/home/stan/gdb/src/gdb/jv-valprint.c

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/* Support for printing Java values for GDB, the GNU debugger.

   Copyright (C) 1997-2013 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "gdbcore.h"
#include "expression.h"
#include "value.h"
#include "demangle.h"
#include "valprint.h"
#include "language.h"
#include "jv-lang.h"
#include "c-lang.h"
#include "annotate.h"
#include "gdb_string.h"

/* Local functions */

void
java_value_print (struct value *val, struct ui_file *stream, 
                  const struct value_print_options *options)
{
  struct gdbarch *gdbarch = get_type_arch (value_type (val));
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  struct type *type;
  CORE_ADDR address;
  int i;
  const char *name;
  struct value_print_options opts;

  type = value_type (val);
  address = value_address (val);

  if (is_object_type (type))
    {
      CORE_ADDR obj_addr;
      struct value *tem = val;

      /* Get the run-time type, and cast the object into that.  */
      while (TYPE_CODE (value_type (tem)) == TYPE_CODE_PTR)
        tem = value_ind (tem);

      obj_addr = value_address (tem);

      if (obj_addr != 0)
        {
          type = type_from_class (gdbarch, java_class_from_object (val));
          type = lookup_pointer_type (type);

          val = value_at (type, address);
        }
    }

  if (TYPE_CODE (type) == TYPE_CODE_PTR && !value_logical_not (val))
    type_print (TYPE_TARGET_TYPE (type), "", stream, -1);

  name = TYPE_TAG_NAME (type);
  if (TYPE_CODE (type) == TYPE_CODE_STRUCT && name != NULL
      && (i = strlen (name), name[i - 1] == ']'))
    {
      gdb_byte buf4[4];
      long length;
      unsigned int things_printed = 0;
      int reps;
      struct type *el_type
        = java_primitive_type_from_name (gdbarch, name, i - 2);

      i = 0;
      read_memory (address + get_java_object_header_size (gdbarch), buf4, 4);

      length = (long) extract_signed_integer (buf4, 4, byte_order);
      fprintf_filtered (stream, "{length: %ld", length);

      if (el_type == NULL)
        {
          CORE_ADDR element;
          CORE_ADDR next_element = -1; /* Dummy initial value.  */

          /* Skip object header and length.  */
          address += get_java_object_header_size (gdbarch) + 4;

          while (i < length && things_printed < options->print_max)
            {
              gdb_byte *buf;

              buf = alloca (gdbarch_ptr_bit (gdbarch) / HOST_CHAR_BIT);
              fputs_filtered (", ", stream);
              wrap_here (n_spaces (2));

              if (i > 0)
                element = next_element;
              else
                {
                  read_memory (address, buf, sizeof (buf));
                  address += gdbarch_ptr_bit (gdbarch) / HOST_CHAR_BIT;
                  /* FIXME: cagney/2003-05-24: Bogus or what.  It
                     pulls a host sized pointer out of the target and
                     then extracts that as an address (while assuming
                     that the address is unsigned)!  */
                  element = extract_unsigned_integer (buf, sizeof (buf),
                                                      byte_order);
                }

              for (reps = 1; i + reps < length; reps++)
                {
                  read_memory (address, buf, sizeof (buf));
                  address += gdbarch_ptr_bit (gdbarch) / HOST_CHAR_BIT;
                  /* FIXME: cagney/2003-05-24: Bogus or what.  It
                     pulls a host sized pointer out of the target and
                     then extracts that as an address (while assuming
                     that the address is unsigned)!  */
                  next_element = extract_unsigned_integer (buf, sizeof (buf),
                                                           byte_order);
                  if (next_element != element)
                    break;
                }

              if (reps == 1)
                fprintf_filtered (stream, "%d: ", i);
              else
                fprintf_filtered (stream, "%d..%d: ", i, i + reps - 1);

              if (element == 0)
                fprintf_filtered (stream, "null");
              else
                fprintf_filtered (stream, "@%s", paddress (gdbarch, element));

              things_printed++;
              i += reps;
            }
        }
      else
        {
          struct value *v = allocate_value (el_type);
          struct value *next_v = allocate_value (el_type);

          set_value_address (v, (address
                                 + get_java_object_header_size (gdbarch) + 4));
          set_value_address (next_v, value_raw_address (v));

          while (i < length && things_printed < options->print_max)
            {
              fputs_filtered (", ", stream);
              wrap_here (n_spaces (2));

              if (i > 0)
                {
                  struct value *tmp;

                  tmp = next_v;
                  next_v = v;
                  v = tmp;
                }
              else
                {
                  set_value_lazy (v, 1);
                  set_value_offset (v, 0);
                }

              set_value_offset (next_v, value_offset (v));

              for (reps = 1; i + reps < length; reps++)
                {
                  set_value_lazy (next_v, 1);
                  set_value_offset (next_v, value_offset (next_v)
                                    + TYPE_LENGTH (el_type));
                  value_fetch_lazy (next_v);
                  if (!(value_available_contents_eq
                        (v, value_embedded_offset (v),
                         next_v, value_embedded_offset (next_v),
                         TYPE_LENGTH (el_type))))
                    break;
                }

              if (reps == 1)
                fprintf_filtered (stream, "%d: ", i);
              else
                fprintf_filtered (stream, "%d..%d: ", i, i + reps - 1);

              opts = *options;
              opts.deref_ref = 1;
              common_val_print (v, stream, 1, &opts, current_language);

              things_printed++;
              i += reps;
            }
        }

      if (i < length)
        fprintf_filtered (stream, "...");

      fprintf_filtered (stream, "}");

      return;
    }

  /* If it's type String, print it.  */

  if (TYPE_CODE (type) == TYPE_CODE_PTR
      && TYPE_TARGET_TYPE (type)
      && TYPE_TAG_NAME (TYPE_TARGET_TYPE (type))
      && strcmp (TYPE_TAG_NAME (TYPE_TARGET_TYPE (type)),
                 "java.lang.String") == 0
      && (options->format == 0 || options->format == 's')
      && address != 0
      && value_as_address (val) != 0)
    {
      struct type *char_type;
      struct value *data_val;
      CORE_ADDR data;
      struct value *boffset_val;
      unsigned long boffset;
      struct value *count_val;
      unsigned long count;
      struct value *mark;

      fputs_filtered (" ", stream);

      mark = value_mark ();     /* Remember start of new values.  */

      data_val = value_struct_elt (&val, NULL, "data", NULL, NULL);
      data = value_as_address (data_val);

      boffset_val = value_struct_elt (&val, NULL, "boffset", NULL, NULL);
      boffset = value_as_address (boffset_val);

      count_val = value_struct_elt (&val, NULL, "count", NULL, NULL);
      count = value_as_address (count_val);

      value_free_to_mark (mark);        /* Release unnecessary values.  */

      char_type = builtin_java_type (gdbarch)->builtin_char;
      val_print_string (char_type, NULL, data + boffset, count, stream,
                        options);

      return;
    }

  opts = *options;
  opts.deref_ref = 1;
  common_val_print (val, stream, 0, &opts, current_language);
}

/* TYPE, VALADDR, ADDRESS, STREAM, RECURSE, and OPTIONS have the
   same meanings as in cp_print_value and c_val_print.

   DONT_PRINT is an array of baseclass types that we
   should not print, or zero if called from top level.  */

static void
java_print_value_fields (struct type *type, const gdb_byte *valaddr,
                         int offset,
                         CORE_ADDR address, struct ui_file *stream,
                         int recurse,
                         const struct value *val,
                         const struct value_print_options *options)
{
  int i, len, n_baseclasses;

  CHECK_TYPEDEF (type);

  fprintf_filtered (stream, "{");
  len = TYPE_NFIELDS (type);
  n_baseclasses = TYPE_N_BASECLASSES (type);

  if (n_baseclasses > 0)
    {
      int i, n_baseclasses = TYPE_N_BASECLASSES (type);

      for (i = 0; i < n_baseclasses; i++)
        {
          int boffset;
          struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
          const char *basename = TYPE_NAME (baseclass);
          const gdb_byte *base_valaddr;

          if (BASETYPE_VIA_VIRTUAL (type, i))
            continue;

          if (basename != NULL && strcmp (basename, "java.lang.Object") == 0)
            continue;

          boffset = 0;

          if (options->prettyformat)
            {
              fprintf_filtered (stream, "\n");
              print_spaces_filtered (2 * (recurse + 1), stream);
            }
          fputs_filtered ("<", stream);
          /* Not sure what the best notation is in the case where there is no
             baseclass name.  */
          fputs_filtered (basename ? basename : "", stream);
          fputs_filtered ("> = ", stream);

          base_valaddr = valaddr;

          java_print_value_fields (baseclass, base_valaddr,
                                   offset + boffset, address,
                                   stream, recurse + 1, val, options);
          fputs_filtered (", ", stream);
        }
    }

  if (!len && n_baseclasses == 1)
    fprintf_filtered (stream, "<No data fields>");
  else
    {
      int fields_seen = 0;

      for (i = n_baseclasses; i < len; i++)
        {
          /* If requested, skip printing of static fields.  */
          if (field_is_static (&TYPE_FIELD (type, i)))
            {
              const char *name = TYPE_FIELD_NAME (type, i);

              if (!options->static_field_print)
                continue;
              if (name != NULL && strcmp (name, "class") == 0)
                continue;
            }
          if (fields_seen)
            fprintf_filtered (stream, ", ");
          else if (n_baseclasses > 0)
            {
              if (options->prettyformat)
                {
                  fprintf_filtered (stream, "\n");
                  print_spaces_filtered (2 + 2 * recurse, stream);
                  fputs_filtered ("members of ", stream);
                  fputs_filtered (type_name_no_tag (type), stream);
                  fputs_filtered (": ", stream);
                }
            }
          fields_seen = 1;

          if (options->prettyformat)
            {
              fprintf_filtered (stream, "\n");
              print_spaces_filtered (2 + 2 * recurse, stream);
            }
          else
            {
              wrap_here (n_spaces (2 + 2 * recurse));
            }

          annotate_field_begin (TYPE_FIELD_TYPE (type, i));

          if (field_is_static (&TYPE_FIELD (type, i)))
            fputs_filtered ("static ", stream);
          fprintf_symbol_filtered (stream, TYPE_FIELD_NAME (type, i),
                                   language_cplus,
                                   DMGL_PARAMS | DMGL_ANSI);
          annotate_field_name_end ();
          fputs_filtered (": ", stream);
          annotate_field_value ();

          if (!field_is_static (&TYPE_FIELD (type, i))
              && TYPE_FIELD_PACKED (type, i))
            {
              struct value *v;

              /* Bitfields require special handling, especially due to byte
                 order problems.  */
              if (TYPE_FIELD_IGNORE (type, i))
                {
                  fputs_filtered ("<optimized out or zero length>", stream);
                }
              else if (value_bits_synthetic_pointer (val,
                                                     TYPE_FIELD_BITPOS (type,
                                                                        i),
                                                     TYPE_FIELD_BITSIZE (type,
                                                                         i)))
                {
                  fputs_filtered (_("<synthetic pointer>"), stream);
                }
              else if (!value_bits_valid (val, TYPE_FIELD_BITPOS (type, i),
                                          TYPE_FIELD_BITSIZE (type, i)))
                {
                  val_print_optimized_out (val, stream);
                }
              else
                {
                  struct value_print_options opts;

                  v = value_field_bitfield (type, i, valaddr, offset, val);

                  opts = *options;
                  opts.deref_ref = 0;
                  common_val_print (v, stream, recurse + 1,
                                    &opts, current_language);
                }
            }
          else
            {
              if (TYPE_FIELD_IGNORE (type, i))
                {
                  fputs_filtered ("<optimized out or zero length>", stream);
                }
              else if (field_is_static (&TYPE_FIELD (type, i)))
                {
                  struct value *v = value_static_field (type, i);

                  if (v == NULL)
                    val_print_optimized_out (NULL, stream);
                  else
                    {
                      struct value_print_options opts;
                      struct type *t = check_typedef (value_type (v));

                      if (TYPE_CODE (t) == TYPE_CODE_STRUCT)
                        v = value_addr (v);
                      opts = *options;
                      opts.deref_ref = 0;
                      common_val_print (v, stream, recurse + 1,
                                        &opts, current_language);
                    }
                }
              else if (TYPE_FIELD_TYPE (type, i) == NULL)
                fputs_filtered ("<unknown type>", stream);
              else
                {
                  struct value_print_options opts = *options;

                  opts.deref_ref = 0;
                  val_print (TYPE_FIELD_TYPE (type, i),
                             valaddr,
                             offset + TYPE_FIELD_BITPOS (type, i) / 8,
                             address, stream, recurse + 1, val, &opts,
                             current_language);
                }
            }
          annotate_field_end ();
        }

      if (options->prettyformat)
        {
          fprintf_filtered (stream, "\n");
          print_spaces_filtered (2 * recurse, stream);
        }
    }
  fprintf_filtered (stream, "}");
}

/* See val_print for a description of the various parameters of this
   function; they are identical.  */

void
java_val_print (struct type *type, const gdb_byte *valaddr,
                int embedded_offset, CORE_ADDR address,
                struct ui_file *stream, int recurse,
                const struct value *val,
                const struct value_print_options *options)
{
  struct gdbarch *gdbarch = get_type_arch (type);
  struct type *target_type;
  CORE_ADDR addr;

  CHECK_TYPEDEF (type);
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_PTR:
      if (options->format && options->format != 's')
        {
          val_print_scalar_formatted (type, valaddr, embedded_offset,
                                      val, options, 0, stream);
          break;
        }
      addr = unpack_pointer (type, valaddr + embedded_offset);
      if (addr == 0)
        {
          fputs_filtered ("null", stream);
          return;
        }
      target_type = check_typedef (TYPE_TARGET_TYPE (type));

      if (TYPE_CODE (target_type) == TYPE_CODE_FUNC)
        {
          /* Try to print what function it points to.  */
          print_address_demangle (options, gdbarch, addr, stream, demangle);
          return;
        }

      if (options->addressprint && options->format != 's')
        {
          fputs_filtered ("@", stream);
          print_longest (stream, 'x', 0, (ULONGEST) addr);
        }

      return;

    case TYPE_CODE_CHAR:
    case TYPE_CODE_INT:
      /* Can't just call c_val_print because that prints bytes as C
         chars.  */
      if (options->format || options->output_format)
        {
          struct value_print_options opts = *options;

          opts.format = (options->format ? options->format
                         : options->output_format);
          val_print_scalar_formatted (type, valaddr, embedded_offset,
                                      val, &opts, 0, stream);
        }
      else if (TYPE_CODE (type) == TYPE_CODE_CHAR
               || (TYPE_CODE (type) == TYPE_CODE_INT
                   && TYPE_LENGTH (type) == 2
                   && strcmp (TYPE_NAME (type), "char") == 0))
        LA_PRINT_CHAR ((int) unpack_long (type, valaddr + embedded_offset),
                       type, stream);
      else
        val_print_type_code_int (type, valaddr + embedded_offset, stream);
      break;

    case TYPE_CODE_STRUCT:
      java_print_value_fields (type, valaddr, embedded_offset,
                               address, stream, recurse, val, options);
      break;

    default:
      c_val_print (type, valaddr, embedded_offset, address, stream,
                   recurse, val, options);
      break;
    }
}