libguile/frames.h

   1 /* Copyright (C) 2001 Free Software Foundation, Inc.
   2  * *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library 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 GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #ifndef _SCM_FRAMES_H_
  19 #define _SCM_FRAMES_H_
  20
  21 #include <libguile.h>
  22 #include "programs.h"
  23
  24 \f
  25 /*
  26  * VM frames
  27  */
  28
  29 /* VM Frame Layout
  30    ---------------
  31
  32    |                  | <- fp + bp->nargs + bp->nlocs + 4
  33    +------------------+    = SCM_FRAME_UPPER_ADDRESS (fp)
  34    | Return address   |
  35    | MV return address|
  36    | Dynamic link     |
  37    | External link    | <- fp + bp->nargs + bp->nlocs
  38    | Local variable 1 |    = SCM_FRAME_DATA_ADDRESS (fp)
  39    | Local variable 0 | <- fp + bp->nargs
  40    | Argument 1       |
  41    | Argument 0       | <- fp
  42    | Program          | <- fp - 1
  43    +------------------+    = SCM_FRAME_LOWER_ADDRESS (fp)
  44    |                  |
  45
  46    As can be inferred from this drawing, it is assumed that
  47    `sizeof (SCM *) == sizeof (SCM)', since pointers (the `link' parts) are
  48    assumed to be as long as SCM objects.  */
  49
  50 #define SCM_FRAME_DATA_ADDRESS(fp)                              \
  51   (fp + SCM_PROGRAM_DATA (SCM_FRAME_PROGRAM (fp))->nargs        \
  52       + SCM_PROGRAM_DATA (SCM_FRAME_PROGRAM (fp))->nlocs)
  53 #define SCM_FRAME_UPPER_ADDRESS(fp)     (SCM_FRAME_DATA_ADDRESS (fp) + 4)
  54 #define SCM_FRAME_LOWER_ADDRESS(fp)     (fp - 1)
  55
  56 #define SCM_FRAME_BYTE_CAST(x)          ((scm_byte_t *) SCM_UNPACK (x))
  57 #define SCM_FRAME_STACK_CAST(x)         ((SCM *) SCM_UNPACK (x))
  58
  59 #define SCM_FRAME_RETURN_ADDRESS(fp)                            \
  60   (SCM_FRAME_BYTE_CAST (SCM_FRAME_DATA_ADDRESS (fp)[3]))
  61 #define SCM_FRAME_MV_RETURN_ADDRESS(fp)                         \
  62   (SCM_FRAME_BYTE_CAST (SCM_FRAME_DATA_ADDRESS (fp)[2]))
  63 #define SCM_FRAME_DYNAMIC_LINK(fp)                              \
  64   (SCM_FRAME_STACK_CAST (SCM_FRAME_DATA_ADDRESS (fp)[1]))
  65 #define SCM_FRAME_SET_DYNAMIC_LINK(fp, dl)              \
  66   ((SCM_FRAME_DATA_ADDRESS (fp)[1])) = (SCM)(dl);
  67 #define SCM_FRAME_EXTERNAL_LINK(fp)     (SCM_FRAME_DATA_ADDRESS (fp)[0])
  68 #define SCM_FRAME_VARIABLE(fp,i)        fp[i]
  69 #define SCM_FRAME_PROGRAM(fp)           fp[-1]
  70
  71 \f
  72 /*
  73  * Heap frames
  74  */
  75
  76 SCM_API scm_t_bits scm_tc16_vm_frame;
  77
  78 struct scm_vm_frame
  79 {
  80   SCM stack_holder;
  81   SCM *fp;
  82   SCM *sp;
  83   scm_byte_t *ip;
  84   scm_t_ptrdiff offset;
  85 };
  86
  87 #define SCM_VM_FRAME_P(x)       SCM_SMOB_PREDICATE (scm_tc16_vm_frame, x)
  88 #define SCM_VM_FRAME_DATA(x)    ((struct scm_vm_frame*)SCM_SMOB_DATA (x))
  89 #define SCM_VM_FRAME_STACK_HOLDER(f)    SCM_VM_FRAME_DATA(f)->stack_holder
  90 #define SCM_VM_FRAME_FP(f)      SCM_VM_FRAME_DATA(f)->fp
  91 #define SCM_VM_FRAME_SP(f)      SCM_VM_FRAME_DATA(f)->sp
  92 #define SCM_VM_FRAME_IP(f)      SCM_VM_FRAME_DATA(f)->ip
  93 #define SCM_VM_FRAME_OFFSET(f)  SCM_VM_FRAME_DATA(f)->offset
  94 #define SCM_VALIDATE_VM_FRAME(p,x)      SCM_MAKE_VALIDATE (p, x, VM_FRAME_P)
  95
  96 /* FIXME rename scm_byte_t */
  97 SCM_API SCM scm_c_make_vm_frame (SCM stack_holder, SCM *fp, SCM *sp,
  98                                 scm_byte_t *ip, scm_t_ptrdiff offset);
  99 SCM_API SCM scm_vm_frame_p (SCM obj);
 100 SCM_API SCM scm_vm_frame_program (SCM frame);
 101 SCM_API SCM scm_vm_frame_arguments (SCM frame);
 102 SCM_API SCM scm_vm_frame_source (SCM frame);
 103 SCM_API SCM scm_vm_frame_local_ref (SCM frame, SCM index);
 104 SCM_API SCM scm_vm_frame_local_set_x (SCM frame, SCM index, SCM val);
 105 SCM_API SCM scm_vm_frame_return_address (SCM frame);
 106 SCM_API SCM scm_vm_frame_mv_return_address (SCM frame);
 107 SCM_API SCM scm_vm_frame_dynamic_link (SCM frame);
 108 SCM_API SCM scm_vm_frame_external_link (SCM frame);
 109 SCM_API SCM scm_vm_frame_stack (SCM frame);
 110
 111 SCM_API SCM scm_c_vm_frame_prev (SCM frame);
 112
 113 SCM_INTERNAL void scm_bootstrap_frames (void);
 114 SCM_INTERNAL void scm_init_frames (void);
 115
 116 #endif /* _SCM_FRAMES_H_ */
 117
 118 /*
 119   Local Variables:
 120   c-file-style: "gnu"
 121   End:
 122 */