Move more early buffered lints to dyn lint diagnostics
Follow-up to rust-lang/rust#145747.
Presently, it's unclear to me if it's possible to migrate all variants to dyn lint diagnostics without regressing performance because for some early lints `decorate_builtin_lint` performs a bit more work (past PR rust-lang/rust#124417 has shown that eagerly decorating early lints is incredibly heavy and we had to revert back to lazily decorating in rust-lang/rust#125410). Let's see how this fares once I tackle the more 'risky' variants.
cc `@joshtriplett` (you can immediately unsubscribe again, I just want to prevent duplicate efforts).
Some hygiene doc improvements
Improve some doc comments around SyntaxContext, outer_expn and friends.
Based on discussion at https://github.com/rust-lang/rust/pull/146100.
r? petrochenkov
update fixme in compare_method_predicate_entailment resulting from review of EII
r? `@lcnr`
Just the comment update separately from https://github.com/rust-lang/rust/pull/146348/files since it doesn't really belong in that PR. Should be trivial
Make `AssocItem` aware of its impl kind
The general goal is to have fewer query dependencies by making `AssocItem` aware of its parent impl kind (inherent vs. trait) without having to query the parent def_kind.
See individual commits.
Add --print target-spec-json-schema
This schema is helpful for people writing custom target spec JSON. It can provide autocomplete in the editor, and also serves as documentation when there are documentation comments on the structs, as `schemars` will put them in the schema.
I was motivated to do this because I saw someone write their own version of this schema by hand, so demand for this clearly exists. It's not a lot of effort to implement, so I thought it would make sense.
MCP: https://github.com/rust-lang/compiler-team/issues/905
I think it would also be useful to put this in the sysroot in `etc` so people can link it directly in their editors.
I would have loved to add a test that validates the JSON schema against the spec JSON of every builtin target, but I don't want to do it as the JSON schema validation crates have incredible amounts of dependencies because JSON schema supports a ton of random features. I don't want to add that, even as a dev dependency.
Convert `no_std` and `no_core` to the new attribute infrastructure
r? ```@oli-obk```
Also added a test for these, since we didn't have any and I was kind of surprised new diagnostics didn't break anything hehe
This schema is helpful for people writing custom target spec JSON. It
can provide autocomplete in the editor, and also serves as documentation
when there are documentation comments on the structs, as `schemars` will
put them in the schema.
With this macro we only need to enumerate every variant once. This saves
a lot of duplication already between the definition, the `FromStr` impl
and the `ToJson` impl.
It also enables us to do further things with it like JSON schema
generation.
support integer literals in `${concat()}`
Tracking issue: rust-lang/rust#124225
Adds support for using integer literals as arguments to `${concat()}` macro expressions.
Integer formatting such as `1_000` is preserved by this.
match clang's `va_arg` assembly on arm targets
tracking issue: https://github.com/rust-lang/rust/issues/44930
For this example
```rust
#![feature(c_variadic)]
#[unsafe(no_mangle)]
unsafe extern "C" fn variadic(a: f64, mut args: ...) -> f64 {
let b = args.arg::<f64>();
let c = args.arg::<f64>();
a + b + c
}
```
We currently generate (via llvm):
```asm
variadic:
sub sp, sp, #12
stmib sp, {r2, r3}
vmov d0, r0, r1
add r0, sp, #4
vldr d1, [sp, #4]
add r0, r0, #15
bic r0, r0, #7
vadd.f64 d0, d0, d1
add r1, r0, #8
str r1, [sp]
vldr d1, [r0]
vadd.f64 d0, d0, d1
vmov r0, r1, d0
add sp, sp, #12
bx lr
```
LLVM is not doing a good job. In fact, it's well-known that LLVM's implementation of `va_arg` is kind of bad, and we implement it ourselves (based on clang) for many targets already. For arm, our own `emit_ptr_va_arg` saves 3 instructions.
Next, it turns out it's important for LLVM to explicitly start and end the lifetime of the `va_list`. In https://github.com/rust-lang/rust/pull/146059 I already end the lifetime, but when looking at this again, I noticed that it is important to also start it, see https://godbolt.org/z/EGqvKTTsK: failing to explicitly start the lifetime uses an extra register.
So, the combination of `emit_ptr_va_arg` with starting/ending the lifetime makes rustc emit exactly the instructions that clang generates::
```asm
variadic:
sub sp, sp, #12
stmib sp, {r2, r3}
vmov d16, r0, r1
vldr d17, [sp, #4]
vadd.f64 d16, d16, d17
vldr d17, [sp, #12]
vadd.f64 d16, d16, d17
vmov r0, r1, d16
add sp, sp, #12
bx lr
```
The arguments to `emit_ptr_va_arg` are based on [the clang implementation](03dc2a41f3/clang/lib/CodeGen/Targets/ARM.cpp (L798-L844)).
r? ``@workingjubilee`` (I can re-roll if your queue is too full, but you do seem like the right person here)
try-job: armhf-gnu
Skip typeck for items w/o their own typeck context
Skip items which forward typeck to their ancestor.
Should remove some potential but unnecessary typeck query waits, hence might improve performance for the parallel frontend.
Thanks to `@ywxt` for a fix suggestion
Fixesrust-lang/rust#141951
Revert `assert!` desugaring changes (#122661)
Reverts rust-lang/rust#122661 to prevent rust-lang/rust#145770 slipping into beta.
cc `@estebank` (FYI)
### Review remarks
- Commit 1 is the MCVE reported in rust-lang/rust#145770 added as a regression test `tests/ui/macros/assert-desugaring-145770.rs`. Against `master`, this test fails.
- Commit 2 reverts rust-lang/rust#122661 (with a merge conflict fixed). `tests/ui/macros/assert-desugaring-145770.rs` now passes.
Less greedily parse `[const]` bounds
> [!IMPORTANT]
> If you're coming here from any beta backport nomination thread on Zulip, only the last commit is truly relevant (the first commit doesn't need to be backported, it only contains test modifications)!
Don't consider `[` to start a bound, only consider `[const]` in its entirety to do so. This drastically reduces (but doesn't eliminate!) the chance of *real* breakages. Like `const`, `~const` and `async` before, `[const]` unavoidably brings along theoretical breakages, see preexisting tests: `macro-const-trait-bound-theoretical-regression.rs` and `macro-async-trait-bound-theoretical-regression.rs`.
Side note: It's unfortunate that we have to do this but apart from the known fact that MBE hurts forward compatibility, the `[const]` syntax is simply a bit scuffed (also CC'ing https://github.com/rust-lang/rust/issues/146122, section (3)).
Fixes [after beta backport] rust-lang/rust#146417.
* 1st commit: Restore the original test intentions of several preexisting related tests that were unfortunately lost over time
* I've added a bunch of SCREAMING comments to make it less likely to be lost again
* CC PR rust-lang/rust#119099 which added most of these tests
* CC [#144409 (comment)](https://github.com/rust-lang/rust/pull/144409#discussion_r2337587513) for further context (NB: It's not the only PR that negatively affected the test intention)
* 2nd commit: Actually address the regression
r? `@oli-obk` or anyone
This reverts commit 1eeb8e8b15, reversing
changes made to 324bf2b9fd.
Unfortunately the assert desugaring change is not backwards compatible,
see RUST-145770.
Code such as
```rust
#[derive(Debug)]
struct F {
data: bool
}
impl std::ops::Not for F {
type Output = bool;
fn not(self) -> Self::Output { !self.data }
}
fn main() {
let f = F { data: true };
assert!(f);
}
```
would be broken by the assert desugaring change. We may need to land
the change over an edition boundary, or limit the editions that the
desugaring change impacts.
Improve C-variadic error messages: part 2
tracking issue: https://github.com/rust-lang/rust/issues/44930
a reimplementation of https://github.com/rust-lang/rust/pull/143546 that builds on https://github.com/rust-lang/rust/pull/146165.
This PR
- disallows coroutines (e.g. `async fn`) from having a `...` argument
- disallows associated functions (both in traits and standard impl blocks) from having a `...` argument
- splits up a generic "ill-formed C-variadic function" into specific errors about using an incorrect ABI, not specifying an ABI, or missing the unsafe keyword
C-variadic coroutines probably don't make sense? C-variadic functions are for FFI purposes, combining that with async functions seems weird.
For associated functions, we're just cutting scope. It's probably fine, but it's probably better to explicitly allow it. So for now, at least give a more targeted error message.
Made to be reviewed commit-by-commit.
cc `@workingjubilee`
r? compiler
Strip frontmatter in fewer places
* Stop stripping frontmatter in `proc_macro::Literal::from_str` (RUST-146132)
* Stop stripping frontmatter in expr-ctxt (but not item-ctxt!) `include`s (RUST-145945)
* Stop stripping shebang (!) in `proc_macro::Literal::from_str`
* Not a breaking change because it did compare spans already to ensure there wasn't extra whitespace or comments (`Literal::from_str("#!\n0")` already yields `Err(_)` thankfully!)
* Stop stripping frontmatter+shebang inside some rustdoc code where it doesn't make any observable difference (see self review comments)
* (Stop stripping frontmatter+shebang inside internal test code)
Fixes https://github.com/rust-lang/rust/issues/145945.
Fixes https://github.com/rust-lang/rust/issues/146132.
r? fee1-dead
Minor symbol comment fixes.
- The empty symbol is no longer a keyword.
- I don't think any of the special reserved identifiers are used for error recovery.
r? ```@petrochenkov```
Suggest examples of format specifiers in error messages
Format macro now suggests adding `{}` if no formatting specifiers are present. It also gives an example:
```rust
LL | println!("Hello", "World");
| ------- ^^^^^^^ argument never used
| |
| formatting specifier missing
|
= note: format specifiers use curly braces: `{}`
help: consider adding format specifier
|
LL | println!("Hello{}", "World");
| ++
```
When one or more `{}` are present, it doesn't show 'format specifiers use curly braces: `{}`' and example, just small hint on how many you missing:
```rust
LL | println!("list: {}", 1, 2, 3);
| ---------- ^ ^ argument never used
| | |
| | argument never used
| multiple missing formatting specifiers
|
= help: consider adding 2 format specifiers
```
Original issue: rust-lang/rust#68293
Based on discussion in this PR: rust-lang/rust#76443
Let me know if something is missing
default auto traits: use default supertraits instead of `Self: Trait` bounds on associated items
First commit: the motivation has been discussed [here](https://github.com/rust-lang/rust/pull/144679).
Second commit: the only new places where new implicit `DefaultAutoTrait` bounds are generated are supertraits and trait object so `?Trait` syntax should be extended to these places only.
r? `@lcnr`
Trim paths less in MIR dumping
With this PR, the paths MIR dump filters and that are printed at the start of a dump file are no longer trimmed. They don't include the crate that is being compiled, however.
Implement `#[rustc_align_static(N)]` on `static`s
Tracking issue: https://github.com/rust-lang/rust/issues/146177
```rust
#![feature(static_align)]
#[rustc_align_static(64)]
static SO_ALIGNED: u64 = 0;
```
We need a different attribute than `rustc_align` because unstable attributes are tied to their feature (we can't have two unstable features use the same unstable attribute). Otherwise this uses all of the same infrastructure as `#[rustc_align]`.
r? `@traviscross`
