Combine `ty::Projection` and `ty::Opaque` into `ty::Alias`
Implements https://github.com/rust-lang/types-team/issues/79.
This PR consolidates `ty::Projection` and `ty::Opaque` into a single `ty::Alias`, with an `AliasKind` and `AliasTy` type (renamed from `ty::ProjectionTy`, which is the inner data of `ty::Projection`) defined as so:
```
enum AliasKind {
Projection,
Opaque,
}
struct AliasTy<'tcx> {
def_id: DefId,
substs: SubstsRef<'tcx>,
}
```
Since we don't have access to `TyCtxt` in type flags computation, and because repeatedly calling `DefKind` on the def-id is expensive, these two types are distinguished with `ty::AliasKind`, conveniently glob-imported into `ty::{Projection, Opaque}`. For example:
```diff
match ty.kind() {
- ty::Opaque(..) =>
+ ty::Alias(ty::Opaque, ..) => {}
_ => {}
}
```
This PR also consolidates match arms that treated `ty::Opaque` and `ty::Projection` identically.
r? `@ghost`
Use struct types during codegen in less places
This makes it easier to use cg_ssa from a backend like Cranelift that doesn't have any struct types at all. After this PR struct types are still used for function arguments and return values. Removing those usages is harder but should still be doable.
compiler: remove unnecessary imports and qualified paths
Some of these imports were necessary before Edition 2021, others were already in the prelude.
I hope it's fine that this PR is so spread-out across files :/
Fix invalid codegen during debuginfo lowering
In order for LLVM to correctly generate debuginfo for msvc, we sometimes need to spill arguments to the stack and perform some direct & indirect offsets into the value. Previously, this code always performed those actions, even when not required as LLVM would clean it up during optimization.
However, when MIR inlining is enabled, this can cause problems as the operations occur prior to the spilled value being initialized. To solve this, we first calculate the necessary offsets using just the type which is side-effect free and does not alter the LLVM IR. Then, if we are in a situation which requires us to generate the LLVM IR (and this situation only occurs for arguments, not local variables) then we perform the same calculation again, this time generating the appropriate LLVM IR as we go.
r? `@tmiasko` but feel free to reassign if you want 🙂Fixes#105386
Add LLVM KCFI support to the Rust compiler
This PR adds LLVM Kernel Control Flow Integrity (KCFI) support to the Rust compiler. It initially provides forward-edge control flow protection for operating systems kernels for Rust-compiled code only by aggregating function pointers in groups identified by their return and parameter types. (See llvm/llvm-project@cff5bef.)
Forward-edge control flow protection for C or C++ and Rust -compiled code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code share the same virtual address space) will be provided in later work as part of this project by identifying C char and integer type uses at the time types are encoded (see Type metadata in the design document in the tracking issue #89653).
LLVM KCFI can be enabled with -Zsanitizer=kcfi.
Thank you again, `@bjorn3,` `@eddyb,` `@nagisa,` and `@ojeda,` for all the help!
In order for LLVM to correctly generate debuginfo for msvc, we sometimes
need to spill arguments to the stack and perform some direct & indirect
offsets into the value. Previously, this code always performed those
actions, even when not required as LLVM would clean it up during
optimization.
However, when MIR inlining is enabled, this can cause problems as the
operations occur prior to the spilled value being initialized. To solve
this, we first calculate the necessary offsets using just the type which
is side-effect free and does not alter the LLVM IR. Then, if we are in a
situation which requires us to generate the LLVM IR (and this situation
only occurs for arguments, not local variables) then we perform the same
calculation again, this time generating the appropriate LLVM IR as we
go.
This commit adds LLVM Kernel Control Flow Integrity (KCFI) support to
the Rust compiler. It initially provides forward-edge control flow
protection for operating systems kernels for Rust-compiled code only by
aggregating function pointers in groups identified by their return and
parameter types. (See llvm/llvm-project@cff5bef.)
Forward-edge control flow protection for C or C++ and Rust -compiled
code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code
share the same virtual address space) will be provided in later work as
part of this project by identifying C char and integer type uses at the
time types are encoded (see Type metadata in the design document in the
tracking issue #89653).
LLVM KCFI can be enabled with -Zsanitizer=kcfi.
Co-authored-by: bjorn3 <17426603+bjorn3@users.noreply.github.com>
rustc_codegen_ssa: Fix for codegen_get_discr
When doing the optimized implementation of getting the discriminant, the arithmetic needs to be done in the tag type so wrapping behavior works correctly.
Fixes#104519
rustc_codegen_ssa: write `.dwp` in a streaming fashion
When writing a `.dwp` file, rustc writes to a Vec first then to a BufWriter-wrapped file. It seems very likely that we can write in a streaming fashion to avoid double buffering in an intermediate Vec.
On my Linux machine, `.dwp` from the latest rust-lang/cargo is 113MiB. It may worth a stream writer, though I didn't do any benchmark 🙇🏾♂️.
deduplicate constant evaluation in cranelift backend
The cranelift backend had two matches on `ConstantKind`, which can be avoided, and used this `eval_for_mir` that nothing else uses... this makes things more consistent with the (better-tested) LLVM backend.
I noticed this because cranelift was the only user of `eval_for_mir`. However `try_eval_for_mir` still has one other user in `eval`... the odd thing is that the interpreter has its own `eval_mir_constant` which seems to duplicate the same functionality and does not use `try_eval_for_mir`. No idea what is happening here.
r? ``@bjorn3``
Cc ``@lcnr``
Improve generating Custom entry function
This commit is aimed at making compiler-generated entry functions (Basically just C `main` right now) more generic so other targets can do similar things for custom entry. This was initially implemented as part of https://github.com/rust-lang/rust/pull/100316.
Currently, this moves the entry function name and Call convention to the target spec.
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
When doing the optimized implementation of getting the discriminant, the
arithmetic needs to be done in the tag type so wrapping behavior works
correctly.
Fixes#104519
Record `LocalDefId` in HIR nodes instead of a side table
This is part of an attempt to remove the `HirId -> LocalDefId` table from HIR.
This attempt is a prerequisite to creation of `LocalDefId` after HIR lowering (https://github.com/rust-lang/rust/pull/96840), by controlling how `def_id` information is accessed.
This first part adds the information to HIR nodes themselves instead of a table.
The second part is https://github.com/rust-lang/rust/pull/103902
The third part will be to make `hir::Visitor::visit_fn` take a `LocalDefId` as last parameter.
The fourth part will be to completely remove the side table.
cleanup and dedupe CTFE and Miri error reporting
It looks like most of the time, this error raised from const_prop_lint is just redundant -- it duplicates the error reported when evaluating the const-eval query. This lets us make `ConstEvalErr` private to the const_eval module which I think is a good step.
The Miri change mostly replaces a `match` by `if let`, and dedupes the "this error is impossible in Miri" checks.
r? ``@oli-obk``
Fixes https://github.com/rust-lang/rust/issues/75461
Issue error when -C link-self-contained option is used on unsupported platforms
The documentation was also updated to reflect this.
I'm assuming the supported platforms are the same as initially written in [RELEASES.md](https://github.com/rust-lang/rust/blob/master/RELEASES.md#compiler-17).
Fixes#103576
Fix some misleading target feature aliases
This is the first half of a fix for #100752. It looks like these aliases were added in #78361 and slipped under the radar, as these features are not AVX512. These features _do_ add AVX512 instructions when used _in combination_ with AVX512F, but without AVX512F, these features still provide 128-bit and 256-bit vector instructions. A user might be mislead into thinking these features imply AVX512F (which is true of the actual AVX512 features). This PR allows using the names as defined by LLVM, which matches Intel documentation.
A future PR should change the `std::arch` intrinsics to use these names, and finally remove these aliases from rustc.
r? ```@workingjubilee```
cc ```@Amanieu```
In `codegen_assert_terminator` we decide if a BB's successor is a
candidate for merging, which requires that it be the only successor, and
that it only have one predecessor. That result then gets passed down,
and if it reaches `funclet_br` with the appropriate BB characteristics,
then no `br` instruction is issued, a `MergingSucc::True` result is
passed back, and the merging proceeds in `codegen_block`.
The commit also adds `CachedLlbb`, a new type to help keep track of
each BB that has been merged into its predecessor.
For the next commit, `FunctionCx::codegen_*_terminator` need to take a
`&mut Bx` instead of consuming a `Bx`. This triggers a cascade of
similar changes across multiple functions. The resulting code is more
concise and replaces many `&mut bx` expressions with `bx`.
