rustc_llvm: update opt-level handling for LLVM 23
LLVM 23 removed Os and Oz optimization pipelines and the PR says to use O2 with optsize or minsize instead as appropriate.
See https://github.com/llvm/llvm-project/pull/191363 for more details.
rustc_thread_pool: Make `CoreLatch::set` use `SeqCst` instead of `AcqRel`
Every other modification of this variable uses `SeqCst`, which is justified in the sleep README. This particular choice of `AcqRel` was not discussed during its addition in rayon-rs/rayon#746, nor rayon-rs/rfcs#5, so I suspect was simply an oversight from earlier development. We probably do want this to participate in the same sequential consistency.
The only other ordering difference is `CoreLatch::probe`'s load with `Acquire`, which should be fine because this doesn't need consistency with the sleep counters.
See also rayon-rs/rayon#1297. As I commented there, I think in practice this would be quite rare to cause any problems, but it *could* be a source of non-deterministic bugs on targets with weak memory ordering.
Replace `ShardedHashMap` method `insert` with debug-checked `insert_unique`
Currently every use of `ShardedHashMap::insert` checks that it won't evict an old value due to unique key. I haven't found any issue related to that faulty condition, so I thought of replacing it with `ShardedHashMap::insert_unique` which doesn't check for this condition unless `debug_assertions` are enabled. This might improve the performance.
r? @petrochenkov
BinOpAssign always returns unit
I don't know why we treated assign ops as returning their binop type sometimes, but it's usually ignored later anyway and mostly affects infer vars.
Also updated a comment from 11 years ago when SIMD types apparently had builtin `==` logic.
Immediately feed visibility on DefId creation
This system was originally introduced in rust-lang/rust#121089
This PR was enabled by refactorings in rust-lang/rust#154945, because after that, the visibility feeding happens directly after the `DefId` creation, so we don't need to go through the intermediate hash table anymore
Should unblock rust-lang/rust#138995
Remove `nodes_in_current_session` field and related assertions
This removes the `nodes_in_current_session` field and related assertions. These are enabled if `-Z incremental-verify-ich` is passed or `debug_assertions` is on. Historically these have been useful to catch query keys with improper `HashStable` impls which lead to collisions.
We currently also check for duplicate nodes when loading the dep graph. This check is more complete as it covers the entire dep graph and is enabled by default. It doesn't provide a query key for a collision however. This check is also delayed to the next incremental session.
We also have the `verify_query_key_hashes` which is also enabled if `-Z incremental-verify-ich` is passed or `debug_assertions` is on. This checks for dep node conflicts in each query cache and provides 2 conflicting keys if present.
I think these remaining checks are sufficient and so we can remove `nodes_in_current_session`.
codegen: Copy to an alloca when the argument is neither by-val nor by-move for indirect pointer.
Fixes https://github.com/rust-lang/rust/issues/155241.
When a value is passed via an indirect pointer, the value needs to be copied to a new alloca. For x86_64-unknown-linux-gnu, `Thing` is the case:
```rust
#[derive(Clone, Copy)]
struct Thing(usize, usize, usize);
pub fn foo() {
let thing = Thing(0, 0, 0);
bar(thing);
assert_eq!(thing.0, 0);
}
#[inline(never)]
#[unsafe(no_mangle)]
pub fn bar(mut thing: Thing) {
thing.0 = 1;
}
```
Before passing the thing to the bar function, the thing needs to be copied to an alloca that is passed to bar.
```llvm
%0 = alloca [24 x i8], align 8
call void @llvm.memcpy.p0.p0.i64(ptr align 8 %0, ptr align 8 %thing, i64 24, i1 false)
call void @bar(ptr %0)
```
This patch applies the rule to the untupled arguments as well.
```rust
#![feature(fn_traits)]
#[derive(Clone, Copy)]
struct Thing(usize, usize, usize);
#[inline(never)]
#[unsafe(no_mangle)]
pub fn foo() {
let thing = (Thing(0, 0, 0),);
(|mut thing: Thing| {
thing.0 = 1;
}).call(thing);
assert_eq!(thing.0.0, 0);
}
```
For this case, this patch changes from
```llvm
; call example::foo::{closure#0}
call void @_RNCNvCs15qdZVLwHPA_7example3foo0B3_(ptr ..., ptr %thing)
```
to
```llvm
%0 = alloca [24 x i8], align 8
call void @llvm.memcpy.p0.p0.i64(ptr align 8 %0, ptr align 8 %thing, i64 24, i1 false)
; call example::foo::{closure#0}
call void @_RNCNvCs15qdZVLwHPA_7example3foo0B3_(ptr ..., ptr %0)
```
However, the same rule cannot be applied to tail calls that would be unsound, because the caller's stack frame is overwritten by the callee's stack frame. Fortunately, https://github.com/rust-lang/rust/pull/151143 has already handled the special case. We must not copy again.
No copy is needed for by-move arguments, because the argument is passed to the called "in-place".
No copy is also needed for by-val arguments, because the attribute implies that a hidden copy of the pointee is made between the caller and the callee.
NOTE: The patch has a trick for tail calls that we pass by-move. We can choose to copy an alloca even for by-move arguments, but tail calls require MUST-by-move.
we were saying that the type is i32, but would often provide an i64.
That never failed so far, but starts failing (like, crashing LLVM) when
working with 128-bit values that are 16-byte aligned. So, we may as well
use the more robust approach now.
Rollup of 7 pull requests
Successful merges:
- rust-lang/rust#155589 (Forbid `check-pass`/`build-pass`/`run-pass` directives in incremental tests)
- rust-lang/rust#155610 (Add missing `dyn` keyword to `trait_alias` page of the Unstable Book)
- rust-lang/rust#155615 (test cleanups for `ui/derives` and `ui/deriving`)
- rust-lang/rust#154874 (Fix ICE for inherited const conditions on const closures)
- rust-lang/rust#155605 (std: Update support for `wasm32-wasip3`)
- rust-lang/rust#155613 (c-variadic: tweak `std` docs)
- rust-lang/rust#155619 (Remove a bunch of unnecessary explicit lifetimes from the ast validator)
Remove a bunch of unnecessary explicit lifetimes from the ast validator
Noticed while fiddling with error reporting. None of the lifetimes were ever used for anything
Fix ICE for inherited const conditions on const closures
Synchronize `evaluate_host_effect_for_fn_goal` with the behavior of `extract_fn_def_from_const_callable` in new solver.
Closesrust-lang/rust#153861 .
It's currently an impl for `(CrateMetadataRef, TyCtxt)`, but (a) the
`TyCtxt` is not used, and (b) the `CrateMetadataRef` can be simplified
to a `CrateMetadata` because `CStore` access isn't required. This
require changing `blob` to take `&self`, which is no big deal, and it
simplifies many `get` calls.
`Metadata` has two methods, `blob` and `decoder`, which are not used
together. Splitting the trait in two will allow some cleanups in
subsequent commits.
Use per-parent disambiguators everywhere
This PR addressing the following concerns about per-parent disambiguators (rust-lang/rust#153955):
- DisambiguatorState is removed, PerParentDisambiguatorState is now used everywhere,
- Steals were removed from every per-parent disambiguator in resolver,
- It adds `parent` field in `PerParentDisambiguatorState` in `#[cfg(debug_assertions)]` for asserting that per-parent disambiguator corresponds to the same `LocalDefId` which is passed into `create_def`,
- ~Removes `Disambiguator` trait replacing it with `Disambiguator` enum, with this change we no longer expose `next` method (as trait should be public otherwise the warning will be emitted). It may affect perf in a negative way though.~
~Those changes should not fix perf issues that were [reported](https://github.com/rust-lang/rust/pull/153955#issuecomment-4269223191), perf run that was attempted [before](https://github.com/rust-lang/rust/pull/153955#issuecomment-4214516698) showed much better results. Performance can be probably fixed by removing per-parent disambiguators replacing them with a single one as it was before, then it will be passed to AST -> HIR lowering and modified. For delayed owners we can store ~followup disambiguators as it was in the beginning of the rust-lang/rust#153955~ per-parent disambiguators. This solution should save achievements from rust-lang/rust#153955 (removed `DefPathData` variants).
However, I would prefer to keep per-parent disambiguators as it seems a better architectural solution for me.~
r? @petrochenkov
cc @oli-obk
Remove duplicated `Flags` methods.
The `Flags` trait has two methods: `flags` and `outer_exclusive_binder`. Multiple types impl this trait and then also have duplicate inherent methods with the same names; these are all marked with "Think about removing this" comments. This is left over from things being moved into `rustc_type_ir`.
This commit removes those inherent methods. This requires adding `use Flags` to a number of files.
r? @lcnr
Fix incorrect `let` to `const` suggestion for pattern bindings
When a variable from a pattern binding was referenced inside a `const {}` block, the compiler incorrectly suggested replacing `let` with `const`. This was reported in rust-lang/rust#152831 for `if let`, but also applies to `while let` and `let ... else`.
Improve E0308 error message for `impl Trait` return mismatches
When a function returns `impl Trait`, all branches must return the same concrete type. Previously, the compiler showed:
expected `First` because of return type
This was misleading, as it suggested the return type was `First`, rather than any single type implementing the trait.
Update the diagnostic to:
expected a single type implementing `Value` because of return type
Also highlight the first return expression to make it clearer why subsequent returns do not match.
Every other modification of this variable uses `SeqCst`, which is
justified in the sleep README. This particular choice of `AcqRel` was
not discussed during its addition in rayon-rs/rayon#746, nor
rayon-rs/rfcs#5, so I suspect was simply an oversight from earlier
development. We probably do want this to participate in the same
sequential consistency.
The only other ordering difference is `CoreLatch::probe`'s load with
`Acquire`, which should be fine because this doesn't need consistency
with the sleep counters.
See also rayon-rs/rayon#1297. As I commented there, I think in practice
this would be quite rare to cause any problems, but it *could* be a
source of non-deterministic bugs on targets with weak memory ordering.
León Orell Valerian Liehr