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--2000 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   should include equal_p ?
  36  */
  37 #define IMPLEMENT_SMOBS(CL)\
  38 long CL::smob_tag_;\
  39 static scm_smobfuns CL ## _funs = {                                     \
  40   CL::mark_smob, CL::free_smob,                                         \
  41   CL::print_smob, 0,                                                    \
  42 };                                                                      \
  43 void                                                                    \
  44 CL::init_smobs ()                                                       \
  45 {                                                                       \
  46   smob_tag_ = scm_newsmob (&CL ## _funs);                                       \
  47 }                                                                       \
  48                                                                         \
  49                                                                          \
  50 void                                                                     \
  51 CL::unsmobify_self ()                                                    \
  52 {                                                                        \
  53   SCM s = self_scm_;                                                     \
  54   scm_unprotect_object (s);                                              \
  55                                                                          \
  56   SCM_CAR(self_scm_) = SCM_EOL;  \
  57   SCM_CDR(self_scm_) = SCM_EOL;                                          \
  58   self_scm_ = SCM_EOL;                                                   \
  59 }                                                                        \
  60 \
  61 SCM                                                                     \
  62 CL::smobify_self ()                                                     \
  63 {                                                                       \
  64   if (self_scm_ != SCM_EOL)                                             \
  65     return self_scm_;                                                   \
  66                                                                         \
  67   /*                                                                    \
  68     This is local. We don't assign to self_scm_ directly, to assure     \
  69     that S isn't GC-ed from under us.                                   \
  70    */                                                                   \
  71   SCM s = smobify (this); \
  72   self_scm_ = s;                                                        \
  73   scm_protect_object (s);                                               \
  74                                                                         \
  75 /* no scm_done_malloc() !  */ \
  76   do_smobify_self();                                                    \
  77   return s;                                     \
  78 }                                               \
  79 scm_sizet                                       \
  80 CL::free_smob (SCM ses)                         \
  81 {                                               \
  82   CL * s = (CL*) SCM_CDR(ses);                  \
  83   /* someone else did the deed already; this might be an automatic var.*/ \
  84   if (s->self_scm_ != ses)\
  85      return 0; \
  86   SCM_CAR(ses) = SCM_EOL;\
  87                                         \
  88   return 0;\
  89 }                                               \
  90 ADD_SCM_INIT_FUNC(CL, CL::init_smobs)\
  91
  92
  93 #endif /* LY_SMOBS_ICC */
  94