deduplicate infer var instantiation
Having 3 separate implementations of one of the most subtle parts of our type system is not a good strategy if we want to maintain a sound type system ✨ while working on this I already found some subtle bugs in the existing code, so that's awesome 🎉 cc #121159
This was necessary as I am not confident in my nll changes in #119106, so I am first cleaning this up in a separate PR.
r? `@BoxyUwU`
This change was prompted by the stage1 compiler spending 4% of its time
when compiling the polymorphic-recursion MIR opt test in `unlikely`.
Intrinsic fallback bodies like `unlikely` should always be inlined, it's
very silly if they are not. To do this, we enable the fallback bodies to
be cross-crate inlineable. Not that this matters for our workloads since
the compiler never actually _uses_ the "fallback bodies", it just uses
whatever was cfg(bootstrap)ped, so I've also added `#[inline]` to those.
Noticed these while doing something else. There's no practical change, but it's preferable to use `DUMMY_SP` as little as possible, particularly when we have perfectlly useful `Span`s available.
some trait system cleanups
Always eagerly replace projections with infer vars if normalization is ambig. Unsure why we previously didn't do so, wasn't able to find an explanation in #90887. This adds some complexity to the trait system and is afaict unnecessary.
The second commit simplifies `pred_known_to_hold_modulo_regions`, afaict the optional `fulfill` isn't necessary anymore.
r? types cc `@jackh726`
Extend Level API
I need this API for https://github.com/rust-lang/rust-clippy/pull/12303: I have a nested `cfg` attribute (so a `MetaItem`) and I'd like to still be able to match against all possible kind of `Level`s.
There are lots of functions that modify a diagnostic. This can be via a
`&mut Diagnostic` or a `&mut DiagnosticBuilder`, because the latter type
wraps the former and impls `DerefMut`.
This commit converts all the `&mut Diagnostic` occurrences to `&mut
DiagnosticBuilder`. This is a step towards greatly simplifying
`Diagnostic`. Some of the relevant function are made generic, because
they deal with both errors and warnings. No function bodies are changed,
because all the modifier methods are available on both `Diagnostic` and
`DiagnosticBuilder`.
macro_rules: Preserve all metavariable spans in a global side table
This PR preserves spans of `tt` metavariables used to pass tokens to declarative macros.
Such metavariable spans can then be used in span combination operations like `Span::to` to improve all kinds of diagnostics.
Spans of non-`tt` metavariables are currently kept in nonterminal tokens, but the long term plan is remove all nonterminal tokens from rustc parser and rely on the proc macro model with invisible delimiters (#114647, #67062).
In particular, `NtIdent` nonterminal (corresponding to `ident` metavariables) becomes easy to remove when this PR lands (#119412 does it).
The metavariable spans are kept in a global side table keyed by `Span`s of original tokens.
The alternative to the side table is keeping them in `SpanData` instead, but the performance regressions would be large because any spans from tokens passed to declarative macros would stop being inline and would work through span interner instead, and the penalty would be paid even if we never use the metavar span for the given original span.
(But also see the comment on `fn maybe_use_metavar_location` describing the map collision issues with the side table approach.)
There are also other alternatives - keeping the metavar span in `Token` or `TokenTree`, but associating it with `Span` itsel is the most natural choice because metavar spans are used in span combining operations, and those operations are not necessarily tied to tokens.
Remove const_prop.rs
Removed const_prop.rs and moved its contents to const_prop_lint.rs and dataflow_const_prop.rs where they are used.
const_prop.rs does not actually do any const propagation any more. After #116012 all it contains is code that is used by const_prop_lint.rs and one macro that is used by dataflow_const_prop.rs. So it made sense to just move it to those two places and remove this file.
Add help to `hir_analysis_unrecognized_intrinsic_function`
To help remind forgetful people like me what step they forgot.
(If this just ICE'd, https://github.com/rust-lang/compiler-team/issues/620 style, the stack trace would point me here, but since there's a "nice" error that information is lost.)
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.
