build: track only served routes in the compatibility baseline

The baseline recorded 9,051 exported symbols of the main and internal
packages, which nothing outside this module can import, and 112 request
paths that exist only in test fixtures. Both changed with almost every
functional commit and protected no compatibility promise. The guard now
records routes from non-test files only, ignores untracked files, and drops
the symbol set; the baseline shrinks from 522 KB to 46 KB. CONTRIBUTING
explains when to refresh it.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PvgysXDmhPBBimCReYtA8q
Signed-off-by: Feng Ruohang <rh@vonng.com>

CONTRIBUTING.md

@@ -44,6 +44,10 @@ Before opening a pull request:
 
 - Add or update tests for changed behavior.
 - Run `make verifiers`.
+- If `make rebrand-guard` reports a changed compatibility set, review the
+  listed identifiers; when the change is intended, refresh the baseline with
+  `go run ./buildscripts/rebrand-guard --write` and commit
+  `buildscripts/rebrand-guard/compat-baseline.json`.
 - Run the smallest relevant package tests, then `make test` when practical.
 - Run `make build` and confirm the generated executable is `silo`.
 - Explain any preserved `MINIO_*`, `minio_*`, `x-minio-*`, `/minio/*`,

buildscripts/rebrand-guard/main.go

@@ -30,7 +30,7 @@ import (
 	"strings"
 )
 
-const manifestVersion = 3
+const manifestVersion = 4
 
 var (
 	minioImportRE = regexp.MustCompile(`github\.com/minio/[A-Za-z0-9_./-]+`)
@@ -55,7 +55,6 @@ type manifest struct {
 	GridRoutes     []string `json:"grid_routes"`
 	StorageMarkers []string `json:"storage_markers"`
 	PolicyValues   []string `json:"policy_values"`
-	ExportedSymbols []string `json:"exported_symbols"`
 	BrandAllowlist []string `json:"brand_allowlist"`
 }
 
@@ -110,7 +109,6 @@ func collect(repo string) (manifest, error) {
 		"grid":    {},
 		"storage": {},
 		"policy":  {},
-		"exported": {},
 		"brand":   {},
 	}
 	modulePath := ""
@@ -163,17 +161,17 @@ func collect(repo string) (manifest, error) {
 					sets["imports"][value] = struct{}{}
 				}
 			}
-			collectStringMatches(sets["routes"], routeRE, file)
-			collectNamedStringValues(sets["roots"], rel, file, "minioReservedBucket")
-			if rel == "internal/grid/manager.go" {
-				collectStringMatches(sets["grid"], routeRE, file)
-			}
 			if !strings.HasSuffix(rel, "_test.go") {
-				collectExported(sets["exported"], filepath.ToSlash(filepath.Dir(rel)), file)
+				// Test files hold request paths for fixtures, not served routes.
+				collectStringMatches(sets["routes"], routeRE, file)
 				if strings.HasPrefix(rel, "cmd/") || strings.HasPrefix(rel, "internal/") {
 					collectBrandStrings(sets["brand"], rel, file)
 				}
 			}
+			collectNamedStringValues(sets["roots"], rel, file, "minioReservedBucket")
+			if rel == "internal/grid/manager.go" {
+				collectStringMatches(sets["grid"], routeRE, file)
+			}
 		}
 	}
 	// This was a shell-local PID variable in the generated inspect script,
@@ -195,7 +193,6 @@ func collect(repo string) (manifest, error) {
 		GridRoutes:     sorted(sets["grid"]),
 		StorageMarkers: sorted(sets["storage"]),
 		PolicyValues:   sorted(sets["policy"]),
-		ExportedSymbols: sorted(sets["exported"]),
 		BrandAllowlist: sorted(sets["brand"]),
 	}, nil
 }
@@ -262,7 +259,7 @@ func collectStringMatches(dst map[string]struct{}, re *regexp.Regexp, file *ast.
 }
 
 func trackedFiles(repo string) ([]string, error) {
-	cmd := exec.Command("git", "-C", repo, "ls-files", "--cached", "--others", "--exclude-standard", "-z")
+	cmd := exec.Command("git", "-C", repo, "ls-files", "--cached", "-z")
 	out, err := cmd.Output()
 	if err != nil {
 		return nil, fmt.Errorf("git ls-files: %w", err)
@@ -286,78 +283,6 @@ func addMatches(dst map[string]struct{}, re *regexp.Regexp, text string, lower b
 	}
 }
 
-func collectExported(dst map[string]struct{}, dir string, file *ast.File) {
-	prefix := dir + ":" + file.Name.Name + ":"
-	for _, decl := range file.Decls {
-		switch decl := decl.(type) {
-		case *ast.FuncDecl:
-			if !ast.IsExported(decl.Name.Name) {
-				continue
-			}
-			if decl.Recv == nil {
-				dst[prefix+"func:"+decl.Name.Name] = struct{}{}
-				continue
-			}
-			receiver := receiverName(decl.Recv.List[0].Type)
-			dst[prefix+"method:"+receiver+"."+decl.Name.Name] = struct{}{}
-		case *ast.GenDecl:
-			for _, spec := range decl.Specs {
-				switch spec := spec.(type) {
-				case *ast.TypeSpec:
-					if !ast.IsExported(spec.Name.Name) {
-						continue
-					}
-					dst[prefix+"type:"+spec.Name.Name] = struct{}{}
-					collectExportedFields(dst, prefix, spec.Name.Name, spec.Type)
-				case *ast.ValueSpec:
-					kind := strings.ToLower(decl.Tok.String())
-					for _, name := range spec.Names {
-						if ast.IsExported(name.Name) {
-							dst[prefix+kind+":"+name.Name] = struct{}{}
-						}
-					}
-				}
-			}
-		}
-	}
-}
-
-func collectExportedFields(dst map[string]struct{}, prefix, typeName string, expr ast.Expr) {
-	var fields *ast.FieldList
-	switch typed := expr.(type) {
-	case *ast.StructType:
-		fields = typed.Fields
-	case *ast.InterfaceType:
-		fields = typed.Methods
-	default:
-		return
-	}
-	for _, field := range fields.List {
-		for _, name := range field.Names {
-			if ast.IsExported(name.Name) {
-				dst[prefix+"field:"+typeName+"."+name.Name] = struct{}{}
-			}
-		}
-	}
-}
-
-func receiverName(expr ast.Expr) string {
-	switch expr := expr.(type) {
-	case *ast.Ident:
-		return expr.Name
-	case *ast.StarExpr:
-		return receiverName(expr.X)
-	case *ast.IndexExpr:
-		return receiverName(expr.X)
-	case *ast.IndexListExpr:
-		return receiverName(expr.X)
-	case *ast.SelectorExpr:
-		return receiverName(expr.X) + "." + expr.Sel.Name
-	default:
-		return fmt.Sprintf("%T", expr)
-	}
-}
-
 func sorted(set map[string]struct{}) []string {
 	values := make([]string, 0, len(set))
 	for value := range set {
@@ -409,7 +334,6 @@ func compare(want, got manifest) error {
 		{"grid_routes", want.GridRoutes, got.GridRoutes},
 		{"storage_markers", want.StorageMarkers, got.StorageMarkers},
 		{"policy_values", want.PolicyValues, got.PolicyValues},
-		{"exported_symbols", want.ExportedSymbols, got.ExportedSymbols},
 		{"brand_allowlist", want.BrandAllowlist, got.BrandAllowlist},
 	}
 	for _, check := range checks {
@@ -454,10 +378,10 @@ func setDiff(want, got []string) (missing, added []string) {
 }
 
 func printSummary(value manifest) {
-	fmt.Printf("compatibility manifest: imports=%d env=%d metrics=%d headers=%d routes=%d roots=%d grid=%d storage=%d policy=%d exported=%d brand=%d sha256=%s\n",
+	fmt.Printf("compatibility manifest: imports=%d env=%d metrics=%d headers=%d routes=%d roots=%d grid=%d storage=%d policy=%d brand=%d sha256=%s\n",
 		len(value.MinioImports), len(value.Environment), len(value.Metrics), len(value.Headers),
 		len(value.Routes), len(value.RouteRoots), len(value.GridRoutes), len(value.StorageMarkers), len(value.PolicyValues),
-		len(value.ExportedSymbols), len(value.BrandAllowlist), manifestDigest(value))
+		len(value.BrandAllowlist), manifestDigest(value))
 }
 
 func manifestDigest(value manifest) string {