build: add a CMake based build for Windows

Given that swift-package-manager is not currently ready for Windows,
this addition makes it possible to build for Windows.

CMakeLists.txt

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.16)
+
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules)
+
+project(swift-log
+  LANGUAGES Swift)
+
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+set(CMAKE_Swift_MODULE_DIRECTORY ${CMAKE_BINARY_DIR}/swift)
+
+include(SwiftSupport)
+
+add_subdirectory(Sources)
+
+export(EXPORT swift-log
+  NAMESPACE SwiftLog::
+  FILE swift-log-config.cmake)

Sources/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(Logging)

Sources/Logging/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_library(Logging
+  Locks.swift
+  Logging.swift
+  LogHandler.swift)
+target_compile_options(Logging PRIVATE
+  "SHELL:$<$<PLATFORM_ID:Windows>:-Xcc -D_CRT_SECURE_NO_WARNINGS>")
+set_target_properties(Logging PROPERTIES
+  INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_Swift_MODULE_DIRECTORY})
+
+
+swift_install(TARGETS Logging
+  EXPORT swift-log)

cmake/modules/SwiftSupport.cmake

@@ -0,0 +1,113 @@
+
+include(CMakeParseArguments)
+
+# Returns the architecture name in a variable
+#
+# Usage:
+#   swift_get_host_arch(result_var_name)
+#
+# Sets ${result_var_name} with the converted architecture name derived from
+# CMAKE_SYSTEM_PROCESSOR.
+function(swift_get_host_arch result_var_name)
+  if("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86_64")
+    set("${result_var_name}" "x86_64" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "aarch64")
+    set("${result_var_name}" "aarch64" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "ppc64")
+    set("${result_var_name}" "powerpc64" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "ppc64le")
+    set("${result_var_name}" "powerpc64le" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "s390x")
+    set("${result_var_name}" "s390x" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "armv6l")
+    set("${result_var_name}" "armv6" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "armv7l")
+    set("${result_var_name}" "armv7" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "armv7-a")
+    set("${result_var_name}" "armv7" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "AMD64")
+    set("${result_var_name}" "x86_64" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "IA64")
+    set("${result_var_name}" "itanium" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86")
+    set("${result_var_name}" "i686" PARENT_SCOPE)
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "i686")
+    set("${result_var_name}" "i686" PARENT_SCOPE)
+  else()
+    message(FATAL_ERROR "Unrecognized architecture on host system: ${CMAKE_SYSTEM_PROCESSOR}")
+  endif()
+endfunction()
+
+# Returns the os name in a variable
+#
+# Usage:
+#   get_swift_host_os(result_var_name)
+#
+#
+# Sets ${result_var_name} with the converted OS name derived from
+# CMAKE_SYSTEM_NAME.
+function(get_swift_host_os result_var_name)
+  if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
+    set(${result_var_name} macosx PARENT_SCOPE)
+  else()
+    string(TOLOWER ${CMAKE_SYSTEM_NAME} cmake_system_name_lc)
+    set(${result_var_name} ${cmake_system_name_lc} PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(swift_install)
+  set(options)
+  set(single_parameter_options EXPORT)
+  set(multiple_parameter_options TARGETS)
+
+  cmake_parse_arguments(SI
+    "${options}"
+    "${single_parameter_options}"
+    "${multiple_parameter_options}"
+    ${ARGN})
+
+  list(LENGTH ${SI_TARGETS} si_num_targets)
+  if(si_num_targets GREATER 1)
+    message(SEND_ERROR "swift_install only supports a single target at a time")
+  endif()
+
+  get_swift_host_os(swift_os)
+  get_target_property(type ${SI_TARGETS} TYPE)
+
+  if(type STREQUAL STATIC_LIBRARY)
+    set(swift_dir swift_static)
+  else()
+    set(swift_dir swift)
+  endif()
+
+  install(TARGETS ${SI_TARGETS}
+    EXPORT ${SI_EXPORT}
+    ARCHIVE DESTINATION lib/${swift_dir}/${swift_os}
+    LIBRARY DESTINATION lib/${swift_dir}/${swift_os}
+    RUNTIME DESTINATION bin)
+  if(type STREQUAL EXECUTABLE)
+    return()
+  endif()
+
+  swift_get_host_arch(swift_arch)
+  get_target_property(module_name ${SI_TARGETS} Swift_MODULE_NAME)
+  if(NOT module_name)
+    set(module_name ${SI_TARGETS})
+  endif()
+
+  if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
+    install(FILES
+      $<TARGET_PROPERTY:${SI_TARGETS},Swift_MODULE_DIRECTORY>/${module_name}.swiftdoc
+      DESTINATION lib/${swift_dir}/${swift_os}/${module_name}.swiftmodule
+      RENAME ${swift_arch}.swiftdoc)
+    install(FILES
+      $<TARGET_PROPERTY:${SI_TARGETS},Swift_MODULE_DIRECTORY>/${module_name}.swiftmodule
+      DESTINATION lib/${swift_dir}/${swift_os}/${module_name}.swiftmodule
+      RENAME ${swift_arch}.swiftmodule)
+  else()
+    install(FILES
+      $<TARGET_PROPERTY:${SI_TARGETS},Swift_MODULE_DIRECTORY>/${module_name}.swiftdoc
+      $<TARGET_PROPERTY:${SI_TARGETS},Swift_MODULE_DIRECTORY>/${module_name}.swiftmodule
+      DESTINATION lib/${swift_dir}/${swift_os}/${swift_arch})
+  endif()
+endfunction()