PR26547: alignof should return ABI alignment, not preferred alignment

Summary:
- Add `UETT_PreferredAlignOf` to account for the difference between `__alignof` and `alignof`
- `AlignOfType` now returns ABI alignment instead of preferred alignment iff clang-abi-compat > 7, and one uses _Alignof or alignof

Patch by Nicole Mazzuca!

Differential Revision: https://reviews.llvm.org/D53207

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@345419 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 0 deletions

diff --git a/test/SemaCXX/align-x86-abi7.cpp b/test/SemaCXX/align-x86-abi7.cpp
new file mode 100644
index 0000000000..3088a13f78
--- /dev/null
+++ b/test/SemaCXX/align-x86-abi7.cpp
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -std=c++11 -triple i386-apple-darwin9 -fsyntax-only -verify -fclang-abi-compat=7 %s
+// expected-no-diagnostics
+
+using size_t = decltype(sizeof(0));
+
+template <typename T, size_t Preferred>
+struct check_alignment {
+  using type = T;
+  static type value;
+
+  static_assert(__alignof__(value) == Preferred, "__alignof__(value) != Preferred");
+  static_assert(__alignof__(type) == Preferred, "__alignof__(type) != Preferred");
+  static_assert(alignof(type) == Preferred, "alignof(type) != Preferred");
+};
+
+// PR3433
+template struct check_alignment<double, 8>;
+template struct check_alignment<long long, 8>;
+template struct check_alignment<unsigned long long, 8>;
+
+// PR6362
+template struct check_alignment<double[3], 8>;
+
+enum big_enum { x = 18446744073709551615ULL };
+template struct check_alignment<big_enum, 8>;