Build macro as library instead of executable

Author: jmschonfeld

Sources/FoundationEssentials/CMakeLists.txt

@@ -20,15 +20,9 @@ include(ExternalProject)
 ExternalProject_Add(FoundationMacros
     SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../FoundationMacros"
     INSTALL_COMMAND "")
-ExternalProject_Get_Property(FoundationMacros BINARY_DIR)
-if(CMAKE_HOST_WIN32)
-    set(FoundationMacrosPath "${BINARY_DIR}/FoundationMacros.exe#FoundationMacros")
-else()
-    set(FoundationMacrosPath "${BINARY_DIR}/FoundationMacros#FoundationMacros")
-endif()
-
 add_dependencies(FoundationEssentials FoundationMacros)
 
+
 if(CMAKE_SYSTEM_NAME STREQUAL Linux OR CMAKE_SYSTEM_NAME STREQUAL Android)
     target_compile_options(FoundationEssentials PRIVATE
         "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -Xcc -Xfrontend -D_GNU_SOURCE>")
@@ -39,7 +33,6 @@ target_compile_options(FoundationEssentials PRIVATE
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend VariadicGenerics>"
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend AccessLevelOnImport>")
 target_compile_options(FoundationEssentials PRIVATE ${_SwiftFoundation_availability_macros})
-target_compile_options(FoundationEssentials PRIVATE -load-plugin-executable "${FoundationMacrosPath}")
 target_compile_options(FoundationEssentials PRIVATE -package-name "SwiftFoundation")
 
 target_link_libraries(FoundationEssentials PUBLIC

Sources/FoundationMacros/CMakeLists.txt

@@ -27,26 +27,39 @@ endif()
 project(FoundationMacros
     LANGUAGES Swift)
 
+set(FOUNDATION_MACROS_HOST_DIR "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/swift/host")
+set(FOUNDATION_MACROS_PLUGINS_DIR "${FOUNDATION_MACROS_HOST_DIR}/plugins")
+
 file(GLOB_RECURSE _FoundationMacrosSources "*.swift")
-add_executable(FoundationMacros ${_FoundationMacrosSources})
+add_library(FoundationMacros SHARED ${_FoundationMacrosSources})
+
+set_target_properties(FoundationMacros
+    PROPERTIES
+        ARCHIVE_OUTPUT_DIRECTORY "${FOUNDATION_MACROS_PLUGINS_DIR}"
+        LIBRARY_OUTPUT_DIRECTORY "${FOUNDATION_MACROS_PLUGINS_DIR}"
+)
 
 # Dependecies
 include(FetchContent)
-if (_SwiftSyntax_SourceDIR)
-    FetchContent_Declare(SwiftSyntax
-        SOURCE_DIR ${_SwiftSyntax_SourceDIR})
+if (SWIFT_BUILD_SWIFT_SYNTAX)
+    # If building in the toolchain, link against the already-built SwiftSyntax
+    target_include_directories(FoundationMacros PUBLIC "${SWIFT_HOST_LIBRARIES_DEST_DIR}")
+    target_link_directories(FoundationMacros PUBLIC "${SWIFT_HOST_LIBRARIES_DEST_DIR}")
 else()
+    # If building at desk, check out and link against the SwiftSyntax repo's targets
     FetchContent_Declare(SwiftSyntax
         GIT_REPOSITORY https://github.com/apple/swift-syntax.git
         GIT_TAG 84a4bedfd1294f6ee18e6dc9ad70df55fa6230f6)
+    FetchContent_MakeAvailable(SwiftSyntax)
+
+    target_link_libraries(FoundationMacros
+        SwiftSyntax
+        SwiftSyntaxMacros
+        SwiftCompilerPlugin)
 endif()
-FetchContent_MakeAvailable(SwiftSyntax)
 
 # Link against SwiftSyntax
 target_compile_options(FoundationMacros PRIVATE -parse-as-library)
 target_compile_options(FoundationMacros PRIVATE
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend AccessLevelOnImport>")
-target_link_libraries(FoundationMacros
-    SwiftSyntax
-    SwiftSyntaxMacros
-    SwiftCompilerPlugin)
+