tests: add "tools/check-tree.sh" script for checking consistency of sources

Our source tree also has certain consistency requirements. Since the
source is in git, this is a rather static check. However, we want to
ensure that future changes don't break it by adding a test.

Makefile.am

@@ -5435,6 +5435,7 @@ EXTRA_DIST += \
 	tools/check-exports.sh \
 	tools/check-compare-generated.sh \
 	tools/check-gitlab-ci.sh \
+	tools/check-tree.sh \
 	tools/create-exports-NetworkManager.sh \
 	tools/debug-helper.py \
 	tools/meson-post-install.sh \
@@ -5470,6 +5471,11 @@ endif
 
 ###############################################################################
 
+check-tree:
+	"$(top_srcdir)/tools/check-tree.sh"
+
+check_local += check-tree
+
 check-po-msgfmt:
 	@echo "check-po-msgfmt: check $(top_srcdir)/po/*.po files with msgfmt -vc"
 	@for f in "$(top_srcdir)/po"/*.po ; do \

meson.build

@@ -809,6 +809,11 @@ test(
   args: [source_root],
 )
 
+test(
+  'check-tree',
+  find_program(join_paths(source_root, 'tools', 'check-tree.sh')),
+)
+
 # Tests, utilities and documentation
 tests = get_option('tests')
 enable_tests = (tests != 'no')

tools/check-tree.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -e
+
+TOP_DIR="$(dirname "$0")/.."
+
+die() {
+    printf 'FAIL: %s\n' "$*" >&2
+    exit 1
+}
+
+check_cmp() {
+    local a="$1"
+    local b="$2"
+
+    cmp "$TOP_DIR/$a" "$TOP_DIR/$b" && return 0
+
+    diff "$TOP_DIR/$a" "$TOP_DIR/$b" || :
+    die "files \"$a\" and \"$b\" differ!"
+}
+
+check_cmp shared/nm-base/nm-ethtool-utils-base.h libnm/nm-ethtool-utils.h