ICE -Zsave-analysis: const-param-type-depends-on-type-param-ungated.rs

[matthiaskrgr]

rustc -Zsave-analysis src/test/ui/const-generics/const-param-type-depends-on-type-param-ungated.rs

Code

use std::marker::PhantomData;

struct B<T, const N: T>(PhantomData<[T; N]>); //~ ERROR const generics are unstable
//~^ ERROR the types of const generic parameters must derive `PartialEq` and `Eq`

fn main() {}

Meta

rustc --version --verbose:

rustc 1.43.0-nightly (436494b8f 2020-02-22)
binary: rustc
commit-hash: 436494b8f8008b600d64b3951f63c2bb0ea81673
commit-date: 2020-02-22
host: x86_64-unknown-linux-gnu
release: 1.43.0-nightly
LLVM version: 9.0

Error output

error[E0658]: const generics are unstable
 --> ./ui/const-generics/const-param-type-depends-on-type-param-ungated.rs:3:19
  |
3 | struct B<T, const N: T>(PhantomData<[T; N]>); //~ ERROR const generics are unstable
  |                   ^
  |
  = note: see issue #44580 <https://github.com/rust-lang/rust/issues/44580> for more information
  = help: add `#![feature(const_generics)]` to the crate attributes to enable

error[E0741]: the types of const generic parameters must derive `PartialEq` and `Eq`
 --> ./ui/const-generics/const-param-type-depends-on-type-param-ungated.rs:3:22
  |
3 | struct B<T, const N: T>(PhantomData<[T; N]>); //~ ERROR const generics are unstable
  |                      ^ `T` doesn't derive both `PartialEq` and `Eq`

error: internal compiler error: src/librustc/ty/subst.rs:565: type parameter `T/#0` (T/0) out of range when substituting (root type=Some(T)) substs=[]

thread 'rustc' panicked at 'Box<Any>', <::std::macros::panic macros>:2:4
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.43.0-nightly (436494b8f 2020-02-22) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z save-analysis

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0658, E0741.
For more information about an error, try `rustc --explain E0658`.

Backtrace

error[E0658]: const generics are unstable
 --> ./ui/const-generics/const-param-type-depends-on-type-param-ungated.rs:3:19
  |
3 | struct B<T, const N: T>(PhantomData<[T; N]>); //~ ERROR const generics are unstable
  |                   ^
  |
  = note: see issue #44580 <https://github.com/rust-lang/rust/issues/44580> for more information
  = help: add `#![feature(const_generics)]` to the crate attributes to enable

error[E0741]: the types of const generic parameters must derive `PartialEq` and `Eq`
 --> ./ui/const-generics/const-param-type-depends-on-type-param-ungated.rs:3:22
  |
3 | struct B<T, const N: T>(PhantomData<[T; N]>); //~ ERROR const generics are unstable
  |                      ^ `T` doesn't derive both `PartialEq` and `Eq`

error: internal compiler error: src/librustc/ty/subst.rs:565: type parameter `T/#0` (T/0) out of range when substituting (root type=Some(T)) substs=[]

thread 'rustc' panicked at 'Box<Any>', <::std::macros::panic macros>:2:4
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.44/src/backtrace/libunwind.rs:86
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.44/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:78
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:59
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1052
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1428
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:62
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:204
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:224
  10: rustc_driver::report_ice
  11: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:474
  12: std::panicking::begin_panic
  13: rustc_errors::HandlerInner::span_bug
  14: rustc_errors::Handler::span_bug
  15: rustc::util::bug::opt_span_bug_fmt::{{closure}}
  16: rustc::ty::context::tls::with_opt::{{closure}}
  17: rustc::ty::context::tls::with_opt
  18: rustc::util::bug::opt_span_bug_fmt
  19: rustc::util::bug::span_bug_fmt
  20: <rustc::ty::subst::SubstFolder as rustc::ty::fold::TypeFolder>::fold_ty
  21: rustc_typeck::check::FnCtxt::instantiate_value_path
  22: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  23: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  24: rustc::ty::context::GlobalCtxt::enter_local
  25: rustc_typeck::check::typeck_tables_of
  26: rustc::ty::query::__query_compute::typeck_tables_of
  27: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::compute
  28: rustc::dep_graph::graph::DepGraph::with_task_impl
  29: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  30: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_ty
  31: syntax::visit::walk_generic_args
  32: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_ty
  33: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_item
  34: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_mod
  35: rustc::dep_graph::graph::DepGraph::with_ignore
  36: rustc_session::utils::<impl rustc_session::session::Session>::time
  37: rustc::ty::context::tls::enter_global
  38: rustc_interface::interface::run_compiler_in_existing_thread_pool
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.43.0-nightly (436494b8f 2020-02-22) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z save-analysis

query stack during panic:
#0 [typeck_tables_of] type-checking `B::0::{{constant}}#0`
end of query stack
error: aborting due to 3 previous errors

Some errors have detailed explanations: E0658, E0741.
For more information about an error, try `rustc --explain E0658`.