Go Generate and AST

parse_ast.go

fs := token.NewFileSet()
ast, err := parser.ParseFile(fs, filePath, orFileSrc, parser.ParseComments)

select_all_structs_generate.go

file := os.Getenv("GOFILE")
//pkg := os.Getenv("GOPACKAGE")
fs := token.NewFileSet()
astRes, _ := parser.ParseFile(fs, file, "", parser.ParseComments)
allStructs := []*ast.TypeSpec{}
for _, d := range astRes.Decls {
	if g, ok := d.(*ast.GenDecl); ok {
		allStructs = append(allStructs, g.Specs[0].(*ast.TypeSpec))
	}
}
log.Println(len(allStructs))

select_struct_under_generate.go

file := os.Getenv("GOFILE")
//pkg := os.Getenv("GOPACKAGE")
fs := token.NewFileSet()
pos := 1	// The linear position of this generate comment
lineNum, _ := strconv.Atoi(os.Getenv("GOLINE"))
fileSrc, _ := os.ReadFile(file)
reader := strings.NewReader(string(fileSrc))
for lineNum > 0 {
	if r, _, _ := reader.ReadRune(); r == '\n' {
		lineNum--
	}
	pos++
}
astRes, _ := parser.ParseFile(fs, "", fileSrc, parser.ParseComments)
var structSpec *ast.TypeSpec = nil
for _, d := range astRes.Decls {
	if d.Pos() == token.Pos(pos) {
		if g, ok := d.(*ast.GenDecl); ok {
			structSpec = g.Specs[0].(*ast.TypeSpec)
		}
	}
}
log.Println(structSpec.Name.Name)

struct_generate.go

//go:generate go run ../generators/serialized/main.go
type SerializableThing struct {
	number   int
	name     string
	position [4]float32
}