libguile/frames.c

   1 /* Copyright (C) 2001, 2009, 2010, 2011, 2012, 2013, 2014 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 #include "vm.h"
  28 #include <verify.h>
  29
  30 /* Make sure assumptions on the layout of `struct scm_vm_frame' hold.  */
  31 verify (sizeof (SCM) == sizeof (SCM *));
  32 verify (sizeof (struct scm_vm_frame) == 3 * sizeof (SCM));
  33 verify (offsetof (struct scm_vm_frame, dynamic_link) == 0);
  34
  35 \f
  36
  37 SCM
  38 scm_c_make_frame (enum scm_vm_frame_kind kind, const struct scm_frame *frame)
  39 {
  40   struct scm_frame *p = scm_gc_malloc (sizeof (struct scm_frame),
  41                                        "vmframe");
  42   p->stack_holder = frame->stack_holder;
  43   p->fp_offset = frame->fp_offset;
  44   p->sp_offset = frame->sp_offset;
  45   p->ip = frame->ip;
  46   return scm_cell (scm_tc7_frame | (kind << 8), (scm_t_bits)p);
  47 }
  48
  49 void
  50 scm_i_frame_print (SCM frame, SCM port, scm_print_state *pstate)
  51 {
  52   scm_puts_unlocked ("#<frame ", port);
  53   scm_uintprint (SCM_UNPACK (frame), 16, port);
  54   scm_putc_unlocked (' ', port);
  55   scm_write (scm_frame_procedure (frame), port);
  56   /* don't write args, they can get us into trouble. */
  57   scm_puts_unlocked (">", port);
  58 }
  59
  60 static SCM*
  61 frame_stack_base (enum scm_vm_frame_kind kind, struct scm_frame *frame)
  62 {
  63   switch (kind)
  64     {
  65       case SCM_VM_FRAME_KIND_CONT:
  66         return ((struct scm_vm_cont *) frame->stack_holder)->stack_base;
  67
  68       case SCM_VM_FRAME_KIND_VM:
  69         return ((struct scm_vm *) frame->stack_holder)->stack_base;
  70
  71       default:
  72         abort ();
  73     }
  74 }
  75
  76 static scm_t_ptrdiff
  77 frame_offset (enum scm_vm_frame_kind kind, struct scm_frame *frame)
  78 {
  79   switch (kind)
  80     {
  81     case SCM_VM_FRAME_KIND_CONT:
  82       return ((struct scm_vm_cont *) frame->stack_holder)->reloc;
  83
  84     case SCM_VM_FRAME_KIND_VM:
  85       return 0;
  86
  87     default:
  88       abort ();
  89     }
  90 }
  91
  92 SCM*
  93 scm_i_frame_stack_base (SCM frame)
  94 #define FUNC_NAME "frame-stack-base"
  95 {
  96   SCM_VALIDATE_VM_FRAME (1, frame);
  97
  98   return frame_stack_base (SCM_VM_FRAME_KIND (frame),
  99                            SCM_VM_FRAME_DATA (frame));
 100 }
 101 #undef FUNC_NAME
 102
 103 scm_t_ptrdiff
 104 scm_i_frame_offset (SCM frame)
 105 #define FUNC_NAME "frame-offset"
 106 {
 107   SCM_VALIDATE_VM_FRAME (1, frame);
 108
 109   return frame_offset (SCM_VM_FRAME_KIND (frame),
 110                        SCM_VM_FRAME_DATA (frame));
 111
 112 }
 113 #undef FUNC_NAME
 114
 115 \f
 116 /* Scheme interface */
 117
 118 SCM_DEFINE (scm_frame_p, "frame?", 1, 0, 0,
 119             (SCM obj),
 120             "")
 121 #define FUNC_NAME s_scm_frame_p
 122 {
 123   return scm_from_bool (SCM_VM_FRAME_P (obj));
 124 }
 125 #undef FUNC_NAME
 126
 127 SCM_DEFINE (scm_frame_procedure, "frame-procedure", 1, 0, 0,
 128             (SCM frame),
 129             "")
 130 #define FUNC_NAME s_scm_frame_procedure
 131 {
 132   SCM_VALIDATE_VM_FRAME (1, frame);
 133   return SCM_FRAME_PROGRAM (SCM_VM_FRAME_FP (frame));
 134 }
 135 #undef FUNC_NAME
 136
 137 static SCM frame_arguments_var;
 138
 139 static void
 140 init_frame_arguments_var (void)
 141 {
 142   frame_arguments_var
 143     = scm_c_private_lookup ("system vm frame", "frame-arguments");
 144 }
 145
 146 SCM_DEFINE (scm_frame_arguments, "frame-arguments", 1, 0, 0,
 147             (SCM frame),
 148             "")
 149 #define FUNC_NAME s_scm_frame_arguments
 150 {
 151   static scm_i_pthread_once_t once = SCM_I_PTHREAD_ONCE_INIT;
 152   scm_i_pthread_once (&once, init_frame_arguments_var);
 153
 154   SCM_VALIDATE_VM_FRAME (1, frame);
 155
 156   return scm_call_1 (scm_variable_ref (frame_arguments_var), frame);
 157 }
 158 #undef FUNC_NAME
 159
 160 SCM_DEFINE (scm_frame_source, "frame-source", 1, 0, 0,
 161             (SCM frame),
 162             "")
 163 #define FUNC_NAME s_scm_frame_source
 164 {
 165   SCM_VALIDATE_VM_FRAME (1, frame);
 166
 167   return scm_find_source_for_addr (scm_frame_instruction_pointer (frame));
 168 }
 169 #undef FUNC_NAME
 170
 171 SCM_DEFINE (scm_frame_num_locals, "frame-num-locals", 1, 0, 0,
 172             (SCM frame),
 173             "")
 174 #define FUNC_NAME s_scm_frame_num_locals
 175 {
 176   SCM *fp, *sp;
 177
 178   SCM_VALIDATE_VM_FRAME (1, frame);
 179
 180   fp = SCM_VM_FRAME_FP (frame);
 181   sp = SCM_VM_FRAME_SP (frame);
 182
 183   return scm_from_ptrdiff_t (SCM_FRAME_NUM_LOCALS (fp, sp));
 184 }
 185 #undef FUNC_NAME
 186
 187 SCM_DEFINE (scm_frame_local_ref, "frame-local-ref", 2, 0, 0,
 188             (SCM frame, SCM index),
 189             "")
 190 #define FUNC_NAME s_scm_frame_local_ref
 191 {
 192   SCM *fp, *sp;
 193   unsigned int i;
 194
 195   SCM_VALIDATE_VM_FRAME (1, frame);
 196   SCM_VALIDATE_UINT_COPY (2, index, i);
 197
 198   fp = SCM_VM_FRAME_FP (frame);
 199   sp = SCM_VM_FRAME_SP (frame);
 200
 201   if (i < SCM_FRAME_NUM_LOCALS (fp, sp))
 202     return SCM_FRAME_LOCAL (fp, i);
 203
 204   SCM_OUT_OF_RANGE (SCM_ARG2, index);
 205 }
 206 #undef FUNC_NAME
 207
 208 /* Need same not-yet-active frame logic here as in frame-num-locals */
 209 SCM_DEFINE (scm_frame_local_set_x, "frame-local-set!", 3, 0, 0,
 210             (SCM frame, SCM index, SCM val),
 211             "")
 212 #define FUNC_NAME s_scm_frame_local_set_x
 213 {
 214   SCM *fp, *sp;
 215   unsigned int i;
 216
 217   SCM_VALIDATE_VM_FRAME (1, frame);
 218   SCM_VALIDATE_UINT_COPY (2, index, i);
 219
 220   fp = SCM_VM_FRAME_FP (frame);
 221   sp = SCM_VM_FRAME_SP (frame);
 222
 223   if (i < SCM_FRAME_NUM_LOCALS (fp, sp))
 224     {
 225       SCM_FRAME_LOCAL (fp, i) = val;
 226       return SCM_UNSPECIFIED;
 227     }
 228
 229   SCM_OUT_OF_RANGE (SCM_ARG2, index);
 230 }
 231 #undef FUNC_NAME
 232
 233 SCM_DEFINE (scm_frame_address, "frame-address", 1, 0, 0,
 234             (SCM frame),
 235             "Return the frame pointer for @var{frame}.")
 236 #define FUNC_NAME s_scm_frame_address
 237 {
 238   SCM_VALIDATE_VM_FRAME (1, frame);
 239   return scm_from_uintptr_t ((scm_t_uintptr) SCM_VM_FRAME_FP (frame));
 240 }
 241 #undef FUNC_NAME
 242
 243 SCM_DEFINE (scm_frame_stack_pointer, "frame-stack-pointer", 1, 0, 0,
 244             (SCM frame),
 245             "")
 246 #define FUNC_NAME s_scm_frame_stack_pointer
 247 {
 248   SCM_VALIDATE_VM_FRAME (1, frame);
 249
 250   return scm_from_uintptr_t ((scm_t_uintptr) SCM_VM_FRAME_SP (frame));
 251 }
 252 #undef FUNC_NAME
 253
 254 SCM_DEFINE (scm_frame_instruction_pointer, "frame-instruction-pointer", 1, 0, 0,
 255             (SCM frame),
 256             "")
 257 #define FUNC_NAME s_scm_frame_instruction_pointer
 258 {
 259   SCM_VALIDATE_VM_FRAME (1, frame);
 260
 261   return scm_from_uintptr_t ((scm_t_uintptr) SCM_VM_FRAME_IP (frame));
 262 }
 263 #undef FUNC_NAME
 264
 265 SCM_DEFINE (scm_frame_return_address, "frame-return-address", 1, 0, 0,
 266             (SCM frame),
 267             "")
 268 #define FUNC_NAME s_scm_frame_return_address
 269 {
 270   SCM_VALIDATE_VM_FRAME (1, frame);
 271   return scm_from_uintptr_t ((scm_t_uintptr) (SCM_FRAME_RETURN_ADDRESS
 272                                               (SCM_VM_FRAME_FP (frame))));
 273 }
 274 #undef FUNC_NAME
 275
 276 #define RELOC(kind, frame, val)                                 \
 277   (((SCM *) (val)) + frame_offset (kind, frame))
 278
 279 SCM_DEFINE (scm_frame_dynamic_link, "frame-dynamic-link", 1, 0, 0,
 280             (SCM frame),
 281             "")
 282 #define FUNC_NAME s_scm_frame_dynamic_link
 283 {
 284   SCM_VALIDATE_VM_FRAME (1, frame);
 285   /* fixme: munge fp if holder is a continuation */
 286   return scm_from_uintptr_t
 287     ((scm_t_uintptr)
 288      RELOC (SCM_VM_FRAME_KIND (frame), SCM_VM_FRAME_DATA (frame),
 289             SCM_FRAME_DYNAMIC_LINK (SCM_VM_FRAME_FP (frame))));
 290 }
 291 #undef FUNC_NAME
 292
 293 int
 294 scm_c_frame_previous (enum scm_vm_frame_kind kind, struct scm_frame *frame)
 295 {
 296   SCM *this_fp, *new_fp, *new_sp;
 297   SCM proc;
 298
 299  again:
 300   this_fp = frame->fp_offset + frame_stack_base (kind, frame);
 301   new_fp = SCM_FRAME_DYNAMIC_LINK (this_fp);
 302   if (new_fp)
 303     {
 304       SCM *stack_base = frame_stack_base (kind, frame);
 305       new_fp = RELOC (kind, frame, new_fp);
 306       new_sp = SCM_FRAME_PREVIOUS_SP (this_fp);
 307       frame->fp_offset = new_fp - stack_base;
 308       frame->sp_offset = new_sp - stack_base;
 309       frame->ip = SCM_FRAME_RETURN_ADDRESS (this_fp);
 310
 311       proc = SCM_FRAME_PROGRAM (new_fp);
 312
 313       if (SCM_PROGRAM_P (proc) && SCM_PROGRAM_IS_BOOT (proc))
 314         goto again;
 315       else
 316         return 1;
 317     }
 318   else
 319     return 0;
 320 }
 321
 322 SCM_DEFINE (scm_frame_previous, "frame-previous", 1, 0, 0,
 323             (SCM frame),
 324             "")
 325 #define FUNC_NAME s_scm_frame_previous
 326 {
 327   enum scm_vm_frame_kind kind;
 328   struct scm_frame tmp;
 329
 330   SCM_VALIDATE_VM_FRAME (1, frame);
 331
 332   kind = SCM_VM_FRAME_KIND (frame);
 333   memcpy (&tmp, SCM_VM_FRAME_DATA (frame), sizeof tmp);
 334
 335   if (!scm_c_frame_previous (SCM_VM_FRAME_KIND (frame), &tmp))
 336     return SCM_BOOL_F;
 337
 338   return scm_c_make_frame (kind, &tmp);
 339 }
 340 #undef FUNC_NAME
 341
 342 \f
 343 void
 344 scm_init_frames (void)
 345 {
 346 #ifndef SCM_MAGIC_SNARFER
 347 #include "libguile/frames.x"
 348 #endif
 349 }
 350
 351 /*
 352   Local Variables:
 353   c-file-style: "gnu"
 354   End:
 355 */