includes post-developed commit: do not suggest internal-only keywords as corrections to parse failures.
includes post-developed commit: removed tabs that creeped in into rustfmt tool source code.
includes post-developed commit, placating rustfmt self dogfooding.
includes post-developed commit: add backquotes to prevent markdown checking from trying to treat an attr as a markdown hyperlink/
includes post-developed commit: fix lowering to keep contracts from being erroneously inherited by nested bodies (like closures).
Rebase Conflicts:
- compiler/rustc_parse/src/parser/diagnostics.rs
- compiler/rustc_parse/src/parser/item.rs
- compiler/rustc_span/src/hygiene.rs
Remove contracts keywords from diagnostic messages
Autodiff Upstreaming - rustc_codegen_ssa, rustc_middle
This PR should not be merged until the rustc_codegen_llvm part is merged.
I will also alter it a little based on what get's shaved off from the cg_llvm PR,
and address some of the feedback I received in the other PR (including cleanups).
I am putting it already up to
1) Discuss with `@jieyouxu` if there is more work needed to add tests to this and
2) Pray that there is someone reviewing who can tell me why some of my autodiff invocations get lost.
Re 1: My test require fat-lto. I also modify the compilation pipeline. So if there are any other llvm-ir tests in the same compilation unit then I will likely break them. Luckily there are two groups who currently have the same fat-lto requirement for their GPU code which I have for my autodiff code and both groups have some plans to enable support for thin-lto. Once either that work pans out, I'll copy it over for this feature. I will also work on not changing the optimization pipeline for functions not differentiated, but that will require some thoughts and engineering, so I think it would be good to be able to run the autodiff tests isolated from the rest for now. Can you guide me here please?
For context, here are some of my tests in the samples folder: https://github.com/EnzymeAD/rustbook
Re 2: This is a pretty serious issue, since it effectively prevents publishing libraries making use of autodiff: https://github.com/EnzymeAD/rust/issues/173. For some reason my dummy code persists till the end, so the code which calls autodiff, deletes the dummy, and inserts the code to compute the derivative never gets executed. To me it looks like the rustc_autodiff attribute just get's dropped, but I don't know WHY? Any help would be super appreciated, as rustc queries look a bit voodoo to me.
Tracking:
- https://github.com/rust-lang/rust/issues/124509
r? `@jieyouxu`
remove support for the (unstable) #[start] attribute
As explained by `@Noratrieb:`
`#[start]` should be deleted. It's nothing but an accidentally leaked implementation detail that's a not very useful mix between "portable" entrypoint logic and bad abstraction.
I think the way the stable user-facing entrypoint should work (and works today on stable) is pretty simple:
- `std`-using cross-platform programs should use `fn main()`. the compiler, together with `std`, will then ensure that code ends up at `main` (by having a platform-specific entrypoint that gets directed through `lang_start` in `std` to `main` - but that's just an implementation detail)
- `no_std` platform-specific programs should use `#![no_main]` and define their own platform-specific entrypoint symbol with `#[no_mangle]`, like `main`, `_start`, `WinMain` or `my_embedded_platform_wants_to_start_here`. most of them only support a single platform anyways, and need cfg for the different platform's ways of passing arguments or other things *anyways*
`#[start]` is in a super weird position of being neither of those two. It tries to pretend that it's cross-platform, but its signature is a total lie. Those arguments are just stubbed out to zero on ~~Windows~~ wasm, for example. It also only handles the platform-specific entrypoints for a few platforms that are supported by `std`, like Windows or Unix-likes. `my_embedded_platform_wants_to_start_here` can't use it, and neither could a libc-less Linux program.
So we have an attribute that only works in some cases anyways, that has a signature that's a total lie (and a signature that, as I might want to add, has changed recently, and that I definitely would not be comfortable giving *any* stability guarantees on), and where there's a pretty easy way to get things working without it in the first place.
Note that this feature has **not** been RFCed in the first place.
*This comment was posted [in May](https://github.com/rust-lang/rust/issues/29633#issuecomment-2088596042) and so far nobody spoke up in that issue with a usecase that would require keeping the attribute.*
Closes https://github.com/rust-lang/rust/issues/29633
try-job: x86_64-gnu-nopt
try-job: x86_64-msvc-1
try-job: x86_64-msvc-2
try-job: test-various
Account for C string literals and `format_args` in `HiddenUnicodeCodepoints` lint
This is stacked on #134955, and either that can land first or both of them can land together here. I split this out because this is a bit more involved of an impl.
Fixes#94945
Precedence improvements: closures and jumps
This PR fixes some cases where rustc's pretty printers would redundantly parenthesize expressions that didn't need it.
<table>
<tr><th>Before</th><th>After</th></tr>
<tr><td><code>return (|x: i32| x)</code></td><td><code>return |x: i32| x</code></td></tr>
<tr><td><code>(|| -> &mut () { std::process::abort() }).clone()</code></td><td><code>|| -> &mut () { std::process::abort() }.clone()</code></td></tr>
<tr><td><code>(continue) + 1</code></td><td><code>continue + 1</code></td></tr>
</table>
Tested by `echo "fn main() { let _ = $AFTER; }" | rustc -Zunpretty=expanded /dev/stdin`.
The pretty-printer aims to render the syntax tree as it actually exists in rustc, as faithfully as possible, in Rust syntax. It can insert parentheses where forced by Rust's grammar in order to preserve the meaning of a macro-generated syntax tree, for example in the case of `a * $rhs` where $rhs is `b + c`. But for any expression parsed from source code, without a macro involved, there should never be a reason for inserting additional parentheses not present in the original.
For closures and jumps (return, break, continue, yield, do yeet, become) the unneeded parentheses came from the precedence of some of these expressions being misidentified. In the same order as the table above:
- Jumps and closures are supposed to have equal precedence. The [Rust Reference](https://doc.rust-lang.org/1.83.0/reference/expressions.html#expression-precedence) says so, and in Syn they do. There is no Rust syntax that would require making a precedence distinction between jumps and closures. But in rustc these were previously 2 distinct levels with the closure being lower, hence the parentheses around a closure inside a jump (but not a jump inside a closure).
- When a closure is written with an explicit return type, the grammar [requires](https://doc.rust-lang.org/1.83.0/reference/expressions/closure-expr.html) that the closure body consists of exactly one block expression, not any other arbitrary expression as usual for closures. Parsing of the closure body does not continue after the block expression. So in `|| { 0 }.clone()` the clone is inside the closure body and applies to `{ 0 }`, whereas in `|| -> _ { 0 }.clone()` the clone is outside and applies to the closure as a whole.
- Continue never needs parentheses. It was previously marked as having the lowest possible precedence but it should have been the highest, next to paths and loops and function calls, not next to jumps.
Overhaul keyword handling
The compiler's list of keywords has some problems.
- It contains several items that aren't keywords.
- The order isn't quite right in a couple of places.
- Some of the names of predicates relating to keywords are confusing.
- rustdoc and rustfmt have their own (incorrect) versions of the keyword list.
- `AllKeywords` is unnecessarily complex.
r? ```@jieyouxu```
`rustc_symbol` is the source of truth for keywords.
rustdoc has its own implicit definition of keywords, via the
`is_doc_keyword`. It (presumably) intends to include all keywords, but
it omits `yeet`.
rustfmt has its own explicit list of Rust keywords. It also (presumably)
intends to include all keywords, but it omits `await`, `builtin`, `gen`,
`macro_rules`, `raw`, `reuse`, `safe`, and `yeet`. Also, it does linear
searches through this list, which is inefficient.
This commit fixes all of the above problems by introducing a new
predicate `is_any_keyword` in rustc and using it in rustdoc and rustfmt.
It documents that it's not the right predicate in most cases.
`rustc_span::symbol` defines some things that are re-exported from
`rustc_span`, such as `Symbol` and `sym`. But it doesn't re-export some
closely related things such as `Ident` and `kw`. So you can do `use
rustc_span::{Symbol, sym}` but you have to do `use
rustc_span::symbol::{Ident, kw}`, which is inconsistent for no good
reason.
This commit re-exports `Ident`, `kw`, and `MacroRulesNormalizedIdent`,
and changes many `rustc_span::symbol::` qualifiers in `compiler/` to
`rustc_span::`. This is a 200+ net line of code reduction, mostly
because many files with two `use rustc_span` items can be reduced to
one.
- Move it to `rustc_parse`, which is the only crate that uses it. This
lets us remove all the `pub` markers from it.
- Change `next_ref` and `look_ahead` to `get` and `bump`, which work
better for the `rustc_parse` uses.
- This requires adding a `TokenStream::get` method, which is simple.
- In `TokenCursor`, we currently duplicate the
`DelimSpan`/`DelimSpacing`/`Delimiter` from the surrounding
`TokenTree::Delimited` in the stack. This isn't necessary so long as
we don't prematurely move past the `Delimited`, and is a small perf
win on a very hot code path.
- In `parse_token_tree`, we clone the relevant `TokenTree::Delimited`
instead of constructing an identical one from pieces.
Currently there are two ways to peek at a `TokenStreamIter`.
- Wrap it in a `Peekable` and use that traits `peek` method.
- Use `TokenStreamIter`'s inherent `peek` method.
Some code uses one, some use the other. This commit converts all places
to the inherent method. This eliminates mixing of `TokenStreamIter` and
`Peekable<TokenStreamIter>` and some use of `impl Iterator` and `dyn
Iterator`.
Because `TokenStreamIter` is a much better name for a `TokenStream`
iterator. Also rename the `TokenStream::trees` method as
`TokenStream::iter`, and some local variables.
Keep track of patterns that could have introduced a binding, but didn't
When we recover from a pattern parse error, or a pattern uses `..`, we keep track of that and affect resolution error for missing bindings that could have been provided by that pattern. We differentiate between `..` and parse recovery. We silence resolution errors likely caused by the pattern parse error.
```
error[E0425]: cannot find value `title` in this scope
--> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:18:30
|
LL | if let Website { url, .. } = website {
| ------------------- this pattern doesn't include `title`, which is available in `Website`
LL | println!("[{}]({})", title, url);
| ^^^^^ not found in this scope
```
Fix#74863.
When we recover from a pattern parse error, or a pattern uses `..`, we keep track of that and affect resolution error for missing bindings that could have been provided by that pattern. We differentiate between `..` and parse recovery. We silence resolution errors likely caused by the pattern parse error.
```
error[E0425]: cannot find value `title` in this scope
--> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:19:30
|
LL | println!("[{}]({})", title, url);
| ^^^^^ not found in this scope
|
note: `Website` has a field `title` which could have been included in this pattern, but it wasn't
--> $DIR/struct-pattern-with-missing-fields-resolve-error.rs:17:12
|
LL | / struct Website {
LL | | url: String,
LL | | title: Option<String> ,
| | ----- defined here
LL | | }
| |_-
...
LL | if let Website { url, .. } = website {
| ^^^^^^^^^^^^^^^^^^^ this pattern doesn't include `title`, which is available in `Website`
```
Fix#74863.
Add AST support for unsafe binders
I'm splitting up #130514 into pieces. It's impossible for me to keep up with a huge PR like that. I'll land type system support for this next, probably w/o MIR lowering, which will come later.
r? `@oli-obk`
cc `@BoxyUwU` and `@lcnr` who also may want to look at this, though this PR doesn't do too much yet
Keep track of parse errors in `mod`s and don't emit resolve errors for paths involving them
When we expand a `mod foo;` and parse `foo.rs`, we now track whether that file had an unrecovered parse error that reached the end of the file. If so, we keep that information around in the HIR and mark its `DefId` in the `Resolver`. When resolving a path like `foo::bar`, we do not emit any errors for "`bar` not found in `foo`", as we know that the parse error might have caused `bar` to not be parsed and accounted for.
When this happens in an existing project, every path referencing `foo` would be an irrelevant compile error. Instead, we now skip emitting anything until `foo.rs` is fixed. Tellingly enough, we didn't have any test for errors caused by expansion of `mod`s with parse errors.
Fix https://github.com/rust-lang/rust/issues/97734.
When we expand a `mod foo;` and parse `foo.rs`, we now track whether that file had an unrecovered parse error that reached the end of the file. If so, we keep that information around. When resolving a path like `foo::bar`, we do not emit any errors for "`bar` not found in `foo`", as we know that the parse error might have caused `bar` to not be parsed and accounted for.
When this happens in an existing project, every path referencing `foo` would be an irrelevant compile error. Instead, we now skip emitting anything until `foo.rs` is fixed. Tellingly enough, we didn't have any test for errors caused by `mod` expansion.
Fix#97734.
Initial implementation of `#[feature(default_field_values]`, proposed in https://github.com/rust-lang/rfcs/pull/3681.
Support default fields in enum struct variant
Allow default values in an enum struct variant definition:
```rust
pub enum Bar {
Foo {
bar: S = S,
baz: i32 = 42 + 3,
}
}
```
Allow using `..` without a base on an enum struct variant
```rust
Bar::Foo { .. }
```
`#[derive(Default)]` doesn't account for these as it is still gating `#[default]` only being allowed on unit variants.
Support `#[derive(Default)]` on enum struct variants with all defaulted fields
```rust
pub enum Bar {
#[default]
Foo {
bar: S = S,
baz: i32 = 42 + 3,
}
}
```
Check for missing fields in typeck instead of mir_build.
Expand test with `const` param case (needs `generic_const_exprs` enabled).
Properly instantiate MIR const
The following works:
```rust
struct S<A> {
a: Vec<A> = Vec::new(),
}
S::<i32> { .. }
```
Add lint for default fields that will always fail const-eval
We *allow* this to happen for API writers that might want to rely on users'
getting a compile error when using the default field, different to the error
that they would get when the field isn't default. We could change this to
*always* error instead of being a lint, if we wanted.
This will *not* catch errors for partially evaluated consts, like when the
expression relies on a const parameter.
Suggestions when encountering `Foo { .. }` without `#[feature(default_field_values)]`:
- Suggest adding a base expression if there are missing fields.
- Suggest enabling the feature if all the missing fields have optional values.
- Suggest removing `..` if there are no missing fields.
Fix MutVisitor's default implementations to visit Stmt's and BinOp's spans
The `Stmt` case is a bug introduced almost certainly unintentionally by https://github.com/rust-lang/rust/pull/126993. The code _used_ to visit and mutate `span` correctly, but got changed as follows by that PR. Notice how `span` is **copied** into the output by `|kind| Stmt { id, kind, span }` which happens after the mutation in the correct code (red) and before the mutation in the incorrect code (green).
```diff
pub fn noop_flat_map_stmt<T: MutVisitor>(
Stmt { kind, mut span, mut id }: Stmt,
vis: &mut T,
) -> SmallVec<[Stmt; 1]> {
vis.visit_id(&mut id);
- vis.visit_span(&mut span);
let stmts: SmallVec<_> = noop_flat_map_stmt_kind(kind, vis)
.into_iter()
.map(|kind| Stmt { id, kind, span })
.collect();
if stmts.len() > 1 {
panic!(...);
}
+ vis.visit_span(&mut span);
stmts
}
```
