[PATCH v2 02/13] regcache: Add functions suitable for regset_supply/collect.

Andreas Arnez
2014-06-25T16:49:20Z

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.

gdb/
* regcache.c: Include "regset.h".
(regcache_supply_regset, regcache_collect_regset): New functions.
* regcache.h (struct regcache_map_entry): New structure.
(REGCACHE_MAP_SKIP_BYTES): New enum value.
(regcache_supply_regset, regcache_collect_regset): New prototypes.
---
gdb/regcache.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
gdb/regcache.h | 44 +++++++++++++++++++++++++++++++++++++++
2 files changed, 110 insertions(+)

diff --git a/gdb/regcache.c b/gdb/regcache.c
index 5ee90b0..78fd962 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -30,6 +30,7 @@
#include "exceptions.h"
#include "remote.h"
#include "valprint.h"
+#include "regset.h"

/*
* DATA STRUCTURE
@@ -1068,6 +1069,71 @@ regcache_raw_collect (const struct regcache *regcache, int regnum, void *buf)
memcpy (buf, regbuf, size);
}

+/* Supply register REGNUM from BUF to REGCACHE, using the register map
+ in REGSET. If REGNUM is -1, do this for all registers in
+ REGSET. */
+
+void
+regcache_supply_regset (const struct regset *regset,
+ struct regcache *regcache,
+ int regnum, const void *buf, size_t size)
+{
+ const struct regcache_map_entry *map = regset->regmap;
+ int offs = 0;
+ int i, count;
+
+ for (i = 0; (count = map[i].count) != 0; i++)
+ {
+ int regno = map[i].regno;
+
+ if (regno == REGCACHE_MAP_SKIP_BYTES)
+ offs += count;
+ else
+ for (; count--; regno++)
+ {
+ int new_offs = offs + regcache->descr->sizeof_register[regno];
+
+ if (new_offs <= size && (regnum == -1 || regnum == regno))
+ regcache_raw_supply (regcache, regno,
+ buf ? (const gdb_byte *) buf + offs
+ : NULL);
+ offs = new_offs;
+ }
+ }
+}
+
+/* Collect register REGNUM from REGCACHE to BUF, using the register
+ map in REGSET. If REGNUM is -1, do this for all registers in
+ REGSET. */
+
+void
+regcache_collect_regset (const struct regset *regset,
+ const struct regcache *regcache,
+ int regnum, void *buf, size_t size)
+{
+ const struct regcache_map_entry *map = regset->regmap;
+ int offs = 0;
+ int i, count;
+
+ for (i = 0; (count = map[i].count) != 0; i++)
+ {
+ int regno = map[i].regno;
+
+ if (regno == REGCACHE_MAP_SKIP_BYTES)
+ offs += count;
+ else
+ for (; count--; regno++)
+ {
+ int new_offs = offs + regcache->descr->sizeof_register[regno];
+
+ if (new_offs <= size && (regnum == -1 || regnum == regno))
+ regcache_raw_collect (regcache, regno,
+ (gdb_byte *) buf + offs);
+ offs = new_offs;
+ }
+ }
+}
+

/* Special handling for register PC. */

diff --git a/gdb/regcache.h b/gdb/regcache.h
index 8423f57..73ee043 100644
--- a/gdb/regcache.h
+++ b/gdb/regcache.h
@@ -147,6 +147,50 @@ 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 the register's size. Repeat this with consecutive register
+ numbers up to 'regno+count-1'.
+
+ - If 'regno' is REGCACHE_MAP_SKIP_BYTES: Add 'count' to the current
+ offset.
+
+ - If count=0: End of the map. */
+
+struct regcache_map_entry
+{
+ int count;
+ int regno;
+};
+
+/* Special value for the 'regno' field in the struct above. */
+
+enum
+ {
+ REGCACHE_MAP_SKIP_BYTES = -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
--
1.8.4.2