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/* -Wnonnull-compare warning support.
Copyright (C) 2016-2017 Free Software Foundation, Inc.
Contributed by Jakub Jelinek <jakub@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 "backend.h"
#include "tree.h"
#include "gimple.h"
#include "tree-pass.h"
#include "ssa.h"
#include "diagnostic-core.h"
#include "tree-dfa.h"
/* Warn about comparison of nonnull_arg_p argument initial values
with NULL. */
static void
do_warn_nonnull_compare (function *fun, tree arg)
{
if (!POINTER_TYPE_P (TREE_TYPE (arg))
&& TREE_CODE (TREE_TYPE (arg)) != OFFSET_TYPE)
return;
if (!nonnull_arg_p (arg))
return;
tree d = ssa_default_def (fun, arg);
if (d == NULL_TREE)
return;
use_operand_p use_p;
imm_use_iterator iter;
FOR_EACH_IMM_USE_FAST (use_p, iter, d)
{
gimple *stmt = USE_STMT (use_p);
tree op = NULL_TREE;
location_t loc = gimple_location (stmt);
if (gimple_code (stmt) == GIMPLE_COND)
switch (gimple_cond_code (stmt))
{
case EQ_EXPR:
case NE_EXPR:
if (gimple_cond_lhs (stmt) == d)
op = gimple_cond_rhs (stmt);
break;
default:
break;
}
else if (is_gimple_assign (stmt))
switch (gimple_assign_rhs_code (stmt))
{
case EQ_EXPR:
case NE_EXPR:
if (gimple_assign_rhs1 (stmt) == d)
op = gimple_assign_rhs2 (stmt);
break;
case COND_EXPR:
switch (TREE_CODE (gimple_assign_rhs1 (stmt)))
{
case EQ_EXPR:
case NE_EXPR:
op = gimple_assign_rhs1 (stmt);
if (TREE_OPERAND (op, 0) != d)
{
op = NULL_TREE;
break;
}
loc = EXPR_LOC_OR_LOC (op, loc);
op = TREE_OPERAND (op, 1);
break;
default:
break;
}
break;
default:
break;
}
if (op
&& (POINTER_TYPE_P (TREE_TYPE (arg))
? integer_zerop (op) : integer_minus_onep (op))
&& !gimple_no_warning_p (stmt))
warning_at (loc, OPT_Wnonnull_compare,
"nonnull argument %qD compared to NULL", arg);
}
}
namespace {
const pass_data pass_data_warn_nonnull_compare =
{
GIMPLE_PASS, /* type */
"*nonnullcmp", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_NONE, /* tv_id */
PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_warn_nonnull_compare : public gimple_opt_pass
{
public:
pass_warn_nonnull_compare (gcc::context *ctxt)
: gimple_opt_pass (pass_data_warn_nonnull_compare, ctxt)
{}
/* opt_pass methods: */
virtual bool gate (function *) { return warn_nonnull_compare; }
virtual unsigned int execute (function *);
}; // class pass_warn_nonnull_compare
unsigned int
pass_warn_nonnull_compare::execute (function *fun)
{
if (fun->static_chain_decl)
do_warn_nonnull_compare (fun, fun->static_chain_decl);
for (tree arg = DECL_ARGUMENTS (cfun->decl); arg; arg = DECL_CHAIN (arg))
do_warn_nonnull_compare (fun, arg);
return 0;
}
} // anon namespace
gimple_opt_pass *
make_pass_warn_nonnull_compare (gcc::context *ctxt)
{
return new pass_warn_nonnull_compare (ctxt);
}
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