1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // UNSUPPORTED: libcxxabi-no-exceptions
11 // UNSUPPORTED: c++98, c++03
12 
13 // The system unwind.h on OS X provides an incorrectly aligned _Unwind_Exception
14 // type. That causes these tests to fail. This XFAIL is my best attempt at
15 // working around this failure.
16 // XFAIL: darwin && libcxxabi-has-system-unwinder
17 
18 // Test that the address of the exception object is properly aligned as required
19 // by the relevant ABI
20 
21 #include <cstdint>
22 #include <cassert>
23 
24 #include <unwind.h>
25 
26 struct __attribute__((aligned)) AlignedType {};
27 
28 // EHABI  : 8-byte aligned
29 // Itanium: Largest supported alignment for the system
30 #if defined(_LIBUNWIND_ARM_EHABI)
31 #  define EXPECTED_ALIGNMENT 8
32 #else
33 #  define EXPECTED_ALIGNMENT alignof(AlignedType)
34 #endif
35 
36 static_assert(alignof(_Unwind_Exception) == EXPECTED_ALIGNMENT,
37   "_Unwind_Exception is incorrectly aligned. This test is expected to fail");
38 
39 struct MinAligned {  };
40 static_assert(alignof(MinAligned) == 1 && sizeof(MinAligned) == 1, "");
41 
42 int main() {
43   for (int i=0; i < 10; ++i) {
44     try {
45       throw MinAligned{};
46     } catch (MinAligned const& ref) {
47       assert(reinterpret_cast<uintptr_t>(&ref) % EXPECTED_ALIGNMENT == 0);
48     }
49   }
50 }
51