`Layout` is another type that is sometimes interned, sometimes not, and
we always use references to refer to it so we can't take any advantage
of the uniqueness properties for hashing or equality checks.
This commit renames `Layout` as `LayoutS`, and then introduces a new
`Layout` that is a newtype around an `Interned<LayoutS>`. It also
interns more layouts than before. Previously layouts within layouts
(via the `variants` field) were never interned, but now they are. Hence
the lifetime on the new `Layout` type.
Unlike other interned types, these ones are in `rustc_target` instead of
`rustc_middle`. This reflects the existing structure of the code, which
does layout-specific stuff in `rustc_target` while `TyAndLayout` is
generic over the `Ty`, allowing the type-specific stuff to occur in
`rustc_middle`.
The commit also adds a `HashStable` impl for `Interned`, which was
needed. It hashes the contents, unlike the `Hash` impl which hashes the
pointer.
`Layout` is another type that is sometimes interned, sometimes not, and
we always use references to refer to it so we can't take any advantage
of the uniqueness properties for hashing or equality checks.
This commit renames `Layout` as `LayoutS`, and then introduces a new
`Layout` that is a newtype around an `Interned<LayoutS>`. It also
interns more layouts than before. Previously layouts within layouts
(via the `variants` field) were never interned, but now they are. Hence
the lifetime on the new `Layout` type.
Unlike other interned types, these ones are in `rustc_target` instead of
`rustc_middle`. This reflects the existing structure of the code, which
does layout-specific stuff in `rustc_target` while `TyAndLayout` is
generic over the `Ty`, allowing the type-specific stuff to occur in
`rustc_middle`.
The commit also adds a `HashStable` impl for `Interned`, which was
needed. It hashes the contents, unlike the `Hash` impl which hashes the
pointer.
Introduce `ConstAllocation`.
Currently some `Allocation`s are interned, some are not, and it's very
hard to tell at a use point which is which.
This commit introduces `ConstAllocation` for the known-interned ones,
which makes the division much clearer. `ConstAllocation::inner()` is
used to get the underlying `Allocation`.
In some places it's natural to use an `Allocation`, in some it's natural
to use a `ConstAllocation`, and in some places there's no clear choice.
I've tried to make things look as nice as possible, while generally
favouring `ConstAllocation`, which is the type that embodies more
information. This does require quite a few calls to `inner()`.
The commit also tweaks how `PartialOrd` works for `Interned`. The
previous code was too clever by half, building on `T: Ord` to make the
code shorter. That caused problems with deriving `PartialOrd` and `Ord`
for `ConstAllocation`, so I changed it to build on `T: PartialOrd`,
which is slightly more verbose but much more standard and avoided the
problems.
r? `@fee1-dead`
Currently some `Allocation`s are interned, some are not, and it's very
hard to tell at a use point which is which.
This commit introduces `ConstAllocation` for the known-interned ones,
which makes the division much clearer. `ConstAllocation::inner()` is
used to get the underlying `Allocation`.
In some places it's natural to use an `Allocation`, in some it's natural
to use a `ConstAllocation`, and in some places there's no clear choice.
I've tried to make things look as nice as possible, while generally
favouring `ConstAllocation`, which is the type that embodies more
information. This does require quite a few calls to `inner()`.
The commit also tweaks how `PartialOrd` works for `Interned`. The
previous code was too clever by half, building on `T: Ord` to make the
code shorter. That caused problems with deriving `PartialOrd` and `Ord`
for `ConstAllocation`, so I changed it to build on `T: PartialOrd`,
which is slightly more verbose but much more standard and avoided the
problems.
Currently some `Allocation`s are interned, some are not, and it's very
hard to tell at a use point which is which.
This commit introduces `ConstAllocation` for the known-interned ones,
which makes the division much clearer. `ConstAllocation::inner()` is
used to get the underlying `Allocation`.
In some places it's natural to use an `Allocation`, in some it's natural
to use a `ConstAllocation`, and in some places there's no clear choice.
I've tried to make things look as nice as possible, while generally
favouring `ConstAllocation`, which is the type that embodies more
information. This does require quite a few calls to `inner()`.
The commit also tweaks how `PartialOrd` works for `Interned`. The
previous code was too clever by half, building on `T: Ord` to make the
code shorter. That caused problems with deriving `PartialOrd` and `Ord`
for `ConstAllocation`, so I changed it to build on `T: PartialOrd`,
which is slightly more verbose but much more standard and avoided the
problems.
explain why shift with signed offset works the way it does
I was worried for a bit here that Miri/CTFE would be inconsistent with codegen, but I *think* everything is all right, actually.
Cc `@oli-obk` `@eddyb`
Always include global target features in function attributes
This ensures that information about target features configured with
`-C target-feature=...` or detected with `-C target-cpu=native` is
retained for subsequent consumers of LLVM bitcode.
This is crucial for linker plugin LTO, since this information is not
conveyed to the plugin otherwise.
<details><summary>Additional test case demonstrating the issue</summary>
```rust
extern crate core;
#[inline]
#[target_feature(enable = "aes")]
unsafe fn f(a: u128, b: u128) -> u128 {
use core::arch::x86_64::*;
use core::mem::transmute;
transmute(_mm_aesenc_si128(transmute(a), transmute(b)))
}
pub fn g(a: u128, b: u128) -> u128 {
unsafe { f(a, b) }
}
fn main() {
let mut args = std::env::args();
let _ = args.next().unwrap();
let a: u128 = args.next().unwrap().parse().unwrap();
let b: u128 = args.next().unwrap().parse().unwrap();
println!("{}", g(a, b));
}
```
```console
$ rustc --edition=2021 a.rs -Clinker-plugin-lto -Clink-arg=-fuse-ld=lld -Ctarget-feature=+aes -O
...
= note: LLVM ERROR: Cannot select: intrinsic %llvm.x86.aesni.aesenc
```
</details>
r? `@nagisa`
Improve rustdoc const bounds
- Rustdoc no longer displays `~const` in trait bounds, because it currently means nothing for stable users, and because we still haven't decided on the final syntax yet.
- Rustdoc will hide trait bounds where the trait is `Drop` AND it is `~const`, i.e. `~const Drop` bounds because it has no effect on stable users as well.
- Because of additional logic that hides the whole `where` statement where it consists of `~const Drop` bounds (so it doesn't display `struct Foo<T>() where ;` like that), bounds that have no trait e.g. `where [T; N+1]: ;` are also hidden.
Cherry-picked from #92433.
Unix path::absolute: Fix leading "." component
Testing leading `.` and `..` components were missing from the unix tests.
This PR adds them and fixes the leading `.` case. It also fixes the test cases so that they do an exact comparison.
This problem reported by ``@axetroy``
rustbuild: support RelWithDebInfo for lld
r? ``@alexcrichton``
LLVM has flags that control the level of debuginfo generated when building via rustbuild. Since LLD is built separately, it currently has no way of generating any debuginfo. This change re-uses the same flags as LLVM for LLD to ensure it has the same level of debuginfo generated as LLVM.
Llint for casting between raw slice pointers with different element sizes
This lint disallows using `as` to convert from a raw pointer to a slice (e.g. `*const [i32]`, `*mut [Foo]`) to any other raw pointer to a slice if the element types have different sizes. When a raw slice pointer is cast, the data pointer and count metadata are preserved. This means that when the size of the inner slice's element type changes, the total number of bytes pointed to by the count changes. For example a `*const [i32]` with length 4 (four `i32` elements) is cast `as *const [u8]` the resulting pointer points to four `u8` elements at the same address, losing most of the data. When the size *increases* the resulting pointer will point to *more* data, and accessing that data will be UB.
On its own, *producing* the pointer isn't actually a problem, but because any use of the pointer as a slice will either produce surprising behavior or cause UB I believe this is a correctness lint. If the pointer is not intended to be used as a slice, the user should instead use any of a number of methods to produce just a data pointer including an `as` cast to a thin pointer (e.g. `p as *const i32`) or if the pointer is being created from a slice, the `as_ptr` method on slices. Detecting the intended use of the pointer is outside the scope of this lint, but I believe this lint will also lead users to realize that a slice pointer is only for slices.
There is an exception to this lint when either of the slice element types are zero sized (e.g `*mut [()]`). The total number of bytes pointed to by the slice with a zero sized element is zero. In that case preserving the length metadata is likely intended as a workaround to get the length metadata of a slice pointer though a zero sized slice.
The lint does not forbid casting pointers to slices with the *same* element size as the cast was likely intended to reinterpret the data in the slice as some equivalently sized data and the resulting pointer will behave as intended.
---
changelog: Added ``[`cast_slice_different_sizes`]``, a lint that disallows using `as`-casts to convert between raw pointers to slices when the elements have different sizes.
rustdoc: Stop textually replacing `Self` in doc links before resolving them
Resolve it directly to a type / def-id instead.
Also never pass `Self` to `Resolver`, it is useless because it's guaranteed that no resolution will be found.
This is a pre-requisite for https://github.com/rust-lang/rust/issues/83761.
add address sanitizer fo android
We have been being using asan to debug the rust/cpp/c mixed android application in production for months: recompile the rust library with a patched rustc, everything just works fine. The patch is really small thanks to `@nagisa` 's refactoring in https://github.com/rust-lang/rust/pull/81866
r? `@nagisa`
