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.

1 files changed, 17 insertions, 1 deletions

diff --git a/gdb/frame.h b/gdb/frame.h
index 6d935965b..c1f9d7e 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -144,6 +144,10 @@ struct frame_id
 /* For convenience.  All fields are zero.  */
 extern const struct frame_id null_frame_id;
 
+/* Flag to control debugging.  */
+
+extern int frame_debug;
+
 /* Construct a frame ID.  The first parameter is the frame's constant
    stack address (typically the outer-bound), and the second the
    frame's constant code address (typically the entry point).
@@ -460,13 +464,19 @@ extern void frame_register_unwind (struct frame_info *frame, int regnum,
 /* Fetch a register from this, or unwind a register from the next
    frame.  Note that the get_frame methods are wrappers to
    frame->next->unwind.  They all [potentially] throw an error if the
-   fetch fails.  */
+   fetch fails.  The value methods never return NULL, but usually
+   do return a lazy value.  */
 
 extern void frame_unwind_register (struct frame_info *frame,
 				   int regnum, gdb_byte *buf);
 extern void get_frame_register (struct frame_info *frame,
 				int regnum, gdb_byte *buf);
 
+struct value *frame_unwind_register_value (struct frame_info *frame,
+					   int regnum);
+struct value *get_frame_register_value (struct frame_info *frame,
+					int regnum);
+
 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
 					     int regnum);
 extern LONGEST get_frame_register_signed (struct frame_info *frame,
@@ -666,6 +676,12 @@ extern void (*deprecated_selected_frame_level_changed_hook) (int);
 
 extern void return_command (char *, int);
 
+/* Set FRAME's unwinder temporarily, so that we can call a sniffer.
+   Return a cleanup which should be called if unwinding fails, and
+   discarded if it succeeds.  */
+
+struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
+					   const struct frame_unwind *unwind);
 
 /* Notes (cagney/2002-11-27, drow/2003-09-06):