Thread 'rustc' panicked at 'expected exactly one expression'

[ZhangZhuoSJTU]

Code

#[e]fn e<>(){0=#[test]0

md5 of poc.rs: c06a315316d866befd0e986395948a9b

Meta

This bug is tested with nightly, beta, and stable versions.

rustc --version --verbose:

➜  playground rustc --version --verbose
rustc 1.51.0-nightly (23adf9fd8 2021-02-05)
binary: rustc
commit-hash: 23adf9fd843da7a3394c824b056f93151aaa40ad
commit-date: 2021-02-05
host: x86_64-unknown-linux-gnu
release: 1.51.0-nightly
LLVM version: 11.0.1

rustc 1.50.0-beta.8 (1cd030396 2021-01-20)
binary: rustc
commit-hash: 1cd0303963629f317a08e7e52162ccca7232ae7f
commit-date: 2021-01-20
host: x86_64-unknown-linux-gnu
release: 1.50.0-beta.8

rustc 1.49.0 (e1884a8e3 2020-12-29)
binary: rustc
commit-hash: e1884a8e3c3e813aada8254edfa120e85bf5ffca
commit-date: 2020-12-29
host: x86_64-unknown-linux-gnu
release: 1.49.0

Error output

This output is from nightly version

➜  playground rustc poc.rs
error: this file contains an unclosed delimiter
 --> out.rs:1:25
  |
1 | #[e]fn e<>(){0=#[test]0
  |             -           ^
  |             |
  |             unclosed delimiter

error[E0658]: attributes on expressions are experimental
 --> out.rs:1:16
  |
1 | #[e]fn e<>(){0=#[test]0
  |                ^^^^^^^
  |
  = note: see issue #15701 <https://github.com/rust-lang/rust/issues/15701> for more information
  = help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

thread 'rustc' panicked at 'expected exactly one expression', compiler/rustc_expand/src/expand.rs:277:30
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 1.51.0-nightly (23adf9fd8 2021-02-05) running on x86_64-unknown-linux-gnu

query stack during panic:
end of query stack
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0658`.

Backtrace

➜  playground RURUST_BACKTRACE=1 rustc poc.rs
error: this file contains an unclosed delimiter
 --> out.rs:1:25
  |
1 | #[e]fn e<>(){0=#[test]0
  |             -           ^
  |             |
  |             unclosed delimiter

error[E0658]: attributes on expressions are experimental
 --> out.rs:1:16
  |
1 | #[e]fn e<>(){0=#[test]0
  |                ^^^^^^^
  |
  = note: see issue #15701 <https://github.com/rust-lang/rust/issues/15701> for more information
  = help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

thread 'rustc' panicked at 'expected exactly one expression', compiler/rustc_expand/src/expand.rs:277:30
stack backtrace:
   0: rust_begin_unwind
             at /rustc/23adf9fd843da7a3394c824b056f93151aaa40ad/library/std/src/panicking.rs:493:5
   1: core::panicking::panic_fmt
             at /rustc/23adf9fd843da7a3394c824b056f93151aaa40ad/library/core/src/panicking.rs:92:14
   2: core::option::expect_failed
             at /rustc/23adf9fd843da7a3394c824b056f93151aaa40ad/library/core/src/option.rs:1292:5
   3: rustc_expand::expand::AstFragmentKind::expect_from_annotatables
   4: rustc_expand::expand::MacroExpander::fully_expand_fragment
   5: rustc_expand::expand::MacroExpander::expand_crate
   6: rustc_session::utils::<impl rustc_session::session::Session>::time
   7: rustc_interface::passes::configure_and_expand_inner
   8: rustc_interface::passes::configure_and_expand::{{closure}}
   9: rustc_data_structures::box_region::PinnedGenerator<I,A,R>::new
  10: rustc_interface::passes::configure_and_expand
  11: rustc_interface::queries::Queries::expansion
  12: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  13: rustc_span::with_source_map
  14: rustc_interface::interface::create_compiler_and_run
  15: rustc_span::with_session_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose 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 1.51.0-nightly (23adf9fd8 2021-02-05) running on x86_64-unknown-linux-gnu

query stack during panic:
end of query stack
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0658`.

[osa1]

Possibly a duplicate of #80251.

[petrochenkov]

Closing as a duplicate of #80251.