xref: /freebsd-9.3-release/contrib/gdb/gdb/cp-abi.h

/* Abstraction of various C++ ABI's we support, and the info we need
   to get from them.
   Contributed by Daniel Berlin <dberlin@redhat.com>
   Copyright 2001 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 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.  */

#ifndef CP_ABI_H_
#define CP_ABI_H_ 1

struct fn_field;
struct type;
struct value;

/* The functions here that attempt to determine what sort of thing a
   mangled name refers to may well be revised in the future.  It would
   certainly be cleaner to carry this information explicitly in GDB's
   data structures than to derive it from the mangled name.  */


/* Kinds of constructors.  All these values are guaranteed to be
   non-zero.  */
enum ctor_kinds {

  /* Initialize a complete object, including virtual bases, using
     memory provided by caller.  */
  complete_object_ctor = 1,

  /* Initialize a base object of some larger object.  */
  base_object_ctor,

  /* An allocating complete-object constructor.  */
  complete_object_allocating_ctor
};

/* Return non-zero iff NAME is the mangled name of a constructor.
   Actually, return an `enum ctor_kind' value describing what *kind*
   of constructor it is.  */
extern enum ctor_kinds is_constructor_name (const char *name);


/* Kinds of destructors.  All these values are guaranteed to be
   non-zero.  */
enum dtor_kinds {

  /* A destructor which finalizes the entire object, and then calls
     `delete' on its storage.  */
  deleting_dtor = 1,

  /* A destructor which finalizes the entire object, but does not call
     `delete'.  */
  complete_object_dtor,

  /* A destructor which finalizes a subobject of some larger object.  */
  base_object_dtor
};

/* Return non-zero iff NAME is the mangled name of a destructor.
   Actually, return an `enum dtor_kind' value describing what *kind*
   of destructor it is.  */
extern enum dtor_kinds is_destructor_name (const char *name);


/* Return non-zero iff NAME is the mangled name of a vtable.  */
extern int is_vtable_name (const char *name);


/* Return non-zero iff NAME is the un-mangled name of an operator,
   perhaps scoped within some class.  */
extern int is_operator_name (const char *name);


/* Return an object's virtual function as a value.

   VALUEP is a pointer to a pointer to a value, holding the object
   whose virtual function we want to invoke.  If the ABI requires a
   virtual function's caller to adjust the `this' pointer by an amount
   retrieved from the vtable before invoking the function (i.e., we're
   not using "vtable thunks" to do the adjustment automatically), then
   this function may set *VALUEP to point to a new object with an
   appropriately tweaked address.

   The J'th element of the overload set F is the virtual function of
   *VALUEP we want to invoke.

   TYPE is the base type of *VALUEP whose method we're invoking ---
   this is the type containing F.  OFFSET is the offset of that base
   type within *VALUEP.  */
extern struct value *value_virtual_fn_field (struct value **valuep,
					     struct fn_field *f, int j,
					     struct type *type, int offset);


/* Try to find the run-time type of VALUE, using C++ run-time type
   information.  Return the run-time type, or zero if we can't figure
   it out.

   If we do find the run-time type:
   - Set *FULL to non-zero if VALUE already contains the complete
     run-time object, not just some embedded base class of the object.
   - Set *TOP and *USING_ENC to indicate where the enclosing object
     starts relative to VALUE:
     - If *USING_ENC is zero, then *TOP is the offset from the start
       of the complete object to the start of the embedded subobject
       VALUE represents.  In other words, the enclosing object starts
       at VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) +
       VALUE_EMBEDDED_OFFSET (VALUE) + *TOP
     - If *USING_ENC is non-zero, then *TOP is the offset from the
       address of the complete object to the enclosing object stored
       in VALUE.  In other words, the enclosing object starts at
       VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) + *TOP.
     If VALUE's type and enclosing type are the same, then these two
     cases are equivalent.

   FULL, TOP, and USING_ENC can each be zero, in which case we don't
   provide the corresponding piece of information.  */
extern struct type *value_rtti_type (struct value *value,
                                     int *full, int *top, int *using_enc);

/* Compute the offset of the baseclass which is
   the INDEXth baseclass of class TYPE,
   for value at VALADDR (in host) at ADDRESS (in target).
   The result is the offset of the baseclass value relative
   to (the address of)(ARG) + OFFSET.

   -1 is returned on error. */

extern int baseclass_offset (struct type *type, int index, char *valaddr,
			     CORE_ADDR address);

struct cp_abi_ops
{
  const char *shortname;
  const char *longname;
  const char *doc;

  /* ABI-specific implementations for the functions declared above.  */
  enum ctor_kinds (*is_constructor_name) (const char *name);
  enum dtor_kinds (*is_destructor_name) (const char *name);
  int (*is_vtable_name) (const char *name);
  int (*is_operator_name) (const char *name);
  struct value *(*virtual_fn_field) (struct value **arg1p, struct fn_field * f,
				     int j, struct type * type, int offset);
  struct type *(*rtti_type) (struct value *v, int *full, int *top,
			     int *using_enc);
  int (*baseclass_offset) (struct type *type, int index, char *valaddr,
			   CORE_ADDR address);
};


extern int register_cp_abi (struct cp_abi_ops *abi);
extern void set_cp_abi_as_auto_default (const char *short_name);

#endif