diff options
Diffstat (limited to 'src/reflect/value.go')
| -rw-r--r-- | src/reflect/value.go | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/src/reflect/value.go b/src/reflect/value.go index c6f24a5609..a14131e1f8 100644 --- a/src/reflect/value.go +++ b/src/reflect/value.go @@ -1553,7 +1553,11 @@ func (v Value) Set(x Value) { } x = x.assignTo("reflect.Set", v.typ, target) if x.flag&flagIndir != 0 { - typedmemmove(v.typ, v.ptr, x.ptr) + if x.ptr == unsafe.Pointer(&zeroVal[0]) { + typedmemclr(v.typ, v.ptr) + } else { + typedmemmove(v.typ, v.ptr, x.ptr) + } } else { *(*unsafe.Pointer)(v.ptr) = x.ptr } @@ -2360,11 +2364,23 @@ func Zero(typ Type) Value { t := typ.(*rtype) fl := flag(t.Kind()) if ifaceIndir(t) { - return Value{t, unsafe_New(t), fl | flagIndir} + var p unsafe.Pointer + if t.size <= maxZero { + p = unsafe.Pointer(&zeroVal[0]) + } else { + p = unsafe_New(t) + } + return Value{t, p, fl | flagIndir} } return Value{t, nil, fl} } +// must match declarations in runtime/map.go. +const maxZero = 1024 + +//go:linkname zeroVal runtime.zeroVal +var zeroVal [maxZero]byte + // New returns a Value representing a pointer to a new zero value // for the specified type. That is, the returned Value's Type is PtrTo(typ). func New(typ Type) Value { |