* Makefile.in (arm-tdep.o, eval.o, target-descriptions.o)

	(xml-tdesc.o): Update.
	* xml-support.c: Add a comment.
	(gdb_xml_enums_boolean): New variable.
	(gdb_xml_parse_attr_enum): Use strcasecmp.
	* xml-support.h (gdb_xml_enums_boolean): Declare.
	* xml-tdesc.c (struct tdesc_parsing_data): Record current_feature,
	next_regnum, and current_union.
	(tdesc_start_feature, tdesc_start_reg, tdesc_start_union)
	(tdesc_end_union, tdesc_start_field, tdesc_start_vector)
	(field_attributes, union_children, reg_attributes, union_attributes)
	(vector_attributes, feature_attributes, feature_children): New.
	(target_children): Make static.  Add <feature>.
	(tdesc_elements): Make static.
	* target-descriptions.c (struct tdesc_reg, tdesc_reg_p, type_p)
	(struct tdesc_feature, tdesc_feature_p): New types.
	(struct target_desc): Add features member.
	(struct tdesc_arch_data, tdesc_data): New.
	(target_find_description): Clarify error message.  Warn about
	ignored register descriptions.
	(tdesc_has_registers, tdesc_find_feature, tdesc_feature_name)
	(tdesc_named_type, tdesc_data_init, tdesc_data_alloc)
	(tdesc_data_cleanup, tdesc_numbered_register)
	(tdesc_numbered_register_choices, tdesc_find_register)
	(tdesc_register_name, tdesc_register_type)
	(tdesc_remote_register_number, tdesc_register_reggroup_p)
	(set_tdesc_pseudo_register_name, set_tdesc_pseudo_register_type)
	(set_tdesc_pseudo_register_reggroup_p, tdesc_use_registers)
	(tdesc_free_reg, tdesc_create_reg, tdesc_free_feature)
	(tdesc_create_feature, tdesc_record_type): New.
	(free_target_description): Free features.
	(_initialize_target_descriptions): Initialize tdesc_data.
	* arch-utils.c (default_remote_register_number): New.
	* arch-utils.h (default_remote_register_number): New prototype.
	* target-descriptions.h (set_tdesc_pseudo_register_name)
	(set_tdesc_pseudo_register_type, set_tdesc_pseudo_register_reggroup_p)
	(tdesc_use_registers, tdesc_data_alloc, tdesc_data_cleanup)
	(tdesc_numbered_register, tdesc_numbered_register_choices)
	(tdesc_has_registers, tdesc_find_feature, tdesc_feature_name)
	(tdesc_named_type, tdesc_create_feature, tdesc_record_type)
	(tdesc_create_reg): Declare.
	* gdbarch.sh (remote_register_number): New entry.
	* gdbarch.c, gdbarch.h: Regenerate.
	* remote.c (init_remote_state): Use gdbarch_remote_register_number.
	* features/gdb-target.dtd: Add feature, reg, vector, union, and field.

	* arm-tdep.c (arm_register_aliases): New.
	(arm_register_name_strings): Rename to...
	(arm_register_names): ...this.  Make const.  Delete the old version.
	(current_option, arm_register_byte): Delete.
	(set_disassembly_style): Simplify.  Do not adjust arm_register_names.
	(value_of_arm_user_reg): New.
	(arm_gdbarch_init): Verify any described registers.  Call
	tdesc_use_registers.  Don't use arm_register_byte.  Create aliases
	for standard register names.
	(_initialize_arm_tdep): Do not adjust arm_register_names.
	* user-regs.c (struct user_reg): Add baton member.
	(append_user_reg, user_reg_add_builtin, user_regs_init)
	(user_reg_add, value_of_user_reg): Use a baton for user
	register functions.
	* std-regs.c: Update.
	* user-regs.h (user_reg_read_ftype, user_reg_add_builtin)
	(user_reg_add): Add baton argument.
	* NEWS: Mention target description register support.
	* features/arm-core.xml, features/arm-fpa.xml: New.
	* eval.c (evaluate_subexp_standard): Allow ptype $register
	when the program is not running.

	* gdb.texinfo (-target-disconnect): Use @smallexample.
	(Requirements): Add anchor for Expat.  Update description.
	(Target Descriptions): Mention Expat.
	(Target Description Format): Document new elements.  Use
	@smallexample.
	(Predefined Target Types, Standard Target Features): New sections.
	* doc/gdbint.texinfo (Target Descriptions): New section.

	* gdb.xml/single-reg.xml, gdb.xml/tdesc-regs.exp,
	gdb.xml/core-only.xml, gdb.xml/extra-regs.xml: New files.

1 files changed, 231 insertions, 2 deletions

diff --git a/gdb/xml-tdesc.c b/gdb/xml-tdesc.c
index bc7c6721f40..b45bb7ea5f4 100644
--- a/gdb/xml-tdesc.c
+++ b/gdb/xml-tdesc.c
@@ -23,6 +23,7 @@
    Boston, MA 02110-1301, USA.  */
 
 #include "defs.h"
+#include "gdbtypes.h"
 #include "target.h"
 #include "target-descriptions.h"
 #include "xml-support.h"
@@ -79,6 +80,16 @@ struct tdesc_parsing_data
 {
   /* The target description we are building.  */
   struct target_desc *tdesc;
+
+  /* The target feature we are currently parsing, or last parsed.  */
+  struct tdesc_feature *current_feature;
+
+  /* The register number to use for the next register we see, if
+     it does not have its own.  This starts at zero.  */
+  int next_regnum;
+
+  /* The union we are currently parsing, or last parsed.  */
+  struct type *current_union;
 };
 
 /* Handle the end of an <architecture> element and its value.  */
@@ -98,15 +109,233 @@ tdesc_end_arch (struct gdb_xml_parser *parser,
   set_tdesc_architecture (data->tdesc, arch);
 }
 
+/* Handle the start of a <feature> element.  */
+
+static void
+tdesc_start_feature (struct gdb_xml_parser *parser,
+		     const struct gdb_xml_element *element,
+		     void *user_data, VEC(gdb_xml_value_s) *attributes)
+{
+  struct tdesc_parsing_data *data = user_data;
+  char *name = VEC_index (gdb_xml_value_s, attributes, 0)->value;
+
+  data->current_feature = tdesc_create_feature (data->tdesc, name);
+}
+
+/* Handle the start of a <reg> element.  Fill in the optional
+   attributes and attach it to the containing feature.  */
+
+static void
+tdesc_start_reg (struct gdb_xml_parser *parser,
+		 const struct gdb_xml_element *element,
+		 void *user_data, VEC(gdb_xml_value_s) *attributes)
+{
+  struct tdesc_parsing_data *data = user_data;
+  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
+  int ix = 0, length;
+  char *name, *group, *type;
+  int bitsize, regnum, save_restore;
+
+  length = VEC_length (gdb_xml_value_s, attributes);
+
+  name = attrs[ix++].value;
+  bitsize = * (ULONGEST *) attrs[ix++].value;
+
+  if (ix < length && strcmp (attrs[ix].name, "regnum") == 0)
+    regnum = * (ULONGEST *) attrs[ix++].value;
+  else
+    regnum = data->next_regnum;
+
+  if (ix < length && strcmp (attrs[ix].name, "type") == 0)
+    type = attrs[ix++].value;
+  else
+    type = "int";
+
+  if (ix < length && strcmp (attrs[ix].name, "group") == 0)
+    group = attrs[ix++].value;
+  else
+    group = NULL;
+
+  if (ix < length && strcmp (attrs[ix].name, "save-restore") == 0)
+    save_restore = * (ULONGEST *) attrs[ix++].value;
+  else
+    save_restore = 1;
+
+  if (strcmp (type, "int") != 0
+      && strcmp (type, "float") != 0
+      && tdesc_named_type (data->current_feature, type) == NULL)
+    gdb_xml_error (parser, _("Register \"%s\" has unknown type \"%s\""),
+		   name, type);
+
+  tdesc_create_reg (data->current_feature, name, regnum, save_restore, group,
+		    bitsize, type);
+
+  data->next_regnum = regnum + 1;
+}
+
+/* Handle the start of a <union> element.  Initialize the type and
+   record it with the current feature.  */
+
+static void
+tdesc_start_union (struct gdb_xml_parser *parser,
+		   const struct gdb_xml_element *element,
+		   void *user_data, VEC(gdb_xml_value_s) *attributes)
+{
+  struct tdesc_parsing_data *data = user_data;
+  char *id = VEC_index (gdb_xml_value_s, attributes, 0)->value;
+  struct type *type;
+
+  type = init_composite_type (NULL, TYPE_CODE_UNION);
+  TYPE_NAME (type) = xstrdup (id);
+  tdesc_record_type (data->current_feature, type);
+  data->current_union = type;
+}
+
+/* Handle the end of a <union> element.  */
+
+static void
+tdesc_end_union (struct gdb_xml_parser *parser,
+		 const struct gdb_xml_element *element,
+		 void *user_data, const char *body_text)
+{
+  struct tdesc_parsing_data *data = user_data;
+  int i;
+
+  /* If any of the children of this union are vectors, flag the union
+     as a vector also.  This allows e.g. a union of two vector types
+     to show up automatically in "info vector".  */
+  for (i = 0; i < TYPE_NFIELDS (data->current_union); i++)
+    if (TYPE_VECTOR (TYPE_FIELD_TYPE (data->current_union, i)))
+      {
+        TYPE_FLAGS (data->current_union) |= TYPE_FLAG_VECTOR;
+        break;
+      }
+}
+
+/* Handle the start of a <field> element.  Attach the field to the
+   current union.  */
+
+static void
+tdesc_start_field (struct gdb_xml_parser *parser,
+		   const struct gdb_xml_element *element,
+		   void *user_data, VEC(gdb_xml_value_s) *attributes)
+{
+  struct tdesc_parsing_data *data = user_data;
+  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
+  struct type *type, *field_type;
+  char *field_name, *field_type_id;
+
+  field_name = attrs[0].value;
+  field_type_id = attrs[1].value;
+
+  field_type = tdesc_named_type (data->current_feature, field_type_id);
+  if (field_type == NULL)
+    gdb_xml_error (parser, _("Union field \"%s\" references undefined "
+			     "type \"%s\""),
+		   field_name, field_type_id);
+
+  append_composite_type_field (data->current_union, xstrdup (field_name),
+			       field_type);
+}
+
+/* Handle the start of a <vector> element.  Initialize the type and
+   record it with the current feature.  */
+
+static void
+tdesc_start_vector (struct gdb_xml_parser *parser,
+		    const struct gdb_xml_element *element,
+		    void *user_data, VEC(gdb_xml_value_s) *attributes)
+{
+  struct tdesc_parsing_data *data = user_data;
+  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
+  struct type *type, *field_type, *range_type;
+  char *id, *field_type_id;
+  int count;
+
+  id = attrs[0].value;
+  field_type_id = attrs[1].value;
+  count = * (ULONGEST *) attrs[2].value;
+
+  field_type = tdesc_named_type (data->current_feature, field_type_id);
+  if (field_type == NULL)
+    gdb_xml_error (parser, _("Vector \"%s\" references undefined type \"%s\""),
+		   id, field_type_id);
+
+  /* A vector is just an array plus a special flag.  */
+  range_type = create_range_type (NULL, builtin_type_int, 0, count - 1);
+  type = create_array_type (NULL, field_type, range_type);
+  TYPE_NAME (type) = xstrdup (id);
+
+  TYPE_FLAGS (type) |= TYPE_FLAG_VECTOR;
+
+  tdesc_record_type (data->current_feature, type);
+}
+
 /* The elements and attributes of an XML target description.  */
 
-const struct gdb_xml_element target_children[] = {
+static const struct gdb_xml_attribute field_attributes[] = {
+  { "name", GDB_XML_AF_NONE, NULL, NULL },
+  { "type", GDB_XML_AF_NONE, NULL, NULL },
+  { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_element union_children[] = {
+  { "field", field_attributes, NULL, GDB_XML_EF_REPEATABLE,
+    tdesc_start_field, NULL },
+  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_attribute reg_attributes[] = {
+  { "name", GDB_XML_AF_NONE, NULL, NULL },
+  { "bitsize", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+  { "regnum", GDB_XML_AF_OPTIONAL, gdb_xml_parse_attr_ulongest, NULL },
+  { "type", GDB_XML_AF_OPTIONAL, NULL, NULL },
+  { "group", GDB_XML_AF_OPTIONAL, NULL, NULL },
+  { "save-restore", GDB_XML_AF_OPTIONAL,
+    gdb_xml_parse_attr_enum, gdb_xml_enums_boolean },
+  { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_attribute union_attributes[] = {
+  { "id", GDB_XML_AF_NONE, NULL, NULL },
+  { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_attribute vector_attributes[] = {
+  { "id", GDB_XML_AF_NONE, NULL, NULL },
+  { "type", GDB_XML_AF_NONE, NULL, NULL },
+  { "count", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+  { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_attribute feature_attributes[] = {
+  { "name", GDB_XML_AF_NONE, NULL, NULL },
+  { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_element feature_children[] = {
+  { "reg", reg_attributes, NULL,
+    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
+    tdesc_start_reg, NULL },
+  { "union", union_attributes, union_children,
+    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
+    tdesc_start_union, tdesc_end_union },
+  { "vector", vector_attributes, NULL,
+    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
+    tdesc_start_vector, NULL },
+  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_element target_children[] = {
   { "architecture", NULL, NULL, GDB_XML_EF_OPTIONAL,
     NULL, tdesc_end_arch },
+  { "feature", feature_attributes, feature_children,
+    GDB_XML_EF_OPTIONAL | GDB_XML_EF_REPEATABLE,
+    tdesc_start_feature, NULL },
   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 };
 
-const struct gdb_xml_element tdesc_elements[] = {
+static const struct gdb_xml_element tdesc_elements[] = {
   { "target", NULL, target_children, GDB_XML_EF_NONE,
     NULL, NULL },
   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }