Like we have `add`/`sub` which are the `usize` version of `offset`, this adds the `usize` equivalent of `offset_from`. Like how `.add(d)` replaced a whole bunch of `.offset(d as isize)`, you can see from the changes here that it's fairly common that code actually knows the order between the pointers and *wants* a `usize`, not an `isize`.
As a bonus, this can do `sub nuw`+`udiv exact`, rather than `sub`+`sdiv exact`, which can be optimized slightly better because it doesn't have to worry about negatives. That's why the slice iterators weren't using `offset_from`, though I haven't updated that code in this PR because slices are so perf-critical that I'll do it as its own change.
This is an intrinsic, like `offset_from`, so that it can eventually be allowed in CTFE. It also allows checking the extra safety condition -- see the test confirming that CTFE catches it if you pass the pointers in the wrong order.
Implement a lint to warn about unused macro rules
This implements a new lint to warn about unused macro rules (arms/matchers), similar to the `unused_macros` lint added by #41907 that warns about entire macros.
```rust
macro_rules! unused_empty {
(hello) => { println!("Hello, world!") };
() => { println!("empty") }; //~ ERROR: 1st rule of macro `unused_empty` is never used
}
fn main() {
unused_empty!(hello);
}
```
Builds upon #96149 and #96156.
Fixes#73576
Gracefully fail to resolve associated items instead of `delay_span_bug`.
`codegen_fulfill_obligation` is used during instance resolution for trait items.
In case of insufficient normalization issues during MIR inlining, it caused ICEs.
It's better to gracefully refuse to resolve the associated item, and let the caller decide what to do with this.
Split from https://github.com/rust-lang/rust/pull/91743Closes#69121Closes#73021Closes#88599Closes#93008Closes#93248Closes#94680Closes#96170
r? `@oli-obk`
tighten sanity checks around Scalar and ScalarPair
While investigating https://github.com/rust-lang/rust/issues/96185 I noticed codegen has tighter sanity checks here than Miri does, so I added some more assertions. Strangely, some of them fail, so I also needed to add a HACK... that is probably worth looking into.
This does not fix that issue, but it changes the ICE messages, making it quite clear that we have a scalar whose size is not the same as that of the surrounding layout.
r? `@oli-obk`
logging: add env var to control verbose scope entry/exit logging
~~This got removed in https://github.com/rust-lang/rust/pull/75143, and I find this makes long traces a lot harder to read, so I propose we add this back.~~
Example trace:
```
│ │ ├─0ms INFO rustc_const_eval::interpret::step return
│ │ ├─0ms INFO rustc_const_eval::interpret::eval_context popping stack frame (returning from function)
│ │┌┘rustc_const_eval::interpret::eval_context::frame std::ptr::mut_ptr::<impl *mut u8>::guaranteed_eq
│ ├┘rustc_const_eval::interpret::eval_context::frame std::ptr::mut_ptr::<impl *mut u8>::is_null
│ ├─1ms INFO rustc_const_eval::interpret::step // executing bb2
│ ├─1ms INFO rustc_const_eval::interpret::step StorageDead(_4)
│ ├─1ms INFO rustc_const_eval::interpret::step StorageDead(_2)
│ ├─1ms INFO rustc_const_eval::interpret::step return
│ ├─1ms INFO rustc_const_eval::interpret::eval_context popping stack frame (returning from function)
│┌┘rustc_const_eval::interpret::eval_context::frame std::ptr::mut_ptr::<impl *mut u8>::is_null
├┘rustc_const_eval::interpret::eval_context::frame std::sys_common::thread_local_dtor::register_dtor_fallback::run_dtors
├─178ms INFO rustc_const_eval::interpret::step // executing bb2
├─178ms INFO rustc_const_eval::interpret::step StorageDead(_5)
```
r? `@oli-obk`
Fix inaccurate function name in `rustc_const_eval` docs
Looks to me like this fixes#85513. I had trouble making a intra-docs link to `eval_place_to_op` work, though...
Use lifetimes on type-alias-impl-trait used in function signatures to infer output type lifetimes
fixes https://github.com/rust-lang/rust/issues/96564
TLDR:
```rust
fn execute(ty: Ty<'_>) -> &str { todo!() }
```
(`Ty` being a type alias impl trait) used to produce the following error before this PR
```
error[E0581]: return type references an anonymous lifetime, which is not constrained by the fn input types
--> src/lib.rs:4:27
|
4 | fn execute(ty: Ty<'_>) -> &str { todo!() }
| ^^^^
|
= note: lifetimes appearing in an associated type are not considered constrained
```
Remove hacks in `make_token_stream`.
`make_tokenstream` has three commented hacks, and a comment at the top
referring to #67062. These hacks have no observable effect, at least as judged
by running the test suite. The hacks were added in #82608, with an explanation
[here](https://github.com/rust-lang/rust/pull/82608#issuecomment-812877329). It
appears that one of the following is true: (a) they never did anything useful,
(b) they do something useful but we have no test coverage for them, or (c)
something has changed in the meantime that means they are no longer necessary.
This commit removes the hacks and the comments, in the hope that (b) is not
true.
r? `@Aaron1011`
Use `FxIndexSet` to avoid sorting fake borrows
This fixes#96449, but I haven't yet been able to
make the reproducer work using `#[cfg]` attributes,
so we can't use the 'revision' infra to write a test
The previous implementation relied on sorting by `PlaceRef`.
This requires sorting by a `DefId`, which uses untracked state
(see #93315)
In #95604 the compiler started generating a temporary symbols.o which is added
to the linker invocation. This object file has an `e_flags` which may be invalid
for 32-bit MIPS targets. Even though symbols.o doesn't contain code, linking
with [lld fails](https://github.com/llvm/llvm-project/blob/main/lld/ELF/Arch/MipsArchTree.cpp#L79) with
```
rust-lld: error: foo-cgu.0.rcgu.o: ABI 'o32' is incompatible with target ABI 'n64'
```
because it omits the ABI bits (EF_MIPS_ABI_O32) so lld assumes it's using the
N64 ABI. This breaks linking on nightly for the out-of-tree [psx
target](https://github.com/ayrtonm/psx-sdk-rs/issues/9), the builtin
mipsel-sony-psp target (cc @overdrivenpotato) and any other 32-bit MIPS
target using lld.
This PR sets the ABI in `e_flags` to O32 since that's the only ABI for 32-bit
MIPS that LLVM supports. It also sets other `e_flags` bits based on the target.
I had to bump the object crate version since some of these constants were [added
recently](https://github.com/gimli-rs/object/pull/433). I'm not sure if this
PR needs a test, but I can confirm that it fixes the linking issue on both
targets I mentioned.
Handle mismatched generic param kinds in trait impls betterly
- Check that generic params on a generic associated type are the same as in the trait definition
- Check that const generics are not used in place of type generics (and the other way round too)
r? `@lcnr`
Check hidden types for well formedness at the definition site instead of only at the opaque type itself
work towards #90409 . We'll need to look into closure and generator bodies of closures and generators nested inside the hidden type in order to fix that. In hindsight this PR is not necessary for that, but it may be a bit easier with it and we'll get better diagnostics from it on its own.
