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.
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>
- In `emit_producing_error_guaranteed`, only allow `Level::Error`.
- In `emit_diagnostic`, only produce `ErrorGuaranteed` for `Level` and
`DelayedBug`. (Not `Bug` or `Fatal`. They don't need it, because the
relevant `emit` methods abort.)
- Add/update various comments.
Error codes are integers, but `String` is used everywhere to represent
them. Gross!
This commit introduces `ErrCode`, an integral newtype for error codes,
replacing `String`. It also introduces a constant for every error code,
e.g. `E0123`, and removes the `error_code!` macro. The constants are
imported wherever used with `use rustc_errors::codes::*`.
With the old code, we have three different ways to specify an error code
at a use point:
```
error_code!(E0123) // macro call
struct_span_code_err!(dcx, span, E0123, "msg"); // bare ident arg to macro call
\#[diag(name, code = "E0123")] // string
struct Diag;
```
With the new code, they all use the `E0123` constant.
```
E0123 // constant
struct_span_code_err!(dcx, span, E0123, "msg"); // constant
\#[diag(name, code = E0123)] // constant
struct Diag;
```
The commit also changes the structure of the error code definitions:
- `rustc_error_codes` now just defines a higher-order macro listing the
used error codes and nothing else.
- Because that's now the only thing in the `rustc_error_codes` crate, I
moved it into the `lib.rs` file and removed the `error_codes.rs` file.
- `rustc_errors` uses that macro to define everything, e.g. the error
code constants and the `DIAGNOSTIC_TABLES`. This is in its new
`codes.rs` file.
`Diagnostic::code` has the type `DiagnosticId`, which has `Error` and
`Lint` variants. Plus `Diagnostic::is_lint` is a bool, which should be
redundant w.r.t. `Diagnostic::code`.
Seems simple. Except it's possible for a lint to have an error code, in
which case its `code` field is recorded as `Error`, and `is_lint` is
required to indicate that it's a lint. This is what happens with
`derive(LintDiagnostic)` lints. Which means those lints don't have a
lint name or a `has_future_breakage` field because those are stored in
the `DiagnosticId::Lint`.
It's all a bit messy and confused and seems unintentional.
This commit:
- removes `DiagnosticId`;
- changes `Diagnostic::code` to `Option<String>`, which means both
errors and lints can straightforwardly have an error code;
- changes `Diagnostic::is_lint` to `Option<IsLint>`, where `IsLint` is a
new type containing a lint name and a `has_future_breakage` bool, so
all lints can have those, error code or not.
But we can't easily switch from `Vec<Diagnostic>` to
`Vec<DiagnosticBuilder<G>>` because there's a mix of errors and warnings
which result in different `G` types. So we must make
`DiagnosticBuilder::into_diagnostic` public, but that's ok, and it will
get more use in subsequent commits.
It seems very wrong to have a `-Ztreat-err-as-bug` check here before the
error is even emitted.
Once that's done:
- `into_diagnostic` is infallible, so its return type doesn't need the
`Option`;
- the `&'a DiagCtxt` also isn't needed, because only one callsite uses
it, and it already have access to it via `self.dcx`;
- the comments about dcx disabling buffering are no longer true, this is
unconditional now;
- and the `debug!` seems unnecessary... the comment greatly overstates
its importance because few diagnostics come through `into_diagnostic`,
and `-Ztrack-diagnostics` exists anyway.
This lets us avoid the use of `DiagnosticBuilder::into_diagnostic` in
miri, when then means that `DiagnosticBuilder::into_diagnostic` can
become private, being now only used by `stash` and `buffer`.
In #119606 I added them and used a `_mv` suffix, but that wasn't great.
A `with_` prefix has three different existing uses.
- Constructors, e.g. `Vec::with_capacity`.
- Wrappers that provide an environment to execute some code, e.g.
`with_session_globals`.
- Consuming chaining methods, e.g. `Span::with_{lo,hi,ctxt}`.
The third case is exactly what we want, so this commit changes
`DiagnosticBuilder::foo_mv` to `DiagnosticBuilder::with_foo`.
Thanks to @compiler-errors for the suggestion.
Because it takes an error code after the span. This avoids the confusing
overlap with the `DiagCtxt::struct_span_err` method, which doesn't take
an error code.
It was added in #54232. It seems like it was aimed at NLL development,
which is well in the past. Also, it looks like `-Ztreat-err-as-bug` can
be used to achieve the same effect. So it doesn't seem necessary.
Currently it's used for two dynamic checks:
- When a diagnostic is emitted, has it been emitted before?
- When a diagnostic is dropped, has it been emitted/cancelled?
The first check is no longer need, because `emit` is consuming, so it's
impossible to emit a `DiagnosticBuilder` twice. The second check is
still needed.
This commit replaces `DiagnosticBuilderState` with a simpler
`Option<Box<Diagnostic>>`, which is enough for the second check:
functions like `emit` and `cancel` can take the `Diagnostic` and then
`drop` can check that the `Diagnostic` was taken.
The `DiagCtxt` reference from `DiagnosticBuilderState` is now stored as
its own field, removing the need for the `dcx` method.
As well as making the code shorter and simpler, the commit removes:
- One (deprecated) `ErrorGuaranteed::unchecked_claim_error_was_emitted`
call.
- Two `FIXME(eddyb)` comments that are no longer relevant.
- The use of a dummy `Diagnostic` in `into_diagnostic`.
Nice!
The existing uses are replaced in one of three ways.
- In a function that also has calls to `emit`, just rearrange the code
so that exactly one of `delay_as_bug` or `emit` is called on every
path.
- In a function returning a `DiagnosticBuilder`, use
`downgrade_to_delayed_bug`. That's good enough because it will get
emitted later anyway.
- In `unclosed_delim_err`, one set of errors is being replaced with
another set, so just cancel the original errors.
This works for most of its call sites. This is nice, because `emit` very
much makes sense as a consuming operation -- indeed,
`DiagnosticBuilderState` exists to ensure no diagnostic is emitted
twice, but it uses runtime checks.
For the small number of call sites where a consuming emit doesn't work,
the commit adds `DiagnosticBuilder::emit_without_consuming`. (This will
be removed in subsequent commits.)
Likewise, `emit_unless` becomes consuming. And `delay_as_bug` becomes
consuming, while `delay_as_bug_without_consuming` is added (which will
also be removed in subsequent commits.)
All this requires significant changes to `DiagnosticBuilder`'s chaining
methods. Currently `DiagnosticBuilder` method chaining uses a
non-consuming `&mut self -> &mut Self` style, which allows chaining to
be used when the chain ends in `emit()`, like so:
```
struct_err(msg).span(span).emit();
```
But it doesn't work when producing a `DiagnosticBuilder` value,
requiring this:
```
let mut err = self.struct_err(msg);
err.span(span);
err
```
This style of chaining won't work with consuming `emit` though. For
that, we need to use to a `self -> Self` style. That also would allow
`DiagnosticBuilder` production to be chained, e.g.:
```
self.struct_err(msg).span(span)
```
However, removing the `&mut self -> &mut Self` style would require that
individual modifications of a `DiagnosticBuilder` go from this:
```
err.span(span);
```
to this:
```
err = err.span(span);
```
There are *many* such places. I have a high tolerance for tedious
refactorings, but even I gave up after a long time trying to convert
them all.
Instead, this commit has it both ways: the existing `&mut self -> Self`
chaining methods are kept, and new `self -> Self` chaining methods are
added, all of which have a `_mv` suffix (short for "move"). Changes to
the existing `forward!` macro lets this happen with very little
additional boilerplate code. I chose to add the suffix to the new
chaining methods rather than the existing ones, because the number of
changes required is much smaller that way.
This doubled chainging is a bit clumsy, but I think it is worthwhile
because it allows a *lot* of good things to subsequently happen. In this
commit, there are many `mut` qualifiers removed in places where
diagnostics are emitted without being modified. In subsequent commits:
- chaining can be used more, making the code more concise;
- more use of chaining also permits the removal of redundant diagnostic
APIs like `struct_err_with_code`, which can be replaced easily with
`struct_err` + `code_mv`;
- `emit_without_diagnostic` can be removed, which simplifies a lot of
machinery, removing the need for `DiagnosticBuilderState`.
It's not used, and doesn't quite fit the general pattern.
Also, `Diagnostic::downgrade_to_delayed_bug` doesn't need to return
`&mut Self` for the same reason.
`Diagnostic` has 40 methods that return `&mut Self` and could be
considered setters. Four of them have a `set_` prefix. This doesn't seem
necessary for a type that implements the builder pattern. This commit
removes the `set_` prefixes on those four methods.
`IntoDiagnostic` defaults to `ErrorGuaranteed`, because errors are the
most common diagnostic level. It makes sense to do likewise for the
closely-related (and much more widely used) `DiagnosticBuilder` type,
letting us write `DiagnosticBuilder<'a, ErrorGuaranteed>` as just
`DiagnosticBuilder<'a>`. This cuts over 200 lines of code due to many
multi-line things becoming single line things.
This lets different error levels share the same return type from
`emit_*`.
- A lot of inconsistencies in the `DiagCtxt` API are removed.
- `Noted` is removed.
- `FatalAbort` is introduced for fatal errors (abort via `raise`),
replacing the `EmissionGuarantee` impl for `!`.
- `Bug` is renamed `BugAbort` (to avoid clashing with `Level::Bug` and
to mirror `FatalAbort`), and modified to work in the new way with bug
errors (abort via panic).
- Various diagnostic creators and emitters updated to the new, better
signatures. Note that `DiagCtxt::bug` no longer needs to call
`panic_any`, because `emit` handles that.
Also shorten the obnoxiously long
`diagnostic_builder_emit_producing_guarantee` name.
And make all hand-written `IntoDiagnostic` impls generic, by using
`DiagnosticBuilder::new(dcx, level, ...)` instead of e.g.
`dcx.struct_err(...)`.
This means the `create_*` functions are the source of the error level.
This change will let us remove `struct_diagnostic`.
Note: `#[rustc_lint_diagnostics]` is added to `DiagnosticBuilder::new`,
it's necessary to pass diagnostics tests now that it's used in
`into_diagnostic` functions.
Currently, `emit_diagnostic` takes `&mut self`.
This commit changes it so `emit_diagnostic` takes `self` and the new
`emit_diagnostic_without_consuming` function takes `&mut self`.
I find the distinction useful. The former case is much more common, and
avoids a bunch of `mut` and `&mut` occurrences. We can also restrict the
latter with `pub(crate)` which is nice.
