ICE: Missing span for DefIndex(3) in compiler/rustc_metadata/src/rmeta/decoder.rs:749

[dima74]

Code

After cargo new test-project:

• lib.rs:

macro_rules! foo_ { () => {}; }
use foo_ as foo;

• main.rs:

#[macro_use]
extern crate test_project;

fn main() {
    foo!();
}

Meta

rustc --version --verbose:

rustc 1.50.0-nightly (f76ecd066 2020-12-15)
binary: rustc
commit-hash: f76ecd0668fcdb289456cdc72a39ad15467cc454
commit-date: 2020-12-15
host: x86_64-unknown-linux-gnu
release: 1.50.0-nightly

Reproducible on stable 1.48 as well

Error output

   Compiling test-project v0.1.0
warning: unused macro definition
 --> src/lib.rs:1:1
  |
1 | macro_rules! foo_ { () => {}; }
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_macros)]` on by default

warning: unused import: `foo_ as foo`
 --> src/lib.rs:2:5
  |
2 | use foo_ as foo;
  |     ^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: 2 warnings emitted

thread 'rustc' panicked at 'Missing span for DefIndex(3)', compiler/rustc_metadata/src/rmeta/decoder.rs:749:32
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 1.50.0-nightly (f76ecd066 2020-12-15) running on x86_64-unknown-linux-gnu

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

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

query stack during panic:
end of query stack
error: could not compile `test-project`

Backtrace

stack backtrace:
   0: rust_begin_unwind
             at /rustc/f76ecd0668fcdb289456cdc72a39ad15467cc454/library/std/src/panicking.rs:493:5
   1: std::panicking::begin_panic_fmt
             at /rustc/f76ecd0668fcdb289456cdc72a39ad15467cc454/library/std/src/panicking.rs:435:5
   2: rustc_metadata::rmeta::decoder::<impl rustc_metadata::creader::CrateMetadataRef>::get_span::{{closure}}
   3: rustc_metadata::rmeta::decoder::cstore_impl::<impl rustc_metadata::creader::CStore>::load_macro_untracked
   4: rustc_resolve::build_reduced_graph::<impl rustc_resolve::Resolver>::get_macro_by_def_id
   5: rustc_resolve::macros::<impl rustc_resolve::Resolver>::resolve_macro_path
   6: rustc_resolve::macros::<impl rustc_expand::base::ResolverExpand for rustc_resolve::Resolver>::resolve_macro_invocation
   7: rustc_expand::expand::MacroExpander::fully_expand_fragment
   8: rustc_expand::expand::MacroExpander::expand_crate
   9: rustc_session::utils::<impl rustc_session::session::Session>::time
  10: rustc_interface::passes::configure_and_expand_inner
  11: rustc_interface::passes::configure_and_expand::{{closure}}
  12: rustc_data_structures::box_region::PinnedGenerator<I,A,R>::new
  13: rustc_interface::passes::configure_and_expand
  14: rustc_interface::queries::Queries::expansion
  15: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  16: rustc_span::with_source_map
  17: rustc_interface::interface::create_compiler_and_run
  18: scoped_tls::ScopedKey<T>::set

[durka]

Things that make the ICE go away:

1. Add #[macro_export] to the lib crate (compiles successfully)
2. Change the edition to 2015 when compiling the lib crate (errors on the use)

N.B. Changing from foo!() to foo_!() in the bin crate produces a different ICE.

[Alexendoo]

No longer ICEs since #88019