Avoid cloning jump threading state when possible
The current implementation of jump threading passes most of its time cloning its state. This PR attempts to avoid such clones by special-casing the last predecessor when recursing through a terminator.
This is not optimal, but a first step while I refactor the state data structure to be sparse.
The two other commits are drive-by.
Fixes https://github.com/rust-lang/rust/issues/116721
r? `@oli-obk`
Rollup of 9 pull requests
Successful merges:
- #123237 (Various rustc_codegen_ssa cleanups)
- #126960 (Improve error message in tidy)
- #127002 (Implement `x perf` as a separate tool)
- #127081 (Add a run-make test that LLD is not being used by default on the x64 beta/stable channel)
- #127106 (Improve unsafe extern blocks diagnostics)
- #127110 (Fix a error suggestion for E0121 when using placeholder _ as return types on function signature.)
- #127114 (fix: prefer `(*p).clone` to `p.clone` if the `p` is a raw pointer)
- #127118 (Show `used attribute`'s kind for user when find it isn't applied to a `static` variable.)
- #127122 (Remove uneccessary condition in `div_ceil`)
r? `@ghost`
`@rustbot` modify labels: rollup
Show `used attribute`'s kind for user when find it isn't applied to a `static` variable.
For example :
```rust
extern "C" {
#[used] //~ ERROR attribute must be applied to a `static` variable
static FOO: i32; // show the kind of this item to help user understand why the error is reported.
}
```
fixes#126789
fix: prefer `(*p).clone` to `p.clone` if the `p` is a raw pointer
Fixes https://github.com/rust-lang/rust/issues/126863
I wonder if there is a better way to solve the regression problem of this test case:
`tests/ui/borrowck/issue-20801.rs`.
It's okay to drop the dereference symbol in this scenario.
But it's not correct in https://github.com/rust-lang/rust/issues/126863
```
help: consider removing the dereference here
|
5 - let inner: String = *p;
5 + let inner: String = p;
```
I haven't found out how to tell if clone pointer is allowed, i.e. no type mismatch occurs
Fix a error suggestion for E0121 when using placeholder _ as return types on function signature.
Recommit after refactoring based on comment:
https://github.com/rust-lang/rust/pull/126017#issuecomment-2189149361
But when changing return type's lifetime to `ReError` will affect the subsequent borrow check process and cause test11 in typeck_type_placeholder_item.rs to lost E0515 message.
```rust
fn test11(x: &usize) -> &_ {
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
&x //~ ERROR cannot return reference to function parameter(this E0515 msg will disappear)
}
```
fixes#125488
r? ``@pnkfelix``
Improve unsafe extern blocks diagnostics
Closes#126327
For this code:
```rust
extern {
pub fn foo();
pub safe fn bar();
}
```
We get ...
```
error: items in unadorned `extern` blocks cannot have safety qualifiers
--> test.rs:3:5
|
3 | pub safe fn bar();
| ^^^^^^^^^^^^^^^^^^
|
help: add unsafe to this `extern` block
|
1 | unsafe extern {
| ++++++
error[E0658]: `unsafe extern {}` blocks and `safe` keyword are experimental
--> test.rs:3:9
|
3 | pub safe fn bar();
| ^^^^
|
= note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
= help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0658`.
```
And then making the extern block unsafe, we get ...
```
error: extern block cannot be declared unsafe
--> test.rs:1:1
|
1 | unsafe extern {
| ^^^^^^
|
= note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
= help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
error: items in unadorned `extern` blocks cannot have safety qualifiers
--> test.rs:3:5
|
3 | pub safe fn bar();
| ^^^^^^^^^^^^^^^^^^
error[E0658]: `unsafe extern {}` blocks and `safe` keyword are experimental
--> test.rs:3:9
|
3 | pub safe fn bar();
| ^^^^
|
= note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
= help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0658`.
```
r? ``@compiler-errors``
Implement new effects desugaring
cc `@rust-lang/project-const-traits.` Will write down notes once I have finished.
* [x] See if we want `T: Tr` to desugar into `T: Tr, T::Effects: Compat<true>`
* [x] Fix ICEs on `type Assoc: ~const Tr` and `type Assoc<T: ~const Tr>`
* [ ] add types and traits to minicore test
* [ ] update rustc-dev-guide
Fixes#119717Fixes#123664Fixes#124857Fixes#126148
Move binder and polarity parsing into `parse_generic_ty_bound`
Let's pull out the parts of #127054 which just:
1. Make the parsing code less confusing
2. Fix `?use<>` (to correctly be denied)
3. Improve `T: for<'a> 'a` diagnostics
This should have no user-facing effects on stable parsing.
r? fmease
rustc_data_structures: Explicitly check for 64-bit atomics support
Instead of keeping a list of architectures which have native support
for 64-bit atomics, just use #[cfg(target_has_atomic = "64")] and its
inverted counterpart to determine whether we need to use portable
AtomicU64 on the target architecture.
Rename `super_predicates_of` and similar queries to `explicit_*` to note that they're not elaborated
Rename:
* `super_predicates_of` -> `explicit_super_predicates_of`
* `implied_predicates_of` -> `explicit_implied_predicates_of`
* `supertraits_containing_assoc_item` -> `explicit_supertraits_containing_assoc_item`
This makes it clearer that, unlike (for example) [`TyCtxt::super_traits_of`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/context/struct.TyCtxt.html#method.super_traits_of), we don't automatically elaborate this set of predicates.
r? ``@lcnr`` or ``@oli-obk`` or someone from t-types idc
Recommit after refactoring based on comment:
https://github.com/rust-lang/rust/pull/126017#issuecomment-2189149361
But when changing return type's lifetime to `ReError` will affect the subsequent borrow check process and cause test11 in typeck_type_placeholder_item.rs to lost E0515 message.
```rust
fn test11(x: &usize) -> &_ {
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
&x //~ ERROR cannot return reference to function parameter(this E0515 msg will disappear)
}
```
Rollup of 11 pull requests
Successful merges:
- #123714 (Add test for fn pointer duplication.)
- #124091 (Update AST validation module docs)
- #127015 (Switch back `non_local_definitions` lint to allow-by-default)
- #127016 (docs: check if the disambiguator matches its suffix)
- #127029 (Fix Markdown tables in platform-support.md)
- #127032 (Enable const casting for `f16` and `f128`)
- #127055 (Mark Hasher::finish as #[must_use])
- #127068 (Stall computing instance for drop shim until it has no unsubstituted const params)
- #127070 (add () to the marker_impls macro for ConstParamTy)
- #127071 (Remove (deprecated & unstable) {to,from}_bits pointer methods)
- #127078 (Enable full tools and profiler for LoongArch Linux targets)
r? `@ghost`
`@rustbot` modify labels: rollup
Stall computing instance for drop shim until it has no unsubstituted const params
Do not inline the drop shim for types that still have unsubstituted const params.
## Why?
#127030 ICEs because it tries to inline the drop shim for a type with an unsubstituted const param. In order to generate this shim, this requires calling the drop shim builder, which invokes the trait solver to compute whether constituent types need drop (since we compute if a type is copy to disqualify any `Drop` behavior):
9c3bc805dd/compiler/rustc_mir_dataflow/src/elaborate_drops.rs (L378)
However, since we don't keep the param-env of the instance we resolved the item for, we use the wrong param-env:
9c3bc805dd/compiler/rustc_mir_transform/src/shim.rs (L278)
(which is the param-env of `std::ptr::drop_in_place`)
This param-env is notably missing `ConstParamHasTy` predicates, and since we removed the type from consts in https://github.com/rust-lang/rust/pull/125958, we literally cannot prove these predicates in this (relatively) empty param-env. This currently happens in places like the MIR inliner, but may happen elsewhere such as in lints that resolve terminators.
## What?
We force the inliner to not consider calls for `drop_in_place` for types that have unsubstituted const params.
## So what?
This may negatively affect MIR inlining, but I doubt this matters in practice, and fixes a beta regression, so let's fix it. I will look into approaches for fixing this in a more maintainable way, perhaps delaying the creation of drop shim bodies until codegen (like how intrinsics work).
Enable const casting for `f16` and `f128`
I have an open PR to the Miri repo adding tests for this behavior https://github.com/rust-lang/miri/pull/3688, but that unfortunately hits the ICE path here. The changes seem reasonably low risk that it might be okay to merge separately from the tests, and I tested the result locally against an older version of https://github.com/rust-lang/miri/pull/3688.
Cc ``````@RalfJung``````
Switch back `non_local_definitions` lint to allow-by-default
This PR switch back (again) the `non_local_definitions` lint to allow-by-default as T-lang is requesting some (major) changes in the lint inner workings in https://github.com/rust-lang/rust/issues/126768#issuecomment-2192634762.
This PR will need to be beta-backported, as the lint is currently warn-by-default in beta.
Update AST validation module docs
Drive-by doc update for AST validation pass:
- Syntax extensions are replaced by proc macros.
- Add rationale for why AST validation pass need to be run
post-expansion and why the pass is needed in the first place.
This was discussed during this week's [rustc-dev-guide reading club](https://rust-lang.zulipchat.com/#narrow/stream/196385-t-compiler.2Fwg-rustc-dev-guide), and the rationale was explained by cc ``````@bjorn3.``````
Instead of keeping a list of architectures which have native support
for 64-bit atomics, just use #[cfg(target_has_atomic = "64")] and its
inverted counterpart to determine whether we need to use portable
AtomicU64 on the target architecture.
Tighten `fn_decl_span` for async blocks
Tightens the span of `async {}` blocks in diagnostics, and subsequently async closures and async fns, by actually setting the `fn_decl_span` correctly. This is kinda a follow-up on #125078, but it fixes the problem in a more general way.
I think the diagnostics are significantly improved, since we no longer have a bunch of overlapping spans. I'll point out one caveat where I think the diagnostic may get a bit more confusing, but where I don't think it matters.
r? ````@estebank```` or ````@oli-obk```` or someone else on wg-diag or compiler i dont really care lol
Support fetching `Attribute` of items.
Fixes [https://github.com/rust-lang/project-stable-mir/issues/83](https://github.com/rust-lang/project-stable-mir/issues/83)
`rustc_ast::ast::Attribute` doesn't impl `Hash` and `Eq`. Thus it cannot be directly used as key of `IndexMap` in `rustc_smir::rustc_smir::Tables` and we cannot define stable `Attribute` as index to `rustc_ast::ast::Attribute` like `Span` and many other stable definitions.
Since an string (or tokens) and its span contain all info about an attribute, I defined a simple `Attribute` struct on stable side.
I choose to fetch attributes via `tcx::get_attrs_by_path()` due to `get_attrs()` is marked as deprecated and `get_attrs_by_name()` cannot handle name of multiple segments like `rustfmt::skip`.
r? `@celinval`
patchable-function-entry: Add unstable compiler flag and attribute
Tracking issue: #123115
Add the -Z patchable-function-entry compiler flag and the #[patchable_function_entry(prefix_nops = m, entry_nops = n)] attribute.
Rebased and adjusted the canditate implementation to match changes in the RFC.
