gcc/analyzer/sm.cc

   1 /* Modeling API uses and misuses via state machines.
   2    Copyright (C) 2019-2020 Free Software Foundation, Inc.
   3    Contributed by David Malcolm <dmalcolm@redhat.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 General Public License 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 "tree.h"
  25 #include "function.h"
  26 #include "basic-block.h"
  27 #include "gimple.h"
  28 #include "options.h"
  29 #include "function.h"
  30 #include "diagnostic-core.h"
  31 #include "analyzer/analyzer.h"
  32 #include "analyzer/analyzer-logging.h"
  33 #include "analyzer/sm.h"
  34
  35 #if ENABLE_ANALYZER
  36
  37 /* If STMT is an assignment from zero, return the LHS.  */
  38
  39 tree
  40 is_zero_assignment (const gimple *stmt)
  41 {
  42   const gassign *assign_stmt = dyn_cast <const gassign *> (stmt);
  43   if (!assign_stmt)
  44     return NULL_TREE;
  45
  46   enum tree_code op = gimple_assign_rhs_code (assign_stmt);
  47   if (TREE_CODE_CLASS (op) != tcc_constant)
  48     return NULL_TREE;
  49
  50   if (!zerop (gimple_assign_rhs1 (assign_stmt)))
  51     return NULL_TREE;
  52
  53   return gimple_assign_lhs (assign_stmt);
  54 }
  55
  56 /* Return true if VAR has pointer or reference type.  */
  57
  58 bool
  59 any_pointer_p (tree var)
  60 {
  61   return POINTER_TYPE_P (TREE_TYPE (var));
  62 }
  63
  64 /* Add a state with name NAME to this state_machine.
  65    The string is required to outlive the state_machine.
  66
  67    Return the state_t for the new state.  */
  68
  69 state_machine::state_t
  70 state_machine::add_state (const char *name)
  71 {
  72   m_state_names.safe_push (name);
  73   return m_state_names.length () - 1;
  74 }
  75
  76 /* Get the name of state S within this state_machine.  */
  77
  78 const char *
  79 state_machine::get_state_name (state_t s) const
  80 {
  81   return m_state_names[s];
  82 }
  83
  84 /* Assert that S is a valid state for this state_machine.  */
  85
  86 void
  87 state_machine::validate (state_t s) const
  88 {
  89   gcc_assert (s < m_state_names.length ());
  90 }
  91
  92 /* Create instances of the various state machines, each using LOGGER,
  93    and populate OUT with them.  */
  94
  95 void
  96 make_checkers (auto_delete_vec <state_machine> &out, logger *logger)
  97 {
  98   out.safe_push (make_malloc_state_machine (logger));
  99   out.safe_push (make_fileptr_state_machine (logger));
 100   out.safe_push (make_taint_state_machine (logger));
 101   out.safe_push (make_sensitive_state_machine (logger));
 102   out.safe_push (make_signal_state_machine (logger));
 103
 104   /* We only attempt to run the pattern tests if it might have been manually
 105      enabled (for DejaGnu purposes).  */
 106   if (flag_analyzer_checker)
 107     out.safe_push (make_pattern_test_state_machine (logger));
 108
 109   if (flag_analyzer_checker)
 110     {
 111       unsigned read_index, write_index;
 112       state_machine **sm;
 113
 114       /* TODO: this leaks the machines
 115          Would be nice to log the things that were removed.  */
 116       VEC_ORDERED_REMOVE_IF (out, read_index, write_index, sm,
 117                              0 != strcmp (flag_analyzer_checker,
 118                                           (*sm)->get_name ()));
 119     }
 120 }
 121
 122 #endif /* #if ENABLE_ANALYZER */