[pypy-commit] pypy ffi-backend: Next test

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: ffi-backend
Changeset: r55773:441a98f9da1e
Date: 2012-06-23 12:35 +0200
http://bitbucket.org/pypy/pypy/changeset/441a98f9da1e/

Log:	Next test

diff --git a/pypy/module/_ffi_backend/cdataobj.py b/pypy/module/_ffi_backend/cdataobj.py
--- a/pypy/module/_ffi_backend/cdataobj.py
+++ b/pypy/module/_ffi_backend/cdataobj.py
@@ -112,6 +112,28 @@
     def add(self, w_other):
         return self._add_or_sub(w_other, +1)
 
+    def sub(self, w_other):
+        space = self.space
+        ob = space.interpclass_w(w_other)
+        if isinstance(ob, W_CData):
+            from pypy.module._ffi_backend import ctypeobj
+            ct = ob.ctype
+            if isinstance(ct, ctypeobj.W_CTypeArray):
+                ct = ct.ctptr
+            #
+            if (ct is not self.ctype or
+                   not isinstance(ct, ctypeobj.W_CTypePointer) or
+                   ct.ctitem.size <= 0):
+                raise operationerrfmt(space.w_TypeError,
+                    "cannot subtract cdata '%s' and cdata '%s'",
+                    self.ctype.name, ct.name)
+            #
+            diff = (rffi.cast(lltype.Signed, self._cdata) -
+                    rffi.cast(lltype.Signed, ob._cdata)) // ct.ctitem.size
+            return space.wrap(diff)
+        #
+        return self._add_or_sub(w_other, -1)
+
 ##    def read_raw_signed_data(self):
 ##        result = misc.read_raw_signed_data(self._cdata, self.ctype.size)
 ##        keepalive_until_here(self)
@@ -191,5 +213,6 @@
     __getitem__ = interp2app(W_CData.getitem),
     __setitem__ = interp2app(W_CData.setitem),
     __add__ = interp2app(W_CData.add),
+    __sub__ = interp2app(W_CData.sub),
     )
 W_CData.typedef.acceptable_as_base_class = False
diff --git a/pypy/module/_ffi_backend/test/_backend_test_c.py b/pypy/module/_ffi_backend/test/_backend_test_c.py
--- a/pypy/module/_ffi_backend/test/_backend_test_c.py
+++ b/pypy/module/_ffi_backend/test/_backend_test_c.py
@@ -343,6 +343,22 @@
     assert type(a[0][0]) is int
     assert type((a[0] + 0)[0]) is int
 
+def test_array_sub():
+    BInt = new_primitive_type("int")
+    BArray = new_array_type(new_pointer_type(BInt), 5)   # int[5]
+    a = newp(BArray, None)
+    p = a + 1
+    assert p - a == 1
+    assert p - (a+0) == 1
+    assert a == (p - 1)
+    BPtr = new_pointer_type(new_primitive_type("short"))
+    q = newp(BPtr, None)
+    py.test.raises(TypeError, "p - q")
+    py.test.raises(TypeError, "q - p")
+    py.test.raises(TypeError, "a - q")
+    e = py.test.raises(TypeError, "q - a")
+    assert str(e.value) == "cannot subtract cdata 'short *' and cdata 'int *'"
+
 def test_cast_primitive_from_cdata():
     p = new_primitive_type("int")
     n = cast(p, cast(p, -42))