Replace script_plugins with a clippy like rustc driver (named crown) (#30508)

* Remove script_plugins

* Use crown instead of script_plugins

* crown_is_not_used

* Use crown in command base

* bootstrap crown

* tidy happy

* disable sccache

* Bring crown in tree

* Install crown from tree

* fix windows ci

* fix warning

* fix mac

libscript_plugins.dylib is not available anymore

* Update components/script/lib.rs

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

* Update for nightly-2023-03-18

Mostly just based off https://github.com/servo/servo/pull/30630

* Always install crown

it's slow only when there is new version

* Run crown test with `mach test-unit`

* Small fixups; better trace_in_no_trace tests

* Better doc

* crown in config.toml

* Fix tidy for real

* no sccache on rustc_wrapper

* document rustc overrides

* fixup of compiletest

* Make a few minor comment adjustments

* Fix a typo in python/servo/platform/base.py

Co-authored-by: Samson <16504129+sagudev@users.noreply.github.com>

* Proper test types

* Ignore tidy on crown/tests

---------

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

python/servo/platform/base.py

@@ -97,6 +97,7 @@ class Base:
     def bootstrap(self, force: bool):
         installed_something = self._platform_bootstrap(force)
         installed_something |= self.install_taplo(force)
+        installed_something |= self.install_crown(force)
         if not installed_something:
             print("Dependencies were already installed!")
 
@@ -110,6 +111,18 @@ class Base:
 
         return True
 
+    def install_crown(self, force: bool) -> bool:
+        # We need to override the rustc set in cargo/config.toml because crown
+        # may not be installed yet.
+        env = dict(os.environ)
+        env["CARGO_BUILD_RUSTC"] = "rustc"
+
+        if subprocess.call(["cargo", "install", "--path", "support/crown"],
+                           stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=env) != 0:
+            raise EnvironmentError("Installation of crown failed.")
+
+        return True
+
     def passive_bootstrap(self) -> bool:
         """A bootstrap method that is called without explicitly invoking `./mach bootstrap`
            but that is executed in the process of other `./mach` commands. This should be

python/servo/testing_commands.py

@@ -218,6 +218,7 @@ class MachCommands(CommandBase):
             "script_traits",
             "servo_config",
             "servo_remutex",
+            "crown",
         ]
         if not packages:
             packages = set(os.listdir(path.join(self.context.topdir, "tests", "unit"))) - set(['.DS_Store'])

python/tidy/tests/ban-domrefcell.rs

@@ -2,9 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-#![feature(plugin)]
-#![plugin(script_plugins)]
-
 extern crate script;
 
 use script::test::Dom;

python/tidy/tests/ban.rs

@@ -2,9 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-#![feature(plugin)]
-#![plugin(script_plugins)]
-
 extern crate js;
 
 use js::jsval::JSVal;