Closed
Description
Hello! I've tried to search for this error in the open issues but couldn't find anything, sorry if I've missed something. Below is a minimal example of the issue — it is to do with using an explicit &'a lifetime in the call to mem::size_of. If I replace the call with mem::size_of::<&i32>() (notice & rather than &'a), it compiles without any errors.
Code
use std::mem;
struct Foo(Box<[u8]>);
impl<'a> From<&'a i32> for Foo {
fn from(value: &'a i32) -> Self {
let value = unsafe { mem::transmute::<_, [u8; mem::size_of::<&'a i32>()]>(value) };
Self(Box::new(value))
}
}Meta
rustc --version --verbose:
rustc 1.46.0 (04488afe3 2020-08-24)
binary: rustc
commit-hash: 04488afe34512aa4c33566eb16d8c912a3ae04f9
commit-date: 2020-08-24
host: x86_64-apple-darwin
release: 1.46.0
LLVM version: 10.0
Error output
error: internal compiler error: src/librustc_mir/borrow_check/universal_regions.rs:767:36: cannot convert `ReEarlyBound(0, 'a)` to a region vid
thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:916:9
note: run with `RUST_BACKTRACE=1` environment variable to display a 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-apple-darwin
error: aborting due to previous error
Backtrace
error: internal compiler error: src/librustc_mir/borrow_check/universal_regions.rs:767:36: cannot convert `ReEarlyBound(0, 'a)` to a region vid
thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:916:9
stack backtrace:
0: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
1: core::fmt::write
2: std::io::Write::write_fmt
3: std::panicking::default_hook::{{closure}}
4: std::panicking::default_hook
5: rustc_driver::report_ice
6: std::panicking::rust_panic_with_hook
7: std::panicking::begin_panic
8: rustc_errors::HandlerInner::bug
9: rustc_errors::Handler::bug
10: rustc_middle::util::bug::opt_span_bug_fmt::{{closure}}
11: rustc_middle::ty::context::tls::with_opt::{{closure}}
12: rustc_middle::ty::context::tls::with_opt
13: rustc_middle::util::bug::opt_span_bug_fmt
14: rustc_middle::util::bug::bug_fmt
15: rustc_mir::borrow_check::universal_regions::UniversalRegionIndices::to_region_vid::{{closure}}
16: rustc_mir::borrow_check::universal_regions::UniversalRegionIndices::to_region_vid
17: rustc_mir::borrow_check::type_check::constraint_conversion::ConstraintConversion::convert_all
18: rustc_mir::borrow_check::type_check::type_check
19: rustc_mir::borrow_check::nll::compute_regions
20: rustc_mir::borrow_check::do_mir_borrowck
21: rustc_infer::infer::InferCtxtBuilder::enter
22: rustc_mir::borrow_check::mir_borrowck
23: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::mir_borrowck>::compute
24: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
25: rustc_data_structures::stack::ensure_sufficient_stack
26: rustc_query_system::query::plumbing::get_query_impl
27: rustc_query_system::query::plumbing::ensure_query_impl
28: rustc_mir::transform::mir_drops_elaborated_and_const_checked
29: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::mir_drops_elaborated_and_const_checked>::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::transform::optimized_mir
34: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::optimized_mir>::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_mir::interpret::eval_context::InterpCx<M>::load_mir
39: rustc_mir::const_eval::eval_queries::const_eval_raw_provider
40: 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
41: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
42: rustc_data_structures::stack::ensure_sufficient_stack
43: rustc_query_system::query::plumbing::get_query_impl
44: rustc_mir::const_eval::eval_queries::const_eval_validated_provider
45: 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
46: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
47: rustc_data_structures::stack::ensure_sufficient_stack
48: rustc_query_system::query::plumbing::get_query_impl
49: rustc_mir::const_eval::eval_queries::const_eval_validated_provider
50: 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
51: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
52: rustc_data_structures::stack::ensure_sufficient_stack
53: rustc_query_system::query::plumbing::get_query_impl
54: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_global_id
55: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_resolve
56: <rustc_trait_selection::traits::project::AssocTypeNormalizer as rustc_middle::ty::fold::TypeFolder>::fold_const
57: <rustc_trait_selection::traits::project::AssocTypeNormalizer as rustc_middle::ty::fold::TypeFolder>::fold_ty
58: rustc_data_structures::stack::ensure_sufficient_stack
59: rustc_trait_selection::traits::project::normalize
60: <rustc_infer::infer::InferCtxt as rustc_trait_selection::infer::InferCtxtExt>::partially_normalize_associated_types_in
61: <rustc_typeck::check::FnCtxt as rustc_typeck::astconv::AstConv>::normalize_ty
62: <dyn rustc_typeck::astconv::AstConv>::ast_ty_to_ty
63: <dyn rustc_typeck::astconv::AstConv>::create_substs_for_generic_args
64: rustc_typeck::check::FnCtxt::instantiate_value_path
65: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
66: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation
67: rustc_typeck::check::callee::<impl rustc_typeck::check::FnCtxt>::check_call
68: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
69: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation
70: rustc_typeck::check::FnCtxt::check_block_with_expected
71: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
72: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation
73: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_coercable_to_type
74: rustc_typeck::check::FnCtxt::check_decl_local
75: rustc_typeck::check::FnCtxt::check_stmt
76: rustc_typeck::check::FnCtxt::check_block_with_expected
77: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
78: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation
79: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_return_expr
80: rustc_typeck::check::check_fn
81: rustc_infer::infer::InferCtxtBuilder::enter
82: rustc_typeck::check::typeck_tables_of
83: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::typeck_tables_of>::compute
84: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
85: rustc_data_structures::stack::ensure_sufficient_stack
86: rustc_query_system::query::plumbing::get_query_impl
87: rustc_query_system::query::plumbing::ensure_query_impl
88: rustc_typeck::check::typeck_item_bodies
89: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::typeck_item_bodies>::compute
90: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
91: rustc_data_structures::stack::ensure_sufficient_stack
92: rustc_query_system::query::plumbing::get_query_impl
93: rustc_typeck::check_crate
94: rustc_interface::passes::analysis
95: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute
96: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
97: rustc_query_system::query::plumbing::get_query_impl
98: rustc_middle::ty::context::tls::enter_global
99: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
100: rustc_span::with_source_map
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-apple-darwin
query stack during panic:
#0 [mir_borrowck] borrow-checking `<Foo as std::convert::From<&'a i32>>::from::{{constant}}#0`
#1 [mir_drops_elaborated_and_const_checked] elaborating drops for `<Foo as std::convert::From<&'a i32>>::from::{{constant}}#0`
#2 [optimized_mir] optimizing MIR for `<Foo as std::convert::From<&'a i32>>::from::{{constant}}#0`
#3 [const_eval_raw] const-evaluating `<Foo as std::convert::From<&'a i32>>::from::{{constant}}#0`
#4 [const_eval_validated] const-evaluating + checking `<Foo as std::convert::From<&'a i32>>::from::{{constant}}#0`
#5 [const_eval_validated] const-evaluating + checking `<Foo as std::convert::From<&'a i32>>::from::{{constant}}#0`
#6 [typeck_tables_of] type-checking `<Foo as std::convert::From<&'a i32>>::from`
#7 [typeck_item_bodies] type-checking all item bodies
#8 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error