1 /* Abstraction of GNU v2 abi.
2 Contributed by Daniel Berlin <dberlin@redhat.com>
3 Copyright 2001 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or
9 it under the terms of the GNU General Public License as published
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 #include "gdb_string.h"
34 struct cp_abi_ops gnu_v2_abi_ops
;
36 static int vb_match (struct type
*, int, struct type
*);
38 static enum dtor_kinds
39 gnuv2_is_destructor_name (const char *name
)
41 if ((name
[0] == '_' && is_cplus_marker (name
[1]) && name
[2] == '_')
42 || strncmp (name
, "__dt__", 6) == 0)
43 return complete_object_dtor
;
48 static enum ctor_kinds
49 gnuv2_is_constructor_name (const char *name
)
51 if ((name
[0] == '_' && name
[1] == '_'
52 && (isdigit (name
[2]) || strchr ("Qt", name
[2])))
53 || strncmp (name
, "__ct__", 6) == 0)
54 return complete_object_ctor
;
60 gnuv2_is_vtable_name (const char *name
)
62 return (((name
)[0] == '_'
63 && (((name
)[1] == 'V' && (name
)[2] == 'T')
64 || ((name
)[1] == 'v' && (name
)[2] == 't'))
65 && is_cplus_marker ((name
)[3])) ||
66 ((name
)[0] == '_' && (name
)[1] == '_'
67 && (name
)[2] == 'v' && (name
)[3] == 't' && (name
)[4] == '_'));
71 gnuv2_is_operator_name (const char *name
)
73 return strncmp (name
, "operator", 8) == 0;
77 /* Return a virtual function as a value.
78 ARG1 is the object which provides the virtual function
79 table pointer. *ARG1P is side-effected in calling this function.
80 F is the list of member functions which contains the desired virtual
82 J is an index into F which provides the desired virtual function.
84 TYPE is the type in which F is located. */
86 gnuv2_virtual_fn_field (value_ptr
* arg1p
, struct fn_field
* f
, int j
,
87 struct type
* type
, int offset
)
89 value_ptr arg1
= *arg1p
;
90 struct type
*type1
= check_typedef (VALUE_TYPE (arg1
));
93 struct type
*entry_type
;
94 /* First, get the virtual function table pointer. That comes
95 with a strange type, so cast it to type `pointer to long' (which
96 should serve just fine as a function type). Then, index into
97 the table, and convert final value to appropriate function type. */
98 value_ptr entry
, vfn
, vtbl
;
99 value_ptr vi
= value_from_longest (builtin_type_int
,
100 (LONGEST
) TYPE_FN_FIELD_VOFFSET (f
, j
));
101 struct type
*fcontext
= TYPE_FN_FIELD_FCONTEXT (f
, j
);
102 struct type
*context
;
103 if (fcontext
== NULL
)
104 /* We don't have an fcontext (e.g. the program was compiled with
105 g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE.
106 This won't work right for multiple inheritance, but at least we
107 should do as well as GDB 3.x did. */
108 fcontext
= TYPE_VPTR_BASETYPE (type
);
109 context
= lookup_pointer_type (fcontext
);
110 /* Now context is a pointer to the basetype containing the vtbl. */
111 if (TYPE_TARGET_TYPE (context
) != type1
)
113 value_ptr tmp
= value_cast (context
, value_addr (arg1
));
114 arg1
= value_ind (tmp
);
115 type1
= check_typedef (VALUE_TYPE (arg1
));
119 /* Now context is the basetype containing the vtbl. */
121 /* This type may have been defined before its virtual function table
122 was. If so, fill in the virtual function table entry for the
124 if (TYPE_VPTR_FIELDNO (context
) < 0)
125 fill_in_vptr_fieldno (context
);
127 /* The virtual function table is now an array of structures
128 which have the form { int16 offset, delta; void *pfn; }. */
129 vtbl
= value_primitive_field (arg1
, 0, TYPE_VPTR_FIELDNO (context
),
130 TYPE_VPTR_BASETYPE (context
));
132 /* With older versions of g++, the vtbl field pointed to an array
133 of structures. Nowadays it points directly to the structure. */
134 if (TYPE_CODE (VALUE_TYPE (vtbl
)) == TYPE_CODE_PTR
135 && TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (vtbl
))) == TYPE_CODE_ARRAY
)
137 /* Handle the case where the vtbl field points to an
138 array of structures. */
139 vtbl
= value_ind (vtbl
);
141 /* Index into the virtual function table. This is hard-coded because
142 looking up a field is not cheap, and it may be important to save
143 time, e.g. if the user has set a conditional breakpoint calling
144 a virtual function. */
145 entry
= value_subscript (vtbl
, vi
);
149 /* Handle the case where the vtbl field points directly to a structure. */
150 vtbl
= value_add (vtbl
, vi
);
151 entry
= value_ind (vtbl
);
154 entry_type
= check_typedef (VALUE_TYPE (entry
));
156 if (TYPE_CODE (entry_type
) == TYPE_CODE_STRUCT
)
158 /* Move the `this' pointer according to the virtual function table. */
159 VALUE_OFFSET (arg1
) += value_as_long (value_field (entry
, 0));
161 if (!VALUE_LAZY (arg1
))
163 VALUE_LAZY (arg1
) = 1;
164 value_fetch_lazy (arg1
);
167 vfn
= value_field (entry
, 2);
169 else if (TYPE_CODE (entry_type
) == TYPE_CODE_PTR
)
172 error ("I'm confused: virtual function table has bad type");
173 /* Reinstantiate the function pointer with the correct type. */
174 VALUE_TYPE (vfn
) = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f
, j
));
182 gnuv2_value_rtti_type (value_ptr v
, int *full
, int *top
, int *using_enc
)
184 struct type
*known_type
;
185 struct type
*rtti_type
;
188 int using_enclosing
= 0;
190 char rtti_type_name
[256];
192 struct minimal_symbol
*minsym
;
194 char *demangled_name
;
204 /* Get declared type */
205 known_type
= VALUE_TYPE (v
);
206 CHECK_TYPEDEF (known_type
);
207 /* RTTI works only or class objects */
208 if (TYPE_CODE (known_type
) != TYPE_CODE_CLASS
)
211 /* Plan on this changing in the future as i get around to setting
212 the vtables properly for G++ compiled stuff. Also, I'll be using
213 the type info functions, which are always right. Deal with it
216 /* If the type has no vptr fieldno, try to get it filled in */
217 if (TYPE_VPTR_FIELDNO(known_type
) < 0)
218 fill_in_vptr_fieldno(known_type
);
220 /* If we still can't find one, give up */
221 if (TYPE_VPTR_FIELDNO(known_type
) < 0)
224 /* Make sure our basetype and known type match, otherwise, cast
225 so we can get at the vtable properly.
227 btype
= TYPE_VPTR_BASETYPE (known_type
);
228 CHECK_TYPEDEF (btype
);
229 if (btype
!= known_type
)
231 v
= value_cast (btype
, v
);
236 We can't use value_ind here, because it would want to use RTTI, and
237 we'd waste a bunch of time figuring out we already know the type.
238 Besides, we don't care about the type, just the actual pointer
240 if (VALUE_ADDRESS (value_field (v
, TYPE_VPTR_FIELDNO (known_type
))) == 0)
244 If we are enclosed by something that isn't us, adjust the
245 address properly and set using_enclosing.
247 if (VALUE_ENCLOSING_TYPE(v
) != VALUE_TYPE(v
))
250 int bitpos
= TYPE_BASECLASS_BITPOS (known_type
,
251 TYPE_VPTR_FIELDNO (known_type
));
252 tempval
=value_field (v
, TYPE_VPTR_FIELDNO(known_type
));
253 VALUE_ADDRESS(tempval
) += bitpos
/ 8;
254 vtbl
=value_as_pointer (tempval
);
259 vtbl
=value_as_pointer(value_field(v
,TYPE_VPTR_FIELDNO(known_type
)));
263 /* Try to find a symbol that is the vtable */
264 minsym
=lookup_minimal_symbol_by_pc(vtbl
);
266 || (demangled_name
=SYMBOL_NAME(minsym
))==NULL
267 || !is_vtable_name (demangled_name
))
270 /* If we just skip the prefix, we get screwed by namespaces */
271 demangled_name
=cplus_demangle(demangled_name
,DMGL_PARAMS
|DMGL_ANSI
);
272 *(strchr(demangled_name
,' '))=0;
274 /* Lookup the type for the name */
275 rtti_type
=lookup_typename(demangled_name
, (struct block
*)0,1);
280 if (TYPE_N_BASECLASSES(rtti_type
) > 1 && full
&& (*full
) != 1)
283 *top
=TYPE_BASECLASS_BITPOS(rtti_type
,TYPE_VPTR_FIELDNO(rtti_type
))/8;
284 if (top
&& ((*top
) >0))
286 if (TYPE_LENGTH(rtti_type
) > TYPE_LENGTH(known_type
))
304 *using_enc
=using_enclosing
;
311 init_gnuv2_ops (void)
313 gnu_v2_abi_ops
.shortname
= "gnu-v2";
314 gnu_v2_abi_ops
.longname
= "GNU G++ Version 2 ABI";
315 gnu_v2_abi_ops
.doc
= "G++ Version 2 ABI";
316 gnu_v2_abi_ops
.is_destructor_name
= gnuv2_is_destructor_name
;
317 gnu_v2_abi_ops
.is_constructor_name
= gnuv2_is_constructor_name
;
318 gnu_v2_abi_ops
.is_vtable_name
= gnuv2_is_vtable_name
;
319 gnu_v2_abi_ops
.is_operator_name
= gnuv2_is_operator_name
;
320 gnu_v2_abi_ops
.virtual_fn_field
= gnuv2_virtual_fn_field
;
321 gnu_v2_abi_ops
.rtti_type
= gnuv2_value_rtti_type
;
325 _initialize_gnu_v2_abi (void)
328 register_cp_abi (gnu_v2_abi_ops
);
329 switch_to_cp_abi ("gnu-v2");