Improve codegen diagnostic handling
Clarify the workings of the temporary `Diagnostic` type used to send diagnostics from codegen threads to the main thread.
r? `@estebank`
First, introduce a typedef `DiagnosticArgMap`.
Second, make the `args` field public, and remove the `args` getter and
`replace_args` setter. These were necessary previously because the getter
had a `#[allow(rustc::potential_query_instability)]` attribute, but that
was removed in #120931 when the args were changed from `FxHashMap` to
`FxIndexMap`. (All the other `Diagnostic` fields are public.)
Currently `emit_stashed_diagnostic` is called from four(!) different
places: `print_error_count`, `DiagCtxtInner::drop`, `abort_if_errors`,
and `compile_status`.
And `flush_delayed` is called from two different places:
`DiagCtxtInner::drop` and `Queries`.
This is pretty gross! Each one should really be called from a single
place, but there's a bunch of entanglements. This commit cleans up this
mess.
Specifically, it:
- Removes all the existing calls to `emit_stashed_diagnostic`, and adds
a single new call in `finish_diagnostics`.
- Removes the early `flush_delayed` call in `codegen_and_build_linker`,
replacing it with a simple early return if delayed bugs are present.
- Changes `DiagCtxtInner::drop` and `DiagCtxtInner::flush_delayed` so
they both assert that the stashed diagnostics are empty (i.e.
processed beforehand).
- Changes `interface::run_compiler` so that any errors emitted during
`finish_diagnostics` (i.e. late-emitted stashed diagnostics) are
counted and cannot be overlooked. This requires adding
`ErrorGuaranteed` return values to several functions.
- Removes the `stashed_err_count` call in `analysis`. This is possible
now that we don't have to worry about calling `flush_delayed` early
from `codegen_and_build_linker` when stashed diagnostics are pending.
- Changes the `span_bug` case in `handle_tuple_field_pattern_match` to a
`delayed_span_bug`, because it now can be reached due to the removal
of the `stashed_err_count` call in `analysis`.
- Slightly changes the expected output of three tests. If no errors are
emitted but there are delayed bugs, the error count is no longer
printed. This is because delayed bugs are now always printed after the
error count is printed (or not printed, if the error count is zero).
There is a lot going on in this commit. It's hard to break into smaller
pieces because the existing code is very tangled. It took me a long time
and a lot of effort to understand how the different pieces interact, and
I think the new code is a lot simpler and easier to understand.
Currently `has_errors` excludes lint errors. This commit changes it to
include lint errors.
The motivation for this is that for most places it doesn't matter
whether lint errors are included or not. But there are multiple places
where they must be includes, and only one place where they must not be
included. So it makes sense for `has_errors` to do the thing that fits
the most situations, and the new `has_errors_excluding_lint_errors`
method in the one exceptional place.
The same change is made for `err_count`. Annoyingly, this requires the
introduction of `err_count_excluding_lint_errs` for one place, to
preserve existing error printing behaviour. But I still think the change
is worthwhile overall.
Because:
- `diagnostic_builder.rs` is small (282 lines),
- `Diagnostic` and `DiagnosticBuilder` are closely related types, and
- there's already an `impl DiagnosticBuilder` block in `diagnostic.rs`.
At the same time, reorder a few of things already in `diagnostic.rs`,
e.g. move `struct Diagnostic` just before `impl Diagnostic`.
This commit only moves code around. There are no functional changes.
Overhaul `Diagnostic` and `DiagnosticBuilder`
Implements the first part of https://github.com/rust-lang/compiler-team/issues/722, which moves functionality and use away from `Diagnostic`, onto `DiagnosticBuilder`.
Likely follow-ups:
- Move things around, because this PR was written to minimize diff size, so some things end up in sub-optimal places. E.g. `DiagnosticBuilder` has impls in both `diagnostic.rs` and `diagnostic_builder.rs`.
- Rename `Diagnostic` as `DiagInner` and `DiagnosticBuilder` as `Diag`.
r? `@davidtwco`
Currently many diagnostic modifier methods are available on both
`Diagnostic` and `DiagnosticBuilder`. This commit removes most of them
from `Diagnostic`. To minimize the diff size, it keeps them within
`diagnostic.rs` but changes the surrounding `impl Diagnostic` block to
`impl DiagnosticBuilder`. (I intend to move things around later, to give
a more sensible code layout.)
`Diagnostic` keeps a few methods that it still needs, like `sub`,
`arg`, and `replace_args`.
The `forward!` macro, which defined two additional methods per call
(e.g. `note` and `with_note`), is replaced by the `with_fn!` macro,
which defines one additional method per call (e.g. `with_note`). It's
now also only used when necessary -- not all modifier methods currently
need a `with_*` form. (New ones can be easily added as necessary.)
All this also requires changing `trait AddToDiagnostic` so its methods
take `DiagnosticBuilder` instead of `Diagnostic`, which leads to many
mechanical changes. `SubdiagnosticMessageOp` gains a type parameter `G`.
There are three subdiagnostics -- `DelayedAtWithoutNewline`,
`DelayedAtWithNewline`, and `InvalidFlushedDelayedDiagnosticLevel` --
that are created within the diagnostics machinery and appended to
external diagnostics. These are handled at the `Diagnostic` level, which
means it's now hard to construct them via `derive(Diagnostic)`, so
instead we construct them by hand. This has no effect on what they look
like when printed.
There are lots of new `allow` markers for `untranslatable_diagnostics`
and `diagnostics_outside_of_impl`. This is because
`#[rustc_lint_diagnostics]` annotations were present on the `Diagnostic`
modifier methods, but missing from the `DiagnosticBuilder` modifier
methods. They're now present.
There are lots of functions that modify a diagnostic. This can be via a
`&mut Diagnostic` or a `&mut DiagnosticBuilder`, because the latter type
wraps the former and impls `DerefMut`.
This commit converts all the `&mut Diagnostic` occurrences to `&mut
DiagnosticBuilder`. This is a step towards greatly simplifying
`Diagnostic`. Some of the relevant function are made generic, because
they deal with both errors and warnings. No function bodies are changed,
because all the modifier methods are available on both `Diagnostic` and
`DiagnosticBuilder`.
errors: only eagerly translate subdiagnostics
Subdiagnostics don't need to be lazily translated, they can always be eagerly translated. Eager translation is slightly more complex as we need to have a `DiagCtxt` available to perform the translation, which involves slightly more threading of that context.
This slight increase in complexity should enable later simplifications - like passing `DiagCtxt` into `AddToDiagnostic` and moving Fluent messages into the diagnostic structs rather than having them in separate files (working on that was what led to this change).
r? ```@nnethercote```
Fix msg for verbose suggestions with confusable capitalization
When encountering a verbose/multipart suggestion that has changes that are only caused by different capitalization of ASCII letters that have little differenciation, expand the message to highlight that fact (like we already do for inline suggestions).
The logic to do this was already present, but implemented incorrectly.
Subdiagnostics don't need to be lazily translated, they can always be
eagerly translated. Eager translation is slightly more complex as we need
to have a `DiagCtxt` available to perform the translation, which involves
slightly more threading of that context.
This slight increase in complexity should enable later simplifications -
like passing `DiagCtxt` into `AddToDiagnostic` and moving Fluent messages
into the diagnostic structs rather than having them in separate files
(working on that was what led to this change).
Signed-off-by: David Wood <david@davidtw.co>
When encountering a verbose/multipart suggestion that has changes
that are only caused by different capitalization of ASCII letters that have
little differenciation, expand the message to highlight that fact (like we
already do for inline suggestions).
The logic to do this was already present, but implemented incorrectly.
Optimize `delayed_bug` handling.
Once we have emitted at least one error, delayed bugs won't be used. So we can (a) we can (a) discard any existing delayed bugs, and (b) stop recording any new delayed bugs.
This eliminates a longstanding `FIXME` comment. There should be no soundness issues because it's not possible to un-emit an error.
r? `@oli-obk`
`cargo update`
Run `cargo update`, with some pinning and fixes necessitated by that. This *should* unblock #112865
There's a couple of places where I only pinned a dependency in one location - this seems like a bit of a hack, but better than duplicating the FIXME across all `Cargo.toml` where a dependency is introduced.
cc `@Nilstrieb`
Once we have emitted at least one error, delayed bugs won't be used. So
we can (a) we can (a) discard any existing delayed bugs, and (b) stop
recording any new delayed bugs.
This eliminates a longstanding `FIXME` comment. There should be no
soundness issues because it's not possible to un-emit an error.
There are a couple of places where we call
`inner.emitter.emit_diagnostic` directly rather than going through
`inner.emit_diagnostic`, to guarantee the diagnostic is printed. This
feels dubious to me, particularly the bypassing of `TRACK_DIAGNOSTIC`.
This commit removes those.
- In `print_error_count`, it uses `ForceWarning` instead of `Warning`.
- It removes `DiagCtxtInner::failure_note`, because it only has three
uses and direct use of `emit_diagnostic` is consistent with other
similar locations.
- It removes `force_print_diagnostic`, and adds `struct_failure_note`,
and updates `print_query_stack` accordingly, which makes it more
normal. That location doesn't seem to need forced printing anyway.
It's only has a single remaining purpose: to ensure that a diagnostic is
printed when `trimmed_def_paths` is used. It's an annoying mechanism:
weak, with odd semantics, badly named, and gets in the way of other
changes.
This commit replaces it with a simpler `must_produce_diag` mechanism,
getting rid of a diagnostic `Level` along the way.
Now that error counts can't go up and down due to stashing/stealing, we
have a nice property:
(err_count > 0) iff (an ErrorGuaranteed has been produced)
So we can now record `ErrorGuaranteed`s within `DiagCtxt` and use that
in methods like `has_error`, instead of checking that the count is
greater than 0 and calling `unchecked_error_guaranteed` to create the
`ErrorGuaranteed`.
In fact, we can record a `Vec<ErrorGuaranteed>` and use its length to
count the number, instead of maintaining a separate count.
- Remove low-value comments about functionality that is obvious.
- Add missing `track_caller` attributes -- every method should have one.
- Adjust `rustc_lint_diagnostic` attributes. Every method involving a
`impl Into<DiagnosticMessage>` or `impl Into<SubdiangnosticMessage>`
argument should have one, except for those producing bugs, which
aren't user-facing.
The current order is almost perfectly random. This commit puts them into
a predictable order in their own impl block, going from the highest
level (`Block`) to the lowest (`Expect`). Within each level this is the
order:
- struct_err, err
- struct_span_err, span_err
- create_err, emit_err
The first one in each pair creates a diagnostic, the second one creates
*and* emits a diagnostic. Not every method is present for every level.
The diff is messy, but other than moving methods around, the only thing
it does is create the new `impl DiagCtxt` block with its own comment.
Suppress suggestions in derive macro
close#118809
I suppress warnings inside derive macros.
For example, the compiler emits following error by a program described in https://github.com/rust-lang/rust/issues/118809#issuecomment-1852256687 with a suggestion that indicates invalid syntax.
```
error[E0308]: `?` operator has incompatible types
--> src/main.rs:3:17
|
3 | #[derive(Debug, Deserialize)]
| ^^^^^^^^^^^ expected `u32`, found `u64`
|
= note: `?` operator cannot convert from `u64` to `u32`
= note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
help: you can convert a `u64` to a `u32` and panic if the converted value doesn't fit
|
3 | #[derive(Debug, Deserialize.try_into().unwrap())]
| ++++++++++++++++++++
For more information about this error, try `rustc --explain E0308`.
error: could not compile `serde_test` (bin "serde_test") due to 2 previous errors
```
In this PR, suggestions to cast are suppressed.
```
error[E0308]: `?` operator has incompatible types
--> src/main.rs:3:17
|
3 | #[derive(Debug, Deserialize)]
| ^^^^^^^^^^^ expected `u32`, found `u64`
|
= note: `?` operator cannot convert from `u64` to `u32`
= note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
For more information about this error, try `rustc --explain E0308`.
error: could not compile `serde_test` (bin "serde_test") due to 2 previous errors
```
These crates all needed specialization for `newtype_index!`, which will no
longer be necessary when the current nightly eventually becomes the next
bootstrap compiler.
Fix `ErrorGuaranteed` unsoundness with stash/steal.
When you stash an error, the error count is incremented. You can then use the non-zero error count to get an `ErrorGuaranteed`. You can then steal the error, which decrements the error count. You can then cancel the error.
Example code:
```
fn unsound(dcx: &DiagCtxt) -> ErrorGuaranteed {
let sp = rustc_span::DUMMY_SP;
let k = rustc_errors::StashKey::Cycle;
dcx.struct_err("bogus").stash(sp, k); // increment error count on stash
let guar = dcx.has_errors().unwrap(); // ErrorGuaranteed from error count > 0
let err = dcx.steal_diagnostic(sp, k).unwrap(); // decrement error count on steal
err.cancel(); // cancel error
guar // ErrorGuaranteed with no error emitted!
}
```
This commit fixes the problem in the simplest way: by not counting stashed errors in `DiagCtxt::{err_count,has_errors}`.
However, just doing this without any other changes leads to over 40 ui test failures. Mostly because of uninteresting extra errors (many saying "type annotations needed" when type inference fails), and in a few cases, due to delayed bugs causing ICEs when no normal errors are printed.
To fix these, this commit adds `DiagCtxt::stashed_err_count`, and uses it in three places alongside `DiagCtxt::{has_errors,err_count}`. It's dodgy to rely on it, because unlike `DiagCtxt::err_count` it can go up and down. But it's needed to preserve existing behaviour, and at least the three places that need it are now obvious.
r? oli-obk
Invert diagnostic lints.
That is, change `diagnostic_outside_of_impl` and `untranslatable_diagnostic` from `allow` to `deny`, because more than half of the compiler has been converted to use translated diagnostics.
This commit removes more `deny` attributes than it adds `allow` attributes, which proves that this change is warranted.
r? ````@davidtwco````
When you stash an error, the error count is incremented. You can then
use the non-zero error count to get an `ErrorGuaranteed`. You can then
steal the error, which decrements the error count. You can then cancel
the error.
Example code:
```
fn unsound(dcx: &DiagCtxt) -> ErrorGuaranteed {
let sp = rustc_span::DUMMY_SP;
let k = rustc_errors::StashKey::Cycle;
dcx.struct_err("bogus").stash(sp, k); // increment error count on stash
let guar = dcx.has_errors().unwrap(); // ErrorGuaranteed from error count > 0
let err = dcx.steal_diagnostic(sp, k).unwrap(); // decrement error count on steal
err.cancel(); // cancel error
guar // ErrorGuaranteed with no error emitted!
}
```
This commit fixes the problem in the simplest way: by not counting
stashed errors in `DiagCtxt::{err_count,has_errors}`.
However, just doing this without any other changes leads to over 40 ui
test failures. Mostly because of uninteresting extra errors (many saying
"type annotations needed" when type inference fails), and in a few
cases, due to delayed bugs causing ICEs when no normal errors are
printed.
To fix these, this commit adds `DiagCtxt::stashed_err_count`, and uses
it in three places alongside `DiagCtxt::{has_errors,err_count}`. It's
dodgy to rely on it, because unlike `DiagCtxt::err_count` it can go up
and down. But it's needed to preserve existing behaviour, and at least
the three places that need it are now obvious.
