Commit Graph

13392 Commits

Author SHA1 Message Date
Urgau
9cb540a13c Reject leading unsafe in cfg!(...) and --check-cfg. 2024-09-30 12:15:08 +02:00
bors
329e7b4d4e Auto merge of #130983 - GuillaumeGomez:wait-for-false, r=notriddle
Update `browser-ui-test` version and make use of `wait-for*-false` commands

I added `wait-for*-false` commands, making possible these changes.

r? `@notriddle`
2024-09-29 08:22:20 +00:00
bors
1d9162bced Auto merge of #129687 - Urgau:rfc3127-sysroot-2, r=jieyouxu
Implement RFC3137 trim-paths sysroot changes - take 2

This PR is a continuation of https://github.com/rust-lang/rust/pull/118149. Nothing really changed, except for https://github.com/rust-lang/rust/pull/129408 which I was able to trigger locally.

Original description:

> Implement parts of #111540
>
> Right now, backtraces into sysroot always shows /rustc/$hash in diagnostics, e.g.
>
> ```
> thread 'main' panicked at 'hello world', map-panic.rs:2:50
> stack backtrace:
>    0: std::panicking::begin_panic
>              at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/panicking.rs:616:12
>    1: map_panic::main::{{closure}}
>              at ./map-panic.rs:2:50
>    2: core::option::Option<T>::map
>              at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/core/src/option.rs:929:29
>    3: map_panic::main
>              at ./map-panic.rs:2:30
>    4: core::ops::function::FnOnce::call_once
>              at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/core/src/ops/function.rs:248:5
> note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
> ```
>
> [RFC 3127 said](https://rust-lang.github.io/rfcs/3127-trim-paths.html#changing-handling-of-sysroot-path-in-rustc)
>
> > We want to change this behaviour such that, when rust-src source files can be discovered, the virtual path is discarded and therefore the local path will be embedded, unless there is a --remap-path-prefix that causes this local path to be remapped in the usual way.
>
> This PR implements this behaviour. When `rust-src` is present at compile time, rustc replaces /rustc/$hash with a real path into local rust-src with best effort. To sanitise this, users must explicitly supply `--remap-path-prefix=<path to rust-src>=foo`.

cc `@cbeuw`
Fix #105907
Fix #85463

try-job: dist-x86_64-linux
try-job: x86_64-msvc
try-job: dist-x86_64-msvc
try-job: armhf-gnu
2024-09-29 03:04:05 +00:00
bors
55cb7359c7 Auto merge of #123778 - jhorstmann:optimize-upper-lower-auto-vectorization, r=the8472
Improve autovectorization of to_lowercase / to_uppercase functions

Refactor the code in the `convert_while_ascii` helper function to make it more suitable for auto-vectorization and also process the full ascii prefix of the string. The generic case conversion logic will only be invoked starting from the first non-ascii character.

The runtime on a microbenchmark with a small ascii-only input decreases from ~55ns to ~18ns per iteration. The new implementation also reduces the amount of unsafe code and encapsulates all unsafe inside the helper function.

Fixes #123712
2024-09-28 23:56:37 +00:00
Urgau
3a6c6ee3d3 remap-path-prefix-sysroot: remap {{src-base}} as well
This is done to cover the path of the test it-self as it may not live
on the same root directory as {{rust-src-base}}, which can be the case
if {{rust-src-base}} is coming from a extracted dist build (cc opt-dist)
2024-09-28 21:50:23 +02:00
Guillaume Gomez
2f16ff7b37 Make use of wait-for*-false commands 2024-09-28 18:04:00 +02:00
Matthias Krüger
cfe0cff5b9
Rollup merge of #130960 - cuviper:cdylib-soname, r=petrochenkov
Only add an automatic SONAME for Rust dylibs

#126094 added an automatic relative `SONAME` to all dynamic libraries, but it was really only needed for Rust `--crate-type="dylib"`. In Fedora, it was a surprise to see `SONAME` on `"cdylib"` libraries like Python modules, especially because that generates an undesirable RPM `Provides`. We can instead add a `SONAME` just for Rust dylibs by passing the crate-type argument farther.

Ref: https://bugzilla.redhat.com/show_bug.cgi?id=2314879
2024-09-28 15:11:22 +02:00
Matthias Krüger
5d7db93600
Rollup merge of #130953 - workingjubilee:rename-a-few-ctypes-tests, r=fee1-dead
Rename a few tests to make tidy happier

A somewhat random smattering of tests that I have recently looked at, and thus had cause to research and write down the reason for their existence.
2024-09-28 09:35:12 +02:00
Matthias Krüger
58d0730fb8
Rollup merge of #130944 - lukas-code:ptr-ptr-sub, r=compiler-errors
Allow instantiating trait object binder in ptr-to-ptr casts

For unsizing coercions between trait objects with the same principal, we already allow instantiating the for binder. For example, coercing `Box<dyn for<'a> Trait<'a>` to `Box<dyn Trait<'static>>` is allowed.

Since ptr-to-ptr casts will insert an unsizing coercion before the cast if possible, this has the consequence that the following compiles already:

```rust
// This compiles today.
fn cast<'b>(x: *mut dyn for<'a> Trait<'a>) -> *mut dyn Trait<'b> {
    // lowered as (roughly)
    // tmp: *mut dyn Trait<'?0> = Unsize(x)     // requires dyn for<'a> Trait<'a> <: dyn Trait<'?0>
    // ret: *mut dyn Trait<'b> = PtrToPtr(tmp)  // requires dyn Trait<'?0> == dyn Trait<'b>
    x as _
}
```

However, if no unsizing coercion is inserted then this currently fails to compile as one type is more general than the other. This PR will allow this code to compile, too, by changing ptr-to-ptr casts of pointers with vtable metadata to use sutyping instead of type equality.

```rust
// This will compile after this PR.
fn cast<'b>(x: *mut dyn for<'a> Trait<'a>) -> *mut Wrapper<dyn Trait<'b>> {
    // lowered as (roughly)
    // no Unsize here!
    // ret: *mut Wrapper<dyn Trait<'b>> = PtrToPtr(x)  // requires dyn for<'a> Trait<'a> == dyn Trait<'b>
    x as _
}
```

Note that it is already possible to work around the current restrictions and make the code compile before this PR by splitting the cast in two, so this shouldn't allow a new class of programs to compile:

```rust
// Workaround that compiles today.
fn cast<'b>(x: *mut dyn for<'a> Trait<'a>) -> *mut Wrapper<dyn Trait<'b>> {
    x as *mut dyn Trait<'_> as _
}
```

r? `@compiler-errors`
cc `@WaffleLapkin`
2024-09-28 09:35:12 +02:00
Matthias Krüger
2df6b0773e
Rollup merge of #130924 - surechen:fix_130851, r=compiler-errors
Make clashing_extern_declarations considering generic args for ADT field

In following example, G<u16> should be recognized as different from G<u32> :

```rust
#[repr(C)] pub struct G<T> { g: [T; 4] }

pub mod x { extern "C" { pub fn g(_: super::G<u16>); } }
pub mod y { extern "C" { pub fn g(_: super::G<u32>); } }
```

fixes #130851
2024-09-28 09:35:10 +02:00
Matthias Krüger
4e510daed7
Rollup merge of #130866 - compiler-errors:dyn-instantiate-binder, r=lcnr
Allow instantiating object trait binder when upcasting

This PR fixes two bugs (that probably need an FCP).

### We use equality rather than subtyping for upcasting dyn conversions

This code should be valid:

```rust
#![feature(trait_upcasting)]

trait Foo: for<'h> Bar<'h> {}
trait Bar<'a> {}

fn foo(x: &dyn Foo) {
    let y: &dyn Bar<'static> = x;
}
```
But instead:

```
error[E0308]: mismatched types
 --> src/lib.rs:7:32
  |
7 |     let y: &dyn Bar<'static> = x;
  |                                ^ one type is more general than the other
  |
  = note: expected existential trait ref `for<'h> Bar<'h>`
             found existential trait ref `Bar<'_>`
```

And so should this:

```rust
#![feature(trait_upcasting)]

fn foo(x: &dyn for<'h> Fn(&'h ())) {
    let y: &dyn FnOnce(&'static ()) = x;
}
```

But instead:

```
error[E0308]: mismatched types
 --> src/lib.rs:4:39
  |
4 |     let y: &dyn FnOnce(&'static ()) = x;
  |                                       ^ one type is more general than the other
  |
  = note: expected existential trait ref `for<'h> FnOnce<(&'h (),)>`
             found existential trait ref `FnOnce<(&(),)>`
```

Specifically, both of these fail because we use *equality* when comparing the supertrait to the *target* of the unsize goal. For the first example, since our supertrait is `for<'h> Bar<'h>` but our target is `Bar<'static>`, there's a higher-ranked type mismatch even though we *should* be able to instantiate that supertrait binder when upcasting. Similarly for the second example.

### New solver uses equality rather than subtyping for no-op (i.e. non-upcasting) dyn conversions

This code should be valid in the new solver, like it is with the old solver:

```rust
// -Znext-solver

fn foo<'a>(x: &mut for<'h> dyn Fn(&'h ())) {
   let _: &mut dyn Fn(&'a ()) = x;
}
```

But instead:

```
error: lifetime may not live long enough
 --> <source>:2:11
  |
1 | fn foo<'a>(x: &mut dyn for<'h> Fn(&'h ())) {
  |        -- lifetime `'a` defined here
2 |    let _: &mut dyn Fn(&'a ()) = x;
  |           ^^^^^^^^^^^^^^^^^^^ type annotation requires that `'a` must outlive `'static`
  |
  = note: requirement occurs because of a mutable reference to `dyn Fn(&())`
```

Specifically, this fails because we try to coerce `&mut dyn for<'h> Fn(&'h ())` to `&mut dyn Fn(&'a ())`, which registers an `dyn for<'h> Fn(&'h ()): dyn Fn(&'a ())` goal. This fails because the new solver uses *equating* rather than *subtyping* in `Unsize` goals.

This is *mostly* not a problem... You may wonder why the same code passes on the new solver for immutable references:

```
// -Znext-solver

fn foo<'a>(x: &dyn Fn(&())) {
   let _: &dyn Fn(&'a ()) = x; // works
}
```

That's because in this case, we first try to coerce via `Unsize`, but due to the leak check the goal fails. Then, later in coercion, we fall back to a simple subtyping operation, which *does* work.

Since `&T` is covariant over `T`, but `&mut T` is invariant, that's where the discrepancy between these two examples crops up.

---

r? lcnr or reassign :D
2024-09-28 09:35:09 +02:00
Josh Stone
f46057bf1c Only add an automatic SONAME for Rust dylibs 2024-09-27 15:53:26 -07:00
Jubilee Young
19d5568ad3 tests: issue-34798.rs => allow-phantomdata-in-ffi.rs 2024-09-27 14:29:34 -07:00
bors
83e4e18896 Auto merge of #130946 - matthiaskrgr:rollup-ia4mf0y, r=matthiaskrgr
Rollup of 6 pull requests

Successful merges:

 - #130718 (Cleanup some known-bug issues)
 - #130730 (Reorganize Test Headers)
 - #130826 (Compiler: Rename "object safe" to "dyn compatible")
 - #130915 (fix typo in triagebot.toml)
 - #130926 (Update cc to 1.1.22 in library/)
 - #130932 (etc: Add sample rust-analyzer configs for eglot & helix)

r? `@ghost`
`@rustbot` modify labels: rollup
2024-09-27 21:23:29 +00:00
Jubilee Young
a1fbf251b8 tests: issue-14309.* => repr-rust-is-undefined.* 2024-09-27 14:20:31 -07:00
Jubilee Young
bcf8cf2943 tests: issue-69488.rs => load-preserves-partial-init-issue-69488.rs 2024-09-27 14:18:11 -07:00
Matthias Krüger
a935064fae
Rollup merge of #130826 - fmease:compiler-mv-obj-safe-dyn-compat, r=compiler-errors
Compiler: Rename "object safe" to "dyn compatible"

Completed T-lang FCP: https://github.com/rust-lang/lang-team/issues/286#issuecomment-2338905118.
Tracking issue: https://github.com/rust-lang/rust/issues/130852

Excludes `compiler/rustc_codegen_cranelift` (to be filed separately).
Includes Stable MIR.

Regarding https://github.com/rust-lang/rust/labels/relnotes, I guess I will manually open a https://github.com/rust-lang/rust/labels/relnotes-tracking-issue since this change affects everything (compiler, library, tools, docs, books, everyday language).

r? ghost
2024-09-27 21:35:08 +02:00
Matthias Krüger
ae43f27f83
Rollup merge of #130730 - veera-sivarajan:clean-test-headers, r=compiler-errors
Reorganize Test Headers

This PR moves the test headers to the top in a couple of test files to maintain consistent style.

Based on this comment: https://github.com/rust-lang/rust/pull/130665#discussion_r1770506261
2024-09-27 21:35:08 +02:00
Matthias Krüger
65196ca4a9
Rollup merge of #130718 - jackh726:known-bug-cleanup, r=compiler-errors
Cleanup some known-bug issues

I went through most of the known-bug tests (except those under `tests/crashes`) and made sure the issue had the `S-bug-has-test` label and checked that the linked issue was open. This is a bunch of cleanups, mainly issues that have been closed and the tests should have been updated.

Importantly, there are many known-bug tests linking to #110395. This *probably* isn't right - that is a tracking issue. But I don't really know what the "right" thing to do here. Probably, most that are actually *supposed* to be tests for const trait need to be linked to *that* tracking issue. And any other tests that were mislabeled need to be handled accordingly e.g. #130482. cc `@fee1-dead`
2024-09-27 21:35:07 +02:00
Lukas Markeffsky
53f45c4332 borrowck: use subtyping instead of equality for ptr-to-ptr casts 2024-09-27 21:04:32 +02:00
Lukas Markeffsky
8302f2e35f add even more tests for ptr-to-ptr casts on trait objects 2024-09-27 21:04:32 +02:00
Jack Huey
e5e1fadc2b Cleanup some known-bug issues 2024-09-27 18:15:37 +00:00
Matthias Krüger
01fecf60ef
Rollup merge of #130917 - gurry:129503-ice-wrong-span-in-macros, r=chenyukang
Fix error span if arg to `asm!()` is a macro call

Fixes #129503

When the argument to `asm!()` is a macro call, e.g. `asm!(concat!("abc", "{} pqr"))`, and there's an error in the resulting template string, we do not take into account the presence of this macro call while computing the error span. This PR fixes that. Now we will use the entire thing between the parenthesis of `asm!()` as the error span in this situation e.g. for `asm!(concat!("abc", "{} pqr"))` the error span will be `concat!("abc", "{} pqr")`.
2024-09-27 19:08:01 +02:00
Matthias Krüger
fd9d961ed8
Rollup merge of #130873 - taiki-e:ppc64-atomic, r=Amanieu
rustc_target: Add powerpc64 atomic-related features

This adds the following two target features to unstable powerpc_target_feature.

- `partword-atomics`: 8-bit and 16-bit atomic instructions (`l{b,h}arx` and `st{b,h}cx.`) ([definition in LLVM](https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/PowerPC/PPC.td#L170-L172))
- `quadword-atomics`: 128-bit atomic instructions (`lqarx` and `stqcx.`) ([definition in LLVM](https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/PowerPC/PPC.td#L173-L175))

Both features are [available on power8+](https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/PowerPC/PPC.td#L408-L422), so enabled by default for `powerpc64le-*` targets.

r? `@Amanieu`

`@rustbot` label +O-PowerPC
2024-09-27 19:08:00 +02:00
Urgau
8075ddb98e Implement RFC3137 trim-paths sysroot changes 2024-09-27 13:27:54 +02:00
surechen
0bf928968b Make clashing_extern_declarations considering generic args for ADT field
fixes #130851
2024-09-27 16:37:43 +08:00
Jubilee
b463bd1f27
Rollup merge of #130912 - estebank:point-at-arg-type, r=compiler-errors
On implicit `Sized` bound on fn argument, point at type instead of pattern

Instead of

```
error[E0277]: the size for values of type `(dyn ThriftService<(), AssocType = _> + 'static)` cannot be known at compilation time
  --> $DIR/issue-59324.rs:23:20
   |
LL | fn with_factory<H>(factory: dyn ThriftService<()>) {}
   |                    ^^^^^^^ doesn't have a size known at compile-time
```

output

```
error[E0277]: the size for values of type `(dyn ThriftService<(), AssocType = _> + 'static)` cannot be known at compilation time
  --> $DIR/issue-59324.rs:23:29
   |
LL | fn with_factory<H>(factory: dyn ThriftService<()>) {}
   |                             ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
```
2024-09-26 22:20:57 -07:00
Jubilee
6b0c897499
Rollup merge of #130911 - notriddle:notriddle/suggest-wrap-parens-fn-pointer, r=compiler-errors
diagnostics: wrap fn cast suggestions in parens when needed

Fixes #121632
2024-09-26 22:20:56 -07:00
Gurinder Singh
3dd583d540 Fix error span when arg to asm!() is a macro call
When the template string passed to asm!() is produced by
a macro call like concat!() we were producing wrong error
spans. Now in the case of a macro call we just use the entire
arg to asm!(), macro call and all, as the error span.
2024-09-27 09:49:15 +05:30
Michael Goulet
d4ee408afc Check allow instantiating object trait binder when upcasting and in new solver 2024-09-26 22:26:29 -04:00
Michael Howell
c48b0d4eb4 diagnostics: wrap fn cast suggestions in parens
Fixes #121632
2024-09-26 18:17:52 -07:00
Esteban Küber
c7d171d771 On implicit Sized bound on fn argument, point at type instead of pattern
Instead of

```
error[E0277]: the size for values of type `(dyn ThriftService<(), AssocType = _> + 'static)` cannot be known at compilation time
  --> $DIR/issue-59324.rs:23:20
   |
LL | fn with_factory<H>(factory: dyn ThriftService<()>) {}
   |                    ^^^^^^^ doesn't have a size known at compile-time
```

output

```
error[E0277]: the size for values of type `(dyn ThriftService<(), AssocType = _> + 'static)` cannot be known at compilation time
  --> $DIR/issue-59324.rs:23:29
   |
LL | fn with_factory<H>(factory: dyn ThriftService<()>) {}
   |                             ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
```
2024-09-27 00:45:02 +00:00
Guillaume Gomez
ed902a8a58
Rollup merge of #130879 - fmease:fix-diag-ice, r=compiler-errors
Pass correct HirId to late_bound_vars in diagnostic code

Fixes #130858.
Fixes #125655.
Fixes #130391.
Fixes #130663.

r? compiler-errors
2024-09-27 00:43:35 +02:00
Guillaume Gomez
d3cb1ce0a0
Rollup merge of #130833 - makai410:master, r=compiler-errors,fee1-dead
Fix the misleading diagnostic for `let_underscore_drop` on type without `Drop` implementation

Closes: #130430
r? rust-lang/diagnostics
2024-09-27 00:43:32 +02:00
Guillaume Gomez
0acddf5060
Rollup merge of #130820 - 91khr:fix-coroutine-unit-arg, r=compiler-errors
Fix diagnostics for coroutines with () as input.

This may be a more real-life example to trigger the diagnostic:

```rust
#![features(try_blocks, coroutine_trait, coroutines)]

use std::ops::Coroutine;

struct Request;
struct Response;
fn get_args() -> Result<String, String> { todo!() }
fn build_request(_arg: String) -> Request { todo!() }
fn work() -> impl Coroutine<Option<Response>, Yield = Request> {
    #[coroutine]
    |_| {
        let r: Result<(), String> = try {
            let req = get_args()?;
            yield build_request(req)
        };
        if let Err(msg) = r {
            eprintln!("Error: {msg}");
        }
    }
}
```
2024-09-27 00:43:31 +02:00
León Orell Valerian Liehr
e29ff8c058
Pass correct HirId to late_bound_vars in diagnostic code 2024-09-26 19:26:08 +02:00
Ding Xiang Fei
1576a6d618
Stabilize const_refs_to_static
update tests

fix bitwidth-sensitive stderr output

use build-fail for asm tests
2024-09-26 13:21:15 +02:00
Taiki Endo
36455c6f6b rustc_target: Add powerpc64 atomic-related features 2024-09-26 16:43:04 +09:00
bors
76ed7a1fa4 Auto merge of #130329 - khuey:reorder-constant-spills, r=davidtwco
Reorder stack spills so that constants come later.

Currently constants are "pulled forward" and have their stack spills emitted first. This confuses LLVM as to where to place breakpoints at function entry, and results in argument values being wrong in the debugger. It's straightforward to avoid emitting the stack spills for constants until arguments/etc have been introduced in debug_introduce_locals, so do that.

Example LLVM IR (irrelevant IR elided):
Before:
```
define internal void `@_ZN11rust_1289457binding17h2c78f956ba4bd2c3E(i64` %a, i64 %b, double %c) unnamed_addr #0 !dbg !178 { start:
  %c.dbg.spill = alloca [8 x i8], align 8
  %b.dbg.spill = alloca [8 x i8], align 8
  %a.dbg.spill = alloca [8 x i8], align 8
  %x.dbg.spill = alloca [4 x i8], align 4
  store i32 0, ptr %x.dbg.spill, align 4, !dbg !192            ; LLVM places breakpoint here.
    #dbg_declare(ptr %x.dbg.spill, !190, !DIExpression(), !192)
  store i64 %a, ptr %a.dbg.spill, align 8
    #dbg_declare(ptr %a.dbg.spill, !187, !DIExpression(), !193)
  store i64 %b, ptr %b.dbg.spill, align 8
    #dbg_declare(ptr %b.dbg.spill, !188, !DIExpression(), !194)
  store double %c, ptr %c.dbg.spill, align 8
    #dbg_declare(ptr %c.dbg.spill, !189, !DIExpression(), !195)
  ret void, !dbg !196
}
```
After:
```
define internal void `@_ZN11rust_1289457binding17h2c78f956ba4bd2c3E(i64` %a, i64 %b, double %c) unnamed_addr #0 !dbg !178 { start:
  %x.dbg.spill = alloca [4 x i8], align 4
  %c.dbg.spill = alloca [8 x i8], align 8
  %b.dbg.spill = alloca [8 x i8], align 8
  %a.dbg.spill = alloca [8 x i8], align 8
  store i64 %a, ptr %a.dbg.spill, align 8
    #dbg_declare(ptr %a.dbg.spill, !187, !DIExpression(), !192)
  store i64 %b, ptr %b.dbg.spill, align 8
    #dbg_declare(ptr %b.dbg.spill, !188, !DIExpression(), !193)
  store double %c, ptr %c.dbg.spill, align 8
    #dbg_declare(ptr %c.dbg.spill, !189, !DIExpression(), !194)
  store i32 0, ptr %x.dbg.spill, align 4, !dbg !195            ; LLVM places breakpoint here.
    #dbg_declare(ptr %x.dbg.spill, !190, !DIExpression(), !195)
  ret void, !dbg !196
}
```
Note in particular the position of the "LLVM places breakpoint here" comment relative to the stack spills for the function arguments. LLVM assumes that the first instruction with with a debug location is the end of the prologue. As LLVM does not currently offer front ends any direct control over the placement of the prologue end reordering the IR is the only mechanism available to fix argument values at function entry in the presence of MIR optimizations like SingleUseConsts. Fixes #128945

r? `@michaelwoerister`
2024-09-26 02:37:52 +00:00
makai410
58921874cb Fix the misleading diagnostic for let_underscore_drop on type without Drop implementation 2024-09-26 10:18:18 +08:00
bors
9e394f551c Auto merge of #120752 - compiler-errors:more-relevant-bounds, r=lcnr
Collect relevant item bounds from trait clauses for nested rigid projections

Rust currently considers trait where-clauses that bound the trait's *own* associated types to act like an item bound:

```rust
trait Foo where Self::Assoc: Bar { type Assoc; }
// acts as if:
trait Foo { type Assoc: Bar; }
```

### Background

This behavior has existed since essentially forever (i.e. before Rust 1.0), since we originally started out by literally looking at the where clauses written on the trait when assembling `SelectionCandidate::ProjectionCandidate` for projections. However, looking at the predicates of the associated type themselves was not sound, since it was unclear which predicates were *assumed* and which predicates were *implied*, and therefore this was reworked in #72788 (which added a query for the predicates we consider for `ProjectionCandidate`s), and then finally item bounds and predicates were split in #73905.

### Problem 1: GATs don't uplift bounds correctly

All the while, we've still had logic to uplift associated type bounds from a trait's where clauses. However, with the introduction of GATs, this logic was never really generalized correctly for them, since we were using simple equality to test if the self type of a trait where clause is a projection. This leads to shortcomings, such as:

```rust
trait Foo
where
    for<'a> Self::Gat<'a>: Debug,
{
    type Gat<'a>;
}

fn test<T: Foo>(x: T::Gat<'static>) {
    //~^ ERROR `<T as Foo>::Gat<'a>` doesn't implement `Debug`
    println!("{:?}", x);
}
```

### Problem 2: Nested associated type bounds are not uplifted

We also don't attempt to uplift bounds on nested associated types, something that we couldn't really support until #120584. This can be demonstrated best with an example:

```rust
trait A
    where Self::Assoc: B,
    where <Self::Assoc as B>::Assoc2: C,
{
    type Assoc; // <~ The compiler *should* treat this like it has an item bound `B<Assoc2: C>`.
}

trait B { type Assoc2; }
trait C {}

fn is_c<T: C>() {}

fn test<T: A>() {
    is_c::<<Self::Assoc as B>::Assoc2>();
    //~^ ERROR the trait bound `<<T as A>::Assoc as B>::Assoc2: C` is not satisfied
}
```

Why does this matter?

Well, generalizing this behavior bridges a gap between the associated type bounds (ATB) feature and trait where clauses. Currently, all bounds that can be stably written on associated types can also be expressed as where clauses on traits; however, with the stabilization of ATB, there are now bounds that can't be desugared in the same way. This fixes that.

## How does this PR fix things?

First, when scraping item bounds from the trait's where clauses, given a trait predicate, we'll loop of the self type of the predicate as long as it's a projection. If we find a projection whose trait ref matches, we'll uplift the bound. This allows us to uplift, for example `<Self as Trait>::Assoc: Bound` (pre-existing), but also `<<Self as Trait>::Assoc as Iterator>::Item: Bound` (new).

If that projection is a GAT, we will check if all of the GAT's *own* args are all unique late-bound vars. We then map the late-bound vars to early-bound vars from the GAT -- this allows us to uplift `for<'a, 'b> Self::Assoc<'a, 'b>: Trait` into an item bound, but we will leave `for<'a> Self::Assoc<'a, 'a>: Trait` and `Self::Assoc<'static, 'static>: Trait` alone.

### Okay, but does this *really* matter?

I consider this to be an improvement of the status quo because it makes GATs a bit less magical, and makes rigid projections a bit more expressive.
2024-09-25 21:12:07 +00:00
Michael Goulet
c5914753ad Add a few more tests, comments 2024-09-25 13:13:04 -04:00
Michael Goulet
2dacf7ac61 Collect relevant item bounds from trait clauses for nested rigid projections, GATs 2024-09-25 13:13:04 -04:00
Michael Goulet
8fc8e03150 Validate unsize coercion in MIR validation 2024-09-25 11:10:38 -04:00
León Orell Valerian Liehr
01a063f9df
Compiler: Rename "object safe" to "dyn compatible" 2024-09-25 13:26:48 +02:00
Virginia Senioria
986e20d5bb Fixed diagnostics for coroutines with () as input. 2024-09-25 08:45:40 +00:00
Matthias Krüger
e5b9d93579
Rollup merge of #130787 - compiler-errors:next-solver-gce, r=BoxyUwU
Ban combination of GCE and new solver

These do not work together. I don't want anyone to have the impression that they do.

I reused the conflicting features diagnostic but I guess I could make it more tailored to the new solver? OTOH I don't really about the presentation of diagnostics here; these are nightly features after all.

r? `@BoxyUwU` thoughts on this?
2024-09-25 10:09:23 +02:00
Matthias Krüger
0e439090cb
Rollup merge of #130734 - Luv-Ray:fix_vfe, r=lcnr
Fix: ices on virtual-function-elimination about principal trait

Extract `load_vtable` function to ensure the `virtual_function_elimination` option is always checked.
It's okay not to use `llvm.type.checked.load` to load the vtable if there is no principal trait.

Fixes #123955
Fixes #124092
2024-09-25 10:09:23 +02:00
Matthias Krüger
508b433e27
Rollup merge of #130549 - biabbas:riscv32_wrs_vxworks, r=nnethercote
Add RISC-V vxworks targets

Risc-V 32 and RISC-V 64 targets are to be added in the target list.
2024-09-25 10:09:22 +02:00
bors
1b5aa96d60 Auto merge of #130807 - tgross35:rollup-p304vzf, r=tgross35
Rollup of 7 pull requests

Successful merges:

 - #130234 (improve compile errors for invalid ptr-to-ptr casts with trait objects)
 - #130752 (Improve assembly test for CMSE ABIs)
 - #130764 (Separate collection of crate-local inherent impls from error tracking)
 - #130788 (Pin memchr to 2.5.0 in the library rather than rustc_ast)
 - #130789 (add InProgress ErrorKind gated behind io_error_inprogress feature)
 - #130793 (Mention `COMPILETEST_VERBOSE_CRASHES` on crash test failure)
 - #130798 (rustdoc: inherit parent's stability where applicable)

Failed merges:

 - #130735 (Simple validation for unsize coercion in MIR validation)

r? `@ghost`
`@rustbot` modify labels: rollup
2024-09-25 02:06:55 +00:00