Fix hang in where-clause suggestion with `predicate_can_apply`
Using `predicate_may_hold` during error reporting causes an evaluation overflow, which (because we use `evaluate_obligation_no_overflow`) then causes the predicate to need to be re-evaluated locally, which results in a hang.
... but since the "add a where clause" suggestion is best-effort, just throw any overflow errors. No need for 100% accuracy.
r? `@lcnr` who has been thinking about overflows... Let me know if you want more context about this issue, and as always, feel free to reassign.
Fixes#104225
optimize field ordering by grouping m*2^n-sized fields with equivalently aligned ones
```rust
use std::ptr::addr_of;
use std::mem;
struct Foo {
word: u32,
byte: u8,
ary: [u8; 4]
}
fn main() {
let foo: Foo = unsafe { mem::zeroed() };
println!("base: {:p}\nword: {:p}\nbyte: {:p}\nary: {:p}", &foo, addr_of!(foo.word), addr_of!(foo.byte), addr_of!(foo.ary));
}
```
prints
```
base: 0x7fffc1a8a668
word: 0x7fffc1a8a668
byte: 0x7fffc1a8a66c
ary: 0x7fffc1a8a66d
```
I.e. the `u8` in the middle causes the array to sit at an odd offset, which might prevent optimizations, especially on architectures where unaligned loads are costly.
Note that this will make field ordering niche-dependent, i.e. a `Bar<T>` with `T=char` and `T=u32` may result in different field order, this may break some code that makes invalid assumptions about `repr(Rust)` types.
Lower return type outside async block creation
This allows feeding a different output type to async blocks with a different `ImplTraitContext`. Spotted this while working on #104321
Refactor must_use lint into two parts
Before, the lint did the checking for `must_use` and pretty printing the types in a special format in one pass, causing quite complex and untranslatable code.
Now the collection and printing is split in two. That should also make it easier to translate or extract the type pretty printing in the future.
Also fixes an integer overflow in the array length pluralization
calculation.
fixes#104352
Use `tcx.require_lang_item` instead of unwrapping lang items
I clearly remember esteban telling me that there is `require_lang_item` but he was from a phone atm and I couldn't find it, so I didn't use it. Stumbled on it today, so here we are :)
Remove a lifetime resolution hack from `compare_predicate_entailment`
This is not needed anymore, probably due to #102334 equating the function signatures fully in `collect_trait_impl_trait_tys`. Also, the assertion in in #102903 makes sure that this is actually fixed, so I'm pretty confident this isn't needed.
Only declare bindings for if-let guards once per arm
Currently, each candidate for a match arm uses separate locals for the bindings in the if-let guard, causing problems (#88015) when those branches converge in the arm body.
Fixes#88015 (🤞)
Check generics parity before collecting return-position `impl Trait`s in trait
The only thing is that this duplicates the error message for number of generics mismatch, but we already deduplicate that error message in Cargo. I could add a flag to delay the error if the reviewer cares.
Fixes#104281
Also drive-by adds a few comments to the `collect_trait_impl_trait_tys` method, and removes an unused argument from `compare_number_of_generics`.
Rollup of 11 pull requests
Successful merges:
- #103396 (Pin::new_unchecked: discuss pinning closure captures)
- #104416 (Fix using `include_bytes` in pattern position)
- #104557 (Add a test case for async dyn* traits)
- #104559 (Split `MacArgs` in two.)
- #104597 (Probe + better error messsage for `need_migrate_deref_output_trait_object`)
- #104656 (Move tests)
- #104657 (Do not check transmute if has non region infer)
- #104663 (rustdoc: factor out common button CSS)
- #104666 (Migrate alias search result to CSS variables)
- #104674 (Make negative_impl and negative_impl_exists take the right types)
- #104692 (Update test's cfg-if dependency to 1.0)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Probe + better error messsage for `need_migrate_deref_output_trait_object`
1. Use `InferCtxt::probe` in `need_migrate_deref_output_trait_object` -- that normalization *could* technically do type inference as a side-effect, and this is a lint, so it should have no side-effects.
2. Return the trait-ref so we format the error message correctly. See the UI test change -- `(dyn A + 'static)` is not a trait.
Split `MacArgs` in two.
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`), where only the `Delimited` variant is used.
In other words, `MacArgs` is used in two quite different places due to them having partial overlap. I find this makes the code hard to read. It also leads to various unreachable code paths, and allows invalid values (such as accidentally using `MacArgs::Empty` in a `MacCall`).
This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro case. Its `Delimited` variant now contains a `DelimArgs`.
Various other related things are renamed as well.
These changes make the code clearer, avoids several unreachable paths, and disallows the invalid values.
r? `@petrochenkov`
`MacArgs` is an enum with three variants: `Empty`, `Delimited`, and `Eq`. It's
used in two ways:
- For representing attribute macro arguments (e.g. in `AttrItem`), where all
three variants are used.
- For representing function-like macros (e.g. in `MacCall` and `MacroDef`),
where only the `Delimited` variant is used.
In other words, `MacArgs` is used in two quite different places due to them
having partial overlap. I find this makes the code hard to read. It also leads
to various unreachable code paths, and allows invalid values (such as
accidentally using `MacArgs::Empty` in a `MacCall`).
This commit splits `MacArgs` in two:
- `DelimArgs` is a new struct just for the "delimited arguments" case. It is
now used in `MacCall` and `MacroDef`.
- `AttrArgs` is a renaming of the old `MacArgs` enum for the attribute macro
case. Its `Delimited` variant now contains a `DelimArgs`.
Various other related things are renamed as well.
These changes make the code clearer, avoids several unreachable paths, and
disallows the invalid values.
Rollup of 9 pull requests
Successful merges:
- #104420 (Fix doc example for `wrapping_abs`)
- #104499 (rustdoc JSON: Use `Function` everywhere and remove `Method`)
- #104500 (`rustc_ast`: remove `ref` patterns)
- #104511 (Mark functions created for `raw-dylib` on x86 with DllImport storage class)
- #104595 (Add `PolyExistentialPredicate` type alias)
- #104605 (deduplicate constant evaluation in cranelift backend)
- #104628 (Revert "Update CI to use Android NDK r25b")
- #104662 (Streamline deriving on packed structs.)
- #104667 (Revert formatting changes of a test)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Streamline deriving on packed structs.
The current approach to field accesses in derived code:
- Normal case: `&self.0`
- In a packed struct that derives `Copy`: `&{self.0}`
- In a packed struct that doesn't derive `Copy`: `let Self(ref x) = *self`
The `let` pattern used in the third case is equivalent to the simpler field access in the first case. This commit changes the third case to use a field access.
The commit also combines two boolean arguments (`is_packed` and `always_copy`) into a single field (`copy_fields`) earlier, to save passing both around.
r? ``@jackh726``
deduplicate constant evaluation in cranelift backend
The cranelift backend had two matches on `ConstantKind`, which can be avoided, and used this `eval_for_mir` that nothing else uses... this makes things more consistent with the (better-tested) LLVM backend.
I noticed this because cranelift was the only user of `eval_for_mir`. However `try_eval_for_mir` still has one other user in `eval`... the odd thing is that the interpreter has its own `eval_mir_constant` which seems to duplicate the same functionality and does not use `try_eval_for_mir`. No idea what is happening here.
r? ``@bjorn3``
Cc ``@lcnr``
Add `PolyExistentialPredicate` type alias
Wrapping `ExistentialPredicate`s in a binder is very common, and this alias already exists for the `PolyExistential{TraitRef,Projection}` types.
Mark functions created for `raw-dylib` on x86 with DllImport storage class
Fix for #104453
## Issue Details
On x86 Windows, LLVM uses 'L' as the prefix for any private global symbols (`PrivateGlobalPrefix`), so when the `raw-dylib` feature creates an undecorated function symbol that begins with an 'L' LLVM misinterprets that as a private global symbol that it created and so fails the compilation at a later stage since such a symbol must have a definition.
## Fix Details
Mark the function we are creating for `raw-dylib` with `DllImport` storage class (this was already being done for MSVC at a later point for `callee::get_fn` but not for GNU (due to "backwards compatibility")): this will cause LLVM to prefix the name with `__imp_` and so it won't mistake it for a private global symbol.
Support using `Self` or projections inside an RPIT/async fn
I reuse the same idea as https://github.com/rust-lang/rust/pull/103449 to use variances to encode whether a lifetime parameter is captured by impl-trait.
The current implementation of async and RPIT replace all lifetimes from the parent generics by `'static`. This PR changes the scheme
```rust
impl<'a> Foo<'a> {
fn foo<'b, T>() -> impl Into<Self> + 'b { ... }
}
opaque Foo::<'_a>::foo::<'_b, T>::opaque<'b>: Into<Foo<'_a>> + 'b;
impl<'a> Foo<'a> {
// OLD
fn foo<'b, T>() -> Foo::<'static>::foo::<'static, T>::opaque::<'b> { ... }
^^^^^^^ the `Self` becomes `Foo<'static>`
// NEW
fn foo<'b, T>() -> Foo::<'a>::foo::<'b, T>::opaque::<'b> { ... }
^^ the `Self` stays `Foo<'a>`
}
```
There is the same issue with projections. In the example, substitute `Self` by `<T as Trait<'b>>::Assoc` in the sugared version, and `Foo<'_a>` by `<T as Trait<'_b>>::Assoc` in the desugared one.
This allows to support `Self` in impl-trait, since we do not replace lifetimes by `'static` any more. The same trick allows to use projections like `T::Assoc` where `Self` is allowed. The feature is gated behind a `impl_trait_projections` feature gate.
The implementation relies on 2 tweaking rules for opaques in 2 places:
- we only relate substs that correspond to captured lifetimes during TypeRelation;
- we only list captured lifetimes in choice region computation.
For simplicity, I encoded the "capturedness" of lifetimes as a variance, `Bivariant` vs `Invariant` for unused vs captured lifetimes. The `variances_of` query used to ICE for opaques.
Impl-trait that do not reference `Self` or projections will have their variances as:
- `o` (invariant) for each parent type or const;
- `*` (bivariant) for each parent lifetime --> will not participate in borrowck;
- `o` (invariant) for each own lifetime.
Impl-trait that does reference `Self` and/or projections will have some parent lifetimes marked as `o` (as the example above), and participate in type relation and borrowck. In the example above, `variances_of(opaque) = ['_a: o, '_b: *, T: o, 'b: o]`.
r? types
cc `@compiler-errors` , as you asked about the issue with `Self` and projections.
The current approach to field accesses in derived code:
- Normal case: `&self.0`
- In a packed struct that derives `Copy`: `&{self.0}`
- In a packed struct that doesn't derive `Copy`: `let Self(ref x) = *self`
The `let` pattern used in the third case is equivalent to the simpler
field access in the first case. This commit changes the third case to
use a field access.
The commit also combines two boolean arguments (`is_packed` and
`always_copy`) into a single field (`copy_fields`) earlier, to save
passing both around.
Pass 128-bit C-style enum enumerator values to LLVM
Pass the full 128 bits of C-style enum enumerators through to LLVM. This means that debuginfo for C-style repr128 enums is now emitted correctly for DWARF platforms (as compared to not being correctly emitted on any platform).
Tracking issue: #56071
Add a detailed note for missing comma typo w/ FRU syntax
Thanks to `@pierwill` for working on this with me!
Fixes#104373, perhaps `@alice-i-cecile` can comment on the new error for the example provided on that issue -- feedback is welcome.
```
error[E0063]: missing field `defaulted` in initializer of `Outer`
--> $DIR/multi-line-fru-suggestion.rs:14:5
|
LL | Outer {
| ^^^^^ missing `defaulted`
|
note: this expression may have been misinterpreted as a `..` range expression
--> $DIR/multi-line-fru-suggestion.rs:16:16
|
LL | inner: Inner {
| ________________^
LL | | a: 1,
LL | | b: 2,
LL | | }
| |_________^ this expression does not end in a comma...
LL | ..Default::default()
| ^^^^^^^^^^^^^^^^^^^^ ... so this is interpreted as a `..` range expression, instead of functional record update syntax
help: to set the remaining fields from `Default::default()`, separate the last named field with a comma
|
LL | },
| +
error: aborting due to previous error
For more information about this error, try `rustc --explain E0063`.
```
Check fat pointer metadata compatibility modulo regions
Regions don't really mean anything anyways during hir typeck.
If this `erase_regions` makes anyone nervous, it's probably equally valid to just equate the types using a type relation, but regardless we should _not_ be using strict type equality while region variables are present.
Fixes#103384
Rollup of 6 pull requests
Successful merges:
- #103901 (Add tracking issue for `const_arguments_as_str`)
- #104112 (rustdoc: Add copy to the description of repeat)
- #104435 (`VecDeque::resize` should re-use the buffer in the passed-in element)
- #104467 (Fix substraction with overflow in `wrong_number_of_generic_args.rs`)
- #104608 (Cleanup macro matching recovery)
- #104626 (Fix doctest errors related to rustc_middle)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Cleanup macro matching recovery
The retry has been implemented already in #104335. Also removes a `HACK` comment that's not really needed anymore because the "don't recover during macro matching" isn't really a hack but correct behavior.
Fix substraction with overflow in `wrong_number_of_generic_args.rs`
Fixes#104287
This issue happens in the `suggest_moving_args_from_assoc_fn_to_trait_for_qualified_path` function, which seems to run before the error checking facilities can catch an invalid use of generic arguments. Thus we get a subtraction with overflow because the code implicitly assumes that the source program makes sense (or is this assumption not true even if the program is correct?).
try_normalize_after_erasing_regions: promote an assertion to always run
In https://github.com/rust-lang/miri/issues/2433 this assertion has been seen to trigger, so it might be worth actually checking this? Regressing debug assertions are very easy to miss until much later, and then they become quite hard to debug.
Before, the lint did the checking for `must_use` and pretty printing the
types in a special format in one pass, causing quite complex and
untranslatable code.
Now the collection and printing is split in two. That should also make
it easier to translate or extract the type pretty printing in the
future.
Also fixes an integer overflow in the array length pluralization
calculation.
Rarranging the substration and equality check into an addition and an equality
check is sufficient.
Algebra is cool, isn't it?
Co-authored-by: Michael Goulet <michael@errs.io>
Improve spans for RPITIT object-safety errors
No reason why we can't point at the `impl Trait` that causes the object-safety violation.
Also [drive-by: Add is_async fn to hir::IsAsync](c4165f3a96), which touches clippy too.
Make "long type" printing type aware and trim types in E0275
Instead of simple string cutting, use a custom printer to hide parts of long printed types.
On E0275, check for type length before printing.
Use `IsTerminal` in place of `atty`
In any crate that can use nightly features, use `IsTerminal` rather than
`atty`:
- Use `IsTerminal` in `rustc_errors`
- Use `IsTerminal` in `rustc_driver`
- Use `IsTerminal` in `rustc_log`
- Use `IsTerminal` in `librustdoc`
Revert "Normalize opaques with escaping bound vars"
This caused a perf regression in #103423, cc `@skyzh` this should fix#103423.
reverts #100980
r? `@oli-obk`
Use `ErrorGuaranteed::unchecked_claim_error_was_emitted` less
there are only like 3 or 4 call sites left after this but it wasnt obvious to me how to remove them
nll: correctly deal with bivariance
fixes#104409
when in a bivariant context, relating stuff should always trivially succeed. Also changes the mir validator to correctly deal with higher ranked regions.
r? types cc ``@RalfJung``
Improve generating Custom entry function
This commit is aimed at making compiler-generated entry functions (Basically just C `main` right now) more generic so other targets can do similar things for custom entry. This was initially implemented as part of https://github.com/rust-lang/rust/pull/100316.
Currently, this moves the entry function name and Call convention to the target spec.
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
Use liballoc's specialised in-place vec collection
liballoc already specialises in-place vector collection, so manually
reimplementing it in `IdFunctor::try_map_id` was superfluous.
Rollup of 8 pull requests
Successful merges:
- #102977 (remove HRTB from `[T]::is_sorted_by{,_key}`)
- #103378 (Fix mod_inv termination for the last iteration)
- #103456 (`unchecked_{shl|shr}` should use `u32` as the RHS)
- #103701 (Simplify some pointer method implementations)
- #104047 (Diagnostics `icu4x` based list formatting.)
- #104338 (Enforce that `dyn*` coercions are actually pointer-sized)
- #104498 (Edit docs for `rustc_errors::Handler::stash_diagnostic`)
- #104556 (rustdoc: use `code-header` class to format enum variants)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Edit docs for `rustc_errors::Handler::stash_diagnostic`
Clarify that the diagnostic can be retrieved with `steal_diagnostic`.
r? ```@compiler-errors```
Enforce that `dyn*` coercions are actually pointer-sized
Implement a perma-unstable, rudimentary `PointerSized` trait to enforce `dyn*` casts are `usize`-sized for now, at least to prevent ICEs and weird codegen issues from cropping up after monomorphization since currently we enforce *nothing*.
This probably can/should be removed in favor of a more sophisticated trait for handling `dyn*` conversions when we decide on one, but I just want to get something up for discussion and experimentation for now.
r? ```@eholk``` cc ```@tmandry``` (though feel free to claim/reassign)
Fixes#102141Fixes#102173
Rollup of 8 pull requests
Successful merges:
- #101162 (Migrate rustc_resolve to use SessionDiagnostic, part # 1)
- #103386 (Don't allow `CoerceUnsized` into `dyn*` (except for trait upcasting))
- #103405 (Detect incorrect chaining of if and if let conditions and recover)
- #103594 (Fix non-associativity of `Instant` math on `aarch64-apple-darwin` targets)
- #104006 (Add variant_name function to `LangItem`)
- #104494 (Migrate GUI test to use functions)
- #104516 (rustdoc: clean up sidebar width CSS)
- #104550 (fix a typo)
Failed merges:
- #104554 (Use `ErrorGuaranteed::unchecked_claim_error_was_emitted` less)
r? `@ghost`
`@rustbot` modify labels: rollup
`_` might confuse people into believing that the type isn't known,
while `...` is not used anywhere else for types and is not valid
syntax, making it more likely to convey the right understanding.
