expand: Leave traces when expanding `cfg_attr` attributes
Currently `cfg_trace` just disappears during expansion, but after this PR `#[cfg_attr(some tokens)]` will leave a `#[cfg_attr_trace(some tokens)]` attribute instead of itself in AST after expansion (the new attribute is built-in and inert, its inner tokens are the same as in the original attribute).
This trace attribute can then be used by lints or other diagnostics, #133823 has some examples.
Tokens in these trace attributes are set to an empty token stream, so the traces are non-existent for proc macros and cannot affect any user-observable behavior.
This is also a weakness, because if a proc macro processes some code with the trace attributes, they will be lost, so the traces are best effort rather than precise.
The next step is to do the same thing with `cfg` attributes (`#[cfg(TRUE)]` currently remains in both AST and tokens after expanding, it should be replaced with a trace instead).
The idea belongs to `@estebank.`
Represent diagnostic side effects as dep nodes
This changes diagnostic to be tracked as a special dep node (`SideEffect`) instead of having a list of side effects associated with each dep node. `SideEffect` is always red and when forced, it emits the diagnostic and marks itself green. Each emitted diagnostic generates a new `SideEffect` with an unique dep node index.
Some implications of this:
- Diagnostic may now be emitted more than once as they can be emitted once when the `SideEffect` gets marked green and again if the task it depends on needs to be re-executed due to another node being red. It relies on deduplicating of diagnostics to avoid that.
- Anon tasks which emits diagnostics will no longer *incorrectly* be merged with other anon tasks.
- Reusing a CGU will now emit diagnostics from the task generating it.
uefi: fs: Implement exists
Also adds the initial file abstractions.
The file opening algorithm is inspired from UEFI shell. It starts by classifying if the Path is Shell mapping, text representation of device path protocol, or a relative path and converts into an absolute text representation of device path protocol.
After that, it queries all handles supporting
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL and opens the volume that matches the device path protocol prefix (similar to Windows drive). After that, it opens the file in the volume using the remaining pat.
It also introduces OwnedDevicePath and BorrowedDevicePath abstractions to allow working with the base UEFI and Shell device paths efficiently.
DevicePath in UEFI behaves like an a group of nodes laied out in the memory contiguously and thus can be modeled using iterators.
This is an effort to break the original PR (https://github.com/rust-lang/rust/pull/129700) into much smaller chunks for faster upstreaming.
Rollup of 7 pull requests
Successful merges:
- #138384 (Move `hir::Item::ident` into `hir::ItemKind`.)
- #138508 (Clarify "owned data" in E0515.md)
- #138531 (Store test diffs in job summaries and improve analysis formatting)
- #138533 (Only use `DIST_TRY_BUILD` for try jobs that were not selected explicitly)
- #138556 (Fix ICE: attempted to remap an already remapped filename)
- #138608 (rustc_target: Add target feature constraints for LoongArch)
- #138619 (Flatten `if`s in `rustc_codegen_ssa`)
r? `@ghost`
`@rustbot` modify labels: rollup
Mangle rustc_std_internal_symbols functions
This reduces the risk of issues when using a staticlib or rust dylib compiled with a different rustc version in a rust program. Currently this will either (in the case of staticlib) cause a linker error due to duplicate symbol definitions, or (in the case of rust dylibs) cause rustc_std_internal_symbols functions to be silently overridden. As rust gets more commonly used inside the implementation of libraries consumed with a C interface (like Spidermonkey, Ruby YJIT (curently has to do partial linking of all rust code to hide all symbols not part of the C api), the Rusticl OpenCL implementation in mesa) this is becoming much more of an issue. With this PR the only symbols remaining with an unmangled name are rust_eh_personality (LLVM doesn't allow renaming it) and `__rust_no_alloc_shim_is_unstable`.
Helps mitigate https://github.com/rust-lang/rust/issues/104707
try-job: aarch64-gnu-debug
try-job: aarch64-apple
try-job: x86_64-apple-1
try-job: x86_64-mingw-1
try-job: i686-mingw-1
try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: test-various
try-job: armhf-gnu
rustdoc-json: Don't also include `#[deprecated]` in `Item::attrs`
Closes#138378
Not sure if this should bump `FORMAT_VERSION` or not. CC `@Enselic` `@LukeMathWalker` `@obi1kenobi`
r? `@GuillaumeGomez,` best reviewed commit-by-commit
Install licenses into `share/doc/rust/licenses`
This changes the path from "licences" to "licenses" for consistency
across the repo, including the usage directly around this line. This is
a US/UK spelling difference, but I believe the US spelling is also more
common in open source in general.
Emit function declarations for functions with `#[linkage="extern_weak"]`
Currently, when declaring an extern weak function in Rust, we use the following syntax:
```rust
unsafe extern "C" {
#[linkage = "extern_weak"]
static FOO: Option<unsafe extern "C" fn() -> ()>;
}
```
This allows runtime-checking the extern weak symbol through the Option.
When emitting LLVM-IR, the Rust compiler currently emits this static as an i8, and a pointer that is initialized with the value of the global i8 and represents the nullabilty e.g.
```
`@FOO` = extern_weak global i8
`@_rust_extern_with_linkage_FOO` = internal global ptr `@FOO`
```
This approach does not work well with CFI, where we need to attach CFI metadata to a concrete function declaration, which was pointed out in https://github.com/rust-lang/rust/issues/115199.
This change switches to emitting a proper function declaration instead of a global i8. This allows CFI to work for extern_weak functions. Example:
```
`@_rust_extern_with_linkage_FOO` = internal global ptr `@FOO`
...
declare !type !61 !type !62 !type !63 !type !64 extern_weak void `@FOO(double)` unnamed_addr #6
```
We keep initializing the Rust internal symbol with the function declaration, which preserves the correct behavior for runtime checking the Option.
r? `@rcvalle`
cc `@jakos-sec`
try-job: test-various
mir_build: Avoid some useless work when visiting "primary" bindings
While looking over `visit_primary_bindings`, I noticed that it does a bunch of extra work to build up a collection of “user-type projections”, even though 2/3 of its call sites don't even use them. Those callers can get the same result via `thir::Pat::walk_always`.
(And it turns out that doing so also avoids creating some redundant user-type entries in MIR for some binding constructs.)
I also noticed that even when the user-type projections *are* used, the process of building them ends up eagerly cloning some nested vectors at every recursion step, even in cases where they won't be used because the current subpattern has no bindings. To avoid this, the visit method now assembles a linked list on the stack containing the information that *would* be needed to create projections, and only creates the concrete projections as needed when a primary binding is encountered.
Some relevant prior PRs:
- #55274
- 0bfe184b1a in #55937
---
There should be no user-visible change in compiler output.
Denote `ControlFlow` as `#[must_use]`
I've repeatedly hit bugs in the compiler due to `ControlFlow` not being marked `#[must_use]`. There seems to be an accepted ACP to make the type `#[must_use]` (https://github.com/rust-lang/libs-team/issues/444), so this PR implements that part of it.
Most of the usages in the compiler that trigger this new warning are "root" usages (calling into an API that uses control-flow internally, but for which the callee doesn't really care) and have been suppressed by `let _ = ...`, but I did legitimately find one instance of a missing `?` and one for a never-used `ControlFlow` value in #137448.
Presumably this needs an FCP too, so I'm opening this and nominating it for T-libs-api.
This PR also touches the tools (incl. rust-analyzer), but if this went into FCP, I'd split those out into separate PRs which can land before this one does.
r? libs-api
`@rustbot` label: T-libs-api I-libs-api-nominated
uefi: helpers: Add DevicePathNode abstractions
- UEFI device path is a series of nodes layed out in a contiguous memory region. So it makes sense to use Iterator abstraction for modeling DevicePaths
- This PR has been split off from #135368 for easier review. The allow dead_code will be removed in #135368
cc `@nicholasbishop`
Add a .bss-like scheme for encoded const allocs
This check if all bytes are zero feel like it should be too slow, and instead we should have a flag that we track, but that seems hard. Let's see how this perfs first.
Also we can probably stash the "it's all zero actually" flag inside one of the other struct members that's already not using an entire byte. This optimization doesn't fire all that often, so it's possible that by sticking it in the varint length field, this PR actually makes rmeta size worse.
Do not register `Self: AutoTrait` when confirming auto trait (in old solver)
Every built-in auto impl for a trait goal like `Ty: Auto` immediately registers another obligation of `Ty: Auto` as one of its nested obligations, leading to us stressing the cycle detection machinery a lot more than we need to. This is because all traits have a `Self: Trait` predicate.
To fix this, remove the call to `impl_or_trait_obligations` in `vtable_auto_impl`, since auto traits do not have where clauses.
r? lcnr
Calculate predecessor count directly
Avoid allocating a vector of small vectors merely to determine how many
predecessors each basic block has.
Additionally use u8 and saturating operations. The pass only needs to
distinguish between [0..1] and [2..].
Update bootstrap to edition 2024
The stage0 compiler now supports edition 2024, so we can update bootstrap to it. I manually reviewed all the changes from `cargo fix --edition` and reverted most of them (`if let` -> `matches` changes and two unneeded usages of `use <>`).
r? `@onur-ozkan`
try-job: dist-x86_64-msvc
strip `-Wlinker-messages` wrappers from `rust-lld` rmake test
The `tests/run-make/rust-lld` rmake test is failing locally on my M1, due to linker messages being in a different shape than the test expects: it asserts that the LLD version is the first linker message, which is seemingly not always the case on osx I guess.
```console
thread 'main' panicked at /Users/lqd/rust/lqd-rust/tests/run-make/rust-lld/rmake.rs:24:5:
the LLD version string should be present in the output logs:
warning: linker stderr: rust-lld: directory not found for option -L/usr/local/lib
LLD 20.1.0 (https://github.com/rust-lang/llvm-project.git 1c3bb96fdb6db7b8e8f24edb016099c223fdd27e)
Library search paths:
/Users/lqd/rust/lqd-rust/build/aarch64-apple-darwin/test/run-make/rust-lld/rmake_out
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib
Framework search paths:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks
```
This PR normalizes away the `-Wlinker-messages` wrappers around the linker output, to remove the requirement that the linker version is the first linker message / is prefixed with the warning wrapper in the regex.
(also another strange thing to explain the pre-existing regex: it seems the LLD version is sometimes output on stderr sometimes on stdout cool stuff)
We could do this for the other lld rmake tests, but they're only enabled on x64 linux so less likely to have random linker messages appearing without anyone noticing.
Allow bounds checks when enumerating `IndexSlice` to be elided
Without this hint, each loop iteration has to separately bounds check the index. See https://godbolt.org/z/zrfPY4Ten for an example.
This is technically a behaviour change, but only in cases where the compiler is going to crash anyways.
Add `#[define_opaques]` attribute and require it for all type-alias-impl-trait sites that register a hidden type
Instead of relying on the signature of items to decide whether they are constraining an opaque type, the opaque types that the item constrains must be explicitly listed.
A previous version of this PR used an actual attribute, but had to keep the resolved `DefId`s in a side table.
Now we just lower to fields in the AST that have no surface syntax, instead a builtin attribute macro fills in those fields where applicable.
Note that for convenience referencing opaque types in associated types from associated methods on the same impl will not require an attribute. If that causes problems `#[defines()]` can be used to overwrite the default of searching for opaques in the signature.
One wart of this design is that closures and static items do not have generics. So since I stored the opaques in the generics of functions, consts and methods, I would need to add a custom field to closures and statics to track this information. During a T-types discussion we decided to just not do this for now.
fixes#131298
Speed up target feature computation
The LLVM backend calls `LLVMRustHasFeature` twice for every feature. In short-running rustc invocations, this accounts for a surprising amount of work.
r? `@bjorn3`
Support for `wasm32-wali-linux-musl` Tier-3 target
Adding a new target -- `wasm32-wali-linux-musl` -- to the compiler can target the [WebAssembly Linux Interface](https://github.com/arjunr2/WALI) according to MCP rust-lang/compiler-team#797
Preliminary support involves minimal changes, primarily
* A new target spec for `wasm32_wali_linux_musl` that bridges linux options with supported wasm options. Right now, since there is no canonical Linux ABI for Wasm, we use `wali` in the vendor field, but this can be migrated in future version.
* Dependency patches to the following crates are required and these crates can be updated to bring target support:
- **stdarch** rust-lang/stdarch#1702
- **libc** rust-lang/libc#4244
- **cc** rust-lang/cc-rs#1373
* Minimal additions for FFI support
cc `@tgross35` for libc-related changes
Tier-3 policy:
> A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
I will take responsibility for maintaining this target as well as issues
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
The target name is consistent with naming patterns from currently supported targets for arch (wasm32), OS, (linux) and env (musl)
> Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
No naming confusion is introduced.
> If possible, use only letters, numbers, dashes and underscores for the name. Periods (.) are known to cause issues in Cargo.
Compliant
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
It's fully open source
> The target must not introduce license incompatibilities. Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
Noted
> The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
Compliant
> Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
All tools are open-source
> "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
No terms present
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
I am not a reviewer
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
This target supports the full standard library with appropriate configuration stubs where necessary (however, similar to all existing wasm32 targets, it excludes dynamic linking or hardware-specific features)
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
Preliminary documentation is provided at https://github.com/arjunr2/WALI. Further detailed docs (if necessary) can be added once this PR lands
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
Understood
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
To the best of my knowledge, it does not break any existing target in the ecosystem -- only minimal configuration-specific additions were made to support the target.
> Tier 3 targets must be able to produce assembly using at least one of rustc's supported backends from any host target. (Having support in a fork of the backend is not sufficient, it must be upstream.)
We can upstream LLVM target support
Reduce formatting `width` and `precision` to 16 bits
This is part of https://github.com/rust-lang/rust/issues/99012
This is reduces the `width` and `precision` fields in format strings to 16 bits. They are currently full `usize`s, but it's a bit nonsensical that we need to support the case where someone wants to pad their value to eighteen quintillion spaces and/or have eighteen quintillion digits of precision.
By reducing these fields to 16 bit, we can reduce `FormattingOptions` to 64 bits (see https://github.com/rust-lang/rust/pull/136974) and improve the in memory representation of `format_args!()`. (See additional context below.)
This also fixes a bug where the width or precision is silently truncated when cross-compiling to a target with a smaller `usize`. By reducing the width and precision fields to the minimum guaranteed size of `usize`, 16 bits, this bug is eliminated.
This is a breaking change, but affects almost no existing code.
---
Details of this change:
There are three ways to set a width or precision today:
1. Directly a formatting string, e.g. `println!("{a:1234}")`
2. Indirectly in a formatting string, e.g. `println!("{a:width$}", width=1234)`
3. Through the unstable `FormattingOptions::width` method.
This PR:
- Adds a compiler error for 1. (`println!("{a:9999999}")` no longer compiles and gives a clear error.)
- Adds a runtime check for 2. (`println!("{a:width$}, width=9999999)` will panic.)
- Changes the signatures of the (unstable) `FormattingOptions::[get_]width` methods to use a `u16` instead.
---
Additional context for improving `FormattingOptions` and `fmt::Arguments`:
All the formatting flags and options are currently:
- The `+` flag (1 bit)
- The `-` flag (1 bit)
- The `#` flag (1 bit)
- The `0` flag (1 bit)
- The `x?` flag (1 bit)
- The `X?` flag (1 bit)
- The alignment (2 bits)
- The fill character (21 bits)
- Whether a width is specified (1 bit)
- Whether a precision is specified (1 bit)
- If used, the width (a full usize)
- If used, the precision (a full usize)
Everything except the last two can simply fit in a `u32` (those add up to 31 bits in total).
If we can accept a max width and precision of u16::MAX, we can make a `FormattingOptions` that is exactly 64 bits in size; the same size as a thin reference on most platforms.
If, additionally, we also limit the number of formatting arguments, we can also reduce the size of `fmt::Arguments` (that is, of a `format_args!()` expression).
Revert "Use workspace lints for crates in `compiler/` #138084"
Revert <https://github.com/rust-lang/rust/pull/138084> to buy time to consider options that avoids breaking downstream usages of cargo on distributed `rustc-src` artifacts, where such cargo invocations fail due to inability to inherit `lints` from workspace root manifest's `workspace.lints` (this is only valid for the source rust-lang/rust workspace, but not really the distributed `rustc-src` artifacts). The problem is that the `rustc-src` component doesn't include the root `Cargo.toml` manifest.
This breakage was reported in https://github.com/rust-lang/rust/issues/138304.
This reverts commit 48caf81484b50dca5a5cebb614899a3df81ca898, reversing changes made to c6662879b27f5161e95f39395e3c9513a7b97028.
cc `@RalfJung`
r? `@nnethercote` (sorry, I didn't consider this being a thing 💀)
Fix post-merge workflow
I forgot that `actions/checkout` only checks out a single commit by default. I also forgot to set the environment variable required for the `gh` CLI commands.
I did a few more tests on my fork and hopefully now it should work properly. I also tested it with fake rollup PRs and the comment was sent only to the merged rollup, as it should be.
r? `@marcoieni`
Fix dyn -> param suggestion in struct ICEs
Makes the logic from #138042 a bit less ICEy and more clean. Also fixes an incorrect suggestion when the struct already has generics. I'll point out the major changes and observations in the code.
Fixes#138229Fixes#138211
r? nnethercote since you reviewed the original pr, or re-roll if you don't want to review this
Add a test for `-znostart-stop-gc` usage with LLD
This test replicates the behavior of https://github.com/dtolnay/linkme, to test that it still works even with LLD. Without `-znostart-stop-gc` the test fails.
r? ``@lqd``
try-job: x86_64-gnu
try-job: x86_64-msvc-1
