[pypy-commit] pypy default: Add another test for the graph analyzer's handling of recursion.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r59450:be3ab719fba2
Date: 2012-12-15 23:20 +0100
http://bitbucket.org/pypy/pypy/changeset/be3ab719fba2/

Log:	Add another test for the graph analyzer's handling of recursion.

diff --git a/pypy/translator/backendopt/test/test_canraise.py b/pypy/translator/backendopt/test/test_canraise.py
--- a/pypy/translator/backendopt/test/test_canraise.py
+++ b/pypy/translator/backendopt/test/test_canraise.py
@@ -65,6 +65,27 @@
         result = ra.can_raise(fgraph.startblock.exits[0].target.operations[-1]) # the call to g
         assert result
 
+    def test_recursive_cannot_raise(self):
+        # intentionally don't insert stack checks.  The goal is to verify
+        # the graph analyzer, which should return "no" on such a recursion.
+        def g(x):
+            return f(x)
+
+        def f(x):
+            if x:
+                if x % 2:
+                    return x
+                return 42
+            return g(x - 1)
+
+        t, ra = self.translate(f, [int])
+        ggraph = graphof(t, g)
+        fgraph = graphof(t, f)
+        result = ra.can_raise(ggraph.startblock.operations[-1]) # the call to f
+        assert not result
+        result = ra.can_raise(fgraph.startblock.exits[0].target.operations[-1]) # the call to g
+        assert not result
+
     def test_can_raise_exception(self):
         def g():
             raise ValueError