[llvm] r305598 - utils: Add a git-r utility for mapping svn revisions to git revisions in the monorepo.

Mehdi AMINI via llvm-commits llvm-commits at lists.llvm.org
Mon Jun 19 13:28:04 PDT 2017


I'm asking you to revert now.

-- 
Mehdi


2017-06-19 13:26 GMT-07:00 Peter Collingbourne <peter at pcc.me.uk>:

> I'm not interested in participating in an extended bikeshedding debate on
> the merits of this or that language. Nor am I interested in rewriting it
> myself in some other language. I just wanted to publish a tool that I wrote
> that I find useful in the hope that others would too.
>
> I find it sad that this is the reaction, but if people would really prefer
> not to have the tool, I will remove it.
>
> Peter
>
> On Mon, Jun 19, 2017 at 12:58 PM, Mehdi AMINI <joker.eph at gmail.com> wrote:
>
>> At least, I'd expect some agreement on llvm-dev if it is OK or not to
>> have llvm dev tools depending on go before committing any.
>>
>>
>> --
>> Mehdi
>>
>> 2017-06-19 12:57 GMT-07:00 Mehdi AMINI <joker.eph at gmail.com>:
>>
>>> I agree, this shouldn't be in go.
>>>
>>> --
>>> Mehdi
>>>
>>>
>>> 2017-06-19 10:59 GMT-07:00 Peter Collingbourne via llvm-commits <
>>> llvm-commits at lists.llvm.org>:
>>>
>>>> I don't particularly care which language it is written in. I chose Go
>>>> because I felt most productive in it, and because it seemed entirely
>>>> suitable under the coding guidelines (or so I thought).
>>>>
>>>> If someone wants to rewrite it in python, that's fine with me. But it
>>>> seems more useful to have the tool written in Go than not at all.
>>>>
>>>> Peter
>>>>
>>>> On Mon, Jun 19, 2017 at 10:02 AM, David Blaikie <dblaikie at gmail.com>
>>>> wrote:
>>>>
>>>>>
>>>>>
>>>>> On Mon, Jun 19, 2017 at 10:00 AM Peter Collingbourne <peter at pcc.me.uk>
>>>>> wrote:
>>>>>
>>>>>> We already use Go in the LLVM project in a few places (llgo, llvm-go
>>>>>> and the Go bindings).
>>>>>>
>>>>>
>>>>> Those somewhat necessarily have to use go - and anyone interested in
>>>>> them probably has some context in Go.
>>>>>
>>>>>
>>>>>> We even have a section about it in the coding standards:
>>>>>>
>>>>>> http://llvm.org/docs/CodingStandards.html#other-languages
>>>>>>
>>>>>> So I don't see a problem with using Go for this tool, especially
>>>>>> given that it is relatively isolated.
>>>>>>
>>>>>
>>>>> Seems like it has broader applicability/usage, though, than the
>>>>> existing go usage.
>>>>>
>>>>> - Dave
>>>>>
>>>>>
>>>>>>
>>>>>> Peter
>>>>>>
>>>>>> On Mon, Jun 19, 2017 at 9:48 AM, David Blaikie <dblaikie at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> I think it's probably best to use a language already used in the
>>>>>>> LLVM project (Python? Bash?) than branching out into another language (Go)
>>>>>>> in terms of maintainability by other LLVM developers?
>>>>>>>
>>>>>>> On Fri, Jun 16, 2017 at 3:15 PM Peter Collingbourne via llvm-commits
>>>>>>> <llvm-commits at lists.llvm.org> wrote:
>>>>>>>
>>>>>>>> Author: pcc
>>>>>>>> Date: Fri Jun 16 17:15:18 2017
>>>>>>>> New Revision: 305598
>>>>>>>>
>>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=305598&view=rev
>>>>>>>> Log:
>>>>>>>> utils: Add a git-r utility for mapping svn revisions to git
>>>>>>>> revisions in the monorepo.
>>>>>>>>
>>>>>>>> Added:
>>>>>>>>     llvm/trunk/utils/git-svn/git-r/
>>>>>>>>     llvm/trunk/utils/git-svn/git-r/git-r.go
>>>>>>>>
>>>>>>>> Added: llvm/trunk/utils/git-svn/git-r/git-r.go
>>>>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/git-svn
>>>>>>>> /git-r/git-r.go?rev=305598&view=auto
>>>>>>>> ============================================================
>>>>>>>> ==================
>>>>>>>> --- llvm/trunk/utils/git-svn/git-r/git-r.go (added)
>>>>>>>> +++ llvm/trunk/utils/git-svn/git-r/git-r.go Fri Jun 16 17:15:18
>>>>>>>> 2017
>>>>>>>> @@ -0,0 +1,169 @@
>>>>>>>> +//===- git-r.go - svn revisions to git revisions
>>>>>>>> --------------------------===//
>>>>>>>> +//
>>>>>>>> +//                     The LLVM Compiler Infrastructure
>>>>>>>> +//
>>>>>>>> +// This file is distributed under the University of Illinois Open
>>>>>>>> Source
>>>>>>>> +// License. See LICENSE.TXT for details.
>>>>>>>> +//
>>>>>>>> +//===------------------------------------------------------
>>>>>>>> ----------------===//
>>>>>>>> +//
>>>>>>>> +// This is a small program for mapping svn revisions to git
>>>>>>>> revisions in the
>>>>>>>> +// monorepo.
>>>>>>>> +//
>>>>>>>> +// To set up:
>>>>>>>> +// 1) http://llvm.org/docs/GettingStarted.html#for-developers-to-w
>>>>>>>> ork-with-a-git-monorepo
>>>>>>>> +//    and make sure to follow the instructions for fetching commit
>>>>>>>> notes.
>>>>>>>> +// 2) go build
>>>>>>>> +// 3) cp git-r ~/bin
>>>>>>>> +//
>>>>>>>> +// To use:
>>>>>>>> +// $ git r 1
>>>>>>>> +// 09c4b68e68c4fcff64b00e1ac077c4f4a524cbcc
>>>>>>>> +//
>>>>>>>> +//===------------------------------------------------------
>>>>>>>> ----------------===//
>>>>>>>> +
>>>>>>>> +package main
>>>>>>>> +
>>>>>>>> +import (
>>>>>>>> +       "bufio"
>>>>>>>> +       "bytes"
>>>>>>>> +       "encoding/gob"
>>>>>>>> +       "fmt"
>>>>>>>> +       "log"
>>>>>>>> +       "os"
>>>>>>>> +       "os/exec"
>>>>>>>> +       "strconv"
>>>>>>>> +       "strings"
>>>>>>>> +)
>>>>>>>> +
>>>>>>>> +func git(args ...string) (*bytes.Buffer, error) {
>>>>>>>> +       cmd := exec.Command("git", args...)
>>>>>>>> +
>>>>>>>> +       var b bytes.Buffer
>>>>>>>> +       cmd.Stdout = &b
>>>>>>>> +       err := cmd.Run()
>>>>>>>> +
>>>>>>>> +       return &b, err
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +func mkrevmap() []string {
>>>>>>>> +       revs, err := git("grep", "git-svn-rev",
>>>>>>>> "refs/notes/commits")
>>>>>>>> +       if err != nil {
>>>>>>>> +               panic(err)
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       var revmap []string
>>>>>>>> +
>>>>>>>> +       scanner := bufio.NewScanner(revs)
>>>>>>>> +       for scanner.Scan() {
>>>>>>>> +               // refs/notes/commits:00/0b/d4acb
>>>>>>>> 454290301c140a1d9c4f7a45aa2fa9c:git-svn-rev: 37235
>>>>>>>> +
>>>>>>>> +               bits := strings.Split(scanner.Text(), ":")
>>>>>>>> +               gitrev := strings.Replace(bits[1], "/", "", -1)
>>>>>>>> +               svnrev := bits[3][1:]
>>>>>>>> +
>>>>>>>> +               svnrevn, err := strconv.Atoi(svnrev)
>>>>>>>> +               if err != nil {
>>>>>>>> +                       panic(err)
>>>>>>>> +               }
>>>>>>>> +
>>>>>>>> +               if svnrevn >= len(revmap) {
>>>>>>>> +                       newrevmap := make([]string, svnrevn+1)
>>>>>>>> +                       copy(newrevmap, revmap)
>>>>>>>> +                       revmap = newrevmap
>>>>>>>> +               }
>>>>>>>> +               revmap[svnrevn] = gitrev
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       return revmap
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +type revmap struct {
>>>>>>>> +       Noterev string
>>>>>>>> +       Revs    []string
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +func writerevmap(path string, rmap *revmap, svnrev int) {
>>>>>>>> +       noterevbuf, err := git("rev-parse", "refs/notes/commits")
>>>>>>>> +       if err != nil {
>>>>>>>> +               fmt.Fprintf(os.Stderr, "%s: could not find
>>>>>>>> refs/notes/commits, see instructions:\n", os.Args[0])
>>>>>>>> +               fmt.Fprintln(os.Stderr, "
>>>>>>>> http://llvm.org/docs/GettingStarted.html#for-developers-to-
>>>>>>>> work-with-a-git-monorepo")
>>>>>>>> +               os.Exit(1)
>>>>>>>> +       }
>>>>>>>> +       noterev := noterevbuf.String()
>>>>>>>> +       noterev = noterev[:len(noterev)-1]
>>>>>>>> +
>>>>>>>> +       if rmap == nil || rmap.Noterev != noterev {
>>>>>>>> +               var newrmap revmap
>>>>>>>> +               newrmap.Revs = mkrevmap()
>>>>>>>> +               newrmap.Noterev = noterev
>>>>>>>> +
>>>>>>>> +               f, err := os.Create(path)
>>>>>>>> +               if err != nil {
>>>>>>>> +                       panic(err)
>>>>>>>> +               }
>>>>>>>> +
>>>>>>>> +               enc := gob.NewEncoder(f)
>>>>>>>> +               err = enc.Encode(newrmap)
>>>>>>>> +               if err != nil {
>>>>>>>> +                       os.Remove(path)
>>>>>>>> +                       panic(err)
>>>>>>>> +               }
>>>>>>>> +
>>>>>>>> +               rmap = &newrmap
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       if svnrev >= len(rmap.Revs) || rmap.Revs[svnrev] == "" {
>>>>>>>> +               fmt.Fprintf(os.Stderr, "%s: %d: unknown
>>>>>>>> revision\n", os.Args[0], svnrev)
>>>>>>>> +               os.Exit(1)
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       fmt.Println(rmap.Revs[svnrev])
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +func main() {
>>>>>>>> +       if len(os.Args) != 2 {
>>>>>>>> +               fmt.Fprintf(os.Stderr, "%s: expected a single
>>>>>>>> argument\n", os.Args[0])
>>>>>>>> +               os.Exit(1)
>>>>>>>> +       }
>>>>>>>> +       svnrev, err := strconv.Atoi(os.Args[1])
>>>>>>>> +       if err != nil {
>>>>>>>> +               fmt.Fprintf(os.Stderr, "%s: %s: expected an integer
>>>>>>>> argument\n", os.Args[0], os.Args[1])
>>>>>>>> +               os.Exit(1)
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       gitdirbuf, err := git("rev-parse", "--git-common-dir")
>>>>>>>> +       if err != nil {
>>>>>>>> +               fmt.Fprintf(os.Stderr, "%s: not in a git
>>>>>>>> repository\n", os.Args[0])
>>>>>>>> +               os.Exit(1)
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       gitdir := gitdirbuf.String()
>>>>>>>> +       gitdir = gitdir[:len(gitdir)-1]
>>>>>>>> +       err = os.Chdir(gitdir)
>>>>>>>> +       if err != nil {
>>>>>>>> +               panic(err)
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       mappath := "git-svn-revmap-cache"
>>>>>>>> +       f, err := os.Open(mappath)
>>>>>>>> +       if err != nil {
>>>>>>>> +               writerevmap(mappath, nil, svnrev)
>>>>>>>> +               return
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       dec := gob.NewDecoder(f)
>>>>>>>> +       var rmap revmap
>>>>>>>> +       err = dec.Decode(&rmap)
>>>>>>>> +       if err != nil {
>>>>>>>> +               writerevmap(mappath, nil, svnrev)
>>>>>>>> +               return
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       if svnrev < len(rmap.Revs) && rmap.Revs[svnrev] != "" {
>>>>>>>> +               fmt.Println(rmap.Revs[svnrev])
>>>>>>>> +               return
>>>>>>>> +       }
>>>>>>>> +
>>>>>>>> +       writerevmap(mappath, &rmap, svnrev)
>>>>>>>> +}
>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> llvm-commits mailing list
>>>>>>>> llvm-commits at lists.llvm.org
>>>>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> --
>>>>>> Peter
>>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> --
>>>> Peter
>>>>
>>>> _______________________________________________
>>>> llvm-commits mailing list
>>>> llvm-commits at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>>
>>>>
>>>
>>
>
>
> --
> --
> Peter
>
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