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, 2006 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 struct ui_file;
  34
  35 /* The functions here that attempt to determine what sort of thing a
  36    mangled name refers to may well be revised in the future.  It would
  37    certainly be cleaner to carry this information explicitly in GDB's
  38    data structures than to derive it from the mangled name.  */
  39
  40
  41 /* Kinds of constructors.  All these values are guaranteed to be
  42    non-zero.  */
  43 enum ctor_kinds {
  44
  45   /* Initialize a complete object, including virtual bases, using
  46      memory provided by caller.  */
  47   complete_object_ctor = 1,
  48
  49   /* Initialize a base object of some larger object.  */
  50   base_object_ctor,
  51
  52   /* An allocating complete-object constructor.  */
  53   complete_object_allocating_ctor
  54 };
  55
  56 /* Return non-zero iff NAME is the mangled name of a constructor.
  57    Actually, return an `enum ctor_kind' value describing what *kind*
  58    of constructor it is.  */
  59 extern enum ctor_kinds is_constructor_name (const char *name);
  60
  61
  62 /* Kinds of destructors.  All these values are guaranteed to be
  63    non-zero.  */
  64 enum dtor_kinds {
  65
  66   /* A destructor which finalizes the entire object, and then calls
  67      `delete' on its storage.  */
  68   deleting_dtor = 1,
  69
  70   /* A destructor which finalizes the entire object, but does not call
  71      `delete'.  */
  72   complete_object_dtor,
  73
  74   /* A destructor which finalizes a subobject of some larger object.  */
  75   base_object_dtor
  76 };
  77
  78 /* Return non-zero iff NAME is the mangled name of a destructor.
  79    Actually, return an `enum dtor_kind' value describing what *kind*
  80    of destructor it is.  */
  81 extern enum dtor_kinds is_destructor_name (const char *name);
  82
  83
  84 /* Return non-zero iff NAME is the mangled name of a vtable.  */
  85 extern int is_vtable_name (const char *name);
  86
  87
  88 /* Return non-zero iff NAME is the un-mangled name of an operator,
  89    perhaps scoped within some class.  */
  90 extern int is_operator_name (const char *name);
  91
  92
  93 /* Return an object's virtual function as a value.
  94
  95    VALUEP is a pointer to a pointer to a value, holding the object
  96    whose virtual function we want to invoke.  If the ABI requires a
  97    virtual function's caller to adjust the `this' pointer by an amount
  98    retrieved from the vtable before invoking the function (i.e., we're
  99    not using "vtable thunks" to do the adjustment automatically), then
 100    this function may set *VALUEP to point to a new object with an
 101    appropriately tweaked address.
 102
 103    The J'th element of the overload set F is the virtual function of
 104    *VALUEP we want to invoke.
 105
 106    TYPE is the base type of *VALUEP whose method we're invoking ---
 107    this is the type containing F.  OFFSET is the offset of that base
 108    type within *VALUEP.  */
 109 extern struct value *value_virtual_fn_field (struct value **valuep,
 110                                              struct fn_field *f, int j,
 111                                              struct type *type, int offset);
 112
 113
 114 /* Try to find the run-time type of VALUE, using C++ run-time type
 115    information.  Return the run-time type, or zero if we can't figure
 116    it out.
 117
 118    If we do find the run-time type:
 119    - Set *FULL to non-zero if VALUE already contains the complete
 120      run-time object, not just some embedded base class of the object.
 121    - Set *TOP and *USING_ENC to indicate where the enclosing object
 122      starts relative to VALUE:
 123      - If *USING_ENC is zero, then *TOP is the offset from the start
 124        of the complete object to the start of the embedded subobject
 125        VALUE represents.  In other words, the enclosing object starts
 126        at VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) +
 127        value_embedded_offset (VALUE) + *TOP
 128      - If *USING_ENC is non-zero, then *TOP is the offset from the
 129        address of the complete object to the enclosing object stored
 130        in VALUE.  In other words, the enclosing object starts at
 131        VALUE_ADDR (VALUE) + VALUE_OFFSET (VALUE) + *TOP.
 132      If VALUE's type and enclosing type are the same, then these two
 133      cases are equivalent.
 134
 135    FULL, TOP, and USING_ENC can each be zero, in which case we don't
 136    provide the corresponding piece of information.  */
 137 extern struct type *value_rtti_type (struct value *value,
 138                                      int *full, int *top, int *using_enc);
 139
 140 /* Compute the offset of the baseclass which is
 141    the INDEXth baseclass of class TYPE,
 142    for value at VALADDR (in host) at ADDRESS (in target).
 143    The result is the offset of the baseclass value relative
 144    to (the address of)(ARG) + OFFSET.
 145
 146    -1 is returned on error. */
 147
 148 extern int baseclass_offset (struct type *type, int index,
 149                              const bfd_byte *valaddr, CORE_ADDR address);
 150
 151 /* Describe the target of a pointer to method.  CONTENTS is the byte
 152    pattern representing the pointer to method.  TYPE is the pointer to
 153    method type.  STREAM is the stream to print it to.  */
 154 void cplus_print_method_ptr (const gdb_byte *contents, struct type *type,
 155                              struct ui_file *stream);
 156
 157 /* Return the size of a pointer to member function for the current
 158    architecture.  */
 159 int cplus_method_ptr_size (void);
 160
 161 /* Return the method which should be called by applying METHOD_PTR
 162    to *THIS_P, and adjust *THIS_P if necessary.  */
 163 struct value *cplus_method_ptr_to_value (struct value **this_p,
 164                                          struct value *method_ptr);
 165
 166 /* Create the byte pattern in CONTENTS representing a pointer to
 167    member function at ADDRESS (if IS_VIRTUAL is 0) or with virtual
 168    table offset ADDRESS (if IS_VIRTUAL is 1).  This is the opposite
 169    of cplus_method_ptr_to_value.  */
 170 void cplus_make_method_ptr (gdb_byte *CONTENTS, CORE_ADDR address,
 171                             int is_virtual);
 172
 173 struct cp_abi_ops
 174 {
 175   const char *shortname;
 176   const char *longname;
 177   const char *doc;
 178
 179   /* ABI-specific implementations for the functions declared above.  */
 180   enum ctor_kinds (*is_constructor_name) (const char *name);
 181   enum dtor_kinds (*is_destructor_name) (const char *name);
 182   int (*is_vtable_name) (const char *name);
 183   int (*is_operator_name) (const char *name);
 184   struct value *(*virtual_fn_field) (struct value **arg1p, struct fn_field * f,
 185                                      int j, struct type * type, int offset);
 186   struct type *(*rtti_type) (struct value *v, int *full, int *top,
 187                              int *using_enc);
 188   int (*baseclass_offset) (struct type *type, int index,
 189                            const bfd_byte *valaddr, CORE_ADDR address);
 190   void (*print_method_ptr) (const gdb_byte *contents, struct type *type,
 191                             struct ui_file *stream);
 192   int (*method_ptr_size) (void);
 193   void (*make_method_ptr) (gdb_byte *, CORE_ADDR, int);
 194   struct value * (*method_ptr_to_value) (struct value **, struct value *);
 195 };
 196
 197
 198 extern int register_cp_abi (struct cp_abi_ops *abi);
 199 extern void set_cp_abi_as_auto_default (const char *short_name);
 200
 201 #endif
 202