Remove unnecessary `[lints.rust]` sections.
`bootstrap` and `llvm_enzyme` are now both in the extra `check-cfg` list in bootstrap, so they doesn't need to be handled explicitly in `Cargo.toml` files.
r? ```@jieyouxu```
Improve `-Zunpretty=hir` for parsed attrs
0. Rename `print_something` to `should_render` to make it distinct from `print_attribute` in that it doesn't print anything, it's just a way to probe if a type renders anything.
1. Fixes a few bugs in the `PrintAttribute` derive. Namely, the `__printed_anything` variable was entangled with the `should_render` call, leading us to always render field names but never render commas.
2. Remove the outermost `""` from the attr.
3. Debug print `Symbol`s. I know that this is redundant for some parsed attributes, but there's no good way to distinguish symbols that are ident-like and symbols which are cooked string literals. We could perhaps *conditionally* to fall back to a debug printing if the symbol doesn't match an ident? But seems like overkill.
Based on #138060, only review the commits not in that one.
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).
`bootstrap` and `llvm_enzyme` are now both in the extra `check-cfg` list
in bootstrap, so they doesn't need to be handled explicitly in
`Cargo.toml` files.
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 48caf81484, reversing changes made to c6662879b2.
cc `@RalfJung`
r? `@nnethercote` (sorry, I didn't consider this being a thing 💀)
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).
This breakage was reported in
<https://github.com/rust-lang/rust/issues/138304>.
This reverts commit 48caf81484, reversing
changes made to c6662879b2.
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
Apply dllimport in ThinLTO
This partially reverts https://github.com/rust-lang/rust/pull/103353 by properly applying `dllimport` if `-Z dylib-lto` is passed. That PR should probably fully be reverted as it looks quite sketchy. We don't know locally if the entire crate graph would be statically linked.
This should hopefully be sufficient to make ThinLTO work for rustc on Windows.
r? ``@wesleywiser``
---
Edit: This PR is changed to just generally revert https://github.com/rust-lang/rust/pull/103353.
Rollup of 12 pull requests
Successful merges:
- #136127 (Allow `*const W<dyn A> -> *const dyn A` ptr cast)
- #136968 (Turn order dependent trait objects future incompat warning into a hard error)
- #137319 (Stabilize `const_vec_string_slice`)
- #137885 (tidy: add triagebot checks)
- #138040 (compiler: Use `size_of` from the prelude instead of imported)
- #138084 (Use workspace lints for crates in `compiler/`)
- #138158 (Move more layouting logic to `rustc_abi`)
- #138160 (depend more on attr_data_structures and move find_attr! there)
- #138192 (crashes: couple more tests)
- #138216 (bootstrap: Fix stack printing when a step cycle is detected)
- #138232 (Reduce verbosity of GCC build log)
- #138242 (Revert "Don't test new error messages with the stage 0 compiler")
r? `@ghost`
`@rustbot` modify labels: rollup
depend more on attr_data_structures and move find_attr! there
r? ``@oli-obk``
This should be an easy one. It just moves some imports around. This is necessary for other changes that I'm working on not to have import cycles. However, it's an easy one to just merge on its own.
Move more layouting logic to `rustc_abi`
Move all `LayoutData`-constructing code to `rustc_abi`:
- Infaillible operations get a new `LayoutData` constructor method;
- Faillible ones get a new method on `LayoutCalculator`.
compiler: Use `size_of` from the prelude instead of imported
Use `std::mem::{size_of, size_of_val, align_of, align_of_val}` from the prelude instead of importing or qualifying them. Apply this change across the compiler.
These functions were added to all preludes in Rust 1.80.
r? ``@compiler-errors``
Change TaskDeps to start preallocated with 128 capacity
This is a tiny change that makes `TaskDeps::read_set` start preallocated with capacity for 128 elements.
From local profiling, it looks like `TaskDeps::read_set` is one of the most-often resized hash-sets in `rustc`.
Don't re-`assume` in `transmute`s that don't change niches
I noticed in nightly 2025-02-21 that `transmute` is emitting way more `assume`s than necessary for newtypes.
For example, the three transmutes in <https://rust.godbolt.org/z/fW1KaTc4o> emits
```rust
define noundef range(i32 1, 0) i32 `@repeatedly_transparent_transmute(i32` noundef range(i32 1, 0) %_1) unnamed_addr {
start:
%0 = sub i32 %_1, 1
%1 = icmp ule i32 %0, -2
call void `@llvm.assume(i1` %1)
%2 = sub i32 %_1, 1
%3 = icmp ule i32 %2, -2
call void `@llvm.assume(i1` %3)
%4 = sub i32 %_1, 1
%5 = icmp ule i32 %4, -2
call void `@llvm.assume(i1` %5)
%6 = sub i32 %_1, 1
%7 = icmp ule i32 %6, -2
call void `@llvm.assume(i1` %7)
%8 = sub i32 %_1, 1
%9 = icmp ule i32 %8, -2
call void `@llvm.assume(i1` %9)
%10 = sub i32 %_1, 1
%11 = icmp ule i32 %10, -2
call void `@llvm.assume(i1` %11)
ret i32 %_1
}
```
But those are all just newtypes that don't change size or niches, so none of it's needed.
After this PR it's down to just
```rust
define noundef range(i32 1, 0) i32 `@repeatedly_transparent_transmute(i32` noundef range(i32 1, 0) %_1) unnamed_addr {
start:
ret i32 %_1
}
```
because none of those `assume`s in the original actually did anything.
(Transmuting to something with a difference niche, though, still has the assumes -- the other tests continue to pass checking that.)
Don't include global asm in `mir_keys`, fix error body synthesis
r? oli-obk
Fixes#137470Fixes#137471Fixes#137472Fixes#137473
try-job: test-various
try-job: x86_64-apple-2
this prevents us from trying unsizing coercion in cases like
`*const W<dyn T>` -> `*const dyn T`, where it would later cause a
compilation error since `W<dyn T>: Sized` and `W<dyn T>: T` do not hold.
