/* A state machine for detecting misuses of the malloc/free API.
Copyright (C) 2019-2020 Free Software Foundation, Inc.
Contributed by David Malcolm <dmalcolm@redhat.com>.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "function.h"
#include "basic-block.h"
#include "gimple.h"
#include "options.h"
#include "bitmap.h"
#include "diagnostic-path.h"
#include "diagnostic-metadata.h"
#include "function.h"
#include "analyzer/analyzer.h"
#include "diagnostic-event-id.h"
#include "analyzer/analyzer-logging.h"
#include "analyzer/sm.h"
#include "analyzer/pending-diagnostic.h"
#if ENABLE_ANALYZER
namespace ana {
namespace {
/* A state machine for detecting misuses of the malloc/free API.
See sm-malloc.dot for an overview (keep this in-sync with that file). */
class malloc_state_machine : public state_machine
{
public:
malloc_state_machine (logger *logger);
bool inherited_state_p () const FINAL OVERRIDE { return false; }
bool on_stmt (sm_context *sm_ctxt,
const supernode *node,
const gimple *stmt) const FINAL OVERRIDE;
void on_phi (sm_context *sm_ctxt,
const supernode *node,
const gphi *phi,
tree rhs) const FINAL OVERRIDE;
void on_condition (sm_context *sm_ctxt,
const supernode *node,
const gimple *stmt,
tree lhs,
enum tree_code op,
tree rhs) const FINAL OVERRIDE;
bool can_purge_p (state_t s) const FINAL OVERRIDE;
pending_diagnostic *on_leak (tree var) const FINAL OVERRIDE;
/* Start state. */
state_t m_start;
/* State for a pointer returned from malloc that hasn't been checked for
NULL.
It could be a pointer to heap-allocated memory, or could be NULL. */
state_t m_unchecked;
/* State for a pointer that's known to be NULL. */
state_t m_null;
/* State for a pointer to heap-allocated memory, known to be non-NULL. */
state_t m_nonnull;
/* State for a pointer to freed memory. */
state_t m_freed;
/* State for a pointer that's known to not be on the heap (e.g. to a local
or global). */
state_t m_non_heap; // TODO: or should this be a different state machine?
// or do we need child values etc?
/* Stop state, for pointers we don't want to track any more. */
state_t m_stop;
private:
void on_zero_assignment (sm_context *sm_ctxt,
const supernode *node,
const gimple *stmt,
tree lhs) const;
};
/* Class for diagnostics relating to malloc_state_machine. */
class malloc_diagnostic : public pending_diagnostic
{
public:
malloc_diagnostic (const malloc_state_machine &sm, tree arg)
: m_sm (sm), m_arg (arg)
{}
bool subclass_equal_p (const pending_diagnostic &base_other) const OVERRIDE
{
return same_tree_p (m_arg, ((const malloc_diagnostic &)base_other).m_arg);
}
label_text describe_state_change (const evdesc::state_change &change)
OVERRIDE
{
if (change.m_old_state == m_sm.m_start
&& change.m_new_state == m_sm.m_unchecked)
// TODO: verify that it's the allocation stmt, not a copy
return label_text::borrow ("allocated here");
if (change.m_old_state == m_sm.m_unchecked
&& change.m_new_state == m_sm.m_nonnull)
return change.formatted_print ("assuming %qE is non-NULL",
change.m_expr);
if (change.m_new_state == m_sm.m_null)
{
if (change.m_old_state == m_sm.m_unchecked)
return change.formatted_print ("assuming %qE is NULL",
change.m_expr);
else
return change.formatted_print ("%qE is NULL",
change.m_expr);
}
return label_text ();
}
protected:
const malloc_state_machine &m_sm;
tree m_arg;
};
/* Concrete subclass for reporting double-free diagnostics. */
class double_free : public malloc_diagnostic
{
public:
double_free (const malloc_state_machine &sm, tree arg)
: malloc_diagnostic (sm, arg)
{}
const char *get_kind () const FINAL OVERRIDE { return "double_free"; }
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
auto_diagnostic_group d;
diagnostic_metadata m;
m.add_cwe (415); /* CWE-415: Double Free. */
return warning_meta (rich_loc, m, OPT_Wanalyzer_double_free,
"double-%<free%> of %qE", m_arg);
}
label_text describe_state_change (const evdesc::state_change &change)
FINAL OVERRIDE
{
if (change.m_new_state == m_sm.m_freed)
{
m_first_free_event = change.m_event_id;
return change.formatted_print ("first %qs here", "free");
}
return malloc_diagnostic::describe_state_change (change);
}
label_text describe_call_with_state (const evdesc::call_with_state &info)
FINAL OVERRIDE
{
if (info.m_state == m_sm.m_freed)
return info.formatted_print
("passing freed pointer %qE in call to %qE from %qE",
info.m_expr, info.m_callee_fndecl, info.m_caller_fndecl);
return label_text ();
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
if (m_first_free_event.known_p ())
return ev.formatted_print ("second %qs here; first %qs was at %@",
"free", "free",
&m_first_free_event);
return ev.formatted_print ("second %qs here", "free");
}
private:
diagnostic_event_id_t m_first_free_event;
};
/* Abstract subclass for describing possible bad uses of NULL.
Responsible for describing the call that could return NULL. */
class possible_null : public malloc_diagnostic
{
public:
possible_null (const malloc_state_machine &sm, tree arg)
: malloc_diagnostic (sm, arg)
{}
label_text describe_state_change (const evdesc::state_change &change)
FINAL OVERRIDE
{
if (change.m_old_state == m_sm.m_start
&& change.m_new_state == m_sm.m_unchecked)
{
m_origin_of_unchecked_event = change.m_event_id;
return label_text::borrow ("this call could return NULL");
}
return malloc_diagnostic::describe_state_change (change);
}
label_text describe_return_of_state (const evdesc::return_of_state &info)
FINAL OVERRIDE
{
if (info.m_state == m_sm.m_unchecked)
return info.formatted_print ("possible return of NULL to %qE from %qE",
info.m_caller_fndecl, info.m_callee_fndecl);
return label_text ();
}
protected:
diagnostic_event_id_t m_origin_of_unchecked_event;
};
/* Concrete subclass for describing dereference of a possible NULL
value. */
class possible_null_deref : public possible_null
{
public:
possible_null_deref (const malloc_state_machine &sm, tree arg)
: possible_null (sm, arg)
{}
const char *get_kind () const FINAL OVERRIDE { return "possible_null_deref"; }
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
/* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */
diagnostic_metadata m;
m.add_cwe (690);
return warning_meta (rich_loc, m,
OPT_Wanalyzer_possible_null_dereference,
"dereference of possibly-NULL %qE", m_arg);
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
if (m_origin_of_unchecked_event.known_p ())
return ev.formatted_print ("%qE could be NULL: unchecked value from %@",
ev.m_expr,
&m_origin_of_unchecked_event);
else
return ev.formatted_print ("%qE could be NULL", ev.m_expr);
}
};
/* Subroutine for use by possible_null_arg::emit and null_arg::emit.
Issue a note informing that the pertinent argument must be non-NULL. */
static void
inform_nonnull_attribute (tree fndecl, int arg_idx)
{
inform (DECL_SOURCE_LOCATION (fndecl),
"argument %u of %qD must be non-null",
arg_idx + 1, fndecl);
/* Ideally we would use the location of the parm and underline the
attribute also - but we don't have the location_t values at this point
in the middle-end.
For reference, the C and C++ FEs have get_fndecl_argument_location. */
}
/* Concrete subclass for describing passing a possibly-NULL value to a
function marked with __attribute__((nonnull)). */
class possible_null_arg : public possible_null
{
public:
possible_null_arg (const malloc_state_machine &sm, tree arg,
tree fndecl, int arg_idx)
: possible_null (sm, arg),
m_fndecl (fndecl), m_arg_idx (arg_idx)
{}
const char *get_kind () const FINAL OVERRIDE { return "possible_null_arg"; }
bool subclass_equal_p (const pending_diagnostic &base_other) const
{
const possible_null_arg &sub_other
= (const possible_null_arg &)base_other;
return (same_tree_p (m_arg, sub_other.m_arg)
&& m_fndecl == sub_other.m_fndecl
&& m_arg_idx == sub_other.m_arg_idx);
}
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
/* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */
auto_diagnostic_group d;
diagnostic_metadata m;
m.add_cwe (690);
bool warned
= warning_meta (rich_loc, m, OPT_Wanalyzer_possible_null_argument,
"use of possibly-NULL %qE where non-null expected",
m_arg);
if (warned)
inform_nonnull_attribute (m_fndecl, m_arg_idx);
return warned;
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
if (m_origin_of_unchecked_event.known_p ())
return ev.formatted_print ("argument %u (%qE) from %@ could be NULL"
" where non-null expected",
m_arg_idx + 1, ev.m_expr,
&m_origin_of_unchecked_event);
else
return ev.formatted_print ("argument %u (%qE) could be NULL"
" where non-null expected",
m_arg_idx + 1, ev.m_expr);
}
private:
tree m_fndecl;
int m_arg_idx;
};
/* Concrete subclass for describing a dereference of a NULL value. */
class null_deref : public malloc_diagnostic
{
public:
null_deref (const malloc_state_machine &sm, tree arg)
: malloc_diagnostic (sm, arg) {}
const char *get_kind () const FINAL OVERRIDE { return "null_deref"; }
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
/* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */
diagnostic_metadata m;
m.add_cwe (690);
return warning_meta (rich_loc, m,
OPT_Wanalyzer_null_dereference,
"dereference of NULL %qE", m_arg);
}
label_text describe_return_of_state (const evdesc::return_of_state &info)
FINAL OVERRIDE
{
if (info.m_state == m_sm.m_null)
return info.formatted_print ("return of NULL to %qE from %qE",
info.m_caller_fndecl, info.m_callee_fndecl);
return label_text ();
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
return ev.formatted_print ("dereference of NULL %qE", ev.m_expr);
}
};
/* Concrete subclass for describing passing a NULL value to a
function marked with __attribute__((nonnull)). */
class null_arg : public malloc_diagnostic
{
public:
null_arg (const malloc_state_machine &sm, tree arg,
tree fndecl, int arg_idx)
: malloc_diagnostic (sm, arg),
m_fndecl (fndecl), m_arg_idx (arg_idx)
{}
const char *get_kind () const FINAL OVERRIDE { return "null_arg"; }
bool subclass_equal_p (const pending_diagnostic &base_other) const
{
const null_arg &sub_other
= (const null_arg &)base_other;
return (same_tree_p (m_arg, sub_other.m_arg)
&& m_fndecl == sub_other.m_fndecl
&& m_arg_idx == sub_other.m_arg_idx);
}
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
/* CWE-690: Unchecked Return Value to NULL Pointer Dereference. */
auto_diagnostic_group d;
diagnostic_metadata m;
m.add_cwe (690);
bool warned = warning_meta (rich_loc, m, OPT_Wanalyzer_null_argument,
"use of NULL %qE where non-null expected",
m_arg);
if (warned)
inform_nonnull_attribute (m_fndecl, m_arg_idx);
return warned;
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
return ev.formatted_print ("argument %u (%qE) NULL"
" where non-null expected",
m_arg_idx + 1, ev.m_expr);
}
private:
tree m_fndecl;
int m_arg_idx;
};
class use_after_free : public malloc_diagnostic
{
public:
use_after_free (const malloc_state_machine &sm, tree arg)
: malloc_diagnostic (sm, arg)
{}
const char *get_kind () const FINAL OVERRIDE { return "use_after_free"; }
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
/* CWE-416: Use After Free. */
diagnostic_metadata m;
m.add_cwe (416);
return warning_meta (rich_loc, m, OPT_Wanalyzer_use_after_free,
"use after %<free%> of %qE", m_arg);
}
label_text describe_state_change (const evdesc::state_change &change)
FINAL OVERRIDE
{
if (change.m_new_state == m_sm.m_freed)
{
m_free_event = change.m_event_id;
return label_text::borrow ("freed here");
}
return malloc_diagnostic::describe_state_change (change);
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
if (m_free_event.known_p ())
return ev.formatted_print ("use after %<free%> of %qE; freed at %@",
ev.m_expr, &m_free_event);
else
return ev.formatted_print ("use after %<free%> of %qE", ev.m_expr);
}
private:
diagnostic_event_id_t m_free_event;
};
class malloc_leak : public malloc_diagnostic
{
public:
malloc_leak (const malloc_state_machine &sm, tree arg)
: malloc_diagnostic (sm, arg) {}
const char *get_kind () const FINAL OVERRIDE { return "malloc_leak"; }
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
diagnostic_metadata m;
m.add_cwe (401);
return warning_meta (rich_loc, m, OPT_Wanalyzer_malloc_leak,
"leak of %qE", m_arg);
}
label_text describe_state_change (const evdesc::state_change &change)
FINAL OVERRIDE
{
if (change.m_new_state == m_sm.m_unchecked)
{
m_malloc_event = change.m_event_id;
return label_text::borrow ("allocated here");
}
return malloc_diagnostic::describe_state_change (change);
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
if (m_malloc_event.known_p ())
return ev.formatted_print ("%qE leaks here; was allocated at %@",
ev.m_expr, &m_malloc_event);
else
return ev.formatted_print ("%qE leaks here", ev.m_expr);
}
private:
diagnostic_event_id_t m_malloc_event;
};
class free_of_non_heap : public malloc_diagnostic
{
public:
free_of_non_heap (const malloc_state_machine &sm, tree arg)
: malloc_diagnostic (sm, arg), m_kind (KIND_UNKNOWN)
{
}
const char *get_kind () const FINAL OVERRIDE { return "free_of_non_heap"; }
bool subclass_equal_p (const pending_diagnostic &base_other) const
FINAL OVERRIDE
{
const free_of_non_heap &other = (const free_of_non_heap &)base_other;
return (same_tree_p (m_arg, other.m_arg) && m_kind == other.m_kind);
}
bool emit (rich_location *rich_loc) FINAL OVERRIDE
{
auto_diagnostic_group d;
diagnostic_metadata m;
m.add_cwe (590); /* CWE-590: Free of Memory not on the Heap. */
switch (m_kind)
{
default:
gcc_unreachable ();
case KIND_UNKNOWN:
return warning_meta (rich_loc, m, OPT_Wanalyzer_free_of_non_heap,
"%<free%> of %qE which points to memory"
" not on the heap",
m_arg);
break;
case KIND_ALLOCA:
return warning_meta (rich_loc, m, OPT_Wanalyzer_free_of_non_heap,
"%<free%> of memory allocated on the stack by"
" %qs (%qE) will corrupt the heap",
"alloca", m_arg);
break;
}
}
label_text describe_state_change (const evdesc::state_change &change)
FINAL OVERRIDE
{
/* Attempt to reconstruct what kind of pointer it is.
(It seems neater for this to be a part of the state, though). */
if (TREE_CODE (change.m_expr) == SSA_NAME)
{
gimple *def_stmt = SSA_NAME_DEF_STMT (change.m_expr);
if (gcall *call = dyn_cast <gcall *> (def_stmt))
{
if (is_special_named_call_p (call, "alloca", 1)
|| is_special_named_call_p (call, "__builtin_alloca", 1))
{
m_kind = KIND_ALLOCA;
return label_text::borrow
("memory is allocated on the stack here");
}
}
}
return label_text::borrow ("pointer is from here");
}
label_text describe_final_event (const evdesc::final_event &ev) FINAL OVERRIDE
{
return ev.formatted_print ("call to %qs here", "free");
}
private:
enum kind
{
KIND_UNKNOWN,
KIND_ALLOCA
};
enum kind m_kind;
};
/* malloc_state_machine's ctor. */
malloc_state_machine::malloc_state_machine (logger *logger)
: state_machine ("malloc", logger)
{
m_start = add_state ("start");
m_unchecked = add_state ("unchecked");
m_null = add_state ("null");
m_nonnull = add_state ("nonnull");
m_freed = add_state ("freed");
m_non_heap = add_state ("non-heap");
m_stop = add_state ("stop");
}
/* Implementation of state_machine::on_stmt vfunc for malloc_state_machine. */
bool
malloc_state_machine::on_stmt (sm_context *sm_ctxt,
const supernode *node,
const gimple *stmt) const
{
if (const gcall *call = dyn_cast <const gcall *> (stmt))
if (tree callee_fndecl = sm_ctxt->get_fndecl_for_call (call))
{
if (is_named_call_p (callee_fndecl, "malloc", call, 1)
|| is_named_call_p (callee_fndecl, "calloc", call, 2)
|| is_std_named_call_p (callee_fndecl, "malloc", call, 1)
|| is_std_named_call_p (callee_fndecl, "calloc", call, 2)
|| is_named_call_p (callee_fndecl, "__builtin_malloc", call, 1)
|| is_named_call_p (callee_fndecl, "__builtin_calloc", call, 2))
{
tree lhs = gimple_call_lhs (call);
if (lhs)
{
lhs = sm_ctxt->get_readable_tree (lhs);
sm_ctxt->on_transition (node, stmt, lhs, m_start, m_unchecked);
}
else
{
/* TODO: report leak. */
}
return true;
}
if (is_named_call_p (callee_fndecl, "alloca", call, 1)
|| is_named_call_p (callee_fndecl, "__builtin_alloca", call, 1))
{
tree lhs = gimple_call_lhs (call);
if (lhs)
{
lhs = sm_ctxt->get_readable_tree (lhs);
sm_ctxt->on_transition (node, stmt, lhs, m_start, m_non_heap);
}
return true;
}
if (is_named_call_p (callee_fndecl, "free", call, 1)
|| is_std_named_call_p (callee_fndecl, "free", call, 1)
|| is_named_call_p (callee_fndecl, "__builtin_free", call, 1))
{
tree arg = gimple_call_arg (call, 0);
arg = sm_ctxt->get_readable_tree (arg);
/* start/unchecked/nonnull -> freed. */
sm_ctxt->on_transition (node, stmt, arg, m_start, m_freed);
sm_ctxt->on_transition (node, stmt, arg, m_unchecked, m_freed);
sm_ctxt->on_transition (node, stmt, arg, m_nonnull, m_freed);
/* Keep state "null" as-is, rather than transitioning to "free";
we don't want to complain about double-free of NULL. */
/* freed -> stop, with warning. */
sm_ctxt->warn_for_state (node, stmt, arg, m_freed,
new double_free (*this, arg));
sm_ctxt->on_transition (node, stmt, arg, m_freed, m_stop);
/* non-heap -> stop, with warning. */
sm_ctxt->warn_for_state (node, stmt, arg, m_non_heap,
new free_of_non_heap (*this, arg));
sm_ctxt->on_transition (node, stmt, arg, m_non_heap, m_stop);
return true;
}
/* Handle "__attribute__((nonnull))". */
{
tree fntype = TREE_TYPE (callee_fndecl);
bitmap nonnull_args = get_nonnull_args (fntype);
if (nonnull_args)
{
for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
{
tree arg = gimple_call_arg (stmt, i);
if (TREE_CODE (TREE_TYPE (arg)) != POINTER_TYPE)
continue;
/* If we have a nonnull-args, and either all pointers, or just
the specified pointers. */
if (bitmap_empty_p (nonnull_args)
|| bitmap_bit_p (nonnull_args, i))
{
sm_ctxt->warn_for_state
(node, stmt, arg, m_unchecked,
new possible_null_arg (*this, arg, callee_fndecl, i));
sm_ctxt->on_transition (node, stmt, arg, m_unchecked,
m_nonnull);
sm_ctxt->warn_for_state
(node, stmt, arg, m_null,
new null_arg (*this, arg, callee_fndecl, i));
sm_ctxt->on_transition (node, stmt, arg, m_null, m_stop);
}
}
BITMAP_FREE (nonnull_args);
}
}
}
if (tree lhs = is_zero_assignment (stmt))
if (any_pointer_p (lhs))
on_zero_assignment (sm_ctxt, node, stmt,lhs);
if (const gassign *assign_stmt = dyn_cast <const gassign *> (stmt))
{
enum tree_code op = gimple_assign_rhs_code (assign_stmt);
if (op == ADDR_EXPR)
{
tree lhs = gimple_assign_lhs (assign_stmt);
if (lhs)
{
lhs = sm_ctxt->get_readable_tree (lhs);
sm_ctxt->on_transition (node, stmt, lhs, m_start, m_non_heap);
}
}
}
/* Handle dereferences. */
for (unsigned i = 0; i < gimple_num_ops (stmt); i++)
{
tree op = gimple_op (stmt, i);
if (!op)
continue;
if (TREE_CODE (op) == COMPONENT_REF)
op = TREE_OPERAND (op, 0);
if (TREE_CODE (op) == MEM_REF)
{
tree arg = TREE_OPERAND (op, 0);
arg = sm_ctxt->get_readable_tree (arg);
sm_ctxt->warn_for_state (node, stmt, arg, m_unchecked,
new possible_null_deref (*this, arg));
sm_ctxt->on_transition (node, stmt, arg, m_unchecked, m_nonnull);
sm_ctxt->warn_for_state (node, stmt, arg, m_null,
new null_deref (*this, arg));
sm_ctxt->on_transition (node, stmt, arg, m_null, m_stop);
sm_ctxt->warn_for_state (node, stmt, arg, m_freed,
new use_after_free (*this, arg));
sm_ctxt->on_transition (node, stmt, arg, m_freed, m_stop);
}
}
return false;
}
/* Implementation of state_machine::on_phi vfunc for malloc_state_machine. */
void
malloc_state_machine::on_phi (sm_context *sm_ctxt,
const supernode *node,
const gphi *phi,
tree rhs) const
{
if (zerop (rhs))
{
tree lhs = gimple_phi_result (phi);
on_zero_assignment (sm_ctxt, node, phi, lhs);
}
}
/* Implementation of state_machine::on_condition vfunc for malloc_state_machine.
Potentially transition state 'unchecked' to 'nonnull' or to 'null'. */
void
malloc_state_machine::on_condition (sm_context *sm_ctxt,
const supernode *node,
const gimple *stmt,
tree lhs,
enum tree_code op,
tree rhs) const
{
if (!zerop (rhs))
return;
if (!any_pointer_p (lhs))
return;
if (!any_pointer_p (rhs))
return;
if (op == NE_EXPR)
{
log ("got 'ARG != 0' match");
sm_ctxt->on_transition (node, stmt,
lhs, m_unchecked, m_nonnull);
}
else if (op == EQ_EXPR)
{
log ("got 'ARG == 0' match");
sm_ctxt->on_transition (node, stmt,
lhs, m_unchecked, m_null);
}
}
/* Implementation of state_machine::can_purge_p vfunc for malloc_state_machine.
Don't allow purging of pointers in state 'unchecked' or 'nonnull'
(to avoid false leak reports). */
bool
malloc_state_machine::can_purge_p (state_t s) const
{
return s != m_unchecked && s != m_nonnull;
}
/* Implementation of state_machine::on_leak vfunc for malloc_state_machine
(for complaining about leaks of pointers in state 'unchecked' and
'nonnull'). */
pending_diagnostic *
malloc_state_machine::on_leak (tree var) const
{
return new malloc_leak (*this, var);
}
/* Shared logic for handling GIMPLE_ASSIGNs and GIMPLE_PHIs that
assign zero to LHS. */
void
malloc_state_machine::on_zero_assignment (sm_context *sm_ctxt,
const supernode *node,
const gimple *stmt,
tree lhs) const
{
sm_ctxt->on_transition (node, stmt, lhs, m_start, m_null);
sm_ctxt->on_transition (node, stmt, lhs, m_unchecked, m_null);
sm_ctxt->on_transition (node, stmt, lhs, m_nonnull, m_null);
sm_ctxt->on_transition (node, stmt, lhs, m_freed, m_null);
}
} // anonymous namespace
/* Internal interface to this file. */
state_machine *
make_malloc_state_machine (logger *logger)
{
return new malloc_state_machine (logger);
}
} // namespace ana
#endif /* #if ENABLE_ANALYZER */