Allow `./mach build` to enable Servo's headless mode

python/servo/build_commands.py

@@ -29,6 +29,16 @@ def is_headless_build():
     return int(os.getenv('SERVO_HEADLESS', 0)) == 1
 
 
+def headless_supported():
+    supported = sys.platform.startswith("linux")
+
+    if not supported:
+        print("Headless mode (OSMesa) is not supported on your platform.")
+        print("Building without headless mode.")
+
+    return supported
+
+
 def notify_linux(title, text):
     try:
         import dbus
@@ -134,6 +144,10 @@ class MachCommands(CommandBase):
     @CommandArgument('--dev', '-d',
                      action='store_true',
                      help='Build in development mode')
+    @CommandArgument('--headless',
+                     default=None,
+                     action='store_true',
+                     help='Enable headless mode (OSMesa)')
     @CommandArgument('--jobs', '-j',
                      default=None,
                      help='Number of jobs to run in parallel')
@@ -155,7 +169,7 @@ class MachCommands(CommandBase):
     @CommandArgument('params', nargs='...',
                      help="Command-line arguments to be passed through to Cargo")
     def build(self, target=None, release=False, dev=False, jobs=None,
-              features=None, android=None, verbose=False, debug_mozjs=False, params=None):
+              features=None, headless=False, android=None, verbose=False, debug_mozjs=False, params=None):
         if android is None:
             android = self.config["build"]["android"]
         features = features or []
@@ -203,7 +217,7 @@ def build(self, target=None, release=False, dev=False, jobs=None,
         if debug_mozjs or self.config["build"]["debug-mozjs"]:
             features += ["script/debugmozjs"]
 
-        if is_headless_build():
+        if (headless or is_headless_build()) and headless_supported():
             opts += ["--no-default-features"]
             features += ["headless"]
 
@@ -324,15 +338,19 @@ def build_gonk(self, jobs=None, verbose=False, release=False):
     @Command('build-tests',
              description='Build the Servo test suites',
              category='build')
+    @CommandArgument('--headless',
+                     default=None,
+                     action='store_true',
+                     help='Enable headless mode (OSMesa)')
     @CommandArgument('--jobs', '-j',
                      default=None,
                      help='Number of jobs to run in parallel')
     @CommandArgument('--release', default=False, action="store_true",
                      help="Build tests with release mode")
-    def build_tests(self, jobs=None, verbose=False, release=False):
+    def build_tests(self, headless=False, jobs=None, verbose=False, release=False):
         self.ensure_bootstrapped()
         args = ["cargo", "test", "--no-run"]
-        if is_headless_build():
+        if (headless or is_headless_build()) and headless_supported():
             args += ["--no-default-features", "--features", "headless"]
         if release:
             args += ["--release"]