Greek question mark causes ICE

[Alcaro]

https://godbolt.org/z/Yd76o7Ybq
https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=9cf4205afdba1abc79336f966f95f6ff

Code

pub fn square(num: i32) -> i32 {
    num * num;
}

Note: that's a greek question mark, not a semicolon

Meta

rustc --version --verbose:

rustc 1.77.0 (aedd173a2 2024-03-17)
binary: rustc
commit-hash: aedd173a2c086e558c2b66d3743b344f977621a7
commit-date: 2024-03-17
host: x86_64-unknown-linux-gnu
release: 1.77.0
LLVM version: 17.0.6
Compiler returned: 0

Error output

error: unknown start of token: \u{37e}
 --> <source>:2:14
  |
2 |     num * num;
  |              ^
  |
help: Unicode character ';' (Greek Question Mark) looks like ';' (Semicolon), but it is not
  |
2 |     num * num;
  |              ~

thread 'rustc' panicked at compiler/rustc_span/src/lib.rs:2019:17:
assertion failed: bpos.to_u32() >= mbc.pos.to_u32() + mbc.bytes as u32
stack backtrace:
   0:     0x7fb2cd416d16 - std::backtrace_rs::backtrace::libunwind::trace::h92ba5ac126ecc5ad
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5

Rest of the output

   1:     0x7fb2cd416d16 - std::backtrace_rs::backtrace::trace_unsynchronized::hfaa118b6e3a8f31a
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fb2cd416d16 - std::sys_common::backtrace::_print_fmt::h2075f185adf13bbd
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7fb2cd416d16 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h9c4bd387f9f3f544
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fb2cd469770 - core::fmt::rt::Argument::fmt::h018ecebdf268b5bb
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/core/src/fmt/rt.rs:142:9
   5:     0x7fb2cd469770 - core::fmt::write::h938c332fdab924eb
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/core/src/fmt/mod.rs:1120:17
   6:     0x7fb2cd40a58f - std::io::Write::write_fmt::h4a694b02e44e6363
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/io/mod.rs:1846:15
   7:     0x7fb2cd416af4 - std::sys_common::backtrace::_print::h3595c0f4303f3ccd
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7fb2cd416af4 - std::sys_common::backtrace::print::ha888e6736b0bc71f
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7fb2cd419887 - std::panicking::default_hook::{{closure}}::he19a7f79f7beab5e
  10:     0x7fb2cd4195e9 - std::panicking::default_hook::h67efe04e9a5d446e
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/panicking.rs:292:9
  11:     0x7fb2ca3af6bc - std[c78d3cd131ec7074]::panicking::update_hook::<alloc[4e128ca7a2328977]::boxed::Box<rustc_driver_impl[f73d4ac0dd51449f]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7fb2cd419fd6 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h9c9759b104a0af15
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/alloc/src/boxed.rs:2029:9
  13:     0x7fb2cd419fd6 - std::panicking::rust_panic_with_hook::h49021cdbc4b22349
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/panicking.rs:785:13
  14:     0x7fb2cd419ce9 - std::panicking::begin_panic_handler::{{closure}}::hfbf601f3d8c62d13
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/panicking.rs:651:13
  15:     0x7fb2cd417216 - std::sys_common::backtrace::__rust_end_short_backtrace::h98dd020b6e913806
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7fb2cd419a74 - rust_begin_unwind
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/panicking.rs:647:5
  17:     0x7fb2cd465e75 - core::panicking::panic_fmt::h0d3f1893e38be419
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/core/src/panicking.rs:72:14
  18:     0x7fb2cd465f33 - core::panicking::panic::h59297120e85ea178
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/core/src/panicking.rs:144:5
  19:     0x7fb2cbd584e5 - <rustc_span[9a816cd1dc398d83]::source_map::SourceMap>::lookup_char_pos
  20:     0x7fb2cc4fa5df - <rustc_errors[210c88760d7272a3]::emitter::FileWithAnnotatedLines>::collect_annotations
  21:     0x7fb2cc5b97a6 - <rustc_errors[210c88760d7272a3]::emitter::HumanEmitter>::emit_messages_default_inner::{closure#0}
  22:     0x7fb2cc2c88c0 - <rustc_errors[210c88760d7272a3]::emitter::HumanEmitter>::emit_messages_default
  23:     0x7fb2cc2c7b7a - <rustc_errors[210c88760d7272a3]::emitter::HumanEmitter as rustc_errors[210c88760d7272a3]::emitter::Emitter>::emit_diagnostic
  24:     0x7fb2cc4f37e6 - <rustc_errors[210c88760d7272a3]::DiagCtxtInner>::emit_diagnostic::{closure#2}
  25:     0x7fb2cc4f2113 - rustc_interface[aa0080c74e239226]::callbacks::track_diagnostic::{closure#0}
  26:     0x7fb2cc4f13d5 - rustc_interface[aa0080c74e239226]::callbacks::track_diagnostic
  27:     0x7fb2cc4f067b - <rustc_errors[210c88760d7272a3]::DiagCtxtInner>::emit_diagnostic
  28:     0x7fb2cc612ed2 - <rustc_errors[210c88760d7272a3]::DiagCtxt>::emit_diagnostic
  29:     0x7fb2cc62fa17 - <rustc_span[9a816cd1dc398d83]::ErrorGuaranteed as rustc_errors[210c88760d7272a3]::diagnostic_builder::EmissionGuarantee>::emit_producing_guarantee
  30:     0x7fb2cbaaa02f - <rustc_hir_typeck[c9a6c5868c179bee]::fn_ctxt::FnCtxt>::check_block_with_expected
  31:     0x7fb2cc0853a2 - <rustc_hir_typeck[c9a6c5868c179bee]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  32:     0x7fb2cbef178e - rustc_hir_typeck[c9a6c5868c179bee]::check::check_fn
  33:     0x7fb2cc077f97 - rustc_hir_typeck[c9a6c5868c179bee]::typeck
  34:     0x7fb2cc0772b9 - rustc_query_impl[d4fff4934001d2d8]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d4fff4934001d2d8]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[b1822cca650065f0]::query::erase::Erased<[u8; 8usize]>>
  35:     0x7fb2cb8f73e2 - rustc_query_system[a6ec2c612bc0f18a]::query::plumbing::try_execute_query::<rustc_query_impl[d4fff4934001d2d8]::DynamicConfig<rustc_query_system[a6ec2c612bc0f18a]::query::caches::VecCache<rustc_span[9a816cd1dc398d83]::def_id::LocalDefId, rustc_middle[b1822cca650065f0]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[d4fff4934001d2d8]::plumbing::QueryCtxt, false>
  36:     0x7fb2cb8f7010 - rustc_query_impl[d4fff4934001d2d8]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  37:     0x7fb2cb8f4fb7 - rustc_hir_analysis[c457423c9d2f4f1c]::check_crate
  38:     0x7fb2cbfc93e6 - rustc_interface[aa0080c74e239226]::passes::analysis
  39:     0x7fb2cbfc8ddf - rustc_query_impl[d4fff4934001d2d8]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d4fff4934001d2d8]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[b1822cca650065f0]::query::erase::Erased<[u8; 1usize]>>
  40:     0x7fb2cc027034 - rustc_query_system[a6ec2c612bc0f18a]::query::plumbing::try_execute_query::<rustc_query_impl[d4fff4934001d2d8]::DynamicConfig<rustc_query_system[a6ec2c612bc0f18a]::query::caches::SingleCache<rustc_middle[b1822cca650065f0]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[d4fff4934001d2d8]::plumbing::QueryCtxt, false>
  41:     0x7fb2cc026e79 - rustc_query_impl[d4fff4934001d2d8]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  42:     0x7fb2cc2ea78b - rustc_interface[aa0080c74e239226]::interface::run_compiler::<core[853b3d1bf84aeb53]::result::Result<(), rustc_span[9a816cd1dc398d83]::ErrorGuaranteed>, rustc_driver_impl[f73d4ac0dd51449f]::run_compiler::{closure#0}>::{closure#0}
  43:     0x7fb2cc5382f1 - std[c78d3cd131ec7074]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[aa0080c74e239226]::util::run_in_thread_with_globals<rustc_interface[aa0080c74e239226]::interface::run_compiler<core[853b3d1bf84aeb53]::result::Result<(), rustc_span[9a816cd1dc398d83]::ErrorGuaranteed>, rustc_driver_impl[f73d4ac0dd51449f]::run_compiler::{closure#0}>::{closure#0}, core[853b3d1bf84aeb53]::result::Result<(), rustc_span[9a816cd1dc398d83]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[853b3d1bf84aeb53]::result::Result<(), rustc_span[9a816cd1dc398d83]::ErrorGuaranteed>>
  44:     0x7fb2cc53814f - <<std[c78d3cd131ec7074]::thread::Builder>::spawn_unchecked_<rustc_interface[aa0080c74e239226]::util::run_in_thread_with_globals<rustc_interface[aa0080c74e239226]::interface::run_compiler<core[853b3d1bf84aeb53]::result::Result<(), rustc_span[9a816cd1dc398d83]::ErrorGuaranteed>, rustc_driver_impl[f73d4ac0dd51449f]::run_compiler::{closure#0}>::{closure#0}, core[853b3d1bf84aeb53]::result::Result<(), rustc_span[9a816cd1dc398d83]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[853b3d1bf84aeb53]::result::Result<(), rustc_span[9a816cd1dc398d83]::ErrorGuaranteed>>::{closure#1} as core[853b3d1bf84aeb53]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  45:     0x7fb2cd423675 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h4f08d401a486e446
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/alloc/src/boxed.rs:2015:9
  46:     0x7fb2cd423675 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h3476dfcdba628abc
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/alloc/src/boxed.rs:2015:9
  47:     0x7fb2cd423675 - std::sys::pal::unix::thread::Thread::new::thread_start::h2770ac7f8882db09
                               at /rustc/aedd173a2c086e558c2b66d3743b344f977621a7/library/std/src/sys/pal/unix/thread.rs:108:17
  48:     0x7fb2c7494ac3 - <unknown>
  49:     0x7fb2c7526850 - <unknown>
  50:                0x0 - <unknown>

error: 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 1.77.0 (aedd173a2 2024-03-17) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=1 -C llvm-args=--x86-asm-syntax=intel --crate-type rlib

query stack during panic:
#0 [typeck] type-checking `square`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0308`.
Compiler returned: 101

Backtrace

Don't know how to do that on godbolt

[jieyouxu]

This ICE'd as early as 1.38.0 lol https://godbolt.org/z/4o1P69Ed1

[matthiaskrgr]

Greek Question Mark unwraps so hard the compiler crashes!