Rollup of 7 pull requests
Successful merges:
- #85223 (rustdoc: Clarified the attribute which prompts the warning)
- #88847 (platform-support.md: correct ARMv7+MUSL platform triple notes)
- #88963 (Coerce const FnDefs to implement const Fn traits )
- #89376 (Fix use after drop in self-profile with llvm events)
- #89422 (Replace whitespaces in doctests' name with dashes)
- #89440 (Clarify a sentence in the documentation of Vec (#84488))
- #89441 (Normalize after substituting via `field.ty()`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Normalize after substituting via `field.ty()`
Back in https://github.com/rust-lang/rust/issues/72476 I hadn't understood where the problem was coming from, and only worked around the issue. What happens is that calling `field.ty()` on a field of a generic struct substitutes the appropriate generics but doesn't normalize the resulting type.
As a consumer of types I'm surprised that one would substitute without normalizing, feels like a footgun, so I added a comment.
Fixes https://github.com/rust-lang/rust/issues/89393.
Coerce const FnDefs to implement const Fn traits
You can now pass a FnDef to a function expecting `F` where `F: ~const FnTrait`.
r? ``@oli-obk``
``@rustbot`` label T-compiler F-const_trait_impl
Rework HIR API to make invocations of the hir_crate query harder.
`hir_crate` forces the recomputation of queries that depend on it.
This PR aims at avoiding useless invocations of `hir_crate` by making dependent code go through `tcx.hir()`.
Improve error message for `printf`-style format strings
Fixes#89173. The following is actually supported today:
```rust
fn main() {
let num = 5;
let width = 20;
print!("%*2$x", num, width);
}
```
```
error: multiple unused formatting arguments
--> src/main.rs:4:21
|
4 | print!("%*2$x", num, width);
| ------- ^^^ ^^^^^ argument never used
| || |
| || argument never used
| |help: format specifiers use curly braces: `{:1$x}`
| multiple missing formatting specifiers
|
= note: printf formatting not supported; see the documentation for `std::fmt`
```
However, as noted in #89173, something like
```rust
print!("%0*x", width, num);
```
does not give a helpful suggestion. I think this is partly intended, because there actually _is_ no Rust equivalent to this; you always have to use a positional or named argument to specify the width (instead of just using the "next" argument, as `printf` or even `.*` as a precision specifier in Rust would). Therefore, I have added a note:
```
[...]
note: format specifiers use curly braces, and you have to use a positional or named parameter for the width
--> t2.rs:4:13
|
4 | print!("%0*x", width, num);
| ^^^^
= note: printf formatting not supported; see the documentation for `std::fmt`
```
This is not perfect, but it should at least point the user in the right direction, instead of issuing no explanation at all.
cc ```@lcnr```
Cleanup lower_generics_mut and make span be the bound itself
Closes#86298 (supersedes those changes)
r? `@cjgillot` since you reviewed the other PR
(Used wrong branch for #89338)
Pick one possible lifetime in case there are multiple choices
In case a lifetime variable is created, but doesn't have an obvious lifetime in the list of named lifetimes that it should be inferred to, just pick the first one for the diagnostic.
This happens e.g. in
```rust
fn foo<'a, 'b>(a: Struct<'a>, b: Struct<'b>) -> impl Trait<'a, 'b> {
if bar() { a } else { b }
}
```
where we get a lifetime variable that combines the lifetimes of `a` and `b` creating a lifetime that is the intersection of both. Right now the type system cannot express this and thus we get an error, but that error also can't express this.
I can also create an entirely new diagnostic that mentions all involved lifetimes, so it would actually mention `'a` and `'b` instead of just `'b`.
Rebase resume argument projections during state transform
When remapping a resume argument with projections rebase them on top of
the new base.
The case where resume argument has projections is unusual, but might
arise with box syntax where the assignment is performed directly into
the box without an intermediate temporary.
Fixes#85635.
Do not suggest importing inaccessible items
Fixes#88472. For this example:
```rust
mod a {
struct Foo;
}
mod b {
type Bar = Foo;
}
```
rustc currently emits:
```
error[E0412]: cannot find type `Foo` in this scope
--> test.rs:6:16
|
6 | type Bar = Foo;
| ^^^ not found in this scope
|
help: consider importing this struct
|
6 | use a::Foo;
|
```
this is incorrect, as applying this suggestion leads to
```
error[E0603]: struct `Foo` is private
--> test.rs:6:12
|
6 | use a::Foo;
| ^^^ private struct
|
note: the struct `Foo` is defined here
--> test.rs:2:5
|
2 | struct Foo;
| ^^^^^^^^^^^
```
With my changes, I get:
```
error[E0412]: cannot find type `Foo` in this scope
--> test.rs:6:16
|
6 | type Bar = Foo;
| ^^^ not found in this scope
|
= note: this struct exists but is inaccessible:
a::Foo
```
As for the wildcard mentioned in #88472, I would argue that the warning is actually correct, since the import _is_ unused. I think the real issue is the wrong suggestion, which I have fixed here.
fix(lint): don't suggest refutable patterns to "fix" irrefutable bind
In function arguments and let bindings, do not suggest changing `C` to `Foo::C` unless `C` is the only variant of `Foo`, because it won't work.
The general warning is still kept, because code like this is confusing.
Fixes#88730
p.s. `src/test/ui/lint/lint-uppercase-variables.rs` already tests the one-variant case.
Suggest similarly named associated items in trait impls
Fix#85942
Previously, the compiler didn't suggest similarly named associated items unlike we do in many situations. This patch adds such diagnostics for associated functions, types, and constants.
Fix ICE when `start` lang item has wrong generics
In my previous pr #87875 I missed the requirements on the `start` lang item due to its relative difficulty to test and opting for more conservative estimates. This fixes that by updating the requirement to be exactly one generic type.
The `start` lang item should have exactly one generic type for the return type of the `main` fn ptr passed to it. I believe having zero would previously *sometimes* compile (often with the use of `fn() -> ()` as the fn ptr but it was likely UB to call if the return type of `main` was not `()` as far as I know) however it also sometimes would not for various errors including ICEs and LLVM errors depending on exact situations. Having more than 1 generic has always failed with an ICE because only the one generic type is expected and provided.
Fixes#79559, fixes#73584, fixes#83117 (all duplicates)
Relevant to #9307
r? ````@cjgillot````
Move encode_metadata out of CrateStore.
`rustc_metadata` is already accessible by all client crates. It does not need to be called trough a trait object.
2229: Consume IfLet expr
When using the IfLet guard feature, we can ICE when attempting to resolve PlaceBuilders.
For pattern matching, we currently don't consume the IfLet expression when "visiting" the arms leading us to not "read" all variables and hence not being able to resolve them.
r? `@nikomatsakis`
Closes https://github.com/rust-lang/rust/issues/88118
Avoid spurious "previous iteration of loop" errors
Only follow backwards edges during `get_moved_indexes` if the move path is definitely initialized at loop entry. Otherwise, the error occurred prior to the loop, so we ignore the backwards edges to avoid generating misleading "value moved here, in previous iteration of loop" errors.
This patch also slightly improves the analysis of inits, including `NonPanicPathOnly` initializations (which are ignored by `drop_flag_effects::for_location_inits`). This is required for the definite initialization analysis, but may also help find certain skipped reinits in rare cases.
Patch passes all non-ignored src/test/ui testcases.
Fixes#72649.
Constify ?-operator for Result and Option
Try to make `?`-operator usable in `const fn` with `Result` and `Option`, see #74935 . Note that the try-operator itself was constified in #87237.
TODO
* [x] Add tests for const T -> T conversions
* [x] cleanup commits
* [x] Remove `#![allow(incomplete_features)]`
* [?] Await decision in #86808 - I'm not sure
* [x] Await support for parsing `~const` in bootstrapping compiler
* [x] Tracking issue(s)? - #88674
Don't anonymize bound region names during typeck
Once this anonymization has performed, we have no
way of recovering the original names during NLL
borrow checking. Keeping the original names allows
error messages in full NLL mode to contain the original
bound region names.
As a result, the typeck results may contain types that
differ only in the names used for their bound regions. However,
anonimization of bound regions does not guarantee that
all distinct types are unqual (e.g. not subtypes of each other).
For example, `for<'a> fn(&'a u32, &'a u32)` and
`for<'b, 'c> fn(&'b u32, &'c u32)` are subtypes of each other,
as explained here:
63cc2bb3d0/compiler/rustc_infer/src/infer/nll_relate/mod.rs (L682-L690)
Therefore, any code handling types with higher-ranked regions already
needs to handle the case where two distinct `Ty`s are 'actually'
equal.
Improve help for recursion limit errors
- Tweak help message and suggested limit (handle `0` case).
- Add test for #75602 (it was already fixed, maybe can be resolved too).
Fixes#76424
Use larger span for adjustment THIR expressions
Currently, we use a relatively 'small' span for THIR
expressions generated by an 'adjustment' (e.g. an autoderef,
autoborrow, unsizing). As a result, if a borrow generated
by an adustment ends up causing a borrowcheck error, for example:
```rust
let mut my_var = String::new();
let my_ref = &my_var
my_var.push('a');
my_ref;
```
then the span for the mutable borrow may end up referring
to only the base expression (e.g. `my_var`), rather than
the method call which triggered the mutable borrow
(e.g. `my_var.push('a')`)
Due to a quirk of the MIR borrowck implementation,
this doesn't always get exposed in migration mode,
but it does in many cases.
This commit makes THIR building consistently use 'larger'
spans for adjustment expressions. These spans are recoded
when we first create the adjustment during typecheck. For
example, an autoref adjustment triggered by a method call
will record the span of the entire method call.
The intent of this change it make it clearer to users
when it's the specific way in which a variable is
used (for example, in a method call) that produdes
a borrowcheck error. For example, an error message
claiming that a 'mutable borrow occurs here' might
be confusing if it just points at a usage of a variable
(e.g. `my_var`), when no `&mut` is in sight. Pointing
at the entire expression should help to emphasize
that the method call itself is responsible for
the mutable borrow.
In several cases, this makes the `#![feature(nll)]` diagnostic
output match up exactly with the default (migration mode) output.
As a result, several `.nll.stderr` files end up getting removed
entirely.
In function arguments and let bindings, do not suggest changing `C` to `Foo::C`
unless `C` is the only variant of `Foo`, because it won't work.
The general warning is still kept, because code like this is confusing.
Fixes#88730
Rollup of 8 pull requests
Successful merges:
- #87260 (Libgccjit codegen)
- #89212 (x.py: run `rustup toolchain link` in setup)
- #89233 (Hide `<...> defined here` note if the source is not available)
- #89235 (make junit output more consistent with default format)
- #89255 (Fix incorrect disambiguation suggestion for associated items)
- #89276 (Fix the population of the `union.impls` field)
- #89283 (Add regression test for issue #83564)
- #89318 (rustc_session: Remove lint store from `Session`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add an intermediate representation to exhaustiveness checking
The exhaustiveness checking algorithm keeps deconstructing patterns into a `Constructor` and some `Fields`, but does so a bit all over the place. This PR introduces a new representation for patterns that already has that information, so we only compute it once at the start.
I find this makes code easier to follow. In particular `DeconstructedPat::specialize` is a lot simpler than what happened before, and more closely matches the description of the algorithm. I'm also hoping this could help for the project of librarifying exhaustiveness for rust_analyzer since it decouples the algorithm from `rustc_middle::Pat`.
As shown in the two test requirements that got updated, if there's other problems,
then those other problems are probably the root cause of the incorrect generics count.
Fix the population of the `union.impls` field
This pull-request fix the population of the `union.impls` field that was forgot when the `Union` type was introduce as a split from the `Struct` type https://github.com/rust-lang/rust/pull/81500.
``@rustbot`` label +T-rustdoc +A-rustdoc-json
Fix incorrect disambiguation suggestion for associated items
Fixes#88806. I have not added a new test case, because the erroneous behavior is already present in existing test cases.
