build: Install libraries in an arch sub-folder

This is the proper installation scheme for Swift libraries and
prevents having to manually copy them in `build.ps1`.

Author: Steelskin

Sources/_FoundationCShims/CMakeLists.txt

@@ -43,10 +43,9 @@ install(DIRECTORY
             lib/${install_directory}/_FoundationCShims)
 
 if(NOT BUILD_SHARED_LIBS)
-    get_swift_host_os(swift_os)
     install(TARGETS _FoundationCShims
-        ARCHIVE DESTINATION lib/${install_directory}/${swift_os}
-        LIBRARY DESTINATION lib/${install_directory}/${swift_os}
+        ARCHIVE DESTINATION lib/${install_directory}/${SwiftFoundation_PLATFORM}/${SwiftFoundation_ARCH}
+        LIBRARY DESTINATION lib/${install_directory}/${SwiftFoundation_PLATFORM}/${SwiftFoundation_ARCH}
         RUNTIME DESTINATION bin)
 endif()
 

cmake/modules/SwiftFoundationSwiftSupport.cmake

@@ -1,17 +1,66 @@
-# Returns the os name in a variable
-#
-# Usage:
-#   get_swift_host_os(result_var_name)
-#
-#
-# Sets ${result_var_name} with the converted OS name derived from
-# CMAKE_SYSTEM_NAME.
-function(get_swift_host_os result_var_name)
-  set(${result_var_name} ${SWIFT_SYSTEM_NAME} PARENT_SCOPE)
-endfunction()
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the Swift open source project
+##
+## Copyright (c) 2025 Apple Inc. and the Swift project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.md for the list of Swift project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
+
+if(NOT SwiftFoundation_MODULE_TRIPLE OR NOT SwiftFoundation_ARCH OR NOT SwiftFoundation_PLATFORM)
+  # Get the target information from the Swift compiler.
+  set(module_triple_command "${CMAKE_Swift_COMPILER}" -print-target-info)
+  if(CMAKE_Swift_COMPILER_TARGET)
+    list(APPEND module_triple_command -target ${CMAKE_Swift_COMPILER_TARGET})
+  endif()
+  execute_process(COMMAND ${module_triple_command} OUTPUT_VARIABLE target_info_json)
+endif()
+
+if(NOT SwiftFoundation_MODULE_TRIPLE)
+  string(JSON module_triple GET "${target_info_json}" "target" "moduleTriple")
+  set(SwiftFoundation_MODULE_TRIPLE "${module_triple}" CACHE STRING "Triple used to install swiftmodule files")
+  mark_as_advanced(SwiftFoundation_MODULE_TRIPLE)
+  message(CONFIGURE_LOG "Swift module triple: ${module_triple}")
+endif()
+
+if(NOT SwiftFoundation_ARCH)
+  if(CMAKE_Swift_COMPILER_VERSION VERSION_EQUAL 0.0.0 OR CMAKE_Swift_COMPILER_VERSION VERSION_GREATER_EQUAL 6.2)
+    # For newer compilers, we can use the -print-target-info command to get the architecture.
+    string(JSON module_arch GET "${target_info_json}" "target" "arch")
+  else()
+    # For older compilers, extract the value from `SwiftFoundation_MODULE_TRIPLE`.
+    string(REGEX MATCH "^[^-]+" module_arch "${SwiftFoundation_MODULE_TRIPLE}")
+  endif()
+
+  set(SwiftFoundation_ARCH "${module_arch}" CACHE STRING "Arch folder name used to install libraries")
+  mark_as_advanced(SwiftFoundation_ARCH)
+  message(CONFIGURE_LOG "Swift arch: ${SwiftFoundation_ARCH}")
+endif()
+
+if(NOT SwiftFoundation_PLATFORM)
+  if(CMAKE_Swift_COMPILER_VERSION VERSION_EQUAL 0.0.0 OR CMAKE_Swift_COMPILER_VERSION VERSION_GREATER_EQUAL 6.2)
+    # For newer compilers, we can use the -print-target-info command to get the platform.
+    string(JSON swift_platform GET "${target_info_json}" "target" "platform")
+  else()
+    # For older compilers, compile the value from `CMAKE_SYSTEM_NAME`.
+    if(APPLE)
+      set(swift_platform macosx)
+    else()
+      set(swift_platform "$<LOWER_CASE:${CMAKE_SYSTEM_NAME}>")
+    endif()
+  endif()
+
+  set(SwiftFoundation_PLATFORM "${swift_platform}" CACHE STRING "Platform folder name used to install libraries")
+  mark_as_advanced(SwiftFoundation_PLATFORM)
+  message(CONFIGURE_LOG "Swift platform: ${SwiftFoundation_PLATFORM}")
+endif()
 
 function(_swift_foundation_install_target module)
-  get_swift_host_os(swift_os)
   get_target_property(type ${module} TYPE)
 
   if(type STREQUAL STATIC_LIBRARY)
@@ -21,8 +70,8 @@ function(_swift_foundation_install_target module)
   endif()
 
   install(TARGETS ${module}
-    ARCHIVE DESTINATION lib/${swift}/${swift_os}
-    LIBRARY DESTINATION lib/${swift}/${swift_os}
+    ARCHIVE DESTINATION lib/${swift}/${SwiftFoundation_PLATFORM}/${SwiftFoundation_ARCH}
+    LIBRARY DESTINATION lib/${swift}/${SwiftFoundation_PLATFORM}/${SwiftFoundation_ARCH}
     RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
   if(type STREQUAL EXECUTABLE)
     return()
@@ -33,22 +82,11 @@ function(_swift_foundation_install_target module)
     set(module_name ${module})
   endif()
 
-  if(NOT SwiftFoundation_MODULE_TRIPLE)
-    set(module_triple_command "${CMAKE_Swift_COMPILER}" -print-target-info)
-    if(CMAKE_Swift_COMPILER_TARGET)
-      list(APPEND module_triple_command -target ${CMAKE_Swift_COMPILER_TARGET})
-    endif()
-    execute_process(COMMAND ${module_triple_command} OUTPUT_VARIABLE target_info_json)
-    string(JSON module_triple GET "${target_info_json}" "target" "moduleTriple")
-    set(SwiftFoundation_MODULE_TRIPLE "${module_triple}" CACHE STRING "swift module triple used for installed swiftmodule and swiftinterface files")
-    mark_as_advanced(SwiftFoundation_MODULE_TRIPLE)
-  endif()
-
   install(FILES $<TARGET_PROPERTY:${module},Swift_MODULE_DIRECTORY>/${module_name}.swiftdoc
-    DESTINATION lib/${swift}/${swift_os}/${module_name}.swiftmodule
+    DESTINATION lib/${swift}/${SwiftFoundation_PLATFORM}/${module_name}.swiftmodule
     RENAME ${SwiftFoundation_MODULE_TRIPLE}.swiftdoc)
   install(FILES $<TARGET_PROPERTY:${module},Swift_MODULE_DIRECTORY>/${module_name}.swiftmodule
-    DESTINATION lib/${swift}/${swift_os}/${module_name}.swiftmodule
+    DESTINATION lib/${swift}/${SwiftFoundation_PLATFORM}/${module_name}.swiftmodule
     RENAME ${SwiftFoundation_MODULE_TRIPLE}.swiftmodule)
 
 endfunction()