+extern struct address_space *get_regcache_aspace (const struct regcache *);
+
+enum register_status
+ {
+ /* The register value is not in the cache, and we don't know yet
+ whether it's available in the target (or traceframe). */
+ REG_UNKNOWN = 0,
+
+ /* The register value is valid and cached. */
+ REG_VALID = 1,
+
+ /* The register value is unavailable. E.g., we're inspecting a
+ traceframe, and this register wasn't collected. Note that this
+ is different a different "unavailable" from saying the register
+ does not exist in the target's architecture --- in that case,
+ the target should have given us a target description that does
+ not include the register in the first place. */
+ REG_UNAVAILABLE = -1
+ };
+
+enum register_status regcache_register_status (const struct regcache *regcache,
+ int regnum);