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); }
static void initialize_handler_parm (tree decl, tree exp) { tree init; tree init_type; /* Make sure we mark the catch param as used, otherwise we'll get a warning about an unused ((anonymous)). */ TREE_USED (decl) = 1; /* Figure out the type that the initializer is. Pointers are returned adjusted by value from __cxa_begin_catch. Others are returned by reference. */ init_type = TREE_TYPE (decl); if (!POINTER_TYPE_P (init_type)) init_type = build_reference_type (init_type); choose_personality_routine (decl_is_java_type (init_type, 0) ? lang_java : lang_cplusplus); /* Since pointers are passed by value, initialize a reference to pointer catch parm with the address of the temporary. */ if (TREE_CODE (init_type) == REFERENCE_TYPE && TYPE_PTR_P (TREE_TYPE (init_type))) exp = cp_build_unary_op (ADDR_EXPR, exp, 1, tf_warning_or_error); exp = ocp_convert (init_type, exp, CONV_IMPLICIT|CONV_FORCE_TEMP, 0); init = convert_from_reference (exp); /* If the constructor for the catch parm exits via an exception, we must call terminate. See eh23.C. */ if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl))) { /* Generate the copy constructor call directly so we can wrap it. See also expand_default_init. */ init = ocp_convert (TREE_TYPE (decl), init, CONV_IMPLICIT|CONV_FORCE_TEMP, 0); /* Force cleanups now to avoid nesting problems with the MUST_NOT_THROW_EXPR. */ init = fold_build_cleanup_point_expr (TREE_TYPE (init), init); init = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (init), init); } decl = pushdecl (decl); start_decl_1 (decl, true); cp_finish_decl (decl, init, /*init_const_expr_p=*/false, NULL_TREE, LOOKUP_ONLYCONVERTING|DIRECT_BIND); }
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; }