Opaque builtin derive macros
* Buiilt-in derives are now opaque macros
* This required limiting the visibility of some previously unexposed functions in `core`.
* This also required the change to `Ident` serialization.
* All gensyms are replaced with hygienic identifiers
* Use hygiene to avoid most other name-resolution issues with buiilt-in derives.
* As far as I know the only remaining case that breaks is an ADT that has the same name as one of its parameters. Fixing this completely seemed to be more effort than it's worth.
* Remove gensym in `Ident::decode`, which lead to linker errors due to `inline` being gensymmed.
* `Ident`now panics if incremental compilation tries to serialize it (it currently doesn't).
* `Ident` no longer uses `gensym` to emulate cross-crate hygiene. It only applied to reexports.
* `SyntaxContext` is no longer serializable.
* The long-term fix for this is to properly implement cross-crate hygiene, but this seemed to be acceptable for now.
* Move type/const parameter shadowing checks to `resolve`
* This was previously split between resolve and type checking. The type checking pass compared `InternedString`s, not Identifiers.
* Removed the `SyntaxContext` from `{ast, hir}::{InlineAsm, GlobalAsm}`
cc #60869
r? @petrochenkov
rustc_codegen_utils: account for 1-indexed anonymous lifetimes in v0 mangling.
I don't really understand why `anonymize_late_bound_regions` starts with `BrAnon(1)` instead of `BrAnon(0)`, but it does (maybe @nikomatsakis knows?): c43d03a19f/src/librustc/ty/fold.rs (L696-L712)
Thankfully, the mangling format and demangler implementations are fine, and I just needed to offset the anonymized lifetime indices by `1` to get the correct mangling.
cc @alexcrichton @michaelwoerister
Most `Ident`s are serialized as `InternedString`s the exceptions are:
* Reexports
* Attributes
* Idents in macro definitions
Using gensyms helped reexports emulate hygiene. However, the actual item
wouldn't have a gensymmed name so would be usable cross-crate. So
removing this case until we have proper cross-crate hygiene seems
sensible.
Codegen attributes (`inline`, `export_name`) are resolved by their
`Symbol`. This meant that opaque macro-expanded codegen attributes could
cause linker errors. This prevented making built-in derives hygienic.
Make sure that all file loading happens via SourceMap
That way, callers don't need to repeat "let's add this to sm manually
for tracking dependencies" trick.
It should make it easier to switch to using `FileLoader` for binary
files in the future as well
cc #62948
r? @petrochenkov
Suggest Rust 2018 on `<expr>.await` with no such field
When type checking a field projection (`fn check_field`) to `<expr>.await` where `<expr>: τ` and `τ` is not a primitive type, suggest switching to Rust 2018. E.g.
```
error[E0609]: no field `await` on type `std::pin::Pin<&mut dyn std::future::Future<Output = ()>>`
--> $DIR/suggest-switching-edition-on-await.rs:31:7
|
LL | x.await;
| ^^^^^ unknown field
|
= note: to `.await` a `Future`, switch to Rust 2018
= help: set `edition = "2018"` in `Cargo.toml`
= note: for more on editions, read https://doc.rust-lang.org/edition-guide
```
Fixes https://github.com/rust-lang/rust/issues/63533
This PR also performs some preparatory cleanups in `fn check_field`; the last 2 commits are where the suggestion is introduced and tested respectively.
r? @varkor
Continue refactoring resolve and hygiene
The general goal is addressing FIXMEs from the previous PRs.
Merging similar data structures (+ prerequisites for such merging), accounting for the fact that all `ExpnId`s have associated data in `HygieneData` now (less `Option`s).
Also, some renaming.
This should be the last renaming session in this area, I think.
r? @matthewjasper
Traces already contain module info without that.
It's easy to forget to call `finalize_*` on a module.
In particular, macros enum and trait modules weren't finalized.
By happy accident macros weren't placed into those modules until now.
Test HRTB issue accepted by compiler
Hi! First Rust PR, so if anything needs changing just let me know and I'll take care of it right away.
Closes#50301 which was marked E-needstest
Reduce the genericity of closures in the iterator traits
By default, closures inherit the generic parameters of their scope,
including `Self`. However, in most cases, the closures used to implement
iterators don't need to be generic on the iterator type, only its `Item`
type. We can reduce this genericity by redirecting such closures through
local functions.
This does make the closures more cumbersome to write, but it will
hopefully reduce duplication in their monomorphizations, as well as
their related type lengths.
Rollup of 11 pull requests
Successful merges:
- #62984 (Add lint for excess trailing semicolons)
- #63075 (Miri: Check that a ptr is aligned and inbounds already when evaluating `*`)
- #63490 (libsyntax: cleanup and refactor `pat.rs`)
- #63507 (When needing type annotations in local bindings, account for impl Trait and closures)
- #63509 (Point at the right enclosing scope when using `await` in non-async fn)
- #63528 (syntax: Remove `DummyResult::expr_only`)
- #63537 (expand: Unimplement `MutVisitor` on `MacroExpander`)
- #63542 (Add NodeId for Arm, Field and FieldPat)
- #63543 (Merge Variant and Variant_)
- #63560 (move test that shouldn't be in test/run-pass/)
- #63570 (Adjust tracking issues for `MaybeUninit<T>` gates)
Failed merges:
r? @ghost
move test that shouldn't be in test/run-pass/
We no longer test `src/test/run-pass/`; the proper way now is `// run-pass` in `src/test/ui/`
r? @petrochenkov
handle elision in async fn correctly
We now always make fresh lifetimne parameters for all elided
lifetimes, whether they are in the inputs or outputs. But then
we generate `'_` in the case of elided lifetimes from the outputs.
Example:
```rust
async fn foo<'a>(x: &'a u32) -> &u32 { .. }
```
becomes
```rust
type Foo<'a, 'b> = impl Future<Output = &'b u32>;
fn foo<'a>(x: &'a u32) -> Foo<'a, '_>
```
Fixes#63388
