Add rudimentary support for the Apple Swift language with Xcode

Allow the `Swift` language to be enabled with the Xcode generator for
Xcode >= 6.1.  Reject it on other generators and with older Xcode
versions.  Since Apple is the only vendor implementing the language
right now, the compiler id can be just `Apple`.

5 files changed, 115 insertions, 0 deletions

diff --git a/Modules/CMakeDetermineSwiftCompiler.cmake b/Modules/CMakeDetermineSwiftCompiler.cmake
new file mode 100644
index 0000000000..bff1ae9cd0
--- /dev/null
+++ b/Modules/CMakeDetermineSwiftCompiler.cmake
@@ -0,0 +1,53 @@
+
+#=============================================================================
+# Copyright 2002-2015 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+include(${CMAKE_ROOT}/Modules/CMakeDetermineCompiler.cmake)
+
+if("${CMAKE_GENERATOR}" STREQUAL "Xcode")
+  if(XCODE_VERSION VERSION_LESS 6.1)
+    message(FATAL_ERROR "Swift language not supported by Xcode ${XCODE_VERSION}")
+  endif()
+  set(CMAKE_Swift_COMPILER_XCODE_TYPE sourcecode.swift)
+  _cmake_find_compiler_path(Swift)
+else()
+  message(FATAL_ERROR "Swift language not supported by \"${CMAKE_GENERATOR}\" generator")
+endif()
+
+# Build a small source file to identify the compiler.
+if(NOT CMAKE_Swift_COMPILER_ID_RUN)
+  set(CMAKE_Swift_COMPILER_ID_RUN 1)
+
+  list(APPEND CMAKE_Swift_COMPILER_ID_MATCH_VENDORS Apple)
+  set(CMAKE_Swift_COMPILER_ID_MATCH_VENDOR_REGEX_Apple "com.apple.xcode.tools.swift.compiler")
+
+  set(CMAKE_Swift_COMPILER_ID_TOOL_MATCH_REGEX "\nCompileSwiftSources[^\n]*(\n[ \t]+[^\n]*)*\n[ \t]+([^ \t\r\n]+)[^\r\n]* -c[^\r\n]*CompilerIdSwift/CompilerId/main.swift")
+  set(CMAKE_Swift_COMPILER_ID_TOOL_MATCH_INDEX 2)
+
+  # Try to identify the compiler.
+  set(CMAKE_Swift_COMPILER_ID)
+  include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
+  CMAKE_DETERMINE_COMPILER_ID(Swift "" CompilerId/main.swift)
+endif()
+
+if (NOT _CMAKE_TOOLCHAIN_LOCATION)
+  get_filename_component(_CMAKE_TOOLCHAIN_LOCATION "${CMAKE_Swift_COMPILER}" PATH)
+endif ()
+
+include(CMakeFindBinUtils)
+
+# configure variables set in this file for fast reload later on
+configure_file(${CMAKE_ROOT}/Modules/CMakeSwiftCompiler.cmake.in
+  ${CMAKE_PLATFORM_INFO_DIR}/CMakeSwiftCompiler.cmake
+  @ONLY
+  )
diff --git a/Modules/CMakeSwiftCompiler.cmake.in b/Modules/CMakeSwiftCompiler.cmake.in
new file mode 100644
index 0000000000..45f0a31051
--- /dev/null
+++ b/Modules/CMakeSwiftCompiler.cmake.in
@@ -0,0 +1,5 @@
+set(CMAKE_Swift_COMPILER "@CMAKE_Swift_COMPILER@")
+set(CMAKE_Swift_COMPILER_ID "@CMAKE_Swift_COMPILER_ID@")
+
+set(CMAKE_Swift_COMPILER_ID_RUN 1)
+set(CMAKE_Swift_SOURCE_FILE_EXTENSIONS swift)
diff --git a/Modules/CMakeSwiftInformation.cmake b/Modules/CMakeSwiftInformation.cmake
new file mode 100644
index 0000000000..61ad928341
--- /dev/null
+++ b/Modules/CMakeSwiftInformation.cmake
@@ -0,0 +1,41 @@
+
+#=============================================================================
+# Copyright 2004-2015 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+set(CMAKE_Swift_OUTPUT_EXTENSION .o)
+
+# Load compiler-specific information.
+if(CMAKE_Swift_COMPILER_ID)
+  include(Compiler/${CMAKE_Swift_COMPILER_ID}-Swift OPTIONAL)
+endif()
+
+# load the system- and compiler specific files
+if(CMAKE_Swift_COMPILER_ID)
+  # load a hardware specific file, mostly useful for embedded compilers
+  if(CMAKE_SYSTEM_PROCESSOR)
+    include(Platform/${CMAKE_SYSTEM_NAME}-${CMAKE_Swift_COMPILER_ID}-Swift-${CMAKE_SYSTEM_PROCESSOR} OPTIONAL)
+  endif()
+  include(Platform/${CMAKE_SYSTEM_NAME}-${CMAKE_Swift_COMPILER_ID}-Swift OPTIONAL)
+endif()
+
+# for most systems a module is the same as a shared library
+# so unless the variable CMAKE_MODULE_EXISTS is set just
+# copy the values from the LIBRARY variables
+if(NOT CMAKE_MODULE_EXISTS)
+  set(CMAKE_SHARED_MODULE_Swift_FLAGS ${CMAKE_SHARED_LIBRARY_Swift_FLAGS})
+  set(CMAKE_SHARED_MODULE_CREATE_Swift_FLAGS ${CMAKE_SHARED_LIBRARY_CREATE_Swift_FLAGS})
+endif()
+
+include(CMakeCommonLanguageInclude)
+
+set(CMAKE_Swift_INFORMATION_LOADED 1)
diff --git a/Modules/CMakeTestSwiftCompiler.cmake b/Modules/CMakeTestSwiftCompiler.cmake
new file mode 100644
index 0000000000..918642654b
--- /dev/null
+++ b/Modules/CMakeTestSwiftCompiler.cmake
@@ -0,0 +1,15 @@
+
+#=============================================================================
+# Copyright 2003-2015 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+set(CMAKE_Swift_COMPILER_WORKS 1)
diff --git a/Modules/CompilerId/main.swift.in b/Modules/CompilerId/main.swift.in
new file mode 100644
index 0000000000..962e85728e
--- /dev/null
+++ b/Modules/CompilerId/main.swift.in
@@ -0,0 +1 @@
+println("CMakeSwiftCompilerId")