From d5c89b18968e9f400183c98493faa5a25f6f07df Mon Sep 17 00:00:00 2001
From: Rui Abreu Ferreira <raf-ep@gmx.com>
Date: Sun, 8 May 2016 03:06:46 +0100
Subject: [PATCH] cmake: Allow building without Luajit

By default Neovim searched a Luajit instalation and linked against
the luajit library.

In practice Neovim only requires luajit to run the unit tests. All other
targets only require lua and the correct lua modules. This commit:

1. Remove the strict dependency on Luajit
2. Makes the unittest target depend on the lua 'ffi' module.
   If the module is not available the target is not enabled
   and a message is displayed.
---
 CMakeLists.txt          | 33 ++++++++++++++++++---------------
 cmake/LuaHelpers.cmake  |  4 ++--
 src/nvim/CMakeLists.txt |  1 -
 3 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1abc05f0da..317d2a1a5b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -300,9 +300,6 @@ include_directories(SYSTEM ${LIBUV_INCLUDE_DIRS})
 find_package(Msgpack 1.0.0 REQUIRED)
 include_directories(SYSTEM ${MSGPACK_INCLUDE_DIRS})
 
-find_package(LuaJit REQUIRED)
-include_directories(SYSTEM ${LUAJIT_INCLUDE_DIRS})
-
 find_package(Unibilium REQUIRED)
 include_directories(SYSTEM ${UNIBILIUM_INCLUDE_DIRS})
 
@@ -477,18 +474,24 @@ if(BUSTED_PRG)
   add_custom_target(benchmark-prereqs
     DEPENDS ${BENCHMARK_PREREQS})
 
-  add_custom_target(unittest
-    COMMAND ${CMAKE_COMMAND}
-      -DBUSTED_PRG=${BUSTED_PRG}
-      -DLUA_PRG=${LUA_PRG}
-      -DWORKING_DIR=${CMAKE_CURRENT_SOURCE_DIR}
-      -DBUSTED_OUTPUT_TYPE=${BUSTED_OUTPUT_TYPE}
-      -DTEST_DIR=${CMAKE_CURRENT_SOURCE_DIR}/test
-      -DBUILD_DIR=${CMAKE_BINARY_DIR}
-      -DTEST_TYPE=unit
-      -P ${PROJECT_SOURCE_DIR}/cmake/RunTests.cmake
-    DEPENDS ${UNITTEST_PREREQS}
-    ${TEST_TARGET_ARGS})
+  check_lua_module(${LUA_PRG} "ffi" LUA_HAS_FFI)
+  if(LUA_HAS_FFI)
+    add_custom_target(unittest
+      COMMAND ${CMAKE_COMMAND}
+        -DBUSTED_PRG=${BUSTED_PRG}
+        -DLUA_PRG=${LUA_PRG}
+        -DWORKING_DIR=${CMAKE_CURRENT_SOURCE_DIR}
+        -DBUSTED_OUTPUT_TYPE=${BUSTED_OUTPUT_TYPE}
+        -DTEST_DIR=${CMAKE_CURRENT_SOURCE_DIR}/test
+        -DBUILD_DIR=${CMAKE_BINARY_DIR}
+        -DTEST_TYPE=unit
+        -P ${PROJECT_SOURCE_DIR}/cmake/RunTests.cmake
+      DEPENDS ${UNITTEST_PREREQS}
+      ${TEST_TARGET_ARGS})
+  else()
+    message(WARNING "The Luajit ffi is not available in ${LUA_PRG}"
+	    ", disabling unit tests")
+  endif()
 
   add_custom_target(functionaltest
     COMMAND ${CMAKE_COMMAND}
diff --git a/cmake/LuaHelpers.cmake b/cmake/LuaHelpers.cmake
index b1e67e0ca7..32f7e46a57 100644
--- a/cmake/LuaHelpers.cmake
+++ b/cmake/LuaHelpers.cmake
@@ -8,8 +8,6 @@ function(check_lua_module LUA_PRG_PATH MODULE RESULT_VAR)
     RESULT_VARIABLE module_missing
     ERROR_QUIET)
   if(module_missing)
-    message(STATUS
-      "[${LUA_PRG_PATH}] The '${MODULE}' lua package is required for building Neovim")
     set(${RESULT_VAR} False PARENT_SCOPE)
   else()
     set(${RESULT_VAR} True PARENT_SCOPE)
@@ -29,6 +27,8 @@ function(check_lua_deps LUA_PRG_PATH MODULES RESULT_VAR)
   foreach(module ${MODULES})
     check_lua_module(${LUA_PRG_PATH} ${module} has_module)
     if(NOT has_module)
+      message(STATUS
+        "[${LUA_PRG_PATH}] The '${module}' lua package is required for building Neovim")
       set(${RESULT_VAR} False PARENT_SCOPE)
       return()
     endif()
diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index 6b2ce08d36..172643091a 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -231,7 +231,6 @@ endif()
 list(APPEND NVIM_LINK_LIBRARIES
   ${LIBUV_LIBRARIES}
   ${MSGPACK_LIBRARIES}
-  ${LUAJIT_LIBRARIES}
   ${LIBVTERM_LIBRARIES}
   ${LIBTERMKEY_LIBRARIES}
   ${UNIBILIUM_LIBRARIES}