Don't expose redundant information in `rustc_public`'s `LayoutShape`
Enum variant layouts don't need to store a full `LayoutShape`; just storing the fields offsets is enough and all other information can be inferred from the parent layout:
- size, align and ABI don't make much sense for individual variants and should generally be taken from the parent layout instead;
- variants always have `fields: FieldsShape::Arbitrary { .. }` and `variant: VariantShape::Single { .. }`.
In principle, the same refactor could be done on `rustc_abi::Layout` (see [this comment](https://github.com/rust-lang/rust/issues/113988#issuecomment-1646982272)) but I prefer starting with this smaller change first.
abi: add a rust-preserve-none calling convention
This is the conceptual opposite of the rust-cold calling convention and is particularly useful in combination with the new `explicit_tail_calls` feature.
For relatively tight loops implemented with tail calling (`become`) each of the function with the regular calling convention is still responsible for restoring the initial value of the preserved registers. So it is not unusual to end up with a situation where each step in the tail call loop is spilling and reloading registers, along the lines of:
foo:
push r12
; do things
pop r12
jmp next_step
This adds up quickly, especially when most of the clobberable registers are already used to pass arguments or other uses.
I was thinking of making the name of this ABI a little less LLVM-derived and more like a conceptual inverse of `rust-cold`, but could not come with a great name (`rust-cold` is itself not a great name: cold in what context? from which perspective? is it supposed to mean that the function is rarely called?)
This is the conceptual opposite of the rust-cold calling convention and
is particularly useful in combination with the new `explicit_tail_calls`
feature.
For relatively tight loops implemented with tail calling (`become`) each
of the function with the regular calling convention is still responsible
for restoring the initial value of the preserved registers. So it is not
unusual to end up with a situation where each step in the tail call loop
is spilling and reloading registers, along the lines of:
foo:
push r12
; do things
pop r12
jmp next_step
This adds up quickly, especially when most of the clobberable registers
are already used to pass arguments or other uses.
I was thinking of making the name of this ABI a little less LLVM-derived
and more like a conceptual inverse of `rust-cold`, but could not come
with a great name (`rust-cold` is itself not a great name: cold in what
context? from which perspective? is it supposed to mean that the
function is rarely called?)
Removes the attribute from `MetaSized` and `PointeeSized`, with a special case in the trait solvers for `MetaSized`.
`dyn MetaSized` is a perfectly cromulent type, and seems to only have had #[rustc_do_not_implement_via_object] so the builtin object
candidate does not overlap with the builtin MetaSized impl that all `dyn` types get.
Resolves this with a special case by checking `is_sizedness_trait` where the trait solvers previously checked `implement_via_object`.
`dyn PointeeSized` alone is rejected for other reasons (since `dyn PointeeSized` is considered to have no principal trait because `PointeeSized`
is removed at an earlier stage of the compiler), but `(dyn PointeeSized + Send)` is valid and equivalent to `dyn Send`.
Add suggestions from code review
Update compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs and tests
Co-authored-by: lcnr <rust@lcnr.de>
Enum variant layouts don't need to store a full `LayoutShape`; just storing
the fields offsets is enough and all other information can be inferred from
the parent layout:
- size, align and ABI don't make much sense for individual variants and
should generally be taken from the parent layout instead;
- variants always have `fields: FieldsShape::Arbitrary { .. }` and
`variant: VariantShape::Single { .. }`.
Replace Rvalue::NullaryOp by a variant in mir::Operand.
Based on https://github.com/rust-lang/rust/pull/148151
This PR fully removes the MIR `Rvalue::NullaryOp`. After rust-lang/rust#148151, it was only useful for runtime checks like `ub_checks`, `contract_checks` and `overflow_checks`.
These are "runtime" checks, boolean constants that may only be `true` in codegen. It depends on a rustc flag passed to codegen, so we need to represent those flags cross-crate.
This PR replaces those runtime checks by special variants in MIR `ConstValue`. This allows code that expects constants to manipulate those as such, even if we may not always be able to evaluate them to actual scalars.
Introduces `BackendRepr::ScalableVector` corresponding to scalable
vector types annotated with `repr(scalable)` which lowers to a scalable
vector type in LLVM.
Co-authored-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Fix `name()` functions for local defs in rustc_public
This change fixes the behavior of the `name()` function for `CrateDef` and `Instance` which should return absolute path of items. For local items, the crate name was missing.
This resolves: https://github.com/rust-lang/project-stable-mir/issues/109
Add `DefId::parent()` accessor for `rustc_public`
Adds a `parent()` method to `DefId` (the `rustc_pub` version) which exposes the parent path, ie. `foo::bar::baz` -> `foo::bar`.
This is useful for organizing/grouping definitions into a tree, and is probably simpler and less brittle than attempting to parse the fully-qualified name into path components (e.g. especially when handling path components with qualified generic parameters).
Fix some issues around `rustc_public`
cc rust-lang/rust#148266 .
follow-up of rust-lang/rust#148341 .
This fixes the issues that can be reproduced by `x test compiler/rustc_public`:
```
error: function `run` is never used
--> compiler/rustc_public/src/compiler_interface.rs:838:15
|
838 | pub(crate) fn run<'tcx, F, T>(interface: &CompilerInterface<'tcx>, f: F) -> Result<T, Error>
| ^^^
|
= note: `-D dead-code` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(dead_code)]`
error: unreachable `pub` item
--> compiler/rustc_public/src/unstable/mod.rs:25:1
|
25 | pub trait InternalCx<'tcx>: Copy + Clone {
| ---^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| help: consider restricting its visibility: `pub(crate)`
|
= help: or consider exporting it for use by other crates
= note: `-D unreachable-pub` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(unreachable_pub)]`
error: unreachable `pub` item
--> compiler/rustc_public/src/unstable/mod.rs:62:1
|
62 | pub trait Stable<'tcx>: PointeeSized {
| ---^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| help: consider restricting its visibility: `pub(crate)`
|
= help: or consider exporting it for use by other crates
error: unreachable `pub` item
--> compiler/rustc_public/src/unstable/mod.rs:81:1
|
81 | pub trait RustcInternal {
| ---^^^^^^^^^^^^^^^^^^^^
| |
| help: consider restricting its visibility: `pub(crate)`
|
= help: or consider exporting it for use by other crates
error: could not compile `rustc_public` (lib) due to 4 previous errors
```
Add `overflow_checks` intrinsic
This adds an intrinsic which allows code in a pre-built library to inherit the overflow checks option from a crate depending on it. This enables code in the standard library to explicitly change behavior based on whether `overflow_checks` are enabled, regardless of the setting used when standard library was compiled.
This is very similar to the `ub_checks` intrinsic, and refactors the two to use a common mechanism.
The primary use case for this is to allow the new `RangeFrom` iterator to yield the maximum element before overflowing, as requested [here](https://github.com/rust-lang/rust/issues/125687#issuecomment-2151118208). This PR includes a working `IterRangeFrom` implementation based on this new intrinsic that exhibits the desired behavior.
[Prior discussion on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Ability.20to.20select.20code.20based.20on.20.60overflow_checks.60.3F)
We no longer need two thread-local variables to store the context.
We used to have two because the conversion logic used to live in a
separate crate from the rest of the business logic.
I'm also removing the Container struct and replacing the
CompilerInterface trait with a struct. This removes the unnecessary
indirection and code duplication. Using a trait would also block us
from adding any generic method to the compiler interface.
Clean up `ty::Dynamic`
1. As a follow-up to PR rust-lang/rust#143036, remove `DynKind` entirely.
2. Inside HIR ty lowering, consolidate modules `dyn_compatibility` and `lint` into `dyn_trait`
* `dyn_compatibility` wasn't about dyn compatibility itself, it's about lowering trait object types
* `lint` contained dyn-Trait-specific diagnostics+lints only
This was done in #145740 and #145947. It is causing problems for people
using r-a on anything that uses the rustc-dev rustup package, e.g. Miri,
clippy.
This repository has lots of submodules and subtrees and various
different projects are carved out of pieces of it. It seems like
`[workspace.dependencies]` will just be more trouble than it's worth.
