mach: introduce `BuildTarget` abstraction (#33114)

Introduce a new `BuildTarget` abstraction to centralize the code for
supporting different ways of choosing the build target (e.g --android,
--target x86_64-linux-android , --target aarch64-linux-ohos). This
is currently handled in an adhoc fashion in different commands (
mach package, install, run) leading to a proliferation of keyword
parameters for the commands and duplicated logic.

The patch introduces a new `allow_target_configuration` decorator to
do the validation and parsing of these parameters into the appropriate
`BuildTarget` subclass, which is now stored as an instance attribute
of the CommandBase class. All the code that previously relied on
`self.cross_compile_target` has been switched to use the BuildTarget.

Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>

1 files changed, 10 insertions, 8 deletions

diff --git a/python/servo/platform/macos.py b/python/servo/platform/macos.py
index de20fe35ad5..a1655dc613e 100644
--- a/python/servo/platform/macos.py
+++ b/python/servo/platform/macos.py
@@ -14,6 +14,7 @@ from typing import Optional
 
 from .. import util
 from .base import Base
+from .build_target import BuildTarget
 
 URL_BASE = "https://github.com/servo/servo-build-deps/releases/download/macOS"
 GSTREAMER_PLUGIN_VERSION = "1.22.3"
@@ -27,15 +28,15 @@ class MacOS(Base):
         super().__init__(*args, **kwargs)
         self.is_macos = True
 
-    def gstreamer_root(self, cross_compilation_target: Optional[str]) -> Optional[str]:
+    def gstreamer_root(self, target: BuildTarget) -> Optional[str]:
         # We do not support building with gstreamer while cross-compiling on MacOS.
-        if cross_compilation_target or not os.path.exists(GSTREAMER_ROOT):
+        if target.is_cross_build() or not os.path.exists(GSTREAMER_ROOT):
             return None
         return GSTREAMER_ROOT
 
-    def is_gstreamer_installed(self, cross_compilation_target: Optional[str]) -> bool:
+    def is_gstreamer_installed(self, target: BuildTarget) -> bool:
         # Servo only supports the official GStreamer distribution on MacOS.
-        return not cross_compilation_target and os.path.exists(GSTREAMER_ROOT)
+        return not target.is_cross_build() and os.path.exists(GSTREAMER_ROOT)
 
     def _platform_bootstrap(self, _force: bool) -> bool:
         installed_something = False
@@ -49,11 +50,12 @@ class MacOS(Base):
         except subprocess.CalledProcessError as e:
             print("Could not run homebrew. Is it installed?")
             raise e
-        installed_something |= self._platform_bootstrap_gstreamer(False)
+        target = BuildTarget.from_triple(None)
+        installed_something |= self._platform_bootstrap_gstreamer(target, False)
         return installed_something
 
-    def _platform_bootstrap_gstreamer(self, force: bool) -> bool:
-        if not force and self.is_gstreamer_installed(cross_compilation_target=None):
+    def _platform_bootstrap_gstreamer(self, target: BuildTarget, force: bool) -> bool:
+        if not force and self.is_gstreamer_installed(target):
             return False
 
         with tempfile.TemporaryDirectory() as temp_dir:
@@ -78,5 +80,5 @@ class MacOS(Base):
                 ]
             )
 
-            assert self.is_gstreamer_installed(cross_compilation_target=None)
+            assert self.is_gstreamer_installed(target)
             return True