valprint.c

早期freebsd实现

	      /* Bitfields require special handling, especially due to byte
		 order problems.  */
	      v = value_from_longest (TYPE_FIELD_TYPE (type, i),
				   unpack_field_as_long (type, valaddr, i));

	      val_print (TYPE_FIELD_TYPE (type, i), VALUE_CONTENTS (v), 0,
			 stream, format, 0, recurse + 1, pretty);
	    }
	  else
	    {
	      val_print (TYPE_FIELD_TYPE (type, i), 
			 valaddr + TYPE_FIELD_BITPOS (type, i) / 8,
			 0, stream, format, 0, recurse + 1, pretty);
	    }
	}
      if (pretty)
	{
	  fprintf_filtered (stream, "\n");
	  print_spaces_filtered (2 * recurse, stream);
	}
    }
  fprintf_filtered (stream, "}");
}

/* Special val_print routine to avoid printing multiple copies of virtual
   baseclasses.  */

static void
cplus_val_print (type, valaddr, stream, format, recurse, pretty, dont_print)
     struct type *type;
     char *valaddr;
     FILE *stream;
     int format;
     int recurse;
     enum val_prettyprint pretty;
     struct type **dont_print;
{
  struct obstack tmp_obstack;
  struct type **last_dont_print
    = (struct type **)obstack_next_free (&dont_print_obstack);
  int i, n_baseclasses = TYPE_N_BASECLASSES (type);

  if (dont_print == 0)
    {
      /* If we're at top level, carve out a completely fresh
	 chunk of the obstack and use that until this particular
	 invocation returns.  */
      tmp_obstack = dont_print_obstack;
      /* Bump up the high-water mark.  Now alpha is omega.  */
      obstack_finish (&dont_print_obstack);
    }

  for (i = 0; i < n_baseclasses; i++)
    {
      char *baddr;
      int err;

      if (BASETYPE_VIA_VIRTUAL (type, i))
	{
	  struct type **first_dont_print
	    = (struct type **)obstack_base (&dont_print_obstack);

	  int j = (struct type **)obstack_next_free (&dont_print_obstack)
	    - first_dont_print;

	  while (--j >= 0)
	    if (TYPE_BASECLASS (type, i) == first_dont_print[j])
	      goto flush_it;

	  obstack_ptr_grow (&dont_print_obstack, TYPE_BASECLASS (type, i));
	}

      /* Fix to use baseclass_offset instead. FIXME */
      baddr = baseclass_addr (type, i, valaddr, 0, &err);
      if (err == 0 && baddr == 0)
	error ("could not find virtual baseclass `%s'\n",
	       type_name_no_tag (TYPE_BASECLASS (type, i)));

      if (pretty)
	{
	  fprintf_filtered (stream, "\n");
	  print_spaces_filtered (2 * recurse, stream);
	}
      fputs_filtered ("<", stream);
      fputs_filtered (type_name_no_tag (TYPE_BASECLASS (type, i)), stream);
      fputs_filtered ("> = ", stream);
      if (err != 0)
	fprintf_filtered (stream, "<invalid address 0x%x>", baddr);
      else
	val_print_fields (TYPE_BASECLASS (type, i), baddr, stream, format,
			  recurse, pretty,
			  (struct type **)obstack_base (&dont_print_obstack));
      fputs_filtered (", ", stream);

    flush_it:
      ;
    }

  if (dont_print == 0)
    {
      /* Free the space used to deal with the printing
	 of this type from top level.  */
      obstack_free (&dont_print_obstack, last_dont_print);
      /* Reset watermark so that we can continue protecting
	 ourselves from whatever we were protecting ourselves.  */
      dont_print_obstack = tmp_obstack;
    }
}

static void
print_class_member (valaddr, domain, stream, prefix)
     char *valaddr;
     struct type *domain;
     FILE *stream;
     char *prefix;
{
  
  /* VAL is a byte offset into the structure type DOMAIN.
     Find the name of the field for that offset and
     print it.  */
  int extra = 0;
  int bits = 0;
  register unsigned int i;
  unsigned len = TYPE_NFIELDS (domain);
  /* @@ Make VAL into bit offset */
  LONGEST val = unpack_long (builtin_type_int, valaddr) << 3;
  for (i = TYPE_N_BASECLASSES (domain); i < len; i++)
    {
      int bitpos = TYPE_FIELD_BITPOS (domain, i);
      QUIT;
      if (val == bitpos)
	break;
      if (val < bitpos && i != 0)
	{
	  /* Somehow pointing into a field.  */
	  i -= 1;
	  extra = (val - TYPE_FIELD_BITPOS (domain, i));
	  if (extra & 0x7)
	    bits = 1;
	  else
	    extra >>= 3;
	  break;
	}
    }
  if (i < len)
    {
      char *name;
      fprintf_filtered (stream, prefix);
      name = type_name_no_tag (domain);
      if (name)
        fputs_filtered (name, stream);
      else
	type_print_base (domain, stream, 0, 0);
      fprintf_filtered (stream, "::");
      fputs_filtered (TYPE_FIELD_NAME (domain, i), stream);
      if (extra)
	fprintf_filtered (stream, " + %d bytes", extra);
      if (bits)
	fprintf_filtered (stream, " (offset in bits)");
    }
  else
    fprintf_filtered (stream, "%d", val >> 3);
}

/* Print data of type TYPE located at VALADDR (within GDB),
   which came from the inferior at address ADDRESS,
   onto stdio stream STREAM according to FORMAT
   (a letter or 0 for natural format).  The data at VALADDR
   is in target byte order.

   If the data are a string pointer, returns the number of
   sting characters printed.

   if DEREF_REF is nonzero, then dereference references,
   otherwise just print them like pointers.

   The PRETTY parameter controls prettyprinting.  */

int
val_print (type, valaddr, address, stream, format, deref_ref, recurse, pretty)
     struct type *type;
     char *valaddr;
     CORE_ADDR address;
     FILE *stream;
     int format;
     int deref_ref;
     int recurse;
     enum val_prettyprint pretty;
{
  register unsigned int i;
  unsigned len;
  struct type *elttype;
  unsigned eltlen;
  LONGEST val;
  unsigned char c;

  if (pretty == Val_pretty_default)
    {
      pretty = prettyprint ? Val_prettyprint : Val_no_prettyprint;
    }
  
  QUIT;

  check_stub_type (type);
  
  if (TYPE_FLAGS (type) & TYPE_FLAG_STUB)
    {
      fprintf_filtered (stream, "<unknown struct>");
      fflush (stream);
      return 0;
    }
  
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_ARRAY:
      if (TYPE_LENGTH (type) > 0
	  && TYPE_LENGTH (TYPE_TARGET_TYPE (type)) > 0)
	{
	  elttype = TYPE_TARGET_TYPE (type);
	  eltlen = TYPE_LENGTH (elttype);
	  len = TYPE_LENGTH (type) / eltlen;
	  if (arrayprint)
	    print_spaces_filtered (2 + 2 * recurse, stream);
	  fprintf_filtered (stream, "{");
	  /* For an array of chars, print with string syntax.  */
	  if (eltlen == 1 && TYPE_CODE (elttype) == TYPE_CODE_INT
	      && (format == 0 || format == 's') )
	    print_string (stream, valaddr, len, 0);
	  else
	    {
	      unsigned int things_printed = 0;
	      
	      /* If this is a virtual function table, print the 0th
		 entry specially, and the rest of the members normally.  */
	      if (is_vtbl_ptr_type (elttype))
		{
		  fprintf_filtered (stream, "%d vtable entries", len-1);
		  i = 1;
		}
	      else
		i = 0;

	      for (; i < len && things_printed < print_max; i++)
		{
		  /* Position of the array element we are examining to see
		     whether it is repeated.  */
		  unsigned int rep1;
		  /* Number of repetitions we have detected so far.  */
		  unsigned int reps;
		  
		  if (i != 0)
		    if (arrayprint)
		      {
		        fprintf_filtered (stream, ",\n");
	                print_spaces_filtered (2 + 2 * recurse, stream);
		      }
		    else
		      fprintf_filtered (stream, ", ");
		    wrap_here (n_spaces (2 + 2 * recurse));
		  
		  rep1 = i + 1;
		  reps = 1;
		  while (rep1 < len
			 && !memcmp (valaddr + i * eltlen,
				     valaddr + rep1 * eltlen, eltlen))
		    {
		      ++reps;
		      ++rep1;
		    }

		  if (reps > REPEAT_COUNT_THRESHOLD)
		    {
		      val_print (elttype, valaddr + i * eltlen,
				 0, stream, format, deref_ref,
				 recurse + 1, pretty);
		      fprintf_filtered (stream, " <repeats %u times>", reps);
		      i = rep1 - 1;
		      things_printed += REPEAT_COUNT_THRESHOLD;
		    }
		  else
		    {
		      val_print (elttype, valaddr + i * eltlen,
				 0, stream, format, deref_ref,
				 recurse + 1, pretty);
		      things_printed++;
		    }
		}
	      if (i < len)
		fprintf_filtered (stream, "...");
	    }
	  fprintf_filtered (stream, "}");
	  break;
	}
      /* Array of unspecified length: treat like pointer to first elt.  */
      valaddr = (char *) &address;

    case TYPE_CODE_PTR:
      if (format && format != 's')
	{
	  print_scalar_formatted (valaddr, type, format, 0, stream);
	  break;
	}
      if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD)
	{
	  struct type *domain, *ttype;
	  struct fn_field *f;
	  int j, len2;
	  char *kind = "";
	  CORE_ADDR addr;

	  ttype = TYPE_TARGET_TYPE (type);
	  if (ttype == 0 || (domain = TYPE_DOMAIN_TYPE(ttype)) == 0) {
		  printf("<bug workaround: can't print ptr to method>\n");
		  break;
	  }

	  addr = unpack_pointer (lookup_pointer_type (builtin_type_void),
				valaddr);
	  if (METHOD_PTR_IS_VIRTUAL(addr))
	    {
	      int offset = METHOD_PTR_TO_VOFFSET(addr);
	      len = TYPE_NFN_FIELDS (domain);
	      for (i = 0; i < len; i++)
		{
		  f = TYPE_FN_FIELDLIST1 (domain, i);
		  len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i);

		  for (j = 0; j < len2; j++)
		    {
		      QUIT;
		      if (TYPE_FN_FIELD_VOFFSET (f, j) == offset)
			{
			  kind = "virtual ";
			  goto common;
			}
		    }
		}
	    }
	  else
	    {
	      struct symbol *sym = find_pc_function (addr);
	      if (sym == 0)
		error ("invalid pointer to member function");
	      len = TYPE_NFN_FIELDS (domain);
	      for (i = 0; i < len; i++)
		{
		  f = TYPE_FN_FIELDLIST1 (domain, i);
		  len2 = TYPE_FN_FIELDLIST_LENGTH (domain, i);

		  for (j = 0; j < len2; j++)
		    {
		      QUIT;
		      if (!strcmp (SYMBOL_NAME (sym), TYPE_FN_FIELD_PHYSNAME (f, j)))
			goto common;
		    }
		}
	    }
	common:
	  if (i < len)
	    {
	      fprintf_filtered (stream, "&");
	      type_print_varspec_prefix (TYPE_FN_FIELD_TYPE (f, j), stream, 0, 0);
	      fprintf (stream, kind);
	      if (TYPE_FN_FIELD_PHYSNAME (f, j)[0] == '_'
		  && TYPE_FN_FIELD_PHYSNAME (f, j)[1] == CPLUS_MARKER)
		type_print_method_args
		  (TYPE_FN_FIELD_ARGS (f, j) + 1, "~",
		   TYPE_FN_FIELDLIST_NAME (domain, i), 0, stream);
	      else
		type_print_method_args
		  (TYPE_FN_FIELD_ARGS (f, j), "",
		   TYPE_FN_FIELDLIST_NAME (domain, i), 0, stream);
	      break;
	    }
	  fprintf_filtered (stream, "(");
  	  type_print (type, "", stream, -1);
	  fprintf_filtered (stream, ") %d", (int) addr >> 3);
	}
      else if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
	{
	  print_class_member (valaddr,
			      TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
			      stream, "&");
	}
      else
	{
	  CORE_ADDR addr = unpack_pointer (type, valaddr);
	  elttype = TYPE_TARGET_TYPE (type);

	  if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
	    {
	      /* Try to print what function it points to.  */
	      print_address_demangle (addr, stream, demangle);
	      /* Return value is irrelevant except for string pointers.  */
	      return 0;
	    }

	  if (addressprint && format != 's')
	    fprintf_filtered (stream, "0x%x", addr);

	  /* For a pointer to char or unsigned char,
	     also print the string pointed to, unless pointer is null.  */
	  i = 0;		/* Number of characters printed.  */
	  if (TYPE_LENGTH (elttype) == 1 
	      && TYPE_CODE (elttype) == TYPE_CODE_INT
	      && (format == 0 || format == 's')
	      && addr != 0
	      /* If print_max is UINT_MAX, the alloca below will fail.
	         In that case don't try to print the string.  */
	      && print_max < UINT_MAX)
	    {
	      int first_addr_err = 0;
	      int errcode = 0;
	      
	      /* Get first character.  */
	      errcode = target_read_memory (addr, (char *)&c, 1);
	      if (errcode != 0)
		{
		  /* First address out of bounds.  */
		  first_addr_err = 1;
		}
	      else
		{
		  /* A real string.  */
		  char *string = (char *) alloca (print_max);

		  /* If the loop ends by us hitting print_max characters,
		     we need to have elipses at the end.  */
		  int force_ellipses = 1;

		  /* This loop always fetches print_max characters, even
		     though print_string might want to print more or fewer
		     (with repeated characters).  This is so that
		     we don't spend forever fetching if we print
		     a long string consisting of the same character
		     repeated.  Also so we can do it all in one memory
		     operation, which is faster.  However, this will be
		     slower if print_max is set high, e.g. if you set
		     print_max to 1000, not only will it take a long
		     time to fetch short strings, but if you are near
		     the end of the address space, it might not work. */
		  QUIT;
		  errcode = target_read_memory (addr, string, print_max);
		  if (errcode != 0)
		    {
		      /* Try reading just one character.  If that succeeds,
			 assume we hit the end of the address space, but
			 the initial part of the string is probably safe. */
		      char x[1];
		      errcode = target_read_memory (addr, x, 1);
		    }
		  if (errcode != 0)
		      force_ellipses = 0;
		  else 
		    for (i = 0; i < print_max; i++)
		      if (string[i] == '\0')
			{
			  force_ellipses = 0;
			  break;
		        }
		  QUIT;

		  if (addressprint)
		    fputs_filtered (" ", stream);
		  print_string (stream, string, i, force_ellipses);
		}

	      if (errcode != 0)
		{
		  if (errcode == EIO)
		    {
		      fprintf_filtered (stream,
					(" <Address 0x%x out of bounds>"
					 + first_addr_err),
					addr + i);
		    }
		  else
		    {
		      error ("Error reading memory address 0x%x: %s.",
			     addr + i, safe_strerror (errcode));
		    }
		}

	      fflush (stream);
	    }
	  else /* print vtbl's nicely */
 	  if (is_vtbl_member(type))
  	    {
	      CORE_ADDR vt_address = unpack_pointer (type, valaddr);

	      struct minimal_symbol *msymbol =
		lookup_minimal_symbol_by_pc (vt_address);
	      if ((msymbol != NULL) && (vt_address == msymbol -> address))
		{
		  fputs_filtered (" <", stream);
		  fputs_demangled (msymbol -> name, stream,
				   DMGL_ANSI | DMGL_PARAMS);
		  fputs_filtered (">", stream);
		}
	      if (vtblprint)
	        {
		  value vt_val;

		  vt_val = value_at (TYPE_TARGET_TYPE (type), vt_address);
		  val_print (VALUE_TYPE (vt_val), VALUE_CONTENTS (vt_val),
			     VALUE_ADDRESS (vt_val), stream, format,
			     deref_ref, recurse + 1, pretty);
		  if (pretty)
		    {
		      fprintf_filtered (stream, "\n");
		      print_spaces_filtered (2 + 2 * recurse, stream);
		    }
	        }
	      }

	  /* Return number of characters printed, plus one for the
	     terminating null if we have "reached the end".  */
	  return i + (print_max && i != print_max);
	}
      break;

    case TYPE_CODE_MEMBER:
      error ("not implemented: member type in val_print");
      break;

    case TYPE_CODE_REF:
      {
	CORE_ADDR addr = unpack_long (builtin_type_int, valaddr);
	if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_MEMBER)
	  {
	    print_class_member (valaddr,
				TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (type)),
				stream, "");
	    break;
	  }
	if (addressprint)
	  {
	    fprintf_filtered (stream, "@0x%lx", addr);
	    if (deref_ref)
	      fputs_filtered (": ", stream);
	  }
	/* De-reference the reference.  */
	if (deref_ref)
	  {
	    if (target_read_memory(addr, (char *)&c, 1))
	     {
	       fprintf_filtered (stream, "<Address out of bounds>");
	       break;
	     }
	    if (TYPE_CODE (TYPE_TARGET_TYPE (type)) != TYPE_CODE_UNDEF)
	      {
		value deref_val = value_at (TYPE_TARGET_TYPE (type), addr);
		val_print (VALUE_TYPE (deref_val), VALUE_CONTENTS (deref_val),
			   VALUE_ADDRESS (deref_val), stream, format,
			   deref_ref, recurse + 1, pretty);
	      }