add file comment generation and hashing for reproducible output in proto_generator

go.sum

@@ -2,7 +2,5 @@ github.com/go-viper/mapstructure/v2 v2.4.0 h1:EBsztssimR/CONLSZZ04E8qAkxNYq4Qp9L
 github.com/go-viper/mapstructure/v2 v2.4.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
-github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
-github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

proto_generated/v1_21_11/proto.go

@@ -1,12 +1,14 @@
+// Code generated by strom. DO NOT EDIT.
+// source: minecraft-data/pc/1.21.11/protocol.json (sha256:5d0fffae79fe3d99919d16f79ed22d4c76d80fcddf92868b93abda1f55867dd8)
+// version: (devel) (go1.26.3-X:nodwarf5)
 package v1_21_11
 
 import (
 	"encoding/binary"
-	"io"
-
 	"github.com/admin-else/strom/nbt"
 	"github.com/admin-else/strom/proto_base"
 	"github.com/google/uuid"
+	"io"
 )
 
 type ArmorTrimMaterial struct {

proto_generated/v1_21_8/proto.go

@@ -1,3 +1,6 @@
+// Code generated by strom. DO NOT EDIT.
+// source: minecraft-data/pc/1.21.8/protocol.json (sha256:627f4138d1a6e4a6fff1cde6008c95a72cd580728aafca8ba62ad0ef21c88f61)
+// version: (devel) (go1.26.3-X:nodwarf5)
 package v1_21_8
 
 import (

proto_generated/v1_21_9/proto.go

@@ -1,3 +1,6 @@
+// Code generated by strom. DO NOT EDIT.
+// source: minecraft-data/pc/1.21.9/protocol.json (sha256:5c5c5947ac583745cb1ea9a8b2fa654f0356349f37fa0248ba2e44baf4e5c485)
+// version: (devel) (go1.26.3-X:nodwarf5)
 package v1_21_9
 
 import (

proto_generator/main.go

@@ -1,12 +1,14 @@
 package main
 
 import (
+	"crypto/sha256"
 	"errors"
 	"fmt"
 	"go/ast"
 	"go/token"
 	"io"
 	"os"
+	"runtime/debug"
 	"slices"
 	"strconv"
 	"strings"
@@ -319,7 +321,34 @@ func (g *Generator) GenerateProtocol(protocol Protocol, version string) (err err
 	return
 }
 
-func Generate(version string, w io.Writer) (packetInfos []PacketInfo, err error) {
+func ToolVersion() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "devel"
+	}
+	return info.Main.Version
+}
+
+func GoVersion() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "unknown"
+	}
+	return info.GoVersion
+}
+
+func HashFile(path string) (string, error) {
+	// Read from embedded filesystem since minecraft-data is embedded via go:embed
+	b, err := data.MinecraftData.ReadFile(path)
+	if err != nil {
+		return "", err
+	}
+	h := sha256.New()
+	h.Write(b)
+	return fmt.Sprintf("sha256:%x", h.Sum(nil)), nil
+}
+
+func Generate(version string, w io.Writer, sourceHash string) (packetInfos []PacketInfo, err error) {
 	protocol := Protocol{}
 	err = data.LoadVersionedJson(version, "protocol", &protocol)
 	if err != nil {
@@ -329,6 +358,15 @@ func Generate(version string, w io.Writer) (packetInfos []PacketInfo, err error)
 	g := &Generator{Protocol: protocol}
 
 	g.File = NewFile("v" + strings.ReplaceAll(version, ".", "_"))
+
+	// Add file header comment for IDE recognition and reproducibility
+	sourcePath := "minecraft-data/" + data.Paths.Data[version]["protocol"] + "/protocol.json"
+	toolVersion := ToolVersion()
+	goVersion := GoVersion()
+	comment := fmt.Sprintf("Code generated by strom. DO NOT EDIT.\nsource: %s (%s)\nversion: %s (%s)",
+		sourcePath, sourceHash, toolVersion, goVersion)
+	AddFileComment(g.File, comment)
+
 	AppendDecl(g.File, Import("encoding/binary", "io", "github.com/admin-else/strom/proto_base", "github.com/admin-else/strom/nbt", "github.com/google/uuid"))
 	g.RegisterNatives()
 	g.RegisterDecoderNatives()
@@ -354,7 +392,15 @@ func generateVersion(v string) (packetInfos []PacketInfo, err error) {
 		return
 	}
 	defer f.Close()
-	packetInfos, err = Generate(v, f)
+
+	// Compute hash of source protocol.json for reproducibility
+	sourcePath := "minecraft-data/" + data.Paths.Data[v]["protocol"] + "/protocol.json"
+	sourceHash, err := HashFile(sourcePath)
+	if err != nil {
+		return
+	}
+
+	packetInfos, err = Generate(v, f, sourceHash)
 	if err != nil {
 		return
 	}

proto_generator/printer.go

@@ -1,11 +1,13 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
 	"go/ast"
 	"go/format"
 	"go/token"
 	"io"
+	"strings"
 )
 
 func NewStruct() (s *ast.StructType) {
@@ -357,8 +359,42 @@ func AppendDecl(file *ast.File, decl ast.Decl) {
 	file.Decls = append(file.Decls, decl)
 }
 
+// AddFileComment adds a comment block at the top of the file
+func AddFileComment(f *ast.File, comment string) {
+	f.Doc = &ast.CommentGroup{}
+	lines := strings.Split(comment, "\n")
+	for _, line := range lines {
+		f.Doc.List = append(f.Doc.List, &ast.Comment{Text: "// " + line})
+	}
+}
+
 func PrintToFile(f *ast.File, w io.Writer) error {
-	return format.Node(w, token.NewFileSet(), f)
+	// Extract doc comment header if present
+	var header string
+	if f.Doc != nil {
+		for _, c := range f.Doc.List {
+			header += c.Text + "\n"
+		}
+		f.Doc = nil // Clear so go/format doesn't print it
+	}
+
+	// Format the file
+	var buf bytes.Buffer
+	if err := format.Node(&buf, token.NewFileSet(), f); err != nil {
+		return err
+	}
+
+	// Find where "package " starts in formatted output
+	formatted := buf.String()
+	pkgIndex := strings.Index(formatted, "package ")
+	if pkgIndex < 0 {
+		pkgIndex = 0
+	}
+
+	// Write header, then formatted content starting from package
+	w.Write([]byte(header))
+	w.Write([]byte(formatted[pkgIndex:]))
+	return nil
 }
 
 func IfErrNil() *ast.IfStmt {