build: simplify the unified build configuration

Conditionalise the inclusion of directory paths. If the include
directory is empty, CMake will raise an error. This allows us to disable
larger portions of the Swift build to speed up some of the build tool
configuration phase and prepares for consuming CMark GFM as a CMake
project.

Author: compnerd

cmake/modules/SwiftSharedCMakeConfig.cmake

@@ -268,16 +268,13 @@ endmacro()
 #     cmake variables.
 macro(swift_common_unified_build_config product)
   set(${product}_PATH_TO_CLANG_BUILD "${CMAKE_BINARY_DIR}")
-  set(CLANG_MAIN_INCLUDE_DIR "${LLVM_EXTERNAL_CLANG_SOURCE_DIR}/include")
-  set(CLANG_BUILD_INCLUDE_DIR "${CMAKE_BINARY_DIR}/tools/clang/include")
   set(${product}_NATIVE_LLVM_TOOLS_PATH "${CMAKE_BINARY_DIR}/bin")
   set(${product}_NATIVE_CLANG_TOOLS_PATH "${CMAKE_BINARY_DIR}/bin")
   set(LLVM_PACKAGE_VERSION ${PACKAGE_VERSION})
   set(LLVM_CMAKE_DIR "${CMAKE_SOURCE_DIR}/cmake/modules")
-  set(CLANG_INCLUDE_DIRS 
-    "${CLANG_MAIN_INCLUDE_DIR}"
-    "${CLANG_BUILD_INCLUDE_DIR}"
-  )
+
+  include_directories(${LLVM_EXTERNAL_CLANG_SOURCE_DIR}/include
+    ${CMAKE_BINARY_DIR}/tools/clang/include)
 
   # If cmark was checked out into tools/cmark, expect to build it as
   # part of the unified build.
@@ -293,16 +290,10 @@ macro(swift_common_unified_build_config product)
     get_filename_component(CMARK_LIBRARY_DIR "${${product}_CMARK_LIBRARY_DIR}"
       ABSOLUTE)
 
-    set(CMARK_BUILD_INCLUDE_DIR "${PATH_TO_CMARK_BUILD}/src")
-    set(CMARK_MAIN_INCLUDE_DIR "${CMARK_MAIN_SRC_DIR}/src/include")
+    include_directories(${PATH_TO_CMARK_BUILD}/src
+      ${CMARK_MAIN_SRC_DIR}/src/include)
   endif()
 
-  include_directories(
-      "${CLANG_BUILD_INCLUDE_DIR}"
-      "${CLANG_MAIN_INCLUDE_DIR}"
-      "${CMARK_MAIN_INCLUDE_DIR}"
-      "${CMARK_BUILD_INCLUDE_DIR}")
-
   include(AddSwiftTableGen) # This imports TableGen from LLVM.
 
   check_cxx_compiler_flag("-Werror -Wnested-anon-types" CXX_SUPPORTS_NO_NESTED_ANON_TYPES_FLAG)

utils/build.ps1

@@ -857,21 +857,22 @@ function Build-BuildTools($Arch) {
       LLVM_ENABLE_LIBEDIT = "NO";
       LLVM_ENABLE_LIBXML2 = "NO";
       LLVM_ENABLE_PROJECTS = "clang;clang-tools-extra;lldb";
-      LLVM_EXTERNAL_PROJECTS = "cmark;swift";
-      LLVM_EXTERNAL_CMARK_SOURCE_DIR = "$SourceCache\cmark";
+      LLVM_EXTERNAL_PROJECTS = "swift";
       LLVM_EXTERNAL_SWIFT_SOURCE_DIR = "$SourceCache\swift";
       SWIFT_BUILD_DYNAMIC_SDK_OVERLAY = "NO";
       SWIFT_BUILD_DYNAMIC_STDLIB = "NO";
+      SWIFT_BUILD_HOST_DISPATCH = "NO";
       SWIFT_BUILD_LIBEXEC = "NO";
+      SWIFT_BUILD_REGEX_PARSER_IN_COMPILER = "NO";
       SWIFT_BUILD_REMOTE_MIRROR = "NO";
       SWIFT_BUILD_SOURCEKIT = "NO";
       SWIFT_BUILD_STATIC_SDK_OVERLAY = "NO";
       SWIFT_BUILD_STATIC_STDLIB = "NO";
+      SWIFT_BUILD_SWIFT_SYNTAX = "NO";
+      SWIFT_ENABLE_DISPATCH = "NO";
       SWIFT_INCLUDE_APINOTES = "NO";
       SWIFT_INCLUDE_DOCS = "NO";
       SWIFT_INCLUDE_TESTS = "NO";
-      SWIFT_PATH_TO_LIBDISPATCH_SOURCE = "$SourceCache\swift-corelibs-libdispatch";
-      SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE = "$SourceCache\swift-syntax";
     }
 }