modernize-use-emplace.cpp
16.4 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
// RUN: %check_clang_tidy %s modernize-use-emplace %t -- \
// RUN: -config="{CheckOptions: \
// RUN: [{key: modernize-use-emplace.ContainersWithPushBack, \
// RUN: value: '::std::vector; ::std::list; ::std::deque; llvm::LikeASmallVector'}, \
// RUN: {key: modernize-use-emplace.TupleTypes, \
// RUN: value: '::std::pair; std::tuple; ::test::Single'}, \
// RUN: {key: modernize-use-emplace.TupleMakeFunctions, \
// RUN: value: '::std::make_pair; ::std::make_tuple; ::test::MakeSingle'}] \
// RUN: }"
namespace std {
template <typename>
class initializer_list
{
public:
initializer_list() noexcept {}
};
template <typename T>
class vector {
public:
vector() = default;
vector(initializer_list<T>) {}
void push_back(const T &) {}
void push_back(T &&) {}
template <typename... Args>
void emplace_back(Args &&... args){};
~vector();
};
template <typename T>
class list {
public:
void push_back(const T &) {}
void push_back(T &&) {}
template <typename... Args>
void emplace_back(Args &&... args){};
~list();
};
template <typename T>
class deque {
public:
void push_back(const T &) {}
void push_back(T &&) {}
template <typename... Args>
void emplace_back(Args &&... args){};
~deque();
};
template <typename T> struct remove_reference { using type = T; };
template <typename T> struct remove_reference<T &> { using type = T; };
template <typename T> struct remove_reference<T &&> { using type = T; };
template <typename T1, typename T2> class pair {
public:
pair() = default;
pair(const pair &) = default;
pair(pair &&) = default;
pair(const T1 &, const T2 &) {}
pair(T1 &&, T2 &&) {}
template <typename U1, typename U2> pair(const pair<U1, U2> &){};
template <typename U1, typename U2> pair(pair<U1, U2> &&){};
};
template <typename T1, typename T2>
pair<typename remove_reference<T1>::type, typename remove_reference<T2>::type>
make_pair(T1 &&, T2 &&) {
return {};
};
template <typename... Ts> class tuple {
public:
tuple() = default;
tuple(const tuple &) = default;
tuple(tuple &&) = default;
tuple(const Ts &...) {}
tuple(Ts &&...) {}
template <typename... Us> tuple(const tuple<Us...> &){};
template <typename... Us> tuple(tuple<Us...> &&) {}
template <typename U1, typename U2> tuple(const pair<U1, U2> &) {
static_assert(sizeof...(Ts) == 2, "Wrong tuple size");
};
template <typename U1, typename U2> tuple(pair<U1, U2> &&) {
static_assert(sizeof...(Ts) == 2, "Wrong tuple size");
};
};
template <typename... Ts>
tuple<typename remove_reference<Ts>::type...> make_tuple(Ts &&...) {
return {};
}
template <typename T>
class unique_ptr {
public:
explicit unique_ptr(T *) {}
~unique_ptr();
};
} // namespace std
namespace llvm {
template <typename T>
class LikeASmallVector {
public:
void push_back(const T &) {}
void push_back(T &&) {}
template <typename... Args>
void emplace_back(Args &&... args){};
};
} // llvm
void testInts() {
std::vector<int> v;
v.push_back(42);
v.push_back(int(42));
v.push_back(int{42});
v.push_back(42.0);
int z;
v.push_back(z);
}
struct Something {
Something(int a, int b = 41) {}
Something() {}
void push_back(Something);
int getInt() { return 42; }
};
struct Convertable {
operator Something() { return Something{}; }
};
struct Zoz {
Zoz(Something, int = 42) {}
};
Zoz getZoz(Something s) { return Zoz(s); }
void test_Something() {
std::vector<Something> v;
v.push_back(Something(1, 2));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back instead of push_back [modernize-use-emplace]
// CHECK-FIXES: v.emplace_back(1, 2);
v.push_back(Something{1, 2});
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, 2);
v.push_back(Something());
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back();
v.push_back(Something{});
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back();
Something Different;
v.push_back(Something(Different.getInt(), 42));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(Different.getInt(), 42);
v.push_back(Different.getInt());
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(Different.getInt());
v.push_back(42);
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(42);
Something temporary(42, 42);
temporary.push_back(temporary);
v.push_back(temporary);
v.push_back(Convertable());
v.push_back(Convertable{});
Convertable s;
v.push_back(s);
}
template <typename ElemType>
void dependOnElem() {
std::vector<ElemType> v;
v.push_back(ElemType(42));
}
template <typename ContainerType>
void dependOnContainer() {
ContainerType v;
v.push_back(Something(42));
}
void callDependent() {
dependOnElem<Something>();
dependOnContainer<std::vector<Something>>();
}
void test2() {
std::vector<Zoz> v;
v.push_back(Zoz(Something(21, 37)));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(Something(21, 37));
v.push_back(Zoz(Something(21, 37), 42));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(Something(21, 37), 42);
v.push_back(getZoz(Something(1, 2)));
}
struct GetPair {
std::pair<int, long> getPair();
};
void testPair() {
std::vector<std::pair<int, int>> v;
v.push_back(std::pair<int, int>(1, 2));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, 2);
GetPair g;
v.push_back(g.getPair());
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(g.getPair());
std::vector<std::pair<Something, Zoz>> v2;
v2.push_back(std::pair<Something, Zoz>(Something(42, 42), Zoz(Something(21, 37))));
// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use emplace_back
// CHECK-FIXES: v2.emplace_back(Something(42, 42), Zoz(Something(21, 37)));
}
void testTuple() {
std::vector<std::tuple<bool, char, int>> v;
v.push_back(std::tuple<bool, char, int>(false, 'x', 1));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(false, 'x', 1);
v.push_back(std::tuple<bool, char, int>{false, 'y', 2});
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(false, 'y', 2);
v.push_back({true, 'z', 3});
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(true, 'z', 3);
std::vector<std::tuple<int, bool>> x;
x.push_back(std::make_pair(1, false));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: x.emplace_back(1, false);
x.push_back(std::make_pair(2LL, 1));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: x.emplace_back(2LL, 1);
}
struct Base {
Base(int, int *, int = 42);
};
struct Derived : Base {
Derived(int *, Something) : Base(42, nullptr) {}
};
void testDerived() {
std::vector<Base> v;
v.push_back(Derived(nullptr, Something{}));
}
void testNewExpr() {
std::vector<Derived> v;
v.push_back(Derived(new int, Something{}));
}
void testSpaces() {
std::vector<Something> v;
// clang-format off
v.push_back(Something(1, //arg1
2 // arg2
) // Something
);
// CHECK-MESSAGES: :[[@LINE-4]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, //arg1
// CHECK-FIXES: 2 // arg2
// CHECK-FIXES: // Something
// CHECK-FIXES: );
v.push_back( Something (1, 2) );
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, 2 );
v.push_back( Something {1, 2} );
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, 2 );
v.push_back( Something {} );
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back( );
v.push_back(
Something(1, 2) );
// CHECK-MESSAGES: :[[@LINE-2]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, 2 );
std::vector<Base> v2;
v2.push_back(
Base(42, nullptr));
// CHECK-MESSAGES: :[[@LINE-2]]:6: warning: use emplace_back
// CHECK-FIXES: v2.emplace_back(42, nullptr);
// clang-format on
}
void testPointers() {
std::vector<int *> v;
v.push_back(new int(5));
std::vector<std::unique_ptr<int>> v2;
v2.push_back(std::unique_ptr<int>(new int(42)));
// This call can't be replaced with emplace_back.
// If emplacement will fail (not enough memory to add to vector)
// we will have leak of int because unique_ptr won't be constructed
// (and destructed) as in push_back case.
auto *ptr = new int;
v2.push_back(std::unique_ptr<int>(ptr));
// Same here
}
void testMakePair() {
std::vector<std::pair<int, int>> v;
v.push_back(std::make_pair(1, 2));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, 2);
v.push_back(std::make_pair(42LL, 13));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(42LL, 13);
v.push_back(std::make_pair<char, char>(0, 3));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(std::make_pair<char, char>(0, 3));
//
// Even though the call above could be turned into v.emplace_back(0, 3),
// we don't eliminate the make_pair call here, because of the explicit
// template parameters provided. make_pair's arguments can be convertible
// to its explicitly provided template parameter, but not to the pair's
// element type. The examples below illustrate the problem.
struct D {
D(...) {}
operator char() const { return 0; }
};
v.push_back(std::make_pair<D, int>(Something(), 2));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(std::make_pair<D, int>(Something(), 2));
struct X {
X(std::pair<int, int>) {}
};
std::vector<X> x;
x.push_back(std::make_pair(1, 2));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: x.emplace_back(std::make_pair(1, 2));
// make_pair cannot be removed here, as X is not constructible with two ints.
struct Y {
Y(std::pair<int, int>&&) {}
};
std::vector<Y> y;
y.push_back(std::make_pair(2, 3));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: y.emplace_back(std::make_pair(2, 3));
// make_pair cannot be removed here, as Y is not constructible with two ints.
}
void testMakeTuple() {
std::vector<std::tuple<int, bool, char>> v;
v.push_back(std::make_tuple(1, true, 'v'));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1, true, 'v');
v.push_back(std::make_tuple(2ULL, 1, 0));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(2ULL, 1, 0);
v.push_back(std::make_tuple<long long, int, int>(3LL, 1, 0));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(std::make_tuple<long long, int, int>(3LL, 1, 0));
// make_tuple is not removed when there are explicit template
// arguments provided.
}
namespace test {
template <typename T> struct Single {
Single() = default;
Single(const Single &) = default;
Single(Single &&) = default;
Single(const T &) {}
Single(T &&) {}
template <typename U> Single(const Single<U> &) {}
template <typename U> Single(Single<U> &&) {}
template <typename U> Single(const std::tuple<U> &) {}
template <typename U> Single(std::tuple<U> &&) {}
};
template <typename T>
Single<typename std::remove_reference<T>::type> MakeSingle(T &&) {
return {};
}
} // namespace test
void testOtherTuples() {
std::vector<test::Single<int>> v;
v.push_back(test::Single<int>(1));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(1);
v.push_back({2});
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(2);
v.push_back(test::MakeSingle(3));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(3);
v.push_back(test::MakeSingle<long long>(4));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(test::MakeSingle<long long>(4));
// We don't remove make functions with explicit template parameters.
v.push_back(test::MakeSingle(5LL));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(5LL);
v.push_back(std::make_tuple(6));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(6);
v.push_back(std::make_tuple(7LL));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(7LL);
}
void testOtherContainers() {
std::list<Something> l;
l.push_back(Something(42, 41));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: l.emplace_back(42, 41);
std::deque<Something> d;
d.push_back(Something(42));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: d.emplace_back(42);
llvm::LikeASmallVector<Something> ls;
ls.push_back(Something(42));
// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use emplace_back
// CHECK-FIXES: ls.emplace_back(42);
}
class IntWrapper {
public:
IntWrapper(int x) : value(x) {}
IntWrapper operator+(const IntWrapper other) const {
return IntWrapper(value + other.value);
}
private:
int value;
};
void testMultipleOpsInPushBack() {
std::vector<IntWrapper> v;
v.push_back(IntWrapper(42) + IntWrapper(27));
}
// Macro tests.
#define PUSH_BACK_WHOLE(c, x) c.push_back(x)
#define PUSH_BACK_NAME push_back
#define PUSH_BACK_ARG(x) (x)
#define SOME_OBJ Something(10)
#define MILLION 3
#define SOME_WEIRD_PUSH(v) v.push_back(Something(
#define OPEN (
#define CLOSE )
void macroTest() {
std::vector<Something> v;
Something s;
PUSH_BACK_WHOLE(v, Something(5, 6));
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use emplace_back
v.PUSH_BACK_NAME(Something(5));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
v.push_back PUSH_BACK_ARG(Something(5, 6));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
v.push_back(SOME_OBJ);
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
v.push_back(Something(MILLION));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(MILLION);
// clang-format off
v.push_back( Something OPEN 3 CLOSE );
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// clang-format on
PUSH_BACK_WHOLE(s, Something(1));
}
struct A {
int value1, value2;
};
struct B {
B(A) {}
};
struct C {
int value1, value2, value3;
};
void testAggregation() {
// This should not be noticed or fixed; after the correction, the code won't
// compile.
std::vector<A> v;
v.push_back(A({1, 2}));
std::vector<B> vb;
vb.push_back(B({10, 42}));
}
struct Bitfield {
unsigned bitfield : 1;
unsigned notBitfield;
};
void testBitfields() {
std::vector<Something> v;
Bitfield b;
v.push_back(Something(42, b.bitfield));
v.push_back(Something(b.bitfield));
v.push_back(Something(42, b.notBitfield));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(42, b.notBitfield);
int var;
v.push_back(Something(42, var));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(42, var);
}
class PrivateCtor {
PrivateCtor(int z);
public:
void doStuff() {
std::vector<PrivateCtor> v;
// This should not change it because emplace back doesn't have permission.
// Check currently doesn't support friend declarations because pretty much
// nobody would want to be friend with std::vector :(.
v.push_back(PrivateCtor(42));
}
};
struct WithDtor {
WithDtor(int) {}
~WithDtor();
};
void testWithDtor() {
std::vector<WithDtor> v;
v.push_back(WithDtor(42));
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: use emplace_back
// CHECK-FIXES: v.emplace_back(42);
}
void testInitializerList() {
std::vector<std::vector<int>> v;
v.push_back(std::vector<int>({1}));
// Test against the bug reported in PR32896.
v.push_back({{2}});
using PairIntVector = std::pair<int, std::vector<int>>;
std::vector<PairIntVector> x;
x.push_back(PairIntVector(3, {4}));
x.push_back({5, {6}});
}