initial rework of xgotext

cli/xgotext/parser/golang.go

@@ -0,0 +1,255 @@
+package parser
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+	"go/types"
+	"log"
+	"path/filepath"
+	"strconv"
+
+	"golang.org/x/tools/go/packages"
+)
+
+// GetterDef describes a getter
+type GetterDef struct {
+	Id      int
+	Plural  int
+	Context int
+	Domain  int
+}
+
+// maxArgIndex returns the largest argument index
+func (d *GetterDef) maxArgIndex() int {
+	m := d.Id
+	if d.Plural > m {
+		m = d.Plural
+	}
+	if d.Context > m {
+		m = d.Context
+	}
+	if d.Domain > m {
+		m = d.Domain
+	}
+	return m
+}
+
+// list of supported getter
+var gotextGetter = map[string]GetterDef{
+	"Get":    {0, -1, -1, -1},
+	"GetN":   {0, 1, -1, -1},
+	"GetD":   {1, -1, -1, 0},
+	"GetND":  {1, 2, -1, 0},
+	"GetC":   {0, -1, 1, -1},
+	"GetNC":  {0, 1, 3, -1},
+	"GetDC":  {1, -1, 2, 0},
+	"GetNDC": {1, 2, 4, 0},
+}
+
+// register go parser
+func init() {
+	AddParser(goParser)
+}
+
+// parse go package
+func goParser(dirPath, basePath string, data DomainMap) error {
+	fileSet := token.NewFileSet()
+
+	conf := packages.Config{
+		Mode: packages.NeedName |
+			packages.NeedFiles |
+			packages.NeedSyntax |
+			packages.NeedTypes |
+			packages.NeedTypesInfo,
+		Fset: fileSet,
+		Dir:  basePath,
+	}
+
+	// load package from path
+	pkgs, err := packages.Load(&packages.Config{
+		Mode: conf.Mode,
+		Fset: fileSet,
+		Dir:  dirPath,
+	})
+	if err != nil || len(pkgs) == 0 {
+		// not a go package
+		return nil
+	}
+
+	// handle each file
+	for _, node := range pkgs[0].Syntax {
+		file := GoFile{
+			pkgConf:  &conf,
+			filePath: fileSet.Position(node.Package).Filename,
+			basePath: basePath,
+			data:     data,
+			fileSet:  fileSet,
+
+			importedPackages: map[string]*packages.Package{
+				pkgs[0].Name: pkgs[0],
+			},
+		}
+
+		ast.Inspect(node, file.inspectFile)
+	}
+	return nil
+}
+
+// GoFile handles the parsing of one go file
+type GoFile struct {
+	filePath string
+	basePath string
+	data     DomainMap
+
+	fileSet *token.FileSet
+	pkgConf *packages.Config
+
+	importedPackages map[string]*packages.Package
+}
+
+// getPackage loads module by name
+func (g *GoFile) getPackage(name string) (*packages.Package, error) {
+	pkgs, err := packages.Load(g.pkgConf, name)
+	if err != nil {
+		return nil, err
+	}
+	if len(pkgs) == 0 {
+		return nil, nil
+	}
+	return pkgs[0], nil
+}
+
+// getType from ident object
+func (g *GoFile) getType(ident *ast.Ident) types.Object {
+	for _, pkg := range g.importedPackages {
+		if obj, ok := pkg.TypesInfo.Uses[ident]; ok {
+			return obj
+		}
+	}
+	return nil
+}
+
+func (g *GoFile) inspectFile(n ast.Node) bool {
+	switch x := n.(type) {
+	// get names of imported packages
+	case *ast.ImportSpec:
+		packageName, _ := strconv.Unquote(x.Path.Value)
+
+		pkg, err := g.getPackage(packageName)
+		if err != nil {
+			log.Printf("failed to load package %s: %s", packageName, err)
+		} else {
+			if x.Name == nil {
+				g.importedPackages[pkg.Name] = pkg
+			} else {
+				g.importedPackages[x.Name.Name] = pkg
+			}
+		}
+
+	// check each function call
+	case *ast.CallExpr:
+		g.inspectCallExpr(x)
+
+	default:
+		print()
+	}
+
+	return true
+}
+
+// checkType for gotext object
+func (g *GoFile) checkType(rawType types.Type) bool {
+	switch t := rawType.(type) {
+	case *types.Pointer:
+		return g.checkType(t.Elem())
+
+	case *types.Named:
+		if t.Obj().Pkg().Path() != "github.com/leonelquinteros/gotext" {
+			return false
+		}
+	default:
+		return false
+	}
+	return true
+}
+
+func (g *GoFile) inspectCallExpr(n *ast.CallExpr) {
+	// must be a selector expression otherwise it is a local function call
+	expr, ok := n.Fun.(*ast.SelectorExpr)
+	if !ok {
+		return
+	}
+
+	switch e := expr.X.(type) {
+	// direct call
+	case *ast.Ident:
+		// object is a package if the Obj is not set
+		if e.Obj == nil {
+			pkg, ok := g.importedPackages[e.Name]
+			if !ok || pkg.PkgPath != "github.com/leonelquinteros/gotext" {
+				return
+			}
+
+		} else {
+			// validate type of object
+			if !g.checkType(g.getType(e).Type()) {
+				return
+			}
+		}
+
+	// call to attribute
+	case *ast.SelectorExpr:
+		// validate type of object
+		if !g.checkType(g.getType(e.Sel).Type()) {
+			return
+		}
+
+	default:
+		return
+	}
+
+	// convert args
+	args := make([]*ast.BasicLit, len(n.Args))
+	for idx, arg := range n.Args {
+		args[idx], _ = arg.(*ast.BasicLit)
+	}
+
+	// get position
+	path, _ := filepath.Rel(g.basePath, g.filePath)
+	position := fmt.Sprintf("%s:%d", path, g.fileSet.Position(n.Lparen).Line)
+
+	// handle getters
+	if def, ok := gotextGetter[expr.Sel.String()]; ok {
+		g.parseGetter(def, args, position)
+		return
+	}
+}
+
+func (g *GoFile) parseGetter(def GetterDef, args []*ast.BasicLit, pos string) {
+	// check if enough arguments are given
+	if len(args) < def.maxArgIndex() {
+		return
+	}
+
+	// get domain
+	var domain string
+	if def.Domain == -1 {
+		domain = "default" // TODO
+	} else {
+		domain, _ = strconv.Unquote(args[def.Domain].Value)
+	}
+
+	trans := Translation{
+		MsgId:           args[def.Id].Value,
+		SourceLocations: []string{pos},
+	}
+	if def.Plural > 0 {
+		trans.MsgIdPlural = args[def.Plural].Value
+	}
+	if def.Context > 0 {
+		trans.Context = args[def.Context].Value
+	}
+
+	g.data.AddTranslation(domain, &trans)
+}