[binutils-gdb] Make gdb.PendingFrame.read_register handle "user" registers.

[Kevin Buettner]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=33cc7d368f420326606695daafd6292e2779c6af

commit 33cc7d368f420326606695daafd6292e2779c6af
Author: Kevin Buettner <kevinb@redhat.com>
Date:   Tue Sep 27 22:45:19 2016 -0700

    Make gdb.PendingFrame.read_register handle "user" registers.
    
    The C function, pending_framepy_read_register(), which implements
    the python interface gdb.PendingFrame.read_register does not handle
    the so called "user" registers like "pc".  An assertion error is
    triggered due to the user registers having numbers larger than or
    equal to gdbarch_num_regs(gdbarch).
    
    With the VALUE_FRAME_ID tweak in place, the call to
    get_frame_register_value() can simply be replaced by a call to
    value_of_register(), which handles both real registers as well as the
    user registers.
    
    gdb/ChangeLog:
    
    	* python/py-unwind.c (pending_framepy_read_register): Use
    	value_of_register() instead of get_frame_register_value().

Diff:
---
 gdb/ChangeLog          | 5 +++++
 gdb/python/py-unwind.c | 7 ++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index caad792..5b53dad 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2016-11-16  Kevin Buettner  <kevinb@redhat.com>
 
+	* python/py-unwind.c (pending_framepy_read_register): Use
+	value_of_register() instead of get_frame_register_value().
+
+2016-11-16  Kevin Buettner  <kevinb@redhat.com>
+
 	* value.h (VALUE_FRAME_ID): Rename to VALUE_NEXT_FRAME_ID. Update
 	comment.  Create new VALUE_FRAME_ID which is defined in terms of
 	VALUE_NEXT_FRAME_ID.
diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c
index 52184bd..65c705f 100644
--- a/gdb/python/py-unwind.c
+++ b/gdb/python/py-unwind.c
@@ -407,7 +407,12 @@ pending_framepy_read_register (PyObject *self, PyObject *args)
 
   TRY
     {
-      val = get_frame_register_value (pending_frame->frame_info, regnum);
+      /* Fetch the value associated with a register, whether it's
+	 a real register or a so called "user" register, like "pc",
+	 which maps to a real register.  In the past,
+	 get_frame_register_value() was used here, which did not
+	 handle the user register case.  */
+      val = value_of_register (regnum, pending_frame->frame_info);
       if (val == NULL)
         PyErr_Format (PyExc_ValueError,
                       "Cannot read register %d from frame.",