[PATCH] libstdc++/77645 fix deque and vector xmethods for Python 3

[Jonathan Wakely]

The problem for these xmethods is that in Python 3 division of two
integers produces a float, and GDB then doesn't allow that value
to be used for pointer arithmetic (https://sourceware.org/PR20622).

	PR libstdc++/77645
	* python/libstdcxx/v6/xmethods.py (DequeWorkerBase.__init__)
	(DequeWorkerBase.index, VectorWorkerBase.get): Cast results of
	division to int to work with Python 3.

Tested x86_64-linux, committed to trunk.

I'll fix it for gcc-5 and gcc-6 too.


-------------- next part --------------
commit a1eda07dc44e271ea07c266624b600cbae257b58
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Mon Sep 19 18:02:36 2016 +0100

    libstdc++/77645 fix deque and vector xmethods for Python 3
    
    	PR libstdc++/77645
    	* python/libstdcxx/v6/xmethods.py (DequeWorkerBase.__init__)
    	(DequeWorkerBase.index, VectorWorkerBase.get): Cast results of
    	division to int to work with Python 3.

diff --git a/libstdc++-v3/python/libstdcxx/v6/xmethods.py b/libstdc++-v3/python/libstdcxx/v6/xmethods.py
index 95f9af9..71a5b75 100644
--- a/libstdc++-v3/python/libstdcxx/v6/xmethods.py
+++ b/libstdc++-v3/python/libstdcxx/v6/xmethods.py
@@ -165,7 +165,7 @@ class ArrayMethodsMatcher(gdb.xmethod.XMethodMatcher):
 class DequeWorkerBase(gdb.xmethod.XMethodWorker):
     def __init__(self, val_type):
         self._val_type = val_type
-        self._bufsize = (512 / val_type.sizeof) or 1
+        self._bufsize = int(512 / val_type.sizeof) or 1
 
     def size(self, obj):
         first_node = obj['_M_impl']['_M_start']['_M_node']
@@ -176,7 +176,7 @@ class DequeWorkerBase(gdb.xmethod.XMethodWorker):
 
     def index(self, obj, idx):
         first_node = obj['_M_impl']['_M_start']['_M_node']
-        index_node = first_node + idx / self._bufsize
+        index_node = first_node + int(idx / self._bufsize)
         return index_node[0][idx % self._bufsize]
 
 class DequeEmptyWorker(DequeWorkerBase):
@@ -419,7 +419,7 @@ class VectorWorkerBase(gdb.xmethod.XMethodWorker):
         if self._val_type.code == gdb.TYPE_CODE_BOOL:
             start = obj['_M_impl']['_M_start']['_M_p']
             bit_size = start.dereference().type.sizeof * 8
-            valp = start + index / bit_size
+            valp = start + int(index / bit_size)
             offset = index % bit_size
             return (valp.dereference() & (1 << offset)) > 0
         else: