1 //=== - llvm/unittest/Support/TrailingObjectsTest.cpp ---------------------===//
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/TrailingObjects.h"
11 #include "gtest/gtest.h"
12 
13 using namespace llvm;
14 
15 namespace {
16 // This class, beyond being used by the test case, a nice
17 // demonstration of the intended usage of TrailingObjects, with a
18 // single trailing array.
19 class Class1 final : protected TrailingObjects<Class1, short> {
20   friend TrailingObjects;
21 
22   unsigned NumShorts;
23 
24 protected:
numTrailingObjects(OverloadToken<short>) const25   size_t numTrailingObjects(OverloadToken<short>) const { return NumShorts; }
26 
Class1(int * ShortArray,unsigned NumShorts)27   Class1(int *ShortArray, unsigned NumShorts) : NumShorts(NumShorts) {
28     std::uninitialized_copy(ShortArray, ShortArray + NumShorts,
29                             getTrailingObjects<short>());
30   }
31 
32 public:
create(int * ShortArray,unsigned NumShorts)33   static Class1 *create(int *ShortArray, unsigned NumShorts) {
34     void *Mem = ::operator new(totalSizeToAlloc<short>(NumShorts));
35     return new (Mem) Class1(ShortArray, NumShorts);
36   }
operator delete(void * p)37   void operator delete(void *p) { ::operator delete(p); }
38 
get(unsigned Num) const39   short get(unsigned Num) const { return getTrailingObjects<short>()[Num]; }
40 
numShorts() const41   unsigned numShorts() const { return NumShorts; }
42 
43   // Pull some protected members in as public, for testability.
44   template <typename... Ty>
45   using FixedSizeStorage = TrailingObjects::FixedSizeStorage<Ty...>;
46 
47   using TrailingObjects::totalSizeToAlloc;
48   using TrailingObjects::additionalSizeToAlloc;
49   using TrailingObjects::getTrailingObjects;
50 };
51 
52 // Here, there are two singular optional object types appended.  Note
53 // that the alignment of Class2 is automatically increased to account
54 // for the alignment requirements of the trailing objects.
55 class Class2 final : protected TrailingObjects<Class2, double, short> {
56   friend TrailingObjects;
57 
58   bool HasShort, HasDouble;
59 
60 protected:
numTrailingObjects(OverloadToken<short>) const61   size_t numTrailingObjects(OverloadToken<short>) const {
62     return HasShort ? 1 : 0;
63   }
numTrailingObjects(OverloadToken<double>) const64   size_t numTrailingObjects(OverloadToken<double>) const {
65     return HasDouble ? 1 : 0;
66   }
67 
Class2(bool HasShort,bool HasDouble)68   Class2(bool HasShort, bool HasDouble)
69       : HasShort(HasShort), HasDouble(HasDouble) {}
70 
71 public:
create(short S=0,double D=0.0)72   static Class2 *create(short S = 0, double D = 0.0) {
73     bool HasShort = S != 0;
74     bool HasDouble = D != 0.0;
75 
76     void *Mem =
77         ::operator new(totalSizeToAlloc<double, short>(HasDouble, HasShort));
78     Class2 *C = new (Mem) Class2(HasShort, HasDouble);
79     if (HasShort)
80       *C->getTrailingObjects<short>() = S;
81     if (HasDouble)
82       *C->getTrailingObjects<double>() = D;
83     return C;
84   }
operator delete(void * p)85   void operator delete(void *p) { ::operator delete(p); }
86 
getShort() const87   short getShort() const {
88     if (!HasShort)
89       return 0;
90     return *getTrailingObjects<short>();
91   }
92 
getDouble() const93   double getDouble() const {
94     if (!HasDouble)
95       return 0.0;
96     return *getTrailingObjects<double>();
97   }
98 
99   // Pull some protected members in as public, for testability.
100   template <typename... Ty>
101   using FixedSizeStorage = TrailingObjects::FixedSizeStorage<Ty...>;
102 
103   using TrailingObjects::totalSizeToAlloc;
104   using TrailingObjects::additionalSizeToAlloc;
105   using TrailingObjects::getTrailingObjects;
106 };
107 
TEST(TrailingObjects,OneArg)108 TEST(TrailingObjects, OneArg) {
109   int arr[] = {1, 2, 3};
110   Class1 *C = Class1::create(arr, 3);
111   EXPECT_EQ(sizeof(Class1), sizeof(unsigned));
112   EXPECT_EQ(Class1::additionalSizeToAlloc<short>(1), sizeof(short));
113   EXPECT_EQ(Class1::additionalSizeToAlloc<short>(3), sizeof(short) * 3);
114 
115   EXPECT_EQ(alignof(Class1),
116             alignof(Class1::FixedSizeStorage<short>::with_counts<1>::type));
117   EXPECT_EQ(sizeof(Class1::FixedSizeStorage<short>::with_counts<1>::type),
118             llvm::alignTo(Class1::totalSizeToAlloc<short>(1), alignof(Class1)));
119   EXPECT_EQ(Class1::totalSizeToAlloc<short>(1), sizeof(Class1) + sizeof(short));
120 
121   EXPECT_EQ(alignof(Class1),
122             alignof(Class1::FixedSizeStorage<short>::with_counts<3>::type));
123   EXPECT_EQ(sizeof(Class1::FixedSizeStorage<short>::with_counts<3>::type),
124             llvm::alignTo(Class1::totalSizeToAlloc<short>(3), alignof(Class1)));
125   EXPECT_EQ(Class1::totalSizeToAlloc<short>(3),
126             sizeof(Class1) + sizeof(short) * 3);
127 
128   EXPECT_EQ(C->getTrailingObjects<short>(), reinterpret_cast<short *>(C + 1));
129   EXPECT_EQ(C->get(0), 1);
130   EXPECT_EQ(C->get(2), 3);
131   delete C;
132 }
133 
TEST(TrailingObjects,TwoArg)134 TEST(TrailingObjects, TwoArg) {
135   Class2 *C1 = Class2::create(4);
136   Class2 *C2 = Class2::create(0, 4.2);
137 
138   EXPECT_EQ(sizeof(Class2), llvm::alignTo(sizeof(bool) * 2, alignof(double)));
139   EXPECT_EQ(alignof(Class2), alignof(double));
140 
141   EXPECT_EQ((Class2::additionalSizeToAlloc<double, short>(1, 0)),
142             sizeof(double));
143   EXPECT_EQ((Class2::additionalSizeToAlloc<double, short>(0, 1)),
144             sizeof(short));
145   EXPECT_EQ((Class2::additionalSizeToAlloc<double, short>(3, 1)),
146             sizeof(double) * 3 + sizeof(short));
147 
148   EXPECT_EQ(
149       alignof(Class2),
150       (alignof(
151           Class2::FixedSizeStorage<double, short>::with_counts<1, 1>::type)));
152   EXPECT_EQ(
153       sizeof(Class2::FixedSizeStorage<double, short>::with_counts<1, 1>::type),
154       llvm::alignTo(Class2::totalSizeToAlloc<double, short>(1, 1),
155                     alignof(Class2)));
156   EXPECT_EQ((Class2::totalSizeToAlloc<double, short>(1, 1)),
157             sizeof(Class2) + sizeof(double) + sizeof(short));
158 
159   EXPECT_EQ(C1->getDouble(), 0);
160   EXPECT_EQ(C1->getShort(), 4);
161   EXPECT_EQ(C1->getTrailingObjects<double>(),
162             reinterpret_cast<double *>(C1 + 1));
163   EXPECT_EQ(C1->getTrailingObjects<short>(), reinterpret_cast<short *>(C1 + 1));
164 
165   EXPECT_EQ(C2->getDouble(), 4.2);
166   EXPECT_EQ(C2->getShort(), 0);
167   EXPECT_EQ(C2->getTrailingObjects<double>(),
168             reinterpret_cast<double *>(C2 + 1));
169   EXPECT_EQ(C2->getTrailingObjects<short>(),
170             reinterpret_cast<short *>(reinterpret_cast<double *>(C2 + 1) + 1));
171   delete C1;
172   delete C2;
173 }
174 
175 // This test class is not trying to be a usage demo, just asserting
176 // that three args does actually work too (it's the same code as
177 // handles the second arg, so it's basically covered by the above, but
178 // just in case..)
179 class Class3 final : public TrailingObjects<Class3, double, short, bool> {
180   friend TrailingObjects;
181 
numTrailingObjects(OverloadToken<double>) const182   size_t numTrailingObjects(OverloadToken<double>) const { return 1; }
numTrailingObjects(OverloadToken<short>) const183   size_t numTrailingObjects(OverloadToken<short>) const { return 1; }
184 };
185 
TEST(TrailingObjects,ThreeArg)186 TEST(TrailingObjects, ThreeArg) {
187   EXPECT_EQ((Class3::additionalSizeToAlloc<double, short, bool>(1, 1, 3)),
188             sizeof(double) + sizeof(short) + 3 * sizeof(bool));
189   EXPECT_EQ(sizeof(Class3), llvm::alignTo(1, alignof(double)));
190 
191   EXPECT_EQ(
192       alignof(Class3),
193       (alignof(Class3::FixedSizeStorage<double, short,
194                                         bool>::with_counts<1, 1, 3>::type)));
195   EXPECT_EQ(
196       sizeof(Class3::FixedSizeStorage<double, short,
197                                       bool>::with_counts<1, 1, 3>::type),
198       llvm::alignTo(Class3::totalSizeToAlloc<double, short, bool>(1, 1, 3),
199                     alignof(Class3)));
200 
201   std::unique_ptr<char[]> P(new char[1000]);
202   Class3 *C = reinterpret_cast<Class3 *>(P.get());
203   EXPECT_EQ(C->getTrailingObjects<double>(), reinterpret_cast<double *>(C + 1));
204   EXPECT_EQ(C->getTrailingObjects<short>(),
205             reinterpret_cast<short *>(reinterpret_cast<double *>(C + 1) + 1));
206   EXPECT_EQ(
207       C->getTrailingObjects<bool>(),
208       reinterpret_cast<bool *>(
209           reinterpret_cast<short *>(reinterpret_cast<double *>(C + 1) + 1) +
210           1));
211 }
212 
213 class Class4 final : public TrailingObjects<Class4, char, long> {
214   friend TrailingObjects;
numTrailingObjects(OverloadToken<char>) const215   size_t numTrailingObjects(OverloadToken<char>) const { return 1; }
216 };
217 
TEST(TrailingObjects,Realignment)218 TEST(TrailingObjects, Realignment) {
219   EXPECT_EQ((Class4::additionalSizeToAlloc<char, long>(1, 1)),
220             llvm::alignTo(sizeof(long) + 1, alignof(long)));
221   EXPECT_EQ(sizeof(Class4), llvm::alignTo(1, alignof(long)));
222 
223   EXPECT_EQ(
224       alignof(Class4),
225       (alignof(Class4::FixedSizeStorage<char, long>::with_counts<1, 1>::type)));
226   EXPECT_EQ(
227       sizeof(Class4::FixedSizeStorage<char, long>::with_counts<1, 1>::type),
228       llvm::alignTo(Class4::totalSizeToAlloc<char, long>(1, 1),
229                     alignof(Class4)));
230 
231   std::unique_ptr<char[]> P(new char[1000]);
232   Class4 *C = reinterpret_cast<Class4 *>(P.get());
233   EXPECT_EQ(C->getTrailingObjects<char>(), reinterpret_cast<char *>(C + 1));
234   EXPECT_EQ(C->getTrailingObjects<long>(),
235             reinterpret_cast<long *>(llvm::alignAddr(
236                 reinterpret_cast<char *>(C + 1) + 1, alignof(long))));
237 }
238 }
239 
240 // Test the use of TrailingObjects with a template class. This
241 // previously failed to compile due to a bug in MSVC's member access
242 // control/lookup handling for OverloadToken.
243 template <typename Derived>
244 class Class5Tmpl : private llvm::TrailingObjects<Derived, float, int> {
245   using TrailingObjects = typename llvm::TrailingObjects<Derived, float>;
246   friend TrailingObjects;
247 
numTrailingObjects(typename TrailingObjects::template OverloadToken<float>) const248   size_t numTrailingObjects(
249       typename TrailingObjects::template OverloadToken<float>) const {
250     return 1;
251   }
252 
numTrailingObjects(typename TrailingObjects::template OverloadToken<int>) const253   size_t numTrailingObjects(
254       typename TrailingObjects::template OverloadToken<int>) const {
255     return 2;
256   }
257 };
258 
259 class Class5 : public Class5Tmpl<Class5> {};
260