Remove some unused ordering derivations based on `DefId`
Like #93018, this removes some unused/unneeded ordering derivations as part of ongoing work on #90317. Here, these changes are aimed at making https://github.com/rust-lang/rust/pull/90749 easier to review, test, and merge.
r? `@cjgillot`
Move expr- and item-related pretty printing functions to modules
Currently *compiler/rustc_ast_pretty/src/pprust/state.rs* is 2976 lines on master. The `tidy` limit is 3000, which is blocking #92243.
This PR adds a `mod expr;` and `mod item;` to move logic related to those AST nodes out of the single huge file.
Use iterator instead of recursion in `codegen_place`
This PR fixes the FIXME in `codegen_place` about using iterator instead of recursion when processing the `projection` field in `mir::PlaceRef`. At the same time, it also reduces the right drift.
Formally implement let chains
## Let chains
My longest and hardest contribution since #64010.
Thanks to `@Centril` for creating the RFC and special thanks to `@matthewjasper` for helping me since the beginning of this journey. In fact, `@matthewjasper` did much of the complicated MIR stuff so it's true to say that this feature wouldn't be possible without him. Thanks again `@matthewjasper!`
With the changes proposed in this PR, it will be possible to chain let expressions along side local variable declarations or ordinary conditional expressions. In other words, do much of what the `if_chain` crate already does.
## Other considerations
* `if let guard` and `let ... else` features need special care and should be handled in a following PR.
* Irrefutable patterns are allowed within a let chain context
* ~~Three Clippy lints were already converted to start dogfooding and help detect possible corner cases~~
cc #53667
Delete pretty printer tracing
These are left over from 2011. I did not find these helpful at all in my work on https://github.com/dtolnay/prettyplease despite doing significant refactors to this code. Learning what these messages all refer to is harder than putting in your own messages to log exactly what is relevant to specifically the thing that you are working on debugging.
Directly use ConstValue for single literals in blocks
Addresses the minimal repro in https://github.com/rust-lang/rust/issues/92186, but doesn't fix the underlying problem (which would be solved by solving the anon subst problem afaict).
I do, however, think that it makes sense in general to treat single literals in anon blocks as const values directly, especially in light of the problem that the issue refers to (anon const evaluation being postponed until infer variables in substs can be resolved, which was introduced by https://github.com/rust-lang/rust/pull/90023), i.e. while we do get warnings for those unnecessary braces, we should try to avoid errors caused by those braces if possible.
Improve SIMD casts
* Allows `simd_cast` intrinsic to take `usize` and `isize`
* Adds `simd_as` intrinsic, which is the same as `simd_cast` except for saturating float-to-int conversions (matching the behavior of `as`).
cc `@workingjubilee`
Let qpath contain NtTy: `<$:ty as $:ty>::…`
Example:
```rust
macro_rules! m {
(<$type:ty as $trait:ty>::$name:ident) => {
<$type as $trait>::$name
};
}
fn main() {
let _: m!(<str as ToOwned>::Owned);
}
```
Previous behavior:
```console
error: expected identifier, found `ToOwned`
--> src/main.rs:3:19
|
3 | <$type as $trait>::$name
| ^^^^^^ expected identifier
...
8 | let _: m!(<str as ToOwned>::Owned);
| ---------------------------
| |
| this macro call doesn't expand to a type
| in this macro invocation
```
The <code>expected identifier, found \`ToOwned\`</code> error is particularly silly. I think it should be fine to accept this code as long as $trait is of the form `TyKind::Path(None, path)`; if it is any other kind of `NtTy`, we'll keep the same behavior as before.
Implement raw-dylib support for windows-gnu
Add support for `#[link(kind = "raw-dylib")]` on windows-gnu targets. Work around binutils's linker's inability to read import libraries produced by LLVM by calling out to the binutils `dlltool` utility to create an import library from a temporary .DEF file; this approach is effectively a slightly refined version of `@mati865's` earlier attempt at this strategy in PR #88801. (In particular, this attempt at this strategy adds support for `#[link_ordinal(...)]` as well.)
In support of #58713.
Avoid unnecessary monomorphization of inline asm related functions
This should reduce build time for codegen backends by avoiding duplicated monomorphization of certain inline asm related functions for each passed in closure type.
Abstract the pretty printer's ringbuffer to be infinitely sized
This PR backports 8e5e83c3ff from the `prettyplease` crate into `rustc_ast_pretty`.
Using a dedicated RingBuffer type with non-wrapping indices, instead of manually `%`-ing indices into a capped sized buffer, unlocks a number of simplifications to the pretty printing algorithm implementation in followup commits such as fcb5968b1e and 4427cedcb8.
This change also greatly reduces memory overhead of the pretty printer. The old implementation always grows its buffer to 205920 bytes even for files without deeply nested code, because it only wraps its indices when they hit the maximum tolerable size of the ring buffer (the size after which the pretty printer will crash if there are that many tokens buffered). In contrast, the new implementation uses memory proportional to the peak number of simultaneously buffered tokens only, not the number of tokens that have ever been in the buffer.
Speaking of crashing the pretty printer and "maximum tolerable size", the constant used for that in the old implementation is a lie:
de9b573eed/compiler/rustc_ast_pretty/src/pp.rs (L227-L228)
It was raised from 3 to 55 in https://github.com/rust-lang/rust/pull/33934 because that was empirically the size that avoided crashing on one particular test crate, but according to https://github.com/rust-lang/rust/pull/33934#issuecomment-226700470 other syntax trees still crash at that size. There is no reason to believe that any particular size is good enough for arbitrary code, and using a large number like 55 adds overhead to inputs that never need close to that much of a buffer. The new implementation eliminates this tradeoff.
Add some more attribute validation
This adds some more validation for the position of attributes:
* `link` is only valid on an `extern` block
* `windows_subsystem` and `no_builtins` are only valid at the crate level
Fix ICEs related to `Deref<Target=[T; N]>` on newtypes
1. Stash a const infer's type into the canonical var during canonicalization, so we can recreate the fresh const infer with that same type.
For example, given `[T; _]` we know `_` is a `usize`. If we go from infer => canonical => infer, we shouldn't forget that variable is a usize.
Fixes#92626Fixes#83704
2. Don't stash the autoderef'd slice type that we get from method lookup, but instead recreate it during method confirmation. We need to do this because the type we receive back after picking the method references a type variable that does not exist after probing is done.
Fixes#92637
... A better solution for the second issue would be to actually _properly_ implement `Deref` for `[T; N]` instead of fixing this autoderef hack to stop leaking inference variables. But I actually looked into this, and there are many complications with const impls.
Replace use of `ty()` on term and use it in more places. This will allow more flexibility in the
future, but slightly worried it allows items which are consts which only accept types.
Remove LLVMRustMarkAllFunctionsNounwind
This was originally introduced in #10916 as a way to remove all landing
pads when performing LTO. However this is no longer necessary today
since rustc properly marks all functions and call-sites as nounwind
where appropriate.
In fact this is incorrect in the presence of `extern "C-unwind"` which
must create a landing pad when compiled with `-C panic=abort` so that
foreign exceptions are caught and properly turned into aborts.
rustc_codegen_llvm: Remove (almost) unused span parameter from many functions in metadata.rs
Many functions and intermediate data structures in `rustc_codegen_llvm/src/debuginfo/metadata.rs` take a span parameter that is only used for providing a span to a `span_bug!()` invocation, in case the debuginfo typemap gets corrupted. However, this span does not really convey useful information as it just points to the first point a type is used -- and half of the time is initialized to `DUMMY_SP`.
This PR removes this span parameter from the module.
It also removes the following unused parameters from `composite_type_metadata()` together with an outdated comment:
```rust
// Ignore source location information as long as it
// can't be reconstructed for non-local crates.
_file_metadata: &'ll DIFile,
_definition_span: Span,
```
Implement `#[rustc_must_implement_one_of]` attribute
This PR adds a new attribute — `#[rustc_must_implement_one_of]` that allows changing the "minimal complete definition" of a trait. It's similar to GHC's minimal `{-# MINIMAL #-}` pragma, though `#[rustc_must_implement_one_of]` is weaker atm.
Such attribute was long wanted. It can be, for example, used in `Read` trait to make transitions to recently added `read_buf` easier:
```rust
#[rustc_must_implement_one_of(read, read_buf)]
pub trait Read {
fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
let mut buf = ReadBuf::new(buf);
self.read_buf(&mut buf)?;
Ok(buf.filled_len())
}
fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<()> {
default_read_buf(|b| self.read(b), buf)
}
}
impl Read for Ty0 {}
//^ This will fail to compile even though all `Read` methods have default implementations
// Both of these will compile just fine
impl Read for Ty1 {
fn read(&mut self, buf: &mut [u8]) -> Result<usize> { /* ... */ }
}
impl Read for Ty2 {
fn read_buf(&mut self, buf: &mut ReadBuf<'_>) -> Result<()> { /* ... */ }
}
```
For now, this is implemented as an internal attribute to start experimenting on the design of this feature. In the future we may want to extend it:
- Allow arbitrary requirements like `a | (b & c)`
- Allow multiple requirements like
- ```rust
#[rustc_must_implement_one_of(a, b)]
#[rustc_must_implement_one_of(c, d)]
```
- Make it appear in rustdoc documentation
- Change the syntax?
- Etc
Eventually, we should make an RFC and make this (or rather similar) attribute public.
---
I'm fairly new to compiler development and not at all sure if the implementation makes sense, but at least it passes tests :)
ProjectionPredicate should be able to handle both associated types and consts so this adds the
first step of that. It mainly just pipes types all the way down, not entirely sure how to handle
consts, but hopefully that'll come with time.
Replace `NestedVisitorMap` with generic `NestedFilter`
This is an attempt to make the `intravisit::Visitor` API simpler and "more const" with regard to nested visiting.
With this change, `intravisit::Visitor` does not visit nested things by default, unless you specify `type NestedFilter = nested_filter::OnlyBodies` (or `All`). `nested_visit_map` returns `Self::Map` instead of `NestedVisitorMap<Self::Map>`. It panics by default (unreachable if `type NestedFilter` is omitted).
One somewhat trixty thing here is that `nested_filter::{OnlyBodies, All}` live in `rustc_middle` so that they may have `type Map = map::Map` and so that `impl Visitor`s never need to specify `type Map` - it has a default of `Self::NestedFilter::Map`.
Remove deprecated LLVM-style inline assembly
The `llvm_asm!` was deprecated back in #87590 1.56.0, with intention to remove
it once `asm!` was stabilized, which already happened in #91728 1.59.0. Now it
is time to remove `llvm_asm!` to avoid continued maintenance cost.
Closes#70173.
Closes#92794.
Closes#87612.
Closes#82065.
cc `@rust-lang/wg-inline-asm`
r? `@Amanieu`
Rename Printer constructor from mk_printer() to Printer::new()
The original naming is left over from 2011 which was before impl blocks and associated functions existed.
21313d623a/src/comp/pretty/pp.rs
Fix suggesting turbofish with lifetime arguments
Now we suggest turbofish correctly given exprs like `foo<'_>`.
Also fix suggestion when we have `let x = foo<bar, baz>;` which was broken.
Fix `try wrapping expression in variant` suggestion with struct field shorthand
Fixes a broken suggestion: [playground](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=83fe2dbfe1485f8cfca1aef2a6582e77)
before:
```
error[E0308]: mismatched types
--> src/main.rs:7:19
|
7 | let x = Foo { bar };
| ^^^ expected enum `Option`, found integer
|
= note: expected enum `Option<i32>`
found type `{integer}`
help: try wrapping the expression in `Some`
|
7 | let x = Foo { Some(bar) };
| +++++ +
```
after:
```
error[E0308]: mismatched types
--> src/main.rs:7:19
|
7 | let x = Foo { bar };
| ^^^ expected enum `Option`, found integer
|
= note: expected enum `Option<i32>`
found type `{integer}`
help: try wrapping the expression in `Some`
|
7 | let x = Foo { bar: Some(bar) };
| ~~~~~~~~~~~~~~
```
r? ``@m-ou-se``
since you touched the code last in #91080
expand: Pick `cfg`s and `cfg_attrs` one by one, like other attributes
This is a rebase of https://github.com/rust-lang/rust/pull/83354, but without any language-changing parts ~(except for https://github.com/rust-lang/rust/pull/84110)~, i.e. the attribute expansion order is the same.
This is a pre-requisite for any other changes making cfg attributes closer to regular macro attributes
- Possibly changing their expansion order (https://github.com/rust-lang/rust/issues/83331)
- Keeping macro backtraces for cfg attributes, or otherwise making them visible after expansion without keeping them in place literally (https://github.com/rust-lang/rust/pull/84110).
Two exceptions to the "one by one" behavior are:
- cfgs eagerly expanded by `derive` and `cfg_eval`, they are still expanded in a batch, that's by design.
- cfgs at the crate root, they are currently expanded not during the main expansion pass, but before that, during `#![feature]` collection. I'll try to disentangle that logic later in a separate PR.
r? `@Aaron1011`
