Start using pattern types in libcore

[oli-obk]

cc #135996

blocked on rust-analyzer getting support for computing the right layout for pattern types

cc @Veykril no rush here, as long as we can't replace NonNull, there's no point in doing this change just yet

[compiler-errors]

Well r=me when/if it does get unblocked.

[scottmcm]

Unsure: at least for the NonZeroBlahInner ones, it'd be nicer if these could just be type $name = pattern_type!($int is $low..=$high);, without the extra wrapper. Is that feasible, or are the trait implementations too far off?

(Relatedly, I'd love to be able to just derive traits on these again, particularly to not have to manually StructuralPartialEq.)

[oli-obk]

Yea... I wanna get there, but directly using pattern types is not a great experience at present

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[Veykril]

Re rust-analyzer blocker, as it turns out to implement pattern types (to a degree that would unblock this) it comes down to the same architecture changes required as for rust-lang/rust-analyzer#7434 (which I am currently looking into), so that will take a bit.

[rustbot]

Some changes occurred to the CTFE machinery

cc @rust-lang/wg-const-eval

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

[Veykril]

Re rust-analyzer blocker, as it turns out to implement pattern types (to a degree that would unblock this) it comes down to the same architecture changes required as for rust-lang/rust-analyzer#7434 (which I am currently looking into), so that will take a bit.

@Veykril I think for the most part you could just treat pattern types opaquely and ignore the pattern's details. Casts to the base type don't require looking at the pattern and instantiating pattern types from literals could just be ignored by r-a and left to rustc. I don't think you actually need the layout of pattern types for anything else

But isn't the point of them that they have niches? If we treat them opaquely we won't see the niches of the type for layout calculation.

Either way I should be unblocked regarding rust-lang/rust-analyzer#7434 so I can start working on that again starting next week. Though if you want to get this merged and r-a is the remaining blocking reason we can work around it by special casing the relevant std/core type(s) if needed I think

[oli-obk]

But isn't the point of them that they have niches? If we treat them opaquely we won't see the niches of the type for layout calculation.

Ah then the sizes shown by ra would be wrong. Hmm I've never seem the sizes, didn't think about that

[rustbot]

The Miri subtree was changed

cc @rust-lang/miri

[bors]

☔ The latest upstream changes (presumably #138464) made this pull request unmergeable. Please resolve the merge conflicts.

[Veykril]

Btw, the implementation block has been lifted in r-a. (that is the pre-requisite work for rust-lang/rust-analyzer#7434). But since we still use chalk's IR we can't represent pattern types in the type system yet, so that's still kind of blocked there.

[rust-log-analyzer]

The job x86_64-gnu-llvm-19 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

#19 exporting to docker image format
#19 sending tarball 20.2s done
#19 DONE 24.6s
##[endgroup]
Setting extra environment values for docker:  --env ENABLE_GCC_CODEGEN=1 --env GCC_EXEC_PREFIX=/usr/lib/gcc/
[CI_JOB_NAME=x86_64-gnu-llvm-19]
[CI_JOB_NAME=x86_64-gnu-llvm-19]
debug: `DISABLE_CI_RUSTC_IF_INCOMPATIBLE` configured.
---
sccache: Listening on address 127.0.0.1:4226
##[group]Configure the build
configure: processing command line
configure: 
configure: build.configure-args := ['--build=x86_64-unknown-linux-gnu', '--llvm-root=/usr/lib/llvm-19', '--enable-llvm-link-shared', '--set', 'rust.randomize-layout=true', '--set', 'rust.thin-lto-import-instr-limit=10', '--set', 'build.print-step-timings', '--enable-verbose-tests', '--set', 'build.metrics', '--enable-verbose-configure', '--enable-sccache', '--disable-manage-submodules', '--enable-locked-deps', '--enable-cargo-native-static', '--set', 'rust.codegen-units-std=1', '--set', 'dist.compression-profile=balanced', '--dist-compression-formats=xz', '--set', 'rust.lld=false', '--disable-dist-src', '--release-channel=nightly', '--enable-debug-assertions', '--enable-overflow-checks', '--enable-llvm-assertions', '--set', 'rust.verify-llvm-ir', '--set', 'rust.codegen-backends=llvm,cranelift,gcc', '--set', 'llvm.static-libstdcpp', '--set', 'gcc.download-ci-gcc=true', '--enable-new-symbol-mangling']
configure: build.build          := x86_64-unknown-linux-gnu
configure: target.x86_64-unknown-linux-gnu.llvm-config := /usr/lib/llvm-19/bin/llvm-config
configure: llvm.link-shared     := True
configure: rust.randomize-layout := True
configure: rust.thin-lto-import-instr-limit := 10
---
[RUSTC-TIMING] ____ test:false 0.026
##[endgroup]
##[group][AOT] arbitrary_self_types_pointers_and_wrappers
[AOT] arbitrary_self_types_pointers_and_wrappers
##[error]error: internal compiler error: compiler/rustc_codegen_cranelift/src/unsize.rs:173:14: coerce_unsized_into: invalid coercion pattern_type!(*const Wrapper<i32> is !null) -> pattern_type!(*const Wrapper<dyn [Binder { value: Trait(Trait), bound_vars: [] }] + '{erased}> is !null)


thread 'rustc' panicked at compiler/rustc_codegen_cranelift/src/unsize.rs:173:14:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   3: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   4: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   5: rustc_middle::util::bug::bug_fmt
   6: rustc_codegen_cranelift::unsize::coerce_unsized_into
   7: rustc_codegen_cranelift::unsize::coerce_unsized_into
   8: rustc_codegen_cranelift::unsize::coerce_unsized_into
   9: rustc_codegen_cranelift::unsize::coerce_unsized_into
  10: rustc_codegen_cranelift::unsize::coerce_unsized_into
  11: rustc_codegen_cranelift::base::codegen_fn_body
  12: rustc_codegen_cranelift::base::codegen_fn
  13: rustc_codegen_cranelift::driver::aot::module_codegen
  14: rustc_codegen_cranelift::driver::aot::run_aot::{closure#3}::{closure#0}
  15: <&mut rustc_data_structures::sync::parallel::par_map<(usize, &rustc_middle::mir::mono::CodegenUnit), alloc::vec::Vec<(usize, &rustc_middle::mir::mono::CodegenUnit)>, rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>, alloc::vec::Vec<rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>>, rustc_codegen_cranelift::driver::aot::run_aot::{closure#3}::{closure#0}>::{closure#0}::{closure#3} as core::ops::function::FnMut<((usize, &rustc_middle::mir::mono::CodegenUnit),)>>::call_mut
  16: <alloc::vec::into_iter::IntoIter<(usize, &rustc_middle::mir::mono::CodegenUnit)> as core::iter::traits::iterator::Iterator>::try_fold::<(), core::iter::traits::iterator::Iterator::find_map::check<(usize, &rustc_middle::mir::mono::CodegenUnit), rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>, &mut rustc_data_structures::sync::parallel::par_map<(usize, &rustc_middle::mir::mono::CodegenUnit), alloc::vec::Vec<(usize, &rustc_middle::mir::mono::CodegenUnit)>, rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>, alloc::vec::Vec<rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>>, rustc_codegen_cranelift::driver::aot::run_aot::{closure#3}::{closure#0}>::{closure#0}::{closure#3}>::{closure#0}, core::ops::control_flow::ControlFlow<rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>>>
  17: <alloc::vec::Vec<rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>> as alloc::vec::spec_from_iter::SpecFromIter<rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>, core::iter::adapters::filter_map::FilterMap<alloc::vec::into_iter::IntoIter<(usize, &rustc_middle::mir::mono::CodegenUnit)>, rustc_data_structures::sync::parallel::par_map<(usize, &rustc_middle::mir::mono::CodegenUnit), alloc::vec::Vec<(usize, &rustc_middle::mir::mono::CodegenUnit)>, rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>, alloc::vec::Vec<rustc_data_structures::marker::IntoDynSyncSend<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>>, rustc_codegen_cranelift::driver::aot::run_aot::{closure#3}::{closure#0}>::{closure#0}::{closure#3}>>>::from_iter
  18: <rustc_session::session::Session>::time::<alloc::vec::Vec<rustc_codegen_cranelift::driver::aot::OngoingModuleCodegen>, rustc_codegen_cranelift::driver::aot::run_aot::{closure#3}>
  19: rustc_codegen_cranelift::driver::aot::run_aot
  20: <rustc_codegen_cranelift::CraneliftCodegenBackend as rustc_codegen_ssa::traits::backend::CodegenBackend>::codegen_crate
  21: rustc_interface::passes::start_codegen
  22: <rustc_interface::queries::Linker>::codegen_and_build_linker
  23: <std::thread::local::LocalKey<core::cell::Cell<*const ()>>>::with::<rustc_middle::ty::context::tls::enter_context<<rustc_middle::ty::context::GlobalCtxt>::enter<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>::{closure#1}, core::option::Option<rustc_interface::queries::Linker>>::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>
  24: <rustc_middle::ty::context::TyCtxt>::create_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}>
  25: <rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2} as core::ops::function::FnOnce<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy>, &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#2})>>::call_once::{shim:vtable#0}
  26: <alloc::boxed::Box<dyn for<'a> core::ops::function::FnOnce<(&'a rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy>, &'a std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt<'a>>, &'a rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena<'a>>, &'a rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena<'a>>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}), Output = core::option::Option<rustc_interface::queries::Linker>>> as core::ops::function::FnOnce<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy>, &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#2})>>::call_once
  27: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>
  28: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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

warning: the ICE couldn't be written to `/checkout/compiler/rustc_codegen_cranelift/rustc-ice-2025-05-06T08_47_54-255609.txt`: Read-only file system (os error 30)

note: rustc 1.88.0-nightly (5b72ed1c2 2025-05-06) running on x86_64-unknown-linux-gnu

note: compiler flags: -C panic=abort -Z panic-abort-tests -Z codegen-backend=cranelift -C symbol-mangling-version=v0 -Z randomize-layout -Z unstable-options -Z macro-backtrace -C split-debuginfo=off -C link-arg=-L/usr/lib/llvm-19/lib -C llvm-args=-import-instr-limit=10 -C link-args=-Wl,-z,origin -C link-args=-Wl,-rpath,$ORIGIN/../lib -C debuginfo=2 -C panic=abort -Z force-unstable-if-unmarked

query stack during panic:
end of query stack
stmt _1 = move _2 as Ptr<Wrapper<dyn Trait>> (PointerCoercion(Unsize, AsCast))
fn main() -> () {
    let mut _0: ();
    let mut _1: Ptr<Wrapper<dyn Trait>>;
    let mut _2: Ptr<Wrapper<i32>>;
    let mut _3: std::boxed::Box<Wrapper<i32>>;
    let mut _4: Wrapper<i32>;
    let mut _5: (&i32, &i32);
    let mut _6: &i32;
    let _7: i32;
    let mut _8: &i32;
    let mut _11: bool;
    let mut _12: i32;
    let mut _13: i32;
    let _15: !;
    let mut _16: std::option::Option<std::fmt::Arguments<'_>>;
    let mut _17: Wrapper<Ptr<dyn Trait>>;
    let mut _18: Wrapper<Ptr<i32>>;
    let mut _19: Ptr<i32>;
    let mut _20: std::boxed::Box<i32>;
    let mut _21: (&i32, &i32);
    let mut _22: &i32;
    let _23: i32;
    let mut _24: &i32;
    let mut _27: bool;
    let mut _28: i32;
    let mut _29: i32;
    let _31: !;
    let mut _32: std::option::Option<std::fmt::Arguments<'_>>;
    let mut _33: Wrapper<Ptr<Wrapper<dyn Trait>>>;
    let mut _34: Wrapper<Ptr<Wrapper<i32>>>;
    let mut _35: Ptr<Wrapper<i32>>;
    let mut _36: std::boxed::Box<Wrapper<i32>>;
    let mut _37: Wrapper<i32>;
    let mut _38: (&i32, &i32);
    let mut _39: &i32;
    let _40: i32;
    let mut _41: &i32;
    let mut _44: bool;
    let mut _45: i32;
    let mut _46: i32;
    let _48: !;
    let mut _49: std::option::Option<std::fmt::Arguments<'_>>;
    scope 1 {
        debug pw => _1;
        let _9: &i32;
        let _10: &i32;
        scope 2 {
            debug left_val => _9;
            debug right_val => _10;
            let _14: core::panicking::AssertKind;
            scope 3 {
                debug kind => _14;
            }
        }
        scope 4 {
            debug wp => _17;
            let _25: &i32;
            let _26: &i32;
            scope 5 {
                debug left_val => _25;
                debug right_val => _26;
                let _30: core::panicking::AssertKind;
                scope 6 {
                    debug kind => _30;
                }
            }
            scope 7 {
                debug wpw => _33;
                let _42: &i32;
                let _43: &i32;
                scope 8 {
                    debug left_val => _42;
                    debug right_val => _43;
                    let _47: core::panicking::AssertKind;
                    scope 9 {
                        debug kind => _47;
                    }
                }
            }
        }
    }

    bb0: {
        _4 = Wrapper::<i32>(const 5_i32);
        _3 = std::boxed::Box::<Wrapper<i32>>::new(move _4) -> [return: bb1, unwind unreachable];
    }

    bb1: {
        _2 = Ptr::<Wrapper<i32>>(move _3);
        _1 = move _2 as Ptr<Wrapper<dyn Trait>> (PointerCoercion(Unsize, AsCast));
        _7 = <dyn Trait as Trait>::ptr_wrapper(move _1) -> [return: bb2, unwind unreachable];
    }

    bb2: {
        _6 = &_7;
        _8 = const main::promoted[2];
        _5 = (move _6, move _8);
        _9 = copy (_5.0: &i32);
        _10 = copy (_5.1: &i32);
        _12 = copy (*_9);
        _13 = copy (*_10);
        _11 = Eq(move _12, move _13);
        switchInt(move _11) -> [0: bb4, otherwise: bb3];
    }

    bb3: {
        _20 = std::boxed::Box::<i32>::new(const 6_i32) -> [return: bb5, unwind unreachable];
    }

    bb4: {
        _14 = core::panicking::AssertKind::Eq;
        _16 = std::option::Option::<std::fmt::Arguments<'_>>::None;
        _15 = core::panicking::assert_failed::<i32, i32>(move _14, copy _9, copy _10, move _16) -> unwind unreachable;
    }

    bb5: {
        _19 = Ptr::<i32>(move _20);
        _18 = Wrapper::<Ptr<i32>>(move _19);
        _17 = move _18 as Wrapper<Ptr<dyn Trait>> (PointerCoercion(Unsize, AsCast));
        _23 = <dyn Trait as Trait>::wrapper_ptr(move _17) -> [return: bb6, unwind unreachable];
    }

    bb6: {
        _22 = &_23;
        _24 = const main::promoted[1];
        _21 = (move _22, move _24);
        _25 = copy (_21.0: &i32);
        _26 = copy (_21.1: &i32);
        _28 = copy (*_25);
        _29 = copy (*_26);
        _27 = Eq(move _28, move _29);
        switchInt(move _27) -> [0: bb8, otherwise: bb7];
    }

    bb7: {
        _37 = Wrapper::<i32>(const 7_i32);
        _36 = std::boxed::Box::<Wrapper<i32>>::new(move _37) -> [return: bb9, unwind unreachable];
    }

    bb8: {
        _30 = core::panicking::AssertKind::Eq;
        _32 = std::option::Option::<std::fmt::Arguments<'_>>::None;
        _31 = core::panicking::assert_failed::<i32, i32>(move _30, copy _25, copy _26, move _32) -> unwind unreachable;
    }

    bb9: {
        _35 = Ptr::<Wrapper<i32>>(move _36);
        _34 = Wrapper::<Ptr<Wrapper<i32>>>(move _35);
        _33 = move _34 as Wrapper<Ptr<Wrapper<dyn Trait>>> (PointerCoercion(Unsize, AsCast));
        _40 = <dyn Trait as Trait>::wrapper_ptr_wrapper(move _33) -> [return: bb10, unwind unreachable];
    }

    bb10: {
        _39 = &_40;
        _41 = const main::promoted[0];
        _38 = (move _39, move _41);
        _42 = copy (_38.0: &i32);
        _43 = copy (_38.1: &i32);
        _45 = copy (*_42);
        _46 = copy (*_43);
        _44 = Eq(move _45, move _46);
        switchInt(move _44) -> [0: bb12, otherwise: bb11];
    }

    bb11: {
        return;
    }

    bb12: {
        _47 = core::panicking::AssertKind::Eq;
        _49 = std::option::Option::<std::fmt::Arguments<'_>>::None;
        _48 = core::panicking::assert_failed::<i32, i32>(move _47, copy _42, copy _43, move _49) -> unwind unreachable;
    }
}

error: aborting due to 1 previous error

"/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/cg_clif/dist/rustc-clif" "-Csymbol-mangling-version=v0" "-Zrandomize-layout" "-Zunstable-options" "--check-cfg=cfg(bootstrap)" "--check-cfg=cfg(llvm_enzyme)" "-Zmacro-backtrace" "-Csplit-debuginfo=off" "-Clink-arg=-L/usr/lib/llvm-19/lib" "-Cllvm-args=-import-instr-limit=10" "-Clink-args=-Wl,-z,origin" "-Clink-args=-Wl,-rpath,$ORIGIN/../lib" "-Alinker-messages" "-L" "crate=/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/cg_clif/build/example" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/cg_clif/build/example" "-Cdebuginfo=2" "--target" "x86_64-unknown-linux-gnu" "-Cpanic=abort" "--check-cfg=cfg(jit)" "example/arbitrary_self_types_pointers_and_wrappers.rs" exited with status ExitStatus(unix_wait_status(25856))
Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:23:40
  local time: Tue May  6 08:47:54 UTC 2025
  network time: Tue, 06 May 2025 08:47:54 GMT
##[error]Process completed with exit code 1.
Post job cleanup.