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