gcc/ipa-chkp.c

   1 /* Pointer Bounds Checker IPA passes.
   2    Copyright (C) 2014-2015 Free Software Foundation, Inc.
   3    Contributed by Ilya Enkovich (ilya.enkovich@intel.com)
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "hash-set.h"
  25 #include "machmode.h"
  26 #include "vec.h"
  27 #include "double-int.h"
  28 #include "input.h"
  29 #include "alias.h"
  30 #include "symtab.h"
  31 #include "options.h"
  32 #include "wide-int.h"
  33 #include "inchash.h"
  34 #include "tree.h"
  35 #include "fold-const.h"
  36 #include "stor-layout.h"
  37 #include "tree-pass.h"
  38 #include "stringpool.h"
  39 #include "bitmap.h"
  40 #include "gimple-expr.h"
  41 #include "tm.h"
  42 #include "hard-reg-set.h"
  43 #include "function.h"
  44 #include "is-a.h"
  45 #include "tree-ssa-alias.h"
  46 #include "predict.h"
  47 #include "basic-block.h"
  48 #include "gimple.h"
  49 #include "ipa-ref.h"
  50 #include "lto-streamer.h"
  51 #include "cgraph.h"
  52 #include "tree-chkp.h"
  53 #include "tree-inline.h"
  54 #include "ipa-chkp.h"
  55
  56 /*  Pointer Bounds Checker has two IPA passes to support code instrumentation.
  57
  58     In instrumented code each pointer is provided with bounds.  For input
  59     pointer parameters it means we also have bounds passed.  For calls it
  60     means we have additional bounds arguments for pointer arguments.
  61
  62     To have all IPA optimizations working correctly we have to express
  63     dataflow between passed and received bounds explicitly via additional
  64     entries in function declaration arguments list and in function type.
  65     Since we may have both instrumented and not instrumented code at the
  66     same time, we cannot replace all original functions with their
  67     instrumented variants.  Therefore we create clones (versions) instead.
  68
  69     Instrumentation clones creation is a separate IPA pass which is a part
  70     of early local passes.  Clones are created after SSA is built (because
  71     instrumentation pass works on SSA) and before any transformations
  72     which may change pointer flow and therefore lead to incorrect code
  73     instrumentation (possibly causing false bounds check failures).
  74
  75     Instrumentation clones have pointer bounds arguments added right after
  76     pointer arguments.  Clones have assembler name of the original
  77     function with suffix added.  New assembler name is in transparent
  78     alias chain with the original name.  Thus we expect all calls to the
  79     original and instrumented functions look similar in assembler.
  80
  81     During instrumentation versioning pass we create instrumented versions
  82     of all function with body and also for all their aliases and thunks.
  83     Clones for functions with no body are created on demand (usually
  84     during call instrumentation).
  85
  86     Original and instrumented function nodes are connected with IPA
  87     reference IPA_REF_CHKP.  It is mostly done to have reachability
  88     analysis working correctly.  We may have no references to the
  89     instrumented function in the code but it still should be counted
  90     as reachable if the original function is reachable.
  91
  92     When original function bodies are not needed anymore we release
  93     them and transform functions into a special kind of thunks.  Each
  94     thunk has a call edge to the instrumented version.  These thunks
  95     help to keep externally visible instrumented functions visible
  96     when linker resolution files are used.  Linker has no info about
  97     connection between original and instrumented function and
  98     therefore we may wrongly decide (due to difference in assembler
  99     names) that instrumented function version is local and can be
 100     removed.  */
 101
 102 #define CHKP_BOUNDS_OF_SYMBOL_PREFIX "__chkp_bounds_of_"
 103
 104 /* Build a clone of FNDECL with a modified name.  */
 105
 106 static tree
 107 chkp_build_instrumented_fndecl (tree fndecl)
 108 {
 109   tree new_decl = copy_node (fndecl);
 110   tree new_name;
 111   std::string s;
 112
 113   /* called_as_built_in checks DECL_NAME to identify calls to
 114      builtins.  We want instrumented calls to builtins to be
 115      recognized by called_as_built_in.  Therefore use original
 116      DECL_NAME for cloning with no prefixes.  */
 117   s = IDENTIFIER_POINTER (DECL_NAME (fndecl));
 118   s += ".chkp";
 119   DECL_NAME (new_decl) = get_identifier (s.c_str ());
 120
 121   /* References to the original and to the instrumented version
 122      should look the same in the output assembly.  And we cannot
 123      use the same assembler name for the instrumented version
 124      because it conflicts with decl merging algorithms in LTO.
 125      Achieve the result by using transparent alias name for the
 126      instrumented version.  */
 127   s = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl));
 128   s += ".chkp";
 129   new_name = get_identifier (s.c_str ());
 130   IDENTIFIER_TRANSPARENT_ALIAS (new_name) = 1;
 131   TREE_CHAIN (new_name) = DECL_ASSEMBLER_NAME (fndecl);
 132   SET_DECL_ASSEMBLER_NAME (new_decl, new_name);
 133
 134   /* For functions with body versioning will make a copy of arguments.
 135      For functions with no body we need to do it here.  */
 136   if (!gimple_has_body_p (fndecl))
 137     DECL_ARGUMENTS (new_decl) = copy_list (DECL_ARGUMENTS (fndecl));
 138
 139   /* We are going to modify attributes list and therefore should
 140      make own copy.  */
 141   DECL_ATTRIBUTES (new_decl) = copy_list (DECL_ATTRIBUTES (fndecl));
 142
 143   /* Change builtin function code.  */
 144   if (DECL_BUILT_IN (new_decl))
 145     {
 146       gcc_assert (DECL_BUILT_IN_CLASS (new_decl) == BUILT_IN_NORMAL);
 147       gcc_assert (DECL_FUNCTION_CODE (new_decl) < BEGIN_CHKP_BUILTINS);
 148       DECL_FUNCTION_CODE (new_decl)
 149         = (enum built_in_function)(DECL_FUNCTION_CODE (new_decl)
 150                                    + BEGIN_CHKP_BUILTINS + 1);
 151     }
 152
 153   return new_decl;
 154 }
 155
 156
 157 /* Fix operands of attribute from ATTRS list named ATTR_NAME.
 158    Integer operands are replaced with values according to
 159    INDEXES map having LEN elements.  For operands out of len
 160    we just add DELTA.  */
 161
 162 static void
 163 chkp_map_attr_arg_indexes (tree attrs, const char *attr_name,
 164                            unsigned *indexes, int len, int delta)
 165 {
 166   tree attr = lookup_attribute (attr_name, attrs);
 167   tree op;
 168
 169   if (!attr)
 170     return;
 171
 172   TREE_VALUE (attr) = copy_list (TREE_VALUE (attr));
 173   for (op = TREE_VALUE (attr); op; op = TREE_CHAIN (op))
 174     {
 175       int idx;
 176
 177       if (TREE_CODE (TREE_VALUE (op)) != INTEGER_CST)
 178         continue;
 179
 180       idx = TREE_INT_CST_LOW (TREE_VALUE (op));
 181
 182       /* If idx exceeds indexes length then we just
 183          keep it at the same distance from the last
 184          known arg.  */
 185       if (idx > len)
 186         idx += delta;
 187       else
 188         idx = indexes[idx - 1] + 1;
 189       TREE_VALUE (op) = build_int_cst (TREE_TYPE (TREE_VALUE (op)), idx);
 190     }
 191 }
 192
 193 /* Make a copy of function type ORIG_TYPE adding pointer
 194    bounds as additional arguments.  */
 195
 196 tree
 197 chkp_copy_function_type_adding_bounds (tree orig_type)
 198 {
 199   tree type;
 200   tree arg_type, attrs, t;
 201   unsigned len = list_length (TYPE_ARG_TYPES (orig_type));
 202   unsigned *indexes = XALLOCAVEC (unsigned, len);
 203   unsigned idx = 0, new_idx = 0;
 204
 205   for (arg_type = TYPE_ARG_TYPES (orig_type);
 206        arg_type;
 207        arg_type = TREE_CHAIN (arg_type))
 208     if (TREE_VALUE (arg_type) == void_type_node)
 209       continue;
 210     else if (BOUNDED_TYPE_P (TREE_VALUE (arg_type))
 211              || pass_by_reference (NULL, TYPE_MODE (TREE_VALUE (arg_type)),
 212                                    TREE_VALUE (arg_type), true)
 213              || chkp_type_has_pointer (TREE_VALUE (arg_type)))
 214       break;
 215
 216   /* We may use original type if there are no bounds passed.  */
 217   if (!arg_type)
 218     return orig_type;
 219
 220   type = copy_node (orig_type);
 221   TYPE_ARG_TYPES (type) = copy_list (TYPE_ARG_TYPES (type));
 222
 223   for (arg_type = TYPE_ARG_TYPES (type);
 224        arg_type;
 225        arg_type = TREE_CHAIN (arg_type))
 226     {
 227       indexes[idx++] = new_idx++;
 228
 229       /* pass_by_reference returns 1 for void type,
 230          so check for it first.  */
 231       if (TREE_VALUE (arg_type) == void_type_node)
 232         continue;
 233       else if (BOUNDED_TYPE_P (TREE_VALUE (arg_type))
 234                || pass_by_reference (NULL, TYPE_MODE (TREE_VALUE (arg_type)),
 235                                      TREE_VALUE (arg_type), true))
 236         {
 237           tree new_type = build_tree_list (NULL_TREE,
 238                                            pointer_bounds_type_node);
 239           TREE_CHAIN (new_type) = TREE_CHAIN (arg_type);
 240           TREE_CHAIN (arg_type) = new_type;
 241
 242           arg_type = TREE_CHAIN (arg_type);
 243           new_idx++;
 244         }
 245       else if (chkp_type_has_pointer (TREE_VALUE (arg_type)))
 246         {
 247           bitmap slots = BITMAP_ALLOC (NULL);
 248           bitmap_iterator bi;
 249           unsigned bnd_no;
 250
 251           chkp_find_bound_slots (TREE_VALUE (arg_type), slots);
 252
 253           EXECUTE_IF_SET_IN_BITMAP (slots, 0, bnd_no, bi)
 254             {
 255               tree new_type = build_tree_list (NULL_TREE,
 256                                                pointer_bounds_type_node);
 257               TREE_CHAIN (new_type) = TREE_CHAIN (arg_type);
 258               TREE_CHAIN (arg_type) = new_type;
 259
 260               arg_type = TREE_CHAIN (arg_type);
 261               new_idx++;
 262             }
 263           BITMAP_FREE (slots);
 264         }
 265     }
 266
 267   /* If function type has attribute with arg indexes then
 268      we have to copy it fixing attribute ops.  Map for
 269      fixing is in indexes array.  */
 270   attrs = TYPE_ATTRIBUTES (type);
 271   if (lookup_attribute ("nonnull", attrs)
 272       || lookup_attribute ("format", attrs)
 273       || lookup_attribute ("format_arg", attrs))
 274     {
 275       int delta = new_idx - len;
 276       attrs = copy_list (TYPE_ATTRIBUTES (type));
 277       chkp_map_attr_arg_indexes (attrs, "nonnull", indexes, len, delta);
 278       chkp_map_attr_arg_indexes (attrs, "format", indexes, len, delta);
 279       chkp_map_attr_arg_indexes (attrs, "format_arg", indexes, len, delta);
 280       TYPE_ATTRIBUTES (type) = attrs;
 281     }
 282
 283   t = TYPE_MAIN_VARIANT (orig_type);
 284   if (orig_type != t)
 285     {
 286       TYPE_MAIN_VARIANT (type) = t;
 287       TYPE_NEXT_VARIANT (type) = TYPE_NEXT_VARIANT (t);
 288       TYPE_NEXT_VARIANT (t) = type;
 289     }
 290   else
 291     {
 292       TYPE_MAIN_VARIANT (type) = type;
 293       TYPE_NEXT_VARIANT (type) = NULL;
 294     }
 295
 296
 297   return type;
 298 }
 299
 300 /* For given function FNDECL add bounds arguments to arguments
 301    list.  */
 302
 303 static void
 304 chkp_add_bounds_params_to_function (tree fndecl)
 305 {
 306   tree arg;
 307
 308   for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
 309     if (BOUNDED_P (arg))
 310       {
 311         std::string new_name = CHKP_BOUNDS_OF_SYMBOL_PREFIX;
 312         tree new_arg;
 313
 314         if (DECL_NAME (arg))
 315           new_name += IDENTIFIER_POINTER (DECL_NAME (arg));
 316         else
 317           {
 318             char uid[25];
 319             snprintf (uid, 25, "D.%u", DECL_UID (arg));
 320             new_name += uid;
 321           }
 322
 323         new_arg = build_decl (DECL_SOURCE_LOCATION (arg), PARM_DECL,
 324                               get_identifier (new_name.c_str ()),
 325                               pointer_bounds_type_node);
 326         DECL_ARG_TYPE (new_arg) = pointer_bounds_type_node;
 327         DECL_CONTEXT (new_arg) = DECL_CONTEXT (arg);
 328         DECL_ARTIFICIAL (new_arg) = 1;
 329         DECL_CHAIN (new_arg) = DECL_CHAIN (arg);
 330         DECL_CHAIN (arg) = new_arg;
 331
 332         arg = DECL_CHAIN (arg);
 333
 334       }
 335     else if (chkp_type_has_pointer (TREE_TYPE (arg)))
 336       {
 337         tree orig_arg = arg;
 338         bitmap slots = BITMAP_ALLOC (NULL);
 339         bitmap_iterator bi;
 340         unsigned bnd_no;
 341
 342         chkp_find_bound_slots (TREE_TYPE (arg), slots);
 343
 344         EXECUTE_IF_SET_IN_BITMAP (slots, 0, bnd_no, bi)
 345           {
 346             std::string new_name = CHKP_BOUNDS_OF_SYMBOL_PREFIX;
 347             tree new_arg;
 348             char offs[25];
 349
 350             if (DECL_NAME (orig_arg))
 351               new_name += IDENTIFIER_POINTER (DECL_NAME (orig_arg));
 352             else
 353               {
 354                 snprintf (offs, 25, "D.%u", DECL_UID (arg));
 355                 new_name += offs;
 356               }
 357             snprintf (offs, 25, "__%u", bnd_no * POINTER_SIZE / BITS_PER_UNIT);
 358
 359             new_arg = build_decl (DECL_SOURCE_LOCATION (orig_arg),
 360                                   PARM_DECL,
 361                                   get_identifier (new_name.c_str ()),
 362                                   pointer_bounds_type_node);
 363             DECL_ARG_TYPE (new_arg) = pointer_bounds_type_node;
 364             DECL_CONTEXT (new_arg) = DECL_CONTEXT (orig_arg);
 365             DECL_ARTIFICIAL (new_arg) = 1;
 366             DECL_CHAIN (new_arg) = DECL_CHAIN (arg);
 367             DECL_CHAIN (arg) = new_arg;
 368
 369             arg = DECL_CHAIN (arg);
 370           }
 371         BITMAP_FREE (slots);
 372       }
 373
 374   TREE_TYPE (fndecl) =
 375     chkp_copy_function_type_adding_bounds (TREE_TYPE (fndecl));
 376 }
 377
 378 /* Return an instrumentation clone for builtin function
 379    FNDECL.  Create one if needed.  */
 380
 381 tree
 382 chkp_maybe_clone_builtin_fndecl (tree fndecl)
 383 {
 384   tree clone;
 385   enum built_in_function fcode = DECL_FUNCTION_CODE (fndecl);
 386
 387   gcc_assert (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
 388               && fcode < BEGIN_CHKP_BUILTINS);
 389
 390   fcode = (enum built_in_function) (fcode + BEGIN_CHKP_BUILTINS + 1);
 391   clone = builtin_decl_explicit (fcode);
 392   if (clone)
 393     return clone;
 394
 395   clone = chkp_build_instrumented_fndecl (fndecl);
 396   chkp_add_bounds_params_to_function (clone);
 397
 398   gcc_assert (DECL_FUNCTION_CODE (clone) == fcode);
 399
 400   set_builtin_decl (fcode, clone, false);
 401
 402   return clone;
 403 }
 404
 405 /* Return 1 if function FNDECL should be instrumented.  */
 406
 407 bool
 408 chkp_instrumentable_p (tree fndecl)
 409 {
 410   struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
 411   return (!lookup_attribute ("bnd_legacy", DECL_ATTRIBUTES (fndecl))
 412           && (!flag_chkp_instrument_marked_only
 413               || lookup_attribute ("bnd_instrument", DECL_ATTRIBUTES (fndecl)))
 414           && (!fn || !copy_forbidden (fn, fndecl)));
 415 }
 416
 417 /* Return clone created for instrumentation of NODE or NULL.  */
 418
 419 cgraph_node *
 420 chkp_maybe_create_clone (tree fndecl)
 421 {
 422   cgraph_node *node = cgraph_node::get_create (fndecl);
 423   cgraph_node *clone = node->instrumented_version;
 424
 425   gcc_assert (!node->instrumentation_clone);
 426
 427   if (DECL_BUILT_IN (fndecl)
 428       && (DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL
 429           || DECL_FUNCTION_CODE (fndecl) >= BEGIN_CHKP_BUILTINS))
 430     return NULL;
 431
 432   clone = node->instrumented_version;
 433
 434   /* Some instrumented builtin function calls may be optimized and
 435      cgraph nodes may be removed as unreachable.  Later optimizations
 436      may generate new calls to removed functions and in this case
 437      we have to recreate cgraph node.  FUNCTION_DECL for instrumented
 438      builtin still exists and should be reused in such case.  */
 439   if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
 440       && fndecl == builtin_decl_explicit (DECL_FUNCTION_CODE (fndecl))
 441       && !clone)
 442     {
 443       enum built_in_function fncode = DECL_FUNCTION_CODE (fndecl);
 444       tree new_decl;
 445
 446       fncode = (enum built_in_function) (fncode + BEGIN_CHKP_BUILTINS + 1);
 447       new_decl = builtin_decl_explicit (fncode);
 448
 449       /* We've actually already created an instrumented clone once.
 450          Restore it.  */
 451       if (new_decl)
 452         {
 453           clone = cgraph_node::get (new_decl);
 454
 455           if (!clone)
 456             {
 457               gcc_assert (!gimple_has_body_p (fndecl));
 458               clone = cgraph_node::get_create (new_decl);
 459               clone->externally_visible = node->externally_visible;
 460               clone->local = node->local;
 461               clone->address_taken = node->address_taken;
 462               clone->thunk = node->thunk;
 463               clone->alias = node->alias;
 464               clone->weakref = node->weakref;
 465               clone->cpp_implicit_alias = node->cpp_implicit_alias;
 466               clone->orig_decl = fndecl;
 467               clone->instrumentation_clone = true;
 468             }
 469
 470           clone->instrumented_version = node;
 471           node->instrumented_version = clone;
 472         }
 473     }
 474
 475   if (!clone)
 476     {
 477       tree new_decl = chkp_build_instrumented_fndecl (fndecl);
 478       struct cgraph_edge *e;
 479       struct ipa_ref *ref;
 480       int i;
 481
 482       clone = node->create_version_clone (new_decl, vNULL, NULL);
 483       clone->externally_visible = node->externally_visible;
 484       clone->local = node->local;
 485       clone->address_taken = node->address_taken;
 486       clone->thunk = node->thunk;
 487       clone->alias = node->alias;
 488       clone->weakref = node->weakref;
 489       clone->cpp_implicit_alias = node->cpp_implicit_alias;
 490       clone->instrumented_version = node;
 491       clone->orig_decl = fndecl;
 492       clone->instrumentation_clone = true;
 493       node->instrumented_version = clone;
 494
 495       if (gimple_has_body_p (fndecl))
 496         {
 497           /* If function will not be instrumented, then it's instrumented
 498              version is a thunk for the original.  */
 499           if (!chkp_instrumentable_p (fndecl))
 500             {
 501               clone->remove_callees ();
 502               clone->remove_all_references ();
 503               clone->thunk.thunk_p = true;
 504               clone->thunk.add_pointer_bounds_args = true;
 505               clone->create_edge (node, NULL, 0, CGRAPH_FREQ_BASE);
 506             }
 507           else
 508             {
 509               tree_function_versioning (fndecl, new_decl, NULL, false,
 510                                         NULL, false, NULL, NULL);
 511               clone->lowered = true;
 512             }
 513         }
 514
 515       /* New params are inserted after versioning because it
 516          actually copies args list from the original decl.  */
 517       chkp_add_bounds_params_to_function (new_decl);
 518
 519       /* Remember builtin fndecl.  */
 520       if (DECL_BUILT_IN_CLASS (clone->decl) == BUILT_IN_NORMAL
 521           && fndecl == builtin_decl_explicit (DECL_FUNCTION_CODE (fndecl)))
 522         {
 523           gcc_assert (!builtin_decl_explicit (DECL_FUNCTION_CODE (clone->decl)));
 524           set_builtin_decl (DECL_FUNCTION_CODE (clone->decl),
 525                             clone->decl, false);
 526         }
 527
 528       /* Clones have the same comdat group as originals.  */
 529       if (node->same_comdat_group
 530           || DECL_ONE_ONLY (node->decl))
 531         clone->add_to_same_comdat_group (node);
 532
 533       if (gimple_has_body_p (fndecl))
 534         symtab->call_cgraph_insertion_hooks (clone);
 535
 536       /* Clone all aliases.  */
 537       for (i = 0; node->iterate_referring (i, ref); i++)
 538         if (ref->use == IPA_REF_ALIAS)
 539           {
 540             struct cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
 541             struct cgraph_node *chkp_alias
 542               = chkp_maybe_create_clone (alias->decl);
 543             chkp_alias->create_reference (clone, IPA_REF_ALIAS, NULL);
 544           }
 545
 546       /* Clone all thunks.  */
 547       for (e = node->callers; e; e = e->next_caller)
 548         if (e->caller->thunk.thunk_p
 549             && !e->caller->thunk.add_pointer_bounds_args)
 550           {
 551             struct cgraph_node *thunk
 552               = chkp_maybe_create_clone (e->caller->decl);
 553             /* Redirect thunk clone edge to the node clone.  */
 554             thunk->callees->redirect_callee (clone);
 555           }
 556
 557       /* For aliases and thunks we should make sure target is cloned
 558          to have proper references and edges.  */
 559       if (node->thunk.thunk_p)
 560         chkp_maybe_create_clone (node->callees->callee->decl);
 561       else if (node->alias)
 562         {
 563           struct cgraph_node *target;
 564
 565           ref = node->ref_list.first_reference ();
 566           if (ref)
 567             chkp_maybe_create_clone (ref->referred->decl);
 568
 569           if (node->alias_target)
 570             {
 571               if (TREE_CODE (node->alias_target) == FUNCTION_DECL)
 572                 {
 573                   target = chkp_maybe_create_clone (node->alias_target);
 574                   clone->alias_target = target->decl;
 575                 }
 576               else
 577                 clone->alias_target = node->alias_target;
 578             }
 579         }
 580
 581       /* Add IPA reference.  It's main role is to keep instrumented
 582          version reachable while original node is reachable.  */
 583       ref = node->create_reference (clone, IPA_REF_CHKP, NULL);
 584     }
 585
 586   return clone;
 587 }
 588
 589 /* Create clone for all functions to be instrumented.  */
 590
 591 static unsigned int
 592 chkp_versioning (void)
 593 {
 594   struct cgraph_node *node;
 595   const char *reason;
 596
 597   bitmap_obstack_initialize (NULL);
 598
 599   FOR_EACH_DEFINED_FUNCTION (node)
 600     {
 601       if (!node->instrumentation_clone
 602           && !node->instrumented_version
 603           && !node->alias
 604           && !node->thunk.thunk_p
 605           && (!DECL_BUILT_IN (node->decl)
 606               || (DECL_BUILT_IN_CLASS (node->decl) == BUILT_IN_NORMAL
 607                   && DECL_FUNCTION_CODE (node->decl) < BEGIN_CHKP_BUILTINS)))
 608         {
 609           if (chkp_instrumentable_p (node->decl))
 610             chkp_maybe_create_clone (node->decl);
 611           else if ((reason = copy_forbidden (DECL_STRUCT_FUNCTION (node->decl),
 612                                              node->decl)))
 613             {
 614               if (warning_at (DECL_SOURCE_LOCATION (node->decl), OPT_Wchkp,
 615                               "function cannot be instrumented"))
 616                 inform (DECL_SOURCE_LOCATION (node->decl), reason, node->decl);
 617             }
 618         }
 619     }
 620
 621   /* Mark all aliases and thunks of functions with no instrumented
 622      version as legacy function.  */
 623   FOR_EACH_DEFINED_FUNCTION (node)
 624     {
 625       if (!node->instrumentation_clone
 626           && !node->instrumented_version
 627           && (node->alias || node->thunk.thunk_p)
 628           && !lookup_attribute ("bnd_legacy", DECL_ATTRIBUTES (node->decl)))
 629         DECL_ATTRIBUTES (node->decl)
 630           = tree_cons (get_identifier ("bnd_legacy"), NULL,
 631                        DECL_ATTRIBUTES (node->decl));
 632     }
 633
 634   bitmap_obstack_release (NULL);
 635
 636   return 0;
 637 }
 638
 639 /* In this pass we remove bodies of functions having
 640    instrumented version.  Functions with removed bodies
 641    become a special kind of thunks to provide a connection
 642    between calls to the original version and instrumented
 643    function.  */
 644
 645 static unsigned int
 646 chkp_produce_thunks (bool early)
 647 {
 648   struct cgraph_node *node;
 649
 650   FOR_EACH_DEFINED_FUNCTION (node)
 651     {
 652       if (!node->instrumentation_clone
 653           && node->instrumented_version
 654           && gimple_has_body_p (node->decl)
 655           && gimple_has_body_p (node->instrumented_version->decl)
 656           && (!lookup_attribute ("always_inline", DECL_ATTRIBUTES (node->decl))
 657               || !early))
 658         {
 659           node->release_body ();
 660           node->remove_callees ();
 661           node->remove_all_references ();
 662
 663           node->thunk.thunk_p = true;
 664           node->thunk.add_pointer_bounds_args = true;
 665           node->create_edge (node->instrumented_version, NULL,
 666                              0, CGRAPH_FREQ_BASE);
 667           node->create_reference (node->instrumented_version,
 668                                IPA_REF_CHKP, NULL);
 669         }
 670     }
 671
 672   /* Mark instrumentation clones created for aliases and thunks
 673      as insttrumented so they could be removed as unreachable
 674      now.  */
 675   if (!early)
 676     {
 677       FOR_EACH_DEFINED_FUNCTION (node)
 678       {
 679         if (node->instrumentation_clone
 680             && (node->alias || node->thunk.thunk_p)
 681             && !chkp_function_instrumented_p (node->decl))
 682           chkp_function_mark_instrumented (node->decl);
 683       }
 684     }
 685
 686   return TODO_remove_functions;
 687 }
 688
 689 const pass_data pass_data_ipa_chkp_versioning =
 690 {
 691   SIMPLE_IPA_PASS, /* type */
 692   "chkp_versioning", /* name */
 693   OPTGROUP_NONE, /* optinfo_flags */
 694   TV_NONE, /* tv_id */
 695   0, /* properties_required */
 696   0, /* properties_provided */
 697   0, /* properties_destroyed */
 698   0, /* todo_flags_start */
 699   0 /* todo_flags_finish */
 700 };
 701
 702 const pass_data pass_data_ipa_chkp_early_produce_thunks =
 703 {
 704   SIMPLE_IPA_PASS, /* type */
 705   "chkp_ecleanup", /* name */
 706   OPTGROUP_NONE, /* optinfo_flags */
 707   TV_NONE, /* tv_id */
 708   0, /* properties_required */
 709   0, /* properties_provided */
 710   0, /* properties_destroyed */
 711   0, /* todo_flags_start */
 712   0 /* todo_flags_finish */
 713 };
 714
 715 const pass_data pass_data_ipa_chkp_produce_thunks =
 716 {
 717   SIMPLE_IPA_PASS, /* type */
 718   "chkp_cleanup", /* name */
 719   OPTGROUP_NONE, /* optinfo_flags */
 720   TV_NONE, /* tv_id */
 721   0, /* properties_required */
 722   0, /* properties_provided */
 723   0, /* properties_destroyed */
 724   0, /* todo_flags_start */
 725   0 /* todo_flags_finish */
 726 };
 727
 728 class pass_ipa_chkp_versioning : public simple_ipa_opt_pass
 729 {
 730 public:
 731   pass_ipa_chkp_versioning (gcc::context *ctxt)
 732     : simple_ipa_opt_pass (pass_data_ipa_chkp_versioning, ctxt)
 733   {}
 734
 735   /* opt_pass methods: */
 736   virtual opt_pass * clone ()
 737     {
 738       return new pass_ipa_chkp_versioning (m_ctxt);
 739     }
 740
 741   virtual bool gate (function *)
 742     {
 743       return flag_check_pointer_bounds;
 744     }
 745
 746   virtual unsigned int execute (function *)
 747     {
 748       return chkp_versioning ();
 749     }
 750
 751 }; // class pass_ipa_chkp_versioning
 752
 753 class pass_ipa_chkp_early_produce_thunks : public simple_ipa_opt_pass
 754 {
 755 public:
 756   pass_ipa_chkp_early_produce_thunks (gcc::context *ctxt)
 757     : simple_ipa_opt_pass (pass_data_ipa_chkp_early_produce_thunks, ctxt)
 758   {}
 759
 760   /* opt_pass methods: */
 761   virtual opt_pass * clone ()
 762     {
 763       return new pass_ipa_chkp_early_produce_thunks (m_ctxt);
 764     }
 765
 766   virtual bool gate (function *)
 767     {
 768       return flag_check_pointer_bounds;
 769     }
 770
 771   virtual unsigned int execute (function *)
 772     {
 773       return chkp_produce_thunks (true);
 774     }
 775
 776 }; // class pass_chkp_produce_thunks
 777
 778 class pass_ipa_chkp_produce_thunks : public simple_ipa_opt_pass
 779 {
 780 public:
 781   pass_ipa_chkp_produce_thunks (gcc::context *ctxt)
 782     : simple_ipa_opt_pass (pass_data_ipa_chkp_produce_thunks, ctxt)
 783   {}
 784
 785   /* opt_pass methods: */
 786   virtual opt_pass * clone ()
 787     {
 788       return new pass_ipa_chkp_produce_thunks (m_ctxt);
 789     }
 790
 791   virtual bool gate (function *)
 792     {
 793       return flag_check_pointer_bounds;
 794     }
 795
 796   virtual unsigned int execute (function *)
 797     {
 798       return chkp_produce_thunks (false);
 799     }
 800
 801 }; // class pass_chkp_produce_thunks
 802
 803 simple_ipa_opt_pass *
 804 make_pass_ipa_chkp_versioning (gcc::context *ctxt)
 805 {
 806   return new pass_ipa_chkp_versioning (ctxt);
 807 }
 808
 809 simple_ipa_opt_pass *
 810 make_pass_ipa_chkp_early_produce_thunks (gcc::context *ctxt)
 811 {
 812   return new pass_ipa_chkp_early_produce_thunks (ctxt);
 813 }
 814
 815 simple_ipa_opt_pass *
 816 make_pass_ipa_chkp_produce_thunks (gcc::context *ctxt)
 817 {
 818   return new pass_ipa_chkp_produce_thunks (ctxt);
 819 }