varobj.c   [plain text]

/* Implementation of the GDB variable objects API.
   Copyright 1999, 2000, 2001 Free Software Foundation, Inc.

   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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "value.h"
#include "cp-abi.h"
#include "expression.h"
#include "frame.h"
#include "language.h"
#include "gdbcmd.h"
#include "gdb_string.h"
#include <math.h>

#include "varobj.h"
#include "wrapper.h"

/* Non-zero if we want to see trace of varobj level stuff.  */

int varobjdebug = 0;

/* Non-zero if we use a varobj's full type to construct its children. */
static int varobj_use_dynamic_type = 1;

/* String representations of gdb's format codes */
char *varobj_format_string[] =
  { "natural", "binary", "decimal", "hexadecimal", "octal" };

/* String representations of gdb's known languages */
char *varobj_language_string[] = { "unknown", "C", "C++", "Java" };

/* Data structures */

/* Every root variable has one of these structures saved in its
   varobj. Members which must be free'd are noted. */
struct varobj_root
{
  /* Alloc'd expression for this parent. */
  struct expression *exp;

  /* Block for which this expression is valid */
  struct block *valid_block;

  /* The frame for this expression */
  struct frame_id frame;

  /* If 1, "update" always recomputes the frame & valid block
     using the currently selected frame. */
  int use_selected_frame;

  /* If 1, the variable was IN SCOPE when last updated,
     if 0 it was out of scope.  Use this to tell whether
     the variable has gone from in scope to out of scope
     or vice versa. */
  int in_scope;

  /* Language info for this variable and its children */
  struct language_specific *lang;
  
  /* The varobj for this root node. */
  struct varobj *rootvar;
  
  /* Next root variable */
  struct varobj_root *next;
};

/* Every variable in the system has a structure of this type defined
   for it. This structure holds all information necessary to manipulate
   a particular object variable. Members which must be freed are noted. */
struct varobj
{

  /* Alloc'd name of the variable for this object.. If this variable is a
     child, then this name will be the child's source name.
     (bar, not foo.bar) */
  /* NOTE: This is the "expression" */
  char *name;

  /* Alloc'd expression for this child.  Can be used to create a
     root variable corresponding to this child. */
  char *path_expr;

  /* The alloc'd name for this variable's object. This is here for
     convenience when constructing this object's children. */
  char *obj_name;

  /* Index of this variable in its parent or -1 */
  int index;

  /* The static type of this variable. This may NEVER be NULL. */
  struct type *type;

  /* This is the most specific type of a C++ class object - as obtained from
     value_rtti_type.  It will be set in two cases:

     a) If the varobj is a pointer or reference to a C++ object.  In this
        case the dynamic_type will be a pointer or reference to the full 
	class.
     b) If the varobj is a C++ object.  In this case, it will be the type
        of the full object, and the value field will be adjusted by 
	value_full_object to the full object. */
  struct type *dynamic_type;

  /* The value of this expression or subexpression.  This may be NULL. 
     If varobj_use_dynamic_type is 1, this will be cast to the full type
     if necessary.  */
  struct value *value;

  /* Did an error occur evaluating the expression or getting its value? */
  int error;

  /* The number of (immediate) children this variable has */
  int num_children;

  /* If this object is a child, this points to its immediate parent. */
  struct varobj *parent;

  /* A list of this object's children */
  struct varobj_child *children;

  /* Marker that this is a "fake" child - e.g. the Public, Private, Protected
     varobj's for C++ */
  int fake_child;

  /* Description of the root variable. Points to root variable for children. */
  struct varobj_root *root;

  /* The format of the output for this object */
  enum varobj_display_formats format;

  /* Was this variable updated via a varobj_set_value operation */
  int updated;
};

/* Every variable keeps a linked list of its children, described
   by the following structure. */
/* FIXME: Deprecated.  All should use vlist instead */

struct varobj_child
{

  /* Pointer to the child's data */
  struct varobj *child;

  /* Pointer to the next child */
  struct varobj_child *next;
};

/* A stack of varobjs */
/* FIXME: Deprecated.  All should use vlist instead */

struct vstack
{
  struct varobj *var;
  struct vstack *next;
};

struct cpstack
{
  char *name;
  struct cpstack *next;
};

/* A list of varobjs */

struct vlist
{
  struct varobj *var;
  struct vlist *next;
};

/* This is the list varobj_update builds up */

struct varobj_changelist_elem {
  struct varobj *var;
  enum varobj_type_change type_changed;
  struct varobj_changelist_elem *next;
};

struct varobj_changelist {
  struct varobj_changelist_elem *tail;
  struct varobj_changelist_elem *head;
};

/* Private function prototypes */

/* Helper functions for the above subcommands. */

static int delete_variable (struct cpstack **, struct varobj *, int);

static void delete_variable_1 (struct cpstack **, int *,
			       struct varobj *, int, int);

static int install_variable (struct varobj *);

static void uninstall_variable (struct varobj *);

static struct varobj *child_exists (struct varobj *, int index);

static struct varobj *create_child (struct varobj *, int, char *);

static void save_child_in_parent (struct varobj *, struct varobj *);

static void remove_child_from_parent (struct varobj *, struct varobj *);

/* Utility routines */

static struct varobj *new_variable (void);

static struct varobj *new_root_variable (void);

static void free_variable (struct varobj *var);

static struct cleanup *make_cleanup_free_variable (struct varobj *var);

static struct type *get_type (struct varobj *var);

static struct type *get_type_deref (struct varobj *var, int *was_ptr);

static struct type *get_target_type (struct type *);

static enum varobj_display_formats variable_default_display (struct varobj *);

static int my_value_equal (struct value *, struct value *, int *);

static struct varobj_changelist *varobj_changelist_init ();

static void varobj_add_to_changelist(struct varobj_changelist *changelist, 
				   struct varobj *var, 
				   enum varobj_type_change type_changed);

static void vpush (struct vstack **pstack, struct varobj *var);

static struct varobj *vpop (struct vstack **pstack);

static void cppush (struct cpstack **pstack, char *name);

static char *cppop (struct cpstack **pstack);

/* Language-specific routines. */

static enum varobj_languages variable_language (struct varobj *var);

static int number_of_children (struct varobj *);

static char *name_of_variable (struct varobj *);

static char *path_expr_of_variable (struct varobj *);

static char *make_name_of_child (struct varobj *, int);

static char *path_expr_of_child (struct varobj *, int);

static struct value *value_of_root (struct varobj **var_handle, enum varobj_type_change *);

static struct value *value_of_child (struct varobj *parent, int index,
				     enum varobj_type_change *);

static struct type *type_of_child (struct varobj *var);

static int variable_editable (struct varobj *var);

static char *my_value_of_variable (struct varobj *var);

static int varobj_value_is_changeable_p (struct varobj *var);

static int is_root_p (struct varobj *var);

/* C implementation */

static int c_number_of_children (struct varobj *var);

static char *c_make_name_of_child (struct varobj *parent, int index);

static char *c_path_expr_of_child (struct varobj *parent, int index);

static struct value *c_value_of_root (struct varobj **var_handle, enum varobj_type_change *type_changed);

static struct value *c_value_of_child (struct varobj *parent, int index);

static struct type *c_type_of_child (struct varobj *parent, int index);

static int c_variable_editable (struct varobj *var);

static char *c_value_of_variable (struct varobj *var);

/* C++ implementation */

static int cplus_number_of_children (struct varobj *var);

static void cplus_class_num_children (struct type *type, int children[3]);

static char *cplus_make_name_of_child (struct varobj *parent, int index);

static char *cplus_path_expr_of_child (struct varobj *parent, int index);

static struct value *cplus_value_of_root (struct varobj **var_handle, enum varobj_type_change *type_changed);

static struct value *cplus_value_of_child (struct varobj *parent, int index);

static struct type *cplus_type_of_child (struct varobj *parent, int index);

static int cplus_variable_editable (struct varobj *var);

static char *cplus_value_of_variable (struct varobj *var);

/* Java implementation */

static int java_number_of_children (struct varobj *var);

static char *java_make_name_of_child (struct varobj *parent, int index);

static char *java_path_expr_of_child (struct varobj *parent, int index);

static struct value *java_value_of_root (struct varobj **var_handle, enum varobj_type_change *type_changed);

static struct value *java_value_of_child (struct varobj *parent, int index);

static struct type *java_type_of_child (struct varobj *parent, int index);

static int java_variable_editable (struct varobj *var);

static char *java_value_of_variable (struct varobj *var);

/* The language specific vector */

struct language_specific
{

  /* The language of this variable */
  enum varobj_languages language;

  /* The number of children of PARENT. */
  int (*number_of_children) (struct varobj * parent);

  /* The makes & returns the name of the INDEX'th child of PARENT. */
  char *(*make_name_of_child) (struct varobj * parent, int index);

  /* Returns the rooted expression of the INDEX'th child of PARENT. */
  char *(*path_expr_of_child) (struct varobj * parent, int index);

  /* The ``struct value *'' of the root variable ROOT. */
  struct value *(*value_of_root) (struct varobj ** root_handle, 
				  enum varobj_type_change *type_changed);

  /* The ``struct value *'' of the INDEX'th child of PARENT. */
  struct value *(*value_of_child) (struct varobj * parent, int index);

  /* The type of the INDEX'th child of PARENT. */
  struct type *(*type_of_child) (struct varobj * parent, int index);

  /* Is VAR editable? */
  int (*variable_editable) (struct varobj * var);

  /* The current value of VAR. */
  char *(*value_of_variable) (struct varobj * var);
};

/* Array of known source language routines. */
static struct language_specific
  languages[vlang_end][sizeof (struct language_specific)] = {
  /* Unknown (try treating as C */
  {
   vlang_unknown,
   c_number_of_children,
   c_make_name_of_child,
   c_path_expr_of_child,
   c_value_of_root,
   c_value_of_child,
   c_type_of_child,
   c_variable_editable,
   c_value_of_variable}
  ,
  /* C */
  {
   vlang_c,
   c_number_of_children,
   c_make_name_of_child,
   c_path_expr_of_child,
   c_value_of_root,
   c_value_of_child,
   c_type_of_child,
   c_variable_editable,
   c_value_of_variable}
  ,
  /* C++ */
  {
   vlang_cplus,
   cplus_number_of_children,
   cplus_make_name_of_child,
   cplus_path_expr_of_child,
   cplus_value_of_root,
   cplus_value_of_child,
   cplus_type_of_child,
   cplus_variable_editable,
   cplus_value_of_variable}
  ,
  /* Java */
  {
   vlang_java,
   java_number_of_children,
   java_make_name_of_child,
   java_path_expr_of_child,
   java_value_of_root,
   java_value_of_child,
   java_type_of_child,
   java_variable_editable,
   java_value_of_variable}
};

/* A little convenience enum for dealing with C++/Java */
enum vsections
{
  v_public = 0, v_private, v_protected
};
static int cplus_real_type_index_for_fake_child_index (
                                      struct type *type, 
                                      enum vsections prot, 
                                      int num);

/* Private data */

/* Mappings of varobj_display_formats enums to gdb's format codes */
static int format_code[] = { 0, 't', 'd', 'x', 'o', 'u' };

/* Header of the list of root variable objects */
static struct varobj_root *rootlist;
static int rootcount = 0;	/* number of root varobjs in the list */

/* Prime number indicating the number of buckets in the hash table */
/* A prime large enough to avoid too many colisions */
#define VAROBJ_TABLE_SIZE 227

/* Pointer to the varobj hash table (built at run time) */
static struct vlist **varobj_table;

/* Switch to determine whether to try to freeze the other threads in the 
   inferior when I evaluate varobj's (so that if the varobj is a function
   call I don't inadvertently allow the inferior to make progress while
   evaluating the varobj. */

int varobj_runs_all_threads = 0;

/* Is the variable X one of our "fake" children? */
#define CPLUS_FAKE_CHILD(x) \
((x) != NULL && (x)->fake_child)


/* API Implementation */

static int
is_root_p (struct varobj *var)
{
  return (var->root->rootvar == var);
}

struct value_rtti_args
{
  struct value *val;
  struct type *dynamic_type;
  int *top;
  int *full;
  int *using_enc;
};

static int
wrapped_value_rtti_target_type (struct ui_out *ui_out, void *in_args)
{
  struct value_rtti_args *args = (struct value_rtti_args *) in_args;

  args->dynamic_type = value_rtti_target_type (args->val, args->full, args->top, args->using_enc);

  return 1;
}

static struct type *
safe_value_rtti_target_type (struct value *val, int *full, int *top, int *using_enc)
{
  struct value_rtti_args args; 
  int retval;
  struct ui_file *saved_gdb_stderr;
  static struct ui_file *null_stderr = NULL;

  args.val = val;
  args.full = full;
  args.top = top;
  args.using_enc = using_enc;

  /* suppress error messages */
  if (null_stderr == NULL)
    null_stderr = ui_file_new ();

  saved_gdb_stderr = gdb_stderr;
  gdb_stderr = null_stderr;

  retval = catch_exceptions (uiout, wrapped_value_rtti_target_type, 
			     &args, NULL, RETURN_MASK_ALL);

  gdb_stderr = saved_gdb_stderr;

  if (retval >= 0)
    return args.dynamic_type;
  else
    return NULL;
}

static struct value *
varobj_fixup_value (struct value *in_value, 
		    int use_dynamic_type,
		    struct type **dynamic_type_handle)
{
  /* Look up the full type of the varobj, and record that in
     var->dynamic_type.  Also, if there is an enclosing type, reset
     the value to that full object.  Otherwise, we leave dynamic_type
     NULL, and don't adjust the value. 
     Note: we don't handle the case where TYPE_CODE is TYPE_CODE_CLASS
     since that can't have a dynamic type.  */
  
  struct value *full_value = in_value;
  struct type *dynamic_type;
  struct type *base_type;
      
  dynamic_type = NULL;
  
  base_type = check_typedef (VALUE_TYPE (in_value));
  if (TYPE_CODE(base_type) == TYPE_CODE_PTR)
    {
      int top, full, using_enc;
      
      dynamic_type = safe_value_rtti_target_type (in_value, &full, &top, 
						  &using_enc);
      
      if (dynamic_type)
	{
	  dynamic_type = lookup_pointer_type (dynamic_type);
	}
      else
	{
	  /* If we didn't find a C++ class, let's see if we can find
	     an ObjC class. */
	  int ret_val;

	  ret_val = safe_value_objc_target_type (in_value, &dynamic_type);
	  if (!ret_val)
	    dynamic_type = NULL;
	  else if (dynamic_type)
	    dynamic_type = lookup_pointer_type (dynamic_type);
	}
    }
  else if (TYPE_CODE (base_type) == TYPE_CODE_REF)
    {
      /* Need to create a pointer type for this value so
	 value_rtti_target_type will be happy.  This is also done
	 in c_value_print.  Maybe we should move this into
	 value_rtti_target_type? */
      struct value *temp_val;
      struct type *target_type;
	  
      temp_val = value_copy (in_value);
      target_type = get_target_type (base_type);
      if (target_type != NULL)
	{
	  int full, top, using_enc;
	  
	  VALUE_TYPE (temp_val) = lookup_pointer_type (target_type);
	  dynamic_type = safe_value_rtti_target_type (temp_val, 
						      &full, &top, 
						      &using_enc);
	  if (dynamic_type)
	    dynamic_type = lookup_reference_type (dynamic_type);
	  else
	    {
	      /* If we didn't find a C++ class, let's see if we can find
		 an ObjC class. */
	      int ret_val;

	      ret_val = safe_value_objc_target_type (in_value, &dynamic_type);
	      if (!ret_val)
		dynamic_type = NULL;
	      else if (dynamic_type)
		dynamic_type = lookup_reference_type (dynamic_type);
	    }
	}
    }

  /* Now, if we have found a full type, record the static type in the
     type field, and then cast the value to the new type.  For now we 
     have to wrap the call to value_cast, since gdb fails - sometime with
     a real error - when casting up classes with virtual inheritance.  */
  
  if (dynamic_type && use_dynamic_type)
    {
      int retval;
      retval = gdb_value_cast (dynamic_type, in_value, &full_value);
      /* If there is an error back out, resetting the dynamic value,
	 and the dynamic_type. */

      if (retval == 0)
	{
	  full_value = in_value;
	  dynamic_type = VALUE_TYPE (in_value);
	}
    }

  if (dynamic_type_handle != NULL)
    *dynamic_type_handle = dynamic_type;

  return full_value;
}

/* Creates a varobj (not its children) */

/* Return the full FRAME which corresponds to the given CORE_ADDR
   or NULL if no FRAME on the chain corresponds to CORE_ADDR.  */

static struct frame_info *
find_frame_addr_in_frame_chain (CORE_ADDR frame_addr)
{
  struct frame_info *frame = NULL;

  if (frame_addr == (CORE_ADDR) 0)
    return NULL;

  while (1)
    {
      frame = get_prev_frame (frame);
      if (frame == NULL)
	return NULL;
      if (get_frame_base (frame) == frame_addr)
	return frame;
    }
}

struct varobj *
varobj_create (char *objname,
	       char *expression, CORE_ADDR frame, 
	       struct block *block,
	       enum varobj_type type)
{
  struct varobj *var;
  struct frame_info *fi;
  struct frame_id var_frame_id;
  struct frame_id old_frame_id = null_frame_id;
  struct cleanup *old_chain, *schedlock_chain;
  int expr_len;

  /* Fill out a varobj structure for the (root) variable being constructed. */
  var = new_root_variable ();
  old_chain = make_cleanup_free_variable (var);

  /* We are also going to fix the scheduler-locking here so we
     don't end up running other threads.  Note that not only can
     getting the value cause a function call, even parsing the
     expression for dynamic languages might trigger a lookup 
     call. */
  
  if (!varobj_runs_all_threads)
    schedlock_chain = make_cleanup_set_restore_scheduler_locking_mode (scheduler_locking_on);

  if (expression != NULL)
    {
      char *p;
      enum varobj_languages lang;

      /* Parse and evaluate the expression, filling in as much
         of the variable's data as possible */

      /* Allow creator to specify context of variable */
      if ((type == USE_CURRENT_FRAME) || (type == USE_SELECTED_FRAME)
	  || (type == USE_BLOCK_IN_FRAME))
	fi = deprecated_selected_frame;
      else
	/* FIXME: cagney/2002-11-23: This code should be doing a
	   lookup using the frame ID and not just the frame's
	   ``address''.  This, of course, means an interface change.
	   However, with out that interface change ISAs, such as the
	   ia64 with its two stacks, won't work.  Similar goes for the
	   case where there is a frameless function.  */
	fi = find_frame_addr_in_frame_chain (frame);


      if (fi != NULL)
	var_frame_id = get_frame_id (fi);

      /* frame = -2 means always use selected frame */
      if (type == USE_SELECTED_FRAME)
	var->root->use_selected_frame = 1;

      if (block == NULL)
	{
	  if (type == USE_BLOCK_IN_FRAME) 
	    {
	      warning ("Attempting to create USE_BLOCK_IN_FRAME variable with NULL block.");
	      goto error_cleanup;
	    }
	  else if (fi != NULL)
	    block = get_frame_block (fi, 0);
	}

      p = expression;
      innermost_block = NULL;
      /* Wrap the call to parse expression, so we can 
         return a sensible error.  For use_selected_frame variables
         create a dummy here that will get filled in later when 
         we get to a frame that actually has this variable.  */
      
      if (gdb_parse_exp_1 (&p, block, 0, &var->root->exp))
	{

	  /* Don't allow variables to be created for types. */
	  if (var->root->exp->elts[0].opcode == OP_TYPE)
	    {
	      warning ("Attempt to use a type name as an expression.");
	      goto error_cleanup;
	    }
	}
      else if (var->root->use_selected_frame != 1)
	goto error_cleanup;

      var->format = variable_default_display (var);
      var->root->valid_block = innermost_block;

      expr_len = strlen (expression);
      var->name = savestring (expression, expr_len);
      /* For a root var, the name and the expression are the same... */
      var->path_expr = savestring (expression, expr_len);


      /* Okay, if we were able to make an expression for this variable
	 then evaluate it here. */

      if (var->root->exp != NULL)
	{
	  /* When the frame is different from the current frame, 
	     we must select the appropriate frame before parsing
	     the expression, otherwise the value will not be current.
	     Since select_frame is so benign, just call it for all cases. */
	  if (fi != NULL)
	    {
	      fi = frame_find_by_id (var_frame_id);

	      var->root->frame = var_frame_id;
	      old_frame_id = get_frame_id (get_current_frame ());
	      select_frame (fi);
	    }

	  /* We definitively need to catch errors here.
	     If evaluate_expression succeeds we got the value we wanted.
	     But if it fails, we still go on with a call to evaluate_type().
	     
	     If this not a "use_selected_frame" variable, then it may be
	     in a block which is not yet in scope (for instance when you are
	     creating ALL the variables in a function at a blow).  If the
	     variable is not in scope yet, don't evaluate it.  This will often
	     succeed (since the memory is set aside for it) but that is a bogus
	     success, since technically the variable does not exist yet... */

	      	      
	  if ((var->root->use_selected_frame || varobj_pc_in_valid_block_p (var)) 
	      && gdb_evaluate_expression (var->root->exp, &var->value))
	    {
	      /* no error */

	      var->root->in_scope = 1;
	      
	      var->type = VALUE_TYPE (var->value);

	      var->value = varobj_fixup_value (var->value, varobj_use_dynamic_type, 
					       &(var->dynamic_type));

	      if (VALUE_LAZY (var->value))
		gdb_value_fetch_lazy (var->value);
	    }
	  else
	    {
	      int retval;
	      /* You might wonder how evaluate_type could get an error?
		 If you are in ObjC, then to get the type of an expression that
		 contains a method call, we currently look up the function that
		 implementation, and if the object is bad, the runtime can crash
		 in the lookup call...  */

	      retval = gdb_evaluate_type (var->root->exp, &var->value);
	      if (retval != 0)
		{
		  var->type = VALUE_TYPE (var->value);
		  var->root->in_scope = 0;
		}
	      else
		{
		  var->root->in_scope = 0;
		  var->type = NULL;
		  var->value = NULL;
		}
	    }

	  /* If we managed to find a value, we should
	     remove it from the Values auto-free list */
	  
	  if (var->value)
	    release_value (var->value);
	  
	  /* Set language info */
	  lang = variable_language (var);
	  var->root->lang = languages[lang];
	  
	}
      else
	{
	  /* If we didn't get an expr yet, then just say we
	     are out of scope. */
	  var->root->in_scope = 0;
	}

      /* Set ourselves as our root */
      var->root->rootvar = var;

      /* Reset the selected frame */
      if (frame_id_p (old_frame_id))
	select_frame (frame_find_by_id (old_frame_id));

    }

  /* If the variable object name is null, that means this
     is a temporary variable, so don't install it. */

  if ((var != NULL) && (objname != NULL))
    {
      var->obj_name = savestring (objname, strlen (objname));

      /* If a varobj name is duplicated, the install will fail so
         we must clenup */
      if (!install_variable (var))
	{
	  do_cleanups (old_chain);
	  return NULL;
	}
    }

  /* Reset the scheduler lock, and discard the varobj deletion. */
  do_cleanups (schedlock_chain);
  discard_cleanups (old_chain);
  return var;

 error_cleanup:
  do_cleanups (old_chain);
  return NULL;
}

/* Generates an unique name that can be used for a varobj */

char *
varobj_gen_name (void)
{
  static int id = 0;
  char *obj_name;

  /* generate a name for this object */
  id++;
  xasprintf (&obj_name, "var%d", id);

  return obj_name;
}

/* Given an "objname", returns the pointer to the corresponding varobj
   or NULL if not found */

struct varobj *
varobj_get_handle (char *objname)
{
  struct vlist *cv;
  const char *chp;
  unsigned int index = 0;
  unsigned int i = 1;

  for (chp = objname; *chp; chp++)
    {
      index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
    }

  cv = *(varobj_table + index);
  while ((cv != NULL) && (strcmp (cv->var->obj_name, objname) != 0))
    cv = cv->next;

  if (cv == NULL)
    error ("Variable object not found");

  return cv->var;
}

/* Given the handle, return the name of the object */

char *
varobj_get_objname (struct varobj *var)
{
  return var->obj_name;
}

/* Given the handle, return the expression represented by the object */

char *
varobj_get_expression (struct varobj *var)
{
  return name_of_variable (var);
}

/* Deletes a varobj and all its children if only_children == 0,
   otherwise deletes only the children; returns a malloc'ed list of all the 
   (malloc'ed) names of the variables that have been deleted (NULL terminated) */

int
varobj_delete (struct varobj *var, char ***dellist, int only_children)
{
  int delcount;
  int mycount;
  struct cpstack *result = NULL;
  char **cp;

  /* Initialize a stack for temporary results */
  cppush (&result, NULL);

  if (only_children)
    /* Delete only the variable children */
    delcount = delete_variable (&result, var, 1 /* only the children */ );
  else
    /* Delete the variable and all its children */
    delcount = delete_variable (&result, var, 0 /* parent+children */ );

  /* We may have been asked to return a list of what has been deleted */
  if (dellist != NULL)
    {
      *dellist = xmalloc ((delcount + 1) * sizeof (char *));

      cp = *dellist;
      mycount = delcount;
      *cp = cppop (&result);
      while ((*cp != NULL) && (mycount > 0))
	{
	  mycount--;
	  cp++;
	  *cp = cppop (&result);
	}

      if (mycount || (*cp != NULL))
	warning ("varobj_delete: assertion failed - mycount(=%d) <> 0",
		 mycount);
    }

  return delcount;
}

/* Set/Get variable object display format */

enum varobj_display_formats
varobj_set_display_format (struct varobj *var,
			   enum varobj_display_formats format)
{
  switch (format)
    {
    case FORMAT_NATURAL:
    case FORMAT_BINARY:
    case FORMAT_DECIMAL:
    case FORMAT_HEXADECIMAL:
    case FORMAT_OCTAL:
    case FORMAT_UNSIGNED:
      var->format = format;
      break;

    default:
      var->format = variable_default_display (var);
    }

  return var->format;
}

enum varobj_display_formats
varobj_get_display_format (struct varobj *var)
{
  return var->format;
}

int
varobj_get_num_children (struct varobj *var)
{
  if (var->root->exp == NULL)
    return -1;

  if (var->num_children == -1)
    var->num_children = number_of_children (var);

  return var->num_children;
}

/* Creates a list of the immediate children of a variable object;
   the return code is the number of such children or -1 on error */

int
varobj_list_children (struct varobj *var, struct varobj ***childlist)
{
  struct varobj *child;
  char *name;
  int i;

  /* sanity check: have we been passed a pointer? */
  if (childlist == NULL)
    return -1;

  *childlist = NULL;

  if (var->num_children == -1)
    var->num_children = number_of_children (var);

  /* List of children */
  *childlist = xmalloc ((var->num_children + 1) * sizeof (struct varobj *));

  for (i = 0; i < var->num_children; i++)
    {
      /* Mark as the end in case we bail out */
      *((*childlist) + i) = NULL;

      /* check if child exists, if not create */
      child = child_exists (var, i);
      if (child == NULL)
	{
	  name = make_name_of_child (var, i);
	  child = create_child (var, i, name);
	}

      *((*childlist) + i) = child;
    }

  /* End of list is marked by a NULL pointer */
  *((*childlist) + i) = NULL;

  return var->num_children;
}

int 
varobj_is_fake_child (struct varobj *var)
{
  return CPLUS_FAKE_CHILD (var);
}

/* Obtain the type of an object Variable as a string similar to the one gdb
   prints on the console */

char *
varobj_get_type (struct varobj *var)
{
  struct value *val;

  /* For the "fake" variables, do not return a type. (It's type is
     NULL, too.) */
  if (CPLUS_FAKE_CHILD (var))
    return NULL;

  if (var->type == NULL)
    return savestring ("<error getting type>", strlen ("<error getting type>"));

  /* To print the type, we simply create a zero ``struct value *'' and
     cast it to our type. We then typeprint this variable. */
  val = value_zero (var->type, not_lval);

  return (type_sprint (VALUE_TYPE (val), "", -1));
}

/* Obtain the full (most specific class) type of an object Variable as
   a string similar to the one gdb prints on the console */

char *
varobj_get_dynamic_type (struct varobj *var)
{
  struct value *val;

  if (var->dynamic_type == NULL)
    return xstrdup ("");

  /* To print the type, we simply create a zero ``struct value *'' and
     cast it to our type. We then typeprint this variable. */
  val = value_zero (var->dynamic_type, not_lval);

  return (type_sprint (VALUE_TYPE(val), "", -1));
}

struct type *
varobj_get_type_struct (struct varobj *var)
{
  return get_type (var);
}

char *
varobj_get_path_expr (struct varobj *var)
{
  return path_expr_of_variable (var);
}

enum varobj_languages
varobj_get_language (struct varobj *var)
{
  return variable_language (var);
}

/*
 * Returns whether the variable is in scope or not.  This
 * just checks the flag in the varobj root var, so you are
 * responsible for calling update before you call this.
 */

int
varobj_in_scope_p (struct varobj *var)
{
  return var->root->in_scope;
}

int
varobj_get_attributes (struct varobj *var)
{
  int attributes = 0;

  if (variable_editable (var))
    /* FIXME: define masks for attributes */
    attributes |= 0x00000001;	/* Editable */

  return attributes;
}

void 
varobj_get_valid_block (struct varobj *var, CORE_ADDR *start,
				    CORE_ADDR *end)
{
  if (var->root->valid_block == NULL)
    {
      *start = -1;
      *end = -1;
      return;
    }

  *start = var->root->valid_block->startaddr;
  *end = var->root->valid_block->endaddr;
}

char *
varobj_get_value (struct varobj *var)
{
  if (var->root->exp == NULL)
    return NULL;
  else if (var->value == NULL)
    return NULL;
  else
    return my_value_of_variable (var);
}

/* Set the value of an object variable (if it is editable) to the
   value of the given expression */
/* Note: Invokes functions that can call error() */

int
varobj_set_value (struct varobj *var, char *expression)
{
  struct value *val;
  int error;

  /* The argument "expression" contains the variable's new value.
     We need to first construct a legal expression for this -- ugh! */
  /* Does this cover all the bases? */
  struct expression *exp;
  struct value *value;
  int saved_input_radix = input_radix;
  enum scheduler_locking_mode old_mode;
  int ret_val = 1;
  struct cleanup *schedlock_chain;

  schedlock_chain = make_cleanup_set_restore_scheduler_locking_mode (scheduler_locking_on);

  if (var->value != NULL && variable_editable (var) && !var->error)
    {
      char *s = expression;

      input_radix = 10;		/* ALWAYS reset to decimal temporarily */
      
      if (!gdb_parse_exp_1 (&s, 0, 0, &exp))
	{
	  /* We cannot proceed without a well-formed expression. */
	  ret_val = 0;
	  goto cleanup;
	}
      if (!gdb_evaluate_expression (exp, &value))
	{
	  /* We cannot proceed without a valid expression. */
	  xfree (exp);
	  ret_val = 0;
	  goto cleanup;
	}

      if (!my_value_equal (var->value, value, &error))
	var->updated = 1;
      if (!gdb_value_assign (var->value, value, &val))
	{
	  ret_val = 0;
	  goto cleanup;
	}
      value_free (var->value);
      release_value (val);
      var->value = val;
      input_radix = saved_input_radix;
      ret_val = 1;
    }

 cleanup:
  do_cleanups (schedlock_chain);
  return ret_val;

}

/* Returns a malloc'ed list with all root variable objects */
int
varobj_list (struct varobj ***varlist)
{
  struct varobj **cv;
  struct varobj_root *croot;
  int mycount = rootcount;

  /* Alloc (rootcount + 1) entries for the result */
  *varlist = xmalloc ((rootcount + 1) * sizeof (struct varobj *));

  cv = *varlist;
  croot = rootlist;
  while ((croot != NULL) && (mycount > 0))
    {
      *cv = croot->rootvar;
      mycount--;
      cv++;
      croot = croot->next;
    }
  /* Mark the end of the list */
  *cv = NULL;

  if (mycount || (croot != NULL))
    warning
      ("varobj_list: assertion failed - wrong tally of root vars (%d:%d)",
       rootcount, mycount);

  return rootcount;
}

/* Update the values for a variable and its children.  This is a
   two-pronged attack.  First, re-parse the value for the root's
   expression to see if it's changed.  Then go all the way
   through its children, reconstructing them and noting if they've
   changed.
   Return value:
    -1 if there was an error updating the varobj
    -2 if the type changed
    -3 if it switched from in scope to out of scope
    Otherwise it is the number of children + parent changed

   Only root variables can be updated... 

   NOTE: This function may delete the caller's varobj. If it
   returns -2, then it has done this and VARP will be modified
   to point to the new varobj. */

int
varobj_update (struct varobj **varp, struct varobj_changelist **changelist)
{
  int changed = 0;
  enum varobj_type_change type_changed, child_type_changed;
  int error2;
  struct varobj *v;
  struct value *new;
  struct vstack *stack = NULL;
  struct varobj_changelist *result = NULL;
  struct frame_id old_fid;
  struct frame_info *fi;
  int came_in_scope = 0;

  /* sanity check: have we been passed a pointer? */
  if (changelist == NULL)
    return -1;

  /*  Only root variables can be updated... */
  if ((*varp)->root->rootvar != *varp)
    /* Not a root var */
    return -1;

  /* Save the selected stack frame, since we will need to change it
     in order to evaluate expressions. */
  old_fid = get_frame_id (deprecated_selected_frame);

  /* Update the root variable. value_of_root can return NULL
     if the variable is no longer around, i.e. we stepped out of
     the frame in which a local existed. */
  type_changed = VAROBJ_TYPE_CHANGED;
  new = value_of_root (varp, &type_changed);
  if (new == NULL)
    {
      int retval;
      (*varp)->error = 1;
      if ((*varp)->root->in_scope)
        retval = -3;
      else
        retval = 0;
      (*varp)->root->in_scope = 0;
      return retval;
    }
  else
    {
      (*varp)->error = 0;
      if ((*varp)->root->in_scope)
        came_in_scope = 0;
      else
        came_in_scope = 1;
      (*varp)->root->in_scope = 1;
    }

  /* Now make up the change list */

  result = varobj_changelist_init ();

  /* If the type has changed, then value_of_root will have killed all
     the children, so all we have to do is note that it has changed,
     and we are done... */
  if (type_changed != VAROBJ_TYPE_UNCHANGED)
    {
      varobj_add_to_changelist (result, *varp, type_changed);
      changed++;
    }

  /* If the variable just came in scope, then by definition it has changed */
  
  /* If values are not equal, note that it's changed.
     There a couple of exceptions here, though.
     We don't want some types to be reported as "changed". */

  else if (came_in_scope
           || (varobj_value_is_changeable_p (*varp)
	       && ((*varp)->updated || !my_value_equal ((*varp)->value, new, &error2))))
    {
      varobj_add_to_changelist (result, *varp, type_changed);
      (*varp)->updated = 0;
      changed++;
      /* error2 replaces var->error since this new value
         WILL replace the old one. */
      (*varp)->error = error2;
    }

  /* We must always keep around the new value for this root
     variable expression, or we lose the updated children! */
  value_free ((*varp)->value);
  (*varp)->value = new;
  
  /* Initialize a stack */
  vpush (&stack, NULL);

  /* Push the root's children */
  if ((*varp)->children != NULL)
    {
      struct varobj_child *c;
      for (c = (*varp)->children; c != NULL; c = c->next)
	vpush (&stack, c->child);
    }

  /* Walk through the children, reconstructing them all. */
  v = vpop (&stack);
  while (v != NULL)
    {
      /* First update the child.  Since the dynamic type
	 might change, we need to do this BEFORE we push
	 the children on the stack, since we might need to
	 delete them.  */

      /* Update this variable */
      new = value_of_child (v->parent, v->index, &child_type_changed);
      if ((child_type_changed != VAROBJ_TYPE_UNCHANGED)
	  || came_in_scope
          || (varobj_value_is_changeable_p (v) 
	      && (v->updated || !my_value_equal (v->value, new, &error2))))
	{
	  /* Note that it's changed */
	  varobj_add_to_changelist (result, v, child_type_changed);
	  v->updated = 0;
	  changed++;
	}
      /* error2 replaces v->error since this new value
         WILL replace the old one. */
      v->error = error2;

      /* We must always keep new values, since children depend on it. */
      if (v->value != NULL)
	value_free (v->value);
      v->value = new;

      /* If the type has changed, delete the children, 
	 otherwise push any children */
      if (child_type_changed == VAROBJ_TYPE_UNCHANGED)
	{
	  if (v->children != NULL)
	    {
	      struct varobj_child *c;
	      for (c = v->children; c != NULL; c = c->next)
		vpush (&stack, c->child);
	    }
	}
      else
	{
	  varobj_delete(v, NULL, 1);
	}


      /* Get next child */
      v = vpop (&stack);
    }

  /* Restore selected frame */
  fi = frame_find_by_id (old_fid);
  if (fi)
    select_frame (fi);

  *changelist = result;

  if (type_changed != VAROBJ_TYPE_UNCHANGED)
    return -2;
  else
    return changed;
}


/* Helper functions */

/*
 * Variable object construction/destruction
 */

static int
delete_variable (struct cpstack **resultp, struct varobj *var,
		 int only_children_p)
{
  int delcount = 0;

  delete_variable_1 (resultp, &delcount, var,
		     only_children_p, 1 /* remove_from_parent_p */ );

  return delcount;
}

/* Delete the variable object VAR and its children */
/* IMPORTANT NOTE: If we delete a variable which is a child
   and the parent is not removed we dump core.  It must be always
   initially called with remove_from_parent_p set */
static void
delete_variable_1 (struct cpstack **resultp, int *delcountp,
		   struct varobj *var, int only_children_p,
		   int remove_from_parent_p)
{
  struct varobj_child *vc;
  struct varobj_child *next;

  /* Delete any children of this variable, too. */
  for (vc = var->children; vc != NULL; vc = next)
    {
      if (!remove_from_parent_p)
	vc->child->parent = NULL;
      delete_variable_1 (resultp, delcountp, vc->child, 0, only_children_p);
      next = vc->next;
      xfree (vc);
    }

  /* if we were called to delete only the children we are done here */
  if (only_children_p)
    return;

  /* Otherwise, add it to the list of deleted ones and proceed to do so */
  /* If the name is null, this is a temporary variable, that has not
     yet been installed, don't report it, it belongs to the caller... */
  if (var->obj_name != NULL)
    {
      cppush (resultp, xstrdup (var->obj_name));
      *delcountp = *delcountp + 1;
    }

  /* If this variable has a parent, remove it from its parent's list */
  /* OPTIMIZATION: if the parent of this variable is also being deleted, 
     (as indicated by remove_from_parent_p) we don't bother doing an
     expensive list search to find the element to remove when we are
     discarding the list afterwards */
  if ((remove_from_parent_p) && (var->parent != NULL))
    {
      remove_child_from_parent (var->parent, var);
    }

  if (var->obj_name != NULL)
    uninstall_variable (var);

  /* Free memory associated with this variable */
  free_variable (var);
}

/* Install the given variable VAR with the object name VAR->OBJ_NAME. */
static int
install_variable (struct varobj *var)
{
  struct vlist *cv;
  struct vlist *newvl;
  const char *chp;
  unsigned int index = 0;
  unsigned int i = 1;

  for (chp = var->obj_name; *chp; chp++)
    {
      index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
    }

  cv = *(varobj_table + index);
  while ((cv != NULL) && (strcmp (cv->var->obj_name, var->obj_name) != 0))
    cv = cv->next;

  if (cv != NULL)
    error ("Duplicate variable object name");

  /* Add varobj to hash table */
  newvl = xmalloc (sizeof (struct vlist));
  newvl->next = *(varobj_table + index);
  newvl->var = var;
  *(varobj_table + index) = newvl;

  /* If root, add varobj to root list */
  if (is_root_p (var))
    {
      /* Add to list of root variables */
      if (rootlist == NULL)
	var->root->next = NULL;
      else
	var->root->next = rootlist;
      rootlist = var->root;
      rootcount++;
    }

  return 1;			/* OK */
}

/* Unistall the object VAR. */
static void
uninstall_variable (struct varobj *var)
{
  struct vlist *cv;
  struct vlist *prev;
  struct varobj_root *cr;
  struct varobj_root *prer;
  const char *chp;
  unsigned int index = 0;
  unsigned int i = 1;

  /* Remove varobj from hash table */
  for (chp = var->obj_name; *chp; chp++)
    {
      index = (index + (i++ * (unsigned int) *chp)) % VAROBJ_TABLE_SIZE;
    }

  cv = *(varobj_table + index);
  prev = NULL;
  while ((cv != NULL) && (strcmp (cv->var->obj_name, var->obj_name) != 0))
    {
      prev = cv;
      cv = cv->next;
    }

  if (varobjdebug)
    fprintf_unfiltered (gdb_stdlog, "Deleting %s\n", var->obj_name);

  if (cv == NULL)
    {
      warning
	("Assertion failed: Could not find variable object \"%s\" to delete",
	 var->obj_name);
      return;
    }

  if (prev == NULL)
    *(varobj_table + index) = cv->next;
  else
    prev->next = cv->next;

  xfree (cv);

  /* If root, remove varobj from root list */
  if (is_root_p (var))
    {
      /* Remove from list of root variables */
      if (rootlist == var->root)
	rootlist = var->root->next;
      else
	{
	  prer = NULL;
	  cr = rootlist;
	  while ((cr != NULL) && (cr->rootvar != var))
	    {
	      prer = cr;
	      cr = cr->next;
	    }
	  if (cr == NULL)
	    {
	      warning
		("Assertion failed: Could not find varobj \"%s\" in root list",
		 var->obj_name);
	      return;
	    }
	  if (prer == NULL)
	    rootlist = NULL;
	  else
	    prer->next = cr->next;
	}
      rootcount--;
    }

}

/* Does a child with the index INDEX exist in VAR? If so, return its data.
   If not, return NULL.  NB. The child must already have been installed
   in its parent for this call to work. */

static struct varobj *
child_exists (struct varobj *var, int index)
{
  struct varobj_child *vc;

  for (vc = var->children; vc != NULL; vc = vc->next)
    {
      if (vc->child->index == index)
	return vc->child;
    }

  return NULL;
}

/* Create and install a child of the parent of the given name */
static struct varobj *
create_child (struct varobj *parent, int index, char *name)
{
  struct varobj *child;
  char *childs_name;
  enum varobj_type_change type_changed;
  
  child = new_variable ();

  /* name is allocated by make_name_of_child */
  child->name = name;
  child->index = index;
  child->parent = parent;
  child->root = parent->root;
  xasprintf (&childs_name, "%s.%s", parent->obj_name, name);
  child->obj_name = childs_name;

  if (variable_language (parent) == vlang_cplus
      && name[0] == 'p'
      && ( strcmp ("private", name) == 0
	   || strcmp ("public", name) == 0
	   || strcmp ("protected", name) == 0))
    {
      child->fake_child = 1;
    }
  else 
    {
      child->fake_child = 0;
    }

  install_variable (child);

  /* Save a pointer to this child in the parent */
  save_child_in_parent (parent, child);

  /* Now get the type & value of the child. */
  child->type = type_of_child (child);
  child->value = value_of_child (parent, index, &type_changed);

  if ((!CPLUS_FAKE_CHILD(child) && child->value == NULL) || parent->error)
    child->error = 1;

  return child;
}

/* FIXME: This should be a generic add to list */
/* Save CHILD in the PARENT's data. */
static void
save_child_in_parent (struct varobj *parent, struct varobj *child)
{
  struct varobj_child *vc;

  /* Insert the child at the top */
  vc = parent->children;
  parent->children =
    (struct varobj_child *) xmalloc (sizeof (struct varobj_child));

  parent->children->next = vc;
  parent->children->child = child;
}

/* FIXME: This should be a generic remove from list */
/* Remove the CHILD from the PARENT's list of children. */
static void
remove_child_from_parent (struct varobj *parent, struct varobj *child)
{
  struct varobj_child *vc, *prev;

  /* Find the child in the parent's list */
  prev = NULL;
  for (vc = parent->children; vc != NULL;)
    {
      if (vc->child == child)
	break;
      prev = vc;
      vc = vc->next;
    }

  if (prev == NULL)
    parent->children = vc->next;
  else
    prev->next = vc->next;

}


/*
 * Miscellaneous utility functions.
 */

/* Allocate memory and initialize a new variable */
static struct varobj *
new_variable (void)
{
  struct varobj *var;

  var = (struct varobj *) xmalloc (sizeof (struct varobj));
  var->name = NULL;
  var->obj_name = NULL;
  var->index = -1;
  var->type = NULL;
  var->dynamic_type = NULL;
  var->value = NULL;
  var->error = 0;
  var->num_children = -1;
  var->parent = NULL;
  var->children = NULL;
  var->fake_child = 0;
  var->format = 0;
  var->root = NULL;
  var->updated = 0;

  return var;
}

/* Allocate memory and initialize a new root variable */
static struct varobj *
new_root_variable (void)
{
  struct varobj *var = new_variable ();
  var->root = (struct varobj_root *) xmalloc (sizeof (struct varobj_root));;
  var->root->lang = NULL;
  var->root->exp = NULL;
  var->root->valid_block = NULL;
  var->root->frame = null_frame_id;
  var->root->use_selected_frame = 0;
  var->root->in_scope = 0;
  var->root->rootvar = NULL;

  return var;
}

/* Free any allocated memory associated with VAR. */
static void
free_variable (struct varobj *var)
{
  /* Free the expression if this is a root variable. */
  if (is_root_p (var))
    {
      if (var->root->exp != NULL)
	free_current_contents ((char **) &var->root->exp);
      xfree (var->root);
    }

  xfree (var->name);
  xfree (var->path_expr);
  xfree (var->obj_name);
  xfree (var);
}

static void
do_free_variable_cleanup (void *var)
{
  free_variable (var);
}

static struct cleanup *
make_cleanup_free_variable (struct varobj *var)
{
  return make_cleanup (do_free_variable_cleanup, var);
}

/* This returns the type of the variable. This skips past typedefs
   and returns the real type of the variable. Also, if dynamic_type 
   is set, it will return the full type rather than the base type.

   NOTE: TYPE_TARGET_TYPE should NOT be used anywhere in this file
   except within get_target_type and get_type. 

   APPLE LOCAL:
   JCI: This comment does not seem right to me.  When we get the type of
   a child varobj, where the parent is a struct or a union, we call
   lookup_struct_elt_type.  This directly calls TYPE_TARGET_TYPE, so we
   get the TYPEDEF name, not the resolved name.  This is actually useful,
   since you may want to display two typedef's differently, though their
   base type is the same.  Of course, when you go to make the child of
   one of these child varobj's, you need to resolve the typedef then...

   This comes up below in c_type_of_child, when we are creating children of
   an array type.  There we were calling get_target_type (parent) but that
   obscured the typedef info.  Calling TYPE_TARGET_TYPE directly is more
   useful.
*/

static struct type *
get_type (struct varobj *var)
{
  struct type *type;

  if (varobj_use_dynamic_type && var->dynamic_type != NULL)
    type = var->dynamic_type;
  else
    type = var->type;

  while (type != NULL && TYPE_CODE (type) == TYPE_CODE_TYPEDEF)
    type = TYPE_TARGET_TYPE (type);

  return type;
}

/* This returns the type of the variable, dereferencing pointers, too. 
   If was_ptr non-null, this will also return whether the original
   was a pointer or not. */

static struct type *
get_type_deref (struct varobj *var, int *was_ptr)
{
  struct type *type;

  type = get_type (var);

  if (type != NULL && (TYPE_CODE (type) == TYPE_CODE_PTR
		       || TYPE_CODE (type) == TYPE_CODE_REF))
    {
      type = get_target_type (type);
      if (was_ptr != NULL)
	*was_ptr = 1;
    }
  else if (was_ptr != NULL)
    *was_ptr = 0;

  return type;
}

/* This returns the target type (or NULL) of TYPE, also skipping
   past typedefs, just like get_type ().

   NOTE: TYPE_TARGET_TYPE should NOT be used anywhere in this file
   except within get_target_type and get_type. */
static struct type *
get_target_type (struct type *type)
{
  if (type != NULL)
    {
      type = TYPE_TARGET_TYPE (type);
      while (type != NULL && TYPE_CODE (type) == TYPE_CODE_TYPEDEF)
	type = TYPE_TARGET_TYPE (type);
    }

  return type;
}

/* What is the default display for this variable? We assume that
   everything is "natural". Any exceptions? */
static enum varobj_display_formats
variable_default_display (struct varobj *var)
{
  return FORMAT_NATURAL;
}

/* This function is similar to gdb's value_equal, except that this
   one is "safe" -- it NEVER longjmps. It determines if the VAR's
   value is the same as VAL2. */
static int
my_value_equal (struct value *val1, struct value *val2, int *error2)
{
  int r, err1, err2;

  *error2 = 0;
  /* Special case: NULL values. If both are null, say
     they're equal. */
  if (val1 == NULL && val2 == NULL)
    return 1;
  else if (val1 == NULL || val2 == NULL)
    return 0;

  /* This is bogus, but unfortunately necessary. We must know
     exactly what caused an error -- reading val1 or val2 --  so
     that we can really determine if we think that something has changed. */
  err1 = 0;
  err2 = 0;
  /* We do need to catch errors here because the whole purpose
     is to test if value_equal() has errored */
  if (!gdb_value_equal (val1, val1, &r))
    err1 = 1;

  if (!gdb_value_equal (val2, val2, &r))
    *error2 = err2 = 1;

  if (err1 != err2)
    return 0;

  if (!gdb_value_equal (val1, val2, &r))
    {
      /* An error occurred, this could have happened if
         either val1 or val2 errored. ERR1 and ERR2 tell
         us which of these it is. If both errored, then
         we assume nothing has changed. If one of them is
         valid, though, then something has changed. */
      if (err1 == err2)
	{
	  /* both the old and new values caused errors, so
	     we say the value did not change */
	  /* This is indeterminate, though. Perhaps we should
	     be safe and say, yes, it changed anyway?? */
	  return 1;
	}
      else
	{
	  return 0;
	}
    }

  return r;
}

/* Handle the changelist for varobj_update.  This has two data bits for
   each entry, the varobj, and whether its type has changed. */

static struct varobj_changelist *
varobj_changelist_init ()
{
  struct varobj_changelist *result =
    (struct varobj_changelist *) xmalloc (sizeof (struct varobj_changelist *));

  result->tail = NULL;
  result->head = NULL;
  
  return result;
}

static void
varobj_add_to_changelist (struct varobj_changelist *changelist, 
			  struct varobj *var, 
			  enum varobj_type_change type_changed)
{
  struct varobj_changelist_elem *s;

  s = (struct varobj_changelist_elem *) 
    xmalloc (sizeof (struct varobj_changelist_elem));
  s->var = var;
  s->type_changed = type_changed;
  s->next = NULL;
  if (changelist->head == NULL) 
    {
      changelist->head = s;
      changelist->tail = s;
    }
  else
    {
      changelist->tail->next = s;
      changelist->tail = s;
    }
}

/* pop the next element off of CHANGELIST, and return the varobj,
   and type_changed if necessary.  When the list is empty, return
   NULL, and delete the changelist.  After NULL is returned, you
   can't use the list any more. */

struct varobj *
varobj_changelist_pop (struct varobj_changelist *changelist, 
		       enum varobj_type_change *type_changed)
{
  struct varobj_changelist_elem *s;
  struct varobj *v;

  if (changelist->head == NULL)
    {
      xfree (changelist);
      return NULL;
    }

  s = changelist->head;
  changelist->head = s->next;

  v = s->var;
  if (type_changed != NULL)
    *type_changed = s->type_changed;

  xfree (s);

  return v;
}

/* FIXME: The following should be generic for any pointer */
static void
vpush (struct vstack **pstack, struct varobj *var)
{
  struct vstack *s;

  s = (struct vstack *) xmalloc (sizeof (struct vstack));
  s->var = var;
  s->next = *pstack;
  *pstack = s;
}

/* FIXME: The following should be generic for any pointer */
static struct varobj *
vpop (struct vstack **pstack)
{
  struct vstack *s;
  struct varobj *v;

  if ((*pstack)->var == NULL && (*pstack)->next == NULL)
    return NULL;

  s = *pstack;
  v = s->var;
  *pstack = (*pstack)->next;
  xfree (s);

  return v;
}

/* FIXME: The following should be generic for any pointer */
static void
cppush (struct cpstack **pstack, char *name)
{
  struct cpstack *s;

  s = (struct cpstack *) xmalloc (sizeof (struct cpstack));
  s->name = name;
  s->next = *pstack;
  *pstack = s;
}

/* FIXME: The following should be generic for any pointer */
static char *
cppop (struct cpstack **pstack)
{
  struct cpstack *s;
  char *v;

  if ((*pstack)->name == NULL && (*pstack)->next == NULL)
    return NULL;

  s = *pstack;
  v = s->name;
  *pstack = (*pstack)->next;
  xfree (s);

  return v;
}

/*
 * Language-dependencies
 */

/* Common entry points */

/* Get the language of variable VAR. */
static enum varobj_languages
variable_language (struct varobj *var)
{
  enum varobj_languages lang;

  if (var->root->exp == NULL)
    return vlang_c;

  switch (var->root->exp->language_defn->la_language)
    {
    default:
    case language_c:
      lang = vlang_c;
      break;
    case language_cplus:
      lang = vlang_cplus;
      break;
    case language_java:
      lang = vlang_java;
      break;
    }

  return lang;
}

/* Return the number of children for a given variable.
   The result of this function is defined by the language
   implementation. The number of children returned by this function
   is the number of children that the user will see in the variable
   display. */
static int
number_of_children (struct varobj *var)
{
  return (*var->root->lang->number_of_children) (var);;
}

/* Returns a pointer to the expression for the root varobj VAR? 
   NB call this only on already constructed variables.  */

static char *
name_of_variable (struct varobj *var)
{
  return var->name;
}

/* Returns a pointer to the full rooted expression of varobj VAR.
   If it has not been computed yet, this will compute it */

static char *
path_expr_of_variable (struct varobj *var)
{
  if (var->path_expr != NULL)
    return var->path_expr;
  else if (is_root_p (var))
    return var->name;
  else
    return path_expr_of_child (var->parent, var->index);
}

/* What is the name of the INDEX'th child of VAR? Returns a malloc'd string. */
static char *
make_name_of_child (struct varobj *var, int index)
{
  return (*var->root->lang->make_name_of_child) (var, index);
}

/* What is the rooted expression of the INDEX'th child of VAR? Returns
   a malloc'd string. */
static char *
path_expr_of_child (struct varobj *var, int index)
{
  return (*var->root->lang->path_expr_of_child) (var, index);
}


int
varobj_type_is_equal_p (struct varobj *old_var, struct varobj *new_var)
{
  char *old_type, *new_type;
  int result;
  
  old_type = varobj_get_type (old_var);
  new_type = varobj_get_type (new_var);

  result = (strcmp (old_type, new_type) == 0);

  xfree (old_type);
  xfree (new_type);

  return result;
}

/* What is the ``struct value *'' of the root variable VAR? 

   Returns the current value of VAR_HANDLE.  On return, TYPE_CHANGED
   will be 1 if the type has changed, and 0 otherwise.  Finally, if
   the type has changed in the generic value_of_root code, then the
   old varobj will be discarded, and a new one made for it.  However,
   if the type changed down in the language part of value_of_root
   (possibly because the dynamic type changed, the varobj may just be
   fixed up, so you shouldn't depend on its being replaced or not.  */

static struct value *
value_of_root (struct varobj **var_handle, enum varobj_type_change *type_changed)
{
  struct varobj *var;

  if (var_handle == NULL)
    return NULL;

  var = *var_handle;

  /* This should really be an exception, since this should
     only get called with a root variable. */

  if (var->root->rootvar != var)
    return NULL;

  /* If we have a use_selected_frame variable, we need to reparse the
     expression from scratch to see if it is of a different type, etc.
     Also, if we failed to even get the type of the varobj, we should try
     to recreate the varobj to see if we have gotten past the failure.
     One example where this could happen is if the varobj is an ObjC expression
     which references something that hasn't been initialized yet... In this
     case one of the "lookup implementation for selector & object" functions
     can crash, so we can't even get the type.  */

  if (var->root->use_selected_frame || get_type (var) == NULL)
    {
      struct varobj *tmp_var;

      tmp_var = varobj_create (NULL, name_of_variable (var), (CORE_ADDR) 0, NULL,
			       USE_SELECTED_FRAME);
      /* If there was some error creating the variable, or we couldn't
	 find an expression for this variable, then just return NULL.
	 There is no need to update it if it can't be parsed. */

      if (tmp_var == NULL)
	{
	  return NULL;
	}
      else if (tmp_var->root->exp == NULL)
	{
	  free_variable (tmp_var);
	  return NULL;
	}
      if (varobj_type_is_equal_p (tmp_var, var))
	{
	  if ((var->root->valid_block != NULL 
	       && tmp_var->root->valid_block != NULL)
	      && ((var->root->valid_block->startaddr 
		   != tmp_var->root->valid_block->startaddr)
		  || (var->root->valid_block->endaddr 
		      != tmp_var->root->valid_block->endaddr)))
	    {
	      /* Oops, there is another case here...  What if the variable
		 is shadowed by another of the same name & type, but different
		 block...  Then we need to select the new varobj as well. */
	      var->root->valid_block = tmp_var->root->valid_block;
	    }
	  varobj_delete (tmp_var, NULL, 0);
	  *type_changed = VAROBJ_TYPE_UNCHANGED;
	}
      else
	{
	  tmp_var->obj_name =
	    savestring (var->obj_name, strlen (var->obj_name));
	  varobj_delete (var, NULL, 0);
	  install_variable (tmp_var);
	  *var_handle = tmp_var;
	  var = *var_handle;
	  *type_changed = VAROBJ_TYPE_CHANGED;
	}
    }
  else
    {
      *type_changed = VAROBJ_TYPE_UNCHANGED;
      
      /* We need to make sure that the PC is in the valid block for
	 this variable.  The problem is that gdb will "successfully"
	 evaluate variables that are defined in a block in the current
	 function, even if the pc is not in that block... We need to
	 help the user out in this case. */
      
      if (!varobj_pc_in_valid_block_p (var))
	return NULL;

      /* The other way the type could change is if this is a pointer to
	 something that has a dynamic type, and the dynamic type has changed. */

      
    }
  
  return (*var->root->lang->value_of_root) (var_handle, type_changed);
}

/* varobj_pc_in_valid_block_p returns 1 if the pc for the frame for varobj
   VAR is in within the var's valid block.  Use this to tell whether a
   variable in a block inside a function is in scope. */

int
varobj_pc_in_valid_block_p (struct varobj *var)
{
  struct frame_info *fi;
  CORE_ADDR cur_pc;
  
  /* valid_block is set by innermost_frame, which uses NULL to mean the variable
     was in a global block. */

  if (var->root->valid_block == NULL)
    return 1;
  
  /* reinit_frame_cache (); */
  
  fi = find_frame_addr_in_frame_chain (var->root->frame.base);
  if (fi != NULL)
    {
      cur_pc = get_frame_pc (fi);
      
      if ((cur_pc < var->root->valid_block->startaddr) || 
	  (cur_pc >= var->root->valid_block->endaddr))
	{
	  return 0;
	}
    }
  else
    {
      return 0;
    }

  return 1;
}

/* What is the ``struct value *'' for the INDEX'th child of PARENT? */
static struct value *
value_of_child (struct varobj *parent, int index, 
		enum varobj_type_change *type_changed)
{
  struct value *value;
  struct varobj *child;

  *type_changed = VAROBJ_TYPE_UNCHANGED;

  value = (*parent->root->lang->value_of_child) (parent, index);
  child = child_exists (parent, index);

  if (child == NULL)
    error ("value_of_child called with a NULL child");

  if (value == NULL)
    return value;

  if (!CPLUS_FAKE_CHILD (child))
    {
      struct type *dynamic_type;
      struct value *new_value;

      new_value = varobj_fixup_value (value, varobj_use_dynamic_type, 
				  &dynamic_type);

      /* value_of_child returns a value that has been released.  So if
	 we are going to replace it, we need to free the old value,
	 and release the new one.  */

      if (new_value != value) {
	value_free (value);
	release_value (new_value);
	value = new_value;
      }

      if (dynamic_type != child->dynamic_type)
	{
	  child->dynamic_type = dynamic_type;
	  *type_changed = VAROBJ_DYNAMIC_TYPE_CHANGED;
	}
    }

  /* If we're being lazy, fetch the real value of the variable. */
  if (value != NULL && VALUE_LAZY (value))
    {
      /* If we fail to fetch the value of the child, return
         NULL so that callers notice that we're leaving an
         error message. */
      if (!gdb_value_fetch_lazy (value))
	value = NULL;
    }

  return value;
}

/* What is the type of VAR? */
static struct type *
type_of_child (struct varobj *var)
{

  /* If the child had no evaluation errors, var->value
     will be non-NULL and contain a valid type. */
  if (var->value != NULL)
    return VALUE_TYPE (var->value);

  /* Otherwise, we must compute the type. */
  return (*var->root->lang->type_of_child) (var->parent, var->index);
}

/* Is this variable editable? Use the variable's type to make
   this determination. */
static int
variable_editable (struct varobj *var)
{
  return (*var->root->lang->variable_editable) (var);
}

/* GDB already has a command called "value_of_variable". Sigh. */
static char *
my_value_of_variable (struct varobj *var)
{
  return (*var->root->lang->value_of_variable) (var);
}

/* Is VAR something that can change? Depending on language,
   some variable's values never change. For example,
   struct and unions never change values. */
static int
varobj_value_is_changeable_p (struct varobj *var)
{
  int r;
  struct type *type;

  if (CPLUS_FAKE_CHILD (var))
    return 0;

  type = get_type (var);

  /* If the type is not set (maybe a USE_SELECTED_FRAME 
     variable that hasn't been made yet) then say it
     is unchangeable.  That is safest... */

  if (type == NULL)
    return 0;

  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
    case TYPE_CODE_ARRAY:
      r = 0;
      break;

    default:
      r = 1;
    }

  return r;
}

/* C */
static int
c_number_of_children (struct varobj *var)
{
  struct type *type;
  struct type *target;
  int children;

  type = get_type (var);
  if (type == NULL)
    return -1;

  target = get_target_type (type);
  children = 0;

  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_ARRAY:
      if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (target) > 0
	  && TYPE_ARRAY_UPPER_BOUND_TYPE (type) != BOUND_CANNOT_BE_DETERMINED)
	children = TYPE_LENGTH (type) / TYPE_LENGTH (target);
      else
	children = -1;
      break;

    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      children = TYPE_NFIELDS (type);
      break;

    case TYPE_CODE_PTR:
      /* This is where things get compilcated. All pointers have one child.
         Except, of course, for struct and union ptr, which we automagically
         dereference for the user and function ptrs, which have no children.
         We also don't dereference void* as we don't know what to show.
         We can show char* so we allow it to be dereferenced.  If you decide
         to test for it, please mind that a little magic is necessary to
         properly identify it: char* has TYPE_CODE == TYPE_CODE_INT and 
         TYPE_NAME == "char" */

      switch (TYPE_CODE (target))
	{
	case TYPE_CODE_STRUCT:
	case TYPE_CODE_UNION:
	  children = TYPE_NFIELDS (target);
	  break;

	case TYPE_CODE_FUNC:
	case TYPE_CODE_VOID:
	  children = 0;
	  break;

	default:
	  children = 1;
	}
      break;

    default:
      /* Other types have no children */
      break;
    }

  return children;
}

static char *
c_make_name_of_child (struct varobj *parent, int index)
{
  struct type *type;
  struct type *target;
  char *name;
  char *string;

  type = get_type (parent);
  target = get_target_type (type);

  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_ARRAY:
      xasprintf (&name, "%d", index);
      break;

    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      string = TYPE_FIELD_NAME (type, index);
      name = savestring (string, strlen (string));
      break;

    case TYPE_CODE_PTR:
      switch (TYPE_CODE (target))
	{
	case TYPE_CODE_STRUCT:
	case TYPE_CODE_UNION:
	  string = TYPE_FIELD_NAME (target, index);
	  name = savestring (string, strlen (string));
	  break;

	default:
	  xasprintf (&name, "*%s", parent->name);
	  break;
	}
      break;

    default:
      /* This should not happen */
      name = xstrdup ("???");
    }

  return name;
}

static char *
c_path_expr_of_child (struct varobj *parent, int index)
{
  struct type *type;
  struct type *target;
  char *path_expr;
  struct varobj *child = child_exists (parent, index);
  char *parent_expr;
  char *name;
  int parent_len, child_len, len;

  if (child == NULL)
    error ("c_path_expr_of_child: " 
	   "Tried to get path expression for a null child.");

  parent_expr = path_expr_of_variable (parent);
  name = name_of_variable (child);
  parent_len = strlen (parent_expr);
  child_len = strlen (name);
  len = parent_len + child_len + 2 + 1; /* 2 for (), and 1 for null */

  type = get_type (parent);
  target = get_target_type (type);

  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_ARRAY:
      {
	/* We never get here unless parent->num_children is greater than 0... */
	
	len += 2;
	path_expr = (char *) xmalloc (len);
	sprintf (path_expr, "(%s)[%s]", parent_expr, name);
      }
      break;

    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      len += 1;
      path_expr = (char *) xmalloc (len);
      sprintf (path_expr, "(%s).%s", parent_expr, name);
      break;

    case TYPE_CODE_PTR:
      switch (TYPE_CODE (target))
	{
	case TYPE_CODE_STRUCT:
	case TYPE_CODE_UNION:
	  len += 2;
	  path_expr = (char *) xmalloc (len);
	  sprintf (path_expr, "(%s)->%s", parent_expr, name);
	  break;

	default:
	  len += parent_len + 2 + 1 + 1;
	  path_expr = (char *) xmalloc (len);
	  sprintf (path_expr, "*(%s)", parent_expr);
	  break;
	}
      break;

    default:
      /* This should not happen */
      len = 5;
      path_expr =
	(char *) xmalloc (len);
      sprintf (path_expr, "????");
    }

  child->path_expr = path_expr;
  return path_expr;
}

static struct value *
c_value_of_root (struct varobj **var_handle, enum varobj_type_change *type_changed)
{
  struct value *new_val;
  struct varobj *var = *var_handle;
  struct frame_info *fi;
  int within_scope;
  struct value *ret_value = NULL; 
  
  /*  Only root variables can be updated... */
  if (var->root->rootvar != var)
    /* Not a root var */
    return NULL;


  /* Determine whether the variable is still around. */
  if (var->root->valid_block == NULL)
    within_scope = 1;
  else
    {
      reinit_frame_cache ();
      fi = frame_find_by_id (var->root->frame);
      within_scope = fi != NULL;
      /* FIXME: select_frame could fail */
      if (within_scope)
	select_frame (fi);
    }

  if (within_scope)
    {
      /* We need to catch errors here, because if evaluate
         expression fails we just want to make val->error = 1 and
         go on */
      struct cleanup *schedlock_chain;

      schedlock_chain = make_cleanup_set_restore_scheduler_locking_mode (scheduler_locking_on);

      if (gdb_evaluate_expression (var->root->exp, &new_val))
	{
	  struct type *dynamic_type;
	  new_val = varobj_fixup_value (new_val, varobj_use_dynamic_type, &dynamic_type);
	  if (varobj_use_dynamic_type && (var->dynamic_type != dynamic_type))
	    {
	      *type_changed = VAROBJ_DYNAMIC_TYPE_CHANGED;
	      var->dynamic_type = dynamic_type;

	      /* Probably need to kill the children and reset the number of children... */
	      varobj_delete (var, NULL, 1);
	      var->num_children = number_of_children (var);
	    }

	  if (VALUE_LAZY (new_val))
	    {
	      /* We need to catch errors because if
	         value_fetch_lazy fails we still want to continue
	         (after making val->error = 1) */
	      /* FIXME: Shouldn't be using VALUE_CONTENTS?  The
	         comment on value_fetch_lazy() says it is only
	         called from the macro... */
	      if (!gdb_value_fetch_lazy (new_val))
		var->error = 1;
	      else
		var->error = 0;
	    }
	  release_value (new_val);
	  ret_value = new_val;
	}
      else
	{
	  var->error = 1;
	}
      do_cleanups (schedlock_chain);

    }

  return ret_value;
}

static struct value *
c_value_of_child (struct varobj *parent, int index)
{
  struct value *value;
  struct value *temp;
  struct value *indval;
  struct type *type, *target;
  struct varobj *child;
  char *name;

  type = get_type (parent);
  target = get_target_type (type);
  
  child = child_exists (parent, index);

  if (child == NULL)
    error ("c_value_of_child: called with NULL child");

  name = name_of_variable (child);

  temp = parent->value;
  value = NULL;

  if (temp != NULL)
    {
      switch (TYPE_CODE (type))
	{
	case TYPE_CODE_ARRAY:
#if 0
	  /* This breaks if the array lives in a (vector) register. */
	  value = value_slice (temp, index, 1);
	  temp = value_coerce_array (value);
	  gdb_value_ind (temp, &value);
#else
	  indval = value_from_longest (builtin_type_int, (LONGEST) index);
	  gdb_value_subscript (temp, indval, &value);
#endif
	  break;

	case TYPE_CODE_STRUCT:
	case TYPE_CODE_UNION:
	  gdb_value_struct_elt (NULL, &value, &temp, NULL, name, NULL,
				"vstructure");
	  break;

	case TYPE_CODE_PTR:
	  switch (TYPE_CODE (target))
	    {
	    case TYPE_CODE_STRUCT:
	    case TYPE_CODE_UNION:
	      gdb_value_struct_elt (NULL, &value, &temp, NULL, name, NULL,
				    "vstructure");
	      break;

	    default:
	      /* If we errored out here, then the value is likely
		 bogus.  Release it and return NULL.  Using it
		 can be dangerous.
	      */
	      if (!gdb_value_ind (temp, &value))
		{
		  if (value != NULL)
		    release_value (value);
		  return NULL;
		}
	      break;
	    }
	  break;

	default:
	  break;
	}
    }

  if (value != NULL)
    release_value (value);

  return value;
}

static struct type *
c_type_of_child (struct varobj *parent, int index)
{
  struct type *type;
  struct varobj *child;
  struct type *parent_type = get_type (parent);
  struct type *target_type;

  char *name;

  child = child_exists (parent, index);
  if (child == NULL)
    error ("c_type_of_child: called with a NULL child.");

  name = name_of_variable (child);

  switch (TYPE_CODE (parent_type))
    {
    case TYPE_CODE_ARRAY:
      /* APPLE LOCAL: Don't call get_target_type here, that
	 skips over typedefs, but what the variable was typedef'ed
	 to be is often useful. */
      type = TYPE_TARGET_TYPE (parent->type); 
      /* END APPLE LOCAL */
      break;

    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      type = lookup_struct_elt_type (parent_type, name, 0);
      break;

    case TYPE_CODE_PTR:
      /* Be careful here, this might be a pointer pointing to a typedef, 
	 and we need to get the real thing here or the children will be
	 wrong. */
      target_type = check_typedef (get_target_type (parent_type));
      switch (TYPE_CODE (target_type))
	{
	case TYPE_CODE_STRUCT:
	case TYPE_CODE_UNION:
	  type = lookup_struct_elt_type (target_type, name, 0);
	  break;

	default:
	  type = target_type;
	  break;
	}
      break;

    default:
      /* This should not happen as only the above types have children */
      type = NULL;
      error ("Child of parent: \"%s\" whose type: \"%d\" does not allow children",
	       name_of_variable (parent), TYPE_CODE (parent_type));
      break;
    }

  return type;
}

static int
c_variable_editable (struct varobj *var)
{
  switch (TYPE_CODE (get_type (var)))
    {
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
    case TYPE_CODE_ARRAY:
    case TYPE_CODE_FUNC:
    case TYPE_CODE_MEMBER:
    case TYPE_CODE_METHOD:
      return 0;
      break;

    default:
      return 1;
      break;
    }
}

static char *
c_value_of_variable (struct varobj *var)
{
  /* BOGUS: if val_print sees a struct/class, it will print out its
     children instead of "{...}" */

  switch (TYPE_CODE (get_type (var)))
    {
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      return xstrdup ("{...}");
      /* break; */

    case TYPE_CODE_ARRAY:
      {
	char *number;
	xasprintf (&number, "[%d]", var->num_children);
	return (number);
      }
      /* break; */

    default:
      {
	if (var->value == NULL)
	  {
	    /* This can happen if we attempt to get the value of a struct
	       member when the parent is an invalid pointer. This is an
	       error condition, so we should tell the caller. */
	    return NULL;
	  }
	else
	  {
	    long dummy;
	    struct ui_file *stb = mem_fileopen ();
	    struct cleanup *old_chain = make_cleanup_ui_file_delete (stb);
	    char *thevalue;

	    if (VALUE_LAZY (var->value))
	      gdb_value_fetch_lazy (var->value);
	    val_print (VALUE_TYPE (var->value),
		       VALUE_CONTENTS_RAW (var->value), 0,
		       VALUE_ADDRESS (var->value), stb,
		       format_code[(int) var->format], 1, 0, 0);
	    thevalue = ui_file_xstrdup (stb, &dummy);
	    do_cleanups (old_chain);
	return thevalue;
      }
      }
    }
}


/* C++ */

static int
cplus_number_of_children (struct varobj *var)
{
  struct type *type;
  int children, dont_know;

  dont_know = 1;
  children = 0;

  if (!CPLUS_FAKE_CHILD (var))
    {
      type = get_type_deref (var, NULL);

      if (type == NULL)
	{
	  /* If I can't get the type, I have no hope of
	     counting the children.  Return -1 for not set... */
	  return -1;
	}
      else if (((TYPE_CODE (type)) == TYPE_CODE_STRUCT) 
	       || ((TYPE_CODE (type)) == TYPE_CODE_UNION))
	{
	  int kids[3];
	  
	  cplus_class_num_children (type, kids);
	  if (kids[v_public] != 0)
	    children++;
	  if (kids[v_private] != 0)
	    children++;
	  if (kids[v_protected] != 0)
	    children++;

	  /* Add any baseclasses */
	  children += TYPE_N_BASECLASSES (type);
	  dont_know = 0;

	  /* FIXME: save children in var */
	}
    }
  else
    {
      int kids[3];

      type = get_type_deref (var->parent, NULL);

      cplus_class_num_children (type, kids);
      if (strcmp (name_of_variable (var), "public") == 0)
	children = kids[v_public];
      else if (strcmp (name_of_variable (var), "private") == 0)
	children = kids[v_private];
      else
	children = kids[v_protected];
      dont_know = 0;
    }

  if (dont_know)
    children = c_number_of_children (var);

  return children;
}

/* Compute # of public, private, and protected variables in this class.
   That means we need to descend into all baseclasses and find out
   how many are there, too. */
static void
cplus_class_num_children (struct type *type, int children[3])
{
  int i;

  children[v_public] = 0;
  children[v_private] = 0;
  children[v_protected] = 0;

  for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); i++)
    {
      /* If we have a virtual table pointer, omit it. */
      if (TYPE_VPTR_BASETYPE (type) == type && TYPE_VPTR_FIELDNO (type) == i)
	continue;

      if (TYPE_FIELD_PROTECTED (type, i))
	children[v_protected]++;
      else if (TYPE_FIELD_PRIVATE (type, i))
	children[v_private]++;
      else
	children[v_public]++;
    }
}

/* Compute the index in the type structure TYPE of the NUM'th field
   of protection level PROT */
static int
cplus_real_type_index_for_fake_child_index (struct type *type, 
                                      enum vsections prot, 
                                      int num)
{
  int num_found = 0;
  int foundit = 0;
  int i = 0;

  switch (prot)
    { 
      case v_public:
        for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); i++)
          {
            /* If we have a virtual table pointer, omit it. */
            if (TYPE_VPTR_BASETYPE (type) == type
	        && TYPE_VPTR_FIELDNO (type) == i)
	        continue;

            if (!TYPE_FIELD_PROTECTED (type, i) 
                 && !TYPE_FIELD_PRIVATE (type, i))
              {
                if (num_found == num)
                  {
                    foundit = 1;
                    break;
                  }
                else
	          num_found++;
              }
            }
          break;
      case v_protected:
        for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); i++)
          {
            /* If we have a virtual table pointer, omit it. */
            if (TYPE_VPTR_BASETYPE (type) == type
	        && TYPE_VPTR_FIELDNO (type) == i)
	        continue;

            if (TYPE_FIELD_PROTECTED (type, i))
              {
                if (num_found == num)
                  {
                    foundit = 1;
                    break;
                  }
                else
	          num_found++;
              }
            }
          break;
      case v_private:
        for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); i++)
          {
            /* If we have a virtual table pointer, omit it. */
            if (TYPE_VPTR_BASETYPE (type) == type
	        && TYPE_VPTR_FIELDNO (type) == i)
	        continue;

            if (TYPE_FIELD_PRIVATE (type, i))
              {
                if (num_found == num)
                  {
                    foundit = 1;
                    break;
                  }
                else
	          num_found++;
              }
            }
          break;
    }
    
    if (!foundit)
      return -1;
      
    return i;
 }

static char *
cplus_make_name_of_child (struct varobj *parent, int index)
{
  char *name;
  struct type *type;

  if (CPLUS_FAKE_CHILD (parent))
    {
      /* Looking for children of public, private, or protected. */
      type = get_type_deref (parent->parent, NULL);
    }
  else
    type = get_type_deref (parent, NULL);

  name = NULL;
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      if (CPLUS_FAKE_CHILD (parent))
	{
	  /* The fields of the class type are ordered as they
	     appear in the class.  We are given an index for a
	     particular access control type ("public","protected",
	     or "private").  We must skip over fields that don't
	     have the access control we are looking for to properly
	     find the indexed field. */
	  int type_index = TYPE_N_BASECLASSES (type);
	  if (strcmp (parent->name, "private") == 0)
	    {
	      while (index >= 0)
		{
	  	  if (TYPE_VPTR_BASETYPE (type) == type
	      	      && type_index == TYPE_VPTR_FIELDNO (type))
		    ; /* ignore vptr */
		  else if (TYPE_FIELD_PRIVATE (type, type_index))
		    --index;
		  ++type_index;
		}
	      --type_index;
	    }
	  else if (strcmp (parent->name, "protected") == 0)
	    {
	      while (index >= 0)
		{
	  	  if (TYPE_VPTR_BASETYPE (type) == type
	      	      && type_index == TYPE_VPTR_FIELDNO (type))
		    ; /* ignore vptr */
		  else if (TYPE_FIELD_PROTECTED (type, type_index))
		    --index;
		  ++type_index;
		}
	      --type_index;
	    }
	  else
	    {
	      while (index >= 0)
		{
	  	  if (TYPE_VPTR_BASETYPE (type) == type
	      	      && type_index == TYPE_VPTR_FIELDNO (type))
		    ; /* ignore vptr */
		  else if (!TYPE_FIELD_PRIVATE (type, type_index) &&
		      !TYPE_FIELD_PROTECTED (type, type_index))
		    --index;
		  ++type_index;
		}
	      --type_index;
	    }

	  name = TYPE_FIELD_NAME (type, type_index);
	}
      else if (index < TYPE_N_BASECLASSES (type))
	/* We are looking up the name of a base class */
	name = TYPE_FIELD_NAME (type, index);
      else
	{
	  int children[3];
	  cplus_class_num_children(type, children);

	  /* Everything beyond the baseclasses can
	     only be "public", "private", or "protected"

	     The special "fake" children are always output by varobj in
	     this order. So if INDEX == 2, it MUST be "protected". */
	  index -= TYPE_N_BASECLASSES (type);
          switch (index)
            {
	    case 0:
	      if (children[v_public] > 0)
	 	name = "public";
	      else if (children[v_private] > 0)
	 	name = "private";
	      else 
	 	name = "protected";
	      break;
	    case 1:
	      if (children[v_public] > 0)
		{
		  if (children[v_private] > 0)
		    name = "private";
		  else
		    name = "protected";
		}
	      else if (children[v_private] > 0)
	 	name = "protected";
	      break;
	    case 2:
	      /* Must be protected */
	      name = "protected";
	      break;
	    default:
	      /* error! */
	      break;
            }
            if (name == NULL)
              return NULL;
	}
      break;

    default:
      break;
    }

  if (name == NULL)
    return c_make_name_of_child (parent, index);
  else
    {
      if (name != NULL)
	name = savestring (name, strlen (name));
    }

  return name;
}

static char *
cplus_path_expr_of_child (struct varobj *parent, int index)
{
  char *path_expr;
  struct type *type;
  int children[3];
  struct varobj *child = child_exists (parent, index);
  char *parent_expr = path_expr_of_variable (parent);
  int parent_len = strlen (parent_expr);
  int child_len;
  char *child_name;
  int is_ptr;

  if (child == NULL)
    error ("cplus_path_expr_of_child: " 
	   "Tried to get path expression for a null child.");

  /* The path expression for a fake child is just the parent, 
     that way we can just concatenate the fake child's expr and
     its real children. */

  if (CPLUS_FAKE_CHILD (child))
      return parent_expr;

  if (CPLUS_FAKE_CHILD (parent))
    {
      /* Looking for children of public, private, or protected. */
      type = get_type_deref (parent->parent, &is_ptr);
    }
  else
    type = get_type_deref (parent, &is_ptr);

  path_expr = NULL;
  switch (TYPE_CODE (type))
    {
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      cplus_class_num_children (type, children);

      if (CPLUS_FAKE_CHILD (parent))
	{
          int index_in_type;
          enum vsections prot;
	  char *parent_name = name_of_variable (parent);
          
	  if (strcmp (parent_name, "private") == 0)
            prot = v_private;
          else if (strcmp (parent_name, "protected") == 0)
            prot = v_protected;
	  else if (strcmp (parent_name, "public") == 0)
            prot = v_public;
          else
            {
              error ("cplus_make_name_of_child got a parent with invalid "
		     "fake child name: \"%s\".", parent_name);
              return NULL;
            }

          index_in_type = 
            cplus_real_type_index_for_fake_child_index (type, prot, index);
          
	  child_name = TYPE_FIELD_NAME (type, index_in_type);
	  child_len = strlen (child_name);
	  if (is_ptr)
	    {
	      path_expr = (char *) xmalloc (parent_len + child_len + 2 + 2 + 1);
	      sprintf (path_expr, "(%s)->%s", parent_expr, child_name);
	    }
	  else
	    {
	      path_expr = (char *) xmalloc (parent_len + child_len + 2 + 1 + 1);
	      sprintf (path_expr, "(%s).%s", parent_expr, child_name);
	    }	  
	}
      else if (index < TYPE_N_BASECLASSES (type))
	{
	  child_name = TYPE_FIELD_NAME (type, index);
	  child_len = strlen (child_name);
	  if (is_ptr)
	    {
	      path_expr = (char *) xmalloc (parent_len + 7 + 1);
	      sprintf (path_expr, "((%s *) %s)", child_name, parent_expr);
	    }
	  else
	    {
	      path_expr = (char *) xmalloc (parent_len + 5 + 1);
	      sprintf (path_expr, "((%s) %s)", child_name, parent_expr);
	    }
	}
      else
	{
	  /* Everything beyond the baseclasses can
	     only be "public", "private", or "protected" */
	  index -= TYPE_N_BASECLASSES (type);
	  switch (index)
	    {
	    case 0:
	      if (children[v_public] != 0)
		{
		  path_expr = "public";
		  break;
		}
	    case 1:
	      if (children[v_private] != 0)
		{
		  path_expr = "private";
		  break;
		}
	    case 2:
	      if (children[v_protected] != 0)
		{
		  path_expr = "protected";
		  break;
		}
	    default:
	      /* error! */
	      break;
	    }
	}
      break;

    default:
      break;
    }

  if (path_expr == NULL)
    return c_path_expr_of_child (parent, index);
  else
    {
      child->path_expr = path_expr;
    }

  return path_expr;
}

static struct value *
cplus_value_of_root (struct varobj **var_handle, enum varobj_type_change *type_changed)
{
  return c_value_of_root (var_handle, type_changed);
}

static struct value *
cplus_value_of_child (struct varobj *parent, int index)
{
  struct type *type;
  struct value *value;

  if (CPLUS_FAKE_CHILD (parent))
    type = get_type_deref (parent->parent, NULL);
  else
    type = get_type_deref (parent, NULL);

  value = NULL;

  if (((TYPE_CODE (type)) == TYPE_CODE_STRUCT) ||
      ((TYPE_CODE (type)) == TYPE_CODE_UNION))
    {
      if (CPLUS_FAKE_CHILD (parent))
	{
	  char *name;
	  enum gdb_rc ret_val;
	  struct varobj *child;
	  struct value *temp = parent->parent->value;

	  if (temp == NULL)
	    return NULL;

	  child = child_exists (parent, index);
          if (!child)
            error ("cplus_value_of_child: "
                   "Tried to get the value of a null child.");

	  name = name_of_variable (child);
	  ret_val = gdb_value_struct_elt (NULL, &value, &temp, NULL, 
					  name, NULL,
					  "cplus_structure");
	  if (value != NULL)
	    release_value (value);

	  if (ret_val == RETURN_ERROR)
	    return NULL;
	}
      else if (index >= TYPE_N_BASECLASSES (type))
	{
	  /* public, private, or protected */
	  return NULL;
	}
      else
	{
	  /* Baseclass */
	  if (parent->value != NULL)
	    {
	      struct value *temp = NULL;

	      if (TYPE_CODE (VALUE_TYPE (parent->value)) == TYPE_CODE_PTR)
		{
		  if (!gdb_value_ind (parent->value, &temp))
		    {
		      /* Something went wrong getting the value of the
			 parent, we had better get out of here... */
		      if (temp != NULL)
			release_value (temp);
		      return c_value_of_child (parent, index);
		    }
		}
	      else
		{
		  temp = parent->value;
		}

	      if (temp != NULL)
		{
		  value = value_cast (TYPE_FIELD_TYPE (type, index), temp);
		  release_value (value);
		}
	      else
		{
		  /* We failed to evaluate the parent's value, so don't even
		     bother trying to evaluate this child. */
		  return NULL;
		}
	    }
	}
    }

  if (value == NULL)
    return c_value_of_child (parent, index);

  return value;
}

static struct type *
cplus_type_of_child (struct varobj *parent, int index)
{
  struct type *type, *t;

  if (CPLUS_FAKE_CHILD (parent))
    t = get_type_deref (parent->parent, NULL);
  else
    t = get_type_deref (parent, NULL);

  type = NULL;
  switch (TYPE_CODE (t))
    {
    case TYPE_CODE_STRUCT:
    case TYPE_CODE_UNION:
      if (CPLUS_FAKE_CHILD (parent))
	{
          struct varobj *child = child_exists (parent, index);
	  type = lookup_struct_elt_type (t, name_of_variable (child), 0);
	}
      else if (index < TYPE_N_BASECLASSES (t))
	type = TYPE_FIELD_TYPE (t, index);
      else
	{
	  /* special */
	  return NULL;
	}
      break;

    default:
      break;
    }

  if (type == NULL)
    return c_type_of_child (parent, index);

  return type;
}

static int
cplus_variable_editable (struct varobj *var)
{
  if (CPLUS_FAKE_CHILD (var))
    return 0;

  return c_variable_editable (var);
}

static char *
cplus_value_of_variable (struct varobj *var)
{

  /* If we have one of our special types, don't print out
     any value. */
  if (CPLUS_FAKE_CHILD (var))
    return xstrdup ("");

  return c_value_of_variable (var);
}

/* Java */

static int
java_number_of_children (struct varobj *var)
{
  return cplus_number_of_children (var);
}

static char *
java_make_name_of_child (struct varobj *parent, int index)
{
  char *name, *p;

  name = cplus_make_name_of_child (parent, index);
  /* Escape any periods in the name... */
  p = name;

  while (*p != '\000')
    {
      if (*p == '.')
	*p = '-';
      p++;
    }

  return name;
}

static struct value *
java_value_of_root (struct varobj **var_handle, enum varobj_type_change *type_changed)
{
  return cplus_value_of_root (var_handle, type_changed);
}

static struct value *
java_value_of_child (struct varobj *parent, int index)
{
  return cplus_value_of_child (parent, index);
}

static struct type *
java_type_of_child (struct varobj *parent, int index)
{
  return cplus_type_of_child (parent, index);
}

static int
java_variable_editable (struct varobj *var)
{
  return cplus_variable_editable (var);
}

static char *
java_value_of_variable (struct varobj *var)
{
  return cplus_value_of_variable (var);
}
static char *
java_path_expr_of_child (struct varobj *parent, int index)
{
  return cplus_path_expr_of_child (parent, index);
}

extern void _initialize_varobj (void);
void
_initialize_varobj (void)
{
  int sizeof_table = sizeof (struct vlist *) * VAROBJ_TABLE_SIZE;

  varobj_table = xmalloc (sizeof_table);
  memset (varobj_table, 0, sizeof_table);

  add_show_from_set (add_set_cmd ("debugvarobj", class_maintenance, var_zinteger, 
				  (char *) &varobjdebug, "Set varobj debugging.\n\
When non-zero, varobj debugging is enabled.", &setlist),
		     &showlist);
  add_show_from_set (add_set_cmd ("varobj-print-object", class_obscure, var_boolean, 
				  (char *) &varobj_use_dynamic_type, "Set varobj to construct "
				  "children using the most specific class type.", &setlist),
		     &showlist);

  add_show_from_set (add_set_cmd ("varobj-runs-all-threads", class_obscure, var_boolean, 
				  (char *) &varobj_runs_all_threads, "Set to run all threads "
				  "when evaluating varobjs.", &setlist),
		     &showlist);
				 
}