1 files changed, 118 insertions, 0 deletions
diff --git a/build/generate-go-licenses.go b/build/generate-go-licenses.go
new file mode 100644
index 00000000..84ba3902
--- /dev/null
+++ b/build/generate-go-licenses.go
@@ -0,0 +1,118 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/fs"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+
+	"code.gitea.io/gitea/modules/container"
+)
+
+// regexp is based on go-license, excluding README and NOTICE
+// https://github.com/google/go-licenses/blob/master/licenses/find.go
+var licenseRe = regexp.MustCompile(`^(?i)((UN)?LICEN(S|C)E|COPYING).*$`)
+
+type LicenseEntry struct {
+	Name        string `json:"name"`
+	Path        string `json:"path"`
+	LicenseText string `json:"licenseText"`
+}
+
+func main() {
+	if len(os.Args) != 3 {
+		fmt.Println("usage: go run generate-go-licenses.go <base-dir> <out-json-file>")
+		os.Exit(1)
+	}
+
+	base, out := os.Args[1], os.Args[2]
+
+	// Add ext for excluded files because license_test.go will be included for some reason.
+	// And there are more files that should be excluded, check with:
+	//
+	// go run github.com/google/go-licenses@v1.6.0 save . --force --save_path=.go-licenses 2>/dev/null
+	// find .go-licenses -type f | while read FILE; do echo "${$(basename $FILE)##*.}"; done | sort -u
+	//    AUTHORS
+	//    COPYING
+	//    LICENSE
+	//    Makefile
+	//    NOTICE
+	//    gitignore
+	//    go
+	//    md
+	//    mod
+	//    sum
+	//    toml
+	//    txt
+	//    yml
+	//
+	// It could be removed once we have a better regex.
+	excludedExt := container.SetOf(".gitignore", ".go", ".mod", ".sum", ".toml", ".yml")
+
+	var paths []string
+	err := filepath.WalkDir(base, func(path string, entry fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if entry.IsDir() || !licenseRe.MatchString(entry.Name()) || excludedExt.Contains(filepath.Ext(entry.Name())) {
+			return nil
+		}
+		paths = append(paths, path)
+		return nil
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	sort.Strings(paths)
+
+	var entries []LicenseEntry
+	for _, filePath := range paths {
+		licenseText, err := os.ReadFile(filePath)
+		if err != nil {
+			panic(err)
+		}
+
+		pkgPath := filepath.ToSlash(filePath)
+		pkgPath = strings.TrimPrefix(pkgPath, base+"/")
+		pkgName := path.Dir(pkgPath)
+
+		// There might be a bug somewhere in go-licenses that sometimes interprets the
+		// root package as "." and sometimes as "code.gitea.io/gitea". Workaround by
+		// removing both of them for the sake of stable output.
+		if pkgName == "." || pkgName == "code.gitea.io/gitea" {
+			continue
+		}
+
+		entries = append(entries, LicenseEntry{
+			Name:        pkgName,
+			Path:        pkgPath,
+			LicenseText: string(licenseText),
+		})
+	}
+
+	jsonBytes, err := json.MarshalIndent(entries, "", "  ")
+	if err != nil {
+		panic(err)
+	}
+
+	// Ensure file has a final newline
+	if jsonBytes[len(jsonBytes)-1] != '\n' {
+		jsonBytes = append(jsonBytes, '\n')
+	}
+
+	err = os.WriteFile(out, jsonBytes, 0o644)
+	if err != nil {
+		panic(err)
+	}
+}