Errors and panics
Panic results, crash and assertion support.
Contents
| Name | Summary |
|---|---|
AssertFail | The assert failure record: PanicLowering's entry point for a failed assert. |
unwrap_failed | Crashes with a compiler-built message; the UnwrapFailed lang item. |
crash_with | Writes msg and a newline to stderr (nothing when msg is empty), then aborts. |
PanicCatch | PanicLowering's catch entry point (the PanicCatch lang item). |
PanicRaise | PanicLowering's raise entry point (the PanicRaise lang item). |
Panic | What a panic function returns (PANIC.md §1.1): Ok with the declared return type, else one Err per type in the function's panic set. |
AssertFail
struct AssertFailThe assert failure record: PanicLowering's entry point for a failed assert.
Compiler-facing lang item; user code does not name it. The file is assert_fail.k because
assert is a keyword.
unwrap_failed
fn unwrap_failed(msg: *const u8, len: usize) -> !Crashes with a compiler-built message; the UnwrapFailed lang item.
Called for unwrap! on null, a checked as into a closed enum that misses, a script global
read before its line ran, and an asserting downcast p as *D on the wrong dynamic type.
msg[0..len) is a literal the lowering built whole (the expression as written and its
file:line:col), so nothing is formatted at crash time. The runtime writes it and a newline to
stderr and aborts. -> ! makes the failing arm Never. Not a panic: no try catches it and
it is in no panic set.
Parameters
msg: Pointer tolenbytes of message.
Safety
msg must be valid for reads of len bytes (a null msg is an empty message).
crash_with
fn crash_with(msg: string = "") -> !Writes msg and a newline to stderr (nothing when msg is empty), then aborts. This is what
crash! calls.
A runtime string is fine: its data pointer and length are read once and handed to the
runtime, which writes at most KAIRO_RT_CRASH_MAX (4096) bytes of them and runs no string
method. A literal costs no allocation. -> !, so a call ends its path for the flow checks.
Not a panic.
See also
crash!
PanicCatch
struct PanicCatchPanicLowering's catch entry point (the PanicCatch lang item).
Compiler-facing; user code does not name it. Layout only: payload is an opaque pointer.
PanicRaise
struct PanicRaisePanicLowering's raise entry point (the PanicRaise lang item).
Compiler-facing; user code does not name it. Layout only: payload is an opaque pointer.
Panic
enum <T, ...E> PanicWhat a panic function returns (PANIC.md §1.1): Ok with the declared
return type, else one Err per type in the function's panic set. The
compiler forms every instance (the set is deduplicated and sorted by type
id) and lays it out itself: each tag is a type id, word 0 holds the tag
and the panic site, and the payloads start at max(8, alignof(...)).
User code does not name it (SC116E).
Panic.Ok
OkThe function returned normally; value is its declared return value.
Panic.Err
ErrThe function panicked with an error of one of the types in its panic set;
one Err case exists per type in E.
Generated from Kairo source, Apache-2.0 WITH AdditionRef-Kairo-Runtime-exception.