diff options
Diffstat (limited to 'gcc/ada/gcc-interface/decl.c')
| -rw-r--r-- | gcc/ada/gcc-interface/decl.c | 107 |
1 files changed, 85 insertions, 22 deletions
diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c index b0bf586..bc0804a 100644 --- a/gcc/ada/gcc-interface/decl.c +++ b/gcc/ada/gcc-interface/decl.c @@ -145,7 +145,7 @@ static void prepend_one_attribute_to (struct attrib **, enum attr_type, tree, tree, Node_Id); static void prepend_attributes (Entity_Id, struct attrib **); static tree elaborate_expression (Node_Id, Entity_Id, tree, bool, bool, bool); -static bool is_variable_size (tree); +static bool type_has_variable_size (tree); static tree elaborate_expression_1 (tree, Entity_Id, tree, bool, bool); static tree elaborate_expression_2 (tree, Entity_Id, tree, bool, bool, unsigned int); @@ -6848,7 +6848,7 @@ adjust_packed (tree field_type, tree record_type, int packed) because we cannot create temporaries of non-fixed size in case we need to take the address of the field. See addressable_p and the notes on the addressability issues for further details. */ - if (is_variable_size (field_type)) + if (type_has_variable_size (field_type)) return 0; /* If the alignment of the record is specified and the field type @@ -7123,6 +7123,7 @@ gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed, = create_field_decl (gnu_field_id, gnu_field_type, gnu_record_type, gnu_size, gnu_pos, packed, Is_Aliased (gnat_field)); Sloc_to_locus (Sloc (gnat_field), &DECL_SOURCE_LOCATION (gnu_field)); + DECL_ALIASED_P (gnu_field) = Is_Aliased (gnat_field); TREE_THIS_VOLATILE (gnu_field) = TREE_SIDE_EFFECTS (gnu_field) = is_volatile; if (Ekind (gnat_field) == E_Discriminant) @@ -7136,7 +7137,7 @@ gnat_to_gnu_field (Entity_Id gnat_field, tree gnu_record_type, int packed, field of variable size or is a record that has a field such a field. */ static bool -is_variable_size (tree type) +type_has_variable_size (tree type) { tree field; @@ -7151,12 +7152,68 @@ is_variable_size (tree type) return false; for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) - if (is_variable_size (TREE_TYPE (field))) + if (type_has_variable_size (TREE_TYPE (field))) return true; return false; } +/* Return true if FIELD is an artificial field. */ + +static bool +field_is_artificial (tree field) +{ + /* These fields are generated by the front-end proper. */ + if (IDENTIFIER_POINTER (DECL_NAME (field)) [0] == '_') + return true; + + /* These fields are generated by gigi. */ + if (DECL_INTERNAL_P (field)) + return true; + + return false; +} + +/* Return true if FIELD is a non-artificial aliased field. */ + +static bool +field_is_aliased (tree field) +{ + if (field_is_artificial (field)) + return false; + + return DECL_ALIASED_P (field); +} + +/* Return true if FIELD is a non-artificial field with self-referential + size. */ + +static bool +field_has_self_size (tree field) +{ + if (field_is_artificial (field)) + return false; + + if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST) + return false; + + return CONTAINS_PLACEHOLDER_P (TYPE_SIZE (TREE_TYPE (field))); +} + +/* Return true if FIELD is a non-artificial field with variable size. */ + +static bool +field_has_variable_size (tree field) +{ + if (field_is_artificial (field)) + return false; + + if (DECL_SIZE (field) && TREE_CODE (DECL_SIZE (field)) == INTEGER_CST) + return false; + + return TREE_CODE (TYPE_SIZE (TREE_TYPE (field))) != INTEGER_CST; +} + /* qsort comparer for the bit positions of two record components. */ static int @@ -7219,6 +7276,8 @@ components_to_record (tree gnu_record_type, Node_Id gnat_component_list, { bool all_rep_and_size = all_rep && TYPE_SIZE (gnu_record_type); bool layout_with_rep = false; + bool has_self_field = false; + bool has_aliased_after_self_field = false; Node_Id component_decl, variant_part; tree gnu_field, gnu_next, gnu_last; tree gnu_rep_part = NULL_TREE; @@ -7270,6 +7329,12 @@ components_to_record (tree gnu_record_type, Node_Id gnat_component_list, gnu_field_list = gnu_field; if (!gnu_last) gnu_last = gnu_field; + + /* And record information for the final layout. */ + if (field_has_self_size (gnu_field)) + has_self_field = true; + else if (has_self_field && field_is_aliased (gnu_field)) + has_aliased_after_self_field = true; } } @@ -7505,25 +7570,17 @@ components_to_record (tree gnu_record_type, Node_Id gnat_component_list, continue; } - /* Reorder non-internal fields with non-fixed size. */ - if (reorder - && !DECL_INTERNAL_P (gnu_field) - && !(DECL_SIZE (gnu_field) - && TREE_CODE (DECL_SIZE (gnu_field)) == INTEGER_CST)) + if ((reorder || has_aliased_after_self_field) + && field_has_self_size (gnu_field)) { - tree type_size = TYPE_SIZE (TREE_TYPE (gnu_field)); - - if (CONTAINS_PLACEHOLDER_P (type_size)) - { - MOVE_FROM_FIELD_LIST_TO (gnu_self_list); - continue; - } + MOVE_FROM_FIELD_LIST_TO (gnu_self_list); + continue; + } - if (TREE_CODE (type_size) != INTEGER_CST) - { - MOVE_FROM_FIELD_LIST_TO (gnu_var_list); - continue; - } + if (reorder && field_has_variable_size (gnu_field)) + { + MOVE_FROM_FIELD_LIST_TO (gnu_var_list); + continue; } gnu_last = gnu_field; @@ -7531,7 +7588,7 @@ components_to_record (tree gnu_record_type, Node_Id gnat_component_list, #undef MOVE_FROM_FIELD_LIST_TO - /* If permitted, we reorder the components as follows: + /* If permitted, we reorder the fields as follows: 1) all fixed length fields, 2) all fields whose length doesn't depend on discriminants, @@ -7544,6 +7601,12 @@ components_to_record (tree gnu_record_type, Node_Id gnat_component_list, = chainon (nreverse (gnu_self_list), chainon (nreverse (gnu_var_list), gnu_field_list)); + /* Otherwise, if there is an aliased field placed after a field whose length + depends on discriminants, we put all the fields of the latter sort, last. + We need to do this in case an object of this record type is mutable. */ + else if (has_aliased_after_self_field) + gnu_field_list = chainon (nreverse (gnu_self_list), gnu_field_list); + /* If P_REP_LIST is nonzero, this means that we are asked to move the fields in our REP list to the previous level because this level needs them in order to do a correct layout, i.e. avoid having overlapping fields. */ |