[COMMIT PATCH] get_prev_frame, stop_reason != UNWIND_NO_REASON, add frame debug output.

[Pedro Alves <palves at redhat dot com>]

The stop_reason != UNWIND_NO_REASON doesn't currently have "set debug
frame" output.  This patch makes it print the stop_reason enum value
as a string.

gdb/
2013-11-28  Pedro Alves  <palves@redhat.com>

	* frame.c (get_prev_frame_1) <stop_reason != UNWIND_NO_REASON>:
	Add "set debug frame" output.
	(frame_stop_reason_symbol_string): New function.
---
 gdb/ChangeLog |  6 ++++++
 gdb/frame.c   | 33 ++++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b171f00..b15bee9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
 2013-11-28  Pedro Alves  <palves@redhat.com>
 
+	* frame.c (get_prev_frame_1) <stop_reason != UNWIND_NO_REASON>:
+	Add "set debug frame" output.
+	(frame_stop_reason_symbol_string): New function.
+
+2013-11-28  Pedro Alves  <palves@redhat.com>
+
 	* frame-unwind.c (default_frame_unwind_stop_reason): Return
 	UNWIND_OUTERMOST if the frame's ID is outer_frame_id.
 	* frame.c (get_prev_frame_1): Remove outer_frame_id check.
diff --git a/gdb/frame.c b/gdb/frame.c
index df1d218..db94d98 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -48,6 +48,7 @@
 
 static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
 static struct frame_info *get_prev_frame_raw (struct frame_info *this_frame);
+static const char *frame_stop_reason_symbol_string (enum unwind_stop_reason reason);
 
 /* We keep a cache of stack frames, each of which is a "struct
    frame_info".  The innermost one gets allocated (in
@@ -1771,7 +1772,18 @@ get_prev_frame_1 (struct frame_info *this_frame)
 				       &this_frame->prologue_cache);
 
   if (this_frame->stop_reason != UNWIND_NO_REASON)
-    return NULL;
+    {
+      if (frame_debug)
+	{
+	  enum unwind_stop_reason reason = this_frame->stop_reason;
+
+	  fprintf_unfiltered (gdb_stdlog, "-> ");
+	  fprint_frame (gdb_stdlog, NULL);
+	  fprintf_unfiltered (gdb_stdlog, " // %s }\n",
+			      frame_stop_reason_symbol_string (reason));
+	}
+      return NULL;
+    }
 
   /* Check that this frame's ID isn't inner to (younger, below, next)
      the next frame.  This happens when a frame unwind goes backwards.
@@ -2479,6 +2491,25 @@ frame_stop_reason_string (enum unwind_stop_reason reason)
     }
 }
 
+/* Return the enum symbol name of REASON as a string, to use in debug
+   output.  */
+
+static const char *
+frame_stop_reason_symbol_string (enum unwind_stop_reason reason)
+{
+  switch (reason)
+    {
+#define SET(name, description) \
+    case name: return #name;
+#include "unwind_stop_reasons.def"
+#undef SET
+
+    default:
+      internal_error (__FILE__, __LINE__,
+		      "Invalid frame stop reason");
+    }
+}
+
 /* Clean up after a failed (wrong unwinder) attempt to unwind past
    FRAME.  */
 
-- 
1.7.11.7