unittests/Support/AlignOfTest.cpp

   1 //=== - llvm/unittest/Support/AlignOfTest.cpp - Alignment utility tests ---===//
   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 #ifdef _MSC_VER
  10 // Disable warnings about alignment-based structure padding.
  11 // This must be above the includes to suppress warnings in included templates.
  12 #pragma warning(disable:4324)
  13 #endif
  14
  15 #include "llvm/Support/AlignOf.h"
  16 #include "llvm/Support/Compiler.h"
  17 #include "gtest/gtest.h"
  18
  19 using namespace llvm;
  20
  21 namespace {
  22 // Disable warnings about questionable type definitions.
  23 // We're testing that even questionable types work with the alignment utilities.
  24 #ifdef _MSC_VER
  25 #pragma warning(disable:4584)
  26 #endif
  27
  28 // Suppress direct base '{anonymous}::S1' inaccessible in '{anonymous}::D9'
  29 // due to ambiguity warning.
  30 #ifdef __clang__
  31 #pragma clang diagnostic ignored "-Wunknown-pragmas"
  32 #pragma clang diagnostic ignored "-Winaccessible-base"
  33 #elif ((__GNUC__ * 100) + __GNUC_MINOR__) >= 402
  34 // Pragma based warning suppression was introduced in GGC 4.2.  Additionally
  35 // this warning is "enabled by default".  The warning still appears if -Wall is
  36 // suppressed.  Apparently GCC suppresses it when -w is specifed, which is odd.
  37 #pragma GCC diagnostic warning "-w"
  38 #endif
  39
  40 // Define some fixed alignment types to use in these tests.
  41 struct alignas(1) A1 {};
  42 struct alignas(2) A2 {};
  43 struct alignas(4) A4 {};
  44 struct alignas(8) A8 {};
  45
  46 struct S1 {};
  47 struct S2 { char a; };
  48 struct S3 { int x; };
  49 struct S4 { double y; };
  50 struct S5 { A1 a1; A2 a2; A4 a4; A8 a8; };
  51 struct S6 { double f(); };
  52 struct D1 : S1 {};
  53 struct D2 : S6 { float g(); };
  54 struct D3 : S2 {};
  55 struct D4 : S2 { int x; };
  56 struct D5 : S3 { char c; };
  57 struct D6 : S2, S3 {};
  58 struct D7 : S1, S3 {};
  59 struct D8 : S1, D4, D5 { double x[2]; };
  60 struct D9 : S1, D1 { S1 s1; };
  61 struct V1 { virtual ~V1(); };
  62 struct V2 { int x; virtual ~V2(); };
  63 struct V3 : V1 {
  64   ~V3() override;
  65 };
  66 struct V4 : virtual V2 { int y;
  67   ~V4() override;
  68 };
  69 struct V5 : V4, V3 { double z;
  70   ~V5() override;
  71 };
  72 struct V6 : S1 { virtual ~V6(); };
  73 struct V7 : virtual V2, virtual V6 {
  74   ~V7() override;
  75 };
  76 struct V8 : V5, virtual V6, V7 { double zz;
  77   ~V8() override;
  78 };
  79
  80 double S6::f() { return 0.0; }
  81 float D2::g() { return 0.0f; }
  82 V1::~V1() {}
  83 V2::~V2() {}
  84 V3::~V3() {}
  85 V4::~V4() {}
  86 V5::~V5() {}
  87 V6::~V6() {}
  88 V7::~V7() {}
  89 V8::~V8() {}
  90
  91 template <typename M> struct T { M m; };
  92
  93 TEST(AlignOfTest, BasicAlignedArray) {
  94   EXPECT_LE(1u, alignof(AlignedCharArrayUnion<A1>));
  95   EXPECT_LE(2u, alignof(AlignedCharArrayUnion<A2>));
  96   EXPECT_LE(4u, alignof(AlignedCharArrayUnion<A4>));
  97   EXPECT_LE(8u, alignof(AlignedCharArrayUnion<A8>));
  98
  99   EXPECT_LE(1u, sizeof(AlignedCharArrayUnion<A1>));
 100   EXPECT_LE(2u, sizeof(AlignedCharArrayUnion<A2>));
 101   EXPECT_LE(4u, sizeof(AlignedCharArrayUnion<A4>));
 102   EXPECT_LE(8u, sizeof(AlignedCharArrayUnion<A8>));
 103
 104   EXPECT_EQ(1u, (alignof(AlignedCharArrayUnion<A1>)));
 105   EXPECT_EQ(2u, (alignof(AlignedCharArrayUnion<A1, A2>)));
 106   EXPECT_EQ(4u, (alignof(AlignedCharArrayUnion<A1, A2, A4>)));
 107   EXPECT_EQ(8u, (alignof(AlignedCharArrayUnion<A1, A2, A4, A8>)));
 108
 109   EXPECT_EQ(1u, sizeof(AlignedCharArrayUnion<A1>));
 110   EXPECT_EQ(2u, sizeof(AlignedCharArrayUnion<A1, A2>));
 111   EXPECT_EQ(4u, sizeof(AlignedCharArrayUnion<A1, A2, A4>));
 112   EXPECT_EQ(8u, sizeof(AlignedCharArrayUnion<A1, A2, A4, A8>));
 113
 114   EXPECT_EQ(1u, (alignof(AlignedCharArrayUnion<A1[1]>)));
 115   EXPECT_EQ(2u, (alignof(AlignedCharArrayUnion<A1[2], A2[1]>)));
 116   EXPECT_EQ(4u, (alignof(AlignedCharArrayUnion<A1[42], A2[55], A4[13]>)));
 117   EXPECT_EQ(8u, (alignof(AlignedCharArrayUnion<A1[2], A2[1], A4, A8>)));
 118
 119   EXPECT_EQ(1u,  sizeof(AlignedCharArrayUnion<A1[1]>));
 120   EXPECT_EQ(2u,  sizeof(AlignedCharArrayUnion<A1[2], A2[1]>));
 121   EXPECT_EQ(4u,  sizeof(AlignedCharArrayUnion<A1[3], A2[2], A4>));
 122   EXPECT_EQ(16u, sizeof(AlignedCharArrayUnion<A1, A2[3],
 123                                               A4[3], A8>));
 124
 125   // For other tests we simply assert that the alignment of the union mathes
 126   // that of the fundamental type and hope that we have any weird type
 127   // productions that would trigger bugs.
 128   EXPECT_EQ(alignof(T<char>), alignof(AlignedCharArrayUnion<char>));
 129   EXPECT_EQ(alignof(T<short>), alignof(AlignedCharArrayUnion<short>));
 130   EXPECT_EQ(alignof(T<int>), alignof(AlignedCharArrayUnion<int>));
 131   EXPECT_EQ(alignof(T<long>), alignof(AlignedCharArrayUnion<long>));
 132   EXPECT_EQ(alignof(T<long long>), alignof(AlignedCharArrayUnion<long long>));
 133   EXPECT_EQ(alignof(T<float>), alignof(AlignedCharArrayUnion<float>));
 134   EXPECT_EQ(alignof(T<double>), alignof(AlignedCharArrayUnion<double>));
 135   EXPECT_EQ(alignof(T<long double>),
 136             alignof(AlignedCharArrayUnion<long double>));
 137   EXPECT_EQ(alignof(T<void *>), alignof(AlignedCharArrayUnion<void *>));
 138   EXPECT_EQ(alignof(T<int *>), alignof(AlignedCharArrayUnion<int *>));
 139   EXPECT_EQ(alignof(T<double (*)(double)>),
 140             alignof(AlignedCharArrayUnion<double (*)(double)>));
 141   EXPECT_EQ(alignof(T<double (S6::*)()>),
 142             alignof(AlignedCharArrayUnion<double (S6::*)()>));
 143   EXPECT_EQ(alignof(S1), alignof(AlignedCharArrayUnion<S1>));
 144   EXPECT_EQ(alignof(S2), alignof(AlignedCharArrayUnion<S2>));
 145   EXPECT_EQ(alignof(S3), alignof(AlignedCharArrayUnion<S3>));
 146   EXPECT_EQ(alignof(S4), alignof(AlignedCharArrayUnion<S4>));
 147   EXPECT_EQ(alignof(S5), alignof(AlignedCharArrayUnion<S5>));
 148   EXPECT_EQ(alignof(S6), alignof(AlignedCharArrayUnion<S6>));
 149   EXPECT_EQ(alignof(D1), alignof(AlignedCharArrayUnion<D1>));
 150   EXPECT_EQ(alignof(D2), alignof(AlignedCharArrayUnion<D2>));
 151   EXPECT_EQ(alignof(D3), alignof(AlignedCharArrayUnion<D3>));
 152   EXPECT_EQ(alignof(D4), alignof(AlignedCharArrayUnion<D4>));
 153   EXPECT_EQ(alignof(D5), alignof(AlignedCharArrayUnion<D5>));
 154   EXPECT_EQ(alignof(D6), alignof(AlignedCharArrayUnion<D6>));
 155   EXPECT_EQ(alignof(D7), alignof(AlignedCharArrayUnion<D7>));
 156   EXPECT_EQ(alignof(D8), alignof(AlignedCharArrayUnion<D8>));
 157   EXPECT_EQ(alignof(D9), alignof(AlignedCharArrayUnion<D9>));
 158   EXPECT_EQ(alignof(V1), alignof(AlignedCharArrayUnion<V1>));
 159   EXPECT_EQ(alignof(V2), alignof(AlignedCharArrayUnion<V2>));
 160   EXPECT_EQ(alignof(V3), alignof(AlignedCharArrayUnion<V3>));
 161   EXPECT_EQ(alignof(V4), alignof(AlignedCharArrayUnion<V4>));
 162   EXPECT_EQ(alignof(V5), alignof(AlignedCharArrayUnion<V5>));
 163   EXPECT_EQ(alignof(V6), alignof(AlignedCharArrayUnion<V6>));
 164   EXPECT_EQ(alignof(V7), alignof(AlignedCharArrayUnion<V7>));
 165
 166   // Some versions of MSVC get this wrong somewhat disturbingly. The failure
 167   // appears to be benign: alignof(V8) produces a preposterous value: 12
 168 #ifndef _MSC_VER
 169   EXPECT_EQ(alignof(V8), alignof(AlignedCharArrayUnion<V8>));
 170 #endif
 171
 172   EXPECT_EQ(sizeof(char), sizeof(AlignedCharArrayUnion<char>));
 173   EXPECT_EQ(sizeof(char[1]), sizeof(AlignedCharArrayUnion<char[1]>));
 174   EXPECT_EQ(sizeof(char[2]), sizeof(AlignedCharArrayUnion<char[2]>));
 175   EXPECT_EQ(sizeof(char[3]), sizeof(AlignedCharArrayUnion<char[3]>));
 176   EXPECT_EQ(sizeof(char[4]), sizeof(AlignedCharArrayUnion<char[4]>));
 177   EXPECT_EQ(sizeof(char[5]), sizeof(AlignedCharArrayUnion<char[5]>));
 178   EXPECT_EQ(sizeof(char[8]), sizeof(AlignedCharArrayUnion<char[8]>));
 179   EXPECT_EQ(sizeof(char[13]), sizeof(AlignedCharArrayUnion<char[13]>));
 180   EXPECT_EQ(sizeof(char[16]), sizeof(AlignedCharArrayUnion<char[16]>));
 181   EXPECT_EQ(sizeof(char[21]), sizeof(AlignedCharArrayUnion<char[21]>));
 182   EXPECT_EQ(sizeof(char[32]), sizeof(AlignedCharArrayUnion<char[32]>));
 183   EXPECT_EQ(sizeof(short), sizeof(AlignedCharArrayUnion<short>));
 184   EXPECT_EQ(sizeof(int), sizeof(AlignedCharArrayUnion<int>));
 185   EXPECT_EQ(sizeof(long), sizeof(AlignedCharArrayUnion<long>));
 186   EXPECT_EQ(sizeof(long long),
 187             sizeof(AlignedCharArrayUnion<long long>));
 188   EXPECT_EQ(sizeof(float), sizeof(AlignedCharArrayUnion<float>));
 189   EXPECT_EQ(sizeof(double), sizeof(AlignedCharArrayUnion<double>));
 190   EXPECT_EQ(sizeof(long double),
 191             sizeof(AlignedCharArrayUnion<long double>));
 192   EXPECT_EQ(sizeof(void *), sizeof(AlignedCharArrayUnion<void *>));
 193   EXPECT_EQ(sizeof(int *), sizeof(AlignedCharArrayUnion<int *>));
 194   EXPECT_EQ(sizeof(double (*)(double)),
 195             sizeof(AlignedCharArrayUnion<double (*)(double)>));
 196   EXPECT_EQ(sizeof(double (S6::*)()),
 197             sizeof(AlignedCharArrayUnion<double (S6::*)()>));
 198   EXPECT_EQ(sizeof(S1), sizeof(AlignedCharArrayUnion<S1>));
 199   EXPECT_EQ(sizeof(S2), sizeof(AlignedCharArrayUnion<S2>));
 200   EXPECT_EQ(sizeof(S3), sizeof(AlignedCharArrayUnion<S3>));
 201   EXPECT_EQ(sizeof(S4), sizeof(AlignedCharArrayUnion<S4>));
 202   EXPECT_EQ(sizeof(S5), sizeof(AlignedCharArrayUnion<S5>));
 203   EXPECT_EQ(sizeof(S6), sizeof(AlignedCharArrayUnion<S6>));
 204   EXPECT_EQ(sizeof(D1), sizeof(AlignedCharArrayUnion<D1>));
 205   EXPECT_EQ(sizeof(D2), sizeof(AlignedCharArrayUnion<D2>));
 206   EXPECT_EQ(sizeof(D3), sizeof(AlignedCharArrayUnion<D3>));
 207   EXPECT_EQ(sizeof(D4), sizeof(AlignedCharArrayUnion<D4>));
 208   EXPECT_EQ(sizeof(D5), sizeof(AlignedCharArrayUnion<D5>));
 209   EXPECT_EQ(sizeof(D6), sizeof(AlignedCharArrayUnion<D6>));
 210   EXPECT_EQ(sizeof(D7), sizeof(AlignedCharArrayUnion<D7>));
 211   EXPECT_EQ(sizeof(D8), sizeof(AlignedCharArrayUnion<D8>));
 212   EXPECT_EQ(sizeof(D9), sizeof(AlignedCharArrayUnion<D9>));
 213   EXPECT_EQ(sizeof(D9[1]), sizeof(AlignedCharArrayUnion<D9[1]>));
 214   EXPECT_EQ(sizeof(D9[2]), sizeof(AlignedCharArrayUnion<D9[2]>));
 215   EXPECT_EQ(sizeof(D9[3]), sizeof(AlignedCharArrayUnion<D9[3]>));
 216   EXPECT_EQ(sizeof(D9[4]), sizeof(AlignedCharArrayUnion<D9[4]>));
 217   EXPECT_EQ(sizeof(D9[5]), sizeof(AlignedCharArrayUnion<D9[5]>));
 218   EXPECT_EQ(sizeof(D9[8]), sizeof(AlignedCharArrayUnion<D9[8]>));
 219   EXPECT_EQ(sizeof(D9[13]), sizeof(AlignedCharArrayUnion<D9[13]>));
 220   EXPECT_EQ(sizeof(D9[16]), sizeof(AlignedCharArrayUnion<D9[16]>));
 221   EXPECT_EQ(sizeof(D9[21]), sizeof(AlignedCharArrayUnion<D9[21]>));
 222   EXPECT_EQ(sizeof(D9[32]), sizeof(AlignedCharArrayUnion<D9[32]>));
 223   EXPECT_EQ(sizeof(V1), sizeof(AlignedCharArrayUnion<V1>));
 224   EXPECT_EQ(sizeof(V2), sizeof(AlignedCharArrayUnion<V2>));
 225   EXPECT_EQ(sizeof(V3), sizeof(AlignedCharArrayUnion<V3>));
 226   EXPECT_EQ(sizeof(V4), sizeof(AlignedCharArrayUnion<V4>));
 227   EXPECT_EQ(sizeof(V5), sizeof(AlignedCharArrayUnion<V5>));
 228   EXPECT_EQ(sizeof(V6), sizeof(AlignedCharArrayUnion<V6>));
 229   EXPECT_EQ(sizeof(V7), sizeof(AlignedCharArrayUnion<V7>));
 230
 231   // Some versions of MSVC also get this wrong. The failure again appears to be
 232   // benign: sizeof(V8) is only 52 bytes, but our array reserves 56.
 233 #ifndef _MSC_VER
 234   EXPECT_EQ(sizeof(V8), sizeof(AlignedCharArrayUnion<V8>));
 235 #endif
 236 }
 237 } // end anonymous namespace