Tweak `.clone()` suggestion to work in more cases
When going through auto-deref, the `<T as Clone>` impl sometimes needs to be specified for rustc to actually clone the value and not the reference.
```
error[E0507]: cannot move out of dereference of `S`
--> $DIR/needs-clone-through-deref.rs:15:18
|
LL | for _ in self.clone().into_iter() {}
| ^^^^^^^^^^^^ ----------- value moved due to this method call
| |
| move occurs because value has type `Vec<usize>`, which does not implement the `Copy` trait
|
note: `into_iter` takes ownership of the receiver `self`, which moves value
--> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
help: you can `clone` the value and consume it, but this might not be your desired behavior
|
LL | for _ in <Vec<usize> as Clone>::clone(&self.clone()).into_iter() {}
| ++++++++++++++++++++++++++++++ +
```
When encountering a move error, look for implementations of `Clone` for the moved type. If there is one, check if all its obligations are met. If they are, we suggest cloning without caveats. If they aren't, we suggest cloning while mentioning the unmet obligations, potentially suggesting `#[derive(Clone)]` when appropriate.
```
error[E0507]: cannot move out of a shared reference
--> $DIR/suggest-clone-when-some-obligation-is-unmet.rs:20:28
|
LL | let mut copy: Vec<U> = map.clone().into_values().collect();
| ^^^^^^^^^^^ ------------- value moved due to this method call
| |
| move occurs because value has type `HashMap<T, U, Hash128_1>`, which does not implement the `Copy` trait
|
note: `HashMap::<K, V, S>::into_values` takes ownership of the receiver `self`, which moves value
--> $SRC_DIR/std/src/collections/hash/map.rs:LL:COL
help: you could `clone` the value and consume it, if the `Hash128_1: Clone` trait bound could be satisfied
|
LL | let mut copy: Vec<U> = <HashMap<T, U, Hash128_1> as Clone>::clone(&map.clone()).into_values().collect();
| ++++++++++++++++++++++++++++++++++++++++++++ +
help: consider annotating `Hash128_1` with `#[derive(Clone)]`
|
LL + #[derive(Clone)]
LL | pub struct Hash128_1;
|
```
Fix#109429.
When encountering multiple mutable borrows, suggest cloning and adding
derive annotations as needed.
```
error[E0596]: cannot borrow `sm.x` as mutable, as it is behind a `&` reference
--> $DIR/accidentally-cloning-ref-borrow-error.rs:32:9
|
LL | foo(&mut sm.x);
| ^^^^^^^^^ `sm` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: `Str` doesn't implement `Clone`, so this call clones the reference `&Str`
--> $DIR/accidentally-cloning-ref-borrow-error.rs:31:21
|
LL | let mut sm = sr.clone();
| ^^^^^^^
help: consider annotating `Str` with `#[derive(Clone)]`
|
LL + #[derive(Clone)]
LL | struct Str {
|
help: consider specifying this binding's type
|
LL | let mut sm: &mut Str = sr.clone();
| ++++++++++
```
Fix#34629. Fix#76643. Fix#91532.
Instead of allowing `rustc::potential_query_instability` on the whole
crate we go over each lint and allow it individually if it is safe to
do. Turns out there were no instances of this lint in this crate.
Instead of allowing `rustc::potential_query_instability` on the whole
crate we go over each lint and allow it individually if it is safe to
do. Turns out all instances were safe to allow in this crate.
Instead of allowing `rustc::potential_query_instability` on the whole
crate we go over each lint and allow it individually if it is safe to
do. Turns out there were no instances of this lint in this crate.
Structured `use` suggestion on privacy error
When encoutering a privacy error on an item through a re-export that is accessible in an alternative path, provide a structured suggestion with that path.
```
error[E0603]: module import `mem` is private
--> $DIR/private-std-reexport-suggest-public.rs:4:14
|
LL | use foo::mem;
| ^^^ private module import
|
note: the module import `mem` is defined here...
--> $DIR/private-std-reexport-suggest-public.rs:8:9
|
LL | use std::mem;
| ^^^^^^^^
note: ...and refers to the module `mem` which is defined here
--> $SRC_DIR/std/src/lib.rs:LL:COL
|
= note: you could import this
help: import `mem` through the re-export
|
LL | use std::mem;
| ~~~~~~~~
```
Fix#42909.
Streamline MIR dataflow cursors
`rustc_mir_dataflow` has two kinds of results (`Results` and `ResultsCloned`) and three kinds of results cursor (`ResultsCursor`, `ResultsClonedCursor`, `ResultsRefCursor`). I found this quite confusing.
This PR removes `ResultsCloned`, `ResultsClonedCursor`, and `ResultsRefCursor`, leaving just `Results` and `ResultsCursor`. This makes the relevant code shorter and easier to read, and there is no performance penalty.
r? `@cjgillot`
When encoutering a privacy error on an item through a re-export that is
accessible in an alternative path, provide a structured suggestion with
that path.
```
error[E0603]: module import `mem` is private
--> $DIR/private-std-reexport-suggest-public.rs:4:14
|
LL | use foo::mem;
| ^^^ private module import
|
note: the module import `mem` is defined here...
--> $DIR/private-std-reexport-suggest-public.rs:8:9
|
LL | use std::mem;
| ^^^^^^^^
note: ...and refers to the module `mem` which is defined here
--> $SRC_DIR/std/src/lib.rs:LL:COL
|
= note: you could import this
help: import `mem` through the re-export
|
LL | use std::mem;
| ~~~~~~~~
```
Fix#42909.
When encountering multiple mutable borrows, suggest cloning and adding
derive annotations as needed.
```
error[E0596]: cannot borrow `sm.x` as mutable, as it is behind a `&` reference
--> $DIR/accidentally-cloning-ref-borrow-error.rs:32:9
|
LL | foo(&mut sm.x);
| ^^^^^^^^^ `sm` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: `Str` doesn't implement `Clone`, so this call clones the reference `&Str`
--> $DIR/accidentally-cloning-ref-borrow-error.rs:31:21
|
LL | let mut sm = sr.clone();
| ^^^^^^^
help: consider annotating `Str` with `#[derive(Clone)]`
|
LL + #[derive(Clone)]
LL | struct Str {
|
help: consider specifying this binding's type
|
LL | let mut sm: &mut Str = sr.clone();
| ++++++++++
```
```
error[E0596]: cannot borrow `*inner` as mutable, as it is behind a `&` reference
--> $DIR/issue-91206.rs:14:5
|
LL | inner.clear();
| ^^^^^ `inner` is a `&` reference, so the data it refers to cannot be borrowed as mutable
|
help: you can `clone` the `Vec<usize>` value and consume it, but this might not be your desired behavior
--> $DIR/issue-91206.rs:11:17
|
LL | let inner = client.get_inner_ref();
| ^^^^^^^^^^^^^^^^^^^^^^
help: consider specifying this binding's type
|
LL | let inner: &mut Vec<usize> = client.get_inner_ref();
| +++++++++++++++++
```
When encountering a case where `let x: T = (val: &T).clone();` and
`T: !Clone`, already mention that the reference is being cloned. We now
also suggest `#[derive(Clone)]` not only on `T` but also on type
parameters to satisfy blanket implementations.
```
error[E0308]: mismatched types
--> $DIR/assignment-of-clone-call-on-ref-due-to-missing-bound.rs:17:39
|
LL | let mut x: HashSet<Day> = v.clone();
| ------------ ^^^^^^^^^ expected `HashSet<Day>`, found `&HashSet<Day>`
| |
| expected due to this
|
= note: expected struct `HashSet<Day>`
found reference `&HashSet<Day>`
note: `HashSet<Day>` does not implement `Clone`, so `&HashSet<Day>` was cloned instead
--> $DIR/assignment-of-clone-call-on-ref-due-to-missing-bound.rs:17:39
|
LL | let mut x: HashSet<Day> = v.clone();
| ^
= help: `Clone` is not implemented because the trait bound `Day: Clone` is not satisfied
help: consider annotating `Day` with `#[derive(Clone)]`
|
LL + #[derive(Clone)]
LL | enum Day {
|
```
Case taken from # #41825.
When encountering a move error, look for implementations of `Clone` for
the moved type. If there is one, check if all its obligations are met.
If they are, we suggest cloning without caveats. If they aren't, we
suggest cloning while mentioning the unmet obligations, potentially
suggesting `#[derive(Clone)]` when appropriate.
```
error[E0507]: cannot move out of a shared reference
--> $DIR/suggest-clone-when-some-obligation-is-unmet.rs:20:28
|
LL | let mut copy: Vec<U> = map.clone().into_values().collect();
| ^^^^^^^^^^^ ------------- value moved due to this method call
| |
| move occurs because value has type `HashMap<T, U, Hash128_1>`, which does not implement the `Copy` trait
|
note: `HashMap::<K, V, S>::into_values` takes ownership of the receiver `self`, which moves value
--> $SRC_DIR/std/src/collections/hash/map.rs:LL:COL
help: you could `clone` the value and consume it, if the `Hash128_1: Clone` trait bound could be satisfied
|
LL | let mut copy: Vec<U> = <HashMap<T, U, Hash128_1> as Clone>::clone(&map.clone()).into_values().collect();
| ++++++++++++++++++++++++++++++++++++++++++++ +
help: consider annotating `Hash128_1` with `#[derive(Clone)]`
|
LL + #[derive(Clone)]
LL | pub struct Hash128_1;
|
```
Fix#109429.
When going through auto-deref, the `<T as Clone>` impl sometimes needs
to be specified for rustc to actually clone the value and not the
reference.
```
error[E0507]: cannot move out of dereference of `S`
--> $DIR/needs-clone-through-deref.rs:15:18
|
LL | for _ in self.clone().into_iter() {}
| ^^^^^^^^^^^^ ----------- value moved due to this method call
| |
| move occurs because value has type `Vec<usize>`, which does not implement the `Copy` trait
|
note: `into_iter` takes ownership of the receiver `self`, which moves value
--> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
help: you can `clone` the value and consume it, but this might not be your desired behavior
|
LL | for _ in <Vec<usize> as Clone>::clone(&self.clone()).into_iter() {}
| ++++++++++++++++++++++++++++++ +
```
CC #109429.
rustc: Harmonize `DefKind` and `DefPathData`
Follow up to https://github.com/rust-lang/rust/pull/118188.
`DefPathData::(ClosureExpr,ImplTrait)` are renamed to match `DefKind::(Closure,OpaqueTy)`.
`DefPathData::ImplTraitAssocTy` is replaced with `DefPathData::TypeNS(kw::Empty)` because both correspond to `DefKind::AssocTy`.
It's possible that introducing `(DefKind,DefPathData)::AssocOpaqueTy` instead could be a better solution, but that would be a much more invasive change.
Const generic parameters introduced for effects are moved from `DefPathData::TypeNS` to `DefPathData::ValueNS`, because constants are values.
`DefPathData` is no longer passed to `create_def` functions to avoid redundancy.
more targeted errors when extern types end up in places they should not
Cc https://github.com/rust-lang/rust/issues/115709 -- this does not fix that bug but it makes the panics less obscure and makes it more clear that this is a deeper issue than just a little codegen oversight. (In https://github.com/rust-lang/rust/pull/116115 we decided we'd stick to causing ICEs here for now, rather than nicer errors. We can't currently show any errors pre-mono and probably we don't want post-mono checks when this gets stabilized anyway.)
Restrict what symbols can be used in `#[diagnostic::on_unimplemented]` format strings
This commit restricts what symbols can be used in a format string for any option of the `diagnostic::on_unimplemented` attribute. We previously allowed all the ad-hoc options supported by the internal `#[rustc_on_unimplemented]` attribute. For the stable attribute we only want to support generic parameter names and `{Self}` as parameters. For any other parameter an warning is emitted and the parameter is replaced by the literal parameter string, so for example `{integer}` turns into `{integer}`. This follows the general design of attributes in the `#[diagnostic]` attribute namespace, that any syntax "error" is treated as warning and subsequently ignored.
r? `@compiler-errors`
This commit restricts what symbols can be used in a format string for
any option of the `diagnostic::on_unimplemented` attribute. We
previously allowed all the ad-hoc options supported by the internal
`#[rustc_on_unimplemented]` attribute. For the stable attribute we only
want to support generic parameter names and `{Self}` as parameters. For
any other parameter an warning is emitted and the parameter is replaced
by the literal parameter string, so for example `{integer}` turns into
`{integer}`. This follows the general design of attributes in the
`#[diagnostic]` attribute namespace, that any syntax "error" is treated
as warning and subsequently ignored.
This is weird: `HandlerInner::emit` calls
`HandlerInner::emit_diagnostic`, but only after doing a
`treat-err-as-bug` check. Which is fine, *except* that there are
multiple others paths for an `Error` or `Fatal` diagnostic to be passed
to `HandlerInner::emit_diagnostic` without going through
`HandlerInner::emit`, e.g. `Handler::span_err` call
`Handler::emit_diag_at_span`, which calls `emit_diagnostic`.
So that suggests that the coverage for `treat-err-as-bug` is incomplete.
This commit removes `HandlerInner::emit` and moves the
`treat-err-as-bug` check to `HandlerInner::emit_diagnostic`, so it
cannot by bypassed.
`Handler` is a wrapper around `HanderInner`. Some functions on
on `Handler` just forward to the samed-named functions on
`HandlerInner`.
This commit removes as many of those as possible, implementing functions
on `Handler` where possible, to avoid the boilerplate required for
forwarding. The commit is moderately large but it's very mechanical.
These impls are all needed for just a single `IntoDiagnostic` type, not
a family of them.
Note that `ErrorGuaranteed` is the default type parameter for
`IntoDiagnostic`.
Exhaustiveness: allocate memory better
Exhaustiveness is a recursive algorithm that allocates a bunch of slices at every step. Let's see if I can improve performance by improving allocations.
Already just using `Vec::with_capacity` is showing impressive improvements on my local measurements.
r? `@ghost`
Currently, `Handler::fatal` returns `FatalError`. But `Session::fatal`
returns `!`, because it calls `Handler::fatal` and then calls `raise` on
the result. This inconsistency is unfortunate.
This commit changes `Handler::fatal` to do the `raise` itself, changing
its return type to `!`. This is safe because there are only two calls to
`Handler::fatal`, one in `rustc_session` and one in
`rustc_codegen_cranelift`, and they both call `raise` on the result.
`HandlerInner::fatal` still returns `FatalError`, so I renamed it
`fatal_no_raise` to emphasise the return type difference.
miri: support 'promising' alignment for symbolic alignment check
Then use that ability in `slice::align_to`, so that even with `-Zmiri-symbolic-alignment-check`, it no longer has to return spuriously empty "middle" parts.
Fixes https://github.com/rust-lang/miri/issues/3068
Rollup of 3 pull requests
Successful merges:
- #117869 ([rustdoc] Add highlighting for comments in items declaration)
- #118525 (coverage: Skip spans that can't be un-expanded back to the function body)
- #118574 (rustc_session: Address all `rustc::potential_query_instability` lints)
r? `@ghost`
`@rustbot` modify labels: rollup
rustc_session: Address all `rustc::potential_query_instability` lints
Instead of allowing `rustc::potential_query_instability` on the whole crate we go over each lint and allow it individually if it is safe to do. Turns out all instances were safe to allow in this crate.
Part of #84447 which is **E-help-wanted**.
coverage: Skip spans that can't be un-expanded back to the function body
When we extract coverage spans from MIR, we try to "un-expand" them back to spans that are inside the function's body span.
In cases where that doesn't succeed, the current code just swaps in the entire body span instead. But that tends to result in coverage spans that are completely unrelated to the control flow of the affected code, so it's better to just discard those spans.
---
Extracted from #118305, since this is a general improvement that isn't specific to branch coverage.
---
`@rustbot` label +A-code-coverage
Provide structured suggestion for type mismatch in loop
We currently provide only a `help` message, this PR introduces the last two structured suggestions instead:
```
error[E0308]: mismatched types
--> $DIR/issue-98982.rs:2:5
|
LL | fn foo() -> i32 {
| --- expected `i32` because of return type
LL | / for i in 0..0 {
LL | | return i;
LL | | }
| |_____^ expected `i32`, found `()`
|
note: the function expects a value to always be returned, but loops might run zero times
--> $DIR/issue-98982.rs:2:5
|
LL | for i in 0..0 {
| ^^^^^^^^^^^^^ this might have zero elements to iterate on
LL | return i;
| -------- if the loop doesn't execute, this value would never get returned
help: return a value for the case when the loop has zero elements to iterate on
|
LL ~ }
LL ~ /* `i32` value */
|
help: otherwise consider changing the return type to account for that possibility
|
LL ~ fn foo() -> Option<i32> {
LL | for i in 0..0 {
LL ~ return Some(i);
LL ~ }
LL ~ None
|
```
Fix#98982.
Report errors in jobserver inherited through environment variables
This pr attempts to catch situations, when jobserver exists, but is not being inherited.
r? `@petrochenkov`
Instead of allowing `rustc::potential_query_instability` on the whole
crate we go over each lint and allow it individually if it is safe to
do. Turns out all instances were safe to allow in this crate.
`DefPathData::(ClosureExpr,ImplTrait)` are renamed to match `DefKind::(Closure,OpaqueTy)`.
`DefPathData::ImplTraitAssocTy` is replaced with `DefPathData::TypeNS(kw::Empty)` because both correspond to `DefKind::AssocTy`.
It's possible that introducing `(DefKind,DefPathData)::AssocOpaqueTy` could be a better solution, but that would be a much more invasive change.
Const generic parameters introduced for effects are moved from `DefPathData::TypeNS` to `DefPathData::ValueNS`, because constants are values.
`DefPathData` is no longer passed to `create_def` functions to avoid redundancy.
Because a macro invocation can expand to a never pattern, we can't rule
out a `arm!(),` arm at parse time. Instead we detect that case at
expansion time, if the macro tries to output a pattern followed by `=>`.
When we extract coverage spans from MIR, we try to "un-expand" them back to
spans that are inside the function's body span.
In cases where that doesn't succeed, the current code just swaps in the entire
body span instead. But that tends to result in coverage spans that are
completely unrelated to the control flow of the affected code, so it's better
to just discard those spans.
Add more information to StableMIR Instance
Allow stable MIR users to retrieve an instance function signature, the index for a VTable instance and more information about its underlying definition.
These are needed to properly interpret function calls, either via VTable or direct calls. The `CrateDef` implementation will also allow users to emit diagnostic messages.
I also fixed a few issues that we had identified before with how we were retrieving body of things that may not have a body available.
Handle recursion limit for subtype and well-formed predicates
Adds a recursion limit check for subtype predicates and well-formed predicates.
`-Ztrait-solver=next` currently panics with unimplemented for these cases.
These cases are arguably bugs in the occurs check but:
- I could not find a simple way to fix the occurs check
- There should still be a recursion limit check to prevent hangs anyway.
closes#117151
r? types
Centralize live loans maintenance to fix scope differences due to liveness
As found in the recent [polonius crater run](https://github.com/rust-lang/rust/pull/117593#issuecomment-1801398892), NLLs and the location-insensitive polonius computed different scopes on some specific CFG shapes, e.g. the following.
I had missed that liveness data was pushed from different sources than just the liveness computation: there are a few places that do this -- and some of them may be unneeded or at the very least untested, as no tests changed when I tried removing some of them.
Here, `_6` is e.g. dead on entry to `bb2[0]` during `liveness::trace`, but its regions will be marked as live later during "constraint generation" (which I plan to refactor away and put in the liveness module soon). This should cause the inflowing loans to be marked live, but they were only computed in `liveness::trace`.
Therefore, this PR moves live loan maintenance to `LivenessValues`, so that the various places pushing liveness data will all also update live loans at the same time -- except for promoteds which I don't believe need them, and their liveness handling is already interesting/peculiar.
All the regressions I saw in the initial crater run were related to this kind of shapes, and this change did fix all of them on the [next run](https://github.com/rust-lang/rust/pull/117593#issuecomment-1826132145).
r? `@matthewjasper`
(This will conflict with #117880 but whichever lands first is fine by me, the end goal is the same for both)
Restore `#![no_builtins]` crates participation in LTO.
After #113716, we can make `#![no_builtins]` crates participate in LTO again.
`#![no_builtins]` with LTO does not result in undefined references to the error. I believe this type of issue won't happen again.
Fixes#72140. Fixes#112245. Fixes#110606. Fixes#105734. Fixes#96486. Fixes#108853. Fixes#108893. Fixes#78744. Fixes#91158. Fixes https://github.com/rust-lang/cargo/issues/10118. Fixes https://github.com/rust-lang/compiler-builtins/issues/347.
The `nightly-2023-07-20` version does not always reproduce problems due to changes in compiler-builtins, core, and user code. That's why this issue recurs and disappears.
Some issues were not tested due to the difficulty of reproducing them.
r? pnkfelix
cc `@bjorn3` `@japaric` `@alexcrichton` `@Amanieu`
Liveness data is pushed from multiple parts of NLL. Instead of changing
the call sites to maintain live loans, move the latter to `LivenessValues` where
this liveness data is pushed to, and maintain live loans there.
This fixes the differences in polonius scopes on some CFGs where a
variable was dead in tracing but as a MIR terminator its regions were marked
live from "constraint generation"
Stabilize C string literals
RFC: https://rust-lang.github.io/rfcs/3348-c-str-literal.html
Tracking issue: https://github.com/rust-lang/rust/issues/105723
Documentation PR (reference manual): https://github.com/rust-lang/reference/pull/1423
# Stabilization report
Stabilizes C string and raw C string literals (`c"..."` and `cr#"..."#`), which are expressions of type [`&CStr`](https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html). Both new literals require Rust edition 2021 or later.
```rust
const HELLO: &core::ffi::CStr = c"Hello, world!";
```
C strings may contain any byte other than `NUL` (`b'\x00'`), and their in-memory representation is guaranteed to end with `NUL`.
## Implementation
Originally implemented by PR https://github.com/rust-lang/rust/pull/108801, which was reverted due to unintentional changes to lexer behavior in Rust editions < 2021.
The current implementation landed in PR https://github.com/rust-lang/rust/pull/113476, which restricts C string literals to Rust edition >= 2021.
## Resolutions to open questions from the RFC
* Adding C character literals (`c'.'`) of type `c_char` is not part of this feature.
* Support for `c"..."` literals does not prevent `c'.'` literals from being added in the future.
* C string literals should not be blocked on making `&CStr` a thin pointer.
* It's possible to declare constant expressions of type `&'static CStr` in stable Rust (as of v1.59), so C string literals are not adding additional coupling on the internal representation of `CStr`.
* The unstable `concat_bytes!` macro should not accept `c"..."` literals.
* C strings have two equally valid `&[u8]` representations (with or without terminal `NUL`), so allowing them to be used in `concat_bytes!` would be ambiguous.
* Adding a type to represent C strings containing valid UTF-8 is not part of this feature.
* Support for a hypothetical `&Utf8CStr` may be explored in the future, should such a type be added to Rust.
Refactor NLL constraint generation and most of polonius fact generation
As discussed in #118175, NLL "constraint generation" is only about liveness, but currently also contains legacy polonius fact generation. The latter is quite messy, and this PR cleans this up to prepare for its future removal:
- splits polonius fact generation out of NLL constraint generation
- merges NLL constraint generation to its more natural place, liveness
- extracts all of the polonius fact generation from NLLs apart from MIR typeck (as fact generation is somewhat in a single place there already, but should be cleaned up) into its own explicit module, with a single entry point instead of many.
There should be no behavior changes, and tests seem to behave the same as master: without polonius, with legacy polonius, with the in-tree polonius.
I've split everything into smaller logical commits for easier review, as it required quite a bit of code to be split and moved around, but it should all be trivial changes.
r? `@matthewjasper`
Rollup of 3 pull requests
Successful merges:
- #118483 (rustdoc: `div.where` instead of fmt-newline class)
- #118486 (generic_const_exprs: suggest to add the feature, not use it)
- #118489 (Wesley is on vacation)
r? `@ghost`
`@rustbot` modify labels: rollup
generic_const_exprs: suggest to add the feature, not use it
Usually our missing feature messages look something like
```
= help: add `#![feature(inline_const)]` to the crate attributes to enable
```
However `generic_const_exprs` used a different verb. That's inconsistent and it also means playground won't add that nice hyperlink to add the feature automatically. So let's use the same verb as everywhere else.
explain a good reason for why LocalValue does not store the type of the local
As found out by `@lcnr` in https://github.com/rust-lang/rust/pull/112307, storing the type here can lead to subtle bugs when it gets out of sync with the MIR body. That's not the reason why the interpreter does it this way I think, but good thing we dodged that bullet. :)
Change `SwitchTarget` representation in StableMIR
The new structure encodes its invariant, which reduces the likelihood of having an inconsistent representation. It is also more intuitive and user friendly.
I encapsulated the structure for now in case we decide to change it back.
### Notes:
1. I had to change the `Successors` type, since there's a conflict on the iterator type. We could potentially implement an iterator here, but I would prefer keeping it simple for now, and add a `successors_iter()` method if needed.
2. I removed `CoroutineDrop` for now since it we never create it. We can add it when we add support to other MIR stages.
Add `-Zfunction-return={keep,thunk-extern}` option
This is intended to be used for Linux kernel RETHUNK builds.
With this commit (optionally backported to Rust 1.73.0), plus a patched Linux kernel to pass the flag, I get a RETHUNK build with Rust enabled that is `objtool`-warning-free and is able to boot in QEMU and load a sample Rust kernel module.
Issue: https://github.com/rust-lang/rust/issues/116853.
On Fn arg mismatch for a fn path, suggest a closure
When encountering a fn call that has a path to another fn being passed in, where an `Fn` impl is expected, and the arguments differ, suggest wrapping the argument with a closure with the appropriate arguments.
The last `help` is new:
```
error[E0631]: type mismatch in function arguments
--> $DIR/E0631.rs:9:9
|
LL | fn f(_: u64) {}
| ------------ found signature defined here
...
LL | foo(f);
| --- ^ expected due to this
| |
| required by a bound introduced by this call
|
= note: expected function signature `fn(usize) -> _`
found function signature `fn(u64) -> _`
note: required by a bound in `foo`
--> $DIR/E0631.rs:3:11
|
LL | fn foo<F: Fn(usize)>(_: F) {}
| ^^^^^^^^^ required by this bound in `foo`
help: consider wrapping the function in a closure
|
LL | foo(|arg0: usize| f(/* u64 */));
| +++++++++++++ +++++++++++
```
The new structure encodes its invariant, which reduces the likelihood
of having an inconsistent representation. It is also more intuitive and
user friendly.
I encapsulated the structure for now in case we decide to change it back.
This is intended to be used for Linux kernel RETHUNK builds.
With this commit (optionally backported to Rust 1.73.0), plus a
patched Linux kernel to pass the flag, I get a RETHUNK build with
Rust enabled that is `objtool`-warning-free and is able to boot in
QEMU and load a sample Rust kernel module.
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Dispose llvm::TargetMachines prior to llvm::Context being disposed
If the TargetMachine is disposed after the Context is disposed, it can lead to use after frees in some cases.
I've observed this happening occasionally on code compiled for aarch64-pc-windows-msvc using `-Zstack-protector=strong` but other users have reported AVs from host aarch64-pc-windows-msvc compilers as well.
I was not able to extract a self-contained test case yet so there is no accompanying test.
Fixes#118462
rustc_span: Remove unused symbols.
As noted here, there is no guarantee that all pre-interned symbols are used.
b10cfcd65f/compiler/rustc_span/src/symbol.rs (L124-L125)
This was done starting with using ripgrep to search for `sym::whatever`. I removed anything that didn't show up. However this had a huge number of false positives, due to extensive macro use. Then there was a manual phase of adding back all the ones used my macros.
I don't think this was worth my time to do, but it's done now . ¯\_(ツ)_/¯
Tweak message on ADT with private fields building
When trying to create an inaccessible ADT due to private fields, handle the case when no fields were passed.
```
error: cannot construct `Foo` with struct literal syntax due to private fields
--> $DIR/issue-76077.rs:8:5
|
LL | foo::Foo {};
| ^^^^^^^^
|
= note: private field `you_cant_use_this_field` that was not provided
```
miri: add test checking that aggregate assignments reset memory to uninit
Also, `write_aggregate` is really just a helper for evaluating `Aggregate` rvalues, so it should be in `step.rs`, not `place.rs`. Also factor out `Repeat` rvalues into their own function while we are at it.
r? `@saethlin`
Fixes https://github.com/rust-lang/miri/issues/3195
They're not used in `rustc_session`, and `rustc_metadata` is a more
obvious location.
`MetadataLoader` was originally put into `rustc_session` in #41565 to
avoid a dependency on LLVM, but things have changed a lot since then and
that's no longer relevant, e.g. `rustc_codegen_llvm` depends on
`rustc_metadata`.
Fix `PartialEq` args when `#[const_trait]` is enabled
This is based off of your PR that enforces effects on all methods, so just see the last commits.
r? fee1-dead
Tweak parsing recovery of enums, for exprs and match arm patterns
Tweak recovery of `for (pat in expr) {}` for more accurate spans.
When encountering `match` arm `(pat if expr) => {}`, recover and suggest removing parentheses. Fix#100825.
When encountering malformed enums, try more localized per-variant parse recovery.
Move parser recovery tests to subdirectory.
If the TargetMachine is disposed after the Context is disposed, it can
lead to use after frees in some cases.
I've observed this happening occasionally on code compiled for
aarch64-pc-windows-msvc using `-Zstack-protector=strong` but other users
have reported AVs from host aarch64-pc-windows-msvc compilers as well.
Pass +forced-atomics feature for riscv32{i,im,imc}-unknown-none-elf
As said in https://github.com/rust-lang/rust/pull/98333#issuecomment-1666375293, `forced-atomics` target feature is also needed to enable atomic load/store on these targets (otherwise, libcalls are generated): https://godbolt.org/z/433qeG7vd
~~This PR is currently marked as a draft because:~~
- ~~`forced-atomics` target feature is currently broken (https://github.com/rust-lang/rust/issues/114153).~~ EDIT: Fixed
- ~~`forced-atomics` target feature has been added in LLVM 16 (f5ed0cb217), but the current minimum LLVM version [is 15](90f0b24ad3/src/bootstrap/llvm.rs (L557)). In LLVM 15, the atomic load/store of these targets generates libcalls anyway.~~ EDIT: LLVM 15 has been dropped
Depending on the policy on the minimum LLVM version for these targets, this may be blocked until the minimum LLVM version is increased to 16.
r? `@Amanieu`
When encountering a fn call that has a path to another fn being passed
in, where an `Fn` impl is expected, and the arguments differ, suggest
wrapping the argument with a closure with the appropriate arguments.
When trying to create an inaccessible ADT due to private fields, handle
the case when no fields were passed.
```
error: cannot construct `Foo` with struct literal syntax due to private fields
--> $DIR/issue-76077.rs:8:5
|
LL | foo::Foo {};
| ^^^^^^^^
|
= note: private field `you_cant_use_this_field` that was not provided
```
ConstProp: Correctly remove const if unknown value assigned to it.
Closes#118328
The problematic sequence of MIR is:
```rust
_1 = const 0_usize;
_1 = const _; // This is an associated constant we can't know before monomorphization.
_0 = _1;
```
1. When `ConstProp::visit_assign` happens on `_1 = const 0_usize;`, it records that `0x0usize` is the value for `_1`.
2. Next `visit_assign` happens on `_1 = const _;`. Because the rvalue `.has_param()`, it can't be const evaled.
3. Finaly, `visit_assign` happens on `_0 = _1;`. Here it would think the value of `_1` was `0x0usize` from step 1.
The solution is to remove consts when checking the RValue fails, as they may have contained values that should now be invalidated, as that local was overwritten.
This should probably be back-ported to beta. Stable is more iffy, as it's gone unidentified since 1.70, so I only think it's worthwhile if there's another reason for a 1.74.1 release anyway.
Suggest `let` or `==` on typo'd let-chain
When encountering a bare assignment in a let-chain, suggest turning the
assignment into a `let` expression or an equality check.
```
error: expected expression, found `let` statement
--> $DIR/bad-if-let-suggestion.rs:5:8
|
LL | if let x = 1 && i = 2 {}
| ^^^^^^^^^
|
= note: only supported directly in conditions of `if` and `while` expressions
help: you might have meant to continue the let-chain
|
LL | if let x = 1 && let i = 2 {}
| +++
help: you might have meant to compare for equality
|
LL | if let x = 1 && i == 2 {}
| +
```
Add `never_patterns` feature gate
This PR adds the feature gate and most basic parsing for the experimental `never_patterns` feature. See the tracking issue (https://github.com/rust-lang/rust/issues/118155) for details on the experiment.
`@scottmcm` has agreed to be my lang-team liaison for this experiment.
Rollup of 7 pull requests
Successful merges:
- #118342 (Dont suggest `!` for path in function call if it has generic args)
- #118383 (Address unused tuple struct fields in the standard library)
- #118401 (`rustc_ast_lowering` cleanups)
- #118409 (format_foreign.rs: unwrap return Option value for `fn position`, as it always returns Some)
- #118413 (Fix the issue of suggesting unwrap/expect for shorthand field)
- #118425 (Update cargo)
- #118429 (Fix a typo in a `format_args!` note)
r? `@ghost`
`@rustbot` modify labels: rollup
format_foreign.rs: unwrap return Option value for `fn position`, as it always returns Some
Trivial cleanup.
It will be nice to have way to run exhaustiveness analysis on similar cases to see dead code.
Fix coroutine validation for mixed panic strategy
Validation introduced in #113124 allows `UnwindAction::Continue` and `TerminatorKind::Resume` to occur only in functions with ABI that can unwind. The function ABI depends on the panic strategy, which can vary across crates.
Usually MIR is built and validated in the same crate. The coroutine drop glue thus far was an exception. As a result validation could fail when mixing different panic strategies.
Avoid the problem by executing `AbortUnwindingCalls` along with the validation.
Fixes#116953.
Eagerly return `ExprKind::Err` on `yield`/`await` in wrong coroutine context
This PR does 2 things:
1. Refuses to lower `.await` or `yield` when we are outside of the right coroutine context for the operator. Instead, we lower to `hir::ExprKind::Err`, to silence subsequent redundant errors.
2. Reworks a bit of the span tracking in `LoweringContext` to fix a bad span when we have something like `let x = [0; async_fn().await]` where the `await` is inside of an anon const. The span for the "item" still kinda sucks, since it overlaps with the `await` span, but at least it's accurate.
Remove HIR opkinds
`hir::BinOp`, `hir::BinOpKind`, and `hir::UnOp` are identical to `ast::BinOp`, `ast::BinOpKind`, and `ast::UnOp`, respectively. This seems silly, so this PR removes the HIR ones. (A re-export lets the AST ones be referred to using a `hir::` qualifier, which avoids renaming churn.)
r? `@cjgillot`
Unify `TraitRefs` and `PolyTraitRefs` in `ValuePairs`
I did this recently with `FnSigs` and `PolyFnSigs` but didn't think to do it with `TraitRefs` and `PolyTraitRefs`.
Cut code size for feature hashing
This locally cuts ~32 kB of .text instructions.
This isn't really a clear win in terms of readability. IMO the code size benefits are worth it (even if they're not necessarily present in the x86_64 hyperoptimized build, I expect them to translate similarly to other platforms). Ultimately there's lots of "small ish" low hanging fruit like this that I'm seeing that seems worth tackling to me, and could translate into larger wins in aggregate.
Rollup of 6 pull requests
Successful merges:
- #118193 (Add missing period in `std::process::Command` docs)
- #118222 (unify read_to_end and io::copy impls for reading into a Vec)
- #118323 (give dev-friendly error message for incorrect config profiles)
- #118378 (Perform LTO optimisations with wasm-ld + -Clinker-plugin-lto)
- #118399 (Clean dead codes in miri)
- #118410 (update test for new LLVM 18 codegen)
r? `@ghost`
`@rustbot` modify labels: rollup
Validation introduced in #113124 allows UnwindAction::Continue and
TerminatorKind::Resume to occur only in functions with ABI that can
unwind. The function ABI depends on the panic strategy, which can vary
across crates.
Usually MIR is built and validated in the same crate. The coroutine drop
glue thus far was an exception. As a result validation could fail when
mixing different panic strategies.
Avoid the problem by executing AbortUnwindingCalls along with the
validation.
When encountering a bare assignment in a let-chain, suggest turning the
assignment into a `let` expression or an equality check.
```
error: expected expression, found `let` statement
--> $DIR/bad-if-let-suggestion.rs:5:8
|
LL | if let x = 1 && i = 2 {}
| ^^^^^^^^^
|
= note: only supported directly in conditions of `if` and `while` expressions
help: you might have meant to continue the let-chain
|
LL | if let x = 1 && let i = 2 {}
| +++
help: you might have meant to compare for equality
|
LL | if let x = 1 && i == 2 {}
| +
```
Perform LTO optimisations with wasm-ld + -Clinker-plugin-lto
Fixes (partially) #60059. Technically, `--target wasm32-unknown-unknown -Clinker-plugin-lto` would complete without errors before, but it was not producing optimized code. At least, it may have been but it was probably not the opt-level people intended.
Similarly to #118377, this could benefit from a warning about using an explicit libLTO path with LLD, which will ignore it and use its internal LLVM. Especially given we always use lld on wasm targets. I left the code open to that possibility rather than making it perfectly neat.
effects: Run `enforce_context_effects` for all method calls
So that we also perform checks when overloaded `PartialEq`s are called.
r? `@compiler-errors`
They're identical to the same-named types from `ast`. I find it silly
(and inefficient) to have all this boilerplate code to convert one type
to an identical type.
There is already a small amount of type sharing between the AST and HIR,
e.g. `Attribute`, `MacroDef`.
The commit adds a `pub use` to `rustc_hir` so that, for example,
`ast::BinOp` can also be referred to as `hir::BinOp`. This is so the
many existing `hir`-qualified mentions of these types don't need to
change.
The commit also moves a couple of operations from the (removed) HIR
types to the AST types, e.g. `is_by_value`.
rustc_span: Use correct edit distance start length for suggestions
Otherwise the suggestions can be off-base for non-ASCII identifiers. For example suggesting that `Ok` is a name similar to `读文`.
Closes https://github.com/rust-lang/rust/issues/72553.
QueryContext: rename try_collect_active_jobs -> collect_active_jobs, change return type from Option<QueryMap> to QueryMap
As there currently always Some(...) inside.
Added linker_arg(s) Linker trait methods for link-arg to be prefixed "-Wl," for cc-like linker args and not verbatim
https://github.com/rust-lang/rust/issues/99427#issuecomment-1234443468
> here's one possible improvement to -l link-arg making it more portable between linkers and useful - befriending it with the verbatim modifier (https://github.com/rust-lang/rust/issues/99425).
>
> -l link-arg:-verbatim=-foo would add -Wl,-foo (or equivalent) when C compiler is used as a linker, and just -foo when bare linker is used.
> -l link-arg:+verbatim=-bar on the other hand would always pass just -bar.
Add `pretty_terminator` to pretty stable-mir
~Because we don't have successors in `stable_mir` this is somewhat lacking but it's better than nothing~, also fixed bug(?) with `Opaque` which printed extra `"` when we try to print opaqued `String`.
**Edit**: Added successors so this covers Terminators as a whole.
r? `@celinval`
Account for `!` arm in tail `match` expr
On functions with a default return type that influences the coerced type of `match` arms, check if the failing arm is actually of type `!`. If so, suggest changing the return type so the coercion against the prior arms is successful.
```
error[E0308]: `match` arms have incompatible types
--> $DIR/match-tail-expr-never-type-error.rs:9:13
|
LL | fn bar(a: bool) {
| - help: try adding a return type: `-> i32`
LL | / match a {
LL | | true => 1,
| | - this is found to be of type `{integer}`
LL | | false => {
LL | | never()
| | ^^^^^^^
| | |
| | expected integer, found `()`
| | this expression is of type `!`, but it get's coerced to `()` due to its surrounding expression
LL | | }
LL | | }
| |_____- `match` arms have incompatible types
```
Fix#24157.
- Rename them both `as_str`, which is the typical name for a function
that returns a `&str`. (`to_string` is appropriate for functions
returning `String` or maybe `Cow<'a, str>`.)
- Change `UnOp::as_str` from an associated function (weird!) to a
method.
- Avoid needless `self` dereferences.
Do not erase late bound regions when selecting inherent associated types
In the fix for #97156 we would want the following code:
```rust
#![feature(inherent_associated_types)]
#![allow(incomplete_features)]
struct Foo<T>(T);
impl Foo<fn(&'static ())> {
type Assoc = u32;
}
trait Other {}
impl Other for u32 {}
// FIXME(inherent_associated_types): Avoid emitting two diagnostics (they only differ in span).
// FIXME(inherent_associated_types): Enhancement: Spruce up the diagnostic by saying something like
// "implementation is not general enough" as is done for traits via
// `try_report_trait_placeholder_mismatch`.
fn bar(_: Foo<for<'a> fn(&'a ())>::Assoc) {}
//~^ ERROR mismatched types
//~| ERROR mismatched types
fn main() {}
```
to fail with ...
```
error[E0220]: associated type `Assoc` not found for `Foo<for<'a> fn(&'a ())>` in the current scope
--> tests/ui/associated-inherent-types/issue-109789.rs:18:36
|
4 | struct Foo<T>(T);
| ------------- associated item `Assoc` not found for this struct
...
18 | fn bar(_: Foo<for<'a> fn(&'a ())>::Assoc) {}
| ^^^^^ associated item not found in `Foo<for<'a> fn(&'a ())>`
|
= note: the associated type was found for
- `Foo<fn(&'static ())>`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0220`.
```
This PR fixes the ICE we are currently getting "was a subtype of Foo<Binder(fn(&ReStatic ()), [])> during selection but now it is not"
Also fixes#112631
r? `@lcnr`
On functions with a default return type that influences the coerced type
of `match` arms, check if the failing arm is actually of type `!`. If
so, suggest changing the return type so the coercion against the prior
arms is successful.
```
error[E0308]: `match` arms have incompatible types
--> $DIR/match-tail-expr-never-type-error.rs:9:13
|
LL | fn bar(a: bool) {
| - help: try adding a return type: `-> i32`
LL | / match a {
LL | | true => 1,
| | - this is found to be of type `{integer}`
LL | | false => {
LL | | never()
| | ^^^^^^^
| | |
| | expected integer, found `()`
| | this expression is of type `!`, but it get's coerced to `()` due to its surrounding expression
LL | | }
LL | | }
| |_____- `match` arms have incompatible types
```
Fix#24157.
Suggest swapping the order of `ref` and `box`
It is not valid grammar to write `ref box <ident>` in patterns, but `box ref <ident>` is.
This patch adds a diagnostic to suggest swapping them, analogous to what we do for `mut let`.
Enable the Arm Cortex-A53 errata mitigation on aarch64-unknown-none
Arm Cortex-A53 CPUs have an errata related to a specific sequence of instructions - errata number 843419 (https://documentation-service.arm.com/static/5fa29fddb209f547eebd361d). There is a mitigation that can be applied at link-time which detects the when sequence of instructions exists at a specific alignment. When detected, the linker re-writes those instructions and either changes an ADRP to an ADR, or bounces to a veneer to break the sequence.
The linker argument to enable the mitigation is "--fix-cortex-a53-843419", and this is supported by GNU ld and LLVM lld. The gcc argument to enable the flag is "-mfix-cortex-a53-843419".
Because the aarch64-unknown-none target uses rust-lld directly, this patch causes rustc to emit the "--fix-cortex-a53-843419" argument when calling the linker, just like aarch64-linux-gnu-gcc on Ubuntu 22.04 does.
Failure to enable this mitigation in the linker can cause the production of instruction sequences that do not execute correctly on Arm Cortex-A53.
Eagerly compute output_filenames
It can be computed before creating TyCtxt. Previously the query would also write the dep info file, which meant that the output filenames couldn't be accessed before macro expansion is done. The dep info file writing is now done as a separate non-query function. The old query was always executed again anyways due to depending on the HIR.
Also encode the output_filenames in rlink files to ensure `#![crate_name]` affects the linking stage when doing separate compiling and linking using `-Zno-link`/`-Zlink-only`.
They both now only ever contain a `Results<'tcx, A>`.
This means `AnalysisResults` can be removed, as can many
`borrow`/`borrow_mut` calls. Also `Results` no longer needs a
`PhantomData` because `'tcx` is now named by `entry_sets`.
By just cloning the entire `Results` in the one place where
`ResultsClonedCursor` was used. This is extra allocations but the
performance effect is negligible.
It's currently used because `requires_storage_results` is used in two
locations: once with a cursor, and once later on without a cursor. The
non-consuming `as_results_cursor` is used for the first location.
But we can instead use the consuming `into_results_cursor` and then use
`into_results` to extract the `Results` from the finished-with cursor
for use at the second location.
It's only implemented for analyses that implement `Copy`, which means
it's basically a complicated synonym for `Copy`. So this commit removes
it and uses `Copy` directly. (That direct use will be removed in a later
commit.)
Call FileEncoder::finish in rmeta encoding
Fixes https://github.com/rust-lang/rust/issues/117254
The bug here was that rmeta encoding never called FileEncoder::finish. Now it does. Most of the changes here are needed to support that, since rmeta encoding wants to finish _then_ access the File in the encoder, so finish can't move out.
I tried adding a `cfg(debug_assertions)` exploding Drop impl to FileEncoder that checked for finish being called before dropping, but fatal errors cause unwinding so this isn't really possible. If we encounter a fatal error with a dirty FileEncoder, the Drop impl ICEs even though the implementation is correct. If we try to paper over that by wrapping FileEncoder in ManuallyDrop then that just erases the fact that Drop automatically checks that we call finish on all paths.
I also changed the name of DepGraph::encode to DepGraph::finish_encoding, because that's what it does and it makes the fact that it is the path to FileEncoder::finish less confusing.
r? `@WaffleLapkin`
`AmbiguityCause` should not eagerly format strings
Minor tweak found when working on some coherence diagnostics stuff (towards `-Ztrait-solver=next-coherence` stabilization)
to help review, this duplicates the existing NLL + polonius constraint
generation component, before splitting them up to only do what they
individually need.
Refactor borrowck liveness values
This PR starts cleaning up `rustc_borrowck`, in particular around liveness values:
- refactors simple names that make no sense anymore: either referring to older structures using region elements, or to bitset containers and values.
- improves comments and fixes others
- removes unused return values and unneeded generic arguments
r? `@matthewjasper`
Rewrite exhaustiveness in one pass
This is at least my 4th attempt at this in as many years x) Previous attempts were all too complicated or too slow. But we're finally here!
The previous version of the exhaustiveness algorithm computed reachability for each arm then exhaustiveness of the whole match. Since each of these steps does roughly the same things, this rewrites the algorithm to do them all in one go. I also think this makes things much simpler.
I also rewrote the documentation of the algorithm in depth. Hopefully it's up-to-date and easier to follow now. Plz comment if anything's unclear.
r? `@oli-obk` I think you're one of the rare other people to understand the exhaustiveness algorithm?
cc `@varkor` I know you're not active anymore, but if you feel like having a look you might enjoy this :D
Fixes https://github.com/rust-lang/rust/issues/79307
Don't ICE when encountering placeholders in implied bounds computation
I *could* fix this the right way, though I don't really want to think about the implications of the change. This should have minimal side-effects.
r? `@aliemjay`
Fixes#118286
coverage: Simplify building coverage expressions based on sums
This is a combination of some interlinked changes to the code that creates coverage counters/expressions for nodes and edges in the coverage graph:
- Some preparatory cleanups in `MakeBcbCounters::make_branch_counters`
- Use `BcbCounter` (instead of `CovTerm`) when building coverage expressions
- This makes it easier to introduce a fold for building sums
- Simplify the creation of coverage expressions based on sums, by having `Iterator::fold` do much of the work
- Get rid of the awkward `BcbBranch` enum, and replace it with graph edges represented as `(from_bcb, to_bcb)`
- This further simplifies the body of the fold
Currently we always do this:
```
use rustc_fluent_macro::fluent_messages;
...
fluent_messages! { "./example.ftl" }
```
But there is no need, we can just do this everywhere:
```
rustc_fluent_macro::fluent_messages! { "./example.ftl" }
```
which is shorter.
The `fluent_messages!` macro produces uses of
`crate::{D,Subd}iagnosticMessage`, which means that every crate using
the macro must have this import:
```
use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
```
This commit changes the macro to instead use
`rustc_errors::{D,Subd}iagnosticMessage`, which avoids the need for the
imports.
Remove `HirId` from `QPath::LangItem`
Remove `HirId` from `QPath::LangItem`, since there was only *one* use-case (`ObligationCauseCode::AwaitableExpr`), which we can instead recover by walking the HIR tree.
Subtree sync for rustc_codegen_cranelift
The main highlights this time are implementing a bunch of new vendor intrinsics and fixing some existing ones. And fixing polymorphization for coroutines.
r? `@ghost`
`@rustbot` label +A-codegen +A-cranelift +T-compiler
Move stuff around on `stable_mir` and `rustc_smir` crate
1. Break down rustc_smir/mod.rs file.
- This file was getting too big and causing a lot of merge conflicts.
All these changes shouldn't be visible to users since this module is private.
2. Move the compiler interface defs to its own module
- Separate items that are exposed in the `stable_mir` crate to be used
by the compiler from items that we expect to be used by tool developers.
Relate Inherent Associated Types using eq
We should call `eq` instead of `sup` as we're relating `Ty` directly and not `Binder<TraitRef>`.
This is part of #118118 but unrelated to that PR.
r? `@compiler-errors` `@lcnr`
Move EagerResolution to rustc_infer::infer::resolve
`EagerResolver` fits better in `rustc_infer::infer::resolver`.
Started to disentagle #118118 that has a lot of unrelated things.
r? `@compiler-errors` `@lcnr`
Replace `option.map(cond) == Some(true)` with `option.is_some_and(cond)`
Requested by `@fmease` in https://github.com/rust-lang/rust/pull/118226#pullrequestreview-1747432292.
There is also a much larger number of `option.map_or(false, cond)` that can be changed separately if someone wants.
r? fmease
Make PlaceholderReplacer shallow_resolver and recur when infer vars
This makes resolve type and const infer vars resolve.
Given:
```rust
#![feature(inherent_associated_types)]
#![allow(incomplete_features)]
struct Foo<T>(T);
impl<'a> Foo<fn(&'a ())> {
type Assoc = &'a ();
}
fn bar(_: for<'a> fn(Foo<fn(Foo<fn(&'static ())>::Assoc)>::Assoc)) {}
fn main() {}
```
We should normalize `for<'a> fn(Foo<fn(Foo<fn(&'static ())>::Assoc)>::Assoc)` to `for<'0> fn(&'1 ())` with `'1 == '0` and `'0 == 'static` constraints. We have to resolve `'1` to `'static` in the infcx associated to `PlaceholderReplacer`.
This is part of https://github.com/rust-lang/rust/pull/118118 but unrelated to that PR.
r? `@compiler-errors` `@lcnr`
Optimize QueryArena allocation
This shifts the WorkerLocal wrapper to be outside the QueryArena, meaning that instead of having each query allocate distinct arenas per-worker we allocate the full set of arenas per-worker. This is primarily a code size optimization (locally, ~85 kilobytes, [perf is reporting >100 kilobytes](https://perf.rust-lang.org/compare.html?start=1fd418f92ed13db88a21865ba5d909abcf16b6cc&end=884c95a3f1fe8d28630ec3cdb0c8f95b2e539fde&stat=instructions%3Au&tab=artifact-size)), saving a bunch of code in the initialization of the arenas which was previously duplicated lots of times (per arena type).
Additionally this tells LLVM that the thread count can't be zero in this code (I believe this is true?) which shaves some small amount of bytes off as well since we eliminate checks for zero in the vec allocations.
`BcbBranch` represented an out-edge of a coverage graph node, but would
silently refer to a node instead in cases where that node only had one in-edge.
Instead we now refer to a graph edge as a `(from_bcb, to_bcb)` pair, or
sometimes as just one of those nodes when the other node is implied by the
surrounding context. The case of sole in-edges is handled by special code added
directly to `get_or_make_edge_counter_operand`.
This was previously a helper method in `MakeBcbCounters`, but putting it in the
graph lets us call it from `BcbBranch`, and gives us a more fine-grained
borrow.
In some cases we need to prepare a coverage expression that is the sum of an
arbitrary number of other terms. This patch simplifies the code paths that
build those sums.
This causes some churn in the mappings, because the previous code was building
its sums in a somewhat idiosyncratic order.
Now that this code path unconditionally calls `make_branch_counters`, we might
as well make that method responsible for creating the node's counter as well,
since it needs the resulting term anyway.
Fixes error count display is different when there's only one error left
Supersedes #114759
### What did I do?
I did the small change in `rustc_errors` by hand. Then I did the other changes in `/compiler` by hand, those were just find replace on `*.rs` in the workspace. The changes in run-make are find replace for `run-make` in the workspace.
All other changes are blessed using `x test TEST --bless`. I blessed the tests that were blessed in #114759.
### how to review this nightmare
ping bors with an `r+`. You should check that my logic is sound and maybe quickly scroll through the diff, but fully verifying it seems fairly hard to impossible. I did my best to do this correctly.
Thank you `@adrianEffe` for bringing this up and your initial implementation.
cc `@flip1995,` you said you want to do a subtree sync asap
cc `@RalfJung` maybe you want to do a quick subtree sync afterwards as well for Miri
r? `@WaffleLapkin`
Add `Span` to `TraitBoundModifier`
This improves diagnostics for the message "`~const` is not allowed here", and also fixes the span that we use when desugaring `~const Tr` into `Tr<host>` in effects desugaring.
EvalCtxt::commit_if_ok don't inherit nested goals
we use it to check whether an alias is rigid, so we want to avoid considering an alias rigid simply because the inference constraints from normalizing it caused another nested goal fail
r? `@compiler-errors`
Add common trait for crate definitions
In stable mir, we specialize DefId, however some functionality is the same for every definition, such as def paths, and getting their crate. Use a trait to implement those.
feat: make `let_binding_suggestion` more reasonable
This is my first PR for rustc, which trying to fix https://github.com/rust-lang/rust/issues/117894, I am not familiar with some internal api so maybe some modification here isn't the way to go, appreciated for any review suggestion.
Cache flags for `ty::Const`
Not sure if this has been attempted yet, but worth a shot. It does make the code simpler in `rustc_type_ir`, since we can assume that consts have a `flags` method that is no-cost.
r? `@ghost`
There were three issues previously:
* The self argument was pinned, despite Iterator::next taking an
unpinned mutable reference.
* A resume argument was passed, despite Iterator::next not having one.
* The return value was CoroutineState<Item, ()> rather than Option<Item>
While these things just so happened to work with the LLVM backend,
cg_clif does much stricter checks when trying to assign a value to a
place. In addition it can't handle the mismatch between the amount of
arguments specified by the FnAbi and the FnSig.
`on_all_children_bits` has two arguments that are unused: `tcx` and
`body`. This was not detected by the compiler because it's a recursive
function.
This commit removes them, and removes lots of other arguments and fields
that are no longer necessary.
Miri: GC the dead_alloc_map too
dead_alloc_map is the last piece of state in the interpreter I can find that leaks. With this PR, all of the long-term memory growth I can find in Miri with programs that do things like run a big `loop {` or run property tests is attributable to some data structure properties in borrow tracking, and is _extremely_ slow.
My only gripe with the commit in this PR is that I don't have a new test for it. I'd like to have a regression test for this, but it would have to be statistical I think because the peak memory of a process that Linux reports is not exactly the same run-to-run. Which means it would have to not be very sensitive to slow leaks (some guesswork suggests for acceptable CI time we would be checking for like 10% memory growth over a minute or two, which is still pretty fast IMO).
Unless someone has a better idea for how to detect a regression, I think on balance I'm fine with manually keeping an eye on the memory use situation.
r? RalfJung
Some types have a `body: &'mir Body<'tcx>` and some have `body: &'a
Body<'tcx>`. The former is more readable, so this commit converts some
fo the latter to the former.
print query map for deadlock when using parallel front end
print query map for deadlock when using parallel front end, so that we can analyze where and why deadlock occurs
Rework supertrait lint once again
I accidentally pushed the wrong commits because I totally didn't check I was on the right computer when updating #118026.
Sorry, this should address all the nits in #118026.
r? lcnr
improve tool-only help for multiple `#[default]` variants
When defining an enum with multiple `#[default]` variants, we emit a tool-only suggestion for every `#[default]`ed variant to remove all other `#[default]`s. This PR improves the suggestion to correctly handle the cases where one variant has multiple `#[default]`s and where different `#[default]`s have the same span due to macro expansions.
fixes https://github.com/rust-lang/rust/issues/118119
Remove `PredicateKind::ClosureKind`
We don't need the `ClosureKind` predicate kind -- instead, `Fn`-family trait goals are left as ambiguous, and we only need to make progress on `FnOnce` projection goals for inference purposes.
This is similar to how we do confirmation of `Fn`-family trait and projection goals in the new trait solver, which also doesn't use the `ClosureKind` predicate.
Some hacky logic is added in the second commit so that we can keep the error messages the same.
We currently provide only a `help` message, this PR introduces the last
two structured suggestions instead:
```
error[E0308]: mismatched types
--> $DIR/issue-98982.rs:2:5
|
LL | fn foo() -> i32 {
| --- expected `i32` because of return type
LL | / for i in 0..0 {
LL | | return i;
LL | | }
| |_____^ expected `i32`, found `()`
|
note: the function expects a value to always be returned, but loops might run zero times
--> $DIR/issue-98982.rs:2:5
|
LL | for i in 0..0 {
| ^^^^^^^^^^^^^ this might have zero elements to iterate on
LL | return i;
| -------- if the loop doesn't execute, this value would never get returned
help: return a value for the case when the loop has zero elements to iterate on
|
LL ~ }
LL ~ /* `i32` value */
|
help: otherwise consider changing the return type to account for that possibility
|
LL ~ fn foo() -> Option<i32> {
LL | for i in 0..0 {
LL ~ return Some(i);
LL ~ }
LL ~ None
|
```
Fix#98982.
Rollup of 6 pull requests
Successful merges:
- #118012 (Add support for global allocation in smir)
- #118013 (Enable Rust to use the EHCont security feature of Windows)
- #118100 (Enable profiler in dist-powerpc64-linux)
- #118142 (Tighten up link attributes for llvm-wrapper bindings)
- #118147 (Fix some unnecessary casts)
- #118161 (Allow defining opaques in `check_coroutine_obligations`)
r? `@ghost`
`@rustbot` modify labels: rollup
Allow defining opaques in `check_coroutine_obligations`
In the new trait solver, when an obligation stalls on an unresolved coroutine witness, we will stash away the *root* obligation, even if the stalled obligation is only a distant descendent of the root obligation, since the new solver is purely recursive.
This means that we may need to reprocess alias-relate obligations (and others) which may define opaque types in the new solver. Currently, we use the coroutine's def id as the defining anchor in `check_coroutine_obligations`, which will allow defining no opaque types, resulting in errors like:
```
error[E0271]: type mismatch resolving `{coroutine@<source>:6:5: 6:17} <: impl Clone`
--> <source>:6:5
|
6 | / move |_: ()| {
7 | | let () = yield ();
8 | | }
| |_____^ types differ
```
So this PR fixes the defining anchor and does the same trick as `check_opaque_well_formed`, where we manually compare opaques that were defined against their hidden types to make sure they weren't defined differently when processing these stalled coroutine obligations.
r? `@lcnr` cc `@cjgillot`
Tighten up link attributes for llvm-wrapper bindings
Fixes https://github.com/rust-lang/rust/issues/118084 by moving all of the declarations of symbols from `llvm_rust` into a separate extern block with `#[link(name = "llvm-wrapper", kind = "static")]`.
This also renames `LLVMTimeTraceProfiler*` to `LLVMRustTimeTraceProfiler*` because those are functions from `llvm_rust`.
r? tmiasko
Enable Rust to use the EHCont security feature of Windows
In the future Windows will enable Control-flow Enforcement Technology (CET aka Shadow Stacks). To protect the path where the context is updated during exception handling, the binary is required to enumerate valid unwind entrypoints in a dedicated section which is validated when the context is being set during exception handling.
The required support for EHCONT Guard has already been merged into LLVM, long ago. This change simply adds the Rust codegen option to enable it.
Relevant LLVM change: https://reviews.llvm.org/D40223
This also adds a new `ehcont-guard` option to the bootstrap config which enables EHCont Guard when building std.
We at Microsoft have been using this feature for a significant period of time; we are confident that the LLVM feature, when enabled, generates well-formed code.
We currently enable EHCONT using a codegen feature, but I'm certainly open to refactoring this to be a target feature instead, or to use any appropriate mechanism to enable it.
Add support for global allocation in smir
Add APIs to StableMir to support global allocation. Before this change, StableMir users had no API available to retrieve Allocation provenance information. They had to resource to internal APIs instead.
One example is retrieving the Allocation of an `&str`. See test for an example on how the API can be used.
Add allow-by-default lint for unit bindings
### Example
```rust
#![warn(unit_bindings)]
macro_rules! owo {
() => {
let whats_this = ();
}
}
fn main() {
// No warning if user explicitly wrote `()` on either side.
let expr = ();
let () = expr;
let _ = ();
let _ = expr; //~ WARN binding has unit type
let pat = expr; //~ WARN binding has unit type
let _pat = expr; //~ WARN binding has unit type
// No warning for let bindings with unit type in macro expansions.
owo!();
// No warning if user explicitly annotates the unit type on the binding.
let pat: () = expr;
}
```
outputs
```
warning: binding has unit type `()`
--> $DIR/unit-bindings.rs:17:5
|
LL | let _ = expr;
| ^^^^-^^^^^^^^
| |
| this pattern is inferred to be the unit type `()`
|
note: the lint level is defined here
--> $DIR/unit-bindings.rs:3:9
|
LL | #![warn(unit_bindings)]
| ^^^^^^^^^^^^^
warning: binding has unit type `()`
--> $DIR/unit-bindings.rs:18:5
|
LL | let pat = expr;
| ^^^^---^^^^^^^^
| |
| this pattern is inferred to be the unit type `()`
warning: binding has unit type `()`
--> $DIR/unit-bindings.rs:19:5
|
LL | let _pat = expr;
| ^^^^----^^^^^^^^
| |
| this pattern is inferred to be the unit type `()`
warning: 3 warnings emitted
```
This lint is not triggered if any of the following conditions are met:
- The user explicitly annotates the binding with the `()` type.
- The binding is from a macro expansion.
- The user explicitly wrote `let () = init;`
- The user explicitly wrote `let pat = ();`. This is allowed for local lifetimes.
### Known Issue
It is known that this lint can trigger on some proc-macro generated code whose span returns false for `Span::from_expansion` because e.g. the proc-macro simply forwards user code spans, and otherwise don't have distinguishing syntax context compared to non-macro-generated code. For those kind of proc-macros, I believe the correct way to fix them is to instead emit identifers with span like `Span::mixed_site().located_at(user_span)`.
Closes#71432.
Make some `newtype_index!` derived impls opt-in instead of opt-out
Opt-in is the standard Rust way of doing things, and avoids some unnecessary dependencies on the `rustc_serialize` crate.
r? `@lcnr`
By default, `newtype_index!` types get a default `Encodable`/`Decodable`
impl. You can opt out of this with `custom_encodable`. Opting out is the
opposite to how Rust normally works with autogenerated (derived) impls.
This commit inverts the behaviour, replacing `custom_encodable` with
`encodable` which opts into the default `Encodable`/`Decodable` impl.
Only 23 of the 59 `newtype_index!` occurrences need `encodable`.
Even better, there were eight crates with a dependency on
`rustc_serialize` just from unused default `Encodable`/`Decodable`
impls. This commit removes that dependency from those eight crates.
Remove `feature` from the list of well known check-cfg name
This PR removes `feature` from the list of well known check-cfg.
This is done for multiple reasons:
- Cargo is the source of truth, rustc shouldn't have any knowledge of it
- It creates a conflict between Cargo and rustc when there are no features defined.
In this case Cargo won't pass any `--check-cfg` for `feature` since no feature will ever be passed, but rustc by having in it's list adds a implicit `cfg(feature, values(any()))` which is completely wrong. Having any cfg `feature` is unexpected not allow any `feature` value.
While doing this, I took the opportunity to specialise the diagnostic a bit for the case above.
r? `@petrochenkov`
Uplift `CanonicalVarInfo` and friends into `rustc_type_ir`
Depends on #117580 and #117578
Uplift `CanonicalVarInfo` and friends into `rustc_type_ir` so they can be consumed by an interner-agnostic `Canonicalizer` implementation for the new trait solver ❤️
r? `@ghost`
This disentangles the row-specific tracking of `parent_row` etc from the
logical operation of specialization. This means `wildcard_row` doesn't
need to provide dummy values for `parent_row` etc anymore.
Rollup of 5 pull requests
Successful merges:
- #117972 (Add VarDebugInfo to Stable MIR)
- #118109 (rustdoc-search: simplify `checkPath` and `sortResults`)
- #118110 (Document `DefiningAnchor` a bit more)
- #118112 (Don't ICE when ambiguity is found when selecting `Index` implementation in typeck)
- #118135 (Remove quotation from filename in stable_mir)
Failed merges:
- #118012 (Add support for global allocation in smir)
r? `@ghost`
`@rustbot` modify labels: rollup
Remove quotation from filename in stable_mir
Previously we had quotation marks in filenames which is obviously wrong this fixes that.
r? ```@celinval```
Don't ICE when ambiguity is found when selecting `Index` implementation in typeck
Fixes#118111
The problem here is when we're manually "selecting" an impl for `base_ty: Index<?0>`, we don't consider placeholder region errors (leak check) or ambiguous predicates. Those can lead to us not actually emitting any fulfillment errors on line 3131.
Add VarDebugInfo to Stable MIR
Previously we omitted `VarDebugInfo` because we didn't have `Projection` now that https://github.com/rust-lang/rust/pull/117517 is merged it's possible to add `VarDebugInfo` information in `Body`. This PR adds stable version of the `VarDebugInfo` to `Body`
r? ```@celinval```
In the future Windows will enable Control-flow Enforcement Technology
(CET aka Shadow Stacks). To protect the path where the context is
updated during exception handling, the binary is required to enumerate
valid unwind entrypoints in a dedicated section which is validated when
the context is being set during exception handling.
The required support for EHCONT has already been merged into LLVM,
long ago. This change adds the Rust codegen option to enable it.
Reference:
* https://reviews.llvm.org/D40223
This also adds a new `ehcont-guard` option to the bootstrap config which
enables EHCont Guard when building std.
The AST and HIR versions of `State::print_ident` are textually
identical, but the types differ slightly. This commit factors out the
common code they both have by replacing `print_ident` with `ann_post`,
which is a smaller function that still captures the type difference.
`PrintState` is a trait containing code that can be used by both AST and
HIR pretty-printing. But several of its methods are only used by AST
printing.
This commit moves those methods out of the trait and into the AST
`State` impl, so they are not exposed unnecessarily. This commit also
removes four unused methods: `param_to_string`,
`foreign_item_to_string`, `assoc_item_to_string`, and
`print_inner_attributes_inline`.
