1 files changed, 121 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 0000000000..7a41ea49b2
--- /dev/null
+++ b/devtools/shared/css/generated/mach_commands.py
@@ -0,0 +1,121 @@
+# 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 InspectorUtils to query the CSS properties used by the browser.
+This information is used to generate the properties-db.js file.
+"""
+
+import json
+import logging
+import os
+import runpy
+import sys
+import string
+import subprocess
+from mozbuild import shellutil
+from mozbuild.base import (
+    MozbuildObject,
+    BinaryNotFoundException,
+)
+from mach.decorators import (
+    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=(",", ": "))
+
+
+@Command(
+    "devtools-css-db",
+    category="post-build",
+    description="Rebuild the devtool's static css properties database.",
+)
+def generate_css_db(command_context):
+    """Generate the static css properties database for devtools and write it to file."""
+
+    print("Re-generating the css properties database...")
+    db = get_properties_db_from_xpcshell(command_context)
+    if not db:
+        return 1
+
+    output_template(
+        command_context,
+        {
+            "preferences": stringify(db["preferences"]),
+            "cssProperties": stringify(db["cssProperties"]),
+            "pseudoElements": stringify(db["pseudoElements"]),
+        },
+    )
+
+
+def get_properties_db_from_xpcshell(command_context):
+    """Generate the static css properties db for devtools from an xpcshell script."""
+    build = MozbuildObject.from_environment()
+
+    # Get the paths
+    script_path = resolve_path(
+        command_context.topsrcdir,
+        "devtools/shared/css/generated/generate-properties-db.js",
+    )
+    gre_path = resolve_path(command_context.topobjdir, "dist/bin")
+    browser_path = resolve_path(command_context.topobjdir, "dist/bin/browser")
+    try:
+        xpcshell_path = build.get_binary_path(what="xpcshell")
+    except BinaryNotFoundException as e:
+        command_context.log(
+            logging.ERROR, "devtools-css-db", {"error": str(e)}, "ERROR: {error}"
+        )
+        command_context.log(
+            logging.INFO, "devtools-css-db", {"help": e.help()}, "{help}"
+        )
+        return None
+
+    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.decode().split("DEVTOOLS_CSS_DB_DELIMITER")[1]
+
+    return json.loads(contents)
+
+
+def output_template(command_context, substitutions):
+    """Output a the properties-db.js from a template."""
+    js_template_path = resolve_path(
+        command_context.topsrcdir,
+        "devtools/shared/css/generated/properties-db.js.in",
+    )
+    destination_path = resolve_path(
+        command_context.topsrcdir, "devtools/shared/css/generated/properties-db.js"
+    )
+
+    with open(js_template_path, "rb") as handle:
+        js_template = handle.read().decode()
+
+    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.encode() + contents.encode())
+
+    print("The database was successfully generated at " + destination_path)