static void
instrument_si_overflow (gimple_stmt_iterator gsi)
{
gimple stmt = gsi_stmt (gsi);
tree_code code = gimple_assign_rhs_code (stmt);
tree lhs = gimple_assign_lhs (stmt);
tree lhstype = TREE_TYPE (lhs);
tree a, b;
gimple g;
/* If this is not a signed operation, don't instrument anything here.
Also punt on bit-fields. */
if (!INTEGRAL_TYPE_P (lhstype)
|| TYPE_OVERFLOW_WRAPS (lhstype)
|| GET_MODE_BITSIZE (TYPE_MODE (lhstype)) != TYPE_PRECISION (lhstype))
return;
switch (code)
{
case MINUS_EXPR:
case PLUS_EXPR:
case MULT_EXPR:
/* Transform
i = u {+,-,*} 5;
into
i = UBSAN_CHECK_{ADD,SUB,MUL} (u, 5); */
a = gimple_assign_rhs1 (stmt);
b = gimple_assign_rhs2 (stmt);
g = gimple_build_call_internal (code == PLUS_EXPR
? IFN_UBSAN_CHECK_ADD
: code == MINUS_EXPR
? IFN_UBSAN_CHECK_SUB
: IFN_UBSAN_CHECK_MUL, 2, a, b);
gimple_call_set_lhs (g, lhs);
gsi_replace (&gsi, g, false);
break;
case NEGATE_EXPR:
/* Represent i = -u;
as
i = UBSAN_CHECK_SUB (0, u); */
a = build_int_cst (lhstype, 0);
b = gimple_assign_rhs1 (stmt);
g = gimple_build_call_internal (IFN_UBSAN_CHECK_SUB, 2, a, b);
gimple_call_set_lhs (g, lhs);
gsi_replace (&gsi, g, false);
break;
default:
break;
}
}
static void
instrument_member_call (gimple_stmt_iterator *iter)
{
tree this_parm = gimple_call_arg (gsi_stmt (*iter), 0);
tree kind = build_int_cst (unsigned_char_type_node, UBSAN_MEMBER_CALL);
gimple g = gimple_build_call_internal (IFN_UBSAN_NULL, 2, this_parm, kind);
gimple_set_location (g, gimple_location (gsi_stmt (*iter)));
gsi_insert_before (iter, g, GSI_SAME_STMT);
}
static void
instrument_mem_ref (tree t, gimple_stmt_iterator *iter, bool is_lhs)
{
enum ubsan_null_ckind ikind = is_lhs ? UBSAN_STORE_OF : UBSAN_LOAD_OF;
if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (TREE_TYPE (t))))
ikind = UBSAN_MEMBER_ACCESS;
tree kind = build_int_cst (unsigned_char_type_node, ikind);
gimple g = gimple_build_call_internal (IFN_UBSAN_NULL, 2, t, kind);
gimple_set_location (g, gimple_location (gsi_stmt (*iter)));
gsi_insert_before (iter, g, GSI_SAME_STMT);
}
static gcall *
build_call_internal (internal_fn fn, tree type, unsigned int nargs, tree *ops)
{
if (direct_internal_fn_p (fn))
{
tree_pair types = direct_internal_fn_types (fn, type, ops);
if (!direct_internal_fn_supported_p (fn, types, OPTIMIZE_FOR_BOTH))
return NULL;
}
return gimple_build_call_internal (fn, nargs, ops[0], ops[1], ops[2]);
}
static void
use_internal_fn (gcall *call)
{
/* We'll be inserting another call with the same arguments after the
lhs has been set, so prevent any possible coalescing failure from
having both values live at once. See PR 71020. */
replace_abnormal_ssa_names (call);
unsigned nconds = 0;
auto_vec<gimple *, 12> conds;
if (can_test_argument_range (call))
{
gen_shrink_wrap_conditions (call, conds, &nconds);
gcc_assert (nconds != 0);
}
else
gcc_assert (edom_only_function (call));
internal_fn ifn = replacement_internal_fn (call);
gcc_assert (ifn != IFN_LAST);
/* Construct the new call, with the same arguments as the original one. */
auto_vec <tree, 16> args;
unsigned int nargs = gimple_call_num_args (call);
for (unsigned int i = 0; i < nargs; ++i)
args.safe_push (gimple_call_arg (call, i));
gcall *new_call = gimple_build_call_internal_vec (ifn, args);
gimple_set_location (new_call, gimple_location (call));
gimple_call_set_nothrow (new_call, gimple_call_nothrow_p (call));
/* Transfer the LHS to the new call. */
tree lhs = gimple_call_lhs (call);
gimple_call_set_lhs (new_call, lhs);
gimple_call_set_lhs (call, NULL_TREE);
SSA_NAME_DEF_STMT (lhs) = new_call;
/* Insert the new call. */
gimple_stmt_iterator gsi = gsi_for_stmt (call);
gsi_insert_before (&gsi, new_call, GSI_SAME_STMT);
if (nconds == 0)
{
/* Skip the call if LHS == LHS. If we reach here, EDOM is the only
valid errno value and it is used iff the result is NaN. */
conds.quick_push (gimple_build_cond (EQ_EXPR, lhs, lhs,
NULL_TREE, NULL_TREE));
nconds++;
/* Try replacing the original call with a direct assignment to
errno, via an internal function. */
if (set_edom_supported_p () && !stmt_ends_bb_p (call))
{
gimple_stmt_iterator gsi = gsi_for_stmt (call);
gcall *new_call = gimple_build_call_internal (IFN_SET_EDOM, 0);
gimple_set_vuse (new_call, gimple_vuse (call));
gimple_set_vdef (new_call, gimple_vdef (call));
SSA_NAME_DEF_STMT (gimple_vdef (new_call)) = new_call;
gimple_set_location (new_call, gimple_location (call));
gsi_replace (&gsi, new_call, false);
call = new_call;
}
}
shrink_wrap_one_built_in_call_with_conds (call, conds, nconds);
}
