Use mir constant in thir instead of ty::Const
This is blocked on https://github.com/rust-lang/rust/pull/94059 (does include its changes, the first two commits in this PR correspond to those changes) and https://github.com/rust-lang/rust/pull/93800 being reinstated (which had to be reverted). Mainly opening since `@lcnr` offered to give some feedback and maybe also for a perf-run (if necessary).
This currently contains a lot of duplication since some of the logic of `ty::Const` had to be copied to `mir::ConstantKind`, but with the introduction of valtrees a lot of that functionality will disappear from `ty::Const`.
Only the last commit contains changes that need to be reviewed here. Did leave some `FIXME` comments regarding future implementation decisions and some things that might be incorrectly implemented.
r? `@oli-obk`
Currently it just calls `truncate(0)`. `truncate()` is (a) not marked as
`#[inline]`, and (b) more general than needed for `clear()`.
This commit changes `clear()` to do the work itself. This modest change
was first proposed in rust-lang#74172, where the reviewer rejected it because
there was insufficient evidence that `Vec::clear()`'s performance
mattered enough to justify the change. Recent changes within rustc have
made `Vec::clear()` hot within `macro_parser.rs`, so the change is now
clearly worthwhile.
Although it doesn't show wins on CI perf runs, this seems to be because they
use PGO. But not all platforms currently use PGO. Also, local builds don't use
PGO, and `truncate` sometimes shows up in an over-represented fashion in local
profiles. So local profiling will be made easier by this change.
Note that this will also benefit `String::clear()`, because it just
calls `Vec::clear()`.
Finally, the commit removes the `vec-clear.rs` codegen test. It was
added in #52908. From before then until now, `Vec::clear()` just called
`Vec::truncate()` with a zero length. The body of Vec::truncate() has
changed a lot since then. Now that `Vec::clear()` is doing actual work
itself, and not just calling `Vec::truncate()`, it's not surprising that
its generated code includes a load and an icmp. I think it's reasonable
to remove this test.
Rollup of 4 pull requests
Successful merges:
- #95441 (Always use system `python3` on MacOS)
- #95954 (Fix broken link in coverage tools docs)
- #95984 (Fix spelling in docs for `can_not_overflow`)
- #95989 (diagnostics: regression test for spurrious "help: store this in the heap")
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Previously, bootstrap unconditionally rebuilt the stage 2 compiler,
even if it had previously built stage 1. This changes it to reuse stage 1 if possible.
Fix broken link in coverage tools docs
During stabilization the link to example screenshot wad not updated, making rendered docs somewhat less useful. Move that screenshot from unstable book into rustc docs and make documentation point to that new place. Also remove `/img` in unstable book since there are no more any files there.
Always use system `python3` on MacOS
This PR includes 2 changes:
1. Always use the system Python found at `/usr/bin/python3` on MacOS
2. Removes the hard requirement on having `python` in your system path if you didn't specify alternatives. The proposed change will instead attempt to find and use in order: `python` -> `python3` -> `python2`. This change isn't strictly necessary but without any change to this check, the original issue inspiring this change will still exist.
Fixes#95204
r? ```@jyn514```
Loading the fallback bundle in compilation sessions that won't go on to
emit any errors unnecessarily degrades compile time performance, so
lazily create the Fluent bundle when it is first required.
Signed-off-by: David Wood <david.wood@huawei.com>
Rollup of 7 pull requests
Successful merges:
- #95316 (Rustdoc: Discriminate required and provided associated constants and types)
- #95405 (Move name resolution logic to a dedicated file)
- #95914 (Implement tuples using recursion)
- #95918 (Delay a bug when we see SelfCtor in ref pattern)
- #95970 (Fix suggestions in case of `T:` bounds)
- #95973 (prevent opaque types from appearing in impl headers)
- #95986 (Autolabel library PRs with T-libs)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
I managed to break this in https://github.com/rust-lang/rust/pull/95449.
I am not quite sure why this is the correct fix, but it doesn't break `doc --stage 0`
and is strictly closer to the previous behavior.
Previously, rustdoc would error with strange issues because of the mismatched sysroot:
```
error[E0460]: found possibly newer version of crate `std` which `rustc_span` depends on
--> /home/jnelson/rust-lang/rust/compiler/rustc_lint_defs/src/lib.rs:14:5
|
14 | use rustc_span::{sym, symbol::Ident, Span, Symbol};
| ^^^^^^^^^^
|
= note: perhaps that crate needs to be recompiled?
= note: the following crate versions were found:
crate `std`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-ff9290e971253a38.rlib
crate `std`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-ff9290e971253a38.so
crate `rustc_span`: /home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/deps/librustc_span-ed11dce30c1766f9.rlib
```
Autolabel library PRs with T-libs
Continuation of https://github.com/rust-lang/highfive/pull/389
We're trying to improve the libs team review structure and part of that is defaulting PRs to the T-libs team to act as a mini-triage team for all the libs teams / project groups. Highfive doesn't do issue tagging so we will rely on triagebot to pre-triage for t-libs to post-triage :)
prevent opaque types from appearing in impl headers
cc `@lqd`
opaque types are not distinguishable from their hidden type at the codegen stage. So we could either end up with cases where the hidden type doesn't implement the trait (which will thus ICE) or where the hidden type does implement the trait (so we'd be using its impl instead of the one written for the opaque type). This can even lead to unsound behaviour without unsafe code.
Fixes https://github.com/rust-lang/rust/issues/86411.
Fixes https://github.com/rust-lang/rust/issues/84660.
rebase of #87382 plus some diagnostic tweaks
Fix suggestions in case of `T:` bounds
This PR fixes a corner case in `suggest_constraining_type_params` that was causing incorrect suggestions.
For the following functions:
```rust
fn a<T:>(t: T) { [t, t]; }
fn b<T>(t: T) where T: { [t, t]; }
```
We previously suggested the following:
```text
...
help: consider restricting type parameter `T`
|
1 | fn a<T: Copy:>(t: T) { [t, t]; }
| ++++++
...
help: consider further restricting this bound
|
2 | fn b<T>(t: T) where T: + Copy { [t, t]; }
| ++++++
```
Note that neither `T: Copy:` not `where T: + Copy` is a correct bound.
With this commit the suggestions are correct:
```text
...
help: consider restricting type parameter `T`
|
1 | fn a<T: Copy>(t: T) { [t, t]; }
| ++++
...
help: consider further restricting this bound
|
2 | fn b<T>(t: T) where T: Copy { [t, t]; }
| ++++
```
r? `@compiler-errors`
I've tried fixing #95898 here too, but got too confused with how `suggest_traits_to_import` works and what it does 😅
Implement tuples using recursion
Because it is c00l3r™, requires less repetition and can be used as a reference for external people.
This change is non-essential and I am not sure about potential performance impacts so feel free to close this PR if desired.
r? `@petrochenkov`
Move name resolution logic to a dedicated file
The code resolution logic from an Ident is scattered between several files.
The first commits creates `rustc_resolve::probe` module to hold the different mutually recursive functions together. Just a move, no code change.
The following commits attempt to make the logic a bit more readable.
The two fields `last_import_segment` and `unusable_binding` are replaced by function parameters.
In order to manage the fallout, `maybe_` variants of the function are added, dedicated to speculative resolution.
r? `@petrochenkov`
Rustdoc: Discriminate required and provided associated constants and types
Currently, rustdoc merely separates required and provided associated _functions_ (i.e. methods). This PR extends this to constants (fixes#94652) and types. This makes the documentation of all three kinds of associated items more alike and consistent.
As an aside, associated types may actually be provided / have a default when users enable the unstable feature `associated_type_defaults`.
| Before | After |
|---|---|
|  |  |
|  |  |
### `clean::types::ItemKind` modification
* `ItemKind::TypedefItem(.., true)` → `ItemKind::AssocTypeItem(..)`
* `ItemKind::TypedefItem(.., false)` → `ItemKind::TypedefItem(..)`
Further, I added `ItemKind::TyAssoc{Const,Type}Item`, the “required” variant of `ItemKind::Assoc{Const,Type}Item`, analogous to `ItemKind::TyMethodItem` with `ItemKind::MethodItem`. These new variants don't contain new information really, they are just the result of me getting rid of the `Option<_>` field in `AssocConstItem` and `AssocTypeItem`.
**Goal**: Make associated items more consistent.
Originally I thought modifying `ItemKind` was necessary to achieve the new functionality of this PR but in retrospect, it does not. If you don't like the changes to `ItemKind`, I think I _can_ get rid of them.
This change is the root cause of those tiny changes in a lot of different files.
### Concerns and Open Questions
* **breaking changes** to hyperlinks: Some heading IDs change:
* `associated-const` (sic!) -> `{provided,required}-associated-consts`
* `associated-types` -> `{provided,required}-associated-types`
* **verbosity** of the headings _{Required,Provided} Associated {Constants,Types}_
* For some files, I am not sure if the changes I made are correct. So please take extra care when reviewing `conversions.rs` (conversion to JSON), `cache.rs`/`fold_item`, `stripper.rs`/`fold_item`, `check_doc_test_visibility.rs`/`should_have_doc_example`, `collect_intra_doc_links.rs`/`from_assoc_item`
* JSON output: I still map `AssocTypeItem`s to `Typedef` etc. (FIXME)
Rollup of 4 pull requests
Successful merges:
- #95783 (rustdoc doctest: include signal number in exit status)
- #95794 (`parse_tt`: a few more tweaks)
- #95963 ([bootstrap] Grab the right FileCheck binary for dist when cross-compiling.)
- #95975 (Don't test -Cdefault-linker-libraries=yes when cross compiling.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
[bootstrap] Grab the right FileCheck binary for dist when cross-compiling.
Fixes#95862
We were using the target dir for all the other LLVM tools (`llvm-config`, `llvm-ar`, etc) but the build target dir for `FileCheck`. This meant for targets which are cross-compiled, we were copying the wrong binary.
Skip `Lazy` for some metadata tables
Some metadata tables encode their entries indirectly, through the Lazy construct. This is useful when dealing with variable length encoding, but incurs the extra cost of one u32.
Meanwhile, some fields can be encoded in a single u8, or can use a short fixed-length encoding. This PR proposes to do so, and avoid the overhead.
