Re: [RFC][Python] gdbpy_frame_stop_reason_string bug

[Kevin Pouget <kevin.pouget@gmail.com>]

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On Fri, Oct 14, 2011 at 4:21 PM, Tom Tromey <tromey@redhat.com> wrote:
>>>>>> "Kevin" == Kevin Pouget <kevin.pouget@gmail.com> writes:
>
> Kevin> include/gdb/
> Kevin> 2011-10-14  Kevin Pouget  <kevin.pouget@st.com>
> Kevin>  * unwind_stop_reasons.def: New file.
>
> Don't put it in include/gdb.  That is too obscure.  Just put this file
> directly in the gdb directory along with everything else.
>
> Tom

ok, I did it based on signals.def, but it's indeed not relevant here.

I've updated the patch

Thanks,

Kevin

2011-10-14  Kevin Pouget  <kevin.pouget@st.com>

	* frame.c (frame_stop_reason_string): Rewrite using
	unwind_stop_reasons.def.
	* frame.h (enum unwind_stop_reason): Likewise.
	* python/py-frame.c (gdbpy_initialize_frames): Likewise.
	(gdbpy_frame_stop_reason_string): Use new enum unwind_stop_reason
	constants for bound-checking.
	* unwind_stop_reasons.def: New file.

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From eae545861d1b1cbfe28bbc729c72cdd99758e85b Mon Sep 17 00:00:00 2001
From: Kevin Pouget <kevin.pouget@st.com>
Date: Fri, 14 Oct 2011 10:03:52 +0200
Subject: [PATCH] Move unwind reasons to an external .def file

---
 gdb/frame.c                 |   20 ++---------
 gdb/frame.h                 |   51 +++++----------------------
 gdb/python/py-frame.c       |   19 +++-------
 gdb/unwind_stop_reasons.def |   79 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 99 insertions(+), 70 deletions(-)
 create mode 100644 gdb/unwind_stop_reasons.def

diff --git a/gdb/frame.c b/gdb/frame.c
index 5824020..e5e442a 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -2351,23 +2351,11 @@ frame_stop_reason_string (enum unwind_stop_reason reason)
 {
   switch (reason)
     {
-    case UNWIND_NULL_ID:
-      return _("unwinder did not report frame ID");
+#define SET(name, description) \
+    case name: return _(description);
+#include "unwind_stop_reasons.def"
+#undef SET
 
-    case UNWIND_UNAVAILABLE:
-      return _("Not enough registers or memory available to unwind further");
-
-    case UNWIND_INNER_ID:
-      return _("previous frame inner to this frame (corrupt stack?)");
-
-    case UNWIND_SAME_ID:
-      return _("previous frame identical to this frame (corrupt stack?)");
-
-    case UNWIND_NO_SAVED_PC:
-      return _("frame did not save the PC");
-
-    case UNWIND_NO_REASON:
-    case UNWIND_FIRST_ERROR:
     default:
       internal_error (__FILE__, __LINE__,
 		      "Invalid frame stop reason");
diff --git a/gdb/frame.h b/gdb/frame.h
index f5866bd..514393b 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -446,47 +446,16 @@ extern struct address_space *get_frame_address_space (struct frame_info *);
 
 enum unwind_stop_reason
   {
-    /* No particular reason; either we haven't tried unwinding yet,
-       or we didn't fail.  */
-    UNWIND_NO_REASON,
-
-    /* The previous frame's analyzer returns an invalid result
-       from this_id.
-
-       FIXME drow/2006-08-16: This is how GDB used to indicate end of
-       stack.  We should migrate to a model where frames always have a
-       valid ID, and this becomes not just an error but an internal
-       error.  But that's a project for another day.  */
-    UNWIND_NULL_ID,
-
-    /* This frame is the outermost.  */
-    UNWIND_OUTERMOST,
-
-    /* All the conditions after this point are considered errors;
-       abnormal stack termination.  If a backtrace stops for one
-       of these reasons, we'll let the user know.  This marker
-       is not a valid stop reason.  */
-    UNWIND_FIRST_ERROR,
-
-    /* Can't unwind further, because that would require knowing the
-       values of registers or memory that haven't been collected.  */
-    UNWIND_UNAVAILABLE,
-
-    /* This frame ID looks like it ought to belong to a NEXT frame,
-       but we got it for a PREV frame.  Normally, this is a sign of
-       unwinder failure.  It could also indicate stack corruption.  */
-    UNWIND_INNER_ID,
-
-    /* This frame has the same ID as the previous one.  That means
-       that unwinding further would almost certainly give us another
-       frame with exactly the same ID, so break the chain.  Normally,
-       this is a sign of unwinder failure.  It could also indicate
-       stack corruption.  */
-    UNWIND_SAME_ID,
-
-    /* The frame unwinder didn't find any saved PC, but we needed
-       one to unwind further.  */
-    UNWIND_NO_SAVED_PC,
+#define SET(name, description) name,
+#define FIRST_ENTRY(name) UNWIND_FIRST = name,
+#define LAST_ENTRY(name) UNWIND_LAST = name,
+#define FIRST_ERROR(name) UNWIND_FIRST_ERROR = name,
+
+#include "unwind_stop_reasons.def"
+#undef SET
+#undef FIRST_ENTRY
+#undef LAST_ENTRY
+#undef FIRST_ERROR
   };
 
 /* Return the reason why we can't unwind past this frame.  */
diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index 75aa44e..854faa0 100644
--- a/gdb/python/py-frame.c
+++ b/gdb/python/py-frame.c
@@ -542,7 +542,7 @@ gdbpy_frame_stop_reason_string (PyObject *self, PyObject *args)
   if (!PyArg_ParseTuple (args, "i", &reason))
     return NULL;
 
-  if (reason < 0 || reason > UNWIND_NO_SAVED_PC)
+  if (reason < UNWIND_FIRST || reason > UNWIND_LAST)
     {
       PyErr_SetString (PyExc_ValueError, 
 		       _("Invalid frame stop reason."));
@@ -599,18 +599,11 @@ gdbpy_initialize_frames (void)
   PyModule_AddIntConstant (gdb_module, "SIGTRAMP_FRAME", SIGTRAMP_FRAME);
   PyModule_AddIntConstant (gdb_module, "ARCH_FRAME", ARCH_FRAME);
   PyModule_AddIntConstant (gdb_module, "SENTINEL_FRAME", SENTINEL_FRAME);
-  PyModule_AddIntConstant (gdb_module,
-			   "FRAME_UNWIND_NO_REASON", UNWIND_NO_REASON);
-  PyModule_AddIntConstant (gdb_module,
-			   "FRAME_UNWIND_NULL_ID", UNWIND_NULL_ID);
-  PyModule_AddIntConstant (gdb_module,
-			   "FRAME_UNWIND_FIRST_ERROR", UNWIND_FIRST_ERROR);
-  PyModule_AddIntConstant (gdb_module,
-			   "FRAME_UNWIND_INNER_ID", UNWIND_INNER_ID);
-  PyModule_AddIntConstant (gdb_module,
-			   "FRAME_UNWIND_SAME_ID", UNWIND_SAME_ID);
-  PyModule_AddIntConstant (gdb_module,
-			   "FRAME_UNWIND_NO_SAVED_PC", UNWIND_NO_SAVED_PC);
+
+#define SET(name, description) \
+  PyModule_AddIntConstant (gdb_module, "FRAME_"#name, name);
+#include "../unwind_stop_reasons.def"
+#undef SET
 
   Py_INCREF (&frame_object_type);
   PyModule_AddObject (gdb_module, "Frame", (PyObject *) &frame_object_type);
diff --git a/gdb/unwind_stop_reasons.def b/gdb/unwind_stop_reasons.def
new file mode 100644
index 0000000..f628aae
--- /dev/null
+++ b/gdb/unwind_stop_reasons.def
@@ -0,0 +1,79 @@
+/* Copyright 2011 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Reasons why frames could not be further unwound
+   SET (name, description)
+  
+   After this reason name, all reasons should be considered errors;
+   i.e.: abnormal stack termination.
+   FIRST_ERROR (name)  
+   
+   First and Last reason defined
+   FIRST_ENTRY (name)
+   LAST_ENTRY (name)  */
+
+#ifdef SET
+/* No particular reason; either we haven't tried unwinding yet, 
+   or we didn't fail.  */
+SET (UNWIND_NO_REASON, "No reason")
+
+/* The previous frame's analyzer returns an invalid result
+   from this_id.
+
+   FIXME drow/2006-08-16: This is how GDB used to indicate end of
+   stack.  We should migrate to a model where frames always have a
+   valid ID, and this becomes not just an error but an internal
+   error.  But that's a project for another day.  */
+SET (UNWIND_NULL_ID, "unwinder did not report frame ID")
+
+/* This frame is the outermost.  */
+SET (UNWIND_OUTERMOST, "outermost")
+
+/* Can't unwind further, because that would require knowing the
+   values of registers or memory that haven't been collected.  */
+SET (UNWIND_UNAVAILABLE, "Not enough registers or memory available to unwind further")
+
+/* This frame ID looks like it ought to belong to a NEXT frame,
+   but we got it for a PREV frame.  Normally, this is a sign of
+   unwinder failure.  It could also indicate stack corruption.  */
+SET (UNWIND_INNER_ID, "previous frame inner to this frame (corrupt stack?)")
+
+/* This frame has the same ID as the previous one.  That means
+   that unwinding further would almost certainly give us another
+   frame with exactly the same ID, so break the chain.  Normally,
+   this is a sign of unwinder failure.  It could also indicate
+   stack corruption.  */
+SET (UNWIND_SAME_ID, "previous frame identical to this frame (corrupt stack?)")
+
+/* The frame unwinder didn't find any saved PC, but we needed
+   one to unwind further.  */
+SET (UNWIND_NO_SAVED_PC, "frame did not save the PC")
+
+#endif /* SET */
+
+
+#ifdef FIRST_ERROR
+FIRST_ERROR (UNWIND_UNAVAILABLE)
+#endif
+
+#ifdef FIRST_ENTRY
+FIRST_ENTRY (UNWIND_NO_REASON)
+#endif
+
+#ifdef LAST_ENTRY
+LAST_ENTRY (UNWIND_NO_SAVED_PC)
+#endif
-- 
1.7.6.4