xref: /dflybsd-src/contrib/gdb-7/gdb/valprint.c (revision 0eb2eccd5a86ef7dd7492d2651de55c3589f23d7)
1 /* Print values for GDB, the GNU debugger.
2 
3    Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4    1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
5    2009, 2010 Free Software Foundation, Inc.
6 
7    This file is part of GDB.
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
21 
22 #include "defs.h"
23 #include "gdb_string.h"
24 #include "symtab.h"
25 #include "gdbtypes.h"
26 #include "value.h"
27 #include "gdbcore.h"
28 #include "gdbcmd.h"
29 #include "target.h"
30 #include "language.h"
31 #include "annotate.h"
32 #include "valprint.h"
33 #include "floatformat.h"
34 #include "doublest.h"
35 #include "exceptions.h"
36 #include "dfp.h"
37 #include "python/python.h"
38 #include "ada-lang.h"
39 
40 #include <errno.h>
41 
42 /* Prototypes for local functions */
43 
44 static int partial_memory_read (CORE_ADDR memaddr, gdb_byte *myaddr,
45 				int len, int *errnoptr);
46 
47 static void show_print (char *, int);
48 
49 static void set_print (char *, int);
50 
51 static void set_radix (char *, int);
52 
53 static void show_radix (char *, int);
54 
55 static void set_input_radix (char *, int, struct cmd_list_element *);
56 
57 static void set_input_radix_1 (int, unsigned);
58 
59 static void set_output_radix (char *, int, struct cmd_list_element *);
60 
61 static void set_output_radix_1 (int, unsigned);
62 
63 void _initialize_valprint (void);
64 
65 #define PRINT_MAX_DEFAULT 200	/* Start print_max off at this value. */
66 
67 struct value_print_options user_print_options =
68 {
69   Val_pretty_default,		/* pretty */
70   0,				/* prettyprint_arrays */
71   0,				/* prettyprint_structs */
72   0,				/* vtblprint */
73   1,				/* unionprint */
74   1,				/* addressprint */
75   0,				/* objectprint */
76   PRINT_MAX_DEFAULT,		/* print_max */
77   10,				/* repeat_count_threshold */
78   0,				/* output_format */
79   0,				/* format */
80   0,				/* stop_print_at_null */
81   0,				/* inspect_it */
82   0,				/* print_array_indexes */
83   0,				/* deref_ref */
84   1,				/* static_field_print */
85   1,				/* pascal_static_field_print */
86   0,				/* raw */
87   0				/* summary */
88 };
89 
90 /* Initialize *OPTS to be a copy of the user print options.  */
91 void
92 get_user_print_options (struct value_print_options *opts)
93 {
94   *opts = user_print_options;
95 }
96 
97 /* Initialize *OPTS to be a copy of the user print options, but with
98    pretty-printing disabled.  */
99 void
100 get_raw_print_options (struct value_print_options *opts)
101 {
102   *opts = user_print_options;
103   opts->pretty = Val_no_prettyprint;
104 }
105 
106 /* Initialize *OPTS to be a copy of the user print options, but using
107    FORMAT as the formatting option.  */
108 void
109 get_formatted_print_options (struct value_print_options *opts,
110 			     char format)
111 {
112   *opts = user_print_options;
113   opts->format = format;
114 }
115 
116 static void
117 show_print_max (struct ui_file *file, int from_tty,
118 		struct cmd_list_element *c, const char *value)
119 {
120   fprintf_filtered (file, _("\
121 Limit on string chars or array elements to print is %s.\n"),
122 		    value);
123 }
124 
125 
126 /* Default input and output radixes, and output format letter.  */
127 
128 unsigned input_radix = 10;
129 static void
130 show_input_radix (struct ui_file *file, int from_tty,
131 		  struct cmd_list_element *c, const char *value)
132 {
133   fprintf_filtered (file, _("\
134 Default input radix for entering numbers is %s.\n"),
135 		    value);
136 }
137 
138 unsigned output_radix = 10;
139 static void
140 show_output_radix (struct ui_file *file, int from_tty,
141 		   struct cmd_list_element *c, const char *value)
142 {
143   fprintf_filtered (file, _("\
144 Default output radix for printing of values is %s.\n"),
145 		    value);
146 }
147 
148 /* By default we print arrays without printing the index of each element in
149    the array.  This behavior can be changed by setting PRINT_ARRAY_INDEXES.  */
150 
151 static void
152 show_print_array_indexes (struct ui_file *file, int from_tty,
153 		          struct cmd_list_element *c, const char *value)
154 {
155   fprintf_filtered (file, _("Printing of array indexes is %s.\n"), value);
156 }
157 
158 /* Print repeat counts if there are more than this many repetitions of an
159    element in an array.  Referenced by the low level language dependent
160    print routines. */
161 
162 static void
163 show_repeat_count_threshold (struct ui_file *file, int from_tty,
164 			     struct cmd_list_element *c, const char *value)
165 {
166   fprintf_filtered (file, _("Threshold for repeated print elements is %s.\n"),
167 		    value);
168 }
169 
170 /* If nonzero, stops printing of char arrays at first null. */
171 
172 static void
173 show_stop_print_at_null (struct ui_file *file, int from_tty,
174 			 struct cmd_list_element *c, const char *value)
175 {
176   fprintf_filtered (file, _("\
177 Printing of char arrays to stop at first null char is %s.\n"),
178 		    value);
179 }
180 
181 /* Controls pretty printing of structures. */
182 
183 static void
184 show_prettyprint_structs (struct ui_file *file, int from_tty,
185 			  struct cmd_list_element *c, const char *value)
186 {
187   fprintf_filtered (file, _("Prettyprinting of structures is %s.\n"), value);
188 }
189 
190 /* Controls pretty printing of arrays.  */
191 
192 static void
193 show_prettyprint_arrays (struct ui_file *file, int from_tty,
194 			 struct cmd_list_element *c, const char *value)
195 {
196   fprintf_filtered (file, _("Prettyprinting of arrays is %s.\n"), value);
197 }
198 
199 /* If nonzero, causes unions inside structures or other unions to be
200    printed. */
201 
202 static void
203 show_unionprint (struct ui_file *file, int from_tty,
204 		 struct cmd_list_element *c, const char *value)
205 {
206   fprintf_filtered (file, _("\
207 Printing of unions interior to structures is %s.\n"),
208 		    value);
209 }
210 
211 /* If nonzero, causes machine addresses to be printed in certain contexts. */
212 
213 static void
214 show_addressprint (struct ui_file *file, int from_tty,
215 		   struct cmd_list_element *c, const char *value)
216 {
217   fprintf_filtered (file, _("Printing of addresses is %s.\n"), value);
218 }
219 
220 
221 /* A helper function for val_print.  When printing in "summary" mode,
222    we want to print scalar arguments, but not aggregate arguments.
223    This function distinguishes between the two.  */
224 
225 static int
226 scalar_type_p (struct type *type)
227 {
228   CHECK_TYPEDEF (type);
229   while (TYPE_CODE (type) == TYPE_CODE_REF)
230     {
231       type = TYPE_TARGET_TYPE (type);
232       CHECK_TYPEDEF (type);
233     }
234   switch (TYPE_CODE (type))
235     {
236     case TYPE_CODE_ARRAY:
237     case TYPE_CODE_STRUCT:
238     case TYPE_CODE_UNION:
239     case TYPE_CODE_SET:
240     case TYPE_CODE_STRING:
241     case TYPE_CODE_BITSTRING:
242       return 0;
243     default:
244       return 1;
245     }
246 }
247 
248 /* Helper function to check the validity of some bits of a value.
249 
250    If TYPE represents some aggregate type (e.g., a structure), return 1.
251 
252    Otherwise, any of the bytes starting at OFFSET and extending for
253    TYPE_LENGTH(TYPE) bytes are invalid, print a message to STREAM and
254    return 0.  The checking is done using FUNCS.
255 
256    Otherwise, return 1.  */
257 
258 static int
259 valprint_check_validity (struct ui_file *stream,
260 			 struct type *type,
261 			 int offset,
262 			 const struct value *val)
263 {
264   CHECK_TYPEDEF (type);
265 
266   if (TYPE_CODE (type) != TYPE_CODE_UNION
267       && TYPE_CODE (type) != TYPE_CODE_STRUCT
268       && TYPE_CODE (type) != TYPE_CODE_ARRAY)
269     {
270       if (! value_bits_valid (val, TARGET_CHAR_BIT * offset,
271 			      TARGET_CHAR_BIT * TYPE_LENGTH (type)))
272 	{
273 	  fprintf_filtered (stream, _("<value optimized out>"));
274 	  return 0;
275 	}
276     }
277 
278   return 1;
279 }
280 
281 /* Print using the given LANGUAGE the data of type TYPE located at VALADDR
282    (within GDB), which came from the inferior at address ADDRESS, onto
283    stdio stream STREAM according to OPTIONS.
284 
285    If the data are a string pointer, returns the number of string characters
286    printed.
287 
288    FIXME:  The data at VALADDR is in target byte order.  If gdb is ever
289    enhanced to be able to debug more than the single target it was compiled
290    for (specific CPU type and thus specific target byte ordering), then
291    either the print routines are going to have to take this into account,
292    or the data is going to have to be passed into here already converted
293    to the host byte ordering, whichever is more convenient. */
294 
295 
296 int
297 val_print (struct type *type, const gdb_byte *valaddr, int embedded_offset,
298 	   CORE_ADDR address, struct ui_file *stream, int recurse,
299 	   const struct value *val,
300 	   const struct value_print_options *options,
301 	   const struct language_defn *language)
302 {
303   volatile struct gdb_exception except;
304   int ret = 0;
305   struct value_print_options local_opts = *options;
306   struct type *real_type = check_typedef (type);
307 
308   if (local_opts.pretty == Val_pretty_default)
309     local_opts.pretty = (local_opts.prettyprint_structs
310 			 ? Val_prettyprint : Val_no_prettyprint);
311 
312   QUIT;
313 
314   /* Ensure that the type is complete and not just a stub.  If the type is
315      only a stub and we can't find and substitute its complete type, then
316      print appropriate string and return.  */
317 
318   if (TYPE_STUB (real_type))
319     {
320       fprintf_filtered (stream, _("<incomplete type>"));
321       gdb_flush (stream);
322       return (0);
323     }
324 
325   if (!valprint_check_validity (stream, real_type, embedded_offset, val))
326     return 0;
327 
328   if (!options->raw)
329     {
330       ret = apply_val_pretty_printer (type, valaddr, embedded_offset,
331 				      address, stream, recurse,
332 				      val, options, language);
333       if (ret)
334 	return ret;
335     }
336 
337   /* Handle summary mode.  If the value is a scalar, print it;
338      otherwise, print an ellipsis.  */
339   if (options->summary && !scalar_type_p (type))
340     {
341       fprintf_filtered (stream, "...");
342       return 0;
343     }
344 
345   TRY_CATCH (except, RETURN_MASK_ERROR)
346     {
347       ret = language->la_val_print (type, valaddr, embedded_offset, address,
348 				    stream, recurse, val,
349 				    &local_opts);
350     }
351   if (except.reason < 0)
352     fprintf_filtered (stream, _("<error reading variable>"));
353 
354   return ret;
355 }
356 
357 /* Check whether the value VAL is printable.  Return 1 if it is;
358    return 0 and print an appropriate error message to STREAM if it
359    is not.  */
360 
361 static int
362 value_check_printable (struct value *val, struct ui_file *stream)
363 {
364   if (val == 0)
365     {
366       fprintf_filtered (stream, _("<address of value unknown>"));
367       return 0;
368     }
369 
370   if (value_entirely_optimized_out (val))
371     {
372       fprintf_filtered (stream, _("<value optimized out>"));
373       return 0;
374     }
375 
376   if (TYPE_CODE (value_type (val)) == TYPE_CODE_INTERNAL_FUNCTION)
377     {
378       fprintf_filtered (stream, _("<internal function %s>"),
379 			value_internal_function_name (val));
380       return 0;
381     }
382 
383   return 1;
384 }
385 
386 /* Print using the given LANGUAGE the value VAL onto stream STREAM according
387    to OPTIONS.
388 
389    If the data are a string pointer, returns the number of string characters
390    printed.
391 
392    This is a preferable interface to val_print, above, because it uses
393    GDB's value mechanism.  */
394 
395 int
396 common_val_print (struct value *val, struct ui_file *stream, int recurse,
397 		  const struct value_print_options *options,
398 		  const struct language_defn *language)
399 {
400   if (!value_check_printable (val, stream))
401     return 0;
402 
403   if (language->la_language == language_ada)
404     /* The value might have a dynamic type, which would cause trouble
405        below when trying to extract the value contents (since the value
406        size is determined from the type size which is unknown).  So
407        get a fixed representation of our value.  */
408     val = ada_to_fixed_value (val);
409 
410   return val_print (value_type (val), value_contents_for_printing (val),
411 		    value_embedded_offset (val), value_address (val),
412 		    stream, recurse,
413 		    val, options, language);
414 }
415 
416 /* Print on stream STREAM the value VAL according to OPTIONS.  The value
417    is printed using the current_language syntax.
418 
419    If the object printed is a string pointer, return the number of string
420    bytes printed.  */
421 
422 int
423 value_print (struct value *val, struct ui_file *stream,
424 	     const struct value_print_options *options)
425 {
426   if (!value_check_printable (val, stream))
427     return 0;
428 
429   if (!options->raw)
430     {
431       int r = apply_val_pretty_printer (value_type (val),
432 					value_contents_for_printing (val),
433 					value_embedded_offset (val),
434 					value_address (val),
435 					stream, 0,
436 					val, options, current_language);
437 
438       if (r)
439 	return r;
440     }
441 
442   return LA_VALUE_PRINT (val, stream, options);
443 }
444 
445 /* Called by various <lang>_val_print routines to print
446    TYPE_CODE_INT's.  TYPE is the type.  VALADDR is the address of the
447    value.  STREAM is where to print the value.  */
448 
449 void
450 val_print_type_code_int (struct type *type, const gdb_byte *valaddr,
451 			 struct ui_file *stream)
452 {
453   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
454 
455   if (TYPE_LENGTH (type) > sizeof (LONGEST))
456     {
457       LONGEST val;
458 
459       if (TYPE_UNSIGNED (type)
460 	  && extract_long_unsigned_integer (valaddr, TYPE_LENGTH (type),
461 					    byte_order, &val))
462 	{
463 	  print_longest (stream, 'u', 0, val);
464 	}
465       else
466 	{
467 	  /* Signed, or we couldn't turn an unsigned value into a
468 	     LONGEST.  For signed values, one could assume two's
469 	     complement (a reasonable assumption, I think) and do
470 	     better than this.  */
471 	  print_hex_chars (stream, (unsigned char *) valaddr,
472 			   TYPE_LENGTH (type), byte_order);
473 	}
474     }
475   else
476     {
477       print_longest (stream, TYPE_UNSIGNED (type) ? 'u' : 'd', 0,
478 		     unpack_long (type, valaddr));
479     }
480 }
481 
482 void
483 val_print_type_code_flags (struct type *type, const gdb_byte *valaddr,
484 			   struct ui_file *stream)
485 {
486   ULONGEST val = unpack_long (type, valaddr);
487   int bitpos, nfields = TYPE_NFIELDS (type);
488 
489   fputs_filtered ("[ ", stream);
490   for (bitpos = 0; bitpos < nfields; bitpos++)
491     {
492       if (TYPE_FIELD_BITPOS (type, bitpos) != -1
493 	  && (val & ((ULONGEST)1 << bitpos)))
494 	{
495 	  if (TYPE_FIELD_NAME (type, bitpos))
496 	    fprintf_filtered (stream, "%s ", TYPE_FIELD_NAME (type, bitpos));
497 	  else
498 	    fprintf_filtered (stream, "#%d ", bitpos);
499 	}
500     }
501   fputs_filtered ("]", stream);
502 }
503 
504 /* Print a number according to FORMAT which is one of d,u,x,o,b,h,w,g.
505    The raison d'etre of this function is to consolidate printing of
506    LONG_LONG's into this one function. The format chars b,h,w,g are
507    from print_scalar_formatted().  Numbers are printed using C
508    format.
509 
510    USE_C_FORMAT means to use C format in all cases.  Without it,
511    'o' and 'x' format do not include the standard C radix prefix
512    (leading 0 or 0x).
513 
514    Hilfinger/2004-09-09: USE_C_FORMAT was originally called USE_LOCAL
515    and was intended to request formating according to the current
516    language and would be used for most integers that GDB prints.  The
517    exceptional cases were things like protocols where the format of
518    the integer is a protocol thing, not a user-visible thing).  The
519    parameter remains to preserve the information of what things might
520    be printed with language-specific format, should we ever resurrect
521    that capability. */
522 
523 void
524 print_longest (struct ui_file *stream, int format, int use_c_format,
525 	       LONGEST val_long)
526 {
527   const char *val;
528 
529   switch (format)
530     {
531     case 'd':
532       val = int_string (val_long, 10, 1, 0, 1); break;
533     case 'u':
534       val = int_string (val_long, 10, 0, 0, 1); break;
535     case 'x':
536       val = int_string (val_long, 16, 0, 0, use_c_format); break;
537     case 'b':
538       val = int_string (val_long, 16, 0, 2, 1); break;
539     case 'h':
540       val = int_string (val_long, 16, 0, 4, 1); break;
541     case 'w':
542       val = int_string (val_long, 16, 0, 8, 1); break;
543     case 'g':
544       val = int_string (val_long, 16, 0, 16, 1); break;
545       break;
546     case 'o':
547       val = int_string (val_long, 8, 0, 0, use_c_format); break;
548     default:
549       internal_error (__FILE__, __LINE__, _("failed internal consistency check"));
550     }
551   fputs_filtered (val, stream);
552 }
553 
554 /* This used to be a macro, but I don't think it is called often enough
555    to merit such treatment.  */
556 /* Convert a LONGEST to an int.  This is used in contexts (e.g. number of
557    arguments to a function, number in a value history, register number, etc.)
558    where the value must not be larger than can fit in an int.  */
559 
560 int
561 longest_to_int (LONGEST arg)
562 {
563   /* Let the compiler do the work */
564   int rtnval = (int) arg;
565 
566   /* Check for overflows or underflows */
567   if (sizeof (LONGEST) > sizeof (int))
568     {
569       if (rtnval != arg)
570 	{
571 	  error (_("Value out of range."));
572 	}
573     }
574   return (rtnval);
575 }
576 
577 /* Print a floating point value of type TYPE (not always a
578    TYPE_CODE_FLT), pointed to in GDB by VALADDR, on STREAM.  */
579 
580 void
581 print_floating (const gdb_byte *valaddr, struct type *type,
582 		struct ui_file *stream)
583 {
584   DOUBLEST doub;
585   int inv;
586   const struct floatformat *fmt = NULL;
587   unsigned len = TYPE_LENGTH (type);
588   enum float_kind kind;
589 
590   /* If it is a floating-point, check for obvious problems.  */
591   if (TYPE_CODE (type) == TYPE_CODE_FLT)
592     fmt = floatformat_from_type (type);
593   if (fmt != NULL)
594     {
595       kind = floatformat_classify (fmt, valaddr);
596       if (kind == float_nan)
597 	{
598 	  if (floatformat_is_negative (fmt, valaddr))
599 	    fprintf_filtered (stream, "-");
600 	  fprintf_filtered (stream, "nan(");
601 	  fputs_filtered ("0x", stream);
602 	  fputs_filtered (floatformat_mantissa (fmt, valaddr), stream);
603 	  fprintf_filtered (stream, ")");
604 	  return;
605 	}
606       else if (kind == float_infinite)
607 	{
608 	  if (floatformat_is_negative (fmt, valaddr))
609 	    fputs_filtered ("-", stream);
610 	  fputs_filtered ("inf", stream);
611 	  return;
612 	}
613     }
614 
615   /* NOTE: cagney/2002-01-15: The TYPE passed into print_floating()
616      isn't necessarily a TYPE_CODE_FLT.  Consequently, unpack_double
617      needs to be used as that takes care of any necessary type
618      conversions.  Such conversions are of course direct to DOUBLEST
619      and disregard any possible target floating point limitations.
620      For instance, a u64 would be converted and displayed exactly on a
621      host with 80 bit DOUBLEST but with loss of information on a host
622      with 64 bit DOUBLEST.  */
623 
624   doub = unpack_double (type, valaddr, &inv);
625   if (inv)
626     {
627       fprintf_filtered (stream, "<invalid float value>");
628       return;
629     }
630 
631   /* FIXME: kettenis/2001-01-20: The following code makes too much
632      assumptions about the host and target floating point format.  */
633 
634   /* NOTE: cagney/2002-02-03: Since the TYPE of what was passed in may
635      not necessarily be a TYPE_CODE_FLT, the below ignores that and
636      instead uses the type's length to determine the precision of the
637      floating-point value being printed.  */
638 
639   if (len < sizeof (double))
640       fprintf_filtered (stream, "%.9g", (double) doub);
641   else if (len == sizeof (double))
642       fprintf_filtered (stream, "%.17g", (double) doub);
643   else
644 #ifdef PRINTF_HAS_LONG_DOUBLE
645     fprintf_filtered (stream, "%.35Lg", doub);
646 #else
647     /* This at least wins with values that are representable as
648        doubles.  */
649     fprintf_filtered (stream, "%.17g", (double) doub);
650 #endif
651 }
652 
653 void
654 print_decimal_floating (const gdb_byte *valaddr, struct type *type,
655 			struct ui_file *stream)
656 {
657   enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
658   char decstr[MAX_DECIMAL_STRING];
659   unsigned len = TYPE_LENGTH (type);
660 
661   decimal_to_string (valaddr, len, byte_order, decstr);
662   fputs_filtered (decstr, stream);
663   return;
664 }
665 
666 void
667 print_binary_chars (struct ui_file *stream, const gdb_byte *valaddr,
668 		    unsigned len, enum bfd_endian byte_order)
669 {
670 
671 #define BITS_IN_BYTES 8
672 
673   const gdb_byte *p;
674   unsigned int i;
675   int b;
676 
677   /* Declared "int" so it will be signed.
678    * This ensures that right shift will shift in zeros.
679    */
680   const int mask = 0x080;
681 
682   /* FIXME: We should be not printing leading zeroes in most cases.  */
683 
684   if (byte_order == BFD_ENDIAN_BIG)
685     {
686       for (p = valaddr;
687 	   p < valaddr + len;
688 	   p++)
689 	{
690 	  /* Every byte has 8 binary characters; peel off
691 	   * and print from the MSB end.
692 	   */
693 	  for (i = 0; i < (BITS_IN_BYTES * sizeof (*p)); i++)
694 	    {
695 	      if (*p & (mask >> i))
696 		b = 1;
697 	      else
698 		b = 0;
699 
700 	      fprintf_filtered (stream, "%1d", b);
701 	    }
702 	}
703     }
704   else
705     {
706       for (p = valaddr + len - 1;
707 	   p >= valaddr;
708 	   p--)
709 	{
710 	  for (i = 0; i < (BITS_IN_BYTES * sizeof (*p)); i++)
711 	    {
712 	      if (*p & (mask >> i))
713 		b = 1;
714 	      else
715 		b = 0;
716 
717 	      fprintf_filtered (stream, "%1d", b);
718 	    }
719 	}
720     }
721 }
722 
723 /* VALADDR points to an integer of LEN bytes.
724  * Print it in octal on stream or format it in buf.
725  */
726 void
727 print_octal_chars (struct ui_file *stream, const gdb_byte *valaddr,
728 		   unsigned len, enum bfd_endian byte_order)
729 {
730   const gdb_byte *p;
731   unsigned char octa1, octa2, octa3, carry;
732   int cycle;
733 
734   /* FIXME: We should be not printing leading zeroes in most cases.  */
735 
736 
737   /* Octal is 3 bits, which doesn't fit.  Yuk.  So we have to track
738    * the extra bits, which cycle every three bytes:
739    *
740    * Byte side:       0            1             2          3
741    *                         |             |            |            |
742    * bit number   123 456 78 | 9 012 345 6 | 78 901 234 | 567 890 12 |
743    *
744    * Octal side:   0   1   carry  3   4  carry ...
745    *
746    * Cycle number:    0             1            2
747    *
748    * But of course we are printing from the high side, so we have to
749    * figure out where in the cycle we are so that we end up with no
750    * left over bits at the end.
751    */
752 #define BITS_IN_OCTAL 3
753 #define HIGH_ZERO     0340
754 #define LOW_ZERO      0016
755 #define CARRY_ZERO    0003
756 #define HIGH_ONE      0200
757 #define MID_ONE       0160
758 #define LOW_ONE       0016
759 #define CARRY_ONE     0001
760 #define HIGH_TWO      0300
761 #define MID_TWO       0070
762 #define LOW_TWO       0007
763 
764   /* For 32 we start in cycle 2, with two bits and one bit carry;
765    * for 64 in cycle in cycle 1, with one bit and a two bit carry.
766    */
767   cycle = (len * BITS_IN_BYTES) % BITS_IN_OCTAL;
768   carry = 0;
769 
770   fputs_filtered ("0", stream);
771   if (byte_order == BFD_ENDIAN_BIG)
772     {
773       for (p = valaddr;
774 	   p < valaddr + len;
775 	   p++)
776 	{
777 	  switch (cycle)
778 	    {
779 	    case 0:
780 	      /* No carry in, carry out two bits.
781 	       */
782 	      octa1 = (HIGH_ZERO & *p) >> 5;
783 	      octa2 = (LOW_ZERO & *p) >> 2;
784 	      carry = (CARRY_ZERO & *p);
785 	      fprintf_filtered (stream, "%o", octa1);
786 	      fprintf_filtered (stream, "%o", octa2);
787 	      break;
788 
789 	    case 1:
790 	      /* Carry in two bits, carry out one bit.
791 	       */
792 	      octa1 = (carry << 1) | ((HIGH_ONE & *p) >> 7);
793 	      octa2 = (MID_ONE & *p) >> 4;
794 	      octa3 = (LOW_ONE & *p) >> 1;
795 	      carry = (CARRY_ONE & *p);
796 	      fprintf_filtered (stream, "%o", octa1);
797 	      fprintf_filtered (stream, "%o", octa2);
798 	      fprintf_filtered (stream, "%o", octa3);
799 	      break;
800 
801 	    case 2:
802 	      /* Carry in one bit, no carry out.
803 	       */
804 	      octa1 = (carry << 2) | ((HIGH_TWO & *p) >> 6);
805 	      octa2 = (MID_TWO & *p) >> 3;
806 	      octa3 = (LOW_TWO & *p);
807 	      carry = 0;
808 	      fprintf_filtered (stream, "%o", octa1);
809 	      fprintf_filtered (stream, "%o", octa2);
810 	      fprintf_filtered (stream, "%o", octa3);
811 	      break;
812 
813 	    default:
814 	      error (_("Internal error in octal conversion;"));
815 	    }
816 
817 	  cycle++;
818 	  cycle = cycle % BITS_IN_OCTAL;
819 	}
820     }
821   else
822     {
823       for (p = valaddr + len - 1;
824 	   p >= valaddr;
825 	   p--)
826 	{
827 	  switch (cycle)
828 	    {
829 	    case 0:
830 	      /* Carry out, no carry in */
831 	      octa1 = (HIGH_ZERO & *p) >> 5;
832 	      octa2 = (LOW_ZERO & *p) >> 2;
833 	      carry = (CARRY_ZERO & *p);
834 	      fprintf_filtered (stream, "%o", octa1);
835 	      fprintf_filtered (stream, "%o", octa2);
836 	      break;
837 
838 	    case 1:
839 	      /* Carry in, carry out */
840 	      octa1 = (carry << 1) | ((HIGH_ONE & *p) >> 7);
841 	      octa2 = (MID_ONE & *p) >> 4;
842 	      octa3 = (LOW_ONE & *p) >> 1;
843 	      carry = (CARRY_ONE & *p);
844 	      fprintf_filtered (stream, "%o", octa1);
845 	      fprintf_filtered (stream, "%o", octa2);
846 	      fprintf_filtered (stream, "%o", octa3);
847 	      break;
848 
849 	    case 2:
850 	      /* Carry in, no carry out */
851 	      octa1 = (carry << 2) | ((HIGH_TWO & *p) >> 6);
852 	      octa2 = (MID_TWO & *p) >> 3;
853 	      octa3 = (LOW_TWO & *p);
854 	      carry = 0;
855 	      fprintf_filtered (stream, "%o", octa1);
856 	      fprintf_filtered (stream, "%o", octa2);
857 	      fprintf_filtered (stream, "%o", octa3);
858 	      break;
859 
860 	    default:
861 	      error (_("Internal error in octal conversion;"));
862 	    }
863 
864 	  cycle++;
865 	  cycle = cycle % BITS_IN_OCTAL;
866 	}
867     }
868 
869 }
870 
871 /* VALADDR points to an integer of LEN bytes.
872  * Print it in decimal on stream or format it in buf.
873  */
874 void
875 print_decimal_chars (struct ui_file *stream, const gdb_byte *valaddr,
876 		     unsigned len, enum bfd_endian byte_order)
877 {
878 #define TEN             10
879 #define CARRY_OUT(  x ) ((x) / TEN)	/* extend char to int */
880 #define CARRY_LEFT( x ) ((x) % TEN)
881 #define SHIFT( x )      ((x) << 4)
882 #define LOW_NIBBLE(  x ) ( (x) & 0x00F)
883 #define HIGH_NIBBLE( x ) (((x) & 0x0F0) >> 4)
884 
885   const gdb_byte *p;
886   unsigned char *digits;
887   int carry;
888   int decimal_len;
889   int i, j, decimal_digits;
890   int dummy;
891   int flip;
892 
893   /* Base-ten number is less than twice as many digits
894    * as the base 16 number, which is 2 digits per byte.
895    */
896   decimal_len = len * 2 * 2;
897   digits = xmalloc (decimal_len);
898 
899   for (i = 0; i < decimal_len; i++)
900     {
901       digits[i] = 0;
902     }
903 
904   /* Ok, we have an unknown number of bytes of data to be printed in
905    * decimal.
906    *
907    * Given a hex number (in nibbles) as XYZ, we start by taking X and
908    * decemalizing it as "x1 x2" in two decimal nibbles.  Then we multiply
909    * the nibbles by 16, add Y and re-decimalize.  Repeat with Z.
910    *
911    * The trick is that "digits" holds a base-10 number, but sometimes
912    * the individual digits are > 10.
913    *
914    * Outer loop is per nibble (hex digit) of input, from MSD end to
915    * LSD end.
916    */
917   decimal_digits = 0;		/* Number of decimal digits so far */
918   p = (byte_order == BFD_ENDIAN_BIG) ? valaddr : valaddr + len - 1;
919   flip = 0;
920   while ((byte_order == BFD_ENDIAN_BIG) ? (p < valaddr + len) : (p >= valaddr))
921     {
922       /*
923        * Multiply current base-ten number by 16 in place.
924        * Each digit was between 0 and 9, now is between
925        * 0 and 144.
926        */
927       for (j = 0; j < decimal_digits; j++)
928 	{
929 	  digits[j] = SHIFT (digits[j]);
930 	}
931 
932       /* Take the next nibble off the input and add it to what
933        * we've got in the LSB position.  Bottom 'digit' is now
934        * between 0 and 159.
935        *
936        * "flip" is used to run this loop twice for each byte.
937        */
938       if (flip == 0)
939 	{
940 	  /* Take top nibble.
941 	   */
942 	  digits[0] += HIGH_NIBBLE (*p);
943 	  flip = 1;
944 	}
945       else
946 	{
947 	  /* Take low nibble and bump our pointer "p".
948 	   */
949 	  digits[0] += LOW_NIBBLE (*p);
950           if (byte_order == BFD_ENDIAN_BIG)
951 	    p++;
952 	  else
953 	    p--;
954 	  flip = 0;
955 	}
956 
957       /* Re-decimalize.  We have to do this often enough
958        * that we don't overflow, but once per nibble is
959        * overkill.  Easier this way, though.  Note that the
960        * carry is often larger than 10 (e.g. max initial
961        * carry out of lowest nibble is 15, could bubble all
962        * the way up greater than 10).  So we have to do
963        * the carrying beyond the last current digit.
964        */
965       carry = 0;
966       for (j = 0; j < decimal_len - 1; j++)
967 	{
968 	  digits[j] += carry;
969 
970 	  /* "/" won't handle an unsigned char with
971 	   * a value that if signed would be negative.
972 	   * So extend to longword int via "dummy".
973 	   */
974 	  dummy = digits[j];
975 	  carry = CARRY_OUT (dummy);
976 	  digits[j] = CARRY_LEFT (dummy);
977 
978 	  if (j >= decimal_digits && carry == 0)
979 	    {
980 	      /*
981 	       * All higher digits are 0 and we
982 	       * no longer have a carry.
983 	       *
984 	       * Note: "j" is 0-based, "decimal_digits" is
985 	       *       1-based.
986 	       */
987 	      decimal_digits = j + 1;
988 	      break;
989 	    }
990 	}
991     }
992 
993   /* Ok, now "digits" is the decimal representation, with
994    * the "decimal_digits" actual digits.  Print!
995    */
996   for (i = decimal_digits - 1; i >= 0; i--)
997     {
998       fprintf_filtered (stream, "%1d", digits[i]);
999     }
1000   xfree (digits);
1001 }
1002 
1003 /* VALADDR points to an integer of LEN bytes.  Print it in hex on stream.  */
1004 
1005 void
1006 print_hex_chars (struct ui_file *stream, const gdb_byte *valaddr,
1007 		 unsigned len, enum bfd_endian byte_order)
1008 {
1009   const gdb_byte *p;
1010 
1011   /* FIXME: We should be not printing leading zeroes in most cases.  */
1012 
1013   fputs_filtered ("0x", stream);
1014   if (byte_order == BFD_ENDIAN_BIG)
1015     {
1016       for (p = valaddr;
1017 	   p < valaddr + len;
1018 	   p++)
1019 	{
1020 	  fprintf_filtered (stream, "%02x", *p);
1021 	}
1022     }
1023   else
1024     {
1025       for (p = valaddr + len - 1;
1026 	   p >= valaddr;
1027 	   p--)
1028 	{
1029 	  fprintf_filtered (stream, "%02x", *p);
1030 	}
1031     }
1032 }
1033 
1034 /* VALADDR points to a char integer of LEN bytes.  Print it out in appropriate language form on stream.
1035    Omit any leading zero chars.  */
1036 
1037 void
1038 print_char_chars (struct ui_file *stream, struct type *type,
1039 		  const gdb_byte *valaddr,
1040 		  unsigned len, enum bfd_endian byte_order)
1041 {
1042   const gdb_byte *p;
1043 
1044   if (byte_order == BFD_ENDIAN_BIG)
1045     {
1046       p = valaddr;
1047       while (p < valaddr + len - 1 && *p == 0)
1048 	++p;
1049 
1050       while (p < valaddr + len)
1051 	{
1052 	  LA_EMIT_CHAR (*p, type, stream, '\'');
1053 	  ++p;
1054 	}
1055     }
1056   else
1057     {
1058       p = valaddr + len - 1;
1059       while (p > valaddr && *p == 0)
1060 	--p;
1061 
1062       while (p >= valaddr)
1063 	{
1064 	  LA_EMIT_CHAR (*p, type, stream, '\'');
1065 	  --p;
1066 	}
1067     }
1068 }
1069 
1070 /* Assuming TYPE is a simple, non-empty array type, compute its upper
1071    and lower bound.  Save the low bound into LOW_BOUND if not NULL.
1072    Save the high bound into HIGH_BOUND if not NULL.
1073 
1074    Return 1 if the operation was successful. Return zero otherwise,
1075    in which case the values of LOW_BOUND and HIGH_BOUNDS are unmodified.
1076 
1077    We now simply use get_discrete_bounds call to get the values
1078    of the low and high bounds.
1079    get_discrete_bounds can return three values:
1080    1, meaning that index is a range,
1081    0, meaning that index is a discrete type,
1082    or -1 for failure.  */
1083 
1084 int
1085 get_array_bounds (struct type *type, LONGEST *low_bound, LONGEST *high_bound)
1086 {
1087   struct type *index = TYPE_INDEX_TYPE (type);
1088   LONGEST low = 0;
1089   LONGEST high = 0;
1090   int res;
1091 
1092   if (index == NULL)
1093     return 0;
1094 
1095   res = get_discrete_bounds (index, &low, &high);
1096   if (res == -1)
1097     return 0;
1098 
1099   if (low_bound)
1100     *low_bound = low;
1101 
1102   if (high_bound)
1103     *high_bound = high;
1104 
1105   return 1;
1106 }
1107 
1108 /* Print on STREAM using the given OPTIONS the index for the element
1109    at INDEX of an array whose index type is INDEX_TYPE.  */
1110 
1111 void
1112 maybe_print_array_index (struct type *index_type, LONGEST index,
1113                          struct ui_file *stream,
1114 			 const struct value_print_options *options)
1115 {
1116   struct value *index_value;
1117 
1118   if (!options->print_array_indexes)
1119     return;
1120 
1121   index_value = value_from_longest (index_type, index);
1122 
1123   LA_PRINT_ARRAY_INDEX (index_value, stream, options);
1124 }
1125 
1126 /*  Called by various <lang>_val_print routines to print elements of an
1127    array in the form "<elem1>, <elem2>, <elem3>, ...".
1128 
1129    (FIXME?)  Assumes array element separator is a comma, which is correct
1130    for all languages currently handled.
1131    (FIXME?)  Some languages have a notation for repeated array elements,
1132    perhaps we should try to use that notation when appropriate.
1133  */
1134 
1135 void
1136 val_print_array_elements (struct type *type, const gdb_byte *valaddr,
1137 			  CORE_ADDR address, struct ui_file *stream,
1138 			  int recurse,
1139 			  const struct value *val,
1140 			  const struct value_print_options *options,
1141 			  unsigned int i)
1142 {
1143   unsigned int things_printed = 0;
1144   unsigned len;
1145   struct type *elttype, *index_type;
1146   unsigned eltlen;
1147   /* Position of the array element we are examining to see
1148      whether it is repeated.  */
1149   unsigned int rep1;
1150   /* Number of repetitions we have detected so far.  */
1151   unsigned int reps;
1152   LONGEST low_bound_index = 0;
1153 
1154   elttype = TYPE_TARGET_TYPE (type);
1155   eltlen = TYPE_LENGTH (check_typedef (elttype));
1156   index_type = TYPE_INDEX_TYPE (type);
1157 
1158   /* Compute the number of elements in the array.  On most arrays,
1159      the size of its elements is not zero, and so the number of elements
1160      is simply the size of the array divided by the size of the elements.
1161      But for arrays of elements whose size is zero, we need to look at
1162      the bounds.  */
1163   if (eltlen != 0)
1164     len = TYPE_LENGTH (type) / eltlen;
1165   else
1166     {
1167       LONGEST low, hi;
1168 
1169       if (get_array_bounds (type, &low, &hi))
1170         len = hi - low + 1;
1171       else
1172         {
1173           warning (_("unable to get bounds of array, assuming null array"));
1174           len = 0;
1175         }
1176     }
1177 
1178   /* Get the array low bound.  This only makes sense if the array
1179      has one or more element in it.  */
1180   if (len > 0 && !get_array_bounds (type, &low_bound_index, NULL))
1181     {
1182       warning (_("unable to get low bound of array, using zero as default"));
1183       low_bound_index = 0;
1184     }
1185 
1186   annotate_array_section_begin (i, elttype);
1187 
1188   for (; i < len && things_printed < options->print_max; i++)
1189     {
1190       if (i != 0)
1191 	{
1192 	  if (options->prettyprint_arrays)
1193 	    {
1194 	      fprintf_filtered (stream, ",\n");
1195 	      print_spaces_filtered (2 + 2 * recurse, stream);
1196 	    }
1197 	  else
1198 	    {
1199 	      fprintf_filtered (stream, ", ");
1200 	    }
1201 	}
1202       wrap_here (n_spaces (2 + 2 * recurse));
1203       maybe_print_array_index (index_type, i + low_bound_index,
1204                                stream, options);
1205 
1206       rep1 = i + 1;
1207       reps = 1;
1208       while ((rep1 < len) &&
1209 	     !memcmp (valaddr + i * eltlen, valaddr + rep1 * eltlen, eltlen))
1210 	{
1211 	  ++reps;
1212 	  ++rep1;
1213 	}
1214 
1215       if (reps > options->repeat_count_threshold)
1216 	{
1217 	  val_print (elttype, valaddr + i * eltlen, 0, address + i * eltlen,
1218 		     stream, recurse + 1, val, options, current_language);
1219 	  annotate_elt_rep (reps);
1220 	  fprintf_filtered (stream, " <repeats %u times>", reps);
1221 	  annotate_elt_rep_end ();
1222 
1223 	  i = rep1 - 1;
1224 	  things_printed += options->repeat_count_threshold;
1225 	}
1226       else
1227 	{
1228 	  val_print (elttype, valaddr + i * eltlen, 0, address + i * eltlen,
1229 		     stream, recurse + 1, val, options, current_language);
1230 	  annotate_elt ();
1231 	  things_printed++;
1232 	}
1233     }
1234   annotate_array_section_end ();
1235   if (i < len)
1236     {
1237       fprintf_filtered (stream, "...");
1238     }
1239 }
1240 
1241 /* Read LEN bytes of target memory at address MEMADDR, placing the
1242    results in GDB's memory at MYADDR.  Returns a count of the bytes
1243    actually read, and optionally an errno value in the location
1244    pointed to by ERRNOPTR if ERRNOPTR is non-null. */
1245 
1246 /* FIXME: cagney/1999-10-14: Only used by val_print_string.  Can this
1247    function be eliminated.  */
1248 
1249 static int
1250 partial_memory_read (CORE_ADDR memaddr, gdb_byte *myaddr, int len, int *errnoptr)
1251 {
1252   int nread;			/* Number of bytes actually read. */
1253   int errcode;			/* Error from last read. */
1254 
1255   /* First try a complete read. */
1256   errcode = target_read_memory (memaddr, myaddr, len);
1257   if (errcode == 0)
1258     {
1259       /* Got it all. */
1260       nread = len;
1261     }
1262   else
1263     {
1264       /* Loop, reading one byte at a time until we get as much as we can. */
1265       for (errcode = 0, nread = 0; len > 0 && errcode == 0; nread++, len--)
1266 	{
1267 	  errcode = target_read_memory (memaddr++, myaddr++, 1);
1268 	}
1269       /* If an error, the last read was unsuccessful, so adjust count. */
1270       if (errcode != 0)
1271 	{
1272 	  nread--;
1273 	}
1274     }
1275   if (errnoptr != NULL)
1276     {
1277       *errnoptr = errcode;
1278     }
1279   return (nread);
1280 }
1281 
1282 /* Read a string from the inferior, at ADDR, with LEN characters of WIDTH bytes
1283    each.  Fetch at most FETCHLIMIT characters.  BUFFER will be set to a newly
1284    allocated buffer containing the string, which the caller is responsible to
1285    free, and BYTES_READ will be set to the number of bytes read.  Returns 0 on
1286    success, or errno on failure.
1287 
1288    If LEN > 0, reads exactly LEN characters (including eventual NULs in
1289    the middle or end of the string).  If LEN is -1, stops at the first
1290    null character (not necessarily the first null byte) up to a maximum
1291    of FETCHLIMIT characters.  Set FETCHLIMIT to UINT_MAX to read as many
1292    characters as possible from the string.
1293 
1294    Unless an exception is thrown, BUFFER will always be allocated, even on
1295    failure.  In this case, some characters might have been read before the
1296    failure happened.  Check BYTES_READ to recognize this situation.
1297 
1298    Note: There was a FIXME asking to make this code use target_read_string,
1299    but this function is more general (can read past null characters, up to
1300    given LEN). Besides, it is used much more often than target_read_string
1301    so it is more tested.  Perhaps callers of target_read_string should use
1302    this function instead?  */
1303 
1304 int
1305 read_string (CORE_ADDR addr, int len, int width, unsigned int fetchlimit,
1306 	     enum bfd_endian byte_order, gdb_byte **buffer, int *bytes_read)
1307 {
1308   int found_nul;		/* Non-zero if we found the nul char.  */
1309   int errcode;			/* Errno returned from bad reads.  */
1310   unsigned int nfetch;		/* Chars to fetch / chars fetched.  */
1311   unsigned int chunksize;	/* Size of each fetch, in chars.  */
1312   gdb_byte *bufptr;		/* Pointer to next available byte in buffer.  */
1313   gdb_byte *limit;		/* First location past end of fetch buffer.  */
1314   struct cleanup *old_chain = NULL;	/* Top of the old cleanup chain.  */
1315 
1316   /* Decide how large of chunks to try to read in one operation.  This
1317      is also pretty simple.  If LEN >= zero, then we want fetchlimit chars,
1318      so we might as well read them all in one operation.  If LEN is -1, we
1319      are looking for a NUL terminator to end the fetching, so we might as
1320      well read in blocks that are large enough to be efficient, but not so
1321      large as to be slow if fetchlimit happens to be large.  So we choose the
1322      minimum of 8 and fetchlimit.  We used to use 200 instead of 8 but
1323      200 is way too big for remote debugging over a serial line.  */
1324 
1325   chunksize = (len == -1 ? min (8, fetchlimit) : fetchlimit);
1326 
1327   /* Loop until we either have all the characters, or we encounter
1328      some error, such as bumping into the end of the address space.  */
1329 
1330   found_nul = 0;
1331   *buffer = NULL;
1332 
1333   old_chain = make_cleanup (free_current_contents, buffer);
1334 
1335   if (len > 0)
1336     {
1337       *buffer = (gdb_byte *) xmalloc (len * width);
1338       bufptr = *buffer;
1339 
1340       nfetch = partial_memory_read (addr, bufptr, len * width, &errcode)
1341 	/ width;
1342       addr += nfetch * width;
1343       bufptr += nfetch * width;
1344     }
1345   else if (len == -1)
1346     {
1347       unsigned long bufsize = 0;
1348 
1349       do
1350 	{
1351 	  QUIT;
1352 	  nfetch = min (chunksize, fetchlimit - bufsize);
1353 
1354 	  if (*buffer == NULL)
1355 	    *buffer = (gdb_byte *) xmalloc (nfetch * width);
1356 	  else
1357 	    *buffer = (gdb_byte *) xrealloc (*buffer,
1358 					     (nfetch + bufsize) * width);
1359 
1360 	  bufptr = *buffer + bufsize * width;
1361 	  bufsize += nfetch;
1362 
1363 	  /* Read as much as we can.  */
1364 	  nfetch = partial_memory_read (addr, bufptr, nfetch * width, &errcode)
1365 		    / width;
1366 
1367 	  /* Scan this chunk for the null character that terminates the string
1368 	     to print.  If found, we don't need to fetch any more.  Note
1369 	     that bufptr is explicitly left pointing at the next character
1370 	     after the null character, or at the next character after the end
1371 	     of the buffer.  */
1372 
1373 	  limit = bufptr + nfetch * width;
1374 	  while (bufptr < limit)
1375 	    {
1376 	      unsigned long c;
1377 
1378 	      c = extract_unsigned_integer (bufptr, width, byte_order);
1379 	      addr += width;
1380 	      bufptr += width;
1381 	      if (c == 0)
1382 		{
1383 		  /* We don't care about any error which happened after
1384 		     the NUL terminator.  */
1385 		  errcode = 0;
1386 		  found_nul = 1;
1387 		  break;
1388 		}
1389 	    }
1390 	}
1391       while (errcode == 0	/* no error */
1392 	     && bufptr - *buffer < fetchlimit * width	/* no overrun */
1393 	     && !found_nul);	/* haven't found NUL yet */
1394     }
1395   else
1396     {				/* Length of string is really 0!  */
1397       /* We always allocate *buffer.  */
1398       *buffer = bufptr = xmalloc (1);
1399       errcode = 0;
1400     }
1401 
1402   /* bufptr and addr now point immediately beyond the last byte which we
1403      consider part of the string (including a '\0' which ends the string).  */
1404   *bytes_read = bufptr - *buffer;
1405 
1406   QUIT;
1407 
1408   discard_cleanups (old_chain);
1409 
1410   return errcode;
1411 }
1412 
1413 /* Print a string from the inferior, starting at ADDR and printing up to LEN
1414    characters, of WIDTH bytes a piece, to STREAM.  If LEN is -1, printing
1415    stops at the first null byte, otherwise printing proceeds (including null
1416    bytes) until either print_max or LEN characters have been printed,
1417    whichever is smaller.  */
1418 
1419 int
1420 val_print_string (struct type *elttype, CORE_ADDR addr, int len,
1421 		  struct ui_file *stream,
1422 		  const struct value_print_options *options)
1423 {
1424   int force_ellipsis = 0;	/* Force ellipsis to be printed if nonzero.  */
1425   int errcode;			/* Errno returned from bad reads.  */
1426   int found_nul;		/* Non-zero if we found the nul char */
1427   unsigned int fetchlimit;	/* Maximum number of chars to print.  */
1428   int bytes_read;
1429   gdb_byte *buffer = NULL;	/* Dynamically growable fetch buffer.  */
1430   struct cleanup *old_chain = NULL;	/* Top of the old cleanup chain.  */
1431   struct gdbarch *gdbarch = get_type_arch (elttype);
1432   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
1433   int width = TYPE_LENGTH (elttype);
1434 
1435   /* First we need to figure out the limit on the number of characters we are
1436      going to attempt to fetch and print.  This is actually pretty simple.  If
1437      LEN >= zero, then the limit is the minimum of LEN and print_max.  If
1438      LEN is -1, then the limit is print_max.  This is true regardless of
1439      whether print_max is zero, UINT_MAX (unlimited), or something in between,
1440      because finding the null byte (or available memory) is what actually
1441      limits the fetch.  */
1442 
1443   fetchlimit = (len == -1 ? options->print_max : min (len, options->print_max));
1444 
1445   errcode = read_string (addr, len, width, fetchlimit, byte_order,
1446 			 &buffer, &bytes_read);
1447   old_chain = make_cleanup (xfree, buffer);
1448 
1449   addr += bytes_read;
1450 
1451   /* We now have either successfully filled the buffer to fetchlimit, or
1452      terminated early due to an error or finding a null char when LEN is -1.  */
1453 
1454   /* Determine found_nul by looking at the last character read.  */
1455   found_nul = extract_unsigned_integer (buffer + bytes_read - width, width,
1456 					byte_order) == 0;
1457   if (len == -1 && !found_nul)
1458     {
1459       gdb_byte *peekbuf;
1460 
1461       /* We didn't find a NUL terminator we were looking for.  Attempt
1462          to peek at the next character.  If not successful, or it is not
1463          a null byte, then force ellipsis to be printed.  */
1464 
1465       peekbuf = (gdb_byte *) alloca (width);
1466 
1467       if (target_read_memory (addr, peekbuf, width) == 0
1468 	  && extract_unsigned_integer (peekbuf, width, byte_order) != 0)
1469 	force_ellipsis = 1;
1470     }
1471   else if ((len >= 0 && errcode != 0) || (len > bytes_read / width))
1472     {
1473       /* Getting an error when we have a requested length, or fetching less
1474          than the number of characters actually requested, always make us
1475          print ellipsis.  */
1476       force_ellipsis = 1;
1477     }
1478 
1479   /* If we get an error before fetching anything, don't print a string.
1480      But if we fetch something and then get an error, print the string
1481      and then the error message.  */
1482   if (errcode == 0 || bytes_read > 0)
1483     {
1484       if (options->addressprint)
1485 	{
1486 	  fputs_filtered (" ", stream);
1487 	}
1488       LA_PRINT_STRING (stream, elttype, buffer, bytes_read / width,
1489 		       NULL, force_ellipsis, options);
1490     }
1491 
1492   if (errcode != 0)
1493     {
1494       if (errcode == EIO)
1495 	{
1496 	  fprintf_filtered (stream, " <Address ");
1497 	  fputs_filtered (paddress (gdbarch, addr), stream);
1498 	  fprintf_filtered (stream, " out of bounds>");
1499 	}
1500       else
1501 	{
1502 	  fprintf_filtered (stream, " <Error reading address ");
1503 	  fputs_filtered (paddress (gdbarch, addr), stream);
1504 	  fprintf_filtered (stream, ": %s>", safe_strerror (errcode));
1505 	}
1506     }
1507 
1508   gdb_flush (stream);
1509   do_cleanups (old_chain);
1510 
1511   return (bytes_read / width);
1512 }
1513 
1514 
1515 /* The 'set input-radix' command writes to this auxiliary variable.
1516    If the requested radix is valid, INPUT_RADIX is updated; otherwise,
1517    it is left unchanged.  */
1518 
1519 static unsigned input_radix_1 = 10;
1520 
1521 /* Validate an input or output radix setting, and make sure the user
1522    knows what they really did here.  Radix setting is confusing, e.g.
1523    setting the input radix to "10" never changes it!  */
1524 
1525 static void
1526 set_input_radix (char *args, int from_tty, struct cmd_list_element *c)
1527 {
1528   set_input_radix_1 (from_tty, input_radix_1);
1529 }
1530 
1531 static void
1532 set_input_radix_1 (int from_tty, unsigned radix)
1533 {
1534   /* We don't currently disallow any input radix except 0 or 1, which don't
1535      make any mathematical sense.  In theory, we can deal with any input
1536      radix greater than 1, even if we don't have unique digits for every
1537      value from 0 to radix-1, but in practice we lose on large radix values.
1538      We should either fix the lossage or restrict the radix range more.
1539      (FIXME). */
1540 
1541   if (radix < 2)
1542     {
1543       input_radix_1 = input_radix;
1544       error (_("Nonsense input radix ``decimal %u''; input radix unchanged."),
1545 	     radix);
1546     }
1547   input_radix_1 = input_radix = radix;
1548   if (from_tty)
1549     {
1550       printf_filtered (_("Input radix now set to decimal %u, hex %x, octal %o.\n"),
1551 		       radix, radix, radix);
1552     }
1553 }
1554 
1555 /* The 'set output-radix' command writes to this auxiliary variable.
1556    If the requested radix is valid, OUTPUT_RADIX is updated,
1557    otherwise, it is left unchanged.  */
1558 
1559 static unsigned output_radix_1 = 10;
1560 
1561 static void
1562 set_output_radix (char *args, int from_tty, struct cmd_list_element *c)
1563 {
1564   set_output_radix_1 (from_tty, output_radix_1);
1565 }
1566 
1567 static void
1568 set_output_radix_1 (int from_tty, unsigned radix)
1569 {
1570   /* Validate the radix and disallow ones that we aren't prepared to
1571      handle correctly, leaving the radix unchanged. */
1572   switch (radix)
1573     {
1574     case 16:
1575       user_print_options.output_format = 'x';	/* hex */
1576       break;
1577     case 10:
1578       user_print_options.output_format = 0;	/* decimal */
1579       break;
1580     case 8:
1581       user_print_options.output_format = 'o';	/* octal */
1582       break;
1583     default:
1584       output_radix_1 = output_radix;
1585       error (_("Unsupported output radix ``decimal %u''; output radix unchanged."),
1586 	     radix);
1587     }
1588   output_radix_1 = output_radix = radix;
1589   if (from_tty)
1590     {
1591       printf_filtered (_("Output radix now set to decimal %u, hex %x, octal %o.\n"),
1592 		       radix, radix, radix);
1593     }
1594 }
1595 
1596 /* Set both the input and output radix at once.  Try to set the output radix
1597    first, since it has the most restrictive range.  An radix that is valid as
1598    an output radix is also valid as an input radix.
1599 
1600    It may be useful to have an unusual input radix.  If the user wishes to
1601    set an input radix that is not valid as an output radix, he needs to use
1602    the 'set input-radix' command. */
1603 
1604 static void
1605 set_radix (char *arg, int from_tty)
1606 {
1607   unsigned radix;
1608 
1609   radix = (arg == NULL) ? 10 : parse_and_eval_long (arg);
1610   set_output_radix_1 (0, radix);
1611   set_input_radix_1 (0, radix);
1612   if (from_tty)
1613     {
1614       printf_filtered (_("Input and output radices now set to decimal %u, hex %x, octal %o.\n"),
1615 		       radix, radix, radix);
1616     }
1617 }
1618 
1619 /* Show both the input and output radices. */
1620 
1621 static void
1622 show_radix (char *arg, int from_tty)
1623 {
1624   if (from_tty)
1625     {
1626       if (input_radix == output_radix)
1627 	{
1628 	  printf_filtered (_("Input and output radices set to decimal %u, hex %x, octal %o.\n"),
1629 			   input_radix, input_radix, input_radix);
1630 	}
1631       else
1632 	{
1633 	  printf_filtered (_("Input radix set to decimal %u, hex %x, octal %o.\n"),
1634 			   input_radix, input_radix, input_radix);
1635 	  printf_filtered (_("Output radix set to decimal %u, hex %x, octal %o.\n"),
1636 			   output_radix, output_radix, output_radix);
1637 	}
1638     }
1639 }
1640 
1641 
1642 static void
1643 set_print (char *arg, int from_tty)
1644 {
1645   printf_unfiltered (
1646      "\"set print\" must be followed by the name of a print subcommand.\n");
1647   help_list (setprintlist, "set print ", -1, gdb_stdout);
1648 }
1649 
1650 static void
1651 show_print (char *args, int from_tty)
1652 {
1653   cmd_show_list (showprintlist, from_tty, "");
1654 }
1655 
1656 void
1657 _initialize_valprint (void)
1658 {
1659   add_prefix_cmd ("print", no_class, set_print,
1660 		  _("Generic command for setting how things print."),
1661 		  &setprintlist, "set print ", 0, &setlist);
1662   add_alias_cmd ("p", "print", no_class, 1, &setlist);
1663   /* prefer set print to set prompt */
1664   add_alias_cmd ("pr", "print", no_class, 1, &setlist);
1665 
1666   add_prefix_cmd ("print", no_class, show_print,
1667 		  _("Generic command for showing print settings."),
1668 		  &showprintlist, "show print ", 0, &showlist);
1669   add_alias_cmd ("p", "print", no_class, 1, &showlist);
1670   add_alias_cmd ("pr", "print", no_class, 1, &showlist);
1671 
1672   add_setshow_uinteger_cmd ("elements", no_class,
1673 			    &user_print_options.print_max, _("\
1674 Set limit on string chars or array elements to print."), _("\
1675 Show limit on string chars or array elements to print."), _("\
1676 \"set print elements 0\" causes there to be no limit."),
1677 			    NULL,
1678 			    show_print_max,
1679 			    &setprintlist, &showprintlist);
1680 
1681   add_setshow_boolean_cmd ("null-stop", no_class,
1682 			   &user_print_options.stop_print_at_null, _("\
1683 Set printing of char arrays to stop at first null char."), _("\
1684 Show printing of char arrays to stop at first null char."), NULL,
1685 			   NULL,
1686 			   show_stop_print_at_null,
1687 			   &setprintlist, &showprintlist);
1688 
1689   add_setshow_uinteger_cmd ("repeats", no_class,
1690 			    &user_print_options.repeat_count_threshold, _("\
1691 Set threshold for repeated print elements."), _("\
1692 Show threshold for repeated print elements."), _("\
1693 \"set print repeats 0\" causes all elements to be individually printed."),
1694 			    NULL,
1695 			    show_repeat_count_threshold,
1696 			    &setprintlist, &showprintlist);
1697 
1698   add_setshow_boolean_cmd ("pretty", class_support,
1699 			   &user_print_options.prettyprint_structs, _("\
1700 Set prettyprinting of structures."), _("\
1701 Show prettyprinting of structures."), NULL,
1702 			   NULL,
1703 			   show_prettyprint_structs,
1704 			   &setprintlist, &showprintlist);
1705 
1706   add_setshow_boolean_cmd ("union", class_support,
1707 			   &user_print_options.unionprint, _("\
1708 Set printing of unions interior to structures."), _("\
1709 Show printing of unions interior to structures."), NULL,
1710 			   NULL,
1711 			   show_unionprint,
1712 			   &setprintlist, &showprintlist);
1713 
1714   add_setshow_boolean_cmd ("array", class_support,
1715 			   &user_print_options.prettyprint_arrays, _("\
1716 Set prettyprinting of arrays."), _("\
1717 Show prettyprinting of arrays."), NULL,
1718 			   NULL,
1719 			   show_prettyprint_arrays,
1720 			   &setprintlist, &showprintlist);
1721 
1722   add_setshow_boolean_cmd ("address", class_support,
1723 			   &user_print_options.addressprint, _("\
1724 Set printing of addresses."), _("\
1725 Show printing of addresses."), NULL,
1726 			   NULL,
1727 			   show_addressprint,
1728 			   &setprintlist, &showprintlist);
1729 
1730   add_setshow_zuinteger_cmd ("input-radix", class_support, &input_radix_1,
1731 			     _("\
1732 Set default input radix for entering numbers."), _("\
1733 Show default input radix for entering numbers."), NULL,
1734 			     set_input_radix,
1735 			     show_input_radix,
1736 			     &setlist, &showlist);
1737 
1738   add_setshow_zuinteger_cmd ("output-radix", class_support, &output_radix_1,
1739 			     _("\
1740 Set default output radix for printing of values."), _("\
1741 Show default output radix for printing of values."), NULL,
1742 			     set_output_radix,
1743 			     show_output_radix,
1744 			     &setlist, &showlist);
1745 
1746   /* The "set radix" and "show radix" commands are special in that
1747      they are like normal set and show commands but allow two normally
1748      independent variables to be either set or shown with a single
1749      command.  So the usual deprecated_add_set_cmd() and [deleted]
1750      add_show_from_set() commands aren't really appropriate. */
1751   /* FIXME: i18n: With the new add_setshow_integer command, that is no
1752      longer true - show can display anything.  */
1753   add_cmd ("radix", class_support, set_radix, _("\
1754 Set default input and output number radices.\n\
1755 Use 'set input-radix' or 'set output-radix' to independently set each.\n\
1756 Without an argument, sets both radices back to the default value of 10."),
1757 	   &setlist);
1758   add_cmd ("radix", class_support, show_radix, _("\
1759 Show the default input and output number radices.\n\
1760 Use 'show input-radix' or 'show output-radix' to independently show each."),
1761 	   &showlist);
1762 
1763   add_setshow_boolean_cmd ("array-indexes", class_support,
1764                            &user_print_options.print_array_indexes, _("\
1765 Set printing of array indexes."), _("\
1766 Show printing of array indexes"), NULL, NULL, show_print_array_indexes,
1767                            &setprintlist, &showprintlist);
1768 }
1769