digitalresistor · March 20, 2011 08:18
diff --git a/update-branches.sh b/update-branches.sh
 cat << EOF > /dev/null

 These procedures are helpful if you have a structure like this in your source tree and it can be anything like 
 Google protobuf, grammar syntax, shared source code of some sort that gets transformed to Python and C++, or 
 really anything that has a common base from which it is derived but when included (subtree'd/submoduled in git) 
 we only need the language specific part, not the rest.

 What we do is create completely new branches in which we place a copy from the proper subdirectory from the 
 master branch. Yes that technically means we are duplicating files/commits in two different locations, but it 
 is a better option that having your Python specific source tree carrying around C++ files it does not need.

 master -\
         |- cpp
           \ - file1.cpp
         |- python
           \ - file1.py
         |- src
         |- parser.sh

 lang/python -\
              | - file1.py

 lang/cpp    -\
              | - file1.cpp

 Then when you use parser.sh to transform your src to either cpp or python, you can use the following steps 
 to update the branches.

 EOF

 # +++
 git clone ... # If you don't already have a copy of the mainline sitting around

 # or

 git checkout master
 git fetch origin
 git pull origin
 # +++

 # +++
 # Create the branches for the first time

 git branch lang/python master
 git branch lang/cpp master

 git checkout lang/python
 git filter-branch -f --subdirectory-filter python HEAD

 # Push the local branch to origin and set it to track the remote
 # in the next update you can then use git push instead...
 git push -u origin lang/python

 git checkout lang/cpp
 git filter-branch -f --subdirectory-flter cpp HEAD

 git push -u origin lang/cpp

 # +++
 # or update the branches you currently have

 # Create local branches that track the remote branches
 git branch lang/python origin/lang/python
 git branch lang/cpp origin/lang/cpp

 # Checkout the entire source code from master so we can transform it...
 git checkout -b lang/python-update master
 git filter-branch -f --subdirectory-filter python HEAD
 git checkout lang/python
 git merge lang/python-update

 # Move back to the master
 git checkout master

 # Checkout the entire source code from master so we can transform it...
 git checkout -b lang/cpp-update master
 git filter-branch -f --subdirectory-filter cpp HEAD
 git checkout lang/cpp
 git merge lang/cpp-update

 # Move back to master
 git checkout master

 # This will push lang/python, lang/cpp because we set them up to track the remote when we branched them...
 git push

 # Delete the old branches, uses uppercase D because otherwise it will complain about not fully merged
 # (mainly because you are on master, and master off course has no record of these branches since they are stand-alone)
 git branch -D lang/python-update
 git branch -D lang/cpp-update

 # +++
	cat << EOF > /dev/null

	These procedures are helpful if you have a structure like this in your source tree and it can be anything like
	Google protobuf, grammar syntax, shared source code of some sort that gets transformed to Python and C++, or
	really anything that has a common base from which it is derived but when included (subtree'd/submoduled in git)
	we only need the language specific part, not the rest.

	What we do is create completely new branches in which we place a copy from the proper subdirectory from the
	master branch. Yes that technically means we are duplicating files/commits in two different locations, but it
	is a better option that having your Python specific source tree carrying around C++ files it does not need.

	master -\
	\|- cpp
	\ - file1.cpp
	\|- python
	\ - file1.py
	\|- src
	\|- parser.sh

	lang/python -\
	\| - file1.py

	lang/cpp -\
	\| - file1.cpp

	Then when you use parser.sh to transform your src to either cpp or python, you can use the following steps
	to update the branches.

	EOF

	# +++
	git clone ... # If you don't already have a copy of the mainline sitting around

	# or

	git checkout master
	git fetch origin
	git pull origin
	# +++

	# +++
	# Create the branches for the first time

	git branch lang/python master
	git branch lang/cpp master

	git checkout lang/python
	git filter-branch -f --subdirectory-filter python HEAD

	# Push the local branch to origin and set it to track the remote
	# in the next update you can then use git push instead...
	git push -u origin lang/python

	git checkout lang/cpp
	git filter-branch -f --subdirectory-flter cpp HEAD

	git push -u origin lang/cpp

	# +++
	# or update the branches you currently have

	# Create local branches that track the remote branches
	git branch lang/python origin/lang/python
	git branch lang/cpp origin/lang/cpp

	# Checkout the entire source code from master so we can transform it...
	git checkout -b lang/python-update master
	git filter-branch -f --subdirectory-filter python HEAD
	git checkout lang/python
	git merge lang/python-update

	# Move back to the master
	git checkout master

	# Checkout the entire source code from master so we can transform it...
	git checkout -b lang/cpp-update master
	git filter-branch -f --subdirectory-filter cpp HEAD
	git checkout lang/cpp
	git merge lang/cpp-update

	# Move back to master
	git checkout master

	# This will push lang/python, lang/cpp because we set them up to track the remote when we branched them...
	git push

	# Delete the old branches, uses uppercase D because otherwise it will complain about not fully merged
	# (mainly because you are on master, and master off course has no record of these branches since they are stand-alone)
	git branch -D lang/python-update
	git branch -D lang/cpp-update

	# +++