xref: /openbsd/gnu/usr.bin/binutils/gdb/hpacc-abi.c (revision 7b36286a)
1 /* Abstraction of HP aCC ABI.
2    Contributed by Daniel Berlin <dberlin@redhat.com>
3    Most of the real code is from HP, i've just fiddled it to fit in
4    the C++ ABI abstraction framework.
5 
6    Copyright 2001 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., 59 Temple Place - Suite 330,
25    Boston, MA 02111-1307, USA.  */
26 
27 #include "defs.h"
28 #include "value.h"
29 #include "gdb_regex.h"
30 #include "gdb_string.h"
31 #include "gdbtypes.h"
32 #include "gdbcore.h"
33 #include "cp-abi.h"
34 
35 struct cp_abi_ops hpacc_abi_ops;
36 
37 /* It appears the is_*_name stuff is never used when we try the hpACC
38  * ABI. As such, I have no clue what the real answers are. Shouldn't
39  * have any more effect than it does now.  */
40 static regex_t constructor_pattern;
41 static regex_t destructor_pattern;
42 static regex_t operator_pattern;
43 
44 static enum dtor_kinds
45 hpacc_is_destructor_name (const char *name)
46 {
47   if (regexec (&destructor_pattern, name, 0, 0, 0) == 0)
48     return complete_object_dtor;
49   else
50     return 0;
51 }
52 
53 static enum ctor_kinds
54 hpacc_is_constructor_name (const char *name)
55 {
56   if (regexec (&constructor_pattern, name, 0, 0, 0) == 0)
57     return complete_object_ctor;
58   else
59     return 0;
60 }
61 
62 static int
63 hpacc_is_operator_name (const char *name)
64 {
65   return regexec (&operator_pattern, name, 0, 0, 0) == 0;
66 }
67 
68 static int
69 hpacc_is_vtable_name (const char *name)
70 {
71   return strcmp (name,
72 		 "This will never match anything, please fill it in") == 0;
73 }
74 
75 /* Return a virtual function as a value.
76    ARG1 is the object which provides the virtual function
77    table pointer.  *ARG1P is side-effected in calling this function.
78    F is the list of member functions which contains the desired virtual
79    function.
80    J is an index into F which provides the desired virtual function.
81 
82    TYPE is the type in which F is located.  */
83 static struct value *
84 hpacc_virtual_fn_field (struct value **arg1p, struct fn_field * f, int j,
85 			struct type * type, int offset)
86 {
87   struct value *arg1 = *arg1p;
88   struct type *type1 = check_typedef (VALUE_TYPE (arg1));
89 
90   /* Deal with HP/Taligent runtime model for virtual functions */
91   struct value *vp;
92   struct value *argp;		/* arg1 cast to base */
93   CORE_ADDR coreptr;		/* pointer to target address */
94   int class_index;		/* which class segment pointer to use */
95   struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);	/* method type */
96 
97   argp = value_cast (type, *arg1p);
98 
99   if (VALUE_ADDRESS (argp) == 0)
100     error ("Address of object is null; object may not have been created.");
101 
102   /* pai: FIXME -- 32x64 possible problem? */
103   /* First word (4 bytes) in object layout is the vtable pointer */
104   coreptr = *(CORE_ADDR *) (VALUE_CONTENTS (argp));	/* pai: (temp)  */
105   /* + offset + VALUE_EMBEDDED_OFFSET (argp)); */
106 
107   if (!coreptr)
108     error
109       ("Virtual table pointer is null for object; object may not have been created.");
110 
111   /* pai/1997-05-09
112    * FIXME: The code here currently handles only
113    * the non-RRBC case of the Taligent/HP runtime spec; when RRBC
114    * is introduced, the condition for the "if" below will have to
115    * be changed to be a test for the RRBC case.  */
116 
117   if (1)
118     {
119       /* Non-RRBC case; the virtual function pointers are stored at fixed
120        * offsets in the virtual table. */
121 
122       /* Retrieve the offset in the virtual table from the debug
123        * info.  The offset of the vfunc's entry is in words from
124        * the beginning of the vtable; but first we have to adjust
125        * by HP_ACC_VFUNC_START to account for other entries */
126 
127       /* pai: FIXME: 32x64 problem here, a word may be 8 bytes in
128        * which case the multiplier should be 8 and values should be long */
129       vp = value_at (builtin_type_int,
130 		     coreptr + 4 * (TYPE_FN_FIELD_VOFFSET (f, j) +
131 				    HP_ACC_VFUNC_START), NULL);
132 
133       coreptr = *(CORE_ADDR *) (VALUE_CONTENTS (vp));
134       /* coreptr now contains the address of the virtual function */
135       /* (Actually, it contains the pointer to the plabel for the function. */
136     }
137   else
138     {
139       /* RRBC case; the virtual function pointers are found by double
140        * indirection through the class segment tables. */
141 
142       /* Choose class segment depending on type we were passed */
143       class_index = class_index_in_primary_list (type);
144 
145       /* Find class segment pointer.  These are in the vtable slots after
146        * some other entries, so adjust by HP_ACC_VFUNC_START for that. */
147       /* pai: FIXME 32x64 problem here, if words are 8 bytes long
148        * the multiplier below has to be 8 and value should be long. */
149       vp = value_at (builtin_type_int,
150 		     coreptr + 4 * (HP_ACC_VFUNC_START + class_index), NULL);
151       /* Indirect once more, offset by function index */
152       /* pai: FIXME 32x64 problem here, again multiplier could be 8 and value long */
153       coreptr =
154 	*(CORE_ADDR *) (VALUE_CONTENTS (vp) +
155 			4 * TYPE_FN_FIELD_VOFFSET (f, j));
156       vp = value_at (builtin_type_int, coreptr, NULL);
157       coreptr = *(CORE_ADDR *) (VALUE_CONTENTS (vp));
158 
159       /* coreptr now contains the address of the virtual function */
160       /* (Actually, it contains the pointer to the plabel for the function.) */
161 
162     }
163 
164   if (!coreptr)
165     error ("Address of virtual function is null; error in virtual table?");
166 
167   /* Wrap this addr in a value and return pointer */
168   vp = allocate_value (ftype);
169   VALUE_TYPE (vp) = ftype;
170   VALUE_ADDRESS (vp) = coreptr;
171 
172   /* pai: (temp) do we need the value_ind stuff in value_fn_field? */
173   return vp;
174 }
175 
176 
177 static struct type *
178 hpacc_value_rtti_type (struct value *v, int *full, int *top, int *using_enc)
179 {
180   struct type *known_type;
181   struct type *rtti_type;
182   CORE_ADDR coreptr;
183   struct value *vp;
184   int using_enclosing = 0;
185   long top_offset = 0;
186   char rtti_type_name[256];
187 
188   if (full)
189     *full = 0;
190   if (top)
191     *top = -1;
192   if (using_enc)
193     *using_enc = 0;
194 
195   /* Get declared type */
196   known_type = VALUE_TYPE (v);
197   CHECK_TYPEDEF (known_type);
198   /* RTTI works only or class objects */
199   if (TYPE_CODE (known_type) != TYPE_CODE_CLASS)
200     return NULL;
201 
202   /* If neither the declared type nor the enclosing type of the
203    * value structure has a HP ANSI C++ style virtual table,
204    * we can't do anything. */
205   if (!TYPE_HAS_VTABLE (known_type))
206     {
207       known_type = VALUE_ENCLOSING_TYPE (v);
208       CHECK_TYPEDEF (known_type);
209       if ((TYPE_CODE (known_type) != TYPE_CODE_CLASS) ||
210           !TYPE_HAS_VTABLE (known_type))
211         return NULL;		/* No RTTI, or not HP-compiled types */
212       CHECK_TYPEDEF (known_type);
213       using_enclosing = 1;
214     }
215 
216   if (using_enclosing && using_enc)
217     *using_enc = 1;
218 
219   /* First get the virtual table address */
220   coreptr = *(CORE_ADDR *) ((VALUE_CONTENTS_ALL (v))
221                             + VALUE_OFFSET (v)
222                             + (using_enclosing
223                                ? 0
224                                : VALUE_EMBEDDED_OFFSET (v)));
225   if (coreptr == 0)
226     /* return silently -- maybe called on gdb-generated value */
227     return NULL;
228 
229   /* Fetch the top offset of the object */
230   /* FIXME possible 32x64 problem with pointer size & arithmetic */
231   vp = value_at (builtin_type_int,
232                  coreptr + 4 * HP_ACC_TOP_OFFSET_OFFSET,
233                  VALUE_BFD_SECTION (v));
234   top_offset = value_as_long (vp);
235   if (top)
236     *top = top_offset;
237 
238   /* Fetch the typeinfo pointer */
239   /* FIXME possible 32x64 problem with pointer size & arithmetic */
240   vp = value_at (builtin_type_int, coreptr + 4 * HP_ACC_TYPEINFO_OFFSET,
241                  VALUE_BFD_SECTION (v));
242   /* Indirect through the typeinfo pointer and retrieve the pointer
243    * to the string name */
244   coreptr = *(CORE_ADDR *) (VALUE_CONTENTS (vp));
245   if (!coreptr)
246     error ("Retrieved null typeinfo pointer in trying to determine "
247            "run-time type");
248   /* 4 -> offset of name field */
249   vp = value_at (builtin_type_int, coreptr + 4, VALUE_BFD_SECTION (v));
250   /* FIXME possible 32x64 problem */
251 
252   coreptr = *(CORE_ADDR *) (VALUE_CONTENTS (vp));
253 
254   read_memory_string (coreptr, rtti_type_name, 256);
255 
256   if (strlen (rtti_type_name) == 0)
257     error ("Retrieved null type name from typeinfo");
258 
259   /* search for type */
260   rtti_type = lookup_typename (rtti_type_name, (struct block *) 0, 1);
261 
262   if (!rtti_type)
263     error ("Could not find run-time type: invalid type name %s in typeinfo??",
264            rtti_type_name);
265   CHECK_TYPEDEF (rtti_type);
266 #if 0
267   printf ("RTTI type name %s, tag %s, full? %d\n", TYPE_NAME (rtti_type),
268           TYPE_TAG_NAME (rtti_type), full ? *full : -1);
269 #endif
270   /* Check whether we have the entire object */
271   if (full			/* Non-null pointer passed */
272       &&
273       /* Either we checked on the whole object in hand and found the
274          top offset to be zero */
275       (((top_offset == 0) &&
276         using_enclosing &&
277         TYPE_LENGTH (known_type) == TYPE_LENGTH (rtti_type))
278        ||
279        /* Or we checked on the embedded object and top offset was the
280           same as the embedded offset */
281        ((top_offset == VALUE_EMBEDDED_OFFSET (v)) &&
282         !using_enclosing &&
283         TYPE_LENGTH (VALUE_ENCLOSING_TYPE (v)) == TYPE_LENGTH (rtti_type))))
284 
285     *full = 1;
286 
287   return rtti_type;
288 }
289 
290 extern int gnuv2_baseclass_offset (struct type *type, int index,
291 				   char *valaddr, CORE_ADDR address);
292 
293 static void
294 init_hpacc_ops (void)
295 {
296   hpacc_abi_ops.shortname = "hpaCC";
297   hpacc_abi_ops.longname = "HP aCC ABI";
298   hpacc_abi_ops.doc = "HP aCC ABI";
299   hpacc_abi_ops.is_destructor_name = hpacc_is_destructor_name;
300   hpacc_abi_ops.is_constructor_name = hpacc_is_constructor_name;
301   hpacc_abi_ops.is_vtable_name = hpacc_is_vtable_name;
302   hpacc_abi_ops.is_operator_name = hpacc_is_operator_name;
303   hpacc_abi_ops.virtual_fn_field = hpacc_virtual_fn_field;
304   hpacc_abi_ops.rtti_type = hpacc_value_rtti_type;
305   /* It seems that this function is specific to GNU G++ < 3.0.
306      However, it is called for data members even in the HP
307      case (although not for member functions).
308      FIXME: Is that correct?  */
309   hpacc_abi_ops.baseclass_offset = gnuv2_baseclass_offset;
310 }
311 
312 extern initialize_file_ftype _initialize_hpacc_abi; /* -Wmissing-prototypes */
313 
314 void
315 _initialize_hpacc_abi (void)
316 {
317   init_hpacc_ops ();
318 
319   regcomp (&constructor_pattern,
320 	   "^This will never match anything, please fill it in$", REG_NOSUB);
321 
322   regcomp (&destructor_pattern,
323 	   "^This will never match anything, please fill it in$", REG_NOSUB);
324 
325   regcomp (&operator_pattern,
326 	   "^This will never match anything, please fill it in$", REG_NOSUB);
327 
328   register_cp_abi (&hpacc_abi_ops);
329 }
330