1/* Copyright (C) 2012-2017 Free Software Foundation, Inc.
2
3 This file is part of GCC.
4
5 GCC is free software; you can redistribute it and/or modify it
6 under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3, or (at your option)
8 any later version.
9
10 GCC is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with GCC; see the file COPYING3. If not see
17<http://www.gnu.org/licenses/>. */
18
19/* Virtual Table Pointer Security Pass - Detect corruption of vtable pointers
20 before using them for virtual method dispatches. */
21
22/* This file is part of the vtable security feature implementation.
23 The vtable security feature is designed to detect when a virtual
24 call is about to be made through an invalid vtable pointer
25 (possibly due to data corruption or malicious attacks). The
26 compiler finds every virtual call, and inserts a verification call
27 before the virtual call. The verification call takes the actual
28 vtable pointer value in the object through which the virtual call
29 is being made, and compares the vtable pointer against a set of all
30 valid vtable pointers that the object could contain (this set is
31 based on the declared type of the object). If the pointer is in
32 the valid set, execution is allowed to continue; otherwise the
33 program is halted.
34
35 There are several pieces needed in order to make this work: 1. For
36 every virtual class in the program (i.e. a class that contains
37 virtual methods), we need to build the set of all possible valid
38 vtables that an object of that class could point to. This includes
39 vtables for any class(es) that inherit from the class under
40 consideration. 2. For every such data set we build up, we need a
41 way to find and reference the data set. This is complicated by the
42 fact that the real vtable addresses are not known until runtime,
43 when the program is loaded into memory, but we need to reference the
44 sets at compile time when we are inserting verification calls into
45 the program. 3. We need to find every virtual call in the program,
46 and insert the verification call (with the appropriate arguments)
47 before the virtual call. 4. We need some runtime library pieces:
48 the code to build up the data sets at runtime; the code to actually
49 perform the verification using the data sets; and some code to set
50 protections on the data sets, so they themselves do not become
51 hacker targets.
52
53 To find and reference the set of valid vtable pointers for any given
54 virtual class, we create a special global varible for each virtual
55 class. We refer to this as the "vtable map variable" for that
56 class. The vtable map variable has the type "void *", and is
57 initialized by the compiler to NULL. At runtime when the set of
58 valid vtable pointers for a virtual class, e.g. class Foo, is built,
59 the vtable map variable for class Foo is made to point to the set.
60 During compile time, when the compiler is inserting verification
61 calls into the program, it passes the vtable map variable for the
62 appropriate class to the verification call, so that at runtime the
63 verification call can find the appropriate data set.
64
65 The actual set of valid vtable pointers for a virtual class,
66 e.g. class Foo, cannot be built until runtime, when the vtables get
67 loaded into memory and their addresses are known. But the knowledge
68 about which vtables belong in which class' hierarchy is only known
69 at compile time. Therefore at compile time we collect class
70 hierarchy and vtable information about every virtual class, and we
71 generate calls to build up the data sets at runtime. To build the
72 data sets, we call one of the functions we add to the runtime
73 library, __VLTRegisterPair. __VLTRegisterPair takes two arguments,
74 a vtable map variable and the address of a vtable. If the vtable
75 map variable is currently NULL, it creates a new data set (hash
76 table), makes the vtable map variable point to the new data set, and
77 inserts the vtable address into the data set. If the vtable map
78 variable is not NULL, it just inserts the vtable address into the
79 data set. In order to make sure that our data sets are built before
80 any verification calls happen, we create a special constructor
81 initialization function for each compilation unit, give it a very
82 high initialization priority, and insert all of our calls to
83 __VLTRegisterPair into our special constructor initialization
84 function.
85
86 The vtable verification feature is controlled by the flag
87 '-fvtable-verify='. There are three flavors of this:
88 '-fvtable-verify=std', '-fvtable-verify=preinit', and
89 '-fvtable-verify=none'. If the option '-fvtable-verfy=preinit' is
90 used, then our constructor initialization function gets put into the
91 preinit array. This is necessary if there are data sets that need
92 to be built very early in execution. If the constructor
93 initialization function gets put into the preinit array, the we also
94 add calls to __VLTChangePermission at the beginning and end of the
95 function. The call at the beginning sets the permissions on the
96 data sets and vtable map variables to read/write, and the one at the
97 end makes them read-only. If the '-fvtable-verify=std' option is
98 used, the constructor initialization functions are executed at their
99 normal time, and the __VLTChangePermission calls are handled
100 differently (see the comments in libstdc++-v3/libsupc++/vtv_rts.cc).
101 The option '-fvtable-verify=none' turns off vtable verification.
102
103 This file contains code to find and record the class hierarchies for
104 the virtual classes in a program, and all the vtables associated
105 with each such class; to generate the vtable map variables; and to
106 generate the constructor initialization function (with the calls to
107 __VLTRegisterPair, and __VLTChangePermission). The main data
108 structures used for collecting the class hierarchy data and
109 building/maintaining the vtable map variable data are defined in
110 gcc/vtable-verify.h, because they are used both here and in
111 gcc/vtable-verify.c. */
112
113#include "config.h"
114#include "system.h"
115#include "coretypes.h"
116#include "vtable-verify.h"
117#include "cp-tree.h"
118#include "stringpool.h"
119#include "cgraph.h"
120#include "output.h"
121#include "tree-iterator.h"
122#include "gimplify.h"
123#include "stor-layout.h"
124
125static int num_calls_to_regset = 0;
126static int num_calls_to_regpair = 0;
127static int current_set_size;
128
129/* Mark these specially since they need to be stored in precompiled
130 header IR. */
131static GTY (()) vec<tree, va_gc> *vlt_saved_class_info;
132static GTY (()) tree vlt_register_pairs_fndecl = NULL_TREE;
133static GTY (()) tree vlt_register_set_fndecl = NULL_TREE;
134
135struct work_node {
136 struct vtv_graph_node *node;
137 struct work_node *next;
138};
139
140struct vtbl_map_node *vtable_find_or_create_map_decl (tree);
141
142/* As part of vtable verification the compiler generates and inserts
143 calls to __VLTVerifyVtablePointer, which is in libstdc++. This
144 function builds and initializes the function decl that is used
145 in generating those function calls.
146
147 In addition to __VLTVerifyVtablePointer there is also
148 __VLTVerifyVtablePointerDebug which can be used in place of
149 __VLTVerifyVtablePointer, and which takes extra parameters and
150 outputs extra information, to help debug problems. The debug
151 version of this function is generated and used if flag_vtv_debug is
152 true.
153
154 The signatures for these functions are:
155
156 void * __VLTVerifyVtablePointer (void **, void*);
157 void * __VLTVerifyVtablePointerDebug (void**, void *, char *, char *);
158*/
159
160void
161vtv_build_vtable_verify_fndecl (void)
162{
163 tree func_type = NULL_TREE;
164
165 if (verify_vtbl_ptr_fndecl != NULL_TREE
166 && TREE_CODE (verify_vtbl_ptr_fndecl) != ERROR_MARK)
167 return;
168
169 if (flag_vtv_debug)
170 {
171 func_type = build_function_type_list (const_ptr_type_node,
172 build_pointer_type (ptr_type_node),
173 const_ptr_type_node,
174 const_string_type_node,
175 const_string_type_node,
176 NULL_TREE);
177 verify_vtbl_ptr_fndecl =
178 build_lang_decl (FUNCTION_DECL,
179 get_identifier ("__VLTVerifyVtablePointerDebug"),
180 func_type);
181 }
182 else
183 {
184 func_type = build_function_type_list (const_ptr_type_node,
185 build_pointer_type (ptr_type_node),
186 const_ptr_type_node,
187 NULL_TREE);
188 verify_vtbl_ptr_fndecl =
189 build_lang_decl (FUNCTION_DECL,
190 get_identifier ("__VLTVerifyVtablePointer"),
191 func_type);
192 }
193
194 TREE_NOTHROW (verify_vtbl_ptr_fndecl) = 1;
195 DECL_ATTRIBUTES (verify_vtbl_ptr_fndecl)
196 = tree_cons (get_identifier ("leaf"), NULL,
197 DECL_ATTRIBUTES (verify_vtbl_ptr_fndecl));
198 DECL_PURE_P (verify_vtbl_ptr_fndecl) = 1;
199 TREE_PUBLIC (verify_vtbl_ptr_fndecl) = 1;
200 DECL_PRESERVE_P (verify_vtbl_ptr_fndecl) = 1;
201}
202
203/* As part of vtable verification the compiler generates and inserts
204 calls to __VLTRegisterSet and __VLTRegisterPair, which are in
205 libsupc++. This function builds and initializes the function decls
206 that are used in generating those function calls.
207
208 The signatures for these functions are:
209
210 void __VLTRegisterSetDebug (void **, const void *, std::size_t,
211 size_t, void **);
212
213 void __VLTRegisterSet (void **, const void *, std::size_t,
214 size_t, void **);
215
216 void __VLTRegisterPairDebug (void **, const void *, size_t,
217 const void *, const char *, const char *);
218
219 void __VLTRegisterPair (void **, const void *, size_t, const void *);
220*/
221
222static void
223init_functions (void)
224{
225 tree register_set_type;
226 tree register_pairs_type;
227
228 if (vlt_register_set_fndecl != NULL_TREE)
229 return;
230
231 gcc_assert (vlt_register_pairs_fndecl == NULL_TREE);
232 gcc_assert (vlt_register_set_fndecl == NULL_TREE);
233
234 /* Build function decl for __VLTRegisterSet*. */
235
236 register_set_type = build_function_type_list
237 (void_type_node,
238 build_pointer_type (ptr_type_node),
239 const_ptr_type_node,
240 size_type_node,
241 size_type_node,
242 build_pointer_type (ptr_type_node),
243 NULL_TREE);
244
245 if (flag_vtv_debug)
246 vlt_register_set_fndecl = build_lang_decl
247 (FUNCTION_DECL,
248 get_identifier ("__VLTRegisterSetDebug"),
249 register_set_type);
250 else
251 vlt_register_set_fndecl = build_lang_decl
252 (FUNCTION_DECL,
253 get_identifier ("__VLTRegisterSet"),
254 register_set_type);
255
256
257 TREE_NOTHROW (vlt_register_set_fndecl) = 1;
258 DECL_ATTRIBUTES (vlt_register_set_fndecl) =
259 tree_cons (get_identifier ("leaf"), NULL,
260 DECL_ATTRIBUTES (vlt_register_set_fndecl));
261 DECL_EXTERNAL(vlt_register_set_fndecl) = 1;
262 TREE_PUBLIC (vlt_register_set_fndecl) = 1;
263 DECL_PRESERVE_P (vlt_register_set_fndecl) = 1;
264 SET_DECL_LANGUAGE (vlt_register_set_fndecl, lang_cplusplus);
265
266 /* Build function decl for __VLTRegisterPair*. */
267
268 if (flag_vtv_debug)
269 {
270 register_pairs_type = build_function_type_list (void_type_node,
271 build_pointer_type
272 (ptr_type_node),
273 const_ptr_type_node,
274 size_type_node,
275 const_ptr_type_node,
276 const_string_type_node,
277 const_string_type_node,
278 NULL_TREE);
279
280 vlt_register_pairs_fndecl = build_lang_decl
281 (FUNCTION_DECL,
282 get_identifier ("__VLTRegisterPairDebug"),
283 register_pairs_type);
284 }
285 else
286 {
287 register_pairs_type = build_function_type_list (void_type_node,
288 build_pointer_type
289 (ptr_type_node),
290 const_ptr_type_node,
291 size_type_node,
292 const_ptr_type_node,
293 NULL_TREE);
294
295 vlt_register_pairs_fndecl = build_lang_decl
296 (FUNCTION_DECL,
297 get_identifier ("__VLTRegisterPair"),
298 register_pairs_type);
299 }
300
301 TREE_NOTHROW (vlt_register_pairs_fndecl) = 1;
302 DECL_ATTRIBUTES (vlt_register_pairs_fndecl) =
303 tree_cons (get_identifier ("leaf"), NULL,
304 DECL_ATTRIBUTES (vlt_register_pairs_fndecl));
305 DECL_EXTERNAL(vlt_register_pairs_fndecl) = 1;
306 TREE_PUBLIC (vlt_register_pairs_fndecl) = 1;
307 DECL_PRESERVE_P (vlt_register_pairs_fndecl) = 1;
308 SET_DECL_LANGUAGE (vlt_register_pairs_fndecl, lang_cplusplus);
309
310}
311
312/* This is a helper function for
313 vtv_compute_class_hierarchy_transitive_closure. It adds a
314 vtv_graph_node to the WORKLIST, which is a linked list of
315 seen-but-not-yet-processed nodes. INSERTED is a bitmap, one bit
316 per node, to help make sure that we don't insert a node into the
317 worklist more than once. Each node represents a class somewhere in
318 our class hierarchy information. Every node in the graph gets added
319 to the worklist exactly once and removed from the worklist exactly
320 once (when all of its children have been processed). */
321
322static void
323add_to_worklist (struct work_node **worklist, struct vtv_graph_node *node,
324 sbitmap inserted)
325{
326 struct work_node *new_work_node;
327
328 if (bitmap_bit_p (inserted, node->class_uid))
329 return;
330
331 new_work_node = XNEW (struct work_node);
332 new_work_node->next = *worklist;
333 new_work_node->node = node;
334 *worklist = new_work_node;
335
336 bitmap_set_bit (inserted, node->class_uid);
337}
338
339/* This is a helper function for
340 vtv_compute_class_hierarchy_transitive_closure. It goes through
341 the WORKLIST of class hierarchy nodes looking for a "leaf" node,
342 i.e. a node whose children in the hierarchy have all been
343 processed. When it finds the next leaf node, it removes it from
344 the linked list (WORKLIST) and returns the node. */
345
346static struct vtv_graph_node *
347find_and_remove_next_leaf_node (struct work_node **worklist)
348{
349 struct work_node *prev, *cur;
350 struct vtv_graph_node *ret_val = NULL;
351
352 for (prev = NULL, cur = *worklist; cur; prev = cur, cur = cur->next)
353 {
354 if ((cur->node->children).length() == cur->node->num_processed_children)
355 {
356 if (prev == NULL)
357 (*worklist) = cur->next;
358 else
359 prev->next = cur->next;
360
361 cur->next = NULL;
362 ret_val = cur->node;
363 free (cur);
364 return ret_val;
365 }
366 }
367
368 return NULL;
369}
370
371/* In our class hierarchy graph, each class node contains a bitmap,
372 with one bit for each class in the hierarchy. The bits are set for
373 classes that are descendants in the graph of the current node.
374 Initially the descendants bitmap is only set for immediate
375 descendants. This function traverses the class hierarchy graph,
376 bottom up, filling in the transitive closures for the descendants
377 as we rise up the graph. */
378
379void
380vtv_compute_class_hierarchy_transitive_closure (void)
381{
382 struct work_node *worklist = NULL;
383 sbitmap inserted = sbitmap_alloc (num_vtable_map_nodes);
384 unsigned i;
385 unsigned j;
386
387 /* Note: Every node in the graph gets added to the worklist exactly
388 once and removed from the worklist exactly once (when all of its
389 children have been processed). Each node's children edges are
390 followed exactly once, and each node's parent edges are followed
391 exactly once. So this algorithm is roughly O(V + 2E), i.e.
392 O(E + V). */
393
394 /* Set-up: */
395 /* Find all the "leaf" nodes in the graph, and add them to the worklist. */
396 bitmap_clear (inserted);
397 for (j = 0; j < num_vtable_map_nodes; ++j)
398 {
399 struct vtbl_map_node *cur = vtbl_map_nodes_vec[j];
400 if (cur->class_info
401 && ((cur->class_info->children).length() == 0)
402 && ! (bitmap_bit_p (inserted, cur->class_info->class_uid)))
403 add_to_worklist (&worklist, cur->class_info, inserted);
404 }
405
406 /* Main work: pull next leaf node off work list, process it, add its
407 parents to the worklist, where a 'leaf' node is one that has no
408 children, or all of its children have been processed. */
409 while (worklist)
410 {
411 struct vtv_graph_node *temp_node =
412 find_and_remove_next_leaf_node (&worklist);
413
414 gcc_assert (temp_node != NULL);
415 temp_node->descendants = sbitmap_alloc (num_vtable_map_nodes);
416 bitmap_clear (temp_node->descendants);
417 bitmap_set_bit (temp_node->descendants, temp_node->class_uid);
418 for (i = 0; i < (temp_node->children).length(); ++i)
419 bitmap_ior (temp_node->descendants, temp_node->descendants,
420 temp_node->children[i]->descendants);
421 for (i = 0; i < (temp_node->parents).length(); ++i)
422 {
423 temp_node->parents[i]->num_processed_children =
424 temp_node->parents[i]->num_processed_children + 1;
425 if (!bitmap_bit_p (inserted, temp_node->parents[i]->class_uid))
426 add_to_worklist (&worklist, temp_node->parents[i], inserted);
427 }
428 }
429}
430
431/* Keep track of which pairs we have already created __VLTRegisterPair
432 calls for, to prevent creating duplicate calls within the same
433 compilation unit. VTABLE_DECL is the var decl for the vtable of
434 the (descendant) class that we are adding to our class hierarchy
435 data. VPTR_ADDRESS is an expression for calculating the correct
436 offset into the vtable (VTABLE_DECL). It is the actual vtable
437 pointer address that will be stored in our list of valid vtable
438 pointers for BASE_CLASS. BASE_CLASS is the record_type node for
439 the base class to whose hiearchy we want to add
440 VPTR_ADDRESS. (VTABLE_DECL should be the vtable for BASE_CLASS or
441 one of BASE_CLASS' descendents. */
442
443static bool
444check_and_record_registered_pairs (tree vtable_decl, tree vptr_address,
445 tree base_class)
446{
447 unsigned offset;
448 struct vtbl_map_node *base_vtable_map_node;
449 bool inserted_something = false;
450
451
452 if (TREE_CODE (vptr_address) == ADDR_EXPR
453 && TREE_CODE (TREE_OPERAND (vptr_address, 0)) == MEM_REF)
454 vptr_address = TREE_OPERAND (vptr_address, 0);
455
456 if (TREE_OPERAND_LENGTH (vptr_address) > 1)
457 offset = TREE_INT_CST_LOW (TREE_OPERAND (vptr_address, 1));
458 else
459 offset = 0;
460
461 base_vtable_map_node = vtbl_map_get_node (TYPE_MAIN_VARIANT (base_class));
462
463 inserted_something = vtbl_map_node_registration_insert
464 (base_vtable_map_node,
465 vtable_decl,
466 offset);
467 return !inserted_something;
468}
469
470/* Given an IDENTIFIER_NODE, build and return a string literal based on it. */
471
472static tree
473build_string_from_id (tree identifier)
474{
475 int len;
476
477 gcc_assert (TREE_CODE (identifier) == IDENTIFIER_NODE);
478
479 len = IDENTIFIER_LENGTH (identifier);
480 return build_string_literal (len + 1, IDENTIFIER_POINTER (identifier));
481}
482
483/* A class may contain secondary vtables in it, for various reasons.
484 This function goes through the decl chain of a class record looking
485 for any fields that point to secondary vtables, and adding calls to
486 __VLTRegisterPair for the secondary vtable pointers.
487
488 BASE_CLASS_DECL_ARG is an expression for the address of the vtable
489 map variable for the BASE_CLASS (whose hierarchy we are currently
490 updating). BASE_CLASS is the record_type node for the base class.
491 RECORD_TYPE is the record_type node for the descendant class that
492 we are possibly adding to BASE_CLASS's hierarchy. BODY is the
493 function body for the constructor init function to which we are
494 adding our calls to __VLTRegisterPair. */
495
496static void
497register_construction_vtables (tree base_class, tree record_type,
498 vec<tree> *vtable_ptr_array)
499{
500 tree vtbl_var_decl;
501
502 if (TREE_CODE (record_type) != RECORD_TYPE)
503 return;
504
505 vtbl_var_decl = CLASSTYPE_VTABLES (record_type);
506
507 if (CLASSTYPE_VBASECLASSES (record_type))
508 {
509 tree vtt_decl;
510 bool already_registered = false;
511 tree val_vtbl_decl = NULL_TREE;
512
513 vtt_decl = DECL_CHAIN (vtbl_var_decl);
514
515 /* Check to see if we have found a VTT. Add its data if appropriate. */
516 if (vtt_decl)
517 {
518 tree values = DECL_INITIAL (vtt_decl);
519 if (TREE_ASM_WRITTEN (vtt_decl)
520 && values != NULL_TREE
521 && TREE_CODE (values) == CONSTRUCTOR
522 && TREE_CODE (TREE_TYPE (values)) == ARRAY_TYPE)
523 {
524 unsigned HOST_WIDE_INT cnt;
525 constructor_elt *ce;
526
527 /* Loop through the initialization values for this
528 vtable to get all the correct vtable pointer
529 addresses that we need to add to our set of valid
530 vtable pointers for the current base class. This may
531 result in adding more than just the element assigned
532 to the primary vptr of the class, so we may end up
533 with more vtable pointers than are strictly
534 necessary. */
535
536 for (cnt = 0;
537 vec_safe_iterate (CONSTRUCTOR_ELTS (values),
538 cnt, &ce);
539 cnt++)
540 {
541 tree value = ce->value;
542
543 /* Search for the ADDR_EXPR operand within the value. */
544
545 while (value
546 && TREE_OPERAND (value, 0)
547 && TREE_CODE (TREE_OPERAND (value, 0)) == ADDR_EXPR)
548 value = TREE_OPERAND (value, 0);
549
550 /* The VAR_DECL for the vtable should be the first
551 argument of the ADDR_EXPR, which is the first
552 argument of value.*/
553
554 if (TREE_OPERAND (value, 0))
555 val_vtbl_decl = TREE_OPERAND (value, 0);
556
557 while (!VAR_P (val_vtbl_decl)
558 && TREE_OPERAND (val_vtbl_decl, 0))
559 val_vtbl_decl = TREE_OPERAND (val_vtbl_decl, 0);
560
561 gcc_assert (VAR_P (val_vtbl_decl));
562
563 /* Check to see if we already have this vtable pointer in
564 our valid set for this base class. */
565
566 already_registered = check_and_record_registered_pairs
567 (val_vtbl_decl,
568 value,
569 base_class);
570
571 if (already_registered)
572 continue;
573
574 /* Add this vtable pointer to our set of valid
575 pointers for the base class. */
576
577 vtable_ptr_array->safe_push (value);
578 current_set_size++;
579 }
580 }
581 }
582 }
583}
584
585/* This function iterates through all the vtables it can find from the
586 BINFO of a class, to make sure we have found ALL of the vtables
587 that an object of that class could point to. Generate calls to
588 __VLTRegisterPair for those vtable pointers that we find.
589
590 BINFO is the tree_binfo node for the BASE_CLASS. BODY is the
591 function body for the constructor init function to which we are
592 adding calls to __VLTRegisterPair. ARG1 is an expression for the
593 address of the vtable map variable (for the BASE_CLASS), that will
594 point to the updated data set. BASE_CLASS is the record_type node
595 for the base class whose set of valid vtable pointers we are
596 updating. STR1 and STR2 are all debugging information, to be passed
597 as parameters to __VLTRegisterPairDebug. STR1 represents the name
598 of the vtable map variable to be updated by the call. Similarly,
599 STR2 represents the name of the class whose vtable pointer is being
600 added to the hierarchy. */
601
602static void
603register_other_binfo_vtables (tree binfo, tree base_class,
604 vec<tree> *vtable_ptr_array)
605{
606 unsigned ix;
607 tree base_binfo;
608 tree vtable_decl;
609 bool already_registered;
610
611 if (binfo == NULL_TREE)
612 return;
613
614 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
615 {
616 if ((!BINFO_PRIMARY_P (base_binfo)
617 || BINFO_VIRTUAL_P (base_binfo))
618 && (vtable_decl = get_vtbl_decl_for_binfo (base_binfo)))
619 {
620 tree vtable_address = build_vtbl_address (base_binfo);
621
622 already_registered = check_and_record_registered_pairs
623 (vtable_decl,
624 vtable_address,
625 base_class);
626 if (!already_registered)
627 {
628 vtable_ptr_array->safe_push (vtable_address);
629 current_set_size++;
630 }
631 }
632
633 register_other_binfo_vtables (base_binfo, base_class, vtable_ptr_array);
634 }
635}
636
637/* The set of valid vtable pointers for any given class are stored in
638 a hash table. For reasons of efficiency, that hash table size is
639 always a power of two. In order to try to prevent re-sizing the
640 hash tables very often, we pass __VLTRegisterPair an initial guess
641 as to the number of entries the hashtable will eventually need
642 (rounded up to the nearest power of two). This function takes the
643 class information we have collected for a particular class,
644 CLASS_NODE, and calculates the hash table size guess. */
645
646static int
647guess_num_vtable_pointers (struct vtv_graph_node *class_node)
648{
649 tree vtbl;
650 int total_num_vtbls = 0;
651 int num_vtbls_power_of_two = 1;
652 unsigned i;
653
654 for (i = 0; i < num_vtable_map_nodes; ++i)
655 if (bitmap_bit_p (class_node->descendants, i))
656 {
657 tree class_type = vtbl_map_nodes_vec[i]->class_info->class_type;
658 for (vtbl = CLASSTYPE_VTABLES (class_type); vtbl;
659 vtbl = DECL_CHAIN (vtbl))
660 {
661 total_num_vtbls++;
662 if (total_num_vtbls > num_vtbls_power_of_two)
663 num_vtbls_power_of_two <<= 1;
664 }
665 }
666 return num_vtbls_power_of_two;
667}
668
669/* A simple hash function on strings */
670/* Be careful about changing this routine. The values generated will
671 be stored in the calls to InitSet. So, changing this routine may
672 cause a binary incompatibility. */
673
674static uint32_t
675vtv_string_hash (const char *in)
676{
677 const char *s = in;
678 uint32_t h = 0;
679
680 gcc_assert (in != NULL);
681 for ( ; *s; ++s)
682 h = 5 * h + *s;
683 return h;
684}
685
686static char *
687get_log_file_name (const char *fname)
688{
689 const char *tmp_dir = concat (dump_dir_name, NULL);
690 char *full_name;
691 int dir_len;
692 int fname_len;
693
694 dir_len = strlen (tmp_dir);
695 fname_len = strlen (fname);
696
697 full_name = XNEWVEC (char, dir_len + fname_len + 1);
698 strcpy (full_name, tmp_dir);
699 strcpy (full_name + dir_len, fname);
700
701 return full_name;
702}
703
704static void
705write_out_current_set_data (tree base_class, int set_size)
706{
707 static int class_data_log_fd = -1;
708 char buffer[1024];
709 int bytes_written __attribute__ ((unused));
710 char *file_name = get_log_file_name ("vtv_class_set_sizes.log");
711
712 if (class_data_log_fd == -1)
713 class_data_log_fd = open (file_name,
714 O_WRONLY | O_APPEND | O_CREAT, S_IRWXU);
715
716 if (class_data_log_fd == -1)
717 {
718 warning_at (UNKNOWN_LOCATION, 0,
719 "unable to open log file %<vtv_class_set_sizes.log%>: %m");
720 return;
721 }
722
723 snprintf (buffer, sizeof (buffer), "%s %d\n",
724 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (TYPE_NAME (base_class))),
725 set_size);
726 bytes_written = write (class_data_log_fd, buffer, strlen (buffer));
727}
728
729static tree
730build_key_buffer_arg (tree base_ptr_var_decl)
731{
732 const int key_type_fixed_size = 8;
733 uint32_t len1 = IDENTIFIER_LENGTH (DECL_NAME (base_ptr_var_decl));
734 uint32_t hash_value = vtv_string_hash (IDENTIFIER_POINTER
735 (DECL_NAME (base_ptr_var_decl)));
736 void *key_buffer = xmalloc (len1 + key_type_fixed_size);
737 uint32_t *value_ptr = (uint32_t *) key_buffer;
738 tree ret_value;
739
740 /* Set the len and hash for the string. */
741 *value_ptr = len1;
742 value_ptr++;
743 *value_ptr = hash_value;
744
745 /* Now copy the string representation of the vtbl map name... */
746 memcpy ((char *) key_buffer + key_type_fixed_size,
747 IDENTIFIER_POINTER (DECL_NAME (base_ptr_var_decl)),
748 len1);
749
750 /* ... and build a string literal from it. This will make a copy
751 so the key_bufffer is not needed anymore after this. */
752 ret_value = build_string_literal (len1 + key_type_fixed_size,
753 (char *) key_buffer);
754 free (key_buffer);
755 return ret_value;
756}
757
758static void
759insert_call_to_register_set (tree class_name,
760 vec<tree> *vtbl_ptr_array, tree body, tree arg1,
761 tree arg2, tree size_hint_arg)
762{
763 tree call_expr;
764 int num_args = vtbl_ptr_array->length();
765 char *array_arg_name = ACONCAT (("__vptr_array_",
766 IDENTIFIER_POINTER (class_name), NULL));
767 tree array_arg_type = build_array_type_nelts (build_pointer_type
768 (build_pointer_type
769 (void_type_node)),
770 num_args);
771 tree array_arg = build_decl (UNKNOWN_LOCATION, VAR_DECL,
772 get_identifier (array_arg_name),
773 array_arg_type);
774 int k;
775
776 vec<constructor_elt, va_gc> *array_elements;
777 vec_alloc (array_elements, num_args);
778
779 tree initial = NULL_TREE;
780 tree arg3 = NULL_TREE;
781
782 TREE_PUBLIC (array_arg) = 0;
783 DECL_EXTERNAL (array_arg) = 0;
784 TREE_STATIC (array_arg) = 1;
785 DECL_ARTIFICIAL (array_arg) = 0;
786 TREE_READONLY (array_arg) = 1;
787 DECL_IGNORED_P (array_arg) = 0;
788 DECL_PRESERVE_P (array_arg) = 0;
789 DECL_VISIBILITY (array_arg) = VISIBILITY_HIDDEN;
790
791 for (k = 0; k < num_args; ++k)
792 {
793 CONSTRUCTOR_APPEND_ELT (array_elements, NULL_TREE, (*vtbl_ptr_array)[k]);
794 }
795
796 initial = build_constructor (TREE_TYPE (array_arg), array_elements);
797
798 TREE_CONSTANT (initial) = 1;
799 TREE_STATIC (initial) = 1;
800 DECL_INITIAL (array_arg) = initial;
801 relayout_decl (array_arg);
802 varpool_node::finalize_decl (array_arg);
803
804 arg3 = build1 (ADDR_EXPR, TYPE_POINTER_TO (TREE_TYPE (array_arg)), array_arg);
805
806 TREE_TYPE (arg3) = build_pointer_type (TREE_TYPE (array_arg));
807
808 call_expr = build_call_expr (vlt_register_set_fndecl, 5, arg1,
809 arg2, /* set_symbol_key */
810 size_hint_arg, build_int_cst (size_type_node,
811 num_args),
812 arg3);
813 append_to_statement_list (call_expr, &body);
814 num_calls_to_regset++;
815}
816
817static void
818insert_call_to_register_pair (vec<tree> *vtbl_ptr_array, tree arg1,
819 tree arg2, tree size_hint_arg, tree str1,
820 tree str2, tree body)
821{
822 tree call_expr;
823 int num_args = vtbl_ptr_array->length();
824 tree vtable_address = NULL_TREE;
825
826 if (num_args == 0)
827 vtable_address = build_int_cst (build_pointer_type (void_type_node), 0);
828 else
829 vtable_address = (*vtbl_ptr_array)[0];
830
831 if (flag_vtv_debug)
832 call_expr = build_call_expr (vlt_register_pairs_fndecl, 6, arg1, arg2,
833 size_hint_arg, vtable_address, str1, str2);
834 else
835 call_expr = build_call_expr (vlt_register_pairs_fndecl, 4, arg1, arg2,
836 size_hint_arg, vtable_address);
837
838 append_to_statement_list (call_expr, &body);
839 num_calls_to_regpair++;
840}
841
842static void
843output_set_info (tree record_type, vec<tree> vtbl_ptr_array)
844{
845 static int vtv_debug_log_fd = -1;
846 char buffer[1024];
847 int bytes_written __attribute__ ((unused));
848 int array_len = vtbl_ptr_array.length();
849 const char *class_name =
850 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (TYPE_NAME (record_type)));
851 char *file_name = get_log_file_name ("vtv_set_ptr_data.log");
852
853 if (vtv_debug_log_fd == -1)
854 vtv_debug_log_fd = open (file_name,
855 O_WRONLY | O_APPEND | O_CREAT, S_IRWXU);
856 if (vtv_debug_log_fd == -1)
857 {
858 warning_at (UNKNOWN_LOCATION, 0,
859 "unable to open log file %<vtv_set_ptr_data.log%>: %m");
860 return;
861 }
862
863 for (int i = 0; i < array_len; ++i)
864 {
865 const char *vptr_name = "unknown";
866 int vptr_offset = 0;
867
868 if (TREE_CODE (vtbl_ptr_array[i]) == POINTER_PLUS_EXPR)
869 {
870 tree arg0 = TREE_OPERAND (vtbl_ptr_array[i], 0);
871 tree arg1 = TREE_OPERAND (vtbl_ptr_array[i], 1);
872
873 if (TREE_CODE (arg0) == ADDR_EXPR)
874 arg0 = TREE_OPERAND (arg0, 0);
875
876 if (VAR_P (arg0))
877 vptr_name = IDENTIFIER_POINTER (DECL_NAME (arg0));
878
879 if (TREE_CODE (arg1) == INTEGER_CST)
880 vptr_offset = TREE_INT_CST_LOW (arg1);
881 }
882
883 snprintf (buffer, sizeof (buffer), "%s %s %s + %d\n",
884 main_input_filename, class_name, vptr_name, vptr_offset);
885 bytes_written = write (vtv_debug_log_fd, buffer, strlen(buffer));
886 }
887
888}
889
890/* This function goes through our internal class hierarchy & vtable
891 pointer data structure and outputs calls to __VLTRegisterPair for
892 every class-vptr pair (for those classes whose vtable would be
893 output in the current compilation unit). These calls get put into
894 our constructor initialization function. BODY is the function
895 body, so far, of our constructor initialization function, to which we
896 add the calls. */
897
898static bool
899register_all_pairs (tree body)
900{
901 bool registered_at_least_one = false;
902 vec<tree> *vtbl_ptr_array = NULL;
903 unsigned j;
904
905 for (j = 0; j < num_vtable_map_nodes; ++j)
906 {
907 struct vtbl_map_node *current = vtbl_map_nodes_vec[j];
908 unsigned i = 0;
909 tree base_class = current->class_info->class_type;
910 tree base_ptr_var_decl = current->vtbl_map_decl;
911 tree arg1;
912 tree arg2;
913 tree new_type;
914 tree str1 = NULL_TREE;
915 tree str2 = NULL_TREE;
916 size_t size_hint;
917 tree size_hint_arg;
918
919 gcc_assert (current->class_info != NULL);
920
921
922 if (flag_vtv_debug)
923 str1 = build_string_from_id (DECL_NAME (base_ptr_var_decl));
924
925 new_type = build_pointer_type (TREE_TYPE (base_ptr_var_decl));
926 arg1 = build1 (ADDR_EXPR, new_type, base_ptr_var_decl);
927
928 /* We need a fresh vector for each iteration. */
929 if (vtbl_ptr_array)
930 vec_free (vtbl_ptr_array);
931
932 vec_alloc (vtbl_ptr_array, 10);
933
934 for (i = 0; i < num_vtable_map_nodes; ++i)
935 if (bitmap_bit_p (current->class_info->descendants, i))
936 {
937 struct vtbl_map_node *vtbl_class_node = vtbl_map_nodes_vec[i];
938 tree class_type = vtbl_class_node->class_info->class_type;
939
940 if (class_type
941 && (TREE_CODE (class_type) == RECORD_TYPE))
942 {
943 bool already_registered;
944
945 tree binfo = TYPE_BINFO (class_type);
946 tree vtable_decl;
947 bool vtable_should_be_output = false;
948
949 vtable_decl = CLASSTYPE_VTABLES (class_type);
950
951 /* Handle main vtable for this class. */
952
953 if (vtable_decl)
954 {
955 vtable_should_be_output = TREE_ASM_WRITTEN (vtable_decl);
956 str2 = build_string_from_id (DECL_NAME (vtable_decl));
957 }
958
959 if (vtable_decl && vtable_should_be_output)
960 {
961 tree vtable_address = build_vtbl_address (binfo);
962
963 already_registered = check_and_record_registered_pairs
964 (vtable_decl,
965 vtable_address,
966 base_class);
967
968
969 if (!already_registered)
970 {
971 vtbl_ptr_array->safe_push (vtable_address);
972
973 /* Find and handle any 'extra' vtables associated
974 with this class, via virtual inheritance. */
975 register_construction_vtables (base_class, class_type,
976 vtbl_ptr_array);
977
978 /* Find and handle any 'extra' vtables associated
979 with this class, via multiple inheritance. */
980 register_other_binfo_vtables (binfo, base_class,
981 vtbl_ptr_array);
982 }
983 }
984 }
985 }
986 current_set_size = vtbl_ptr_array->length();
987
988 /* Sometimes we need to initialize the set symbol even if we are
989 not adding any vtable pointers to the set in the current
990 compilation unit. In that case, we need to initialize the
991 set to our best guess as to what the eventual size of the set
992 hash table will be (to prevent having to re-size the hash
993 table later). */
994
995 size_hint = guess_num_vtable_pointers (current->class_info);
996
997 /* If we have added vtable pointers to the set in this
998 compilation unit, adjust the size hint for the set's hash
999 table appropriately. */
1000 if (vtbl_ptr_array->length() > 0)
1001 {
1002 unsigned len = vtbl_ptr_array->length();
1003 while ((size_t) len > size_hint)
1004 size_hint <<= 1;
1005 }
1006 size_hint_arg = build_int_cst (size_type_node, size_hint);
1007
1008 /* Get the key-buffer argument. */
1009 arg2 = build_key_buffer_arg (base_ptr_var_decl);
1010
1011 if (str2 == NULL_TREE)
1012 str2 = build_string_literal (strlen ("unknown") + 1,
1013 "unknown");
1014
1015 if (flag_vtv_debug)
1016 output_set_info (current->class_info->class_type,
1017 *vtbl_ptr_array);
1018
1019 if (vtbl_ptr_array->length() > 1)
1020 {
1021 insert_call_to_register_set (current->class_name,
1022 vtbl_ptr_array, body, arg1, arg2,
1023 size_hint_arg);
1024 registered_at_least_one = true;
1025 }
1026 else
1027 {
1028
1029 if (vtbl_ptr_array->length() > 0
1030 || (current->is_used
1031 || (current->registered->size() > 0)))
1032 {
1033 insert_call_to_register_pair (vtbl_ptr_array,
1034 arg1, arg2, size_hint_arg, str1,
1035 str2, body);
1036 registered_at_least_one = true;
1037 }
1038 }
1039
1040 if (flag_vtv_counts && current_set_size > 0)
1041 write_out_current_set_data (base_class, current_set_size);
1042
1043 }
1044
1045 return registered_at_least_one;
1046}
1047
1048/* Given a tree containing a class type (CLASS_TYPE), this function
1049 finds and returns the class hierarchy node for that class in our
1050 data structure. */
1051
1052static struct vtv_graph_node *
1053find_graph_node (tree class_type)
1054{
1055 struct vtbl_map_node *vtbl_node;
1056
1057 vtbl_node = vtbl_map_get_node (TYPE_MAIN_VARIANT (class_type));
1058 if (vtbl_node)
1059 return vtbl_node->class_info;
1060
1061 return NULL;
1062}
1063
1064/* Add base class/derived class pair to our internal class hierarchy
1065 data structure. BASE_NODE is our vtv_graph_node that corresponds
1066 to a base class. DERIVED_NODE is our vtv_graph_node that
1067 corresponds to a class that is a descendant of the base class
1068 (possibly the base class itself). */
1069
1070static void
1071add_hierarchy_pair (struct vtv_graph_node *base_node,
1072 struct vtv_graph_node *derived_node)
1073{
1074 (base_node->children).safe_push (derived_node);
1075 (derived_node->parents).safe_push (base_node);
1076}
1077
1078/* This functions adds a new base class/derived class relationship to
1079 our class hierarchy data structure. Both parameters are trees
1080 representing the class types, i.e. RECORD_TYPE trees.
1081 DERIVED_CLASS can be the same as BASE_CLASS. */
1082
1083static void
1084update_class_hierarchy_information (tree base_class,
1085 tree derived_class)
1086{
1087 struct vtv_graph_node *base_node = find_graph_node (base_class);
1088 struct vtv_graph_node *derived_node = find_graph_node (derived_class);
1089
1090 add_hierarchy_pair (base_node, derived_node);
1091}
1092
1093
1094static void
1095write_out_vtv_count_data (void)
1096{
1097 static int vtv_count_log_fd = -1;
1098 char buffer[1024];
1099 int unused_vtbl_map_vars = 0;
1100 int bytes_written __attribute__ ((unused));
1101 char *file_name = get_log_file_name ("vtv_count_data.log");
1102
1103 if (vtv_count_log_fd == -1)
1104 vtv_count_log_fd = open (file_name,
1105 O_WRONLY | O_APPEND | O_CREAT, S_IRWXU);
1106 if (vtv_count_log_fd == -1)
1107 {
1108 warning_at (UNKNOWN_LOCATION, 0,
1109 "unable to open log file %<vtv_count_data.log%>: %m");
1110 return;
1111 }
1112
1113 for (unsigned i = 0; i < num_vtable_map_nodes; ++i)
1114 {
1115 struct vtbl_map_node *current = vtbl_map_nodes_vec[i];
1116 if (!current->is_used
1117 && current->registered->size() == 0)
1118 unused_vtbl_map_vars++;
1119 }
1120
1121 snprintf (buffer, sizeof (buffer), "%s %d %d %d %d %d\n",
1122 main_input_filename, total_num_virtual_calls,
1123 total_num_verified_vcalls, num_calls_to_regset,
1124 num_calls_to_regpair, unused_vtbl_map_vars);
1125
1126 bytes_written = write (vtv_count_log_fd, buffer, strlen (buffer));
1127}
1128
1129/* This function calls register_all_pairs, which actually generates
1130 all the calls to __VLTRegisterPair (in the verification constructor
1131 init function). It also generates the calls to
1132 __VLTChangePermission, if the verification constructor init
1133 function is going into the preinit array. INIT_ROUTINE_BODY is
1134 the body of our constructior initialization function, to which we
1135 add our function calls.*/
1136
1137bool
1138vtv_register_class_hierarchy_information (tree init_routine_body)
1139{
1140 bool registered_something = false;
1141
1142 init_functions ();
1143
1144 if (num_vtable_map_nodes == 0)
1145 return false;
1146
1147 /* Add class hierarchy pairs to the vtable map data structure. */
1148 registered_something = register_all_pairs (init_routine_body);
1149
1150 if (flag_vtv_counts)
1151 write_out_vtv_count_data ();
1152
1153 return registered_something;
1154}
1155
1156
1157/* Generate the special constructor function that calls
1158 __VLTChangePermission and __VLTRegisterPairs, and give it a very
1159 high initialization priority. */
1160
1161void
1162vtv_generate_init_routine (void)
1163{
1164 tree init_routine_body;
1165 bool vtable_classes_found = false;
1166
1167 push_lang_context (lang_name_c);
1168
1169 /* The priority for this init function (constructor) is carefully
1170 chosen so that it will happen after the calls to unprotect the
1171 memory used for vtable verification and before the memory is
1172 protected again. */
1173 init_routine_body = vtv_start_verification_constructor_init_function ();
1174
1175 vtable_classes_found =
1176 vtv_register_class_hierarchy_information (init_routine_body);
1177
1178 if (vtable_classes_found)
1179 {
1180 tree vtv_fndecl =
1181 vtv_finish_verification_constructor_init_function (init_routine_body);
1182 TREE_STATIC (vtv_fndecl) = 1;
1183 TREE_USED (vtv_fndecl) = 1;
1184 DECL_PRESERVE_P (vtv_fndecl) = 1;
1185 /* We are running too late to generate any meaningful debug information
1186 for this routine. */
1187 DECL_IGNORED_P (vtv_fndecl) = 1;
1188 if (flag_vtable_verify == VTV_PREINIT_PRIORITY && !TARGET_PECOFF)
1189 DECL_STATIC_CONSTRUCTOR (vtv_fndecl) = 0;
1190
1191 gimplify_function_tree (vtv_fndecl);
1192 cgraph_node::add_new_function (vtv_fndecl, false);
1193
1194 symtab->process_new_functions ();
1195
1196 if (flag_vtable_verify == VTV_PREINIT_PRIORITY && !TARGET_PECOFF)
1197 assemble_vtv_preinit_initializer (vtv_fndecl);
1198
1199 }
1200 pop_lang_context ();
1201}
1202
1203/* This funtion takes a tree containing a class type (BASE_TYPE), and
1204 it either finds the existing vtbl_map_node for that class in our
1205 data structure, or it creates a new node and adds it to the data
1206 structure if there is not one for the class already. As part of
1207 this process it also creates the global vtable map variable for the
1208 class. */
1209
1210struct vtbl_map_node *
1211vtable_find_or_create_map_decl (tree base_type)
1212{
1213 char *var_name = NULL;
1214 struct vtbl_map_node *vtable_map_node = NULL;
1215
1216 /* Verify the type has an associated vtable. */
1217 if (!TYPE_BINFO (base_type) || !BINFO_VTABLE (TYPE_BINFO (base_type)))
1218 return NULL;
1219
1220 /* Create map lookup symbol for base class */
1221 var_name = get_mangled_vtable_map_var_name (base_type);
1222
1223 /* We've already created the variable; just look it. */
1224 vtable_map_node = vtbl_map_get_node (TYPE_MAIN_VARIANT (base_type));
1225
1226 if (!vtable_map_node || (vtable_map_node->vtbl_map_decl == NULL_TREE))
1227 {
1228 /* If we haven't already created the *__vtable_map global
1229 variable for this class, do so now, and add it to the
1230 varpool, to make sure it gets saved and written out. */
1231
1232 tree var_decl = NULL;
1233 tree var_type = build_pointer_type (void_type_node);
1234 tree initial_value = integer_zero_node;
1235
1236 var_decl = build_decl (UNKNOWN_LOCATION, VAR_DECL,
1237 get_identifier (var_name), var_type);
1238
1239 DECL_EXTERNAL (var_decl) = 0;
1240 TREE_STATIC (var_decl) = 1;
1241 DECL_VISIBILITY (var_decl) = VISIBILITY_HIDDEN;
1242 SET_DECL_ASSEMBLER_NAME (var_decl, get_identifier (var_name));
1243 DECL_ARTIFICIAL (var_decl) = 1;
1244 /* We cannot mark this variable as read-only because we want to be
1245 able to write to it at runtime. */
1246 TREE_READONLY (var_decl) = 0;
1247 DECL_IGNORED_P (var_decl) = 1;
1248 DECL_PRESERVE_P (var_decl) = 1;
1249
1250 /* Put these mmap variables in thr .vtable_map_vars section, so
1251 we can find and protect them. */
1252
1253 set_decl_section_name (var_decl, ".vtable_map_vars");
1254 symtab_node::get (var_decl)->implicit_section = true;
1255 DECL_INITIAL (var_decl) = initial_value;
1256
1257 comdat_linkage (var_decl);
1258
1259 varpool_node::finalize_decl (var_decl);
1260 if (!vtable_map_node)
1261 vtable_map_node =
1262 find_or_create_vtbl_map_node (TYPE_MAIN_VARIANT (base_type));
1263 if (vtable_map_node->vtbl_map_decl == NULL_TREE)
1264 vtable_map_node->vtbl_map_decl = var_decl;
1265 }
1266
1267 gcc_assert (vtable_map_node);
1268 return vtable_map_node;
1269}
1270
1271/* This function is used to build up our class hierarchy data for a
1272 particular class. TYPE is the record_type tree node for the
1273 class. */
1274
1275static void
1276vtv_insert_single_class_info (tree type)
1277{
1278 if (flag_vtable_verify)
1279 {
1280 tree binfo = TYPE_BINFO (type);
1281 tree base_binfo;
1282 struct vtbl_map_node *own_map;
1283 int i;
1284
1285 /* First make sure to create the map for this record type. */
1286 own_map = vtable_find_or_create_map_decl (type);
1287 if (own_map == NULL)
1288 return;
1289
1290 /* Go through the list of all base classes for the current
1291 (derived) type, make sure the *__vtable_map global variable
1292 for the base class exists, and add the base class/derived
1293 class pair to the class hierarchy information we are
1294 accumulating (for vtable pointer verification). */
1295 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1296 {
1297 tree tree_val = BINFO_TYPE (base_binfo);
1298 struct vtbl_map_node *vtable_map_node = NULL;
1299
1300 vtable_map_node = vtable_find_or_create_map_decl (tree_val);
1301
1302 if (vtable_map_node != NULL)
1303 update_class_hierarchy_information (tree_val, type);
1304 }
1305 }
1306}
1307
1308/* This function adds classes we are interested in to a list of
1309 classes. RECORD is the record_type node for the class we are
1310 adding to the list. */
1311
1312void
1313vtv_save_class_info (tree record)
1314{
1315 if (!flag_vtable_verify || TREE_CODE (record) == UNION_TYPE)
1316 return;
1317
1318 if (!vlt_saved_class_info)
1319 vec_alloc (vlt_saved_class_info, 10);
1320
1321 gcc_assert (TREE_CODE (record) == RECORD_TYPE);
1322
1323 vec_safe_push (vlt_saved_class_info, record);
1324}
1325
1326
1327/* This function goes through the list of classes we saved and calls
1328 vtv_insert_single_class_info on each one, to build up our class
1329 hierarchy data structure. */
1330
1331void
1332vtv_recover_class_info (void)
1333{
1334 tree current_class;
1335 unsigned i;
1336
1337 if (vlt_saved_class_info)
1338 {
1339 for (i = 0; i < vlt_saved_class_info->length(); ++i)
1340 {
1341 current_class = (*vlt_saved_class_info)[i];
1342 gcc_assert (TREE_CODE (current_class) == RECORD_TYPE);
1343 vtv_insert_single_class_info (current_class);
1344 }
1345 }
1346}
1347
1348#include "gt-cp-vtable-class-hierarchy.h"
1349