reflect: fix StructOf hash and string

[official-gcc.git] / libgo / go / reflect / all_test.go

// Copyright 2009 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 reflect_test

import (
        "bytes"
        "encoding/base64"
        "flag"
        "fmt"
        "io"
        "math"
        "math/rand"
        "os"
        . "reflect"
        "runtime"
        "sort"
        "strconv"
        "strings"
        "sync"
        "sync/atomic"
        "testing"
        "time"
        "unicode"
        "unicode/utf8"
        "unsafe"
)

var sink interface{}

func TestBool(t *testing.T) {
        v := ValueOf(true)
        if v.Bool() != true {
                t.Fatal("ValueOf(true).Bool() = false")
        }
}

type integer int
type T struct {
        a int
        b float64
        c string
        d *int
}

type pair struct {
        i interface{}
        s string
}

func assert(t *testing.T, s, want string) {
        if s != want {
                t.Errorf("have %#q want %#q", s, want)
        }
}

var typeTests = []pair{
        {struct{ x int }{}, "int"},
        {struct{ x int8 }{}, "int8"},
        {struct{ x int16 }{}, "int16"},
        {struct{ x int32 }{}, "int32"},
        {struct{ x int64 }{}, "int64"},
        {struct{ x uint }{}, "uint"},
        {struct{ x uint8 }{}, "uint8"},
        {struct{ x uint16 }{}, "uint16"},
        {struct{ x uint32 }{}, "uint32"},
        {struct{ x uint64 }{}, "uint64"},
        {struct{ x float32 }{}, "float32"},
        {struct{ x float64 }{}, "float64"},
        {struct{ x int8 }{}, "int8"},
        {struct{ x (**int8) }{}, "**int8"},
        {struct{ x (**integer) }{}, "**reflect_test.integer"},
        {struct{ x ([32]int32) }{}, "[32]int32"},
        {struct{ x ([]int8) }{}, "[]int8"},
        {struct{ x (map[string]int32) }{}, "map[string]int32"},
        {struct{ x (chan<- string) }{}, "chan<- string"},
        {struct {
                x struct {
                        c chan *int32
                        d float32
                }
        }{},
                "struct { c chan *int32; d float32 }",
        },
        {struct{ x (func(a int8, b int32)) }{}, "func(int8, int32)"},
        {struct {
                x struct {
                        c func(chan *integer, *int8)
                }
        }{},
                "struct { c func(chan *reflect_test.integer, *int8) }",
        },
        {struct {
                x struct {
                        a int8
                        b int32
                }
        }{},
                "struct { a int8; b int32 }",
        },
        {struct {
                x struct {
                        a int8
                        b int8
                        c int32
                }
        }{},
                "struct { a int8; b int8; c int32 }",
        },
        {struct {
                x struct {
                        a int8
                        b int8
                        c int8
                        d int32
                }
        }{},
                "struct { a int8; b int8; c int8; d int32 }",
        },
        {struct {
                x struct {
                        a int8
                        b int8
                        c int8
                        d int8
                        e int32
                }
        }{},
                "struct { a int8; b int8; c int8; d int8; e int32 }",
        },
        {struct {
                x struct {
                        a int8
                        b int8
                        c int8
                        d int8
                        e int8
                        f int32
                }
        }{},
                "struct { a int8; b int8; c int8; d int8; e int8; f int32 }",
        },
        {struct {
                x struct {
                        a int8 `reflect:"hi there"`
                }
        }{},
                `struct { a int8 "reflect:\"hi there\"" }`,
        },
        {struct {
                x struct {
                        a int8 `reflect:"hi \x00there\t\n\"\\"`
                }
        }{},
                `struct { a int8 "reflect:\"hi \\x00there\\t\\n\\\"\\\\\"" }`,
        },
        {struct {
                x struct {
                        f func(args ...int)
                }
        }{},
                "struct { f func(...int) }",
        },
        {struct {
                x (interface {
                        a(func(func(int) int) func(func(int)) int)
                        b()
                })
        }{},
                "interface { reflect_test.a(func(func(int) int) func(func(int)) int); reflect_test.b() }",
        },
        {struct {
                x struct {
                        int32
                        int64
                }
        }{},
                "struct { int32; int64 }",
        },
}

var valueTests = []pair{
        {new(int), "132"},
        {new(int8), "8"},
        {new(int16), "16"},
        {new(int32), "32"},
        {new(int64), "64"},
        {new(uint), "132"},
        {new(uint8), "8"},
        {new(uint16), "16"},
        {new(uint32), "32"},
        {new(uint64), "64"},
        {new(float32), "256.25"},
        {new(float64), "512.125"},
        {new(complex64), "532.125+10i"},
        {new(complex128), "564.25+1i"},
        {new(string), "stringy cheese"},
        {new(bool), "true"},
        {new(*int8), "*int8(0)"},
        {new(**int8), "**int8(0)"},
        {new([5]int32), "[5]int32{0, 0, 0, 0, 0}"},
        {new(**integer), "**reflect_test.integer(0)"},
        {new(map[string]int32), "map[string]int32{<can't iterate on maps>}"},
        {new(chan<- string), "chan<- string"},
        {new(func(a int8, b int32)), "func(int8, int32)(0)"},
        {new(struct {
                c chan *int32
                d float32
        }),
                "struct { c chan *int32; d float32 }{chan *int32, 0}",
        },
        {new(struct{ c func(chan *integer, *int8) }),
                "struct { c func(chan *reflect_test.integer, *int8) }{func(chan *reflect_test.integer, *int8)(0)}",
        },
        {new(struct {
                a int8
                b int32
        }),
                "struct { a int8; b int32 }{0, 0}",
        },
        {new(struct {
                a int8
                b int8
                c int32
        }),
                "struct { a int8; b int8; c int32 }{0, 0, 0}",
        },
}

func testType(t *testing.T, i int, typ Type, want string) {
        s := typ.String()
        if s != want {
                t.Errorf("#%d: have %#q, want %#q", i, s, want)
        }
}

func TestTypes(t *testing.T) {
        for i, tt := range typeTests {
                testType(t, i, ValueOf(tt.i).Field(0).Type(), tt.s)
        }
}

func TestSet(t *testing.T) {
        for i, tt := range valueTests {
                v := ValueOf(tt.i)
                v = v.Elem()
                switch v.Kind() {
                case Int:
                        v.SetInt(132)
                case Int8:
                        v.SetInt(8)
                case Int16:
                        v.SetInt(16)
                case Int32:
                        v.SetInt(32)
                case Int64:
                        v.SetInt(64)
                case Uint:
                        v.SetUint(132)
                case Uint8:
                        v.SetUint(8)
                case Uint16:
                        v.SetUint(16)
                case Uint32:
                        v.SetUint(32)
                case Uint64:
                        v.SetUint(64)
                case Float32:
                        v.SetFloat(256.25)
                case Float64:
                        v.SetFloat(512.125)
                case Complex64:
                        v.SetComplex(532.125 + 10i)
                case Complex128:
                        v.SetComplex(564.25 + 1i)
                case String:
                        v.SetString("stringy cheese")
                case Bool:
                        v.SetBool(true)
                }
                s := valueToString(v)
                if s != tt.s {
                        t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
                }
        }
}

func TestSetValue(t *testing.T) {
        for i, tt := range valueTests {
                v := ValueOf(tt.i).Elem()
                switch v.Kind() {
                case Int:
                        v.Set(ValueOf(int(132)))
                case Int8:
                        v.Set(ValueOf(int8(8)))
                case Int16:
                        v.Set(ValueOf(int16(16)))
                case Int32:
                        v.Set(ValueOf(int32(32)))
                case Int64:
                        v.Set(ValueOf(int64(64)))
                case Uint:
                        v.Set(ValueOf(uint(132)))
                case Uint8:
                        v.Set(ValueOf(uint8(8)))
                case Uint16:
                        v.Set(ValueOf(uint16(16)))
                case Uint32:
                        v.Set(ValueOf(uint32(32)))
                case Uint64:
                        v.Set(ValueOf(uint64(64)))
                case Float32:
                        v.Set(ValueOf(float32(256.25)))
                case Float64:
                        v.Set(ValueOf(512.125))
                case Complex64:
                        v.Set(ValueOf(complex64(532.125 + 10i)))
                case Complex128:
                        v.Set(ValueOf(complex128(564.25 + 1i)))
                case String:
                        v.Set(ValueOf("stringy cheese"))
                case Bool:
                        v.Set(ValueOf(true))
                }
                s := valueToString(v)
                if s != tt.s {
                        t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
                }
        }
}

func TestCanSetField(t *testing.T) {
        type embed struct{ x, X int }
        type Embed struct{ x, X int }
        type S1 struct {
                embed
                x, X int
        }
        type S2 struct {
                *embed
                x, X int
        }
        type S3 struct {
                Embed
                x, X int
        }
        type S4 struct {
                *Embed
                x, X int
        }

        type testCase struct {
                index  []int
                canSet bool
        }
        tests := []struct {
                val   Value
                cases []testCase
        }{{
                val: ValueOf(&S1{}),
                cases: []testCase{
                        {[]int{0}, false},
                        {[]int{0, 0}, false},
                        {[]int{0, 1}, true},
                        {[]int{1}, false},
                        {[]int{2}, true},
                },
        }, {
                val: ValueOf(&S2{embed: &embed{}}),
                cases: []testCase{
                        {[]int{0}, false},
                        {[]int{0, 0}, false},
                        {[]int{0, 1}, true},
                        {[]int{1}, false},
                        {[]int{2}, true},
                },
        }, {
                val: ValueOf(&S3{}),
                cases: []testCase{
                        {[]int{0}, true},
                        {[]int{0, 0}, false},
                        {[]int{0, 1}, true},
                        {[]int{1}, false},
                        {[]int{2}, true},
                },
        }, {
                val: ValueOf(&S4{Embed: &Embed{}}),
                cases: []testCase{
                        {[]int{0}, true},
                        {[]int{0, 0}, false},
                        {[]int{0, 1}, true},
                        {[]int{1}, false},
                        {[]int{2}, true},
                },
        }}

        for _, tt := range tests {
                t.Run(tt.val.Type().Name(), func(t *testing.T) {
                        for _, tc := range tt.cases {
                                f := tt.val
                                for _, i := range tc.index {
                                        if f.Kind() == Ptr {
                                                f = f.Elem()
                                        }
                                        f = f.Field(i)
                                }
                                if got := f.CanSet(); got != tc.canSet {
                                        t.Errorf("CanSet() = %v, want %v", got, tc.canSet)
                                }
                        }
                })
        }
}

var _i = 7

var valueToStringTests = []pair{
        {123, "123"},
        {123.5, "123.5"},
        {byte(123), "123"},
        {"abc", "abc"},
        {T{123, 456.75, "hello", &_i}, "reflect_test.T{123, 456.75, hello, *int(&7)}"},
        {new(chan *T), "*chan *reflect_test.T(&chan *reflect_test.T)"},
        {[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
        {&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[10]int(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"},
        {[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
        {&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[]int(&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"},
}

func TestValueToString(t *testing.T) {
        for i, test := range valueToStringTests {
                s := valueToString(ValueOf(test.i))
                if s != test.s {
                        t.Errorf("#%d: have %#q, want %#q", i, s, test.s)
                }
        }
}

func TestArrayElemSet(t *testing.T) {
        v := ValueOf(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).Elem()
        v.Index(4).SetInt(123)
        s := valueToString(v)
        const want = "[10]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
        if s != want {
                t.Errorf("[10]int: have %#q want %#q", s, want)
        }

        v = ValueOf([]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})
        v.Index(4).SetInt(123)
        s = valueToString(v)
        const want1 = "[]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
        if s != want1 {
                t.Errorf("[]int: have %#q want %#q", s, want1)
        }
}

func TestPtrPointTo(t *testing.T) {
        var ip *int32
        var i int32 = 1234
        vip := ValueOf(&ip)
        vi := ValueOf(&i).Elem()
        vip.Elem().Set(vi.Addr())
        if *ip != 1234 {
                t.Errorf("got %d, want 1234", *ip)
        }

        ip = nil
        vp := ValueOf(&ip).Elem()
        vp.Set(Zero(vp.Type()))
        if ip != nil {
                t.Errorf("got non-nil (%p), want nil", ip)
        }
}

func TestPtrSetNil(t *testing.T) {
        var i int32 = 1234
        ip := &i
        vip := ValueOf(&ip)
        vip.Elem().Set(Zero(vip.Elem().Type()))
        if ip != nil {
                t.Errorf("got non-nil (%d), want nil", *ip)
        }
}

func TestMapSetNil(t *testing.T) {
        m := make(map[string]int)
        vm := ValueOf(&m)
        vm.Elem().Set(Zero(vm.Elem().Type()))
        if m != nil {
                t.Errorf("got non-nil (%p), want nil", m)
        }
}

func TestAll(t *testing.T) {
        testType(t, 1, TypeOf((int8)(0)), "int8")
        testType(t, 2, TypeOf((*int8)(nil)).Elem(), "int8")

        typ := TypeOf((*struct {
                c chan *int32
                d float32
        })(nil))
        testType(t, 3, typ, "*struct { c chan *int32; d float32 }")
        etyp := typ.Elem()
        testType(t, 4, etyp, "struct { c chan *int32; d float32 }")
        styp := etyp
        f := styp.Field(0)
        testType(t, 5, f.Type, "chan *int32")

        f, present := styp.FieldByName("d")
        if !present {
                t.Errorf("FieldByName says present field is absent")
        }
        testType(t, 6, f.Type, "float32")

        f, present = styp.FieldByName("absent")
        if present {
                t.Errorf("FieldByName says absent field is present")
        }

        typ = TypeOf([32]int32{})
        testType(t, 7, typ, "[32]int32")
        testType(t, 8, typ.Elem(), "int32")

        typ = TypeOf((map[string]*int32)(nil))
        testType(t, 9, typ, "map[string]*int32")
        mtyp := typ
        testType(t, 10, mtyp.Key(), "string")
        testType(t, 11, mtyp.Elem(), "*int32")

        typ = TypeOf((chan<- string)(nil))
        testType(t, 12, typ, "chan<- string")
        testType(t, 13, typ.Elem(), "string")

        // make sure tag strings are not part of element type
        typ = TypeOf(struct {
                d []uint32 `reflect:"TAG"`
        }{}).Field(0).Type
        testType(t, 14, typ, "[]uint32")
}

func TestInterfaceGet(t *testing.T) {
        var inter struct {
                E interface{}
        }
        inter.E = 123.456
        v1 := ValueOf(&inter)
        v2 := v1.Elem().Field(0)
        assert(t, v2.Type().String(), "interface {}")
        i2 := v2.Interface()
        v3 := ValueOf(i2)
        assert(t, v3.Type().String(), "float64")
}

func TestInterfaceValue(t *testing.T) {
        var inter struct {
                E interface{}
        }
        inter.E = 123.456
        v1 := ValueOf(&inter)
        v2 := v1.Elem().Field(0)
        assert(t, v2.Type().String(), "interface {}")
        v3 := v2.Elem()
        assert(t, v3.Type().String(), "float64")

        i3 := v2.Interface()
        if _, ok := i3.(float64); !ok {
                t.Error("v2.Interface() did not return float64, got ", TypeOf(i3))
        }
}

func TestFunctionValue(t *testing.T) {
        var x interface{} = func() {}
        v := ValueOf(x)
        if fmt.Sprint(v.Interface()) != fmt.Sprint(x) {
                t.Fatalf("TestFunction returned wrong pointer")
        }
        assert(t, v.Type().String(), "func()")
}

var appendTests = []struct {
        orig, extra []int
}{
        {make([]int, 2, 4), []int{22}},
        {make([]int, 2, 4), []int{22, 33, 44}},
}

func sameInts(x, y []int) bool {
        if len(x) != len(y) {
                return false
        }
        for i, xx := range x {
                if xx != y[i] {
                        return false
                }
        }
        return true
}

func TestAppend(t *testing.T) {
        for i, test := range appendTests {
                origLen, extraLen := len(test.orig), len(test.extra)
                want := append(test.orig, test.extra...)
                // Convert extra from []int to []Value.
                e0 := make([]Value, len(test.extra))
                for j, e := range test.extra {
                        e0[j] = ValueOf(e)
                }
                // Convert extra from []int to *SliceValue.
                e1 := ValueOf(test.extra)
                // Test Append.
                a0 := ValueOf(test.orig)
                have0 := Append(a0, e0...).Interface().([]int)
                if !sameInts(have0, want) {
                        t.Errorf("Append #%d: have %v, want %v (%p %p)", i, have0, want, test.orig, have0)
                }
                // Check that the orig and extra slices were not modified.
                if len(test.orig) != origLen {
                        t.Errorf("Append #%d origLen: have %v, want %v", i, len(test.orig), origLen)
                }
                if len(test.extra) != extraLen {
                        t.Errorf("Append #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
                }
                // Test AppendSlice.
                a1 := ValueOf(test.orig)
                have1 := AppendSlice(a1, e1).Interface().([]int)
                if !sameInts(have1, want) {
                        t.Errorf("AppendSlice #%d: have %v, want %v", i, have1, want)
                }
                // Check that the orig and extra slices were not modified.
                if len(test.orig) != origLen {
                        t.Errorf("AppendSlice #%d origLen: have %v, want %v", i, len(test.orig), origLen)
                }
                if len(test.extra) != extraLen {
                        t.Errorf("AppendSlice #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
                }
        }
}

func TestCopy(t *testing.T) {
        a := []int{1, 2, 3, 4, 10, 9, 8, 7}
        b := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
        c := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
        for i := 0; i < len(b); i++ {
                if b[i] != c[i] {
                        t.Fatalf("b != c before test")
                }
        }
        a1 := a
        b1 := b
        aa := ValueOf(&a1).Elem()
        ab := ValueOf(&b1).Elem()
        for tocopy := 1; tocopy <= 7; tocopy++ {
                aa.SetLen(tocopy)
                Copy(ab, aa)
                aa.SetLen(8)
                for i := 0; i < tocopy; i++ {
                        if a[i] != b[i] {
                                t.Errorf("(i) tocopy=%d a[%d]=%d, b[%d]=%d",
                                        tocopy, i, a[i], i, b[i])
                        }
                }
                for i := tocopy; i < len(b); i++ {
                        if b[i] != c[i] {
                                if i < len(a) {
                                        t.Errorf("(ii) tocopy=%d a[%d]=%d, b[%d]=%d, c[%d]=%d",
                                                tocopy, i, a[i], i, b[i], i, c[i])
                                } else {
                                        t.Errorf("(iii) tocopy=%d b[%d]=%d, c[%d]=%d",
                                                tocopy, i, b[i], i, c[i])
                                }
                        } else {
                                t.Logf("tocopy=%d elem %d is okay\n", tocopy, i)
                        }
                }
        }
}

func TestCopyString(t *testing.T) {
        t.Run("Slice", func(t *testing.T) {
                s := bytes.Repeat([]byte{'_'}, 8)
                val := ValueOf(s)

                n := Copy(val, ValueOf(""))
                if expecting := []byte("________"); n != 0 || !bytes.Equal(s, expecting) {
                        t.Errorf("got n = %d, s = %s, expecting n = 0, s = %s", n, s, expecting)
                }

                n = Copy(val, ValueOf("hello"))
                if expecting := []byte("hello___"); n != 5 || !bytes.Equal(s, expecting) {
                        t.Errorf("got n = %d, s = %s, expecting n = 5, s = %s", n, s, expecting)
                }

                n = Copy(val, ValueOf("helloworld"))
                if expecting := []byte("hellowor"); n != 8 || !bytes.Equal(s, expecting) {
                        t.Errorf("got n = %d, s = %s, expecting n = 8, s = %s", n, s, expecting)
                }
        })
        t.Run("Array", func(t *testing.T) {
                s := [...]byte{'_', '_', '_', '_', '_', '_', '_', '_'}
                val := ValueOf(&s).Elem()

                n := Copy(val, ValueOf(""))
                if expecting := []byte("________"); n != 0 || !bytes.Equal(s[:], expecting) {
                        t.Errorf("got n = %d, s = %s, expecting n = 0, s = %s", n, s[:], expecting)
                }

                n = Copy(val, ValueOf("hello"))
                if expecting := []byte("hello___"); n != 5 || !bytes.Equal(s[:], expecting) {
                        t.Errorf("got n = %d, s = %s, expecting n = 5, s = %s", n, s[:], expecting)
                }

                n = Copy(val, ValueOf("helloworld"))
                if expecting := []byte("hellowor"); n != 8 || !bytes.Equal(s[:], expecting) {
                        t.Errorf("got n = %d, s = %s, expecting n = 8, s = %s", n, s[:], expecting)
                }
        })
}

func TestCopyArray(t *testing.T) {
        a := [8]int{1, 2, 3, 4, 10, 9, 8, 7}
        b := [11]int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
        c := b
        aa := ValueOf(&a).Elem()
        ab := ValueOf(&b).Elem()
        Copy(ab, aa)
        for i := 0; i < len(a); i++ {
                if a[i] != b[i] {
                        t.Errorf("(i) a[%d]=%d, b[%d]=%d", i, a[i], i, b[i])
                }
        }
        for i := len(a); i < len(b); i++ {
                if b[i] != c[i] {
                        t.Errorf("(ii) b[%d]=%d, c[%d]=%d", i, b[i], i, c[i])
                } else {
                        t.Logf("elem %d is okay\n", i)
                }
        }
}

func TestBigUnnamedStruct(t *testing.T) {
        b := struct{ a, b, c, d int64 }{1, 2, 3, 4}
        v := ValueOf(b)
        b1 := v.Interface().(struct {
                a, b, c, d int64
        })
        if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d {
                t.Errorf("ValueOf(%v).Interface().(*Big) = %v", b, b1)
        }
}

type big struct {
        a, b, c, d, e int64
}

func TestBigStruct(t *testing.T) {
        b := big{1, 2, 3, 4, 5}
        v := ValueOf(b)
        b1 := v.Interface().(big)
        if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d || b1.e != b.e {
                t.Errorf("ValueOf(%v).Interface().(big) = %v", b, b1)
        }
}

type Basic struct {
        x int
        y float32
}

type NotBasic Basic

type DeepEqualTest struct {
        a, b interface{}
        eq   bool
}

// Simple functions for DeepEqual tests.
var (
        fn1 func()             // nil.
        fn2 func()             // nil.
        fn3 = func() { fn1() } // Not nil.
)

type self struct{}

type Loop *Loop
type Loopy interface{}

var loop1, loop2 Loop
var loopy1, loopy2 Loopy

func init() {
        loop1 = &loop2
        loop2 = &loop1

        loopy1 = &loopy2
        loopy2 = &loopy1
}

var deepEqualTests = []DeepEqualTest{
        // Equalities
        {nil, nil, true},
        {1, 1, true},
        {int32(1), int32(1), true},
        {0.5, 0.5, true},
        {float32(0.5), float32(0.5), true},
        {"hello", "hello", true},
        {make([]int, 10), make([]int, 10), true},
        {&[3]int{1, 2, 3}, &[3]int{1, 2, 3}, true},
        {Basic{1, 0.5}, Basic{1, 0.5}, true},
        {error(nil), error(nil), true},
        {map[int]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, true},
        {fn1, fn2, true},

        // Inequalities
        {1, 2, false},
        {int32(1), int32(2), false},
        {0.5, 0.6, false},
        {float32(0.5), float32(0.6), false},
        {"hello", "hey", false},
        {make([]int, 10), make([]int, 11), false},
        {&[3]int{1, 2, 3}, &[3]int{1, 2, 4}, false},
        {Basic{1, 0.5}, Basic{1, 0.6}, false},
        {Basic{1, 0}, Basic{2, 0}, false},
        {map[int]string{1: "one", 3: "two"}, map[int]string{2: "two", 1: "one"}, false},
        {map[int]string{1: "one", 2: "txo"}, map[int]string{2: "two", 1: "one"}, false},
        {map[int]string{1: "one"}, map[int]string{2: "two", 1: "one"}, false},
        {map[int]string{2: "two", 1: "one"}, map[int]string{1: "one"}, false},
        {nil, 1, false},
        {1, nil, false},
        {fn1, fn3, false},
        {fn3, fn3, false},
        {[][]int{{1}}, [][]int{{2}}, false},
        {math.NaN(), math.NaN(), false},
        {&[1]float64{math.NaN()}, &[1]float64{math.NaN()}, false},
        {&[1]float64{math.NaN()}, self{}, true},
        {[]float64{math.NaN()}, []float64{math.NaN()}, false},
        {[]float64{math.NaN()}, self{}, true},
        {map[float64]float64{math.NaN(): 1}, map[float64]float64{1: 2}, false},
        {map[float64]float64{math.NaN(): 1}, self{}, true},

        // Nil vs empty: not the same.
        {[]int{}, []int(nil), false},
        {[]int{}, []int{}, true},
        {[]int(nil), []int(nil), true},
        {map[int]int{}, map[int]int(nil), false},
        {map[int]int{}, map[int]int{}, true},
        {map[int]int(nil), map[int]int(nil), true},

        // Mismatched types
        {1, 1.0, false},
        {int32(1), int64(1), false},
        {0.5, "hello", false},
        {[]int{1, 2, 3}, [3]int{1, 2, 3}, false},
        {&[3]interface{}{1, 2, 4}, &[3]interface{}{1, 2, "s"}, false},
        {Basic{1, 0.5}, NotBasic{1, 0.5}, false},
        {map[uint]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, false},

        // Possible loops.
        {&loop1, &loop1, true},
        {&loop1, &loop2, true},
        {&loopy1, &loopy1, true},
        {&loopy1, &loopy2, true},
}

func TestDeepEqual(t *testing.T) {
        for _, test := range deepEqualTests {
                if test.b == (self{}) {
                        test.b = test.a
                }
                if r := DeepEqual(test.a, test.b); r != test.eq {
                        t.Errorf("DeepEqual(%v, %v) = %v, want %v", test.a, test.b, r, test.eq)
                }
        }
}

func TestTypeOf(t *testing.T) {
        // Special case for nil
        if typ := TypeOf(nil); typ != nil {
                t.Errorf("expected nil type for nil value; got %v", typ)
        }
        for _, test := range deepEqualTests {
                v := ValueOf(test.a)
                if !v.IsValid() {
                        continue
                }
                typ := TypeOf(test.a)
                if typ != v.Type() {
                        t.Errorf("TypeOf(%v) = %v, but ValueOf(%v).Type() = %v", test.a, typ, test.a, v.Type())
                }
        }
}

type Recursive struct {
        x int
        r *Recursive
}

func TestDeepEqualRecursiveStruct(t *testing.T) {
        a, b := new(Recursive), new(Recursive)
        *a = Recursive{12, a}
        *b = Recursive{12, b}
        if !DeepEqual(a, b) {
                t.Error("DeepEqual(recursive same) = false, want true")
        }
}

type _Complex struct {
        a int
        b [3]*_Complex
        c *string
        d map[float64]float64
}

func TestDeepEqualComplexStruct(t *testing.T) {
        m := make(map[float64]float64)
        stra, strb := "hello", "hello"
        a, b := new(_Complex), new(_Complex)
        *a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
        *b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
        if !DeepEqual(a, b) {
                t.Error("DeepEqual(complex same) = false, want true")
        }
}

func TestDeepEqualComplexStructInequality(t *testing.T) {
        m := make(map[float64]float64)
        stra, strb := "hello", "helloo" // Difference is here
        a, b := new(_Complex), new(_Complex)
        *a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
        *b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
        if DeepEqual(a, b) {
                t.Error("DeepEqual(complex different) = true, want false")
        }
}

type UnexpT struct {
        m map[int]int
}

func TestDeepEqualUnexportedMap(t *testing.T) {
        // Check that DeepEqual can look at unexported fields.
        x1 := UnexpT{map[int]int{1: 2}}
        x2 := UnexpT{map[int]int{1: 2}}
        if !DeepEqual(&x1, &x2) {
                t.Error("DeepEqual(x1, x2) = false, want true")
        }

        y1 := UnexpT{map[int]int{2: 3}}
        if DeepEqual(&x1, &y1) {
                t.Error("DeepEqual(x1, y1) = true, want false")
        }
}

func check2ndField(x interface{}, offs uintptr, t *testing.T) {
        s := ValueOf(x)
        f := s.Type().Field(1)
        if f.Offset != offs {
                t.Error("mismatched offsets in structure alignment:", f.Offset, offs)
        }
}

// Check that structure alignment & offsets viewed through reflect agree with those
// from the compiler itself.
func TestAlignment(t *testing.T) {
        type T1inner struct {
                a int
        }
        type T1 struct {
                T1inner
                f int
        }
        type T2inner struct {
                a, b int
        }
        type T2 struct {
                T2inner
                f int
        }

        x := T1{T1inner{2}, 17}
        check2ndField(x, uintptr(unsafe.Pointer(&x.f))-uintptr(unsafe.Pointer(&x)), t)

        x1 := T2{T2inner{2, 3}, 17}
        check2ndField(x1, uintptr(unsafe.Pointer(&x1.f))-uintptr(unsafe.Pointer(&x1)), t)
}

func Nil(a interface{}, t *testing.T) {
        n := ValueOf(a).Field(0)
        if !n.IsNil() {
                t.Errorf("%v should be nil", a)
        }
}

func NotNil(a interface{}, t *testing.T) {
        n := ValueOf(a).Field(0)
        if n.IsNil() {
                t.Errorf("value of type %v should not be nil", ValueOf(a).Type().String())
        }
}

func TestIsNil(t *testing.T) {
        // These implement IsNil.
        // Wrap in extra struct to hide interface type.
        doNil := []interface{}{
                struct{ x *int }{},
                struct{ x interface{} }{},
                struct{ x map[string]int }{},
                struct{ x func() bool }{},
                struct{ x chan int }{},
                struct{ x []string }{},
        }
        for _, ts := range doNil {
                ty := TypeOf(ts).Field(0).Type
                v := Zero(ty)
                v.IsNil() // panics if not okay to call
        }

        // Check the implementations
        var pi struct {
                x *int
        }
        Nil(pi, t)
        pi.x = new(int)
        NotNil(pi, t)

        var si struct {
                x []int
        }
        Nil(si, t)
        si.x = make([]int, 10)
        NotNil(si, t)

        var ci struct {
                x chan int
        }
        Nil(ci, t)
        ci.x = make(chan int)
        NotNil(ci, t)

        var mi struct {
                x map[int]int
        }
        Nil(mi, t)
        mi.x = make(map[int]int)
        NotNil(mi, t)

        var ii struct {
                x interface{}
        }
        Nil(ii, t)
        ii.x = 2
        NotNil(ii, t)

        var fi struct {
                x func(t *testing.T)
        }
        Nil(fi, t)
        fi.x = TestIsNil
        NotNil(fi, t)
}

func TestInterfaceExtraction(t *testing.T) {
        var s struct {
                W io.Writer
        }

        s.W = os.Stdout
        v := Indirect(ValueOf(&s)).Field(0).Interface()
        if v != s.W.(interface{}) {
                t.Error("Interface() on interface: ", v, s.W)
        }
}

func TestNilPtrValueSub(t *testing.T) {
        var pi *int
        if pv := ValueOf(pi); pv.Elem().IsValid() {
                t.Error("ValueOf((*int)(nil)).Elem().IsValid()")
        }
}

func TestMap(t *testing.T) {
        m := map[string]int{"a": 1, "b": 2}
        mv := ValueOf(m)
        if n := mv.Len(); n != len(m) {
                t.Errorf("Len = %d, want %d", n, len(m))
        }
        keys := mv.MapKeys()
        newmap := MakeMap(mv.Type())
        for k, v := range m {
                // Check that returned Keys match keys in range.
                // These aren't required to be in the same order.
                seen := false
                for _, kv := range keys {
                        if kv.String() == k {
                                seen = true
                                break
                        }
                }
                if !seen {
                        t.Errorf("Missing key %q", k)
                }

                // Check that value lookup is correct.
                vv := mv.MapIndex(ValueOf(k))
                if vi := vv.Int(); vi != int64(v) {
                        t.Errorf("Key %q: have value %d, want %d", k, vi, v)
                }

                // Copy into new map.
                newmap.SetMapIndex(ValueOf(k), ValueOf(v))
        }
        vv := mv.MapIndex(ValueOf("not-present"))
        if vv.IsValid() {
                t.Errorf("Invalid key: got non-nil value %s", valueToString(vv))
        }

        newm := newmap.Interface().(map[string]int)
        if len(newm) != len(m) {
                t.Errorf("length after copy: newm=%d, m=%d", len(newm), len(m))
        }

        for k, v := range newm {
                mv, ok := m[k]
                if mv != v {
                        t.Errorf("newm[%q] = %d, but m[%q] = %d, %v", k, v, k, mv, ok)
                }
        }

        newmap.SetMapIndex(ValueOf("a"), Value{})
        v, ok := newm["a"]
        if ok {
                t.Errorf("newm[\"a\"] = %d after delete", v)
        }

        mv = ValueOf(&m).Elem()
        mv.Set(Zero(mv.Type()))
        if m != nil {
                t.Errorf("mv.Set(nil) failed")
        }
}

func TestNilMap(t *testing.T) {
        var m map[string]int
        mv := ValueOf(m)
        keys := mv.MapKeys()
        if len(keys) != 0 {
                t.Errorf(">0 keys for nil map: %v", keys)
        }

        // Check that value for missing key is zero.
        x := mv.MapIndex(ValueOf("hello"))
        if x.Kind() != Invalid {
                t.Errorf("m.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
        }

        // Check big value too.
        var mbig map[string][10 << 20]byte
        x = ValueOf(mbig).MapIndex(ValueOf("hello"))
        if x.Kind() != Invalid {
                t.Errorf("mbig.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
        }

        // Test that deletes from a nil map succeed.
        mv.SetMapIndex(ValueOf("hi"), Value{})
}

func TestChan(t *testing.T) {
        for loop := 0; loop < 2; loop++ {
                var c chan int
                var cv Value

                // check both ways to allocate channels
                switch loop {
                case 1:
                        c = make(chan int, 1)
                        cv = ValueOf(c)
                case 0:
                        cv = MakeChan(TypeOf(c), 1)
                        c = cv.Interface().(chan int)
                }

                // Send
                cv.Send(ValueOf(2))
                if i := <-c; i != 2 {
                        t.Errorf("reflect Send 2, native recv %d", i)
                }

                // Recv
                c <- 3
                if i, ok := cv.Recv(); i.Int() != 3 || !ok {
                        t.Errorf("native send 3, reflect Recv %d, %t", i.Int(), ok)
                }

                // TryRecv fail
                val, ok := cv.TryRecv()
                if val.IsValid() || ok {
                        t.Errorf("TryRecv on empty chan: %s, %t", valueToString(val), ok)
                }

                // TryRecv success
                c <- 4
                val, ok = cv.TryRecv()
                if !val.IsValid() {
                        t.Errorf("TryRecv on ready chan got nil")
                } else if i := val.Int(); i != 4 || !ok {
                        t.Errorf("native send 4, TryRecv %d, %t", i, ok)
                }

                // TrySend fail
                c <- 100
                ok = cv.TrySend(ValueOf(5))
                i := <-c
                if ok {
                        t.Errorf("TrySend on full chan succeeded: value %d", i)
                }

                // TrySend success
                ok = cv.TrySend(ValueOf(6))
                if !ok {
                        t.Errorf("TrySend on empty chan failed")
                        select {
                        case x := <-c:
                                t.Errorf("TrySend failed but it did send %d", x)
                        default:
                        }
                } else {
                        if i = <-c; i != 6 {
                                t.Errorf("TrySend 6, recv %d", i)
                        }
                }

                // Close
                c <- 123
                cv.Close()
                if i, ok := cv.Recv(); i.Int() != 123 || !ok {
                        t.Errorf("send 123 then close; Recv %d, %t", i.Int(), ok)
                }
                if i, ok := cv.Recv(); i.Int() != 0 || ok {
                        t.Errorf("after close Recv %d, %t", i.Int(), ok)
                }
        }

        // check creation of unbuffered channel
        var c chan int
        cv := MakeChan(TypeOf(c), 0)
        c = cv.Interface().(chan int)
        if cv.TrySend(ValueOf(7)) {
                t.Errorf("TrySend on sync chan succeeded")
        }
        if v, ok := cv.TryRecv(); v.IsValid() || ok {
                t.Errorf("TryRecv on sync chan succeeded: isvalid=%v ok=%v", v.IsValid(), ok)
        }

        // len/cap
        cv = MakeChan(TypeOf(c), 10)
        c = cv.Interface().(chan int)
        for i := 0; i < 3; i++ {
                c <- i
        }
        if l, m := cv.Len(), cv.Cap(); l != len(c) || m != cap(c) {
                t.Errorf("Len/Cap = %d/%d want %d/%d", l, m, len(c), cap(c))
        }
}

// caseInfo describes a single case in a select test.
type caseInfo struct {
        desc      string
        canSelect bool
        recv      Value
        closed    bool
        helper    func()
        panic     bool
}

var allselect = flag.Bool("allselect", false, "exhaustive select test")

func TestSelect(t *testing.T) {
        selectWatch.once.Do(func() { go selectWatcher() })

        var x exhaustive
        nch := 0
        newop := func(n int, cap int) (ch, val Value) {
                nch++
                if nch%101%2 == 1 {
                        c := make(chan int, cap)
                        ch = ValueOf(c)
                        val = ValueOf(n)
                } else {
                        c := make(chan string, cap)
                        ch = ValueOf(c)
                        val = ValueOf(fmt.Sprint(n))
                }
                return
        }

        for n := 0; x.Next(); n++ {
                if testing.Short() && n >= 1000 {
                        break
                }
                if n >= 100000 && !*allselect {
                        break
                }
                if n%100000 == 0 && testing.Verbose() {
                        println("TestSelect", n)
                }
                var cases []SelectCase
                var info []caseInfo

                // Ready send.
                if x.Maybe() {
                        ch, val := newop(len(cases), 1)
                        cases = append(cases, SelectCase{
                                Dir:  SelectSend,
                                Chan: ch,
                                Send: val,
                        })
                        info = append(info, caseInfo{desc: "ready send", canSelect: true})
                }

                // Ready recv.
                if x.Maybe() {
                        ch, val := newop(len(cases), 1)
                        ch.Send(val)
                        cases = append(cases, SelectCase{
                                Dir:  SelectRecv,
                                Chan: ch,
                        })
                        info = append(info, caseInfo{desc: "ready recv", canSelect: true, recv: val})
                }

                // Blocking send.
                if x.Maybe() {
                        ch, val := newop(len(cases), 0)
                        cases = append(cases, SelectCase{
                                Dir:  SelectSend,
                                Chan: ch,
                                Send: val,
                        })
                        // Let it execute?
                        if x.Maybe() {
                                f := func() { ch.Recv() }
                                info = append(info, caseInfo{desc: "blocking send", helper: f})
                        } else {
                                info = append(info, caseInfo{desc: "blocking send"})
                        }
                }

                // Blocking recv.
                if x.Maybe() {
                        ch, val := newop(len(cases), 0)
                        cases = append(cases, SelectCase{
                                Dir:  SelectRecv,
                                Chan: ch,
                        })
                        // Let it execute?
                        if x.Maybe() {
                                f := func() { ch.Send(val) }
                                info = append(info, caseInfo{desc: "blocking recv", recv: val, helper: f})
                        } else {
                                info = append(info, caseInfo{desc: "blocking recv"})
                        }
                }

                // Zero Chan send.
                if x.Maybe() {
                        // Maybe include value to send.
                        var val Value
                        if x.Maybe() {
                                val = ValueOf(100)
                        }
                        cases = append(cases, SelectCase{
                                Dir:  SelectSend,
                                Send: val,
                        })
                        info = append(info, caseInfo{desc: "zero Chan send"})
                }

                // Zero Chan receive.
                if x.Maybe() {
                        cases = append(cases, SelectCase{
                                Dir: SelectRecv,
                        })
                        info = append(info, caseInfo{desc: "zero Chan recv"})
                }

                // nil Chan send.
                if x.Maybe() {
                        cases = append(cases, SelectCase{
                                Dir:  SelectSend,
                                Chan: ValueOf((chan int)(nil)),
                                Send: ValueOf(101),
                        })
                        info = append(info, caseInfo{desc: "nil Chan send"})
                }

                // nil Chan recv.
                if x.Maybe() {
                        cases = append(cases, SelectCase{
                                Dir:  SelectRecv,
                                Chan: ValueOf((chan int)(nil)),
                        })
                        info = append(info, caseInfo{desc: "nil Chan recv"})
                }

                // closed Chan send.
                if x.Maybe() {
                        ch := make(chan int)
                        close(ch)
                        cases = append(cases, SelectCase{
                                Dir:  SelectSend,
                                Chan: ValueOf(ch),
                                Send: ValueOf(101),
                        })
                        info = append(info, caseInfo{desc: "closed Chan send", canSelect: true, panic: true})
                }

                // closed Chan recv.
                if x.Maybe() {
                        ch, val := newop(len(cases), 0)
                        ch.Close()
                        val = Zero(val.Type())
                        cases = append(cases, SelectCase{
                                Dir:  SelectRecv,
                                Chan: ch,
                        })
                        info = append(info, caseInfo{desc: "closed Chan recv", canSelect: true, closed: true, recv: val})
                }

                var helper func() // goroutine to help the select complete

                // Add default? Must be last case here, but will permute.
                // Add the default if the select would otherwise
                // block forever, and maybe add it anyway.
                numCanSelect := 0
                canProceed := false
                canBlock := true
                canPanic := false
                helpers := []int{}
                for i, c := range info {
                        if c.canSelect {
                                canProceed = true
                                canBlock = false
                                numCanSelect++
                                if c.panic {
                                        canPanic = true
                                }
                        } else if c.helper != nil {
                                canProceed = true
                                helpers = append(helpers, i)
                        }
                }
                if !canProceed || x.Maybe() {
                        cases = append(cases, SelectCase{
                                Dir: SelectDefault,
                        })
                        info = append(info, caseInfo{desc: "default", canSelect: canBlock})
                        numCanSelect++
                } else if canBlock {
                        // Select needs to communicate with another goroutine.
                        cas := &info[helpers[x.Choose(len(helpers))]]
                        helper = cas.helper
                        cas.canSelect = true
                        numCanSelect++
                }

                // Permute cases and case info.
                // Doing too much here makes the exhaustive loop
                // too exhausting, so just do two swaps.
                for loop := 0; loop < 2; loop++ {
                        i := x.Choose(len(cases))
                        j := x.Choose(len(cases))
                        cases[i], cases[j] = cases[j], cases[i]
                        info[i], info[j] = info[j], info[i]
                }

                if helper != nil {
                        // We wait before kicking off a goroutine to satisfy a blocked select.
                        // The pause needs to be big enough to let the select block before
                        // we run the helper, but if we lose that race once in a while it's okay: the
                        // select will just proceed immediately. Not a big deal.
                        // For short tests we can grow [sic] the timeout a bit without fear of taking too long
                        pause := 10 * time.Microsecond
                        if testing.Short() {
                                pause = 100 * time.Microsecond
                        }
                        time.AfterFunc(pause, helper)
                }

                // Run select.
                i, recv, recvOK, panicErr := runSelect(cases, info)
                if panicErr != nil && !canPanic {
                        t.Fatalf("%s\npanicked unexpectedly: %v", fmtSelect(info), panicErr)
                }
                if panicErr == nil && canPanic && numCanSelect == 1 {
                        t.Fatalf("%s\nselected #%d incorrectly (should panic)", fmtSelect(info), i)
                }
                if panicErr != nil {
                        continue
                }

                cas := info[i]
                if !cas.canSelect {
                        recvStr := ""
                        if recv.IsValid() {
                                recvStr = fmt.Sprintf(", received %v, %v", recv.Interface(), recvOK)
                        }
                        t.Fatalf("%s\nselected #%d incorrectly%s", fmtSelect(info), i, recvStr)
                        continue
                }
                if cas.panic {
                        t.Fatalf("%s\nselected #%d incorrectly (case should panic)", fmtSelect(info), i)
                        continue
                }

                if cases[i].Dir == SelectRecv {
                        if !recv.IsValid() {
                                t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, cas.recv.Interface(), !cas.closed)
                        }
                        if !cas.recv.IsValid() {
                                t.Fatalf("%s\nselected #%d but internal error: missing recv value", fmtSelect(info), i)
                        }
                        if recv.Interface() != cas.recv.Interface() || recvOK != !cas.closed {
                                if recv.Interface() == cas.recv.Interface() && recvOK == !cas.closed {
                                        t.Fatalf("%s\nselected #%d, got %#v, %v, and DeepEqual is broken on %T", fmtSelect(info), i, recv.Interface(), recvOK, recv.Interface())
                                }
                                t.Fatalf("%s\nselected #%d but got %#v, %v, want %#v, %v", fmtSelect(info), i, recv.Interface(), recvOK, cas.recv.Interface(), !cas.closed)
                        }
                } else {
                        if recv.IsValid() || recvOK {
                                t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, Value{}, false)
                        }
                }
        }
}

// selectWatch and the selectWatcher are a watchdog mechanism for running Select.
// If the selectWatcher notices that the select has been blocked for >1 second, it prints
// an error describing the select and panics the entire test binary.
var selectWatch struct {
        sync.Mutex
        once sync.Once
        now  time.Time
        info []caseInfo
}

func selectWatcher() {
        for {
                time.Sleep(1 * time.Second)
                selectWatch.Lock()
                if selectWatch.info != nil && time.Since(selectWatch.now) > 10*time.Second {
                        fmt.Fprintf(os.Stderr, "TestSelect:\n%s blocked indefinitely\n", fmtSelect(selectWatch.info))
                        panic("select stuck")
                }
                selectWatch.Unlock()
        }
}

// runSelect runs a single select test.
// It returns the values returned by Select but also returns
// a panic value if the Select panics.
func runSelect(cases []SelectCase, info []caseInfo) (chosen int, recv Value, recvOK bool, panicErr interface{}) {
        defer func() {
                panicErr = recover()

                selectWatch.Lock()
                selectWatch.info = nil
                selectWatch.Unlock()
        }()

        selectWatch.Lock()
        selectWatch.now = time.Now()
        selectWatch.info = info
        selectWatch.Unlock()

        chosen, recv, recvOK = Select(cases)
        return
}

// fmtSelect formats the information about a single select test.
func fmtSelect(info []caseInfo) string {
        var buf bytes.Buffer
        fmt.Fprintf(&buf, "\nselect {\n")
        for i, cas := range info {
                fmt.Fprintf(&buf, "%d: %s", i, cas.desc)
                if cas.recv.IsValid() {
                        fmt.Fprintf(&buf, " val=%#v", cas.recv.Interface())
                }
                if cas.canSelect {
                        fmt.Fprintf(&buf, " canselect")
                }
                if cas.panic {
                        fmt.Fprintf(&buf, " panic")
                }
                fmt.Fprintf(&buf, "\n")
        }
        fmt.Fprintf(&buf, "}")
        return buf.String()
}

type two [2]uintptr

// Difficult test for function call because of
// implicit padding between arguments.
func dummy(b byte, c int, d byte, e two, f byte, g float32, h byte) (i byte, j int, k byte, l two, m byte, n float32, o byte) {
        return b, c, d, e, f, g, h
}

func TestFunc(t *testing.T) {
        ret := ValueOf(dummy).Call([]Value{
                ValueOf(byte(10)),
                ValueOf(20),
                ValueOf(byte(30)),
                ValueOf(two{40, 50}),
                ValueOf(byte(60)),
                ValueOf(float32(70)),
                ValueOf(byte(80)),
        })
        if len(ret) != 7 {
                t.Fatalf("Call returned %d values, want 7", len(ret))
        }

        i := byte(ret[0].Uint())
        j := int(ret[1].Int())
        k := byte(ret[2].Uint())
        l := ret[3].Interface().(two)
        m := byte(ret[4].Uint())
        n := float32(ret[5].Float())
        o := byte(ret[6].Uint())

        if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
                t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o)
        }

        for i, v := range ret {
                if v.CanAddr() {
                        t.Errorf("result %d is addressable", i)
                }
        }
}

func TestCallConvert(t *testing.T) {
        v := ValueOf(new(io.ReadWriter)).Elem()
        f := ValueOf(func(r io.Reader) io.Reader { return r })
        out := f.Call([]Value{v})
        if len(out) != 1 || out[0].Type() != TypeOf(new(io.Reader)).Elem() || !out[0].IsNil() {
                t.Errorf("expected [nil], got %v", out)
        }
}

type emptyStruct struct{}

type nonEmptyStruct struct {
        member int
}

func returnEmpty() emptyStruct {
        return emptyStruct{}
}

func takesEmpty(e emptyStruct) {
}

func returnNonEmpty(i int) nonEmptyStruct {
        return nonEmptyStruct{member: i}
}

func takesNonEmpty(n nonEmptyStruct) int {
        return n.member
}

func TestCallWithStruct(t *testing.T) {
        r := ValueOf(returnEmpty).Call(nil)
        if len(r) != 1 || r[0].Type() != TypeOf(emptyStruct{}) {
                t.Errorf("returning empty struct returned %#v instead", r)
        }
        r = ValueOf(takesEmpty).Call([]Value{ValueOf(emptyStruct{})})
        if len(r) != 0 {
                t.Errorf("takesEmpty returned values: %#v", r)
        }
        r = ValueOf(returnNonEmpty).Call([]Value{ValueOf(42)})
        if len(r) != 1 || r[0].Type() != TypeOf(nonEmptyStruct{}) || r[0].Field(0).Int() != 42 {
                t.Errorf("returnNonEmpty returned %#v", r)
        }
        r = ValueOf(takesNonEmpty).Call([]Value{ValueOf(nonEmptyStruct{member: 42})})
        if len(r) != 1 || r[0].Type() != TypeOf(1) || r[0].Int() != 42 {
                t.Errorf("takesNonEmpty returned %#v", r)
        }
}

func TestCallReturnsEmpty(t *testing.T) {
        if runtime.Compiler == "gccgo" {
                t.Skip("skipping on gccgo: imprecise stack can keep i live")
        }
        // Issue 21717: past-the-end pointer write in Call with
        // nonzero-sized frame and zero-sized return value.
        runtime.GC()
        var finalized uint32
        f := func() (emptyStruct, *int) {
                i := new(int)
                runtime.SetFinalizer(i, func(*int) { atomic.StoreUint32(&finalized, 1) })
                return emptyStruct{}, i
        }
        v := ValueOf(f).Call(nil)[0] // out[0] should not alias out[1]'s memory, so the finalizer should run.
        timeout := time.After(5 * time.Second)
        for atomic.LoadUint32(&finalized) == 0 {
                select {
                case <-timeout:
                        t.Fatal("finalizer did not run")
                default:
                }
                runtime.Gosched()
                runtime.GC()
        }
        runtime.KeepAlive(v)
}

func BenchmarkCall(b *testing.B) {
        fv := ValueOf(func(a, b string) {})
        b.ReportAllocs()
        b.RunParallel(func(pb *testing.PB) {
                args := []Value{ValueOf("a"), ValueOf("b")}
                for pb.Next() {
                        fv.Call(args)
                }
        })
}

func BenchmarkCallArgCopy(b *testing.B) {
        byteArray := func(n int) Value {
                return Zero(ArrayOf(n, TypeOf(byte(0))))
        }
        sizes := [...]struct {
                fv  Value
                arg Value
        }{
                {ValueOf(func(a [128]byte) {}), byteArray(128)},
                {ValueOf(func(a [256]byte) {}), byteArray(256)},
                {ValueOf(func(a [1024]byte) {}), byteArray(1024)},
                {ValueOf(func(a [4096]byte) {}), byteArray(4096)},
                {ValueOf(func(a [65536]byte) {}), byteArray(65536)},
        }
        for _, size := range sizes {
                bench := func(b *testing.B) {
                        args := []Value{size.arg}
                        b.SetBytes(int64(size.arg.Len()))
                        b.ResetTimer()
                        b.RunParallel(func(pb *testing.PB) {
                                for pb.Next() {
                                        size.fv.Call(args)
                                }
                        })
                }
                name := fmt.Sprintf("size=%v", size.arg.Len())
                b.Run(name, bench)
        }
}

func TestMakeFunc(t *testing.T) {
        f := dummy
        fv := MakeFunc(TypeOf(f), func(in []Value) []Value { return in })
        ValueOf(&f).Elem().Set(fv)

        // Call g with small arguments so that there is
        // something predictable (and different from the
        // correct results) in those positions on the stack.
        g := dummy
        g(1, 2, 3, two{4, 5}, 6, 7, 8)

        // Call constructed function f.
        i, j, k, l, m, n, o := f(10, 20, 30, two{40, 50}, 60, 70, 80)
        if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
                t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o)
        }
}

func TestMakeFuncInterface(t *testing.T) {
        fn := func(i int) int { return i }
        incr := func(in []Value) []Value {
                return []Value{ValueOf(int(in[0].Int() + 1))}
        }
        fv := MakeFunc(TypeOf(fn), incr)
        ValueOf(&fn).Elem().Set(fv)
        if r := fn(2); r != 3 {
                t.Errorf("Call returned %d, want 3", r)
        }
        if r := fv.Call([]Value{ValueOf(14)})[0].Int(); r != 15 {
                t.Errorf("Call returned %d, want 15", r)
        }
        if r := fv.Interface().(func(int) int)(26); r != 27 {
                t.Errorf("Call returned %d, want 27", r)
        }
}

func TestMakeFuncVariadic(t *testing.T) {
        // Test that variadic arguments are packed into a slice and passed as last arg
        fn := func(_ int, is ...int) []int { return nil }
        fv := MakeFunc(TypeOf(fn), func(in []Value) []Value { return in[1:2] })
        ValueOf(&fn).Elem().Set(fv)

        r := fn(1, 2, 3)
        if r[0] != 2 || r[1] != 3 {
                t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
        }

        r = fn(1, []int{2, 3}...)
        if r[0] != 2 || r[1] != 3 {
                t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
        }

        r = fv.Call([]Value{ValueOf(1), ValueOf(2), ValueOf(3)})[0].Interface().([]int)
        if r[0] != 2 || r[1] != 3 {
                t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
        }

        r = fv.CallSlice([]Value{ValueOf(1), ValueOf([]int{2, 3})})[0].Interface().([]int)
        if r[0] != 2 || r[1] != 3 {
                t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
        }

        f := fv.Interface().(func(int, ...int) []int)

        r = f(1, 2, 3)
        if r[0] != 2 || r[1] != 3 {
                t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
        }
        r = f(1, []int{2, 3}...)
        if r[0] != 2 || r[1] != 3 {
                t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
        }
}

type Point struct {
        x, y int
}

// This will be index 0.
func (p Point) AnotherMethod(scale int) int {
        return -1
}

// This will be index 1.
func (p Point) Dist(scale int) int {
        //println("Point.Dist", p.x, p.y, scale)
        return p.x*p.x*scale + p.y*p.y*scale
}

// This will be index 2.
func (p Point) GCMethod(k int) int {
        runtime.GC()
        return k + p.x
}

// This will be index 3.
func (p Point) NoArgs() {
        // Exercise no-argument/no-result paths.
}

// This will be index 4.
func (p Point) TotalDist(points ...Point) int {
        tot := 0
        for _, q := range points {
                dx := q.x - p.x
                dy := q.y - p.y
                tot += dx*dx + dy*dy // Should call Sqrt, but it's just a test.

        }
        return tot
}

func TestMethod(t *testing.T) {
        // Non-curried method of type.
        p := Point{3, 4}
        i := TypeOf(p).Method(1).Func.Call([]Value{ValueOf(p), ValueOf(10)})[0].Int()
        if i != 250 {
                t.Errorf("Type Method returned %d; want 250", i)
        }

        m, ok := TypeOf(p).MethodByName("Dist")
        if !ok {
                t.Fatalf("method by name failed")
        }
        i = m.Func.Call([]Value{ValueOf(p), ValueOf(11)})[0].Int()
        if i != 275 {
                t.Errorf("Type MethodByName returned %d; want 275", i)
        }

        m, ok = TypeOf(p).MethodByName("NoArgs")
        if !ok {
                t.Fatalf("method by name failed")
        }
        n := len(m.Func.Call([]Value{ValueOf(p)}))
        if n != 0 {
                t.Errorf("NoArgs returned %d values; want 0", n)
        }

        i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(12)})[0].Int()
        if i != 300 {
                t.Errorf("Pointer Type Method returned %d; want 300", i)
        }

        m, ok = TypeOf(&p).MethodByName("Dist")
        if !ok {
                t.Fatalf("ptr method by name failed")
        }
        i = m.Func.Call([]Value{ValueOf(&p), ValueOf(13)})[0].Int()
        if i != 325 {
                t.Errorf("Pointer Type MethodByName returned %d; want 325", i)
        }

        m, ok = TypeOf(&p).MethodByName("NoArgs")
        if !ok {
                t.Fatalf("method by name failed")
        }
        n = len(m.Func.Call([]Value{ValueOf(&p)}))
        if n != 0 {
                t.Errorf("NoArgs returned %d values; want 0", n)
        }

        // Curried method of value.
        tfunc := TypeOf((func(int) int)(nil))
        v := ValueOf(p).Method(1)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
        }
        i = v.Call([]Value{ValueOf(14)})[0].Int()
        if i != 350 {
                t.Errorf("Value Method returned %d; want 350", i)
        }
        v = ValueOf(p).MethodByName("Dist")
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
        }
        i = v.Call([]Value{ValueOf(15)})[0].Int()
        if i != 375 {
                t.Errorf("Value MethodByName returned %d; want 375", i)
        }
        v = ValueOf(p).MethodByName("NoArgs")
        v.Call(nil)

        // Curried method of pointer.
        v = ValueOf(&p).Method(1)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
        }
        i = v.Call([]Value{ValueOf(16)})[0].Int()
        if i != 400 {
                t.Errorf("Pointer Value Method returned %d; want 400", i)
        }
        v = ValueOf(&p).MethodByName("Dist")
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
        }
        i = v.Call([]Value{ValueOf(17)})[0].Int()
        if i != 425 {
                t.Errorf("Pointer Value MethodByName returned %d; want 425", i)
        }
        v = ValueOf(&p).MethodByName("NoArgs")
        v.Call(nil)

        // Curried method of interface value.
        // Have to wrap interface value in a struct to get at it.
        // Passing it to ValueOf directly would
        // access the underlying Point, not the interface.
        var x interface {
                Dist(int) int
        } = p
        pv := ValueOf(&x).Elem()
        v = pv.Method(0)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
        }
        i = v.Call([]Value{ValueOf(18)})[0].Int()
        if i != 450 {
                t.Errorf("Interface Method returned %d; want 450", i)
        }
        v = pv.MethodByName("Dist")
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
        }
        i = v.Call([]Value{ValueOf(19)})[0].Int()
        if i != 475 {
                t.Errorf("Interface MethodByName returned %d; want 475", i)
        }
}

func TestMethodValue(t *testing.T) {
        p := Point{3, 4}
        var i int64

        // Curried method of value.
        tfunc := TypeOf((func(int) int)(nil))
        v := ValueOf(p).Method(1)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(10)})[0].Int()
        if i != 250 {
                t.Errorf("Value Method returned %d; want 250", i)
        }
        v = ValueOf(p).MethodByName("Dist")
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(11)})[0].Int()
        if i != 275 {
                t.Errorf("Value MethodByName returned %d; want 275", i)
        }
        v = ValueOf(p).MethodByName("NoArgs")
        ValueOf(v.Interface()).Call(nil)
        v.Interface().(func())()

        // Curried method of pointer.
        v = ValueOf(&p).Method(1)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(12)})[0].Int()
        if i != 300 {
                t.Errorf("Pointer Value Method returned %d; want 300", i)
        }
        v = ValueOf(&p).MethodByName("Dist")
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(13)})[0].Int()
        if i != 325 {
                t.Errorf("Pointer Value MethodByName returned %d; want 325", i)
        }
        v = ValueOf(&p).MethodByName("NoArgs")
        ValueOf(v.Interface()).Call(nil)
        v.Interface().(func())()

        // Curried method of pointer to pointer.
        pp := &p
        v = ValueOf(&pp).Elem().Method(1)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Pointer Pointer Value Method Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(14)})[0].Int()
        if i != 350 {
                t.Errorf("Pointer Pointer Value Method returned %d; want 350", i)
        }
        v = ValueOf(&pp).Elem().MethodByName("Dist")
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Pointer Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(15)})[0].Int()
        if i != 375 {
                t.Errorf("Pointer Pointer Value MethodByName returned %d; want 375", i)
        }

        // Curried method of interface value.
        // Have to wrap interface value in a struct to get at it.
        // Passing it to ValueOf directly would
        // access the underlying Point, not the interface.
        var s = struct {
                X interface {
                        Dist(int) int
                }
        }{p}
        pv := ValueOf(s).Field(0)
        v = pv.Method(0)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(16)})[0].Int()
        if i != 400 {
                t.Errorf("Interface Method returned %d; want 400", i)
        }
        v = pv.MethodByName("Dist")
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
        }
        i = ValueOf(v.Interface()).Call([]Value{ValueOf(17)})[0].Int()
        if i != 425 {
                t.Errorf("Interface MethodByName returned %d; want 425", i)
        }
}

func TestVariadicMethodValue(t *testing.T) {
        p := Point{3, 4}
        points := []Point{{20, 21}, {22, 23}, {24, 25}}
        want := int64(p.TotalDist(points[0], points[1], points[2]))

        // Curried method of value.
        tfunc := TypeOf((func(...Point) int)(nil))
        v := ValueOf(p).Method(4)
        if tt := v.Type(); tt != tfunc {
                t.Errorf("Variadic Method Type is %s; want %s", tt, tfunc)
        }
        i := ValueOf(v.Interface()).Call([]Value{ValueOf(points[0]), ValueOf(points[1]), ValueOf(points[2])})[0].Int()
        if i != want {
                t.Errorf("Variadic Method returned %d; want %d", i, want)
        }
        i = ValueOf(v.Interface()).CallSlice([]Value{ValueOf(points)})[0].Int()
        if i != want {
                t.Errorf("Variadic Method CallSlice returned %d; want %d", i, want)
        }

        f := v.Interface().(func(...Point) int)
        i = int64(f(points[0], points[1], points[2]))
        if i != want {
                t.Errorf("Variadic Method Interface returned %d; want %d", i, want)
        }
        i = int64(f(points...))
        if i != want {
                t.Errorf("Variadic Method Interface Slice returned %d; want %d", i, want)
        }
}

// Reflect version of $GOROOT/test/method5.go

// Concrete types implementing M method.
// Smaller than a word, word-sized, larger than a word.
// Value and pointer receivers.

type Tinter interface {
        M(int, byte) (byte, int)
}

type Tsmallv byte

func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x + int(v) }

type Tsmallp byte

func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x + int(*p) }

type Twordv uintptr

func (v Twordv) M(x int, b byte) (byte, int) { return b, x + int(v) }

type Twordp uintptr

func (p *Twordp) M(x int, b byte) (byte, int) { return b, x + int(*p) }

type Tbigv [2]uintptr

func (v Tbigv) M(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) }

type Tbigp [2]uintptr

func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) }

type tinter interface {
        m(int, byte) (byte, int)
}

// Embedding via pointer.

type Tm1 struct {
        Tm2
}

type Tm2 struct {
        *Tm3
}

type Tm3 struct {
        *Tm4
}

type Tm4 struct {
}

func (t4 Tm4) M(x int, b byte) (byte, int) { return b, x + 40 }

func TestMethod5(t *testing.T) {
        CheckF := func(name string, f func(int, byte) (byte, int), inc int) {
                b, x := f(1000, 99)
                if b != 99 || x != 1000+inc {
                        t.Errorf("%s(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
                }
        }

        CheckV := func(name string, i Value, inc int) {
                bx := i.Method(0).Call([]Value{ValueOf(1000), ValueOf(byte(99))})
                b := bx[0].Interface()
                x := bx[1].Interface()
                if b != byte(99) || x != 1000+inc {
                        t.Errorf("direct %s.M(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
                }

                CheckF(name+".M", i.Method(0).Interface().(func(int, byte) (byte, int)), inc)
        }

        var TinterType = TypeOf(new(Tinter)).Elem()

        CheckI := func(name string, i interface{}, inc int) {
                v := ValueOf(i)
                CheckV(name, v, inc)
                CheckV("(i="+name+")", v.Convert(TinterType), inc)
        }

        sv := Tsmallv(1)
        CheckI("sv", sv, 1)
        CheckI("&sv", &sv, 1)

        sp := Tsmallp(2)
        CheckI("&sp", &sp, 2)

        wv := Twordv(3)
        CheckI("wv", wv, 3)
        CheckI("&wv", &wv, 3)

        wp := Twordp(4)
        CheckI("&wp", &wp, 4)

        bv := Tbigv([2]uintptr{5, 6})
        CheckI("bv", bv, 11)
        CheckI("&bv", &bv, 11)

        bp := Tbigp([2]uintptr{7, 8})
        CheckI("&bp", &bp, 15)

        t4 := Tm4{}
        t3 := Tm3{&t4}
        t2 := Tm2{&t3}
        t1 := Tm1{t2}
        CheckI("t4", t4, 40)
        CheckI("&t4", &t4, 40)
        CheckI("t3", t3, 40)
        CheckI("&t3", &t3, 40)
        CheckI("t2", t2, 40)
        CheckI("&t2", &t2, 40)
        CheckI("t1", t1, 40)
        CheckI("&t1", &t1, 40)

        var tnil Tinter
        vnil := ValueOf(&tnil).Elem()
        shouldPanic(func() { vnil.Method(0) })
}

func TestInterfaceSet(t *testing.T) {
        p := &Point{3, 4}

        var s struct {
                I interface{}
                P interface {
                        Dist(int) int
                }
        }
        sv := ValueOf(&s).Elem()
        sv.Field(0).Set(ValueOf(p))
        if q := s.I.(*Point); q != p {
                t.Errorf("i: have %p want %p", q, p)
        }

        pv := sv.Field(1)
        pv.Set(ValueOf(p))
        if q := s.P.(*Point); q != p {
                t.Errorf("i: have %p want %p", q, p)
        }

        i := pv.Method(0).Call([]Value{ValueOf(10)})[0].Int()
        if i != 250 {
                t.Errorf("Interface Method returned %d; want 250", i)
        }
}

type T1 struct {
        a string
        int
}

func TestAnonymousFields(t *testing.T) {
        var field StructField
        var ok bool
        var t1 T1
        type1 := TypeOf(t1)
        if field, ok = type1.FieldByName("int"); !ok {
                t.Fatal("no field 'int'")
        }
        if field.Index[0] != 1 {
                t.Error("field index should be 1; is", field.Index)
        }
}

type FTest struct {
        s     interface{}
        name  string
        index []int
        value int
}

type D1 struct {
        d int
}
type D2 struct {
        d int
}

type S0 struct {
        A, B, C int
        D1
        D2
}

type S1 struct {
        B int
        S0
}

type S2 struct {
        A int
        *S1
}

type S1x struct {
        S1
}

type S1y struct {
        S1
}

type S3 struct {
        S1x
        S2
        D, E int
        *S1y
}

type S4 struct {
        *S4
        A int
}

// The X in S6 and S7 annihilate, but they also block the X in S8.S9.
type S5 struct {
        S6
        S7
        S8
}

type S6 struct {
        X int
}

type S7 S6

type S8 struct {
        S9
}

type S9 struct {
        X int
        Y int
}

// The X in S11.S6 and S12.S6 annihilate, but they also block the X in S13.S8.S9.
type S10 struct {
        S11
        S12
        S13
}

type S11 struct {
        S6
}

type S12 struct {
        S6
}

type S13 struct {
        S8
}

// The X in S15.S11.S1 and S16.S11.S1 annihilate.
type S14 struct {
        S15
        S16
}

type S15 struct {
        S11
}

type S16 struct {
        S11
}

var fieldTests = []FTest{
        {struct{}{}, "", nil, 0},
        {struct{}{}, "Foo", nil, 0},
        {S0{A: 'a'}, "A", []int{0}, 'a'},
        {S0{}, "D", nil, 0},
        {S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'},
        {S1{B: 'b'}, "B", []int{0}, 'b'},
        {S1{}, "S0", []int{1}, 0},
        {S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'},
        {S2{A: 'a'}, "A", []int{0}, 'a'},
        {S2{}, "S1", []int{1}, 0},
        {S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'},
        {S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'},
        {S2{}, "D", nil, 0},
        {S3{}, "S1", nil, 0},
        {S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'},
        {S3{}, "B", nil, 0},
        {S3{D: 'd'}, "D", []int{2}, 0},
        {S3{E: 'e'}, "E", []int{3}, 'e'},
        {S4{A: 'a'}, "A", []int{1}, 'a'},
        {S4{}, "B", nil, 0},
        {S5{}, "X", nil, 0},
        {S5{}, "Y", []int{2, 0, 1}, 0},
        {S10{}, "X", nil, 0},
        {S10{}, "Y", []int{2, 0, 0, 1}, 0},
        {S14{}, "X", nil, 0},
}

func TestFieldByIndex(t *testing.T) {
        for _, test := range fieldTests {
                s := TypeOf(test.s)
                f := s.FieldByIndex(test.index)
                if f.Name != "" {
                        if test.index != nil {
                                if f.Name != test.name {
                                        t.Errorf("%s.%s found; want %s", s.Name(), f.Name, test.name)
                                }
                        } else {
                                t.Errorf("%s.%s found", s.Name(), f.Name)
                        }
                } else if len(test.index) > 0 {
                        t.Errorf("%s.%s not found", s.Name(), test.name)
                }

                if test.value != 0 {
                        v := ValueOf(test.s).FieldByIndex(test.index)
                        if v.IsValid() {
                                if x, ok := v.Interface().(int); ok {
                                        if x != test.value {
                                                t.Errorf("%s%v is %d; want %d", s.Name(), test.index, x, test.value)
                                        }
                                } else {
                                        t.Errorf("%s%v value not an int", s.Name(), test.index)
                                }
                        } else {
                                t.Errorf("%s%v value not found", s.Name(), test.index)
                        }
                }
        }
}

func TestFieldByName(t *testing.T) {
        for _, test := range fieldTests {
                s := TypeOf(test.s)
                f, found := s.FieldByName(test.name)
                if found {
                        if test.index != nil {
                                // Verify field depth and index.
                                if len(f.Index) != len(test.index) {
                                        t.Errorf("%s.%s depth %d; want %d: %v vs %v", s.Name(), test.name, len(f.Index), len(test.index), f.Index, test.index)
                                } else {
                                        for i, x := range f.Index {
                                                if x != test.index[i] {
                                                        t.Errorf("%s.%s.Index[%d] is %d; want %d", s.Name(), test.name, i, x, test.index[i])
                                                }
                                        }
                                }
                        } else {
                                t.Errorf("%s.%s found", s.Name(), f.Name)
                        }
                } else if len(test.index) > 0 {
                        t.Errorf("%s.%s not found", s.Name(), test.name)
                }

                if test.value != 0 {
                        v := ValueOf(test.s).FieldByName(test.name)
                        if v.IsValid() {
                                if x, ok := v.Interface().(int); ok {
                                        if x != test.value {
                                                t.Errorf("%s.%s is %d; want %d", s.Name(), test.name, x, test.value)
                                        }
                                } else {
                                        t.Errorf("%s.%s value not an int", s.Name(), test.name)
                                }
                        } else {
                                t.Errorf("%s.%s value not found", s.Name(), test.name)
                        }
                }
        }
}

func TestImportPath(t *testing.T) {
        tests := []struct {
                t    Type
                path string
        }{
                {TypeOf(&base64.Encoding{}).Elem(), "encoding/base64"},
                {TypeOf(int(0)), ""},
                {TypeOf(int8(0)), ""},
                {TypeOf(int16(0)), ""},
                {TypeOf(int32(0)), ""},
                {TypeOf(int64(0)), ""},
                {TypeOf(uint(0)), ""},
                {TypeOf(uint8(0)), ""},
                {TypeOf(uint16(0)), ""},
                {TypeOf(uint32(0)), ""},
                {TypeOf(uint64(0)), ""},
                {TypeOf(uintptr(0)), ""},
                {TypeOf(float32(0)), ""},
                {TypeOf(float64(0)), ""},
                {TypeOf(complex64(0)), ""},
                {TypeOf(complex128(0)), ""},
                {TypeOf(byte(0)), ""},
                {TypeOf(rune(0)), ""},
                {TypeOf([]byte(nil)), ""},
                {TypeOf([]rune(nil)), ""},
                {TypeOf(string("")), ""},
                {TypeOf((*interface{})(nil)).Elem(), ""},
                {TypeOf((*byte)(nil)), ""},
                {TypeOf((*rune)(nil)), ""},
                {TypeOf((*int64)(nil)), ""},
                {TypeOf(map[string]int{}), ""},
                {TypeOf((*error)(nil)).Elem(), ""},
                {TypeOf((*Point)(nil)), ""},
                {TypeOf((*Point)(nil)).Elem(), "reflect_test"},
        }
        for _, test := range tests {
                if path := test.t.PkgPath(); path != test.path {
                        t.Errorf("%v.PkgPath() = %q, want %q", test.t, path, test.path)
                }
        }
}

func TestFieldPkgPath(t *testing.T) {
        type x int
        typ := TypeOf(struct {
                Exported   string
                unexported string
                OtherPkgFields
                int // issue 21702
                *x  // issue 21122
        }{})

        type pkgpathTest struct {
                index     []int
                pkgPath   string
                anonymous bool
        }

        checkPkgPath := func(name string, s []pkgpathTest) {
                for _, test := range s {
                        f := typ.FieldByIndex(test.index)
                        if got, want := f.PkgPath, test.pkgPath; got != want {
                                t.Errorf("%s: Field(%d).PkgPath = %q, want %q", name, test.index, got, want)
                        }
                        if got, want := f.Anonymous, test.anonymous; got != want {
                                t.Errorf("%s: Field(%d).Anonymous = %v, want %v", name, test.index, got, want)
                        }
                }
        }

        checkPkgPath("testStruct", []pkgpathTest{
                {[]int{0}, "", false},             // Exported
                {[]int{1}, "reflect_test", false}, // unexported
                {[]int{2}, "", true},              // OtherPkgFields
                {[]int{2, 0}, "", false},          // OtherExported
                {[]int{2, 1}, "reflect", false},   // otherUnexported
                {[]int{3}, "reflect_test", true},  // int
                {[]int{4}, "reflect_test", true},  // *x
        })

        type localOtherPkgFields OtherPkgFields
        typ = TypeOf(localOtherPkgFields{})
        checkPkgPath("localOtherPkgFields", []pkgpathTest{
                {[]int{0}, "", false},        // OtherExported
                {[]int{1}, "reflect", false}, // otherUnexported
        })
}

func TestVariadicType(t *testing.T) {
        // Test example from Type documentation.
        var f func(x int, y ...float64)
        typ := TypeOf(f)
        if typ.NumIn() == 2 && typ.In(0) == TypeOf(int(0)) {
                sl := typ.In(1)
                if sl.Kind() == Slice {
                        if sl.Elem() == TypeOf(0.0) {
                                // ok
                                return
                        }
                }
        }

        // Failed
        t.Errorf("want NumIn() = 2, In(0) = int, In(1) = []float64")
        s := fmt.Sprintf("have NumIn() = %d", typ.NumIn())
        for i := 0; i < typ.NumIn(); i++ {
                s += fmt.Sprintf(", In(%d) = %s", i, typ.In(i))
        }
        t.Error(s)
}

type inner struct {
        x int
}

type outer struct {
        y int
        inner
}

func (*inner) M() {}
func (*outer) M() {}

func TestNestedMethods(t *testing.T) {
        t.Skip("fails on gccgo due to function wrappers")
        typ := TypeOf((*outer)(nil))
        if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*outer).M).Pointer() {
                t.Errorf("Wrong method table for outer: (M=%p)", (*outer).M)
                for i := 0; i < typ.NumMethod(); i++ {
                        m := typ.Method(i)
                        t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer())
                }
        }
}

type unexp struct{}

func (*unexp) f() (int32, int8) { return 7, 7 }
func (*unexp) g() (int64, int8) { return 8, 8 }

type unexpI interface {
        f() (int32, int8)
}

var unexpi unexpI = new(unexp)

func TestUnexportedMethods(t *testing.T) {
        typ := TypeOf(unexpi)

        if got := typ.NumMethod(); got != 0 {
                t.Errorf("NumMethod=%d, want 0 satisfied methods", got)
        }
}

type InnerInt struct {
        X int
}

type OuterInt struct {
        Y int
        InnerInt
}

func (i *InnerInt) M() int {
        return i.X
}

func TestEmbeddedMethods(t *testing.T) {
        /* This part of the test fails on gccgo due to function wrappers.
        typ := TypeOf((*OuterInt)(nil))
        if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*OuterInt).M).Pointer() {
                t.Errorf("Wrong method table for OuterInt: (m=%p)", (*OuterInt).M)
                for i := 0; i < typ.NumMethod(); i++ {
                        m := typ.Method(i)
                        t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer())
                }
        }
        */

        i := &InnerInt{3}
        if v := ValueOf(i).Method(0).Call(nil)[0].Int(); v != 3 {
                t.Errorf("i.M() = %d, want 3", v)
        }

        o := &OuterInt{1, InnerInt{2}}
        if v := ValueOf(o).Method(0).Call(nil)[0].Int(); v != 2 {
                t.Errorf("i.M() = %d, want 2", v)
        }

        f := (*OuterInt).M
        if v := f(o); v != 2 {
                t.Errorf("f(o) = %d, want 2", v)
        }
}

type FuncDDD func(...interface{}) error

func (f FuncDDD) M() {}

func TestNumMethodOnDDD(t *testing.T) {
        rv := ValueOf((FuncDDD)(nil))
        if n := rv.NumMethod(); n != 1 {
                t.Fatalf("NumMethod()=%d, want 1", n)
        }
}

func TestPtrTo(t *testing.T) {
        // This block of code means that the ptrToThis field of the
        // reflect data for *unsafe.Pointer is non zero, see
        // https://golang.org/issue/19003
        var x unsafe.Pointer
        var y = &x
        var z = &y

        var i int

        typ := TypeOf(z)
        for i = 0; i < 100; i++ {
                typ = PtrTo(typ)
        }
        for i = 0; i < 100; i++ {
                typ = typ.Elem()
        }
        if typ != TypeOf(z) {
                t.Errorf("after 100 PtrTo and Elem, have %s, want %s", typ, TypeOf(z))
        }
}

func TestPtrToGC(t *testing.T) {
        type T *uintptr
        tt := TypeOf(T(nil))
        pt := PtrTo(tt)
        const n = 100
        var x []interface{}
        for i := 0; i < n; i++ {
                v := New(pt)
                p := new(*uintptr)
                *p = new(uintptr)
                **p = uintptr(i)
                v.Elem().Set(ValueOf(p).Convert(pt))
                x = append(x, v.Interface())
        }
        runtime.GC()

        for i, xi := range x {
                k := ValueOf(xi).Elem().Elem().Elem().Interface().(uintptr)
                if k != uintptr(i) {
                        t.Errorf("lost x[%d] = %d, want %d", i, k, i)
                }
        }
}

func BenchmarkPtrTo(b *testing.B) {
        // Construct a type with a zero ptrToThis.
        type T struct{ int }
        t := SliceOf(TypeOf(T{}))
        ptrToThis := ValueOf(t).Elem().FieldByName("ptrToThis")
        if !ptrToThis.IsValid() {
                b.Fatalf("%v has no ptrToThis field; was it removed from rtype?", t)
        }
        if ptrToThis.Int() != 0 {
                b.Fatalf("%v.ptrToThis unexpectedly nonzero", t)
        }
        b.ResetTimer()

        // Now benchmark calling PtrTo on it: we'll have to hit the ptrMap cache on
        // every call.
        b.RunParallel(func(pb *testing.PB) {
                for pb.Next() {
                        PtrTo(t)
                }
        })
}

func TestAddr(t *testing.T) {
        var p struct {
                X, Y int
        }

        v := ValueOf(&p)
        v = v.Elem()
        v = v.Addr()
        v = v.Elem()
        v = v.Field(0)
        v.SetInt(2)
        if p.X != 2 {
                t.Errorf("Addr.Elem.Set failed to set value")
        }

        // Again but take address of the ValueOf value.
        // Exercises generation of PtrTypes not present in the binary.
        q := &p
        v = ValueOf(&q).Elem()
        v = v.Addr()
        v = v.Elem()
        v = v.Elem()
        v = v.Addr()
        v = v.Elem()
        v = v.Field(0)
        v.SetInt(3)
        if p.X != 3 {
                t.Errorf("Addr.Elem.Set failed to set value")
        }

        // Starting without pointer we should get changed value
        // in interface.
        qq := p
        v = ValueOf(&qq).Elem()
        v0 := v
        v = v.Addr()
        v = v.Elem()
        v = v.Field(0)
        v.SetInt(4)
        if p.X != 3 { // should be unchanged from last time
                t.Errorf("somehow value Set changed original p")
        }
        p = v0.Interface().(struct {
                X, Y int
        })
        if p.X != 4 {
                t.Errorf("Addr.Elem.Set valued to set value in top value")
        }

        // Verify that taking the address of a type gives us a pointer
        // which we can convert back using the usual interface
        // notation.
        var s struct {
                B *bool
        }
        ps := ValueOf(&s).Elem().Field(0).Addr().Interface()
        *(ps.(**bool)) = new(bool)
        if s.B == nil {
                t.Errorf("Addr.Interface direct assignment failed")
        }
}

/* gccgo does do allocations here.

func noAlloc(t *testing.T, n int, f func(int)) {
        if testing.Short() {
                t.Skip("skipping malloc count in short mode")
        }
        if runtime.GOMAXPROCS(0) > 1 {
                t.Skip("skipping; GOMAXPROCS>1")
        }
        i := -1
        allocs := testing.AllocsPerRun(n, func() {
                f(i)
                i++
        })
        if allocs > 0 {
                t.Errorf("%d iterations: got %v mallocs, want 0", n, allocs)
        }
}

func TestAllocations(t *testing.T) {
        noAlloc(t, 100, func(j int) {
                var i interface{}
                var v Value

                // We can uncomment this when compiler escape analysis
                // is good enough to see that the integer assigned to i
                // does not escape and therefore need not be allocated.
                //
                // i = 42 + j
                // v = ValueOf(i)
                // if int(v.Int()) != 42+j {
                //      panic("wrong int")
                // }

                i = func(j int) int { return j }
                v = ValueOf(i)
                if v.Interface().(func(int) int)(j) != j {
                        panic("wrong result")
                }
        })
}

*/

func TestSmallNegativeInt(t *testing.T) {
        i := int16(-1)
        v := ValueOf(i)
        if v.Int() != -1 {
                t.Errorf("int16(-1).Int() returned %v", v.Int())
        }
}

func TestIndex(t *testing.T) {
        xs := []byte{1, 2, 3, 4, 5, 6, 7, 8}
        v := ValueOf(xs).Index(3).Interface().(byte)
        if v != xs[3] {
                t.Errorf("xs.Index(3) = %v; expected %v", v, xs[3])
        }
        xa := [8]byte{10, 20, 30, 40, 50, 60, 70, 80}
        v = ValueOf(xa).Index(2).Interface().(byte)
        if v != xa[2] {
                t.Errorf("xa.Index(2) = %v; expected %v", v, xa[2])
        }
        s := "0123456789"
        v = ValueOf(s).Index(3).Interface().(byte)
        if v != s[3] {
                t.Errorf("s.Index(3) = %v; expected %v", v, s[3])
        }
}

func TestSlice(t *testing.T) {
        xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
        v := ValueOf(xs).Slice(3, 5).Interface().([]int)
        if len(v) != 2 {
                t.Errorf("len(xs.Slice(3, 5)) = %d", len(v))
        }
        if cap(v) != 5 {
                t.Errorf("cap(xs.Slice(3, 5)) = %d", cap(v))
        }
        if !DeepEqual(v[0:5], xs[3:]) {
                t.Errorf("xs.Slice(3, 5)[0:5] = %v", v[0:5])
        }
        xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
        v = ValueOf(&xa).Elem().Slice(2, 5).Interface().([]int)
        if len(v) != 3 {
                t.Errorf("len(xa.Slice(2, 5)) = %d", len(v))
        }
        if cap(v) != 6 {
                t.Errorf("cap(xa.Slice(2, 5)) = %d", cap(v))
        }
        if !DeepEqual(v[0:6], xa[2:]) {
                t.Errorf("xs.Slice(2, 5)[0:6] = %v", v[0:6])
        }
        s := "0123456789"
        vs := ValueOf(s).Slice(3, 5).Interface().(string)
        if vs != s[3:5] {
                t.Errorf("s.Slice(3, 5) = %q; expected %q", vs, s[3:5])
        }

        rv := ValueOf(&xs).Elem()
        rv = rv.Slice(3, 4)
        ptr2 := rv.Pointer()
        rv = rv.Slice(5, 5)
        ptr3 := rv.Pointer()
        if ptr3 != ptr2 {
                t.Errorf("xs.Slice(3,4).Slice3(5,5).Pointer() = %#x, want %#x", ptr3, ptr2)
        }
}

func TestSlice3(t *testing.T) {
        xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
        v := ValueOf(xs).Slice3(3, 5, 7).Interface().([]int)
        if len(v) != 2 {
                t.Errorf("len(xs.Slice3(3, 5, 7)) = %d", len(v))
        }
        if cap(v) != 4 {
                t.Errorf("cap(xs.Slice3(3, 5, 7)) = %d", cap(v))
        }
        if !DeepEqual(v[0:4], xs[3:7:7]) {
                t.Errorf("xs.Slice3(3, 5, 7)[0:4] = %v", v[0:4])
        }
        rv := ValueOf(&xs).Elem()
        shouldPanic(func() { rv.Slice3(1, 2, 1) })
        shouldPanic(func() { rv.Slice3(1, 1, 11) })
        shouldPanic(func() { rv.Slice3(2, 2, 1) })

        xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
        v = ValueOf(&xa).Elem().Slice3(2, 5, 6).Interface().([]int)
        if len(v) != 3 {
                t.Errorf("len(xa.Slice(2, 5, 6)) = %d", len(v))
        }
        if cap(v) != 4 {
                t.Errorf("cap(xa.Slice(2, 5, 6)) = %d", cap(v))
        }
        if !DeepEqual(v[0:4], xa[2:6:6]) {
                t.Errorf("xs.Slice(2, 5, 6)[0:4] = %v", v[0:4])
        }
        rv = ValueOf(&xa).Elem()
        shouldPanic(func() { rv.Slice3(1, 2, 1) })
        shouldPanic(func() { rv.Slice3(1, 1, 11) })
        shouldPanic(func() { rv.Slice3(2, 2, 1) })

        s := "hello world"
        rv = ValueOf(&s).Elem()
        shouldPanic(func() { rv.Slice3(1, 2, 3) })

        rv = ValueOf(&xs).Elem()
        rv = rv.Slice3(3, 5, 7)
        ptr2 := rv.Pointer()
        rv = rv.Slice3(4, 4, 4)
        ptr3 := rv.Pointer()
        if ptr3 != ptr2 {
                t.Errorf("xs.Slice3(3,5,7).Slice3(4,4,4).Pointer() = %#x, want %#x", ptr3, ptr2)
        }
}

func TestSetLenCap(t *testing.T) {
        xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
        xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}

        vs := ValueOf(&xs).Elem()
        shouldPanic(func() { vs.SetLen(10) })
        shouldPanic(func() { vs.SetCap(10) })
        shouldPanic(func() { vs.SetLen(-1) })
        shouldPanic(func() { vs.SetCap(-1) })
        shouldPanic(func() { vs.SetCap(6) }) // smaller than len
        vs.SetLen(5)
        if len(xs) != 5 || cap(xs) != 8 {
                t.Errorf("after SetLen(5), len, cap = %d, %d, want 5, 8", len(xs), cap(xs))
        }
        vs.SetCap(6)
        if len(xs) != 5 || cap(xs) != 6 {
                t.Errorf("after SetCap(6), len, cap = %d, %d, want 5, 6", len(xs), cap(xs))
        }
        vs.SetCap(5)
        if len(xs) != 5 || cap(xs) != 5 {
                t.Errorf("after SetCap(5), len, cap = %d, %d, want 5, 5", len(xs), cap(xs))
        }
        shouldPanic(func() { vs.SetCap(4) }) // smaller than len
        shouldPanic(func() { vs.SetLen(6) }) // bigger than cap

        va := ValueOf(&xa).Elem()
        shouldPanic(func() { va.SetLen(8) })
        shouldPanic(func() { va.SetCap(8) })
}

func TestVariadic(t *testing.T) {
        var b bytes.Buffer
        V := ValueOf

        b.Reset()
        V(fmt.Fprintf).Call([]Value{V(&b), V("%s, %d world"), V("hello"), V(42)})
        if b.String() != "hello, 42 world" {
                t.Errorf("after Fprintf Call: %q != %q", b.String(), "hello 42 world")
        }

        b.Reset()
        V(fmt.Fprintf).CallSlice([]Value{V(&b), V("%s, %d world"), V([]interface{}{"hello", 42})})
        if b.String() != "hello, 42 world" {
                t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world")
        }
}

func TestFuncArg(t *testing.T) {
        f1 := func(i int, f func(int) int) int { return f(i) }
        f2 := func(i int) int { return i + 1 }
        r := ValueOf(f1).Call([]Value{ValueOf(100), ValueOf(f2)})
        if r[0].Int() != 101 {
                t.Errorf("function returned %d, want 101", r[0].Int())
        }
}

func TestStructArg(t *testing.T) {
        type padded struct {
                B string
                C int32
        }
        var (
                gotA  padded
                gotB  uint32
                wantA = padded{"3", 4}
                wantB = uint32(5)
        )
        f := func(a padded, b uint32) {
                gotA, gotB = a, b
        }
        ValueOf(f).Call([]Value{ValueOf(wantA), ValueOf(wantB)})
        if gotA != wantA || gotB != wantB {
                t.Errorf("function called with (%v, %v), want (%v, %v)", gotA, gotB, wantA, wantB)
        }
}

var tagGetTests = []struct {
        Tag   StructTag
        Key   string
        Value string
}{
        {`protobuf:"PB(1,2)"`, `protobuf`, `PB(1,2)`},
        {`protobuf:"PB(1,2)"`, `foo`, ``},
        {`protobuf:"PB(1,2)"`, `rotobuf`, ``},
        {`protobuf:"PB(1,2)" json:"name"`, `json`, `name`},
        {`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`},
        {`k0:"values contain spaces" k1:"and\ttabs"`, "k0", "values contain spaces"},
        {`k0:"values contain spaces" k1:"and\ttabs"`, "k1", "and\ttabs"},
}

func TestTagGet(t *testing.T) {
        for _, tt := range tagGetTests {
                if v := tt.Tag.Get(tt.Key); v != tt.Value {
                        t.Errorf("StructTag(%#q).Get(%#q) = %#q, want %#q", tt.Tag, tt.Key, v, tt.Value)
                }
        }
}

func TestBytes(t *testing.T) {
        type B []byte
        x := B{1, 2, 3, 4}
        y := ValueOf(x).Bytes()
        if !bytes.Equal(x, y) {
                t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
        }
        if &x[0] != &y[0] {
                t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
        }
}

func TestSetBytes(t *testing.T) {
        type B []byte
        var x B
        y := []byte{1, 2, 3, 4}
        ValueOf(&x).Elem().SetBytes(y)
        if !bytes.Equal(x, y) {
                t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
        }
        if &x[0] != &y[0] {
                t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
        }
}

type Private struct {
        x int
        y **int
        Z int
}

func (p *Private) m() {
}

type private struct {
        Z int
        z int
        S string
        A [1]Private
        T []Private
}

func (p *private) P() {
}

type Public struct {
        X int
        Y **int
        private
}

func (p *Public) M() {
}

func TestUnexported(t *testing.T) {
        var pub Public
        pub.S = "S"
        pub.T = pub.A[:]
        v := ValueOf(&pub)
        isValid(v.Elem().Field(0))
        isValid(v.Elem().Field(1))
        isValid(v.Elem().Field(2))
        isValid(v.Elem().FieldByName("X"))
        isValid(v.Elem().FieldByName("Y"))
        isValid(v.Elem().FieldByName("Z"))
        isValid(v.Type().Method(0).Func)
        m, _ := v.Type().MethodByName("M")
        isValid(m.Func)
        m, _ = v.Type().MethodByName("P")
        isValid(m.Func)
        isNonNil(v.Elem().Field(0).Interface())
        isNonNil(v.Elem().Field(1).Interface())
        isNonNil(v.Elem().Field(2).Field(2).Index(0))
        isNonNil(v.Elem().FieldByName("X").Interface())
        isNonNil(v.Elem().FieldByName("Y").Interface())
        isNonNil(v.Elem().FieldByName("Z").Interface())
        isNonNil(v.Elem().FieldByName("S").Index(0).Interface())
        isNonNil(v.Type().Method(0).Func.Interface())
        m, _ = v.Type().MethodByName("P")
        isNonNil(m.Func.Interface())

        var priv Private
        v = ValueOf(&priv)
        isValid(v.Elem().Field(0))
        isValid(v.Elem().Field(1))
        isValid(v.Elem().FieldByName("x"))
        isValid(v.Elem().FieldByName("y"))
        shouldPanic(func() { v.Elem().Field(0).Interface() })
        shouldPanic(func() { v.Elem().Field(1).Interface() })
        shouldPanic(func() { v.Elem().FieldByName("x").Interface() })
        shouldPanic(func() { v.Elem().FieldByName("y").Interface() })
        shouldPanic(func() { v.Type().Method(0) })
}

func TestSetPanic(t *testing.T) {
        ok := func(f func()) { f() }
        bad := shouldPanic
        clear := func(v Value) { v.Set(Zero(v.Type())) }

        type t0 struct {
                W int
        }

        type t1 struct {
                Y int
                t0
        }

        type T2 struct {
                Z       int
                namedT0 t0
        }

        type T struct {
                X int
                t1
                T2
                NamedT1 t1
                NamedT2 T2
                namedT1 t1
                namedT2 T2
        }

        // not addressable
        v := ValueOf(T{})
        bad(func() { clear(v.Field(0)) })                   // .X
        bad(func() { clear(v.Field(1)) })                   // .t1
        bad(func() { clear(v.Field(1).Field(0)) })          // .t1.Y
        bad(func() { clear(v.Field(1).Field(1)) })          // .t1.t0
        bad(func() { clear(v.Field(1).Field(1).Field(0)) }) // .t1.t0.W
        bad(func() { clear(v.Field(2)) })                   // .T2
        bad(func() { clear(v.Field(2).Field(0)) })          // .T2.Z
        bad(func() { clear(v.Field(2).Field(1)) })          // .T2.namedT0
        bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W
        bad(func() { clear(v.Field(3)) })                   // .NamedT1
        bad(func() { clear(v.Field(3).Field(0)) })          // .NamedT1.Y
        bad(func() { clear(v.Field(3).Field(1)) })          // .NamedT1.t0
        bad(func() { clear(v.Field(3).Field(1).Field(0)) }) // .NamedT1.t0.W
        bad(func() { clear(v.Field(4)) })                   // .NamedT2
        bad(func() { clear(v.Field(4).Field(0)) })          // .NamedT2.Z
        bad(func() { clear(v.Field(4).Field(1)) })          // .NamedT2.namedT0
        bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W
        bad(func() { clear(v.Field(5)) })                   // .namedT1
        bad(func() { clear(v.Field(5).Field(0)) })          // .namedT1.Y
        bad(func() { clear(v.Field(5).Field(1)) })          // .namedT1.t0
        bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W
        bad(func() { clear(v.Field(6)) })                   // .namedT2
        bad(func() { clear(v.Field(6).Field(0)) })          // .namedT2.Z
        bad(func() { clear(v.Field(6).Field(1)) })          // .namedT2.namedT0
        bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W

        // addressable
        v = ValueOf(&T{}).Elem()
        ok(func() { clear(v.Field(0)) })                    // .X
        bad(func() { clear(v.Field(1)) })                   // .t1
        ok(func() { clear(v.Field(1).Field(0)) })           // .t1.Y
        bad(func() { clear(v.Field(1).Field(1)) })          // .t1.t0
        ok(func() { clear(v.Field(1).Field(1).Field(0)) })  // .t1.t0.W
        ok(func() { clear(v.Field(2)) })                    // .T2
        ok(func() { clear(v.Field(2).Field(0)) })           // .T2.Z
        bad(func() { clear(v.Field(2).Field(1)) })          // .T2.namedT0
        bad(func() { clear(v.Field(2).Field(1).Field(0)) }) // .T2.namedT0.W
        ok(func() { clear(v.Field(3)) })                    // .NamedT1
        ok(func() { clear(v.Field(3).Field(0)) })           // .NamedT1.Y
        bad(func() { clear(v.Field(3).Field(1)) })          // .NamedT1.t0
        ok(func() { clear(v.Field(3).Field(1).Field(0)) })  // .NamedT1.t0.W
        ok(func() { clear(v.Field(4)) })                    // .NamedT2
        ok(func() { clear(v.Field(4).Field(0)) })           // .NamedT2.Z
        bad(func() { clear(v.Field(4).Field(1)) })          // .NamedT2.namedT0
        bad(func() { clear(v.Field(4).Field(1).Field(0)) }) // .NamedT2.namedT0.W
        bad(func() { clear(v.Field(5)) })                   // .namedT1
        bad(func() { clear(v.Field(5).Field(0)) })          // .namedT1.Y
        bad(func() { clear(v.Field(5).Field(1)) })          // .namedT1.t0
        bad(func() { clear(v.Field(5).Field(1).Field(0)) }) // .namedT1.t0.W
        bad(func() { clear(v.Field(6)) })                   // .namedT2
        bad(func() { clear(v.Field(6).Field(0)) })          // .namedT2.Z
        bad(func() { clear(v.Field(6).Field(1)) })          // .namedT2.namedT0
        bad(func() { clear(v.Field(6).Field(1).Field(0)) }) // .namedT2.namedT0.W
}

type timp int

func (t timp) W() {}
func (t timp) Y() {}
func (t timp) w() {}
func (t timp) y() {}

func TestCallPanic(t *testing.T) {
        type t0 interface {
                W()
                w()
        }
        type T1 interface {
                Y()
                y()
        }
        type T2 struct {
                T1
                t0
        }
        type T struct {
                t0 // 0
                T1 // 1

                NamedT0 t0 // 2
                NamedT1 T1 // 3
                NamedT2 T2 // 4

                namedT0 t0 // 5
                namedT1 T1 // 6
                namedT2 T2 // 7
        }
        ok := func(f func()) { f() }
        bad := shouldPanic
        call := func(v Value) { v.Call(nil) }

        i := timp(0)
        v := ValueOf(T{i, i, i, i, T2{i, i}, i, i, T2{i, i}})
        ok(func() { call(v.Field(0).Method(0)) })         // .t0.W
        bad(func() { call(v.Field(0).Elem().Method(0)) }) // .t0.W
        bad(func() { call(v.Field(0).Method(1)) })        // .t0.w
        bad(func() { call(v.Field(0).Elem().Method(2)) }) // .t0.w
        ok(func() { call(v.Field(1).Method(0)) })         // .T1.Y
        ok(func() { call(v.Field(1).Elem().Method(0)) })  // .T1.Y
        bad(func() { call(v.Field(1).Method(1)) })        // .T1.y
        bad(func() { call(v.Field(1).Elem().Method(2)) }) // .T1.y

        ok(func() { call(v.Field(2).Method(0)) })         // .NamedT0.W
        ok(func() { call(v.Field(2).Elem().Method(0)) })  // .NamedT0.W
        bad(func() { call(v.Field(2).Method(1)) })        // .NamedT0.w
        bad(func() { call(v.Field(2).Elem().Method(2)) }) // .NamedT0.w

        ok(func() { call(v.Field(3).Method(0)) })         // .NamedT1.Y
        ok(func() { call(v.Field(3).Elem().Method(0)) })  // .NamedT1.Y
        bad(func() { call(v.Field(3).Method(1)) })        // .NamedT1.y
        bad(func() { call(v.Field(3).Elem().Method(3)) }) // .NamedT1.y

        ok(func() { call(v.Field(4).Field(0).Method(0)) })         // .NamedT2.T1.Y
        ok(func() { call(v.Field(4).Field(0).Elem().Method(0)) })  // .NamedT2.T1.W
        ok(func() { call(v.Field(4).Field(1).Method(0)) })         // .NamedT2.t0.W
        bad(func() { call(v.Field(4).Field(1).Elem().Method(0)) }) // .NamedT2.t0.W

        bad(func() { call(v.Field(5).Method(0)) })        // .namedT0.W
        bad(func() { call(v.Field(5).Elem().Method(0)) }) // .namedT0.W
        bad(func() { call(v.Field(5).Method(1)) })        // .namedT0.w
        bad(func() { call(v.Field(5).Elem().Method(2)) }) // .namedT0.w

        bad(func() { call(v.Field(6).Method(0)) })        // .namedT1.Y
        bad(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.Y
        bad(func() { call(v.Field(6).Method(0)) })        // .namedT1.y
        bad(func() { call(v.Field(6).Elem().Method(0)) }) // .namedT1.y

        bad(func() { call(v.Field(7).Field(0).Method(0)) })        // .namedT2.T1.Y
        bad(func() { call(v.Field(7).Field(0).Elem().Method(0)) }) // .namedT2.T1.W
        bad(func() { call(v.Field(7).Field(1).Method(0)) })        // .namedT2.t0.W
        bad(func() { call(v.Field(7).Field(1).Elem().Method(0)) }) // .namedT2.t0.W
}

func shouldPanic(f func()) {
        defer func() {
                if recover() == nil {
                        panic("did not panic")
                }
        }()
        f()
}

func isNonNil(x interface{}) {
        if x == nil {
                panic("nil interface")
        }
}

func isValid(v Value) {
        if !v.IsValid() {
                panic("zero Value")
        }
}

func TestAlias(t *testing.T) {
        x := string("hello")
        v := ValueOf(&x).Elem()
        oldvalue := v.Interface()
        v.SetString("world")
        newvalue := v.Interface()

        if oldvalue != "hello" || newvalue != "world" {
                t.Errorf("aliasing: old=%q new=%q, want hello, world", oldvalue, newvalue)
        }
}

var V = ValueOf

func EmptyInterfaceV(x interface{}) Value {
        return ValueOf(&x).Elem()
}

func ReaderV(x io.Reader) Value {
        return ValueOf(&x).Elem()
}

func ReadWriterV(x io.ReadWriter) Value {
        return ValueOf(&x).Elem()
}

type Empty struct{}
type MyStruct struct {
        x int `some:"tag"`
}
type MyString string
type MyBytes []byte
type MyRunes []int32
type MyFunc func()
type MyByte byte

var convertTests = []struct {
        in  Value
        out Value
}{
        // numbers
        /*
                Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go

                package main

                import "fmt"

                var numbers = []string{
                        "int8", "uint8", "int16", "uint16",
                        "int32", "uint32", "int64", "uint64",
                        "int", "uint", "uintptr",
                        "float32", "float64",
                }

                func main() {
                        // all pairs but in an unusual order,
                        // to emit all the int8, uint8 cases
                        // before n grows too big.
                        n := 1
                        for i, f := range numbers {
                                for _, g := range numbers[i:] {
                                        fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n)
                                        n++
                                        if f != g {
                                                fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n)
                                                n++
                                        }
                                }
                        }
                }
        */
        {V(int8(1)), V(int8(1))},
        {V(int8(2)), V(uint8(2))},
        {V(uint8(3)), V(int8(3))},
        {V(int8(4)), V(int16(4))},
        {V(int16(5)), V(int8(5))},
        {V(int8(6)), V(uint16(6))},
        {V(uint16(7)), V(int8(7))},
        {V(int8(8)), V(int32(8))},
        {V(int32(9)), V(int8(9))},
        {V(int8(10)), V(uint32(10))},
        {V(uint32(11)), V(int8(11))},
        {V(int8(12)), V(int64(12))},
        {V(int64(13)), V(int8(13))},
        {V(int8(14)), V(uint64(14))},
        {V(uint64(15)), V(int8(15))},
        {V(int8(16)), V(int(16))},
        {V(int(17)), V(int8(17))},
        {V(int8(18)), V(uint(18))},
        {V(uint(19)), V(int8(19))},
        {V(int8(20)), V(uintptr(20))},
        {V(uintptr(21)), V(int8(21))},
        {V(int8(22)), V(float32(22))},
        {V(float32(23)), V(int8(23))},
        {V(int8(24)), V(float64(24))},
        {V(float64(25)), V(int8(25))},
        {V(uint8(26)), V(uint8(26))},
        {V(uint8(27)), V(int16(27))},
        {V(int16(28)), V(uint8(28))},
        {V(uint8(29)), V(uint16(29))},
        {V(uint16(30)), V(uint8(30))},
        {V(uint8(31)), V(int32(31))},
        {V(int32(32)), V(uint8(32))},
        {V(uint8(33)), V(uint32(33))},
        {V(uint32(34)), V(uint8(34))},
        {V(uint8(35)), V(int64(35))},
        {V(int64(36)), V(uint8(36))},
        {V(uint8(37)), V(uint64(37))},
        {V(uint64(38)), V(uint8(38))},
        {V(uint8(39)), V(int(39))},
        {V(int(40)), V(uint8(40))},
        {V(uint8(41)), V(uint(41))},
        {V(uint(42)), V(uint8(42))},
        {V(uint8(43)), V(uintptr(43))},
        {V(uintptr(44)), V(uint8(44))},
        {V(uint8(45)), V(float32(45))},
        {V(float32(46)), V(uint8(46))},
        {V(uint8(47)), V(float64(47))},
        {V(float64(48)), V(uint8(48))},
        {V(int16(49)), V(int16(49))},
        {V(int16(50)), V(uint16(50))},
        {V(uint16(51)), V(int16(51))},
        {V(int16(52)), V(int32(52))},
        {V(int32(53)), V(int16(53))},
        {V(int16(54)), V(uint32(54))},
        {V(uint32(55)), V(int16(55))},
        {V(int16(56)), V(int64(56))},
        {V(int64(57)), V(int16(57))},
        {V(int16(58)), V(uint64(58))},
        {V(uint64(59)), V(int16(59))},
        {V(int16(60)), V(int(60))},
        {V(int(61)), V(int16(61))},
        {V(int16(62)), V(uint(62))},
        {V(uint(63)), V(int16(63))},
        {V(int16(64)), V(uintptr(64))},
        {V(uintptr(65)), V(int16(65))},
        {V(int16(66)), V(float32(66))},
        {V(float32(67)), V(int16(67))},
        {V(int16(68)), V(float64(68))},
        {V(float64(69)), V(int16(69))},
        {V(uint16(70)), V(uint16(70))},
        {V(uint16(71)), V(int32(71))},
        {V(int32(72)), V(uint16(72))},
        {V(uint16(73)), V(uint32(73))},
        {V(uint32(74)), V(uint16(74))},
        {V(uint16(75)), V(int64(75))},
        {V(int64(76)), V(uint16(76))},
        {V(uint16(77)), V(uint64(77))},
        {V(uint64(78)), V(uint16(78))},
        {V(uint16(79)), V(int(79))},
        {V(int(80)), V(uint16(80))},
        {V(uint16(81)), V(uint(81))},
        {V(uint(82)), V(uint16(82))},
        {V(uint16(83)), V(uintptr(83))},
        {V(uintptr(84)), V(uint16(84))},
        {V(uint16(85)), V(float32(85))},
        {V(float32(86)), V(uint16(86))},
        {V(uint16(87)), V(float64(87))},
        {V(float64(88)), V(uint16(88))},
        {V(int32(89)), V(int32(89))},
        {V(int32(90)), V(uint32(90))},
        {V(uint32(91)), V(int32(91))},
        {V(int32(92)), V(int64(92))},
        {V(int64(93)), V(int32(93))},
        {V(int32(94)), V(uint64(94))},
        {V(uint64(95)), V(int32(95))},
        {V(int32(96)), V(int(96))},
        {V(int(97)), V(int32(97))},
        {V(int32(98)), V(uint(98))},
        {V(uint(99)), V(int32(99))},
        {V(int32(100)), V(uintptr(100))},
        {V(uintptr(101)), V(int32(101))},
        {V(int32(102)), V(float32(102))},
        {V(float32(103)), V(int32(103))},
        {V(int32(104)), V(float64(104))},
        {V(float64(105)), V(int32(105))},
        {V(uint32(106)), V(uint32(106))},
        {V(uint32(107)), V(int64(107))},
        {V(int64(108)), V(uint32(108))},
        {V(uint32(109)), V(uint64(109))},
        {V(uint64(110)), V(uint32(110))},
        {V(uint32(111)), V(int(111))},
        {V(int(112)), V(uint32(112))},
        {V(uint32(113)), V(uint(113))},
        {V(uint(114)), V(uint32(114))},
        {V(uint32(115)), V(uintptr(115))},
        {V(uintptr(116)), V(uint32(116))},
        {V(uint32(117)), V(float32(117))},
        {V(float32(118)), V(uint32(118))},
        {V(uint32(119)), V(float64(119))},
        {V(float64(120)), V(uint32(120))},
        {V(int64(121)), V(int64(121))},
        {V(int64(122)), V(uint64(122))},
        {V(uint64(123)), V(int64(123))},
        {V(int64(124)), V(int(124))},
        {V(int(125)), V(int64(125))},
        {V(int64(126)), V(uint(126))},
        {V(uint(127)), V(int64(127))},
        {V(int64(128)), V(uintptr(128))},
        {V(uintptr(129)), V(int64(129))},
        {V(int64(130)), V(float32(130))},
        {V(float32(131)), V(int64(131))},
        {V(int64(132)), V(float64(132))},
        {V(float64(133)), V(int64(133))},
        {V(uint64(134)), V(uint64(134))},
        {V(uint64(135)), V(int(135))},
        {V(int(136)), V(uint64(136))},
        {V(uint64(137)), V(uint(137))},
        {V(uint(138)), V(uint64(138))},
        {V(uint64(139)), V(uintptr(139))},
        {V(uintptr(140)), V(uint64(140))},
        {V(uint64(141)), V(float32(141))},
        {V(float32(142)), V(uint64(142))},
        {V(uint64(143)), V(float64(143))},
        {V(float64(144)), V(uint64(144))},
        {V(int(145)), V(int(145))},
        {V(int(146)), V(uint(146))},
        {V(uint(147)), V(int(147))},
        {V(int(148)), V(uintptr(148))},
        {V(uintptr(149)), V(int(149))},
        {V(int(150)), V(float32(150))},
        {V(float32(151)), V(int(151))},
        {V(int(152)), V(float64(152))},
        {V(float64(153)), V(int(153))},
        {V(uint(154)), V(uint(154))},
        {V(uint(155)), V(uintptr(155))},
        {V(uintptr(156)), V(uint(156))},
        {V(uint(157)), V(float32(157))},
        {V(float32(158)), V(uint(158))},
        {V(uint(159)), V(float64(159))},
        {V(float64(160)), V(uint(160))},
        {V(uintptr(161)), V(uintptr(161))},
        {V(uintptr(162)), V(float32(162))},
        {V(float32(163)), V(uintptr(163))},
        {V(uintptr(164)), V(float64(164))},
        {V(float64(165)), V(uintptr(165))},
        {V(float32(166)), V(float32(166))},
        {V(float32(167)), V(float64(167))},
        {V(float64(168)), V(float32(168))},
        {V(float64(169)), V(float64(169))},

        // truncation
        {V(float64(1.5)), V(int(1))},

        // complex
        {V(complex64(1i)), V(complex64(1i))},
        {V(complex64(2i)), V(complex128(2i))},
        {V(complex128(3i)), V(complex64(3i))},
        {V(complex128(4i)), V(complex128(4i))},

        // string
        {V(string("hello")), V(string("hello"))},
        {V(string("bytes1")), V([]byte("bytes1"))},
        {V([]byte("bytes2")), V(string("bytes2"))},
        {V([]byte("bytes3")), V([]byte("bytes3"))},
        {V(string("runes♝")), V([]rune("runes♝"))},
        {V([]rune("runes♕")), V(string("runes♕"))},
        {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
        {V(int('a')), V(string("a"))},
        {V(int8('a')), V(string("a"))},
        {V(int16('a')), V(string("a"))},
        {V(int32('a')), V(string("a"))},
        {V(int64('a')), V(string("a"))},
        {V(uint('a')), V(string("a"))},
        {V(uint8('a')), V(string("a"))},
        {V(uint16('a')), V(string("a"))},
        {V(uint32('a')), V(string("a"))},
        {V(uint64('a')), V(string("a"))},
        {V(uintptr('a')), V(string("a"))},
        {V(int(-1)), V(string("\uFFFD"))},
        {V(int8(-2)), V(string("\uFFFD"))},
        {V(int16(-3)), V(string("\uFFFD"))},
        {V(int32(-4)), V(string("\uFFFD"))},
        {V(int64(-5)), V(string("\uFFFD"))},
        {V(uint(0x110001)), V(string("\uFFFD"))},
        {V(uint32(0x110002)), V(string("\uFFFD"))},
        {V(uint64(0x110003)), V(string("\uFFFD"))},
        {V(uintptr(0x110004)), V(string("\uFFFD"))},

        // named string
        {V(MyString("hello")), V(string("hello"))},
        {V(string("hello")), V(MyString("hello"))},
        {V(string("hello")), V(string("hello"))},
        {V(MyString("hello")), V(MyString("hello"))},
        {V(MyString("bytes1")), V([]byte("bytes1"))},
        {V([]byte("bytes2")), V(MyString("bytes2"))},
        {V([]byte("bytes3")), V([]byte("bytes3"))},
        {V(MyString("runes♝")), V([]rune("runes♝"))},
        {V([]rune("runes♕")), V(MyString("runes♕"))},
        {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
        {V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
        {V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
        {V(int('a')), V(MyString("a"))},
        {V(int8('a')), V(MyString("a"))},
        {V(int16('a')), V(MyString("a"))},
        {V(int32('a')), V(MyString("a"))},
        {V(int64('a')), V(MyString("a"))},
        {V(uint('a')), V(MyString("a"))},
        {V(uint8('a')), V(MyString("a"))},
        {V(uint16('a')), V(MyString("a"))},
        {V(uint32('a')), V(MyString("a"))},
        {V(uint64('a')), V(MyString("a"))},
        {V(uintptr('a')), V(MyString("a"))},
        {V(int(-1)), V(MyString("\uFFFD"))},
        {V(int8(-2)), V(MyString("\uFFFD"))},
        {V(int16(-3)), V(MyString("\uFFFD"))},
        {V(int32(-4)), V(MyString("\uFFFD"))},
        {V(int64(-5)), V(MyString("\uFFFD"))},
        {V(uint(0x110001)), V(MyString("\uFFFD"))},
        {V(uint32(0x110002)), V(MyString("\uFFFD"))},
        {V(uint64(0x110003)), V(MyString("\uFFFD"))},
        {V(uintptr(0x110004)), V(MyString("\uFFFD"))},

        // named []byte
        {V(string("bytes1")), V(MyBytes("bytes1"))},
        {V(MyBytes("bytes2")), V(string("bytes2"))},
        {V(MyBytes("bytes3")), V(MyBytes("bytes3"))},
        {V(MyString("bytes1")), V(MyBytes("bytes1"))},
        {V(MyBytes("bytes2")), V(MyString("bytes2"))},

        // named []rune
        {V(string("runes♝")), V(MyRunes("runes♝"))},
        {V(MyRunes("runes♕")), V(string("runes♕"))},
        {V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
        {V(MyString("runes♝")), V(MyRunes("runes♝"))},
        {V(MyRunes("runes♕")), V(MyString("runes♕"))},

        // named types and equal underlying types
        {V(new(int)), V(new(integer))},
        {V(new(integer)), V(new(int))},
        {V(Empty{}), V(struct{}{})},
        {V(new(Empty)), V(new(struct{}))},
        {V(struct{}{}), V(Empty{})},
        {V(new(struct{})), V(new(Empty))},
        {V(Empty{}), V(Empty{})},
        {V(MyBytes{}), V([]byte{})},
        {V([]byte{}), V(MyBytes{})},
        {V((func())(nil)), V(MyFunc(nil))},
        {V((MyFunc)(nil)), V((func())(nil))},

        // structs with different tags
        {V(struct {
                x int `some:"foo"`
        }{}), V(struct {
                x int `some:"bar"`
        }{})},

        {V(struct {
                x int `some:"bar"`
        }{}), V(struct {
                x int `some:"foo"`
        }{})},

        {V(MyStruct{}), V(struct {
                x int `some:"foo"`
        }{})},

        {V(struct {
                x int `some:"foo"`
        }{}), V(MyStruct{})},

        {V(MyStruct{}), V(struct {
                x int `some:"bar"`
        }{})},

        {V(struct {
                x int `some:"bar"`
        }{}), V(MyStruct{})},

        // can convert *byte and *MyByte
        {V((*byte)(nil)), V((*MyByte)(nil))},
        {V((*MyByte)(nil)), V((*byte)(nil))},

        // cannot convert mismatched array sizes
        {V([2]byte{}), V([2]byte{})},
        {V([3]byte{}), V([3]byte{})},

        // cannot convert other instances
        {V((**byte)(nil)), V((**byte)(nil))},
        {V((**MyByte)(nil)), V((**MyByte)(nil))},
        {V((chan byte)(nil)), V((chan byte)(nil))},
        {V((chan MyByte)(nil)), V((chan MyByte)(nil))},
        {V(([]byte)(nil)), V(([]byte)(nil))},
        {V(([]MyByte)(nil)), V(([]MyByte)(nil))},
        {V((map[int]byte)(nil)), V((map[int]byte)(nil))},
        {V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))},
        {V((map[byte]int)(nil)), V((map[byte]int)(nil))},
        {V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))},
        {V([2]byte{}), V([2]byte{})},
        {V([2]MyByte{}), V([2]MyByte{})},

        // other
        {V((***int)(nil)), V((***int)(nil))},
        {V((***byte)(nil)), V((***byte)(nil))},
        {V((***int32)(nil)), V((***int32)(nil))},
        {V((***int64)(nil)), V((***int64)(nil))},
        {V((chan int)(nil)), V((<-chan int)(nil))},
        {V((chan int)(nil)), V((chan<- int)(nil))},
        {V((chan string)(nil)), V((<-chan string)(nil))},
        {V((chan string)(nil)), V((chan<- string)(nil))},
        {V((chan byte)(nil)), V((chan byte)(nil))},
        {V((chan MyByte)(nil)), V((chan MyByte)(nil))},
        {V((map[int]bool)(nil)), V((map[int]bool)(nil))},
        {V((map[int]byte)(nil)), V((map[int]byte)(nil))},
        {V((map[uint]bool)(nil)), V((map[uint]bool)(nil))},
        {V([]uint(nil)), V([]uint(nil))},
        {V([]int(nil)), V([]int(nil))},
        {V(new(interface{})), V(new(interface{}))},
        {V(new(io.Reader)), V(new(io.Reader))},
        {V(new(io.Writer)), V(new(io.Writer))},

        // interfaces
        {V(int(1)), EmptyInterfaceV(int(1))},
        {V(string("hello")), EmptyInterfaceV(string("hello"))},
        {V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
        {ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
        {V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))},
}

func TestConvert(t *testing.T) {
        canConvert := map[[2]Type]bool{}
        all := map[Type]bool{}

        for _, tt := range convertTests {
                t1 := tt.in.Type()
                if !t1.ConvertibleTo(t1) {
                        t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1)
                        continue
                }

                t2 := tt.out.Type()
                if !t1.ConvertibleTo(t2) {
                        t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2)
                        continue
                }

                all[t1] = true
                all[t2] = true
                canConvert[[2]Type{t1, t2}] = true

                // vout1 represents the in value converted to the in type.
                v1 := tt.in
                vout1 := v1.Convert(t1)
                out1 := vout1.Interface()
                if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) {
                        t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t1, out1, tt.in.Interface())
                }

                // vout2 represents the in value converted to the out type.
                vout2 := v1.Convert(t2)
                out2 := vout2.Interface()
                if vout2.Type() != tt.out.Type() || !DeepEqual(out2, tt.out.Interface()) {
                        t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out2, tt.out.Interface())
                }

                // vout3 represents a new value of the out type, set to vout2.  This makes
                // sure the converted value vout2 is really usable as a regular value.
                vout3 := New(t2).Elem()
                vout3.Set(vout2)
                out3 := vout3.Interface()
                if vout3.Type() != tt.out.Type() || !DeepEqual(out3, tt.out.Interface()) {
                        t.Errorf("Set(ValueOf(%T(%[1]v)).Convert(%s)) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out3, tt.out.Interface())
                }

                if IsRO(v1) {
                        t.Errorf("table entry %v is RO, should not be", v1)
                }
                if IsRO(vout1) {
                        t.Errorf("self-conversion output %v is RO, should not be", vout1)
                }
                if IsRO(vout2) {
                        t.Errorf("conversion output %v is RO, should not be", vout2)
                }
                if IsRO(vout3) {
                        t.Errorf("set(conversion output) %v is RO, should not be", vout3)
                }
                if !IsRO(MakeRO(v1).Convert(t1)) {
                        t.Errorf("RO self-conversion output %v is not RO, should be", v1)
                }
                if !IsRO(MakeRO(v1).Convert(t2)) {
                        t.Errorf("RO conversion output %v is not RO, should be", v1)
                }
        }

        // Assume that of all the types we saw during the tests,
        // if there wasn't an explicit entry for a conversion between
        // a pair of types, then it's not to be allowed. This checks for
        // things like 'int64' converting to '*int'.
        for t1 := range all {
                for t2 := range all {
                        expectOK := t1 == t2 || canConvert[[2]Type{t1, t2}] || t2.Kind() == Interface && t2.NumMethod() == 0
                        if ok := t1.ConvertibleTo(t2); ok != expectOK {
                                t.Errorf("(%s).ConvertibleTo(%s) = %v, want %v", t1, t2, ok, expectOK)
                        }
                }
        }
}

type ComparableStruct struct {
        X int
}

type NonComparableStruct struct {
        X int
        Y map[string]int
}

var comparableTests = []struct {
        typ Type
        ok  bool
}{
        {TypeOf(1), true},
        {TypeOf("hello"), true},
        {TypeOf(new(byte)), true},
        {TypeOf((func())(nil)), false},
        {TypeOf([]byte{}), false},
        {TypeOf(map[string]int{}), false},
        {TypeOf(make(chan int)), true},
        {TypeOf(1.5), true},
        {TypeOf(false), true},
        {TypeOf(1i), true},
        {TypeOf(ComparableStruct{}), true},
        {TypeOf(NonComparableStruct{}), false},
        {TypeOf([10]map[string]int{}), false},
        {TypeOf([10]string{}), true},
        {TypeOf(new(interface{})).Elem(), true},
}

func TestComparable(t *testing.T) {
        for _, tt := range comparableTests {
                if ok := tt.typ.Comparable(); ok != tt.ok {
                        t.Errorf("TypeOf(%v).Comparable() = %v, want %v", tt.typ, ok, tt.ok)
                }
        }
}

func TestOverflow(t *testing.T) {
        if ovf := V(float64(0)).OverflowFloat(1e300); ovf {
                t.Errorf("%v wrongly overflows float64", 1e300)
        }

        maxFloat32 := float64((1<<24 - 1) << (127 - 23))
        if ovf := V(float32(0)).OverflowFloat(maxFloat32); ovf {
                t.Errorf("%v wrongly overflows float32", maxFloat32)
        }
        ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52))
        if ovf := V(float32(0)).OverflowFloat(ovfFloat32); !ovf {
                t.Errorf("%v should overflow float32", ovfFloat32)
        }
        if ovf := V(float32(0)).OverflowFloat(-ovfFloat32); !ovf {
                t.Errorf("%v should overflow float32", -ovfFloat32)
        }

        maxInt32 := int64(0x7fffffff)
        if ovf := V(int32(0)).OverflowInt(maxInt32); ovf {
                t.Errorf("%v wrongly overflows int32", maxInt32)
        }
        if ovf := V(int32(0)).OverflowInt(-1 << 31); ovf {
                t.Errorf("%v wrongly overflows int32", -int64(1)<<31)
        }
        ovfInt32 := int64(1 << 31)
        if ovf := V(int32(0)).OverflowInt(ovfInt32); !ovf {
                t.Errorf("%v should overflow int32", ovfInt32)
        }

        maxUint32 := uint64(0xffffffff)
        if ovf := V(uint32(0)).OverflowUint(maxUint32); ovf {
                t.Errorf("%v wrongly overflows uint32", maxUint32)
        }
        ovfUint32 := uint64(1 << 32)
        if ovf := V(uint32(0)).OverflowUint(ovfUint32); !ovf {
                t.Errorf("%v should overflow uint32", ovfUint32)
        }
}

func checkSameType(t *testing.T, x Type, y interface{}) {
        if x != TypeOf(y) || TypeOf(Zero(x).Interface()) != TypeOf(y) {
                t.Errorf("did not find preexisting type for %s (vs %s)", TypeOf(x), TypeOf(y))
        }
}

func TestArrayOf(t *testing.T) {
        // check construction and use of type not in binary
        tests := []struct {
                n          int
                value      func(i int) interface{}
                comparable bool
                want       string
        }{
                {
                        n:          0,
                        value:      func(i int) interface{} { type Tint int; return Tint(i) },
                        comparable: true,
                        want:       "[]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tint int; return Tint(i) },
                        comparable: true,
                        want:       "[0 1 2 3 4 5 6 7 8 9]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tfloat float64; return Tfloat(i) },
                        comparable: true,
                        want:       "[0 1 2 3 4 5 6 7 8 9]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tstring string; return Tstring(strconv.Itoa(i)) },
                        comparable: true,
                        want:       "[0 1 2 3 4 5 6 7 8 9]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tstruct struct{ V int }; return Tstruct{i} },
                        comparable: true,
                        want:       "[{0} {1} {2} {3} {4} {5} {6} {7} {8} {9}]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tint int; return []Tint{Tint(i)} },
                        comparable: false,
                        want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tint int; return [1]Tint{Tint(i)} },
                        comparable: true,
                        want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tstruct struct{ V [1]int }; return Tstruct{[1]int{i}} },
                        comparable: true,
                        want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type Tstruct struct{ V []int }; return Tstruct{[]int{i}} },
                        comparable: false,
                        want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
                },
                {
                        n:          10,
                        value:      func(i int) interface{} { type TstructUV struct{ U, V int }; return TstructUV{i, i} },
                        comparable: true,
                        want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
                },
                {
                        n: 10,
                        value: func(i int) interface{} {
                                type TstructUV struct {
                                        U int
                                        V float64
                                }
                                return TstructUV{i, float64(i)}
                        },
                        comparable: true,
                        want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
                },
        }

        for _, table := range tests {
                at := ArrayOf(table.n, TypeOf(table.value(0)))
                v := New(at).Elem()
                vok := New(at).Elem()
                vnot := New(at).Elem()
                for i := 0; i < v.Len(); i++ {
                        v.Index(i).Set(ValueOf(table.value(i)))
                        vok.Index(i).Set(ValueOf(table.value(i)))
                        j := i
                        if i+1 == v.Len() {
                                j = i + 1
                        }
                        vnot.Index(i).Set(ValueOf(table.value(j))) // make it differ only by last element
                }
                s := fmt.Sprint(v.Interface())
                if s != table.want {
                        t.Errorf("constructed array = %s, want %s", s, table.want)
                }

                if table.comparable != at.Comparable() {
                        t.Errorf("constructed array (%#v) is comparable=%v, want=%v", v.Interface(), at.Comparable(), table.comparable)
                }
                if table.comparable {
                        if table.n > 0 {
                                if DeepEqual(vnot.Interface(), v.Interface()) {
                                        t.Errorf(
                                                "arrays (%#v) compare ok (but should not)",
                                                v.Interface(),
                                        )
                                }
                        }
                        if !DeepEqual(vok.Interface(), v.Interface()) {
                                t.Errorf(
                                        "arrays (%#v) compare NOT-ok (but should)",
                                        v.Interface(),
                                )
                        }
                }
        }

        // check that type already in binary is found
        type T int
        checkSameType(t, ArrayOf(5, TypeOf(T(1))), [5]T{})
}

func TestArrayOfGC(t *testing.T) {
        type T *uintptr
        tt := TypeOf(T(nil))
        const n = 100
        var x []interface{}
        for i := 0; i < n; i++ {
                v := New(ArrayOf(n, tt)).Elem()
                for j := 0; j < v.Len(); j++ {
                        p := new(uintptr)
                        *p = uintptr(i*n + j)
                        v.Index(j).Set(ValueOf(p).Convert(tt))
                }
                x = append(x, v.Interface())
        }
        runtime.GC()

        for i, xi := range x {
                v := ValueOf(xi)
                for j := 0; j < v.Len(); j++ {
                        k := v.Index(j).Elem().Interface()
                        if k != uintptr(i*n+j) {
                                t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
                        }
                }
        }
}

func TestArrayOfAlg(t *testing.T) {
        at := ArrayOf(6, TypeOf(byte(0)))
        v1 := New(at).Elem()
        v2 := New(at).Elem()
        if v1.Interface() != v1.Interface() {
                t.Errorf("constructed array %v not equal to itself", v1.Interface())
        }
        v1.Index(5).Set(ValueOf(byte(1)))
        if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
                t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
        }

        at = ArrayOf(6, TypeOf([]int(nil)))
        v1 = New(at).Elem()
        shouldPanic(func() { _ = v1.Interface() == v1.Interface() })
}

func TestArrayOfGenericAlg(t *testing.T) {
        at1 := ArrayOf(5, TypeOf(string("")))
        at := ArrayOf(6, at1)
        v1 := New(at).Elem()
        v2 := New(at).Elem()
        if v1.Interface() != v1.Interface() {
                t.Errorf("constructed array %v not equal to itself", v1.Interface())
        }

        v1.Index(0).Index(0).Set(ValueOf("abc"))
        v2.Index(0).Index(0).Set(ValueOf("efg"))
        if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
                t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
        }

        v1.Index(0).Index(0).Set(ValueOf("abc"))
        v2.Index(0).Index(0).Set(ValueOf((v1.Index(0).Index(0).String() + " ")[:3]))
        if i1, i2 := v1.Interface(), v2.Interface(); i1 != i2 {
                t.Errorf("constructed arrays %v and %v should be equal", i1, i2)
        }

        // Test hash
        m := MakeMap(MapOf(at, TypeOf(int(0))))
        m.SetMapIndex(v1, ValueOf(1))
        if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
                t.Errorf("constructed arrays %v and %v have different hashes", i1, i2)
        }
}

func TestArrayOfDirectIface(t *testing.T) {
        t.Skip("skipping test because gccgo uses a different directiface value")
        {
                type T [1]*byte
                i1 := Zero(TypeOf(T{})).Interface()
                v1 := ValueOf(&i1).Elem()
                p1 := v1.InterfaceData()[1]

                i2 := Zero(ArrayOf(1, PtrTo(TypeOf(int8(0))))).Interface()
                v2 := ValueOf(&i2).Elem()
                p2 := v2.InterfaceData()[1]

                if p1 != 0 {
                        t.Errorf("got p1=%v. want=%v", p1, nil)
                }

                if p2 != 0 {
                        t.Errorf("got p2=%v. want=%v", p2, nil)
                }
        }
        {
                type T [0]*byte
                i1 := Zero(TypeOf(T{})).Interface()
                v1 := ValueOf(&i1).Elem()
                p1 := v1.InterfaceData()[1]

                i2 := Zero(ArrayOf(0, PtrTo(TypeOf(int8(0))))).Interface()
                v2 := ValueOf(&i2).Elem()
                p2 := v2.InterfaceData()[1]

                if p1 == 0 {
                        t.Errorf("got p1=%v. want=not-%v", p1, nil)
                }

                if p2 == 0 {
                        t.Errorf("got p2=%v. want=not-%v", p2, nil)
                }
        }
}

func TestSliceOf(t *testing.T) {
        // check construction and use of type not in binary
        type T int
        st := SliceOf(TypeOf(T(1)))
        if got, want := st.String(), "[]reflect_test.T"; got != want {
                t.Errorf("SliceOf(T(1)).String()=%q, want %q", got, want)
        }
        v := MakeSlice(st, 10, 10)
        runtime.GC()
        for i := 0; i < v.Len(); i++ {
                v.Index(i).Set(ValueOf(T(i)))
                runtime.GC()
        }
        s := fmt.Sprint(v.Interface())
        want := "[0 1 2 3 4 5 6 7 8 9]"
        if s != want {
                t.Errorf("constructed slice = %s, want %s", s, want)
        }

        // check that type already in binary is found
        type T1 int
        checkSameType(t, SliceOf(TypeOf(T1(1))), []T1{})
}

func TestSliceOverflow(t *testing.T) {
        // check that MakeSlice panics when size of slice overflows uint
        const S = 1e6
        s := uint(S)
        l := (1<<(unsafe.Sizeof((*byte)(nil))*8)-1)/s + 1
        if l*s >= s {
                t.Fatal("slice size does not overflow")
        }
        var x [S]byte
        st := SliceOf(TypeOf(x))
        defer func() {
                err := recover()
                if err == nil {
                        t.Fatal("slice overflow does not panic")
                }
        }()
        MakeSlice(st, int(l), int(l))
}

func TestSliceOfGC(t *testing.T) {
        type T *uintptr
        tt := TypeOf(T(nil))
        st := SliceOf(tt)
        const n = 100
        var x []interface{}
        for i := 0; i < n; i++ {
                v := MakeSlice(st, n, n)
                for j := 0; j < v.Len(); j++ {
                        p := new(uintptr)
                        *p = uintptr(i*n + j)
                        v.Index(j).Set(ValueOf(p).Convert(tt))
                }
                x = append(x, v.Interface())
        }
        runtime.GC()

        for i, xi := range x {
                v := ValueOf(xi)
                for j := 0; j < v.Len(); j++ {
                        k := v.Index(j).Elem().Interface()
                        if k != uintptr(i*n+j) {
                                t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
                        }
                }
        }
}

func TestStructOfFieldName(t *testing.T) {
        // invalid field name "1nvalid"
        shouldPanic(func() {
                StructOf([]StructField{
                        StructField{Name: "valid", Type: TypeOf("")},
                        StructField{Name: "1nvalid", Type: TypeOf("")},
                })
        })

        // invalid field name "+"
        shouldPanic(func() {
                StructOf([]StructField{
                        StructField{Name: "val1d", Type: TypeOf("")},
                        StructField{Name: "+", Type: TypeOf("")},
                })
        })

        // no field name
        shouldPanic(func() {
                StructOf([]StructField{
                        StructField{Name: "", Type: TypeOf("")},
                })
        })

        // verify creation of a struct with valid struct fields
        validFields := []StructField{
                StructField{
                        Name: "φ",
                        Type: TypeOf(""),
                },
                StructField{
                        Name: "ValidName",
                        Type: TypeOf(""),
                },
                StructField{
                        Name: "Val1dNam5",
                        Type: TypeOf(""),
                },
        }

        validStruct := StructOf(validFields)

        const structStr = `struct { φ string; ValidName string; Val1dNam5 string }`
        if got, want := validStruct.String(), structStr; got != want {
                t.Errorf("StructOf(validFields).String()=%q, want %q", got, want)
        }
}

func TestStructOf(t *testing.T) {
        // check construction and use of type not in binary
        fields := []StructField{
                StructField{
                        Name: "S",
                        Tag:  "s",
                        Type: TypeOf(""),
                },
                StructField{
                        Name: "X",
                        Tag:  "x",
                        Type: TypeOf(byte(0)),
                },
                StructField{
                        Name: "Y",
                        Type: TypeOf(uint64(0)),
                },
                StructField{
                        Name: "Z",
                        Type: TypeOf([3]uint16{}),
                },
        }

        st := StructOf(fields)
        v := New(st).Elem()
        runtime.GC()
        v.FieldByName("X").Set(ValueOf(byte(2)))
        v.FieldByIndex([]int{1}).Set(ValueOf(byte(1)))
        runtime.GC()

        s := fmt.Sprint(v.Interface())
        want := `{ 1 0 [0 0 0]}`
        if s != want {
                t.Errorf("constructed struct = %s, want %s", s, want)
        }
        const stStr = `struct { S string "s"; X uint8 "x"; Y uint64; Z [3]uint16 }`
        if got, want := st.String(), stStr; got != want {
                t.Errorf("StructOf(fields).String()=%q, want %q", got, want)
        }

        // check the size, alignment and field offsets
        stt := TypeOf(struct {
                String string
                X      byte
                Y      uint64
                Z      [3]uint16
        }{})
        if st.Size() != stt.Size() {
                t.Errorf("constructed struct size = %v, want %v", st.Size(), stt.Size())
        }
        if st.Align() != stt.Align() {
                t.Errorf("constructed struct align = %v, want %v", st.Align(), stt.Align())
        }
        if st.FieldAlign() != stt.FieldAlign() {
                t.Errorf("constructed struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign())
        }
        for i := 0; i < st.NumField(); i++ {
                o1 := st.Field(i).Offset
                o2 := stt.Field(i).Offset
                if o1 != o2 {
                        t.Errorf("constructed struct field %v offset = %v, want %v", i, o1, o2)
                }
        }

        // Check size and alignment with a trailing zero-sized field.
        st = StructOf([]StructField{
                {
                        Name: "F1",
                        Type: TypeOf(byte(0)),
                },
                {
                        Name: "F2",
                        Type: TypeOf([0]*byte{}),
                },
        })
        stt = TypeOf(struct {
                G1 byte
                G2 [0]*byte
        }{})
        // Broken with gccgo for now--gccgo does not pad structs yet.
        // if st.Size() != stt.Size() {
        //      t.Errorf("constructed zero-padded struct size = %v, want %v", st.Size(), stt.Size())
        // }
        if st.Align() != stt.Align() {
                t.Errorf("constructed zero-padded struct align = %v, want %v", st.Align(), stt.Align())
        }
        if st.FieldAlign() != stt.FieldAlign() {
                t.Errorf("constructed zero-padded struct field align = %v, want %v", st.FieldAlign(), stt.FieldAlign())
        }
        for i := 0; i < st.NumField(); i++ {
                o1 := st.Field(i).Offset
                o2 := stt.Field(i).Offset
                if o1 != o2 {
                        t.Errorf("constructed zero-padded struct field %v offset = %v, want %v", i, o1, o2)
                }
        }

        // check duplicate names
        shouldPanic(func() {
                StructOf([]StructField{
                        StructField{Name: "string", Type: TypeOf("")},
                        StructField{Name: "string", Type: TypeOf("")},
                })
        })
        shouldPanic(func() {
                StructOf([]StructField{
                        StructField{Type: TypeOf("")},
                        StructField{Name: "string", Type: TypeOf("")},
                })
        })
        shouldPanic(func() {
                StructOf([]StructField{
                        StructField{Type: TypeOf("")},
                        StructField{Type: TypeOf("")},
                })
        })
        // check that type already in binary is found
        checkSameType(t, StructOf(fields[2:3]), struct{ Y uint64 }{})

        // gccgo used to fail this test.
        type structFieldType interface{}
        checkSameType(t,
                StructOf([]StructField{
                        StructField{
                                Name: "F",
                                Type: TypeOf((*structFieldType)(nil)).Elem(),
                        },
                }),
                struct{ F structFieldType }{})
}

func TestStructOfExportRules(t *testing.T) {
        type S1 struct{}
        type s2 struct{}
        type ΦType struct{}
        type φType struct{}

        testPanic := func(i int, mustPanic bool, f func()) {
                defer func() {
                        err := recover()
                        if err == nil && mustPanic {
                                t.Errorf("test-%d did not panic", i)
                        }
                        if err != nil && !mustPanic {
                                t.Errorf("test-%d panicked: %v\n", i, err)
                        }
                }()
                f()
        }

        tests := []struct {
                field     StructField
                mustPanic bool
                exported  bool
        }{
                {
                        field:    StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{})},
                        exported: true,
                },
                {
                        field:    StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil))},
                        exported: true,
                },
                {
                        field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{})},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil))},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "Name", Type: nil, PkgPath: ""},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "", Type: TypeOf(S1{}), PkgPath: ""},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "S1", Anonymous: true, Type: TypeOf(S1{}), PkgPath: "other/pkg"},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "S1", Anonymous: true, Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf(s2{}), PkgPath: "other/pkg"},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s2", Anonymous: true, Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s2", Type: TypeOf(int(0)), PkgPath: "other/pkg"},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "S", Type: TypeOf(S1{})},
                        mustPanic: false,
                        exported:  true,
                },
                {
                        field:    StructField{Name: "S", Type: TypeOf((*S1)(nil))},
                        exported: true,
                },
                {
                        field:    StructField{Name: "S", Type: TypeOf(s2{})},
                        exported: true,
                },
                {
                        field:    StructField{Name: "S", Type: TypeOf((*s2)(nil))},
                        exported: true,
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf(S1{})},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf((*S1)(nil))},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf(s2{})},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf((*s2)(nil))},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf(S1{}), PkgPath: "other/pkg"},
                        mustPanic: true, // TODO(sbinet): creating a name with a package path
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf((*S1)(nil)), PkgPath: "other/pkg"},
                        mustPanic: true, // TODO(sbinet): creating a name with a package path
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf(s2{}), PkgPath: "other/pkg"},
                        mustPanic: true, // TODO(sbinet): creating a name with a package path
                },
                {
                        field:     StructField{Name: "s", Type: TypeOf((*s2)(nil)), PkgPath: "other/pkg"},
                        mustPanic: true, // TODO(sbinet): creating a name with a package path
                },
                {
                        field:     StructField{Name: "", Type: TypeOf(ΦType{})},
                        mustPanic: true,
                },
                {
                        field:     StructField{Name: "", Type: TypeOf(φType{})},
                        mustPanic: true,
                },
                {
                        field:    StructField{Name: "Φ", Type: TypeOf(0)},
                        exported: true,
                },
                {
                        field:    StructField{Name: "φ", Type: TypeOf(0)},
                        exported: false,
                },
        }

        for i, test := range tests {
                testPanic(i, test.mustPanic, func() {
                        typ := StructOf([]StructField{test.field})
                        if typ == nil {
                                t.Errorf("test-%d: error creating struct type", i)
                                return
                        }
                        field := typ.Field(0)
                        n := field.Name
                        if n == "" {
                                panic("field.Name must not be empty")
                        }
                        exported := isExported(n)
                        if exported != test.exported {
                                t.Errorf("test-%d: got exported=%v want exported=%v", i, exported, test.exported)
                        }
                })
        }
}

// isExported reports whether name is an exported Go symbol
// (that is, whether it begins with an upper-case letter).
//
func isExported(name string) bool {
        ch, _ := utf8.DecodeRuneInString(name)
        return unicode.IsUpper(ch)
}

func TestStructOfGC(t *testing.T) {
        type T *uintptr
        tt := TypeOf(T(nil))
        fields := []StructField{
                {Name: "X", Type: tt},
                {Name: "Y", Type: tt},
        }
        st := StructOf(fields)

        const n = 10000
        var x []interface{}
        for i := 0; i < n; i++ {
                v := New(st).Elem()
                for j := 0; j < v.NumField(); j++ {
                        p := new(uintptr)
                        *p = uintptr(i*n + j)
                        v.Field(j).Set(ValueOf(p).Convert(tt))
                }
                x = append(x, v.Interface())
        }
        runtime.GC()

        for i, xi := range x {
                v := ValueOf(xi)
                for j := 0; j < v.NumField(); j++ {
                        k := v.Field(j).Elem().Interface()
                        if k != uintptr(i*n+j) {
                                t.Errorf("lost x[%d].%c = %d, want %d", i, "XY"[j], k, i*n+j)
                        }
                }
        }
}

func TestStructOfAlg(t *testing.T) {
        st := StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf(int(0))}})
        v1 := New(st).Elem()
        v2 := New(st).Elem()
        if !DeepEqual(v1.Interface(), v1.Interface()) {
                t.Errorf("constructed struct %v not equal to itself", v1.Interface())
        }
        v1.FieldByName("X").Set(ValueOf(int(1)))
        if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) {
                t.Errorf("constructed structs %v and %v should not be equal", i1, i2)
        }

        st = StructOf([]StructField{{Name: "X", Tag: "x", Type: TypeOf([]int(nil))}})
        v1 = New(st).Elem()
        shouldPanic(func() { _ = v1.Interface() == v1.Interface() })
}

func TestStructOfGenericAlg(t *testing.T) {
        st1 := StructOf([]StructField{
                {Name: "X", Tag: "x", Type: TypeOf(int64(0))},
                {Name: "Y", Type: TypeOf(string(""))},
        })
        st := StructOf([]StructField{
                {Name: "S0", Type: st1},
                {Name: "S1", Type: st1},
        })

        tests := []struct {
                rt  Type
                idx []int
        }{
                {
                        rt:  st,
                        idx: []int{0, 1},
                },
                {
                        rt:  st1,
                        idx: []int{1},
                },
                {
                        rt: StructOf(
                                []StructField{
                                        {Name: "XX", Type: TypeOf([0]int{})},
                                        {Name: "YY", Type: TypeOf("")},
                                },
                        ),
                        idx: []int{1},
                },
                {
                        rt: StructOf(
                                []StructField{
                                        {Name: "XX", Type: TypeOf([0]int{})},
                                        {Name: "YY", Type: TypeOf("")},
                                        {Name: "ZZ", Type: TypeOf([2]int{})},
                                },
                        ),
                        idx: []int{1},
                },
                {
                        rt: StructOf(
                                []StructField{
                                        {Name: "XX", Type: TypeOf([1]int{})},
                                        {Name: "YY", Type: TypeOf("")},
                                },
                        ),
                        idx: []int{1},
                },
                {
                        rt: StructOf(
                                []StructField{
                                        {Name: "XX", Type: TypeOf([1]int{})},
                                        {Name: "YY", Type: TypeOf("")},
                                        {Name: "ZZ", Type: TypeOf([1]int{})},
                                },
                        ),
                        idx: []int{1},
                },
                {
                        rt: StructOf(
                                []StructField{
                                        {Name: "XX", Type: TypeOf([2]int{})},
                                        {Name: "YY", Type: TypeOf("")},
                                        {Name: "ZZ", Type: TypeOf([2]int{})},
                                },
                        ),
                        idx: []int{1},
                },
                {
                        rt: StructOf(
                                []StructField{
                                        {Name: "XX", Type: TypeOf(int64(0))},
                                        {Name: "YY", Type: TypeOf(byte(0))},
                                        {Name: "ZZ", Type: TypeOf("")},
                                },
                        ),
                        idx: []int{2},
                },
                {
                        rt: StructOf(
                                []StructField{
                                        {Name: "XX", Type: TypeOf(int64(0))},
                                        {Name: "YY", Type: TypeOf(int64(0))},
                                        {Name: "ZZ", Type: TypeOf("")},
                                        {Name: "AA", Type: TypeOf([1]int64{})},
                                },
                        ),
                        idx: []int{2},
                },
        }

        for _, table := range tests {
                v1 := New(table.rt).Elem()
                v2 := New(table.rt).Elem()

                if !DeepEqual(v1.Interface(), v1.Interface()) {
                        t.Errorf("constructed struct %v not equal to itself", v1.Interface())
                }

                v1.FieldByIndex(table.idx).Set(ValueOf("abc"))
                v2.FieldByIndex(table.idx).Set(ValueOf("def"))
                if i1, i2 := v1.Interface(), v2.Interface(); DeepEqual(i1, i2) {
                        t.Errorf("constructed structs %v and %v should not be equal", i1, i2)
                }

                abc := "abc"
                v1.FieldByIndex(table.idx).Set(ValueOf(abc))
                val := "+" + abc + "-"
                v2.FieldByIndex(table.idx).Set(ValueOf(val[1:4]))
                if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) {
                        t.Errorf("constructed structs %v and %v should be equal", i1, i2)
                }

                // Test hash
                m := MakeMap(MapOf(table.rt, TypeOf(int(0))))
                m.SetMapIndex(v1, ValueOf(1))
                if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
                        t.Errorf("constructed structs %#v and %#v have different hashes", i1, i2)
                }

                v2.FieldByIndex(table.idx).Set(ValueOf("abc"))
                if i1, i2 := v1.Interface(), v2.Interface(); !DeepEqual(i1, i2) {
                        t.Errorf("constructed structs %v and %v should be equal", i1, i2)
                }

                if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
                        t.Errorf("constructed structs %v and %v have different hashes", i1, i2)
                }
        }
}

/*
gccgo does not use the same directiface settings as gc.

func TestStructOfDirectIface(t *testing.T) {
        {
                type T struct{ X [1]*byte }
                i1 := Zero(TypeOf(T{})).Interface()
                v1 := ValueOf(&i1).Elem()
                p1 := v1.InterfaceData()[1]

                i2 := Zero(StructOf([]StructField{
                        {
                                Name: "X",
                                Type: ArrayOf(1, TypeOf((*int8)(nil))),
                        },
                })).Interface()
                v2 := ValueOf(&i2).Elem()
                p2 := v2.InterfaceData()[1]

                if p1 != 0 {
                        t.Errorf("got p1=%v. want=%v", p1, nil)
                }

                if p2 != 0 {
                        t.Errorf("got p2=%v. want=%v", p2, nil)
                }
        }
        {
                type T struct{ X [0]*byte }
                i1 := Zero(TypeOf(T{})).Interface()
                v1 := ValueOf(&i1).Elem()
                p1 := v1.InterfaceData()[1]

                i2 := Zero(StructOf([]StructField{
                        {
                                Name: "X",
                                Type: ArrayOf(0, TypeOf((*int8)(nil))),
                        },
                })).Interface()
                v2 := ValueOf(&i2).Elem()
                p2 := v2.InterfaceData()[1]

                if p1 == 0 {
                        t.Errorf("got p1=%v. want=not-%v", p1, nil)
                }

                if p2 == 0 {
                        t.Errorf("got p2=%v. want=not-%v", p2, nil)
                }
        }
}
*/

type StructI int

func (i StructI) Get() int { return int(i) }

type StructIPtr int

func (i *StructIPtr) Get() int { return int(*i) }

/*
gccgo does not yet support StructOf with methods.

func TestStructOfWithInterface(t *testing.T) {
        const want = 42
        type Iface interface {
                Get() int
        }
        tests := []struct {
                name string
                typ  Type
                val  Value
                impl bool
        }{
                {
                        name: "StructI",
                        typ:  TypeOf(StructI(want)),
                        val:  ValueOf(StructI(want)),
                        impl: true,
                },
                {
                        name: "StructI",
                        typ:  PtrTo(TypeOf(StructI(want))),
                        val: ValueOf(func() interface{} {
                                v := StructI(want)
                                return &v
                        }()),
                        impl: true,
                },
                {
                        name: "StructIPtr",
                        typ:  PtrTo(TypeOf(StructIPtr(want))),
                        val: ValueOf(func() interface{} {
                                v := StructIPtr(want)
                                return &v
                        }()),
                        impl: true,
                },
                {
                        name: "StructIPtr",
                        typ:  TypeOf(StructIPtr(want)),
                        val:  ValueOf(StructIPtr(want)),
                        impl: false,
                },
                // {
                //      typ:  TypeOf((*Iface)(nil)).Elem(), // FIXME(sbinet): fix method.ifn/tfn
                //      val:  ValueOf(StructI(want)),
                //      impl: true,
                // },
        }

        for i, table := range tests {
                for j := 0; j < 2; j++ {
                        var fields []StructField
                        if j == 1 {
                                fields = append(fields, StructField{
                                        Name:    "Dummy",
                                        PkgPath: "",
                                        Type:    TypeOf(int(0)),
                                })
                        }
                        fields = append(fields, StructField{
                                Name:      table.name,
                                Anonymous: true,
                                PkgPath:   "",
                                Type:      table.typ,
                        })

                        // We currently do not correctly implement methods
                        // for anonymous fields other than the first.
                        // Therefore, for now, we expect those methods
                        // to not exist.  See issues 15924 and 20824.
                        // When those issues are fixed, this test of panic
                        // should be removed.
                        if j == 1 && table.impl {
                                func() {
                                        defer func() {
                                                if err := recover(); err == nil {
                                                        t.Errorf("test-%d-%d did not panic", i, j)
                                                }
                                        }()
                                        _ = StructOf(fields)
                                }()
                                continue
                        }

                        rt := StructOf(fields)
                        rv := New(rt).Elem()
                        rv.Field(j).Set(table.val)

                        if _, ok := rv.Interface().(Iface); ok != table.impl {
                                if table.impl {
                                        t.Errorf("test-%d-%d: type=%v fails to implement Iface.\n", i, j, table.typ)
                                } else {
                                        t.Errorf("test-%d-%d: type=%v should NOT implement Iface\n", i, j, table.typ)
                                }
                                continue
                        }

                        if !table.impl {
                                continue
                        }

                        v := rv.Interface().(Iface).Get()
                        if v != want {
                                t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, v, want)
                        }

                        fct := rv.MethodByName("Get")
                        out := fct.Call(nil)
                        if !DeepEqual(out[0].Interface(), want) {
                                t.Errorf("test-%d-%d: x.Get()=%v. want=%v\n", i, j, out[0].Interface(), want)
                        }
                }
        }
}
*/

func TestChanOf(t *testing.T) {
        // check construction and use of type not in binary
        type T string
        ct := ChanOf(BothDir, TypeOf(T("")))
        v := MakeChan(ct, 2)
        runtime.GC()
        v.Send(ValueOf(T("hello")))
        runtime.GC()
        v.Send(ValueOf(T("world")))
        runtime.GC()

        sv1, _ := v.Recv()
        sv2, _ := v.Recv()
        s1 := sv1.String()
        s2 := sv2.String()
        if s1 != "hello" || s2 != "world" {
                t.Errorf("constructed chan: have %q, %q, want %q, %q", s1, s2, "hello", "world")
        }

        // check that type already in binary is found
        type T1 int
        checkSameType(t, ChanOf(BothDir, TypeOf(T1(1))), (chan T1)(nil))
}

func TestChanOfDir(t *testing.T) {
        // check construction and use of type not in binary
        type T string
        crt := ChanOf(RecvDir, TypeOf(T("")))
        cst := ChanOf(SendDir, TypeOf(T("")))

        // check that type already in binary is found
        type T1 int
        checkSameType(t, ChanOf(RecvDir, TypeOf(T1(1))), (<-chan T1)(nil))
        checkSameType(t, ChanOf(SendDir, TypeOf(T1(1))), (chan<- T1)(nil))

        // check String form of ChanDir
        if crt.ChanDir().String() != "<-chan" {
                t.Errorf("chan dir: have %q, want %q", crt.ChanDir().String(), "<-chan")
        }
        if cst.ChanDir().String() != "chan<-" {
                t.Errorf("chan dir: have %q, want %q", cst.ChanDir().String(), "chan<-")
        }
}

func TestChanOfGC(t *testing.T) {
        done := make(chan bool, 1)
        go func() {
                select {
                case <-done:
                case <-time.After(5 * time.Second):
                        panic("deadlock in TestChanOfGC")
                }
        }()

        defer func() {
                done <- true
        }()

        type T *uintptr
        tt := TypeOf(T(nil))
        ct := ChanOf(BothDir, tt)

        // NOTE: The garbage collector handles allocated channels specially,
        // so we have to save pointers to channels in x; the pointer code will
        // use the gc info in the newly constructed chan type.
        const n = 100
        var x []interface{}
        for i := 0; i < n; i++ {
                v := MakeChan(ct, n)
                for j := 0; j < n; j++ {
                        p := new(uintptr)
                        *p = uintptr(i*n + j)
                        v.Send(ValueOf(p).Convert(tt))
                }
                pv := New(ct)
                pv.Elem().Set(v)
                x = append(x, pv.Interface())
        }
        runtime.GC()

        for i, xi := range x {
                v := ValueOf(xi).Elem()
                for j := 0; j < n; j++ {
                        pv, _ := v.Recv()
                        k := pv.Elem().Interface()
                        if k != uintptr(i*n+j) {
                                t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
                        }
                }
        }
}

func TestMapOf(t *testing.T) {
        // check construction and use of type not in binary
        type K string
        type V float64

        v := MakeMap(MapOf(TypeOf(K("")), TypeOf(V(0))))
        runtime.GC()
        v.SetMapIndex(ValueOf(K("a")), ValueOf(V(1)))
        runtime.GC()

        s := fmt.Sprint(v.Interface())
        want := "map[a:1]"
        if s != want {
                t.Errorf("constructed map = %s, want %s", s, want)
        }

        // check that type already in binary is found
        checkSameType(t, MapOf(TypeOf(V(0)), TypeOf(K(""))), map[V]K(nil))

        // check that invalid key type panics
        shouldPanic(func() { MapOf(TypeOf((func())(nil)), TypeOf(false)) })
}

func TestMapOfGCKeys(t *testing.T) {
        type T *uintptr
        tt := TypeOf(T(nil))
        mt := MapOf(tt, TypeOf(false))

        // NOTE: The garbage collector handles allocated maps specially,
        // so we have to save pointers to maps in x; the pointer code will
        // use the gc info in the newly constructed map type.
        const n = 100
        var x []interface{}
        for i := 0; i < n; i++ {
                v := MakeMap(mt)
                for j := 0; j < n; j++ {
                        p := new(uintptr)
                        *p = uintptr(i*n + j)
                        v.SetMapIndex(ValueOf(p).Convert(tt), ValueOf(true))
                }
                pv := New(mt)
                pv.Elem().Set(v)
                x = append(x, pv.Interface())
        }
        runtime.GC()

        for i, xi := range x {
                v := ValueOf(xi).Elem()
                var out []int
                for _, kv := range v.MapKeys() {
                        out = append(out, int(kv.Elem().Interface().(uintptr)))
                }
                sort.Ints(out)
                for j, k := range out {
                        if k != i*n+j {
                                t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
                        }
                }
        }
}

func TestMapOfGCValues(t *testing.T) {
        type T *uintptr
        tt := TypeOf(T(nil))
        mt := MapOf(TypeOf(1), tt)

        // NOTE: The garbage collector handles allocated maps specially,
        // so we have to save pointers to maps in x; the pointer code will
        // use the gc info in the newly constructed map type.
        const n = 100
        var x []interface{}
        for i := 0; i < n; i++ {
                v := MakeMap(mt)
                for j := 0; j < n; j++ {
                        p := new(uintptr)
                        *p = uintptr(i*n + j)
                        v.SetMapIndex(ValueOf(j), ValueOf(p).Convert(tt))
                }
                pv := New(mt)
                pv.Elem().Set(v)
                x = append(x, pv.Interface())
        }
        runtime.GC()

        for i, xi := range x {
                v := ValueOf(xi).Elem()
                for j := 0; j < n; j++ {
                        k := v.MapIndex(ValueOf(j)).Elem().Interface().(uintptr)
                        if k != uintptr(i*n+j) {
                                t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
                        }
                }
        }
}

func TestTypelinksSorted(t *testing.T) {
        var last string
        for i, n := range TypeLinks() {
                if n < last {
                        t.Errorf("typelinks not sorted: %q [%d] > %q [%d]", last, i-1, n, i)
                }
                last = n
        }
}

func TestFuncOf(t *testing.T) {
        // check construction and use of type not in binary
        type K string
        type V float64

        fn := func(args []Value) []Value {
                if len(args) != 1 {
                        t.Errorf("args == %v, want exactly one arg", args)
                } else if args[0].Type() != TypeOf(K("")) {
                        t.Errorf("args[0] is type %v, want %v", args[0].Type(), TypeOf(K("")))
                } else if args[0].String() != "gopher" {
                        t.Errorf("args[0] = %q, want %q", args[0].String(), "gopher")
                }
                return []Value{ValueOf(V(3.14))}
        }
        v := MakeFunc(FuncOf([]Type{TypeOf(K(""))}, []Type{TypeOf(V(0))}, false), fn)

        outs := v.Call([]Value{ValueOf(K("gopher"))})
        if len(outs) != 1 {
                t.Fatalf("v.Call returned %v, want exactly one result", outs)
        } else if outs[0].Type() != TypeOf(V(0)) {
                t.Fatalf("c.Call[0] is type %v, want %v", outs[0].Type(), TypeOf(V(0)))
        }
        f := outs[0].Float()
        if f != 3.14 {
                t.Errorf("constructed func returned %f, want %f", f, 3.14)
        }

        // check that types already in binary are found
        type T1 int
        testCases := []struct {
                in, out  []Type
                variadic bool
                want     interface{}
        }{
                {in: []Type{TypeOf(T1(0))}, want: (func(T1))(nil)},
                {in: []Type{TypeOf(int(0))}, want: (func(int))(nil)},
                {in: []Type{SliceOf(TypeOf(int(0)))}, variadic: true, want: (func(...int))(nil)},
                {in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false)}, want: (func(int) bool)(nil)},
                {in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false), TypeOf("")}, want: (func(int) (bool, string))(nil)},
        }
        for _, tt := range testCases {
                checkSameType(t, FuncOf(tt.in, tt.out, tt.variadic), tt.want)
        }

        // check that variadic requires last element be a slice.
        FuncOf([]Type{TypeOf(1), TypeOf(""), SliceOf(TypeOf(false))}, nil, true)
        shouldPanic(func() { FuncOf([]Type{TypeOf(0), TypeOf(""), TypeOf(false)}, nil, true) })
        shouldPanic(func() { FuncOf(nil, nil, true) })
}

type B1 struct {
        X int
        Y int
        Z int
}

func BenchmarkFieldByName1(b *testing.B) {
        t := TypeOf(B1{})
        b.RunParallel(func(pb *testing.PB) {
                for pb.Next() {
                        t.FieldByName("Z")
                }
        })
}

func BenchmarkFieldByName2(b *testing.B) {
        t := TypeOf(S3{})
        b.RunParallel(func(pb *testing.PB) {
                for pb.Next() {
                        t.FieldByName("B")
                }
        })
}

type R0 struct {
        *R1
        *R2
        *R3
        *R4
}

type R1 struct {
        *R5
        *R6
        *R7
        *R8
}

type R2 R1
type R3 R1
type R4 R1

type R5 struct {
        *R9
        *R10
        *R11
        *R12
}

type R6 R5
type R7 R5
type R8 R5

type R9 struct {
        *R13
        *R14
        *R15
        *R16
}

type R10 R9
type R11 R9
type R12 R9

type R13 struct {
        *R17
        *R18
        *R19
        *R20
}

type R14 R13
type R15 R13
type R16 R13

type R17 struct {
        *R21
        *R22
        *R23
        *R24
}

type R18 R17
type R19 R17
type R20 R17

type R21 struct {
        X int
}

type R22 R21
type R23 R21
type R24 R21

func TestEmbed(t *testing.T) {
        typ := TypeOf(R0{})
        f, ok := typ.FieldByName("X")
        if ok {
                t.Fatalf(`FieldByName("X") should fail, returned %v`, f.Index)
        }
}

func BenchmarkFieldByName3(b *testing.B) {
        t := TypeOf(R0{})
        b.RunParallel(func(pb *testing.PB) {
                for pb.Next() {
                        t.FieldByName("X")
                }
        })
}

type S struct {
        i1 int64
        i2 int64
}

func BenchmarkInterfaceBig(b *testing.B) {
        v := ValueOf(S{})
        b.RunParallel(func(pb *testing.PB) {
                for pb.Next() {
                        v.Interface()
                }
        })
        b.StopTimer()
}

func TestAllocsInterfaceBig(t *testing.T) {
        if testing.Short() {
                t.Skip("skipping malloc count in short mode")
        }
        v := ValueOf(S{})
        if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
                t.Error("allocs:", allocs)
        }
}

func BenchmarkInterfaceSmall(b *testing.B) {
        v := ValueOf(int64(0))
        b.RunParallel(func(pb *testing.PB) {
                for pb.Next() {
                        v.Interface()
                }
        })
}

func TestAllocsInterfaceSmall(t *testing.T) {
        if testing.Short() {
                t.Skip("skipping malloc count in short mode")
        }
        v := ValueOf(int64(0))
        if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
                t.Error("allocs:", allocs)
        }
}

// An exhaustive is a mechanism for writing exhaustive or stochastic tests.
// The basic usage is:
//
//      for x.Next() {
//              ... code using x.Maybe() or x.Choice(n) to create test cases ...
//      }
//
// Each iteration of the loop returns a different set of results, until all
// possible result sets have been explored. It is okay for different code paths
// to make different method call sequences on x, but there must be no
// other source of non-determinism in the call sequences.
//
// When faced with a new decision, x chooses randomly. Future explorations
// of that path will choose successive values for the result. Thus, stopping
// the loop after a fixed number of iterations gives somewhat stochastic
// testing.
//
// Example:
//
//      for x.Next() {
//              v := make([]bool, x.Choose(4))
//              for i := range v {
//                      v[i] = x.Maybe()
//              }
//              fmt.Println(v)
//      }
//
// prints (in some order):
//
//      []
//      [false]
//      [true]
//      [false false]
//      [false true]
//      ...
//      [true true]
//      [false false false]
//      ...
//      [true true true]
//      [false false false false]
//      ...
//      [true true true true]
//
type exhaustive struct {
        r    *rand.Rand
        pos  int
        last []choice
}

type choice struct {
        off int
        n   int
        max int
}

func (x *exhaustive) Next() bool {
        if x.r == nil {
                x.r = rand.New(rand.NewSource(time.Now().UnixNano()))
        }
        x.pos = 0
        if x.last == nil {
                x.last = []choice{}
                return true
        }
        for i := len(x.last) - 1; i >= 0; i-- {
                c := &x.last[i]
                if c.n+1 < c.max {
                        c.n++
                        x.last = x.last[:i+1]
                        return true
                }
        }
        return false
}

func (x *exhaustive) Choose(max int) int {
        if x.pos >= len(x.last) {
                x.last = append(x.last, choice{x.r.Intn(max), 0, max})
        }
        c := &x.last[x.pos]
        x.pos++
        if c.max != max {
                panic("inconsistent use of exhaustive tester")
        }
        return (c.n + c.off) % max
}

func (x *exhaustive) Maybe() bool {
        return x.Choose(2) == 1
}

func GCFunc(args []Value) []Value {
        runtime.GC()
        return []Value{}
}

func TestReflectFuncTraceback(t *testing.T) {
        f := MakeFunc(TypeOf(func() {}), GCFunc)
        f.Call([]Value{})
}

func TestReflectMethodTraceback(t *testing.T) {
        p := Point{3, 4}
        m := ValueOf(p).MethodByName("GCMethod")
        i := ValueOf(m.Interface()).Call([]Value{ValueOf(5)})[0].Int()
        if i != 8 {
                t.Errorf("Call returned %d; want 8", i)
        }
}

func TestBigZero(t *testing.T) {
        const size = 1 << 10
        var v [size]byte
        z := Zero(ValueOf(v).Type()).Interface().([size]byte)
        for i := 0; i < size; i++ {
                if z[i] != 0 {
                        t.Fatalf("Zero object not all zero, index %d", i)
                }
        }
}

func TestFieldByIndexNil(t *testing.T) {
        type P struct {
                F int
        }
        type T struct {
                *P
        }
        v := ValueOf(T{})

        v.FieldByName("P") // should be fine

        defer func() {
                if err := recover(); err == nil {
                        t.Fatalf("no error")
                } else if !strings.Contains(fmt.Sprint(err), "nil pointer to embedded struct") {
                        t.Fatalf(`err=%q, wanted error containing "nil pointer to embedded struct"`, err)
                }
        }()
        v.FieldByName("F") // should panic

        t.Fatalf("did not panic")
}

// Given
//      type Outer struct {
//              *Inner
//              ...
//      }
// the compiler generates the implementation of (*Outer).M dispatching to the embedded Inner.
// The implementation is logically:
//      func (p *Outer) M() {
//              (p.Inner).M()
//      }
// but since the only change here is the replacement of one pointer receiver with another,
// the actual generated code overwrites the original receiver with the p.Inner pointer and
// then jumps to the M method expecting the *Inner receiver.
//
// During reflect.Value.Call, we create an argument frame and the associated data structures
// to describe it to the garbage collector, populate the frame, call reflect.call to
// run a function call using that frame, and then copy the results back out of the frame.
// The reflect.call function does a memmove of the frame structure onto the
// stack (to set up the inputs), runs the call, and the memmoves the stack back to
// the frame structure (to preserve the outputs).
//
// Originally reflect.call did not distinguish inputs from outputs: both memmoves
// were for the full stack frame. However, in the case where the called function was
// one of these wrappers, the rewritten receiver is almost certainly a different type
// than the original receiver. This is not a problem on the stack, where we use the
// program counter to determine the type information and understand that
// during (*Outer).M the receiver is an *Outer while during (*Inner).M the receiver in the same
// memory word is now an *Inner. But in the statically typed argument frame created
// by reflect, the receiver is always an *Outer. Copying the modified receiver pointer
// off the stack into the frame will store an *Inner there, and then if a garbage collection
// happens to scan that argument frame before it is discarded, it will scan the *Inner
// memory as if it were an *Outer. If the two have different memory layouts, the
// collection will interpret the memory incorrectly.
//
// One such possible incorrect interpretation is to treat two arbitrary memory words
// (Inner.P1 and Inner.P2 below) as an interface (Outer.R below). Because interpreting
// an interface requires dereferencing the itab word, the misinterpretation will try to
// deference Inner.P1, causing a crash during garbage collection.
//
// This came up in a real program in issue 7725.

type Outer struct {
        *Inner
        R io.Reader
}

type Inner struct {
        X  *Outer
        P1 uintptr
        P2 uintptr
}

func (pi *Inner) M() {
        // Clear references to pi so that the only way the
        // garbage collection will find the pointer is in the
        // argument frame, typed as a *Outer.
        pi.X.Inner = nil

        // Set up an interface value that will cause a crash.
        // P1 = 1 is a non-zero, so the interface looks non-nil.
        // P2 = pi ensures that the data word points into the
        // allocated heap; if not the collection skips the interface
        // value as irrelevant, without dereferencing P1.
        pi.P1 = 1
        pi.P2 = uintptr(unsafe.Pointer(pi))
}

func TestCallMethodJump(t *testing.T) {
        // In reflect.Value.Call, trigger a garbage collection after reflect.call
        // returns but before the args frame has been discarded.
        // This is a little clumsy but makes the failure repeatable.
        *CallGC = true

        p := &Outer{Inner: new(Inner)}
        p.Inner.X = p
        ValueOf(p).Method(0).Call(nil)

        // Stop garbage collecting during reflect.call.
        *CallGC = false
}

func TestMakeFuncStackCopy(t *testing.T) {
        target := func(in []Value) []Value {
                runtime.GC()
                useStack(16)
                return []Value{ValueOf(9)}
        }

        var concrete func(*int, int) int
        fn := MakeFunc(ValueOf(concrete).Type(), target)
        ValueOf(&concrete).Elem().Set(fn)
        x := concrete(nil, 7)
        if x != 9 {
                t.Errorf("have %#q want 9", x)
        }
}

// use about n KB of stack
func useStack(n int) {
        if n == 0 {
                return
        }
        var b [1024]byte // makes frame about 1KB
        useStack(n - 1 + int(b[99]))
}

type Impl struct{}

func (Impl) F() {}

func TestValueString(t *testing.T) {
        rv := ValueOf(Impl{})
        if rv.String() != "<reflect_test.Impl Value>" {
                t.Errorf("ValueOf(Impl{}).String() = %q, want %q", rv.String(), "<reflect_test.Impl Value>")
        }

        method := rv.Method(0)
        if method.String() != "<func() Value>" {
                t.Errorf("ValueOf(Impl{}).Method(0).String() = %q, want %q", method.String(), "<func() Value>")
        }
}

func TestInvalid(t *testing.T) {
        // Used to have inconsistency between IsValid() and Kind() != Invalid.
        type T struct{ v interface{} }

        v := ValueOf(T{}).Field(0)
        if v.IsValid() != true || v.Kind() != Interface {
                t.Errorf("field: IsValid=%v, Kind=%v, want true, Interface", v.IsValid(), v.Kind())
        }
        v = v.Elem()
        if v.IsValid() != false || v.Kind() != Invalid {
                t.Errorf("field elem: IsValid=%v, Kind=%v, want false, Invalid", v.IsValid(), v.Kind())
        }
}

// Issue 8917.
func TestLargeGCProg(t *testing.T) {
        fv := ValueOf(func([256]*byte) {})
        fv.Call([]Value{ValueOf([256]*byte{})})
}

func fieldIndexRecover(t Type, i int) (recovered interface{}) {
        defer func() {
                recovered = recover()
        }()

        t.Field(i)
        return
}

// Issue 15046.
func TestTypeFieldOutOfRangePanic(t *testing.T) {
        typ := TypeOf(struct{ X int }{10})
        testIndices := [...]struct {
                i         int
                mustPanic bool
        }{
                0: {-2, true},
                1: {0, false},
                2: {1, true},
                3: {1 << 10, true},
        }
        for i, tt := range testIndices {
                recoveredErr := fieldIndexRecover(typ, tt.i)
                if tt.mustPanic {
                        if recoveredErr == nil {
                                t.Errorf("#%d: fieldIndex %d expected to panic", i, tt.i)
                        }
                } else {
                        if recoveredErr != nil {
                                t.Errorf("#%d: got err=%v, expected no panic", i, recoveredErr)
                        }
                }
        }
}

// Issue 9179.
func TestCallGC(t *testing.T) {
        f := func(a, b, c, d, e string) {
        }
        g := func(in []Value) []Value {
                runtime.GC()
                return nil
        }
        typ := ValueOf(f).Type()
        f2 := MakeFunc(typ, g).Interface().(func(string, string, string, string, string))
        f2("four", "five5", "six666", "seven77", "eight888")
}

// Issue 18635 (function version).
func TestKeepFuncLive(t *testing.T) {
        // Test that we keep makeFuncImpl live as long as it is
        // referenced on the stack.
        typ := TypeOf(func(i int) {})
        var f, g func(in []Value) []Value
        f = func(in []Value) []Value {
                clobber()
                i := int(in[0].Int())
                if i > 0 {
                        // We can't use Value.Call here because
                        // runtime.call* will keep the makeFuncImpl
                        // alive. However, by converting it to an
                        // interface value and calling that,
                        // reflect.callReflect is the only thing that
                        // can keep the makeFuncImpl live.
                        //
                        // Alternate between f and g so that if we do
                        // reuse the memory prematurely it's more
                        // likely to get obviously corrupted.
                        MakeFunc(typ, g).Interface().(func(i int))(i - 1)
                }
                return nil
        }
        g = func(in []Value) []Value {
                clobber()
                i := int(in[0].Int())
                MakeFunc(typ, f).Interface().(func(i int))(i)
                return nil
        }
        MakeFunc(typ, f).Call([]Value{ValueOf(10)})
}

type UnExportedFirst int

func (i UnExportedFirst) ΦExported()  {}
func (i UnExportedFirst) unexported() {}

// Issue 21177
func TestMethodByNameUnExportedFirst(t *testing.T) {
        defer func() {
                if recover() != nil {
                        t.Errorf("should not panic")
                }
        }()
        typ := TypeOf(UnExportedFirst(0))
        m, _ := typ.MethodByName("ΦExported")
        if m.Name != "ΦExported" {
                t.Errorf("got %s, expected ΦExported", m.Name)
        }
}

// Issue 18635 (method version).
type KeepMethodLive struct{}

func (k KeepMethodLive) Method1(i int) {
        clobber()
        if i > 0 {
                ValueOf(k).MethodByName("Method2").Interface().(func(i int))(i - 1)
        }
}

func (k KeepMethodLive) Method2(i int) {
        clobber()
        ValueOf(k).MethodByName("Method1").Interface().(func(i int))(i)
}

func TestKeepMethodLive(t *testing.T) {
        // Test that we keep methodValue live as long as it is
        // referenced on the stack.
        KeepMethodLive{}.Method1(10)
}

// clobber tries to clobber unreachable memory.
func clobber() {
        runtime.GC()
        for i := 1; i < 32; i++ {
                for j := 0; j < 10; j++ {
                        obj := make([]*byte, i)
                        sink = obj
                }
        }
        runtime.GC()
}

type funcLayoutTest struct {
        rcvr, t                  Type
        size, argsize, retOffset uintptr
        stack                    []byte // pointer bitmap: 1 is pointer, 0 is scalar (or uninitialized)
        gc                       []byte
}

var funcLayoutTests []funcLayoutTest

func init() {
        var argAlign uintptr = PtrSize
        if runtime.GOARCH == "amd64p32" {
                argAlign = 2 * PtrSize
        }
        roundup := func(x uintptr, a uintptr) uintptr {
                return (x + a - 1) / a * a
        }

        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        nil,
                        ValueOf(func(a, b string) string { return "" }).Type(),
                        6 * PtrSize,
                        4 * PtrSize,
                        4 * PtrSize,
                        []byte{1, 0, 1},
                        []byte{1, 0, 1, 0, 1},
                })

        var r []byte
        if PtrSize == 4 {
                r = []byte{0, 0, 0, 1}
        } else {
                r = []byte{0, 0, 1}
        }
        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        nil,
                        ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(),
                        roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
                        roundup(3*4, PtrSize) + PtrSize + 2,
                        roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
                        r,
                        r,
                })

        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        nil,
                        ValueOf(func(a map[int]int, b uintptr, c interface{}) {}).Type(),
                        4 * PtrSize,
                        4 * PtrSize,
                        4 * PtrSize,
                        []byte{1, 0, 1, 1},
                        []byte{1, 0, 1, 1},
                })

        type S struct {
                a, b uintptr
                c, d *byte
        }
        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        nil,
                        ValueOf(func(a S) {}).Type(),
                        4 * PtrSize,
                        4 * PtrSize,
                        4 * PtrSize,
                        []byte{0, 0, 1, 1},
                        []byte{0, 0, 1, 1},
                })

        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        ValueOf((*byte)(nil)).Type(),
                        ValueOf(func(a uintptr, b *int) {}).Type(),
                        roundup(3*PtrSize, argAlign),
                        3 * PtrSize,
                        roundup(3*PtrSize, argAlign),
                        []byte{1, 0, 1},
                        []byte{1, 0, 1},
                })

        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        nil,
                        ValueOf(func(a uintptr) {}).Type(),
                        roundup(PtrSize, argAlign),
                        PtrSize,
                        roundup(PtrSize, argAlign),
                        []byte{},
                        []byte{},
                })

        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        nil,
                        ValueOf(func() uintptr { return 0 }).Type(),
                        PtrSize,
                        0,
                        0,
                        []byte{},
                        []byte{},
                })

        funcLayoutTests = append(funcLayoutTests,
                funcLayoutTest{
                        ValueOf(uintptr(0)).Type(),
                        ValueOf(func(a uintptr) {}).Type(),
                        2 * PtrSize,
                        2 * PtrSize,
                        2 * PtrSize,
                        []byte{1},
                        []byte{1},
                        // Note: this one is tricky, as the receiver is not a pointer. But we
                        // pass the receiver by reference to the autogenerated pointer-receiver
                        // version of the function.
                })
}

func TestFuncLayout(t *testing.T) {
        t.Skip("gccgo does not use funcLayout")
        for _, lt := range funcLayoutTests {
                typ, argsize, retOffset, stack, gc, ptrs := FuncLayout(lt.t, lt.rcvr)
                if typ.Size() != lt.size {
                        t.Errorf("funcLayout(%v, %v).size=%d, want %d", lt.t, lt.rcvr, typ.Size(), lt.size)
                }
                if argsize != lt.argsize {
                        t.Errorf("funcLayout(%v, %v).argsize=%d, want %d", lt.t, lt.rcvr, argsize, lt.argsize)
                }
                if retOffset != lt.retOffset {
                        t.Errorf("funcLayout(%v, %v).retOffset=%d, want %d", lt.t, lt.rcvr, retOffset, lt.retOffset)
                }
                if !bytes.Equal(stack, lt.stack) {
                        t.Errorf("funcLayout(%v, %v).stack=%v, want %v", lt.t, lt.rcvr, stack, lt.stack)
                }
                if !bytes.Equal(gc, lt.gc) {
                        t.Errorf("funcLayout(%v, %v).gc=%v, want %v", lt.t, lt.rcvr, gc, lt.gc)
                }
                if ptrs && len(stack) == 0 || !ptrs && len(stack) > 0 {
                        t.Errorf("funcLayout(%v, %v) pointers flag=%v, want %v", lt.t, lt.rcvr, ptrs, !ptrs)
                }
        }
}

func verifyGCBits(t *testing.T, typ Type, bits []byte) {
        heapBits := GCBits(New(typ).Interface())
        if !bytes.Equal(heapBits, bits) {
                t.Errorf("heapBits incorrect for %v\nhave %v\nwant %v", typ, heapBits, bits)
        }
}

func verifyGCBitsSlice(t *testing.T, typ Type, cap int, bits []byte) {
        // Creating a slice causes the runtime to repeat a bitmap,
        // which exercises a different path from making the compiler
        // repeat a bitmap for a small array or executing a repeat in
        // a GC program.
        val := MakeSlice(typ, 0, cap)
        data := NewAt(ArrayOf(cap, typ), unsafe.Pointer(val.Pointer()))
        heapBits := GCBits(data.Interface())
        // Repeat the bitmap for the slice size, trimming scalars in
        // the last element.
        bits = rep(cap, bits)
        for len(bits) > 2 && bits[len(bits)-1] == 0 {
                bits = bits[:len(bits)-1]
        }
        if len(bits) == 2 && bits[0] == 0 && bits[1] == 0 {
                bits = bits[:0]
        }
        if !bytes.Equal(heapBits, bits) {
                t.Errorf("heapBits incorrect for make(%v, 0, %v)\nhave %v\nwant %v", typ, cap, heapBits, bits)
        }
}

func TestGCBits(t *testing.T) {
        t.Skip("gccgo does not use gcbits yet")

        verifyGCBits(t, TypeOf((*byte)(nil)), []byte{1})

        // Building blocks for types seen by the compiler (like [2]Xscalar).
        // The compiler will create the type structures for the derived types,
        // including their GC metadata.
        type Xscalar struct{ x uintptr }
        type Xptr struct{ x *byte }
        type Xptrscalar struct {
                *byte
                uintptr
        }
        type Xscalarptr struct {
                uintptr
                *byte
        }
        type Xbigptrscalar struct {
                _ [100]*byte
                _ [100]uintptr
        }

        var Tscalar, Tint64, Tptr, Tscalarptr, Tptrscalar, Tbigptrscalar Type
        {
                // Building blocks for types constructed by reflect.
                // This code is in a separate block so that code below
                // cannot accidentally refer to these.
                // The compiler must NOT see types derived from these
                // (for example, [2]Scalar must NOT appear in the program),
                // or else reflect will use it instead of having to construct one.
                // The goal is to test the construction.
                type Scalar struct{ x uintptr }
                type Ptr struct{ x *byte }
                type Ptrscalar struct {
                        *byte
                        uintptr
                }
                type Scalarptr struct {
                        uintptr
                        *byte
                }
                type Bigptrscalar struct {
                        _ [100]*byte
                        _ [100]uintptr
                }
                type Int64 int64
                Tscalar = TypeOf(Scalar{})
                Tint64 = TypeOf(Int64(0))
                Tptr = TypeOf(Ptr{})
                Tscalarptr = TypeOf(Scalarptr{})
                Tptrscalar = TypeOf(Ptrscalar{})
                Tbigptrscalar = TypeOf(Bigptrscalar{})
        }

        empty := []byte{}

        verifyGCBits(t, TypeOf(Xscalar{}), empty)
        verifyGCBits(t, Tscalar, empty)
        verifyGCBits(t, TypeOf(Xptr{}), lit(1))
        verifyGCBits(t, Tptr, lit(1))
        verifyGCBits(t, TypeOf(Xscalarptr{}), lit(0, 1))
        verifyGCBits(t, Tscalarptr, lit(0, 1))
        verifyGCBits(t, TypeOf(Xptrscalar{}), lit(1))
        verifyGCBits(t, Tptrscalar, lit(1))

        verifyGCBits(t, TypeOf([0]Xptr{}), empty)
        verifyGCBits(t, ArrayOf(0, Tptr), empty)
        verifyGCBits(t, TypeOf([1]Xptrscalar{}), lit(1))
        verifyGCBits(t, ArrayOf(1, Tptrscalar), lit(1))
        verifyGCBits(t, TypeOf([2]Xscalar{}), empty)
        verifyGCBits(t, ArrayOf(2, Tscalar), empty)
        verifyGCBits(t, TypeOf([10000]Xscalar{}), empty)
        verifyGCBits(t, ArrayOf(10000, Tscalar), empty)
        verifyGCBits(t, TypeOf([2]Xptr{}), lit(1, 1))
        verifyGCBits(t, ArrayOf(2, Tptr), lit(1, 1))
        verifyGCBits(t, TypeOf([10000]Xptr{}), rep(10000, lit(1)))
        verifyGCBits(t, ArrayOf(10000, Tptr), rep(10000, lit(1)))
        verifyGCBits(t, TypeOf([2]Xscalarptr{}), lit(0, 1, 0, 1))
        verifyGCBits(t, ArrayOf(2, Tscalarptr), lit(0, 1, 0, 1))
        verifyGCBits(t, TypeOf([10000]Xscalarptr{}), rep(10000, lit(0, 1)))
        verifyGCBits(t, ArrayOf(10000, Tscalarptr), rep(10000, lit(0, 1)))
        verifyGCBits(t, TypeOf([2]Xptrscalar{}), lit(1, 0, 1))
        verifyGCBits(t, ArrayOf(2, Tptrscalar), lit(1, 0, 1))
        verifyGCBits(t, TypeOf([10000]Xptrscalar{}), rep(10000, lit(1, 0)))
        verifyGCBits(t, ArrayOf(10000, Tptrscalar), rep(10000, lit(1, 0)))
        verifyGCBits(t, TypeOf([1][10000]Xptrscalar{}), rep(10000, lit(1, 0)))
        verifyGCBits(t, ArrayOf(1, ArrayOf(10000, Tptrscalar)), rep(10000, lit(1, 0)))
        verifyGCBits(t, TypeOf([2][10000]Xptrscalar{}), rep(2*10000, lit(1, 0)))
        verifyGCBits(t, ArrayOf(2, ArrayOf(10000, Tptrscalar)), rep(2*10000, lit(1, 0)))
        verifyGCBits(t, TypeOf([4]Xbigptrscalar{}), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
        verifyGCBits(t, ArrayOf(4, Tbigptrscalar), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))

        verifyGCBitsSlice(t, TypeOf([]Xptr{}), 0, empty)
        verifyGCBitsSlice(t, SliceOf(Tptr), 0, empty)
        verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 1, lit(1))
        verifyGCBitsSlice(t, SliceOf(Tptrscalar), 1, lit(1))
        verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 2, lit(0))
        verifyGCBitsSlice(t, SliceOf(Tscalar), 2, lit(0))
        verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 10000, lit(0))
        verifyGCBitsSlice(t, SliceOf(Tscalar), 10000, lit(0))
        verifyGCBitsSlice(t, TypeOf([]Xptr{}), 2, lit(1))
        verifyGCBitsSlice(t, SliceOf(Tptr), 2, lit(1))
        verifyGCBitsSlice(t, TypeOf([]Xptr{}), 10000, lit(1))
        verifyGCBitsSlice(t, SliceOf(Tptr), 10000, lit(1))
        verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 2, lit(0, 1))
        verifyGCBitsSlice(t, SliceOf(Tscalarptr), 2, lit(0, 1))
        verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 10000, lit(0, 1))
        verifyGCBitsSlice(t, SliceOf(Tscalarptr), 10000, lit(0, 1))
        verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 2, lit(1, 0))
        verifyGCBitsSlice(t, SliceOf(Tptrscalar), 2, lit(1, 0))
        verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 10000, lit(1, 0))
        verifyGCBitsSlice(t, SliceOf(Tptrscalar), 10000, lit(1, 0))
        verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 1, rep(10000, lit(1, 0)))
        verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 1, rep(10000, lit(1, 0)))
        verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 2, rep(10000, lit(1, 0)))
        verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 2, rep(10000, lit(1, 0)))
        verifyGCBitsSlice(t, TypeOf([]Xbigptrscalar{}), 4, join(rep(100, lit(1)), rep(100, lit(0))))
        verifyGCBitsSlice(t, SliceOf(Tbigptrscalar), 4, join(rep(100, lit(1)), rep(100, lit(0))))

        verifyGCBits(t, TypeOf((chan [100]Xscalar)(nil)), lit(1))
        verifyGCBits(t, ChanOf(BothDir, ArrayOf(100, Tscalar)), lit(1))

        verifyGCBits(t, TypeOf((func([10000]Xscalarptr))(nil)), lit(1))
        verifyGCBits(t, FuncOf([]Type{ArrayOf(10000, Tscalarptr)}, nil, false), lit(1))

        verifyGCBits(t, TypeOf((map[[10000]Xscalarptr]Xscalar)(nil)), lit(1))
        verifyGCBits(t, MapOf(ArrayOf(10000, Tscalarptr), Tscalar), lit(1))

        verifyGCBits(t, TypeOf((*[10000]Xscalar)(nil)), lit(1))
        verifyGCBits(t, PtrTo(ArrayOf(10000, Tscalar)), lit(1))

        verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1))
        verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1))

        hdr := make([]byte, 8/PtrSize)

        verifyMapBucket := func(t *testing.T, k, e Type, m interface{}, want []byte) {
                verifyGCBits(t, MapBucketOf(k, e), want)
                verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
        }
        verifyMapBucket(t,
                Tscalar, Tptr,
                map[Xscalar]Xptr(nil),
                join(hdr, rep(8, lit(0)), rep(8, lit(1)), lit(1)))
        verifyMapBucket(t,
                Tscalarptr, Tptr,
                map[Xscalarptr]Xptr(nil),
                join(hdr, rep(8, lit(0, 1)), rep(8, lit(1)), lit(1)))
        verifyMapBucket(t, Tint64, Tptr,
                map[int64]Xptr(nil),
                join(hdr, rep(8, rep(8/PtrSize, lit(0))), rep(8, lit(1)), naclpad(), lit(1)))
        verifyMapBucket(t,
                Tscalar, Tscalar,
                map[Xscalar]Xscalar(nil),
                empty)
        verifyMapBucket(t,
                ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar),
                map[[2]Xscalarptr][3]Xptrscalar(nil),
                join(hdr, rep(8*2, lit(0, 1)), rep(8*3, lit(1, 0)), lit(1)))
        verifyMapBucket(t,
                ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
                map[[64 / PtrSize]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
                join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
        verifyMapBucket(t,
                ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
                map[[64/PtrSize + 1]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
                join(hdr, rep(8, lit(1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
        verifyMapBucket(t,
                ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
                map[[64 / PtrSize]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
                join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8, lit(1)), lit(1)))
        verifyMapBucket(t,
                ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
                map[[64/PtrSize + 1]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
                join(hdr, rep(8, lit(1)), rep(8, lit(1)), lit(1)))
}

func naclpad() []byte {
        if runtime.GOARCH == "amd64p32" {
                return lit(0)
        }
        return nil
}

func rep(n int, b []byte) []byte { return bytes.Repeat(b, n) }
func join(b ...[]byte) []byte    { return bytes.Join(b, nil) }
func lit(x ...byte) []byte       { return x }

func TestTypeOfTypeOf(t *testing.T) {
        // Check that all the type constructors return concrete *rtype implementations.
        // It's difficult to test directly because the reflect package is only at arm's length.
        // The easiest thing to do is just call a function that crashes if it doesn't get an *rtype.
        check := func(name string, typ Type) {
                if underlying := TypeOf(typ).String(); underlying != "*reflect.rtype" {
                        t.Errorf("%v returned %v, not *reflect.rtype", name, underlying)
                }
        }

        type T struct{ int }
        check("TypeOf", TypeOf(T{}))

        check("ArrayOf", ArrayOf(10, TypeOf(T{})))
        check("ChanOf", ChanOf(BothDir, TypeOf(T{})))
        check("FuncOf", FuncOf([]Type{TypeOf(T{})}, nil, false))
        check("MapOf", MapOf(TypeOf(T{}), TypeOf(T{})))
        check("PtrTo", PtrTo(TypeOf(T{})))
        check("SliceOf", SliceOf(TypeOf(T{})))
}

type XM struct{ _ bool }

func (*XM) String() string { return "" }

func TestPtrToMethods(t *testing.T) {
        var y struct{ XM }
        yp := New(TypeOf(y)).Interface()
        _, ok := yp.(fmt.Stringer)
        if !ok {
                t.Fatal("does not implement Stringer, but should")
        }
}

func TestMapAlloc(t *testing.T) {
        m := ValueOf(make(map[int]int, 10))
        k := ValueOf(5)
        v := ValueOf(7)
        allocs := testing.AllocsPerRun(100, func() {
                m.SetMapIndex(k, v)
        })
        if allocs > 0.5 {
                t.Errorf("allocs per map assignment: want 0 got %f", allocs)
        }

        const size = 1000
        tmp := 0
        val := ValueOf(&tmp).Elem()
        allocs = testing.AllocsPerRun(100, func() {
                mv := MakeMapWithSize(TypeOf(map[int]int{}), size)
                // Only adding half of the capacity to not trigger re-allocations due too many overloaded buckets.
                for i := 0; i < size/2; i++ {
                        val.SetInt(int64(i))
                        mv.SetMapIndex(val, val)
                }
        })
        if allocs > 10 {
                t.Errorf("allocs per map assignment: want at most 10 got %f", allocs)
        }
        // Empirical testing shows that with capacity hint single run will trigger 3 allocations and without 91. I set
        // the threshold to 10, to not make it overly brittle if something changes in the initial allocation of the
        // map, but to still catch a regression where we keep re-allocating in the hashmap as new entries are added.
}

func TestChanAlloc(t *testing.T) {
        // Note: for a chan int, the return Value must be allocated, so we
        // use a chan *int instead.
        c := ValueOf(make(chan *int, 1))
        v := ValueOf(new(int))
        allocs := testing.AllocsPerRun(100, func() {
                c.Send(v)
                _, _ = c.Recv()
        })
        if allocs < 0.5 || allocs > 1.5 {
                t.Errorf("allocs per chan send/recv: want 1 got %f", allocs)
        }
        // Note: there is one allocation in reflect.recv which seems to be
        // a limitation of escape analysis. If that is ever fixed the
        // allocs < 0.5 condition will trigger and this test should be fixed.
}

type TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678 int

type nameTest struct {
        v    interface{}
        want string
}

var nameTests = []nameTest{
        {(*int32)(nil), "int32"},
        {(*D1)(nil), "D1"},
        {(*[]D1)(nil), ""},
        {(*chan D1)(nil), ""},
        {(*func() D1)(nil), ""},
        {(*<-chan D1)(nil), ""},
        {(*chan<- D1)(nil), ""},
        {(*interface{})(nil), ""},
        {(*interface {
                F()
        })(nil), ""},
        {(*TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678)(nil), "TheNameOfThisTypeIsExactly255BytesLongSoWhenTheCompilerPrependsTheReflectTestPackageNameAndExtraStarTheLinkerRuntimeAndReflectPackagesWillHaveToCorrectlyDecodeTheSecondLengthByte0123456789_0123456789_0123456789_0123456789_0123456789_012345678"},
}

func TestNames(t *testing.T) {
        for _, test := range nameTests {
                typ := TypeOf(test.v).Elem()
                if got := typ.Name(); got != test.want {
                        t.Errorf("%v Name()=%q, want %q", typ, got, test.want)
                }
        }
}

/*
gccgo doesn't really record whether a type is exported.
It's not in the reflect API anyhow.

func TestExported(t *testing.T) {
        type ΦExported struct{}
        type φUnexported struct{}
        type BigP *big
        type P int
        type p *P
        type P2 p
        type p3 p

        type exportTest struct {
                v    interface{}
                want bool
        }
        exportTests := []exportTest{
                {D1{}, true},
                {(*D1)(nil), true},
                {big{}, false},
                {(*big)(nil), false},
                {(BigP)(nil), true},
                {(*BigP)(nil), true},
                {ΦExported{}, true},
                {φUnexported{}, false},
                {P(0), true},
                {(p)(nil), false},
                {(P2)(nil), true},
                {(p3)(nil), false},
        }

        for i, test := range exportTests {
                typ := TypeOf(test.v)
                if got := IsExported(typ); got != test.want {
                        t.Errorf("%d: %s exported=%v, want %v", i, typ.Name(), got, test.want)
                }
        }
}
*/

type embed struct {
        EmbedWithUnexpMeth
}

/*
func TestNameBytesAreAligned(t *testing.T) {
        typ := TypeOf(embed{})
        b := FirstMethodNameBytes(typ)
        v := uintptr(unsafe.Pointer(b))
        if v%unsafe.Alignof((*byte)(nil)) != 0 {
                t.Errorf("reflect.name.bytes pointer is not aligned: %x", v)
        }
}
*/

func TestTypeStrings(t *testing.T) {
        type stringTest struct {
                typ  Type
                want string
        }
        stringTests := []stringTest{
                {TypeOf(func(int) {}), "func(int)"},
                {FuncOf([]Type{TypeOf(int(0))}, nil, false), "func(int)"},
                {TypeOf(XM{}), "reflect_test.XM"},
                {TypeOf(new(XM)), "*reflect_test.XM"},
                {TypeOf(new(XM).String), "func() string"},
                {TypeOf(new(XM)).Method(0).Type, "func(*reflect_test.XM) string"},
                {ChanOf(3, TypeOf(XM{})), "chan reflect_test.XM"},
                {MapOf(TypeOf(int(0)), TypeOf(XM{})), "map[int]reflect_test.XM"},
                {ArrayOf(3, TypeOf(XM{})), "[3]reflect_test.XM"},
                {ArrayOf(3, TypeOf(struct{}{})), "[3]struct {}"},
        }

        for i, test := range stringTests {
                if got, want := test.typ.String(), test.want; got != want {
                        t.Errorf("type %d String()=%q, want %q", i, got, want)
                }
        }
}

/*
gccgo does not have resolveReflectName.

func TestOffsetLock(t *testing.T) {
        var wg sync.WaitGroup
        for i := 0; i < 4; i++ {
                i := i
                wg.Add(1)
                go func() {
                        for j := 0; j < 50; j++ {
                                ResolveReflectName(fmt.Sprintf("OffsetLockName:%d:%d", i, j))
                        }
                        wg.Done()
                }()
        }
        wg.Wait()
}
*/

func BenchmarkNew(b *testing.B) {
        v := TypeOf(XM{})
        b.RunParallel(func(pb *testing.PB) {
                for pb.Next() {
                        New(v)
                }
        })
}

func TestSwapper(t *testing.T) {
        type I int
        var a, b, c I
        type pair struct {
                x, y int
        }
        type pairPtr struct {
                x, y int
                p    *I
        }
        type S string

        tests := []struct {
                in   interface{}
                i, j int
                want interface{}
        }{
                {
                        in:   []int{1, 20, 300},
                        i:    0,
                        j:    2,
                        want: []int{300, 20, 1},
                },
                {
                        in:   []uintptr{1, 20, 300},
                        i:    0,
                        j:    2,
                        want: []uintptr{300, 20, 1},
                },
                {
                        in:   []int16{1, 20, 300},
                        i:    0,
                        j:    2,
                        want: []int16{300, 20, 1},
                },
                {
                        in:   []int8{1, 20, 100},
                        i:    0,
                        j:    2,
                        want: []int8{100, 20, 1},
                },
                {
                        in:   []*I{&a, &b, &c},
                        i:    0,
                        j:    2,
                        want: []*I{&c, &b, &a},
                },
                {
                        in:   []string{"eric", "sergey", "larry"},
                        i:    0,
                        j:    2,
                        want: []string{"larry", "sergey", "eric"},
                },
                {
                        in:   []S{"eric", "sergey", "larry"},
                        i:    0,
                        j:    2,
                        want: []S{"larry", "sergey", "eric"},
                },
                {
                        in:   []pair{{1, 2}, {3, 4}, {5, 6}},
                        i:    0,
                        j:    2,
                        want: []pair{{5, 6}, {3, 4}, {1, 2}},
                },
                {
                        in:   []pairPtr{{1, 2, &a}, {3, 4, &b}, {5, 6, &c}},
                        i:    0,
                        j:    2,
                        want: []pairPtr{{5, 6, &c}, {3, 4, &b}, {1, 2, &a}},
                },
        }

        for i, tt := range tests {
                inStr := fmt.Sprint(tt.in)
                Swapper(tt.in)(tt.i, tt.j)
                if !DeepEqual(tt.in, tt.want) {
                        t.Errorf("%d. swapping %v and %v of %v = %v; want %v", i, tt.i, tt.j, inStr, tt.in, tt.want)
                }
        }
}

// TestUnaddressableField tests that the reflect package will not allow
// a type from another package to be used as a named type with an
// unexported field.
//
// This ensures that unexported fields cannot be modified by other packages.
func TestUnaddressableField(t *testing.T) {
        var b Buffer // type defined in reflect, a different package
        var localBuffer struct {
                buf []byte
        }
        lv := ValueOf(&localBuffer).Elem()
        rv := ValueOf(b)
        shouldPanic(func() {
                lv.Set(rv)
        })
}

type Tint int

type Tint2 = Tint

type Talias1 struct {
        byte
        uint8
        int
        int32
        rune
}

type Talias2 struct {
        Tint
        Tint2
}

func TestAliasNames(t *testing.T) {
        t1 := Talias1{byte: 1, uint8: 2, int: 3, int32: 4, rune: 5}
        out := fmt.Sprintf("%#v", t1)
        want := "reflect_test.Talias1{byte:0x1, uint8:0x2, int:3, int32:4, rune:5}"
        if out != want {
                t.Errorf("Talias1 print:\nhave: %s\nwant: %s", out, want)
        }

        t2 := Talias2{Tint: 1, Tint2: 2}
        out = fmt.Sprintf("%#v", t2)
        want = "reflect_test.Talias2{Tint:1, Tint2:2}"
        if out != want {
                t.Errorf("Talias2 print:\nhave: %s\nwant: %s", out, want)
        }
}

func TestIssue22031(t *testing.T) {
        type s []struct{ C int }

        type t1 struct{ s }
        type t2 struct{ f s }

        tests := []Value{
                ValueOf(t1{s{{}}}).Field(0).Index(0).Field(0),
                ValueOf(t2{s{{}}}).Field(0).Index(0).Field(0),
        }

        for i, test := range tests {
                if test.CanSet() {
                        t.Errorf("%d: CanSet: got true, want false", i)
                }
        }
}

type NonExportedFirst int

func (i NonExportedFirst) ΦExported()       {}
func (i NonExportedFirst) nonexported() int { panic("wrong") }

func TestIssue22073(t *testing.T) {
        m := ValueOf(NonExportedFirst(0)).Method(0)

        if got := m.Type().NumOut(); got != 0 {
                t.Errorf("NumOut: got %v, want 0", got)
        }

        // Shouldn't panic.
        m.Call(nil)
}