fix: correct comment parsing for block comments and update gogen to v1.20.2

This fixes issue #618 by properly handling multi-line C block comments
according to Go's ast.Comment specification.

Changes:
- Fixed ParseComment() in _xtool/internal/parser/parser.go to keep
  block comments (/* ... */) as single ast.Comment nodes instead of
  splitting them by line
- Line comments (//) continue to be split per line as expected
- Updated gogen dependency from v1.19.7 to v1.20.2

The bug was exposed when gogen v1.20.2 became more spec-compliant with
Go's standard ast printer behavior. The fix ensures llcppg generates
valid Go code that compiles correctly with the updated gogen version.

Generated with [codeagent](https://github.com/qbox/codeagent)
Co-authored-by: luoliwoshang <[email protected]>

Author: xgopilot

_xtool/internal/parser/parser.go

@@ -193,11 +193,28 @@ func (ct *Converter) ParseCommentGroup(cursor clang.Cursor) (comentGroup *ast.Co
 }
 
 func (ct *Converter) ParseComment(rawComment string) *ast.CommentGroup {
-	lines := strings.Split(rawComment, "\n")
 	commentGroup := &ast.CommentGroup{}
-	for _, line := range lines {
-		commentGroup.List = append(commentGroup.List, &ast.Comment{Text: line + "\n"})
+
+	// Block comments (/* ... */ or /** ... */) should be kept as a single Comment node.
+	// Go's ast.Comment documentation states: "A Comment node represents a single //-style or /*-style comment."
+	// This means the entire block comment must be ONE ast.Comment node, not split across multiple nodes.
+	if strings.HasPrefix(rawComment, "/*") {
+		// Ensure the comment ends with newline for proper formatting
+		text := rawComment
+		if !strings.HasSuffix(text, "\n") {
+			text += "\n"
+		}
+		commentGroup.List = append(commentGroup.List, &ast.Comment{Text: text})
+	} else {
+		// Line comments (// or ///) - each line is a separate Comment node
+		lines := strings.Split(rawComment, "\n")
+		for _, line := range lines {
+			if line != "" {
+				commentGroup.List = append(commentGroup.List, &ast.Comment{Text: line + "\n"})
+			}
+		}
 	}
+
 	return commentGroup
 }
 

go.mod

@@ -3,7 +3,7 @@ module github.com/goplus/llcppg
 go 1.23.0
 
 require (
-	github.com/goplus/gogen v1.19.7
+	github.com/goplus/gogen v1.20.2
 	github.com/goplus/lib v0.3.1
 	github.com/goplus/llgo v0.12.0
 	github.com/goplus/mod v0.19.0

go.sum

@@ -1,5 +1,5 @@
-github.com/goplus/gogen v1.19.7 h1:0i30on0GwtYIJ+D9/I5QujswBU+mnnmNewoRk/uRVkw=
-github.com/goplus/gogen v1.19.7/go.mod h1:owX2e1EyU5WD+Nm6oH2m/GXjLdlBYcwkLO4wN8HHXZI=
+github.com/goplus/gogen v1.20.2 h1:c9wm7NzjWSrncbtH+lz4jM2j31p+6JTji8cjF1K79qg=
+github.com/goplus/gogen v1.20.2/go.mod h1:87ZJD1mdljXx2pkvBrMGynGUz6m08brj9p6xhb5aq2Y=
 github.com/goplus/lib v0.3.1 h1:Xws4DBVvgOMu58awqB972wtvTacDbk3nqcbHjdx9KSg=
 github.com/goplus/lib v0.3.1/go.mod h1:SgJv3oPqLLHCu0gcL46ejOP3x7/2ry2Jtxu7ta32kp0=
 github.com/goplus/llgo v0.12.0 h1:UhbmwR+9fSy1y944rp6fPkSP39n4YhH4TpAN2QJ15ns=