Support building UWP with native UWP rustc target.

.cargo/config

@@ -25,8 +25,14 @@ ar = "aarch64-linux-gnu-ar"
 [target.x86_64-pc-windows-msvc]
 linker = "lld-link.exe"
 
+[target.x86_64-uwp-windows-msvc]
+linker = "lld-link.exe"
+
 [target.i686-pc-windows-msvc]
 linker = "lld-link.exe"
 
 [target.aarch64-pc-windows-msvc]
 linker = "lld-link.exe"
+
+[target.aarch64-uwp-windows-msvc]
+linker = "lld-link.exe"

Cargo.toml

@@ -29,4 +29,3 @@ opt-level = 3
 mio = { git = "https://github.com/servo/mio.git", branch = "servo" }
 rand_os = { git = "https://github.com/servo/rand", branch = "servo-rand_os-0.1.3-uwp" }
 rand_core = { git = "https://github.com/servo/rand", branch = "servo-rand_os-0.1.3-uwp" }
-

Xargo.toml

@@ -0,0 +1,7 @@
+[target.x86_64-uwp-windows-msvc.dependencies]
+std = { features = ["panic-unwind"] }
+
+# https://github.com/rust-lang/rust/issues/65313
+[target.aarch64-uwp-windows-msvc.dependencies]
+std = {}
+

etc/taskcluster/decision_task.py

@@ -390,8 +390,8 @@ def windows_arm64():
         windows_build_task("UWP dev build", arch="arm64", package=False)
         .with_treeherder("Windows arm64")
         .with_script(
-            "python mach build --dev --uwp --win-arm64",
-            "python mach package --dev --target aarch64-pc-windows-msvc --uwp=arm64",
+            "python mach build --dev --target=aarch64-uwp-windows-msvc",
+            "python mach package --dev --target aarch64-uwp-windows-msvc --uwp=arm64",
         )
         .with_artifacts(appx_artifact(debug=True))
         .find_or_create("build.windows_uwp_arm64_dev." + CONFIG.task_id())
@@ -403,8 +403,8 @@ def windows_uwp_x64():
         windows_build_task("UWP dev build", package=False)
         .with_treeherder("Windows x64")
         .with_script(
-            "mach build --dev --uwp",
-            "mach package --dev --uwp=x64",
+            "python mach build --dev --target=x86_64-uwp-windows-msvc",
+            "python mach package --dev --target=x86_64-uwp-windows-msvc --uwp=x64",
         )
         .with_artifacts(appx_artifact(debug=True))
         .find_or_create("build.windows_uwp_x64_dev." + CONFIG.task_id())
@@ -418,9 +418,9 @@ def uwp_nightly():
         .with_features("taskclusterProxy")
         .with_scopes("secrets:get:project/servo/s3-upload-credentials")
         .with_script(
-            "mach build --release --uwp",
-            "python mach build --release --uwp --win-arm64",
-            "mach package --release --uwp=x64 --uwp=arm64",
+            "python mach build --release --target=x86_64-uwp-windows-msvc",
+            "python mach build --release --target=aarch64-uwp-windows-msvc",
+            "mach package --release --target=x86_64-uwp-windows-msvc --uwp=x64 --uwp=arm64",
             "mach upload-nightly uwp --secret-from-taskcluster",
         )
         .with_artifacts(appx_artifact(debug=False))

python/servo/build_commands.py

@@ -164,17 +164,18 @@ class MachCommands(CommandBase):
     @CommandArgument('--very-verbose', '-vv',
                      action='store_true',
                      help='Print very verbose output')
-    @CommandArgument('--win-arm64', action='store_true', help="Use arm64 Windows target")
     @CommandArgument('params', nargs='...',
                      help="Command-line arguments to be passed through to Cargo")
     @CommandBase.build_like_command_arguments
     def build(self, release=False, dev=False, jobs=None, params=None,
               no_package=False, verbose=False, very_verbose=False,
-              target=None, android=False, magicleap=False, libsimpleservo=False, uwp=False,
-              features=None, win_arm64=False, **kwargs):
+              target=None, android=False, magicleap=False, libsimpleservo=False,
+              features=None, **kwargs):
         opts = params or []
         features = features or []
+
         target, android = self.pick_target_triple(target, android, magicleap)
+        uwp = target and 'uwp' in target
 
         target_path = base_path = self.get_target_dir()
         if android:
@@ -220,14 +221,8 @@ def build(self, release=False, dev=False, jobs=None, params=None,
         if very_verbose:
             opts += ["-vv"]
 
-        if win_arm64:
-            if target:
-                print("Can't specify explicit --target value with --win-arm64.")
-                sys.exit(1)
-            target = "aarch64-pc-windows-msvc"
-
         if target:
-            if self.config["tools"]["use-rustup"]:
+            if self.config["tools"]["use-rustup"] and not uwp:
                 # 'rustup target add' fails if the toolchain is not installed at all.
                 self.call_rustup_run(["rustc", "--version"])
 
@@ -265,6 +260,10 @@ def build(self, release=False, dev=False, jobs=None, params=None,
             env['PKG_CONFIG_ALLOW_CROSS'] = "1"
 
         if uwp:
+            # Ensure libstd is ready for the new UWP target.
+            check_call(["rustup", "component", "add", "rust-src"])
+            env['RUST_SYSROOT'] = path.expanduser('~\\.xargo')
+
             # Don't try and build a desktop port.
             libsimpleservo = True
 
@@ -943,7 +942,7 @@ def package_msvc_dlls(servo_exe_dir, target, vcinstalldir, vs_version):
         "msvcp140.dll",
         "vcruntime140.dll",
     ]
-    if target_arch != "aarch64" and vs_version in ("14.0", "15.0", "16.0"):
+    if target_arch != "aarch64" and "uwp" not in target and vs_version in ("14.0", "15.0", "16.0"):
         msvc_deps += ["api-ms-win-crt-runtime-l1-1-0.dll"]
 
     # Check if it's Visual C++ Build Tools or Visual Studio 2015

python/servo/command_base.py

@@ -634,6 +634,7 @@ def build_env(self, hosts_file_path=None, target=None, is_build=False, test_unit
             extra_path += [path.join(self.msvc_package_dir("llvm"), "bin")]
             extra_path += [path.join(self.msvc_package_dir("ninja"), "bin")]
             extra_path += [self.msvc_package_dir("nuget")]
+            extra_path += [path.join(self.msvc_package_dir("xargo"))]
 
             arch = (target or host_triple()).split('-')[0]
             vcpkg_arch = {
@@ -821,11 +822,6 @@ def build_like_command_arguments(decorated_function):
                 action='store_true',
                 help='Build with frame pointer enabled, used by the background hang monitor.',
             ),
-            CommandArgument(
-                '--uwp',
-                default=None,
-                action='store_true',
-                help='Build for HoloLens (x64)'),
             CommandArgument('--with-raqote', default=None, action='store_true'),
             CommandArgument('--with-layout-2020', default=None, action='store_true'),
             CommandArgument('--without-wgl', default=None, action='store_true'),
@@ -912,7 +908,10 @@ def run_cargo_build_like_command(
         assert "--features" not in cargo_args
         args += ["--features", " ".join(features)]
 
-        return self.call_rustup_run(["cargo", command] + args + cargo_args, env=env, verbose=verbose)
+        if target and 'uwp' in target:
+            return call(["xargo", command] + args + cargo_args, env=env, verbose=verbose)
+        else:
+            return self.call_rustup_run(["cargo", command] + args + cargo_args, env=env, verbose=verbose)
 
     def android_support_dir(self):
         return path.join(self.context.topdir, "support", "android")

python/servo/packages.py

@@ -11,4 +11,5 @@
     "openssl": "111.3.0+1.1.1c-vs2017-2019-09-18",
     "gstreamer-uwp": "1.16.0.5",
     "openxr-loader-uwp": "1.0",
+    "xargo": "v0.3.16",
 }

support/hololens/ServoApp/Package.appxmanifest

@@ -40,4 +40,4 @@
     <Capability Name="codeGeneration" />
     <Capability Name="privateNetworkClientServer" />
   </Capabilities>
-</Package>
+</Package>