ADT: Remove AlignedCharArrayUnion, NFC

[dexonsmith]

Summary

Prep commit already migrated users over to std::aligned_union_t; this
just deletes the type / header / test.

[dblaikie]

Sounds good.

(Funny the history of names - AlignOf.h used to contain a device for finding the alignment of a thing - now that thing no longer exists (replaced by the standard alignas) but the header migrated through various alignment related tools to where it is now... )

[dexonsmith]

In D92517#2429727, @dblaikie wrote:

Sounds good.

(Funny the history of names - AlignOf.h used to contain a device for finding the alignment of a thing - now that thing no longer exists (replaced by the standard alignas) but the header migrated through various alignment related tools to where it is now... )

Thanks for the reviews! (this and the others); I'll hold off committing this and others until tomorrow at least to give unexpected bots time to process https://reviews.llvm.org/D92500 (I think that's the only risky one...).

[dexonsmith]

Apparently I didn't build this before; I'd forgotten to delete the line from CMakeLists.txt; may as well get the try bots to build before pushing.

llvm/include/llvm/Support/AlignOf.h

-//===--- AlignOf.h - Portable calculation of type alignment -----*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file defines the AlignedCharArrayUnion class.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_SUPPORT_ALIGNOF_H
-#define LLVM_SUPPORT_ALIGNOF_H
-
-#include <type_traits>
-
-namespace llvm {
-
-/// A suitably aligned and sized character array member which can hold elements
-/// of any type.
-///
-/// These types may be arrays, structs, or any other types. Underneath is a
-/// char buffer member which can be used as suitable storage for a placement
-/// new of any of these types.
-template <typename T, typename... Ts>
-using AlignedCharArrayUnion = std::aligned_union_t<1, T, Ts...>;
-
-} // end namespace llvm
-
-#endif // LLVM_SUPPORT_ALIGNOF_H

llvm/unittests/Support/AlignOfTest.cpp

-//=== - llvm/unittest/Support/AlignOfTest.cpp - Alignment utility tests ---===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifdef _MSC_VER
-// Disable warnings about alignment-based structure padding.
-// This must be above the includes to suppress warnings in included templates.
-#pragma warning(disable:4324)
-#endif
-
-#include "llvm/Support/AlignOf.h"
-#include "llvm/Support/Compiler.h"
-#include "gtest/gtest.h"
-
-using namespace llvm;
-
-namespace {
-// Disable warnings about questionable type definitions.
-// We're testing that even questionable types work with the alignment utilities.
-#ifdef _MSC_VER
-#pragma warning(disable:4584)
-#endif
-
-// Suppress direct base '{anonymous}::S1' inaccessible in '{anonymous}::D9'
-// due to ambiguity warning.
-#ifdef __clang__
-#pragma clang diagnostic ignored "-Wunknown-pragmas"
-#pragma clang diagnostic ignored "-Winaccessible-base"
-#elif ((__GNUC__ * 100) + __GNUC_MINOR__) >= 402
-// Pragma based warning suppression was introduced in GGC 4.2.  Additionally
-// this warning is "enabled by default".  The warning still appears if -Wall is
-// suppressed.  Apparently GCC suppresses it when -w is specifed, which is odd.
-#pragma GCC diagnostic warning "-w"
-#endif
-
-// Define some fixed alignment types to use in these tests.
-struct alignas(1) A1 {};
-struct alignas(2) A2 {};
-struct alignas(4) A4 {};
-struct alignas(8) A8 {};
-
-struct S1 {};
-struct S2 { char a; };
-struct S3 { int x; };
-struct S4 { double y; };
-struct S5 { A1 a1; A2 a2; A4 a4; A8 a8; };
-struct S6 { double f(); };
-struct D1 : S1 {};
-struct D2 : S6 { float g(); };
-struct D3 : S2 {};
-struct D4 : S2 { int x; };
-struct D5 : S3 { char c; };
-struct D6 : S2, S3 {};
-struct D7 : S1, S3 {};
-struct D8 : S1, D4, D5 { double x[2]; };
-struct D9 : S1, D1 { S1 s1; };
-struct V1 { virtual ~V1(); };
-struct V2 { int x; virtual ~V2(); };
-struct V3 : V1 {
-  ~V3() override;
-};
-struct V4 : virtual V2 { int y;
-  ~V4() override;
-};
-struct V5 : V4, V3 { double z;
-  ~V5() override;
-};
-struct V6 : S1 { virtual ~V6(); };
-struct V7 : virtual V2, virtual V6 {
-  ~V7() override;
-};
-struct V8 : V5, virtual V6, V7 { double zz;
-  ~V8() override;
-};
-
-double S6::f() { return 0.0; }
-float D2::g() { return 0.0f; }
-V1::~V1() {}
-V2::~V2() {}
-V3::~V3() {}
-V4::~V4() {}
-V5::~V5() {}
-V6::~V6() {}
-V7::~V7() {}
-V8::~V8() {}
-
-template <typename M> struct T { M m; };
-
-TEST(AlignOfTest, BasicAlignedArray) {
-  EXPECT_LE(1u, alignof(AlignedCharArrayUnion<A1>));
-  EXPECT_LE(2u, alignof(AlignedCharArrayUnion<A2>));
-  EXPECT_LE(4u, alignof(AlignedCharArrayUnion<A4>));
-  EXPECT_LE(8u, alignof(AlignedCharArrayUnion<A8>));
-
-  EXPECT_LE(1u, sizeof(AlignedCharArrayUnion<A1>));
-  EXPECT_LE(2u, sizeof(AlignedCharArrayUnion<A2>));
-  EXPECT_LE(4u, sizeof(AlignedCharArrayUnion<A4>));
-  EXPECT_LE(8u, sizeof(AlignedCharArrayUnion<A8>));
-
-  EXPECT_EQ(1u, (alignof(AlignedCharArrayUnion<A1>)));
-  EXPECT_EQ(2u, (alignof(AlignedCharArrayUnion<A1, A2>)));
-  EXPECT_EQ(4u, (alignof(AlignedCharArrayUnion<A1, A2, A4>)));
-  EXPECT_EQ(8u, (alignof(AlignedCharArrayUnion<A1, A2, A4, A8>)));
-
-  EXPECT_EQ(1u, sizeof(AlignedCharArrayUnion<A1>));
-  EXPECT_EQ(2u, sizeof(AlignedCharArrayUnion<A1, A2>));
-  EXPECT_EQ(4u, sizeof(AlignedCharArrayUnion<A1, A2, A4>));
-  EXPECT_EQ(8u, sizeof(AlignedCharArrayUnion<A1, A2, A4, A8>));
-
-  EXPECT_EQ(1u, (alignof(AlignedCharArrayUnion<A1[1]>)));
-  EXPECT_EQ(2u, (alignof(AlignedCharArrayUnion<A1[2], A2[1]>)));
-  EXPECT_EQ(4u, (alignof(AlignedCharArrayUnion<A1[42], A2[55], A4[13]>)));
-  EXPECT_EQ(8u, (alignof(AlignedCharArrayUnion<A1[2], A2[1], A4, A8>)));
-
-  EXPECT_EQ(1u,  sizeof(AlignedCharArrayUnion<A1[1]>));
-  EXPECT_EQ(2u,  sizeof(AlignedCharArrayUnion<A1[2], A2[1]>));
-  EXPECT_EQ(4u,  sizeof(AlignedCharArrayUnion<A1[3], A2[2], A4>));
-  EXPECT_EQ(16u, sizeof(AlignedCharArrayUnion<A1, A2[3],
-                                              A4[3], A8>));
-
-  // For other tests we simply assert that the alignment of the union mathes
-  // that of the fundamental type and hope that we have any weird type
-  // productions that would trigger bugs.
-  EXPECT_EQ(alignof(T<char>), alignof(AlignedCharArrayUnion<char>));
-  EXPECT_EQ(alignof(T<short>), alignof(AlignedCharArrayUnion<short>));
-  EXPECT_EQ(alignof(T<int>), alignof(AlignedCharArrayUnion<int>));
-  EXPECT_EQ(alignof(T<long>), alignof(AlignedCharArrayUnion<long>));
-  EXPECT_EQ(alignof(T<long long>), alignof(AlignedCharArrayUnion<long long>));
-  EXPECT_EQ(alignof(T<float>), alignof(AlignedCharArrayUnion<float>));
-  EXPECT_EQ(alignof(T<double>), alignof(AlignedCharArrayUnion<double>));
-  EXPECT_EQ(alignof(T<long double>),
-            alignof(AlignedCharArrayUnion<long double>));
-  EXPECT_EQ(alignof(T<void *>), alignof(AlignedCharArrayUnion<void *>));
-  EXPECT_EQ(alignof(T<int *>), alignof(AlignedCharArrayUnion<int *>));
-  EXPECT_EQ(alignof(T<double (*)(double)>),
-            alignof(AlignedCharArrayUnion<double (*)(double)>));
-  EXPECT_EQ(alignof(T<double (S6::*)()>),
-            alignof(AlignedCharArrayUnion<double (S6::*)()>));
-  EXPECT_EQ(alignof(S1), alignof(AlignedCharArrayUnion<S1>));
-  EXPECT_EQ(alignof(S2), alignof(AlignedCharArrayUnion<S2>));
-  EXPECT_EQ(alignof(S3), alignof(AlignedCharArrayUnion<S3>));
-  EXPECT_EQ(alignof(S4), alignof(AlignedCharArrayUnion<S4>));
-  EXPECT_EQ(alignof(S5), alignof(AlignedCharArrayUnion<S5>));
-  EXPECT_EQ(alignof(S6), alignof(AlignedCharArrayUnion<S6>));
-  EXPECT_EQ(alignof(D1), alignof(AlignedCharArrayUnion<D1>));
-  EXPECT_EQ(alignof(D2), alignof(AlignedCharArrayUnion<D2>));
-  EXPECT_EQ(alignof(D3), alignof(AlignedCharArrayUnion<D3>));
-  EXPECT_EQ(alignof(D4), alignof(AlignedCharArrayUnion<D4>));
-  EXPECT_EQ(alignof(D5), alignof(AlignedCharArrayUnion<D5>));
-  EXPECT_EQ(alignof(D6), alignof(AlignedCharArrayUnion<D6>));
-  EXPECT_EQ(alignof(D7), alignof(AlignedCharArrayUnion<D7>));
-  EXPECT_EQ(alignof(D8), alignof(AlignedCharArrayUnion<D8>));
-  EXPECT_EQ(alignof(D9), alignof(AlignedCharArrayUnion<D9>));
-  EXPECT_EQ(alignof(V1), alignof(AlignedCharArrayUnion<V1>));
-  EXPECT_EQ(alignof(V2), alignof(AlignedCharArrayUnion<V2>));
-  EXPECT_EQ(alignof(V3), alignof(AlignedCharArrayUnion<V3>));
-  EXPECT_EQ(alignof(V4), alignof(AlignedCharArrayUnion<V4>));
-  EXPECT_EQ(alignof(V5), alignof(AlignedCharArrayUnion<V5>));
-  EXPECT_EQ(alignof(V6), alignof(AlignedCharArrayUnion<V6>));
-  EXPECT_EQ(alignof(V7), alignof(AlignedCharArrayUnion<V7>));
-
-  // Some versions of MSVC get this wrong somewhat disturbingly. The failure
-  // appears to be benign: alignof(V8) produces a preposterous value: 12
-#ifndef _MSC_VER
-  EXPECT_EQ(alignof(V8), alignof(AlignedCharArrayUnion<V8>));
-#endif
-
-  EXPECT_EQ(sizeof(char), sizeof(AlignedCharArrayUnion<char>));
-  EXPECT_EQ(sizeof(char[1]), sizeof(AlignedCharArrayUnion<char[1]>));
-  EXPECT_EQ(sizeof(char[2]), sizeof(AlignedCharArrayUnion<char[2]>));
-  EXPECT_EQ(sizeof(char[3]), sizeof(AlignedCharArrayUnion<char[3]>));
-  EXPECT_EQ(sizeof(char[4]), sizeof(AlignedCharArrayUnion<char[4]>));
-  EXPECT_EQ(sizeof(char[5]), sizeof(AlignedCharArrayUnion<char[5]>));
-  EXPECT_EQ(sizeof(char[8]), sizeof(AlignedCharArrayUnion<char[8]>));
-  EXPECT_EQ(sizeof(char[13]), sizeof(AlignedCharArrayUnion<char[13]>));
-  EXPECT_EQ(sizeof(char[16]), sizeof(AlignedCharArrayUnion<char[16]>));
-  EXPECT_EQ(sizeof(char[21]), sizeof(AlignedCharArrayUnion<char[21]>));
-  EXPECT_EQ(sizeof(char[32]), sizeof(AlignedCharArrayUnion<char[32]>));
-  EXPECT_EQ(sizeof(short), sizeof(AlignedCharArrayUnion<short>));
-  EXPECT_EQ(sizeof(int), sizeof(AlignedCharArrayUnion<int>));
-  EXPECT_EQ(sizeof(long), sizeof(AlignedCharArrayUnion<long>));
-  EXPECT_EQ(sizeof(long long),
-            sizeof(AlignedCharArrayUnion<long long>));
-  EXPECT_EQ(sizeof(float), sizeof(AlignedCharArrayUnion<float>));
-  EXPECT_EQ(sizeof(double), sizeof(AlignedCharArrayUnion<double>));
-  EXPECT_EQ(sizeof(long double),
-            sizeof(AlignedCharArrayUnion<long double>));
-  EXPECT_EQ(sizeof(void *), sizeof(AlignedCharArrayUnion<void *>));
-  EXPECT_EQ(sizeof(int *), sizeof(AlignedCharArrayUnion<int *>));
-  EXPECT_EQ(sizeof(double (*)(double)),
-            sizeof(AlignedCharArrayUnion<double (*)(double)>));
-  EXPECT_EQ(sizeof(double (S6::*)()),
-            sizeof(AlignedCharArrayUnion<double (S6::*)()>));
-  EXPECT_EQ(sizeof(S1), sizeof(AlignedCharArrayUnion<S1>));
-  EXPECT_EQ(sizeof(S2), sizeof(AlignedCharArrayUnion<S2>));
-  EXPECT_EQ(sizeof(S3), sizeof(AlignedCharArrayUnion<S3>));
-  EXPECT_EQ(sizeof(S4), sizeof(AlignedCharArrayUnion<S4>));
-  EXPECT_EQ(sizeof(S5), sizeof(AlignedCharArrayUnion<S5>));
-  EXPECT_EQ(sizeof(S6), sizeof(AlignedCharArrayUnion<S6>));
-  EXPECT_EQ(sizeof(D1), sizeof(AlignedCharArrayUnion<D1>));
-  EXPECT_EQ(sizeof(D2), sizeof(AlignedCharArrayUnion<D2>));
-  EXPECT_EQ(sizeof(D3), sizeof(AlignedCharArrayUnion<D3>));
-  EXPECT_EQ(sizeof(D4), sizeof(AlignedCharArrayUnion<D4>));
-  EXPECT_EQ(sizeof(D5), sizeof(AlignedCharArrayUnion<D5>));
-  EXPECT_EQ(sizeof(D6), sizeof(AlignedCharArrayUnion<D6>));
-  EXPECT_EQ(sizeof(D7), sizeof(AlignedCharArrayUnion<D7>));
-  EXPECT_EQ(sizeof(D8), sizeof(AlignedCharArrayUnion<D8>));
-  EXPECT_EQ(sizeof(D9), sizeof(AlignedCharArrayUnion<D9>));
-  EXPECT_EQ(sizeof(D9[1]), sizeof(AlignedCharArrayUnion<D9[1]>));
-  EXPECT_EQ(sizeof(D9[2]), sizeof(AlignedCharArrayUnion<D9[2]>));
-  EXPECT_EQ(sizeof(D9[3]), sizeof(AlignedCharArrayUnion<D9[3]>));
-  EXPECT_EQ(sizeof(D9[4]), sizeof(AlignedCharArrayUnion<D9[4]>));
-  EXPECT_EQ(sizeof(D9[5]), sizeof(AlignedCharArrayUnion<D9[5]>));
-  EXPECT_EQ(sizeof(D9[8]), sizeof(AlignedCharArrayUnion<D9[8]>));
-  EXPECT_EQ(sizeof(D9[13]), sizeof(AlignedCharArrayUnion<D9[13]>));
-  EXPECT_EQ(sizeof(D9[16]), sizeof(AlignedCharArrayUnion<D9[16]>));
-  EXPECT_EQ(sizeof(D9[21]), sizeof(AlignedCharArrayUnion<D9[21]>));
-  EXPECT_EQ(sizeof(D9[32]), sizeof(AlignedCharArrayUnion<D9[32]>));
-  EXPECT_EQ(sizeof(V1), sizeof(AlignedCharArrayUnion<V1>));
-  EXPECT_EQ(sizeof(V2), sizeof(AlignedCharArrayUnion<V2>));
-  EXPECT_EQ(sizeof(V3), sizeof(AlignedCharArrayUnion<V3>));
-  EXPECT_EQ(sizeof(V4), sizeof(AlignedCharArrayUnion<V4>));
-  EXPECT_EQ(sizeof(V5), sizeof(AlignedCharArrayUnion<V5>));
-  EXPECT_EQ(sizeof(V6), sizeof(AlignedCharArrayUnion<V6>));
-  EXPECT_EQ(sizeof(V7), sizeof(AlignedCharArrayUnion<V7>));
-
-  // Some versions of MSVC also get this wrong. The failure again appears to be
-  // benign: sizeof(V8) is only 52 bytes, but our array reserves 56.
-#ifndef _MSC_VER
-  EXPECT_EQ(sizeof(V8), sizeof(AlignedCharArrayUnion<V8>));
-#endif
-}
-} // end anonymous namespace