Commit b3f8d490 authored by Ben Boeckel's avatar Ben Boeckel

update-common: import

parent 174b9e0d
# Updating Third Party Projects
When updating a third party project, any changes to the imported project
itself (e.g., the `zlib/vtkzlib` directory for zlib), should go through the
`update.sh` framework. This framework ensures that all patches to the third
party projects are tracked externally and available for (preferably) upstream
or other projects also embedding the library.
The projects listed in the [imported.md](imported.md) file are already using
this setup.
Any updates to projects not listed there should first convert over to this
framework.
# Updating a Project
Once converted, a project should be updated by applying patches to the
repository specified in its `update.sh` script. Once the changes are merged,
pulling the changes involves running the `update.sh` script. This will update
the local copy of the project to the version specified in `update.sh` (usually
a `for/foo` branch, but may be `master` or any other Git reference) and merge
it into the main tree.
This requires a Git 2.5 or higher due the `worktree` tool being used to
simplify the availability of the commits to the main checkout.
# Porting a Project
When converting a project, if there are any local patches, a project should be
created [on GitLab](https://gitlab.kitware.com/third-party) to track it. If
the upstream project does not use Git, it should be imported into Git (there
may be existing conversions available on Github already). The project's
description should indicate where the source repository lives.
Once a mirror of the project is created, a branch named `for/foo` should be
created where patches for the `foo` project will be applied (i.e., `for/vtk`
for VTK's patches to the project). Usually, changes to the build system, the
source code for mangling, the addition of `.gitattributes` files, and other
changes belong here. Functional changes should be submitted upstream (but may
still be tracked so that they may be used).
Making the initial import involves filling out the project's `update.sh`
script in its directory. The [update-common.sh](update-common.sh) script
describes what is necessary, but in a nutshell, it is basically metadata such
as the name of the project and where it goes in the importing project.
The most important bit is the `extract_source` function which should subset
the repository. If all that needs to be done is to extract the files given in
the `paths` variable (described in the `update-common.sh` script), the
`git_archive` function may be used if the `git archive` tool generates a
suitable subset.
Also add an entry to [imported.md](imported.md) for the project.
# Process
The basic process involves a second branch where the third party project's
changes are tracked. This branch has a commit for each time it has been
updated and is stripped to only contain the relevant parts (no unit tests,
documentation, etc.). This branch is then merged into the main branch as a
subdirectory using the `subtree` merge strategy.
Initial conversions will require a manual push by the maintainers since the
conversion involves a root commit which is not allowed under normal
circumstances. Please send an email to the mailing list asking for assistance
if necessary.
#=============================================================================
# Copyright 2015-2016 Kitware, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#=============================================================================
########################################################################
# Script for updating third party packages.
#
# This script should be sourced in a project-specific script which sets
# the following variables:
#
# name
# The name of the project.
# ownership
# A git author name/email for the commits.
# subtree
# The location of the thirdparty package within the main source
# tree.
# repo
# The git repository to use as upstream.
# tag
# The tag, branch or commit hash to use for upstream.
# shortlog
# Optional. Set to 'true' to get a shortlog in the commit message.
#
# Additionally, an "extract_source" function must be defined. It will be
# run within the checkout of the project on the requested tag. It should
# should place the desired tree into $extractdir/$name-reduced. This
# directory will be used as the newest commit for the project.
#
# For convenience, the function may use the "git_archive" function which
# does a standard "git archive" extraction using the (optional) "paths"
# variable to only extract a subset of the source tree.
########################################################################
########################################################################
# Utility functions
########################################################################
git_archive () {
git archive --worktree-attributes --prefix="$name-reduced/" HEAD -- $paths | \
tar -C "$extractdir" -x
}
die () {
echo >&2 "$@"
exit 1
}
warn () {
echo >&2 "warning: $@"
}
readonly regex_date='20[0-9][0-9]-[0-9][0-9]-[0-9][0-9]'
readonly basehash_regex="$name $regex_date ([0-9a-f]*)"
readonly basehash="$( git rev-list --author="$ownership" --grep="$basehash_regex" -n 1 HEAD )"
readonly upstream_old_short="$( git cat-file commit "$basehash" | sed -n '/'"$basehash_regex"'/ {s/.*(//;s/)//;p}' | egrep '^[0-9a-f]+$' )"
########################################################################
# Sanity checking
########################################################################
[ -n "$name" ] || \
die "'name' is empty"
[ -n "$ownership" ] || \
die "'ownership' is empty"
[ -n "$subtree" ] || \
die "'subtree' is empty"
[ -n "$repo" ] || \
die "'repo' is empty"
[ -n "$tag" ] || \
die "'tag' is empty"
[ -n "$basehash" ] || \
warn "'basehash' is empty; performing initial import"
readonly do_shortlog="${shortlog-false}"
readonly workdir="$PWD/work"
readonly upstreamdir="$workdir/upstream"
readonly extractdir="$workdir/extract"
[ -d "$workdir" ] && \
die "error: workdir '$workdir' already exists"
trap "rm -rf '$workdir'" EXIT
# Get upstream
git clone "$repo" "$upstreamdir"
if [ -n "$basehash" ]; then
# Use the existing package's history
git worktree add "$extractdir" "$basehash"
# Clear out the working tree
pushd "$extractdir"
git ls-files | xargs rm -v
find . -type d -empty -delete
popd
else
# Create a repo to hold this package's history
mkdir -p "$extractdir"
git -C "$extractdir" init
fi
# Extract the subset of upstream we care about
pushd "$upstreamdir"
git checkout "$tag"
readonly upstream_hash="$( git rev-parse HEAD )"
readonly upstream_hash_short="$( git rev-parse --short=8 "$upstream_hash" )"
readonly upstream_datetime="$( git rev-list "$upstream_hash" --format='%ci' -n 1 | grep -e "^$regex_date" )"
readonly upstream_date="$( echo "$upstream_datetime" | grep -o -e "$regex_date" )"
if $do_shortlog && [ -n "$basehash" ]; then
readonly commit_shortlog="
Upstream Shortlog
-----------------
$( git shortlog --no-merges --abbrev=8 --format='%h %s' "$upstream_old_short".."$upstream_hash" )"
else
readonly commit_shortlog=""
fi
extract_source || \
die "failed to extract source"
popd
[ -d "$extractdir/$name-reduced" ] || \
die "expected directory to extract does not exist"
readonly commit_summary="$name $upstream_date ($upstream_hash_short)"
# Commit the subset
pushd "$extractdir"
mv -v "$name-reduced/"* .
rmdir "$name-reduced/"
git add -A .
git commit -n --author="$ownership" --date="$upstream_datetime" -F - <<-EOF
$commit_summary
Code extracted from:
$repo
at commit $upstream_hash ($tag).$commit_shortlog
EOF
git branch -f "upstream-$name"
popd
# Merge the subset into this repository
if [ -n "$basehash" ]; then
git merge --log -s recursive "-Xsubtree=$subtree/" --no-commit "upstream-$name"
else
git fetch "$extractdir" "upstream-$name:upstream-$name"
git merge --log -s ours --no-commit "upstream-$name"
git read-tree -u --prefix="$subtree/" "upstream-$name"
fi
git commit --no-edit
git branch -d "upstream-$name"
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment