* frame.h (frame_unwind_arch): New.

(frame_unwind_caller_arch): Likewise.
	* frame-unwind.h (frame_prev_arch_ftype): New type.
	(struct frame_unwind): New member prev_arch.
	* frame.c (struct frame_info): New member prev_arch.
	(frame_unwind_arch): New function.
	(frame_unwind_caller_arch): Likewise..
	(get_frame_arch): Reimplement in terms of frame_unwind_arch.
	* sentinel-frame.c (sentinel_frame_prev_arch): New function.
	(sentinel_frame_unwinder): Install it.

	* frame.c (frame_pc_unwind): Use frame_unwind_arch instead
	of get_frame_arch.
	(frame_unwind_register_value): Likewise.
	(frame_unwind_register_signed): Likewise.
	(frame_unwind_register_unsigned): Likewise.
	* frame-unwind.c (frame_unwind_got_optimized): Likewise.
	(frame_unwind_got_register): Likewise.
	(frame_unwind_got_constant): Likewise.
	(frame_unwind_got_bytes): Likewise.
	(frame_unwind_got_address): Likewise.

	* frame.h (enum frame_type): New value ARCH_FRAME.
	* frame.c (fprint_frame_type): Handle ARCH_FRAME.
	* stack.c (print_frame_info): Likewise.

gdb/ChangeLog

@@ -1,3 +1,31 @@
+2009-07-02  Ulrich Weigand  <uweigand@de.ibm.com>
+
+	* frame.h (frame_unwind_arch): New.
+	(frame_unwind_caller_arch): Likewise.
+	* frame-unwind.h (frame_prev_arch_ftype): New type.
+	(struct frame_unwind): New member prev_arch.
+	* frame.c (struct frame_info): New member prev_arch.
+	(frame_unwind_arch): New function.
+	(frame_unwind_caller_arch): Likewise..
+	(get_frame_arch): Reimplement in terms of frame_unwind_arch.
+	* sentinel-frame.c (sentinel_frame_prev_arch): New function.
+	(sentinel_frame_unwinder): Install it.
+
+	* frame.c (frame_pc_unwind): Use frame_unwind_arch instead
+	of get_frame_arch.
+	(frame_unwind_register_value): Likewise.
+	(frame_unwind_register_signed): Likewise.
+	(frame_unwind_register_unsigned): Likewise.
+	* frame-unwind.c (frame_unwind_got_optimized): Likewise.
+	(frame_unwind_got_register): Likewise.
+	(frame_unwind_got_constant): Likewise.
+	(frame_unwind_got_bytes): Likewise.
+	(frame_unwind_got_address): Likewise.
+
+	* frame.h (enum frame_type): New value ARCH_FRAME.
+	* frame.c (fprint_frame_type): Handle ARCH_FRAME.
+	* stack.c (print_frame_info): Likewise.
+
 2009-07-02  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* target.h (struct target_ops): New member to_thread_architecture.

gdb/frame-unwind.c

@@ -129,7 +129,7 @@ default_frame_sniffer (const struct frame_unwind *self,
 struct value *
 frame_unwind_got_optimized (struct frame_info *frame, int regnum)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
+  struct gdbarch *gdbarch = frame_unwind_arch (frame);
   struct value *reg_val;
 
   reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
@@ -152,7 +152,7 @@ frame_unwind_got_register (struct frame_info *frame, int regnum, int new_regnum)
 struct value *
 frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
+  struct gdbarch *gdbarch = frame_unwind_arch (frame);
 
   return value_at_lazy (register_type (gdbarch, regnum), addr);
 }
@@ -164,7 +164,7 @@ struct value *
 frame_unwind_got_constant (struct frame_info *frame, int regnum,
 			   ULONGEST val)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
+  struct gdbarch *gdbarch = frame_unwind_arch (frame);
   struct value *reg_val;
 
   reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
@@ -176,7 +176,7 @@ frame_unwind_got_constant (struct frame_info *frame, int regnum,
 struct value *
 frame_unwind_got_bytes (struct frame_info *frame, int regnum, gdb_byte *buf)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
+  struct gdbarch *gdbarch = frame_unwind_arch (frame);
   struct value *reg_val;
 
   reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
@@ -192,7 +192,7 @@ struct value *
 frame_unwind_got_address (struct frame_info *frame, int regnum,
 			  CORE_ADDR addr)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
+  struct gdbarch *gdbarch = frame_unwind_arch (frame);
   struct value *reg_val;
 
   reg_val = value_zero (register_type (gdbarch, regnum), not_lval);

gdb/frame-unwind.h

@@ -121,6 +121,13 @@ typedef struct value * (frame_prev_register_ftype)
 typedef void (frame_dealloc_cache_ftype) (struct frame_info *self,
 					  void *this_cache);
 
+/* Assuming the frame chain: (outer) prev <-> this <-> next (inner);
+   use THIS frame, and implicitly the NEXT frame's register unwind
+   method, return PREV frame's architecture.  */
+
+typedef struct gdbarch *(frame_prev_arch_ftype) (struct frame_info *this_frame,
+						 void **this_prologue_cache);
+
 struct frame_unwind
 {
   /* The frame's type.  Should this instead be a collection of
@@ -133,6 +140,7 @@ struct frame_unwind
   const struct frame_data *unwind_data;
   frame_sniffer_ftype *sniffer;
   frame_dealloc_cache_ftype *dealloc_cache;
+  frame_prev_arch_ftype *prev_arch;
 };
 
 /* Register a frame unwinder, _prepending_ it to the front of the

gdb/frame.c

@@ -78,6 +78,13 @@ struct frame_info
   void *prologue_cache;
   const struct frame_unwind *unwind;
 
+  /* Cached copy of the previous frame's architecture.  */
+  struct
+  {
+    int p;
+    struct gdbarch *arch;
+  } prev_arch;
+
   /* Cached copy of the previous frame's resume address.  */
   struct {
     int p;
@@ -201,6 +208,9 @@ fprint_frame_type (struct ui_file *file, enum frame_type type)
     case SIGTRAMP_FRAME:
       fprintf_unfiltered (file, "SIGTRAMP_FRAME");
       return;
+    case ARCH_FRAME:
+      fprintf_unfiltered (file, "ARCH_FRAME");
+      return;
     default:
       fprintf_unfiltered (file, "<unknown type>");
       return;
@@ -535,7 +545,7 @@ frame_unwind_pc (struct frame_info *this_frame)
   if (!this_frame->prev_pc.p)
     {
       CORE_ADDR pc;
-      if (gdbarch_unwind_pc_p (get_frame_arch (this_frame)))
+      if (gdbarch_unwind_pc_p (frame_unwind_arch (this_frame)))
 	{
 	  /* The right way.  The `pure' way.  The one true way.  This
 	     method depends solely on the register-unwind code to
@@ -553,7 +563,7 @@ frame_unwind_pc (struct frame_info *this_frame)
 	     frame.  This is all in stark contrast to the old
 	     FRAME_SAVED_PC which would try to directly handle all the
 	     different ways that a PC could be unwound.  */
-	  pc = gdbarch_unwind_pc (get_frame_arch (this_frame), this_frame);
+	  pc = gdbarch_unwind_pc (frame_unwind_arch (this_frame), this_frame);
 	}
       else
 	internal_error (__FILE__, __LINE__, _("No unwind_pc method"));
@@ -732,17 +742,18 @@ get_frame_register (struct frame_info *frame,
 struct value *
 frame_unwind_register_value (struct frame_info *frame, int regnum)
 {
+  struct gdbarch *gdbarch;
   struct value *value;
 
   gdb_assert (frame != NULL);
+  gdbarch = frame_unwind_arch (frame);
 
   if (frame_debug)
     {
       fprintf_unfiltered (gdb_stdlog, "\
 { frame_unwind_register_value (frame=%d,regnum=%d(%s),...) ",
 			  frame->level, regnum,
-			  user_reg_map_regnum_to_name
+			  user_reg_map_regnum_to_name (gdbarch, regnum));
-			    (get_frame_arch (frame), regnum));
     }
 
   /* Find the unwinder.  */
@@ -777,7 +788,7 @@ frame_unwind_register_value (struct frame_info *frame, int regnum)
 
 	      fprintf_unfiltered (gdb_stdlog, " bytes=");
 	      fprintf_unfiltered (gdb_stdlog, "[");
-	      for (i = 0; i < register_size (get_frame_arch (frame), regnum); i++)
+	      for (i = 0; i < register_size (gdbarch, regnum); i++)
 		fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
 	      fprintf_unfiltered (gdb_stdlog, "]");
 	    }
@@ -800,7 +811,7 @@ frame_unwind_register_signed (struct frame_info *frame, int regnum)
 {
   gdb_byte buf[MAX_REGISTER_SIZE];
   frame_unwind_register (frame, regnum, buf);
-  return extract_signed_integer (buf, register_size (get_frame_arch (frame),
+  return extract_signed_integer (buf, register_size (frame_unwind_arch (frame),
 						     regnum));
 }
 
@@ -815,7 +826,7 @@ frame_unwind_register_unsigned (struct frame_info *frame, int regnum)
 {
   gdb_byte buf[MAX_REGISTER_SIZE];
   frame_unwind_register (frame, regnum, buf);
-  return extract_unsigned_integer (buf, register_size (get_frame_arch (frame),
+  return extract_unsigned_integer (buf, register_size (frame_unwind_arch (frame),
 						       regnum));
 }
 
@@ -1880,17 +1891,48 @@ safe_frame_unwind_memory (struct frame_info *this_frame,
   return !target_read_memory (addr, buf, len);
 }
 
-/* Architecture method.  */
+/* Architecture methods.  */
 
 struct gdbarch *
 get_frame_arch (struct frame_info *this_frame)
 {
-  /* In the future, this function will return a per-frame
+  return frame_unwind_arch (this_frame->next);
-     architecture instead of current_gdbarch.  Calling the
+}
-     routine with a NULL value of this_frame is a bug!  */
-  gdb_assert (this_frame);
 
-  return current_gdbarch;
+struct gdbarch *
+frame_unwind_arch (struct frame_info *next_frame)
+{
+  if (!next_frame->prev_arch.p)
+    {
+      struct gdbarch *arch;
+
+      if (next_frame->unwind == NULL)
+	next_frame->unwind
+	  = frame_unwind_find_by_frame (next_frame,
+					&next_frame->prologue_cache);
+
+      if (next_frame->unwind->prev_arch != NULL)
+	arch = next_frame->unwind->prev_arch (next_frame,
+					      &next_frame->prologue_cache);
+      else
+	arch = get_frame_arch (next_frame);
+
+      next_frame->prev_arch.arch = arch;
+      next_frame->prev_arch.p = 1;
+      if (frame_debug)
+	fprintf_unfiltered (gdb_stdlog,
+			    "{ frame_unwind_arch (next_frame=%d) -> %s }\n",
+			    next_frame->level,
+			    gdbarch_bfd_arch_info (arch)->printable_name);
+    }
+
+  return next_frame->prev_arch.arch;
+}
+
+struct gdbarch *
+frame_unwind_caller_arch (struct frame_info *next_frame)
+{
+  return frame_unwind_arch (skip_inlined_frames (next_frame));
 }
 
 /* Stack pointer methods.  */

gdb/frame.h

@@ -203,6 +203,8 @@ enum frame_type
   /* In a signal handler, various OSs handle this in various ways.
      The main thing is that the frame may be far from normal.  */
   SIGTRAMP_FRAME,
+  /* Fake frame representing a cross-architecture call.  */
+  ARCH_FRAME,
   /* Sentinel or registers frame.  This frame obtains register values
      direct from the inferior's registers.  */
   SENTINEL_FRAME
@@ -545,9 +547,14 @@ extern int safe_frame_unwind_memory (struct frame_info *this_frame,
 				     CORE_ADDR addr, gdb_byte *buf, int len);
 
 /* Return this frame's architecture.  */
-
 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
 
+/* Return the previous frame's architecture.  */
+extern struct gdbarch *frame_unwind_arch (struct frame_info *frame);
+
+/* Return the previous frame's architecture, skipping inline functions.  */
+extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
+
 
 /* Values for the source flag to be used in print_frame_info_base().  */
 enum print_what

gdb/sentinel-frame.c

@@ -76,11 +76,23 @@ sentinel_frame_this_id (struct frame_info *this_frame,
   internal_error (__FILE__, __LINE__, _("sentinel_frame_this_id called"));
 }
 
+static struct gdbarch *
+sentinel_frame_prev_arch (struct frame_info *this_frame,
+			  void **this_prologue_cache)
+{
+  struct frame_unwind_cache *cache = *this_prologue_cache;
+  return get_regcache_arch (cache->regcache);
+}
+
 const struct frame_unwind sentinel_frame_unwinder =
 {
   SENTINEL_FRAME,
   sentinel_frame_this_id,
-  sentinel_frame_prev_register
+  sentinel_frame_prev_register,
+  NULL,
+  NULL,
+  NULL,
+  sentinel_frame_prev_arch,
 };
 
 const struct frame_unwind *const sentinel_frame_unwind = &sentinel_frame_unwinder;

gdb/stack.c

@@ -522,7 +522,8 @@ print_frame_info (struct frame_info *frame, int print_level,
   int location_print;
 
   if (get_frame_type (frame) == DUMMY_FRAME
-      || get_frame_type (frame) == SIGTRAMP_FRAME)
+      || get_frame_type (frame) == SIGTRAMP_FRAME
+      || get_frame_type (frame) == ARCH_FRAME)
     {
       struct cleanup *uiout_cleanup
 	= make_cleanup_ui_out_tuple_begin_end (uiout, "frame");
@@ -555,6 +556,10 @@ print_frame_info (struct frame_info *frame, int print_level,
 	  annotate_signal_handler_caller ();
           ui_out_field_string (uiout, "func", "<signal handler called>");
         }
+      else if (get_frame_type (frame) == ARCH_FRAME)
+        {
+          ui_out_field_string (uiout, "func", "<cross-architecture call>");
+	}
       ui_out_text (uiout, "\n");
       annotate_frame_end ();