Expand macros in `extern {}` blocks
This permits macro and proc-macro and attribute invocations (the latter only with the `proc_macro` feature of course) in `extern {}` blocks, gated behind a new `macros_in_extern` feature.
A tracking issue is now open at #49476closes#48747
No longer parse it.
Remove AutoTrait variant from AST and HIR.
Remove backwards compatibility lint.
Remove coherence checks, they make no sense for the new syntax.
Remove from rustdoc.
The Generics now contain one Vec of an enum for the generic parameters,
rather than two separate Vec's for lifetime and type parameters.
Additionally, places that previously used Vec<LifetimeDef> now use
Vec<GenericParam> instead.
DefaultImpl is a highly confusing name for what we now call auto impls,
as in `impl Send for ..`. The name auto impl is not formally decided
but for sanity anything is better than `DefaultImpl` which refers
neither to `default impl` nor to `impl Default`.
Add lint for unused macros
Addresses parts of #34938, to add a lint for unused macros.
We now output warnings by default when we encounter a macro that we didn't use for expansion.
Issues to be resolved before this PR is ready for merge:
- [x] fix the NodeId issue described above
- [x] remove all unused macros from rustc and the libraries or set `#[allow(unused_macros)]` next to them if they should be kept for some reason. This is needed for successful boostrap and bors to accept the PR. -> #41934
- [x] ~~implement the full extent of #34938, that means the macro match arm checking as well.~~ *let's not do this for now*
this commit implements the first step of the `default impl` feature:
all items in a `default impl` are (implicitly) `default` and hence
specializable.
In order to test this feature I've copied all the tests provided for the
`default` method implementation (in run-pass/specialization and
compile-fail/specialization directories) and moved the `default` keyword
from the item to the impl.
See referenced issue for further info
Add a `TyErr` type to represent unknown types in places where
parse errors have happened, while still able to build the AST.
Initially only used to represent incorrectly written fn arguments and
avoid "expected X parameters, found Y" errors when called with the
appropriate amount of parameters. We cannot use `TyInfer` for this as
`_` is not allowed as a valid argument type.
Example output:
```rust
error: expected one of `:` or `@`, found `,`
--> file.rs:12:9
|
12 | fn bar(x, y: usize) {}
| ^
error[E0061]: this function takes 2 parameters but 3 parameters were supplied
--> file.rs:19:9
|
12 | fn bar(x, y) {}
| --------------- defined here
...
19 | bar(1, 2, 3);
| ^^^^^^^ expected 2 parameters
```
Merge ObjectSum and PolyTraitRef in AST/HIR + some other refactoring
`ObjectSum` and `PolyTraitRef` are the same thing (list of bounds), they exist separately only due to parser quirks. The second commit merges them.
The first commit replaces `Path` with `Ty` in (not yet supported) equality predicates. They are parsed as types anyway and arbitrary types can always be disguised as paths using aliases, so this doesn't add any new functionality.
The third commit uses `Vec` instead of `P<[T]>` in AST. AST is not immutable like HIR and `Vec`s are more convenient for it, unnecessary conversions are also avoided.
The last commit renames `parse_ty_sum` (which is used for parsing types in general) into `parse_ty`, and renames `parse_ty` (which is used restricted contexts where `+` is not permitted due to operator priorities or other reasons) into `parse_ty_no_plus`.
This is the first part of https://github.com/rust-lang/rust/issues/39085#issuecomment-272743755 and https://github.com/rust-lang/rust/issues/39080 focused on data changes and mechanical renaming, I'll submit a PR with parser changes a bit later.
r? @eddyb
