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
Hash the remapped sysroot instead of the original.
One of the reasons that rustc builds are not reproducible is because the --sysroot path is dependent on the current directory. We can fix this by hashing the remapped sysroot instead of the original when applicable.
Note that with this patch, the hash will stay the same if both the sysroot and the remapped path change. However, given that if the contents of the sysroot change the hash will also stay the same, this might be acceptable. I would appreciate feedback on the best way to do this.
This helps #34902, although it does not fix it by itself.
A couple of comment fixes.
This change fixes a couple of comments in the compiler code.
The first change was discussed with @eddyb. This one confused me because I thought only *public* defs were in the table (not so).
The second was a typo I noticed yesterday.
OK to go in?
cleanup: Remove `Spanned` where possible
It generally only makes sense on enums, otherwise it's more convenient to "flatten" it by adding a span field to the struct it wraps.
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
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
When encountering a boxed value as expected and a stack allocated value
that could be boxed to fulfill the expectation, like in the following
snippet, suggest `Box::new` wrapping.
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, '_>
```
Copy ty::Instance instead of passing by reference
ty::Instance is small and Copy, we should not be adding additional
indirection.
Fixes#63409.
r? @eddyb
