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https://github.com/golang/go
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reflect: implement method values
Fixes #1517. R=golang-dev, r CC=golang-dev https://golang.org/cl/7906043
This commit is contained in:
Russ Cox
parent
178d8d4f7a
commit
3be703665e
@ -1458,7 +1458,7 @@ func (p Point) AnotherMethod(scale int) int {
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// This will be index 1.
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func (p Point) Dist(scale int) int {
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// println("Point.Dist", p.x, p.y, scale)
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//println("Point.Dist", p.x, p.y, scale)
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return p.x*p.x*scale + p.y*p.y*scale
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}
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@ -1474,23 +1474,23 @@ func TestMethod(t *testing.T) {
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if !ok {
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t.Fatalf("method by name failed")
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}
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m.Func.Call([]Value{ValueOf(p), ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Type MethodByName returned %d; want 250", i)
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i = m.Func.Call([]Value{ValueOf(p), ValueOf(11)})[0].Int()
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if i != 275 {
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t.Errorf("Type MethodByName returned %d; want 275", i)
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}
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i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Pointer Type Method returned %d; want 250", i)
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i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(12)})[0].Int()
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if i != 300 {
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t.Errorf("Pointer Type Method returned %d; want 300", i)
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}
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m, ok = TypeOf(&p).MethodByName("Dist")
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if !ok {
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t.Fatalf("ptr method by name failed")
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}
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i = m.Func.Call([]Value{ValueOf(&p), ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Pointer Type MethodByName returned %d; want 250", i)
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i = m.Func.Call([]Value{ValueOf(&p), ValueOf(13)})[0].Int()
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if i != 325 {
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t.Errorf("Pointer Type MethodByName returned %d; want 325", i)
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}
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// Curried method of value.
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@ -1499,17 +1499,17 @@ func TestMethod(t *testing.T) {
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Value Method returned %d; want 250", i)
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i = v.Call([]Value{ValueOf(14)})[0].Int()
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if i != 350 {
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t.Errorf("Value Method returned %d; want 350", i)
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}
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v = ValueOf(p).MethodByName("Dist")
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Value MethodByName returned %d; want 250", i)
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i = v.Call([]Value{ValueOf(15)})[0].Int()
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if i != 375 {
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t.Errorf("Value MethodByName returned %d; want 375", i)
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}
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// Curried method of pointer.
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@ -1517,17 +1517,84 @@ func TestMethod(t *testing.T) {
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Pointer Value Method returned %d; want 250", i)
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i = v.Call([]Value{ValueOf(16)})[0].Int()
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if i != 400 {
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t.Errorf("Pointer Value Method returned %d; want 400", i)
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}
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v = ValueOf(&p).MethodByName("Dist")
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(10)})[0].Int()
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i = v.Call([]Value{ValueOf(17)})[0].Int()
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if i != 425 {
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t.Errorf("Pointer Value MethodByName returned %d; want 425", i)
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}
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// Curried method of interface value.
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// Have to wrap interface value in a struct to get at it.
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// Passing it to ValueOf directly would
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// access the underlying Point, not the interface.
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var x interface {
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Dist(int) int
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} = p
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pv := ValueOf(&x).Elem()
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v = pv.Method(0)
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(18)})[0].Int()
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if i != 450 {
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t.Errorf("Interface Method returned %d; want 450", i)
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}
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v = pv.MethodByName("Dist")
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(19)})[0].Int()
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if i != 475 {
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t.Errorf("Interface MethodByName returned %d; want 475", i)
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}
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}
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func TestMethodValue(t *testing.T) {
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p := Point{3, 4}
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var i int64
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// Curried method of value.
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tfunc := TypeOf((func(int) int)(nil))
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v := ValueOf(p).Method(1)
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
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}
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i = ValueOf(v.Interface()).Call([]Value{ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Pointer Value MethodByName returned %d; want 250", i)
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t.Errorf("Value Method returned %d; want 250", i)
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}
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v = ValueOf(p).MethodByName("Dist")
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
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}
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i = ValueOf(v.Interface()).Call([]Value{ValueOf(11)})[0].Int()
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if i != 275 {
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t.Errorf("Value MethodByName returned %d; want 275", i)
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}
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// Curried method of pointer.
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v = ValueOf(&p).Method(1)
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
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}
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i = ValueOf(v.Interface()).Call([]Value{ValueOf(12)})[0].Int()
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if i != 300 {
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t.Errorf("Pointer Value Method returned %d; want 300", i)
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}
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v = ValueOf(&p).MethodByName("Dist")
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
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}
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i = ValueOf(v.Interface()).Call([]Value{ValueOf(13)})[0].Int()
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if i != 325 {
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t.Errorf("Pointer Value MethodByName returned %d; want 325", i)
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}
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// Curried method of interface value.
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@ -1544,20 +1611,203 @@ func TestMethod(t *testing.T) {
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Interface Method returned %d; want 250", i)
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i = ValueOf(v.Interface()).Call([]Value{ValueOf(14)})[0].Int()
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if i != 350 {
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t.Errorf("Interface Method returned %d; want 350", i)
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}
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v = pv.MethodByName("Dist")
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if tt := v.Type(); tt != tfunc {
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t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
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}
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i = v.Call([]Value{ValueOf(10)})[0].Int()
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if i != 250 {
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t.Errorf("Interface MethodByName returned %d; want 250", i)
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i = ValueOf(v.Interface()).Call([]Value{ValueOf(15)})[0].Int()
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if i != 375 {
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t.Errorf("Interface MethodByName returned %d; want 375", i)
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}
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}
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// Reflect version of $GOROOT/test/method5.go
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// Concrete types implementing M method.
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// Smaller than a word, word-sized, larger than a word.
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// Value and pointer receivers.
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type Tinter interface {
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M(int, byte) (byte, int)
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}
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type Tsmallv byte
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func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x + int(v) }
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type Tsmallp byte
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func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
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type Twordv uintptr
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func (v Twordv) M(x int, b byte) (byte, int) { return b, x + int(v) }
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type Twordp uintptr
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func (p *Twordp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
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type Tbigv [2]uintptr
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func (v Tbigv) M(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) }
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type Tbigp [2]uintptr
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func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) }
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// Again, with an unexported method.
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type tsmallv byte
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func (v tsmallv) m(x int, b byte) (byte, int) { return b, x + int(v) }
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type tsmallp byte
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func (p *tsmallp) m(x int, b byte) (byte, int) { return b, x + int(*p) }
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type twordv uintptr
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func (v twordv) m(x int, b byte) (byte, int) { return b, x + int(v) }
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type twordp uintptr
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func (p *twordp) m(x int, b byte) (byte, int) { return b, x + int(*p) }
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type tbigv [2]uintptr
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func (v tbigv) m(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) }
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type tbigp [2]uintptr
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func (p *tbigp) m(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) }
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type tinter interface {
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m(int, byte) (byte, int)
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}
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// Embedding via pointer.
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type Tm1 struct {
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Tm2
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}
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type Tm2 struct {
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*Tm3
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}
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type Tm3 struct {
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*Tm4
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}
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type Tm4 struct {
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}
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func (t4 Tm4) M(x int, b byte) (byte, int) { return b, x + 40 }
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func TestMethod5(t *testing.T) {
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CheckF := func(name string, f func(int, byte) (byte, int), inc int) {
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b, x := f(1000, 99)
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if b != 99 || x != 1000+inc {
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t.Errorf("%s(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
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}
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}
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CheckV := func(name string, i Value, inc int) {
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bx := i.Method(0).Call([]Value{ValueOf(1000), ValueOf(byte(99))})
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b := bx[0].Interface()
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x := bx[1].Interface()
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if b != byte(99) || x != 1000+inc {
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t.Errorf("direct %s.M(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
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}
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CheckF(name+".M", i.Method(0).Interface().(func(int, byte) (byte, int)), inc)
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}
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var TinterType = TypeOf(new(Tinter)).Elem()
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var tinterType = TypeOf(new(tinter)).Elem()
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CheckI := func(name string, i interface{}, inc int) {
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v := ValueOf(i)
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CheckV(name, v, inc)
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CheckV("(i="+name+")", v.Convert(TinterType), inc)
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}
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sv := Tsmallv(1)
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CheckI("sv", sv, 1)
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CheckI("&sv", &sv, 1)
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sp := Tsmallp(2)
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CheckI("&sp", &sp, 2)
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wv := Twordv(3)
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CheckI("wv", wv, 3)
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CheckI("&wv", &wv, 3)
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wp := Twordp(4)
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CheckI("&wp", &wp, 4)
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bv := Tbigv([2]uintptr{5, 6})
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CheckI("bv", bv, 11)
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CheckI("&bv", &bv, 11)
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bp := Tbigp([2]uintptr{7, 8})
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CheckI("&bp", &bp, 15)
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t4 := Tm4{}
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t3 := Tm3{&t4}
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t2 := Tm2{&t3}
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t1 := Tm1{t2}
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CheckI("t4", t4, 40)
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CheckI("&t4", &t4, 40)
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CheckI("t3", t3, 40)
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CheckI("&t3", &t3, 40)
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CheckI("t2", t2, 40)
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CheckI("&t2", &t2, 40)
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CheckI("t1", t1, 40)
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CheckI("&t1", &t1, 40)
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methodShouldPanic := func(name string, i interface{}) {
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v := ValueOf(i)
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m := v.Method(0)
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shouldPanic(func() { m.Call([]Value{ValueOf(1000), ValueOf(byte(99))}) })
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shouldPanic(func() { m.Interface() })
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v = v.Convert(tinterType)
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m = v.Method(0)
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shouldPanic(func() { m.Call([]Value{ValueOf(1000), ValueOf(byte(99))}) })
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shouldPanic(func() { m.Interface() })
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}
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_sv := tsmallv(1)
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methodShouldPanic("_sv", _sv)
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methodShouldPanic("&_sv", &_sv)
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_sp := tsmallp(2)
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methodShouldPanic("&_sp", &_sp)
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_wv := twordv(3)
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methodShouldPanic("_wv", _wv)
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methodShouldPanic("&_wv", &_wv)
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_wp := twordp(4)
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methodShouldPanic("&_wp", &_wp)
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_bv := tbigv([2]uintptr{5, 6})
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methodShouldPanic("_bv", _bv)
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methodShouldPanic("&_bv", &_bv)
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_bp := tbigp([2]uintptr{7, 8})
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methodShouldPanic("&_bp", &_bp)
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var tnil Tinter
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vnil := ValueOf(&tnil).Elem()
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shouldPanic(func() { vnil.Method(0) })
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}
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func TestInterfaceSet(t *testing.T) {
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p := &Point{3, 4}
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@ -3,7 +3,7 @@
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// license that can be found in the LICENSE file.
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// makeFuncStub is the code half of the function returned by MakeFunc.
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// See the comment on the declaration of makeFuncStub in value.go
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// See the comment on the declaration of makeFuncStub in makefunc.go
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// for more details.
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TEXT ·makeFuncStub(SB),7,$8
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MOVL DX, 0(SP)
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@ -11,3 +11,13 @@ TEXT ·makeFuncStub(SB),7,$8
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MOVL CX, 4(SP)
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CALL ·callReflect(SB)
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RET
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// methodValueCall is the code half of the function returned by makeMethodValue.
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// See the comment on the declaration of methodValueCall in makefunc.go
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// for more details.
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TEXT ·methodValueCall(SB),7,$8
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MOVL DX, 0(SP)
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LEAL arg+0(FP), CX
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MOVL CX, 4(SP)
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CALL ·callMethod(SB)
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RET
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@ -3,7 +3,7 @@
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// license that can be found in the LICENSE file.
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// makeFuncStub is the code half of the function returned by MakeFunc.
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// See the comment on the declaration of makeFuncStub in value.go
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// See the comment on the declaration of makeFuncStub in makefunc.go
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// for more details.
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TEXT ·makeFuncStub(SB),7,$16
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MOVQ DX, 0(SP)
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@ -11,3 +11,13 @@ TEXT ·makeFuncStub(SB),7,$16
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MOVQ CX, 8(SP)
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CALL ·callReflect(SB)
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RET
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// methodValueCall is the code half of the function returned by makeMethodValue.
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// See the comment on the declaration of methodValueCall in makefunc.go
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// for more details.
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TEXT ·methodValueCall(SB),7,$16
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MOVQ DX, 0(SP)
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LEAQ arg+0(FP), CX
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MOVQ CX, 8(SP)
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CALL ·callMethod(SB)
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RET
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@ -3,7 +3,7 @@
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// license that can be found in the LICENSE file.
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// makeFuncStub is jumped to by the code generated by MakeFunc.
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// See the comment on the declaration of makeFuncStub in value.go
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// See the comment on the declaration of makeFuncStub in makefunc.go
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// for more details.
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TEXT ·makeFuncStub(SB),7,$8
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MOVW R7, 4(R13)
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@ -11,3 +11,13 @@ TEXT ·makeFuncStub(SB),7,$8
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MOVW R1, 8(R13)
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BL ·callReflect(SB)
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RET
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// methodValueCall is the code half of the function returned by makeMethodValue.
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// See the comment on the declaration of methodValueCall in makefunc.go
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// for more details.
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TEXT ·methodValueCall(SB),7,$8
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MOVW R7, 4(R13)
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MOVW $arg+0(FP), R1
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MOVW R1, 8(R13)
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BL ·callMethod(SB)
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RET
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@ -118,8 +118,6 @@ func deepValueEqual(v1, v2 Value, visited map[uintptr]*visit, depth int) (b bool
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// Normal equality suffices
|
||||
return valueInterface(v1, false) == valueInterface(v2, false)
|
||||
}
|
||||
|
||||
panic("Not reached")
|
||||
}
|
||||
|
||||
// DeepEqual tests for deep equality. It uses normal == equality where
|
||||
|
||||
@ -48,8 +48,8 @@ func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value {
|
||||
t := typ.common()
|
||||
ftyp := (*funcType)(unsafe.Pointer(t))
|
||||
|
||||
// indirect Go func value (dummy) to obtain
|
||||
// actual code address. (A Go func is a pointer
|
||||
// Indirect Go func value (dummy) to obtain
|
||||
// actual code address. (A Go func value is a pointer
|
||||
// to a C function pointer. http://golang.org/s/go11func.)
|
||||
dummy := makeFuncStub
|
||||
code := **(**uintptr)(unsafe.Pointer(&dummy))
|
||||
@ -65,3 +65,56 @@ func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value {
|
||||
// where ctxt is the context register and frame is a pointer to the first
|
||||
// word in the passed-in argument frame.
|
||||
func makeFuncStub()
|
||||
|
||||
type methodValue struct {
|
||||
fn uintptr
|
||||
method int
|
||||
rcvr Value
|
||||
}
|
||||
|
||||
// makeMethodValue converts v from the rcvr+method index representation
|
||||
// of a method value to an actual method func value, which is
|
||||
// basically the receiver value with a special bit set, into a true
|
||||
// func value - a value holding an actual func. The output is
|
||||
// semantically equivalent to the input as far as the user of package
|
||||
// reflect can tell, but the true func representation can be handled
|
||||
// by code like Convert and Interface and Assign.
|
||||
func makeMethodValue(op string, v Value) Value {
|
||||
if v.flag&flagMethod == 0 {
|
||||
panic("reflect: internal error: invalid use of makePartialFunc")
|
||||
}
|
||||
|
||||
// Ignoring the flagMethod bit, v describes the receiver, not the method type.
|
||||
fl := v.flag & (flagRO | flagAddr | flagIndir)
|
||||
fl |= flag(v.typ.Kind()) << flagKindShift
|
||||
rcvr := Value{v.typ, v.val, fl}
|
||||
|
||||
// v.Type returns the actual type of the method value.
|
||||
funcType := v.Type().(*rtype)
|
||||
|
||||
// Indirect Go func value (dummy) to obtain
|
||||
// actual code address. (A Go func value is a pointer
|
||||
// to a C function pointer. http://golang.org/s/go11func.)
|
||||
dummy := methodValueCall
|
||||
code := **(**uintptr)(unsafe.Pointer(&dummy))
|
||||
|
||||
fv := &methodValue{
|
||||
fn: code,
|
||||
method: int(v.flag) >> flagMethodShift,
|
||||
rcvr: rcvr,
|
||||
}
|
||||
|
||||
// Cause panic if method is not appropriate.
|
||||
// The panic would still happen during the call if we omit this,
|
||||
// but we want Interface() and other operations to fail early.
|
||||
methodReceiver(op, fv.rcvr, fv.method)
|
||||
|
||||
return Value{funcType, unsafe.Pointer(fv), v.flag&flagRO | flag(Func)<<flagKindShift}
|
||||
}
|
||||
|
||||
// methodValueCall is an assembly function that is the code half of
|
||||
// the function returned from makeMethodValue. It expects a *methodValue
|
||||
// as its context register, and its job is to invoke callMethod(ctxt, frame)
|
||||
// where ctxt is the context register and frame is a pointer to the first
|
||||
// word in the passed-in argument frame.
|
||||
func methodValueCall()
|
||||
|
||||
@ -249,7 +249,7 @@ func (f flag) mustBeExported() {
|
||||
panic(&ValueError{methodName(), 0})
|
||||
}
|
||||
if f&flagRO != 0 {
|
||||
panic(methodName() + " using value obtained using unexported field")
|
||||
panic("reflect: " + methodName() + " using value obtained using unexported field")
|
||||
}
|
||||
}
|
||||
|
||||
@ -262,10 +262,10 @@ func (f flag) mustBeAssignable() {
|
||||
}
|
||||
// Assignable if addressable and not read-only.
|
||||
if f&flagRO != 0 {
|
||||
panic(methodName() + " using value obtained using unexported field")
|
||||
panic("reflect: " + methodName() + " using value obtained using unexported field")
|
||||
}
|
||||
if f&flagAddr == 0 {
|
||||
panic(methodName() + " using unaddressable value")
|
||||
panic("reflect: " + methodName() + " using unaddressable value")
|
||||
}
|
||||
}
|
||||
|
||||
@ -358,7 +358,7 @@ func (v Value) CallSlice(in []Value) []Value {
|
||||
return v.call("CallSlice", in)
|
||||
}
|
||||
|
||||
func (v Value) call(method string, in []Value) []Value {
|
||||
func (v Value) call(op string, in []Value) []Value {
|
||||
// Get function pointer, type.
|
||||
t := v.typ
|
||||
var (
|
||||
@ -366,36 +366,7 @@ func (v Value) call(method string, in []Value) []Value {
|
||||
rcvr iword
|
||||
)
|
||||
if v.flag&flagMethod != 0 {
|
||||
i := int(v.flag) >> flagMethodShift
|
||||
if v.typ.Kind() == Interface {
|
||||
tt := (*interfaceType)(unsafe.Pointer(v.typ))
|
||||
if i < 0 || i >= len(tt.methods) {
|
||||
panic("reflect: broken Value")
|
||||
}
|
||||
m := &tt.methods[i]
|
||||
if m.pkgPath != nil {
|
||||
panic(method + " of unexported method")
|
||||
}
|
||||
t = m.typ
|
||||
iface := (*nonEmptyInterface)(v.val)
|
||||
if iface.itab == nil {
|
||||
panic(method + " of method on nil interface value")
|
||||
}
|
||||
fn = unsafe.Pointer(&iface.itab.fun[i])
|
||||
rcvr = iface.word
|
||||
} else {
|
||||
ut := v.typ.uncommon()
|
||||
if ut == nil || i < 0 || i >= len(ut.methods) {
|
||||
panic("reflect: broken Value")
|
||||
}
|
||||
m := &ut.methods[i]
|
||||
if m.pkgPath != nil {
|
||||
panic(method + " of unexported method")
|
||||
}
|
||||
fn = unsafe.Pointer(&m.ifn)
|
||||
t = m.mtyp
|
||||
rcvr = v.iword()
|
||||
}
|
||||
t, fn, rcvr = methodReceiver(op, v, int(v.flag)>>flagMethodShift)
|
||||
} else if v.flag&flagIndir != 0 {
|
||||
fn = *(*unsafe.Pointer)(v.val)
|
||||
} else {
|
||||
@ -406,7 +377,7 @@ func (v Value) call(method string, in []Value) []Value {
|
||||
panic("reflect.Value.Call: call of nil function")
|
||||
}
|
||||
|
||||
isSlice := method == "CallSlice"
|
||||
isSlice := op == "CallSlice"
|
||||
n := t.NumIn()
|
||||
if isSlice {
|
||||
if !t.IsVariadic() {
|
||||
@ -431,12 +402,12 @@ func (v Value) call(method string, in []Value) []Value {
|
||||
}
|
||||
for _, x := range in {
|
||||
if x.Kind() == Invalid {
|
||||
panic("reflect: " + method + " using zero Value argument")
|
||||
panic("reflect: " + op + " using zero Value argument")
|
||||
}
|
||||
}
|
||||
for i := 0; i < n; i++ {
|
||||
if xt, targ := in[i].Type(), t.In(i); !xt.AssignableTo(targ) {
|
||||
panic("reflect: " + method + " using " + xt.String() + " as type " + targ.String())
|
||||
panic("reflect: " + op + " using " + xt.String() + " as type " + targ.String())
|
||||
}
|
||||
}
|
||||
if !isSlice && t.IsVariadic() {
|
||||
@ -447,7 +418,7 @@ func (v Value) call(method string, in []Value) []Value {
|
||||
for i := 0; i < m; i++ {
|
||||
x := in[n+i]
|
||||
if xt := x.Type(); !xt.AssignableTo(elem) {
|
||||
panic("reflect: cannot use " + xt.String() + " as type " + elem.String() + " in " + method)
|
||||
panic("reflect: cannot use " + xt.String() + " as type " + elem.String() + " in " + op)
|
||||
}
|
||||
slice.Index(i).Set(x)
|
||||
}
|
||||
@ -467,40 +438,11 @@ func (v Value) call(method string, in []Value) []Value {
|
||||
// This computation is 5g/6g/8g-dependent
|
||||
// and probably wrong for gccgo, but so
|
||||
// is most of this function.
|
||||
size := uintptr(0)
|
||||
if v.flag&flagMethod != 0 {
|
||||
// extra word for receiver interface word
|
||||
size += ptrSize
|
||||
}
|
||||
for i := 0; i < nin; i++ {
|
||||
tv := t.In(i)
|
||||
a := uintptr(tv.Align())
|
||||
size = (size + a - 1) &^ (a - 1)
|
||||
size += tv.Size()
|
||||
}
|
||||
size = (size + ptrSize - 1) &^ (ptrSize - 1)
|
||||
for i := 0; i < nout; i++ {
|
||||
tv := t.Out(i)
|
||||
a := uintptr(tv.Align())
|
||||
size = (size + a - 1) &^ (a - 1)
|
||||
size += tv.Size()
|
||||
}
|
||||
|
||||
// size must be > 0 in order for &args[0] to be valid.
|
||||
// the argument copying is going to round it up to
|
||||
// a multiple of ptrSize anyway, so make it ptrSize to begin with.
|
||||
if size < ptrSize {
|
||||
size = ptrSize
|
||||
}
|
||||
|
||||
// round to pointer size
|
||||
size = (size + ptrSize - 1) &^ (ptrSize - 1)
|
||||
size, _, _, _ := frameSize(t, v.flag&flagMethod != 0)
|
||||
|
||||
// Copy into args.
|
||||
//
|
||||
// TODO(rsc): revisit when reference counting happens.
|
||||
// The values are holding up the in references for us,
|
||||
// but something must be done for the out references.
|
||||
// TODO(rsc): This will need to be updated for any new garbage collector.
|
||||
// For now make everything look like a pointer by allocating
|
||||
// a []unsafe.Pointer.
|
||||
args := make([]unsafe.Pointer, size/ptrSize)
|
||||
@ -616,6 +558,119 @@ func callReflect(ctxt *makeFuncImpl, frame unsafe.Pointer) {
|
||||
}
|
||||
}
|
||||
|
||||
// methodReceiver returns information about the receiver
|
||||
// described by v. The Value v may or may not have the
|
||||
// flagMethod bit set, so the kind cached in v.flag should
|
||||
// not be used.
|
||||
func methodReceiver(op string, v Value, methodIndex int) (t *rtype, fn unsafe.Pointer, rcvr iword) {
|
||||
i := methodIndex
|
||||
if v.typ.Kind() == Interface {
|
||||
tt := (*interfaceType)(unsafe.Pointer(v.typ))
|
||||
if i < 0 || i >= len(tt.methods) {
|
||||
panic("reflect: internal error: invalid method index")
|
||||
}
|
||||
m := &tt.methods[i]
|
||||
if m.pkgPath != nil {
|
||||
panic("reflect: " + op + " of unexported method")
|
||||
}
|
||||
t = m.typ
|
||||
iface := (*nonEmptyInterface)(v.val)
|
||||
if iface.itab == nil {
|
||||
panic("reflect: " + op + " of method on nil interface value")
|
||||
}
|
||||
fn = unsafe.Pointer(&iface.itab.fun[i])
|
||||
rcvr = iface.word
|
||||
} else {
|
||||
ut := v.typ.uncommon()
|
||||
if ut == nil || i < 0 || i >= len(ut.methods) {
|
||||
panic("reflect: internal error: invalid method index")
|
||||
}
|
||||
m := &ut.methods[i]
|
||||
if m.pkgPath != nil {
|
||||
panic("reflect: " + op + " of unexported method")
|
||||
}
|
||||
fn = unsafe.Pointer(&m.ifn)
|
||||
t = m.mtyp
|
||||
rcvr = v.iword()
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
// align returns the result of rounding x up to a multiple of n.
|
||||
// n must be a power of two.
|
||||
func align(x, n uintptr) uintptr {
|
||||
return (x + n - 1) &^ (n - 1)
|
||||
}
|
||||
|
||||
// frameSize returns the sizes of the argument and result frame
|
||||
// for a function of the given type. The rcvr bool specifies whether
|
||||
// a one-word receiver should be included in the total.
|
||||
func frameSize(t *rtype, rcvr bool) (total, in, outOffset, out uintptr) {
|
||||
if rcvr {
|
||||
// extra word for receiver interface word
|
||||
total += ptrSize
|
||||
}
|
||||
|
||||
nin := t.NumIn()
|
||||
in = -total
|
||||
for i := 0; i < nin; i++ {
|
||||
tv := t.In(i)
|
||||
total = align(total, uintptr(tv.Align()))
|
||||
total += tv.Size()
|
||||
}
|
||||
in += total
|
||||
total = align(total, ptrSize)
|
||||
nout := t.NumOut()
|
||||
outOffset = total
|
||||
out = -total
|
||||
for i := 0; i < nout; i++ {
|
||||
tv := t.Out(i)
|
||||
total = align(total, uintptr(tv.Align()))
|
||||
total += tv.Size()
|
||||
}
|
||||
out += total
|
||||
|
||||
// total must be > 0 in order for &args[0] to be valid.
|
||||
// the argument copying is going to round it up to
|
||||
// a multiple of ptrSize anyway, so make it ptrSize to begin with.
|
||||
if total < ptrSize {
|
||||
total = ptrSize
|
||||
}
|
||||
|
||||
// round to pointer
|
||||
total = align(total, ptrSize)
|
||||
|
||||
return
|
||||
}
|
||||
|
||||
// callMethod is the call implementation used by a function returned
|
||||
// by makeMethodValue (used by v.Method(i).Interface()).
|
||||
// It is a streamlined version of the usual reflect call: the caller has
|
||||
// already laid out the argument frame for us, so we don't have
|
||||
// to deal with individual Values for each argument.
|
||||
// It is in this file so that it can be next to the two similar functions above.
|
||||
// The remainder of the makeMethodValue implementation is in makefunc.go.
|
||||
func callMethod(ctxt *methodValue, frame unsafe.Pointer) {
|
||||
t, fn, rcvr := methodReceiver("call", ctxt.rcvr, ctxt.method)
|
||||
total, in, outOffset, out := frameSize(t, true)
|
||||
|
||||
// Copy into args.
|
||||
//
|
||||
// TODO(rsc): This will need to be updated for any new garbage collector.
|
||||
// For now make everything look like a pointer by allocating
|
||||
// a []unsafe.Pointer.
|
||||
args := make([]unsafe.Pointer, total/ptrSize)
|
||||
args[0] = unsafe.Pointer(rcvr)
|
||||
base := unsafe.Pointer(&args[0])
|
||||
memmove(unsafe.Pointer(uintptr(base)+ptrSize), frame, in)
|
||||
|
||||
// Call.
|
||||
call(fn, unsafe.Pointer(&args[0]), uint32(total))
|
||||
|
||||
// Copy return values.
|
||||
memmove(unsafe.Pointer(uintptr(frame)+outOffset-ptrSize), unsafe.Pointer(uintptr(base)+outOffset), out)
|
||||
}
|
||||
|
||||
// funcName returns the name of f, for use in error messages.
|
||||
func funcName(f func([]Value) []Value) string {
|
||||
pc := *(*uintptr)(unsafe.Pointer(&f))
|
||||
@ -902,7 +957,7 @@ func (v Value) CanInterface() bool {
|
||||
if v.flag == 0 {
|
||||
panic(&ValueError{"reflect.Value.CanInterface", Invalid})
|
||||
}
|
||||
return v.flag&(flagMethod|flagRO) == 0
|
||||
return v.flag&flagRO == 0
|
||||
}
|
||||
|
||||
// Interface returns v's current value as an interface{}.
|
||||
@ -921,16 +976,15 @@ func valueInterface(v Value, safe bool) interface{} {
|
||||
if v.flag == 0 {
|
||||
panic(&ValueError{"reflect.Value.Interface", 0})
|
||||
}
|
||||
if v.flag&flagMethod != 0 {
|
||||
panic("reflect.Value.Interface: cannot create interface value for method with bound receiver")
|
||||
}
|
||||
|
||||
if safe && v.flag&flagRO != 0 {
|
||||
// Do not allow access to unexported values via Interface,
|
||||
// because they might be pointers that should not be
|
||||
// writable or methods or function that should not be callable.
|
||||
panic("reflect.Value.Interface: cannot return value obtained from unexported field or method")
|
||||
}
|
||||
if v.flag&flagMethod != 0 {
|
||||
v = makeMethodValue("Interface", v)
|
||||
}
|
||||
|
||||
k := v.kind()
|
||||
if k == Interface {
|
||||
@ -981,7 +1035,7 @@ func (v Value) IsNil() bool {
|
||||
switch k {
|
||||
case Chan, Func, Map, Ptr:
|
||||
if v.flag&flagMethod != 0 {
|
||||
panic("reflect: IsNil of method Value")
|
||||
return false
|
||||
}
|
||||
ptr := v.val
|
||||
if v.flag&flagIndir != 0 {
|
||||
@ -1100,7 +1154,7 @@ func (v Value) MapKeys() []Value {
|
||||
// Method returns a function value corresponding to v's i'th method.
|
||||
// The arguments to a Call on the returned function should not include
|
||||
// a receiver; the returned function will always use v as the receiver.
|
||||
// Method panics if i is out of range.
|
||||
// Method panics if i is out of range or if v is a nil interface value.
|
||||
func (v Value) Method(i int) Value {
|
||||
if v.typ == nil {
|
||||
panic(&ValueError{"reflect.Value.Method", Invalid})
|
||||
@ -1108,7 +1162,10 @@ func (v Value) Method(i int) Value {
|
||||
if v.flag&flagMethod != 0 || i < 0 || i >= v.typ.NumMethod() {
|
||||
panic("reflect: Method index out of range")
|
||||
}
|
||||
fl := v.flag & (flagRO | flagAddr | flagIndir)
|
||||
if v.typ.Kind() == Interface && v.IsNil() {
|
||||
panic("reflect: Method on nil interface value")
|
||||
}
|
||||
fl := v.flag & (flagRO | flagIndir)
|
||||
fl |= flag(Func) << flagKindShift
|
||||
fl |= flag(i)<<flagMethodShift | flagMethod
|
||||
return Value{v.typ, v.val, fl}
|
||||
@ -1232,7 +1289,14 @@ func (v Value) Pointer() uintptr {
|
||||
return uintptr(p)
|
||||
case Func:
|
||||
if v.flag&flagMethod != 0 {
|
||||
panic("reflect.Value.Pointer of method Value")
|
||||
// As the doc comment says, the returned pointer is an
|
||||
// underlying code pointer but not necessarily enough to
|
||||
// identify a single function uniquely. All method expressions
|
||||
// created via reflect have the same underlying code pointer,
|
||||
// so their Pointers are equal. The function used here must
|
||||
// match the one used in makeMethodValue.
|
||||
f := methodValueCall
|
||||
return **(**uintptr)(unsafe.Pointer(&f))
|
||||
}
|
||||
p := v.val
|
||||
if v.flag&flagIndir != 0 {
|
||||
@ -1267,7 +1331,7 @@ func (v Value) Recv() (x Value, ok bool) {
|
||||
func (v Value) recv(nb bool) (val Value, ok bool) {
|
||||
tt := (*chanType)(unsafe.Pointer(v.typ))
|
||||
if ChanDir(tt.dir)&RecvDir == 0 {
|
||||
panic("recv on send-only channel")
|
||||
panic("reflect: recv on send-only channel")
|
||||
}
|
||||
word, selected, ok := chanrecv(v.typ, v.iword(), nb)
|
||||
if selected {
|
||||
@ -1295,7 +1359,7 @@ func (v Value) Send(x Value) {
|
||||
func (v Value) send(x Value, nb bool) (selected bool) {
|
||||
tt := (*chanType)(unsafe.Pointer(v.typ))
|
||||
if ChanDir(tt.dir)&SendDir == 0 {
|
||||
panic("send on recv-only channel")
|
||||
panic("reflect: send on recv-only channel")
|
||||
}
|
||||
x.mustBeExported()
|
||||
x = x.assignTo("reflect.Value.Send", tt.elem, nil)
|
||||
@ -1578,7 +1642,7 @@ func (v Value) Type() Type {
|
||||
// Method on interface.
|
||||
tt := (*interfaceType)(unsafe.Pointer(v.typ))
|
||||
if i < 0 || i >= len(tt.methods) {
|
||||
panic("reflect: broken Value")
|
||||
panic("reflect: internal error: invalid method index")
|
||||
}
|
||||
m := &tt.methods[i]
|
||||
return m.typ
|
||||
@ -1586,7 +1650,7 @@ func (v Value) Type() Type {
|
||||
// Method on concrete type.
|
||||
ut := v.typ.uncommon()
|
||||
if ut == nil || i < 0 || i >= len(ut.methods) {
|
||||
panic("reflect: broken Value")
|
||||
panic("reflect: internal error: invalid method index")
|
||||
}
|
||||
m := &ut.methods[i]
|
||||
return m.mtyp
|
||||
@ -2030,7 +2094,7 @@ func NewAt(typ Type, p unsafe.Pointer) Value {
|
||||
// For a conversion to an interface type, target is a suggested scratch space to use.
|
||||
func (v Value) assignTo(context string, dst *rtype, target *interface{}) Value {
|
||||
if v.flag&flagMethod != 0 {
|
||||
panic(context + ": cannot assign method value to type " + dst.String())
|
||||
v = makeMethodValue(context, v)
|
||||
}
|
||||
|
||||
switch {
|
||||
@ -2064,7 +2128,7 @@ func (v Value) assignTo(context string, dst *rtype, target *interface{}) Value {
|
||||
// of the value v to type t, Convert panics.
|
||||
func (v Value) Convert(t Type) Value {
|
||||
if v.flag&flagMethod != 0 {
|
||||
panic("reflect.Value.Convert: cannot convert method values")
|
||||
v = makeMethodValue("Convert", v)
|
||||
}
|
||||
op := convertOp(t.common(), v.typ)
|
||||
if op == nil {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user