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 
f()80 double S6::f() { return 0.0; }
g()81 float D2::g() { return 0.0f; }
~V1()82 V1::~V1() {}
~V2()83 V2::~V2() {}
~V3()84 V3::~V3() {}
~V4()85 V4::~V4() {}
~V5()86 V5::~V5() {}
~V6()87 V6::~V6() {}
~V7()88 V7::~V7() {}
~V8()89 V8::~V8() {}
90 
91 template <typename M> struct T { M m; };
92 
TEST(AlignOfTest,BasicAlignedArray)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 #ifdef _AIX
135   EXPECT_LE(alignof(T<double>), alignof(AlignedCharArrayUnion<double>));
136   EXPECT_LE(alignof(T<long double>),
137             alignof(AlignedCharArrayUnion<long double>));
138   EXPECT_LE(alignof(S4), alignof(AlignedCharArrayUnion<S4>));
139 #else
140   EXPECT_EQ(alignof(T<double>), alignof(AlignedCharArrayUnion<double>));
141   EXPECT_EQ(alignof(T<long double>),
142             alignof(AlignedCharArrayUnion<long double>));
143   EXPECT_EQ(alignof(S4), alignof(AlignedCharArrayUnion<S4>));
144 #endif
145   EXPECT_EQ(alignof(T<void *>), alignof(AlignedCharArrayUnion<void *>));
146   EXPECT_EQ(alignof(T<int *>), alignof(AlignedCharArrayUnion<int *>));
147   EXPECT_EQ(alignof(T<double (*)(double)>),
148             alignof(AlignedCharArrayUnion<double (*)(double)>));
149   EXPECT_EQ(alignof(T<double (S6::*)()>),
150             alignof(AlignedCharArrayUnion<double (S6::*)()>));
151   EXPECT_EQ(alignof(S1), alignof(AlignedCharArrayUnion<S1>));
152   EXPECT_EQ(alignof(S2), alignof(AlignedCharArrayUnion<S2>));
153   EXPECT_EQ(alignof(S3), alignof(AlignedCharArrayUnion<S3>));
154   EXPECT_EQ(alignof(S5), alignof(AlignedCharArrayUnion<S5>));
155   EXPECT_EQ(alignof(S6), alignof(AlignedCharArrayUnion<S6>));
156   EXPECT_EQ(alignof(D1), alignof(AlignedCharArrayUnion<D1>));
157   EXPECT_EQ(alignof(D2), alignof(AlignedCharArrayUnion<D2>));
158   EXPECT_EQ(alignof(D3), alignof(AlignedCharArrayUnion<D3>));
159   EXPECT_EQ(alignof(D4), alignof(AlignedCharArrayUnion<D4>));
160   EXPECT_EQ(alignof(D5), alignof(AlignedCharArrayUnion<D5>));
161   EXPECT_EQ(alignof(D6), alignof(AlignedCharArrayUnion<D6>));
162   EXPECT_EQ(alignof(D7), alignof(AlignedCharArrayUnion<D7>));
163   EXPECT_EQ(alignof(D8), alignof(AlignedCharArrayUnion<D8>));
164   EXPECT_EQ(alignof(D9), alignof(AlignedCharArrayUnion<D9>));
165   EXPECT_EQ(alignof(V1), alignof(AlignedCharArrayUnion<V1>));
166   EXPECT_EQ(alignof(V2), alignof(AlignedCharArrayUnion<V2>));
167   EXPECT_EQ(alignof(V3), alignof(AlignedCharArrayUnion<V3>));
168   EXPECT_EQ(alignof(V4), alignof(AlignedCharArrayUnion<V4>));
169   EXPECT_EQ(alignof(V5), alignof(AlignedCharArrayUnion<V5>));
170   EXPECT_EQ(alignof(V6), alignof(AlignedCharArrayUnion<V6>));
171   EXPECT_EQ(alignof(V7), alignof(AlignedCharArrayUnion<V7>));
172 
173   // Some versions of MSVC get this wrong somewhat disturbingly. The failure
174   // appears to be benign: alignof(V8) produces a preposterous value: 12
175 #ifndef _MSC_VER
176   EXPECT_EQ(alignof(V8), alignof(AlignedCharArrayUnion<V8>));
177 #endif
178 
179   EXPECT_EQ(sizeof(char), sizeof(AlignedCharArrayUnion<char>));
180   EXPECT_EQ(sizeof(char[1]), sizeof(AlignedCharArrayUnion<char[1]>));
181   EXPECT_EQ(sizeof(char[2]), sizeof(AlignedCharArrayUnion<char[2]>));
182   EXPECT_EQ(sizeof(char[3]), sizeof(AlignedCharArrayUnion<char[3]>));
183   EXPECT_EQ(sizeof(char[4]), sizeof(AlignedCharArrayUnion<char[4]>));
184   EXPECT_EQ(sizeof(char[5]), sizeof(AlignedCharArrayUnion<char[5]>));
185   EXPECT_EQ(sizeof(char[8]), sizeof(AlignedCharArrayUnion<char[8]>));
186   EXPECT_EQ(sizeof(char[13]), sizeof(AlignedCharArrayUnion<char[13]>));
187   EXPECT_EQ(sizeof(char[16]), sizeof(AlignedCharArrayUnion<char[16]>));
188   EXPECT_EQ(sizeof(char[21]), sizeof(AlignedCharArrayUnion<char[21]>));
189   EXPECT_EQ(sizeof(char[32]), sizeof(AlignedCharArrayUnion<char[32]>));
190   EXPECT_EQ(sizeof(short), sizeof(AlignedCharArrayUnion<short>));
191   EXPECT_EQ(sizeof(int), sizeof(AlignedCharArrayUnion<int>));
192   EXPECT_EQ(sizeof(long), sizeof(AlignedCharArrayUnion<long>));
193   EXPECT_EQ(sizeof(long long),
194             sizeof(AlignedCharArrayUnion<long long>));
195   EXPECT_EQ(sizeof(float), sizeof(AlignedCharArrayUnion<float>));
196   EXPECT_EQ(sizeof(double), sizeof(AlignedCharArrayUnion<double>));
197   EXPECT_EQ(sizeof(long double),
198             sizeof(AlignedCharArrayUnion<long double>));
199   EXPECT_EQ(sizeof(void *), sizeof(AlignedCharArrayUnion<void *>));
200   EXPECT_EQ(sizeof(int *), sizeof(AlignedCharArrayUnion<int *>));
201   EXPECT_EQ(sizeof(double (*)(double)),
202             sizeof(AlignedCharArrayUnion<double (*)(double)>));
203   EXPECT_EQ(sizeof(double (S6::*)()),
204             sizeof(AlignedCharArrayUnion<double (S6::*)()>));
205   EXPECT_EQ(sizeof(S1), sizeof(AlignedCharArrayUnion<S1>));
206   EXPECT_EQ(sizeof(S2), sizeof(AlignedCharArrayUnion<S2>));
207   EXPECT_EQ(sizeof(S3), sizeof(AlignedCharArrayUnion<S3>));
208   EXPECT_EQ(sizeof(S4), sizeof(AlignedCharArrayUnion<S4>));
209   EXPECT_EQ(sizeof(S5), sizeof(AlignedCharArrayUnion<S5>));
210   EXPECT_EQ(sizeof(S6), sizeof(AlignedCharArrayUnion<S6>));
211   EXPECT_EQ(sizeof(D1), sizeof(AlignedCharArrayUnion<D1>));
212   EXPECT_EQ(sizeof(D2), sizeof(AlignedCharArrayUnion<D2>));
213   EXPECT_EQ(sizeof(D3), sizeof(AlignedCharArrayUnion<D3>));
214   EXPECT_EQ(sizeof(D4), sizeof(AlignedCharArrayUnion<D4>));
215   EXPECT_EQ(sizeof(D5), sizeof(AlignedCharArrayUnion<D5>));
216   EXPECT_EQ(sizeof(D6), sizeof(AlignedCharArrayUnion<D6>));
217   EXPECT_EQ(sizeof(D7), sizeof(AlignedCharArrayUnion<D7>));
218   EXPECT_EQ(sizeof(D8), sizeof(AlignedCharArrayUnion<D8>));
219   EXPECT_EQ(sizeof(D9), sizeof(AlignedCharArrayUnion<D9>));
220   EXPECT_EQ(sizeof(D9[1]), sizeof(AlignedCharArrayUnion<D9[1]>));
221   EXPECT_EQ(sizeof(D9[2]), sizeof(AlignedCharArrayUnion<D9[2]>));
222   EXPECT_EQ(sizeof(D9[3]), sizeof(AlignedCharArrayUnion<D9[3]>));
223   EXPECT_EQ(sizeof(D9[4]), sizeof(AlignedCharArrayUnion<D9[4]>));
224   EXPECT_EQ(sizeof(D9[5]), sizeof(AlignedCharArrayUnion<D9[5]>));
225   EXPECT_EQ(sizeof(D9[8]), sizeof(AlignedCharArrayUnion<D9[8]>));
226   EXPECT_EQ(sizeof(D9[13]), sizeof(AlignedCharArrayUnion<D9[13]>));
227   EXPECT_EQ(sizeof(D9[16]), sizeof(AlignedCharArrayUnion<D9[16]>));
228   EXPECT_EQ(sizeof(D9[21]), sizeof(AlignedCharArrayUnion<D9[21]>));
229   EXPECT_EQ(sizeof(D9[32]), sizeof(AlignedCharArrayUnion<D9[32]>));
230   EXPECT_EQ(sizeof(V1), sizeof(AlignedCharArrayUnion<V1>));
231   EXPECT_EQ(sizeof(V2), sizeof(AlignedCharArrayUnion<V2>));
232   EXPECT_EQ(sizeof(V3), sizeof(AlignedCharArrayUnion<V3>));
233   EXPECT_EQ(sizeof(V4), sizeof(AlignedCharArrayUnion<V4>));
234   EXPECT_EQ(sizeof(V5), sizeof(AlignedCharArrayUnion<V5>));
235   EXPECT_EQ(sizeof(V6), sizeof(AlignedCharArrayUnion<V6>));
236   EXPECT_EQ(sizeof(V7), sizeof(AlignedCharArrayUnion<V7>));
237 
238   // Some versions of MSVC also get this wrong. The failure again appears to be
239   // benign: sizeof(V8) is only 52 bytes, but our array reserves 56.
240 #ifndef _MSC_VER
241   EXPECT_EQ(sizeof(V8), sizeof(AlignedCharArrayUnion<V8>));
242 #endif
243 }
244 } // end anonymous namespace
245