clang-format: add "tools/clang-format.sh" script

Historically is libnl3 not formatted with clang-format, as the project
is old.

However, we have a mostly usable ".clang-format" file. Also, various new
files follow the automated formatting.

Add a script for helping with the reformatting.

Also, the script has an exclude list for files that should not be
formatted. That means, new files will be required to follow the
formatting. That is considered a benefit.

1 files changed, 557 insertions, 0 deletions

diff --git a/tools/clang-format.sh b/tools/clang-format.sh
new file mode 100755
index 0000000..992a810
--- /dev/null
+++ b/tools/clang-format.sh
@@ -0,0 +1,557 @@
+#!/bin/bash
+
+set -e
+
+die() {
+    printf '%s\n' "$*" >&2
+    exit 1
+}
+
+EXCLUDE_PATHS_TOPLEVEL=(
+    "include/linux-private"
+)
+
+# The following files are currently not formatted with clang.
+# Exclude them too.
+EXCLUDE_PATHS_TOPLEVEL+=(
+    "include/netlink-private/cache-api.h"
+    "include/netlink-private/genl.h"
+    "include/netlink-private/netlink.h"
+    "include/netlink-private/nl-auto.h"
+    "include/netlink-private/object-api.h"
+    "include/netlink-private/route/link/api.h"
+    "include/netlink-private/route/link/sriov.h"
+    "include/netlink-private/route/mpls.h"
+    "include/netlink-private/route/nexthop-encap.h"
+    "include/netlink-private/route/tc-api.h"
+    "include/netlink-private/socket.h"
+    "include/netlink-private/tc.h"
+    "include/netlink-private/types.h"
+    "include/netlink-private/utils.h"
+    "include/netlink/addr.h"
+    "include/netlink/attr.h"
+    "include/netlink/cache-api.h"
+    "include/netlink/cache.h"
+    "include/netlink/cli/addr.h"
+    "include/netlink/cli/cls.h"
+    "include/netlink/cli/link.h"
+    "include/netlink/cli/mdb.h"
+    "include/netlink/cli/neigh.h"
+    "include/netlink/cli/qdisc.h"
+    "include/netlink/cli/route.h"
+    "include/netlink/cli/tc.h"
+    "include/netlink/cli/utils.h"
+    "include/netlink/data.h"
+    "include/netlink/errno.h"
+    "include/netlink/fib_lookup/lookup.h"
+    "include/netlink/fib_lookup/request.h"
+    "include/netlink/genl/ctrl.h"
+    "include/netlink/genl/family.h"
+    "include/netlink/genl/genl.h"
+    "include/netlink/genl/mngt.h"
+    "include/netlink/handlers.h"
+    "include/netlink/hash.h"
+    "include/netlink/hashtable.h"
+    "include/netlink/idiag/idiagnl.h"
+    "include/netlink/idiag/meminfo.h"
+    "include/netlink/idiag/msg.h"
+    "include/netlink/idiag/req.h"
+    "include/netlink/idiag/vegasinfo.h"
+    "include/netlink/list.h"
+    "include/netlink/msg.h"
+    "include/netlink/netfilter/ct.h"
+    "include/netlink/netfilter/exp.h"
+    "include/netlink/netfilter/log.h"
+    "include/netlink/netfilter/log_msg.h"
+    "include/netlink/netfilter/netfilter.h"
+    "include/netlink/netfilter/nfnl.h"
+    "include/netlink/netfilter/queue.h"
+    "include/netlink/netfilter/queue_msg.h"
+    "include/netlink/netlink-compat.h"
+    "include/netlink/netlink-kernel.h"
+    "include/netlink/netlink.h"
+    "include/netlink/object.h"
+    "include/netlink/route/act/skbedit.h"
+    "include/netlink/route/action.h"
+    "include/netlink/route/addr.h"
+    "include/netlink/route/class.h"
+    "include/netlink/route/classifier.h"
+    "include/netlink/route/cls/basic.h"
+    "include/netlink/route/cls/cgroup.h"
+    "include/netlink/route/cls/ematch.h"
+    "include/netlink/route/cls/ematch/cmp.h"
+    "include/netlink/route/cls/ematch/meta.h"
+    "include/netlink/route/cls/ematch/nbyte.h"
+    "include/netlink/route/cls/ematch/text.h"
+    "include/netlink/route/cls/flower.h"
+    "include/netlink/route/cls/fw.h"
+    "include/netlink/route/cls/matchall.h"
+    "include/netlink/route/cls/police.h"
+    "include/netlink/route/cls/u32.h"
+    "include/netlink/route/link.h"
+    "include/netlink/route/link/api.h"
+    "include/netlink/route/link/bonding.h"
+    "include/netlink/route/link/bridge.h"
+    "include/netlink/route/link/can.h"
+    "include/netlink/route/link/geneve.h"
+    "include/netlink/route/link/inet.h"
+    "include/netlink/route/link/inet6.h"
+    "include/netlink/route/link/info-api.h"
+    "include/netlink/route/link/ip6gre.h"
+    "include/netlink/route/link/ip6tnl.h"
+    "include/netlink/route/link/ip6vti.h"
+    "include/netlink/route/link/ipgre.h"
+    "include/netlink/route/link/ipip.h"
+    "include/netlink/route/link/ipvlan.h"
+    "include/netlink/route/link/ipvti.h"
+    "include/netlink/route/link/macsec.h"
+    "include/netlink/route/link/macvlan.h"
+    "include/netlink/route/link/macvtap.h"
+    "include/netlink/route/link/ppp.h"
+    "include/netlink/route/link/sit.h"
+    "include/netlink/route/link/sriov.h"
+    "include/netlink/route/link/team.h"
+    "include/netlink/route/link/vlan.h"
+    "include/netlink/route/link/vxlan.h"
+    "include/netlink/route/link/xfrmi.h"
+    "include/netlink/route/mdb.h"
+    "include/netlink/route/neighbour.h"
+    "include/netlink/route/neightbl.h"
+    "include/netlink/route/netconf.h"
+    "include/netlink/route/nexthop.h"
+    "include/netlink/route/pktloc.h"
+    "include/netlink/route/qdisc.h"
+    "include/netlink/route/qdisc/cbq.h"
+    "include/netlink/route/qdisc/dsmark.h"
+    "include/netlink/route/qdisc/fifo.h"
+    "include/netlink/route/qdisc/fq_codel.h"
+    "include/netlink/route/qdisc/hfsc.h"
+    "include/netlink/route/qdisc/htb.h"
+    "include/netlink/route/qdisc/mqprio.h"
+    "include/netlink/route/qdisc/netem.h"
+    "include/netlink/route/qdisc/plug.h"
+    "include/netlink/route/qdisc/prio.h"
+    "include/netlink/route/qdisc/red.h"
+    "include/netlink/route/qdisc/sfq.h"
+    "include/netlink/route/route.h"
+    "include/netlink/route/rtnl.h"
+    "include/netlink/route/rule.h"
+    "include/netlink/route/tc-api.h"
+    "include/netlink/route/tc.h"
+    "include/netlink/socket.h"
+    "include/netlink/types.h"
+    "include/netlink/utils.h"
+    "include/netlink/xfrm/ae.h"
+    "include/netlink/xfrm/lifetime.h"
+    "include/netlink/xfrm/sa.h"
+    "include/netlink/xfrm/selector.h"
+    "include/netlink/xfrm/sp.h"
+    "include/netlink/xfrm/template.h"
+    "lib/addr.c"
+    "lib/attr.c"
+    "lib/cache.c"
+    "lib/cache_mngr.c"
+    "lib/cache_mngt.c"
+    "lib/cli/cls/basic.c"
+    "lib/cli/cls/cgroup.c"
+    "lib/cli/qdisc/bfifo.c"
+    "lib/cli/qdisc/blackhole.c"
+    "lib/cli/qdisc/fq_codel.c"
+    "lib/cli/qdisc/hfsc.c"
+    "lib/cli/qdisc/htb.c"
+    "lib/cli/qdisc/ingress.c"
+    "lib/cli/qdisc/pfifo.c"
+    "lib/cli/qdisc/plug.c"
+    "lib/data.c"
+    "lib/error.c"
+    "lib/fib_lookup/lookup.c"
+    "lib/fib_lookup/request.c"
+    "lib/genl/ctrl.c"
+    "lib/genl/family.c"
+    "lib/genl/genl.c"
+    "lib/genl/mngt.c"
+    "lib/handlers.c"
+    "lib/hash.c"
+    "lib/hashtable.c"
+    "lib/idiag/idiag.c"
+    "lib/idiag/idiag_meminfo_obj.c"
+    "lib/idiag/idiag_msg_obj.c"
+    "lib/idiag/idiag_req_obj.c"
+    "lib/idiag/idiag_vegasinfo_obj.c"
+    "lib/mpls.c"
+    "lib/msg.c"
+    "lib/netfilter/ct.c"
+    "lib/netfilter/ct_obj.c"
+    "lib/netfilter/exp.c"
+    "lib/netfilter/exp_obj.c"
+    "lib/netfilter/log.c"
+    "lib/netfilter/log_msg.c"
+    "lib/netfilter/log_msg_obj.c"
+    "lib/netfilter/log_obj.c"
+    "lib/netfilter/netfilter.c"
+    "lib/netfilter/nfnl.c"
+    "lib/netfilter/queue.c"
+    "lib/netfilter/queue_msg.c"
+    "lib/netfilter/queue_msg_obj.c"
+    "lib/netfilter/queue_obj.c"
+    "lib/nl.c"
+    "lib/object.c"
+    "lib/route/act.c"
+    "lib/route/act/gact.c"
+    "lib/route/act/mirred.c"
+    "lib/route/act/skbedit.c"
+    "lib/route/act/vlan.c"
+    "lib/route/addr.c"
+    "lib/route/class.c"
+    "lib/route/classid.c"
+    "lib/route/cls.c"
+    "lib/route/cls/basic.c"
+    "lib/route/cls/cgroup.c"
+    "lib/route/cls/ematch.c"
+    "lib/route/cls/ematch/cmp.c"
+    "lib/route/cls/ematch/container.c"
+    "lib/route/cls/ematch/meta.c"
+    "lib/route/cls/ematch/nbyte.c"
+    "lib/route/cls/ematch/text.c"
+    "lib/route/cls/flower.c"
+    "lib/route/cls/fw.c"
+    "lib/route/cls/mall.c"
+    "lib/route/cls/police.c"
+    "lib/route/cls/u32.c"
+    "lib/route/link.c"
+    "lib/route/link/api.c"
+    "lib/route/link/bonding.c"
+    "lib/route/link/bridge.c"
+    "lib/route/link/can.c"
+    "lib/route/link/dummy.c"
+    "lib/route/link/geneve.c"
+    "lib/route/link/ifb.c"
+    "lib/route/link/inet.c"
+    "lib/route/link/inet6.c"
+    "lib/route/link/ip6gre.c"
+    "lib/route/link/ip6tnl.c"
+    "lib/route/link/ip6vti.c"
+    "lib/route/link/ipgre.c"
+    "lib/route/link/ipip.c"
+    "lib/route/link/ipvlan.c"
+    "lib/route/link/ipvti.c"
+    "lib/route/link/macsec.c"
+    "lib/route/link/macvlan.c"
+    "lib/route/link/ppp.c"
+    "lib/route/link/sit.c"
+    "lib/route/link/sriov.c"
+    "lib/route/link/team.c"
+    "lib/route/link/veth.c"
+    "lib/route/link/vlan.c"
+    "lib/route/link/vrf.c"
+    "lib/route/link/vxlan.c"
+    "lib/route/link/xfrmi.c"
+    "lib/route/mdb.c"
+    "lib/route/neigh.c"
+    "lib/route/netconf.c"
+    "lib/route/nexthop.c"
+    "lib/route/nexthop_encap.c"
+    "lib/route/nh_encap_mpls.c"
+    "lib/route/pktloc.c"
+    "lib/route/qdisc.c"
+    "lib/route/qdisc/blackhole.c"
+    "lib/route/qdisc/cbq.c"
+    "lib/route/qdisc/dsmark.c"
+    "lib/route/qdisc/fifo.c"
+    "lib/route/qdisc/fq_codel.c"
+    "lib/route/qdisc/hfsc.c"
+    "lib/route/qdisc/htb.c"
+    "lib/route/qdisc/ingress.c"
+    "lib/route/qdisc/mqprio.c"
+    "lib/route/qdisc/netem.c"
+    "lib/route/qdisc/plug.c"
+    "lib/route/qdisc/prio.c"
+    "lib/route/qdisc/red.c"
+    "lib/route/qdisc/sfq.c"
+    "lib/route/qdisc/tbf.c"
+    "lib/route/route.c"
+    "lib/route/route_obj.c"
+    "lib/route/route_utils.c"
+    "lib/route/rtnl.c"
+    "lib/route/rule.c"
+    "lib/route/tc.c"
+    "lib/socket.c"
+    "lib/utils.c"
+    "lib/version.c"
+    "lib/xfrm/ae.c"
+    "lib/xfrm/lifetime.c"
+    "lib/xfrm/sa.c"
+    "lib/xfrm/selector.c"
+    "lib/xfrm/sp.c"
+    "lib/xfrm/template.c"
+    "python/netlink/utils.h"
+    "src/genl-ctrl-list.c"
+    "src/idiag-socket-details.c"
+    "src/lib/addr.c"
+    "src/lib/cls.c"
+    "src/lib/ct.c"
+    "src/lib/exp.c"
+    "src/lib/link.c"
+    "src/lib/neigh.c"
+    "src/lib/route.c"
+    "src/lib/tc.c"
+    "src/lib/utils.c"
+    "src/nf-ct-add.c"
+    "src/nf-ct-events.c"
+    "src/nf-ct-list.c"
+    "src/nf-exp-add.c"
+    "src/nf-exp-delete.c"
+    "src/nf-exp-list.c"
+    "src/nf-log.c"
+    "src/nf-monitor.c"
+    "src/nf-queue.c"
+    "src/nl-addr-add.c"
+    "src/nl-addr-delete.c"
+    "src/nl-addr-list.c"
+    "src/nl-class-add.c"
+    "src/nl-class-delete.c"
+    "src/nl-class-list.c"
+    "src/nl-classid-lookup.c"
+    "src/nl-cls-add.c"
+    "src/nl-cls-delete.c"
+    "src/nl-cls-list.c"
+    "src/nl-fib-lookup.c"
+    "src/nl-link-enslave.c"
+    "src/nl-link-list.c"
+    "src/nl-link-release.c"
+    "src/nl-link-set.c"
+    "src/nl-link-stats.c"
+    "src/nl-list-caches.c"
+    "src/nl-list-sockets.c"
+    "src/nl-monitor.c"
+    "src/nl-neigh-add.c"
+    "src/nl-neigh-delete.c"
+    "src/nl-neigh-list.c"
+    "src/nl-neightbl-list.c"
+    "src/nl-pktloc-lookup.c"
+    "src/nl-qdisc-add.c"
+    "src/nl-qdisc-delete.c"
+    "src/nl-qdisc-list.c"
+    "src/nl-route-add.c"
+    "src/nl-route-delete.c"
+    "src/nl-route-get.c"
+    "src/nl-route-list.c"
+    "src/nl-rule-list.c"
+    "src/nl-tctree-list.c"
+    "src/nl-util-addr.c"
+    "tests/nl-test-util.h"
+    "tests/test-cache-mngr.c"
+    "tests/test-complex-HTB-with-hash-filters.c"
+    "tests/test-create-bridge.c"
+    "tests/test-create-geneve.c"
+    "tests/test-create-ip6tnl.c"
+    "tests/test-create-ipgre.c"
+    "tests/test-create-ipgretap.c"
+    "tests/test-create-ipip.c"
+    "tests/test-create-ipvti.c"
+    "tests/test-create-macsec.c"
+    "tests/test-create-macvlan.c"
+    "tests/test-create-macvtap.c"
+    "tests/test-create-sit.c"
+    "tests/test-create-veth.c"
+    "tests/test-create-xfrmi.c"
+    "tests/test-genl.c"
+    "tests/test-nf-cache-mngr.c"
+    "tests/test-socket-creation.c"
+    "tests/test-u32-filter-with-actions.c"
+)
+
+DIR_ROOT="$(git rev-parse --show-toplevel)" || die "not inside a git repository"
+DIR_PREFIX="$(git rev-parse --show-prefix)" || die "not inside a git repository"
+
+if [ ! -f "$DIR_ROOT/.clang-format" ]; then
+    die "Error: the clang-format file in \"$DIR_ROOT\" does not exist"
+fi
+
+if ! command -v clang-format &> /dev/null; then
+    die "Error: clang-format is not installed. On RHEL/Fedora/CentOS run 'dnf install clang-tools-extra'"
+fi
+
+if test -n "$DIR_PREFIX"; then
+    EXCLUDE_PATHS=()
+    for e in "${EXCLUDE_PATHS_TOPLEVEL[@]}"; do
+        REGEX="^$DIR_PREFIX([^/].*)$"
+        if [[ "$e" =~ $REGEX ]]; then
+            EXCLUDE_PATHS+=("${BASH_REMATCH[1]}")
+        fi
+    done
+else
+    EXCLUDE_PATHS=("${EXCLUDE_PATHS_TOPLEVEL[@]}")
+fi
+
+FILES=()
+HAS_EXPLICIT_FILES=0
+SHOW_FILENAMES=0
+TEST_ONLY=0
+CHECK_UPSTREAM=
+
+usage() {
+    printf "Usage: %s [OPTION]... [FILE]...\n" "$(basename "$0")"
+    printf "Reformat source files using clang-format.\n\n"
+    printf "If no file is given the script runs on the whole codebase.\n"
+    printf "OPTIONS:\n"
+    printf "    -h                 Print this help message.\n"
+    printf "    -i                 Reformat files (the default).\n"
+    printf "    -n|--dry-run       Only check the files (contrary to \"-i\").\n"
+    printf "    -a|--all           Check all files (the default).\n"
+    printf "    -u|--upstream COMMIT Check only files from \`git diff --name-only COMMIT\` (contrary to \"-a\").\n"
+    printf "                       This also affects directories given in the [FILE] list, but not files.\n"
+    printf "                       If this is the last parameter and COMMIT is unspecified/empty, it defaults to \"main\".\n"
+    printf "    -F|--fast          Same as \`-u HEAD^\`.\n"
+    printf "    --show-filenames   Only print the filenames that would be checked/formatted\n"
+    printf "    --                 Separate options from filenames/directories\n"
+}
+
+ls_files_exist() {
+    local OLD_IFS="$IFS"
+    local f
+
+    IFS=$'\n'
+    for f in $(cat) ; do
+        test -f "$f" && printf '%s\n' "$f"
+    done
+    IFS="$OLD_IFS"
+}
+
+ls_files_filter() {
+    local OLD_IFS="$IFS"
+    local f
+
+    IFS=$'\n'
+    for f in $(cat) ; do
+        local found=1
+        local p
+        for p; do
+            [[ "$f" = "$p/"* ]] && found=
+            [[ "$f" = "$p" ]] && found=
+        done
+        test -n "$found" && printf '%s\n' "$f"
+    done
+    IFS="$OLD_IFS"
+}
+
+g_ls_files() {
+    local pattern="$1"
+    shift
+
+    if [ -z "$CHECK_UPSTREAM" ]; then
+        git ls-files -- "$pattern"
+    else
+        git diff --no-renames --name-only "$CHECK_UPSTREAM" -- "$pattern" \
+            | ls_files_exist
+    fi | ls_files_filter "$@"
+}
+
+HAD_DASHDASH=0
+while (( $# )); do
+    if [ "$HAD_DASHDASH" = 0 ]; then
+        case "$1" in
+            -h)
+                usage
+                exit 0
+                ;;
+            --show-filenames)
+                SHOW_FILENAMES=1
+                shift
+                continue
+                ;;
+            -a|--all)
+                CHECK_UPSTREAM=
+                shift
+                continue
+                ;;
+            -u|--upstream)
+                shift
+                CHECK_UPSTREAM="$1"
+                test -n "$CHECK_UPSTREAM" || CHECK_UPSTREAM=main
+                shift || :
+                continue
+                ;;
+            -F|--fast)
+                CHECK_UPSTREAM='HEAD^'
+                shift
+                continue
+                ;;
+            -n|--dry-run)
+                TEST_ONLY=1
+                shift
+                continue
+                ;;
+            -i)
+                TEST_ONLY=0
+                shift
+                continue
+                ;;
+            --)
+                HAD_DASHDASH=1
+                shift
+                continue
+                ;;
+        esac
+    fi
+    if [ -d "$1" ]; then
+        while IFS='' read -r line;
+            do FILES+=("$line")
+        done < <(CHECK_UPSTREAM="$CHECK_UPSTREAM" g_ls_files "${1}/*.[hc]" "${EXCLUDE_PATHS[@]}")
+    elif [ -f "$1" ]; then
+        FILES+=("$1")
+    else
+        usage >&2
+        echo >&2
+        die "Unknown argument \"$1\" which also is neither a file nor a directory."
+    fi
+    shift
+    HAS_EXPLICIT_FILES=1
+done
+
+if [ $HAS_EXPLICIT_FILES = 0 ]; then
+    while IFS='' read -r line; do
+        FILES+=("$line")
+    done < <(CHECK_UPSTREAM="$CHECK_UPSTREAM" g_ls_files '*.[ch]' "${EXCLUDE_PATHS[@]}")
+fi
+
+if [ $SHOW_FILENAMES = 1 ]; then
+    for f in "${FILES[@]}" ; do
+        printf '%s\n' "$f"
+    done
+    exit 0
+fi
+
+if [ "${#FILES[@]}" = 0 ]; then
+    if [ -z "$CHECK_UPSTREAM" ]; then
+        die "Error: no files to check"
+    fi
+    exit 0
+fi
+
+FLAGS_TEST=( --Werror -n --ferror-limit=1 )
+
+if [ $TEST_ONLY = 1 ]; then
+    # We assume that all formatting is correct. In that mode, passing
+    # all filenames to clang-format is significantly faster.
+    #
+    # Only in case of an error, we iterate over the files one by one
+    # until we find the first invalid file.
+    for f in "${FILES[@]}"; do
+        [ -f "$f" ] || die "Error: file \"$f\" does not exist (or is not a regular file)"
+    done
+    clang-format "${FLAGS_TEST[@]}" "${FILES[@]}" &>/dev/null && exit 0
+    for f in "${FILES[@]}"; do
+        [ -f "$f" ] || die "Error: file \"$f\" does not exist (or is not a regular file)"
+        if ! clang-format "${FLAGS_TEST[@]}" "$f" &>/dev/null; then
+            FF="$(mktemp)"
+            trap 'rm -f "$FF"' EXIT
+            clang-format "$f" 2>/dev/null > "$FF"
+            git --no-pager diff "$f" "$FF" || :
+            die "Error: file \"$f\" has style issues."$'\n'"Fix it by running \`\"$0\" -i \"$f\"\` using $(clang-format --version)"
+        fi
+    done
+    die "an unknown error happened."
+fi
+
+clang-format -i "${FILES[@]}"