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If you need help on making a pull request, follow this guide.
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To understand how to compile and test chisel3 from the source code, follow the instructions in SETUP.md.
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In order to contribute to chisel3, you'll need to sign the CLA agreement. You will be asked to sign it upon your first pull request.
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To introduce yourself and get help, you can join the gitter forum. If you have any questions or concerns, you can get help there.
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You can peruse the good-first-issues for easy tasks to start with. Another easy thing to start with is doing your own pass of the website looking for typos, pages missing their titles, etc. The sources for the website are here.
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Please make your PRs against the
master
branch. The project admins, when reviewing your PR, will decide which stable version (if any) your change should be backported to. The backports will be opened automatically on your behalf and you may need to do some cleanup, but focus first on yourmaster
PR.
From the Chisel3 root directory, run:
sbt scalafmtAll
You may need to specify the version, at time of writing this is:
sbt ++2.12.15 scalafmtAll
Just before the release of Chisel v3.5.0, we started using Scalafmt in this repository. Scalafmt is a code formatter; thus when it was applied in chipsalliance#2246 it caused a nearly 10,000 line diff. This introduces merge conflicts with almost every single branch from before that change. In some cases, it can be simple enough to just resolve any conflicts with a standard merge or rebase, but for some branches, this is too complicated. For such complex cases, we recommend the following procedure.
To make the following commands copy-pastable, we recommend exporting your branch name as an environment variable:
export MY_BRANCH=<name of your branch>
First, you should back up a copy of your branch in case anything goes wrong.
git branch $MY_BRANCH-backup
We also need to make sure that you have the upstream Chisel repo as a remote.
git remote add upstream https://github.com/chipsalliance/chisel3.git
git fetch upstream
You can then run the following commands:
# Make sure your branch is checked out
git checkout $MY_BRANCH
# Merge with the commit just before Scalafmt was applied
# It is possible you will have to resolve conflicts at this point
git merge upstream/just-before-scalafmt
# just-before-scalafmt is a branch that points to a commit, in case the branch gets deleted, you can instead run:
# git branch just-before-scalafmt dd36f97a82746cec0b25b94651581fe799e24579
# git merge just-before-scalafmt
# Format everything using Scalafmt
sbt scalafmtAll
# Commit the reformatted code
git commit -a -m 'Apply Scalafmt'
# Now we need to merge our changes with just after Scalafmt as applied
# Any conflicts are from our changes so we tell git to resolve conflicts by picking our changes
git merge upstream/just-after-scalafmt -X ours
# just-before-scalafmt is a branch that points to a commit, in case the branch gets deleted, you can instead run:
# git branch just-after-scalafmt 3131c0daad41dea78bede4517669e376c41a325a
# git merge just-after-scalafmt -X ours
# Most conflicts from code formatting should be resolved, now you can merge master
# There may still be some silly conflicts, but most should be avoided
git merge upstream/master
# Don't forget to push your changes!
git push origin $MY_BRANCH