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      1 //=== - llvm/unittest/Support/AlignOfTest.cpp - Alignment utility tests ---===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #ifdef _MSC_VER
     11 // Disable warnings about alignment-based structure padding.
     12 // This must be above the includes to suppress warnings in included templates.
     13 #pragma warning(disable:4324)
     14 #endif
     15 
     16 #include "llvm/Support/AlignOf.h"
     17 #include "llvm/Support/Compiler.h"
     18 #include "gtest/gtest.h"
     19 
     20 using namespace llvm;
     21 
     22 namespace {
     23 // Disable warnings about questionable type definitions.
     24 // We're testing that even questionable types work with the alignment utilities.
     25 #ifdef _MSC_VER
     26 #pragma warning(disable:4584)
     27 #endif
     28 
     29 // Suppress direct base '{anonymous}::S1' inaccessible in '{anonymous}::D9'
     30 // due to ambiguity warning.
     31 #ifdef __clang__
     32 #pragma clang diagnostic ignored "-Wunknown-pragmas"
     33 #pragma clang diagnostic ignored "-Winaccessible-base"
     34 #elif ((__GNUC__ * 100) + __GNUC_MINOR__) >= 402
     35 // Pragma based warning suppression was introduced in GGC 4.2.  Additionally
     36 // this warning is "enabled by default".  The warning still appears if -Wall is
     37 // suppressed.  Apparently GCC suppresses it when -w is specifed, which is odd.
     38 #pragma GCC diagnostic warning "-w"
     39 #endif
     40 
     41 // Define some fixed alignment types to use in these tests.
     42 struct LLVM_ALIGNAS(1) A1 {};
     43 struct LLVM_ALIGNAS(2) A2 {};
     44 struct LLVM_ALIGNAS(4) A4 {};
     45 struct LLVM_ALIGNAS(8) A8 {};
     46 
     47 struct S1 {};
     48 struct S2 { char a; };
     49 struct S3 { int x; };
     50 struct S4 { double y; };
     51 struct S5 { A1 a1; A2 a2; A4 a4; A8 a8; };
     52 struct S6 { double f(); };
     53 struct D1 : S1 {};
     54 struct D2 : S6 { float g(); };
     55 struct D3 : S2 {};
     56 struct D4 : S2 { int x; };
     57 struct D5 : S3 { char c; };
     58 struct D6 : S2, S3 {};
     59 struct D7 : S1, S3 {};
     60 struct D8 : S1, D4, D5 { double x[2]; };
     61 struct D9 : S1, D1 { S1 s1; };
     62 struct V1 { virtual ~V1(); };
     63 struct V2 { int x; virtual ~V2(); };
     64 struct V3 : V1 {
     65   ~V3() override;
     66 };
     67 struct V4 : virtual V2 { int y;
     68   ~V4() override;
     69 };
     70 struct V5 : V4, V3 { double z;
     71   ~V5() override;
     72 };
     73 struct V6 : S1 { virtual ~V6(); };
     74 struct V7 : virtual V2, virtual V6 {
     75   ~V7() override;
     76 };
     77 struct V8 : V5, virtual V6, V7 { double zz;
     78   ~V8() override;
     79 };
     80 
     81 double S6::f() { return 0.0; }
     82 float D2::g() { return 0.0f; }
     83 V1::~V1() {}
     84 V2::~V2() {}
     85 V3::~V3() {}
     86 V4::~V4() {}
     87 V5::~V5() {}
     88 V6::~V6() {}
     89 V7::~V7() {}
     90 V8::~V8() {}
     91 
     92 struct Abstract1 {
     93   virtual ~Abstract1() {}
     94   virtual void method() = 0;
     95 
     96   char c;
     97 };
     98 
     99 struct Abstract2 : Abstract1 {
    100   ~Abstract2() override = default;
    101   double d;
    102 };
    103 
    104 struct Final final : Abstract2 {
    105   void method() override {}
    106 };
    107 
    108 // Ensure alignment is a compile-time constant.
    109 char LLVM_ATTRIBUTE_UNUSED test_arr1
    110   [AlignOf<char>::Alignment > 0]
    111   [AlignOf<short>::Alignment > 0]
    112   [AlignOf<int>::Alignment > 0]
    113   [AlignOf<long>::Alignment > 0]
    114   [AlignOf<long long>::Alignment > 0]
    115   [AlignOf<float>::Alignment > 0]
    116   [AlignOf<double>::Alignment > 0]
    117   [AlignOf<long double>::Alignment > 0]
    118   [AlignOf<void *>::Alignment > 0]
    119   [AlignOf<int *>::Alignment > 0]
    120   [AlignOf<double (*)(double)>::Alignment > 0]
    121   [AlignOf<double (S6::*)()>::Alignment > 0];
    122 char LLVM_ATTRIBUTE_UNUSED test_arr2
    123   [AlignOf<A1>::Alignment > 0]
    124   [AlignOf<A2>::Alignment > 0]
    125   [AlignOf<A4>::Alignment > 0]
    126   [AlignOf<A8>::Alignment > 0];
    127 char LLVM_ATTRIBUTE_UNUSED test_arr3
    128   [AlignOf<S1>::Alignment > 0]
    129   [AlignOf<S2>::Alignment > 0]
    130   [AlignOf<S3>::Alignment > 0]
    131   [AlignOf<S4>::Alignment > 0]
    132   [AlignOf<S5>::Alignment > 0]
    133   [AlignOf<S6>::Alignment > 0];
    134 char LLVM_ATTRIBUTE_UNUSED test_arr4
    135   [AlignOf<D1>::Alignment > 0]
    136   [AlignOf<D2>::Alignment > 0]
    137   [AlignOf<D3>::Alignment > 0]
    138   [AlignOf<D4>::Alignment > 0]
    139   [AlignOf<D5>::Alignment > 0]
    140   [AlignOf<D6>::Alignment > 0]
    141   [AlignOf<D7>::Alignment > 0]
    142   [AlignOf<D8>::Alignment > 0]
    143   [AlignOf<D9>::Alignment > 0];
    144 char LLVM_ATTRIBUTE_UNUSED test_arr5
    145   [AlignOf<V1>::Alignment > 0]
    146   [AlignOf<V2>::Alignment > 0]
    147   [AlignOf<V3>::Alignment > 0]
    148   [AlignOf<V4>::Alignment > 0]
    149   [AlignOf<V5>::Alignment > 0]
    150   [AlignOf<V6>::Alignment > 0]
    151   [AlignOf<V7>::Alignment > 0]
    152   [AlignOf<V8>::Alignment > 0];
    153 
    154 TEST(AlignOfTest, BasicAlignmentInvariants) {
    155   EXPECT_LE(1u, alignOf<A1>());
    156   EXPECT_LE(2u, alignOf<A2>());
    157   EXPECT_LE(4u, alignOf<A4>());
    158   EXPECT_LE(8u, alignOf<A8>());
    159 
    160   EXPECT_EQ(1u, alignOf<char>());
    161   EXPECT_LE(alignOf<char>(),   alignOf<short>());
    162   EXPECT_LE(alignOf<short>(),  alignOf<int>());
    163   EXPECT_LE(alignOf<int>(),    alignOf<long>());
    164   EXPECT_LE(alignOf<long>(),   alignOf<long long>());
    165   EXPECT_LE(alignOf<char>(),   alignOf<float>());
    166   EXPECT_LE(alignOf<float>(),  alignOf<double>());
    167   EXPECT_LE(alignOf<char>(),   alignOf<long double>());
    168   EXPECT_LE(alignOf<char>(),   alignOf<void *>());
    169   EXPECT_EQ(alignOf<void *>(), alignOf<int *>());
    170   EXPECT_LE(alignOf<char>(),   alignOf<S1>());
    171   EXPECT_LE(alignOf<S1>(),     alignOf<S2>());
    172   EXPECT_LE(alignOf<S1>(),     alignOf<S3>());
    173   EXPECT_LE(alignOf<S1>(),     alignOf<S4>());
    174   EXPECT_LE(alignOf<S1>(),     alignOf<S5>());
    175   EXPECT_LE(alignOf<S1>(),     alignOf<S6>());
    176   EXPECT_LE(alignOf<S1>(),     alignOf<D1>());
    177   EXPECT_LE(alignOf<S1>(),     alignOf<D2>());
    178   EXPECT_LE(alignOf<S1>(),     alignOf<D3>());
    179   EXPECT_LE(alignOf<S1>(),     alignOf<D4>());
    180   EXPECT_LE(alignOf<S1>(),     alignOf<D5>());
    181   EXPECT_LE(alignOf<S1>(),     alignOf<D6>());
    182   EXPECT_LE(alignOf<S1>(),     alignOf<D7>());
    183   EXPECT_LE(alignOf<S1>(),     alignOf<D8>());
    184   EXPECT_LE(alignOf<S1>(),     alignOf<D9>());
    185   EXPECT_LE(alignOf<S1>(),     alignOf<V1>());
    186   EXPECT_LE(alignOf<V1>(),     alignOf<V2>());
    187   EXPECT_LE(alignOf<V1>(),     alignOf<V3>());
    188   EXPECT_LE(alignOf<V1>(),     alignOf<V4>());
    189   EXPECT_LE(alignOf<V1>(),     alignOf<V5>());
    190   EXPECT_LE(alignOf<V1>(),     alignOf<V6>());
    191   EXPECT_LE(alignOf<V1>(),     alignOf<V7>());
    192   EXPECT_LE(alignOf<V1>(),     alignOf<V8>());
    193 
    194   EXPECT_LE(alignOf<char>(), alignOf<Abstract1>());
    195   EXPECT_LE(alignOf<double>(), alignOf<Abstract2>());
    196   EXPECT_LE(alignOf<Abstract2>(), alignOf<Final>());
    197 }
    198 
    199 TEST(AlignOfTest, BasicAlignedArray) {
    200   EXPECT_LE(1u, alignOf<AlignedCharArrayUnion<A1> >());
    201   EXPECT_LE(2u, alignOf<AlignedCharArrayUnion<A2> >());
    202   EXPECT_LE(4u, alignOf<AlignedCharArrayUnion<A4> >());
    203   EXPECT_LE(8u, alignOf<AlignedCharArrayUnion<A8> >());
    204 
    205   EXPECT_LE(1u, sizeof(AlignedCharArrayUnion<A1>));
    206   EXPECT_LE(2u, sizeof(AlignedCharArrayUnion<A2>));
    207   EXPECT_LE(4u, sizeof(AlignedCharArrayUnion<A4>));
    208   EXPECT_LE(8u, sizeof(AlignedCharArrayUnion<A8>));
    209 
    210   EXPECT_EQ(1u, (alignOf<AlignedCharArrayUnion<A1> >()));
    211   EXPECT_EQ(2u, (alignOf<AlignedCharArrayUnion<A1, A2> >()));
    212   EXPECT_EQ(4u, (alignOf<AlignedCharArrayUnion<A1, A2, A4> >()));
    213   EXPECT_EQ(8u, (alignOf<AlignedCharArrayUnion<A1, A2, A4, A8> >()));
    214 
    215   EXPECT_EQ(1u, sizeof(AlignedCharArrayUnion<A1>));
    216   EXPECT_EQ(2u, sizeof(AlignedCharArrayUnion<A1, A2>));
    217   EXPECT_EQ(4u, sizeof(AlignedCharArrayUnion<A1, A2, A4>));
    218   EXPECT_EQ(8u, sizeof(AlignedCharArrayUnion<A1, A2, A4, A8>));
    219 
    220   EXPECT_EQ(1u, (alignOf<AlignedCharArrayUnion<A1[1]> >()));
    221   EXPECT_EQ(2u, (alignOf<AlignedCharArrayUnion<A1[2], A2[1]> >()));
    222   EXPECT_EQ(4u, (alignOf<AlignedCharArrayUnion<A1[42], A2[55],
    223                                                A4[13]> >()));
    224   EXPECT_EQ(8u, (alignOf<AlignedCharArrayUnion<A1[2], A2[1],
    225                                                A4, A8> >()));
    226 
    227   EXPECT_EQ(1u,  sizeof(AlignedCharArrayUnion<A1[1]>));
    228   EXPECT_EQ(2u,  sizeof(AlignedCharArrayUnion<A1[2], A2[1]>));
    229   EXPECT_EQ(4u,  sizeof(AlignedCharArrayUnion<A1[3], A2[2], A4>));
    230   EXPECT_EQ(16u, sizeof(AlignedCharArrayUnion<A1, A2[3],
    231                                               A4[3], A8>));
    232 
    233   // For other tests we simply assert that the alignment of the union mathes
    234   // that of the fundamental type and hope that we have any weird type
    235   // productions that would trigger bugs.
    236   EXPECT_EQ(alignOf<char>(), alignOf<AlignedCharArrayUnion<char> >());
    237   EXPECT_EQ(alignOf<short>(), alignOf<AlignedCharArrayUnion<short> >());
    238   EXPECT_EQ(alignOf<int>(), alignOf<AlignedCharArrayUnion<int> >());
    239   EXPECT_EQ(alignOf<long>(), alignOf<AlignedCharArrayUnion<long> >());
    240   EXPECT_EQ(alignOf<long long>(),
    241             alignOf<AlignedCharArrayUnion<long long> >());
    242   EXPECT_EQ(alignOf<float>(), alignOf<AlignedCharArrayUnion<float> >());
    243   EXPECT_EQ(alignOf<double>(), alignOf<AlignedCharArrayUnion<double> >());
    244   EXPECT_EQ(alignOf<long double>(),
    245             alignOf<AlignedCharArrayUnion<long double> >());
    246   EXPECT_EQ(alignOf<void *>(), alignOf<AlignedCharArrayUnion<void *> >());
    247   EXPECT_EQ(alignOf<int *>(), alignOf<AlignedCharArrayUnion<int *> >());
    248   EXPECT_EQ(alignOf<double (*)(double)>(),
    249             alignOf<AlignedCharArrayUnion<double (*)(double)> >());
    250   EXPECT_EQ(alignOf<double (S6::*)()>(),
    251             alignOf<AlignedCharArrayUnion<double (S6::*)()> >());
    252   EXPECT_EQ(alignOf<S1>(), alignOf<AlignedCharArrayUnion<S1> >());
    253   EXPECT_EQ(alignOf<S2>(), alignOf<AlignedCharArrayUnion<S2> >());
    254   EXPECT_EQ(alignOf<S3>(), alignOf<AlignedCharArrayUnion<S3> >());
    255   EXPECT_EQ(alignOf<S4>(), alignOf<AlignedCharArrayUnion<S4> >());
    256   EXPECT_EQ(alignOf<S5>(), alignOf<AlignedCharArrayUnion<S5> >());
    257   EXPECT_EQ(alignOf<S6>(), alignOf<AlignedCharArrayUnion<S6> >());
    258   EXPECT_EQ(alignOf<D1>(), alignOf<AlignedCharArrayUnion<D1> >());
    259   EXPECT_EQ(alignOf<D2>(), alignOf<AlignedCharArrayUnion<D2> >());
    260   EXPECT_EQ(alignOf<D3>(), alignOf<AlignedCharArrayUnion<D3> >());
    261   EXPECT_EQ(alignOf<D4>(), alignOf<AlignedCharArrayUnion<D4> >());
    262   EXPECT_EQ(alignOf<D5>(), alignOf<AlignedCharArrayUnion<D5> >());
    263   EXPECT_EQ(alignOf<D6>(), alignOf<AlignedCharArrayUnion<D6> >());
    264   EXPECT_EQ(alignOf<D7>(), alignOf<AlignedCharArrayUnion<D7> >());
    265   EXPECT_EQ(alignOf<D8>(), alignOf<AlignedCharArrayUnion<D8> >());
    266   EXPECT_EQ(alignOf<D9>(), alignOf<AlignedCharArrayUnion<D9> >());
    267   EXPECT_EQ(alignOf<V1>(), alignOf<AlignedCharArrayUnion<V1> >());
    268   EXPECT_EQ(alignOf<V2>(), alignOf<AlignedCharArrayUnion<V2> >());
    269   EXPECT_EQ(alignOf<V3>(), alignOf<AlignedCharArrayUnion<V3> >());
    270   EXPECT_EQ(alignOf<V4>(), alignOf<AlignedCharArrayUnion<V4> >());
    271   EXPECT_EQ(alignOf<V5>(), alignOf<AlignedCharArrayUnion<V5> >());
    272   EXPECT_EQ(alignOf<V6>(), alignOf<AlignedCharArrayUnion<V6> >());
    273   EXPECT_EQ(alignOf<V7>(), alignOf<AlignedCharArrayUnion<V7> >());
    274 
    275   // Some versions of MSVC get this wrong somewhat disturbingly. The failure
    276   // appears to be benign: alignOf<V8>() produces a preposterous value: 12
    277 #ifndef _MSC_VER
    278   EXPECT_EQ(alignOf<V8>(), alignOf<AlignedCharArrayUnion<V8> >());
    279 #endif
    280 
    281   EXPECT_EQ(sizeof(char), sizeof(AlignedCharArrayUnion<char>));
    282   EXPECT_EQ(sizeof(char[1]), sizeof(AlignedCharArrayUnion<char[1]>));
    283   EXPECT_EQ(sizeof(char[2]), sizeof(AlignedCharArrayUnion<char[2]>));
    284   EXPECT_EQ(sizeof(char[3]), sizeof(AlignedCharArrayUnion<char[3]>));
    285   EXPECT_EQ(sizeof(char[4]), sizeof(AlignedCharArrayUnion<char[4]>));
    286   EXPECT_EQ(sizeof(char[5]), sizeof(AlignedCharArrayUnion<char[5]>));
    287   EXPECT_EQ(sizeof(char[8]), sizeof(AlignedCharArrayUnion<char[8]>));
    288   EXPECT_EQ(sizeof(char[13]), sizeof(AlignedCharArrayUnion<char[13]>));
    289   EXPECT_EQ(sizeof(char[16]), sizeof(AlignedCharArrayUnion<char[16]>));
    290   EXPECT_EQ(sizeof(char[21]), sizeof(AlignedCharArrayUnion<char[21]>));
    291   EXPECT_EQ(sizeof(char[32]), sizeof(AlignedCharArrayUnion<char[32]>));
    292   EXPECT_EQ(sizeof(short), sizeof(AlignedCharArrayUnion<short>));
    293   EXPECT_EQ(sizeof(int), sizeof(AlignedCharArrayUnion<int>));
    294   EXPECT_EQ(sizeof(long), sizeof(AlignedCharArrayUnion<long>));
    295   EXPECT_EQ(sizeof(long long),
    296             sizeof(AlignedCharArrayUnion<long long>));
    297   EXPECT_EQ(sizeof(float), sizeof(AlignedCharArrayUnion<float>));
    298   EXPECT_EQ(sizeof(double), sizeof(AlignedCharArrayUnion<double>));
    299   EXPECT_EQ(sizeof(long double),
    300             sizeof(AlignedCharArrayUnion<long double>));
    301   EXPECT_EQ(sizeof(void *), sizeof(AlignedCharArrayUnion<void *>));
    302   EXPECT_EQ(sizeof(int *), sizeof(AlignedCharArrayUnion<int *>));
    303   EXPECT_EQ(sizeof(double (*)(double)),
    304             sizeof(AlignedCharArrayUnion<double (*)(double)>));
    305   EXPECT_EQ(sizeof(double (S6::*)()),
    306             sizeof(AlignedCharArrayUnion<double (S6::*)()>));
    307   EXPECT_EQ(sizeof(S1), sizeof(AlignedCharArrayUnion<S1>));
    308   EXPECT_EQ(sizeof(S2), sizeof(AlignedCharArrayUnion<S2>));
    309   EXPECT_EQ(sizeof(S3), sizeof(AlignedCharArrayUnion<S3>));
    310   EXPECT_EQ(sizeof(S4), sizeof(AlignedCharArrayUnion<S4>));
    311   EXPECT_EQ(sizeof(S5), sizeof(AlignedCharArrayUnion<S5>));
    312   EXPECT_EQ(sizeof(S6), sizeof(AlignedCharArrayUnion<S6>));
    313   EXPECT_EQ(sizeof(D1), sizeof(AlignedCharArrayUnion<D1>));
    314   EXPECT_EQ(sizeof(D2), sizeof(AlignedCharArrayUnion<D2>));
    315   EXPECT_EQ(sizeof(D3), sizeof(AlignedCharArrayUnion<D3>));
    316   EXPECT_EQ(sizeof(D4), sizeof(AlignedCharArrayUnion<D4>));
    317   EXPECT_EQ(sizeof(D5), sizeof(AlignedCharArrayUnion<D5>));
    318   EXPECT_EQ(sizeof(D6), sizeof(AlignedCharArrayUnion<D6>));
    319   EXPECT_EQ(sizeof(D7), sizeof(AlignedCharArrayUnion<D7>));
    320   EXPECT_EQ(sizeof(D8), sizeof(AlignedCharArrayUnion<D8>));
    321   EXPECT_EQ(sizeof(D9), sizeof(AlignedCharArrayUnion<D9>));
    322   EXPECT_EQ(sizeof(D9[1]), sizeof(AlignedCharArrayUnion<D9[1]>));
    323   EXPECT_EQ(sizeof(D9[2]), sizeof(AlignedCharArrayUnion<D9[2]>));
    324   EXPECT_EQ(sizeof(D9[3]), sizeof(AlignedCharArrayUnion<D9[3]>));
    325   EXPECT_EQ(sizeof(D9[4]), sizeof(AlignedCharArrayUnion<D9[4]>));
    326   EXPECT_EQ(sizeof(D9[5]), sizeof(AlignedCharArrayUnion<D9[5]>));
    327   EXPECT_EQ(sizeof(D9[8]), sizeof(AlignedCharArrayUnion<D9[8]>));
    328   EXPECT_EQ(sizeof(D9[13]), sizeof(AlignedCharArrayUnion<D9[13]>));
    329   EXPECT_EQ(sizeof(D9[16]), sizeof(AlignedCharArrayUnion<D9[16]>));
    330   EXPECT_EQ(sizeof(D9[21]), sizeof(AlignedCharArrayUnion<D9[21]>));
    331   EXPECT_EQ(sizeof(D9[32]), sizeof(AlignedCharArrayUnion<D9[32]>));
    332   EXPECT_EQ(sizeof(V1), sizeof(AlignedCharArrayUnion<V1>));
    333   EXPECT_EQ(sizeof(V2), sizeof(AlignedCharArrayUnion<V2>));
    334   EXPECT_EQ(sizeof(V3), sizeof(AlignedCharArrayUnion<V3>));
    335   EXPECT_EQ(sizeof(V4), sizeof(AlignedCharArrayUnion<V4>));
    336   EXPECT_EQ(sizeof(V5), sizeof(AlignedCharArrayUnion<V5>));
    337   EXPECT_EQ(sizeof(V6), sizeof(AlignedCharArrayUnion<V6>));
    338   EXPECT_EQ(sizeof(V7), sizeof(AlignedCharArrayUnion<V7>));
    339 
    340   // Some versions of MSVC also get this wrong. The failure again appears to be
    341   // benign: sizeof(V8) is only 52 bytes, but our array reserves 56.
    342 #ifndef _MSC_VER
    343   EXPECT_EQ(sizeof(V8), sizeof(AlignedCharArrayUnion<V8>));
    344 #endif
    345 
    346   EXPECT_EQ(1u, (alignOf<AlignedCharArray<1, 1> >()));
    347   EXPECT_EQ(2u, (alignOf<AlignedCharArray<2, 1> >()));
    348   EXPECT_EQ(4u, (alignOf<AlignedCharArray<4, 1> >()));
    349   EXPECT_EQ(8u, (alignOf<AlignedCharArray<8, 1> >()));
    350   EXPECT_EQ(16u, (alignOf<AlignedCharArray<16, 1> >()));
    351 
    352   EXPECT_EQ(1u, sizeof(AlignedCharArray<1, 1>));
    353   EXPECT_EQ(7u, sizeof(AlignedCharArray<1, 7>));
    354   EXPECT_EQ(2u, sizeof(AlignedCharArray<2, 2>));
    355   EXPECT_EQ(16u, sizeof(AlignedCharArray<2, 16>));
    356 }
    357 } // end anonymous namespace
    358