tag | 8185a093c2cd6012a9ad1614df53bf75a0ff0b47 | |
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tagger | The Android Open Source Project <initial-contribution@android.com> | Mon Aug 01 11:16:03 2022 -0700 |
object | fc86cd386e462f659b6f54099f46773e22f787f9 |
Android 12.1.0 release 17
commit | fc86cd386e462f659b6f54099f46773e22f787f9 | [log] [tgz] |
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author | Xin Li <delphij@google.com> | Sat Feb 20 13:19:23 2021 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Sat Feb 20 13:19:23 2021 +0000 |
tree | 569392943172a9c10a478f649934e46de88a1c7e | |
parent | ef1241da73bec7217e3dc7b36c1aaa35f9c6fa60 [diff] | |
parent | d96cbe24fb286f9900b414280bc85ecd941b5f50 [diff] |
[automerger skipped] Mark ab/7061308 as merged in stage. am: 2be698502c -s ours am: d96cbe24fb -s ours am skip reason: Change-Id I1ddf3428bf4ef34cdf7034f2e7a48c015a825055 with SHA-1 86cbfe134d is in history Original change: undetermined MUST ONLY BE SUBMITTED BY AUTOMERGER Change-Id: I008b78458a333b8a7db63218afff2f38d98f3269
This crate provides an attribute macro to check at compile time that the variants of an enum or the arms of a match expression are written in sorted order.
[dependencies] remain = "0.2"
Place a #[remain::sorted]
attribute on enums, structs, match-expressions, or let-statements whose value is a match-expression.
Alternatively, import as use remain::sorted;
and use #[sorted]
as the attribute.
#[remain::sorted] #[derive(Debug)] pub enum Error { BlockSignal(signal::Error), CreateCrasClient(libcras::Error), CreateEventFd(sys_util::Error), CreateSignalFd(sys_util::SignalFdError), CreateSocket(io::Error), DetectImageType(qcow::Error), DeviceJail(io_jail::Error), NetDeviceNew(virtio::NetError), SpawnVcpu(io::Error), } #[remain::sorted] #[derive(Debug)] pub struct Registers { ax: u16, cx: u16, di: u16, si: u16, sp: u16, } impl Display for Error { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { use self::Error::*; #[remain::sorted] match self { BlockSignal(e) => write!(f, "failed to block signal: {}", e), CreateCrasClient(e) => write!(f, "failed to create cras client: {}", e), CreateEventFd(e) => write!(f, "failed to create eventfd: {}", e), CreateSignalFd(e) => write!(f, "failed to create signalfd: {}", e), CreateSocket(e) => write!(f, "failed to create socket: {}", e), DetectImageType(e) => write!(f, "failed to detect disk image type: {}", e), DeviceJail(e) => write!(f, "failed to jail device: {}", e), NetDeviceNew(e) => write!(f, "failed to set up virtio networking: {}", e), SpawnVcpu(e) => write!(f, "failed to spawn VCPU thread: {}", e), } } }
If an enum variant, struct field, or match arm is inserted out of order,
NetDeviceNew(virtio::NetError), SpawnVcpu(io::Error), + AaaUhOh(Box<dyn StdError>), }
then the macro produces a compile error.
error: AaaUhOh should sort before BlockSignal --> tests/stable.rs:49:5 | 49 | AaaUhOh(Box<dyn StdError>), | ^^^^^^^
The attribute on enums and structs is supported on any rustc version 1.31+.
Rust does not yet have stable support for user-defined attributes within a function body, so the attribute on match-expressions and let-statements requires a nightly compiler and the following two features enabled:
#![feature(proc_macro_hygiene, stmt_expr_attributes)]
As a stable alternative, this crate provides a function-level attribute called #[remain::check]
which makes match-expression and let-statement attributes work on any rustc version 1.31+. Place this attribute on any function containing #[sorted]
to make them work on a stable compiler.
impl Display for Error { #[remain::check] fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { use self::Error::*; #[sorted] match self { /* ... */ } } }