Tracking import use types for more accurate redundant import checking
fixes#117448
By tracking import use types to check whether it is scope uses or the other situations like module-relative uses, we can do more accurate redundant import checking.
For example unnecessary imports in std::prelude that can be eliminated:
```rust
use std::option::Option::Some;//~ WARNING the item `Some` is imported redundantly
use std::option::Option::None; //~ WARNING the item `None` is imported redundantly
```
fixes#117448
For example unnecessary imports in std::prelude that can be eliminated:
```rust
use std::option::Option::Some;//~ WARNING the item `Some` is imported redundantly
use std::option::Option::None; //~ WARNING the item `None` is imported redundantly
```
Rollup of 7 pull requests
Successful merges:
- #120526 (rustdoc: Correctly handle long crate names on mobile)
- #121100 (Detect when method call on argument could be removed to fulfill failed trait bound)
- #121160 (rustdoc: fix and refactor HTML rendering a bit)
- #121198 (Add more checks for `unnamed_fields` during HIR analysis)
- #121218 (Fix missing trait impls for type in rustc docs)
- #121221 (AstConv: Refactor lowering of associated item bindings a bit)
- #121237 (Use better heuristic for printing Cargo specific diagnostics)
r? `@ghost`
`@rustbot` modify labels: rollup
AstConv: Refactor lowering of associated item bindings a bit
Split off from #119385 as discussed, namely the first two commits (modulo one `FIXME` getting turned into a `NOTE`).
The second commit removes `astconv::ConvertedBinding{,Kind}` in favor of `hir::TypeBinding{,Kind}`. The former was a — in my opinion — super useless intermediary. As you can tell from the diff, its removal shaves off some code. Furthermore, yeeting it will make it easier to implement the type resolution fixes in #119385.
Nothing in this PR should have any semantic effect.
r? `@compiler-errors`
<sub>**Addendum** as in #118668: What I call “associated item bindings” are commonly referred to as “type bindings” for historical reasons. Nowadays, “type bindings” include assoc type bindings, assoc const bindings and RTN (return type notation) which is why I prefer not to use this outdated term.</sub>
Add more checks for `unnamed_fields` during HIR analysis
Fixes#121151
I also found that we don't prevent enums here so
```rs
#[repr(C)]
#[derive(Debug)]
enum A {
#[default]
B,
C,
}
#[repr(C)]
#[derive(Debug)]
struct D {
_: A,
}
```
leads to an ICE on an `self.is_struct() || self.is_union()` assertion, so fixed that too.
rustdoc: fix and refactor HTML rendering a bit
* refactoring: get rid of a bunch of manual `f.alternate()` branches
* not sure why this wasn't done so already, is this perf-sensitive?
* fix an ICE in debug builds of rustdoc
* rustdoc used to crash on empty outlives-bounds: `where 'a:`
* properly escape const generic defaults
* actually print empty trait and outlives-bounds (doesn't work for cross-crate reexports yet, will fix that at some other point) since they can have semantic significance
* outlives-bounds: forces lifetime params to be early-bound instead of late-bound which is technically speaking part of the public API
* trait-bounds: can affect the well-formedness, consider
* makeshift “const-evaluatable” bounds under `generic_const_exprs`
* bounds to force wf-checking in light of #100041 (quite artificial I know, I couldn't figure out something better), see https://github.com/rust-lang/rust/pull/121160#discussion_r1491563816
Properly deal with weak alias types as self types of impls
Fixes#114216.
Fixes#116100.
Not super happy about the two ad hoc “normalization” implementations for weak alias types:
1. In `inherent_impls`: The “peeling”, normalization to [“WHNF”][whnf]: Semantically that's exactly what we want (neither proper normalization nor shallow normalization would be correct here). Basically a weak alias type is “nominal” (well...^^) if the WHNF is nominal. [#97974](https://github.com/rust-lang/rust/pull/97974) followed the same approach.
2. In `constrained_generic_params`: Generic parameters are constrained by a weak alias type if the corresp. “normalized” type constrains them (where we only normalize *weak* alias types not arbitrary ones). Weak alias types are injective if the corresp. “normalized” type is injective.
Both have ad hoc overflow detection mechanisms.
**Coherence** is handled in #117164.
r? `@oli-obk` or types
[whnf]: https://en.wikipedia.org/wiki/Lambda_calculus_definition#Weak_head_normal_form
create stamp file for clippy
Due to missing stamp file, we were downloading (and applying nix patches if enabled) continuously every time `Config::download_clippy` was called. This change fixes that by creating stamp file at the end of the function.
Fixes#119442
Fix `cfg(target_abi = "sim")` on `i386-apple-ios`
Since https://github.com/rust-lang/rust/issues/80970 is stabilizing, I went and had a look, and found that the result was wrong on `i386-apple-ios`.
r? rust-lang/macos
Use fulfillment in next trait solver coherence
Use fulfillment in the new trait solver's `impl_intersection_has_impossible_obligation` routine. This means that inference that falls out of processing other obligations can influence whether we can determine if an obligation is impossible to satisfy. See the committed test.
This should be completely sound, since evaluation and fulfillment both respect intercrate mode equally.
We run the risk of breaking coherence later if we were to change the rules of fulfillment and/or inference during coherence, but this is a problem which affects evaluation, as nested obligations from a trait goal are processed together and can influence each other in the same way.
r? lcnr
cc #114862
Also changed obligationctxt -> fulfillmentctxt because it feels kind of redundant to use an ocx here. I don't really care enough and can change it back if it really matters much.
Fix typo in VecDeque::handle_capacity_increase() doc comment.
Strategies B and C both show a full buffer before the capacity increase, while strategy A had one empty element left. Filled the last element in.
errors: only eagerly translate subdiagnostics
Subdiagnostics don't need to be lazily translated, they can always be eagerly translated. Eager translation is slightly more complex as we need to have a `DiagCtxt` available to perform the translation, which involves slightly more threading of that context.
This slight increase in complexity should enable later simplifications - like passing `DiagCtxt` into `AddToDiagnostic` and moving Fluent messages into the diagnostic structs rather than having them in separate files (working on that was what led to this change).
r? ```@nnethercote```
Don't use mem::zeroed in vec::IntoIter
`mem::zeroed` is not a trivial function. Maybe it was once, but now it involves multiple locals, copies, and an intrinsic that gets monomorphized into a call to `panic_nounwind` for iterators of types like `Vec<&T>`. Of course all that complexity is trivially optimized out, but generating a bunch of IR where we don't need to just so we can optimize it away later is silly.
tidy: reduce allocs
this reduces allocs in tidy from (dhat output)
```
==31349== Total: 1,365,199,543 bytes in 4,774,213 blocks
==31349== At t-gmax: 10,975,708 bytes in 66,093 blocks
==31349== At t-end: 2,880,947 bytes in 12,332 blocks
==31349== Reads: 5,210,008,956 bytes
==31349== Writes: 1,280,920,127 bytes
```
to
```
==66633== Total: 791,565,538 bytes in 3,503,144 blocks
==66633== At t-gmax: 10,914,511 bytes in 65,997 blocks
==66633== At t-end: 395,531 bytes in 941 blocks
==66633== Reads: 4,249,388,949 bytes
==66633== Writes: 814,119,580 bytes
```
<del>by wrapping regex and updating `ignore` (effect probably not only from `ignore`, didn't measured)</del>
also moves one more regex into `Lazy` to reduce regex rebuilds.
Rollup of 8 pull requests
Successful merges:
- #119032 (Use a hardcoded constant instead of calling OpenProcessToken.)
- #120932 (const_mut_refs: allow mutable pointers to statics)
- #121059 (Add and use a simple extension trait derive macro in the compiler)
- #121135 (coverage: Discard spans that fill the entire function body)
- #121187 (Add examples to document the return type of quickselect functions)
- #121191 (Add myself to review rotation (and a rustbot ping))
- #121192 (Give some intrinsics fallback bodies)
- #121197 (Ensure `./configure` works when `configure.py` path contains spaces)
r? `@ghost`
`@rustbot` modify labels: rollup
Due to missing stamp file, we were downloading (and applying nix patches if enabled)
continuously every time `Config::download_clippy` was called. This change fixes that by
creating stamp file at the end of the function.
Signed-off-by: onur-ozkan <work@onurozkan.dev>
Ensure `./configure` works when `configure.py` path contains spaces
Add quotes around paths that may contains spaces in `configure` to avoid the shell splitting the path into multiple arguments.
Add myself to review rotation (and a rustbot ping)
I've still got a ~month of unemployment ( 🤞 ), so I'll put some of that time into reviewing.
Unrelatedly, I've now poked enough at match lowering that I want to follow what happens to it, so I added a rustbot ping.
Add examples to document the return type of quickselect functions
Currently, `select_nth_unstable`, `select_nth_unstable_by`, and `select_nth_unstable_by_key`'s examples do not show how to use the return values of the functions in an example, so this PR adds that in.
Note: I didn't know what to call the parameters, so I settled on lesser, median, greater because the example is used for median finding so I retained that naming for the pivot, but lesser and greater are poor names for the example that sorts in descending order, because lesser and greater are then flipped.
I think it's common to say "lo" and "hi" for low and high respectively, but that's also not great when the comparator flips the elements. Otherwise, "left" and "right" are also commonly used but I think that's poor naming because some languages read right to left so those names are also unintuitive.
Lesser and greater are also not that great but I found a test that used `less`, `equal`, `greater` so I took that: dfa88b328f/library/core/tests/slice.rs (L1962)
coverage: Discard spans that fill the entire function body
While debugging some other coverage changes, I discovered a frustrating inconsistency that occurs in functions containing closures, if they end with an implicit `()` return instead of an explicit trailing-expression.
This turns out to have been caused by the corresponding node in MIR having a span that covers the entire function body. When preparing coverage spans, any span that fills the whole body tends to cause more harm than good, so this PR detects and discards those spans.
(This isn't the first time whole-body spans have caused problems; we also eliminated some of them in #118525.)
Add and use a simple extension trait derive macro in the compiler
Adds `#[extension]` to `rustc_macros` for implementing an extension trait. This expands an impl (with an optional visibility) into two parallel trait + impl definitions.
before:
```rust
pub trait Extension {
fn a();
}
impl Extension for () {
fn a() {}
}
```
to:
```rust
#[extension]
pub impl Extension for () {
fn a() {}
}
```
Opted to just implement it by hand because I couldn't figure if there was a "canonical" choice of extension trait macro in the ecosystem. It's really lightweight anyways, and can always be changed.
I'm interested in adding this because I'd like to later split up the large `TypeErrCtxtExt` traits into several different files. This should make it one step easier.
const_mut_refs: allow mutable pointers to statics
Fixes https://github.com/rust-lang/rust/issues/118447
Writing this PR became a bit messy, see [Zulip](https://rust-lang.zulipchat.com/#narrow/stream/146212-t-compiler.2Fconst-eval/topic/Statics.20pointing.20to.20interior.20mutable.20statics) for some of my journey.^^ Turns out there was a long-standing bug in our qualif logic that led to us incorrectly classifying certain places as "no interior mut" when they actually had interior mut. Due to that the `const_refs_to_cell` feature gate was required far less often than it otherwise would, e.g. in [this code](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=9e0c042c451b3d11d64dd6263679a164). Fixing this however would be a massive breaking change all over libcore and likely the wider ecosystem. So I also changed the const-checking logic to just not require the feature gate for the affected cases. While doing so I discovered a bunch of logic that is not explained and that I could not explain. However I think stabilizing some const-eval feature will make most of that logic inconsequential so I just added some FIXMEs and left it at that.
r? `@oli-obk`
Use a hardcoded constant instead of calling OpenProcessToken.
Now that Win 7 support is dropped, we can resurrect #90144.
GetCurrentProcessToken is defined in processthreadsapi.h as:
FORCEINLINE
HANDLE
GetCurrentProcessToken (
VOID
)
{
return (HANDLE)(LONG_PTR) -4;
}
Since it's very unlikely that this constant will ever change, let's just use it instead of making calls to get the same information.
yes, once_cell better, but ...
this reduces from
==31349== Total: 1,365,199,543 bytes in 4,774,213 blocks
==31349== At t-gmax: 10,975,708 bytes in 66,093 blocks
==31349== At t-end: 2,880,947 bytes in 12,332 blocks
==31349== Reads: 5,210,008,956 bytes
==31349== Writes: 1,280,920,127 bytes
to
==47796== Total: 821,467,407 bytes in 3,955,595 blocks
==47796== At t-gmax: 10,976,209 bytes in 66,100 blocks
==47796== At t-end: 2,944,016 bytes in 12,490 blocks
==47796== Reads: 4,788,959,023 bytes
==47796== Writes: 975,493,639 bytes
miropt-test-tools: remove regex usage
this removes regex usage and slightly refactors ext stripping in one case
Make `ConstPropLint` lint run on promoteds
Fixes#117949 wherein the lint didn't fire for the following promoteds:
- SHL or SHR operators in a non-optimized build
- any arithmetic operator in an optimized build
What I have done here is simply enabled `ConstPropLint` to run on promoted bodies by removing the relevant `if` check.
After this change _all_ promoted arithmetic operators will lint _in both non-optimized and optimized builds_. On the flip side programs containing the above mentioned overflowing promoteds that were accepted earlier will now be rejected. Hope that is okay from a backward compatibility standpoint.
I have added tests covering all overflowing promoted & non-promoted ops for both compile-time and runtime operations and for optimized as well as non-optimized builds.
I had to amend some existing tests to make them pass and had to delete a couple that were set to pass despite overflows.
This PR increases the number of duplicate diagnostics emitted (because the same operator might get linted in both the promoted MIR and the main MIR). I hope that is an acceptable trade-off given that we now lint overflows much more comprehensively than earlier.
