static tree
build_up_reference (tree type, tree arg, int flags, tree decl)
{
tree rval;
tree argtype = TREE_TYPE (arg);
tree target_type = TREE_TYPE (type);
gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
if ((flags & DIRECT_BIND) && ! real_lvalue_p (arg))
{
/* Create a new temporary variable. We can't just use a TARGET_EXPR
here because it needs to live as long as DECL. */
tree targ = arg;
arg = make_temporary_var_for_ref_to_temp (decl, TREE_TYPE (arg));
/* Process the initializer for the declaration. */
DECL_INITIAL (arg) = targ;
cp_finish_decl (arg, targ, /*init_const_expr_p=*/false, NULL_TREE,
LOOKUP_ONLYCONVERTING|DIRECT_BIND);
}
else if (!(flags & DIRECT_BIND) && ! lvalue_p (arg))
return get_target_expr (arg);
/* If we had a way to wrap this up, and say, if we ever needed its
address, transform all occurrences of the register, into a memory
reference we could win better. */
rval = cp_build_unary_op (ADDR_EXPR, arg, 1, tf_warning_or_error);
if (rval == error_mark_node)
return error_mark_node;
if ((flags & LOOKUP_PROTECT)
&& TYPE_MAIN_VARIANT (argtype) != TYPE_MAIN_VARIANT (target_type)
&& MAYBE_CLASS_TYPE_P (argtype)
&& MAYBE_CLASS_TYPE_P (target_type))
{
/* We go through lookup_base for the access control. */
tree binfo = lookup_base (argtype, target_type, ba_check, NULL);
if (binfo == error_mark_node)
return error_mark_node;
if (binfo == NULL_TREE)
return error_not_base_type (target_type, argtype);
rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
}
else
rval
= convert_to_pointer_force (build_pointer_type (target_type), rval);
return build_nop (type, rval);
}
tree
add_capture (tree lambda, tree id, tree orig_init, bool by_reference_p,
bool explicit_init_p)
{
char *buf;
tree type, member, name;
bool vla = false;
bool variadic = false;
tree initializer = orig_init;
if (PACK_EXPANSION_P (initializer))
{
initializer = PACK_EXPANSION_PATTERN (initializer);
variadic = true;
}
if (TREE_CODE (initializer) == TREE_LIST)
initializer = build_x_compound_expr_from_list (initializer, ELK_INIT,
tf_warning_or_error);
type = TREE_TYPE (initializer);
if (type == error_mark_node)
return error_mark_node;
if (array_of_runtime_bound_p (type))
{
vla = true;
if (!by_reference_p)
error ("array of runtime bound cannot be captured by copy, "
"only by reference");
/* For a VLA, we capture the address of the first element and the
maximum index, and then reconstruct the VLA for the proxy. */
tree elt = cp_build_array_ref (input_location, initializer,
integer_zero_node, tf_warning_or_error);
initializer = build_constructor_va (init_list_type_node, 2,
NULL_TREE, build_address (elt),
NULL_TREE, array_type_nelts (type));
type = vla_capture_type (type);
}
else if (!dependent_type_p (type)
&& variably_modified_type_p (type, NULL_TREE))
{
error ("capture of variable-size type %qT that is not an N3639 array "
"of runtime bound", type);
if (TREE_CODE (type) == ARRAY_TYPE
&& variably_modified_type_p (TREE_TYPE (type), NULL_TREE))
inform (input_location, "because the array element type %qT has "
"variable size", TREE_TYPE (type));
type = error_mark_node;
}
else
{
type = lambda_capture_field_type (initializer, explicit_init_p);
if (by_reference_p)
{
type = build_reference_type (type);
if (!dependent_type_p (type) && !real_lvalue_p (initializer))
error ("cannot capture %qE by reference", initializer);
}
else
{
/* Capture by copy requires a complete type. */
type = complete_type (type);
if (!dependent_type_p (type) && !COMPLETE_TYPE_P (type))
{
error ("capture by copy of incomplete type %qT", type);
cxx_incomplete_type_inform (type);
return error_mark_node;
}
}
}
/* Add __ to the beginning of the field name so that user code
won't find the field with name lookup. We can't just leave the name
unset because template instantiation uses the name to find
instantiated fields. */
buf = (char *) alloca (IDENTIFIER_LENGTH (id) + 3);
buf[1] = buf[0] = '_';
memcpy (buf + 2, IDENTIFIER_POINTER (id),
IDENTIFIER_LENGTH (id) + 1);
name = get_identifier (buf);
/* If TREE_TYPE isn't set, we're still in the introducer, so check
for duplicates. */
if (!LAMBDA_EXPR_CLOSURE (lambda))
{
if (IDENTIFIER_MARKED (name))
{
pedwarn (input_location, 0,
"already captured %qD in lambda expression", id);
return NULL_TREE;
}
IDENTIFIER_MARKED (name) = true;
}
if (variadic)
type = make_pack_expansion (type);
/* Make member variable. */
member = build_decl (input_location, FIELD_DECL, name, type);
DECL_VLA_CAPTURE_P (member) = vla;
if (!explicit_init_p)
/* Normal captures are invisible to name lookup but uses are replaced
with references to the capture field; we implement this by only
really making them invisible in unevaluated context; see
qualify_lookup. For now, let's make explicitly initialized captures
always visible. */
DECL_NORMAL_CAPTURE_P (member) = true;
if (id == this_identifier)
LAMBDA_EXPR_THIS_CAPTURE (lambda) = member;
/* Add it to the appropriate closure class if we've started it. */
if (current_class_type
&& current_class_type == LAMBDA_EXPR_CLOSURE (lambda))
finish_member_declaration (member);
tree listmem = member;
if (variadic)
{
listmem = make_pack_expansion (member);
initializer = orig_init;
}
LAMBDA_EXPR_CAPTURE_LIST (lambda)
= tree_cons (listmem, initializer, LAMBDA_EXPR_CAPTURE_LIST (lambda));
if (LAMBDA_EXPR_CLOSURE (lambda))
return build_capture_proxy (member);
/* For explicit captures we haven't started the function yet, so we wait
and build the proxy from cp_parser_lambda_body. */
return NULL_TREE;
}
tree
convert_to_reference (tree reftype, tree expr, int convtype,
int flags, tree decl)
{
tree type = TYPE_MAIN_VARIANT (TREE_TYPE (reftype));
tree intype;
tree rval = NULL_TREE;
tree rval_as_conversion = NULL_TREE;
bool can_convert_intype_to_type;
if (TREE_CODE (type) == FUNCTION_TYPE
&& TREE_TYPE (expr) == unknown_type_node)
expr = instantiate_type (type, expr,
(flags & LOOKUP_COMPLAIN)
? tf_warning_or_error : tf_none);
if (expr == error_mark_node)
return error_mark_node;
intype = TREE_TYPE (expr);
gcc_assert (TREE_CODE (intype) != REFERENCE_TYPE);
gcc_assert (TREE_CODE (reftype) == REFERENCE_TYPE);
intype = TYPE_MAIN_VARIANT (intype);
can_convert_intype_to_type = can_convert (type, intype);
if (!can_convert_intype_to_type
&& (convtype & CONV_IMPLICIT) && MAYBE_CLASS_TYPE_P (intype)
&& ! (flags & LOOKUP_NO_CONVERSION))
{
/* Look for a user-defined conversion to lvalue that we can use. */
rval_as_conversion
= build_type_conversion (reftype, expr);
if (rval_as_conversion && rval_as_conversion != error_mark_node
&& real_lvalue_p (rval_as_conversion))
{
expr = rval_as_conversion;
rval_as_conversion = NULL_TREE;
intype = type;
can_convert_intype_to_type = 1;
}
}
if (((convtype & CONV_STATIC) && can_convert (intype, type))
|| ((convtype & CONV_IMPLICIT) && can_convert_intype_to_type))
{
if (flags & LOOKUP_COMPLAIN)
{
tree ttl = TREE_TYPE (reftype);
tree ttr = lvalue_type (expr);
if (! real_lvalue_p (expr))
warn_ref_binding (reftype, intype, decl);
if (! (convtype & CONV_CONST)
&& !at_least_as_qualified_p (ttl, ttr))
permerror (input_location, "conversion from %qT to %qT discards qualifiers",
ttr, reftype);
}
return build_up_reference (reftype, expr, flags, decl);
}
else if ((convtype & CONV_REINTERPRET) && lvalue_p (expr))
{
/* When casting an lvalue to a reference type, just convert into
a pointer to the new type and deference it. This is allowed
by San Diego WP section 5.2.9 paragraph 12, though perhaps it
should be done directly (jason). (int &)ri ---> *(int*)&ri */
/* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they
meant. */
if (TREE_CODE (intype) == POINTER_TYPE
&& (comptypes (TREE_TYPE (intype), type,
COMPARE_BASE | COMPARE_DERIVED)))
warning (0, "casting %qT to %qT does not dereference pointer",
intype, reftype);
rval = cp_build_unary_op (ADDR_EXPR, expr, 0, tf_warning_or_error);
if (rval != error_mark_node)
rval = convert_force (build_pointer_type (TREE_TYPE (reftype)),
rval, 0);
if (rval != error_mark_node)
rval = build1 (NOP_EXPR, reftype, rval);
}
else
{
rval = convert_for_initialization (NULL_TREE, type, expr, flags,
"converting", 0, 0,
tf_warning_or_error);
if (rval == NULL_TREE || rval == error_mark_node)
return rval;
warn_ref_binding (reftype, intype, decl);
rval = build_up_reference (reftype, rval, flags, decl);
}
if (rval)
{
/* If we found a way to convert earlier, then use it. */
return rval;
}
if (flags & LOOKUP_COMPLAIN)
error ("cannot convert type %qT to type %qT", intype, reftype);
return error_mark_node;
}
