[dev.fuzz] all: merge master into dev.fuzz

Change-Id: I5d8c8329ccc9d747bd81ade6b1cb7cb8ae2e94b2

5 files changed, 307 insertions, 42 deletions

diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go
index 5a12699472..b01158635f 100644
--- a/src/reflect/all_test.go
+++ b/src/reflect/all_test.go
@@ -2405,8 +2405,14 @@ func TestVariadicMethodValue(t *testing.T) {
 	points := []Point{{20, 21}, {22, 23}, {24, 25}}
 	want := int64(p.TotalDist(points[0], points[1], points[2]))
 
+	// Variadic method of type.
+	tfunc := TypeOf((func(Point, ...Point) int)(nil))
+	if tt := TypeOf(p).Method(4).Type; tt != tfunc {
+		t.Errorf("Variadic Method Type from TypeOf is %s; want %s", tt, tfunc)
+	}
+
 	// Curried method of value.
-	tfunc := TypeOf((func(...Point) int)(nil))
+	tfunc = TypeOf((func(...Point) int)(nil))
 	v := ValueOf(p).Method(4)
 	if tt := v.Type(); tt != tfunc {
 		t.Errorf("Variadic Method Type is %s; want %s", tt, tfunc)
@@ -4001,9 +4007,12 @@ var convertTests = []struct {
 	{V(int16(-3)), V(string("\uFFFD"))},
 	{V(int32(-4)), V(string("\uFFFD"))},
 	{V(int64(-5)), V(string("\uFFFD"))},
+	{V(int64(-1 << 32)), V(string("\uFFFD"))},
+	{V(int64(1 << 32)), V(string("\uFFFD"))},
 	{V(uint(0x110001)), V(string("\uFFFD"))},
 	{V(uint32(0x110002)), V(string("\uFFFD"))},
 	{V(uint64(0x110003)), V(string("\uFFFD"))},
+	{V(uint64(1 << 32)), V(string("\uFFFD"))},
 	{V(uintptr(0x110004)), V(string("\uFFFD"))},
 
 	// named string
@@ -4259,24 +4268,6 @@ var gFloat32 float32
 
 func TestConvertNaNs(t *testing.T) {
 	const snan uint32 = 0x7f800001
-
-	// Test to see if a store followed by a load of a signaling NaN
-	// maintains the signaling bit. The only platform known to fail
-	// this test is 386,GO386=387. The real test below will always fail
-	// if the platform can't even store+load a float without mucking
-	// with the bits.
-	gFloat32 = math.Float32frombits(snan)
-	runtime.Gosched() // make sure we don't optimize the store/load away
-	r := math.Float32bits(gFloat32)
-	if r != snan {
-		// This should only happen on 386,GO386=387. We have no way to
-		// test for 387, so we just make sure we're at least on 386.
-		if runtime.GOARCH != "386" {
-			t.Errorf("store/load of sNaN not faithful")
-		}
-		t.Skip("skipping test, float store+load not faithful")
-	}
-
 	type myFloat32 float32
 	x := V(myFloat32(math.Float32frombits(snan)))
 	y := x.Convert(TypeOf(float32(0)))
@@ -6006,6 +5997,14 @@ func TestReflectMethodTraceback(t *testing.T) {
 	}
 }
 
+func TestSmallZero(t *testing.T) {
+	type T [10]byte
+	typ := TypeOf(T{})
+	if allocs := testing.AllocsPerRun(100, func() { Zero(typ) }); allocs > 0 {
+		t.Errorf("Creating small zero values caused %f allocs, want 0", allocs)
+	}
+}
+
 func TestBigZero(t *testing.T) {
 	const size = 1 << 10
 	var v [size]byte
@@ -6017,6 +6016,27 @@ func TestBigZero(t *testing.T) {
 	}
 }
 
+func TestZeroSet(t *testing.T) {
+	type T [16]byte
+	type S struct {
+		a uint64
+		T T
+		b uint64
+	}
+	v := S{
+		a: 0xaaaaaaaaaaaaaaaa,
+		T: T{9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9},
+		b: 0xbbbbbbbbbbbbbbbb,
+	}
+	ValueOf(&v).Elem().Field(1).Set(Zero(TypeOf(T{})))
+	if v != (S{
+		a: 0xaaaaaaaaaaaaaaaa,
+		b: 0xbbbbbbbbbbbbbbbb,
+	}) {
+		t.Fatalf("Setting a field to a Zero value didn't work")
+	}
+}
+
 func TestFieldByIndexNil(t *testing.T) {
 	type P struct {
 		F int
@@ -7148,6 +7168,176 @@ func TestMapIterDelete1(t *testing.T) {
 	}
 }
 
+func TestStructTagLookup(t *testing.T) {
+	var tests = []struct {
+		tag           StructTag
+		key           string
+		expectedValue string
+		expectedOK    bool
+	}{
+		{
+			tag:           `json:"json_value_1"`,
+			key:           "json",
+			expectedValue: "json_value_1",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json:"json_value_2" xml:"xml_value_2"`,
+			key:           "json",
+			expectedValue: "json_value_2",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json:"json_value_3" xml:"xml_value_3"`,
+			key:           "xml",
+			expectedValue: "xml_value_3",
+			expectedOK:    true,
+		},
+		{
+			tag:           `bson json:"shared_value_4"`,
+			key:           "json",
+			expectedValue: "shared_value_4",
+			expectedOK:    true,
+		},
+		{
+			tag:           `bson json:"shared_value_5"`,
+			key:           "bson",
+			expectedValue: "shared_value_5",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json bson xml form:"field_1,omitempty" other:"value_1"`,
+			key:           "xml",
+			expectedValue: "field_1,omitempty",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json bson xml form:"field_2,omitempty" other:"value_2"`,
+			key:           "form",
+			expectedValue: "field_2,omitempty",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json bson xml form:"field_3,omitempty" other:"value_3"`,
+			key:           "other",
+			expectedValue: "value_3",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json    bson    xml    form:"field_4" other:"value_4"`,
+			key:           "json",
+			expectedValue: "field_4",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json    bson    xml    form:"field_5" other:"value_5"`,
+			key:           "non_existing",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           `json "json_6"`,
+			key:           "json",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           `json:"json_7" bson "bson_7"`,
+			key:           "json",
+			expectedValue: "json_7",
+			expectedOK:    true,
+		},
+		{
+			tag:           `json:"json_8" xml "xml_8"`,
+			key:           "xml",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           `json    bson    xml    form "form_9" other:"value_9"`,
+			key:           "bson",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           `json bson xml form "form_10" other:"value_10"`,
+			key:           "other",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           `json bson xml form:"form_11" other "value_11"`,
+			key:           "json",
+			expectedValue: "form_11",
+			expectedOK:    true,
+		},
+		{
+			tag:           `tag1`,
+			key:           "tag1",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           `tag2 :"hello_2"`,
+			key:           "tag2",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           `tag3: "hello_3"`,
+			key:           "tag3",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           "json\x7fbson: \"hello_4\"",
+			key:           "json",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           "json\x7fbson: \"hello_5\"",
+			key:           "bson",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           "json bson:\x7f\"hello_6\"",
+			key:           "json",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           "json bson:\x7f\"hello_7\"",
+			key:           "bson",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           "json\x09bson:\"hello_8\"",
+			key:           "json",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+		{
+			tag:           "a\x7fb json:\"val\"",
+			key:           "json",
+			expectedValue: "",
+			expectedOK:    false,
+		},
+	}
+
+	for _, test := range tests {
+		v, ok := test.tag.Lookup(test.key)
+		if v != test.expectedValue {
+			t.Errorf("struct tag lookup failed, got %s, want %s", v, test.expectedValue)
+		}
+		if ok != test.expectedOK {
+			t.Errorf("struct tag lookup failed, got %t, want %t", ok, test.expectedOK)
+		}
+	}
+}
+
 // iterateToString returns the set of elements
 // returned by an iterator in readable form.
 func iterateToString(it *MapIter) string {
diff --git a/src/reflect/asm_amd64.s b/src/reflect/asm_amd64.s
index fb28ab87f1..5c8e56558c 100644
--- a/src/reflect/asm_amd64.s
+++ b/src/reflect/asm_amd64.s
@@ -9,7 +9,9 @@
 // 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),$32
+// makeFuncStub must be ABIInternal because it is placed directly
+// in function values.
+TEXT ·makeFuncStub<ABIInternal>(SB),(NOSPLIT|WRAPPER),$32
 	NO_LOCAL_POINTERS
 	MOVQ	DX, 0(SP)
 	LEAQ	argframe+0(FP), CX
@@ -17,14 +19,16 @@ TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$32
 	MOVB	$0, 24(SP)
 	LEAQ	24(SP), AX
 	MOVQ	AX, 16(SP)
-	CALL	·callReflect(SB)
+	CALL	·callReflect<ABIInternal>(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),$32
+// methodValueCall must be ABIInternal because it is placed directly
+// in function values.
+TEXT ·methodValueCall<ABIInternal>(SB),(NOSPLIT|WRAPPER),$32
 	NO_LOCAL_POINTERS
 	MOVQ	DX, 0(SP)
 	LEAQ	argframe+0(FP), CX
@@ -32,5 +36,5 @@ TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$32
 	MOVB	$0, 24(SP)
 	LEAQ	24(SP), AX
 	MOVQ	AX, 16(SP)
-	CALL	·callMethod(SB)
+	CALL	·callMethod<ABIInternal>(SB)
 	RET
diff --git a/src/reflect/deepequal.go b/src/reflect/deepequal.go
index be66464129..d951d8d999 100644
--- a/src/reflect/deepequal.go
+++ b/src/reflect/deepequal.go
@@ -35,7 +35,17 @@ func deepValueEqual(v1, v2 Value, visited map[visit]bool) bool {
 	// and it's safe and valid to get Value's internal pointer.
 	hard := func(v1, v2 Value) bool {
 		switch v1.Kind() {
-		case Map, Slice, Ptr, Interface:
+		case Ptr:
+			if v1.typ.ptrdata == 0 {
+				// go:notinheap pointers can't be cyclic.
+				// At least, all of our current uses of go:notinheap have
+				// that property. The runtime ones aren't cyclic (and we don't use
+				// DeepEqual on them anyway), and the cgo-generated ones are
+				// all empty structs.
+				return false
+			}
+			fallthrough
+		case Map, Slice, Interface:
 			// Nil pointers cannot be cyclic. Avoid putting them in the visited map.
 			return !v1.IsNil() && !v2.IsNil()
 		}
diff --git a/src/reflect/type.go b/src/reflect/type.go
index 44c96fea82..1f1e70d485 100644
--- a/src/reflect/type.go
+++ b/src/reflect/type.go
@@ -50,13 +50,13 @@ type Type interface {
 	// 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.
+	// fields describe a function whose first argument is the receiver,
+	// and only exported methods are accessible.
 	//
 	// For an interface type, the returned Method's Type field gives the
 	// method signature, without a receiver, and the Func field is nil.
 	//
-	// Only exported methods are accessible and they are sorted in
-	// lexicographic order.
+	// Methods are sorted in lexicographic order.
 	Method(int) Method
 
 	// MethodByName returns the method with that name in the type's
@@ -69,7 +69,9 @@ type Type interface {
 	// method signature, without a receiver, and the Func field is nil.
 	MethodByName(string) (Method, bool)
 
-	// NumMethod returns the number of exported methods in the type's method set.
+	// NumMethod returns the number of methods accessible using Method.
+	//
+	// Note that NumMethod counts unexported methods only for interface types.
 	NumMethod() int
 
 	// Name returns the type's name within its package for a defined type.
@@ -1102,12 +1104,16 @@ type StructField struct {
 
 // 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.
+// By convention, tag strings are a mapping of keys to values.
+// The format is key:"value". 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.
+// Multiple key-value mappings are separated by zero or more spaces, as in
+//   key1:"value1" key2:"value2"
+// Multiple keys may map to a single shared value by separating the keys
+// with spaces, as in
+//   key1 key2:"value"
 type StructTag string
 
 // Get returns the value associated with key in the tag string.
@@ -1130,6 +1136,9 @@ func (tag StructTag) Lookup(key string) (value string, ok bool) {
 	// When modifying this code, also update the validateStructTag code
 	// in cmd/vet/structtag.go.
 
+	// keyFound indicates that such key on the left side has already been found.
+	var keyFound bool
+
 	for tag != "" {
 		// Skip leading space.
 		i := 0
@@ -1149,11 +1158,29 @@ func (tag StructTag) Lookup(key string) (value string, ok bool) {
 		for i < len(tag) && tag[i] > ' ' && tag[i] != ':' && tag[i] != '"' && tag[i] != 0x7f {
 			i++
 		}
-		if i == 0 || i+1 >= len(tag) || tag[i] != ':' || tag[i+1] != '"' {
+		if i == 0 || i+1 >= len(tag) || tag[i] < ' ' || tag[i] == 0x7f {
 			break
 		}
 		name := string(tag[:i])
-		tag = tag[i+1:]
+		tag = tag[i:]
+
+		// If we found a space char here - assume that we have a tag with
+		// multiple keys.
+		if tag[0] == ' ' {
+			if name == key {
+				keyFound = true
+			}
+			continue
+		}
+
+		// Spaces were filtered above so we assume that here we have
+		// only valid tag value started with `:"`.
+		if tag[0] != ':' || tag[1] != '"' {
+			break
+		}
+
+		// Remove the colon leaving tag at the start of the quoted string.
+		tag = tag[1:]
 
 		// Scan quoted string to find value.
 		i = 1
@@ -1169,7 +1196,7 @@ func (tag StructTag) Lookup(key string) (value string, ok bool) {
 		qvalue := string(tag[:i+1])
 		tag = tag[i+1:]
 
-		if key == name {
+		if key == name || keyFound {
 			value, err := strconv.Unquote(qvalue)
 			if err != nil {
 				break
diff --git a/src/reflect/value.go b/src/reflect/value.go
index c6f24a5609..1f185b52e4 100644
--- a/src/reflect/value.go
+++ b/src/reflect/value.go
@@ -90,6 +90,7 @@ func (f flag) ro() flag {
 
 // pointer returns the underlying pointer represented by v.
 // v.Kind() must be Ptr, Map, Chan, Func, or UnsafePointer
+// if v.Kind() == Ptr, the base type must not be go:notinheap.
 func (v Value) pointer() unsafe.Pointer {
 	if v.typ.size != ptrSize || !v.typ.pointers() {
 		panic("can't call pointer on a non-pointer Value")
@@ -1452,7 +1453,16 @@ func (v Value) Pointer() uintptr {
 	// TODO: deprecate
 	k := v.kind()
 	switch k {
-	case Chan, Map, Ptr, UnsafePointer:
+	case Ptr:
+		if v.typ.ptrdata == 0 {
+			// Handle pointers to go:notinheap types directly,
+			// so we never materialize such pointers as an
+			// unsafe.Pointer. (Such pointers are always indirect.)
+			// See issue 42076.
+			return *(*uintptr)(v.ptr)
+		}
+		fallthrough
+	case Chan, Map, UnsafePointer:
 		return uintptr(v.pointer())
 	case Func:
 		if v.flag&flagMethod != 0 {
@@ -1553,7 +1563,11 @@ func (v Value) Set(x Value) {
 	}
 	x = x.assignTo("reflect.Set", v.typ, target)
 	if x.flag&flagIndir != 0 {
-		typedmemmove(v.typ, v.ptr, x.ptr)
+		if x.ptr == unsafe.Pointer(&zeroVal[0]) {
+			typedmemclr(v.typ, v.ptr)
+		} else {
+			typedmemmove(v.typ, v.ptr, x.ptr)
+		}
 	} else {
 		*(*unsafe.Pointer)(v.ptr) = x.ptr
 	}
@@ -2360,11 +2374,23 @@ func Zero(typ Type) Value {
 	t := typ.(*rtype)
 	fl := flag(t.Kind())
 	if ifaceIndir(t) {
-		return Value{t, unsafe_New(t), fl | flagIndir}
+		var p unsafe.Pointer
+		if t.size <= maxZero {
+			p = unsafe.Pointer(&zeroVal[0])
+		} else {
+			p = unsafe_New(t)
+		}
+		return Value{t, p, fl | flagIndir}
 	}
 	return Value{t, nil, fl}
 }
 
+// must match declarations in runtime/map.go.
+const maxZero = 1024
+
+//go:linkname zeroVal runtime.zeroVal
+var zeroVal [maxZero]byte
+
 // 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 {
@@ -2655,12 +2681,20 @@ func cvtComplex(v Value, t Type) Value {
 
 // convertOp: intXX -> string
 func cvtIntString(v Value, t Type) Value {
-	return makeString(v.flag.ro(), string(rune(v.Int())), t)
+	s := "\uFFFD"
+	if x := v.Int(); int64(rune(x)) == x {
+		s = string(rune(x))
+	}
+	return makeString(v.flag.ro(), s, t)
 }
 
 // convertOp: uintXX -> string
 func cvtUintString(v Value, t Type) Value {
-	return makeString(v.flag.ro(), string(rune(v.Uint())), t)
+	s := "\uFFFD"
+	if x := v.Uint(); uint64(rune(x)) == x {
+		s = string(rune(x))
+	}
+	return makeString(v.flag.ro(), s, t)
 }
 
 // convertOp: []byte -> string