Convert frame unwinders to use the current frame and

"struct value".

	* frame.c (frame_debug): Make global.
	(get_frame_id): Pass this frame to unwinder routines.
	(frame_pc_unwind): Remove unused unwind->prev_pc support.
	(do_frame_register_read): Do not discard the return value of
	frame_register_read.
	(frame_register_unwind): Remove debug messages.  Use
	frame_unwind_register_value.
	(frame_unwind_register_value, get_frame_register_value): New
	functions.
	(create_new_frame, get_frame_base_address, get_frame_locals_address)
	(get_frame_args_address, get_frame_type): Pass this frame to
	unwinder routines.
	(frame_cleanup_after_sniffer, frame_prepare_for_sniffer): New
	functions.
	* frame.h: Update comments.
	(frame_debug, frame_unwind_register_value, get_frame_register_value)
	(frame_prepare_for_sniffer): Declare.
	* frame-unwind.h: Update comments and parameter names.
	(default_frame_sniffer): Declare.
	(frame_prev_register_ftype): Return a struct value *.
	(struct frame_unwind): Remove prev_pc member.
	(frame_unwind_sniffer_ftype, frame_unwind_append_sniffer): Delete.
	(frame_unwind_append_unwinder, frame_unwind_got_optimized)
	(frame_unwind_got_register, frame_unwind_got_memory)
	(frame_unwind_got_constant, frame_unwind_got_address): Declare.
	* frame-base.h: Update comments and parameter names.
	* valops.c (value_fetch_lazy): Use get_frame_register_value.  Iterate
	if necessary.  Add debugging output.
	* sentinel-frame.c (sentinel_frame_prev_register)
	(sentinel_frame_this_id): Update for new signature.
	(sentinel_frame_prev_pc): Delete.
	(sentinel_frame_unwinder): Remove prev_pc.
	* ia64-tdep.c (ia64_libunwind_frame_unwind): Do not initialize
	prev_pc.
	* libunwind-frame.c (libunwind_frame_unwind): Likewise.
	* frame-unwind.c (struct frame_unwind_table_entry): Remove sniffer.
	(frame_unwind_append_sniffer): Delete.
	(frame_unwind_append_unwinder): New function.
	(frame_unwind_find_by_frame): Take this frame.  Only use sniffers
	from unwinders.  Use frame_prepare_for_sniffer.
	(default_frame_sniffer, frame_unwind_got_optimized)
	(frame_unwind_got_register, frame_unwind_got_memory)
	(frame_unwind_got_constant, frame_unwind_got_address): New functions.
	* dummy-frame.c (dummy_frame_sniffer): Use gdbarch_dummy_id.
	(dummy_frame_prev_register, dummy_frame_this_id): Update for new
	signature.
	* gdbarch.sh: Replace unwind_dummy_id with dummy_id.
	* gdbarch.c, gdbarch.c: Regenerated.
	* frame-base.c (default_frame_base_address)
	(default_frame_locals_address, default_frame_args_address): Update
	for new signature.
	(frame_base_find_by_frame): Pass this frame to unwinder routines.
	* infcall.c (call_function_by_hand): Update comments.
	* Makefile.in (frame-unwind.o): Update dependencies.

	* gdbint.texinfo (Stack Frames): New chapter.
	(Algorithms): Move Frames text to the new chapter.
	(Target Conditionals): Delete SAVE_DUMMY_FRAME_TOS.  Document
	gdbarch_dummy_id instead of gdbarch_unwind_dummy_id.

gdb/sentinel-frame.c

@@ -42,34 +42,31 @@ sentinel_frame_cache (struct regcache *regcache)
 
 /* Here the register value is taken direct from the register cache.  */
 
-static void
-sentinel_frame_prev_register (struct frame_info *next_frame,
+static struct value *
+sentinel_frame_prev_register (struct frame_info *this_frame,
 			      void **this_prologue_cache,
-			      int regnum, int *optimized,
-			      enum lval_type *lvalp, CORE_ADDR *addrp,
-			      int *realnum, gdb_byte *bufferp)
+			      int regnum)
 {
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
   struct frame_unwind_cache *cache = *this_prologue_cache;
-  /* Describe the register's location.  A reg-frame maps all registers
-     onto the corresponding hardware register.  */
-  *optimized = 0;
-  *lvalp = lval_register;
-  *addrp = 0;
-  *realnum = regnum;
+  struct value *value;
 
-  /* If needed, find and return the value of the register.  */
-  if (bufferp != NULL)
-    {
-      /* Return the actual value.  */
-      /* Use the regcache_cooked_read() method so that it, on the fly,
-         constructs either a raw or pseudo register from the raw
-         register cache.  */
-      regcache_cooked_read (cache->regcache, regnum, bufferp);
-    }
+  /* Return the actual value.  */
+  value = allocate_value (register_type (gdbarch, regnum));
+  VALUE_LVAL (value) = lval_register;
+  VALUE_REGNUM (value) = regnum;
+  VALUE_FRAME_ID (value) = get_frame_id (this_frame);
+
+  /* Use the regcache_cooked_read() method so that it, on the fly,
+     constructs either a raw or pseudo register from the raw
+     register cache.  */
+  regcache_cooked_read (cache->regcache, regnum, value_contents_raw (value));
+
+  return value;
 }
 
 static void
-sentinel_frame_this_id (struct frame_info *next_frame,
+sentinel_frame_this_id (struct frame_info *this_frame,
 			void **this_prologue_cache,
 			struct frame_id *this_id)
 {
@@ -79,22 +76,11 @@ sentinel_frame_this_id (struct frame_info *next_frame,
   internal_error (__FILE__, __LINE__, _("sentinel_frame_this_id called"));
 }
 
-static CORE_ADDR
-sentinel_frame_prev_pc (struct frame_info *next_frame,
-			void **this_prologue_cache)
-{
-  struct gdbarch *gdbarch = get_frame_arch (next_frame);
-  return gdbarch_unwind_pc (gdbarch, next_frame);
-}
-
 const struct frame_unwind sentinel_frame_unwinder =
 {
   SENTINEL_FRAME,
   sentinel_frame_this_id,
-  sentinel_frame_prev_register,
-  NULL, /* unwind_data */
-  NULL, /* sniffer */
-  sentinel_frame_prev_pc,
+  sentinel_frame_prev_register
 };
 
 const struct frame_unwind *const sentinel_frame_unwind = &sentinel_frame_unwinder;