LuaJIT FFI load dll error

问题:

I want to code some functions in C to use in Lua and the easiest way to do this I think I can find is using LuaJIT's FFI.

I have a C file "add.c":

int add(int a, int b){ return a+b; } 

I assemble it into "add.o" with:

gcc -c add.c 

I make "add.dll":

gcc - shared -o add.dll add.o 

Finally, I try to run the following Lua code in LuaJIT:

local ffi =require("ffi")  local test=ffi.load("C:\\users\\quebe\\Desktop\\add")  ffi.cdef[[ int add(int a,int b); ]]  print(test.add(1,2)) 

and get:

luajit: test.lua:3: cannot load module 'C:\users\quebe\Desktop\add': %1 is  not a valid Win32 application.  stack traceback:     [C]: in function 'load'     test.lua:3: in main chunk     [C]: at 0x7ff72be120c0 

but I have no idea how to interpret this to debug.

回答1:

According to this, there should be declaration of the C function before loading the dll:

local ffi =require("ffi") ffi.cdef[[    int add(int a, int b) ]] local test=ffi.load("C:\\users\\quebe\\Desktop\\add") 

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addendum:

Additionally, as Egor Skriptunoff mentioned, functions inside the dll file should be declared as exported. The specifics are given in this SO answer.

文章来源: LuaJIT FFI load dll error