sys_common::backtrace::_print_fmt::h5e56057600010abc
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/sys_common/backtrace.rs:65:5
3: 0x7febf276a9ea - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h6c880a29175ff5a3
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/sys_common/backtrace.rs:44:22
4: 0x7febf27caafe - core::fmt::write::hfc0242af538b8a46
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/core/src/fmt/mod.rs:1232:17
5: 0x7febf275b005 - std::io::Write::write_fmt::h01aa30c6b6ac7c12
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/io/mod.rs:1684:15
6: 0x7febf276a7b5 - std::sys_common::backtrace::_print::hffab19929157fc64
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/sys_common/backtrace.rs:47:5
7: 0x7febf276a7b5 - std::sys_common::backtrace::print::hcc10add6529763f5
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/sys_common/backtrace.rs:34:9
8: 0x7febf276d54f - std::panicking::default_hook::{{closure}}::h7b790581a0467591
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/panicking.rs:267:22
9: 0x7febf276d28b - std::panicking::default_hook::hea529077c0649ab7
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/panicking.rs:286:9
10: 0x7febf5adcca4 - <rustc_driver_impl[25fd4ad55bd4d290]::DEFAULT_HOOK::{closure#0}::{closure#0} as core[b6202784567cb4e4]::ops::function::FnOnce<(&core[b6202784567cb4e4]::panic::panic_info::PanicInfo,)>>::call_once::{shim:vtable#0}
11: 0x7febf276dd8a - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h9025e888b11b840d
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/alloc/src/boxed.rs:2002:9
12: 0x7febf276dd8a - std::panicking::rust_panic_with_hook::hbf88635db69aa1e9
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/panicking.rs:692:13
13: 0x7febf276db09 - std::panicking::begin_panic_handler::{{closure}}::h0a5dea2fedd0d5a5
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/panicking.rs:579:13
14: 0x7febf276ae8c - std::sys_common::backtrace::__rust_end_short_backtrace::h2507953ca43dc350
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/sys_common/backtrace.rs:137:18
15: 0x7febf276d812 - rust_begin_unwind
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/panicking.rs:575:5
16: 0x7febf27c74a3 - core::panicking::panic_fmt::hf2288fbc08000d27
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/core/src/panicking.rs:64:14
17: 0x7febf27c7a33 - core::result::unwrap_failed::h949aaa38a1828029
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/core/src/result.rs:1790:5
18: 0x7febf519ebb1 - rustc_const_eval[344787e6075ccab3]::util::might_permit_raw_init::might_permit_raw_init_lax
19: 0x7febf519e2ee - rustc_const_eval[344787e6075ccab3]::util::might_permit_raw_init::might_permit_raw_init_lax
20: 0x7febf519dfb9 - rustc_const_eval[344787e6075ccab3]::util::might_permit_raw_init::might_permit_raw_init
21: 0x7febf51fa047 - <rustc_query_system[6e05d7961ccd4849]::dep_graph::graph::DepGraph<rustc_middle[26406bea1d07e151]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[26406bea1d07e151]::ty::context::TyCtxt, rustc_middle[26406bea1d07e151]::ty::ParamEnvAnd<rustc_target[88529097bdb44244]::abi::TyAndLayout<rustc_middle[26406bea1d07e151]::ty::Ty>>, bool>
22: 0x7febf63882d9 - rustc_query_system[6e05d7961ccd4849]::query::plumbing::try_execute_query::<rustc_query_impl[38ddc62a235656bd]::queries::permits_uninit_init, rustc_query_impl[38ddc62a235656bd]::plumbing::QueryCtxt>
23: 0x7febf63ad825 - rustc_query_system[6e05d7961ccd4849]::query::plumbing::get_query::<rustc_query_impl[38ddc62a235656bd]::queries::permits_uninit_init, rustc_query_impl[38ddc62a235656bd]::plumbing::QueryCtxt, rustc_middle[26406bea1d07e151]::dep_graph::dep_node::DepKind>
24: 0x7febf642aa67 - <rustc_query_impl[38ddc62a235656bd]::Queries as rustc_middle[26406bea1d07e151]::ty::query::QueryEngine>::permits_uninit_init
25: 0x7febf61b9f6e - rustc_mir_transform[d56b548caf7a8cfa]::instcombine::intrinsic_assert_panics::mem_uninitialized_valid_predicate
26: 0x7febf4f7d8a6 - <rustc_mir_transform[d56b548caf7a8cfa]::instcombine::InstCombine as rustc_middle[26406bea1d07e151]::mir::MirPass>::run_pass
27: 0x7febf41a1fe8 - rustc_mir_transform[d56b548caf7a8cfa]::optimized_mir
28: 0x7febf4198ff6 - <rustc_query_system[6e05d7961ccd4849]::dep_graph::graph::DepGraph<rustc_middle[26406bea1d07e151]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[26406bea1d07e151]::ty::context::TyCtxt, rustc_span[f166845bd5138698]::def_id::DefId, &rustc_middle[26406bea1d07e151]::mir::Body>
29: 0x7febf413771d - rustc_query_system[6e05d7961ccd4849]::query::plumbing::try_execute_query::<rustc_query_impl[38ddc62a235656bd]::queries::optimized_mir, rustc_query_impl[38ddc62a235656bd]::plumbing::QueryCtxt>
30: 0x7febf4135484 - <rustc_middle[26406bea1d07e151]::ty::context::TyCtxt>::instance_mir
31: 0x7febf5feda35 - rustc_middle[26406bea1d07e151]::mir::pretty::write_mir_pretty
32: 0x7febf5ab4882 - rustc_driver_impl[25fd4ad55bd4d290]::pretty::print_after_hir_lowering
33: 0x7febf5aa02cb - <rustc_middle[26406bea1d07e151]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[25fd4ad55bd4d290]::run_compiler::{closure#1}::{closure#2}::{closure#1}, core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>>
34: 0x7febf4d0aa30 - <rustc_interface[cf329bccbcde2f18]::interface::Compiler>::enter::<rustc_driver_impl[25fd4ad55bd4d290]::run_compiler::{closure#1}::{closure#2}, core[b6202784567cb4e4]::result::Result<core[b6202784567cb4e4]::option::Option<rustc_interface[cf329bccbcde2f18]::queries::Linker>, rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>>
35: 0x7febf4d058c4 - rustc_span[f166845bd5138698]::with_source_map::<core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>, rustc_interface[cf329bccbcde2f18]::interface::run_compiler<core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>, rustc_driver_impl[25fd4ad55bd4d290]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
36: 0x7febf4d053d4 - <scoped_tls[9115c50d9b00df7e]::ScopedKey<rustc_span[f166845bd5138698]::SessionGlobals>>::set::<rustc_interface[cf329bccbcde2f18]::interface::run_compiler<core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>, rustc_driver_impl[25fd4ad55bd4d290]::run_compiler::{closure#1}>::{closure#0}, core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>>
37: 0x7febf4d04ad2 - std[b5e4c008489c853a]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[cf329bccbcde2f18]::util::run_in_thread_pool_with_globals<rustc_interface[cf329bccbcde2f18]::interface::run_compiler<core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>, rustc_driver_impl[25fd4ad55bd4d290]::run_compiler::{closure#1}>::{closure#0}, core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>>
38: 0x7febf5371eac - <<std[b5e4c008489c853a]::thread::Builder>::spawn_unchecked_<rustc_interface[cf329bccbcde2f18]::util::run_in_thread_pool_with_globals<rustc_interface[cf329bccbcde2f18]::interface::run_compiler<core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>, rustc_driver_impl[25fd4ad55bd4d290]::run_compiler::{closure#1}>::{closure#0}, core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b6202784567cb4e4]::result::Result<(), rustc_errors[51cf6c1aaeeb3d69]::ErrorGuaranteed>>::{closure#1} as core[b6202784567cb4e4]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
39: 0x7febf2777d23 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h11a55f6f3d84245d
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/alloc/src/boxed.rs:1988:9
40: 0x7febf2777d23 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd367d709d06ebfbd
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/alloc/src/boxed.rs:1988:9
41: 0x7febf2777d23 - std::sys::unix::thread::Thread::new::thread_start::h340e26124c1b592b
at /rustc/20081880ad2a98bbc8c8293f96c5b284d1584d86/library/std/src/sys/unix/thread.rs:108:17
42: 0x7febf24208fd - <unknown>
43: 0x7febf24a2d20 - <unknown>
44: 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 1.69.0-nightly (20081880a 2023-02-13) running on x86_64-unknown-linux-gnu
note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C incremental=[REDACTED] -Z unpretty=mir -Z mir-opt-level=3
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
#0 [permits_uninit_init] checking to see if `Wrap<&T>` permits being left uninit
#1 [optimized_mir] optimizing MIR for `generic`
end of query stack
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