gotosocial/vendor/github.com/pelletier/go-toml/v2/internal/danger/danger.go

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package danger
import (
"fmt"
"reflect"
"unsafe"
)
const maxInt = uintptr(int(^uint(0) >> 1))
func SubsliceOffset(data []byte, subslice []byte) int {
datap := (*reflect.SliceHeader)(unsafe.Pointer(&data))
hlp := (*reflect.SliceHeader)(unsafe.Pointer(&subslice))
if hlp.Data < datap.Data {
panic(fmt.Errorf("subslice address (%d) is before data address (%d)", hlp.Data, datap.Data))
}
offset := hlp.Data - datap.Data
if offset > maxInt {
panic(fmt.Errorf("slice offset larger than int (%d)", offset))
}
intoffset := int(offset)
if intoffset > datap.Len {
panic(fmt.Errorf("slice offset (%d) is farther than data length (%d)", intoffset, datap.Len))
}
if intoffset+hlp.Len > datap.Len {
panic(fmt.Errorf("slice ends (%d+%d) is farther than data length (%d)", intoffset, hlp.Len, datap.Len))
}
return intoffset
}
func BytesRange(start []byte, end []byte) []byte {
if start == nil || end == nil {
panic("cannot call BytesRange with nil")
}
startp := (*reflect.SliceHeader)(unsafe.Pointer(&start))
endp := (*reflect.SliceHeader)(unsafe.Pointer(&end))
if startp.Data > endp.Data {
panic(fmt.Errorf("start pointer address (%d) is after end pointer address (%d)", startp.Data, endp.Data))
}
l := startp.Len
endLen := int(endp.Data-startp.Data) + endp.Len
if endLen > l {
l = endLen
}
if l > startp.Cap {
panic(fmt.Errorf("range length is larger than capacity"))
}
return start[:l]
}
func Stride(ptr unsafe.Pointer, size uintptr, offset int) unsafe.Pointer {
// TODO: replace with unsafe.Add when Go 1.17 is released
// https://github.com/golang/go/issues/40481
return unsafe.Pointer(uintptr(ptr) + uintptr(int(size)*offset))
}