libguile/frames.c

   1 /* Copyright (C) 2001, 2009, 2010, 2011 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 License
   5  * as published by the Free Software Foundation; either version 3 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful, but
   9  * 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
  16  * 02110-1301 USA
  17  */
  18
  19 #if HAVE_CONFIG_H
  20 #  include <config.h>
  21 #endif
  22
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include "_scm.h"
  26 #include "frames.h"
  27
  28 \f
  29 #define RELOC(frame, val) (val + SCM_VM_FRAME_OFFSET (frame))
  30
  31 SCM
  32 scm_c_make_frame (SCM stack_holder, SCM *fp, SCM *sp,
  33                   scm_t_uint8 *ip, scm_t_ptrdiff offset)
  34 {
  35   struct scm_frame *p = scm_gc_malloc (sizeof (struct scm_frame),
  36                                        "vmframe");
  37   p->stack_holder = stack_holder;
  38   p->fp = fp;
  39   p->sp = sp;
  40   p->ip = ip;
  41   p->offset = offset;
  42   return scm_cell (scm_tc7_frame, (scm_t_bits)p);
  43 }
  44
  45 void
  46 scm_i_frame_print (SCM frame, SCM port, scm_print_state *pstate)
  47 {
  48   scm_puts ("#<frame ", port);
  49   scm_uintprint (SCM_UNPACK (frame), 16, port);
  50   scm_putc (' ', port);
  51   scm_write (scm_frame_procedure (frame), port);
  52   /* don't write args, they can get us into trouble. */
  53   scm_puts (">", port);
  54 }
  55
  56 \f
  57 /* Scheme interface */
  58
  59 SCM_DEFINE (scm_frame_p, "frame?", 1, 0, 0,
  60             (SCM obj),
  61             "")
  62 #define FUNC_NAME s_scm_frame_p
  63 {
  64   return scm_from_bool (SCM_VM_FRAME_P (obj));
  65 }
  66 #undef FUNC_NAME
  67
  68 SCM_DEFINE (scm_frame_procedure, "frame-procedure", 1, 0, 0,
  69             (SCM frame),
  70             "")
  71 #define FUNC_NAME s_scm_frame_procedure
  72 {
  73   SCM_VALIDATE_VM_FRAME (1, frame);
  74   return SCM_FRAME_PROGRAM (SCM_VM_FRAME_FP (frame));
  75 }
  76 #undef FUNC_NAME
  77
  78 SCM_DEFINE (scm_frame_arguments, "frame-arguments", 1, 0, 0,
  79             (SCM frame),
  80             "")
  81 #define FUNC_NAME s_scm_frame_arguments
  82 {
  83   static SCM var = SCM_BOOL_F;
  84
  85   SCM_VALIDATE_VM_FRAME (1, frame);
  86
  87   if (scm_is_false (var))
  88     var = scm_c_module_lookup (scm_c_resolve_module ("system vm frame"),
  89                                "frame-arguments");
  90
  91   return scm_call_1 (SCM_VARIABLE_REF (var), frame);
  92 }
  93 #undef FUNC_NAME
  94
  95 SCM_DEFINE (scm_frame_source, "frame-source", 1, 0, 0,
  96             (SCM frame),
  97             "")
  98 #define FUNC_NAME s_scm_frame_source
  99 {
 100   SCM_VALIDATE_VM_FRAME (1, frame);
 101
 102   return scm_program_source (scm_frame_procedure (frame),
 103                              scm_frame_instruction_pointer (frame),
 104                              SCM_UNDEFINED);
 105 }
 106 #undef FUNC_NAME
 107
 108 /* The number of locals would be a simple thing to compute, if it weren't for
 109    the presence of not-yet-active frames on the stack. So we have a cheap
 110    heuristic to detect not-yet-active frames, and skip over them. Perhaps we
 111    should represent them more usefully.
 112 */
 113 SCM_DEFINE (scm_frame_num_locals, "frame-num-locals", 1, 0, 0,
 114             (SCM frame),
 115             "")
 116 #define FUNC_NAME s_scm_frame_num_locals
 117 {
 118   SCM *sp, *p;
 119   unsigned int n = 0;
 120
 121   SCM_VALIDATE_VM_FRAME (1, frame);
 122
 123   sp = SCM_VM_FRAME_SP (frame);
 124   p = SCM_FRAME_STACK_ADDRESS (SCM_VM_FRAME_FP (frame));
 125   while (p <= sp)
 126     {
 127       if (SCM_UNPACK (p[0]) == 0)
 128         /* skip over not-yet-active frame */
 129         p += 3;
 130       else
 131         {
 132           p++;
 133           n++;
 134         }
 135     }
 136   return scm_from_uint (n);
 137 }
 138 #undef FUNC_NAME
 139
 140 /* Need same not-yet-active frame logic here as in frame-num-locals */
 141 SCM_DEFINE (scm_frame_local_ref, "frame-local-ref", 2, 0, 0,
 142             (SCM frame, SCM index),
 143             "")
 144 #define FUNC_NAME s_scm_frame_local_ref
 145 {
 146   SCM *sp, *p;
 147   unsigned int n = 0;
 148   unsigned int i;
 149
 150   SCM_VALIDATE_VM_FRAME (1, frame);
 151   SCM_VALIDATE_UINT_COPY (2, index, i);
 152
 153   sp = SCM_VM_FRAME_SP (frame);
 154   p = SCM_FRAME_STACK_ADDRESS (SCM_VM_FRAME_FP (frame));
 155   while (p <= sp)
 156     {
 157       if (SCM_UNPACK (p[0]) == 0)
 158         /* skip over not-yet-active frame */
 159         p += 3;
 160       else if (n == i)
 161         return *p;
 162       else
 163         {
 164           p++;
 165           n++;
 166         }
 167     }
 168   SCM_OUT_OF_RANGE (SCM_ARG2, index);
 169 }
 170 #undef FUNC_NAME
 171
 172 /* Need same not-yet-active frame logic here as in frame-num-locals */
 173 SCM_DEFINE (scm_frame_local_set_x, "frame-local-set!", 3, 0, 0,
 174             (SCM frame, SCM index, SCM val),
 175             "")
 176 #define FUNC_NAME s_scm_frame_local_set_x
 177 {
 178   SCM *sp, *p;
 179   unsigned int n = 0;
 180   unsigned int i;
 181
 182   SCM_VALIDATE_VM_FRAME (1, frame);
 183   SCM_VALIDATE_UINT_COPY (2, index, i);
 184
 185   sp = SCM_VM_FRAME_SP (frame);
 186   p = SCM_FRAME_STACK_ADDRESS (SCM_VM_FRAME_FP (frame));
 187   while (p <= sp)
 188     {
 189       if (SCM_UNPACK (p[0]) == 0)
 190         /* skip over not-yet-active frame */
 191         p += 3;
 192       else if (n == i)
 193         {
 194           *p = val;
 195           return SCM_UNSPECIFIED;
 196         }
 197       else
 198         {
 199           p++;
 200           n++;
 201         }
 202     }
 203   SCM_OUT_OF_RANGE (SCM_ARG2, index);
 204 }
 205 #undef FUNC_NAME
 206
 207 SCM_DEFINE (scm_frame_address, "frame-address", 1, 0, 0,
 208             (SCM frame),
 209             "Return the frame pointer for @var{frame}.")
 210 #define FUNC_NAME s_scm_frame_address
 211 {
 212   SCM_VALIDATE_VM_FRAME (1, frame);
 213   return scm_from_unsigned_integer ((scm_t_bits) SCM_VM_FRAME_FP (frame));
 214 }
 215 #undef FUNC_NAME
 216
 217 SCM_DEFINE (scm_frame_stack_pointer, "frame-stack-pointer", 1, 0, 0,
 218             (SCM frame),
 219             "")
 220 #define FUNC_NAME s_scm_frame_stack_pointer
 221 {
 222   SCM_VALIDATE_VM_FRAME (1, frame);
 223
 224   return scm_from_unsigned_integer ((scm_t_bits) SCM_VM_FRAME_SP (frame));
 225 }
 226 #undef FUNC_NAME
 227
 228 SCM_DEFINE (scm_frame_instruction_pointer, "frame-instruction-pointer", 1, 0, 0,
 229             (SCM frame),
 230             "")
 231 #define FUNC_NAME s_scm_frame_instruction_pointer
 232 {
 233   const struct scm_objcode *c_objcode;
 234
 235   SCM_VALIDATE_VM_FRAME (1, frame);
 236
 237   c_objcode = SCM_PROGRAM_DATA (scm_frame_procedure (frame));
 238   return scm_from_unsigned_integer ((SCM_VM_FRAME_IP (frame)
 239                                      - SCM_C_OBJCODE_BASE (c_objcode)));
 240 }
 241 #undef FUNC_NAME
 242
 243 SCM_DEFINE (scm_frame_return_address, "frame-return-address", 1, 0, 0,
 244             (SCM frame),
 245             "")
 246 #define FUNC_NAME s_scm_frame_return_address
 247 {
 248   SCM_VALIDATE_VM_FRAME (1, frame);
 249   return scm_from_unsigned_integer ((scm_t_bits)
 250                                     (SCM_FRAME_RETURN_ADDRESS
 251                                      (SCM_VM_FRAME_FP (frame))));
 252 }
 253 #undef FUNC_NAME
 254
 255 SCM_DEFINE (scm_frame_mv_return_address, "frame-mv-return-address", 1, 0, 0,
 256             (SCM frame),
 257             "")
 258 #define FUNC_NAME s_scm_frame_mv_return_address
 259 {
 260   SCM_VALIDATE_VM_FRAME (1, frame);
 261   return scm_from_unsigned_integer ((scm_t_bits)
 262                                     (SCM_FRAME_MV_RETURN_ADDRESS
 263                                      (SCM_VM_FRAME_FP (frame))));
 264 }
 265 #undef FUNC_NAME
 266
 267 SCM_DEFINE (scm_frame_dynamic_link, "frame-dynamic-link", 1, 0, 0,
 268             (SCM frame),
 269             "")
 270 #define FUNC_NAME s_scm_frame_dynamic_link
 271 {
 272   SCM_VALIDATE_VM_FRAME (1, frame);
 273   /* fixme: munge fp if holder is a continuation */
 274   return scm_from_ulong
 275     ((unsigned long)
 276      RELOC (frame,
 277             SCM_FRAME_DYNAMIC_LINK (SCM_VM_FRAME_FP (frame))));
 278 }
 279 #undef FUNC_NAME
 280
 281 SCM_DEFINE (scm_frame_previous, "frame-previous", 1, 0, 0,
 282             (SCM frame),
 283             "")
 284 #define FUNC_NAME s_scm_frame_previous
 285 {
 286   SCM *this_fp, *new_fp, *new_sp;
 287
 288   SCM_VALIDATE_VM_FRAME (1, frame);
 289
 290  again:
 291   this_fp = SCM_VM_FRAME_FP (frame);
 292   new_fp = SCM_FRAME_DYNAMIC_LINK (this_fp);
 293   if (new_fp)
 294     { new_fp = RELOC (frame, new_fp);
 295       new_sp = SCM_FRAME_LOWER_ADDRESS (this_fp) - 1;
 296       frame = scm_c_make_frame (SCM_VM_FRAME_STACK_HOLDER (frame),
 297                                 new_fp, new_sp,
 298                                 SCM_FRAME_RETURN_ADDRESS (this_fp),
 299                                 SCM_VM_FRAME_OFFSET (frame));
 300       if (SCM_PROGRAM_IS_BOOT (scm_frame_procedure (frame)))
 301         goto again;
 302       else
 303         return frame;
 304     }
 305   else
 306     return SCM_BOOL_F;
 307 }
 308 #undef FUNC_NAME
 309
 310 \f
 311 void
 312 scm_init_frames (void)
 313 {
 314 #ifndef SCM_MAGIC_SNARFER
 315 #include "libguile/frames.x"
 316 #endif
 317 }
 318
 319 /*
 320   Local Variables:
 321   c-file-style: "gnu"
 322   End:
 323 */