[pypy-svn] r52059 - in pypy/branch/jit-refactoring/pypy/annotation: . test

[arigo at codespeak.net]

Author: arigo
Date: Sun Mar  2 18:28:35 2008
New Revision: 52059

Modified:
   pypy/branch/jit-refactoring/pypy/annotation/binaryop.py
   pypy/branch/jit-refactoring/pypy/annotation/test/test_annrpython.py
Log:
Experimental, to help in translating the rainbow interpreter:
reading from empty lists is not fatal


Modified: pypy/branch/jit-refactoring/pypy/annotation/binaryop.py
==============================================================================
--- pypy/branch/jit-refactoring/pypy/annotation/binaryop.py	(original)
+++ pypy/branch/jit-refactoring/pypy/annotation/binaryop.py	Sun Mar  2 18:28:35 2008
@@ -16,7 +16,7 @@
 from pypy.annotation.model import SomeSingleFloat
 from pypy.annotation.model import unionof, UnionError, set, missing_operation
 from pypy.annotation.model import isdegenerated, TLS
-from pypy.annotation.model import read_can_only_throw
+from pypy.annotation.model import read_can_only_throw, HarmlesslyBlocked
 from pypy.annotation.model import add_knowntypedata, merge_knowntypedata
 from pypy.annotation.model import lltype_to_annotation
 from pypy.annotation.model import SomeGenericCallable
@@ -603,7 +603,10 @@
 
     def getitem((lst1, int2)):
         getbookkeeper().count("list_getitem", int2)
-        return lst1.listdef.read_item()
+        s_item = lst1.listdef.read_item()
+        if isinstance(s_item, SomeImpossibleValue):
+            raise HarmlesslyBlocked("getitem on an empty list")
+        return s_item
     getitem.can_only_throw = []
 
     getitem_key = getitem

Modified: pypy/branch/jit-refactoring/pypy/annotation/test/test_annrpython.py
==============================================================================
--- pypy/branch/jit-refactoring/pypy/annotation/test/test_annrpython.py	(original)
+++ pypy/branch/jit-refactoring/pypy/annotation/test/test_annrpython.py	Sun Mar  2 18:28:35 2008
@@ -3040,6 +3040,25 @@
 
         a.build_types(f, [str])
 
+    def test_empty_list_blocks_harmlessly(self):
+        class X:
+            pass
+        x = X()
+        x.foobar = []
+        def f(n):
+            if n < 0:
+                # this example shows up in cases where the next line is
+                # really unreachable, but in ways that the annotator cannot
+                # figure out
+                return x.foobar[~n]
+            else:
+                return 42
+
+        a = self.RPythonAnnotator()
+        s = a.build_types(f, [int])
+        assert s.const == 42
+
+
 def g(n):
     return [0,1,2,n]