Warn on references casting to bigger memory layout
This PR extends the [`invalid_reference_casting`](https://doc.rust-lang.org/rustc/lints/listing/deny-by-default.html#invalid-reference-casting) lint (*deny-by-default*) which currently lint on `&T -> &mut T` casting to also lint on `&(mut) A -> &(mut) B` where `size_of::<B>() > size_of::<A>()` (bigger memory layout requirement).
The goal is to detect such cases:
```rust
let u8_ref: &u8 = &0u8;
let u64_ref: &u64 = unsafe { &*(u8_ref as *const u8 as *const u64) };
//~^ ERROR casting references to a bigger memory layout is undefined behavior
let mat3 = Mat3 { a: Vec3(0i32, 0, 0), b: Vec3(0, 0, 0), c: Vec3(0, 0, 0) };
let mat3 = unsafe { &*(&mat3 as *const _ as *const [[i64; 3]; 3]) };
//~^ ERROR casting references to a bigger memory layout is undefined behavior
```
This is added to help people who write unsafe code, especially when people have matrix struct that they cast to simple array of arrays.
EDIT: One caveat, due to the [`&Header`](https://github.com/rust-lang/unsafe-code-guidelines/issues/256) uncertainty the lint only fires when it can find the underline allocation.
~~I have manually tested all the new expressions that warn against Miri, and they all report immediate UB.~~
r? ``@est31``
Rollup of 11 pull requests
Successful merges:
- #120765 (Reorder diagnostics API)
- #120833 (More internal emit diagnostics cleanups)
- #120899 (Gracefully handle non-WF alias in `assemble_alias_bound_candidates_recur`)
- #120917 (Remove a bunch of dead parameters in functions)
- #120928 (Add test for recently fixed issue)
- #120933 (check_consts: fix duplicate errors, make importance consistent)
- #120936 (improve `btree_cursors` functions documentation)
- #120944 (Check that the ABI of the instance we are inlining is correct)
- #120956 (Clean inlined type alias with correct param-env)
- #120962 (Add myself to library/std review)
- #120972 (fix ICE for deref coercions with type errors)
r? `@ghost`
`@rustbot` modify labels: rollup
Assert that params with the same *index* have the same *name*
Found this bug when trying to build libcore with the new solver, since it will canonicalize two params with the same index into *different* placeholders if those params differ by name.
Invert diagnostic lints.
That is, change `diagnostic_outside_of_impl` and `untranslatable_diagnostic` from `allow` to `deny`, because more than half of the compiler has been converted to use translated diagnostics.
This commit removes more `deny` attributes than it adds `allow` attributes, which proves that this change is warranted.
r? ````@davidtwco````
Rollup of 9 pull requests
Successful merges:
- #119592 (resolve: Unload speculatively resolved crates before freezing cstore)
- #120103 (Make it so that async-fn-in-trait is compatible with a concrete future in implementation)
- #120206 (hir: Make sure all `HirId`s have corresponding HIR `Node`s)
- #120214 (match lowering: consistently lower bindings deepest-first)
- #120688 (GVN: also turn moves into copies with projections)
- #120702 (docs: also check the inline stmt during redundant link check)
- #120727 (exhaustiveness: Prefer "`0..MAX` not covered" to "`_` not covered")
- #120734 (Add `SubdiagnosticMessageOp` as a trait alias.)
- #120739 (improve pretty printing for associated items in trait objects)
r? `@ghost`
`@rustbot` modify labels: rollup
That is, change `diagnostic_outside_of_impl` and
`untranslatable_diagnostic` from `allow` to `deny`, because more than
half of the compiler has be converted to use translated diagnostics.
This commit removes more `deny` attributes than it adds `allow`
attributes, which proves that this change is warranted.
make matching on NaN a hard error, and remove the rest of illegal_floating_point_literal_pattern
These arms would never be hit anyway, so the pattern makes little sense. We have had a future-compat lint against float matches in general for a *long* time, so I hope we can get away with immediately making this a hard error.
This is part of implementing https://github.com/rust-lang/rfcs/pull/3535.
Closes https://github.com/rust-lang/rust/issues/41620 by removing the lint.
https://github.com/rust-lang/reference/pull/1456 updates the reference to match.
Don't hash lints differently to non-lints.
`Diagnostic::keys`, which is used for hashing and equating diagnostics, has a surprising behaviour: it ignores children, but only for lints. This was added in #88493 to fix some duplicated diagnostics, but it doesn't seem necessary any more.
This commit removes the special case and only four tests have changed output, with additional errors. And those additional errors aren't exact duplicates, they're just similar. For example, in src/tools/clippy/tests/ui/same_name_method.rs we currently have this error:
```
error: method's name is the same as an existing method in a trait
--> $DIR/same_name_method.rs:75:13
|
LL | fn foo() {}
| ^^^^^^^^^^^
|
note: existing `foo` defined here
--> $DIR/same_name_method.rs:79:9
|
LL | impl T1 for S {}
| ^^^^^^^^^^^^^^^^
```
and with this change we also get this error:
```
error: method's name is the same as an existing method in a trait
--> $DIR/same_name_method.rs:75:13
|
LL | fn foo() {}
| ^^^^^^^^^^^
|
note: existing `foo` defined here
--> $DIR/same_name_method.rs:81:9
|
LL | impl T2 for S {}
|
```
I think printing this second argument is reasonable, possibly even preferable to hiding it. And the other cases are similar.
r? `@estebank`
`Diagnostic::keys`, which is used for hashing and equating diagnostics,
has a surprising behaviour: it ignores children, but only for lints.
This was added in #88493 to fix some duplicated diagnostics, but it
doesn't seem necessary any more.
This commit removes the special case and only four tests have changed
output, with additional errors. And those additional errors aren't
exact duplicates, they're just similar. For example, in
src/tools/clippy/tests/ui/same_name_method.rs we currently have this
error:
```
error: method's name is the same as an existing method in a trait
--> $DIR/same_name_method.rs:75:13
|
LL | fn foo() {}
| ^^^^^^^^^^^
|
note: existing `foo` defined here
--> $DIR/same_name_method.rs:79:9
|
LL | impl T1 for S {}
| ^^^^^^^^^^^^^^^^
```
and with this change we also get this error:
```
error: method's name is the same as an existing method in a trait
--> $DIR/same_name_method.rs:75:13
|
LL | fn foo() {}
| ^^^^^^^^^^^
|
note: existing `foo` defined here
--> $DIR/same_name_method.rs:81:9
|
LL | impl T2 for S {}
| ^^^^^^^^^^^^^^^^
```
I think printing this second argument is reasonable, possibly even
preferable to hiding it. And the other cases are similar.
Remove various `has_errors` or `err_count` uses
follow up to https://github.com/rust-lang/rust/pull/119895
r? `@nnethercote` since you recently did something similar.
There are so many more of these, but I wanted to get a PR out instead of growing the commit list indefinitely. The commits all work on their own and can be reviewed commit by commit.
The query accept arbitrary DefIds, not just owner DefIds.
The return can be an `Option` because if there are no nodes, then it doesn't matter whether it's due to NonOwner or Phantom.
Also rename the query to `opt_hir_owner_nodes`.
remove StructuralEq trait
The documentation given for the trait is outdated: *all* function pointers implement `PartialEq` and `Eq` these days. So the `StructuralEq` trait doesn't really seem to have any reason to exist any more.
One side-effect of this PR is that we allow matching on some consts that do not implement `Eq`. However, we already allowed matching on floats and consts containing floats, so this is not new, it is just allowed in more cases now. IMO it makes no sense at all to allow float matching but also sometimes require an `Eq` instance. If we want to require `Eq` we should adjust https://github.com/rust-lang/rust/pull/115893 to check for `Eq`, and rule out float matching for good.
Fixes https://github.com/rust-lang/rust/issues/115881
`unescape_literal` becomes `unescape_unicode`, and `unescape_c_string`
becomes `unescape_mixed`. Because rfc3349 will mean that C string
literals will no longer be the only mixed utf8 literals.
Pack u128 in the compiler to mitigate new alignment
This is based on #116672, adding a new `#[repr(packed(8))]` wrapper on `u128` to avoid changing any of the compiler's size assertions. This is needed in two places:
* `SwitchTargets`, otherwise its `SmallVec<[u128; 1]>` gets padded up to 32 bytes.
* `LitKind::Int`, so that entire `enum` can stay 24 bytes.
* This change definitely has far-reaching effects though, since it's public.
Don't forget that the lifetime on hir types is `'tcx`
This PR just tracks the `'tcx` lifetime to wherever the original objects actually have that lifetime. This code is needed for https://github.com/rust-lang/rust/pull/107606 (now #120131) so that `ast_ty_to_ty` can invoke `lit_to_const` on an argument passed to it. Currently the argument is `&hir::Ty<'_>`, but after this PR it is `&'tcx hir::Ty<'tcx>`.
