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, const 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, const 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 /* Retrieve the local in slot 0, which may or may not actually be a
 128    procedure, and may or may not actually be the procedure being
 129    applied.  If you want the procedure, look it up from the IP.  */
 130 SCM
 131 scm_c_frame_closure (enum scm_vm_frame_kind kind, const struct scm_frame *frame)
 132 {
 133   SCM *fp = frame_stack_base (kind, frame) + frame->fp_offset;
 134
 135   return SCM_FRAME_PROGRAM (fp);
 136 }
 137
 138 SCM_DEFINE (scm_frame_procedure, "frame-procedure", 1, 0, 0,
 139             (SCM frame),
 140             "")
 141 #define FUNC_NAME s_scm_frame_procedure
 142 {
 143   SCM_VALIDATE_VM_FRAME (1, frame);
 144
 145   /* FIXME: Retrieve procedure from address?  */
 146   return scm_c_frame_closure (SCM_VM_FRAME_KIND (frame),
 147                               SCM_VM_FRAME_DATA (frame));
 148 }
 149 #undef FUNC_NAME
 150
 151 static SCM frame_arguments_var;
 152
 153 static void
 154 init_frame_arguments_var (void)
 155 {
 156   frame_arguments_var
 157     = scm_c_private_lookup ("system vm frame", "frame-arguments");
 158 }
 159
 160 SCM_DEFINE (scm_frame_arguments, "frame-arguments", 1, 0, 0,
 161             (SCM frame),
 162             "")
 163 #define FUNC_NAME s_scm_frame_arguments
 164 {
 165   static scm_i_pthread_once_t once = SCM_I_PTHREAD_ONCE_INIT;
 166   scm_i_pthread_once (&once, init_frame_arguments_var);
 167
 168   SCM_VALIDATE_VM_FRAME (1, frame);
 169
 170   return scm_call_1 (scm_variable_ref (frame_arguments_var), frame);
 171 }
 172 #undef FUNC_NAME
 173
 174 static SCM frame_call_representation_var;
 175
 176 static void
 177 init_frame_call_representation_var (void)
 178 {
 179   frame_call_representation_var
 180     = scm_c_private_lookup ("system vm frame", "frame-call-representation");
 181 }
 182
 183 SCM scm_frame_call_representation (SCM frame)
 184 #define FUNC_NAME "frame-call-representation"
 185 {
 186   static scm_i_pthread_once_t once = SCM_I_PTHREAD_ONCE_INIT;
 187   scm_i_pthread_once (&once, init_frame_call_representation_var);
 188
 189   SCM_VALIDATE_VM_FRAME (1, frame);
 190
 191   return scm_call_1 (scm_variable_ref (frame_call_representation_var), frame);
 192 }
 193 #undef FUNC_NAME
 194
 195 SCM_DEFINE (scm_frame_source, "frame-source", 1, 0, 0,
 196             (SCM frame),
 197             "")
 198 #define FUNC_NAME s_scm_frame_source
 199 {
 200   SCM_VALIDATE_VM_FRAME (1, frame);
 201
 202   return scm_find_source_for_addr (scm_frame_instruction_pointer (frame));
 203 }
 204 #undef FUNC_NAME
 205
 206 SCM_DEFINE (scm_frame_num_locals, "frame-num-locals", 1, 0, 0,
 207             (SCM frame),
 208             "")
 209 #define FUNC_NAME s_scm_frame_num_locals
 210 {
 211   SCM *fp, *sp;
 212
 213   SCM_VALIDATE_VM_FRAME (1, frame);
 214
 215   fp = SCM_VM_FRAME_FP (frame);
 216   sp = SCM_VM_FRAME_SP (frame);
 217
 218   return scm_from_ptrdiff_t (SCM_FRAME_NUM_LOCALS (fp, sp));
 219 }
 220 #undef FUNC_NAME
 221
 222 SCM_DEFINE (scm_frame_local_ref, "frame-local-ref", 2, 0, 0,
 223             (SCM frame, SCM index),
 224             "")
 225 #define FUNC_NAME s_scm_frame_local_ref
 226 {
 227   SCM *fp, *sp;
 228   unsigned int i;
 229
 230   SCM_VALIDATE_VM_FRAME (1, frame);
 231   SCM_VALIDATE_UINT_COPY (2, index, i);
 232
 233   fp = SCM_VM_FRAME_FP (frame);
 234   sp = SCM_VM_FRAME_SP (frame);
 235
 236   if (i < SCM_FRAME_NUM_LOCALS (fp, sp))
 237     return SCM_FRAME_LOCAL (fp, i);
 238
 239   SCM_OUT_OF_RANGE (SCM_ARG2, index);
 240 }
 241 #undef FUNC_NAME
 242
 243 /* Need same not-yet-active frame logic here as in frame-num-locals */
 244 SCM_DEFINE (scm_frame_local_set_x, "frame-local-set!", 3, 0, 0,
 245             (SCM frame, SCM index, SCM val),
 246             "")
 247 #define FUNC_NAME s_scm_frame_local_set_x
 248 {
 249   SCM *fp, *sp;
 250   unsigned int i;
 251
 252   SCM_VALIDATE_VM_FRAME (1, frame);
 253   SCM_VALIDATE_UINT_COPY (2, index, i);
 254
 255   fp = SCM_VM_FRAME_FP (frame);
 256   sp = SCM_VM_FRAME_SP (frame);
 257
 258   if (i < SCM_FRAME_NUM_LOCALS (fp, sp))
 259     {
 260       SCM_FRAME_LOCAL (fp, i) = val;
 261       return SCM_UNSPECIFIED;
 262     }
 263
 264   SCM_OUT_OF_RANGE (SCM_ARG2, index);
 265 }
 266 #undef FUNC_NAME
 267
 268 SCM_DEFINE (scm_frame_address, "frame-address", 1, 0, 0,
 269             (SCM frame),
 270             "Return the frame pointer for @var{frame}.")
 271 #define FUNC_NAME s_scm_frame_address
 272 {
 273   SCM_VALIDATE_VM_FRAME (1, frame);
 274   return scm_from_uintptr_t ((scm_t_uintptr) SCM_VM_FRAME_FP (frame));
 275 }
 276 #undef FUNC_NAME
 277
 278 SCM_DEFINE (scm_frame_stack_pointer, "frame-stack-pointer", 1, 0, 0,
 279             (SCM frame),
 280             "")
 281 #define FUNC_NAME s_scm_frame_stack_pointer
 282 {
 283   SCM_VALIDATE_VM_FRAME (1, frame);
 284
 285   return scm_from_uintptr_t ((scm_t_uintptr) SCM_VM_FRAME_SP (frame));
 286 }
 287 #undef FUNC_NAME
 288
 289 SCM_DEFINE (scm_frame_instruction_pointer, "frame-instruction-pointer", 1, 0, 0,
 290             (SCM frame),
 291             "")
 292 #define FUNC_NAME s_scm_frame_instruction_pointer
 293 {
 294   SCM_VALIDATE_VM_FRAME (1, frame);
 295
 296   return scm_from_uintptr_t ((scm_t_uintptr) SCM_VM_FRAME_IP (frame));
 297 }
 298 #undef FUNC_NAME
 299
 300 SCM_DEFINE (scm_frame_return_address, "frame-return-address", 1, 0, 0,
 301             (SCM frame),
 302             "")
 303 #define FUNC_NAME s_scm_frame_return_address
 304 {
 305   SCM_VALIDATE_VM_FRAME (1, frame);
 306   return scm_from_uintptr_t ((scm_t_uintptr) (SCM_FRAME_RETURN_ADDRESS
 307                                               (SCM_VM_FRAME_FP (frame))));
 308 }
 309 #undef FUNC_NAME
 310
 311 #define RELOC(kind, frame, val)                                 \
 312   (((SCM *) (val)) + frame_offset (kind, frame))
 313
 314 SCM_DEFINE (scm_frame_dynamic_link, "frame-dynamic-link", 1, 0, 0,
 315             (SCM frame),
 316             "")
 317 #define FUNC_NAME s_scm_frame_dynamic_link
 318 {
 319   SCM_VALIDATE_VM_FRAME (1, frame);
 320   /* fixme: munge fp if holder is a continuation */
 321   return scm_from_uintptr_t
 322     ((scm_t_uintptr)
 323      RELOC (SCM_VM_FRAME_KIND (frame), SCM_VM_FRAME_DATA (frame),
 324             SCM_FRAME_DYNAMIC_LINK (SCM_VM_FRAME_FP (frame))));
 325 }
 326 #undef FUNC_NAME
 327
 328 int
 329 scm_c_frame_previous (enum scm_vm_frame_kind kind, struct scm_frame *frame)
 330 {
 331   SCM *this_fp, *new_fp, *new_sp;
 332   SCM proc;
 333
 334  again:
 335   this_fp = frame->fp_offset + frame_stack_base (kind, frame);
 336   new_fp = SCM_FRAME_DYNAMIC_LINK (this_fp);
 337   if (new_fp)
 338     {
 339       SCM *stack_base = frame_stack_base (kind, frame);
 340       new_fp = RELOC (kind, frame, new_fp);
 341       new_sp = SCM_FRAME_PREVIOUS_SP (this_fp);
 342       frame->fp_offset = new_fp - stack_base;
 343       frame->sp_offset = new_sp - stack_base;
 344       frame->ip = SCM_FRAME_RETURN_ADDRESS (this_fp);
 345
 346       proc = SCM_FRAME_PROGRAM (new_fp);
 347
 348       if (SCM_PROGRAM_P (proc) && SCM_PROGRAM_IS_BOOT (proc))
 349         goto again;
 350       else
 351         return 1;
 352     }
 353   else
 354     return 0;
 355 }
 356
 357 SCM_DEFINE (scm_frame_previous, "frame-previous", 1, 0, 0,
 358             (SCM frame),
 359             "")
 360 #define FUNC_NAME s_scm_frame_previous
 361 {
 362   enum scm_vm_frame_kind kind;
 363   struct scm_frame tmp;
 364
 365   SCM_VALIDATE_VM_FRAME (1, frame);
 366
 367   kind = SCM_VM_FRAME_KIND (frame);
 368   memcpy (&tmp, SCM_VM_FRAME_DATA (frame), sizeof tmp);
 369
 370   if (!scm_c_frame_previous (SCM_VM_FRAME_KIND (frame), &tmp))
 371     return SCM_BOOL_F;
 372
 373   return scm_c_make_frame (kind, &tmp);
 374 }
 375 #undef FUNC_NAME
 376
 377 \f
 378 void
 379 scm_init_frames (void)
 380 {
 381 #ifndef SCM_MAGIC_SNARFER
 382 #include "libguile/frames.x"
 383 #endif
 384 }
 385
 386 /*
 387   Local Variables:
 388   c-file-style: "gnu"
 389   End:
 390 */