currify

currify.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>

typedef int (*SIN)(int);
typedef int (*DOU)(int,int);

int proto(int b){
  DOU fun=(DOU)'+';
  int a=(int)'-';
  return fun(a,b);
}

int _proto(){return 0;}

SIN currify(DOU fun,int a){
  long size = (long)_proto - (long)proto;
  void* this = valloc(size);
  char* i;
  memcpy(this,proto,size);
  int err = mprotect(this, size, PROT_READ | PROT_WRITE | PROT_EXEC);
  if(err){exit(1);}
  for(i = (char*) this;i<(char*) this+size;i++){
    if(*i=='+'){
      *((DOU *)i)=fun;
    }
    if(*i=='-'){
      *((int *)i)=a;
    }
  }
  return (SIN)(this);
}

int add(int a,int b){return a+b;}
int times(int a,int b){return a*b;}
int divide(int a,int b){return b/a;}

int main(){
  SIN add3 = currify(add,3);
  printf("%d\n",add3(3));
  return 0;
}

log

0x55555555a000  push   %rbp
0x55555555a001  mov    %rsp,%rbp
0x55555555a004  sub    $0x20,%rsp
0x55555555a008  mov    %edi,-0x14(%rbp)
0x55555555a00b  movq   $0x2b,-0x8(%rbp)         //
0x55555555a013  movl   $0x2d,-0xc(%rbp)
0x55555555a01a  mov    -0x14(%rbp),%ecx
0x55555555a01d  mov    -0xc(%rbp),%edx
0x55555555a020  mov    -0x8(%rbp),%rax
0x55555555a024  mov    %ecx,%esi
0x55555555a026  mov    %edx,%edi
0x55555555a028  callq  *%rax
0x55555555a02a  leaveq

fun = 0x555555555279
a = 3

0x55555555a000  push   %rbp
0x55555555a001  mov    %rsp,%rbp
0x55555555a004  sub    $0x20,%rsp
0x55555555a008  mov    %edi,-0x14(%rbp)
0x55555555a00b  movq   $0x55555279,-0x8(%rbp)   //
0x55555555a013  push   %rbp
0x55555555a014  push   %rbp
0x55555555a015  add    %al,(%rax)
0x55555555a017  add    %al,(%rax)
0x55555555a019  add    %cl,0x558bec4d(%rbx)
0x55555555a01f  hlt
0x55555555a020  mov    -0x8(%rbp),%rax
0x55555555a024  mov    %ecx,%esi
0x55555555a026  mov    %edx,%edi
0x55555555a028  callq  *%rax
0x55555555a02a  leaveq