lily/include/ly-smobs.icc

   1 /*
   2   ly-smobs.icc -- implement smob glue.
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9
  10 #ifndef LY_SMOBS_ICC
  11 #define LY_SMOBS_ICC
  12
  13 #define IMPLEMENT_UNSMOB(CL, name)              \
  14 CL *                                            \
  15 unsmob_ ## name ( SCM s)                        \
  16 {                                               \
  17   if (SMOB_IS_TYPE_B(CL, s))                    \
  18     return SMOB_TO_TYPE(CL, s);                 \
  19   else                                          \
  20     return 0;                                   \
  21 }
  22
  23
  24 #define IMPLEMENT_SMOBS(CL)\
  25 long CL::smob_tag_;\
  26 static scm_smobfuns CL ## _funs = {                                     \
  27   CL::mark_smob, CL::free_smob,                                         \
  28   CL::print_smob, 0,                                                    \
  29 };                                                                      \
  30 void                                                                    \
  31 CL::init_smobs ()                                                       \
  32 {                                                                       \
  33   smob_tag_ = scm_newsmob (&CL ## _funs);                                       \
  34 }                                                                       \
  35                                                                         \
  36                                                                          \
  37 void                                                                     \
  38 CL::unsmobify_self ()                                                    \
  39 {                                                                        \
  40   SCM s = self_scm_;                                                     \
  41   scm_unprotect_object (s);                                              \
  42                                                                          \
  43   SCM_CAR(self_scm_) = SCM_EOL;  \
  44   SCM_CDR(self_scm_) = SCM_EOL;                                          \
  45   self_scm_ = SCM_EOL;                                                   \
  46 }                                                                        \
  47 \
  48 SCM                                                                     \
  49 CL::smobify_self ()                                                     \
  50 {                                                                       \
  51   if (self_scm_ != SCM_EOL)                                             \
  52     return self_scm_;                                                   \
  53                                                                         \
  54   /*                                                                    \
  55     This is local. We don't assign to self_scm_ directly, to assure     \
  56     that S isn't GC-ed from under us.                                   \
  57    */                                                                   \
  58   SCM s;                                                                \
  59                                                                         \
  60   SCM_NEWCELL(s);                                                       \
  61   self_scm_ = s;                                                        \
  62                                                                         \
  63   SCM_SETCAR(s,smob_tag_);                                              \
  64   void * me_p = this;                                                   \
  65   SCM_SETCDR(s,me_p);                                                   \
  66   scm_protect_object (s);                                               \
  67                                                                         \
  68 /* no scm_done_malloc() !  */ \
  69   do_smobify_self();                                                    \
  70   return s;                                     \
  71 }                                               \
  72 scm_sizet                                       \
  73 CL::free_smob (SCM ses)                         \
  74 {                                               \
  75   CL * s = (CL*) SCM_CDR(ses);                  \
  76   /* someone else did the deed already; this might be an automatic var.*/ \
  77   if (s->self_scm_ != ses)\
  78      return 0; \
  79   SCM_CAR(ses) = SCM_EOL;\
  80                                         \
  81   return 0;\
  82 }                                               \
  83 ADD_SCM_INIT_FUNC(CL, CL::init_smobs)\
  84
  85
  86 #endif /* LY_SMOBS_ICC */
  87