From 430b62322355c0bfe6233586c9823013d60a3335 Mon Sep 17 00:00:00 2001
From: Mattes D <github@xoft.cz>
Date: Sun, 17 Jul 2016 16:23:29 +0200
Subject: [PATCH] Use system Lua, if available, to generate bindings.

Closes #1031.
---
 CMakeLists.txt              | 12 ++++++++++++
 CheckLua.cmake              | 23 +++++++++++++++++++++++
 src/Bindings/CMakeLists.txt | 27 +++++++++++++++------------
 src/CMakeLists.txt          | 33 ++++++++++++++++++++++-----------
 4 files changed, 72 insertions(+), 23 deletions(-)
 create mode 100644 CheckLua.cmake

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 02de722bb..f5ea75ba5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -92,6 +92,18 @@ endif()
 set(BUILD_TOOLS OFF CACHE BOOL "")
 set(SELF_TEST OFF CACHE BOOL "")
 
+# Check whether Lua 5.1 is installed locally:
+include(CheckLua.cmake)
+if(HAS_LUA_INTERPRETER AND ("${LUA_INTERPRETER_VERSION}" STREQUAL "5.1"))
+	message(STATUS "Lua 5.1 has been found in your system and will be used for the build.")
+else()
+	if (CROSSCOMPILE)
+		message(FATAL "To crosscompile, you need to have Lua 5.1 installed in your system and available in PATH.")
+	endif()
+	message(STATUS "Lua 5.1 has NOT been found in your system, the build will use its own Lua implementation.")
+endif()
+
+
 # This has to be done before any flags have been set up.
 if(${BUILD_TOOLS})
 	message("Building tools")
diff --git a/CheckLua.cmake b/CheckLua.cmake
new file mode 100644
index 000000000..e8827fe00
--- /dev/null
+++ b/CheckLua.cmake
@@ -0,0 +1,23 @@
+# CheckLua.cmake
+
+# Checks whether the Lua standalone interpreter is installed on the host system
+# If found, sets HAS_LUA_INTERPRETER to 1 and LUA_INTERPRETER_VERSION to the version reported ("5.1" etc.)
+# If not found, unsets HAS_LUA_INTERPRETER
+
+
+
+
+execute_process(
+	COMMAND lua -e "io.stdout:write(string.match(_VERSION, '%d+%.%d+'))"
+	RESULT_VARIABLE LUA_EXECUTED
+	OUTPUT_VARIABLE LUA_INTERPRETER_VERSION
+)
+
+if ("${LUA_EXECUTED}" STREQUAL "0")
+	set(HAS_LUA_INTERPRETER 1)
+else()
+	unset(HAS_LUA_INTERPRETER)
+	unset(LUA_INTERPRETER_VERSION)
+endif()
+
+unset(LUA_EXECUTED)
diff --git a/src/Bindings/CMakeLists.txt b/src/Bindings/CMakeLists.txt
index 5c79225cc..05d4c7e4f 100644
--- a/src/Bindings/CMakeLists.txt
+++ b/src/Bindings/CMakeLists.txt
@@ -56,7 +56,6 @@ set (BINDING_OUTPUTS
 )
 
 set(BINDING_DEPENDENCIES
-	tolua
 	../Bindings/AllToLua.pkg
 	../Bindings/BindingsProcessor.lua
 	../Bindings/LuaFunctions.h
@@ -139,17 +138,21 @@ set(BINDING_DEPENDENCIES
 )
 
 if (NOT MSVC)
-	ADD_CUSTOM_COMMAND(
-		# add any new generated bindings here
-		OUTPUT ${BINDING_OUTPUTS}
-
-		# Regenerate bindings:
-		COMMAND tolua -L BindingsProcessor.lua -o Bindings.cpp -H Bindings.h AllToLua.pkg
-		WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
-
-		# add any new generation dependencies here
-		DEPENDS ${BINDING_DEPENDENCIES}
-	)
+	if (HAS_LUA_INTERPRETER)
+		ADD_CUSTOM_COMMAND(
+			OUTPUT ${BINDING_OUTPUTS}
+			COMMAND lua BindingsProcessor.lua
+			WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+			DEPENDS ${BINDING_DEPENDENCIES}
+		)
+	else()
+		ADD_CUSTOM_COMMAND(
+			OUTPUT ${BINDING_OUTPUTS}
+			COMMAND tolua -L BindingsProcessor.lua -o Bindings.cpp -H Bindings.h AllToLua.pkg
+			WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+			DEPENDS ${BINDING_DEPENDENCIES} tolua
+		)
+	endif()
 endif ()
 
 set_source_files_properties(${BINDING_OUTPUTS} PROPERTIES GENERATED TRUE)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5bf55c81f..075d48968 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -252,6 +252,10 @@ else ()
 		foreach (hdr ${FOLDER_HDRS})
 			list(APPEND SOURCE "${folder}/${hdr}")
 		endforeach(hdr)
+
+		# Include this folder's CMakeLists.txt in the project:
+		list(APPEND SOURCE "${folder}/CMakeLists.txt")
+		source_group("${folder}" FILES "${folder}/CMakeLists.txt")
 	endforeach(folder)
 
 	list(APPEND SOURCE "${SRCS}")
@@ -315,19 +319,26 @@ if (MSVC)
 		list (APPEND BINDINGS_DEPENDENCIES "Bindings/${dep}")
 	endforeach(dep)
 
-	ADD_CUSTOM_COMMAND(
-		OUTPUT ${BINDING_OUTPUTS}
+	if (HAS_LUA_INTERPRETER)
+		ADD_CUSTOM_COMMAND(
+			OUTPUT ${BINDING_OUTPUTS}
+			COMMAND lua BindingsProcessor.lua
+			WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/Bindings/
+			DEPENDS ${BINDINGS_DEPENDENCIES}
+		)
+	else()
+		ADD_CUSTOM_COMMAND(
+			OUTPUT ${BINDING_OUTPUTS}
 
-		# Copy the Lua DLL into the Bindings folder, so that tolua can run from there:
-		COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_SOURCE_DIR}/Server/lua51.dll ./lua51.dll
+			# Copy the Lua DLL into the Bindings folder, so that tolua can run from there:
+			COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_SOURCE_DIR}/Server/lua51.dll ./lua51.dll
 
-		# Regenerate bindings:
-		COMMAND tolua -L BindingsProcessor.lua -o Bindings.cpp -H Bindings.h AllToLua.pkg
-		WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/Bindings/
-
-		# add any new generation dependencies here
-		DEPENDS ${BINDINGS_DEPENDENCIES}
-	)
+			# Regenerate bindings:
+			COMMAND tolua -L BindingsProcessor.lua -o Bindings.cpp -H Bindings.h AllToLua.pkg
+			WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/Bindings/
+			DEPENDS ${BINDINGS_DEPENDENCIES} tolua
+		)
+	endif()
 endif()
 
 add_executable(${EXECUTABLE} ${SOURCE})