const_generics: correctly deal with bound variables
removes the hack in `resolve` which was needed because we evaluated constants without caring about their bound variables.
Each commit should be fairly self-contained, even if they build on each other
r? `@jackh726`
This commit removes the allows rules for the SessionDiagnostic lint
that were being used in the session.rs file.
Thanks to the PR #101230 we do not need to annotate the methods with
the allow rule as they are part of the diagnostic machinery.
rustc: Parameterize `ty::Visibility` over used ID
It allows using `LocalDefId` instead of `DefId` when possible, and also encode cheaper `Visibility<DefIndex>` into metadata.
Debuginfo line information for macro invocations are collapsed by
default - line information are replaced by the line of the outermost
expansion site. Using `-Zdebug-macros` disables this behaviour.
When the `collapse_debuginfo` feature is enabled, the default behaviour
is reversed so that debuginfo is not collapsed by default. In addition,
the `#[collapse_debuginfo]` attribute is available and can be applied to
macro definitions which will then have their line information collapsed.
Signed-off-by: David Wood <david.wood@huawei.com>
- Add a new `rustc_query_names` macro. This allows a much simpler syntax for the matchers in the macros passed to it as a callback.
- Convert `define_dep_nodes` and `alloc_once` to use `rustc_query_names`. This is possible because they only use the names
(despite the quite complicated matchers in `define_dep_nodes`, none of the other arguments are used).
- Get rid of `rustc_dep_node_append`.
- Add a `HandleCycleError` enum to rustc_query_system, along with a `handle_cycle_error` function
- Move `Value` to rustc_query_system, so `handle_cycle_error` can use it
- Move the `Value` impls from rustc_query_impl to rustc_middle. This is necessary due to orphan rules.
`BindingAnnotation` refactor
* `ast::BindingMode` is deleted and replaced with `hir::BindingAnnotation` (which is moved to `ast`)
* `BindingAnnotation` is changed from an enum to a tuple struct e.g. `BindingAnnotation(ByRef::No, Mutability::Mut)`
* Associated constants added for convenience `BindingAnnotation::{NONE, REF, MUT, REF_MUT}`
One goal is to make it more clear that `BindingAnnotation` merely represents syntax `ref mut` and not the actual binding mode. This was especially confusing since we had `ast::BindingMode`->`hir::BindingAnnotation`->`thir::BindingMode`.
I wish there were more symmetry between `ByRef` and `Mutability` (variant) naming (maybe `Mutable::Yes`?), and I also don't love how long the name `BindingAnnotation` is, but this seems like the best compromise. Ideas welcome.
[drop tracking] Use parent expression for scope, not parent node
Previously we were just using the parent node as the scope for a temporary value, but it turns out this is too narrow. For example, in an expression like
Foo {
b: &42,
a: async { 0 }.await,
}
the scope for the &42 was set to the ExprField node for `b: &42`, when we actually want to use the Foo struct expression.
We fix this by recursively searching through parent nodes until we find a Node::Expr. It may be that we don't find one, and if so that's okay, we will just fall back on the enclosing temporary scope which is always sufficient.
Helps with #97331
r? ``@jyn514``
- Parameterize DepKindStruct over `'tcx`
This allows passing in an invariant function pointer in `query_callback`,
rather than having to try and make it work for any lifetime.
- Add a new `execute_query` function to `QueryDescription` so we can call `tcx.$name` without needing to be in a macro context
`thir::Pat::kind` is a `Box<PatKind>`, which doesn't follow the usual
pattern in AST/HIR/THIR which is that the "kind" enum for a node is
stored inline within the parent struct.
This commit makes the `PatKind` directly inline within the `Pat`. This
requires using `Box<Pat>` in all the types that hold a `Pat.
Ideally, `Pat` would be stored in `Thir` like `Expr` and `Stmt` and
referred to with a `PatId` rather than `Box<Pat>`. But this is hard to
do because lots of `Pat`s get created after the destruction of the `Cx`
that does normal THIR building. But this does get us a step closer to
`PatId`, because all the `Box<Pat>` occurrences would be replaced with
`PatId` if `PatId` ever happened.
At 128 bytes, `Pat` is large. Subsequent commits will shrink it.
Remove EntryKind from metadata.
This PR continues the refactor of metadata emission to be more systematic, iterating on definitions and filtering based on each definition's `DefKind`. This allows to remove the large `EntryKind` enum, replaced by linear tables in metadata.
Replace `rustc_data_structures::thin_vec::ThinVec` with `thin_vec::ThinVec`
`rustc_data_structures::thin_vec::ThinVec` looks like this:
```
pub struct ThinVec<T>(Option<Box<Vec<T>>>);
```
It's just a zero word if the vector is empty, but requires two
allocations if it is non-empty. So it's only usable in cases where the
vector is empty most of the time.
This commit removes it in favour of `thin_vec::ThinVec`, which is also
word-sized, but stores the length and capacity in the same allocation as
the elements. It's good in a wider variety of situation, e.g. in enum
variants where the vector is usually/always non-empty.
The commit also:
- Sorts some `Cargo.toml` dependency lists, to make additions easier.
- Sorts some `use` item lists, to make additions easier.
- Changes `clean_trait_ref_with_bindings` to take a
`ThinVec<TypeBinding>` rather than a `&[TypeBinding]`, because this
avoid some unnecessary allocations.
r? `@spastorino`
Fix a bunch of typo
This PR will fix some typos detected by [typos].
I only picked the ones I was sure were spelling errors to fix, mostly in
the comments.
[typos]: https://github.com/crate-ci/typos
Migrate rustc_monomorphize to use SessionDiagnostic
### Description
- Migrates diagnostics in `rustc_monomorphize` to use `SessionDiagnostic`
- Adds an `impl IntoDiagnosticArg for PathBuf`
### TODO / Help!
- [x] I'm having trouble figuring out how to apply an optional note. 😕 Help!?
- Resolved. It was bad docs. Fixed in https://github.com/rust-lang/rustc-dev-guide/pull/1437/files
- [x] `errors:RecursionLimit` should be `#[fatal ...]`, but that doesn't exist so it's `#[error ...]` at the moment.
- Maybe I can switch after this is merged in? --> https://github.com/rust-lang/rust/pull/100694
- Or maybe I need to manually implement `SessionDiagnostic` instead of deriving it?
- [x] How does one go about converting an error inside of [a call to struct_span_lint_hir](8064a49508/compiler/rustc_monomorphize/src/collector.rs (L917-L927))?
- [x] ~What placeholder do you use in the fluent template to refer to the value in a vector? It seems like [this code](0b79f758c9/compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs (L83-L114)) ought to have the answer (or something near it)...but I can't figure it out.~ You can't. Punted.
This PR will fix some typos detected by [typos].
I only picked the ones I was sure were spelling errors to fix, mostly in
the comments.
[typos]: https://github.com/crate-ci/typos
Make call suggestions more general and more accurate
Cleans up some suggestions that have to do with adding `()` to make typeck happy.
1. Drive-by rename of `expr_t` to `base_ty` since it's the type of the `base_expr`
1. Autoderef until we get to a callable type in `suggest_fn_call`.
1. Don't erroneously suggest calling constructor when a method/field does not exist on it.
1. Suggest calling a method receiver if its function output has a method (e.g. `fn.method()` => `fn().method()`)
1. Extend call suggestions to type parameters, fn pointers, trait objects where possible
1. Suggest calling in operators too (fixes#101054)
1. Use `/* {ty} */` as argument placeholder instead of just `_`, which is confusing and makes suggestions look less like `if let` syntax.
Rework definition of MIR phases to more closely reflect semantic concerns
Implements most of rust-lang/compiler-team#522 .
I tried my best to restrict this PR to the "core" parts of the MCP. In other words, this includes just enough changes to make the new definition of `MirPhase` make sense. That means there are a couple of FIXMEs lying around. Depending on what reviewers prefer, I can either fix them in this PR or send follow up PRs. There are also a couple other refactorings of the `rustc_mir_transform/src/lib.rs` file that I want to do in follow ups that I didn't leave explicit FIXMEs for.
Display raw pointer as *{mut,const} T instead of *-ptr in errors
The `*-ptr` is rather confusing, and we have the full information for properly displaying the information.
Rollup of 9 pull requests
Successful merges:
- #95376 (Add `vec::Drain{,Filter}::keep_rest`)
- #100092 (Fall back when relating two opaques by substs in MIR typeck)
- #101019 (Suggest returning closure as `impl Fn`)
- #101022 (Erase late bound regions before comparing types in `suggest_dereferences`)
- #101101 (interpret: make read-pointer-as-bytes a CTFE-only error with extra information)
- #101123 (Remove `register_attr` feature)
- #101175 (Don't --bless in pre-push hook)
- #101176 (rustdoc: remove unused CSS selectors for `.table-display`)
- #101180 (Add another MaybeUninit array test with const)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
interpret: make read-pointer-as-bytes a CTFE-only error with extra information
Next step in the reaction to https://github.com/rust-lang/rust/issues/99923. Also teaches Miri to implicitly strip provenance in more situations when transmuting pointers to integers, which fixes https://github.com/rust-lang/miri/issues/2456.
Pointer-to-int transmutation during CTFE now produces a message like this:
```
= help: this code performed an operation that depends on the underlying bytes representing a pointer
= help: the absolute address of a pointer is not known at compile-time, so such operations are not supported
```
r? ``@oli-obk``
Revert let_chains stabilization
This is the revert against master, the beta revert was already done in #100538.
Bumps the stage0 compiler which already has it reverted.
Remove separate indexing of early-bound regions
~Based on https://github.com/rust-lang/rust/pull/99728.~
This PR copies some modifications from https://github.com/rust-lang/rust/pull/97839 around object lifetime defaults.
These modifications allow to stop counting generic parameters during lifetime resolution, and rely on the indexing given by `rustc_typeck::collect`.
`rustc_data_structures::thin_vec::ThinVec` looks like this:
```
pub struct ThinVec<T>(Option<Box<Vec<T>>>);
```
It's just a zero word if the vector is empty, but requires two
allocations if it is non-empty. So it's only usable in cases where the
vector is empty most of the time.
This commit removes it in favour of `thin_vec::ThinVec`, which is also
word-sized, but stores the length and capacity in the same allocation as
the elements. It's good in a wider variety of situation, e.g. in enum
variants where the vector is usually/always non-empty.
The commit also:
- Sorts some `Cargo.toml` dependency lists, to make additions easier.
- Sorts some `use` item lists, to make additions easier.
- Changes `clean_trait_ref_with_bindings` to take a
`ThinVec<TypeBinding>` rather than a `&[TypeBinding]`, because this
avoid some unnecessary allocations.
Replace `Body::basic_blocks()` with field access
Since the refactoring in #98930, it is possible to borrow the basic blocks
independently from other parts of MIR by accessing the `basic_blocks` field
directly.
Replace unnecessary `Body::basic_blocks()` method with a direct field access,
which has an additional benefit of borrowing the basic blocks only.
Simplify the arguments to macros generated by the `rustc_queries` proc macro
Very small cleanup. Based on https://github.com/rust-lang/rust/pull/100436 which modifies some of the same code.
r? `@cjgillot`
Implementation of import_name_type
Fixes#96534 by implementing https://github.com/rust-lang/compiler-team/issues/525
Symbols that are exported or imported from a binary on 32bit x86 Windows can be named in four separate ways, corresponding to the [import name types](https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#import-name-type) from the PE-COFF spec. The exporting and importing binaries must use the same name encoding, otherwise mismatches can lead to link failures due to "missing symbols" or to 0xc0000139 (`STATUS_ENTRYPOINT_NOT_FOUND`) errors when the executable/library is loaded. For details, see the comments on the raw-dylib feature's https://github.com/rust-lang/rust/issues/58713. To generate the correct import libraries for these DLLs, therefore, rustc must know the import name type for each `extern` function, and there is currently no way for users to provide this information.
This change adds a new `MetaNameValueStr` key to the `#[link]` attribute called `import_name_type`, and which accepts one of three values: `decorated`, `noprefix`, and `undecorated`.
A single DLL is likely to export all its functions using the same import type name, hence `import_name_type` is a parameter of `#[link]` rather than being its own attribute that is applied per-function. It is possible to have a single DLL that exports different functions using different import name types, but users could express such cases by providing multiple export blocks for the same DLL, each with a different import name type.
Note: there is a fourth import name type defined in the PE-COFF spec, `IMPORT_ORDINAL`. This case is already handled by the `#[link_ordinal]` attribute. While it could be merged into `import_type_name`, that would not make sense as `#[link_ordinal]` provides per-function information (namely the ordinal itself).
Design decisions (these match the MCP linked above):
* For GNU, `decorated` matches the PE Spec and MSVC rather than the default behavior of `dlltool` (i.e., there will be a leading `_` for `stdcall`).
* If `import_name_type` is not present, we will keep our current behavior of matching the environment (MSVC vs GNU) default for decorating.
* Using `import_name_type` on architectures other than 32bit x86 will result in an error.
* Using `import_name_type` with link kinds other than `"raw-dylib"` will result in an error.
interpret: remove support for uninitialized scalars
With Miri no longer supporting `-Zmiri-allow-uninit-numbers`, we no longer need to support storing uninit data in a `Scalar`. We anyway already only use this representation for types with *initialized* `Scalar` layout (and we have to, due to partial initialization), so let's get rid of the `ScalarMaybeUninit` type entirely.
I tried to stage this into meaningful commits, but the one that changes `read_immediate` to always trigger UB on uninit is the largest chunk of the PR and I don't see how it could be subdivided.
Fixes https://github.com/rust-lang/miri/issues/2187
r? `@oli-obk`
Elaborate all box dereferences in `ElaborateBoxDerefs`
so that it is the only pass responsible for elaboration, instead of
splitting this responsibility between the `StateTransform` and
`ElaborateBoxDerefs`.
add `depth_limit` in `QueryVTable` to avoid entering a new tcx in `layout_of`
Fixes#49735
Updates #48685
The `layout_of` query needs to check whether it overflows the depth limit, and the current implementation needs to create a new `ImplicitCtxt` inside `layout_of`. However, `start_query` will already create a new `ImplicitCtxt`, so we can check the depth limit in `start_query`.
We can tell whether we need to check the depth limit simply by whether the return value of `to_debug_str` of the query is `layout_of`. But I think adding the `depth_limit` field in `QueryVTable` may be more elegant and more scalable.
Elide superfluous storage markers
Follow the existing strategy of omitting the storage markers for temporaries
introduced for internal usage when elaborating derefs and deref projections.
Those temporaries are simple scalars which are used immediately after being
defined and never have their address taken. There is no benefit from storage
markers from either liveness analysis or code generation perspective.
- Disallow multiple macros callbacks in the same invocation. In practice, this was never used.
- Remove the `[]` brackets around the macro name
- Require an `ident`, not an arbitrary `tt`
implied bounds: explicitly state which types are assumed to be wf
Adds a new query which maps each definition to the types which that definition assumes to be well formed. The intent is to make it easier to reason about implied bounds.
This change should not influence the user-facing behavior of rustc. Notably, `borrowck` still only assumes that the function signature of associated functions is well formed while `wfcheck` assumes that the both the function signature and the impl trait ref is well formed. Not sure if that by itself can trigger UB or whether it's just annoying.
As a next step, we can add `WellFormed` predicates to `predicates_of` of these items and can stop adding the wf bounds at each place which uses them. I also intend to move the computation from `assumed_wf_types` to `implied_bounds` into the `param_env` computation. This requires me to take a deeper look at `compare_predicate_entailment` which is currently somewhat weird wrt implied bounds so I am not touching this here.
r? `@nikomatsakis`
Make `same_type_modulo_infer` a proper `TypeRelation`
Specifically, this fixes#100690 because we no longer consider a `ReLateBound` and a `ReVar` to be equal. `ReVar` can only be equal to free regions or static.
never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn)
Judging from https://github.com/rust-lang/rust/issues/71668#issuecomment-1200317370 the consensus nowadays seems to be that we should never consider an unsafe block unused if it was required with `deny(unsafe_op_in_unsafe_fn)`, no matter whether that lint is actually enabled or not. So let's adjust rustc accordingly.
The first commit does the change, the 2nd does some cleanup.
avoid assertion failures in try_to_scalar_int
Given that this is called `try_to_scalar_int`, we probably shouldn't `assert_int` here. Similarly `try_to_bits` also doesn't `assert!` that the size is correct.
Also add some `track_caller` for debugging, while we are at it.
r? ```@oli-obk```
Do not report cycle error when inferring return type for suggestion
The UI test is a good example of a case where this happens. The cycle is due to needing the value of the return type `-> _` to compute the variances of items in the crate, but then needing the variances of the items in the crate to do typechecking to infer what `-> _`'s real type is.
Since we're already gonna emit an error in astconv, just delay the cycle bug as an error.
Visit attributes in more places.
This adds 3 loosely related changes (I can split PRs if desired):
- Attribute checking on pattern struct fields.
- Attribute checking on struct expression fields.
- Lint level visiting on pattern struct fields, struct expression fields, and generic parameters.
There are still some lints which ignore lint levels in various positions. This is a consequence of how the lints themselves are implemented. For example, lint levels on associated consts don't work with `unused_braces`.
Attributes on struct expression fields were not being checked for
validity. This adds the fields as HIR nodes so that `CheckAttrVisitor`
can visit those nodes to check their attributes.
Attributes on pattern struct fields were not being checked for validity.
This adds the fields as HIR nodes so that the `CheckAttrVisitor` can
visit those nodes to check their attributes.
Stabilize backtrace
This PR stabilizes the std::backtrace module. As of #99431, the std::Error::backtrace item has been removed, and so the rest of the backtrace feature is set to be stabilized.
Previous discussion can be found in #72981, #3156.
Stabilized API summary:
```rust
pub mod std {
pub mod backtrace {
pub struct Backtrace { }
pub enum BacktraceStatus {
Unsupported,
Disabled,
Captured,
}
impl fmt::Debug for Backtrace {}
impl Backtrace {
pub fn capture() -> Backtrace;
pub fn force_capture() -> Backtrace;
pub const fn disabled() -> Backtrace;
pub fn status(&self) -> BacktraceStatus;
}
impl fmt::Display for Backtrace {}
}
}
```
`@yaahc`
consider unnormalized types for implied bounds
extracted, and slightly modified, from #98900
The idea here is that generally, rustc is split into things which can assume its inputs are well formed[^1], and things which have verify that themselves.
Generally most predicates should only deal with well formed inputs, e.g. a `&'a &'b (): Trait` predicate should be able to assume that `'b: 'a` holds. Normalization can loosen wf requirements (see #91068) and must therefore not be used in places which still have to check well formedness. The only such place should hopefully be `WellFormed` predicates
fixes#87748 and #98543
r? `@jackh726` cc `@rust-lang/types`
[^1]: These places may still encounter non-wf inputs and have to deal with them without causing an ICE as we may check for well formedness out of order.
Don't document impossible to call default trait items on impls
Closes#100176
This only skips documenting _default_ trait items on impls, not ones that are written inside the impl block. This is a conservative approach, since I think we should document all items written in an impl block (I guess unless hidden or whatever), but the existence of this new query I added makes this easy to extend to other rustdoc cases.
Implement `#[rustc_default_body_unstable]`
This PR implements a new stability attribute — `#[rustc_default_body_unstable]`.
`#[rustc_default_body_unstable]` controls the stability of default bodies in traits.
For example:
```rust
pub trait Trait {
#[rustc_default_body_unstable(feature = "feat", isssue = "none")]
fn item() {}
}
```
In order to implement `Trait` user needs to either
- implement `item` (even though it has a default implementation)
- enable `#![feature(feat)]`
This is useful in conjunction with [`#[rustc_must_implement_one_of]`](https://github.com/rust-lang/rust/pull/92164), we may want to relax requirements for a trait, for example allowing implementing either of `PartialEq::{eq, ne}`, but do so in a safe way — making implementation of only `PartialEq::ne` unstable.
r? `@Aaron1011`
cc `@nrc` (iirc you were interested in this wrt `read_buf`), `@danielhenrymantilla` (you were interested in the related `#[rustc_must_implement_one_of]`)
P.S. This is my first time working with stability attributes, so I'm not sure if I did everything right 😅
Split create_def and lowering of lifetimes for opaque types and bare async fns
r? `@cjgillot`
This work is kind of half-way, but I think it could be merged anyway.
I think we should be able to remove all the vacant arms in `new_named_lifetime_with_res`, if I'm not wrong that requires visiting more nodes. We can do that as a follow up.
In follow-up PRs, besides the thing mentioned previously, I'll be trying to remove `LifetimeCaptureContext`, `captured_lifetimes` as a global data structure, global `binders_to_ignore` and all their friends :).
Also try to remap in a more general way based on def-ids.
make `PlaceholderConst` not store the type of the const
Currently the `Placeholder` variant on `ConstKind` is 28 bytes when with this PR its 8 bytes, i am not sure this is really useful at all rn since `Unevaluated` and `Value` variants are huge still but eventually it should be possible to get both down to 16 bytes 🤔. Mostly opening this to see if this change has any perf impact when done before it can make `ConstKind`/`ConstS` smaller
Improve size assertions.
- For any file with four or more size assertions, move them into a
separate module (as is already done for `hir.rs`).
- Add some more for AST nodes and THIR nodes.
- Put the `hir.rs` ones in alphabetical order.
r? `@lqd`
Fix ICE in Definitions::create_def
`Debug` implementation for `LocalDefId` uses global `Definitions`. Normally it’s ok, but we can’t do it while holding a mutable reference to `Definitions`, since it causes ICE or deadlock (depending on whether `parallel_compiler` is enabled).
This PR effectively copies the `Debug` implementation into the problematic method. I don’t particularly love this solution (since it creates code duplication), but I don’t see any other options.
This issue was discovered when running `rustdoc` with `RUSTDOC_LOG=trace` on the following file:
```rust
pub struct SomeStruct;
fn asdf() {
impl SomeStruct {
pub fn qwop(&self) {
println!("hidden function");
}
}
}
```
I’m not sure how to create a test for this behavior.
- For any file with four or more size assertions, move them into a
separate module (as is already done for `hir.rs`).
- Add some more for AST nodes and THIR nodes.
- Put the `hir.rs` ones in alphabetical order.
Layout things
These two commits are pretty independent, but didn't seem worth doing individual PRs for:
- Always check that size is a multiple of align, even without debug assertions
- Change Layout debug printing to put `variants` last, since it often huge and not usually the part we are most interested in
Cc `@eddyb`
Fix the size of niche enums with ZST alignment
For enums with an aligned ZST variant, like `[T; 0]`, the niche layout
was not computing a sufficient size to be consistent with alignment. Now
we pad that size up to the alignment, and also make sure to only use the
niche variant's ABI when the size and alignment still match.
Fixes#99836
r? `@eddyb`
For enums with an aligned ZST variant, like `[T; 0]`, the niche layout
was not computing a sufficient size to be consistent with alignment. Now
we pad that size up to the alignment, and also make sure to only use the
niche variant's ABI when the size and alignment still match.
This initial implementation handles transmutations between types with specified layouts, except when references are involved.
Co-authored-by: Igor null <m1el.2027@gmail.com>
Deeply deny fn and raw ptrs in const generics
I think this is right -- just because we wrap a fn ptr in a wrapper type does not mean we should allow it in a const parameter.
We now reject both of these in the same way:
```
#![feature(adt_const_params)]
#[derive(Eq, PartialEq)]
struct Wrapper();
fn foo<const W: Wrapper>() {}
fn foo2<const F: fn()>() {}
```
This does regress one test (`src/test/ui/consts/refs_check_const_eq-issue-88384.stderr`), but I'm not sure it should've passed in the first place.
cc: ``@b-naber`` who introduced that test^
fixes#99641
codegen: use new {re,de,}allocator annotations in llvm
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
r? `@nikic`
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
While we're here, we also emit allocator attributes on
__rust_alloc_zeroed. This should allow LLVM to perform more
optimizations for zeroed blocks, and probably fixes#90032. [This
comment](https://github.com/rust-lang/rust/issues/24194#issuecomment-308791157)
mentions "weird UB-like behaviour with bitvec iterators in
rustc_data_structures" so we may need to back this change out if things
go wrong.
The new test cases require LLVM 15, so we copy them into LLVM
14-supporting versions, which we can delete when we drop LLVM 14.
This attribute allows to mark default body of a trait function as
unstable. This means that implementing the trait without implementing
the function will require enabling unstable feature.
This is useful in conjunction with `#[rustc_must_implement_one_of]`,
we may want to relax requirements for a trait, for example allowing
implementing either of `PartialEq::{eq, ne}`, but do so in a safe way
-- making implementation of only `PartialEq::ne` unstable.
Use full type name instead of just saying `impl Trait` in "captures lifetime" error
I think this is very useful, especially when there's >1 `impl Trait`, and it just means passing around a bit more info that we already have access to.
Slightly improve mismatched GAT where clause error
This makes the error reporting a bit more standardized between `where` on GATs and functions.
cc #99206 (`@BoxyUwU),` don't want to mark this as as "fixed" because they're still not perfect, but this is still an improvement IMO so I want to land it incrementally.
regarding "consider adding where clause to trait definition", we don't actually do that for methods as far as i can tell? i could file an issue to look into that maybe.
Simplify some code that depend on Deref
Now that we can assume #97025 works, it's safe to expect Deref is always in the first place of projections. With this, I was able to simplify some code that depended on Deref's place in projections. When we are able to move Derefer before `ElaborateDrops` successfully we will be able to optimize more places.
r? `@oli-obk`
rmeta: avoid embedding `StabilityLevel::Unstable` reason multiple times into .rmeta\.rlib files
Avoids bloating size of some rmeta\rlib files by not placing default string for `StabilityLevel::Unstable` reason multiple times, affects only stdlib\rustc artifacts. For stdlib cuts about 3% (diff of total size for patched\unpatched *.rmeta files of stage1-std) of file size, depending on crates.
fixes#88180
remove some provenance-related machine hooks that Miri no longer needs
Then we can make `scalar_to_ptr` a method on `Scalar`. :)
Fixes https://github.com/rust-lang/miri/issues/2188
r? `@oli-obk`
Fix hack that remaps env constness.
WARNING: might have perf implications.
Are there any more problems with having a constness in the `ParamEnv` now? :)
r? `@oli-obk`
Improve suggestions for returning binding
Fixes#99525
Also reworks the cause codes for match and if a bit, I think cleaning them up in a positive way.
We no longer need to call `could_remove_semicolon` in successful code, which might save a few cycles?
Fix unreachable coverage generation for inlined functions
To generate a function coverage we need at least one coverage counter,
so a coverage from unreachable blocks is retained only when some live
counters remain.
The previous implementation incorrectly retained unreachable coverage,
because it didn't account for the fact that those live counters can
belong to another function due to inlining.
Fixes#98833.
make vtable pointers entirely opaque
This implements the scheme discussed in https://github.com/rust-lang/unsafe-code-guidelines/issues/338: vtable pointers should be considered entirely opaque and not even readable by Rust code, similar to function pointers.
- We have a new kind of `GlobalAlloc` that symbolically refers to a vtable.
- Miri uses that kind of allocation when generating a vtable.
- The codegen backends, upon encountering such an allocation, call `vtable_allocation` to obtain an actually dataful allocation for this vtable.
- We need new intrinsics to obtain the size and align from a vtable (for some `ptr::metadata` APIs), since direct accesses are UB now.
I had to touch quite a bit of code that I am not very familiar with, so some of this might not make much sense...
r? `@oli-obk`
Remove the unused StableSet and StableMap types from rustc_data_structures.
The current implementation is not "stable" in the same sense that `HashStable` and `StableHasher` are stable, i.e. across compilation sessions. So, in my opinion, it's better to remove those types (which are basically unused anyway) than to give the wrong impression that these are safe for incr. comp.
I plan to provide new "stable" collection types soon that can be used to replace `FxHashMap` and `FxHashSet` in query results (see [draft](69d03ac7a7)). It's unsound that `HashMap` and `HashSet` implement `HashStable` (see https://github.com/rust-lang/rust/issues/98890 for a recent P-critical bug caused by this) -- so we should make some progress there.
Rollup of 9 pull requests
Successful merges:
- #99212 (introduce `implied_by` in `#[unstable]` attribute)
- #99352 (Use `typeck_results` to avoid duplicate `ast_ty_to_ty` call)
- #99355 (better error for bad depth parameter on macro metavar expr)
- #99480 (Diagnostic width span is not added when '0$' is used as width in format strings)
- #99488 (compiletest: Allow using revisions with debuginfo tests.)
- #99489 (rustdoc UI fixes)
- #99508 (Avoid `Symbol` to `String` conversions)
- #99510 (adapt assembly/static-relocation-model test for LLVM change)
- #99516 (Use new tracking issue for proc_macro::tracked_*.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
introduce `implied_by` in `#[unstable]` attribute
Requested by the library team [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/better.20support.20for.20partial.20stabilizations/near/285581519).
If part of a feature is stabilized and a new feature is added for the remaining parts, then the `implied_by` meta-item can be added to `#[unstable]` to indicate which now-stable feature was used previously.
```diagnostic
error: the feature `foo` has been partially stabilized since 1.62.0 and is succeeded by the feature `foobar`
--> $DIR/stability-attribute-implies-using-unstable.rs:3:12
|
LL | #![feature(foo)]
| ^^^
|
note: the lint level is defined here
--> $DIR/stability-attribute-implies-using-stable.rs:2:9
|
LL | #![deny(stable_features)]
| ^^^^^^^^^^^^^^^
help: if you are using features which are still unstable, change to using `foobar`
|
LL | #![feature(foobar)]
| ~~~~~~
help: if you are using features which are now stable, remove this line
|
LL - #![feature(foo)]
|
```
When a `#![feature(..)]` attribute still exists for the now-stable attribute, then there this has two effects:
- There will not be an stability error for uses of items from the implied feature which are still unstable (until the `#![feature(..)]` is removed or updated to the new feature).
- There will be an improved diagnostic for the remaining use of the feature attribute for the now-stable feature.
```rust
/// If part of a feature is stabilized and a new feature is added for the remaining parts,
/// then the `implied_by` attribute is used to indicate which now-stable feature previously
/// contained a item.
///
/// ```pseudo-Rust
/// #[unstable(feature = "foo", issue = "...")]
/// fn foo() {}
/// #[unstable(feature = "foo", issue = "...")]
/// fn foobar() {}
/// ```
///
/// ...becomes...
///
/// ```pseudo-Rust
/// #[stable(feature = "foo", since = "1.XX.X")]
/// fn foo() {}
/// #[unstable(feature = "foobar", issue = "...", implied_by = "foo")]
/// fn foobar() {}
/// ```
```
In the Zulip discussion, this was envisioned as `implies` on `#[stable]` but I went with `implied_by` on `#[unstable]` because it means that only the unstable attribute needs to be changed in future, not the new stable attribute, which seems less error-prone. It also isn't particularly feasible for me to detect whether items from the implied feature are used and then only suggest updating _or_ removing the `#![feature(..)]` as appropriate, so I always do both.
There's some new information in the cross-crate metadata as a result of this change, that's a little unfortunate, but without requiring that the `#[unstable]` and `#[stable]` attributes both contain the implication information, it's necessary:
```rust
/// This mapping is necessary unless both the `#[stable]` and `#[unstable]` attributes should
/// specify their implications (both `implies` and `implied_by`). If only one of the two
/// attributes do (as in the current implementation, `implied_by` in `#[unstable]`), then this
/// mapping is necessary for diagnostics. When a "unnecessary feature attribute" error is
/// reported, only the `#[stable]` attribute information is available, so the map is necessary
/// to know that the feature implies another feature. If it were reversed, and the `#[stable]`
/// attribute had an `implies` meta item, then a map would be necessary when avoiding a "use of
/// unstable feature" error for a feature that was implied.
```
I also change some comments to documentation comments in the compiler, add a helper for going from a `Span` to a `Span` for the entire line, and fix a incorrect part of the pre-existing stability attribute diagnostics.
cc `@yaahc`
interpret: rename Tag/PointerTag to Prov/Provenance
We were pretty inconsistent with calling this the "tag" vs the "provenance" of the pointer; I think we should consistently call it "provenance".
r? `@oli-obk`
Improves the diagnostic when a feature attribute is specified
unnecessarily but the feature implies another (i.e. it was partially
stabilized) to refer to the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
If part of a feature is stabilized and a new feature is added for the
remaining parts, then the `implied_by` attribute can be used to indicate
which now-stable feature previously contained a item. If the now-stable
feature is still active (if the user has only just updated rustc, for
example) then there will not be an stability error for uses of the item
from the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
Rollup of 7 pull requests
Successful merges:
- #98101 (stdlib support for Apple WatchOS)
- #99345 (Do not allow typeck children items to constrain outer RPITs)
- #99383 (Formalize defining_use_anchor)
- #99436 (Add flag to configure `noalias` on `Box<T>`)
- #99483 (Fix a numerical underflow in tuple wrap suggestion)
- #99485 (Stop injecting `#[allow(unused_qualifications)]` in generated `derive` implementations)
- #99486 (Refactor: remove a string comparison between types in `check_str_addition`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add flag to configure `noalias` on `Box<T>`
The aliasing rules of `Box<T>` are still not decided, but currently, `Box<T>` is unique and gets `noalias`. To aid making an informed decision about the future of `Box<T>`, this PR adds a flag `-Zbox-noalias` to configure `noalias` for `Box<T>` (for example, for benchmarking). The same flag already exists for `&mut T` `noalias`, where it was added because it was the problem of various miscompilations in LLVM.
For more information, see rust-lang/unsafe-code-guidelines#326
Let's avoid using two different terms for the same thing -- let's just call it "provenance" everywhere.
In Miri, provenance consists of an AllocId and an SbTag (Stacked Borrows tag), which made this even more confusing.
use `par_for_each_in` in `par_body_owners` and `collect_crate_mono_items`
Using `par_iter` in non-parallel mode will cause the entire process to abort when any iteration panics. So we can use `par_for_each_in` instead to make the error message consistent with parallel mode. This means that the compiler will output more error messages in some cases. This fixes the following ui tests when set `parallel-compiler = true`:
```
[ui] src/test\ui\privacy\privacy2.rs
[ui] src/test\ui\privacy\privacy3.rs
[ui] src/test\ui\type_length_limit.rs
```
This refers to #68171
Updates #75760
Add E0790 as more specific variant of E0283
Fixes#81701
I think this should be good to go, there are only two things where I am somewhat unsure:
- Is there a better way to get the fully-qualified path for the suggestion? I tried `self.tcx.def_path_str`, but that didn't seem to always give a correct path for the context.
- Should all this be extracted into it's own method or is it fine where it is?
r? `@estebank`
Use span_bug for unexpected field projection type
Improves the compiler error backtrace information, as shown in #99363,
by using `span_bug` instead of `bug`.
New output:
```
build/aarch64-apple-darwin/stage1/bin/rustc /tmp/test.rs --edition=2021
error: internal compiler error: compiler/rustc_middle/src/ty/closure.rs:185:25: Unexpected type Opaque(DefId(0:5 ~ test[db0f]::main::T::{opaque#0}), []) for `Field` projection
--> /tmp/test.rs:11:27
|
11 | let Foo((a, b)) = foo;
| ^^^
thread 'rustc' panicked at 'Box<dyn Any>', /Users/jmq/src/forked/rust/compiler/rustc_errors/src/lib.rs:1331:9
stack backtrace:
```
(Remainder of output truncated.)
`replace_bound_vars` fast path: check predicates, don't check consts
split out from #98900
`ty::Const` doesn't have precomputed type flags, so
computing `has_vars_bound_at_or_above` for constants
requires us to visit the const and its contained types
and constants. A noop fold should be pretty much equally as
fast so removing it prevents us from walking the constant twice
in case it contains bound vars.
r? `@jackh726`
`arena > Rc` for query results
The `Rc`s have to live for the whole duration as their count cannot go below 1 while stored as part of the query results.
By storing them in an arena we should save a bit of memory because we don't have as many independent allocations and also don't have to clone the `Rc` anymore.
Use constant eval to do strict mem::uninit/zeroed validity checks
I'm not sure about the code organisation here, I just dumped the check in rustc_const_eval at the root. Not hard to move it elsewhere, in any case.
Also, this means cranelift codegen intrinsics lose the strict checks, since they don't seem to depend on rustc_const_eval, and I didn't see a point in keeping around two copies.
I also left comments in the is_zero_valid methods about "uhhh help how do i do this", those apply to both methods equally.
Also rustc_codegen_ssa now depends on rustc_const_eval... is this okay?
Pinging `@RalfJung` since you were the one who mentioned this to me, so I'm assuming you're interested.
Haven't had a chance to run full tests on this since it's really warm, and it's 1AM, I'll check out any failures/comments in the morning :)
Revert "Highlight conflicting param-env candidates"
This reverts #98794, commit 08135254dc.
Seems to have caused an incremental compilation bug. The root cause of the incr comp bug is somewhat unrelated but is triggered by this PR, so I don't feel comfortable with having this PR in the codebase until it can be investigated further. Fixes#99233.
Allow destructuring opaque types in their defining scopes
fixes#96572
Before this PR, the following code snippet failed with an incomprehensible error, and similar code just ICEd in mir borrowck.
```rust
type T = impl Copy;
let foo: T = (1u32, 2u32);
let (a, b) = foo;
```
The problem was that the last line created MIR projections of the form `foo.0` and `foo.1`, but `foo`'s type is `T`, which doesn't have fields (only its hidden type does). But the pattern supplies enough type information (a tuple of two different inference types) to bind a hidden type.
Remove some usages of `guess_head_span`
No need to pass things through `guess_head_span` if they already point to the head span.
Only major change is that we point to the head span of `enum`s on some errors now, which I prefer.
r? `@cjgillot`
interpret: get rid of MemPlaceMeta::Poison
This is achieved by refactoring the projection code (`{mplace,place,operand}_{downcast,field,index,...}`) so that we no longer need to call `assert_mem_place` in the operand handling.
Move abstract const to middle
Moves AbstractConst (and all associated methods) to rustc middle for use in `rustc_infer`.
This allows for const resolution in infer to use abstract consts to walk consts and check if
they are resolvable.
This attempts to resolve the issue where `Foo<{ concrete const }, generic T>` is incorrectly marked as conflicting, and is independent from the other issue where nested abstract consts must be resolved.
r? `@lcnr`
`ty::Const` doesn't have precomputed type flags, so
computing `has_vars_bound_at_or_above` for constants
requires us to visit the const and its contained types
and constants. A noop fold should be pretty much equally as
fast so removing it prevents us from walking the constant twice
in case it contains bound vars.
Implement `for<>` lifetime binder for closures
This PR implements RFC 3216 ([TI](https://github.com/rust-lang/rust/issues/97362)) and allows code like the following:
```rust
let _f = for<'a, 'b> |a: &'a A, b: &'b B| -> &'b C { b.c(a) };
// ^^^^^^^^^^^--- new!
```
cc ``@Aaron1011`` ``@cjgillot``
Pull Derefer before ElaborateDrops
_Follow up work to #97025#96549#96116#95887 #95649_
This moves `Derefer` before `ElaborateDrops` and creates a new `Rvalue` called `VirtualRef` that allows us to bypass many constraints for `DerefTemp`.
r? `@oli-obk`
Lower let-else in MIR
This MR will switch to lower let-else statements in MIR building instead.
To lower let-else in MIR, we build a mini-switch two branches. One branch leads to the matching case, and the other leads to the `else` block. This arrangement will allow temporary lifetime analysis running as-is so that the temporaries are properly extended according to the same rule applied to regular `let` statements.
cc https://github.com/rust-lang/rust/issues/87335Fix#98672
don't allow ZST in ScalarInt
There are several indications that we should not ZST as a ScalarInt:
- We had two ways to have ZST valtrees, either an empty `Branch` or a `Leaf` with a ZST in it.
`ValTree::zst()` used the former, but the latter could possibly arise as well.
- Likewise, the interpreter had `Immediate::Uninit` and `Immediate::Scalar(Scalar::ZST)`.
- LLVM codegen already had to special-case ZST ScalarInt.
So I propose we stop using ScalarInt to represent ZST (which are clearly not integers). Instead, we can add new ZST variants to those types that did not have other variants which could be used for this purpose.
Based on https://github.com/rust-lang/rust/pull/98831. Only the commits starting from "don't allow ZST in ScalarInt" are new.
r? `@oli-obk`
There are several indications that we should not ZST as a ScalarInt:
- We had two ways to have ZST valtrees, either an empty `Branch` or a `Leaf` with a ZST in it.
`ValTree::zst()` used the former, but the latter could possibly arise as well.
- Likewise, the interpreter had `Immediate::Uninit` and `Immediate::Scalar(Scalar::ZST)`.
- LLVM codegen already had to special-case ZST ScalarInt.
So instead add new ZST variants to those types that did not have other variants
which could be used for this purpose.
Clarify MIR semantics of storage statements
Seems worthwhile to start closing out some of the less controversial open questions about MIR semantics. Hopefully this is fairly non-controversial - it's what we implement already, and I see no reason to do anything more restrictive. cc ``@tmiasko`` who commented on this when it was discussed in the original PR that added these docs.
Miscellaneous inlining improvements
Add `#[inline]` to a few trivial non-generic methods from a perf report
that otherwise wouldn't be candidates for inlining.
