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using pub macro_rules outside of the crate ICEs with Missing span for DefIndex(3) #83641
Description
using pub_macro_rules on the latest nightly, i get this compiler panic.
index varies according to the code that's running as you might expect
Code
in a project called 'repro'
main.rs:
fn main() {
repro::fail!(recv);
}lib.rs:
#![feature(pub_macro_rules)]
pub macro_rules! fail {
($x:expr) => { $x }
}Meta
> cargo version --verbose
cargo 1.52.0-nightly (90691f2bf 2021-03-16)
release: 1.52.0
commit-hash: 90691f2bfe9a50291a98983b1ed2feab51d5ca55
commit-date: 2021-03-16
Error output
> RUST_BACKTRACE=1 cargo test
Compiling repro v0.5.0 (/home/james/code/irrustible/repro)
thread 'rustc' panicked at 'Missing span for DefIndex(3)', compiler/rustc_metadata/src/rmeta/decoder.rs:715:32
stack backtrace:
0: rust_begin_unwind
at /rustc/07e0e2ec268c140e607e1ac7f49f145612d0f597/library/std/src/panicking.rs:493:5
1: std::panicking::begin_panic_fmt
at /rustc/07e0e2ec268c140e607e1ac7f49f145612d0f597/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
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 1.53.0-nightly (07e0e2ec2 2021-03-24) running on x86_64-unknown-linux-musl
note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C incremental -C target-feature=-crt-static
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
end of query stack
error: could not compile `repro`
To learn more, run the command again with --verbose.
Activity
[-]using pub macro_rules outside of the crate segfaults with `Missing span for DefIndex(3)`[/-][+]using pub macro_rules outside of the crate ICEs with `Missing span for DefIndex(3)`[/+]jjl commentedon Mar 29, 2021
Note that I was not able to reproduce this without using a main.rs or test file, which is why i think it's about being used outside of the crate.
jjl commentedon Mar 29, 2021
It appears to be because it's trying to give me a helpful error for the variable i never defined that i'm passing as an argument to the macro
petrochenkov commentedon Mar 29, 2021
Unfortunately, the feature was merged in half-implemented state.
@spastorino @nikomatsakis I mentioned in #78166 that cross-crate cases need to be tested/fixed, but #82296 was merged as is instead.
spastorino commentedon Mar 30, 2021
@petrochenkov yeah, I understood that and I was going to work on this problem. At some point these changes that were supposed to be included in edition 2021, are now (if I'm not wrong) not going to be included so I ended de-priorizing this work.
Please @nikomatsakis correct me if I'm wrong. We may want or to have this open and assigned to me or @petrochenkov you can feel free to fix this too or we can also revert the included PR too.
nikomatsakis commentedon Mar 30, 2021
I think at this point we should just revert the PR. My sense was that we never quite got the design resolved to the point where we were confident we were going to go forward with it. Another option would be to add the "half-baked" flag that gives warnings when you use it, of course.
jjl commentedon Mar 31, 2021
I think the 'half-baked' flag is still worth having, but it would be helpful if it noted that out of crate use is unlikely to work.
nikomatsakis commentedon Mar 31, 2021
My personal take is that if nobody is actively pursuing this design (and I think nobody is) we should just revert the PR.
spastorino commentedon Mar 31, 2021
Have opened a PR #83713 to revert this. As I've commented there, I guess if someone has time to make it work cross crates we could add the feature again with cross crate support.
Add 83641
Auto merge of rust-lang#83713 - spastorino:revert-pub-macro-rules, r=…
JohnTitor commentedon Apr 29, 2021
Triage: ICE has gone by #83713, I'm going to mark this as
E-needs-testsince it seems that PR doesn't have a regression test for the issue.nikomatsakis commentedon Apr 29, 2021
Hmm, I'm not sure if we need a regression test for this -- it's a regression test for a feature that no longer exists and may well never be added again -- but I guess it doesn't hurt.
JohnTitor commentedon Apr 29, 2021
Ah, good call, I'm not familiar with the context. @nikomatsakis feel free to just close if you like :)
spastorino commentedon Apr 29, 2021
Yes, this can be closed now.