fix: reuse rather than re-import an already imported source package

_test/foo/bar.go

@@ -1,6 +1,8 @@
 package foo
 
-import "./boo"
+import "github.com/containous/yaegi/_test/foo/boo"
 
 var Bar = "BARR"
 var Boo = boo.Boo
+
+func init() { println("init foo") }

_test/foo/bir.go

@@ -0,0 +1,5 @@
+package foo
+
+import "github.com/containous/yaegi/_test/foo/boo"
+
+var Bir = boo.Boo + "22"

_test/foo/boo/boo.go

@@ -1,3 +1,5 @@
 package boo
 
 var Boo = "Boo"
+
+func init() { println("init boo") }

_test/import3.go

@@ -1,8 +1,10 @@
 package main
 
-import "./foo"
+import "github.com/containous/yaegi/_test/foo"
 
 func main() { println(foo.Bar, foo.Boo) }
 
 // Output:
+// init boo
+// init foo
 // BARR Boo

_test/import4.go

@@ -1,6 +1,6 @@
 package main
 
-import "./p1"
+import "github.com/containous/yaegi/_test/p1"
 
 func main() { println("num:", p1.Uint32()) }
 

_test/import5.go

@@ -0,0 +1,10 @@
+package main
+
+import boo "github.com/containous/yaegi/_test/foo"
+
+func main() { println(boo.Bar, boo.Boo, boo.Bir) }
+
+// Output:
+// init boo
+// init foo
+// BARR Boo Boo22

interp/gta.go

@@ -121,8 +121,11 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 				ipath = n.child[0].rval.String()
 				name = path.Base(ipath)
 			}
+			// Try to import a binary package first, or a source package
 			if interp.binPkg[ipath] != nil {
-				if name == "." {
+				switch name {
+				case "_": // no import of symbols
+				case ".": // import symbols in current scope
 					for n, v := range interp.binPkg[ipath] {
 						typ := v.Type()
 						if isBinType(v) {
@@ -130,14 +133,22 @@ func (interp *Interpreter) gta(root *node, rpath string) ([]*node, error) {
 						}
 						sc.sym[n] = &symbol{kind: binSym, typ: &itype{cat: valueT, rtype: typ}, rval: v}
 					}
-				} else {
+				default: // import symbols in package namespace
 					sc.sym[name] = &symbol{kind: pkgSym, typ: &itype{cat: binPkgT}, path: ipath}
 				}
-			} else {
-				// TODO: make sure we do not import a src package more than once
-				err = interp.importSrcFile(rpath, ipath, name)
+			} else if err = interp.importSrc(rpath, ipath, name); err == nil {
 				sc.types = interp.universe.types
-				sc.sym[name] = &symbol{kind: pkgSym, typ: &itype{cat: srcPkgT}, path: ipath}
+				switch name {
+				case "_": // no import of symbols
+				case ".": // import symbols in current namespace
+					for k, v := range interp.srcPkg[ipath] {
+						if canExport(k) {
+							sc.sym[k] = v
+						}
+					}
+				default: // import symbols in package namespace
+					sc.sym[name] = &symbol{kind: pkgSym, typ: &itype{cat: srcPkgT}, path: ipath}
+				}
 			}
 
 		case typeSpec:

interp/interp.go

@@ -54,9 +54,12 @@ type frame struct {
 	recovered interface{}       // to handle panic recover
 }
 
-// Exports stores the map of external values per package
+// Exports stores the map of binary packages per package path
 type Exports map[string]map[string]reflect.Value
 
+// imports stores the map of source packages per package path
+type imports map[string]map[string]*symbol
+
 // opt stores interpreter options
 type opt struct {
 	astDot  bool          // display AST graph (debug)
@@ -74,7 +77,8 @@ type Interpreter struct {
 	fset     *token.FileSet    // fileset to locate node in source code
 	universe *scope            // interpreter global level scope
 	scopes   map[string]*scope // package level scopes, indexed by package name
-	binPkg   Exports           // runtime binary values used in interpreter
+	binPkg   Exports           // binary packages used in interpreter, indexed by path
+	srcPkg   imports           // source packages used in interpreter, indexed by path
 }
 
 const (
@@ -127,11 +131,12 @@ type Options struct {
 func New(options Options) *Interpreter {
 	i := Interpreter{
 		opt:      opt{context: build.Default},
+		frame:    &frame{data: []reflect.Value{}},
 		fset:     token.NewFileSet(),
 		universe: initUniverse(),
 		scopes:   map[string]*scope{},
 		binPkg:   Exports{"": map[string]reflect.Value{"_error": reflect.ValueOf((*_error)(nil))}},
-		frame:    &frame{data: []reflect.Value{}},
+		srcPkg:   imports{},
 	}
 
 	i.opt.context.GOPATH = options.GoPath

interp/interp_consistent_test.go

@@ -1,6 +1,7 @@
 package interp_test
 
 import (
+	"go/build"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -35,7 +36,6 @@ func TestInterpConsistencyBuild(t *testing.T) {
 			file.Name() == "export1.go" || // non-main package
 			file.Name() == "export0.go" || // non-main package
 			file.Name() == "io0.go" || // use random number
-			file.Name() == "import4.go" || // not compatible with go1.13
 			file.Name() == "op1.go" || // expect error
 			file.Name() == "bltn0.go" || // expect error
 			file.Name() == "method16.go" || // private struct field
@@ -79,7 +79,7 @@ func TestInterpConsistencyBuild(t *testing.T) {
 			r, w, _ := os.Pipe()
 			os.Stdout = w
 
-			i := interp.New(interp.Options{})
+			i := interp.New(interp.Options{GoPath: build.Default.GOPATH})
 			i.Name = filePath
 			i.Use(stdlib.Symbols)
 			i.Use(interp.Symbols)
@@ -179,7 +179,7 @@ func TestInterpErrorConsistency(t *testing.T) {
 				t.Fatal(err)
 			}
 
-			i := interp.New(interp.Options{})
+			i := interp.New(interp.Options{GoPath: build.Default.GOPATH})
 			i.Name = filePath
 			i.Use(stdlib.Symbols)
 

interp/interp_file_test.go

@@ -1,6 +1,7 @@
 package interp_test
 
 import (
+	"go/build"
 	"go/parser"
 	"go/token"
 	"io/ioutil"
@@ -51,7 +52,7 @@ func runCheck(t *testing.T, p string) {
 	r, w, _ := os.Pipe()
 	os.Stdout = w
 
-	i := interp.New(interp.Options{})
+	i := interp.New(interp.Options{GoPath: build.Default.GOPATH})
 	i.Name = p
 	i.Use(interp.Symbols)
 	i.Use(stdlib.Symbols)

interp/src.go

@@ -8,10 +8,14 @@ import (
 	"strings"
 )
 
-func (interp *Interpreter) importSrcFile(rPath, path, alias string) error {
+func (interp *Interpreter) importSrc(rPath, path, alias string) error {
 	var dir string
 	var err error
 
+	if interp.srcPkg[path] != nil {
+		return nil
+	}
+
 	// For relative import paths in the form "./xxx" or "../xxx", the initial
 	// base path is the directory of the interpreter input file, or "." if no file
 	// was provided.
@@ -92,6 +96,10 @@ func (interp *Interpreter) importSrcFile(rPath, path, alias string) error {
 		initNodes = append(initNodes, nodes...)
 	}
 
+	// Register source package in the interpreter. The package contains only
+	// the global symbols in the package scope.
+	interp.srcPkg[path] = interp.scopes[pkgName].sym
+
 	// Rename imported pkgName to alias if they are different
 	if pkgName != alias {
 		interp.scopes[alias] = interp.scopes[pkgName]

interp/type.go

@@ -383,7 +383,7 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 				if v, ok := pkg[name]; ok {
 					t.cat = valueT
 					t.rtype = v.Type()
-					if isBinType(v) {
+					if isBinType(v) { // a bin type is encoded as a pointer on nil value
 						t.rtype = t.rtype.Elem()
 					}
 				} else {
@@ -391,9 +391,9 @@ func nodeType(interp *Interpreter, sc *scope, n *node) (*itype, error) {
 				}
 
 			case srcPkgT:
-				spkg := interp.scopes[pkg]
-				if st, ok := spkg.sym[name]; ok {
-					t = st.typ
+				pkg := interp.srcPkg[sym.path]
+				if s, ok := pkg[name]; ok {
+					t = s.typ
 				} else {
 					t.incomplete = true
 				}