avoid generalization inside of aliases
The basic idea of this PR is that we don't generalize aliases when the instantiation could fail later on, either due to the *occurs check* or because of a universe error. We instead replace the whole alias with an inference variable and emit a nested `AliasRelate` goal. This `AliasRelate` then fully normalizes the alias before equating it with the inference variable, at which point the alias can be treated like any other rigid type.
We now treat aliases differently depending on whether they are *rigid* or not. To detect whether an alias is rigid we check whether `NormalizesTo` fails. While we already do so inside of `AliasRelate` anyways, also doing so when instantiating a query response would be both ugly/difficult and likely inefficient. To avoid that I change `instantiate_and_apply_query_response` to relate types completely structurally. This change generally removes a lot of annoying complexity, which is nice. It's implemented by adding a flag to `Equate` to change it to structurally handle aliases.
We currently always apply constraints from canonical queries right away. By providing all the necessary information to the canonical query, we can guarantee that instantiating the query response never fails, which further simplifies the implementation. This does add the invariant that *any information which could cause instantiating type variables to fail must also be available inside of the query*.
While it's acceptable for canonicalization to result in more ambiguity, we must not cause the solver to incompletely structurally relate aliases by erasing information. This means we have to be careful when merging universes during canonicalization. As we only generalize for type and const variables we have to make sure that anything nameable by such a type or const variable inside of the canonical query is also nameable outside of it. Because of this we both stop merging universes of existential variables when canonicalizing inputs, we put all uniquified regions into a higher universe which is not nameable by any type or const variable.
I will look into always replacing aliases with inference variables when generalizing in a later PR unless the alias references bound variables. This should both pretty much fix https://github.com/rust-lang/trait-system-refactor-initiative/issues/4. This may allow us to merge the universes of existential variables again by changing generalize to not consider their universe when deciding whether to generalize aliases. This requires some additional non-trivial changes to alias-relate, so I am leaving that as future work.
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/79. While it would be nice to decrement universe indices when existing a `forall`, that was surprisingly difficult and not necessary to fix this issue. I am really happy with the approach in this PR think it is the correct way forward to also fix the remaining cases of https://github.com/rust-lang/trait-system-refactor-initiative/issues/8.
Fix more #121208 fallout (round 3)
#121208 converted lots of delayed bugs to bugs. Unsurprisingly, there were a few invalid conversion found via fuzzing.
r? `@lcnr`
Don't unnecessarily change `SIGPIPE` disposition in `unix_sigpipe` tests
In `auxiliary/sigpipe-utils.rs`, all we want to know is the current `SIGPIPE` disposition. We should not change it. So use `libc::sigaction` instead of `libc::signal`. That way we can also remove the code that restores it.
Part of https://github.com/rust-lang/rust/issues/97889.
Split Diagnostics for Uncommon Codepoints: Add Individual Identifier Types
This pull request further modifies the `uncommon_codepoints` lint, adding the individual identifier types of `Technical`, `Not_NFKC`, `Exclusion` and `Limited_Use` to the diagnostic message.
Example rendered diagnostic:
```
error: identifier contains a Unicode codepoint that is not used in normalized strings: 'ij'
--> $DIR/lint-uncommon-codepoints.rs:6:4
|
LL | fn dijkstra() {}
| ^^^^^^^
= note: this character is included in the Not_NFKC Unicode general security profile
```
Second step of #120228.
Allow tests to specify a `//@ filecheck-flags:` header
This allows individual codegen/assembly/mir-opt tests to pass extra flags to the LLVM `filecheck` tool as needed.
---
The original motivation was noticing that `tests/run-make/instrument-coverage` was very close to being an ordinary codegen test, except that it needs some extra logic to set up platform-specific variables to be passed into filecheck.
I then saw the comment in `verify_with_filecheck` indicating that a `filecheck-flags` header might be useful for other purposes as well.
Always use WaitOnAddress on Win10+
`WaitOnAddress` and `WakeByAddressSingle` are always available since Windows 8 so they can now be used without needing to delay load. I've also moved the Windows 7 thread parking fallbacks into a separate sub-module.
Prevent cycle in implied predicates computation
Makes #65913 from hang -> fail. I believe fail is the correct state for this test to remain for the long term.
Stabilize `cfg_target_abi`
This stabilizes the `cfg` option called `target_abi`:
```rust
#[cfg(target_abi = "eabihf")]
```
Tracking issue: #80970fixes#78791resolves#80970
Add `#[rustc_no_mir_inline]` for standard library UB checks
should help with #121110 and also with #120848
Because the MIR inliner cannot know whether the checks are enabled or not, so inlining is an unnecessary compile time pessimization when debug assertions are disabled. LLVM knows whether they are enabled or not, so it can optimize accordingly without wasting time.
r? `@saethlin`
In `auxiliary/sigpipe-utils.rs`, all we want to know is the current
`SIGPIPE` disposition. We should not change it. So use `libc::sigaction`
instead of `libc::signal`. That way we can also remove the code that
restores it.
Ignore less tests in debug builds
Since https://github.com/rust-lang/rust/pull/120594 and https://github.com/rust-lang/rust/pull/120863, nearly all UB-detecting debug assertions get compiled out of code that is monomorphized by a crate built with debug assertions disabled.
Which means that if we default all our codegen tests to `-Cdebug-assertions=no`, most of them work just fine against a sysroot built with debug assertions.
I also tried to explain a bit better why some tests need to be skipped, for those that still need to be skipped.
Account for RPITIT in E0310 explicit lifetime constraint suggestion
When given
```rust
trait Original {
fn f() -> impl Fn();
}
trait Erased {
fn f(&self) -> Box<dyn Fn()>;
}
impl<T: Original> Erased for T {
fn f(&self) -> Box<dyn Fn()> {
Box::new(<T as Original>::f())
}
}
```
emit do not emit an invalid suggestion restricting the `Trait::{opaque}` type in a `where` clause:
```
error[E0310]: the associated type `<T as Original>::{opaque#0}` may not live long enough
--> $DIR/missing-static-bound-from-impl.rs:11:9
|
LL | Box::new(<T as Original>::f())
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| the associated type `<T as Original>::{opaque#0}` must be valid for the static lifetime...
| ...so that the type `impl Fn()` will meet its required lifetime bounds
```
Partially address #119773. Ideally we'd suggest modifying `Erased::f` instead.
r? `@compiler-errors`
Don't ICE on anonymous struct in enum variant
Fixes#121446
Computing `adt_def` for the anon struct calls `adt_def` on the parent to find its repr. If the parent is a non-item (e.g. an enum variant) we should have already emitted at least one error, so we just use the repr of the anonymous struct to avoid an ICE.
cc ``@frank-king``
mark `min_exhaustive_patterns` as complete
This is step 1 and 2 of my [proposal](https://github.com/rust-lang/rust/issues/119612#issuecomment-1918097361) to move `min_exhaustive_patterns` forward. The vast majority of in-tree use cases of `exhaustive_patterns` are covered by `min_exhaustive_patterns`. There are a few cases that still require `exhaustive_patterns` in tests and they're all behind references.
r? ``@ghost``
Allow for a missing `adt_def` in `NamePrivacyVisitor`.
This was caused by 72b172bdf6 in #121206. That commit removed an early return from `analysis` when there are stashed errors. As a result, it's possible to reach privacy analysis when there are stashed errors, which means more code paths can be reached. One such code path was handled in that commit, where a `span_bug` was changed to a `span_delayed_bug`.
This commit handles another such code path uncovered by fuzzing, in much the same way.
Fixes#121455.
r? `@oli-obk`
Fix more #121208 fallout
#121208 converted lots of delayed bugs to bugs. Unsurprisingly, there were a few invalid conversion found via fuzzing.
r? `@lcnr`
When encountering `<&T as Clone>::clone(x)` because `T: Clone`, suggest `#[derive(Clone)]`
CC #40699.
```
warning: call to `.clone()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:23:71
|
LL | let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref.clone();
| ^^^^^^^^
|
= note: the type `PlainType<u32>` does not implement `Clone`, so calling `clone` on `&PlainType<u32>` copies the reference, which does not do anything and can be removed
help: remove this redundant call
|
LL - let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref.clone();
LL + let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref;
|
help: if you meant to clone `PlainType<u32>`, implement `Clone` for it
|
LL + #[derive(Clone)]
LL | struct PlainType<T>(T);
|
```
Move as many tests from tests/ui/numbers-arithmetic to tests/ui/lint as possible
Fixes#119851 , and also consolidates as many individual tests as possible from numbers-arithmetic. I might have moved the tests in too aggressively, so let me know
Provide suggestions through `rustc_confusables` annotations
Help with common API confusion, like asking for `push` when the data structure really has `append`.
```
error[E0599]: no method named `size` found for struct `Vec<{integer}>` in the current scope
--> $DIR/rustc_confusables_std_cases.rs:17:7
|
LL | x.size();
| ^^^^
|
help: you might have meant to use `len`
|
LL | x.len();
| ~~~
help: there is a method with a similar name
|
LL | x.resize();
| ~~~~~~
```
Fix#59450 (we can open subsequent tickets for specific cases).
Fix#108437:
```
error[E0599]: `Option<{integer}>` is not an iterator
--> f101.rs:3:9
|
3 | opt.flat_map(|val| Some(val));
| ^^^^^^^^ `Option<{integer}>` is not an iterator
|
::: /home/gh-estebank/rust/library/core/src/option.rs:571:1
|
571 | pub enum Option<T> {
| ------------------ doesn't satisfy `Option<{integer}>: Iterator`
|
= note: the following trait bounds were not satisfied:
`Option<{integer}>: Iterator`
which is required by `&mut Option<{integer}>: Iterator`
help: you might have meant to use `and_then`
|
3 | opt.and_then(|val| Some(val));
| ~~~~~~~~
```
On type error of method call arguments, look at confusables for suggestion. Fix#87212:
```
error[E0308]: mismatched types
--> f101.rs:8:18
|
8 | stuff.append(Thing);
| ------ ^^^^^ expected `&mut Vec<Thing>`, found `Thing`
| |
| arguments to this method are incorrect
|
= note: expected mutable reference `&mut Vec<Thing>`
found struct `Thing`
note: method defined here
--> /home/gh-estebank/rust/library/alloc/src/vec/mod.rs:2025:12
|
2025 | pub fn append(&mut self, other: &mut Self) {
| ^^^^^^
help: you might have meant to use `push`
|
8 | stuff.push(Thing);
| ~~~~
```
This test was already very close to being an ordinary codegen test, except that
it needed some extra logic to set a few variables based on (target) platform
characteristics.
Now that we have support for `//@ filecheck-flags:`, we can instead set those
variables using the normal test revisions mechanism.
This makes room for migrating over `tests/run-make/instrument-coverage`,
without increasing the number of top-level items in the codegen test directory.
