Refactor lint buffering to avoid requiring a giant enum
Lint buffering currently relies on a giant enum `BuiltinLintDiag` containing all the lints that might potentially get buffered. In addition to being an unwieldy enum in a central crate, this also makes `rustc_lint_defs` a build bottleneck: it depends on various types from various crates (with a steady pressure to add more), and many crates depend on it.
Having all of these variants in a separate crate also prevents detecting when a variant becomes unused, which we can do with a dedicated type defined and used in the same crate.
Refactor this to use a dyn trait, to allow using `LintDiagnostic` types directly.
Because the existing `BuiltinLintDiag` requires some additional types in order to decorate some variants, which are only available later in `rustc_lint`, use an enum `DecorateDiagCompat` to handle both the `dyn LintDiagnostic` case and the `BuiltinLintDiag` case.
---
With the infrastructure in place, use it to migrate three of the enum variants to use `LintDiagnostic` directly, as a proof of concept and to demonstrate that the net result is a reduction in code size and a removal of a boilerplate-heavy layer of indirection.
Also remove an unused `BuiltinLintDiag` variant.
resolve: Remove `ScopeSet::Late`
It's better to decouple the late/early stage from scope set, because in https://github.com/rust-lang/rust/pull/144131#discussion_r2283200511 we'll need the stage for `ScopeSet::Module` as well.
See individual commits for the refactoring details.
r? ``@b-naber``
Lint buffering currently relies on a giant enum `BuiltinLintDiag`
containing all the lints that might potentially get buffered. In
addition to being an unwieldy enum in a central crate, this also makes
`rustc_lint_defs` a build bottleneck: it depends on various types from
various crates (with a steady pressure to add more), and many crates
depend on it.
Having all of these variants in a separate crate also prevents detecting
when a variant becomes unused, which we can do with a dedicated type
defined and used in the same crate.
Refactor this to use a dyn trait, to allow using `LintDiagnostic` types
directly.
This requires boxing, but all of this is already on the slow path
(emitting an error).
Because the existing `BuiltinLintDiag` requires some additional types in
order to decorate some variants, which are only available later in
`rustc_lint`, use an enum `DecorateDiagCompat` to handle both the `dyn
LintDiagnostic` case and the `BuiltinLintDiag` case.
Prevent impossible combinations in `ast::ModKind`.
`ModKind::Loaded` has an `inline` field and a `had_parse_error` field. If the `inline` field is `Inline::Yes` then `had_parse_error` must be `Ok(())`.
This commit moves the `had_parse_error` field into the `Inline::No` variant. This makes it impossible to create the nonsensical combination of `inline == Inline::Yes` and `had_parse_error = Err(_)`.
r? ```@Urgau```
`rustc_lint_defs` uses `rustc_hir` solely for the `Namespace` type,
which it only needs the static description from. Use the static
description directly, to eliminate the dependency on `rustc_hir`.
This reduces a long dependency chain:
- Many things depend on `rustc_errors`
- `rustc_errors` depends on `rustc_lint_defs`
- `rustc_lint_defs` depended on `rustc_hir` prior to this commit
- `rustc_hir` depends on `rustc_target`
`ModKind::Loaded` has an `inline` field and a `had_parse_error` field.
If the `inline` field is `Inline::Yes` then `had_parse_error` must be
`Ok(())`.
This commit moves the `had_parse_error` field into the `Inline::No`
variant. This makes it impossible to create the nonsensical combination
of `inline == Inline::Yes` and `had_parse_error = Err(_)`.
Detect missing `derive` on unresolved attribute even when not imported
When encountering unresolved attributes, ensure the proc-macros for every crate in scope are added to the `macro_map` so that typos and missing `derive`s are properly detected.
```
error: cannot find attribute `sede` in this scope
--> $DIR/missing-derive-3.rs:20:7
|
LL | #[sede(untagged)]
| ^^^^
|
help: the derive macros `Deserialize` and `Serialize` accept the similarly named `serde` attribute
|
LL | #[serde(untagged)]
| +
error: cannot find attribute `serde` in this scope
--> $DIR/missing-derive-3.rs:14:7
|
LL | #[serde(untagged)]
| ^^^^^
|
note: `serde` is imported here, but it is a crate, not an attribute
--> $DIR/missing-derive-3.rs:4:1
|
LL | extern crate serde;
| ^^^^^^^^^^^^^^^^^^^
help: `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`, you might be missing a `derive` attribute
|
LL + #[derive(Deserialize, Serialize)]
LL | enum B {
|
```
Follow up to rust-lang/rust#134841. Fixrust-lang/rust#47608.
Implement declarative (`macro_rules!`) derive macros (RFC 3698)
This is a draft for review, and should not be merged yet.
This is layered atop https://github.com/rust-lang/rust/pull/145153 , and has
only two additional commits atop that. The first handles parsing and provides a
test for various parse errors. The second implements expansion and handles
application.
This implements RFC 3698, "Declarative (`macro_rules!`) derive macros".
Tracking issue: https://github.com/rust-lang/rust/issues/143549
This has one remaining issue, which I could use some help debugging: in
`tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for
`derive(fn_only)` (for a `fn_only` with no `derive` rules) and
`derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate
diagnostic.
From what I can tell via adding some debugging code,
`unresolved_macro_suggestions` is getting called twice from
`finalize_macro_resolutions` for each of them, because
`self.single_segment_macro_resolutions` has two entries for the macro, with two
different `parent_scope` values. I'm not clear on why that happened; it doesn't
happen with the equivalent code using attrs.
I'd welcome any suggestions for fixing this.
```
error: cannot find attribute `sede` in this scope
--> $DIR/missing-derive-3.rs:20:7
|
LL | #[sede(untagged)]
| ^^^^
|
help: the derive macros `Deserialize` and `Serialize` accept the similarly named `serde` attribute
|
LL | #[serde(untagged)]
| +
error: cannot find attribute `serde` in this scope
--> $DIR/missing-derive-3.rs:14:7
|
LL | #[serde(untagged)]
| ^^^^^
|
note: `serde` is imported here, but it is a crate, not an attribute
--> $DIR/missing-derive-3.rs:4:1
|
LL | extern crate serde;
| ^^^^^^^^^^^^^^^^^^^
help: `serde` is an attribute that can be used by the derive macros `Deserialize` and `Serialize`, you might be missing a `derive` attribute
|
LL + #[derive(Deserialize, Serialize)]
LL | enum B {
|
```
Resolve the prelude import in `build_reduced_graph`
This pr tries to resolve the prelude import at the `build_reduced_graph` stage.
Part of batched import resolution in rust-lang/rust#145108 (cherry picked commit) and maybe needed for rust-lang/rust#139493.
r? petrochenkov
Add infrastructure to apply a derive macro to arguments, consuming and
returning a `TokenTree` only.
Handle `SyntaxExtensionKind::MacroRules` when expanding a derive, if the
macro's kinds support derive.
Add tests covering various cases of `macro_rules` derives.
Note that due to a pre-existing FIXME in `expand.rs`, derives are
re-queued and some errors get emitted twice. Duplicate diagnostic
suppression makes them not visible, but the FIXME should still get
fixed.
Remove one FIXME, addressing it does not reduce the hacky-ness much, and the logic is going to be removed anyway together with the `legacy_derive_helpers` deprecation lint.
resolve: Split extern prelude into two scopes
One scope for `extern crate` items and another for `--extern` options, with the former shadowing the latter.
If in a single scope some things can overwrite other things, especially with ad hoc restrictions like `MacroExpandedExternCrateCannotShadowExternArguments`, then it's not really a single scope.
So this PR splits `Scope::ExternPrelude` into two cleaner scopes.
This is similar to how https://github.com/rust-lang/rust/pull/144131 splits module scope into two scopes for globs and non-globs, but simpler.
Handle macros with multiple kinds, and improve errors
(I recommend reviewing this commit-by-commit.)
Switch to a bitflags `MacroKinds` to support macros with more than one kind
Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`.
Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds.
This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`.
Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes.
This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules.
Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors.
This also handles cases of forward-referenced attributes and cyclic attributes.
----
In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds.
rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that.
----
r? ````````@petrochenkov````````
This eliminates the case in `failed_to_match_macro` to check for a
function-like invocation of a macro with no function-like rules.
Instead, macro kind mismatches now result in an unresolved macro, and we
detect this case in `unresolved_macro_suggestions`, which now carefully
distinguishes between a kind mismatch and other errors.
This also handles cases of forward-referenced attributes and cyclic
attributes.
Expand test coverage to include all of these cases.
Review everything that uses `MacroKind`, and switch anything that could
refer to more than one kind to use `MacroKinds`.
Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros,
using the concrete `MacroRulesMacroExpander` type, and have it track
which kinds it can handle. Eliminate the separate optional `attr_ext`,
now that a `SyntaxExtension` can handle multiple macro kinds.
This also avoids the need to downcast when calling methods on
`MacroRulesMacroExpander`, such as `get_unused_rule`.
Integrate macro kind checking into name resolution's
`sub_namespace_match`, so that we only find a macro if it's the right
type, and eliminate the special-case hack for attributes.
When trying to construct a struct that has a public field of a private type, suggest using `..` if that field has a default value.
```
error[E0603]: struct `Priv1` is private
--> $DIR/non-exhaustive-ctor.rs:25:39
|
LL | let _ = S { field: (), field1: m::Priv1 {} };
| ------ ^^^^^ private struct
| |
| while setting this field
|
note: the struct `Priv1` is defined here
--> $DIR/non-exhaustive-ctor.rs:14:4
|
LL | struct Priv1 {}
| ^^^^^^^^^^^^
help: the field `field1` you're trying to set has a default value, you can use `..` to use it
|
LL | let _ = S { field: (), .. };
| ~~
```
Implement declarative (`macro_rules!`) attribute macros (RFC 3697)
This implements [RFC 3697](https://github.com/rust-lang/rust/issues/143547), "Declarative (`macro_rules!`) attribute macros".
I would suggest reading this commit-by-commit. This first introduces the
feature gate, then adds parsing for attribute rules (doing nothing with them),
then adds the ability to look up and apply `macro_rules!` attributes by path,
then adds support for local attributes, then adds a test, and finally makes
various improvements to errors.
