rustdoc: use current stage if download-rustc enabled
When using download-rustc, using stage 1 rustdoc results in the wrong librustc_driver being used.
```sh
$ ./build/host/stage1/bin/rustdoc --version
./build/host/stage1/bin/rustdoc: error while loading shared libraries: librustc_driver-7ff02ed05016d515.so: cannot open shared object file: No such file or directory
```
This change fixes that by not cutting the stage if download-rustc is enabled.
Fixes for 32-bit SPARC on Linux
This PR fixes a number of issues which previously prevented `rustc` from being built
successfully for 32-bit SPARC using the `sparc-unknown-linux-gnu` triplet.
In particular, it adds linking against `libatomic` where necessary, uses portable `AtomicU64`
for `rustc_data_structures` and rewrites the spec for `sparc_unknown_linux_gnu` to use
`TargetOptions` and replaces the previously used `-mv8plus` with the more portable
`-mcpu=v9 -m32`.
To make `rustc` build successfully, support for 32-bit SPARC needs to be added to the `object`
crate as well as the `nix` crate which I will be sending out later as well.
r? nagisa
patch `rust-lld` and `ld.lld` on NixOS
When `rustc` uses its self-contained lld, we also need to patch `rust-lld` and `ld.lld`.
The `rpath` for `rust-lld` is `$ORIGIN/../../../:$ORIGIN/../lib`, so I use `--add-rpath` instead of `--set-rpath`, which should be easier to maintain.
I also changed `src/bootstrap/src/core/download.rs`, even this doesn't fix any known issues.
For the `lld-wrapper.sh` of lld, refer to: https://github.com/rust-lang/rustc-dev-guide/pull/1999.
Remove more `PtrToPtr` casts in GVN
This addresses two things I noticed in MIR:
1. `NonNull::<T>::eq` does `(a as *mut T) == (b as *mut T)`, but it could just compare the `*const T`s, so this removes `PtrToPtr` casts that are on both sides of a pointer comparison, so long as they're not fat-to-thin casts.
2. `NonNull::<T>::addr` does `transmute::<_, usize>(p as *const ())`, but so long as `T: Thin` that cast doesn't do anything, and thus we can directly transmute the `*const T` instead.
r? mir-opt
It changes behaviour and can cause collisions. E.g. for the following snippet
```rs
mod foo {
pub mod bar {}
pub const bar: i32 = 8;
}
// tranforming the below to `use foo::bar;` causes the error:
//
// the name `bar` is defined multiple times
use foo::bar::{self};
const bar: u32 = 99;
fn main() {
let local_bar = bar;
}
```
we still normalize
```rs
use foo::bar;
use foo::bar::{self};
```
to `use foo::bar;` because this cannot cause collisions.
See: https://github.com/rust-lang/rust-analyzer/pull/17140#issuecomment-2079189725
minor: Bump `actions/download-artifact` and `upload-artifact`
These will stop working in a couple of days. I think we could still use them in a more efficient way, but more tweaking is needed for that.
Various refactorings to rustc_interface
This should make it easier to move the driver interface away from queries in the future. Many custom drivers call queries like `queries.global_ctxt()` before they are supposed to be called, breaking some things like certain `--print` and `-Zunpretty` options, `-Zparse-only` and emitting the dep info at the wrong point in time. They are also not actually necessary at all. Passing around the query output manually would avoid recomputation too and would be just as easy. Removing driver queries would also reduce the amount of global mutable state of the compiler. I'm not removing driver queries in this PR to avoid breaking the aforementioned custom drivers.
transmute size check: properly account for alignment
Fixes another place where ZST alignment was ignored when checking whether something is a newtype. I wonder how many more of these there are...
Fixes https://github.com/rust-lang/rust/issues/101084
Allow constraining opaque types during various unsizing casts
allows unsizing of tuples, arrays and Adts to constraint opaque types in their generic parameters to concrete types on either side of the unsizing cast.
Also allows constraining opaque types during trait object casts that only differ in auto traits or lifetimes.
cc #116652
Save 2 pointers in `TerminatorKind` (96 → 80 bytes)
These things don't need to be `Vec`s; boxed slices are enough.
The frequent one here is call arguments, but MIR building knows the number of arguments from the THIR, so the collect is always getting the allocation right in the first place, and thus this shouldn't ever add the shrink-in-place overhead.
std: refactor the TLS implementation
As discovered by Mara in #110897, our TLS implementation is a total mess. In the past months, I have simplified the actual macros and their expansions, but the majority of the complexity comes from the platform-specific support code needed to create keys and register destructors. In keeping with #117276, I have therefore moved all of the `thread_local_key`/`thread_local_dtor` modules to the `thread_local` module in `sys` and merged them into a new structure, so that future porters of `std` can simply mix-and-match the existing code instead of having to copy the same (bad) implementation everywhere. The new structure should become obvious when looking at `sys/thread_local/mod.rs`.
Unfortunately, the documentation changes associated with the refactoring have made this PR rather large. That said, this contains no functional changes except for two small ones:
* the key-based destructor fallback now, by virtue of sharing the implementation used by macOS and others, stores its list in a `#[thread_local]` static instead of in the key, eliminating one indirection layer and drastically simplifying its code.
* I've switched over ZKVM (tier 3) to use the same implementation as WebAssembly, as the implementation was just a way worse version of that
Please let me know if I can make this easier to review! I know these large PRs aren't optimal, but I couldn't think of any good intermediate steps.
`@rustbot` label +A-thread-locals
minor : Fix duplicate snippets showing up on hover.
With each `config::apply_change` duplicate configs were being added.
Now we first drain the vec that holds these and then start adding. This fixes#17485
internal: Some more small memory optimizations
Not a big impact on metrics, though there are some more savings in queries mainly used by the IDE layer from this
fix: Improve hover text in unlinked file diagnostics
Use full sentences, and mention how to disable the diagnostic if users are intentionally working on unowned files.
(Full disclosure: I've tested a rust-analyzer build in VS Code, but the pop-up logic is currently disabled due to #17062, so I haven't tested that.)
fix: pattern completions in let-stmt
fix#17480.
We can write `let S { a, b } = s;` or `let Some(x) = a else {}`, so it is reasonable to allow pattern completions in `LetStmt`.
Simplify some term search tactics
Working on the paper `@phijor` found that "Data constructor" tactic could be simplified quite a bit by running it only in the backwards direction. With n+1 rounds it has same coverage as previous implementation in n rounds, however the tactic it self is more simple and also potentially faster as there is less to do.
In a nutshell the idea is to only work with types in the wish-list rather than with any types.
Turns out it is quite a bit faster:
Before:
```
ripgrep:
Tail Expr syntactic hits: 238/1692 (14%)
Tail Exprs found: 1223/1692 (72%)
Term search avg time: 15ms
nalgebra:
Tail Expr syntactic hits: 125/3001 (4%)
Tail Exprs found: 2143/3001 (71%)
Term search avg time: 849ms
```
After
````
ripgrep:
Tail Expr syntactic hits: 246/1692 (14%)
Tail Exprs found: 1209/1692 (71%)
Term search avg time: 8ms
nalgebra:
Tail Expr syntactic hits: 125/3001 (4%)
Tail Exprs found: 2028/3001 (67%)
Term search avg time: 305ms
````
_Also removed niche optimization of removing scope defs from the search space as this wasn't helping much anyway and made code a bit more complex._
Remove confusing `use_polonius` flag and do less cloning
The `use_polonius` flag is both redundant and confusing since every function it's propagated to also checks if `all_facts` is `Some`, the true test of whether to generate Polonius facts for Polonius or for external consumers. This PR makes that path clearer by simply doing away with the argument and handling the logic in precisely two places: where facts are populated (check for `Some`), and where `all_facts` are initialised. It also delays some statements until after that check to avoid the miniscule performance penalty of executing them when Polonius is disabled.
This also addresses `@lqd's` concern in #125652 by reducing the size of what is cloned out of Polonius facts to just the facts being added, as opposed to the entire vector of potential inputs, and added descriptive comments.
*Reviewer note*: the comments in `add_extra_drop_facts` should be inspected by a reviewer, in particular the one on [L#259](https://github.com/rust-lang/rust/compare/master...amandasystems:you-dropped-this-again?expand=1#diff-aa727290e6670264df2face84f012897878e11a70e9c8b156543cfcd9619bac3R259) in this PR, which should be trivial for someone with the right background knowledge to address.
I also included some lints I found on the way there that I couldn't help myself from addressing.
