Fix regionck failure when converting Index to IndexMut
Fixes#74933
Consider an overloaded index expression `base[index]`. Without knowing whether it will be mutated, this will initially be desugared into `<U as Index<T>>::index(&base, index)` for some `U` and `T`. Let `V` be the `expr_ty_adjusted` of `index`.
If this expression ends up being used in any mutable context (or used in a function call with `&mut self` receiver before #72280), we will need to fix it up. The current code will rewrite it to `<U as IndexMut<V>>::index_mut(&mut base, index)`. In most cases this is fine as `V` will be equal to `T`, however this is not always true when `V/T` are references, as they may have different region.
This issue is quite subtle before #72280 as this code path is only used to fixup function receivers, but after #72280 we've made this a common path.
The solution is basically just rewrite it to `<U as IndexMut<T>>::index_mut(&mut base, index)`. `T` can retrieved in the fixup path using `node_substs`.
older toolchains not valid anymore
with the change to llvm 10 the parameter
LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN do not do anything as min and soft error is the same.
see 86b120e6f3/llvm/cmake/modules/CheckCompilerVersion.cmake
Reland #74069
Investigation in #74716 has concluded that this PR is indeed not a regression (and in fact the rollup itself is not either).
This reverts the revert in #74611.
r? @nnethercote cc @eddyb
Rollup of 7 pull requests
Successful merges:
- #75036 (Prefer pattern matching over indexing)
- #75378 (Introduce `rustc_lexer::is_ident` and use it in couple of places)
- #75393 (Fully handle "?" shortcut)
- #75403 (Update comment for function)
- #75407 (Requested changes to [*mut T|*const T]::set_ptr_value)
- #75408 (Update MinGW comments in ci.yml)
- #75409 (Fix range term in alloc vec doc)
Failed merges:
r? @ghost
Requested changes to [*mut T|*const T]::set_ptr_value
This is a follow-up to PR #74774 (tracking issue #75091), acting on some change requests made after approval:
- adds `#[must_use]` attribute
- changes type of `val` pointer argument from `()` to `u8`
- adjusts documentation mentioning pointer provenance
move Deaggregate pass to post_borrowck_cleanup
Reopen of #71946
Only the second commit is from this PR, the other commit is a bugfix that's in the process of getting merged. I'll rebase once that's done
In #70073 MIR pass handling got reorganized, but with the goal of not changing behavior (except for disabling some optimizations on opt-level = 0). But there we realized that the Deaggregator pass, while conceptually more of a "cleanup" pass (and one that should be run before optimizations), was run in the middle of the optimization chain. Likely this is an accident of history, so I suggest we try and clean that up by making it a proper cleanup pass.
This does change mir-opt output, because deaggregation now runs before const-prop instead of after.
r? @wesleywiser @rust-lang/wg-mir-opt
cc @RalfJung
Add sample fix for E0749
Even though the description is clear but the solution may not be as straightforward.
Adding a suggested fix from documentation side.
r? @GuillaumeGomez
However, this suggestion should be shown in rustc itself for easy fix, the documentation should also reflect on the changes in rustc. Currently,
```
error[E0749]: negative impls cannot have any items
--> test.rs:6:5
|
6 | type Foo = i32; // error!
| ^^^^^^^^^^^^^^^
error: aborting due to previous error
For more information about this error, try `rustc --explain E0749`.
```
rustc should tell the user to remove it.
Tweak conditions for E0026 and E0769
When we have a tuple struct used with struct we don't want to suggest using the (valid) struct syntax with numeric field names. Instead we want to suggest the expected syntax.
Given
```rust
fn main() {
match MyOption::MySome(42) {
MyOption::MySome { x: 42 } => (),
_ => (),
}
}
```
We now emit E0769 "tuple variant `MyOption::MySome` written as struct variant" instead of E0026 "variant `MyOption::MySome` does not have a field named `x`".
move stack size check to const_eval machine
This is consistent with how we enforce the step limit. In particular, we do not want this limit checked for Miri-the-tool.
polymorphize: constrain unevaluated const handling
This PR constrains the support added for handling unevaluated consts in polymorphization (introduced in #75260) by:
- Skipping associated constants as this causes cycle errors.
- Skipping promoted constants when they contain `Self` as this ensures `T` is used in constants of the form `<Self as Foo<T>>`.
Due to an oversight on my part, when landing #75260 and #75255, some tests started failing when polymorphization was enabled that I didn't notice until after landing - this PR fixes the regressions from #75260.
r? @lcnr
Miri: Renamed "undef" to "uninit"
Renamed remaining references to "undef" to "uninit" when referring to Miri.
Impacted directories are:
- `src/librustc_codegen_llvm/consts.rs`
- `src/librustc_middle/mir/interpret/`
- `src/librustc_middle/ty/print/pretty.rs`
- `src/librustc_mir/`
- `src/tools/clippy/clippy_lints/src/consts.rs`
Upon building Miri based on the new changes it was verified that no changes needed to be made with the Miri project.
Related issue #71193
Improve `f32` and `f64` primitive documentation
I noticed that the docs for the primitive floats were fairly short. I first only wanted to add the IEEE specification information (compare [the reference](https://doc.rust-lang.org/reference/types/numeric.html)), but then also added some more beginner-friendly docs. Let me know what you think!
Random doc team assign:
r? @rylev
Use intra-doc links in /library/core/src/cmp.rs
Helps with #75080.
@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc
Known issues:
* Links from `core` to `std` (#74481):
* [`Vec::sort_by_key`]
Use existing `infcx` when emitting trait impl diagnostic
Fixes#75361Fixes#74918
Previously, we were creating a new `InferCtxt`, which caused an ICE when
used with type variables from the existing `InferCtxt`
instance: only polymorphize upvar substs
This PR restricts the substitution polymorphization added in #75255 to only apply to the tupled upvar substitution, rather than all substitutions, fixing a bunch of regressions when polymorphization is
enabled.
Due to an oversight on my part, when landing #75260 and #75255, some tests started failing when polymorphization was enabled that I didn't notice until after landing - this PR fixes the regressions from #75255. #75336 has been filed to make sure that we don't forget to try make this change again in future, as it does enable some optimisations.
r? @lcnr
Don't try to use wasm intrinsics on vectors
This commit fixes an issue with #74695 where the fptosi and fptoui
specializations on wasm were accidentally used on vector types by the
`simd_cast` intrinsic. This issue showed up as broken CI for the stdsimd
crate. Here this commit simply skips the specialization on vector kinds
flowing into `fpto{s,u}i`.
Avoid deleting temporary files on error
Previously if the compiler error'd, fatally, then temporary directories which
should be preserved by -Csave-temps would be deleted due to fatal compiler
errors being implemented as panics.
cc @infinity0
(Hopefully) fixes#75275, but I haven't tested
