enforce lua version compatibility

Author: truemedian

CMakeLists.txt

@@ -71,6 +71,20 @@ if (WithSharedLibluv)
   find_package(Libuv  REQUIRED)
   include_directories(${LIBUV_INCLUDE_DIRS})
 
+  include(CheckCSourceCompiles)
+  
+  set(CMAKE_REQUIRED_INCLUDES ${LUAJIT_INCLUDE_DIRS})
+  set(CMAKE_REQUIRED_LIBRARIES ${LUAJIT_LIBRARIES})
+  check_c_source_compiles("
+  #include <luajit.h>
+  int main() {
+    LUAJIT_VERSION_SYM();
+    return 0;
+  }" LUAJIT_HAS_VERSION_SYM)
+  if (NOT LUAJIT_HAS_VERSION_SYM)
+    add_compile_definitions(LUAJIT_MISSING_VERSION_SYM)
+  endif ()
+
   list(APPEND LUVI_LIBRARIES ${LUV_LIBRARIES} ${LUAJIT_LIBRARIES} ${LIBUV_LIBRARIES})
 else (WithSharedLibluv)
   # Build luv as static library instead of as module

src/luvi.h

@@ -22,6 +22,9 @@
 #include "lauxlib.h"
 #include "uv.h"
 #include "luv.h"
+#ifndef WITH_PLAIN_LUA
+#include "luajit.h"
+#endif
 
 #include <string.h>
 #include <stdlib.h>

src/main.c

@@ -55,6 +55,17 @@ static lua_State* vm_acquire(){
   if (L == NULL)
     return L;
 
+  // Ensure that the version of lua interpreter is compatible with the version luvi was compiled with.
+#ifdef WITH_PLAIN_LUA
+#if (LUA_VERSION_NUM >= 502)
+  luaL_checkversion(L);
+#endif
+#else
+#ifndef LUAJIT_MISSING_VERSION_SYM // debian patches luajit to remove this symbol, so we can't check it.
+  LUAJIT_VERSION_SYM();
+#endif
+#endif
+
   // Add in the lua standard and compat libraries
   luvi_openlibs(L);