miri: make vtable addresses not globally unique
Miri currently gives vtables a unique global address. That's not actually matching reality though. So this PR enables Miri to generate different addresses for the same type-trait pair.
To avoid generating an unbounded number of `AllocId` (and consuming unbounded amounts of memory), we use the "salt" technique that we also already use for giving constants non-unique addresses: the cache is keyed on a "salt" value n top of the actually relevant key, and Miri picks a random salt (currently in the range `0..16`) each time it needs to choose an `AllocId` for one of these globals -- that means we'll get up to 16 different addresses for each vtable. The salt scheme is integrated into the global allocation deduplication logic in `tcx`, and also used for functions and string literals. (So this also fixes the problem that casting the same function to a fn ptr over and over will consume unbounded memory.)
r? `@saethlin`
Fixes https://github.com/rust-lang/miri/issues/3737
fix: Missing non-exhaustive let diagnostics inside async or unsafe block
The reason that this test doesn't have a pointer deref case is because the following code;
```rust
fn test(ptr: *const Result<i32, !>) {
unsafe {
let Ok(_x) = *ptr;
}
}
```
is getting a block with no stmts but tail one in here(thus, no diagnostic error),
0daeb5c0b0/crates/hir-ty/src/diagnostics/expr.rs (L256-L257)
while the following is getting a block with a single stmt without tail 🤔
```rust
fn test(x: Result<i32, &'static !>) {
let Ok(_y) = x;
}
```
I'll make a more deep inspection and file this as a new issue
_Originally posted by `@ShoyuVanilla` in https://github.com/rust-lang/rust-analyzer/pull/17853#discussion_r1712993585_
fix: Resolve included files to their calling modules in IDE layer
Fixes https://github.com/rust-lang/rust-analyzer/issues/17390 at the expense of reporting duplicate diagnostics for modules that have includes in them when both the calling and called file are included.
internal: Reply to requests with defaults when vfs is still loading
There is no reason for us to hit the database with queries when we certainly haven't reached a stable state yet. Instead we just reply with default request results until we are in a state where we can do meaningful work. This should save us from wasting resources while starting up at worst, and at best save us from creating query and interning entries that are non-meaningful which ultimately just end up wasting memory.
internal: Optimize the usage of channel senders
Used `Sender` directly instead of a boxed closure. There is no need to use the boxed closure. This also allows the caller to decide to do something other than `unwrap` (not a fan of it BTW).
Reuse recursion limit as expansion limit
A configurable recursion limit was introduced by looking at the recursion_limit crate attribute. Instead of relying on a global constant we will reuse this value for expansion limit as well.
Addresses: https://github.com/rust-lang/rust-analyzer/issues/8640#issuecomment-2271740272
feat: Implement TAIT and fix ATPIT a bit
Closes#16296 (Commented on the issue)
In #16852, I implemented ATPIT, but as I didn't discern ATPIT and other non-assoc TAIT, I guess that it has been working for some TAITs.
As the definining usage of TAIT requires it should be appear in the Def body's type(const blocks' type annotations or functions' signatures), this can be done in simlilar way with ATPIT
And this PR also corrects some defining-usage resolution for ATPIT
fix: #128855 Ensure `Guard`'s `drop` method is removed at `opt-level=s` for `…
fix: #128855
…Copy` types
Added `#[inline]` to the `drop` method in the `Guard` implementation to ensure that the method is removed by the compiler at optimization level `opt-level=s` for `Copy` types. This change aims to align the method's behavior with optimization expectations and ensure it does not affect performance.
r? `@scottmcm`
Apply "polymorphization at home" to RawVec
The idea here is to move all the logic in RawVec into functions with explicit size and alignment parameters. This should eliminate all the fussing about how tweaking RawVec code produces large swings in compile times.
This uncovered https://github.com/rust-lang/rust-clippy/issues/12979, so I've modified the relevant test in a way that tries to preserve the spirit of the test without tripping the ICE.
Fix `ElaborateBoxDerefs` on debug varinfo
Slightly simplifies the `ElaborateBoxDerefs` pass to fix cases where it was applying the wrong projections to debug var infos containing places that deref boxes.
From what I can tell[^1], we don't actually have any tests (or code anywhere, really) that exercise `debug x => *(...: Box<T>)`, and it's very difficult to trigger this in surface Rust, so I wrote a custom MIR test.
What happens is that the pass was turning `*(SOME_PLACE: Box<T>)` into `*(*((((SOME_PLACE).0: Unique<T>).0: NonNull<T>).0: *const T))` in debug var infos. In particular, notice the *double deref*, which was wrong.
This is the root cause of #128554, so this PR fixes#128554 as well. The reason that async closures was affected is because of the way that we compute the [`ByMove` body](https://github.com/rust-lang/rust/blob/master/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs), which resulted in `*(...: Box<T>)` in debug var info. But this really has nothing to do with async closures.
[^1]: Validated by literally replacing the `if elem == PlaceElem::Deref && base_ty.is_box() { ... }` innards with a `panic!()`, which compiled all of stage2 without panicking.
Improve `Ord` violation help
Recent experience in #128083 showed that the panic message when an Ord violation is detected by the new sort implementations can be confusing. So this PR aims to improve it, together with minor bug fixes in the doc comments for sort*, sort_unstable* and select_nth_unstable*.
Is it possible to get these changes into the 1.81 release? It doesn't change behavior and would greatly help when users encounter this panic for the first time, which they may after upgrading to 1.81.
Tagging `@orlp`
