Initial commit

tools/parse_go_ast.go

@@ -0,0 +1,194 @@
+// # Build from project root:
+// go build -o tools/parse_go_ast tools/parse_go_ast.go
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+type GoDecl struct {
+	Name       string   `json:"name"`
+	Type       string   `json:"type"`               // "func", "method", "type", "struct", "interface", "var", "package"
+	Receiver   string   `json:"receiver,omitempty"` // e.g., "*User"
+	FullName   string   `json:"full_name,omitempty"`
+	Fields     []string `json:"fields,omitempty"`  // for structs
+	Methods    []string `json:"methods,omitempty"` // for interfaces
+	DocComment string   `json:"doc_comment,omitempty"`
+	StartLine  int      `json:"start_line"`
+	EndLine    int      `json:"end_line"`
+}
+
+func astTypeToString(expr ast.Expr) string {
+	switch t := expr.(type) {
+	case *ast.Ident:
+		return t.Name
+	case *ast.StarExpr:
+		return "*" + astTypeToString(t.X)
+	case *ast.SelectorExpr:
+		return astTypeToString(t.X) + "." + t.Sel.Name
+	case *ast.ArrayType:
+		return "[]" + astTypeToString(t.Elt)
+	case *ast.MapType:
+		return "map[" + astTypeToString(t.Key) + "]" + astTypeToString(t.Value)
+	default:
+		return "unknown"
+	}
+}
+
+func extractDocComment(comments []*ast.CommentGroup, pos token.Pos, fset *token.FileSet) string {
+	if len(comments) == 0 {
+		return ""
+	}
+	line := fset.Position(pos).Line
+	for i := len(comments) - 1; i >= 0; i-- {
+		cg := comments[i]
+		cgLine := fset.Position(cg.End()).Line
+		if cgLine < line && line-cgLine <= 5 {
+			return strings.TrimSpace(cg.Text())
+		}
+	}
+	return ""
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println("Usage: parse_go_ast <file.go>")
+		os.Exit(1)
+	}
+	filename := os.Args[1]
+	src, err := ioutil.ReadFile(filename)
+	if err != nil {
+		fmt.Printf("ERR: %v\n", err)
+		os.Exit(2)
+	}
+
+	fset := token.NewFileSet()
+	fileNode, err := parser.ParseFile(fset, filename, src, parser.ParseComments)
+	if err != nil {
+		fmt.Printf("ERR: %v\n", err)
+		os.Exit(3)
+	}
+
+	decls := []GoDecl{}
+
+	// Package comment (first comment group before package decl)
+	pkgComment := ""
+	for _, cg := range fileNode.Comments {
+		if cg.Pos() < fileNode.Package {
+			pkgComment = strings.TrimSpace(cg.Text())
+		} else {
+			break
+		}
+	}
+	if pkgComment != "" {
+		decls = append(decls, GoDecl{
+			Name:       "package",
+			Type:       "package",
+			DocComment: pkgComment,
+			StartLine:  1,
+			EndLine:    1,
+		})
+	}
+
+	// Process declarations
+	for _, d := range fileNode.Decls {
+		switch d := d.(type) {
+		case *ast.FuncDecl:
+			name := d.Name.Name
+			recvType := ""
+			if d.Recv != nil && len(d.Recv.List) > 0 {
+				recvType = astTypeToString(d.Recv.List[0].Type)
+			}
+			typ := "func"
+			fullName := name
+			if recvType != "" {
+				typ = "method"
+				fullName = fmt.Sprintf("(%s).%s", recvType, name)
+			}
+			doc := extractDocComment(fileNode.Comments, d.Pos(), fset)
+			decls = append(decls, GoDecl{
+				Name:       name,
+				Type:       typ,
+				Receiver:   recvType,
+				FullName:   fullName,
+				DocComment: doc,
+				StartLine:  fset.Position(d.Pos()).Line,
+				EndLine:    fset.Position(d.End()).Line,
+			})
+
+		case *ast.GenDecl:
+			for _, spec := range d.Specs {
+				switch s := spec.(type) {
+				case *ast.TypeSpec:
+					typName := s.Name.Name
+					declType := "type"
+					var fields []string
+					var methods []string
+
+					switch t := s.Type.(type) {
+					case *ast.StructType:
+						declType = "struct"
+						for _, f := range t.Fields.List {
+							for _, n := range f.Names {
+								field := n.Name
+								if f.Tag != nil {
+									field += " " + f.Tag.Value
+								}
+								fields = append(fields, field)
+							}
+							if f.Names == nil {
+								// Embedded field
+								fields = append(fields, astTypeToString(f.Type))
+							}
+						}
+					case *ast.InterfaceType:
+						declType = "interface"
+						for _, m := range t.Methods.List {
+							if len(m.Names) > 0 {
+								methods = append(methods, m.Names[0].Name)
+							}
+						}
+					}
+
+					doc := extractDocComment(fileNode.Comments, s.Pos(), fset)
+					decls = append(decls, GoDecl{
+						Name:       typName,
+						Type:       declType,
+						Fields:     fields,
+						Methods:    methods,
+						DocComment: doc,
+						StartLine:  fset.Position(d.Pos()).Line,
+						EndLine:    fset.Position(d.End()).Line,
+					})
+
+				case *ast.ValueSpec:
+					for _, name := range s.Names {
+						doc := extractDocComment(fileNode.Comments, name.Pos(), fset)
+						// Use the individual identifier's position, not the declaration's position
+						startLine := fset.Position(name.Pos()).Line
+						endLine := fset.Position(name.End()).Line
+						
+						decls = append(decls, GoDecl{
+							Name:       name.Name,
+							Type:       "var",
+							DocComment: doc,
+							StartLine:  startLine,
+							EndLine:    endLine,
+						})
+					}
+				}
+			}
+		}
+	}
+
+	out, _ := json.Marshal(decls)
+	fmt.Println(string(out))
+}