static tree
throw_bad_cast (void)
{
tree fn = get_identifier ("__cxa_bad_cast");
if (!get_global_value_if_present (fn, &fn))
fn = push_throw_library_fn (fn, build_function_type (ptr_type_node,
void_list_node));
return build_cxx_call (fn, NULL_TREE);
}
static tree
throw_bad_typeid (void)
{
tree fn = get_identifier ("__cxa_bad_typeid");
if (!get_global_value_if_present (fn, &fn))
{
tree t;
t = build_reference_type (const_type_info_type_node);
t = build_function_type (t, void_list_node);
fn = push_throw_library_fn (fn, t);
}
return build_cxx_call (fn, NULL_TREE);
}
static tree
build_dynamic_cast_1 (tree type, tree expr)
{
enum tree_code tc = TREE_CODE (type);
tree exprtype = TREE_TYPE (expr);
tree dcast_fn;
tree old_expr = expr;
const char *errstr = NULL;
/* T shall be a pointer or reference to a complete class type, or
`pointer to cv void''. */
switch (tc)
{
case POINTER_TYPE:
if (TREE_CODE (TREE_TYPE (type)) == VOID_TYPE)
break;
/* Fall through. */
case REFERENCE_TYPE:
if (! IS_AGGR_TYPE (TREE_TYPE (type)))
{
errstr = "target is not pointer or reference to class";
goto fail;
}
if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type))))
{
errstr = "target is not pointer or reference to complete type";
goto fail;
}
break;
default:
errstr = "target is not pointer or reference";
goto fail;
}
if (tc == POINTER_TYPE)
{
/* If T is a pointer type, v shall be an rvalue of a pointer to
complete class type, and the result is an rvalue of type T. */
if (TREE_CODE (exprtype) != POINTER_TYPE)
{
errstr = "source is not a pointer";
goto fail;
}
if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
{
errstr = "source is not a pointer to class";
goto fail;
}
if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
{
errstr = "source is a pointer to incomplete type";
goto fail;
}
}
else
{
/* Apply trivial conversion T -> T& for dereferenced ptrs. */
exprtype = build_reference_type (exprtype);
expr = convert_to_reference (exprtype, expr, CONV_IMPLICIT,
LOOKUP_NORMAL, NULL_TREE);
/* T is a reference type, v shall be an lvalue of a complete class
type, and the result is an lvalue of the type referred to by T. */
if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
{
errstr = "source is not of class type";
goto fail;
}
if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
{
errstr = "source is of incomplete class type";
goto fail;
}
}
/* The dynamic_cast operator shall not cast away constness. */
if (!at_least_as_qualified_p (TREE_TYPE (type),
TREE_TYPE (exprtype)))
{
errstr = "conversion casts away constness";
goto fail;
}
/* If *type is an unambiguous accessible base class of *exprtype,
convert statically. */
{
tree binfo;
binfo = lookup_base (TREE_TYPE (exprtype), TREE_TYPE (type),
ba_check, NULL);
if (binfo)
{
expr = build_base_path (PLUS_EXPR, convert_from_reference (expr),
binfo, 0);
if (TREE_CODE (exprtype) == POINTER_TYPE)
expr = non_lvalue (expr);
return expr;
}
}
/* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype)))
{
tree expr1;
/* if TYPE is `void *', return pointer to complete object. */
if (tc == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (type)))
{
/* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
if (TREE_CODE (expr) == ADDR_EXPR
&& TREE_CODE (TREE_OPERAND (expr, 0)) == VAR_DECL
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE)
return build1 (NOP_EXPR, type, expr);
/* Since expr is used twice below, save it. */
expr = save_expr (expr);
expr1 = build_headof (expr);
if (TREE_TYPE (expr1) != type)
expr1 = build1 (NOP_EXPR, type, expr1);
return ifnonnull (expr, expr1);
}
else
{
tree retval;
tree result, td2, td3, elems;
tree static_type, target_type, boff;
/* If we got here, we can't convert statically. Therefore,
dynamic_cast<D&>(b) (b an object) cannot succeed. */
if (tc == REFERENCE_TYPE)
{
if (TREE_CODE (old_expr) == VAR_DECL
&& TREE_CODE (TREE_TYPE (old_expr)) == RECORD_TYPE)
{
tree expr = throw_bad_cast ();
warning ("dynamic_cast of %q#D to %q#T can never succeed",
old_expr, type);
/* Bash it to the expected type. */
TREE_TYPE (expr) = type;
return expr;
}
}
/* Ditto for dynamic_cast<D*>(&b). */
else if (TREE_CODE (expr) == ADDR_EXPR)
{
tree op = TREE_OPERAND (expr, 0);
if (TREE_CODE (op) == VAR_DECL
&& TREE_CODE (TREE_TYPE (op)) == RECORD_TYPE)
{
warning ("dynamic_cast of %q#D to %q#T can never succeed",
op, type);
retval = build_int_cst (type, 0);
return retval;
}
}
target_type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
static_type = TYPE_MAIN_VARIANT (TREE_TYPE (exprtype));
td2 = get_tinfo_decl (target_type);
mark_used (td2);
td2 = build_unary_op (ADDR_EXPR, td2, 0);
td3 = get_tinfo_decl (static_type);
mark_used (td3);
td3 = build_unary_op (ADDR_EXPR, td3, 0);
/* Determine how T and V are related. */
boff = dcast_base_hint (static_type, target_type);
/* Since expr is used twice below, save it. */
expr = save_expr (expr);
expr1 = expr;
if (tc == REFERENCE_TYPE)
expr1 = build_unary_op (ADDR_EXPR, expr1, 0);
elems = tree_cons
(NULL_TREE, expr1, tree_cons
(NULL_TREE, td3, tree_cons
(NULL_TREE, td2, tree_cons
(NULL_TREE, boff, NULL_TREE))));
dcast_fn = dynamic_cast_node;
if (!dcast_fn)
{
tree tmp;
tree tinfo_ptr;
tree ns = abi_node;
const char *name;
push_nested_namespace (ns);
tinfo_ptr = xref_tag (class_type,
get_identifier ("__class_type_info"),
/* APPLE LOCAL 4184203 */
/*tag_scope=*/ts_global, false);
tinfo_ptr = build_pointer_type
(build_qualified_type
(tinfo_ptr, TYPE_QUAL_CONST));
name = "__dynamic_cast";
tmp = tree_cons
(NULL_TREE, const_ptr_type_node, tree_cons
(NULL_TREE, tinfo_ptr, tree_cons
(NULL_TREE, tinfo_ptr, tree_cons
(NULL_TREE, ptrdiff_type_node, void_list_node))));
tmp = build_function_type (ptr_type_node, tmp);
dcast_fn = build_library_fn_ptr (name, tmp);
DECL_IS_PURE (dcast_fn) = 1;
pop_nested_namespace (ns);
dynamic_cast_node = dcast_fn;
}
result = build_cxx_call (dcast_fn, elems);
if (tc == REFERENCE_TYPE)
{
tree bad = throw_bad_cast ();
result = save_expr (result);
return build3 (COND_EXPR, type, result, result, bad);
}
/* Now back to the type we want from a void*. */
result = cp_convert (type, result);
return ifnonnull (expr, result);
}
}
else
errstr = "source type is not polymorphic";
fail:
error ("cannot dynamic_cast %qE (of type %q#T) to type %q#T (%s)",
expr, exprtype, type, errstr);
return error_mark_node;
}
/* FN is a constructor or destructor, and there are FUNCTION_DECLs
cloned from it nearby. Instead of cloning this body, leave it
alone and create tiny one-call bodies for the cloned
FUNCTION_DECLs. These clones are sibcall candidates, and their
resulting code will be very thunk-esque. */
static void
thunk_body (tree clone, tree fn, tree clone_to_call)
{
tree bind, block, call, fn_parm, fn_parm_typelist;
int parmno, vtt_parmno;
tree clone_parm, parmlist;
for (vtt_parmno = -1, parmno = 0, fn_parm = DECL_ARGUMENTS (fn);
fn_parm;
++parmno, fn_parm = TREE_CHAIN (fn_parm))
{
if (DECL_ARTIFICIAL (fn_parm) && DECL_NAME (fn_parm) == vtt_parm_identifier)
{
vtt_parmno = parmno; /* Compensate for removed in_charge parameter. */
break;
}
}
/* Currently, we are not supposed to have a vtt argument. */
gcc_assert(vtt_parmno == -1);
/* Walk parameter lists together, creating parameter list for call to original function. */
for (parmno = 0,
parmlist = NULL,
fn_parm = DECL_ARGUMENTS (fn),
fn_parm_typelist = TYPE_ARG_TYPES (TREE_TYPE (fn)),
clone_parm = DECL_ARGUMENTS (clone);
fn_parm;
++parmno,
fn_parm = TREE_CHAIN (fn_parm))
{
if (parmno == vtt_parmno && ! DECL_HAS_VTT_PARM_P (clone))
{
tree typed_null_pointer_node = copy_node (null_pointer_node);
gcc_assert (fn_parm_typelist);
/* Clobber actual parameter with formal parameter type. */
TREE_TYPE (typed_null_pointer_node) = TREE_VALUE (fn_parm_typelist);
parmlist = tree_cons (NULL, typed_null_pointer_node, parmlist);
}
else if (parmno == 1 && DECL_HAS_IN_CHARGE_PARM_P (fn))
{
/* Just skip it. */
}
/* Map other parameters to their equivalents in the cloned
function. */
else
{
gcc_assert (clone_parm);
DECL_ABSTRACT_ORIGIN (clone_parm) = NULL;
parmlist = tree_cons (NULL, clone_parm, parmlist);
clone_parm = TREE_CHAIN (clone_parm);
}
if (fn_parm_typelist)
fn_parm_typelist = TREE_CHAIN (fn_parm_typelist);
}
/* We built this list backwards; fix now. */
parmlist = nreverse (parmlist);
TREE_USED (clone_to_call) = 1;
call = build_cxx_call (clone_to_call, parmlist);
for (parmlist = TREE_OPERAND (call, 1); parmlist; parmlist = TREE_CHAIN (parmlist))
{
fn_parm = TREE_VALUE (parmlist);
/* Remove the EMPTY_CLASS_EXPR because it upsets estimate_num_insns(). */
if (TREE_CODE (fn_parm) == COMPOUND_EXPR)
{
gcc_assert (TREE_CODE (TREE_OPERAND (fn_parm, 1)) == EMPTY_CLASS_EXPR);
TREE_VALUE (parmlist) = TREE_OPERAND (fn_parm, 0);
}
}
block = make_node (BLOCK);
if (targetm.cxx.cdtor_returns_this ())
{
tree clone_result = DECL_RESULT (clone);
tree modify = build2 (MODIFY_EXPR, TREE_TYPE (clone_result), clone_result, call);
add_stmt (modify);
BLOCK_VARS (block) = clone_result;
}
else
{
add_stmt (call);
}
bind = c_build_bind_expr (block, cur_stmt_list);
DECL_SAVED_TREE (clone) = push_stmt_list ();
add_stmt (bind);
}
