xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/printcmd.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /* Print values for GNU debugger GDB.
2 
3    Copyright (C) 1986-2019 Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19 
20 #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 "target-float.h"
42 #include "observable.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 "cli/cli-script.h"
49 #include "cli/cli-style.h"
50 #include "common/format.h"
51 #include "source.h"
52 #include "common/byte-vector.h"
53 
54 /* Last specified output format.  */
55 
56 static char last_format = 0;
57 
58 /* Last specified examination size.  'b', 'h', 'w' or `q'.  */
59 
60 static char last_size = 'w';
61 
62 /* Last specified count for the 'x' command.  */
63 
64 static int last_count;
65 
66 /* Default address to examine next, and associated architecture.  */
67 
68 static struct gdbarch *next_gdbarch;
69 static CORE_ADDR next_address;
70 
71 /* Number of delay instructions following current disassembled insn.  */
72 
73 static int branch_delay_insns;
74 
75 /* Last address examined.  */
76 
77 static CORE_ADDR last_examine_address;
78 
79 /* Contents of last address examined.
80    This is not valid past the end of the `x' command!  */
81 
82 static value_ref_ptr last_examine_value;
83 
84 /* Largest offset between a symbolic value and an address, that will be
85    printed as `0x1234 <symbol+offset>'.  */
86 
87 static unsigned int max_symbolic_offset = UINT_MAX;
88 static void
89 show_max_symbolic_offset (struct ui_file *file, int from_tty,
90 			  struct cmd_list_element *c, const char *value)
91 {
92   fprintf_filtered (file,
93 		    _("The largest offset that will be "
94 		      "printed in <symbol+1234> form is %s.\n"),
95 		    value);
96 }
97 
98 /* Append the source filename and linenumber of the symbol when
99    printing a symbolic value as `<symbol at filename:linenum>' if set.  */
100 static int print_symbol_filename = 0;
101 static void
102 show_print_symbol_filename (struct ui_file *file, int from_tty,
103 			    struct cmd_list_element *c, const char *value)
104 {
105   fprintf_filtered (file, _("Printing of source filename and "
106 			    "line number with <symbol> is %s.\n"),
107 		    value);
108 }
109 
110 /* Number of auto-display expression currently being displayed.
111    So that we can disable it if we get a signal within it.
112    -1 when not doing one.  */
113 
114 static int current_display_number;
115 
116 struct display
117   {
118     /* Chain link to next auto-display item.  */
119     struct display *next;
120 
121     /* The expression as the user typed it.  */
122     char *exp_string;
123 
124     /* Expression to be evaluated and displayed.  */
125     expression_up exp;
126 
127     /* Item number of this auto-display item.  */
128     int number;
129 
130     /* Display format specified.  */
131     struct format_data format;
132 
133     /* Program space associated with `block'.  */
134     struct program_space *pspace;
135 
136     /* Innermost block required by this expression when evaluated.  */
137     const struct block *block;
138 
139     /* Status of this display (enabled or disabled).  */
140     int enabled_p;
141   };
142 
143 /* Chain of expressions whose values should be displayed
144    automatically each time the program stops.  */
145 
146 static struct display *display_chain;
147 
148 static int display_number;
149 
150 /* Walk the following statement or block through all displays.
151    ALL_DISPLAYS_SAFE does so even if the statement deletes the current
152    display.  */
153 
154 #define ALL_DISPLAYS(B)				\
155   for (B = display_chain; B; B = B->next)
156 
157 #define ALL_DISPLAYS_SAFE(B,TMP)		\
158   for (B = display_chain;			\
159        B ? (TMP = B->next, 1): 0;		\
160        B = TMP)
161 
162 /* Prototypes for local functions.  */
163 
164 static void do_one_display (struct display *);
165 
166 
167 /* Decode a format specification.  *STRING_PTR should point to it.
168    OFORMAT and OSIZE are used as defaults for the format and size
169    if none are given in the format specification.
170    If OSIZE is zero, then the size field of the returned value
171    should be set only if a size is explicitly specified by the
172    user.
173    The structure returned describes all the data
174    found in the specification.  In addition, *STRING_PTR is advanced
175    past the specification and past all whitespace following it.  */
176 
177 static struct format_data
178 decode_format (const char **string_ptr, int oformat, int osize)
179 {
180   struct format_data val;
181   const char *p = *string_ptr;
182 
183   val.format = '?';
184   val.size = '?';
185   val.count = 1;
186   val.raw = 0;
187 
188   if (*p == '-')
189     {
190       val.count = -1;
191       p++;
192     }
193   if (*p >= '0' && *p <= '9')
194     val.count *= atoi (p);
195   while (*p >= '0' && *p <= '9')
196     p++;
197 
198   /* Now process size or format letters that follow.  */
199 
200   while (1)
201     {
202       if (*p == 'b' || *p == 'h' || *p == 'w' || *p == 'g')
203 	val.size = *p++;
204       else if (*p == 'r')
205 	{
206 	  val.raw = 1;
207 	  p++;
208 	}
209       else if (*p >= 'a' && *p <= 'z')
210 	val.format = *p++;
211       else
212 	break;
213     }
214 
215   *string_ptr = skip_spaces (p);
216 
217   /* Set defaults for format and size if not specified.  */
218   if (val.format == '?')
219     {
220       if (val.size == '?')
221 	{
222 	  /* Neither has been specified.  */
223 	  val.format = oformat;
224 	  val.size = osize;
225 	}
226       else
227 	/* If a size is specified, any format makes a reasonable
228 	   default except 'i'.  */
229 	val.format = oformat == 'i' ? 'x' : oformat;
230     }
231   else if (val.size == '?')
232     switch (val.format)
233       {
234       case 'a':
235 	/* Pick the appropriate size for an address.  This is deferred
236 	   until do_examine when we know the actual architecture to use.
237 	   A special size value of 'a' is used to indicate this case.  */
238 	val.size = osize ? 'a' : osize;
239 	break;
240       case 'f':
241 	/* Floating point has to be word or giantword.  */
242 	if (osize == 'w' || osize == 'g')
243 	  val.size = osize;
244 	else
245 	  /* Default it to giantword if the last used size is not
246 	     appropriate.  */
247 	  val.size = osize ? 'g' : osize;
248 	break;
249       case 'c':
250 	/* Characters default to one byte.  */
251 	val.size = osize ? 'b' : osize;
252 	break;
253       case 's':
254 	/* Display strings with byte size chars unless explicitly
255 	   specified.  */
256 	val.size = '\0';
257 	break;
258 
259       default:
260 	/* The default is the size most recently specified.  */
261 	val.size = osize;
262       }
263 
264   return val;
265 }
266 
267 /* Print value VAL on stream according to OPTIONS.
268    Do not end with a newline.
269    SIZE is the letter for the size of datum being printed.
270    This is used to pad hex numbers so they line up.  SIZE is 0
271    for print / output and set for examine.  */
272 
273 static void
274 print_formatted (struct value *val, int size,
275 		 const struct value_print_options *options,
276 		 struct ui_file *stream)
277 {
278   struct type *type = check_typedef (value_type (val));
279   int len = TYPE_LENGTH (type);
280 
281   if (VALUE_LVAL (val) == lval_memory)
282     next_address = value_address (val) + len;
283 
284   if (size)
285     {
286       switch (options->format)
287 	{
288 	case 's':
289 	  {
290 	    struct type *elttype = value_type (val);
291 
292 	    next_address = (value_address (val)
293 			    + val_print_string (elttype, NULL,
294 						value_address (val), -1,
295 						stream, options) * len);
296 	  }
297 	  return;
298 
299 	case 'i':
300 	  /* We often wrap here if there are long symbolic names.  */
301 	  wrap_here ("    ");
302 	  next_address = (value_address (val)
303 			  + gdb_print_insn (get_type_arch (type),
304 					    value_address (val), stream,
305 					    &branch_delay_insns));
306 	  return;
307 	}
308     }
309 
310   if (options->format == 0 || options->format == 's'
311       || TYPE_CODE (type) == TYPE_CODE_REF
312       || TYPE_CODE (type) == TYPE_CODE_ARRAY
313       || TYPE_CODE (type) == TYPE_CODE_STRING
314       || TYPE_CODE (type) == TYPE_CODE_STRUCT
315       || TYPE_CODE (type) == TYPE_CODE_UNION
316       || TYPE_CODE (type) == TYPE_CODE_NAMESPACE)
317     value_print (val, stream, options);
318   else
319     /* User specified format, so don't look to the type to tell us
320        what to do.  */
321     val_print_scalar_formatted (type,
322 				value_embedded_offset (val),
323 				val,
324 				options, size, stream);
325 }
326 
327 /* Return builtin floating point type of same length as TYPE.
328    If no such type is found, return TYPE itself.  */
329 static struct type *
330 float_type_from_length (struct type *type)
331 {
332   struct gdbarch *gdbarch = get_type_arch (type);
333   const struct builtin_type *builtin = builtin_type (gdbarch);
334 
335   if (TYPE_LENGTH (type) == TYPE_LENGTH (builtin->builtin_float))
336     type = builtin->builtin_float;
337   else if (TYPE_LENGTH (type) == TYPE_LENGTH (builtin->builtin_double))
338     type = builtin->builtin_double;
339   else if (TYPE_LENGTH (type) == TYPE_LENGTH (builtin->builtin_long_double))
340     type = builtin->builtin_long_double;
341 
342   return type;
343 }
344 
345 /* Print a scalar of data of type TYPE, pointed to in GDB by VALADDR,
346    according to OPTIONS and SIZE on STREAM.  Formats s and i are not
347    supported at this level.  */
348 
349 void
350 print_scalar_formatted (const gdb_byte *valaddr, struct type *type,
351 			const struct value_print_options *options,
352 			int size, struct ui_file *stream)
353 {
354   struct gdbarch *gdbarch = get_type_arch (type);
355   unsigned int len = TYPE_LENGTH (type);
356   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
357 
358   /* String printing should go through val_print_scalar_formatted.  */
359   gdb_assert (options->format != 's');
360 
361   /* If the value is a pointer, and pointers and addresses are not the
362      same, then at this point, the value's length (in target bytes) is
363      gdbarch_addr_bit/TARGET_CHAR_BIT, not TYPE_LENGTH (type).  */
364   if (TYPE_CODE (type) == TYPE_CODE_PTR)
365     len = gdbarch_addr_bit (gdbarch) / TARGET_CHAR_BIT;
366 
367   /* If we are printing it as unsigned, truncate it in case it is actually
368      a negative signed value (e.g. "print/u (short)-1" should print 65535
369      (if shorts are 16 bits) instead of 4294967295).  */
370   if (options->format != 'c'
371       && (options->format != 'd' || TYPE_UNSIGNED (type)))
372     {
373       if (len < TYPE_LENGTH (type) && byte_order == BFD_ENDIAN_BIG)
374 	valaddr += TYPE_LENGTH (type) - len;
375     }
376 
377   if (size != 0 && (options->format == 'x' || options->format == 't'))
378     {
379       /* Truncate to fit.  */
380       unsigned newlen;
381       switch (size)
382 	{
383 	case 'b':
384 	  newlen = 1;
385 	  break;
386 	case 'h':
387 	  newlen = 2;
388 	  break;
389 	case 'w':
390 	  newlen = 4;
391 	  break;
392 	case 'g':
393 	  newlen = 8;
394 	  break;
395 	default:
396 	  error (_("Undefined output size \"%c\"."), size);
397 	}
398       if (newlen < len && byte_order == BFD_ENDIAN_BIG)
399 	valaddr += len - newlen;
400       len = newlen;
401     }
402 
403   /* Historically gdb has printed floats by first casting them to a
404      long, and then printing the long.  PR cli/16242 suggests changing
405      this to using C-style hex float format.  */
406   gdb::byte_vector converted_float_bytes;
407   if (TYPE_CODE (type) == TYPE_CODE_FLT
408       && (options->format == 'o'
409 	  || options->format == 'x'
410 	  || options->format == 't'
411 	  || options->format == 'z'
412 	  || options->format == 'd'
413 	  || options->format == 'u'))
414     {
415       LONGEST val_long = unpack_long (type, valaddr);
416       converted_float_bytes.resize (TYPE_LENGTH (type));
417       store_signed_integer (converted_float_bytes.data (), TYPE_LENGTH (type),
418 			    byte_order, val_long);
419       valaddr = converted_float_bytes.data ();
420     }
421 
422   /* Printing a non-float type as 'f' will interpret the data as if it were
423      of a floating-point type of the same length, if that exists.  Otherwise,
424      the data is printed as integer.  */
425   char format = options->format;
426   if (format == 'f' && TYPE_CODE (type) != TYPE_CODE_FLT)
427     {
428       type = float_type_from_length (type);
429       if (TYPE_CODE (type) != TYPE_CODE_FLT)
430         format = 0;
431     }
432 
433   switch (format)
434     {
435     case 'o':
436       print_octal_chars (stream, valaddr, len, byte_order);
437       break;
438     case 'd':
439       print_decimal_chars (stream, valaddr, len, true, byte_order);
440       break;
441     case 'u':
442       print_decimal_chars (stream, valaddr, len, false, byte_order);
443       break;
444     case 0:
445       if (TYPE_CODE (type) != TYPE_CODE_FLT)
446 	{
447 	  print_decimal_chars (stream, valaddr, len, !TYPE_UNSIGNED (type),
448 			       byte_order);
449 	  break;
450 	}
451       /* FALLTHROUGH */
452     case 'f':
453       print_floating (valaddr, type, stream);
454       break;
455 
456     case 't':
457       print_binary_chars (stream, valaddr, len, byte_order, size > 0);
458       break;
459     case 'x':
460       print_hex_chars (stream, valaddr, len, byte_order, size > 0);
461       break;
462     case 'z':
463       print_hex_chars (stream, valaddr, len, byte_order, true);
464       break;
465     case 'c':
466       {
467 	struct value_print_options opts = *options;
468 
469 	LONGEST val_long = unpack_long (type, valaddr);
470 
471 	opts.format = 0;
472 	if (TYPE_UNSIGNED (type))
473 	  type = builtin_type (gdbarch)->builtin_true_unsigned_char;
474  	else
475 	  type = builtin_type (gdbarch)->builtin_true_char;
476 
477 	value_print (value_from_longest (type, val_long), stream, &opts);
478       }
479       break;
480 
481     case 'a':
482       {
483 	CORE_ADDR addr = unpack_pointer (type, valaddr);
484 
485 	print_address (gdbarch, addr, stream);
486       }
487       break;
488 
489     default:
490       error (_("Undefined output format \"%c\"."), format);
491     }
492 }
493 
494 /* Specify default address for `x' command.
495    The `info lines' command uses this.  */
496 
497 void
498 set_next_address (struct gdbarch *gdbarch, CORE_ADDR addr)
499 {
500   struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
501 
502   next_gdbarch = gdbarch;
503   next_address = addr;
504 
505   /* Make address available to the user as $_.  */
506   set_internalvar (lookup_internalvar ("_"),
507 		   value_from_pointer (ptr_type, addr));
508 }
509 
510 /* Optionally print address ADDR symbolically as <SYMBOL+OFFSET> on STREAM,
511    after LEADIN.  Print nothing if no symbolic name is found nearby.
512    Optionally also print source file and line number, if available.
513    DO_DEMANGLE controls whether to print a symbol in its native "raw" form,
514    or to interpret it as a possible C++ name and convert it back to source
515    form.  However note that DO_DEMANGLE can be overridden by the specific
516    settings of the demangle and asm_demangle variables.  Returns
517    non-zero if anything was printed; zero otherwise.  */
518 
519 int
520 print_address_symbolic (struct gdbarch *gdbarch, CORE_ADDR addr,
521 			struct ui_file *stream,
522 			int do_demangle, const char *leadin)
523 {
524   std::string name, filename;
525   int unmapped = 0;
526   int offset = 0;
527   int line = 0;
528 
529   if (build_address_symbolic (gdbarch, addr, do_demangle, &name, &offset,
530 			      &filename, &line, &unmapped))
531     return 0;
532 
533   fputs_filtered (leadin, stream);
534   if (unmapped)
535     fputs_filtered ("<*", stream);
536   else
537     fputs_filtered ("<", stream);
538   fputs_styled (name.c_str (), function_name_style.style (), stream);
539   if (offset != 0)
540     fprintf_filtered (stream, "+%u", (unsigned int) offset);
541 
542   /* Append source filename and line number if desired.  Give specific
543      line # of this addr, if we have it; else line # of the nearest symbol.  */
544   if (print_symbol_filename && !filename.empty ())
545     {
546       fputs_filtered (line == -1 ? " in " : " at ", stream);
547       fputs_styled (filename.c_str (), file_name_style.style (), stream);
548       if (line != -1)
549 	fprintf_filtered (stream, ":%d", line);
550     }
551   if (unmapped)
552     fputs_filtered ("*>", stream);
553   else
554     fputs_filtered (">", stream);
555 
556   return 1;
557 }
558 
559 /* See valprint.h.  */
560 
561 int
562 build_address_symbolic (struct gdbarch *gdbarch,
563 			CORE_ADDR addr,  /* IN */
564 			int do_demangle, /* IN */
565 			std::string *name, /* OUT */
566 			int *offset,     /* OUT */
567 			std::string *filename, /* OUT */
568 			int *line,       /* OUT */
569 			int *unmapped)   /* OUT */
570 {
571   struct bound_minimal_symbol msymbol;
572   struct symbol *symbol;
573   CORE_ADDR name_location = 0;
574   struct obj_section *section = NULL;
575   const char *name_temp = "";
576 
577   /* Let's say it is mapped (not unmapped).  */
578   *unmapped = 0;
579 
580   /* Determine if the address is in an overlay, and whether it is
581      mapped.  */
582   if (overlay_debugging)
583     {
584       section = find_pc_overlay (addr);
585       if (pc_in_unmapped_range (addr, section))
586 	{
587 	  *unmapped = 1;
588 	  addr = overlay_mapped_address (addr, section);
589 	}
590     }
591 
592   /* First try to find the address in the symbol table, then
593      in the minsyms.  Take the closest one.  */
594 
595   /* This is defective in the sense that it only finds text symbols.  So
596      really this is kind of pointless--we should make sure that the
597      minimal symbols have everything we need (by changing that we could
598      save some memory, but for many debug format--ELF/DWARF or
599      anything/stabs--it would be inconvenient to eliminate those minimal
600      symbols anyway).  */
601   msymbol = lookup_minimal_symbol_by_pc_section (addr, section);
602   symbol = find_pc_sect_function (addr, section);
603 
604   if (symbol)
605     {
606       /* If this is a function (i.e. a code address), strip out any
607 	 non-address bits.  For instance, display a pointer to the
608 	 first instruction of a Thumb function as <function>; the
609 	 second instruction will be <function+2>, even though the
610 	 pointer is <function+3>.  This matches the ISA behavior.  */
611       addr = gdbarch_addr_bits_remove (gdbarch, addr);
612 
613       name_location = BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (symbol));
614       if (do_demangle || asm_demangle)
615 	name_temp = SYMBOL_PRINT_NAME (symbol);
616       else
617 	name_temp = SYMBOL_LINKAGE_NAME (symbol);
618     }
619 
620   if (msymbol.minsym != NULL
621       && MSYMBOL_HAS_SIZE (msymbol.minsym)
622       && MSYMBOL_SIZE (msymbol.minsym) == 0
623       && MSYMBOL_TYPE (msymbol.minsym) != mst_text
624       && MSYMBOL_TYPE (msymbol.minsym) != mst_text_gnu_ifunc
625       && MSYMBOL_TYPE (msymbol.minsym) != mst_file_text)
626     msymbol.minsym = NULL;
627 
628   if (msymbol.minsym != NULL)
629     {
630       if (BMSYMBOL_VALUE_ADDRESS (msymbol) > name_location || symbol == NULL)
631 	{
632 	  /* If this is a function (i.e. a code address), strip out any
633 	     non-address bits.  For instance, display a pointer to the
634 	     first instruction of a Thumb function as <function>; the
635 	     second instruction will be <function+2>, even though the
636 	     pointer is <function+3>.  This matches the ISA behavior.  */
637 	  if (MSYMBOL_TYPE (msymbol.minsym) == mst_text
638 	      || MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc
639 	      || MSYMBOL_TYPE (msymbol.minsym) == mst_file_text
640 	      || MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline)
641 	    addr = gdbarch_addr_bits_remove (gdbarch, addr);
642 
643 	  /* The msymbol is closer to the address than the symbol;
644 	     use the msymbol instead.  */
645 	  symbol = 0;
646 	  name_location = BMSYMBOL_VALUE_ADDRESS (msymbol);
647 	  if (do_demangle || asm_demangle)
648 	    name_temp = MSYMBOL_PRINT_NAME (msymbol.minsym);
649 	  else
650 	    name_temp = MSYMBOL_LINKAGE_NAME (msymbol.minsym);
651 	}
652     }
653   if (symbol == NULL && msymbol.minsym == NULL)
654     return 1;
655 
656   /* If the nearest symbol is too far away, don't print anything symbolic.  */
657 
658   /* For when CORE_ADDR is larger than unsigned int, we do math in
659      CORE_ADDR.  But when we detect unsigned wraparound in the
660      CORE_ADDR math, we ignore this test and print the offset,
661      because addr+max_symbolic_offset has wrapped through the end
662      of the address space back to the beginning, giving bogus comparison.  */
663   if (addr > name_location + max_symbolic_offset
664       && name_location + max_symbolic_offset > name_location)
665     return 1;
666 
667   *offset = addr - name_location;
668 
669   *name = name_temp;
670 
671   if (print_symbol_filename)
672     {
673       struct symtab_and_line sal;
674 
675       sal = find_pc_sect_line (addr, section, 0);
676 
677       if (sal.symtab)
678 	{
679 	  *filename = symtab_to_filename_for_display (sal.symtab);
680 	  *line = sal.line;
681 	}
682     }
683   return 0;
684 }
685 
686 
687 /* Print address ADDR symbolically on STREAM.
688    First print it as a number.  Then perhaps print
689    <SYMBOL + OFFSET> after the number.  */
690 
691 void
692 print_address (struct gdbarch *gdbarch,
693 	       CORE_ADDR addr, struct ui_file *stream)
694 {
695   fputs_styled (paddress (gdbarch, addr), address_style.style (), stream);
696   print_address_symbolic (gdbarch, addr, stream, asm_demangle, " ");
697 }
698 
699 /* Return a prefix for instruction address:
700    "=> " for current instruction, else "   ".  */
701 
702 const char *
703 pc_prefix (CORE_ADDR addr)
704 {
705   if (has_stack_frames ())
706     {
707       struct frame_info *frame;
708       CORE_ADDR pc;
709 
710       frame = get_selected_frame (NULL);
711       if (get_frame_pc_if_available (frame, &pc) && pc == addr)
712 	return "=> ";
713     }
714   return "   ";
715 }
716 
717 /* Print address ADDR symbolically on STREAM.  Parameter DEMANGLE
718    controls whether to print the symbolic name "raw" or demangled.
719    Return non-zero if anything was printed; zero otherwise.  */
720 
721 int
722 print_address_demangle (const struct value_print_options *opts,
723 			struct gdbarch *gdbarch, CORE_ADDR addr,
724 			struct ui_file *stream, int do_demangle)
725 {
726   if (opts->addressprint)
727     {
728       fputs_styled (paddress (gdbarch, addr), address_style.style (), stream);
729       print_address_symbolic (gdbarch, addr, stream, do_demangle, " ");
730     }
731   else
732     {
733       return print_address_symbolic (gdbarch, addr, stream, do_demangle, "");
734     }
735   return 1;
736 }
737 
738 
739 /* Find the address of the instruction that is INST_COUNT instructions before
740    the instruction at ADDR.
741    Since some architectures have variable-length instructions, we can't just
742    simply subtract INST_COUNT * INSN_LEN from ADDR.  Instead, we use line
743    number information to locate the nearest known instruction boundary,
744    and disassemble forward from there.  If we go out of the symbol range
745    during disassembling, we return the lowest address we've got so far and
746    set the number of instructions read to INST_READ.  */
747 
748 static CORE_ADDR
749 find_instruction_backward (struct gdbarch *gdbarch, CORE_ADDR addr,
750                            int inst_count, int *inst_read)
751 {
752   /* The vector PCS is used to store instruction addresses within
753      a pc range.  */
754   CORE_ADDR loop_start, loop_end, p;
755   std::vector<CORE_ADDR> pcs;
756   struct symtab_and_line sal;
757 
758   *inst_read = 0;
759   loop_start = loop_end = addr;
760 
761   /* In each iteration of the outer loop, we get a pc range that ends before
762      LOOP_START, then we count and store every instruction address of the range
763      iterated in the loop.
764      If the number of instructions counted reaches INST_COUNT, return the
765      stored address that is located INST_COUNT instructions back from ADDR.
766      If INST_COUNT is not reached, we subtract the number of counted
767      instructions from INST_COUNT, and go to the next iteration.  */
768   do
769     {
770       pcs.clear ();
771       sal = find_pc_sect_line (loop_start, NULL, 1);
772       if (sal.line <= 0)
773         {
774           /* We reach here when line info is not available.  In this case,
775              we print a message and just exit the loop.  The return value
776              is calculated after the loop.  */
777           printf_filtered (_("No line number information available "
778                              "for address "));
779           wrap_here ("  ");
780           print_address (gdbarch, loop_start - 1, gdb_stdout);
781           printf_filtered ("\n");
782           break;
783         }
784 
785       loop_end = loop_start;
786       loop_start = sal.pc;
787 
788       /* This loop pushes instruction addresses in the range from
789          LOOP_START to LOOP_END.  */
790       for (p = loop_start; p < loop_end;)
791         {
792 	  pcs.push_back (p);
793           p += gdb_insn_length (gdbarch, p);
794         }
795 
796       inst_count -= pcs.size ();
797       *inst_read += pcs.size ();
798     }
799   while (inst_count > 0);
800 
801   /* After the loop, the vector PCS has instruction addresses of the last
802      source line we processed, and INST_COUNT has a negative value.
803      We return the address at the index of -INST_COUNT in the vector for
804      the reason below.
805      Let's assume the following instruction addresses and run 'x/-4i 0x400e'.
806        Line X of File
807           0x4000
808           0x4001
809           0x4005
810        Line Y of File
811           0x4009
812           0x400c
813        => 0x400e
814           0x4011
815      find_instruction_backward is called with INST_COUNT = 4 and expected to
816      return 0x4001.  When we reach here, INST_COUNT is set to -1 because
817      it was subtracted by 2 (from Line Y) and 3 (from Line X).  The value
818      4001 is located at the index 1 of the last iterated line (= Line X),
819      which is simply calculated by -INST_COUNT.
820      The case when the length of PCS is 0 means that we reached an area for
821      which line info is not available.  In such case, we return LOOP_START,
822      which was the lowest instruction address that had line info.  */
823   p = pcs.size () > 0 ? pcs[-inst_count] : loop_start;
824 
825   /* INST_READ includes all instruction addresses in a pc range.  Need to
826      exclude the beginning part up to the address we're returning.  That
827      is, exclude {0x4000} in the example above.  */
828   if (inst_count < 0)
829     *inst_read += inst_count;
830 
831   return p;
832 }
833 
834 /* Backward read LEN bytes of target memory from address MEMADDR + LEN,
835    placing the results in GDB's memory from MYADDR + LEN.  Returns
836    a count of the bytes actually read.  */
837 
838 static int
839 read_memory_backward (struct gdbarch *gdbarch,
840                       CORE_ADDR memaddr, gdb_byte *myaddr, int len)
841 {
842   int errcode;
843   int nread;      /* Number of bytes actually read.  */
844 
845   /* First try a complete read.  */
846   errcode = target_read_memory (memaddr, myaddr, len);
847   if (errcode == 0)
848     {
849       /* Got it all.  */
850       nread = len;
851     }
852   else
853     {
854       /* Loop, reading one byte at a time until we get as much as we can.  */
855       memaddr += len;
856       myaddr += len;
857       for (nread = 0; nread < len; ++nread)
858         {
859           errcode = target_read_memory (--memaddr, --myaddr, 1);
860           if (errcode != 0)
861             {
862               /* The read was unsuccessful, so exit the loop.  */
863               printf_filtered (_("Cannot access memory at address %s\n"),
864                                paddress (gdbarch, memaddr));
865               break;
866             }
867         }
868     }
869   return nread;
870 }
871 
872 /* Returns true if X (which is LEN bytes wide) is the number zero.  */
873 
874 static int
875 integer_is_zero (const gdb_byte *x, int len)
876 {
877   int i = 0;
878 
879   while (i < len && x[i] == 0)
880     ++i;
881   return (i == len);
882 }
883 
884 /* Find the start address of a string in which ADDR is included.
885    Basically we search for '\0' and return the next address,
886    but if OPTIONS->PRINT_MAX is smaller than the length of a string,
887    we stop searching and return the address to print characters as many as
888    PRINT_MAX from the string.  */
889 
890 static CORE_ADDR
891 find_string_backward (struct gdbarch *gdbarch,
892                       CORE_ADDR addr, int count, int char_size,
893                       const struct value_print_options *options,
894                       int *strings_counted)
895 {
896   const int chunk_size = 0x20;
897   int read_error = 0;
898   int chars_read = 0;
899   int chars_to_read = chunk_size;
900   int chars_counted = 0;
901   int count_original = count;
902   CORE_ADDR string_start_addr = addr;
903 
904   gdb_assert (char_size == 1 || char_size == 2 || char_size == 4);
905   gdb::byte_vector buffer (chars_to_read * char_size);
906   while (count > 0 && read_error == 0)
907     {
908       int i;
909 
910       addr -= chars_to_read * char_size;
911       chars_read = read_memory_backward (gdbarch, addr, buffer.data (),
912                                          chars_to_read * char_size);
913       chars_read /= char_size;
914       read_error = (chars_read == chars_to_read) ? 0 : 1;
915       /* Searching for '\0' from the end of buffer in backward direction.  */
916       for (i = 0; i < chars_read && count > 0 ; ++i, ++chars_counted)
917         {
918           int offset = (chars_to_read - i - 1) * char_size;
919 
920           if (integer_is_zero (&buffer[offset], char_size)
921               || chars_counted == options->print_max)
922             {
923               /* Found '\0' or reached print_max.  As OFFSET is the offset to
924                  '\0', we add CHAR_SIZE to return the start address of
925                  a string.  */
926               --count;
927               string_start_addr = addr + offset + char_size;
928               chars_counted = 0;
929             }
930         }
931     }
932 
933   /* Update STRINGS_COUNTED with the actual number of loaded strings.  */
934   *strings_counted = count_original - count;
935 
936   if (read_error != 0)
937     {
938       /* In error case, STRING_START_ADDR is pointing to the string that
939          was last successfully loaded.  Rewind the partially loaded string.  */
940       string_start_addr -= chars_counted * char_size;
941     }
942 
943   return string_start_addr;
944 }
945 
946 /* Examine data at address ADDR in format FMT.
947    Fetch it from memory and print on gdb_stdout.  */
948 
949 static void
950 do_examine (struct format_data fmt, struct gdbarch *gdbarch, CORE_ADDR addr)
951 {
952   char format = 0;
953   char size;
954   int count = 1;
955   struct type *val_type = NULL;
956   int i;
957   int maxelts;
958   struct value_print_options opts;
959   int need_to_update_next_address = 0;
960   CORE_ADDR addr_rewound = 0;
961 
962   format = fmt.format;
963   size = fmt.size;
964   count = fmt.count;
965   next_gdbarch = gdbarch;
966   next_address = addr;
967 
968   /* Instruction format implies fetch single bytes
969      regardless of the specified size.
970      The case of strings is handled in decode_format, only explicit
971      size operator are not changed to 'b'.  */
972   if (format == 'i')
973     size = 'b';
974 
975   if (size == 'a')
976     {
977       /* Pick the appropriate size for an address.  */
978       if (gdbarch_ptr_bit (next_gdbarch) == 64)
979 	size = 'g';
980       else if (gdbarch_ptr_bit (next_gdbarch) == 32)
981 	size = 'w';
982       else if (gdbarch_ptr_bit (next_gdbarch) == 16)
983 	size = 'h';
984       else
985 	/* Bad value for gdbarch_ptr_bit.  */
986 	internal_error (__FILE__, __LINE__,
987 			_("failed internal consistency check"));
988     }
989 
990   if (size == 'b')
991     val_type = builtin_type (next_gdbarch)->builtin_int8;
992   else if (size == 'h')
993     val_type = builtin_type (next_gdbarch)->builtin_int16;
994   else if (size == 'w')
995     val_type = builtin_type (next_gdbarch)->builtin_int32;
996   else if (size == 'g')
997     val_type = builtin_type (next_gdbarch)->builtin_int64;
998 
999   if (format == 's')
1000     {
1001       struct type *char_type = NULL;
1002 
1003       /* Search for "char16_t"  or "char32_t" types or fall back to 8-bit char
1004 	 if type is not found.  */
1005       if (size == 'h')
1006 	char_type = builtin_type (next_gdbarch)->builtin_char16;
1007       else if (size == 'w')
1008 	char_type = builtin_type (next_gdbarch)->builtin_char32;
1009       if (char_type)
1010         val_type = char_type;
1011       else
1012         {
1013 	  if (size != '\0' && size != 'b')
1014 	    warning (_("Unable to display strings with "
1015 		       "size '%c', using 'b' instead."), size);
1016 	  size = 'b';
1017 	  val_type = builtin_type (next_gdbarch)->builtin_int8;
1018         }
1019     }
1020 
1021   maxelts = 8;
1022   if (size == 'w')
1023     maxelts = 4;
1024   if (size == 'g')
1025     maxelts = 2;
1026   if (format == 's' || format == 'i')
1027     maxelts = 1;
1028 
1029   get_formatted_print_options (&opts, format);
1030 
1031   if (count < 0)
1032     {
1033       /* This is the negative repeat count case.
1034          We rewind the address based on the given repeat count and format,
1035          then examine memory from there in forward direction.  */
1036 
1037       count = -count;
1038       if (format == 'i')
1039         {
1040           next_address = find_instruction_backward (gdbarch, addr, count,
1041                                                     &count);
1042         }
1043       else if (format == 's')
1044         {
1045           next_address = find_string_backward (gdbarch, addr, count,
1046                                                TYPE_LENGTH (val_type),
1047                                                &opts, &count);
1048         }
1049       else
1050         {
1051           next_address = addr - count * TYPE_LENGTH (val_type);
1052         }
1053 
1054       /* The following call to print_formatted updates next_address in every
1055          iteration.  In backward case, we store the start address here
1056          and update next_address with it before exiting the function.  */
1057       addr_rewound = (format == 's'
1058                       ? next_address - TYPE_LENGTH (val_type)
1059                       : next_address);
1060       need_to_update_next_address = 1;
1061     }
1062 
1063   /* Print as many objects as specified in COUNT, at most maxelts per line,
1064      with the address of the next one at the start of each line.  */
1065 
1066   while (count > 0)
1067     {
1068       QUIT;
1069       if (format == 'i')
1070 	fputs_filtered (pc_prefix (next_address), gdb_stdout);
1071       print_address (next_gdbarch, next_address, gdb_stdout);
1072       printf_filtered (":");
1073       for (i = maxelts;
1074 	   i > 0 && count > 0;
1075 	   i--, count--)
1076 	{
1077 	  printf_filtered ("\t");
1078 	  /* Note that print_formatted sets next_address for the next
1079 	     object.  */
1080 	  last_examine_address = next_address;
1081 
1082 	  /* The value to be displayed is not fetched greedily.
1083 	     Instead, to avoid the possibility of a fetched value not
1084 	     being used, its retrieval is delayed until the print code
1085 	     uses it.  When examining an instruction stream, the
1086 	     disassembler will perform its own memory fetch using just
1087 	     the address stored in LAST_EXAMINE_VALUE.  FIXME: Should
1088 	     the disassembler be modified so that LAST_EXAMINE_VALUE
1089 	     is left with the byte sequence from the last complete
1090 	     instruction fetched from memory?  */
1091 	  last_examine_value
1092 	    = release_value (value_at_lazy (val_type, next_address));
1093 
1094 	  print_formatted (last_examine_value.get (), size, &opts, gdb_stdout);
1095 
1096 	  /* Display any branch delay slots following the final insn.  */
1097 	  if (format == 'i' && count == 1)
1098 	    count += branch_delay_insns;
1099 	}
1100       printf_filtered ("\n");
1101       gdb_flush (gdb_stdout);
1102     }
1103 
1104   if (need_to_update_next_address)
1105     next_address = addr_rewound;
1106 }
1107 
1108 static void
1109 validate_format (struct format_data fmt, const char *cmdname)
1110 {
1111   if (fmt.size != 0)
1112     error (_("Size letters are meaningless in \"%s\" command."), cmdname);
1113   if (fmt.count != 1)
1114     error (_("Item count other than 1 is meaningless in \"%s\" command."),
1115 	   cmdname);
1116   if (fmt.format == 'i')
1117     error (_("Format letter \"%c\" is meaningless in \"%s\" command."),
1118 	   fmt.format, cmdname);
1119 }
1120 
1121 /* Parse print command format string into *FMTP and update *EXPP.
1122    CMDNAME should name the current command.  */
1123 
1124 void
1125 print_command_parse_format (const char **expp, const char *cmdname,
1126 			    struct format_data *fmtp)
1127 {
1128   const char *exp = *expp;
1129 
1130   if (exp && *exp == '/')
1131     {
1132       exp++;
1133       *fmtp = decode_format (&exp, last_format, 0);
1134       validate_format (*fmtp, cmdname);
1135       last_format = fmtp->format;
1136     }
1137   else
1138     {
1139       fmtp->count = 1;
1140       fmtp->format = 0;
1141       fmtp->size = 0;
1142       fmtp->raw = 0;
1143     }
1144 
1145   *expp = exp;
1146 }
1147 
1148 /* Print VAL to console according to *FMTP, including recording it to
1149    the history.  */
1150 
1151 void
1152 print_value (struct value *val, const struct format_data *fmtp)
1153 {
1154   struct value_print_options opts;
1155   int histindex = record_latest_value (val);
1156 
1157   annotate_value_history_begin (histindex, value_type (val));
1158 
1159   printf_filtered ("$%d = ", histindex);
1160 
1161   annotate_value_history_value ();
1162 
1163   get_formatted_print_options (&opts, fmtp->format);
1164   opts.raw = fmtp->raw;
1165 
1166   print_formatted (val, fmtp->size, &opts, gdb_stdout);
1167   printf_filtered ("\n");
1168 
1169   annotate_value_history_end ();
1170 }
1171 
1172 /* Evaluate string EXP as an expression in the current language and
1173    print the resulting value.  EXP may contain a format specifier as the
1174    first argument ("/x myvar" for example, to print myvar in hex).  */
1175 
1176 static void
1177 print_command_1 (const char *exp, int voidprint)
1178 {
1179   struct value *val;
1180   struct format_data fmt;
1181 
1182   print_command_parse_format (&exp, "print", &fmt);
1183 
1184   if (exp && *exp)
1185     {
1186       expression_up expr = parse_expression (exp);
1187       val = evaluate_expression (expr.get ());
1188     }
1189   else
1190     val = access_value_history (0);
1191 
1192   if (voidprint || (val && value_type (val) &&
1193 		    TYPE_CODE (value_type (val)) != TYPE_CODE_VOID))
1194     print_value (val, &fmt);
1195 }
1196 
1197 static void
1198 print_command (const char *exp, int from_tty)
1199 {
1200   print_command_1 (exp, 1);
1201 }
1202 
1203 /* Same as print, except it doesn't print void results.  */
1204 static void
1205 call_command (const char *exp, int from_tty)
1206 {
1207   print_command_1 (exp, 0);
1208 }
1209 
1210 /* Implementation of the "output" command.  */
1211 
1212 void
1213 output_command (const char *exp, int from_tty)
1214 {
1215   char format = 0;
1216   struct value *val;
1217   struct format_data fmt;
1218   struct value_print_options opts;
1219 
1220   fmt.size = 0;
1221   fmt.raw = 0;
1222 
1223   if (exp && *exp == '/')
1224     {
1225       exp++;
1226       fmt = decode_format (&exp, 0, 0);
1227       validate_format (fmt, "output");
1228       format = fmt.format;
1229     }
1230 
1231   expression_up expr = parse_expression (exp);
1232 
1233   val = evaluate_expression (expr.get ());
1234 
1235   annotate_value_begin (value_type (val));
1236 
1237   get_formatted_print_options (&opts, format);
1238   opts.raw = fmt.raw;
1239   print_formatted (val, fmt.size, &opts, gdb_stdout);
1240 
1241   annotate_value_end ();
1242 
1243   wrap_here ("");
1244   gdb_flush (gdb_stdout);
1245 }
1246 
1247 static void
1248 set_command (const char *exp, int from_tty)
1249 {
1250   expression_up expr = parse_expression (exp);
1251 
1252   if (expr->nelts >= 1)
1253     switch (expr->elts[0].opcode)
1254       {
1255       case UNOP_PREINCREMENT:
1256       case UNOP_POSTINCREMENT:
1257       case UNOP_PREDECREMENT:
1258       case UNOP_POSTDECREMENT:
1259       case BINOP_ASSIGN:
1260       case BINOP_ASSIGN_MODIFY:
1261       case BINOP_COMMA:
1262 	break;
1263       default:
1264 	warning
1265 	  (_("Expression is not an assignment (and might have no effect)"));
1266       }
1267 
1268   evaluate_expression (expr.get ());
1269 }
1270 
1271 static void
1272 info_symbol_command (const char *arg, int from_tty)
1273 {
1274   struct minimal_symbol *msymbol;
1275   struct obj_section *osect;
1276   CORE_ADDR addr, sect_addr;
1277   int matches = 0;
1278   unsigned int offset;
1279 
1280   if (!arg)
1281     error_no_arg (_("address"));
1282 
1283   addr = parse_and_eval_address (arg);
1284   for (objfile *objfile : current_program_space->objfiles ())
1285     ALL_OBJFILE_OSECTIONS (objfile, osect)
1286       {
1287 	/* Only process each object file once, even if there's a separate
1288 	   debug file.  */
1289 	if (objfile->separate_debug_objfile_backlink)
1290 	  continue;
1291 
1292 	sect_addr = overlay_mapped_address (addr, osect);
1293 
1294 	if (obj_section_addr (osect) <= sect_addr
1295 	    && sect_addr < obj_section_endaddr (osect)
1296 	    && (msymbol
1297 		= lookup_minimal_symbol_by_pc_section (sect_addr,
1298 						       osect).minsym))
1299 	  {
1300 	    const char *obj_name, *mapped, *sec_name, *msym_name;
1301 	    const char *loc_string;
1302 
1303 	    matches = 1;
1304 	    offset = sect_addr - MSYMBOL_VALUE_ADDRESS (objfile, msymbol);
1305 	    mapped = section_is_mapped (osect) ? _("mapped") : _("unmapped");
1306 	    sec_name = osect->the_bfd_section->name;
1307 	    msym_name = MSYMBOL_PRINT_NAME (msymbol);
1308 
1309 	    /* Don't print the offset if it is zero.
1310 	       We assume there's no need to handle i18n of "sym + offset".  */
1311 	    std::string string_holder;
1312 	    if (offset)
1313 	      {
1314 		string_holder = string_printf ("%s + %u", msym_name, offset);
1315 		loc_string = string_holder.c_str ();
1316 	      }
1317 	    else
1318 	      loc_string = msym_name;
1319 
1320 	    gdb_assert (osect->objfile && objfile_name (osect->objfile));
1321 	    obj_name = objfile_name (osect->objfile);
1322 
1323 	    if (MULTI_OBJFILE_P ())
1324 	      if (pc_in_unmapped_range (addr, osect))
1325 		if (section_is_overlay (osect))
1326 		  printf_filtered (_("%s in load address range of "
1327 				     "%s overlay section %s of %s\n"),
1328 				   loc_string, mapped, sec_name, obj_name);
1329 		else
1330 		  printf_filtered (_("%s in load address range of "
1331 				     "section %s of %s\n"),
1332 				   loc_string, sec_name, obj_name);
1333 	      else
1334 		if (section_is_overlay (osect))
1335 		  printf_filtered (_("%s in %s overlay section %s of %s\n"),
1336 				   loc_string, mapped, sec_name, obj_name);
1337 		else
1338 		  printf_filtered (_("%s in section %s of %s\n"),
1339 				   loc_string, sec_name, obj_name);
1340 	    else
1341 	      if (pc_in_unmapped_range (addr, osect))
1342 		if (section_is_overlay (osect))
1343 		  printf_filtered (_("%s in load address range of %s overlay "
1344 				     "section %s\n"),
1345 				   loc_string, mapped, sec_name);
1346 		else
1347 		  printf_filtered
1348 		    (_("%s in load address range of section %s\n"),
1349 		     loc_string, sec_name);
1350 	      else
1351 		if (section_is_overlay (osect))
1352 		  printf_filtered (_("%s in %s overlay section %s\n"),
1353 				   loc_string, mapped, sec_name);
1354 		else
1355 		  printf_filtered (_("%s in section %s\n"),
1356 				   loc_string, sec_name);
1357 	  }
1358       }
1359   if (matches == 0)
1360     printf_filtered (_("No symbol matches %s.\n"), arg);
1361 }
1362 
1363 static void
1364 info_address_command (const char *exp, int from_tty)
1365 {
1366   struct gdbarch *gdbarch;
1367   int regno;
1368   struct symbol *sym;
1369   struct bound_minimal_symbol msymbol;
1370   long val;
1371   struct obj_section *section;
1372   CORE_ADDR load_addr, context_pc = 0;
1373   struct field_of_this_result is_a_field_of_this;
1374 
1375   if (exp == 0)
1376     error (_("Argument required."));
1377 
1378   sym = lookup_symbol (exp, get_selected_block (&context_pc), VAR_DOMAIN,
1379 		       &is_a_field_of_this).symbol;
1380   if (sym == NULL)
1381     {
1382       if (is_a_field_of_this.type != NULL)
1383 	{
1384 	  printf_filtered ("Symbol \"");
1385 	  fprintf_symbol_filtered (gdb_stdout, exp,
1386 				   current_language->la_language, DMGL_ANSI);
1387 	  printf_filtered ("\" is a field of the local class variable ");
1388 	  if (current_language->la_language == language_objc)
1389 	    printf_filtered ("`self'\n");	/* ObjC equivalent of "this" */
1390 	  else
1391 	    printf_filtered ("`this'\n");
1392 	  return;
1393 	}
1394 
1395       msymbol = lookup_bound_minimal_symbol (exp);
1396 
1397       if (msymbol.minsym != NULL)
1398 	{
1399 	  struct objfile *objfile = msymbol.objfile;
1400 
1401 	  gdbarch = get_objfile_arch (objfile);
1402 	  load_addr = BMSYMBOL_VALUE_ADDRESS (msymbol);
1403 
1404 	  printf_filtered ("Symbol \"");
1405 	  fprintf_symbol_filtered (gdb_stdout, exp,
1406 				   current_language->la_language, DMGL_ANSI);
1407 	  printf_filtered ("\" is at ");
1408 	  fputs_styled (paddress (gdbarch, load_addr), address_style.style (),
1409 			gdb_stdout);
1410 	  printf_filtered (" in a file compiled without debugging");
1411 	  section = MSYMBOL_OBJ_SECTION (objfile, msymbol.minsym);
1412 	  if (section_is_overlay (section))
1413 	    {
1414 	      load_addr = overlay_unmapped_address (load_addr, section);
1415 	      printf_filtered (",\n -- loaded at ");
1416 	      fputs_styled (paddress (gdbarch, load_addr),
1417 			    address_style.style (),
1418 			    gdb_stdout);
1419 	      printf_filtered (" in overlay section %s",
1420 			       section->the_bfd_section->name);
1421 	    }
1422 	  printf_filtered (".\n");
1423 	}
1424       else
1425 	error (_("No symbol \"%s\" in current context."), exp);
1426       return;
1427     }
1428 
1429   printf_filtered ("Symbol \"");
1430   fprintf_symbol_filtered (gdb_stdout, SYMBOL_PRINT_NAME (sym),
1431 			   current_language->la_language, DMGL_ANSI);
1432   printf_filtered ("\" is ");
1433   val = SYMBOL_VALUE (sym);
1434   if (SYMBOL_OBJFILE_OWNED (sym))
1435     section = SYMBOL_OBJ_SECTION (symbol_objfile (sym), sym);
1436   else
1437     section = NULL;
1438   gdbarch = symbol_arch (sym);
1439 
1440   if (SYMBOL_COMPUTED_OPS (sym) != NULL)
1441     {
1442       SYMBOL_COMPUTED_OPS (sym)->describe_location (sym, context_pc,
1443 						    gdb_stdout);
1444       printf_filtered (".\n");
1445       return;
1446     }
1447 
1448   switch (SYMBOL_CLASS (sym))
1449     {
1450     case LOC_CONST:
1451     case LOC_CONST_BYTES:
1452       printf_filtered ("constant");
1453       break;
1454 
1455     case LOC_LABEL:
1456       printf_filtered ("a label at address ");
1457       load_addr = SYMBOL_VALUE_ADDRESS (sym);
1458       fputs_styled (paddress (gdbarch, load_addr), address_style.style (),
1459 		    gdb_stdout);
1460       if (section_is_overlay (section))
1461 	{
1462 	  load_addr = overlay_unmapped_address (load_addr, section);
1463 	  printf_filtered (",\n -- loaded at ");
1464 	  fputs_styled (paddress (gdbarch, load_addr), address_style.style (),
1465 			gdb_stdout);
1466 	  printf_filtered (" in overlay section %s",
1467 			   section->the_bfd_section->name);
1468 	}
1469       break;
1470 
1471     case LOC_COMPUTED:
1472       gdb_assert_not_reached (_("LOC_COMPUTED variable missing a method"));
1473 
1474     case LOC_REGISTER:
1475       /* GDBARCH is the architecture associated with the objfile the symbol
1476 	 is defined in; the target architecture may be different, and may
1477 	 provide additional registers.  However, we do not know the target
1478 	 architecture at this point.  We assume the objfile architecture
1479 	 will contain all the standard registers that occur in debug info
1480 	 in that objfile.  */
1481       regno = SYMBOL_REGISTER_OPS (sym)->register_number (sym, gdbarch);
1482 
1483       if (SYMBOL_IS_ARGUMENT (sym))
1484 	printf_filtered (_("an argument in register %s"),
1485 			 gdbarch_register_name (gdbarch, regno));
1486       else
1487 	printf_filtered (_("a variable in register %s"),
1488 			 gdbarch_register_name (gdbarch, regno));
1489       break;
1490 
1491     case LOC_STATIC:
1492       printf_filtered (_("static storage at address "));
1493       load_addr = SYMBOL_VALUE_ADDRESS (sym);
1494       fputs_styled (paddress (gdbarch, load_addr), address_style.style (),
1495 		    gdb_stdout);
1496       if (section_is_overlay (section))
1497 	{
1498 	  load_addr = overlay_unmapped_address (load_addr, section);
1499 	  printf_filtered (_(",\n -- loaded at "));
1500 	  fputs_styled (paddress (gdbarch, load_addr), address_style.style (),
1501 			gdb_stdout);
1502 	  printf_filtered (_(" in overlay section %s"),
1503 			   section->the_bfd_section->name);
1504 	}
1505       break;
1506 
1507     case LOC_REGPARM_ADDR:
1508       /* Note comment at LOC_REGISTER.  */
1509       regno = SYMBOL_REGISTER_OPS (sym)->register_number (sym, gdbarch);
1510       printf_filtered (_("address of an argument in register %s"),
1511 		       gdbarch_register_name (gdbarch, regno));
1512       break;
1513 
1514     case LOC_ARG:
1515       printf_filtered (_("an argument at offset %ld"), val);
1516       break;
1517 
1518     case LOC_LOCAL:
1519       printf_filtered (_("a local variable at frame offset %ld"), val);
1520       break;
1521 
1522     case LOC_REF_ARG:
1523       printf_filtered (_("a reference argument at offset %ld"), val);
1524       break;
1525 
1526     case LOC_TYPEDEF:
1527       printf_filtered (_("a typedef"));
1528       break;
1529 
1530     case LOC_BLOCK:
1531       printf_filtered (_("a function at address "));
1532       load_addr = BLOCK_ENTRY_PC (SYMBOL_BLOCK_VALUE (sym));
1533       fputs_styled (paddress (gdbarch, load_addr), address_style.style (),
1534 		    gdb_stdout);
1535       if (section_is_overlay (section))
1536 	{
1537 	  load_addr = overlay_unmapped_address (load_addr, section);
1538 	  printf_filtered (_(",\n -- loaded at "));
1539 	  fputs_styled (paddress (gdbarch, load_addr), address_style.style (),
1540 			gdb_stdout);
1541 	  printf_filtered (_(" in overlay section %s"),
1542 			   section->the_bfd_section->name);
1543 	}
1544       break;
1545 
1546     case LOC_UNRESOLVED:
1547       {
1548 	struct bound_minimal_symbol msym;
1549 
1550 	msym = lookup_bound_minimal_symbol (SYMBOL_LINKAGE_NAME (sym));
1551 	if (msym.minsym == NULL)
1552 	  printf_filtered ("unresolved");
1553 	else
1554 	  {
1555 	    section = MSYMBOL_OBJ_SECTION (msym.objfile, msym.minsym);
1556 
1557 	    if (section
1558 		&& (section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0)
1559 	      {
1560 		load_addr = MSYMBOL_VALUE_RAW_ADDRESS (msym.minsym);
1561 		printf_filtered (_("a thread-local variable at offset %s "
1562 				   "in the thread-local storage for `%s'"),
1563 				 paddress (gdbarch, load_addr),
1564 				 objfile_name (section->objfile));
1565 	      }
1566 	    else
1567 	      {
1568 		load_addr = BMSYMBOL_VALUE_ADDRESS (msym);
1569 		printf_filtered (_("static storage at address "));
1570 		fputs_styled (paddress (gdbarch, load_addr),
1571 			      address_style.style (), gdb_stdout);
1572 		if (section_is_overlay (section))
1573 		  {
1574 		    load_addr = overlay_unmapped_address (load_addr, section);
1575 		    printf_filtered (_(",\n -- loaded at "));
1576 		    fputs_styled (paddress (gdbarch, load_addr),
1577 				  address_style.style (),
1578 				  gdb_stdout);
1579 		    printf_filtered (_(" in overlay section %s"),
1580 				     section->the_bfd_section->name);
1581 		  }
1582 	      }
1583 	  }
1584       }
1585       break;
1586 
1587     case LOC_OPTIMIZED_OUT:
1588       printf_filtered (_("optimized out"));
1589       break;
1590 
1591     default:
1592       printf_filtered (_("of unknown (botched) type"));
1593       break;
1594     }
1595   printf_filtered (".\n");
1596 }
1597 
1598 
1599 static void
1600 x_command (const char *exp, int from_tty)
1601 {
1602   struct format_data fmt;
1603   struct value *val;
1604 
1605   fmt.format = last_format ? last_format : 'x';
1606   fmt.size = last_size;
1607   fmt.count = 1;
1608   fmt.raw = 0;
1609 
1610   /* If there is no expression and no format, use the most recent
1611      count.  */
1612   if (exp == nullptr && last_count > 0)
1613     fmt.count = last_count;
1614 
1615   if (exp && *exp == '/')
1616     {
1617       const char *tmp = exp + 1;
1618 
1619       fmt = decode_format (&tmp, last_format, last_size);
1620       exp = (char *) tmp;
1621     }
1622 
1623   last_count = fmt.count;
1624 
1625   /* If we have an expression, evaluate it and use it as the address.  */
1626 
1627   if (exp != 0 && *exp != 0)
1628     {
1629       expression_up expr = parse_expression (exp);
1630       /* Cause expression not to be there any more if this command is
1631          repeated with Newline.  But don't clobber a user-defined
1632          command's definition.  */
1633       if (from_tty)
1634 	set_repeat_arguments ("");
1635       val = evaluate_expression (expr.get ());
1636       if (TYPE_IS_REFERENCE (value_type (val)))
1637 	val = coerce_ref (val);
1638       /* In rvalue contexts, such as this, functions are coerced into
1639          pointers to functions.  This makes "x/i main" work.  */
1640       if (/* last_format == 'i'  && */
1641 	  TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
1642 	   && VALUE_LVAL (val) == lval_memory)
1643 	next_address = value_address (val);
1644       else
1645 	next_address = value_as_address (val);
1646 
1647       next_gdbarch = expr->gdbarch;
1648     }
1649 
1650   if (!next_gdbarch)
1651     error_no_arg (_("starting display address"));
1652 
1653   do_examine (fmt, next_gdbarch, next_address);
1654 
1655   /* If the examine succeeds, we remember its size and format for next
1656      time.  Set last_size to 'b' for strings.  */
1657   if (fmt.format == 's')
1658     last_size = 'b';
1659   else
1660     last_size = fmt.size;
1661   last_format = fmt.format;
1662 
1663   /* Set a couple of internal variables if appropriate.  */
1664   if (last_examine_value != nullptr)
1665     {
1666       /* Make last address examined available to the user as $_.  Use
1667          the correct pointer type.  */
1668       struct type *pointer_type
1669 	= lookup_pointer_type (value_type (last_examine_value.get ()));
1670       set_internalvar (lookup_internalvar ("_"),
1671 		       value_from_pointer (pointer_type,
1672 					   last_examine_address));
1673 
1674       /* Make contents of last address examined available to the user
1675 	 as $__.  If the last value has not been fetched from memory
1676 	 then don't fetch it now; instead mark it by voiding the $__
1677 	 variable.  */
1678       if (value_lazy (last_examine_value.get ()))
1679 	clear_internalvar (lookup_internalvar ("__"));
1680       else
1681 	set_internalvar (lookup_internalvar ("__"), last_examine_value.get ());
1682     }
1683 }
1684 
1685 
1686 /* Add an expression to the auto-display chain.
1687    Specify the expression.  */
1688 
1689 static void
1690 display_command (const char *arg, int from_tty)
1691 {
1692   struct format_data fmt;
1693   struct display *newobj;
1694   const char *exp = arg;
1695 
1696   if (exp == 0)
1697     {
1698       do_displays ();
1699       return;
1700     }
1701 
1702   if (*exp == '/')
1703     {
1704       exp++;
1705       fmt = decode_format (&exp, 0, 0);
1706       if (fmt.size && fmt.format == 0)
1707 	fmt.format = 'x';
1708       if (fmt.format == 'i' || fmt.format == 's')
1709 	fmt.size = 'b';
1710     }
1711   else
1712     {
1713       fmt.format = 0;
1714       fmt.size = 0;
1715       fmt.count = 0;
1716       fmt.raw = 0;
1717     }
1718 
1719   innermost_block.reset ();
1720   expression_up expr = parse_expression (exp);
1721 
1722   newobj = new display ();
1723 
1724   newobj->exp_string = xstrdup (exp);
1725   newobj->exp = std::move (expr);
1726   newobj->block = innermost_block.block ();
1727   newobj->pspace = current_program_space;
1728   newobj->number = ++display_number;
1729   newobj->format = fmt;
1730   newobj->enabled_p = 1;
1731   newobj->next = NULL;
1732 
1733   if (display_chain == NULL)
1734     display_chain = newobj;
1735   else
1736     {
1737       struct display *last;
1738 
1739       for (last = display_chain; last->next != NULL; last = last->next)
1740 	;
1741       last->next = newobj;
1742     }
1743 
1744   if (from_tty)
1745     do_one_display (newobj);
1746 
1747   dont_repeat ();
1748 }
1749 
1750 static void
1751 free_display (struct display *d)
1752 {
1753   xfree (d->exp_string);
1754   delete d;
1755 }
1756 
1757 /* Clear out the display_chain.  Done when new symtabs are loaded,
1758    since this invalidates the types stored in many expressions.  */
1759 
1760 void
1761 clear_displays (void)
1762 {
1763   struct display *d;
1764 
1765   while ((d = display_chain) != NULL)
1766     {
1767       display_chain = d->next;
1768       free_display (d);
1769     }
1770 }
1771 
1772 /* Delete the auto-display DISPLAY.  */
1773 
1774 static void
1775 delete_display (struct display *display)
1776 {
1777   struct display *d;
1778 
1779   gdb_assert (display != NULL);
1780 
1781   if (display_chain == display)
1782     display_chain = display->next;
1783 
1784   ALL_DISPLAYS (d)
1785     if (d->next == display)
1786       {
1787 	d->next = display->next;
1788 	break;
1789       }
1790 
1791   free_display (display);
1792 }
1793 
1794 /* Call FUNCTION on each of the displays whose numbers are given in
1795    ARGS.  DATA is passed unmodified to FUNCTION.  */
1796 
1797 static void
1798 map_display_numbers (const char *args,
1799 		     void (*function) (struct display *,
1800 				       void *),
1801 		     void *data)
1802 {
1803   int num;
1804 
1805   if (args == NULL)
1806     error_no_arg (_("one or more display numbers"));
1807 
1808   number_or_range_parser parser (args);
1809 
1810   while (!parser.finished ())
1811     {
1812       const char *p = parser.cur_tok ();
1813 
1814       num = parser.get_number ();
1815       if (num == 0)
1816 	warning (_("bad display number at or near '%s'"), p);
1817       else
1818 	{
1819 	  struct display *d, *tmp;
1820 
1821 	  ALL_DISPLAYS_SAFE (d, tmp)
1822 	    if (d->number == num)
1823 	      break;
1824 	  if (d == NULL)
1825 	    printf_unfiltered (_("No display number %d.\n"), num);
1826 	  else
1827 	    function (d, data);
1828 	}
1829     }
1830 }
1831 
1832 /* Callback for map_display_numbers, that deletes a display.  */
1833 
1834 static void
1835 do_delete_display (struct display *d, void *data)
1836 {
1837   delete_display (d);
1838 }
1839 
1840 /* "undisplay" command.  */
1841 
1842 static void
1843 undisplay_command (const char *args, int from_tty)
1844 {
1845   if (args == NULL)
1846     {
1847       if (query (_("Delete all auto-display expressions? ")))
1848 	clear_displays ();
1849       dont_repeat ();
1850       return;
1851     }
1852 
1853   map_display_numbers (args, do_delete_display, NULL);
1854   dont_repeat ();
1855 }
1856 
1857 /* Display a single auto-display.
1858    Do nothing if the display cannot be printed in the current context,
1859    or if the display is disabled.  */
1860 
1861 static void
1862 do_one_display (struct display *d)
1863 {
1864   int within_current_scope;
1865 
1866   if (d->enabled_p == 0)
1867     return;
1868 
1869   /* The expression carries the architecture that was used at parse time.
1870      This is a problem if the expression depends on architecture features
1871      (e.g. register numbers), and the current architecture is now different.
1872      For example, a display statement like "display/i $pc" is expected to
1873      display the PC register of the current architecture, not the arch at
1874      the time the display command was given.  Therefore, we re-parse the
1875      expression if the current architecture has changed.  */
1876   if (d->exp != NULL && d->exp->gdbarch != get_current_arch ())
1877     {
1878       d->exp.reset ();
1879       d->block = NULL;
1880     }
1881 
1882   if (d->exp == NULL)
1883     {
1884 
1885       TRY
1886 	{
1887 	  innermost_block.reset ();
1888 	  d->exp = parse_expression (d->exp_string);
1889 	  d->block = innermost_block.block ();
1890 	}
1891       CATCH (ex, RETURN_MASK_ALL)
1892 	{
1893 	  /* Can't re-parse the expression.  Disable this display item.  */
1894 	  d->enabled_p = 0;
1895 	  warning (_("Unable to display \"%s\": %s"),
1896 		   d->exp_string, ex.message);
1897 	  return;
1898 	}
1899       END_CATCH
1900     }
1901 
1902   if (d->block)
1903     {
1904       if (d->pspace == current_program_space)
1905 	within_current_scope = contained_in (get_selected_block (0), d->block);
1906       else
1907 	within_current_scope = 0;
1908     }
1909   else
1910     within_current_scope = 1;
1911   if (!within_current_scope)
1912     return;
1913 
1914   scoped_restore save_display_number
1915     = make_scoped_restore (&current_display_number, d->number);
1916 
1917   annotate_display_begin ();
1918   printf_filtered ("%d", d->number);
1919   annotate_display_number_end ();
1920   printf_filtered (": ");
1921   if (d->format.size)
1922     {
1923 
1924       annotate_display_format ();
1925 
1926       printf_filtered ("x/");
1927       if (d->format.count != 1)
1928 	printf_filtered ("%d", d->format.count);
1929       printf_filtered ("%c", d->format.format);
1930       if (d->format.format != 'i' && d->format.format != 's')
1931 	printf_filtered ("%c", d->format.size);
1932       printf_filtered (" ");
1933 
1934       annotate_display_expression ();
1935 
1936       puts_filtered (d->exp_string);
1937       annotate_display_expression_end ();
1938 
1939       if (d->format.count != 1 || d->format.format == 'i')
1940 	printf_filtered ("\n");
1941       else
1942 	printf_filtered ("  ");
1943 
1944       annotate_display_value ();
1945 
1946       TRY
1947         {
1948 	  struct value *val;
1949 	  CORE_ADDR addr;
1950 
1951 	  val = evaluate_expression (d->exp.get ());
1952 	  addr = value_as_address (val);
1953 	  if (d->format.format == 'i')
1954 	    addr = gdbarch_addr_bits_remove (d->exp->gdbarch, addr);
1955 	  do_examine (d->format, d->exp->gdbarch, addr);
1956 	}
1957       CATCH (ex, RETURN_MASK_ERROR)
1958 	{
1959 	  fprintf_filtered (gdb_stdout, _("<error: %s>\n"), ex.message);
1960 	}
1961       END_CATCH
1962     }
1963   else
1964     {
1965       struct value_print_options opts;
1966 
1967       annotate_display_format ();
1968 
1969       if (d->format.format)
1970 	printf_filtered ("/%c ", d->format.format);
1971 
1972       annotate_display_expression ();
1973 
1974       puts_filtered (d->exp_string);
1975       annotate_display_expression_end ();
1976 
1977       printf_filtered (" = ");
1978 
1979       annotate_display_expression ();
1980 
1981       get_formatted_print_options (&opts, d->format.format);
1982       opts.raw = d->format.raw;
1983 
1984       TRY
1985         {
1986 	  struct value *val;
1987 
1988 	  val = evaluate_expression (d->exp.get ());
1989 	  print_formatted (val, d->format.size, &opts, gdb_stdout);
1990 	}
1991       CATCH (ex, RETURN_MASK_ERROR)
1992 	{
1993 	  fprintf_filtered (gdb_stdout, _("<error: %s>"), ex.message);
1994 	}
1995       END_CATCH
1996 
1997       printf_filtered ("\n");
1998     }
1999 
2000   annotate_display_end ();
2001 
2002   gdb_flush (gdb_stdout);
2003 }
2004 
2005 /* Display all of the values on the auto-display chain which can be
2006    evaluated in the current scope.  */
2007 
2008 void
2009 do_displays (void)
2010 {
2011   struct display *d;
2012 
2013   for (d = display_chain; d; d = d->next)
2014     do_one_display (d);
2015 }
2016 
2017 /* Delete the auto-display which we were in the process of displaying.
2018    This is done when there is an error or a signal.  */
2019 
2020 void
2021 disable_display (int num)
2022 {
2023   struct display *d;
2024 
2025   for (d = display_chain; d; d = d->next)
2026     if (d->number == num)
2027       {
2028 	d->enabled_p = 0;
2029 	return;
2030       }
2031   printf_unfiltered (_("No display number %d.\n"), num);
2032 }
2033 
2034 void
2035 disable_current_display (void)
2036 {
2037   if (current_display_number >= 0)
2038     {
2039       disable_display (current_display_number);
2040       fprintf_unfiltered (gdb_stderr,
2041 			  _("Disabling display %d to "
2042 			    "avoid infinite recursion.\n"),
2043 			  current_display_number);
2044     }
2045   current_display_number = -1;
2046 }
2047 
2048 static void
2049 info_display_command (const char *ignore, int from_tty)
2050 {
2051   struct display *d;
2052 
2053   if (!display_chain)
2054     printf_unfiltered (_("There are no auto-display expressions now.\n"));
2055   else
2056     printf_filtered (_("Auto-display expressions now in effect:\n\
2057 Num Enb Expression\n"));
2058 
2059   for (d = display_chain; d; d = d->next)
2060     {
2061       printf_filtered ("%d:   %c  ", d->number, "ny"[(int) d->enabled_p]);
2062       if (d->format.size)
2063 	printf_filtered ("/%d%c%c ", d->format.count, d->format.size,
2064 			 d->format.format);
2065       else if (d->format.format)
2066 	printf_filtered ("/%c ", d->format.format);
2067       puts_filtered (d->exp_string);
2068       if (d->block && !contained_in (get_selected_block (0), d->block))
2069 	printf_filtered (_(" (cannot be evaluated in the current context)"));
2070       printf_filtered ("\n");
2071       gdb_flush (gdb_stdout);
2072     }
2073 }
2074 
2075 /* Callback fo map_display_numbers, that enables or disables the
2076    passed in display D.  */
2077 
2078 static void
2079 do_enable_disable_display (struct display *d, void *data)
2080 {
2081   d->enabled_p = *(int *) data;
2082 }
2083 
2084 /* Implamentation of both the "disable display" and "enable display"
2085    commands.  ENABLE decides what to do.  */
2086 
2087 static void
2088 enable_disable_display_command (const char *args, int from_tty, int enable)
2089 {
2090   if (args == NULL)
2091     {
2092       struct display *d;
2093 
2094       ALL_DISPLAYS (d)
2095 	d->enabled_p = enable;
2096       return;
2097     }
2098 
2099   map_display_numbers (args, do_enable_disable_display, &enable);
2100 }
2101 
2102 /* The "enable display" command.  */
2103 
2104 static void
2105 enable_display_command (const char *args, int from_tty)
2106 {
2107   enable_disable_display_command (args, from_tty, 1);
2108 }
2109 
2110 /* The "disable display" command.  */
2111 
2112 static void
2113 disable_display_command (const char *args, int from_tty)
2114 {
2115   enable_disable_display_command (args, from_tty, 0);
2116 }
2117 
2118 /* display_chain items point to blocks and expressions.  Some expressions in
2119    turn may point to symbols.
2120    Both symbols and blocks are obstack_alloc'd on objfile_stack, and are
2121    obstack_free'd when a shared library is unloaded.
2122    Clear pointers that are about to become dangling.
2123    Both .exp and .block fields will be restored next time we need to display
2124    an item by re-parsing .exp_string field in the new execution context.  */
2125 
2126 static void
2127 clear_dangling_display_expressions (struct objfile *objfile)
2128 {
2129   struct display *d;
2130   struct program_space *pspace;
2131 
2132   /* With no symbol file we cannot have a block or expression from it.  */
2133   if (objfile == NULL)
2134     return;
2135   pspace = objfile->pspace;
2136   if (objfile->separate_debug_objfile_backlink)
2137     {
2138       objfile = objfile->separate_debug_objfile_backlink;
2139       gdb_assert (objfile->pspace == pspace);
2140     }
2141 
2142   for (d = display_chain; d != NULL; d = d->next)
2143     {
2144       if (d->pspace != pspace)
2145 	continue;
2146 
2147       if (lookup_objfile_from_block (d->block) == objfile
2148 	  || (d->exp != NULL && exp_uses_objfile (d->exp.get (), objfile)))
2149       {
2150 	d->exp.reset ();
2151 	d->block = NULL;
2152       }
2153     }
2154 }
2155 
2156 
2157 /* Print the value in stack frame FRAME of a variable specified by a
2158    struct symbol.  NAME is the name to print; if NULL then VAR's print
2159    name will be used.  STREAM is the ui_file on which to print the
2160    value.  INDENT specifies the number of indent levels to print
2161    before printing the variable name.
2162 
2163    This function invalidates FRAME.  */
2164 
2165 void
2166 print_variable_and_value (const char *name, struct symbol *var,
2167 			  struct frame_info *frame,
2168 			  struct ui_file *stream, int indent)
2169 {
2170 
2171   if (!name)
2172     name = SYMBOL_PRINT_NAME (var);
2173 
2174   fputs_filtered (n_spaces (2 * indent), stream);
2175   fputs_styled (name, variable_name_style.style (), stream);
2176   fputs_filtered (" = ", stream);
2177 
2178   TRY
2179     {
2180       struct value *val;
2181       struct value_print_options opts;
2182 
2183       /* READ_VAR_VALUE needs a block in order to deal with non-local
2184 	 references (i.e. to handle nested functions).  In this context, we
2185 	 print variables that are local to this frame, so we can avoid passing
2186 	 a block to it.  */
2187       val = read_var_value (var, NULL, frame);
2188       get_user_print_options (&opts);
2189       opts.deref_ref = 1;
2190       common_val_print (val, stream, indent, &opts, current_language);
2191 
2192       /* common_val_print invalidates FRAME when a pretty printer calls inferior
2193 	 function.  */
2194       frame = NULL;
2195     }
2196   CATCH (except, RETURN_MASK_ERROR)
2197     {
2198       fprintf_filtered(stream, "<error reading variable %s (%s)>", name,
2199 		       except.message);
2200     }
2201   END_CATCH
2202 
2203   fprintf_filtered (stream, "\n");
2204 }
2205 
2206 /* Subroutine of ui_printf to simplify it.
2207    Print VALUE to STREAM using FORMAT.
2208    VALUE is a C-style string on the target.  */
2209 
2210 static void
2211 printf_c_string (struct ui_file *stream, const char *format,
2212 		 struct value *value)
2213 {
2214   gdb_byte *str;
2215   CORE_ADDR tem;
2216   int j;
2217 
2218   tem = value_as_address (value);
2219   if (tem == 0)
2220     {
2221       DIAGNOSTIC_PUSH
2222       DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2223       fprintf_filtered (stream, format, "(null)");
2224       DIAGNOSTIC_POP
2225       return;
2226     }
2227 
2228   /* This is a %s argument.  Find the length of the string.  */
2229   for (j = 0;; j++)
2230     {
2231       gdb_byte c;
2232 
2233       QUIT;
2234       read_memory (tem + j, &c, 1);
2235       if (c == 0)
2236 	break;
2237     }
2238 
2239   /* Copy the string contents into a string inside GDB.  */
2240   str = (gdb_byte *) alloca (j + 1);
2241   if (j != 0)
2242     read_memory (tem, str, j);
2243   str[j] = 0;
2244 
2245   DIAGNOSTIC_PUSH
2246   DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2247   fprintf_filtered (stream, format, (char *) str);
2248   DIAGNOSTIC_POP
2249 }
2250 
2251 /* Subroutine of ui_printf to simplify it.
2252    Print VALUE to STREAM using FORMAT.
2253    VALUE is a wide C-style string on the target.  */
2254 
2255 static void
2256 printf_wide_c_string (struct ui_file *stream, const char *format,
2257 		      struct value *value)
2258 {
2259   gdb_byte *str;
2260   CORE_ADDR tem;
2261   int j;
2262   struct gdbarch *gdbarch = get_type_arch (value_type (value));
2263   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
2264   struct type *wctype = lookup_typename (current_language, gdbarch,
2265 					 "wchar_t", NULL, 0);
2266   int wcwidth = TYPE_LENGTH (wctype);
2267   gdb_byte *buf = (gdb_byte *) alloca (wcwidth);
2268 
2269   tem = value_as_address (value);
2270   if (tem == 0)
2271     {
2272       DIAGNOSTIC_PUSH
2273       DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2274       fprintf_filtered (stream, format, "(null)");
2275       DIAGNOSTIC_POP
2276       return;
2277     }
2278 
2279   /* This is a %s argument.  Find the length of the string.  */
2280   for (j = 0;; j += wcwidth)
2281     {
2282       QUIT;
2283       read_memory (tem + j, buf, wcwidth);
2284       if (extract_unsigned_integer (buf, wcwidth, byte_order) == 0)
2285 	break;
2286     }
2287 
2288   /* Copy the string contents into a string inside GDB.  */
2289   str = (gdb_byte *) alloca (j + wcwidth);
2290   if (j != 0)
2291     read_memory (tem, str, j);
2292   memset (&str[j], 0, wcwidth);
2293 
2294   auto_obstack output;
2295 
2296   convert_between_encodings (target_wide_charset (gdbarch),
2297 			     host_charset (),
2298 			     str, j, wcwidth,
2299 			     &output, translit_char);
2300   obstack_grow_str0 (&output, "");
2301 
2302   DIAGNOSTIC_PUSH
2303   DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2304   fprintf_filtered (stream, format, obstack_base (&output));
2305   DIAGNOSTIC_POP
2306 }
2307 
2308 /* Subroutine of ui_printf to simplify it.
2309    Print VALUE, a floating point value, to STREAM using FORMAT.  */
2310 
2311 static void
2312 printf_floating (struct ui_file *stream, const char *format,
2313 		 struct value *value, enum argclass argclass)
2314 {
2315   /* Parameter data.  */
2316   struct type *param_type = value_type (value);
2317   struct gdbarch *gdbarch = get_type_arch (param_type);
2318 
2319   /* Determine target type corresponding to the format string.  */
2320   struct type *fmt_type;
2321   switch (argclass)
2322     {
2323       case double_arg:
2324 	fmt_type = builtin_type (gdbarch)->builtin_double;
2325 	break;
2326       case long_double_arg:
2327 	fmt_type = builtin_type (gdbarch)->builtin_long_double;
2328 	break;
2329       case dec32float_arg:
2330 	fmt_type = builtin_type (gdbarch)->builtin_decfloat;
2331 	break;
2332       case dec64float_arg:
2333 	fmt_type = builtin_type (gdbarch)->builtin_decdouble;
2334 	break;
2335       case dec128float_arg:
2336 	fmt_type = builtin_type (gdbarch)->builtin_declong;
2337 	break;
2338       default:
2339 	gdb_assert_not_reached ("unexpected argument class");
2340     }
2341 
2342   /* To match the traditional GDB behavior, the conversion is
2343      done differently depending on the type of the parameter:
2344 
2345      - if the parameter has floating-point type, it's value
2346        is converted to the target type;
2347 
2348      - otherwise, if the parameter has a type that is of the
2349        same size as a built-in floating-point type, the value
2350        bytes are interpreted as if they were of that type, and
2351        then converted to the target type (this is not done for
2352        decimal floating-point argument classes);
2353 
2354      - otherwise, if the source value has an integer value,
2355        it's value is converted to the target type;
2356 
2357      - otherwise, an error is raised.
2358 
2359      In either case, the result of the conversion is a byte buffer
2360      formatted in the target format for the target type.  */
2361 
2362   if (TYPE_CODE (fmt_type) == TYPE_CODE_FLT)
2363     {
2364       param_type = float_type_from_length (param_type);
2365       if (param_type != value_type (value))
2366 	value = value_from_contents (param_type, value_contents (value));
2367     }
2368 
2369   value = value_cast (fmt_type, value);
2370 
2371   /* Convert the value to a string and print it.  */
2372   std::string str
2373     = target_float_to_string (value_contents (value), fmt_type, format);
2374   fputs_filtered (str.c_str (), stream);
2375 }
2376 
2377 /* Subroutine of ui_printf to simplify it.
2378    Print VALUE, a target pointer, to STREAM using FORMAT.  */
2379 
2380 static void
2381 printf_pointer (struct ui_file *stream, const char *format,
2382 		struct value *value)
2383 {
2384   /* We avoid the host's %p because pointers are too
2385      likely to be the wrong size.  The only interesting
2386      modifier for %p is a width; extract that, and then
2387      handle %p as glibc would: %#x or a literal "(nil)".  */
2388 
2389   const char *p;
2390   char *fmt, *fmt_p;
2391 #ifdef PRINTF_HAS_LONG_LONG
2392   long long val = value_as_long (value);
2393 #else
2394   long val = value_as_long (value);
2395 #endif
2396 
2397   fmt = (char *) alloca (strlen (format) + 5);
2398 
2399   /* Copy up to the leading %.  */
2400   p = format;
2401   fmt_p = fmt;
2402   while (*p)
2403     {
2404       int is_percent = (*p == '%');
2405 
2406       *fmt_p++ = *p++;
2407       if (is_percent)
2408 	{
2409 	  if (*p == '%')
2410 	    *fmt_p++ = *p++;
2411 	  else
2412 	    break;
2413 	}
2414     }
2415 
2416   if (val != 0)
2417     *fmt_p++ = '#';
2418 
2419   /* Copy any width or flags.  Only the "-" flag is valid for pointers
2420      -- see the format_pieces constructor.  */
2421   while (*p == '-' || (*p >= '0' && *p < '9'))
2422     *fmt_p++ = *p++;
2423 
2424   gdb_assert (*p == 'p' && *(p + 1) == '\0');
2425   if (val != 0)
2426     {
2427 #ifdef PRINTF_HAS_LONG_LONG
2428       *fmt_p++ = 'l';
2429 #endif
2430       *fmt_p++ = 'l';
2431       *fmt_p++ = 'x';
2432       *fmt_p++ = '\0';
2433       DIAGNOSTIC_PUSH
2434       DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2435       fprintf_filtered (stream, fmt, val);
2436       DIAGNOSTIC_POP
2437     }
2438   else
2439     {
2440       *fmt_p++ = 's';
2441       *fmt_p++ = '\0';
2442       DIAGNOSTIC_PUSH
2443       DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2444       fprintf_filtered (stream, fmt, "(nil)");
2445       DIAGNOSTIC_POP
2446     }
2447 }
2448 
2449 /* printf "printf format string" ARG to STREAM.  */
2450 
2451 static void
2452 ui_printf (const char *arg, struct ui_file *stream)
2453 {
2454   const char *s = arg;
2455   std::vector<struct value *> val_args;
2456 
2457   if (s == 0)
2458     error_no_arg (_("format-control string and values to print"));
2459 
2460   s = skip_spaces (s);
2461 
2462   /* A format string should follow, enveloped in double quotes.  */
2463   if (*s++ != '"')
2464     error (_("Bad format string, missing '\"'."));
2465 
2466   format_pieces fpieces (&s);
2467 
2468   if (*s++ != '"')
2469     error (_("Bad format string, non-terminated '\"'."));
2470 
2471   s = skip_spaces (s);
2472 
2473   if (*s != ',' && *s != 0)
2474     error (_("Invalid argument syntax"));
2475 
2476   if (*s == ',')
2477     s++;
2478   s = skip_spaces (s);
2479 
2480   {
2481     int nargs_wanted;
2482     int i;
2483     const char *current_substring;
2484 
2485     nargs_wanted = 0;
2486     for (auto &&piece : fpieces)
2487       if (piece.argclass != literal_piece)
2488 	++nargs_wanted;
2489 
2490     /* Now, parse all arguments and evaluate them.
2491        Store the VALUEs in VAL_ARGS.  */
2492 
2493     while (*s != '\0')
2494       {
2495 	const char *s1;
2496 
2497 	s1 = s;
2498 	val_args.push_back (parse_to_comma_and_eval (&s1));
2499 
2500 	s = s1;
2501 	if (*s == ',')
2502 	  s++;
2503       }
2504 
2505     if (val_args.size () != nargs_wanted)
2506       error (_("Wrong number of arguments for specified format-string"));
2507 
2508     /* Now actually print them.  */
2509     i = 0;
2510     for (auto &&piece : fpieces)
2511       {
2512 	current_substring = piece.string;
2513 	switch (piece.argclass)
2514 	  {
2515 	  case string_arg:
2516 	    printf_c_string (stream, current_substring, val_args[i]);
2517 	    break;
2518 	  case wide_string_arg:
2519 	    printf_wide_c_string (stream, current_substring, val_args[i]);
2520 	    break;
2521 	  case wide_char_arg:
2522 	    {
2523 	      struct gdbarch *gdbarch
2524 		= get_type_arch (value_type (val_args[i]));
2525 	      struct type *wctype = lookup_typename (current_language, gdbarch,
2526 						     "wchar_t", NULL, 0);
2527 	      struct type *valtype;
2528 	      const gdb_byte *bytes;
2529 
2530 	      valtype = value_type (val_args[i]);
2531 	      if (TYPE_LENGTH (valtype) != TYPE_LENGTH (wctype)
2532 		  || TYPE_CODE (valtype) != TYPE_CODE_INT)
2533 		error (_("expected wchar_t argument for %%lc"));
2534 
2535 	      bytes = value_contents (val_args[i]);
2536 
2537 	      auto_obstack output;
2538 
2539 	      convert_between_encodings (target_wide_charset (gdbarch),
2540 					 host_charset (),
2541 					 bytes, TYPE_LENGTH (valtype),
2542 					 TYPE_LENGTH (valtype),
2543 					 &output, translit_char);
2544 	      obstack_grow_str0 (&output, "");
2545 
2546 	      DIAGNOSTIC_PUSH
2547 	      DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2548 	      fprintf_filtered (stream, current_substring,
2549                                 obstack_base (&output));
2550 	      DIAGNOSTIC_POP
2551 	    }
2552 	    break;
2553 	  case long_long_arg:
2554 #ifdef PRINTF_HAS_LONG_LONG
2555 	    {
2556 	      long long val = value_as_long (val_args[i]);
2557 
2558 	      DIAGNOSTIC_PUSH
2559 	      DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2560               fprintf_filtered (stream, current_substring, val);
2561 	      DIAGNOSTIC_POP
2562 	      break;
2563 	    }
2564 #else
2565 	    error (_("long long not supported in printf"));
2566 #endif
2567 	  case int_arg:
2568 	    {
2569 	      int val = value_as_long (val_args[i]);
2570 
2571 	      DIAGNOSTIC_PUSH
2572 	      DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2573               fprintf_filtered (stream, current_substring, val);
2574 	      DIAGNOSTIC_POP
2575 	      break;
2576 	    }
2577 	  case long_arg:
2578 	    {
2579 	      long val = value_as_long (val_args[i]);
2580 
2581 	      DIAGNOSTIC_PUSH
2582 	      DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2583               fprintf_filtered (stream, current_substring, val);
2584 	      DIAGNOSTIC_POP
2585 	      break;
2586 	    }
2587 	  /* Handles floating-point values.  */
2588 	  case double_arg:
2589 	  case long_double_arg:
2590 	  case dec32float_arg:
2591 	  case dec64float_arg:
2592 	  case dec128float_arg:
2593 	    printf_floating (stream, current_substring, val_args[i],
2594 			     piece.argclass);
2595 	    break;
2596 	  case ptr_arg:
2597 	    printf_pointer (stream, current_substring, val_args[i]);
2598 	    break;
2599 	  case literal_piece:
2600 	    /* Print a portion of the format string that has no
2601 	       directives.  Note that this will not include any
2602 	       ordinary %-specs, but it might include "%%".  That is
2603 	       why we use printf_filtered and not puts_filtered here.
2604 	       Also, we pass a dummy argument because some platforms
2605 	       have modified GCC to include -Wformat-security by
2606 	       default, which will warn here if there is no
2607 	       argument.  */
2608 	    DIAGNOSTIC_PUSH
2609 	    DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
2610 	    fprintf_filtered (stream, current_substring, 0);
2611 	    DIAGNOSTIC_POP
2612 	    break;
2613 	  default:
2614 	    internal_error (__FILE__, __LINE__,
2615 			    _("failed internal consistency check"));
2616 	  }
2617 	/* Maybe advance to the next argument.  */
2618 	if (piece.argclass != literal_piece)
2619 	  ++i;
2620       }
2621   }
2622 }
2623 
2624 /* Implement the "printf" command.  */
2625 
2626 static void
2627 printf_command (const char *arg, int from_tty)
2628 {
2629   ui_printf (arg, gdb_stdout);
2630   reset_terminal_style (gdb_stdout);
2631   wrap_here ("");
2632   gdb_flush (gdb_stdout);
2633 }
2634 
2635 /* Implement the "eval" command.  */
2636 
2637 static void
2638 eval_command (const char *arg, int from_tty)
2639 {
2640   string_file stb;
2641 
2642   ui_printf (arg, &stb);
2643 
2644   std::string expanded = insert_user_defined_cmd_args (stb.c_str ());
2645 
2646   execute_command (expanded.c_str (), from_tty);
2647 }
2648 
2649 void
2650 _initialize_printcmd (void)
2651 {
2652   struct cmd_list_element *c;
2653 
2654   current_display_number = -1;
2655 
2656   gdb::observers::free_objfile.attach (clear_dangling_display_expressions);
2657 
2658   add_info ("address", info_address_command,
2659 	    _("Describe where symbol SYM is stored."));
2660 
2661   add_info ("symbol", info_symbol_command, _("\
2662 Describe what symbol is at location ADDR.\n\
2663 Only for symbols with fixed locations (global or static scope)."));
2664 
2665   add_com ("x", class_vars, x_command, _("\
2666 Examine memory: x/FMT ADDRESS.\n\
2667 ADDRESS is an expression for the memory address to examine.\n\
2668 FMT is a repeat count followed by a format letter and a size letter.\n\
2669 Format letters are o(octal), x(hex), d(decimal), u(unsigned decimal),\n\
2670   t(binary), f(float), a(address), i(instruction), c(char), s(string)\n\
2671   and z(hex, zero padded on the left).\n\
2672 Size letters are b(byte), h(halfword), w(word), g(giant, 8 bytes).\n\
2673 The specified number of objects of the specified size are printed\n\
2674 according to the format.  If a negative number is specified, memory is\n\
2675 examined backward from the address.\n\n\
2676 Defaults for format and size letters are those previously used.\n\
2677 Default count is 1.  Default address is following last thing printed\n\
2678 with this command or \"print\"."));
2679 
2680 #if 0
2681   add_com ("whereis", class_vars, whereis_command,
2682 	   _("Print line number and file of definition of variable."));
2683 #endif
2684 
2685   add_info ("display", info_display_command, _("\
2686 Expressions to display when program stops, with code numbers."));
2687 
2688   add_cmd ("undisplay", class_vars, undisplay_command, _("\
2689 Cancel some expressions to be displayed when program stops.\n\
2690 Arguments are the code numbers of the expressions to stop displaying.\n\
2691 No argument means cancel all automatic-display expressions.\n\
2692 \"delete display\" has the same effect as this command.\n\
2693 Do \"info display\" to see current list of code numbers."),
2694 	   &cmdlist);
2695 
2696   add_com ("display", class_vars, display_command, _("\
2697 Print value of expression EXP each time the program stops.\n\
2698 /FMT may be used before EXP as in the \"print\" command.\n\
2699 /FMT \"i\" or \"s\" or including a size-letter is allowed,\n\
2700 as in the \"x\" command, and then EXP is used to get the address to examine\n\
2701 and examining is done as in the \"x\" command.\n\n\
2702 With no argument, display all currently requested auto-display expressions.\n\
2703 Use \"undisplay\" to cancel display requests previously made."));
2704 
2705   add_cmd ("display", class_vars, enable_display_command, _("\
2706 Enable some expressions to be displayed when program stops.\n\
2707 Arguments are the code numbers of the expressions to resume displaying.\n\
2708 No argument means enable all automatic-display expressions.\n\
2709 Do \"info display\" to see current list of code numbers."), &enablelist);
2710 
2711   add_cmd ("display", class_vars, disable_display_command, _("\
2712 Disable some expressions to be displayed when program stops.\n\
2713 Arguments are the code numbers of the expressions to stop displaying.\n\
2714 No argument means disable all automatic-display expressions.\n\
2715 Do \"info display\" to see current list of code numbers."), &disablelist);
2716 
2717   add_cmd ("display", class_vars, undisplay_command, _("\
2718 Cancel some expressions to be displayed when program stops.\n\
2719 Arguments are the code numbers of the expressions to stop displaying.\n\
2720 No argument means cancel all automatic-display expressions.\n\
2721 Do \"info display\" to see current list of code numbers."), &deletelist);
2722 
2723   add_com ("printf", class_vars, printf_command, _("\
2724 Formatted printing, like the C \"printf\" function.\n\
2725 Usage: printf \"format string\", arg1, arg2, arg3, ..., argn\n\
2726 This supports most C printf format specifications, like %s, %d, etc."));
2727 
2728   add_com ("output", class_vars, output_command, _("\
2729 Like \"print\" but don't put in value history and don't print newline.\n\
2730 This is useful in user-defined commands."));
2731 
2732   add_prefix_cmd ("set", class_vars, set_command, _("\
2733 Evaluate expression EXP and assign result to variable VAR, using assignment\n\
2734 syntax appropriate for the current language (VAR = EXP or VAR := EXP for\n\
2735 example).  VAR may be a debugger \"convenience\" variable (names starting\n\
2736 with $), a register (a few standard names starting with $), or an actual\n\
2737 variable in the program being debugged.  EXP is any valid expression.\n\
2738 Use \"set variable\" for variables with names identical to set subcommands.\n\
2739 \n\
2740 With a subcommand, this command modifies parts of the gdb environment.\n\
2741 You can see these environment settings with the \"show\" command."),
2742 		  &setlist, "set ", 1, &cmdlist);
2743   if (dbx_commands)
2744     add_com ("assign", class_vars, set_command, _("\
2745 Evaluate expression EXP and assign result to variable VAR, using assignment\n\
2746 syntax appropriate for the current language (VAR = EXP or VAR := EXP for\n\
2747 example).  VAR may be a debugger \"convenience\" variable (names starting\n\
2748 with $), a register (a few standard names starting with $), or an actual\n\
2749 variable in the program being debugged.  EXP is any valid expression.\n\
2750 Use \"set variable\" for variables with names identical to set subcommands.\n\
2751 \nWith a subcommand, this command modifies parts of the gdb environment.\n\
2752 You can see these environment settings with the \"show\" command."));
2753 
2754   /* "call" is the same as "set", but handy for dbx users to call fns.  */
2755   c = add_com ("call", class_vars, call_command, _("\
2756 Call a function in the program.\n\
2757 The argument is the function name and arguments, in the notation of the\n\
2758 current working language.  The result is printed and saved in the value\n\
2759 history, if it is not void."));
2760   set_cmd_completer (c, expression_completer);
2761 
2762   add_cmd ("variable", class_vars, set_command, _("\
2763 Evaluate expression EXP and assign result to variable VAR, using assignment\n\
2764 syntax appropriate for the current language (VAR = EXP or VAR := EXP for\n\
2765 example).  VAR may be a debugger \"convenience\" variable (names starting\n\
2766 with $), a register (a few standard names starting with $), or an actual\n\
2767 variable in the program being debugged.  EXP is any valid expression.\n\
2768 This may usually be abbreviated to simply \"set\"."),
2769 	   &setlist);
2770   add_alias_cmd ("var", "variable", class_vars, 0, &setlist);
2771 
2772   c = add_com ("print", class_vars, print_command, _("\
2773 Print value of expression EXP.\n\
2774 Variables accessible are those of the lexical environment of the selected\n\
2775 stack frame, plus all those whose scope is global or an entire file.\n\
2776 \n\
2777 $NUM gets previous value number NUM.  $ and $$ are the last two values.\n\
2778 $$NUM refers to NUM'th value back from the last one.\n\
2779 Names starting with $ refer to registers (with the values they would have\n\
2780 if the program were to return to the stack frame now selected, restoring\n\
2781 all registers saved by frames farther in) or else to debugger\n\
2782 \"convenience\" variables (any such name not a known register).\n\
2783 Use assignment expressions to give values to convenience variables.\n\
2784 \n\
2785 {TYPE}ADREXP refers to a datum of data type TYPE, located at address ADREXP.\n\
2786 @ is a binary operator for treating consecutive data objects\n\
2787 anywhere in memory as an array.  FOO@NUM gives an array whose first\n\
2788 element is FOO, whose second element is stored in the space following\n\
2789 where FOO is stored, etc.  FOO must be an expression whose value\n\
2790 resides in memory.\n\
2791 \n\
2792 EXP may be preceded with /FMT, where FMT is a format letter\n\
2793 but no count or size letter (see \"x\" command)."));
2794   set_cmd_completer (c, expression_completer);
2795   add_com_alias ("p", "print", class_vars, 1);
2796   add_com_alias ("inspect", "print", class_vars, 1);
2797 
2798   add_setshow_uinteger_cmd ("max-symbolic-offset", no_class,
2799 			    &max_symbolic_offset, _("\
2800 Set the largest offset that will be printed in <symbol+1234> form."), _("\
2801 Show the largest offset that will be printed in <symbol+1234> form."), _("\
2802 Tell GDB to only display the symbolic form of an address if the\n\
2803 offset between the closest earlier symbol and the address is less than\n\
2804 the specified maximum offset.  The default is \"unlimited\", which tells GDB\n\
2805 to always print the symbolic form of an address if any symbol precedes\n\
2806 it.  Zero is equivalent to \"unlimited\"."),
2807 			    NULL,
2808 			    show_max_symbolic_offset,
2809 			    &setprintlist, &showprintlist);
2810   add_setshow_boolean_cmd ("symbol-filename", no_class,
2811 			   &print_symbol_filename, _("\
2812 Set printing of source filename and line number with <symbol>."), _("\
2813 Show printing of source filename and line number with <symbol>."), NULL,
2814 			   NULL,
2815 			   show_print_symbol_filename,
2816 			   &setprintlist, &showprintlist);
2817 
2818   add_com ("eval", no_class, eval_command, _("\
2819 Convert \"printf format string\", arg1, arg2, arg3, ..., argn to\n\
2820 a command line, and call it."));
2821 }
2822