[pypy-commit] cffi default: Failing tests for issue #82.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r1257:5494afe611a2
Date: 2013-05-30 18:16 +0200
http://bitbucket.org/cffi/cffi/changeset/5494afe611a2/

Log:	Failing tests for issue #82.

diff --git a/testing/test_ffi_backend.py b/testing/test_ffi_backend.py
--- a/testing/test_ffi_backend.py
+++ b/testing/test_ffi_backend.py
@@ -1,4 +1,4 @@
-import py
+import py, sys
 from testing import backend_tests, test_function, test_ownlib
 from cffi import FFI
 import _cffi_backend
@@ -36,3 +36,52 @@
         assert ffi.from_handle(p) is o
         assert ffi.from_handle(ffi.cast("char *", p)) is o
         py.test.raises(RuntimeError, ffi.from_handle, ffi.NULL)
+
+
+class TestBitfield:
+    def check(self, source, expected_ofs_y, expected_align, expected_size):
+        # verify the information with gcc
+        if sys.platform != "win32":
+            ffi1 = FFI()
+            ffi1.cdef("static const int Gofs_y, Galign, Gsize;")
+            lib = ffi1.verify("""
+                struct s1 { %s };
+                struct sa { char a; struct s1 b; };
+                #define Gofs_y  offsetof(struct s1, y)
+                #define Galign  offsetof(struct sa, b)
+                #define Gsize   sizeof(struct s1)
+            """ % source)
+            assert lib.Gofs_y == expected_ofs_y
+            assert lib.Galign == expected_align
+            assert lib.Gsize  == expected_size
+        # the real test follows
+        ffi = FFI()
+        ffi.cdef("struct s1 { %s };" % source)
+        assert ffi.offsetof("struct s1", "y") == expected_ofs_y
+        assert ffi.alignof("struct s1") == expected_align
+        assert ffi.sizeof("struct s1") == expected_size
+
+    def test_bitfield_basic(self):
+        self.check("int a; int b:9; int c:20; int y;", 8, 4, 12)
+        self.check("int a; short b:9; short c:7; int y;", 8, 4, 12)
+        self.check("int a; short b:9; short c:9; int y;", 8, 4, 12)
+
+    def test_bitfield_reuse_if_enough_space(self):
+        self.check("char a; int b:9; char y;", 3, 4, 4)
+        self.check("char a; short b:9; char y;", 4, 2, 6)
+
+    def test_bitfield_anonymous_no_align(self):
+        L = FFI().alignof("long long")
+        self.check("char x; int z:1; char y;", 2, 4, 4)
+        self.check("char x; int  :1; char y;", 2, 1, 3)
+        self.check("char x; long long z:48; char y;", 7, L, 8)
+        self.check("char x; long long  :48; char y;", 7, 1, 8)
+        self.check("char x; long long z:56; char y;", 8, L, 8 + L)
+        self.check("char x; long long  :56; char y;", 8, 1, 9)
+        self.check("char x; long long z:57; char y;", L + 8, L, L + 8 + L)
+        self.check("char x; long long  :57; char y;", L + 8, 1, L + 9)
+
+    def test_bitfield_zero(self):
+        L = FFI().alignof("long long")
+        self.check("char x; int :0; char y;", 4, 1, 5)
+        self.check("char x; long long :0; char y;", L, 1, L + 1)