Eclipse CDT has just had all its source code reformatted. That means I just pushed a massive set of commits with a huge git shortstat:

$ git diff --shortstat  3cf0297769..HEAD
 10806 files changed, 697885 insertions(+), 593225 deletions(-)

That also means that any commit/patch you have on CDT before the reformat will almost certainly not apply cleanly.

Therefore I have created this guide for you to reformat your commit and make it easier for you to submit your updated patch to gerrit.

To be able to rebase your commit onto the current master you need to create a version of it with the new formatting. At a high-level the steps we are going to do are:

1. Reformat your commit with CDT’s new coding style
2. Create a commit against the pre-formatted CDT that has only the files your commit changed formatted – but without your other changes

The diff between 1 and 2 above is an updated version of the diff for your real change.

Step-by-step this breaks down as:

Pre-requisites

• Modern bash shell with sed, awk, grep, git, python, etc
  • I am using Ubuntu 18.04 LTS and python 2.7
• Eclipse EASE with Py4J Python language support
  • p2 site is http://download.eclipse.org/ease/update/release
  • Install the following features
  • EASE Language Support -> EASE Py4J Support (Incubation)
  • EASE Modules -> Ease Modules (Incubation)
  • I am using EASE 0.6.0
• Eclipse workspace setup for CDT development, follow the standard setup on the wiki and perform these extra steps:
  • Import releng/scripts/formattersettings.xml Java formatter settings and set active profile to CDT
  • Import releng/scripts/cleanupsettings.xml Java Clean Up settings and set active profile to CDT
  • In Clean Up preferences uncheck the “Show profile selection dialog for the ‘Source > Clean Up’ Action”
• Copy releng/scripts/cleanup.py somewhere outside of your gitroot so you can access it as the branches change later
• Set ECLIPSE environment variable to path to eclipse on your machine to make some of the commands below easier to copy/paste

Step 1: Checkout the commit to rebase

First step is to checkout in CDT repo the commit you want to rebase onto current master. For example if you are updating a commit in gerrit, you could press Download in the top right and copy/paste the Checkout command:

Step 2: Reformat commit to new style

Start by creating a new branch to work on:

git checkout -b commit_to_rebase

git rebase 35996a5c5ca5c254959ba48241eaada6dbf8628d

git diff-tree --no-commit-id --name-only -r commit_to_rebase -- *.java | xargs $ECLIPSE

git show master:.gitattributes | awk '/# remove trailing whitespace/{getline; print $1}' |
    while read i ; do
        echo "Removing trailing whitespace on $i files"
        git diff-tree --no-commit-id --name-only -r commit_to_rebase -- "$i" | xargs --no-run-if-empty sed -i 's/[ \t]*$//'
    done

git add -u
git commit --amend --reuse-message=HEAD

git checkout 35996a5c5ca5c254959ba48241eaada6dbf8628d -b commit_to_format

git add -u
git commit -m"formatted files"

Step 4: Create a new commit that can be cherry-picked to master

git diff commit_to_format..commit_to_rebase | git apply

git add -u
git commit --reuse-message=commit_to_rebase

git checkout master
git cherry-pick commit_to_format

git branch -D commit_to_rebase
git branch -D commit_to_format