| Age | Commit message (Collapse) | Author | Lines |
|---|
|
Initial implementation of transmutability trait.
*T'was the night before Christmas and all through the codebase, not a miri was stirring — no hint of `unsafe`!*
This PR provides an initial, **incomplete** implementation of *[MCP 411: Lang Item for Transmutability](https://github.com/rust-lang/compiler-team/issues/411)*. The `core::mem::BikeshedIntrinsicFrom` trait provided by this PR is implemented on-the-fly by the compiler for types `Src` and `Dst` when the bits of all possible values of type `Src` are safely reinterpretable as a value of type `Dst`.
What this PR provides is:
- [x] [support for transmutations involving primitives](https://github.com/jswrenn/rust/tree/transmute/src/test/ui/transmutability/primitives)
- [x] [support for transmutations involving arrays](https://github.com/jswrenn/rust/tree/transmute/src/test/ui/transmutability/arrays)
- [x] [support for transmutations involving structs](https://github.com/jswrenn/rust/tree/transmute/src/test/ui/transmutability/structs)
- [x] [support for transmutations involving enums](https://github.com/jswrenn/rust/tree/transmute/src/test/ui/transmutability/enums)
- [x] [support for transmutations involving unions](https://github.com/jswrenn/rust/tree/transmute/src/test/ui/transmutability/unions)
- [x] [support for weaker validity checks](https://github.com/jswrenn/rust/blob/transmute/src/test/ui/transmutability/unions/should_permit_intersecting_if_validity_is_assumed.rs) (i.e., `Assume::VALIDITY`)
- [x] visibility checking
What isn't yet implemented:
- [ ] transmutability options passed using the `Assume` struct
- [ ] [support for references](https://github.com/jswrenn/rust/blob/transmute/src/test/ui/transmutability/references.rs)
- [ ] smarter error messages
These features will be implemented in future PRs.
|
|
This adds a new option, `-Zmir-pretty-relative-line-numbers`, that
is then used in compiletest for the mir-opt tests.
|
|
This initial implementation handles transmutations between types with specified layouts, except when references are involved.
Co-authored-by: Igor null <m1el.2027@gmail.com>
|
|
Some command-line options accessible through `sess.opts` are best
accessed through wrapper functions on `Session`, `TyCtxt` or otherwise,
rather than through field access on the option struct in the `Session`.
Adds a new lint which triggers on those options that should be accessed
through a wrapper function so that this is prohibited. Options are
annotated with a new attribute `rustc_lint_opt_deny_field_access` which
can specify the error message (i.e. "use this other function instead")
to be emitted.
A simpler alternative would be to simply rename the options in the
option type so that it is clear they should not be used, however this
doesn't prevent uses, just discourages them. Another alternative would
be to make the option fields private, and adding accessor functions on
the option types, however the wrapper functions sometimes rely on
additional state from `Session` or `TyCtxt` which wouldn't be available
in an function on the option type, so the accessor would simply make the
field available and its use would be discouraged too.
Signed-off-by: David Wood <david.wood@huawei.com>
|
|
codegen: use new {re,de,}allocator annotations in llvm
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
r? `@nikic`
|
|
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
While we're here, we also emit allocator attributes on
__rust_alloc_zeroed. This should allow LLVM to perform more
optimizations for zeroed blocks, and probably fixes #90032. [This
comment](https://github.com/rust-lang/rust/issues/24194#issuecomment-308791157)
mentions "weird UB-like behaviour with bitvec iterators in
rustc_data_structures" so we may need to back this change out if things
go wrong.
The new test cases require LLVM 15, so we copy them into LLVM
14-supporting versions, which we can delete when we drop LLVM 14.
|
|
This attribute allows to mark default body of a trait function as
unstable. This means that implementing the trait without implementing
the function will require enabling unstable feature.
This is useful in conjunction with `#[rustc_must_implement_one_of]`,
we may want to relax requirements for a trait, for example allowing
implementing either of `PartialEq::{eq, ne}`, but do so in a safe way
-- making implementation of only `PartialEq::ne` unstable.
|
|
r=michaelwoerister
Avoid `&str`/`Symbol` to `String` conversions
follow-up to #99342 and #98668
|
|
|
|
rmeta: avoid embedding `StabilityLevel::Unstable` reason multiple times into .rmeta\.rlib files
Avoids bloating size of some rmeta\rlib files by not placing default string for `StabilityLevel::Unstable` reason multiple times, affects only stdlib\rustc artifacts. For stdlib cuts about 3% (diff of total size for patched\unpatched *.rmeta files of stage1-std) of file size, depending on crates.
fixes #88180
|
|
Add support for LLVM ShadowCallStack.
LLVMs ShadowCallStack provides backward edge control flow integrity protection by using a separate shadow stack to store and retrieve a function's return address.
LLVM currently only supports this for AArch64 targets. The x18 register is used to hold the pointer to the shadow stack, and therefore this only works on ABIs which reserve x18. Further details are available in the [LLVM ShadowCallStack](https://clang.llvm.org/docs/ShadowCallStack.html) docs.
# Usage
`-Zsanitizer=shadow-call-stack`
# Comments/Caveats
* Currently only enabled for the aarch64-linux-android target
* Requires the platform to define a runtime to initialize the shadow stack, see the [LLVM docs](https://clang.llvm.org/docs/ShadowCallStack.html) for more detail.
|
|
|
|
make vtable pointers entirely opaque
This implements the scheme discussed in https://github.com/rust-lang/unsafe-code-guidelines/issues/338: vtable pointers should be considered entirely opaque and not even readable by Rust code, similar to function pointers.
- We have a new kind of `GlobalAlloc` that symbolically refers to a vtable.
- Miri uses that kind of allocation when generating a vtable.
- The codegen backends, upon encountering such an allocation, call `vtable_allocation` to obtain an actually dataful allocation for this vtable.
- We need new intrinsics to obtain the size and align from a vtable (for some `ptr::metadata` APIs), since direct accesses are UB now.
I had to touch quite a bit of code that I am not very familiar with, so some of this might not make much sense...
r? `@oli-obk`
|
|
multiple times
|
|
|
|
Adds a simple helper function to the `SourceMap` for extending a `Span`
to encompass the entire line it is on - useful for suggestions where
removing a line is the suggested action.
Signed-off-by: David Wood <david.wood@huawei.com>
|
|
If part of a feature is stabilized and a new feature is added for the
remaining parts, then the `implied_by` attribute can be used to indicate
which now-stable feature previously contained a item. If the now-stable
feature is still active (if the user has only just updated rustc, for
example) then there will not be an stability error for uses of the item
from the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
|
|
Adds support for the LLVM ShadowCallStack sanitizer.
|
|
r=petrochenkov,GuillaumeGomez
Improve the function pointer docs
This is #97842 but for function pointers instead of tuples. The concept is basically the same.
* Reduce duplicate impls; show `fn (T₁, T₂, …, Tₙ)` and include a sentence saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
https://notriddle.com/notriddle-rustdoc-test/std/primitive.fn.html
|
|
Improve suggestions for `NonZeroT` <- `T` coercion error
Currently, when encountering a type mismatch error with `NonZeroT` and `T` (for example `NonZeroU8` and `u8`) we errorneusly suggest wrapping expression in `NonZeroT`:
```text
error[E0308]: mismatched types
--> ./t.rs:7:35
|
7 | let _: std::num::NonZeroU64 = 1;
| -------------------- ^ expected struct `NonZeroU64`, found integer
| |
| expected due to this
|
help: try wrapping the expression in `std::num::NonZeroU64`
|
7 | let _: std::num::NonZeroU64 = std::num::NonZeroU64(1);
| +++++++++++++++++++++ +
```
I've removed this suggestion and added suggestions to call `new` (for `Option<NonZeroT>` <- `T` case) or `new` and `unwrap` (for `NonZeroT` <- `T` case):
```text
error[E0308]: mismatched types
--> ./t.rs:7:35
|
7 | let _: std::num::NonZeroU64 = 1;
| -------------------- ^ expected struct `NonZeroU64`, found integer
| |
| expected due to this
|
help: Consider calling `NonZeroU64::new`
|
7 | let _: std::num::NonZeroU64 = NonZeroU64::new(1).unwrap();
| ++++++++++++++++ ++++++++++
error[E0308]: mismatched types
--> ./t.rs:8:43
|
8 | let _: Option<std::num::NonZeroU64> = 1;
| ---------------------------- ^ expected enum `Option`, found integer
| |
| expected due to this
|
= note: expected enum `Option<NonZeroU64>`
found type `{integer}`
help: Consider calling `NonZeroU64::new`
|
8 | let _: Option<std::num::NonZeroU64> = NonZeroU64::new(1);
| ++++++++++++++++ +
```
r? `@compiler-errors`
|
|
Avoid `Symbol` to `&str` conversions
`Symbol::as_str` is a slowish operation, so this patch removes some usages of it.
|
|
|
|
|
|
The attribute is also renamed `fake_variadic`.
|
|
r=cjgillot
Refactor: remove a string matching about methods
This patch remove a string matching about methods and adds some rustfix tests.
|
|
|
|
Support unstable moves via stable in unstable items
part of https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/moving.20items.20to.20core.20unstably and a blocker of https://github.com/rust-lang/rust/pull/90328.
The libs-api team needs the ability to move an already stable item to a new location unstably, in this case for Error in core. Otherwise these changes are insta-stable making them much harder to merge.
This PR attempts to solve the problem by checking the stability of path segments as well as the last item in the path itself, which is currently the only thing checked.
|
|
Rollup of 5 pull requests
Successful merges:
- #97720 (Always create elided lifetime parameters for functions)
- #98315 (Stabilize `core::ffi:c_*` and rexport in `std::ffi`)
- #98705 (Implement `for<>` lifetime binder for closures)
- #99126 (remove allow(rustc::potential_query_instability) in rustc_span)
- #99139 (Give a better error when `x dist` fails for an optional tool)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
|
|
remove allow(rustc::potential_query_instability) in rustc_span
Also, avoid sorting before debug output as iteration order can now be
relied upon.
Related #84447
|
|
Implement `for<>` lifetime binder for closures
This PR implements RFC 3216 ([TI](https://github.com/rust-lang/rust/issues/97362)) and allows code like the following:
```rust
let _f = for<'a, 'b> |a: &'a A, b: &'b B| -> &'b C { b.c(a) };
// ^^^^^^^^^^^--- new!
```
cc ``@Aaron1011`` ``@cjgillot``
|
|
Always create elided lifetime parameters for functions
Anonymous and elided lifetimes in functions are sometimes (async fns) --and sometimes not (regular fns)-- desugared to implicit generic parameters.
This difference of treatment makes it some downstream analyses more complicated to handle. This step is a pre-requisite to perform lifetime elision resolution on AST.
There is currently an inconsistency in the treatment of argument-position impl-trait for functions and async fns:
```rust
trait Foo<'a> {}
fn foo(t: impl Foo<'_>) {} //~ ERROR missing lifetime specifier
async fn async_foo(t: impl Foo<'_>) {} //~ OK
fn bar(t: impl Iterator<Item = &'_ u8>) {} //~ ERROR missing lifetime specifier
async fn async_bar(t: impl Iterator<Item = &'_ u8>) {} //~ OK
```
The current implementation reports "missing lifetime specifier" on `foo`, but **accepts it** in `async_foo`.
This PR **proposes to accept** the anonymous lifetime in both cases as an extra generic lifetime parameter.
This change would be insta-stable, so let's ping t-lang.
Anonymous lifetimes in GAT bindings keep being forbidden:
```rust
fn foo(t: impl Foo<Assoc<'_> = Bar<'_>>) {}
^^ ^^
forbidden ok
```
I started a discussion here: https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Anonymous.20lifetimes.20in.20universal.20impl-trait/near/284968606
r? ``@petrochenkov``
|
|
This is no longer used only for debugging options (e.g. `-Zoutput-width`, `-Zallow-features`).
Rename it to be more clear.
|
|
|
|
`UnsafeCell` blocks niches inside its nested type from being available outside
fixes #87341
This implements the plan by `@eddyb` in https://github.com/rust-lang/rust/issues/87341#issuecomment-886083646
Somewhat related PR (not strictly necessary, but that cleanup made this PR simpler): #94527
|
|
|
|
This is first step in implementing RFC 3216.
- Parse `for<'a>` before closures in ast
- Error in lowering
- Add `closure_lifetime_binder` feature
|
|
|
|
Implement `SourceMap::is_span_accessible`
This patch adds `SourceMap::is_span_accessible` and replaces `span_to_snippet(span).is_ok()` and `span_to_snippet(span).is_err()` with it. This removes a `&str` to `String` conversion.
|
|
|
|
|
|
Avoid some `&str` to `String` conversions
This patch removes some `&str` to `String` conversions.
|
|
|
|
Miscellaneous inlining improvements
Add `#[inline]` to a few trivial non-generic methods from a perf report
that otherwise wouldn't be candidates for inlining.
|
|
|
|
Use less string interning
This removes string interning in a couple of places where doing so won't result in perf improvements. I also switched one place to use pre-interned symbols.
|
|
Add `#[inline]` to a few trivial non-generic methods from a perf report
that otherwise wouldn't be candidates for inlining.
|
|
|
|
Add a new trait to be generated by diagnostic derives which uses a
`LintDiagnosticBuilder`.
Signed-off-by: David Wood <david.wood@huawei.com>
|
|
Improve some deriving code and add a test
The `.stdout` test is particularly useful.
r? `@petrochenkov`
|
|
|
