summaryrefslogtreecommitdiffstats
path: root/Utilities/Scripts/update-third-party.bash
blob: 3b8358e0114b9afc48c104d9afbbd7ba7de48a90 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
#=============================================================================
# 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
    unrelated_histories_flag=""
    if git merge --help | grep -q -e allow-unrelated-histories; then
        unrelated_histories_flag="--allow-unrelated-histories "
    fi
    readonly unrelated_histories_flag

    git fetch "$extractdir" "upstream-$name:upstream-$name"
    git merge --log -s ours --no-commit $unrelated_histories_flag "upstream-$name"
    git read-tree -u --prefix="$subtree/" "upstream-$name"
fi
git commit --no-edit
git branch -d "upstream-$name"