github.com/zxy12/golang151_with_comment@v0.0.0-20190507085033-721809559d3c/reflect/all_test.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package reflect_test
     6  
     7  import (
     8  	"bytes"
     9  	"encoding/base64"
    10  	"flag"
    11  	"fmt"
    12  	"io"
    13  	"math/rand"
    14  	"os"
    15  	. "reflect"
    16  	"runtime"
    17  	"sort"
    18  	"strconv"
    19  	"strings"
    20  	"sync"
    21  	"testing"
    22  	"time"
    23  	"unsafe"
    24  )
    25  
    26  func TestBool(t *testing.T) {
    27  	v := ValueOf(true)
    28  	if v.Bool() != true {
    29  		t.Fatal("ValueOf(true).Bool() = false")
    30  	}
    31  }
    32  
    33  type integer int
    34  type T struct {
    35  	a int
    36  	b float64
    37  	c string
    38  	d *int
    39  }
    40  
    41  type pair struct {
    42  	i interface{}
    43  	s string
    44  }
    45  
    46  func isDigit(c uint8) bool { return '0' <= c && c <= '9' }
    47  
    48  func assert(t *testing.T, s, want string) {
    49  	if s != want {
    50  		t.Errorf("have %#q want %#q", s, want)
    51  	}
    52  }
    53  
    54  func typestring(i interface{}) string { return TypeOf(i).String() }
    55  
    56  var typeTests = []pair{
    57  	{struct{ x int }{}, "int"},
    58  	{struct{ x int8 }{}, "int8"},
    59  	{struct{ x int16 }{}, "int16"},
    60  	{struct{ x int32 }{}, "int32"},
    61  	{struct{ x int64 }{}, "int64"},
    62  	{struct{ x uint }{}, "uint"},
    63  	{struct{ x uint8 }{}, "uint8"},
    64  	{struct{ x uint16 }{}, "uint16"},
    65  	{struct{ x uint32 }{}, "uint32"},
    66  	{struct{ x uint64 }{}, "uint64"},
    67  	{struct{ x float32 }{}, "float32"},
    68  	{struct{ x float64 }{}, "float64"},
    69  	{struct{ x int8 }{}, "int8"},
    70  	{struct{ x (**int8) }{}, "**int8"},
    71  	{struct{ x (**integer) }{}, "**reflect_test.integer"},
    72  	{struct{ x ([32]int32) }{}, "[32]int32"},
    73  	{struct{ x ([]int8) }{}, "[]int8"},
    74  	{struct{ x (map[string]int32) }{}, "map[string]int32"},
    75  	{struct{ x (chan<- string) }{}, "chan<- string"},
    76  	{struct {
    77  		x struct {
    78  			c chan *int32
    79  			d float32
    80  		}
    81  	}{},
    82  		"struct { c chan *int32; d float32 }",
    83  	},
    84  	{struct{ x (func(a int8, b int32)) }{}, "func(int8, int32)"},
    85  	{struct {
    86  		x struct {
    87  			c func(chan *integer, *int8)
    88  		}
    89  	}{},
    90  		"struct { c func(chan *reflect_test.integer, *int8) }",
    91  	},
    92  	{struct {
    93  		x struct {
    94  			a int8
    95  			b int32
    96  		}
    97  	}{},
    98  		"struct { a int8; b int32 }",
    99  	},
   100  	{struct {
   101  		x struct {
   102  			a int8
   103  			b int8
   104  			c int32
   105  		}
   106  	}{},
   107  		"struct { a int8; b int8; c int32 }",
   108  	},
   109  	{struct {
   110  		x struct {
   111  			a int8
   112  			b int8
   113  			c int8
   114  			d int32
   115  		}
   116  	}{},
   117  		"struct { a int8; b int8; c int8; d int32 }",
   118  	},
   119  	{struct {
   120  		x struct {
   121  			a int8
   122  			b int8
   123  			c int8
   124  			d int8
   125  			e int32
   126  		}
   127  	}{},
   128  		"struct { a int8; b int8; c int8; d int8; e int32 }",
   129  	},
   130  	{struct {
   131  		x struct {
   132  			a int8
   133  			b int8
   134  			c int8
   135  			d int8
   136  			e int8
   137  			f int32
   138  		}
   139  	}{},
   140  		"struct { a int8; b int8; c int8; d int8; e int8; f int32 }",
   141  	},
   142  	{struct {
   143  		x struct {
   144  			a int8 `reflect:"hi there"`
   145  		}
   146  	}{},
   147  		`struct { a int8 "reflect:\"hi there\"" }`,
   148  	},
   149  	{struct {
   150  		x struct {
   151  			a int8 `reflect:"hi \x00there\t\n\"\\"`
   152  		}
   153  	}{},
   154  		`struct { a int8 "reflect:\"hi \\x00there\\t\\n\\\"\\\\\"" }`,
   155  	},
   156  	{struct {
   157  		x struct {
   158  			f func(args ...int)
   159  		}
   160  	}{},
   161  		"struct { f func(...int) }",
   162  	},
   163  	{struct {
   164  		x (interface {
   165  			a(func(func(int) int) func(func(int)) int)
   166  			b()
   167  		})
   168  	}{},
   169  		"interface { reflect_test.a(func(func(int) int) func(func(int)) int); reflect_test.b() }",
   170  	},
   171  }
   172  
   173  var valueTests = []pair{
   174  	{new(int), "132"},
   175  	{new(int8), "8"},
   176  	{new(int16), "16"},
   177  	{new(int32), "32"},
   178  	{new(int64), "64"},
   179  	{new(uint), "132"},
   180  	{new(uint8), "8"},
   181  	{new(uint16), "16"},
   182  	{new(uint32), "32"},
   183  	{new(uint64), "64"},
   184  	{new(float32), "256.25"},
   185  	{new(float64), "512.125"},
   186  	{new(complex64), "532.125+10i"},
   187  	{new(complex128), "564.25+1i"},
   188  	{new(string), "stringy cheese"},
   189  	{new(bool), "true"},
   190  	{new(*int8), "*int8(0)"},
   191  	{new(**int8), "**int8(0)"},
   192  	{new([5]int32), "[5]int32{0, 0, 0, 0, 0}"},
   193  	{new(**integer), "**reflect_test.integer(0)"},
   194  	{new(map[string]int32), "map[string]int32{<can't iterate on maps>}"},
   195  	{new(chan<- string), "chan<- string"},
   196  	{new(func(a int8, b int32)), "func(int8, int32)(0)"},
   197  	{new(struct {
   198  		c chan *int32
   199  		d float32
   200  	}),
   201  		"struct { c chan *int32; d float32 }{chan *int32, 0}",
   202  	},
   203  	{new(struct{ c func(chan *integer, *int8) }),
   204  		"struct { c func(chan *reflect_test.integer, *int8) }{func(chan *reflect_test.integer, *int8)(0)}",
   205  	},
   206  	{new(struct {
   207  		a int8
   208  		b int32
   209  	}),
   210  		"struct { a int8; b int32 }{0, 0}",
   211  	},
   212  	{new(struct {
   213  		a int8
   214  		b int8
   215  		c int32
   216  	}),
   217  		"struct { a int8; b int8; c int32 }{0, 0, 0}",
   218  	},
   219  }
   220  
   221  func testType(t *testing.T, i int, typ Type, want string) {
   222  	s := typ.String()
   223  	if s != want {
   224  		t.Errorf("#%d: have %#q, want %#q", i, s, want)
   225  	}
   226  }
   227  
   228  func TestTypes(t *testing.T) {
   229  	for i, tt := range typeTests {
   230  		testType(t, i, ValueOf(tt.i).Field(0).Type(), tt.s)
   231  	}
   232  }
   233  
   234  func TestSet(t *testing.T) {
   235  	for i, tt := range valueTests {
   236  		v := ValueOf(tt.i)
   237  		v = v.Elem()
   238  		switch v.Kind() {
   239  		case Int:
   240  			v.SetInt(132)
   241  		case Int8:
   242  			v.SetInt(8)
   243  		case Int16:
   244  			v.SetInt(16)
   245  		case Int32:
   246  			v.SetInt(32)
   247  		case Int64:
   248  			v.SetInt(64)
   249  		case Uint:
   250  			v.SetUint(132)
   251  		case Uint8:
   252  			v.SetUint(8)
   253  		case Uint16:
   254  			v.SetUint(16)
   255  		case Uint32:
   256  			v.SetUint(32)
   257  		case Uint64:
   258  			v.SetUint(64)
   259  		case Float32:
   260  			v.SetFloat(256.25)
   261  		case Float64:
   262  			v.SetFloat(512.125)
   263  		case Complex64:
   264  			v.SetComplex(532.125 + 10i)
   265  		case Complex128:
   266  			v.SetComplex(564.25 + 1i)
   267  		case String:
   268  			v.SetString("stringy cheese")
   269  		case Bool:
   270  			v.SetBool(true)
   271  		}
   272  		s := valueToString(v)
   273  		if s != tt.s {
   274  			t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
   275  		}
   276  	}
   277  }
   278  
   279  func TestSetValue(t *testing.T) {
   280  	for i, tt := range valueTests {
   281  		v := ValueOf(tt.i).Elem()
   282  		switch v.Kind() {
   283  		case Int:
   284  			v.Set(ValueOf(int(132)))
   285  		case Int8:
   286  			v.Set(ValueOf(int8(8)))
   287  		case Int16:
   288  			v.Set(ValueOf(int16(16)))
   289  		case Int32:
   290  			v.Set(ValueOf(int32(32)))
   291  		case Int64:
   292  			v.Set(ValueOf(int64(64)))
   293  		case Uint:
   294  			v.Set(ValueOf(uint(132)))
   295  		case Uint8:
   296  			v.Set(ValueOf(uint8(8)))
   297  		case Uint16:
   298  			v.Set(ValueOf(uint16(16)))
   299  		case Uint32:
   300  			v.Set(ValueOf(uint32(32)))
   301  		case Uint64:
   302  			v.Set(ValueOf(uint64(64)))
   303  		case Float32:
   304  			v.Set(ValueOf(float32(256.25)))
   305  		case Float64:
   306  			v.Set(ValueOf(512.125))
   307  		case Complex64:
   308  			v.Set(ValueOf(complex64(532.125 + 10i)))
   309  		case Complex128:
   310  			v.Set(ValueOf(complex128(564.25 + 1i)))
   311  		case String:
   312  			v.Set(ValueOf("stringy cheese"))
   313  		case Bool:
   314  			v.Set(ValueOf(true))
   315  		}
   316  		s := valueToString(v)
   317  		if s != tt.s {
   318  			t.Errorf("#%d: have %#q, want %#q", i, s, tt.s)
   319  		}
   320  	}
   321  }
   322  
   323  var _i = 7
   324  
   325  var valueToStringTests = []pair{
   326  	{123, "123"},
   327  	{123.5, "123.5"},
   328  	{byte(123), "123"},
   329  	{"abc", "abc"},
   330  	{T{123, 456.75, "hello", &_i}, "reflect_test.T{123, 456.75, hello, *int(&7)}"},
   331  	{new(chan *T), "*chan *reflect_test.T(&chan *reflect_test.T)"},
   332  	{[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
   333  	{&[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})"},
   334  	{[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"},
   335  	{&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[]int(&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"},
   336  }
   337  
   338  func TestValueToString(t *testing.T) {
   339  	for i, test := range valueToStringTests {
   340  		s := valueToString(ValueOf(test.i))
   341  		if s != test.s {
   342  			t.Errorf("#%d: have %#q, want %#q", i, s, test.s)
   343  		}
   344  	}
   345  }
   346  
   347  func TestArrayElemSet(t *testing.T) {
   348  	v := ValueOf(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).Elem()
   349  	v.Index(4).SetInt(123)
   350  	s := valueToString(v)
   351  	const want = "[10]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
   352  	if s != want {
   353  		t.Errorf("[10]int: have %#q want %#q", s, want)
   354  	}
   355  
   356  	v = ValueOf([]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})
   357  	v.Index(4).SetInt(123)
   358  	s = valueToString(v)
   359  	const want1 = "[]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}"
   360  	if s != want1 {
   361  		t.Errorf("[]int: have %#q want %#q", s, want1)
   362  	}
   363  }
   364  
   365  func TestPtrPointTo(t *testing.T) {
   366  	var ip *int32
   367  	var i int32 = 1234
   368  	vip := ValueOf(&ip)
   369  	vi := ValueOf(&i).Elem()
   370  	vip.Elem().Set(vi.Addr())
   371  	if *ip != 1234 {
   372  		t.Errorf("got %d, want 1234", *ip)
   373  	}
   374  
   375  	ip = nil
   376  	vp := ValueOf(&ip).Elem()
   377  	vp.Set(Zero(vp.Type()))
   378  	if ip != nil {
   379  		t.Errorf("got non-nil (%p), want nil", ip)
   380  	}
   381  }
   382  
   383  func TestPtrSetNil(t *testing.T) {
   384  	var i int32 = 1234
   385  	ip := &i
   386  	vip := ValueOf(&ip)
   387  	vip.Elem().Set(Zero(vip.Elem().Type()))
   388  	if ip != nil {
   389  		t.Errorf("got non-nil (%d), want nil", *ip)
   390  	}
   391  }
   392  
   393  func TestMapSetNil(t *testing.T) {
   394  	m := make(map[string]int)
   395  	vm := ValueOf(&m)
   396  	vm.Elem().Set(Zero(vm.Elem().Type()))
   397  	if m != nil {
   398  		t.Errorf("got non-nil (%p), want nil", m)
   399  	}
   400  }
   401  
   402  func TestAll(t *testing.T) {
   403  	testType(t, 1, TypeOf((int8)(0)), "int8")
   404  	testType(t, 2, TypeOf((*int8)(nil)).Elem(), "int8")
   405  
   406  	typ := TypeOf((*struct {
   407  		c chan *int32
   408  		d float32
   409  	})(nil))
   410  	testType(t, 3, typ, "*struct { c chan *int32; d float32 }")
   411  	etyp := typ.Elem()
   412  	testType(t, 4, etyp, "struct { c chan *int32; d float32 }")
   413  	styp := etyp
   414  	f := styp.Field(0)
   415  	testType(t, 5, f.Type, "chan *int32")
   416  
   417  	f, present := styp.FieldByName("d")
   418  	if !present {
   419  		t.Errorf("FieldByName says present field is absent")
   420  	}
   421  	testType(t, 6, f.Type, "float32")
   422  
   423  	f, present = styp.FieldByName("absent")
   424  	if present {
   425  		t.Errorf("FieldByName says absent field is present")
   426  	}
   427  
   428  	typ = TypeOf([32]int32{})
   429  	testType(t, 7, typ, "[32]int32")
   430  	testType(t, 8, typ.Elem(), "int32")
   431  
   432  	typ = TypeOf((map[string]*int32)(nil))
   433  	testType(t, 9, typ, "map[string]*int32")
   434  	mtyp := typ
   435  	testType(t, 10, mtyp.Key(), "string")
   436  	testType(t, 11, mtyp.Elem(), "*int32")
   437  
   438  	typ = TypeOf((chan<- string)(nil))
   439  	testType(t, 12, typ, "chan<- string")
   440  	testType(t, 13, typ.Elem(), "string")
   441  
   442  	// make sure tag strings are not part of element type
   443  	typ = TypeOf(struct {
   444  		d []uint32 `reflect:"TAG"`
   445  	}{}).Field(0).Type
   446  	testType(t, 14, typ, "[]uint32")
   447  }
   448  
   449  func TestInterfaceGet(t *testing.T) {
   450  	var inter struct {
   451  		E interface{}
   452  	}
   453  	inter.E = 123.456
   454  	v1 := ValueOf(&inter)
   455  	v2 := v1.Elem().Field(0)
   456  	assert(t, v2.Type().String(), "interface {}")
   457  	i2 := v2.Interface()
   458  	v3 := ValueOf(i2)
   459  	assert(t, v3.Type().String(), "float64")
   460  }
   461  
   462  func TestInterfaceValue(t *testing.T) {
   463  	var inter struct {
   464  		E interface{}
   465  	}
   466  	inter.E = 123.456
   467  	v1 := ValueOf(&inter)
   468  	v2 := v1.Elem().Field(0)
   469  	assert(t, v2.Type().String(), "interface {}")
   470  	v3 := v2.Elem()
   471  	assert(t, v3.Type().String(), "float64")
   472  
   473  	i3 := v2.Interface()
   474  	if _, ok := i3.(float64); !ok {
   475  		t.Error("v2.Interface() did not return float64, got ", TypeOf(i3))
   476  	}
   477  }
   478  
   479  func TestFunctionValue(t *testing.T) {
   480  	var x interface{} = func() {}
   481  	v := ValueOf(x)
   482  	if fmt.Sprint(v.Interface()) != fmt.Sprint(x) {
   483  		t.Fatalf("TestFunction returned wrong pointer")
   484  	}
   485  	assert(t, v.Type().String(), "func()")
   486  }
   487  
   488  var appendTests = []struct {
   489  	orig, extra []int
   490  }{
   491  	{make([]int, 2, 4), []int{22}},
   492  	{make([]int, 2, 4), []int{22, 33, 44}},
   493  }
   494  
   495  func sameInts(x, y []int) bool {
   496  	if len(x) != len(y) {
   497  		return false
   498  	}
   499  	for i, xx := range x {
   500  		if xx != y[i] {
   501  			return false
   502  		}
   503  	}
   504  	return true
   505  }
   506  
   507  func TestAppend(t *testing.T) {
   508  	for i, test := range appendTests {
   509  		origLen, extraLen := len(test.orig), len(test.extra)
   510  		want := append(test.orig, test.extra...)
   511  		// Convert extra from []int to []Value.
   512  		e0 := make([]Value, len(test.extra))
   513  		for j, e := range test.extra {
   514  			e0[j] = ValueOf(e)
   515  		}
   516  		// Convert extra from []int to *SliceValue.
   517  		e1 := ValueOf(test.extra)
   518  		// Test Append.
   519  		a0 := ValueOf(test.orig)
   520  		have0 := Append(a0, e0...).Interface().([]int)
   521  		if !sameInts(have0, want) {
   522  			t.Errorf("Append #%d: have %v, want %v (%p %p)", i, have0, want, test.orig, have0)
   523  		}
   524  		// Check that the orig and extra slices were not modified.
   525  		if len(test.orig) != origLen {
   526  			t.Errorf("Append #%d origLen: have %v, want %v", i, len(test.orig), origLen)
   527  		}
   528  		if len(test.extra) != extraLen {
   529  			t.Errorf("Append #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
   530  		}
   531  		// Test AppendSlice.
   532  		a1 := ValueOf(test.orig)
   533  		have1 := AppendSlice(a1, e1).Interface().([]int)
   534  		if !sameInts(have1, want) {
   535  			t.Errorf("AppendSlice #%d: have %v, want %v", i, have1, want)
   536  		}
   537  		// Check that the orig and extra slices were not modified.
   538  		if len(test.orig) != origLen {
   539  			t.Errorf("AppendSlice #%d origLen: have %v, want %v", i, len(test.orig), origLen)
   540  		}
   541  		if len(test.extra) != extraLen {
   542  			t.Errorf("AppendSlice #%d extraLen: have %v, want %v", i, len(test.extra), extraLen)
   543  		}
   544  	}
   545  }
   546  
   547  func TestCopy(t *testing.T) {
   548  	a := []int{1, 2, 3, 4, 10, 9, 8, 7}
   549  	b := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
   550  	c := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
   551  	for i := 0; i < len(b); i++ {
   552  		if b[i] != c[i] {
   553  			t.Fatalf("b != c before test")
   554  		}
   555  	}
   556  	a1 := a
   557  	b1 := b
   558  	aa := ValueOf(&a1).Elem()
   559  	ab := ValueOf(&b1).Elem()
   560  	for tocopy := 1; tocopy <= 7; tocopy++ {
   561  		aa.SetLen(tocopy)
   562  		Copy(ab, aa)
   563  		aa.SetLen(8)
   564  		for i := 0; i < tocopy; i++ {
   565  			if a[i] != b[i] {
   566  				t.Errorf("(i) tocopy=%d a[%d]=%d, b[%d]=%d",
   567  					tocopy, i, a[i], i, b[i])
   568  			}
   569  		}
   570  		for i := tocopy; i < len(b); i++ {
   571  			if b[i] != c[i] {
   572  				if i < len(a) {
   573  					t.Errorf("(ii) tocopy=%d a[%d]=%d, b[%d]=%d, c[%d]=%d",
   574  						tocopy, i, a[i], i, b[i], i, c[i])
   575  				} else {
   576  					t.Errorf("(iii) tocopy=%d b[%d]=%d, c[%d]=%d",
   577  						tocopy, i, b[i], i, c[i])
   578  				}
   579  			} else {
   580  				t.Logf("tocopy=%d elem %d is okay\n", tocopy, i)
   581  			}
   582  		}
   583  	}
   584  }
   585  
   586  func TestCopyArray(t *testing.T) {
   587  	a := [8]int{1, 2, 3, 4, 10, 9, 8, 7}
   588  	b := [11]int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44}
   589  	c := b
   590  	aa := ValueOf(&a).Elem()
   591  	ab := ValueOf(&b).Elem()
   592  	Copy(ab, aa)
   593  	for i := 0; i < len(a); i++ {
   594  		if a[i] != b[i] {
   595  			t.Errorf("(i) a[%d]=%d, b[%d]=%d", i, a[i], i, b[i])
   596  		}
   597  	}
   598  	for i := len(a); i < len(b); i++ {
   599  		if b[i] != c[i] {
   600  			t.Errorf("(ii) b[%d]=%d, c[%d]=%d", i, b[i], i, c[i])
   601  		} else {
   602  			t.Logf("elem %d is okay\n", i)
   603  		}
   604  	}
   605  }
   606  
   607  func TestBigUnnamedStruct(t *testing.T) {
   608  	b := struct{ a, b, c, d int64 }{1, 2, 3, 4}
   609  	v := ValueOf(b)
   610  	b1 := v.Interface().(struct {
   611  		a, b, c, d int64
   612  	})
   613  	if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d {
   614  		t.Errorf("ValueOf(%v).Interface().(*Big) = %v", b, b1)
   615  	}
   616  }
   617  
   618  type big struct {
   619  	a, b, c, d, e int64
   620  }
   621  
   622  func TestBigStruct(t *testing.T) {
   623  	b := big{1, 2, 3, 4, 5}
   624  	v := ValueOf(b)
   625  	b1 := v.Interface().(big)
   626  	if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d || b1.e != b.e {
   627  		t.Errorf("ValueOf(%v).Interface().(big) = %v", b, b1)
   628  	}
   629  }
   630  
   631  type Basic struct {
   632  	x int
   633  	y float32
   634  }
   635  
   636  type NotBasic Basic
   637  
   638  type DeepEqualTest struct {
   639  	a, b interface{}
   640  	eq   bool
   641  }
   642  
   643  // Simple functions for DeepEqual tests.
   644  var (
   645  	fn1 func()             // nil.
   646  	fn2 func()             // nil.
   647  	fn3 = func() { fn1() } // Not nil.
   648  )
   649  
   650  var deepEqualTests = []DeepEqualTest{
   651  	// Equalities
   652  	{nil, nil, true},
   653  	{1, 1, true},
   654  	{int32(1), int32(1), true},
   655  	{0.5, 0.5, true},
   656  	{float32(0.5), float32(0.5), true},
   657  	{"hello", "hello", true},
   658  	{make([]int, 10), make([]int, 10), true},
   659  	{&[3]int{1, 2, 3}, &[3]int{1, 2, 3}, true},
   660  	{Basic{1, 0.5}, Basic{1, 0.5}, true},
   661  	{error(nil), error(nil), true},
   662  	{map[int]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, true},
   663  	{fn1, fn2, true},
   664  
   665  	// Inequalities
   666  	{1, 2, false},
   667  	{int32(1), int32(2), false},
   668  	{0.5, 0.6, false},
   669  	{float32(0.5), float32(0.6), false},
   670  	{"hello", "hey", false},
   671  	{make([]int, 10), make([]int, 11), false},
   672  	{&[3]int{1, 2, 3}, &[3]int{1, 2, 4}, false},
   673  	{Basic{1, 0.5}, Basic{1, 0.6}, false},
   674  	{Basic{1, 0}, Basic{2, 0}, false},
   675  	{map[int]string{1: "one", 3: "two"}, map[int]string{2: "two", 1: "one"}, false},
   676  	{map[int]string{1: "one", 2: "txo"}, map[int]string{2: "two", 1: "one"}, false},
   677  	{map[int]string{1: "one"}, map[int]string{2: "two", 1: "one"}, false},
   678  	{map[int]string{2: "two", 1: "one"}, map[int]string{1: "one"}, false},
   679  	{nil, 1, false},
   680  	{1, nil, false},
   681  	{fn1, fn3, false},
   682  	{fn3, fn3, false},
   683  	{[][]int{{1}}, [][]int{{2}}, false},
   684  
   685  	// Nil vs empty: not the same.
   686  	{[]int{}, []int(nil), false},
   687  	{[]int{}, []int{}, true},
   688  	{[]int(nil), []int(nil), true},
   689  	{map[int]int{}, map[int]int(nil), false},
   690  	{map[int]int{}, map[int]int{}, true},
   691  	{map[int]int(nil), map[int]int(nil), true},
   692  
   693  	// Mismatched types
   694  	{1, 1.0, false},
   695  	{int32(1), int64(1), false},
   696  	{0.5, "hello", false},
   697  	{[]int{1, 2, 3}, [3]int{1, 2, 3}, false},
   698  	{&[3]interface{}{1, 2, 4}, &[3]interface{}{1, 2, "s"}, false},
   699  	{Basic{1, 0.5}, NotBasic{1, 0.5}, false},
   700  	{map[uint]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, false},
   701  }
   702  
   703  func TestDeepEqual(t *testing.T) {
   704  	for _, test := range deepEqualTests {
   705  		if r := DeepEqual(test.a, test.b); r != test.eq {
   706  			t.Errorf("DeepEqual(%v, %v) = %v, want %v", test.a, test.b, r, test.eq)
   707  		}
   708  	}
   709  }
   710  
   711  func TestTypeOf(t *testing.T) {
   712  	// Special case for nil
   713  	if typ := TypeOf(nil); typ != nil {
   714  		t.Errorf("expected nil type for nil value; got %v", typ)
   715  	}
   716  	for _, test := range deepEqualTests {
   717  		v := ValueOf(test.a)
   718  		if !v.IsValid() {
   719  			continue
   720  		}
   721  		typ := TypeOf(test.a)
   722  		if typ != v.Type() {
   723  			t.Errorf("TypeOf(%v) = %v, but ValueOf(%v).Type() = %v", test.a, typ, test.a, v.Type())
   724  		}
   725  	}
   726  }
   727  
   728  type Recursive struct {
   729  	x int
   730  	r *Recursive
   731  }
   732  
   733  func TestDeepEqualRecursiveStruct(t *testing.T) {
   734  	a, b := new(Recursive), new(Recursive)
   735  	*a = Recursive{12, a}
   736  	*b = Recursive{12, b}
   737  	if !DeepEqual(a, b) {
   738  		t.Error("DeepEqual(recursive same) = false, want true")
   739  	}
   740  }
   741  
   742  type _Complex struct {
   743  	a int
   744  	b [3]*_Complex
   745  	c *string
   746  	d map[float64]float64
   747  }
   748  
   749  func TestDeepEqualComplexStruct(t *testing.T) {
   750  	m := make(map[float64]float64)
   751  	stra, strb := "hello", "hello"
   752  	a, b := new(_Complex), new(_Complex)
   753  	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
   754  	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
   755  	if !DeepEqual(a, b) {
   756  		t.Error("DeepEqual(complex same) = false, want true")
   757  	}
   758  }
   759  
   760  func TestDeepEqualComplexStructInequality(t *testing.T) {
   761  	m := make(map[float64]float64)
   762  	stra, strb := "hello", "helloo" // Difference is here
   763  	a, b := new(_Complex), new(_Complex)
   764  	*a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m}
   765  	*b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m}
   766  	if DeepEqual(a, b) {
   767  		t.Error("DeepEqual(complex different) = true, want false")
   768  	}
   769  }
   770  
   771  type UnexpT struct {
   772  	m map[int]int
   773  }
   774  
   775  func TestDeepEqualUnexportedMap(t *testing.T) {
   776  	// Check that DeepEqual can look at unexported fields.
   777  	x1 := UnexpT{map[int]int{1: 2}}
   778  	x2 := UnexpT{map[int]int{1: 2}}
   779  	if !DeepEqual(&x1, &x2) {
   780  		t.Error("DeepEqual(x1, x2) = false, want true")
   781  	}
   782  
   783  	y1 := UnexpT{map[int]int{2: 3}}
   784  	if DeepEqual(&x1, &y1) {
   785  		t.Error("DeepEqual(x1, y1) = true, want false")
   786  	}
   787  }
   788  
   789  func check2ndField(x interface{}, offs uintptr, t *testing.T) {
   790  	s := ValueOf(x)
   791  	f := s.Type().Field(1)
   792  	if f.Offset != offs {
   793  		t.Error("mismatched offsets in structure alignment:", f.Offset, offs)
   794  	}
   795  }
   796  
   797  // Check that structure alignment & offsets viewed through reflect agree with those
   798  // from the compiler itself.
   799  func TestAlignment(t *testing.T) {
   800  	type T1inner struct {
   801  		a int
   802  	}
   803  	type T1 struct {
   804  		T1inner
   805  		f int
   806  	}
   807  	type T2inner struct {
   808  		a, b int
   809  	}
   810  	type T2 struct {
   811  		T2inner
   812  		f int
   813  	}
   814  
   815  	x := T1{T1inner{2}, 17}
   816  	check2ndField(x, uintptr(unsafe.Pointer(&x.f))-uintptr(unsafe.Pointer(&x)), t)
   817  
   818  	x1 := T2{T2inner{2, 3}, 17}
   819  	check2ndField(x1, uintptr(unsafe.Pointer(&x1.f))-uintptr(unsafe.Pointer(&x1)), t)
   820  }
   821  
   822  func Nil(a interface{}, t *testing.T) {
   823  	n := ValueOf(a).Field(0)
   824  	if !n.IsNil() {
   825  		t.Errorf("%v should be nil", a)
   826  	}
   827  }
   828  
   829  func NotNil(a interface{}, t *testing.T) {
   830  	n := ValueOf(a).Field(0)
   831  	if n.IsNil() {
   832  		t.Errorf("value of type %v should not be nil", ValueOf(a).Type().String())
   833  	}
   834  }
   835  
   836  func TestIsNil(t *testing.T) {
   837  	// These implement IsNil.
   838  	// Wrap in extra struct to hide interface type.
   839  	doNil := []interface{}{
   840  		struct{ x *int }{},
   841  		struct{ x interface{} }{},
   842  		struct{ x map[string]int }{},
   843  		struct{ x func() bool }{},
   844  		struct{ x chan int }{},
   845  		struct{ x []string }{},
   846  	}
   847  	for _, ts := range doNil {
   848  		ty := TypeOf(ts).Field(0).Type
   849  		v := Zero(ty)
   850  		v.IsNil() // panics if not okay to call
   851  	}
   852  
   853  	// Check the implementations
   854  	var pi struct {
   855  		x *int
   856  	}
   857  	Nil(pi, t)
   858  	pi.x = new(int)
   859  	NotNil(pi, t)
   860  
   861  	var si struct {
   862  		x []int
   863  	}
   864  	Nil(si, t)
   865  	si.x = make([]int, 10)
   866  	NotNil(si, t)
   867  
   868  	var ci struct {
   869  		x chan int
   870  	}
   871  	Nil(ci, t)
   872  	ci.x = make(chan int)
   873  	NotNil(ci, t)
   874  
   875  	var mi struct {
   876  		x map[int]int
   877  	}
   878  	Nil(mi, t)
   879  	mi.x = make(map[int]int)
   880  	NotNil(mi, t)
   881  
   882  	var ii struct {
   883  		x interface{}
   884  	}
   885  	Nil(ii, t)
   886  	ii.x = 2
   887  	NotNil(ii, t)
   888  
   889  	var fi struct {
   890  		x func(t *testing.T)
   891  	}
   892  	Nil(fi, t)
   893  	fi.x = TestIsNil
   894  	NotNil(fi, t)
   895  }
   896  
   897  func TestInterfaceExtraction(t *testing.T) {
   898  	var s struct {
   899  		W io.Writer
   900  	}
   901  
   902  	s.W = os.Stdout
   903  	v := Indirect(ValueOf(&s)).Field(0).Interface()
   904  	if v != s.W.(interface{}) {
   905  		t.Error("Interface() on interface: ", v, s.W)
   906  	}
   907  }
   908  
   909  func TestNilPtrValueSub(t *testing.T) {
   910  	var pi *int
   911  	if pv := ValueOf(pi); pv.Elem().IsValid() {
   912  		t.Error("ValueOf((*int)(nil)).Elem().IsValid()")
   913  	}
   914  }
   915  
   916  func TestMap(t *testing.T) {
   917  	m := map[string]int{"a": 1, "b": 2}
   918  	mv := ValueOf(m)
   919  	if n := mv.Len(); n != len(m) {
   920  		t.Errorf("Len = %d, want %d", n, len(m))
   921  	}
   922  	keys := mv.MapKeys()
   923  	newmap := MakeMap(mv.Type())
   924  	for k, v := range m {
   925  		// Check that returned Keys match keys in range.
   926  		// These aren't required to be in the same order.
   927  		seen := false
   928  		for _, kv := range keys {
   929  			if kv.String() == k {
   930  				seen = true
   931  				break
   932  			}
   933  		}
   934  		if !seen {
   935  			t.Errorf("Missing key %q", k)
   936  		}
   937  
   938  		// Check that value lookup is correct.
   939  		vv := mv.MapIndex(ValueOf(k))
   940  		if vi := vv.Int(); vi != int64(v) {
   941  			t.Errorf("Key %q: have value %d, want %d", k, vi, v)
   942  		}
   943  
   944  		// Copy into new map.
   945  		newmap.SetMapIndex(ValueOf(k), ValueOf(v))
   946  	}
   947  	vv := mv.MapIndex(ValueOf("not-present"))
   948  	if vv.IsValid() {
   949  		t.Errorf("Invalid key: got non-nil value %s", valueToString(vv))
   950  	}
   951  
   952  	newm := newmap.Interface().(map[string]int)
   953  	if len(newm) != len(m) {
   954  		t.Errorf("length after copy: newm=%d, m=%d", len(newm), len(m))
   955  	}
   956  
   957  	for k, v := range newm {
   958  		mv, ok := m[k]
   959  		if mv != v {
   960  			t.Errorf("newm[%q] = %d, but m[%q] = %d, %v", k, v, k, mv, ok)
   961  		}
   962  	}
   963  
   964  	newmap.SetMapIndex(ValueOf("a"), Value{})
   965  	v, ok := newm["a"]
   966  	if ok {
   967  		t.Errorf("newm[\"a\"] = %d after delete", v)
   968  	}
   969  
   970  	mv = ValueOf(&m).Elem()
   971  	mv.Set(Zero(mv.Type()))
   972  	if m != nil {
   973  		t.Errorf("mv.Set(nil) failed")
   974  	}
   975  }
   976  
   977  func TestNilMap(t *testing.T) {
   978  	var m map[string]int
   979  	mv := ValueOf(m)
   980  	keys := mv.MapKeys()
   981  	if len(keys) != 0 {
   982  		t.Errorf(">0 keys for nil map: %v", keys)
   983  	}
   984  
   985  	// Check that value for missing key is zero.
   986  	x := mv.MapIndex(ValueOf("hello"))
   987  	if x.Kind() != Invalid {
   988  		t.Errorf("m.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
   989  	}
   990  
   991  	// Check big value too.
   992  	var mbig map[string][10 << 20]byte
   993  	x = ValueOf(mbig).MapIndex(ValueOf("hello"))
   994  	if x.Kind() != Invalid {
   995  		t.Errorf("mbig.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x)
   996  	}
   997  
   998  	// Test that deletes from a nil map succeed.
   999  	mv.SetMapIndex(ValueOf("hi"), Value{})
  1000  }
  1001  
  1002  func TestChan(t *testing.T) {
  1003  	for loop := 0; loop < 2; loop++ {
  1004  		var c chan int
  1005  		var cv Value
  1006  
  1007  		// check both ways to allocate channels
  1008  		switch loop {
  1009  		case 1:
  1010  			c = make(chan int, 1)
  1011  			cv = ValueOf(c)
  1012  		case 0:
  1013  			cv = MakeChan(TypeOf(c), 1)
  1014  			c = cv.Interface().(chan int)
  1015  		}
  1016  
  1017  		// Send
  1018  		cv.Send(ValueOf(2))
  1019  		if i := <-c; i != 2 {
  1020  			t.Errorf("reflect Send 2, native recv %d", i)
  1021  		}
  1022  
  1023  		// Recv
  1024  		c <- 3
  1025  		if i, ok := cv.Recv(); i.Int() != 3 || !ok {
  1026  			t.Errorf("native send 3, reflect Recv %d, %t", i.Int(), ok)
  1027  		}
  1028  
  1029  		// TryRecv fail
  1030  		val, ok := cv.TryRecv()
  1031  		if val.IsValid() || ok {
  1032  			t.Errorf("TryRecv on empty chan: %s, %t", valueToString(val), ok)
  1033  		}
  1034  
  1035  		// TryRecv success
  1036  		c <- 4
  1037  		val, ok = cv.TryRecv()
  1038  		if !val.IsValid() {
  1039  			t.Errorf("TryRecv on ready chan got nil")
  1040  		} else if i := val.Int(); i != 4 || !ok {
  1041  			t.Errorf("native send 4, TryRecv %d, %t", i, ok)
  1042  		}
  1043  
  1044  		// TrySend fail
  1045  		c <- 100
  1046  		ok = cv.TrySend(ValueOf(5))
  1047  		i := <-c
  1048  		if ok {
  1049  			t.Errorf("TrySend on full chan succeeded: value %d", i)
  1050  		}
  1051  
  1052  		// TrySend success
  1053  		ok = cv.TrySend(ValueOf(6))
  1054  		if !ok {
  1055  			t.Errorf("TrySend on empty chan failed")
  1056  			select {
  1057  			case x := <-c:
  1058  				t.Errorf("TrySend failed but it did send %d", x)
  1059  			default:
  1060  			}
  1061  		} else {
  1062  			if i = <-c; i != 6 {
  1063  				t.Errorf("TrySend 6, recv %d", i)
  1064  			}
  1065  		}
  1066  
  1067  		// Close
  1068  		c <- 123
  1069  		cv.Close()
  1070  		if i, ok := cv.Recv(); i.Int() != 123 || !ok {
  1071  			t.Errorf("send 123 then close; Recv %d, %t", i.Int(), ok)
  1072  		}
  1073  		if i, ok := cv.Recv(); i.Int() != 0 || ok {
  1074  			t.Errorf("after close Recv %d, %t", i.Int(), ok)
  1075  		}
  1076  	}
  1077  
  1078  	// check creation of unbuffered channel
  1079  	var c chan int
  1080  	cv := MakeChan(TypeOf(c), 0)
  1081  	c = cv.Interface().(chan int)
  1082  	if cv.TrySend(ValueOf(7)) {
  1083  		t.Errorf("TrySend on sync chan succeeded")
  1084  	}
  1085  	if v, ok := cv.TryRecv(); v.IsValid() || ok {
  1086  		t.Errorf("TryRecv on sync chan succeeded: isvalid=%v ok=%v", v.IsValid(), ok)
  1087  	}
  1088  
  1089  	// len/cap
  1090  	cv = MakeChan(TypeOf(c), 10)
  1091  	c = cv.Interface().(chan int)
  1092  	for i := 0; i < 3; i++ {
  1093  		c <- i
  1094  	}
  1095  	if l, m := cv.Len(), cv.Cap(); l != len(c) || m != cap(c) {
  1096  		t.Errorf("Len/Cap = %d/%d want %d/%d", l, m, len(c), cap(c))
  1097  	}
  1098  }
  1099  
  1100  // caseInfo describes a single case in a select test.
  1101  type caseInfo struct {
  1102  	desc      string
  1103  	canSelect bool
  1104  	recv      Value
  1105  	closed    bool
  1106  	helper    func()
  1107  	panic     bool
  1108  }
  1109  
  1110  var allselect = flag.Bool("allselect", false, "exhaustive select test")
  1111  
  1112  func TestSelect(t *testing.T) {
  1113  	selectWatch.once.Do(func() { go selectWatcher() })
  1114  
  1115  	var x exhaustive
  1116  	nch := 0
  1117  	newop := func(n int, cap int) (ch, val Value) {
  1118  		nch++
  1119  		if nch%101%2 == 1 {
  1120  			c := make(chan int, cap)
  1121  			ch = ValueOf(c)
  1122  			val = ValueOf(n)
  1123  		} else {
  1124  			c := make(chan string, cap)
  1125  			ch = ValueOf(c)
  1126  			val = ValueOf(fmt.Sprint(n))
  1127  		}
  1128  		return
  1129  	}
  1130  
  1131  	for n := 0; x.Next(); n++ {
  1132  		if testing.Short() && n >= 1000 {
  1133  			break
  1134  		}
  1135  		if n >= 100000 && !*allselect {
  1136  			break
  1137  		}
  1138  		if n%100000 == 0 && testing.Verbose() {
  1139  			println("TestSelect", n)
  1140  		}
  1141  		var cases []SelectCase
  1142  		var info []caseInfo
  1143  
  1144  		// Ready send.
  1145  		if x.Maybe() {
  1146  			ch, val := newop(len(cases), 1)
  1147  			cases = append(cases, SelectCase{
  1148  				Dir:  SelectSend,
  1149  				Chan: ch,
  1150  				Send: val,
  1151  			})
  1152  			info = append(info, caseInfo{desc: "ready send", canSelect: true})
  1153  		}
  1154  
  1155  		// Ready recv.
  1156  		if x.Maybe() {
  1157  			ch, val := newop(len(cases), 1)
  1158  			ch.Send(val)
  1159  			cases = append(cases, SelectCase{
  1160  				Dir:  SelectRecv,
  1161  				Chan: ch,
  1162  			})
  1163  			info = append(info, caseInfo{desc: "ready recv", canSelect: true, recv: val})
  1164  		}
  1165  
  1166  		// Blocking send.
  1167  		if x.Maybe() {
  1168  			ch, val := newop(len(cases), 0)
  1169  			cases = append(cases, SelectCase{
  1170  				Dir:  SelectSend,
  1171  				Chan: ch,
  1172  				Send: val,
  1173  			})
  1174  			// Let it execute?
  1175  			if x.Maybe() {
  1176  				f := func() { ch.Recv() }
  1177  				info = append(info, caseInfo{desc: "blocking send", helper: f})
  1178  			} else {
  1179  				info = append(info, caseInfo{desc: "blocking send"})
  1180  			}
  1181  		}
  1182  
  1183  		// Blocking recv.
  1184  		if x.Maybe() {
  1185  			ch, val := newop(len(cases), 0)
  1186  			cases = append(cases, SelectCase{
  1187  				Dir:  SelectRecv,
  1188  				Chan: ch,
  1189  			})
  1190  			// Let it execute?
  1191  			if x.Maybe() {
  1192  				f := func() { ch.Send(val) }
  1193  				info = append(info, caseInfo{desc: "blocking recv", recv: val, helper: f})
  1194  			} else {
  1195  				info = append(info, caseInfo{desc: "blocking recv"})
  1196  			}
  1197  		}
  1198  
  1199  		// Zero Chan send.
  1200  		if x.Maybe() {
  1201  			// Maybe include value to send.
  1202  			var val Value
  1203  			if x.Maybe() {
  1204  				val = ValueOf(100)
  1205  			}
  1206  			cases = append(cases, SelectCase{
  1207  				Dir:  SelectSend,
  1208  				Send: val,
  1209  			})
  1210  			info = append(info, caseInfo{desc: "zero Chan send"})
  1211  		}
  1212  
  1213  		// Zero Chan receive.
  1214  		if x.Maybe() {
  1215  			cases = append(cases, SelectCase{
  1216  				Dir: SelectRecv,
  1217  			})
  1218  			info = append(info, caseInfo{desc: "zero Chan recv"})
  1219  		}
  1220  
  1221  		// nil Chan send.
  1222  		if x.Maybe() {
  1223  			cases = append(cases, SelectCase{
  1224  				Dir:  SelectSend,
  1225  				Chan: ValueOf((chan int)(nil)),
  1226  				Send: ValueOf(101),
  1227  			})
  1228  			info = append(info, caseInfo{desc: "nil Chan send"})
  1229  		}
  1230  
  1231  		// nil Chan recv.
  1232  		if x.Maybe() {
  1233  			cases = append(cases, SelectCase{
  1234  				Dir:  SelectRecv,
  1235  				Chan: ValueOf((chan int)(nil)),
  1236  			})
  1237  			info = append(info, caseInfo{desc: "nil Chan recv"})
  1238  		}
  1239  
  1240  		// closed Chan send.
  1241  		if x.Maybe() {
  1242  			ch := make(chan int)
  1243  			close(ch)
  1244  			cases = append(cases, SelectCase{
  1245  				Dir:  SelectSend,
  1246  				Chan: ValueOf(ch),
  1247  				Send: ValueOf(101),
  1248  			})
  1249  			info = append(info, caseInfo{desc: "closed Chan send", canSelect: true, panic: true})
  1250  		}
  1251  
  1252  		// closed Chan recv.
  1253  		if x.Maybe() {
  1254  			ch, val := newop(len(cases), 0)
  1255  			ch.Close()
  1256  			val = Zero(val.Type())
  1257  			cases = append(cases, SelectCase{
  1258  				Dir:  SelectRecv,
  1259  				Chan: ch,
  1260  			})
  1261  			info = append(info, caseInfo{desc: "closed Chan recv", canSelect: true, closed: true, recv: val})
  1262  		}
  1263  
  1264  		var helper func() // goroutine to help the select complete
  1265  
  1266  		// Add default? Must be last case here, but will permute.
  1267  		// Add the default if the select would otherwise
  1268  		// block forever, and maybe add it anyway.
  1269  		numCanSelect := 0
  1270  		canProceed := false
  1271  		canBlock := true
  1272  		canPanic := false
  1273  		helpers := []int{}
  1274  		for i, c := range info {
  1275  			if c.canSelect {
  1276  				canProceed = true
  1277  				canBlock = false
  1278  				numCanSelect++
  1279  				if c.panic {
  1280  					canPanic = true
  1281  				}
  1282  			} else if c.helper != nil {
  1283  				canProceed = true
  1284  				helpers = append(helpers, i)
  1285  			}
  1286  		}
  1287  		if !canProceed || x.Maybe() {
  1288  			cases = append(cases, SelectCase{
  1289  				Dir: SelectDefault,
  1290  			})
  1291  			info = append(info, caseInfo{desc: "default", canSelect: canBlock})
  1292  			numCanSelect++
  1293  		} else if canBlock {
  1294  			// Select needs to communicate with another goroutine.
  1295  			cas := &info[helpers[x.Choose(len(helpers))]]
  1296  			helper = cas.helper
  1297  			cas.canSelect = true
  1298  			numCanSelect++
  1299  		}
  1300  
  1301  		// Permute cases and case info.
  1302  		// Doing too much here makes the exhaustive loop
  1303  		// too exhausting, so just do two swaps.
  1304  		for loop := 0; loop < 2; loop++ {
  1305  			i := x.Choose(len(cases))
  1306  			j := x.Choose(len(cases))
  1307  			cases[i], cases[j] = cases[j], cases[i]
  1308  			info[i], info[j] = info[j], info[i]
  1309  		}
  1310  
  1311  		if helper != nil {
  1312  			// We wait before kicking off a goroutine to satisfy a blocked select.
  1313  			// The pause needs to be big enough to let the select block before
  1314  			// we run the helper, but if we lose that race once in a while it's okay: the
  1315  			// select will just proceed immediately. Not a big deal.
  1316  			// For short tests we can grow [sic] the timeout a bit without fear of taking too long
  1317  			pause := 10 * time.Microsecond
  1318  			if testing.Short() {
  1319  				pause = 100 * time.Microsecond
  1320  			}
  1321  			time.AfterFunc(pause, helper)
  1322  		}
  1323  
  1324  		// Run select.
  1325  		i, recv, recvOK, panicErr := runSelect(cases, info)
  1326  		if panicErr != nil && !canPanic {
  1327  			t.Fatalf("%s\npanicked unexpectedly: %v", fmtSelect(info), panicErr)
  1328  		}
  1329  		if panicErr == nil && canPanic && numCanSelect == 1 {
  1330  			t.Fatalf("%s\nselected #%d incorrectly (should panic)", fmtSelect(info), i)
  1331  		}
  1332  		if panicErr != nil {
  1333  			continue
  1334  		}
  1335  
  1336  		cas := info[i]
  1337  		if !cas.canSelect {
  1338  			recvStr := ""
  1339  			if recv.IsValid() {
  1340  				recvStr = fmt.Sprintf(", received %v, %v", recv.Interface(), recvOK)
  1341  			}
  1342  			t.Fatalf("%s\nselected #%d incorrectly%s", fmtSelect(info), i, recvStr)
  1343  			continue
  1344  		}
  1345  		if cas.panic {
  1346  			t.Fatalf("%s\nselected #%d incorrectly (case should panic)", fmtSelect(info), i)
  1347  			continue
  1348  		}
  1349  
  1350  		if cases[i].Dir == SelectRecv {
  1351  			if !recv.IsValid() {
  1352  				t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, cas.recv.Interface(), !cas.closed)
  1353  			}
  1354  			if !cas.recv.IsValid() {
  1355  				t.Fatalf("%s\nselected #%d but internal error: missing recv value", fmtSelect(info), i)
  1356  			}
  1357  			if recv.Interface() != cas.recv.Interface() || recvOK != !cas.closed {
  1358  				if recv.Interface() == cas.recv.Interface() && recvOK == !cas.closed {
  1359  					t.Fatalf("%s\nselected #%d, got %#v, %v, and DeepEqual is broken on %T", fmtSelect(info), i, recv.Interface(), recvOK, recv.Interface())
  1360  				}
  1361  				t.Fatalf("%s\nselected #%d but got %#v, %v, want %#v, %v", fmtSelect(info), i, recv.Interface(), recvOK, cas.recv.Interface(), !cas.closed)
  1362  			}
  1363  		} else {
  1364  			if recv.IsValid() || recvOK {
  1365  				t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, Value{}, false)
  1366  			}
  1367  		}
  1368  	}
  1369  }
  1370  
  1371  // selectWatch and the selectWatcher are a watchdog mechanism for running Select.
  1372  // If the selectWatcher notices that the select has been blocked for >1 second, it prints
  1373  // an error describing the select and panics the entire test binary.
  1374  var selectWatch struct {
  1375  	sync.Mutex
  1376  	once sync.Once
  1377  	now  time.Time
  1378  	info []caseInfo
  1379  }
  1380  
  1381  func selectWatcher() {
  1382  	for {
  1383  		time.Sleep(1 * time.Second)
  1384  		selectWatch.Lock()
  1385  		if selectWatch.info != nil && time.Since(selectWatch.now) > 10*time.Second {
  1386  			fmt.Fprintf(os.Stderr, "TestSelect:\n%s blocked indefinitely\n", fmtSelect(selectWatch.info))
  1387  			panic("select stuck")
  1388  		}
  1389  		selectWatch.Unlock()
  1390  	}
  1391  }
  1392  
  1393  // runSelect runs a single select test.
  1394  // It returns the values returned by Select but also returns
  1395  // a panic value if the Select panics.
  1396  func runSelect(cases []SelectCase, info []caseInfo) (chosen int, recv Value, recvOK bool, panicErr interface{}) {
  1397  	defer func() {
  1398  		panicErr = recover()
  1399  
  1400  		selectWatch.Lock()
  1401  		selectWatch.info = nil
  1402  		selectWatch.Unlock()
  1403  	}()
  1404  
  1405  	selectWatch.Lock()
  1406  	selectWatch.now = time.Now()
  1407  	selectWatch.info = info
  1408  	selectWatch.Unlock()
  1409  
  1410  	chosen, recv, recvOK = Select(cases)
  1411  	return
  1412  }
  1413  
  1414  // fmtSelect formats the information about a single select test.
  1415  func fmtSelect(info []caseInfo) string {
  1416  	var buf bytes.Buffer
  1417  	fmt.Fprintf(&buf, "\nselect {\n")
  1418  	for i, cas := range info {
  1419  		fmt.Fprintf(&buf, "%d: %s", i, cas.desc)
  1420  		if cas.recv.IsValid() {
  1421  			fmt.Fprintf(&buf, " val=%#v", cas.recv.Interface())
  1422  		}
  1423  		if cas.canSelect {
  1424  			fmt.Fprintf(&buf, " canselect")
  1425  		}
  1426  		if cas.panic {
  1427  			fmt.Fprintf(&buf, " panic")
  1428  		}
  1429  		fmt.Fprintf(&buf, "\n")
  1430  	}
  1431  	fmt.Fprintf(&buf, "}")
  1432  	return buf.String()
  1433  }
  1434  
  1435  type two [2]uintptr
  1436  
  1437  // Difficult test for function call because of
  1438  // implicit padding between arguments.
  1439  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) {
  1440  	return b, c, d, e, f, g, h
  1441  }
  1442  
  1443  func TestFunc(t *testing.T) {
  1444  	ret := ValueOf(dummy).Call([]Value{
  1445  		ValueOf(byte(10)),
  1446  		ValueOf(20),
  1447  		ValueOf(byte(30)),
  1448  		ValueOf(two{40, 50}),
  1449  		ValueOf(byte(60)),
  1450  		ValueOf(float32(70)),
  1451  		ValueOf(byte(80)),
  1452  	})
  1453  	if len(ret) != 7 {
  1454  		t.Fatalf("Call returned %d values, want 7", len(ret))
  1455  	}
  1456  
  1457  	i := byte(ret[0].Uint())
  1458  	j := int(ret[1].Int())
  1459  	k := byte(ret[2].Uint())
  1460  	l := ret[3].Interface().(two)
  1461  	m := byte(ret[4].Uint())
  1462  	n := float32(ret[5].Float())
  1463  	o := byte(ret[6].Uint())
  1464  
  1465  	if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
  1466  		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)
  1467  	}
  1468  }
  1469  
  1470  type emptyStruct struct{}
  1471  
  1472  type nonEmptyStruct struct {
  1473  	member int
  1474  }
  1475  
  1476  func returnEmpty() emptyStruct {
  1477  	return emptyStruct{}
  1478  }
  1479  
  1480  func takesEmpty(e emptyStruct) {
  1481  }
  1482  
  1483  func returnNonEmpty(i int) nonEmptyStruct {
  1484  	return nonEmptyStruct{member: i}
  1485  }
  1486  
  1487  func takesNonEmpty(n nonEmptyStruct) int {
  1488  	return n.member
  1489  }
  1490  
  1491  func TestCallWithStruct(t *testing.T) {
  1492  	r := ValueOf(returnEmpty).Call(nil)
  1493  	if len(r) != 1 || r[0].Type() != TypeOf(emptyStruct{}) {
  1494  		t.Errorf("returning empty struct returned %#v instead", r)
  1495  	}
  1496  	r = ValueOf(takesEmpty).Call([]Value{ValueOf(emptyStruct{})})
  1497  	if len(r) != 0 {
  1498  		t.Errorf("takesEmpty returned values: %#v", r)
  1499  	}
  1500  	r = ValueOf(returnNonEmpty).Call([]Value{ValueOf(42)})
  1501  	if len(r) != 1 || r[0].Type() != TypeOf(nonEmptyStruct{}) || r[0].Field(0).Int() != 42 {
  1502  		t.Errorf("returnNonEmpty returned %#v", r)
  1503  	}
  1504  	r = ValueOf(takesNonEmpty).Call([]Value{ValueOf(nonEmptyStruct{member: 42})})
  1505  	if len(r) != 1 || r[0].Type() != TypeOf(1) || r[0].Int() != 42 {
  1506  		t.Errorf("takesNonEmpty returned %#v", r)
  1507  	}
  1508  }
  1509  
  1510  func BenchmarkCall(b *testing.B) {
  1511  	fv := ValueOf(func(a, b string) {})
  1512  	b.ReportAllocs()
  1513  	b.RunParallel(func(pb *testing.PB) {
  1514  		args := []Value{ValueOf("a"), ValueOf("b")}
  1515  		for pb.Next() {
  1516  			fv.Call(args)
  1517  		}
  1518  	})
  1519  }
  1520  
  1521  func TestMakeFunc(t *testing.T) {
  1522  	f := dummy
  1523  	fv := MakeFunc(TypeOf(f), func(in []Value) []Value { return in })
  1524  	ValueOf(&f).Elem().Set(fv)
  1525  
  1526  	// Call g with small arguments so that there is
  1527  	// something predictable (and different from the
  1528  	// correct results) in those positions on the stack.
  1529  	g := dummy
  1530  	g(1, 2, 3, two{4, 5}, 6, 7, 8)
  1531  
  1532  	// Call constructed function f.
  1533  	i, j, k, l, m, n, o := f(10, 20, 30, two{40, 50}, 60, 70, 80)
  1534  	if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 {
  1535  		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)
  1536  	}
  1537  }
  1538  
  1539  func TestMakeFuncInterface(t *testing.T) {
  1540  	fn := func(i int) int { return i }
  1541  	incr := func(in []Value) []Value {
  1542  		return []Value{ValueOf(int(in[0].Int() + 1))}
  1543  	}
  1544  	fv := MakeFunc(TypeOf(fn), incr)
  1545  	ValueOf(&fn).Elem().Set(fv)
  1546  	if r := fn(2); r != 3 {
  1547  		t.Errorf("Call returned %d, want 3", r)
  1548  	}
  1549  	if r := fv.Call([]Value{ValueOf(14)})[0].Int(); r != 15 {
  1550  		t.Errorf("Call returned %d, want 15", r)
  1551  	}
  1552  	if r := fv.Interface().(func(int) int)(26); r != 27 {
  1553  		t.Errorf("Call returned %d, want 27", r)
  1554  	}
  1555  }
  1556  
  1557  func TestMakeFuncVariadic(t *testing.T) {
  1558  	// Test that variadic arguments are packed into a slice and passed as last arg
  1559  	fn := func(_ int, is ...int) []int { return nil }
  1560  	fv := MakeFunc(TypeOf(fn), func(in []Value) []Value { return in[1:2] })
  1561  	ValueOf(&fn).Elem().Set(fv)
  1562  
  1563  	r := fn(1, 2, 3)
  1564  	if r[0] != 2 || r[1] != 3 {
  1565  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  1566  	}
  1567  
  1568  	r = fn(1, []int{2, 3}...)
  1569  	if r[0] != 2 || r[1] != 3 {
  1570  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  1571  	}
  1572  
  1573  	r = fv.Call([]Value{ValueOf(1), ValueOf(2), ValueOf(3)})[0].Interface().([]int)
  1574  	if r[0] != 2 || r[1] != 3 {
  1575  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  1576  	}
  1577  
  1578  	r = fv.CallSlice([]Value{ValueOf(1), ValueOf([]int{2, 3})})[0].Interface().([]int)
  1579  	if r[0] != 2 || r[1] != 3 {
  1580  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  1581  	}
  1582  
  1583  	f := fv.Interface().(func(int, ...int) []int)
  1584  
  1585  	r = f(1, 2, 3)
  1586  	if r[0] != 2 || r[1] != 3 {
  1587  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  1588  	}
  1589  	r = f(1, []int{2, 3}...)
  1590  	if r[0] != 2 || r[1] != 3 {
  1591  		t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1])
  1592  	}
  1593  }
  1594  
  1595  type Point struct {
  1596  	x, y int
  1597  }
  1598  
  1599  // This will be index 0.
  1600  func (p Point) AnotherMethod(scale int) int {
  1601  	return -1
  1602  }
  1603  
  1604  // This will be index 1.
  1605  func (p Point) Dist(scale int) int {
  1606  	//println("Point.Dist", p.x, p.y, scale)
  1607  	return p.x*p.x*scale + p.y*p.y*scale
  1608  }
  1609  
  1610  // This will be index 2.
  1611  func (p Point) GCMethod(k int) int {
  1612  	runtime.GC()
  1613  	return k + p.x
  1614  }
  1615  
  1616  // This will be index 3.
  1617  func (p Point) TotalDist(points ...Point) int {
  1618  	tot := 0
  1619  	for _, q := range points {
  1620  		dx := q.x - p.x
  1621  		dy := q.y - p.y
  1622  		tot += dx*dx + dy*dy // Should call Sqrt, but it's just a test.
  1623  
  1624  	}
  1625  	return tot
  1626  }
  1627  
  1628  func TestMethod(t *testing.T) {
  1629  	// Non-curried method of type.
  1630  	p := Point{3, 4}
  1631  	i := TypeOf(p).Method(1).Func.Call([]Value{ValueOf(p), ValueOf(10)})[0].Int()
  1632  	if i != 250 {
  1633  		t.Errorf("Type Method returned %d; want 250", i)
  1634  	}
  1635  
  1636  	m, ok := TypeOf(p).MethodByName("Dist")
  1637  	if !ok {
  1638  		t.Fatalf("method by name failed")
  1639  	}
  1640  	i = m.Func.Call([]Value{ValueOf(p), ValueOf(11)})[0].Int()
  1641  	if i != 275 {
  1642  		t.Errorf("Type MethodByName returned %d; want 275", i)
  1643  	}
  1644  
  1645  	i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(12)})[0].Int()
  1646  	if i != 300 {
  1647  		t.Errorf("Pointer Type Method returned %d; want 300", i)
  1648  	}
  1649  
  1650  	m, ok = TypeOf(&p).MethodByName("Dist")
  1651  	if !ok {
  1652  		t.Fatalf("ptr method by name failed")
  1653  	}
  1654  	i = m.Func.Call([]Value{ValueOf(&p), ValueOf(13)})[0].Int()
  1655  	if i != 325 {
  1656  		t.Errorf("Pointer Type MethodByName returned %d; want 325", i)
  1657  	}
  1658  
  1659  	// Curried method of value.
  1660  	tfunc := TypeOf((func(int) int)(nil))
  1661  	v := ValueOf(p).Method(1)
  1662  	if tt := v.Type(); tt != tfunc {
  1663  		t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
  1664  	}
  1665  	i = v.Call([]Value{ValueOf(14)})[0].Int()
  1666  	if i != 350 {
  1667  		t.Errorf("Value Method returned %d; want 350", i)
  1668  	}
  1669  	v = ValueOf(p).MethodByName("Dist")
  1670  	if tt := v.Type(); tt != tfunc {
  1671  		t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
  1672  	}
  1673  	i = v.Call([]Value{ValueOf(15)})[0].Int()
  1674  	if i != 375 {
  1675  		t.Errorf("Value MethodByName returned %d; want 375", i)
  1676  	}
  1677  
  1678  	// Curried method of pointer.
  1679  	v = ValueOf(&p).Method(1)
  1680  	if tt := v.Type(); tt != tfunc {
  1681  		t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
  1682  	}
  1683  	i = v.Call([]Value{ValueOf(16)})[0].Int()
  1684  	if i != 400 {
  1685  		t.Errorf("Pointer Value Method returned %d; want 400", i)
  1686  	}
  1687  	v = ValueOf(&p).MethodByName("Dist")
  1688  	if tt := v.Type(); tt != tfunc {
  1689  		t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  1690  	}
  1691  	i = v.Call([]Value{ValueOf(17)})[0].Int()
  1692  	if i != 425 {
  1693  		t.Errorf("Pointer Value MethodByName returned %d; want 425", i)
  1694  	}
  1695  
  1696  	// Curried method of interface value.
  1697  	// Have to wrap interface value in a struct to get at it.
  1698  	// Passing it to ValueOf directly would
  1699  	// access the underlying Point, not the interface.
  1700  	var x interface {
  1701  		Dist(int) int
  1702  	} = p
  1703  	pv := ValueOf(&x).Elem()
  1704  	v = pv.Method(0)
  1705  	if tt := v.Type(); tt != tfunc {
  1706  		t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
  1707  	}
  1708  	i = v.Call([]Value{ValueOf(18)})[0].Int()
  1709  	if i != 450 {
  1710  		t.Errorf("Interface Method returned %d; want 450", i)
  1711  	}
  1712  	v = pv.MethodByName("Dist")
  1713  	if tt := v.Type(); tt != tfunc {
  1714  		t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
  1715  	}
  1716  	i = v.Call([]Value{ValueOf(19)})[0].Int()
  1717  	if i != 475 {
  1718  		t.Errorf("Interface MethodByName returned %d; want 475", i)
  1719  	}
  1720  }
  1721  
  1722  func TestMethodValue(t *testing.T) {
  1723  	p := Point{3, 4}
  1724  	var i int64
  1725  
  1726  	// Curried method of value.
  1727  	tfunc := TypeOf((func(int) int)(nil))
  1728  	v := ValueOf(p).Method(1)
  1729  	if tt := v.Type(); tt != tfunc {
  1730  		t.Errorf("Value Method Type is %s; want %s", tt, tfunc)
  1731  	}
  1732  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(10)})[0].Int()
  1733  	if i != 250 {
  1734  		t.Errorf("Value Method returned %d; want 250", i)
  1735  	}
  1736  	v = ValueOf(p).MethodByName("Dist")
  1737  	if tt := v.Type(); tt != tfunc {
  1738  		t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc)
  1739  	}
  1740  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(11)})[0].Int()
  1741  	if i != 275 {
  1742  		t.Errorf("Value MethodByName returned %d; want 275", i)
  1743  	}
  1744  
  1745  	// Curried method of pointer.
  1746  	v = ValueOf(&p).Method(1)
  1747  	if tt := v.Type(); tt != tfunc {
  1748  		t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc)
  1749  	}
  1750  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(12)})[0].Int()
  1751  	if i != 300 {
  1752  		t.Errorf("Pointer Value Method returned %d; want 300", i)
  1753  	}
  1754  	v = ValueOf(&p).MethodByName("Dist")
  1755  	if tt := v.Type(); tt != tfunc {
  1756  		t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  1757  	}
  1758  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(13)})[0].Int()
  1759  	if i != 325 {
  1760  		t.Errorf("Pointer Value MethodByName returned %d; want 325", i)
  1761  	}
  1762  
  1763  	// Curried method of pointer to pointer.
  1764  	pp := &p
  1765  	v = ValueOf(&pp).Elem().Method(1)
  1766  	if tt := v.Type(); tt != tfunc {
  1767  		t.Errorf("Pointer Pointer Value Method Type is %s; want %s", tt, tfunc)
  1768  	}
  1769  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(14)})[0].Int()
  1770  	if i != 350 {
  1771  		t.Errorf("Pointer Pointer Value Method returned %d; want 350", i)
  1772  	}
  1773  	v = ValueOf(&pp).Elem().MethodByName("Dist")
  1774  	if tt := v.Type(); tt != tfunc {
  1775  		t.Errorf("Pointer Pointer Value MethodByName Type is %s; want %s", tt, tfunc)
  1776  	}
  1777  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(15)})[0].Int()
  1778  	if i != 375 {
  1779  		t.Errorf("Pointer Pointer Value MethodByName returned %d; want 375", i)
  1780  	}
  1781  
  1782  	// Curried method of interface value.
  1783  	// Have to wrap interface value in a struct to get at it.
  1784  	// Passing it to ValueOf directly would
  1785  	// access the underlying Point, not the interface.
  1786  	var s = struct {
  1787  		X interface {
  1788  			Dist(int) int
  1789  		}
  1790  	}{p}
  1791  	pv := ValueOf(s).Field(0)
  1792  	v = pv.Method(0)
  1793  	if tt := v.Type(); tt != tfunc {
  1794  		t.Errorf("Interface Method Type is %s; want %s", tt, tfunc)
  1795  	}
  1796  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(16)})[0].Int()
  1797  	if i != 400 {
  1798  		t.Errorf("Interface Method returned %d; want 400", i)
  1799  	}
  1800  	v = pv.MethodByName("Dist")
  1801  	if tt := v.Type(); tt != tfunc {
  1802  		t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc)
  1803  	}
  1804  	i = ValueOf(v.Interface()).Call([]Value{ValueOf(17)})[0].Int()
  1805  	if i != 425 {
  1806  		t.Errorf("Interface MethodByName returned %d; want 425", i)
  1807  	}
  1808  }
  1809  
  1810  func TestVariadicMethodValue(t *testing.T) {
  1811  	p := Point{3, 4}
  1812  	points := []Point{{20, 21}, {22, 23}, {24, 25}}
  1813  	want := int64(p.TotalDist(points[0], points[1], points[2]))
  1814  
  1815  	// Curried method of value.
  1816  	tfunc := TypeOf((func(...Point) int)(nil))
  1817  	v := ValueOf(p).Method(3)
  1818  	if tt := v.Type(); tt != tfunc {
  1819  		t.Errorf("Variadic Method Type is %s; want %s", tt, tfunc)
  1820  	}
  1821  	i := ValueOf(v.Interface()).Call([]Value{ValueOf(points[0]), ValueOf(points[1]), ValueOf(points[2])})[0].Int()
  1822  	if i != want {
  1823  		t.Errorf("Variadic Method returned %d; want %d", i, want)
  1824  	}
  1825  	i = ValueOf(v.Interface()).CallSlice([]Value{ValueOf(points)})[0].Int()
  1826  	if i != want {
  1827  		t.Errorf("Variadic Method CallSlice returned %d; want %d", i, want)
  1828  	}
  1829  
  1830  	f := v.Interface().(func(...Point) int)
  1831  	i = int64(f(points[0], points[1], points[2]))
  1832  	if i != want {
  1833  		t.Errorf("Variadic Method Interface returned %d; want %d", i, want)
  1834  	}
  1835  	i = int64(f(points...))
  1836  	if i != want {
  1837  		t.Errorf("Variadic Method Interface Slice returned %d; want %d", i, want)
  1838  	}
  1839  }
  1840  
  1841  // Reflect version of $GOROOT/test/method5.go
  1842  
  1843  // Concrete types implementing M method.
  1844  // Smaller than a word, word-sized, larger than a word.
  1845  // Value and pointer receivers.
  1846  
  1847  type Tinter interface {
  1848  	M(int, byte) (byte, int)
  1849  }
  1850  
  1851  type Tsmallv byte
  1852  
  1853  func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x + int(v) }
  1854  
  1855  type Tsmallp byte
  1856  
  1857  func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
  1858  
  1859  type Twordv uintptr
  1860  
  1861  func (v Twordv) M(x int, b byte) (byte, int) { return b, x + int(v) }
  1862  
  1863  type Twordp uintptr
  1864  
  1865  func (p *Twordp) M(x int, b byte) (byte, int) { return b, x + int(*p) }
  1866  
  1867  type Tbigv [2]uintptr
  1868  
  1869  func (v Tbigv) M(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) }
  1870  
  1871  type Tbigp [2]uintptr
  1872  
  1873  func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) }
  1874  
  1875  // Again, with an unexported method.
  1876  
  1877  type tsmallv byte
  1878  
  1879  func (v tsmallv) m(x int, b byte) (byte, int) { return b, x + int(v) }
  1880  
  1881  type tsmallp byte
  1882  
  1883  func (p *tsmallp) m(x int, b byte) (byte, int) { return b, x + int(*p) }
  1884  
  1885  type twordv uintptr
  1886  
  1887  func (v twordv) m(x int, b byte) (byte, int) { return b, x + int(v) }
  1888  
  1889  type twordp uintptr
  1890  
  1891  func (p *twordp) m(x int, b byte) (byte, int) { return b, x + int(*p) }
  1892  
  1893  type tbigv [2]uintptr
  1894  
  1895  func (v tbigv) m(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) }
  1896  
  1897  type tbigp [2]uintptr
  1898  
  1899  func (p *tbigp) m(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) }
  1900  
  1901  type tinter interface {
  1902  	m(int, byte) (byte, int)
  1903  }
  1904  
  1905  // Embedding via pointer.
  1906  
  1907  type Tm1 struct {
  1908  	Tm2
  1909  }
  1910  
  1911  type Tm2 struct {
  1912  	*Tm3
  1913  }
  1914  
  1915  type Tm3 struct {
  1916  	*Tm4
  1917  }
  1918  
  1919  type Tm4 struct {
  1920  }
  1921  
  1922  func (t4 Tm4) M(x int, b byte) (byte, int) { return b, x + 40 }
  1923  
  1924  func TestMethod5(t *testing.T) {
  1925  	CheckF := func(name string, f func(int, byte) (byte, int), inc int) {
  1926  		b, x := f(1000, 99)
  1927  		if b != 99 || x != 1000+inc {
  1928  			t.Errorf("%s(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
  1929  		}
  1930  	}
  1931  
  1932  	CheckV := func(name string, i Value, inc int) {
  1933  		bx := i.Method(0).Call([]Value{ValueOf(1000), ValueOf(byte(99))})
  1934  		b := bx[0].Interface()
  1935  		x := bx[1].Interface()
  1936  		if b != byte(99) || x != 1000+inc {
  1937  			t.Errorf("direct %s.M(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc)
  1938  		}
  1939  
  1940  		CheckF(name+".M", i.Method(0).Interface().(func(int, byte) (byte, int)), inc)
  1941  	}
  1942  
  1943  	var TinterType = TypeOf(new(Tinter)).Elem()
  1944  	var tinterType = TypeOf(new(tinter)).Elem()
  1945  
  1946  	CheckI := func(name string, i interface{}, inc int) {
  1947  		v := ValueOf(i)
  1948  		CheckV(name, v, inc)
  1949  		CheckV("(i="+name+")", v.Convert(TinterType), inc)
  1950  	}
  1951  
  1952  	sv := Tsmallv(1)
  1953  	CheckI("sv", sv, 1)
  1954  	CheckI("&sv", &sv, 1)
  1955  
  1956  	sp := Tsmallp(2)
  1957  	CheckI("&sp", &sp, 2)
  1958  
  1959  	wv := Twordv(3)
  1960  	CheckI("wv", wv, 3)
  1961  	CheckI("&wv", &wv, 3)
  1962  
  1963  	wp := Twordp(4)
  1964  	CheckI("&wp", &wp, 4)
  1965  
  1966  	bv := Tbigv([2]uintptr{5, 6})
  1967  	CheckI("bv", bv, 11)
  1968  	CheckI("&bv", &bv, 11)
  1969  
  1970  	bp := Tbigp([2]uintptr{7, 8})
  1971  	CheckI("&bp", &bp, 15)
  1972  
  1973  	t4 := Tm4{}
  1974  	t3 := Tm3{&t4}
  1975  	t2 := Tm2{&t3}
  1976  	t1 := Tm1{t2}
  1977  	CheckI("t4", t4, 40)
  1978  	CheckI("&t4", &t4, 40)
  1979  	CheckI("t3", t3, 40)
  1980  	CheckI("&t3", &t3, 40)
  1981  	CheckI("t2", t2, 40)
  1982  	CheckI("&t2", &t2, 40)
  1983  	CheckI("t1", t1, 40)
  1984  	CheckI("&t1", &t1, 40)
  1985  
  1986  	methodShouldPanic := func(name string, i interface{}) {
  1987  		v := ValueOf(i)
  1988  		m := v.Method(0)
  1989  		shouldPanic(func() { m.Call([]Value{ValueOf(1000), ValueOf(byte(99))}) })
  1990  		shouldPanic(func() { m.Interface() })
  1991  
  1992  		v = v.Convert(tinterType)
  1993  		m = v.Method(0)
  1994  		shouldPanic(func() { m.Call([]Value{ValueOf(1000), ValueOf(byte(99))}) })
  1995  		shouldPanic(func() { m.Interface() })
  1996  	}
  1997  
  1998  	_sv := tsmallv(1)
  1999  	methodShouldPanic("_sv", _sv)
  2000  	methodShouldPanic("&_sv", &_sv)
  2001  
  2002  	_sp := tsmallp(2)
  2003  	methodShouldPanic("&_sp", &_sp)
  2004  
  2005  	_wv := twordv(3)
  2006  	methodShouldPanic("_wv", _wv)
  2007  	methodShouldPanic("&_wv", &_wv)
  2008  
  2009  	_wp := twordp(4)
  2010  	methodShouldPanic("&_wp", &_wp)
  2011  
  2012  	_bv := tbigv([2]uintptr{5, 6})
  2013  	methodShouldPanic("_bv", _bv)
  2014  	methodShouldPanic("&_bv", &_bv)
  2015  
  2016  	_bp := tbigp([2]uintptr{7, 8})
  2017  	methodShouldPanic("&_bp", &_bp)
  2018  
  2019  	var tnil Tinter
  2020  	vnil := ValueOf(&tnil).Elem()
  2021  	shouldPanic(func() { vnil.Method(0) })
  2022  }
  2023  
  2024  func TestInterfaceSet(t *testing.T) {
  2025  	p := &Point{3, 4}
  2026  
  2027  	var s struct {
  2028  		I interface{}
  2029  		P interface {
  2030  			Dist(int) int
  2031  		}
  2032  	}
  2033  	sv := ValueOf(&s).Elem()
  2034  	sv.Field(0).Set(ValueOf(p))
  2035  	if q := s.I.(*Point); q != p {
  2036  		t.Errorf("i: have %p want %p", q, p)
  2037  	}
  2038  
  2039  	pv := sv.Field(1)
  2040  	pv.Set(ValueOf(p))
  2041  	if q := s.P.(*Point); q != p {
  2042  		t.Errorf("i: have %p want %p", q, p)
  2043  	}
  2044  
  2045  	i := pv.Method(0).Call([]Value{ValueOf(10)})[0].Int()
  2046  	if i != 250 {
  2047  		t.Errorf("Interface Method returned %d; want 250", i)
  2048  	}
  2049  }
  2050  
  2051  type T1 struct {
  2052  	a string
  2053  	int
  2054  }
  2055  
  2056  func TestAnonymousFields(t *testing.T) {
  2057  	var field StructField
  2058  	var ok bool
  2059  	var t1 T1
  2060  	type1 := TypeOf(t1)
  2061  	if field, ok = type1.FieldByName("int"); !ok {
  2062  		t.Fatal("no field 'int'")
  2063  	}
  2064  	if field.Index[0] != 1 {
  2065  		t.Error("field index should be 1; is", field.Index)
  2066  	}
  2067  }
  2068  
  2069  type FTest struct {
  2070  	s     interface{}
  2071  	name  string
  2072  	index []int
  2073  	value int
  2074  }
  2075  
  2076  type D1 struct {
  2077  	d int
  2078  }
  2079  type D2 struct {
  2080  	d int
  2081  }
  2082  
  2083  type S0 struct {
  2084  	A, B, C int
  2085  	D1
  2086  	D2
  2087  }
  2088  
  2089  type S1 struct {
  2090  	B int
  2091  	S0
  2092  }
  2093  
  2094  type S2 struct {
  2095  	A int
  2096  	*S1
  2097  }
  2098  
  2099  type S1x struct {
  2100  	S1
  2101  }
  2102  
  2103  type S1y struct {
  2104  	S1
  2105  }
  2106  
  2107  type S3 struct {
  2108  	S1x
  2109  	S2
  2110  	D, E int
  2111  	*S1y
  2112  }
  2113  
  2114  type S4 struct {
  2115  	*S4
  2116  	A int
  2117  }
  2118  
  2119  // The X in S6 and S7 annihilate, but they also block the X in S8.S9.
  2120  type S5 struct {
  2121  	S6
  2122  	S7
  2123  	S8
  2124  }
  2125  
  2126  type S6 struct {
  2127  	X int
  2128  }
  2129  
  2130  type S7 S6
  2131  
  2132  type S8 struct {
  2133  	S9
  2134  }
  2135  
  2136  type S9 struct {
  2137  	X int
  2138  	Y int
  2139  }
  2140  
  2141  // The X in S11.S6 and S12.S6 annihilate, but they also block the X in S13.S8.S9.
  2142  type S10 struct {
  2143  	S11
  2144  	S12
  2145  	S13
  2146  }
  2147  
  2148  type S11 struct {
  2149  	S6
  2150  }
  2151  
  2152  type S12 struct {
  2153  	S6
  2154  }
  2155  
  2156  type S13 struct {
  2157  	S8
  2158  }
  2159  
  2160  // The X in S15.S11.S1 and S16.S11.S1 annihilate.
  2161  type S14 struct {
  2162  	S15
  2163  	S16
  2164  }
  2165  
  2166  type S15 struct {
  2167  	S11
  2168  }
  2169  
  2170  type S16 struct {
  2171  	S11
  2172  }
  2173  
  2174  var fieldTests = []FTest{
  2175  	{struct{}{}, "", nil, 0},
  2176  	{struct{}{}, "Foo", nil, 0},
  2177  	{S0{A: 'a'}, "A", []int{0}, 'a'},
  2178  	{S0{}, "D", nil, 0},
  2179  	{S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'},
  2180  	{S1{B: 'b'}, "B", []int{0}, 'b'},
  2181  	{S1{}, "S0", []int{1}, 0},
  2182  	{S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'},
  2183  	{S2{A: 'a'}, "A", []int{0}, 'a'},
  2184  	{S2{}, "S1", []int{1}, 0},
  2185  	{S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'},
  2186  	{S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'},
  2187  	{S2{}, "D", nil, 0},
  2188  	{S3{}, "S1", nil, 0},
  2189  	{S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'},
  2190  	{S3{}, "B", nil, 0},
  2191  	{S3{D: 'd'}, "D", []int{2}, 0},
  2192  	{S3{E: 'e'}, "E", []int{3}, 'e'},
  2193  	{S4{A: 'a'}, "A", []int{1}, 'a'},
  2194  	{S4{}, "B", nil, 0},
  2195  	{S5{}, "X", nil, 0},
  2196  	{S5{}, "Y", []int{2, 0, 1}, 0},
  2197  	{S10{}, "X", nil, 0},
  2198  	{S10{}, "Y", []int{2, 0, 0, 1}, 0},
  2199  	{S14{}, "X", nil, 0},
  2200  }
  2201  
  2202  func TestFieldByIndex(t *testing.T) {
  2203  	for _, test := range fieldTests {
  2204  		s := TypeOf(test.s)
  2205  		f := s.FieldByIndex(test.index)
  2206  		if f.Name != "" {
  2207  			if test.index != nil {
  2208  				if f.Name != test.name {
  2209  					t.Errorf("%s.%s found; want %s", s.Name(), f.Name, test.name)
  2210  				}
  2211  			} else {
  2212  				t.Errorf("%s.%s found", s.Name(), f.Name)
  2213  			}
  2214  		} else if len(test.index) > 0 {
  2215  			t.Errorf("%s.%s not found", s.Name(), test.name)
  2216  		}
  2217  
  2218  		if test.value != 0 {
  2219  			v := ValueOf(test.s).FieldByIndex(test.index)
  2220  			if v.IsValid() {
  2221  				if x, ok := v.Interface().(int); ok {
  2222  					if x != test.value {
  2223  						t.Errorf("%s%v is %d; want %d", s.Name(), test.index, x, test.value)
  2224  					}
  2225  				} else {
  2226  					t.Errorf("%s%v value not an int", s.Name(), test.index)
  2227  				}
  2228  			} else {
  2229  				t.Errorf("%s%v value not found", s.Name(), test.index)
  2230  			}
  2231  		}
  2232  	}
  2233  }
  2234  
  2235  func TestFieldByName(t *testing.T) {
  2236  	for _, test := range fieldTests {
  2237  		s := TypeOf(test.s)
  2238  		f, found := s.FieldByName(test.name)
  2239  		if found {
  2240  			if test.index != nil {
  2241  				// Verify field depth and index.
  2242  				if len(f.Index) != len(test.index) {
  2243  					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)
  2244  				} else {
  2245  					for i, x := range f.Index {
  2246  						if x != test.index[i] {
  2247  							t.Errorf("%s.%s.Index[%d] is %d; want %d", s.Name(), test.name, i, x, test.index[i])
  2248  						}
  2249  					}
  2250  				}
  2251  			} else {
  2252  				t.Errorf("%s.%s found", s.Name(), f.Name)
  2253  			}
  2254  		} else if len(test.index) > 0 {
  2255  			t.Errorf("%s.%s not found", s.Name(), test.name)
  2256  		}
  2257  
  2258  		if test.value != 0 {
  2259  			v := ValueOf(test.s).FieldByName(test.name)
  2260  			if v.IsValid() {
  2261  				if x, ok := v.Interface().(int); ok {
  2262  					if x != test.value {
  2263  						t.Errorf("%s.%s is %d; want %d", s.Name(), test.name, x, test.value)
  2264  					}
  2265  				} else {
  2266  					t.Errorf("%s.%s value not an int", s.Name(), test.name)
  2267  				}
  2268  			} else {
  2269  				t.Errorf("%s.%s value not found", s.Name(), test.name)
  2270  			}
  2271  		}
  2272  	}
  2273  }
  2274  
  2275  func TestImportPath(t *testing.T) {
  2276  	tests := []struct {
  2277  		t    Type
  2278  		path string
  2279  	}{
  2280  		{TypeOf(&base64.Encoding{}).Elem(), "encoding/base64"},
  2281  		{TypeOf(int(0)), ""},
  2282  		{TypeOf(int8(0)), ""},
  2283  		{TypeOf(int16(0)), ""},
  2284  		{TypeOf(int32(0)), ""},
  2285  		{TypeOf(int64(0)), ""},
  2286  		{TypeOf(uint(0)), ""},
  2287  		{TypeOf(uint8(0)), ""},
  2288  		{TypeOf(uint16(0)), ""},
  2289  		{TypeOf(uint32(0)), ""},
  2290  		{TypeOf(uint64(0)), ""},
  2291  		{TypeOf(uintptr(0)), ""},
  2292  		{TypeOf(float32(0)), ""},
  2293  		{TypeOf(float64(0)), ""},
  2294  		{TypeOf(complex64(0)), ""},
  2295  		{TypeOf(complex128(0)), ""},
  2296  		{TypeOf(byte(0)), ""},
  2297  		{TypeOf(rune(0)), ""},
  2298  		{TypeOf([]byte(nil)), ""},
  2299  		{TypeOf([]rune(nil)), ""},
  2300  		{TypeOf(string("")), ""},
  2301  		{TypeOf((*interface{})(nil)).Elem(), ""},
  2302  		{TypeOf((*byte)(nil)), ""},
  2303  		{TypeOf((*rune)(nil)), ""},
  2304  		{TypeOf((*int64)(nil)), ""},
  2305  		{TypeOf(map[string]int{}), ""},
  2306  		{TypeOf((*error)(nil)).Elem(), ""},
  2307  	}
  2308  	for _, test := range tests {
  2309  		if path := test.t.PkgPath(); path != test.path {
  2310  			t.Errorf("%v.PkgPath() = %q, want %q", test.t, path, test.path)
  2311  		}
  2312  	}
  2313  }
  2314  
  2315  func TestVariadicType(t *testing.T) {
  2316  	// Test example from Type documentation.
  2317  	var f func(x int, y ...float64)
  2318  	typ := TypeOf(f)
  2319  	if typ.NumIn() == 2 && typ.In(0) == TypeOf(int(0)) {
  2320  		sl := typ.In(1)
  2321  		if sl.Kind() == Slice {
  2322  			if sl.Elem() == TypeOf(0.0) {
  2323  				// ok
  2324  				return
  2325  			}
  2326  		}
  2327  	}
  2328  
  2329  	// Failed
  2330  	t.Errorf("want NumIn() = 2, In(0) = int, In(1) = []float64")
  2331  	s := fmt.Sprintf("have NumIn() = %d", typ.NumIn())
  2332  	for i := 0; i < typ.NumIn(); i++ {
  2333  		s += fmt.Sprintf(", In(%d) = %s", i, typ.In(i))
  2334  	}
  2335  	t.Error(s)
  2336  }
  2337  
  2338  type inner struct {
  2339  	x int
  2340  }
  2341  
  2342  type outer struct {
  2343  	y int
  2344  	inner
  2345  }
  2346  
  2347  func (*inner) m() {}
  2348  func (*outer) m() {}
  2349  
  2350  func TestNestedMethods(t *testing.T) {
  2351  	typ := TypeOf((*outer)(nil))
  2352  	if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*outer).m).Pointer() {
  2353  		t.Errorf("Wrong method table for outer: (m=%p)", (*outer).m)
  2354  		for i := 0; i < typ.NumMethod(); i++ {
  2355  			m := typ.Method(i)
  2356  			t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer())
  2357  		}
  2358  	}
  2359  }
  2360  
  2361  type InnerInt struct {
  2362  	X int
  2363  }
  2364  
  2365  type OuterInt struct {
  2366  	Y int
  2367  	InnerInt
  2368  }
  2369  
  2370  func (i *InnerInt) M() int {
  2371  	return i.X
  2372  }
  2373  
  2374  func TestEmbeddedMethods(t *testing.T) {
  2375  	typ := TypeOf((*OuterInt)(nil))
  2376  	if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*OuterInt).M).Pointer() {
  2377  		t.Errorf("Wrong method table for OuterInt: (m=%p)", (*OuterInt).M)
  2378  		for i := 0; i < typ.NumMethod(); i++ {
  2379  			m := typ.Method(i)
  2380  			t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer())
  2381  		}
  2382  	}
  2383  
  2384  	i := &InnerInt{3}
  2385  	if v := ValueOf(i).Method(0).Call(nil)[0].Int(); v != 3 {
  2386  		t.Errorf("i.M() = %d, want 3", v)
  2387  	}
  2388  
  2389  	o := &OuterInt{1, InnerInt{2}}
  2390  	if v := ValueOf(o).Method(0).Call(nil)[0].Int(); v != 2 {
  2391  		t.Errorf("i.M() = %d, want 2", v)
  2392  	}
  2393  
  2394  	f := (*OuterInt).M
  2395  	if v := f(o); v != 2 {
  2396  		t.Errorf("f(o) = %d, want 2", v)
  2397  	}
  2398  }
  2399  
  2400  func TestPtrTo(t *testing.T) {
  2401  	var i int
  2402  
  2403  	typ := TypeOf(i)
  2404  	for i = 0; i < 100; i++ {
  2405  		typ = PtrTo(typ)
  2406  	}
  2407  	for i = 0; i < 100; i++ {
  2408  		typ = typ.Elem()
  2409  	}
  2410  	if typ != TypeOf(i) {
  2411  		t.Errorf("after 100 PtrTo and Elem, have %s, want %s", typ, TypeOf(i))
  2412  	}
  2413  }
  2414  
  2415  func TestPtrToGC(t *testing.T) {
  2416  	type T *uintptr
  2417  	tt := TypeOf(T(nil))
  2418  	pt := PtrTo(tt)
  2419  	const n = 100
  2420  	var x []interface{}
  2421  	for i := 0; i < n; i++ {
  2422  		v := New(pt)
  2423  		p := new(*uintptr)
  2424  		*p = new(uintptr)
  2425  		**p = uintptr(i)
  2426  		v.Elem().Set(ValueOf(p).Convert(pt))
  2427  		x = append(x, v.Interface())
  2428  	}
  2429  	runtime.GC()
  2430  
  2431  	for i, xi := range x {
  2432  		k := ValueOf(xi).Elem().Elem().Elem().Interface().(uintptr)
  2433  		if k != uintptr(i) {
  2434  			t.Errorf("lost x[%d] = %d, want %d", i, k, i)
  2435  		}
  2436  	}
  2437  }
  2438  
  2439  func TestAddr(t *testing.T) {
  2440  	var p struct {
  2441  		X, Y int
  2442  	}
  2443  
  2444  	v := ValueOf(&p)
  2445  	v = v.Elem()
  2446  	v = v.Addr()
  2447  	v = v.Elem()
  2448  	v = v.Field(0)
  2449  	v.SetInt(2)
  2450  	if p.X != 2 {
  2451  		t.Errorf("Addr.Elem.Set failed to set value")
  2452  	}
  2453  
  2454  	// Again but take address of the ValueOf value.
  2455  	// Exercises generation of PtrTypes not present in the binary.
  2456  	q := &p
  2457  	v = ValueOf(&q).Elem()
  2458  	v = v.Addr()
  2459  	v = v.Elem()
  2460  	v = v.Elem()
  2461  	v = v.Addr()
  2462  	v = v.Elem()
  2463  	v = v.Field(0)
  2464  	v.SetInt(3)
  2465  	if p.X != 3 {
  2466  		t.Errorf("Addr.Elem.Set failed to set value")
  2467  	}
  2468  
  2469  	// Starting without pointer we should get changed value
  2470  	// in interface.
  2471  	qq := p
  2472  	v = ValueOf(&qq).Elem()
  2473  	v0 := v
  2474  	v = v.Addr()
  2475  	v = v.Elem()
  2476  	v = v.Field(0)
  2477  	v.SetInt(4)
  2478  	if p.X != 3 { // should be unchanged from last time
  2479  		t.Errorf("somehow value Set changed original p")
  2480  	}
  2481  	p = v0.Interface().(struct {
  2482  		X, Y int
  2483  	})
  2484  	if p.X != 4 {
  2485  		t.Errorf("Addr.Elem.Set valued to set value in top value")
  2486  	}
  2487  
  2488  	// Verify that taking the address of a type gives us a pointer
  2489  	// which we can convert back using the usual interface
  2490  	// notation.
  2491  	var s struct {
  2492  		B *bool
  2493  	}
  2494  	ps := ValueOf(&s).Elem().Field(0).Addr().Interface()
  2495  	*(ps.(**bool)) = new(bool)
  2496  	if s.B == nil {
  2497  		t.Errorf("Addr.Interface direct assignment failed")
  2498  	}
  2499  }
  2500  
  2501  func noAlloc(t *testing.T, n int, f func(int)) {
  2502  	if testing.Short() {
  2503  		t.Skip("skipping malloc count in short mode")
  2504  	}
  2505  	if runtime.GOMAXPROCS(0) > 1 {
  2506  		t.Skip("skipping; GOMAXPROCS>1")
  2507  	}
  2508  	i := -1
  2509  	allocs := testing.AllocsPerRun(n, func() {
  2510  		f(i)
  2511  		i++
  2512  	})
  2513  	if allocs > 0 {
  2514  		t.Errorf("%d iterations: got %v mallocs, want 0", n, allocs)
  2515  	}
  2516  }
  2517  
  2518  func TestAllocations(t *testing.T) {
  2519  	noAlloc(t, 100, func(j int) {
  2520  		var i interface{}
  2521  		var v Value
  2522  
  2523  		// We can uncomment this when compiler escape analysis
  2524  		// is good enough to see that the integer assigned to i
  2525  		// does not escape and therefore need not be allocated.
  2526  		//
  2527  		// i = 42 + j
  2528  		// v = ValueOf(i)
  2529  		// if int(v.Int()) != 42+j {
  2530  		// 	panic("wrong int")
  2531  		// }
  2532  
  2533  		i = func(j int) int { return j }
  2534  		v = ValueOf(i)
  2535  		if v.Interface().(func(int) int)(j) != j {
  2536  			panic("wrong result")
  2537  		}
  2538  	})
  2539  }
  2540  
  2541  func TestSmallNegativeInt(t *testing.T) {
  2542  	i := int16(-1)
  2543  	v := ValueOf(i)
  2544  	if v.Int() != -1 {
  2545  		t.Errorf("int16(-1).Int() returned %v", v.Int())
  2546  	}
  2547  }
  2548  
  2549  func TestIndex(t *testing.T) {
  2550  	xs := []byte{1, 2, 3, 4, 5, 6, 7, 8}
  2551  	v := ValueOf(xs).Index(3).Interface().(byte)
  2552  	if v != xs[3] {
  2553  		t.Errorf("xs.Index(3) = %v; expected %v", v, xs[3])
  2554  	}
  2555  	xa := [8]byte{10, 20, 30, 40, 50, 60, 70, 80}
  2556  	v = ValueOf(xa).Index(2).Interface().(byte)
  2557  	if v != xa[2] {
  2558  		t.Errorf("xa.Index(2) = %v; expected %v", v, xa[2])
  2559  	}
  2560  	s := "0123456789"
  2561  	v = ValueOf(s).Index(3).Interface().(byte)
  2562  	if v != s[3] {
  2563  		t.Errorf("s.Index(3) = %v; expected %v", v, s[3])
  2564  	}
  2565  }
  2566  
  2567  func TestSlice(t *testing.T) {
  2568  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  2569  	v := ValueOf(xs).Slice(3, 5).Interface().([]int)
  2570  	if len(v) != 2 {
  2571  		t.Errorf("len(xs.Slice(3, 5)) = %d", len(v))
  2572  	}
  2573  	if cap(v) != 5 {
  2574  		t.Errorf("cap(xs.Slice(3, 5)) = %d", cap(v))
  2575  	}
  2576  	if !DeepEqual(v[0:5], xs[3:]) {
  2577  		t.Errorf("xs.Slice(3, 5)[0:5] = %v", v[0:5])
  2578  	}
  2579  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  2580  	v = ValueOf(&xa).Elem().Slice(2, 5).Interface().([]int)
  2581  	if len(v) != 3 {
  2582  		t.Errorf("len(xa.Slice(2, 5)) = %d", len(v))
  2583  	}
  2584  	if cap(v) != 6 {
  2585  		t.Errorf("cap(xa.Slice(2, 5)) = %d", cap(v))
  2586  	}
  2587  	if !DeepEqual(v[0:6], xa[2:]) {
  2588  		t.Errorf("xs.Slice(2, 5)[0:6] = %v", v[0:6])
  2589  	}
  2590  	s := "0123456789"
  2591  	vs := ValueOf(s).Slice(3, 5).Interface().(string)
  2592  	if vs != s[3:5] {
  2593  		t.Errorf("s.Slice(3, 5) = %q; expected %q", vs, s[3:5])
  2594  	}
  2595  
  2596  	rv := ValueOf(&xs).Elem()
  2597  	rv = rv.Slice(3, 4)
  2598  	ptr2 := rv.Pointer()
  2599  	rv = rv.Slice(5, 5)
  2600  	ptr3 := rv.Pointer()
  2601  	if ptr3 != ptr2 {
  2602  		t.Errorf("xs.Slice(3,4).Slice3(5,5).Pointer() = %#x, want %#x", ptr3, ptr2)
  2603  	}
  2604  }
  2605  
  2606  func TestSlice3(t *testing.T) {
  2607  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  2608  	v := ValueOf(xs).Slice3(3, 5, 7).Interface().([]int)
  2609  	if len(v) != 2 {
  2610  		t.Errorf("len(xs.Slice3(3, 5, 7)) = %d", len(v))
  2611  	}
  2612  	if cap(v) != 4 {
  2613  		t.Errorf("cap(xs.Slice3(3, 5, 7)) = %d", cap(v))
  2614  	}
  2615  	if !DeepEqual(v[0:4], xs[3:7:7]) {
  2616  		t.Errorf("xs.Slice3(3, 5, 7)[0:4] = %v", v[0:4])
  2617  	}
  2618  	rv := ValueOf(&xs).Elem()
  2619  	shouldPanic(func() { rv.Slice3(1, 2, 1) })
  2620  	shouldPanic(func() { rv.Slice3(1, 1, 11) })
  2621  	shouldPanic(func() { rv.Slice3(2, 2, 1) })
  2622  
  2623  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  2624  	v = ValueOf(&xa).Elem().Slice3(2, 5, 6).Interface().([]int)
  2625  	if len(v) != 3 {
  2626  		t.Errorf("len(xa.Slice(2, 5, 6)) = %d", len(v))
  2627  	}
  2628  	if cap(v) != 4 {
  2629  		t.Errorf("cap(xa.Slice(2, 5, 6)) = %d", cap(v))
  2630  	}
  2631  	if !DeepEqual(v[0:4], xa[2:6:6]) {
  2632  		t.Errorf("xs.Slice(2, 5, 6)[0:4] = %v", v[0:4])
  2633  	}
  2634  	rv = ValueOf(&xa).Elem()
  2635  	shouldPanic(func() { rv.Slice3(1, 2, 1) })
  2636  	shouldPanic(func() { rv.Slice3(1, 1, 11) })
  2637  	shouldPanic(func() { rv.Slice3(2, 2, 1) })
  2638  
  2639  	s := "hello world"
  2640  	rv = ValueOf(&s).Elem()
  2641  	shouldPanic(func() { rv.Slice3(1, 2, 3) })
  2642  
  2643  	rv = ValueOf(&xs).Elem()
  2644  	rv = rv.Slice3(3, 5, 7)
  2645  	ptr2 := rv.Pointer()
  2646  	rv = rv.Slice3(4, 4, 4)
  2647  	ptr3 := rv.Pointer()
  2648  	if ptr3 != ptr2 {
  2649  		t.Errorf("xs.Slice3(3,5,7).Slice3(4,4,4).Pointer() = %#x, want %#x", ptr3, ptr2)
  2650  	}
  2651  }
  2652  
  2653  func TestSetLenCap(t *testing.T) {
  2654  	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
  2655  	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}
  2656  
  2657  	vs := ValueOf(&xs).Elem()
  2658  	shouldPanic(func() { vs.SetLen(10) })
  2659  	shouldPanic(func() { vs.SetCap(10) })
  2660  	shouldPanic(func() { vs.SetLen(-1) })
  2661  	shouldPanic(func() { vs.SetCap(-1) })
  2662  	shouldPanic(func() { vs.SetCap(6) }) // smaller than len
  2663  	vs.SetLen(5)
  2664  	if len(xs) != 5 || cap(xs) != 8 {
  2665  		t.Errorf("after SetLen(5), len, cap = %d, %d, want 5, 8", len(xs), cap(xs))
  2666  	}
  2667  	vs.SetCap(6)
  2668  	if len(xs) != 5 || cap(xs) != 6 {
  2669  		t.Errorf("after SetCap(6), len, cap = %d, %d, want 5, 6", len(xs), cap(xs))
  2670  	}
  2671  	vs.SetCap(5)
  2672  	if len(xs) != 5 || cap(xs) != 5 {
  2673  		t.Errorf("after SetCap(5), len, cap = %d, %d, want 5, 5", len(xs), cap(xs))
  2674  	}
  2675  	shouldPanic(func() { vs.SetCap(4) }) // smaller than len
  2676  	shouldPanic(func() { vs.SetLen(6) }) // bigger than cap
  2677  
  2678  	va := ValueOf(&xa).Elem()
  2679  	shouldPanic(func() { va.SetLen(8) })
  2680  	shouldPanic(func() { va.SetCap(8) })
  2681  }
  2682  
  2683  func TestVariadic(t *testing.T) {
  2684  	var b bytes.Buffer
  2685  	V := ValueOf
  2686  
  2687  	b.Reset()
  2688  	V(fmt.Fprintf).Call([]Value{V(&b), V("%s, %d world"), V("hello"), V(42)})
  2689  	if b.String() != "hello, 42 world" {
  2690  		t.Errorf("after Fprintf Call: %q != %q", b.String(), "hello 42 world")
  2691  	}
  2692  
  2693  	b.Reset()
  2694  	V(fmt.Fprintf).CallSlice([]Value{V(&b), V("%s, %d world"), V([]interface{}{"hello", 42})})
  2695  	if b.String() != "hello, 42 world" {
  2696  		t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world")
  2697  	}
  2698  }
  2699  
  2700  func TestFuncArg(t *testing.T) {
  2701  	f1 := func(i int, f func(int) int) int { return f(i) }
  2702  	f2 := func(i int) int { return i + 1 }
  2703  	r := ValueOf(f1).Call([]Value{ValueOf(100), ValueOf(f2)})
  2704  	if r[0].Int() != 101 {
  2705  		t.Errorf("function returned %d, want 101", r[0].Int())
  2706  	}
  2707  }
  2708  
  2709  func TestStructArg(t *testing.T) {
  2710  	type padded struct {
  2711  		B string
  2712  		C int32
  2713  	}
  2714  	var (
  2715  		gotA  padded
  2716  		gotB  uint32
  2717  		wantA = padded{"3", 4}
  2718  		wantB = uint32(5)
  2719  	)
  2720  	f := func(a padded, b uint32) {
  2721  		gotA, gotB = a, b
  2722  	}
  2723  	ValueOf(f).Call([]Value{ValueOf(wantA), ValueOf(wantB)})
  2724  	if gotA != wantA || gotB != wantB {
  2725  		t.Errorf("function called with (%v, %v), want (%v, %v)", gotA, gotB, wantA, wantB)
  2726  	}
  2727  }
  2728  
  2729  var tagGetTests = []struct {
  2730  	Tag   StructTag
  2731  	Key   string
  2732  	Value string
  2733  }{
  2734  	{`protobuf:"PB(1,2)"`, `protobuf`, `PB(1,2)`},
  2735  	{`protobuf:"PB(1,2)"`, `foo`, ``},
  2736  	{`protobuf:"PB(1,2)"`, `rotobuf`, ``},
  2737  	{`protobuf:"PB(1,2)" json:"name"`, `json`, `name`},
  2738  	{`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`},
  2739  	{`k0:"values contain spaces" k1:"and\ttabs"`, "k0", "values contain spaces"},
  2740  	{`k0:"values contain spaces" k1:"and\ttabs"`, "k1", "and\ttabs"},
  2741  }
  2742  
  2743  func TestTagGet(t *testing.T) {
  2744  	for _, tt := range tagGetTests {
  2745  		if v := tt.Tag.Get(tt.Key); v != tt.Value {
  2746  			t.Errorf("StructTag(%#q).Get(%#q) = %#q, want %#q", tt.Tag, tt.Key, v, tt.Value)
  2747  		}
  2748  	}
  2749  }
  2750  
  2751  func TestBytes(t *testing.T) {
  2752  	type B []byte
  2753  	x := B{1, 2, 3, 4}
  2754  	y := ValueOf(x).Bytes()
  2755  	if !bytes.Equal(x, y) {
  2756  		t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
  2757  	}
  2758  	if &x[0] != &y[0] {
  2759  		t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
  2760  	}
  2761  }
  2762  
  2763  func TestSetBytes(t *testing.T) {
  2764  	type B []byte
  2765  	var x B
  2766  	y := []byte{1, 2, 3, 4}
  2767  	ValueOf(&x).Elem().SetBytes(y)
  2768  	if !bytes.Equal(x, y) {
  2769  		t.Fatalf("ValueOf(%v).Bytes() = %v", x, y)
  2770  	}
  2771  	if &x[0] != &y[0] {
  2772  		t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0])
  2773  	}
  2774  }
  2775  
  2776  type Private struct {
  2777  	x int
  2778  	y **int
  2779  }
  2780  
  2781  func (p *Private) m() {
  2782  }
  2783  
  2784  type Public struct {
  2785  	X int
  2786  	Y **int
  2787  }
  2788  
  2789  func (p *Public) M() {
  2790  }
  2791  
  2792  func TestUnexported(t *testing.T) {
  2793  	var pub Public
  2794  	v := ValueOf(&pub)
  2795  	isValid(v.Elem().Field(0))
  2796  	isValid(v.Elem().Field(1))
  2797  	isValid(v.Elem().FieldByName("X"))
  2798  	isValid(v.Elem().FieldByName("Y"))
  2799  	isValid(v.Type().Method(0).Func)
  2800  	isNonNil(v.Elem().Field(0).Interface())
  2801  	isNonNil(v.Elem().Field(1).Interface())
  2802  	isNonNil(v.Elem().FieldByName("X").Interface())
  2803  	isNonNil(v.Elem().FieldByName("Y").Interface())
  2804  	isNonNil(v.Type().Method(0).Func.Interface())
  2805  
  2806  	var priv Private
  2807  	v = ValueOf(&priv)
  2808  	isValid(v.Elem().Field(0))
  2809  	isValid(v.Elem().Field(1))
  2810  	isValid(v.Elem().FieldByName("x"))
  2811  	isValid(v.Elem().FieldByName("y"))
  2812  	isValid(v.Type().Method(0).Func)
  2813  	shouldPanic(func() { v.Elem().Field(0).Interface() })
  2814  	shouldPanic(func() { v.Elem().Field(1).Interface() })
  2815  	shouldPanic(func() { v.Elem().FieldByName("x").Interface() })
  2816  	shouldPanic(func() { v.Elem().FieldByName("y").Interface() })
  2817  	shouldPanic(func() { v.Type().Method(0).Func.Interface() })
  2818  }
  2819  
  2820  func shouldPanic(f func()) {
  2821  	defer func() {
  2822  		if recover() == nil {
  2823  			panic("did not panic")
  2824  		}
  2825  	}()
  2826  	f()
  2827  }
  2828  
  2829  func isNonNil(x interface{}) {
  2830  	if x == nil {
  2831  		panic("nil interface")
  2832  	}
  2833  }
  2834  
  2835  func isValid(v Value) {
  2836  	if !v.IsValid() {
  2837  		panic("zero Value")
  2838  	}
  2839  }
  2840  
  2841  func TestAlias(t *testing.T) {
  2842  	x := string("hello")
  2843  	v := ValueOf(&x).Elem()
  2844  	oldvalue := v.Interface()
  2845  	v.SetString("world")
  2846  	newvalue := v.Interface()
  2847  
  2848  	if oldvalue != "hello" || newvalue != "world" {
  2849  		t.Errorf("aliasing: old=%q new=%q, want hello, world", oldvalue, newvalue)
  2850  	}
  2851  }
  2852  
  2853  var V = ValueOf
  2854  
  2855  func EmptyInterfaceV(x interface{}) Value {
  2856  	return ValueOf(&x).Elem()
  2857  }
  2858  
  2859  func ReaderV(x io.Reader) Value {
  2860  	return ValueOf(&x).Elem()
  2861  }
  2862  
  2863  func ReadWriterV(x io.ReadWriter) Value {
  2864  	return ValueOf(&x).Elem()
  2865  }
  2866  
  2867  type Empty struct{}
  2868  type MyString string
  2869  type MyBytes []byte
  2870  type MyRunes []int32
  2871  type MyFunc func()
  2872  type MyByte byte
  2873  
  2874  var convertTests = []struct {
  2875  	in  Value
  2876  	out Value
  2877  }{
  2878  	// numbers
  2879  	/*
  2880  		Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go
  2881  
  2882  		package main
  2883  
  2884  		import "fmt"
  2885  
  2886  		var numbers = []string{
  2887  			"int8", "uint8", "int16", "uint16",
  2888  			"int32", "uint32", "int64", "uint64",
  2889  			"int", "uint", "uintptr",
  2890  			"float32", "float64",
  2891  		}
  2892  
  2893  		func main() {
  2894  			// all pairs but in an unusual order,
  2895  			// to emit all the int8, uint8 cases
  2896  			// before n grows too big.
  2897  			n := 1
  2898  			for i, f := range numbers {
  2899  				for _, g := range numbers[i:] {
  2900  					fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n)
  2901  					n++
  2902  					if f != g {
  2903  						fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n)
  2904  						n++
  2905  					}
  2906  				}
  2907  			}
  2908  		}
  2909  	*/
  2910  	{V(int8(1)), V(int8(1))},
  2911  	{V(int8(2)), V(uint8(2))},
  2912  	{V(uint8(3)), V(int8(3))},
  2913  	{V(int8(4)), V(int16(4))},
  2914  	{V(int16(5)), V(int8(5))},
  2915  	{V(int8(6)), V(uint16(6))},
  2916  	{V(uint16(7)), V(int8(7))},
  2917  	{V(int8(8)), V(int32(8))},
  2918  	{V(int32(9)), V(int8(9))},
  2919  	{V(int8(10)), V(uint32(10))},
  2920  	{V(uint32(11)), V(int8(11))},
  2921  	{V(int8(12)), V(int64(12))},
  2922  	{V(int64(13)), V(int8(13))},
  2923  	{V(int8(14)), V(uint64(14))},
  2924  	{V(uint64(15)), V(int8(15))},
  2925  	{V(int8(16)), V(int(16))},
  2926  	{V(int(17)), V(int8(17))},
  2927  	{V(int8(18)), V(uint(18))},
  2928  	{V(uint(19)), V(int8(19))},
  2929  	{V(int8(20)), V(uintptr(20))},
  2930  	{V(uintptr(21)), V(int8(21))},
  2931  	{V(int8(22)), V(float32(22))},
  2932  	{V(float32(23)), V(int8(23))},
  2933  	{V(int8(24)), V(float64(24))},
  2934  	{V(float64(25)), V(int8(25))},
  2935  	{V(uint8(26)), V(uint8(26))},
  2936  	{V(uint8(27)), V(int16(27))},
  2937  	{V(int16(28)), V(uint8(28))},
  2938  	{V(uint8(29)), V(uint16(29))},
  2939  	{V(uint16(30)), V(uint8(30))},
  2940  	{V(uint8(31)), V(int32(31))},
  2941  	{V(int32(32)), V(uint8(32))},
  2942  	{V(uint8(33)), V(uint32(33))},
  2943  	{V(uint32(34)), V(uint8(34))},
  2944  	{V(uint8(35)), V(int64(35))},
  2945  	{V(int64(36)), V(uint8(36))},
  2946  	{V(uint8(37)), V(uint64(37))},
  2947  	{V(uint64(38)), V(uint8(38))},
  2948  	{V(uint8(39)), V(int(39))},
  2949  	{V(int(40)), V(uint8(40))},
  2950  	{V(uint8(41)), V(uint(41))},
  2951  	{V(uint(42)), V(uint8(42))},
  2952  	{V(uint8(43)), V(uintptr(43))},
  2953  	{V(uintptr(44)), V(uint8(44))},
  2954  	{V(uint8(45)), V(float32(45))},
  2955  	{V(float32(46)), V(uint8(46))},
  2956  	{V(uint8(47)), V(float64(47))},
  2957  	{V(float64(48)), V(uint8(48))},
  2958  	{V(int16(49)), V(int16(49))},
  2959  	{V(int16(50)), V(uint16(50))},
  2960  	{V(uint16(51)), V(int16(51))},
  2961  	{V(int16(52)), V(int32(52))},
  2962  	{V(int32(53)), V(int16(53))},
  2963  	{V(int16(54)), V(uint32(54))},
  2964  	{V(uint32(55)), V(int16(55))},
  2965  	{V(int16(56)), V(int64(56))},
  2966  	{V(int64(57)), V(int16(57))},
  2967  	{V(int16(58)), V(uint64(58))},
  2968  	{V(uint64(59)), V(int16(59))},
  2969  	{V(int16(60)), V(int(60))},
  2970  	{V(int(61)), V(int16(61))},
  2971  	{V(int16(62)), V(uint(62))},
  2972  	{V(uint(63)), V(int16(63))},
  2973  	{V(int16(64)), V(uintptr(64))},
  2974  	{V(uintptr(65)), V(int16(65))},
  2975  	{V(int16(66)), V(float32(66))},
  2976  	{V(float32(67)), V(int16(67))},
  2977  	{V(int16(68)), V(float64(68))},
  2978  	{V(float64(69)), V(int16(69))},
  2979  	{V(uint16(70)), V(uint16(70))},
  2980  	{V(uint16(71)), V(int32(71))},
  2981  	{V(int32(72)), V(uint16(72))},
  2982  	{V(uint16(73)), V(uint32(73))},
  2983  	{V(uint32(74)), V(uint16(74))},
  2984  	{V(uint16(75)), V(int64(75))},
  2985  	{V(int64(76)), V(uint16(76))},
  2986  	{V(uint16(77)), V(uint64(77))},
  2987  	{V(uint64(78)), V(uint16(78))},
  2988  	{V(uint16(79)), V(int(79))},
  2989  	{V(int(80)), V(uint16(80))},
  2990  	{V(uint16(81)), V(uint(81))},
  2991  	{V(uint(82)), V(uint16(82))},
  2992  	{V(uint16(83)), V(uintptr(83))},
  2993  	{V(uintptr(84)), V(uint16(84))},
  2994  	{V(uint16(85)), V(float32(85))},
  2995  	{V(float32(86)), V(uint16(86))},
  2996  	{V(uint16(87)), V(float64(87))},
  2997  	{V(float64(88)), V(uint16(88))},
  2998  	{V(int32(89)), V(int32(89))},
  2999  	{V(int32(90)), V(uint32(90))},
  3000  	{V(uint32(91)), V(int32(91))},
  3001  	{V(int32(92)), V(int64(92))},
  3002  	{V(int64(93)), V(int32(93))},
  3003  	{V(int32(94)), V(uint64(94))},
  3004  	{V(uint64(95)), V(int32(95))},
  3005  	{V(int32(96)), V(int(96))},
  3006  	{V(int(97)), V(int32(97))},
  3007  	{V(int32(98)), V(uint(98))},
  3008  	{V(uint(99)), V(int32(99))},
  3009  	{V(int32(100)), V(uintptr(100))},
  3010  	{V(uintptr(101)), V(int32(101))},
  3011  	{V(int32(102)), V(float32(102))},
  3012  	{V(float32(103)), V(int32(103))},
  3013  	{V(int32(104)), V(float64(104))},
  3014  	{V(float64(105)), V(int32(105))},
  3015  	{V(uint32(106)), V(uint32(106))},
  3016  	{V(uint32(107)), V(int64(107))},
  3017  	{V(int64(108)), V(uint32(108))},
  3018  	{V(uint32(109)), V(uint64(109))},
  3019  	{V(uint64(110)), V(uint32(110))},
  3020  	{V(uint32(111)), V(int(111))},
  3021  	{V(int(112)), V(uint32(112))},
  3022  	{V(uint32(113)), V(uint(113))},
  3023  	{V(uint(114)), V(uint32(114))},
  3024  	{V(uint32(115)), V(uintptr(115))},
  3025  	{V(uintptr(116)), V(uint32(116))},
  3026  	{V(uint32(117)), V(float32(117))},
  3027  	{V(float32(118)), V(uint32(118))},
  3028  	{V(uint32(119)), V(float64(119))},
  3029  	{V(float64(120)), V(uint32(120))},
  3030  	{V(int64(121)), V(int64(121))},
  3031  	{V(int64(122)), V(uint64(122))},
  3032  	{V(uint64(123)), V(int64(123))},
  3033  	{V(int64(124)), V(int(124))},
  3034  	{V(int(125)), V(int64(125))},
  3035  	{V(int64(126)), V(uint(126))},
  3036  	{V(uint(127)), V(int64(127))},
  3037  	{V(int64(128)), V(uintptr(128))},
  3038  	{V(uintptr(129)), V(int64(129))},
  3039  	{V(int64(130)), V(float32(130))},
  3040  	{V(float32(131)), V(int64(131))},
  3041  	{V(int64(132)), V(float64(132))},
  3042  	{V(float64(133)), V(int64(133))},
  3043  	{V(uint64(134)), V(uint64(134))},
  3044  	{V(uint64(135)), V(int(135))},
  3045  	{V(int(136)), V(uint64(136))},
  3046  	{V(uint64(137)), V(uint(137))},
  3047  	{V(uint(138)), V(uint64(138))},
  3048  	{V(uint64(139)), V(uintptr(139))},
  3049  	{V(uintptr(140)), V(uint64(140))},
  3050  	{V(uint64(141)), V(float32(141))},
  3051  	{V(float32(142)), V(uint64(142))},
  3052  	{V(uint64(143)), V(float64(143))},
  3053  	{V(float64(144)), V(uint64(144))},
  3054  	{V(int(145)), V(int(145))},
  3055  	{V(int(146)), V(uint(146))},
  3056  	{V(uint(147)), V(int(147))},
  3057  	{V(int(148)), V(uintptr(148))},
  3058  	{V(uintptr(149)), V(int(149))},
  3059  	{V(int(150)), V(float32(150))},
  3060  	{V(float32(151)), V(int(151))},
  3061  	{V(int(152)), V(float64(152))},
  3062  	{V(float64(153)), V(int(153))},
  3063  	{V(uint(154)), V(uint(154))},
  3064  	{V(uint(155)), V(uintptr(155))},
  3065  	{V(uintptr(156)), V(uint(156))},
  3066  	{V(uint(157)), V(float32(157))},
  3067  	{V(float32(158)), V(uint(158))},
  3068  	{V(uint(159)), V(float64(159))},
  3069  	{V(float64(160)), V(uint(160))},
  3070  	{V(uintptr(161)), V(uintptr(161))},
  3071  	{V(uintptr(162)), V(float32(162))},
  3072  	{V(float32(163)), V(uintptr(163))},
  3073  	{V(uintptr(164)), V(float64(164))},
  3074  	{V(float64(165)), V(uintptr(165))},
  3075  	{V(float32(166)), V(float32(166))},
  3076  	{V(float32(167)), V(float64(167))},
  3077  	{V(float64(168)), V(float32(168))},
  3078  	{V(float64(169)), V(float64(169))},
  3079  
  3080  	// truncation
  3081  	{V(float64(1.5)), V(int(1))},
  3082  
  3083  	// complex
  3084  	{V(complex64(1i)), V(complex64(1i))},
  3085  	{V(complex64(2i)), V(complex128(2i))},
  3086  	{V(complex128(3i)), V(complex64(3i))},
  3087  	{V(complex128(4i)), V(complex128(4i))},
  3088  
  3089  	// string
  3090  	{V(string("hello")), V(string("hello"))},
  3091  	{V(string("bytes1")), V([]byte("bytes1"))},
  3092  	{V([]byte("bytes2")), V(string("bytes2"))},
  3093  	{V([]byte("bytes3")), V([]byte("bytes3"))},
  3094  	{V(string("runes♝")), V([]rune("runes♝"))},
  3095  	{V([]rune("runes♕")), V(string("runes♕"))},
  3096  	{V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  3097  	{V(int('a')), V(string("a"))},
  3098  	{V(int8('a')), V(string("a"))},
  3099  	{V(int16('a')), V(string("a"))},
  3100  	{V(int32('a')), V(string("a"))},
  3101  	{V(int64('a')), V(string("a"))},
  3102  	{V(uint('a')), V(string("a"))},
  3103  	{V(uint8('a')), V(string("a"))},
  3104  	{V(uint16('a')), V(string("a"))},
  3105  	{V(uint32('a')), V(string("a"))},
  3106  	{V(uint64('a')), V(string("a"))},
  3107  	{V(uintptr('a')), V(string("a"))},
  3108  	{V(int(-1)), V(string("\uFFFD"))},
  3109  	{V(int8(-2)), V(string("\uFFFD"))},
  3110  	{V(int16(-3)), V(string("\uFFFD"))},
  3111  	{V(int32(-4)), V(string("\uFFFD"))},
  3112  	{V(int64(-5)), V(string("\uFFFD"))},
  3113  	{V(uint(0x110001)), V(string("\uFFFD"))},
  3114  	{V(uint32(0x110002)), V(string("\uFFFD"))},
  3115  	{V(uint64(0x110003)), V(string("\uFFFD"))},
  3116  	{V(uintptr(0x110004)), V(string("\uFFFD"))},
  3117  
  3118  	// named string
  3119  	{V(MyString("hello")), V(string("hello"))},
  3120  	{V(string("hello")), V(MyString("hello"))},
  3121  	{V(string("hello")), V(string("hello"))},
  3122  	{V(MyString("hello")), V(MyString("hello"))},
  3123  	{V(MyString("bytes1")), V([]byte("bytes1"))},
  3124  	{V([]byte("bytes2")), V(MyString("bytes2"))},
  3125  	{V([]byte("bytes3")), V([]byte("bytes3"))},
  3126  	{V(MyString("runes♝")), V([]rune("runes♝"))},
  3127  	{V([]rune("runes♕")), V(MyString("runes♕"))},
  3128  	{V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  3129  	{V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
  3130  	{V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))},
  3131  	{V(int('a')), V(MyString("a"))},
  3132  	{V(int8('a')), V(MyString("a"))},
  3133  	{V(int16('a')), V(MyString("a"))},
  3134  	{V(int32('a')), V(MyString("a"))},
  3135  	{V(int64('a')), V(MyString("a"))},
  3136  	{V(uint('a')), V(MyString("a"))},
  3137  	{V(uint8('a')), V(MyString("a"))},
  3138  	{V(uint16('a')), V(MyString("a"))},
  3139  	{V(uint32('a')), V(MyString("a"))},
  3140  	{V(uint64('a')), V(MyString("a"))},
  3141  	{V(uintptr('a')), V(MyString("a"))},
  3142  	{V(int(-1)), V(MyString("\uFFFD"))},
  3143  	{V(int8(-2)), V(MyString("\uFFFD"))},
  3144  	{V(int16(-3)), V(MyString("\uFFFD"))},
  3145  	{V(int32(-4)), V(MyString("\uFFFD"))},
  3146  	{V(int64(-5)), V(MyString("\uFFFD"))},
  3147  	{V(uint(0x110001)), V(MyString("\uFFFD"))},
  3148  	{V(uint32(0x110002)), V(MyString("\uFFFD"))},
  3149  	{V(uint64(0x110003)), V(MyString("\uFFFD"))},
  3150  	{V(uintptr(0x110004)), V(MyString("\uFFFD"))},
  3151  
  3152  	// named []byte
  3153  	{V(string("bytes1")), V(MyBytes("bytes1"))},
  3154  	{V(MyBytes("bytes2")), V(string("bytes2"))},
  3155  	{V(MyBytes("bytes3")), V(MyBytes("bytes3"))},
  3156  	{V(MyString("bytes1")), V(MyBytes("bytes1"))},
  3157  	{V(MyBytes("bytes2")), V(MyString("bytes2"))},
  3158  
  3159  	// named []rune
  3160  	{V(string("runes♝")), V(MyRunes("runes♝"))},
  3161  	{V(MyRunes("runes♕")), V(string("runes♕"))},
  3162  	{V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))},
  3163  	{V(MyString("runes♝")), V(MyRunes("runes♝"))},
  3164  	{V(MyRunes("runes♕")), V(MyString("runes♕"))},
  3165  
  3166  	// named types and equal underlying types
  3167  	{V(new(int)), V(new(integer))},
  3168  	{V(new(integer)), V(new(int))},
  3169  	{V(Empty{}), V(struct{}{})},
  3170  	{V(new(Empty)), V(new(struct{}))},
  3171  	{V(struct{}{}), V(Empty{})},
  3172  	{V(new(struct{})), V(new(Empty))},
  3173  	{V(Empty{}), V(Empty{})},
  3174  	{V(MyBytes{}), V([]byte{})},
  3175  	{V([]byte{}), V(MyBytes{})},
  3176  	{V((func())(nil)), V(MyFunc(nil))},
  3177  	{V((MyFunc)(nil)), V((func())(nil))},
  3178  
  3179  	// can convert *byte and *MyByte
  3180  	{V((*byte)(nil)), V((*MyByte)(nil))},
  3181  	{V((*MyByte)(nil)), V((*byte)(nil))},
  3182  
  3183  	// cannot convert mismatched array sizes
  3184  	{V([2]byte{}), V([2]byte{})},
  3185  	{V([3]byte{}), V([3]byte{})},
  3186  
  3187  	// cannot convert other instances
  3188  	{V((**byte)(nil)), V((**byte)(nil))},
  3189  	{V((**MyByte)(nil)), V((**MyByte)(nil))},
  3190  	{V((chan byte)(nil)), V((chan byte)(nil))},
  3191  	{V((chan MyByte)(nil)), V((chan MyByte)(nil))},
  3192  	{V(([]byte)(nil)), V(([]byte)(nil))},
  3193  	{V(([]MyByte)(nil)), V(([]MyByte)(nil))},
  3194  	{V((map[int]byte)(nil)), V((map[int]byte)(nil))},
  3195  	{V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))},
  3196  	{V((map[byte]int)(nil)), V((map[byte]int)(nil))},
  3197  	{V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))},
  3198  	{V([2]byte{}), V([2]byte{})},
  3199  	{V([2]MyByte{}), V([2]MyByte{})},
  3200  
  3201  	// other
  3202  	{V((***int)(nil)), V((***int)(nil))},
  3203  	{V((***byte)(nil)), V((***byte)(nil))},
  3204  	{V((***int32)(nil)), V((***int32)(nil))},
  3205  	{V((***int64)(nil)), V((***int64)(nil))},
  3206  	{V((chan int)(nil)), V((<-chan int)(nil))},
  3207  	{V((chan int)(nil)), V((chan<- int)(nil))},
  3208  	{V((chan string)(nil)), V((<-chan string)(nil))},
  3209  	{V((chan string)(nil)), V((chan<- string)(nil))},
  3210  	{V((chan byte)(nil)), V((chan byte)(nil))},
  3211  	{V((chan MyByte)(nil)), V((chan MyByte)(nil))},
  3212  	{V((map[int]bool)(nil)), V((map[int]bool)(nil))},
  3213  	{V((map[int]byte)(nil)), V((map[int]byte)(nil))},
  3214  	{V((map[uint]bool)(nil)), V((map[uint]bool)(nil))},
  3215  	{V([]uint(nil)), V([]uint(nil))},
  3216  	{V([]int(nil)), V([]int(nil))},
  3217  	{V(new(interface{})), V(new(interface{}))},
  3218  	{V(new(io.Reader)), V(new(io.Reader))},
  3219  	{V(new(io.Writer)), V(new(io.Writer))},
  3220  
  3221  	// interfaces
  3222  	{V(int(1)), EmptyInterfaceV(int(1))},
  3223  	{V(string("hello")), EmptyInterfaceV(string("hello"))},
  3224  	{V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
  3225  	{ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))},
  3226  	{V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))},
  3227  }
  3228  
  3229  func TestConvert(t *testing.T) {
  3230  	canConvert := map[[2]Type]bool{}
  3231  	all := map[Type]bool{}
  3232  
  3233  	for _, tt := range convertTests {
  3234  		t1 := tt.in.Type()
  3235  		if !t1.ConvertibleTo(t1) {
  3236  			t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1)
  3237  			continue
  3238  		}
  3239  
  3240  		t2 := tt.out.Type()
  3241  		if !t1.ConvertibleTo(t2) {
  3242  			t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2)
  3243  			continue
  3244  		}
  3245  
  3246  		all[t1] = true
  3247  		all[t2] = true
  3248  		canConvert[[2]Type{t1, t2}] = true
  3249  
  3250  		// vout1 represents the in value converted to the in type.
  3251  		v1 := tt.in
  3252  		vout1 := v1.Convert(t1)
  3253  		out1 := vout1.Interface()
  3254  		if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) {
  3255  			t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t1, out1, tt.in.Interface())
  3256  		}
  3257  
  3258  		// vout2 represents the in value converted to the out type.
  3259  		vout2 := v1.Convert(t2)
  3260  		out2 := vout2.Interface()
  3261  		if vout2.Type() != tt.out.Type() || !DeepEqual(out2, tt.out.Interface()) {
  3262  			t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out2, tt.out.Interface())
  3263  		}
  3264  
  3265  		// vout3 represents a new value of the out type, set to vout2.  This makes
  3266  		// sure the converted value vout2 is really usable as a regular value.
  3267  		vout3 := New(t2).Elem()
  3268  		vout3.Set(vout2)
  3269  		out3 := vout3.Interface()
  3270  		if vout3.Type() != tt.out.Type() || !DeepEqual(out3, tt.out.Interface()) {
  3271  			t.Errorf("Set(ValueOf(%T(%[1]v)).Convert(%s)) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out3, tt.out.Interface())
  3272  		}
  3273  
  3274  		if IsRO(v1) {
  3275  			t.Errorf("table entry %v is RO, should not be", v1)
  3276  		}
  3277  		if IsRO(vout1) {
  3278  			t.Errorf("self-conversion output %v is RO, should not be", vout1)
  3279  		}
  3280  		if IsRO(vout2) {
  3281  			t.Errorf("conversion output %v is RO, should not be", vout2)
  3282  		}
  3283  		if IsRO(vout3) {
  3284  			t.Errorf("set(conversion output) %v is RO, should not be", vout3)
  3285  		}
  3286  		if !IsRO(MakeRO(v1).Convert(t1)) {
  3287  			t.Errorf("RO self-conversion output %v is not RO, should be", v1)
  3288  		}
  3289  		if !IsRO(MakeRO(v1).Convert(t2)) {
  3290  			t.Errorf("RO conversion output %v is not RO, should be", v1)
  3291  		}
  3292  	}
  3293  
  3294  	// Assume that of all the types we saw during the tests,
  3295  	// if there wasn't an explicit entry for a conversion between
  3296  	// a pair of types, then it's not to be allowed. This checks for
  3297  	// things like 'int64' converting to '*int'.
  3298  	for t1 := range all {
  3299  		for t2 := range all {
  3300  			expectOK := t1 == t2 || canConvert[[2]Type{t1, t2}] || t2.Kind() == Interface && t2.NumMethod() == 0
  3301  			if ok := t1.ConvertibleTo(t2); ok != expectOK {
  3302  				t.Errorf("(%s).ConvertibleTo(%s) = %v, want %v", t1, t2, ok, expectOK)
  3303  			}
  3304  		}
  3305  	}
  3306  }
  3307  
  3308  type ComparableStruct struct {
  3309  	X int
  3310  }
  3311  
  3312  type NonComparableStruct struct {
  3313  	X int
  3314  	Y map[string]int
  3315  }
  3316  
  3317  var comparableTests = []struct {
  3318  	typ Type
  3319  	ok  bool
  3320  }{
  3321  	{TypeOf(1), true},
  3322  	{TypeOf("hello"), true},
  3323  	{TypeOf(new(byte)), true},
  3324  	{TypeOf((func())(nil)), false},
  3325  	{TypeOf([]byte{}), false},
  3326  	{TypeOf(map[string]int{}), false},
  3327  	{TypeOf(make(chan int)), true},
  3328  	{TypeOf(1.5), true},
  3329  	{TypeOf(false), true},
  3330  	{TypeOf(1i), true},
  3331  	{TypeOf(ComparableStruct{}), true},
  3332  	{TypeOf(NonComparableStruct{}), false},
  3333  	{TypeOf([10]map[string]int{}), false},
  3334  	{TypeOf([10]string{}), true},
  3335  	{TypeOf(new(interface{})).Elem(), true},
  3336  }
  3337  
  3338  func TestComparable(t *testing.T) {
  3339  	for _, tt := range comparableTests {
  3340  		if ok := tt.typ.Comparable(); ok != tt.ok {
  3341  			t.Errorf("TypeOf(%v).Comparable() = %v, want %v", tt.typ, ok, tt.ok)
  3342  		}
  3343  	}
  3344  }
  3345  
  3346  func TestOverflow(t *testing.T) {
  3347  	if ovf := V(float64(0)).OverflowFloat(1e300); ovf {
  3348  		t.Errorf("%v wrongly overflows float64", 1e300)
  3349  	}
  3350  
  3351  	maxFloat32 := float64((1<<24 - 1) << (127 - 23))
  3352  	if ovf := V(float32(0)).OverflowFloat(maxFloat32); ovf {
  3353  		t.Errorf("%v wrongly overflows float32", maxFloat32)
  3354  	}
  3355  	ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52))
  3356  	if ovf := V(float32(0)).OverflowFloat(ovfFloat32); !ovf {
  3357  		t.Errorf("%v should overflow float32", ovfFloat32)
  3358  	}
  3359  	if ovf := V(float32(0)).OverflowFloat(-ovfFloat32); !ovf {
  3360  		t.Errorf("%v should overflow float32", -ovfFloat32)
  3361  	}
  3362  
  3363  	maxInt32 := int64(0x7fffffff)
  3364  	if ovf := V(int32(0)).OverflowInt(maxInt32); ovf {
  3365  		t.Errorf("%v wrongly overflows int32", maxInt32)
  3366  	}
  3367  	if ovf := V(int32(0)).OverflowInt(-1 << 31); ovf {
  3368  		t.Errorf("%v wrongly overflows int32", -int64(1)<<31)
  3369  	}
  3370  	ovfInt32 := int64(1 << 31)
  3371  	if ovf := V(int32(0)).OverflowInt(ovfInt32); !ovf {
  3372  		t.Errorf("%v should overflow int32", ovfInt32)
  3373  	}
  3374  
  3375  	maxUint32 := uint64(0xffffffff)
  3376  	if ovf := V(uint32(0)).OverflowUint(maxUint32); ovf {
  3377  		t.Errorf("%v wrongly overflows uint32", maxUint32)
  3378  	}
  3379  	ovfUint32 := uint64(1 << 32)
  3380  	if ovf := V(uint32(0)).OverflowUint(ovfUint32); !ovf {
  3381  		t.Errorf("%v should overflow uint32", ovfUint32)
  3382  	}
  3383  }
  3384  
  3385  func checkSameType(t *testing.T, x, y interface{}) {
  3386  	if TypeOf(x) != TypeOf(y) {
  3387  		t.Errorf("did not find preexisting type for %s (vs %s)", TypeOf(x), TypeOf(y))
  3388  	}
  3389  }
  3390  
  3391  func TestArrayOf(t *testing.T) {
  3392  	// check construction and use of type not in binary
  3393  	for _, table := range []struct {
  3394  		n          int
  3395  		value      func(i int) interface{}
  3396  		comparable bool
  3397  		want       string
  3398  	}{
  3399  		{
  3400  			n:          0,
  3401  			value:      func(i int) interface{} { type Tint int; return Tint(i) },
  3402  			comparable: true,
  3403  			want:       "[]",
  3404  		},
  3405  		{
  3406  			n:          10,
  3407  			value:      func(i int) interface{} { type Tint int; return Tint(i) },
  3408  			comparable: true,
  3409  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  3410  		},
  3411  		{
  3412  			n:          10,
  3413  			value:      func(i int) interface{} { type Tfloat float64; return Tfloat(i) },
  3414  			comparable: true,
  3415  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  3416  		},
  3417  		{
  3418  			n:          10,
  3419  			value:      func(i int) interface{} { type Tstring string; return Tstring(strconv.Itoa(i)) },
  3420  			comparable: true,
  3421  			want:       "[0 1 2 3 4 5 6 7 8 9]",
  3422  		},
  3423  		{
  3424  			n:          10,
  3425  			value:      func(i int) interface{} { type Tstruct struct{ V int }; return Tstruct{i} },
  3426  			comparable: true,
  3427  			want:       "[{0} {1} {2} {3} {4} {5} {6} {7} {8} {9}]",
  3428  		},
  3429  		{
  3430  			n:          10,
  3431  			value:      func(i int) interface{} { type Tint int; return []Tint{Tint(i)} },
  3432  			comparable: false,
  3433  			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
  3434  		},
  3435  		{
  3436  			n:          10,
  3437  			value:      func(i int) interface{} { type Tint int; return [1]Tint{Tint(i)} },
  3438  			comparable: true,
  3439  			want:       "[[0] [1] [2] [3] [4] [5] [6] [7] [8] [9]]",
  3440  		},
  3441  		{
  3442  			n:          10,
  3443  			value:      func(i int) interface{} { type Tstruct struct{ V [1]int }; return Tstruct{[1]int{i}} },
  3444  			comparable: true,
  3445  			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
  3446  		},
  3447  		{
  3448  			n:          10,
  3449  			value:      func(i int) interface{} { type Tstruct struct{ V []int }; return Tstruct{[]int{i}} },
  3450  			comparable: false,
  3451  			want:       "[{[0]} {[1]} {[2]} {[3]} {[4]} {[5]} {[6]} {[7]} {[8]} {[9]}]",
  3452  		},
  3453  		{
  3454  			n:          10,
  3455  			value:      func(i int) interface{} { type TstructUV struct{ U, V int }; return TstructUV{i, i} },
  3456  			comparable: true,
  3457  			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
  3458  		},
  3459  		{
  3460  			n: 10,
  3461  			value: func(i int) interface{} {
  3462  				type TstructUV struct {
  3463  					U int
  3464  					V float64
  3465  				}
  3466  				return TstructUV{i, float64(i)}
  3467  			},
  3468  			comparable: true,
  3469  			want:       "[{0 0} {1 1} {2 2} {3 3} {4 4} {5 5} {6 6} {7 7} {8 8} {9 9}]",
  3470  		},
  3471  	} {
  3472  		at := ArrayOf(table.n, TypeOf(table.value(0)))
  3473  		v := New(at).Elem()
  3474  		vok := New(at).Elem()
  3475  		vnot := New(at).Elem()
  3476  		for i := 0; i < v.Len(); i++ {
  3477  			v.Index(i).Set(ValueOf(table.value(i)))
  3478  			vok.Index(i).Set(ValueOf(table.value(i)))
  3479  			j := i
  3480  			if i+1 == v.Len() {
  3481  				j = i + 1
  3482  			}
  3483  			vnot.Index(i).Set(ValueOf(table.value(j))) // make it differ only by last element
  3484  		}
  3485  		s := fmt.Sprint(v.Interface())
  3486  		if s != table.want {
  3487  			t.Errorf("constructed array = %s, want %s", s, table.want)
  3488  		}
  3489  
  3490  		if table.comparable != at.Comparable() {
  3491  			t.Errorf("constructed array (%#v) is comparable=%v, want=%v", v.Interface(), at.Comparable(), table.comparable)
  3492  		}
  3493  		if table.comparable {
  3494  			if table.n > 0 {
  3495  				if DeepEqual(vnot.Interface(), v.Interface()) {
  3496  					t.Errorf(
  3497  						"arrays (%#v) compare ok (but should not)",
  3498  						v.Interface(),
  3499  					)
  3500  				}
  3501  			}
  3502  			if !DeepEqual(vok.Interface(), v.Interface()) {
  3503  				t.Errorf(
  3504  					"arrays (%#v) compare NOT-ok (but should)",
  3505  					v.Interface(),
  3506  				)
  3507  			}
  3508  		}
  3509  	}
  3510  
  3511  	// check that type already in binary is found
  3512  	type T int
  3513  	checkSameType(t, Zero(ArrayOf(5, TypeOf(T(1)))).Interface(), [5]T{})
  3514  }
  3515  
  3516  func TestArrayOfGC(t *testing.T) {
  3517  	type T *uintptr
  3518  	tt := TypeOf(T(nil))
  3519  	const n = 100
  3520  	var x []interface{}
  3521  	for i := 0; i < n; i++ {
  3522  		v := New(ArrayOf(n, tt)).Elem()
  3523  		for j := 0; j < v.Len(); j++ {
  3524  			p := new(uintptr)
  3525  			*p = uintptr(i*n + j)
  3526  			v.Index(j).Set(ValueOf(p).Convert(tt))
  3527  		}
  3528  		x = append(x, v.Interface())
  3529  	}
  3530  	runtime.GC()
  3531  
  3532  	for i, xi := range x {
  3533  		v := ValueOf(xi)
  3534  		for j := 0; j < v.Len(); j++ {
  3535  			k := v.Index(j).Elem().Interface()
  3536  			if k != uintptr(i*n+j) {
  3537  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  3538  			}
  3539  		}
  3540  	}
  3541  }
  3542  
  3543  func TestArrayOfAlg(t *testing.T) {
  3544  	at := ArrayOf(6, TypeOf(byte(0)))
  3545  	v1 := New(at).Elem()
  3546  	v2 := New(at).Elem()
  3547  	if v1.Interface() != v1.Interface() {
  3548  		t.Errorf("constructed array %v not equal to itself", v1.Interface())
  3549  	}
  3550  	v1.Index(5).Set(ValueOf(byte(1)))
  3551  	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
  3552  		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
  3553  	}
  3554  
  3555  	at = ArrayOf(6, TypeOf([]int(nil)))
  3556  	v1 = New(at).Elem()
  3557  	shouldPanic(func() { _ = v1.Interface() == v1.Interface() })
  3558  }
  3559  
  3560  func TestArrayOfGenericAlg(t *testing.T) {
  3561  	at1 := ArrayOf(5, TypeOf(string("")))
  3562  	at := ArrayOf(6, at1)
  3563  	v1 := New(at).Elem()
  3564  	v2 := New(at).Elem()
  3565  	if v1.Interface() != v1.Interface() {
  3566  		t.Errorf("constructed array %v not equal to itself", v1.Interface())
  3567  	}
  3568  
  3569  	v1.Index(0).Index(0).Set(ValueOf("abc"))
  3570  	v2.Index(0).Index(0).Set(ValueOf("efg"))
  3571  	if i1, i2 := v1.Interface(), v2.Interface(); i1 == i2 {
  3572  		t.Errorf("constructed arrays %v and %v should not be equal", i1, i2)
  3573  	}
  3574  
  3575  	v1.Index(0).Index(0).Set(ValueOf("abc"))
  3576  	v2.Index(0).Index(0).Set(ValueOf((v1.Index(0).Index(0).String() + " ")[:3]))
  3577  	if i1, i2 := v1.Interface(), v2.Interface(); i1 != i2 {
  3578  		t.Errorf("constructed arrays %v and %v should be equal", i1, i2)
  3579  	}
  3580  
  3581  	// Test hash
  3582  	m := MakeMap(MapOf(at, TypeOf(int(0))))
  3583  	m.SetMapIndex(v1, ValueOf(1))
  3584  	if i1, i2 := v1.Interface(), v2.Interface(); !m.MapIndex(v2).IsValid() {
  3585  		t.Errorf("constructed arrays %v and %v have different hashes", i1, i2)
  3586  	}
  3587  }
  3588  
  3589  func TestArrayOfDirectIface(t *testing.T) {
  3590  	{
  3591  		type T [1]*byte
  3592  		i1 := Zero(TypeOf(T{})).Interface()
  3593  		v1 := ValueOf(&i1).Elem()
  3594  		p1 := v1.InterfaceData()[1]
  3595  
  3596  		i2 := Zero(ArrayOf(1, PtrTo(TypeOf(int8(0))))).Interface()
  3597  		v2 := ValueOf(&i2).Elem()
  3598  		p2 := v2.InterfaceData()[1]
  3599  
  3600  		if p1 != 0 {
  3601  			t.Errorf("got p1=%v. want=%v", p1, nil)
  3602  		}
  3603  
  3604  		if p2 != 0 {
  3605  			t.Errorf("got p2=%v. want=%v", p2, nil)
  3606  		}
  3607  	}
  3608  	{
  3609  		type T [0]*byte
  3610  		i1 := Zero(TypeOf(T{})).Interface()
  3611  		v1 := ValueOf(&i1).Elem()
  3612  		p1 := v1.InterfaceData()[1]
  3613  
  3614  		i2 := Zero(ArrayOf(0, PtrTo(TypeOf(int8(0))))).Interface()
  3615  		v2 := ValueOf(&i2).Elem()
  3616  		p2 := v2.InterfaceData()[1]
  3617  
  3618  		if p1 == 0 {
  3619  			t.Errorf("got p1=%v. want=not-%v", p1, nil)
  3620  		}
  3621  
  3622  		if p2 == 0 {
  3623  			t.Errorf("got p2=%v. want=not-%v", p2, nil)
  3624  		}
  3625  	}
  3626  }
  3627  
  3628  func TestSliceOf(t *testing.T) {
  3629  	// check construction and use of type not in binary
  3630  	type T int
  3631  	st := SliceOf(TypeOf(T(1)))
  3632  	v := MakeSlice(st, 10, 10)
  3633  	runtime.GC()
  3634  	for i := 0; i < v.Len(); i++ {
  3635  		v.Index(i).Set(ValueOf(T(i)))
  3636  		runtime.GC()
  3637  	}
  3638  	s := fmt.Sprint(v.Interface())
  3639  	want := "[0 1 2 3 4 5 6 7 8 9]"
  3640  	if s != want {
  3641  		t.Errorf("constructed slice = %s, want %s", s, want)
  3642  	}
  3643  
  3644  	// check that type already in binary is found
  3645  	type T1 int
  3646  	checkSameType(t, Zero(SliceOf(TypeOf(T1(1)))).Interface(), []T1{})
  3647  }
  3648  
  3649  func TestSliceOverflow(t *testing.T) {
  3650  	// check that MakeSlice panics when size of slice overflows uint
  3651  	const S = 1e6
  3652  	s := uint(S)
  3653  	l := (1<<(unsafe.Sizeof((*byte)(nil))*8)-1)/s + 1
  3654  	if l*s >= s {
  3655  		t.Fatal("slice size does not overflow")
  3656  	}
  3657  	var x [S]byte
  3658  	st := SliceOf(TypeOf(x))
  3659  	defer func() {
  3660  		err := recover()
  3661  		if err == nil {
  3662  			t.Fatal("slice overflow does not panic")
  3663  		}
  3664  	}()
  3665  	MakeSlice(st, int(l), int(l))
  3666  }
  3667  
  3668  func TestSliceOfGC(t *testing.T) {
  3669  	type T *uintptr
  3670  	tt := TypeOf(T(nil))
  3671  	st := SliceOf(tt)
  3672  	const n = 100
  3673  	var x []interface{}
  3674  	for i := 0; i < n; i++ {
  3675  		v := MakeSlice(st, n, n)
  3676  		for j := 0; j < v.Len(); j++ {
  3677  			p := new(uintptr)
  3678  			*p = uintptr(i*n + j)
  3679  			v.Index(j).Set(ValueOf(p).Convert(tt))
  3680  		}
  3681  		x = append(x, v.Interface())
  3682  	}
  3683  	runtime.GC()
  3684  
  3685  	for i, xi := range x {
  3686  		v := ValueOf(xi)
  3687  		for j := 0; j < v.Len(); j++ {
  3688  			k := v.Index(j).Elem().Interface()
  3689  			if k != uintptr(i*n+j) {
  3690  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  3691  			}
  3692  		}
  3693  	}
  3694  }
  3695  
  3696  func TestChanOf(t *testing.T) {
  3697  	// check construction and use of type not in binary
  3698  	type T string
  3699  	ct := ChanOf(BothDir, TypeOf(T("")))
  3700  	v := MakeChan(ct, 2)
  3701  	runtime.GC()
  3702  	v.Send(ValueOf(T("hello")))
  3703  	runtime.GC()
  3704  	v.Send(ValueOf(T("world")))
  3705  	runtime.GC()
  3706  
  3707  	sv1, _ := v.Recv()
  3708  	sv2, _ := v.Recv()
  3709  	s1 := sv1.String()
  3710  	s2 := sv2.String()
  3711  	if s1 != "hello" || s2 != "world" {
  3712  		t.Errorf("constructed chan: have %q, %q, want %q, %q", s1, s2, "hello", "world")
  3713  	}
  3714  
  3715  	// check that type already in binary is found
  3716  	type T1 int
  3717  	checkSameType(t, Zero(ChanOf(BothDir, TypeOf(T1(1)))).Interface(), (chan T1)(nil))
  3718  }
  3719  
  3720  func TestChanOfDir(t *testing.T) {
  3721  	// check construction and use of type not in binary
  3722  	type T string
  3723  	crt := ChanOf(RecvDir, TypeOf(T("")))
  3724  	cst := ChanOf(SendDir, TypeOf(T("")))
  3725  
  3726  	// check that type already in binary is found
  3727  	type T1 int
  3728  	checkSameType(t, Zero(ChanOf(RecvDir, TypeOf(T1(1)))).Interface(), (<-chan T1)(nil))
  3729  	checkSameType(t, Zero(ChanOf(SendDir, TypeOf(T1(1)))).Interface(), (chan<- T1)(nil))
  3730  
  3731  	// check String form of ChanDir
  3732  	if crt.ChanDir().String() != "<-chan" {
  3733  		t.Errorf("chan dir: have %q, want %q", crt.ChanDir().String(), "<-chan")
  3734  	}
  3735  	if cst.ChanDir().String() != "chan<-" {
  3736  		t.Errorf("chan dir: have %q, want %q", cst.ChanDir().String(), "chan<-")
  3737  	}
  3738  }
  3739  
  3740  func TestChanOfGC(t *testing.T) {
  3741  	done := make(chan bool, 1)
  3742  	go func() {
  3743  		select {
  3744  		case <-done:
  3745  		case <-time.After(5 * time.Second):
  3746  			panic("deadlock in TestChanOfGC")
  3747  		}
  3748  	}()
  3749  
  3750  	defer func() {
  3751  		done <- true
  3752  	}()
  3753  
  3754  	type T *uintptr
  3755  	tt := TypeOf(T(nil))
  3756  	ct := ChanOf(BothDir, tt)
  3757  
  3758  	// NOTE: The garbage collector handles allocated channels specially,
  3759  	// so we have to save pointers to channels in x; the pointer code will
  3760  	// use the gc info in the newly constructed chan type.
  3761  	const n = 100
  3762  	var x []interface{}
  3763  	for i := 0; i < n; i++ {
  3764  		v := MakeChan(ct, n)
  3765  		for j := 0; j < n; j++ {
  3766  			p := new(uintptr)
  3767  			*p = uintptr(i*n + j)
  3768  			v.Send(ValueOf(p).Convert(tt))
  3769  		}
  3770  		pv := New(ct)
  3771  		pv.Elem().Set(v)
  3772  		x = append(x, pv.Interface())
  3773  	}
  3774  	runtime.GC()
  3775  
  3776  	for i, xi := range x {
  3777  		v := ValueOf(xi).Elem()
  3778  		for j := 0; j < n; j++ {
  3779  			pv, _ := v.Recv()
  3780  			k := pv.Elem().Interface()
  3781  			if k != uintptr(i*n+j) {
  3782  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  3783  			}
  3784  		}
  3785  	}
  3786  }
  3787  
  3788  func TestMapOf(t *testing.T) {
  3789  	// check construction and use of type not in binary
  3790  	type K string
  3791  	type V float64
  3792  
  3793  	v := MakeMap(MapOf(TypeOf(K("")), TypeOf(V(0))))
  3794  	runtime.GC()
  3795  	v.SetMapIndex(ValueOf(K("a")), ValueOf(V(1)))
  3796  	runtime.GC()
  3797  
  3798  	s := fmt.Sprint(v.Interface())
  3799  	want := "map[a:1]"
  3800  	if s != want {
  3801  		t.Errorf("constructed map = %s, want %s", s, want)
  3802  	}
  3803  
  3804  	// check that type already in binary is found
  3805  	checkSameType(t, Zero(MapOf(TypeOf(V(0)), TypeOf(K("")))).Interface(), map[V]K(nil))
  3806  
  3807  	// check that invalid key type panics
  3808  	shouldPanic(func() { MapOf(TypeOf((func())(nil)), TypeOf(false)) })
  3809  }
  3810  
  3811  func TestMapOfGCKeys(t *testing.T) {
  3812  	type T *uintptr
  3813  	tt := TypeOf(T(nil))
  3814  	mt := MapOf(tt, TypeOf(false))
  3815  
  3816  	// NOTE: The garbage collector handles allocated maps specially,
  3817  	// so we have to save pointers to maps in x; the pointer code will
  3818  	// use the gc info in the newly constructed map type.
  3819  	const n = 100
  3820  	var x []interface{}
  3821  	for i := 0; i < n; i++ {
  3822  		v := MakeMap(mt)
  3823  		for j := 0; j < n; j++ {
  3824  			p := new(uintptr)
  3825  			*p = uintptr(i*n + j)
  3826  			v.SetMapIndex(ValueOf(p).Convert(tt), ValueOf(true))
  3827  		}
  3828  		pv := New(mt)
  3829  		pv.Elem().Set(v)
  3830  		x = append(x, pv.Interface())
  3831  	}
  3832  	runtime.GC()
  3833  
  3834  	for i, xi := range x {
  3835  		v := ValueOf(xi).Elem()
  3836  		var out []int
  3837  		for _, kv := range v.MapKeys() {
  3838  			out = append(out, int(kv.Elem().Interface().(uintptr)))
  3839  		}
  3840  		sort.Ints(out)
  3841  		for j, k := range out {
  3842  			if k != i*n+j {
  3843  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  3844  			}
  3845  		}
  3846  	}
  3847  }
  3848  
  3849  func TestMapOfGCValues(t *testing.T) {
  3850  	type T *uintptr
  3851  	tt := TypeOf(T(nil))
  3852  	mt := MapOf(TypeOf(1), tt)
  3853  
  3854  	// NOTE: The garbage collector handles allocated maps specially,
  3855  	// so we have to save pointers to maps in x; the pointer code will
  3856  	// use the gc info in the newly constructed map type.
  3857  	const n = 100
  3858  	var x []interface{}
  3859  	for i := 0; i < n; i++ {
  3860  		v := MakeMap(mt)
  3861  		for j := 0; j < n; j++ {
  3862  			p := new(uintptr)
  3863  			*p = uintptr(i*n + j)
  3864  			v.SetMapIndex(ValueOf(j), ValueOf(p).Convert(tt))
  3865  		}
  3866  		pv := New(mt)
  3867  		pv.Elem().Set(v)
  3868  		x = append(x, pv.Interface())
  3869  	}
  3870  	runtime.GC()
  3871  
  3872  	for i, xi := range x {
  3873  		v := ValueOf(xi).Elem()
  3874  		for j := 0; j < n; j++ {
  3875  			k := v.MapIndex(ValueOf(j)).Elem().Interface().(uintptr)
  3876  			if k != uintptr(i*n+j) {
  3877  				t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j)
  3878  			}
  3879  		}
  3880  	}
  3881  }
  3882  
  3883  func TestTypelinksSorted(t *testing.T) {
  3884  	var last string
  3885  	for i, n := range TypeLinks() {
  3886  		if n < last {
  3887  			t.Errorf("typelinks not sorted: %q [%d] > %q [%d]", last, i-1, n, i)
  3888  		}
  3889  		last = n
  3890  	}
  3891  }
  3892  
  3893  func TestFuncOf(t *testing.T) {
  3894  	// check construction and use of type not in binary
  3895  	type K string
  3896  	type V float64
  3897  
  3898  	fn := func(args []Value) []Value {
  3899  		if len(args) != 1 {
  3900  			t.Errorf("args == %v, want exactly one arg", args)
  3901  		} else if args[0].Type() != TypeOf(K("")) {
  3902  			t.Errorf("args[0] is type %v, want %v", args[0].Type, TypeOf(K("")))
  3903  		} else if args[0].String() != "gopher" {
  3904  			t.Errorf("args[0] = %q, want %q", args[0].String(), "gopher")
  3905  		}
  3906  		return []Value{ValueOf(V(3.14))}
  3907  	}
  3908  	v := MakeFunc(FuncOf([]Type{TypeOf(K(""))}, []Type{TypeOf(V(0))}, false), fn)
  3909  
  3910  	outs := v.Call([]Value{ValueOf(K("gopher"))})
  3911  	if len(outs) != 1 {
  3912  		t.Fatalf("v.Call returned %v, want exactly one result", outs)
  3913  	} else if outs[0].Type() != TypeOf(V(0)) {
  3914  		t.Fatalf("c.Call[0] is type %v, want %v", outs[0].Type, TypeOf(V(0)))
  3915  	}
  3916  	f := outs[0].Float()
  3917  	if f != 3.14 {
  3918  		t.Errorf("constructed func returned %f, want %f", f, 3.14)
  3919  	}
  3920  
  3921  	// check that types already in binary are found
  3922  	type T1 int
  3923  	testCases := []struct {
  3924  		in, out  []Type
  3925  		variadic bool
  3926  		want     interface{}
  3927  	}{
  3928  		{in: []Type{TypeOf(T1(0))}, want: (func(T1))(nil)},
  3929  		{in: []Type{TypeOf(int(0))}, want: (func(int))(nil)},
  3930  		{in: []Type{SliceOf(TypeOf(int(0)))}, variadic: true, want: (func(...int))(nil)},
  3931  		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false)}, want: (func(int) bool)(nil)},
  3932  		{in: []Type{TypeOf(int(0))}, out: []Type{TypeOf(false), TypeOf("")}, want: (func(int) (bool, string))(nil)},
  3933  	}
  3934  	for _, tt := range testCases {
  3935  		checkSameType(t, Zero(FuncOf(tt.in, tt.out, tt.variadic)).Interface(), tt.want)
  3936  	}
  3937  
  3938  	// check that variadic requires last element be a slice.
  3939  	FuncOf([]Type{TypeOf(1), TypeOf(""), SliceOf(TypeOf(false))}, nil, true)
  3940  	shouldPanic(func() { FuncOf([]Type{TypeOf(0), TypeOf(""), TypeOf(false)}, nil, true) })
  3941  	shouldPanic(func() { FuncOf(nil, nil, true) })
  3942  }
  3943  
  3944  type B1 struct {
  3945  	X int
  3946  	Y int
  3947  	Z int
  3948  }
  3949  
  3950  func BenchmarkFieldByName1(b *testing.B) {
  3951  	t := TypeOf(B1{})
  3952  	for i := 0; i < b.N; i++ {
  3953  		t.FieldByName("Z")
  3954  	}
  3955  }
  3956  
  3957  func BenchmarkFieldByName2(b *testing.B) {
  3958  	t := TypeOf(S3{})
  3959  	for i := 0; i < b.N; i++ {
  3960  		t.FieldByName("B")
  3961  	}
  3962  }
  3963  
  3964  type R0 struct {
  3965  	*R1
  3966  	*R2
  3967  	*R3
  3968  	*R4
  3969  }
  3970  
  3971  type R1 struct {
  3972  	*R5
  3973  	*R6
  3974  	*R7
  3975  	*R8
  3976  }
  3977  
  3978  type R2 R1
  3979  type R3 R1
  3980  type R4 R1
  3981  
  3982  type R5 struct {
  3983  	*R9
  3984  	*R10
  3985  	*R11
  3986  	*R12
  3987  }
  3988  
  3989  type R6 R5
  3990  type R7 R5
  3991  type R8 R5
  3992  
  3993  type R9 struct {
  3994  	*R13
  3995  	*R14
  3996  	*R15
  3997  	*R16
  3998  }
  3999  
  4000  type R10 R9
  4001  type R11 R9
  4002  type R12 R9
  4003  
  4004  type R13 struct {
  4005  	*R17
  4006  	*R18
  4007  	*R19
  4008  	*R20
  4009  }
  4010  
  4011  type R14 R13
  4012  type R15 R13
  4013  type R16 R13
  4014  
  4015  type R17 struct {
  4016  	*R21
  4017  	*R22
  4018  	*R23
  4019  	*R24
  4020  }
  4021  
  4022  type R18 R17
  4023  type R19 R17
  4024  type R20 R17
  4025  
  4026  type R21 struct {
  4027  	X int
  4028  }
  4029  
  4030  type R22 R21
  4031  type R23 R21
  4032  type R24 R21
  4033  
  4034  func TestEmbed(t *testing.T) {
  4035  	typ := TypeOf(R0{})
  4036  	f, ok := typ.FieldByName("X")
  4037  	if ok {
  4038  		t.Fatalf(`FieldByName("X") should fail, returned %v`, f.Index)
  4039  	}
  4040  }
  4041  
  4042  func BenchmarkFieldByName3(b *testing.B) {
  4043  	t := TypeOf(R0{})
  4044  	for i := 0; i < b.N; i++ {
  4045  		t.FieldByName("X")
  4046  	}
  4047  }
  4048  
  4049  type S struct {
  4050  	i1 int64
  4051  	i2 int64
  4052  }
  4053  
  4054  func BenchmarkInterfaceBig(b *testing.B) {
  4055  	v := ValueOf(S{})
  4056  	for i := 0; i < b.N; i++ {
  4057  		v.Interface()
  4058  	}
  4059  	b.StopTimer()
  4060  }
  4061  
  4062  func TestAllocsInterfaceBig(t *testing.T) {
  4063  	if testing.Short() {
  4064  		t.Skip("skipping malloc count in short mode")
  4065  	}
  4066  	v := ValueOf(S{})
  4067  	if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
  4068  		t.Error("allocs:", allocs)
  4069  	}
  4070  }
  4071  
  4072  func BenchmarkInterfaceSmall(b *testing.B) {
  4073  	v := ValueOf(int64(0))
  4074  	for i := 0; i < b.N; i++ {
  4075  		v.Interface()
  4076  	}
  4077  }
  4078  
  4079  func TestAllocsInterfaceSmall(t *testing.T) {
  4080  	if testing.Short() {
  4081  		t.Skip("skipping malloc count in short mode")
  4082  	}
  4083  	v := ValueOf(int64(0))
  4084  	if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 {
  4085  		t.Error("allocs:", allocs)
  4086  	}
  4087  }
  4088  
  4089  // An exhaustive is a mechanism for writing exhaustive or stochastic tests.
  4090  // The basic usage is:
  4091  //
  4092  //	for x.Next() {
  4093  //		... code using x.Maybe() or x.Choice(n) to create test cases ...
  4094  //	}
  4095  //
  4096  // Each iteration of the loop returns a different set of results, until all
  4097  // possible result sets have been explored. It is okay for different code paths
  4098  // to make different method call sequences on x, but there must be no
  4099  // other source of non-determinism in the call sequences.
  4100  //
  4101  // When faced with a new decision, x chooses randomly. Future explorations
  4102  // of that path will choose successive values for the result. Thus, stopping
  4103  // the loop after a fixed number of iterations gives somewhat stochastic
  4104  // testing.
  4105  //
  4106  // Example:
  4107  //
  4108  //	for x.Next() {
  4109  //		v := make([]bool, x.Choose(4))
  4110  //		for i := range v {
  4111  //			v[i] = x.Maybe()
  4112  //		}
  4113  //		fmt.Println(v)
  4114  //	}
  4115  //
  4116  // prints (in some order):
  4117  //
  4118  //	[]
  4119  //	[false]
  4120  //	[true]
  4121  //	[false false]
  4122  //	[false true]
  4123  //	...
  4124  //	[true true]
  4125  //	[false false false]
  4126  //	...
  4127  //	[true true true]
  4128  //	[false false false false]
  4129  //	...
  4130  //	[true true true true]
  4131  //
  4132  type exhaustive struct {
  4133  	r    *rand.Rand
  4134  	pos  int
  4135  	last []choice
  4136  }
  4137  
  4138  type choice struct {
  4139  	off int
  4140  	n   int
  4141  	max int
  4142  }
  4143  
  4144  func (x *exhaustive) Next() bool {
  4145  	if x.r == nil {
  4146  		x.r = rand.New(rand.NewSource(time.Now().UnixNano()))
  4147  	}
  4148  	x.pos = 0
  4149  	if x.last == nil {
  4150  		x.last = []choice{}
  4151  		return true
  4152  	}
  4153  	for i := len(x.last) - 1; i >= 0; i-- {
  4154  		c := &x.last[i]
  4155  		if c.n+1 < c.max {
  4156  			c.n++
  4157  			x.last = x.last[:i+1]
  4158  			return true
  4159  		}
  4160  	}
  4161  	return false
  4162  }
  4163  
  4164  func (x *exhaustive) Choose(max int) int {
  4165  	if x.pos >= len(x.last) {
  4166  		x.last = append(x.last, choice{x.r.Intn(max), 0, max})
  4167  	}
  4168  	c := &x.last[x.pos]
  4169  	x.pos++
  4170  	if c.max != max {
  4171  		panic("inconsistent use of exhaustive tester")
  4172  	}
  4173  	return (c.n + c.off) % max
  4174  }
  4175  
  4176  func (x *exhaustive) Maybe() bool {
  4177  	return x.Choose(2) == 1
  4178  }
  4179  
  4180  func GCFunc(args []Value) []Value {
  4181  	runtime.GC()
  4182  	return []Value{}
  4183  }
  4184  
  4185  func TestReflectFuncTraceback(t *testing.T) {
  4186  	f := MakeFunc(TypeOf(func() {}), GCFunc)
  4187  	f.Call([]Value{})
  4188  }
  4189  
  4190  func TestReflectMethodTraceback(t *testing.T) {
  4191  	p := Point{3, 4}
  4192  	m := ValueOf(p).MethodByName("GCMethod")
  4193  	i := ValueOf(m.Interface()).Call([]Value{ValueOf(5)})[0].Int()
  4194  	if i != 8 {
  4195  		t.Errorf("Call returned %d; want 8", i)
  4196  	}
  4197  }
  4198  
  4199  func TestBigZero(t *testing.T) {
  4200  	const size = 1 << 10
  4201  	var v [size]byte
  4202  	z := Zero(ValueOf(v).Type()).Interface().([size]byte)
  4203  	for i := 0; i < size; i++ {
  4204  		if z[i] != 0 {
  4205  			t.Fatalf("Zero object not all zero, index %d", i)
  4206  		}
  4207  	}
  4208  }
  4209  
  4210  func TestFieldByIndexNil(t *testing.T) {
  4211  	type P struct {
  4212  		F int
  4213  	}
  4214  	type T struct {
  4215  		*P
  4216  	}
  4217  	v := ValueOf(T{})
  4218  
  4219  	v.FieldByName("P") // should be fine
  4220  
  4221  	defer func() {
  4222  		if err := recover(); err == nil {
  4223  			t.Fatalf("no error")
  4224  		} else if !strings.Contains(fmt.Sprint(err), "nil pointer to embedded struct") {
  4225  			t.Fatalf(`err=%q, wanted error containing "nil pointer to embedded struct"`, err)
  4226  		}
  4227  	}()
  4228  	v.FieldByName("F") // should panic
  4229  
  4230  	t.Fatalf("did not panic")
  4231  }
  4232  
  4233  // Given
  4234  //	type Outer struct {
  4235  //		*Inner
  4236  //		...
  4237  //	}
  4238  // the compiler generates the implementation of (*Outer).M dispatching to the embedded Inner.
  4239  // The implementation is logically:
  4240  //	func (p *Outer) M() {
  4241  //		(p.Inner).M()
  4242  //	}
  4243  // but since the only change here is the replacement of one pointer receiver with another,
  4244  // the actual generated code overwrites the original receiver with the p.Inner pointer and
  4245  // then jumps to the M method expecting the *Inner receiver.
  4246  //
  4247  // During reflect.Value.Call, we create an argument frame and the associated data structures
  4248  // to describe it to the garbage collector, populate the frame, call reflect.call to
  4249  // run a function call using that frame, and then copy the results back out of the frame.
  4250  // The reflect.call function does a memmove of the frame structure onto the
  4251  // stack (to set up the inputs), runs the call, and the memmoves the stack back to
  4252  // the frame structure (to preserve the outputs).
  4253  //
  4254  // Originally reflect.call did not distinguish inputs from outputs: both memmoves
  4255  // were for the full stack frame. However, in the case where the called function was
  4256  // one of these wrappers, the rewritten receiver is almost certainly a different type
  4257  // than the original receiver. This is not a problem on the stack, where we use the
  4258  // program counter to determine the type information and understand that
  4259  // during (*Outer).M the receiver is an *Outer while during (*Inner).M the receiver in the same
  4260  // memory word is now an *Inner. But in the statically typed argument frame created
  4261  // by reflect, the receiver is always an *Outer. Copying the modified receiver pointer
  4262  // off the stack into the frame will store an *Inner there, and then if a garbage collection
  4263  // happens to scan that argument frame before it is discarded, it will scan the *Inner
  4264  // memory as if it were an *Outer. If the two have different memory layouts, the
  4265  // collection will intepret the memory incorrectly.
  4266  //
  4267  // One such possible incorrect interpretation is to treat two arbitrary memory words
  4268  // (Inner.P1 and Inner.P2 below) as an interface (Outer.R below). Because interpreting
  4269  // an interface requires dereferencing the itab word, the misinterpretation will try to
  4270  // deference Inner.P1, causing a crash during garbage collection.
  4271  //
  4272  // This came up in a real program in issue 7725.
  4273  
  4274  type Outer struct {
  4275  	*Inner
  4276  	R io.Reader
  4277  }
  4278  
  4279  type Inner struct {
  4280  	X  *Outer
  4281  	P1 uintptr
  4282  	P2 uintptr
  4283  }
  4284  
  4285  func (pi *Inner) M() {
  4286  	// Clear references to pi so that the only way the
  4287  	// garbage collection will find the pointer is in the
  4288  	// argument frame, typed as a *Outer.
  4289  	pi.X.Inner = nil
  4290  
  4291  	// Set up an interface value that will cause a crash.
  4292  	// P1 = 1 is a non-zero, so the interface looks non-nil.
  4293  	// P2 = pi ensures that the data word points into the
  4294  	// allocated heap; if not the collection skips the interface
  4295  	// value as irrelevant, without dereferencing P1.
  4296  	pi.P1 = 1
  4297  	pi.P2 = uintptr(unsafe.Pointer(pi))
  4298  }
  4299  
  4300  func TestCallMethodJump(t *testing.T) {
  4301  	// In reflect.Value.Call, trigger a garbage collection after reflect.call
  4302  	// returns but before the args frame has been discarded.
  4303  	// This is a little clumsy but makes the failure repeatable.
  4304  	*CallGC = true
  4305  
  4306  	p := &Outer{Inner: new(Inner)}
  4307  	p.Inner.X = p
  4308  	ValueOf(p).Method(0).Call(nil)
  4309  
  4310  	// Stop garbage collecting during reflect.call.
  4311  	*CallGC = false
  4312  }
  4313  
  4314  func TestMakeFuncStackCopy(t *testing.T) {
  4315  	target := func(in []Value) []Value {
  4316  		runtime.GC()
  4317  		useStack(16)
  4318  		return []Value{ValueOf(9)}
  4319  	}
  4320  
  4321  	var concrete func(*int, int) int
  4322  	fn := MakeFunc(ValueOf(concrete).Type(), target)
  4323  	ValueOf(&concrete).Elem().Set(fn)
  4324  	x := concrete(nil, 7)
  4325  	if x != 9 {
  4326  		t.Errorf("have %#q want 9", x)
  4327  	}
  4328  }
  4329  
  4330  // use about n KB of stack
  4331  func useStack(n int) {
  4332  	if n == 0 {
  4333  		return
  4334  	}
  4335  	var b [1024]byte // makes frame about 1KB
  4336  	useStack(n - 1 + int(b[99]))
  4337  }
  4338  
  4339  type Impl struct{}
  4340  
  4341  func (Impl) f() {}
  4342  
  4343  func TestValueString(t *testing.T) {
  4344  	rv := ValueOf(Impl{})
  4345  	if rv.String() != "<reflect_test.Impl Value>" {
  4346  		t.Errorf("ValueOf(Impl{}).String() = %q, want %q", rv.String(), "<reflect_test.Impl Value>")
  4347  	}
  4348  
  4349  	method := rv.Method(0)
  4350  	if method.String() != "<func() Value>" {
  4351  		t.Errorf("ValueOf(Impl{}).Method(0).String() = %q, want %q", method.String(), "<func() Value>")
  4352  	}
  4353  }
  4354  
  4355  func TestInvalid(t *testing.T) {
  4356  	// Used to have inconsistency between IsValid() and Kind() != Invalid.
  4357  	type T struct{ v interface{} }
  4358  
  4359  	v := ValueOf(T{}).Field(0)
  4360  	if v.IsValid() != true || v.Kind() != Interface {
  4361  		t.Errorf("field: IsValid=%v, Kind=%v, want true, Interface", v.IsValid(), v.Kind())
  4362  	}
  4363  	v = v.Elem()
  4364  	if v.IsValid() != false || v.Kind() != Invalid {
  4365  		t.Errorf("field elem: IsValid=%v, Kind=%v, want false, Invalid", v.IsValid(), v.Kind())
  4366  	}
  4367  }
  4368  
  4369  // Issue 8917.
  4370  func TestLargeGCProg(t *testing.T) {
  4371  	fv := ValueOf(func([256]*byte) {})
  4372  	fv.Call([]Value{ValueOf([256]*byte{})})
  4373  }
  4374  
  4375  // Issue 9179.
  4376  func TestCallGC(t *testing.T) {
  4377  	f := func(a, b, c, d, e string) {
  4378  	}
  4379  	g := func(in []Value) []Value {
  4380  		runtime.GC()
  4381  		return nil
  4382  	}
  4383  	typ := ValueOf(f).Type()
  4384  	f2 := MakeFunc(typ, g).Interface().(func(string, string, string, string, string))
  4385  	f2("four", "five5", "six666", "seven77", "eight888")
  4386  }
  4387  
  4388  type funcLayoutTest struct {
  4389  	rcvr, t                  Type
  4390  	size, argsize, retOffset uintptr
  4391  	stack                    []byte // pointer bitmap: 1 is pointer, 0 is scalar (or uninitialized)
  4392  	gc                       []byte
  4393  }
  4394  
  4395  var funcLayoutTests []funcLayoutTest
  4396  
  4397  func init() {
  4398  	var argAlign uintptr = PtrSize
  4399  	if runtime.GOARCH == "amd64p32" {
  4400  		argAlign = 2 * PtrSize
  4401  	}
  4402  	roundup := func(x uintptr, a uintptr) uintptr {
  4403  		return (x + a - 1) / a * a
  4404  	}
  4405  
  4406  	funcLayoutTests = append(funcLayoutTests,
  4407  		funcLayoutTest{
  4408  			nil,
  4409  			ValueOf(func(a, b string) string { return "" }).Type(),
  4410  			6 * PtrSize,
  4411  			4 * PtrSize,
  4412  			4 * PtrSize,
  4413  			[]byte{1, 0, 1},
  4414  			[]byte{1, 0, 1, 0, 1},
  4415  		})
  4416  
  4417  	var r []byte
  4418  	if PtrSize == 4 {
  4419  		r = []byte{0, 0, 0, 1}
  4420  	} else {
  4421  		r = []byte{0, 0, 1}
  4422  	}
  4423  	funcLayoutTests = append(funcLayoutTests,
  4424  		funcLayoutTest{
  4425  			nil,
  4426  			ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(),
  4427  			roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
  4428  			roundup(3*4, PtrSize) + PtrSize + 2,
  4429  			roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign),
  4430  			r,
  4431  			r,
  4432  		})
  4433  
  4434  	funcLayoutTests = append(funcLayoutTests,
  4435  		funcLayoutTest{
  4436  			nil,
  4437  			ValueOf(func(a map[int]int, b uintptr, c interface{}) {}).Type(),
  4438  			4 * PtrSize,
  4439  			4 * PtrSize,
  4440  			4 * PtrSize,
  4441  			[]byte{1, 0, 1, 1},
  4442  			[]byte{1, 0, 1, 1},
  4443  		})
  4444  
  4445  	type S struct {
  4446  		a, b uintptr
  4447  		c, d *byte
  4448  	}
  4449  	funcLayoutTests = append(funcLayoutTests,
  4450  		funcLayoutTest{
  4451  			nil,
  4452  			ValueOf(func(a S) {}).Type(),
  4453  			4 * PtrSize,
  4454  			4 * PtrSize,
  4455  			4 * PtrSize,
  4456  			[]byte{0, 0, 1, 1},
  4457  			[]byte{0, 0, 1, 1},
  4458  		})
  4459  
  4460  	funcLayoutTests = append(funcLayoutTests,
  4461  		funcLayoutTest{
  4462  			ValueOf((*byte)(nil)).Type(),
  4463  			ValueOf(func(a uintptr, b *int) {}).Type(),
  4464  			roundup(3*PtrSize, argAlign),
  4465  			3 * PtrSize,
  4466  			roundup(3*PtrSize, argAlign),
  4467  			[]byte{1, 0, 1},
  4468  			[]byte{1, 0, 1},
  4469  		})
  4470  
  4471  	funcLayoutTests = append(funcLayoutTests,
  4472  		funcLayoutTest{
  4473  			nil,
  4474  			ValueOf(func(a uintptr) {}).Type(),
  4475  			roundup(PtrSize, argAlign),
  4476  			PtrSize,
  4477  			roundup(PtrSize, argAlign),
  4478  			[]byte{},
  4479  			[]byte{},
  4480  		})
  4481  
  4482  	funcLayoutTests = append(funcLayoutTests,
  4483  		funcLayoutTest{
  4484  			nil,
  4485  			ValueOf(func() uintptr { return 0 }).Type(),
  4486  			PtrSize,
  4487  			0,
  4488  			0,
  4489  			[]byte{},
  4490  			[]byte{},
  4491  		})
  4492  
  4493  	funcLayoutTests = append(funcLayoutTests,
  4494  		funcLayoutTest{
  4495  			ValueOf(uintptr(0)).Type(),
  4496  			ValueOf(func(a uintptr) {}).Type(),
  4497  			2 * PtrSize,
  4498  			2 * PtrSize,
  4499  			2 * PtrSize,
  4500  			[]byte{1},
  4501  			[]byte{1},
  4502  			// Note: this one is tricky, as the receiver is not a pointer.  But we
  4503  			// pass the receiver by reference to the autogenerated pointer-receiver
  4504  			// version of the function.
  4505  		})
  4506  }
  4507  
  4508  func TestFuncLayout(t *testing.T) {
  4509  	for _, lt := range funcLayoutTests {
  4510  		typ, argsize, retOffset, stack, gc, ptrs := FuncLayout(lt.t, lt.rcvr)
  4511  		if typ.Size() != lt.size {
  4512  			t.Errorf("funcLayout(%v, %v).size=%d, want %d", lt.t, lt.rcvr, typ.Size(), lt.size)
  4513  		}
  4514  		if argsize != lt.argsize {
  4515  			t.Errorf("funcLayout(%v, %v).argsize=%d, want %d", lt.t, lt.rcvr, argsize, lt.argsize)
  4516  		}
  4517  		if retOffset != lt.retOffset {
  4518  			t.Errorf("funcLayout(%v, %v).retOffset=%d, want %d", lt.t, lt.rcvr, retOffset, lt.retOffset)
  4519  		}
  4520  		if !bytes.Equal(stack, lt.stack) {
  4521  			t.Errorf("funcLayout(%v, %v).stack=%v, want %v", lt.t, lt.rcvr, stack, lt.stack)
  4522  		}
  4523  		if !bytes.Equal(gc, lt.gc) {
  4524  			t.Errorf("funcLayout(%v, %v).gc=%v, want %v", lt.t, lt.rcvr, gc, lt.gc)
  4525  		}
  4526  		if ptrs && len(stack) == 0 || !ptrs && len(stack) > 0 {
  4527  			t.Errorf("funcLayout(%v, %v) pointers flag=%v, want %v", lt.t, lt.rcvr, ptrs, !ptrs)
  4528  		}
  4529  	}
  4530  }
  4531  
  4532  func verifyGCBits(t *testing.T, typ Type, bits []byte) {
  4533  	heapBits := GCBits(New(typ).Interface())
  4534  	if !bytes.Equal(heapBits, bits) {
  4535  		t.Errorf("heapBits incorrect for %v\nhave %v\nwant %v", typ, heapBits, bits)
  4536  	}
  4537  }
  4538  
  4539  func verifyGCBitsSlice(t *testing.T, typ Type, cap int, bits []byte) {
  4540  	// Creating a slice causes the runtime to repeat a bitmap,
  4541  	// which exercises a different path from making the compiler
  4542  	// repeat a bitmap for a small array or executing a repeat in
  4543  	// a GC program.
  4544  	val := MakeSlice(typ, 0, cap)
  4545  	data := NewAt(ArrayOf(cap, typ), unsafe.Pointer(val.Pointer()))
  4546  	heapBits := GCBits(data.Interface())
  4547  	// Repeat the bitmap for the slice size, trimming scalars in
  4548  	// the last element.
  4549  	bits = rep(cap, bits)
  4550  	for len(bits) > 2 && bits[len(bits)-1] == 0 {
  4551  		bits = bits[:len(bits)-1]
  4552  	}
  4553  	if !bytes.Equal(heapBits, bits) {
  4554  		t.Errorf("heapBits incorrect for make(%v, 0, %v)\nhave %v\nwant %v", typ, cap, heapBits, bits)
  4555  	}
  4556  }
  4557  
  4558  func TestGCBits(t *testing.T) {
  4559  	verifyGCBits(t, TypeOf((*byte)(nil)), []byte{1})
  4560  
  4561  	// Building blocks for types seen by the compiler (like [2]Xscalar).
  4562  	// The compiler will create the type structures for the derived types,
  4563  	// including their GC metadata.
  4564  	type Xscalar struct{ x uintptr }
  4565  	type Xptr struct{ x *byte }
  4566  	type Xptrscalar struct {
  4567  		*byte
  4568  		uintptr
  4569  	}
  4570  	type Xscalarptr struct {
  4571  		uintptr
  4572  		*byte
  4573  	}
  4574  	type Xbigptrscalar struct {
  4575  		_ [100]*byte
  4576  		_ [100]uintptr
  4577  	}
  4578  
  4579  	var Tscalar, Tint64, Tptr, Tscalarptr, Tptrscalar, Tbigptrscalar Type
  4580  	{
  4581  		// Building blocks for types constructed by reflect.
  4582  		// This code is in a separate block so that code below
  4583  		// cannot accidentally refer to these.
  4584  		// The compiler must NOT see types derived from these
  4585  		// (for example, [2]Scalar must NOT appear in the program),
  4586  		// or else reflect will use it instead of having to construct one.
  4587  		// The goal is to test the construction.
  4588  		type Scalar struct{ x uintptr }
  4589  		type Ptr struct{ x *byte }
  4590  		type Ptrscalar struct {
  4591  			*byte
  4592  			uintptr
  4593  		}
  4594  		type Scalarptr struct {
  4595  			uintptr
  4596  			*byte
  4597  		}
  4598  		type Bigptrscalar struct {
  4599  			_ [100]*byte
  4600  			_ [100]uintptr
  4601  		}
  4602  		type Int64 int64
  4603  		Tscalar = TypeOf(Scalar{})
  4604  		Tint64 = TypeOf(Int64(0))
  4605  		Tptr = TypeOf(Ptr{})
  4606  		Tscalarptr = TypeOf(Scalarptr{})
  4607  		Tptrscalar = TypeOf(Ptrscalar{})
  4608  		Tbigptrscalar = TypeOf(Bigptrscalar{})
  4609  	}
  4610  
  4611  	empty := []byte{}
  4612  
  4613  	verifyGCBits(t, TypeOf(Xscalar{}), empty)
  4614  	verifyGCBits(t, Tscalar, empty)
  4615  	verifyGCBits(t, TypeOf(Xptr{}), lit(1))
  4616  	verifyGCBits(t, Tptr, lit(1))
  4617  	verifyGCBits(t, TypeOf(Xscalarptr{}), lit(0, 1))
  4618  	verifyGCBits(t, Tscalarptr, lit(0, 1))
  4619  	verifyGCBits(t, TypeOf(Xptrscalar{}), lit(1))
  4620  	verifyGCBits(t, Tptrscalar, lit(1))
  4621  
  4622  	verifyGCBits(t, TypeOf([0]Xptr{}), empty)
  4623  	verifyGCBits(t, ArrayOf(0, Tptr), empty)
  4624  	verifyGCBits(t, TypeOf([1]Xptrscalar{}), lit(1))
  4625  	verifyGCBits(t, ArrayOf(1, Tptrscalar), lit(1))
  4626  	verifyGCBits(t, TypeOf([2]Xscalar{}), empty)
  4627  	verifyGCBits(t, ArrayOf(2, Tscalar), empty)
  4628  	verifyGCBits(t, TypeOf([10000]Xscalar{}), empty)
  4629  	verifyGCBits(t, ArrayOf(10000, Tscalar), empty)
  4630  	verifyGCBits(t, TypeOf([2]Xptr{}), lit(1, 1))
  4631  	verifyGCBits(t, ArrayOf(2, Tptr), lit(1, 1))
  4632  	verifyGCBits(t, TypeOf([10000]Xptr{}), rep(10000, lit(1)))
  4633  	verifyGCBits(t, ArrayOf(10000, Tptr), rep(10000, lit(1)))
  4634  	verifyGCBits(t, TypeOf([2]Xscalarptr{}), lit(0, 1, 0, 1))
  4635  	verifyGCBits(t, ArrayOf(2, Tscalarptr), lit(0, 1, 0, 1))
  4636  	verifyGCBits(t, TypeOf([10000]Xscalarptr{}), rep(10000, lit(0, 1)))
  4637  	verifyGCBits(t, ArrayOf(10000, Tscalarptr), rep(10000, lit(0, 1)))
  4638  	verifyGCBits(t, TypeOf([2]Xptrscalar{}), lit(1, 0, 1))
  4639  	verifyGCBits(t, ArrayOf(2, Tptrscalar), lit(1, 0, 1))
  4640  	verifyGCBits(t, TypeOf([10000]Xptrscalar{}), rep(10000, lit(1, 0)))
  4641  	verifyGCBits(t, ArrayOf(10000, Tptrscalar), rep(10000, lit(1, 0)))
  4642  	verifyGCBits(t, TypeOf([1][10000]Xptrscalar{}), rep(10000, lit(1, 0)))
  4643  	verifyGCBits(t, ArrayOf(1, ArrayOf(10000, Tptrscalar)), rep(10000, lit(1, 0)))
  4644  	verifyGCBits(t, TypeOf([2][10000]Xptrscalar{}), rep(2*10000, lit(1, 0)))
  4645  	verifyGCBits(t, ArrayOf(2, ArrayOf(10000, Tptrscalar)), rep(2*10000, lit(1, 0)))
  4646  	verifyGCBits(t, TypeOf([4]Xbigptrscalar{}), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
  4647  	verifyGCBits(t, ArrayOf(4, Tbigptrscalar), join(rep(3, join(rep(100, lit(1)), rep(100, lit(0)))), rep(100, lit(1))))
  4648  
  4649  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 0, empty)
  4650  	verifyGCBitsSlice(t, SliceOf(Tptr), 0, empty)
  4651  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 1, lit(1))
  4652  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 1, lit(1))
  4653  	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 2, lit(0))
  4654  	verifyGCBitsSlice(t, SliceOf(Tscalar), 2, lit(0))
  4655  	verifyGCBitsSlice(t, TypeOf([]Xscalar{}), 10000, lit(0))
  4656  	verifyGCBitsSlice(t, SliceOf(Tscalar), 10000, lit(0))
  4657  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 2, lit(1))
  4658  	verifyGCBitsSlice(t, SliceOf(Tptr), 2, lit(1))
  4659  	verifyGCBitsSlice(t, TypeOf([]Xptr{}), 10000, lit(1))
  4660  	verifyGCBitsSlice(t, SliceOf(Tptr), 10000, lit(1))
  4661  	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 2, lit(0, 1))
  4662  	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 2, lit(0, 1))
  4663  	verifyGCBitsSlice(t, TypeOf([]Xscalarptr{}), 10000, lit(0, 1))
  4664  	verifyGCBitsSlice(t, SliceOf(Tscalarptr), 10000, lit(0, 1))
  4665  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 2, lit(1, 0))
  4666  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 2, lit(1, 0))
  4667  	verifyGCBitsSlice(t, TypeOf([]Xptrscalar{}), 10000, lit(1, 0))
  4668  	verifyGCBitsSlice(t, SliceOf(Tptrscalar), 10000, lit(1, 0))
  4669  	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 1, rep(10000, lit(1, 0)))
  4670  	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 1, rep(10000, lit(1, 0)))
  4671  	verifyGCBitsSlice(t, TypeOf([][10000]Xptrscalar{}), 2, rep(10000, lit(1, 0)))
  4672  	verifyGCBitsSlice(t, SliceOf(ArrayOf(10000, Tptrscalar)), 2, rep(10000, lit(1, 0)))
  4673  	verifyGCBitsSlice(t, TypeOf([]Xbigptrscalar{}), 4, join(rep(100, lit(1)), rep(100, lit(0))))
  4674  	verifyGCBitsSlice(t, SliceOf(Tbigptrscalar), 4, join(rep(100, lit(1)), rep(100, lit(0))))
  4675  
  4676  	verifyGCBits(t, TypeOf((chan [100]Xscalar)(nil)), lit(1))
  4677  	verifyGCBits(t, ChanOf(BothDir, ArrayOf(100, Tscalar)), lit(1))
  4678  
  4679  	verifyGCBits(t, TypeOf((func([10000]Xscalarptr))(nil)), lit(1))
  4680  	verifyGCBits(t, FuncOf([]Type{ArrayOf(10000, Tscalarptr)}, nil, false), lit(1))
  4681  
  4682  	verifyGCBits(t, TypeOf((map[[10000]Xscalarptr]Xscalar)(nil)), lit(1))
  4683  	verifyGCBits(t, MapOf(ArrayOf(10000, Tscalarptr), Tscalar), lit(1))
  4684  
  4685  	verifyGCBits(t, TypeOf((*[10000]Xscalar)(nil)), lit(1))
  4686  	verifyGCBits(t, PtrTo(ArrayOf(10000, Tscalar)), lit(1))
  4687  
  4688  	verifyGCBits(t, TypeOf(([][10000]Xscalar)(nil)), lit(1))
  4689  	verifyGCBits(t, SliceOf(ArrayOf(10000, Tscalar)), lit(1))
  4690  
  4691  	hdr := make([]byte, 8/PtrSize)
  4692  
  4693  	verifyMapBucket := func(t *testing.T, k, e Type, m interface{}, want []byte) {
  4694  		verifyGCBits(t, MapBucketOf(k, e), want)
  4695  		verifyGCBits(t, CachedBucketOf(TypeOf(m)), want)
  4696  	}
  4697  	verifyMapBucket(t,
  4698  		Tscalar, Tptr,
  4699  		map[Xscalar]Xptr(nil),
  4700  		join(hdr, rep(8, lit(0)), rep(8, lit(1)), lit(1)))
  4701  	verifyMapBucket(t,
  4702  		Tscalarptr, Tptr,
  4703  		map[Xscalarptr]Xptr(nil),
  4704  		join(hdr, rep(8, lit(0, 1)), rep(8, lit(1)), lit(1)))
  4705  	verifyMapBucket(t, Tint64, Tptr,
  4706  		map[int64]Xptr(nil),
  4707  		join(hdr, rep(8, rep(8/PtrSize, lit(0))), rep(8, lit(1)), naclpad(), lit(1)))
  4708  	verifyMapBucket(t,
  4709  		Tscalar, Tscalar,
  4710  		map[Xscalar]Xscalar(nil),
  4711  		empty)
  4712  	verifyMapBucket(t,
  4713  		ArrayOf(2, Tscalarptr), ArrayOf(3, Tptrscalar),
  4714  		map[[2]Xscalarptr][3]Xptrscalar(nil),
  4715  		join(hdr, rep(8*2, lit(0, 1)), rep(8*3, lit(1, 0)), lit(1)))
  4716  	verifyMapBucket(t,
  4717  		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
  4718  		map[[64 / PtrSize]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
  4719  		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
  4720  	verifyMapBucket(t,
  4721  		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize, Tptrscalar),
  4722  		map[[64/PtrSize + 1]Xscalarptr][64 / PtrSize]Xptrscalar(nil),
  4723  		join(hdr, rep(8, lit(1)), rep(8*64/PtrSize, lit(1, 0)), lit(1)))
  4724  	verifyMapBucket(t,
  4725  		ArrayOf(64/PtrSize, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
  4726  		map[[64 / PtrSize]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
  4727  		join(hdr, rep(8*64/PtrSize, lit(0, 1)), rep(8, lit(1)), lit(1)))
  4728  	verifyMapBucket(t,
  4729  		ArrayOf(64/PtrSize+1, Tscalarptr), ArrayOf(64/PtrSize+1, Tptrscalar),
  4730  		map[[64/PtrSize + 1]Xscalarptr][64/PtrSize + 1]Xptrscalar(nil),
  4731  		join(hdr, rep(8, lit(1)), rep(8, lit(1)), lit(1)))
  4732  }
  4733  
  4734  func naclpad() []byte {
  4735  	if runtime.GOARCH == "amd64p32" {
  4736  		return lit(0)
  4737  	}
  4738  	return nil
  4739  }
  4740  
  4741  func rep(n int, b []byte) []byte { return bytes.Repeat(b, n) }
  4742  func join(b ...[]byte) []byte    { return bytes.Join(b, nil) }
  4743  func lit(x ...byte) []byte       { return x }
  4744  
  4745  func TestTypeOfTypeOf(t *testing.T) {
  4746  	// Check that all the type constructors return concrete *rtype implementations.
  4747  	// It's difficult to test directly because the reflect package is only at arm's length.
  4748  	// The easiest thing to do is just call a function that crashes if it doesn't get an *rtype.
  4749  	check := func(name string, typ Type) {
  4750  		if underlying := TypeOf(typ).String(); underlying != "*reflect.rtype" {
  4751  			t.Errorf("%v returned %v, not *reflect.rtype", name, underlying)
  4752  		}
  4753  	}
  4754  
  4755  	type T struct{ int }
  4756  	check("TypeOf", TypeOf(T{}))
  4757  
  4758  	check("ArrayOf", ArrayOf(10, TypeOf(T{})))
  4759  	check("ChanOf", ChanOf(BothDir, TypeOf(T{})))
  4760  	check("FuncOf", FuncOf([]Type{TypeOf(T{})}, nil, false))
  4761  	check("MapOf", MapOf(TypeOf(T{}), TypeOf(T{})))
  4762  	check("PtrTo", PtrTo(TypeOf(T{})))
  4763  	check("SliceOf", SliceOf(TypeOf(T{})))
  4764  }
  4765  
  4766  type XM struct{}
  4767  
  4768  func (*XM) String() string { return "" }
  4769  
  4770  func TestPtrToMethods(t *testing.T) {
  4771  	var y struct{ XM }
  4772  	yp := New(TypeOf(y)).Interface()
  4773  	_, ok := yp.(fmt.Stringer)
  4774  	if !ok {
  4775  		t.Fatal("does not implement Stringer, but should")
  4776  	}
  4777  }