build: Build Swift SDK for WebAssembly

This change adds a new product, WasmSwiftSDK, to build the Swift SDK for
WebAssembly. The product is built using the swift-sdk-generator package
and takes just built WebAssembly stdlib, clang runtime libraries,
and wasi-sysroot as input, and produces a Swift SDK artifactbundle under
swift-sdk-generator/Bundles.

Author: kateinoigakukun

utils/swift_build_support/swift_build_support/build_script_invocation.py

@@ -686,6 +686,8 @@ def compute_product_pipelines(self):
                             is_enabled=self.args.build_wasmstdlib)
         builder.add_product(products.WasmThreadsStdlib,
                             is_enabled=self.args.build_wasmstdlib)
+        builder.add_product(products.WasmSwiftSDK,
+                            is_enabled=self.args.build_wasmstdlib)
 
         # Keep SwiftDriver at last.
         # swift-driver's integration with the build scripts is not fully

utils/swift_build_support/swift_build_support/products/__init__.py

@@ -39,7 +39,7 @@
 from .tsan_libdispatch import TSanLibDispatch
 from .wasisysroot import WASILibc, WasmLLVMRuntimeLibs, WasmThreadsLLVMRuntimeLibs
 from .wasmkit import WasmKit
-from .wasmstdlib import WasmStdlib, WasmThreadsStdlib
+from .wasmstdlib import WasmStdlib, WasmSwiftSDK, WasmThreadsStdlib
 from .xctest import XCTest
 from .zlib import Zlib
 
@@ -79,4 +79,5 @@
     'WasmStdlib',
     'WasmThreadsLLVMRuntimeLibs',
     'WasmThreadsStdlib',
+    'WasmSwiftSDK',
 ]

utils/swift_build_support/swift_build_support/products/wasmstdlib.py

@@ -14,9 +14,11 @@
 
 from . import cmake_product
 from . import llvm
+from . import product
 from . import swift
 from . import wasisysroot
 from . import wasmkit
+from .. import shell
 
 
 class WasmStdlib(cmake_product.CMakeProduct):
@@ -42,6 +44,7 @@ def build(self, host_target):
         self._build(host_target, 'wasm32-wasi')
 
     def _build(self, host_target, target_triple):
+        self.cmake_options.define('CMAKE_INSTALL_PREFIX:PATH', 'usr')
         self.cmake_options.define('CMAKE_BUILD_TYPE:STRING', self._build_variant)
         self.cmake_options.define(
             'SWIFT_STDLIB_BUILD_TYPE:STRING', self._build_variant)
@@ -206,3 +209,94 @@ def add_extra_cmake_options(self):
                                   '-Xcc;-mthread-model;-Xcc;posix;'
                                   '-Xcc;-pthread;-Xcc;-ftls-model=local-exec')
         self.cmake_options.define('SWIFT_ENABLE_WASI_THREADS:BOOL', 'TRUE')
+
+
+class WasmSwiftSDK(product.Product):
+    @classmethod
+    def product_source_name(cls):
+        return "swift-sdk-generator"
+
+    @classmethod
+    def is_build_script_impl_product(cls):
+        return False
+
+    @classmethod
+    def is_before_build_script_impl_product(cls):
+        return False
+
+    def should_build(self, host_target):
+        return self.args.build_wasmstdlib
+
+    def should_test(self, host_target):
+        return False
+
+    def _target_package_path(self, target_triple):
+        return os.path.join(self.build_dir, 'Toolchains', target_triple)
+
+    def _build_target_package(self, target_triple,
+                              stdlib_build_path, llvm_runtime_libs_build_path):
+
+        dest_dir = self._target_package_path(target_triple)
+        shell.rmtree(dest_dir)
+        shell.makedirs(dest_dir)
+
+        # Build toolchain package for standalone stdlib
+        with shell.pushd(stdlib_build_path):
+            shell.call([self.toolchain.cmake, '--install', '.'],
+                       env={'DESTDIR': dest_dir})
+
+        # Copy LLVM runtime libraries
+        with shell.pushd(llvm_runtime_libs_build_path):
+            clang_dest_dir = os.path.join(dest_dir, 'usr/lib/swift_static/clang')
+            shell.call([self.toolchain.cmake, '--install', '.',
+                        '--component', 'clang_rt.builtins-wasm32'],
+                       env={'DESTDIR': clang_dest_dir})
+        return dest_dir
+
+    def build(self, host_target):
+        build_root = os.path.dirname(self.build_dir)
+        llvm_runtime_libs_build_path = os.path.join(
+            build_root, '%s-%s' % ('wasmllvmruntimelibs', host_target))
+
+        target_packages = []
+        for target_triple, build_basename in [
+            ('wasm32-unknown-wasi', 'wasmstdlib'),
+            # TODO: Enable threads stdlib once sdk-generator supports multi-target SDK
+            # ('wasm32-unknown-wasip1-threads', 'wasmthreadsstdlib'),
+        ]:
+            stdlib_build_path = os.path.join(
+                build_root, '%s-%s' % (build_basename, host_target))
+            package_path = self._build_target_package(
+                target_triple, stdlib_build_path, llvm_runtime_libs_build_path)
+            target_packages.append((target_triple, package_path))
+
+        swiftc_path = os.path.abspath(self.toolchain.swiftc)
+        toolchain_path = os.path.dirname(os.path.dirname(swiftc_path))
+        swift_run = os.path.join(toolchain_path, 'bin', 'swift-run')
+
+        swift_version = os.environ.get('TOOLCHAIN_VERSION',
+                                       'swift-DEVELOPMENT-SNAPSHOT').lstrip('swift-')
+        run_args = [
+            swift_run,
+            '--package-path', self.source_dir,
+            '--build-path', self.build_dir,
+            'swift-sdk-generator',
+            'make-wasm-sdk',
+            '--wasi-sysroot', wasisysroot.WASILibc.sysroot_install_path(build_root),
+            '--swift-version', swift_version,
+        ]
+        for target_triple, package_path in target_packages:
+            run_args.extend(['--target', target_triple])
+            run_args.extend(['--target-swift-package-path', package_path])
+
+        shell.call(run_args)
+
+    def test(self, host_target):
+        pass
+
+    def should_install(self, host_target):
+        return False
+
+    @classmethod
+    def get_dependencies(cls):
+        return [WasmStdlib, WasmThreadsStdlib]

utils/update_checkout/update-checkout-config.json

@@ -83,6 +83,8 @@
             "remote": { "id": "apple/swift-nio-ssl" } },
         "swift-experimental-string-processing": {
             "remote": { "id": "apple/swift-experimental-string-processing" } },
+        "swift-sdk-generator": {
+            "remote": { "id": "apple/swift-sdk-generator" } },
         "swift-llvm-bindings": {
             "remote": { "id": "apple/swift-llvm-bindings" } },
         "llvm-project": {
@@ -149,6 +151,7 @@
                 "swift-markdown": "main",
                 "swift-nio": "2.31.2",
                 "swift-experimental-string-processing": "swift/main",
+                "swift-sdk-generator": "main",
                 "wasi-libc": "wasi-sdk-20",
                 "wasmkit": "0.0.3",
                 "curl": "curl-8_5_0",