ChangeLog:

	* features/gdb-target.dtd (target): Accept optional
	<compatible> elements.
	(compatible): Define element.

	* target-descriptions.h (tdesc_compatible_p): New.
	(tdesc_add_compatible): New.
	* target-descriptions.c (arch_p): New VEC_P type.
	(struct target_desc): New member compatible.
	(free_target_description): Handle it.
	(maint_print_c_tdesc_cmd): Likewise.
	(tdesc_compatible_p): New function.
	(tdesc_add_compatible): New function.

	* xml-tdesc.c (tdesc_end_compatible): New function.
	(target_children): Handle <compatible> element.

	* arch-utils.c (choose_architecture_for_target): Accept target
	description instead of BFD architecture as input.  Query target
	description for compatible architectures.
	(gdbarch_info_fill): Update call.

	* NEWS: Mention <compatible> element of target descriptions.

doc/ChangeLog:

	* gdb.texinfo (Target Descriptions): Document <compatible> element.

1 files changed, 8 insertions, 0 deletions

diff --git a/gdb/target-descriptions.h b/gdb/target-descriptions.h
index 899f119..3880260 100644
--- a/gdb/target-descriptions.h
+++ b/gdb/target-descriptions.h
@@ -134,6 +134,12 @@ const struct bfd_arch_info *tdesc_architecture
 
 enum gdb_osabi tdesc_osabi (const struct target_desc *);
 
+/* Return non-zero if this target description is compatible
+   with the given BFD architecture.  */
+
+int tdesc_compatible_p (const struct target_desc *,
+			const struct bfd_arch_info *);
+
 /* Return the string value of a property named KEY, or NULL if the
    property was not specified.  */
 
@@ -186,6 +192,8 @@ void set_tdesc_architecture (struct target_desc *,
 void set_tdesc_osabi (struct target_desc *, enum gdb_osabi osabi);
 void set_tdesc_property (struct target_desc *,
 			 const char *key, const char *value);
+void tdesc_add_compatible (struct target_desc *,
+			   const struct bfd_arch_info *);
 
 struct tdesc_feature *tdesc_create_feature (struct target_desc *tdesc,
 					    const char *name);