rust/compiler/rustc_parse/src/parser
Nicholas Nethercote 260ae70140 Overhaul how stashed diagnostics work, again.
Stashed errors used to be counted as errors, but could then be
cancelled, leading to `ErrorGuaranteed` soundness holes. #120828 changed
that, closing the soundness hole. But it introduced other difficulties
because you sometimes have to account for pending stashed errors when
making decisions about whether errors have occured/will occur and it's
easy to overlook these.

This commit aims for a middle ground.
- Stashed errors (not warnings) are counted immediately as emitted
  errors, avoiding the possibility of forgetting to consider them.
- The ability to cancel (or downgrade) stashed errors is eliminated, by
  disallowing the use of `steal_diagnostic` with errors, and introducing
  the more restrictive methods `try_steal_{modify,replace}_and_emit_err`
  that can be used instead.

Other things:
- `DiagnosticBuilder::stash` and `DiagCtxt::stash_diagnostic` now both
  return `Option<ErrorGuaranteed>`, which enables the removal of two
  `delayed_bug` calls and one `Ty::new_error_with_message` call. This is
  possible because we store error guarantees in
  `DiagCtxt::stashed_diagnostics`.
- Storing the guarantees also saves us having to maintain a counter.
- Calls to the `stashed_err_count` method are no longer necessary
  alongside calls to `has_errors`, which is a nice simplification, and
  eliminates two more `span_delayed_bug` calls and one FIXME comment.
- Tests are added for three of the four fixed PRs mentioned below.
- `issue-121108.rs`'s output improved slightly, omitting a non-useful
  error message.

Fixes #121451.
Fixes #121477.
Fixes #121504.
Fixes #121508.
2024-02-29 11:08:27 +11:00
..
attr_wrapper.rs Rename Parser::span_diagnostic as Parser::dcx. 2023-12-18 16:06:21 +11:00
attr.rs Rename DiagnosticBuilder as Diag. 2024-02-28 08:55:35 +11:00
diagnostics.rs Rename DiagnosticBuilder as Diag. 2024-02-28 08:55:35 +11:00
expr.rs Overhaul how stashed diagnostics work, again. 2024-02-29 11:08:27 +11:00
generics.rs Remove unnecessary .to_string()/.as_str()s 2024-02-02 15:16:05 -08:00
item.rs Add ErrorGuaranteed to ast::ExprKind::Err 2024-02-25 22:24:31 +01:00
mod.rs Rename DiagnosticBuilder as Diag. 2024-02-28 08:55:35 +11:00
nonterminal.rs Add newtype for raw idents 2024-02-20 13:13:29 +00:00
pat.rs Rename DiagnosticBuilder as Diag. 2024-02-28 08:55:35 +11:00
path.rs Add newtype for raw idents 2024-02-20 13:13:29 +00:00
stmt.rs Rename DiagnosticBuilder as Diag. 2024-02-28 08:55:35 +11:00
ty.rs Rollup merge of #121060 - clubby789:bool-newtypes, r=cjgillot 2024-02-25 17:05:20 +01:00