diff options
author | Tianon Gravi <admwiggin@gmail.com> | 2015-01-15 11:54:00 -0700 |
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committer | Tianon Gravi <admwiggin@gmail.com> | 2015-01-15 11:54:00 -0700 |
commit | f154da9e12608589e8d5f0508f908a0c3e88a1bb (patch) | |
tree | f8255d51e10c6f1e0ed69702200b966c9556a431 /src/reflect | |
parent | 8d8329ed5dfb9622c82a9fbec6fd99a580f9c9f6 (diff) | |
download | golang-upstream/1.4.tar.gz |
Imported Upstream version 1.4upstream/1.4
Diffstat (limited to 'src/reflect')
-rw-r--r-- | src/reflect/all_test.go | 4158 | ||||
-rw-r--r-- | src/reflect/asm_386.s | 30 | ||||
-rw-r--r-- | src/reflect/asm_amd64.s | 30 | ||||
-rw-r--r-- | src/reflect/asm_amd64p32.s | 30 | ||||
-rw-r--r-- | src/reflect/asm_arm.s | 30 | ||||
-rw-r--r-- | src/reflect/deepequal.go | 145 | ||||
-rw-r--r-- | src/reflect/example_test.go | 66 | ||||
-rw-r--r-- | src/reflect/export_test.go | 38 | ||||
-rw-r--r-- | src/reflect/makefunc.go | 129 | ||||
-rw-r--r-- | src/reflect/set_test.go | 211 | ||||
-rw-r--r-- | src/reflect/tostring_test.go | 95 | ||||
-rw-r--r-- | src/reflect/type.go | 1929 | ||||
-rw-r--r-- | src/reflect/value.go | 2443 |
13 files changed, 9334 insertions, 0 deletions
diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go new file mode 100644 index 000000000..7a01c95d8 --- /dev/null +++ b/src/reflect/all_test.go @@ -0,0 +1,4158 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package reflect_test + +import ( + "bytes" + "encoding/base64" + "flag" + "fmt" + "io" + "math/rand" + "os" + . "reflect" + "runtime" + "sort" + "strings" + "sync" + "testing" + "time" + "unsafe" +) + +func TestBool(t *testing.T) { + v := ValueOf(true) + if v.Bool() != true { + t.Fatal("ValueOf(true).Bool() = false") + } +} + +type integer int +type T struct { + a int + b float64 + c string + d *int +} + +type pair struct { + i interface{} + s string +} + +func isDigit(c uint8) bool { return '0' <= c && c <= '9' } + +func assert(t *testing.T, s, want string) { + if s != want { + t.Errorf("have %#q want %#q", s, want) + } +} + +func typestring(i interface{}) string { return TypeOf(i).String() } + +var typeTests = []pair{ + {struct{ x int }{}, "int"}, + {struct{ x int8 }{}, "int8"}, + {struct{ x int16 }{}, "int16"}, + {struct{ x int32 }{}, "int32"}, + {struct{ x int64 }{}, "int64"}, + {struct{ x uint }{}, "uint"}, + {struct{ x uint8 }{}, "uint8"}, + {struct{ x uint16 }{}, "uint16"}, + {struct{ x uint32 }{}, "uint32"}, + {struct{ x uint64 }{}, "uint64"}, + {struct{ x float32 }{}, "float32"}, + {struct{ x float64 }{}, "float64"}, + {struct{ x int8 }{}, "int8"}, + {struct{ x (**int8) }{}, "**int8"}, + {struct{ x (**integer) }{}, "**reflect_test.integer"}, + {struct{ x ([32]int32) }{}, "[32]int32"}, + {struct{ x ([]int8) }{}, "[]int8"}, + {struct{ x (map[string]int32) }{}, "map[string]int32"}, + {struct{ x (chan<- string) }{}, "chan<- string"}, + {struct { + x struct { + c chan *int32 + d float32 + } + }{}, + "struct { c chan *int32; d float32 }", + }, + {struct{ x (func(a int8, b int32)) }{}, "func(int8, int32)"}, + {struct { + x struct { + c func(chan *integer, *int8) + } + }{}, + "struct { c func(chan *reflect_test.integer, *int8) }", + }, + {struct { + x struct { + a int8 + b int32 + } + }{}, + "struct { a int8; b int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int32 + } + }{}, + "struct { a int8; b int8; c int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int8 + d int32 + } + }{}, + "struct { a int8; b int8; c int8; d int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int8 + d int8 + e int32 + } + }{}, + "struct { a int8; b int8; c int8; d int8; e int32 }", + }, + {struct { + x struct { + a int8 + b int8 + c int8 + d int8 + e int8 + f int32 + } + }{}, + "struct { a int8; b int8; c int8; d int8; e int8; f int32 }", + }, + {struct { + x struct { + a int8 `reflect:"hi there"` + } + }{}, + `struct { a int8 "reflect:\"hi there\"" }`, + }, + {struct { + x struct { + a int8 `reflect:"hi \x00there\t\n\"\\"` + } + }{}, + `struct { a int8 "reflect:\"hi \\x00there\\t\\n\\\"\\\\\"" }`, + }, + {struct { + x struct { + f func(args ...int) + } + }{}, + "struct { f func(...int) }", + }, + {struct { + x (interface { + a(func(func(int) int) func(func(int)) int) + b() + }) + }{}, + "interface { reflect_test.a(func(func(int) int) func(func(int)) int); reflect_test.b() }", + }, +} + +var valueTests = []pair{ + {new(int), "132"}, + {new(int8), "8"}, + {new(int16), "16"}, + {new(int32), "32"}, + {new(int64), "64"}, + {new(uint), "132"}, + {new(uint8), "8"}, + {new(uint16), "16"}, + {new(uint32), "32"}, + {new(uint64), "64"}, + {new(float32), "256.25"}, + {new(float64), "512.125"}, + {new(complex64), "532.125+10i"}, + {new(complex128), "564.25+1i"}, + {new(string), "stringy cheese"}, + {new(bool), "true"}, + {new(*int8), "*int8(0)"}, + {new(**int8), "**int8(0)"}, + {new([5]int32), "[5]int32{0, 0, 0, 0, 0}"}, + {new(**integer), "**reflect_test.integer(0)"}, + {new(map[string]int32), "map[string]int32{<can't iterate on maps>}"}, + {new(chan<- string), "chan<- string"}, + {new(func(a int8, b int32)), "func(int8, int32)(0)"}, + {new(struct { + c chan *int32 + d float32 + }), + "struct { c chan *int32; d float32 }{chan *int32, 0}", + }, + {new(struct{ c func(chan *integer, *int8) }), + "struct { c func(chan *reflect_test.integer, *int8) }{func(chan *reflect_test.integer, *int8)(0)}", + }, + {new(struct { + a int8 + b int32 + }), + "struct { a int8; b int32 }{0, 0}", + }, + {new(struct { + a int8 + b int8 + c int32 + }), + "struct { a int8; b int8; c int32 }{0, 0, 0}", + }, +} + +func testType(t *testing.T, i int, typ Type, want string) { + s := typ.String() + if s != want { + t.Errorf("#%d: have %#q, want %#q", i, s, want) + } +} + +func TestTypes(t *testing.T) { + for i, tt := range typeTests { + testType(t, i, ValueOf(tt.i).Field(0).Type(), tt.s) + } +} + +func TestSet(t *testing.T) { + for i, tt := range valueTests { + v := ValueOf(tt.i) + v = v.Elem() + switch v.Kind() { + case Int: + v.SetInt(132) + case Int8: + v.SetInt(8) + case Int16: + v.SetInt(16) + case Int32: + v.SetInt(32) + case Int64: + v.SetInt(64) + case Uint: + v.SetUint(132) + case Uint8: + v.SetUint(8) + case Uint16: + v.SetUint(16) + case Uint32: + v.SetUint(32) + case Uint64: + v.SetUint(64) + case Float32: + v.SetFloat(256.25) + case Float64: + v.SetFloat(512.125) + case Complex64: + v.SetComplex(532.125 + 10i) + case Complex128: + v.SetComplex(564.25 + 1i) + case String: + v.SetString("stringy cheese") + case Bool: + v.SetBool(true) + } + s := valueToString(v) + if s != tt.s { + t.Errorf("#%d: have %#q, want %#q", i, s, tt.s) + } + } +} + +func TestSetValue(t *testing.T) { + for i, tt := range valueTests { + v := ValueOf(tt.i).Elem() + switch v.Kind() { + case Int: + v.Set(ValueOf(int(132))) + case Int8: + v.Set(ValueOf(int8(8))) + case Int16: + v.Set(ValueOf(int16(16))) + case Int32: + v.Set(ValueOf(int32(32))) + case Int64: + v.Set(ValueOf(int64(64))) + case Uint: + v.Set(ValueOf(uint(132))) + case Uint8: + v.Set(ValueOf(uint8(8))) + case Uint16: + v.Set(ValueOf(uint16(16))) + case Uint32: + v.Set(ValueOf(uint32(32))) + case Uint64: + v.Set(ValueOf(uint64(64))) + case Float32: + v.Set(ValueOf(float32(256.25))) + case Float64: + v.Set(ValueOf(512.125)) + case Complex64: + v.Set(ValueOf(complex64(532.125 + 10i))) + case Complex128: + v.Set(ValueOf(complex128(564.25 + 1i))) + case String: + v.Set(ValueOf("stringy cheese")) + case Bool: + v.Set(ValueOf(true)) + } + s := valueToString(v) + if s != tt.s { + t.Errorf("#%d: have %#q, want %#q", i, s, tt.s) + } + } +} + +var _i = 7 + +var valueToStringTests = []pair{ + {123, "123"}, + {123.5, "123.5"}, + {byte(123), "123"}, + {"abc", "abc"}, + {T{123, 456.75, "hello", &_i}, "reflect_test.T{123, 456.75, hello, *int(&7)}"}, + {new(chan *T), "*chan *reflect_test.T(&chan *reflect_test.T)"}, + {[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"}, + {&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[10]int(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"}, + {[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}"}, + {&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, "*[]int(&[]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})"}, +} + +func TestValueToString(t *testing.T) { + for i, test := range valueToStringTests { + s := valueToString(ValueOf(test.i)) + if s != test.s { + t.Errorf("#%d: have %#q, want %#q", i, s, test.s) + } + } +} + +func TestArrayElemSet(t *testing.T) { + v := ValueOf(&[10]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).Elem() + v.Index(4).SetInt(123) + s := valueToString(v) + const want = "[10]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}" + if s != want { + t.Errorf("[10]int: have %#q want %#q", s, want) + } + + v = ValueOf([]int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}) + v.Index(4).SetInt(123) + s = valueToString(v) + const want1 = "[]int{1, 2, 3, 4, 123, 6, 7, 8, 9, 10}" + if s != want1 { + t.Errorf("[]int: have %#q want %#q", s, want1) + } +} + +func TestPtrPointTo(t *testing.T) { + var ip *int32 + var i int32 = 1234 + vip := ValueOf(&ip) + vi := ValueOf(&i).Elem() + vip.Elem().Set(vi.Addr()) + if *ip != 1234 { + t.Errorf("got %d, want 1234", *ip) + } + + ip = nil + vp := ValueOf(&ip).Elem() + vp.Set(Zero(vp.Type())) + if ip != nil { + t.Errorf("got non-nil (%p), want nil", ip) + } +} + +func TestPtrSetNil(t *testing.T) { + var i int32 = 1234 + ip := &i + vip := ValueOf(&ip) + vip.Elem().Set(Zero(vip.Elem().Type())) + if ip != nil { + t.Errorf("got non-nil (%d), want nil", *ip) + } +} + +func TestMapSetNil(t *testing.T) { + m := make(map[string]int) + vm := ValueOf(&m) + vm.Elem().Set(Zero(vm.Elem().Type())) + if m != nil { + t.Errorf("got non-nil (%p), want nil", m) + } +} + +func TestAll(t *testing.T) { + testType(t, 1, TypeOf((int8)(0)), "int8") + testType(t, 2, TypeOf((*int8)(nil)).Elem(), "int8") + + typ := TypeOf((*struct { + c chan *int32 + d float32 + })(nil)) + testType(t, 3, typ, "*struct { c chan *int32; d float32 }") + etyp := typ.Elem() + testType(t, 4, etyp, "struct { c chan *int32; d float32 }") + styp := etyp + f := styp.Field(0) + testType(t, 5, f.Type, "chan *int32") + + f, present := styp.FieldByName("d") + if !present { + t.Errorf("FieldByName says present field is absent") + } + testType(t, 6, f.Type, "float32") + + f, present = styp.FieldByName("absent") + if present { + t.Errorf("FieldByName says absent field is present") + } + + typ = TypeOf([32]int32{}) + testType(t, 7, typ, "[32]int32") + testType(t, 8, typ.Elem(), "int32") + + typ = TypeOf((map[string]*int32)(nil)) + testType(t, 9, typ, "map[string]*int32") + mtyp := typ + testType(t, 10, mtyp.Key(), "string") + testType(t, 11, mtyp.Elem(), "*int32") + + typ = TypeOf((chan<- string)(nil)) + testType(t, 12, typ, "chan<- string") + testType(t, 13, typ.Elem(), "string") + + // make sure tag strings are not part of element type + typ = TypeOf(struct { + d []uint32 `reflect:"TAG"` + }{}).Field(0).Type + testType(t, 14, typ, "[]uint32") +} + +func TestInterfaceGet(t *testing.T) { + var inter struct { + E interface{} + } + inter.E = 123.456 + v1 := ValueOf(&inter) + v2 := v1.Elem().Field(0) + assert(t, v2.Type().String(), "interface {}") + i2 := v2.Interface() + v3 := ValueOf(i2) + assert(t, v3.Type().String(), "float64") +} + +func TestInterfaceValue(t *testing.T) { + var inter struct { + E interface{} + } + inter.E = 123.456 + v1 := ValueOf(&inter) + v2 := v1.Elem().Field(0) + assert(t, v2.Type().String(), "interface {}") + v3 := v2.Elem() + assert(t, v3.Type().String(), "float64") + + i3 := v2.Interface() + if _, ok := i3.(float64); !ok { + t.Error("v2.Interface() did not return float64, got ", TypeOf(i3)) + } +} + +func TestFunctionValue(t *testing.T) { + var x interface{} = func() {} + v := ValueOf(x) + if fmt.Sprint(v.Interface()) != fmt.Sprint(x) { + t.Fatalf("TestFunction returned wrong pointer") + } + assert(t, v.Type().String(), "func()") +} + +var appendTests = []struct { + orig, extra []int +}{ + {make([]int, 2, 4), []int{22}}, + {make([]int, 2, 4), []int{22, 33, 44}}, +} + +func sameInts(x, y []int) bool { + if len(x) != len(y) { + return false + } + for i, xx := range x { + if xx != y[i] { + return false + } + } + return true +} + +func TestAppend(t *testing.T) { + for i, test := range appendTests { + origLen, extraLen := len(test.orig), len(test.extra) + want := append(test.orig, test.extra...) + // Convert extra from []int to []Value. + e0 := make([]Value, len(test.extra)) + for j, e := range test.extra { + e0[j] = ValueOf(e) + } + // Convert extra from []int to *SliceValue. + e1 := ValueOf(test.extra) + // Test Append. + a0 := ValueOf(test.orig) + have0 := Append(a0, e0...).Interface().([]int) + if !sameInts(have0, want) { + t.Errorf("Append #%d: have %v, want %v (%p %p)", i, have0, want, test.orig, have0) + } + // Check that the orig and extra slices were not modified. + if len(test.orig) != origLen { + t.Errorf("Append #%d origLen: have %v, want %v", i, len(test.orig), origLen) + } + if len(test.extra) != extraLen { + t.Errorf("Append #%d extraLen: have %v, want %v", i, len(test.extra), extraLen) + } + // Test AppendSlice. + a1 := ValueOf(test.orig) + have1 := AppendSlice(a1, e1).Interface().([]int) + if !sameInts(have1, want) { + t.Errorf("AppendSlice #%d: have %v, want %v", i, have1, want) + } + // Check that the orig and extra slices were not modified. + if len(test.orig) != origLen { + t.Errorf("AppendSlice #%d origLen: have %v, want %v", i, len(test.orig), origLen) + } + if len(test.extra) != extraLen { + t.Errorf("AppendSlice #%d extraLen: have %v, want %v", i, len(test.extra), extraLen) + } + } +} + +func TestCopy(t *testing.T) { + a := []int{1, 2, 3, 4, 10, 9, 8, 7} + b := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44} + c := []int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44} + for i := 0; i < len(b); i++ { + if b[i] != c[i] { + t.Fatalf("b != c before test") + } + } + a1 := a + b1 := b + aa := ValueOf(&a1).Elem() + ab := ValueOf(&b1).Elem() + for tocopy := 1; tocopy <= 7; tocopy++ { + aa.SetLen(tocopy) + Copy(ab, aa) + aa.SetLen(8) + for i := 0; i < tocopy; i++ { + if a[i] != b[i] { + t.Errorf("(i) tocopy=%d a[%d]=%d, b[%d]=%d", + tocopy, i, a[i], i, b[i]) + } + } + for i := tocopy; i < len(b); i++ { + if b[i] != c[i] { + if i < len(a) { + t.Errorf("(ii) tocopy=%d a[%d]=%d, b[%d]=%d, c[%d]=%d", + tocopy, i, a[i], i, b[i], i, c[i]) + } else { + t.Errorf("(iii) tocopy=%d b[%d]=%d, c[%d]=%d", + tocopy, i, b[i], i, c[i]) + } + } else { + t.Logf("tocopy=%d elem %d is okay\n", tocopy, i) + } + } + } +} + +func TestCopyArray(t *testing.T) { + a := [8]int{1, 2, 3, 4, 10, 9, 8, 7} + b := [11]int{11, 22, 33, 44, 1010, 99, 88, 77, 66, 55, 44} + c := b + aa := ValueOf(&a).Elem() + ab := ValueOf(&b).Elem() + Copy(ab, aa) + for i := 0; i < len(a); i++ { + if a[i] != b[i] { + t.Errorf("(i) a[%d]=%d, b[%d]=%d", i, a[i], i, b[i]) + } + } + for i := len(a); i < len(b); i++ { + if b[i] != c[i] { + t.Errorf("(ii) b[%d]=%d, c[%d]=%d", i, b[i], i, c[i]) + } else { + t.Logf("elem %d is okay\n", i) + } + } +} + +func TestBigUnnamedStruct(t *testing.T) { + b := struct{ a, b, c, d int64 }{1, 2, 3, 4} + v := ValueOf(b) + b1 := v.Interface().(struct { + a, b, c, d int64 + }) + if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d { + t.Errorf("ValueOf(%v).Interface().(*Big) = %v", b, b1) + } +} + +type big struct { + a, b, c, d, e int64 +} + +func TestBigStruct(t *testing.T) { + b := big{1, 2, 3, 4, 5} + v := ValueOf(b) + b1 := v.Interface().(big) + if b1.a != b.a || b1.b != b.b || b1.c != b.c || b1.d != b.d || b1.e != b.e { + t.Errorf("ValueOf(%v).Interface().(big) = %v", b, b1) + } +} + +type Basic struct { + x int + y float32 +} + +type NotBasic Basic + +type DeepEqualTest struct { + a, b interface{} + eq bool +} + +// Simple functions for DeepEqual tests. +var ( + fn1 func() // nil. + fn2 func() // nil. + fn3 = func() { fn1() } // Not nil. +) + +var deepEqualTests = []DeepEqualTest{ + // Equalities + {nil, nil, true}, + {1, 1, true}, + {int32(1), int32(1), true}, + {0.5, 0.5, true}, + {float32(0.5), float32(0.5), true}, + {"hello", "hello", true}, + {make([]int, 10), make([]int, 10), true}, + {&[3]int{1, 2, 3}, &[3]int{1, 2, 3}, true}, + {Basic{1, 0.5}, Basic{1, 0.5}, true}, + {error(nil), error(nil), true}, + {map[int]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, true}, + {fn1, fn2, true}, + + // Inequalities + {1, 2, false}, + {int32(1), int32(2), false}, + {0.5, 0.6, false}, + {float32(0.5), float32(0.6), false}, + {"hello", "hey", false}, + {make([]int, 10), make([]int, 11), false}, + {&[3]int{1, 2, 3}, &[3]int{1, 2, 4}, false}, + {Basic{1, 0.5}, Basic{1, 0.6}, false}, + {Basic{1, 0}, Basic{2, 0}, false}, + {map[int]string{1: "one", 3: "two"}, map[int]string{2: "two", 1: "one"}, false}, + {map[int]string{1: "one", 2: "txo"}, map[int]string{2: "two", 1: "one"}, false}, + {map[int]string{1: "one"}, map[int]string{2: "two", 1: "one"}, false}, + {map[int]string{2: "two", 1: "one"}, map[int]string{1: "one"}, false}, + {nil, 1, false}, + {1, nil, false}, + {fn1, fn3, false}, + {fn3, fn3, false}, + {[][]int{{1}}, [][]int{{2}}, false}, + + // Nil vs empty: not the same. + {[]int{}, []int(nil), false}, + {[]int{}, []int{}, true}, + {[]int(nil), []int(nil), true}, + {map[int]int{}, map[int]int(nil), false}, + {map[int]int{}, map[int]int{}, true}, + {map[int]int(nil), map[int]int(nil), true}, + + // Mismatched types + {1, 1.0, false}, + {int32(1), int64(1), false}, + {0.5, "hello", false}, + {[]int{1, 2, 3}, [3]int{1, 2, 3}, false}, + {&[3]interface{}{1, 2, 4}, &[3]interface{}{1, 2, "s"}, false}, + {Basic{1, 0.5}, NotBasic{1, 0.5}, false}, + {map[uint]string{1: "one", 2: "two"}, map[int]string{2: "two", 1: "one"}, false}, +} + +func TestDeepEqual(t *testing.T) { + for _, test := range deepEqualTests { + if r := DeepEqual(test.a, test.b); r != test.eq { + t.Errorf("DeepEqual(%v, %v) = %v, want %v", test.a, test.b, r, test.eq) + } + } +} + +func TestTypeOf(t *testing.T) { + // Special case for nil + if typ := TypeOf(nil); typ != nil { + t.Errorf("expected nil type for nil value; got %v", typ) + } + for _, test := range deepEqualTests { + v := ValueOf(test.a) + if !v.IsValid() { + continue + } + typ := TypeOf(test.a) + if typ != v.Type() { + t.Errorf("TypeOf(%v) = %v, but ValueOf(%v).Type() = %v", test.a, typ, test.a, v.Type()) + } + } +} + +type Recursive struct { + x int + r *Recursive +} + +func TestDeepEqualRecursiveStruct(t *testing.T) { + a, b := new(Recursive), new(Recursive) + *a = Recursive{12, a} + *b = Recursive{12, b} + if !DeepEqual(a, b) { + t.Error("DeepEqual(recursive same) = false, want true") + } +} + +type _Complex struct { + a int + b [3]*_Complex + c *string + d map[float64]float64 +} + +func TestDeepEqualComplexStruct(t *testing.T) { + m := make(map[float64]float64) + stra, strb := "hello", "hello" + a, b := new(_Complex), new(_Complex) + *a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m} + *b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m} + if !DeepEqual(a, b) { + t.Error("DeepEqual(complex same) = false, want true") + } +} + +func TestDeepEqualComplexStructInequality(t *testing.T) { + m := make(map[float64]float64) + stra, strb := "hello", "helloo" // Difference is here + a, b := new(_Complex), new(_Complex) + *a = _Complex{5, [3]*_Complex{a, b, a}, &stra, m} + *b = _Complex{5, [3]*_Complex{b, a, a}, &strb, m} + if DeepEqual(a, b) { + t.Error("DeepEqual(complex different) = true, want false") + } +} + +type UnexpT struct { + m map[int]int +} + +func TestDeepEqualUnexportedMap(t *testing.T) { + // Check that DeepEqual can look at unexported fields. + x1 := UnexpT{map[int]int{1: 2}} + x2 := UnexpT{map[int]int{1: 2}} + if !DeepEqual(&x1, &x2) { + t.Error("DeepEqual(x1, x2) = false, want true") + } + + y1 := UnexpT{map[int]int{2: 3}} + if DeepEqual(&x1, &y1) { + t.Error("DeepEqual(x1, y1) = true, want false") + } +} + +func check2ndField(x interface{}, offs uintptr, t *testing.T) { + s := ValueOf(x) + f := s.Type().Field(1) + if f.Offset != offs { + t.Error("mismatched offsets in structure alignment:", f.Offset, offs) + } +} + +// Check that structure alignment & offsets viewed through reflect agree with those +// from the compiler itself. +func TestAlignment(t *testing.T) { + type T1inner struct { + a int + } + type T1 struct { + T1inner + f int + } + type T2inner struct { + a, b int + } + type T2 struct { + T2inner + f int + } + + x := T1{T1inner{2}, 17} + check2ndField(x, uintptr(unsafe.Pointer(&x.f))-uintptr(unsafe.Pointer(&x)), t) + + x1 := T2{T2inner{2, 3}, 17} + check2ndField(x1, uintptr(unsafe.Pointer(&x1.f))-uintptr(unsafe.Pointer(&x1)), t) +} + +func Nil(a interface{}, t *testing.T) { + n := ValueOf(a).Field(0) + if !n.IsNil() { + t.Errorf("%v should be nil", a) + } +} + +func NotNil(a interface{}, t *testing.T) { + n := ValueOf(a).Field(0) + if n.IsNil() { + t.Errorf("value of type %v should not be nil", ValueOf(a).Type().String()) + } +} + +func TestIsNil(t *testing.T) { + // These implement IsNil. + // Wrap in extra struct to hide interface type. + doNil := []interface{}{ + struct{ x *int }{}, + struct{ x interface{} }{}, + struct{ x map[string]int }{}, + struct{ x func() bool }{}, + struct{ x chan int }{}, + struct{ x []string }{}, + } + for _, ts := range doNil { + ty := TypeOf(ts).Field(0).Type + v := Zero(ty) + v.IsNil() // panics if not okay to call + } + + // Check the implementations + var pi struct { + x *int + } + Nil(pi, t) + pi.x = new(int) + NotNil(pi, t) + + var si struct { + x []int + } + Nil(si, t) + si.x = make([]int, 10) + NotNil(si, t) + + var ci struct { + x chan int + } + Nil(ci, t) + ci.x = make(chan int) + NotNil(ci, t) + + var mi struct { + x map[int]int + } + Nil(mi, t) + mi.x = make(map[int]int) + NotNil(mi, t) + + var ii struct { + x interface{} + } + Nil(ii, t) + ii.x = 2 + NotNil(ii, t) + + var fi struct { + x func(t *testing.T) + } + Nil(fi, t) + fi.x = TestIsNil + NotNil(fi, t) +} + +func TestInterfaceExtraction(t *testing.T) { + var s struct { + W io.Writer + } + + s.W = os.Stdout + v := Indirect(ValueOf(&s)).Field(0).Interface() + if v != s.W.(interface{}) { + t.Error("Interface() on interface: ", v, s.W) + } +} + +func TestNilPtrValueSub(t *testing.T) { + var pi *int + if pv := ValueOf(pi); pv.Elem().IsValid() { + t.Error("ValueOf((*int)(nil)).Elem().IsValid()") + } +} + +func TestMap(t *testing.T) { + m := map[string]int{"a": 1, "b": 2} + mv := ValueOf(m) + if n := mv.Len(); n != len(m) { + t.Errorf("Len = %d, want %d", n, len(m)) + } + keys := mv.MapKeys() + newmap := MakeMap(mv.Type()) + for k, v := range m { + // Check that returned Keys match keys in range. + // These aren't required to be in the same order. + seen := false + for _, kv := range keys { + if kv.String() == k { + seen = true + break + } + } + if !seen { + t.Errorf("Missing key %q", k) + } + + // Check that value lookup is correct. + vv := mv.MapIndex(ValueOf(k)) + if vi := vv.Int(); vi != int64(v) { + t.Errorf("Key %q: have value %d, want %d", k, vi, v) + } + + // Copy into new map. + newmap.SetMapIndex(ValueOf(k), ValueOf(v)) + } + vv := mv.MapIndex(ValueOf("not-present")) + if vv.IsValid() { + t.Errorf("Invalid key: got non-nil value %s", valueToString(vv)) + } + + newm := newmap.Interface().(map[string]int) + if len(newm) != len(m) { + t.Errorf("length after copy: newm=%d, m=%d", len(newm), len(m)) + } + + for k, v := range newm { + mv, ok := m[k] + if mv != v { + t.Errorf("newm[%q] = %d, but m[%q] = %d, %v", k, v, k, mv, ok) + } + } + + newmap.SetMapIndex(ValueOf("a"), Value{}) + v, ok := newm["a"] + if ok { + t.Errorf("newm[\"a\"] = %d after delete", v) + } + + mv = ValueOf(&m).Elem() + mv.Set(Zero(mv.Type())) + if m != nil { + t.Errorf("mv.Set(nil) failed") + } +} + +func TestNilMap(t *testing.T) { + var m map[string]int + mv := ValueOf(m) + keys := mv.MapKeys() + if len(keys) != 0 { + t.Errorf(">0 keys for nil map: %v", keys) + } + + // Check that value for missing key is zero. + x := mv.MapIndex(ValueOf("hello")) + if x.Kind() != Invalid { + t.Errorf("m.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x) + } + + // Check big value too. + var mbig map[string][10 << 20]byte + x = ValueOf(mbig).MapIndex(ValueOf("hello")) + if x.Kind() != Invalid { + t.Errorf("mbig.MapIndex(\"hello\") for nil map = %v, want Invalid Value", x) + } + + // Test that deletes from a nil map succeed. + mv.SetMapIndex(ValueOf("hi"), Value{}) +} + +func TestChan(t *testing.T) { + for loop := 0; loop < 2; loop++ { + var c chan int + var cv Value + + // check both ways to allocate channels + switch loop { + case 1: + c = make(chan int, 1) + cv = ValueOf(c) + case 0: + cv = MakeChan(TypeOf(c), 1) + c = cv.Interface().(chan int) + } + + // Send + cv.Send(ValueOf(2)) + if i := <-c; i != 2 { + t.Errorf("reflect Send 2, native recv %d", i) + } + + // Recv + c <- 3 + if i, ok := cv.Recv(); i.Int() != 3 || !ok { + t.Errorf("native send 3, reflect Recv %d, %t", i.Int(), ok) + } + + // TryRecv fail + val, ok := cv.TryRecv() + if val.IsValid() || ok { + t.Errorf("TryRecv on empty chan: %s, %t", valueToString(val), ok) + } + + // TryRecv success + c <- 4 + val, ok = cv.TryRecv() + if !val.IsValid() { + t.Errorf("TryRecv on ready chan got nil") + } else if i := val.Int(); i != 4 || !ok { + t.Errorf("native send 4, TryRecv %d, %t", i, ok) + } + + // TrySend fail + c <- 100 + ok = cv.TrySend(ValueOf(5)) + i := <-c + if ok { + t.Errorf("TrySend on full chan succeeded: value %d", i) + } + + // TrySend success + ok = cv.TrySend(ValueOf(6)) + if !ok { + t.Errorf("TrySend on empty chan failed") + } else { + if i = <-c; i != 6 { + t.Errorf("TrySend 6, recv %d", i) + } + } + + // Close + c <- 123 + cv.Close() + if i, ok := cv.Recv(); i.Int() != 123 || !ok { + t.Errorf("send 123 then close; Recv %d, %t", i.Int(), ok) + } + if i, ok := cv.Recv(); i.Int() != 0 || ok { + t.Errorf("after close Recv %d, %t", i.Int(), ok) + } + } + + // check creation of unbuffered channel + var c chan int + cv := MakeChan(TypeOf(c), 0) + c = cv.Interface().(chan int) + if cv.TrySend(ValueOf(7)) { + t.Errorf("TrySend on sync chan succeeded") + } + if v, ok := cv.TryRecv(); v.IsValid() || ok { + t.Errorf("TryRecv on sync chan succeeded: isvalid=%v ok=%v", v.IsValid(), ok) + } + + // len/cap + cv = MakeChan(TypeOf(c), 10) + c = cv.Interface().(chan int) + for i := 0; i < 3; i++ { + c <- i + } + if l, m := cv.Len(), cv.Cap(); l != len(c) || m != cap(c) { + t.Errorf("Len/Cap = %d/%d want %d/%d", l, m, len(c), cap(c)) + } +} + +// caseInfo describes a single case in a select test. +type caseInfo struct { + desc string + canSelect bool + recv Value + closed bool + helper func() + panic bool +} + +var allselect = flag.Bool("allselect", false, "exhaustive select test") + +func TestSelect(t *testing.T) { + selectWatch.once.Do(func() { go selectWatcher() }) + + var x exhaustive + nch := 0 + newop := func(n int, cap int) (ch, val Value) { + nch++ + if nch%101%2 == 1 { + c := make(chan int, cap) + ch = ValueOf(c) + val = ValueOf(n) + } else { + c := make(chan string, cap) + ch = ValueOf(c) + val = ValueOf(fmt.Sprint(n)) + } + return + } + + for n := 0; x.Next(); n++ { + if testing.Short() && n >= 1000 { + break + } + if n >= 100000 && !*allselect { + break + } + if n%100000 == 0 && testing.Verbose() { + println("TestSelect", n) + } + var cases []SelectCase + var info []caseInfo + + // Ready send. + if x.Maybe() { + ch, val := newop(len(cases), 1) + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ch, + Send: val, + }) + info = append(info, caseInfo{desc: "ready send", canSelect: true}) + } + + // Ready recv. + if x.Maybe() { + ch, val := newop(len(cases), 1) + ch.Send(val) + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ch, + }) + info = append(info, caseInfo{desc: "ready recv", canSelect: true, recv: val}) + } + + // Blocking send. + if x.Maybe() { + ch, val := newop(len(cases), 0) + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ch, + Send: val, + }) + // Let it execute? + if x.Maybe() { + f := func() { ch.Recv() } + info = append(info, caseInfo{desc: "blocking send", helper: f}) + } else { + info = append(info, caseInfo{desc: "blocking send"}) + } + } + + // Blocking recv. + if x.Maybe() { + ch, val := newop(len(cases), 0) + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ch, + }) + // Let it execute? + if x.Maybe() { + f := func() { ch.Send(val) } + info = append(info, caseInfo{desc: "blocking recv", recv: val, helper: f}) + } else { + info = append(info, caseInfo{desc: "blocking recv"}) + } + } + + // Zero Chan send. + if x.Maybe() { + // Maybe include value to send. + var val Value + if x.Maybe() { + val = ValueOf(100) + } + cases = append(cases, SelectCase{ + Dir: SelectSend, + Send: val, + }) + info = append(info, caseInfo{desc: "zero Chan send"}) + } + + // Zero Chan receive. + if x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectRecv, + }) + info = append(info, caseInfo{desc: "zero Chan recv"}) + } + + // nil Chan send. + if x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ValueOf((chan int)(nil)), + Send: ValueOf(101), + }) + info = append(info, caseInfo{desc: "nil Chan send"}) + } + + // nil Chan recv. + if x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ValueOf((chan int)(nil)), + }) + info = append(info, caseInfo{desc: "nil Chan recv"}) + } + + // closed Chan send. + if x.Maybe() { + ch := make(chan int) + close(ch) + cases = append(cases, SelectCase{ + Dir: SelectSend, + Chan: ValueOf(ch), + Send: ValueOf(101), + }) + info = append(info, caseInfo{desc: "closed Chan send", canSelect: true, panic: true}) + } + + // closed Chan recv. + if x.Maybe() { + ch, val := newop(len(cases), 0) + ch.Close() + val = Zero(val.Type()) + cases = append(cases, SelectCase{ + Dir: SelectRecv, + Chan: ch, + }) + info = append(info, caseInfo{desc: "closed Chan recv", canSelect: true, closed: true, recv: val}) + } + + var helper func() // goroutine to help the select complete + + // Add default? Must be last case here, but will permute. + // Add the default if the select would otherwise + // block forever, and maybe add it anyway. + numCanSelect := 0 + canProceed := false + canBlock := true + canPanic := false + helpers := []int{} + for i, c := range info { + if c.canSelect { + canProceed = true + canBlock = false + numCanSelect++ + if c.panic { + canPanic = true + } + } else if c.helper != nil { + canProceed = true + helpers = append(helpers, i) + } + } + if !canProceed || x.Maybe() { + cases = append(cases, SelectCase{ + Dir: SelectDefault, + }) + info = append(info, caseInfo{desc: "default", canSelect: canBlock}) + numCanSelect++ + } else if canBlock { + // Select needs to communicate with another goroutine. + cas := &info[helpers[x.Choose(len(helpers))]] + helper = cas.helper + cas.canSelect = true + numCanSelect++ + } + + // Permute cases and case info. + // Doing too much here makes the exhaustive loop + // too exhausting, so just do two swaps. + for loop := 0; loop < 2; loop++ { + i := x.Choose(len(cases)) + j := x.Choose(len(cases)) + cases[i], cases[j] = cases[j], cases[i] + info[i], info[j] = info[j], info[i] + } + + if helper != nil { + // We wait before kicking off a goroutine to satisfy a blocked select. + // The pause needs to be big enough to let the select block before + // we run the helper, but if we lose that race once in a while it's okay: the + // select will just proceed immediately. Not a big deal. + // For short tests we can grow [sic] the timeout a bit without fear of taking too long + pause := 10 * time.Microsecond + if testing.Short() { + pause = 100 * time.Microsecond + } + time.AfterFunc(pause, helper) + } + + // Run select. + i, recv, recvOK, panicErr := runSelect(cases, info) + if panicErr != nil && !canPanic { + t.Fatalf("%s\npanicked unexpectedly: %v", fmtSelect(info), panicErr) + } + if panicErr == nil && canPanic && numCanSelect == 1 { + t.Fatalf("%s\nselected #%d incorrectly (should panic)", fmtSelect(info), i) + } + if panicErr != nil { + continue + } + + cas := info[i] + if !cas.canSelect { + recvStr := "" + if recv.IsValid() { + recvStr = fmt.Sprintf(", received %v, %v", recv.Interface(), recvOK) + } + t.Fatalf("%s\nselected #%d incorrectly%s", fmtSelect(info), i, recvStr) + continue + } + if cas.panic { + t.Fatalf("%s\nselected #%d incorrectly (case should panic)", fmtSelect(info), i) + continue + } + + if cases[i].Dir == SelectRecv { + if !recv.IsValid() { + t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, cas.recv.Interface(), !cas.closed) + } + if !cas.recv.IsValid() { + t.Fatalf("%s\nselected #%d but internal error: missing recv value", fmtSelect(info), i) + } + if recv.Interface() != cas.recv.Interface() || recvOK != !cas.closed { + if recv.Interface() == cas.recv.Interface() && recvOK == !cas.closed { + t.Fatalf("%s\nselected #%d, got %#v, %v, and DeepEqual is broken on %T", fmtSelect(info), i, recv.Interface(), recvOK, recv.Interface()) + } + t.Fatalf("%s\nselected #%d but got %#v, %v, want %#v, %v", fmtSelect(info), i, recv.Interface(), recvOK, cas.recv.Interface(), !cas.closed) + } + } else { + if recv.IsValid() || recvOK { + t.Fatalf("%s\nselected #%d but got %v, %v, want %v, %v", fmtSelect(info), i, recv, recvOK, Value{}, false) + } + } + } +} + +// selectWatch and the selectWatcher are a watchdog mechanism for running Select. +// If the selectWatcher notices that the select has been blocked for >1 second, it prints +// an error describing the select and panics the entire test binary. +var selectWatch struct { + sync.Mutex + once sync.Once + now time.Time + info []caseInfo +} + +func selectWatcher() { + for { + time.Sleep(1 * time.Second) + selectWatch.Lock() + if selectWatch.info != nil && time.Since(selectWatch.now) > 1*time.Second { + fmt.Fprintf(os.Stderr, "TestSelect:\n%s blocked indefinitely\n", fmtSelect(selectWatch.info)) + panic("select stuck") + } + selectWatch.Unlock() + } +} + +// runSelect runs a single select test. +// It returns the values returned by Select but also returns +// a panic value if the Select panics. +func runSelect(cases []SelectCase, info []caseInfo) (chosen int, recv Value, recvOK bool, panicErr interface{}) { + defer func() { + panicErr = recover() + + selectWatch.Lock() + selectWatch.info = nil + selectWatch.Unlock() + }() + + selectWatch.Lock() + selectWatch.now = time.Now() + selectWatch.info = info + selectWatch.Unlock() + + chosen, recv, recvOK = Select(cases) + return +} + +// fmtSelect formats the information about a single select test. +func fmtSelect(info []caseInfo) string { + var buf bytes.Buffer + fmt.Fprintf(&buf, "\nselect {\n") + for i, cas := range info { + fmt.Fprintf(&buf, "%d: %s", i, cas.desc) + if cas.recv.IsValid() { + fmt.Fprintf(&buf, " val=%#v", cas.recv.Interface()) + } + if cas.canSelect { + fmt.Fprintf(&buf, " canselect") + } + if cas.panic { + fmt.Fprintf(&buf, " panic") + } + fmt.Fprintf(&buf, "\n") + } + fmt.Fprintf(&buf, "}") + return buf.String() +} + +type two [2]uintptr + +// Difficult test for function call because of +// implicit padding between arguments. +func dummy(b byte, c int, d byte, e two, f byte, g float32, h byte) (i byte, j int, k byte, l two, m byte, n float32, o byte) { + return b, c, d, e, f, g, h +} + +func TestFunc(t *testing.T) { + ret := ValueOf(dummy).Call([]Value{ + ValueOf(byte(10)), + ValueOf(20), + ValueOf(byte(30)), + ValueOf(two{40, 50}), + ValueOf(byte(60)), + ValueOf(float32(70)), + ValueOf(byte(80)), + }) + if len(ret) != 7 { + t.Fatalf("Call returned %d values, want 7", len(ret)) + } + + i := byte(ret[0].Uint()) + j := int(ret[1].Int()) + k := byte(ret[2].Uint()) + l := ret[3].Interface().(two) + m := byte(ret[4].Uint()) + n := float32(ret[5].Float()) + o := byte(ret[6].Uint()) + + if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 { + t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o) + } +} + +type emptyStruct struct{} + +type nonEmptyStruct struct { + member int +} + +func returnEmpty() emptyStruct { + return emptyStruct{} +} + +func takesEmpty(e emptyStruct) { +} + +func returnNonEmpty(i int) nonEmptyStruct { + return nonEmptyStruct{member: i} +} + +func takesNonEmpty(n nonEmptyStruct) int { + return n.member +} + +func TestCallWithStruct(t *testing.T) { + r := ValueOf(returnEmpty).Call(nil) + if len(r) != 1 || r[0].Type() != TypeOf(emptyStruct{}) { + t.Errorf("returning empty struct returned %#v instead", r) + } + r = ValueOf(takesEmpty).Call([]Value{ValueOf(emptyStruct{})}) + if len(r) != 0 { + t.Errorf("takesEmpty returned values: %#v", r) + } + r = ValueOf(returnNonEmpty).Call([]Value{ValueOf(42)}) + if len(r) != 1 || r[0].Type() != TypeOf(nonEmptyStruct{}) || r[0].Field(0).Int() != 42 { + t.Errorf("returnNonEmpty returned %#v", r) + } + r = ValueOf(takesNonEmpty).Call([]Value{ValueOf(nonEmptyStruct{member: 42})}) + if len(r) != 1 || r[0].Type() != TypeOf(1) || r[0].Int() != 42 { + t.Errorf("takesNonEmpty returned %#v", r) + } +} + +func TestMakeFunc(t *testing.T) { + f := dummy + fv := MakeFunc(TypeOf(f), func(in []Value) []Value { return in }) + ValueOf(&f).Elem().Set(fv) + + // Call g with small arguments so that there is + // something predictable (and different from the + // correct results) in those positions on the stack. + g := dummy + g(1, 2, 3, two{4, 5}, 6, 7, 8) + + // Call constructed function f. + i, j, k, l, m, n, o := f(10, 20, 30, two{40, 50}, 60, 70, 80) + if i != 10 || j != 20 || k != 30 || l != (two{40, 50}) || m != 60 || n != 70 || o != 80 { + t.Errorf("Call returned %d, %d, %d, %v, %d, %g, %d; want 10, 20, 30, [40, 50], 60, 70, 80", i, j, k, l, m, n, o) + } +} + +func TestMakeFuncInterface(t *testing.T) { + fn := func(i int) int { return i } + incr := func(in []Value) []Value { + return []Value{ValueOf(int(in[0].Int() + 1))} + } + fv := MakeFunc(TypeOf(fn), incr) + ValueOf(&fn).Elem().Set(fv) + if r := fn(2); r != 3 { + t.Errorf("Call returned %d, want 3", r) + } + if r := fv.Call([]Value{ValueOf(14)})[0].Int(); r != 15 { + t.Errorf("Call returned %d, want 15", r) + } + if r := fv.Interface().(func(int) int)(26); r != 27 { + t.Errorf("Call returned %d, want 27", r) + } +} + +func TestMakeFuncVariadic(t *testing.T) { + // Test that variadic arguments are packed into a slice and passed as last arg + fn := func(_ int, is ...int) []int { return nil } + fv := MakeFunc(TypeOf(fn), func(in []Value) []Value { return in[1:2] }) + ValueOf(&fn).Elem().Set(fv) + + r := fn(1, 2, 3) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + r = fn(1, []int{2, 3}...) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + r = fv.Call([]Value{ValueOf(1), ValueOf(2), ValueOf(3)})[0].Interface().([]int) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + r = fv.CallSlice([]Value{ValueOf(1), ValueOf([]int{2, 3})})[0].Interface().([]int) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + + f := fv.Interface().(func(int, ...int) []int) + + r = f(1, 2, 3) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } + r = f(1, []int{2, 3}...) + if r[0] != 2 || r[1] != 3 { + t.Errorf("Call returned [%v, %v]; want 2, 3", r[0], r[1]) + } +} + +type Point struct { + x, y int +} + +// This will be index 0. +func (p Point) AnotherMethod(scale int) int { + return -1 +} + +// This will be index 1. +func (p Point) Dist(scale int) int { + //println("Point.Dist", p.x, p.y, scale) + return p.x*p.x*scale + p.y*p.y*scale +} + +// This will be index 2. +func (p Point) GCMethod(k int) int { + runtime.GC() + return k + p.x +} + +// This will be index 3. +func (p Point) TotalDist(points ...Point) int { + tot := 0 + for _, q := range points { + dx := q.x - p.x + dy := q.y - p.y + tot += dx*dx + dy*dy // Should call Sqrt, but it's just a test. + + } + return tot +} + +func TestMethod(t *testing.T) { + // Non-curried method of type. + p := Point{3, 4} + i := TypeOf(p).Method(1).Func.Call([]Value{ValueOf(p), ValueOf(10)})[0].Int() + if i != 250 { + t.Errorf("Type Method returned %d; want 250", i) + } + + m, ok := TypeOf(p).MethodByName("Dist") + if !ok { + t.Fatalf("method by name failed") + } + i = m.Func.Call([]Value{ValueOf(p), ValueOf(11)})[0].Int() + if i != 275 { + t.Errorf("Type MethodByName returned %d; want 275", i) + } + + i = TypeOf(&p).Method(1).Func.Call([]Value{ValueOf(&p), ValueOf(12)})[0].Int() + if i != 300 { + t.Errorf("Pointer Type Method returned %d; want 300", i) + } + + m, ok = TypeOf(&p).MethodByName("Dist") + if !ok { + t.Fatalf("ptr method by name failed") + } + i = m.Func.Call([]Value{ValueOf(&p), ValueOf(13)})[0].Int() + if i != 325 { + t.Errorf("Pointer Type MethodByName returned %d; want 325", i) + } + + // Curried method of value. + tfunc := TypeOf((func(int) int)(nil)) + v := ValueOf(p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Value Method Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(14)})[0].Int() + if i != 350 { + t.Errorf("Value Method returned %d; want 350", i) + } + v = ValueOf(p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(15)})[0].Int() + if i != 375 { + t.Errorf("Value MethodByName returned %d; want 375", i) + } + + // Curried method of pointer. + v = ValueOf(&p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(16)})[0].Int() + if i != 400 { + t.Errorf("Pointer Value Method returned %d; want 400", i) + } + v = ValueOf(&p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(17)})[0].Int() + if i != 425 { + t.Errorf("Pointer Value MethodByName returned %d; want 425", i) + } + + // Curried method of interface value. + // Have to wrap interface value in a struct to get at it. + // Passing it to ValueOf directly would + // access the underlying Point, not the interface. + var x interface { + Dist(int) int + } = p + pv := ValueOf(&x).Elem() + v = pv.Method(0) + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface Method Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(18)})[0].Int() + if i != 450 { + t.Errorf("Interface Method returned %d; want 450", i) + } + v = pv.MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc) + } + i = v.Call([]Value{ValueOf(19)})[0].Int() + if i != 475 { + t.Errorf("Interface MethodByName returned %d; want 475", i) + } +} + +func TestMethodValue(t *testing.T) { + p := Point{3, 4} + var i int64 + + // Curried method of value. + tfunc := TypeOf((func(int) int)(nil)) + v := ValueOf(p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Value Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(10)})[0].Int() + if i != 250 { + t.Errorf("Value Method returned %d; want 250", i) + } + v = ValueOf(p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(11)})[0].Int() + if i != 275 { + t.Errorf("Value MethodByName returned %d; want 275", i) + } + + // Curried method of pointer. + v = ValueOf(&p).Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(12)})[0].Int() + if i != 300 { + t.Errorf("Pointer Value Method returned %d; want 300", i) + } + v = ValueOf(&p).MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(13)})[0].Int() + if i != 325 { + t.Errorf("Pointer Value MethodByName returned %d; want 325", i) + } + + // Curried method of pointer to pointer. + pp := &p + v = ValueOf(&pp).Elem().Method(1) + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Pointer Value Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(14)})[0].Int() + if i != 350 { + t.Errorf("Pointer Pointer Value Method returned %d; want 350", i) + } + v = ValueOf(&pp).Elem().MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Pointer Pointer Value MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(15)})[0].Int() + if i != 375 { + t.Errorf("Pointer Pointer Value MethodByName returned %d; want 375", i) + } + + // Curried method of interface value. + // Have to wrap interface value in a struct to get at it. + // Passing it to ValueOf directly would + // access the underlying Point, not the interface. + var s = struct { + X interface { + Dist(int) int + } + }{p} + pv := ValueOf(s).Field(0) + v = pv.Method(0) + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface Method Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(16)})[0].Int() + if i != 400 { + t.Errorf("Interface Method returned %d; want 400", i) + } + v = pv.MethodByName("Dist") + if tt := v.Type(); tt != tfunc { + t.Errorf("Interface MethodByName Type is %s; want %s", tt, tfunc) + } + i = ValueOf(v.Interface()).Call([]Value{ValueOf(17)})[0].Int() + if i != 425 { + t.Errorf("Interface MethodByName returned %d; want 425", i) + } +} + +func TestVariadicMethodValue(t *testing.T) { + p := Point{3, 4} + points := []Point{{20, 21}, {22, 23}, {24, 25}} + want := int64(p.TotalDist(points[0], points[1], points[2])) + + // Curried method of value. + tfunc := TypeOf((func(...Point) int)(nil)) + v := ValueOf(p).Method(3) + if tt := v.Type(); tt != tfunc { + t.Errorf("Variadic Method Type is %s; want %s", tt, tfunc) + } + i := ValueOf(v.Interface()).Call([]Value{ValueOf(points[0]), ValueOf(points[1]), ValueOf(points[2])})[0].Int() + if i != want { + t.Errorf("Variadic Method returned %d; want %d", i, want) + } + i = ValueOf(v.Interface()).CallSlice([]Value{ValueOf(points)})[0].Int() + if i != want { + t.Errorf("Variadic Method CallSlice returned %d; want %d", i, want) + } + + f := v.Interface().(func(...Point) int) + i = int64(f(points[0], points[1], points[2])) + if i != want { + t.Errorf("Variadic Method Interface returned %d; want %d", i, want) + } + i = int64(f(points...)) + if i != want { + t.Errorf("Variadic Method Interface Slice returned %d; want %d", i, want) + } +} + +// Reflect version of $GOROOT/test/method5.go + +// Concrete types implementing M method. +// Smaller than a word, word-sized, larger than a word. +// Value and pointer receivers. + +type Tinter interface { + M(int, byte) (byte, int) +} + +type Tsmallv byte + +func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x + int(v) } + +type Tsmallp byte + +func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x + int(*p) } + +type Twordv uintptr + +func (v Twordv) M(x int, b byte) (byte, int) { return b, x + int(v) } + +type Twordp uintptr + +func (p *Twordp) M(x int, b byte) (byte, int) { return b, x + int(*p) } + +type Tbigv [2]uintptr + +func (v Tbigv) M(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) } + +type Tbigp [2]uintptr + +func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) } + +// Again, with an unexported method. + +type tsmallv byte + +func (v tsmallv) m(x int, b byte) (byte, int) { return b, x + int(v) } + +type tsmallp byte + +func (p *tsmallp) m(x int, b byte) (byte, int) { return b, x + int(*p) } + +type twordv uintptr + +func (v twordv) m(x int, b byte) (byte, int) { return b, x + int(v) } + +type twordp uintptr + +func (p *twordp) m(x int, b byte) (byte, int) { return b, x + int(*p) } + +type tbigv [2]uintptr + +func (v tbigv) m(x int, b byte) (byte, int) { return b, x + int(v[0]) + int(v[1]) } + +type tbigp [2]uintptr + +func (p *tbigp) m(x int, b byte) (byte, int) { return b, x + int(p[0]) + int(p[1]) } + +type tinter interface { + m(int, byte) (byte, int) +} + +// Embedding via pointer. + +type Tm1 struct { + Tm2 +} + +type Tm2 struct { + *Tm3 +} + +type Tm3 struct { + *Tm4 +} + +type Tm4 struct { +} + +func (t4 Tm4) M(x int, b byte) (byte, int) { return b, x + 40 } + +func TestMethod5(t *testing.T) { + CheckF := func(name string, f func(int, byte) (byte, int), inc int) { + b, x := f(1000, 99) + if b != 99 || x != 1000+inc { + t.Errorf("%s(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc) + } + } + + CheckV := func(name string, i Value, inc int) { + bx := i.Method(0).Call([]Value{ValueOf(1000), ValueOf(byte(99))}) + b := bx[0].Interface() + x := bx[1].Interface() + if b != byte(99) || x != 1000+inc { + t.Errorf("direct %s.M(1000, 99) = %v, %v, want 99, %v", name, b, x, 1000+inc) + } + + CheckF(name+".M", i.Method(0).Interface().(func(int, byte) (byte, int)), inc) + } + + var TinterType = TypeOf(new(Tinter)).Elem() + var tinterType = TypeOf(new(tinter)).Elem() + + CheckI := func(name string, i interface{}, inc int) { + v := ValueOf(i) + CheckV(name, v, inc) + CheckV("(i="+name+")", v.Convert(TinterType), inc) + } + + sv := Tsmallv(1) + CheckI("sv", sv, 1) + CheckI("&sv", &sv, 1) + + sp := Tsmallp(2) + CheckI("&sp", &sp, 2) + + wv := Twordv(3) + CheckI("wv", wv, 3) + CheckI("&wv", &wv, 3) + + wp := Twordp(4) + CheckI("&wp", &wp, 4) + + bv := Tbigv([2]uintptr{5, 6}) + CheckI("bv", bv, 11) + CheckI("&bv", &bv, 11) + + bp := Tbigp([2]uintptr{7, 8}) + CheckI("&bp", &bp, 15) + + t4 := Tm4{} + t3 := Tm3{&t4} + t2 := Tm2{&t3} + t1 := Tm1{t2} + CheckI("t4", t4, 40) + CheckI("&t4", &t4, 40) + CheckI("t3", t3, 40) + CheckI("&t3", &t3, 40) + CheckI("t2", t2, 40) + CheckI("&t2", &t2, 40) + CheckI("t1", t1, 40) + CheckI("&t1", &t1, 40) + + methodShouldPanic := func(name string, i interface{}) { + v := ValueOf(i) + m := v.Method(0) + shouldPanic(func() { m.Call([]Value{ValueOf(1000), ValueOf(byte(99))}) }) + shouldPanic(func() { m.Interface() }) + + v = v.Convert(tinterType) + m = v.Method(0) + shouldPanic(func() { m.Call([]Value{ValueOf(1000), ValueOf(byte(99))}) }) + shouldPanic(func() { m.Interface() }) + } + + _sv := tsmallv(1) + methodShouldPanic("_sv", _sv) + methodShouldPanic("&_sv", &_sv) + + _sp := tsmallp(2) + methodShouldPanic("&_sp", &_sp) + + _wv := twordv(3) + methodShouldPanic("_wv", _wv) + methodShouldPanic("&_wv", &_wv) + + _wp := twordp(4) + methodShouldPanic("&_wp", &_wp) + + _bv := tbigv([2]uintptr{5, 6}) + methodShouldPanic("_bv", _bv) + methodShouldPanic("&_bv", &_bv) + + _bp := tbigp([2]uintptr{7, 8}) + methodShouldPanic("&_bp", &_bp) + + var tnil Tinter + vnil := ValueOf(&tnil).Elem() + shouldPanic(func() { vnil.Method(0) }) +} + +func TestInterfaceSet(t *testing.T) { + p := &Point{3, 4} + + var s struct { + I interface{} + P interface { + Dist(int) int + } + } + sv := ValueOf(&s).Elem() + sv.Field(0).Set(ValueOf(p)) + if q := s.I.(*Point); q != p { + t.Errorf("i: have %p want %p", q, p) + } + + pv := sv.Field(1) + pv.Set(ValueOf(p)) + if q := s.P.(*Point); q != p { + t.Errorf("i: have %p want %p", q, p) + } + + i := pv.Method(0).Call([]Value{ValueOf(10)})[0].Int() + if i != 250 { + t.Errorf("Interface Method returned %d; want 250", i) + } +} + +type T1 struct { + a string + int +} + +func TestAnonymousFields(t *testing.T) { + var field StructField + var ok bool + var t1 T1 + type1 := TypeOf(t1) + if field, ok = type1.FieldByName("int"); !ok { + t.Fatal("no field 'int'") + } + if field.Index[0] != 1 { + t.Error("field index should be 1; is", field.Index) + } +} + +type FTest struct { + s interface{} + name string + index []int + value int +} + +type D1 struct { + d int +} +type D2 struct { + d int +} + +type S0 struct { + A, B, C int + D1 + D2 +} + +type S1 struct { + B int + S0 +} + +type S2 struct { + A int + *S1 +} + +type S1x struct { + S1 +} + +type S1y struct { + S1 +} + +type S3 struct { + S1x + S2 + D, E int + *S1y +} + +type S4 struct { + *S4 + A int +} + +// The X in S6 and S7 annihilate, but they also block the X in S8.S9. +type S5 struct { + S6 + S7 + S8 +} + +type S6 struct { + X int +} + +type S7 S6 + +type S8 struct { + S9 +} + +type S9 struct { + X int + Y int +} + +// The X in S11.S6 and S12.S6 annihilate, but they also block the X in S13.S8.S9. +type S10 struct { + S11 + S12 + S13 +} + +type S11 struct { + S6 +} + +type S12 struct { + S6 +} + +type S13 struct { + S8 +} + +// The X in S15.S11.S1 and S16.S11.S1 annihilate. +type S14 struct { + S15 + S16 +} + +type S15 struct { + S11 +} + +type S16 struct { + S11 +} + +var fieldTests = []FTest{ + {struct{}{}, "", nil, 0}, + {struct{}{}, "Foo", nil, 0}, + {S0{A: 'a'}, "A", []int{0}, 'a'}, + {S0{}, "D", nil, 0}, + {S1{S0: S0{A: 'a'}}, "A", []int{1, 0}, 'a'}, + {S1{B: 'b'}, "B", []int{0}, 'b'}, + {S1{}, "S0", []int{1}, 0}, + {S1{S0: S0{C: 'c'}}, "C", []int{1, 2}, 'c'}, + {S2{A: 'a'}, "A", []int{0}, 'a'}, + {S2{}, "S1", []int{1}, 0}, + {S2{S1: &S1{B: 'b'}}, "B", []int{1, 0}, 'b'}, + {S2{S1: &S1{S0: S0{C: 'c'}}}, "C", []int{1, 1, 2}, 'c'}, + {S2{}, "D", nil, 0}, + {S3{}, "S1", nil, 0}, + {S3{S2: S2{A: 'a'}}, "A", []int{1, 0}, 'a'}, + {S3{}, "B", nil, 0}, + {S3{D: 'd'}, "D", []int{2}, 0}, + {S3{E: 'e'}, "E", []int{3}, 'e'}, + {S4{A: 'a'}, "A", []int{1}, 'a'}, + {S4{}, "B", nil, 0}, + {S5{}, "X", nil, 0}, + {S5{}, "Y", []int{2, 0, 1}, 0}, + {S10{}, "X", nil, 0}, + {S10{}, "Y", []int{2, 0, 0, 1}, 0}, + {S14{}, "X", nil, 0}, +} + +func TestFieldByIndex(t *testing.T) { + for _, test := range fieldTests { + s := TypeOf(test.s) + f := s.FieldByIndex(test.index) + if f.Name != "" { + if test.index != nil { + if f.Name != test.name { + t.Errorf("%s.%s found; want %s", s.Name(), f.Name, test.name) + } + } else { + t.Errorf("%s.%s found", s.Name(), f.Name) + } + } else if len(test.index) > 0 { + t.Errorf("%s.%s not found", s.Name(), test.name) + } + + if test.value != 0 { + v := ValueOf(test.s).FieldByIndex(test.index) + if v.IsValid() { + if x, ok := v.Interface().(int); ok { + if x != test.value { + t.Errorf("%s%v is %d; want %d", s.Name(), test.index, x, test.value) + } + } else { + t.Errorf("%s%v value not an int", s.Name(), test.index) + } + } else { + t.Errorf("%s%v value not found", s.Name(), test.index) + } + } + } +} + +func TestFieldByName(t *testing.T) { + for _, test := range fieldTests { + s := TypeOf(test.s) + f, found := s.FieldByName(test.name) + if found { + if test.index != nil { + // Verify field depth and index. + if len(f.Index) != len(test.index) { + t.Errorf("%s.%s depth %d; want %d: %v vs %v", s.Name(), test.name, len(f.Index), len(test.index), f.Index, test.index) + } else { + for i, x := range f.Index { + if x != test.index[i] { + t.Errorf("%s.%s.Index[%d] is %d; want %d", s.Name(), test.name, i, x, test.index[i]) + } + } + } + } else { + t.Errorf("%s.%s found", s.Name(), f.Name) + } + } else if len(test.index) > 0 { + t.Errorf("%s.%s not found", s.Name(), test.name) + } + + if test.value != 0 { + v := ValueOf(test.s).FieldByName(test.name) + if v.IsValid() { + if x, ok := v.Interface().(int); ok { + if x != test.value { + t.Errorf("%s.%s is %d; want %d", s.Name(), test.name, x, test.value) + } + } else { + t.Errorf("%s.%s value not an int", s.Name(), test.name) + } + } else { + t.Errorf("%s.%s value not found", s.Name(), test.name) + } + } + } +} + +func TestImportPath(t *testing.T) { + tests := []struct { + t Type + path string + }{ + {TypeOf(&base64.Encoding{}).Elem(), "encoding/base64"}, + {TypeOf(int(0)), ""}, + {TypeOf(int8(0)), ""}, + {TypeOf(int16(0)), ""}, + {TypeOf(int32(0)), ""}, + {TypeOf(int64(0)), ""}, + {TypeOf(uint(0)), ""}, + {TypeOf(uint8(0)), ""}, + {TypeOf(uint16(0)), ""}, + {TypeOf(uint32(0)), ""}, + {TypeOf(uint64(0)), ""}, + {TypeOf(uintptr(0)), ""}, + {TypeOf(float32(0)), ""}, + {TypeOf(float64(0)), ""}, + {TypeOf(complex64(0)), ""}, + {TypeOf(complex128(0)), ""}, + {TypeOf(byte(0)), ""}, + {TypeOf(rune(0)), ""}, + {TypeOf([]byte(nil)), ""}, + {TypeOf([]rune(nil)), ""}, + {TypeOf(string("")), ""}, + {TypeOf((*interface{})(nil)).Elem(), ""}, + {TypeOf((*byte)(nil)), ""}, + {TypeOf((*rune)(nil)), ""}, + {TypeOf((*int64)(nil)), ""}, + {TypeOf(map[string]int{}), ""}, + {TypeOf((*error)(nil)).Elem(), ""}, + } + for _, test := range tests { + if path := test.t.PkgPath(); path != test.path { + t.Errorf("%v.PkgPath() = %q, want %q", test.t, path, test.path) + } + } +} + +func TestVariadicType(t *testing.T) { + // Test example from Type documentation. + var f func(x int, y ...float64) + typ := TypeOf(f) + if typ.NumIn() == 2 && typ.In(0) == TypeOf(int(0)) { + sl := typ.In(1) + if sl.Kind() == Slice { + if sl.Elem() == TypeOf(0.0) { + // ok + return + } + } + } + + // Failed + t.Errorf("want NumIn() = 2, In(0) = int, In(1) = []float64") + s := fmt.Sprintf("have NumIn() = %d", typ.NumIn()) + for i := 0; i < typ.NumIn(); i++ { + s += fmt.Sprintf(", In(%d) = %s", i, typ.In(i)) + } + t.Error(s) +} + +type inner struct { + x int +} + +type outer struct { + y int + inner +} + +func (*inner) m() {} +func (*outer) m() {} + +func TestNestedMethods(t *testing.T) { + typ := TypeOf((*outer)(nil)) + if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*outer).m).Pointer() { + t.Errorf("Wrong method table for outer: (m=%p)", (*outer).m) + for i := 0; i < typ.NumMethod(); i++ { + m := typ.Method(i) + t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer()) + } + } +} + +type InnerInt struct { + X int +} + +type OuterInt struct { + Y int + InnerInt +} + +func (i *InnerInt) M() int { + return i.X +} + +func TestEmbeddedMethods(t *testing.T) { + typ := TypeOf((*OuterInt)(nil)) + if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != ValueOf((*OuterInt).M).Pointer() { + t.Errorf("Wrong method table for OuterInt: (m=%p)", (*OuterInt).M) + for i := 0; i < typ.NumMethod(); i++ { + m := typ.Method(i) + t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer()) + } + } + + i := &InnerInt{3} + if v := ValueOf(i).Method(0).Call(nil)[0].Int(); v != 3 { + t.Errorf("i.M() = %d, want 3", v) + } + + o := &OuterInt{1, InnerInt{2}} + if v := ValueOf(o).Method(0).Call(nil)[0].Int(); v != 2 { + t.Errorf("i.M() = %d, want 2", v) + } + + f := (*OuterInt).M + if v := f(o); v != 2 { + t.Errorf("f(o) = %d, want 2", v) + } +} + +func TestPtrTo(t *testing.T) { + var i int + + typ := TypeOf(i) + for i = 0; i < 100; i++ { + typ = PtrTo(typ) + } + for i = 0; i < 100; i++ { + typ = typ.Elem() + } + if typ != TypeOf(i) { + t.Errorf("after 100 PtrTo and Elem, have %s, want %s", typ, TypeOf(i)) + } +} + +func TestPtrToGC(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + pt := PtrTo(tt) + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := New(pt) + p := new(*uintptr) + *p = new(uintptr) + **p = uintptr(i) + v.Elem().Set(ValueOf(p).Convert(pt)) + x = append(x, v.Interface()) + } + runtime.GC() + + for i, xi := range x { + k := ValueOf(xi).Elem().Elem().Elem().Interface().(uintptr) + if k != uintptr(i) { + t.Errorf("lost x[%d] = %d, want %d", i, k, i) + } + } +} + +func TestAddr(t *testing.T) { + var p struct { + X, Y int + } + + v := ValueOf(&p) + v = v.Elem() + v = v.Addr() + v = v.Elem() + v = v.Field(0) + v.SetInt(2) + if p.X != 2 { + t.Errorf("Addr.Elem.Set failed to set value") + } + + // Again but take address of the ValueOf value. + // Exercises generation of PtrTypes not present in the binary. + q := &p + v = ValueOf(&q).Elem() + v = v.Addr() + v = v.Elem() + v = v.Elem() + v = v.Addr() + v = v.Elem() + v = v.Field(0) + v.SetInt(3) + if p.X != 3 { + t.Errorf("Addr.Elem.Set failed to set value") + } + + // Starting without pointer we should get changed value + // in interface. + qq := p + v = ValueOf(&qq).Elem() + v0 := v + v = v.Addr() + v = v.Elem() + v = v.Field(0) + v.SetInt(4) + if p.X != 3 { // should be unchanged from last time + t.Errorf("somehow value Set changed original p") + } + p = v0.Interface().(struct { + X, Y int + }) + if p.X != 4 { + t.Errorf("Addr.Elem.Set valued to set value in top value") + } + + // Verify that taking the address of a type gives us a pointer + // which we can convert back using the usual interface + // notation. + var s struct { + B *bool + } + ps := ValueOf(&s).Elem().Field(0).Addr().Interface() + *(ps.(**bool)) = new(bool) + if s.B == nil { + t.Errorf("Addr.Interface direct assignment failed") + } +} + +func noAlloc(t *testing.T, n int, f func(int)) { + if testing.Short() { + t.Skip("skipping malloc count in short mode") + } + if runtime.GOMAXPROCS(0) > 1 { + t.Skip("skipping; GOMAXPROCS>1") + } + i := -1 + allocs := testing.AllocsPerRun(n, func() { + f(i) + i++ + }) + if allocs > 0 { + t.Errorf("%d iterations: got %v mallocs, want 0", n, allocs) + } +} + +func TestAllocations(t *testing.T) { + noAlloc(t, 100, func(j int) { + var i interface{} + var v Value + + // We can uncomment this when compiler escape analysis + // is good enough to see that the integer assigned to i + // does not escape and therefore need not be allocated. + // + // i = 42 + j + // v = ValueOf(i) + // if int(v.Int()) != 42+j { + // panic("wrong int") + // } + + i = func(j int) int { return j } + v = ValueOf(i) + if v.Interface().(func(int) int)(j) != j { + panic("wrong result") + } + }) +} + +func TestSmallNegativeInt(t *testing.T) { + i := int16(-1) + v := ValueOf(i) + if v.Int() != -1 { + t.Errorf("int16(-1).Int() returned %v", v.Int()) + } +} + +func TestIndex(t *testing.T) { + xs := []byte{1, 2, 3, 4, 5, 6, 7, 8} + v := ValueOf(xs).Index(3).Interface().(byte) + if v != xs[3] { + t.Errorf("xs.Index(3) = %v; expected %v", v, xs[3]) + } + xa := [8]byte{10, 20, 30, 40, 50, 60, 70, 80} + v = ValueOf(xa).Index(2).Interface().(byte) + if v != xa[2] { + t.Errorf("xa.Index(2) = %v; expected %v", v, xa[2]) + } + s := "0123456789" + v = ValueOf(s).Index(3).Interface().(byte) + if v != s[3] { + t.Errorf("s.Index(3) = %v; expected %v", v, s[3]) + } +} + +func TestSlice(t *testing.T) { + xs := []int{1, 2, 3, 4, 5, 6, 7, 8} + v := ValueOf(xs).Slice(3, 5).Interface().([]int) + if len(v) != 2 { + t.Errorf("len(xs.Slice(3, 5)) = %d", len(v)) + } + if cap(v) != 5 { + t.Errorf("cap(xs.Slice(3, 5)) = %d", cap(v)) + } + if !DeepEqual(v[0:5], xs[3:]) { + t.Errorf("xs.Slice(3, 5)[0:5] = %v", v[0:5]) + } + xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80} + v = ValueOf(&xa).Elem().Slice(2, 5).Interface().([]int) + if len(v) != 3 { + t.Errorf("len(xa.Slice(2, 5)) = %d", len(v)) + } + if cap(v) != 6 { + t.Errorf("cap(xa.Slice(2, 5)) = %d", cap(v)) + } + if !DeepEqual(v[0:6], xa[2:]) { + t.Errorf("xs.Slice(2, 5)[0:6] = %v", v[0:6]) + } + s := "0123456789" + vs := ValueOf(s).Slice(3, 5).Interface().(string) + if vs != s[3:5] { + t.Errorf("s.Slice(3, 5) = %q; expected %q", vs, s[3:5]) + } + + rv := ValueOf(&xs).Elem() + rv = rv.Slice(3, 4) + ptr2 := rv.Pointer() + rv = rv.Slice(5, 5) + ptr3 := rv.Pointer() + if ptr3 != ptr2 { + t.Errorf("xs.Slice(3,4).Slice3(5,5).Pointer() = %#x, want %#x", ptr3, ptr2) + } +} + +func TestSlice3(t *testing.T) { + xs := []int{1, 2, 3, 4, 5, 6, 7, 8} + v := ValueOf(xs).Slice3(3, 5, 7).Interface().([]int) + if len(v) != 2 { + t.Errorf("len(xs.Slice3(3, 5, 7)) = %d", len(v)) + } + if cap(v) != 4 { + t.Errorf("cap(xs.Slice3(3, 5, 7)) = %d", cap(v)) + } + if !DeepEqual(v[0:4], xs[3:7:7]) { + t.Errorf("xs.Slice3(3, 5, 7)[0:4] = %v", v[0:4]) + } + rv := ValueOf(&xs).Elem() + shouldPanic(func() { rv.Slice3(1, 2, 1) }) + shouldPanic(func() { rv.Slice3(1, 1, 11) }) + shouldPanic(func() { rv.Slice3(2, 2, 1) }) + + xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80} + v = ValueOf(&xa).Elem().Slice3(2, 5, 6).Interface().([]int) + if len(v) != 3 { + t.Errorf("len(xa.Slice(2, 5, 6)) = %d", len(v)) + } + if cap(v) != 4 { + t.Errorf("cap(xa.Slice(2, 5, 6)) = %d", cap(v)) + } + if !DeepEqual(v[0:4], xa[2:6:6]) { + t.Errorf("xs.Slice(2, 5, 6)[0:4] = %v", v[0:4]) + } + rv = ValueOf(&xa).Elem() + shouldPanic(func() { rv.Slice3(1, 2, 1) }) + shouldPanic(func() { rv.Slice3(1, 1, 11) }) + shouldPanic(func() { rv.Slice3(2, 2, 1) }) + + s := "hello world" + rv = ValueOf(&s).Elem() + shouldPanic(func() { rv.Slice3(1, 2, 3) }) + + rv = ValueOf(&xs).Elem() + rv = rv.Slice3(3, 5, 7) + ptr2 := rv.Pointer() + rv = rv.Slice3(4, 4, 4) + ptr3 := rv.Pointer() + if ptr3 != ptr2 { + t.Errorf("xs.Slice3(3,5,7).Slice3(4,4,4).Pointer() = %#x, want %#x", ptr3, ptr2) + } +} + +func TestSetLenCap(t *testing.T) { + xs := []int{1, 2, 3, 4, 5, 6, 7, 8} + xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80} + + vs := ValueOf(&xs).Elem() + shouldPanic(func() { vs.SetLen(10) }) + shouldPanic(func() { vs.SetCap(10) }) + shouldPanic(func() { vs.SetLen(-1) }) + shouldPanic(func() { vs.SetCap(-1) }) + shouldPanic(func() { vs.SetCap(6) }) // smaller than len + vs.SetLen(5) + if len(xs) != 5 || cap(xs) != 8 { + t.Errorf("after SetLen(5), len, cap = %d, %d, want 5, 8", len(xs), cap(xs)) + } + vs.SetCap(6) + if len(xs) != 5 || cap(xs) != 6 { + t.Errorf("after SetCap(6), len, cap = %d, %d, want 5, 6", len(xs), cap(xs)) + } + vs.SetCap(5) + if len(xs) != 5 || cap(xs) != 5 { + t.Errorf("after SetCap(5), len, cap = %d, %d, want 5, 5", len(xs), cap(xs)) + } + shouldPanic(func() { vs.SetCap(4) }) // smaller than len + shouldPanic(func() { vs.SetLen(6) }) // bigger than cap + + va := ValueOf(&xa).Elem() + shouldPanic(func() { va.SetLen(8) }) + shouldPanic(func() { va.SetCap(8) }) +} + +func TestVariadic(t *testing.T) { + var b bytes.Buffer + V := ValueOf + + b.Reset() + V(fmt.Fprintf).Call([]Value{V(&b), V("%s, %d world"), V("hello"), V(42)}) + if b.String() != "hello, 42 world" { + t.Errorf("after Fprintf Call: %q != %q", b.String(), "hello 42 world") + } + + b.Reset() + V(fmt.Fprintf).CallSlice([]Value{V(&b), V("%s, %d world"), V([]interface{}{"hello", 42})}) + if b.String() != "hello, 42 world" { + t.Errorf("after Fprintf CallSlice: %q != %q", b.String(), "hello 42 world") + } +} + +func TestFuncArg(t *testing.T) { + f1 := func(i int, f func(int) int) int { return f(i) } + f2 := func(i int) int { return i + 1 } + r := ValueOf(f1).Call([]Value{ValueOf(100), ValueOf(f2)}) + if r[0].Int() != 101 { + t.Errorf("function returned %d, want 101", r[0].Int()) + } +} + +func TestStructArg(t *testing.T) { + type padded struct { + B string + C int32 + } + var ( + gotA padded + gotB uint32 + wantA = padded{"3", 4} + wantB = uint32(5) + ) + f := func(a padded, b uint32) { + gotA, gotB = a, b + } + ValueOf(f).Call([]Value{ValueOf(wantA), ValueOf(wantB)}) + if gotA != wantA || gotB != wantB { + t.Errorf("function called with (%v, %v), want (%v, %v)", gotA, gotB, wantA, wantB) + } +} + +var tagGetTests = []struct { + Tag StructTag + Key string + Value string +}{ + {`protobuf:"PB(1,2)"`, `protobuf`, `PB(1,2)`}, + {`protobuf:"PB(1,2)"`, `foo`, ``}, + {`protobuf:"PB(1,2)"`, `rotobuf`, ``}, + {`protobuf:"PB(1,2)" json:"name"`, `json`, `name`}, + {`protobuf:"PB(1,2)" json:"name"`, `protobuf`, `PB(1,2)`}, +} + +func TestTagGet(t *testing.T) { + for _, tt := range tagGetTests { + if v := tt.Tag.Get(tt.Key); v != tt.Value { + t.Errorf("StructTag(%#q).Get(%#q) = %#q, want %#q", tt.Tag, tt.Key, v, tt.Value) + } + } +} + +func TestBytes(t *testing.T) { + type B []byte + x := B{1, 2, 3, 4} + y := ValueOf(x).Bytes() + if !bytes.Equal(x, y) { + t.Fatalf("ValueOf(%v).Bytes() = %v", x, y) + } + if &x[0] != &y[0] { + t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0]) + } +} + +func TestSetBytes(t *testing.T) { + type B []byte + var x B + y := []byte{1, 2, 3, 4} + ValueOf(&x).Elem().SetBytes(y) + if !bytes.Equal(x, y) { + t.Fatalf("ValueOf(%v).Bytes() = %v", x, y) + } + if &x[0] != &y[0] { + t.Errorf("ValueOf(%p).Bytes() = %p", &x[0], &y[0]) + } +} + +type Private struct { + x int + y **int +} + +func (p *Private) m() { +} + +type Public struct { + X int + Y **int +} + +func (p *Public) M() { +} + +func TestUnexported(t *testing.T) { + var pub Public + v := ValueOf(&pub) + isValid(v.Elem().Field(0)) + isValid(v.Elem().Field(1)) + isValid(v.Elem().FieldByName("X")) + isValid(v.Elem().FieldByName("Y")) + isValid(v.Type().Method(0).Func) + isNonNil(v.Elem().Field(0).Interface()) + isNonNil(v.Elem().Field(1).Interface()) + isNonNil(v.Elem().FieldByName("X").Interface()) + isNonNil(v.Elem().FieldByName("Y").Interface()) + isNonNil(v.Type().Method(0).Func.Interface()) + + var priv Private + v = ValueOf(&priv) + isValid(v.Elem().Field(0)) + isValid(v.Elem().Field(1)) + isValid(v.Elem().FieldByName("x")) + isValid(v.Elem().FieldByName("y")) + isValid(v.Type().Method(0).Func) + shouldPanic(func() { v.Elem().Field(0).Interface() }) + shouldPanic(func() { v.Elem().Field(1).Interface() }) + shouldPanic(func() { v.Elem().FieldByName("x").Interface() }) + shouldPanic(func() { v.Elem().FieldByName("y").Interface() }) + shouldPanic(func() { v.Type().Method(0).Func.Interface() }) +} + +func shouldPanic(f func()) { + defer func() { + if recover() == nil { + panic("did not panic") + } + }() + f() +} + +func isNonNil(x interface{}) { + if x == nil { + panic("nil interface") + } +} + +func isValid(v Value) { + if !v.IsValid() { + panic("zero Value") + } +} + +func TestAlias(t *testing.T) { + x := string("hello") + v := ValueOf(&x).Elem() + oldvalue := v.Interface() + v.SetString("world") + newvalue := v.Interface() + + if oldvalue != "hello" || newvalue != "world" { + t.Errorf("aliasing: old=%q new=%q, want hello, world", oldvalue, newvalue) + } +} + +var V = ValueOf + +func EmptyInterfaceV(x interface{}) Value { + return ValueOf(&x).Elem() +} + +func ReaderV(x io.Reader) Value { + return ValueOf(&x).Elem() +} + +func ReadWriterV(x io.ReadWriter) Value { + return ValueOf(&x).Elem() +} + +type Empty struct{} +type MyString string +type MyBytes []byte +type MyRunes []int32 +type MyFunc func() +type MyByte byte + +var convertTests = []struct { + in Value + out Value +}{ + // numbers + /* + Edit .+1,/\*\//-1>cat >/tmp/x.go && go run /tmp/x.go + + package main + + import "fmt" + + var numbers = []string{ + "int8", "uint8", "int16", "uint16", + "int32", "uint32", "int64", "uint64", + "int", "uint", "uintptr", + "float32", "float64", + } + + func main() { + // all pairs but in an unusual order, + // to emit all the int8, uint8 cases + // before n grows too big. + n := 1 + for i, f := range numbers { + for _, g := range numbers[i:] { + fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", f, n, g, n) + n++ + if f != g { + fmt.Printf("\t{V(%s(%d)), V(%s(%d))},\n", g, n, f, n) + n++ + } + } + } + } + */ + {V(int8(1)), V(int8(1))}, + {V(int8(2)), V(uint8(2))}, + {V(uint8(3)), V(int8(3))}, + {V(int8(4)), V(int16(4))}, + {V(int16(5)), V(int8(5))}, + {V(int8(6)), V(uint16(6))}, + {V(uint16(7)), V(int8(7))}, + {V(int8(8)), V(int32(8))}, + {V(int32(9)), V(int8(9))}, + {V(int8(10)), V(uint32(10))}, + {V(uint32(11)), V(int8(11))}, + {V(int8(12)), V(int64(12))}, + {V(int64(13)), V(int8(13))}, + {V(int8(14)), V(uint64(14))}, + {V(uint64(15)), V(int8(15))}, + {V(int8(16)), V(int(16))}, + {V(int(17)), V(int8(17))}, + {V(int8(18)), V(uint(18))}, + {V(uint(19)), V(int8(19))}, + {V(int8(20)), V(uintptr(20))}, + {V(uintptr(21)), V(int8(21))}, + {V(int8(22)), V(float32(22))}, + {V(float32(23)), V(int8(23))}, + {V(int8(24)), V(float64(24))}, + {V(float64(25)), V(int8(25))}, + {V(uint8(26)), V(uint8(26))}, + {V(uint8(27)), V(int16(27))}, + {V(int16(28)), V(uint8(28))}, + {V(uint8(29)), V(uint16(29))}, + {V(uint16(30)), V(uint8(30))}, + {V(uint8(31)), V(int32(31))}, + {V(int32(32)), V(uint8(32))}, + {V(uint8(33)), V(uint32(33))}, + {V(uint32(34)), V(uint8(34))}, + {V(uint8(35)), V(int64(35))}, + {V(int64(36)), V(uint8(36))}, + {V(uint8(37)), V(uint64(37))}, + {V(uint64(38)), V(uint8(38))}, + {V(uint8(39)), V(int(39))}, + {V(int(40)), V(uint8(40))}, + {V(uint8(41)), V(uint(41))}, + {V(uint(42)), V(uint8(42))}, + {V(uint8(43)), V(uintptr(43))}, + {V(uintptr(44)), V(uint8(44))}, + {V(uint8(45)), V(float32(45))}, + {V(float32(46)), V(uint8(46))}, + {V(uint8(47)), V(float64(47))}, + {V(float64(48)), V(uint8(48))}, + {V(int16(49)), V(int16(49))}, + {V(int16(50)), V(uint16(50))}, + {V(uint16(51)), V(int16(51))}, + {V(int16(52)), V(int32(52))}, + {V(int32(53)), V(int16(53))}, + {V(int16(54)), V(uint32(54))}, + {V(uint32(55)), V(int16(55))}, + {V(int16(56)), V(int64(56))}, + {V(int64(57)), V(int16(57))}, + {V(int16(58)), V(uint64(58))}, + {V(uint64(59)), V(int16(59))}, + {V(int16(60)), V(int(60))}, + {V(int(61)), V(int16(61))}, + {V(int16(62)), V(uint(62))}, + {V(uint(63)), V(int16(63))}, + {V(int16(64)), V(uintptr(64))}, + {V(uintptr(65)), V(int16(65))}, + {V(int16(66)), V(float32(66))}, + {V(float32(67)), V(int16(67))}, + {V(int16(68)), V(float64(68))}, + {V(float64(69)), V(int16(69))}, + {V(uint16(70)), V(uint16(70))}, + {V(uint16(71)), V(int32(71))}, + {V(int32(72)), V(uint16(72))}, + {V(uint16(73)), V(uint32(73))}, + {V(uint32(74)), V(uint16(74))}, + {V(uint16(75)), V(int64(75))}, + {V(int64(76)), V(uint16(76))}, + {V(uint16(77)), V(uint64(77))}, + {V(uint64(78)), V(uint16(78))}, + {V(uint16(79)), V(int(79))}, + {V(int(80)), V(uint16(80))}, + {V(uint16(81)), V(uint(81))}, + {V(uint(82)), V(uint16(82))}, + {V(uint16(83)), V(uintptr(83))}, + {V(uintptr(84)), V(uint16(84))}, + {V(uint16(85)), V(float32(85))}, + {V(float32(86)), V(uint16(86))}, + {V(uint16(87)), V(float64(87))}, + {V(float64(88)), V(uint16(88))}, + {V(int32(89)), V(int32(89))}, + {V(int32(90)), V(uint32(90))}, + {V(uint32(91)), V(int32(91))}, + {V(int32(92)), V(int64(92))}, + {V(int64(93)), V(int32(93))}, + {V(int32(94)), V(uint64(94))}, + {V(uint64(95)), V(int32(95))}, + {V(int32(96)), V(int(96))}, + {V(int(97)), V(int32(97))}, + {V(int32(98)), V(uint(98))}, + {V(uint(99)), V(int32(99))}, + {V(int32(100)), V(uintptr(100))}, + {V(uintptr(101)), V(int32(101))}, + {V(int32(102)), V(float32(102))}, + {V(float32(103)), V(int32(103))}, + {V(int32(104)), V(float64(104))}, + {V(float64(105)), V(int32(105))}, + {V(uint32(106)), V(uint32(106))}, + {V(uint32(107)), V(int64(107))}, + {V(int64(108)), V(uint32(108))}, + {V(uint32(109)), V(uint64(109))}, + {V(uint64(110)), V(uint32(110))}, + {V(uint32(111)), V(int(111))}, + {V(int(112)), V(uint32(112))}, + {V(uint32(113)), V(uint(113))}, + {V(uint(114)), V(uint32(114))}, + {V(uint32(115)), V(uintptr(115))}, + {V(uintptr(116)), V(uint32(116))}, + {V(uint32(117)), V(float32(117))}, + {V(float32(118)), V(uint32(118))}, + {V(uint32(119)), V(float64(119))}, + {V(float64(120)), V(uint32(120))}, + {V(int64(121)), V(int64(121))}, + {V(int64(122)), V(uint64(122))}, + {V(uint64(123)), V(int64(123))}, + {V(int64(124)), V(int(124))}, + {V(int(125)), V(int64(125))}, + {V(int64(126)), V(uint(126))}, + {V(uint(127)), V(int64(127))}, + {V(int64(128)), V(uintptr(128))}, + {V(uintptr(129)), V(int64(129))}, + {V(int64(130)), V(float32(130))}, + {V(float32(131)), V(int64(131))}, + {V(int64(132)), V(float64(132))}, + {V(float64(133)), V(int64(133))}, + {V(uint64(134)), V(uint64(134))}, + {V(uint64(135)), V(int(135))}, + {V(int(136)), V(uint64(136))}, + {V(uint64(137)), V(uint(137))}, + {V(uint(138)), V(uint64(138))}, + {V(uint64(139)), V(uintptr(139))}, + {V(uintptr(140)), V(uint64(140))}, + {V(uint64(141)), V(float32(141))}, + {V(float32(142)), V(uint64(142))}, + {V(uint64(143)), V(float64(143))}, + {V(float64(144)), V(uint64(144))}, + {V(int(145)), V(int(145))}, + {V(int(146)), V(uint(146))}, + {V(uint(147)), V(int(147))}, + {V(int(148)), V(uintptr(148))}, + {V(uintptr(149)), V(int(149))}, + {V(int(150)), V(float32(150))}, + {V(float32(151)), V(int(151))}, + {V(int(152)), V(float64(152))}, + {V(float64(153)), V(int(153))}, + {V(uint(154)), V(uint(154))}, + {V(uint(155)), V(uintptr(155))}, + {V(uintptr(156)), V(uint(156))}, + {V(uint(157)), V(float32(157))}, + {V(float32(158)), V(uint(158))}, + {V(uint(159)), V(float64(159))}, + {V(float64(160)), V(uint(160))}, + {V(uintptr(161)), V(uintptr(161))}, + {V(uintptr(162)), V(float32(162))}, + {V(float32(163)), V(uintptr(163))}, + {V(uintptr(164)), V(float64(164))}, + {V(float64(165)), V(uintptr(165))}, + {V(float32(166)), V(float32(166))}, + {V(float32(167)), V(float64(167))}, + {V(float64(168)), V(float32(168))}, + {V(float64(169)), V(float64(169))}, + + // truncation + {V(float64(1.5)), V(int(1))}, + + // complex + {V(complex64(1i)), V(complex64(1i))}, + {V(complex64(2i)), V(complex128(2i))}, + {V(complex128(3i)), V(complex64(3i))}, + {V(complex128(4i)), V(complex128(4i))}, + + // string + {V(string("hello")), V(string("hello"))}, + {V(string("bytes1")), V([]byte("bytes1"))}, + {V([]byte("bytes2")), V(string("bytes2"))}, + {V([]byte("bytes3")), V([]byte("bytes3"))}, + {V(string("runes♝")), V([]rune("runes♝"))}, + {V([]rune("runes♕")), V(string("runes♕"))}, + {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, + {V(int('a')), V(string("a"))}, + {V(int8('a')), V(string("a"))}, + {V(int16('a')), V(string("a"))}, + {V(int32('a')), V(string("a"))}, + {V(int64('a')), V(string("a"))}, + {V(uint('a')), V(string("a"))}, + {V(uint8('a')), V(string("a"))}, + {V(uint16('a')), V(string("a"))}, + {V(uint32('a')), V(string("a"))}, + {V(uint64('a')), V(string("a"))}, + {V(uintptr('a')), V(string("a"))}, + {V(int(-1)), V(string("\uFFFD"))}, + {V(int8(-2)), V(string("\uFFFD"))}, + {V(int16(-3)), V(string("\uFFFD"))}, + {V(int32(-4)), V(string("\uFFFD"))}, + {V(int64(-5)), V(string("\uFFFD"))}, + {V(uint(0x110001)), V(string("\uFFFD"))}, + {V(uint32(0x110002)), V(string("\uFFFD"))}, + {V(uint64(0x110003)), V(string("\uFFFD"))}, + {V(uintptr(0x110004)), V(string("\uFFFD"))}, + + // named string + {V(MyString("hello")), V(string("hello"))}, + {V(string("hello")), V(MyString("hello"))}, + {V(string("hello")), V(string("hello"))}, + {V(MyString("hello")), V(MyString("hello"))}, + {V(MyString("bytes1")), V([]byte("bytes1"))}, + {V([]byte("bytes2")), V(MyString("bytes2"))}, + {V([]byte("bytes3")), V([]byte("bytes3"))}, + {V(MyString("runes♝")), V([]rune("runes♝"))}, + {V([]rune("runes♕")), V(MyString("runes♕"))}, + {V([]rune("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, + {V([]rune("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))}, + {V(MyRunes("runes🙈🙉🙊")), V([]rune("runes🙈🙉🙊"))}, + {V(int('a')), V(MyString("a"))}, + {V(int8('a')), V(MyString("a"))}, + {V(int16('a')), V(MyString("a"))}, + {V(int32('a')), V(MyString("a"))}, + {V(int64('a')), V(MyString("a"))}, + {V(uint('a')), V(MyString("a"))}, + {V(uint8('a')), V(MyString("a"))}, + {V(uint16('a')), V(MyString("a"))}, + {V(uint32('a')), V(MyString("a"))}, + {V(uint64('a')), V(MyString("a"))}, + {V(uintptr('a')), V(MyString("a"))}, + {V(int(-1)), V(MyString("\uFFFD"))}, + {V(int8(-2)), V(MyString("\uFFFD"))}, + {V(int16(-3)), V(MyString("\uFFFD"))}, + {V(int32(-4)), V(MyString("\uFFFD"))}, + {V(int64(-5)), V(MyString("\uFFFD"))}, + {V(uint(0x110001)), V(MyString("\uFFFD"))}, + {V(uint32(0x110002)), V(MyString("\uFFFD"))}, + {V(uint64(0x110003)), V(MyString("\uFFFD"))}, + {V(uintptr(0x110004)), V(MyString("\uFFFD"))}, + + // named []byte + {V(string("bytes1")), V(MyBytes("bytes1"))}, + {V(MyBytes("bytes2")), V(string("bytes2"))}, + {V(MyBytes("bytes3")), V(MyBytes("bytes3"))}, + {V(MyString("bytes1")), V(MyBytes("bytes1"))}, + {V(MyBytes("bytes2")), V(MyString("bytes2"))}, + + // named []rune + {V(string("runes♝")), V(MyRunes("runes♝"))}, + {V(MyRunes("runes♕")), V(string("runes♕"))}, + {V(MyRunes("runes🙈🙉🙊")), V(MyRunes("runes🙈🙉🙊"))}, + {V(MyString("runes♝")), V(MyRunes("runes♝"))}, + {V(MyRunes("runes♕")), V(MyString("runes♕"))}, + + // named types and equal underlying types + {V(new(int)), V(new(integer))}, + {V(new(integer)), V(new(int))}, + {V(Empty{}), V(struct{}{})}, + {V(new(Empty)), V(new(struct{}))}, + {V(struct{}{}), V(Empty{})}, + {V(new(struct{})), V(new(Empty))}, + {V(Empty{}), V(Empty{})}, + {V(MyBytes{}), V([]byte{})}, + {V([]byte{}), V(MyBytes{})}, + {V((func())(nil)), V(MyFunc(nil))}, + {V((MyFunc)(nil)), V((func())(nil))}, + + // can convert *byte and *MyByte + {V((*byte)(nil)), V((*MyByte)(nil))}, + {V((*MyByte)(nil)), V((*byte)(nil))}, + + // cannot convert mismatched array sizes + {V([2]byte{}), V([2]byte{})}, + {V([3]byte{}), V([3]byte{})}, + + // cannot convert other instances + {V((**byte)(nil)), V((**byte)(nil))}, + {V((**MyByte)(nil)), V((**MyByte)(nil))}, + {V((chan byte)(nil)), V((chan byte)(nil))}, + {V((chan MyByte)(nil)), V((chan MyByte)(nil))}, + {V(([]byte)(nil)), V(([]byte)(nil))}, + {V(([]MyByte)(nil)), V(([]MyByte)(nil))}, + {V((map[int]byte)(nil)), V((map[int]byte)(nil))}, + {V((map[int]MyByte)(nil)), V((map[int]MyByte)(nil))}, + {V((map[byte]int)(nil)), V((map[byte]int)(nil))}, + {V((map[MyByte]int)(nil)), V((map[MyByte]int)(nil))}, + {V([2]byte{}), V([2]byte{})}, + {V([2]MyByte{}), V([2]MyByte{})}, + + // other + {V((***int)(nil)), V((***int)(nil))}, + {V((***byte)(nil)), V((***byte)(nil))}, + {V((***int32)(nil)), V((***int32)(nil))}, + {V((***int64)(nil)), V((***int64)(nil))}, + {V((chan int)(nil)), V((<-chan int)(nil))}, + {V((chan int)(nil)), V((chan<- int)(nil))}, + {V((chan string)(nil)), V((<-chan string)(nil))}, + {V((chan string)(nil)), V((chan<- string)(nil))}, + {V((chan byte)(nil)), V((chan byte)(nil))}, + {V((chan MyByte)(nil)), V((chan MyByte)(nil))}, + {V((map[int]bool)(nil)), V((map[int]bool)(nil))}, + {V((map[int]byte)(nil)), V((map[int]byte)(nil))}, + {V((map[uint]bool)(nil)), V((map[uint]bool)(nil))}, + {V([]uint(nil)), V([]uint(nil))}, + {V([]int(nil)), V([]int(nil))}, + {V(new(interface{})), V(new(interface{}))}, + {V(new(io.Reader)), V(new(io.Reader))}, + {V(new(io.Writer)), V(new(io.Writer))}, + + // interfaces + {V(int(1)), EmptyInterfaceV(int(1))}, + {V(string("hello")), EmptyInterfaceV(string("hello"))}, + {V(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))}, + {ReadWriterV(new(bytes.Buffer)), ReaderV(new(bytes.Buffer))}, + {V(new(bytes.Buffer)), ReadWriterV(new(bytes.Buffer))}, +} + +func TestConvert(t *testing.T) { + canConvert := map[[2]Type]bool{} + all := map[Type]bool{} + + for _, tt := range convertTests { + t1 := tt.in.Type() + if !t1.ConvertibleTo(t1) { + t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t1) + continue + } + + t2 := tt.out.Type() + if !t1.ConvertibleTo(t2) { + t.Errorf("(%s).ConvertibleTo(%s) = false, want true", t1, t2) + continue + } + + all[t1] = true + all[t2] = true + canConvert[[2]Type{t1, t2}] = true + + // vout1 represents the in value converted to the in type. + v1 := tt.in + vout1 := v1.Convert(t1) + out1 := vout1.Interface() + if vout1.Type() != tt.in.Type() || !DeepEqual(out1, tt.in.Interface()) { + t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t1, out1, tt.in.Interface()) + } + + // vout2 represents the in value converted to the out type. + vout2 := v1.Convert(t2) + out2 := vout2.Interface() + if vout2.Type() != tt.out.Type() || !DeepEqual(out2, tt.out.Interface()) { + t.Errorf("ValueOf(%T(%[1]v)).Convert(%s) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out2, tt.out.Interface()) + } + + // vout3 represents a new value of the out type, set to vout2. This makes + // sure the converted value vout2 is really usable as a regular value. + vout3 := New(t2).Elem() + vout3.Set(vout2) + out3 := vout3.Interface() + if vout3.Type() != tt.out.Type() || !DeepEqual(out3, tt.out.Interface()) { + t.Errorf("Set(ValueOf(%T(%[1]v)).Convert(%s)) = %T(%[3]v), want %T(%[4]v)", tt.in.Interface(), t2, out3, tt.out.Interface()) + } + + if IsRO(v1) { + t.Errorf("table entry %v is RO, should not be", v1) + } + if IsRO(vout1) { + t.Errorf("self-conversion output %v is RO, should not be", vout1) + } + if IsRO(vout2) { + t.Errorf("conversion output %v is RO, should not be", vout2) + } + if IsRO(vout3) { + t.Errorf("set(conversion output) %v is RO, should not be", vout3) + } + if !IsRO(MakeRO(v1).Convert(t1)) { + t.Errorf("RO self-conversion output %v is not RO, should be", v1) + } + if !IsRO(MakeRO(v1).Convert(t2)) { + t.Errorf("RO conversion output %v is not RO, should be", v1) + } + } + + // Assume that of all the types we saw during the tests, + // if there wasn't an explicit entry for a conversion between + // a pair of types, then it's not to be allowed. This checks for + // things like 'int64' converting to '*int'. + for t1 := range all { + for t2 := range all { + expectOK := t1 == t2 || canConvert[[2]Type{t1, t2}] || t2.Kind() == Interface && t2.NumMethod() == 0 + if ok := t1.ConvertibleTo(t2); ok != expectOK { + t.Errorf("(%s).ConvertibleTo(%s) = %v, want %v", t1, t2, ok, expectOK) + } + } + } +} + +type ComparableStruct struct { + X int +} + +type NonComparableStruct struct { + X int + Y map[string]int +} + +var comparableTests = []struct { + typ Type + ok bool +}{ + {TypeOf(1), true}, + {TypeOf("hello"), true}, + {TypeOf(new(byte)), true}, + {TypeOf((func())(nil)), false}, + {TypeOf([]byte{}), false}, + {TypeOf(map[string]int{}), false}, + {TypeOf(make(chan int)), true}, + {TypeOf(1.5), true}, + {TypeOf(false), true}, + {TypeOf(1i), true}, + {TypeOf(ComparableStruct{}), true}, + {TypeOf(NonComparableStruct{}), false}, + {TypeOf([10]map[string]int{}), false}, + {TypeOf([10]string{}), true}, + {TypeOf(new(interface{})).Elem(), true}, +} + +func TestComparable(t *testing.T) { + for _, tt := range comparableTests { + if ok := tt.typ.Comparable(); ok != tt.ok { + t.Errorf("TypeOf(%v).Comparable() = %v, want %v", tt.typ, ok, tt.ok) + } + } +} + +func TestOverflow(t *testing.T) { + if ovf := V(float64(0)).OverflowFloat(1e300); ovf { + t.Errorf("%v wrongly overflows float64", 1e300) + } + + maxFloat32 := float64((1<<24 - 1) << (127 - 23)) + if ovf := V(float32(0)).OverflowFloat(maxFloat32); ovf { + t.Errorf("%v wrongly overflows float32", maxFloat32) + } + ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52)) + if ovf := V(float32(0)).OverflowFloat(ovfFloat32); !ovf { + t.Errorf("%v should overflow float32", ovfFloat32) + } + if ovf := V(float32(0)).OverflowFloat(-ovfFloat32); !ovf { + t.Errorf("%v should overflow float32", -ovfFloat32) + } + + maxInt32 := int64(0x7fffffff) + if ovf := V(int32(0)).OverflowInt(maxInt32); ovf { + t.Errorf("%v wrongly overflows int32", maxInt32) + } + if ovf := V(int32(0)).OverflowInt(-1 << 31); ovf { + t.Errorf("%v wrongly overflows int32", -int64(1)<<31) + } + ovfInt32 := int64(1 << 31) + if ovf := V(int32(0)).OverflowInt(ovfInt32); !ovf { + t.Errorf("%v should overflow int32", ovfInt32) + } + + maxUint32 := uint64(0xffffffff) + if ovf := V(uint32(0)).OverflowUint(maxUint32); ovf { + t.Errorf("%v wrongly overflows uint32", maxUint32) + } + ovfUint32 := uint64(1 << 32) + if ovf := V(uint32(0)).OverflowUint(ovfUint32); !ovf { + t.Errorf("%v should overflow uint32", ovfUint32) + } +} + +func checkSameType(t *testing.T, x, y interface{}) { + if TypeOf(x) != TypeOf(y) { + t.Errorf("did not find preexisting type for %s (vs %s)", TypeOf(x), TypeOf(y)) + } +} + +func TestArrayOf(t *testing.T) { + // TODO(rsc): Finish ArrayOf and enable-test. + t.Skip("ArrayOf is not finished (and not exported)") + + // check construction and use of type not in binary + type T int + at := ArrayOf(10, TypeOf(T(1))) + v := New(at).Elem() + for i := 0; i < v.Len(); i++ { + v.Index(i).Set(ValueOf(T(i))) + } + s := fmt.Sprint(v.Interface()) + want := "[0 1 2 3 4 5 6 7 8 9]" + if s != want { + t.Errorf("constructed array = %s, want %s", s, want) + } + + // check that type already in binary is found + checkSameType(t, Zero(ArrayOf(5, TypeOf(T(1)))).Interface(), [5]T{}) +} + +func TestSliceOf(t *testing.T) { + // check construction and use of type not in binary + type T int + st := SliceOf(TypeOf(T(1))) + v := MakeSlice(st, 10, 10) + runtime.GC() + for i := 0; i < v.Len(); i++ { + v.Index(i).Set(ValueOf(T(i))) + runtime.GC() + } + s := fmt.Sprint(v.Interface()) + want := "[0 1 2 3 4 5 6 7 8 9]" + if s != want { + t.Errorf("constructed slice = %s, want %s", s, want) + } + + // check that type already in binary is found + type T1 int + checkSameType(t, Zero(SliceOf(TypeOf(T1(1)))).Interface(), []T1{}) +} + +func TestSliceOverflow(t *testing.T) { + // check that MakeSlice panics when size of slice overflows uint + const S = 1e6 + s := uint(S) + l := (1<<(unsafe.Sizeof((*byte)(nil))*8)-1)/s + 1 + if l*s >= s { + t.Fatal("slice size does not overflow") + } + var x [S]byte + st := SliceOf(TypeOf(x)) + defer func() { + err := recover() + if err == nil { + t.Fatal("slice overflow does not panic") + } + }() + MakeSlice(st, int(l), int(l)) +} + +func TestSliceOfGC(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + st := SliceOf(tt) + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeSlice(st, n, n) + for j := 0; j < v.Len(); j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.Index(j).Set(ValueOf(p).Convert(tt)) + } + x = append(x, v.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi) + for j := 0; j < v.Len(); j++ { + k := v.Index(j).Elem().Interface() + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestChanOf(t *testing.T) { + // check construction and use of type not in binary + type T string + ct := ChanOf(BothDir, TypeOf(T(""))) + v := MakeChan(ct, 2) + runtime.GC() + v.Send(ValueOf(T("hello"))) + runtime.GC() + v.Send(ValueOf(T("world"))) + runtime.GC() + + sv1, _ := v.Recv() + sv2, _ := v.Recv() + s1 := sv1.String() + s2 := sv2.String() + if s1 != "hello" || s2 != "world" { + t.Errorf("constructed chan: have %q, %q, want %q, %q", s1, s2, "hello", "world") + } + + // check that type already in binary is found + type T1 int + checkSameType(t, Zero(ChanOf(BothDir, TypeOf(T1(1)))).Interface(), (chan T1)(nil)) +} + +func TestChanOfGC(t *testing.T) { + done := make(chan bool, 1) + go func() { + select { + case <-done: + case <-time.After(5 * time.Second): + panic("deadlock in TestChanOfGC") + } + }() + + defer func() { + done <- true + }() + + type T *uintptr + tt := TypeOf(T(nil)) + ct := ChanOf(BothDir, tt) + + // NOTE: The garbage collector handles allocated channels specially, + // so we have to save pointers to channels in x; the pointer code will + // use the gc info in the newly constructed chan type. + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeChan(ct, n) + for j := 0; j < n; j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.Send(ValueOf(p).Convert(tt)) + } + pv := New(ct) + pv.Elem().Set(v) + x = append(x, pv.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi).Elem() + for j := 0; j < n; j++ { + pv, _ := v.Recv() + k := pv.Elem().Interface() + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestMapOf(t *testing.T) { + // check construction and use of type not in binary + type K string + type V float64 + + v := MakeMap(MapOf(TypeOf(K("")), TypeOf(V(0)))) + runtime.GC() + v.SetMapIndex(ValueOf(K("a")), ValueOf(V(1))) + runtime.GC() + + s := fmt.Sprint(v.Interface()) + want := "map[a:1]" + if s != want { + t.Errorf("constructed map = %s, want %s", s, want) + } + + // check that type already in binary is found + checkSameType(t, Zero(MapOf(TypeOf(V(0)), TypeOf(K("")))).Interface(), map[V]K(nil)) + + // check that invalid key type panics + shouldPanic(func() { MapOf(TypeOf((func())(nil)), TypeOf(false)) }) +} + +func TestMapOfGCKeys(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + mt := MapOf(tt, TypeOf(false)) + + // NOTE: The garbage collector handles allocated maps specially, + // so we have to save pointers to maps in x; the pointer code will + // use the gc info in the newly constructed map type. + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeMap(mt) + for j := 0; j < n; j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.SetMapIndex(ValueOf(p).Convert(tt), ValueOf(true)) + } + pv := New(mt) + pv.Elem().Set(v) + x = append(x, pv.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi).Elem() + var out []int + for _, kv := range v.MapKeys() { + out = append(out, int(kv.Elem().Interface().(uintptr))) + } + sort.Ints(out) + for j, k := range out { + if k != i*n+j { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +func TestMapOfGCValues(t *testing.T) { + type T *uintptr + tt := TypeOf(T(nil)) + mt := MapOf(TypeOf(1), tt) + + // NOTE: The garbage collector handles allocated maps specially, + // so we have to save pointers to maps in x; the pointer code will + // use the gc info in the newly constructed map type. + const n = 100 + var x []interface{} + for i := 0; i < n; i++ { + v := MakeMap(mt) + for j := 0; j < n; j++ { + p := new(uintptr) + *p = uintptr(i*n + j) + v.SetMapIndex(ValueOf(j), ValueOf(p).Convert(tt)) + } + pv := New(mt) + pv.Elem().Set(v) + x = append(x, pv.Interface()) + } + runtime.GC() + + for i, xi := range x { + v := ValueOf(xi).Elem() + for j := 0; j < n; j++ { + k := v.MapIndex(ValueOf(j)).Elem().Interface().(uintptr) + if k != uintptr(i*n+j) { + t.Errorf("lost x[%d][%d] = %d, want %d", i, j, k, i*n+j) + } + } + } +} + +type B1 struct { + X int + Y int + Z int +} + +func BenchmarkFieldByName1(b *testing.B) { + t := TypeOf(B1{}) + for i := 0; i < b.N; i++ { + t.FieldByName("Z") + } +} + +func BenchmarkFieldByName2(b *testing.B) { + t := TypeOf(S3{}) + for i := 0; i < b.N; i++ { + t.FieldByName("B") + } +} + +type R0 struct { + *R1 + *R2 + *R3 + *R4 +} + +type R1 struct { + *R5 + *R6 + *R7 + *R8 +} + +type R2 R1 +type R3 R1 +type R4 R1 + +type R5 struct { + *R9 + *R10 + *R11 + *R12 +} + +type R6 R5 +type R7 R5 +type R8 R5 + +type R9 struct { + *R13 + *R14 + *R15 + *R16 +} + +type R10 R9 +type R11 R9 +type R12 R9 + +type R13 struct { + *R17 + *R18 + *R19 + *R20 +} + +type R14 R13 +type R15 R13 +type R16 R13 + +type R17 struct { + *R21 + *R22 + *R23 + *R24 +} + +type R18 R17 +type R19 R17 +type R20 R17 + +type R21 struct { + X int +} + +type R22 R21 +type R23 R21 +type R24 R21 + +func TestEmbed(t *testing.T) { + typ := TypeOf(R0{}) + f, ok := typ.FieldByName("X") + if ok { + t.Fatalf(`FieldByName("X") should fail, returned %v`, f.Index) + } +} + +func BenchmarkFieldByName3(b *testing.B) { + t := TypeOf(R0{}) + for i := 0; i < b.N; i++ { + t.FieldByName("X") + } +} + +type S struct { + i1 int64 + i2 int64 +} + +func BenchmarkInterfaceBig(b *testing.B) { + v := ValueOf(S{}) + for i := 0; i < b.N; i++ { + v.Interface() + } + b.StopTimer() +} + +func TestAllocsInterfaceBig(t *testing.T) { + if testing.Short() { + t.Skip("skipping malloc count in short mode") + } + v := ValueOf(S{}) + if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 { + t.Error("allocs:", allocs) + } +} + +func BenchmarkInterfaceSmall(b *testing.B) { + v := ValueOf(int64(0)) + for i := 0; i < b.N; i++ { + v.Interface() + } +} + +func TestAllocsInterfaceSmall(t *testing.T) { + if testing.Short() { + t.Skip("skipping malloc count in short mode") + } + v := ValueOf(int64(0)) + if allocs := testing.AllocsPerRun(100, func() { v.Interface() }); allocs > 0 { + t.Error("allocs:", allocs) + } +} + +// An exhaustive is a mechanism for writing exhaustive or stochastic tests. +// The basic usage is: +// +// for x.Next() { +// ... code using x.Maybe() or x.Choice(n) to create test cases ... +// } +// +// Each iteration of the loop returns a different set of results, until all +// possible result sets have been explored. It is okay for different code paths +// to make different method call sequences on x, but there must be no +// other source of non-determinism in the call sequences. +// +// When faced with a new decision, x chooses randomly. Future explorations +// of that path will choose successive values for the result. Thus, stopping +// the loop after a fixed number of iterations gives somewhat stochastic +// testing. +// +// Example: +// +// for x.Next() { +// v := make([]bool, x.Choose(4)) +// for i := range v { +// v[i] = x.Maybe() +// } +// fmt.Println(v) +// } +// +// prints (in some order): +// +// [] +// [false] +// [true] +// [false false] +// [false true] +// ... +// [true true] +// [false false false] +// ... +// [true true true] +// [false false false false] +// ... +// [true true true true] +// +type exhaustive struct { + r *rand.Rand + pos int + last []choice +} + +type choice struct { + off int + n int + max int +} + +func (x *exhaustive) Next() bool { + if x.r == nil { + x.r = rand.New(rand.NewSource(time.Now().UnixNano())) + } + x.pos = 0 + if x.last == nil { + x.last = []choice{} + return true + } + for i := len(x.last) - 1; i >= 0; i-- { + c := &x.last[i] + if c.n+1 < c.max { + c.n++ + x.last = x.last[:i+1] + return true + } + } + return false +} + +func (x *exhaustive) Choose(max int) int { + if x.pos >= len(x.last) { + x.last = append(x.last, choice{x.r.Intn(max), 0, max}) + } + c := &x.last[x.pos] + x.pos++ + if c.max != max { + panic("inconsistent use of exhaustive tester") + } + return (c.n + c.off) % max +} + +func (x *exhaustive) Maybe() bool { + return x.Choose(2) == 1 +} + +func GCFunc(args []Value) []Value { + runtime.GC() + return []Value{} +} + +func TestReflectFuncTraceback(t *testing.T) { + f := MakeFunc(TypeOf(func() {}), GCFunc) + f.Call([]Value{}) +} + +func TestReflectMethodTraceback(t *testing.T) { + p := Point{3, 4} + m := ValueOf(p).MethodByName("GCMethod") + i := ValueOf(m.Interface()).Call([]Value{ValueOf(5)})[0].Int() + if i != 8 { + t.Errorf("Call returned %d; want 8", i) + } +} + +func TestBigZero(t *testing.T) { + const size = 1 << 10 + var v [size]byte + z := Zero(ValueOf(v).Type()).Interface().([size]byte) + for i := 0; i < size; i++ { + if z[i] != 0 { + t.Fatalf("Zero object not all zero, index %d", i) + } + } +} + +func TestFieldByIndexNil(t *testing.T) { + type P struct { + F int + } + type T struct { + *P + } + v := ValueOf(T{}) + + v.FieldByName("P") // should be fine + + defer func() { + if err := recover(); err == nil { + t.Fatalf("no error") + } else if !strings.Contains(fmt.Sprint(err), "nil pointer to embedded struct") { + t.Fatalf(`err=%q, wanted error containing "nil pointer to embedded struct"`, err) + } + }() + v.FieldByName("F") // should panic + + t.Fatalf("did not panic") +} + +// Given +// type Outer struct { +// *Inner +// ... +// } +// the compiler generates the implementation of (*Outer).M dispatching to the embedded Inner. +// The implementation is logically: +// func (p *Outer) M() { +// (p.Inner).M() +// } +// but since the only change here is the replacement of one pointer receiver with another, +// the actual generated code overwrites the original receiver with the p.Inner pointer and +// then jumps to the M method expecting the *Inner receiver. +// +// During reflect.Value.Call, we create an argument frame and the associated data structures +// to describe it to the garbage collector, populate the frame, call reflect.call to +// run a function call using that frame, and then copy the results back out of the frame. +// The reflect.call function does a memmove of the frame structure onto the +// stack (to set up the inputs), runs the call, and the memmoves the stack back to +// the frame structure (to preserve the outputs). +// +// Originally reflect.call did not distinguish inputs from outputs: both memmoves +// were for the full stack frame. However, in the case where the called function was +// one of these wrappers, the rewritten receiver is almost certainly a different type +// than the original receiver. This is not a problem on the stack, where we use the +// program counter to determine the type information and understand that +// during (*Outer).M the receiver is an *Outer while during (*Inner).M the receiver in the same +// memory word is now an *Inner. But in the statically typed argument frame created +// by reflect, the receiver is always an *Outer. Copying the modified receiver pointer +// off the stack into the frame will store an *Inner there, and then if a garbage collection +// happens to scan that argument frame before it is discarded, it will scan the *Inner +// memory as if it were an *Outer. If the two have different memory layouts, the +// collection will intepret the memory incorrectly. +// +// One such possible incorrect interpretation is to treat two arbitrary memory words +// (Inner.P1 and Inner.P2 below) as an interface (Outer.R below). Because interpreting +// an interface requires dereferencing the itab word, the misinterpretation will try to +// deference Inner.P1, causing a crash during garbage collection. +// +// This came up in a real program in issue 7725. + +type Outer struct { + *Inner + R io.Reader +} + +type Inner struct { + X *Outer + P1 uintptr + P2 uintptr +} + +func (pi *Inner) M() { + // Clear references to pi so that the only way the + // garbage collection will find the pointer is in the + // argument frame, typed as a *Outer. + pi.X.Inner = nil + + // Set up an interface value that will cause a crash. + // P1 = 1 is a non-zero, so the interface looks non-nil. + // P2 = pi ensures that the data word points into the + // allocated heap; if not the collection skips the interface + // value as irrelevant, without dereferencing P1. + pi.P1 = 1 + pi.P2 = uintptr(unsafe.Pointer(pi)) +} + +func TestCallMethodJump(t *testing.T) { + // In reflect.Value.Call, trigger a garbage collection after reflect.call + // returns but before the args frame has been discarded. + // This is a little clumsy but makes the failure repeatable. + *CallGC = true + + p := &Outer{Inner: new(Inner)} + p.Inner.X = p + ValueOf(p).Method(0).Call(nil) + + // Stop garbage collecting during reflect.call. + *CallGC = false +} + +func TestMakeFuncStackCopy(t *testing.T) { + target := func(in []Value) []Value { + runtime.GC() + useStack(16) + return []Value{ValueOf(9)} + } + + var concrete func(*int, int) int + fn := MakeFunc(ValueOf(concrete).Type(), target) + ValueOf(&concrete).Elem().Set(fn) + x := concrete(nil, 7) + if x != 9 { + t.Errorf("have %#q want 9", x) + } +} + +// use about n KB of stack +func useStack(n int) { + if n == 0 { + return + } + var b [1024]byte // makes frame about 1KB + useStack(n - 1 + int(b[99])) +} + +type Impl struct{} + +func (Impl) f() {} + +func TestValueString(t *testing.T) { + rv := ValueOf(Impl{}) + if rv.String() != "<reflect_test.Impl Value>" { + t.Errorf("ValueOf(Impl{}).String() = %q, want %q", rv.String(), "<reflect_test.Impl Value>") + } + + method := rv.Method(0) + if method.String() != "<func() Value>" { + t.Errorf("ValueOf(Impl{}).Method(0).String() = %q, want %q", method.String(), "<func() Value>") + } +} + +func TestInvalid(t *testing.T) { + // Used to have inconsistency between IsValid() and Kind() != Invalid. + type T struct{ v interface{} } + + v := ValueOf(T{}).Field(0) + if v.IsValid() != true || v.Kind() != Interface { + t.Errorf("field: IsValid=%v, Kind=%v, want true, Interface", v.IsValid(), v.Kind()) + } + v = v.Elem() + if v.IsValid() != false || v.Kind() != Invalid { + t.Errorf("field elem: IsValid=%v, Kind=%v, want false, Invalid", v.IsValid(), v.Kind()) + } +} + +// Issue 8917. +func TestLargeGCProg(t *testing.T) { + fv := ValueOf(func([256]*byte) {}) + fv.Call([]Value{ValueOf([256]*byte{})}) +} + +// Issue 9179. +func TestCallGC(t *testing.T) { + f := func(a, b, c, d, e string) { + } + g := func(in []Value) []Value { + runtime.GC() + return nil + } + typ := ValueOf(f).Type() + f2 := MakeFunc(typ, g).Interface().(func(string, string, string, string, string)) + f2("four", "five5", "six666", "seven77", "eight888") +} + +type funcLayoutTest struct { + rcvr, t Type + argsize, retOffset uintptr + stack []byte +} + +var funcLayoutTests []funcLayoutTest + +func init() { + var argAlign = PtrSize + if runtime.GOARCH == "amd64p32" { + argAlign = 2 * PtrSize + } + roundup := func(x uintptr, a uintptr) uintptr { + return (x + a - 1) / a * a + } + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a, b string) string { return "" }).Type(), + 4 * PtrSize, + 4 * PtrSize, + []byte{BitsPointer, BitsScalar, BitsPointer}, + }) + + var r []byte + if PtrSize == 4 { + r = []byte{BitsScalar, BitsScalar, BitsScalar, BitsPointer} + } else { + r = []byte{BitsScalar, BitsScalar, BitsPointer} + } + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a, b, c uint32, p *byte, d uint16) {}).Type(), + roundup(3*4, PtrSize) + PtrSize + 2, + roundup(roundup(3*4, PtrSize)+PtrSize+2, argAlign), + r, + }) + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a map[int]int, b uintptr, c interface{}) {}).Type(), + 4 * PtrSize, + 4 * PtrSize, + []byte{BitsPointer, BitsScalar, BitsPointer, BitsPointer}, + }) + + type S struct { + a, b uintptr + c, d *byte + } + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + nil, + ValueOf(func(a S) {}).Type(), + 4 * PtrSize, + 4 * PtrSize, + []byte{BitsScalar, BitsScalar, BitsPointer, BitsPointer}, + }) + + funcLayoutTests = append(funcLayoutTests, + funcLayoutTest{ + ValueOf((*byte)(nil)).Type(), + ValueOf(func(a uintptr, b *int) {}).Type(), + 3 * PtrSize, + roundup(3*PtrSize, argAlign), + []byte{BitsPointer, BitsScalar, BitsPointer}, + }) +} + +func TestFuncLayout(t *testing.T) { + for _, lt := range funcLayoutTests { + _, argsize, retOffset, stack := FuncLayout(lt.t, lt.rcvr) + if argsize != lt.argsize { + t.Errorf("funcLayout(%v, %v).argsize=%d, want %d", lt.t, lt.rcvr, argsize, lt.argsize) + } + if retOffset != lt.retOffset { + t.Errorf("funcLayout(%v, %v).retOffset=%d, want %d", lt.t, lt.rcvr, retOffset, lt.retOffset) + } + if !bytes.Equal(stack, lt.stack) { + t.Errorf("funcLayout(%v, %v).stack=%v, want %v", lt.t, lt.rcvr, stack, lt.stack) + } + } +} diff --git a/src/reflect/asm_386.s b/src/reflect/asm_386.s new file mode 100644 index 000000000..0ffccf7d4 --- /dev/null +++ b/src/reflect/asm_386.s @@ -0,0 +1,30 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$8 + NO_LOCAL_POINTERS + MOVL DX, 0(SP) + LEAL argframe+0(FP), CX + MOVL CX, 4(SP) + CALL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$8 + NO_LOCAL_POINTERS + MOVL DX, 0(SP) + LEAL argframe+0(FP), CX + MOVL CX, 4(SP) + CALL ·callMethod(SB) + RET diff --git a/src/reflect/asm_amd64.s b/src/reflect/asm_amd64.s new file mode 100644 index 000000000..5a6c27ac9 --- /dev/null +++ b/src/reflect/asm_amd64.s @@ -0,0 +1,30 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVQ DX, 0(SP) + LEAQ argframe+0(FP), CX + MOVQ CX, 8(SP) + CALL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No arg size here; runtime pulls arg map out of the func value. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$16 + NO_LOCAL_POINTERS + MOVQ DX, 0(SP) + LEAQ argframe+0(FP), CX + MOVQ CX, 8(SP) + CALL ·callMethod(SB) + RET diff --git a/src/reflect/asm_amd64p32.s b/src/reflect/asm_amd64p32.s new file mode 100644 index 000000000..0ffccf7d4 --- /dev/null +++ b/src/reflect/asm_amd64p32.s @@ -0,0 +1,30 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is the code half of the function returned by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$8 + NO_LOCAL_POINTERS + MOVL DX, 0(SP) + LEAL argframe+0(FP), CX + MOVL CX, 4(SP) + CALL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$8 + NO_LOCAL_POINTERS + MOVL DX, 0(SP) + LEAL argframe+0(FP), CX + MOVL CX, 4(SP) + CALL ·callMethod(SB) + RET diff --git a/src/reflect/asm_arm.s b/src/reflect/asm_arm.s new file mode 100644 index 000000000..5a14c6f81 --- /dev/null +++ b/src/reflect/asm_arm.s @@ -0,0 +1,30 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" +#include "funcdata.h" + +// makeFuncStub is jumped to by the code generated by MakeFunc. +// See the comment on the declaration of makeFuncStub in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$8 + NO_LOCAL_POINTERS + MOVW R7, 4(R13) + MOVW $argframe+0(FP), R1 + MOVW R1, 8(R13) + BL ·callReflect(SB) + RET + +// methodValueCall is the code half of the function returned by makeMethodValue. +// See the comment on the declaration of methodValueCall in makefunc.go +// for more details. +// No argsize here, gc generates argsize info at call site. +TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$8 + NO_LOCAL_POINTERS + MOVW R7, 4(R13) + MOVW $argframe+0(FP), R1 + MOVW R1, 8(R13) + BL ·callMethod(SB) + RET diff --git a/src/reflect/deepequal.go b/src/reflect/deepequal.go new file mode 100644 index 000000000..f63715c9a --- /dev/null +++ b/src/reflect/deepequal.go @@ -0,0 +1,145 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Deep equality test via reflection + +package reflect + +// During deepValueEqual, must keep track of checks that are +// in progress. The comparison algorithm assumes that all +// checks in progress are true when it reencounters them. +// Visited comparisons are stored in a map indexed by visit. +type visit struct { + a1 uintptr + a2 uintptr + typ Type +} + +// Tests for deep equality using reflected types. The map argument tracks +// comparisons that have already been seen, which allows short circuiting on +// recursive types. +func deepValueEqual(v1, v2 Value, visited map[visit]bool, depth int) bool { + if !v1.IsValid() || !v2.IsValid() { + return v1.IsValid() == v2.IsValid() + } + if v1.Type() != v2.Type() { + return false + } + + // if depth > 10 { panic("deepValueEqual") } // for debugging + hard := func(k Kind) bool { + switch k { + case Array, Map, Slice, Struct: + return true + } + return false + } + + if v1.CanAddr() && v2.CanAddr() && hard(v1.Kind()) { + addr1 := v1.UnsafeAddr() + addr2 := v2.UnsafeAddr() + if addr1 > addr2 { + // Canonicalize order to reduce number of entries in visited. + addr1, addr2 = addr2, addr1 + } + + // Short circuit if references are identical ... + if addr1 == addr2 { + return true + } + + // ... or already seen + typ := v1.Type() + v := visit{addr1, addr2, typ} + if visited[v] { + return true + } + + // Remember for later. + visited[v] = true + } + + switch v1.Kind() { + case Array: + for i := 0; i < v1.Len(); i++ { + if !deepValueEqual(v1.Index(i), v2.Index(i), visited, depth+1) { + return false + } + } + return true + case Slice: + if v1.IsNil() != v2.IsNil() { + return false + } + if v1.Len() != v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for i := 0; i < v1.Len(); i++ { + if !deepValueEqual(v1.Index(i), v2.Index(i), visited, depth+1) { + return false + } + } + return true + case Interface: + if v1.IsNil() || v2.IsNil() { + return v1.IsNil() == v2.IsNil() + } + return deepValueEqual(v1.Elem(), v2.Elem(), visited, depth+1) + case Ptr: + return deepValueEqual(v1.Elem(), v2.Elem(), visited, depth+1) + case Struct: + for i, n := 0, v1.NumField(); i < n; i++ { + if !deepValueEqual(v1.Field(i), v2.Field(i), visited, depth+1) { + return false + } + } + return true + case Map: + if v1.IsNil() != v2.IsNil() { + return false + } + if v1.Len() != v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for _, k := range v1.MapKeys() { + if !deepValueEqual(v1.MapIndex(k), v2.MapIndex(k), visited, depth+1) { + return false + } + } + return true + case Func: + if v1.IsNil() && v2.IsNil() { + return true + } + // Can't do better than this: + return false + default: + // Normal equality suffices + return valueInterface(v1, false) == valueInterface(v2, false) + } +} + +// DeepEqual tests for deep equality. It uses normal == equality where +// possible but will scan elements of arrays, slices, maps, and fields of +// structs. In maps, keys are compared with == but elements use deep +// equality. DeepEqual correctly handles recursive types. Functions are equal +// only if they are both nil. +// An empty slice is not equal to a nil slice. +func DeepEqual(a1, a2 interface{}) bool { + if a1 == nil || a2 == nil { + return a1 == a2 + } + v1 := ValueOf(a1) + v2 := ValueOf(a2) + if v1.Type() != v2.Type() { + return false + } + return deepValueEqual(v1, v2, make(map[visit]bool), 0) +} diff --git a/src/reflect/example_test.go b/src/reflect/example_test.go new file mode 100644 index 000000000..cca28eeec --- /dev/null +++ b/src/reflect/example_test.go @@ -0,0 +1,66 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package reflect_test + +import ( + "fmt" + "reflect" +) + +func ExampleMakeFunc() { + // swap is the implementation passed to MakeFunc. + // It must work in terms of reflect.Values so that it is possible + // to write code without knowing beforehand what the types + // will be. + swap := func(in []reflect.Value) []reflect.Value { + return []reflect.Value{in[1], in[0]} + } + + // makeSwap expects fptr to be a pointer to a nil function. + // It sets that pointer to a new function created with MakeFunc. + // When the function is invoked, reflect turns the arguments + // into Values, calls swap, and then turns swap's result slice + // into the values returned by the new function. + makeSwap := func(fptr interface{}) { + // fptr is a pointer to a function. + // Obtain the function value itself (likely nil) as a reflect.Value + // so that we can query its type and then set the value. + fn := reflect.ValueOf(fptr).Elem() + + // Make a function of the right type. + v := reflect.MakeFunc(fn.Type(), swap) + + // Assign it to the value fn represents. + fn.Set(v) + } + + // Make and call a swap function for ints. + var intSwap func(int, int) (int, int) + makeSwap(&intSwap) + fmt.Println(intSwap(0, 1)) + + // Make and call a swap function for float64s. + var floatSwap func(float64, float64) (float64, float64) + makeSwap(&floatSwap) + fmt.Println(floatSwap(2.72, 3.14)) + + // Output: + // 1 0 + // 3.14 2.72 +} + +func ExampleStructTag() { + type S struct { + F string `species:"gopher" color:"blue"` + } + + s := S{} + st := reflect.TypeOf(s) + field := st.Field(0) + fmt.Println(field.Tag.Get("color"), field.Tag.Get("species")) + + // Output: + // blue gopher +} diff --git a/src/reflect/export_test.go b/src/reflect/export_test.go new file mode 100644 index 000000000..caaf51a50 --- /dev/null +++ b/src/reflect/export_test.go @@ -0,0 +1,38 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package reflect + +// MakeRO returns a copy of v with the read-only flag set. +func MakeRO(v Value) Value { + v.flag |= flagRO + return v +} + +// IsRO reports whether v's read-only flag is set. +func IsRO(v Value) bool { + return v.flag&flagRO != 0 +} + +var ArrayOf = arrayOf +var CallGC = &callGC + +const PtrSize = ptrSize +const BitsPointer = bitsPointer +const BitsScalar = bitsScalar + +func FuncLayout(t Type, rcvr Type) (frametype Type, argSize, retOffset uintptr, stack []byte) { + var ft *rtype + var s *bitVector + if rcvr != nil { + ft, argSize, retOffset, s = funcLayout(t.(*rtype), rcvr.(*rtype)) + } else { + ft, argSize, retOffset, s = funcLayout(t.(*rtype), nil) + } + frametype = ft + for i := uint32(0); i < s.n; i += 2 { + stack = append(stack, s.data[i/8]>>(i%8)&3) + } + return +} diff --git a/src/reflect/makefunc.go b/src/reflect/makefunc.go new file mode 100644 index 000000000..d89f7f681 --- /dev/null +++ b/src/reflect/makefunc.go @@ -0,0 +1,129 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// MakeFunc implementation. + +package reflect + +import ( + "unsafe" +) + +// makeFuncImpl is the closure value implementing the function +// returned by MakeFunc. +type makeFuncImpl struct { + code uintptr + stack *bitVector // stack bitmap for args - offset known to runtime + typ *funcType + fn func([]Value) []Value +} + +// MakeFunc returns a new function of the given Type +// that wraps the function fn. When called, that new function +// does the following: +// +// - converts its arguments to a slice of Values. +// - runs results := fn(args). +// - returns the results as a slice of Values, one per formal result. +// +// The implementation fn can assume that the argument Value slice +// has the number and type of arguments given by typ. +// If typ describes a variadic function, the final Value is itself +// a slice representing the variadic arguments, as in the +// body of a variadic function. The result Value slice returned by fn +// must have the number and type of results given by typ. +// +// The Value.Call method allows the caller to invoke a typed function +// in terms of Values; in contrast, MakeFunc allows the caller to implement +// a typed function in terms of Values. +// +// The Examples section of the documentation includes an illustration +// of how to use MakeFunc to build a swap function for different types. +// +func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value { + if typ.Kind() != Func { + panic("reflect: call of MakeFunc with non-Func type") + } + + t := typ.common() + ftyp := (*funcType)(unsafe.Pointer(t)) + + // Indirect Go func value (dummy) to obtain + // actual code address. (A Go func value is a pointer + // to a C function pointer. http://golang.org/s/go11func.) + dummy := makeFuncStub + code := **(**uintptr)(unsafe.Pointer(&dummy)) + + // makeFuncImpl contains a stack map for use by the runtime + _, _, _, stack := funcLayout(t, nil) + + impl := &makeFuncImpl{code: code, stack: stack, typ: ftyp, fn: fn} + + return Value{t, unsafe.Pointer(impl), flag(Func)} +} + +// makeFuncStub is an assembly function that is the code half of +// the function returned from MakeFunc. It expects a *callReflectFunc +// as its context register, and its job is to invoke callReflect(ctxt, frame) +// where ctxt is the context register and frame is a pointer to the first +// word in the passed-in argument frame. +func makeFuncStub() + +type methodValue struct { + fn uintptr + stack *bitVector // stack bitmap for args - offset known to runtime + method int + rcvr Value +} + +// makeMethodValue converts v from the rcvr+method index representation +// of a method value to an actual method func value, which is +// basically the receiver value with a special bit set, into a true +// func value - a value holding an actual func. The output is +// semantically equivalent to the input as far as the user of package +// reflect can tell, but the true func representation can be handled +// by code like Convert and Interface and Assign. +func makeMethodValue(op string, v Value) Value { + if v.flag&flagMethod == 0 { + panic("reflect: internal error: invalid use of makeMethodValue") + } + + // Ignoring the flagMethod bit, v describes the receiver, not the method type. + fl := v.flag & (flagRO | flagAddr | flagIndir) + fl |= flag(v.typ.Kind()) + rcvr := Value{v.typ, v.ptr, fl} + + // v.Type returns the actual type of the method value. + funcType := v.Type().(*rtype) + + // Indirect Go func value (dummy) to obtain + // actual code address. (A Go func value is a pointer + // to a C function pointer. http://golang.org/s/go11func.) + dummy := methodValueCall + code := **(**uintptr)(unsafe.Pointer(&dummy)) + + // methodValue contains a stack map for use by the runtime + _, _, _, stack := funcLayout(funcType, nil) + + fv := &methodValue{ + fn: code, + stack: stack, + method: int(v.flag) >> flagMethodShift, + rcvr: rcvr, + } + + // Cause panic if method is not appropriate. + // The panic would still happen during the call if we omit this, + // but we want Interface() and other operations to fail early. + methodReceiver(op, fv.rcvr, fv.method) + + return Value{funcType, unsafe.Pointer(fv), v.flag&flagRO | flag(Func)} +} + +// methodValueCall is an assembly function that is the code half of +// the function returned from makeMethodValue. It expects a *methodValue +// as its context register, and its job is to invoke callMethod(ctxt, frame) +// where ctxt is the context register and frame is a pointer to the first +// word in the passed-in argument frame. +func methodValueCall() diff --git a/src/reflect/set_test.go b/src/reflect/set_test.go new file mode 100644 index 000000000..85dc55e68 --- /dev/null +++ b/src/reflect/set_test.go @@ -0,0 +1,211 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package reflect_test + +import ( + "bytes" + "go/ast" + "io" + . "reflect" + "testing" + "unsafe" +) + +type MyBuffer bytes.Buffer + +func TestImplicitMapConversion(t *testing.T) { + // Test implicit conversions in MapIndex and SetMapIndex. + { + // direct + m := make(map[int]int) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#1 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#1 MapIndex(1) = %d", n) + } + } + { + // convert interface key + m := make(map[interface{}]int) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#2 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#2 MapIndex(1) = %d", n) + } + } + { + // convert interface value + m := make(map[int]interface{}) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#3 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#3 MapIndex(1) = %d", n) + } + } + { + // convert both interface key and interface value + m := make(map[interface{}]interface{}) + mv := ValueOf(m) + mv.SetMapIndex(ValueOf(1), ValueOf(2)) + x, ok := m[1] + if x != 2 { + t.Errorf("#4 after SetMapIndex(1,2): %d, %t (map=%v)", x, ok, m) + } + if n := mv.MapIndex(ValueOf(1)).Interface().(int); n != 2 { + t.Errorf("#4 MapIndex(1) = %d", n) + } + } + { + // convert both, with non-empty interfaces + m := make(map[io.Reader]io.Writer) + mv := ValueOf(m) + b1 := new(bytes.Buffer) + b2 := new(bytes.Buffer) + mv.SetMapIndex(ValueOf(b1), ValueOf(b2)) + x, ok := m[b1] + if x != b2 { + t.Errorf("#5 after SetMapIndex(b1, b2): %p (!= %p), %t (map=%v)", x, b2, ok, m) + } + if p := mv.MapIndex(ValueOf(b1)).Elem().Pointer(); p != uintptr(unsafe.Pointer(b2)) { + t.Errorf("#5 MapIndex(b1) = %#x want %p", p, b2) + } + } + { + // convert channel direction + m := make(map[<-chan int]chan int) + mv := ValueOf(m) + c1 := make(chan int) + c2 := make(chan int) + mv.SetMapIndex(ValueOf(c1), ValueOf(c2)) + x, ok := m[c1] + if x != c2 { + t.Errorf("#6 after SetMapIndex(c1, c2): %p (!= %p), %t (map=%v)", x, c2, ok, m) + } + if p := mv.MapIndex(ValueOf(c1)).Pointer(); p != ValueOf(c2).Pointer() { + t.Errorf("#6 MapIndex(c1) = %#x want %p", p, c2) + } + } + { + // convert identical underlying types + // TODO(rsc): Should be able to define MyBuffer here. + // 6l prints very strange messages about .this.Bytes etc + // when we do that though, so MyBuffer is defined + // at top level. + m := make(map[*MyBuffer]*bytes.Buffer) + mv := ValueOf(m) + b1 := new(MyBuffer) + b2 := new(bytes.Buffer) + mv.SetMapIndex(ValueOf(b1), ValueOf(b2)) + x, ok := m[b1] + if x != b2 { + t.Errorf("#7 after SetMapIndex(b1, b2): %p (!= %p), %t (map=%v)", x, b2, ok, m) + } + if p := mv.MapIndex(ValueOf(b1)).Pointer(); p != uintptr(unsafe.Pointer(b2)) { + t.Errorf("#7 MapIndex(b1) = %#x want %p", p, b2) + } + } + +} + +func TestImplicitSetConversion(t *testing.T) { + // Assume TestImplicitMapConversion covered the basics. + // Just make sure conversions are being applied at all. + var r io.Reader + b := new(bytes.Buffer) + rv := ValueOf(&r).Elem() + rv.Set(ValueOf(b)) + if r != b { + t.Errorf("after Set: r=%T(%v)", r, r) + } +} + +func TestImplicitSendConversion(t *testing.T) { + c := make(chan io.Reader, 10) + b := new(bytes.Buffer) + ValueOf(c).Send(ValueOf(b)) + if bb := <-c; bb != b { + t.Errorf("Received %p != %p", bb, b) + } +} + +func TestImplicitCallConversion(t *testing.T) { + // Arguments must be assignable to parameter types. + fv := ValueOf(io.WriteString) + b := new(bytes.Buffer) + fv.Call([]Value{ValueOf(b), ValueOf("hello world")}) + if b.String() != "hello world" { + t.Errorf("After call: string=%q want %q", b.String(), "hello world") + } +} + +func TestImplicitAppendConversion(t *testing.T) { + // Arguments must be assignable to the slice's element type. + s := []io.Reader{} + sv := ValueOf(&s).Elem() + b := new(bytes.Buffer) + sv.Set(Append(sv, ValueOf(b))) + if len(s) != 1 || s[0] != b { + t.Errorf("after append: s=%v want [%p]", s, b) + } +} + +var implementsTests = []struct { + x interface{} + t interface{} + b bool +}{ + {new(*bytes.Buffer), new(io.Reader), true}, + {new(bytes.Buffer), new(io.Reader), false}, + {new(*bytes.Buffer), new(io.ReaderAt), false}, + {new(*ast.Ident), new(ast.Expr), true}, +} + +func TestImplements(t *testing.T) { + for _, tt := range implementsTests { + xv := TypeOf(tt.x).Elem() + xt := TypeOf(tt.t).Elem() + if b := xv.Implements(xt); b != tt.b { + t.Errorf("(%s).Implements(%s) = %v, want %v", xv.String(), xt.String(), b, tt.b) + } + } +} + +var assignableTests = []struct { + x interface{} + t interface{} + b bool +}{ + {new(chan int), new(<-chan int), true}, + {new(<-chan int), new(chan int), false}, + {new(*int), new(IntPtr), true}, + {new(IntPtr), new(*int), true}, + {new(IntPtr), new(IntPtr1), false}, + // test runs implementsTests too +} + +type IntPtr *int +type IntPtr1 *int + +func TestAssignableTo(t *testing.T) { + for _, tt := range append(assignableTests, implementsTests...) { + xv := TypeOf(tt.x).Elem() + xt := TypeOf(tt.t).Elem() + if b := xv.AssignableTo(xt); b != tt.b { + t.Errorf("(%s).AssignableTo(%s) = %v, want %v", xv.String(), xt.String(), b, tt.b) + } + } +} diff --git a/src/reflect/tostring_test.go b/src/reflect/tostring_test.go new file mode 100644 index 000000000..e416fd84d --- /dev/null +++ b/src/reflect/tostring_test.go @@ -0,0 +1,95 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Formatting of reflection types and values for debugging. +// Not defined as methods so they do not need to be linked into most binaries; +// the functions are not used by the library itself, only in tests. + +package reflect_test + +import ( + . "reflect" + "strconv" +) + +// valueToString returns a textual representation of the reflection value val. +// For debugging only. +func valueToString(val Value) string { + var str string + if !val.IsValid() { + return "<zero Value>" + } + typ := val.Type() + switch val.Kind() { + case Int, Int8, Int16, Int32, Int64: + return strconv.FormatInt(val.Int(), 10) + case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return strconv.FormatUint(val.Uint(), 10) + case Float32, Float64: + return strconv.FormatFloat(val.Float(), 'g', -1, 64) + case Complex64, Complex128: + c := val.Complex() + return strconv.FormatFloat(real(c), 'g', -1, 64) + "+" + strconv.FormatFloat(imag(c), 'g', -1, 64) + "i" + case String: + return val.String() + case Bool: + if val.Bool() { + return "true" + } else { + return "false" + } + case Ptr: + v := val + str = typ.String() + "(" + if v.IsNil() { + str += "0" + } else { + str += "&" + valueToString(v.Elem()) + } + str += ")" + return str + case Array, Slice: + v := val + str += typ.String() + str += "{" + for i := 0; i < v.Len(); i++ { + if i > 0 { + str += ", " + } + str += valueToString(v.Index(i)) + } + str += "}" + return str + case Map: + t := typ + str = t.String() + str += "{" + str += "<can't iterate on maps>" + str += "}" + return str + case Chan: + str = typ.String() + return str + case Struct: + t := typ + v := val + str += t.String() + str += "{" + for i, n := 0, v.NumField(); i < n; i++ { + if i > 0 { + str += ", " + } + str += valueToString(v.Field(i)) + } + str += "}" + return str + case Interface: + return typ.String() + "(" + valueToString(val.Elem()) + ")" + case Func: + v := val + return typ.String() + "(" + strconv.FormatUint(uint64(v.Pointer()), 10) + ")" + default: + panic("valueToString: can't print type " + typ.String()) + } +} diff --git a/src/reflect/type.go b/src/reflect/type.go new file mode 100644 index 000000000..c0ddfcad0 --- /dev/null +++ b/src/reflect/type.go @@ -0,0 +1,1929 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package reflect implements run-time reflection, allowing a program to +// manipulate objects with arbitrary types. The typical use is to take a value +// with static type interface{} and extract its dynamic type information by +// calling TypeOf, which returns a Type. +// +// A call to ValueOf returns a Value representing the run-time data. +// Zero takes a Type and returns a Value representing a zero value +// for that type. +// +// See "The Laws of Reflection" for an introduction to reflection in Go: +// http://golang.org/doc/articles/laws_of_reflection.html +package reflect + +import ( + "runtime" + "strconv" + "sync" + "unsafe" +) + +// Type is the representation of a Go type. +// +// Not all methods apply to all kinds of types. Restrictions, +// if any, are noted in the documentation for each method. +// Use the Kind method to find out the kind of type before +// calling kind-specific methods. Calling a method +// inappropriate to the kind of type causes a run-time panic. +type Type interface { + // Methods applicable to all types. + + // Align returns the alignment in bytes of a value of + // this type when allocated in memory. + Align() int + + // FieldAlign returns the alignment in bytes of a value of + // this type when used as a field in a struct. + FieldAlign() int + + // Method returns the i'th method in the type's method set. + // It panics if i is not in the range [0, NumMethod()). + // + // For a non-interface type T or *T, the returned Method's Type and Func + // fields describe a function whose first argument is the receiver. + // + // For an interface type, the returned Method's Type field gives the + // method signature, without a receiver, and the Func field is nil. + Method(int) Method + + // MethodByName returns the method with that name in the type's + // method set and a boolean indicating if the method was found. + // + // For a non-interface type T or *T, the returned Method's Type and Func + // fields describe a function whose first argument is the receiver. + // + // For an interface type, the returned Method's Type field gives the + // method signature, without a receiver, and the Func field is nil. + MethodByName(string) (Method, bool) + + // NumMethod returns the number of methods in the type's method set. + NumMethod() int + + // Name returns the type's name within its package. + // It returns an empty string for unnamed types. + Name() string + + // PkgPath returns a named type's package path, that is, the import path + // that uniquely identifies the package, such as "encoding/base64". + // If the type was predeclared (string, error) or unnamed (*T, struct{}, []int), + // the package path will be the empty string. + PkgPath() string + + // Size returns the number of bytes needed to store + // a value of the given type; it is analogous to unsafe.Sizeof. + Size() uintptr + + // String returns a string representation of the type. + // The string representation may use shortened package names + // (e.g., base64 instead of "encoding/base64") and is not + // guaranteed to be unique among types. To test for equality, + // compare the Types directly. + String() string + + // Kind returns the specific kind of this type. + Kind() Kind + + // Implements returns true if the type implements the interface type u. + Implements(u Type) bool + + // AssignableTo returns true if a value of the type is assignable to type u. + AssignableTo(u Type) bool + + // ConvertibleTo returns true if a value of the type is convertible to type u. + ConvertibleTo(u Type) bool + + // Comparable returns true if values of this type are comparable. + Comparable() bool + + // Methods applicable only to some types, depending on Kind. + // The methods allowed for each kind are: + // + // Int*, Uint*, Float*, Complex*: Bits + // Array: Elem, Len + // Chan: ChanDir, Elem + // Func: In, NumIn, Out, NumOut, IsVariadic. + // Map: Key, Elem + // Ptr: Elem + // Slice: Elem + // Struct: Field, FieldByIndex, FieldByName, FieldByNameFunc, NumField + + // Bits returns the size of the type in bits. + // It panics if the type's Kind is not one of the + // sized or unsized Int, Uint, Float, or Complex kinds. + Bits() int + + // ChanDir returns a channel type's direction. + // It panics if the type's Kind is not Chan. + ChanDir() ChanDir + + // IsVariadic returns true if a function type's final input parameter + // is a "..." parameter. If so, t.In(t.NumIn() - 1) returns the parameter's + // implicit actual type []T. + // + // For concreteness, if t represents func(x int, y ... float64), then + // + // t.NumIn() == 2 + // t.In(0) is the reflect.Type for "int" + // t.In(1) is the reflect.Type for "[]float64" + // t.IsVariadic() == true + // + // IsVariadic panics if the type's Kind is not Func. + IsVariadic() bool + + // Elem returns a type's element type. + // It panics if the type's Kind is not Array, Chan, Map, Ptr, or Slice. + Elem() Type + + // Field returns a struct type's i'th field. + // It panics if the type's Kind is not Struct. + // It panics if i is not in the range [0, NumField()). + Field(i int) StructField + + // FieldByIndex returns the nested field corresponding + // to the index sequence. It is equivalent to calling Field + // successively for each index i. + // It panics if the type's Kind is not Struct. + FieldByIndex(index []int) StructField + + // FieldByName returns the struct field with the given name + // and a boolean indicating if the field was found. + FieldByName(name string) (StructField, bool) + + // FieldByNameFunc returns the first struct field with a name + // that satisfies the match function and a boolean indicating if + // the field was found. + FieldByNameFunc(match func(string) bool) (StructField, bool) + + // In returns the type of a function type's i'th input parameter. + // It panics if the type's Kind is not Func. + // It panics if i is not in the range [0, NumIn()). + In(i int) Type + + // Key returns a map type's key type. + // It panics if the type's Kind is not Map. + Key() Type + + // Len returns an array type's length. + // It panics if the type's Kind is not Array. + Len() int + + // NumField returns a struct type's field count. + // It panics if the type's Kind is not Struct. + NumField() int + + // NumIn returns a function type's input parameter count. + // It panics if the type's Kind is not Func. + NumIn() int + + // NumOut returns a function type's output parameter count. + // It panics if the type's Kind is not Func. + NumOut() int + + // Out returns the type of a function type's i'th output parameter. + // It panics if the type's Kind is not Func. + // It panics if i is not in the range [0, NumOut()). + Out(i int) Type + + common() *rtype + uncommon() *uncommonType +} + +// BUG(rsc): FieldByName and related functions consider struct field names to be equal +// if the names are equal, even if they are unexported names originating +// in different packages. The practical effect of this is that the result of +// t.FieldByName("x") is not well defined if the struct type t contains +// multiple fields named x (embedded from different packages). +// FieldByName may return one of the fields named x or may report that there are none. +// See golang.org/issue/4876 for more details. + +/* + * These data structures are known to the compiler (../../cmd/gc/reflect.c). + * A few are known to ../runtime/type.go to convey to debuggers. + * They are also known to ../runtime/type.h. + */ + +// A Kind represents the specific kind of type that a Type represents. +// The zero Kind is not a valid kind. +type Kind uint + +const ( + Invalid Kind = iota + Bool + Int + Int8 + Int16 + Int32 + Int64 + Uint + Uint8 + Uint16 + Uint32 + Uint64 + Uintptr + Float32 + Float64 + Complex64 + Complex128 + Array + Chan + Func + Interface + Map + Ptr + Slice + String + Struct + UnsafePointer +) + +// rtype is the common implementation of most values. +// It is embedded in other, public struct types, but always +// with a unique tag like `reflect:"array"` or `reflect:"ptr"` +// so that code cannot convert from, say, *arrayType to *ptrType. +type rtype struct { + size uintptr + hash uint32 // hash of type; avoids computation in hash tables + _ uint8 // unused/padding + align uint8 // alignment of variable with this type + fieldAlign uint8 // alignment of struct field with this type + kind uint8 // enumeration for C + alg *typeAlg // algorithm table (../runtime/runtime.h:/Alg) + gc [2]unsafe.Pointer // garbage collection data + string *string // string form; unnecessary but undeniably useful + *uncommonType // (relatively) uncommon fields + ptrToThis *rtype // type for pointer to this type, if used in binary or has methods + zero unsafe.Pointer // pointer to zero value +} + +type typeAlg struct { + // function for hashing objects of this type + // (ptr to object, size, seed) -> hash + hash func(unsafe.Pointer, uintptr, uintptr) uintptr + // function for comparing objects of this type + // (ptr to object A, ptr to object B, size) -> ==? + equal func(unsafe.Pointer, unsafe.Pointer, uintptr) bool +} + +// Method on non-interface type +type method struct { + name *string // name of method + pkgPath *string // nil for exported Names; otherwise import path + mtyp *rtype // method type (without receiver) + typ *rtype // .(*FuncType) underneath (with receiver) + ifn unsafe.Pointer // fn used in interface call (one-word receiver) + tfn unsafe.Pointer // fn used for normal method call +} + +// uncommonType is present only for types with names or methods +// (if T is a named type, the uncommonTypes for T and *T have methods). +// Using a pointer to this struct reduces the overall size required +// to describe an unnamed type with no methods. +type uncommonType struct { + name *string // name of type + pkgPath *string // import path; nil for built-in types like int, string + methods []method // methods associated with type +} + +// ChanDir represents a channel type's direction. +type ChanDir int + +const ( + RecvDir ChanDir = 1 << iota // <-chan + SendDir // chan<- + BothDir = RecvDir | SendDir // chan +) + +// arrayType represents a fixed array type. +type arrayType struct { + rtype `reflect:"array"` + elem *rtype // array element type + slice *rtype // slice type + len uintptr +} + +// chanType represents a channel type. +type chanType struct { + rtype `reflect:"chan"` + elem *rtype // channel element type + dir uintptr // channel direction (ChanDir) +} + +// funcType represents a function type. +type funcType struct { + rtype `reflect:"func"` + dotdotdot bool // last input parameter is ... + in []*rtype // input parameter types + out []*rtype // output parameter types +} + +// imethod represents a method on an interface type +type imethod struct { + name *string // name of method + pkgPath *string // nil for exported Names; otherwise import path + typ *rtype // .(*FuncType) underneath +} + +// interfaceType represents an interface type. +type interfaceType struct { + rtype `reflect:"interface"` + methods []imethod // sorted by hash +} + +// mapType represents a map type. +type mapType struct { + rtype `reflect:"map"` + key *rtype // map key type + elem *rtype // map element (value) type + bucket *rtype // internal bucket structure + hmap *rtype // internal map header + keysize uint8 // size of key slot + indirectkey uint8 // store ptr to key instead of key itself + valuesize uint8 // size of value slot + indirectvalue uint8 // store ptr to value instead of value itself + bucketsize uint16 // size of bucket +} + +// ptrType represents a pointer type. +type ptrType struct { + rtype `reflect:"ptr"` + elem *rtype // pointer element (pointed at) type +} + +// sliceType represents a slice type. +type sliceType struct { + rtype `reflect:"slice"` + elem *rtype // slice element type +} + +// Struct field +type structField struct { + name *string // nil for embedded fields + pkgPath *string // nil for exported Names; otherwise import path + typ *rtype // type of field + tag *string // nil if no tag + offset uintptr // byte offset of field within struct +} + +// structType represents a struct type. +type structType struct { + rtype `reflect:"struct"` + fields []structField // sorted by offset +} + +/* + * The compiler knows the exact layout of all the data structures above. + * The compiler does not know about the data structures and methods below. + */ + +// Method represents a single method. +type Method struct { + // Name is the method name. + // PkgPath is the package path that qualifies a lower case (unexported) + // method name. It is empty for upper case (exported) method names. + // The combination of PkgPath and Name uniquely identifies a method + // in a method set. + // See http://golang.org/ref/spec#Uniqueness_of_identifiers + Name string + PkgPath string + + Type Type // method type + Func Value // func with receiver as first argument + Index int // index for Type.Method +} + +const ( + kindDirectIface = 1 << 5 + kindGCProg = 1 << 6 // Type.gc points to GC program + kindNoPointers = 1 << 7 + kindMask = (1 << 5) - 1 +) + +func (k Kind) String() string { + if int(k) < len(kindNames) { + return kindNames[k] + } + return "kind" + strconv.Itoa(int(k)) +} + +var kindNames = []string{ + Invalid: "invalid", + Bool: "bool", + Int: "int", + Int8: "int8", + Int16: "int16", + Int32: "int32", + Int64: "int64", + Uint: "uint", + Uint8: "uint8", + Uint16: "uint16", + Uint32: "uint32", + Uint64: "uint64", + Uintptr: "uintptr", + Float32: "float32", + Float64: "float64", + Complex64: "complex64", + Complex128: "complex128", + Array: "array", + Chan: "chan", + Func: "func", + Interface: "interface", + Map: "map", + Ptr: "ptr", + Slice: "slice", + String: "string", + Struct: "struct", + UnsafePointer: "unsafe.Pointer", +} + +func (t *uncommonType) uncommon() *uncommonType { + return t +} + +func (t *uncommonType) PkgPath() string { + if t == nil || t.pkgPath == nil { + return "" + } + return *t.pkgPath +} + +func (t *uncommonType) Name() string { + if t == nil || t.name == nil { + return "" + } + return *t.name +} + +func (t *rtype) String() string { return *t.string } + +func (t *rtype) Size() uintptr { return t.size } + +func (t *rtype) Bits() int { + if t == nil { + panic("reflect: Bits of nil Type") + } + k := t.Kind() + if k < Int || k > Complex128 { + panic("reflect: Bits of non-arithmetic Type " + t.String()) + } + return int(t.size) * 8 +} + +func (t *rtype) Align() int { return int(t.align) } + +func (t *rtype) FieldAlign() int { return int(t.fieldAlign) } + +func (t *rtype) Kind() Kind { return Kind(t.kind & kindMask) } + +func (t *rtype) pointers() bool { return t.kind&kindNoPointers == 0 } + +func (t *rtype) common() *rtype { return t } + +func (t *uncommonType) Method(i int) (m Method) { + if t == nil || i < 0 || i >= len(t.methods) { + panic("reflect: Method index out of range") + } + p := &t.methods[i] + if p.name != nil { + m.Name = *p.name + } + fl := flag(Func) + if p.pkgPath != nil { + m.PkgPath = *p.pkgPath + fl |= flagRO + } + mt := p.typ + m.Type = mt + fn := unsafe.Pointer(&p.tfn) + m.Func = Value{mt, fn, fl} + m.Index = i + return +} + +func (t *uncommonType) NumMethod() int { + if t == nil { + return 0 + } + return len(t.methods) +} + +func (t *uncommonType) MethodByName(name string) (m Method, ok bool) { + if t == nil { + return + } + var p *method + for i := range t.methods { + p = &t.methods[i] + if p.name != nil && *p.name == name { + return t.Method(i), true + } + } + return +} + +// TODO(rsc): 6g supplies these, but they are not +// as efficient as they could be: they have commonType +// as the receiver instead of *rtype. +func (t *rtype) NumMethod() int { + if t.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(t)) + return tt.NumMethod() + } + return t.uncommonType.NumMethod() +} + +func (t *rtype) Method(i int) (m Method) { + if t.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(t)) + return tt.Method(i) + } + return t.uncommonType.Method(i) +} + +func (t *rtype) MethodByName(name string) (m Method, ok bool) { + if t.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(t)) + return tt.MethodByName(name) + } + return t.uncommonType.MethodByName(name) +} + +func (t *rtype) PkgPath() string { + return t.uncommonType.PkgPath() +} + +func (t *rtype) Name() string { + return t.uncommonType.Name() +} + +func (t *rtype) ChanDir() ChanDir { + if t.Kind() != Chan { + panic("reflect: ChanDir of non-chan type") + } + tt := (*chanType)(unsafe.Pointer(t)) + return ChanDir(tt.dir) +} + +func (t *rtype) IsVariadic() bool { + if t.Kind() != Func { + panic("reflect: IsVariadic of non-func type") + } + tt := (*funcType)(unsafe.Pointer(t)) + return tt.dotdotdot +} + +func (t *rtype) Elem() Type { + switch t.Kind() { + case Array: + tt := (*arrayType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Chan: + tt := (*chanType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Map: + tt := (*mapType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Ptr: + tt := (*ptrType)(unsafe.Pointer(t)) + return toType(tt.elem) + case Slice: + tt := (*sliceType)(unsafe.Pointer(t)) + return toType(tt.elem) + } + panic("reflect: Elem of invalid type") +} + +func (t *rtype) Field(i int) StructField { + if t.Kind() != Struct { + panic("reflect: Field of non-struct type") + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.Field(i) +} + +func (t *rtype) FieldByIndex(index []int) StructField { + if t.Kind() != Struct { + panic("reflect: FieldByIndex of non-struct type") + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.FieldByIndex(index) +} + +func (t *rtype) FieldByName(name string) (StructField, bool) { + if t.Kind() != Struct { + panic("reflect: FieldByName of non-struct type") + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.FieldByName(name) +} + +func (t *rtype) FieldByNameFunc(match func(string) bool) (StructField, bool) { + if t.Kind() != Struct { + panic("reflect: FieldByNameFunc of non-struct type") + } + tt := (*structType)(unsafe.Pointer(t)) + return tt.FieldByNameFunc(match) +} + +func (t *rtype) In(i int) Type { + if t.Kind() != Func { + panic("reflect: In of non-func type") + } + tt := (*funcType)(unsafe.Pointer(t)) + return toType(tt.in[i]) +} + +func (t *rtype) Key() Type { + if t.Kind() != Map { + panic("reflect: Key of non-map type") + } + tt := (*mapType)(unsafe.Pointer(t)) + return toType(tt.key) +} + +func (t *rtype) Len() int { + if t.Kind() != Array { + panic("reflect: Len of non-array type") + } + tt := (*arrayType)(unsafe.Pointer(t)) + return int(tt.len) +} + +func (t *rtype) NumField() int { + if t.Kind() != Struct { + panic("reflect: NumField of non-struct type") + } + tt := (*structType)(unsafe.Pointer(t)) + return len(tt.fields) +} + +func (t *rtype) NumIn() int { + if t.Kind() != Func { + panic("reflect: NumIn of non-func type") + } + tt := (*funcType)(unsafe.Pointer(t)) + return len(tt.in) +} + +func (t *rtype) NumOut() int { + if t.Kind() != Func { + panic("reflect: NumOut of non-func type") + } + tt := (*funcType)(unsafe.Pointer(t)) + return len(tt.out) +} + +func (t *rtype) Out(i int) Type { + if t.Kind() != Func { + panic("reflect: Out of non-func type") + } + tt := (*funcType)(unsafe.Pointer(t)) + return toType(tt.out[i]) +} + +func (d ChanDir) String() string { + switch d { + case SendDir: + return "chan<-" + case RecvDir: + return "<-chan" + case BothDir: + return "chan" + } + return "ChanDir" + strconv.Itoa(int(d)) +} + +// Method returns the i'th method in the type's method set. +func (t *interfaceType) Method(i int) (m Method) { + if i < 0 || i >= len(t.methods) { + return + } + p := &t.methods[i] + m.Name = *p.name + if p.pkgPath != nil { + m.PkgPath = *p.pkgPath + } + m.Type = toType(p.typ) + m.Index = i + return +} + +// NumMethod returns the number of interface methods in the type's method set. +func (t *interfaceType) NumMethod() int { return len(t.methods) } + +// MethodByName method with the given name in the type's method set. +func (t *interfaceType) MethodByName(name string) (m Method, ok bool) { + if t == nil { + return + } + var p *imethod + for i := range t.methods { + p = &t.methods[i] + if *p.name == name { + return t.Method(i), true + } + } + return +} + +// A StructField describes a single field in a struct. +type StructField struct { + // Name is the field name. + // PkgPath is the package path that qualifies a lower case (unexported) + // field name. It is empty for upper case (exported) field names. + // See http://golang.org/ref/spec#Uniqueness_of_identifiers + Name string + PkgPath string + + Type Type // field type + Tag StructTag // field tag string + Offset uintptr // offset within struct, in bytes + Index []int // index sequence for Type.FieldByIndex + Anonymous bool // is an embedded field +} + +// A StructTag is the tag string in a struct field. +// +// By convention, tag strings are a concatenation of +// optionally space-separated key:"value" pairs. +// Each key is a non-empty string consisting of non-control +// characters other than space (U+0020 ' '), quote (U+0022 '"'), +// and colon (U+003A ':'). Each value is quoted using U+0022 '"' +// characters and Go string literal syntax. +type StructTag string + +// Get returns the value associated with key in the tag string. +// If there is no such key in the tag, Get returns the empty string. +// If the tag does not have the conventional format, the value +// returned by Get is unspecified. +func (tag StructTag) Get(key string) string { + for tag != "" { + // skip leading space + i := 0 + for i < len(tag) && tag[i] == ' ' { + i++ + } + tag = tag[i:] + if tag == "" { + break + } + + // scan to colon. + // a space or a quote is a syntax error + i = 0 + for i < len(tag) && tag[i] != ' ' && tag[i] != ':' && tag[i] != '"' { + i++ + } + if i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' { + break + } + name := string(tag[:i]) + tag = tag[i+1:] + + // scan quoted string to find value + i = 1 + for i < len(tag) && tag[i] != '"' { + if tag[i] == '\\' { + i++ + } + i++ + } + if i >= len(tag) { + break + } + qvalue := string(tag[:i+1]) + tag = tag[i+1:] + + if key == name { + value, _ := strconv.Unquote(qvalue) + return value + } + } + return "" +} + +// Field returns the i'th struct field. +func (t *structType) Field(i int) (f StructField) { + if i < 0 || i >= len(t.fields) { + return + } + p := &t.fields[i] + f.Type = toType(p.typ) + if p.name != nil { + f.Name = *p.name + } else { + t := f.Type + if t.Kind() == Ptr { + t = t.Elem() + } + f.Name = t.Name() + f.Anonymous = true + } + if p.pkgPath != nil { + f.PkgPath = *p.pkgPath + } + if p.tag != nil { + f.Tag = StructTag(*p.tag) + } + f.Offset = p.offset + + // NOTE(rsc): This is the only allocation in the interface + // presented by a reflect.Type. It would be nice to avoid, + // at least in the common cases, but we need to make sure + // that misbehaving clients of reflect cannot affect other + // uses of reflect. One possibility is CL 5371098, but we + // postponed that ugliness until there is a demonstrated + // need for the performance. This is issue 2320. + f.Index = []int{i} + return +} + +// TODO(gri): Should there be an error/bool indicator if the index +// is wrong for FieldByIndex? + +// FieldByIndex returns the nested field corresponding to index. +func (t *structType) FieldByIndex(index []int) (f StructField) { + f.Type = toType(&t.rtype) + for i, x := range index { + if i > 0 { + ft := f.Type + if ft.Kind() == Ptr && ft.Elem().Kind() == Struct { + ft = ft.Elem() + } + f.Type = ft + } + f = f.Type.Field(x) + } + return +} + +// A fieldScan represents an item on the fieldByNameFunc scan work list. +type fieldScan struct { + typ *structType + index []int +} + +// FieldByNameFunc returns the struct field with a name that satisfies the +// match function and a boolean to indicate if the field was found. +func (t *structType) FieldByNameFunc(match func(string) bool) (result StructField, ok bool) { + // This uses the same condition that the Go language does: there must be a unique instance + // of the match at a given depth level. If there are multiple instances of a match at the + // same depth, they annihilate each other and inhibit any possible match at a lower level. + // The algorithm is breadth first search, one depth level at a time. + + // The current and next slices are work queues: + // current lists the fields to visit on this depth level, + // and next lists the fields on the next lower level. + current := []fieldScan{} + next := []fieldScan{{typ: t}} + + // nextCount records the number of times an embedded type has been + // encountered and considered for queueing in the 'next' slice. + // We only queue the first one, but we increment the count on each. + // If a struct type T can be reached more than once at a given depth level, + // then it annihilates itself and need not be considered at all when we + // process that next depth level. + var nextCount map[*structType]int + + // visited records the structs that have been considered already. + // Embedded pointer fields can create cycles in the graph of + // reachable embedded types; visited avoids following those cycles. + // It also avoids duplicated effort: if we didn't find the field in an + // embedded type T at level 2, we won't find it in one at level 4 either. + visited := map[*structType]bool{} + + for len(next) > 0 { + current, next = next, current[:0] + count := nextCount + nextCount = nil + + // Process all the fields at this depth, now listed in 'current'. + // The loop queues embedded fields found in 'next', for processing during the next + // iteration. The multiplicity of the 'current' field counts is recorded + // in 'count'; the multiplicity of the 'next' field counts is recorded in 'nextCount'. + for _, scan := range current { + t := scan.typ + if visited[t] { + // We've looked through this type before, at a higher level. + // That higher level would shadow the lower level we're now at, + // so this one can't be useful to us. Ignore it. + continue + } + visited[t] = true + for i := range t.fields { + f := &t.fields[i] + // Find name and type for field f. + var fname string + var ntyp *rtype + if f.name != nil { + fname = *f.name + } else { + // Anonymous field of type T or *T. + // Name taken from type. + ntyp = f.typ + if ntyp.Kind() == Ptr { + ntyp = ntyp.Elem().common() + } + fname = ntyp.Name() + } + + // Does it match? + if match(fname) { + // Potential match + if count[t] > 1 || ok { + // Name appeared multiple times at this level: annihilate. + return StructField{}, false + } + result = t.Field(i) + result.Index = nil + result.Index = append(result.Index, scan.index...) + result.Index = append(result.Index, i) + ok = true + continue + } + + // Queue embedded struct fields for processing with next level, + // but only if we haven't seen a match yet at this level and only + // if the embedded types haven't already been queued. + if ok || ntyp == nil || ntyp.Kind() != Struct { + continue + } + styp := (*structType)(unsafe.Pointer(ntyp)) + if nextCount[styp] > 0 { + nextCount[styp] = 2 // exact multiple doesn't matter + continue + } + if nextCount == nil { + nextCount = map[*structType]int{} + } + nextCount[styp] = 1 + if count[t] > 1 { + nextCount[styp] = 2 // exact multiple doesn't matter + } + var index []int + index = append(index, scan.index...) + index = append(index, i) + next = append(next, fieldScan{styp, index}) + } + } + if ok { + break + } + } + return +} + +// FieldByName returns the struct field with the given name +// and a boolean to indicate if the field was found. +func (t *structType) FieldByName(name string) (f StructField, present bool) { + // Quick check for top-level name, or struct without anonymous fields. + hasAnon := false + if name != "" { + for i := range t.fields { + tf := &t.fields[i] + if tf.name == nil { + hasAnon = true + continue + } + if *tf.name == name { + return t.Field(i), true + } + } + } + if !hasAnon { + return + } + return t.FieldByNameFunc(func(s string) bool { return s == name }) +} + +// TypeOf returns the reflection Type of the value in the interface{}. +// TypeOf(nil) returns nil. +func TypeOf(i interface{}) Type { + eface := *(*emptyInterface)(unsafe.Pointer(&i)) + return toType(eface.typ) +} + +// ptrMap is the cache for PtrTo. +var ptrMap struct { + sync.RWMutex + m map[*rtype]*ptrType +} + +// PtrTo returns the pointer type with element t. +// For example, if t represents type Foo, PtrTo(t) represents *Foo. +func PtrTo(t Type) Type { + return t.(*rtype).ptrTo() +} + +func (t *rtype) ptrTo() *rtype { + if p := t.ptrToThis; p != nil { + return p + } + + // Otherwise, synthesize one. + // This only happens for pointers with no methods. + // We keep the mapping in a map on the side, because + // this operation is rare and a separate map lets us keep + // the type structures in read-only memory. + ptrMap.RLock() + if m := ptrMap.m; m != nil { + if p := m[t]; p != nil { + ptrMap.RUnlock() + return &p.rtype + } + } + ptrMap.RUnlock() + ptrMap.Lock() + if ptrMap.m == nil { + ptrMap.m = make(map[*rtype]*ptrType) + } + p := ptrMap.m[t] + if p != nil { + // some other goroutine won the race and created it + ptrMap.Unlock() + return &p.rtype + } + + // Create a new ptrType starting with the description + // of an *unsafe.Pointer. + p = new(ptrType) + var iptr interface{} = (*unsafe.Pointer)(nil) + prototype := *(**ptrType)(unsafe.Pointer(&iptr)) + *p = *prototype + + s := "*" + *t.string + p.string = &s + + // For the type structures linked into the binary, the + // compiler provides a good hash of the string. + // Create a good hash for the new string by using + // the FNV-1 hash's mixing function to combine the + // old hash and the new "*". + p.hash = fnv1(t.hash, '*') + + p.uncommonType = nil + p.ptrToThis = nil + p.zero = unsafe.Pointer(&make([]byte, p.size)[0]) + p.elem = t + + ptrMap.m[t] = p + ptrMap.Unlock() + return &p.rtype +} + +// fnv1 incorporates the list of bytes into the hash x using the FNV-1 hash function. +func fnv1(x uint32, list ...byte) uint32 { + for _, b := range list { + x = x*16777619 ^ uint32(b) + } + return x +} + +func (t *rtype) Implements(u Type) bool { + if u == nil { + panic("reflect: nil type passed to Type.Implements") + } + if u.Kind() != Interface { + panic("reflect: non-interface type passed to Type.Implements") + } + return implements(u.(*rtype), t) +} + +func (t *rtype) AssignableTo(u Type) bool { + if u == nil { + panic("reflect: nil type passed to Type.AssignableTo") + } + uu := u.(*rtype) + return directlyAssignable(uu, t) || implements(uu, t) +} + +func (t *rtype) ConvertibleTo(u Type) bool { + if u == nil { + panic("reflect: nil type passed to Type.ConvertibleTo") + } + uu := u.(*rtype) + return convertOp(uu, t) != nil +} + +func (t *rtype) Comparable() bool { + return t.alg != nil && t.alg.equal != nil +} + +// implements returns true if the type V implements the interface type T. +func implements(T, V *rtype) bool { + if T.Kind() != Interface { + return false + } + t := (*interfaceType)(unsafe.Pointer(T)) + if len(t.methods) == 0 { + return true + } + + // The same algorithm applies in both cases, but the + // method tables for an interface type and a concrete type + // are different, so the code is duplicated. + // In both cases the algorithm is a linear scan over the two + // lists - T's methods and V's methods - simultaneously. + // Since method tables are stored in a unique sorted order + // (alphabetical, with no duplicate method names), the scan + // through V's methods must hit a match for each of T's + // methods along the way, or else V does not implement T. + // This lets us run the scan in overall linear time instead of + // the quadratic time a naive search would require. + // See also ../runtime/iface.c. + if V.Kind() == Interface { + v := (*interfaceType)(unsafe.Pointer(V)) + i := 0 + for j := 0; j < len(v.methods); j++ { + tm := &t.methods[i] + vm := &v.methods[j] + if vm.name == tm.name && vm.pkgPath == tm.pkgPath && vm.typ == tm.typ { + if i++; i >= len(t.methods) { + return true + } + } + } + return false + } + + v := V.uncommon() + if v == nil { + return false + } + i := 0 + for j := 0; j < len(v.methods); j++ { + tm := &t.methods[i] + vm := &v.methods[j] + if vm.name == tm.name && vm.pkgPath == tm.pkgPath && vm.mtyp == tm.typ { + if i++; i >= len(t.methods) { + return true + } + } + } + return false +} + +// directlyAssignable returns true if a value x of type V can be directly +// assigned (using memmove) to a value of type T. +// http://golang.org/doc/go_spec.html#Assignability +// Ignoring the interface rules (implemented elsewhere) +// and the ideal constant rules (no ideal constants at run time). +func directlyAssignable(T, V *rtype) bool { + // x's type V is identical to T? + if T == V { + return true + } + + // Otherwise at least one of T and V must be unnamed + // and they must have the same kind. + if T.Name() != "" && V.Name() != "" || T.Kind() != V.Kind() { + return false + } + + // x's type T and V must have identical underlying types. + return haveIdenticalUnderlyingType(T, V) +} + +func haveIdenticalUnderlyingType(T, V *rtype) bool { + if T == V { + return true + } + + kind := T.Kind() + if kind != V.Kind() { + return false + } + + // Non-composite types of equal kind have same underlying type + // (the predefined instance of the type). + if Bool <= kind && kind <= Complex128 || kind == String || kind == UnsafePointer { + return true + } + + // Composite types. + switch kind { + case Array: + return T.Elem() == V.Elem() && T.Len() == V.Len() + + case Chan: + // Special case: + // x is a bidirectional channel value, T is a channel type, + // and x's type V and T have identical element types. + if V.ChanDir() == BothDir && T.Elem() == V.Elem() { + return true + } + + // Otherwise continue test for identical underlying type. + return V.ChanDir() == T.ChanDir() && T.Elem() == V.Elem() + + case Func: + t := (*funcType)(unsafe.Pointer(T)) + v := (*funcType)(unsafe.Pointer(V)) + if t.dotdotdot != v.dotdotdot || len(t.in) != len(v.in) || len(t.out) != len(v.out) { + return false + } + for i, typ := range t.in { + if typ != v.in[i] { + return false + } + } + for i, typ := range t.out { + if typ != v.out[i] { + return false + } + } + return true + + case Interface: + t := (*interfaceType)(unsafe.Pointer(T)) + v := (*interfaceType)(unsafe.Pointer(V)) + if len(t.methods) == 0 && len(v.methods) == 0 { + return true + } + // Might have the same methods but still + // need a run time conversion. + return false + + case Map: + return T.Key() == V.Key() && T.Elem() == V.Elem() + + case Ptr, Slice: + return T.Elem() == V.Elem() + + case Struct: + t := (*structType)(unsafe.Pointer(T)) + v := (*structType)(unsafe.Pointer(V)) + if len(t.fields) != len(v.fields) { + return false + } + for i := range t.fields { + tf := &t.fields[i] + vf := &v.fields[i] + if tf.name != vf.name && (tf.name == nil || vf.name == nil || *tf.name != *vf.name) { + return false + } + if tf.pkgPath != vf.pkgPath && (tf.pkgPath == nil || vf.pkgPath == nil || *tf.pkgPath != *vf.pkgPath) { + return false + } + if tf.typ != vf.typ { + return false + } + if tf.tag != vf.tag && (tf.tag == nil || vf.tag == nil || *tf.tag != *vf.tag) { + return false + } + if tf.offset != vf.offset { + return false + } + } + return true + } + + return false +} + +// typelinks is implemented in package runtime. +// It returns a slice of all the 'typelink' information in the binary, +// which is to say a slice of known types, sorted by string. +// Note that strings are not unique identifiers for types: +// there can be more than one with a given string. +// Only types we might want to look up are included: +// channels, maps, slices, and arrays. +func typelinks() []*rtype + +// typesByString returns the subslice of typelinks() whose elements have +// the given string representation. +// It may be empty (no known types with that string) or may have +// multiple elements (multiple types with that string). +func typesByString(s string) []*rtype { + typ := typelinks() + + // We are looking for the first index i where the string becomes >= s. + // This is a copy of sort.Search, with f(h) replaced by (*typ[h].string >= s). + i, j := 0, len(typ) + for i < j { + h := i + (j-i)/2 // avoid overflow when computing h + // i ≤ h < j + if !(*typ[h].string >= s) { + i = h + 1 // preserves f(i-1) == false + } else { + j = h // preserves f(j) == true + } + } + // i == j, f(i-1) == false, and f(j) (= f(i)) == true => answer is i. + + // Having found the first, linear scan forward to find the last. + // We could do a second binary search, but the caller is going + // to do a linear scan anyway. + j = i + for j < len(typ) && *typ[j].string == s { + j++ + } + + // This slice will be empty if the string is not found. + return typ[i:j] +} + +// The lookupCache caches ChanOf, MapOf, and SliceOf lookups. +var lookupCache struct { + sync.RWMutex + m map[cacheKey]*rtype +} + +// A cacheKey is the key for use in the lookupCache. +// Four values describe any of the types we are looking for: +// type kind, one or two subtypes, and an extra integer. +type cacheKey struct { + kind Kind + t1 *rtype + t2 *rtype + extra uintptr +} + +// cacheGet looks for a type under the key k in the lookupCache. +// If it finds one, it returns that type. +// If not, it returns nil with the cache locked. +// The caller is expected to use cachePut to unlock the cache. +func cacheGet(k cacheKey) Type { + lookupCache.RLock() + t := lookupCache.m[k] + lookupCache.RUnlock() + if t != nil { + return t + } + + lookupCache.Lock() + t = lookupCache.m[k] + if t != nil { + lookupCache.Unlock() + return t + } + + if lookupCache.m == nil { + lookupCache.m = make(map[cacheKey]*rtype) + } + + return nil +} + +// cachePut stores the given type in the cache, unlocks the cache, +// and returns the type. It is expected that the cache is locked +// because cacheGet returned nil. +func cachePut(k cacheKey, t *rtype) Type { + lookupCache.m[k] = t + lookupCache.Unlock() + return t +} + +// ChanOf returns the channel type with the given direction and element type. +// For example, if t represents int, ChanOf(RecvDir, t) represents <-chan int. +// +// The gc runtime imposes a limit of 64 kB on channel element types. +// If t's size is equal to or exceeds this limit, ChanOf panics. +func ChanOf(dir ChanDir, t Type) Type { + typ := t.(*rtype) + + // Look in cache. + ckey := cacheKey{Chan, typ, nil, uintptr(dir)} + if ch := cacheGet(ckey); ch != nil { + return ch + } + + // This restriction is imposed by the gc compiler and the runtime. + if typ.size >= 1<<16 { + lookupCache.Unlock() + panic("reflect.ChanOf: element size too large") + } + + // Look in known types. + // TODO: Precedence when constructing string. + var s string + switch dir { + default: + lookupCache.Unlock() + panic("reflect.ChanOf: invalid dir") + case SendDir: + s = "chan<- " + *typ.string + case RecvDir: + s = "<-chan " + *typ.string + case BothDir: + s = "chan " + *typ.string + } + for _, tt := range typesByString(s) { + ch := (*chanType)(unsafe.Pointer(tt)) + if ch.elem == typ && ch.dir == uintptr(dir) { + return cachePut(ckey, tt) + } + } + + // Make a channel type. + var ichan interface{} = (chan unsafe.Pointer)(nil) + prototype := *(**chanType)(unsafe.Pointer(&ichan)) + ch := new(chanType) + *ch = *prototype + ch.string = &s + ch.hash = fnv1(typ.hash, 'c', byte(dir)) + ch.elem = typ + ch.uncommonType = nil + ch.ptrToThis = nil + ch.zero = unsafe.Pointer(&make([]byte, ch.size)[0]) + + return cachePut(ckey, &ch.rtype) +} + +func ismapkey(*rtype) bool // implemented in runtime + +// MapOf returns the map type with the given key and element types. +// For example, if k represents int and e represents string, +// MapOf(k, e) represents map[int]string. +// +// If the key type is not a valid map key type (that is, if it does +// not implement Go's == operator), MapOf panics. +func MapOf(key, elem Type) Type { + ktyp := key.(*rtype) + etyp := elem.(*rtype) + + if !ismapkey(ktyp) { + panic("reflect.MapOf: invalid key type " + ktyp.String()) + } + + // Look in cache. + ckey := cacheKey{Map, ktyp, etyp, 0} + if mt := cacheGet(ckey); mt != nil { + return mt + } + + // Look in known types. + s := "map[" + *ktyp.string + "]" + *etyp.string + for _, tt := range typesByString(s) { + mt := (*mapType)(unsafe.Pointer(tt)) + if mt.key == ktyp && mt.elem == etyp { + return cachePut(ckey, tt) + } + } + + // Make a map type. + var imap interface{} = (map[unsafe.Pointer]unsafe.Pointer)(nil) + prototype := *(**mapType)(unsafe.Pointer(&imap)) + mt := new(mapType) + *mt = *prototype + mt.string = &s + mt.hash = fnv1(etyp.hash, 'm', byte(ktyp.hash>>24), byte(ktyp.hash>>16), byte(ktyp.hash>>8), byte(ktyp.hash)) + mt.key = ktyp + mt.elem = etyp + mt.bucket = bucketOf(ktyp, etyp) + if ktyp.size > maxKeySize { + mt.keysize = uint8(ptrSize) + mt.indirectkey = 1 + } else { + mt.keysize = uint8(ktyp.size) + mt.indirectkey = 0 + } + if etyp.size > maxValSize { + mt.valuesize = uint8(ptrSize) + mt.indirectvalue = 1 + } else { + mt.valuesize = uint8(etyp.size) + mt.indirectvalue = 0 + } + mt.bucketsize = uint16(mt.bucket.size) + mt.uncommonType = nil + mt.ptrToThis = nil + mt.zero = unsafe.Pointer(&make([]byte, mt.size)[0]) + + return cachePut(ckey, &mt.rtype) +} + +// gcProg is a helper type for generatation of GC pointer info. +type gcProg struct { + gc []byte + size uintptr // size of type in bytes +} + +func (gc *gcProg) append(v byte) { + gc.align(unsafe.Sizeof(uintptr(0))) + gc.appendWord(v) +} + +// Appends t's type info to the current program. +func (gc *gcProg) appendProg(t *rtype) { + gc.align(uintptr(t.align)) + if !t.pointers() { + gc.size += t.size + return + } + switch t.Kind() { + default: + panic("reflect: non-pointer type marked as having pointers") + case Ptr, UnsafePointer, Chan, Func, Map: + gc.appendWord(bitsPointer) + case Slice: + gc.appendWord(bitsPointer) + gc.appendWord(bitsScalar) + gc.appendWord(bitsScalar) + case String: + gc.appendWord(bitsPointer) + gc.appendWord(bitsScalar) + case Array: + c := t.Len() + e := t.Elem().common() + for i := 0; i < c; i++ { + gc.appendProg(e) + } + case Interface: + gc.appendWord(bitsMultiWord) + if t.NumMethod() == 0 { + gc.appendWord(bitsEface) + } else { + gc.appendWord(bitsIface) + } + case Struct: + c := t.NumField() + for i := 0; i < c; i++ { + gc.appendProg(t.Field(i).Type.common()) + } + gc.align(uintptr(t.align)) + } +} + +func (gc *gcProg) appendWord(v byte) { + ptrsize := unsafe.Sizeof(uintptr(0)) + if gc.size%ptrsize != 0 { + panic("reflect: unaligned GC program") + } + nptr := gc.size / ptrsize + for uintptr(len(gc.gc)) < nptr/2+1 { + gc.gc = append(gc.gc, 0x44) // BitsScalar + } + gc.gc[nptr/2] &= ^(3 << ((nptr%2)*4 + 2)) + gc.gc[nptr/2] |= v << ((nptr%2)*4 + 2) + gc.size += ptrsize +} + +func (gc *gcProg) finalize() unsafe.Pointer { + if gc.size == 0 { + return nil + } + ptrsize := unsafe.Sizeof(uintptr(0)) + gc.align(ptrsize) + nptr := gc.size / ptrsize + for uintptr(len(gc.gc)) < nptr/2+1 { + gc.gc = append(gc.gc, 0x44) // BitsScalar + } + // If number of words is odd, repeat the mask twice. + // Compiler does the same. + if nptr%2 != 0 { + for i := uintptr(0); i < nptr; i++ { + gc.appendWord(extractGCWord(gc.gc, i)) + } + } + return unsafe.Pointer(&gc.gc[0]) +} + +func extractGCWord(gc []byte, i uintptr) byte { + return (gc[i/2] >> ((i%2)*4 + 2)) & 3 +} + +func (gc *gcProg) align(a uintptr) { + gc.size = align(gc.size, a) +} + +// These constants must stay in sync with ../runtime/mgc0.h. +const ( + bitsScalar = 1 + bitsPointer = 2 + bitsMultiWord = 3 + + bitsIface = 2 + bitsEface = 3 +) + +// Make sure these routines stay in sync with ../../runtime/hashmap.go! +// These types exist only for GC, so we only fill out GC relevant info. +// Currently, that's just size and the GC program. We also fill in string +// for possible debugging use. +const ( + bucketSize = 8 + maxKeySize = 128 + maxValSize = 128 +) + +func bucketOf(ktyp, etyp *rtype) *rtype { + if ktyp.size > maxKeySize { + ktyp = PtrTo(ktyp).(*rtype) + } + if etyp.size > maxValSize { + etyp = PtrTo(etyp).(*rtype) + } + ptrsize := unsafe.Sizeof(uintptr(0)) + + var gc gcProg + // topbits + for i := 0; i < int(bucketSize*unsafe.Sizeof(uint8(0))/ptrsize); i++ { + gc.append(bitsScalar) + } + gc.append(bitsPointer) // overflow + if runtime.GOARCH == "amd64p32" { + gc.append(bitsScalar) + } + // keys + for i := 0; i < bucketSize; i++ { + gc.appendProg(ktyp) + } + // values + for i := 0; i < bucketSize; i++ { + gc.appendProg(etyp) + } + + b := new(rtype) + b.size = gc.size + b.gc[0] = gc.finalize() + s := "bucket(" + *ktyp.string + "," + *etyp.string + ")" + b.string = &s + return b +} + +// SliceOf returns the slice type with element type t. +// For example, if t represents int, SliceOf(t) represents []int. +func SliceOf(t Type) Type { + typ := t.(*rtype) + + // Look in cache. + ckey := cacheKey{Slice, typ, nil, 0} + if slice := cacheGet(ckey); slice != nil { + return slice + } + + // Look in known types. + s := "[]" + *typ.string + for _, tt := range typesByString(s) { + slice := (*sliceType)(unsafe.Pointer(tt)) + if slice.elem == typ { + return cachePut(ckey, tt) + } + } + + // Make a slice type. + var islice interface{} = ([]unsafe.Pointer)(nil) + prototype := *(**sliceType)(unsafe.Pointer(&islice)) + slice := new(sliceType) + *slice = *prototype + slice.string = &s + slice.hash = fnv1(typ.hash, '[') + slice.elem = typ + slice.uncommonType = nil + slice.ptrToThis = nil + slice.zero = unsafe.Pointer(&make([]byte, slice.size)[0]) + + return cachePut(ckey, &slice.rtype) +} + +// ArrayOf returns the array type with the given count and element type. +// For example, if t represents int, ArrayOf(5, t) represents [5]int. +// +// If the resulting type would be larger than the available address space, +// ArrayOf panics. +// +// TODO(rsc): Unexported for now. Export once the alg field is set correctly +// for the type. This may require significant work. +// +// TODO(rsc): TestArrayOf is also disabled. Re-enable. +func arrayOf(count int, elem Type) Type { + typ := elem.(*rtype) + slice := SliceOf(elem) + + // Look in cache. + ckey := cacheKey{Array, typ, nil, uintptr(count)} + if slice := cacheGet(ckey); slice != nil { + return slice + } + + // Look in known types. + s := "[" + strconv.Itoa(count) + "]" + *typ.string + for _, tt := range typesByString(s) { + slice := (*sliceType)(unsafe.Pointer(tt)) + if slice.elem == typ { + return cachePut(ckey, tt) + } + } + + // Make an array type. + var iarray interface{} = [1]unsafe.Pointer{} + prototype := *(**arrayType)(unsafe.Pointer(&iarray)) + array := new(arrayType) + *array = *prototype + // TODO: Set extra kind bits correctly. + array.string = &s + array.hash = fnv1(typ.hash, '[') + for n := uint32(count); n > 0; n >>= 8 { + array.hash = fnv1(array.hash, byte(n)) + } + array.hash = fnv1(array.hash, ']') + array.elem = typ + max := ^uintptr(0) / typ.size + if uintptr(count) > max { + panic("reflect.ArrayOf: array size would exceed virtual address space") + } + array.size = typ.size * uintptr(count) + array.align = typ.align + array.fieldAlign = typ.fieldAlign + // TODO: array.alg + // TODO: array.gc + // TODO: + array.uncommonType = nil + array.ptrToThis = nil + array.zero = unsafe.Pointer(&make([]byte, array.size)[0]) + array.len = uintptr(count) + array.slice = slice.(*rtype) + + return cachePut(ckey, &array.rtype) +} + +// toType converts from a *rtype to a Type that can be returned +// to the client of package reflect. In gc, the only concern is that +// a nil *rtype must be replaced by a nil Type, but in gccgo this +// function takes care of ensuring that multiple *rtype for the same +// type are coalesced into a single Type. +func toType(t *rtype) Type { + if t == nil { + return nil + } + return t +} + +type layoutKey struct { + t *rtype // function signature + rcvr *rtype // receiver type, or nil if none +} + +type layoutType struct { + t *rtype + argSize uintptr // size of arguments + retOffset uintptr // offset of return values. + stack *bitVector +} + +var layoutCache struct { + sync.RWMutex + m map[layoutKey]layoutType +} + +// funcLayout computes a struct type representing the layout of the +// function arguments and return values for the function type t. +// If rcvr != nil, rcvr specifies the type of the receiver. +// The returned type exists only for GC, so we only fill out GC relevant info. +// Currently, that's just size and the GC program. We also fill in +// the name for possible debugging use. +func funcLayout(t *rtype, rcvr *rtype) (frametype *rtype, argSize, retOffset uintptr, stack *bitVector) { + if t.Kind() != Func { + panic("reflect: funcLayout of non-func type") + } + if rcvr != nil && rcvr.Kind() == Interface { + panic("reflect: funcLayout with interface receiver " + rcvr.String()) + } + k := layoutKey{t, rcvr} + layoutCache.RLock() + if x := layoutCache.m[k]; x.t != nil { + layoutCache.RUnlock() + return x.t, x.argSize, x.retOffset, x.stack + } + layoutCache.RUnlock() + layoutCache.Lock() + if x := layoutCache.m[k]; x.t != nil { + layoutCache.Unlock() + return x.t, x.argSize, x.retOffset, x.stack + } + + tt := (*funcType)(unsafe.Pointer(t)) + + // compute gc program & stack bitmap for arguments + stack = new(bitVector) + var gc gcProg + var offset uintptr + if rcvr != nil { + // Reflect uses the "interface" calling convention for + // methods, where receivers take one word of argument + // space no matter how big they actually are. + if ifaceIndir(rcvr) { + // we pass a pointer to the receiver. + gc.append(bitsPointer) + stack.append2(bitsPointer) + } else if rcvr.pointers() { + // rcvr is a one-word pointer object. Its gc program + // is just what we need here. + gc.append(bitsPointer) + stack.append2(bitsPointer) + } else { + gc.append(bitsScalar) + stack.append2(bitsScalar) + } + offset += ptrSize + } + for _, arg := range tt.in { + gc.appendProg(arg) + addTypeBits(stack, &offset, arg) + } + argSize = gc.size + if runtime.GOARCH == "amd64p32" { + gc.align(8) + } + gc.align(ptrSize) + retOffset = gc.size + for _, res := range tt.out { + gc.appendProg(res) + // stack map does not need result bits + } + gc.align(ptrSize) + + // build dummy rtype holding gc program + x := new(rtype) + x.size = gc.size + x.gc[0] = gc.finalize() + var s string + if rcvr != nil { + s = "methodargs(" + *rcvr.string + ")(" + *t.string + ")" + } else { + s = "funcargs(" + *t.string + ")" + } + x.string = &s + + // cache result for future callers + if layoutCache.m == nil { + layoutCache.m = make(map[layoutKey]layoutType) + } + layoutCache.m[k] = layoutType{ + t: x, + argSize: argSize, + retOffset: retOffset, + stack: stack, + } + layoutCache.Unlock() + return x, argSize, retOffset, stack +} + +// ifaceIndir reports whether t is stored indirectly in an interface value. +func ifaceIndir(t *rtype) bool { + return t.kind&kindDirectIface == 0 +} + +// Layout matches runtime.BitVector (well enough). +type bitVector struct { + n uint32 // number of bits + data []byte +} + +// append a bit pair to the bitmap. +func (bv *bitVector) append2(bits uint8) { + // assume bv.n is a multiple of 2, since append2 is the only operation. + if bv.n%8 == 0 { + bv.data = append(bv.data, 0) + } + bv.data[bv.n/8] |= bits << (bv.n % 8) + bv.n += 2 +} + +func addTypeBits(bv *bitVector, offset *uintptr, t *rtype) { + *offset = align(*offset, uintptr(t.align)) + if t.kind&kindNoPointers != 0 { + *offset += t.size + return + } + + switch Kind(t.kind & kindMask) { + case Chan, Func, Map, Ptr, Slice, String, UnsafePointer: + // 1 pointer at start of representation + for bv.n < 2*uint32(*offset/uintptr(ptrSize)) { + bv.append2(bitsScalar) + } + bv.append2(bitsPointer) + + case Interface: + // 2 pointers + for bv.n < 2*uint32(*offset/uintptr(ptrSize)) { + bv.append2(bitsScalar) + } + bv.append2(bitsPointer) + bv.append2(bitsPointer) + + case Array: + // repeat inner type + tt := (*arrayType)(unsafe.Pointer(t)) + for i := 0; i < int(tt.len); i++ { + addTypeBits(bv, offset, tt.elem) + } + + case Struct: + // apply fields + tt := (*structType)(unsafe.Pointer(t)) + start := *offset + for i := range tt.fields { + f := &tt.fields[i] + off := start + f.offset + addTypeBits(bv, &off, f.typ) + } + } + + *offset += t.size +} diff --git a/src/reflect/value.go b/src/reflect/value.go new file mode 100644 index 000000000..43843e963 --- /dev/null +++ b/src/reflect/value.go @@ -0,0 +1,2443 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package reflect + +import ( + "math" + "runtime" + "unsafe" +) + +const ptrSize = unsafe.Sizeof((*byte)(nil)) +const cannotSet = "cannot set value obtained from unexported struct field" + +// Value is the reflection interface to a Go value. +// +// Not all methods apply to all kinds of values. Restrictions, +// if any, are noted in the documentation for each method. +// Use the Kind method to find out the kind of value before +// calling kind-specific methods. Calling a method +// inappropriate to the kind of type causes a run time panic. +// +// The zero Value represents no value. +// Its IsValid method returns false, its Kind method returns Invalid, +// its String method returns "<invalid Value>", and all other methods panic. +// Most functions and methods never return an invalid value. +// If one does, its documentation states the conditions explicitly. +// +// A Value can be used concurrently by multiple goroutines provided that +// the underlying Go value can be used concurrently for the equivalent +// direct operations. +type Value struct { + // typ holds the type of the value represented by a Value. + typ *rtype + + // Pointer-valued data or, if flagIndir is set, pointer to data. + // Valid when either flagIndir is set or typ.pointers() is true. + ptr unsafe.Pointer + + // flag holds metadata about the value. + // The lowest bits are flag bits: + // - flagRO: obtained via unexported field, so read-only + // - flagIndir: val holds a pointer to the data + // - flagAddr: v.CanAddr is true (implies flagIndir) + // - flagMethod: v is a method value. + // The next five bits give the Kind of the value. + // This repeats typ.Kind() except for method values. + // The remaining 23+ bits give a method number for method values. + // If flag.kind() != Func, code can assume that flagMethod is unset. + // If ifaceIndir(typ), code can assume that flagIndir is set. + flag + + // A method value represents a curried method invocation + // like r.Read for some receiver r. The typ+val+flag bits describe + // the receiver r, but the flag's Kind bits say Func (methods are + // functions), and the top bits of the flag give the method number + // in r's type's method table. +} + +type flag uintptr + +const ( + flagKindWidth = 5 // there are 27 kinds + flagKindMask flag = 1<<flagKindWidth - 1 + flagRO flag = 1 << 5 + flagIndir flag = 1 << 6 + flagAddr flag = 1 << 7 + flagMethod flag = 1 << 8 + flagMethodShift = 9 +) + +func (f flag) kind() Kind { + return Kind(f & flagKindMask) +} + +// pointer returns the underlying pointer represented by v. +// v.Kind() must be Ptr, Map, Chan, Func, or UnsafePointer +func (v Value) pointer() unsafe.Pointer { + if v.typ.size != ptrSize || !v.typ.pointers() { + panic("can't call pointer on a non-pointer Value") + } + if v.flag&flagIndir != 0 { + return *(*unsafe.Pointer)(v.ptr) + } + return v.ptr +} + +// packEface converts v to the empty interface. +func packEface(v Value) interface{} { + t := v.typ + var i interface{} + e := (*emptyInterface)(unsafe.Pointer(&i)) + // First, fill in the data portion of the interface. + switch { + case ifaceIndir(t): + if v.flag&flagIndir == 0 { + panic("bad indir") + } + // Value is indirect, and so is the interface we're making. + ptr := v.ptr + if v.flag&flagAddr != 0 { + // TODO: pass safe boolean from valueInterface so + // we don't need to copy if safe==true? + c := unsafe_New(t) + memmove(c, ptr, t.size) + ptr = c + } + e.word = ptr + case v.flag&flagIndir != 0: + // Value is indirect, but interface is direct. We need + // to load the data at v.ptr into the interface data word. + e.word = *(*unsafe.Pointer)(v.ptr) + default: + // Value is direct, and so is the interface. + e.word = v.ptr + } + // Now, fill in the type portion. We're very careful here not + // to have any operation between the e.word and e.typ assignments + // that would let the garbage collector observe the partially-built + // interface value. + e.typ = t + return i +} + +// unpackEface converts the empty interface i to a Value. +func unpackEface(i interface{}) Value { + e := (*emptyInterface)(unsafe.Pointer(&i)) + // NOTE: don't read e.word until we know whether it is really a pointer or not. + t := e.typ + if t == nil { + return Value{} + } + f := flag(t.Kind()) + if ifaceIndir(t) { + f |= flagIndir + } + return Value{t, unsafe.Pointer(e.word), f} +} + +// A ValueError occurs when a Value method is invoked on +// a Value that does not support it. Such cases are documented +// in the description of each method. +type ValueError struct { + Method string + Kind Kind +} + +func (e *ValueError) Error() string { + if e.Kind == 0 { + return "reflect: call of " + e.Method + " on zero Value" + } + return "reflect: call of " + e.Method + " on " + e.Kind.String() + " Value" +} + +// methodName returns the name of the calling method, +// assumed to be two stack frames above. +func methodName() string { + pc, _, _, _ := runtime.Caller(2) + f := runtime.FuncForPC(pc) + if f == nil { + return "unknown method" + } + return f.Name() +} + +// emptyInterface is the header for an interface{} value. +type emptyInterface struct { + typ *rtype + word unsafe.Pointer +} + +// nonEmptyInterface is the header for a interface value with methods. +type nonEmptyInterface struct { + // see ../runtime/iface.c:/Itab + itab *struct { + ityp *rtype // static interface type + typ *rtype // dynamic concrete type + link unsafe.Pointer + bad int32 + unused int32 + fun [100000]unsafe.Pointer // method table + } + word unsafe.Pointer +} + +// mustBe panics if f's kind is not expected. +// Making this a method on flag instead of on Value +// (and embedding flag in Value) means that we can write +// the very clear v.mustBe(Bool) and have it compile into +// v.flag.mustBe(Bool), which will only bother to copy the +// single important word for the receiver. +func (f flag) mustBe(expected Kind) { + if f.kind() != expected { + panic(&ValueError{methodName(), f.kind()}) + } +} + +// mustBeExported panics if f records that the value was obtained using +// an unexported field. +func (f flag) mustBeExported() { + if f == 0 { + panic(&ValueError{methodName(), 0}) + } + if f&flagRO != 0 { + panic("reflect: " + methodName() + " using value obtained using unexported field") + } +} + +// mustBeAssignable panics if f records that the value is not assignable, +// which is to say that either it was obtained using an unexported field +// or it is not addressable. +func (f flag) mustBeAssignable() { + if f == 0 { + panic(&ValueError{methodName(), Invalid}) + } + // Assignable if addressable and not read-only. + if f&flagRO != 0 { + panic("reflect: " + methodName() + " using value obtained using unexported field") + } + if f&flagAddr == 0 { + panic("reflect: " + methodName() + " using unaddressable value") + } +} + +// Addr returns a pointer value representing the address of v. +// It panics if CanAddr() returns false. +// Addr is typically used to obtain a pointer to a struct field +// or slice element in order to call a method that requires a +// pointer receiver. +func (v Value) Addr() Value { + if v.flag&flagAddr == 0 { + panic("reflect.Value.Addr of unaddressable value") + } + return Value{v.typ.ptrTo(), v.ptr, (v.flag & flagRO) | flag(Ptr)} +} + +// Bool returns v's underlying value. +// It panics if v's kind is not Bool. +func (v Value) Bool() bool { + v.mustBe(Bool) + return *(*bool)(v.ptr) +} + +// Bytes returns v's underlying value. +// It panics if v's underlying value is not a slice of bytes. +func (v Value) Bytes() []byte { + v.mustBe(Slice) + if v.typ.Elem().Kind() != Uint8 { + panic("reflect.Value.Bytes of non-byte slice") + } + // Slice is always bigger than a word; assume flagIndir. + return *(*[]byte)(v.ptr) +} + +// runes returns v's underlying value. +// It panics if v's underlying value is not a slice of runes (int32s). +func (v Value) runes() []rune { + v.mustBe(Slice) + if v.typ.Elem().Kind() != Int32 { + panic("reflect.Value.Bytes of non-rune slice") + } + // Slice is always bigger than a word; assume flagIndir. + return *(*[]rune)(v.ptr) +} + +// CanAddr returns true if the value's address can be obtained with Addr. +// Such values are called addressable. A value is addressable if it is +// an element of a slice, an element of an addressable array, +// a field of an addressable struct, or the result of dereferencing a pointer. +// If CanAddr returns false, calling Addr will panic. +func (v Value) CanAddr() bool { + return v.flag&flagAddr != 0 +} + +// CanSet returns true if the value of v can be changed. +// A Value can be changed only if it is addressable and was not +// obtained by the use of unexported struct fields. +// If CanSet returns false, calling Set or any type-specific +// setter (e.g., SetBool, SetInt64) will panic. +func (v Value) CanSet() bool { + return v.flag&(flagAddr|flagRO) == flagAddr +} + +// Call calls the function v with the input arguments in. +// For example, if len(in) == 3, v.Call(in) represents the Go call v(in[0], in[1], in[2]). +// Call panics if v's Kind is not Func. +// It returns the output results as Values. +// As in Go, each input argument must be assignable to the +// type of the function's corresponding input parameter. +// If v is a variadic function, Call creates the variadic slice parameter +// itself, copying in the corresponding values. +func (v Value) Call(in []Value) []Value { + v.mustBe(Func) + v.mustBeExported() + return v.call("Call", in) +} + +// CallSlice calls the variadic function v with the input arguments in, +// assigning the slice in[len(in)-1] to v's final variadic argument. +// For example, if len(in) == 3, v.Call(in) represents the Go call v(in[0], in[1], in[2]...). +// Call panics if v's Kind is not Func or if v is not variadic. +// It returns the output results as Values. +// As in Go, each input argument must be assignable to the +// type of the function's corresponding input parameter. +func (v Value) CallSlice(in []Value) []Value { + v.mustBe(Func) + v.mustBeExported() + return v.call("CallSlice", in) +} + +var callGC bool // for testing; see TestCallMethodJump + +func (v Value) call(op string, in []Value) []Value { + // Get function pointer, type. + t := v.typ + var ( + fn unsafe.Pointer + rcvr Value + rcvrtype *rtype + ) + if v.flag&flagMethod != 0 { + rcvr = v + rcvrtype, t, fn = methodReceiver(op, v, int(v.flag)>>flagMethodShift) + } else if v.flag&flagIndir != 0 { + fn = *(*unsafe.Pointer)(v.ptr) + } else { + fn = v.ptr + } + + if fn == nil { + panic("reflect.Value.Call: call of nil function") + } + + isSlice := op == "CallSlice" + n := t.NumIn() + if isSlice { + if !t.IsVariadic() { + panic("reflect: CallSlice of non-variadic function") + } + if len(in) < n { + panic("reflect: CallSlice with too few input arguments") + } + if len(in) > n { + panic("reflect: CallSlice with too many input arguments") + } + } else { + if t.IsVariadic() { + n-- + } + if len(in) < n { + panic("reflect: Call with too few input arguments") + } + if !t.IsVariadic() && len(in) > n { + panic("reflect: Call with too many input arguments") + } + } + for _, x := range in { + if x.Kind() == Invalid { + panic("reflect: " + op + " using zero Value argument") + } + } + for i := 0; i < n; i++ { + if xt, targ := in[i].Type(), t.In(i); !xt.AssignableTo(targ) { + panic("reflect: " + op + " using " + xt.String() + " as type " + targ.String()) + } + } + if !isSlice && t.IsVariadic() { + // prepare slice for remaining values + m := len(in) - n + slice := MakeSlice(t.In(n), m, m) + elem := t.In(n).Elem() + for i := 0; i < m; i++ { + x := in[n+i] + if xt := x.Type(); !xt.AssignableTo(elem) { + panic("reflect: cannot use " + xt.String() + " as type " + elem.String() + " in " + op) + } + slice.Index(i).Set(x) + } + origIn := in + in = make([]Value, n+1) + copy(in[:n], origIn) + in[n] = slice + } + + nin := len(in) + if nin != t.NumIn() { + panic("reflect.Value.Call: wrong argument count") + } + nout := t.NumOut() + + // Compute frame type, allocate a chunk of memory for frame + frametype, _, retOffset, _ := funcLayout(t, rcvrtype) + args := unsafe_New(frametype) + off := uintptr(0) + + // Copy inputs into args. + if rcvrtype != nil { + storeRcvr(rcvr, args) + off = ptrSize + } + for i, v := range in { + v.mustBeExported() + targ := t.In(i).(*rtype) + a := uintptr(targ.align) + off = (off + a - 1) &^ (a - 1) + n := targ.size + addr := unsafe.Pointer(uintptr(args) + off) + v = v.assignTo("reflect.Value.Call", targ, addr) + if v.flag&flagIndir != 0 { + memmove(addr, v.ptr, n) + } else { + *(*unsafe.Pointer)(addr) = v.ptr + } + off += n + } + + // Call. + call(fn, args, uint32(frametype.size), uint32(retOffset)) + + // For testing; see TestCallMethodJump. + if callGC { + runtime.GC() + } + + // Copy return values out of args. + ret := make([]Value, nout) + off = retOffset + for i := 0; i < nout; i++ { + tv := t.Out(i) + a := uintptr(tv.Align()) + off = (off + a - 1) &^ (a - 1) + fl := flagIndir | flag(tv.Kind()) + ret[i] = Value{tv.common(), unsafe.Pointer(uintptr(args) + off), fl} + off += tv.Size() + } + + return ret +} + +// callReflect is the call implementation used by a function +// returned by MakeFunc. In many ways it is the opposite of the +// method Value.call above. The method above converts a call using Values +// into a call of a function with a concrete argument frame, while +// callReflect converts a call of a function with a concrete argument +// frame into a call using Values. +// It is in this file so that it can be next to the call method above. +// The remainder of the MakeFunc implementation is in makefunc.go. +// +// NOTE: This function must be marked as a "wrapper" in the generated code, +// so that the linker can make it work correctly for panic and recover. +// The gc compilers know to do that for the name "reflect.callReflect". +func callReflect(ctxt *makeFuncImpl, frame unsafe.Pointer) { + ftyp := ctxt.typ + f := ctxt.fn + + // Copy argument frame into Values. + ptr := frame + off := uintptr(0) + in := make([]Value, 0, len(ftyp.in)) + for _, arg := range ftyp.in { + typ := arg + off += -off & uintptr(typ.align-1) + addr := unsafe.Pointer(uintptr(ptr) + off) + v := Value{typ, nil, flag(typ.Kind())} + if ifaceIndir(typ) { + // value cannot be inlined in interface data. + // Must make a copy, because f might keep a reference to it, + // and we cannot let f keep a reference to the stack frame + // after this function returns, not even a read-only reference. + v.ptr = unsafe_New(typ) + memmove(v.ptr, addr, typ.size) + v.flag |= flagIndir + } else { + v.ptr = *(*unsafe.Pointer)(addr) + } + in = append(in, v) + off += typ.size + } + + // Call underlying function. + out := f(in) + if len(out) != len(ftyp.out) { + panic("reflect: wrong return count from function created by MakeFunc") + } + + // Copy results back into argument frame. + if len(ftyp.out) > 0 { + off += -off & (ptrSize - 1) + if runtime.GOARCH == "amd64p32" { + off = align(off, 8) + } + for i, arg := range ftyp.out { + typ := arg + v := out[i] + if v.typ != typ { + panic("reflect: function created by MakeFunc using " + funcName(f) + + " returned wrong type: have " + + out[i].typ.String() + " for " + typ.String()) + } + if v.flag&flagRO != 0 { + panic("reflect: function created by MakeFunc using " + funcName(f) + + " returned value obtained from unexported field") + } + off += -off & uintptr(typ.align-1) + addr := unsafe.Pointer(uintptr(ptr) + off) + if v.flag&flagIndir != 0 { + memmove(addr, v.ptr, typ.size) + } else { + *(*unsafe.Pointer)(addr) = v.ptr + } + off += typ.size + } + } +} + +// methodReceiver returns information about the receiver +// described by v. The Value v may or may not have the +// flagMethod bit set, so the kind cached in v.flag should +// not be used. +// The return value rcvrtype gives the method's actual receiver type. +// The return value t gives the method type signature (without the receiver). +// The return value fn is a pointer to the method code. +func methodReceiver(op string, v Value, methodIndex int) (rcvrtype, t *rtype, fn unsafe.Pointer) { + i := methodIndex + if v.typ.Kind() == Interface { + tt := (*interfaceType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(len(tt.methods)) { + panic("reflect: internal error: invalid method index") + } + m := &tt.methods[i] + if m.pkgPath != nil { + panic("reflect: " + op + " of unexported method") + } + iface := (*nonEmptyInterface)(v.ptr) + if iface.itab == nil { + panic("reflect: " + op + " of method on nil interface value") + } + rcvrtype = iface.itab.typ + fn = unsafe.Pointer(&iface.itab.fun[i]) + t = m.typ + } else { + rcvrtype = v.typ + ut := v.typ.uncommon() + if ut == nil || uint(i) >= uint(len(ut.methods)) { + panic("reflect: internal error: invalid method index") + } + m := &ut.methods[i] + if m.pkgPath != nil { + panic("reflect: " + op + " of unexported method") + } + fn = unsafe.Pointer(&m.ifn) + t = m.mtyp + } + return +} + +// v is a method receiver. Store at p the word which is used to +// encode that receiver at the start of the argument list. +// Reflect uses the "interface" calling convention for +// methods, which always uses one word to record the receiver. +func storeRcvr(v Value, p unsafe.Pointer) { + t := v.typ + if t.Kind() == Interface { + // the interface data word becomes the receiver word + iface := (*nonEmptyInterface)(v.ptr) + *(*unsafe.Pointer)(p) = unsafe.Pointer(iface.word) + } else if v.flag&flagIndir != 0 && !ifaceIndir(t) { + *(*unsafe.Pointer)(p) = *(*unsafe.Pointer)(v.ptr) + } else { + *(*unsafe.Pointer)(p) = v.ptr + } +} + +// align returns the result of rounding x up to a multiple of n. +// n must be a power of two. +func align(x, n uintptr) uintptr { + return (x + n - 1) &^ (n - 1) +} + +// callMethod is the call implementation used by a function returned +// by makeMethodValue (used by v.Method(i).Interface()). +// It is a streamlined version of the usual reflect call: the caller has +// already laid out the argument frame for us, so we don't have +// to deal with individual Values for each argument. +// It is in this file so that it can be next to the two similar functions above. +// The remainder of the makeMethodValue implementation is in makefunc.go. +// +// NOTE: This function must be marked as a "wrapper" in the generated code, +// so that the linker can make it work correctly for panic and recover. +// The gc compilers know to do that for the name "reflect.callMethod". +func callMethod(ctxt *methodValue, frame unsafe.Pointer) { + rcvr := ctxt.rcvr + rcvrtype, t, fn := methodReceiver("call", rcvr, ctxt.method) + frametype, argSize, retOffset, _ := funcLayout(t, rcvrtype) + + // Make a new frame that is one word bigger so we can store the receiver. + args := unsafe_New(frametype) + + // Copy in receiver and rest of args. + storeRcvr(rcvr, args) + memmove(unsafe.Pointer(uintptr(args)+ptrSize), frame, argSize-ptrSize) + + // Call. + call(fn, args, uint32(frametype.size), uint32(retOffset)) + + // Copy return values. On amd64p32, the beginning of return values + // is 64-bit aligned, so the caller's frame layout (which doesn't have + // a receiver) is different from the layout of the fn call, which has + // a receiver. + // Ignore any changes to args and just copy return values. + callerRetOffset := retOffset - ptrSize + if runtime.GOARCH == "amd64p32" { + callerRetOffset = align(argSize-ptrSize, 8) + } + memmove(unsafe.Pointer(uintptr(frame)+callerRetOffset), + unsafe.Pointer(uintptr(args)+retOffset), frametype.size-retOffset) +} + +// funcName returns the name of f, for use in error messages. +func funcName(f func([]Value) []Value) string { + pc := *(*uintptr)(unsafe.Pointer(&f)) + rf := runtime.FuncForPC(pc) + if rf != nil { + return rf.Name() + } + return "closure" +} + +// Cap returns v's capacity. +// It panics if v's Kind is not Array, Chan, or Slice. +func (v Value) Cap() int { + k := v.kind() + switch k { + case Array: + return v.typ.Len() + case Chan: + return int(chancap(v.pointer())) + case Slice: + // Slice is always bigger than a word; assume flagIndir. + return (*sliceHeader)(v.ptr).Cap + } + panic(&ValueError{"reflect.Value.Cap", v.kind()}) +} + +// Close closes the channel v. +// It panics if v's Kind is not Chan. +func (v Value) Close() { + v.mustBe(Chan) + v.mustBeExported() + chanclose(v.pointer()) +} + +// Complex returns v's underlying value, as a complex128. +// It panics if v's Kind is not Complex64 or Complex128 +func (v Value) Complex() complex128 { + k := v.kind() + switch k { + case Complex64: + return complex128(*(*complex64)(v.ptr)) + case Complex128: + return *(*complex128)(v.ptr) + } + panic(&ValueError{"reflect.Value.Complex", v.kind()}) +} + +// Elem returns the value that the interface v contains +// or that the pointer v points to. +// It panics if v's Kind is not Interface or Ptr. +// It returns the zero Value if v is nil. +func (v Value) Elem() Value { + k := v.kind() + switch k { + case Interface: + var eface interface{} + if v.typ.NumMethod() == 0 { + eface = *(*interface{})(v.ptr) + } else { + eface = (interface{})(*(*interface { + M() + })(v.ptr)) + } + x := unpackEface(eface) + if x.flag != 0 { + x.flag |= v.flag & flagRO + } + return x + case Ptr: + ptr := v.ptr + if v.flag&flagIndir != 0 { + ptr = *(*unsafe.Pointer)(ptr) + } + // The returned value's address is v's value. + if ptr == nil { + return Value{} + } + tt := (*ptrType)(unsafe.Pointer(v.typ)) + typ := tt.elem + fl := v.flag&flagRO | flagIndir | flagAddr + fl |= flag(typ.Kind()) + return Value{typ, ptr, fl} + } + panic(&ValueError{"reflect.Value.Elem", v.kind()}) +} + +// Field returns the i'th field of the struct v. +// It panics if v's Kind is not Struct or i is out of range. +func (v Value) Field(i int) Value { + if v.kind() != Struct { + panic(&ValueError{"reflect.Value.Field", v.kind()}) + } + tt := (*structType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(len(tt.fields)) { + panic("reflect: Field index out of range") + } + field := &tt.fields[i] + typ := field.typ + + // Inherit permission bits from v. + fl := v.flag&(flagRO|flagIndir|flagAddr) | flag(typ.Kind()) + // Using an unexported field forces flagRO. + if field.pkgPath != nil { + fl |= flagRO + } + // Either flagIndir is set and v.ptr points at struct, + // or flagIndir is not set and v.ptr is the actual struct data. + // In the former case, we want v.ptr + offset. + // In the latter case, we must be have field.offset = 0, + // so v.ptr + field.offset is still okay. + ptr := unsafe.Pointer(uintptr(v.ptr) + field.offset) + return Value{typ, ptr, fl} +} + +// FieldByIndex returns the nested field corresponding to index. +// It panics if v's Kind is not struct. +func (v Value) FieldByIndex(index []int) Value { + if len(index) == 1 { + return v.Field(index[0]) + } + v.mustBe(Struct) + for i, x := range index { + if i > 0 { + if v.Kind() == Ptr && v.typ.Elem().Kind() == Struct { + if v.IsNil() { + panic("reflect: indirection through nil pointer to embedded struct") + } + v = v.Elem() + } + } + v = v.Field(x) + } + return v +} + +// FieldByName returns the struct field with the given name. +// It returns the zero Value if no field was found. +// It panics if v's Kind is not struct. +func (v Value) FieldByName(name string) Value { + v.mustBe(Struct) + if f, ok := v.typ.FieldByName(name); ok { + return v.FieldByIndex(f.Index) + } + return Value{} +} + +// FieldByNameFunc returns the struct field with a name +// that satisfies the match function. +// It panics if v's Kind is not struct. +// It returns the zero Value if no field was found. +func (v Value) FieldByNameFunc(match func(string) bool) Value { + if f, ok := v.typ.FieldByNameFunc(match); ok { + return v.FieldByIndex(f.Index) + } + return Value{} +} + +// Float returns v's underlying value, as a float64. +// It panics if v's Kind is not Float32 or Float64 +func (v Value) Float() float64 { + k := v.kind() + switch k { + case Float32: + return float64(*(*float32)(v.ptr)) + case Float64: + return *(*float64)(v.ptr) + } + panic(&ValueError{"reflect.Value.Float", v.kind()}) +} + +var uint8Type = TypeOf(uint8(0)).(*rtype) + +// Index returns v's i'th element. +// It panics if v's Kind is not Array, Slice, or String or i is out of range. +func (v Value) Index(i int) Value { + switch v.kind() { + case Array: + tt := (*arrayType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(tt.len) { + panic("reflect: array index out of range") + } + typ := tt.elem + offset := uintptr(i) * typ.size + + // Either flagIndir is set and v.ptr points at array, + // or flagIndir is not set and v.ptr is the actual array data. + // In the former case, we want v.ptr + offset. + // In the latter case, we must be doing Index(0), so offset = 0, + // so v.ptr + offset is still okay. + val := unsafe.Pointer(uintptr(v.ptr) + offset) + fl := v.flag&(flagRO|flagIndir|flagAddr) | flag(typ.Kind()) // bits same as overall array + return Value{typ, val, fl} + + case Slice: + // Element flag same as Elem of Ptr. + // Addressable, indirect, possibly read-only. + s := (*sliceHeader)(v.ptr) + if uint(i) >= uint(s.Len) { + panic("reflect: slice index out of range") + } + tt := (*sliceType)(unsafe.Pointer(v.typ)) + typ := tt.elem + val := unsafe.Pointer(uintptr(s.Data) + uintptr(i)*typ.size) + fl := flagAddr | flagIndir | v.flag&flagRO | flag(typ.Kind()) + return Value{typ, val, fl} + + case String: + s := (*stringHeader)(v.ptr) + if uint(i) >= uint(s.Len) { + panic("reflect: string index out of range") + } + p := unsafe.Pointer(uintptr(s.Data) + uintptr(i)) + fl := v.flag&flagRO | flag(Uint8) | flagIndir + return Value{uint8Type, p, fl} + } + panic(&ValueError{"reflect.Value.Index", v.kind()}) +} + +// Int returns v's underlying value, as an int64. +// It panics if v's Kind is not Int, Int8, Int16, Int32, or Int64. +func (v Value) Int() int64 { + k := v.kind() + p := v.ptr + switch k { + case Int: + return int64(*(*int)(p)) + case Int8: + return int64(*(*int8)(p)) + case Int16: + return int64(*(*int16)(p)) + case Int32: + return int64(*(*int32)(p)) + case Int64: + return int64(*(*int64)(p)) + } + panic(&ValueError{"reflect.Value.Int", v.kind()}) +} + +// CanInterface returns true if Interface can be used without panicking. +func (v Value) CanInterface() bool { + if v.flag == 0 { + panic(&ValueError{"reflect.Value.CanInterface", Invalid}) + } + return v.flag&flagRO == 0 +} + +// Interface returns v's current value as an interface{}. +// It is equivalent to: +// var i interface{} = (v's underlying value) +// It panics if the Value was obtained by accessing +// unexported struct fields. +func (v Value) Interface() (i interface{}) { + return valueInterface(v, true) +} + +func valueInterface(v Value, safe bool) interface{} { + if v.flag == 0 { + panic(&ValueError{"reflect.Value.Interface", 0}) + } + if safe && v.flag&flagRO != 0 { + // Do not allow access to unexported values via Interface, + // because they might be pointers that should not be + // writable or methods or function that should not be callable. + panic("reflect.Value.Interface: cannot return value obtained from unexported field or method") + } + if v.flag&flagMethod != 0 { + v = makeMethodValue("Interface", v) + } + + if v.kind() == Interface { + // Special case: return the element inside the interface. + // Empty interface has one layout, all interfaces with + // methods have a second layout. + if v.NumMethod() == 0 { + return *(*interface{})(v.ptr) + } + return *(*interface { + M() + })(v.ptr) + } + + // TODO: pass safe to packEface so we don't need to copy if safe==true? + return packEface(v) +} + +// InterfaceData returns the interface v's value as a uintptr pair. +// It panics if v's Kind is not Interface. +func (v Value) InterfaceData() [2]uintptr { + // TODO: deprecate this + v.mustBe(Interface) + // We treat this as a read operation, so we allow + // it even for unexported data, because the caller + // has to import "unsafe" to turn it into something + // that can be abused. + // Interface value is always bigger than a word; assume flagIndir. + return *(*[2]uintptr)(v.ptr) +} + +// IsNil reports whether its argument v is nil. The argument must be +// a chan, func, interface, map, pointer, or slice value; if it is +// not, IsNil panics. Note that IsNil is not always equivalent to a +// regular comparison with nil in Go. For example, if v was created +// by calling ValueOf with an uninitialized interface variable i, +// i==nil will be true but v.IsNil will panic as v will be the zero +// Value. +func (v Value) IsNil() bool { + k := v.kind() + switch k { + case Chan, Func, Map, Ptr: + if v.flag&flagMethod != 0 { + return false + } + ptr := v.ptr + if v.flag&flagIndir != 0 { + ptr = *(*unsafe.Pointer)(ptr) + } + return ptr == nil + case Interface, Slice: + // Both interface and slice are nil if first word is 0. + // Both are always bigger than a word; assume flagIndir. + return *(*unsafe.Pointer)(v.ptr) == nil + } + panic(&ValueError{"reflect.Value.IsNil", v.kind()}) +} + +// IsValid returns true if v represents a value. +// It returns false if v is the zero Value. +// If IsValid returns false, all other methods except String panic. +// Most functions and methods never return an invalid value. +// If one does, its documentation states the conditions explicitly. +func (v Value) IsValid() bool { + return v.flag != 0 +} + +// Kind returns v's Kind. +// If v is the zero Value (IsValid returns false), Kind returns Invalid. +func (v Value) Kind() Kind { + return v.kind() +} + +// Len returns v's length. +// It panics if v's Kind is not Array, Chan, Map, Slice, or String. +func (v Value) Len() int { + k := v.kind() + switch k { + case Array: + tt := (*arrayType)(unsafe.Pointer(v.typ)) + return int(tt.len) + case Chan: + return chanlen(v.pointer()) + case Map: + return maplen(v.pointer()) + case Slice: + // Slice is bigger than a word; assume flagIndir. + return (*sliceHeader)(v.ptr).Len + case String: + // String is bigger than a word; assume flagIndir. + return (*stringHeader)(v.ptr).Len + } + panic(&ValueError{"reflect.Value.Len", v.kind()}) +} + +// MapIndex returns the value associated with key in the map v. +// It panics if v's Kind is not Map. +// It returns the zero Value if key is not found in the map or if v represents a nil map. +// As in Go, the key's value must be assignable to the map's key type. +func (v Value) MapIndex(key Value) Value { + v.mustBe(Map) + tt := (*mapType)(unsafe.Pointer(v.typ)) + + // Do not require key to be exported, so that DeepEqual + // and other programs can use all the keys returned by + // MapKeys as arguments to MapIndex. If either the map + // or the key is unexported, though, the result will be + // considered unexported. This is consistent with the + // behavior for structs, which allow read but not write + // of unexported fields. + key = key.assignTo("reflect.Value.MapIndex", tt.key, nil) + + var k unsafe.Pointer + if key.flag&flagIndir != 0 { + k = key.ptr + } else { + k = unsafe.Pointer(&key.ptr) + } + e := mapaccess(v.typ, v.pointer(), k) + if e == nil { + return Value{} + } + typ := tt.elem + fl := (v.flag | key.flag) & flagRO + fl |= flag(typ.Kind()) + if ifaceIndir(typ) { + // Copy result so future changes to the map + // won't change the underlying value. + c := unsafe_New(typ) + memmove(c, e, typ.size) + return Value{typ, c, fl | flagIndir} + } else { + return Value{typ, *(*unsafe.Pointer)(e), fl} + } +} + +// MapKeys returns a slice containing all the keys present in the map, +// in unspecified order. +// It panics if v's Kind is not Map. +// It returns an empty slice if v represents a nil map. +func (v Value) MapKeys() []Value { + v.mustBe(Map) + tt := (*mapType)(unsafe.Pointer(v.typ)) + keyType := tt.key + + fl := v.flag&flagRO | flag(keyType.Kind()) + + m := v.pointer() + mlen := int(0) + if m != nil { + mlen = maplen(m) + } + it := mapiterinit(v.typ, m) + a := make([]Value, mlen) + var i int + for i = 0; i < len(a); i++ { + key := mapiterkey(it) + if key == nil { + // Someone deleted an entry from the map since we + // called maplen above. It's a data race, but nothing + // we can do about it. + break + } + if ifaceIndir(keyType) { + // Copy result so future changes to the map + // won't change the underlying value. + c := unsafe_New(keyType) + memmove(c, key, keyType.size) + a[i] = Value{keyType, c, fl | flagIndir} + } else { + a[i] = Value{keyType, *(*unsafe.Pointer)(key), fl} + } + mapiternext(it) + } + return a[:i] +} + +// Method returns a function value corresponding to v's i'th method. +// The arguments to a Call on the returned function should not include +// a receiver; the returned function will always use v as the receiver. +// Method panics if i is out of range or if v is a nil interface value. +func (v Value) Method(i int) Value { + if v.typ == nil { + panic(&ValueError{"reflect.Value.Method", Invalid}) + } + if v.flag&flagMethod != 0 || uint(i) >= uint(v.typ.NumMethod()) { + panic("reflect: Method index out of range") + } + if v.typ.Kind() == Interface && v.IsNil() { + panic("reflect: Method on nil interface value") + } + fl := v.flag & (flagRO | flagIndir) + fl |= flag(Func) + fl |= flag(i)<<flagMethodShift | flagMethod + return Value{v.typ, v.ptr, fl} +} + +// NumMethod returns the number of methods in the value's method set. +func (v Value) NumMethod() int { + if v.typ == nil { + panic(&ValueError{"reflect.Value.NumMethod", Invalid}) + } + if v.flag&flagMethod != 0 { + return 0 + } + return v.typ.NumMethod() +} + +// MethodByName returns a function value corresponding to the method +// of v with the given name. +// The arguments to a Call on the returned function should not include +// a receiver; the returned function will always use v as the receiver. +// It returns the zero Value if no method was found. +func (v Value) MethodByName(name string) Value { + if v.typ == nil { + panic(&ValueError{"reflect.Value.MethodByName", Invalid}) + } + if v.flag&flagMethod != 0 { + return Value{} + } + m, ok := v.typ.MethodByName(name) + if !ok { + return Value{} + } + return v.Method(m.Index) +} + +// NumField returns the number of fields in the struct v. +// It panics if v's Kind is not Struct. +func (v Value) NumField() int { + v.mustBe(Struct) + tt := (*structType)(unsafe.Pointer(v.typ)) + return len(tt.fields) +} + +// OverflowComplex returns true if the complex128 x cannot be represented by v's type. +// It panics if v's Kind is not Complex64 or Complex128. +func (v Value) OverflowComplex(x complex128) bool { + k := v.kind() + switch k { + case Complex64: + return overflowFloat32(real(x)) || overflowFloat32(imag(x)) + case Complex128: + return false + } + panic(&ValueError{"reflect.Value.OverflowComplex", v.kind()}) +} + +// OverflowFloat returns true if the float64 x cannot be represented by v's type. +// It panics if v's Kind is not Float32 or Float64. +func (v Value) OverflowFloat(x float64) bool { + k := v.kind() + switch k { + case Float32: + return overflowFloat32(x) + case Float64: + return false + } + panic(&ValueError{"reflect.Value.OverflowFloat", v.kind()}) +} + +func overflowFloat32(x float64) bool { + if x < 0 { + x = -x + } + return math.MaxFloat32 < x && x <= math.MaxFloat64 +} + +// OverflowInt returns true if the int64 x cannot be represented by v's type. +// It panics if v's Kind is not Int, Int8, int16, Int32, or Int64. +func (v Value) OverflowInt(x int64) bool { + k := v.kind() + switch k { + case Int, Int8, Int16, Int32, Int64: + bitSize := v.typ.size * 8 + trunc := (x << (64 - bitSize)) >> (64 - bitSize) + return x != trunc + } + panic(&ValueError{"reflect.Value.OverflowInt", v.kind()}) +} + +// OverflowUint returns true if the uint64 x cannot be represented by v's type. +// It panics if v's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64. +func (v Value) OverflowUint(x uint64) bool { + k := v.kind() + switch k { + case Uint, Uintptr, Uint8, Uint16, Uint32, Uint64: + bitSize := v.typ.size * 8 + trunc := (x << (64 - bitSize)) >> (64 - bitSize) + return x != trunc + } + panic(&ValueError{"reflect.Value.OverflowUint", v.kind()}) +} + +// Pointer returns v's value as a uintptr. +// It returns uintptr instead of unsafe.Pointer so that +// code using reflect cannot obtain unsafe.Pointers +// without importing the unsafe package explicitly. +// It panics if v's Kind is not Chan, Func, Map, Ptr, Slice, or UnsafePointer. +// +// If v's Kind is Func, the returned pointer is an underlying +// code pointer, but not necessarily enough to identify a +// single function uniquely. The only guarantee is that the +// result is zero if and only if v is a nil func Value. +// +// If v's Kind is Slice, the returned pointer is to the first +// element of the slice. If the slice is nil the returned value +// is 0. If the slice is empty but non-nil the return value is non-zero. +func (v Value) Pointer() uintptr { + // TODO: deprecate + k := v.kind() + switch k { + case Chan, Map, Ptr, UnsafePointer: + return uintptr(v.pointer()) + case Func: + if v.flag&flagMethod != 0 { + // As the doc comment says, the returned pointer is an + // underlying code pointer but not necessarily enough to + // identify a single function uniquely. All method expressions + // created via reflect have the same underlying code pointer, + // so their Pointers are equal. The function used here must + // match the one used in makeMethodValue. + f := methodValueCall + return **(**uintptr)(unsafe.Pointer(&f)) + } + p := v.pointer() + // Non-nil func value points at data block. + // First word of data block is actual code. + if p != nil { + p = *(*unsafe.Pointer)(p) + } + return uintptr(p) + + case Slice: + return (*SliceHeader)(v.ptr).Data + } + panic(&ValueError{"reflect.Value.Pointer", v.kind()}) +} + +// Recv receives and returns a value from the channel v. +// It panics if v's Kind is not Chan. +// The receive blocks until a value is ready. +// The boolean value ok is true if the value x corresponds to a send +// on the channel, false if it is a zero value received because the channel is closed. +func (v Value) Recv() (x Value, ok bool) { + v.mustBe(Chan) + v.mustBeExported() + return v.recv(false) +} + +// internal recv, possibly non-blocking (nb). +// v is known to be a channel. +func (v Value) recv(nb bool) (val Value, ok bool) { + tt := (*chanType)(unsafe.Pointer(v.typ)) + if ChanDir(tt.dir)&RecvDir == 0 { + panic("reflect: recv on send-only channel") + } + t := tt.elem + val = Value{t, nil, flag(t.Kind())} + var p unsafe.Pointer + if ifaceIndir(t) { + p = unsafe_New(t) + val.ptr = p + val.flag |= flagIndir + } else { + p = unsafe.Pointer(&val.ptr) + } + selected, ok := chanrecv(v.typ, v.pointer(), nb, p) + if !selected { + val = Value{} + } + return +} + +// Send sends x on the channel v. +// It panics if v's kind is not Chan or if x's type is not the same type as v's element type. +// As in Go, x's value must be assignable to the channel's element type. +func (v Value) Send(x Value) { + v.mustBe(Chan) + v.mustBeExported() + v.send(x, false) +} + +// internal send, possibly non-blocking. +// v is known to be a channel. +func (v Value) send(x Value, nb bool) (selected bool) { + tt := (*chanType)(unsafe.Pointer(v.typ)) + if ChanDir(tt.dir)&SendDir == 0 { + panic("reflect: send on recv-only channel") + } + x.mustBeExported() + x = x.assignTo("reflect.Value.Send", tt.elem, nil) + var p unsafe.Pointer + if x.flag&flagIndir != 0 { + p = x.ptr + } else { + p = unsafe.Pointer(&x.ptr) + } + return chansend(v.typ, v.pointer(), p, nb) +} + +// Set assigns x to the value v. +// It panics if CanSet returns false. +// As in Go, x's value must be assignable to v's type. +func (v Value) Set(x Value) { + v.mustBeAssignable() + x.mustBeExported() // do not let unexported x leak + var target unsafe.Pointer + if v.kind() == Interface { + target = v.ptr + } + x = x.assignTo("reflect.Set", v.typ, target) + if x.flag&flagIndir != 0 { + memmove(v.ptr, x.ptr, v.typ.size) + } else { + *(*unsafe.Pointer)(v.ptr) = x.ptr + } +} + +// SetBool sets v's underlying value. +// It panics if v's Kind is not Bool or if CanSet() is false. +func (v Value) SetBool(x bool) { + v.mustBeAssignable() + v.mustBe(Bool) + *(*bool)(v.ptr) = x +} + +// SetBytes sets v's underlying value. +// It panics if v's underlying value is not a slice of bytes. +func (v Value) SetBytes(x []byte) { + v.mustBeAssignable() + v.mustBe(Slice) + if v.typ.Elem().Kind() != Uint8 { + panic("reflect.Value.SetBytes of non-byte slice") + } + *(*[]byte)(v.ptr) = x +} + +// setRunes sets v's underlying value. +// It panics if v's underlying value is not a slice of runes (int32s). +func (v Value) setRunes(x []rune) { + v.mustBeAssignable() + v.mustBe(Slice) + if v.typ.Elem().Kind() != Int32 { + panic("reflect.Value.setRunes of non-rune slice") + } + *(*[]rune)(v.ptr) = x +} + +// SetComplex sets v's underlying value to x. +// It panics if v's Kind is not Complex64 or Complex128, or if CanSet() is false. +func (v Value) SetComplex(x complex128) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetComplex", v.kind()}) + case Complex64: + *(*complex64)(v.ptr) = complex64(x) + case Complex128: + *(*complex128)(v.ptr) = x + } +} + +// SetFloat sets v's underlying value to x. +// It panics if v's Kind is not Float32 or Float64, or if CanSet() is false. +func (v Value) SetFloat(x float64) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetFloat", v.kind()}) + case Float32: + *(*float32)(v.ptr) = float32(x) + case Float64: + *(*float64)(v.ptr) = x + } +} + +// SetInt sets v's underlying value to x. +// It panics if v's Kind is not Int, Int8, Int16, Int32, or Int64, or if CanSet() is false. +func (v Value) SetInt(x int64) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetInt", v.kind()}) + case Int: + *(*int)(v.ptr) = int(x) + case Int8: + *(*int8)(v.ptr) = int8(x) + case Int16: + *(*int16)(v.ptr) = int16(x) + case Int32: + *(*int32)(v.ptr) = int32(x) + case Int64: + *(*int64)(v.ptr) = x + } +} + +// SetLen sets v's length to n. +// It panics if v's Kind is not Slice or if n is negative or +// greater than the capacity of the slice. +func (v Value) SetLen(n int) { + v.mustBeAssignable() + v.mustBe(Slice) + s := (*sliceHeader)(v.ptr) + if uint(n) > uint(s.Cap) { + panic("reflect: slice length out of range in SetLen") + } + s.Len = n +} + +// SetCap sets v's capacity to n. +// It panics if v's Kind is not Slice or if n is smaller than the length or +// greater than the capacity of the slice. +func (v Value) SetCap(n int) { + v.mustBeAssignable() + v.mustBe(Slice) + s := (*sliceHeader)(v.ptr) + if n < int(s.Len) || n > int(s.Cap) { + panic("reflect: slice capacity out of range in SetCap") + } + s.Cap = n +} + +// SetMapIndex sets the value associated with key in the map v to val. +// It panics if v's Kind is not Map. +// If val is the zero Value, SetMapIndex deletes the key from the map. +// Otherwise if v holds a nil map, SetMapIndex will panic. +// As in Go, key's value must be assignable to the map's key type, +// and val's value must be assignable to the map's value type. +func (v Value) SetMapIndex(key, val Value) { + v.mustBe(Map) + v.mustBeExported() + key.mustBeExported() + tt := (*mapType)(unsafe.Pointer(v.typ)) + key = key.assignTo("reflect.Value.SetMapIndex", tt.key, nil) + var k unsafe.Pointer + if key.flag&flagIndir != 0 { + k = key.ptr + } else { + k = unsafe.Pointer(&key.ptr) + } + if val.typ == nil { + mapdelete(v.typ, v.pointer(), k) + return + } + val.mustBeExported() + val = val.assignTo("reflect.Value.SetMapIndex", tt.elem, nil) + var e unsafe.Pointer + if val.flag&flagIndir != 0 { + e = val.ptr + } else { + e = unsafe.Pointer(&val.ptr) + } + mapassign(v.typ, v.pointer(), k, e) +} + +// SetUint sets v's underlying value to x. +// It panics if v's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64, or if CanSet() is false. +func (v Value) SetUint(x uint64) { + v.mustBeAssignable() + switch k := v.kind(); k { + default: + panic(&ValueError{"reflect.Value.SetUint", v.kind()}) + case Uint: + *(*uint)(v.ptr) = uint(x) + case Uint8: + *(*uint8)(v.ptr) = uint8(x) + case Uint16: + *(*uint16)(v.ptr) = uint16(x) + case Uint32: + *(*uint32)(v.ptr) = uint32(x) + case Uint64: + *(*uint64)(v.ptr) = x + case Uintptr: + *(*uintptr)(v.ptr) = uintptr(x) + } +} + +// SetPointer sets the unsafe.Pointer value v to x. +// It panics if v's Kind is not UnsafePointer. +func (v Value) SetPointer(x unsafe.Pointer) { + v.mustBeAssignable() + v.mustBe(UnsafePointer) + *(*unsafe.Pointer)(v.ptr) = x +} + +// SetString sets v's underlying value to x. +// It panics if v's Kind is not String or if CanSet() is false. +func (v Value) SetString(x string) { + v.mustBeAssignable() + v.mustBe(String) + *(*string)(v.ptr) = x +} + +// Slice returns v[i:j]. +// It panics if v's Kind is not Array, Slice or String, or if v is an unaddressable array, +// or if the indexes are out of bounds. +func (v Value) Slice(i, j int) Value { + var ( + cap int + typ *sliceType + base unsafe.Pointer + ) + switch kind := v.kind(); kind { + default: + panic(&ValueError{"reflect.Value.Slice", v.kind()}) + + case Array: + if v.flag&flagAddr == 0 { + panic("reflect.Value.Slice: slice of unaddressable array") + } + tt := (*arrayType)(unsafe.Pointer(v.typ)) + cap = int(tt.len) + typ = (*sliceType)(unsafe.Pointer(tt.slice)) + base = v.ptr + + case Slice: + typ = (*sliceType)(unsafe.Pointer(v.typ)) + s := (*sliceHeader)(v.ptr) + base = unsafe.Pointer(s.Data) + cap = s.Cap + + case String: + s := (*stringHeader)(v.ptr) + if i < 0 || j < i || j > s.Len { + panic("reflect.Value.Slice: string slice index out of bounds") + } + t := stringHeader{unsafe.Pointer(uintptr(s.Data) + uintptr(i)), j - i} + return Value{v.typ, unsafe.Pointer(&t), v.flag} + } + + if i < 0 || j < i || j > cap { + panic("reflect.Value.Slice: slice index out of bounds") + } + + // Declare slice so that gc can see the base pointer in it. + var x []unsafe.Pointer + + // Reinterpret as *sliceHeader to edit. + s := (*sliceHeader)(unsafe.Pointer(&x)) + s.Len = j - i + s.Cap = cap - i + if cap-i > 0 { + s.Data = unsafe.Pointer(uintptr(base) + uintptr(i)*typ.elem.Size()) + } else { + // do not advance pointer, to avoid pointing beyond end of slice + s.Data = base + } + + fl := v.flag&flagRO | flagIndir | flag(Slice) + return Value{typ.common(), unsafe.Pointer(&x), fl} +} + +// Slice3 is the 3-index form of the slice operation: it returns v[i:j:k]. +// It panics if v's Kind is not Array or Slice, or if v is an unaddressable array, +// or if the indexes are out of bounds. +func (v Value) Slice3(i, j, k int) Value { + var ( + cap int + typ *sliceType + base unsafe.Pointer + ) + switch kind := v.kind(); kind { + default: + panic(&ValueError{"reflect.Value.Slice3", v.kind()}) + + case Array: + if v.flag&flagAddr == 0 { + panic("reflect.Value.Slice3: slice of unaddressable array") + } + tt := (*arrayType)(unsafe.Pointer(v.typ)) + cap = int(tt.len) + typ = (*sliceType)(unsafe.Pointer(tt.slice)) + base = v.ptr + + case Slice: + typ = (*sliceType)(unsafe.Pointer(v.typ)) + s := (*sliceHeader)(v.ptr) + base = s.Data + cap = s.Cap + } + + if i < 0 || j < i || k < j || k > cap { + panic("reflect.Value.Slice3: slice index out of bounds") + } + + // Declare slice so that the garbage collector + // can see the base pointer in it. + var x []unsafe.Pointer + + // Reinterpret as *sliceHeader to edit. + s := (*sliceHeader)(unsafe.Pointer(&x)) + s.Len = j - i + s.Cap = k - i + if k-i > 0 { + s.Data = unsafe.Pointer(uintptr(base) + uintptr(i)*typ.elem.Size()) + } else { + // do not advance pointer, to avoid pointing beyond end of slice + s.Data = base + } + + fl := v.flag&flagRO | flagIndir | flag(Slice) + return Value{typ.common(), unsafe.Pointer(&x), fl} +} + +// String returns the string v's underlying value, as a string. +// String is a special case because of Go's String method convention. +// Unlike the other getters, it does not panic if v's Kind is not String. +// Instead, it returns a string of the form "<T value>" where T is v's type. +func (v Value) String() string { + switch k := v.kind(); k { + case Invalid: + return "<invalid Value>" + case String: + return *(*string)(v.ptr) + } + // If you call String on a reflect.Value of other type, it's better to + // print something than to panic. Useful in debugging. + return "<" + v.Type().String() + " Value>" +} + +// TryRecv attempts to receive a value from the channel v but will not block. +// It panics if v's Kind is not Chan. +// If the receive delivers a value, x is the transferred value and ok is true. +// If the receive cannot finish without blocking, x is the zero Value and ok is false. +// If the channel is closed, x is the zero value for the channel's element type and ok is false. +func (v Value) TryRecv() (x Value, ok bool) { + v.mustBe(Chan) + v.mustBeExported() + return v.recv(true) +} + +// TrySend attempts to send x on the channel v but will not block. +// It panics if v's Kind is not Chan. +// It returns true if the value was sent, false otherwise. +// As in Go, x's value must be assignable to the channel's element type. +func (v Value) TrySend(x Value) bool { + v.mustBe(Chan) + v.mustBeExported() + return v.send(x, true) +} + +// Type returns v's type. +func (v Value) Type() Type { + f := v.flag + if f == 0 { + panic(&ValueError{"reflect.Value.Type", Invalid}) + } + if f&flagMethod == 0 { + // Easy case + return v.typ + } + + // Method value. + // v.typ describes the receiver, not the method type. + i := int(v.flag) >> flagMethodShift + if v.typ.Kind() == Interface { + // Method on interface. + tt := (*interfaceType)(unsafe.Pointer(v.typ)) + if uint(i) >= uint(len(tt.methods)) { + panic("reflect: internal error: invalid method index") + } + m := &tt.methods[i] + return m.typ + } + // Method on concrete type. + ut := v.typ.uncommon() + if ut == nil || uint(i) >= uint(len(ut.methods)) { + panic("reflect: internal error: invalid method index") + } + m := &ut.methods[i] + return m.mtyp +} + +// Uint returns v's underlying value, as a uint64. +// It panics if v's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64. +func (v Value) Uint() uint64 { + k := v.kind() + p := v.ptr + switch k { + case Uint: + return uint64(*(*uint)(p)) + case Uint8: + return uint64(*(*uint8)(p)) + case Uint16: + return uint64(*(*uint16)(p)) + case Uint32: + return uint64(*(*uint32)(p)) + case Uint64: + return uint64(*(*uint64)(p)) + case Uintptr: + return uint64(*(*uintptr)(p)) + } + panic(&ValueError{"reflect.Value.Uint", v.kind()}) +} + +// UnsafeAddr returns a pointer to v's data. +// It is for advanced clients that also import the "unsafe" package. +// It panics if v is not addressable. +func (v Value) UnsafeAddr() uintptr { + // TODO: deprecate + if v.typ == nil { + panic(&ValueError{"reflect.Value.UnsafeAddr", Invalid}) + } + if v.flag&flagAddr == 0 { + panic("reflect.Value.UnsafeAddr of unaddressable value") + } + return uintptr(v.ptr) +} + +// StringHeader is the runtime representation of a string. +// It cannot be used safely or portably and its representation may +// change in a later release. +// Moreover, the Data field is not sufficient to guarantee the data +// it references will not be garbage collected, so programs must keep +// a separate, correctly typed pointer to the underlying data. +type StringHeader struct { + Data uintptr + Len int +} + +// stringHeader is a safe version of StringHeader used within this package. +type stringHeader struct { + Data unsafe.Pointer + Len int +} + +// SliceHeader is the runtime representation of a slice. +// It cannot be used safely or portably and its representation may +// change in a later release. +// Moreover, the Data field is not sufficient to guarantee the data +// it references will not be garbage collected, so programs must keep +// a separate, correctly typed pointer to the underlying data. +type SliceHeader struct { + Data uintptr + Len int + Cap int +} + +// sliceHeader is a safe version of SliceHeader used within this package. +type sliceHeader struct { + Data unsafe.Pointer + Len int + Cap int +} + +func typesMustMatch(what string, t1, t2 Type) { + if t1 != t2 { + panic(what + ": " + t1.String() + " != " + t2.String()) + } +} + +// grow grows the slice s so that it can hold extra more values, allocating +// more capacity if needed. It also returns the old and new slice lengths. +func grow(s Value, extra int) (Value, int, int) { + i0 := s.Len() + i1 := i0 + extra + if i1 < i0 { + panic("reflect.Append: slice overflow") + } + m := s.Cap() + if i1 <= m { + return s.Slice(0, i1), i0, i1 + } + if m == 0 { + m = extra + } else { + for m < i1 { + if i0 < 1024 { + m += m + } else { + m += m / 4 + } + } + } + t := MakeSlice(s.Type(), i1, m) + Copy(t, s) + return t, i0, i1 +} + +// Append appends the values x to a slice s and returns the resulting slice. +// As in Go, each x's value must be assignable to the slice's element type. +func Append(s Value, x ...Value) Value { + s.mustBe(Slice) + s, i0, i1 := grow(s, len(x)) + for i, j := i0, 0; i < i1; i, j = i+1, j+1 { + s.Index(i).Set(x[j]) + } + return s +} + +// AppendSlice appends a slice t to a slice s and returns the resulting slice. +// The slices s and t must have the same element type. +func AppendSlice(s, t Value) Value { + s.mustBe(Slice) + t.mustBe(Slice) + typesMustMatch("reflect.AppendSlice", s.Type().Elem(), t.Type().Elem()) + s, i0, i1 := grow(s, t.Len()) + Copy(s.Slice(i0, i1), t) + return s +} + +// Copy copies the contents of src into dst until either +// dst has been filled or src has been exhausted. +// It returns the number of elements copied. +// Dst and src each must have kind Slice or Array, and +// dst and src must have the same element type. +func Copy(dst, src Value) int { + dk := dst.kind() + if dk != Array && dk != Slice { + panic(&ValueError{"reflect.Copy", dk}) + } + if dk == Array { + dst.mustBeAssignable() + } + dst.mustBeExported() + + sk := src.kind() + if sk != Array && sk != Slice { + panic(&ValueError{"reflect.Copy", sk}) + } + src.mustBeExported() + + de := dst.typ.Elem() + se := src.typ.Elem() + typesMustMatch("reflect.Copy", de, se) + + n := dst.Len() + if sn := src.Len(); n > sn { + n = sn + } + + // Copy via memmove. + var da, sa unsafe.Pointer + if dk == Array { + da = dst.ptr + } else { + da = (*sliceHeader)(dst.ptr).Data + } + if src.flag&flagIndir == 0 { + sa = unsafe.Pointer(&src.ptr) + } else if sk == Array { + sa = src.ptr + } else { + sa = (*sliceHeader)(src.ptr).Data + } + memmove(da, sa, uintptr(n)*de.Size()) + return n +} + +// A runtimeSelect is a single case passed to rselect. +// This must match ../runtime/select.go:/runtimeSelect +type runtimeSelect struct { + dir uintptr // 0, SendDir, or RecvDir + typ *rtype // channel type + ch unsafe.Pointer // channel + val unsafe.Pointer // ptr to data (SendDir) or ptr to receive buffer (RecvDir) +} + +// rselect runs a select. It returns the index of the chosen case. +// If the case was a receive, val is filled in with the received value. +// The conventional OK bool indicates whether the receive corresponds +// to a sent value. +//go:noescape +func rselect([]runtimeSelect) (chosen int, recvOK bool) + +// A SelectDir describes the communication direction of a select case. +type SelectDir int + +// NOTE: These values must match ../runtime/select.go:/selectDir. + +const ( + _ SelectDir = iota + SelectSend // case Chan <- Send + SelectRecv // case <-Chan: + SelectDefault // default +) + +// A SelectCase describes a single case in a select operation. +// The kind of case depends on Dir, the communication direction. +// +// If Dir is SelectDefault, the case represents a default case. +// Chan and Send must be zero Values. +// +// If Dir is SelectSend, the case represents a send operation. +// Normally Chan's underlying value must be a channel, and Send's underlying value must be +// assignable to the channel's element type. As a special case, if Chan is a zero Value, +// then the case is ignored, and the field Send will also be ignored and may be either zero +// or non-zero. +// +// If Dir is SelectRecv, the case represents a receive operation. +// Normally Chan's underlying value must be a channel and Send must be a zero Value. +// If Chan is a zero Value, then the case is ignored, but Send must still be a zero Value. +// When a receive operation is selected, the received Value is returned by Select. +// +type SelectCase struct { + Dir SelectDir // direction of case + Chan Value // channel to use (for send or receive) + Send Value // value to send (for send) +} + +// Select executes a select operation described by the list of cases. +// Like the Go select statement, it blocks until at least one of the cases +// can proceed, makes a uniform pseudo-random choice, +// and then executes that case. It returns the index of the chosen case +// and, if that case was a receive operation, the value received and a +// boolean indicating whether the value corresponds to a send on the channel +// (as opposed to a zero value received because the channel is closed). +func Select(cases []SelectCase) (chosen int, recv Value, recvOK bool) { + // NOTE: Do not trust that caller is not modifying cases data underfoot. + // The range is safe because the caller cannot modify our copy of the len + // and each iteration makes its own copy of the value c. + runcases := make([]runtimeSelect, len(cases)) + haveDefault := false + for i, c := range cases { + rc := &runcases[i] + rc.dir = uintptr(c.Dir) + switch c.Dir { + default: + panic("reflect.Select: invalid Dir") + + case SelectDefault: // default + if haveDefault { + panic("reflect.Select: multiple default cases") + } + haveDefault = true + if c.Chan.IsValid() { + panic("reflect.Select: default case has Chan value") + } + if c.Send.IsValid() { + panic("reflect.Select: default case has Send value") + } + + case SelectSend: + ch := c.Chan + if !ch.IsValid() { + break + } + ch.mustBe(Chan) + ch.mustBeExported() + tt := (*chanType)(unsafe.Pointer(ch.typ)) + if ChanDir(tt.dir)&SendDir == 0 { + panic("reflect.Select: SendDir case using recv-only channel") + } + rc.ch = ch.pointer() + rc.typ = &tt.rtype + v := c.Send + if !v.IsValid() { + panic("reflect.Select: SendDir case missing Send value") + } + v.mustBeExported() + v = v.assignTo("reflect.Select", tt.elem, nil) + if v.flag&flagIndir != 0 { + rc.val = v.ptr + } else { + rc.val = unsafe.Pointer(&v.ptr) + } + + case SelectRecv: + if c.Send.IsValid() { + panic("reflect.Select: RecvDir case has Send value") + } + ch := c.Chan + if !ch.IsValid() { + break + } + ch.mustBe(Chan) + ch.mustBeExported() + tt := (*chanType)(unsafe.Pointer(ch.typ)) + if ChanDir(tt.dir)&RecvDir == 0 { + panic("reflect.Select: RecvDir case using send-only channel") + } + rc.ch = ch.pointer() + rc.typ = &tt.rtype + rc.val = unsafe_New(tt.elem) + } + } + + chosen, recvOK = rselect(runcases) + if runcases[chosen].dir == uintptr(SelectRecv) { + tt := (*chanType)(unsafe.Pointer(runcases[chosen].typ)) + t := tt.elem + p := runcases[chosen].val + fl := flag(t.Kind()) + if ifaceIndir(t) { + recv = Value{t, p, fl | flagIndir} + } else { + recv = Value{t, *(*unsafe.Pointer)(p), fl} + } + } + return chosen, recv, recvOK +} + +/* + * constructors + */ + +// implemented in package runtime +func unsafe_New(*rtype) unsafe.Pointer +func unsafe_NewArray(*rtype, int) unsafe.Pointer + +// MakeSlice creates a new zero-initialized slice value +// for the specified slice type, length, and capacity. +func MakeSlice(typ Type, len, cap int) Value { + if typ.Kind() != Slice { + panic("reflect.MakeSlice of non-slice type") + } + if len < 0 { + panic("reflect.MakeSlice: negative len") + } + if cap < 0 { + panic("reflect.MakeSlice: negative cap") + } + if len > cap { + panic("reflect.MakeSlice: len > cap") + } + + s := sliceHeader{unsafe_NewArray(typ.Elem().(*rtype), cap), len, cap} + return Value{typ.common(), unsafe.Pointer(&s), flagIndir | flag(Slice)} +} + +// MakeChan creates a new channel with the specified type and buffer size. +func MakeChan(typ Type, buffer int) Value { + if typ.Kind() != Chan { + panic("reflect.MakeChan of non-chan type") + } + if buffer < 0 { + panic("reflect.MakeChan: negative buffer size") + } + if typ.ChanDir() != BothDir { + panic("reflect.MakeChan: unidirectional channel type") + } + ch := makechan(typ.(*rtype), uint64(buffer)) + return Value{typ.common(), ch, flag(Chan)} +} + +// MakeMap creates a new map of the specified type. +func MakeMap(typ Type) Value { + if typ.Kind() != Map { + panic("reflect.MakeMap of non-map type") + } + m := makemap(typ.(*rtype)) + return Value{typ.common(), m, flag(Map)} +} + +// Indirect returns the value that v points to. +// If v is a nil pointer, Indirect returns a zero Value. +// If v is not a pointer, Indirect returns v. +func Indirect(v Value) Value { + if v.Kind() != Ptr { + return v + } + return v.Elem() +} + +// ValueOf returns a new Value initialized to the concrete value +// stored in the interface i. ValueOf(nil) returns the zero Value. +func ValueOf(i interface{}) Value { + if i == nil { + return Value{} + } + + // TODO(rsc): Eliminate this terrible hack. + // In the call to unpackEface, i.typ doesn't escape, + // and i.word is an integer. So it looks like + // i doesn't escape. But really it does, + // because i.word is actually a pointer. + escapes(i) + + return unpackEface(i) +} + +// Zero returns a Value representing the zero value for the specified type. +// The result is different from the zero value of the Value struct, +// which represents no value at all. +// For example, Zero(TypeOf(42)) returns a Value with Kind Int and value 0. +// The returned value is neither addressable nor settable. +func Zero(typ Type) Value { + if typ == nil { + panic("reflect: Zero(nil)") + } + t := typ.common() + fl := flag(t.Kind()) + if ifaceIndir(t) { + return Value{t, unsafe_New(typ.(*rtype)), fl | flagIndir} + } + return Value{t, nil, fl} +} + +// New returns a Value representing a pointer to a new zero value +// for the specified type. That is, the returned Value's Type is PtrTo(typ). +func New(typ Type) Value { + if typ == nil { + panic("reflect: New(nil)") + } + ptr := unsafe_New(typ.(*rtype)) + fl := flag(Ptr) + return Value{typ.common().ptrTo(), ptr, fl} +} + +// NewAt returns a Value representing a pointer to a value of the +// specified type, using p as that pointer. +func NewAt(typ Type, p unsafe.Pointer) Value { + fl := flag(Ptr) + return Value{typ.common().ptrTo(), p, fl} +} + +// assignTo returns a value v that can be assigned directly to typ. +// It panics if v is not assignable to typ. +// For a conversion to an interface type, target is a suggested scratch space to use. +func (v Value) assignTo(context string, dst *rtype, target unsafe.Pointer) Value { + if v.flag&flagMethod != 0 { + v = makeMethodValue(context, v) + } + + switch { + case directlyAssignable(dst, v.typ): + // Overwrite type so that they match. + // Same memory layout, so no harm done. + v.typ = dst + fl := v.flag & (flagRO | flagAddr | flagIndir) + fl |= flag(dst.Kind()) + return Value{dst, v.ptr, fl} + + case implements(dst, v.typ): + if target == nil { + target = unsafe_New(dst) + } + x := valueInterface(v, false) + if dst.NumMethod() == 0 { + *(*interface{})(target) = x + } else { + ifaceE2I(dst, x, target) + } + return Value{dst, target, flagIndir | flag(Interface)} + } + + // Failed. + panic(context + ": value of type " + v.typ.String() + " is not assignable to type " + dst.String()) +} + +// Convert returns the value v converted to type t. +// If the usual Go conversion rules do not allow conversion +// of the value v to type t, Convert panics. +func (v Value) Convert(t Type) Value { + if v.flag&flagMethod != 0 { + v = makeMethodValue("Convert", v) + } + op := convertOp(t.common(), v.typ) + if op == nil { + panic("reflect.Value.Convert: value of type " + v.typ.String() + " cannot be converted to type " + t.String()) + } + return op(v, t) +} + +// convertOp returns the function to convert a value of type src +// to a value of type dst. If the conversion is illegal, convertOp returns nil. +func convertOp(dst, src *rtype) func(Value, Type) Value { + switch src.Kind() { + case Int, Int8, Int16, Int32, Int64: + switch dst.Kind() { + case Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return cvtInt + case Float32, Float64: + return cvtIntFloat + case String: + return cvtIntString + } + + case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + switch dst.Kind() { + case Int, Int8, Int16, Int32, Int64, Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return cvtUint + case Float32, Float64: + return cvtUintFloat + case String: + return cvtUintString + } + + case Float32, Float64: + switch dst.Kind() { + case Int, Int8, Int16, Int32, Int64: + return cvtFloatInt + case Uint, Uint8, Uint16, Uint32, Uint64, Uintptr: + return cvtFloatUint + case Float32, Float64: + return cvtFloat + } + + case Complex64, Complex128: + switch dst.Kind() { + case Complex64, Complex128: + return cvtComplex + } + + case String: + if dst.Kind() == Slice && dst.Elem().PkgPath() == "" { + switch dst.Elem().Kind() { + case Uint8: + return cvtStringBytes + case Int32: + return cvtStringRunes + } + } + + case Slice: + if dst.Kind() == String && src.Elem().PkgPath() == "" { + switch src.Elem().Kind() { + case Uint8: + return cvtBytesString + case Int32: + return cvtRunesString + } + } + } + + // dst and src have same underlying type. + if haveIdenticalUnderlyingType(dst, src) { + return cvtDirect + } + + // dst and src are unnamed pointer types with same underlying base type. + if dst.Kind() == Ptr && dst.Name() == "" && + src.Kind() == Ptr && src.Name() == "" && + haveIdenticalUnderlyingType(dst.Elem().common(), src.Elem().common()) { + return cvtDirect + } + + if implements(dst, src) { + if src.Kind() == Interface { + return cvtI2I + } + return cvtT2I + } + + return nil +} + +// makeInt returns a Value of type t equal to bits (possibly truncated), +// where t is a signed or unsigned int type. +func makeInt(f flag, bits uint64, t Type) Value { + typ := t.common() + ptr := unsafe_New(typ) + switch typ.size { + case 1: + *(*uint8)(unsafe.Pointer(ptr)) = uint8(bits) + case 2: + *(*uint16)(unsafe.Pointer(ptr)) = uint16(bits) + case 4: + *(*uint32)(unsafe.Pointer(ptr)) = uint32(bits) + case 8: + *(*uint64)(unsafe.Pointer(ptr)) = bits + } + return Value{typ, ptr, f | flagIndir | flag(typ.Kind())} +} + +// makeFloat returns a Value of type t equal to v (possibly truncated to float32), +// where t is a float32 or float64 type. +func makeFloat(f flag, v float64, t Type) Value { + typ := t.common() + ptr := unsafe_New(typ) + switch typ.size { + case 4: + *(*float32)(unsafe.Pointer(ptr)) = float32(v) + case 8: + *(*float64)(unsafe.Pointer(ptr)) = v + } + return Value{typ, ptr, f | flagIndir | flag(typ.Kind())} +} + +// makeComplex returns a Value of type t equal to v (possibly truncated to complex64), +// where t is a complex64 or complex128 type. +func makeComplex(f flag, v complex128, t Type) Value { + typ := t.common() + ptr := unsafe_New(typ) + switch typ.size { + case 8: + *(*complex64)(unsafe.Pointer(ptr)) = complex64(v) + case 16: + *(*complex128)(unsafe.Pointer(ptr)) = v + } + return Value{typ, ptr, f | flagIndir | flag(typ.Kind())} +} + +func makeString(f flag, v string, t Type) Value { + ret := New(t).Elem() + ret.SetString(v) + ret.flag = ret.flag&^flagAddr | f + return ret +} + +func makeBytes(f flag, v []byte, t Type) Value { + ret := New(t).Elem() + ret.SetBytes(v) + ret.flag = ret.flag&^flagAddr | f + return ret +} + +func makeRunes(f flag, v []rune, t Type) Value { + ret := New(t).Elem() + ret.setRunes(v) + ret.flag = ret.flag&^flagAddr | f + return ret +} + +// These conversion functions are returned by convertOp +// for classes of conversions. For example, the first function, cvtInt, +// takes any value v of signed int type and returns the value converted +// to type t, where t is any signed or unsigned int type. + +// convertOp: intXX -> [u]intXX +func cvtInt(v Value, t Type) Value { + return makeInt(v.flag&flagRO, uint64(v.Int()), t) +} + +// convertOp: uintXX -> [u]intXX +func cvtUint(v Value, t Type) Value { + return makeInt(v.flag&flagRO, v.Uint(), t) +} + +// convertOp: floatXX -> intXX +func cvtFloatInt(v Value, t Type) Value { + return makeInt(v.flag&flagRO, uint64(int64(v.Float())), t) +} + +// convertOp: floatXX -> uintXX +func cvtFloatUint(v Value, t Type) Value { + return makeInt(v.flag&flagRO, uint64(v.Float()), t) +} + +// convertOp: intXX -> floatXX +func cvtIntFloat(v Value, t Type) Value { + return makeFloat(v.flag&flagRO, float64(v.Int()), t) +} + +// convertOp: uintXX -> floatXX +func cvtUintFloat(v Value, t Type) Value { + return makeFloat(v.flag&flagRO, float64(v.Uint()), t) +} + +// convertOp: floatXX -> floatXX +func cvtFloat(v Value, t Type) Value { + return makeFloat(v.flag&flagRO, v.Float(), t) +} + +// convertOp: complexXX -> complexXX +func cvtComplex(v Value, t Type) Value { + return makeComplex(v.flag&flagRO, v.Complex(), t) +} + +// convertOp: intXX -> string +func cvtIntString(v Value, t Type) Value { + return makeString(v.flag&flagRO, string(v.Int()), t) +} + +// convertOp: uintXX -> string +func cvtUintString(v Value, t Type) Value { + return makeString(v.flag&flagRO, string(v.Uint()), t) +} + +// convertOp: []byte -> string +func cvtBytesString(v Value, t Type) Value { + return makeString(v.flag&flagRO, string(v.Bytes()), t) +} + +// convertOp: string -> []byte +func cvtStringBytes(v Value, t Type) Value { + return makeBytes(v.flag&flagRO, []byte(v.String()), t) +} + +// convertOp: []rune -> string +func cvtRunesString(v Value, t Type) Value { + return makeString(v.flag&flagRO, string(v.runes()), t) +} + +// convertOp: string -> []rune +func cvtStringRunes(v Value, t Type) Value { + return makeRunes(v.flag&flagRO, []rune(v.String()), t) +} + +// convertOp: direct copy +func cvtDirect(v Value, typ Type) Value { + f := v.flag + t := typ.common() + ptr := v.ptr + if f&flagAddr != 0 { + // indirect, mutable word - make a copy + c := unsafe_New(t) + memmove(c, ptr, t.size) + ptr = c + f &^= flagAddr + } + return Value{t, ptr, v.flag&flagRO | f} // v.flag&flagRO|f == f? +} + +// convertOp: concrete -> interface +func cvtT2I(v Value, typ Type) Value { + target := unsafe_New(typ.common()) + x := valueInterface(v, false) + if typ.NumMethod() == 0 { + *(*interface{})(target) = x + } else { + ifaceE2I(typ.(*rtype), x, target) + } + return Value{typ.common(), target, v.flag&flagRO | flagIndir | flag(Interface)} +} + +// convertOp: interface -> interface +func cvtI2I(v Value, typ Type) Value { + if v.IsNil() { + ret := Zero(typ) + ret.flag |= v.flag & flagRO + return ret + } + return cvtT2I(v.Elem(), typ) +} + +// implemented in ../runtime +func chancap(ch unsafe.Pointer) int +func chanclose(ch unsafe.Pointer) +func chanlen(ch unsafe.Pointer) int + +//go:noescape +func chanrecv(t *rtype, ch unsafe.Pointer, nb bool, val unsafe.Pointer) (selected, received bool) + +//go:noescape +func chansend(t *rtype, ch unsafe.Pointer, val unsafe.Pointer, nb bool) bool + +func makechan(typ *rtype, size uint64) (ch unsafe.Pointer) +func makemap(t *rtype) (m unsafe.Pointer) +func mapaccess(t *rtype, m unsafe.Pointer, key unsafe.Pointer) (val unsafe.Pointer) +func mapassign(t *rtype, m unsafe.Pointer, key, val unsafe.Pointer) +func mapdelete(t *rtype, m unsafe.Pointer, key unsafe.Pointer) +func mapiterinit(t *rtype, m unsafe.Pointer) unsafe.Pointer +func mapiterkey(it unsafe.Pointer) (key unsafe.Pointer) +func mapiternext(it unsafe.Pointer) +func maplen(m unsafe.Pointer) int +func call(fn, arg unsafe.Pointer, n uint32, retoffset uint32) + +func ifaceE2I(t *rtype, src interface{}, dst unsafe.Pointer) + +//go:noescape +func memmove(adst, asrc unsafe.Pointer, n uintptr) + +// Dummy annotation marking that the value x escapes, +// for use in cases where the reflect code is so clever that +// the compiler cannot follow. +func escapes(x interface{}) { + if dummy.b { + dummy.x = x + } +} + +var dummy struct { + b bool + x interface{} +} |