src/frames.h

   1 /* Copyright (C) 2001 Free Software Foundation, Inc.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this software; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  16  * Boston, MA 02111-1307 USA
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  21  * The exception is that, if you link the GUILE library with other files
  22  * to produce an executable, this does not by itself cause the
  23  * resulting executable to be covered by the GNU General Public License.
  24  * Your use of that executable is in no way restricted on account of
  25  * linking the GUILE library code into it.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  30  * This exception applies only to the code released by the
  31  * Free Software Foundation under the name GUILE.  If you copy
  32  * code from other Free Software Foundation releases into a copy of
  33  * GUILE, as the General Public License permits, the exception does
  34  * not apply to the code that you add in this way.  To avoid misleading
  35  * anyone as to the status of such modified files, you must delete
  36  * this exception notice from them.
  37  *
  38  * If you write modifications of your own for GUILE, it is your choice
  39  * whether to permit this exception to apply to your modifications.
  40  * If you do not wish that, delete this exception notice.  */
  41
  42 #ifndef _SCM_FRAMES_H_
  43 #define _SCM_FRAMES_H_
  44
  45 #include <libguile.h>
  46 #include "config.h"
  47 #include "programs.h"
  48
  49 \f
  50 /*
  51  * VM frames
  52  */
  53
  54 /* VM Frame Layout
  55    ---------------
  56
  57    |                  | <- fp + bp->nargs + bp->nlocs + 4
  58    +------------------+    = SCM_FRAME_UPPER_ADDRESS (fp)
  59    | Return address   |
  60    | Dynamic link     |
  61    | Heap link        |
  62    | External link    | <- fp + bp->nargs + bp->nlocs
  63    | Local variable 1 |    = SCM_FRAME_DATA_ADDRESS (fp)
  64    | Local variable 0 | <- fp + bp->nargs
  65    | Argument 1       |
  66    | Argument 0       | <- fp
  67    | Program          | <- fp - 1
  68    +------------------+    = SCM_FRAME_LOWER_ADDRESS (fp)
  69    |                  |
  70
  71    As can be inferred from this drawing, it is assumed that
  72    `sizeof (SCM *) == sizeof (SCM)', since pointers (the `link' parts) are
  73    assumed to be as long as SCM objects.  */
  74
  75 #define SCM_FRAME_DATA_ADDRESS(fp)                              \
  76   (fp + SCM_PROGRAM_DATA (SCM_FRAME_PROGRAM (fp))->nargs        \
  77       + SCM_PROGRAM_DATA (SCM_FRAME_PROGRAM (fp))->nlocs)
  78 #define SCM_FRAME_UPPER_ADDRESS(fp)     (SCM_FRAME_DATA_ADDRESS (fp) + 4)
  79 #define SCM_FRAME_LOWER_ADDRESS(fp)     (fp - 1)
  80
  81 #define SCM_FRAME_BYTE_CAST(x)          ((scm_byte_t *) SCM_UNPACK (x))
  82 #define SCM_FRAME_STACK_CAST(x)         ((SCM *) SCM_UNPACK (x))
  83
  84 #define SCM_FRAME_RETURN_ADDRESS(fp)                            \
  85   (SCM_FRAME_BYTE_CAST (SCM_FRAME_DATA_ADDRESS (fp)[3]))
  86 #define SCM_FRAME_DYNAMIC_LINK(fp)                              \
  87   (SCM_FRAME_STACK_CAST (SCM_FRAME_DATA_ADDRESS (fp)[2]))
  88 #define SCM_FRAME_SET_DYNAMIC_LINK(fp, dl)              \
  89   ((SCM_FRAME_DATA_ADDRESS (fp)[2])) = (SCM)(dl);
  90 #define SCM_FRAME_HEAP_LINK(fp)         (SCM_FRAME_DATA_ADDRESS (fp)[1])
  91 #define SCM_FRAME_EXTERNAL_LINK(fp)     (SCM_FRAME_DATA_ADDRESS (fp)[0])
  92 #define SCM_FRAME_VARIABLE(fp,i)        fp[i]
  93 #define SCM_FRAME_PROGRAM(fp)           fp[-1]
  94
  95 \f
  96 /*
  97  * Heap frames
  98  */
  99
 100 extern scm_t_bits scm_tc16_heap_frame;
 101
 102 #define SCM_HEAP_FRAME_P(x)     SCM_SMOB_PREDICATE (scm_tc16_heap_frame, x)
 103 #define SCM_HEAP_FRAME_DATA(f)          ((SCM *) SCM_SMOB_DATA (f))
 104 #define SCM_HEAP_FRAME_SELF(f)          (SCM_HEAP_FRAME_DATA (f) + 0)
 105 #define SCM_HEAP_FRAME_POINTER(f)       (SCM_HEAP_FRAME_DATA (f) + 2)
 106 #define SCM_VALIDATE_HEAP_FRAME(p,x)    SCM_MAKE_VALIDATE (p, x, HEAP_FRAME_P)
 107
 108 extern SCM scm_c_make_heap_frame (SCM *fp);
 109 extern void scm_init_frames (void);
 110
 111 #endif /* _SCM_FRAMES_H_ */
 112
 113 /*
 114   Local Variables:
 115   c-file-style: "gnu"
 116   End:
 117 */