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author | Cuong Manh Le <cuong@orijtech.com> | 2020-10-03 01:23:47 +0700 |
---|---|---|
committer | Cuong Manh Le <cuong.manhle.vn@gmail.com> | 2020-10-09 02:14:32 +0000 |
commit | 8f26b57f9afc238bdecb9b7030bc2f4364093885 (patch) | |
tree | 0b9f9dba3d2c38f61735db9faae6a0061db9f6cb /src/reflect | |
parent | f8df205e74d5122c43f41923280451641e566ee2 (diff) | |
download | go-8f26b57f9afc238bdecb9b7030bc2f4364093885.tar.gz go-8f26b57f9afc238bdecb9b7030bc2f4364093885.zip |
cmd/compile: split exported/non-exported methods for interface type
Currently, mhdr/methods is emitted with the same len/cap. There's no way
to distinguish between exported and non-exported methods statically.
This CL splits mhdr/methods into two parts, use "len" for number of
exported methods, and "cap" for all methods. This fixes the bug in
issue #22075, which intends to return the number of exported methods but
currently return all methods.
Note that with this encoding, we still can access either
all/exported-only/non-exported-only methods:
mhdr[:cap(mhdr)] // all methods
mhdr // exported methods
mhdr[len(mhdr):cap(mhdr)] // non-exported methods
Thank to Matthew Dempsky (@mdempsky) for suggesting this encoding.
Fixes #22075
Change-Id: If662adb03ccff27407d55a5578a0ed05a15e7cdd
Reviewed-on: https://go-review.googlesource.com/c/go/+/259237
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Diffstat (limited to 'src/reflect')
-rw-r--r-- | src/reflect/all_test.go | 18 | ||||
-rw-r--r-- | src/reflect/type.go | 55 | ||||
-rw-r--r-- | src/reflect/value.go | 21 |
3 files changed, 58 insertions, 36 deletions
diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go index a12712d254..be15362aae 100644 --- a/src/reflect/all_test.go +++ b/src/reflect/all_test.go @@ -2995,6 +2995,14 @@ func TestUnexportedMethods(t *testing.T) { if got := typ.NumMethod(); got != 0 { t.Errorf("NumMethod=%d, want 0 satisfied methods", got) } + + var i unexpI + if got := TypeOf(&i).Elem().NumMethod(); got != 0 { + t.Errorf("NumMethod=%d, want 0 satisfied methods", got) + } + if got := ValueOf(&i).Elem().NumMethod(); got != 0 { + t.Errorf("NumMethod=%d, want 0 satisfied methods", got) + } } type InnerInt struct { @@ -3648,21 +3656,21 @@ func TestCallPanic(t *testing.T) { v := ValueOf(T{i, i, i, i, T2{i, i}, i, i, T2{i, i}}) badCall(func() { call(v.Field(0).Method(0)) }) // .t0.W badCall(func() { call(v.Field(0).Elem().Method(0)) }) // .t0.W - badCall(func() { call(v.Field(0).Method(1)) }) // .t0.w + badMethod(func() { call(v.Field(0).Method(1)) }) // .t0.w badMethod(func() { call(v.Field(0).Elem().Method(2)) }) // .t0.w ok(func() { call(v.Field(1).Method(0)) }) // .T1.Y ok(func() { call(v.Field(1).Elem().Method(0)) }) // .T1.Y - badCall(func() { call(v.Field(1).Method(1)) }) // .T1.y + badMethod(func() { call(v.Field(1).Method(1)) }) // .T1.y badMethod(func() { call(v.Field(1).Elem().Method(2)) }) // .T1.y ok(func() { call(v.Field(2).Method(0)) }) // .NamedT0.W ok(func() { call(v.Field(2).Elem().Method(0)) }) // .NamedT0.W - badCall(func() { call(v.Field(2).Method(1)) }) // .NamedT0.w + badMethod(func() { call(v.Field(2).Method(1)) }) // .NamedT0.w badMethod(func() { call(v.Field(2).Elem().Method(2)) }) // .NamedT0.w ok(func() { call(v.Field(3).Method(0)) }) // .NamedT1.Y ok(func() { call(v.Field(3).Elem().Method(0)) }) // .NamedT1.Y - badCall(func() { call(v.Field(3).Method(1)) }) // .NamedT1.y + badMethod(func() { call(v.Field(3).Method(1)) }) // .NamedT1.y badMethod(func() { call(v.Field(3).Elem().Method(3)) }) // .NamedT1.y ok(func() { call(v.Field(4).Field(0).Method(0)) }) // .NamedT2.T1.Y @@ -3672,7 +3680,7 @@ func TestCallPanic(t *testing.T) { badCall(func() { call(v.Field(5).Method(0)) }) // .namedT0.W badCall(func() { call(v.Field(5).Elem().Method(0)) }) // .namedT0.W - badCall(func() { call(v.Field(5).Method(1)) }) // .namedT0.w + badMethod(func() { call(v.Field(5).Method(1)) }) // .namedT0.w badMethod(func() { call(v.Field(5).Elem().Method(2)) }) // .namedT0.w badCall(func() { call(v.Field(6).Method(0)) }) // .namedT1.Y diff --git a/src/reflect/type.go b/src/reflect/type.go index a3a616701b..0b34ca0c94 100644 --- a/src/reflect/type.go +++ b/src/reflect/type.go @@ -386,10 +386,14 @@ type imethod struct { // interfaceType represents an interface type. type interfaceType struct { rtype - pkgPath name // import path - methods []imethod // sorted by hash + pkgPath name // import path + expMethods []imethod // sorted by name, see runtime/type.go:interfacetype to see how it is encoded. } +// methods returns t's full method set, both exported and non-exported. +func (t *interfaceType) methods() []imethod { return t.expMethods[:cap(t.expMethods)] } +func (t *interfaceType) isEmpty() bool { return cap(t.expMethods) == 0 } + // mapType represents a map type. type mapType struct { rtype @@ -1049,25 +1053,22 @@ func (d ChanDir) String() string { // Method returns the i'th method in the type's method set. func (t *interfaceType) Method(i int) (m Method) { - if i < 0 || i >= len(t.methods) { - return + if i < 0 || i >= len(t.expMethods) { + panic("reflect: Method index out of range") } - p := &t.methods[i] + p := &t.expMethods[i] pname := t.nameOff(p.name) m.Name = pname.name() if !pname.isExported() { - m.PkgPath = pname.pkgPath() - if m.PkgPath == "" { - m.PkgPath = t.pkgPath.name() - } + panic("reflect: unexported method: " + pname.name()) } m.Type = toType(t.typeOff(p.typ)) m.Index = i return } -// NumMethod returns the number of interface methods in the type's method set. -func (t *interfaceType) NumMethod() int { return len(t.methods) } +// NumMethod returns the number of exported interface methods in the type's method set. +func (t *interfaceType) NumMethod() int { return len(t.expMethods) } // MethodByName method with the given name in the type's method set. func (t *interfaceType) MethodByName(name string) (m Method, ok bool) { @@ -1075,8 +1076,8 @@ func (t *interfaceType) MethodByName(name string) (m Method, ok bool) { return } var p *imethod - for i := range t.methods { - p = &t.methods[i] + for i := range t.expMethods { + p = &t.expMethods[i] if t.nameOff(p.name).name() == name { return t.Method(i), true } @@ -1485,9 +1486,10 @@ func implements(T, V *rtype) bool { return false } t := (*interfaceType)(unsafe.Pointer(T)) - if len(t.methods) == 0 { + if t.isEmpty() { return true } + tmethods := t.methods() // The same algorithm applies in both cases, but the // method tables for an interface type and a concrete type @@ -1504,10 +1506,11 @@ func implements(T, V *rtype) bool { if V.Kind() == Interface { v := (*interfaceType)(unsafe.Pointer(V)) i := 0 - for j := 0; j < len(v.methods); j++ { - tm := &t.methods[i] + vmethods := v.methods() + for j := 0; j < len(vmethods); j++ { + tm := &tmethods[i] tmName := t.nameOff(tm.name) - vm := &v.methods[j] + vm := &vmethods[j] vmName := V.nameOff(vm.name) if vmName.name() == tmName.name() && V.typeOff(vm.typ) == t.typeOff(tm.typ) { if !tmName.isExported() { @@ -1523,7 +1526,7 @@ func implements(T, V *rtype) bool { continue } } - if i++; i >= len(t.methods) { + if i++; i >= len(tmethods) { return true } } @@ -1538,7 +1541,7 @@ func implements(T, V *rtype) bool { i := 0 vmethods := v.methods() for j := 0; j < int(v.mcount); j++ { - tm := &t.methods[i] + tm := &tmethods[i] tmName := t.nameOff(tm.name) vm := vmethods[j] vmName := V.nameOff(vm.name) @@ -1556,7 +1559,7 @@ func implements(T, V *rtype) bool { continue } } - if i++; i >= len(t.methods) { + if i++; i >= len(tmethods) { return true } } @@ -1658,7 +1661,7 @@ func haveIdenticalUnderlyingType(T, V *rtype, cmpTags bool) bool { case Interface: t := (*interfaceType)(unsafe.Pointer(T)) v := (*interfaceType)(unsafe.Pointer(V)) - if len(t.methods) == 0 && len(v.methods) == 0 { + if t.isEmpty() && v.isEmpty() { return true } // Might have the same methods but still @@ -2442,7 +2445,7 @@ func StructOf(fields []StructField) Type { switch f.typ.Kind() { case Interface: ift := (*interfaceType)(unsafe.Pointer(ft)) - for im, m := range ift.methods { + for im, m := range ift.methods() { if ift.nameOff(m.name).pkgPath() != "" { // TODO(sbinet). Issue 15924. panic("reflect: embedded interface with unexported method(s) not implemented") @@ -3149,3 +3152,11 @@ func addTypeBits(bv *bitVector, offset uintptr, t *rtype) { } } } + +func isEmptyIface(rt *rtype) bool { + if rt.Kind() != Interface { + return false + } + tt := (*interfaceType)(unsafe.Pointer(rt)) + return len(tt.methods()) == 0 +} diff --git a/src/reflect/value.go b/src/reflect/value.go index a14131e1f8..bb6371b867 100644 --- a/src/reflect/value.go +++ b/src/reflect/value.go @@ -635,10 +635,11 @@ func methodReceiver(op string, v Value, methodIndex int) (rcvrtype *rtype, t *fu i := methodIndex if v.typ.Kind() == Interface { tt := (*interfaceType)(unsafe.Pointer(v.typ)) - if uint(i) >= uint(len(tt.methods)) { + ttmethods := tt.methods() + if uint(i) >= uint(len(ttmethods)) { panic("reflect: internal error: invalid method index") } - m := &tt.methods[i] + m := &ttmethods[i] if !tt.nameOff(m.name).isExported() { panic("reflect: " + op + " of unexported method") } @@ -812,7 +813,7 @@ func (v Value) Elem() Value { switch k { case Interface: var eface interface{} - if v.typ.NumMethod() == 0 { + if isEmptyIface(v.typ) { eface = *(*interface{})(v.ptr) } else { eface = (interface{})(*(*interface { @@ -1033,7 +1034,7 @@ func valueInterface(v Value, safe bool) interface{} { // Special case: return the element inside the interface. // Empty interface has one layout, all interfaces with // methods have a second layout. - if v.NumMethod() == 0 { + if isEmptyIface(v.typ) { return *(*interface{})(v.ptr) } return *(*interface { @@ -1908,10 +1909,11 @@ func (v Value) Type() Type { if v.typ.Kind() == Interface { // Method on interface. tt := (*interfaceType)(unsafe.Pointer(v.typ)) - if uint(i) >= uint(len(tt.methods)) { + ttmethods := tt.methods() + if uint(i) >= uint(len(ttmethods)) { panic("reflect: internal error: invalid method index") } - m := &tt.methods[i] + m := &ttmethods[i] return v.typ.typeOff(m.typ) } // Method on concrete type. @@ -2429,7 +2431,7 @@ func (v Value) assignTo(context string, dst *rtype, target unsafe.Pointer) Value return Value{dst, nil, flag(Interface)} } x := valueInterface(v, false) - if dst.NumMethod() == 0 { + if isEmptyIface(dst) { *(*interface{})(target) = x } else { ifaceE2I(dst, x, target) @@ -2718,10 +2720,11 @@ func cvtDirect(v Value, typ Type) Value { func cvtT2I(v Value, typ Type) Value { target := unsafe_New(typ.common()) x := valueInterface(v, false) - if typ.NumMethod() == 0 { + rt := typ.(*rtype) + if isEmptyIface(rt) { *(*interface{})(target) = x } else { - ifaceE2I(typ.(*rtype), x, target) + ifaceE2I(rt, x, target) } return Value{typ.common(), target, v.flag.ro() | flagIndir | flag(Interface)} } |