Author: Carl Friedrich Bolz <cfb...@gmx.de>
Branch: hypothesis-apptest
Changeset: r85126:0485618dc84d
Date: 2016-06-13 15:44 +0200
http://bitbucket.org/pypy/pypy/changeset/0485618dc84d/
Log: a hypothesis strategy for randomizing the results of we_are_jitted()
diff --git a/rpython/rlib/jit.py b/rpython/rlib/jit.py
--- a/rpython/rlib/jit.py
+++ b/rpython/rlib/jit.py
@@ -325,12 +325,42 @@
hop.exception_cannot_occur()
return hop.genop('hint', [v, c_hint], resulttype=v.concretetype)
-
def we_are_jitted():
""" Considered as true during tracing and blackholing,
so its consquences are reflected into jitted code """
+ global _hypothesis_data
+ if _hypothesis_data is not None:
+ if _hypothesis_data.data.frozen:
+ # outside of test, reset
+ _hypothesis_data = None
+ else:
+ import hypothesis.strategies as strategies
+ return _hypothesis_data.draw(strategies.booleans())
return False
+def _randomize_we_are_jitted_from(data):
+ global _hypothesis_data
+ _hypothesis_data = data
+ return None
+
+def randomized_we_are_jitted_strategy():
+ """ a Hypothesis strategy to test functions that rely on we_are_jitted().
+ At runtime, we_are_jitted() can either return True of False, in a somewhat
+ hard to predict way. The functionality of the interpreter should never
+ really depend on the value of the returned bool. To test this, hypothesis
+ can be used with this strategy, in the following way:
+
+ @given(randomized_we_are_jitted_strategy())
+ def test_something(_ignored):
+ # in here, we_are_jitted() randomly returns True or False.
+ # the test is run many times to try to make it fail.
+
+ (the implementation, however, is a bit of a hack).
+ """
+ from hypothesis import strategies
+ return strategies.builds(_randomize_we_are_jitted_from, strategies.data())
+
+
_we_are_jitted = CDefinedIntSymbolic('0 /* we are not jitted here */',
default=0)
diff --git a/rpython/rlib/test/test_jit.py b/rpython/rlib/test/test_jit.py
--- a/rpython/rlib/test/test_jit.py
+++ b/rpython/rlib/test/test_jit.py
@@ -5,7 +5,7 @@
from rpython.rlib.jit import (hint, we_are_jitted, JitDriver, elidable_promote,
JitHintError, oopspec, isconstant, conditional_call,
elidable, unroll_safe, dont_look_inside,
- enter_portal_frame, leave_portal_frame)
+ enter_portal_frame, leave_portal_frame, randomized_we_are_jitted_strategy)
from rpython.rlib.rarithmetic import r_uint
from rpython.rtyper.test.tool import BaseRtypingTest
from rpython.rtyper.lltypesystem import lltype
@@ -115,6 +115,32 @@
def f():
pass
+def test_randomized_we_are_jitted():
+ from hypothesis import given
+ def good():
+ if we_are_jitted():
+ return 1
+ return 1
+ counter = [0]
+ def bad():
+ if we_are_jitted():
+ return 2
+ return 1
+ @given(randomized_we_are_jitted_strategy())
+ def test_random_good(_):
+ assert good() == 1
+ test_random_good()
+
+ @given(randomized_we_are_jitted_strategy())
+ def test_random_bad(_):
+ assert bad() == 1
+ try:
+ test_random_bad()
+ except AssertionError:
+ pass
+ else:
+ assert 0, "should have failed!"
+
class TestJIT(BaseRtypingTest):
def test_hint(self):
def f():
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