Add `opt_alias_variances` and use it in outlives code
...so to fix some subtle outlives bugs with precise capturing in traits, and eventually make it easier to compute variances for "forced unconstrained" trait lifetimes.
r? lcnr
Make sure to use `Receiver` trait when extracting object method candidate
In method confirmation, the `extract_existential_trait_ref` function re-extracts the object type by derefing until it reaches an object. If we're assembling methods via the `Receiver` trait, make sure we re-do our work also using the receiver trait.
Fixes#135155
cc ``@adetaylor``
Remove dead code from rustc_codegen_llvm and the LLVM wrapper
First step to clean up the LLVM wrapper: remove existing dead code.
Split out of #135502
r? ``@Zalathar``
Pattern Migration 2024: try to suggest eliding redundant binding modifiers
This is based on #136475. Only the last commit is new.
This is a simpler, more restrictive alternative to #136496, meant to partially address #136047. If a pattern can be migrated to Rust 2024 solely by removing redundant binding modifiers, this will make that suggestion; otherwise, it uses the old suggestion of making the pattern fully explicit.
Relevant tracking issue: #131414
``@rustbot`` label A-diagnostics A-patterns A-edition-2024
r? ``@Nadrieril``
MIR validation: add comment explaining the limitations of CfgChecker
I hope this right but I am not sure.^^
Cc `@compiler-errors` `@lcnr` `@cjgillot` `@oli-obk`
compiler: Clean up weird `rustc_abi` reexports
Just general cleanup in `rustc_target` and `rustc_abi`. I was originally going to make a PR with a larger change that also fixed the last few crates and in doing so removed some clutter from `rustc_abi`, but wound up slightly stuck on it, then figured out how to fix it, and then got distracted by other things... so now I'm trying to figure out what I had figured out earlier.
fix tail call checks wrt `#[track_caller]`
Only check the caller + disallow caller having the attribute.
fixes#134336
r? `@compiler-errors`
<sub>apparently there were no tests for `#[track_caller]` before... ooops</sub>
Don't reset cast kind without also updating the operand in `simplify_cast` in GVN
Consider this heavily elided segment of the pre-GVN example code that was committed as a test:
```rust
let _4: *const ();
let _5: *const [()];
let mut _6: *const ();
let _7: *mut ();
let mut _8: *const [()];
let mut _9: std::boxed::Box<()>;
let mut _10: *const ();
/* ... */
// Deref a box
_10 = copy ((_9.0: std::ptr::Unique<()>).0: std::ptr::NonNull<()>) as *const () (Transmute);
_4 = copy _10;
_6 = copy _4;
// Inlined body of `slice::from_raw_parts`, to turn a unit pointer into a slice-of-unit pointer
_5 = *const [()] from (copy _6, copy _11);
_8 = copy _5;
// Cast the raw slice-of-unit pointer back to a unit pointer
_7 = copy _8 as *mut () (PtrToPtr);
```
A malformed optimization was changing `_7` (which casted the slice-of-unit ptr to a unit ptr) to:
```
_7 = copy _5 as *mut () (Transmute);
```
...where `_8` was just replaced with `_5` bc of simple copy propagation, that part is not important... the CastKind changing to Transmute is the important part here.
In #133324, two new functionalities were implemented:
* Peeking through unsized -> sized PtrToPtr casts whose operand is `AggregateKind::RawPtr`, to turn it into PtrToPtr casts of the base of the aggregate. In this case, this allows us to see that the value of `_7` is just a ptr-to-ptr cast of `_6`.
* Folding a PtrToPtr cast of an operand which is a Transmute cast into just a single Transmute, which (theoretically) allows us to treat `_7` as a transmute into `*mut ()` of the base of the cast of `_10`, which is the place projection of `((_9.0: std::ptr::Unique<()>).0: std::ptr::NonNull<()>)`.
However, when applying those two subsequent optimizations, we must *not* update the CastKind of the final cast *unless* we also update the operand of the cast, since the operand may no longer make sense with the updated CastKind.
In this case, this is problematic because the type of `_8` is `*const [()]`, but that operand in assignment statement of `_7` does *not* get turned into something like `((_9.0: std::ptr::Unique<()>).0: std::ptr::NonNull<()>)` -- **in other words, `try_to_operand` fails** -- because GVN only turns value nodes into locals or consts, not projections of locals. So we fail to update the operand, but we still update the CastKind to Transmute, which means we now are transmuting types of different sizes (a wide pointer and a thin pointer).
r? `@scottmcm` or `@cjgillot`
Fixes#136361Fixes#135997
this commit makes `deref_into_dyn_supertrait` lint allow-by-default,
removes future incompatibility (we finally live in a broken world), and
changes the wording in the documentation.
previously documentation erroneously said that it lints against *usage*
of the deref impl, while it actually (since 104742) lints on the impl
itself (oooops, my oversight, should have updated it 2+ years ago...)
Simplify slice indexing in next trait solver
Unless I'm missing something:
- no need to explicitly specify the end of the slice as the end of the index range
- the `assert` is redundant since the indexing will panic for the same condition
I think this change simplifies it a bit. Also replaced the `for` loop of `push`es with a call to `extend` with an iterator. Might improve performance since it knows how many elements will be added beforehand and can pre-reserve room?
r? `@compiler-errors` , I think
Rollup of 7 pull requests
Successful merges:
- #136073 (Always compute coroutine layout for eagerly emitting recursive layout errors)
- #136235 (Pretty print pattern type values with transmute if they don't satisfy their pattern)
- #136311 (Ensure that we never try to monomorphize the upcasting or vtable calls of impossible dyn types)
- #136315 (Use short ty string for binop and unop errors)
- #136393 (Fix accidentally not emitting overflowing literals lints anymore in patterns)
- #136435 (Simplify some code for lowering THIR patterns)
- #136630 (Change two std process tests to not output to std{out,err}, and fix test suite stat reset in bootstrap CI test rendering)
r? `@ghost`
`@rustbot` modify labels: rollup
try-job: aarch64-gnu-debug
Simplify some code for lowering THIR patterns
I've been playing around with some radically different ways of storing THIR patterns, and while those experiments haven't yet produced a clear win, I have noticed various smaller things in the existing code that can be made a bit nicer.
Some of the more significant changes:
- With a little bit of extra effort (and thoughtful use of Arc), we can completely remove an entire layer of `'pat` lifetimes from the intermediate data structures used for match lowering.
- In several places, lists of THIR patterns were being double-boxed for no apparent reason.
Fix accidentally not emitting overflowing literals lints anymore in patterns
This was regressed in https://github.com/rust-lang/rust/pull/134228 (not in beta yet).
The issue was that previously we nested `hir::Expr` inside `hir::PatKind::Lit`, so it was linted by the expression code.
So now I've set it up for visitors to be able to directly visit literals and get all literals
Use short ty string for binop and unop errors
```
error[E0369]: cannot add `(..., ..., ..., ...)` to `(..., ..., ..., ...)`
--> $DIR/binop.rs:10:7
|
LL | x + x;
| - ^ - (..., ..., ..., ...)
| |
| (..., ..., ..., ...)
|
= note: the full name for the type has been written to '$TEST_BUILD_DIR/$FILE.long-type-hash.txt'
= note: consider using `--verbose` to print the full type name to the console
```
```
error[E0600]: cannot apply unary operator `!` to type `(..., ..., ..., ...)`
--> $DIR/binop.rs:14:5
|
LL | !x;
| ^^ cannot apply unary operator `!`
|
= note: the full name for the type has been written to '$TEST_BUILD_DIR/$FILE.long-type-hash.txt'
= note: consider using `--verbose` to print the full type name to the console
```
CC #135919.
Ensure that we never try to monomorphize the upcasting or vtable calls of impossible dyn types
Check for impossible obligations in the `dyn Trait` type we're trying to compute its the vtable upcasting and method call slots.
r? lcnr
Pretty print pattern type values with transmute if they don't satisfy their pattern
Instead of printing `0_u32 is 1..`, we now print the default fallback rendering that we also use for invalid bools, chars, ...: `{transmute(0x00000000): (u32) is 1..=}`.
These cases can occur in mir dumps when const prop propagates a constant across a safety check that would prevent the actually UB value from existing. That's fine though, as it's dead code and we always need to allow UB in dead code.
follow-up to https://github.com/rust-lang/rust/pull/136176
cc ``@compiler-errors`` ``@scottmcm``
r? ``@RalfJung`` because of the interpreter changes
