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[dev.typeparams] cmd/compile: introduce named gcshape types

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Still 1-1 with real types, but now with their own names!

Shape types are implicitly convertible to (and convertible from)
the types they represent.

Change-Id: I0133a8d8fbeb369380574b075a32b3c987e314d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/335170
Run-TryBot: Keith Randall <khr@golang.org>
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Dan Scales <danscales@google.com>
This commit is contained in:
Keith Randall 2021-06-09 19:30:16 -07:00
parent 897970688b
commit a7a17f0ca8
7 changed files with 317 additions and 32 deletions
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150
src/cmd/compile/internal/noder/stencil.go
View file

@ -128,6 +128,7 @@ func (g *irgen) stencil() {
// call.
call.Args.Prepend(inst.X.(*ir.SelectorExpr).X)
}
// Add dictionary to argument list.
call.Args.Prepend(dictValue)
// Transform the Call now, which changes OCALL
@ -486,6 +487,10 @@ func (g *irgen) buildClosure(outer *ir.Func, x ir.Node) ir.Node {
func (g *irgen) instantiateMethods() {
for i := 0; i < len(g.instTypeList); i++ {
typ := g.instTypeList[i]
if typ.HasShape() {
// Shape types should not have any methods.
continue
}
// Mark runtime type as needed, since this ensures that the
// compiler puts out the needed DWARF symbols, when this
// instantiated type has a different package from the local
@ -781,7 +786,12 @@ func checkFetchBody(nameNode *ir.Name) {
// cached, then it calls genericSubst to create the new instantiation.
func (g *irgen) getInstantiation(nameNode *ir.Name, targs []*types.Type, isMeth bool) *ir.Func {
checkFetchBody(nameNode)
sym := typecheck.MakeInstName(nameNode.Sym(), targs, isMeth)
// Convert type arguments to their shape, so we can reduce the number
// of instantiations we have to generate.
shapes := typecheck.ShapifyList(targs)
sym := typecheck.MakeInstName(nameNode.Sym(), shapes, isMeth)
info := g.instInfoMap[sym]
if info == nil {
if false {
@ -802,7 +812,7 @@ func (g *irgen) getInstantiation(nameNode *ir.Name, targs []*types.Type, isMeth
dictEntryMap: make(map[ir.Node]int),
}
// genericSubst fills in info.dictParam and info.dictEntryMap.
st := g.genericSubst(sym, nameNode, targs, isMeth, info)
st := g.genericSubst(sym, nameNode, shapes, targs, isMeth, info)
info.fun = st
g.instInfoMap[sym] = info
// This ensures that the linker drops duplicates of this instantiation.
@ -824,6 +834,18 @@ type subster struct {
newf *ir.Func // Func node for the new stenciled function
ts typecheck.Tsubster
info *instInfo // Place to put extra info in the instantiation
// Which type parameter the shape type came from.
shape2param map[*types.Type]*types.Type
// unshapeify maps from shape types to the concrete types they represent.
// TODO: remove when we no longer need it.
unshapify typecheck.Tsubster
concretify typecheck.Tsubster
// TODO: some sort of map from <shape type, interface type> to index in the
// dictionary where a *runtime.itab for the corresponding <concrete type,
// interface type> pair resides.
}
// genericSubst returns a new function with name newsym. The function is an
@ -832,7 +854,7 @@ type subster struct {
// function type where the receiver becomes the first parameter. Otherwise the
// instantiated method would still need to be transformed by later compiler
// phases. genericSubst fills in info.dictParam and info.dictEntryMap.
func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, targs []*types.Type, isMethod bool, info *instInfo) *ir.Func {
func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, shapes, targs []*types.Type, isMethod bool, info *instInfo) *ir.Func {
var tparams []*types.Type
if isMethod {
// Get the type params from the method receiver (after skipping
@ -847,6 +869,11 @@ func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, targs []*type
tparams[i] = f.Type
}
}
for i := range targs {
if targs[i].HasShape() {
base.Fatalf("generiSubst shape %s %+v %+v\n", newsym.Name, shapes[i], targs[i])
}
}
gf := nameNode.Func
// Pos of the instantiated function is same as the generic function
newf := ir.NewFunc(gf.Pos())
@ -860,6 +887,7 @@ func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, targs []*type
// depend on ir.CurFunc being set.
ir.CurFunc = newf
assert(len(tparams) == len(shapes))
assert(len(tparams) == len(targs))
subst := &subster{
@ -869,9 +897,26 @@ func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, targs []*type
info: info,
ts: typecheck.Tsubster{
Tparams: tparams,
Targs: shapes,
Vars: make(map[*ir.Name]*ir.Name),
},
shape2param: map[*types.Type]*types.Type{},
unshapify: typecheck.Tsubster{
Tparams: shapes,
Targs: targs,
Vars: make(map[*ir.Name]*ir.Name),
},
concretify: typecheck.Tsubster{
Tparams: tparams,
Targs: targs,
Vars: make(map[*ir.Name]*ir.Name),
},
}
for i := range shapes {
if !shapes[i].IsShape() {
panic("must be a shape type")
}
subst.shape2param[shapes[i]] = tparams[i]
}
newf.Dcl = make([]*ir.Name, 0, len(gf.Dcl)+1)
@ -919,16 +964,25 @@ func (g *irgen) genericSubst(newsym *types.Sym, nameNode *ir.Name, targs []*type
newf.Body = subst.list(gf.Body)
// Add code to check that the dictionary is correct.
newf.Body.Prepend(g.checkDictionary(dictionaryName, targs)...)
// TODO: must go away when we move to many->1 shape to concrete mapping.
newf.Body.Prepend(subst.checkDictionary(dictionaryName, targs)...)
ir.CurFunc = savef
// Add any new, fully instantiated types seen during the substitution to
// g.instTypeList.
g.instTypeList = append(g.instTypeList, subst.ts.InstTypeList...)
g.instTypeList = append(g.instTypeList, subst.unshapify.InstTypeList...)
g.instTypeList = append(g.instTypeList, subst.concretify.InstTypeList...)
return newf
}
func (subst *subster) unshapifyTyp(t *types.Type) *types.Type {
res := subst.unshapify.Typ(t)
types.CheckSize(res)
return res
}
// localvar creates a new name node for the specified local variable and enters it
// in subst.vars. It substitutes type arguments for type parameters in the type of
// name as needed.
@ -950,7 +1004,7 @@ func (subst *subster) localvar(name *ir.Name) *ir.Name {
// checkDictionary returns code that does runtime consistency checks
// between the dictionary and the types it should contain.
func (g *irgen) checkDictionary(name *ir.Name, targs []*types.Type) (code []ir.Node) {
func (subst *subster) checkDictionary(name *ir.Name, targs []*types.Type) (code []ir.Node) {
if false {
return // checking turned off
}
@ -965,6 +1019,13 @@ func (g *irgen) checkDictionary(name *ir.Name, targs []*types.Type) (code []ir.N
// Check that each type entry in the dictionary is correct.
for i, t := range targs {
if t.HasShape() {
// Check the concrete type, not the shape type.
// TODO: can this happen?
//t = subst.unshapify.Typ(t)
base.Fatalf("shape type in dictionary %s %+v\n", name.Sym().Name, t)
continue
}
want := reflectdata.TypePtr(t)
typed(types.Types[types.TUINTPTR], want)
deref := ir.NewStarExpr(pos, d)
@ -1144,11 +1205,36 @@ func (subst *subster) node(n ir.Node) ir.Node {
// will be transformed to an ODOTMETH or ODOTINTER node if
// we find in the OCALL case below that the method value
// is actually called.
transformDot(m.(*ir.SelectorExpr), false)
mse := m.(*ir.SelectorExpr)
if src := mse.X.Type(); src.IsShape() {
// The only dot on a shape type value are methods.
if mse.X.Op() == ir.OTYPE {
// Method expression T.M
// Fall back from shape type to concrete type.
src = subst.unshapifyTyp(src)
mse.X = ir.TypeNode(src)
} else {
// Implement x.M as a conversion-to-bound-interface
// 1) convert x to the bound interface
// 2) call M on that interface
dst := subst.concretify.Typ(subst.shape2param[src].Bound())
// Mark that we use the methods of this concrete type.
// Otherwise the linker deadcode-eliminates them :(
reflectdata.MarkTypeUsedInInterface(subst.unshapifyTyp(src), subst.newf.Sym().Linksym())
ix := subst.findDictType(subst.shape2param[src])
assert(ix >= 0)
mse.X = subst.convertUsingDictionary(m.Pos(), mse.X, dst, subst.shape2param[src], ix)
}
}
transformDot(mse, false)
if mse.Op() == ir.OMETHEXPR && mse.X.Type().HasShape() {
mse.X = ir.TypeNodeAt(mse.X.Pos(), subst.unshapifyTyp(mse.X.Type()))
}
m.SetTypecheck(1)
case ir.OCALL:
call := m.(*ir.CallExpr)
convcheck := false
switch call.X.Op() {
case ir.OTYPE:
// Transform the conversion, now that we know the
@ -1170,7 +1256,9 @@ func (subst *subster) node(n ir.Node) ir.Node {
// transform the call.
call.X.(*ir.SelectorExpr).SetOp(ir.OXDOT)
transformDot(call.X.(*ir.SelectorExpr), true)
call.X.SetType(subst.unshapifyTyp(call.X.Type()))
transformCall(call)
convcheck = true
case ir.ODOT, ir.ODOTPTR:
// An OXDOT for a generic receiver was resolved to
@ -1178,6 +1266,7 @@ func (subst *subster) node(n ir.Node) ir.Node {
// value. Transform the call to that function, now
// that the OXDOT was resolved.
transformCall(call)
convcheck = true
case ir.ONAME:
name := call.X.Name()
@ -1190,15 +1279,24 @@ func (subst *subster) node(n ir.Node) ir.Node {
default:
base.FatalfAt(call.Pos(), "Unexpected builtin op")
}
switch m.Op() {
case ir.OAPPEND:
// Append needs to pass a concrete type to the runtime.
// TODO: there's no way to record a dictionary-loaded type for walk to use here
m.SetType(subst.unshapifyTyp(m.Type()))
}
} else {
// This is the case of a function value that was a
// type parameter (implied to be a function via a
// structural constraint) which is now resolved.
transformCall(call)
convcheck = true
}
case ir.OCLOSURE:
transformCall(call)
convcheck = true
case ir.OFUNCINST:
// A call with an OFUNCINST will get transformed
@ -1208,6 +1306,16 @@ func (subst *subster) node(n ir.Node) ir.Node {
default:
base.FatalfAt(call.Pos(), fmt.Sprintf("Unexpected op with CALL during stenciling: %v", call.X.Op()))
}
if convcheck {
for i, arg := range x.(*ir.CallExpr).Args {
if arg.Type().HasTParam() && arg.Op() != ir.OCONVIFACE &&
call.Args[i].Op() == ir.OCONVIFACE {
ix := subst.findDictType(arg.Type())
assert(ix >= 0)
call.Args[i] = subst.convertUsingDictionary(arg.Pos(), call.Args[i].(*ir.ConvExpr).X, call.Args[i].Type(), arg.Type(), ix)
}
}
}
case ir.OCLOSURE:
// We're going to create a new closure from scratch, so clear m
@ -1281,6 +1389,29 @@ func (subst *subster) node(n ir.Node) ir.Node {
m.Y = subst.convertUsingDictionary(m.Y.Pos(), m.Y, i, x.X.Type(), ix)
}
}
case ir.ONEW:
// New needs to pass a concrete type to the runtime.
// Or maybe it doesn't? We could use a shape type.
// TODO: need to modify m.X? I don't think any downstream passes use it.
m.SetType(subst.unshapifyTyp(m.Type()))
case ir.OPTRLIT:
m := m.(*ir.AddrExpr)
// Walk uses the type of the argument of ptrlit. Also could be a shape type?
m.X.SetType(subst.unshapifyTyp(m.X.Type()))
case ir.OMETHEXPR:
se := m.(*ir.SelectorExpr)
se.X = ir.TypeNodeAt(se.X.Pos(), subst.unshapifyTyp(se.X.Type()))
case ir.OFUNCINST:
inst := m.(*ir.InstExpr)
targs2 := make([]ir.Node, len(inst.Targs))
for i, n := range inst.Targs {
targs2[i] = ir.TypeNodeAt(n.Pos(), subst.unshapifyTyp(n.Type()))
// TODO: need an ir.Name node?
}
inst.Targs = targs2
}
return m
}
@ -1414,6 +1545,13 @@ func (g *irgen) getDictionarySym(gf *ir.Name, targs []*types.Type, isMeth bool)
base.Fatalf("%s should have type arguments", gf.Sym().Name)
}
// Enforce that only concrete types can make it to here.
for _, t := range targs {
if t.IsShape() {
panic(fmt.Sprintf("shape %+v in dictionary for %s", t, gf.Sym().Name))
}
}
// Get a symbol representing the dictionary.
sym := typecheck.MakeDictName(gf.Sym(), targs, isMeth)

2
src/cmd/compile/internal/noder/types.go
View file

@ -327,7 +327,7 @@ func (g *irgen) fillinMethods(typ *types2.Named, ntyp *types.Type) {
methods[i].Nname = meth
}
ntyp.Methods().Set(methods)
if !ntyp.HasTParam() {
if !ntyp.HasTParam() && !ntyp.HasShape() {
// Generate all the methods for a new fully-instantiated type.
g.instTypeList = append(g.instTypeList, ntyp)
}

33
src/cmd/compile/internal/reflectdata/reflect.go
View file

@ -302,6 +302,9 @@ func MapIterType(t *types.Type) *types.Type {
// methods returns the methods of the non-interface type t, sorted by name.
// Generates stub functions as needed.
func methods(t *types.Type) []*typeSig {
if t.HasShape() {
return nil
}
// method type
mt := types.ReceiverBaseType(t)
@ -1215,6 +1218,7 @@ func NeedRuntimeType(t *types.Type) {
if t.HasTParam() {
// Generic types don't have a runtime type descriptor (but will
// have a dictionary)
// TODO: also shape type here?
return
}
if _, ok := signatset[t]; !ok {
@ -1276,6 +1280,9 @@ func writeITab(lsym *obj.LSym, typ, iface *types.Type) {
for _, m := range methods(typ) {
if m.name == sigs[0].Sym {
entries = append(entries, m.isym)
if m.isym == nil {
panic("NO ISYM")
}
sigs = sigs[1:]
if len(sigs) == 0 {
break
@ -1764,6 +1771,17 @@ func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSy
// an embedded field) which is an interface method.
// TODO: check that we do the right thing when method is an interface method.
generic = true
targs := rcvr.RParams()
if rcvr.IsPtr() {
targs = rcvr.Elem().RParams()
}
// TODO: why do shape-instantiated types exist?
for _, t := range targs {
if t.HasShape() {
base.Fatalf("method on type instantiated with shapes targ:%+v rcvr:%+v", t, rcvr)
}
}
}
newnam := ir.MethodSym(rcvr, method.Sym)
lsym := newnam.Linksym()
@ -1881,9 +1899,13 @@ func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSy
}
args = append(args, ir.ParamNames(tfn.Type())...)
// TODO: Once we enter the gcshape world, we'll need a way to look up
// the stenciled implementation to use for this concrete type. Essentially,
// erase the concrete types and replace them with gc shape representatives.
// Target method uses shaped names.
targs2 := make([]*types.Type, len(targs))
for i, t := range targs {
targs2[i] = typecheck.Shaped[t]
}
targs = targs2
sym := typecheck.MakeInstName(ir.MethodSym(methodrcvr, method.Sym), targs, true)
if sym.Def == nil {
// Currently we make sure that we have all the instantiations
@ -1975,6 +1997,11 @@ func getDictionary(gf *types.Sym, targs []*types.Type) ir.Node {
if len(targs) == 0 {
base.Fatalf("%s should have type arguments", gf.Name)
}
for _, t := range targs {
if t.HasShape() {
base.Fatalf("dictionary for %s should only use concrete types: %+v", gf.Name, t)
}
}
sym := typecheck.MakeDictName(gf, targs, true)

104
src/cmd/compile/internal/typecheck/subr.go
View file

@ -353,9 +353,10 @@ func Assignop(src, dst *types.Type) (ir.Op, string) {
return ir.OCONVNOP, ""
}
// 2. src and dst have identical underlying types
// and either src or dst is not a named type or
// both are empty interface types.
// 2. src and dst have identical underlying types and
// a. either src or dst is not a named type, or
// b. both are empty interface types, or
// c. at least one is a gcshape type.
// For assignable but different non-empty interface types,
// we want to recompute the itab. Recomputing the itab ensures
// that itabs are unique (thus an interface with a compile-time
@ -372,12 +373,23 @@ func Assignop(src, dst *types.Type) (ir.Op, string) {
// which need to have their itab updated.
return ir.OCONVNOP, ""
}
if src.IsShape() || dst.IsShape() {
// Conversion between a shape type and one of the types
// it represents also needs no conversion.
return ir.OCONVNOP, ""
}
}
// 3. dst is an interface type and src implements dst.
if dst.IsInterface() && src.Kind() != types.TNIL {
var missing, have *types.Field
var ptr int
if src.IsShape() {
// Shape types implement things they have already
// been typechecked to implement, even if they
// don't have the methods for them.
return ir.OCONVIFACE, ""
}
if implements(src, dst, &missing, &have, &ptr) {
return ir.OCONVIFACE, ""
}
@ -898,8 +910,8 @@ func makeGenericName(name string, targs []*types.Type, hasBrackets bool) string
hasTParam := false
for _, targ := range targs {
if hasTParam {
assert(targ.HasTParam())
} else if targ.HasTParam() {
assert(targ.HasTParam() || targ.HasShape())
} else if targ.HasTParam() || targ.HasShape() {
hasTParam = true
}
}
@ -1002,14 +1014,14 @@ type Tsubster struct {
// result is t; otherwise the result is a new type. It deals with recursive types
// by using TFORW types and finding partially or fully created types via sym.Def.
func (ts *Tsubster) Typ(t *types.Type) *types.Type {
if !t.HasTParam() && t.Kind() != types.TFUNC {
if !t.HasTParam() && !t.HasShape() && t.Kind() != types.TFUNC {
// Note: function types need to be copied regardless, as the
// types of closures may contain declarations that need
// to be copied. See #45738.
return t
}
if t.IsTypeParam() {
if t.IsTypeParam() || t.IsShape() {
for i, tp := range ts.Tparams {
if tp == t {
return ts.Targs[i]
@ -1038,6 +1050,7 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
var newsym *types.Sym
var neededTargs []*types.Type
var targsChanged bool
var forw *types.Type
if t.Sym() != nil {
@ -1046,6 +1059,9 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
neededTargs = make([]*types.Type, len(t.RParams()))
for i, rparam := range t.RParams() {
neededTargs[i] = ts.Typ(rparam)
if !types.Identical(neededTargs[i], rparam) {
targsChanged = true
}
}
// For a named (defined) type, we have to change the name of the
// type as well. We do this first, so we can look up if we've
@ -1074,7 +1090,7 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
switch t.Kind() {
case types.TTYPEPARAM:
if t.Sym() == newsym {
if t.Sym() == newsym && !targsChanged {
// The substitution did not change the type.
return t
}
@ -1086,26 +1102,26 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
case types.TARRAY:
elem := t.Elem()
newelem := ts.Typ(elem)
if newelem != elem {
if newelem != elem || targsChanged {
newt = types.NewArray(newelem, t.NumElem())
}
case types.TPTR:
elem := t.Elem()
newelem := ts.Typ(elem)
if newelem != elem {
if newelem != elem || targsChanged {
newt = types.NewPtr(newelem)
}
case types.TSLICE:
elem := t.Elem()
newelem := ts.Typ(elem)
if newelem != elem {
if newelem != elem || targsChanged {
newt = types.NewSlice(newelem)
}
case types.TSTRUCT:
newt = ts.tstruct(t, false)
newt = ts.tstruct(t, targsChanged)
if newt == t {
newt = nil
}
@ -1114,7 +1130,7 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
newrecvs := ts.tstruct(t.Recvs(), false)
newparams := ts.tstruct(t.Params(), false)
newresults := ts.tstruct(t.Results(), false)
if newrecvs != t.Recvs() || newparams != t.Params() || newresults != t.Results() {
if newrecvs != t.Recvs() || newparams != t.Params() || newresults != t.Results() || targsChanged {
// If any types have changed, then the all the fields of
// of recv, params, and results must be copied, because they have
// offset fields that are dependent, and so must have an
@ -1144,14 +1160,14 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
case types.TMAP:
newkey := ts.Typ(t.Key())
newval := ts.Typ(t.Elem())
if newkey != t.Key() || newval != t.Elem() {
if newkey != t.Key() || newval != t.Elem() || targsChanged {
newt = types.NewMap(newkey, newval)
}
case types.TCHAN:
elem := t.Elem()
newelem := ts.Typ(elem)
if newelem != elem {
if newelem != elem || targsChanged {
newt = types.NewChan(newelem, t.ChanDir())
if !newt.HasTParam() {
// TODO(danscales): not sure why I have to do this
@ -1167,7 +1183,7 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
}
case types.TINT, types.TINT8, types.TINT16, types.TINT32, types.TINT64,
types.TUINT, types.TUINT8, types.TUINT16, types.TUINT32, types.TUINT64,
types.TUINTPTR, types.TBOOL, types.TSTRING:
types.TUINTPTR, types.TBOOL, types.TSTRING, types.TFLOAT32, types.TFLOAT64, types.TCOMPLEX64, types.TCOMPLEX128:
newt = t.Underlying()
}
if newt == nil {
@ -1177,15 +1193,17 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
return t
}
if t.Sym() == nil {
// Not a named type, so there was no forwarding type and there are
// no methods to substitute.
if t.Sym() == nil && t.Kind() != types.TINTER {
// Not a named type or interface type, so there was no forwarding type
// and there are no methods to substitute.
assert(t.Methods().Len() == 0)
return newt
}
forw.SetUnderlying(newt)
newt = forw
if forw != nil {
forw.SetUnderlying(newt)
newt = forw
}
if t.Kind() != types.TINTER && t.Methods().Len() > 0 {
// Fill in the method info for the new type.
@ -1207,7 +1225,7 @@ func (ts *Tsubster) Typ(t *types.Type) *types.Type {
newfields[i].Nname = nname
}
newt.Methods().Set(newfields)
if !newt.HasTParam() {
if !newt.HasTParam() && !newt.HasShape() {
// Generate all the methods for a new fully-instantiated type.
ts.InstTypeList = append(ts.InstTypeList, newt)
}
@ -1305,3 +1323,45 @@ func (ts *Tsubster) tinter(t *types.Type) *types.Type {
func genericTypeName(sym *types.Sym) string {
return sym.Name[0:strings.Index(sym.Name, "[")]
}
// Shapify takes a concrete type and returns a GCshape type that can
// be used in place of the input type and still generate identical code.
// TODO: this could take the generic function and base its decisions
// on how that generic function uses this type argument. For instance,
// if it doesn't use it as a function argument/return value, then
// we don't need to distinguish int64 and float64 (because they only
// differ in how they get passed as arguments). For now, we only
// unify two different types if they are identical in every possible way.
func Shapify(t *types.Type) *types.Type {
if t.IsShape() {
return t // TODO: is this right?
}
if s := Shaped[t]; s != nil {
return s //TODO: keep?
}
// For now, there is a 1-1 mapping between regular types and shape types.
sym := Lookup(fmt.Sprintf(".shape%d", snum))
snum++
name := ir.NewDeclNameAt(t.Pos(), ir.OTYPE, sym)
s := types.NewNamed(name)
s.SetUnderlying(t.Underlying())
s.SetIsShape(true)
name.SetType(s)
name.SetTypecheck(1)
// TODO: add methods to s that the bound has?
Shaped[t] = s
return s
}
var snum int
var Shaped = map[*types.Type]*types.Type{}
func ShapifyList(targs []*types.Type) []*types.Type {
r := make([]*types.Type, len(targs))
for i, t := range targs {
r[i] = Shapify(t)
}
return r
}

9
src/cmd/compile/internal/types/identity.go
View file

@ -29,6 +29,14 @@ func identical(t1, t2 *Type, cmpTags bool, assumedEqual map[typePair]struct{}) b
return false
}
if t1.sym != nil || t2.sym != nil {
if t1.HasShape() || t2.HasShape() {
switch t1.kind {
case TINT8, TUINT8, TINT16, TUINT16, TINT32, TUINT32, TINT64, TUINT64, TINT, TUINT, TUINTPTR, TCOMPLEX64, TCOMPLEX128, TFLOAT32, TFLOAT64, TBOOL, TSTRING, TUNSAFEPTR:
return true
}
// fall through to unnamed type comparison for complex types.
goto cont
}
// Special case: we keep byte/uint8 and rune/int32
// separate for error messages. Treat them as equal.
switch t1.kind {
@ -40,6 +48,7 @@ func identical(t1, t2 *Type, cmpTags bool, assumedEqual map[typePair]struct{}) b
return false
}
}
cont:
// Any cyclic type must go through a named type, and if one is
// named, it is only identical to the other if they are the

46
src/cmd/compile/internal/types/type.go
View file

@ -210,6 +210,7 @@ const (
typeDeferwidth // width computation has been deferred and type is on deferredTypeStack
typeRecur
typeHasTParam // there is a typeparam somewhere in the type (generic function or type)
typeIsShape // represents a set of closely related types, for generics
)
func (t *Type) NotInHeap() bool { return t.flags&typeNotInHeap != 0 }
@ -218,12 +219,14 @@ func (t *Type) Noalg() bool { return t.flags&typeNoalg != 0 }
func (t *Type) Deferwidth() bool { return t.flags&typeDeferwidth != 0 }
func (t *Type) Recur() bool { return t.flags&typeRecur != 0 }
func (t *Type) HasTParam() bool { return t.flags&typeHasTParam != 0 }
func (t *Type) IsShape() bool { return t.flags&typeIsShape != 0 }
func (t *Type) SetNotInHeap(b bool) { t.flags.set(typeNotInHeap, b) }
func (t *Type) SetBroke(b bool) { t.flags.set(typeBroke, b) }
func (t *Type) SetNoalg(b bool) { t.flags.set(typeNoalg, b) }
func (t *Type) SetDeferwidth(b bool) { t.flags.set(typeDeferwidth, b) }
func (t *Type) SetRecur(b bool) { t.flags.set(typeRecur, b) }
func (t *Type) SetIsShape(b bool) { t.flags.set(typeIsShape, b) }
// Generic types should never have alg functions.
func (t *Type) SetHasTParam(b bool) { t.flags.set(typeHasTParam, b); t.flags.set(typeNoalg, b) }
@ -2147,3 +2150,46 @@ var (
)
var SimType [NTYPE]Kind
// Reports whether t has a shape type anywere.
func (t *Type) HasShape() bool {
return t.HasShape1(map[*Type]bool{})
}
func (t *Type) HasShape1(visited map[*Type]bool) bool {
if t.IsShape() {
return true
}
if visited[t] {
return false
}
visited[t] = true
if t.Sym() != nil {
for _, u := range t.RParams() {
if u.HasShape1(visited) {
return true
}
}
}
switch t.Kind() {
case TPTR, TARRAY, TSLICE, TCHAN:
return t.Elem().HasShape1(visited)
case TMAP:
return t.Elem().HasShape1(visited) || t.Key().HasShape1(visited)
case TSTRUCT:
for _, f := range t.FieldSlice() {
if f.Type.HasShape1(visited) {
return true
}
}
case TFUNC:
for _, a := range RecvsParamsResults {
for _, f := range a(t).FieldSlice() {
if f.Type.HasShape1(visited) {
return true
}
}
}
// TODO: TINTER - check methods?
}
return false
}

5
src/cmd/internal/obj/objfile.go
View file

@ -452,6 +452,11 @@ func (w *writer) contentHash(s *LSym) goobj.HashType {
binary.LittleEndian.PutUint64(tmp[6:14], uint64(r.Add))
h.Write(tmp[:])
rs := r.Sym
if rs == nil {
fmt.Printf("symbol: %s\n", s)
fmt.Printf("relocation: %#v\n", r)
panic("nil symbol target in relocation")
}
switch rs.PkgIdx {
case goobj.PkgIdxHashed64:
h.Write([]byte{0})