/* Source-language-related definitions for GDB.
- Copyright (C) 1991-2019 Free Software Foundation, Inc.
+ Copyright (C) 1991-2020 Free Software Foundation, Inc.
Contributed by the Department of Computer Science at the State University
of New York at Buffalo.
struct type *bool_type_default;
};
+/* In a language (particularly C++) a function argument of an aggregate
+ type (i.e. class/struct/union) may be implicitly passed by reference
+ even though it is declared a call-by-value argument in the source.
+ The struct below puts together necessary information for GDB to be
+ able to detect and carry out pass-by-reference semantics for a
+ particular type. This type is referred as T in the inlined comments
+ below.
+
+ The default values of the fields are chosen to give correct semantics
+ for primitive types and for simple aggregate types, such as
+
+ class T {
+ int x;
+ }; */
+
+struct language_pass_by_ref_info
+{
+ /* True if an argument of type T can be passed to a function by value
+ (i.e. not through an implicit reference). False, otherwise. */
+ bool trivially_copyable = true;
+
+ /* True if a copy of a value of type T can be initialized by
+ memcpy'ing the value bit-by-bit. False, otherwise.
+ E.g. If T has a user-defined copy ctor, this should be false. */
+ bool trivially_copy_constructible = true;
+
+ /* True if a value of type T can be destructed simply by reclaiming
+ the memory area occupied by the value. False, otherwise.
+ E.g. If T has a user-defined destructor, this should be false. */
+ bool trivially_destructible = true;
+
+ /* True if it is allowed to create a copy of a value of type T.
+ False, otherwise.
+ E.g. If T has a deleted copy ctor, this should be false. */
+ bool copy_constructible = true;
+
+ /* True if a value of type T can be destructed. False, otherwise.
+ E.g. If T has a deleted destructor, this should be false. */
+ bool destructible = true;
+};
+
/* Structure tying together assorted information about a language. */
struct language_defn
struct ui_file *stream,
const struct value_print_options *options);
- /* Return non-zero if TYPE should be passed (and returned) by
- reference at the language level. */
- int (*la_pass_by_reference) (struct type *type);
+ /* Return information about whether TYPE should be passed
+ (and returned) by reference at the language level. */
+ struct language_pass_by_ref_info (*la_pass_by_reference)
+ (struct type *type);
/* Return an expression that can be used for a location
watchpoint. TYPE is a pointer type that points to the memory
struct ui_file *stream,
const struct value_print_options *options);
-/* Return non-zero if TYPE should be passed (and returned) by
- reference at the language level. */
-int language_pass_by_reference (struct type *type);
+/* Return information about whether TYPE should be passed
+ (and returned) by reference at the language level. */
+struct language_pass_by_ref_info language_pass_by_reference (struct type *type);
-/* Return zero; by default, types are passed by value at the language
- level. The target ABI may pass or return some structs by reference
- independent of this. */
-int default_pass_by_reference (struct type *type);
+/* Return a default struct that provides pass-by-reference information
+ about the given TYPE. Languages should update the default values
+ as appropriate. */
+struct language_pass_by_ref_info default_pass_by_reference (struct type *type);
/* The default implementation of la_print_typedef. */
void default_print_typedef (struct type *type, struct symbol *new_symbol,