Don't immediately error for cycles during normalization
#73452 meant some normalization cycles could be detected earlier, breaking some code.
This PR makes defers errors for normalization cycles to fulfillment, fixing said code.
Fixes#74868
r? @nikomatsakis
move const param structural match checks to wfcheck
fixes#75047fixes#74950
We currently check for structural match violations inside of `type_of`.
As we need to check the array length when checking if `[NonEq; arr_len]` is structural match, we potentially require the variance of an expression. Computing the variance requires `type_of` for all types though, resulting in a cycle error.
r? @varkor @eddyb
Doc alias checks: ensure only items appearing in search index can use it
Following the discussion in #73721, I added checks to ensure that only items appearing in the search are allowed to have doc alias.
r? @ollie27
Don't emit "is not a logical operator" error outside of associative expressions
Avoid showing this error where it doesn't make sense by not assuming
"and" and "or" were intended to mean "&&" and "||" until after we decide
to continue parsing input as an associative expression.
Note that the decision of whether or not to continue parsing input as an
associative expression doesn't actually depend on this assumption.
Fixes#75599
---
First time contributor! Let me know if there are any conventions or policies I should be following that I missed here. Thanks :)
Fix clashing_extern_declarations stack overflow for recursive types.
Fixes#75512.
Adds a seen set to `structurally_same_type` to avoid recursing indefinitely for types which contain values of the same type through a pointer or reference.
Avoid showing this error where it doesn't make sense by not assuming
"and" and "or" were intended to mean "&&" and "||" until after we decide
to continue parsing input as an associative expression.
Note that the decision of whether or not to continue parsing input as an
associative expression doesn't actually depend on this assumption.
Fixes#75599
It has been deny_by_default since 2017 (and warned for some time
before that), so it seems reasonable to promote it.
The specific technical motivation to do this now is to remove a field
from `ParseSess` -- it is a global state, and global state makes
extracting libraries annoying.
Closes#40107
Add explanation for `&mut self` method call when expecting `-> Self`
When a user tries to use a method as if it returned a new value of the
same type as its receiver, we will emit a type error. Try to detect this
and provide extra explanation that the method modifies the receiver
in-place.
This has confused people in the wild, like in
https://users.rust-lang.org/t/newbie-why-the-commented-line-stops-the-snippet-from-compiling/47322
Allowing raw ptr dereference in const fn
Reflect on issue #75340
Discussion in previous PR #75425
## Updates
Change `UnsafetyViolationKind::General` to `UnsafetyViolationKind::GeneralAndConstFn` in check_unsafety.rs
Remove `unsafe` in min_const_fn_unsafe_bad.rs
Bless min_const_fn
Add the test case from issue 75340
***
Sorry for the chaos. I messed up and ended up deleting the repo in the last PR. I have to create a new PR for the new repo. I will make a feature branch next time. I will edit the old PR once I receive the commends.
@RalfJung Thank you all for your replies. They are helpful!
r? @oli-obk
Reference lang items during AST lowering
Fixes#60607 and fixes#61019.
This PR introduces `QPath::LangItem` to the HIR and uses it in AST lowering instead of constructing a `hir::Path` from a slice of symbols:
- Credit for much of this work goes to @matthewjasper, I basically just [rebased their earlier work](a227c706b7 (diff-c0f791ead38d2d02916faaad0f56f41d)).
- ~~Changes to Clippy might not be correct, they compile but attempting to run tests through `./x.py` produced failures which appeared spurious, so I didn't run any clippy tests.~~
- Changes to save analysis might not be correct - tests pass but I don't have a lot of confidence in those changes being correct.
- I've used `GenericBounds::LangItemTrait` rather than changing `PolyTraitRef`, as suggested by @matthewjasper [in this comment](a227c706b7 (r40107992)) but I'd prefer that be left for a follow-up.
- I've split things into smaller commits fairly arbitrarily to make the diff easier to review, each commit should compile but might not pass tests until the final commit.
r? @oli-obk
cc @matthewjasper
This commit modifies polymorphization's handling of predicates so that
if any generic parameter is used in a predicate then all parameters in
that predicate are used.
Signed-off-by: David Wood <david@davidtw.co>
Change `UnsafetyViolationKind::General` to `UnsafetyViolationKind::GeneralAndConstFn` in check_unsafety.rs
Remove unsafe in min_const_fn_unsafe_bad.rs
Bless min_const_fn
Add the test case from issue 75340
Co-authored-by: lzutao <taolzu@gmail.com>
Don't visit foreign function bodies when lowering ast to hir
Previously the existence of bodies inside a foreign function block would
cause a panic in the hir `NodeCollector` during its collection of crate
bodies to compute a crate hash:
e59b08e62e/src/librustc_middle/hir/map/collector.rs (L154-L158)
The collector walks the hir tree and creates a map of hir nodes, then
attaching bodies in the crate to their owner in the map. For a code like
```rust
extern "C" {
fn f() {
fn g() {}
}
}
```
The crate bodies include the body of the function `g`. But foreign
functions cannot have bodies, and while the parser AST permits a foreign
function to have a body, the hir doesn't. This means that the body of
`f` is not present in the hir, and so neither is `g`. So when the
`NodeCollector` finishes the walking the hir, it has no record of `g`,
cannot find an owner for the body of `g` it sees in the crate bodies,
and blows up.
Why do the crate bodies include the body of `g`? The AST walker has a
need a for walking function bodies, and FFIs share the same AST node as
functions in other contexts.
There are at least two options to fix this:
- Don't unwrap the map entry for an hir node in the `NodeCollector`
- Modifier the ast->hir lowering visitor to ignore foreign function
blocks
I don't think the first is preferrable, since we want to know when we
can't find a body for an hir node that we thought had one (dropping this
information may lead to an invalid hash). So this commit implements the
second option.
Closes#74120
This commit simplifies `is_range_literal` by checking for
`QPath::LangItem` containing range-related lang items, rather than using
a heuristic.
Co-authored-by: Matthew Jasper <mjjasper1@gmail.com>
Signed-off-by: David Wood <david@davidtw.co>
This commit introduces `QPath::LangItem` to the HIR and uses it in AST
lowering instead of constructing a `hir::Path` from a slice of symbols.
This might be better for performance, but is also much cleaner as the
previous approach is fragile. In addition, it resolves a bug (#61019)
where an extern crate imported as "std" would result in the paths
created during AST lowering being resolved incorrectly (or not at all).
Co-authored-by: Matthew Jasper <mjjasper1@gmail.com>
Signed-off-by: David Wood <david@davidtw.co>
This commit adds a test for #61019 where a extern crate is imported as
`std` which results in name resolution to fail due to the uses of `std`
types introduced from lowering.
Signed-off-by: David Wood <david@davidtw.co>
polymorphize: `I` used if `T` used in `I: Foo<T>`
Fixes#75326.
This PR adjusts polymorphization's handling of predicates so that after ensuring that `T` is used in `I: Foo<T>` if `I` is used, it now ensures that `I` is used if `T` is used in `I: Foo<T>`. This is necessary to mark generic parameters that only exist in impl parameters as used - thereby avoiding symbol clashes when using the new mangling scheme.
With this PR, rustc will now fully bootstrap with polymorphization and the new symbol mangling scheme enabled - not all tests pass, but I'm not sure how much of that is the interaction of the two features, I'll be looking into that soon. All tests pass with only polymorphization enabled.
r? @lcnr (this isn't sufficiently complex that I need to add to eddy's review queue)
cc @eddyb
Recover gracefully from `struct` parse errors
Currently the parser tries to recover from finding a keyword where a field name was expected, but this causes extra knock down parse errors that are completely irrelevant. Instead, bail out early in the parsing of the field and consume the remaining tokens in the block. This can reduce output significantly.
_Improvements based on the narrative in https://fasterthanli.me/articles/i-am-a-java-csharp-c-or-cplusplus-dev-time-to-do-some-rust_
Remove most specialization use in serialization
Switching from specialization to min_specialization in the compiler made the unsoundness of how we used these traits pretty clear. This changes how the `Encodable` and `Decodable` traits work to be more friendly for types need a `TyCtxt` to deserialize.
The alternative design of having both `Encodable` and `TyEncodable` traits was considered, but doesn't really work because the following impls would conflict:
```
impl<E: Ecodable> TyEncodable for Encodable
impl<E: TyEcodable> TyEncodable for [E]
```
## How-to guide
- `Rustc(De|En)codable` is now spelled `Ty(De|En)coable` in `rustc_middle`, `Metadata(En|De)codable` in `rustc_metadata` where needed, and `(De|En)codable` everywhere else.
- Manual implementations of `(De|En)codable` shouldn't be much different.
- If you're adding a new interned type that needs to be en/decodable then the simplest thing way to handle this is:
- Have the type be a wrapper around a reference to the interned data (i.e. do what `ty::Predicate` does, and not what all of the other interned types do)
- Derive `Ty(En|De)codable` on the inner type
- Implement `Encodable<impl TyEncoder>` by forwarding to the inner type.
- Implement `Decodable<impl TyDecoder>` by decoding the inner type and then creating the wrapper around that (using the `tcx` from the decoder as needed).
cc @rust-lang/compiler for opinions on this change
r? @oli-obk
This commit adjusts polymorphization's handling of predicates so that
after ensuring that `T` is used in `I: Foo<T>` if `I` is used, it now
ensures that `I` is used if `T` is used in `I: Foo<T>`. This is
necessary to mark generic parameters that only exist in impl parameters
as used - thereby avoiding symbol clashes when using the new mangling
scheme.
Signed-off-by: David Wood <david@davidtw.co>
Do not emit E0228 when it is implied by E0106
Emit E0288 (lifetime bound for trait object cannot be deduced) only on bare trait objects. When the trait object is in the form of `&dyn Trait`, E0106 (missing lifetime specifier) will have been emitted, making the former redundant.
Emit E0288 (lifetime bound for trait object cannot be deduced) only on
bare trait objects. When the trait object is in the form of
`&dyn Trait`, E0106 (missing lifetime specifier) will have been emitted,
making the former redundant.
