int
cp_empty_type_p (tree exp)
{
gcc_assert(TYPE_P(exp));
if (VOID_TYPE_P(exp))
return 0;
/* C++ classes with non-trivial constructors or non-trivial
assignment operators are assumed non-empty, thus assignments of
these types can't be elided. */
if (CLASS_TYPE_P(exp)
&& (TYPE_HAS_COMPLEX_INIT_REF(exp)
|| TYPE_HAS_COMPLEX_ASSIGN_REF(exp)))
return 0;
return is_empty_class(exp);
}
tree
cp_expr_size (tree exp)
{
tree type = TREE_TYPE (exp);
if (CLASS_TYPE_P (type))
{
/* The backend should not be interested in the size of an expression
of a type with both of these set; all copies of such types must go
through a constructor or assignment op. */
gcc_assert (!TYPE_HAS_COMPLEX_INIT_REF (type)
|| !TYPE_HAS_COMPLEX_ASSIGN_REF (type)
/* But storing a CONSTRUCTOR isn't a copy. */
|| TREE_CODE (exp) == CONSTRUCTOR
/* And, the gimplifier will sometimes make a copy of
an aggregate. In particular, for a case like:
struct S { S(); };
struct X { int a; S s; };
X x = { 0 };
the gimplifier will create a temporary with
static storage duration, perform static
initialization of the temporary, and then copy
the result. Since the "s" subobject is never
constructed, this is a valid transformation. */
|| CP_AGGREGATE_TYPE_P (type));
/* This would be wrong for a type with virtual bases, but they are
caught by the assert above. */
return (is_empty_class (type)
? size_zero_node
: CLASSTYPE_SIZE_UNIT (type));
}
else
/* Use the default code. */
return lhd_expr_size (exp);
}
static tree
cp_expr_size (tree exp)
{
if (CLASS_TYPE_P (TREE_TYPE (exp)))
{
/* The backend should not be interested in the size of an expression
of a type with both of these set; all copies of such types must go
through a constructor or assignment op. */
if (TYPE_HAS_COMPLEX_INIT_REF (TREE_TYPE (exp))
&& TYPE_HAS_COMPLEX_ASSIGN_REF (TREE_TYPE (exp))
/* But storing a CONSTRUCTOR isn't a copy. */
&& TREE_CODE (exp) != CONSTRUCTOR)
abort ();
/* This would be wrong for a type with virtual bases, but they are
caught by the abort above. */
return (is_empty_class (TREE_TYPE (exp))
? size_zero_node
: CLASSTYPE_SIZE_UNIT (TREE_TYPE (exp)));
}
else
/* Use the default code. */
return lhd_expr_size (exp);
}
static void
do_build_assign_ref (tree fndecl)
{
tree parm = TREE_CHAIN (DECL_ARGUMENTS (fndecl));
tree compound_stmt;
compound_stmt = begin_compound_stmt (0);
parm = convert_from_reference (parm);
if (TYPE_HAS_TRIVIAL_ASSIGN_REF (current_class_type)
&& is_empty_class (current_class_type))
/* Don't copy the padding byte; it might not have been allocated
if *this is a base subobject. */;
else if (TYPE_HAS_TRIVIAL_ASSIGN_REF (current_class_type))
{
tree t = build2 (MODIFY_EXPR, void_type_node, current_class_ref, parm);
finish_expr_stmt (t);
}
else
{
tree fields;
int cvquals = cp_type_quals (TREE_TYPE (parm));
int i;
tree binfo, base_binfo;
/* Assign to each of the direct base classes. */
for (binfo = TYPE_BINFO (current_class_type), i = 0;
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
{
tree converted_parm;
/* We must convert PARM directly to the base class
explicitly since the base class may be ambiguous. */
converted_parm = build_base_path (PLUS_EXPR, parm, base_binfo, 1);
/* Call the base class assignment operator. */
finish_expr_stmt
(build_special_member_call (current_class_ref,
ansi_assopname (NOP_EXPR),
build_tree_list (NULL_TREE,
converted_parm),
base_binfo,
LOOKUP_NORMAL | LOOKUP_NONVIRTUAL));
}
/* Assign to each of the non-static data members. */
for (fields = TYPE_FIELDS (current_class_type);
fields;
fields = TREE_CHAIN (fields))
{
tree comp = current_class_ref;
tree init = parm;
tree field = fields;
tree expr_type;
int quals;
if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
continue;
expr_type = TREE_TYPE (field);
if (CP_TYPE_CONST_P (expr_type))
{
error ("non-static const member %q#D, can't use default "
"assignment operator", field);
continue;
}
else if (TREE_CODE (expr_type) == REFERENCE_TYPE)
{
error ("non-static reference member %q#D, can't use "
"default assignment operator", field);
continue;
}
if (DECL_NAME (field))
{
if (VFIELD_NAME_P (DECL_NAME (field)))
continue;
}
else if (ANON_AGGR_TYPE_P (expr_type)
&& TYPE_FIELDS (expr_type) != NULL_TREE)
/* Just use the field; anonymous types can't have
nontrivial copy ctors or assignment ops. */;
else
continue;
comp = build3 (COMPONENT_REF, expr_type, comp, field, NULL_TREE);
/* Compute the type of init->field */
quals = cvquals;
if (DECL_MUTABLE_P (field))
quals &= ~TYPE_QUAL_CONST;
expr_type = cp_build_qualified_type (expr_type, quals);
init = build3 (COMPONENT_REF, expr_type, init, field, NULL_TREE);
if (DECL_NAME (field))
init = build_modify_expr (comp, NOP_EXPR, init);
else
init = build2 (MODIFY_EXPR, TREE_TYPE (comp), comp, init);
finish_expr_stmt (init);
}
}
finish_return_stmt (current_class_ref);
finish_compound_stmt (compound_stmt);
}
static void
do_build_copy_constructor (tree fndecl)
{
tree parm = FUNCTION_FIRST_USER_PARM (fndecl);
parm = convert_from_reference (parm);
if (TYPE_HAS_TRIVIAL_INIT_REF (current_class_type)
&& is_empty_class (current_class_type))
/* Don't copy the padding byte; it might not have been allocated
if *this is a base subobject. */;
else if (TYPE_HAS_TRIVIAL_INIT_REF (current_class_type))
{
tree t = build2 (INIT_EXPR, void_type_node, current_class_ref, parm);
finish_expr_stmt (t);
}
else
{
tree fields = TYPE_FIELDS (current_class_type);
tree member_init_list = NULL_TREE;
int cvquals = cp_type_quals (TREE_TYPE (parm));
int i;
tree binfo, base_binfo;
VEC(tree,gc) *vbases;
/* Initialize all the base-classes with the parameter converted
to their type so that we get their copy constructor and not
another constructor that takes current_class_type. We must
deal with the binfo's directly as a direct base might be
inaccessible due to ambiguity. */
for (vbases = CLASSTYPE_VBASECLASSES (current_class_type), i = 0;
VEC_iterate (tree, vbases, i, binfo); i++)
{
member_init_list
= tree_cons (binfo,
build_tree_list (NULL_TREE,
build_base_path (PLUS_EXPR, parm,
binfo, 1)),
member_init_list);
}
for (binfo = TYPE_BINFO (current_class_type), i = 0;
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
{
if (BINFO_VIRTUAL_P (base_binfo))
continue;
member_init_list
= tree_cons (base_binfo,
build_tree_list (NULL_TREE,
build_base_path (PLUS_EXPR, parm,
base_binfo, 1)),
member_init_list);
}
for (; fields; fields = TREE_CHAIN (fields))
{
tree init = parm;
tree field = fields;
tree expr_type;
if (TREE_CODE (field) != FIELD_DECL)
continue;
expr_type = TREE_TYPE (field);
if (DECL_NAME (field))
{
if (VFIELD_NAME_P (DECL_NAME (field)))
continue;
}
else if (ANON_AGGR_TYPE_P (expr_type) && TYPE_FIELDS (expr_type))
/* Just use the field; anonymous types can't have
nontrivial copy ctors or assignment ops. */;
else
continue;
/* Compute the type of "init->field". If the copy-constructor
parameter is, for example, "const S&", and the type of
the field is "T", then the type will usually be "const
T". (There are no cv-qualified variants of reference
types.) */
if (TREE_CODE (expr_type) != REFERENCE_TYPE)
{
int quals = cvquals;
if (DECL_MUTABLE_P (field))
quals &= ~TYPE_QUAL_CONST;
expr_type = cp_build_qualified_type (expr_type, quals);
}
init = build3 (COMPONENT_REF, expr_type, init, field, NULL_TREE);
init = build_tree_list (NULL_TREE, init);
member_init_list = tree_cons (field, init, member_init_list);
}
finish_mem_initializers (member_init_list);
}
}