tree
lambda_return_type (tree expr)
{
if (expr == NULL_TREE)
return void_type_node;
if (type_unknown_p (expr)
|| BRACE_ENCLOSED_INITIALIZER_P (expr))
{
cxx_incomplete_type_error (expr, TREE_TYPE (expr));
return void_type_node;
}
gcc_checking_assert (!type_dependent_expression_p (expr));
return cv_unqualified (type_decays_to (unlowered_expr_type (expr)));
}
static tree
prepare_eh_type (tree type)
{
if (type == NULL_TREE)
return type;
if (type == error_mark_node)
return error_mark_node;
/* peel back references, so they match. */
type = non_reference (type);
/* Peel off cv qualifiers. */
type = TYPE_MAIN_VARIANT (type);
/* Functions and arrays decay to pointers. */
type = type_decays_to (type);
return type;
}
tree
build_throw (tree exp)
{
if (exp == error_mark_node)
return exp;
if (processing_template_decl)
{
if (cfun)
current_function_returns_abnormally = 1;
exp = build_min (THROW_EXPR, void_type_node, exp);
SET_EXPR_LOCATION (exp, input_location);
return exp;
}
if (exp && null_node_p (exp))
warning (0, "throwing NULL, which has integral, not pointer type");
if (exp != NULL_TREE)
{
if (!is_admissible_throw_operand_or_catch_parameter (exp, true))
return error_mark_node;
}
if (! doing_eh ())
return error_mark_node;
if (exp)
{
tree throw_type;
tree temp_type;
tree cleanup;
tree object, ptr;
tree tmp;
tree allocate_expr;
/* The CLEANUP_TYPE is the internal type of a destructor. */
if (!cleanup_type)
{
tmp = build_function_type_list (void_type_node,
ptr_type_node, NULL_TREE);
cleanup_type = build_pointer_type (tmp);
}
if (!throw_fn)
{
tree name = get_identifier ("__cxa_throw");
throw_fn = get_global_binding (name);
if (!throw_fn)
{
/* Declare void __cxa_throw (void*, void*, void (*)(void*)). */
/* ??? Second argument is supposed to be "std::type_info*". */
tmp = build_function_type_list (void_type_node,
ptr_type_node, ptr_type_node,
cleanup_type, NULL_TREE);
throw_fn = push_throw_library_fn (name, tmp);
if (flag_tm)
{
tree itm_name = get_identifier ("_ITM_cxa_throw");
tree itm_fn = get_global_binding (itm_name);
if (!itm_fn)
itm_fn = push_throw_library_fn (itm_name, tmp);
apply_tm_attr (itm_fn, get_identifier ("transaction_pure"));
record_tm_replacement (throw_fn, itm_fn);
}
}
}
/* [except.throw]
A throw-expression initializes a temporary object, the type
of which is determined by removing any top-level
cv-qualifiers from the static type of the operand of throw
and adjusting the type from "array of T" or "function return
T" to "pointer to T" or "pointer to function returning T"
respectively. */
temp_type = is_bitfield_expr_with_lowered_type (exp);
if (!temp_type)
temp_type = cv_unqualified (type_decays_to (TREE_TYPE (exp)));
/* OK, this is kind of wacky. The standard says that we call
terminate when the exception handling mechanism, after
completing evaluation of the expression to be thrown but
before the exception is caught (_except.throw_), calls a
user function that exits via an uncaught exception.
So we have to protect the actual initialization of the
exception object with terminate(), but evaluate the
expression first. Since there could be temps in the
expression, we need to handle that, too. We also expand
the call to __cxa_allocate_exception first (which doesn't
matter, since it can't throw). */
/* Allocate the space for the exception. */
allocate_expr = do_allocate_exception (temp_type);
allocate_expr = get_target_expr (allocate_expr);
ptr = TARGET_EXPR_SLOT (allocate_expr);
TARGET_EXPR_CLEANUP (allocate_expr) = do_free_exception (ptr);
CLEANUP_EH_ONLY (allocate_expr) = 1;
object = build_nop (build_pointer_type (temp_type), ptr);
object = cp_build_fold_indirect_ref (object);
/* And initialize the exception object. */
if (CLASS_TYPE_P (temp_type))
{
int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
vec<tree, va_gc> *exp_vec;
bool converted = false;
/* Under C++0x [12.8/16 class.copy], a thrown lvalue is sometimes
treated as an rvalue for the purposes of overload resolution
to favor move constructors over copy constructors. */
if (/* Must be a local, automatic variable. */
VAR_P (exp)
&& DECL_CONTEXT (exp) == current_function_decl
&& ! TREE_STATIC (exp)
/* The variable must not have the `volatile' qualifier. */
&& !(cp_type_quals (TREE_TYPE (exp)) & TYPE_QUAL_VOLATILE))
{
tree moved = move (exp);
exp_vec = make_tree_vector_single (moved);
moved = (build_special_member_call
(object, complete_ctor_identifier, &exp_vec,
TREE_TYPE (object), flags|LOOKUP_PREFER_RVALUE,
tf_none));
release_tree_vector (exp_vec);
if (moved != error_mark_node)
{
exp = moved;
converted = true;
}
}
/* Call the copy constructor. */
if (!converted)
{
exp_vec = make_tree_vector_single (exp);
exp = (build_special_member_call
(object, complete_ctor_identifier, &exp_vec,
TREE_TYPE (object), flags, tf_warning_or_error));
release_tree_vector (exp_vec);
}
if (exp == error_mark_node)
{
error (" in thrown expression");
return error_mark_node;
}
}
else
{
tmp = decay_conversion (exp, tf_warning_or_error);
if (tmp == error_mark_node)
return error_mark_node;
exp = build2 (INIT_EXPR, temp_type, object, tmp);
}
/* Mark any cleanups from the initialization as MUST_NOT_THROW, since
they are run after the exception object is initialized. */
cp_walk_tree_without_duplicates (&exp, wrap_cleanups_r, 0);
/* Prepend the allocation. */
exp = build2 (COMPOUND_EXPR, TREE_TYPE (exp), allocate_expr, exp);
/* Force all the cleanups to be evaluated here so that we don't have
to do them during unwinding. */
exp = build1 (CLEANUP_POINT_EXPR, void_type_node, exp);
throw_type = build_eh_type_type (prepare_eh_type (TREE_TYPE (object)));
cleanup = NULL_TREE;
if (type_build_dtor_call (TREE_TYPE (object)))
{
tree dtor_fn = lookup_fnfields (TYPE_BINFO (TREE_TYPE (object)),
complete_dtor_identifier, 0);
dtor_fn = BASELINK_FUNCTIONS (dtor_fn);
mark_used (dtor_fn);
if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (object)))
{
cxx_mark_addressable (dtor_fn);
/* Pretend it's a normal function. */
cleanup = build1 (ADDR_EXPR, cleanup_type, dtor_fn);
}
}
if (cleanup == NULL_TREE)
cleanup = build_int_cst (cleanup_type, 0);
/* ??? Indicate that this function call throws throw_type. */
tmp = cp_build_function_call_nary (throw_fn, tf_warning_or_error,
ptr, throw_type, cleanup, NULL_TREE);
/* Tack on the initialization stuff. */
exp = build2 (COMPOUND_EXPR, TREE_TYPE (tmp), exp, tmp);
}
else
{
/* Rethrow current exception. */
if (!rethrow_fn)
{
tree name = get_identifier ("__cxa_rethrow");
rethrow_fn = get_global_binding (name);
if (!rethrow_fn)
/* Declare void __cxa_rethrow (void). */
rethrow_fn = push_throw_library_fn
(name, build_function_type_list (void_type_node, NULL_TREE));
if (flag_tm)
apply_tm_attr (rethrow_fn, get_identifier ("transaction_pure"));
}
/* ??? Indicate that this function call allows exceptions of the type
of the enclosing catch block (if known). */
exp = cp_build_function_call_vec (rethrow_fn, NULL, tf_warning_or_error);
}
exp = build1 (THROW_EXPR, void_type_node, exp);
SET_EXPR_LOCATION (exp, input_location);
return exp;
}
