regcache: Add functions suitable for regset_supply/collect.

These functions are intended to suit all targets that don't require too
special logic in their regset supply/collect methods.  Having such
generic functions helps reducing target-specific complexity.

1 files changed, 45 insertions, 0 deletions

diff --git a/gdb/regcache.h b/gdb/regcache.h
index 8423f57..0361f22 100644
--- a/gdb/regcache.h
+++ b/gdb/regcache.h
@@ -147,6 +147,51 @@ extern void regcache_raw_supply (struct regcache *regcache,
 extern void regcache_raw_collect (const struct regcache *regcache,
 				  int regnum, void *buf);
 
+/* Mapping between register numbers and offsets in a buffer, for use
+   in the '*regset' functions below.  In an array of
+   'regcache_map_entry' each element is interpreted like follows:
+
+   - If 'regno' is a register number: Map register 'regno' to the
+     current offset (starting with 0) and increase the current offset
+     by 'size' (or the register's size, if 'size' is zero).  Repeat
+     this with consecutive register numbers up to 'regno+count-1'.
+
+   - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
+     offset.
+
+   - If count=0: End of the map.  */
+
+struct regcache_map_entry
+{
+  int count;
+  int regno;
+  int size;
+};
+
+/* Special value for the 'regno' field in the struct above.  */
+
+enum
+  {
+    REGCACHE_MAP_SKIP = -1,
+  };
+
+/* Transfer a set of registers (as described by REGSET) between
+   REGCACHE and BUF.  If REGNUM == -1, transfer all registers
+   belonging to the regset, otherwise just the register numbered
+   REGNUM.  The REGSET's 'regmap' field must point to an array of
+   'struct regcache_map_entry'.
+
+   These functions are suitable for the 'regset_supply' and
+   'regset_collect' fields in a regset structure.  */
+
+extern void regcache_supply_regset (const struct regset *regset,
+				    struct regcache *regcache,
+				    int regnum, const void *buf,
+				    size_t size);
+extern void regcache_collect_regset (const struct regset *regset,
+				     const struct regcache *regcache,
+				     int regnum, void *buf, size_t size);
+
 
 /* The type of a register.  This function is slightly more efficient
    then its gdbarch vector counterpart since it returns a precomputed