Implement reborrow for closure captures
The strategy for captures is detailed here with examples: https://hackmd.io/PzxYMPY4RF-B9iH9uj9GTA
Key points:
- We only need to reborrow a capture in case of move closures.
- If we mutate something via a `&mut` we store it as a `MutBorrow`/`UniqueMuBorrow` of the path containing the `&mut`,
- Similarly, if it's read via `&` ref we just store it as a `ImmBorrow` of the path containing the `&` ref.
- If a path doesn't deref a `&mut`, `&`, then that path is captured by Move.
- If the use of a path results in a move when the closure is called, then that path is truncated before any deref and the truncated path is moved into the closure.
- In the case of non-move closure if a use of a path results in a move, then the path is truncated before any deref and the truncated path is moved into the closure.
Note that the implementation differs a bit from the document to allow for truncated path to be used in the ClosureKind analysis that happens as part of the first capture analysis pass.
Closes: https://github.com/rust-lang/project-rfc-2229/issues/31
r? ````@nikomatsakis````
Placeholder lifetime error cleanup
- Remove note of trait definition
- Avoid repeating the same self type
- Use original region names when possible
- Use this error kind more often
- Print closure signatures when they are suppose to implement `Fn*` traits
Works towards #57374
r? ```@nikomatsakis```
Fix debug information for function arguments of type &str or slice.
Issue details:
When lowering MIR to LLVM IR, the compiler decomposes every &str and slice argument into a data pointer and a usize. Then, the original argument is reconstructed from the pointer and the usize arguments in the body of the function that owns it. Since the original argument is declared in the body of a function, it should be marked as a LocalVariable instead of an ArgumentVairable. This confusion causes MSVC debuggers unable to visualize &str and slice arguments correctly. (See https://github.com/rust-lang/rust/issues/81894 for more details).
Fix details:
Making sure that the debug variable for every &str and slice argument is marked as LocalVariable instead of ArgumentVariable in computing_per_local_var_debug_info. This change has been verified on VS Code debugger, VS debugger, WinDbg and LLDB.
Fix SourceMap::start_point
`start_point` needs to return the *first* character's span, but it would
previously call `find_width_of_character_at_span` which returns the span
of the *last* character. The implementation is now fixed.
Other changes:
- Docs for start_point, end_point, find_width_of_character_at_span
updated
- Minor simplification in find_width_of_character_at_span code
Fixes#81800
Don't fail to remove files if they are missing
In the backend we may want to remove certain temporary files, but in
certain other situations these files might not be produced in the first
place. We don't exactly care about that, and the intent is really that
these files are gone after a certain point in the backend.
Here we unify the backend file removing calls to use `ensure_removed`
which will attempt to delete a file, but will not fail if it does not
exist (anymore).
The tradeoff to this approach is, of course, that we may miss instances
were we are attempting to remove files at wrong paths due to some bug –
compilation would silently succeed but the temporary files would remain
there somewhere.
Add 'consider using' message to overflowing_literals
Fixes#79744.
Ironically, the `overflowing_literals` handler for binary or hex already
had this message! You would think it would be the other way around :)
cc ```@scottmcm```
Only store a LocalDefId in some HIR nodes
Some HIR nodes are guaranteed to be HIR owners: Item, TraitItem, ImplItem, ForeignItem and MacroDef.
As a consequence, we do not need to store the `HirId`'s `local_id`, and we can directly store a `LocalDefId`.
This allows to avoid a bit of the dance with `tcx.hir().local_def_id` and `tcx.hir().local_def_id_to_hir_id` mappings.
validation: fix invalid-fn-ptr error message
https://github.com/rust-lang/rust/pull/82061 changed the code here to print an `ImmTy` instead of a `ScalarMaybeUninit`; that was an accident. So go back to printing a `ScalarMaybeUninit`.
r? ```@oli-obk```
avoid full-slicing slices
If we already have a slice, there is no need to get another full-range slice from that, just use the original.
clippy::redundant_slicing
Along the way, we also implement a handful of diagnostics improvements
and fixes, particularly with respect to the special handling of `||` in
place of `|` and when there are leading verts in function params, which
don't allow top-level or-patterns anyway.
32-bit ARM: Emit `lr` instead of `r14` when specified as an `asm!` output register.
On 32-bit ARM platforms, the register `r14` has the alias `lr`. When used as an output register in `asm!`, rustc canonicalizes the name to `r14`. LLVM only knows the register by the name `lr`, and rejects it. This changes rustc's LLVM code generation to output `lr` instead.
closes#82052
r? ``@nagisa``
const_generics: Fix incorrect ty::ParamEnv::empty() usage
Fixes#80561
Not sure if I should keep the `debug!(..)`s or not but its the second time I've needed them so they sure seem useful lol
cc ``@lcnr``
r? ``@oli-obk``
const_generics: Dont evaluate array length const when handling errors
Fixes#79518Fixes#78246
cc ````@lcnr````
This was ICE'ing because we dont pass in the correct ``ParamEnv`` which meant that there was no ``Self: Foo`` predicate to make ``Self::Assoc`` well formed which caused an ICE when trying to normalize ``Self::Assoc`` in the mir interpreter
r? ````@varkor````
Suggest to create a new `const` item if the `fn` in the array is a `const fn`
Fixes#73734. If the `fn` in the array repeat expression is a `const fn`, suggest creating a new `const` item. On nightly, suggest creating an inline `const` block. This PR also removes the `suggest_const_in_array_repeat_expressions` as it is no longer necessary.
Example:
```rust
fn main() {
// Should not compile but hint to create a new const item (stable) or an inline const block (nightly)
let strings: [String; 5] = [String::new(); 5];
println!("{:?}", strings);
}
```
Gives this error:
```
error[E0277]: the trait bound `std::string::String: std::marker::Copy` is not satisfied
--> $DIR/const-fn-in-vec.rs:3:32
|
2 | let strings: [String; 5] = [String::new(); 5];
| ^^^^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `String`
|
= note: the `Copy` trait is required because the repeated element will be copied
```
With this change, this is the error message:
```
error[E0277]: the trait bound `String: Copy` is not satisfied
--> $DIR/const-fn-in-vec.rs:3:32
|
LL | let strings: [String; 5] = [String::new(); 5];
| ^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
|
= help: moving the function call to a new `const` item will resolve the error
```
Check the result cache before the DepGraph when ensuring queries
Split out of https://github.com/rust-lang/rust/pull/70951
Calling `ensure` on already forced queries is a common operation.
Looking at the results cache first is faster than checking the DepGraph for a green node.
On 32-bit ARM platforms, the register `r14` has the alias `lr`. When used as an output register in `asm!`, rustc canonicalizes the name to `r14`. LLVM only knows the register by the name `lr`, and rejects it. This changes rustc's LLVM code generation to output `lr` instead.
The `rustc_data_structures::sync::OnceCell` is thread-safe when building
a parallel compiler. This is unnecessary for the purposes of pattern
usefulness checking. Use `!Sync` `std::lazy::OnceCell` instead.
Rollup of 11 pull requests
Successful merges:
- #80523 (#[doc(inline)] sym_generated)
- #80920 (Visit more targets when validating attributes)
- #81720 (Updated smallvec version due to RUSTSEC-2021-0003)
- #81891 ([rustdoc-json] Make `header` a vec of modifiers, and FunctionPointer consistent)
- #81912 (Implement the precise analysis pass for lint `disjoint_capture_drop_reorder`)
- #81914 (Fixing bad suggestion for `_` in `const` type when a function #81885)
- #81919 (BTreeMap: fix internal comments)
- #81927 (Add a regression test for #32498)
- #81965 (Fix MIR pretty printer for non-local DefIds)
- #82029 (Use debug log level for developer oriented logs)
- #82056 (fix ice (#82032))
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
In the backend we may want to remove certain temporary files, but in
certain other situations these files might not be produced in the first
place. We don't exactly care about that, and the intent is really that
these files are gone after a certain point in the backend.
Here we unify the backend file removing calls to use `ensure_removed`
which will attempt to delete a file, but will not fail if it does not
exist (anymore).
The tradeoff to this approach is, of course, that we may miss instances
were we are attempting to remove files at wrong paths due to some bug –
compilation would silently succeed but the temporary files would remain
there somewhere.
Use debug log level for developer oriented logs
The information logged here is of limited general interest, while at the
same times makes it impractical to simply enable logging and share the
resulting logs due to the amount of the output produced.
Reduce log level from info to debug for developer oriented information.
For example, when building cargo, this reduces the amount of logs
generated by `RUSTC_LOG=info cargo build` from 265 MB to 79 MB.
Continuation of changes from 81350.
Fix MIR pretty printer for non-local DefIds
Tries to fix#81200 -- the reproducer in the issue is not fixed yet.
Submitting PR to get feedback.
r? oli-obk
Fixing bad suggestion for `_` in `const` type when a function #81885Closes#81885
```
error[E0121]: the type placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item_help.rs:13:22
|
LL | const TEST4: fn() -> _ = 42;
| ^
| |
| not allowed in type signatures
| help: use type parameters instead: `T`
```
Do not show the suggestion `help: use type parameters instead: T` when `fn`
Implement the precise analysis pass for lint `disjoint_capture_drop_reorder`
The precision pass for the lint prevents the lint from triggering for a variable (that was previously entirely captured by the closure) if all paths that need Drop starting at root variable have been captured by the closure.
r? `@nikomatsakis`
Updated smallvec version due to RUSTSEC-2021-0003
Hi.
Updated Cargo.toml's for smallvec due to RUSTSEC-2021-0003 and Cargo.toml in separate commit.
Affected function `SmallVec::insert_many` looks like don't was used directly in rust, but can be somewhere in deps.
There should be some mechanism to not to do this kind of things manually, like dependabot. Actually, dependabot supports rust and can check security articles (at least that noted in description).
Visit more targets when validating attributes
This begins to address #80048, allowing for additional validation of attributes.
There are more refactorings that can be done, though I think they should be tackled in additional PRs:
* ICE when a builtin attribute is encountered that is not checked
* Move some of the attr checking done `ast_validation` into `rustc_passes`
* note that this requires a bit of additional refactoring, especially of extern items which currently parse attributes (and thus are a part of the AST) but do not possess attributes in their HIR representation.
* Rename `Target` to `AttributeTarget`
* Refactor attribute validation completely to go through `Visitor::visit_attribute`.
* This would require at a minimum passing `Target` into this method which might be too big of a refactoring to be worth it.
* It's also likely not possible to do all the validation this way as some validation requires knowing what other attributes a target has.
r? `@davidtwco`
#[doc(inline)] sym_generated
Manually doc-inlines `rustc_span::sym_generated` into `sym`.
Previously the docs would not get inlined, causing the symbols to be undocumented as `sym_generated` is private.
r? `@jyn514`
