cmd/branch-diff/main.go

// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// The branch-diff command compares two git repos looking for changes that
// are missing in one compared to the other.
package main

import (
	"flag"
	"fmt"
	"regexp"

	"android.googlesource.com/platform/tools/gpu/client/git"
	"android.googlesource.com/platform/tools/gpu/framework/app"
	"android.googlesource.com/platform/tools/gpu/framework/file"
	"android.googlesource.com/platform/tools/gpu/framework/log"
)

var (
	src = flag.String("src", "", "the source directory")
	dst = flag.String("dst", "", "the destination directory")
	cnt = flag.Int("c", 100, "maximum number of CLs to consider")
)

func main() {
	app.ShortHelp = "branch-diff: A tool to compare two git repos for changes that exist in src and not dst."
	app.Run(run)
}

func run(ctx log.Context) error {
	if *src == "" {
		app.Usage(ctx, "Missing src directory")
		return nil
	}
	if *dst == "" {
		app.Usage(ctx, "Missing dst directory")
		return nil
	}
	src, err := git.New(file.Abs(*src).System())
	if err != nil {
		return ctx.WrapError(err, "Invalid src directory")
	}
	dst, err := git.New(file.Abs(*dst).System())
	if err != nil {
		return ctx.WrapError(err, "Invalid dst directory")
	}
	srcCLs, err := src.Log(ctx, *cnt)
	if err != nil {
		return ctx.WrapError(err, "src log")
	}
	dstCLs, err := dst.Log(ctx, *cnt)
	if err != nil {
		return ctx.WrapError(err, "dst log")
	}

	got := map[string]git.ChangeList{}
	for _, cl := range dstCLs {
		if changeID := parseChangeID(cl.Description); changeID != "" {
			got[changeID] = cl
		}
	}

	for _, cl := range srcCLs {
		if changeID := parseChangeID(cl.Description); changeID != "" {
			if _, found := got[changeID]; !found {
				parent, err := src.Parent(ctx, cl)
				if err != nil {
					return ctx.WrapError(err, "getting parent")
				}
				patch, err := src.GetPatch(ctx, parent.SHA, cl.SHA)
				if err != nil {
					return ctx.WrapError(err, "creating patch")
				}
				canApply, err := dst.CanApplyPatch(ctx, patch)
				if err != nil {
					return ctx.WrapError(err, "can apply")
				}
				applyable := '❌'
				if canApply {
					applyable = '✅'
				}
				fmt.Printf("%c  %v %-10.10s %v\n", applyable, cl.SHA.String()[:8], cl.GetLdapOrAuthor(), cl.Subject)
			}
		}
	}

	return nil
}

var reChangeID = regexp.MustCompile("Change-Id: (I.*)")

func parseChangeID(description string) string {
	matches := reChangeID.FindStringSubmatch(description)
	if len(matches) < 2 {
		return ""
	}
	return matches[1]
}