Compiler panic playing with "Err" and lifetimes

https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=6c164108f5d960cd9bab160927e69986

Hitting "Run" will generate a compiler panic.

Code copied from play link to make this easier to read:

#[derive(PartialEq, Debug)]
enum Res<'a, T> {
    Ok(&'a str, T),
    Err(String)
}

fn get_res<'a, T>(s: &'a str) -> Res<'a, T> {
    Ok(s, 0)
}

macro_rules! is_err { ($e:expr) => (match $e { Err(_) => true, Ok(_, _) => false})}

fn main() {
    println!("{}", is_err!(get_res()));
}

Locally I can't reproduce the ICE with rustc built from HEAD with just rustc program.rs. Maybe I'm not passing the right parameters? (not sure what parameters play.rust-lang.org is passing)

@rustbot

minified:

enum Res {
    Something
}

fn main() {
    if let Ok() = Res::Something {}
}

Backtrace:

error[E0308]: mismatched types
 --> src/main.rs:7:12
  |
7 |     if let Ok() = Res::Something() {}
  |            ^^^^   ---------------- this match expression has type `Res`
  |            |
  |            expected enum `Res`, found enum `std::result::Result`
  |
  = note: expected enum `Res`
             found enum `std::result::Result<_, _>`

error: internal compiler error: src/librustc/ty/subst.rs:610: type parameter `T/#0` (T/0) out of range when substituting (root type=Some(T)) substs=[]

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:851:9
stack backtrace:
   0:     0x7f0bb42115e4 - backtrace::backtrace::libunwind::trace::ha87d00c939e2881d
                               at /cargo/registry/src/github.life-white.uk-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1:     0x7f0bb42115e4 - backtrace::backtrace::trace_unsynchronized::h016b03a8ea0b9a9f
                               at /cargo/registry/src/github.life-white.uk-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2:     0x7f0bb42115e4 - std::sys_common::backtrace::_print_fmt::hfe96d08d6bc9b78a
                               at src/libstd/sys_common/backtrace.rs:84
   3:     0x7f0bb42115e4 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h3b3abdb96a6d8973
                               at src/libstd/sys_common/backtrace.rs:61
   4:     0x7f0bb4249cfc - core::fmt::write::h3f73f70567a9d69c
                               at src/libcore/fmt/mod.rs:1024
   5:     0x7f0bb4205947 - std::io::Write::write_fmt::h7a7dac6f9b6edbe2
                               at src/libstd/io/mod.rs:1428
   6:     0x7f0bb4215a8e - std::sys_common::backtrace::_print::h26e7c67b8d6504c8
                               at src/libstd/sys_common/backtrace.rs:65
   7:     0x7f0bb4215a8e - std::sys_common::backtrace::print::h8adaf32a939cdd8b
                               at src/libstd/sys_common/backtrace.rs:50
   8:     0x7f0bb4215a8e - std::panicking::default_hook::{{closure}}::h8bd3295a48e2a09e
                               at src/libstd/panicking.rs:193
   9:     0x7f0bb4215781 - std::panicking::default_hook::hc4fa4a1f08ea09c8
                               at src/libstd/panicking.rs:210
  10:     0x7f0bb475bdf3 - rustc_driver::report_ice::hbd3df6a32fc97681
  11:     0x7f0bb4216240 - std::panicking::rust_panic_with_hook::h21d3a9bbac50e22b
                               at src/libstd/panicking.rs:475
  12:     0x7f0bb616f6ed - std::panicking::begin_panic::he8a33eedeeea7040
  13:     0x7f0bb61f71bc - rustc_errors::HandlerInner::span_bug::h37e8ebba00204083
  14:     0x7f0bb61f787a - rustc_errors::Handler::span_bug::h02472eb2367a08df
  15:     0x7f0bb5d35149 - rustc::util::bug::opt_span_bug_fmt::{{closure}}::h4f95ef7460694392
  16:     0x7f0bb5d343d3 - rustc::ty::context::tls::with_opt::{{closure}}::h5afe3012647ec3fd
  17:     0x7f0bb5d3438b - rustc::ty::context::tls::with_opt::h257d11117491697c
  18:     0x7f0bb5d35038 - rustc::util::bug::opt_span_bug_fmt::h01598306a8f0573e
  19:     0x7f0bb5d34fea - rustc::util::bug::span_bug_fmt::h0835ed719d6e2ed8
  20:     0x7f0bb5dc5b2f - <rustc::ty::subst::SubstFolder as rustc::ty::fold::TypeFolder>::fold_ty::hbbb72cfb892c1b63
  21:     0x7f0bb5f61f85 - rustc::ty::FieldDef::ty::h140a6bb42e449639
  22:     0x7f0bb4ca6901 - rustc_typeck::check::pat::<impl rustc_typeck::check::FnCtxt>::check_pat_tuple_struct::h9511a8993dce923a
  23:     0x7f0bb4ca3f67 - rustc_typeck::check::pat::<impl rustc_typeck::check::FnCtxt>::check_pat::h736329b26084fbb5
  24:     0x7f0bb4d5e912 - <core::iter::adapters::Map<I,F> as core::iter::traits::iterator::Iterator>::fold::h49157446740fe904
  25:     0x7f0bb4ca20f0 - rustc_typeck::check::_match::<impl rustc_typeck::check::FnCtxt>::check_match::h0d5c3585f435190b
  26:     0x7f0bb4cb5907 - rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind::hf2ab07d921747b7a
  27:     0x7f0bb4cb490b - rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs::h95d2d822b3735bac
  28:     0x7f0bb4cec28e - rustc_typeck::check::FnCtxt::check_block_with_expected::hbffe500c6c048e59
  29:     0x7f0bb4cb53d4 - rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind::hf2ab07d921747b7a
  30:     0x7f0bb4cb490b - rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs::h95d2d822b3735bac
  31:     0x7f0bb4cbebfb - rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_return_expr::h5fcf7e53ff250fd6
  32:     0x7f0bb4cd916f - rustc_typeck::check::check_fn::hbef22e81bc01eb20
  33:     0x7f0bb4e7a1b1 - rustc::ty::context::tls::with_context::{{closure}}::h7932aedc1560e459
  34:     0x7f0bb4cd7f92 - rustc_typeck::check::typeck_tables_of::h66eb2b8efcae4cc9
  35:     0x7f0bb4eadcbb - rustc::ty::query::__query_compute::typeck_tables_of::h382c93cac39eda56
  36:     0x7f0bb4dfa60b - rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::compute::hd4495859c5f91d5a
  37:     0x7f0bb4d8e39a - rustc::dep_graph::graph::DepGraph::with_task_impl::h80bc38d12cb846fc
  38:     0x7f0bb4e47126 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::h9874f33e2172d33e
  39:     0x7f0bb4df6d2f - rustc::ty::<impl rustc::ty::context::TyCtxt>::par_body_owners::h21fb50e660913f81
  40:     0x7f0bb4cd78ad - rustc_typeck::check::typeck_item_bodies::hdd45daad422e9bfc
  41:     0x7f0bb4eae116 - rustc::ty::query::__query_compute::typeck_item_bodies::h08d665ea8132ac5b
  42:     0x7f0bb4d998ae - rustc::dep_graph::graph::DepGraph::with_task_impl::hf917987409a7e530
  43:     0x7f0bb4e5f922 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::he0a7b411ab4af04b
  44:     0x7f0bb4eb80e4 - rustc_typeck::check_crate::h7c28fac46c030bd0
  45:     0x7f0bb48b30a4 - rustc_interface::passes::analysis::hc79844b4fa52b1a0
  46:     0x7f0bb476c352 - rustc::ty::query::__query_compute::analysis::h33a745a409331ce9
  47:     0x7f0bb473e3fd - rustc::dep_graph::graph::DepGraph::with_task_impl::hed8a529c718b7ce2
  48:     0x7f0bb4764bff - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::hcfc77b0db446486d
  49:     0x7f0bb470d305 - rustc::ty::context::tls::enter_global::h766d78e54e64fa09
  50:     0x7f0bb47232e5 - rustc_interface::interface::run_compiler_in_existing_thread_pool::hdd156f0d1b582954
  51:     0x7f0bb46f3212 - std::thread::local::LocalKey<T>::with::h6655adf430a51c99
  52:     0x7f0bb46ec92e - scoped_tls::ScopedKey<T>::set::h94183f4219885431
  53:     0x7f0bb4767a44 - syntax::with_globals::hfc11c194934a0802
  54:     0x7f0bb46ed8d0 - std::sys_common::backtrace::__rust_begin_short_backtrace::h802025fd84452bdf
  55:     0x7f0bb4226d1a - __rust_maybe_catch_panic
                               at src/libpanic_unwind/lib.rs:78
  56:     0x7f0bb4703f39 - core::ops::function::FnOnce::call_once{{vtable.shim}}::hf9723bf79635cef7
  57:     0x7f0bb41f789f - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::hdc5bf436b8728899
                               at /rustc/6d77e45f01079fe3d40180b3e256e414ab379f63/src/liballoc/boxed.rs:969
  58:     0x7f0bb4225740 - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h5b53ac75e3d696ad
                               at /rustc/6d77e45f01079fe3d40180b3e256e414ab379f63/src/liballoc/boxed.rs:969
  59:     0x7f0bb4225740 - std::sys_common::thread::start_thread::h6ac750f81e489ecc
                               at src/libstd/sys_common/thread.rs:13
  60:     0x7f0bb4225740 - std::sys::unix::thread::Thread::new::thread_start::hd08318bf11dd0ed0
                               at src/libstd/sys/unix/thread.rs:80
  61:     0x7f0bb4162669 - start_thread
  62:     0x7f0bb4079323 - clone
  63:                0x0 - <unknown>

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 1.41.0-nightly (6d77e45f0 2019-12-04) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [typeck_tables_of] processing `main`
#1 [typeck_item_bodies] type-checking all item bodies
#2 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 2 previous errors

@rustbot modify labels: I-ICE T-compiler C-bug

@hellow554

@hellow554 is this output from play.rust-lang.org or locally? How do you run rustc exactly to get this? I'm still not getting any ICEs locally, I wonder how you do it.

@osa1

@osa1 locally by using either cargo or rustc directly.

note: rustc 1.41.0-nightly (6d77e45 2019-12-04) running on x86_64-unknown-linux-gnu

Interesting, I get an ICE on another tree (I wonder what the difference is ...). The exact ICE message is different than the one in play.rust-lang, but the panic is in the same module (rustc::ty::subst).

This is a regression from 1.38.0 to 1.39.0 and was introduced in ef906d0

This should have been fixed by #67044.

triage: P-high, removing nomination

Has already been fixed on f6840f3.
So I guess like Centril already said, fixed by #67044.

So this can be closed?

Nightly output:

error[E0061]: this function takes 1 parameter but 2 parameters were supplied
 --> src/main.rs:8:5
  |
8 |     Ok(s, 0)
  |     ^^^^^^^^ expected 1 parameter

error[E0308]: mismatched types
 --> src/main.rs:8:5
  |
8 |     Ok(s, 0)
  |     ^^^^^^^^ expected enum `Res`, found enum `std::result::Result`
  |
  = note: expected enum `Res<'a, T>`
             found enum `std::result::Result<_, _>`

error[E0061]: this function takes 1 parameter but 0 parameters were supplied
  --> src/main.rs:14:28
   |
7  | fn get_res<'a, T>(s: &'a str) -> Res<'a, T> {
   | ------------------------------------------- defined here
...
14 |     println!("{}", is_err!(get_res()));
   |                            ^^^^^^^^^ expected 1 parameter

error[E0308]: mismatched types
  --> src/main.rs:11:48
   |
11 | macro_rules! is_err { ($e:expr) => (match $e { Err(_) => true, Ok(_, _) => false})}
   |                                                ^^^^^^ expected enum `Res`, found enum `std::result::Result`
...
14 |     println!("{}", is_err!(get_res()));
   |                    ------------------
   |                    |       |
   |                    |       this match expression has type `Res<'_, _>`
   |                    in this macro invocation
   |
   = note: expected enum `Res<'_, _>`
              found enum `std::result::Result<_, _>`

error[E0308]: mismatched types
  --> src/main.rs:11:64
   |
11 | macro_rules! is_err { ($e:expr) => (match $e { Err(_) => true, Ok(_, _) => false})}
   |                                                                ^^^^^^^^ expected enum `Res`, found enum `std::result::Result`
...
14 |     println!("{}", is_err!(get_res()));
   |                    ------------------
   |                    |       |
   |                    |       this match expression has type `Res<'_, _>`
   |                    in this macro invocation
   |
   = note: expected enum `Res<'_, _>`
              found enum `std::result::Result<_, _>`

error[E0023]: this pattern has 2 fields, but the corresponding tuple variant has 1 field
   --> src/main.rs:11:64
    |
11  | macro_rules! is_err { ($e:expr) => (match $e { Err(_) => true, Ok(_, _) => false})}
    |                                                                ^^^^^^^^ expected 1 field, found 2
...
14  |     println!("{}", is_err!(get_res()));
    |                    ------------------ in this macro invocation

error: aborting due to 6 previous errors

Closing as fixed by that PR.

Navigation Menu

Repository navigation

Compiler panic playing with "Err" and lifetimes #67072

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Compiler panic playing with "Err" and lifetimes #67072

Description

Activity

osa1 commented on Dec 6, 2019

hellow554 commented on Dec 6, 2019

osa1 commented on Dec 6, 2019

hellow554 commented on Dec 6, 2019

osa1 commented on Dec 6, 2019

hellow554 commented on Dec 6, 2019

Centril commented on Dec 6, 2019

pnkfelix commented on Dec 12, 2019

hellow554 commented on Dec 12, 2019

estebank commented on Dec 14, 2019

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions