gdb/

* regcache.h (regcache_raw_read, regcache_raw_read_signed)
	(regcache_raw_read_unsigned, regcache_raw_read_signed)
	(regcache_raw_read_unsigned, regcache_raw_read_part)
	(regcache_cooked_read, regcache_cooked_read_signed)
	(regcache_cooked_read_unsigned, regcache_cooked_read_part)
	(regcache_cooked_read_ftype): Change return to enum
	register_status.
	* regcache.c: Include exceptions.h
	(regcache_save): Adjust to handle REG_UNAVAILABLE registers.
	(do_cooked_read): Change return to enum register_status.  Always
	forward to regcache_cooked_read.
	(regcache_raw_read): Change return to enum register_status.  If
	the register is not REG_VALID, memset the buffer.  Return the
	register's status.
	(regcache_raw_read_signed): Handle non-REG_VALID registers and
	return the register's status.
	(regcache_raw_read_unsigned): Ditto.
	(regcache_cooked_read): Change return to enum register_status.
	Assert that with read-only regcaches, the register's status must
	be known.  If the regcache is read-only, and the register is not
	REG_VALID, memset the buffer.  Return the register's status.
	(regcache_cooked_read_signed): Change return to enum
	register_status.  Handle non-REG_VALID registers and return the
	register's status.
	(regcache_cooked_read_unsigned): Change return to enum
	register_status.  Handle non-REG_VALID registers and return the
	register's status.
	(regcache_xfer_part, regcache_raw_read_part)
	(regcache_cooked_read_part): Change return to enum
	register_status.  Return the register's status.
	(regcache_read_pc): Throw NOT_AVAILABLE_ERROR if the register is
	unavailable.
	(regcache_dump): Handle unavailable cooked registers.
	* frame.c (do_frame_register_read): Adjust interface to match
	regcache_cooked_read_ftype.
	* gdbarch.sh (pseudo_register_read): Change return to enum
	register_status.
	* gdbarch.h, gdbarch.c: Regenerate.

	* i386-tdep.h (i386_pseudo_register_read): Change return to enum
	register_status.
	* i386-tdep.c (i386_pseudo_register_read): Change return to enum
	register_status.  If reading a raw register indicates the raw
	register is not valid, return the raw register's status,
	otherwise, return REG_VALID.
	* amd64-tdep.c (amd64_pseudo_register_read): Change return to enum
	register_status.  Handle non-REG_VALID raw registers and return
	the register's status.
	* arm-tdep.c (arm_neon_quad_read)
	(arm_pseudo_read): Change return to enum register_status.  Handle
	non-REG_VALID raw registers and return the register's status.
	* avr-tdep.c (avr_pseudo_register_read): Ditto.
	* frv-tdep.c (frv_pseudo_register_read): Ditto.
	* h8300-tdep.c (h8300_pseudo_register_read): Ditto.
	* hppa-tdep.c (hppa_pseudo_register_read): Ditto.
	* m32c-tdep.c (m32c_move_reg_t): Change return to enum
	register_status.
	(m32c_raw_read, m32c_raw_write, m32c_banked_read)
	(m32c_banked_write, m32c_sb_read, m32c_sb_write, m32c_part_read)
	(m32c_part_write, m32c_cat_read, m32c_cat_write)
	(m32c_r3r2r1r0_read, m32c_r3r2r1r0_write)
	(m32c_pseudo_register_read): Change return to enum
	register_status.  Adjust.
	* m68hc11-tdep.c (m68hc11_pseudo_register_read): Change return to
	enum register_status.  Return the register's status.
	* mep-tdep.c (mep_pseudo_cr32_read): Change return to enum
	register_status.  Return the register's status.
	(mep_pseudo_cr64_read, mep_pseudo_register_read): Ditto.
	* mips-tdep.c (mips_pseudo_register_read): Ditto.
	* mt-tdep.c (mt_pseudo_register_read): Ditto.
	* rs6000-tdep.c (move_ev_register_func): New typedef.
	(e500_move_ev_register): Use it.  Change return to enum
	register_status.  Return the register's status.
	(do_regcache_raw_read): New function.
	(do_regcache_raw_write): New function.
	(e500_pseudo_register_read): Change return to enum
	register_status.  Return the register's status.  Use
	do_regcache_raw_read.
	(e500_pseudo_register_write): Adjust.  Use do_regcache_raw_write.
	(dfp_pseudo_register_read): Change return to enum register_status.
	Return the register's status.
	(vsx_pseudo_register_read): Ditto.
	(efpr_pseudo_register_read): Ditto.
	(rs6000_pseudo_register_read): Ditto.
	* s390-tdep.c (s390_pseudo_register_read): Change return to enum
	register_status.  Return the register's status.
	* sh64-tdep.c (pseudo_register_read_portions): New function.
	(sh64_pseudo_register_read): Change return to enum
	register_status.  Use pseudo_register_read_portions.  Return the
	register's status.
	* ia64-tdep.c (ia64_pseudo_register_read): Change return to enum
	register_status.  Return the register's status.
	* sh-tdep.c (pseudo_register_read_portions): New function.
	(sh_pseudo_register_read): Change return to enum register_status.
	Use pseudo_register_read_portions.  Return the register's status.
	* sparc-tdep.c (sparc32_pseudo_register_read): Change return to
	enum register_status.  Return the register's status.
	* sparc64-tdep.c (sparc64_pseudo_register_read): Ditto.
	* spu-tdep.c (spu_pseudo_register_read_spu)
	(spu_pseudo_register_read): Ditto.
	* xtensa-tdep.c (xtensa_register_read_masked)
	(xtensa_pseudo_register_read): Ditto.
	* bfin-tdep.c (bfin_pseudo_register_read): Ditto.

gdb/sparc-tdep.c

@@ -373,16 +373,20 @@ sparc32_register_type (struct gdbarch *gdbarch, int regnum)
   return builtin_type (gdbarch)->builtin_int32;
 }
 
-static void
+static enum register_status
 sparc32_pseudo_register_read (struct gdbarch *gdbarch,
 			      struct regcache *regcache,
 			      int regnum, gdb_byte *buf)
 {
+  enum register_status status;
+
   gdb_assert (regnum >= SPARC32_D0_REGNUM && regnum <= SPARC32_D30_REGNUM);
 
   regnum = SPARC_F0_REGNUM + 2 * (regnum - SPARC32_D0_REGNUM);
-  regcache_raw_read (regcache, regnum, buf);
-  regcache_raw_read (regcache, regnum + 1, buf + 4);
+  status = regcache_raw_read (regcache, regnum, buf);
+  if (status == REG_VALID)
+    status = regcache_raw_read (regcache, regnum + 1, buf + 4);
+  return status;
 }
 
 static void