There are a number of things I dislike about `CrateMetadataRef`.
- It contains two fields `cstore` and `cdata`. The latter points to data
within the former. It's like having an `Elem` type that has a
reference to a vec element and also a reference to the vec itself.
Weird.
- The `cdata` field gets a lot of use, and the `Deref` impl just derefs
that field. The `cstore` field is rarely used.
- `CrateMetadataRef` is not a good name.
- Variables named `cdata` sometimes refer to values of this type and
sometimes to values of type `CrateMetadata`, which is confusing.
The good news is that `CrateMetadataRef` is not necessary and can be
replaced with `&CrateMetadata`. Why? Everywhere that `CrateMetadataRef`
is used, a `TyCtxt` is also present, and the `CStore` is accessible from
the `TyCtxt` with `CStore::from_tcx`.
So this commit removes `CrateMetadataRef` and replaces all its uses with
`&CrateMetadata`. Notes:
- This requires adding only two uses of `CStore::from_tcx`, which shows
how rarely the `cstore` field was used.
- `get_crate_data` now matches `get_crate_data_mut` more closely.
- A few variables are renamed for consistency, e.g. `data`/`cmeta` ->
`cdata`.
- An unnecessary local variable (`local_cdata`) in `decode_expn_id` is
removed.
- All the `CrateMetadataRef` methods become `CrateMetadata` methods, and
their receiver changes from `self` to `&self`.
- `RawDefId::decode_from_cdata` is inlined and removed, because it has a
single call site.
Rollup of 7 pull requests
Successful merges:
- rust-lang/rust#155469 (Account for titlecase in casing lints)
- rust-lang/rust#155644 (delegation: support self ty propagation for functions in free to trait reuse)
- rust-lang/rust#154957 (Fix ICE when const closure appears inside a non-const trait method)
- rust-lang/rust#155442 (Change keyword order for `impl` restrictions)
- rust-lang/rust#155561 (Use singular wording for single _ placeholders in type suggestions)
- rust-lang/rust#155637 (Fix E0191 suggestion for empty dyn trait args)
- rust-lang/rust#155661 (Remove `AttributeLintKind` variants - part 6)
Change keyword order for `impl` restrictions
Based on rust-lang/rust#155222, this PR reorders keywords in trait definitions to group restrictions with visibility. It changes the order from `pub(...) const unsafe auto impl(...) trait Foo {...}` to `pub(...) impl(...) const unsafe auto trait Foo {...}`.
Tracking issue for restrictions: rust-lang/rust#105077
r? @Urgau
cc @jhpratt
Fix ICE when const closure appears inside a non-const trait method
Fixesrust-lang/rust#153891
`hir_body_const_context()` unconditionally delegated to the parent's const context for const closures, returning `None` when the parent had no const context. This caused `mir_const_qualif()` to hit a `span_bug!`, since `mir_promoted()` had already decided to call it based on the closure's own syntactic constness. Fall back to `ConstContext::ConstFn` when the parent's const context is `None`, so that the const closure body is still properly const-checked rather than triggering an ICE.
Examining [another attempt](https://github.com/rust-lang/rust/pull/153900/changes) at this issue (which has already been closed), I thought that its approach represents a workaround fix to avoid inconsistencies in the caller of `mir_promoted()`, whereas I think the correct behavior is for `hir_body_const_context()` itself to return the proper value.
delegation: support self ty propagation for functions in free to trait reuse
This PR adds support for self types specified in free to trait reuse. Up to this point we always generated `Self` despite the fact whether self type was specified or not. Now we use it in signature inheritance. Moreover we no more generate `Self` for static methods. Part of rust-lang/rust#118212.
```rust
trait Trait<T> {
fn foo<const B: bool>(&self) {}
fn bar() {}
}
impl<T> Trait<T> for usize {}
reuse <usize as Trait>::foo;
// Desugaring (no `Self` as usize is specified)
fn foo<T, const B: bool>(self: &usize) {
<usize as Trait::<T>>::foo::<B>(self)
}
reuse Trait::bar;
// Desugaring (no `Self` as static method)
fn bar<T>() {
Trait::<T>::bar(); //~ERROR: type annotations needed
}
```
r? @petrochenkov
Streamline `CrateMetadataRef` construction in `provide_one!`.
`cstore.get_crate_data()` creates a `CrateMetadataRef`, which is exactly what we need. The current code is very confused and does several unnecessary things: mapping the `FreezeReadGuard` and calling `CStore::from_tcx` a second time to construct a second `CrateMetadataRef`.
This is a small perf win.
r? @mu001999
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.
Nicholas Nethercote