1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: no-exceptions
10 // UNSUPPORTED: c++98, c++03
11 
12 // The system unwind.h on OS X provides an incorrectly aligned _Unwind_Exception
13 // type. That causes these tests to fail. This XFAIL is my best attempt at
14 // working around this failure.
15 // XFAIL: darwin && libcxxabi-has-system-unwinder
16 
17 // Test that the address of the exception object is properly aligned as required
18 // by the relevant ABI
19 
20 #include <cstdint>
21 #include <cassert>
22 #include <__cxxabi_config.h>
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(_LIBCXXABI_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