WIP: build-script: add a flag to build libSwiftSyntaxParser only.

utils/build-script

@@ -404,6 +404,7 @@ class BuildScriptInvocation(object):
         if not args.test_watchos_host:
             self.platforms_to_skip_test_host.add(
                 StdlibDeploymentTarget.AppleWatch)
+        self.build_libparser_only = args.build_libparser_only
 
     def initialize_runtime_environment(self):
         """Change the program environment for building."""
@@ -697,7 +698,8 @@ class BuildScriptInvocation(object):
             impl_args += ["--skip-test-optimized"]
         if not args.test_optimize_for_size:
             impl_args += ["--skip-test-optimize-for-size"]
-
+        if args.build_libparser_only:
+            impl_args += ["--build-libparser-only"]
         if args.android:
             impl_args += [
                 "--android-arch", args.android_arch,

utils/build-script-impl

@@ -103,6 +103,7 @@ KNOWN_SETTINGS=(
     installable-package         ""               "the path to the archive of the installation directory"
     test-installable-package    ""               "whether to run post-packaging tests on the produced package"
     reconfigure                 ""               "force a CMake configuration run even if CMakeCache.txt already exists"
+    build-libparser-only        ""               "only build libSwiftSyntaxParser"
     skip-reconfigure            ""               "set to skip reconfigure"
     swift-primary-variant-sdk   ""               "default SDK for target binaries"
     swift-primary-variant-arch  ""               "default arch for target binaries"
@@ -1140,7 +1141,6 @@ function get_stdlib_targets_for_host() {
 # and architecture of each stdlib target -- currently it only captures the SDK.
 #
 # We turn these targets in to SWIFT_SDKS in `calculate_targets_for_host()`
-
     if [[ $(is_cross_tools_host $1) ]] ; then
         echo "$1"
     else
@@ -1824,6 +1824,16 @@ function set_swiftsyntax_build_command() {
         SWIFT_TEST="$(build_directory_bin ${LOCAL_HOST} swiftpm)/swift-test"
     fi
 
+    if [ "${BUILD_LIBPARSER_ONLY}" ]; then
+        # we don't have a compiler built so we have to use the one in the environment.
+        SWIFTC_BIN="$(xcrun_find_tool swiftc)"
+        # we don't have a swiftpm built so we have to use the one in the environment.
+        SWIFT_BUILD="$(xcrun_find_tool swift-build)"
+        SWIFT_TEST="$(xcrun_find_tool swift-test)"
+    else
+        SWIFTC_BIN="$(build_directory_bin ${LOCAL_HOST} swift)/swiftc"
+    fi
+
     swiftsyntax_build_command=("${SWIFTSYNTAX_SOURCE_DIR}/build-script.py")
     # Add --release if we have to build in release mode.
     if [[ $(is_cmake_release_build_type "${SWIFTSYNTAX_BUILD_TYPE}") ]] ; then
@@ -1836,7 +1846,7 @@ function set_swiftsyntax_build_command() {
         --build-dir="${build_dir}"
         --swift-build-exec="${SWIFT_BUILD}"
         --swift-test-exec="${SWIFT_TEST}"
-        --swiftc-exec="$(build_directory_bin ${LOCAL_HOST} swift)/swiftc"
+        --swiftc-exec="${SWIFTC_BIN}"
         --syntax-parser-header-dir="${SWIFT_SOURCE_DIR}/include/swift-c/SyntaxParser"
         --syntax-parser-lib-dir="$(build_directory ${host} swift)/lib"
         --swift-syntax-test-exec="$(build_directory_bin ${LOCAL_HOST} swift)/swift-syntax-test"
@@ -2388,7 +2398,9 @@ for host in "${ALL_HOSTS[@]}"; do
                     build_targets=("${build_targets[@]}"
                                    "${SWIFT_BENCHMARK_TARGETS[@]}")
                 fi
-
+                if [ "${BUILD_LIBPARSER_ONLY}" ]; then
+                    build_targets=(libSwiftSyntaxParser)
+                fi
                 skip_build=${SKIP_BUILD_SWIFT}
                 ;;
             lldb)

utils/build_swift/driver_arguments.py

@@ -542,6 +542,9 @@ def create_argument_parser():
     option('--build-ninja', toggle_true,
            help='build the Ninja tool')
 
+    option(['--build-libparser-only'], store_true('build_libparser_only'),
+           help='build only libParser for SwiftSyntax')
+
     # -------------------------------------------------------------------------
     in_group('Extra actions to perform before or in addition to building')
 

utils/build_swift/tests/expected_options.py

@@ -82,6 +82,7 @@
     'build_swift_stdlib_unittest_extra': False,
     'build_swiftpm': False,
     'build_swiftsyntax': False,
+    'build_libparser_only': False,
     'build_skstresstester': False,
     'build_swiftevolve': False,
     'build_tvos': True,
@@ -400,6 +401,7 @@ class IgnoreOption(_BaseOption):
     SetTrueOption('--skip-build'),
     SetTrueOption('--swiftpm', dest='build_swiftpm'),
     SetTrueOption('--swiftsyntax', dest='build_swiftsyntax'),
+    SetTrueOption('--build-libparser-only', dest='build_libparser_only'),
     SetTrueOption('--skstresstester', dest='build_skstresstester'),
     SetTrueOption('--swiftevolve', dest='build_swiftevolve'),
     SetTrueOption('-B', dest='benchmark'),

utils/build_swift/tests/test_driver_arguments.py

@@ -690,6 +690,12 @@ def test_implied_defaults_host_test(self):
             self.assertFalse(namespace.test_tvos_host)
             self.assertFalse(namespace.test_watchos_host)
             self.assertFalse(namespace.test_android_host)
+            self.assertFalse(namespace.build_libparser_only)
+
+    def test_build_lib_swiftsyntaxparser_only(self):
+        with self.assertNotRaises(ParserError):
+            namespace = self.parse_default_args(['--build-libparser-only'])
+            self.assertTrue(namespace.build_libparser_only)
 
 
 if __name__ == '__main__':