From fea8299ff30517dcbd42f5a4587fef1cb0fe8d7b Mon Sep 17 00:00:00 2001
From: Gustavo Jose de Sousa <gustavo.sousa@intel.com>
Date: Thu, 3 Sep 2015 19:15:58 -0300
Subject: [PATCH] Tools: gittools: add git-commit-subsystems

A git extension for committing multiple subsystems.
---
 Tools/gittools/git-commit-subsystems | 202 +++++++++++++++++++++++++++
 1 file changed, 202 insertions(+)
 create mode 100755 Tools/gittools/git-commit-subsystems

diff --git a/Tools/gittools/git-commit-subsystems b/Tools/gittools/git-commit-subsystems
new file mode 100755
index 0000000000..4ef3805996
--- /dev/null
+++ b/Tools/gittools/git-commit-subsystems
@@ -0,0 +1,202 @@
+#!/bin/bash
+
+SCRIPT_DIR=$(dirname $(realpath ${BASH_SOURCE[0]}))
+GIT_DIR=$(git rev-parse --git-dir)
+GIT_ROOT=$(git rev-parse --show-toplevel)
+
+usage() {
+    cat >&$1 <<EOF
+Usage: git commit-subsystems [OPTIONS]
+
+Ardupilot's git extension.
+
+Create a different commit for each ardupilot's subsystem (vehicles, libraries
+and folders in the project's root). The items in OPTIONS are passed down to the
+original git commit command with exception of options --message and --file (and
+their short versions). Boths are related to the commit message:
+commit-subsystems will treat the commit message from one of those two options
+as a template such that occurrences of \$subsystem are replaced with the
+subsystem being currently committed.
+
+If neither --message or --file are passed, then the first commit's message will
+be used as a template for the other messages and option --edit will be used for
+the next commits. To avoid that behavior use --naive.
+
+Another custom option is --raw: don't use commit message as a template.
+EOF
+}
+
+MSG_FILE="$GIT_DIR/COMMIT_SUBSYSTEM_MSG"
+extra_options=
+
+process_msg() {
+    local subsystem=$1
+    local prev_subsystem=$2
+    if [[ -n "$option_m" || -n "$option_F" ]]; then
+        if [[ $option_F == - ]]; then
+            echo "Please, type the commits message template:"
+            option_F="$GIT_DIR/COMMIT_SUBSYSTEM_TEMPLATE"
+            cat - > "$option_F"
+        fi
+
+        if [[ -n "$option_m" ]]; then
+            echo "$option_m"
+        else
+            cat "$option_F"
+        fi | if $option_raw; then
+                cat
+             else
+                sed "s,\$subsystem,$cur_subsystem,g"
+             fi > "$MSG_FILE"
+
+
+        extra_options=(-F "$MSG_FILE")
+    elif [[ -n $prev_subsystem ]] && ! $option_naive; then # try to be "smart"
+        cat $GIT_DIR/COMMIT_EDITMSG \
+            | sed -e "/^\s*#/d" \
+                  -e "s/.*\<$prev_subsystem\>.*/\0\n#\0/" \
+            | sed "/^[^#]/ s/\<$prev_subsystem\>/$subsystem/g" > "$MSG_FILE"
+        echo >> "$MSG_FILE"
+        echo "# This commit message was adapted by commit-subsystems" >> "$MSG_FILE"
+        extra_options=(-F "$MSG_FILE" --edit)
+    fi
+}
+
+commit_subsystem() {
+    local subsystem=$1
+    local prev_subsystem=$2
+    shift 2
+    process_msg $subsystem $prev_subsystem
+    if ! git commit ${extra_options[*]} "$@"; then
+        echo "Couldn't commit subsystem $subsystem, aborting..." >&2
+        exit 1
+    fi
+}
+
+args=()
+
+option_m=
+option_F=
+option_naive=false
+option_raw=false
+
+while [[ -n "$1" ]]; do
+    opt="$1"
+    case "$opt" in
+    -h|--help)
+        usage 1
+        exit 0
+        ;;
+    -m|--message)
+        shift
+        if [[ -z "$1" ]]; then
+            echo "Option $opt requires a commit message." >&2
+            exit 1
+        fi
+        option_m="$1"
+        ;;
+    -F|--file)
+        shift
+        if [[ -z "$1" ]]; then
+            echo "Option $opt requires a file name." >&2
+            exit 1
+        fi
+        option_F="$1"
+        ;;
+    --naive)
+        option_naive=true
+        ;;
+    --raw)
+        option_raw=true
+        ;;
+    *)
+        args+=("$1")
+        ;;
+    esac
+    shift
+done
+
+if [[ -n $option_m && -n $option_F ]]; then
+    echo "Options -m and -F can't be combined." >&2
+    exit 1
+fi
+
+set -- "${args[@]}"
+
+LIST=$GIT_DIR/COMMIT_SUBSYSTEMS_LIST
+
+git diff --name-only --staged | $SCRIPT_DIR/path-libraries.sh -p > $LIST
+git diff --name-only --staged | $SCRIPT_DIR/path-nonlibraries.sh -p >> $LIST
+
+if [[ $(cat "$LIST" | wc -l) -eq 0 ]]; then
+    echo "Nothing to commit." >&2
+    exit 1
+fi
+
+echo "Reseting changes in order to add files separately..."
+git reset >/dev/null
+
+# head before commits - for recovery
+RECOVERY_HEAD=$(git log -n 1 --format=%H)
+exit_hook() {
+    local last_error=$?
+
+    set +e
+
+    [[ -a /dev/fd/3 ]] && exec 3<&-
+
+    [[ $last_error -eq 0 ]] && return 0
+
+    echo
+    echo "Program interrupted or finished with error(s), reseting head..." >&2
+    git reset $RECOVERY_HEAD >/dev/null
+    echo "Trying to re-add files..." >&2
+    if [[ ! -f $LIST ]]; then
+        echo "File with list of added files not found..." >&2
+    else
+        error=false
+        cat $LIST | while read subsystem path; do
+            if ! git add -- "$GIT_ROOT/$path"; then
+                echo "Couldn't add \"$path\"..." >&2
+                error=true
+            fi
+        done
+
+        if $error; then
+            echo "This is embarrassing, couldn't re-add all files. Sorry." >&2
+        else
+            echo "Files re-added." >&2
+        fi
+    fi
+
+    return 1
+}
+
+set -e
+trap "exit 1" SIGINT
+trap exit_hook EXIT
+
+echo "Adding and committing subsystems..."
+exec 3< $LIST
+cur_subsystem=
+prev_subsystem=
+empty=true
+while read -u 3 subsystem path; do
+    empty=false
+    if [[ $cur_subsystem != $subsystem ]]; then
+        if [[ -n $cur_subsystem ]]; then
+            commit_subsystem "$cur_subsystem" "$prev_subsystem" "$@"
+            echo
+        fi
+        prev_subsystem=$cur_subsystem
+        cur_subsystem=$subsystem
+    fi
+    if ! git add -- "$GIT_ROOT/$path"; then
+        echo "Couldn't add \"$path\", aborting..." >&2
+        exit 1
+    fi
+done
+
+# the last one
+commit_subsystem "$cur_subsystem" "$prev_subsystem" "$@"
+echo