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 SCM smobify (CL *cl)\
  23 {\
  24   SCM s;                                                                \
  25                                                                         \
  26   SCM_NEWCELL(s);                                                       \
  27   SCM_SETCAR(s,CL::smob_tag_);                                          \
  28   void * me_p = cl;                                                     \
  29   SCM_SETCDR(s,me_p);                                                   \
  30 return s;\
  31 }\
  32
  33
  34
  35 #define IMPLEMENT_SMOBS(CL)\
  36 long CL::smob_tag_;\
  37 static scm_smobfuns CL ## _funs = {                                     \
  38   CL::mark_smob, CL::free_smob,                                         \
  39   CL::print_smob, 0,                                                    \
  40 };                                                                      \
  41 void                                                                    \
  42 CL::init_smobs ()                                                       \
  43 {                                                                       \
  44   smob_tag_ = scm_newsmob (&CL ## _funs);                                       \
  45 }                                                                       \
  46                                                                         \
  47                                                                          \
  48 void                                                                     \
  49 CL::unsmobify_self ()                                                    \
  50 {                                                                        \
  51   SCM s = self_scm_;                                                     \
  52   scm_unprotect_object (s);                                              \
  53                                                                          \
  54   SCM_CAR(self_scm_) = SCM_EOL;  \
  55   SCM_CDR(self_scm_) = SCM_EOL;                                          \
  56   self_scm_ = SCM_EOL;                                                   \
  57 }                                                                        \
  58 \
  59 SCM                                                                     \
  60 CL::smobify_self ()                                                     \
  61 {                                                                       \
  62   if (self_scm_ != SCM_EOL)                                             \
  63     return self_scm_;                                                   \
  64                                                                         \
  65   /*                                                                    \
  66     This is local. We don't assign to self_scm_ directly, to assure     \
  67     that S isn't GC-ed from under us.                                   \
  68    */                                                                   \
  69   SCM s = smobify (this); \
  70   self_scm_ = s;                                                        \
  71   scm_protect_object (s);                                               \
  72                                                                         \
  73 /* no scm_done_malloc() !  */ \
  74   do_smobify_self();                                                    \
  75   return s;                                     \
  76 }                                               \
  77 scm_sizet                                       \
  78 CL::free_smob (SCM ses)                         \
  79 {                                               \
  80   CL * s = (CL*) SCM_CDR(ses);                  \
  81   /* someone else did the deed already; this might be an automatic var.*/ \
  82   if (s->self_scm_ != ses)\
  83      return 0; \
  84   SCM_CAR(ses) = SCM_EOL;\
  85                                         \
  86   return 0;\
  87 }                                               \
  88 ADD_SCM_INIT_FUNC(CL, CL::init_smobs)\
  89
  90
  91 #endif /* LY_SMOBS_ICC */
  92