Better handle when trying to iterate on a `Range` of a type that isn't `Step`
Mention when a trait bound corresponds to an unstable trait.
Mention `Range` when `Step` bound is unment, and explain that only some std types impl `Iterator` for `Range`.
CC rust-lang/rust#151026
diagnostics: make implicit Sized bounds explicit in E0277
When a trait parameter depends upon Sized, the error message only referred to the full trait itself and didn't mention Sized. This makes the failure to implement Sized explicit. It also notes when the Sized trait bound is explicit or implicit.
Fixesrust-lang/rust#150576
When a closure has an inferred parameter type like `|ch|` and the
expected type differs in borrowing (e.g., `char` vs `&char`), the
suggestion code would incorrectly suggest `|char|` instead of the
valid `|ch: char|`.
This happened because the code couldn't walk explicit `&` references
in the HIR when the type is inferred, and fell back to replacing the
entire parameter span with the expected type name.
Fix by only emitting the suggestion when we can properly identify the
`&` syntax to remove.
- Remove the vacuous `Types`, which provides extremely little value.
- Make sure `src` comes before `dst` in all transmute-related functions.
(Currently it's a mix: sometimes `src` is first, sometimes it is
second`.)
When a trait parameter depends upon Sized, the error message only
referred to the full trait itself and didn't mention Sized. This makes
the failure to implement Sized explicit. It also notes when the Sized
trait bound is explicit or implicit.
Removed confusing diagnostics note for trait required for `?` operator use
- **test: modified `bad-question-mark-on-trait-objects` to match expected behavior**
- **removed confusing message from diagnostics**
fixes [#150527](https://github.com/rust-lang/rust/issues/150527)
Detect cases where `?` is applied on a type that could be coming from a different crate version than expected
```
error[E0277]: `?` couldn't convert the error to `dependency::Error`
--> replaced
|
LL | fn main() -> Result<(), Error> {
| ----------------- expected `dependency::Error` because of this
...
LL | Err(Error2)?;
| -----------^ the trait `From<Error2>` is not implemented for `dependency::Error`
| |
| this can't be annotated with `?` because it has type `Result<_, Error2>`
|
= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
help: the trait `From<Error2>` is not implemented for `dependency::Error`
but trait `From<()>` is implemented for it
--> replaced
|
LL | impl From<()> for Error {
| ^^^^^^^^^^^^^^^^^^^^^^^
= help: for that trait implementation, expected `()`, found `Error2`
= note: there are multiple different versions of crate `dependency` in the dependency graph
= help: you can use `cargo tree` to explore your dependency tree
```
The existing checks rely on having access to the actual types/traits that diverged to detect they are called the same, come from different crates with the same name. The new check is less specific, merely looking to see if the crate name the involved type belongs has multiple crates.
CC rust-lang/rust#78552.
```
error[E0277]: `?` couldn't convert the error to `dependency::Error`
--> replaced
|
LL | fn main() -> Result<(), Error> {
| ----------------- expected `dependency::Error` because of this
...
LL | Err(Error2)?;
| -----------^ the trait `From<Error2>` is not implemented for `dependency::Error`
| |
| this can't be annotated with `?` because it has type `Result<_, Error2>`
|
= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
help: the trait `From<Error2>` is not implemented for `dependency::Error`
but trait `From<()>` is implemented for it
--> replaced
|
LL | impl From<()> for Error {
| ^^^^^^^^^^^^^^^^^^^^^^^
= help: for that trait implementation, expected `()`, found `Error2`
= note: there are multiple different versions of crate `dependency` in the dependency graph
= help: you can use `cargo tree` to explore your dependency tree
```
The existing checks rely on having access to the actual types/traits that diverged to detect they are called the same, come from different crates with the same name. The new check is less specific, merely looking to see if the crate name the involved type belongs has multiple crates.
Simplify `TypeFreshener` methods.
`freshen_{ty,const}` take a `Result` and just do a fold if the input is `Ok`. It's simpler to do those folds at the call site, and only call `freshen_{ty,const}` in the `Err` case. That way we can also avoid useless fold operations on the results of `new_{int,uint,float}`.
Also, make some `bug!` calls more concise.
r? `@lcnr`
Sometimes we freshen using a new `TypeFreshener`, and sometimes we
freshen with an existing `TypeFreshener`. For the former we have the
method `InferCtxt::freshen`. For the latter we just call `fold_with`.
This asymmetry has been confusing to me.
This commit removes `InferCtxt::freshen` so that all the freshening
sites consistently use `fold_with` and it's obvious if each one is using
a new or existing `TypeFreshener`.
I have always found this confusingly named, because it creates a new
freshener rather than returning an existing one. We can remove it and
just use `TypeFreshener::new()` at the two call sites, avoiding this
confusion.
Fix span note for question mark expression
Fixesrust-lang/rust#144304
Seems it's better to fix the note instead of modifying the span to cover the whole expression.
r? `@estebank`
Extend well-formedness checking and HIR analysis to prohibit the use of
scalable vectors in structs, enums, unions, tuples and arrays. LLVM does
not support scalable vectors being members of other types, so these
restrictions are necessary.
Co-authored-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Move `struct Placeholder<T>`
r? ghost
Couple of issues I've encountered;
- `compiler/rustc_infer/src/infer/region_constraints/mod.rs` `GenericKind` I can't call `write!(f, "{p}")` due to error 1. Which looks like I may need to implement `Lift` for `Placeholder`?
- Using the `define_print_and_forward_display!` for `ty::PlaceholderType` caused error 2, as I've moved the struct it no longer exists in the crate. I suspect because I'm not using that macro it causes the error for `GenericKind`
<details>
<summary>Error 1</summary>
```
error: lifetime may not live long enough
--> compiler/rustc_infer/src/infer/region_constraints/mod.rs:672:38
|
668 | impl<'tcx> fmt::Display for GenericKind<'tcx> {
| ---- lifetime `'tcx` defined here
...
672 | GenericKind::Placeholder(ref p) => write!(f, "{p}"),
| ^^^^^ assignment requires that `'tcx` must outlive `'static`
|
= note: requirement occurs because of the type `rustc_middle::ty::TyCtxt<'_>`, which makes the generic argument `'_` invariant
= note: the struct `rustc_middle::ty::TyCtxt<'tcx>` is invariant over the parameter `'tcx`
= help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
error: implementation of `Lift` is not general enough
--> compiler/rustc_infer/src/infer/region_constraints/mod.rs:672:38
|
672 | GenericKind::Placeholder(ref p) => write!(f, "{p}"),
| ^^^^^ implementation of `Lift` is not general enough
|
= note: `Lift<rustc_middle::ty::TyCtxt<'0>>` would have to be implemented for the type `rustc_type_ir::Placeholder<rustc_middle::ty::TyCtxt<'_>, BoundTy>`, for any lifetime `'0`...
= note: ...but `Lift<rustc_middle::ty::TyCtxt<'1>>` is actually implemented for the type `rustc_type_ir::Placeholder<rustc_middle::ty::TyCtxt<'1>, BoundTy>`, for some specific lifetime `'1`
error: implementation of `Print` is not general enough
--> compiler/rustc_infer/src/infer/region_constraints/mod.rs:672:38
|
672 | GenericKind::Placeholder(ref p) => write!(f, "{p}"),
| ^^^^^ implementation of `Print` is not general enough
```
</details>
<details>
<summary>Error 2</summary>
```
error[E0117]: only traits defined in the current crate can be implemented for arbitrary types
--> compiler/rustc_middle/src/ty/print/pretty.rs:3060:38
|
3057 | / macro_rules! forward_display_to_print {
3058 | | ($($ty:ty),+) => {
3059 | | // Some of the $ty arguments may not actually use 'tcx
3060 | | $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
... |
3072 | | };
3073 | | }
| |_- in this expansion of `forward_display_to_print!`
...
3093 | / forward_display_to_print! {
3094 | | ty::Region<'tcx>,
3095 | | Ty<'tcx>,
3096 | | &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
3097 | | ty::Const<'tcx>,
3098 | | &'tcx ty::PlaceholderType<'tcx>
| | ------------------------------- `rustc_type_ir::Placeholder` is not defined in the current crate
3099 | | }
| |_- in this macro invocation
|
= note: impl doesn't have any local type before any uncovered type parameters
= note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
= note: define and implement a trait or new type instead
error: implementation of `Lift` is not general enough
--> compiler/rustc_middle/src/ty/print/pretty.rs:3060:38
|
3057 | / macro_rules! forward_display_to_print {
3058 | | ($($ty:ty),+) => {
3059 | | // Some of the $ty arguments may not actually use 'tcx
3060 | | $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Lift` is not general enough
... |
3072 | | };
3073 | | }
| |_- in this expansion of `forward_display_to_print!`
...
3093 | / forward_display_to_print! {
3094 | | ty::Region<'tcx>,
3095 | | Ty<'tcx>,
3096 | | &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
3097 | | ty::Const<'tcx>,
3098 | | &'tcx ty::PlaceholderType<'tcx>
3099 | | }
| |_- in this macro invocation
|
= note: `Lift<context::TyCtxt<'0>>` would have to be implemented for the type `rustc_type_ir::Placeholder<context::TyCtxt<'tcx>, BoundTy>`, for any lifetime `'0`...
= note: ...but `Lift<context::TyCtxt<'1>>` is actually implemented for the type `rustc_type_ir::Placeholder<context::TyCtxt<'1>, BoundTy>`, for some specific lifetime `'1`
error: implementation of `print::Print` is not general enough
--> compiler/rustc_middle/src/ty/print/pretty.rs:3060:38
|
3057 | / macro_rules! forward_display_to_print {
3058 | | ($($ty:ty),+) => {
3059 | | // Some of the $ty arguments may not actually use 'tcx
3060 | | $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `print::Print` is not general enough
... |
3072 | | };
3073 | | }
| |_- in this expansion of `forward_display_to_print!`
...
3093 | / forward_display_to_print! {
3094 | | ty::Region<'tcx>,
3095 | | Ty<'tcx>,
3096 | | &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
3097 | | ty::Const<'tcx>,
3098 | | &'tcx ty::PlaceholderType<'tcx>
3099 | | }
| |_- in this macro invocation
|
= note: `print::Print<'0, print::pretty::FmtPrinter<'a, '0>>` would have to be implemented for the type `rustc_type_ir::Placeholder<context::TyCtxt<'tcx>, BoundTy>`, for any lifetime `'0`...
= note: ...but `print::Print<'1, print::pretty::FmtPrinter<'a, 'tcx>>` is actually implemented for the type `rustc_type_ir::Placeholder<context::TyCtxt<'1>, BoundTy>`, for some specific lifetime `'1`
error: specializing impl repeats parameter `'tcx`
--> compiler/rustc_middle/src/ty/print/pretty.rs:3060:38
|
3057 | / macro_rules! forward_display_to_print {
3058 | | ($($ty:ty),+) => {
3059 | | // Some of the $ty arguments may not actually use 'tcx
3060 | | $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
... |
3072 | | };
3073 | | }
| |_- in this expansion of `forward_display_to_print!`
...
3093 | / forward_display_to_print! {
3094 | | ty::Region<'tcx>,
3095 | | Ty<'tcx>,
3096 | | &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
3097 | | ty::Const<'tcx>,
3098 | | &'tcx ty::PlaceholderType<'tcx>
3099 | | }
| |_- in this macro invocation
error[E0277]: the trait bound `&Placeholder<TyCtxt<'tcx>, BoundTy>: Lift<...>` is not satisfied
--> compiler/rustc_middle/src/ty/print/pretty.rs:3064:30
|
3057 | / macro_rules! forward_display_to_print {
3058 | | ($($ty:ty),+) => {
3059 | | // Some of the $ty arguments may not actually use 'tcx
3060 | | $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
... |
3064 | | tcx.lift(*self)
| | ---- ^^^^^ unsatisfied trait bound
| | |
| | required by a bound introduced by this call
... |
3072 | | };
3073 | | }
| |_- in this expansion of `forward_display_to_print!`
...
3093 | / forward_display_to_print! {
3094 | | ty::Region<'tcx>,
3095 | | Ty<'tcx>,
3096 | | &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
3097 | | ty::Const<'tcx>,
3098 | | &'tcx ty::PlaceholderType<'tcx>
3099 | | }
| |_- in this macro invocation
|
= help: the trait `Lift<context::TyCtxt<'_>>` is not implemented for `&rustc_type_ir::Placeholder<context::TyCtxt<'tcx>, BoundTy>`
note: required by a bound in `context::TyCtxt::<'tcx>::lift`
--> compiler/rustc_middle/src/ty/context.rs:1807:20
|
1807 | pub fn lift<T: Lift<TyCtxt<'tcx>>>(self, value: T) -> Option<T::Lifted> {
| ^^^^^^^^^^^^^^^^^^ required by this bound in `TyCtxt::<'tcx>::lift`
= note: the full name for the type has been written to '/home/jambar02/Documents/arm/rust/build/x86_64-unknown-linux-gnu/stage1-rustc/x86_64-unknown-linux-gnu/release/deps/rustc_middle-16e5c44041028d8b.long-type-3843651570422266958.txt'
= note: consider using `--verbose` to print the full type name to the console
help: consider dereferencing here
|
3064 | tcx.lift(**self)
| +
error[E0282]: type annotations needed
--> compiler/rustc_middle/src/ty/print/pretty.rs:3064:21
|
3057 | / macro_rules! forward_display_to_print {
3058 | | ($($ty:ty),+) => {
3059 | | // Some of the $ty arguments may not actually use 'tcx
3060 | | $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
... |
3064 | |/ tcx.lift(*self)
3065 | || .expect("could not lift for printing")
| ||______________________________________________________________^ cannot infer type
... |
3072 | | };
3073 | | }
| |__- in this expansion of `forward_display_to_print!`
...
3093 | / forward_display_to_print! {
3094 | | ty::Region<'tcx>,
3095 | | Ty<'tcx>,
3096 | | &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
3097 | | ty::Const<'tcx>,
3098 | | &'tcx ty::PlaceholderType<'tcx>
3099 | | }
| |_- in this macro invocation
```
</details>
```
error[E0277]: the size for values of type `(dyn Debug + 'static)` cannot be known at compilation time
--> $DIR/dyn-trait-type-alias-return-type.rs:4:11
|
LL | fn f() -> T { loop {} }
| ^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `(dyn Debug + 'static)`
note: this type alias is unsized
--> $DIR/dyn-trait-type-alias-return-type.rs:1:1
|
LL | type T = dyn core::fmt::Debug;
| ^^^^^^
= note: the return type of a function must have a statically known size
```
Use `TypingMode::PostAnalysis` in `try_evaluate_const`
As mentioned in https://github.com/rust-lang/rust/pull/148698#discussion_r2541882341, we should use ``TypingMode::PostAnalysis`` for that path.
````@BoxyUwU```` prefer the match in ``try_evaluate_const`` to be exhaustive, so I also included that in this PR :3
