xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/guile/scm-math.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /* GDB/Scheme support for math operations on values.
2 
3    Copyright (C) 2008-2019 Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19 
20 /* See README file in this directory for implementation notes, coding
21    conventions, et.al.  */
22 
23 #include "defs.h"
24 #include "arch-utils.h"
25 #include "charset.h"
26 #include "cp-abi.h"
27 #include "target-float.h"
28 #include "symtab.h" /* Needed by language.h.  */
29 #include "language.h"
30 #include "valprint.h"
31 #include "value.h"
32 #include "guile-internal.h"
33 
34 /* Note: Use target types here to remain consistent with the values system in
35    GDB (which uses target arithmetic).  */
36 
37 enum valscm_unary_opcode
38 {
39   VALSCM_NOT,
40   VALSCM_NEG,
41   VALSCM_NOP,
42   VALSCM_ABS,
43   /* Note: This is Scheme's "logical not", not GDB's.
44      GDB calls this UNOP_COMPLEMENT.  */
45   VALSCM_LOGNOT
46 };
47 
48 enum valscm_binary_opcode
49 {
50   VALSCM_ADD,
51   VALSCM_SUB,
52   VALSCM_MUL,
53   VALSCM_DIV,
54   VALSCM_REM,
55   VALSCM_MOD,
56   VALSCM_POW,
57   VALSCM_LSH,
58   VALSCM_RSH,
59   VALSCM_MIN,
60   VALSCM_MAX,
61   VALSCM_BITAND,
62   VALSCM_BITOR,
63   VALSCM_BITXOR
64 };
65 
66 /* If TYPE is a reference, return the target; otherwise return TYPE.  */
67 #define STRIP_REFERENCE(TYPE) \
68   ((TYPE_CODE (TYPE) == TYPE_CODE_REF) ? (TYPE_TARGET_TYPE (TYPE)) : (TYPE))
69 
70 /* Helper for vlscm_unop.  Contains all the code that may throw a GDB
71    exception.  */
72 
73 static SCM
74 vlscm_unop_gdbthrow (enum valscm_unary_opcode opcode, SCM x,
75 		     const char *func_name)
76 {
77   struct gdbarch *gdbarch = get_current_arch ();
78   const struct language_defn *language = current_language;
79 
80   scoped_value_mark free_values;
81 
82   SCM except_scm;
83   value *arg1 = vlscm_convert_value_from_scheme (func_name, SCM_ARG1, x,
84 						 &except_scm, gdbarch,
85 						 language);
86   if (arg1 == NULL)
87     return except_scm;
88 
89   struct value *res_val = NULL;
90 
91   switch (opcode)
92     {
93     case VALSCM_NOT:
94       /* Alas gdb and guile use the opposite meaning for "logical
95 	 not".  */
96       {
97 	struct type *type = language_bool_type (language, gdbarch);
98 	res_val
99 	  = value_from_longest (type,
100 				(LONGEST) value_logical_not (arg1));
101       }
102       break;
103     case VALSCM_NEG:
104       res_val = value_neg (arg1);
105       break;
106     case VALSCM_NOP:
107       /* Seemingly a no-op, but if X was a Scheme value it is now a
108 	 <gdb:value> object.  */
109       res_val = arg1;
110       break;
111     case VALSCM_ABS:
112       if (value_less (arg1, value_zero (value_type (arg1), not_lval)))
113 	res_val = value_neg (arg1);
114       else
115 	res_val = arg1;
116       break;
117     case VALSCM_LOGNOT:
118       res_val = value_complement (arg1);
119       break;
120     default:
121       gdb_assert_not_reached ("unsupported operation");
122     }
123 
124   gdb_assert (res_val != NULL);
125   return vlscm_scm_from_value (res_val);
126 }
127 
128 static SCM
129 vlscm_unop (enum valscm_unary_opcode opcode, SCM x, const char *func_name)
130 {
131   return gdbscm_wrap (vlscm_unop_gdbthrow, opcode, x, func_name);
132 }
133 
134 /* Helper for vlscm_binop.  Contains all the code that may throw a GDB
135    exception.  */
136 
137 static SCM
138 vlscm_binop_gdbthrow (enum valscm_binary_opcode opcode, SCM x, SCM y,
139 		      const char *func_name)
140 {
141   struct gdbarch *gdbarch = get_current_arch ();
142   const struct language_defn *language = current_language;
143   struct value *arg1, *arg2;
144   struct value *res_val = NULL;
145   SCM except_scm;
146 
147   scoped_value_mark free_values;
148 
149   arg1 = vlscm_convert_value_from_scheme (func_name, SCM_ARG1, x,
150 					  &except_scm, gdbarch, language);
151   if (arg1 == NULL)
152     return except_scm;
153 
154   arg2 = vlscm_convert_value_from_scheme (func_name, SCM_ARG2, y,
155 					  &except_scm, gdbarch, language);
156   if (arg2 == NULL)
157     return except_scm;
158 
159   switch (opcode)
160     {
161     case VALSCM_ADD:
162       {
163 	struct type *ltype = value_type (arg1);
164 	struct type *rtype = value_type (arg2);
165 
166 	ltype = check_typedef (ltype);
167 	ltype = STRIP_REFERENCE (ltype);
168 	rtype = check_typedef (rtype);
169 	rtype = STRIP_REFERENCE (rtype);
170 
171 	if (TYPE_CODE (ltype) == TYPE_CODE_PTR
172 	    && is_integral_type (rtype))
173 	  res_val = value_ptradd (arg1, value_as_long (arg2));
174 	else if (TYPE_CODE (rtype) == TYPE_CODE_PTR
175 		 && is_integral_type (ltype))
176 	  res_val = value_ptradd (arg2, value_as_long (arg1));
177 	else
178 	  res_val = value_binop (arg1, arg2, BINOP_ADD);
179       }
180       break;
181     case VALSCM_SUB:
182       {
183 	struct type *ltype = value_type (arg1);
184 	struct type *rtype = value_type (arg2);
185 
186 	ltype = check_typedef (ltype);
187 	ltype = STRIP_REFERENCE (ltype);
188 	rtype = check_typedef (rtype);
189 	rtype = STRIP_REFERENCE (rtype);
190 
191 	if (TYPE_CODE (ltype) == TYPE_CODE_PTR
192 	    && TYPE_CODE (rtype) == TYPE_CODE_PTR)
193 	  {
194 	    /* A ptrdiff_t for the target would be preferable here.  */
195 	    res_val
196 	      = value_from_longest (builtin_type (gdbarch)->builtin_long,
197 				    value_ptrdiff (arg1, arg2));
198 	  }
199 	else if (TYPE_CODE (ltype) == TYPE_CODE_PTR
200 		 && is_integral_type (rtype))
201 	  res_val = value_ptradd (arg1, - value_as_long (arg2));
202 	else
203 	  res_val = value_binop (arg1, arg2, BINOP_SUB);
204       }
205       break;
206     case VALSCM_MUL:
207       res_val = value_binop (arg1, arg2, BINOP_MUL);
208       break;
209     case VALSCM_DIV:
210       res_val = value_binop (arg1, arg2, BINOP_DIV);
211       break;
212     case VALSCM_REM:
213       res_val = value_binop (arg1, arg2, BINOP_REM);
214       break;
215     case VALSCM_MOD:
216       res_val = value_binop (arg1, arg2, BINOP_MOD);
217       break;
218     case VALSCM_POW:
219       res_val = value_binop (arg1, arg2, BINOP_EXP);
220       break;
221     case VALSCM_LSH:
222       res_val = value_binop (arg1, arg2, BINOP_LSH);
223       break;
224     case VALSCM_RSH:
225       res_val = value_binop (arg1, arg2, BINOP_RSH);
226       break;
227     case VALSCM_MIN:
228       res_val = value_binop (arg1, arg2, BINOP_MIN);
229       break;
230     case VALSCM_MAX:
231       res_val = value_binop (arg1, arg2, BINOP_MAX);
232       break;
233     case VALSCM_BITAND:
234       res_val = value_binop (arg1, arg2, BINOP_BITWISE_AND);
235       break;
236     case VALSCM_BITOR:
237       res_val = value_binop (arg1, arg2, BINOP_BITWISE_IOR);
238       break;
239     case VALSCM_BITXOR:
240       res_val = value_binop (arg1, arg2, BINOP_BITWISE_XOR);
241       break;
242     default:
243       gdb_assert_not_reached ("unsupported operation");
244     }
245 
246   gdb_assert (res_val != NULL);
247   return vlscm_scm_from_value (res_val);
248 }
249 
250 /* Returns a value object which is the result of applying the operation
251    specified by OPCODE to the given arguments.
252    If there's an error a Scheme exception is thrown.  */
253 
254 static SCM
255 vlscm_binop (enum valscm_binary_opcode opcode, SCM x, SCM y,
256 	     const char *func_name)
257 {
258   return gdbscm_wrap (vlscm_binop_gdbthrow, opcode, x, y, func_name);
259 }
260 
261 /* (value-add x y) -> <gdb:value> */
262 
263 static SCM
264 gdbscm_value_add (SCM x, SCM y)
265 {
266   return vlscm_binop (VALSCM_ADD, x, y, FUNC_NAME);
267 }
268 
269 /* (value-sub x y) -> <gdb:value> */
270 
271 static SCM
272 gdbscm_value_sub (SCM x, SCM y)
273 {
274   return vlscm_binop (VALSCM_SUB, x, y, FUNC_NAME);
275 }
276 
277 /* (value-mul x y) -> <gdb:value> */
278 
279 static SCM
280 gdbscm_value_mul (SCM x, SCM y)
281 {
282   return vlscm_binop (VALSCM_MUL, x, y, FUNC_NAME);
283 }
284 
285 /* (value-div x y) -> <gdb:value> */
286 
287 static SCM
288 gdbscm_value_div (SCM x, SCM y)
289 {
290   return vlscm_binop (VALSCM_DIV, x, y, FUNC_NAME);
291 }
292 
293 /* (value-rem x y) -> <gdb:value> */
294 
295 static SCM
296 gdbscm_value_rem (SCM x, SCM y)
297 {
298   return vlscm_binop (VALSCM_REM, x, y, FUNC_NAME);
299 }
300 
301 /* (value-mod x y) -> <gdb:value> */
302 
303 static SCM
304 gdbscm_value_mod (SCM x, SCM y)
305 {
306   return vlscm_binop (VALSCM_MOD, x, y, FUNC_NAME);
307 }
308 
309 /* (value-pow x y) -> <gdb:value> */
310 
311 static SCM
312 gdbscm_value_pow (SCM x, SCM y)
313 {
314   return vlscm_binop (VALSCM_POW, x, y, FUNC_NAME);
315 }
316 
317 /* (value-neg x) -> <gdb:value> */
318 
319 static SCM
320 gdbscm_value_neg (SCM x)
321 {
322   return vlscm_unop (VALSCM_NEG, x, FUNC_NAME);
323 }
324 
325 /* (value-pos x) -> <gdb:value> */
326 
327 static SCM
328 gdbscm_value_pos (SCM x)
329 {
330   return vlscm_unop (VALSCM_NOP, x, FUNC_NAME);
331 }
332 
333 /* (value-abs x) -> <gdb:value> */
334 
335 static SCM
336 gdbscm_value_abs (SCM x)
337 {
338   return vlscm_unop (VALSCM_ABS, x, FUNC_NAME);
339 }
340 
341 /* (value-lsh x y) -> <gdb:value> */
342 
343 static SCM
344 gdbscm_value_lsh (SCM x, SCM y)
345 {
346   return vlscm_binop (VALSCM_LSH, x, y, FUNC_NAME);
347 }
348 
349 /* (value-rsh x y) -> <gdb:value> */
350 
351 static SCM
352 gdbscm_value_rsh (SCM x, SCM y)
353 {
354   return vlscm_binop (VALSCM_RSH, x, y, FUNC_NAME);
355 }
356 
357 /* (value-min x y) -> <gdb:value> */
358 
359 static SCM
360 gdbscm_value_min (SCM x, SCM y)
361 {
362   return vlscm_binop (VALSCM_MIN, x, y, FUNC_NAME);
363 }
364 
365 /* (value-max x y) -> <gdb:value> */
366 
367 static SCM
368 gdbscm_value_max (SCM x, SCM y)
369 {
370   return vlscm_binop (VALSCM_MAX, x, y, FUNC_NAME);
371 }
372 
373 /* (value-not x) -> <gdb:value> */
374 
375 static SCM
376 gdbscm_value_not (SCM x)
377 {
378   return vlscm_unop (VALSCM_NOT, x, FUNC_NAME);
379 }
380 
381 /* (value-lognot x) -> <gdb:value> */
382 
383 static SCM
384 gdbscm_value_lognot (SCM x)
385 {
386   return vlscm_unop (VALSCM_LOGNOT, x, FUNC_NAME);
387 }
388 
389 /* (value-logand x y) -> <gdb:value> */
390 
391 static SCM
392 gdbscm_value_logand (SCM x, SCM y)
393 {
394   return vlscm_binop (VALSCM_BITAND, x, y, FUNC_NAME);
395 }
396 
397 /* (value-logior x y) -> <gdb:value> */
398 
399 static SCM
400 gdbscm_value_logior (SCM x, SCM y)
401 {
402   return vlscm_binop (VALSCM_BITOR, x, y, FUNC_NAME);
403 }
404 
405 /* (value-logxor x y) -> <gdb:value> */
406 
407 static SCM
408 gdbscm_value_logxor (SCM x, SCM y)
409 {
410   return vlscm_binop (VALSCM_BITXOR, x, y, FUNC_NAME);
411 }
412 
413 /* Utility to perform all value comparisons.
414    If there's an error a Scheme exception is thrown.  */
415 
416 static SCM
417 vlscm_rich_compare (int op, SCM x, SCM y, const char *func_name)
418 {
419   return gdbscm_wrap ([=]
420     {
421       struct gdbarch *gdbarch = get_current_arch ();
422       const struct language_defn *language = current_language;
423       SCM except_scm;
424 
425       scoped_value_mark free_values;
426 
427       value *v1
428 	= vlscm_convert_value_from_scheme (func_name, SCM_ARG1, x,
429 					   &except_scm, gdbarch, language);
430       if (v1 == NULL)
431 	return except_scm;
432 
433       value *v2
434 	= vlscm_convert_value_from_scheme (func_name, SCM_ARG2, y,
435 					   &except_scm, gdbarch, language);
436       if (v2 == NULL)
437 	return except_scm;
438 
439       int result;
440       switch (op)
441 	{
442         case BINOP_LESS:
443 	  result = value_less (v1, v2);
444 	  break;
445 	case BINOP_LEQ:
446 	  result = (value_less (v1, v2)
447 		    || value_equal (v1, v2));
448 	  break;
449 	case BINOP_EQUAL:
450 	  result = value_equal (v1, v2);
451 	  break;
452 	case BINOP_NOTEQUAL:
453 	  gdb_assert_not_reached ("not-equal not implemented");
454         case BINOP_GTR:
455 	  result = value_less (v2, v1);
456 	  break;
457 	case BINOP_GEQ:
458 	  result = (value_less (v2, v1)
459 		    || value_equal (v1, v2));
460 	  break;
461 	default:
462 	  gdb_assert_not_reached ("invalid <gdb:value> comparison");
463 	}
464       return scm_from_bool (result);
465     });
466 }
467 
468 /* (value=? x y) -> boolean
469    There is no "not-equal?" function (value!= ?) on purpose.
470    We're following string=?, etc. as our Guide here.  */
471 
472 static SCM
473 gdbscm_value_eq_p (SCM x, SCM y)
474 {
475   return vlscm_rich_compare (BINOP_EQUAL, x, y, FUNC_NAME);
476 }
477 
478 /* (value<? x y) -> boolean */
479 
480 static SCM
481 gdbscm_value_lt_p (SCM x, SCM y)
482 {
483   return vlscm_rich_compare (BINOP_LESS, x, y, FUNC_NAME);
484 }
485 
486 /* (value<=? x y) -> boolean */
487 
488 static SCM
489 gdbscm_value_le_p (SCM x, SCM y)
490 {
491   return vlscm_rich_compare (BINOP_LEQ, x, y, FUNC_NAME);
492 }
493 
494 /* (value>? x y) -> boolean */
495 
496 static SCM
497 gdbscm_value_gt_p (SCM x, SCM y)
498 {
499   return vlscm_rich_compare (BINOP_GTR, x, y, FUNC_NAME);
500 }
501 
502 /* (value>=? x y) -> boolean */
503 
504 static SCM
505 gdbscm_value_ge_p (SCM x, SCM y)
506 {
507   return vlscm_rich_compare (BINOP_GEQ, x, y, FUNC_NAME);
508 }
509 
510 /* Subroutine of vlscm_convert_typed_value_from_scheme to simplify it.
511    Convert OBJ, a Scheme number, to a <gdb:value> object.
512    OBJ_ARG_POS is its position in the argument list, used in exception text.
513 
514    TYPE is the result type.  TYPE_ARG_POS is its position in
515    the argument list, used in exception text.
516    TYPE_SCM is Scheme object wrapping TYPE, used in exception text.
517 
518    If the number isn't representable, e.g. it's too big, a <gdb:exception>
519    object is stored in *EXCEPT_SCMP and NULL is returned.
520    The conversion may throw a gdb error, e.g., if TYPE is invalid.  */
521 
522 static struct value *
523 vlscm_convert_typed_number (const char *func_name, int obj_arg_pos, SCM obj,
524 			    int type_arg_pos, SCM type_scm, struct type *type,
525 			    struct gdbarch *gdbarch, SCM *except_scmp)
526 {
527   if (is_integral_type (type)
528       || TYPE_CODE (type) == TYPE_CODE_PTR)
529     {
530       if (TYPE_UNSIGNED (type))
531 	{
532 	  ULONGEST max;
533 
534 	  get_unsigned_type_max (type, &max);
535 	  if (!scm_is_unsigned_integer (obj, 0, max))
536 	    {
537 	      *except_scmp
538 		= gdbscm_make_out_of_range_error (func_name,
539 						  obj_arg_pos, obj,
540 					_("value out of range for type"));
541 	      return NULL;
542 	    }
543 	  return value_from_longest (type, gdbscm_scm_to_ulongest (obj));
544 	}
545       else
546 	{
547 	  LONGEST min, max;
548 
549 	  get_signed_type_minmax (type, &min, &max);
550 	  if (!scm_is_signed_integer (obj, min, max))
551 	    {
552 	      *except_scmp
553 		= gdbscm_make_out_of_range_error (func_name,
554 						  obj_arg_pos, obj,
555 					_("value out of range for type"));
556 	      return NULL;
557 	    }
558 	  return value_from_longest (type, gdbscm_scm_to_longest (obj));
559 	}
560     }
561   else if (TYPE_CODE (type) == TYPE_CODE_FLT)
562     {
563       struct value *value = allocate_value (type);
564       target_float_from_host_double (value_contents_raw (value),
565 				     value_type (value),
566 				     scm_to_double (obj));
567       return value;
568     }
569   else
570     {
571       *except_scmp = gdbscm_make_type_error (func_name, obj_arg_pos, obj,
572 					     NULL);
573       return NULL;
574     }
575 }
576 
577 /* Return non-zero if OBJ, an integer, fits in TYPE.  */
578 
579 static int
580 vlscm_integer_fits_p (SCM obj, struct type *type)
581 {
582   if (TYPE_UNSIGNED (type))
583     {
584       ULONGEST max;
585 
586       /* If scm_is_unsigned_integer can't work with this type, just punt.  */
587       if (TYPE_LENGTH (type) > sizeof (scm_t_uintmax))
588 	return 0;
589       get_unsigned_type_max (type, &max);
590       return scm_is_unsigned_integer (obj, 0, max);
591     }
592   else
593     {
594       LONGEST min, max;
595 
596       /* If scm_is_signed_integer can't work with this type, just punt.  */
597       if (TYPE_LENGTH (type) > sizeof (scm_t_intmax))
598 	return 0;
599       get_signed_type_minmax (type, &min, &max);
600       return scm_is_signed_integer (obj, min, max);
601     }
602 }
603 
604 /* Subroutine of vlscm_convert_typed_value_from_scheme to simplify it.
605    Convert OBJ, a Scheme number, to a <gdb:value> object.
606    OBJ_ARG_POS is its position in the argument list, used in exception text.
607 
608    If OBJ is an integer, then the smallest int that will hold the value in
609    the following progression is chosen:
610    int, unsigned int, long, unsigned long, long long, unsigned long long.
611    Otherwise, if OBJ is a real number, then it is converted to a double.
612    Otherwise an exception is thrown.
613 
614    If the number isn't representable, e.g. it's too big, a <gdb:exception>
615    object is stored in *EXCEPT_SCMP and NULL is returned.  */
616 
617 static struct value *
618 vlscm_convert_number (const char *func_name, int obj_arg_pos, SCM obj,
619 		      struct gdbarch *gdbarch, SCM *except_scmp)
620 {
621   const struct builtin_type *bt = builtin_type (gdbarch);
622 
623   /* One thing to keep in mind here is that we are interested in the
624      target's representation of OBJ, not the host's.  */
625 
626   if (scm_is_exact (obj) && scm_is_integer (obj))
627     {
628       if (vlscm_integer_fits_p (obj, bt->builtin_int))
629 	return value_from_longest (bt->builtin_int,
630 				   gdbscm_scm_to_longest (obj));
631       if (vlscm_integer_fits_p (obj, bt->builtin_unsigned_int))
632 	return value_from_longest (bt->builtin_unsigned_int,
633 				   gdbscm_scm_to_ulongest (obj));
634       if (vlscm_integer_fits_p (obj, bt->builtin_long))
635 	return value_from_longest (bt->builtin_long,
636 				   gdbscm_scm_to_longest (obj));
637       if (vlscm_integer_fits_p (obj, bt->builtin_unsigned_long))
638 	return value_from_longest (bt->builtin_unsigned_long,
639 				   gdbscm_scm_to_ulongest (obj));
640       if (vlscm_integer_fits_p (obj, bt->builtin_long_long))
641 	return value_from_longest (bt->builtin_long_long,
642 				   gdbscm_scm_to_longest (obj));
643       if (vlscm_integer_fits_p (obj, bt->builtin_unsigned_long_long))
644 	return value_from_longest (bt->builtin_unsigned_long_long,
645 				   gdbscm_scm_to_ulongest (obj));
646     }
647   else if (scm_is_real (obj))
648     {
649       struct value *value = allocate_value (bt->builtin_double);
650       target_float_from_host_double (value_contents_raw (value),
651 				     value_type (value),
652 				     scm_to_double (obj));
653       return value;
654     }
655 
656   *except_scmp = gdbscm_make_out_of_range_error (func_name, obj_arg_pos, obj,
657 			_("value not a number representable on the target"));
658   return NULL;
659 }
660 
661 /* Subroutine of vlscm_convert_typed_value_from_scheme to simplify it.
662    Convert BV, a Scheme bytevector, to a <gdb:value> object.
663 
664    TYPE, if non-NULL, is the result type.  Otherwise, a vector of type
665    uint8_t is used.
666    TYPE_SCM is Scheme object wrapping TYPE, used in exception text,
667    or #f if TYPE is NULL.
668 
669    If the bytevector isn't the same size as the type, then a <gdb:exception>
670    object is stored in *EXCEPT_SCMP, and NULL is returned.  */
671 
672 static struct value *
673 vlscm_convert_bytevector (SCM bv, struct type *type, SCM type_scm,
674 			  int arg_pos, const char *func_name,
675 			  SCM *except_scmp, struct gdbarch *gdbarch)
676 {
677   LONGEST length = SCM_BYTEVECTOR_LENGTH (bv);
678   struct value *value;
679 
680   if (type == NULL)
681     {
682       type = builtin_type (gdbarch)->builtin_uint8;
683       type = lookup_array_range_type (type, 0, length);
684       make_vector_type (type);
685     }
686   type = check_typedef (type);
687   if (TYPE_LENGTH (type) != length)
688     {
689       *except_scmp = gdbscm_make_out_of_range_error (func_name, arg_pos,
690 						     type_scm,
691 			_("size of type does not match size of bytevector"));
692       return NULL;
693     }
694 
695   value = value_from_contents (type,
696 			       (gdb_byte *) SCM_BYTEVECTOR_CONTENTS (bv));
697   return value;
698 }
699 
700 /* Convert OBJ, a Scheme value, to a <gdb:value> object.
701    OBJ_ARG_POS is its position in the argument list, used in exception text.
702 
703    TYPE, if non-NULL, is the result type which must be compatible with
704    the value being converted.
705    If TYPE is NULL then a suitable default type is chosen.
706    TYPE_SCM is Scheme object wrapping TYPE, used in exception text,
707    or SCM_UNDEFINED if TYPE is NULL.
708    TYPE_ARG_POS is its position in the argument list, used in exception text,
709    or -1 if TYPE is NULL.
710 
711    OBJ may also be a <gdb:value> object, in which case a copy is returned
712    and TYPE must be NULL.
713 
714    If the value cannot be converted, NULL is returned and a gdb:exception
715    object is stored in *EXCEPT_SCMP.
716    Otherwise the new value is returned, added to the all_values chain.  */
717 
718 struct value *
719 vlscm_convert_typed_value_from_scheme (const char *func_name,
720 				       int obj_arg_pos, SCM obj,
721 				       int type_arg_pos, SCM type_scm,
722 				       struct type *type,
723 				       SCM *except_scmp,
724 				       struct gdbarch *gdbarch,
725 				       const struct language_defn *language)
726 {
727   struct value *value = NULL;
728   SCM except_scm = SCM_BOOL_F;
729 
730   if (type == NULL)
731     {
732       gdb_assert (type_arg_pos == -1);
733       gdb_assert (SCM_UNBNDP (type_scm));
734     }
735 
736   *except_scmp = SCM_BOOL_F;
737 
738   TRY
739     {
740       if (vlscm_is_value (obj))
741 	{
742 	  if (type != NULL)
743 	    {
744 	      except_scm = gdbscm_make_misc_error (func_name, type_arg_pos,
745 						   type_scm,
746 						   _("No type allowed"));
747 	      value = NULL;
748 	    }
749 	  else
750 	    value = value_copy (vlscm_scm_to_value (obj));
751 	}
752       else if (gdbscm_is_true (scm_bytevector_p (obj)))
753 	{
754 	  value = vlscm_convert_bytevector (obj, type, type_scm,
755 					    obj_arg_pos, func_name,
756 					    &except_scm, gdbarch);
757 	}
758       else if (gdbscm_is_bool (obj))
759 	{
760 	  if (type != NULL
761 	      && !is_integral_type (type))
762 	    {
763 	      except_scm = gdbscm_make_type_error (func_name, type_arg_pos,
764 						   type_scm, NULL);
765 	    }
766 	  else
767 	    {
768 	      value = value_from_longest (type
769 					  ? type
770 					  : language_bool_type (language,
771 								gdbarch),
772 					  gdbscm_is_true (obj));
773 	    }
774 	}
775       else if (scm_is_number (obj))
776 	{
777 	  if (type != NULL)
778 	    {
779 	      value = vlscm_convert_typed_number (func_name, obj_arg_pos, obj,
780 						  type_arg_pos, type_scm, type,
781 						  gdbarch, &except_scm);
782 	    }
783 	  else
784 	    {
785 	      value = vlscm_convert_number (func_name, obj_arg_pos, obj,
786 					    gdbarch, &except_scm);
787 	    }
788 	}
789       else if (scm_is_string (obj))
790 	{
791 	  size_t len;
792 
793 	  if (type != NULL)
794 	    {
795 	      except_scm = gdbscm_make_misc_error (func_name, type_arg_pos,
796 						   type_scm,
797 						   _("No type allowed"));
798 	      value = NULL;
799 	    }
800 	  else
801 	    {
802 	      /* TODO: Provide option to specify conversion strategy.  */
803 	      gdb::unique_xmalloc_ptr<char> s
804 		= gdbscm_scm_to_string (obj, &len,
805 					target_charset (gdbarch),
806 					0 /*non-strict*/,
807 					&except_scm);
808 	      if (s != NULL)
809 		value = value_cstring (s.get (), len,
810 				       language_string_char_type (language,
811 								  gdbarch));
812 	      else
813 		value = NULL;
814 	    }
815 	}
816       else if (lsscm_is_lazy_string (obj))
817 	{
818 	  if (type != NULL)
819 	    {
820 	      except_scm = gdbscm_make_misc_error (func_name, type_arg_pos,
821 						   type_scm,
822 						   _("No type allowed"));
823 	      value = NULL;
824 	    }
825 	  else
826 	    {
827 	      value = lsscm_safe_lazy_string_to_value (obj, obj_arg_pos,
828 						       func_name,
829 						       &except_scm);
830 	    }
831 	}
832       else /* OBJ isn't anything we support.  */
833 	{
834 	  except_scm = gdbscm_make_type_error (func_name, obj_arg_pos, obj,
835 					       NULL);
836 	  value = NULL;
837 	}
838     }
839   CATCH (except, RETURN_MASK_ALL)
840     {
841       except_scm = gdbscm_scm_from_gdb_exception (except);
842     }
843   END_CATCH
844 
845   if (gdbscm_is_true (except_scm))
846     {
847       gdb_assert (value == NULL);
848       *except_scmp = except_scm;
849     }
850 
851   return value;
852 }
853 
854 /* Wrapper around vlscm_convert_typed_value_from_scheme for cases where there
855    is no supplied type.  See vlscm_convert_typed_value_from_scheme for
856    details.  */
857 
858 struct value *
859 vlscm_convert_value_from_scheme (const char *func_name,
860 				 int obj_arg_pos, SCM obj,
861 				 SCM *except_scmp, struct gdbarch *gdbarch,
862 				 const struct language_defn *language)
863 {
864   return vlscm_convert_typed_value_from_scheme (func_name, obj_arg_pos, obj,
865 						-1, SCM_UNDEFINED, NULL,
866 						except_scmp,
867 						gdbarch, language);
868 }
869 
870 /* Initialize value math support.  */
871 
872 static const scheme_function math_functions[] =
873 {
874   { "value-add", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_add),
875     "\
876 Return a + b." },
877 
878   { "value-sub", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_sub),
879     "\
880 Return a - b." },
881 
882   { "value-mul", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_mul),
883     "\
884 Return a * b." },
885 
886   { "value-div", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_div),
887     "\
888 Return a / b." },
889 
890   { "value-rem", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_rem),
891     "\
892 Return a % b." },
893 
894   { "value-mod", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_mod),
895     "\
896 Return a mod b.  See Knuth 1.2.4." },
897 
898   { "value-pow", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_pow),
899     "\
900 Return pow (x, y)." },
901 
902   { "value-not", 1, 0, 0, as_a_scm_t_subr (gdbscm_value_not),
903     "\
904 Return !a." },
905 
906   { "value-neg", 1, 0, 0, as_a_scm_t_subr (gdbscm_value_neg),
907     "\
908 Return -a." },
909 
910   { "value-pos", 1, 0, 0, as_a_scm_t_subr (gdbscm_value_pos),
911     "\
912 Return a." },
913 
914   { "value-abs", 1, 0, 0, as_a_scm_t_subr (gdbscm_value_abs),
915     "\
916 Return abs (a)." },
917 
918   { "value-lsh", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_lsh),
919     "\
920 Return a << b." },
921 
922   { "value-rsh", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_rsh),
923     "\
924 Return a >> b." },
925 
926   { "value-min", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_min),
927     "\
928 Return min (a, b)." },
929 
930   { "value-max", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_max),
931     "\
932 Return max (a, b)." },
933 
934   { "value-lognot", 1, 0, 0, as_a_scm_t_subr (gdbscm_value_lognot),
935     "\
936 Return ~a." },
937 
938   { "value-logand", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_logand),
939     "\
940 Return a & b." },
941 
942   { "value-logior", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_logior),
943     "\
944 Return a | b." },
945 
946   { "value-logxor", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_logxor),
947     "\
948 Return a ^ b." },
949 
950   { "value=?", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_eq_p),
951     "\
952 Return a == b." },
953 
954   { "value<?", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_lt_p),
955     "\
956 Return a < b." },
957 
958   { "value<=?", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_le_p),
959     "\
960 Return a <= b." },
961 
962   { "value>?", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_gt_p),
963     "\
964 Return a > b." },
965 
966   { "value>=?", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_ge_p),
967     "\
968 Return a >= b." },
969 
970   END_FUNCTIONS
971 };
972 
973 void
974 gdbscm_initialize_math (void)
975 {
976   gdbscm_define_functions (math_functions, 1);
977 }
978