100 lines
3.2 KiB
Go
100 lines
3.2 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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//go:build race
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package deephash
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import (
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"fmt"
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"net/netip"
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"reflect"
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"time"
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)
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// pointer is a typed pointer that performs safety checks for every operation.
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type pointer struct {
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unsafePointer
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t reflect.Type // type of pointed-at value; may be nil
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n uintptr // size of valid memory after p
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}
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// pointerOf returns a pointer from v, which must be a reflect.Pointer.
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func pointerOf(v reflect.Value) pointer {
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assert(v.Kind() == reflect.Pointer, "got %v, want pointer", v.Kind())
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te := v.Type().Elem()
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return pointer{unsafePointerOf(v), te, te.Size()}
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}
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func (p pointer) pointerElem() pointer {
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assert(p.t.Kind() == reflect.Pointer, "got %v, want pointer", p.t.Kind())
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te := p.t.Elem()
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return pointer{p.unsafePointer.pointerElem(), te, te.Size()}
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}
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func (p pointer) sliceLen() int {
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assert(p.t.Kind() == reflect.Slice, "got %v, want slice", p.t.Kind())
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return p.unsafePointer.sliceLen()
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}
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func (p pointer) sliceArray() pointer {
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assert(p.t.Kind() == reflect.Slice, "got %v, want slice", p.t.Kind())
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n := p.sliceLen()
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assert(n >= 0, "got negative slice length %d", n)
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ta := reflect.ArrayOf(n, p.t.Elem())
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return pointer{p.unsafePointer.sliceArray(), ta, ta.Size()}
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}
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func (p pointer) arrayIndex(index int, size uintptr) pointer {
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assert(p.t.Kind() == reflect.Array, "got %v, want array", p.t.Kind())
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assert(0 <= index && index < p.t.Len(), "got array of size %d, want to access element %d", p.t.Len(), index)
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assert(p.t.Elem().Size() == size, "got element size of %d, want %d", p.t.Elem().Size(), size)
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te := p.t.Elem()
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return pointer{p.unsafePointer.arrayIndex(index, size), te, te.Size()}
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}
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func (p pointer) structField(index int, offset, size uintptr) pointer {
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assert(p.t.Kind() == reflect.Struct, "got %v, want struct", p.t.Kind())
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assert(p.n >= offset, "got size of %d, want excessive start offset of %d", p.n, offset)
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assert(p.n >= offset+size, "got size of %d, want excessive end offset of %d", p.n, offset+size)
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if index < 0 {
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return pointer{p.unsafePointer.structField(index, offset, size), nil, size}
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}
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sf := p.t.Field(index)
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t := sf.Type
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assert(sf.Offset == offset, "got offset of %d, want offset %d", sf.Offset, offset)
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assert(t.Size() == size, "got size of %d, want size %d", t.Size(), size)
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return pointer{p.unsafePointer.structField(index, offset, size), t, t.Size()}
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}
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func (p pointer) asString() *string {
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assert(p.t.Kind() == reflect.String, "got %v, want string", p.t)
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return p.unsafePointer.asString()
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}
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func (p pointer) asTime() *time.Time {
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assert(p.t == timeTimeType, "got %v, want %v", p.t, timeTimeType)
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return p.unsafePointer.asTime()
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}
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func (p pointer) asAddr() *netip.Addr {
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assert(p.t == netipAddrType, "got %v, want %v", p.t, netipAddrType)
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return p.unsafePointer.asAddr()
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}
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func (p pointer) asValue(typ reflect.Type) reflect.Value {
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assert(p.t == typ, "got %v, want %v", p.t, typ)
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return p.unsafePointer.asValue(typ)
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}
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func (p pointer) asMemory(size uintptr) []byte {
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assert(p.n >= size, "got size of %d, want excessive size of %d", p.n, size)
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return p.unsafePointer.asMemory(size)
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}
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func assert(b bool, f string, a ...any) {
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if !b {
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panic(fmt.Sprintf(f, a...))
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}
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}
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