[pypy-svn] r47597 - in pypy/dist/pypy/rpython/lltypesystem: . test

[arigo at codespeak.net]

Author: arigo
Date: Fri Oct 19 17:30:35 2007
New Revision: 47597

Modified:
   pypy/dist/pypy/rpython/lltypesystem/llmemory.py
   pypy/dist/pypy/rpython/lltypesystem/test/test_llmemory.py
Log:
We need support for 'NULL-NULL'.


Modified: pypy/dist/pypy/rpython/lltypesystem/llmemory.py
==============================================================================
--- pypy/dist/pypy/rpython/lltypesystem/llmemory.py	(original)
+++ pypy/dist/pypy/rpython/lltypesystem/llmemory.py	Fri Oct 19 17:30:35 2007
@@ -329,6 +329,11 @@
     def __sub__(self, other):
         if isinstance(other, AddressOffset):
             return self + (-other)
+        if isinstance(other, fakeaddress):
+            if self == other:
+                return 0
+            else:
+                raise TypeError("cannot subtract fakeaddresses in general")
         if other == 0:
             return self
         return NotImplemented

Modified: pypy/dist/pypy/rpython/lltypesystem/test/test_llmemory.py
==============================================================================
--- pypy/dist/pypy/rpython/lltypesystem/test/test_llmemory.py	(original)
+++ pypy/dist/pypy/rpython/lltypesystem/test/test_llmemory.py	Fri Oct 19 17:30:35 2007
@@ -191,6 +191,13 @@
     adr2 += ItemOffset(lltype.Char, -1)
     assert adr1 == adr2
 
+def test_adr_sub():
+    # only (a - a) is supported
+    assert NULL - NULL == 0
+    A = lltype.GcArray(lltype.Char)
+    a = raw_malloc(sizeof(A, 5))
+    assert a - a == 0
+
 def test_cast_subarray_pointer():
     for a in [lltype.malloc(lltype.GcArray(lltype.Signed), 5),
               lltype.malloc(lltype.FixedSizeArray(lltype.Signed, 5),