Golang Object.Parent方法代码示例

// isLocal reports whether obj is local to some function.
// Precondition: not a struct field or interface method.
func isLocal(obj types.Object) bool {
	// [... 5=stmt 4=func 3=file 2=pkg 1=universe]
	var depth int
	for scope := obj.Parent(); scope != nil; scope = scope.Parent() {
		depth++
	}
	return depth >= 4
}

func isExported(obj types.Object) bool {
	// https://golang.org/ref/spec#Exported_identifiers
	// An identifier is exported if both:
	// the first character of the identifier's name is a Unicode upper case letter (Unicode class "Lu"); and
	// the identifier is declared in the package block or it is a field name or method name.
	// All other identifiers are not exported.

	if !obj.Exported() {
		// does not start with an upper case letter
		return false
	}

	if v, ok := obj.(*types.Var); ok && v.IsField() {
		// is a field name
		return true
	}
	if sig, ok := obj.Type().(*types.Signature); ok && sig.Recv() != nil {
		// is a method name
		return true
	}
	// is declared in the package block
	return obj.Parent() == obj.Pkg().Scope()
}

func (g *Grapher) path(obj types.Object) (path []string) {
	if path, present := g.paths[obj]; present {
		return path
	}

	var scope *types.Scope
	pkgInfo, astPath, _ := g.program.PathEnclosingInterval(obj.Pos(), obj.Pos())
	if astPath != nil {
		for _, node := range astPath {
			if s, hasScope := pkgInfo.Scopes[node]; hasScope {
				scope = s
			}
		}
	}
	if scope == nil {
		scope = obj.Parent()
	}

	if scope == nil {
		// TODO(sqs): make this actually handle cases like the one described in
		// https://github.com/sourcegraph/sourcegraph.com/issues/218
		log.Printf("Warning: no scope for object %s at pos %s", obj.String(), g.program.Fset.Position(obj.Pos()))
		return nil
	}

	prefix, hasPath := g.scopePaths[scope]
	if !hasPath {
		panic("no scope path for scope " + scope.String())
	}
	path = append([]string{}, prefix...)
	p := g.program.Fset.Position(obj.Pos())
	path = append(path, obj.Name()+uniqID(p))
	return path

	panic("no scope node for object " + obj.String())
}

func isPkgLevel(o types.Object) bool {
	return o.Parent() != nil && o.Parent().Parent() == types.Universe
}

// getDoc returns the doc string associated with types.Object
// parent is the name of the containing scope ("" for global scope)
func (p *Package) getDoc(parent string, o types.Object) string {
	n := o.Name()
	switch o.(type) {
	case *types.Const:
		for _, c := range p.doc.Consts {
			for _, cn := range c.Names {
				if n == cn {
					return c.Doc
				}
			}
		}

	case *types.Var:
		for _, v := range p.doc.Vars {
			for _, vn := range v.Names {
				if n == vn {
					return v.Doc
				}
			}
		}

	case *types.Func:
		doc := func() string {
			if o.Parent() == nil || (o.Parent() != nil && parent != "") {
				for _, typ := range p.doc.Types {
					if typ.Name != parent {
						continue
					}
					if o.Parent() == nil {
						for _, m := range typ.Methods {
							if m.Name == n {
								return m.Doc
							}
						}
					} else {
						for _, m := range typ.Funcs {
							if m.Name == n {
								return m.Doc
							}
						}
					}
				}
			} else {
				for _, f := range p.doc.Funcs {
					if n == f.Name {
						return f.Doc
					}
				}
			}
			return ""
		}()

		sig := o.Type().(*types.Signature)

		parseFn := func(tup *types.Tuple) []string {
			params := []string{}
			if tup == nil {
				return params
			}
			for i := 0; i < tup.Len(); i++ {
				paramVar := tup.At(i)
				paramType := p.syms.symtype(paramVar.Type()).pysig
				if paramVar.Name() != "" {
					paramType = fmt.Sprintf("%s %s", paramType, paramVar.Name())
				}
				params = append(params, paramType)
			}
			return params
		}

		params := parseFn(sig.Params())
		results := parseFn(sig.Results())

		paramString := strings.Join(params, ", ")
		resultString := strings.Join(results, ", ")

		//FIXME(sbinet): add receiver for methods?
		docSig := fmt.Sprintf("%s(%s) %s", o.Name(), paramString, resultString)

		if doc != "" {
			doc = fmt.Sprintf("%s\n\n%s", docSig, doc)
		} else {
			doc = docSig
		}
		return doc

	case *types.TypeName:
		for _, t := range p.doc.Types {
			if n == t.Name {
				return t.Doc
			}
		}

	default:
		// TODO(sbinet)
		panic(fmt.Errorf("not yet supported: %v (%T)", o, o))
	}

//.........这里部分代码省略.........

// checkInLexicalScope performs safety checks that a renaming does not
// change the lexical reference structure of the specified package.
//
// For objects in lexical scope, there are three kinds of conflicts:
// same-, sub-, and super-block conflicts.  We will illustrate all three
// using this example:
//
//	var x int
//	var z int
//
//	func f(y int) {
//		print(x)
//		print(y)
//	}
//
// Renaming x to z encounters a SAME-BLOCK CONFLICT, because an object
// with the new name already exists, defined in the same lexical block
// as the old object.
//
// Renaming x to y encounters a SUB-BLOCK CONFLICT, because there exists
// a reference to x from within (what would become) a hole in its scope.
// The definition of y in an (inner) sub-block would cast a shadow in
// the scope of the renamed variable.
//
// Renaming y to x encounters a SUPER-BLOCK CONFLICT.  This is the
// converse situation: there is an existing definition of the new name
// (x) in an (enclosing) super-block, and the renaming would create a
// hole in its scope, within which there exist references to it.  The
// new name casts a shadow in scope of the existing definition of x in
// the super-block.
//
// Removing the old name (and all references to it) is always safe, and
// requires no checks.
//
func (r *renamer) checkInLexicalScope(from types.Object, info *loader.PackageInfo) {
	b := from.Parent() // the block defining the 'from' object
	if b != nil {
		toBlock, to := b.LookupParent(r.to, from.Parent().End())
		if toBlock == b {
			// same-block conflict
			r.errorf(from.Pos(), "renaming this %s %q to %q",
				objectKind(from), from.Name(), r.to)
			r.errorf(to.Pos(), "\tconflicts with %s in same block",
				objectKind(to))
			return
		} else if toBlock != nil {
			// Check for super-block conflict.
			// The name r.to is defined in a superblock.
			// Is that name referenced from within this block?
			forEachLexicalRef(info, to, func(id *ast.Ident, block *types.Scope) bool {
				_, obj := lexicalLookup(block, from.Name(), id.Pos())
				if obj == from {
					// super-block conflict
					r.errorf(from.Pos(), "renaming this %s %q to %q",
						objectKind(from), from.Name(), r.to)
					r.errorf(id.Pos(), "\twould shadow this reference")
					r.errorf(to.Pos(), "\tto the %s declared here",
						objectKind(to))
					return false // stop
				}
				return true
			})
		}
	}

	// Check for sub-block conflict.
	// Is there an intervening definition of r.to between
	// the block defining 'from' and some reference to it?
	forEachLexicalRef(info, from, func(id *ast.Ident, block *types.Scope) bool {
		// Find the block that defines the found reference.
		// It may be an ancestor.
		fromBlock, _ := lexicalLookup(block, from.Name(), id.Pos())

		// See what r.to would resolve to in the same scope.
		toBlock, to := lexicalLookup(block, r.to, id.Pos())
		if to != nil {
			// sub-block conflict
			if deeper(toBlock, fromBlock) {
				r.errorf(from.Pos(), "renaming this %s %q to %q",
					objectKind(from), from.Name(), r.to)
				r.errorf(id.Pos(), "\twould cause this reference to become shadowed")
				r.errorf(to.Pos(), "\tby this intervening %s definition",
					objectKind(to))
				return false // stop
			}
		}
		return true
	})

	// Renaming a type that is used as an embedded field
	// requires renaming the field too. e.g.
	// 	type T int // if we rename this to U..
	// 	var s struct {T}
	// 	print(s.T) // ...this must change too
	if _, ok := from.(*types.TypeName); ok {
		for id, obj := range info.Uses {
			if obj == from {
				if field := info.Defs[id]; field != nil {
					r.check(field)
				}
//.........这里部分代码省略.........