ICE. `try_from_lit: received const param which shouldn't be possible`

[matthiaskrgr]

auto-reduced (treereduce-rust):

#![feature(generic_const_exprs)]

fn zero_init<const usize: usize>() -> Substs1<{ (N) }> {
    Substs1([0; { (usize) }])
}

original:

// run-pass
#![feature(generic_const_exprs)]
#![allow(incomplete_features, unused_parens, unused_braces)]

fn zero_init<const usize: usize>() -> Substs1<{ (N) }>
where
    [u8; { (usize) }]: ,
{
    Substs1([0; { (usize) }])
}

struct Substs1<const usize: usize>([u8; { (N) }])
where
    [(); { (usize) }]: ;

fn substs2<const M: usize>() -> Substs1<{ (M) }> {
    zero_init::<{ (M) }>()
}

fn substs3<const L: usize>() -> Substs1<{ (L) }> {
    substs2::<{ (L) }>()
}

fn main() {
    assert_eq!(substs3::<2>().0, [0; 2]);
}

// Test that the implicit ``{ (L) }`` bound on ``substs3`` satisfies the
// ``{ (N) }`` bound on ``Substs1``

Version information

rustc 1.81.0-nightly (11e57241f 2024-07-19)
binary: rustc
commit-hash: 11e57241f166194a328438d9264b68c98a18d51f
commit-date: 2024-07-19
host: x86_64-unknown-linux-gnu
release: 1.81.0-nightly
LLVM version: 18.1.7

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

Program output

error[E0412]: cannot find type `Substs1` in this scope
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:3:39
  |
3 | fn zero_init<const usize: usize>() -> Substs1<{ (N) }> {
  |                                       ^^^^^^^ not found in this scope

error[E0425]: cannot find value `N` in this scope
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:3:50
  |
3 | fn zero_init<const usize: usize>() -> Substs1<{ (N) }> {
  |                                                  ^ not found in this scope
  |
help: you might be missing a const parameter
  |
3 | fn zero_init<const usize: usize, const N: /* Type */>() -> Substs1<{ (N) }> {
  |                                +++++++++++++++++++++

warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:1:12
  |
1 | #![feature(generic_const_exprs)]
  |            ^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
  = note: `#[warn(incomplete_features)]` on by default

warning: unnecessary parentheses around block return value
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:3:49
  |
3 | fn zero_init<const usize: usize>() -> Substs1<{ (N) }> {
  |                                                 ^ ^
  |
  = note: `#[warn(unused_parens)]` on by default
help: remove these parentheses
  |
3 - fn zero_init<const usize: usize>() -> Substs1<{ (N) }> {
3 + fn zero_init<const usize: usize>() -> Substs1<{ N }> {
  |

warning: unnecessary parentheses around block return value
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:4:19
  |
4 |     Substs1([0; { (usize) }])
  |                   ^     ^
  |
help: remove these parentheses
  |
4 -     Substs1([0; { (usize) }])
4 +     Substs1([0; { usize }])
  |

error[E0601]: `main` function not found in crate `mvce`
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:5:2
  |
5 | }
  |  ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs`

error: internal compiler error: compiler/rustc_middle/src/ty/consts.rs:322:13: try_from_lit: received const param which shouldn't be possible
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:4:19
  |
4 |     Substs1([0; { (usize) }])
  |                   ^^^^^^^

thread 'rustc' panicked at compiler/rustc_middle/src/ty/consts.rs:322:13:
Box<dyn Any>
stack backtrace:
   0:     0x712459dba125 - std::backtrace_rs::backtrace::libunwind::trace::hf98a5915ebb35e48
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/../../backtrace/src/backtrace/libunwind.rs:116:5
   1:     0x712459dba125 - std::backtrace_rs::backtrace::trace_unsynchronized::hd655af97e2fd6730
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x712459dba125 - std::sys::backtrace::_print_fmt::h621db2f84bb6c977
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/sys/backtrace.rs:65:5
   3:     0x712459dba125 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h15411039d8520454
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/sys/backtrace.rs:40:26
   4:     0x712459e09c2b - core::fmt::rt::Argument::fmt::h67bd01cd3519872c
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/core/src/fmt/rt.rs:173:76
   5:     0x712459e09c2b - core::fmt::write::hadd1ce33df102529
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/core/src/fmt/mod.rs:1182:21
   6:     0x712459daebff - std::io::Write::write_fmt::h2f869538ed52830c
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/io/mod.rs:1827:15
   7:     0x712459dbc911 - std::sys::backtrace::BacktraceLock::print::hbc3230efeae1e486
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/sys/backtrace.rs:43:9
   8:     0x712459dbc911 - std::panicking::default_hook::{{closure}}::h218c8d9fd7d09778
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/panicking.rs:269:22
   9:     0x712459dbc5ec - std::panicking::default_hook::hb07cda98c1c69610
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/panicking.rs:296:9
  10:     0x71245622d86a - std[6b173760e3c5fb6]::panicking::update_hook::<alloc[90d8a7b433d20df0]::boxed::Box<rustc_driver_impl[25cb91e50f1896ac]::install_ice_hook::{closure#0}>>::{closure#0}
  11:     0x712459dbd2df - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h47aca6625104f576
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/alloc/src/boxed.rs:2084:9
  12:     0x712459dbd2df - std::panicking::rust_panic_with_hook::h4eb1d6a88426bb57
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/panicking.rs:808:13
  13:     0x712456268121 - std[6b173760e3c5fb6]::panicking::begin_panic::<rustc_errors[8a52d81e420a7663]::ExplicitBug>::{closure#0}
  14:     0x71245625af26 - std[6b173760e3c5fb6]::sys::backtrace::__rust_end_short_backtrace::<std[6b173760e3c5fb6]::panicking::begin_panic<rustc_errors[8a52d81e420a7663]::ExplicitBug>::{closure#0}, !>
  15:     0x71245625aed6 - std[6b173760e3c5fb6]::panicking::begin_panic::<rustc_errors[8a52d81e420a7663]::ExplicitBug>
  16:     0x7124562715a1 - <rustc_errors[8a52d81e420a7663]::diagnostic::BugAbort as rustc_errors[8a52d81e420a7663]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  17:     0x7124567e920d - <rustc_errors[8a52d81e420a7663]::DiagCtxtHandle>::span_bug::<rustc_span[bca8f273264d3c53]::span_encoding::Span, alloc[90d8a7b433d20df0]::string::String>
  18:     0x7124568879b8 - rustc_middle[d4947050f46ff72a]::util::bug::opt_span_bug_fmt::<rustc_span[bca8f273264d3c53]::span_encoding::Span>::{closure#0}
  19:     0x71245686db7a - rustc_middle[d4947050f46ff72a]::ty::context::tls::with_opt::<rustc_middle[d4947050f46ff72a]::util::bug::opt_span_bug_fmt<rustc_span[bca8f273264d3c53]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  20:     0x71245686d9fb - rustc_middle[d4947050f46ff72a]::ty::context::tls::with_context_opt::<rustc_middle[d4947050f46ff72a]::ty::context::tls::with_opt<rustc_middle[d4947050f46ff72a]::util::bug::opt_span_bug_fmt<rustc_span[bca8f273264d3c53]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  21:     0x7124568878e7 - rustc_middle[d4947050f46ff72a]::util::bug::span_bug_fmt::<rustc_span[bca8f273264d3c53]::span_encoding::Span>
  22:     0x712458fb50bf - <rustc_middle[d4947050f46ff72a]::ty::consts::Const>::from_anon_const.cold
  23:     0x71245838f4ad - <rustc_hir_typeck[3d0bcd2c694d45c9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  24:     0x712454440cad - <rustc_hir_typeck[3d0bcd2c694d45c9]::fn_ctxt::FnCtxt>::confirm_builtin_call
  25:     0x7124583888e8 - <rustc_hir_typeck[3d0bcd2c694d45c9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  26:     0x7124583836e5 - <rustc_hir_typeck[3d0bcd2c694d45c9]::fn_ctxt::FnCtxt>::check_block_with_expected
  27:     0x71245838951d - <rustc_hir_typeck[3d0bcd2c694d45c9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  28:     0x712457bb74cf - rustc_hir_typeck[3d0bcd2c694d45c9]::check::check_fn
  29:     0x712458207381 - rustc_hir_typeck[3d0bcd2c694d45c9]::typeck
  30:     0x712458206d1d - rustc_query_impl[dfa85d359d8bf55f]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[dfa85d359d8bf55f]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[d4947050f46ff72a]::query::erase::Erased<[u8; 8usize]>>
  31:     0x712457bd8ab3 - rustc_query_system[5fd7963a6e62591]::query::plumbing::try_execute_query::<rustc_query_impl[dfa85d359d8bf55f]::DynamicConfig<rustc_query_system[5fd7963a6e62591]::query::caches::VecCache<rustc_span[bca8f273264d3c53]::def_id::LocalDefId, rustc_middle[d4947050f46ff72a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[dfa85d359d8bf55f]::plumbing::QueryCtxt, false>
  32:     0x712457bd7c8d - rustc_query_impl[dfa85d359d8bf55f]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  33:     0x712457bd788e - <rustc_middle[d4947050f46ff72a]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[67f94dc96106c366]::check_crate::{closure#4}>::{closure#0}
  34:     0x712457bd56ce - rustc_hir_analysis[67f94dc96106c366]::check_crate
  35:     0x712457bcbd95 - rustc_interface[e83b188aca6a6213]::passes::analysis
  36:     0x712457bcb947 - rustc_query_impl[dfa85d359d8bf55f]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[dfa85d359d8bf55f]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[d4947050f46ff72a]::query::erase::Erased<[u8; 1usize]>>
  37:     0x7124586c3965 - rustc_query_system[5fd7963a6e62591]::query::plumbing::try_execute_query::<rustc_query_impl[dfa85d359d8bf55f]::DynamicConfig<rustc_query_system[5fd7963a6e62591]::query::caches::SingleCache<rustc_middle[d4947050f46ff72a]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[dfa85d359d8bf55f]::plumbing::QueryCtxt, false>
  38:     0x7124586c36cf - rustc_query_impl[dfa85d359d8bf55f]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  39:     0x7124585e8a05 - rustc_interface[e83b188aca6a6213]::interface::run_compiler::<core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>, rustc_driver_impl[25cb91e50f1896ac]::run_compiler::{closure#0}>::{closure#1}
  40:     0x7124585a1749 - std[6b173760e3c5fb6]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[e83b188aca6a6213]::util::run_in_thread_with_globals<rustc_interface[e83b188aca6a6213]::util::run_in_thread_pool_with_globals<rustc_interface[e83b188aca6a6213]::interface::run_compiler<core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>, rustc_driver_impl[25cb91e50f1896ac]::run_compiler::{closure#0}>::{closure#1}, core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>>::{closure#0}, core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>>
  41:     0x7124585a14fa - <<std[6b173760e3c5fb6]::thread::Builder>::spawn_unchecked_<rustc_interface[e83b188aca6a6213]::util::run_in_thread_with_globals<rustc_interface[e83b188aca6a6213]::util::run_in_thread_pool_with_globals<rustc_interface[e83b188aca6a6213]::interface::run_compiler<core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>, rustc_driver_impl[25cb91e50f1896ac]::run_compiler::{closure#0}>::{closure#1}, core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>>::{closure#0}, core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9625cf1cb95ebe7c]::result::Result<(), rustc_span[bca8f273264d3c53]::ErrorGuaranteed>>::{closure#2} as core[9625cf1cb95ebe7c]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  42:     0x712459dc733b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd3e0782f209a59bb
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/alloc/src/boxed.rs:2070:9
  43:     0x712459dc733b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h2ffe75b9a73fa277
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/alloc/src/boxed.rs:2070:9
  44:     0x712459dc733b - std::sys::pal::unix::thread::Thread::new::thread_start::he38da8e39f41a015
                               at /rustc/11e57241f166194a328438d9264b68c98a18d51f/library/std/src/sys/pal/unix/thread.rs:108:17
  45:     0x712452ca6ded - <unknown>
  46:     0x712452d2a0dc - <unknown>
  47:                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: please make sure that you have updated to the latest nightly

note: rustc 1.81.0-nightly (11e57241f 2024-07-19) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [typeck] type-checking `zero_init`
#1 [analysis] running analysis passes on this crate
end of query stack
error[E0425]: cannot find function, tuple struct or tuple variant `Substs1` in this scope
 --> /tmp/icemaker_global_tempdir.eb7oiLkfZ922/rustc_testrunner_tmpdir_reporting.s4RjyJctpWhy/mvce.rs:4:5
  |
4 |     Substs1([0; { (usize) }])
  |     ^^^^^^^ not found in this scope

error: aborting due to 5 previous errors; 3 warnings emitted

Some errors have detailed explanations: E0412, E0425, E0601.
For more information about an error, try `rustc --explain E0412`.

@rustbot label +F-generic_const_exprs

[camelid]

This is probably due to my recent PR #125915. I'll look into what's going on. @rustbot claim

[camelid]

Ok Boxy and I discussed this. It seems like we just need to decide whether (N) is considered the same as N for the purpose of deciding between ConstArgKind::Path and ::Anon. Likely parts of rustc are thinking it's a path while others think it's an anon, causing the ICE.

[GrigorenkoPV]

This is probably due to my recent PR #125915.

Yep, regresses to it. (And so does #127970)

[oli-obk]

Less noisy repro (no separate errors)

struct Foo<const A: u32>;

fn foo<const X: u32>(_: Foo<{X::<()>}>) {}