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Diffstat (limited to 'src/libcore/panic.rs')
| -rw-r--r-- | src/libcore/panic.rs | 361 |
1 files changed, 0 insertions, 361 deletions
diff --git a/src/libcore/panic.rs b/src/libcore/panic.rs deleted file mode 100644 index 316ecafe572..00000000000 --- a/src/libcore/panic.rs +++ /dev/null @@ -1,361 +0,0 @@ -//! Panic support in the standard library. - -#![stable(feature = "core_panic_info", since = "1.41.0")] - -use crate::any::Any; -use crate::fmt; - -/// A struct providing information about a panic. -/// -/// `PanicInfo` structure is passed to a panic hook set by the [`set_hook`] -/// function. -/// -/// [`set_hook`]: ../../std/panic/fn.set_hook.html -/// -/// # Examples -/// -/// ```should_panic -/// use std::panic; -/// -/// panic::set_hook(Box::new(|panic_info| { -/// if let Some(s) = panic_info.payload().downcast_ref::<&str>() { -/// println!("panic occurred: {:?}", s); -/// } else { -/// println!("panic occurred"); -/// } -/// })); -/// -/// panic!("Normal panic"); -/// ``` -#[lang = "panic_info"] -#[stable(feature = "panic_hooks", since = "1.10.0")] -#[derive(Debug)] -pub struct PanicInfo<'a> { - payload: &'a (dyn Any + Send), - message: Option<&'a fmt::Arguments<'a>>, - location: &'a Location<'a>, -} - -impl<'a> PanicInfo<'a> { - #[unstable( - feature = "panic_internals", - reason = "internal details of the implementation of the `panic!` and related macros", - issue = "none" - )] - #[doc(hidden)] - #[inline] - pub fn internal_constructor( - message: Option<&'a fmt::Arguments<'a>>, - location: &'a Location<'a>, - ) -> Self { - struct NoPayload; - PanicInfo { location, message, payload: &NoPayload } - } - - #[unstable( - feature = "panic_internals", - reason = "internal details of the implementation of the `panic!` and related macros", - issue = "none" - )] - #[doc(hidden)] - #[inline] - pub fn set_payload(&mut self, info: &'a (dyn Any + Send)) { - self.payload = info; - } - - /// Returns the payload associated with the panic. - /// - /// This will commonly, but not always, be a `&'static str` or [`String`]. - /// - /// [`String`]: ../../std/string/struct.String.html - /// - /// # Examples - /// - /// ```should_panic - /// use std::panic; - /// - /// panic::set_hook(Box::new(|panic_info| { - /// if let Some(s) = panic_info.payload().downcast_ref::<&str>() { - /// println!("panic occurred: {:?}", s); - /// } else { - /// println!("panic occurred"); - /// } - /// })); - /// - /// panic!("Normal panic"); - /// ``` - #[stable(feature = "panic_hooks", since = "1.10.0")] - pub fn payload(&self) -> &(dyn Any + Send) { - self.payload - } - - /// If the `panic!` macro from the `core` crate (not from `std`) - /// was used with a formatting string and some additional arguments, - /// returns that message ready to be used for example with [`fmt::write`] - /// - /// [`fmt::write`]: ../fmt/fn.write.html - #[unstable(feature = "panic_info_message", issue = "66745")] - pub fn message(&self) -> Option<&fmt::Arguments<'_>> { - self.message - } - - /// Returns information about the location from which the panic originated, - /// if available. - /// - /// This method will currently always return [`Some`], but this may change - /// in future versions. - /// - /// [`Some`]: ../../std/option/enum.Option.html#variant.Some - /// - /// # Examples - /// - /// ```should_panic - /// use std::panic; - /// - /// panic::set_hook(Box::new(|panic_info| { - /// if let Some(location) = panic_info.location() { - /// println!("panic occurred in file '{}' at line {}", - /// location.file(), - /// location.line(), - /// ); - /// } else { - /// println!("panic occurred but can't get location information..."); - /// } - /// })); - /// - /// panic!("Normal panic"); - /// ``` - #[stable(feature = "panic_hooks", since = "1.10.0")] - pub fn location(&self) -> Option<&Location<'_>> { - // NOTE: If this is changed to sometimes return None, - // deal with that case in std::panicking::default_hook and std::panicking::begin_panic_fmt. - Some(&self.location) - } -} - -#[stable(feature = "panic_hook_display", since = "1.26.0")] -impl fmt::Display for PanicInfo<'_> { - fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { - formatter.write_str("panicked at ")?; - if let Some(message) = self.message { - write!(formatter, "'{}', ", message)? - } else if let Some(payload) = self.payload.downcast_ref::<&'static str>() { - write!(formatter, "'{}', ", payload)? - } - // NOTE: we cannot use downcast_ref::<String>() here - // since String is not available in libcore! - // The payload is a String when `std::panic!` is called with multiple arguments, - // but in that case the message is also available. - - self.location.fmt(formatter) - } -} - -/// A struct containing information about the location of a panic. -/// -/// This structure is created by the [`location`] method of [`PanicInfo`]. -/// -/// [`location`]: ../../std/panic/struct.PanicInfo.html#method.location -/// [`PanicInfo`]: ../../std/panic/struct.PanicInfo.html -/// -/// # Examples -/// -/// ```should_panic -/// use std::panic; -/// -/// panic::set_hook(Box::new(|panic_info| { -/// if let Some(location) = panic_info.location() { -/// println!("panic occurred in file '{}' at line {}", location.file(), location.line()); -/// } else { -/// println!("panic occurred but can't get location information..."); -/// } -/// })); -/// -/// panic!("Normal panic"); -/// ``` -/// -/// # Comparisons -/// -/// Comparisons for equality and ordering are made in file, line, then column priority. -/// Files are compared as strings, not `Path`, which could be unexpected. -/// See [`Location::file`]'s documentation for more discussion. -#[lang = "panic_location"] -#[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)] -#[stable(feature = "panic_hooks", since = "1.10.0")] -pub struct Location<'a> { - file: &'a str, - line: u32, - col: u32, -} - -impl<'a> Location<'a> { - /// Returns the source location of the caller of this function. If that function's caller is - /// annotated then its call location will be returned, and so on up the stack to the first call - /// within a non-tracked function body. - /// - /// # Examples - /// - /// ``` - /// use core::panic::Location; - /// - /// /// Returns the [`Location`] at which it is called. - /// #[track_caller] - /// fn get_caller_location() -> &'static Location<'static> { - /// Location::caller() - /// } - /// - /// /// Returns a [`Location`] from within this function's definition. - /// fn get_just_one_location() -> &'static Location<'static> { - /// get_caller_location() - /// } - /// - /// let fixed_location = get_just_one_location(); - /// assert_eq!(fixed_location.file(), file!()); - /// assert_eq!(fixed_location.line(), 14); - /// assert_eq!(fixed_location.column(), 5); - /// - /// // running the same untracked function in a different location gives us the same result - /// let second_fixed_location = get_just_one_location(); - /// assert_eq!(fixed_location.file(), second_fixed_location.file()); - /// assert_eq!(fixed_location.line(), second_fixed_location.line()); - /// assert_eq!(fixed_location.column(), second_fixed_location.column()); - /// - /// let this_location = get_caller_location(); - /// assert_eq!(this_location.file(), file!()); - /// assert_eq!(this_location.line(), 28); - /// assert_eq!(this_location.column(), 21); - /// - /// // running the tracked function in a different location produces a different value - /// let another_location = get_caller_location(); - /// assert_eq!(this_location.file(), another_location.file()); - /// assert_ne!(this_location.line(), another_location.line()); - /// assert_ne!(this_location.column(), another_location.column()); - /// ``` - #[stable(feature = "track_caller", since = "1.46.0")] - #[rustc_const_unstable(feature = "const_caller_location", issue = "47809")] - #[track_caller] - pub const fn caller() -> &'static Location<'static> { - crate::intrinsics::caller_location() - } -} - -impl<'a> Location<'a> { - #![unstable( - feature = "panic_internals", - reason = "internal details of the implementation of the `panic!` and related macros", - issue = "none" - )] - #[doc(hidden)] - pub const fn internal_constructor(file: &'a str, line: u32, col: u32) -> Self { - Location { file, line, col } - } - - /// Returns the name of the source file from which the panic originated. - /// - /// # `&str`, not `&Path` - /// - /// The returned name refers to a source path on the compiling system, but it isn't valid to - /// represent this directly as a `&Path`. The compiled code may run on a different system with - /// a different `Path` implementation than the system providing the contents and this library - /// does not currently have a different "host path" type. - /// - /// The most surprising behavior occurs when "the same" file is reachable via multiple paths in - /// the module system (usually using the `#[path = "..."]` attribute or similar), which can - /// cause what appears to be identical code to return differing values from this function. - /// - /// # Cross-compilation - /// - /// This value is not suitable for passing to `Path::new` or similar constructors when the host - /// platform and target platform differ. - /// - /// # Examples - /// - /// ```should_panic - /// use std::panic; - /// - /// panic::set_hook(Box::new(|panic_info| { - /// if let Some(location) = panic_info.location() { - /// println!("panic occurred in file '{}'", location.file()); - /// } else { - /// println!("panic occurred but can't get location information..."); - /// } - /// })); - /// - /// panic!("Normal panic"); - /// ``` - #[stable(feature = "panic_hooks", since = "1.10.0")] - pub fn file(&self) -> &str { - self.file - } - - /// Returns the line number from which the panic originated. - /// - /// # Examples - /// - /// ```should_panic - /// use std::panic; - /// - /// panic::set_hook(Box::new(|panic_info| { - /// if let Some(location) = panic_info.location() { - /// println!("panic occurred at line {}", location.line()); - /// } else { - /// println!("panic occurred but can't get location information..."); - /// } - /// })); - /// - /// panic!("Normal panic"); - /// ``` - #[stable(feature = "panic_hooks", since = "1.10.0")] - pub fn line(&self) -> u32 { - self.line - } - - /// Returns the column from which the panic originated. - /// - /// # Examples - /// - /// ```should_panic - /// use std::panic; - /// - /// panic::set_hook(Box::new(|panic_info| { - /// if let Some(location) = panic_info.location() { - /// println!("panic occurred at column {}", location.column()); - /// } else { - /// println!("panic occurred but can't get location information..."); - /// } - /// })); - /// - /// panic!("Normal panic"); - /// ``` - #[stable(feature = "panic_col", since = "1.25.0")] - pub fn column(&self) -> u32 { - self.col - } -} - -#[stable(feature = "panic_hook_display", since = "1.26.0")] -impl fmt::Display for Location<'_> { - fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result { - write!(formatter, "{}:{}:{}", self.file, self.line, self.col) - } -} - -/// An internal trait used by libstd to pass data from libstd to `panic_unwind` -/// and other panic runtimes. Not intended to be stabilized any time soon, do -/// not use. -#[unstable(feature = "std_internals", issue = "none")] -#[doc(hidden)] -pub unsafe trait BoxMeUp { - /// Take full ownership of the contents. - /// The return type is actually `Box<dyn Any + Send>`, but we cannot use `Box` in libcore. - /// - /// After this method got called, only some dummy default value is left in `self`. - /// Calling this method twice, or calling `get` after calling this method, is an error. - /// - /// The argument is borrowed because the panic runtime (`__rust_start_panic`) only - /// gets a borrowed `dyn BoxMeUp`. - fn take_box(&mut self) -> *mut (dyn Any + Send); - - /// Just borrow the contents. - fn get(&mut self) -> &(dyn Any + Send); -} |