diff options
| -rw-r--r-- | src/cmd/compile/internal/types2/signature.go | 32 | ||||
| -rw-r--r-- | src/cmd/compile/internal/types2/testdata/examples/methods.go2 | 17 |
2 files changed, 37 insertions, 12 deletions
diff --git a/src/cmd/compile/internal/types2/signature.go b/src/cmd/compile/internal/types2/signature.go index ab9a1c487e..fa5c3f7a9b 100644 --- a/src/cmd/compile/internal/types2/signature.go +++ b/src/cmd/compile/internal/types2/signature.go @@ -211,9 +211,10 @@ func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams [] // spec: "The receiver type must be of the form T or *T where T is a type name." // (ignore invalid types - error was reported before) - if t := rtyp; t != Typ[Invalid] { + if rtyp != Typ[Invalid] { var err string - if T := asNamed(t); T != nil { + switch T := rtyp.(type) { + case *Named: // spec: "The type denoted by T is called the receiver base type; it must not // be a pointer or interface type and it must be declared in the same package // as the method." @@ -224,23 +225,30 @@ func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams [] err = "" } } else { - switch u := optype(T).(type) { - case *Basic: - // unsafe.Pointer is treated like a regular pointer - if u.kind == UnsafePointer { - err = "unsafe.Pointer" + // The underlying type of a receiver base type can be a type parameter; + // e.g. for methods with a generic receiver T[P] with type T[P any] P. + underIs(T, func(u Type) bool { + switch u := u.(type) { + case *Basic: + // unsafe.Pointer is treated like a regular pointer + if u.kind == UnsafePointer { + err = "unsafe.Pointer" + return false + } + case *Pointer, *Interface: + err = "pointer or interface type" + return false } - case *Pointer, *Interface: - err = "pointer or interface type" - } + return true + }) } - } else if T := asBasic(t); T != nil { + case *Basic: err = "basic or unnamed type" if check.conf.CompilerErrorMessages { check.errorf(recv.pos, "cannot define new methods on non-local type %s", recv.typ) err = "" } - } else { + default: check.errorf(recv.pos, "invalid receiver type %s", recv.typ) } if err != "" { diff --git a/src/cmd/compile/internal/types2/testdata/examples/methods.go2 b/src/cmd/compile/internal/types2/testdata/examples/methods.go2 index 76c6539e1b..4e87041e54 100644 --- a/src/cmd/compile/internal/types2/testdata/examples/methods.go2 +++ b/src/cmd/compile/internal/types2/testdata/examples/methods.go2 @@ -6,6 +6,8 @@ package p +import "unsafe" + // Parameterized types may have methods. type T1[A any] struct{ a A } @@ -94,3 +96,18 @@ func (_ T2[_, _, _]) _() int { return 42 } type T0 struct{} func (T0) _() {} func (T1[A]) _() {} + +// A generic receiver type may constrain its type parameter such +// that it must be a pointer type. Such receiver types are not +// permitted. +type T3a[P interface{ ~int | ~string | ~float64 }] P + +func (T3a[_]) m() {} // this is ok + +type T3b[P interface{ ~unsafe.Pointer }] P + +func (T3b /* ERROR invalid receiver */ [_]) m() {} + +type T3c[P interface{ *int | *string }] P + +func (T3c /* ERROR invalid receiver */ [_]) m() {} |