Merge pull request #966 from visualfc/reflect_go123

runtime: fix reflect type for go1.23

_demo/reflectfunc/reflectfunc.go

@@ -22,8 +22,7 @@ func main() {
 			println("closure", i)
 		}
 	}
-	// TODO(lijie): WORKAROUND for reflect problem on go1.23
+
-	_ = any(reflect.Value{})
 	fns := []any{add, fn, fn1, fn2}
 	for _, fn := range fns {
 		v := reflect.ValueOf(fn)

runtime/internal/lib/reflect/type.go

@@ -30,203 +30,6 @@ import (
 	"github.com/goplus/llgo/runtime/internal/runtime/goarch"
 )
 
-// Type is the representation of a Go type.
-//
-// Not all methods apply to all kinds of types. Restrictions,
-// if any, are noted in the documentation for each method.
-// Use the Kind method to find out the kind of type before
-// calling kind-specific methods. Calling a method
-// inappropriate to the kind of type causes a run-time panic.
-//
-// Type values are comparable, such as with the == operator,
-// so they can be used as map keys.
-// Two Type values are equal if they represent identical types.
-type Type interface {
-	// Methods applicable to all types.
-
-	// Align returns the alignment in bytes of a value of
-	// this type when allocated in memory.
-	Align() int
-
-	// FieldAlign returns the alignment in bytes of a value of
-	// this type when used as a field in a struct.
-	FieldAlign() int
-
-	// Method returns the i'th method in the type's method set.
-	// It panics if i is not in the range [0, NumMethod()).
-	//
-	// For a non-interface type T or *T, the returned Method's Type and Func
-	// fields describe a function whose first argument is the receiver,
-	// and only exported methods are accessible.
-	//
-	// For an interface type, the returned Method's Type field gives the
-	// method signature, without a receiver, and the Func field is nil.
-	//
-	// Methods are sorted in lexicographic order.
-	Method(int) Method
-
-	// MethodByName returns the method with that name in the type's
-	// method set and a boolean indicating if the method was found.
-	//
-	// For a non-interface type T or *T, the returned Method's Type and Func
-	// fields describe a function whose first argument is the receiver.
-	//
-	// For an interface type, the returned Method's Type field gives the
-	// method signature, without a receiver, and the Func field is nil.
-	MethodByName(string) (Method, bool)
-
-	// NumMethod returns the number of methods accessible using Method.
-	//
-	// For a non-interface type, it returns the number of exported methods.
-	//
-	// For an interface type, it returns the number of exported and unexported methods.
-	NumMethod() int
-
-	// Name returns the type's name within its package for a defined type.
-	// For other (non-defined) types it returns the empty string.
-	Name() string
-
-	// PkgPath returns a defined type's package path, that is, the import path
-	// that uniquely identifies the package, such as "encoding/base64".
-	// If the type was predeclared (string, error) or not defined (*T, struct{},
-	// []int, or A where A is an alias for a non-defined type), the package path
-	// will be the empty string.
-	PkgPath() string
-
-	// Size returns the number of bytes needed to store
-	// a value of the given type; it is analogous to unsafe.Sizeof.
-	Size() uintptr
-
-	// String returns a string representation of the type.
-	// The string representation may use shortened package names
-	// (e.g., base64 instead of "encoding/base64") and is not
-	// guaranteed to be unique among types. To test for type identity,
-	// compare the Types directly.
-	String() string
-
-	// Kind returns the specific kind of this type.
-	Kind() Kind
-
-	// Implements reports whether the type implements the interface type u.
-	Implements(u Type) bool
-
-	// AssignableTo reports whether a value of the type is assignable to type u.
-	AssignableTo(u Type) bool
-
-	// ConvertibleTo reports whether a value of the type is convertible to type u.
-	// Even if ConvertibleTo returns true, the conversion may still panic.
-	// For example, a slice of type []T is convertible to *[N]T,
-	// but the conversion will panic if its length is less than N.
-	ConvertibleTo(u Type) bool
-
-	// Comparable reports whether values of this type are comparable.
-	// Even if Comparable returns true, the comparison may still panic.
-	// For example, values of interface type are comparable,
-	// but the comparison will panic if their dynamic type is not comparable.
-	Comparable() bool
-
-	// Methods applicable only to some types, depending on Kind.
-	// The methods allowed for each kind are:
-	//
-	//	Int*, Uint*, Float*, Complex*: Bits
-	//	Array: Elem, Len
-	//	Chan: ChanDir, Elem
-	//	Func: In, NumIn, Out, NumOut, IsVariadic.
-	//	Map: Key, Elem
-	//	Pointer: Elem
-	//	Slice: Elem
-	//	Struct: Field, FieldByIndex, FieldByName, FieldByNameFunc, NumField
-
-	// Bits returns the size of the type in bits.
-	// It panics if the type's Kind is not one of the
-	// sized or unsized Int, Uint, Float, or Complex kinds.
-	Bits() int
-
-	// ChanDir returns a channel type's direction.
-	// It panics if the type's Kind is not Chan.
-	ChanDir() ChanDir
-
-	// IsVariadic reports whether a function type's final input parameter
-	// is a "..." parameter. If so, t.In(t.NumIn() - 1) returns the parameter's
-	// implicit actual type []T.
-	//
-	// For concreteness, if t represents func(x int, y ... float64), then
-	//
-	//	t.NumIn() == 2
-	//	t.In(0) is the reflect.Type for "int"
-	//	t.In(1) is the reflect.Type for "[]float64"
-	//	t.IsVariadic() == true
-	//
-	// IsVariadic panics if the type's Kind is not Func.
-	IsVariadic() bool
-
-	// Elem returns a type's element type.
-	// It panics if the type's Kind is not Array, Chan, Map, Pointer, or Slice.
-	Elem() Type
-
-	// Field returns a struct type's i'th field.
-	// It panics if the type's Kind is not Struct.
-	// It panics if i is not in the range [0, NumField()).
-	Field(i int) StructField
-
-	// FieldByIndex returns the nested field corresponding
-	// to the index sequence. It is equivalent to calling Field
-	// successively for each index i.
-	// It panics if the type's Kind is not Struct.
-	FieldByIndex(index []int) StructField
-
-	// FieldByName returns the struct field with the given name
-	// and a boolean indicating if the field was found.
-	FieldByName(name string) (StructField, bool)
-
-	// FieldByNameFunc returns the struct field with a name
-	// that satisfies the match function and a boolean indicating if
-	// the field was found.
-	//
-	// FieldByNameFunc considers the fields in the struct itself
-	// and then the fields in any embedded structs, in breadth first order,
-	// stopping at the shallowest nesting depth containing one or more
-	// fields satisfying the match function. If multiple fields at that depth
-	// satisfy the match function, they cancel each other
-	// and FieldByNameFunc returns no match.
-	// This behavior mirrors Go's handling of name lookup in
-	// structs containing embedded fields.
-	FieldByNameFunc(match func(string) bool) (StructField, bool)
-
-	// In returns the type of a function type's i'th input parameter.
-	// It panics if the type's Kind is not Func.
-	// It panics if i is not in the range [0, NumIn()).
-	In(i int) Type
-
-	// Key returns a map type's key type.
-	// It panics if the type's Kind is not Map.
-	Key() Type
-
-	// Len returns an array type's length.
-	// It panics if the type's Kind is not Array.
-	Len() int
-
-	// NumField returns a struct type's field count.
-	// It panics if the type's Kind is not Struct.
-	NumField() int
-
-	// NumIn returns a function type's input parameter count.
-	// It panics if the type's Kind is not Func.
-	NumIn() int
-
-	// NumOut returns a function type's output parameter count.
-	// It panics if the type's Kind is not Func.
-	NumOut() int
-
-	// Out returns the type of a function type's i'th output parameter.
-	// It panics if the type's Kind is not Func.
-	// It panics if i is not in the range [0, NumOut()).
-	Out(i int) Type
-
-	common() *abi.Type
-	uncommon() *uncommonType
-}
-
 // A Kind represents the specific kind of type that a Type represents.
 // The zero Kind is not a valid kind.
 type Kind uint

runtime/internal/lib/reflect/type_go122.go

@@ -0,0 +1,205 @@
+//go:build !go1.23
+// +build !go1.23
+
+package reflect
+
+import (
+	"github.com/goplus/llgo/runtime/abi"
+)
+
+// Type is the representation of a Go type.
+//
+// Not all methods apply to all kinds of types. Restrictions,
+// if any, are noted in the documentation for each method.
+// Use the Kind method to find out the kind of type before
+// calling kind-specific methods. Calling a method
+// inappropriate to the kind of type causes a run-time panic.
+//
+// Type values are comparable, such as with the == operator,
+// so they can be used as map keys.
+// Two Type values are equal if they represent identical types.
+type Type interface {
+	// Methods applicable to all types.
+
+	// Align returns the alignment in bytes of a value of
+	// this type when allocated in memory.
+	Align() int
+
+	// FieldAlign returns the alignment in bytes of a value of
+	// this type when used as a field in a struct.
+	FieldAlign() int
+
+	// Method returns the i'th method in the type's method set.
+	// It panics if i is not in the range [0, NumMethod()).
+	//
+	// For a non-interface type T or *T, the returned Method's Type and Func
+	// fields describe a function whose first argument is the receiver,
+	// and only exported methods are accessible.
+	//
+	// For an interface type, the returned Method's Type field gives the
+	// method signature, without a receiver, and the Func field is nil.
+	//
+	// Methods are sorted in lexicographic order.
+	Method(int) Method
+
+	// MethodByName returns the method with that name in the type's
+	// method set and a boolean indicating if the method was found.
+	//
+	// For a non-interface type T or *T, the returned Method's Type and Func
+	// fields describe a function whose first argument is the receiver.
+	//
+	// For an interface type, the returned Method's Type field gives the
+	// method signature, without a receiver, and the Func field is nil.
+	MethodByName(string) (Method, bool)
+
+	// NumMethod returns the number of methods accessible using Method.
+	//
+	// For a non-interface type, it returns the number of exported methods.
+	//
+	// For an interface type, it returns the number of exported and unexported methods.
+	NumMethod() int
+
+	// Name returns the type's name within its package for a defined type.
+	// For other (non-defined) types it returns the empty string.
+	Name() string
+
+	// PkgPath returns a defined type's package path, that is, the import path
+	// that uniquely identifies the package, such as "encoding/base64".
+	// If the type was predeclared (string, error) or not defined (*T, struct{},
+	// []int, or A where A is an alias for a non-defined type), the package path
+	// will be the empty string.
+	PkgPath() string
+
+	// Size returns the number of bytes needed to store
+	// a value of the given type; it is analogous to unsafe.Sizeof.
+	Size() uintptr
+
+	// String returns a string representation of the type.
+	// The string representation may use shortened package names
+	// (e.g., base64 instead of "encoding/base64") and is not
+	// guaranteed to be unique among types. To test for type identity,
+	// compare the Types directly.
+	String() string
+
+	// Kind returns the specific kind of this type.
+	Kind() Kind
+
+	// Implements reports whether the type implements the interface type u.
+	Implements(u Type) bool
+
+	// AssignableTo reports whether a value of the type is assignable to type u.
+	AssignableTo(u Type) bool
+
+	// ConvertibleTo reports whether a value of the type is convertible to type u.
+	// Even if ConvertibleTo returns true, the conversion may still panic.
+	// For example, a slice of type []T is convertible to *[N]T,
+	// but the conversion will panic if its length is less than N.
+	ConvertibleTo(u Type) bool
+
+	// Comparable reports whether values of this type are comparable.
+	// Even if Comparable returns true, the comparison may still panic.
+	// For example, values of interface type are comparable,
+	// but the comparison will panic if their dynamic type is not comparable.
+	Comparable() bool
+
+	// Methods applicable only to some types, depending on Kind.
+	// The methods allowed for each kind are:
+	//
+	//	Int*, Uint*, Float*, Complex*: Bits
+	//	Array: Elem, Len
+	//	Chan: ChanDir, Elem
+	//	Func: In, NumIn, Out, NumOut, IsVariadic.
+	//	Map: Key, Elem
+	//	Pointer: Elem
+	//	Slice: Elem
+	//	Struct: Field, FieldByIndex, FieldByName, FieldByNameFunc, NumField
+
+	// Bits returns the size of the type in bits.
+	// It panics if the type's Kind is not one of the
+	// sized or unsized Int, Uint, Float, or Complex kinds.
+	Bits() int
+
+	// ChanDir returns a channel type's direction.
+	// It panics if the type's Kind is not Chan.
+	ChanDir() ChanDir
+
+	// IsVariadic reports whether a function type's final input parameter
+	// is a "..." parameter. If so, t.In(t.NumIn() - 1) returns the parameter's
+	// implicit actual type []T.
+	//
+	// For concreteness, if t represents func(x int, y ... float64), then
+	//
+	//	t.NumIn() == 2
+	//	t.In(0) is the reflect.Type for "int"
+	//	t.In(1) is the reflect.Type for "[]float64"
+	//	t.IsVariadic() == true
+	//
+	// IsVariadic panics if the type's Kind is not Func.
+	IsVariadic() bool
+
+	// Elem returns a type's element type.
+	// It panics if the type's Kind is not Array, Chan, Map, Pointer, or Slice.
+	Elem() Type
+
+	// Field returns a struct type's i'th field.
+	// It panics if the type's Kind is not Struct.
+	// It panics if i is not in the range [0, NumField()).
+	Field(i int) StructField
+
+	// FieldByIndex returns the nested field corresponding
+	// to the index sequence. It is equivalent to calling Field
+	// successively for each index i.
+	// It panics if the type's Kind is not Struct.
+	FieldByIndex(index []int) StructField
+
+	// FieldByName returns the struct field with the given name
+	// and a boolean indicating if the field was found.
+	FieldByName(name string) (StructField, bool)
+
+	// FieldByNameFunc returns the struct field with a name
+	// that satisfies the match function and a boolean indicating if
+	// the field was found.
+	//
+	// FieldByNameFunc considers the fields in the struct itself
+	// and then the fields in any embedded structs, in breadth first order,
+	// stopping at the shallowest nesting depth containing one or more
+	// fields satisfying the match function. If multiple fields at that depth
+	// satisfy the match function, they cancel each other
+	// and FieldByNameFunc returns no match.
+	// This behavior mirrors Go's handling of name lookup in
+	// structs containing embedded fields.
+	FieldByNameFunc(match func(string) bool) (StructField, bool)
+
+	// In returns the type of a function type's i'th input parameter.
+	// It panics if the type's Kind is not Func.
+	// It panics if i is not in the range [0, NumIn()).
+	In(i int) Type
+
+	// Key returns a map type's key type.
+	// It panics if the type's Kind is not Map.
+	Key() Type
+
+	// Len returns an array type's length.
+	// It panics if the type's Kind is not Array.
+	Len() int
+
+	// NumField returns a struct type's field count.
+	// It panics if the type's Kind is not Struct.
+	NumField() int
+
+	// NumIn returns a function type's input parameter count.
+	// It panics if the type's Kind is not Func.
+	NumIn() int
+
+	// NumOut returns a function type's output parameter count.
+	// It panics if the type's Kind is not Func.
+	NumOut() int
+
+	// Out returns the type of a function type's i'th output parameter.
+	// It panics if the type's Kind is not Func.
+	// It panics if i is not in the range [0, NumOut()).
+	Out(i int) Type
+
+	common() *abi.Type
+	uncommon() *uncommonType
+}

runtime/internal/lib/reflect/type_go123.go

@@ -0,0 +1,334 @@
+//go:build go1.23
+// +build go1.23
+
+package reflect
+
+import (
+	"github.com/goplus/llgo/runtime/abi"
+)
+
+// Type is the representation of a Go type.
+//
+// Not all methods apply to all kinds of types. Restrictions,
+// if any, are noted in the documentation for each method.
+// Use the Kind method to find out the kind of type before
+// calling kind-specific methods. Calling a method
+// inappropriate to the kind of type causes a run-time panic.
+//
+// Type values are comparable, such as with the == operator,
+// so they can be used as map keys.
+// Two Type values are equal if they represent identical types.
+type Type interface {
+	// Methods applicable to all types.
+
+	// Align returns the alignment in bytes of a value of
+	// this type when allocated in memory.
+	Align() int
+
+	// FieldAlign returns the alignment in bytes of a value of
+	// this type when used as a field in a struct.
+	FieldAlign() int
+
+	// Method returns the i'th method in the type's method set.
+	// It panics if i is not in the range [0, NumMethod()).
+	//
+	// For a non-interface type T or *T, the returned Method's Type and Func
+	// fields describe a function whose first argument is the receiver,
+	// and only exported methods are accessible.
+	//
+	// For an interface type, the returned Method's Type field gives the
+	// method signature, without a receiver, and the Func field is nil.
+	//
+	// Methods are sorted in lexicographic order.
+	Method(int) Method
+
+	// MethodByName returns the method with that name in the type's
+	// method set and a boolean indicating if the method was found.
+	//
+	// For a non-interface type T or *T, the returned Method's Type and Func
+	// fields describe a function whose first argument is the receiver.
+	//
+	// For an interface type, the returned Method's Type field gives the
+	// method signature, without a receiver, and the Func field is nil.
+	MethodByName(string) (Method, bool)
+
+	// NumMethod returns the number of methods accessible using Method.
+	//
+	// For a non-interface type, it returns the number of exported methods.
+	//
+	// For an interface type, it returns the number of exported and unexported methods.
+	NumMethod() int
+
+	// Name returns the type's name within its package for a defined type.
+	// For other (non-defined) types it returns the empty string.
+	Name() string
+
+	// PkgPath returns a defined type's package path, that is, the import path
+	// that uniquely identifies the package, such as "encoding/base64".
+	// If the type was predeclared (string, error) or not defined (*T, struct{},
+	// []int, or A where A is an alias for a non-defined type), the package path
+	// will be the empty string.
+	PkgPath() string
+
+	// Size returns the number of bytes needed to store
+	// a value of the given type; it is analogous to unsafe.Sizeof.
+	Size() uintptr
+
+	// String returns a string representation of the type.
+	// The string representation may use shortened package names
+	// (e.g., base64 instead of "encoding/base64") and is not
+	// guaranteed to be unique among types. To test for type identity,
+	// compare the Types directly.
+	String() string
+
+	// Kind returns the specific kind of this type.
+	Kind() Kind
+
+	// Implements reports whether the type implements the interface type u.
+	Implements(u Type) bool
+
+	// AssignableTo reports whether a value of the type is assignable to type u.
+	AssignableTo(u Type) bool
+
+	// ConvertibleTo reports whether a value of the type is convertible to type u.
+	// Even if ConvertibleTo returns true, the conversion may still panic.
+	// For example, a slice of type []T is convertible to *[N]T,
+	// but the conversion will panic if its length is less than N.
+	ConvertibleTo(u Type) bool
+
+	// Comparable reports whether values of this type are comparable.
+	// Even if Comparable returns true, the comparison may still panic.
+	// For example, values of interface type are comparable,
+	// but the comparison will panic if their dynamic type is not comparable.
+	Comparable() bool
+
+	// Methods applicable only to some types, depending on Kind.
+	// The methods allowed for each kind are:
+	//
+	//	Int*, Uint*, Float*, Complex*: Bits
+	//	Array: Elem, Len
+	//	Chan: ChanDir, Elem
+	//	Func: In, NumIn, Out, NumOut, IsVariadic.
+	//	Map: Key, Elem
+	//	Pointer: Elem
+	//	Slice: Elem
+	//	Struct: Field, FieldByIndex, FieldByName, FieldByNameFunc, NumField
+
+	// Bits returns the size of the type in bits.
+	// It panics if the type's Kind is not one of the
+	// sized or unsized Int, Uint, Float, or Complex kinds.
+	Bits() int
+
+	// ChanDir returns a channel type's direction.
+	// It panics if the type's Kind is not Chan.
+	ChanDir() ChanDir
+
+	// IsVariadic reports whether a function type's final input parameter
+	// is a "..." parameter. If so, t.In(t.NumIn() - 1) returns the parameter's
+	// implicit actual type []T.
+	//
+	// For concreteness, if t represents func(x int, y ... float64), then
+	//
+	//	t.NumIn() == 2
+	//	t.In(0) is the reflect.Type for "int"
+	//	t.In(1) is the reflect.Type for "[]float64"
+	//	t.IsVariadic() == true
+	//
+	// IsVariadic panics if the type's Kind is not Func.
+	IsVariadic() bool
+
+	// Elem returns a type's element type.
+	// It panics if the type's Kind is not Array, Chan, Map, Pointer, or Slice.
+	Elem() Type
+
+	// Field returns a struct type's i'th field.
+	// It panics if the type's Kind is not Struct.
+	// It panics if i is not in the range [0, NumField()).
+	Field(i int) StructField
+
+	// FieldByIndex returns the nested field corresponding
+	// to the index sequence. It is equivalent to calling Field
+	// successively for each index i.
+	// It panics if the type's Kind is not Struct.
+	FieldByIndex(index []int) StructField
+
+	// FieldByName returns the struct field with the given name
+	// and a boolean indicating if the field was found.
+	// If the returned field is promoted from an embedded struct,
+	// then Offset in the returned StructField is the offset in
+	// the embedded struct.
+	FieldByName(name string) (StructField, bool)
+
+	// FieldByNameFunc returns the struct field with a name
+	// that satisfies the match function and a boolean indicating if
+	// the field was found.
+	//
+	// FieldByNameFunc considers the fields in the struct itself
+	// and then the fields in any embedded structs, in breadth first order,
+	// stopping at the shallowest nesting depth containing one or more
+	// fields satisfying the match function. If multiple fields at that depth
+	// satisfy the match function, they cancel each other
+	// and FieldByNameFunc returns no match.
+	// This behavior mirrors Go's handling of name lookup in
+	// structs containing embedded fields.
+	//
+	// If the returned field is promoted from an embedded struct,
+	// then Offset in the returned StructField is the offset in
+	// the embedded struct.
+	FieldByNameFunc(match func(string) bool) (StructField, bool)
+
+	// In returns the type of a function type's i'th input parameter.
+	// It panics if the type's Kind is not Func.
+	// It panics if i is not in the range [0, NumIn()).
+	In(i int) Type
+
+	// Key returns a map type's key type.
+	// It panics if the type's Kind is not Map.
+	Key() Type
+
+	// Len returns an array type's length.
+	// It panics if the type's Kind is not Array.
+	Len() int
+
+	// NumField returns a struct type's field count.
+	// It panics if the type's Kind is not Struct.
+	NumField() int
+
+	// NumIn returns a function type's input parameter count.
+	// It panics if the type's Kind is not Func.
+	NumIn() int
+
+	// NumOut returns a function type's output parameter count.
+	// It panics if the type's Kind is not Func.
+	NumOut() int
+
+	// Out returns the type of a function type's i'th output parameter.
+	// It panics if the type's Kind is not Func.
+	// It panics if i is not in the range [0, NumOut()).
+	Out(i int) Type
+
+	// OverflowComplex reports whether the complex128 x cannot be represented by type t.
+	// It panics if t's Kind is not Complex64 or Complex128.
+	OverflowComplex(x complex128) bool
+
+	// OverflowFloat reports whether the float64 x cannot be represented by type t.
+	// It panics if t's Kind is not Float32 or Float64.
+	OverflowFloat(x float64) bool
+
+	// OverflowInt reports whether the int64 x cannot be represented by type t.
+	// It panics if t's Kind is not Int, Int8, Int16, Int32, or Int64.
+	OverflowInt(x int64) bool
+
+	// OverflowUint reports whether the uint64 x cannot be represented by type t.
+	// It panics if t's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64.
+	OverflowUint(x uint64) bool
+
+	// CanSeq reports whether a [Value] with this type can be iterated over using [Value.Seq].
+	CanSeq() bool
+
+	// CanSeq2 reports whether a [Value] with this type can be iterated over using [Value.Seq2].
+	CanSeq2() bool
+
+	common() *abi.Type
+	uncommon() *uncommonType
+}
+
+func (t *rtype) OverflowComplex(x complex128) bool {
+	k := t.Kind()
+	switch k {
+	case Complex64:
+		return overflowFloat32(real(x)) || overflowFloat32(imag(x))
+	case Complex128:
+		return false
+	}
+	panic("reflect: OverflowComplex of non-complex type " + t.String())
+}
+
+func (t *rtype) OverflowFloat(x float64) bool {
+	k := t.Kind()
+	switch k {
+	case Float32:
+		return overflowFloat32(x)
+	case Float64:
+		return false
+	}
+	panic("reflect: OverflowFloat of non-float type " + t.String())
+}
+
+func (t *rtype) OverflowInt(x int64) bool {
+	k := t.Kind()
+	switch k {
+	case Int, Int8, Int16, Int32, Int64:
+		bitSize := t.Size() * 8
+		trunc := (x << (64 - bitSize)) >> (64 - bitSize)
+		return x != trunc
+	}
+	panic("reflect: OverflowInt of non-int type " + t.String())
+}
+
+func (t *rtype) OverflowUint(x uint64) bool {
+	k := t.Kind()
+	switch k {
+	case Uint, Uintptr, Uint8, Uint16, Uint32, Uint64:
+		bitSize := t.Size() * 8
+		trunc := (x << (64 - bitSize)) >> (64 - bitSize)
+		return x != trunc
+	}
+	panic("reflect: OverflowUint of non-uint type " + t.String())
+}
+
+func (t *rtype) CanSeq() bool {
+	switch t.Kind() {
+	case Int8, Int16, Int32, Int64, Int, Uint8, Uint16, Uint32, Uint64, Uint, Uintptr, Array, Slice, Chan, String, Map:
+		return true
+	case Func:
+		return canRangeFunc(&t.t)
+	case Pointer:
+		return t.Elem().Kind() == Array
+	}
+	return false
+}
+
+func canRangeFunc(t *abi.Type) bool {
+	if t.Kind() != abi.Func {
+		return false
+	}
+	f := t.FuncType()
+	if len(f.In) != 1 || len(f.Out) != 0 {
+		return false
+	}
+	y := f.In[0]
+	if y.Kind() != abi.Func {
+		return false
+	}
+	yield := y.FuncType()
+	return len(yield.In) == 1 && len(yield.Out) == 1 && yield.Out[0].Kind() == abi.Bool
+}
+
+func (t *rtype) CanSeq2() bool {
+	switch t.Kind() {
+	case Array, Slice, String, Map:
+		return true
+	case Func:
+		return canRangeFunc2(&t.t)
+	case Pointer:
+		return t.Elem().Kind() == Array
+	}
+	return false
+}
+
+func canRangeFunc2(t *abi.Type) bool {
+	if t.Kind() != abi.Func {
+		return false
+	}
+	f := t.FuncType()
+	if len(f.In) != 1 || len(f.Out) != 0 {
+		return false
+	}
+	y := f.In[0]
+	if y.Kind() != abi.Func {
+		return false
+	}
+	yield := y.FuncType()
+	return len(yield.In) == 2 && len(yield.Out) == 1 && yield.Out[0].Kind() == abi.Bool
+}

runtime/internal/lib/reflect/value_go123.go

@@ -0,0 +1,62 @@
+package reflect
+
+import "math"
+
+// OverflowComplex reports whether the complex128 x cannot be represented by v's type.
+// It panics if v's Kind is not [Complex64] or [Complex128].
+func (v Value) OverflowComplex(x complex128) bool {
+	k := v.kind()
+	switch k {
+	case Complex64:
+		return overflowFloat32(real(x)) || overflowFloat32(imag(x))
+	case Complex128:
+		return false
+	}
+	panic(&ValueError{"reflect.Value.OverflowComplex", v.kind()})
+}
+
+// OverflowFloat reports whether the float64 x cannot be represented by v's type.
+// It panics if v's Kind is not [Float32] or [Float64].
+func (v Value) OverflowFloat(x float64) bool {
+	k := v.kind()
+	switch k {
+	case Float32:
+		return overflowFloat32(x)
+	case Float64:
+		return false
+	}
+	panic(&ValueError{"reflect.Value.OverflowFloat", v.kind()})
+}
+
+func overflowFloat32(x float64) bool {
+	if x < 0 {
+		x = -x
+	}
+	return math.MaxFloat32 < x && x <= math.MaxFloat64
+}
+
+// OverflowInt reports whether the int64 x cannot be represented by v's type.
+// It panics if v's Kind is not [Int], [Int8], [Int16], [Int32], or [Int64].
+func (v Value) OverflowInt(x int64) bool {
+	k := v.kind()
+	switch k {
+	case Int, Int8, Int16, Int32, Int64:
+		bitSize := v.typ().Size() * 8
+		trunc := (x << (64 - bitSize)) >> (64 - bitSize)
+		return x != trunc
+	}
+	panic(&ValueError{"reflect.Value.OverflowInt", v.kind()})
+}
+
+// OverflowUint reports whether the uint64 x cannot be represented by v's type.
+// It panics if v's Kind is not [Uint], [Uintptr], [Uint8], [Uint16], [Uint32], or [Uint64].
+func (v Value) OverflowUint(x uint64) bool {
+	k := v.kind()
+	switch k {
+	case Uint, Uintptr, Uint8, Uint16, Uint32, Uint64:
+		bitSize := v.typ_.Size() * 8 // ok to use v.typ_ directly as Size doesn't escape
+		trunc := (x << (64 - bitSize)) >> (64 - bitSize)
+		return x != trunc
+	}
+	panic(&ValueError{"reflect.Value.OverflowUint", v.kind()})
+}

runtime/internal/runtime/z_type.go

@@ -207,6 +207,7 @@ func Struct(pkgPath string, size uintptr, fields ...abi.StructField) *Type {
 	if len(fields) == 2 && fields[0].Name_ == "$f" && fields[0].Typ.Kind() == abi.Func &&
 		fields[1].Name_ == "$data" && fields[1].Typ.Kind() == abi.UnsafePointer {
 		ret.TFlag |= abi.TFlagClosure
+		ret.Str_ = funcStr(fields[0].Typ.FuncType())
 	}
 	rtypeList.addType(&ret.Type)
 	return &ret.Type