CODEWITHSUNDEEP
c++linuxc++17
Kenneth
Kenneth

Reputation: 655

C++ function binding at runtime with function name string in Linux

Suppose in the source code, I define a static function void MyFun(void). Then I put a string "void MyFun(void)" in a configuration file. At runtime, I want to load the configuration file to get the string and then create/bind a function-pointer to the corresponding static function. Is it possible to do such a thing (I understand C++ doesn't have reflection)?

Upvotes: 1

Views: 207

Answers (1)

Volodymyr Boyko
Volodymyr Boyko

Reputation: 1581

Another option besides maintaining a map is to compile your code into a shared library and use OS API to lazy load symbols. This is ABI-depended solution though and in C++ you should be aware of name mangling or use extern "C" for function declaration. The POSIX C example is taken from https://rosettacode.org/wiki/Call_a_function_in_a_shared_library#C

#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
 
int main()
{
  void *mylib;
  int (*myfun)(const char *);
 
  mylib = dlopen("./mylib.so", RTLD_LAZY);
  *(void **)(&myfun) = dlsym(mylib, "MyFun");

  /* ... */

  if (mylib) dlclose(mylib);
  return EXIT_SUCCESS;
}

Upvotes: 2

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