// Arguments of OADDSTR never escape;
// runtime.concatstrings makes sure of that.
e.discards(n.List)
+
+ case ir.ODYNAMICTYPE:
+ // Nothing to do - argument is a *runtime._type (+ maybe a *runtime.itab) pointing to static data section
}
}
return n
}
+func (n *DynamicTypeAssertExpr) SetOp(op Op) {
+ switch op {
+ default:
+ panic(n.no("SetOp " + op.String()))
+ case ODYNAMICDOTTYPE, ODYNAMICDOTTYPE2:
+ n.op = op
+ }
+}
+
// A UnaryExpr is a unary expression Op X,
// or Op(X) for a builtin function that does not end up being a call.
type UnaryExpr struct {
OBREAK // break [Label]
// OCASE: case List: Body (List==nil means default)
// For OTYPESW, List is a OTYPE node for the specified type (or OLITERAL
- // for nil), and, if a type-switch variable is specified, Rlist is an
+ // for nil) or an ODYNAMICTYPE indicating a runtime type for generics.
+ // If a type-switch variable is specified, Var is an
// ONAME for the version of the type-switch variable with the specified
// type.
OCASE
OLINKSYMOFFSET // offset within a name
// opcodes for generics
- ODYNAMICDOTTYPE
- ODYNAMICDOTTYPE2
+ ODYNAMICDOTTYPE // x = i.(T) where T is a type parameter (or derived from a type parameter)
+ ODYNAMICDOTTYPE2 // x, ok = i.(T) where T is a type parameter (or derived from a type parameter)
+ ODYNAMICTYPE // a type node for type switches (represents a dynamic target type for a type switch)
// arch-specific opcodes
OTAILCALL // tail call to another function
}
}
+func (n *DynamicType) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
+func (n *DynamicType) copy() Node {
+ c := *n
+ c.init = copyNodes(c.init)
+ return &c
+}
+func (n *DynamicType) doChildren(do func(Node) bool) bool {
+ if doNodes(n.init, do) {
+ return true
+ }
+ if n.X != nil && do(n.X) {
+ return true
+ }
+ if n.ITab != nil && do(n.ITab) {
+ return true
+ }
+ return false
+}
+func (n *DynamicType) editChildren(edit func(Node) Node) {
+ editNodes(n.init, edit)
+ if n.X != nil {
+ n.X = edit(n.X).(Node)
+ }
+ if n.ITab != nil {
+ n.ITab = edit(n.ITab).(Node)
+ }
+}
+
func (n *DynamicTypeAssertExpr) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
func (n *DynamicTypeAssertExpr) copy() Node {
c := *n
_ = x[OLINKSYMOFFSET-153]
_ = x[ODYNAMICDOTTYPE-154]
_ = x[ODYNAMICDOTTYPE2-155]
- _ = x[OTAILCALL-156]
- _ = x[OGETG-157]
- _ = x[OGETCALLERPC-158]
- _ = x[OGETCALLERSP-159]
- _ = x[OEND-160]
+ _ = x[ODYNAMICTYPE-156]
+ _ = x[OTAILCALL-157]
+ _ = x[OGETG-158]
+ _ = x[OGETCALLERPC-159]
+ _ = x[OGETCALLERSP-160]
+ _ = x[OEND-161]
}
-const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVIDATACONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECOVERFPRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEMETHEXPRMETHVALUEBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETDYNAMICDOTTYPEDYNAMICDOTTYPE2TAILCALLGETGGETCALLERPCGETCALLERSPEND"
+const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVIDATACONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECOVERFPRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEMETHEXPRMETHVALUEBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETDYNAMICDOTTYPEDYNAMICDOTTYPE2DYNAMICTYPETAILCALLGETGGETCALLERPCGETCALLERSPEND"
-var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 136, 138, 141, 151, 158, 165, 172, 176, 180, 188, 196, 205, 208, 213, 220, 227, 233, 242, 250, 258, 264, 268, 277, 286, 293, 297, 300, 307, 315, 322, 328, 331, 337, 344, 352, 356, 363, 371, 373, 375, 377, 379, 381, 383, 388, 393, 401, 404, 413, 416, 420, 428, 435, 444, 457, 460, 463, 466, 469, 472, 475, 481, 484, 487, 493, 497, 500, 504, 509, 514, 520, 525, 529, 534, 542, 550, 556, 565, 576, 583, 592, 596, 603, 611, 615, 619, 623, 630, 637, 645, 651, 660, 671, 679, 688, 693, 698, 702, 710, 715, 719, 722, 730, 734, 736, 741, 743, 748, 754, 760, 766, 772, 780, 785, 789, 796, 802, 807, 813, 819, 826, 831, 835, 840, 844, 849, 857, 863, 870, 877, 883, 890, 903, 917, 932, 940, 944, 955, 966, 969}
+var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 136, 138, 141, 151, 158, 165, 172, 176, 180, 188, 196, 205, 208, 213, 220, 227, 233, 242, 250, 258, 264, 268, 277, 286, 293, 297, 300, 307, 315, 322, 328, 331, 337, 344, 352, 356, 363, 371, 373, 375, 377, 379, 381, 383, 388, 393, 401, 404, 413, 416, 420, 428, 435, 444, 457, 460, 463, 466, 469, 472, 475, 481, 484, 487, 493, 497, 500, 504, 509, 514, 520, 525, 529, 534, 542, 550, 556, 565, 576, 583, 592, 596, 603, 611, 615, 619, 623, 630, 637, 645, 651, 660, 671, 679, 688, 693, 698, 702, 710, 715, 719, 722, 730, 734, 736, 741, 743, 748, 754, 760, 766, 772, 780, 785, 789, 796, 802, 807, 813, 819, 826, 831, 835, 840, 844, 849, 857, 863, 870, 877, 883, 890, 903, 917, 932, 943, 951, 955, 966, 977, 980}
func (i Op) String() string {
if i >= Op(len(_Op_index)-1) {
}
return newTypeNode(pos, t)
}
+
+// A DynamicType represents the target type in a type switch.
+type DynamicType struct {
+ miniExpr
+ X Node // a *runtime._type for the targeted type
+ ITab Node // for type switches from nonempty interfaces to non-interfaces, this is the itab for that pair.
+}
+
+func NewDynamicType(pos src.XPos, x Node) *DynamicType {
+ n := &DynamicType{X: x}
+ n.pos = pos
+ n.op = ODYNAMICTYPE
+ return n
+}
// Nodes in generic functions that are a conversion from a typeparam/derived
// type to a specific interface.
itabConvs []ir.Node
+ // For type switches on nonempty interfaces, a map from OTYPE entries of
+ // HasTParam type, to the interface type we're switching from.
+ // TODO: what if the type we're switching from is a shape type?
+ type2switchType map[ir.Node]*types.Type
}
// instInfo is information gathered on an gcshape (or fully concrete)
m = ir.NewDynamicTypeAssertExpr(dt.Pos(), op, dt.X, rt)
m.SetType(dt.Type())
m.SetTypecheck(1)
+ case ir.OCASE:
+ if _, ok := x.(*ir.CommClause); ok {
+ // This is not a type switch. TODO: Should we use an OSWITCH case here instead of OCASE?
+ break
+ }
+ x := x.(*ir.CaseClause)
+ m := m.(*ir.CaseClause)
+ for i, c := range x.List {
+ if c.Op() == ir.OTYPE && c.Type().HasTParam() {
+ // Use a *runtime._type for the dynamic type.
+ ix := findDictType(subst.info, c.Type())
+ assert(ix >= 0)
+ dt := ir.NewDynamicType(c.Pos(), getDictionaryEntry(c.Pos(), subst.info.dictParam, ix, subst.info.dictLen))
+
+ // For type switch from nonemoty interfaces to non-interfaces, we need an itab as well.
+ if _, ok := subst.info.gfInfo.type2switchType[c]; ok {
+ // Type switch from nonempty interface. We need a *runtime.itab
+ // for the dynamic type.
+ ix := -1
+ for i, ic := range subst.info.gfInfo.itabConvs {
+ if ic == c {
+ ix = subst.info.startItabConv + i
+ break
+ }
+ }
+ assert(ix >= 0)
+ dt.ITab = getDictionaryEntry(c.Pos(), subst.info.dictParam, ix, subst.info.dictLen)
+ }
+ typed(m.List[i].Type(), dt)
+ m.List[i] = dt
+ }
+ }
}
return m
}
case ir.OCONVIFACE:
srctype = subst.Typ(n.(*ir.ConvExpr).X.Type())
dsttype = subst.Typ(n.Type())
+ case ir.OTYPE:
+ srctype = subst.Typ(n.Type())
+ dsttype = subst.Typ(info.type2switchType[n])
default:
base.Fatalf("itab entry with unknown op %s", n.Op())
}
ir.Visit(n1, visitFunc)
}
}
+ if n.Op() == ir.OSWITCH && n.(*ir.SwitchStmt).Tag != nil && n.(*ir.SwitchStmt).Tag.Op() == ir.OTYPESW && !n.(*ir.SwitchStmt).Tag.(*ir.TypeSwitchGuard).X.Type().IsEmptyInterface() {
+ for _, cc := range n.(*ir.SwitchStmt).Cases {
+ for _, c := range cc.List {
+ if c.Op() == ir.OTYPE && c.Type().HasTParam() {
+ // Type switch from a non-empty interface to a noninterface.
+ infoPrint(" Itab for type switch: %v\n", c)
+ info.itabConvs = append(info.itabConvs, c)
+ if info.type2switchType == nil {
+ info.type2switchType = map[ir.Node]*types.Type{}
+ }
+ info.type2switchType[c] = n.(*ir.SwitchStmt).Tag.(*ir.TypeSwitchGuard).X.Type()
+ }
+ }
+ }
+ }
addType(&info, n, n.Type())
}
r := r.(*ir.TypeAssertExpr)
stmt.SetOp(ir.OAS2DOTTYPE)
r.SetOp(ir.ODOTTYPE2)
+ case ir.ODYNAMICDOTTYPE:
+ r := r.(*ir.DynamicTypeAssertExpr)
+ stmt.SetOp(ir.OAS2DOTTYPE)
+ r.SetOp(ir.ODYNAMICDOTTYPE2)
default:
break assignOK
}
r := r.(*ir.TypeAssertExpr)
stmt.SetOp(ir.OAS2DOTTYPE)
r.SetOp(ir.ODOTTYPE2)
+ case ir.ODYNAMICDOTTYPE:
+ r := r.(*ir.DynamicTypeAssertExpr)
+ stmt.SetOp(ir.OAS2DOTTYPE)
+ r.SetOp(ir.ODYNAMICDOTTYPE2)
default:
break assignOK
}
}
if singleType != nil && singleType.IsInterface() {
- s.Add(ncase.Pos(), n1.Type(), caseVar, jmp)
+ s.Add(ncase.Pos(), n1, caseVar, jmp)
caseVarInitialized = true
} else {
- s.Add(ncase.Pos(), n1.Type(), nil, jmp)
+ s.Add(ncase.Pos(), n1, nil, jmp)
}
}
}
val = ifaceData(ncase.Pos(), s.facename, singleType)
}
+ if len(ncase.List) == 1 && ncase.List[0].Op() == ir.ODYNAMICTYPE {
+ dt := ncase.List[0].(*ir.DynamicType)
+ x := ir.NewDynamicTypeAssertExpr(ncase.Pos(), ir.ODYNAMICDOTTYPE, val, dt.X)
+ if dt.ITab != nil {
+ // TODO: make ITab a separate field in DynamicTypeAssertExpr?
+ x.T = dt.ITab
+ }
+ x.SetType(caseVar.Type())
+ x.SetTypecheck(1)
+ val = x
+ }
l := []ir.Node{
ir.NewDecl(ncase.Pos(), ir.ODCL, caseVar),
ir.NewAssignStmt(ncase.Pos(), caseVar, val),
body ir.Nodes
}
-func (s *typeSwitch) Add(pos src.XPos, typ *types.Type, caseVar *ir.Name, jmp ir.Node) {
+func (s *typeSwitch) Add(pos src.XPos, n1 ir.Node, caseVar *ir.Name, jmp ir.Node) {
+ typ := n1.Type()
var body ir.Nodes
if caseVar != nil {
l := []ir.Node{
// cv, ok = iface.(type)
as := ir.NewAssignListStmt(pos, ir.OAS2, nil, nil)
as.Lhs = []ir.Node{caseVar, s.okname} // cv, ok =
- dot := ir.NewTypeAssertExpr(pos, s.facename, nil)
- dot.SetType(typ) // iface.(type)
- as.Rhs = []ir.Node{dot}
+ switch n1.Op() {
+ case ir.OTYPE:
+ // Static type assertion (non-generic)
+ dot := ir.NewTypeAssertExpr(pos, s.facename, nil)
+ dot.SetType(typ) // iface.(type)
+ as.Rhs = []ir.Node{dot}
+ case ir.ODYNAMICTYPE:
+ // Dynamic type assertion (generic)
+ dt := n1.(*ir.DynamicType)
+ dot := ir.NewDynamicTypeAssertExpr(pos, ir.ODYNAMICDOTTYPE, s.facename, dt.X)
+ if dt.ITab != nil {
+ dot.T = dt.ITab
+ }
+ dot.SetType(typ)
+ dot.SetTypecheck(1)
+ as.Rhs = []ir.Node{dot}
+ default:
+ base.Fatalf("unhandled type case %s", n1.Op())
+ }
appendWalkStmt(&body, as)
// if ok { goto label }
nif.Body = []ir.Node{jmp}
body.Append(nif)
- if !typ.IsInterface() {
+ if n1.Op() == ir.OTYPE && !typ.IsInterface() {
+ // Defer static, noninterface cases so they can be binary searched by hash.
s.clauses = append(s.clauses, typeClause{
- hash: types.TypeHash(typ),
+ hash: types.TypeHash(n1.Type()),
body: body,
})
return
--- /dev/null
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+func f[T any](i interface{}) {
+ switch i.(type) {
+ case T:
+ println("T")
+ case int:
+ println("int")
+ case int32, int16:
+ println("int32/int16")
+ case struct { a, b T }:
+ println("struct{T,T}")
+ default:
+ println("other")
+ }
+}
+func main() {
+ f[float64](float64(6))
+ f[float64](int(7))
+ f[float64](int32(8))
+ f[float64](struct{a, b float64}{a:1, b:2})
+ f[float64](int8(9))
+}
--- /dev/null
+T
+int
+int32/int16
+struct{T,T}
+other
--- /dev/null
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "reflect"
+
+func f[T any](i interface{}) {
+ switch x := i.(type) {
+ case T:
+ println("T", x)
+ case int:
+ println("int", x)
+ case int32, int16:
+ println("int32/int16", reflect.ValueOf(x).Int())
+ case struct { a, b T }:
+ println("struct{T,T}", x.a, x.b)
+ default:
+ println("other", reflect.ValueOf(x).Int())
+ }
+}
+func main() {
+ f[float64](float64(6))
+ f[float64](int(7))
+ f[float64](int32(8))
+ f[float64](struct{a, b float64}{a:1, b:2})
+ f[float64](int8(9))
+}
--- /dev/null
+T +6.000000e+000
+int 7
+int32/int16 8
+struct{T,T} +1.000000e+000 +2.000000e+000
+other 9
--- /dev/null
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type I interface { foo() int }
+
+type myint int
+
+func (x myint) foo() int { return int(x) }
+
+type myfloat float64
+func (x myfloat) foo() int { return int(x) }
+
+type myint32 int32
+func (x myint32) foo() int { return int(x) }
+
+func f[T I](i I) {
+ switch x := i.(type) {
+ case T:
+ println("T", x.foo())
+ case myint:
+ println("myint", x.foo())
+ default:
+ println("other", x.foo())
+ }
+}
+func main() {
+ f[myfloat](myint(6))
+ f[myfloat](myfloat(7))
+ f[myfloat](myint32(8))
+}
--- /dev/null
+myint 6
+T 7
+other 8
--- /dev/null
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type I interface { foo() int }
+
+type myint int
+
+func (x myint) foo() int {return int(x)}
+
+type myfloat float64
+func (x myfloat) foo() int {return int(x)}
+
+type myint32 int32
+func (x myint32) foo() int { return int(x) }
+
+func f[T I](i I) {
+ switch x := i.(type) {
+ case T, myint32:
+ println("T/myint32", x.foo())
+ default:
+ println("other", x.foo())
+ }
+}
+func main() {
+ f[myfloat](myint(6))
+ f[myfloat](myfloat(7))
+ f[myfloat](myint32(8))
+}
--- /dev/null
+other 6
+T/myint32 7
+T/myint32 8
--- /dev/null
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+type myint int
+func (x myint) foo() int {return int(x)}
+
+type myfloat float64
+func (x myfloat) foo() float64 {return float64(x) }
+
+func f[T any](i interface{}) {
+ switch x := i.(type) {
+ case interface { foo() T }:
+ println("fooer", x.foo())
+ default:
+ println("other")
+ }
+}
+func main() {
+ f[int](myint(6))
+ f[int](myfloat(7))
+ f[float64](myint(8))
+ f[float64](myfloat(9))
+}
--- /dev/null
+fooer 6
+other
+other
+fooer +9.000000e+000