Closed
Description
I was writing some code that uses traits with generic associated types and hit an ICE when adding const generic bounds to a function.
Code
I couldn't easily minimize it much more than this, unfortunately. The bound in question is Equal<{ core::mem::size_of::<T>() }, { core::mem::size_of::<U>() }>: True, and goes away if you remove the TO and FROM functions and definitions in the Tokenize trait. The ICE goes away if you change the left-hand to core::mem::size_of::<T>() as usize instead.
Meta
rustc --version --verbose:
rustc 1.69.0-nightly (2773383a3 2023-02-10)
binary: rustc
commit-hash: 2773383a314a4b8f481ce2bed12c32de794ffbe9
commit-date: 2023-02-10
host: x86_64-unknown-linux-gnu
release: 1.69.0-nightly
LLVM version: 15.0.7
Error output
error: internal compiler error: no errors encountered even though `delay_span_bug` issued
error: internal compiler error: cannot relate constants (Const { ty: fn() -> usize {std::mem::size_of::<_>}, kind: Value(Branch([])) }, Const { ty: fn() -> usize {std::mem::size_of::<_>}, kind: Value(Branch([])) }) of different types: fn() -> usize {std::mem::size_of::<_>} != fn() -> usize {std::mem::size_of::<_>}
|
= note: delayed at 0: <rustc_errors::HandlerInner>::emit_diagnostic
Backtrace
0: <rustc_errors::HandlerInner>::emit_diagnostic
1: <rustc_errors::Handler>::delay_span_bug::<rustc_span::span_encoding::Span, &alloc::string::String>
2: rustc_middle::ty::relate::super_relate_consts::<rustc_infer::infer::equate::Equate>
3: <rustc_infer::infer::InferCtxt>::super_combine_consts::<rustc_infer::infer::equate::Equate>
4: rustc_middle::ty::relate::super_relate_consts::<rustc_infer::infer::equate::Equate>
5: <rustc_infer::infer::InferCtxt>::super_combine_consts::<rustc_infer::infer::equate::Equate>
6: <rustc_infer::infer::InferCtxt>::commit_if_ok::<rustc_infer::infer::InferOk<()>, rustc_middle::ty::error::TypeError, <rustc_infer::infer::at::Trace>::eq<rustc_middle::ty::consts::Const>::{closure#0}>
7: <rustc_infer::infer::at::At>::eq::<rustc_middle::ty::consts::Const>
8: <rustc_trait_selection::traits::fulfill::FulfillProcessor as rustc_data_structures::obligation_forest::ObligationProcessor>::process_obligation
9: <rustc_data_structures::obligation_forest::ObligationForest<rustc_trait_selection::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection::traits::fulfill::FulfillProcessor>
10: <rustc_trait_selection::traits::fulfill::FulfillmentContext as rustc_infer::traits::engine::TraitEngine>::select_where_possible
11: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
12: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_return_expr
13: rustc_hir_typeck::check::check_fn
14: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_closure
15: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
16: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_argument_types
17: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
18: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_argument_types
19: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_call
20: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
21: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_block_with_expected
22: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
23: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_return_expr
24: rustc_hir_typeck::check::check_fn
25: rustc_hir_typeck::typeck
26: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::queries::typeck, rustc_query_impl::plumbing::QueryCtxt>
27: rustc_data_structures::sync::par_for_each_in::<&[rustc_span::def_id::LocalDefId], <rustc_middle::hir::map::Map>::par_body_owners<rustc_hir_typeck::typeck_item_bodies::{closure#0}>::{closure#0}>
28: rustc_hir_typeck::typeck_item_bodies
29: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::queries::typeck_item_bodies, rustc_query_impl::plumbing::QueryCtxt>
30: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::typeck_item_bodies
31: <rustc_session::session::Session>::time::<(), rustc_hir_analysis::check_crate::{closure#7}>
32: rustc_hir_analysis::check_crate
33: rustc_interface::passes::analysis
34: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::queries::analysis, rustc_query_impl::plumbing::QueryCtxt>
35: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
36: <rustc_middle::ty::context::GlobalCtxt>::enter::<rustc_driver_impl::run_compiler::{closure#1}::{closure#2}::{closure#3}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
37: <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#1}::{closure#2}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_errors::ErrorGuaranteed>>
38: rustc_span::with_source_map::<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
39: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
40: std::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
41: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
42: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
at /rustc/2773383a314a4b8f481ce2bed12c32de794ffbe9/library/alloc/src/boxed.rs:1988:9
43: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
at /rustc/2773383a314a4b8f481ce2bed12c32de794ffbe9/library/alloc/src/boxed.rs:1988:9
44: std::sys::unix::thread::Thread::new::thread_start
at /rustc/2773383a314a4b8f481ce2bed12c32de794ffbe9/library/std/src/sys/unix/thread.rs:108:17
45: start_thread
at ./nptl/./nptl/pthread_create.c:442:8
46: clone3
at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81