[CMake] Update for review comments

(cherry picked from commit 9017ef5)

Author: rintaro

CMakeLists.txt

@@ -960,7 +960,9 @@ if(SWIFT_PATH_TO_EARLYSWIFTSYNTAX_BUILD_DIR)
     include(${SWIFT_PATH_TO_EARLYSWIFTSYNTAX_TARGETS})
 
     if(SWIFT_HOST_VARIANT_SDK STREQUAL "LINUX" AND NOT BOOTSTRAPPING_MODE STREQUAL "HOSTTOOLS")
-      message(FATAL_ERROR "Only BOOTSTRAPPING=HOSTTOOLS is supported in Linux when Swift parser integration is enabled")
+      # Only "HOSTTOOLS" is supported in Linux when Swift parser integration is enabled.
+      message(WARNING "Force setting BOOTSTRAPPING=HOSTTOOLS because Swift parser integration is enabled")
+      set(BOOTSTRAPPING_MODE "HOSTTOOLS")
     endif()
   endif()
 endif()

cmake/modules/AddPureSwift.cmake

@@ -67,21 +67,20 @@ endfunction()
 
 function(_set_pure_swift_link_flags name relpath_to_lib_dir)
   if(SWIFT_HOST_VARIANT_SDK STREQUAL "LINUX")
-    # Don't add builder's stdlib RPATH automatically, because we want to *de-prioritize* it.
+    # Don't add builder's stdlib RPATH automatically.
     target_compile_options(${name} PRIVATE
       $<$<COMPILE_LANGUAGE:Swift>:-no-toolchain-stdlib-rpath>
     )
 
-    get_filename_component(swift_bin_dir ${CMAKE_Swift_COMPILER} DIRECTORY)
-    get_filename_component(swift_dir ${swift_bin_dir} DIRECTORY)
-    set(host_lib_dir "${swift_dir}/lib/swift/${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}")
-
     set_property(TARGET ${name}
       APPEND PROPERTY INSTALL_RPATH
-        # At runtime, use swiftCore in the current toolchain.
+        # At runtime, use swiftCore in the current just-built toolchain.
+        # NOTE: This relies on the ABI being the same as the builder.
         "$ORIGIN/${relpath_to_lib_dir}/swift/${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}"
     )
-
+    # NOTE: At this point we don't have any pure swift executables/shared
+    # libraries required for building runtime/stdlib. So we don't need to add
+    # RPATH to the builder's runtime.
   endif()
 endfunction()
 

tools/driver/CMakeLists.txt

@@ -26,7 +26,6 @@ if(BOOTSTRAPPING_MODE MATCHES "BOOTSTRAPPING.*")
     HAS_SWIFT_MODULES
     BOOTSTRAPPING 0
     THINLTO_LD64_ADD_FLTO_CODEGEN_ONLY
-    REQUIRED_FOR_MINIMAL_COMPILER
   )
   target_link_libraries(swift-frontend-bootstrapping0
                         PRIVATE
@@ -48,7 +47,6 @@ if(BOOTSTRAPPING_MODE MATCHES "BOOTSTRAPPING.*")
     HAS_SWIFT_MODULES
     BOOTSTRAPPING 1
     THINLTO_LD64_ADD_FLTO_CODEGEN_ONLY
-    REQUIRED_FOR_MINIMAL_COMPILER
   )
   target_link_libraries(swift-frontend-bootstrapping1
                         PRIVATE

utils/build-presets.ini

@@ -845,6 +845,7 @@ install-lldb
 install-llbuild
 install-swiftpm
 install-swift-driver
+install-swiftsyntax
 install-xctest
 install-libicu
 install-prefix=/usr
@@ -875,8 +876,6 @@ installable-package=%(installable_package)s
 # in Linux CI bots
 relocate-xdg-cache-home-under-build-subdir
 
-# Linux only support 'hosttools' with early-swiftsyntax.
-bootstrapping=hosttools
 
 [preset: buildbot_linux_base]
 mixin-preset=

utils/swift_build_support/swift_build_support/products/earlyswiftsyntax.py

@@ -79,4 +79,4 @@ def should_install(self, host_target):
 
     def install(self, host_target):
         # No-op.
-        None
+        pass