X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=library%2Fstd%2Fsrc%2Fprocess.rs;h=771461a59089b6d7b3e91de1c1a5f31b66c26e26;hb=b04c5329e1e145fb2fb46c5a7e775638712b03aa;hp=b6edf8bca0a23641b6723812143066214e8c922d;hpb=1c8b7412d4416c32854aaa588245b735712b5931;p=rust.git diff --git a/library/std/src/process.rs b/library/std/src/process.rs index b6edf8bca0a..771461a5908 100644 --- a/library/std/src/process.rs +++ b/library/std/src/process.rs @@ -1417,6 +1417,15 @@ fn from(file: fs::File) -> Stdio { /// For proper error reporting of failed processes, print the value of `ExitStatus` or /// `ExitStatusError` using their implementations of [`Display`](crate::fmt::Display). /// +/// # Differences from `ExitStatus` +/// +/// `ExitCode` is intended for terminating the currently running process, via +/// the `Termination` trait, in contrast to [`ExitStatus`], which represents the +/// termination of a child process. These APIs are separate due to platform +/// compatibility differences and their expected usage; it is not generally +/// possible to exactly reproduce an ExitStatus from a child for the current +/// process after the fact. +/// /// [`status`]: Command::status /// [`wait`]: Child::wait // @@ -1649,8 +1658,16 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { #[unstable(feature = "exit_status_error", issue = "84908")] impl crate::error::Error for ExitStatusError {} -/// This type represents the status code a process can return to its -/// parent under normal termination. +/// This type represents the status code the current process can return +/// to its parent under normal termination. +/// +/// `ExitCode` is intended to be consumed only by the standard library (via +/// [`Termination::report()`]), and intentionally does not provide accessors like +/// `PartialEq`, `Eq`, or `Hash`. Instead the standard library provides the +/// canonical `SUCCESS` and `FAILURE` exit codes as well as `From for +/// ExitCode` for constructing other arbitrary exit codes. +/// +/// # Portability /// /// Numeric values used in this type don't have portable meanings, and /// different platforms may mask different amounts of them. @@ -1661,52 +1678,78 @@ impl crate::error::Error for ExitStatusError {} /// [`SUCCESS`]: ExitCode::SUCCESS /// [`FAILURE`]: ExitCode::FAILURE /// -/// **Warning**: While various forms of this were discussed in [RFC #1937], -/// it was ultimately cut from that RFC, and thus this type is more subject -/// to change even than the usual unstable item churn. +/// # Differences from `ExitStatus` +/// +/// `ExitCode` is intended for terminating the currently running process, via +/// the `Termination` trait, in contrast to [`ExitStatus`], which represents the +/// termination of a child process. These APIs are separate due to platform +/// compatibility differences and their expected usage; it is not generally +/// possible to exactly reproduce an ExitStatus from a child for the current +/// process after the fact. +/// +/// # Examples +/// +/// `ExitCode` can be returned from the `main` function of a crate, as it implements +/// [`Termination`]: +/// +/// ``` +/// use std::process::ExitCode; +/// # fn check_foo() -> bool { true } /// -/// [RFC #1937]: https://github.com/rust-lang/rfcs/pull/1937 +/// fn main() -> ExitCode { +/// if !check_foo() { +/// return ExitCode::from(42); +/// } +/// +/// ExitCode::SUCCESS +/// } +/// ``` #[derive(Clone, Copy, Debug)] -#[unstable(feature = "process_exitcode_placeholder", issue = "48711")] +#[stable(feature = "process_exitcode", since = "1.61.0")] pub struct ExitCode(imp::ExitCode); -#[unstable(feature = "process_exitcode_placeholder", issue = "48711")] +#[stable(feature = "process_exitcode", since = "1.61.0")] impl ExitCode { - /// The canonical ExitCode for successful termination on this platform. + /// The canonical `ExitCode` for successful termination on this platform. /// /// Note that a `()`-returning `main` implicitly results in a successful /// termination, so there's no need to return this from `main` unless /// you're also returning other possible codes. - #[unstable(feature = "process_exitcode_placeholder", issue = "48711")] + #[stable(feature = "process_exitcode", since = "1.61.0")] pub const SUCCESS: ExitCode = ExitCode(imp::ExitCode::SUCCESS); - /// The canonical ExitCode for unsuccessful termination on this platform. + /// The canonical `ExitCode` for unsuccessful termination on this platform. /// /// If you're only returning this and `SUCCESS` from `main`, consider /// instead returning `Err(_)` and `Ok(())` respectively, which will /// return the same codes (but will also `eprintln!` the error). - #[unstable(feature = "process_exitcode_placeholder", issue = "48711")] + #[stable(feature = "process_exitcode", since = "1.61.0")] pub const FAILURE: ExitCode = ExitCode(imp::ExitCode::FAILURE); } impl ExitCode { - // This should not be stabilized when stabilizing ExitCode, we don't know that i32 will serve + // This is private/perma-unstable because ExitCode is opaque; we don't know that i32 will serve // all usecases, for example windows seems to use u32, unix uses the 8-15th bits of an i32, we // likely want to isolate users anything that could restrict the platform specific // representation of an ExitCode // // More info: https://internals.rust-lang.org/t/mini-pre-rfc-redesigning-process-exitstatus/5426 - /// Convert an ExitCode into an i32 - #[unstable(feature = "process_exitcode_placeholder", issue = "48711")] + /// Convert an `ExitCode` into an i32 + #[unstable( + feature = "process_exitcode_internals", + reason = "exposed only for libstd", + issue = "none" + )] #[inline] + #[doc(hidden)] pub fn to_i32(self) -> i32 { self.0.as_i32() } } -#[unstable(feature = "process_exitcode_placeholder", issue = "48711")] +#[stable(feature = "process_exitcode", since = "1.61.0")] impl From for ExitCode { - /// Construct an exit code from an arbitrary u8 value. + /// Construct an `ExitCode` from an arbitrary u8 value. fn from(code: u8) -> Self { ExitCode(imp::ExitCode::from(code)) } @@ -2049,7 +2092,7 @@ pub fn id() -> u32 { /// standard library's runtime for convenience. Other runtimes are not required /// to provide similar functionality. #[cfg_attr(not(test), lang = "termination")] -#[unstable(feature = "termination_trait_lib", issue = "43301")] +#[stable(feature = "termination_trait_lib", since = "1.61.0")] #[rustc_on_unimplemented( message = "`main` has invalid return type `{Self}`", label = "`main` can only return types that implement `{Termination}`" @@ -2057,10 +2100,11 @@ pub fn id() -> u32 { pub trait Termination { /// Is called to get the representation of the value as status code. /// This status code is returned to the operating system. + #[stable(feature = "termination_trait_lib", since = "1.61.0")] fn report(self) -> ExitCode; } -#[unstable(feature = "termination_trait_lib", issue = "43301")] +#[stable(feature = "termination_trait_lib", since = "1.61.0")] impl Termination for () { #[inline] fn report(self) -> ExitCode { @@ -2068,7 +2112,7 @@ fn report(self) -> ExitCode { } } -#[unstable(feature = "termination_trait_lib", issue = "43301")] +#[stable(feature = "termination_trait_lib", since = "1.61.0")] impl Termination for Result<(), E> { fn report(self) -> ExitCode { match self { @@ -2078,14 +2122,14 @@ fn report(self) -> ExitCode { } } -#[unstable(feature = "termination_trait_lib", issue = "43301")] +#[stable(feature = "termination_trait_lib", since = "1.61.0")] impl Termination for ! { fn report(self) -> ExitCode { self } } -#[unstable(feature = "termination_trait_lib", issue = "43301")] +#[stable(feature = "termination_trait_lib", since = "1.61.0")] impl Termination for Result { fn report(self) -> ExitCode { let Err(err) = self; @@ -2094,7 +2138,7 @@ fn report(self) -> ExitCode { } } -#[unstable(feature = "termination_trait_lib", issue = "43301")] +#[stable(feature = "termination_trait_lib", since = "1.61.0")] impl Termination for Result { fn report(self) -> ExitCode { let Err(err) = self; @@ -2102,7 +2146,7 @@ fn report(self) -> ExitCode { } } -#[unstable(feature = "termination_trait_lib", issue = "43301")] +#[stable(feature = "termination_trait_lib", since = "1.61.0")] impl Termination for ExitCode { #[inline] fn report(self) -> ExitCode {