ICE: compiler/rustc_middle/src/hir/map/mod.rs:810:21: no name for param # [ doc ( alias = "false" ) ] DiagnosticBuilder (hir_id=HirId { owner: DefId(0:4 ~ mutant[8787]::StructuredDiagnostic::extended), local_id: 1 })

[Cancelll]

Code

trait StructuredDiagnostic {
fn extended (# [ doc ( alias = "false" ) ] DiagnosticBuilder){
}
}

Meta

rustc --version --verbose:

rustc 1.54.0-nightly (0a8629bff 2021-06-11)
binary: rustc
commit-hash: 0a8629bff642c3c3b84bb644c0099194f063b627
commit-date: 2021-06-11
host: x86_64-unknown-linux-gnu
release: 1.54.0-nightly
LLVM version: 12.0.1

Error output

error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
 --> mutant.rs:2:14
  |
2 | fn extended (# [ doc ( alias = "false" ) ] DiagnosticBuilder){
  |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0412]: cannot find type `DiagnosticBuilder` in this scope
 --> mutant.rs:2:44
  |
2 | fn extended (# [ doc ( alias = "false" ) ] DiagnosticBuilder){
  |                                            ^^^^^^^^^^^^^^^^^ not found in this scope

warning: anonymous parameters are deprecated and will be removed in the next edition.
 --> mutant.rs:2:44
  |
2 | fn extended (# [ doc ( alias = "false" ) ] DiagnosticBuilder){
  |                                            ^^^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: DiagnosticBuilder`
  |
  = note: `#[warn(anonymous_parameters)]` on by default
  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2018 edition!
  = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>

error: internal compiler error: compiler/rustc_middle/src/hir/map/mod.rs:810:21: no name for param # [ doc ( alias = "false" ) ] DiagnosticBuilder (hir_id=HirId { owner: DefId(0:4 ~ mutant[8787]::StructuredDiagnostic::extended), local_id: 1 })

thread 'rustc' panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1007:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

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 1.54.0-nightly (0a8629bff 2021-06-11) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=3 -Z new-llvm-pass-manager=yes -Z unsound-mir-opts=yes -Z polonius=yes -Z polymorphize=yes -C debuginfo=2 -C opt-level=3 --crate-type staticlib

query stack during panic:
#0 [check_mod_attrs] checking attributes in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 3 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0412`.

Backtrace

error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
 --> mutant.rs:2:14
  |
2 | fn extended (# [ doc ( alias = "false" ) ] DiagnosticBuilder){
  |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0412]: cannot find type `DiagnosticBuilder` in this scope
 --> mutant.rs:2:44
  |
2 | fn extended (# [ doc ( alias = "false" ) ] DiagnosticBuilder){
  |                                            ^^^^^^^^^^^^^^^^^ not found in this scope

warning: anonymous parameters are deprecated and will be removed in the next edition.
 --> mutant.rs:2:44
  |
2 | fn extended (# [ doc ( alias = "false" ) ] DiagnosticBuilder){
  |                                            ^^^^^^^^^^^^^^^^^ help: try naming the parameter or explicitly ignoring it: `_: DiagnosticBuilder`
  |
  = note: `#[warn(anonymous_parameters)]` on by default
  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2018 edition!
  = note: for more information, see issue #41686 <https://github.com/rust-lang/rust/issues/41686>

error: internal compiler error: compiler/rustc_middle/src/hir/map/mod.rs:810:21: no name for param # [ doc ( alias = "false" ) ] DiagnosticBuilder (hir_id=HirId { owner: DefId(0:4 ~ mutant[8787]::StructuredDiagnostic::extended), local_id: 1 })

thread 'rustc' panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1007:9
stack backtrace:
   0: std::panicking::begin_panic
   1: std::panic::panic_any
   2: rustc_errors::HandlerInner::bug
   3: rustc_errors::Handler::bug
   4: rustc_middle::ty::context::tls::with_opt
   5: rustc_middle::util::bug::opt_span_bug_fmt
   6: rustc_middle::util::bug::bug_fmt
   7: rustc_middle::hir::map::Map::name
   8: rustc_passes::check_attr::CheckAttrVisitor::check_doc_alias_value
   9: rustc_passes::check_attr::CheckAttrVisitor::check_attributes
  10: rustc_hir::intravisit::walk_body
  11: rustc_hir::intravisit::walk_fn
  12: rustc_hir::intravisit::walk_trait_item
  13: rustc_middle::hir::map::Map::visit_item_likes_in_module
  14: rustc_passes::check_attr::check_mod_attrs
  15: rustc_query_system::query::plumbing::get_query_impl
  16: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_mod_attrs
  17: std::panic::catch_unwind
  18: rustc_session::utils::<impl rustc_session::session::Session>::time
  19: rustc_interface::passes::analysis
  20: rustc_query_system::query::plumbing::get_query_impl
  21: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  22: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  23: rustc_span::with_source_map
  24: rustc_interface::interface::create_compiler_and_run
  25: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 1.54.0-nightly (0a8629bff 2021-06-11) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=3 -Z new-llvm-pass-manager=yes -Z unsound-mir-opts=yes -Z polonius=yes -Z polymorphize=yes -C debuginfo=2 -C opt-level=3 --crate-type staticlib

query stack during panic:
#0 [check_mod_attrs] checking attributes in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 3 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0412`.

[steffahn]

ICE only appears since 1.52. @rustbot label regression-from-stable-to-stable

[steffahn]

Better-looking code example

trait Trait {
    fn method(#[doc(alias = "m")] _n: i32) {}
}

Bisection points to 9503ea1

Rollup of 11 pull requests

Successful merges:

 - #80523 (#[doc(inline)] sym_generated)
 - #80920 (Visit more targets when validating attributes)
 - #81720 (Updated smallvec version due to RUSTSEC-2021-0003)
 - #81891 ([rustdoc-json] Make `header` a vec of modifiers, and FunctionPointer consistent)
 - #81912 (Implement the precise analysis pass for lint `disjoint_capture_drop_reorder`)
 - #81914 (Fixing bad suggestion for `_` in `const` type when a function #81885)
 - #81919 (BTreeMap: fix internal comments)
 - #81927 (Add a regression test for #32498)
 - #81965 (Fix MIR pretty printer for non-local DefIds)
 - #82029 (Use debug log level for developer oriented logs)
 - #82056 (fix ice (#82032))

[steffahn]

Reading the descriptions, I’d guess most likely #80920, cc @rylev.

[rylev]

This is indeed caused by #80920 since we're now checking parameters unlike before. The issue is in when checking that a doc alias is not the same name as the thing it is aliasing. The call to self.tcx.hir().name(hir_id); panics because there is no name for a param.

The question I have is whether we should support params for doc aliases. I didn't find anything in the tracking issue to indicate that it was supposed to be supported, and I personally don't think it makes sense. If we decide to not support doc aliases for params, then it should be an easy change to check_doc_alias_value to error when target is a rustc_hir::Target::Param.

cc @GuillaumeGomez

[GuillaumeGomez]

Doc aliases are only supported for items showing up in doc search, function parameters don't, so in this case, it should error on the doc alias attribute.

[GuillaumeGomez]

Do you want to send a fix or should I?

[rylev]

@GuillaumeGomez I'll submit a fix.

[GuillaumeGomez]

Thanks! Please ping me on it (and don't forget to add a test for it too ;) ).