Golang Object.Pos方法代码示例

//getFullName is returning unique name of obj.
func getFullName(obj types.Object, ctx *getDefinitionsContext, isType bool) string {
	if obj == nil {
		return ""
	}
	if isType {
		return obj.Type().String()
	}

	result := ""

	switch obj.(type) {
	case *types.Func:
		f := obj.(*types.Func)
		r := strings.NewReplacer("(", "", "*", "", ")", "")
		result = r.Replace(f.FullName())
	default:
		if obj.Pkg() != nil {
			result += obj.Pkg().Path()
			result += "."
		}

		if packageName, ok := ctx.structs[posToStr(ctx.fset, obj.Pos())]; ok {
			result += packageName
			result += "."
		}
		result += obj.Name()
	}

	return result
}

func (p *exporter) fileLine(obj types.Object) (file string, line int) {
	if p.fset != nil {
		pos := p.fset.Position(obj.Pos())
		file = pos.Filename
		line = pos.Line
	}
	return
}

func (v *visitor) decl(obj types.Object) {
	key := getKey(obj)
	if _, ok := v.uses[key]; !ok {
		v.uses[key] = 0
	}
	if _, ok := v.positions[key]; !ok {
		v.positions[key] = v.prog.Fset.Position(obj.Pos())
	}
}

// memberFromObject populates package pkg with a member for the
// typechecker object obj.
//
// For objects from Go source code, syntax is the associated syntax
// tree (for funcs and vars only); it will be used during the build
// phase.
//
func memberFromObject(pkg *Package, obj types.Object, syntax ast.Node) {
	name := obj.Name()
	switch obj := obj.(type) {
	case *types.TypeName:
		pkg.Members[name] = &Type{
			object: obj,
			pkg:    pkg,
		}

	case *types.Const:
		c := &NamedConst{
			object: obj,
			Value:  NewConst(obj.Val(), obj.Type()),
			pkg:    pkg,
		}
		pkg.values[obj] = c.Value
		pkg.Members[name] = c

	case *types.Var:
		g := &Global{
			Pkg:    pkg,
			name:   name,
			object: obj,
			typ:    types.NewPointer(obj.Type()), // address
			pos:    obj.Pos(),
		}
		pkg.values[obj] = g
		pkg.Members[name] = g

	case *types.Func:
		sig := obj.Type().(*types.Signature)
		if sig.Recv() == nil && name == "init" {
			pkg.ninit++
			name = fmt.Sprintf("init#%d", pkg.ninit)
		}
		fn := &Function{
			name:      name,
			object:    obj,
			Signature: sig,
			syntax:    syntax,
			pos:       obj.Pos(),
			Pkg:       pkg,
			Prog:      pkg.Prog,
		}
		if syntax == nil {
			fn.Synthetic = "loaded from gc object file"
		}

		pkg.values[obj] = fn
		if sig.Recv() == nil {
			pkg.Members[name] = fn // package-level function
		}

	default: // (incl. *types.Package)
		panic("unexpected Object type: " + obj.String())
	}
}

func (f *Function) addParamObj(obj types.Object) *Parameter {
	name := obj.Name()
	if name == "" {
		name = fmt.Sprintf("arg%d", len(f.Params))
	}
	param := f.addParam(name, obj.Type(), obj.Pos())
	param.object = obj
	return param
}

// addSpilledParam declares a parameter that is pre-spilled to the
// stack; the function body will load/store the spilled location.
// Subsequent lifting will eliminate spills where possible.
//
func (f *Function) addSpilledParam(obj types.Object) {
	param := f.addParamObj(obj)
	spill := &Alloc{Comment: obj.Name()}
	spill.setType(types.NewPointer(obj.Type()))
	spill.setPos(obj.Pos())
	f.objects[obj] = spill
	f.Locals = append(f.Locals, spill)
	f.emit(spill)
	f.emit(&Store{Addr: spill, Val: param})
}

func (r *renamer) checkExport(id *ast.Ident, pkg *types.Package, from types.Object) bool {
	// Reject cross-package references if r.to is unexported.
	// (Such references may be qualified identifiers or field/method
	// selections.)
	if !ast.IsExported(r.to) && pkg != from.Pkg() {
		r.errorf(from.Pos(),
			"renaming this %s %q to %q would make it unexported",
			objectKind(from), from.Name(), r.to)
		r.errorf(id.Pos(), "\tbreaking references from packages such as %q",
			pkg.Path())
		return false
	}
	return true
}

func printTargetObj(obj types.Object) {
	if obj != nil && obj.Pos() != token.NoPos {
		fmt.Println(posPrinter{obj})
		return
	}
	if *godef != "" {
		cmd := exec.Command(*godef, os.Args[1:]...)
		cmd.Stdin = bytes.NewReader(fileBody)
		b, err := cmd.Output()
		if err != nil {
			fail()
		}
		os.Stdout.Write(b)
		return
	}
	fail()
}

func (r *renamer) checkInLocalScope(from types.Object) {
	info := r.packages[from.Pkg()]

	// Is this object an implicit local var for a type switch?
	// Each case has its own var, whose position is the decl of y,
	// but Ident in that decl does not appear in the Uses map.
	//
	//   switch y := x.(type) {	 // Defs[Ident(y)] is undefined
	//   case int:    print(y)       // Implicits[CaseClause(int)]    = Var(y_int)
	//   case string: print(y)       // Implicits[CaseClause(string)] = Var(y_string)
	//   }
	//
	var isCaseVar bool
	for syntax, obj := range info.Implicits {
		if _, ok := syntax.(*ast.CaseClause); ok && obj.Pos() == from.Pos() {
			isCaseVar = true
			r.check(obj)
		}
	}

	r.checkInLexicalScope(from, info)

	// Finally, if this was a type switch, change the variable y.
	if isCaseVar {
		_, path, _ := r.iprog.PathEnclosingInterval(from.Pos(), from.Pos())
		path[0].(*ast.Ident).Name = r.to // path is [Ident AssignStmt TypeSwitchStmt...]
	}
}

// checkInPackageBlock performs safety checks for renames of
// func/var/const/type objects in the package block.
func (r *renamer) checkInPackageBlock(from types.Object) {
	// Check that there are no references to the name from another
	// package if the renaming would make it unexported.
	if ast.IsExported(from.Name()) && !ast.IsExported(r.to) {
		for pkg, info := range r.packages {
			if pkg == from.Pkg() {
				continue
			}
			if id := someUse(info, from); id != nil &&
				!r.checkExport(id, pkg, from) {
				break
			}
		}
	}

	info := r.packages[from.Pkg()]

	// Check that in the package block, "init" is a function, and never referenced.
	if r.to == "init" {
		kind := objectKind(from)
		if kind == "func" {
			// Reject if intra-package references to it exist.
			for id, obj := range info.Uses {
				if obj == from {
					r.errorf(from.Pos(),
						"renaming this func %q to %q would make it a package initializer",
						from.Name(), r.to)
					r.errorf(id.Pos(), "\tbut references to it exist")
					break
				}
			}
		} else {
			r.errorf(from.Pos(), "you cannot have a %s at package level named %q",
				kind, r.to)
		}
	}

	// Check for conflicts between package block and all file blocks.
	for _, f := range info.Files {
		fileScope := info.Info.Scopes[f]
		b, prev := fileScope.LookupParent(r.to, token.NoPos)
		if b == fileScope {
			r.errorf(from.Pos(), "renaming this %s %q to %q would conflict",
				objectKind(from), from.Name(), r.to)
			r.errorf(prev.Pos(), "\twith this %s",
				objectKind(prev))
			return // since checkInPackageBlock would report redundant errors
		}
	}

	// Check for conflicts in lexical scope.
	if from.Exported() {
		for _, info := range r.packages {
			r.checkInLexicalScope(from, info)
		}
	} else {
		r.checkInLexicalScope(from, info)
	}
}

// check performs safety checks of the renaming of the 'from' object to r.to.
func (r *renamer) check(from types.Object) {
	if r.objsToUpdate[from] {
		return
	}
	r.objsToUpdate[from] = true

	// NB: order of conditions is important.
	if from_, ok := from.(*types.PkgName); ok {
		r.checkInFileBlock(from_)
	} else if from_, ok := from.(*types.Label); ok {
		r.checkLabel(from_)
	} else if isPackageLevel(from) {
		r.checkInPackageBlock(from)
	} else if v, ok := from.(*types.Var); ok && v.IsField() {
		r.checkStructField(v)
	} else if f, ok := from.(*types.Func); ok && recv(f) != nil {
		r.checkMethod(f)
	} else if isLocal(from) {
		r.checkInLocalScope(from)
	} else {
		r.errorf(from.Pos(), "unexpected %s object %q (please report a bug)\n",
			objectKind(from), from)
	}
}

func saveRecent(ident *ast.Ident, obj types.Object) {
	if *cacheFile == "" {
		return
	}
	if obj == nil || obj.Pos() == token.NoPos {
		return
	}

	if fset.Position(ident.Pos()).Filename == fset.Position(obj.Pos()).Filename {
		lg("same file")
		return
	}

	k := posPrinter{ident}.String()

	sha := fileSHA(fset.Position(obj.Pos()).Filename)
	if sha == "" {
		return
	}

	now := time.Now()
	ent := &objectEntry{
		FromSHA1: fileSHA1,
		ToPos:    posPrinter{obj}.String(),
		ToSHA1:   sha,
		Created:  now.UnixNano(),
	}
	lg("new recent entry %s => %+v", k, ent)

	if recents == nil {
		recents = &recentObjects{entries: make(map[string]*objectEntry)}
	}
	recents.entries[k] = ent

	expire := now.Add(-24 * time.Hour).UnixNano()
	for k, ent := range recents.entries {
		if ent.bad || ent.Created < expire {
			delete(recents.entries, k)
		}
	}

	b, err := json.MarshalIndent(recents.entries, "", "  ")
	if err != nil {
		lg("marshal recents err=%v", err)
		return
	}
	if err = ioutil.WriteFile(*cacheFile, b, 0600); err != nil {
		lg("write recents err=%v", err)
	}
}

func (r *renamer) selectionConflict(from types.Object, delta int, syntax *ast.SelectorExpr, obj types.Object) {
	r.errorf(from.Pos(), "renaming this %s %q to %q",
		objectKind(from), from.Name(), r.to)

	switch {
	case delta < 0:
		// analogous to sub-block conflict
		r.errorf(syntax.Sel.Pos(),
			"\twould change the referent of this selection")
		r.errorf(obj.Pos(), "\tof this %s", objectKind(obj))
	case delta == 0:
		// analogous to same-block conflict
		r.errorf(syntax.Sel.Pos(),
			"\twould make this reference ambiguous")
		r.errorf(obj.Pos(), "\twith this %s", objectKind(obj))
	case delta > 0:
		// analogous to super-block conflict
		r.errorf(syntax.Sel.Pos(),
			"\twould shadow this selection")
		r.errorf(obj.Pos(), "\tof the %s declared here",
			objectKind(obj))
	}
}

func fileLine(fset *token.FileSet, obj types.Object) string {
	posn := fset.Position(obj.Pos())
	return fmt.Sprintf("%s:%d", posn.Filename, posn.Line)
}

func formatNode(n ast.Node, obj types.Object, prog *loader.Program) string {
	var nc ast.Node
	// Render a copy of the node with no documentation.
	// We emit the documentation ourself.
	switch n := n.(type) {
	case *ast.FuncDecl:
		cp := *n
		cp.Doc = nil
		// Don't print the whole function body
		cp.Body = nil
		nc = &cp
	case *ast.GenDecl:
		cp := *n
		cp.Doc = nil
		if len(n.Specs) > 0 {
			// Only print this one type, not all the types in the
			// gendecl
			switch n.Specs[0].(type) {
			case *ast.TypeSpec:
				spec := findTypeSpec(n, obj.Pos())
				if spec != nil {
					specCp := *spec
					if *showUnexportedFields == false {
						trimUnexportedElems(&specCp)
					}
					specCp.Doc = nil
					cp.Specs = []ast.Spec{&specCp}
				}
				cp.Lparen = 0
				cp.Rparen = 0
			case *ast.ValueSpec:
				spec := findVarSpec(n, obj.Pos())
				if spec != nil {
					specCp := *spec
					specCp.Doc = nil
					cp.Specs = []ast.Spec{&specCp}
				}
				cp.Lparen = 0
				cp.Rparen = 0
			}
		}
		nc = &cp
	case *ast.Field:
		// Not supported by go/printer

		// TODO(dominikh): Methods in interfaces are syntactically
		// represented as fields. Using types.Object.String for those
		// causes them to look different from real functions.
		// go/printer doesn't include the import paths in names, while
		// Object.String does. Fix that.

		return obj.String()
	default:
		return obj.String()
	}

	buf := &bytes.Buffer{}
	cfg := printer.Config{Mode: printer.UseSpaces | printer.TabIndent, Tabwidth: 8}
	err := cfg.Fprint(buf, prog.Fset, nc)
	if err != nil {
		return obj.String()
	}
	return buf.String()
}