/* Target description support for GDB.
- Copyright (C) 2006
- Free Software Foundation, Inc.
+ Copyright (C) 2006, 2007 Free Software Foundation, Inc.
Contributed by CodeSourcery.
#include "defs.h"
#include "arch-utils.h"
+#include "gdbcmd.h"
+#include "gdbtypes.h"
+#include "reggroups.h"
#include "target.h"
#include "target-descriptions.h"
#include "vec.h"
+#include "xml-support.h"
+#include "xml-tdesc.h"
#include "gdb_assert.h"
+#include "gdb_obstack.h"
+#include "hashtab.h"
/* Types. */
typedef struct property
{
- const char *key;
- const char *value;
+ char *key;
+ char *value;
} property_s;
DEF_VEC_O(property_s);
+/* An individual register from a target description. */
+
+typedef struct tdesc_reg
+{
+ /* The name of this register. In standard features, it may be
+ recognized by the architecture support code, or it may be purely
+ for the user. */
+ char *name;
+
+ /* The register number used by this target to refer to this
+ register. This is used for remote p/P packets and to determine
+ the ordering of registers in the remote g/G packets. */
+ long target_regnum;
+
+ /* If this flag is set, GDB should save and restore this register
+ around calls to an inferior function. */
+ int save_restore;
+
+ /* The name of the register group containing this register, or NULL
+ if the group should be automatically determined from the
+ register's type. If this is "general", "float", or "vector", the
+ corresponding "info" command should display this register's
+ value. It can be an arbitrary string, but should be limited to
+ alphanumeric characters and internal hyphens. Currently other
+ strings are ignored (treated as NULL). */
+ char *group;
+
+ /* The size of the register, in bits. */
+ int bitsize;
+
+ /* The type of the register. This string corresponds to either
+ a named type from the target description or a predefined
+ type from GDB. */
+ char *type;
+
+ /* The target-described type corresponding to TYPE, if found. */
+ struct type *gdb_type;
+} *tdesc_reg_p;
+DEF_VEC_P(tdesc_reg_p);
+
+/* A named type from a target description. */
+typedef struct type *type_p;
+DEF_VEC_P(type_p);
+
+/* A feature from a target description. Each feature is a collection
+ of other elements, e.g. registers and types. */
+
+typedef struct tdesc_feature
+{
+ /* The name of this feature. It may be recognized by the architecture
+ support code. */
+ char *name;
+
+ /* The registers associated with this feature. */
+ VEC(tdesc_reg_p) *registers;
+
+ /* The types associated with this feature. */
+ VEC(type_p) *types;
+} *tdesc_feature_p;
+DEF_VEC_P(tdesc_feature_p);
+
+/* A target description. */
+
struct target_desc
{
+ /* The architecture reported by the target, if any. */
+ const struct bfd_arch_info *arch;
+
/* Any architecture-specific properties specified by the target. */
VEC(property_s) *properties;
+
+ /* The features associated with this target. */
+ VEC(tdesc_feature_p) *features;
+};
+
+/* Per-architecture data associated with a target description. The
+ target description may be shared by multiple architectures, but
+ this data is private to one gdbarch. */
+
+struct tdesc_arch_data
+{
+ /* A list of registers, indexed by GDB's internal register number.
+ During initialization of the gdbarch this list is used to store
+ registers which the architecture assigns a fixed register number.
+ Registers which are NULL in this array, or off the end, are
+ treated as zero-sized and nameless (i.e. placeholders in the
+ numbering). */
+ VEC(tdesc_reg_p) *registers;
+
+ /* Functions which report the register name, type, and reggroups for
+ pseudo-registers. */
+ gdbarch_register_name_ftype *pseudo_register_name;
+ gdbarch_register_type_ftype *pseudo_register_type;
+ gdbarch_register_reggroup_p_ftype *pseudo_register_reggroup_p;
};
/* Global state. These variables are associated with the current
static const struct target_desc *current_target_desc;
+/* Other global variables. */
+
+/* The filename to read a target description from. */
+
+static char *target_description_filename;
+
+/* A handle for architecture-specific data associated with the
+ target description (see struct tdesc_arch_data). */
+
+static struct gdbarch_data *tdesc_data;
+
/* Fetch the current target's description, and switch the current
architecture to one which incorporates that description. */
disconnected from the previous target. */
gdb_assert (gdbarch_target_desc (current_gdbarch) == NULL);
- current_target_desc = target_read_description (¤t_target);
+ /* First try to fetch an XML description from the user-specified
+ file. */
+ current_target_desc = NULL;
+ if (target_description_filename != NULL
+ && *target_description_filename != '\0')
+ current_target_desc
+ = file_read_description_xml (target_description_filename);
+
+ /* Next try to read the description from the current target using
+ target objects. */
+ if (current_target_desc == NULL)
+ current_target_desc = target_read_description_xml (¤t_target);
+
+ /* If that failed try a target-specific hook. */
+ if (current_target_desc == NULL)
+ current_target_desc = target_read_description (¤t_target);
/* If a non-NULL description was returned, then update the current
architecture. */
gdbarch_info_init (&info);
info.target_desc = current_target_desc;
if (!gdbarch_update_p (info))
- warning (_("Could not use target-supplied description"));
+ warning (_("Architecture rejected target-supplied description"));
+ else
+ {
+ struct tdesc_arch_data *data;
+
+ data = gdbarch_data (current_gdbarch, tdesc_data);
+ if (tdesc_has_registers (current_target_desc)
+ && data->registers == NULL)
+ warning (_("Target-supplied registers are not supported "
+ "by the current architecture"));
+ }
}
/* Now that we know this description is usable, record that we
return NULL;
}
+\f
+
+/* Direct accessors for target descriptions. */
/* Return the string value of a property named KEY, or NULL if the
property was not specified. */
return NULL;
}
+/* Return the BFD architecture associated with this target
+ description, or NULL if no architecture was specified. */
+
+const struct bfd_arch_info *
+tdesc_architecture (const struct target_desc *target_desc)
+{
+ return target_desc->arch;
+}
+\f
+
+/* Return 1 if this target description includes any registers. */
+
+int
+tdesc_has_registers (const struct target_desc *target_desc)
+{
+ int ix;
+ struct tdesc_feature *feature;
+
+ if (target_desc == NULL)
+ return 0;
+
+ for (ix = 0;
+ VEC_iterate (tdesc_feature_p, target_desc->features, ix, feature);
+ ix++)
+ if (! VEC_empty (tdesc_reg_p, feature->registers))
+ return 1;
+
+ return 0;
+}
+
+/* Return the feature with the given name, if present, or NULL if
+ the named feature is not found. */
+
+const struct tdesc_feature *
+tdesc_find_feature (const struct target_desc *target_desc,
+ const char *name)
+{
+ int ix;
+ struct tdesc_feature *feature;
+
+ for (ix = 0;
+ VEC_iterate (tdesc_feature_p, target_desc->features, ix, feature);
+ ix++)
+ if (strcmp (feature->name, name) == 0)
+ return feature;
+
+ return NULL;
+}
+
+/* Return the name of FEATURE. */
+
+const char *
+tdesc_feature_name (const struct tdesc_feature *feature)
+{
+ return feature->name;
+}
+
+/* Return the type associated with ID in the context of FEATURE, or
+ NULL if none. */
+
+struct type *
+tdesc_named_type (const struct tdesc_feature *feature, const char *id)
+{
+ int ix;
+ struct type *gdb_type;
+
+ /* First try target-defined types. */
+ for (ix = 0; VEC_iterate (type_p, feature->types, ix, gdb_type); ix++)
+ if (strcmp (TYPE_NAME (gdb_type), id) == 0)
+ return gdb_type;
+
+ /* Next try some predefined types. Note that none of these types
+ depend on the current architecture; some of the builtin_type_foo
+ variables are swapped based on the architecture. */
+ if (strcmp (id, "int8") == 0)
+ return builtin_type_int8;
+
+ if (strcmp (id, "int16") == 0)
+ return builtin_type_int16;
+
+ if (strcmp (id, "int32") == 0)
+ return builtin_type_int32;
+
+ if (strcmp (id, "int64") == 0)
+ return builtin_type_int64;
+
+ if (strcmp (id, "uint8") == 0)
+ return builtin_type_uint8;
+
+ if (strcmp (id, "uint16") == 0)
+ return builtin_type_uint16;
+
+ if (strcmp (id, "uint32") == 0)
+ return builtin_type_uint32;
+
+ if (strcmp (id, "uint64") == 0)
+ return builtin_type_uint64;
+
+ if (strcmp (id, "code_ptr") == 0)
+ return builtin_type_void_func_ptr;
+
+ if (strcmp (id, "data_ptr") == 0)
+ return builtin_type_void_data_ptr;
+
+ if (strcmp (id, "arm_fpa_ext") == 0)
+ return builtin_type_arm_ext;
+
+ return NULL;
+}
+\f
+
+/* Support for registers from target descriptions. */
+
+/* Construct the per-gdbarch data. */
+
+static void *
+tdesc_data_init (struct obstack *obstack)
+{
+ struct tdesc_arch_data *data;
+
+ data = OBSTACK_ZALLOC (obstack, struct tdesc_arch_data);
+ return data;
+}
+
+/* Similar, but for the temporary copy used during architecture
+ initialization. */
+
+struct tdesc_arch_data *
+tdesc_data_alloc (void)
+{
+ return XZALLOC (struct tdesc_arch_data);
+}
+
+/* Free something allocated by tdesc_data_alloc, if it is not going
+ to be used (for instance if it was unsuitable for the
+ architecture). */
+
+void
+tdesc_data_cleanup (void *data_untyped)
+{
+ struct tdesc_arch_data *data = data_untyped;
+
+ VEC_free (tdesc_reg_p, data->registers);
+ xfree (data);
+}
+
+/* Search FEATURE for a register named NAME. */
+
+int
+tdesc_numbered_register (const struct tdesc_feature *feature,
+ struct tdesc_arch_data *data,
+ int regno, const char *name)
+{
+ int ixr;
+ struct tdesc_reg *reg;
+
+ for (ixr = 0;
+ VEC_iterate (tdesc_reg_p, feature->registers, ixr, reg);
+ ixr++)
+ if (strcasecmp (reg->name, name) == 0)
+ {
+ /* Make sure the vector includes a REGNO'th element. */
+ while (regno >= VEC_length (tdesc_reg_p, data->registers))
+ VEC_safe_push (tdesc_reg_p, data->registers, NULL);
+ VEC_replace (tdesc_reg_p, data->registers, regno, reg);
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Search FEATURE for a register whose name is in NAMES. */
+
+int
+tdesc_numbered_register_choices (const struct tdesc_feature *feature,
+ struct tdesc_arch_data *data,
+ int regno, const char *const names[])
+{
+ int i;
+
+ for (i = 0; names[i] != NULL; i++)
+ if (tdesc_numbered_register (feature, data, regno, names[i]))
+ return 1;
+
+ return 0;
+}
+
+/* Look up a register by its GDB internal register number. */
+
+static struct tdesc_reg *
+tdesc_find_register (struct gdbarch *gdbarch, int regno)
+{
+ struct tdesc_reg *reg;
+ struct tdesc_arch_data *data;
+
+ data = gdbarch_data (gdbarch, tdesc_data);
+ if (regno < VEC_length (tdesc_reg_p, data->registers))
+ return VEC_index (tdesc_reg_p, data->registers, regno);
+ else
+ return NULL;
+}
+
+static const char *
+tdesc_register_name (int regno)
+{
+ struct tdesc_reg *reg = tdesc_find_register (current_gdbarch, regno);
+ int num_regs = gdbarch_num_regs (current_gdbarch);
+ int num_pseudo_regs = gdbarch_num_pseudo_regs (current_gdbarch);
+
+ if (reg != NULL)
+ return reg->name;
+
+ if (regno >= num_regs && regno < num_regs + num_pseudo_regs)
+ {
+ struct tdesc_arch_data *data = gdbarch_data (current_gdbarch,
+ tdesc_data);
+ gdb_assert (data->pseudo_register_name != NULL);
+ return data->pseudo_register_name (regno);
+ }
+
+ return "";
+}
+
+static struct type *
+tdesc_register_type (struct gdbarch *gdbarch, int regno)
+{
+ struct tdesc_reg *reg = tdesc_find_register (gdbarch, regno);
+ int num_regs = gdbarch_num_regs (gdbarch);
+ int num_pseudo_regs = gdbarch_num_pseudo_regs (gdbarch);
+
+ if (reg == NULL && regno >= num_regs && regno < num_regs + num_pseudo_regs)
+ {
+ struct tdesc_arch_data *data = gdbarch_data (gdbarch, tdesc_data);
+ gdb_assert (data->pseudo_register_type != NULL);
+ return data->pseudo_register_type (gdbarch, regno);
+ }
+
+ if (reg == NULL)
+ /* Return "int0_t", since "void" has a misleading size of one. */
+ return builtin_type_int0;
+
+ /* First check for a predefined or target defined type. */
+ if (reg->gdb_type)
+ return reg->gdb_type;
+
+ /* Next try size-sensitive type shortcuts. */
+ if (strcmp (reg->type, "float") == 0)
+ {
+ if (reg->bitsize == gdbarch_float_bit (gdbarch))
+ return builtin_type_float;
+ else if (reg->bitsize == gdbarch_double_bit (gdbarch))
+ return builtin_type_double;
+ else if (reg->bitsize == gdbarch_long_double_bit (gdbarch))
+ return builtin_type_long_double;
+ }
+ else if (strcmp (reg->type, "int") == 0)
+ {
+ if (reg->bitsize == gdbarch_long_bit (gdbarch))
+ return builtin_type_long;
+ else if (reg->bitsize == TARGET_CHAR_BIT)
+ return builtin_type_char;
+ else if (reg->bitsize == gdbarch_short_bit (gdbarch))
+ return builtin_type_short;
+ else if (reg->bitsize == gdbarch_int_bit (gdbarch))
+ return builtin_type_int;
+ else if (reg->bitsize == gdbarch_long_long_bit (gdbarch))
+ return builtin_type_long_long;
+ else if (reg->bitsize == gdbarch_ptr_bit (gdbarch))
+ /* A bit desperate by this point... */
+ return builtin_type_void_data_ptr;
+ }
+ else
+ internal_error (__FILE__, __LINE__,
+ "Register \"%s\" has an unknown type \"%s\"",
+ reg->name, reg->type);
+
+ warning (_("Register \"%s\" has an unsupported size (%d bits)"),
+ reg->name, reg->bitsize);
+ return builtin_type_long;
+}
+
+static int
+tdesc_remote_register_number (struct gdbarch *gdbarch, int regno)
+{
+ struct tdesc_reg *reg = tdesc_find_register (gdbarch, regno);
+
+ if (reg != NULL)
+ return reg->target_regnum;
+ else
+ return -1;
+}
+
+/* Check whether REGNUM is a member of REGGROUP. Registers from the
+ target description may be classified as general, float, or vector.
+ Registers with no group specified go to the default reggroup
+ function and are handled by type.
+
+ Arbitrary strings (other than "general", "float", and "vector")
+ from the description are not used; they cause the register to be
+ displayed in "info all-registers" but excluded from "info
+ registers" et al. The names of containing features are also not
+ used. This might be extended to display registers in some more
+ useful groupings.
+
+ The save-restore flag is also implemented here. */
+
+static int
+tdesc_register_reggroup_p (struct gdbarch *gdbarch, int regno,
+ struct reggroup *reggroup)
+{
+ int num_regs = gdbarch_num_regs (gdbarch);
+ int num_pseudo_regs = gdbarch_num_pseudo_regs (gdbarch);
+ struct tdesc_reg *reg = tdesc_find_register (gdbarch, regno);
+
+ if (reg == NULL && regno >= num_regs && regno < num_regs + num_pseudo_regs)
+ {
+ struct tdesc_arch_data *data = gdbarch_data (gdbarch, tdesc_data);
+ gdb_assert (data->pseudo_register_reggroup_p != NULL);
+ return data->pseudo_register_reggroup_p (gdbarch, regno, reggroup);
+ }
+
+ if (reg != NULL && reg->group != NULL)
+ {
+ int general_p = 0, float_p = 0, vector_p = 0;
+
+ if (strcmp (reg->group, "general") == 0)
+ general_p = 1;
+ else if (strcmp (reg->group, "float") == 0)
+ float_p = 1;
+ else if (strcmp (reg->group, "vector") == 0)
+ vector_p = 1;
+
+ if (reggroup == float_reggroup)
+ return float_p;
+
+ if (reggroup == vector_reggroup)
+ return vector_p;
+
+ if (reggroup == general_reggroup)
+ return general_p;
+ }
+
+ if (reg != NULL
+ && (reggroup == save_reggroup || reggroup == restore_reggroup))
+ return reg->save_restore;
+
+ return default_register_reggroup_p (gdbarch, regno, reggroup);
+}
+
+/* Record architecture-specific functions to call for pseudo-register
+ support. */
+
+void
+set_tdesc_pseudo_register_name (struct gdbarch *gdbarch,
+ gdbarch_register_name_ftype *pseudo_name)
+{
+ struct tdesc_arch_data *data = gdbarch_data (gdbarch, tdesc_data);
+
+ data->pseudo_register_name = pseudo_name;
+}
+
+void
+set_tdesc_pseudo_register_type (struct gdbarch *gdbarch,
+ gdbarch_register_type_ftype *pseudo_type)
+{
+ struct tdesc_arch_data *data = gdbarch_data (gdbarch, tdesc_data);
+
+ data->pseudo_register_type = pseudo_type;
+}
+
+void
+set_tdesc_pseudo_register_reggroup_p
+ (struct gdbarch *gdbarch,
+ gdbarch_register_reggroup_p_ftype *pseudo_reggroup_p)
+{
+ struct tdesc_arch_data *data = gdbarch_data (gdbarch, tdesc_data);
+
+ data->pseudo_register_reggroup_p = pseudo_reggroup_p;
+}
+
+/* Update GDBARCH to use the target description for registers. */
+
+void
+tdesc_use_registers (struct gdbarch *gdbarch,
+ struct tdesc_arch_data *early_data)
+{
+ int num_regs = gdbarch_num_regs (gdbarch);
+ int i, ixf, ixr;
+ const struct target_desc *target_desc;
+ struct tdesc_feature *feature;
+ struct tdesc_reg *reg;
+ struct tdesc_arch_data *data;
+ htab_t reg_hash;
+
+ target_desc = gdbarch_target_desc (gdbarch);
+
+ /* We can't use the description for registers if it doesn't describe
+ any. This function should only be called after validating
+ registers, so the caller should know that registers are
+ included. */
+ gdb_assert (tdesc_has_registers (target_desc));
+
+ data = gdbarch_data (gdbarch, tdesc_data);
+ data->registers = early_data->registers;
+ xfree (early_data);
+
+ /* Build up a set of all registers, so that we can assign register
+ numbers where needed. The hash table expands as necessary, so
+ the initial size is arbitrary. */
+ reg_hash = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL);
+ for (ixf = 0;
+ VEC_iterate (tdesc_feature_p, target_desc->features, ixf, feature);
+ ixf++)
+ for (ixr = 0;
+ VEC_iterate (tdesc_reg_p, feature->registers, ixr, reg);
+ ixr++)
+ {
+ void **slot = htab_find_slot (reg_hash, reg, INSERT);
+
+ *slot = reg;
+ }
+
+ /* Remove any registers which were assigned numbers by the
+ architecture. */
+ for (ixr = 0; VEC_iterate (tdesc_reg_p, data->registers, ixr, reg); ixr++)
+ if (reg)
+ htab_remove_elt (reg_hash, reg);
+
+ /* Assign numbers to the remaining registers and add them to the
+ list of registers. The new numbers are always above NUM_REGS.
+ Iterate over the features, not the hash table, so that the order
+ matches that in the target description. */
+
+ gdb_assert (VEC_length (tdesc_reg_p, data->registers) <= num_regs);
+ while (VEC_length (tdesc_reg_p, data->registers) < num_regs)
+ VEC_safe_push (tdesc_reg_p, data->registers, NULL);
+ for (ixf = 0;
+ VEC_iterate (tdesc_feature_p, target_desc->features, ixf, feature);
+ ixf++)
+ for (ixr = 0;
+ VEC_iterate (tdesc_reg_p, feature->registers, ixr, reg);
+ ixr++)
+ if (htab_find (reg_hash, reg) != NULL)
+ {
+ VEC_safe_push (tdesc_reg_p, data->registers, reg);
+ num_regs++;
+ }
+
+ htab_delete (reg_hash);
+
+ /* Update the architecture. */
+ set_gdbarch_num_regs (gdbarch, num_regs);
+ set_gdbarch_register_name (gdbarch, tdesc_register_name);
+ set_gdbarch_register_type (gdbarch, tdesc_register_type);
+ set_gdbarch_remote_register_number (gdbarch,
+ tdesc_remote_register_number);
+ set_gdbarch_register_reggroup_p (gdbarch, tdesc_register_reggroup_p);
+}
+\f
+
/* Methods for constructing a target description. */
+static void
+tdesc_free_reg (struct tdesc_reg *reg)
+{
+ xfree (reg->name);
+ xfree (reg->type);
+ xfree (reg->group);
+ xfree (reg);
+}
+
+void
+tdesc_create_reg (struct tdesc_feature *feature, const char *name,
+ int regnum, int save_restore, const char *group,
+ int bitsize, const char *type)
+{
+ struct tdesc_reg *reg = XZALLOC (struct tdesc_reg);
+
+ reg->name = xstrdup (name);
+ reg->target_regnum = regnum;
+ reg->save_restore = save_restore;
+ reg->group = group ? xstrdup (group) : NULL;
+ reg->bitsize = bitsize;
+ reg->type = type ? xstrdup (type) : NULL;
+
+ /* If the register's type is target-defined, look it up now. We may not
+ have easy access to the containing feature when we want it later. */
+ reg->gdb_type = tdesc_named_type (feature, reg->type);
+
+ VEC_safe_push (tdesc_reg_p, feature->registers, reg);
+}
+
+static void
+tdesc_free_feature (struct tdesc_feature *feature)
+{
+ struct tdesc_reg *reg;
+ int ix;
+
+ for (ix = 0; VEC_iterate (tdesc_reg_p, feature->registers, ix, reg); ix++)
+ tdesc_free_reg (reg);
+ VEC_free (tdesc_reg_p, feature->registers);
+
+ /* There is no easy way to free xmalloc-allocated types, nor is
+ there a way to allocate types on an obstack not associated with
+ an objfile. Therefore we never free types. Since we only ever
+ parse an identical XML document once, this memory leak is mostly
+ contained. */
+ VEC_free (type_p, feature->types);
+
+ xfree (feature->name);
+ xfree (feature);
+}
+
+struct tdesc_feature *
+tdesc_create_feature (struct target_desc *tdesc, const char *name)
+{
+ struct tdesc_feature *new_feature = XZALLOC (struct tdesc_feature);
+
+ new_feature->name = xstrdup (name);
+
+ VEC_safe_push (tdesc_feature_p, tdesc->features, new_feature);
+ return new_feature;
+}
+
+void
+tdesc_record_type (struct tdesc_feature *feature, struct type *type)
+{
+ /* The type's ID should be used as its TYPE_NAME. */
+ gdb_assert (TYPE_NAME (type) != NULL);
+
+ VEC_safe_push (type_p, feature->types, type);
+}
+
struct target_desc *
allocate_target_description (void)
{
return XZALLOC (struct target_desc);
}
+static void
+free_target_description (void *arg)
+{
+ struct target_desc *target_desc = arg;
+ struct tdesc_feature *feature;
+ struct property *prop;
+ int ix;
+
+ for (ix = 0;
+ VEC_iterate (tdesc_feature_p, target_desc->features, ix, feature);
+ ix++)
+ tdesc_free_feature (feature);
+ VEC_free (tdesc_feature_p, target_desc->features);
+
+ for (ix = 0;
+ VEC_iterate (property_s, target_desc->properties, ix, prop);
+ ix++)
+ {
+ xfree (prop->key);
+ xfree (prop->value);
+ }
+ VEC_free (property_s, target_desc->properties);
+
+ xfree (target_desc);
+}
+
+struct cleanup *
+make_cleanup_free_target_description (struct target_desc *target_desc)
+{
+ return make_cleanup (free_target_description, target_desc);
+}
+
void
set_tdesc_property (struct target_desc *target_desc,
const char *key, const char *value)
internal_error (__FILE__, __LINE__,
_("Attempted to add duplicate property \"%s\""), key);
- new_prop.key = key;
- new_prop.value = value;
+ new_prop.key = xstrdup (key);
+ new_prop.value = xstrdup (value);
VEC_safe_push (property_s, target_desc->properties, &new_prop);
}
+
+void
+set_tdesc_architecture (struct target_desc *target_desc,
+ const struct bfd_arch_info *arch)
+{
+ target_desc->arch = arch;
+}
+\f
+
+static struct cmd_list_element *tdesc_set_cmdlist, *tdesc_show_cmdlist;
+static struct cmd_list_element *tdesc_unset_cmdlist;
+
+/* Helper functions for the CLI commands. */
+
+static void
+set_tdesc_cmd (char *args, int from_tty)
+{
+ help_list (tdesc_set_cmdlist, "set tdesc ", -1, gdb_stdout);
+}
+
+static void
+show_tdesc_cmd (char *args, int from_tty)
+{
+ cmd_show_list (tdesc_show_cmdlist, from_tty, "");
+}
+
+static void
+unset_tdesc_cmd (char *args, int from_tty)
+{
+ help_list (tdesc_unset_cmdlist, "unset tdesc ", -1, gdb_stdout);
+}
+
+static void
+set_tdesc_filename_cmd (char *args, int from_tty,
+ struct cmd_list_element *c)
+{
+ target_clear_description ();
+ target_find_description ();
+}
+
+static void
+show_tdesc_filename_cmd (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c,
+ const char *value)
+{
+ if (value != NULL && *value != '\0')
+ printf_filtered (_("\
+The target description will be read from \"%s\".\n"),
+ value);
+ else
+ printf_filtered (_("\
+The target description will be read from the target.\n"));
+}
+
+static void
+unset_tdesc_filename_cmd (char *args, int from_tty)
+{
+ xfree (target_description_filename);
+ target_description_filename = NULL;
+ target_clear_description ();
+ target_find_description ();
+}
+
+void
+_initialize_target_descriptions (void)
+{
+ tdesc_data = gdbarch_data_register_pre_init (tdesc_data_init);
+
+ add_prefix_cmd ("tdesc", class_maintenance, set_tdesc_cmd, _("\
+Set target description specific variables."),
+ &tdesc_set_cmdlist, "set tdesc ",
+ 0 /* allow-unknown */, &setlist);
+ add_prefix_cmd ("tdesc", class_maintenance, show_tdesc_cmd, _("\
+Show target description specific variables."),
+ &tdesc_show_cmdlist, "show tdesc ",
+ 0 /* allow-unknown */, &showlist);
+ add_prefix_cmd ("tdesc", class_maintenance, unset_tdesc_cmd, _("\
+Unset target description specific variables."),
+ &tdesc_unset_cmdlist, "unset tdesc ",
+ 0 /* allow-unknown */, &unsetlist);
+
+ add_setshow_filename_cmd ("filename", class_obscure,
+ &target_description_filename,
+ _("\
+Set the file to read for an XML target description"), _("\
+Show the file to read for an XML target description"), _("\
+When set, GDB will read the target description from a local\n\
+file instead of querying the remote target."),
+ set_tdesc_filename_cmd,
+ show_tdesc_filename_cmd,
+ &tdesc_set_cmdlist, &tdesc_show_cmdlist);
+
+ add_cmd ("filename", class_obscure, unset_tdesc_filename_cmd, _("\
+Unset the file to read for an XML target description. When unset,\n\
+GDB will read the description from the target."),
+ &tdesc_unset_cmdlist);
+}