Lint dead code in closures and generators
Fixes#108296
I think this might be a potentially breaking change, but restores the behaviour of pre-1.64.
`@rustbot` label +A-lint
Don't delay `ReError` bug during lexical region resolve
Lexical region resolution returns a list of `RegionResolutionError` which don't necessarily correspond to diagnostics being emitted. The compiler may, validly, throw away these resolution errors and do something else. Therefore it's not valid to use `ReError` during lifetime resolution, since we may actually be on a totally fine compilation path.
For example, the `implied_bounds_entailment` lint runs region resolution twice, and only emits an error if it fails both times. If we delay a bug and create a `ReError` during this first run, then we will ICE.
Fixes#108170
----
Side-note: this is conceptually equivalent to how we can't necessarily delay bugs or create `ty::Error` during trait solving/fulfillment, since the compiler is allowed to throw away these fulfillment errors to do other things. It's only once we actually emit an error (`report_region_errors` / `report_fulfillment_errors`)
Remove type-traversal trait aliases
#107924 moved the type traversal (folding and visiting) traits into the type library, but created trait aliases in `rustc_middle` to minimise both the API churn for trait consumers and the arising boilerplate. As mentioned in that PR, an alternative approach of defining subtraits with blanket implementations of the respective supertraits was also considered at that time but was ruled out as not adding much value.
Unfortunately, it has since emerged that rust-analyzer has difficulty with these trait aliases at present, resulting in a degraded contributor experience (see the recent [r-a has become useless](https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/r-a.20has.20become.20useless) topic on the #t-compiler/help Zulip stream).
This PR removes the trait aliases, and accordingly the underlying type library traits are now used directly; they are parameterised by `TyCtxt<'tcx>` rather than just the `'tcx` lifetime, and imports have been updated to reflect the fact that the trait aliases' explicitly named traits are no longer automatically brought into scope. These changes also roll-back the (no-longer required) workarounds to #107747 that were made in b409329c62.
Since this PR is just a find+replace together with the changes necessary for compilation & tidy to pass, it's currently just one mega-commit. Let me know if you'd like it broken up.
r? `@oli-obk`
`-Zlink-directives=no` will ignored `#[link]` directives while compiling a
crate, so nothing is emitted into the crate's metadata. The assumption is
that the build system already knows about the crate's native dependencies
and can provide them at link time without these directives.
This is another way to address issue # #70093, which is currently addressed
by `-Zlink-native-libraries` (implemented in #70095). The latter is
implemented at link time, which has the effect of ignoring `#[link]`
in *every* crate. This makes it a very large hammer as it requires all
native dependencies to be known to the build system to be at all usable,
including those in sysroot libraries. I think this means its effectively
unused, and definitely under-used.
Being able to control this on a crate-by-crate basis should make it much
easier to apply when needed.
I'm not sure if we need both mechanisms, but we can decide that later.
errors: generate typed identifiers in each crate
Instead of loading the Fluent resources for every crate in `rustc_error_messages`, each crate generates typed identifiers for its own diagnostics and creates a static which are pulled together in the `rustc_driver` crate and provided to the diagnostic emitter.
There are advantages and disadvantages to this change..
#### Advantages
- Changing a diagnostic now only recompiles the crate for that diagnostic and those crates that depend on it, rather than `rustc_error_messages` and all crates thereafter.
- This approach can be used to support first-party crates that want to supply translatable diagnostics (e.g. `rust-lang/thorin` in https://github.com/rust-lang/rust/pull/102612#discussion_r985372582, cc `@JhonnyBillM)`
- We can extend this a little so that tools built using rustc internals (like clippy or rustdoc) can add their own diagnostic resources (much more easily than those resources needing to be available to `rustc_error_messages`)
#### Disadvantages
- Crates can only refer to the diagnostic messages defined in the current crate (or those from dependencies), rather than all diagnostic messages.
- `rustc_driver` (or some other crate we create for this purpose) has to directly depend on *everything* that has error messages.
- It already transitively depended on all these crates.
#### Pending work
- [x] I don't know how to make `rustc_codegen_gcc`'s translated diagnostics work with this approach - because `rustc_driver` can't depend on that crate and so can't get its resources to provide to the diagnostic emission. I don't really know how the alternative codegen backends are actually wired up to the compiler at all.
- [x] Update `triagebot.toml` to track the moved FTL files.
r? `@compiler-errors`
cc #100717
Fix overlapping spans in removing extra arguments
Fixes#108225
Each span is already extended to include the previous comma, so extending to the *next* comma is unecessary and causes an ICE with assertions on.
``@rustbot`` label +A-diagnostics
Convert a hard-warning about named static lifetimes into lint "unused_lifetimes"
Fixes https://github.com/rust-lang/rust/issues/96956.
Some changes are ported from https://github.com/rust-lang/rust/pull/98079, thanks to jeremydavis519.
r? `@estebank` `@petrochenkov`
Any feedback is appreciated!
## Actions
- [x] resolve conflicts
- [x] fix build
- [x] address review comments in last pr
- [x] update tests
Extend `CodegenBackend` trait with a function returning the translation
resources from the codegen backend, which can be added to the complete
list of resources provided to the emitter.
Signed-off-by: David Wood <david.wood@huawei.com>
`run-make/translation` had some targets that weren't listed in `all` and
thus weren't being tested - the behaviour that should have been being
tested was basically correct fortunately.
Signed-off-by: David Wood <david.wood@huawei.com>
Instead of loading the Fluent resources for every crate in
`rustc_error_messages`, each crate generates typed identifiers for its
own diagnostics and creates a static which are pulled together in the
`rustc_driver` crate and provided to the diagnostic emitter.
Signed-off-by: David Wood <david.wood@huawei.com>
Define the `named_static_lifetimes` lint
This lint will replace the existing hard-warning.
Replace the named static lifetime hard-warning with the new lint
Update the UI tests for the `named_static_lifetimes` lint
Remove the direct dependency on `rustc_lint_defs`
fix build
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
use "UNUSED_LIFETIMES" instead
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
update 1 test and fix typo
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
update tests
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
fix tests: add extra blank line
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
Use DefKind to give more item kind information during BindingObligation note
The current label says "required by a bound in this". When I see that label, my immediate impression is "this... **what**?". It feels like it was cut short.
Alternative to this would be saying "in this item", but adding the item kind is strictly more informational and adds very little overhead to the existing error presentation.
Moving `create_dir_all` out of `ui-fulldeps` is complicated by the fact it sets the current directory. This means it can't be a unit test. Instead, move it to its own integration test.
Make hidden type registration opt-in, so that each site can be reviewed on its own and we have the right defaults for trait solvers
r? `@lcnr`
pulled out of https://github.com/rust-lang/rust/pull/107891 as it is the uncontroversial part
Move `Fn*` traits malformedness protections to typeck
I found it strange that we were doing a custom well-formedness check just for the `Fn*` traits' `call_*` fn items. My understanding from the git history is that this is just to avoid ICEs later on in typeck.
Well, that well-formedness check isn't even implemented correctly for `FnOnce::call_once`, or `FnMut::call_mut` for that matter. Instead, this PR just makes the typeck checks more robust, and leaves it up to the call-site to report errors when lang items are implemented in funny ways.
This coincidentally fixes another ICE where a the `Add` lang item is implemented with a `add` item that's a const instead of a method.
Add a test for default trait method with RPITITs
This didn't work in #107013, but now that #108203 has landed, let's make sure we don't regress it.
r? types
Name placeholder in some region errors
Also don't print `ReVar` or `ReLateBound` as debug... these error messages are super uncommon anyways, but in the case they do trigger, let's be slightly more helpful.
remove unstable `pick_stable_methods_before_any_unstable` flag
This flag was only added in #90329 in case there was any issue with the impl so that it would be easy to tell nightly users to use the flag to disable the new logic to fix their code. It's now been enabled for two years and also I can't find any issues corresponding to this new functionality? This flag made it way harder to understand how this code works so it would be nice to remove it and simplify what's going on.
cc `@nbdd0121`
r? `@oli-obk`
lint: don't suggest MaybeUninit::assume_init for uninhabited types
Creating a zeroed uninhabited type such as `!` or an empty enum with `mem::zeroed()` (or transmuting `()` to `!`) currently triggers this lint:
```rs
warning: the type `!` does not permit zero-initialization
--> test.rs:5:23
|
5 | let _val: ! = mem::zeroed();
| ^^^^^^^^^^^^^
| |
| this code causes undefined behavior when executed
| help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
|
= note: the `!` type has no valid value
```
The `MaybeUninit` suggestion in the help message seems confusing/useless for uninhabited types, as such a type cannot be fully initialized in the first place (as the note implies).
This PR limits this help message to inhabited types which can be initialized
Miri: basic dyn* support
As usual I am very unsure about the dynamic dispatch stuff, but it passes even the `Pin<&mut dyn* Trait>` test so that is something.
TBH I think it was a mistake to make `dyn Trait` and `dyn* Trait` part of the same `TyKind` variant. Almost everywhere in Miri this lead to the wrong default behavior, resulting in strange ICEs instead of nice "unimplemented" messages. The two types describe pretty different runtime data layout after all.
Strangely I did not need to do the equivalent of [this diff](https://github.com/rust-lang/rust/pull/106532#discussion_r1087095963) in Miri. Maybe that is because the unsizing logic matches on `ty::Dynamic(.., ty::Dyn)` already? In `unsized_info` I don't think the `target_dyn_kind` can be `DynStar`, since then it wouldn't be unsized!
r? `@oli-obk` Cc `@eholk` (dyn-star) https://github.com/rust-lang/rust/issues/102425
Refine error span for trait error into borrowed expression
Extends the error span refinement in #106477 to drill into borrowed expressions just like tuples/struct/enum literals. For example,
```rs
trait Fancy {}
trait Good {}
impl <'a, T> Fancy for &'a T where T: Good {}
impl <S> Good for Option<S> where S: Iterator {}
fn want_fancy<F>(f: F) where F: Fancy {}
fn example() {
want_fancy(&Some(5));
// (BEFORE) ^^^^^^^^ `{integer}` is not an iterator
// (AFTER) ^ `{integer}` is not an iterator
}
```
Existing heuristics try to find the right part of the expression to "point at"; current heuristics look at e.g. struct constructors and tuples. This PR adds a new check for borrowed expressions when looking into a borrowed type.
Use restricted Damerau-Levenshtein distance for diagnostics
This replaces the existing Levenshtein algorithm with the Damerau-Levenshtein algorithm. This means that "ab" to "ba" is one change (a transposition) instead of two (a deletion and insertion). More specifically, this is a _restricted_ implementation, in that "ca" to "abc" cannot be performed as "ca" → "ac" → "abc", as there is an insertion in the middle of a transposition. I believe that errors like that are sufficiently rare that it's not worth taking into account.
This was first brought up [on IRLO](https://internals.rust-lang.org/t/18227) when it was noticed that the diagnostic for `prinltn!` (transposed L and T) was `print!` and not `println!`. Only a single existing UI test was effected, with the result being an objective improvement.
~~I have left the method name and various other references to the Levenshtein algorithm untouched, as the exact manner in which the edit distance is calculated should not be relevant to the caller.~~
r? ``@estebank``
``@rustbot`` label +A-diagnostics +C-enhancement
create dummy placeholder crate to prevent compiler from panicing
This PR is to address the panic found in https://github.com/rust-lang/rust/issues/105700.
There are 2 separate things going on with this panic.
First the code could not generate a dummy response for crate fragment types when it hits the recursion limit.
This PR adds the method to the trait implementation for `DymmyResult` to be able to create a dummy crate node.
This stops the panic from happening.
The second thing that is not addressed (and maybe does not need addressing? 🤷🏻)
is that when you have multiple attributes it ends up treating attributes that follow another as being the result of expanding the former (maybe there is a better way to say that). So you end up hitting the recursion limit. Even though you would think there is no expansion happening here.
If you did not hit the recursion limit the compiler would output that `invalid_attribute` does not exists. But it currently exits before the resolution step when the recursion limit is reached here.
Including unstable lints in the lint group produces unintuitive behavior
on stable (see #106289). Meanwhile, if we only included unstable lints
on nightly and not on stable, we could end up with confusing bugs that
were hard to compare across versions of Rust that lacked code changes.
I think that only including stable lints in `rustdoc::all`, no matter
the release channel, is the most intuitive option. Users can then
control unstable lints individually, which is reasonable since they have
to enable the feature gates individually anyway.
Type-directed probing for inherent associated types
When probing for inherent associated types (IATs), equate the Self-type found in the projection with the Self-type of the relevant inherent impl blocks and check if all predicates are satisfied.
Previously, we didn't look at the Self-type or at the bounds and just picked the first inherent impl block containing an associated type with the name we were searching for which is obviously incorrect.
Regarding the implementation, I basically copied what we do during method probing (`assemble_inherent_impl_probe`, `consider_probe`). Unfortunately, I had to duplicate a lot of the diagnostic code found in `rustc_hir_typeck::method::suggest` which we don't have access to in `rustc_hir_analysis`. Not sure if there is a simple way to unify the error handling. Note that in the future, `rustc_hir_analysis::astconv` might not actually be the place where we resolve inherent associated types (see https://github.com/rust-lang/rust/pull/103621#issuecomment-1304309565) but `rustc_hir_typeck` (?) in which case the duplication may naturally just disappear. While inherent associated *constants* are currently resolved during "method" probing, I did not find a straightforward way to incorporate IAT lookup into it as types and values (functions & constants) are two separate entities for which distinct code paths are taken.
Fixes#104251 (incl. https://github.com/rust-lang/rust/issues/104251#issuecomment-1338501171).
Fixes#105305.
Fixes#107468.
`@rustbot` label T-types F-inherent_associated_types
r? types
Make codegen choose whether to emit overflow checks
ConstProp and DataflowConstProp currently have a specific code path not to propagate constants when they overflow. This is meant to have the correct behaviour when inlining from a crate with overflow checks (like `core`) into a crate compiled without.
This PR shifts the behaviour change to the `Assert(Overflow*)` MIR terminators: if the crate is compiled without overflow checks, just skip emitting the assertions. This is already what happens with `OverflowNeg`.
This allows ConstProp and DataflowConstProp to transform `CheckedBinaryOp(Add, u8::MAX, 1)` into `const (0, true)`, and let codegen ignore the `true`.
The interpreter is modified to conform to this behaviour.
Fixes#35310
Fix RPITITs in default trait methods (by assuming projection predicates in param-env)
Instead of having special projection logic that allows us to turn `ProjectionTy(RPITIT, [Self#0, ...])` into `OpaqueTy(RPITIT, [Self#0, ...])`, we can instead augment the param-env of default trait method bodies to assume these as projection predicates. This should allow us to only project where we're allowed to!
In order to make this work without introducing a bunch of cycle errors, we additionally tweak the `OpaqueTypeExpander` used by `ParamEnv::with_reveal_all_normalized` to not normalize the right-hand side of projection predicates. This should be fine, because if we use the projection predicate to normalize some other projection type, we'll continue to normalize the opaque that it gets projected to.
This also makes it possible to support default trait methods with RPITITs in an associated-type based RPITIT lowering strategy without too much extra effort.
Fixes#107002
Alternative to #108142
Correctly handle links starting with whitespace
Part of https://github.com/rust-lang/rust/issues/107995.
I just got this issue, wrote a fix and then saw the issue. So here's the PR. ^^'
r? `@petrochenkov`
Fix json reexports of different items with same name
Fixes #107677.
I renamed `from_item_id*` functions into `id_from_item` instead because it makes more sense now. I also simplified the logic around it a bit so that the `ids` function will now directly pass `&clean::Item` to `id_from_item` and the ID will be consistently generated (it caused an issue when I updated the ID for imports).
So now, the big change of this PR: I changed how imports' ID is generated: it now includes the target item's ID at the end of the ID. It's to prevent two reexported items with the same name (but different types).
r? `@aDotInTheVoid`
Rollup of 7 pull requests
Successful merges:
- #104659 (reflow the stack size story)
- #106933 (Update documentation of select_nth_unstable and select_nth_unstable_by to state O(n^2) complexity)
- #107783 (rustdoc: simplify DOM for `.item-table`)
- #107951 (resolve: Fix doc links referring to other crates when documenting proc macro crates directly)
- #108130 ("Basic usage" is redundant for there is just one example)
- #108146 (rustdoc: hide `reference` methods in search index)
- #108189 (Fix some more `non_lifetime_binders` stuff with higher-ranked trait bounds)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix some more `non_lifetime_binders` stuff with higher-ranked trait bounds
1. When assembling candidates for `for<T> T: Sized`, we can't ICE because the self-type is a bound type.
2. Fix an issue where, when canonicalizing in non-universe preserving mode, we don't actually set the universe for placeholders to the root even though we do the same for region vars.
3. Make `Placeholder("T")` format like `T` in error messages.
Fixes#108180Fixes#108182
r? types
rustdoc: simplify DOM for `.item-table`
This switches from using `<div>` to the more semantic `<ul>`, and using class names that rhyme with the classes the search results table uses.
Make `dyn*`'s value backend type a pointer
One tweak on top of Ralf's commit should fix using `usize` as a `dyn*`-coercible type, and should fix when we're using various other pointer types when LLVM opaque pointers is disabled.
r? `@eholk` but feel free to reassign
cc https://github.com/rust-lang/rust/pull/107728#issuecomment-1421231823 `@RalfJung`
Check that built-in callable types validate their output type is `Sized` (in new solver)
Working on parity with old solver. Putting this up for consideration, it's not *really* needed or anything just yet. Maybe it's better to approach this from another direction (like always checking the item bounds when calling `consider_assumption`? we may need that for coinduction to be sound though?)
This basically implements #100096 for the new solver.
