rustc panic when annotating incorrectly

[moshevds]

Code

Cargo.toml:

[package]
name = "rustc-panic-example"
version = "0.1.0"
edition = "2018"
[dependencies]
serde = { version = "1.0.127", features = ["derive"] }

src/main.rs:

use serde::Serialize;
#![allow(unreachable_code)]
#[derive(Serialize)]
#[allow(unreachable_code)]
struct Foo(());

Meta

rustc --version --verbose:

rustc 1.57.0-nightly (c1026539b 2021-10-15)
binary: rustc
commit-hash: c1026539bd22e9d070988deaa47b1360cbc76436
commit-date: 2021-10-15
host: x86_64-unknown-linux-gnu
release: 1.57.0-nightly
LLVM version: 13.0.0

Error output

thread 'rustc' panicked at 'Found outer attribute Attribute { kind: Normal(AttrItem { path: Path { span: src/main.rs:4:3: 4:8 (#0), segments: [PathSegment { ident: allow#0, id: NodeId(4294967040), args: None }], tokens: None }, args: Delimited(DelimSpan { open: src/main.rs:4:8: 4:9 (#0), close: src/main.rs:4:25: 4:26 (#0) }, Parenthesis, TokenStream([(Token(Token { kind: Ident("unreachable_code", false), span: src/main.rs:4:9: 4:25 (#0) }), Alone)])), tokens: None }, Some(LazyTokenStream(AttrAnnotatedTokenStream([(Token(Token { kind: Pound, span: src/main.rs:4:1: 4:2 (#0) }), Alone), (Delimited(DelimSpan { open: src/main.rs:4:2: 4:3 (#0), close: src/main.rs:4:26: 4:27 (#0) }, Bracket, AttrAnnotatedTokenStream([(Token(Token { kind: Ident("allow", false), span: src/main.rs:4:3: 4:8 (#0) }), Alone), (Delimited(DelimSpan { open: src/main.rs:4:8: 4:9 (#0), close: src/main.rs:4:25: 4:26 (#0) }, Paren, AttrAnnotatedTokenStream([(Token(Token { kind: Ident("unreachable_code", false), span: src/main.rs:4:9: 4:25 (#0) }), Alone)])), Alone)])), Alone)])))), id: AttrId(4), style: Outer, span: src/main.rs:4:1: 4:27 (#0) } after inner attrs [Attribute { kind: Normal(AttrItem { path: Path { span: src/main.rs:2:4: 2:9 (#0), segments: [PathSegment { ident: allow#0, id: NodeId(4294967040), args: None }], tokens: None }, args: Delimited(DelimSpan { open: src/main.rs:2:9: 2:10 (#0), close: src/main.rs:2:26: 2:27 (#0) }, Parenthesis, TokenStream([(Token(Token { kind: Ident("unreachable_code", false), span: src/main.rs:2:10: 2:26 (#0) }), Alone)])), tokens: None }, Some(LazyTokenStream(AttrAnnotatedTokenStream([(Token(Token { kind: Pound, span: src/main.rs:2:1: 2:2 (#0) }), Joint), (Token(Token { kind: Not, span: src/main.rs:2:2: 2:3 (#0) }), Alone), (Delimited(DelimSpan { open: src/main.rs:2:3: 2:4 (#0), close: src/main.rs:2:27: 2:28 (#0) }, Bracket, AttrAnnotatedTokenStream([(Token(Token { kind: Ident("allow", false), span: src/main.rs:2:4: 2:9 (#0) }), Alone), (Delimited(DelimSpan { open: src/main.rs:2:9: 2:10 (#0), close: src/main.rs:2:26: 2:27 (#0) }, Paren, AttrAnnotatedTokenStream([(Token(Token { kind: Ident("unreachable_code", false), span: src/main.rs:2:10: 2:26 (#0) }), Alone)])), Alone)])), Alone)])))), id: AttrId(2), style: Inner, span: src/main.rs:2:1: 2:28 (#0) }]', compiler/rustc_ast/src/tokenstream.rs:224:33

Backtrace

stack backtrace:
   0: rust_begin_unwind
             at /rustc/c1026539bd22e9d070988deaa47b1360cbc76436/library/std/src/panicking.rs:517:5
   1: core::panicking::panic_fmt
             at /rustc/c1026539bd22e9d070988deaa47b1360cbc76436/library/core/src/panicking.rs:100:14
   2: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &mut F>::call_once
   3: <core::iter::adapters::flatten::FlatMap<I,U,F> as core::iter::traits::iterator::Iterator>::next
   4: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter::SpecFromIter<T,I>>::from_iter
   5: rustc_ast::tokenstream::AttrAnnotatedTokenStream::to_tokenstream
   6: rustc_parse::prepend_attrs
   7: rustc_parse::nt_to_tokenstream
   8: <rustc_expand::proc_macro::ProcMacroDerive as rustc_expand::base::MultiItemModifier>::expand
   9: rustc_expand::expand::MacroExpander::fully_expand_fragment
  10: rustc_expand::expand::MacroExpander::expand_crate
  11: rustc_session::utils::<impl rustc_session::session::Session>::time
  12: rustc_interface::passes::configure_and_expand
  13: rustc_interface::queries::Queries::expansion
  14: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  15: rustc_span::with_source_map
  16: scoped_tls::ScopedKey<T>::set

[ben0x539]

Is this similar to #88938?

[EliseZeroTwo]

This was fixed by #90267

[JohnTitor]

Triage: Fixed by the above PR and it has a regression test, closing.