xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/printcmd.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Print values for GNU debugger GDB.
2 
3    Copyright (C) 1986-2016 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 #include "defs.h"
21 #include "frame.h"
22 #include "symtab.h"
23 #include "gdbtypes.h"
24 #include "value.h"
25 #include "language.h"
26 #include "expression.h"
27 #include "gdbcore.h"
28 #include "gdbcmd.h"
29 #include "target.h"
30 #include "breakpoint.h"
31 #include "demangle.h"
32 #include "gdb-demangle.h"
33 #include "valprint.h"
34 #include "annotate.h"
35 #include "symfile.h"		/* for overlay functions */
36 #include "objfiles.h"		/* ditto */
37 #include "completer.h"		/* for completion functions */
38 #include "ui-out.h"
39 #include "block.h"
40 #include "disasm.h"
41 #include "dfp.h"
42 #include "observer.h"
43 #include "solist.h"
44 #include "parser-defs.h"
45 #include "charset.h"
46 #include "arch-utils.h"
47 #include "cli/cli-utils.h"
48 #include "format.h"
49 #include "source.h"
50 
51 #ifdef TUI
52 #include "tui/tui.h"		/* For tui_active et al.   */
53 #endif
54 
55 /* Last specified output format.  */
56 
57 static char last_format = 0;
58 
59 /* Last specified examination size.  'b', 'h', 'w' or `q'.  */
60 
61 static char last_size = 'w';
62 
63 /* Default address to examine next, and associated architecture.  */
64 
65 static struct gdbarch *next_gdbarch;
66 static CORE_ADDR next_address;
67 
68 /* Number of delay instructions following current disassembled insn.  */
69 
70 static int branch_delay_insns;
71 
72 /* Last address examined.  */
73 
74 static CORE_ADDR last_examine_address;
75 
76 /* Contents of last address examined.
77    This is not valid past the end of the `x' command!  */
78 
79 static struct value *last_examine_value;
80 
81 /* Largest offset between a symbolic value and an address, that will be
82    printed as `0x1234 <symbol+offset>'.  */
83 
84 static unsigned int max_symbolic_offset = UINT_MAX;
85 static void
86 show_max_symbolic_offset (struct ui_file *file, int from_tty,
87 			  struct cmd_list_element *c, const char *value)
88 {
89   fprintf_filtered (file,
90 		    _("The largest offset that will be "
91 		      "printed in <symbol+1234> form is %s.\n"),
92 		    value);
93 }
94 
95 /* Append the source filename and linenumber of the symbol when
96    printing a symbolic value as `<symbol at filename:linenum>' if set.  */
97 static int print_symbol_filename = 0;
98 static void
99 show_print_symbol_filename (struct ui_file *file, int from_tty,
100 			    struct cmd_list_element *c, const char *value)
101 {
102   fprintf_filtered (file, _("Printing of source filename and "
103 			    "line number with <symbol> is %s.\n"),
104 		    value);
105 }
106 
107 /* Number of auto-display expression currently being displayed.
108    So that we can disable it if we get a signal within it.
109    -1 when not doing one.  */
110 
111 static int current_display_number;
112 
113 struct display
114   {
115     /* Chain link to next auto-display item.  */
116     struct display *next;
117 
118     /* The expression as the user typed it.  */
119     char *exp_string;
120 
121     /* Expression to be evaluated and displayed.  */
122     struct expression *exp;
123 
124     /* Item number of this auto-display item.  */
125     int number;
126 
127     /* Display format specified.  */
128     struct format_data format;
129 
130     /* Program space associated with `block'.  */
131     struct program_space *pspace;
132 
133     /* Innermost block required by this expression when evaluated.  */
134     const struct block *block;
135 
136     /* Status of this display (enabled or disabled).  */
137     int enabled_p;
138   };
139 
140 /* Chain of expressions whose values should be displayed
141    automatically each time the program stops.  */
142 
143 static struct display *display_chain;
144 
145 static int display_number;
146 
147 /* Walk the following statement or block through all displays.
148    ALL_DISPLAYS_SAFE does so even if the statement deletes the current
149    display.  */
150 
151 #define ALL_DISPLAYS(B)				\
152   for (B = display_chain; B; B = B->next)
153 
154 #define ALL_DISPLAYS_SAFE(B,TMP)		\
155   for (B = display_chain;			\
156        B ? (TMP = B->next, 1): 0;		\
157        B = TMP)
158 
159 /* Prototypes for exported functions.  */
160 
161 void _initialize_printcmd (void);
162 
163 /* Prototypes for local functions.  */
164 
165 static void do_one_display (struct display *);
166 
167 
168 /* Decode a format specification.  *STRING_PTR should point to it.
169    OFORMAT and OSIZE are used as defaults for the format and size
170    if none are given in the format specification.
171    If OSIZE is zero, then the size field of the returned value
172    should be set only if a size is explicitly specified by the
173    user.
174    The structure returned describes all the data
175    found in the specification.  In addition, *STRING_PTR is advanced
176    past the specification and past all whitespace following it.  */
177 
178 static struct format_data
179 decode_format (const char **string_ptr, int oformat, int osize)
180 {
181   struct format_data val;
182   const char *p = *string_ptr;
183 
184   val.format = '?';
185   val.size = '?';
186   val.count = 1;
187   val.raw = 0;
188 
189   if (*p == '-')
190     {
191       val.count = -1;
192       p++;
193     }
194   if (*p >= '0' && *p <= '9')
195     val.count *= atoi (p);
196   while (*p >= '0' && *p <= '9')
197     p++;
198 
199   /* Now process size or format letters that follow.  */
200 
201   while (1)
202     {
203       if (*p == 'b' || *p == 'h' || *p == 'w' || *p == 'g')
204 	val.size = *p++;
205       else if (*p == 'r')
206 	{
207 	  val.raw = 1;
208 	  p++;
209 	}
210       else if (*p >= 'a' && *p <= 'z')
211 	val.format = *p++;
212       else
213 	break;
214     }
215 
216   while (*p == ' ' || *p == '\t')
217     p++;
218   *string_ptr = p;
219 
220   /* Set defaults for format and size if not specified.  */
221   if (val.format == '?')
222     {
223       if (val.size == '?')
224 	{
225 	  /* Neither has been specified.  */
226 	  val.format = oformat;
227 	  val.size = osize;
228 	}
229       else
230 	/* If a size is specified, any format makes a reasonable
231 	   default except 'i'.  */
232 	val.format = oformat == 'i' ? 'x' : oformat;
233     }
234   else if (val.size == '?')
235     switch (val.format)
236       {
237       case 'a':
238 	/* Pick the appropriate size for an address.  This is deferred
239 	   until do_examine when we know the actual architecture to use.
240 	   A special size value of 'a' is used to indicate this case.  */
241 	val.size = osize ? 'a' : osize;
242 	break;
243       case 'f':
244 	/* Floating point has to be word or giantword.  */
245 	if (osize == 'w' || osize == 'g')
246 	  val.size = osize;
247 	else
248 	  /* Default it to giantword if the last used size is not
249 	     appropriate.  */
250 	  val.size = osize ? 'g' : osize;
251 	break;
252       case 'c':
253 	/* Characters default to one byte.  */
254 	val.size = osize ? 'b' : osize;
255 	break;
256       case 's':
257 	/* Display strings with byte size chars unless explicitly
258 	   specified.  */
259 	val.size = '\0';
260 	break;
261 
262       default:
263 	/* The default is the size most recently specified.  */
264 	val.size = osize;
265       }
266 
267   return val;
268 }
269 
270 /* Print value VAL on stream according to OPTIONS.
271    Do not end with a newline.
272    SIZE is the letter for the size of datum being printed.
273    This is used to pad hex numbers so they line up.  SIZE is 0
274    for print / output and set for examine.  */
275 
276 static void
277 print_formatted (struct value *val, int size,
278 		 const struct value_print_options *options,
279 		 struct ui_file *stream)
280 {
281   struct type *type = check_typedef (value_type (val));
282   int len = TYPE_LENGTH (type);
283 
284   if (VALUE_LVAL (val) == lval_memory)
285     next_address = value_address (val) + len;
286 
287   if (size)
288     {
289       switch (options->format)
290 	{
291 	case 's':
292 	  {
293 	    struct type *elttype = value_type (val);
294 
295 	    next_address = (value_address (val)
296 			    + val_print_string (elttype, NULL,
297 						value_address (val), -1,
298 						stream, options) * len);
299 	  }
300 	  return;
301 
302 	case 'i':
303 	  /* We often wrap here if there are long symbolic names.  */
304 	  wrap_here ("    ");
305 	  next_address = (value_address (val)
306 			  + gdb_print_insn (get_type_arch (type),
307 					    value_address (val), stream,
308 					    &branch_delay_insns));
309 	  return;
310 	}
311     }
312 
313   if (options->format == 0 || options->format == 's'
314       || TYPE_CODE (type) == TYPE_CODE_REF
315       || TYPE_CODE (type) == TYPE_CODE_ARRAY
316       || TYPE_CODE (type) == TYPE_CODE_STRING
317       || TYPE_CODE (type) == TYPE_CODE_STRUCT
318       || TYPE_CODE (type) == TYPE_CODE_UNION
319       || TYPE_CODE (type) == TYPE_CODE_NAMESPACE)
320     value_print (val, stream, options);
321   else
322     /* User specified format, so don't look to the type to tell us
323        what to do.  */
324     val_print_scalar_formatted (type,
325 				value_contents_for_printing (val),
326 				value_embedded_offset (val),
327 				val,
328 				options, size, stream);
329 }
330 
331 /* Return builtin floating point type of same length as TYPE.
332    If no such type is found, return TYPE itself.  */
333 static struct type *
334 float_type_from_length (struct type *type)
335 {
336   struct gdbarch *gdbarch = get_type_arch (type);
337   const struct builtin_type *builtin = builtin_type (gdbarch);
338 
339   if (TYPE_LENGTH (type) == TYPE_LENGTH (builtin->builtin_float))
340     type = builtin->builtin_float;
341   else if (TYPE_LENGTH (type) == TYPE_LENGTH (builtin->builtin_double))
342     type = builtin->builtin_double;
343   else if (TYPE_LENGTH (type) == TYPE_LENGTH (builtin->builtin_long_double))
344     type = builtin->builtin_long_double;
345 
346   return type;
347 }
348 
349 /* Print a scalar of data of type TYPE, pointed to in GDB by VALADDR,
350    according to OPTIONS and SIZE on STREAM.  Formats s and i are not
351    supported at this level.  */
352 
353 void
354 print_scalar_formatted (const gdb_byte *valaddr, struct type *type,
355 			const struct value_print_options *options,
356 			int size, struct ui_file *stream)
357 {
358   struct gdbarch *gdbarch = get_type_arch (type);
359   LONGEST val_long = 0;
360   unsigned int len = TYPE_LENGTH (type);
361   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
362 
363   /* String printing should go through val_print_scalar_formatted.  */
364   gdb_assert (options->format != 's');
365 
366   if (len > sizeof(LONGEST)
367       && (TYPE_CODE (type) == TYPE_CODE_INT
368 	  || TYPE_CODE (type) == TYPE_CODE_ENUM))
369     {
370       switch (options->format)
371 	{
372 	case 'o':
373 	  print_octal_chars (stream, valaddr, len, byte_order);
374 	  return;
375 	case 'u':
376 	case 'd':
377 	  print_decimal_chars (stream, valaddr, len, byte_order);
378 	  return;
379 	case 't':
380 	  print_binary_chars (stream, valaddr, len, byte_order);
381 	  return;
382 	case 'x':
383 	  print_hex_chars (stream, valaddr, len, byte_order);
384 	  return;
385 	case 'c':
386 	  print_char_chars (stream, type, valaddr, len, byte_order);
387 	  return;
388 	default:
389 	  break;
390 	};
391     }
392 
393   if (options->format != 'f')
394     val_long = unpack_long (type, valaddr);
395 
396   /* If the value is a pointer, and pointers and addresses are not the
397      same, then at this point, the value's length (in target bytes) is
398      gdbarch_addr_bit/TARGET_CHAR_BIT, not TYPE_LENGTH (type).  */
399   if (TYPE_CODE (type) == TYPE_CODE_PTR)
400     len = gdbarch_addr_bit (gdbarch) / TARGET_CHAR_BIT;
401 
402   /* If we are printing it as unsigned, truncate it in case it is actually
403      a negative signed value (e.g. "print/u (short)-1" should print 65535
404      (if shorts are 16 bits) instead of 4294967295).  */
405   if (options->format != 'd' || TYPE_UNSIGNED (type))
406     {
407       if (len < sizeof (LONGEST))
408 	val_long &= ((LONGEST) 1 << HOST_CHAR_BIT * len) - 1;
409     }
410 
411   switch (options->format)
412     {
413     case 'x':
414       if (!size)
415 	{
416 	  /* No size specified, like in print.  Print varying # of digits.  */
417 	  print_longest (stream, 'x', 1, val_long);
418 	}
419       else
420 	switch (size)
421 	  {
422 	  case 'b':
423 	  case 'h':
424 	  case 'w':
425 	  case 'g':
426 	    print_longest (stream, size, 1, val_long);
427 	    break;
428 	  default:
429 	    error (_("Undefined output size \"%c\"."), size);
430 	  }
431       break;
432 
433     case 'd':
434       print_longest (stream, 'd', 1, val_long);
435       break;
436 
437     case 'u':
438       print_longest (stream, 'u', 0, val_long);
439       break;
440 
441     case 'o':
442       if (val_long)
443 	print_longest (stream, 'o', 1, val_long);
444       else
445 	fprintf_filtered (stream, "0");
446       break;
447 
448     case 'a':
449       {
450 	CORE_ADDR addr = unpack_pointer (type, valaddr);
451 
452 	print_address (gdbarch, addr, stream);
453       }
454       break;
455 
456     case 'c':
457       {
458 	struct value_print_options opts = *options;
459 
460 	opts.format = 0;
461 	if (TYPE_UNSIGNED (type))
462 	  type = builtin_type (gdbarch)->builtin_true_unsigned_char;
463  	else
464 	  type = builtin_type (gdbarch)->builtin_true_char;
465 
466 	value_print (value_from_longest (type, val_long), stream, &opts);
467       }
468       break;
469 
470     case 'f':
471       type = float_type_from_length (type);
472       print_floating (valaddr, type, stream);
473       break;
474 
475     case 0:
476       internal_error (__FILE__, __LINE__,
477 		      _("failed internal consistency check"));
478 
479     case 't':
480       /* Binary; 't' stands for "two".  */
481       {
482 	char bits[8 * (sizeof val_long) + 1];
483 	char buf[8 * (sizeof val_long) + 32];
484 	char *cp = bits;
485 	int width;
486 
487 	if (!size)
488 	  width = 8 * (sizeof val_long);
489 	else
490 	  switch (size)
491 	    {
492 	    case 'b':
493 	      width = 8;
494 	      break;
495 	    case 'h':
496 	      width = 16;
497 	      break;
498 	    case 'w':
499 	      width = 32;
500 	      break;
501 	    case 'g':
502 	      width = 64;
503 	      break;
504 	    default:
505 	      error (_("Undefined output size \"%c\"."), size);
506 	    }
507 
508 	bits[width] = '\0';
509 	while (width-- > 0)
510 	  {
511 	    bits[width] = (val_long & 1) ? '1' : '0';
512 	    val_long >>= 1;
513 	  }
514 	if (!size)
515 	  {
516 	    while (*cp && *cp == '0')
517 	      cp++;
518 	    if (*cp == '\0')
519 	      cp--;
520 	  }
521 	strncpy (buf, cp, sizeof (bits));
522 	fputs_filtered (buf, stream);
523       }
524       break;
525 
526     case 'z':
527       print_hex_chars (stream, valaddr, len, byte_order);
528       break;
529 
530     default:
531       error (_("Undefined output format \"%c\"."), options->format);
532     }
533 }
534 
535 /* Specify default address for `x' command.
536    The `info lines' command uses this.  */
537 
538 void
539 set_next_address (struct gdbarch *gdbarch, CORE_ADDR addr)
540 {
541   struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
542 
543   next_gdbarch = gdbarch;
544   next_address = addr;
545 
546   /* Make address available to the user as $_.  */
547   set_internalvar (lookup_internalvar ("_"),
548 		   value_from_pointer (ptr_type, addr));
549 }
550 
551 /* Optionally print address ADDR symbolically as <SYMBOL+OFFSET> on STREAM,
552    after LEADIN.  Print nothing if no symbolic name is found nearby.
553    Optionally also print source file and line number, if available.
554    DO_DEMANGLE controls whether to print a symbol in its native "raw" form,
555    or to interpret it as a possible C++ name and convert it back to source
556    form.  However note that DO_DEMANGLE can be overridden by the specific
557    settings of the demangle and asm_demangle variables.  Returns
558    non-zero if anything was printed; zero otherwise.  */
559 
560 int
561 print_address_symbolic (struct gdbarch *gdbarch, CORE_ADDR addr,
562 			struct ui_file *stream,
563 			int do_demangle, char *leadin)
564 {
565   char *name = NULL;
566   char *filename = NULL;
567   int unmapped = 0;
568   int offset = 0;
569   int line = 0;
570 
571   /* Throw away both name and filename.  */
572   struct cleanup *cleanup_chain = make_cleanup (free_current_contents, &name);
573   make_cleanup (free_current_contents, &filename);
574 
575   if (build_address_symbolic (gdbarch, addr, do_demangle, &name, &offset,
576 			      &filename, &line, &unmapped))
577     {
578       do_cleanups (cleanup_chain);
579       return 0;
580     }
581 
582   fputs_filtered (leadin, stream);
583   if (unmapped)
584     fputs_filtered ("<*", stream);
585   else
586     fputs_filtered ("<", stream);
587   fputs_filtered (name, stream);
588   if (offset != 0)
589     fprintf_filtered (stream, "+%u", (unsigned int) offset);
590 
591   /* Append source filename and line number if desired.  Give specific
592      line # of this addr, if we have it; else line # of the nearest symbol.  */
593   if (print_symbol_filename && filename != NULL)
594     {
595       if (line != -1)
596 	fprintf_filtered (stream, " at %s:%d", filename, line);
597       else
598 	fprintf_filtered (stream, " in %s", filename);
599     }
600   if (unmapped)
601     fputs_filtered ("*>", stream);
602   else
603     fputs_filtered (">", stream);
604 
605   do_cleanups (cleanup_chain);
606   return 1;
607 }
608 
609 /* Given an address ADDR return all the elements needed to print the
610    address in a symbolic form.  NAME can be mangled or not depending
611    on DO_DEMANGLE (and also on the asm_demangle global variable,
612    manipulated via ''set print asm-demangle'').  Return 0 in case of
613    success, when all the info in the OUT paramters is valid.  Return 1
614    otherwise.  */
615 int
616 build_address_symbolic (struct gdbarch *gdbarch,
617 			CORE_ADDR addr,  /* IN */
618 			int do_demangle, /* IN */
619 			char **name,     /* OUT */
620 			int *offset,     /* OUT */
621 			char **filename, /* OUT */
622 			int *line,       /* OUT */
623 			int *unmapped)   /* OUT */
624 {
625   struct bound_minimal_symbol msymbol;
626   struct symbol *symbol;
627   CORE_ADDR name_location = 0;
628   struct obj_section *section = NULL;
629   const char *name_temp = "";
630 
631   /* Let's say it is mapped (not unmapped).  */
632   *unmapped = 0;
633 
634   /* Determine if the address is in an overlay, and whether it is
635      mapped.  */
636   if (overlay_debugging)
637     {
638       section = find_pc_overlay (addr);
639       if (pc_in_unmapped_range (addr, section))
640 	{
641 	  *unmapped = 1;
642 	  addr = overlay_mapped_address (addr, section);
643 	}
644     }
645 
646   /* First try to find the address in the symbol table, then
647      in the minsyms.  Take the closest one.  */
648 
649   /* This is defective in the sense that it only finds text symbols.  So
650      really this is kind of pointless--we should make sure that the
651      minimal symbols have everything we need (by changing that we could
652      save some memory, but for many debug format--ELF/DWARF or
653      anything/stabs--it would be inconvenient to eliminate those minimal
654      symbols anyway).  */
655   msymbol = lookup_minimal_symbol_by_pc_section (addr, section);
656   symbol = find_pc_sect_function (addr, section);
657 
658   if (symbol)
659     {
660       /* If this is a function (i.e. a code address), strip out any
661 	 non-address bits.  For instance, display a pointer to the
662 	 first instruction of a Thumb function as <function>; the
663 	 second instruction will be <function+2>, even though the
664 	 pointer is <function+3>.  This matches the ISA behavior.  */
665       addr = gdbarch_addr_bits_remove (gdbarch, addr);
666 
667       name_location = BLOCK_START (SYMBOL_BLOCK_VALUE (symbol));
668       if (do_demangle || asm_demangle)
669 	name_temp = SYMBOL_PRINT_NAME (symbol);
670       else
671 	name_temp = SYMBOL_LINKAGE_NAME (symbol);
672     }
673 
674   if (msymbol.minsym != NULL
675       && MSYMBOL_HAS_SIZE (msymbol.minsym)
676       && MSYMBOL_SIZE (msymbol.minsym) == 0
677       && MSYMBOL_TYPE (msymbol.minsym) != mst_text
678       && MSYMBOL_TYPE (msymbol.minsym) != mst_text_gnu_ifunc
679       && MSYMBOL_TYPE (msymbol.minsym) != mst_file_text)
680     msymbol.minsym = NULL;
681 
682   if (msymbol.minsym != NULL)
683     {
684       if (BMSYMBOL_VALUE_ADDRESS (msymbol) > name_location || symbol == NULL)
685 	{
686 	  /* If this is a function (i.e. a code address), strip out any
687 	     non-address bits.  For instance, display a pointer to the
688 	     first instruction of a Thumb function as <function>; the
689 	     second instruction will be <function+2>, even though the
690 	     pointer is <function+3>.  This matches the ISA behavior.  */
691 	  if (MSYMBOL_TYPE (msymbol.minsym) == mst_text
692 	      || MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc
693 	      || MSYMBOL_TYPE (msymbol.minsym) == mst_file_text
694 	      || MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
695 	    addr = gdbarch_addr_bits_remove (gdbarch, addr);
696 
697 	  /* The msymbol is closer to the address than the symbol;
698 	     use the msymbol instead.  */
699 	  symbol = 0;
700 	  name_location = BMSYMBOL_VALUE_ADDRESS (msymbol);
701 	  if (do_demangle || asm_demangle)
702 	    name_temp = MSYMBOL_PRINT_NAME (msymbol.minsym);
703 	  else
704 	    name_temp = MSYMBOL_LINKAGE_NAME (msymbol.minsym);
705 	}
706     }
707   if (symbol == NULL && msymbol.minsym == NULL)
708     return 1;
709 
710   /* If the nearest symbol is too far away, don't print anything symbolic.  */
711 
712   /* For when CORE_ADDR is larger than unsigned int, we do math in
713      CORE_ADDR.  But when we detect unsigned wraparound in the
714      CORE_ADDR math, we ignore this test and print the offset,
715      because addr+max_symbolic_offset has wrapped through the end
716      of the address space back to the beginning, giving bogus comparison.  */
717   if (addr > name_location + max_symbolic_offset
718       && name_location + max_symbolic_offset > name_location)
719     return 1;
720 
721   *offset = addr - name_location;
722 
723   *name = xstrdup (name_temp);
724 
725   if (print_symbol_filename)
726     {
727       struct symtab_and_line sal;
728 
729       sal = find_pc_sect_line (addr, section, 0);
730 
731       if (sal.symtab)
732 	{
733 	  *filename = xstrdup (symtab_to_filename_for_display (sal.symtab));
734 	  *line = sal.line;
735 	}
736     }
737   return 0;
738 }
739 
740 
741 /* Print address ADDR symbolically on STREAM.
742    First print it as a number.  Then perhaps print
743    <SYMBOL + OFFSET> after the number.  */
744 
745 void
746 print_address (struct gdbarch *gdbarch,
747 	       CORE_ADDR addr, struct ui_file *stream)
748 {
749   fputs_filtered (paddress (gdbarch, addr), stream);
750   print_address_symbolic (gdbarch, addr, stream, asm_demangle, " ");
751 }
752 
753 /* Return a prefix for instruction address:
754    "=> " for current instruction, else "   ".  */
755 
756 const char *
757 pc_prefix (CORE_ADDR addr)
758 {
759   if (has_stack_frames ())
760     {
761       struct frame_info *frame;
762       CORE_ADDR pc;
763 
764       frame = get_selected_frame (NULL);
765       if (get_frame_pc_if_available (frame, &pc) && pc == addr)
766 	return "=> ";
767     }
768   return "   ";
769 }
770 
771 /* Print address ADDR symbolically on STREAM.  Parameter DEMANGLE
772    controls whether to print the symbolic name "raw" or demangled.
773    Return non-zero if anything was printed; zero otherwise.  */
774 
775 int
776 print_address_demangle (const struct value_print_options *opts,
777 			struct gdbarch *gdbarch, CORE_ADDR addr,
778 			struct ui_file *stream, int do_demangle)
779 {
780   if (opts->addressprint)
781     {
782       fputs_filtered (paddress (gdbarch, addr), stream);
783       print_address_symbolic (gdbarch, addr, stream, do_demangle, " ");
784     }
785   else
786     {
787       return print_address_symbolic (gdbarch, addr, stream, do_demangle, "");
788     }
789   return 1;
790 }
791 
792 
793 /* Find the address of the instruction that is INST_COUNT instructions before
794    the instruction at ADDR.
795    Since some architectures have variable-length instructions, we can't just
796    simply subtract INST_COUNT * INSN_LEN from ADDR.  Instead, we use line
797    number information to locate the nearest known instruction boundary,
798    and disassemble forward from there.  If we go out of the symbol range
799    during disassembling, we return the lowest address we've got so far and
800    set the number of instructions read to INST_READ.  */
801 
802 static CORE_ADDR
803 find_instruction_backward (struct gdbarch *gdbarch, CORE_ADDR addr,
804                            int inst_count, int *inst_read)
805 {
806   /* The vector PCS is used to store instruction addresses within
807      a pc range.  */
808   CORE_ADDR loop_start, loop_end, p;
809   VEC (CORE_ADDR) *pcs = NULL;
810   struct symtab_and_line sal;
811   struct cleanup *cleanup = make_cleanup (VEC_cleanup (CORE_ADDR), &pcs);
812 
813   *inst_read = 0;
814   loop_start = loop_end = addr;
815 
816   /* In each iteration of the outer loop, we get a pc range that ends before
817      LOOP_START, then we count and store every instruction address of the range
818      iterated in the loop.
819      If the number of instructions counted reaches INST_COUNT, return the
820      stored address that is located INST_COUNT instructions back from ADDR.
821      If INST_COUNT is not reached, we subtract the number of counted
822      instructions from INST_COUNT, and go to the next iteration.  */
823   do
824     {
825       VEC_truncate (CORE_ADDR, pcs, 0);
826       sal = find_pc_sect_line (loop_start, NULL, 1);
827       if (sal.line <= 0)
828         {
829           /* We reach here when line info is not available.  In this case,
830              we print a message and just exit the loop.  The return value
831              is calculated after the loop.  */
832           printf_filtered (_("No line number information available "
833                              "for address "));
834           wrap_here ("  ");
835           print_address (gdbarch, loop_start - 1, gdb_stdout);
836           printf_filtered ("\n");
837           break;
838         }
839 
840       loop_end = loop_start;
841       loop_start = sal.pc;
842 
843       /* This loop pushes instruction addresses in the range from
844          LOOP_START to LOOP_END.  */
845       for (p = loop_start; p < loop_end;)
846         {
847           VEC_safe_push (CORE_ADDR, pcs, p);
848           p += gdb_insn_length (gdbarch, p);
849         }
850 
851       inst_count -= VEC_length (CORE_ADDR, pcs);
852       *inst_read += VEC_length (CORE_ADDR, pcs);
853     }
854   while (inst_count > 0);
855 
856   /* After the loop, the vector PCS has instruction addresses of the last
857      source line we processed, and INST_COUNT has a negative value.
858      We return the address at the index of -INST_COUNT in the vector for
859      the reason below.
860      Let's assume the following instruction addresses and run 'x/-4i 0x400e'.
861        Line X of File
862           0x4000
863           0x4001
864           0x4005
865        Line Y of File
866           0x4009
867           0x400c
868        => 0x400e
869           0x4011
870      find_instruction_backward is called with INST_COUNT = 4 and expected to
871      return 0x4001.  When we reach here, INST_COUNT is set to -1 because
872      it was subtracted by 2 (from Line Y) and 3 (from Line X).  The value
873      4001 is located at the index 1 of the last iterated line (= Line X),
874      which is simply calculated by -INST_COUNT.
875      The case when the length of PCS is 0 means that we reached an area for
876      which line info is not available.  In such case, we return LOOP_START,
877      which was the lowest instruction address that had line info.  */
878   p = VEC_length (CORE_ADDR, pcs) > 0
879     ? VEC_index (CORE_ADDR, pcs, -inst_count)
880     : loop_start;
881 
882   /* INST_READ includes all instruction addresses in a pc range.  Need to
883      exclude the beginning part up to the address we're returning.  That
884      is, exclude {0x4000} in the example above.  */
885   if (inst_count < 0)
886     *inst_read += inst_count;
887 
888   do_cleanups (cleanup);
889   return p;
890 }
891 
892 /* Backward read LEN bytes of target memory from address MEMADDR + LEN,
893    placing the results in GDB's memory from MYADDR + LEN.  Returns
894    a count of the bytes actually read.  */
895 
896 static int
897 read_memory_backward (struct gdbarch *gdbarch,
898                       CORE_ADDR memaddr, gdb_byte *myaddr, int len)
899 {
900   int errcode;
901   int nread;      /* Number of bytes actually read.  */
902 
903   /* First try a complete read.  */
904   errcode = target_read_memory (memaddr, myaddr, len);
905   if (errcode == 0)
906     {
907       /* Got it all.  */
908       nread = len;
909     }
910   else
911     {
912       /* Loop, reading one byte at a time until we get as much as we can.  */
913       memaddr += len;
914       myaddr += len;
915       for (nread = 0; nread < len; ++nread)
916         {
917           errcode = target_read_memory (--memaddr, --myaddr, 1);
918           if (errcode != 0)
919             {
920               /* The read was unsuccessful, so exit the loop.  */
921               printf_filtered (_("Cannot access memory at address %s\n"),
922                                paddress (gdbarch, memaddr));
923               break;
924             }
925         }
926     }
927   return nread;
928 }
929 
930 /* Returns true if X (which is LEN bytes wide) is the number zero.  */
931 
932 static int
933 integer_is_zero (const gdb_byte *x, int len)
934 {
935   int i = 0;
936 
937   while (i < len && x[i] == 0)
938     ++i;
939   return (i == len);
940 }
941 
942 /* Find the start address of a string in which ADDR is included.
943    Basically we search for '\0' and return the next address,
944    but if OPTIONS->PRINT_MAX is smaller than the length of a string,
945    we stop searching and return the address to print characters as many as
946    PRINT_MAX from the string.  */
947 
948 static CORE_ADDR
949 find_string_backward (struct gdbarch *gdbarch,
950                       CORE_ADDR addr, int count, int char_size,
951                       const struct value_print_options *options,
952                       int *strings_counted)
953 {
954   const int chunk_size = 0x20;
955   gdb_byte *buffer = NULL;
956   struct cleanup *cleanup = NULL;
957   int read_error = 0;
958   int chars_read = 0;
959   int chars_to_read = chunk_size;
960   int chars_counted = 0;
961   int count_original = count;
962   CORE_ADDR string_start_addr = addr;
963 
964   gdb_assert (char_size == 1 || char_size == 2 || char_size == 4);
965   buffer = (gdb_byte *) xmalloc (chars_to_read * char_size);
966   cleanup = make_cleanup (xfree, buffer);
967   while (count > 0 && read_error == 0)
968     {
969       int i;
970 
971       addr -= chars_to_read * char_size;
972       chars_read = read_memory_backward (gdbarch, addr, buffer,
973                                          chars_to_read * char_size);
974       chars_read /= char_size;
975       read_error = (chars_read == chars_to_read) ? 0 : 1;
976       /* Searching for '\0' from the end of buffer in backward direction.  */
977       for (i = 0; i < chars_read && count > 0 ; ++i, ++chars_counted)
978         {
979           int offset = (chars_to_read - i - 1) * char_size;
980 
981           if (integer_is_zero (buffer + offset, char_size)
982               || chars_counted == options->print_max)
983             {
984               /* Found '\0' or reached print_max.  As OFFSET is the offset to
985                  '\0', we add CHAR_SIZE to return the start address of
986                  a string.  */
987               --count;
988               string_start_addr = addr + offset + char_size;
989               chars_counted = 0;
990             }
991         }
992     }
993 
994   /* Update STRINGS_COUNTED with the actual number of loaded strings.  */
995   *strings_counted = count_original - count;
996 
997   if (read_error != 0)
998     {
999       /* In error case, STRING_START_ADDR is pointing to the string that
1000          was last successfully loaded.  Rewind the partially loaded string.  */
1001       string_start_addr -= chars_counted * char_size;
1002     }
1003 
1004   do_cleanups (cleanup);
1005   return string_start_addr;
1006 }
1007 
1008 /* Examine data at address ADDR in format FMT.
1009    Fetch it from memory and print on gdb_stdout.  */
1010 
1011 static void
1012 do_examine (struct format_data fmt, struct gdbarch *gdbarch, CORE_ADDR addr)
1013 {
1014   char format = 0;
1015   char size;
1016   int count = 1;
1017   struct type *val_type = NULL;
1018   int i;
1019   int maxelts;
1020   struct value_print_options opts;
1021   int need_to_update_next_address = 0;
1022   CORE_ADDR addr_rewound = 0;
1023 
1024   format = fmt.format;
1025   size = fmt.size;
1026   count = fmt.count;
1027   next_gdbarch = gdbarch;
1028   next_address = addr;
1029 
1030   /* Instruction format implies fetch single bytes
1031      regardless of the specified size.
1032      The case of strings is handled in decode_format, only explicit
1033      size operator are not changed to 'b'.  */
1034   if (format == 'i')
1035     size = 'b';
1036 
1037   if (size == 'a')
1038     {
1039       /* Pick the appropriate size for an address.  */
1040       if (gdbarch_ptr_bit (next_gdbarch) == 64)
1041 	size = 'g';
1042       else if (gdbarch_ptr_bit (next_gdbarch) == 32)
1043 	size = 'w';
1044       else if (gdbarch_ptr_bit (next_gdbarch) == 16)
1045 	size = 'h';
1046       else
1047 	/* Bad value for gdbarch_ptr_bit.  */
1048 	internal_error (__FILE__, __LINE__,
1049 			_("failed internal consistency check"));
1050     }
1051 
1052   if (size == 'b')
1053     val_type = builtin_type (next_gdbarch)->builtin_int8;
1054   else if (size == 'h')
1055     val_type = builtin_type (next_gdbarch)->builtin_int16;
1056   else if (size == 'w')
1057     val_type = builtin_type (next_gdbarch)->builtin_int32;
1058   else if (size == 'g')
1059     val_type = builtin_type (next_gdbarch)->builtin_int64;
1060 
1061   if (format == 's')
1062     {
1063       struct type *char_type = NULL;
1064 
1065       /* Search for "char16_t"  or "char32_t" types or fall back to 8-bit char
1066 	 if type is not found.  */
1067       if (size == 'h')
1068 	char_type = builtin_type (next_gdbarch)->builtin_char16;
1069       else if (size == 'w')
1070 	char_type = builtin_type (next_gdbarch)->builtin_char32;
1071       if (char_type)
1072         val_type = char_type;
1073       else
1074         {
1075 	  if (size != '\0' && size != 'b')
1076 	    warning (_("Unable to display strings with "
1077 		       "size '%c', using 'b' instead."), size);
1078 	  size = 'b';
1079 	  val_type = builtin_type (next_gdbarch)->builtin_int8;
1080         }
1081     }
1082 
1083   maxelts = 8;
1084   if (size == 'w')
1085     maxelts = 4;
1086   if (size == 'g')
1087     maxelts = 2;
1088   if (format == 's' || format == 'i')
1089     maxelts = 1;
1090 
1091   get_formatted_print_options (&opts, format);
1092 
1093   if (count < 0)
1094     {
1095       /* This is the negative repeat count case.
1096          We rewind the address based on the given repeat count and format,
1097          then examine memory from there in forward direction.  */
1098 
1099       count = -count;
1100       if (format == 'i')
1101         {
1102           next_address = find_instruction_backward (gdbarch, addr, count,
1103                                                     &count);
1104         }
1105       else if (format == 's')
1106         {
1107           next_address = find_string_backward (gdbarch, addr, count,
1108                                                TYPE_LENGTH (val_type),
1109                                                &opts, &count);
1110         }
1111       else
1112         {
1113           next_address = addr - count * TYPE_LENGTH (val_type);
1114         }
1115 
1116       /* The following call to print_formatted updates next_address in every
1117          iteration.  In backward case, we store the start address here
1118          and update next_address with it before exiting the function.  */
1119       addr_rewound = (format == 's'
1120                       ? next_address - TYPE_LENGTH (val_type)
1121                       : next_address);
1122       need_to_update_next_address = 1;
1123     }
1124 
1125   /* Print as many objects as specified in COUNT, at most maxelts per line,
1126      with the address of the next one at the start of each line.  */
1127 
1128   while (count > 0)
1129     {
1130       QUIT;
1131       if (format == 'i')
1132 	fputs_filtered (pc_prefix (next_address), gdb_stdout);
1133       print_address (next_gdbarch, next_address, gdb_stdout);
1134       printf_filtered (":");
1135       for (i = maxelts;
1136 	   i > 0 && count > 0;
1137 	   i--, count--)
1138 	{
1139 	  printf_filtered ("\t");
1140 	  /* Note that print_formatted sets next_address for the next
1141 	     object.  */
1142 	  last_examine_address = next_address;
1143 
1144 	  if (last_examine_value)
1145 	    value_free (last_examine_value);
1146 
1147 	  /* The value to be displayed is not fetched greedily.
1148 	     Instead, to avoid the possibility of a fetched value not
1149 	     being used, its retrieval is delayed until the print code
1150 	     uses it.  When examining an instruction stream, the
1151 	     disassembler will perform its own memory fetch using just
1152 	     the address stored in LAST_EXAMINE_VALUE.  FIXME: Should
1153 	     the disassembler be modified so that LAST_EXAMINE_VALUE
1154 	     is left with the byte sequence from the last complete
1155 	     instruction fetched from memory?  */
1156 	  last_examine_value = value_at_lazy (val_type, next_address);
1157 
1158 	  if (last_examine_value)
1159 	    release_value (last_examine_value);
1160 
1161 	  print_formatted (last_examine_value, size, &opts, gdb_stdout);
1162 
1163 	  /* Display any branch delay slots following the final insn.  */
1164 	  if (format == 'i' && count == 1)
1165 	    count += branch_delay_insns;
1166 	}
1167       printf_filtered ("\n");
1168       gdb_flush (gdb_stdout);
1169     }
1170 
1171   if (need_to_update_next_address)
1172     next_address = addr_rewound;
1173 }
1174 
1175 static void
1176 validate_format (struct format_data fmt, const char *cmdname)
1177 {
1178   if (fmt.size != 0)
1179     error (_("Size letters are meaningless in \"%s\" command."), cmdname);
1180   if (fmt.count != 1)
1181     error (_("Item count other than 1 is meaningless in \"%s\" command."),
1182 	   cmdname);
1183   if (fmt.format == 'i')
1184     error (_("Format letter \"%c\" is meaningless in \"%s\" command."),
1185 	   fmt.format, cmdname);
1186 }
1187 
1188 /* Parse print command format string into *FMTP and update *EXPP.
1189    CMDNAME should name the current command.  */
1190 
1191 void
1192 print_command_parse_format (const char **expp, const char *cmdname,
1193 			    struct format_data *fmtp)
1194 {
1195   const char *exp = *expp;
1196 
1197   if (exp && *exp == '/')
1198     {
1199       exp++;
1200       *fmtp = decode_format (&exp, last_format, 0);
1201       validate_format (*fmtp, cmdname);
1202       last_format = fmtp->format;
1203     }
1204   else
1205     {
1206       fmtp->count = 1;
1207       fmtp->format = 0;
1208       fmtp->size = 0;
1209       fmtp->raw = 0;
1210     }
1211 
1212   *expp = exp;
1213 }
1214 
1215 /* Print VAL to console according to *FMTP, including recording it to
1216    the history.  */
1217 
1218 void
1219 print_value (struct value *val, const struct format_data *fmtp)
1220 {
1221   struct value_print_options opts;
1222   int histindex = record_latest_value (val);
1223 
1224   annotate_value_history_begin (histindex, value_type (val));
1225 
1226   printf_filtered ("$%d = ", histindex);
1227 
1228   annotate_value_history_value ();
1229 
1230   get_formatted_print_options (&opts, fmtp->format);
1231   opts.raw = fmtp->raw;
1232 
1233   print_formatted (val, fmtp->size, &opts, gdb_stdout);
1234   printf_filtered ("\n");
1235 
1236   annotate_value_history_end ();
1237 }
1238 
1239 /* Evaluate string EXP as an expression in the current language and
1240    print the resulting value.  EXP may contain a format specifier as the
1241    first argument ("/x myvar" for example, to print myvar in hex).  */
1242 
1243 static void
1244 print_command_1 (const char *exp, int voidprint)
1245 {
1246   struct expression *expr;
1247   struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
1248   struct value *val;
1249   struct format_data fmt;
1250 
1251   print_command_parse_format (&exp, "print", &fmt);
1252 
1253   if (exp && *exp)
1254     {
1255       expr = parse_expression (exp);
1256       make_cleanup (free_current_contents, &expr);
1257       val = evaluate_expression (expr);
1258     }
1259   else
1260     val = access_value_history (0);
1261 
1262   if (voidprint || (val && value_type (val) &&
1263 		    TYPE_CODE (value_type (val)) != TYPE_CODE_VOID))
1264     print_value (val, &fmt);
1265 
1266   do_cleanups (old_chain);
1267 }
1268 
1269 static void
1270 print_command (char *exp, int from_tty)
1271 {
1272   print_command_1 (exp, 1);
1273 }
1274 
1275 /* Same as print, except it doesn't print void results.  */
1276 static void
1277 call_command (char *exp, int from_tty)
1278 {
1279   print_command_1 (exp, 0);
1280 }
1281 
1282 /* Implementation of the "output" command.  */
1283 
1284 static void
1285 output_command (char *exp, int from_tty)
1286 {
1287   output_command_const (exp, from_tty);
1288 }
1289 
1290 /* Like output_command, but takes a const string as argument.  */
1291 
1292 void
1293 output_command_const (const char *exp, int from_tty)
1294 {
1295   struct expression *expr;
1296   struct cleanup *old_chain;
1297   char format = 0;
1298   struct value *val;
1299   struct format_data fmt;
1300   struct value_print_options opts;
1301 
1302   fmt.size = 0;
1303   fmt.raw = 0;
1304 
1305   if (exp && *exp == '/')
1306     {
1307       exp++;
1308       fmt = decode_format (&exp, 0, 0);
1309       validate_format (fmt, "output");
1310       format = fmt.format;
1311     }
1312 
1313   expr = parse_expression (exp);
1314   old_chain = make_cleanup (free_current_contents, &expr);
1315 
1316   val = evaluate_expression (expr);
1317 
1318   annotate_value_begin (value_type (val));
1319 
1320   get_formatted_print_options (&opts, format);
1321   opts.raw = fmt.raw;
1322   print_formatted (val, fmt.size, &opts, gdb_stdout);
1323 
1324   annotate_value_end ();
1325 
1326   wrap_here ("");
1327   gdb_flush (gdb_stdout);
1328 
1329   do_cleanups (old_chain);
1330 }
1331 
1332 static void
1333 set_command (char *exp, int from_tty)
1334 {
1335   struct expression *expr = parse_expression (exp);
1336   struct cleanup *old_chain =
1337     make_cleanup (free_current_contents, &expr);
1338 
1339   if (expr->nelts >= 1)
1340     switch (expr->elts[0].opcode)
1341       {
1342       case UNOP_PREINCREMENT:
1343       case UNOP_POSTINCREMENT:
1344       case UNOP_PREDECREMENT:
1345       case UNOP_POSTDECREMENT:
1346       case BINOP_ASSIGN:
1347       case BINOP_ASSIGN_MODIFY:
1348       case BINOP_COMMA:
1349 	break;
1350       default:
1351 	warning
1352 	  (_("Expression is not an assignment (and might have no effect)"));
1353       }
1354 
1355   evaluate_expression (expr);
1356   do_cleanups (old_chain);
1357 }
1358 
1359 static void
1360 sym_info (char *arg, int from_tty)
1361 {
1362   struct minimal_symbol *msymbol;
1363   struct objfile *objfile;
1364   struct obj_section *osect;
1365   CORE_ADDR addr, sect_addr;
1366   int matches = 0;
1367   unsigned int offset;
1368 
1369   if (!arg)
1370     error_no_arg (_("address"));
1371 
1372   addr = parse_and_eval_address (arg);
1373   ALL_OBJSECTIONS (objfile, osect)
1374   {
1375     /* Only process each object file once, even if there's a separate
1376        debug file.  */
1377     if (objfile->separate_debug_objfile_backlink)
1378       continue;
1379 
1380     sect_addr = overlay_mapped_address (addr, osect);
1381 
1382     if (obj_section_addr (osect) <= sect_addr
1383 	&& sect_addr < obj_section_endaddr (osect)
1384 	&& (msymbol
1385 	    = lookup_minimal_symbol_by_pc_section (sect_addr, osect).minsym))
1386       {
1387 	const char *obj_name, *mapped, *sec_name, *msym_name;
1388 	char *loc_string;
1389 	struct cleanup *old_chain;
1390 
1391 	matches = 1;
1392 	offset = sect_addr - MSYMBOL_VALUE_ADDRESS (objfile, msymbol);
1393 	mapped = section_is_mapped (osect) ? _("mapped") : _("unmapped");
1394 	sec_name = osect->the_bfd_section->name;
1395 	msym_name = MSYMBOL_PRINT_NAME (msymbol);
1396 
1397 	/* Don't print the offset if it is zero.
1398 	   We assume there's no need to handle i18n of "sym + offset".  */
1399 	if (offset)
1400 	  loc_string = xstrprintf ("%s + %u", msym_name, offset);
1401 	else
1402 	  loc_string = xstrprintf ("%s", msym_name);
1403 
1404 	/* Use a cleanup to free loc_string in case the user quits
1405 	   a pagination request inside printf_filtered.  */
1406 	old_chain = make_cleanup (xfree, loc_string);
1407 
1408 	gdb_assert (osect->objfile && objfile_name (osect->objfile));
1409 	obj_name = objfile_name (osect->objfile);
1410 
1411 	if (MULTI_OBJFILE_P ())
1412 	  if (pc_in_unmapped_range (addr, osect))
1413 	    if (section_is_overlay (osect))
1414 	      printf_filtered (_("%s in load address range of "
1415 				 "%s overlay section %s of %s\n"),
1416 			       loc_string, mapped, sec_name, obj_name);
1417 	    else
1418 	      printf_filtered (_("%s in load address range of "
1419 				 "section %s of %s\n"),
1420 			       loc_string, sec_name, obj_name);
1421 	  else
1422 	    if (section_is_overlay (osect))
1423 	      printf_filtered (_("%s in %s overlay section %s of %s\n"),
1424 			       loc_string, mapped, sec_name, obj_name);
1425 	    else
1426 	      printf_filtered (_("%s in section %s of %s\n"),
1427 			       loc_string, sec_name, obj_name);
1428 	else
1429 	  if (pc_in_unmapped_range (addr, osect))
1430 	    if (section_is_overlay (osect))
1431 	      printf_filtered (_("%s in load address range of %s overlay "
1432 				 "section %s\n"),
1433 			       loc_string, mapped, sec_name);
1434 	    else
1435 	      printf_filtered (_("%s in load address range of section %s\n"),
1436 			       loc_string, sec_name);
1437 	  else
1438 	    if (section_is_overlay (osect))
1439 	      printf_filtered (_("%s in %s overlay section %s\n"),
1440 			       loc_string, mapped, sec_name);
1441 	    else
1442 	      printf_filtered (_("%s in section %s\n"),
1443 			       loc_string, sec_name);
1444 
1445 	do_cleanups (old_chain);
1446       }
1447   }
1448   if (matches == 0)
1449     printf_filtered (_("No symbol matches %s.\n"), arg);
1450 }
1451 
1452 static void
1453 address_info (char *exp, int from_tty)
1454 {
1455   struct gdbarch *gdbarch;
1456   int regno;
1457   struct symbol *sym;
1458   struct bound_minimal_symbol msymbol;
1459   long val;
1460   struct obj_section *section;
1461   CORE_ADDR load_addr, context_pc = 0;
1462   struct field_of_this_result is_a_field_of_this;
1463 
1464   if (exp == 0)
1465     error (_("Argument required."));
1466 
1467   sym = lookup_symbol (exp, get_selected_block (&context_pc), VAR_DOMAIN,
1468 		       &is_a_field_of_this).symbol;
1469   if (sym == NULL)
1470     {
1471       if (is_a_field_of_this.type != NULL)
1472 	{
1473 	  printf_filtered ("Symbol \"");
1474 	  fprintf_symbol_filtered (gdb_stdout, exp,
1475 				   current_language->la_language, DMGL_ANSI);
1476 	  printf_filtered ("\" is a field of the local class variable ");
1477 	  if (current_language->la_language == language_objc)
1478 	    printf_filtered ("`self'\n");	/* ObjC equivalent of "this" */
1479 	  else
1480 	    printf_filtered ("`this'\n");
1481 	  return;
1482 	}
1483 
1484       msymbol = lookup_bound_minimal_symbol (exp);
1485 
1486       if (msymbol.minsym != NULL)
1487 	{
1488 	  struct objfile *objfile = msymbol.objfile;
1489 
1490 	  gdbarch = get_objfile_arch (objfile);
1491 	  load_addr = BMSYMBOL_VALUE_ADDRESS (msymbol);
1492 
1493 	  printf_filtered ("Symbol \"");
1494 	  fprintf_symbol_filtered (gdb_stdout, exp,
1495 				   current_language->la_language, DMGL_ANSI);
1496 	  printf_filtered ("\" is at ");
1497 	  fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1498 	  printf_filtered (" in a file compiled without debugging");
1499 	  section = MSYMBOL_OBJ_SECTION (objfile, msymbol.minsym);
1500 	  if (section_is_overlay (section))
1501 	    {
1502 	      load_addr = overlay_unmapped_address (load_addr, section);
1503 	      printf_filtered (",\n -- loaded at ");
1504 	      fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1505 	      printf_filtered (" in overlay section %s",
1506 			       section->the_bfd_section->name);
1507 	    }
1508 	  printf_filtered (".\n");
1509 	}
1510       else
1511 	error (_("No symbol \"%s\" in current context."), exp);
1512       return;
1513     }
1514 
1515   printf_filtered ("Symbol \"");
1516   fprintf_symbol_filtered (gdb_stdout, SYMBOL_PRINT_NAME (sym),
1517 			   current_language->la_language, DMGL_ANSI);
1518   printf_filtered ("\" is ");
1519   val = SYMBOL_VALUE (sym);
1520   if (SYMBOL_OBJFILE_OWNED (sym))
1521     section = SYMBOL_OBJ_SECTION (symbol_objfile (sym), sym);
1522   else
1523     section = NULL;
1524   gdbarch = symbol_arch (sym);
1525 
1526   if (SYMBOL_COMPUTED_OPS (sym) != NULL)
1527     {
1528       SYMBOL_COMPUTED_OPS (sym)->describe_location (sym, context_pc,
1529 						    gdb_stdout);
1530       printf_filtered (".\n");
1531       return;
1532     }
1533 
1534   switch (SYMBOL_CLASS (sym))
1535     {
1536     case LOC_CONST:
1537     case LOC_CONST_BYTES:
1538       printf_filtered ("constant");
1539       break;
1540 
1541     case LOC_LABEL:
1542       printf_filtered ("a label at address ");
1543       load_addr = SYMBOL_VALUE_ADDRESS (sym);
1544       fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1545       if (section_is_overlay (section))
1546 	{
1547 	  load_addr = overlay_unmapped_address (load_addr, section);
1548 	  printf_filtered (",\n -- loaded at ");
1549 	  fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1550 	  printf_filtered (" in overlay section %s",
1551 			   section->the_bfd_section->name);
1552 	}
1553       break;
1554 
1555     case LOC_COMPUTED:
1556       gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
1557 
1558     case LOC_REGISTER:
1559       /* GDBARCH is the architecture associated with the objfile the symbol
1560 	 is defined in; the target architecture may be different, and may
1561 	 provide additional registers.  However, we do not know the target
1562 	 architecture at this point.  We assume the objfile architecture
1563 	 will contain all the standard registers that occur in debug info
1564 	 in that objfile.  */
1565       regno = SYMBOL_REGISTER_OPS (sym)->register_number (sym, gdbarch);
1566 
1567       if (SYMBOL_IS_ARGUMENT (sym))
1568 	printf_filtered (_("an argument in register %s"),
1569 			 gdbarch_register_name (gdbarch, regno));
1570       else
1571 	printf_filtered (_("a variable in register %s"),
1572 			 gdbarch_register_name (gdbarch, regno));
1573       break;
1574 
1575     case LOC_STATIC:
1576       printf_filtered (_("static storage at address "));
1577       load_addr = SYMBOL_VALUE_ADDRESS (sym);
1578       fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1579       if (section_is_overlay (section))
1580 	{
1581 	  load_addr = overlay_unmapped_address (load_addr, section);
1582 	  printf_filtered (_(",\n -- loaded at "));
1583 	  fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1584 	  printf_filtered (_(" in overlay section %s"),
1585 			   section->the_bfd_section->name);
1586 	}
1587       break;
1588 
1589     case LOC_REGPARM_ADDR:
1590       /* Note comment at LOC_REGISTER.  */
1591       regno = SYMBOL_REGISTER_OPS (sym)->register_number (sym, gdbarch);
1592       printf_filtered (_("address of an argument in register %s"),
1593 		       gdbarch_register_name (gdbarch, regno));
1594       break;
1595 
1596     case LOC_ARG:
1597       printf_filtered (_("an argument at offset %ld"), val);
1598       break;
1599 
1600     case LOC_LOCAL:
1601       printf_filtered (_("a local variable at frame offset %ld"), val);
1602       break;
1603 
1604     case LOC_REF_ARG:
1605       printf_filtered (_("a reference argument at offset %ld"), val);
1606       break;
1607 
1608     case LOC_TYPEDEF:
1609       printf_filtered (_("a typedef"));
1610       break;
1611 
1612     case LOC_BLOCK:
1613       printf_filtered (_("a function at address "));
1614       load_addr = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
1615       fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1616       if (section_is_overlay (section))
1617 	{
1618 	  load_addr = overlay_unmapped_address (load_addr, section);
1619 	  printf_filtered (_(",\n -- loaded at "));
1620 	  fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1621 	  printf_filtered (_(" in overlay section %s"),
1622 			   section->the_bfd_section->name);
1623 	}
1624       break;
1625 
1626     case LOC_UNRESOLVED:
1627       {
1628 	struct bound_minimal_symbol msym;
1629 
1630 	msym = lookup_minimal_symbol_and_objfile (SYMBOL_LINKAGE_NAME (sym));
1631 	if (msym.minsym == NULL)
1632 	  printf_filtered ("unresolved");
1633 	else
1634 	  {
1635 	    section = MSYMBOL_OBJ_SECTION (msym.objfile, msym.minsym);
1636 
1637 	    if (section
1638 		&& (section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0)
1639 	      {
1640 		load_addr = MSYMBOL_VALUE_RAW_ADDRESS (msym.minsym);
1641 		printf_filtered (_("a thread-local variable at offset %s "
1642 				   "in the thread-local storage for `%s'"),
1643 				 paddress (gdbarch, load_addr),
1644 				 objfile_name (section->objfile));
1645 	      }
1646 	    else
1647 	      {
1648 		load_addr = BMSYMBOL_VALUE_ADDRESS (msym);
1649 		printf_filtered (_("static storage at address "));
1650 		fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1651 		if (section_is_overlay (section))
1652 		  {
1653 		    load_addr = overlay_unmapped_address (load_addr, section);
1654 		    printf_filtered (_(",\n -- loaded at "));
1655 		    fputs_filtered (paddress (gdbarch, load_addr), gdb_stdout);
1656 		    printf_filtered (_(" in overlay section %s"),
1657 				     section->the_bfd_section->name);
1658 		  }
1659 	      }
1660 	  }
1661       }
1662       break;
1663 
1664     case LOC_OPTIMIZED_OUT:
1665       printf_filtered (_("optimized out"));
1666       break;
1667 
1668     default:
1669       printf_filtered (_("of unknown (botched) type"));
1670       break;
1671     }
1672   printf_filtered (".\n");
1673 }
1674 
1675 
1676 static void
1677 x_command (char *exp, int from_tty)
1678 {
1679   struct expression *expr;
1680   struct format_data fmt;
1681   struct cleanup *old_chain;
1682   struct value *val;
1683 
1684   fmt.format = last_format ? last_format : 'x';
1685   fmt.size = last_size;
1686   fmt.count = 1;
1687   fmt.raw = 0;
1688 
1689   if (exp && *exp == '/')
1690     {
1691       const char *tmp = exp + 1;
1692 
1693       fmt = decode_format (&tmp, last_format, last_size);
1694       exp = (char *) tmp;
1695     }
1696 
1697   /* If we have an expression, evaluate it and use it as the address.  */
1698 
1699   if (exp != 0 && *exp != 0)
1700     {
1701       expr = parse_expression (exp);
1702       /* Cause expression not to be there any more if this command is
1703          repeated with Newline.  But don't clobber a user-defined
1704          command's definition.  */
1705       if (from_tty)
1706 	*exp = 0;
1707       old_chain = make_cleanup (free_current_contents, &expr);
1708       val = evaluate_expression (expr);
1709       if (TYPE_CODE (value_type (val)) == TYPE_CODE_REF)
1710 	val = coerce_ref (val);
1711       /* In rvalue contexts, such as this, functions are coerced into
1712          pointers to functions.  This makes "x/i main" work.  */
1713       if (/* last_format == 'i'  && */
1714 	  TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
1715 	   && VALUE_LVAL (val) == lval_memory)
1716 	next_address = value_address (val);
1717       else
1718 	next_address = value_as_address (val);
1719 
1720       next_gdbarch = expr->gdbarch;
1721       do_cleanups (old_chain);
1722     }
1723 
1724   if (!next_gdbarch)
1725     error_no_arg (_("starting display address"));
1726 
1727   do_examine (fmt, next_gdbarch, next_address);
1728 
1729   /* If the examine succeeds, we remember its size and format for next
1730      time.  Set last_size to 'b' for strings.  */
1731   if (fmt.format == 's')
1732     last_size = 'b';
1733   else
1734     last_size = fmt.size;
1735   last_format = fmt.format;
1736 
1737   /* Set a couple of internal variables if appropriate.  */
1738   if (last_examine_value)
1739     {
1740       /* Make last address examined available to the user as $_.  Use
1741          the correct pointer type.  */
1742       struct type *pointer_type
1743 	= lookup_pointer_type (value_type (last_examine_value));
1744       set_internalvar (lookup_internalvar ("_"),
1745 		       value_from_pointer (pointer_type,
1746 					   last_examine_address));
1747 
1748       /* Make contents of last address examined available to the user
1749 	 as $__.  If the last value has not been fetched from memory
1750 	 then don't fetch it now; instead mark it by voiding the $__
1751 	 variable.  */
1752       if (value_lazy (last_examine_value))
1753 	clear_internalvar (lookup_internalvar ("__"));
1754       else
1755 	set_internalvar (lookup_internalvar ("__"), last_examine_value);
1756     }
1757 }
1758 
1759 
1760 /* Add an expression to the auto-display chain.
1761    Specify the expression.  */
1762 
1763 static void
1764 display_command (char *arg, int from_tty)
1765 {
1766   struct format_data fmt;
1767   struct expression *expr;
1768   struct display *newobj;
1769   const char *exp = arg;
1770 
1771   if (exp == 0)
1772     {
1773       do_displays ();
1774       return;
1775     }
1776 
1777   if (*exp == '/')
1778     {
1779       exp++;
1780       fmt = decode_format (&exp, 0, 0);
1781       if (fmt.size && fmt.format == 0)
1782 	fmt.format = 'x';
1783       if (fmt.format == 'i' || fmt.format == 's')
1784 	fmt.size = 'b';
1785     }
1786   else
1787     {
1788       fmt.format = 0;
1789       fmt.size = 0;
1790       fmt.count = 0;
1791       fmt.raw = 0;
1792     }
1793 
1794   innermost_block = NULL;
1795   expr = parse_expression (exp);
1796 
1797   newobj = XNEW (struct display);
1798 
1799   newobj->exp_string = xstrdup (exp);
1800   newobj->exp = expr;
1801   newobj->block = innermost_block;
1802   newobj->pspace = current_program_space;
1803   newobj->number = ++display_number;
1804   newobj->format = fmt;
1805   newobj->enabled_p = 1;
1806   newobj->next = NULL;
1807 
1808   if (display_chain == NULL)
1809     display_chain = newobj;
1810   else
1811     {
1812       struct display *last;
1813 
1814       for (last = display_chain; last->next != NULL; last = last->next)
1815 	;
1816       last->next = newobj;
1817     }
1818 
1819   if (from_tty)
1820     do_one_display (newobj);
1821 
1822   dont_repeat ();
1823 }
1824 
1825 static void
1826 free_display (struct display *d)
1827 {
1828   xfree (d->exp_string);
1829   xfree (d->exp);
1830   xfree (d);
1831 }
1832 
1833 /* Clear out the display_chain.  Done when new symtabs are loaded,
1834    since this invalidates the types stored in many expressions.  */
1835 
1836 void
1837 clear_displays (void)
1838 {
1839   struct display *d;
1840 
1841   while ((d = display_chain) != NULL)
1842     {
1843       display_chain = d->next;
1844       free_display (d);
1845     }
1846 }
1847 
1848 /* Delete the auto-display DISPLAY.  */
1849 
1850 static void
1851 delete_display (struct display *display)
1852 {
1853   struct display *d;
1854 
1855   gdb_assert (display != NULL);
1856 
1857   if (display_chain == display)
1858     display_chain = display->next;
1859 
1860   ALL_DISPLAYS (d)
1861     if (d->next == display)
1862       {
1863 	d->next = display->next;
1864 	break;
1865       }
1866 
1867   free_display (display);
1868 }
1869 
1870 /* Call FUNCTION on each of the displays whose numbers are given in
1871    ARGS.  DATA is passed unmodified to FUNCTION.  */
1872 
1873 static void
1874 map_display_numbers (char *args,
1875 		     void (*function) (struct display *,
1876 				       void *),
1877 		     void *data)
1878 {
1879   struct get_number_or_range_state state;
1880   int num;
1881 
1882   if (args == NULL)
1883     error_no_arg (_("one or more display numbers"));
1884 
1885   init_number_or_range (&state, args);
1886 
1887   while (!state.finished)
1888     {
1889       const char *p = state.string;
1890 
1891       num = get_number_or_range (&state);
1892       if (num == 0)
1893 	warning (_("bad display number at or near '%s'"), p);
1894       else
1895 	{
1896 	  struct display *d, *tmp;
1897 
1898 	  ALL_DISPLAYS_SAFE (d, tmp)
1899 	    if (d->number == num)
1900 	      break;
1901 	  if (d == NULL)
1902 	    printf_unfiltered (_("No display number %d.\n"), num);
1903 	  else
1904 	    function (d, data);
1905 	}
1906     }
1907 }
1908 
1909 /* Callback for map_display_numbers, that deletes a display.  */
1910 
1911 static void
1912 do_delete_display (struct display *d, void *data)
1913 {
1914   delete_display (d);
1915 }
1916 
1917 /* "undisplay" command.  */
1918 
1919 static void
1920 undisplay_command (char *args, int from_tty)
1921 {
1922   if (args == NULL)
1923     {
1924       if (query (_("Delete all auto-display expressions? ")))
1925 	clear_displays ();
1926       dont_repeat ();
1927       return;
1928     }
1929 
1930   map_display_numbers (args, do_delete_display, NULL);
1931   dont_repeat ();
1932 }
1933 
1934 /* Display a single auto-display.
1935    Do nothing if the display cannot be printed in the current context,
1936    or if the display is disabled.  */
1937 
1938 static void
1939 do_one_display (struct display *d)
1940 {
1941   struct cleanup *old_chain;
1942   int within_current_scope;
1943 
1944   if (d->enabled_p == 0)
1945     return;
1946 
1947   /* The expression carries the architecture that was used at parse time.
1948      This is a problem if the expression depends on architecture features
1949      (e.g. register numbers), and the current architecture is now different.
1950      For example, a display statement like "display/i $pc" is expected to
1951      display the PC register of the current architecture, not the arch at
1952      the time the display command was given.  Therefore, we re-parse the
1953      expression if the current architecture has changed.  */
1954   if (d->exp != NULL && d->exp->gdbarch != get_current_arch ())
1955     {
1956       xfree (d->exp);
1957       d->exp = NULL;
1958       d->block = NULL;
1959     }
1960 
1961   if (d->exp == NULL)
1962     {
1963 
1964       TRY
1965 	{
1966 	  innermost_block = NULL;
1967 	  d->exp = parse_expression (d->exp_string);
1968 	  d->block = innermost_block;
1969 	}
1970       CATCH (ex, RETURN_MASK_ALL)
1971 	{
1972 	  /* Can't re-parse the expression.  Disable this display item.  */
1973 	  d->enabled_p = 0;
1974 	  warning (_("Unable to display \"%s\": %s"),
1975 		   d->exp_string, ex.message);
1976 	  return;
1977 	}
1978       END_CATCH
1979     }
1980 
1981   if (d->block)
1982     {
1983       if (d->pspace == current_program_space)
1984 	within_current_scope = contained_in (get_selected_block (0), d->block);
1985       else
1986 	within_current_scope = 0;
1987     }
1988   else
1989     within_current_scope = 1;
1990   if (!within_current_scope)
1991     return;
1992 
1993   old_chain = make_cleanup_restore_integer (&current_display_number);
1994   current_display_number = d->number;
1995 
1996   annotate_display_begin ();
1997   printf_filtered ("%d", d->number);
1998   annotate_display_number_end ();
1999   printf_filtered (": ");
2000   if (d->format.size)
2001     {
2002 
2003       annotate_display_format ();
2004 
2005       printf_filtered ("x/");
2006       if (d->format.count != 1)
2007 	printf_filtered ("%d", d->format.count);
2008       printf_filtered ("%c", d->format.format);
2009       if (d->format.format != 'i' && d->format.format != 's')
2010 	printf_filtered ("%c", d->format.size);
2011       printf_filtered (" ");
2012 
2013       annotate_display_expression ();
2014 
2015       puts_filtered (d->exp_string);
2016       annotate_display_expression_end ();
2017 
2018       if (d->format.count != 1 || d->format.format == 'i')
2019 	printf_filtered ("\n");
2020       else
2021 	printf_filtered ("  ");
2022 
2023       annotate_display_value ();
2024 
2025       TRY
2026         {
2027 	  struct value *val;
2028 	  CORE_ADDR addr;
2029 
2030 	  val = evaluate_expression (d->exp);
2031 	  addr = value_as_address (val);
2032 	  if (d->format.format == 'i')
2033 	    addr = gdbarch_addr_bits_remove (d->exp->gdbarch, addr);
2034 	  do_examine (d->format, d->exp->gdbarch, addr);
2035 	}
2036       CATCH (ex, RETURN_MASK_ERROR)
2037 	{
2038 	  fprintf_filtered (gdb_stdout, _("<error: %s>\n"), ex.message);
2039 	}
2040       END_CATCH
2041     }
2042   else
2043     {
2044       struct value_print_options opts;
2045 
2046       annotate_display_format ();
2047 
2048       if (d->format.format)
2049 	printf_filtered ("/%c ", d->format.format);
2050 
2051       annotate_display_expression ();
2052 
2053       puts_filtered (d->exp_string);
2054       annotate_display_expression_end ();
2055 
2056       printf_filtered (" = ");
2057 
2058       annotate_display_expression ();
2059 
2060       get_formatted_print_options (&opts, d->format.format);
2061       opts.raw = d->format.raw;
2062 
2063       TRY
2064         {
2065 	  struct value *val;
2066 
2067 	  val = evaluate_expression (d->exp);
2068 	  print_formatted (val, d->format.size, &opts, gdb_stdout);
2069 	}
2070       CATCH (ex, RETURN_MASK_ERROR)
2071 	{
2072 	  fprintf_filtered (gdb_stdout, _("<error: %s>"), ex.message);
2073 	}
2074       END_CATCH
2075 
2076       printf_filtered ("\n");
2077     }
2078 
2079   annotate_display_end ();
2080 
2081   gdb_flush (gdb_stdout);
2082   do_cleanups (old_chain);
2083 }
2084 
2085 /* Display all of the values on the auto-display chain which can be
2086    evaluated in the current scope.  */
2087 
2088 void
2089 do_displays (void)
2090 {
2091   struct display *d;
2092 
2093   for (d = display_chain; d; d = d->next)
2094     do_one_display (d);
2095 }
2096 
2097 /* Delete the auto-display which we were in the process of displaying.
2098    This is done when there is an error or a signal.  */
2099 
2100 void
2101 disable_display (int num)
2102 {
2103   struct display *d;
2104 
2105   for (d = display_chain; d; d = d->next)
2106     if (d->number == num)
2107       {
2108 	d->enabled_p = 0;
2109 	return;
2110       }
2111   printf_unfiltered (_("No display number %d.\n"), num);
2112 }
2113 
2114 void
2115 disable_current_display (void)
2116 {
2117   if (current_display_number >= 0)
2118     {
2119       disable_display (current_display_number);
2120       fprintf_unfiltered (gdb_stderr,
2121 			  _("Disabling display %d to "
2122 			    "avoid infinite recursion.\n"),
2123 			  current_display_number);
2124     }
2125   current_display_number = -1;
2126 }
2127 
2128 static void
2129 display_info (char *ignore, int from_tty)
2130 {
2131   struct display *d;
2132 
2133   if (!display_chain)
2134     printf_unfiltered (_("There are no auto-display expressions now.\n"));
2135   else
2136     printf_filtered (_("Auto-display expressions now in effect:\n\
2137 Num Enb Expression\n"));
2138 
2139   for (d = display_chain; d; d = d->next)
2140     {
2141       printf_filtered ("%d:   %c  ", d->number, "ny"[(int) d->enabled_p]);
2142       if (d->format.size)
2143 	printf_filtered ("/%d%c%c ", d->format.count, d->format.size,
2144 			 d->format.format);
2145       else if (d->format.format)
2146 	printf_filtered ("/%c ", d->format.format);
2147       puts_filtered (d->exp_string);
2148       if (d->block && !contained_in (get_selected_block (0), d->block))
2149 	printf_filtered (_(" (cannot be evaluated in the current context)"));
2150       printf_filtered ("\n");
2151       gdb_flush (gdb_stdout);
2152     }
2153 }
2154 
2155 /* Callback fo map_display_numbers, that enables or disables the
2156    passed in display D.  */
2157 
2158 static void
2159 do_enable_disable_display (struct display *d, void *data)
2160 {
2161   d->enabled_p = *(int *) data;
2162 }
2163 
2164 /* Implamentation of both the "disable display" and "enable display"
2165    commands.  ENABLE decides what to do.  */
2166 
2167 static void
2168 enable_disable_display_command (char *args, int from_tty, int enable)
2169 {
2170   if (args == NULL)
2171     {
2172       struct display *d;
2173 
2174       ALL_DISPLAYS (d)
2175 	d->enabled_p = enable;
2176       return;
2177     }
2178 
2179   map_display_numbers (args, do_enable_disable_display, &enable);
2180 }
2181 
2182 /* The "enable display" command.  */
2183 
2184 static void
2185 enable_display_command (char *args, int from_tty)
2186 {
2187   enable_disable_display_command (args, from_tty, 1);
2188 }
2189 
2190 /* The "disable display" command.  */
2191 
2192 static void
2193 disable_display_command (char *args, int from_tty)
2194 {
2195   enable_disable_display_command (args, from_tty, 0);
2196 }
2197 
2198 /* display_chain items point to blocks and expressions.  Some expressions in
2199    turn may point to symbols.
2200    Both symbols and blocks are obstack_alloc'd on objfile_stack, and are
2201    obstack_free'd when a shared library is unloaded.
2202    Clear pointers that are about to become dangling.
2203    Both .exp and .block fields will be restored next time we need to display
2204    an item by re-parsing .exp_string field in the new execution context.  */
2205 
2206 static void
2207 clear_dangling_display_expressions (struct objfile *objfile)
2208 {
2209   struct display *d;
2210   struct program_space *pspace;
2211 
2212   /* With no symbol file we cannot have a block or expression from it.  */
2213   if (objfile == NULL)
2214     return;
2215   pspace = objfile->pspace;
2216   if (objfile->separate_debug_objfile_backlink)
2217     {
2218       objfile = objfile->separate_debug_objfile_backlink;
2219       gdb_assert (objfile->pspace == pspace);
2220     }
2221 
2222   for (d = display_chain; d != NULL; d = d->next)
2223     {
2224       if (d->pspace != pspace)
2225 	continue;
2226 
2227       if (lookup_objfile_from_block (d->block) == objfile
2228 	  || (d->exp && exp_uses_objfile (d->exp, objfile)))
2229       {
2230 	xfree (d->exp);
2231 	d->exp = NULL;
2232 	d->block = NULL;
2233       }
2234     }
2235 }
2236 
2237 
2238 /* Print the value in stack frame FRAME of a variable specified by a
2239    struct symbol.  NAME is the name to print; if NULL then VAR's print
2240    name will be used.  STREAM is the ui_file on which to print the
2241    value.  INDENT specifies the number of indent levels to print
2242    before printing the variable name.
2243 
2244    This function invalidates FRAME.  */
2245 
2246 void
2247 print_variable_and_value (const char *name, struct symbol *var,
2248 			  struct frame_info *frame,
2249 			  struct ui_file *stream, int indent)
2250 {
2251 
2252   if (!name)
2253     name = SYMBOL_PRINT_NAME (var);
2254 
2255   fprintf_filtered (stream, "%s%s = ", n_spaces (2 * indent), name);
2256   TRY
2257     {
2258       struct value *val;
2259       struct value_print_options opts;
2260 
2261       /* READ_VAR_VALUE needs a block in order to deal with non-local
2262 	 references (i.e. to handle nested functions).  In this context, we
2263 	 print variables that are local to this frame, so we can avoid passing
2264 	 a block to it.  */
2265       val = read_var_value (var, NULL, frame);
2266       get_user_print_options (&opts);
2267       opts.deref_ref = 1;
2268       common_val_print (val, stream, indent, &opts, current_language);
2269 
2270       /* common_val_print invalidates FRAME when a pretty printer calls inferior
2271 	 function.  */
2272       frame = NULL;
2273     }
2274   CATCH (except, RETURN_MASK_ERROR)
2275     {
2276       fprintf_filtered(stream, "<error reading variable %s (%s)>", name,
2277 		       except.message);
2278     }
2279   END_CATCH
2280 
2281   fprintf_filtered (stream, "\n");
2282 }
2283 
2284 /* Subroutine of ui_printf to simplify it.
2285    Print VALUE to STREAM using FORMAT.
2286    VALUE is a C-style string on the target.  */
2287 
2288 static void
2289 printf_c_string (struct ui_file *stream, const char *format,
2290 		 struct value *value)
2291 {
2292   gdb_byte *str;
2293   CORE_ADDR tem;
2294   int j;
2295 
2296   tem = value_as_address (value);
2297 
2298   /* This is a %s argument.  Find the length of the string.  */
2299   for (j = 0;; j++)
2300     {
2301       gdb_byte c;
2302 
2303       QUIT;
2304       read_memory (tem + j, &c, 1);
2305       if (c == 0)
2306 	break;
2307     }
2308 
2309   /* Copy the string contents into a string inside GDB.  */
2310   str = (gdb_byte *) alloca (j + 1);
2311   if (j != 0)
2312     read_memory (tem, str, j);
2313   str[j] = 0;
2314 
2315   fprintf_filtered (stream, format, (char *) str);
2316 }
2317 
2318 /* Subroutine of ui_printf to simplify it.
2319    Print VALUE to STREAM using FORMAT.
2320    VALUE is a wide C-style string on the target.  */
2321 
2322 static void
2323 printf_wide_c_string (struct ui_file *stream, const char *format,
2324 		      struct value *value)
2325 {
2326   gdb_byte *str;
2327   CORE_ADDR tem;
2328   int j;
2329   struct gdbarch *gdbarch = get_type_arch (value_type (value));
2330   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
2331   struct type *wctype = lookup_typename (current_language, gdbarch,
2332 					 "wchar_t", NULL, 0);
2333   int wcwidth = TYPE_LENGTH (wctype);
2334   gdb_byte *buf = (gdb_byte *) alloca (wcwidth);
2335   struct obstack output;
2336   struct cleanup *inner_cleanup;
2337 
2338   tem = value_as_address (value);
2339 
2340   /* This is a %s argument.  Find the length of the string.  */
2341   for (j = 0;; j += wcwidth)
2342     {
2343       QUIT;
2344       read_memory (tem + j, buf, wcwidth);
2345       if (extract_unsigned_integer (buf, wcwidth, byte_order) == 0)
2346 	break;
2347     }
2348 
2349   /* Copy the string contents into a string inside GDB.  */
2350   str = (gdb_byte *) alloca (j + wcwidth);
2351   if (j != 0)
2352     read_memory (tem, str, j);
2353   memset (&str[j], 0, wcwidth);
2354 
2355   obstack_init (&output);
2356   inner_cleanup = make_cleanup_obstack_free (&output);
2357 
2358   convert_between_encodings (target_wide_charset (gdbarch),
2359 			     host_charset (),
2360 			     str, j, wcwidth,
2361 			     &output, translit_char);
2362   obstack_grow_str0 (&output, "");
2363 
2364   fprintf_filtered (stream, format, obstack_base (&output));
2365   do_cleanups (inner_cleanup);
2366 }
2367 
2368 /* Subroutine of ui_printf to simplify it.
2369    Print VALUE, a decimal floating point value, to STREAM using FORMAT.  */
2370 
2371 static void
2372 printf_decfloat (struct ui_file *stream, const char *format,
2373 		 struct value *value)
2374 {
2375   const gdb_byte *param_ptr = value_contents (value);
2376 
2377 #if defined (PRINTF_HAS_DECFLOAT)
2378   /* If we have native support for Decimal floating
2379      printing, handle it here.  */
2380   fprintf_filtered (stream, format, param_ptr);
2381 #else
2382   /* As a workaround until vasprintf has native support for DFP
2383      we convert the DFP values to string and print them using
2384      the %s format specifier.  */
2385   const char *p;
2386 
2387   /* Parameter data.  */
2388   struct type *param_type = value_type (value);
2389   struct gdbarch *gdbarch = get_type_arch (param_type);
2390   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
2391 
2392   /* DFP output data.  */
2393   struct value *dfp_value = NULL;
2394   gdb_byte *dfp_ptr;
2395   int dfp_len = 16;
2396   gdb_byte dec[16];
2397   struct type *dfp_type = NULL;
2398   char decstr[MAX_DECIMAL_STRING];
2399 
2400   /* Points to the end of the string so that we can go back
2401      and check for DFP length modifiers.  */
2402   p = format + strlen (format);
2403 
2404   /* Look for the float/double format specifier.  */
2405   while (*p != 'f' && *p != 'e' && *p != 'E'
2406 	 && *p != 'g' && *p != 'G')
2407     p--;
2408 
2409   /* Search for the '%' char and extract the size and type of
2410      the output decimal value based on its modifiers
2411      (%Hf, %Df, %DDf).  */
2412   while (*--p != '%')
2413     {
2414       if (*p == 'H')
2415 	{
2416 	  dfp_len = 4;
2417 	  dfp_type = builtin_type (gdbarch)->builtin_decfloat;
2418 	}
2419       else if (*p == 'D' && *(p - 1) == 'D')
2420 	{
2421 	  dfp_len = 16;
2422 	  dfp_type = builtin_type (gdbarch)->builtin_declong;
2423 	  p--;
2424 	}
2425       else
2426 	{
2427 	  dfp_len = 8;
2428 	  dfp_type = builtin_type (gdbarch)->builtin_decdouble;
2429 	}
2430     }
2431 
2432   /* Conversion between different DFP types.  */
2433   if (TYPE_CODE (param_type) == TYPE_CODE_DECFLOAT)
2434     decimal_convert (param_ptr, TYPE_LENGTH (param_type),
2435 		     byte_order, dec, dfp_len, byte_order);
2436   else
2437     /* If this is a non-trivial conversion, just output 0.
2438        A correct converted value can be displayed by explicitly
2439        casting to a DFP type.  */
2440     decimal_from_string (dec, dfp_len, byte_order, "0");
2441 
2442   dfp_value = value_from_decfloat (dfp_type, dec);
2443 
2444   dfp_ptr = (gdb_byte *) value_contents (dfp_value);
2445 
2446   decimal_to_string (dfp_ptr, dfp_len, byte_order, decstr);
2447 
2448   /* Print the DFP value.  */
2449   fprintf_filtered (stream, "%s", decstr);
2450 #endif
2451 }
2452 
2453 /* Subroutine of ui_printf to simplify it.
2454    Print VALUE, a target pointer, to STREAM using FORMAT.  */
2455 
2456 static void
2457 printf_pointer (struct ui_file *stream, const char *format,
2458 		struct value *value)
2459 {
2460   /* We avoid the host's %p because pointers are too
2461      likely to be the wrong size.  The only interesting
2462      modifier for %p is a width; extract that, and then
2463      handle %p as glibc would: %#x or a literal "(nil)".  */
2464 
2465   const char *p;
2466   char *fmt, *fmt_p;
2467 #ifdef PRINTF_HAS_LONG_LONG
2468   long long val = value_as_long (value);
2469 #else
2470   long val = value_as_long (value);
2471 #endif
2472 
2473   fmt = (char *) alloca (strlen (format) + 5);
2474 
2475   /* Copy up to the leading %.  */
2476   p = format;
2477   fmt_p = fmt;
2478   while (*p)
2479     {
2480       int is_percent = (*p == '%');
2481 
2482       *fmt_p++ = *p++;
2483       if (is_percent)
2484 	{
2485 	  if (*p == '%')
2486 	    *fmt_p++ = *p++;
2487 	  else
2488 	    break;
2489 	}
2490     }
2491 
2492   if (val != 0)
2493     *fmt_p++ = '#';
2494 
2495   /* Copy any width.  */
2496   while (*p >= '0' && *p < '9')
2497     *fmt_p++ = *p++;
2498 
2499   gdb_assert (*p == 'p' && *(p + 1) == '\0');
2500   if (val != 0)
2501     {
2502 #ifdef PRINTF_HAS_LONG_LONG
2503       *fmt_p++ = 'l';
2504 #endif
2505       *fmt_p++ = 'l';
2506       *fmt_p++ = 'x';
2507       *fmt_p++ = '\0';
2508       fprintf_filtered (stream, fmt, val);
2509     }
2510   else
2511     {
2512       *fmt_p++ = 's';
2513       *fmt_p++ = '\0';
2514       fprintf_filtered (stream, fmt, "(nil)");
2515     }
2516 }
2517 
2518 /* printf "printf format string" ARG to STREAM.  */
2519 
2520 static void
2521 ui_printf (const char *arg, struct ui_file *stream)
2522 {
2523   struct format_piece *fpieces;
2524   const char *s = arg;
2525   struct value **val_args;
2526   int allocated_args = 20;
2527   struct cleanup *old_cleanups;
2528 
2529   val_args = XNEWVEC (struct value *, allocated_args);
2530   old_cleanups = make_cleanup (free_current_contents, &val_args);
2531 
2532   if (s == 0)
2533     error_no_arg (_("format-control string and values to print"));
2534 
2535   s = skip_spaces_const (s);
2536 
2537   /* A format string should follow, enveloped in double quotes.  */
2538   if (*s++ != '"')
2539     error (_("Bad format string, missing '\"'."));
2540 
2541   fpieces = parse_format_string (&s);
2542 
2543   make_cleanup (free_format_pieces_cleanup, &fpieces);
2544 
2545   if (*s++ != '"')
2546     error (_("Bad format string, non-terminated '\"'."));
2547 
2548   s = skip_spaces_const (s);
2549 
2550   if (*s != ',' && *s != 0)
2551     error (_("Invalid argument syntax"));
2552 
2553   if (*s == ',')
2554     s++;
2555   s = skip_spaces_const (s);
2556 
2557   {
2558     int nargs = 0;
2559     int nargs_wanted;
2560     int i, fr;
2561     char *current_substring;
2562 
2563     nargs_wanted = 0;
2564     for (fr = 0; fpieces[fr].string != NULL; fr++)
2565       if (fpieces[fr].argclass != literal_piece)
2566 	++nargs_wanted;
2567 
2568     /* Now, parse all arguments and evaluate them.
2569        Store the VALUEs in VAL_ARGS.  */
2570 
2571     while (*s != '\0')
2572       {
2573 	const char *s1;
2574 
2575 	if (nargs == allocated_args)
2576 	  val_args = (struct value **) xrealloc ((char *) val_args,
2577 						 (allocated_args *= 2)
2578 						 * sizeof (struct value *));
2579 	s1 = s;
2580 	val_args[nargs] = parse_to_comma_and_eval (&s1);
2581 
2582 	nargs++;
2583 	s = s1;
2584 	if (*s == ',')
2585 	  s++;
2586       }
2587 
2588     if (nargs != nargs_wanted)
2589       error (_("Wrong number of arguments for specified format-string"));
2590 
2591     /* Now actually print them.  */
2592     i = 0;
2593     for (fr = 0; fpieces[fr].string != NULL; fr++)
2594       {
2595 	current_substring = fpieces[fr].string;
2596 	switch (fpieces[fr].argclass)
2597 	  {
2598 	  case string_arg:
2599 	    printf_c_string (stream, current_substring, val_args[i]);
2600 	    break;
2601 	  case wide_string_arg:
2602 	    printf_wide_c_string (stream, current_substring, val_args[i]);
2603 	    break;
2604 	  case wide_char_arg:
2605 	    {
2606 	      struct gdbarch *gdbarch
2607 		= get_type_arch (value_type (val_args[i]));
2608 	      struct type *wctype = lookup_typename (current_language, gdbarch,
2609 						     "wchar_t", NULL, 0);
2610 	      struct type *valtype;
2611 	      struct obstack output;
2612 	      struct cleanup *inner_cleanup;
2613 	      const gdb_byte *bytes;
2614 
2615 	      valtype = value_type (val_args[i]);
2616 	      if (TYPE_LENGTH (valtype) != TYPE_LENGTH (wctype)
2617 		  || TYPE_CODE (valtype) != TYPE_CODE_INT)
2618 		error (_("expected wchar_t argument for %%lc"));
2619 
2620 	      bytes = value_contents (val_args[i]);
2621 
2622 	      obstack_init (&output);
2623 	      inner_cleanup = make_cleanup_obstack_free (&output);
2624 
2625 	      convert_between_encodings (target_wide_charset (gdbarch),
2626 					 host_charset (),
2627 					 bytes, TYPE_LENGTH (valtype),
2628 					 TYPE_LENGTH (valtype),
2629 					 &output, translit_char);
2630 	      obstack_grow_str0 (&output, "");
2631 
2632 	      fprintf_filtered (stream, current_substring,
2633                                 obstack_base (&output));
2634 	      do_cleanups (inner_cleanup);
2635 	    }
2636 	    break;
2637 	  case double_arg:
2638 	    {
2639 	      struct type *type = value_type (val_args[i]);
2640 	      DOUBLEST val;
2641 	      int inv;
2642 
2643 	      /* If format string wants a float, unchecked-convert the value
2644 		 to floating point of the same size.  */
2645 	      type = float_type_from_length (type);
2646 	      val = unpack_double (type, value_contents (val_args[i]), &inv);
2647 	      if (inv)
2648 		error (_("Invalid floating value found in program."));
2649 
2650               fprintf_filtered (stream, current_substring, (double) val);
2651 	      break;
2652 	    }
2653 	  case long_double_arg:
2654 #ifdef HAVE_LONG_DOUBLE
2655 	    {
2656 	      struct type *type = value_type (val_args[i]);
2657 	      DOUBLEST val;
2658 	      int inv;
2659 
2660 	      /* If format string wants a float, unchecked-convert the value
2661 		 to floating point of the same size.  */
2662 	      type = float_type_from_length (type);
2663 	      val = unpack_double (type, value_contents (val_args[i]), &inv);
2664 	      if (inv)
2665 		error (_("Invalid floating value found in program."));
2666 
2667 	      fprintf_filtered (stream, current_substring,
2668                                 (long double) val);
2669 	      break;
2670 	    }
2671 #else
2672 	    error (_("long double not supported in printf"));
2673 #endif
2674 	  case long_long_arg:
2675 #ifdef PRINTF_HAS_LONG_LONG
2676 	    {
2677 	      long long val = value_as_long (val_args[i]);
2678 
2679               fprintf_filtered (stream, current_substring, val);
2680 	      break;
2681 	    }
2682 #else
2683 	    error (_("long long not supported in printf"));
2684 #endif
2685 	  case int_arg:
2686 	    {
2687 	      int val = value_as_long (val_args[i]);
2688 
2689               fprintf_filtered (stream, current_substring, val);
2690 	      break;
2691 	    }
2692 	  case long_arg:
2693 	    {
2694 	      long val = value_as_long (val_args[i]);
2695 
2696               fprintf_filtered (stream, current_substring, val);
2697 	      break;
2698 	    }
2699 	  /* Handles decimal floating values.  */
2700 	  case decfloat_arg:
2701 	    printf_decfloat (stream, current_substring, val_args[i]);
2702 	    break;
2703 	  case ptr_arg:
2704 	    printf_pointer (stream, current_substring, val_args[i]);
2705 	    break;
2706 	  case literal_piece:
2707 	    /* Print a portion of the format string that has no
2708 	       directives.  Note that this will not include any
2709 	       ordinary %-specs, but it might include "%%".  That is
2710 	       why we use printf_filtered and not puts_filtered here.
2711 	       Also, we pass a dummy argument because some platforms
2712 	       have modified GCC to include -Wformat-security by
2713 	       default, which will warn here if there is no
2714 	       argument.  */
2715 	    fprintf_filtered (stream, current_substring, 0);
2716 	    break;
2717 	  default:
2718 	    internal_error (__FILE__, __LINE__,
2719 			    _("failed internal consistency check"));
2720 	  }
2721 	/* Maybe advance to the next argument.  */
2722 	if (fpieces[fr].argclass != literal_piece)
2723 	  ++i;
2724       }
2725   }
2726   do_cleanups (old_cleanups);
2727 }
2728 
2729 /* Implement the "printf" command.  */
2730 
2731 static void
2732 printf_command (char *arg, int from_tty)
2733 {
2734   ui_printf (arg, gdb_stdout);
2735   gdb_flush (gdb_stdout);
2736 }
2737 
2738 /* Implement the "eval" command.  */
2739 
2740 static void
2741 eval_command (char *arg, int from_tty)
2742 {
2743   struct ui_file *ui_out = mem_fileopen ();
2744   struct cleanup *cleanups = make_cleanup_ui_file_delete (ui_out);
2745   char *expanded;
2746 
2747   ui_printf (arg, ui_out);
2748 
2749   expanded = ui_file_xstrdup (ui_out, NULL);
2750   make_cleanup (xfree, expanded);
2751 
2752   execute_command (expanded, from_tty);
2753 
2754   do_cleanups (cleanups);
2755 }
2756 
2757 void
2758 _initialize_printcmd (void)
2759 {
2760   struct cmd_list_element *c;
2761 
2762   current_display_number = -1;
2763 
2764   observer_attach_free_objfile (clear_dangling_display_expressions);
2765 
2766   add_info ("address", address_info,
2767 	    _("Describe where symbol SYM is stored."));
2768 
2769   add_info ("symbol", sym_info, _("\
2770 Describe what symbol is at location ADDR.\n\
2771 Only for symbols with fixed locations (global or static scope)."));
2772 
2773   add_com ("x", class_vars, x_command, _("\
2774 Examine memory: x/FMT ADDRESS.\n\
2775 ADDRESS is an expression for the memory address to examine.\n\
2776 FMT is a repeat count followed by a format letter and a size letter.\n\
2777 Format letters are o(octal), x(hex), d(decimal), u(unsigned decimal),\n\
2778   t(binary), f(float), a(address), i(instruction), c(char), s(string)\n\
2779   and z(hex, zero padded on the left).\n\
2780 Size letters are b(byte), h(halfword), w(word), g(giant, 8 bytes).\n\
2781 The specified number of objects of the specified size are printed\n\
2782 according to the format.  If a negative number is specified, memory is\n\
2783 examined backward from the address.\n\n\
2784 Defaults for format and size letters are those previously used.\n\
2785 Default count is 1.  Default address is following last thing printed\n\
2786 with this command or \"print\"."));
2787 
2788 #if 0
2789   add_com ("whereis", class_vars, whereis_command,
2790 	   _("Print line number and file of definition of variable."));
2791 #endif
2792 
2793   add_info ("display", display_info, _("\
2794 Expressions to display when program stops, with code numbers."));
2795 
2796   add_cmd ("undisplay", class_vars, undisplay_command, _("\
2797 Cancel some expressions to be displayed when program stops.\n\
2798 Arguments are the code numbers of the expressions to stop displaying.\n\
2799 No argument means cancel all automatic-display expressions.\n\
2800 \"delete display\" has the same effect as this command.\n\
2801 Do \"info display\" to see current list of code numbers."),
2802 	   &cmdlist);
2803 
2804   add_com ("display", class_vars, display_command, _("\
2805 Print value of expression EXP each time the program stops.\n\
2806 /FMT may be used before EXP as in the \"print\" command.\n\
2807 /FMT \"i\" or \"s\" or including a size-letter is allowed,\n\
2808 as in the \"x\" command, and then EXP is used to get the address to examine\n\
2809 and examining is done as in the \"x\" command.\n\n\
2810 With no argument, display all currently requested auto-display expressions.\n\
2811 Use \"undisplay\" to cancel display requests previously made."));
2812 
2813   add_cmd ("display", class_vars, enable_display_command, _("\
2814 Enable some expressions to be displayed when program stops.\n\
2815 Arguments are the code numbers of the expressions to resume displaying.\n\
2816 No argument means enable all automatic-display expressions.\n\
2817 Do \"info display\" to see current list of code numbers."), &enablelist);
2818 
2819   add_cmd ("display", class_vars, disable_display_command, _("\
2820 Disable some expressions to be displayed when program stops.\n\
2821 Arguments are the code numbers of the expressions to stop displaying.\n\
2822 No argument means disable all automatic-display expressions.\n\
2823 Do \"info display\" to see current list of code numbers."), &disablelist);
2824 
2825   add_cmd ("display", class_vars, undisplay_command, _("\
2826 Cancel some expressions to be displayed when program stops.\n\
2827 Arguments are the code numbers of the expressions to stop displaying.\n\
2828 No argument means cancel all automatic-display expressions.\n\
2829 Do \"info display\" to see current list of code numbers."), &deletelist);
2830 
2831   add_com ("printf", class_vars, printf_command, _("\
2832 printf \"printf format string\", arg1, arg2, arg3, ..., argn\n\
2833 This is useful for formatted output in user-defined commands."));
2834 
2835   add_com ("output", class_vars, output_command, _("\
2836 Like \"print\" but don't put in value history and don't print newline.\n\
2837 This is useful in user-defined commands."));
2838 
2839   add_prefix_cmd ("set", class_vars, set_command, _("\
2840 Evaluate expression EXP and assign result to variable VAR, using assignment\n\
2841 syntax appropriate for the current language (VAR = EXP or VAR := EXP for\n\
2842 example).  VAR may be a debugger \"convenience\" variable (names starting\n\
2843 with $), a register (a few standard names starting with $), or an actual\n\
2844 variable in the program being debugged.  EXP is any valid expression.\n\
2845 Use \"set variable\" for variables with names identical to set subcommands.\n\
2846 \n\
2847 With a subcommand, this command modifies parts of the gdb environment.\n\
2848 You can see these environment settings with the \"show\" command."),
2849 		  &setlist, "set ", 1, &cmdlist);
2850   if (dbx_commands)
2851     add_com ("assign", class_vars, set_command, _("\
2852 Evaluate expression EXP and assign result to variable VAR, using assignment\n\
2853 syntax appropriate for the current language (VAR = EXP or VAR := EXP for\n\
2854 example).  VAR may be a debugger \"convenience\" variable (names starting\n\
2855 with $), a register (a few standard names starting with $), or an actual\n\
2856 variable in the program being debugged.  EXP is any valid expression.\n\
2857 Use \"set variable\" for variables with names identical to set subcommands.\n\
2858 \nWith a subcommand, this command modifies parts of the gdb environment.\n\
2859 You can see these environment settings with the \"show\" command."));
2860 
2861   /* "call" is the same as "set", but handy for dbx users to call fns.  */
2862   c = add_com ("call", class_vars, call_command, _("\
2863 Call a function in the program.\n\
2864 The argument is the function name and arguments, in the notation of the\n\
2865 current working language.  The result is printed and saved in the value\n\
2866 history, if it is not void."));
2867   set_cmd_completer (c, expression_completer);
2868 
2869   add_cmd ("variable", class_vars, set_command, _("\
2870 Evaluate expression EXP and assign result to variable VAR, using assignment\n\
2871 syntax appropriate for the current language (VAR = EXP or VAR := EXP for\n\
2872 example).  VAR may be a debugger \"convenience\" variable (names starting\n\
2873 with $), a register (a few standard names starting with $), or an actual\n\
2874 variable in the program being debugged.  EXP is any valid expression.\n\
2875 This may usually be abbreviated to simply \"set\"."),
2876 	   &setlist);
2877 
2878   c = add_com ("print", class_vars, print_command, _("\
2879 Print value of expression EXP.\n\
2880 Variables accessible are those of the lexical environment of the selected\n\
2881 stack frame, plus all those whose scope is global or an entire file.\n\
2882 \n\
2883 $NUM gets previous value number NUM.  $ and $$ are the last two values.\n\
2884 $$NUM refers to NUM'th value back from the last one.\n\
2885 Names starting with $ refer to registers (with the values they would have\n\
2886 if the program were to return to the stack frame now selected, restoring\n\
2887 all registers saved by frames farther in) or else to debugger\n\
2888 \"convenience\" variables (any such name not a known register).\n\
2889 Use assignment expressions to give values to convenience variables.\n\
2890 \n\
2891 {TYPE}ADREXP refers to a datum of data type TYPE, located at address ADREXP.\n\
2892 @ is a binary operator for treating consecutive data objects\n\
2893 anywhere in memory as an array.  FOO@NUM gives an array whose first\n\
2894 element is FOO, whose second element is stored in the space following\n\
2895 where FOO is stored, etc.  FOO must be an expression whose value\n\
2896 resides in memory.\n\
2897 \n\
2898 EXP may be preceded with /FMT, where FMT is a format letter\n\
2899 but no count or size letter (see \"x\" command)."));
2900   set_cmd_completer (c, expression_completer);
2901   add_com_alias ("p", "print", class_vars, 1);
2902   add_com_alias ("inspect", "print", class_vars, 1);
2903 
2904   add_setshow_uinteger_cmd ("max-symbolic-offset", no_class,
2905 			    &max_symbolic_offset, _("\
2906 Set the largest offset that will be printed in <symbol+1234> form."), _("\
2907 Show the largest offset that will be printed in <symbol+1234> form."), _("\
2908 Tell GDB to only display the symbolic form of an address if the\n\
2909 offset between the closest earlier symbol and the address is less than\n\
2910 the specified maximum offset.  The default is \"unlimited\", which tells GDB\n\
2911 to always print the symbolic form of an address if any symbol precedes\n\
2912 it.  Zero is equivalent to \"unlimited\"."),
2913 			    NULL,
2914 			    show_max_symbolic_offset,
2915 			    &setprintlist, &showprintlist);
2916   add_setshow_boolean_cmd ("symbol-filename", no_class,
2917 			   &print_symbol_filename, _("\
2918 Set printing of source filename and line number with <symbol>."), _("\
2919 Show printing of source filename and line number with <symbol>."), NULL,
2920 			   NULL,
2921 			   show_print_symbol_filename,
2922 			   &setprintlist, &showprintlist);
2923 
2924   add_com ("eval", no_class, eval_command, _("\
2925 Convert \"printf format string\", arg1, arg2, arg3, ..., argn to\n\
2926 a command line, and call it."));
2927 }
2928