Clarify behavior of slice prefix/suffix operations in case of equality
Operations such as starts_with, ends_with, strip_prefix and strip_suffix can be either strict (do not consider a slice to be a prefix/suffix of itself) or not. In Rust's case, they are not strict. Add a few phrases to the documentation to clarify this.
Suggest removing superfluous semicolon when statements used as expression
Fixes#105431
- it's not a pure recursive visitor, so I guess there may be some more complex scenarios not covered.
- moved `consider_removing_semicolon` to `compiler/rustc_infer` for reusing this helper function.
Handle stashing of delayed bugs
By just emitting them immediately, because it does happen in practice, when errors are downgraded to delayed bugs.
We already had one case in `lint.rs` where we handled this at the callsite. This commit changes things so it's handled within `stash_diagnostic` instead, because #121812 identified a second case, and it's possible there are more.
Fixes#121812.
r? ````@oli-obk````
Make the success arms of `if lhs || rhs` meet up in a separate block
Extracted from #118305, where this is necessary to avoid introducing a bug when injecting marker statements into the then/else arms.
---
In the previous code (#111752), the success block of `lhs` would jump directly to the success block of `rhs`. However, `rhs_success_block` could already contain statements that are specific to the RHS, and the direct goto causes them to be executed in the LHS success path as well.
This patch therefore creates a fresh block that the LHS and RHS success blocks can both jump to.
---
I think the reason we currently get away with this is that `rhs_success_block` usually doesn't contain anything other than StorageDead statements for locals used by the RHS, and those statements don't seem to cause problems in the LHS success path (which never makes those locals live).
But if we start adding meaningful statements for branch coverage (or MC/DC coverage), it's important to keep the LHS and RHS blocks separate.
make unused_imports less assertive in test modules
closes#121502
This is a fairly small change and I used the fix suggested in the example expected error message.
Not sure if I should've rather used the alternatives but this one seems the most descriptive.
Some alternatives:
- if this is meant to be a test module, add `#[cfg(test)]` to the containing module
- try adding #[cfg(test)] to this test module
- consider adding #[allow(unused_imports)] if you want to silent the lint on the unused import
- consider removing the unused import
Improve error messages for generics with default parameters
Fixes#120785
Issue: Previously, all type parameters with default types were deliberately ignored to simplify error messages. For example, an error message for Box type would display `Box<T>` instead of `Box<T, _>`. But, this resulted in unclear error message when a concrete type was used instead of the default type.
Fix: This PR fixes it by checking if a concrete type is specified after a default type to display the entire type name or the simplified type name.
Introduce `run-make` V2 infrastructure, a `run_make_support` library and port over 2 tests as example
## Preface
See [issue #40713: Switch run-make tests from Makefiles to rust](https://github.com/rust-lang/rust/issues/40713) for more context.
## Basic Description of `run-make` V2
`run-make` V2 aims to eliminate the dependency on `make` and `Makefile`s for building `run-make`-style tests. Makefiles are replaced by *recipes* (`rmake.rs`). The current implementation runs `run-make` V2 tests in 3 steps:
1. We build the support library `run_make_support` which the `rmake.rs` recipes depend on as a tool lib.
2. We build the recipe `rmake.rs` and link in the support library.
3. We run the recipe to build and run the tests.
`rmake.rs` is basically a replacement for `Makefile`, and allows running arbitrary Rust code. The support library is built using cargo, and so can depend on external crates if desired.
The infrastructure implemented by this PR is very barebones, and is the minimally required infrastructure needed to build, run and pass the two example `run-make` tests ported over to the new infrastructure.
### Example `run-make` V2 test
```rs
// ignore-tidy-linelength
extern crate run_make_support;
use std::path::PathBuf;
use run_make_support::{aux_build, rustc};
fn main() {
aux_build()
.arg("--emit=metadata")
.arg("stable.rs")
.run();
let mut stable_path = PathBuf::from(env!("TMPDIR"));
stable_path.push("libstable.rmeta");
let output = rustc()
.arg("--emit=metadata")
.arg("--extern")
.arg(&format!("stable={}", &stable_path.to_string_lossy()))
.arg("main.rs")
.run();
let stderr = String::from_utf8_lossy(&output.stderr);
let version = include_str!(concat!(env!("S"), "/src/version"));
let expected_string = format!("stable since {}", version.trim());
assert!(stderr.contains(&expected_string));
}
```
## Follow Up Work
- [ ] Adjust rustc-dev-guide docs
test: enable `unpacked-lto` tests
This enables the correct `unpacked-lto` tests.
Not sure whether `.o` should be removed.
They are bitcode for linker-plugin-lto, though there might be some `.o` for `#[no_builtins]`?
Combine `Sub` and `Equate`
Combine `Sub` and `Equate` into a new relation called `TypeRelating` (that name sounds familiar...)
Tracks the difference between `Sub` and `Equate` via `ambient_variance: ty::Variance` much like the `NllTypeRelating` relation, but implemented slightly jankier because it's a more general purpose relation.
r? lcnr
Add stubs in IR and ABI for `f16` and `f128`
This is the very first step toward the changes in https://github.com/rust-lang/rust/pull/114607 and the [`f16` and `f128` RFC](https://rust-lang.github.io/rfcs/3453-f16-and-f128.html). It adds the types to `rustc_type_ir::FloatTy` and `rustc_abi::Primitive`, and just propagates those out as `unimplemented!` stubs where necessary.
These types do not parse yet so there is no feature gate, and it should be okay to use `unimplemented!`.
The next steps will probably be AST support with parsing and the feature gate.
r? `@compiler-errors`
cc `@Nilstrieb` suggested breaking the PR up in https://github.com/rust-lang/rust/pull/120645#issuecomment-1925900572
Delete architecture-specific memchr code in std::sys
Currently all architecture-specific memchr code is only used in `std::io`. Most of the actual `memchr` capacity exposed to the user through the slice API is instead implemented in `core::slice::memchr`.
Hence this commit deletes `memchr` from `std::sys[_common]` and replace calls to it by calls to `core::slice::memchr` functions. This deletes `(r)memchr` from the list of symbols linked to libc.
The interest of putting architecture specific code back in core is linked to the discussion to be had in #113654
By just emitting them immediately, because it does happen in practice,
when errors are downgraded to delayed bugs.
We already had one case in `lint.rs` where we handled this at the
callsite. This commit changes things so it's handled within
`stash_diagnostic` instead, because #121812 identified a second case,
and it's possible there are more.
Fixes#121812.
Remove doc aliases to PATH
Remove aliases for `split_paths` and `join_paths` as should have been done in <https://github.com/rust-lang/rust/pull/119748> (Bors merged the wrong commit).
allow statics pointing to mutable statics
Fixes https://github.com/rust-lang/rust/issues/120450 for good. We can even simplify our checks: no need to specifically go looking for mutable references in const, we can just reject any reference that points to something mutable.
r? `@oli-obk`
Add proper cfg to keep only one AlignmentEnum definition for different target_pointer_widths
Detected by #121752
Only one AlignmentEnum would be used with a specified target_pointer_width
Safe Transmute: Revise safety analysis
This PR migrates `BikeshedIntrinsicFrom` to a simplified safety analysis (described [here](https://github.com/rust-lang/project-safe-transmute/issues/15)) that does not rely on analyzing the visibility of types and fields.
The revised analysis treats primitive types as safe, and user-defined types as potentially carrying safety invariants. If Rust gains explicit (un)safe fields, this PR is structured so that it will be fairly easy to thread support for those annotations into the analysis.
Notably, this PR removes the `Context` type parameter from `BikeshedIntrinsicFrom`. Most of the files changed by this PR are just UI tests tweaked to accommodate the removed parameter.
r? `@compiler-errors`
rustc: Fix wasm64 metadata object files
It looks like LLD will detect object files being either 32 or 64-bit depending on any memory present. LLD will additionally reject 32-bit objects during a 64-bit link. Previously metadata objects did not have any memories in them which led LLD to conclude they were 32-bit objects which broke 64-bit targets for wasm.
This commit fixes this by ensuring that for 64-bit targets there's a memory object present to get LLD to detect it's a 64-bit target. Additionally this commit moves away from a hand-crafted wasm encoder to the `wasm-encoder` crate on crates.io as the complexity grows for the generated object file.
Closes#121460
Detect empty leading where clauses on type aliases
1. commit: refactor the AST of type alias where clauses
* I could no longer bear the look of `.0.1` and `.1.0`
* Arguably moving `split` out of `TyAlias` into a substruct might not make that much sense from a semantic standpoint since it reprs an index into `TyAlias.predicates` but it's alright and it cleans up the usage sites of `TyAlias`
2. commit: fix an oversight: An empty leading where clause is still a leading where clause
* semantically reject empty leading where clauses on lazy type aliases
* e.g., on `#![feature(lazy_type_alias)] type X where = ();`
* make empty leading where clauses on assoc types trigger lint `deprecated_where_clause_location`
* e.g., `impl Trait for () { type X where = (); }`
