xref: /llvm-project/libcxxabi/test/test_exception_address_alignment.pass.cpp (revision 2da6ce60a5e92e431ea121175f2bc20287cc8ef9)
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++03
11 
12 // The <unwind.h> header provided in the SDK of older Xcodes used to provide
13 // an incorrectly aligned _Unwind_Exception type on non-ARM. That causes these
14 // tests to fail when compiling against such a SDK, or when running against a
15 // system libc++abi that was compiled with an incorrect definition of _Unwind_Exception.
16 // XFAIL: apple-clang-12.0.0 && !target-arm
17 // XFAIL: apple-clang-11 && !target-arm
18 // XFAIL: apple-clang-10 && !target-arm
19 // XFAIL: apple-clang-9 && !target-arm
20 // XFAIL: with_system_cxx_lib=macosx10.12
21 // XFAIL: with_system_cxx_lib=macosx10.11
22 // XFAIL: with_system_cxx_lib=macosx10.10
23 // XFAIL: with_system_cxx_lib=macosx10.9
24 
25 // Test that the address of the exception object is properly aligned as required
26 // by the relevant ABI
27 
28 #include <cstdint>
29 #include <cassert>
30 #include <__cxxabi_config.h>
31 
32 #include <unwind.h>
33 
34 struct __attribute__((aligned)) AlignedType {};
35 
36 // EHABI  : 8-byte aligned
37 // Itanium: Largest supported alignment for the system
38 #if defined(_LIBCXXABI_ARM_EHABI)
39 #  define EXPECTED_ALIGNMENT 8
40 #else
41 #  define EXPECTED_ALIGNMENT alignof(AlignedType)
42 #endif
43 
44 static_assert(alignof(_Unwind_Exception) == EXPECTED_ALIGNMENT,
45   "_Unwind_Exception is incorrectly aligned. This test is expected to fail");
46 
47 struct MinAligned {  };
48 static_assert(alignof(MinAligned) == 1 && sizeof(MinAligned) == 1, "");
49 
50 int main(int, char**) {
51   for (int i=0; i < 10; ++i) {
52     try {
53       throw MinAligned{};
54     } catch (MinAligned const& ref) {
55       assert(reinterpret_cast<uintptr_t>(&ref) % EXPECTED_ALIGNMENT == 0);
56     }
57   }
58 
59   return 0;
60 }
61