Uplift `clippy::double_neg` lint as `double_negations`
Warns about cases like this:
```rust
fn main() {
let x = 1;
let _b = --x; //~ WARN use of a double negation
}
```
The intent is to keep people from thinking that `--x` is a prefix decrement operator. `++x`, `x++` and `x--` are invalid expressions and already have a helpful diagnostic.
I didn't add a machine-applicable suggestion to the lint because it's not entirely clear what the programmer was trying to achieve with the `--x` operation. The code that triggers the lint should always be reviewed manually.
Closes#82987
- `check-pass` test for a MRE of #135020
- fail test for #135138
- switch to `TooGeneric` for checking CMSE fn signatures
- switch to `TooGeneric` for compute `SizeSkeleton` (for transmute)
- fix broken tests
Consistently use the highest bit of vector masks when converting to i1 vectors
This improves the codegen for vector `select`, `gather`, `scatter` and boolean reduction intrinsics and fixesrust-lang/portable-simd#316.
The current behavior of most mask operations during llvm codegen is to truncate the mask vector to <N x i1>, telling llvm to use the least significat bit. The exception is the `simd_bitmask` intrinsics, which already used the most signifiant bit.
Since sse/avx instructions are defined to use the most significant bit, truncating means that llvm has to insert a left shift to move the bit into the most significant position, before the mask can actually be used.
Similarly on aarch64, mask operations like blend work bit by bit, repeating the least significant bit across the whole lane involves shifting it into the sign position and then comparing against zero.
By shifting before truncating to <N x i1>, we tell llvm that we only consider the most significant bit, removing the need for additional shift instructions in the assembly.
This improves the codegen for vector `select`, `gather`, `scatter` and
boolean reduction intrinsics and fixesrust-lang/portable-simd#316.
The current behavior of most mask operations during llvm codegen is to
truncate the mask vector to <N x i1>, telling llvm to use the least
significat bit. The exception is the `simd_bitmask` intrinsics, which
already used the most signifiant bit.
Since sse/avx instructions are defined to use the most significant bit,
truncating means that llvm has to insert a left shift to move the bit
into the most significant position, before the mask can actually be
used.
Similarly on aarch64, mask operations like blend work bit by bit,
repeating the least significant bit across the whole lane involves
shifting it into the sign position and then comparing against zero.
By shifting before truncating to <N x i1>, we tell llvm that we only
consider the most significant bit, removing the need for additional
shift instructions in the assembly.
Fix tests on LLVM 20
For sparcv8plus.rs, duplicate the test for LLVM 19 and LLVM 20. LLVM 20 resolves one of the FIXME in the test.
For x86_64-bigint-add.rs split the check lines for LLVM 19 and LLVM 20. The difference in codegen here is due to a difference in unroll factor, which I believe is not what the test is interested in.
Fixes https://github.com/rust-lang/rust/issues/132957.
Fixes https://github.com/rust-lang/rust/issues/133754.
This method will be removed in the future as it produces a broken ABI
that depends on cg_llvm implementation details. After this PR
wasm32-unknown-unknown is the only remaining user of
make_direct_deprecated().
Rollup of 7 pull requests
Successful merges:
- #133631 (Support QNX 7.1 with `io-sock`+libstd and QNX 8.0 (`no_std` only))
- #134358 (compiler: Set `target_abi = "ilp32e"` on all riscv32e targets)
- #135812 (Fix GDB `OsString` provider on Windows )
- #135842 (TRPL: more backward-compatible Edition changes)
- #135946 (Remove extra whitespace from rustdoc breadcrumbs for copypasting)
- #135953 (ci.py: check the return code in `run-local`)
- #136019 (Add an `unchecked_div` alias to the `Div<NonZero<_>>` impls)
r? `@ghost`
`@rustbot` modify labels: rollup
The `Box::new(T::default())` implementation of `Box::default` only
had two stack copies in debug mode, compared to the current version,
which has four. By avoiding creating any `MaybeUninit<T>`'s and just writing
`T` directly to the `Box` pointer, the stack usage in debug mode remains
the same as the old version.
compiler: Set `target_abi = "ilp32e"` on all riscv32e targets
This allows compile-time configuration based on this. In the near future we should do this across all RISCV targets, probably, but this cfg is essential for building software usable on these targets, and they are tier 3 so it seems less of a concern to tweak their definition thusly.
Support QNX 7.1 with `io-sock`+libstd and QNX 8.0 (`no_std` only)
Changes of this pull request:
1. Refactor code for qnx nto targets to share more code in file `nto_qnx.rs`
1. Add support for an additional network stack on nto qnx 7.1.
QNX 7.1 supports two network stacks:
1. `io-pkt`, which is default
2. `io-sock`, which is optional on 7.1 but default in QNX 8.0
As one can see in the [io-sock migration notes](https://www.qnx.com/developers/docs/7.1/index.html#com.qnx.doc.neutrino.io_sock/topic/migrate_app.html), this changes the libc API in a way similar to e.g. linux-gnu vs. linux-musl.
This change adds a new target which has a different value for `target_env`, so that e.g. libc can distinguish between both APIs.
2. Add initial support for QNX 8.0, thanks to AkhilTThomas. As it turned out, the problem with forking many processes still exists in QNX 8.0. Because if this, we are now using it for any QNX version (i.e. not check for `target_env` anymore).
Account for mutable borrow in argument suggestion
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
instead of
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
Fix#136028.
use `PassMode::Direct` for vector types on `s390x`
closes https://github.com/rust-lang/rust/issues/135744
tracking issue: https://github.com/rust-lang/rust/issues/130869
Previously, all vector types were type erased to `Ni8`, now we pass non-wrapped vector types directly. That skips emitting a bunch of casting logic in rustc, that LLVM then has to clean up. The initial LLVM IR is also a bit more readable.
This calling convention is tested extensively in `tests/assembly/s390x-vector-abi.rs`, showing that this change has no impact on the ABI in practice.
r? ````@taiki-e````
Make the wasm_c_abi future compat warning a hard error
This is the next step in getting rid of the broken C abi for wasm32-unknown-unknown.
The lint was made deny-by-default in https://github.com/rust-lang/rust/pull/129534 3 months ago. This still keeps the `-Zwasm-c-abi` flag set to `legacy` by default. It will be flipped in a future PR.
cc https://github.com/rust-lang/rust/issues/122532
Improve check-cfg expected names diagnostic
This PR improves the check-cfg `allow-same-level` test by ~~normalizing it's output and by~~ adding more context to the test.
It also filters the well known cfgs from the `expected names are` note, as to reduce the size of the diagnostic. Users can still find the full list on the [rustc book](https://doc.rust-lang.org/nightly/rustc/check-cfg.html#well-known-names-and-values), which is reinforced for Cargo users by adding a note in the Cargo check-cfg specific section.
Fixes https://github.com/rust-lang/rust/issues/135995
r? `@jieyouxu`
- Don't show environment variables. Seeing PATH is almost never useful, and it can be extremely long.
- For .rlibs in the sysroot, replace crate hashes with a `"-*"` string. This will expand to the full crate name when pasted into the shell.
- Move `.rlib` to outside the glob.
- Abbreviate the sysroot path to `<sysroot>` wherever it appears in the arguments.
This also adds an example of the linker output as a run-make test. Currently it only runs on x86_64-unknown-linux-gnu, because each platform has its own linker arguments. So that it's stable across machines, pass BUILD_ROOT as an argument through compiletest through to run-make tests.
- Only use linker-flavor=gnu-cc if we're actually going to compare the output. It doesn't exist on MacOS.
Reword resolve errors caused by likely missing crate in dep tree
Reword label and add `help`:
```
error[E0432]: unresolved import `some_novel_crate`
--> f704.rs:1:5
|
1 | use some_novel_crate::Type;
| ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `some_novel_crate`
|
= help: if you wanted to use a crate named `some_novel_crate`, use `cargo add some_novel_crate` to add it to your `Cargo.toml`
```
Fix#133137.
Skip suggestions in `derive`d code
Do not suggest
```
help: use parentheses to call these
|
5 | (callback: Rc<dyn Fn()>)(),
| + +++
```
Skip all "call function for this binop" suggestions when in a derive context.
Fix#135989.
Use short ty string for move errors
```
error[E0382]: use of moved value: `x`
--> bay.rs:14:14
|
12 | fn foo(x: D) {
| - move occurs because `x` has type `(((..., ..., ..., ...), ..., ..., ...), ..., ..., ...)`, which does not implement the `Copy` trait
13 | let _a = x;
| - value moved here
14 | let _b = x; //~ ERROR use of moved value
| ^ value used here after move
|
= note: the full type name has been written to 'bay.long-type-14349227078439097973.txt'
= note: consider using `--verbose` to print the full type name to the console
help: consider cloning the value if the performance cost is acceptable
|
13 | let _a = x.clone();
| ++++++++
```
Address 4th case in #135919.
Rename test to `unresolvable-upvar-issue-87987.rs` and add some notes
Extracted from #135756. I had to figure out what this test was trying to test, so I might as well write it down for future reference.
Properly report error when object type param default references self
I accidentally broke this error for cases where a type parameter references `Self` via a projection (i.e. `trait Foo<Arg = Self::Bar> {}`). This PR fixes that, and also makes the error a bit easier to understand.
Fixes#135918
Add `#[optimize(none)]`
cc #54882
This extends the `optimize` attribute to add `none`, which corresponds to the LLVM `OptimizeNone` attribute.
Not sure if an MCP is required for this, happy to file one if so.
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
instead of
```
error: value assigned to `object` is never read
--> $DIR/mut-arg-of-borrowed-type-meant-to-be-arg-of-mut-borrow.rs:21:5
|
LL | object = &mut object2;
| ^^^^^^
|
help: you might have meant to mutate the pointed at value being passed in, instead of changing the reference in the local binding
|
LL ~ fn change_object3(object: &mut mut Object) {
LL |
LL | let object2 = Object;
LL ~ *object = object2;
|
```
Fix#136028.
Don't drop types with no drop glue when building drops for tailcalls
this is required as otherwise drops of `&mut` refs count as a usage of a
'two-phase temporary' causing an ICE.
fixes#128097
The underlying issue is that the current code generates drops for `&mut` which are later counted as a second use of a two-phase temporary:
`bat t.rs -p`
```rust
#![expect(incomplete_features)]
#![feature(explicit_tail_calls)]
fn f(x: &mut ()) {
let _y = String::new();
become f(x);
}
fn main() {}
```
`rustc t.rs -Zdump_mir=f`
```text
error: internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:298:17: found two uses for 2-phase borrow temporary _4: bb2[1] and bb3[0]
--> t.rs:6:5
|
6 | become f(x);
| ^^^^^^^^^^^
thread 'rustc' panicked at compiler/rustc_borrowck/src/borrow_set.rs:298:17:
Box<dyn Any>
stack backtrace:
[REDACTED]
error: aborting due to 1 previous error
```
`bat ./mir_dump/t.f.-------.renumber.0.mir -p -lrust`
```rust
// MIR for `f` 0 renumber
fn f(_1: &mut ()) -> () {
debug x => _1;
let mut _0: ();
let mut _2: !;
let _3: std::string::String;
let mut _4: &mut ();
scope 1 {
debug _y => _3;
}
bb0: {
StorageLive(_3);
_3 = String::new() -> [return: bb1, unwind: bb4];
}
bb1: {
FakeRead(ForLet(None), _3);
StorageLive(_4);
_4 = &mut (*_1);
drop(_3) -> [return: bb2, unwind: bb3];
}
bb2: {
StorageDead(_3);
tailcall f(Spanned { node: move _4, span: t.rs:6:14: 6:15 (#0) });
}
bb3 (cleanup): {
drop(_4) -> [return: bb4, unwind terminate(cleanup)];
}
bb4 (cleanup): {
resume;
}
}
```
Note how `_4 is moved into the tail call in `bb2` and dropped in `bb3`.
This PR adds a check that the locals we drop need dropping.
r? `@oli-obk` (feel free to reassign, I'm not sure who would be a good reviewer, but thought you might have an idea)
cc `@beepster4096,` since you wrote the original drop implementation.
Use short type string in E0308 secondary span label
We were previously printing the full type on the "this expression has type" label.
```
error[E0308]: mismatched types
--> $DIR/secondary-label-with-long-type.rs:8:9
|
LL | let () = x;
| ^^ - this expression has type `((..., ..., ..., ...), ..., ..., ...)`
| |
| expected `((..., ..., ..., ...), ..., ..., ...)`, found `()`
|
= note: expected tuple `((..., ..., ..., ...), ..., ..., ...)`
found unit type `()`
= note: the full type name has been written to '$TEST_BUILD_DIR/diagnostic-width/secondary-label-with-long-type/secondary-label-with-long-type.long-type-3987761834644699448.txt'
= note: consider using `--verbose` to print the full type name to the console
```
Reported in a comment of #135919.
Do not suggest
```
help: use parentheses to call these
|
5 | (callback: Rc<dyn Fn()>)(),
| + +++
```
Skip all "call function for this binop" suggestions when in a derive context.
Fix#135989.
```
error[E0382]: use of moved value: `x`
--> bay.rs:14:14
|
12 | fn foo(x: D) {
| - move occurs because `x` has type `(((..., ..., ..., ...), ..., ..., ...), ..., ..., ...)`, which does not implement the `Copy` trait
13 | let _a = x;
| - value moved here
14 | let _b = x; //~ ERROR use of moved value
| ^ value used here after move
|
= note: the full type name has been written to 'bay.long-type-14349227078439097973.txt'
= note: consider using `--verbose` to print the full type name to the console
help: consider cloning the value if the performance cost is acceptable
|
13 | let _a = x.clone();
| ++++++++
```
