1 files changed, 91 insertions, 0 deletions
diff --git a/devtools/shared/css/generated/mach_commands.py b/devtools/shared/css/generated/mach_commands.py
new file mode 100644
index 000000000..4d6016276
--- /dev/null
+++ b/devtools/shared/css/generated/mach_commands.py
@@ -0,0 +1,91 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+"""
+This script implements the `mach devtools-css-db` command. It runs an xpcshell script
+that uses inIDOMUtils to query the CSS properties used by the browser. This information
+is used to generate the properties-db.js file.
+"""
+
+import json
+import os
+import sys
+import string
+import subprocess
+from mozbuild.base import (
+    MozbuildObject,
+    MachCommandBase,
+)
+from mach.decorators import (
+    CommandProvider,
+    Command,
+)
+
+def resolve_path(start, relativePath):
+    """Helper to resolve a path from a start, and a relative path"""
+    return os.path.normpath(os.path.join(start, relativePath))
+
+def stringify(obj):
+    """Helper to stringify to JSON"""
+    return json.dumps(obj, sort_keys=True, indent=2, separators=(',', ': '))
+
+@CommandProvider
+class MachCommands(MachCommandBase):
+    @Command(
+        'devtools-css-db', category='post-build',
+        description='Rebuild the devtool\'s static css properties database.')
+    def generate_css_db(self):
+        """Generate the static css properties database for devtools and write it to file."""
+
+        print("Re-generating the css properties database...")
+        db = self.get_properties_db_from_xpcshell()
+
+        self.output_template({
+            'cssProperties': stringify(db['cssProperties']),
+            'pseudoElements': stringify(db['pseudoElements'])})
+
+    def get_properties_db_from_xpcshell(self):
+        """Generate the static css properties db for devtools from an xpcshell script."""
+        build = MozbuildObject.from_environment()
+
+        # Get the paths
+        script_path = resolve_path(self.topsrcdir,
+            'devtools/shared/css/generated/generate-properties-db.js')
+        gre_path = resolve_path(self.topobjdir, 'dist/bin')
+        browser_path = resolve_path(self.topobjdir, 'dist/bin/browser')
+        xpcshell_path = build.get_binary_path(what='xpcshell')
+        print(browser_path)
+
+        sub_env = dict(os.environ)
+        if sys.platform.startswith('linux'):
+            sub_env["LD_LIBRARY_PATH"] = gre_path
+
+        # Run the xcpshell script, and set the appdir flag to the browser path so that
+        # we have the proper dependencies for requiring the loader.
+        contents = subprocess.check_output([xpcshell_path, '-g', gre_path,
+                                            '-a', browser_path, script_path],
+                                           env = sub_env)
+        # Extract just the output between the delimiters as the xpcshell output can
+        # have extra output that we don't want.
+        contents = contents.split('DEVTOOLS_CSS_DB_DELIMITER')[1]
+
+        return json.loads(contents)
+
+    def output_template(self, substitutions):
+        """Output a the properties-db.js from a template."""
+        js_template_path = resolve_path(self.topsrcdir,
+            'devtools/shared/css/generated/properties-db.js.in')
+        destination_path = resolve_path(self.topsrcdir,
+            'devtools/shared/css/generated/properties-db.js')
+
+        with open(js_template_path, 'rb') as handle:
+            js_template = handle.read()
+
+        preamble = '/* THIS IS AN AUTOGENERATED FILE.  DO NOT EDIT */\n\n'
+        contents = string.Template(js_template).substitute(substitutions)
+
+        with open(destination_path, 'wb') as destination:
+            destination.write(preamble + contents)
+
+        print('The database was successfully generated at ' + destination_path)