Author: David Schneider <[email protected]>
Branch:
Changeset: r44838:1a44e52c715b
Date: 2011-06-08 19:11 +0200
http://bitbucket.org/pypy/pypy/changeset/1a44e52c715b/
Log: (arigo, bivab) add checks to shift operations that they do not get a
shift count that is out of range, at least for C. If you do this in
C you get undefined behaviour.
diff --git a/pypy/translator/c/genc.py b/pypy/translator/c/genc.py
--- a/pypy/translator/c/genc.py
+++ b/pypy/translator/c/genc.py
@@ -900,8 +900,9 @@
print >> f, '}'
def commondefs(defines):
- from pypy.rlib.rarithmetic import LONG_BIT
+ from pypy.rlib.rarithmetic import LONG_BIT, LONGLONG_BIT
defines['PYPY_LONG_BIT'] = LONG_BIT
+ defines['PYPY_LONGLONG_BIT'] = LONGLONG_BIT
def add_extra_files(eci):
srcdir = py.path.local(autopath.pypydir).join('translator', 'c', 'src')
diff --git a/pypy/translator/c/src/int.h b/pypy/translator/c/src/int.h
--- a/pypy/translator/c/src/int.h
+++ b/pypy/translator/c/src/int.h
@@ -73,15 +73,28 @@
/* NB. shifting has same limitations as C: the shift count must be
>= 0 and < LONG_BITS. */
-#define OP_INT_RSHIFT(x,y,r) r = Py_ARITHMETIC_RIGHT_SHIFT(long, x, y)
-#define OP_UINT_RSHIFT(x,y,r) r = (x) >> (y)
-#define OP_LLONG_RSHIFT(x,y,r) r = Py_ARITHMETIC_RIGHT_SHIFT(PY_LONG_LONG,x,y)
-#define OP_ULLONG_RSHIFT(x,y,r) r = (x) >> (y)
+#define CHECK_SHIFT_RANGE(y, bits) RPyAssert(y >= 0 && y < bits, \
+ "The shift count is outside of the supported range")
-#define OP_INT_LSHIFT(x,y,r) r = (x) << (y)
-#define OP_UINT_LSHIFT(x,y,r) r = (x) << (y)
-#define OP_LLONG_LSHIFT(x,y,r) r = (x) << (y)
-#define OP_ULLONG_LSHIFT(x,y,r) r = (x) << (y)
+
+#define OP_INT_RSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONG_BIT); \
+ r =
Py_ARITHMETIC_RIGHT_SHIFT(long, x, (y))
+#define OP_UINT_RSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONG_BIT); \
+ r = (x) >> (y)
+#define OP_LLONG_RSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONGLONG_BIT); \
+ r =
Py_ARITHMETIC_RIGHT_SHIFT(PY_LONG_LONG,x, (y))
+#define OP_ULLONG_RSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONGLONG_BIT); \
+ r = (x) >> (y)
+
+
+#define OP_INT_LSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONG_BIT); \
+ r = (x) << (y)
+#define OP_UINT_LSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONG_BIT); \
+ r = (x) << (y)
+#define OP_LLONG_LSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONGLONG_BIT); \
+ r = (x) << (y)
+#define OP_ULLONG_LSHIFT(x,y,r) CHECK_SHIFT_RANGE(y, PYPY_LONGLONG_BIT); \
+ r = (x) << (y)
#define OP_INT_LSHIFT_OVF(x,y,r) \
OP_INT_LSHIFT(x,y,r); \
diff --git a/pypy/translator/c/test/test_standalone.py
b/pypy/translator/c/test/test_standalone.py
--- a/pypy/translator/c/test/test_standalone.py
+++ b/pypy/translator/c/test/test_standalone.py
@@ -596,6 +596,42 @@
# The traceback stops at f() because it's the first function that
# captures the AssertionError, which makes the program abort.
+ def test_int_lshift_too_large(self):
+ from pypy.rlib.rarithmetic import LONG_BIT, LONGLONG_BIT
+ def entry_point(argv):
+ a = int(argv[1])
+ b = int(argv[2])
+ print a << b
+ return 0
+
+ t, cbuilder = self.compile(entry_point, debug=True)
+ out = cbuilder.cmdexec("10 2", expect_crash=False)
+ assert out.strip() == str(10 << 2)
+ cases = [-4, LONG_BIT, LONGLONG_BIT]
+ for x in cases:
+ out, err = cbuilder.cmdexec("%s %s" % (1, x), expect_crash=True)
+ lines = err.strip()
+ assert 'The shift count is outside of the supported range' in lines
+
+ def test_llong_rshift_too_large(self):
+ from pypy.rlib.rarithmetic import LONG_BIT, LONGLONG_BIT
+ def entry_point(argv):
+ a = r_longlong(int(argv[1]))
+ b = r_longlong(int(argv[2]))
+ print a >> b
+ return 0
+
+ t, cbuilder = self.compile(entry_point, debug=True)
+ out = cbuilder.cmdexec("10 2", expect_crash=False)
+ assert out.strip() == str(10 >> 2)
+ out = cbuilder.cmdexec("%s %s" % (-42, LONGLONG_BIT - 1),
expect_crash=False)
+ assert out.strip() == '-1'
+ cases = [-4, LONGLONG_BIT]
+ for x in cases:
+ out, err = cbuilder.cmdexec("%s %s" % (1, x), expect_crash=True)
+ lines = err.strip()
+ assert 'The shift count is outside of the supported range' in lines
+
def test_ll_assert_error_debug(self):
def entry_point(argv):
ll_assert(len(argv) != 1, "foobar")
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