From 04df9033e6cc6ad41b57373a8f880d60bddac008 Mon Sep 17 00:00:00 2001 From: Evan Wilde Date: Tue, 20 Aug 2024 10:11:36 -0700 Subject: [PATCH] CMake: Fixing cross-compiling Swift-Foundation The macros must build for the local machine running the build, not the machine that Swift-Foundation will run on, in order for the build to be able to use the macros. To do this, the macro build must use ExternalProject, which treats the child project as an entirely independent project. One cannot introspect into the external project since it is configured at build time, rather than at configure time. This is what allows the external project to build for another platform. The expectation is that the calling project will pull the built products of the ExternalProject from the install location. EPs have an internal implicit install prefix where they can install stuff to without dirtying the building machine or installed products, so we can make use of that. In order for that to work, the products must actually get installed though, so we have to install the FoundationMacros, even when built as an executable. To support that, I've exposed an option to tell the macro build to build the macros as an executable. On the library side, I've exposed the Foundation macros as an interface library that only exposes the `-load-plugin-path` option needed for picking up the macro. Linking against this interface library will load the plugin as desired. This results in a build that - can use macros, even when cross-compiling. - does not install the macros into the installed library, only to the build directory. --- Sources/CMakeLists.txt | 25 +++++++++++++++++++++ Sources/FoundationEssentials/CMakeLists.txt | 16 +------------ Sources/FoundationMacros/CMakeLists.txt | 19 ++++++++-------- 3 files changed, 36 insertions(+), 24 deletions(-) diff --git a/Sources/CMakeLists.txt b/Sources/CMakeLists.txt index ef235c43f..451d59e3b 100644 --- a/Sources/CMakeLists.txt +++ b/Sources/CMakeLists.txt @@ -12,6 +12,31 @@ ## ##===----------------------------------------------------------------------===## +if(NOT SwiftFoudation_MACRO) + include(ExternalProject) + # The macros are required for building Swift-Foundation. Build them for the + # build machine. + ExternalProject_Add(FoundationMacros + SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/FoundationMacros" + INSTALL_DIR "${CMAKE_CURRENT_BINARY_DIR}/FoundationMacros" + CMAKE_ARGS + -DCMAKE_BUILD_TYPE=Release + -DCMAKE_Swift_COMPILER=${CMAKE_Swift_COMPILER} + -DCMAKE_INSTALL_PREFIX= + -DSwiftFoundation_BUILD_EXECUTABLE_MACROS=YES) + + ExternalProject_Get_Property(FoundationMacros INSTALL_DIR) + add_library(FoundationBuildMacros INTERFACE) + add_dependencies(FoundationBuildMacros FoundationMacros) + + if(CMAKE_HOST_WIN32) + set(_SwiftFoundation_HOST_EXECUTABLE_SUFFIX .exe) + endif() + + target_compile_options(FoundationBuildMacros INTERFACE + "$<$:SHELL:-load-plugin-executable ${INSTALL_DIR}/bin/FoundationMacros${_SwiftFoundation_HOST_EXECUTABLE_SUFFIX}#FoundationMacros>") +endif() + add_subdirectory(_FoundationCShims) add_subdirectory(FoundationEssentials) add_subdirectory(FoundationInternationalization) diff --git a/Sources/FoundationEssentials/CMakeLists.txt b/Sources/FoundationEssentials/CMakeLists.txt index 235e258a4..9cbcb222b 100644 --- a/Sources/FoundationEssentials/CMakeLists.txt +++ b/Sources/FoundationEssentials/CMakeLists.txt @@ -55,21 +55,7 @@ if(SwiftFoundation_MACRO) target_compile_options(FoundationEssentials PRIVATE "SHELL:-plugin-path ${SwiftFoundation_MACRO}") else() - message(STATUS "SwiftFoundation_MACRO not provided, building Foundation macros locally for host") - # No path to Foundation macros was provided, so we must build it ourselves - set(FoundationMacros_BuildLocalExecutable YES) - FetchContent_Declare(FoundationMacros - SOURCE_DIR ${CMAKE_SOURCE_DIR}/Sources/FoundationMacros) - FetchContent_MakeAvailable(FoundationMacros) - add_dependencies(FoundationEssentials FoundationMacros) - get_target_property(MacroDIR FoundationMacros RUNTIME_OUTPUT_DIRECTORY) - if(CMAKE_SYSTEM_NAME STREQUAL Windows) - set(MacroExecutable "${MacroDIR}/FoundationMacros.exe#FoundationMacros") - else() - set(MacroExecutable "${MacroDIR}/FoundationMacros#FoundationMacros") - endif() - target_compile_options(FoundationEssentials PUBLIC - "SHELL:$<$:-load-plugin-executable ${MacroExecutable}>") + target_link_libraries(FoundationEssentials PRIVATE FoundationBuildMacros) endif() if(CMAKE_SYSTEM_NAME STREQUAL Linux OR CMAKE_SYSTEM_NAME STREQUAL Android) diff --git a/Sources/FoundationMacros/CMakeLists.txt b/Sources/FoundationMacros/CMakeLists.txt index 31925224c..e8e7f50cc 100644 --- a/Sources/FoundationMacros/CMakeLists.txt +++ b/Sources/FoundationMacros/CMakeLists.txt @@ -26,6 +26,9 @@ endif() project(FoundationMacros LANGUAGES Swift) +option(SwiftFoundation_BUILD_EXECUTABLE_MACROS + "Build the FoundationMacros as an executable" NO) + # SwiftSyntax Dependency find_package(SwiftSyntax QUIET) if(NOT SwiftSyntax_FOUND) @@ -41,13 +44,13 @@ else() message(STATUS "SwiftSyntax_DIR provided, using swift-syntax from ${SwiftSyntax_DIR}") endif() -if(NOT FoundationMacros_BuildLocalExecutable) - add_library(FoundationMacros SHARED) - target_compile_definitions(FoundationMacros PRIVATE FOUNDATION_MACROS_LIBRARY) -else() +if(SwiftFoundation_BUILD_EXECUTABLE_MACROS) add_executable(FoundationMacros) target_link_libraries(FoundationMacros PUBLIC SwiftSyntax::SwiftCompilerPlugin) +else() + add_library(FoundationMacros SHARED) + target_compile_definitions(FoundationMacros PRIVATE FOUNDATION_MACROS_LIBRARY) endif() # Parse the module as a library, even if it's an executable, because it uses an `@main` type to define its entry point. @@ -82,8 +85,6 @@ set_target_properties(FoundationMacros PROPERTIES INSTALL_RPATH "$ORIGIN/../../../swift/${SWIFT_SYSTEM_NAME}:$ORIGIN/.." INSTALL_REMOVE_ENVIRONMENT_RPATH ON) -if(NOT FoundationMacros_BuildLocalExecutable) - install(TARGETS FoundationMacros - LIBRARY DESTINATION lib/swift/host/plugins - RUNTIME DESTINATION bin) -endif() +install(TARGETS FoundationMacros + LIBRARY DESTINATION lib/swift/host/plugins + RUNTIME DESTINATION bin)