This initial implementation handles transmutations between types with specified layouts, except when references are involved.
Co-authored-by: Igor null <m1el.2027@gmail.com>
lint: add bad opt access internal lint
Prompted by [Zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/sess.2Ecrate_types.28.29.20vs.20sess.2Eopts.2Ecrate_types/near/290682847).
Some command-line options accessible through `sess.opts` are best accessed through wrapper functions on `Session`, `TyCtxt` or otherwise, rather than through field access on the option struct in the `Session`.
Adds a new lint which triggers on those options that should be accessed through a wrapper function so that this is prohibited. Options are annotated with a new attribute `rustc_lint_opt_deny_field_access` which can specify the error message (i.e. "use this other function instead") to be emitted.
A simpler alternative would be to simply rename the options in the option type so that it is clear they should not be used, however this doesn't prevent uses, just discourages them. Another alternative would be to make the option fields private, and adding accessor functions on the option types, however the wrapper functions sometimes rely on additional state from `Session` or `TyCtxt` which wouldn't be available in an function on the option type, so the accessor would simply make the field available and its use would be discouraged too.
**Leave a comment if there's an option I should add this to.**
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
Remove let-chain close brace check.
#98633 added some checks to forbid let-expressions that aren't in a let chain. This check looks at the preceding token to determine if it is a valid let-chain position. One of those tokens it checks is the close brace `}`. However, to my understanding, it is not possible for a let chain to be preceded by a close brace. This PR removes the check to avoid any confusion.
This is a followup to the discussion at https://github.com/rust-lang/rust/pull/98633#pullrequestreview-1030962803. It wasn't clear what issues the original PR ran into, but I have run the full set of CI tests and nothing failed. I also can't conceive of a situation where this would be possible. This doesn't reject any valid code, I'm just removing it to avoid confusion to anyone looking at this code in the future.
Replace the separate AbortCodegenOnDrop guard by integrating this
functionality into OngoingCodegen (or rather, the Coordinator part
of it). This ensures that we send a CodegenAborted message and
wait for workers to finish even if the panic occurs outside
codegen_crate() (e.g. inside join_codegen()).
This requires some minor changes to the handling of CodegenAborted,
as it can now occur when the main thread is LLVMing rather than
Codegenning.
Some command-line options accessible through `sess.opts` are best
accessed through wrapper functions on `Session`, `TyCtxt` or otherwise,
rather than through field access on the option struct in the `Session`.
Adds a new lint which triggers on those options that should be accessed
through a wrapper function so that this is prohibited. Options are
annotated with a new attribute `rustc_lint_opt_deny_field_access` which
can specify the error message (i.e. "use this other function instead")
to be emitted.
A simpler alternative would be to simply rename the options in the
option type so that it is clear they should not be used, however this
doesn't prevent uses, just discourages them. Another alternative would
be to make the option fields private, and adding accessor functions on
the option types, however the wrapper functions sometimes rely on
additional state from `Session` or `TyCtxt` which wouldn't be available
in an function on the option type, so the accessor would simply make the
field available and its use would be discouraged too.
Signed-off-by: David Wood <david.wood@huawei.com>
If an internal lint uses `typeck_results` or similar queries then that
can result in rustdoc checking code that it shouldn't (e.g. from other
platforms) and emit compilation errors.
Signed-off-by: David Wood <david.wood@huawei.com>
Sync rustc_codegen_cranelift
I did a large refactoring of the intrinsics module to remove the intrinsic_match macro which is not very clear to other people. This also enables rustfmt to run on this code. While I already did a sync yesterday, I am going to do another sync again to avoid potential conflicts as those will likely be painful to resolve.
r? ``@ghost``
``@rustbot`` label +A-codegen +A-cranelift +T-compiler
Check that RPITs constrained by a recursive call in a closure are compatible
Fixes#99073
Adapts a similar visitor pattern to `find_opaque_ty_constraints` (that we use to check TAITs), but with some changes:
0. Only walk the "OnlyBody" children, instead of all items in the RPIT's defining scope
1. Only walk through the body's children if we found a constraining usage
2. Don't actually do any inference, just do a comparison and error if they're mismatched
----
r? `@oli-obk` -- you know all this impl-trait stuff best... is this the right approach? I can explain the underlying issue better if you'd like, in case that might reveal a better solution. Not sure if it's possible to gather up the closure's defining usages of the RPIT while borrowck'ing the outer function, that might be a better place to put this check...
Add a brief comment explaining why the diagnostic migration lints aren't
included in the `rustc::internal` diagnostic group.
Signed-off-by: David Wood <david.wood@huawei.com>
passes: port more of `check_attr` module
Continues from #99213.
Port more diagnostics in `rustc_passes::check_attr` to using the diagnostic derive and translation machinery.
r? `@compiler-errors`
Prefer visibility map parents that are not `doc(hidden)` first
Far simpler approach to #98876.
This only fixes the case where the parent is `doc(hidden)`, not where the child is `doc(hidden)` since I don't know how to get the attrs on the import statement given a `ModChild`... I'll try to follow up with that, but this is a good first step.
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.
