gdb/cp-abi.h

   1 /* Abstraction of various C++ ABI's we support, and the info we need
   2    to get from them.
   3    Contributed by Daniel Berlin <dberlin@redhat.com>
   4    Copyright 2001 Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or
   9    modify
  10    it under the terms of the GNU General Public License as published
  11    by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 59 Temple Place - Suite 330,
  23    Boston, MA 02111-1307, USA.  */
  24
  25 #ifndef CP_ABI_H_
  26 #define CP_ABI_H_ 1
  27
  28 struct fn_field;
  29 struct type;
  30 struct value;
  31
  32 /* The functions here that attempt to determine what sort of thing a
  33    mangled name refers to may well be revised in the future.  It would
  34    certainly be cleaner to carry this information explicitly in GDB's
  35    data structures than to derive it from the mangled name.  */
  36
  37
  38 /* Kinds of constructors.  All these values are guaranteed to be
  39    non-zero.  */
  40 enum ctor_kinds {
  41
  42   /* Initialize a complete object, including virtual bases, using
  43      memory provided by caller.  */
  44   complete_object_ctor = 1,
  45
  46   /* Initialize a base object of some larger object.  */
  47   base_object_ctor,
  48
  49   /* An allocating complete-object constructor.  */
  50   complete_object_allocating_ctor
  51 };
  52
  53 /* Return non-zero iff NAME is the mangled name of a constructor.
  54    Actually, return an `enum ctor_kind' value describing what *kind*
  55    of constructor it is.  */
  56 extern enum ctor_kinds is_constructor_name (const char *name);
  57
  58
  59 /* Kinds of destructors.  All these values are guaranteed to be
  60    non-zero.  */
  61 enum dtor_kinds {
  62
  63   /* A destructor which finalizes the entire object, and then calls
  64      `delete' on its storage.  */
  65   deleting_dtor = 1,
  66
  67   /* A destructor which finalizes the entire object, but does not call
  68      `delete'.  */
  69   complete_object_dtor,
  70
  71   /* A destructor which finalizes a subobject of some larger object.  */
  72   base_object_dtor
  73 };
  74
  75 /* Return non-zero iff NAME is the mangled name of a destructor.
  76    Actually, return an `enum dtor_kind' value describing what *kind*
  77    of destructor it is.  */
  78 extern enum dtor_kinds is_destructor_name (const char *name);
  79
  80
  81 /* Return non-zero iff NAME is the mangled name of a vtable.  */
  82 extern int is_vtable_name (const char *name);
  83
  84
  85 /* Return non-zero iff NAME is the un-mangled name of an operator,
  86    perhaps scoped within some class.  */
  87 extern int is_operator_name (const char *name);
  88
  89
  90 /* Return an object's virtual function as a value.
  91
  92    VALUEP is a pointer to a pointer to a value, holding the object
  93    whose virtual function we want to invoke.  If the ABI requires a
  94    virtual function's caller to adjust the `this' pointer by an amount
  95    retrieved from the vtable before invoking the function (i.e., we're
  96    not using "vtable thunks" to do the adjustment automatically), then
  97    this function may set *VALUEP to point to a new object with an
  98    appropriately tweaked address.
  99
 100    The J'th element of the overload set F is the virtual function of
 101    *VALUEP we want to invoke.
 102
 103    TYPE is the base type of *VALUEP whose method we're invoking ---
 104    this is the type containing F.  OFFSET is the offset of that base
 105    type within *VALUEP.  */
 106 extern struct value *value_virtual_fn_field (struct value **valuep,
 107                                              struct fn_field *f, int j,
 108                                              struct type *type, int offset);
 109
 110
 111 /* Try to find the run-time type of VALUE, using C++ run-time type
 112    information.  Return the run-time type, or zero if we can't figure
 113    it out.
 114
 115    If we do find the run-time type:
 116    - Set *FULL to non-zero if VALUE already contains the complete
 117      run-time object, not just some embedded base class of the object.
 118    - Set *TOP and *USING_ENC to indicate where the enclosing object
 119      starts relative to VALUE:
 120      - If *USING_ENC is zero, then *TOP is the offset from the start
 121        of the complete object to the start of the embedded subobject
 122        VALUE represents.  In other words, the enclosing object starts
 123        at VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) +
 124        VALUE_EMBEDDED_OFFSET (VALUE) + *TOP
 125      - If *USING_ENC is non-zero, then *TOP is the offset from the
 126        address of the complete object to the enclosing object stored
 127        in VALUE.  In other words, the enclosing object starts at
 128        VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) + *TOP.
 129      If VALUE's type and enclosing type are the same, then these two
 130      cases are equivalent.
 131
 132    FULL, TOP, and USING_ENC can each be zero, in which case we don't
 133    provide the corresponding piece of information.  */
 134 extern struct type *value_rtti_type (struct value *value,
 135                                      int *full, int *top, int *using_enc);
 136
 137 /* Compute the offset of the baseclass which is
 138    the INDEXth baseclass of class TYPE,
 139    for value at VALADDR (in host) at ADDRESS (in target).
 140    The result is the offset of the baseclass value relative
 141    to (the address of)(ARG) + OFFSET.
 142
 143    -1 is returned on error. */
 144
 145 extern int baseclass_offset (struct type *type, int index, char *valaddr,
 146                              CORE_ADDR address);
 147
 148 struct cp_abi_ops
 149 {
 150   const char *shortname;
 151   const char *longname;
 152   const char *doc;
 153
 154   /* ABI-specific implementations for the functions declared above.  */
 155   enum ctor_kinds (*is_constructor_name) (const char *name);
 156   enum dtor_kinds (*is_destructor_name) (const char *name);
 157   int (*is_vtable_name) (const char *name);
 158   int (*is_operator_name) (const char *name);
 159   struct value *(*virtual_fn_field) (struct value **arg1p, struct fn_field * f,
 160                                      int j, struct type * type, int offset);
 161   struct type *(*rtti_type) (struct value *v, int *full, int *top,
 162                              int *using_enc);
 163   int (*baseclass_offset) (struct type *type, int index, char *valaddr,
 164                            CORE_ADDR address);
 165 };
 166
 167
 168 extern int register_cp_abi (struct cp_abi_ops *abi);
 169 extern void set_cp_abi_as_auto_default (const char *short_name);
 170
 171 #endif
 172