src/base/symbol/cl_sy_hashcode.cc

   1 // cl_symbol hashcode().
   2
   3 // General includes.
   4 #include "cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cl_symbol.h"
   8
   9
  10 // Implementation.
  11
  12 #include "cl_offsetof.h"
  13
  14 #define declare_alignof(where,type)  \
  15   struct CONCAT(aligndummy,__LINE__) { char slot1; type slot2; }; \
  16   const unsigned long where = offsetof(CONCAT(aligndummy,__LINE__), slot2);
  17
  18 unsigned long hashcode (const cl_symbol& s)
  19 {
  20         // Strings don't move in memory, so we can just take the address.
  21         declare_alignof(string_alignment,cl_heap_string);
  22         return (unsigned long)(s.pointer)
  23                / (string_alignment & -string_alignment); // divide by power of 2
  24 }