go/src/fidl/compiler/backend/backend.go

// Copyright 2018 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 (
	"encoding/json"
	"fidl/compiler/backend/cpp"
	"fidl/compiler/backend/dart"
	"fidl/compiler/backend/golang"
	"fidl/compiler/backend/rust"
	"fidl/compiler/backend/types"
	"flag"
	"io/ioutil"
	"log"
	"os"
)

type GenerateFidl interface {
	GenerateFidl(fidl types.Root, config *types.Config) error
}

var generators = map[string]GenerateFidl{
	"cpp":  cpp.FidlGenerator{},
	"go":   golang.FidlGenerator{},
	"dart": dart.FidlGenerator{},
	"rust": rust.FidlGenerator{},
}

func main() {
	jsonPath := flag.String("json", "",
		"relative path to the FIDL intermediate representation.")
	outputBase := flag.String("output-base", "",
		"the base file name for files generated by this generator.")
	includeBase := flag.String("include-base", "",
		"the directory to which C and C++ includes should be relative.")
	var generatorNames CommaSeparatedList
	flag.Var(&generatorNames, "generators",
		"Comma-separated list of names of generators to run")
	flag.Parse()

	if !flag.Parsed() {
		flag.PrintDefaults()
		os.Exit(1)
	}

	if *jsonPath == "" || *outputBase == "" || *includeBase == "" {
		flag.PrintDefaults()
		os.Exit(1)
	}

	bytes, err := ioutil.ReadFile(*jsonPath)
	if err != nil {
		log.Fatalf("Error reading from %s: %v", *jsonPath, err)
	}

	var fidl types.Root
	err = json.Unmarshal(bytes, &fidl)
	if err != nil {
		log.Fatalf("Error parsing JSON as FIDL data: %v", err)
	}

	for _, l := range fidl.Libraries {
		for k, v := range l.Decls {
			fidl.Decls[types.EnsureLibrary(l.Name, k)] = v
		}
	}

	running := 0
	results := make(chan error)
	didError := false
	generatorNames = []string(generatorNames)

	config := &types.Config{
		*outputBase,
		*includeBase,
	}

	for _, generatorName := range generatorNames {
		if generator, ok := generators[generatorName]; ok {
			running++
			go func() {
				results <- generator.GenerateFidl(fidl, config)
			}()
		} else {
			log.Printf("Error: generator %s not found", generatorName)
			didError = true
		}
	}

	for running > 0 {
		err = <-results
		if err != nil {
			log.Printf("Error running generator: %v", err)
			didError = true
		}
		running--
	}

	if didError {
		os.Exit(1)
	}
}