| // Copyright 2020 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package main |
| |
| import ( |
| "errors" |
| "flag" |
| "fmt" |
| "io/fs" |
| "log" |
| "os" |
| "path" |
| "path/filepath" |
| |
| "go.fuchsia.dev/fuchsia/tools/fidl/fidlgen_go/codegen" |
| "go.fuchsia.dev/fuchsia/tools/fidl/lib/fidlgen" |
| ) |
| |
| type flagsDef struct { |
| jsonPath *string |
| outputImplPath *string |
| outputRootForIDEPath *string |
| outputPkgNamePath *string |
| } |
| |
| var flags = flagsDef{ |
| jsonPath: flag.String("json", "", |
| "relative path to the FIDL intermediate representation."), |
| outputImplPath: flag.String("output-impl", "", |
| "output path for the generated Go implementation."), |
| outputRootForIDEPath: flag.String( |
| "output-root-for-ide", |
| "", |
| "directory within which to output a symlink to the generated Go implementation "+ |
| "in order to faciliate IDE cross-references.", |
| ), |
| outputPkgNamePath: flag.String("output-pkg-name", "", |
| "output path for the generated Go implementation."), |
| } |
| |
| // valid returns true if the parsed flags are valid. |
| func (f flagsDef) valid() bool { |
| return *f.jsonPath != "" |
| } |
| |
| func printUsage() { |
| program := path.Base(os.Args[0]) |
| message := `Usage: ` + program + ` [flags] |
| |
| Go FIDL backend, used to generate Go bindings from JSON IR input (the |
| intermediate representation of a FIDL library). |
| |
| Flags: |
| ` |
| fmt.Fprint(flag.CommandLine.Output(), message) |
| flag.PrintDefaults() |
| } |
| |
| func main() { |
| flag.Usage = printUsage |
| flag.Parse() |
| if !flags.valid() { |
| printUsage() |
| os.Exit(1) |
| } |
| |
| root, err := fidlgen.ReadJSONIr(*flags.jsonPath) |
| if err != nil { |
| log.Fatal(err) |
| } |
| |
| generator := codegen.NewGenerator() |
| tree := codegen.Compile(root) |
| |
| if outputImplPath := *flags.outputImplPath; outputImplPath != "" { |
| if err := generator.GenerateImplFile(tree, outputImplPath); err != nil { |
| log.Fatalf("Error generating impl file: %v", err) |
| } |
| |
| if outputRootForIDEPath := *flags.outputRootForIDEPath; outputRootForIDEPath != "" { |
| if err := makeIDEFriendlySymlinks(ideFriendlySymlinksArgs{ |
| outputImplPath: outputImplPath, |
| outputRootForIDEPath: outputRootForIDEPath, |
| goPackageName: tree.PackageName, |
| }); err != nil { |
| log.Fatal(err) |
| } |
| } |
| } |
| |
| if outputPkgNamePath := *flags.outputPkgNamePath; outputPkgNamePath != "" { |
| if err := generator.GeneratePkgNameFile(tree, outputPkgNamePath); err != nil { |
| log.Fatalf("Error generating pkg-name file: %v", err) |
| } |
| } |
| } |
| |
| type ideFriendlySymlinksArgs struct { |
| outputImplPath string |
| outputRootForIDEPath string |
| goPackageName string |
| } |
| |
| func makeIDEFriendlySymlinks(args ideFriendlySymlinksArgs) error { |
| const permUserReadWriteExecute fs.FileMode = 0700 |
| |
| ideOutputDir := filepath.Join(args.outputRootForIDEPath, args.goPackageName) |
| if err := os.MkdirAll(ideOutputDir, permUserReadWriteExecute); err != nil { |
| return fmt.Errorf("Error creating IDE-friendly directory layout: %w", err) |
| } |
| |
| absOutputImplPath, err := filepath.Abs(args.outputImplPath) |
| if err != nil { |
| return fmt.Errorf( |
| "Error getting absolute path of generated Go implementation (relative path is %q): %w", |
| args.outputImplPath, |
| err, |
| ) |
| } |
| |
| absIDEOutputDir, err := filepath.Abs(ideOutputDir) |
| if err != nil { |
| return fmt.Errorf( |
| "Error getting absolute path of IDE-friendly directory (relative path is %q): %w", |
| ideOutputDir, |
| err, |
| ) |
| } |
| |
| symlinkPathname := filepath.Join(absIDEOutputDir, "impl.go") |
| if err := os.Remove(symlinkPathname); err != nil && !errors.Is(err, os.ErrNotExist) { |
| return fmt.Errorf("Error removing old symlink at %q: %w", symlinkPathname, err) |
| } |
| |
| relOutputImplPath, err := filepath.Rel(absIDEOutputDir, absOutputImplPath) |
| if err != nil { |
| return fmt.Errorf( |
| "Error getting relative path from %q to %q: %w", |
| absIDEOutputDir, |
| absOutputImplPath, |
| err, |
| ) |
| } |
| |
| if err := os.Symlink(relOutputImplPath, symlinkPathname); err != nil { |
| // Ignore os.ErrExist here because if multiple targets are generating the Go |
| // impl in parallel, we may race with another fidlgen_go invocation trying |
| // to create an identical symlink. |
| if !errors.Is(err, os.ErrExist) { |
| return fmt.Errorf( |
| "Error adding symlink at %q to %q: %w", |
| absOutputImplPath, |
| symlinkPathname, |
| err, |
| ) |
| } |
| } |
| |
| return nil |
| } |