static unsigned HOST_WIDE_INT
addr_object_size (struct object_size_info *osi, const_tree ptr,
int object_size_type)
{
tree pt_var, pt_var_size = NULL_TREE, var_size, bytes;
gcc_assert (TREE_CODE (ptr) == ADDR_EXPR);
pt_var = TREE_OPERAND (ptr, 0);
while (handled_component_p (pt_var))
pt_var = TREE_OPERAND (pt_var, 0);
if (pt_var
&& TREE_CODE (pt_var) == MEM_REF)
{
unsigned HOST_WIDE_INT sz;
if (!osi || (object_size_type & 1) != 0
|| TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME)
{
sz = compute_builtin_object_size (TREE_OPERAND (pt_var, 0),
object_size_type & ~1);
}
else
{
tree var = TREE_OPERAND (pt_var, 0);
if (osi->pass == 0)
collect_object_sizes_for (osi, var);
if (bitmap_bit_p (computed[object_size_type],
SSA_NAME_VERSION (var)))
sz = object_sizes[object_size_type][SSA_NAME_VERSION (var)];
else
sz = unknown[object_size_type];
}
if (sz != unknown[object_size_type])
{
double_int dsz = double_int::from_uhwi (sz) - mem_ref_offset (pt_var);
if (dsz.is_negative ())
sz = 0;
else if (dsz.fits_uhwi ())
sz = dsz.to_uhwi ();
else
sz = unknown[object_size_type];
}
if (sz != unknown[object_size_type] && sz < offset_limit)
pt_var_size = size_int (sz);
}
else if (pt_var
&& DECL_P (pt_var)
&& host_integerp (DECL_SIZE_UNIT (pt_var), 1)
&& (unsigned HOST_WIDE_INT)
tree_low_cst (DECL_SIZE_UNIT (pt_var), 1) < offset_limit)
pt_var_size = DECL_SIZE_UNIT (pt_var);
else if (pt_var
&& TREE_CODE (pt_var) == STRING_CST
&& TYPE_SIZE_UNIT (TREE_TYPE (pt_var))
&& host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)), 1)
&& (unsigned HOST_WIDE_INT)
tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (pt_var)), 1)
< offset_limit)
pt_var_size = TYPE_SIZE_UNIT (TREE_TYPE (pt_var));
else
return unknown[object_size_type];
if (pt_var != TREE_OPERAND (ptr, 0))
{
tree var;
if (object_size_type & 1)
{
var = TREE_OPERAND (ptr, 0);
while (var != pt_var
&& TREE_CODE (var) != BIT_FIELD_REF
&& TREE_CODE (var) != COMPONENT_REF
&& TREE_CODE (var) != ARRAY_REF
&& TREE_CODE (var) != ARRAY_RANGE_REF
&& TREE_CODE (var) != REALPART_EXPR
&& TREE_CODE (var) != IMAGPART_EXPR)
var = TREE_OPERAND (var, 0);
if (var != pt_var && TREE_CODE (var) == ARRAY_REF)
var = TREE_OPERAND (var, 0);
if (! TYPE_SIZE_UNIT (TREE_TYPE (var))
|| ! host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (var)), 1)
|| (pt_var_size
&& tree_int_cst_lt (pt_var_size,
TYPE_SIZE_UNIT (TREE_TYPE (var)))))
var = pt_var;
else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF)
{
tree v = var;
/* For &X->fld, compute object size only if fld isn't the last
field, as struct { int i; char c[1]; } is often used instead
of flexible array member. */
while (v && v != pt_var)
switch (TREE_CODE (v))
{
case ARRAY_REF:
if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0)))
&& TREE_CODE (TREE_OPERAND (v, 1)) == INTEGER_CST)
{
tree domain
= TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0)));
if (domain
&& TYPE_MAX_VALUE (domain)
&& TREE_CODE (TYPE_MAX_VALUE (domain))
== INTEGER_CST
&& tree_int_cst_lt (TREE_OPERAND (v, 1),
TYPE_MAX_VALUE (domain)))
{
v = NULL_TREE;
break;
}
}
v = TREE_OPERAND (v, 0);
break;
case REALPART_EXPR:
case IMAGPART_EXPR:
v = NULL_TREE;
break;
case COMPONENT_REF:
if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE)
{
v = NULL_TREE;
break;
}
while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
!= UNION_TYPE
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
!= QUAL_UNION_TYPE)
break;
else
v = TREE_OPERAND (v, 0);
if (TREE_CODE (v) == COMPONENT_REF
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
== RECORD_TYPE)
{
tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1));
for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain))
if (TREE_CODE (fld_chain) == FIELD_DECL)
break;
if (fld_chain)
{
v = NULL_TREE;
break;
}
v = TREE_OPERAND (v, 0);
}
while (v != pt_var && TREE_CODE (v) == COMPONENT_REF)
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
!= UNION_TYPE
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0)))
!= QUAL_UNION_TYPE)
break;
else
v = TREE_OPERAND (v, 0);
if (v != pt_var)
v = NULL_TREE;
else
v = pt_var;
break;
default:
v = pt_var;
break;
}
if (v == pt_var)
var = pt_var;
}
}
else
var = pt_var;
if (var != pt_var)
var_size = TYPE_SIZE_UNIT (TREE_TYPE (var));
else if (!pt_var_size)
return unknown[object_size_type];
else
var_size = pt_var_size;
bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var);
if (bytes != error_mark_node)
{
if (TREE_CODE (bytes) == INTEGER_CST
&& tree_int_cst_lt (var_size, bytes))
bytes = size_zero_node;
else
bytes = size_binop (MINUS_EXPR, var_size, bytes);
}
if (var != pt_var
&& pt_var_size
&& TREE_CODE (pt_var) == MEM_REF
&& bytes != error_mark_node)
{
tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0), pt_var);
if (bytes2 != error_mark_node)
{
if (TREE_CODE (bytes2) == INTEGER_CST
&& tree_int_cst_lt (pt_var_size, bytes2))
bytes2 = size_zero_node;
else
bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2);
bytes = size_binop (MIN_EXPR, bytes, bytes2);
}
}
}
else if (!pt_var_size)
return unknown[object_size_type];
else
bytes = pt_var_size;
if (host_integerp (bytes, 1))
return tree_low_cst (bytes, 1);
return unknown[object_size_type];
}
unsigned HOST_WIDE_INT
compute_builtin_object_size (tree ptr, int object_size_type)
{
gcc_assert (object_size_type >= 0 && object_size_type <= 3);
if (! offset_limit)
init_offset_limit ();
if (TREE_CODE (ptr) == ADDR_EXPR)
return addr_object_size (ptr, object_size_type);
else if (TREE_CODE (ptr) == CALL_EXPR)
{
tree arg = pass_through_call (ptr);
if (arg)
return compute_builtin_object_size (arg, object_size_type);
else
return alloc_object_size (ptr, object_size_type);
}
else if (TREE_CODE (ptr) == SSA_NAME
&& POINTER_TYPE_P (TREE_TYPE (ptr))
&& object_sizes[object_size_type] != NULL)
{
if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr)))
{
struct object_size_info osi;
bitmap_iterator bi;
unsigned int i;
if (dump_file)
{
fprintf (dump_file, "Computing %s %sobject size for ",
(object_size_type & 2) ? "minimum" : "maximum",
(object_size_type & 1) ? "sub" : "");
print_generic_expr (dump_file, ptr, dump_flags);
fprintf (dump_file, ":\n");
}
osi.visited = BITMAP_ALLOC (NULL);
osi.reexamine = BITMAP_ALLOC (NULL);
osi.object_size_type = object_size_type;
osi.depths = NULL;
osi.stack = NULL;
osi.tos = NULL;
/* First pass: walk UD chains, compute object sizes that
can be computed. osi.reexamine bitmap at the end will
contain what variables were found in dependency cycles
and therefore need to be reexamined. */
osi.pass = 0;
osi.changed = false;
collect_object_sizes_for (&osi, ptr);
/* Second pass: keep recomputing object sizes of variables
that need reexamination, until no object sizes are
increased or all object sizes are computed. */
if (! bitmap_empty_p (osi.reexamine))
{
bitmap reexamine = BITMAP_ALLOC (NULL);
/* If looking for minimum instead of maximum object size,
detect cases where a pointer is increased in a loop.
Although even without this detection pass 2 would eventually
terminate, it could take a long time. If a pointer is
increasing this way, we need to assume 0 object size.
E.g. p = &buf[0]; while (cond) p = p + 4; */
if (object_size_type & 2)
{
osi.depths = xcalloc (num_ssa_names, sizeof (unsigned int));
osi.stack = xmalloc (num_ssa_names * sizeof (unsigned int));
osi.tos = osi.stack;
osi.pass = 1;
/* collect_object_sizes_for is changing
osi.reexamine bitmap, so iterate over a copy. */
bitmap_copy (reexamine, osi.reexamine);
EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi)
if (bitmap_bit_p (osi.reexamine, i))
check_for_plus_in_loops (&osi, ssa_name (i));
free (osi.depths);
osi.depths = NULL;
free (osi.stack);
osi.stack = NULL;
osi.tos = NULL;
}
do
{
osi.pass = 2;
osi.changed = false;
/* collect_object_sizes_for is changing
osi.reexamine bitmap, so iterate over a copy. */
bitmap_copy (reexamine, osi.reexamine);
EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi)
if (bitmap_bit_p (osi.reexamine, i))
{
collect_object_sizes_for (&osi, ssa_name (i));
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Reexamining ");
print_generic_expr (dump_file, ssa_name (i),
dump_flags);
fprintf (dump_file, "\n");
}
}
}
while (osi.changed);
BITMAP_FREE (reexamine);
}
EXECUTE_IF_SET_IN_BITMAP (osi.reexamine, 0, i, bi)
bitmap_set_bit (computed[object_size_type], i);
/* Debugging dumps. */
if (dump_file)
{
EXECUTE_IF_SET_IN_BITMAP (osi.visited, 0, i, bi)
if (object_sizes[object_size_type][i]
!= unknown[object_size_type])
{
print_generic_expr (dump_file, ssa_name (i),
dump_flags);
fprintf (dump_file,
": %s %sobject size "
HOST_WIDE_INT_PRINT_UNSIGNED "\n",
(object_size_type & 2) ? "minimum" : "maximum",
(object_size_type & 1) ? "sub" : "",
object_sizes[object_size_type][i]);
}
}
BITMAP_FREE (osi.reexamine);
BITMAP_FREE (osi.visited);
}
bool
compute_builtin_object_size (tree ptr, int object_size_type,
unsigned HOST_WIDE_INT *psize)
{
gcc_assert (object_size_type >= 0 && object_size_type <= 3);
/* Set to unknown and overwrite just before returning if the size
could be determined. */
*psize = unknown[object_size_type];
if (! offset_limit)
init_offset_limit ();
if (TREE_CODE (ptr) == ADDR_EXPR)
return addr_object_size (NULL, ptr, object_size_type, psize);
if (TREE_CODE (ptr) != SSA_NAME
|| !POINTER_TYPE_P (TREE_TYPE (ptr)))
return false;
if (computed[object_size_type] == NULL)
{
if (optimize || object_size_type & 1)
return false;
/* When not optimizing, rather than failing, make a small effort
to determine the object size without the full benefit of
the (costly) computation below. */
gimple *def = SSA_NAME_DEF_STMT (ptr);
if (gimple_code (def) == GIMPLE_ASSIGN)
{
tree_code code = gimple_assign_rhs_code (def);
if (code == POINTER_PLUS_EXPR)
{
tree offset = gimple_assign_rhs2 (def);
ptr = gimple_assign_rhs1 (def);
if (tree_fits_shwi_p (offset)
&& compute_builtin_object_size (ptr, object_size_type, psize))
{
/* Return zero when the offset is out of bounds. */
unsigned HOST_WIDE_INT off = tree_to_shwi (offset);
*psize = off < *psize ? *psize - off : 0;
return true;
}
}
}
return false;
}
if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr)))
{
struct object_size_info osi;
bitmap_iterator bi;
unsigned int i;
if (num_ssa_names > object_sizes[object_size_type].length ())
object_sizes[object_size_type].safe_grow (num_ssa_names);
if (dump_file)
{
fprintf (dump_file, "Computing %s %sobject size for ",
(object_size_type & 2) ? "minimum" : "maximum",
(object_size_type & 1) ? "sub" : "");
print_generic_expr (dump_file, ptr, dump_flags);
fprintf (dump_file, ":\n");
}
osi.visited = BITMAP_ALLOC (NULL);
osi.reexamine = BITMAP_ALLOC (NULL);
osi.object_size_type = object_size_type;
osi.depths = NULL;
osi.stack = NULL;
osi.tos = NULL;
/* First pass: walk UD chains, compute object sizes that
can be computed. osi.reexamine bitmap at the end will
contain what variables were found in dependency cycles
and therefore need to be reexamined. */
osi.pass = 0;
osi.changed = false;
collect_object_sizes_for (&osi, ptr);
/* Second pass: keep recomputing object sizes of variables
that need reexamination, until no object sizes are
increased or all object sizes are computed. */
if (! bitmap_empty_p (osi.reexamine))
{
bitmap reexamine = BITMAP_ALLOC (NULL);
/* If looking for minimum instead of maximum object size,
detect cases where a pointer is increased in a loop.
Although even without this detection pass 2 would eventually
terminate, it could take a long time. If a pointer is
increasing this way, we need to assume 0 object size.
E.g. p = &buf[0]; while (cond) p = p + 4; */
if (object_size_type & 2)
{
osi.depths = XCNEWVEC (unsigned int, num_ssa_names);
osi.stack = XNEWVEC (unsigned int, num_ssa_names);
osi.tos = osi.stack;
osi.pass = 1;
/* collect_object_sizes_for is changing
osi.reexamine bitmap, so iterate over a copy. */
bitmap_copy (reexamine, osi.reexamine);
EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi)
if (bitmap_bit_p (osi.reexamine, i))
check_for_plus_in_loops (&osi, ssa_name (i));
free (osi.depths);
osi.depths = NULL;
free (osi.stack);
osi.stack = NULL;
osi.tos = NULL;
}
do
{
osi.pass = 2;
osi.changed = false;
/* collect_object_sizes_for is changing
osi.reexamine bitmap, so iterate over a copy. */
bitmap_copy (reexamine, osi.reexamine);
EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi)
if (bitmap_bit_p (osi.reexamine, i))
{
collect_object_sizes_for (&osi, ssa_name (i));
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Reexamining ");
print_generic_expr (dump_file, ssa_name (i),
dump_flags);
fprintf (dump_file, "\n");
}
}
}
while (osi.changed);
BITMAP_FREE (reexamine);
}
