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go/src/cmd/buildid/buildid.go
Hiroshi Ioka afd090c0c0 cmd/buildid: fix rewrite algorithm
Update rewrite algorithm by coping code from
go/internal/work/buildid:updateBuildID.

Probably, this is not the best option. We could provide high-level API
in cmd/internal/buildid in the future.

Fixes #23181

Change-Id: I336a7c50426ab39bc9998b55c372af61a4fb21a7
Reviewed-on: https://go-review.googlesource.com/84735
Reviewed-by: Russ Cox <rsc@golang.org>
2018-01-04 16:56:51 +00:00

91 lines
1.8 KiB
Go

// Copyright 2017 The Go 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 (
"flag"
"fmt"
"log"
"os"
"strings"
"cmd/internal/buildid"
)
func usage() {
fmt.Fprintf(os.Stderr, "usage: go tool buildid [-w] file\n")
flag.PrintDefaults()
os.Exit(2)
}
var wflag = flag.Bool("w", false, "write build ID")
// taken from cmd/go/internal/work/buildid.go
func hashToString(h [32]byte) string {
const b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
const chunks = 5
var dst [chunks * 4]byte
for i := 0; i < chunks; i++ {
v := uint32(h[3*i])<<16 | uint32(h[3*i+1])<<8 | uint32(h[3*i+2])
dst[4*i+0] = b64[(v>>18)&0x3F]
dst[4*i+1] = b64[(v>>12)&0x3F]
dst[4*i+2] = b64[(v>>6)&0x3F]
dst[4*i+3] = b64[v&0x3F]
}
return string(dst[:])
}
func main() {
log.SetPrefix("buildid: ")
log.SetFlags(0)
flag.Usage = usage
flag.Parse()
if flag.NArg() != 1 {
usage()
}
file := flag.Arg(0)
id, err := buildid.ReadFile(file)
if err != nil {
log.Fatal(err)
}
if !*wflag {
fmt.Printf("%s\n", id)
return
}
// Keep in sync with src/cmd/go/internal/work/buildid.go:updateBuildID
f, err := os.Open(file)
if err != nil {
log.Fatal(err)
}
matches, hash, err := buildid.FindAndHash(f, id, 0)
if err != nil {
log.Fatal(err)
}
f.Close()
newID := id[:strings.LastIndex(id, "/")] + "/" + hashToString(hash)
if len(newID) != len(id) {
log.Fatalf("%s: build ID length mismatch %q vs %q", file, id, newID)
}
if len(matches) == 0 {
return
}
f, err = os.OpenFile(file, os.O_WRONLY, 0)
if err != nil {
log.Fatal(err)
}
if err := buildid.Rewrite(f, matches, newID); err != nil {
log.Fatal(err)
}
if err := f.Close(); err != nil {
log.Fatal(err)
}
}