Use x/tools/go/packages to significantly improve speed of extract code generation

extract/extract.go

@@ -23,6 +23,8 @@ import (
 	"strconv"
 	"strings"
 	"text/template"
+
+	"golang.org/x/tools/go/packages"
 )
 
 const model = `// Code generated by 'yaegi extract {{.ImportPath}}'. DO NOT EDIT.
@@ -447,16 +449,44 @@ func (e *Extractor) Extract(pkgIdent, importPath string, rw io.Writer) (string,
 		return "", err
 	}
 
-	pkg, err := importer.ForCompiler(token.NewFileSet(), "source", nil).Import(pkgIdent)
-	if err != nil {
-		return "", err
+	var pkg *types.Package
+	isRelative := strings.HasPrefix(pkgIdent, ".")
+	// If we are relative with a manual import path, we cannot use modules
+	// and must fall back on the standard go/importer loader.
+	if isRelative && importPath != "" {
+		pkg, err = importer.ForCompiler(token.NewFileSet(), "source", nil).Import(pkgIdent)
+		if err != nil {
+			return "", err
+		}
+	} else {
+		// Otherwise, we can use the much faster x/tools/go/packages loader.
+		if isRelative {
+			// We must be in the location of the module for the loader to work correctly.
+			err := os.Chdir(pkgIdent)
+			if err != nil {
+				return "", err
+			}
+			// Our path must point back to ourself here.
+			pkgIdent = filepath.Join("..", filepath.Base(pkgIdent))
+		}
+		pkgs, err := packages.Load(&packages.Config{Mode: packages.NeedTypes}, pkgIdent)
+		if err != nil {
+			return "", err
+		}
+		if len(pkgs) != 1 {
+			return "", fmt.Errorf("expected one package, got %d", len(pkgs))
+		}
+		ppkg := pkgs[0]
+		if len(ppkg.Errors) > 0 {
+			return "", ppkg.Errors[0]
+		}
+		pkg = ppkg.Types
 	}
 
 	content, err := e.genContent(ipp, pkg)
 	if err != nil {
 		return "", err
 	}
-
 	if _, err := rw.Write(content); err != nil {
 		return "", err
 	}

go.mod

@@ -1,3 +1,10 @@
 module github.com/traefik/yaegi
 
 go 1.21
+
+require golang.org/x/tools v0.22.0
+
+require (
+	golang.org/x/mod v0.18.0 // indirect
+	golang.org/x/sync v0.7.0 // indirect
+)

go.sum

@@ -0,0 +1,6 @@
+golang.org/x/mod v0.18.0 h1:5+9lSbEzPSdWkH32vYPBwEpX8KwDbM52Ud9xBUvNlb0=
+golang.org/x/mod v0.18.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
+golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
+golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/tools v0.22.0 h1:gqSGLZqv+AI9lIQzniJ0nZDRG5GBPsSi+DRNHWNz6yA=
+golang.org/x/tools v0.22.0/go.mod h1:aCwcsjqvq7Yqt6TNyX7QMU2enbQ/Gt0bo6krSeEri+c=