diff options
| -rw-r--r-- | src/go/types/call.go | 48 | ||||
| -rw-r--r-- | src/go/types/decl.go | 6 | ||||
| -rw-r--r-- | src/go/types/infer.go | 1 | ||||
| -rw-r--r-- | src/go/types/instantiate_test.go | 39 | ||||
| -rw-r--r-- | src/go/types/lookup.go | 24 | ||||
| -rw-r--r-- | src/go/types/named.go | 79 | ||||
| -rw-r--r-- | src/go/types/object.go | 5 | ||||
| -rw-r--r-- | src/go/types/sizeof_test.go | 2 | ||||
| -rw-r--r-- | src/go/types/subst.go | 4 |
9 files changed, 119 insertions, 89 deletions
diff --git a/src/go/types/call.go b/src/go/types/call.go index 4de5fed46e..4d14e31730 100644 --- a/src/go/types/call.go +++ b/src/go/types/call.go @@ -532,54 +532,6 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) { // methods may not have a fully set up signature yet if m, _ := obj.(*Func); m != nil { check.objDecl(m, nil) - // If m has a parameterized receiver type, infer the type arguments from - // the actual receiver provided and then substitute the type parameters in - // the signature accordingly. - // TODO(gri) factor this code out - sig := m.typ.(*Signature) - if sig.RecvTypeParams().Len() > 0 { - // For inference to work, we must use the receiver type - // matching the receiver in the actual method declaration. - // If the method is embedded, the matching receiver is the - // embedded struct or interface that declared the method. - // Traverse the embedding to find that type (issue #44688). - recv := x.typ - for i := 0; i < len(index)-1; i++ { - // The embedded type is either a struct or a pointer to - // a struct except for the last one (which we don't need). - recv = asStruct(derefStructPtr(recv)).Field(index[i]).typ - } - - // The method may have a pointer receiver, but the actually provided receiver - // may be a (hopefully addressable) non-pointer value, or vice versa. Here we - // only care about inferring receiver type parameters; to make the inference - // work, match up pointer-ness of receiver and argument. - if ptrRecv := isPointer(sig.recv.typ); ptrRecv != isPointer(recv) { - if ptrRecv { - recv = NewPointer(recv) - } else { - recv = recv.(*Pointer).base - } - } - // Disable reporting of errors during inference below. If we're unable to infer - // the receiver type arguments here, the receiver must be be otherwise invalid - // and an error has been reported elsewhere. - arg := operand{mode: variable, expr: x.expr, typ: recv} - targs := check.infer(m, sig.RecvTypeParams().list(), nil, NewTuple(sig.recv), []*operand{&arg}, false /* no error reporting */) - if targs == nil { - // We may reach here if there were other errors (see issue #40056). - goto Error - } - // Don't modify m. Instead - for now - make a copy of m and use that instead. - // (If we modify m, some tests will fail; possibly because the m is in use.) - // TODO(gri) investigate and provide a correct explanation here - copy := *m - copy.typ = check.subst(e.Pos(), m.typ, makeSubstMap(sig.RecvTypeParams().list(), targs), nil) - obj = © - } - // TODO(gri) we also need to do substitution for parameterized interface methods - // (this breaks code in testdata/linalg.go2 at the moment) - // 12/20/2019: Is this TODO still correct? } if x.mode == typexpr { diff --git a/src/go/types/decl.go b/src/go/types/decl.go index 7f157f528a..0fdcfa8023 100644 --- a/src/go/types/decl.go +++ b/src/go/types/decl.go @@ -65,6 +65,12 @@ func (check *Checker) objDecl(obj Object, def *Named) { }() } + // Funcs with m.instRecv set have not yet be completed. Complete them now + // so that they have a type when objDecl exits. + if m, _ := obj.(*Func); m != nil && m.instRecv != nil { + check.completeMethod(check.conf.Environment, m) + } + // Checking the declaration of obj means inferring its type // (and possibly its value, for constants). // An object's type (and thus the object) may be in one of diff --git a/src/go/types/infer.go b/src/go/types/infer.go index 7314a614d0..18c5119177 100644 --- a/src/go/types/infer.go +++ b/src/go/types/infer.go @@ -28,6 +28,7 @@ import ( // // Constraint type inference is used after each step to expand the set of type arguments. // +// TODO(rfindley): remove the report parameter: is no longer needed. func (check *Checker) infer(posn positioner, tparams []*TypeParam, targs []Type, params *Tuple, args []*operand, report bool) (result []Type) { if debug { defer func() { diff --git a/src/go/types/instantiate_test.go b/src/go/types/instantiate_test.go index 0b09bfebe3..851800e76d 100644 --- a/src/go/types/instantiate_test.go +++ b/src/go/types/instantiate_test.go @@ -70,3 +70,42 @@ func TestInstantiateNonEquality(t *testing.T) { t.Errorf("instance from pkg1 (%s) is identical to instance from pkg2 (%s)", res1, res2) } } + +func TestMethodInstantiation(t *testing.T) { + const prefix = genericPkg + `p + +type T[P any] struct{} + +var X T[int] + +` + tests := []struct { + decl string + want string + }{ + {"func (r T[P]) m() P", "func (T[int]).m() int"}, + {"func (r T[P]) m(P)", "func (T[int]).m(int)"}, + {"func (r T[P]) m() func() P", "func (T[int]).m() func() int"}, + {"func (r T[P]) m() T[P]", "func (T[int]).m() T[int]"}, + {"func (r T[P]) m(T[P])", "func (T[int]).m(T[int])"}, + {"func (r T[P]) m(T[P], P, string)", "func (T[int]).m(T[int], int, string)"}, + {"func (r T[P]) m(T[P], T[string], T[int])", "func (T[int]).m(T[int], T[string], T[int])"}, + } + + for _, test := range tests { + src := prefix + test.decl + pkg, err := pkgFor(".", src, nil) + if err != nil { + t.Fatal(err) + } + typ := pkg.Scope().Lookup("X").Type().(*Named) + obj, _, _ := LookupFieldOrMethod(typ, false, pkg, "m") + m, _ := obj.(*Func) + if m == nil { + t.Fatalf(`LookupFieldOrMethod(%s, "m") = %v, want func m`, typ, obj) + } + if got := ObjectString(m, RelativeTo(pkg)); got != test.want { + t.Errorf("instantiated %q, want %q", got, test.want) + } + } +} diff --git a/src/go/types/lookup.go b/src/go/types/lookup.go index cc7f24d97b..a270159499 100644 --- a/src/go/types/lookup.go +++ b/src/go/types/lookup.go @@ -6,8 +6,6 @@ package types -import "go/token" - // Internal use of LookupFieldOrMethod: If the obj result is a method // associated with a concrete (non-interface) type, the method's signature // may not be fully set up. Call Checker.objDecl(obj, nil) before accessing @@ -342,8 +340,6 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method, } // A concrete type implements T if it implements all methods of T. - Vd, _ := deref(V) - Vn := asNamed(Vd) for _, m := range T.typeSet().methods { // TODO(gri) should this be calling lookupFieldOrMethod instead (and why not)? obj, _, _ := lookupFieldOrMethod(V, false, m.pkg, m.name) @@ -378,26 +374,6 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method, panic("method with type parameters") } - // If V is a (instantiated) generic type, its methods are still - // parameterized using the original (declaration) receiver type - // parameters (subst simply copies the existing method list, it - // does not instantiate the methods). - // In order to compare the signatures, substitute the receiver - // type parameters of ftyp with V's instantiation type arguments. - // This lazily instantiates the signature of method f. - if Vn != nil && Vn.TypeParams().Len() > 0 { - // Be careful: The number of type arguments may not match - // the number of receiver parameters. If so, an error was - // reported earlier but the length discrepancy is still - // here. Exit early in this case to prevent an assertion - // failure in makeSubstMap. - // TODO(gri) Can we avoid this check by fixing the lengths? - if len(ftyp.RecvTypeParams().list()) != Vn.targs.Len() { - return - } - ftyp = check.subst(token.NoPos, ftyp, makeSubstMap(ftyp.RecvTypeParams().list(), Vn.targs.list()), nil).(*Signature) - } - // If the methods have type parameters we don't care whether they // are the same or not, as long as they match up. Use unification // to see if they can be made to match. diff --git a/src/go/types/named.go b/src/go/types/named.go index 943d52f0fe..66ae012379 100644 --- a/src/go/types/named.go +++ b/src/go/types/named.go @@ -221,16 +221,17 @@ func (n *Named) setUnderlying(typ Type) { // expandNamed ensures that the underlying type of n is instantiated. // The underlying type will be Typ[Invalid] if there was an error. -func expandNamed(env *Environment, n *Named, instPos token.Pos) (*TypeParamList, Type, []*Func) { +func expandNamed(env *Environment, n *Named, instPos token.Pos) (tparams *TypeParamList, underlying Type, methods []*Func) { n.orig.resolve(env) - var u Type - if n.check.validateTArgLen(instPos, n.orig.tparams.Len(), n.targs.Len()) { + check := n.check + + if check.validateTArgLen(instPos, n.orig.tparams.Len(), n.targs.Len()) { // TODO(rfindley): handling an optional Checker and Environment here (and // in subst) feels overly complicated. Can we simplify? if env == nil { - if n.check != nil { - env = n.check.conf.Environment + if check != nil { + env = check.conf.Environment } else { // If we're instantiating lazily, we might be outside the scope of a // type-checking pass. In that case we won't have a pre-existing @@ -239,16 +240,72 @@ func expandNamed(env *Environment, n *Named, instPos token.Pos) (*TypeParamList, env = NewEnvironment() } h := env.typeHash(n.orig, n.targs.list()) - // add the instance to the environment to avoid infinite recursion. - // addInstance may return a different, existing instance, but we - // shouldn't return that instance from expand. + // ensure that an instance is recorded for h to avoid infinite recursion. env.typeForHash(h, n) } - u = n.check.subst(instPos, n.orig.underlying, makeSubstMap(n.orig.tparams.list(), n.targs.list()), env) + smap := makeSubstMap(n.orig.tparams.list(), n.targs.list()) + underlying = n.check.subst(instPos, n.orig.underlying, smap, env) + for i := 0; i < n.orig.NumMethods(); i++ { + origm := n.orig.Method(i) + + // During type checking origm may not have a fully set up type, so defer + // instantiation of its signature until later. + m := NewFunc(origm.pos, origm.pkg, origm.name, nil) + m.hasPtrRecv = origm.hasPtrRecv + // Setting instRecv here allows us to complete later (we need the + // instRecv to get targs and the original method). + m.instRecv = n + + methods = append(methods, m) + } + } else { + underlying = Typ[Invalid] + } + + // Methods should not escape the type checker API without being completed. If + // we're in the context of a type checking pass, we need to defer this until + // later (not all methods may have types). + completeMethods := func() { + for _, m := range methods { + if m.instRecv != nil { + check.completeMethod(env, m) + } + } + } + if check != nil { + check.later(completeMethods) } else { - u = Typ[Invalid] + completeMethods() } - return n.orig.tparams, u, n.orig.methods + + return n.orig.tparams, underlying, methods +} + +func (check *Checker) completeMethod(env *Environment, m *Func) { + assert(m.instRecv != nil) + rtyp := m.instRecv + m.instRecv = nil + m.setColor(black) + + assert(rtyp.TypeArgs().Len() > 0) + + // Look up the original method. + _, orig := lookupMethod(rtyp.orig.methods, rtyp.obj.pkg, m.name) + assert(orig != nil) + if check != nil { + check.objDecl(orig, nil) + } + origSig := orig.typ.(*Signature) + if origSig.RecvTypeParams().Len() != rtyp.targs.Len() { + m.typ = origSig // or new(Signature), but we can't use Typ[Invalid]: Funcs must have Signature type + return // error reported elsewhere + } + + smap := makeSubstMap(origSig.RecvTypeParams().list(), rtyp.targs.list()) + sig := check.subst(orig.pos, origSig, smap, env).(*Signature) + sig.recv = NewParam(origSig.recv.pos, origSig.recv.pkg, origSig.recv.name, rtyp) + + m.typ = sig } // safeUnderlying returns the underlying of typ without expanding instances, to diff --git a/src/go/types/object.go b/src/go/types/object.go index 7f6f8a2550..454b714458 100644 --- a/src/go/types/object.go +++ b/src/go/types/object.go @@ -317,7 +317,8 @@ func (*Var) isDependency() {} // a variable may be a dependency of an initializa // An abstract method may belong to many interfaces due to embedding. type Func struct { object - hasPtrRecv bool // only valid for methods that don't have a type yet + instRecv *Named // if non-nil, the receiver type for an incomplete instance method + hasPtrRecv bool // only valid for methods that don't have a type yet } // NewFunc returns a new function with the given signature, representing @@ -328,7 +329,7 @@ func NewFunc(pos token.Pos, pkg *Package, name string, sig *Signature) *Func { if sig != nil { typ = sig } - return &Func{object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}, false} + return &Func{object{nil, pos, pkg, name, typ, 0, colorFor(typ), token.NoPos}, nil, false} } // FullName returns the package- or receiver-type-qualified name of diff --git a/src/go/types/sizeof_test.go b/src/go/types/sizeof_test.go index f418e037a9..0e3c0064a0 100644 --- a/src/go/types/sizeof_test.go +++ b/src/go/types/sizeof_test.go @@ -40,7 +40,7 @@ func TestSizeof(t *testing.T) { {Const{}, 48, 88}, {TypeName{}, 40, 72}, {Var{}, 44, 80}, - {Func{}, 44, 80}, + {Func{}, 48, 88}, {Label{}, 44, 80}, {Builtin{}, 44, 80}, {Nil{}, 40, 72}, diff --git a/src/go/types/subst.go b/src/go/types/subst.go index a063dd0a07..3491541dcb 100644 --- a/src/go/types/subst.go +++ b/src/go/types/subst.go @@ -70,7 +70,6 @@ func (check *Checker) subst(pos token.Pos, typ Type, smap substMap, env *Environ env = NewEnvironment() } subst.env = env - return subst.typ(typ) } @@ -125,8 +124,7 @@ func (subst *subster) typ(typ Type) Type { if recv != t.recv || params != t.params || results != t.results { return &Signature{ rparams: t.rparams, - // TODO(rFindley) why can't we nil out tparams here, rather than in - // instantiate above? + // TODO(rFindley) why can't we nil out tparams here, rather than in instantiate? tparams: t.tparams, scope: t.scope, recv: recv, |