[pypy-commit] pypy faster-rstruct-2: add a new test flag to disallow fast paths

[antocuni]

Author: Antonio Cuni <anto.cuni at gmail.com>
Branch: faster-rstruct-2
Changeset: r91332:274be07c41af
Date: 2017-05-18 12:01 +0200
http://bitbucket.org/pypy/pypy/changeset/274be07c41af/

Log:	add a new test flag to disallow fast paths

diff --git a/rpython/rlib/rstruct/standardfmttable.py b/rpython/rlib/rstruct/standardfmttable.py
--- a/rpython/rlib/rstruct/standardfmttable.py
+++ b/rpython/rlib/rstruct/standardfmttable.py
@@ -19,6 +19,7 @@
 
 USE_FASTPATH = True    # set to False by some tests
 ALLOW_SLOWPATH = True  # set to False by some tests
+ALLOW_FASTPATH = True  # set to False by some tests
 
 native_is_bigendian = struct.pack("=i", 1) == struct.pack(">i", 1)
 native_is_ieee754 = float.__getformat__('double').startswith('IEEE')
@@ -39,6 +40,8 @@
             pos % size != 0):
             raise CannotWrite
         #
+        if not ALLOW_FASTPATH:
+            raise ValueError("fastpath not allowed :(")
         # typed_write() might raise CannotWrite
         fmtiter.wbuf.typed_write(TYPE, fmtiter.pos, value)
         fmtiter.advance(size)
@@ -208,6 +211,8 @@
             # *and* it is not supported.
             raise CannotRead
         #
+        if not ALLOW_FASTPATH:
+            raise ValueError("fastpath not allowed :(")
         # typed_read does not do any bound check, so we must call it only if
         # we are sure there are at least "size" bytes to read
         if fmtiter.can_advance(size):
diff --git a/rpython/rlib/rstruct/test/test_pack.py b/rpython/rlib/rstruct/test/test_pack.py
--- a/rpython/rlib/rstruct/test/test_pack.py
+++ b/rpython/rlib/rstruct/test/test_pack.py
@@ -44,14 +44,17 @@
 
     USE_FASTPATH = True
     ALLOW_SLOWPATH = True
+    ALLOW_FASTPATH = True
     
     def setup_method(self, meth):
         standardfmttable.USE_FASTPATH = self.USE_FASTPATH
         standardfmttable.ALLOW_SLOWPATH = self.ALLOW_SLOWPATH
+        standardfmttable.ALLOW_FASTPATH = self.ALLOW_FASTPATH
 
     def teardown_method(self, meth):
         standardfmttable.USE_FASTPATH = True
         standardfmttable.ALLOW_SLOWPATH = True
+        standardfmttable.ALLOW_FASTPATH = True
 
     def mypack(self, fmt, value):
         size = struct.calcsize(fmt)
@@ -94,6 +97,16 @@
         expected = struct.pack('i', 42)
         assert self.mypack('i', 42) == expected
 
+class TestAllowFastPath(PackSupport):
+    ALLOW_FASTPATH = False
+    bigendian = nativefmttable.native_is_bigendian
+    fmttable = standardfmttable.standard_fmttable
+
+    def test_fastpath_not_allowed(self):
+        # we are using a native endianess but ALLOW_FASTPATH is False, so
+        # the following MUST raise
+        pytest.raises(ValueError, "self.mypack('i', 42)")
+
 
 class BaseTestPack(PackSupport):