Golang ast.NewIdent函数代码示例

func ParseTry(fset *token.FileSet, f *ast.File) {
	blocks := FilterAst(f, func(n ast.Node) bool {
		return GetBlock(n) != nil
	})
	for tree := range blocks {
		parent := ParentFunc(tree)

		b := GetBlock(tree.Node)
		var block []ast.Stmt
		madeTry := false
		for _, v := range *b {
			if try := GetTryCall(v); try != nil {
				madeTry = true
				block = AppendTryBlock(block, v, BuildTryBlock(parent, try))
			} else {
				block = append(block, v)
			}
		}
		if madeTry {
			varErr := &ast.ValueSpec{nil, []*ast.Ident{ast.NewIdent("err")}, ast.NewIdent("error"), nil, nil}
			defineErr := &ast.GenDecl{nil, 0, token.VAR, 0, []ast.Spec{varErr, nil}, 0}
			stmt := []ast.Stmt{&ast.DeclStmt{defineErr}}
			block = append(stmt, block...)
		}
		*b = block
	}
	EnsureNoTry(f)
}

func insertIntVar(file *ast.File, name string, value int) {
	var before, after []ast.Decl

	if len(file.Decls) > 0 {
		hasImport := false
		if genDecl, ok := file.Decls[0].(*ast.GenDecl); ok {
			hasImport = genDecl.Tok == token.IMPORT
		}

		if hasImport {
			before, after = []ast.Decl{file.Decls[0]}, file.Decls[1:]
		} else {
			after = file.Decls
		}
	}

	file.Decls = append(before,
		&ast.GenDecl{
			Tok: token.VAR,
			Specs: []ast.Spec{
				&ast.ValueSpec{
					Names: []*ast.Ident{ast.NewIdent(name)},
					Type:  ast.NewIdent("int"),
					Values: []ast.Expr{
						&ast.BasicLit{
							Kind:  token.INT,
							Value: fmt.Sprintf("%d", value),
						},
					},
				},
			},
		},
	)
	file.Decls = append(file.Decls, after...)
}

func AppendTryBlock(block []ast.Stmt, node ast.Node, errBlock []ast.Stmt) []ast.Stmt {
	var try, call *ast.CallExpr
	var assign *ast.AssignStmt
	_err, _nil := ast.NewIdent("err"), ast.NewIdent("nil")
	// err != nil
	errNil := &ast.BinaryExpr{_err, 0, token.NEQ, _nil}
	// if errNil { stmt }
	ifBlock := &ast.IfStmt{0, nil, errNil, &ast.BlockStmt{0, errBlock, 0}, nil}

	switch n := node.(type) {
	case *ast.AssignStmt:
		assign = n
		try = n.Rhs[0].(*ast.CallExpr)
	case *ast.ExprStmt:
		try = n.X.(*ast.CallExpr)
	default:
		log.Fatalf("unhandled try() node type: %T\n", node)
	}
	if assign == nil {
		assign = &ast.AssignStmt{nil, 0, token.ASSIGN, nil}
	}
	call = StripTry(try)
	assign.Rhs = []ast.Expr{call}
	assign.Lhs = append(assign.Lhs, _err)

	block = append(block, assign)
	block = append(block, ifBlock)
	return block
}

func replaceStructLiteralWithIdentifier(statement ast.Node, n *ast.CompositeLit, name string) {
	ast.Inspect(statement, func(parentNode ast.Node) bool {
		switch parentNode := parentNode.(type) {
		case *ast.KeyValueExpr:
			if parentNode.Value == n {
				parentNode.Value = ast.NewIdent(name)
			}
		case *ast.CallExpr:
			for i, expr := range parentNode.Args {
				if expr == n {
					parentNode.Args[i] = ast.NewIdent(name)
				}
			}
		case *ast.AssignStmt:
			if parentNode.Rhs[0] == n {
				parentNode.Rhs[0] = ast.NewIdent(name)
			}
		case *ast.ReturnStmt:
			for i, expr := range parentNode.Results {
				if expr == n {
					parentNode.Results[i] = ast.NewIdent(name)
				}
			}
		case *ast.CompositeLit:
			for i, expr := range parentNode.Elts {
				if expr == n {
					parentNode.Elts[i] = ast.NewIdent(name)
				}
			}
		}

		return true
	})
}

func (t *GeneratorModel) resolveMutexType() *ast.SelectorExpr {
	alias := t.AddImport("sync", "sync")
	return &ast.SelectorExpr{
		X:   ast.NewIdent(alias),
		Sel: ast.NewIdent("RWMutex"),
	}
}

func insertHello(file *ast.File) {
	ast.Inspect(file, func(node ast.Node) bool {
		if ifStmt, ok := node.(*ast.IfStmt); ok {
			ifStmt.Body.List = append(
				[]ast.Stmt{
					&ast.ExprStmt{
						X: &ast.CallExpr{
							Fun: &ast.SelectorExpr{
								X:   ast.NewIdent("fmt"),
								Sel: ast.NewIdent("Printf"),
							},
							Args: []ast.Expr{
								&ast.BasicLit{
									Kind:  token.STRING,
									Value: "\"hello\"",
								},
							},
						},
					},
				},
				ifStmt.Body.List...,
			)
		}
		return true
	})
}

func (m *FileBuilder) Build() *ast.File {
	file := &ast.File{
		Name: ast.NewIdent(m.filePackageName),
	}

	if len(m.aliasToImport) > 0 {
		importDeclaration := &ast.GenDecl{
			Tok:    token.IMPORT,
			Lparen: token.Pos(1),
			Specs:  []ast.Spec{},
		}
		for alias, location := range m.aliasToImport {
			importDeclaration.Specs = append(importDeclaration.Specs, &ast.ImportSpec{
				Name: ast.NewIdent(alias),
				Path: &ast.BasicLit{
					Kind:  token.STRING,
					Value: fmt.Sprintf("\"%s\"", location),
				},
			})
		}
		file.Decls = append(file.Decls, importDeclaration)
	}

	for _, builder := range m.generalDeclarationBuilders {
		file.Decls = append(file.Decls, builder.Build())
	}

	return file
}

// playExampleFile takes a whole file example and synthesizes a new *ast.File
// such that the example is function main in package main.
func playExampleFile(file *ast.File) *ast.File {
	// Strip copyright comment if present.
	comments := file.Comments
	if len(comments) > 0 && strings.HasPrefix(comments[0].Text(), "Copyright") {
		comments = comments[1:]
	}

	// Copy declaration slice, rewriting the ExampleX function to main.
	var decls []ast.Decl
	for _, d := range file.Decls {
		if f, ok := d.(*ast.FuncDecl); ok && isTest(f.Name.Name, "Example") {
			// Copy the FuncDecl, as it may be used elsewhere.
			newF := *f
			newF.Name = ast.NewIdent("main")
			newF.Body, comments = stripOutputComment(f.Body, comments)
			d = &newF
		}
		decls = append(decls, d)
	}

	// Copy the File, as it may be used elsewhere.
	f := *file
	f.Name = ast.NewIdent("main")
	f.Decls = decls
	f.Comments = comments
	return &f
}

func (m *MethodBuilder) Build() ast.Decl {
	statements := make([]ast.Stmt, len(m.statementBuilders))
	for i, builder := range m.statementBuilders {
		statements[i] = builder.Build()
	}
	return &ast.FuncDecl{
		Recv: &ast.FieldList{
			List: []*ast.Field{
				{
					Names: []*ast.Ident{
						ast.NewIdent(m.receiverName),
					},
					Type: &ast.StarExpr{
						X: ast.NewIdent(m.receiverType),
					},
				},
			},
		},
		Name: ast.NewIdent(m.name),
		Type: m.funcType,
		Body: &ast.BlockStmt{
			List: statements,
		},
	}
}

func (gen CodeGenerator) methodCallCountGetter(method *ast.Field) *ast.FuncDecl {
	return &ast.FuncDecl{
		Name: ast.NewIdent(callCountMethodName(method)),
		Type: &ast.FuncType{
			Results: &ast.FieldList{List: []*ast.Field{
				&ast.Field{
					Type: ast.NewIdent("int"),
				},
			}},
		},
		Recv: gen.receiverFieldList(),
		Body: &ast.BlockStmt{List: []ast.Stmt{
			callMutex(method, "RLock"),
			deferMutex(method, "RUnlock"),

			&ast.ReturnStmt{
				Results: []ast.Expr{
					&ast.CallExpr{
						Fun: ast.NewIdent("len"),
						Args: []ast.Expr{
							&ast.SelectorExpr{
								X:   receiverIdent(),
								Sel: ast.NewIdent(callArgsFieldName(method)),
							},
						},
					},
				},
			},
		}},
	}
}

func hmacnew(f *ast.File) (fixed bool) {
	if !imports(f, "crypto/hmac") {
		return
	}

	walk(f, func(n interface{}) {
		ce, ok := n.(*ast.CallExpr)
		if !ok {
			return
		}

		var pkg string
		switch {
		case isPkgDot(ce.Fun, "hmac", "NewMD5"):
			pkg = "md5"
		case isPkgDot(ce.Fun, "hmac", "NewSHA1"):
			pkg = "sha1"
		case isPkgDot(ce.Fun, "hmac", "NewSHA256"):
			pkg = "sha256"
		default:
			return
		}

		addImport(f, "crypto/"+pkg)

		ce.Fun = ast.NewIdent("hmac.New")
		ce.Args = append([]ast.Expr{ast.NewIdent(pkg + ".New")}, ce.Args...)

		fixed = true
	})

	return
}

func makeLoop(node *parser.CallNode) *ast.CallExpr {
	returnIdent := generateIdent()
	loopIdent := generateIdent()

	fnBody := h.EmptyS()

	bindingsVector := node.Args[0].(*parser.VectorNode)

	addRecurLabelAndBindings(parser.NewIdentNode(loopIdent.String()), bindingsVector.Copy().(*parser.VectorNode), node.Args[1:])

	bindings := makeBindings(bindingsVector, token.DEFINE)
	returnIdentValueSpec := makeValueSpec(h.I(returnIdent), nil, anyType)
	returnIdentDecl := makeDeclStmt(makeGeneralDecl(token.VAR, []ast.Spec{returnIdentValueSpec}))

	fnBody = append(fnBody, bindings...)
	fnBody = append(fnBody, returnIdentDecl)

	init := makeAssignStmt(h.E(loopIdent), h.E(ast.NewIdent("true")), token.DEFINE)
	forBody := h.EmptyS()

	forBody = append(forBody, makeAssignStmt(h.E(loopIdent), h.E(ast.NewIdent("false")), token.ASSIGN))
	forBody = append(forBody, wrapExprsWithStmt(EvalExprs(node.Args[1:len(node.Args)-1]))...)
	forBody = append(forBody, makeAssignStmt(h.E(returnIdent), h.E(EvalExpr(node.Args[len(node.Args)-1])), token.ASSIGN))

	forStmt := makeForStmt(init, nil, loopIdent, makeBlockStmt(forBody))

	fnBody = append(fnBody, forStmt)
	fnBody = append(fnBody, makeReturnStmt(h.E(returnIdent)))

	results := makeFieldList([]*ast.Field{makeField(nil, anyType)})
	fnType := makeFuncType(results, nil)
	fn := makeFuncLit(fnType, makeBlockStmt(fnBody))

	return makeFuncCall(fn, h.EmptyE())
}

func (b *CountMethodBuilder) Build() ast.Decl {
	mutexLockBuilder := NewMutexActionBuilder()
	mutexLockBuilder.SetMutexFieldSelector(b.mutexFieldSelector)
	mutexLockBuilder.SetAction("RLock")

	mutexUnlockBuilder := NewMutexActionBuilder()
	mutexUnlockBuilder.SetMutexFieldSelector(b.mutexFieldSelector)
	mutexUnlockBuilder.SetAction("RUnlock")
	mutexUnlockBuilder.SetDeferred(true)

	b.methodBuilder.SetType(&ast.FuncType{
		Params: &ast.FieldList{},
		Results: &ast.FieldList{
			List: []*ast.Field{
				{
					Type: ast.NewIdent("int"),
				},
			},
		},
	})
	b.methodBuilder.AddStatementBuilder(mutexLockBuilder)
	b.methodBuilder.AddStatementBuilder(mutexUnlockBuilder)
	b.methodBuilder.AddStatementBuilder(StatementToBuilder(&ast.ReturnStmt{
		Results: []ast.Expr{
			&ast.CallExpr{
				Fun: ast.NewIdent("len"),
				Args: []ast.Expr{
					b.argsFieldSelector,
				},
			},
		},
	}))
	return b.methodBuilder.Build()
}

// We handle comparisons as a call to some go code, since you can only
// compare ints, floats, cmplx, and such, you know...
// We handle arithmetic operations as function calls, since all args are evaluated
func makeNAryCallableExpr(node *parser.CallNode) *ast.CallExpr {
	op := node.Callee.(*parser.IdentNode).Ident
	args := EvalExprs(node.Args)
	var selector string

	// TODO: abstract this away into a map!!!
	switch op {
	case ">":
		selector = "GT"
	case ">=":
		selector = "GTEQ"
	case "<":
		selector = "LT"
	case "<=":
		selector = "LTEQ"
	case "=":
		selector = "EQ"
	case "+":
		selector = "ADD"
	case "-":
		selector = "SUB"
	case "*":
		selector = "MUL"
	case "/":
		selector = "DIV"
	case "mod":
		if len(node.Args) > 2 {
			panic("can't calculate modulo with more than 2 arguments!")
		}
		selector = "MOD"
	}

	return makeFuncCall(makeSelectorExpr(ast.NewIdent("core"), ast.NewIdent(selector)), args)
}

func TestBadAst(t *testing.T) {
	// typeOfExpr should gracefully handle broken AST structures. Let's
	// construct some.

	// Array with bad length descriptor.
	// [Bad]int32
	badArr := ast.ArrayType{
		Len: ast.NewIdent("Bad"),
		Elt: ast.NewIdent("int32"),
	}
	typ, err := typeOfExpr(&badArr)
	assert.Equal(t, typ, nil)
	assert.Equal(t, err.Error(), "invalid array size expression")

	// Array with bad length descriptor.
	// ["How about that!"]int32
	badArr = ast.ArrayType{
		Len: &ast.BasicLit{Kind: token.STRING, Value: `"How about that!"`},
		Elt: ast.NewIdent("int32"),
	}
	typ, err = typeOfExpr(&badArr)
	assert.Equal(t, typ, nil)
	assert.Equal(t, err.Error(), "invalid array size type")

	// Array with bad length descriptor.
	// [10ii0]int32
	badArr = ast.ArrayType{
		Len: &ast.BasicLit{Kind: token.INT, Value: "10ii0"},
		Elt: ast.NewIdent("int32"),
	}
	typ, err = typeOfExpr(&badArr)
	assert.Equal(t, typ, nil)
	assert.Equal(t, err.Error(), "strconv.ParseInt: parsing \"10ii0\": invalid syntax")
}