Min specialization improvements
- Don't allow specialization impls with no items, such implementations are probably not correct and only occur as mistakes in the compiler and standard library
- Fix a missing normalization call
- Adds spans for lifetime errors from overly general specializations
Closes#79457Closes#109815
Implement builtin # syntax and use it for offset_of!(...)
Add `builtin #` syntax to the parser, as well as a generic infrastructure to support both item and expression position builtin syntaxes. The PR also uses this infrastructure for the implementation of the `offset_of!` macro, added by #106934.
cc `@petrochenkov` `@DrMeepster`
cc #110680 `builtin #` tracking issue
cc #106655 `offset_of!` tracking issue
tweak "make mut" spans when assigning to locals
Work towards fixing #106857
This PR just cleans up a lot of spans which is helpful before properly fixing the issues. Best reviewed commit-by-commit.
r? `@estebank`
Tweak borrow suggestion span
Avoids a `span_to_snippet` call when we don't need to surround the expression in parentheses. The fact that the suggestion was using the whole span of the expression rather than just appending a `&` was prevented me from using `// run-rustfix` in another PR (https://github.com/rust-lang/rust/pull/110432#discussion_r1170500484).
Also some drive-by renames of functions that have been annoying me for a bit.
Introduce `AliasKind::Inherent` for inherent associated types
Allows us to check (possibly generic) inherent associated types for well-formedness.
Type inference now also works properly.
Follow-up to #105961. Supersedes #108430.
Fixes#106722.
Fixes#108957.
Fixes#109768.
Fixes#109789.
Fixes#109790.
~Not to be merged before #108860 (`AliasKind::Weak`).~
CC `@jackh726`
r? `@compiler-errors`
`@rustbot` label T-types F-inherent_associated_types
Don't compute trait super bounds unless they're positive
Fixes#111207
The comment is modified to explain the rationale for why we even have this recursive call to supertraits in the first place, which doesn't apply to negative bounds since they don't elaborate at all.
Further normalize msvc-non-utf8-ouput
Fixes#111256 by normalizing this tests down to the essential part so that it only tests for the Unicode output we expect. Also uses a file name that should never occur outside of this test.
Fix some suggestions where a `Box<T>` is expected.
This fixes#111011, and also adds a suggestion for boxing a unit type when a `Box<T>` was expected and an empty block was found.
Fix lifetime suggestion for type aliases with objects in them
Fixes an issue identified in https://github.com/rust-lang/rust/issues/110761#issuecomment-1520678479
This suggestion, like many other borrowck suggestions, are very fragile and there are other ways to trigger strange behavior even after this PR, so this is just a small improvement and not a total rework 💀
Rename InstCombine to InstSimplify
```
╭ ➜ ben@archlinux:~/rust
╰ ➤ rg -i instcombine
src/doc/rustc-dev-guide/src/mir/optimizations.md
134:may have been misapplied. Examples of this are `InstCombine` and `ConstantPropagation`.
src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/llvm-config.sh
38: instcombine instrumentation interpreter ipo irreader lanai \
tests/codegen/slice_as_from_ptr_range.rs
4:// min-llvm-version: 15.0 (because this is a relatively new instcombine)
```
r? `@scottmcm`
Support return-type bounds on associated methods from supertraits
Support `T: Trait<method(): Bound>` when `method` comes from a supertrait, aligning it with the behavior of associated type bounds (both equality and trait bounds).
The only wrinkle is that I have to extend `super_predicates_that_define_assoc_type` to look for *all* items, not just `AssocKind::Ty`. This will also be needed to support `feature(associated_const_equality)` as well, which is subtly broken when it comes to supertraits, though this PR does not fix those yet. There's a slight chance there's a perf regression here, in which case I guess I could split it out into a separate query.
added TraitAlias to check_item() for missing_docs
As in issue #111025 the `missing_docs` was not being triggered for trait aliases. I added `TraitAlias` to the pattern match for check_item(), and the lint seems to be behaving appropriately
Operand::extract_field: only cast llval if it's a pointer and replace bitcast w/ pointercast.
Fixes#105439.
Also cc `@erikdesjardins,` looks like another place to cleanup as part of #105545
Output LLVM optimization remark kind in `-Cremark` output
Since https://github.com/rust-lang/rust/pull/90833, the optimization remark kind has not been printed. Therefore it wasn't possible to easily determine from the log (in a programmatic way) which remark kind was produced. I think that the most interesting remarks are the missed ones, which can lead users to some code optimization.
Maybe we could also change the format closer to the "old" one:
```
note: optimization remark for tailcallelim at /checkout/src/libcore/num/mod.rs:1:0: marked this call a tail call candidate
```
I wanted to programatically parse the remarks so that they could work e.g. with https://github.com/OfekShilon/optview2. However, now that I think about it, probably the proper solution is to tell rustc to output them to YAML and then use the YAML as input for the opt remark visualization tools. The flag for enabling this does not seem to work though (https://github.com/rust-lang/rust/issues/96705#issuecomment-1117632322).
Still I think that it's good to output the remark kind anyway, it's an important piece of information.
r? ```@tmiasko```
add hint for =< as <=
Adds a compiler hint for when `=<` is typed instead of `<=`
Example hint:
```rust
fn foo() {
if 1 =< 3 {
println!("Hello, World!");
}
}
```
```
error: expected type, found `3`
--> main.rs:2:13
|
2 | if 1 =< 3 {
| -- ^ expected type
| |
| help: did you mean: `<=`
```
This PR only emits the suggestion if there is no space between the `=` and `<`. This hopefully narrows the scope of when this error is emitted, however this still allows this error to be emitted in cases such as this:
```
error: expected expression, found `;`
--> main.rs:2:18
|
2 | if 1 =< [i32;; 3]>::hello() {
| -- ^ expected expression
| |
| help: did you mean: `<=`
```
Which could be a good reason not to merge since I haven't been able to think of any other ways of narrowing the scope of this diagnostic.
closes#111128
Use fulfillment to check `Drop` impl compatibility
Use an `ObligationCtxt` to ensure that a `Drop` impl does not have stricter requirements than the ADT that it's implemented for, rather than using a `SimpleEqRelation` to (more or less) syntactically equate predicates on an ADT with predicates on an impl.
r? types
### Some background
The old code reads:
```rust
// An earlier version of this code attempted to do this checking
// via the traits::fulfill machinery. However, it ran into trouble
// since the fulfill machinery merely turns outlives-predicates
// 'a:'b and T:'b into region inference constraints. It is simpler
// just to look for all the predicates directly.
```
I'm not sure what this means, but perhaps in the 8 years since that this comment was written (cc #23638) it's gotten easier to process region constraints after doing fulfillment? I don't know how this logic differs from anything we do in the `compare_impl_item` module. Ironically, later on it says:
```rust
// However, it may be more efficient in the future to batch
// the analysis together via the fulfill (see comment above regarding
// the usage of the fulfill machinery), rather than the
// repeated `.iter().any(..)` calls.
```
Also:
* Removes `SimpleEqRelation` which was far too syntactical in its relation.
* Fixes#110557
Add `force` option for `--extern` flag
When `--extern force:foo=libfoo.so` is passed to `rustc` and `foo` is not actually used in the crate, ~inject an `extern crate foo;` statement into the AST~ force it to be resolved anyway in `CrateLoader::postprocess()`. This allows you to, for instance, inject a `#[panic_handler]` implementation into a `#![no_std]` crate without modifying its source so that it can be built as a `dylib`. It may also be useful for `#![panic_runtime]` or `#[global_allocator]`/`#![default_lib_allocator]` implementations.
My work previously involved integrating Rust into an existing C/C++ codebase which was built with Buck and shipped on, among other platforms, Android. When targeting Android, Buck builds all "native" code with shared linkage* so it can be loaded from Java/Kotlin. My project was not itself `#![no_std]`, but many of our dependencies were, and they would fail to build with shared linkage due to a lack of a panic handler. With this change, that project can add the new `force` option to the `std` dependency it already explicitly provides to every crate to solve this problem.
*This is an oversimplification - Buck has a couple features for aggregating dependencies into larger shared libraries, but none that I think sustainably solve this problem.
~The AST injection happens after macro expansion around where we similarly inject a test harness and proc-macro harness. The resolver's list of actually-used extern flags is populated during macro expansion, and if any of our `--extern` arguments have the `force` option and weren't already used, we inject an `extern crate` statement for them. The injection logic was added in `rustc_builtin_macros` as that's where similar injections for tests, proc-macros, and std/core already live.~
(New contributor - grateful for feedback and guidance!)
Stabilize raw-dylib, link_ordinal, import_name_type and -Cdlltool
This stabilizes the `raw-dylib` feature (#58713) for all architectures (i.e., `x86` as it is already stable for all other architectures).
Changes:
* Permit the use of the `raw-dylib` link kind for x86, the `link_ordinal` attribute and the `import_name_type` key for the `link` attribute.
* Mark the `raw_dylib` feature as stable.
* Stabilized the `-Zdlltool` argument as `-Cdlltool`.
* Note the path to `dlltool` if invoking it failed (we don't need to do this if `dlltool` returns an error since it prints its path in the error message).
* Adds tests for `-Cdlltool`.
* Adds tests for being unable to find the dlltool executable, and dlltool failing.
* Fixes a bug where we were checking the exit code of dlltool to see if it failed, but dlltool always returns 0 (indicating success), so instead we need to check if anything was written to `stderr`.
NOTE: As previously noted (https://github.com/rust-lang/rust/pull/104218#issuecomment-1315895618) using dlltool within rustc is temporary, but this is not the first time that Rust has added a temporary tool use and argument: https://github.com/rust-lang/rust/pull/104218#issuecomment-1318720482
Big thanks to ``````@tbu-`````` for the first version of this PR (#104218)
