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015a42b4 | 1 | /* Abstraction of GNU v2 abi. |
1bac305b | 2 | |
6aba47ca | 3 | Copyright (C) 2001, 2002, 2003, 2005, 2007 Free Software Foundation, Inc. |
1bac305b | 4 | |
015a42b4 | 5 | Contributed by Daniel Berlin <dberlin@redhat.com> |
015a42b4 JB |
6 | |
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or | |
10 | modify | |
11 | it under the terms of the GNU General Public License as published | |
12 | by | |
13 | the Free Software Foundation; either version 2 of the License, or | |
14 | (at your option) any later version. | |
15 | ||
16 | This program is distributed in the hope that it will be useful, | |
17 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | GNU General Public License for more details. | |
20 | ||
21 | You should have received a copy of the GNU General Public License | |
22 | along with this program; if not, write to the Free Software | |
197e01b6 EZ |
23 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
24 | Boston, MA 02110-1301, USA. */ | |
015a42b4 JB |
25 | |
26 | #include "defs.h" | |
015a42b4 JB |
27 | #include "gdb_string.h" |
28 | #include "symtab.h" | |
29 | #include "gdbtypes.h" | |
30 | #include "value.h" | |
31 | #include "demangle.h" | |
32 | #include "cp-abi.h" | |
362ff856 | 33 | #include "cp-support.h" |
6b08edad | 34 | #include "gnu-v2-abi.h" |
015a42b4 JB |
35 | |
36 | #include <ctype.h> | |
37 | ||
38 | struct cp_abi_ops gnu_v2_abi_ops; | |
39 | ||
40 | static int vb_match (struct type *, int, struct type *); | |
41 | ||
42 | static enum dtor_kinds | |
43 | gnuv2_is_destructor_name (const char *name) | |
44 | { | |
45 | if ((name[0] == '_' && is_cplus_marker (name[1]) && name[2] == '_') | |
46 | || strncmp (name, "__dt__", 6) == 0) | |
47 | return complete_object_dtor; | |
48 | else | |
49 | return 0; | |
50 | } | |
51 | ||
52 | static enum ctor_kinds | |
53 | gnuv2_is_constructor_name (const char *name) | |
54 | { | |
55 | if ((name[0] == '_' && name[1] == '_' | |
56 | && (isdigit (name[2]) || strchr ("Qt", name[2]))) | |
57 | || strncmp (name, "__ct__", 6) == 0) | |
58 | return complete_object_ctor; | |
59 | else | |
60 | return 0; | |
61 | } | |
62 | ||
63 | static int | |
64 | gnuv2_is_vtable_name (const char *name) | |
65 | { | |
66 | return (((name)[0] == '_' | |
67 | && (((name)[1] == 'V' && (name)[2] == 'T') | |
68 | || ((name)[1] == 'v' && (name)[2] == 't')) | |
69 | && is_cplus_marker ((name)[3])) || | |
70 | ((name)[0] == '_' && (name)[1] == '_' | |
71 | && (name)[2] == 'v' && (name)[3] == 't' && (name)[4] == '_')); | |
72 | } | |
73 | ||
74 | static int | |
75 | gnuv2_is_operator_name (const char *name) | |
76 | { | |
77 | return strncmp (name, "operator", 8) == 0; | |
78 | } | |
79 | ||
80 | \f | |
81 | /* Return a virtual function as a value. | |
82 | ARG1 is the object which provides the virtual function | |
83 | table pointer. *ARG1P is side-effected in calling this function. | |
84 | F is the list of member functions which contains the desired virtual | |
85 | function. | |
86 | J is an index into F which provides the desired virtual function. | |
87 | ||
88 | TYPE is the type in which F is located. */ | |
e933e538 AC |
89 | static struct value * |
90 | gnuv2_virtual_fn_field (struct value **arg1p, struct fn_field * f, int j, | |
015a42b4 JB |
91 | struct type * type, int offset) |
92 | { | |
e933e538 | 93 | struct value *arg1 = *arg1p; |
df407dfe | 94 | struct type *type1 = check_typedef (value_type (arg1)); |
015a42b4 JB |
95 | |
96 | ||
97 | struct type *entry_type; | |
98 | /* First, get the virtual function table pointer. That comes | |
99 | with a strange type, so cast it to type `pointer to long' (which | |
100 | should serve just fine as a function type). Then, index into | |
101 | the table, and convert final value to appropriate function type. */ | |
e933e538 AC |
102 | struct value *entry; |
103 | struct value *vfn; | |
104 | struct value *vtbl; | |
105 | struct value *vi = value_from_longest (builtin_type_int, | |
015a42b4 JB |
106 | (LONGEST) TYPE_FN_FIELD_VOFFSET (f, j)); |
107 | struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j); | |
108 | struct type *context; | |
109 | if (fcontext == NULL) | |
110 | /* We don't have an fcontext (e.g. the program was compiled with | |
111 | g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE. | |
112 | This won't work right for multiple inheritance, but at least we | |
113 | should do as well as GDB 3.x did. */ | |
114 | fcontext = TYPE_VPTR_BASETYPE (type); | |
115 | context = lookup_pointer_type (fcontext); | |
116 | /* Now context is a pointer to the basetype containing the vtbl. */ | |
117 | if (TYPE_TARGET_TYPE (context) != type1) | |
118 | { | |
e933e538 | 119 | struct value *tmp = value_cast (context, value_addr (arg1)); |
015a42b4 | 120 | arg1 = value_ind (tmp); |
df407dfe | 121 | type1 = check_typedef (value_type (arg1)); |
015a42b4 JB |
122 | } |
123 | ||
124 | context = type1; | |
125 | /* Now context is the basetype containing the vtbl. */ | |
126 | ||
127 | /* This type may have been defined before its virtual function table | |
128 | was. If so, fill in the virtual function table entry for the | |
129 | type now. */ | |
130 | if (TYPE_VPTR_FIELDNO (context) < 0) | |
131 | fill_in_vptr_fieldno (context); | |
132 | ||
133 | /* The virtual function table is now an array of structures | |
134 | which have the form { int16 offset, delta; void *pfn; }. */ | |
135 | vtbl = value_primitive_field (arg1, 0, TYPE_VPTR_FIELDNO (context), | |
136 | TYPE_VPTR_BASETYPE (context)); | |
137 | ||
138 | /* With older versions of g++, the vtbl field pointed to an array | |
139 | of structures. Nowadays it points directly to the structure. */ | |
df407dfe AC |
140 | if (TYPE_CODE (value_type (vtbl)) == TYPE_CODE_PTR |
141 | && TYPE_CODE (TYPE_TARGET_TYPE (value_type (vtbl))) == TYPE_CODE_ARRAY) | |
015a42b4 JB |
142 | { |
143 | /* Handle the case where the vtbl field points to an | |
144 | array of structures. */ | |
145 | vtbl = value_ind (vtbl); | |
146 | ||
147 | /* Index into the virtual function table. This is hard-coded because | |
148 | looking up a field is not cheap, and it may be important to save | |
149 | time, e.g. if the user has set a conditional breakpoint calling | |
150 | a virtual function. */ | |
151 | entry = value_subscript (vtbl, vi); | |
152 | } | |
153 | else | |
154 | { | |
155 | /* Handle the case where the vtbl field points directly to a structure. */ | |
156 | vtbl = value_add (vtbl, vi); | |
157 | entry = value_ind (vtbl); | |
158 | } | |
159 | ||
df407dfe | 160 | entry_type = check_typedef (value_type (entry)); |
015a42b4 JB |
161 | |
162 | if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT) | |
163 | { | |
164 | /* Move the `this' pointer according to the virtual function table. */ | |
f5cf64a7 | 165 | set_value_offset (arg1, value_offset (arg1) + value_as_long (value_field (entry, 0))); |
015a42b4 | 166 | |
d69fe07e | 167 | if (!value_lazy (arg1)) |
015a42b4 | 168 | { |
dfa52d88 | 169 | set_value_lazy (arg1, 1); |
015a42b4 JB |
170 | value_fetch_lazy (arg1); |
171 | } | |
172 | ||
173 | vfn = value_field (entry, 2); | |
174 | } | |
175 | else if (TYPE_CODE (entry_type) == TYPE_CODE_PTR) | |
176 | vfn = entry; | |
177 | else | |
8a3fe4f8 | 178 | error (_("I'm confused: virtual function table has bad type")); |
015a42b4 | 179 | /* Reinstantiate the function pointer with the correct type. */ |
04624583 | 180 | deprecated_set_value_type (vfn, lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j))); |
015a42b4 JB |
181 | |
182 | *arg1p = arg1; | |
183 | return vfn; | |
184 | } | |
185 | ||
186 | ||
b9362cc7 | 187 | static struct type * |
e933e538 | 188 | gnuv2_value_rtti_type (struct value *v, int *full, int *top, int *using_enc) |
015a42b4 JB |
189 | { |
190 | struct type *known_type; | |
191 | struct type *rtti_type; | |
192 | CORE_ADDR coreptr; | |
e933e538 | 193 | struct value *vp; |
015a42b4 JB |
194 | long top_offset = 0; |
195 | char rtti_type_name[256]; | |
196 | CORE_ADDR vtbl; | |
197 | struct minimal_symbol *minsym; | |
198 | struct symbol *sym; | |
199 | char *demangled_name; | |
200 | struct type *btype; | |
201 | ||
202 | if (full) | |
203 | *full = 0; | |
204 | if (top) | |
205 | *top = -1; | |
206 | if (using_enc) | |
207 | *using_enc = 0; | |
208 | ||
209 | /* Get declared type */ | |
df407dfe | 210 | known_type = value_type (v); |
015a42b4 JB |
211 | CHECK_TYPEDEF (known_type); |
212 | /* RTTI works only or class objects */ | |
213 | if (TYPE_CODE (known_type) != TYPE_CODE_CLASS) | |
214 | return NULL; | |
215 | ||
216 | /* Plan on this changing in the future as i get around to setting | |
217 | the vtables properly for G++ compiled stuff. Also, I'll be using | |
218 | the type info functions, which are always right. Deal with it | |
219 | until then. */ | |
220 | ||
221 | /* If the type has no vptr fieldno, try to get it filled in */ | |
222 | if (TYPE_VPTR_FIELDNO(known_type) < 0) | |
223 | fill_in_vptr_fieldno(known_type); | |
224 | ||
225 | /* If we still can't find one, give up */ | |
226 | if (TYPE_VPTR_FIELDNO(known_type) < 0) | |
227 | return NULL; | |
228 | ||
229 | /* Make sure our basetype and known type match, otherwise, cast | |
230 | so we can get at the vtable properly. | |
231 | */ | |
232 | btype = TYPE_VPTR_BASETYPE (known_type); | |
233 | CHECK_TYPEDEF (btype); | |
234 | if (btype != known_type ) | |
235 | { | |
236 | v = value_cast (btype, v); | |
237 | if (using_enc) | |
238 | *using_enc=1; | |
239 | } | |
240 | /* | |
241 | We can't use value_ind here, because it would want to use RTTI, and | |
242 | we'd waste a bunch of time figuring out we already know the type. | |
243 | Besides, we don't care about the type, just the actual pointer | |
244 | */ | |
245 | if (VALUE_ADDRESS (value_field (v, TYPE_VPTR_FIELDNO (known_type))) == 0) | |
246 | return NULL; | |
247 | ||
2a73a662 | 248 | vtbl=value_as_address(value_field(v,TYPE_VPTR_FIELDNO(known_type))); |
015a42b4 JB |
249 | |
250 | /* Try to find a symbol that is the vtable */ | |
251 | minsym=lookup_minimal_symbol_by_pc(vtbl); | |
252 | if (minsym==NULL | |
22abf04a | 253 | || (demangled_name=DEPRECATED_SYMBOL_NAME (minsym))==NULL |
015a42b4 JB |
254 | || !is_vtable_name (demangled_name)) |
255 | return NULL; | |
256 | ||
257 | /* If we just skip the prefix, we get screwed by namespaces */ | |
258 | demangled_name=cplus_demangle(demangled_name,DMGL_PARAMS|DMGL_ANSI); | |
259 | *(strchr(demangled_name,' '))=0; | |
260 | ||
261 | /* Lookup the type for the name */ | |
362ff856 MC |
262 | /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */ |
263 | rtti_type = cp_lookup_rtti_type (demangled_name, NULL); | |
264 | if (rtti_type == NULL) | |
015a42b4 JB |
265 | return NULL; |
266 | ||
267 | if (TYPE_N_BASECLASSES(rtti_type) > 1 && full && (*full) != 1) | |
268 | { | |
269 | if (top) | |
270 | *top=TYPE_BASECLASS_BITPOS(rtti_type,TYPE_VPTR_FIELDNO(rtti_type))/8; | |
271 | if (top && ((*top) >0)) | |
272 | { | |
273 | if (TYPE_LENGTH(rtti_type) > TYPE_LENGTH(known_type)) | |
274 | { | |
275 | if (full) | |
276 | *full=0; | |
277 | } | |
278 | else | |
279 | { | |
280 | if (full) | |
281 | *full=1; | |
282 | } | |
283 | } | |
284 | } | |
285 | else | |
286 | { | |
287 | if (full) | |
288 | *full=1; | |
289 | } | |
015a42b4 JB |
290 | |
291 | return rtti_type; | |
292 | } | |
293 | ||
1514d34e DJ |
294 | /* Return true if the INDEXth field of TYPE is a virtual baseclass |
295 | pointer which is for the base class whose type is BASECLASS. */ | |
296 | ||
297 | static int | |
298 | vb_match (struct type *type, int index, struct type *basetype) | |
299 | { | |
300 | struct type *fieldtype; | |
301 | char *name = TYPE_FIELD_NAME (type, index); | |
302 | char *field_class_name = NULL; | |
303 | ||
304 | if (*name != '_') | |
305 | return 0; | |
306 | /* gcc 2.4 uses _vb$. */ | |
307 | if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3])) | |
308 | field_class_name = name + 4; | |
309 | /* gcc 2.5 will use __vb_. */ | |
310 | if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_') | |
311 | field_class_name = name + 5; | |
312 | ||
313 | if (field_class_name == NULL) | |
314 | /* This field is not a virtual base class pointer. */ | |
315 | return 0; | |
316 | ||
317 | /* It's a virtual baseclass pointer, now we just need to find out whether | |
318 | it is for this baseclass. */ | |
319 | fieldtype = TYPE_FIELD_TYPE (type, index); | |
320 | if (fieldtype == NULL | |
321 | || TYPE_CODE (fieldtype) != TYPE_CODE_PTR) | |
322 | /* "Can't happen". */ | |
323 | return 0; | |
324 | ||
325 | /* What we check for is that either the types are equal (needed for | |
326 | nameless types) or have the same name. This is ugly, and a more | |
327 | elegant solution should be devised (which would probably just push | |
328 | the ugliness into symbol reading unless we change the stabs format). */ | |
329 | if (TYPE_TARGET_TYPE (fieldtype) == basetype) | |
330 | return 1; | |
331 | ||
332 | if (TYPE_NAME (basetype) != NULL | |
333 | && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL | |
bde58177 AC |
334 | && strcmp (TYPE_NAME (basetype), |
335 | TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))) == 0) | |
1514d34e DJ |
336 | return 1; |
337 | return 0; | |
338 | } | |
339 | ||
340 | /* Compute the offset of the baseclass which is | |
341 | the INDEXth baseclass of class TYPE, | |
342 | for value at VALADDR (in host) at ADDRESS (in target). | |
343 | The result is the offset of the baseclass value relative | |
344 | to (the address of)(ARG) + OFFSET. | |
345 | ||
346 | -1 is returned on error. */ | |
347 | ||
348 | int | |
06c4d4dc AC |
349 | gnuv2_baseclass_offset (struct type *type, int index, |
350 | const bfd_byte *valaddr, CORE_ADDR address) | |
1514d34e DJ |
351 | { |
352 | struct type *basetype = TYPE_BASECLASS (type, index); | |
353 | ||
354 | if (BASETYPE_VIA_VIRTUAL (type, index)) | |
355 | { | |
356 | /* Must hunt for the pointer to this virtual baseclass. */ | |
aa1ee363 AC |
357 | int i, len = TYPE_NFIELDS (type); |
358 | int n_baseclasses = TYPE_N_BASECLASSES (type); | |
1514d34e DJ |
359 | |
360 | /* First look for the virtual baseclass pointer | |
361 | in the fields. */ | |
362 | for (i = n_baseclasses; i < len; i++) | |
363 | { | |
364 | if (vb_match (type, i, basetype)) | |
365 | { | |
366 | CORE_ADDR addr | |
367 | = unpack_pointer (TYPE_FIELD_TYPE (type, i), | |
368 | valaddr + (TYPE_FIELD_BITPOS (type, i) / 8)); | |
369 | ||
370 | return addr - (LONGEST) address; | |
371 | } | |
372 | } | |
373 | /* Not in the fields, so try looking through the baseclasses. */ | |
374 | for (i = index + 1; i < n_baseclasses; i++) | |
375 | { | |
376 | int boffset = | |
377 | baseclass_offset (type, i, valaddr, address); | |
378 | if (boffset) | |
379 | return boffset; | |
380 | } | |
381 | /* Not found. */ | |
382 | return -1; | |
383 | } | |
384 | ||
385 | /* Baseclass is easily computed. */ | |
386 | return TYPE_BASECLASS_BITPOS (type, index) / 8; | |
387 | } | |
015a42b4 JB |
388 | |
389 | static void | |
390 | init_gnuv2_ops (void) | |
391 | { | |
392 | gnu_v2_abi_ops.shortname = "gnu-v2"; | |
393 | gnu_v2_abi_ops.longname = "GNU G++ Version 2 ABI"; | |
394 | gnu_v2_abi_ops.doc = "G++ Version 2 ABI"; | |
395 | gnu_v2_abi_ops.is_destructor_name = gnuv2_is_destructor_name; | |
396 | gnu_v2_abi_ops.is_constructor_name = gnuv2_is_constructor_name; | |
397 | gnu_v2_abi_ops.is_vtable_name = gnuv2_is_vtable_name; | |
398 | gnu_v2_abi_ops.is_operator_name = gnuv2_is_operator_name; | |
399 | gnu_v2_abi_ops.virtual_fn_field = gnuv2_virtual_fn_field; | |
400 | gnu_v2_abi_ops.rtti_type = gnuv2_value_rtti_type; | |
1514d34e | 401 | gnu_v2_abi_ops.baseclass_offset = gnuv2_baseclass_offset; |
015a42b4 JB |
402 | } |
403 | ||
b9362cc7 AC |
404 | extern initialize_file_ftype _initialize_gnu_v2_abi; /* -Wmissing-prototypes */ |
405 | ||
015a42b4 JB |
406 | void |
407 | _initialize_gnu_v2_abi (void) | |
408 | { | |
409 | init_gnuv2_ops (); | |
fe1f4a5e DJ |
410 | register_cp_abi (&gnu_v2_abi_ops); |
411 | set_cp_abi_as_auto_default (gnu_v2_abi_ops.shortname); | |
015a42b4 | 412 | } |