Refactor variance diagnostics to work with more types
Instead of special-casing mutable pointers/references, we
now support general generic types (currently, we handle
`ty::Ref`, `ty::RawPtr`, and `ty::Adt`)
When a `ty::Adt` is involved, we show an additional note
explaining which of the type's generic parameters is
invariant (e.g. the `T` in `Cell<T>`). Currently, we don't
explain *why* a particular generic parameter ends up becoming
invariant. In the general case, this could require printing
a long 'backtrace' of types, so doing this would be
more suitable for a follow-up PR.
We still only handle the case where our variance switches
to `ty::Invariant`.
Instead of special-casing mutable pointers/references, we
now support general generic types (currently, we handle
`ty::Ref`, `ty::RawPtr`, and `ty::Adt`)
When a `ty::Adt` is involved, we show an additional note
explaining which of the type's generic parameters is
invariant (e.g. the `T` in `Cell<T>`). Currently, we don't
explain *why* a particular generic parameter ends up becoming
invariant. In the general case, this could require printing
a long 'backtrace' of types, so doing this would be
more suitable for a follow-up PR.
We still only handle the case where our variance switches
to `ty::Invariant`.
Add codegen option for branch protection and pointer authentication on AArch64
The branch-protection codegen option enables the use of hint-space pointer
authentication code for AArch64 targets.
rustc_metadata: Encode list of all crate's traits into metadata
While working on https://github.com/rust-lang/rust/pull/88679 I noticed that rustdoc is casually doing something quite expensive, something that is used only for error reporting in rustc - collecting all traits from all crates in the dependency tree.
This PR trades some minor extra time spent by metadata encoder in rustc for major gains for rustdoc (and for rustc runs with errors, which execute the `all_traits` query for better diagnostics).
compiletest: Remove some vestigial code
The `check_lines` header is no longer parsed as a header, but instead inside the debuginfo tests. I believe this was changed in #13726.
Print space after formal generic params in fn type
Follow-up to #92238 fixing one of the FIXMEs.
```rust
macro_rules! repro {
($ty:ty) => {
stringify!($ty)
};
}
fn main() {
println!("{}", repro!(for<'a> fn(&'a u8)));
}
```
Before: `for<'a>fn(&'a u8)`
After: `for<'a> fn(&'a u8)`
The pretty printer's `print_formal_generic_params` already prints formal generic params correctly with a space, we just need to call it when printing BareFn types instead of reimplementing the printing incorrectly without a space.
83b15bfe1c/compiler/rustc_ast_pretty/src/pprust/state.rs (L1394-L1400)
Visit expressions in-order when resolving pattern bindings
[edited:] Visit the pattern's sub-expressions before defining any bindings.
Otherwise, we might get into a case where a Lit/Range expression in a pattern has a qpath pointing to a Ident pattern that is defined after it, causing an ICE when lowering to HIR. I have a more detailed explanation in the issue linked.
Fixes#92100
Parse and suggest moving where clauses after equals for type aliases
~Mostly the same as #90076, but doesn't make any syntax changes.~ Whether or not we want to land the syntax changes, we should parse the invalid where clause position and suggest moving.
r? `@nikomatsakis`
cc `@petrochenkov` you might have thoughts on implementation
rustdoc: Only special case struct fields for intra-doc links, not enum variants
Variants are already handled by `resolve_str_path_error`, rustdoc doesn't need to consider them separately. Thanks `@camelid` for catching this!
Eventually I'd like to fix the "combine this with `variant_field`" comment but that needs `resolve_field` to take a `ty_res` parameter to avoid it being super hacky (cc https://github.com/rust-lang/rust/issues/83761#issuecomment-813026026).
r? `@camelid`
rustdoc: Remove `String` allocation in iteration in `print_generic_bounds`
(I realized only after making the commit that maybe I shouldn't refer to iteration as looping, but it's close enough)
The string representation of a `clean::GenericBound` instance (evaluated [here](https://github.com/rust-lang/rust/blob/master/src/librustdoc/html/format.rs#L397)) is deterministic for a given `self` (the instance), `cx` and `f`, and since `cx` and `f` are constant (as far as I can tell) for a given invocation of `print_generic_bounds`, `self` is the determining factor. Therefore, using the data in `self` shouldn't differ in effect from using its string representation.
Given the totality of the function calls needed to evaluate the string representation as well as the actual allocation, at the very least, this shouldn't negatively affect performance.
This issue was fixed using a hacky recursion "fuel" argument, but the
issue was never minimized nor was a regression test added. The
underlying bug is still unfixed, so this test should help with fixing it
and removing the `recurse` hack.
Tighten span when suggesting lifetime on path
This is kind of a hack.
Really the issue here is that we want to suggest the segment's span if the path resolves to something defined outside of the macro, and the macro's span if it resolves to something defined within.. I'll look into seeing if we can do something like that.
Fixes#92324
r? `@cjgillot`
Add a test suite for stringify macro
This attempts to cover the behavior of `stringify!` on various interpolated syntax tree nodes.
The pretty printer has a history of unsightly whitespace (double spaces, missing spaces, spaces where there shouldn't be spaces) — #91437, #91562, #91568. There are several such issues left; the test cases that I consider to be currently behaving incorrectly are marked with `// FIXME` in the PR.
Remove VCVARS_BAT
This environment variable is no longer used. It was used in the original Azure Pipelines configuration (#60777). When GitHub Actions were added (#70190), it was no longer used, and I suspect it was just an oversight while transitioning the configuration.
Now the only two crate-public items are `build_index` and
`get_index_search_type` (because for some reason the latter is also used
in `formats::cache`).
It was previously defined in `render::search_index` but wasn't used at
all there. `clean::types` seems like a better fit since that's where
`ExternalCrate` is defined.
This is a step in the direction of computing the links more lazily,
which I think will simplify the implementation of intra-doc links.
This will also make it easier to eventually use the actual `Res` for
associated items, enum variants, and fields, rather than their HTML
page's `Res`.
Add test cases for issue #26186Closes#26186
It seems that issue #26186 has been solved at some point since the issue has been last updated. I've merged together the examples that were supplied by `@Osspial,` `@Mark-Simulacrum,` `@Diggsey,` `@eefriedman` and `@shepmaster,` so that we can add this to the testing suite and prevent these issues from re-occurring.
Relax priv-in-pub lint on generic bounds and where clauses of trait impls.
The priv-in-pub lint is a legacy mechanism of the compiler, supplanted by a reachability-based [type privacy](https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md) analysis. This PR does **not** relax type privacy; it only relaxes the lint (as proposed by the type privacy RFC) in the case of trait impls.
## Current Behavior
On public trait impls, it's currently an **error** to have a `where` bound constraining a private type with a trait:
```rust
pub trait Trait {}
pub struct Type {}
struct Priv {}
impl Trait for Priv {}
impl Trait for Type
where
Priv: Trait // ERROR
{}
```
...and it's a **warning** to have have a public type constrained by a private trait:
```rust
pub trait Trait {}
pub struct Type {}
pub struct Pub {}
trait Priv {}
impl Priv for Pub {}
impl Trait for Type
where
Pub: Priv // WARNING
{}
```
This lint applies to `where` clauses in other contexts, too; e.g. on free functions:
```rust
struct Priv<T>(T);
pub trait Pub {}
impl<T: Pub> Pub for Priv<T> {}
pub fn function<T>()
where
Priv<T>: Pub // WARNING
{}
```
**These constraints could be relaxed without issue.**
## New Behavior
This lint is relaxed for `where` clauses on trait impls, such that it's okay to have a `where` bound constraining a private type with a trait:
```rust
pub trait Trait {}
pub struct Type {}
struct Priv {}
impl Trait for Priv {}
impl Trait for Type
where
Priv: Trait // OK
{}
```
...and it's okay to have a public type constrained by a private trait:
```rust
pub trait Trait {}
pub struct Type {}
pub struct Pub {}
trait Priv {}
impl Priv for Pub {}
impl Trait for Type
where
Pub: Priv // OK
{}
```
## Rationale
While the priv-in-pub lint is not essential for soundness, it *can* help programmers avoid pitfalls that would make their libraries difficult to use by others. For instance, such a lint *is* useful for free functions; e.g. if a downstream crate tries to call the `function` in the previous snippet in a generic context:
```rust
fn callsite<T>()
where
Priv<T>: Pub // ERROR: omitting this bound is a compile error, but including it is too
{
function::<T>()
}
```
...it cannot do so without repeating `function`'s `where` bound, which we cannot do because `Priv` is out-of-scope. A lint for this case is arguably helpful.
However, this same reasoning **doesn't** hold for trait impls. To call an unconstrained method on a public trait impl with private bounds, you don't need to forward those private bounds, you can forward the public trait:
```rust
mod upstream {
pub trait Trait {
fn method(&self) {}
}
pub struct Type<T>(T);
pub struct Pub<T>(T);
trait Priv {}
impl<T: Priv> Priv for Pub<T> {}
impl<T> Trait for Type<T>
where
Pub<T>: Priv // WARNING
{}
}
mod downstream {
use super::upstream::*;
fn function<T>(value: Type<T>)
where
Type<T>: Trait // <- no private deets!
{
value.method();
}
}
```
**This PR only eliminates the lint on trait impls.** It leaves it intact for all other contexts, including trait definitions, inherent impls, and function definitions. It doesn't need to exist in those cases either, but I figured I'd first target a case where it's mostly pointless.
## Other Notes
- See discussion [on zulip](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/relax.20priv-in-pub.20lint.20for.20trait.20impl.20.60where.60.20bounds/near/222458397).
- This PR effectively reverts #79291.
