go/src/runtime/checkptr.go

func checkptrAlignment(p unsafe.Pointer, elem *_type, n uintptr) { … }

// checkptrStraddles reports whether the first size-bytes of memory
// addressed by ptr is known to straddle more than one Go allocation.
func checkptrStraddles(ptr unsafe.Pointer, size uintptr) bool { … }

func checkptrArithmetic(p unsafe.Pointer, originals []unsafe.Pointer) { … }

// checkptrBase returns the base address for the allocation containing
// the address p.
//
// Importantly, if p1 and p2 point into the same variable, then
// checkptrBase(p1) == checkptrBase(p2). However, the converse/inverse
// is not necessarily true as allocations can have trailing padding,
// and multiple variables may be packed into a single allocation.
//
// checkptrBase should be an internal detail,
// but widely used packages access it using linkname.
// Notable members of the hall of shame include:
//   - github.com/bytedance/sonic
//
// Do not remove or change the type signature.
// See go.dev/issue/67401.
//
//go:linkname checkptrBase
func checkptrBase(p unsafe.Pointer) uintptr { … }