1 //===- IteratorTest.cpp - Unit tests for iterator utilities ---------------===//
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/ADT/STLExtras.h"
11 #include "llvm/ADT/SmallVector.h"
12 #include "llvm/ADT/iterator.h"
13 #include "gtest/gtest.h"
14 
15 using namespace llvm;
16 
17 namespace {
18 
19 template <int> struct Shadow;
20 
21 struct WeirdIter : std::iterator<std::input_iterator_tag, Shadow<0>, Shadow<1>,
22                                  Shadow<2>, Shadow<3>> {};
23 
24 struct AdaptedIter : iterator_adaptor_base<AdaptedIter, WeirdIter> {};
25 
26 // Test that iterator_adaptor_base forwards typedefs, if value_type is
27 // unchanged.
28 static_assert(std::is_same<typename AdaptedIter::value_type, Shadow<0>>::value,
29               "");
30 static_assert(
31     std::is_same<typename AdaptedIter::difference_type, Shadow<1>>::value, "");
32 static_assert(std::is_same<typename AdaptedIter::pointer, Shadow<2>>::value,
33               "");
34 static_assert(std::is_same<typename AdaptedIter::reference, Shadow<3>>::value,
35               "");
36 
37 TEST(PointeeIteratorTest, Basic) {
38   int arr[4] = {1, 2, 3, 4};
39   SmallVector<int *, 4> V;
40   V.push_back(&arr[0]);
41   V.push_back(&arr[1]);
42   V.push_back(&arr[2]);
43   V.push_back(&arr[3]);
44 
45   typedef pointee_iterator<SmallVectorImpl<int *>::const_iterator>
46       test_iterator;
47 
48   test_iterator Begin, End;
49   Begin = V.begin();
50   End = test_iterator(V.end());
51 
52   test_iterator I = Begin;
53   for (int i = 0; i < 4; ++i) {
54     EXPECT_EQ(*V[i], *I);
55 
56     EXPECT_EQ(I, Begin + i);
57     EXPECT_EQ(I, std::next(Begin, i));
58     test_iterator J = Begin;
59     J += i;
60     EXPECT_EQ(I, J);
61     EXPECT_EQ(*V[i], Begin[i]);
62 
63     EXPECT_NE(I, End);
64     EXPECT_GT(End, I);
65     EXPECT_LT(I, End);
66     EXPECT_GE(I, Begin);
67     EXPECT_LE(Begin, I);
68 
69     EXPECT_EQ(i, I - Begin);
70     EXPECT_EQ(i, std::distance(Begin, I));
71     EXPECT_EQ(Begin, I - i);
72 
73     test_iterator K = I++;
74     EXPECT_EQ(K, std::prev(I));
75   }
76   EXPECT_EQ(End, I);
77 }
78 
79 TEST(PointeeIteratorTest, SmartPointer) {
80   SmallVector<std::unique_ptr<int>, 4> V;
81   V.push_back(make_unique<int>(1));
82   V.push_back(make_unique<int>(2));
83   V.push_back(make_unique<int>(3));
84   V.push_back(make_unique<int>(4));
85 
86   typedef pointee_iterator<
87       SmallVectorImpl<std::unique_ptr<int>>::const_iterator>
88       test_iterator;
89 
90   test_iterator Begin, End;
91   Begin = V.begin();
92   End = test_iterator(V.end());
93 
94   test_iterator I = Begin;
95   for (int i = 0; i < 4; ++i) {
96     EXPECT_EQ(*V[i], *I);
97 
98     EXPECT_EQ(I, Begin + i);
99     EXPECT_EQ(I, std::next(Begin, i));
100     test_iterator J = Begin;
101     J += i;
102     EXPECT_EQ(I, J);
103     EXPECT_EQ(*V[i], Begin[i]);
104 
105     EXPECT_NE(I, End);
106     EXPECT_GT(End, I);
107     EXPECT_LT(I, End);
108     EXPECT_GE(I, Begin);
109     EXPECT_LE(Begin, I);
110 
111     EXPECT_EQ(i, I - Begin);
112     EXPECT_EQ(i, std::distance(Begin, I));
113     EXPECT_EQ(Begin, I - i);
114 
115     test_iterator K = I++;
116     EXPECT_EQ(K, std::prev(I));
117   }
118   EXPECT_EQ(End, I);
119 }
120 
121 TEST(FilterIteratorTest, Lambda) {
122   auto IsOdd = [](int N) { return N % 2 == 1; };
123   int A[] = {0, 1, 2, 3, 4, 5, 6};
124   auto Range = make_filter_range(A, IsOdd);
125   SmallVector<int, 3> Actual(Range.begin(), Range.end());
126   EXPECT_EQ((SmallVector<int, 3>{1, 3, 5}), Actual);
127 }
128 
129 TEST(FilterIteratorTest, CallableObject) {
130   int Counter = 0;
131   struct Callable {
132     int &Counter;
133 
134     Callable(int &Counter) : Counter(Counter) {}
135 
136     bool operator()(int N) {
137       Counter++;
138       return N % 2 == 1;
139     }
140   };
141   Callable IsOdd(Counter);
142   int A[] = {0, 1, 2, 3, 4, 5, 6};
143   auto Range = make_filter_range(A, IsOdd);
144   EXPECT_EQ(2, Counter);
145   SmallVector<int, 3> Actual(Range.begin(), Range.end());
146   EXPECT_GE(Counter, 7);
147   EXPECT_EQ((SmallVector<int, 3>{1, 3, 5}), Actual);
148 }
149 
150 TEST(FilterIteratorTest, FunctionPointer) {
151   bool (*IsOdd)(int) = [](int N) { return N % 2 == 1; };
152   int A[] = {0, 1, 2, 3, 4, 5, 6};
153   auto Range = make_filter_range(A, IsOdd);
154   SmallVector<int, 3> Actual(Range.begin(), Range.end());
155   EXPECT_EQ((SmallVector<int, 3>{1, 3, 5}), Actual);
156 }
157 
158 TEST(FilterIteratorTest, Composition) {
159   auto IsOdd = [](int N) { return N % 2 == 1; };
160   std::unique_ptr<int> A[] = {make_unique<int>(0), make_unique<int>(1),
161                               make_unique<int>(2), make_unique<int>(3),
162                               make_unique<int>(4), make_unique<int>(5),
163                               make_unique<int>(6)};
164   using PointeeIterator = pointee_iterator<std::unique_ptr<int> *>;
165   auto Range = make_filter_range(
166       make_range(PointeeIterator(std::begin(A)), PointeeIterator(std::end(A))),
167       IsOdd);
168   SmallVector<int, 3> Actual(Range.begin(), Range.end());
169   EXPECT_EQ((SmallVector<int, 3>{1, 3, 5}), Actual);
170 }
171 
172 TEST(FilterIteratorTest, InputIterator) {
173   struct InputIterator
174       : iterator_adaptor_base<InputIterator, int *, std::input_iterator_tag> {
175     using BaseT =
176         iterator_adaptor_base<InputIterator, int *, std::input_iterator_tag>;
177 
178     InputIterator(int *It) : BaseT(It) {}
179   };
180 
181   auto IsOdd = [](int N) { return N % 2 == 1; };
182   int A[] = {0, 1, 2, 3, 4, 5, 6};
183   auto Range = make_filter_range(
184       make_range(InputIterator(std::begin(A)), InputIterator(std::end(A))),
185       IsOdd);
186   SmallVector<int, 3> Actual(Range.begin(), Range.end());
187   EXPECT_EQ((SmallVector<int, 3>{1, 3, 5}), Actual);
188 }
189 
190 TEST(PointerIterator, Basic) {
191   int A[] = {1, 2, 3, 4};
192   pointer_iterator<int *> Begin(std::begin(A)), End(std::end(A));
193   EXPECT_EQ(A, *Begin);
194   ++Begin;
195   EXPECT_EQ(A + 1, *Begin);
196   ++Begin;
197   EXPECT_EQ(A + 2, *Begin);
198   ++Begin;
199   EXPECT_EQ(A + 3, *Begin);
200   ++Begin;
201   EXPECT_EQ(Begin, End);
202 }
203 
204 TEST(PointerIterator, Const) {
205   int A[] = {1, 2, 3, 4};
206   const pointer_iterator<int *> Begin(std::begin(A));
207   EXPECT_EQ(A, *Begin);
208   EXPECT_EQ(A + 1, std::next(*Begin, 1));
209   EXPECT_EQ(A + 2, std::next(*Begin, 2));
210   EXPECT_EQ(A + 3, std::next(*Begin, 3));
211   EXPECT_EQ(A + 4, std::next(*Begin, 4));
212 }
213 
214 TEST(ZipIteratorTest, Basic) {
215   using namespace std;
216   const SmallVector<unsigned, 6> pi{3, 1, 4, 1, 5, 9};
217   SmallVector<bool, 6> odd{1, 1, 0, 1, 1, 1};
218   const char message[] = "yynyyy\0";
219 
220   for (auto tup : zip(pi, odd, message)) {
221     EXPECT_EQ(get<0>(tup) & 0x01, get<1>(tup));
222     EXPECT_EQ(get<0>(tup) & 0x01 ? 'y' : 'n', get<2>(tup));
223   }
224 
225   // note the rvalue
226   for (auto tup : zip(pi, SmallVector<bool, 0>{1, 1, 0, 1, 1})) {
227     EXPECT_EQ(get<0>(tup) & 0x01, get<1>(tup));
228   }
229 }
230 
231 TEST(ZipIteratorTest, ZipFirstBasic) {
232   using namespace std;
233   const SmallVector<unsigned, 6> pi{3, 1, 4, 1, 5, 9};
234   unsigned iters = 0;
235 
236   for (auto tup : zip_first(SmallVector<bool, 0>{1, 1, 0, 1}, pi)) {
237     EXPECT_EQ(get<0>(tup), get<1>(tup) & 0x01);
238     iters += 1;
239   }
240 
241   EXPECT_EQ(iters, 4u);
242 }
243 
244 TEST(ZipIteratorTest, Mutability) {
245   using namespace std;
246   const SmallVector<unsigned, 4> pi{3, 1, 4, 1, 5, 9};
247   char message[] = "hello zip\0";
248 
249   for (auto tup : zip(pi, message, message)) {
250     EXPECT_EQ(get<1>(tup), get<2>(tup));
251     get<2>(tup) = get<0>(tup) & 0x01 ? 'y' : 'n';
252   }
253 
254   // note the rvalue
255   for (auto tup : zip(message, "yynyyyzip\0")) {
256     EXPECT_EQ(get<0>(tup), get<1>(tup));
257   }
258 }
259 
260 TEST(ZipIteratorTest, ZipFirstMutability) {
261   using namespace std;
262   vector<unsigned> pi{3, 1, 4, 1, 5, 9};
263   unsigned iters = 0;
264 
265   for (auto tup : zip_first(SmallVector<bool, 0>{1, 1, 0, 1}, pi)) {
266     get<1>(tup) = get<0>(tup);
267     iters += 1;
268   }
269 
270   EXPECT_EQ(iters, 4u);
271 
272   for (auto tup : zip_first(SmallVector<bool, 0>{1, 1, 0, 1}, pi)) {
273     EXPECT_EQ(get<0>(tup), get<1>(tup));
274   }
275 }
276 
277 TEST(ZipIteratorTest, Filter) {
278   using namespace std;
279   vector<unsigned> pi{3, 1, 4, 1, 5, 9};
280 
281   unsigned iters = 0;
282   // pi is length 6, but the zip RHS is length 7.
283   auto zipped = zip_first(pi, vector<bool>{1, 1, 0, 1, 1, 1, 0});
284   for (auto tup : make_filter_range(
285            zipped, [](decltype(zipped)::value_type t) { return get<1>(t); })) {
286     EXPECT_EQ(get<0>(tup) & 0x01, get<1>(tup));
287     get<0>(tup) += 1;
288     iters += 1;
289   }
290 
291   // Should have skipped pi[2].
292   EXPECT_EQ(iters, 5u);
293 
294   // Ensure that in-place mutation works.
295   EXPECT_TRUE(all_of(pi, [](unsigned n) { return (n & 0x01) == 0; }));
296 }
297 
298 TEST(ZipIteratorTest, Reverse) {
299   using namespace std;
300   vector<unsigned> ascending{0, 1, 2, 3, 4, 5};
301 
302   auto zipped = zip_first(ascending, vector<bool>{0, 1, 0, 1, 0, 1});
303   unsigned last = 6;
304   for (auto tup : reverse(zipped)) {
305     // Check that this is in reverse.
306     EXPECT_LT(get<0>(tup), last);
307     last = get<0>(tup);
308     EXPECT_EQ(get<0>(tup) & 0x01, get<1>(tup));
309   }
310 
311   auto odds = [](decltype(zipped)::value_type tup) { return get<1>(tup); };
312   last = 6;
313   for (auto tup : make_filter_range(reverse(zipped), odds)) {
314     EXPECT_LT(get<0>(tup), last);
315     last = get<0>(tup);
316     EXPECT_TRUE(get<0>(tup) & 0x01);
317     get<0>(tup) += 1;
318   }
319 
320   // Ensure that in-place mutation works.
321   EXPECT_TRUE(all_of(ascending, [](unsigned n) { return (n & 0x01) == 0; }));
322 }
323 
324 } // anonymous namespace
325