Refactor vtable codegen
This refactor the codegen of vtables of miri interpreter, llvm, cranelift codegen backends.
This is preparation for the implementation of trait upcasting feature. cc #65991
Note that aside from code reorganization, there's an internal behavior change here that now InstanceDef::Virtual's index now include the three metadata slots, and now the first method is with index 3.
cc `@RalfJung` `@bjorn3`
Fix ICEs on invalid vtable size/alignment const UB errors
The invalid vtable size/alignment errors from `InterpCx::read_size_and_align_from_vtable` were "freeform const UB errors", causing ICEs when reaching validation. This PR turns them into const UB hard errors to catch them during validation and avoid that.
Fixes#86193
r? `@RalfJung`
(It seemed cleaner to have 2 variants but they can be merged into one variant with a message payload if you prefer that ?)
Hash DefId in rustc_span.
This is mostly just moving code around. Changes are simplifications of unneeded callbacks from rustc_span to rustc_middle.
r? `@petrochenkov`
Make `relate_type_and_mut` public
#85343 improved diagnostics around `Relate` impls but made `relate_type_and_mut` private, which was accessible as `relate` previously. This makes it public so that we can use it on rust-semverver.
r? ```@Aaron1011```
Fix some diagnostic issues with const_generics_defaults feature gate
This PR makes a few changes:
- print out const param defaults in "lifetime ordering" errors rather than discarding them
- update `is_simple_text` to account for const params when checking if a type has no generics, this was causing a note to be failed to add to an error message
- fixes some diagnostic wording that incorrectly said there was ordering restrictions between type/const params despite the `const_generics_defaults` feature gate is active
Fix ICE during type layout when there's a `[type error]`
Fixes#84108.
Based on estebank's [comment], except I used `delay_span_bug` because it
should work in more cases, and I think it expresses its intent more
clearly.
r? `@estebank`
[comment]: https://github.com/rust-lang/rust/issues/84108#issuecomment-818916848
Partial support for raw-dylib linkage
First cut of functionality for issue #58713: add support for `#[link(kind = "raw-dylib")]` on `extern` blocks in lib crates compiled to .rlib files. Does not yet support `#[link_name]` attributes on functions, or the `#[link_ordinal]` attribute, or `#[link(kind = "raw-dylib")]` on `extern` blocks in bin crates; I intend to publish subsequent PRs to fill those gaps. It's also not yet clear whether this works for functions in `extern "stdcall"` blocks; I also intend to investigate that shortly and make any necessary changes as a follow-on PR.
This implementation calls out to an LLVM function to construct the actual `.idata` sections as temporary `.lib` files on disk and then links those into the generated .rlib.
Allow raw pointers in SIMD types
Closes#85915 by loosening the strictness in typechecking and adding a test to guarantee it passes.
This still might be too strict, as references currently do pass monomorphization, but my understanding is that they are not guaranteed to be "scalar" in the same way.
This does not yet support #[link_name] attributes on functions, the #[link_ordinal]
attribute, #[link(kind = "raw-dylib")] on extern blocks in bin crates, or
stdcall functions on 32-bit x86.
Support for force-warns
Implements https://github.com/rust-lang/rust/issues/85512.
This PR adds a new command line option `force-warns` which will force the provided lints to warn even if they are allowed by some other mechanism such as `#![allow(warnings)]`.
Some remaining issues:
* https://github.com/rust-lang/rust/issues/85512 mentions that `force-warns` should also be capable of taking lint groups instead of individual lints. This is not implemented.
* If a lint has a higher warning level than `warn`, this will cause that lint to warn instead. We probably want to allow the lint to error if it is set to a higher lint and is not allowed somewhere else.
* One test is currently ignored because it's not working - when a deny-by-default lint is allowed, it does not currently warn under `force-warns`. I'm not sure why, but I wanted to get this in before the weekend.
r? `@nikomatsakis`
Remove unused feature gates
The first commit removes a usage of a feature gate, but I don't expect it to be controversial as the feature gate was only used to workaround a limitation of rust in the past. (closures never being `Clone`)
The second commit uses `#[allow_internal_unstable]` to avoid leaking the `trusted_step` feature gate usage from inside the index newtype macro. It didn't work for the `min_specialization` feature gate though.
The third commit removes (almost) all feature gates from the compiler that weren't used anyway.
