split functionality into pystack and pystackv commands. The former will

work with core dumps because it avoids calling any Python API routines.  The
latter prints all the local variable values as well as the stack frames but
won't work with core dumps because it relies on _PyObject_Dump to print
variables.

Misc/gdbinit

@@ -43,12 +43,16 @@ define pylocals
     end
 end
 
-# print the current frame
+# print the current frame - verbose
+define pyframev
+    pyframe
+    pylocals
+end
+
 define pyframe
-    set $__fn = PyString_AsString(co->co_filename)
-    set $__n = PyString_AsString(co->co_name)
+    set $__fn = (char *)((PyStringObject *)co->co_filename)->ob_sval
+    set $__n = (char *)((PyStringObject *)co->co_name)->ob_sval
     printf "%s (%d): %s\n",  $__fn, f->f_lineno, $__n
-    pylocals
 end
 
 # Here's a somewhat fragile way to print the entire Python stack from gdb.
@@ -72,3 +76,14 @@ define pystack
     end
     select-frame 0
 end
+
+# print the entire Python call stack - verbose mode
+define pystackv
+    while $pc < Py_Main || $pc > Py_GetArgcArgv
+        if $pc > PyEval_EvalFrame && $pc < PyEval_EvalCodeEx
+	    pyframev
+        end
+        up-silently 1
+    end
+    select-frame 0
+end