Closed
Description
Code
use core::mem::{transmute, ManuallyDrop};
// `&mut "literal"` has a type of `&mut &str`, not `&mut str`
const S: &'static mut str = &mut " hello ";
const fn trigger() -> [(); unsafe {
let s = transmute::<(*const u8, usize), &ManuallyDrop<str>>((S.as_ptr(), 3));
0
}] {
[(); 0]
}
Meta
rustc --version --verbose
:
rustc 1.46.0 (04488afe3 2020-08-24)
rustc 1.47.0-beta.2 (84b047bf6 2020-08-28)
rustc 1.48.0-nightly (5099914a1 2020-09-08)
Error output
error: internal compiler error: src/librustc_mir/interpret/place.rs:860:13: type mismatch when copying!
Backtrace
Compiling playground v0.0.1 (/playground)
error[E0764]: mutable references are not allowed in constants
--> src/lib.rs:3:29
|
3 | const S: &'static mut str = &mut " hello ";
| ^^^^^^^^^^^^^^ `&mut` is only allowed in `const fn`
error[E0019]: constant contains unimplemented expression type
--> src/lib.rs:3:29
|
3 | const S: &'static mut str = &mut " hello ";
| ^^^^^^^^^^^^^^
|
= help: add `#![feature(const_mut_refs)]` to the crate attributes to enable
error[E0596]: cannot borrow data in a `&` reference as mutable
--> src/lib.rs:3:29
|
3 | const S: &'static mut str = &mut " hello ";
| ^^^^^^^^^^^^^^ cannot borrow as mutable
error: internal compiler error: src/librustc_mir/interpret/place.rs:860:13: type mismatch when copying!
src: &str,
dest: &mut str
--> src/lib.rs:3:29
|
3 | const S: &'static mut str = &mut " hello ";
| ^^^^^^^^^^^^^^
thread 'rustc' panicked at 'Box<Any>', /rustc/04488afe34512aa4c33566eb16d8c912a3ae04f9/src/libstd/macros.rs:13:23
stack backtrace:
0: backtrace::backtrace::libunwind::trace
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86
1: backtrace::backtrace::trace_unsynchronized
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66
2: std::sys_common::backtrace::_print_fmt
at src/libstd/sys_common/backtrace.rs:78
3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
at src/libstd/sys_common/backtrace.rs:59
4: core::fmt::write
at src/libcore/fmt/mod.rs:1076
5: std::io::Write::write_fmt
at src/libstd/io/mod.rs:1537
6: std::sys_common::backtrace::_print
at src/libstd/sys_common/backtrace.rs:62
7: std::sys_common::backtrace::print
at src/libstd/sys_common/backtrace.rs:49
8: std::panicking::default_hook::{{closure}}
at src/libstd/panicking.rs:198
9: std::panicking::default_hook
at src/libstd/panicking.rs:217
10: rustc_driver::report_ice
11: std::panicking::rust_panic_with_hook
at src/libstd/panicking.rs:530
12: std::panicking::begin_panic
13: rustc_errors::HandlerInner::span_bug
14: rustc_errors::Handler::span_bug
15: rustc_middle::util::bug::opt_span_bug_fmt::{{closure}}
16: rustc_middle::ty::context::tls::with_opt::{{closure}}
17: rustc_middle::ty::context::tls::with_opt
18: rustc_middle::util::bug::opt_span_bug_fmt
19: rustc_middle::util::bug::span_bug_fmt
20: rustc_mir::interpret::place::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::copy_op_no_validate
21: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_rvalue_into_place
22: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::run
23: rustc_mir::const_eval::eval_queries::const_eval_raw_provider
24: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::const_eval_raw>::compute
25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
26: rustc_data_structures::stack::ensure_sufficient_stack
27: rustc_query_system::query::plumbing::get_query_impl
28: rustc_mir::const_eval::eval_queries::const_eval_validated_provider
29: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::const_eval_validated>::compute
30: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
31: rustc_data_structures::stack::ensure_sufficient_stack
32: rustc_query_system::query::plumbing::get_query_impl
33: rustc_mir::const_eval::eval_queries::const_eval_validated_provider
34: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::const_eval_validated>::compute
35: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
36: rustc_data_structures::stack::ensure_sufficient_stack
37: rustc_query_system::query::plumbing::get_query_impl
38: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_global_id
39: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_resolve
40: <rustc_trait_selection::traits::query::normalize::QueryNormalizer as rustc_middle::ty::fold::TypeFolder>::fold_const
41: <rustc_infer::infer::at::At as rustc_trait_selection::traits::query::normalize::AtExt>::normalize
42: rustc_infer::infer::InferCtxtBuilder::enter
43: rustc_traits::normalize_erasing_regions::normalize_generic_arg_after_erasing_regions
44: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::normalize_generic_arg_after_erasing_regions>::compute
45: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
46: rustc_data_structures::stack::ensure_sufficient_stack
47: rustc_query_system::query::plumbing::get_query_impl
48: <rustc_middle::ty::normalize_erasing_regions::NormalizeAfterErasingRegionsFolder as rustc_middle::ty::fold::TypeFolder>::fold_const
49: rustc_middle::ty::normalize_erasing_regions::<impl rustc_middle::ty::context::TyCtxt>::subst_and_normalize_erasing_regions
50: rustc_mir::interpret::operand::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_operand
51: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_rvalue_into_place
52: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::run
53: rustc_mir::const_eval::eval_queries::const_eval_raw_provider
54: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::const_eval_raw>::compute
55: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
56: rustc_data_structures::stack::ensure_sufficient_stack
57: rustc_query_system::query::plumbing::get_query_impl
58: rustc_mir::const_eval::eval_queries::const_eval_validated_provider
59: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::const_eval_validated>::compute
60: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
61: rustc_data_structures::stack::ensure_sufficient_stack
62: rustc_query_system::query::plumbing::get_query_impl
63: rustc_mir::const_eval::eval_queries::const_eval_validated_provider
64: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::const_eval_validated>::compute
65: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
66: rustc_data_structures::stack::ensure_sufficient_stack
67: rustc_query_system::query::plumbing::get_query_impl
68: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_global_id
69: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_resolve
70: <rustc_trait_selection::traits::project::AssocTypeNormalizer as rustc_middle::ty::fold::TypeFolder>::fold_const
71: <rustc_trait_selection::traits::project::AssocTypeNormalizer as rustc_middle::ty::fold::TypeFolder>::fold_ty
72: rustc_middle::ty::fold::TypeFoldable::fold_with
73: rustc_trait_selection::traits::project::AssocTypeNormalizer::fold
74: rustc_trait_selection::traits::project::normalize
75: <rustc_infer::infer::InferCtxt as rustc_trait_selection::infer::InferCtxtExt>::partially_normalize_associated_types_in
76: rustc_typeck::check::FnCtxt::normalize_associated_types_in
77: rustc_infer::infer::InferCtxtBuilder::enter
78: rustc_typeck::check::wfcheck::check_item_well_formed
79: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::check_item_well_formed>::compute
80: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
81: rustc_data_structures::stack::ensure_sufficient_stack
82: rustc_query_system::query::plumbing::get_query_impl
83: rustc_query_system::query::plumbing::ensure_query_impl
84: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::itemlikevisit::ParItemLikeVisitor>::visit_item
85: rustc_data_structures::sync::par_for_each_in
86: rustc_hir::hir::Crate::par_visit_all_item_likes
87: rustc_session::session::Session::track_errors
88: rustc_typeck::check_crate
89: rustc_interface::passes::analysis
90: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute
91: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
92: rustc_query_system::query::plumbing::get_query_impl
93: rustc_middle::ty::context::tls::enter_global
94: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
95: rustc_span::with_source_map
96: rustc_interface::interface::create_compiler_and_run
97: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.46.0 (04488afe3 2020-08-24) running on x86_64-unknown-linux-gnu
note: compiler flags: -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2 --crate-type lib
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
#0 [const_eval_raw] const-evaluating `S`
#1 [const_eval_validated] const-evaluating + checking `S`
#2 [const_eval_validated] const-evaluating + checking `S`
#3 [normalize_generic_arg_after_erasing_regions] normalizing `S`
#4 [const_eval_raw] const-evaluating `trigger::{{constant}}#0`
#5 [const_eval_validated] const-evaluating + checking `trigger::{{constant}}#0`
#6 [const_eval_validated] const-evaluating + checking `trigger::{{constant}}#0`
#7 [check_item_well_formed] checking that `trigger` is well-formed
#8 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 4 previous errors
Metadata
Metadata
Assignees
Labels
Area: Constant evaluation, covers all const contexts (static, const fn, ...)Category: This is a bug.Call for participation: An issue has been fixed and does not reproduce, but no test has been added.Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️Relevant to the compiler team, which will review and decide on the PR/issue.ICE tracked in rust-lang/glacier.