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 /* The functions here that attempt to determine what sort of thing a
  29    mangled name refers to may well be revised in the future.  It would
  30    certainly be cleaner to carry this information explicitly in GDB's
  31    data structures than to derive it from the mangled name.  */
  32
  33
  34 /* Kinds of constructors.  All these values are guaranteed to be
  35    non-zero.  */
  36 enum ctor_kinds {
  37
  38   /* Initialize a complete object, including virtual bases, using
  39      memory provided by caller.  */
  40   complete_object_ctor = 1,
  41
  42   /* Initialize a base object of some larger object.  */
  43   base_object_ctor,
  44
  45   /* An allocating complete-object constructor.  */
  46   complete_object_allocating_ctor
  47 };
  48
  49 /* Return non-zero iff NAME is the mangled name of a constructor.
  50    Actually, return an `enum ctor_kind' value describing what *kind*
  51    of constructor it is.  */
  52 extern enum ctor_kinds is_constructor_name (const char *name);
  53
  54
  55 /* Kinds of destructors.  All these values are guaranteed to be
  56    non-zero.  */
  57 enum dtor_kinds {
  58
  59   /* A destructor which finalizes the entire object, and then calls
  60      `delete' on its storage.  */
  61   deleting_dtor = 1,
  62
  63   /* A destructor which finalizes the entire object, but does not call
  64      `delete'.  */
  65   complete_object_dtor,
  66
  67   /* A destructor which finalizes a subobject of some larger object.  */
  68   base_object_dtor
  69 };
  70
  71 /* Return non-zero iff NAME is the mangled name of a destructor.
  72    Actually, return an `enum dtor_kind' value describing what *kind*
  73    of destructor it is.  */
  74 extern enum dtor_kinds is_destructor_name (const char *name);
  75
  76
  77 /* Return non-zero iff NAME is the mangled name of a vtable.  */
  78 extern int is_vtable_name (const char *name);
  79
  80
  81 /* Return non-zero iff NAME is the un-mangled name of an operator,
  82    perhaps scoped within some class.  */
  83 extern int is_operator_name (const char *name);
  84
  85
  86 /* Return an object's virtual function as a value.
  87
  88    VALUEP is a pointer to a pointer to a value, holding the object
  89    whose virtual function we want to invoke.  If the ABI requires a
  90    virtual function's caller to adjust the `this' pointer by an amount
  91    retrieved from the vtable before invoking the function (i.e., we're
  92    not using "vtable thunks" to do the adjustment automatically), then
  93    this function may set *VALUEP to point to a new object with an
  94    appropriately tweaked address.
  95
  96    The J'th element of the overload set F is the virtual function of
  97    *VALUEP we want to invoke.
  98
  99    TYPE is the base type of *VALUEP whose method we're invoking ---
 100    this is the type containing F.  OFFSET is the offset of that base
 101    type within *VALUEP.  */
 102 extern value_ptr value_virtual_fn_field (value_ptr *valuep,
 103                                          struct fn_field *f, int j,
 104                                          struct type *type, int offset);
 105
 106
 107 /* Try to find the run-time type of VALUE, using C++ run-time type
 108    information.  Return the run-time type, or zero if we can't figure
 109    it out.
 110
 111    If we do find the run-time type:
 112    - Set *FULL to non-zero if VALUE already contains the complete
 113      run-time object, not just some embedded base class of the object.
 114    - Set *TOP and *USING_ENC to indicate where the enclosing object
 115      starts relative to VALUE:
 116      - If *USING_ENC is zero, then *TOP is the offset from the start
 117        of the complete object to the start of the embedded subobject
 118        VALUE represents.  In other words, the enclosing object starts
 119        at VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) +
 120        VALUE_EMBEDDED_OFFSET (VALUE) + *TOP
 121      - If *USING_ENC is non-zero, then *TOP is the offset from the
 122        address of the complete object to the enclosing object stored
 123        in VALUE.  In other words, the enclosing object starts at
 124        VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) + *TOP.
 125      If VALUE's type and enclosing type are the same, then these two
 126      cases are equivalent.
 127
 128    FULL, TOP, and USING_ENC can each be zero, in which case we don't
 129    provide the corresponding piece of information.  */
 130 extern struct type *value_rtti_type (struct value *value,
 131                                      int *full, int *top, int *using_enc);
 132
 133
 134 struct cp_abi_ops
 135 {
 136   const char *shortname;
 137   const char *longname;
 138   const char *doc;
 139
 140   /* ABI-specific implementations for the functions declared above.  */
 141   enum ctor_kinds (*is_constructor_name) (const char *name);
 142   enum dtor_kinds (*is_destructor_name) (const char *name);
 143   int (*is_vtable_name) (const char *name);
 144   int (*is_operator_name) (const char *name);
 145   value_ptr (*virtual_fn_field) (value_ptr * arg1p, struct fn_field * f,
 146                                  int j, struct type * type, int offset);
 147   struct type *(*rtti_type) (value_ptr v, int *full, int *top,
 148                              int *using_enc);
 149 };
 150
 151
 152 extern struct cp_abi_ops *cp_abis;
 153 extern int num_cp_abis;
 154 extern struct cp_abi_ops current_cp_abi;
 155 extern int register_cp_abi (struct cp_abi_ops abi);
 156 extern int switch_to_cp_abi (const char *short_name);
 157
 158 #endif
 159