Modules/FindLua.cmake - third_party/github.com/Kitware/CMake - Git at Google

 # Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
 # file LICENSE.rst or https://cmake.org/licensing for details.

 #[=======================================================================[.rst:
 FindLua
 -------

 Finds the Lua library.  Lua is a embeddable scripting language.

 .. versionadded:: 3.18
   Support for Lua 5.4.

 When working with Lua, its library headers are intended to be included in
 project source code as:

 .. code-block:: c

   #include <lua.h>

 and not:

 .. code-block:: c

   #include <lua/lua.h>

 This is because, the location of Lua headers may differ across platforms and may
 exist in locations other than ``lua/``.

 Result Variables
 ^^^^^^^^^^^^^^^^

 This module defines the following variables:

 ``Lua_FOUND``
   Boolean indicating whether (the requested version of) Lua is found.  For
   backward compatibility, the ``LUA_FOUND`` variable is also set to the same
   value.
 ``LUA_VERSION_STRING``
   The version of Lua found.
 ``LUA_VERSION_MAJOR``
   The major version of Lua found.
 ``LUA_VERSION_MINOR``
   The minor version of Lua found.
 ``LUA_VERSION_PATCH``
   The patch version of Lua found.
 ``LUA_LIBRARIES``
   Libraries needed to link against to use Lua.  This list includes both ``lua``
   and ``lualib`` libraries.

 Cache Variables
 ^^^^^^^^^^^^^^^

 The following cache variables may also be set:

 ``LUA_INCLUDE_DIR``
   The directory containing the Lua header files, such as ``lua.h``,
   ``lualib.h``, and ``lauxlib.h``, needed to use Lua.

 Examples
 ^^^^^^^^

 Finding the Lua library and creating an interface :ref:`imported target
 <Imported Targets>` that encapsulates its usage requirements for linking to a
 project target:

 .. code-block:: cmake

   find_package(Lua)

   if(Lua_FOUND AND NOT TARGET Lua::Lua)
     add_library(Lua::Lua INTERFACE IMPORTED)
     set_target_properties(
       Lua::Lua
       PROPERTIES
         INTERFACE_INCLUDE_DIRECTORIES "${LUA_INCLUDE_DIR}"
         INTERFACE_LINK_LIBRARIES "${LUA_LIBRARIES}"
     )
   endif()

   target_link_libraries(project_target PRIVATE Lua::Lua)
 #]=======================================================================]

 cmake_policy(PUSH)  # Policies apply to functions at definition-time
 cmake_policy(SET CMP0159 NEW)  # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>

 unset(_lua_include_subdirs)
 unset(_lua_library_names)
 unset(_lua_append_versions)

 # this is a function only to have all the variables inside go away automatically
 function(_lua_get_versions)
     set(LUA_VERSIONS5 5.4 5.3 5.2 5.1 5.0)

     if (Lua_FIND_VERSION_EXACT)
         if (Lua_FIND_VERSION_COUNT GREATER 1)
             set(_lua_append_versions ${Lua_FIND_VERSION_MAJOR}.${Lua_FIND_VERSION_MINOR})
         endif ()
     elseif (Lua_FIND_VERSION)
         # once there is a different major version supported this should become a loop
         if (NOT Lua_FIND_VERSION_MAJOR GREATER 5)
             if (Lua_FIND_VERSION_COUNT EQUAL 1)
                 set(_lua_append_versions ${LUA_VERSIONS5})
             else ()
                 foreach (subver IN LISTS LUA_VERSIONS5)
                     if (NOT subver VERSION_LESS ${Lua_FIND_VERSION})
                         list(APPEND _lua_append_versions ${subver})
                     endif ()
                 endforeach ()
                 # New version -> Search for it (heuristic only! Defines in include might have changed)
                 if (NOT _lua_append_versions)
                     set(_lua_append_versions ${Lua_FIND_VERSION_MAJOR}.${Lua_FIND_VERSION_MINOR})
                 endif()
             endif ()
         endif ()
     else ()
         # once there is a different major version supported this should become a loop
         set(_lua_append_versions ${LUA_VERSIONS5})
     endif ()

     if (LUA_Debug)
         message(STATUS "Considering following Lua versions: ${_lua_append_versions}")
     endif()

     set(_lua_append_versions "${_lua_append_versions}" PARENT_SCOPE)
 endfunction()

 function(_lua_set_version_vars)
   set(_lua_include_subdirs_raw "lua")

   foreach (ver IN LISTS _lua_append_versions)
     string(REGEX MATCH "^([0-9]+)\\.([0-9]+)$" _ver "${ver}")
     list(APPEND _lua_include_subdirs_raw
         lua${CMAKE_MATCH_1}${CMAKE_MATCH_2}
         lua${CMAKE_MATCH_1}.${CMAKE_MATCH_2}
         lua-${CMAKE_MATCH_1}.${CMAKE_MATCH_2}
         )
   endforeach ()

   # Prepend "include/" to each path directly after the path
   set(_lua_include_subdirs "include")
   foreach (dir IN LISTS _lua_include_subdirs_raw)
     list(APPEND _lua_include_subdirs "${dir}" "include/${dir}")
   endforeach ()

   set(_lua_include_subdirs "${_lua_include_subdirs}" PARENT_SCOPE)
 endfunction()

 function(_lua_get_header_version)
   unset(LUA_VERSION_STRING PARENT_SCOPE)
   set(_hdr_file "${LUA_INCLUDE_DIR}/lua.h")

   if (NOT EXISTS "${_hdr_file}")
     return()
   endif ()

   # At least 5.[012] have different ways to express the version
   # so all of them need to be tested. Lua 5.2 defines LUA_VERSION
   # and LUA_RELEASE as joined by the C preprocessor, so avoid those.
   file(STRINGS "${_hdr_file}" lua_version_strings
        REGEX "^#define[ \t]+LUA_(RELEASE[ \t]+\"Lua [0-9]|VERSION([ \t]+\"Lua [0-9]|_[MR])).*")

   string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION_MAJOR[ \t]+\"([0-9])\"[ \t]*;.*" "\\1" LUA_VERSION_MAJOR ";${lua_version_strings};")
   if (LUA_VERSION_MAJOR MATCHES "^[0-9]+$")
     string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION_MINOR[ \t]+\"([0-9])\"[ \t]*;.*" "\\1" LUA_VERSION_MINOR ";${lua_version_strings};")
     string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION_RELEASE[ \t]+\"([0-9])\"[ \t]*;.*" "\\1" LUA_VERSION_PATCH ";${lua_version_strings};")
     set(LUA_VERSION_STRING "${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}.${LUA_VERSION_PATCH}")
   else ()
     string(REGEX REPLACE ".*;#define[ \t]+LUA_RELEASE[ \t]+\"Lua ([0-9.]+)\"[ \t]*;.*" "\\1" LUA_VERSION_STRING ";${lua_version_strings};")
     if (NOT LUA_VERSION_STRING MATCHES "^[0-9.]+$")
       string(REGEX REPLACE ".*;#define[ \t]+LUA_VERSION[ \t]+\"Lua ([0-9.]+)\"[ \t]*;.*" "\\1" LUA_VERSION_STRING ";${lua_version_strings};")
     endif ()
     string(REGEX REPLACE "^([0-9]+)\\.[0-9.]*$" "\\1" LUA_VERSION_MAJOR "${LUA_VERSION_STRING}")
     string(REGEX REPLACE "^[0-9]+\\.([0-9]+)[0-9.]*$" "\\1" LUA_VERSION_MINOR "${LUA_VERSION_STRING}")
     string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]).*" "\\1" LUA_VERSION_PATCH "${LUA_VERSION_STRING}")
   endif ()
   foreach (ver IN LISTS _lua_append_versions)
     if (ver STREQUAL "${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}")
       set(LUA_VERSION_MAJOR ${LUA_VERSION_MAJOR} PARENT_SCOPE)
       set(LUA_VERSION_MINOR ${LUA_VERSION_MINOR} PARENT_SCOPE)
       set(LUA_VERSION_PATCH ${LUA_VERSION_PATCH} PARENT_SCOPE)
       set(LUA_VERSION_STRING ${LUA_VERSION_STRING} PARENT_SCOPE)
       return()
     endif ()
   endforeach ()
 endfunction()

 function(_lua_find_header)
   _lua_set_version_vars()

   # Initialize as local variable
   set(CMAKE_IGNORE_PATH ${CMAKE_IGNORE_PATH})
   while (TRUE)
     # Find the next header to test. Check each possible subdir in order
     # This prefers e.g. higher versions as they are earlier in the list
     # It is also consistent with previous versions of FindLua
     foreach (subdir IN LISTS _lua_include_subdirs)
       find_path(LUA_INCLUDE_DIR lua.h
         HINTS ENV LUA_DIR
         PATH_SUFFIXES ${subdir}
         )
       if (LUA_INCLUDE_DIR)
         break()
       endif()
     endforeach()
     # Did not found header -> Fail
     if (NOT LUA_INCLUDE_DIR)
       return()
     endif()
     _lua_get_header_version()
     # Found accepted version -> Ok
     if (LUA_VERSION_STRING)
       if (LUA_Debug)
         message(STATUS "Found suitable version ${LUA_VERSION_STRING} in ${LUA_INCLUDE_DIR}/lua.h")
       endif()
       return()
     endif()
     # Found wrong version -> Ignore this path and retry
     if (LUA_Debug)
       message(STATUS "Ignoring unsuitable version in ${LUA_INCLUDE_DIR}")
     endif()
     list(APPEND CMAKE_IGNORE_PATH "${LUA_INCLUDE_DIR}")
     unset(LUA_INCLUDE_DIR CACHE)
     unset(LUA_INCLUDE_DIR)
     unset(LUA_INCLUDE_DIR PARENT_SCOPE)
   endwhile ()
 endfunction()

 _lua_get_versions()
 _lua_find_header()
 _lua_get_header_version()
 unset(_lua_append_versions)

 if (LUA_VERSION_STRING)
   set(_lua_library_names
     lua${LUA_VERSION_MAJOR}${LUA_VERSION_MINOR}
     lua${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}
     lua-${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}
     lua.${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}
     )
 endif ()

 find_library(LUA_LIBRARY
   NAMES ${_lua_library_names} lua
   NAMES_PER_DIR
   HINTS
     ENV LUA_DIR
   PATH_SUFFIXES lib
 )
 unset(_lua_library_names)

 if (LUA_LIBRARY)
   # include the math library for Unix
   if (UNIX AND NOT APPLE AND NOT BEOS)
     find_library(LUA_MATH_LIBRARY m)
     mark_as_advanced(LUA_MATH_LIBRARY)
     set(LUA_LIBRARIES "${LUA_LIBRARY};${LUA_MATH_LIBRARY}")

     # include dl library for statically-linked Lua library
     get_filename_component(LUA_LIB_EXT ${LUA_LIBRARY} EXT)
     if(LUA_LIB_EXT STREQUAL CMAKE_STATIC_LIBRARY_SUFFIX)
       list(APPEND LUA_LIBRARIES ${CMAKE_DL_LIBS})
     endif()

   # For Windows and Mac, don't need to explicitly include the math library
   else ()
     set(LUA_LIBRARIES "${LUA_LIBRARY}")
   endif ()
 endif ()

 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Lua
                                   REQUIRED_VARS LUA_LIBRARIES LUA_INCLUDE_DIR
                                   VERSION_VAR LUA_VERSION_STRING)

 mark_as_advanced(LUA_INCLUDE_DIR LUA_LIBRARY)

 cmake_policy(POP)
	# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
	# file LICENSE.rst or https://cmake.org/licensing for details.

	#[=======================================================================[.rst:
	FindLua
	-------

	Finds the Lua library. Lua is a embeddable scripting language.

	.. versionadded:: 3.18
	Support for Lua 5.4.

	When working with Lua, its library headers are intended to be included in
	project source code as:

	.. code-block:: c

	#include <lua.h>

	and not:

	.. code-block:: c

	#include <lua/lua.h>

	This is because, the location of Lua headers may differ across platforms and may
	exist in locations other than ``lua/``.

	Result Variables
	^^^^^^^^^^^^^^^^

	This module defines the following variables:

	``Lua_FOUND``
	Boolean indicating whether (the requested version of) Lua is found. For
	backward compatibility, the ``LUA_FOUND`` variable is also set to the same
	value.
	``LUA_VERSION_STRING``
	The version of Lua found.
	``LUA_VERSION_MAJOR``
	The major version of Lua found.
	``LUA_VERSION_MINOR``
	The minor version of Lua found.
	``LUA_VERSION_PATCH``
	The patch version of Lua found.
	``LUA_LIBRARIES``
	Libraries needed to link against to use Lua. This list includes both ``lua``
	and ``lualib`` libraries.

	Cache Variables
	^^^^^^^^^^^^^^^

	The following cache variables may also be set:

	``LUA_INCLUDE_DIR``
	The directory containing the Lua header files, such as ``lua.h``,
	``lualib.h``, and ``lauxlib.h``, needed to use Lua.

	Examples
	^^^^^^^^

	Finding the Lua library and creating an interface :ref:`imported target
	<Imported Targets>` that encapsulates its usage requirements for linking to a
	project target:

	.. code-block:: cmake

	find_package(Lua)

	if(Lua_FOUND AND NOT TARGET Lua::Lua)
	add_library(Lua::Lua INTERFACE IMPORTED)
	set_target_properties(
	Lua::Lua
	PROPERTIES
	INTERFACE_INCLUDE_DIRECTORIES "${LUA_INCLUDE_DIR}"
	INTERFACE_LINK_LIBRARIES "${LUA_LIBRARIES}"
	)
	endif()

	target_link_libraries(project_target PRIVATE Lua::Lua)
	#]=======================================================================]

	cmake_policy(PUSH) # Policies apply to functions at definition-time
	cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>

	unset(_lua_include_subdirs)
	unset(_lua_library_names)
	unset(_lua_append_versions)

	# this is a function only to have all the variables inside go away automatically
	function(_lua_get_versions)
	set(LUA_VERSIONS5 5.4 5.3 5.2 5.1 5.0)

	if (Lua_FIND_VERSION_EXACT)
	if (Lua_FIND_VERSION_COUNT GREATER 1)
	set(_lua_append_versions ${Lua_FIND_VERSION_MAJOR}.${Lua_FIND_VERSION_MINOR})
	endif ()
	elseif (Lua_FIND_VERSION)
	# once there is a different major version supported this should become a loop
	if (NOT Lua_FIND_VERSION_MAJOR GREATER 5)
	if (Lua_FIND_VERSION_COUNT EQUAL 1)
	set(_lua_append_versions ${LUA_VERSIONS5})
	else ()
	foreach (subver IN LISTS LUA_VERSIONS5)
	if (NOT subver VERSION_LESS ${Lua_FIND_VERSION})
	list(APPEND _lua_append_versions ${subver})
	endif ()
	endforeach ()
	# New version -> Search for it (heuristic only! Defines in include might have changed)
	if (NOT _lua_append_versions)
	set(_lua_append_versions ${Lua_FIND_VERSION_MAJOR}.${Lua_FIND_VERSION_MINOR})
	endif()
	endif ()
	endif ()
	else ()
	# once there is a different major version supported this should become a loop
	set(_lua_append_versions ${LUA_VERSIONS5})
	endif ()

	if (LUA_Debug)
	message(STATUS "Considering following Lua versions: ${_lua_append_versions}")
	endif()

	set(_lua_append_versions "${_lua_append_versions}" PARENT_SCOPE)
	endfunction()

	function(_lua_set_version_vars)
	set(_lua_include_subdirs_raw "lua")

	foreach (ver IN LISTS _lua_append_versions)
	string(REGEX MATCH "^([0-9]+)\\.([0-9]+)$" _ver "${ver}")
	list(APPEND _lua_include_subdirs_raw
	lua${CMAKE_MATCH_1}${CMAKE_MATCH_2}
	lua${CMAKE_MATCH_1}.${CMAKE_MATCH_2}
	lua-${CMAKE_MATCH_1}.${CMAKE_MATCH_2}
	)
	endforeach ()

	# Prepend "include/" to each path directly after the path
	set(_lua_include_subdirs "include")
	foreach (dir IN LISTS _lua_include_subdirs_raw)
	list(APPEND _lua_include_subdirs "${dir}" "include/${dir}")
	endforeach ()

	set(_lua_include_subdirs "${_lua_include_subdirs}" PARENT_SCOPE)
	endfunction()

	function(_lua_get_header_version)
	unset(LUA_VERSION_STRING PARENT_SCOPE)
	set(_hdr_file "${LUA_INCLUDE_DIR}/lua.h")

	if (NOT EXISTS "${_hdr_file}")
	return()
	endif ()

	# At least 5.[012] have different ways to express the version
	# so all of them need to be tested. Lua 5.2 defines LUA_VERSION
	# and LUA_RELEASE as joined by the C preprocessor, so avoid those.
	file(STRINGS "${_hdr_file}" lua_version_strings
	REGEX "^#define[ \t]+LUA_(RELEASE[ \t]+\"Lua [0-9]\|VERSION([ \t]+\"Lua [0-9]\|_[MR])).*")

	string(REGEX REPLACE ".;#define[ \t]+LUA_VERSION_MAJOR[ \t]+\"([0-9])\"[ \t];.*" "\\1" LUA_VERSION_MAJOR ";${lua_version_strings};")
	if (LUA_VERSION_MAJOR MATCHES "^[0-9]+$")
	string(REGEX REPLACE ".;#define[ \t]+LUA_VERSION_MINOR[ \t]+\"([0-9])\"[ \t];.*" "\\1" LUA_VERSION_MINOR ";${lua_version_strings};")
	string(REGEX REPLACE ".;#define[ \t]+LUA_VERSION_RELEASE[ \t]+\"([0-9])\"[ \t];.*" "\\1" LUA_VERSION_PATCH ";${lua_version_strings};")
	set(LUA_VERSION_STRING "${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}.${LUA_VERSION_PATCH}")
	else ()
	string(REGEX REPLACE ".;#define[ \t]+LUA_RELEASE[ \t]+\"Lua ([0-9.]+)\"[ \t];.*" "\\1" LUA_VERSION_STRING ";${lua_version_strings};")
	if (NOT LUA_VERSION_STRING MATCHES "^[0-9.]+$")
	string(REGEX REPLACE ".;#define[ \t]+LUA_VERSION[ \t]+\"Lua ([0-9.]+)\"[ \t];.*" "\\1" LUA_VERSION_STRING ";${lua_version_strings};")
	endif ()
	string(REGEX REPLACE "^([0-9]+)\\.[0-9.]*$" "\\1" LUA_VERSION_MAJOR "${LUA_VERSION_STRING}")
	string(REGEX REPLACE "^[0-9]+\\.([0-9]+)[0-9.]*$" "\\1" LUA_VERSION_MINOR "${LUA_VERSION_STRING}")
	string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]).*" "\\1" LUA_VERSION_PATCH "${LUA_VERSION_STRING}")
	endif ()
	foreach (ver IN LISTS _lua_append_versions)
	if (ver STREQUAL "${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}")
	set(LUA_VERSION_MAJOR ${LUA_VERSION_MAJOR} PARENT_SCOPE)
	set(LUA_VERSION_MINOR ${LUA_VERSION_MINOR} PARENT_SCOPE)
	set(LUA_VERSION_PATCH ${LUA_VERSION_PATCH} PARENT_SCOPE)
	set(LUA_VERSION_STRING ${LUA_VERSION_STRING} PARENT_SCOPE)
	return()
	endif ()
	endforeach ()
	endfunction()

	function(_lua_find_header)
	_lua_set_version_vars()

	# Initialize as local variable
	set(CMAKE_IGNORE_PATH ${CMAKE_IGNORE_PATH})
	while (TRUE)
	# Find the next header to test. Check each possible subdir in order
	# This prefers e.g. higher versions as they are earlier in the list
	# It is also consistent with previous versions of FindLua
	foreach (subdir IN LISTS _lua_include_subdirs)
	find_path(LUA_INCLUDE_DIR lua.h
	HINTS ENV LUA_DIR
	PATH_SUFFIXES ${subdir}
	)
	if (LUA_INCLUDE_DIR)
	break()
	endif()
	endforeach()
	# Did not found header -> Fail
	if (NOT LUA_INCLUDE_DIR)
	return()
	endif()
	_lua_get_header_version()
	# Found accepted version -> Ok
	if (LUA_VERSION_STRING)
	if (LUA_Debug)
	message(STATUS "Found suitable version ${LUA_VERSION_STRING} in ${LUA_INCLUDE_DIR}/lua.h")
	endif()
	return()
	endif()
	# Found wrong version -> Ignore this path and retry
	if (LUA_Debug)
	message(STATUS "Ignoring unsuitable version in ${LUA_INCLUDE_DIR}")
	endif()
	list(APPEND CMAKE_IGNORE_PATH "${LUA_INCLUDE_DIR}")
	unset(LUA_INCLUDE_DIR CACHE)
	unset(LUA_INCLUDE_DIR)
	unset(LUA_INCLUDE_DIR PARENT_SCOPE)
	endwhile ()
	endfunction()

	_lua_get_versions()
	_lua_find_header()
	_lua_get_header_version()
	unset(_lua_append_versions)

	if (LUA_VERSION_STRING)
	set(_lua_library_names
	lua${LUA_VERSION_MAJOR}${LUA_VERSION_MINOR}
	lua${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}
	lua-${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}
	lua.${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}
	)
	endif ()

	find_library(LUA_LIBRARY
	NAMES ${_lua_library_names} lua
	NAMES_PER_DIR
	HINTS
	ENV LUA_DIR
	PATH_SUFFIXES lib
	)
	unset(_lua_library_names)

	if (LUA_LIBRARY)
	# include the math library for Unix
	if (UNIX AND NOT APPLE AND NOT BEOS)
	find_library(LUA_MATH_LIBRARY m)
	mark_as_advanced(LUA_MATH_LIBRARY)
	set(LUA_LIBRARIES "${LUA_LIBRARY};${LUA_MATH_LIBRARY}")

	# include dl library for statically-linked Lua library
	get_filename_component(LUA_LIB_EXT ${LUA_LIBRARY} EXT)
	if(LUA_LIB_EXT STREQUAL CMAKE_STATIC_LIBRARY_SUFFIX)
	list(APPEND LUA_LIBRARIES ${CMAKE_DL_LIBS})
	endif()

	# For Windows and Mac, don't need to explicitly include the math library
	else ()
	set(LUA_LIBRARIES "${LUA_LIBRARY}")
	endif ()
	endif ()

	include(FindPackageHandleStandardArgs)
	find_package_handle_standard_args(Lua
	REQUIRED_VARS LUA_LIBRARIES LUA_INCLUDE_DIR
	VERSION_VAR LUA_VERSION_STRING)

	mark_as_advanced(LUA_INCLUDE_DIR LUA_LIBRARY)

	cmake_policy(POP)