Prevent unwinding when `-C panic=abort` is used regardless declared ABI
Ensures that Rust code will abort with `-C panic=abort` regardless ABI used.
```rust
extern "C-unwind" {
fn may_unwind();
}
// Will be nounwind with `-C panic=abort`, despite `C-unwind` ABI.
pub unsafe extern "C-unwind" fn rust_item_that_can_unwind() {
may_unwind();
}
```
Current behaviour is that unwind will propagate through. While the current behaviour won't cause unsoundness it is inconsistent with the text reading of [RFC2945](https://rust-lang.github.io/rfcs/2945-c-unwind-abi.html).
I tweaked `fn_can_unwind` instead of tweaking `AbortUnwindingCalls` because this approach would allow Rust (non-direct) callers to also see that this function is nounwind, so it can prevent excessive landing pads generation.
For more discussions: https://rust-lang.zulipchat.com/#narrow/stream/210922-project-ffi-unwind/topic/soundness.20in.20mixed.20panic.20mode.
cc `@alexcrichton,` `@BatmanAoD`
r? `@Amanieu`
`@rustbot` label: T-compiler T-lang F-c_unwind
Change `Successors` to `impl Iterator<Item = BasicBlock>`
This PR fixes the FIXME in `compiler\rustc_middle\src\mir\mod.rs`.
This can omit several `&`, `*` or `cloned` operations on Successros' generated elements
Add a query for checking whether a function is an intrinsic.
work towards #93145
This will reduce churn when we add more ways to declare intrinsics
r? `@scottmcm`
Add EarlyBinder
Chalk has no concept of `Param` (e0ade19d13/chalk-ir/src/lib.rs (L579)) or `ReEarlyBound` (e0ade19d13/chalk-ir/src/lib.rs (L1308)). Everything is just "bound" - the equivalent of rustc's late-bound. It's not completely clear yet whether to move everything to the same time of binder in rustc or add `Param` and `ReEarlyBound` in Chalk.
Either way, tracking when we have or haven't already substituted out these in rustc can be helpful.
As a first step, I'm just adding a `EarlyBinder` newtype that is required to call `subst`. I also add a couple "transparent" `bound_*` wrappers around a couple query that are often immediately substituted.
r? `@nikomatsakis`
Initial work on Miri permissive-exposed-provenance
Rustc portion of the changes for portions of a permissive ptr-to-int model for Miri. The main changes here are changing `ptr_get_alloc` and `get_alloc_id` to return an Option, and also making ptr-to-int casts have an expose side effect.
don't encode only locally used attrs
Part of https://github.com/rust-lang/compiler-team/issues/505.
We now filter builtin attributes before encoding them in the crate metadata in case they should only be used in the local crate. To prevent accidental misuse `get_attrs` now requires the caller to state which attribute they are interested in. For places where that isn't trivially possible, I've added a method `fn get_attrs_unchecked` which I intend to remove in a followup PR.
After this pull request landed, we can then slowly move all attributes to only be used in the local crate while being certain that we don't accidentally try to access them from extern crates.
cc https://github.com/rust-lang/rust/pull/94963#issuecomment-1082924289
Remove `PartialOrd`/`Ord` impl for `PlaceRef`
This is a new attempt at #93315. It removes one usage
of the `Ord` impl for `DefId`, which should make it easier
to eventually remove that impl.
Implement a lint to warn about unused macro rules
This implements a new lint to warn about unused macro rules (arms/matchers), similar to the `unused_macros` lint added by #41907 that warns about entire macros.
```rust
macro_rules! unused_empty {
(hello) => { println!("Hello, world!") };
() => { println!("empty") }; //~ ERROR: 1st rule of macro `unused_empty` is never used
}
fn main() {
unused_empty!(hello);
}
```
Builds upon #96149 and #96156.
Fixes#73576
Gracefully fail to resolve associated items instead of `delay_span_bug`.
`codegen_fulfill_obligation` is used during instance resolution for trait items.
In case of insufficient normalization issues during MIR inlining, it caused ICEs.
It's better to gracefully refuse to resolve the associated item, and let the caller decide what to do with this.
Split from https://github.com/rust-lang/rust/pull/91743Closes#69121Closes#73021Closes#88599Closes#93008Closes#93248Closes#94680Closes#96170
r? `@oli-obk`
make sure ScalarPair enums have ScalarPair variants; add some layout sanity checks
`@eddyb` suggested that it might be reasonable for `ScalarPair` enums to simply adjust the ABI of their variants accordingly, such that the layout invariant Miri expects actually holds. This PR implements that. I should note though that I don't know much about this layout computation code and what non-Miri consumers expect from it, so tread with caution!
I also added a function to sanity-check that computed layouts are internally consistent. This helped a lot in figuring out the final shape of this PR, though I am also not 100% sure that these sanity checks are the right ones.
Cc `@oli-obk`
Fixes https://github.com/rust-lang/rust/issues/96221
Optimize switch sources representation and usage
* Avoid constructing switch sources unless necessary - switch sources are used by backward analysis with a custom switch int edge effects, but are otherwise unnecessarily computed.
* Use sparse representation of switch sources to avoid quadratic space overhead.
Some subst cleanup
Two separate things here. Both changes are useful for some refactoring I'm doing to add an "EarlyBinder" newtype. (Part of chalkification).
1) Remove `subst_spanned` and just use `subst`. It wasn't used much anyways. In practice, I think we can probably get most of the info just from the actual error message. If not, outputting logs should do the trick. (The specific line probably wouldn't help much anyways).
2) Call `.subst()` before `replace_bound_vars_with_fresh_vars` and `erase_late_bound_regions` in three places that do the opposite. I think there might have been some time in the past that the order here matter for something, but this shouldn't be the case anymore. Conceptually, it makes more sense to the of the *early bound* vars on `fn`s as "outside" the late bound vars.
Remove `#[rustc_deprecated]`
This removes `#[rustc_deprecated]` and introduces diagnostics to help users to the right direction (that being `#[deprecated]`). All uses of `#[rustc_deprecated]` have been converted. CI is expected to fail initially; this requires #95958, which includes converting `stdarch`.
I plan on following up in a short while (maybe a bootstrap cycle?) removing the diagnostics, as they're only intended to be short-term.
Switch sources are used by backward analysis with a custom switch int
edge effects, but are otherwise unnecessarily computed.
Delay the computation until we know that switch sources are indeed
required and avoid the computation otherwise.
make Size and Align debug-printing a bit more compact
In particular in `{:#?}`-mode, these take up a lot of space, so I think this is the better alternative (even though it is a bit longer in `{:?}` mode, I think it is still more readable).
We could make it even smaller by deviating further from what the actual code looks like, e.g. via something like `Size(4 bytes)`. Not sure what people would think about that?
Cc `````@oli-obk`````
Begin fixing all the broken doctests in `compiler/`
Begins to fix#95994.
All of them pass now but 24 of them I've marked with `ignore HELP (<explanation>)` (asking for help) as I'm unsure how to get them to work / if we should leave them as they are.
There are also a few that I marked `ignore` that could maybe be made to work but seem less important.
Each `ignore` has a rough "reason" for ignoring after it parentheses, with
- `(pseudo-rust)` meaning "mostly rust-like but contains foreign syntax"
- `(illustrative)` a somewhat catchall for either a fragment of rust that doesn't stand on its own (like a lone type), or abbreviated rust with ellipses and undeclared types that would get too cluttered if made compile-worthy.
- `(not-rust)` stuff that isn't rust but benefits from the syntax highlighting, like MIR.
- `(internal)` uses `rustc_*` code which would be difficult to make work with the testing setup.
Those reason notes are a bit inconsistently applied and messy though. If that's important I can go through them again and try a more principled approach. When I run `rg '```ignore \(' .` on the repo, there look to be lots of different conventions other people have used for this sort of thing. I could try unifying them all if that would be helpful.
I'm not sure if there was a better existing way to do this but I wrote my own script to help me run all the doctests and wade through the output. If that would be useful to anyone else, I put it here: https://github.com/Elliot-Roberts/rust_doctest_fixing_tool
Allow inline consts to reference generic params
Tracking issue: #76001
The RFC says that inline consts cannot reference to generic parameters (for now), same as array length expressions. And expresses that it's desirable for it to reference in-scope generics, when array length expressions gain that feature as well.
However it is possible to implement this for inline consts before doing this for all anon consts, because inline consts are only used as values and they won't be used in the type system. So we can have:
```rust
fn foo<T>() {
let x = [4i32; std::mem::size_of::<T>()]; // NOT ALLOWED (for now)
let x = const { std::mem::size_of::<T>() }; // ALLOWED with this PR!
let x = [4i32; const { std::mem::size_of::<T>() }]; // NOT ALLOWED (for now)
}
```
This would make inline consts super useful for compile-time checks and assertions:
```rust
fn assert_zst<T>() {
const { assert!(std::mem::size_of::<T>() == 0) };
}
```
This would create an error during monomorphization when `assert_zst` is instantiated with non-ZST `T`s. A error during mono might sound scary, but this is exactly what a "desugared" inline const would do:
```rust
fn assert_zst<T>() {
struct F<T>(T);
impl<T> F<T> {
const V: () = assert!(std::mem::size_of::<T>() == 0);
}
let _ = F::<T>::V;
}
```
It should also be noted that the current inline const implementation can already reference the type params via type inference, so this resolver-level restriction is not any useful either:
```rust
fn foo<T>() -> usize {
let (_, size): (PhantomData<T>, usize) = const {
const fn my_size_of<T>() -> (PhantomData<T>, usize) {
(PhantomData, std::mem::size_of::<T>())
}
my_size_of()
};
size
}
```
```@rustbot``` label: F-inline_const
Add a new Rust attribute to support embedding debugger visualizers
Implemented [this RFC](https://github.com/rust-lang/rfcs/pull/3191) to add support for embedding debugger visualizers into a PDB.
Added a new attribute `#[debugger_visualizer]` and updated the `CrateMetadata` to store debugger visualizers for crate dependencies.
RFC: https://github.com/rust-lang/rfcs/pull/3191
Cleanup `DebuggerVisualizerFile` type and other minor cleanup of queries.
Merge the queries for debugger visualizers into a single query.
Revert move of `resolve_path` to `rustc_builtin_macros`. Update dependencies in Cargo.toml for `rustc_passes`.
Respond to PR comments. Load visualizer files into opaque bytes `Vec<u8>`. Debugger visualizers for dynamically linked crates should not be embedded in the current crate.
Update the unstable book with the new feature. Add the tracking issue for the debugger_visualizer feature.
Respond to PR comments and minor cleanups.
Update `RValue::Discriminant` documentation
`RValue::Discriminant` returns zero for types without discriminant.
This guarantee is already documented for `discriminant_value`
intrinsics which is implemented in terms of `RValue::Discriminant`.
Only crate root def-ids don't have a parent, and in majority of cases the argument of `DefIdTree::parent` cannot be a crate root.
So we now panic by default in `parent` and introduce a new non-panicing function `opt_parent` for cases where the argument can be a crate root.
Same applies to `local_parent`/`opt_local_parent`.
`RValue::Discriminant` returns zero for types without discriminant.
This guarantee is already documented for `discriminant_value`
intrinsics which is implemented in terms of `RValue::Discriminant`.
Reduce duplication of RPO calculation of mir
Computing the RPO of mir is not a low-cost thing, but it is duplicate in many places. In particular the `iterate_to_fixpoint` method which is called multiple times when computing the data flow.
This PR reduces the number of times the RPO is recalculated as much as possible, which should save some compile time.
