Auto merge of #21809 - servo:features, r=SimonSapin

Only build ports/servo by default (except Android), add `./mach build --libsimpleservo`

Fixes #21314

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python/servo/build_commands.py

@@ -184,9 +184,14 @@ class MachCommands(CommandBase):
                      default=None,
                      action='store_true',
                      help='Enable debug assertions in release')
+    @CommandArgument('--libsimpleservo',
+                     default=None,
+                     action='store_true',
+                     help='Build the libsimpleservo library instead of the servo executable')
     def build(self, target=None, release=False, dev=False, jobs=None,
               features=None, android=None, no_package=False, verbose=False, very_verbose=False,
-              debug_mozjs=False, params=None, with_debug_assertions=False):
+              debug_mozjs=False, params=None, with_debug_assertions=False,
+              libsimpleservo=False):
 
         opts = params or []
 
@@ -254,6 +259,8 @@ class MachCommands(CommandBase):
         self.ensure_bootstrapped(target=target)
         self.ensure_clobbered()
 
+        self.add_manifest_path(opts, android, libsimpleservo)
+
         if debug_mozjs:
             features += ["debugmozjs"]
 

python/servo/command_base.py

@@ -670,9 +670,21 @@ install them, let us know by filing a bug!")
     def ports_servo_crate(self):
         return path.join(self.context.topdir, "ports", "servo")
 
+    def add_manifest_path(self, args, android=False, libsimpleservo=False):
+        if "--manifest-path" not in args:
+            if libsimpleservo or android:
+                manifest = self.ports_libsimpleservo_manifest()
+            else:
+                manifest = self.ports_servo_manifest()
+            args.append("--manifest-path")
+            args.append(manifest)
+
     def ports_servo_manifest(self):
         return path.join(self.context.topdir, "ports", "servo", "Cargo.toml")
 
+    def ports_libsimpleservo_manifest(self):
+        return path.join(self.context.topdir, "ports", "libsimpleservo", "Cargo.toml")
+
     def servo_features(self):
         """Return a list of optional features to enable for the Servo crate"""
         features = []

python/servo/devenv_commands.py

@@ -42,6 +42,8 @@ class MachCommands(CommandBase):
         if check:
             params = ['check'] + params
 
+        self.add_manifest_path(params)
+
         build_start = time()
         status = self.call_rustup_run(["cargo"] + params, env=env)
         elapsed = time() - build_start