Go ast库入门

留言

对于 hello.go代码如下:

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package main

func main() {
	println("Hello, World!")
}

对于hello-ast.go代码如下:

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package main

import (
	"go/ast"
	"go/parser"
	"go/token"
)

func main() {
	// 即hello.go
	src := `
package main
func main() {
    println("Hello, World!")
}
`

	// Create the AST by parsing src.
	fset := token.NewFileSet() // positions are relative to fset
	f, err := parser.ParseFile(fset, "", src, 0)
	if err != nil {
		panic(err)
	}

	// Print the AST.
	ast.Print(fset, f)

}


执行 go run hello-ast.go,结果如下:

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 0  *ast.File {
 1  .  Package: 2:1
 2  .  Name: *ast.Ident {
 3  .  .  NamePos: 2:9
 4  .  .  Name: "main"
 5  .  }
 6  .  Decls: []ast.Decl (len = 1) {
 7  .  .  0: *ast.FuncDecl {
 8  .  .  .  Name: *ast.Ident {
 9  .  .  .  .  NamePos: 3:6
10  .  .  .  .  Name: "main"
11  .  .  .  .  Obj: *ast.Object {
12  .  .  .  .  .  Kind: func
13  .  .  .  .  .  Name: "main"
14  .  .  .  .  .  Decl: *(obj @ 7)
15  .  .  .  .  }
16  .  .  .  }
17  .  .  .  Type: *ast.FuncType {
18  .  .  .  .  Func: 3:1
19  .  .  .  .  Params: *ast.FieldList {
20  .  .  .  .  .  Opening: 3:10
21  .  .  .  .  .  Closing: 3:11
22  .  .  .  .  }
23  .  .  .  }
24  .  .  .  Body: *ast.BlockStmt {
25  .  .  .  .  Lbrace: 3:13
26  .  .  .  .  List: []ast.Stmt (len = 1) {
27  .  .  .  .  .  0: *ast.ExprStmt {
28  .  .  .  .  .  .  X: *ast.CallExpr {
29  .  .  .  .  .  .  .  Fun: *ast.Ident {
30  .  .  .  .  .  .  .  .  NamePos: 4:5
31  .  .  .  .  .  .  .  .  Name: "println"
32  .  .  .  .  .  .  .  }
33  .  .  .  .  .  .  .  Lparen: 4:12
34  .  .  .  .  .  .  .  Args: []ast.Expr (len = 1) {
35  .  .  .  .  .  .  .  .  0: *ast.BasicLit {
36  .  .  .  .  .  .  .  .  .  ValuePos: 4:13
37  .  .  .  .  .  .  .  .  .  Kind: STRING
38  .  .  .  .  .  .  .  .  .  Value: "\"Hello, World!\""
39  .  .  .  .  .  .  .  .  }
40  .  .  .  .  .  .  .  }
41  .  .  .  .  .  .  .  Ellipsis: -
42  .  .  .  .  .  .  .  Rparen: 4:28
43  .  .  .  .  .  .  }
44  .  .  .  .  .  }
45  .  .  .  .  }
46  .  .  .  .  Rbrace: 5:1
47  .  .  .  }
48  .  .  }
49  .  }
50  .  Scope: *ast.Scope {
51  .  .  Objects: map[string]*ast.Object (len = 1) {
52  .  .  .  "main": *(obj @ 11)
53  .  .  }
54  .  }
55  .  Unresolved: []*ast.Ident (len = 1) {
56  .  .  0: *(obj @ 29)
57  .  }
58  }


在线AST解析工具

参考:

小窥Go ast库及初步使用

golang快速入门[4]-go语言如何编译为机器码

漫谈Go语言编译器（01）

Go 程序是如何编译成目标机器码的

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