2003-06-16 Andrew Cagney <cagney@redhat.com>

	* frame.h (deprecated_get_next_frame_hack): Declare.
	* frame.c (legacy_saved_regs_prev_register): Only require
	DEPRECATED_FRAME_INIT_SAVED_REGS when it is needed.  Assert that
	there are always saved regs.
	(deprecated_generic_get_saved_register): Do not require
	DEPRECATED_FRAME_INIT_SAVED_REGS.
	(legacy_get_prev_frame): Do not require DEPRECATED_FRAME_CHAIN,
	use frame ID unwind instead.
	(deprecated_get_next_frame_hack): New function.

3 files changed, 68 insertions, 14 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 1449f79..96ff655 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,15 @@
+2003-06-16  Andrew Cagney  <cagney@redhat.com>
+
+	* frame.h (deprecated_get_next_frame_hack): Declare.
+	* frame.c (legacy_saved_regs_prev_register): Only require
+	DEPRECATED_FRAME_INIT_SAVED_REGS when it is needed.  Assert that
+	there are always saved regs.
+	(deprecated_generic_get_saved_register): Do not require
+	DEPRECATED_FRAME_INIT_SAVED_REGS.
+	(legacy_get_prev_frame): Do not require DEPRECATED_FRAME_CHAIN,
+	use frame ID unwind instead.
+	(deprecated_get_next_frame_hack): New function.
+
 2003-06-16  Corinna Vinschen  <vinschen@redhat.com>
 
 	* h8300-tdep.c (h8300_push_arguments): Remove.  Substitute by...
diff --git a/gdb/frame.c b/gdb/frame.c
index 9a4af35..55e9dc5 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -993,14 +993,13 @@ legacy_saved_regs_prev_register (struct frame_info *next_frame,
   struct frame_info *frame = next_frame->prev;
   gdb_assert (frame != NULL);
 
-  /* Only (older) architectures that implement the
-     DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this
-     function.  */
-  gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
-
-  /* Load the saved_regs register cache.  */
   if (get_frame_saved_regs (frame) == NULL)
-    DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
+    {
+      /* If nothing's initialized the saved regs, do it now.  */
+      gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
+      DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
+      gdb_assert (get_frame_saved_regs (frame) != NULL);
+    }
 
   if (get_frame_saved_regs (frame) != NULL
       && get_frame_saved_regs (frame)[regnum] != 0)
@@ -1112,8 +1111,6 @@ deprecated_generic_get_saved_register (char *raw_buffer, int *optimized,
   if (!target_has_registers)
     error ("No registers.");
 
-  gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
-
   /* Normal systems don't optimize out things with register numbers.  */
   if (optimized != NULL)
     *optimized = 0;
@@ -1267,6 +1264,12 @@ get_next_frame (struct frame_info *this_frame)
     return NULL;
 }
 
+struct frame_info *
+deprecated_get_next_frame_hack (struct frame_info *this_frame)
+{
+  return this_frame->next;
+}
+
 /* Flush the entire frame cache.  */
 
 void
@@ -1501,6 +1504,12 @@ legacy_get_prev_frame (struct frame_info *this_frame)
     /* FIXME: 2002-11-09: There isn't any reason to special case this
        edge condition.  Instead the per-architecture code should hande
        it locally.  */
+    /* FIXME: cagney/2003-06-16: This returns the inner most stack
+       address for the previous frame, that, however, is wrong.  It
+       should be the inner most stack address for the previous to
+       previous frame.  This is because it is the previous to previous
+       frame's innermost stack address that is constant through out
+       the lifetime of the previous frame (trust me :-).  */
     address = get_frame_base (this_frame);
   else
     {
@@ -1519,8 +1528,29 @@ legacy_get_prev_frame (struct frame_info *this_frame)
          this to after the ffi test; I'd rather have backtraces from
          start go curfluy than have an abort called from main not show
          main.  */
-      gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
-      address = DEPRECATED_FRAME_CHAIN (this_frame);
+      if (DEPRECATED_FRAME_CHAIN_P ())
+	address = DEPRECATED_FRAME_CHAIN (this_frame);
+      else
+	{
+	  /* Someone is part way through coverting an old architecture
+             to the new frame code.  Implement FRAME_CHAIN the way the
+             new frame will.  */
+	  /* Find PREV frame's unwinder.  */
+	  prev->unwind = frame_unwind_find_by_pc (current_gdbarch,
+						  frame_pc_unwind (this_frame));
+	  /* FIXME: cagney/2003-04-02: Rather than storing the frame's
+	     type in the frame, the unwinder's type should be returned
+	     directly.  Unfortunatly, legacy code, called by
+	     legacy_get_prev_frame, explicitly set the frames type
+	     using the method deprecated_set_frame_type().  */
+	  prev->type = prev->unwind->type;
+	  /* Find PREV frame's ID.  */
+	  prev->unwind->this_id (this_frame,
+				 &prev->prologue_cache,
+				 &prev->this_id.value);
+	  prev->this_id.p = 1;
+	  address = prev->this_id.value.stack_addr;
+	}
 
       if (!legacy_frame_chain_valid (address, this_frame))
 	{
@@ -1663,9 +1693,13 @@ legacy_get_prev_frame (struct frame_info *this_frame)
   /* Initialize the code used to unwind the frame PREV based on the PC
      (and probably other architectural information).  The PC lets you
      check things like the debug info at that point (dwarf2cfi?) and
-     use that to decide how the frame should be unwound.  */
-  prev->unwind = frame_unwind_find_by_pc (current_gdbarch,
-					  get_frame_pc (prev));
+     use that to decide how the frame should be unwound.
+
+     If there isn't a FRAME_CHAIN, the code above will have already
+     done this.  */
+  if (prev->unwind == NULL)
+    prev->unwind = frame_unwind_find_by_pc (current_gdbarch,
+					    get_frame_pc (prev));
 
   /* If the unwinder provides a frame type, use it.  Otherwize
      continue on to that heuristic mess.  */
@@ -1673,6 +1707,7 @@ legacy_get_prev_frame (struct frame_info *this_frame)
     {
       prev->type = prev->unwind->type;
       if (prev->type == NORMAL_FRAME)
+	/* FIXME: cagney/2003-06-16: would get_frame_pc() be better?  */
 	prev->this_id.value.code_addr
 	  = get_pc_function_start (prev->this_id.value.code_addr);
       if (frame_debug)
diff --git a/gdb/frame.h b/gdb/frame.h
index ecca9f1..14da014 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -154,6 +154,13 @@ extern void select_frame (struct frame_info *);
 extern struct frame_info *get_prev_frame (struct frame_info *);
 extern struct frame_info *get_next_frame (struct frame_info *);
 
+/* Given a FRAME, return the true next (more inner, younger) frame.
+   This one exposes the sentinel frame and, hence, never returns NULL.
+   It is here strictly to help old targets in their migration path to
+   the new frame code - the new code requires the NEXT, and not THIS
+   frame.  */
+extern struct frame_info *deprecated_get_next_frame_hack (struct frame_info *);
+
 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
    is not found.  */
 extern struct frame_info *frame_find_by_id (struct frame_id id);