Enable more modular arithmetic

[sbcl.git] / doc / GIT-FOR-SBCL-HACKERS.txt

diff --git a/doc/GIT-FOR-SBCL-HACKERS.txt b/doc/GIT-FOR-SBCL-HACKERS.txt
index ae9446b..4440c42 100644 (file)
--- a/doc/GIT-FOR-SBCL-HACKERS.txt
+++ b/doc/GIT-FOR-SBCL-HACKERS.txt
@@ -16,7 +16,7 @@ clone. At the time of writing there are two Git mirrors for the CVS
 history:
 
  git://sbcl.boinkor.net/sbcl.git
 history:
 
  git://sbcl.boinkor.net/sbcl.git

- 
+

 and
 
  git://repo.or.cz/sbcl.git
 and
 
  git://repo.or.cz/sbcl.git

@@ -228,7 +228,7 @@ along the lines of "My private SBCL tree. Pulls from main sbcl.git
 repository, and trickles changes back to upstream CVS manually --
 from where they end up in sbcl.git. Turtles, you see." in the comment
 box. Then you will be directed to set up an account, which you will
 repository, and trickles changes back to upstream CVS manually --
 from where they end up in sbcl.git. Turtles, you see." in the comment
 box. Then you will be directed to set up an account, which you will

-then have to add as a "pusher" to your SBCL fork. 
+then have to add as a "pusher" to your SBCL fork.

 
 Finally, add the following snippet (adjusting for your own name) in
 ~/sbcl-git/.git/config
 
 Finally, add the following snippet (adjusting for your own name) in
 ~/sbcl-git/.git/config

@@ -250,29 +250,44 @@ and you can publish your own hacks on it via git-push.
 
 Since we're not (yet?) officially using Git, we want to get our
 changes back into the CVS. git-cvsexport is the perfect tool for this.
 
 Since we're not (yet?) officially using Git, we want to get our
 changes back into the CVS. git-cvsexport is the perfect tool for this.

-This assumes that you have a developer CVS checkout in ~/sbcl-cvs, and
-wish to commit the changes you have wrought on branch foo-hacks
+
+First, to make things a bit easier, we add a command of our own to
+Git, by adding the following to ~/sbcl-git/.git/config:
+
+ [alias]
+        sbcl-export = cvsexportcommit -w /home/yourname/sbcl-cvs -v
+
+This assumes that you have a developer CVS checkout in ~/sbcl-cvs.
+
+To commit the the changes you have wrought on branch foo-hacks

 (compared to master):
 
 (compared to master):
 

+ # These three steps could be replaced by any other sequence that
+ # ends with all the changes you want to export to CVS at the top
+ # of the current branch (so that the final commit introduces all
+ # the changes.)
+ #
+ # In practice for small changes you may eg. just want to
+ #
+ #    git checkout -b wip-fix-bug-xxx master
+ #    ...fix bug on the branch...
+ #    git commit -a
+ #

  git checkout -b foo-hacks-to-cvs master
  git merge --squash foo-hacks
  git checkout -b foo-hacks-to-cvs master
  git merge --squash foo-hacks

- edit version.lisp-expr to be "CVS ready"
- git commit -a               # edit the message to be "CVS ready"
- cd ~/sbcl-cvs
- GIT_DIR=~/sbcl-git/.git git cvsexportcommit -v foo-hacks-to-cvs
- review, fix any problems
- cvs commit -F .msg
-
-To make things a bit easier, add eg. this stanza to ~/sbcl-git/.git/config:
+ git commit -a

 
 

- [alias]
-    sbcl-export = ! cd ~/sbcl-cvs && GIT_DIR=~/sbcl-git/.git git-cvsexportcommit -v
+ # This exports our stuff to the CVS tree. HEAD can be any <<commit id>>,
+ # so if you have a large number of commits on a branch that you want to
+ # commit to CVS one by one, you do that as well.
+ git sbcl-export HEAD

 
 

-Then you can just run
+ cd ../sbcl-cvs

 
 

- git sbcl-export foo-hacks-to-cvs
+ Review, fix problems, etc. Edit version.lisp-expr, and add the
+ version number to .msg (which contains the commit message from Git.)

 
 

-from inside ~/sbcl-git/, and have it prepare your CVS tree for commit.
+ cvs commit -F .msg

 
 git-cvsexportcommit is fairly conservative by default, and will fail
 if the patch doens't apply cleanly. If that happens, you can fix the
 
 git-cvsexportcommit is fairly conservative by default, and will fail
 if the patch doens't apply cleanly. If that happens, you can fix the

@@ -282,7 +297,7 @@ issues manually:
  .msg                    -- holds the commit message
 
 Finally, delete the foo-hacks-to-cvs branch after you've committed
  .msg                    -- holds the commit message
 
 Finally, delete the foo-hacks-to-cvs branch after you've committed

-code to CVS. Of course, instead of using git-cvexportcommit you can
+code to CVS. Of course, instead of using git-cvsexportcommit you can

 also manually make and apply patches, etc. For hairier cases it may
 even be easier in the end:
 
 also manually make and apply patches, etc. For hairier cases it may
 even be easier in the end:
 

@@ -296,9 +311,36 @@ foo-hacks, naming them
   ...
 
 Due to, among other things, the cvs->git synchronization lag it is
   ...
 
 Due to, among other things, the cvs->git synchronization lag it is

-easy to get conflicts on version.lisp-expr so you may want to delay
-finalizing version.lisp-expr and the .msg file that cvsexportcommit
-produced by bumping the version and adding it to the commit message.
+easy to get conflicts on version.lisp-expr so generally speaking you
+never want to edit version-lisp.expr in Git, and only edit it (and add
+the version to the commit message) just when you are about to commit
+to CVS. It is, however, nice to have an idea how a given image came to
+be, which you can take care of by putting the following code in
+branch-version.lisp-expr:
+
+ #.(flet ((git (command &rest args)
+            (with-output-to-string (s)
+              ;; Adjust for your git installation location...
+              (sb-ext:run-program (merge-pathnames "bin/git" (user-homedir-pathname))
+                                  (cons command args) :output s))))
+     (format nil "~A.~A~@[-dirty~]"
+             (with-input-from-string (s (git "branch"))
+               (loop for line = (read-line s)
+                     when (eql #\* (char line 0))
+                     return (subseq line 2)))
+             (count #\newline (git "rev-list" "HEAD...master"))
+             (plusp (length (git "diff" "HEAD")))))
+
+which leads to your Git tree build to have version names like
+
+  1.0.20.28.master.0-dirty
+
+    1.0.20.28 on branch master, uncommitted changes
+
+  1.0.20.19.wip-foo.4
+
+    1.0.20.19 on branch wip-foo, 4 commits between current HEAD and
+    master, no uncommitted changes.

 
 To get latest changes from the CVS Git mirror you originally cloned
 from, do
 
 To get latest changes from the CVS Git mirror you originally cloned
 from, do

@@ -307,6 +349,10 @@ from, do
 
 on the branch you want to update on your private repository.
 
 
 on the branch you want to update on your private repository.
 

+Note that if you edit version.lisp-expr in the CVS tree and not before
+then the cvs commit command that git-cvsexportcommit prints does not
+list version.lisp-expr, so don't copy paste it.
+

 This completes our whirlwind tour. I'm not saying this makes you
 proficient in using Git, but at least you should be up and walking.
 Reading
 This completes our whirlwind tour. I'm not saying this makes you
 proficient in using Git, but at least you should be up and walking.
 Reading

@@ -314,10 +360,12 @@ Reading
  http://eagain.net/articles/git-for-computer-scientists/
  http://www.kernel.org/pub/software/scm/git/docs/everyday.html
  http://www.kernel.org/pub/software/scm/git/docs/user-manual.html
  http://eagain.net/articles/git-for-computer-scientists/
  http://www.kernel.org/pub/software/scm/git/docs/everyday.html
  http://www.kernel.org/pub/software/scm/git/docs/user-manual.html

- 
+

 and various Git manual pages is a good idea.
 
 and various Git manual pages is a good idea.
 

-One command I can in particular recommend getting familiar with is
-git-rebase. git-gui, git-citool, and gitk provide graphical interfaces
-for working with Git -- particularly gitk is an invaluable tool for
+Two commands I can in particular recommend getting familiar with are
+git-rebase and git-cherry-pick.
+
+git-gui, git-citool, and gitk provide graphical interfaces for
+working with Git -- particularly gitk is an invaluable tool for

 visualizing history.
 visualizing history.