ice: `is not fully resolved`

[matthiaskrgr]

Another regression of #117449 @oli-obk

snippet:

#![feature(effects)]
#![feature(min_specialization)]

trait Specialize {}

trait Foo {}

impl<T> const Foo for T {}

impl<T> const Foo for T where T: const Specialize {}

Version information

rustc 1.77.0-nightly (e92718462 2024-01-10)
binary: rustc
commit-hash: e9271846294c4ee5bd7706df68180320c0b5ff20
commit-date: 2024-01-10
host: x86_64-unknown-linux-gnu
release: 1.77.0-nightly
LLVM version: 17.0.6

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

error[E0658]: const trait impls are experimental
 --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:8:9
  |
8 | impl<T> const Foo for T {}
  |         ^^^^^
  |
  = note: see issue #67792 <https://github.com/rust-lang/rust/issues/67792> for more information
  = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable

error[E0658]: const trait impls are experimental
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:10:9
   |
10 | impl<T> const Foo for T where T: const Specialize {}
   |         ^^^^^
   |
   = note: see issue #67792 <https://github.com/rust-lang/rust/issues/67792> for more information
   = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable

error[E0658]: const trait impls are experimental
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:10:34
   |
10 | impl<T> const Foo for T where T: const Specialize {}
   |                                  ^^^^^
   |
   = note: see issue #67792 <https://github.com/rust-lang/rust/issues/67792> for more information
   = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:10:53
   |
10 | impl<T> const Foo for T where T: const Specialize {}
   |                                                     ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs`

error: const `impl` for trait `Foo` which is not marked with `#[const_trait]`
 --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:8:15
  |
6 | trait Foo {}
  | - help: mark `Foo` as const: `#[const_trait]`
7 |
8 | impl<T> const Foo for T {}
  |               ^^^
  |
  = note: marking a trait with `#[const_trait]` ensures all default method bodies are `const`
  = note: adding a non-const method body in the future would be a breaking change

error: const `impl` for trait `Foo` which is not marked with `#[const_trait]`
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:10:15
   |
6  | trait Foo {}
   | - help: mark `Foo` as const: `#[const_trait]`
...
10 | impl<T> const Foo for T where T: const Specialize {}
   |               ^^^
   |
   = note: marking a trait with `#[const_trait]` ensures all default method bodies are `const`
   = note: adding a non-const method body in the future would be a breaking change

error: `const` can only be applied to `#[const_trait]` traits
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:10:40
   |
10 | impl<T> const Foo for T where T: const Specialize {}
   |                                        ^^^^^^^^^^

error[E0207]: the const parameter `host` is not constrained by the impl trait, self type, or predicates
 --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:8:9
  |
8 | impl<T> const Foo for T {}
  |         ^^^^^ unconstrained const parameter
  |
  = note: expressions using a const parameter must map each value to a distinct output value
  = note: proving the result of expressions other than the parameter are unique is not supported

error[E0207]: the const parameter `host` is not constrained by the impl trait, self type, or predicates
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:10:9
   |
10 | impl<T> const Foo for T where T: const Specialize {}
   |         ^^^^^ unconstrained const parameter
   |
   = note: expressions using a const parameter must map each value to a distinct output value
   = note: proving the result of expressions other than the parameter are unique is not supported

error: specialization impl does not specialize any associated items
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:10:1
   |
10 | impl<T> const Foo for T where T: const Specialize {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
note: impl is a specialization of this impl
  --> /tmp/icemaker_global_tempdir.m8yucfI0lXDa/rustc_testrunner_tmpdir_reporting.dPnmsUv2HB9L/mvce.rs:8:1
   |
8  | impl<T> const Foo for T {}
   | ^^^^^^^^^^^^^^^^^^^^^^^

error: internal compiler error: /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/compiler/rustc_infer/src/infer/mod.rs:1434:21: `[T/#0, ?0e: bool]` is not fully resolved

thread 'rustc' panicked at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/compiler/rustc_errors/src/lib.rs:937:30:
Box<dyn Any>
stack backtrace:
   0:     0x7f554df8c7e6 - std::backtrace_rs::backtrace::libunwind::trace::h4e8b6d32d7dcd498
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f554df8c7e6 - std::backtrace_rs::backtrace::trace_unsynchronized::ha88031840b9f4a2e
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f554df8c7e6 - std::sys_common::backtrace::_print_fmt::h6c652548d6de2167
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f554df8c7e6 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h099aa61dbf587b72
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f554dfdeec0 - core::fmt::rt::Argument::fmt::h8ea5c32ee70cc6ed
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/core/src/fmt/rt.rs:142:9
   5:     0x7f554dfdeec0 - core::fmt::write::h465d7647510b0e90
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/core/src/fmt/mod.rs:1120:17
   6:     0x7f554df8014f - std::io::Write::write_fmt::h5c35515aeaa7e8fa
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/io/mod.rs:1810:15
   7:     0x7f554df8c5c4 - std::sys_common::backtrace::_print::h3f03a228ef688f8b
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f554df8c5c4 - std::sys_common::backtrace::print::hfa61eeb1a7b5419d
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f554df8f357 - std::panicking::default_hook::{{closure}}::h6af33eb943d51021
  10:     0x7f554df8f0b9 - std::panicking::default_hook::h7695ba792af1dd2f
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/panicking.rs:292:9
  11:     0x7f5550d55bbc - std[f174e998751286d7]::panicking::update_hook::<alloc[dd0f9dac4d1c2b55]::boxed::Box<rustc_driver_impl[87d1b731212ed153]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f554df8faa6 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hef752b8be7573308
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/alloc/src/boxed.rs:2030:9
  13:     0x7f554df8faa6 - std::panicking::rust_panic_with_hook::h53b5c8441c16b7dc
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/panicking.rs:785:13
  14:     0x7f5550d87c04 - std[f174e998751286d7]::panicking::begin_panic::<rustc_errors[1356d5bcd4a24573]::ExplicitBug>::{closure#0}
  15:     0x7f5550d844f6 - std[f174e998751286d7]::sys_common::backtrace::__rust_end_short_backtrace::<std[f174e998751286d7]::panicking::begin_panic<rustc_errors[1356d5bcd4a24573]::ExplicitBug>::{closure#0}, !>
  16:     0x7f5550d84166 - std[f174e998751286d7]::panicking::begin_panic::<rustc_errors[1356d5bcd4a24573]::ExplicitBug>
  17:     0x7f5550d92c81 - <rustc_errors[1356d5bcd4a24573]::diagnostic_builder::BugAbort as rustc_errors[1356d5bcd4a24573]::diagnostic_builder::EmissionGuarantee>::emit_producing_guarantee
  18:     0x7f555115a6ae - <rustc_errors[1356d5bcd4a24573]::DiagCtxt>::bug::<alloc[dd0f9dac4d1c2b55]::string::String>
  19:     0x7f55511f309b - rustc_middle[2f8d8a9fb975d25e]::util::bug::opt_span_bug_fmt::<rustc_span[67cae37aa81b7c83]::span_encoding::Span>::{closure#0}
  20:     0x7f55511dbc8a - rustc_middle[2f8d8a9fb975d25e]::ty::context::tls::with_opt::<rustc_middle[2f8d8a9fb975d25e]::util::bug::opt_span_bug_fmt<rustc_span[67cae37aa81b7c83]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7f55511dbb28 - rustc_middle[2f8d8a9fb975d25e]::ty::context::tls::with_context_opt::<rustc_middle[2f8d8a9fb975d25e]::ty::context::tls::with_opt<rustc_middle[2f8d8a9fb975d25e]::util::bug::opt_span_bug_fmt<rustc_span[67cae37aa81b7c83]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7f554f18d810 - rustc_middle[2f8d8a9fb975d25e]::util::bug::bug_fmt
  23:     0x7f5550e8b071 - rustc_hir_analysis[1e63daf843f87d]::impl_wf_check::min_specialization::get_impl_args
  24:     0x7f5552c1e75f - rustc_hir_analysis[1e63daf843f87d]::impl_wf_check::check_mod_impl_wf
  25:     0x7f5552c1b79d - rustc_query_impl[16d1cd34db60958]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[16d1cd34db60958]::query_impl::check_mod_impl_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2f8d8a9fb975d25e]::query::erase::Erased<[u8; 0usize]>>
  26:     0x7f5552caed8f - rustc_query_system[7153283b9fb9fb6d]::query::plumbing::try_execute_query::<rustc_query_impl[16d1cd34db60958]::DynamicConfig<rustc_query_system[7153283b9fb9fb6d]::query::caches::DefaultCache<rustc_span[67cae37aa81b7c83]::def_id::LocalModDefId, rustc_middle[2f8d8a9fb975d25e]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[16d1cd34db60958]::plumbing::QueryCtxt, false>
  27:     0x7f5552cae81f - rustc_query_impl[16d1cd34db60958]::query_impl::check_mod_impl_wf::get_query_non_incr::__rust_end_short_backtrace
  28:     0x7f55525040bb - rustc_hir_analysis[1e63daf843f87d]::check_crate
  29:     0x7f5552a562d9 - rustc_interface[c9e2075c66deb843]::passes::analysis
  30:     0x7f5552a55f1f - rustc_query_impl[16d1cd34db60958]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[16d1cd34db60958]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2f8d8a9fb975d25e]::query::erase::Erased<[u8; 1usize]>>
  31:     0x7f5552fc47a4 - rustc_query_system[7153283b9fb9fb6d]::query::plumbing::try_execute_query::<rustc_query_impl[16d1cd34db60958]::DynamicConfig<rustc_query_system[7153283b9fb9fb6d]::query::caches::SingleCache<rustc_middle[2f8d8a9fb975d25e]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[16d1cd34db60958]::plumbing::QueryCtxt, false>
  32:     0x7f5552fc4595 - rustc_query_impl[16d1cd34db60958]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  33:     0x7f5552d49408 - rustc_interface[c9e2075c66deb843]::interface::run_compiler::<core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>, rustc_driver_impl[87d1b731212ed153]::run_compiler::{closure#0}>::{closure#0}
  34:     0x7f5552fe6fc6 - std[f174e998751286d7]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[c9e2075c66deb843]::util::run_in_thread_with_globals<rustc_interface[c9e2075c66deb843]::util::run_in_thread_pool_with_globals<rustc_interface[c9e2075c66deb843]::interface::run_compiler<core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>, rustc_driver_impl[87d1b731212ed153]::run_compiler::{closure#0}>::{closure#0}, core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>>::{closure#0}, core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>>
  35:     0x7f5552fe6df3 - <<std[f174e998751286d7]::thread::Builder>::spawn_unchecked_<rustc_interface[c9e2075c66deb843]::util::run_in_thread_with_globals<rustc_interface[c9e2075c66deb843]::util::run_in_thread_pool_with_globals<rustc_interface[c9e2075c66deb843]::interface::run_compiler<core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>, rustc_driver_impl[87d1b731212ed153]::run_compiler::{closure#0}>::{closure#0}, core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>>::{closure#0}, core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[61d3efaba9c696db]::result::Result<(), rustc_span[67cae37aa81b7c83]::ErrorGuaranteed>>::{closure#1} as core[61d3efaba9c696db]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  36:     0x7f554df999d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h3063de10ed539a03
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/alloc/src/boxed.rs:2016:9
  37:     0x7f554df999d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::heefcae306faffc01
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/alloc/src/boxed.rs:2016:9
  38:     0x7f554df999d5 - std::sys::unix::thread::Thread::new::thread_start::h5c4b5675991b9c64
                               at /rustc/e9271846294c4ee5bd7706df68180320c0b5ff20/library/std/src/sys/unix/thread.rs:108:17
  39:     0x7f554dd859eb - <unknown>
  40:     0x7f554de097cc - <unknown>
  41:                0x0 - <unknown>

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: rustc 1.77.0-nightly (e92718462 2024-01-10) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [check_mod_impl_wf] checking that impls are well-formed in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 11 previous errors

Some errors have detailed explanations: E0207, E0601, E0658.
For more information about an error, try `rustc --explain E0207`.

[BoxyUwU]

This is caused by the fact that fully_resolve does not check for const effect vars when visiting Const. It should be relatively simple to match on InferConst::EffectVar in the folder.

[ajwock]

Working on this one.