Rollup of 6 pull requests
Successful merges:
- rust-lang/rust#141839 (make rust-analyzer use a dedicated build directory)
- rust-lang/rust#146166 (Implement range support in `//@ edition`)
- rust-lang/rust#147259 (cg_llvm: Use helper methods for all calls to `LLVMMDNodeInContext2`)
- rust-lang/rust#147263 (Disable triagebot auto stable-regression compiler backport nominations pending redesign)
- rust-lang/rust#147268 (add arm-maintainers to various targets)
- rust-lang/rust#147270 (Move doc_cfg-specific code into `cfg.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
cg_llvm: Use helper methods for all calls to `LLVMMDNodeInContext2`
Originally I was only planning on extracting an `md_node_in_context` method, but then I noticed that all callers of `LLVMMDNodeInContext2` could be covered by a small number of additional helper methods.
There should be no change in compiler output.
Extending `#[rustc_force_inline]` to be applicable to inherent methods
`#[rustc_force_inline]` is an internal-only attribute similar to `#[inline(always)]` but which emits an error if inlining cannot occur. rustc_force_inline uses the MIR inliner to do this and has limitations on where it can be applied to ensure that an error is always emitted if inlining can't happen (e.g. it can't be applied to trait methods because calls to those can't always be resolved).
`#[rustc_force_inline]` is motivated by AArch64 pointer authentication intrinsics where it is vital for the security properties of these intrinsics that they do not exist in standalone functions that could be used as gadgets in an exploit (if they could, then you could sign whatever pointers you want, for example, which is bad, but if you force inlining, then you can't jump to a reusable function containing only these instructions).
Since its initial implementation, `#[rustc_force_inline]` could only be applied to free functions. This can be relaxed to also allow inherent methods while still preserving the desired properties. In a work-in-progress patch for manual pointer authentication intrinsics, it is useful to introduce types with inherent methods that would need to be force inlined.
r? `@saethlin`
Don't enable shared memory by default with Wasm atomics
This prepares us for a future where LLVM eventually stabilizes the atomics target feature, in which case we don't want to inflate atomics with threads. Otherwise users would be stuck with shared memory even when they don't want it/need it.
### Context
Currently the atomics target features is unstable and can't be used without re-building Std with it (`-Zbuild-std`).
Enabling the atomics target feature automatically enables shared memory.
Shared memory is required to actually allow multi-threading.
However, shared memory comes with a performance overhead when atomic instructions aren't able to be lowered to regular memory access instructions or when interacting with certain Web APIs.
So it is very undesirable to enable shared memory by default for the majority of users.
While it is possible to use atomics without shared memory, the question remains what use-case this scenario has.
The only one I can think of would involve multiple memories, where the main memory remains un-shared but a second shared memory exists. While Rust doesn't support multiple memories, it might be possible with inline assembly (rust-lang/rust#136382).
So alternatively, we might consider *not* enabling atomics by default even when LLVM does. In which case everything would remain the same.
---
This will break current Web multi-threading users. To address this they can add the following `RUSTFLAGS`:
```
-Clink-args=--shared-memory,--max-memory=1073741824,--import-memory,--export=__wasm_init_tls,--export=__tls_size,--export=__tls_align,--export=__tls_base
```
We could add a new experimental flag that enables the right linker arguments for users, but I feel that's not in Rusts scope. Or like suggested before: a Rust-only `threads` target feature.
Addresses rust-lang/rust#77839.
r? ``@alexcrichton``
Tweak handling of "struct like start" where a struct isn't supported
This improves the case where someone tries to write a `match` expr where the patterns have type ascription syntax. Makes them less verbose, by giving up on the first encounter in the block, and makes them more accurate by only treating them as a struct literal if successfully parsed as such.
Before, encountering something like `match a { b:` would confuse the parser and think everything after `match` *must* be a struct, and if it wasn't it would generate a cascade of unnecessary diagnostics.
mbe: Implement `unsafe` attribute rules
This implements `unsafe attr` rules for declarative `macro_rules!` attributes, as specified in [RFC 3697](https://github.com/rust-lang/rfcs/pull/3697).
An invocation of an attribute that uses an `unsafe attr` rule requires the `unsafe(attr(...))` syntax.
An invocation of an attribute that uses an ordinary `attr` rule must *not* use the `unsafe(attr(...))` syntax.
`unsafe` is only supported on an `attr` rule, not any other kind of `macro_rules!` rule.
Tracking issue for `macro_rules!` attributes: https://github.com/rust-lang/rust/issues/143547
Turn ProjectionElem::Subtype into CastKind::Subtype
I noticed that drop elaboration can't, in general, handle `ProjectionElem::SubType`. It creates a disjoint move path that overlaps with other move paths. (`Subslice` does too, and I'm working on a different PR to make that special case less fragile.) If its skipped and treated as the same move path as its parent then `MovePath.place` has multiple possible projections. (It would probably make sense to remove all `Subtype` projections for the canonical place but it doesn't make sense to have this special case for a problem that doesn't actually occur in real MIR.)
The only reason this doesn't break is that `Subtype` is always the sole projection of the local its applied to. For the same reason, it works fine as a `CastKind` so I figured that makes more sense than documenting and validating this hidden invariant.
cc rust-lang/rust#112651, rust-lang/rust#133258
r? Icnr (bc you've been the main person dealing with `Subtype` it looks like)
`LegacyAttr` is only used for builtin attributes, and builtin attributes
have their safety checked by `check_attribute_safety`, so we don't need
to check `unsafety` here.
Rollup of 8 pull requests
Successful merges:
- rust-lang/rust#146593 (Allow specifying multiple bounds for same associated item, except in trait objects)
- rust-lang/rust#147177 ([DebugInfo] Fix MSVC tuple child creation)
- rust-lang/rust#147195 (iter repeat: add tests for new count and last behavior)
- rust-lang/rust#147202 (Swap order of `resolve_coroutine_interiors` and `handle_opaque_type_uses`)
- rust-lang/rust#147204 (Refactor ArrayWindows to use a slice)
- rust-lang/rust#147219 (Add proper error handling for closure in impl)
- rust-lang/rust#147226 (include `outer_inclusive_binder` of pattern types)
- rust-lang/rust#147230 (Fix typo in 'unfulfilled_lint_expectation' to plural)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix autodiff empty ret regression
closes https://github.com/rust-lang/rust/issues/147144
The two gsoc summer projects caused a bit of churn, which was to be expected, especially since we don't run autodiff in CI yet.
This adds a void return testcase that we should have had anyway, and fixes the regression.
r? `@Zalathar` (Just guessing since I've seen you in a few LLVM PRs and Oli is probably still busy. Feel free to reroll!)
remove outdated comment in (inner) `InferCtxt`
This comment seems to have stopped being relevant around 3 years ago after 9f95c605f8. A map? what map? :P
r? `@lcnr`
Rollup of 6 pull requests
Successful merges:
- rust-lang/rust#143069 (Add fast-path for accessing the current thread id)
- rust-lang/rust#146518 (Improve the documentation around `ZERO_AR_DATE`)
- rust-lang/rust#146596 (Add a dummy codegen backend)
- rust-lang/rust#146617 (Don’t suggest foreign `doc(hidden)` types in "the following other types implement trait" diagnostics)
- rust-lang/rust#146635 (cg_llvm: Stop using `as_c_char_ptr` for coverage-related bindings)
- rust-lang/rust#147184 (Fix the bevy implied bounds hack for the next solver)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix the bevy implied bounds hack for the next solver
The diff is trivial, of course, and basically what you already suggested. Mostly dug around a bunch to learn. I hope this is roughly what you had in mind.
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/236.
r? `@lcnr`
cg_llvm: Stop using `as_c_char_ptr` for coverage-related bindings
[As explained by a note in `ffi.rs`](8a1b39995e/compiler/rustc_codegen_llvm/src/llvm/ffi.rs (L4-L11)), passing strings and byte slices through FFI is more convenient if we take advantage of the fact that `*const c_uchar` and `*const c_char` have the same ABI.
Doing so avoids having to rely on a special helper function, since we can just call `as_ptr` instead.
(The same logic applies to every other binding that currently uses the `as_c_char_ptr` helper; I just haven't adjusted all of them yet.)
---
As a drive-by change, this PR also marks some coverage-related FFI bindings as `safe`.
Don’t suggest foreign `doc(hidden)` types in "the following other types implement trait" diagnostics
Fixes https://github.com/rust-lang/rust/issues/132024.
``@rustbot`` label A-diagnostics T-compiler
Add a dummy codegen backend
This allows building a rustc capable of running the frontend without any backend present. While this may not seem all that useful, it allows running the frontend of rustc to report errors or running miri to interpret a program without any backend present. This is useful when you are trying to say run miri in the browser as upstream LLVM can't be compiled for wasm yet. Or to run rustc itself in miri like I did a while ago and caught some UB.
Improve the documentation around `ZERO_AR_DATE`
In particular, document why we don't use the new `-reproducible` flag.
I went through [the source for Apple's old linker](https://github.com/apple-oss-distributions/ld64), and compared the versions with [the mapping to Xcode versions on Wikipedia](https://en.wikipedia.org/wiki/Xcode) to find the relevant Xcode versions for these features.
r? compiler
cg_llvm: Replace enum `MetadataType` with a list of `MetadataKindId` constants
The metadata kind ID values declared in `MetadataType` are not part of the LLVM-C API, and are not machine-checked. If a value that we use ever goes out of sync with LLVM, the resulting bugs could be difficult to track down. And the existing values lack any clear indication of what LLVM declarations they correspond to.
On top of that, we currently have another way of expressing metadata kind IDs in the form of `MetadataKindId`, which creates confusing inconsistency in LLVM bindings.
This PR therefore consolidates all usage of “fixed” metadata kind IDs into one list of `MetadataKindId` constants, which is backed by static assertions in our C++ code that match them up with named anonymous-enum variants in `llvm::LLVMContext`.
Rename various "concrete opaque type" things to say "hidden type"
r? lcnr
I've found "concrete opaque type" terminology to be somewhat confusing as in conversation and when explaining opaque type stuff to people I always just talk about things in terms of hidden types. Also the hidden types of opaques are very much not *concrete* in the same sense that a type without any generic parameters is concrete which is an unfortunate overlap in terminology.
I've tried to update comments to also stop referring to things as concrete opaque types but this is mostly best effort as it difficult to find all such cases amongst the massive amounts of uses of "concrete" or "hidden" across the whole compiler.
cmse: fix 'region variables should not be hashed'
tracking issue: https://github.com/rust-lang/rust/issues/81391
fixes https://github.com/rust-lang/rust/issues/131639
Some background: the `cmse-nonsecure-call` calling convention is used for a call from "secure" to "non-secure" code. To make sure that "non-secure" cannot read any secrets, restrictions are put on the signatures of functions with this calling convention: they can only use 4 arguments for passing arguments, and one register for passing a result. No arguments are passed via the stack, and all other registers are cleared before the call.
We check during `hir_ty_lowering` that the signature follows these rules. We do that by determining and then inspecting the layout of the type. That works well overall, but can run into asserts when the type itself is ill-formed. This PR fixes one such case.
I believe that the fix here, just erasing the regions, is the right shape, but there may be some nuance that I'm missing.
r? types
Point at fn bound that introduced lifetime obligation
The last note is new
```
error[E0597]: `c` does not live long enough
--> $DIR/without-precise-captures-we-are-powerless.rs:19:20
|
LL | fn simple<'a>(x: &'a i32) {
| -- lifetime `'a` defined here
...
LL | let c = async move || { println!("{}", *x); };
| - binding `c` declared here
LL | outlives::<'a>(c());
| ---------------^---
| | |
| | borrowed value does not live long enough
| argument requires that `c` is borrowed for `'a`
LL | outlives::<'a>(call_once(c));
LL | }
| - `c` dropped here while still borrowed
|
note: requirement that `c` is borrowed for `'a` introduced here
--> $DIR/without-precise-captures-we-are-powerless.rs:7:33
|
LL | fn outlives<'a>(_: impl Sized + 'a) {}
| ^^
```
When encountering a `ConstraintCategory::Predicate` in a funtion call, point at the `Span` for that `Predicate` to explain where the lifetime obligation originates from.
CC rust-lang/rust#55307.
