diff options
Diffstat (limited to 'src/runtime/panic.go')
| -rw-r--r-- | src/runtime/panic.go | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/src/runtime/panic.go b/src/runtime/panic.go index 26618db7ce..905515f822 100644 --- a/src/runtime/panic.go +++ b/src/runtime/panic.go @@ -800,8 +800,29 @@ func deferCallSave(p *_panic, fn func()) { } } +// A PanicNilError happens when code calls panic(nil). +// +// Before Go 1.21, programs that called panic(nil) observed recover returning nil. +// Starting in Go 1.21, programs that call panic(nil) observe recover returning a *PanicNilError. +// Programs can change back to the old behavior by setting GODEBUG=panicnil=1. +type PanicNilError struct { + // This field makes PanicNilError structurally different from + // any other struct in this package, and the _ makes it different + // from any struct in other packages too. + // This avoids any accidental conversions being possible + // between this struct and some other struct sharing the same fields, + // like happened in go.dev/issue/56603. + _ [0]*PanicNilError +} + +func (*PanicNilError) Error() string { return "panic called with nil argument" } +func (*PanicNilError) RuntimeError() {} + // The implementation of the predeclared function panic. func gopanic(e any) { + if e == nil && debug.panicnil.Load() != 1 { + e = new(PanicNilError) + } gp := getg() if gp.m.curg != gp { print("panic: ") |