Add field representing types #146307

BennoLossin · 2025-09-07T19:34:24Z

Add Field Representing Types (FRTs)

This PR implements the first step of the field projection lang experiment (Tracking Issue: #145383). Field representing types (FRTs) are a new kind of type. They can be named through the use of the field_of! macro that uses the same syntax as the offset_of! macro. They natively implement the Field trait that's also added in this PR. It exposes information about the field such as the type of the field, the type of the base (i.e. the type that contains the field) and the offset within that base type.

This PR was created in collaboration with @dingxiangfei2009, it wouldn't have been possible without him, so huge thanks for mentoring me!

I updated my library solution for field projections to use the FRTs from core instead of creating my own using the hash of the name of the field. See the Rust-for-Linux/field-projection lang-experiment branch.

API added to `core::field`

pub unsafe trait Field {
    type Base;
    
    type Type;

    const OFFSET: usize;
}

pub macro field_of($Container:ty, $($fields:expr)+ $(,)?);

Explanation of Field Representing Types (FRTs)

FRTs are used for compile-time & trait-level reflection for fields of structs & tuples. Each struct & tuple has a unique compiler-generated type nameable through the field_of! macro (using the same syntax as offset_of!). This type natively contains information about the field such as the outermost container, type of the field and its offset. Users may implement additional traits on these types in order to record custom information (for example a crate may define a PinnableField trait that records whether the field is structurally pinned).

They are the foundation of field projections, a general operation that's generic over the fields of a struct. This genericism needs to be expressible in the trait system. FRTs make this possible, since an operation generic over fields can just be a function with a generic parameter F: Field.

FRTs should act as though they were defined as enum MyStruct_my_field<StructGenerics> {} next to the struct. So it should be local to the crate defining the struct so that one can implement any trait for the FRT. The Field traits should be implemented by the compiler & populated with correct information (unsafe code needs to be able to rely on them being correct).

Implementation Details

Reuse offset_of! type checking machinery in the FnCtxt case,
- Create a new type called FieldPath for using them in both field_of! and offset_of!,
- Add lower_field_path to HirTyLowerer,
Use an intrinsic to add the offset information into the associated OFFSET constant of the UnalignedField trait,

Decisions

During the development several desirable properties of FRTs were discovered. Either due to simplifying the implementation or because of language design reasons. These decisions are:

FRTs are uninhabited and have the same layout as !
- They only contain type information via the [Unaligned]Field traits, so no need to make them useful as values.
- This simplifies const-eval.
- They are thus also Freeze
FRTs are considered local by the orphan check if and only if:
- The outer-most container is a local struct,
- All intermediate container types that are structs must be local (we don't consider the type of the field to be an intermediate base)
So field_of!(Foo, bar.baz) is local if Foo and Bar are local (Baz is allowed to be foreign). Except for tuples, fundamental types are not handled specially. Tuples are allowed as intermediate bases, as long as the first one isn't a tuple. So field_of!(Foo, bar.0.baz) is considered local if Foo is local & bar has type (Bar0, Bar1, ..., BarN) with Bar0 also being local.

The reasoning for these two rules is the following: we don't want to allow foreign crates control over FRTs, since they will often encode field invariants (such as the offset in the UnalignedField case, or that the field is aligned (Field)).

Tuples are an exception to this, but only if the user controls the outer-most container.

In the future, the first rule could be lifted to:
- local structs are valid outer-most containers,
- tuples where every type is a valid outer-most container are also valid outer-most containers.
This would allow users to implement traits on field_of!((LocalTy, LocalTy), 0). But still prevent field_of!((usize, usize), 0).
traits may be implemented for FRTs in the usual way (so if the FRT or the trait is local). There is an exception:
- Drop: since FRTs are uninhabited, having a Drop impl doesn't really make sense. It also would have required duplicating a lot of logic from ADTs and as such it simplified the implementation.
The Field trait is not user-implementable
- this also can be lifted in the future, but for now only FRTs will implement it.

TODOs

There are several FIXME(field_projections) scattered around the code. These are either because I & Ding didn't 100% know what to do in that case. Note that not all are comments, some are also contained as bug!("FIXME(field_projections): ...").

symbol mangling for FTRs.
- compiler/rustc_symbol_mangling/src/v0.rs
- compiler/rustc_symbol_mangling/src/export.rs
- compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/transform.rs
- compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs
rustdoc support for FTRs
- src/librustdoc/passes/collect_intra_doc_links.rs
- src/librustdoc/json/conversions.rs
- src/librustdoc/clean/mod.rs
check that FRTs support tuples, unions and structs
investigate how complex enum support would be
decided against enum support in this PR
what about DSTs? can we really support the OFFSET constant for those, or do we need different traits?
decided against ?Sized types in this PR

rustbot · 2025-09-07T19:34:30Z

r? @lcnr

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rustbot · 2025-09-08T19:53:28Z

changes to the core type system

cc @compiler-errors, @lcnr

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred in diagnostic error codes

cc @GuillaumeGomez

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

Some changes occurred in compiler/rustc_sanitizers

cc @rcvalle

HIR ty lowering was modified

cc @fmease

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

Some changes occurred in exhaustiveness checking

cc @Nadrieril

This PR changes MIR

cc @oli-obk, @RalfJung, @JakobDegen, @vakaras

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

This PR changes rustc_public

cc @oli-obk, @celinval, @ouz-a

Some changes occurred in src/tools/rustfmt

cc @rust-lang/rustfmt

Some changes occurred to the intrinsics. Make sure the CTFE / Miri interpreter
gets adapted for the changes, if necessary.

cc @rust-lang/miri, @RalfJung, @oli-obk, @lcnr

compiler/rustc_const_eval/src/interpret/intrinsics.rs

library/core/src/intrinsics/mod.rs

library/core/src/field.rs

BennoLossin

There are some changes to symbol mangling & constant names that I'm not sure how they resulted from my changes. Anybody has any idea?

View changes since this review

tests/ui/symbol-names/basic.legacy.stderr

tests/ui/symbol-names/issue-60925.legacy.stderr

tests/debuginfo/function-names.rs

rustbot · 2025-09-09T10:46:41Z

Some changes occurred to constck

cc @fee1-dead

rustbot · 2025-09-09T12:29:53Z

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

RalfJung

Could you ensure you have a test that is generic over the field and that queries the offset? That would hit all these points I just mentioned here (or at least some of them), and anyway seems like a very non-trivial case to test.

Or... wait the intrinsic is only used to define that one associated const? I don't know exactly when and how we normalize those but it may be that we indeed never see that MIR in its generic form then...

The test may have to invoke the intrinsic directly to trigger the case I am thinking of.

View changes since this review

compiler/rustc_const_eval/src/interpret/operator.rs

compiler/rustc_mir_transform/src/gvn.rs

compiler/rustc_mir_transform/src/known_panics_lint.rs

compiler/rustc_mir_transform/src/promote_consts.rs

compiler/rustc_mir_transform/src/validate.rs

BennoLossin

So I met with Xiang and we resolved most of my todos. I converted the rest to fixme; the ones highlighted here are the most questionable ones.

I still plan to add more (ui) tests, but am very open to suggestions as I am lacking creativity there (or rather, I'm missing the forest for the trees, so some help in that regard would be great).

@rustbot ready

View changes since this review

BennoLossin · 2026-01-16T01:05:41Z

compiler/rustc_middle/src/ty/context.rs

+                        // FIXME(FRTs): use correct error number
+                        E0001,


Which number should I use here (and in the other places in this function)?

BennoLossin · 2026-01-16T01:05:58Z

compiler/rustc_middle/src/ty/structural_impls.rs

+            // FIXME(FRTs): add FieldId to the visitor infrastructure if we need to visit it.
+            ty::FRT(ty, _field) => ty.visit_with(visitor),


Probably don't need this, right?

BennoLossin · 2026-01-16T01:06:37Z

compiler/rustc_type_ir/src/fast_reject.rs

+    /// Field representing type.
+    // FIXME(FRTs): should we have a `Option<DefId>` here that gets filled with the Adt's DefId?
+    FRT,


I don't think we need this, but I also don't know what SimplifiedType is used for...

BennoLossin · 2026-01-16T01:07:10Z

compiler/rustc_middle/src/ty/structural_impls.rs

            }
            ty::Alias(kind, data) => ty::Alias(kind, data.try_fold_with(folder)?),
            ty::Pat(ty, pat) => ty::Pat(ty.try_fold_with(folder)?, pat.try_fold_with(folder)?),
+            ty::FRT(ty, field) => *field.resolve(folder.cx(), ty.try_fold_with(folder)?).kind(),


This is essentially to normalize the FRT and it seems to work, at least in simple tests. Let me know if this is how it's intended to work.

BennoLossin · 2026-01-16T12:44:23Z

tests/ui/field_representing_types/bad-next.rs

+fn fails2<T: Constraint>() {
+    let _: field_of!(<<T as WithAssoc>::Assoc as Special>::Assoc, field);
+    // last time I checked this, this line above produced an ICE due to a `delay_bug`
+}


@lcnr here is a very weird case that fails with a delayed span bug with the next solver. Here is the example alone (the delayed span won't get triggered in the test due to the error above & below):

#![feature(field_projections)] #![expect(incomplete_features, dead_code)] use std::field::field_of; struct Struct { field: u32, } trait WithAssoc { type Assoc: Special; } trait Special { type Assoc; } trait Constraint: WithAssoc<Assoc = Struct> {} impl Special for Struct { type Assoc = Self; } fn fails2<T: Constraint>() { let _: field_of!(<<T as WithAssoc>::Assoc as Special>::Assoc, field); }

ICE Log

note: no errors encountered even though delayed bugs were created note: those delayed bugs will now be shown as internal compiler errors error: internal compiler error: error performing operation: query type op --> demo.rs:27:12 | 27 | let _: field_of!(<<T as WithAssoc>::Assoc as Special>::Assoc, field); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | note: delayed at .../compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs:95:25 0: emit_diagnostic at ./compiler/rustc_errors/src/lib.rs:1576:41 1: emit_diagnostic at ./compiler/rustc_errors/src/lib.rs:1136:33 2: emit_producing_error_guaranteed<rustc_span::ErrorGuaranteed> at ./compiler/rustc_errors/src/diagnostic.rs:1398:29 3: span_delayed_bug<rustc_span::span_encoding::Span, alloc::string::String> at ./compiler/rustc_errors/src/lib.rs:1378:82 4: {closure#0}<rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::AscribeUserType>, (), rustc_trait_selection::traits::query::type_op::{impl#0}::fully_perform::{closure_env#0}<rustc_middle::traits::query::type_op::AscribeUserType>> at ./compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs:95:25 5: map_err<(), rustc_type_ir::solve::NoSolution, rustc_span::ErrorGuaranteed, rustc_trait_selection::traits::query::type_op::custom::scrape_region_constraints::{closure#0}::{closure_env#0}<rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::AscribeUserType>, (), rustc_trait_selection::traits::query::type_op::{impl#0}::fully_perform::{closure_env#0}<rustc_middle::traits::query::type_op::AscribeUserType>>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/result.rs:968:27 6: {closure#0}<rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::AscribeUserType>, (), rustc_trait_selection::traits::query::type_op::{impl#0}::fully_perform::{closure_env#0}<rustc_middle::traits::query::type_op::AscribeUserType>> at ./compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs:94:30 7: commit_if_ok<(), rustc_span::ErrorGuaranteed, rustc_trait_selection::traits::query::type_op::custom::scrape_region_constraints::{closure_env#0}<rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::AscribeUserType>, (), rustc_trait_selection::traits::query::type_op::{impl#0}::fully_perform::{closure_env#0}<rustc_middle::traits::query::type_op::AscribeUserType>>> at ./compiler/rustc_infer/src/infer/snapshot/mod.rs:86:17 8: scrape_region_constraints<rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::AscribeUserType>, (), rustc_trait_selection::traits::query::type_op::{impl#0}::fully_perform::{closure_env#0}<rustc_middle::traits::query::type_op::AscribeUserType>> at ./compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs:92:23 9: fully_perform<rustc_middle::traits::query::type_op::AscribeUserType> at ./compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs:156:23 10: fully_perform_op_raw<(), rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::AscribeUserType>> at ./compiler/rustc_borrowck/src/type_check/canonical.rs:42:12 11: fully_perform_op<(), rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::AscribeUserType>> at ./compiler/rustc_borrowck/src/type_check/canonical.rs:103:9 12: ascribe_user_type at ./compiler/rustc_borrowck/src/type_check/canonical.rs:318:50 13: check_user_type_annotations at ./compiler/rustc_borrowck/src/type_check/mod.rs:393:18 14: type_check at ./compiler/rustc_borrowck/src/type_check/mod.rs:165:12 15: borrowck_collect_region_constraints at ./compiler/rustc_borrowck/src/lib.rs:354:9 16: do_mir_borrowck at ./compiler/rustc_borrowck/src/root_cx.rs:253:26 17: mir_borrowck at ./compiler/rustc_borrowck/src/lib.rs:135:17 18: {closure#0} at ./compiler/rustc_query_impl/src/plumbing.rs:298:9 19: __rust_begin_short_backtrace<rustc_query_impl::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure_env#0}, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_query_impl/src/plumbing.rs:582:18 20: {closure#2} at ./compiler/rustc_query_impl/src/plumbing.rs:659:25 21: call_once<rustc_query_impl::query_impl::mir_borrowck::dynamic_query::{closure_env#2}, (rustc_middle::ty::context::TyCtxt, rustc_span::def_id::LocalDefId)> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/ops/function.rs:250:5 22: compute<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false> at ./compiler/rustc_query_impl/src/lib.rs:119:9 23: {closure#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:506:72 24: {closure#0}<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:60:9 25: try_with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 8]>>, rustc_middle::query::erase::Erased<[u8; 8]>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/local.rs:513:12 26: with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 8]>>, rustc_middle::query::erase::Erased<[u8; 8]>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/local.rs:477:20 27: enter_context<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:57:9 28: {closure#0}<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ./compiler/rustc_query_impl/src/plumbing.rs:169:13 29: {closure#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:112:9 30: {closure#0}<rustc_middle::ty::context::tls::with_related_context::{closure_env#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 8]>>, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:90:36 31: with_context_opt<rustc_middle::ty::context::tls::with_context::{closure_env#0}<rustc_middle::ty::context::tls::with_related_context::{closure_env#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 8]>>, rustc_middle::query::erase::Erased<[u8; 8]>>, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:79:18 32: with_context<rustc_middle::ty::context::tls::with_related_context::{closure_env#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 8]>>, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:90:5 33: with_related_context<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 8]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:103:5 34: start_query<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ./compiler/rustc_query_impl/src/plumbing.rs:155:9 35: execute_job_non_incr<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:506:22 36: execute_job<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> at ./compiler/rustc_query_system/src/query/plumbing.rs:442:9 37: try_execute_query<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> at ./compiler/rustc_query_system/src/query/plumbing.rs:385:13 38: {closure#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:827:32 39: maybe_grow<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::get_query_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ~/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/stacker-0.1.21/src/lib.rs:57:9 40: ensure_sufficient_stack<rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::query::plumbing::get_query_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ./compiler/rustc_data_structures/src/stack.rs:21:5 41: get_query_non_incr<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:827:5 42: __rust_end_short_backtrace at ./compiler/rustc_query_impl/src/plumbing.rs:635:26 43: query_ensure<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>> at ./compiler/rustc_middle/src/query/inner.rs:51:9 44: mir_borrowck<rustc_span::def_id::LocalDefId> at ./compiler/rustc_middle/src/query/plumbing.rs:173:9 45: {closure#0} at ./compiler/rustc_interface/src/passes.rs:1107:33 46: {closure#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}> at ./compiler/rustc_middle/src/hir/map.rs:339:79 47: {closure#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>> at ./compiler/rustc_data_structures/src/sync/parallel.rs:181:30 48: call_once<(), rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/panic/unwind_safe.rs:274:9 49: do_call<core::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>>>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panicking.rs:581:40 50: catch_unwind<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>>>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panicking.rs:544:19 51: catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>>>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panic.rs:359:14 52: run<(), rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>>> at ./compiler/rustc_data_structures/src/sync/parallel.rs:23:9 53: {closure#1}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>> at ./compiler/rustc_data_structures/src/sync/parallel.rs:181:23 54: for_each<rustc_span::def_id::LocalDefId, rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure_env#1}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/slice/iter/macros.rs:301:21 55: {closure#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>> at ./compiler/rustc_data_structures/src/sync/parallel.rs:180:27 56: parallel_guard<(), rustc_data_structures::sync::parallel::par_for_each_in::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>>> at ./compiler/rustc_data_structures/src/sync/parallel.rs:39:15 57: par_for_each_in<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}>> at ./compiler/rustc_data_structures/src/sync/parallel.rs:175:5 58: par_hir_body_owners<rustc_interface::passes::run_required_analyses::{closure#1}::{closure_env#0}> at ./compiler/rustc_middle/src/hir/map.rs:339:9 59: {closure#1} at ./compiler/rustc_interface/src/passes.rs:1097:13 60: run<(), rustc_interface::passes::run_required_analyses::{closure_env#1}> at ./compiler/rustc_data_structures/src/profiling.rs:844:9 61: time<(), rustc_interface::passes::run_required_analyses::{closure_env#1}> at ./compiler/rustc_session/src/utils.rs:17:50 62: run_required_analyses at ./compiler/rustc_interface/src/passes.rs:1096:10 63: analysis at ./compiler/rustc_interface/src/passes.rs:1144:5 64: {closure#0} at ./compiler/rustc_query_impl/src/plumbing.rs:298:9 65: __rust_begin_short_backtrace<rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2}::{closure_env#0}, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_query_impl/src/plumbing.rs:582:18 66: {closure#2} at ./compiler/rustc_query_impl/src/plumbing.rs:659:25 67: call_once<rustc_query_impl::query_impl::analysis::dynamic_query::{closure_env#2}, (rustc_middle::ty::context::TyCtxt, ())> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/ops/function.rs:250:5 68: compute<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false> at ./compiler/rustc_query_impl/src/lib.rs:119:9 69: {closure#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:506:72 70: {closure#0}<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:60:9 71: try_with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 0]>>, rustc_middle::query::erase::Erased<[u8; 0]>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/local.rs:513:12 72: with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 0]>>, rustc_middle::query::erase::Erased<[u8; 0]>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/local.rs:477:20 73: enter_context<rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:57:9 74: {closure#0}<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ./compiler/rustc_query_impl/src/plumbing.rs:169:13 75: {closure#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:112:9 76: {closure#0}<rustc_middle::ty::context::tls::with_related_context::{closure_env#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 0]>>, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:90:36 77: with_context_opt<rustc_middle::ty::context::tls::with_context::{closure_env#0}<rustc_middle::ty::context::tls::with_related_context::{closure_env#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 0]>>, rustc_middle::query::erase::Erased<[u8; 0]>>, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:79:18 78: with_context<rustc_middle::ty::context::tls::with_related_context::{closure_env#0}<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 0]>>, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:90:5 79: with_related_context<rustc_query_impl::plumbing::{impl#3}::start_query::{closure_env#0}<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>>, rustc_middle::query::erase::Erased<[u8; 0]>> at ./compiler/rustc_middle/src/ty/context/tls.rs:103:5 80: start_query<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::execute_job_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ./compiler/rustc_query_impl/src/plumbing.rs:155:9 81: execute_job_non_incr<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:506:22 82: execute_job<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> at ./compiler/rustc_query_system/src/query/plumbing.rs:442:9 83: try_execute_query<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> at ./compiler/rustc_query_system/src/query/plumbing.rs:385:13 84: {closure#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:827:32 85: maybe_grow<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::get_query_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ~/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/stacker-0.1.21/src/lib.rs:57:9 86: ensure_sufficient_stack<rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::query::plumbing::get_query_non_incr::{closure_env#0}<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt>> at ./compiler/rustc_data_structures/src/stack.rs:21:5 87: get_query_non_incr<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt> at ./compiler/rustc_query_system/src/query/plumbing.rs:827:5 88: __rust_end_short_backtrace at ./compiler/rustc_query_impl/src/plumbing.rs:635:26 89: query_ensure<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>> at ./compiler/rustc_middle/src/query/inner.rs:51:9 90: analysis at ./compiler/rustc_middle/src/query/plumbing.rs:173:9 91: {closure#2} at ./compiler/rustc_driver_impl/src/lib.rs:367:29 92: {closure#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}> at ./compiler/rustc_interface/src/passes.rs:1020:27 93: {closure#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>> at ./compiler/rustc_middle/src/ty/context.rs:1659:37 94: {closure#0}<rustc_middle::ty::context::{impl#20}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>> at ./compiler/rustc_middle/src/ty/context/tls.rs:60:9 95: try_with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_middle::ty::context::{impl#20}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/local.rs:513:12 96: with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_middle::ty::context::{impl#20}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/local.rs:477:20 97: enter_context<rustc_middle::ty::context::{impl#20}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>> at ./compiler/rustc_middle/src/ty/context/tls.rs:57:9 98: enter<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>> at ./compiler/rustc_middle/src/ty/context.rs:1659:9 99: create_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>> at ./compiler/rustc_middle/src/ty/context.rs:1866:13 100: {closure#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}> at ./compiler/rustc_interface/src/passes.rs:987:9 101: call_once<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, (&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy, alloc::alloc::Global>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2})> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/ops/function.rs:250:5 102: call_once<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy, alloc::alloc::Global>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}), dyn core::ops::function::FnOnce<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy, alloc::alloc::Global>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}), Output=core::option::Option<rustc_interface::queries::Linker>>, alloc::alloc::Global> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/alloc/src/boxed.rs:2206:9 103: create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}> at ./compiler/rustc_interface/src/passes.rs:1028:5 104: {closure#0} at ./compiler/rustc_driver_impl/src/lib.rs:340:22 105: {closure#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}> at ./compiler/rustc_interface/src/interface.rs:552:80 106: call_once<(), rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/panic/unwind_safe.rs:274:9 107: do_call<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panicking.rs:581:40 108: catch_unwind<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panicking.rs:544:19 109: catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panic.rs:359:14 110: {closure#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}> at ./compiler/rustc_interface/src/interface.rs:552:23 111: {closure#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()> at ./compiler/rustc_interface/src/util.rs:209:17 112: {closure#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()> at ./compiler/rustc_interface/src/util.rs:163:24 113: set<rustc_span::SessionGlobals, rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()> at ~/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/scoped-tls-1.0.1/src/lib.rs:137:9 114: create_session_globals_then<(), rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>> at ./compiler/rustc_span/src/lib.rs:144:21 115: {closure#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()> at ./compiler/rustc_interface/src/util.rs:159:17 116: __rust_begin_short_backtrace<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/sys/backtrace.rs:160:18 117: {closure#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/lifecycle.rs:92:13 118: call_once<(), std::thread::lifecycle::spawn_unchecked::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/panic/unwind_safe.rs:274:9 119: do_call<core::panic::unwind_safe::AssertUnwindSafe<std::thread::lifecycle::spawn_unchecked::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panicking.rs:581:40 120: catch_unwind<(), core::panic::unwind_safe::AssertUnwindSafe<std::thread::lifecycle::spawn_unchecked::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>>> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panicking.rs:544:19 121: catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<std::thread::lifecycle::spawn_unchecked::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/panic.rs:359:14 122: {closure#1}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/thread/lifecycle.rs:90:26 123: call_once<std::thread::lifecycle::spawn_unchecked::{closure_env#1}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>, ()> at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/core/src/ops/function.rs:250:5 124: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/alloc/src/boxed.rs:2206:9 125: std::sys::thread::unix::Thread::new::thread_start at /rustc/1b6e21e163baa0b20f119e17e3871910978a60b6/library/std/src/sys/thread/unix.rs:118:17 126: start_thread 127: __clone3 --> demo.rs:27:12 | 27 | let _: field_of!(<<T as WithAssoc>::Assoc as Special>::Assoc, field); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = note: this error: internal compiler error originates in the macro `field_of` (in Nightly builds, run with -Z macro-backtrace for more info) 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: please attach the file at `.../rustc-ice-2026-01-16T12_40_15-28377.txt` to your bug report note: rustc 1.94.0-dev running on x86_64-unknown-linux-gnu note: compiler flags: --crate-type lib -Z next-solver query stack during panic: end of query stack

Am I missing anything in the code for this to work, or is this a bug in the next solver? 🤔

rustbot assigned lcnr Sep 7, 2025

BennoLossin mentioned this pull request Aug 14, 2025

Tracking Issue for Field Projections #145383

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ojeda mentioned this pull request Sep 7, 2025

Rust wanted features Rust-for-Linux/linux#354

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BennoLossin force-pushed the field-projections branch from 2bd0ff4 to a6b191a Compare September 8, 2025 19:53

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tmandry added the F-field_projections `#![feature(field_projections)]` label Sep 9, 2025

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BennoLossin added 9 commits January 16, 2026 01:50

add Field trait, lang items and field_offset intrinsic

dde145a

add builtin impl of Field for field representing types

66cc751

add feature gate test

6054dad

add run-pass tests

29bf51f

test incoherent impls

8a68e63

deny accessing FRTs of private fields

51242ce

deny manual impls of the Field trait

84f2d28

deny auto trait and drop impls for FRTs

9dbc512

do not impl Field for FRTs of repr(packed) types

4a6b88b

BennoLossin force-pushed the field-projections branch from c4cdce1 to 4a6b88b Compare January 16, 2026 00:50

BennoLossin added 2 commits January 16, 2026 02:10

fixup! lower field representing types to HIR

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fixup! lower field representing types to MIR

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rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Jan 16, 2026

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BennoLossin added 10 commits January 16, 2026 11:25

tests: fix ui output

5d0b02d

tests: check auto traits and Copy for FRTs

6512db1

consolidate tests

a520352

fixup! lower field representing types to MIR

37be83f

tests: more nonexistent

1faa03d

tests: add invalid syntax

31a061c

tests: fix symbol generation

f8c84a3

tests: add nonexistent tuple fields

306b84e

tests: expect(incomplete_features) instead of allow

945cfb4

tests: add offset function

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BennoLossin added 2 commits January 16, 2026 13:28

tests: bad normalization case for next-solver

66149ce

tests: fix debuginfo

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		// FIXME(FRTs): add FieldId to the visitor infrastructure if we need to visit it.
		ty::FRT(ty, _field) => ty.visit_with(visitor),

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Add Field Representing Types (FRTs)

API added to core::field

Explanation of Field Representing Types (FRTs)

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API added to `core::field`

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