library/core/src/panic.rs

   1 //! Panic support in the standard library.
   2
   3 #![stable(feature = "core_panic_info", since = "1.41.0")]
   4
   5 mod location;
   6 mod panic_info;
   7 mod unwind_safe;
   8
   9 use crate::any::Any;
  10
  11 #[stable(feature = "panic_hooks", since = "1.10.0")]
  12 pub use self::location::Location;
  13 #[stable(feature = "panic_hooks", since = "1.10.0")]
  14 pub use self::panic_info::PanicInfo;
  15 #[stable(feature = "catch_unwind", since = "1.9.0")]
  16 pub use self::unwind_safe::{AssertUnwindSafe, RefUnwindSafe, UnwindSafe};
  17
  18 #[doc(hidden)]
  19 #[unstable(feature = "edition_panic", issue = "none", reason = "use panic!() instead")]
  20 #[allow_internal_unstable(core_panic, const_format_args)]
  21 #[rustc_diagnostic_item = "core_panic_2015_macro"]
  22 #[rustc_macro_transparency = "semitransparent"]
  23 pub macro panic_2015 {
  24     () => (
  25         $crate::panicking::panic("explicit panic")
  26     ),
  27     ($msg:literal $(,)?) => (
  28         $crate::panicking::panic($msg)
  29     ),
  30     // Use `panic_str` instead of `panic_display::<&str>` for non_fmt_panic lint.
  31     ($msg:expr $(,)?) => (
  32         $crate::panicking::panic_str($msg)
  33     ),
  34     // Special-case the single-argument case for const_panic.
  35     ("{}", $arg:expr $(,)?) => (
  36         $crate::panicking::panic_display(&$arg)
  37     ),
  38     ($fmt:expr, $($arg:tt)+) => (
  39         $crate::panicking::panic_fmt($crate::const_format_args!($fmt, $($arg)+))
  40     ),
  41 }
  42
  43 #[doc(hidden)]
  44 #[unstable(feature = "edition_panic", issue = "none", reason = "use panic!() instead")]
  45 #[allow_internal_unstable(core_panic, const_format_args)]
  46 #[rustc_diagnostic_item = "core_panic_2021_macro"]
  47 #[rustc_macro_transparency = "semitransparent"]
  48 pub macro panic_2021 {
  49     () => (
  50         $crate::panicking::panic("explicit panic")
  51     ),
  52     // Special-case the single-argument case for const_panic.
  53     ("{}", $arg:expr $(,)?) => (
  54         $crate::panicking::panic_display(&$arg)
  55     ),
  56     ($($t:tt)+) => (
  57         $crate::panicking::panic_fmt($crate::const_format_args!($($t)+))
  58     ),
  59 }
  60
  61 #[doc(hidden)]
  62 #[unstable(feature = "edition_panic", issue = "none", reason = "use unreachable!() instead")]
  63 #[allow_internal_unstable(core_panic)]
  64 #[rustc_diagnostic_item = "unreachable_2015_macro"]
  65 #[rustc_macro_transparency = "semitransparent"]
  66 pub macro unreachable_2015 {
  67     () => (
  68         $crate::panicking::panic("internal error: entered unreachable code")
  69     ),
  70     // Use of `unreachable_display` for non_fmt_panic lint.
  71     // NOTE: the message ("internal error ...") is embedded directly in unreachable_display
  72     ($msg:expr $(,)?) => (
  73         $crate::panicking::unreachable_display(&$msg)
  74     ),
  75     ($fmt:expr, $($arg:tt)*) => (
  76         $crate::panic!($crate::concat!("internal error: entered unreachable code: ", $fmt), $($arg)*)
  77     ),
  78 }
  79
  80 #[doc(hidden)]
  81 #[unstable(feature = "edition_panic", issue = "none", reason = "use unreachable!() instead")]
  82 #[allow_internal_unstable(core_panic)]
  83 #[rustc_macro_transparency = "semitransparent"]
  84 pub macro unreachable_2021 {
  85     () => (
  86         $crate::panicking::panic("internal error: entered unreachable code")
  87     ),
  88     ($($t:tt)+) => (
  89         $crate::panic!("internal error: entered unreachable code: {}", $crate::format_args!($($t)+))
  90     ),
  91 }
  92
  93 /// An internal trait used by libstd to pass data from libstd to `panic_unwind`
  94 /// and other panic runtimes. Not intended to be stabilized any time soon, do
  95 /// not use.
  96 #[unstable(feature = "std_internals", issue = "none")]
  97 #[doc(hidden)]
  98 pub unsafe trait BoxMeUp {
  99     /// Take full ownership of the contents.
 100     /// The return type is actually `Box<dyn Any + Send>`, but we cannot use `Box` in libcore.
 101     ///
 102     /// After this method got called, only some dummy default value is left in `self`.
 103     /// Calling this method twice, or calling `get` after calling this method, is an error.
 104     ///
 105     /// The argument is borrowed because the panic runtime (`__rust_start_panic`) only
 106     /// gets a borrowed `dyn BoxMeUp`.
 107     fn take_box(&mut self) -> *mut (dyn Any + Send);
 108
 109     /// Just borrow the contents.
 110     fn get(&mut self) -> &(dyn Any + Send);
 111 }