interp: fix setting of interface value from nested function calls

Fixes #1320 and #1294.

_test/cli1.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net"
 	"net/http"
@@ -13,7 +13,7 @@ func client(uri string) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/cli2.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net"
 	"net/http"
@@ -21,7 +21,7 @@ func client(uri string) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/cli3.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"net/http/httptest"
@@ -13,7 +13,7 @@ func client(uri string) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/cli4.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"net/http/httptest"
@@ -40,7 +40,7 @@ func client(uri string) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/cli5.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"net/http/httptest"
@@ -40,7 +40,7 @@ func client(uri string) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/cli6.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"net/http/httptest"
@@ -41,7 +41,7 @@ func client(uri string) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/file_access.go

@@ -2,12 +2,11 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 )
 
 func main() {
-	file, err := ioutil.TempFile("", "yeagibench")
+	file, err := os.CreateTemp("", "yeagibench")
 	if err != nil {
 		panic(err)
 	}
@@ -23,7 +22,7 @@ func main() {
 		panic(err)
 	}
 
-	b, err := ioutil.ReadFile(file.Name())
+	b, err := os.ReadFile(file.Name())
 	if err != nil {
 		panic(err)
 	}

_test/io2.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"strings"
 )
@@ -10,7 +10,7 @@ import (
 func main() {
 	r := strings.NewReader("Go is a general-purpose language designed with systems programming in mind.")
 
-	b, err := ioutil.ReadAll(r)
+	b, err := io.ReadAll(r)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/issue-1187.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"io"
-	"io/ioutil"
 	"os"
 )
 
@@ -13,7 +12,7 @@ type sink interface {
 
 func newSink() sink {
 	// return os.Stdout	// Stdout is special in yaegi tests
-	file, err := ioutil.TempFile("", "yaegi-test.*")
+	file, err := os.CreateTemp("", "yaegi-test.*")
 	if err != nil {
 		panic(err)
 	}

_test/issue-1260.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 )
 
@@ -37,7 +36,7 @@ func (s *Sink2) Close() error                { println("in Close", s.name); retu
 func newS2(name string) Sink                 { return Sink1{name} }
 
 func main() {
-	tmpfile, err := ioutil.TempFile("", "xxx")
+	tmpfile, err := os.CreateTemp("", "xxx")
 	if err != nil {
 		panic(err)
 	}

_test/issue-1311.go

@@ -0,0 +1,19 @@
+package main
+
+type T struct {
+	v interface{}
+}
+
+func f() (ret int64, err error) {
+	ret += 2
+	return
+}
+
+func main() {
+	t := &T{}
+	t.v, _ = f()
+	println(t.v.(int64))
+}
+
+// Output:
+// 2

_test/issue-1315.go

@@ -0,0 +1,32 @@
+package main
+
+type Intf interface {
+	M()
+}
+
+type T struct {
+	s string
+}
+
+func (t *T) M() { println("in M") }
+
+func f(i interface{}) {
+	switch j := i.(type) {
+	case Intf:
+		j.M()
+	default:
+		println("default")
+	}
+}
+
+func main() {
+	var i Intf
+	var k interface{} = 1
+	i = &T{"hello"}
+	f(i)
+	f(k)
+}
+
+// Output:
+// in M
+// default

_test/issue-1320.go

@@ -0,0 +1,29 @@
+package main
+
+type Pooler interface {
+	Get() string
+}
+
+type baseClient struct {
+	connPool Pooler
+}
+
+type connPool struct {
+	name string
+}
+
+func (c *connPool) Get() string { return c.name }
+
+func newBaseClient(i int, p Pooler) *baseClient {
+	return &baseClient{connPool: p}
+}
+
+func newConnPool() *connPool { return &connPool{name: "connPool"} }
+
+func main() {
+	b := newBaseClient(0, newConnPool())
+	println(b.connPool.(*connPool).name)
+}
+
+// Output:
+// connPool

_test/issue-558.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"strings"
 )
@@ -36,7 +35,7 @@ type pipe struct {
 
 func newReadAutoCloser(r io.Reader) readAutoCloser {
 	if _, ok := r.(io.Closer); !ok {
-		return readAutoCloser{ioutil.NopCloser(r)}
+		return readAutoCloser{io.NopCloser(r)}
 	}
 	return readAutoCloser{r.(io.ReadCloser)}
 }
@@ -44,7 +43,7 @@ func newReadAutoCloser(r io.Reader) readAutoCloser {
 func main() {
 	p := &pipe{}
 	p.Reader = newReadAutoCloser(strings.NewReader("test"))
-	b, err := ioutil.ReadAll(p.Reader)
+	b, err := io.ReadAll(p.Reader)
 	if err != nil {
 		log.Fatal(err)
 	}

_test/os0.go

@@ -2,11 +2,11 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 )
 
 func main() {
-	_, err := ioutil.ReadFile("__NotExisting__")
+	_, err := os.ReadFile("__NotExisting__")
 	if err != nil {
 		fmt.Println(err.Error())
 	}

cmd/yaegi/run.go

@@ -4,7 +4,6 @@ import (
 	"flag"
 	"fmt"
 	"go/build"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"strconv"
@@ -135,7 +134,7 @@ func isFile(path string) bool {
 }
 
 func runFile(i *interp.Interpreter, path string, noAutoImport bool) error {
-	b, err := ioutil.ReadFile(path)
+	b, err := os.ReadFile(path)
 	if err != nil {
 		return err
 	}

cmd/yaegi/yaegi_test.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -38,7 +37,7 @@ func applyCIMultiplier(timeout time.Duration) time.Duration {
 }
 
 func TestYaegiCmdCancel(t *testing.T) {
-	tmp, err := ioutil.TempDir("", "yaegi-")
+	tmp, err := os.MkdirTemp("", "yaegi-")
 	if err != nil {
 		t.Fatalf("failed to create tmp directory: %v", err)
 	}

internal/cmd/genop/genop.go

@@ -3,8 +3,8 @@ package main
 import (
 	"bytes"
 	"go/format"
-	"io/ioutil"
 	"log"
+	"os"
 	"strings"
 	"text/template"
 )
@@ -1183,7 +1183,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	if err = ioutil.WriteFile("op.go", source, 0o666); err != nil {
+	if err = os.WriteFile("op.go", source, 0o666); err != nil {
 		log.Fatal(err)
 	}
 }

interp/cfg.go

@@ -64,6 +64,9 @@ func (interp *Interpreter) cfg(root *node, sc *scope, importPath, pkgName string
 		if err != nil {
 			return false
 		}
+		if n.scope == nil {
+			n.scope = sc
+		}
 		switch n.kind {
 		case binaryExpr, unaryExpr, parenExpr:
 			if isBoolAction(n) {
@@ -662,7 +665,12 @@ func (interp *Interpreter) cfg(root *node, sc *scope, importPath, pkgName string
 				if r := lc.child[0].typ.numOut(); r != l {
 					err = n.cfgErrorf("assignment mismatch: %d variables but %s returns %d values", l, lc.child[0].name(), r)
 				}
-				n.gen = nop
+				if isBinCall(lc, sc) {
+					n.gen = nop
+				} else {
+					// TODO (marc): skip if no conversion or wrapping is needed.
+					n.gen = assignFromCall
+				}
 			case indexExpr:
 				lc.gen = getIndexMap2
 				n.gen = nop
@@ -970,7 +978,7 @@ func (interp *Interpreter) cfg(root *node, sc *scope, importPath, pkgName string
 					n.typ = c0.typ
 					n.findex = sc.add(n.typ)
 				}
-			case isBinCall(n):
+			case isBinCall(n, sc):
 				err = check.arguments(n, n.child[1:], n.child[0], n.action == aCallSlice)
 				if err != nil {
 					break
@@ -2019,7 +2027,12 @@ func compDefineX(sc *scope, n *node) error {
 		if len(types) != l {
 			return n.cfgErrorf("assignment mismatch: %d variables but %s returns %d values", l, src.child[0].name(), len(types))
 		}
-		n.gen = nop
+		if isBinCall(src, sc) {
+			n.gen = nop
+		} else {
+			// TODO (marc): skip if no conversion or wrapping is needed.
+			n.gen = assignFromCall
+		}
 
 	case indexExpr:
 		types = append(types, src.typ, sc.getType("bool"))
@@ -2468,8 +2481,19 @@ func isCall(n *node) bool {
 	return n.action == aCall || n.action == aCallSlice
 }
 
-func isBinCall(n *node) bool {
+func isBinCall(n *node, sc *scope) bool {
-	return isCall(n) && n.child[0].typ.cat == valueT && n.child[0].typ.rtype.Kind() == reflect.Func
+	if !isCall(n) || len(n.child) == 0 {
+		return false
+	}
+	c0 := n.child[0]
+	if c0.typ == nil {
+		// If called early in parsing, child type may not be known yet.
+		c0.typ, _ = nodeType(n.interp, sc, c0)
+		if c0.typ == nil {
+			return false
+		}
+	}
+	return c0.typ.cat == valueT && c0.typ.rtype.Kind() == reflect.Func
 }
 
 func isOffsetof(n *node) bool {

interp/dot.go

@@ -3,7 +3,6 @@ package interp
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"os/exec"
 	"path/filepath"
@@ -69,7 +68,7 @@ func (nopCloser) Close() error { return nil }
 // dotWriter returns an output stream to a dot(1) co-process where to write data in .dot format.
 func dotWriter(dotCmd string) io.WriteCloser {
 	if dotCmd == "" {
-		return nopCloser{ioutil.Discard}
+		return nopCloser{io.Discard}
 	}
 	fields := strings.Fields(dotCmd)
 	cmd := exec.Command(fields[0], fields[1:]...)

interp/interp_consistent_test.go

@@ -2,7 +2,7 @@ package interp_test
 
 import (
 	"go/build"
-	"io/ioutil"
+	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -26,7 +26,7 @@ func TestInterpConsistencyBuild(t *testing.T) {
 	}
 
 	baseDir := filepath.Join("..", "_test")
-	files, err := ioutil.ReadDir(baseDir)
+	files, err := os.ReadDir(baseDir)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -145,7 +145,7 @@ func TestInterpConsistencyBuild(t *testing.T) {
 			if err = w.Close(); err != nil {
 				t.Fatal(err)
 			}
-			outInterp, err := ioutil.ReadAll(r)
+			outInterp, err := io.ReadAll(r)
 			if err != nil {
 				t.Fatal(err)
 			}

interp/interp_eval_test.go

@@ -6,7 +6,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
@@ -885,7 +884,7 @@ func TestMultiEval(t *testing.T) {
 	if err = w.Close(); err != nil {
 		t.Fatal(err)
 	}
-	outInterp, err := ioutil.ReadAll(r)
+	outInterp, err := io.ReadAll(r)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -916,7 +915,7 @@ func TestMultiEvalNoName(t *testing.T) {
 		t.Fatal(err)
 	}
 	for k, v := range names {
-		data, err := ioutil.ReadFile(filepath.Join(f.Name(), v))
+		data, err := os.ReadFile(filepath.Join(f.Name(), v))
 		if err != nil {
 			t.Fatal(err)
 		}

interp/interp_file_test.go

@@ -5,7 +5,6 @@ import (
 	"go/build"
 	"go/parser"
 	"go/token"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -26,7 +25,7 @@ func TestFile(t *testing.T) {
 	_ = os.Setenv("YAEGI_SPECIAL_STDIO", "1")
 
 	baseDir := filepath.Join("..", "_test")
-	files, err := ioutil.ReadDir(baseDir)
+	files, err := os.ReadDir(baseDir)
 	if err != nil {
 		t.Fatal(err)
 	}

interp/program.go

@@ -3,7 +3,7 @@ package interp
 import (
 	"context"
 	"go/ast"
-	"io/ioutil"
+	"os"
 	"reflect"
 	"runtime"
 	"runtime/debug"
@@ -28,7 +28,7 @@ func (interp *Interpreter) CompilePath(path string) (*Program, error) {
 		return nil, err
 	}
 
-	b, err := ioutil.ReadFile(path)
+	b, err := os.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}

interp/run.go

@@ -616,6 +616,34 @@ func convert(n *node) {
 	}
 }
 
+// assignFromCall assigns values from a function call.
+func assignFromCall(n *node) {
+	ncall := n.lastChild()
+	l := len(n.child) - 1
+	if n.anc.kind == varDecl && n.child[l-1].isType(n.scope) {
+		// Ignore the type in the assignment if it is part of a variable declaration.
+		l--
+	}
+	dvalue := make([]func(*frame) reflect.Value, l)
+	for i := range dvalue {
+		if n.child[i].ident == "_" {
+			continue
+		}
+		dvalue[i] = genValue(n.child[i])
+	}
+	next := getExec(n.tnext)
+	n.exec = func(f *frame) bltn {
+		for i, v := range dvalue {
+			if v == nil {
+				continue
+			}
+			s := f.data[ncall.findex+i]
+			v(f).Set(s)
+		}
+		return next
+	}
+}
+
 func assign(n *node) {
 	next := getExec(n.tnext)
 	dvalue := make([]func(*frame) reflect.Value, n.nleft)
@@ -957,7 +985,7 @@ func genFunctionWrapper(n *node) func(*frame) reflect.Value {
 			} else {
 				// Copy method receiver as first argument.
 				src, dest := rcvr(f), d[numRet]
-				sk, dk := src.Type().Kind(), dest.Type().Kind()
+				sk, dk := src.Kind(), dest.Kind()
 				switch {
 				case sk == reflect.Ptr && dk != reflect.Ptr:
 					dest.Set(src.Elem())
@@ -1097,27 +1125,28 @@ func methodByName(value reflect.Value, name string) reflect.Value {
 func call(n *node) {
 	goroutine := n.anc.kind == goStmt
 	var method bool
-	value := genValue(n.child[0])
+	c0 := n.child[0]
+	value := genValue(c0)
 	var values []func(*frame) reflect.Value
 
 	recvIndexLater := false
 	switch {
-	case n.child[0].recv != nil:
+	case c0.recv != nil:
 		// Compute method receiver value.
-		values = append(values, genValueRecv(n.child[0]))
+		values = append(values, genValueRecv(c0))
 		method = true
-	case len(n.child[0].child) > 0 && n.child[0].child[0].typ != nil && isInterfaceSrc(n.child[0].child[0].typ):
+	case len(c0.child) > 0 && c0.child[0].typ != nil && isInterfaceSrc(c0.child[0].typ):
 		recvIndexLater = true
-		values = append(values, genValueBinRecv(n.child[0], &receiver{node: n.child[0].child[0]}))
+		values = append(values, genValueBinRecv(c0, &receiver{node: c0.child[0]}))
 		value = genValueBinMethodOnInterface(n, value)
 		method = true
-	case n.child[0].action == aMethod:
+	case c0.action == aMethod:
 		// Add a place holder for interface method receiver.
 		values = append(values, nil)
 		method = true
 	}
 
-	numRet := len(n.child[0].typ.ret)
+	numRet := len(c0.typ.ret)
 	variadic := variadicPos(n)
 	child := n.child[1:]
 	tnext := getExec(n.tnext)
@@ -1125,27 +1154,40 @@ func call(n *node) {
 
 	// Compute input argument value functions.
 	for i, c := range child {
+		var arg *itype
+		if variadic >= 0 && i >= variadic {
+			arg = c0.typ.arg[variadic].val
+		} else {
+			arg = c0.typ.arg[i]
+		}
 		switch {
-		case isBinCall(c):
+		case isBinCall(c, c.scope):
 			// Handle nested function calls: pass returned values as arguments.
 			numOut := c.child[0].typ.rtype.NumOut()
 			for j := 0; j < numOut; j++ {
 				ind := c.findex + j
-				values = append(values, func(f *frame) reflect.Value { return f.data[ind] })
+				if !isInterfaceSrc(arg) || isEmptyInterface(arg) {
+					values = append(values, func(f *frame) reflect.Value { return f.data[ind] })
+					continue
+				}
+				values = append(values, func(f *frame) reflect.Value {
+					return reflect.ValueOf(valueInterface{value: f.data[ind]})
+				})
 			}
 		case isRegularCall(c):
 			// Arguments are return values of a nested function call.
-			for j := range c.child[0].typ.ret {
+			cc0 := c.child[0]
+			for j := range cc0.typ.ret {
 				ind := c.findex + j
-				values = append(values, func(f *frame) reflect.Value { return f.data[ind] })
+				if !isInterfaceSrc(arg) || isEmptyInterface(arg) {
+					values = append(values, func(f *frame) reflect.Value { return f.data[ind] })
+					continue
+				}
+				values = append(values, func(f *frame) reflect.Value {
+					return reflect.ValueOf(valueInterface{node: cc0.typ.ret[j].node, value: f.data[ind]})
+				})
 			}
 		default:
-			var arg *itype
-			if variadic >= 0 && i >= variadic {
-				arg = n.child[0].typ.arg[variadic].val
-			} else {
-				arg = n.child[0].typ.arg[i]
-			}
 			if c.kind == basicLit || c.rval.IsValid() {
 				argType := arg.TypeOf()
 				convertLiteralValue(c, argType)
@@ -1165,10 +1207,11 @@ func call(n *node) {
 	}
 
 	// Compute output argument value functions.
-	rtypes := n.child[0].typ.ret
+	rtypes := c0.typ.ret
 	rvalues := make([]func(*frame) reflect.Value, len(rtypes))
 	switch n.anc.kind {
 	case defineXStmt, assignXStmt:
+		l := n.level
 		for i := range rvalues {
 			c := n.anc.child[i]
 			switch {
@@ -1177,7 +1220,8 @@ func call(n *node) {
 			case isInterfaceSrc(c.typ) && !isEmptyInterface(c.typ) && !isInterfaceSrc(rtypes[i]):
 				rvalues[i] = genValueInterfaceValue(c)
 			default:
-				rvalues[i] = genValue(c)
+				j := n.findex + i
+				rvalues[i] = func(f *frame) reflect.Value { return getFrame(f, l).data[j] }
 			}
 		}
 	case returnStmt:
@@ -1198,7 +1242,7 @@ func call(n *node) {
 
 	if n.anc.kind == deferStmt {
 		// Store function call in frame for deferred execution.
-		value = genFunctionWrapper(n.child[0])
+		value = genFunctionWrapper(c0)
 		if method {
 			// The receiver is already passed in the function wrapper, skip it.
 			values = values[1:]
@@ -1328,7 +1372,7 @@ func call(n *node) {
 					// The !val.IsZero is to work around a recursive struct zero interface
 					// issue. Once there is a better way to handle this case, the dest
 					// can just be set.
-					if !val.IsZero() || dest[i].Type().Kind() == reflect.Interface {
+					if !val.IsZero() || dest[i].Kind() == reflect.Interface {
 						dest[i].Set(val)
 					}
 				}
@@ -1404,7 +1448,7 @@ func callBin(n *node) {
 		}
 
 		switch {
-		case isBinCall(c):
+		case isBinCall(c, c.scope):
 			// Handle nested function calls: pass returned values as arguments
 			numOut := c.child[0].typ.rtype.NumOut()
 			for j := 0; j < numOut; j++ {
@@ -1566,7 +1610,7 @@ func callBin(n *node) {
 				}
 				out := callFn(value(f), in)
 				for i := 0; i < len(out); i++ {
-					if out[i].Type().Kind() == reflect.Func {
+					if out[i].Kind() == reflect.Func {
 						getFrame(f, n.level).data[n.findex+i] = out[i]
 					} else {
 						getFrame(f, n.level).data[n.findex+i].Set(out[i])
@@ -2533,7 +2577,7 @@ func doCompositeBinStruct(n *node, hasType bool) {
 		}
 		d := value(f)
 		switch {
-		case d.Type().Kind() == reflect.Ptr:
+		case d.Kind() == reflect.Ptr:
 			d.Set(s.Addr())
 		default:
 			d.Set(s)
@@ -2611,7 +2655,7 @@ func doComposite(n *node, hasType bool, keyed bool) {
 		}
 		d := value(f)
 		switch {
-		case d.Type().Kind() == reflect.Ptr:
+		case d.Kind() == reflect.Ptr:
 			d.Set(a.Addr())
 		case destInterface:
 			if len(destType(n).field) > 0 {
@@ -2867,12 +2911,13 @@ func _case(n *node) {
 					if typ.cat == nilT && v.IsNil() {
 						return tnext
 					}
-					if typ.TypeOf().String() == t.String() {
+					rtyp := typ.TypeOf()
+					if rtyp != nil && rtyp.String() == t.String() && implementsInterface(v, typ) {
 						destValue(f).Set(v.Elem())
 						return tnext
 					}
 					ival := v.Interface()
-					if ival != nil && typ.TypeOf().String() == reflect.TypeOf(ival).String() {
+					if ival != nil && rtyp != nil && rtyp.String() == reflect.TypeOf(ival).String() {
 						destValue(f).Set(v.Elem())
 						return tnext
 					}
@@ -2935,6 +2980,22 @@ func _case(n *node) {
 	}
 }
 
+func implementsInterface(v reflect.Value, t *itype) bool {
+	rt := v.Type()
+	if t.cat == valueT {
+		return rt.Implements(t.rtype)
+	}
+	vt := &itype{cat: valueT, rtype: rt}
+	if vt.methods().contains(t.methods()) {
+		return true
+	}
+	vi, ok := v.Interface().(valueInterface)
+	if !ok {
+		return false
+	}
+	return vi.node != nil && vi.node.typ.methods().contains(t.methods())
+}
+
 func appendSlice(n *node) {
 	dest := genValueOutput(n, n.typ.rtype)
 	next := getExec(n.tnext)
@@ -3169,7 +3230,7 @@ func _len(n *node) {
 		val := value
 		value = func(f *frame) reflect.Value {
 			v := val(f).Elem()
-			for v.Type().Kind() == reflect.Ptr {
+			for v.Kind() == reflect.Ptr {
 				v = v.Elem()
 			}
 			return v

interp/src_test.go

@@ -1,7 +1,6 @@
 package interp
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -50,7 +49,7 @@ func Test_effectivePkg(t *testing.T) {
 
 func Test_pkgDir(t *testing.T) {
 	// create GOPATH
-	goPath, err := ioutil.TempDir("", "pkdir")
+	goPath, err := os.MkdirTemp("", "pkdir")
 	if err != nil {
 		t.Fatal(err)
 	}

interp/typecheck.go

@@ -850,7 +850,7 @@ func (check typecheck) builtin(name string, n *node, child []*node, ellipsis boo
 			return params[0].nod.cfgErrorf("first argument to delete must be map; have %s", typ.id())
 		}
 		ktyp := params[1].Type()
-		if !ktyp.assignableTo(typ.key) {
+		if typ.key != nil && !ktyp.assignableTo(typ.key) {
 			return params[1].nod.cfgErrorf("cannot use %s as type %s in delete", ktyp.id(), typ.key.id())
 		}
 	case bltnMake:

interp/value.go

@@ -147,7 +147,7 @@ func genValueAsFunctionWrapper(n *node) func(*frame) reflect.Value {
 			return reflect.New(typ).Elem()
 		}
 		vn, ok := v.Interface().(*node)
-		if ok && vn.rval.IsValid() && vn.rval.Type().Kind() == reflect.Func {
+		if ok && vn.rval.Kind() == reflect.Func {
 			// The node value is already a callable func, no need to wrap it.
 			return vn.rval
 		}
@@ -160,7 +160,7 @@ func genValueAs(n *node, t reflect.Type) func(*frame) reflect.Value {
 
 	return func(f *frame) reflect.Value {
 		v := value(f)
-		switch v.Type().Kind() {
+		switch v.Kind() {
 		case reflect.Chan, reflect.Func, reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice, reflect.UnsafePointer:
 			if v.IsNil() {
 				return reflect.New(t).Elem()
@@ -338,13 +338,13 @@ func getConcreteValue(val reflect.Value) reflect.Value {
 	if v.NumMethod() > 0 {
 		return v
 	}
-	if v.Type().Kind() != reflect.Struct {
+	if v.Kind() != reflect.Struct {
 		return v
 	}
 	// Search a concrete value in fields of an emulated interface.
 	for i := v.NumField() - 1; i >= 0; i-- {
 		vv := v.Field(i)
-		if vv.Type().Kind() == reflect.Interface {
+		if vv.Kind() == reflect.Interface {
 			vv = vv.Elem()
 		}
 		if vv.IsValid() {
@@ -430,7 +430,7 @@ func vInt(v reflect.Value) (i int64) {
 		i, _ = constant.Int64Val(constant.ToInt(c))
 		return i
 	}
-	switch v.Type().Kind() {
+	switch v.Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		i = v.Int()
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
@@ -448,7 +448,7 @@ func vUint(v reflect.Value) (i uint64) {
 		i, _ = constant.Uint64Val(constant.ToInt(c))
 		return i
 	}
-	switch v.Type().Kind() {
+	switch v.Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		i = uint64(v.Int())
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
@@ -468,7 +468,7 @@ func vComplex(v reflect.Value) (c complex128) {
 		img, _ := constant.Float64Val(constant.Imag(c))
 		return complex(rel, img)
 	}
-	switch v.Type().Kind() {
+	switch v.Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		c = complex(float64(v.Int()), 0)
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
@@ -486,7 +486,7 @@ func vFloat(v reflect.Value) (i float64) {
 		i, _ = constant.Float64Val(constant.ToFloat(c))
 		return i
 	}
-	switch v.Type().Kind() {
+	switch v.Kind() {
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		i = float64(v.Int())
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:

stdlib/go1_16_go_build_constraint.go

@@ -0,0 +1,48 @@
+// Code generated by 'yaegi extract go/build/constraint'. DO NOT EDIT.
+
+// +build go1.16,!go1.17
+
+package stdlib
+
+import (
+	"go/build/constraint"
+	"reflect"
+)
+
+func init() {
+	Symbols["go/build/constraint/constraint"] = map[string]reflect.Value{
+		// function, constant and variable definitions
+		"IsGoBuild":      reflect.ValueOf(constraint.IsGoBuild),
+		"IsPlusBuild":    reflect.ValueOf(constraint.IsPlusBuild),
+		"Parse":          reflect.ValueOf(constraint.Parse),
+		"PlusBuildLines": reflect.ValueOf(constraint.PlusBuildLines),
+
+		// type definitions
+		"AndExpr":     reflect.ValueOf((*constraint.AndExpr)(nil)),
+		"Expr":        reflect.ValueOf((*constraint.Expr)(nil)),
+		"NotExpr":     reflect.ValueOf((*constraint.NotExpr)(nil)),
+		"OrExpr":      reflect.ValueOf((*constraint.OrExpr)(nil)),
+		"SyntaxError": reflect.ValueOf((*constraint.SyntaxError)(nil)),
+		"TagExpr":     reflect.ValueOf((*constraint.TagExpr)(nil)),
+
+		// interface wrapper definitions
+		"_Expr": reflect.ValueOf((*_go_build_constraint_Expr)(nil)),
+	}
+}
+
+// _go_build_constraint_Expr is an interface wrapper for Expr type
+type _go_build_constraint_Expr struct {
+	IValue  interface{}
+	WEval   func(ok func(tag string) bool) bool
+	WString func() string
+}
+
+func (W _go_build_constraint_Expr) Eval(ok func(tag string) bool) bool {
+	return W.WEval(ok)
+}
+func (W _go_build_constraint_Expr) String() string {
+	if W.WString == nil {
+		return ""
+	}
+	return W.WString()
+}

stdlib/go1_17_go_build_constraint.go

@@ -0,0 +1,49 @@
+// Code generated by 'yaegi extract go/build/constraint'. DO NOT EDIT.
+
+//go:build go1.17
+// +build go1.17
+
+package stdlib
+
+import (
+	"go/build/constraint"
+	"reflect"
+)
+
+func init() {
+	Symbols["go/build/constraint/constraint"] = map[string]reflect.Value{
+		// function, constant and variable definitions
+		"IsGoBuild":      reflect.ValueOf(constraint.IsGoBuild),
+		"IsPlusBuild":    reflect.ValueOf(constraint.IsPlusBuild),
+		"Parse":          reflect.ValueOf(constraint.Parse),
+		"PlusBuildLines": reflect.ValueOf(constraint.PlusBuildLines),
+
+		// type definitions
+		"AndExpr":     reflect.ValueOf((*constraint.AndExpr)(nil)),
+		"Expr":        reflect.ValueOf((*constraint.Expr)(nil)),
+		"NotExpr":     reflect.ValueOf((*constraint.NotExpr)(nil)),
+		"OrExpr":      reflect.ValueOf((*constraint.OrExpr)(nil)),
+		"SyntaxError": reflect.ValueOf((*constraint.SyntaxError)(nil)),
+		"TagExpr":     reflect.ValueOf((*constraint.TagExpr)(nil)),
+
+		// interface wrapper definitions
+		"_Expr": reflect.ValueOf((*_go_build_constraint_Expr)(nil)),
+	}
+}
+
+// _go_build_constraint_Expr is an interface wrapper for Expr type
+type _go_build_constraint_Expr struct {
+	IValue  interface{}
+	WEval   func(ok func(tag string) bool) bool
+	WString func() string
+}
+
+func (W _go_build_constraint_Expr) Eval(ok func(tag string) bool) bool {
+	return W.WEval(ok)
+}
+func (W _go_build_constraint_Expr) String() string {
+	if W.WString == nil {
+		return ""
+	}
+	return W.WString()
+}

stdlib/stdlib.go

@@ -32,7 +32,7 @@ func init() {
 //go:generate ../internal/cmd/extract/extract encoding/base64 encoding/binary encoding/csv encoding/gob
 //go:generate ../internal/cmd/extract/extract encoding/hex encoding/json encoding/pem encoding/xml
 //go:generate ../internal/cmd/extract/extract errors expvar flag fmt
-//go:generate ../internal/cmd/extract/extract go/ast go/build go/constant go/doc go/format go/importer
+//go:generate ../internal/cmd/extract/extract go/ast go/build go/build/constraint go/constant go/doc go/format go/importer
 //go:generate ../internal/cmd/extract/extract go/parser go/printer go/scanner go/token go/types
 //go:generate ../internal/cmd/extract/extract hash hash/adler32 hash/crc32 hash/crc64 hash/fnv hash/maphash
 //go:generate ../internal/cmd/extract/extract html html/template

stdlib/unsafe/unsafe_go1.17.go

@@ -31,7 +31,7 @@ func slice(i interface{}, l int) interface{} {
 	}
 
 	v := reflect.ValueOf(i)
-	if v.Type().Kind() != reflect.Ptr {
+	if v.Kind() != reflect.Ptr {
 		panic(errors.New("first argument to unsafe.Slice must be pointer"))
 	}
 	if v.IsNil() {