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#include "llvm/Support/AlignOf.h"
11#include "llvm/Support/Compiler.h"
12
13#include "gtest/gtest.h"
14
15using namespace llvm;
16
17namespace {
18
19// Disable warnings about questionable type definitions.
20// We're testing that even questionable types work with the alignment utilities.
21#ifdef _MSC_VER
22#pragma warning(disable:4584)
23#endif
24
25// Define some fixed alignment types to use in these tests.
26#if __cplusplus == 201103L || __has_feature(cxx_alignas)
27typedef char alignas(1) A1;
28typedef char alignas(2) A2;
29typedef char alignas(4) A4;
30typedef char alignas(8) A8;
31#elif defined(__clang__) || defined(__GNUC__)
32typedef char A1 __attribute__((aligned(1)));
33typedef char A2 __attribute__((aligned(2)));
34typedef char A4 __attribute__((aligned(4)));
35typedef char A8 __attribute__((aligned(8)));
36#elif defined(_MSC_VER)
37typedef __declspec(align(1)) char A1;
38typedef __declspec(align(2)) char A2;
39typedef __declspec(align(4)) char A4;
40typedef __declspec(align(8)) char A8;
41#else
42# error No supported align as directive.
43#endif
44
45// Wrap the forced aligned types in structs to hack around compiler bugs.
46struct SA1 { A1 a; };
47struct SA2 { A2 a; };
48struct SA4 { A4 a; };
49struct SA8 { A8 a; };
50
51struct S1 {};
52struct S2 { char a; };
53struct S3 { int x; };
54struct S4 { double y; };
55struct S5 { A1 a1; A2 a2; A4 a4; A8 a8; };
56struct S6 { double f(); };
57struct D1 : S1 {};
58struct D2 : S6 { float g(); };
59struct D3 : S2 {};
60struct D4 : S2 { int x; };
61struct D5 : S3 { char c; };
62struct D6 : S2, S3 {};
63struct D7 : S1, S3 {};
64struct D8 : S1, D4, D5 { double x[2]; };
65struct D9 : S1, D1 { S1 s1; };
66struct V1 { virtual ~V1(); };
67struct V2 { int x; virtual ~V2(); };
68struct V3 : V1 { virtual ~V3(); };
69struct V4 : virtual V2 { int y; virtual ~V4(); };
70struct V5 : V4, V3 { double z; virtual ~V5(); };
71struct V6 : S1 { virtual ~V6(); };
72struct V7 : virtual V2, virtual V6 { virtual ~V7(); };
73struct V8 : V5, virtual V6, V7 { double zz; virtual ~V8(); };
74
75// Ensure alignment is a compile-time constant.
76char LLVM_ATTRIBUTE_UNUSED test_arr1
77  [AlignOf<char>::Alignment > 0]
78  [AlignOf<short>::Alignment > 0]
79  [AlignOf<int>::Alignment > 0]
80  [AlignOf<long>::Alignment > 0]
81  [AlignOf<long long>::Alignment > 0]
82  [AlignOf<float>::Alignment > 0]
83  [AlignOf<double>::Alignment > 0]
84  [AlignOf<long double>::Alignment > 0]
85  [AlignOf<void *>::Alignment > 0]
86  [AlignOf<int *>::Alignment > 0]
87  [AlignOf<double (*)(double)>::Alignment > 0]
88  [AlignOf<double (S6::*)()>::Alignment > 0];
89char LLVM_ATTRIBUTE_UNUSED test_arr2
90  [AlignOf<A1>::Alignment > 0]
91  [AlignOf<A2>::Alignment > 0]
92  [AlignOf<A4>::Alignment > 0]
93  [AlignOf<A8>::Alignment > 0]
94  [AlignOf<SA1>::Alignment > 0]
95  [AlignOf<SA2>::Alignment > 0]
96  [AlignOf<SA4>::Alignment > 0]
97  [AlignOf<SA8>::Alignment > 0];
98char LLVM_ATTRIBUTE_UNUSED test_arr3
99  [AlignOf<S1>::Alignment > 0]
100  [AlignOf<S2>::Alignment > 0]
101  [AlignOf<S3>::Alignment > 0]
102  [AlignOf<S4>::Alignment > 0]
103  [AlignOf<S5>::Alignment > 0]
104  [AlignOf<S6>::Alignment > 0];
105char LLVM_ATTRIBUTE_UNUSED test_arr4
106  [AlignOf<D1>::Alignment > 0]
107  [AlignOf<D2>::Alignment > 0]
108  [AlignOf<D3>::Alignment > 0]
109  [AlignOf<D4>::Alignment > 0]
110  [AlignOf<D5>::Alignment > 0]
111  [AlignOf<D6>::Alignment > 0]
112  [AlignOf<D7>::Alignment > 0]
113  [AlignOf<D8>::Alignment > 0]
114  [AlignOf<D9>::Alignment > 0];
115char LLVM_ATTRIBUTE_UNUSED test_arr5
116  [AlignOf<V1>::Alignment > 0]
117  [AlignOf<V2>::Alignment > 0]
118  [AlignOf<V3>::Alignment > 0]
119  [AlignOf<V4>::Alignment > 0]
120  [AlignOf<V5>::Alignment > 0]
121  [AlignOf<V6>::Alignment > 0]
122  [AlignOf<V7>::Alignment > 0]
123  [AlignOf<V8>::Alignment > 0];
124
125TEST(AlignOfTest, BasicAlignmentInvariants) {
126  // For a very strange reason, many compilers do not support this. Both Clang
127  // and GCC fail to align these properly.
128  EXPECT_EQ(1u, alignOf<A1>());
129#if 0
130  EXPECT_EQ(2u, alignOf<A2>());
131  EXPECT_EQ(4u, alignOf<A4>());
132  EXPECT_EQ(8u, alignOf<A8>());
133#endif
134
135  // But once wrapped in structs, the alignment is correctly managed.
136  EXPECT_LE(1u, alignOf<SA1>());
137  EXPECT_LE(2u, alignOf<SA2>());
138  EXPECT_LE(4u, alignOf<SA4>());
139  EXPECT_LE(8u, alignOf<SA8>());
140
141  EXPECT_EQ(1u, alignOf<char>());
142  EXPECT_LE(alignOf<char>(),   alignOf<short>());
143  EXPECT_LE(alignOf<short>(),  alignOf<int>());
144  EXPECT_LE(alignOf<int>(),    alignOf<long>());
145  EXPECT_LE(alignOf<long>(),   alignOf<long long>());
146  EXPECT_LE(alignOf<char>(),   alignOf<float>());
147  EXPECT_LE(alignOf<float>(),  alignOf<double>());
148  EXPECT_LE(alignOf<char>(),   alignOf<long double>());
149  EXPECT_LE(alignOf<char>(),   alignOf<void *>());
150  EXPECT_EQ(alignOf<void *>(), alignOf<int *>());
151  EXPECT_LE(alignOf<char>(),   alignOf<S1>());
152  EXPECT_LE(alignOf<S1>(),     alignOf<S2>());
153  EXPECT_LE(alignOf<S1>(),     alignOf<S3>());
154  EXPECT_LE(alignOf<S1>(),     alignOf<S4>());
155  EXPECT_LE(alignOf<S1>(),     alignOf<S5>());
156  EXPECT_LE(alignOf<S1>(),     alignOf<S6>());
157  EXPECT_LE(alignOf<S1>(),     alignOf<D1>());
158  EXPECT_LE(alignOf<S1>(),     alignOf<D2>());
159  EXPECT_LE(alignOf<S1>(),     alignOf<D3>());
160  EXPECT_LE(alignOf<S1>(),     alignOf<D4>());
161  EXPECT_LE(alignOf<S1>(),     alignOf<D5>());
162  EXPECT_LE(alignOf<S1>(),     alignOf<D6>());
163  EXPECT_LE(alignOf<S1>(),     alignOf<D7>());
164  EXPECT_LE(alignOf<S1>(),     alignOf<D8>());
165  EXPECT_LE(alignOf<S1>(),     alignOf<D9>());
166  EXPECT_LE(alignOf<S1>(),     alignOf<V1>());
167  EXPECT_LE(alignOf<V1>(),     alignOf<V2>());
168  EXPECT_LE(alignOf<V1>(),     alignOf<V3>());
169  EXPECT_LE(alignOf<V1>(),     alignOf<V4>());
170  EXPECT_LE(alignOf<V1>(),     alignOf<V5>());
171  EXPECT_LE(alignOf<V1>(),     alignOf<V6>());
172  EXPECT_LE(alignOf<V1>(),     alignOf<V7>());
173  EXPECT_LE(alignOf<V1>(),     alignOf<V8>());
174}
175
176TEST(AlignOfTest, BasicAlignedArray) {
177  // Note: this code exclusively uses the struct-wrapped arbitrarily aligned
178  // types because of the bugs mentioned above where GCC and Clang both
179  // disregard the arbitrary alignment specifier until the type is used to
180  // declare a member of a struct.
181  EXPECT_LE(1u, alignOf<AlignedCharArrayUnion<SA1> >());
182  EXPECT_LE(2u, alignOf<AlignedCharArrayUnion<SA2> >());
183  EXPECT_LE(4u, alignOf<AlignedCharArrayUnion<SA4> >());
184  EXPECT_LE(8u, alignOf<AlignedCharArrayUnion<SA8> >());
185
186  EXPECT_LE(1u, sizeof(AlignedCharArrayUnion<SA1>));
187  EXPECT_LE(2u, sizeof(AlignedCharArrayUnion<SA2>));
188  EXPECT_LE(4u, sizeof(AlignedCharArrayUnion<SA4>));
189  EXPECT_LE(8u, sizeof(AlignedCharArrayUnion<SA8>));
190
191  EXPECT_EQ(1u, (alignOf<AlignedCharArrayUnion<SA1> >()));
192  EXPECT_EQ(2u, (alignOf<AlignedCharArrayUnion<SA1, SA2> >()));
193  EXPECT_EQ(4u, (alignOf<AlignedCharArrayUnion<SA1, SA2, SA4> >()));
194  EXPECT_EQ(8u, (alignOf<AlignedCharArrayUnion<SA1, SA2, SA4, SA8> >()));
195
196  EXPECT_EQ(1u, sizeof(AlignedCharArrayUnion<SA1>));
197  EXPECT_EQ(2u, sizeof(AlignedCharArrayUnion<SA1, SA2>));
198  EXPECT_EQ(4u, sizeof(AlignedCharArrayUnion<SA1, SA2, SA4>));
199  EXPECT_EQ(8u, sizeof(AlignedCharArrayUnion<SA1, SA2, SA4, SA8>));
200
201  EXPECT_EQ(1u, (alignOf<AlignedCharArrayUnion<SA1[1]> >()));
202  EXPECT_EQ(2u, (alignOf<AlignedCharArrayUnion<SA1[2], SA2[1]> >()));
203  EXPECT_EQ(4u, (alignOf<AlignedCharArrayUnion<SA1[42], SA2[55],
204                                               SA4[13]> >()));
205  EXPECT_EQ(8u, (alignOf<AlignedCharArrayUnion<SA1[2], SA2[1],
206                                               SA4, SA8> >()));
207
208  EXPECT_EQ(1u,  sizeof(AlignedCharArrayUnion<SA1[1]>));
209  EXPECT_EQ(2u,  sizeof(AlignedCharArrayUnion<SA1[2], SA2[1]>));
210  EXPECT_EQ(4u,  sizeof(AlignedCharArrayUnion<SA1[3], SA2[2], SA4>));
211  EXPECT_EQ(16u, sizeof(AlignedCharArrayUnion<SA1, SA2[3],
212                                              SA4[3], SA8>));
213
214  // For other tests we simply assert that the alignment of the union mathes
215  // that of the fundamental type and hope that we have any weird type
216  // productions that would trigger bugs.
217  EXPECT_EQ(alignOf<char>(), alignOf<AlignedCharArrayUnion<char> >());
218  EXPECT_EQ(alignOf<short>(), alignOf<AlignedCharArrayUnion<short> >());
219  EXPECT_EQ(alignOf<int>(), alignOf<AlignedCharArrayUnion<int> >());
220  EXPECT_EQ(alignOf<long>(), alignOf<AlignedCharArrayUnion<long> >());
221  EXPECT_EQ(alignOf<long long>(),
222            alignOf<AlignedCharArrayUnion<long long> >());
223  EXPECT_EQ(alignOf<float>(), alignOf<AlignedCharArrayUnion<float> >());
224  EXPECT_EQ(alignOf<double>(), alignOf<AlignedCharArrayUnion<double> >());
225  EXPECT_EQ(alignOf<long double>(),
226            alignOf<AlignedCharArrayUnion<long double> >());
227  EXPECT_EQ(alignOf<void *>(), alignOf<AlignedCharArrayUnion<void *> >());
228  EXPECT_EQ(alignOf<int *>(), alignOf<AlignedCharArrayUnion<int *> >());
229  EXPECT_EQ(alignOf<double (*)(double)>(),
230            alignOf<AlignedCharArrayUnion<double (*)(double)> >());
231  EXPECT_EQ(alignOf<double (S6::*)()>(),
232            alignOf<AlignedCharArrayUnion<double (S6::*)()> >());
233  EXPECT_EQ(alignOf<S1>(), alignOf<AlignedCharArrayUnion<S1> >());
234  EXPECT_EQ(alignOf<S2>(), alignOf<AlignedCharArrayUnion<S2> >());
235  EXPECT_EQ(alignOf<S3>(), alignOf<AlignedCharArrayUnion<S3> >());
236  EXPECT_EQ(alignOf<S4>(), alignOf<AlignedCharArrayUnion<S4> >());
237  EXPECT_EQ(alignOf<S5>(), alignOf<AlignedCharArrayUnion<S5> >());
238  EXPECT_EQ(alignOf<S6>(), alignOf<AlignedCharArrayUnion<S6> >());
239  EXPECT_EQ(alignOf<D1>(), alignOf<AlignedCharArrayUnion<D1> >());
240  EXPECT_EQ(alignOf<D2>(), alignOf<AlignedCharArrayUnion<D2> >());
241  EXPECT_EQ(alignOf<D3>(), alignOf<AlignedCharArrayUnion<D3> >());
242  EXPECT_EQ(alignOf<D4>(), alignOf<AlignedCharArrayUnion<D4> >());
243  EXPECT_EQ(alignOf<D5>(), alignOf<AlignedCharArrayUnion<D5> >());
244  EXPECT_EQ(alignOf<D6>(), alignOf<AlignedCharArrayUnion<D6> >());
245  EXPECT_EQ(alignOf<D7>(), alignOf<AlignedCharArrayUnion<D7> >());
246  EXPECT_EQ(alignOf<D8>(), alignOf<AlignedCharArrayUnion<D8> >());
247  EXPECT_EQ(alignOf<D9>(), alignOf<AlignedCharArrayUnion<D9> >());
248  EXPECT_EQ(alignOf<V1>(), alignOf<AlignedCharArrayUnion<V1> >());
249  EXPECT_EQ(alignOf<V2>(), alignOf<AlignedCharArrayUnion<V2> >());
250  EXPECT_EQ(alignOf<V3>(), alignOf<AlignedCharArrayUnion<V3> >());
251  EXPECT_EQ(alignOf<V4>(), alignOf<AlignedCharArrayUnion<V4> >());
252  EXPECT_EQ(alignOf<V5>(), alignOf<AlignedCharArrayUnion<V5> >());
253  EXPECT_EQ(alignOf<V6>(), alignOf<AlignedCharArrayUnion<V6> >());
254  EXPECT_EQ(alignOf<V7>(), alignOf<AlignedCharArrayUnion<V7> >());
255
256  // Some versions of MSVC get this wrong somewhat disturbingly. The failure
257  // appears to be benign: alignOf<V8>() produces a preposterous value: 12
258#ifndef _MSC_VER
259  EXPECT_EQ(alignOf<V8>(), alignOf<AlignedCharArrayUnion<V8> >());
260#endif
261
262  EXPECT_EQ(sizeof(char), sizeof(AlignedCharArrayUnion<char>));
263  EXPECT_EQ(sizeof(char[1]), sizeof(AlignedCharArrayUnion<char[1]>));
264  EXPECT_EQ(sizeof(char[2]), sizeof(AlignedCharArrayUnion<char[2]>));
265  EXPECT_EQ(sizeof(char[3]), sizeof(AlignedCharArrayUnion<char[3]>));
266  EXPECT_EQ(sizeof(char[4]), sizeof(AlignedCharArrayUnion<char[4]>));
267  EXPECT_EQ(sizeof(char[5]), sizeof(AlignedCharArrayUnion<char[5]>));
268  EXPECT_EQ(sizeof(char[8]), sizeof(AlignedCharArrayUnion<char[8]>));
269  EXPECT_EQ(sizeof(char[13]), sizeof(AlignedCharArrayUnion<char[13]>));
270  EXPECT_EQ(sizeof(char[16]), sizeof(AlignedCharArrayUnion<char[16]>));
271  EXPECT_EQ(sizeof(char[21]), sizeof(AlignedCharArrayUnion<char[21]>));
272  EXPECT_EQ(sizeof(char[32]), sizeof(AlignedCharArrayUnion<char[32]>));
273  EXPECT_EQ(sizeof(short), sizeof(AlignedCharArrayUnion<short>));
274  EXPECT_EQ(sizeof(int), sizeof(AlignedCharArrayUnion<int>));
275  EXPECT_EQ(sizeof(long), sizeof(AlignedCharArrayUnion<long>));
276  EXPECT_EQ(sizeof(long long),
277            sizeof(AlignedCharArrayUnion<long long>));
278  EXPECT_EQ(sizeof(float), sizeof(AlignedCharArrayUnion<float>));
279  EXPECT_EQ(sizeof(double), sizeof(AlignedCharArrayUnion<double>));
280  EXPECT_EQ(sizeof(long double),
281            sizeof(AlignedCharArrayUnion<long double>));
282  EXPECT_EQ(sizeof(void *), sizeof(AlignedCharArrayUnion<void *>));
283  EXPECT_EQ(sizeof(int *), sizeof(AlignedCharArrayUnion<int *>));
284  EXPECT_EQ(sizeof(double (*)(double)),
285            sizeof(AlignedCharArrayUnion<double (*)(double)>));
286  EXPECT_EQ(sizeof(double (S6::*)()),
287            sizeof(AlignedCharArrayUnion<double (S6::*)()>));
288  EXPECT_EQ(sizeof(S1), sizeof(AlignedCharArrayUnion<S1>));
289  EXPECT_EQ(sizeof(S2), sizeof(AlignedCharArrayUnion<S2>));
290  EXPECT_EQ(sizeof(S3), sizeof(AlignedCharArrayUnion<S3>));
291  EXPECT_EQ(sizeof(S4), sizeof(AlignedCharArrayUnion<S4>));
292  EXPECT_EQ(sizeof(S5), sizeof(AlignedCharArrayUnion<S5>));
293  EXPECT_EQ(sizeof(S6), sizeof(AlignedCharArrayUnion<S6>));
294  EXPECT_EQ(sizeof(D1), sizeof(AlignedCharArrayUnion<D1>));
295  EXPECT_EQ(sizeof(D2), sizeof(AlignedCharArrayUnion<D2>));
296  EXPECT_EQ(sizeof(D3), sizeof(AlignedCharArrayUnion<D3>));
297  EXPECT_EQ(sizeof(D4), sizeof(AlignedCharArrayUnion<D4>));
298  EXPECT_EQ(sizeof(D5), sizeof(AlignedCharArrayUnion<D5>));
299  EXPECT_EQ(sizeof(D6), sizeof(AlignedCharArrayUnion<D6>));
300  EXPECT_EQ(sizeof(D7), sizeof(AlignedCharArrayUnion<D7>));
301  EXPECT_EQ(sizeof(D8), sizeof(AlignedCharArrayUnion<D8>));
302  EXPECT_EQ(sizeof(D9), sizeof(AlignedCharArrayUnion<D9>));
303  EXPECT_EQ(sizeof(D9[1]), sizeof(AlignedCharArrayUnion<D9[1]>));
304  EXPECT_EQ(sizeof(D9[2]), sizeof(AlignedCharArrayUnion<D9[2]>));
305  EXPECT_EQ(sizeof(D9[3]), sizeof(AlignedCharArrayUnion<D9[3]>));
306  EXPECT_EQ(sizeof(D9[4]), sizeof(AlignedCharArrayUnion<D9[4]>));
307  EXPECT_EQ(sizeof(D9[5]), sizeof(AlignedCharArrayUnion<D9[5]>));
308  EXPECT_EQ(sizeof(D9[8]), sizeof(AlignedCharArrayUnion<D9[8]>));
309  EXPECT_EQ(sizeof(D9[13]), sizeof(AlignedCharArrayUnion<D9[13]>));
310  EXPECT_EQ(sizeof(D9[16]), sizeof(AlignedCharArrayUnion<D9[16]>));
311  EXPECT_EQ(sizeof(D9[21]), sizeof(AlignedCharArrayUnion<D9[21]>));
312  EXPECT_EQ(sizeof(D9[32]), sizeof(AlignedCharArrayUnion<D9[32]>));
313  EXPECT_EQ(sizeof(V1), sizeof(AlignedCharArrayUnion<V1>));
314  EXPECT_EQ(sizeof(V2), sizeof(AlignedCharArrayUnion<V2>));
315  EXPECT_EQ(sizeof(V3), sizeof(AlignedCharArrayUnion<V3>));
316  EXPECT_EQ(sizeof(V4), sizeof(AlignedCharArrayUnion<V4>));
317  EXPECT_EQ(sizeof(V5), sizeof(AlignedCharArrayUnion<V5>));
318  EXPECT_EQ(sizeof(V6), sizeof(AlignedCharArrayUnion<V6>));
319  EXPECT_EQ(sizeof(V7), sizeof(AlignedCharArrayUnion<V7>));
320
321  // Some versions of MSVC also get this wrong. The failure again appears to be
322  // benign: sizeof(V8) is only 52 bytes, but our array reserves 56.
323#ifndef _MSC_VER
324  EXPECT_EQ(sizeof(V8), sizeof(AlignedCharArrayUnion<V8>));
325#endif
326}
327
328}
329