gcc/sancov.c

   1 /* Code coverage instrumentation for fuzzing.
   2    Copyright (C) 2015-2017 Free Software Foundation, Inc.
   3    Contributed by Dmitry Vyukov <dvyukov@google.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 "backend.h"
  25 #include "tree.h"
  26 #include "gimple.h"
  27 #include "basic-block.h"
  28 #include "options.h"
  29 #include "flags.h"
  30 #include "stmt.h"
  31 #include "gimple-iterator.h"
  32 #include "tree-cfg.h"
  33 #include "tree-pass.h"
  34 #include "tree-iterator.h"
  35 #include "asan.h"
  36
  37 namespace {
  38
  39 unsigned
  40 sancov_pass (function *fun)
  41 {
  42   initialize_sanitizer_builtins ();
  43
  44   /* Insert callback into beginning of every BB. */
  45   tree fndecl = builtin_decl_implicit (BUILT_IN_SANITIZER_COV_TRACE_PC);
  46   basic_block bb;
  47   FOR_EACH_BB_FN (bb, fun)
  48     {
  49       gimple_stmt_iterator gsi = gsi_after_labels (bb);
  50       if (gsi_end_p (gsi))
  51         continue;
  52       gimple *stmt = gsi_stmt (gsi);
  53       gimple *gcall = gimple_build_call (fndecl, 0);
  54       gimple_set_location (gcall, gimple_location (stmt));
  55       gsi_insert_before (&gsi, gcall, GSI_SAME_STMT);
  56     }
  57   return 0;
  58 }
  59
  60 template <bool O0> class pass_sancov : public gimple_opt_pass
  61 {
  62 public:
  63   pass_sancov (gcc::context *ctxt) : gimple_opt_pass (data, ctxt) {}
  64
  65   static const pass_data data;
  66   opt_pass *
  67   clone ()
  68   {
  69     return new pass_sancov<O0> (m_ctxt);
  70   }
  71   virtual bool
  72   gate (function *)
  73   {
  74     return flag_sanitize_coverage && (!O0 || !optimize);
  75   }
  76   virtual unsigned int
  77   execute (function *fun)
  78   {
  79     return sancov_pass (fun);
  80   }
  81 }; // class pass_sancov
  82
  83 template <bool O0>
  84 const pass_data pass_sancov<O0>::data = {
  85   GIMPLE_PASS,                 /* type */
  86   O0 ? "sancov_O0" : "sancov", /* name */
  87   OPTGROUP_NONE,               /* optinfo_flags */
  88   TV_NONE,                     /* tv_id */
  89   (PROP_cfg),                  /* properties_required */
  90   0,                           /* properties_provided */
  91   0,                           /* properties_destroyed */
  92   0,                           /* todo_flags_start */
  93   TODO_update_ssa,           /* todo_flags_finish */
  94 };
  95
  96 } // anon namespace
  97
  98 gimple_opt_pass *
  99 make_pass_sancov (gcc::context *ctxt)
 100 {
 101   return new pass_sancov<false> (ctxt);
 102 }
 103
 104 gimple_opt_pass *
 105 make_pass_sancov_O0 (gcc::context *ctxt)
 106 {
 107   return new pass_sancov<true> (ctxt);
 108 }