interp: support calling goto from sub-scope

As opposed to other symbols, goto labels must be searched in included
scopes, not upper ones. Implement scope.lookdown to perform this,
to allow calls to goto to be embedded in included scopes where label
is defined.

Fixes #953.

_test/composite14.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+type T struct {
+	b []byte
+}
+
+func main() {
+	t := T{nil}
+	fmt.Println(t)
+}
+
+// Output:
+// {[]}

_test/convert0.go

@@ -0,0 +1,21 @@
+package main
+
+type T struct {
+	v int
+}
+
+type comparator func(T, T) bool
+
+func sort(items []T, comp comparator) {
+	println("in sort")
+}
+
+func compT(t0, t1 T) bool { return t0.v < t1.v }
+
+func main() {
+	a := []T{}
+	sort(a, comparator(compT))
+}
+
+// Output:
+// in sort

_test/convert1.go

@@ -0,0 +1,17 @@
+package main
+
+import "strconv"
+
+type atoidef func(s string) (int, error)
+
+func main() {
+	stdatoi := atoidef(strconv.Atoi)
+	n, err := stdatoi("7")
+	if err != nil {
+		panic(err)
+	}
+	println(n)
+}
+
+// Output:
+// 7

_test/convert2.go

@@ -0,0 +1,19 @@
+package main
+
+import "bufio"
+
+func fakeSplitFunc(data []byte, atEOF bool) (advance int, token []byte, err error) {
+	return 7, nil, nil
+}
+
+func main() {
+	splitfunc := bufio.SplitFunc(fakeSplitFunc)
+	n, _, err := splitfunc(nil, true)
+	if err != nil {
+		panic(err)
+	}
+	println(n)
+}
+
+// Output:
+// 7

_test/for15.go

@@ -0,0 +1,16 @@
+package main
+
+func f() int { println("in f"); return 1 }
+
+func main() {
+	for i := f(); ; {
+		println("in loop")
+		if i > 0 {
+			break
+		}
+	}
+}
+
+// Output:
+// in f
+// in loop

_test/for16.go

@@ -0,0 +1,16 @@
+package main
+
+func main() {
+	max := 1
+	for ; ; max-- {
+		if max == 0 {
+			break
+		}
+		println("in for")
+	}
+	println("bye")
+}
+
+// Output:
+// in for
+// bye

_test/fun26.go

@@ -0,0 +1,17 @@
+package main
+
+type F func() (int, error)
+
+func f1() (int, error) { return 3, nil }
+
+func f2(a string, f F) {
+	c, _ := f()
+	println(a, c)
+}
+
+func main() {
+	f2("hello", F(f1))
+}
+
+// Output:
+// hello 3

_test/goto1.go

@@ -0,0 +1,12 @@
+package main
+
+func main() {
+	if true {
+		goto here
+	}
+here:
+	println("ok")
+}
+
+// Output:
+// ok

_test/nil3.go

@@ -0,0 +1,28 @@
+package main
+
+type I interface {
+	Hello()
+}
+
+type T struct {
+	h I
+}
+
+func (t *T) Hello() { println("Hello") }
+
+func main() {
+	t := &T{}
+	println(t.h != nil)
+	println(t.h == nil)
+	t.h = t
+	println(t.h != nil)
+	println(t.h == nil)
+	t.h.Hello()
+}
+
+// Output:
+// false
+// true
+// true
+// false
+// Hello

_test/time14.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+var t time.Time
+
+func f() time.Time {
+	time := t
+	return time
+}
+
+func main() {
+	fmt.Println(f())
+}
+
+// Output:
+// 0001-01-01 00:00:00 +0000 UTC

example/pkg/_pkg13/src/guthib.com/foo/bar/main.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"fmt"
+
+	"guthib.com/bat/baz"
+)
+
+func main() {
+	t := baz.NewT()
+
+	fmt.Printf("%s", t.A3)
+}

example/pkg/_pkg13/src/guthib.com/foo/bar/vendor/guthib.com/bat/baz/baz.go

@@ -0,0 +1,22 @@
+package baz
+
+func NewT() *T {
+	return &T{
+		A1: make([]U, 0),
+		A3: "foobar",
+	}
+}
+
+type T struct {
+	A1 []U
+	A3 string
+}
+
+type U struct {
+	B1 V
+	B2 V
+}
+
+type V struct {
+	C1 string
+}

example/pkg/pkg_test.go

@@ -93,6 +93,12 @@ func TestPackages(t *testing.T) {
 			expected: "Yo hello",
 			evalFile: "./_pkg12/src/guthib.com/foo/main.go",
 		},
+		{
+			desc:     "eval main with vendor",
+			goPath:   "./_pkg13/",
+			expected: "foobar",
+			evalFile: "./_pkg13/src/guthib.com/foo/bar/main.go",
+		},
 	}
 
 	for _, test := range testCases {

extract/extract.go

@@ -436,10 +436,12 @@ func GetMinor(part string) string {
 	return minor
 }
 
+const defaultMinorVersion = 15
+
 func genBuildTags() (string, error) {
 	version := runtime.Version()
-	if version == "devel" {
-		return "", nil
+	if strings.HasPrefix(version, "devel") {
+		return "", fmt.Errorf("extracting only supported with stable releases of Go, not %v", version)
 	}
 	parts := strings.Split(version, ".")
 
@@ -452,6 +454,11 @@ func genBuildTags() (string, error) {
 		return "", fmt.Errorf("failed to parse version: %v", err)
 	}
 
+	// Only append an upper bound if we are not on the latest go
+	if minor >= defaultMinorVersion {
+		return currentGoVersion, nil
+	}
+
 	nextGoVersion := parts[0] + "." + strconv.Itoa(minor+1)
 
 	return currentGoVersion + ",!" + nextGoVersion, nil

internal/cmd/extract/extract.go

@@ -84,11 +84,12 @@ func main() {
 			oFile = strings.ReplaceAll(importPath, "/", "_") + ".go"
 		}
 
-		prefix := runtime.Version()
-		if runtime.Version() != "devel" {
-			parts := strings.Split(runtime.Version(), ".")
-			prefix = parts[0] + "_" + extract.GetMinor(parts[1])
+		version := runtime.Version()
+		if strings.HasPrefix(version, "devel") {
+			log.Fatalf("extracting only supported with stable releases of Go, not %v", version)
 		}
+		parts := strings.Split(version, ".")
+		prefix := parts[0] + "_" + extract.GetMinor(parts[1])
 
 		f, err := os.Create(prefix + "_" + oFile)
 		if err != nil {

interp/ast.go

@@ -51,12 +51,14 @@ const (
 	fieldList
 	fileStmt
 	forStmt0     // for {}
-	forStmt1     // for cond {}
-	forStmt2     // for init; cond; {}
-	forStmt3     // for ; cond; post {}
-	forStmt3a    // for init; ; post {}
-	forStmt4     // for init; cond; post {}
-	forRangeStmt // for range
+	forStmt1     // for init; ; {}
+	forStmt2     // for cond {}
+	forStmt3     // for init; cond; {}
+	forStmt4     // for ; ; post {}
+	forStmt5     // for ; cond; post {}
+	forStmt6     // for init; ; post {}
+	forStmt7     // for init; cond; post {}
+	forRangeStmt // for range {}
 	funcDecl
 	funcLit
 	funcType
@@ -134,8 +136,10 @@ var kinds = [...]string{
 	forStmt1:          "forStmt1",
 	forStmt2:          "forStmt2",
 	forStmt3:          "forStmt3",
-	forStmt3a:         "forStmt3a",
 	forStmt4:          "forStmt4",
+	forStmt5:          "forStmt5",
+	forStmt6:          "forStmt6",
+	forStmt7:          "forStmt7",
 	forRangeStmt:      "forRangeStmt",
 	funcDecl:          "funcDecl",
 	funcType:          "funcType",
@@ -654,23 +658,23 @@ func (interp *Interpreter) ast(src, name string, inc bool) (string, *node, error
 		case *ast.ForStmt:
 			// Disambiguate variants of FOR statements with a node kind per variant
 			var kind nkind
-			if a.Cond == nil {
-				if a.Init != nil && a.Post != nil {
-					kind = forStmt3a
-				} else {
-					kind = forStmt0
-				}
-			} else {
-				switch {
-				case a.Init == nil && a.Post == nil:
-					kind = forStmt1
-				case a.Init != nil && a.Post == nil:
-					kind = forStmt2
-				case a.Init == nil && a.Post != nil:
-					kind = forStmt3
-				default:
-					kind = forStmt4
-				}
+			switch {
+			case a.Cond == nil && a.Init == nil && a.Post == nil:
+				kind = forStmt0
+			case a.Cond == nil && a.Init != nil && a.Post == nil:
+				kind = forStmt1
+			case a.Cond != nil && a.Init == nil && a.Post == nil:
+				kind = forStmt2
+			case a.Cond != nil && a.Init != nil && a.Post == nil:
+				kind = forStmt3
+			case a.Cond == nil && a.Init == nil && a.Post != nil:
+				kind = forStmt4
+			case a.Cond != nil && a.Init == nil && a.Post != nil:
+				kind = forStmt5
+			case a.Cond == nil && a.Init != nil && a.Post != nil:
+				kind = forStmt6
+			case a.Cond != nil && a.Init != nil && a.Post != nil:
+				kind = forStmt7
 			}
 			st.push(addChild(&root, anc, pos, kind, aNop), nod)
 

interp/cfg.go

@@ -66,6 +66,41 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			return false
 		}
 		switch n.kind {
+		case binaryExpr, unaryExpr, parenExpr:
+			if isBoolAction(n) {
+				break
+			}
+			// Gather assigned type if set, to give context for type propagation at post-order.
+			switch n.anc.kind {
+			case assignStmt, defineStmt:
+				a := n.anc
+				i := childPos(n) - a.nright
+				if len(a.child) > a.nright+a.nleft {
+					i--
+				}
+				dest := a.child[i]
+				if dest.typ != nil && !isInterface(dest.typ) {
+					// Interface type are not propagated, and will be resolved at post-order.
+					n.typ = dest.typ
+				}
+			case binaryExpr, unaryExpr, parenExpr:
+				n.typ = n.anc.typ
+			}
+
+		case defineStmt:
+			// Determine type of variables initialized at declaration, so it can be propagated.
+			if n.nleft+n.nright == len(n.child) {
+				// No type was specified on the left hand side, it will resolved at post-order.
+				break
+			}
+			n.typ, err = nodeType(interp, sc, n.child[n.nleft])
+			if err != nil {
+				break
+			}
+			for i := 0; i < n.nleft; i++ {
+				n.child[i].typ = n.typ
+			}
+
 		case blockStmt:
 			if n.anc != nil && n.anc.kind == rangeStmt {
 				// For range block: ensure that array or map type is propagated to iterators
@@ -159,7 +194,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 
 		case breakStmt, continueStmt, gotoStmt:
 			if len(n.child) > 0 {
-				// Handle labeled statements
+				// Handle labeled statements.
 				label := n.child[0].ident
 				if sym, _, ok := sc.lookup(label); ok {
 					if sym.kind != labelSym {
@@ -176,25 +211,23 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 
 		case labeledStmt:
 			label := n.child[0].ident
-			if sym, _, ok := sc.lookup(label); ok {
-				if sym.kind != labelSym {
-					err = n.child[0].cfgErrorf("label %s not defined", label)
-					break
-				}
+			// TODO(marc): labels must be stored outside of symbols to avoid collisions
+			// Used labels are searched in current and sub scopes, not upper ones.
+			if sym, ok := sc.lookdown(label); ok {
 				sym.node = n
 				n.sym = sym
 			} else {
 				n.sym = &symbol{kind: labelSym, node: n, index: -1}
-				sc.sym[label] = n.sym
 			}
+			sc.sym[label] = n.sym
 
 		case caseClause:
 			sc = sc.pushBloc()
 			if sn := n.anc.anc; sn.kind == typeSwitch && sn.child[1].action == aAssign {
-				// Type switch clause with a var defined in switch guard
+				// Type switch clause with a var defined in switch guard.
 				var typ *itype
 				if len(n.child) == 2 {
-					// 1 type in clause: define the var with this type in the case clause scope
+					// 1 type in clause: define the var with this type in the case clause scope.
 					switch {
 					case n.child[0].ident == nilIdent:
 						typ = sc.getType("interface{}")
@@ -204,7 +237,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 						typ, err = nodeType(interp, sc, n.child[0])
 					}
 				} else {
-					// define the var with the type in the switch guard expression
+					// Define the var with the type in the switch guard expression.
 					typ = sn.child[1].child[1].child[0].typ
 				}
 				if err != nil {
@@ -285,11 +318,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 				}
 			}
 
-		case forStmt0, forRangeStmt:
-			sc = sc.pushBloc()
-			sc.loop, sc.loopRestart = n, n.child[0]
-
-		case forStmt1, forStmt2, forStmt3, forStmt3a, forStmt4:
+		case forStmt0, forStmt1, forStmt2, forStmt3, forStmt4, forStmt5, forStmt6, forStmt7, forRangeStmt:
 			sc = sc.pushBloc()
 			sc.loop, sc.loopRestart = n, n.lastChild()
 
@@ -447,7 +476,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			var atyp *itype
 			if n.nleft+n.nright < len(n.child) {
 				if atyp, err = nodeType(interp, sc, n.child[n.nleft]); err != nil {
-					return
+					break
 				}
 			}
 
@@ -644,7 +673,12 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			}
 
 			switch n.action {
-			case aRem, aShl, aShr:
+			case aRem:
+				n.typ = c0.typ
+			case aShl, aShr:
+				if c0.typ.untyped {
+					break
+				}
 				n.typ = c0.typ
 			case aEqual, aNotEqual:
 				n.typ = sc.getType("bool")
@@ -860,7 +894,12 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 					n.gen = nop
 					n.findex = -1
 					n.typ = c0.typ
-					n.rval = c1.rval.Convert(c0.typ.rtype)
+					if c, ok := c1.rval.Interface().(constant.Value); ok {
+						i, _ := constant.Int64Val(constant.ToInt(c))
+						n.rval = reflect.ValueOf(i).Convert(c0.typ.rtype)
+					} else {
+						n.rval = c1.rval.Convert(c0.typ.rtype)
+					}
 				default:
 					n.gen = convert
 					n.typ = c0.typ
@@ -1005,7 +1044,14 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			body.tnext = n.start
 			sc = sc.pop()
 
-		case forStmt1: // for cond {}
+		case forStmt1: // for init; ; {}
+			init, body := n.child[0], n.child[1]
+			n.start = init.start
+			init.tnext = body.start
+			body.tnext = n.start
+			sc = sc.pop()
+
+		case forStmt2: // for cond {}
 			cond, body := n.child[0], n.child[1]
 			if !isBool(cond.typ) {
 				err = cond.cfgErrorf("non-bool used as for condition")
@@ -1024,7 +1070,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			setFNext(cond, n)
 			sc = sc.pop()
 
-		case forStmt2: // for init; cond; {}
+		case forStmt3: // for init; cond; {}
 			init, cond, body := n.child[0], n.child[1], n.child[2]
 			if !isBool(cond.typ) {
 				err = cond.cfgErrorf("non-bool used as for condition")
@@ -1046,7 +1092,14 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			setFNext(cond, n)
 			sc = sc.pop()
 
-		case forStmt3: // for ; cond; post {}
+		case forStmt4: // for ; ; post {}
+			post, body := n.child[0], n.child[1]
+			n.start = body.start
+			post.tnext = body.start
+			body.tnext = post.start
+			sc = sc.pop()
+
+		case forStmt5: // for ; cond; post {}
 			cond, post, body := n.child[0], n.child[1], n.child[2]
 			if !isBool(cond.typ) {
 				err = cond.cfgErrorf("non-bool used as for condition")
@@ -1066,7 +1119,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			body.tnext = post.start
 			sc = sc.pop()
 
-		case forStmt3a: // for init; ; post {}
+		case forStmt6: // for init; ; post {}
 			init, post, body := n.child[0], n.child[1], n.child[2]
 			n.start = init.start
 			init.tnext = body.start
@@ -1074,7 +1127,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			post.tnext = body.start
 			sc = sc.pop()
 
-		case forStmt4: // for init; cond; post {}
+		case forStmt7: // for init; cond; post {}
 			init, cond, post, body := n.child[0], n.child[1], n.child[2], n.child[3]
 			if !isBool(cond.typ) {
 				err = cond.cfgErrorf("non-bool used as for condition")
@@ -1326,7 +1379,7 @@ func (interp *Interpreter) cfg(root *node, importPath string) ([]*node, error) {
 			n.val = sc.def
 			for i, c := range n.child {
 				var typ *itype
-				typ, err = nodeType(interp, sc, returnSig.child[1].fieldType(i))
+				typ, err = nodeType(interp, sc.upperLevel(), returnSig.child[1].fieldType(i))
 				if err != nil {
 					return
 				}
@@ -2278,7 +2331,7 @@ func isCall(n *node) bool {
 }
 
 func isBinCall(n *node) bool {
-	return n.kind == callExpr && n.child[0].typ.cat == valueT && n.child[0].typ.rtype.Kind() == reflect.Func
+	return isCall(n) && n.child[0].typ.cat == valueT && n.child[0].typ.rtype.Kind() == reflect.Func
 }
 
 func mustReturnValue(n *node) bool {
@@ -2294,7 +2347,7 @@ func mustReturnValue(n *node) bool {
 }
 
 func isRegularCall(n *node) bool {
-	return n.kind == callExpr && n.child[0].typ.cat == funcT
+	return isCall(n) && n.child[0].typ.cat == funcT
 }
 
 func variadicPos(n *node) int {
@@ -2467,3 +2520,12 @@ func isArithmeticAction(n *node) bool {
 		return false
 	}
 }
+
+func isBoolAction(n *node) bool {
+	switch n.action {
+	case aEqual, aGreater, aGreaterEqual, aLand, aLor, aLower, aLowerEqual, aNot, aNotEqual:
+		return true
+	default:
+		return false
+	}
+}

interp/gta.go

@@ -145,7 +145,7 @@ func (interp *Interpreter) gta(root *node, rpath, importPath string) ([]*node, e
 					elementType := sc.getType(typeName)
 					if elementType == nil {
 						// Add type if necessary, so method can be registered
-						sc.sym[typeName] = &symbol{kind: typeSym, typ: &itype{name: typeName, path: rpath, incomplete: true, node: rtn.child[0], scope: sc}}
+						sc.sym[typeName] = &symbol{kind: typeSym, typ: &itype{name: typeName, path: importPath, incomplete: true, node: rtn.child[0], scope: sc}}
 						elementType = sc.sym[typeName].typ
 					}
 					rcvrtype = &itype{cat: ptrT, val: elementType, incomplete: elementType.incomplete, node: rtn, scope: sc}
@@ -154,7 +154,7 @@ func (interp *Interpreter) gta(root *node, rpath, importPath string) ([]*node, e
 					rcvrtype = sc.getType(typeName)
 					if rcvrtype == nil {
 						// Add type if necessary, so method can be registered
-						sc.sym[typeName] = &symbol{kind: typeSym, typ: &itype{name: typeName, path: rpath, incomplete: true, node: rtn, scope: sc}}
+						sc.sym[typeName] = &symbol{kind: typeSym, typ: &itype{name: typeName, path: importPath, incomplete: true, node: rtn, scope: sc}}
 						rcvrtype = sc.sym[typeName].typ
 					}
 				}
@@ -254,12 +254,12 @@ func (interp *Interpreter) gta(root *node, rpath, importPath string) ([]*node, e
 			}
 
 			if n.child[1].kind == identExpr {
-				n.typ = &itype{cat: aliasT, val: typ, name: typeName, path: rpath, field: typ.field, incomplete: typ.incomplete, scope: sc, node: n.child[0]}
+				n.typ = &itype{cat: aliasT, val: typ, name: typeName, path: importPath, field: typ.field, incomplete: typ.incomplete, scope: sc, node: n.child[0]}
 				copy(n.typ.method, typ.method)
 			} else {
 				n.typ = typ
 				n.typ.name = typeName
-				n.typ.path = rpath
+				n.typ.path = importPath
 			}
 
 			asImportName := filepath.Join(typeName, baseName)

interp/interp_eval_test.go

@@ -71,6 +71,27 @@ func TestEvalArithmetic(t *testing.T) {
 	})
 }
 
+func TestEvalShift(t *testing.T) {
+	i := interp.New(interp.Options{})
+	runTests(t, i, []testCase{
+		{src: "a, b, m := uint32(1), uint32(2), uint32(0); m = a + (1 << b)", res: "5"},
+		{src: "c := uint(1); d := uint(+(-(1 << c)))", res: "18446744073709551614"},
+		{src: "e, f := uint32(0), uint32(0); f = 1 << -(e * 2)", res: "1"},
+		{src: "p := uint(0xdead); byte((1 << (p & 7)) - 1)", res: "31"},
+		{pre: func() { eval(t, i, "const k uint = 1 << 17") }, src: "int(k)", res: "131072"},
+	})
+}
+
+func TestOpVarConst(t *testing.T) {
+	i := interp.New(interp.Options{})
+	runTests(t, i, []testCase{
+		{pre: func() { eval(t, i, "const a uint = 8 + 2") }, src: "a", res: "10"},
+		{src: "b := uint(5); a+b", res: "15"},
+		{src: "b := uint(5); b+a", res: "15"},
+		{src: "b := uint(5); b>a", res: "false"},
+	})
+}
+
 func TestEvalStar(t *testing.T) {
 	i := interp.New(interp.Options{})
 	runTests(t, i, []testCase{

interp/run.go

@@ -108,10 +108,53 @@ func (interp *Interpreter) run(n *node, cf *frame) {
 	runCfg(n.start, f)
 }
 
+// originalExecNode looks in the tree of nodes for the node which has exec,
+// aside from n, in order to know where n "inherited" that exec from.
+func originalExecNode(n *node, exec bltn) *node {
+	execAddr := reflect.ValueOf(exec).Pointer()
+	var originalNode *node
+	seen := make(map[int64]struct{})
+	root := n
+	for {
+		root = root.anc
+		if root == nil {
+			break
+		}
+		if _, ok := seen[root.index]; ok {
+			continue
+		}
+
+		root.Walk(func(wn *node) bool {
+			if _, ok := seen[wn.index]; ok {
+				return true
+			}
+			seen[wn.index] = struct{}{}
+			if wn.index == n.index {
+				return true
+			}
+			if wn.exec == nil {
+				return true
+			}
+			if reflect.ValueOf(wn.exec).Pointer() == execAddr {
+				originalNode = wn
+				return false
+			}
+			return true
+		}, nil)
+
+		if originalNode != nil {
+			break
+		}
+	}
+
+	return originalNode
+}
+
 // Functions set to run during execution of CFG.
 
 // runCfg executes a node AST by walking its CFG and running node builtin at each step.
 func runCfg(n *node, f *frame) {
+	var exec bltn
 	defer func() {
 		f.mutex.Lock()
 		f.recovered = recover()
@@ -119,14 +162,18 @@ func runCfg(n *node, f *frame) {
 			val[0].Call(val[1:])
 		}
 		if f.recovered != nil {
-			fmt.Println(n.cfgErrorf("panic"))
+			oNode := originalExecNode(n, exec)
+			if oNode == nil {
+				oNode = n
+			}
+			fmt.Println(oNode.cfgErrorf("panic"))
 			f.mutex.Unlock()
 			panic(f.recovered)
 		}
 		f.mutex.Unlock()
 	}()
 
-	for exec := n.exec; exec != nil && f.runid() == n.interp.runid(); {
+	for exec = n.exec; exec != nil && f.runid() == n.interp.runid(); {
 		exec = exec(f)
 	}
 }
@@ -343,10 +390,30 @@ func convert(n *node) {
 		return
 	}
 
+	if n.child[0].typ.cat == funcT && c.typ.cat == funcT {
+		value := genValue(c)
+		n.exec = func(f *frame) bltn {
+			n, ok := value(f).Interface().(*node)
+			if !ok || !n.typ.convertibleTo(c.typ) {
+				panic("cannot convert")
+			}
+			n1 := *n
+			n1.typ = c.typ
+			dest(f).Set(reflect.ValueOf(&n1))
+			return next
+		}
+		return
+	}
+
+	doConvert := true
 	var value func(*frame) reflect.Value
-	if c.typ.cat == funcT {
+	switch {
+	case c.typ.cat == funcT:
 		value = genFunctionWrapper(c)
-	} else {
+	case n.child[0].typ.cat == funcT && c.typ.cat == valueT:
+		doConvert = false
+		value = genValueNode(c)
+	default:
 		value = genValue(c)
 	}
 
@@ -367,7 +434,11 @@ func convert(n *node) {
 	}
 
 	n.exec = func(f *frame) bltn {
-		dest(f).Set(value(f).Convert(typ))
+		if doConvert {
+			dest(f).Set(value(f).Convert(typ))
+		} else {
+			dest(f).Set(value(f))
+		}
 		return next
 	}
 }
@@ -1116,6 +1187,7 @@ func callBin(n *node) {
 					c.val = reflect.Zero(argType)
 				}
 			}
+
 			switch c.typ.cat {
 			case funcT:
 				values = append(values, genFunctionWrapper(c))
@@ -1128,6 +1200,14 @@ func callBin(n *node) {
 				default:
 					values = append(values, genInterfaceWrapper(c, defType))
 				}
+			case ptrT:
+				if c.typ.val.cat == valueT {
+					values = append(values, genValue(c))
+				} else {
+					values = append(values, genInterfaceWrapper(c, defType))
+				}
+			case valueT:
+				values = append(values, genValue(c))
 			default:
 				values = append(values, genInterfaceWrapper(c, defType))
 			}
@@ -1719,6 +1799,11 @@ func neg(n *node) {
 			dest(f).SetInt(-value(f).Int())
 			return next
 		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		n.exec = func(f *frame) bltn {
+			dest(f).SetUint(-value(f).Uint())
+			return next
+		}
 	case reflect.Float32, reflect.Float64:
 		n.exec = func(f *frame) bltn {
 			dest(f).SetFloat(-value(f).Float())
@@ -2104,16 +2189,20 @@ func doComposite(n *node, hasType bool, keyed bool) {
 			val = c
 			fieldIndex = i
 		}
-		convertLiteralValue(val, typ.field[fieldIndex].typ.TypeOf())
+		ft := typ.field[fieldIndex].typ
+		rft := ft.TypeOf()
+		convertLiteralValue(val, rft)
 		switch {
+		case val.typ.cat == nilT:
+			values[fieldIndex] = func(*frame) reflect.Value { return reflect.New(rft).Elem() }
 		case val.typ.cat == funcT:
 			values[fieldIndex] = genFunctionWrapper(val)
 		case isArray(val.typ) && val.typ.val != nil && val.typ.val.cat == interfaceT:
 			values[fieldIndex] = genValueInterfaceArray(val)
-		case isRecursiveType(typ.field[fieldIndex].typ, typ.field[fieldIndex].typ.rtype):
-			values[fieldIndex] = genValueRecursiveInterface(val, typ.field[fieldIndex].typ.rtype)
-		case isInterface(typ.field[fieldIndex].typ):
-			values[fieldIndex] = genInterfaceWrapper(val, typ.field[fieldIndex].typ.rtype)
+		case isRecursiveType(ft, rft):
+			values[fieldIndex] = genValueRecursiveInterface(val, rft)
+		case isInterface(ft):
+			values[fieldIndex] = genInterfaceWrapper(val, rft)
 		default:
 			values[fieldIndex] = genValue(val)
 		}
@@ -3087,9 +3176,9 @@ func isNil(n *node) {
 		fnext := getExec(n.fnext)
 		if c0.typ.cat == interfaceT {
 			n.exec = func(f *frame) bltn {
-				vi := value(f).Interface().(valueInterface)
-				if (vi == valueInterface{} ||
-					vi.node.kind == basicLit && vi.node.typ.cat == nilT) {
+				v := value(f)
+				vi, ok := v.Interface().(valueInterface)
+				if ok && (vi == valueInterface{} || vi.node.kind == basicLit && vi.node.typ.cat == nilT) || v.IsNil() {
 					dest(f).SetBool(true)
 					return tnext
 				}
@@ -3109,7 +3198,12 @@ func isNil(n *node) {
 	} else {
 		if c0.typ.cat == interfaceT {
 			n.exec = func(f *frame) bltn {
-				dest(f).SetBool(value(f).Interface().(valueInterface) == valueInterface{})
+				v := value(f)
+				if vi, ok := v.Interface().(valueInterface); ok {
+					dest(f).SetBool(vi == valueInterface{} || vi.node.kind == basicLit && vi.node.typ.cat == nilT)
+				} else {
+					dest(f).SetBool(v.IsNil())
+				}
 				return tnext
 			}
 		} else {
@@ -3136,9 +3230,9 @@ func isNotNil(n *node) {
 		fnext := getExec(n.fnext)
 		if c0.typ.cat == interfaceT {
 			n.exec = func(f *frame) bltn {
-				vi := value(f).Interface().(valueInterface)
-				if (vi == valueInterface{} ||
-					vi.node.kind == basicLit && vi.node.typ.cat == nilT) {
+				v := value(f)
+				vi, ok := v.Interface().(valueInterface)
+				if ok && (vi == valueInterface{} || vi.node.kind == basicLit && vi.node.typ.cat == nilT) || v.IsNil() {
 					dest(f).SetBool(false)
 					return fnext
 				}
@@ -3158,7 +3252,12 @@ func isNotNil(n *node) {
 	} else {
 		if c0.typ.cat == interfaceT {
 			n.exec = func(f *frame) bltn {
-				dest(f).SetBool(!(value(f).Interface().(valueInterface) == valueInterface{}))
+				v := value(f)
+				if vi, ok := v.Interface().(valueInterface); ok {
+					dest(f).SetBool(!(vi == valueInterface{} || vi.node.kind == basicLit && vi.node.typ.cat == nilT))
+				} else {
+					dest(f).SetBool(!v.IsNil())
+				}
 				return tnext
 			}
 		} else {

interp/scope.go

@@ -72,26 +72,28 @@ type symbol struct {
 // execution to the index in frame, created exactly from the types layout.
 //
 type scope struct {
-	anc         *scope             // Ancestor upper scope
+	anc         *scope             // ancestor upper scope
+	child       []*scope           // included scopes
 	def         *node              // function definition node this scope belongs to, or nil
 	loop        *node              // loop exit node for break statement
 	loopRestart *node              // loop restart node for continue statement
 	pkgID       string             // unique id of package in which scope is defined
-	types       []reflect.Type     // Frame layout, may be shared by same level scopes
-	level       int                // Frame level: number of frame indirections to access var during execution
-	sym         map[string]*symbol // Map of symbols defined in this current scope
+	types       []reflect.Type     // frame layout, may be shared by same level scopes
+	level       int                // frame level: number of frame indirections to access var during execution
+	sym         map[string]*symbol // map of symbols defined in this current scope
 	global      bool               // true if scope refers to global space (single frame for universe and package level scopes)
 	iota        int                // iota value in this scope
 }
 
-// push creates a new scope and chain it to the current one.
+// push creates a new child scope and chain it to the current one.
 func (s *scope) push(indirect bool) *scope {
-	sc := scope{anc: s, level: s.level, sym: map[string]*symbol{}}
+	sc := &scope{anc: s, level: s.level, sym: map[string]*symbol{}}
+	s.child = append(s.child, sc)
 	if indirect {
 		sc.types = []reflect.Type{}
 		sc.level = s.level + 1
 	} else {
-		// propagate size, types, def and global as scopes at same level share the same frame
+		// Propagate size, types, def and global as scopes at same level share the same frame.
 		sc.types = s.types
 		sc.def = s.def
 		sc.global = s.global
@@ -99,7 +101,7 @@ func (s *scope) push(indirect bool) *scope {
 	}
 	// inherit loop state and pkgID from ancestor
 	sc.loop, sc.loopRestart, sc.pkgID = s.loop, s.loopRestart, s.pkgID
-	return &sc
+	return sc
 }
 
 func (s *scope) pushBloc() *scope { return s.push(false) }
@@ -107,12 +109,20 @@ func (s *scope) pushFunc() *scope { return s.push(true) }
 
 func (s *scope) pop() *scope {
 	if s.level == s.anc.level {
-		// propagate size and types, as scopes at same level share the same frame
+		// Propagate size and types, as scopes at same level share the same frame.
 		s.anc.types = s.types
 	}
 	return s.anc
 }
 
+func (s *scope) upperLevel() *scope {
+	level := s.level
+	for s != nil && s.level == level {
+		s = s.anc
+	}
+	return s
+}
+
 // lookup searches for a symbol in the current scope, and upper ones if not found
 // it returns the symbol, the number of indirections level from the current scope
 // and status (false if no result).
@@ -130,6 +140,20 @@ func (s *scope) lookup(ident string) (*symbol, int, bool) {
 	return nil, 0, false
 }
 
+// lookdown searches for a symbol in the current scope and included ones, recursively.
+// It returns the first found symbol and true, or nil and false.
+func (s *scope) lookdown(ident string) (*symbol, bool) {
+	if sym, ok := s.sym[ident]; ok {
+		return sym, true
+	}
+	for _, c := range s.child {
+		if sym, ok := c.lookdown(ident); ok {
+			return sym, true
+		}
+	}
+	return nil, false
+}
+
 func (s *scope) rangeChanType(n *node) *itype {
 	if sym, _, found := s.lookup(n.child[1].ident); found {
 		if t := sym.typ; len(n.child) == 3 && t != nil && (t.cat == chanT || t.cat == chanRecvT) {

interp/typecheck.go

@@ -217,6 +217,7 @@ var binaryOpPredicates = opPredicates{
 // binaryExpr type checks a binary expression.
 func (check typecheck) binaryExpr(n *node) error {
 	c0, c1 := n.child[0], n.child[1]
+
 	a := n.action
 	if isAssignAction(a) {
 		a--
@@ -226,6 +227,21 @@ func (check typecheck) binaryExpr(n *node) error {
 		return check.shift(n)
 	}
 
+	switch n.action {
+	case aRem:
+		if zeroConst(c1) {
+			return n.cfgErrorf("invalid operation: division by zero")
+		}
+	case aQuo:
+		if zeroConst(c1) {
+			return n.cfgErrorf("invalid operation: division by zero")
+		}
+		if c0.rval.IsValid() && c1.rval.IsValid() {
+			// Avoid constant conversions below to ensure correct constant integer quotient.
+			return nil
+		}
+	}
+
 	_ = check.convertUntyped(c0, c1.typ)
 	_ = check.convertUntyped(c1, c0.typ)
 
@@ -241,16 +257,13 @@ func (check typecheck) binaryExpr(n *node) error {
 	if err := check.op(binaryOpPredicates, a, n, c0, t0); err != nil {
 		return err
 	}
-
-	switch n.action {
-	case aQuo, aRem:
-		if (c0.typ.untyped || isInt(t0)) && c1.typ.untyped && constant.Sign(c1.rval.Interface().(constant.Value)) == 0 {
-			return n.cfgErrorf("invalid operation: division by zero")
-		}
-	}
 	return nil
 }
 
+func zeroConst(n *node) bool {
+	return n.typ.untyped && constant.Sign(n.rval.Interface().(constant.Value)) == 0
+}
+
 func (check typecheck) index(n *node, max int) error {
 	if err := check.convertUntyped(n, &itype{cat: intT, name: "int"}); err != nil {
 		return err
@@ -621,16 +634,13 @@ func (check typecheck) conversion(n *node, typ *itype) error {
 	if !ok {
 		return n.cfgErrorf("cannot convert expression of type %s to type %s", n.typ.id(), typ.id())
 	}
-
-	if n.typ.untyped {
-		if isInterface(typ) || c != nil && !isConstType(typ) {
-			typ = n.typ.defaultType()
-		}
-		if err := check.convertUntyped(n, typ); err != nil {
-			return err
-		}
+	if !n.typ.untyped || c == nil {
+		return nil
 	}
-	return nil
+	if isInterface(typ) || !isConstType(typ) {
+		typ = n.typ.defaultType()
+	}
+	return check.convertUntyped(n, typ)
 }
 
 type param struct {

interp/value.go

@@ -342,6 +342,10 @@ func vInt(v reflect.Value) (i int64) {
 }
 
 func vUint(v reflect.Value) (i uint64) {
+	if c := vConstantValue(v); c != nil {
+		i, _ = constant.Uint64Val(constant.ToInt(c))
+		return i
+	}
 	switch v.Type().Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		i = uint64(v.Int())

stdlib/go1_15_archive_tar.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract archive/tar'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_archive_zip.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract archive/zip'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_bufio.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract bufio'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_bytes.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract bytes'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_compress_bzip2.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract compress/bzip2'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_compress_flate.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract compress/flate'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_compress_gzip.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract compress/gzip'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_compress_lzw.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract compress/lzw'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_compress_zlib.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract compress/zlib'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_container_heap.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract container/heap'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_container_list.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract container/list'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_container_ring.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract container/ring'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_context.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract context'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_aes.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/aes'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_cipher.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/cipher'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_des.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/des'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_dsa.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/dsa'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_ecdsa.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/ecdsa'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_ed25519.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/ed25519'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_elliptic.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/elliptic'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_hmac.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/hmac'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_md5.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/md5'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_rand.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/rand'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_rc4.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/rc4'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_rsa.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/rsa'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_sha1.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/sha1'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_sha256.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/sha256'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_sha512.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/sha512'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_subtle.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/subtle'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_tls.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/tls'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_x509.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/x509'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_crypto_x509_pkix.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract crypto/x509/pkix'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_database_sql.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract database/sql'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_database_sql_driver.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract database/sql/driver'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_debug_dwarf.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract debug/dwarf'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_debug_elf.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract debug/elf'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_debug_gosym.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract debug/gosym'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_debug_macho.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract debug/macho'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_debug_pe.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract debug/pe'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_debug_plan9obj.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract debug/plan9obj'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_ascii85.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/ascii85'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_asn1.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/asn1'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_base32.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/base32'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_base64.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/base64'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_binary.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/binary'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_csv.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/csv'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_gob.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/gob'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_hex.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/hex'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_json.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/json'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_pem.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/pem'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_encoding_xml.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract encoding/xml'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_errors.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract errors'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_expvar.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract expvar'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_flag.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract flag'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_fmt.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract fmt'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_ast.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/ast'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_build.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/build'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_constant.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/constant'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_doc.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/doc'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_format.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/format'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_importer.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/importer'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_parser.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/parser'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_printer.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/printer'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_scanner.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/scanner'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_token.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/token'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_go_types.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract go/types'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_hash.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract hash'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_hash_adler32.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract hash/adler32'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_hash_crc32.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract hash/crc32'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_hash_crc64.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract hash/crc64'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_hash_fnv.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract hash/fnv'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_hash_maphash.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract hash/maphash'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_html.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract html'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_html_template.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract html/template'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib
 

stdlib/go1_15_image.go

@@ -1,6 +1,6 @@
 // Code generated by 'yaegi extract image'. DO NOT EDIT.
 
-// +build go1.15,!go1.16
+// +build go1.15
 
 package stdlib