runtime/gc/string.h

   1 /* Copyright (C) 2012 Matthew Fluet.
   2  * Copyright (C) 1999-2007 Henry Cejtin, Matthew Fluet, Suresh
   3  *    Jagannathan, and Stephen Weeks.
   4  * Copyright (C) 1997-2000 NEC Research Institute.
   5  *
   6  * MLton is released under a BSD-style license.
   7  * See the file MLton-LICENSE for details.
   8  */
   9
  10 #if (defined (MLTON_GC_INTERNAL_TYPES))
  11
  12 /* Layout of strings.
  13  * Note, the value passed around is a pointer to the obj member.
  14  */
  15 struct GC_string8_obj {
  16   char chars[1];
  17 };
  18 typedef struct GC_string8 {
  19   GC_arrayCounter counter;
  20   GC_arrayLength length;
  21   GC_header header;
  22   struct GC_string8_obj obj;
  23 } __attribute__ ((packed)) *GC_string8;
  24
  25 COMPILE_TIME_ASSERT(GC_string8__obj_packed,
  26                     offsetof(struct GC_string8, obj) ==
  27                     sizeof(GC_arrayCounter)
  28                     + sizeof(GC_arrayLength)
  29                     + sizeof(GC_header));
  30 COMPILE_TIME_ASSERT(GC_string8_obj__chars_packed,
  31                     offsetof(struct GC_string8_obj, chars) ==
  32                     0);
  33
  34 #endif /* (defined (MLTON_GC_INTERNAL_TYPES)) */
  35
  36 #if (defined (MLTON_GC_INTERNAL_FUNCS))
  37
  38 #define GC_STRING8_HEADER GC_WORD8_VECTOR_HEADER
  39
  40 #endif /* (defined (MLTON_GC_INTERNAL_FUNCS)) */