Add Generator for RegisterServices

build/generate-services.go

@@ -0,0 +1,213 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"text/template"
+)
+
+func main() {
+	if len(os.Args) != 5 {
+		log.Fatal("Insufficient number of arguments. Need: root filename package functionname")
+	}
+
+	root, filename, packageName, fnName := os.Args[1], os.Args[2], os.Args[3], os.Args[4]
+
+	goPackageName := os.Getenv("GOPACKAGE")
+
+	fmt.Printf("generating imports for services in %s\n", goPackageName)
+
+	// Generate the imports by walking the provided directory
+	imports := generateImports(root, packageName, fnName)
+
+	buf := &bytes.Buffer{}
+
+	// Create the importing template
+	importerTemplate.Execute(buf, struct {
+		Package string
+		Imports []string
+	}{
+		Package: goPackageName,
+		Imports: imports,
+	})
+
+	// Format the importing file
+	bs, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Write it out the filename
+	if err := ioutil.WriteFile(filename, bs, 0644); err != nil {
+		log.Fatal(err)
+	}
+}
+
+// generateImports walks from the root looking for go files that register a service
+func generateImports(root, packageName, fnName string) []string {
+	pkgNamesMap := map[string]bool{}
+	quotedPackageName := fmt.Sprintf("%q", packageName)
+	defaultAlias := packageName[strings.LastIndex(packageName, "/")+1:]
+
+	err := filepath.Walk(root, func(walkpath string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if !info.IsDir() {
+			// skip files we'll deal with them later
+			return nil
+		}
+
+		// These directories do not contain useful files
+		if strings.HasPrefix(walkpath, root+"/.") ||
+			strings.HasPrefix(walkpath, root+"/integrations") ||
+			strings.HasPrefix(walkpath, root+"/node_modules") ||
+			strings.HasPrefix(walkpath, root+"/web_src") ||
+			strings.HasPrefix(walkpath, root+"/vendor") {
+			return filepath.SkipDir
+		}
+
+		// use build to import the dir
+		pkg, err := build.ImportDir(walkpath, build.IgnoreVendor)
+		if err != nil {
+			if _, ok := err.(*build.NoGoError); ok {
+				return nil
+			}
+			return err
+		}
+
+		// Now only include dirs that import our important package
+		hasImport := false
+		for _, importName := range pkg.Imports {
+			if importName == packageName {
+				hasImport = true
+				break
+			}
+		}
+		if !hasImport {
+			return nil
+		}
+
+		// Walk the go files that are in the directory to see if they have the important service call
+		serviceCall := false
+		for _, filename := range pkg.GoFiles {
+			if strings.HasSuffix(filename, "_test.go") {
+				continue
+			}
+			if hasServiceCall(walkpath+"/"+filename, quotedPackageName, defaultAlias, fnName) {
+				serviceCall = true
+				break
+			}
+		}
+
+		if serviceCall {
+			pkgNamesMap[path.Clean("code.gitea.io/gitea/"+path.Clean("/"+filepath.ToSlash(walkpath)))] = true
+		}
+		return nil
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	pkgNames := make([]string, 0, len(pkgNamesMap))
+	for key := range pkgNamesMap {
+		pkgNames = append(pkgNames, key)
+	}
+	return pkgNames
+}
+
+func hasServiceCall(filename, quotedPackageName, defaultAlias, fnName string) bool {
+	fset := token.NewFileSet()
+	file, err := parser.ParseFile(fset, filename, nil, parser.DeclarationErrors)
+	if err != nil {
+		log.Fatal(err)
+	}
+	hasServiceCall := false
+
+	alias := ""
+	for _, importSpec := range file.Imports {
+		if importSpec.Path.Value == quotedPackageName {
+			if importSpec.Name == nil {
+				alias = defaultAlias
+			} else {
+				alias = importSpec.Name.Name
+			}
+			break
+		}
+	}
+	if alias == "" || alias == "_" {
+		return false
+	}
+
+	visitor := &serviceVisitor{
+		alias:  alias,
+		fnName: fnName,
+	}
+	ast.Walk(visitor, file)
+	if visitor.hasServiceCall {
+		hasServiceCall = true
+	}
+
+	return hasServiceCall
+}
+
+type serviceVisitor struct {
+	alias          string
+	fnName         string
+	hasServiceCall bool
+}
+
+func (v *serviceVisitor) Visit(node ast.Node) ast.Visitor {
+	if !isCall(node, v.alias, v.fnName) {
+		return v
+	}
+
+	v.hasServiceCall = true
+	return nil
+}
+
+func isCall(node ast.Node, alias, fn string) bool {
+	call, ok := node.(*ast.CallExpr)
+	if !ok {
+		return false
+	}
+
+	sel, ok := call.Fun.(*ast.SelectorExpr)
+	if !ok {
+		return false
+	}
+
+	aliasId, ok := sel.X.(*ast.Ident)
+	if !ok {
+		return false
+	}
+
+	return aliasId.Name == alias && sel.Sel.Name == fn
+}
+
+var importerTemplate = template.Must(template.New("").Parse(`// Code generated by go generate; DO NOT EDIT.
+// This file was generated by generate-services.go
+package {{.Package}}
+
+import (
+	{{range .Imports}}_ "{{.}}"
+{{end}}
+)
+`))

routers/init.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
+//go:generate go run -mod=vendor ../build/generate-services.go .. generated_init.go code.gitea.io/gitea/modules/services RegisterService
 package routers
 
 import (