ICE: bincode v2 alpha cannot be used with nightly rustc

[kdy1]

See: kdy1/wasm-perf#1

Code

use swc_common::input::SourceFileInput;
use swc_ecmascript::{
    ast::{EsVersion, Program},
    parser::{lexer::Lexer, Parser},
};

fn input() -> Program {
    testing::run_test(false, |cm, _handler| {
        let fm = cm.load_file(Path::new("benches/input.js")).unwrap();

        let lexer = Lexer::new(
            Default::default(),
            EsVersion::latest(),
            SourceFileInput::from(&*fm),
            None,
        );
        let mut parser = Parser::new_from(lexer);

        let program = parser.parse_program().unwrap();

        Ok(program)
    })
    .unwrap()
}

let program = input();

let config = bincode::Configuration::standard();
let ast_bincode = bincode::encode_to_vec(program, config.clone()).unwrap();

Ok(())

minimal reproduction.

I'll see if I can reduce further.

Meta

rustc --version --verbose:

rustc 1.58.0-nightly (ad4423997 2021-11-14)
binary: rustc
commit-hash: ad442399756573dccacb314b6bf8079964bcc72a
commit-date: 2021-11-14
host: x86_64-apple-darwin
release: 1.58.0-nightly
LLVM version: 13.0.0

Error output

thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0', /cargo/registry/src/gi
thub.com-1ecc6299db9ec823/ena-0.14.0/src/snapshot_vec.rs:199:10
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

error: internal compiler error: unexpected panic

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

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-IC
E%2C+T-compiler&template=ice.md

note: rustc 1.58.0-nightly (ad4423997 2021-11-14) running on x86_64-unknown-linux-gnu

note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C incremental --crate-type lib

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [codegen_fulfill_obligation] checking if `bincode::config::internal::InternalIntEncodingConfig` fulfil
ls its obligations
#1 [resolve_instance] resolving instance `<_ as bincode::config::internal::InternalIntEncodingConfig>::IN
T_ENCODING`

Backtrace

thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0', /Users/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/ena-0.14.0/src/snapshot_vec.rs:199:10
stack backtrace:
   0: _rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic_bounds_check
   3: <rustc_infer::infer::type_variable::TypeVariableTable>::probe
   4: <rustc_infer::infer::freshen::TypeFreshener as rustc_middle::ty::fold::TypeFolder>::fold_ty
   5: <&rustc_middle::ty::list::List<rustc_middle::ty::subst::GenericArg> as rustc_middle::ty::fold::TypeFoldable>::fold_with::<rustc_infer::infer::freshen::TypeFreshener>
   6: <rustc_trait_selection::traits::select::SelectionContext>::select_from_obligation
   7: <rustc_trait_selection::traits::select::SelectionContext>::select
   8: <rustc_infer::infer::InferCtxtBuilder>::enter::<core::result::Result<rustc_middle::traits::ImplSource<()>, rustc_errors::ErrorReported>, rustc_trait_selection::traits::codegen::codegen_fulfill_obligation::{closure#0}>
   9: rustc_trait_selection::traits::codegen::codegen_fulfill_obligation
  10: rustc_data_structures::stack::ensure_sufficient_stack::<core::result::Result<rustc_middle::traits::ImplSource<()>, rustc_errors::ErrorReported>, rustc_query_system::query::plumbing::execute_job<rustc_query_impl::plumbing::QueryCtxt, (rustc_middle::ty::ParamEnv, rustc_middle::ty::sty::Binder<rustc_middle::ty::sty::TraitRef>), core::result::Result<rustc_middle::traits::ImplSource<()>, rustc_errors::ErrorReported>>::{closure#0}>
  11: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::codegen_fulfill_obligation, rustc_query_impl::plumbing::QueryCtxt>
  12: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::codegen_fulfill_obligation
  13: rustc_ty_utils::instance::inner_resolve_instance
  14: rustc_ty_utils::instance::resolve_instance
  15: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::resolve_instance, rustc_query_impl::plumbing::QueryCtxt>
  16: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::resolve_instance
  17: <rustc_middle::ty::instance::Instance>::resolve_opt_const_arg
  18: <rustc_middle::ty::context::TyCtxt>::const_eval_resolve
  19: <rustc_monomorphize::collector::MirNeighborCollector as rustc_middle::mir::visit::Visitor>::visit_constant
  20: <rustc_monomorphize::collector::MirNeighborCollector as rustc_middle::mir::visit::Visitor>::visit_operand
  21: rustc_monomorphize::collector::collect_neighbours
  22: rustc_monomorphize::collector::collect_items_rec
  23: rustc_monomorphize::collector::collect_items_rec
  24: rustc_monomorphize::collector::collect_items_rec
  25: rustc_monomorphize::collector::collect_items_rec
  26: rustc_monomorphize::collector::collect_items_rec
  27: rustc_monomorphize::collector::collect_items_rec
  28: rustc_monomorphize::collector::collect_items_rec
  29: rustc_monomorphize::collector::collect_items_rec
  30: rustc_monomorphize::collector::collect_items_rec
  31: rustc_monomorphize::collector::collect_items_rec
  32: rustc_monomorphize::collector::collect_items_rec
  33: rustc_monomorphize::collector::collect_items_rec
  34: rustc_monomorphize::collector::collect_items_rec
  35: rustc_monomorphize::collector::collect_items_rec
  36: rustc_monomorphize::collector::collect_items_rec
  37: rustc_monomorphize::collector::collect_items_rec
  38: rustc_monomorphize::collector::collect_items_rec
  39: rustc_monomorphize::collector::collect_items_rec
  40: rustc_monomorphize::collector::collect_items_rec
  41: rustc_monomorphize::collector::collect_items_rec
  42: rustc_monomorphize::collector::collect_items_rec
  43: rustc_monomorphize::collector::collect_items_rec
  44: rustc_monomorphize::collector::collect_items_rec
  45: rustc_monomorphize::collector::collect_items_rec
  46: rustc_monomorphize::collector::collect_items_rec
  47: rustc_monomorphize::collector::collect_items_rec
  48: rustc_monomorphize::collector::collect_items_rec
  49: rustc_monomorphize::collector::collect_items_rec
  50: rustc_monomorphize::collector::collect_items_rec
  51: rustc_monomorphize::collector::collect_items_rec
  52: rustc_monomorphize::collector::collect_items_rec
  53: rustc_monomorphize::collector::collect_items_rec
  54: rustc_monomorphize::collector::collect_items_rec
  55: rustc_monomorphize::collector::collect_items_rec
  56: rustc_monomorphize::collector::collect_items_rec
  57: rustc_monomorphize::collector::collect_items_rec
  58: rustc_monomorphize::collector::collect_items_rec
  59: rustc_monomorphize::collector::collect_items_rec
  60: rustc_monomorphize::collector::collect_items_rec
  61: rustc_monomorphize::collector::collect_items_rec
  62: rustc_monomorphize::collector::collect_items_rec
  63: rustc_monomorphize::collector::collect_items_rec
  64: rustc_monomorphize::collector::collect_items_rec
  65: rustc_monomorphize::collector::collect_items_rec
  66: rustc_monomorphize::collector::collect_items_rec
  67: rustc_monomorphize::collector::collect_items_rec
  68: rustc_monomorphize::collector::collect_items_rec
  69: rustc_monomorphize::collector::collect_items_rec
  70: rustc_monomorphize::collector::collect_items_rec
  71: rustc_monomorphize::collector::collect_items_rec
  72: rustc_monomorphize::collector::collect_items_rec
  73: rustc_monomorphize::collector::collect_items_rec
  74: rustc_monomorphize::collector::collect_items_rec
  75: rustc_monomorphize::collector::collect_items_rec
  76: rustc_monomorphize::collector::collect_items_rec
  77: rustc_monomorphize::collector::collect_items_rec
  78: rustc_monomorphize::collector::collect_items_rec
  79: rustc_monomorphize::collector::collect_items_rec
  80: rustc_monomorphize::collector::collect_items_rec
  81: rustc_monomorphize::collector::collect_items_rec
  82: rustc_monomorphize::collector::collect_items_rec
  83: rustc_monomorphize::collector::collect_items_rec
  84: rustc_monomorphize::collector::collect_items_rec
  85: rustc_monomorphize::collector::collect_items_rec
  86: rustc_monomorphize::collector::collect_items_rec
  87: rustc_monomorphize::collector::collect_items_rec
  88: rustc_monomorphize::collector::collect_items_rec
  89: rustc_monomorphize::collector::collect_items_rec
  90: rustc_monomorphize::collector::collect_items_rec
  91: rustc_monomorphize::collector::collect_items_rec
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[VictorKoenders]

Still ICE's on 1.59.0-nightly (fcef61230 2021-12-17)

[ZoeyR]

I created a minimal reproduction of the issue. This ICEs on stable as of 1.57

fn main() {
    let writer = WriteImpl;
    let mut encoder = EncoderImpl::<_>::new(writer);
    Item.encode(&mut encoder);
}

pub trait Encode {
    fn encode<E: Encoder>(&self, encoder: E);
}

pub trait Encoder {
    type W: Writer;

    fn writer(&mut self) -> &mut Self::W;
}

pub trait Writer {
    fn write(&mut self);
}

struct Item;

impl Encode for Item {
    fn encode<E: Encoder>(&self, mut encoder: E) {
        encoder.writer().write();
        self.encode(&mut encoder);
    }
}

struct EncoderImpl<W: Writer> {
    writer: W,
}

impl<W: Writer> EncoderImpl<W> {
    pub fn new(writer: W) -> EncoderImpl<W> {
        EncoderImpl { writer }
    }
}

impl<W: Writer> Encoder for EncoderImpl<W> {
    type W = W;

    fn writer(&mut self) -> &mut Self::W {
        &mut self.writer
    }
}

struct WriteImpl;

impl Writer for WriteImpl {
    fn write(&mut self) {}
}

impl<'a, T> Encoder for &'a mut T
where
    T: Encoder,
{
    type W = T::W;

    fn writer(&mut self) -> &mut Self::W {
        T::writer(self)
    }
}

The expectation is that the type checker should hit the recursion limit. In fact you can see this happen if you comment out the line encoder.writer().write();

[Eijebong]

@Aaron1011 I was told by @lqd that this should hopefully be fixed by #92210 which doesn't seem to be changing anything.

> rustc +fc922e0fe35a7aaa4bf5dbbe516ffd78dde591c2 a.rs
thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0', /cargo/registry/src/github.com-1ecc6299db9ec823/ena-0.14.0/src/snapshot_vec.rs:199:10
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

error: internal compiler error: unexpected panic

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

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 1.59.0-nightly (fc922e0fe 2022-01-02) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [codegen_fulfill_obligation] checking if `Writer` fulfills its obligations
#1 [resolve_instance] resolving instance `<_ as Writer>::write`
end of query stack

[est31]

Minimized a bit further:

fn main() {
    encode(&mut EncoderImpl);
}

pub trait Encoder {
    type W;

    fn writer(&self) -> Self::W;
}

fn encode<E: Encoder>(mut encoder: E) {
    encoder.writer();
    encode(&mut encoder);
}

struct EncoderImpl;

impl Encoder for EncoderImpl {
    type W = ();

    fn writer(&self) {}
}

impl<'a, T: Encoder> Encoder for &'a mut T {
    type W = T::W;

    fn writer(&self) -> Self::W {
        panic!()
    }
}

[lqd]

(That was an incorrect guess on my part: I've seen this query in other incremental issues recently, and this actually does not seem to be related to that at all)

[Eijebong]

Bisected to 50171c3 with cargo-bisect-rustc --end 73422130ee96c09e7214c876a3600ac1f32aa8c8 --start 9faa714154dbc03faa174a7d4f72d6bbbfd61f7c --regress ice and est31's example

[est31]

Auto merge of # 88563 - ehuss:update-cargo-books, r=ehuss

Are you sure you bisected correctly? A cargo update should not have introduced it, as the bug is reproducible without any cargo involvement at all.

But the ICE does seem to be a regression, as according to experiments on godbolt.org, it doesn't ICE on rustc 1.30.0, but does ICE on rustc 1.31.0 (both Zoey's shared snippet and my example).

• In rustc 1.30.0 there is no ICE, but an error
• In rustc 1.31.0 until 1.36.0 inclusive there is an ICE with the error message: 'called Option::unwrap() on a None value'
• In rustc 1.37.0 the ICE message is: 'could not lift for printing', src/libcore/option.rs:1034:5
• Starting with rustc 1.38.0 until 1.57.0 and current nightly the ICE message is: 'index out of bounds: the len is 0 but the index is 0'

[Eijebong]

Yeah the bisect is very weird. I tried running some versions manually that were reported as good by the tool and they still ICEd. I think --regress ice is broken

[matthiaskrgr]

Another reproducer from ./src/test/ui/closures/print/closure-print-generic-verbose-1.rs (needs --edition=2021 to crash)

fn to_fn_once<F:FnOnce()>(f: F) -> F { f }

fn f<T: std::fmt::Display>(y: T) {
    struct Foo<U: std::fmt::Display> {
        x: U
    };

    let foo =  Foo{ x: "x" };

    let c = to_fn_once(move|| {
        println!("{} {}", foo.x, y);
    });

    c();
    c();
    //~^ ERROR use of moved value
}


fn main() {
    f("S");
}