gdb/cp-abi.h

   1 /* Abstraction of various C++ ABI's we support, and the info we need
   2    to get from them.
   3
   4    Contributed by Daniel Berlin <dberlin@redhat.com>
   5
   6    Copyright (C) 2001, 2005 Free Software Foundation, Inc.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or
  11    modify
  12    it under the terms of the GNU General Public License as published
  13    by
  14    the Free Software Foundation; either version 2 of the License, or
  15    (at your option) any later version.
  16
  17    This program is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20    GNU General Public License for more details.
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software
  24    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25    Boston, MA 02110-1301, USA.  */
  26
  27 #ifndef CP_ABI_H_
  28 #define CP_ABI_H_ 1
  29
  30 struct fn_field;
  31 struct type;
  32 struct value;
  33
  34 /* The functions here that attempt to determine what sort of thing a
  35    mangled name refers to may well be revised in the future.  It would
  36    certainly be cleaner to carry this information explicitly in GDB's
  37    data structures than to derive it from the mangled name.  */
  38
  39
  40 /* Kinds of constructors.  All these values are guaranteed to be
  41    non-zero.  */
  42 enum ctor_kinds {
  43
  44   /* Initialize a complete object, including virtual bases, using
  45      memory provided by caller.  */
  46   complete_object_ctor = 1,
  47
  48   /* Initialize a base object of some larger object.  */
  49   base_object_ctor,
  50
  51   /* An allocating complete-object constructor.  */
  52   complete_object_allocating_ctor
  53 };
  54
  55 /* Return non-zero iff NAME is the mangled name of a constructor.
  56    Actually, return an `enum ctor_kind' value describing what *kind*
  57    of constructor it is.  */
  58 extern enum ctor_kinds is_constructor_name (const char *name);
  59
  60
  61 /* Kinds of destructors.  All these values are guaranteed to be
  62    non-zero.  */
  63 enum dtor_kinds {
  64
  65   /* A destructor which finalizes the entire object, and then calls
  66      `delete' on its storage.  */
  67   deleting_dtor = 1,
  68
  69   /* A destructor which finalizes the entire object, but does not call
  70      `delete'.  */
  71   complete_object_dtor,
  72
  73   /* A destructor which finalizes a subobject of some larger object.  */
  74   base_object_dtor
  75 };
  76
  77 /* Return non-zero iff NAME is the mangled name of a destructor.
  78    Actually, return an `enum dtor_kind' value describing what *kind*
  79    of destructor it is.  */
  80 extern enum dtor_kinds is_destructor_name (const char *name);
  81
  82
  83 /* Return non-zero iff NAME is the mangled name of a vtable.  */
  84 extern int is_vtable_name (const char *name);
  85
  86
  87 /* Return non-zero iff NAME is the un-mangled name of an operator,
  88    perhaps scoped within some class.  */
  89 extern int is_operator_name (const char *name);
  90
  91
  92 /* Return an object's virtual function as a value.
  93
  94    VALUEP is a pointer to a pointer to a value, holding the object
  95    whose virtual function we want to invoke.  If the ABI requires a
  96    virtual function's caller to adjust the `this' pointer by an amount
  97    retrieved from the vtable before invoking the function (i.e., we're
  98    not using "vtable thunks" to do the adjustment automatically), then
  99    this function may set *VALUEP to point to a new object with an
 100    appropriately tweaked address.
 101
 102    The J'th element of the overload set F is the virtual function of
 103    *VALUEP we want to invoke.
 104
 105    TYPE is the base type of *VALUEP whose method we're invoking ---
 106    this is the type containing F.  OFFSET is the offset of that base
 107    type within *VALUEP.  */
 108 extern struct value *value_virtual_fn_field (struct value **valuep,
 109                                              struct fn_field *f, int j,
 110                                              struct type *type, int offset);
 111
 112
 113 /* Try to find the run-time type of VALUE, using C++ run-time type
 114    information.  Return the run-time type, or zero if we can't figure
 115    it out.
 116
 117    If we do find the run-time type:
 118    - Set *FULL to non-zero if VALUE already contains the complete
 119      run-time object, not just some embedded base class of the object.
 120    - Set *TOP and *USING_ENC to indicate where the enclosing object
 121      starts relative to VALUE:
 122      - If *USING_ENC is zero, then *TOP is the offset from the start
 123        of the complete object to the start of the embedded subobject
 124        VALUE represents.  In other words, the enclosing object starts
 125        at VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) +
 126        value_embedded_offset (VALUE) + *TOP
 127      - If *USING_ENC is non-zero, then *TOP is the offset from the
 128        address of the complete object to the enclosing object stored
 129        in VALUE.  In other words, the enclosing object starts at
 130        VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) + *TOP.
 131      If VALUE's type and enclosing type are the same, then these two
 132      cases are equivalent.
 133
 134    FULL, TOP, and USING_ENC can each be zero, in which case we don't
 135    provide the corresponding piece of information.  */
 136 extern struct type *value_rtti_type (struct value *value,
 137                                      int *full, int *top, int *using_enc);
 138
 139 /* Compute the offset of the baseclass which is
 140    the INDEXth baseclass of class TYPE,
 141    for value at VALADDR (in host) at ADDRESS (in target).
 142    The result is the offset of the baseclass value relative
 143    to (the address of)(ARG) + OFFSET.
 144
 145    -1 is returned on error. */
 146
 147 extern int baseclass_offset (struct type *type, int index,
 148                              const bfd_byte *valaddr, CORE_ADDR address);
 149
 150 struct cp_abi_ops
 151 {
 152   const char *shortname;
 153   const char *longname;
 154   const char *doc;
 155
 156   /* ABI-specific implementations for the functions declared above.  */
 157   enum ctor_kinds (*is_constructor_name) (const char *name);
 158   enum dtor_kinds (*is_destructor_name) (const char *name);
 159   int (*is_vtable_name) (const char *name);
 160   int (*is_operator_name) (const char *name);
 161   struct value *(*virtual_fn_field) (struct value **arg1p, struct fn_field * f,
 162                                      int j, struct type * type, int offset);
 163   struct type *(*rtti_type) (struct value *v, int *full, int *top,
 164                              int *using_enc);
 165   int (*baseclass_offset) (struct type *type, int index,
 166                            const bfd_byte *valaddr, CORE_ADDR address);
 167 };
 168
 169
 170 extern int register_cp_abi (struct cp_abi_ops *abi);
 171 extern void set_cp_abi_as_auto_default (const char *short_name);
 172
 173 #endif
 174