1 /* Copyright (C) 2013-2014 Free Software Foundation, Inc.
3 This file is part of GCC.
5 GCC is free software; you can redistribute it and/or modify it under
6 the terms of the GNU General Public License as published by the Free
7 Software Foundation; either version 3, or (at your option) any later
10 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
11 WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 You should have received a copy of the GNU General Public License
16 along with GCC; see the file COPYING3. If not see
17 <http://www.gnu.org/licenses/>. */
19 /* Virtual Table Pointer Security Pass - Detect corruption of vtable pointers
20 before using them for virtual method dispatches. */
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
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
53 To find and reference the set of valid vtable pointers for any given
54 virtual class, we create a special global variable 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.
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
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.
103 This file contains code for the tree pass that goes through all the
104 statements in each basic block, looking for virtual calls, and
105 inserting a call to __VLTVerifyVtablePointer (with appropriate
106 arguments) before each one. It also contains the hash table
107 functions for the data structures used for collecting the class
108 hierarchy data and building/maintaining the vtable map variable data
109 are defined in gcc/vtable-verify.h. These data structures are
110 shared with the code in the C++ front end that collects the class
111 hierarchy & vtable information and generates the vtable map
112 variables (see cp/vtable-class-hierarchy.c). This tree pass should
113 run just before the gimple is converted to RTL.
115 Some implementation details for this pass:
117 To find all of the virtual calls, we iterate through all the
118 gimple statements in each basic block, looking for any call
119 statement with the code "OBJ_TYPE_REF". Once we have found the
120 virtual call, we need to find the vtable pointer through which the
121 call is being made, and the type of the object containing the
122 pointer (to find the appropriate vtable map variable). We then use
123 these to build a call to __VLTVerifyVtablePointer, passing the
124 vtable map variable, and the vtable pointer. We insert the
125 verification call just after the gimple statement that gets the
126 vtable pointer out of the object, and we update the next
127 statement to depend on the result returned from
128 __VLTVerifyVtablePointer (the vtable pointer value), to ensure
129 subsequent compiler phases don't remove or reorder the call (it's no
130 good to have the verification occur after the virtual call, for
131 example). To find the vtable pointer being used (and the type of
132 the object) we search backwards through the def_stmts chain from the
133 virtual call (see verify_bb_vtables for more details). */
137 #include "coretypes.h"
139 #include "basic-block.h"
140 #include "tree-ssa-alias.h"
141 #include "internal-fn.h"
142 #include "gimple-expr.h"
145 #include "gimple-iterator.h"
146 #include "gimple-ssa.h"
147 #include "tree-phinodes.h"
148 #include "ssa-iterators.h"
149 #include "stringpool.h"
150 #include "tree-ssanames.h"
151 #include "tree-pass.h"
154 #include "vtable-verify.h"
156 unsigned num_vtable_map_nodes
= 0;
157 int total_num_virtual_calls
= 0;
158 int total_num_verified_vcalls
= 0;
160 extern GTY(()) tree verify_vtbl_ptr_fndecl
;
161 tree verify_vtbl_ptr_fndecl
= NULL_TREE
;
163 /* Keep track of whether or not any virtual call were verified. */
164 static bool any_verification_calls_generated
= false;
166 unsigned int vtable_verify_main (void);
169 /* The following few functions are for the vtbl pointer hash table
170 in the 'registered' field of the struct vtable_map_node. The hash
171 table keeps track of which vtable pointers have been used in
172 calls to __VLTRegisterPair with that particular vtable map variable. */
174 /* This function checks to see if a particular VTABLE_DECL and OFFSET are
175 already in the 'registered' hash table for NODE. */
178 vtbl_map_node_registration_find (struct vtbl_map_node
*node
,
182 struct vtable_registration key
;
183 struct vtable_registration
**slot
;
185 gcc_assert (node
&& node
->registered
.is_created ());
187 key
.vtable_decl
= vtable_decl
;
188 slot
= (struct vtable_registration
**) node
->registered
.find_slot (&key
,
194 for (i
= 0; i
< ((*slot
)->offsets
).length (); ++i
)
195 if ((*slot
)->offsets
[i
] == offset
)
202 /* This function inserts VTABLE_DECL and OFFSET into the 'registered'
203 hash table for NODE. It returns a boolean indicating whether or not
204 it actually inserted anything. */
207 vtbl_map_node_registration_insert (struct vtbl_map_node
*node
,
211 struct vtable_registration key
;
212 struct vtable_registration
**slot
;
213 bool inserted_something
= false;
215 if (!node
|| !node
->registered
.is_created ())
218 key
.vtable_decl
= vtable_decl
;
219 slot
= (struct vtable_registration
**) node
->registered
.find_slot (&key
,
224 struct vtable_registration
*node
;
225 node
= XNEW (struct vtable_registration
);
226 node
->vtable_decl
= vtable_decl
;
228 (node
->offsets
).create (10);
229 (node
->offsets
).safe_push (offset
);
231 inserted_something
= true;
235 /* We found the vtable_decl slot; we need to see if it already
236 contains the offset. If not, we need to add the offset. */
239 for (i
= 0; i
< ((*slot
)->offsets
).length () && !found
; ++i
)
240 if ((*slot
)->offsets
[i
] == offset
)
245 ((*slot
)->offsets
).safe_push (offset
);
246 inserted_something
= true;
249 return inserted_something
;
252 /* Hashtable functions for vtable_registration hashtables. */
255 registration_hasher::hash (const value_type
*p
)
257 const struct vtable_registration
*n
= (const struct vtable_registration
*) p
;
258 return (hashval_t
) (DECL_UID (n
->vtable_decl
));
262 registration_hasher::equal (const value_type
*p1
, const compare_type
*p2
)
264 const struct vtable_registration
*n1
=
265 (const struct vtable_registration
*) p1
;
266 const struct vtable_registration
*n2
=
267 (const struct vtable_registration
*) p2
;
268 return (DECL_UID (n1
->vtable_decl
) == DECL_UID (n2
->vtable_decl
));
271 /* End of hashtable functions for "registered" hashtables. */
275 /* Hashtable definition and functions for vtbl_map_hash. */
277 struct vtbl_map_hasher
: typed_noop_remove
<struct vtbl_map_node
>
279 typedef struct vtbl_map_node value_type
;
280 typedef struct vtbl_map_node compare_type
;
281 static inline hashval_t
hash (const value_type
*);
282 static inline bool equal (const value_type
*, const compare_type
*);
285 /* Returns a hash code for P. */
288 vtbl_map_hasher::hash (const value_type
*p
)
290 const struct vtbl_map_node n
= *((const struct vtbl_map_node
*) p
);
291 return (hashval_t
) IDENTIFIER_HASH_VALUE (n
.class_name
);
294 /* Returns nonzero if P1 and P2 are equal. */
297 vtbl_map_hasher::equal (const value_type
*p1
, const compare_type
*p2
)
299 const struct vtbl_map_node n1
= *((const struct vtbl_map_node
*) p1
);
300 const struct vtbl_map_node n2
= *((const struct vtbl_map_node
*) p2
);
301 return (IDENTIFIER_HASH_VALUE (n1
.class_name
) ==
302 IDENTIFIER_HASH_VALUE (n2
.class_name
));
305 /* Here are the two structures into which we insert vtable map nodes.
306 We use two data structures because of the vastly different ways we need
307 to find the nodes for various tasks (see comments in vtable-verify.h
310 typedef hash_table
<vtbl_map_hasher
> vtbl_map_table_type
;
311 typedef vtbl_map_table_type::iterator vtbl_map_iterator_type
;
313 /* Vtable map variable nodes stored in a hash table. */
314 static vtbl_map_table_type vtbl_map_hash
;
316 /* Vtable map variable nodes stored in a vector. */
317 vec
<struct vtbl_map_node
*> vtbl_map_nodes_vec
;
319 /* Return vtbl_map node for CLASS_NAME without creating a new one. */
321 struct vtbl_map_node
*
322 vtbl_map_get_node (tree class_type
)
324 struct vtbl_map_node key
;
325 struct vtbl_map_node
**slot
;
327 tree class_type_decl
;
329 unsigned int type_quals
;
331 if (!vtbl_map_hash
.is_created ())
334 gcc_assert (TREE_CODE (class_type
) == RECORD_TYPE
);
337 /* Find the TYPE_DECL for the class. */
338 class_type_decl
= TYPE_NAME (class_type
);
340 /* Verify that there aren't any qualifiers on the type. */
341 type_quals
= TYPE_QUALS (TREE_TYPE (class_type_decl
));
342 gcc_assert (type_quals
== TYPE_UNQUALIFIED
);
344 /* Get the mangled name for the unqualified type. */
345 gcc_assert (HAS_DECL_ASSEMBLER_NAME_P (class_type_decl
));
346 class_name
= DECL_ASSEMBLER_NAME (class_type_decl
);
348 key
.class_name
= class_name
;
349 slot
= (struct vtbl_map_node
**) vtbl_map_hash
.find_slot (&key
,
356 /* Return vtbl_map node assigned to BASE_CLASS_TYPE. Create new one
359 struct vtbl_map_node
*
360 find_or_create_vtbl_map_node (tree base_class_type
)
362 struct vtbl_map_node key
;
363 struct vtbl_map_node
*node
;
364 struct vtbl_map_node
**slot
;
365 tree class_type_decl
;
366 unsigned int type_quals
;
368 if (!vtbl_map_hash
.is_created ())
369 vtbl_map_hash
.create (10);
371 /* Find the TYPE_DECL for the class. */
372 class_type_decl
= TYPE_NAME (base_class_type
);
374 /* Verify that there aren't any type qualifiers on type. */
375 type_quals
= TYPE_QUALS (TREE_TYPE (class_type_decl
));
376 gcc_assert (type_quals
== TYPE_UNQUALIFIED
);
378 gcc_assert (HAS_DECL_ASSEMBLER_NAME_P (class_type_decl
));
379 key
.class_name
= DECL_ASSEMBLER_NAME (class_type_decl
);
380 slot
= (struct vtbl_map_node
**) vtbl_map_hash
.find_slot (&key
,
386 node
= XNEW (struct vtbl_map_node
);
387 node
->vtbl_map_decl
= NULL_TREE
;
388 node
->class_name
= key
.class_name
;
389 node
->uid
= num_vtable_map_nodes
++;
391 node
->class_info
= XNEW (struct vtv_graph_node
);
392 node
->class_info
->class_type
= base_class_type
;
393 node
->class_info
->class_uid
= node
->uid
;
394 node
->class_info
->num_processed_children
= 0;
396 (node
->class_info
->parents
).create (4);
397 (node
->class_info
->children
).create (4);
399 node
->registered
.create (16);
401 node
->is_used
= false;
403 vtbl_map_nodes_vec
.safe_push (node
);
404 gcc_assert (vtbl_map_nodes_vec
[node
->uid
] == node
);
410 /* End of hashtable functions for vtable_map variables hash table. */
412 /* Given a gimple STMT, this function checks to see if the statement
413 is an assignment, the rhs of which is getting the vtable pointer
414 value out of an object. (i.e. it's the value we need to verify
415 because its the vtable pointer that will be used for a virtual
419 is_vtable_assignment_stmt (gimple stmt
)
422 if (gimple_code (stmt
) != GIMPLE_ASSIGN
)
426 tree lhs
= gimple_assign_lhs (stmt
);
427 tree rhs
= gimple_assign_rhs1 (stmt
);
429 if (TREE_CODE (lhs
) != SSA_NAME
)
432 if (TREE_CODE (rhs
) != COMPONENT_REF
)
435 if (! (TREE_OPERAND (rhs
, 1))
436 || (TREE_CODE (TREE_OPERAND (rhs
, 1)) != FIELD_DECL
))
439 if (! DECL_VIRTUAL_P (TREE_OPERAND (rhs
, 1)))
446 /* This function attempts to recover the declared class of an object
447 that is used in making a virtual call. We try to get the type from
448 the type cast in the gimple assignment statement that extracts the
449 vtable pointer from the object (DEF_STMT). The gimple statement
450 usually looks something like this:
452 D.2201_4 = MEM[(struct Event *)this_1(D)]._vptr.Event */
455 extract_object_class_type (tree rhs
)
457 tree result
= NULL_TREE
;
459 /* Try to find and extract the type cast from that stmt. */
460 if (TREE_CODE (rhs
) == COMPONENT_REF
)
462 tree op0
= TREE_OPERAND (rhs
, 0);
463 tree op1
= TREE_OPERAND (rhs
, 1);
465 if (TREE_CODE (op1
) == FIELD_DECL
466 && DECL_VIRTUAL_P (op1
))
468 if (TREE_CODE (op0
) == COMPONENT_REF
469 && TREE_CODE (TREE_OPERAND (op0
, 0)) == MEM_REF
470 && TREE_CODE (TREE_TYPE (TREE_OPERAND (op0
, 0)))== RECORD_TYPE
)
471 result
= TREE_TYPE (TREE_OPERAND (op0
, 0));
473 result
= TREE_TYPE (op0
);
475 else if (TREE_CODE (op0
) == COMPONENT_REF
)
477 result
= extract_object_class_type (op0
);
478 if (result
== NULL_TREE
479 && TREE_CODE (op1
) == COMPONENT_REF
)
480 result
= extract_object_class_type (op1
);
487 /* This function traces forward through the def-use chain of an SSA
488 variable to see if it ever gets used in a virtual function call. It
489 returns a boolean indicating whether or not it found a virtual call in
493 var_is_used_for_virtual_call_p (tree lhs
, int *mem_ref_depth
)
495 imm_use_iterator imm_iter
;
496 bool found_vcall
= false;
499 if (TREE_CODE (lhs
) != SSA_NAME
)
502 if (*mem_ref_depth
> 2)
505 /* Iterate through the immediate uses of the current variable. If
506 it's a virtual function call, we're done. Otherwise, if there's
507 an LHS for the use stmt, add the ssa var to the work list
508 (assuming it's not already in the list and is not a variable
509 we've already examined. */
511 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, lhs
)
513 gimple stmt2
= USE_STMT (use_p
);
515 if (is_gimple_call (stmt2
))
517 tree fncall
= gimple_call_fn (stmt2
);
518 if (fncall
&& TREE_CODE (fncall
) == OBJ_TYPE_REF
)
523 else if (gimple_code (stmt2
) == GIMPLE_PHI
)
525 found_vcall
= var_is_used_for_virtual_call_p
526 (gimple_phi_result (stmt2
),
529 else if (is_gimple_assign (stmt2
))
531 tree rhs
= gimple_assign_rhs1 (stmt2
);
532 if (TREE_CODE (rhs
) == ADDR_EXPR
533 || TREE_CODE (rhs
) == MEM_REF
)
534 *mem_ref_depth
= *mem_ref_depth
+ 1;
536 if (TREE_CODE (rhs
) == COMPONENT_REF
)
538 while (TREE_CODE (TREE_OPERAND (rhs
, 0)) == COMPONENT_REF
)
539 rhs
= TREE_OPERAND (rhs
, 0);
541 if (TREE_CODE (TREE_OPERAND (rhs
, 0)) == ADDR_EXPR
542 || TREE_CODE (TREE_OPERAND (rhs
, 0)) == MEM_REF
)
543 *mem_ref_depth
= *mem_ref_depth
+ 1;
546 if (*mem_ref_depth
< 3)
547 found_vcall
= var_is_used_for_virtual_call_p
548 (gimple_assign_lhs (stmt2
),
562 /* Search through all the statements in a basic block (BB), searching
563 for virtual method calls. For each virtual method dispatch, find
564 the vptr value used, and the statically declared type of the
565 object; retrieve the vtable map variable for the type of the
566 object; generate a call to __VLTVerifyVtablePointer; and insert the
567 generated call into the basic block, after the point where the vptr
568 value is gotten out of the object and before the virtual method
569 dispatch. Make the virtual method dispatch depend on the return
570 value from the verification call, so that subsequent optimizations
571 cannot reorder the two calls. */
574 verify_bb_vtables (basic_block bb
)
578 gimple_stmt_iterator gsi_vtbl_assign
;
579 gimple_stmt_iterator gsi_virtual_call
;
582 gsi_virtual_call
= gsi_start (stmts
);
583 for (; !gsi_end_p (gsi_virtual_call
); gsi_next (&gsi_virtual_call
))
585 stmt
= gsi_stmt (gsi_virtual_call
);
587 /* Count virtual calls. */
588 if (is_gimple_call (stmt
))
590 tree fncall
= gimple_call_fn (stmt
);
591 if (fncall
&& TREE_CODE (fncall
) == OBJ_TYPE_REF
)
592 total_num_virtual_calls
++;
595 if (is_vtable_assignment_stmt (stmt
))
597 tree lhs
= gimple_assign_lhs (stmt
);
598 tree vtbl_var_decl
= NULL_TREE
;
599 struct vtbl_map_node
*vtable_map_node
;
600 tree vtbl_decl
= NULL_TREE
;
602 const char *vtable_name
= "<unknown>";
605 int mem_ref_depth
= 0;
607 /* Make sure this vptr field access is for a virtual call. */
608 if (!var_is_used_for_virtual_call_p (lhs
, &mem_ref_depth
))
611 /* Now we have found the virtual method dispatch and
612 the preceding access of the _vptr.* field... Next
613 we need to find the statically declared type of
614 the object, so we can find and use the right
615 vtable map variable in the verification call. */
616 tree class_type
= extract_object_class_type
617 (gimple_assign_rhs1 (stmt
));
619 gsi_vtbl_assign
= gsi_for_stmt (stmt
);
622 && (TREE_CODE (class_type
) == RECORD_TYPE
)
623 && TYPE_BINFO (class_type
))
625 /* Get the vtable VAR_DECL for the type. */
626 vtbl_var_decl
= BINFO_VTABLE (TYPE_BINFO (class_type
));
628 if (TREE_CODE (vtbl_var_decl
) == POINTER_PLUS_EXPR
)
629 vtbl_var_decl
= TREE_OPERAND (TREE_OPERAND (vtbl_var_decl
, 0),
632 gcc_assert (vtbl_var_decl
);
634 vtbl_decl
= vtbl_var_decl
;
635 vtable_map_node
= vtbl_map_get_node
636 (TYPE_MAIN_VARIANT (class_type
));
638 gcc_assert (verify_vtbl_ptr_fndecl
);
640 /* Given the vtable pointer for the base class of the
641 object, build the call to __VLTVerifyVtablePointer to
642 verify that the object's vtable pointer (contained in
643 lhs) is in the set of valid vtable pointers for the
646 if (vtable_map_node
&& vtable_map_node
->vtbl_map_decl
)
648 vtable_map_node
->is_used
= true;
649 vtbl_var_decl
= vtable_map_node
->vtbl_map_decl
;
651 if (TREE_CODE (vtbl_decl
) == VAR_DECL
)
652 vtable_name
= IDENTIFIER_POINTER (DECL_NAME (vtbl_decl
));
654 /* Call different routines if we are interested in
655 trace information to debug problems. */
658 int len1
= IDENTIFIER_LENGTH
659 (DECL_NAME (vtbl_var_decl
));
660 int len2
= strlen (vtable_name
);
662 call_stmt
= gimple_build_call
663 (verify_vtbl_ptr_fndecl
, 4,
666 (TREE_TYPE (vtbl_var_decl
)),
674 build_string_literal (len2
+ 1,
678 call_stmt
= gimple_build_call
679 (verify_vtbl_ptr_fndecl
, 2,
682 (TREE_TYPE (vtbl_var_decl
)),
687 /* Create a new SSA_NAME var to hold the call's
688 return value, and make the call_stmt use the
689 variable for that purpose. */
690 tmp0
= make_temp_ssa_name (TREE_TYPE (lhs
), NULL
, "VTV");
691 gimple_call_set_lhs (call_stmt
, tmp0
);
692 update_stmt (call_stmt
);
694 /* Replace all uses of lhs with tmp0. */
696 imm_use_iterator iterator
;
698 FOR_EACH_IMM_USE_STMT (use_stmt
, iterator
, lhs
)
701 if (use_stmt
== call_stmt
)
703 FOR_EACH_IMM_USE_ON_STMT (use_p
, iterator
)
704 SET_USE (use_p
, tmp0
);
705 update_stmt (use_stmt
);
711 /* Insert the new verification call just after the
712 statement that gets the vtable pointer out of the
714 gcc_assert (gsi_stmt (gsi_vtbl_assign
) == stmt
);
715 gsi_insert_after (&gsi_vtbl_assign
, call_stmt
,
718 any_verification_calls_generated
= true;
719 total_num_verified_vcalls
++;
726 /* Main function, called from pass->excute(). Loop through all the
727 basic blocks in the current function, passing them to
728 verify_bb_vtables, which searches for virtual calls, and inserts
729 calls to __VLTVerifyVtablePointer. */
732 vtable_verify_main (void)
734 unsigned int ret
= 1;
737 FOR_ALL_BB_FN (bb
, cfun
)
738 verify_bb_vtables (bb
);
743 /* Gate function for the pass. */
746 gate_tree_vtable_verify (void)
748 return (flag_vtable_verify
);
751 /* Definition of this optimization pass. */
755 const pass_data pass_data_vtable_verify
=
757 GIMPLE_PASS
, /* type */
758 "vtable-verify", /* name */
759 OPTGROUP_NONE
, /* optinfo_flags */
760 true, /* has_execute */
761 TV_VTABLE_VERIFICATION
, /* tv_id */
762 ( PROP_cfg
| PROP_ssa
), /* properties_required */
763 0, /* properties_provided */
764 0, /* properties_destroyed */
765 0, /* todo_flags_start */
766 TODO_update_ssa
, /* todo_flags_finish */
769 class pass_vtable_verify
: public gimple_opt_pass
772 pass_vtable_verify (gcc::context
*ctxt
)
773 : gimple_opt_pass (pass_data_vtable_verify
, ctxt
)
776 /* opt_pass methods: */
777 bool gate () { return gate_tree_vtable_verify (); }
778 unsigned int execute () { return vtable_verify_main (); }
780 }; // class pass_vtable_verify
785 make_pass_vtable_verify (gcc::context
*ctxt
)
787 return new pass_vtable_verify (ctxt
);
790 #include "gt-vtable-verify.h"