Revert "Revert "[build-script] Move --native-{clang,llvm,swift}-tools-path flags into the Python build-script""

Also, fix two places where the LLVM path was wrongly employed to set up clang,
and use the Swift path in install_toolchain_path().

Author: finagolfin

stdlib/CMakeLists.txt

@@ -112,11 +112,11 @@ else()
   # If we use Clang-cl or MSVC, CMake provides default compiler and linker flags that are incompatible
   # with the frontend of Clang or Clang++.
   if(SWIFT_COMPILER_IS_MSVC_LIKE)
-    set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang-cl")
-    set(CMAKE_C_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang-cl")
+    set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang-cl")
+    set(CMAKE_C_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang-cl")
   else()
-    set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang++")
-    set(CMAKE_C_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang")
+    set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang++")
+    set(CMAKE_C_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang")
   endif()
 
   if(CMAKE_C_COMPILER_LAUNCHER MATCHES ".*distcc")

unittests/runtime/CMakeLists.txt

@@ -13,11 +13,11 @@ if(("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "${SWIFT_PRIMARY_VARIANT_SDK}") AND
     # If we use Clang-cl or MSVC, CMake provides default compiler and linker flags that are incompatible
     # with the frontend of Clang or Clang++.
     if(SWIFT_COMPILER_IS_MSVC_LIKE)
-      set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang-cl")
-      set(CMAKE_C_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang-cl")
+      set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang-cl")
+      set(CMAKE_C_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang-cl")
     else()
-      set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang++")
-      set(CMAKE_C_COMPILER "${SWIFT_NATIVE_LLVM_TOOLS_PATH}/clang")
+      set(CMAKE_CXX_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang++")
+      set(CMAKE_C_COMPILER "${SWIFT_NATIVE_CLANG_TOOLS_PATH}/clang")
     endif()
 
     if(CMAKE_C_COMPILER_LAUNCHER MATCHES ".*distcc")

utils/build-script

@@ -707,6 +707,18 @@ class BuildScriptInvocation(object):
             impl_args += [
                 "--host-libtool", toolchain.libtool,
             ]
+        if args.native_clang_tools_path is not None:
+            impl_args += [
+                "--native-clang-tools-path=%s" % args.native_clang_tools_path
+            ]
+        if args.native_llvm_tools_path is not None:
+            impl_args += [
+                "--native-llvm-tools-path=%s" % args.native_llvm_tools_path
+            ]
+        if args.native_swift_tools_path is not None:
+            impl_args += [
+                "--native-swift-tools-path=%s" % args.native_swift_tools_path
+            ]
 
         # If we have extra_swift_args, combine all of them together and then
         # add them as one command.

utils/build_swift/build_swift/driver_arguments.py

@@ -374,6 +374,15 @@ def create_argument_parser():
     option('--host-cxx', store_path(executable=True),
            help='the absolute path to CXX, the "clang++" compiler for the '
                 'host platform. Default is auto detected.')
+    option('--native-swift-tools-path', store_path,
+           help='the path to a directory that contains prebuilt Swift tools '
+                'that are executable on the host platform')
+    option('--native-clang-tools-path', store_path,
+           help='the path to a directory that contains prebuilt Clang tools '
+                'that are executable on the host platform')
+    option('--native-llvm-tools-path', store_path,
+           help='the path to a directory that contains prebuilt LLVM tools '
+                'that are executable on the host platform')
     option('--cmake-c-launcher', store_path(executable=True),
            default=os.environ.get('C_COMPILER_LAUNCHER', None),
            help='the absolute path to set CMAKE_C_COMPILER_LAUNCHER')

utils/build_swift/tests/expected_options.py

@@ -189,6 +189,9 @@
     'lto_type': None,
     'maccatalyst': False,
     'maccatalyst_ios_tests': False,
+    'native_clang_tools_path': None,
+    'native_llvm_tools_path': None,
+    'native_swift_tools_path': None,
     'dump_config': False,
     'show_sdks': False,
     'skip_build': False,
@@ -653,6 +656,9 @@ class BuildScriptImplOption(_BaseOption):
     PathOption('--install-symroot'),
     PathOption('--install-destdir'),
     EnableOption('--install-all'),
+    PathOption('--native-clang-tools-path'),
+    PathOption('--native-llvm-tools-path'),
+    PathOption('--native-swift-tools-path'),
     PathOption('--symbols-package'),
     PathOption('--cmake-c-launcher'),
     PathOption('--cmake-cxx-launcher'),

utils/swift_build_support/swift_build_support/products/product.py

@@ -167,8 +167,11 @@ def install_toolchain_path(self, host_target):
         """toolchain_path() -> string
 
         Returns the path to the toolchain that is being created as part of this
-        build.
+        build, or to a native prebuilt toolchain that was passed in.
         """
+        if self.args.native_swift_tools_path is not None:
+            return os.path.split(self.args.native_swift_tools_path)[0]
+
         install_destdir = self.args.install_destdir
         if self.args.cross_compile_hosts:
             build_root = os.path.dirname(self.build_dir)