xref: /openbsd-src/gnu/usr.bin/binutils/gdb/c-valprint.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /* Support for printing C values for GDB, the GNU debugger.
2    Copyright 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996
3              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 2 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, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
20 
21 #include "defs.h"
22 #include "symtab.h"
23 #include "gdbtypes.h"
24 #include "expression.h"
25 #include "value.h"
26 #include "demangle.h"
27 #include "valprint.h"
28 #include "language.h"
29 #include "c-lang.h"
30 
31 
32 /* Print data of type TYPE located at VALADDR (within GDB), which came from
33    the inferior at address ADDRESS, onto stdio stream STREAM according to
34    FORMAT (a letter or 0 for natural format).  The data at VALADDR is in
35    target byte order.
36 
37    If the data are a string pointer, returns the number of string characters
38    printed.
39 
40    If DEREF_REF is nonzero, then dereference references, otherwise just print
41    them like pointers.
42 
43    The PRETTY parameter controls prettyprinting.  */
44 
45 int
46 c_val_print (type, valaddr, address, stream, format, deref_ref, recurse,
47 	     pretty)
48      struct type *type;
49      char *valaddr;
50      CORE_ADDR address;
51      GDB_FILE *stream;
52      int format;
53      int deref_ref;
54      int recurse;
55      enum val_prettyprint pretty;
56 {
57   register unsigned int i = 0;		/* Number of characters printed */
58   unsigned len;
59   struct type *elttype;
60   unsigned eltlen;
61   LONGEST val;
62   CORE_ADDR addr;
63 
64   CHECK_TYPEDEF (type);
65   switch (TYPE_CODE (type))
66     {
67     case TYPE_CODE_ARRAY:
68       if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
69 	{
70 	  elttype = check_typedef (TYPE_TARGET_TYPE (type));
71 	  eltlen = TYPE_LENGTH (elttype);
72 	  len = TYPE_LENGTH (type) / eltlen;
73 	  if (prettyprint_arrays)
74 	    {
75 	      print_spaces_filtered (2 + 2 * recurse, stream);
76 	    }
77 	  /* For an array of chars, print with string syntax.  */
78 	  if (eltlen == 1 &&
79 	      ((TYPE_CODE (elttype) == TYPE_CODE_INT)
80 	       || ((current_language->la_language == language_m2)
81 		   && (TYPE_CODE (elttype) == TYPE_CODE_CHAR)))
82 	      && (format == 0 || format == 's'))
83 	    {
84 	      /* If requested, look for the first null char and only print
85 		 elements up to it.  */
86 	      if (stop_print_at_null)
87 		{
88 		  int temp_len;
89 
90 		  /* Look for a NULL char. */
91 		  for (temp_len = 0;
92 		       valaddr[temp_len]
93 		       && temp_len < len && temp_len < print_max;
94 		       temp_len++);
95 		  len = temp_len;
96 		}
97 
98 	      LA_PRINT_STRING (stream, valaddr, len, 0);
99 	      i = len;
100 	    }
101 	  else
102 	    {
103 	      fprintf_filtered (stream, "{");
104 	      /* If this is a virtual function table, print the 0th
105 		 entry specially, and the rest of the members normally.  */
106 	      if (cp_is_vtbl_ptr_type (elttype))
107 		{
108 		  i = 1;
109 		  fprintf_filtered (stream, "%d vtable entries", len - 1);
110 		}
111 	      else
112 		{
113 		  i = 0;
114 		}
115 	      val_print_array_elements (type, valaddr, address, stream,
116 					format, deref_ref, recurse, pretty, i);
117 	      fprintf_filtered (stream, "}");
118 	    }
119 	  break;
120 	}
121       /* Array of unspecified length: treat like pointer to first elt.  */
122       addr = address;
123       goto print_unpacked_pointer;
124 
125     case TYPE_CODE_PTR:
126       if (format && format != 's')
127 	{
128 	  print_scalar_formatted (valaddr, type, format, 0, stream);
129 	  break;
130 	}
131       if (vtblprint && cp_is_vtbl_ptr_type(type))
132 	{
133           /* Print the unmangled name if desired.  */
134 	  /* Print vtable entry - we only get here if we ARE using
135 	     -fvtable_thunks.  (Otherwise, look under TYPE_CODE_STRUCT.) */
136 	  print_address_demangle(extract_address (valaddr, TYPE_LENGTH (type)),
137 				 stream, demangle);
138 	  break;
139 	}
140       elttype = check_typedef (TYPE_TARGET_TYPE (type));
141       if (TYPE_CODE (elttype) == TYPE_CODE_METHOD)
142 	{
143 	  cp_print_class_method (valaddr, type, stream);
144 	}
145       else if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
146 	{
147 	  cp_print_class_member (valaddr,
148 				 TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
149 				 stream, "&");
150 	}
151       else
152 	{
153 	  addr = unpack_pointer (type, valaddr);
154 	print_unpacked_pointer:
155           elttype = check_typedef (TYPE_TARGET_TYPE (type));
156 
157 	  if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
158 	    {
159 	      /* Try to print what function it points to.  */
160 	      print_address_demangle (addr, stream, demangle);
161 	      /* Return value is irrelevant except for string pointers.  */
162 	      return (0);
163 	    }
164 
165 	  if (addressprint && format != 's')
166 	    {
167 	      print_address_numeric (addr, 1, stream);
168 	    }
169 
170 	  /* For a pointer to char or unsigned char, also print the string
171 	     pointed to, unless pointer is null.  */
172 	  if (TYPE_LENGTH (elttype) == 1
173 	      && TYPE_CODE (elttype) == TYPE_CODE_INT
174 	      && (format == 0 || format == 's')
175 	      && addr != 0)
176 	    {
177 	      i = val_print_string (addr, 0, stream);
178 	    }
179 	  else if (cp_is_vtbl_member(type))
180   	    {
181 	      /* print vtbl's nicely */
182 	      CORE_ADDR vt_address = unpack_pointer (type, valaddr);
183 
184 	      struct minimal_symbol *msymbol =
185 		lookup_minimal_symbol_by_pc (vt_address);
186 	      if ((msymbol != NULL) &&
187 		  (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
188 		{
189 		  fputs_filtered (" <", stream);
190 		  fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
191 		  fputs_filtered (">", stream);
192 		}
193 	      if (vt_address && vtblprint)
194 	        {
195 		  value_ptr vt_val;
196 	          struct symbol *wsym = (struct symbol *)NULL;
197 	          struct type *wtype;
198 		  struct symtab *s;
199 		  struct block *block = (struct block *)NULL;
200 		  int is_this_fld;
201 
202 		  if (msymbol != NULL)
203               	    wsym = lookup_symbol (SYMBOL_NAME(msymbol), block,
204 				VAR_NAMESPACE, &is_this_fld, &s);
205 
206 		  if (wsym)
207 		    {
208 	              wtype = SYMBOL_TYPE(wsym);
209 		    }
210 		  else
211 		    {
212 		      wtype = TYPE_TARGET_TYPE(type);
213 		    }
214 		  vt_val = value_at (wtype, vt_address);
215 		  val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
216 			     VALUE_ADDRESS (vt_val), stream, format,
217 			     deref_ref, recurse + 1, pretty);
218 		  if (pretty)
219 		    {
220 		      fprintf_filtered (stream, "\n");
221 		      print_spaces_filtered (2 + 2 * recurse, stream);
222 		    }
223 	        }
224 	      }
225 
226 	  /* Return number of characters printed, including the terminating
227 	     '\0' if we reached the end.  val_print_string takes care including
228 	     the terminating '\0' if necessary.  */
229 	  return i;
230 	}
231       break;
232 
233     case TYPE_CODE_MEMBER:
234       error ("not implemented: member type in c_val_print");
235       break;
236 
237     case TYPE_CODE_REF:
238       elttype = check_typedef (TYPE_TARGET_TYPE (type));
239       if (TYPE_CODE (elttype) == TYPE_CODE_MEMBER)
240         {
241 	  cp_print_class_member (valaddr,
242 				 TYPE_DOMAIN_TYPE (elttype),
243 				 stream, "");
244 	  break;
245 	}
246       if (addressprint)
247         {
248 	  fprintf_filtered (stream, "@");
249 	  print_address_numeric
250 	    (extract_address (valaddr,
251 			      TARGET_PTR_BIT / HOST_CHAR_BIT), 1, stream);
252 	  if (deref_ref)
253 	    fputs_filtered (": ", stream);
254         }
255       /* De-reference the reference.  */
256       if (deref_ref)
257 	{
258 	  if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
259 	    {
260 	      value_ptr deref_val =
261 		value_at
262 		  (TYPE_TARGET_TYPE (type),
263 		   unpack_pointer (lookup_pointer_type (builtin_type_void),
264 				   valaddr));
265 	      val_print (VALUE_TYPE (deref_val),
266 			 VALUE_CONTENTS (deref_val),
267 			 VALUE_ADDRESS (deref_val), stream, format,
268 			 deref_ref, recurse + 1, pretty);
269 	    }
270 	  else
271 	    fputs_filtered ("???", stream);
272 	}
273       break;
274 
275     case TYPE_CODE_UNION:
276       if (recurse && !unionprint)
277 	{
278 	  fprintf_filtered (stream, "{...}");
279 	  break;
280 	}
281       /* Fall through.  */
282     case TYPE_CODE_STRUCT:
283       if (vtblprint && cp_is_vtbl_ptr_type(type))
284 	{
285           /* Print the unmangled name if desired.  */
286 	  /* Print vtable entry - we only get here if NOT using
287 	     -fvtable_thunks.  (Otherwise, look under TYPE_CODE_PTR.) */
288 	  print_address_demangle(*((int *) (valaddr +	/* FIXME bytesex */
289 	      TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8)),
290 	      stream, demangle);
291 	}
292       else
293 	cp_print_value_fields (type, valaddr, address, stream, format,
294 			       recurse, pretty, NULL, 0);
295       break;
296 
297     case TYPE_CODE_ENUM:
298       if (format)
299 	{
300 	  print_scalar_formatted (valaddr, type, format, 0, stream);
301 	  break;
302 	}
303       len = TYPE_NFIELDS (type);
304       val = unpack_long (type, valaddr);
305       for (i = 0; i < len; i++)
306 	{
307 	  QUIT;
308 	  if (val == TYPE_FIELD_BITPOS (type, i))
309 	    {
310 	      break;
311 	    }
312 	}
313       if (i < len)
314 	{
315 	  fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
316 	}
317       else
318 	{
319 	  print_longest (stream, 'd', 0, val);
320 	}
321       break;
322 
323     case TYPE_CODE_FUNC:
324       if (format)
325 	{
326 	  print_scalar_formatted (valaddr, type, format, 0, stream);
327 	  break;
328 	}
329       /* FIXME, we should consider, at least for ANSI C language, eliminating
330 	 the distinction made between FUNCs and POINTERs to FUNCs.  */
331       fprintf_filtered (stream, "{");
332       type_print (type, "", stream, -1);
333       fprintf_filtered (stream, "} ");
334       /* Try to print what function it points to, and its address.  */
335       print_address_demangle (address, stream, demangle);
336       break;
337 
338     case TYPE_CODE_BOOL:
339       format = format ? format : output_format;
340       if (format)
341 	print_scalar_formatted (valaddr, type, format, 0, stream);
342       else
343 	{
344 	  val = unpack_long (type, valaddr);
345 	  if (val == 0)
346 	    fputs_filtered ("false", stream);
347 	  else if (val == 1)
348 	    fputs_filtered ("true", stream);
349 	  else
350 	    print_longest (stream, 'd', 0, val);
351 	}
352       break;
353 
354     case TYPE_CODE_RANGE:
355       /* FIXME: create_range_type does not set the unsigned bit in a
356 	 range type (I think it probably should copy it from the target
357 	 type), so we won't print values which are too large to
358 	 fit in a signed integer correctly.  */
359       /* FIXME: Doesn't handle ranges of enums correctly.  (Can't just
360 	 print with the target type, though, because the size of our type
361 	 and the target type might differ).  */
362       /* FALLTHROUGH */
363 
364     case TYPE_CODE_INT:
365       format = format ? format : output_format;
366       if (format)
367 	{
368 	  print_scalar_formatted (valaddr, type, format, 0, stream);
369 	}
370       else
371 	{
372 	  val_print_type_code_int (type, valaddr, stream);
373 	  /* C and C++ has no single byte int type, char is used instead.
374 	     Since we don't know whether the value is really intended to
375 	     be used as an integer or a character, print the character
376 	     equivalent as well. */
377 	  if (TYPE_LENGTH (type) == 1)
378 	    {
379 	      fputs_filtered (" ", stream);
380 	      LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr),
381 			     stream);
382 	    }
383 	}
384       break;
385 
386     case TYPE_CODE_CHAR:
387       format = format ? format : output_format;
388       if (format)
389 	{
390 	  print_scalar_formatted (valaddr, type, format, 0, stream);
391 	}
392       else
393 	{
394 	  fprintf_filtered (stream, TYPE_UNSIGNED (type) ? "%u" : "%d",
395 			    unpack_long (type, valaddr));
396 	  fputs_filtered (" ", stream);
397 	  LA_PRINT_CHAR ((unsigned char) unpack_long (type, valaddr), stream);
398 	}
399       break;
400 
401     case TYPE_CODE_FLT:
402       if (format)
403 	{
404 	  print_scalar_formatted (valaddr, type, format, 0, stream);
405 	}
406       else
407 	{
408 	  print_floating (valaddr, type, stream);
409 	}
410       break;
411 
412     case TYPE_CODE_VOID:
413       fprintf_filtered (stream, "void");
414       break;
415 
416     case TYPE_CODE_ERROR:
417       fprintf_filtered (stream, "<error type>");
418       break;
419 
420     case TYPE_CODE_UNDEF:
421       /* This happens (without TYPE_FLAG_STUB set) on systems which don't use
422 	 dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar"
423 	 and no complete type for struct foo in that file.  */
424       fprintf_filtered (stream, "<incomplete type>");
425       break;
426 
427     default:
428       error ("Invalid C/C++ type code %d in symbol table.", TYPE_CODE (type));
429     }
430   gdb_flush (stream);
431   return (0);
432 }
433 
434 int
435 c_value_print (val, stream, format, pretty)
436      value_ptr val;
437      GDB_FILE *stream;
438      int format;
439      enum val_prettyprint pretty;
440 {
441   struct type *type = VALUE_TYPE (val);
442 
443   /* If it is a pointer, indicate what it points to.
444 
445      Print type also if it is a reference.
446 
447      C++: if it is a member pointer, we will take care
448      of that when we print it.  */
449   if (TYPE_CODE (type) == TYPE_CODE_PTR ||
450       TYPE_CODE (type) == TYPE_CODE_REF)
451     {
452       /* Hack:  remove (char *) for char strings.  Their
453 	 type is indicated by the quoted string anyway. */
454       if (TYPE_CODE (type) == TYPE_CODE_PTR &&
455 	  TYPE_NAME (type) == NULL &&
456 	  TYPE_NAME (TYPE_TARGET_TYPE (type)) != NULL &&
457 	  STREQ (TYPE_NAME (TYPE_TARGET_TYPE (type)), "char"))
458 	{
459 	  /* Print nothing */
460 	}
461       else
462 	{
463 	  fprintf_filtered (stream, "(");
464 	  type_print (type, "", stream, -1);
465 	  fprintf_filtered (stream, ") ");
466 	}
467     }
468   return val_print (type, VALUE_CONTENTS (val),
469 		    VALUE_ADDRESS (val) + VALUE_OFFSET (val),
470 		    stream, format, 1, 0, pretty);
471 }
472