Taking a raw ref (`&raw (const|mut)`) of a deref of pointer (`*ptr`) is always safe
T-opsem decided in https://github.com/rust-lang/reference/pull/1387 that `*ptr` is only unsafe if the place is accessed. This means that taking a raw ref of a deref expr is always safe, since it doesn't constitute a read.
This also relaxes the `DEREF_NULLPTR` lint to stop warning in the case of raw ref of a deref'd nullptr, and updates its docs to reflect that change in the UB specification.
This does not change the behavior of `addr_of!((*ptr).field)`, since field projections still require the projection is in-bounds.
I'm on the fence whether this requires an FCP, since it's something that is guaranteed by the reference you could ostensibly call this a bugfix since we were counting truly safe operations as unsafe. Perhaps someone on opsem has a strong opinion? cc `@rust-lang/opsem`
Currently, not all libcs have the `posix_spawn_file_actions_addchdir_np` symbol
available to them. So we attempt to do a weak symbol lookup for that function.
But that only works if libc is a dynamic library -- with statically linked musl
binaries the symbol lookup would never work, so we would never be able to use it
even if the musl in use supported the symbol.
Now that Rust has a minimum musl version of 1.2.3, all supported musl versions
now include this symbol, so we can unconditionally expect it to be there. This
symbol was added to libc in https://github.com/rust-lang/libc/pull/3949 -- use
it here.
I couldn't find any tests for whether the posix_spawn path is used, but I've
verified with cargo-nextest that this change works. This is a substantial
improvement to nextest's performance with musl. On my workstation with a Ryzen
7950x, against https://github.com/clap-rs/clap at
61f5ee514f8f60ed8f04c6494bdf36c19e7a8126:
Before:
```
Summary [ 1.071s] 879 tests run: 879 passed, 0 skipped
```
After:
```
Summary [ 0.392s] 879 tests run: 879 passed, 0 skipped
```
Fixes#99740.
HashStable for rustc_feature::Features: stop hashing compile-time constant
It seems like back in 542bc75dea this was added as "hash the boolean value of each lang feature", but then in 1487bd6a17 this got split into first hashing a sequence of `bool`s (representing all the features) and then hashing all the feature names... but the list of feature names is a compile-time constant, so it seems entirely unnecessary to hash them?
Cc `@Mark-Simulacrum` who wrote the second of the commits mentioned above.
Cc `@nnethercote`
coverage: Pass coverage mappings to LLVM as separate structs
Instead of trying to cram *N* different kinds of coverage mapping data into a single list for FFI, pass *N* different lists of simpler structs.
This avoids the need to fill unused fields with dummy values, and avoids the need to tag structs with their underlying kind. It also lets us call the dedicated LLVM constructors for each different mapping type, instead of having to go through the complex general-purpose constructor.
Even though this adds multiple new structs to the FFI surface area, the resulting C++ code is simpler and shorter.
---
I've structured this mostly as a single atomic patch, rather than a series of incremental changes, because that avoids the need to make fiddly fixes to code that is about to be deleted anyway.
Don't allow test revisions that conflict with built in cfgs
Fixes#128964
Sorry `@heysujal` I started working on this about 1 minute before your comment by complete coincidence 😅
minor `*dyn` cast cleanup
Small follow-up to https://github.com/rust-lang/rust/pull/130234 to remove a redundant check and clean up comments. No functional changes.
Also, explain why casts cannot drop the principal even though coercions can, and add a test because apparently we didn't have one already.
r? `@WaffleLapkin` or `@compiler-errors`
Deeply normalize `TypeTrace` when reporting type error in new solver
Normalize the values that come from the `TypeTrace` for various type mismatches.
Side-note: We can't normalize the `TypeError` itself bc it may come from instantiated binders, so it may reference values from within the probe...
r? lcnr
Fix `target_vendor` in QNX Neutrino targets
The `x86_64-pc-nto-qnx710` and `i586-pc-nto-qnx700` targets have `pc` in their target triple names, but the vendor was set to the default `"unknown"`.
CC target maintainers `@flba-eb,` `@gh-tr,` `@jonathanpallant` and `@japaric`
Rename Receiver -> LegacyReceiver
As part of the "arbitrary self types v2" project, we are going to replace the current `Receiver` trait with a new mechanism based on a new, different `Receiver` trait.
This PR renames the old trait to get it out the way. Naming is hard. Options considered included:
* HardCodedReceiver (because it should only be used for things in the standard library, and hence is sort-of hard coded)
* LegacyReceiver
* TargetLessReceiver
* OldReceiver
These are all bad names, but fortunately this will be temporary. Assuming the new mechanism proceeds to stabilization as intended, the legacy trait will be removed altogether.
Although we expect this trait to be used only in the standard library, we suspect it may be in use elsehwere, so we're landing this change separately to identify any surprising breakages.
It's known that this trait is used within the Rust for Linux project; a patch is in progress to remove their dependency.
This is a part of the arbitrary self types v2 project,
https://github.com/rust-lang/rfcs/pull/3519https://github.com/rust-lang/rust/issues/44874
r? `@wesleywiser`
Rollup of 9 pull requests
Successful merges:
- #130991 (Vectorized SliceContains)
- #131928 (rustdoc: Document `markdown` module.)
- #131955 (Set `signext` or `zeroext` for integer arguments on RISC-V and LoongArch64)
- #131979 (Minor tweaks to `compare_impl_item.rs`)
- #132036 (Add a test case for #131164)
- #132039 (Specialize `read_exact` and `read_buf_exact` for `VecDeque`)
- #132060 ("innermost", "outermost", "leftmost", and "rightmost" don't need hyphens)
- #132065 (Clarify documentation of `ptr::dangling()` function)
- #132066 (Fix a typo in documentation of `pointer::sub_ptr()`)
r? `@ghost`
`@rustbot` modify labels: rollup
"innermost", "outermost", "leftmost", and "rightmost" don't need hyphens
These are all standard dictionary words and don't require hyphenation.
-----
Encountered an instance of this in error messages and it bugged me, so I
figured I'd fix it across the entire codebase.
Add a test case for #131164
The upstream has already been fixed, but it won't be backported to LLVM 19.
r? jieyouxu or compiler
try-job: x86_64-gnu-stable
Minor tweaks to `compare_impl_item.rs`
1. Stop using the `InstantiatedPredicates` struct for `hybrid_preds` in `compare_impl_item.rs`, since we never actually push anything into the `spans` part of it.
2. Remove redundant impl args and don't do useless identity substitution, prefer calling `instantiate_identity`.
Set `signext` or `zeroext` for integer arguments on RISC-V and LoongArch64
This PR contains 3 commits:
- the first one introduces a new function `adjust_for_rust_abi` in `rustc_target`, and moves the x86 specific adjustment code into it;
- the second one adds RISC-V specific adjustment code into it, which sets `signext` or `zeroext` attribute for integer arguments.
- **UPDATE**: added the 3rd commit to apply the same adjustment for LoongArch64.
rustdoc: Document `markdown` module.
Rustdoc markdown handling is currently split between:
- html::markdown, which contains all the meaty login
- markdown, which is only used for when rustdoc renders a standalone markdown file
Adds module-level doc-comment to markdown, and rename the function so it's clear that it's doing IO (instead of just rendering to a string).
CI: rfl: use rust-next temporary commit
Commit c95bbb59a9b22f9b838b15d28319185c1c884329 within rust-next contains some changes required to be compatible with upcoming arbitraty self types work. Roll RFL CI forward to the latest rust-next to include that work.
Related:
https://github.com/rust-lang/rust/pull/130225https://github.com/rust-lang/rust/issues/44874
r? ``@ojeda``
try-job: x86_64-rust-for-linux
do not remove `.cargo` directory
If vendoring isn't used bootstrap removes `.cargo` directory, which prevents developers from setting certain options in the `.cargo/config.toml` file. This was introduced in https://github.com/rust-lang/rust/pull/97513 (specifically in [this commit](345eb14f6c)). Also, since https://github.com/rust-lang/rust/pull/123942, vendoring is now possible even in git sources, which means we shouldn't remove `.cargo` directory in git sources anymore.
Add wasm32v1-none target (compiler-team/#791)
This is a preliminary implementation of the MCP discussed in [compiler-team#791](https://github.com/rust-lang/compiler-team/issues/791). It's not especially "major" but you know, process! Anyway it adds a new wasm32v1-none target which just pins down a set of wasm features. I think this is close to the consensus that emerged when discussing it on Zulip so I figured I'd sketch to see how hard it is. Turns out not very.
Compiletest: Custom differ
This adds support for a custom differ for compiletests. It’s purely visual and helps produce cleaner output when UI tests fail.
I’m using an environment variable for now since it’s experimental and I don’t want to drill the cli arguments all the way down. Also did a bit of general cleanup while I was at it.
This is how it looks [with debug info silenced](https://github.com/rust-lang/rust/pull/131182) (#131182)
`COMPILETEST_DIFF_TOOL="/usr/bin/env difft --color always --background light --display side-by-side" ./x test tests/ui/parser`
Refactor change detection for rustdoc and download-rustc
This pull request refactors the change detection logic in the build process by consolidating redundant code into a new helper method. The key changes include the removal of duplicate logic for checking changes in directories and the addition of a new method to handle this functionality.
Refactoring and code simplification:
* [`src/bootstrap/src/core/build_steps/tool.rs`](diffhunk://#diff-dc86e288bcf7b3ca3f8c127d3568fbafc785704883bc7fc336bd185910aed5daL588-R593): Removed redundant change detection logic and replaced it with a call to the new `check_for_changes` method.
* [`src/bootstrap/src/core/config/config.rs`](diffhunk://#diff-5f5330cfcdb0a89b85ac3547b761c3a45c2534a85c4aaae8fea88c711a7a65b2R2837-R2872): Added a new method `check_for_changes` to centralize the logic for detecting changes in specified directories since a given commit.
* [`src/bootstrap/src/core/config/config.rs`](diffhunk://#diff-5f5330cfcdb0a89b85ac3547b761c3a45c2534a85c4aaae8fea88c711a7a65b2L2728-R2740): Updated the existing change detection code to use the new `check_for_changes` method.
Cleanup:
* [`src/bootstrap/src/core/build_steps/tool.rs`](diffhunk://#diff-dc86e288bcf7b3ca3f8c127d3568fbafc785704883bc7fc336bd185910aed5daL13-R13): Removed the unused import `git` from the helpers module.
r? ``@AlbertLarsan68``
