reword "possible candidate" import suggestion
This suggestion has always read a bit awkwardly to me, particularly the "possible better candidate" variant.
This commit rewords the suggestion to be more concise and mention the kind of the suggested item. There isn't a nice way to label individual suggestions, so I opted to use "items" in the case of multiple suggestions.
use hex for pointers in Miri error messages
Also refine vtable error message: distinguish between "drop fn does not point to a function" and "drop fn points to a function with the wrong signature".
Miri validation error handling cleanup
Slightly expand @jumbatm's pattern macro and use it throughout validation. This ensures we never incorrectly swallow `InvalidProgram` errors or ICE when they occur.
Fixes https://github.com/rust-lang/rust/issues/71353
r? @oli-obk
Provide suggestions for type parameters missing bounds for associated types
When implementing the binary operator traits it is easy to forget to restrict the `Output` associated type. `rustc` now accounts for different cases to lead users in the right direction to add the necessary restrictions. The structured suggestions in the following output are new:
```
error: equality constraints are not yet supported in `where` clauses
--> $DIR/missing-bounds.rs:37:33
|
LL | impl<B: Add> Add for E<B> where <B as Add>::Output = B {
| ^^^^^^^^^^^^^^^^^^^^^^ not supported
|
= note: see issue #20041 <https://github.com/rust-lang/rust/issues/20041> for more information
help: if `Output` is an associated type you're trying to set, use the associated type binding syntax
|
LL | impl<B: Add> Add for E<B> where B: Add<Output = B> {
| ^^^^^^^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/missing-bounds.rs:11:11
|
7 | impl<B> Add for A<B> where B: Add {
| - this type parameter
...
11 | A(self.0 + rhs.0)
| ^^^^^^^^^^^^^^ expected type parameter `B`, found associated type
|
= note: expected type parameter `B`
found associated type `<B as std::ops::Add>::Output`
help: consider further restricting this bound
|
7 | impl<B> Add for A<B> where B: Add + std::ops::Add<Output = B> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
error[E0369]: cannot add `B` to `B`
--> $DIR/missing-bounds.rs:31:21
|
31 | Self(self.0 + rhs.0)
| ------ ^ ----- B
| |
| B
|
help: consider restricting type parameter `B`
|
27 | impl<B: std::ops::Add<Output = B>> Add for D<B> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
That output is given for the following cases:
```rust
struct A<B>(B);
impl<B> Add for A<B> where B: Add {
type Output = Self;
fn add(self, rhs: Self) -> Self {
A(self.0 + rhs.0) //~ ERROR mismatched types
}
}
struct D<B>(B);
impl<B> Add for D<B> {
type Output = Self;
fn add(self, rhs: Self) -> Self {
Self(self.0 + rhs.0) //~ ERROR cannot add `B` to `B`
}
}
struct E<B>(B);
impl<B: Add> Add for E<B> where <B as Add>::Output = B {
type Output = Self;
fn add(self, rhs: Self) -> Self {
Self(self.0 + rhs.0)
}
}
```
Define UB in float-to-int casts to saturate
This closes#10184 by defining the behavior there to saturate infinities and values exceeding the integral range (on the lower or upper end). `NaN` is sent to zero.
- Round to zero, and representable values cast directly.
- `NaN` goes to 0
- Values beyond the limits of the type are saturated to the "nearest value"
(essentially rounding to zero, in some sense) in the integral type, so e.g.
`f32::INFINITY` would go to `{u,i}N::MAX.`
Suggest removing semicolon in last expression only if it's type is known
Fixes#67971
Is there a syntax for explicitly checking if a note doesn't exist in test output? Something like `//~ !NOTE ...`
I believe r? @estebank deals with diagnostics.
Add Option to Force Unwind Tables
When panic != unwind, `nounwind` is added to all functions for a target.
This can cause issues when a panic happens with RUST_BACKTRACE=1, as
there needs to be a way to reconstruct the backtrace. There are three
possible sources of this information: forcing frame pointers (for which
an option exists already), debug info (for which an option exists), or
unwind tables.
Especially for embedded devices, forcing frame pointers can have code
size overheads (RISC-V sees ~10% overheads, ARM sees ~2-3% overheads).
In production code, it can be the case that debug info is not kept, so it is useful
to provide this third option, unwind tables, that users can use to
reconstruct the call stack. Reconstructing this stack is harder than
with frame pointers, but it is still possible.
---
This came up in discussion on #69890, and turned out to be a fairly simple addition.
r? @hanna-kruppe
Added MIR constant propagation of Scalars into function call arguments
Now for the function call arguments!
Caveats:
1. It's only being enabled at `mir-opt-2` or higher, because currently codegen gives performance regressions with this optimization.
2. Only propagates Scalars. Tuples and references (references are `Indirect`, right??) are not being propagated into as of this PR.
3. Maybe more tests would be nice?
4. I need (shamefully) to ask @wesleywiser to write in his words (or explain to me, and then I can write it down) why we want to ignore propagation into `ScalarPairs` and `Indirect` arguments.
r? @wesleywiser
forbid `dyn Trait` in patterns
Do not allow `&dyn Trait` as a generic const parameters.
This also changes dyn trait in pattern from ICE to error.
closes#63322closes#70972
r? @eddyb
When panic != unwind, `nounwind` is added to all functions for a target.
This can cause issues when a panic happens with RUST_BACKTRACE=1, as
there needs to be a way to reconstruct the backtrace. There are three
possible sources of this information: forcing frame pointers (for which
an option exists already), debug info (for which an option exists), or
unwind tables.
Especially for embedded devices, forcing frame pointers can have code
size overheads (RISC-V sees ~10% overheads, ARM sees ~2-3% overheads).
In code, it can be the case that debug info is not kept, so it is useful
to provide this third option, unwind tables, that users can use to
reconstruct the call stack. Reconstructing this stack is harder than
with frame pointers, but it is still possible.
This commit adds a compiler option which allows a user to force the
addition of unwind tables. Unwind tables cannot be disabled on targets
that require them for correctness, or when using `-C panic=unwind`.
On type mismatch involving associated type, suggest constraint
When an associated type is found when a specific type was expected, if
possible provide a structured suggestion constraining the associated
type in a bound.
```
error[E0271]: type mismatch resolving `<T as Foo>::Y == i32`
--> $DIR/associated-types-multiple-types-one-trait.rs:13:5
|
LL | want_y(t);
| ^^^^^^ expected `i32`, found associated type
...
LL | fn want_y<T:Foo<Y=i32>>(t: &T) { }
| ----- required by this bound in `want_y`
|
= note: expected type `i32`
found associated type `<T as Foo>::Y`
help: consider constraining the associated type `<T as Foo>::Y` to `i32`
|
LL | fn have_x_want_y<T:Foo<X=u32, Y = i32>>(t: &T)
| ^^^^^^^^^
```
```
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:12:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<impl Trait as Trait>::A`
help: consider constraining the associated type `<impl Trait as Trait>::A` to `usize`
|
LL | fn foo(x: impl Trait<A = usize>) {
| ^^^^^^^^^^
```
Fix#71035. Related to #70908.
Rollup of 4 pull requests
Successful merges:
- #71645 (Direct contributors to try stage 0 rustdoc first)
- #71801 (Correctly check comparison operator in MIR typeck)
- #71844 (List Clippy as a subtree, instead of a submodule)
- #71864 (Update link in contributing.md)
Failed merges:
r? @ghost
Correctly check comparison operator in MIR typeck
The subtyping for comparisons between pointers was reversed in MIR typeck.
There also wasn't a check that comparisons between numeric types had matching types.
