build: Add script to update the unsupported devices from wiki

Avoid some more manual labor

libfprint/fprint-list-udev-hwdb.c

@@ -26,9 +26,10 @@
 
 static const FpIdEntry allowlist_id_table[] = {
   /* Currently known and unsupported devices.
-   * You can generate this list from the wiki page using e.g.:
-   *   gio cat https://gitlab.freedesktop.org/libfprint/wiki/-/wikis/Unsupported-Devices.md | sed -n 's!|.*\([0-9a-fA-F]\{4\}\):\([0-9a-fA-F]\{4\}\).*|.*!  { .vid = 0x\1, .pid = 0x\2 },!p'
+   * You can regenerate this list from the wiki page with:
+   *   meson compile -C <build-dir> sync-unsupported-devices
    */
+  /* --- BEGIN GENERATED IDS --- */
   { .vid = 0x0a5c, .pid = 0x5802 },
   { .vid = 0x047d, .pid = 0x00f2 },
   { .vid = 0x047d, .pid = 0x8054 },
@@ -166,6 +167,7 @@ static const FpIdEntry allowlist_id_table[] = {
   { .vid = 0x298d, .pid = 0x2033 },
   { .vid = 0x2df0, .pid = 0x0003 },
   { .vid = 0x3538, .pid = 0x0930 },
+  /* --- END GENERATED IDS --- */
   { .vid = 0 },
 };
 

libfprint/meson.build

@@ -301,8 +301,9 @@ libfprint_private_dep = declare_dependency(
     ]
 )
 
+udev_hwdb_list_file = files('fprint-list-udev-hwdb.c')
 udev_hwdb = executable('fprint-list-udev-hwdb',
-    'fprint-list-udev-hwdb.c',
+    udev_hwdb_list_file,
     dependencies: libfprint_private_dep,
     link_with: libfprint_drivers,
     install: false,
@@ -366,6 +367,10 @@ sync_udev_udb = custom_target('sync-udev-hwdb',
 
 alias_target('sync-udev-hwdb', sync_udev_udb)
 
+run_target('sync-unsupported-devices',
+    command: [ sync_unsupported_files, udev_hwdb_list_file ]
+)
+
 supported_devices = executable('fprint-list-supported-devices',
     'fprint-list-supported-devices.c',
     dependencies: libfprint_private_dep,

meson.build

@@ -11,6 +11,8 @@ project('libfprint', [ 'c', 'cpp' ],
 fs = import('fs')
 gnome = import('gnome')
 
+python3 = find_program('python3')
+
 libfprint_conf = configuration_data()
 libfprint_conf.set_quoted('LIBFPRINT_VERSION', meson.project_version())
 
@@ -101,6 +103,8 @@ mathlib_dep = cc.find_library('m', required: false)
 sh = find_program('sh', required: true)
 cairo_dep = dependency('cairo', required: false)
 
+sync_unsupported_files = files('scripts' / 'sync-unsupported-devices.py')
+
 # introspection scanning and Gio-2.0.gir
 gobject_introspection = dependency('gobject-introspection-1.0', required: get_option('introspection'))
 

scripts/sync-unsupported-devices.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+#
+# Update the hardcoded allowlist of currently unsupported devices in
+# fprint-list-udev-hwdb.c from the libfprint wiki page.
+
+import argparse
+import re
+import sys
+from urllib.request import urlopen
+
+DEFAULT_URL = (
+    "https://gitlab.freedesktop.org/libfprint/wiki/-/wikis/Unsupported-Devices.md"
+)
+
+ID_RE = re.compile(r"\|.*([0-9a-fA-F]{4}):([0-9a-fA-F]{4}).*\|.*")
+
+BEGIN_MARKER = "  /* --- BEGIN GENERATED IDS --- */\n"
+END_MARKER = "  /* --- END GENERATED IDS --- */\n"
+
+
+def fetch(url):
+    try:
+        with urlopen(url) as response:
+            return response.read().decode("utf-8")
+    except OSError as exc:
+        print(f"Could not download {url}: {exc}", file=sys.stderr)
+        sys.exit(77)
+
+
+def parse_entries(text):
+    devices = set()
+    for line in text.splitlines():
+        match = ID_RE.match(line)
+        if match:
+            devices.add((match.group(1).lower(), match.group(2).lower()))
+    return [f"  {{ .vid = 0x{vid}, .pid = 0x{pid} }}," for vid, pid in sorted(devices)]
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("source_file", help="Path to hwdb file")
+    parser.add_argument("--url", default=DEFAULT_URL, help="Wiki page URL")
+    args = parser.parse_args()
+
+    entries = parse_entries(fetch(args.url))
+    if not entries:
+        sys.exit("No device ids found on the wiki page")
+
+    with open(args.source_file, "r", encoding="utf-8") as f:
+        content = f.read()
+
+    before, begin, rest = content.partition(BEGIN_MARKER)
+    _, end, after = rest.partition(END_MARKER)
+    if not begin or not end:
+        sys.exit("Could not locate generated id markers in " + args.source_file)
+
+    block = BEGIN_MARKER + "\n".join(entries) + "\n" + END_MARKER
+    new_content = before + block + after
+
+    if new_content == content:
+        print("allowlist_id_table is already up to date")
+        return
+
+    with open(args.source_file, "w", encoding="utf-8") as f:
+        f.write(new_content)
+
+    print(f"Updated allowlist_id_table with {len(entries)} entries")
+
+
+if __name__ == "__main__":
+    main()

tests/meson.build

@@ -26,8 +26,6 @@ envs.set('FP_PRINTS_PATH', meson.project_source_root() / 'examples' / 'prints')
 
 envs.set('NO_AT_BRIDGE', '1')
 
-python3 = find_program('python3')
-
 installed_tests = get_option('installed-tests')
 installed_tests_execdir = libexecdir / 'installed-tests' / versioned_libname
 installed_tests_testdir = datadir / 'installed-tests' / versioned_libname