Rename regcache_cooked_read_ftype and make a function_view

regcache_cooked_read_ftype can be converted to a function_view, which
allows us to use lambda functions and therefore avoid having to pass an
opaque pointer parameter.

Adjusting the fallouts showed that the "const regcache &" passed to the
readonly_detached_regcache constructor is cast to non-const in
do_cooked_read.  I changed the constructor parameter to be non-const.

Finally, I renamed the typedef from regcache_cooked_read_ftype to
register_read_ftype, since there is nothing that forces us to use it
only for regcaches nor cooked registers.

gdb/ChangeLog:

	* regcache.h (regcache_cooked_read_ftype): Rename to...
	(register_read_ftype): ...this, change type to function_view.
	(class reg_buffer) <save>: Remove src parameter.
	(readonly_detached_regcache) <readonly_detached_regcache>: Make
	parameter non-const in first overload.  Remove src parameter in
	second overload.
	* regcache.c (do_cooked_read): Remove.
	(readonly_detached_regcache::readonly_detached_regcache): Make
	parameter non-const, adjust call to other constructor.
	(reg_buffer::save): Remove src parameter.
	* frame.c (do_frame_register_read): Remove.
	(frame_save_as_regcache): Use lambda function.
	* ppc-linux-tdep.c (ppu2spu_unwind_register): Change type of src
	parameter to ppu2spu_data *.
	(ppu2spu_sniffer): Use lambda function.

1 files changed, 6 insertions, 5 deletions

diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index f26882fe3c8..9f4c1fc891b 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -1371,9 +1371,8 @@ struct ppu2spu_data
 };
 
 static enum register_status
-ppu2spu_unwind_register (void *src, int regnum, gdb_byte *buf)
+ppu2spu_unwind_register (ppu2spu_data *data, int regnum, gdb_byte *buf)
 {
-  struct ppu2spu_data *data = (struct ppu2spu_data *) src;
   enum bfd_endian byte_order = gdbarch_byte_order (data->gdbarch);
 
   if (regnum >= 0 && regnum < SPU_NUM_GPRS)
@@ -1435,12 +1434,14 @@ ppu2spu_sniffer (const struct frame_unwind *self,
 		       data.gprs, 0, sizeof data.gprs)
 	  == sizeof data.gprs)
 	{
+	  auto cooked_read = [&data] (int regnum, gdb_byte *buf)
+	    {
+	      return ppu2spu_unwind_register (&data, regnum, buf);
+	    };
 	  struct ppu2spu_cache *cache
 	    = FRAME_OBSTACK_CALLOC (1, struct ppu2spu_cache);
 	  std::unique_ptr<readonly_detached_regcache> regcache
-	    (new readonly_detached_regcache (data.gdbarch,
-					     ppu2spu_unwind_register,
-					     &data));
+	    (new readonly_detached_regcache (data.gdbarch, cooked_read));
 
 	  cache->frame_id = frame_id_build (base, func);
 	  cache->regcache = regcache.release ();