xref: /dragonfly/contrib/gdb-7/gdb/cp-abi.h (revision ef5ccd6c)
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) 2001-2013 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 modify
11    it under the terms of the GNU General Public License as published by
12    the Free Software Foundation; either version 3 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, see <http://www.gnu.org/licenses/>.  */
22 
23 #ifndef CP_ABI_H_
24 #define CP_ABI_H_ 1
25 
26 struct fn_field;
27 struct type;
28 struct value;
29 struct ui_file;
30 struct frame_info;
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
72      object.  */
73   base_object_dtor
74 };
75 
76 /* Return non-zero iff NAME is the mangled name of a destructor.
77    Actually, return an `enum dtor_kind' value describing what *kind*
78    of destructor it is.  */
79 extern enum dtor_kinds is_destructor_name (const char *name);
80 
81 
82 /* Return non-zero iff NAME is the mangled name of a vtable.  */
83 extern int is_vtable_name (const char *name);
84 
85 
86 /* Return non-zero iff NAME is the un-mangled name of an operator,
87    perhaps scoped within some class.  */
88 extern int is_operator_name (const char *name);
89 
90 
91 /* Return an object's virtual function as a value.
92 
93    VALUEP is a pointer to a pointer to a value, holding the object
94    whose virtual function we want to invoke.  If the ABI requires a
95    virtual function's caller to adjust the `this' pointer by an amount
96    retrieved from the vtable before invoking the function (i.e., we're
97    not using "vtable thunks" to do the adjustment automatically), then
98    this function may set *VALUEP to point to a new object with an
99    appropriately tweaked address.
100 
101    The J'th element of the overload set F is the virtual function of
102    *VALUEP we want to invoke.
103 
104    TYPE is the base type of *VALUEP whose method we're invoking ---
105    this is the type containing F.  OFFSET is the offset of that base
106    type within *VALUEP.  */
107 extern struct value *value_virtual_fn_field (struct value **valuep,
108 					     struct fn_field *f,
109 					     int j,
110 					     struct type *type,
111 					     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,
139 				     int *using_enc);
140 
141 /* Compute the offset of the baseclass which is the INDEXth baseclass
142    of class TYPE, for value at VALADDR (in host) at ADDRESS (in
143    target), offset by EMBEDDED_OFFSET.  VALADDR points to the raw
144    contents of VAL.  The result is the offset of the baseclass value
145    relative to (the address of)(ARG) + OFFSET.  */
146 
147 extern int baseclass_offset (struct type *type,
148 			     int index, const gdb_byte *valaddr,
149 			     int embedded_offset,
150 			     CORE_ADDR address,
151 			     const struct value *val);
152 
153 /* Describe the target of a pointer to method.  CONTENTS is the byte
154    pattern representing the pointer to method.  TYPE is the pointer to
155    method type.  STREAM is the stream to print it to.  */
156 void cplus_print_method_ptr (const gdb_byte *contents,
157 			     struct type *type,
158 			     struct ui_file *stream);
159 
160 /* Return the size of a pointer to member function of type
161    TO_TYPE.  */
162 int cplus_method_ptr_size (struct type *to_type);
163 
164 /* Return the method which should be called by applying METHOD_PTR to
165    *THIS_P, and adjust *THIS_P if necessary.  */
166 struct value *cplus_method_ptr_to_value (struct value **this_p,
167 					 struct value *method_ptr);
168 
169 /* Create the byte pattern in CONTENTS representing a pointer of type
170    TYPE to member function at ADDRESS (if IS_VIRTUAL is 0) or with
171    virtual table offset ADDRESS (if IS_VIRTUAL is 1).  This is the
172    opposite of cplus_method_ptr_to_value.  */
173 void cplus_make_method_ptr (struct type *type, gdb_byte *CONTENTS,
174 			    CORE_ADDR address, int is_virtual);
175 
176 /* Print the vtable for VALUE, if there is one.  If there is no
177    vtable, print a message, but do not throw.  */
178 
179 void cplus_print_vtable (struct value *value);
180 
181 /* Determine if we are currently in a C++ thunk.  If so, get the
182    address of the routine we are thunking to and continue to there
183    instead.  */
184 
185 CORE_ADDR cplus_skip_trampoline (struct frame_info *frame,
186 				 CORE_ADDR stop_pc);
187 
188 /* Return non-zero if an argument of type TYPE should be passed by
189    reference instead of value.  */
190 extern int cp_pass_by_reference (struct type *type);
191 
192 struct cp_abi_ops
193 {
194   const char *shortname;
195   const char *longname;
196   const char *doc;
197 
198   /* ABI-specific implementations for the functions declared
199      above.  */
200   enum ctor_kinds (*is_constructor_name) (const char *name);
201   enum dtor_kinds (*is_destructor_name) (const char *name);
202   int (*is_vtable_name) (const char *name);
203   int (*is_operator_name) (const char *name);
204   struct value *(*virtual_fn_field) (struct value **arg1p,
205 				     struct fn_field * f,
206 				     int j, struct type * type,
207 				     int offset);
208   struct type *(*rtti_type) (struct value *v, int *full,
209 			     int *top, int *using_enc);
210   int (*baseclass_offset) (struct type *type, int index,
211 			   const bfd_byte *valaddr, int embedded_offset,
212 			   CORE_ADDR address, const struct value *val);
213   void (*print_method_ptr) (const gdb_byte *contents,
214 			    struct type *type,
215 			    struct ui_file *stream);
216   int (*method_ptr_size) (struct type *);
217   void (*make_method_ptr) (struct type *, gdb_byte *,
218 			   CORE_ADDR, int);
219   struct value * (*method_ptr_to_value) (struct value **,
220 					 struct value *);
221   void (*print_vtable) (struct value *);
222   CORE_ADDR (*skip_trampoline) (struct frame_info *, CORE_ADDR);
223   int (*pass_by_reference) (struct type *type);
224 };
225 
226 
227 extern int register_cp_abi (struct cp_abi_ops *abi);
228 extern void set_cp_abi_as_auto_default (const char *short_name);
229 
230 #endif
231 
232