resolve: Simplify built-in macro table
We don't use full `SyntaxExtension`s from the table, only `SyntaxExtensionKind`s, and `Ident` in `register_builtin_macro` always had dummy span. This PR removes unnecessary data from the table and related function signatures.
Noticed when reviewing #80850.
Explain method-call move errors in loops
PR #73708 added a more detailed explanation of move errors that occur
due to a call to a method that takes `self`. This PR extends that logic
to work when a move error occurs due to a method call in the previous
iteration of a loop.
Split a func into cold/hot parts, reducing binary size
I noticed that the Size::bits function is called in many places,
and is inlined into them. On x86_64-pc-windows-msvc, this function
is inlined 527 times, and compiled separately (non-inlined) 3 times.
Each of those inlined calls contains code that panics. This commit
moves the `panic!` call into a separate function and marks that
function with `#[cold]`.
This reduces binary size by 24 KB. Not much, but it's something.
Changes like this often reduce pressure on instruction-caches,
since it reduces the amount of code that is inlined into hot code
paths. Or more precisely, it removes cold code from hot cache lines.
Use correct ABI for wasm32 by default
Introduces `wasm32-unknown-bindgen` for those wishing to use the bindgen compat abi. `wasm32-*` now uses the correct abi by default.
Fixes https://github.com/rustwasm/team/issues/291
The signed LEB128 decoding function used a hardcoded constant of 64
instead of the number of bits in the type of integer being decoded,
which resulted in incorrect results for some inputs. Fix this, make the
decoding more consistent with the unsigned version, and increase the
LEB128 encoding and decoding test coverage.
Reduce a large memory spike that happens during serialization by writing
the incr comp structures to file by way of a fixed-size buffer, rather
than an unbounded vector.
Effort was made to keep the instruction count close to that of the
previous implementation. However, buffered writing to a file inherently
has more overhead than writing to a vector, because each write may
result in a handleable error. To reduce this overhead, arrangements are
made so that each LEB128-encoded integer can be written to the buffer
with only one capacity and error check. Higher-level optimizations in
which entire composite structures can be written with one capacity and
error check are possible, but would require much more work.
The performance is mostly on par with the previous implementation, with
small to moderate instruction count regressions. The memory reduction is
significant, however, so it seems like a worth-while trade-off.
log-color: Detect TTY based on stderr, not stdout
Fixes#78435 (again).
Logging goes to stderr, not stdout, so we should base our automated
detection on stderr instead of stdout.
Thanks to Ralf Jung for noticing and reporting the bug!
r? `@oli-obk`
cc `@RalfJung`
Add ABI argument to `find_mir_or_eval_fn`
Add ABI argument for called function in `find_mir_or_eval_fn` and
`call_extra_fn`. Useful for comparing with expected ABI in interpreters.
Related to [miri/1631](https://github.com/rust-lang/miri/issues/1631)
r? `@RalfJung`
Use standard formatting for "rust-call" ABI message
Nearly all error messages start with a lowercase letter and don't use
articles - instead they refer to the plural case.
resolve: Scope visiting doesn't need an `Ident`
Resolution scope visitor (`fn visit_scopes`) currently takes an `Ident` parameter, but it doesn't need a full identifier, or even its span, it only needs the `SyntaxContext` part.
The `SyntaxContext` part is necessary because scope visitor has to jump to macro definition sites, so it has to be directed by macro expansion information somehow.
I think it's clearer to pass only the necessary part.
Yes, usually visiting happens as a part of an identifier resolution, but in cases like collecting traits in scope (#80765) or collecting typo suggestions that's not the case.
r? `@matthewjasper`
Logging goes to stderr, not stdout, so we should base our automated
detection on stderr instead of stdout.
Thanks to Ralf Jung for noticing and reporting the bug!
Add ABI argument for called function in `find_mir_or_eval_fn` and
`call_extra_fn`. Useful for comparing with expected ABI in interpreters.
Related to [miri/1631](https://github.com/rust-lang/miri/issues/1631)
Allow #[rustc_builtin_macro = "name"]
This adds the option of specifying the name of a builtin macro in the `#[rustc_builtin_macro]` attribute: `#[rustc_builtin_macro = "name"]`.
This makes it possible to have both `std::panic!` and `core::panic!` as a builtin macro, by using different builtin macro names for each. This is needed to implement the edition-specific behaviour of the panic macros of RFC 3007.
Also removes `SyntaxExtension::is_derive_copy`, as the macro name (e.g. `sym::Copy`) is now tracked and provides that information directly.
r? ``@petrochenkov``
Use correct span for structured suggestion
On structured suggestion for `let` -> `const` and `const` -> `let`, use
a proper `Span` and update tests to check the correct application.
Follow up to #80012.
Improve core::ptr::drop_in_place debuginfo
* Use span of the dropped type as function span when possible.
* Rename symbol from `core::ptr::drop_in_place::$hash` to `{{drop}}::<$TYPE>::$hash`.
Fixes#77465
(I haven't yet updated the tests)
Rustdoc: Fix macros 2.0 and built-in derives being shown at the wrong path
Fixes#74355
- ~~waiting on author + draft PR since my code ought to be cleaned up _w.r.t._ the way I avoid the `.unwrap()`s:~~
- ~~dummy items may avoid the first `?`,~~
- ~~but within the module traversal some tests did fail (hence the second `?`), meaning the crate did not possess the exact path of the containing module (`extern` / `impl` blocks maybe? I'll look into that).~~
r? `@jyn514`
Per https://github.com/rust-lang/rust/issues/80832, using
--pretty=expanded and --remap-path-prefix results in an ICE.
This is becasue the session source files table is stored in remapped
form, whereas --pretty-expanded looks up unremapped files. This remaps
the path prefixes before lookup.
Don't mark `force_query_with_job` as `inline(always)`
It's rather large, and using `inline(always)` forces it to be recompiled
in each calling crate. Hopefully this change will help with #65031. I intentionally only removed inline from `force_query_with_job` because the other functions are tiny and I wanted to measure this change on its own.
This may conflict with https://github.com/rust-lang/rust/issues/78780. I am not sure if it will hurt or help.
cc `@cjgillot`
Use an empty `TokenCursorFrame` stack when capturing tokens
We will never need to pop past our starting frame during token
capturing. Using an empty stack allows us to avoid pointless heap
allocations/deallocations.
This makes it possible to have both std::panic and core::panic as a
builtin macro, by using different builtin macro names for each.
Also removes SyntaxExtension::is_derive_copy, as the macro name (e.g.
sym::Copy) is now tracked and provides that information directly.
Make target-cpu=native detect individual features
This PR makes target-cpu=native check for and enable/disable individual features instead of detecting and targeting a CPU by name. This brings the flag's behavior more in line with clang and gcc and ensures that the host actually supports each feature that we are compiling for.
This should resolve issues with miscompilations on e.g. "Haswell" Pentiums and Celerons that lack support for AVX, and also enable support for `aes` on Broadwell processors that support it. It should also resolve issues with failing to detect feature support in newer CPUs that aren't yet known by LLVM (see: #80633).
Fixes#54688Fixes#48464Fixes#38218
We will never need to pop past our starting frame during token
capturing. Using an empty stack allows us to avoid pointless heap
allocations/deallocations.
PR #73708 added a more detailed explanation of move errors that occur
due to a call to a method that takes `self`. This PR extends that logic
to work when a move error occurs due to a method call in the previous
iteration of a loop.
Access query (DepKind) metadata through fields
This refactors the access to query definition metadata (attributes such as eval always, anon, has_params) and loading/forcing functions to generate a number of structs, instead of matching on the DepKind enum. This makes access to the fields cheaper to compile. Using a struct means that finding the metadata for a given query is just an offset away; previously the match may have been compiled to a jump table but likely not completely inlined as we expect here.
A previous attempt explored a similar strategy, but using trait objects in #78314 that proved less effective, likely due to higher overheads due to forcing dynamic calls and poorer cache utilization (all metadata is fairly densely packed with this PR).
Optimize away some `fs::metadata` calls.
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
Make sure rust-call errors occur correctly for traits
Fixes#79669
Adds trait method resolution to the error, and adds UI tests to ensure it doesn't happen again. Opening as draft because I'm getting weird link errors from unrelated code on my machine, and want to see what CI thinks.
On structured suggestion for `let` -> `const` and `const` -> `let`, use
a proper `Span` and update tests to check the correct application.
Follow up to #80012.
rustc_parse: Better spans for synthesized token streams
I think using the nonterminal span for synthesizing its tokens is a better approximation than using `DUMMY_SP` or the attribute span like #79472 did in `expand.rs`.
r? `@Aaron1011`
MIR Inline is incompatible with coverage
Fixes: #80060
Fixed by disabling inlining if `-Zinstrument-coverage` is set.
The PR also adds additional use cases to the coverage test for doctests.
r? `@wesleywiser`
cc: `@tmandry`
Make `ExpnData` fields `krate` and `orig_id` private
These fields are only used by hygiene serialized, and should not be
accessed by anything outside of `rustc_span`.
Optimize DST field access
For
struct X<T: ?Sized>(T)
struct Y<T: ?Sized>(u8, T)
the offset of the unsized field is
0
mem::align_of_val(&self.1)
respectively. This patch changes the expression used to compute these
offsets so that the optimizer can perform this optimization.
Consider
```rust
fn f(x: &X<dyn Any>) -> &dyn Any {
&x.0
}
```
Before:
```asm
test:
movq %rsi, %rdx
movq 16(%rsi), %rax
leaq -1(%rax), %rcx
negq %rax
andq %rcx, %rax
addq %rdi, %rax
retq
```
After:
```asm
test:
movq %rsi, %rdx
movq %rdi, %rax
retq
```
Optimize away a `fs::metadata` call.
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
* Rename `ModuleData.normal_ancestor_id` to `nearest_parent_mod`
`normal_ancestor_id` is a very confusing name if you don't already
understand what it means. Adding docs helps, but using a clearer and
more obvious name is also important.
* Rename `Resolver::nearest_mod_parent` to `nearest_parent_mod`
* Add more docs
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
I noticed that the Size::bits function is called in many places,
and is inlined into them. On x86_64-pc-windows-msvc, this function
is inlined 527 times, and compiled separately (non-inlined) 3 times.
Each of those inlined calls contains code that panics. This commit
moves the `panic!` call into a separate function and marks that
function with `#[cold]`.
This reduces binary size by 24 KB. By itself, that's not a substantial
reduction. However, changes like this often reduce pressure on
instruction-caches, since it reduces the amount of code that is inlined
into hot code paths. Or more precisely, it removes cold code from hot
cache lines. It also removes all conditionals from Size::bits(),
which is called in many places.
Move variable into the only branch where it is relevant
At the `if` branch `filter` (the `let` binding) is `None` iff `filter` (the parameter) was `None`.
We can branch on the parameter, move the binding into the `if`, and the complexity of handling
`Option<Option<_>` largely dissolves.
`@rustbot` modify labels +C-cleanup +T-compiler
Note: I have no idea how hot this code is. If this method frequently gets called with a `None` filter, there might be a small perf improvement.
Add check for `[T;N]`/`usize` mismatch in astconv
Helps clarify the issue in #80506
by adding a specific check for mismatches between [T;N] and usize.
r? `@lcnr`
use PlaceRef more consistently instead of loosely coupled local+projection
Instead of working directly with the `projections` array, use `iter_projections` and `last_projection`. This avoids having to construct new `PlaceRef` from the pieces everywhere.
I only did this for a few files, to see how people think about this. If y'all are happy with this, I'll open an E-mentor issue to complete this. I grepped for `Place::ty_from` to find the places that need adjusting -- this could miss some, but I am not sure what else to grep for.
Add note to non-exhaustive match on reference to empty
Rust prints "type `&A` is non-empty" even is A is empty.
This is the intended behavior, but can be confusing.
This commit adds a note to non-exhaustive pattern errors if they are a
reference to something uninhabited.
I did not add tests to check that the note is not shown for
non-references or inhabited references, because this is already done
in other tests.
Maybe the added test is superfluous, because
`always-inhabited-union-ref` already checks for this case.
This does not handle &&Void or &&&void etc. I could add those as special
cases as well and ignore people who need quadruple
references.
Fixes#78123
Allow references to interior mutable data behind a feature gate
supercedes #80373 by simply not checking for interior mutability on borrows of locals that have `StorageDead` and thus can never be leaked to the final value of the constant
tracking issue: https://github.com/rust-lang/rust/issues/80384
r? `@RalfJung`
Rust prints "type `&A` is non-empty" even is A is empty.
This is the intended behavior, but can be confusing.
This commit adds a note to non-exhaustive pattern errors if they are a
reference to something uninhabited.
I did not add tests to check that the note is not shown for
non-references or inhabited references, because this is already done
in other tests.
Maybe the added test is superfluous, because
`always-inhabited-union-ref` already checks for this case.
This does not handle &&Void or &&&void etc. I could add those as special
cases as well and ignore people who need quadruple
references.
Fixes#78123
Clean up in `each_child_of_item`
This PR hopes to eliminate some of the surprising elements I encountered while reading the function.
- `macros_only` is checked against inside the loop body, but if it is `true`, the loop is skipped anyway
- only query `span` when relevant
- no need to allocate attribute vector
At the `if` branch `filter` (the `let` binding) is `None` iff `filter` (the parameter) was `None`.
We can branch on the parameter, move the binding into the `if`, and the complexity of handling
`Option<Option<_>` largely dissolves.
`const_generics_defaults`: don't ICE in the unimplemented parts
The thought was that we could use `todo!`s to ensure we wouldn't forget to implement parts of the experimental gate.
However, that can also lead to a suboptimal experience for users as shown in #80589 having both the error/warning about the experimental feature, and the ICE.
Fixes#80589
r? `@varkor`
improve unconditional_panic description
The fact that the lint is triggered by the ConstProp pass is an implementation detail, I do not think that this should be mentioned in the description.
Cc `@oli-obk` `@ehuss`
rustc_serialize: specialize opaque encoding and decoding of some u8 sequences
This specializes encoding and decoding of some contiguous u8 sequences to use a more efficient implementation. The default implementations process each u8 individually, but that isn't necessary for the opaque encoder and decoder. The opaque encoding for u8s is a no-op, so we can just copy entire sequences as-is, rather than process them byte by byte.
This also changes some encode and decode implementations for contiguous sequences to forward to the slice and vector implementations, so that they can take advantage of the new specialization when applicable.
Enable ASan, TSan, UBSan for aarch64-apple-darwin.
I confirmed ASan, TSan, UBSan all work for me locally with `clang` on my new Macbook Air.
~This requires https://github.com/rust-lang/llvm-project/pull/86~
- Adds optional default values to const generic parameters in the AST
and HIR
- Parses these optional default values
- Adds a `const_generics_defaults` feature gate
Add edition 2021.
🎆 Happy new ~~year~~ Rust. 🍾
This adds --edition=2021, and updates suggestions about 2018 to say "2018 *or later*".
Related Cargo PR: https://github.com/rust-lang/cargo/pull/8922
---
Edit: This adds the new edition as *unstable*. Without `-Z unstable-options`, `--edition=2021` results in:
```
$ rustc --edition=2021
error: edition 2021 is unstable and only available with -Z unstable-options.
```
Update and improve `rustc_codegen_{llvm,ssa}` docs
Fixes#75342.
These docs were very out of date and misleading. They even said that
they codegen'd the *AST*!
For some reason, the `rustc_codegen_ssa::base` docs were exactly
identical to the `rustc_codegen_llvm::base` docs. They didn't really
make sense, because they had LLVM-specific information even though
`rustc_codegen_ssa` is supposed to be somewhat generic. So I removed
them as they were misleading.
r? ``@pnkfelix`` maybe?
Add `#[track_caller]` to `bug!` and `register_renamed`
Before:
```
thread 'rustc' panicked at 'compiler/rustc_lint/src/context.rs:267:18: invalid lint renaming of broken_intra_doc_links to rustdoc::broken_intra_doc_links', compiler/rustc_middle/src/util/bug.rs:34:26
```
After:
```
thread 'rustc' panicked at 'src/librustdoc/core.rs:455:24: invalid lint renaming of broken_intra_doc_links to rustdoc::broken_intra_doc_links', compiler/rustc_middle/src/util/bug.rs:35:26
```
The reason I added it to `register_renamed` too is that any panic in
that function will be the caller's fault.
Rollup of 9 pull requests
Successful merges:
- #78934 (refactor: removing library/alloc/src/vec/mod.rs ignore-tidy-filelength)
- #79479 (Add `Iterator::intersperse`)
- #80128 (Edit rustc_ast::ast::FieldPat docs)
- #80424 (Don't give an error when creating a file for the first time)
- #80458 (Some Promotion Refactoring)
- #80488 (Do not create dangling &T in Weak<T>::drop)
- #80491 (Miri: make size/align_of_val work for dangling raw ptrs)
- #80495 (Rename kw::Invalid -> kw::Empty)
- #80513 (Add regression test for #80062)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Some Promotion Refactoring
Clean up promotion a bit:
* factor out some common code
* more exhaustive matches
This *should* not break anything... the only potentially-breaking change is that `BorrowKind::Shallow | BorrowKind::Unique` are now rejected for internal references.
r? ``@oli-obk``
Rollup of 7 pull requests
Successful merges:
- #80185 (Fix ICE when pointing at multi bytes character)
- #80260 (slightly more typed interface to panic implementation)
- #80311 (Improvements to NatVis support)
- #80337 (Use `desc` as a doc-comment for queries if there are no doc comments)
- #80381 (Revert "Cleanup markdown span handling")
- #80492 (remove empty wraps, don't return Results from from infallible functions)
- #80509 (where possible, pass slices instead of &Vec or &String (clippy::ptr_arg))
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
remove empty wraps, don't return Results from from infallible functions
This makes code easier to understand because it is more obvious when a function actually can't fail (return Err or None)
Make functions that only ever return Some(x), return x directly
Remove return type from functions that return Option<(), Err> but would only ever return Ok(()).
Found with `clippy::unnecessary_wraps`
remove unused return type of dropck::check_drop_obligations()
don't wrap return type in Option in get_macro_by_def_id() since we would always return Some(..)
remove redundant return type of back::write::optimize()
don't Option-wrap return type of compute_type_parameters() since we always return Some(..)
don't return empty Result in assemble_generator_candidates()
don't return empty Result in assemble_closure_candidates()
don't return empty result in assemble_fn_pointer_candidates()
don't return empty result in assemble_candidates_from_impls()
don't return empty result in assemble_candidates_from_auto_impls()
don't return emtpy result in assemble_candidates_for_trait_alias()
don't return empty result in assemble_builtin_bound_candidates()
don't return empty results in assemble_extension_candidates_for_traits_in_scope() and assemble_extension_candidates_for_trait()
remove redundant wrapping of return type of StripItem::strip() since it always returns Some(..)
remove unused return type of assemble_extension_candidates_for_all_traits()
Edit rustc_span documentation
Various changes to the `rustc_span` docs, including the following:
- Additions to top-level docs
- Edits to the source_map module docs
- Edits to documentation for `Span` and `SpanData`
- Added intra-docs links
- Documentation for Levenshtein distances
- Fixed missing punctuation
Lint on redundant trailing semicolon after item
We now lint on code like this:
```rust
fn main() {
fn foo() {};
struct Bar {};
}
```
Previously, this caused warnings in Cargo, so it was disabled.
Replace pretty-print/compare/retokenize hack with targeted workarounds
Based on https://github.com/rust-lang/rust/pull/78296
cc https://github.com/rust-lang/rust/issues/43081
The 'pretty-print/compare/retokenize' hack is used to try to avoid passing an outdated `TokenStream` to a proc-macro when the underlying AST is modified in some way (e.g. cfg-stripping before derives). Unfortunately, retokenizing throws away spans (including hygiene information), which causes issues of its own. Every improvement to the accuracy of the pretty-print/retokenize comparison has resulted in non-trivial ecosystem breakage due to hygiene changes. In extreme cases, users deliberately wrote unhygienic `macro_rules!` macros (likely because they did not realize that the compiler's behavior was a bug).
Additionaly, the comparison between the original and pretty-printed/retoknized token streams comes at a non-trivial runtime cost, as shown by https://github.com/rust-lang/rust/pull/79338
This PR removes the pretty-print/compare/retokenize logic from `nt_to_tokenstream`. We only discard the original `TokenStream` under two circumstances:
* Inner attributes are used (detected by examining the AST)
* `cfg`/`cfg_attr` processing modifies the AST. This is detected by making the visitor update a flag when it performs a modification, instead of trying to detect the modification after-the-fact. Note that a 'matching' `cfg` (e.g. `#[cfg(not(FALSE)]`) does not actually get removed from the AST, allowing us to preserve the original `TokenStream`.
In all other cases, we preserve the original `TokenStream`.
This could use a bit of refactoring/renaming - opening for a Crater run.
r? `@ghost`
Before:
```
thread 'rustc' panicked at 'compiler/rustc_lint/src/context.rs:267:18: invalid lint renaming of broken_intra_doc_links to rustdoc::broken_intra_doc_links', compiler/rustc_middle/src/util/bug.rs:34:26
```
After:
```
thread 'rustc' panicked at 'src/librustdoc/core.rs:455:24: invalid lint renaming of broken_intra_doc_links to rustdoc::broken_intra_doc_links', compiler/rustc_middle/src/util/bug.rs:35:26
```
The reason I added it to `register_renamed` too is that any panic in
that function will be the caller's fault.
- Replace {} with the stringified expr
Giant thank you to `@danielhenrymantilla` for figuring out how to make
this work ❤️
- Note that this is just an approximation and it would be better to add
a doc-comment
Document `InferTy` & co.
I finally figured out what `TyVid` means! The name is quite opaque, so I
decided to document it and related types.
I don't know that much about `InferTy` & co., but I was able to *infer*
( :) ) from the names and what I know generally about type inference to
add some basic documentation.
Rollup of 11 pull requests
Successful merges:
- #79662 (Move some more code out of CodegenBackend::{codegen_crate,link})
- #79815 (Update RELEASES.md for 1.49.0)
- #80284 (Suggest fn ptr rather than fn item and suggest to use `Fn` trait bounds rather than the unique closure type in E0121)
- #80331 (Add more comments to trait queries)
- #80344 (use matches!() macro in more places)
- #80353 (BTreeMap: test split_off (and append) more thoroughly)
- #80362 (Document rustc_macros on nightly-rustc)
- #80399 (Remove FIXME in rustc_privacy)
- #80408 (Sync rustc_codegen_cranelift)
- #80411 (rustc_span: Remove `Symbol::with`)
- #80434 (bootstrap: put the component name in the tarball temp dir path)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Sync rustc_codegen_cranelift
The highlight of this sync are two JIT mode improvements. The first is that it is now possible to use JIT mode when using `-Zcodegen-backend` instead of the custom driver using `-Cllvm-args=mode=jit`. The second one is a new JIT mode that lazily compiles functions when they are called the first time: https://github.com/bjorn3/rustc_codegen_cranelift/pull/1120
In addition this includes a few small runtime performance improvements and various fixes for rustc changes that didn't cause compilation to fail.
r? ``@ghost``
``@rustbot`` label +A-codegen +A-cranelift +T-compiler
Suggest fn ptr rather than fn item and suggest to use `Fn` trait bounds rather than the unique closure type in E0121
Previously, using `_` as a return type in a function that returned a function/closure would provide a diagnostic that would cause a papercut. For example:
```rust
fn f() -> i32 { 0 }
fn fn_ptr() -> _ { f }
fn closure() -> _ { || 0 }
```
would result in this diagnostic:
```rust
error[E0121]: the type placeholder `_` is not allowed within types on item signatures
--> <anon>:2:16
|
2 | fn fn_ptr() -> _ { f }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `fn() -> i32 {f}`
error[E0121]: the type placeholder `_` is not allowed within types on item signatures
--> <anon>:3:17
|
3 | fn closure() -> _ { || 0 }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `[closure@<anon>:3:21: 3:25]`
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0121`.
```
As can be seen, it was suggested to use the function definition return type `fn() -> i32 { f }` which is not valid syntax as a return type. Additionally, closures cause a papercut as unique closure types (notated in this case as `[closure@<anon>:3:21: 3:25]`) are not valid syntax either.
Instead, this PR implements this version of the diagnostic (this example is for the same code featured above):
```rust
error[E0121]: the type placeholder `_` is not allowed within types on item signatures
--> <anon>:2:16
|
2 | fn fn_ptr() -> _ { f }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `fn() -> i32`
error[E0121]: the type placeholder `_` is not allowed within types on item signatures
--> <anon>:3:17
|
3 | fn closure() -> _ { || 0 }
| ^ not allowed in type signatures
|
= help: consider using an `Fn`, `FnMut`, or `FnOnce` trait bound
= note: for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0121`.
```
As can be seen in this diagnostic, the papercut for returning a function item is fixed by suggesting the usage of a function pointer as the return type. As for closures, it's suggested to use an `Fn`, `FnMut`, or `FnOnce` trait bound (with further reading on closures and `Fn` traits in *The Book* for beginners). I did not implement a suggestion to use `impl Fn() -> i32` syntax as that was out-of-scope for my abilities at the moment, therefore someone in the future may want to implement that. Also, it's possible to use either `impl Trait` syntax, generics, or generics with a `where` clause, and some users may not want to use `impl Trait` syntax for their own reasons.
This PR fixes#80179.
Prevent caching normalization results with a cycle
When normalizing a projection which results in a cycle, we would cache the result of `project_type` without the nested obligations (because they're not needed for inference). This would result in the nested obligations only being handled once in fulfill, which would avoid the cycle error. `get_paranoid_cache_value_obligation` used to add an obligation that resulted in a cycle in this case previously, but was removed by #73905.
This PR makes the projection cache not cache the value of a projection if it was ever normalized in a cycle (except in a snapshot that's rolled back).
Fixes#79714.
r? `@nikomatsakis`
Various changes to the `rustc_span` docs, including the following:
- Additions to top-level docs
- Edits to the source_map module docs
- Edits to documentation for `Span` and `SpanData`
- Added intra-docs links
- Documentation for Levenshtein distances
- Fixed missing punctuation
validate promoteds
Turn on const-value validation for promoteds. This is made possible now that https://github.com/rust-lang/rust/issues/67534 is resolved.
I don't think this is a breaking change. We don't promote any unsafe operation any more (since https://github.com/rust-lang/rust/pull/77526 landed). We *do* promote `const fn` calls under some circumstances (in `const`/`static` initializers), but union field access and similar operations are not allowed in `const fn`. So now is a perfect time to add this check. :D
r? `@oli-obk`
Fixes https://github.com/rust-lang/rust/issues/67465
Exclude unnecessary info from CodegenResults
`foreign_module` and `wasm_import_module` are not needed for linking, and hence can be removed from CodegenResults.
Fixes#77857
Rename rustc_middle::lint::LintSource
Rename [`rustc_middle::lint::LintSource`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/lint/enum.LintSource.html) to `rustc_middle::lint::LintLevelSource`.
This enum represents the source of a *lint level*, not a lint. This should improve code readability.
Update: Also documents `rustc_middle::lint::LevelSource` to clarify.
Implemented a compiler diagnostic for move async mistake
Fixes#79694
First time contributing, so I hope I'm doing everything right.
(If not, please correct me!)
This code performs a check when a move capture clause is parsed. The check is to detect if the user has reversed the async move keywords and to provide a diagnostic with a suggestion to fix it.
Checked code:
```rust
fn main() {
move async { };
}
```
Previous output:
```txt
PS C:\Repos\move_async_test> cargo build
Compiling move_async_test v0.1.0 (C:\Repos\move_async_test)
error: expected one of `|` or `||`, found keyword `async`
--> src\main.rs:2:10
|
2 | move async { };
| ^^^^^ expected one of `|` or `||`
error: aborting due to previous error
error: could not compile `move_async_test`
```
New output:
```txt
PS C:\Repos\move_async_test> cargo +dev build
Compiling move_async_test v0.1.0 (C:\Repos\move_async_test)
error: the order of `move` and `async` is incorrect
--> src\main.rs:2:13
|
2 | let _ = move async { };
| ^^^^^^^^^^
|
help: try switching the order
|
2 | let _ = async move { };
| ^^^^^^^^^^
error: aborting due to previous error
error: could not compile `move_async_test`
```
Is there a file/module where these kind of things are tested?
Would love some feedback 😄
Remap instrument-coverage line numbers in doctests
This uses the `SourceMap::doctest_offset_line` method to re-map line
numbers from doctests. Remapping columns is not yet done, and rustdoc
still does not output the correct filename when running doctests in a
workspace.
Part of #79417 although I dont consider that fixed until both filenames
and columns are mapped correctly.
r? `@richkadel`
I might jump on zulip the comming days. Still need to figure out how to properly write tests for this, and deal with other doctest issues in the meantime.
Rework beautify_doc_string so that it returns a Symbol instead of a String
This commit comes from https://github.com/rust-lang/rust/pull/80261, the goal here is to inspect the impact on performance of this change on its own.
The idea of rewriting `beautify_doc_string` is to not go through `String` if we don't need to update the doc comment to be able to keep the original `Symbol` and also to have better performance.
r? `@jyn514`
rustc_query_system: reduce dependency graph memory usage
This change implements, at a high level, two space optimizations to the dependency graph.
The first optimization is sharing graph data with the previous dependency graph. Whenever we intern a node, we know whether that node is new (not in the previous graph) or not, and if not, the color of the node in the previous graph.
Red and green nodes have their `DepNode` present in the previous graph, so for that piece of node data, we can just store the index of the node in the previous graph rather than duplicate the `DepNode`. Green nodes additionally have the the same result `Fingerprint`, so we can avoid duplicating that too. Finally, we distinguish between "light" and "dark" green nodes, where the latter are nodes that were marked green because all of their dependencies were marked green. These nodes can additionally share edges with the previous graph, because we know that their set of dependencies is the same (technically, light green and red nodes can have the same dependencies too, but we don't try to figure out whether or not that's the case).
Also, some effort is made to pack data tightly, and to avoid storing `DepNode`s as map keys more than once.
The second optimization is storing edges in a more compact representation, as in the `SerializedDepGraph`, that is, in a single vector, rather than one `EdgesVec` per node. An `EdgesVec` is a `SmallVec` with an inline buffer for 8 elements. Each `EdgesVec` is, at minimum, 40 bytes, and has a per-node overhead of up to 40 bytes. In the ideal case of exactly 8 edges, then 32 bytes are used for edges, and the overhead is 8 bytes. But most of the time, the overhead is higher.
In contrast, using a single vector to store all edges, and having each node specify its start and end elements as 4 byte indices into the vector has a constant overhead of 8 bytes--the best case scenario for the per-node `EdgesVec` approach.
The downside of this approach is that `EdgesVec`s built up during query execution have to be copied into the vector, whereas before, we could just take ownership over them. However, we mostly make up for this because the single vector representation enables a more efficient implementation of `DepGraph::serialize`.
