XML feature description support.

	* NEWS: Mention target descriptions, "set tdesc filename",
	"unset tdesc filename", "show tdesc filename", and
	qXfer:features:read.
	* arch-utils.c (choose_architecture_for_target): New function.
	(gdbarch_info_fill): Call it.
	* target-descriptions.c (struct property): Make members non-const.
	(struct target_desc): Add arch member.
	(target_description_filename): New variable.
	(target_find_description): Try via XML first.
	(tdesc_architecture): New.
	(free_target_description, make_cleanup_free_target_description): New.
	(set_tdesc_property): Call xstrdup.
	(set_tdesc_architecture, tdesc_set_cmdlist, tdesc_show_cmdlist)
	(tdesc_unset_cmdlist, unset_tdesc_cmd, unset_tdesc_filename_cmd)
	(set_tdesc_cmd, show_tdesc_cmd, set_tdesc_filename_cmd)
	(show_tdesc_filename_cmd, _initialize_target_descriptions): New.
	* target-descriptions.h (tdesc_architecture)
	(make_cleanup_free_target_description, set_tdesc_architecture): New
	prototypes.
	* Makefile.in (SFILES): Add xml-tdesc.c.
	(COMMON_OBS): Add xml-tdesc.o.
	(target-descriptions.o): Update.
	(xml-tdesc.o): New rule.
	* xml-tdesc.c, xml-tdesc.h: New files.
	* remote.c (PACKET_qXfer_features): New enum.
	(remote_protocol_features): Add qXfer:features:read.
	(remote_xfer_partial): Handle TARGET_OBJECT_AVAILABLE_FEATURES.
	(_initialize_remote): Register qXfer:features:read.
	* target.h (enum target_object): Add TARGET_OBJECT_AVAILABLE_FEATURES.
	* features/gdb-target.dtd: New file.

	* linux-i386-low.c (the_low_target): Set arch_string.
	* linux-x86-64-low.c (the_low_target): Likewise.
	* linux-low.c (linux_arch_string): New.
	(linux_target_ops): Add it.
	* linux-low.h (struct linux_target_ops): Add arch_string.
	* server.c (write_qxfer_response): Use const void * for DATA.
	(get_features_xml): New.
	(handle_query): Handle qXfer:features:read.  Report it for qSupported.
	* target.h (struct target_ops): Add arch_string method.

	* gdb.texinfo (Target Descriptions): New section.
	(General Query Packets): Add QPassSignals anchor.  Mention
	qXfer:features:read under qSupported.  Expand mentions of
	qXfer:memory-map:read and QPassSignals.  Document
	qXfer:features:read.

1 files changed, 6 insertions, 3 deletions

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 1de5f4c26fd..9567fac4580 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -563,7 +563,7 @@ SFILES = ada-exp.y ada-lang.c ada-typeprint.c ada-valprint.c  \
 	user-regs.c \
 	valarith.c valops.c valprint.c value.c varobj.c vec.c \
 	wrapper.c \
-	xml-support.c
+	xml-tdesc.c xml-support.c
 
 LINTFILES = $(SFILES) $(YYFILES) $(CONFIG_SRCS) init.c
 
@@ -972,7 +972,7 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \
 	tramp-frame.o \
 	solib.o solib-null.o \
 	prologue-value.o memory-map.o xml-support.o \
-	target-descriptions.o target-memory.o
+	target-descriptions.o target-memory.o xml-tdesc.o
 
 TSOBS = inflow.o
 
@@ -2776,7 +2776,8 @@ target.o: target.c $(defs_h) $(gdb_string_h) $(target_h) $(gdbcmd_h) \
 	$(gdb_wait_h) $(dcache_h) $(regcache_h) $(gdb_assert_h) $(gdbcore_h) \
 	$(exceptions_h) $(target_descriptions_h)
 target-descriptions.o: target-descriptions.c $(defs_h) $(arch_utils_h) \
-	$(target_h) $(target_descriptions_h) $(vec_h) $(gdb_assert_h)
+	$(target_h) $(target_descriptions_h) $(vec_h) $(xml_tdesc_h) \
+	$(gdbcmd_h) $(gdb_assert_h)
 target-memory.o: target-memory.c $(defs_h) $(vec_h) $(target_h) \
 	$(memory_map_h) $(gdb_assert_h)
 thread.o: thread.c $(defs_h) $(symtab_h) $(frame_h) $(inferior_h) \
@@ -2874,6 +2875,8 @@ xcoffread.o: xcoffread.c $(defs_h) $(bfd_h) $(gdb_string_h) $(gdb_stat_h) \
 	$(complaints_h) $(gdb_stabs_h) $(aout_stab_gnu_h)
 xcoffsolib.o: xcoffsolib.c $(defs_h) $(bfd_h) $(xcoffsolib_h) $(inferior_h) \
 	$(gdbcmd_h) $(symfile_h) $(frame_h) $(gdb_regex_h)
+xml-tdesc.o: xml-tdesc.c $(defs_h) $(target_h) $(target_descriptions_h) \
+	$(xml_tdesc_h) $(xml_support_h) $(gdb_assert_h)
 xml-support.o: xml-support.c $(defs_h) $(xml_support_h) $(exceptions_h) \
 	$(gdbcmd_h) $(gdb_string_h) $(gdb_expat_h) $(safe_ctype_h)
 xstormy16-tdep.o: xstormy16-tdep.c $(defs_h) $(frame_h) $(frame_base_h) \