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015a42b4 | 1 | /* Abstraction of GNU v2 abi. |
1bac305b | 2 | |
7b6bb8da | 3 | Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009, 2010, 2011 |
9b254dd1 | 4 | Free Software Foundation, Inc. |
1bac305b | 5 | |
015a42b4 | 6 | Contributed by Daniel Berlin <dberlin@redhat.com> |
015a42b4 JB |
7 | |
8 | This file is part of GDB. | |
9 | ||
a9762ec7 JB |
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 | |
015a42b4 JB |
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 | |
a9762ec7 | 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
015a42b4 JB |
22 | |
23 | #include "defs.h" | |
015a42b4 JB |
24 | #include "gdb_string.h" |
25 | #include "symtab.h" | |
26 | #include "gdbtypes.h" | |
27 | #include "value.h" | |
28 | #include "demangle.h" | |
29 | #include "cp-abi.h" | |
362ff856 | 30 | #include "cp-support.h" |
8af8e3bc | 31 | #include "exceptions.h" |
015a42b4 JB |
32 | |
33 | #include <ctype.h> | |
34 | ||
35 | struct cp_abi_ops gnu_v2_abi_ops; | |
36 | ||
37 | static int vb_match (struct type *, int, struct type *); | |
38 | ||
39 | static enum dtor_kinds | |
40 | gnuv2_is_destructor_name (const char *name) | |
41 | { | |
42 | if ((name[0] == '_' && is_cplus_marker (name[1]) && name[2] == '_') | |
43 | || strncmp (name, "__dt__", 6) == 0) | |
44 | return complete_object_dtor; | |
45 | else | |
46 | return 0; | |
47 | } | |
48 | ||
49 | static enum ctor_kinds | |
50 | gnuv2_is_constructor_name (const char *name) | |
51 | { | |
52 | if ((name[0] == '_' && name[1] == '_' | |
53 | && (isdigit (name[2]) || strchr ("Qt", name[2]))) | |
54 | || strncmp (name, "__ct__", 6) == 0) | |
55 | return complete_object_ctor; | |
56 | else | |
57 | return 0; | |
58 | } | |
59 | ||
60 | static int | |
61 | gnuv2_is_vtable_name (const char *name) | |
62 | { | |
63 | return (((name)[0] == '_' | |
64 | && (((name)[1] == 'V' && (name)[2] == 'T') | |
65 | || ((name)[1] == 'v' && (name)[2] == 't')) | |
66 | && is_cplus_marker ((name)[3])) || | |
67 | ((name)[0] == '_' && (name)[1] == '_' | |
68 | && (name)[2] == 'v' && (name)[3] == 't' && (name)[4] == '_')); | |
69 | } | |
70 | ||
71 | static int | |
72 | gnuv2_is_operator_name (const char *name) | |
73 | { | |
74 | return strncmp (name, "operator", 8) == 0; | |
75 | } | |
76 | ||
77 | \f | |
78 | /* Return a virtual function as a value. | |
79 | ARG1 is the object which provides the virtual function | |
80 | table pointer. *ARG1P is side-effected in calling this function. | |
81 | F is the list of member functions which contains the desired virtual | |
82 | function. | |
83 | J is an index into F which provides the desired virtual function. | |
84 | ||
85 | TYPE is the type in which F is located. */ | |
e933e538 AC |
86 | static struct value * |
87 | gnuv2_virtual_fn_field (struct value **arg1p, struct fn_field * f, int j, | |
015a42b4 JB |
88 | struct type * type, int offset) |
89 | { | |
e933e538 | 90 | struct value *arg1 = *arg1p; |
df407dfe | 91 | struct type *type1 = check_typedef (value_type (arg1)); |
015a42b4 JB |
92 | struct type *entry_type; |
93 | /* First, get the virtual function table pointer. That comes | |
94 | with a strange type, so cast it to type `pointer to long' (which | |
95 | should serve just fine as a function type). Then, index into | |
96 | the table, and convert final value to appropriate function type. */ | |
e933e538 AC |
97 | struct value *entry; |
98 | struct value *vfn; | |
99 | struct value *vtbl; | |
2497b498 | 100 | LONGEST vi = (LONGEST) TYPE_FN_FIELD_VOFFSET (f, j); |
015a42b4 JB |
101 | struct type *fcontext = TYPE_FN_FIELD_FCONTEXT (f, j); |
102 | struct type *context; | |
81fe8080 DE |
103 | struct type *context_vptr_basetype; |
104 | int context_vptr_fieldno; | |
105 | ||
015a42b4 JB |
106 | if (fcontext == NULL) |
107 | /* We don't have an fcontext (e.g. the program was compiled with | |
108 | g++ version 1). Try to get the vtbl from the TYPE_VPTR_BASETYPE. | |
109 | This won't work right for multiple inheritance, but at least we | |
110 | should do as well as GDB 3.x did. */ | |
111 | fcontext = TYPE_VPTR_BASETYPE (type); | |
112 | context = lookup_pointer_type (fcontext); | |
113 | /* Now context is a pointer to the basetype containing the vtbl. */ | |
114 | if (TYPE_TARGET_TYPE (context) != type1) | |
115 | { | |
e933e538 | 116 | struct value *tmp = value_cast (context, value_addr (arg1)); |
d8734c88 | 117 | |
015a42b4 | 118 | arg1 = value_ind (tmp); |
df407dfe | 119 | type1 = check_typedef (value_type (arg1)); |
015a42b4 JB |
120 | } |
121 | ||
122 | context = type1; | |
123 | /* Now context is the basetype containing the vtbl. */ | |
124 | ||
125 | /* This type may have been defined before its virtual function table | |
126 | was. If so, fill in the virtual function table entry for the | |
127 | type now. */ | |
81fe8080 DE |
128 | context_vptr_fieldno = get_vptr_fieldno (context, &context_vptr_basetype); |
129 | /* FIXME: What to do if vptr_fieldno is still -1? */ | |
015a42b4 JB |
130 | |
131 | /* The virtual function table is now an array of structures | |
132 | which have the form { int16 offset, delta; void *pfn; }. */ | |
81fe8080 DE |
133 | vtbl = value_primitive_field (arg1, 0, context_vptr_fieldno, |
134 | context_vptr_basetype); | |
015a42b4 JB |
135 | |
136 | /* With older versions of g++, the vtbl field pointed to an array | |
0963b4bd | 137 | of structures. Nowadays it points directly to the structure. */ |
df407dfe AC |
138 | if (TYPE_CODE (value_type (vtbl)) == TYPE_CODE_PTR |
139 | && TYPE_CODE (TYPE_TARGET_TYPE (value_type (vtbl))) == TYPE_CODE_ARRAY) | |
015a42b4 JB |
140 | { |
141 | /* Handle the case where the vtbl field points to an | |
0963b4bd | 142 | array of structures. */ |
015a42b4 JB |
143 | vtbl = value_ind (vtbl); |
144 | ||
145 | /* Index into the virtual function table. This is hard-coded because | |
146 | looking up a field is not cheap, and it may be important to save | |
147 | time, e.g. if the user has set a conditional breakpoint calling | |
148 | a virtual function. */ | |
149 | entry = value_subscript (vtbl, vi); | |
150 | } | |
151 | else | |
152 | { | |
0963b4bd MS |
153 | /* Handle the case where the vtbl field points directly to a |
154 | structure. */ | |
89eef114 | 155 | vtbl = value_ptradd (vtbl, vi); |
015a42b4 JB |
156 | entry = value_ind (vtbl); |
157 | } | |
158 | ||
df407dfe | 159 | entry_type = check_typedef (value_type (entry)); |
015a42b4 JB |
160 | |
161 | if (TYPE_CODE (entry_type) == TYPE_CODE_STRUCT) | |
162 | { | |
0963b4bd MS |
163 | /* Move the `this' pointer according to the virtual function table. */ |
164 | set_value_offset (arg1, value_offset (arg1) | |
165 | + 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. */ |
0963b4bd MS |
180 | deprecated_set_value_type (vfn, |
181 | lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j))); | |
015a42b4 JB |
182 | |
183 | *arg1p = arg1; | |
184 | return vfn; | |
185 | } | |
186 | ||
187 | ||
b9362cc7 | 188 | static struct type * |
e933e538 | 189 | gnuv2_value_rtti_type (struct value *v, int *full, int *top, int *using_enc) |
015a42b4 JB |
190 | { |
191 | struct type *known_type; | |
192 | struct type *rtti_type; | |
015a42b4 JB |
193 | CORE_ADDR vtbl; |
194 | struct minimal_symbol *minsym; | |
7d63ec12 | 195 | char *demangled_name, *p; |
015a42b4 | 196 | struct type *btype; |
81fe8080 DE |
197 | struct type *known_type_vptr_basetype; |
198 | int known_type_vptr_fieldno; | |
015a42b4 JB |
199 | |
200 | if (full) | |
201 | *full = 0; | |
202 | if (top) | |
203 | *top = -1; | |
204 | if (using_enc) | |
205 | *using_enc = 0; | |
206 | ||
0963b4bd | 207 | /* Get declared type. */ |
df407dfe | 208 | known_type = value_type (v); |
015a42b4 | 209 | CHECK_TYPEDEF (known_type); |
0963b4bd | 210 | /* RTTI works only or class objects. */ |
015a42b4 JB |
211 | if (TYPE_CODE (known_type) != TYPE_CODE_CLASS) |
212 | return NULL; | |
213 | ||
214 | /* Plan on this changing in the future as i get around to setting | |
215 | the vtables properly for G++ compiled stuff. Also, I'll be using | |
216 | the type info functions, which are always right. Deal with it | |
217 | until then. */ | |
218 | ||
81fe8080 DE |
219 | /* Try to get the vptr basetype, fieldno. */ |
220 | known_type_vptr_fieldno = get_vptr_fieldno (known_type, | |
221 | &known_type_vptr_basetype); | |
015a42b4 | 222 | |
81fe8080 DE |
223 | /* If we can't find it, give up. */ |
224 | if (known_type_vptr_fieldno < 0) | |
015a42b4 JB |
225 | return NULL; |
226 | ||
227 | /* Make sure our basetype and known type match, otherwise, cast | |
0963b4bd | 228 | so we can get at the vtable properly. */ |
81fe8080 | 229 | btype = known_type_vptr_basetype; |
015a42b4 JB |
230 | CHECK_TYPEDEF (btype); |
231 | if (btype != known_type ) | |
232 | { | |
233 | v = value_cast (btype, v); | |
234 | if (using_enc) | |
235 | *using_enc=1; | |
236 | } | |
0963b4bd MS |
237 | /* We can't use value_ind here, because it would want to use RTTI, and |
238 | we'd waste a bunch of time figuring out we already know the type. | |
239 | Besides, we don't care about the type, just the actual pointer. */ | |
42ae5230 | 240 | if (value_address (value_field (v, known_type_vptr_fieldno)) == 0) |
015a42b4 JB |
241 | return NULL; |
242 | ||
81fe8080 | 243 | vtbl = value_as_address (value_field (v, known_type_vptr_fieldno)); |
015a42b4 | 244 | |
0963b4bd | 245 | /* Try to find a symbol that is the vtable. */ |
015a42b4 JB |
246 | minsym=lookup_minimal_symbol_by_pc(vtbl); |
247 | if (minsym==NULL | |
3567439c | 248 | || (demangled_name=SYMBOL_LINKAGE_NAME (minsym))==NULL |
015a42b4 JB |
249 | || !is_vtable_name (demangled_name)) |
250 | return NULL; | |
251 | ||
0963b4bd | 252 | /* If we just skip the prefix, we get screwed by namespaces. */ |
015a42b4 | 253 | demangled_name=cplus_demangle(demangled_name,DMGL_PARAMS|DMGL_ANSI); |
7d63ec12 MS |
254 | p = strchr (demangled_name, ' '); |
255 | if (p) | |
256 | *p = '\0'; | |
015a42b4 | 257 | |
0963b4bd MS |
258 | /* Lookup the type for the name. */ |
259 | /* FIXME: chastain/2003-11-26: block=NULL is bogus. See pr gdb/1465. */ | |
362ff856 MC |
260 | rtti_type = cp_lookup_rtti_type (demangled_name, NULL); |
261 | if (rtti_type == NULL) | |
015a42b4 JB |
262 | return NULL; |
263 | ||
264 | if (TYPE_N_BASECLASSES(rtti_type) > 1 && full && (*full) != 1) | |
265 | { | |
266 | if (top) | |
0963b4bd MS |
267 | *top = TYPE_BASECLASS_BITPOS (rtti_type, |
268 | TYPE_VPTR_FIELDNO(rtti_type)) / 8; | |
015a42b4 JB |
269 | if (top && ((*top) >0)) |
270 | { | |
271 | if (TYPE_LENGTH(rtti_type) > TYPE_LENGTH(known_type)) | |
272 | { | |
273 | if (full) | |
274 | *full=0; | |
275 | } | |
276 | else | |
277 | { | |
278 | if (full) | |
279 | *full=1; | |
280 | } | |
281 | } | |
282 | } | |
283 | else | |
284 | { | |
285 | if (full) | |
286 | *full=1; | |
287 | } | |
015a42b4 JB |
288 | |
289 | return rtti_type; | |
290 | } | |
291 | ||
1514d34e DJ |
292 | /* Return true if the INDEXth field of TYPE is a virtual baseclass |
293 | pointer which is for the base class whose type is BASECLASS. */ | |
294 | ||
295 | static int | |
296 | vb_match (struct type *type, int index, struct type *basetype) | |
297 | { | |
298 | struct type *fieldtype; | |
299 | char *name = TYPE_FIELD_NAME (type, index); | |
300 | char *field_class_name = NULL; | |
301 | ||
302 | if (*name != '_') | |
303 | return 0; | |
304 | /* gcc 2.4 uses _vb$. */ | |
305 | if (name[1] == 'v' && name[2] == 'b' && is_cplus_marker (name[3])) | |
306 | field_class_name = name + 4; | |
307 | /* gcc 2.5 will use __vb_. */ | |
308 | if (name[1] == '_' && name[2] == 'v' && name[3] == 'b' && name[4] == '_') | |
309 | field_class_name = name + 5; | |
310 | ||
311 | if (field_class_name == NULL) | |
312 | /* This field is not a virtual base class pointer. */ | |
313 | return 0; | |
314 | ||
315 | /* It's a virtual baseclass pointer, now we just need to find out whether | |
316 | it is for this baseclass. */ | |
317 | fieldtype = TYPE_FIELD_TYPE (type, index); | |
318 | if (fieldtype == NULL | |
319 | || TYPE_CODE (fieldtype) != TYPE_CODE_PTR) | |
320 | /* "Can't happen". */ | |
321 | return 0; | |
322 | ||
323 | /* What we check for is that either the types are equal (needed for | |
324 | nameless types) or have the same name. This is ugly, and a more | |
325 | elegant solution should be devised (which would probably just push | |
326 | the ugliness into symbol reading unless we change the stabs format). */ | |
327 | if (TYPE_TARGET_TYPE (fieldtype) == basetype) | |
328 | return 1; | |
329 | ||
330 | if (TYPE_NAME (basetype) != NULL | |
331 | && TYPE_NAME (TYPE_TARGET_TYPE (fieldtype)) != NULL | |
bde58177 AC |
332 | && strcmp (TYPE_NAME (basetype), |
333 | TYPE_NAME (TYPE_TARGET_TYPE (fieldtype))) == 0) | |
1514d34e DJ |
334 | return 1; |
335 | return 0; | |
336 | } | |
337 | ||
8af8e3bc PA |
338 | /* Compute the offset of the baseclass which is the INDEXth baseclass |
339 | of class TYPE, for value at VALADDR (in host) at ADDRESS (in | |
340 | target). The result is the offset of the baseclass value relative | |
341 | to (the address of)(ARG) + OFFSET. */ | |
1514d34e | 342 | |
f23f4c59 | 343 | static int |
06c4d4dc | 344 | gnuv2_baseclass_offset (struct type *type, int index, |
8af8e3bc PA |
345 | const bfd_byte *valaddr, int embedded_offset, |
346 | CORE_ADDR address, const struct value *val) | |
1514d34e DJ |
347 | { |
348 | struct type *basetype = TYPE_BASECLASS (type, index); | |
349 | ||
350 | if (BASETYPE_VIA_VIRTUAL (type, index)) | |
351 | { | |
352 | /* Must hunt for the pointer to this virtual baseclass. */ | |
aa1ee363 AC |
353 | int i, len = TYPE_NFIELDS (type); |
354 | int n_baseclasses = TYPE_N_BASECLASSES (type); | |
1514d34e DJ |
355 | |
356 | /* First look for the virtual baseclass pointer | |
357 | in the fields. */ | |
358 | for (i = n_baseclasses; i < len; i++) | |
359 | { | |
360 | if (vb_match (type, i, basetype)) | |
361 | { | |
8af8e3bc PA |
362 | struct type *field_type; |
363 | int field_offset; | |
364 | int field_length; | |
365 | CORE_ADDR addr; | |
366 | ||
367 | field_type = check_typedef (TYPE_FIELD_TYPE (type, i)); | |
368 | field_offset = TYPE_FIELD_BITPOS (type, i) / 8; | |
369 | field_length = TYPE_LENGTH (field_type); | |
370 | ||
371 | if (!value_bytes_available (val, embedded_offset + field_offset, | |
372 | field_length)) | |
373 | throw_error (NOT_AVAILABLE_ERROR, | |
374 | _("Virtual baseclass pointer is not available")); | |
1514d34e | 375 | |
8af8e3bc PA |
376 | addr = unpack_pointer (field_type, |
377 | valaddr + embedded_offset + field_offset); | |
378 | ||
379 | return addr - (LONGEST) address + embedded_offset; | |
1514d34e DJ |
380 | } |
381 | } | |
382 | /* Not in the fields, so try looking through the baseclasses. */ | |
383 | for (i = index + 1; i < n_baseclasses; i++) | |
384 | { | |
8af8e3bc PA |
385 | /* Don't go through baseclass_offset, as that wraps |
386 | exceptions, thus, inner exceptions would be wrapped more | |
387 | than once. */ | |
1514d34e | 388 | int boffset = |
8af8e3bc PA |
389 | gnuv2_baseclass_offset (type, i, valaddr, |
390 | embedded_offset, address, val); | |
d8734c88 | 391 | |
1514d34e DJ |
392 | if (boffset) |
393 | return boffset; | |
394 | } | |
8af8e3bc PA |
395 | |
396 | error (_("Baseclass offset not found")); | |
1514d34e DJ |
397 | } |
398 | ||
399 | /* Baseclass is easily computed. */ | |
400 | return TYPE_BASECLASS_BITPOS (type, index) / 8; | |
401 | } | |
015a42b4 JB |
402 | |
403 | static void | |
404 | init_gnuv2_ops (void) | |
405 | { | |
406 | gnu_v2_abi_ops.shortname = "gnu-v2"; | |
407 | gnu_v2_abi_ops.longname = "GNU G++ Version 2 ABI"; | |
408 | gnu_v2_abi_ops.doc = "G++ Version 2 ABI"; | |
409 | gnu_v2_abi_ops.is_destructor_name = gnuv2_is_destructor_name; | |
410 | gnu_v2_abi_ops.is_constructor_name = gnuv2_is_constructor_name; | |
411 | gnu_v2_abi_ops.is_vtable_name = gnuv2_is_vtable_name; | |
412 | gnu_v2_abi_ops.is_operator_name = gnuv2_is_operator_name; | |
413 | gnu_v2_abi_ops.virtual_fn_field = gnuv2_virtual_fn_field; | |
414 | gnu_v2_abi_ops.rtti_type = gnuv2_value_rtti_type; | |
1514d34e | 415 | gnu_v2_abi_ops.baseclass_offset = gnuv2_baseclass_offset; |
015a42b4 JB |
416 | } |
417 | ||
b9362cc7 AC |
418 | extern initialize_file_ftype _initialize_gnu_v2_abi; /* -Wmissing-prototypes */ |
419 | ||
015a42b4 JB |
420 | void |
421 | _initialize_gnu_v2_abi (void) | |
422 | { | |
423 | init_gnuv2_ops (); | |
fe1f4a5e DJ |
424 | register_cp_abi (&gnu_v2_abi_ops); |
425 | set_cp_abi_as_auto_default (gnu_v2_abi_ops.shortname); | |
015a42b4 | 426 | } |