Line data Source code
1 : //===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===//
2 : //
3 : // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 : // See https://llvm.org/LICENSE.txt for license information.
5 : // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 : //
7 : //===----------------------------------------------------------------------===//
8 : ///
9 : /// \file
10 : /// This file defines the SmallVector class.
11 : ///
12 : //===----------------------------------------------------------------------===//
13 :
14 : #ifndef LLVM_ADT_SMALLVECTOR_H
15 : #define LLVM_ADT_SMALLVECTOR_H
16 :
17 : #include "llvm/Support/Compiler.h"
18 : #include "llvm/Support/type_traits.h"
19 : #include <algorithm>
20 : #include <cassert>
21 : #include <cstddef>
22 : #include <cstdint>
23 : #include <cstdlib>
24 : #include <cstring>
25 : #include <functional>
26 : #include <initializer_list>
27 : #include <iterator>
28 : #include <limits>
29 : #include <memory>
30 : #include <new>
31 : #include <type_traits>
32 : #include <utility>
33 :
34 : namespace llvm {
35 :
36 : template <typename T> class ArrayRef;
37 :
38 : template <typename IteratorT> class iterator_range;
39 :
40 : template <class Iterator>
41 : using EnableIfConvertibleToInputIterator = std::enable_if_t<std::is_convertible<
42 : typename std::iterator_traits<Iterator>::iterator_category,
43 : std::input_iterator_tag>::value>;
44 :
45 : /// This is all the stuff common to all SmallVectors.
46 : ///
47 : /// The template parameter specifies the type which should be used to hold the
48 : /// Size and Capacity of the SmallVector, so it can be adjusted.
49 : /// Using 32 bit size is desirable to shrink the size of the SmallVector.
50 : /// Using 64 bit size is desirable for cases like SmallVector<char>, where a
51 : /// 32 bit size would limit the vector to ~4GB. SmallVectors are used for
52 : /// buffering bitcode output - which can exceed 4GB.
53 : template <class Size_T> class SmallVectorBase {
54 : protected:
55 : void *BeginX;
56 : Size_T Size = 0, Capacity;
57 :
58 : /// The maximum value of the Size_T used.
59 : static constexpr size_t SizeTypeMax() {
60 : return std::numeric_limits<Size_T>::max();
61 : }
62 :
63 : SmallVectorBase() = delete;
64 : SmallVectorBase(void *FirstEl, size_t TotalCapacity)
65 : : BeginX(FirstEl), Capacity(static_cast<Size_T>(TotalCapacity)) {}
66 :
67 : /// This is a helper for \a grow() that's out of line to reduce code
68 : /// duplication. This function will report a fatal error if it can't grow at
69 : /// least to \p MinSize.
70 : void *mallocForGrow(void *FirstEl, size_t MinSize, size_t TSize,
71 : size_t &NewCapacity);
72 :
73 : /// This is an implementation of the grow() method which only works
74 : /// on POD-like data types and is out of line to reduce code duplication.
75 : /// This function will report a fatal error if it cannot increase capacity.
76 : void grow_pod(void *FirstEl, size_t MinSize, size_t TSize);
77 :
78 : /// If vector was first created with capacity 0, getFirstEl() points to the
79 : /// memory right after, an area unallocated. If a subsequent allocation,
80 : /// that grows the vector, happens to return the same pointer as getFirstEl(),
81 : /// get a new allocation, otherwise isSmall() will falsely return that no
82 : /// allocation was done (true) and the memory will not be freed in the
83 : /// destructor. If a VSize is given (vector size), also copy that many
84 : /// elements to the new allocation - used if realloca fails to increase
85 : /// space, and happens to allocate precisely at BeginX.
86 : /// This is unlikely to be called often, but resolves a memory leak when the
87 : /// situation does occur.
88 : void *replaceAllocation(void *NewElts, size_t TSize, size_t NewCapacity,
89 : size_t VSize = 0);
90 :
91 : public:
92 : size_t size() const { return Size; }
93 : size_t capacity() const { return Capacity; }
94 :
95 : [[nodiscard]] bool empty() const { return !Size; }
96 :
97 : protected:
98 : /// Set the array size to \p N, which the current array must have enough
99 : /// capacity for.
100 : ///
101 : /// This does not construct or destroy any elements in the vector.
102 : void set_size(size_t N) {
103 : assert(N <= capacity()); // implies no overflow in assignment
104 : Size = static_cast<Size_T>(N);
105 : }
106 :
107 : /// Set the array data pointer to \p Begin and capacity to \p N.
108 : ///
109 : /// This does not construct or destroy any elements in the vector.
110 : // This does not clean up any existing allocation.
111 : void set_allocation_range(void *Begin, size_t N) {
112 : assert(N <= SizeTypeMax());
113 : BeginX = Begin;
114 : Capacity = static_cast<Size_T>(N);
115 : }
116 : };
117 :
118 : template <class T>
119 : using SmallVectorSizeType =
120 : std::conditional_t<sizeof(T) < 4 && sizeof(void *) >= 8, uint64_t,
121 : uint32_t>;
122 :
123 : /// Figure out the offset of the first element.
124 : template <class T, typename = void> struct SmallVectorAlignmentAndSize {
125 : alignas(SmallVectorBase<SmallVectorSizeType<T>>) char Base[sizeof(
126 : SmallVectorBase<SmallVectorSizeType<T>>)];
127 : alignas(T) char FirstEl[sizeof(T)];
128 : };
129 :
130 : /// This is the part of SmallVectorTemplateBase which does not depend on whether
131 : /// the type T is a POD. The extra dummy template argument is used by ArrayRef
132 : /// to avoid unnecessarily requiring T to be complete.
133 : template <typename T, typename = void>
134 : class SmallVectorTemplateCommon
135 : : public SmallVectorBase<SmallVectorSizeType<T>> {
136 : using Base = SmallVectorBase<SmallVectorSizeType<T>>;
137 :
138 : protected:
139 : /// Find the address of the first element. For this pointer math to be valid
140 : /// with small-size of 0 for T with lots of alignment, it's important that
141 : /// SmallVectorStorage is properly-aligned even for small-size of 0.
142 624164 : void *getFirstEl() const {
143 : return const_cast<void *>(reinterpret_cast<const void *>(
144 : reinterpret_cast<const char *>(this) +
145 624164 : offsetof(SmallVectorAlignmentAndSize<T>, FirstEl)));
146 : }
147 : // Space after 'FirstEl' is clobbered, do not add any instance vars after it.
148 :
149 306646 : SmallVectorTemplateCommon(size_t Size) : Base(getFirstEl(), Size) {}
150 :
151 2286 : void grow_pod(size_t MinSize, size_t TSize) {
152 2286 : Base::grow_pod(getFirstEl(), MinSize, TSize);
153 2286 : }
154 :
155 : /// Return true if this is a smallvector which has not had dynamic
156 : /// memory allocated for it.
157 315232 : bool isSmall() const { return this->BeginX == getFirstEl(); }
158 :
159 : /// Put this vector in a state of being small.
160 0 : void resetToSmall() {
161 0 : this->BeginX = getFirstEl();
162 0 : this->Size = this->Capacity = 0; // FIXME: Setting Capacity to 0 is suspect.
163 0 : }
164 :
165 : /// Return true if V is an internal reference to the given range.
166 0 : bool isReferenceToRange(const void *V, const void *First, const void *Last) const {
167 : // Use std::less to avoid UB.
168 : std::less<> LessThan;
169 0 : return !LessThan(V, First) && LessThan(V, Last);
170 : }
171 :
172 : /// Return true if V is an internal reference to this vector.
173 0 : bool isReferenceToStorage(const void *V) const {
174 0 : return isReferenceToRange(V, this->begin(), this->end());
175 : }
176 :
177 : /// Return true if First and Last form a valid (possibly empty) range in this
178 : /// vector's storage.
179 : bool isRangeInStorage(const void *First, const void *Last) const {
180 : // Use std::less to avoid UB.
181 : std::less<> LessThan;
182 : return !LessThan(First, this->begin()) && !LessThan(Last, First) &&
183 : !LessThan(this->end(), Last);
184 : }
185 :
186 : /// Return true unless Elt will be invalidated by resizing the vector to
187 : /// NewSize.
188 : bool isSafeToReferenceAfterResize(const void *Elt, size_t NewSize) {
189 : // Past the end.
190 : if (LLVM_LIKELY(!isReferenceToStorage(Elt)))
191 : return true;
192 :
193 : // Return false if Elt will be destroyed by shrinking.
194 : if (NewSize <= this->size())
195 : return Elt < this->begin() + NewSize;
196 :
197 : // Return false if we need to grow.
198 : return NewSize <= this->capacity();
199 : }
200 :
201 : /// Check whether Elt will be invalidated by resizing the vector to NewSize.
202 : void assertSafeToReferenceAfterResize(const void *Elt, size_t NewSize) {
203 : assert(isSafeToReferenceAfterResize(Elt, NewSize) &&
204 : "Attempting to reference an element of the vector in an operation "
205 : "that invalidates it");
206 : }
207 :
208 : /// Check whether Elt will be invalidated by increasing the size of the
209 : /// vector by N.
210 : void assertSafeToAdd(const void *Elt, size_t N = 1) {
211 : this->assertSafeToReferenceAfterResize(Elt, this->size() + N);
212 : }
213 :
214 : /// Check whether any part of the range will be invalidated by clearing.
215 : void assertSafeToReferenceAfterClear(const T *From, const T *To) {
216 : if (From == To)
217 : return;
218 : this->assertSafeToReferenceAfterResize(From, 0);
219 : this->assertSafeToReferenceAfterResize(To - 1, 0);
220 : }
221 : template <
222 : class ItTy,
223 : std::enable_if_t<!std::is_same<std::remove_const_t<ItTy>, T *>::value,
224 : bool> = false>
225 : void assertSafeToReferenceAfterClear(ItTy, ItTy) {}
226 :
227 : /// Check whether any part of the range will be invalidated by growing.
228 : void assertSafeToAddRange(const T *From, const T *To) {
229 : if (From == To)
230 : return;
231 : this->assertSafeToAdd(From, To - From);
232 : this->assertSafeToAdd(To - 1, To - From);
233 : }
234 : template <
235 : class ItTy,
236 : std::enable_if_t<!std::is_same<std::remove_const_t<ItTy>, T *>::value,
237 : bool> = false>
238 : void assertSafeToAddRange(ItTy, ItTy) {}
239 :
240 : /// Reserve enough space to add one element, and return the updated element
241 : /// pointer in case it was a reference to the storage.
242 : template <class U>
243 711540 : static const T *reserveForParamAndGetAddressImpl(U *This, const T &Elt,
244 : size_t N) {
245 711540 : size_t NewSize = This->size() + N;
246 711540 : if (LLVM_LIKELY(NewSize <= This->capacity()))
247 709254 : return &Elt;
248 :
249 2286 : bool ReferencesStorage = false;
250 2286 : int64_t Index = -1;
251 : if (!U::TakesParamByValue) {
252 0 : if (LLVM_UNLIKELY(This->isReferenceToStorage(&Elt))) {
253 0 : ReferencesStorage = true;
254 0 : Index = &Elt - This->begin();
255 : }
256 : }
257 2286 : This->grow(NewSize);
258 2286 : return ReferencesStorage ? This->begin() + Index : &Elt;
259 : }
260 :
261 : public:
262 : using size_type = size_t;
263 : using difference_type = ptrdiff_t;
264 : using value_type = T;
265 : using iterator = T *;
266 : using const_iterator = const T *;
267 :
268 : using const_reverse_iterator = std::reverse_iterator<const_iterator>;
269 : using reverse_iterator = std::reverse_iterator<iterator>;
270 :
271 : using reference = T &;
272 : using const_reference = const T &;
273 : using pointer = T *;
274 : using const_pointer = const T *;
275 :
276 : using Base::capacity;
277 : using Base::empty;
278 : using Base::size;
279 :
280 : // forward iterator creation methods.
281 2093208 : iterator begin() { return (iterator)this->BeginX; }
282 20833 : const_iterator begin() const { return (const_iterator)this->BeginX; }
283 1749471 : iterator end() { return begin() + size(); }
284 9914 : const_iterator end() const { return begin() + size(); }
285 :
286 : // reverse iterator creation methods.
287 : reverse_iterator rbegin() { return reverse_iterator(end()); }
288 : const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
289 : reverse_iterator rend() { return reverse_iterator(begin()); }
290 : const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
291 :
292 : size_type size_in_bytes() const { return size() * sizeof(T); }
293 : size_type max_size() const {
294 : return std::min(this->SizeTypeMax(), size_type(-1) / sizeof(T));
295 : }
296 :
297 : size_t capacity_in_bytes() const { return capacity() * sizeof(T); }
298 :
299 : /// Return a pointer to the vector's buffer, even if empty().
300 : pointer data() { return pointer(begin()); }
301 : /// Return a pointer to the vector's buffer, even if empty().
302 1005 : const_pointer data() const { return const_pointer(begin()); }
303 :
304 : reference operator[](size_type idx) {
305 : assert(idx < size());
306 : return begin()[idx];
307 : }
308 : const_reference operator[](size_type idx) const {
309 : assert(idx < size());
310 : return begin()[idx];
311 : }
312 :
313 : reference front() {
314 : assert(!empty());
315 : return begin()[0];
316 : }
317 : const_reference front() const {
318 : assert(!empty());
319 : return begin()[0];
320 : }
321 :
322 704863 : reference back() {
323 704863 : assert(!empty());
324 704863 : return end()[-1];
325 : }
326 : const_reference back() const {
327 : assert(!empty());
328 : return end()[-1];
329 : }
330 : };
331 :
332 : /// SmallVectorTemplateBase<TriviallyCopyable = false> - This is where we put
333 : /// method implementations that are designed to work with non-trivial T's.
334 : ///
335 : /// We approximate is_trivially_copyable with trivial move/copy construction and
336 : /// trivial destruction. While the standard doesn't specify that you're allowed
337 : /// copy these types with memcpy, there is no way for the type to observe this.
338 : /// This catches the important case of std::pair<POD, POD>, which is not
339 : /// trivially assignable.
340 : template <typename T, bool = (std::is_trivially_copy_constructible<T>::value) &&
341 : (std::is_trivially_move_constructible<T>::value) &&
342 : std::is_trivially_destructible<T>::value>
343 : class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> {
344 : friend class SmallVectorTemplateCommon<T>;
345 :
346 : protected:
347 : static constexpr bool TakesParamByValue = false;
348 : using ValueParamT = const T &;
349 :
350 108 : SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
351 :
352 108 : static void destroy_range(T *S, T *E) {
353 108 : while (S != E) {
354 0 : --E;
355 0 : E->~T();
356 : }
357 108 : }
358 :
359 : /// Move the range [I, E) into the uninitialized memory starting with "Dest",
360 : /// constructing elements as needed.
361 : template<typename It1, typename It2>
362 0 : static void uninitialized_move(It1 I, It1 E, It2 Dest) {
363 0 : std::uninitialized_move(I, E, Dest);
364 0 : }
365 :
366 : /// Copy the range [I, E) onto the uninitialized memory starting with "Dest",
367 : /// constructing elements as needed.
368 : template<typename It1, typename It2>
369 : static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
370 : std::uninitialized_copy(I, E, Dest);
371 : }
372 :
373 : /// Grow the allocated memory (without initializing new elements), doubling
374 : /// the size of the allocated memory. Guarantees space for at least one more
375 : /// element, or MinSize more elements if specified.
376 : void grow(size_t MinSize = 0);
377 :
378 : /// Create a new allocation big enough for \p MinSize and pass back its size
379 : /// in \p NewCapacity. This is the first section of \a grow().
380 : T *mallocForGrow(size_t MinSize, size_t &NewCapacity);
381 :
382 : /// Move existing elements over to the new allocation \p NewElts, the middle
383 : /// section of \a grow().
384 : void moveElementsForGrow(T *NewElts);
385 :
386 : /// Transfer ownership of the allocation, finishing up \a grow().
387 : void takeAllocationForGrow(T *NewElts, size_t NewCapacity);
388 :
389 : /// Reserve enough space to add one element, and return the updated element
390 : /// pointer in case it was a reference to the storage.
391 664 : const T *reserveForParamAndGetAddress(const T &Elt, size_t N = 1) {
392 664 : return this->reserveForParamAndGetAddressImpl(this, Elt, N);
393 : }
394 :
395 : /// Reserve enough space to add one element, and return the updated element
396 : /// pointer in case it was a reference to the storage.
397 3961 : T *reserveForParamAndGetAddress(T &Elt, size_t N = 1) {
398 : return const_cast<T *>(
399 3961 : this->reserveForParamAndGetAddressImpl(this, Elt, N));
400 : }
401 :
402 : static T &&forward_value_param(T &&V) { return std::move(V); }
403 : static const T &forward_value_param(const T &V) { return V; }
404 :
405 : void growAndAssign(size_t NumElts, const T &Elt) {
406 : // Grow manually in case Elt is an internal reference.
407 : size_t NewCapacity;
408 : T *NewElts = mallocForGrow(NumElts, NewCapacity);
409 : std::uninitialized_fill_n(NewElts, NumElts, Elt);
410 : this->destroy_range(this->begin(), this->end());
411 : takeAllocationForGrow(NewElts, NewCapacity);
412 : this->set_size(NumElts);
413 : }
414 :
415 : template <typename... ArgTypes> T &growAndEmplaceBack(ArgTypes &&... Args) {
416 : // Grow manually in case one of Args is an internal reference.
417 : size_t NewCapacity;
418 : T *NewElts = mallocForGrow(0, NewCapacity);
419 : ::new ((void *)(NewElts + this->size())) T(std::forward<ArgTypes>(Args)...);
420 : moveElementsForGrow(NewElts);
421 : takeAllocationForGrow(NewElts, NewCapacity);
422 : this->set_size(this->size() + 1);
423 : return this->back();
424 : }
425 :
426 : public:
427 664 : void push_back(const T &Elt) {
428 664 : const T *EltPtr = reserveForParamAndGetAddress(Elt);
429 664 : ::new ((void *)this->end()) T(*EltPtr);
430 664 : this->set_size(this->size() + 1);
431 664 : }
432 :
433 3961 : void push_back(T &&Elt) {
434 3961 : T *EltPtr = reserveForParamAndGetAddress(Elt);
435 3961 : ::new ((void *)this->end()) T(::std::move(*EltPtr));
436 3961 : this->set_size(this->size() + 1);
437 3961 : }
438 :
439 4625 : void pop_back() {
440 4625 : this->set_size(this->size() - 1);
441 4625 : this->end()->~T();
442 4625 : }
443 : };
444 :
445 : // Define this out-of-line to dissuade the C++ compiler from inlining it.
446 : template <typename T, bool TriviallyCopyable>
447 0 : void SmallVectorTemplateBase<T, TriviallyCopyable>::grow(size_t MinSize) {
448 : size_t NewCapacity;
449 0 : T *NewElts = mallocForGrow(MinSize, NewCapacity);
450 0 : moveElementsForGrow(NewElts);
451 0 : takeAllocationForGrow(NewElts, NewCapacity);
452 0 : }
453 :
454 : template <typename T, bool TriviallyCopyable>
455 0 : T *SmallVectorTemplateBase<T, TriviallyCopyable>::mallocForGrow(
456 : size_t MinSize, size_t &NewCapacity) {
457 : return static_cast<T *>(
458 0 : SmallVectorBase<SmallVectorSizeType<T>>::mallocForGrow(
459 0 : this->getFirstEl(), MinSize, sizeof(T), NewCapacity));
460 : }
461 :
462 : // Define this out-of-line to dissuade the C++ compiler from inlining it.
463 : template <typename T, bool TriviallyCopyable>
464 0 : void SmallVectorTemplateBase<T, TriviallyCopyable>::moveElementsForGrow(
465 : T *NewElts) {
466 : // Move the elements over.
467 0 : this->uninitialized_move(this->begin(), this->end(), NewElts);
468 :
469 : // Destroy the original elements.
470 0 : destroy_range(this->begin(), this->end());
471 0 : }
472 :
473 : // Define this out-of-line to dissuade the C++ compiler from inlining it.
474 : template <typename T, bool TriviallyCopyable>
475 0 : void SmallVectorTemplateBase<T, TriviallyCopyable>::takeAllocationForGrow(
476 : T *NewElts, size_t NewCapacity) {
477 : // If this wasn't grown from the inline copy, deallocate the old space.
478 0 : if (!this->isSmall())
479 0 : free(this->begin());
480 :
481 0 : this->set_allocation_range(NewElts, NewCapacity);
482 0 : }
483 :
484 : /// SmallVectorTemplateBase<TriviallyCopyable = true> - This is where we put
485 : /// method implementations that are designed to work with trivially copyable
486 : /// T's. This allows using memcpy in place of copy/move construction and
487 : /// skipping destruction.
488 : template <typename T>
489 : class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> {
490 : friend class SmallVectorTemplateCommon<T>;
491 :
492 : protected:
493 : /// True if it's cheap enough to take parameters by value. Doing so avoids
494 : /// overhead related to mitigations for reference invalidation.
495 : static constexpr bool TakesParamByValue = sizeof(T) <= 2 * sizeof(void *);
496 :
497 : /// Either const T& or T, depending on whether it's cheap enough to take
498 : /// parameters by value.
499 : using ValueParamT = std::conditional_t<TakesParamByValue, T, const T &>;
500 :
501 306538 : SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
502 :
503 : // No need to do a destroy loop for POD's.
504 315124 : static void destroy_range(T *, T *) {}
505 :
506 : /// Move the range [I, E) onto the uninitialized memory
507 : /// starting with "Dest", constructing elements into it as needed.
508 : template<typename It1, typename It2>
509 8586 : static void uninitialized_move(It1 I, It1 E, It2 Dest) {
510 : // Just do a copy.
511 8586 : uninitialized_copy(I, E, Dest);
512 8586 : }
513 :
514 : /// Copy the range [I, E) onto the uninitialized memory
515 : /// starting with "Dest", constructing elements into it as needed.
516 : template<typename It1, typename It2>
517 : static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
518 : // Arbitrary iterator types; just use the basic implementation.
519 : std::uninitialized_copy(I, E, Dest);
520 : }
521 :
522 : /// Copy the range [I, E) onto the uninitialized memory
523 : /// starting with "Dest", constructing elements into it as needed.
524 : template <typename T1, typename T2>
525 13875 : static void uninitialized_copy(
526 : T1 *I, T1 *E, T2 *Dest,
527 : std::enable_if_t<std::is_same<std::remove_const_t<T1>, T2>::value> * =
528 : nullptr) {
529 : // Use memcpy for PODs iterated by pointers (which includes SmallVector
530 : // iterators): std::uninitialized_copy optimizes to memmove, but we can
531 : // use memcpy here. Note that I and E are iterators and thus might be
532 : // invalid for memcpy if they are equal.
533 13875 : if (I != E)
534 13875 : memcpy(reinterpret_cast<void *>(Dest), I, (E - I) * sizeof(T));
535 13875 : }
536 :
537 : /// Double the size of the allocated memory, guaranteeing space for at
538 : /// least one more element or MinSize if specified.
539 2286 : void grow(size_t MinSize = 0) { this->grow_pod(MinSize, sizeof(T)); }
540 :
541 : /// Reserve enough space to add one element, and return the updated element
542 : /// pointer in case it was a reference to the storage.
543 : const T *reserveForParamAndGetAddress(const T &Elt, size_t N = 1) {
544 : return this->reserveForParamAndGetAddressImpl(this, Elt, N);
545 : }
546 :
547 : /// Reserve enough space to add one element, and return the updated element
548 : /// pointer in case it was a reference to the storage.
549 706915 : T *reserveForParamAndGetAddress(T &Elt, size_t N = 1) {
550 : return const_cast<T *>(
551 706915 : this->reserveForParamAndGetAddressImpl(this, Elt, N));
552 : }
553 :
554 : /// Copy \p V or return a reference, depending on \a ValueParamT.
555 : static ValueParamT forward_value_param(ValueParamT V) { return V; }
556 :
557 : void growAndAssign(size_t NumElts, T Elt) {
558 : // Elt has been copied in case it's an internal reference, side-stepping
559 : // reference invalidation problems without losing the realloc optimization.
560 : this->set_size(0);
561 : this->grow(NumElts);
562 : std::uninitialized_fill_n(this->begin(), NumElts, Elt);
563 : this->set_size(NumElts);
564 : }
565 :
566 : template <typename... ArgTypes> T &growAndEmplaceBack(ArgTypes &&... Args) {
567 : // Use push_back with a copy in case Args has an internal reference,
568 : // side-stepping reference invalidation problems without losing the realloc
569 : // optimization.
570 : push_back(T(std::forward<ArgTypes>(Args)...));
571 : return this->back();
572 : }
573 :
574 : public:
575 706915 : void push_back(ValueParamT Elt) {
576 706915 : const T *EltPtr = reserveForParamAndGetAddress(Elt);
577 706915 : memcpy(reinterpret_cast<void *>(this->end()), EltPtr, sizeof(T));
578 706915 : this->set_size(this->size() + 1);
579 706915 : }
580 :
581 700238 : void pop_back() { this->set_size(this->size() - 1); }
582 : };
583 :
584 : /// This class consists of common code factored out of the SmallVector class to
585 : /// reduce code duplication based on the SmallVector 'N' template parameter.
586 : template <typename T>
587 : class SmallVectorImpl : public SmallVectorTemplateBase<T> {
588 : using SuperClass = SmallVectorTemplateBase<T>;
589 :
590 : public:
591 : using iterator = typename SuperClass::iterator;
592 : using const_iterator = typename SuperClass::const_iterator;
593 : using reference = typename SuperClass::reference;
594 : using size_type = typename SuperClass::size_type;
595 :
596 : protected:
597 : using SmallVectorTemplateBase<T>::TakesParamByValue;
598 : using ValueParamT = typename SuperClass::ValueParamT;
599 :
600 : // Default ctor - Initialize to empty.
601 306646 : explicit SmallVectorImpl(unsigned N)
602 306646 : : SmallVectorTemplateBase<T>(N) {}
603 :
604 0 : void assignRemote(SmallVectorImpl &&RHS) {
605 0 : this->destroy_range(this->begin(), this->end());
606 0 : if (!this->isSmall())
607 0 : free(this->begin());
608 0 : this->BeginX = RHS.BeginX;
609 0 : this->Size = RHS.Size;
610 0 : this->Capacity = RHS.Capacity;
611 0 : RHS.resetToSmall();
612 0 : }
613 :
614 306646 : ~SmallVectorImpl() {
615 : // Subclass has already destructed this vector's elements.
616 : // If this wasn't grown from the inline copy, deallocate the old space.
617 306646 : if (!this->isSmall())
618 1419 : free(this->begin());
619 306646 : }
620 :
621 : public:
622 : SmallVectorImpl(const SmallVectorImpl &) = delete;
623 :
624 8586 : void clear() {
625 8586 : this->destroy_range(this->begin(), this->end());
626 8586 : this->Size = 0;
627 8586 : }
628 :
629 : private:
630 : // Make set_size() private to avoid misuse in subclasses.
631 : using SuperClass::set_size;
632 :
633 : template <bool ForOverwrite> void resizeImpl(size_type N) {
634 : if (N == this->size())
635 : return;
636 :
637 : if (N < this->size()) {
638 : this->truncate(N);
639 : return;
640 : }
641 :
642 : this->reserve(N);
643 : for (auto I = this->end(), E = this->begin() + N; I != E; ++I)
644 : if (ForOverwrite)
645 : new (&*I) T;
646 : else
647 : new (&*I) T();
648 : this->set_size(N);
649 : }
650 :
651 : public:
652 : void resize(size_type N) { resizeImpl<false>(N); }
653 :
654 : /// Like resize, but \ref T is POD, the new values won't be initialized.
655 : void resize_for_overwrite(size_type N) { resizeImpl<true>(N); }
656 :
657 : /// Like resize, but requires that \p N is less than \a size().
658 : void truncate(size_type N) {
659 : assert(this->size() >= N && "Cannot increase size with truncate");
660 : this->destroy_range(this->begin() + N, this->end());
661 : this->set_size(N);
662 : }
663 :
664 : void resize(size_type N, ValueParamT NV) {
665 : if (N == this->size())
666 : return;
667 :
668 : if (N < this->size()) {
669 : this->truncate(N);
670 : return;
671 : }
672 :
673 : // N > this->size(). Defer to append.
674 : this->append(N - this->size(), NV);
675 : }
676 :
677 : void reserve(size_type N) {
678 : if (this->capacity() < N)
679 : this->grow(N);
680 : }
681 :
682 : void pop_back_n(size_type NumItems) {
683 : assert(this->size() >= NumItems);
684 : truncate(this->size() - NumItems);
685 : }
686 :
687 704863 : [[nodiscard]] T pop_back_val() {
688 704863 : T Result = ::std::move(this->back());
689 704863 : this->pop_back();
690 704863 : return Result;
691 0 : }
692 :
693 : void swap(SmallVectorImpl &RHS);
694 :
695 : /// Add the specified range to the end of the SmallVector.
696 : template <typename ItTy, typename = EnableIfConvertibleToInputIterator<ItTy>>
697 : void append(ItTy in_start, ItTy in_end) {
698 : this->assertSafeToAddRange(in_start, in_end);
699 : size_type NumInputs = std::distance(in_start, in_end);
700 : this->reserve(this->size() + NumInputs);
701 : this->uninitialized_copy(in_start, in_end, this->end());
702 : this->set_size(this->size() + NumInputs);
703 : }
704 :
705 : /// Append \p NumInputs copies of \p Elt to the end.
706 : void append(size_type NumInputs, ValueParamT Elt) {
707 : const T *EltPtr = this->reserveForParamAndGetAddress(Elt, NumInputs);
708 : std::uninitialized_fill_n(this->end(), NumInputs, *EltPtr);
709 : this->set_size(this->size() + NumInputs);
710 : }
711 :
712 : void append(std::initializer_list<T> IL) {
713 : append(IL.begin(), IL.end());
714 : }
715 :
716 : void append(const SmallVectorImpl &RHS) { append(RHS.begin(), RHS.end()); }
717 :
718 : void assign(size_type NumElts, ValueParamT Elt) {
719 : // Note that Elt could be an internal reference.
720 : if (NumElts > this->capacity()) {
721 : this->growAndAssign(NumElts, Elt);
722 : return;
723 : }
724 :
725 : // Assign over existing elements.
726 : std::fill_n(this->begin(), std::min(NumElts, this->size()), Elt);
727 : if (NumElts > this->size())
728 : std::uninitialized_fill_n(this->end(), NumElts - this->size(), Elt);
729 : else if (NumElts < this->size())
730 : this->destroy_range(this->begin() + NumElts, this->end());
731 : this->set_size(NumElts);
732 : }
733 :
734 : // FIXME: Consider assigning over existing elements, rather than clearing &
735 : // re-initializing them - for all assign(...) variants.
736 :
737 : template <typename ItTy, typename = EnableIfConvertibleToInputIterator<ItTy>>
738 : void assign(ItTy in_start, ItTy in_end) {
739 : this->assertSafeToReferenceAfterClear(in_start, in_end);
740 : clear();
741 : append(in_start, in_end);
742 : }
743 :
744 : void assign(std::initializer_list<T> IL) {
745 : clear();
746 : append(IL);
747 : }
748 :
749 : void assign(const SmallVectorImpl &RHS) { assign(RHS.begin(), RHS.end()); }
750 :
751 : iterator erase(const_iterator CI) {
752 : // Just cast away constness because this is a non-const member function.
753 : iterator I = const_cast<iterator>(CI);
754 :
755 : assert(this->isReferenceToStorage(CI) && "Iterator to erase is out of bounds.");
756 :
757 : iterator N = I;
758 : // Shift all elts down one.
759 : std::move(I+1, this->end(), I);
760 : // Drop the last elt.
761 : this->pop_back();
762 : return(N);
763 : }
764 :
765 : iterator erase(const_iterator CS, const_iterator CE) {
766 : // Just cast away constness because this is a non-const member function.
767 : iterator S = const_cast<iterator>(CS);
768 : iterator E = const_cast<iterator>(CE);
769 :
770 : assert(this->isRangeInStorage(S, E) && "Range to erase is out of bounds.");
771 :
772 : iterator N = S;
773 : // Shift all elts down.
774 : iterator I = std::move(E, this->end(), S);
775 : // Drop the last elts.
776 : this->destroy_range(I, this->end());
777 : this->set_size(I - this->begin());
778 : return(N);
779 : }
780 :
781 : private:
782 : template <class ArgType> iterator insert_one_impl(iterator I, ArgType &&Elt) {
783 : // Callers ensure that ArgType is derived from T.
784 : static_assert(
785 : std::is_same<std::remove_const_t<std::remove_reference_t<ArgType>>,
786 : T>::value,
787 : "ArgType must be derived from T!");
788 :
789 : if (I == this->end()) { // Important special case for empty vector.
790 : this->push_back(::std::forward<ArgType>(Elt));
791 : return this->end()-1;
792 : }
793 :
794 : assert(this->isReferenceToStorage(I) && "Insertion iterator is out of bounds.");
795 :
796 : // Grow if necessary.
797 : size_t Index = I - this->begin();
798 : std::remove_reference_t<ArgType> *EltPtr =
799 : this->reserveForParamAndGetAddress(Elt);
800 : I = this->begin() + Index;
801 :
802 : ::new ((void*) this->end()) T(::std::move(this->back()));
803 : // Push everything else over.
804 : std::move_backward(I, this->end()-1, this->end());
805 : this->set_size(this->size() + 1);
806 :
807 : // If we just moved the element we're inserting, be sure to update
808 : // the reference (never happens if TakesParamByValue).
809 : static_assert(!TakesParamByValue || std::is_same<ArgType, T>::value,
810 : "ArgType must be 'T' when taking by value!");
811 : if (!TakesParamByValue && this->isReferenceToRange(EltPtr, I, this->end()))
812 : ++EltPtr;
813 :
814 : *I = ::std::forward<ArgType>(*EltPtr);
815 : return I;
816 : }
817 :
818 : public:
819 : iterator insert(iterator I, T &&Elt) {
820 : return insert_one_impl(I, this->forward_value_param(std::move(Elt)));
821 : }
822 :
823 : iterator insert(iterator I, const T &Elt) {
824 : return insert_one_impl(I, this->forward_value_param(Elt));
825 : }
826 :
827 : iterator insert(iterator I, size_type NumToInsert, ValueParamT Elt) {
828 : // Convert iterator to elt# to avoid invalidating iterator when we reserve()
829 : size_t InsertElt = I - this->begin();
830 :
831 : if (I == this->end()) { // Important special case for empty vector.
832 : append(NumToInsert, Elt);
833 : return this->begin()+InsertElt;
834 : }
835 :
836 : assert(this->isReferenceToStorage(I) && "Insertion iterator is out of bounds.");
837 :
838 : // Ensure there is enough space, and get the (maybe updated) address of
839 : // Elt.
840 : const T *EltPtr = this->reserveForParamAndGetAddress(Elt, NumToInsert);
841 :
842 : // Uninvalidate the iterator.
843 : I = this->begin()+InsertElt;
844 :
845 : // If there are more elements between the insertion point and the end of the
846 : // range than there are being inserted, we can use a simple approach to
847 : // insertion. Since we already reserved space, we know that this won't
848 : // reallocate the vector.
849 : if (size_t(this->end()-I) >= NumToInsert) {
850 : T *OldEnd = this->end();
851 : append(std::move_iterator<iterator>(this->end() - NumToInsert),
852 : std::move_iterator<iterator>(this->end()));
853 :
854 : // Copy the existing elements that get replaced.
855 : std::move_backward(I, OldEnd-NumToInsert, OldEnd);
856 :
857 : // If we just moved the element we're inserting, be sure to update
858 : // the reference (never happens if TakesParamByValue).
859 : if (!TakesParamByValue && I <= EltPtr && EltPtr < this->end())
860 : EltPtr += NumToInsert;
861 :
862 : std::fill_n(I, NumToInsert, *EltPtr);
863 : return I;
864 : }
865 :
866 : // Otherwise, we're inserting more elements than exist already, and we're
867 : // not inserting at the end.
868 :
869 : // Move over the elements that we're about to overwrite.
870 : T *OldEnd = this->end();
871 : this->set_size(this->size() + NumToInsert);
872 : size_t NumOverwritten = OldEnd-I;
873 : this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
874 :
875 : // If we just moved the element we're inserting, be sure to update
876 : // the reference (never happens if TakesParamByValue).
877 : if (!TakesParamByValue && I <= EltPtr && EltPtr < this->end())
878 : EltPtr += NumToInsert;
879 :
880 : // Replace the overwritten part.
881 : std::fill_n(I, NumOverwritten, *EltPtr);
882 :
883 : // Insert the non-overwritten middle part.
884 : std::uninitialized_fill_n(OldEnd, NumToInsert - NumOverwritten, *EltPtr);
885 : return I;
886 : }
887 :
888 : template <typename ItTy, typename = EnableIfConvertibleToInputIterator<ItTy>>
889 : iterator insert(iterator I, ItTy From, ItTy To) {
890 : // Convert iterator to elt# to avoid invalidating iterator when we reserve()
891 : size_t InsertElt = I - this->begin();
892 :
893 : if (I == this->end()) { // Important special case for empty vector.
894 : append(From, To);
895 : return this->begin()+InsertElt;
896 : }
897 :
898 : assert(this->isReferenceToStorage(I) && "Insertion iterator is out of bounds.");
899 :
900 : // Check that the reserve that follows doesn't invalidate the iterators.
901 : this->assertSafeToAddRange(From, To);
902 :
903 : size_t NumToInsert = std::distance(From, To);
904 :
905 : // Ensure there is enough space.
906 : reserve(this->size() + NumToInsert);
907 :
908 : // Uninvalidate the iterator.
909 : I = this->begin()+InsertElt;
910 :
911 : // If there are more elements between the insertion point and the end of the
912 : // range than there are being inserted, we can use a simple approach to
913 : // insertion. Since we already reserved space, we know that this won't
914 : // reallocate the vector.
915 : if (size_t(this->end()-I) >= NumToInsert) {
916 : T *OldEnd = this->end();
917 : append(std::move_iterator<iterator>(this->end() - NumToInsert),
918 : std::move_iterator<iterator>(this->end()));
919 :
920 : // Copy the existing elements that get replaced.
921 : std::move_backward(I, OldEnd-NumToInsert, OldEnd);
922 :
923 : std::copy(From, To, I);
924 : return I;
925 : }
926 :
927 : // Otherwise, we're inserting more elements than exist already, and we're
928 : // not inserting at the end.
929 :
930 : // Move over the elements that we're about to overwrite.
931 : T *OldEnd = this->end();
932 : this->set_size(this->size() + NumToInsert);
933 : size_t NumOverwritten = OldEnd-I;
934 : this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
935 :
936 : // Replace the overwritten part.
937 : for (T *J = I; NumOverwritten > 0; --NumOverwritten) {
938 : *J = *From;
939 : ++J; ++From;
940 : }
941 :
942 : // Insert the non-overwritten middle part.
943 : this->uninitialized_copy(From, To, OldEnd);
944 : return I;
945 : }
946 :
947 : void insert(iterator I, std::initializer_list<T> IL) {
948 : insert(I, IL.begin(), IL.end());
949 : }
950 :
951 : template <typename... ArgTypes> reference emplace_back(ArgTypes &&... Args) {
952 : if (LLVM_UNLIKELY(this->size() >= this->capacity()))
953 : return this->growAndEmplaceBack(std::forward<ArgTypes>(Args)...);
954 :
955 : ::new ((void *)this->end()) T(std::forward<ArgTypes>(Args)...);
956 : this->set_size(this->size() + 1);
957 : return this->back();
958 : }
959 :
960 : SmallVectorImpl &operator=(const SmallVectorImpl &RHS);
961 :
962 : SmallVectorImpl &operator=(SmallVectorImpl &&RHS);
963 :
964 : bool operator==(const SmallVectorImpl &RHS) const {
965 : if (this->size() != RHS.size()) return false;
966 : return std::equal(this->begin(), this->end(), RHS.begin());
967 : }
968 : bool operator!=(const SmallVectorImpl &RHS) const {
969 : return !(*this == RHS);
970 : }
971 :
972 : bool operator<(const SmallVectorImpl &RHS) const {
973 : return std::lexicographical_compare(this->begin(), this->end(),
974 : RHS.begin(), RHS.end());
975 : }
976 : bool operator>(const SmallVectorImpl &RHS) const { return RHS < *this; }
977 : bool operator<=(const SmallVectorImpl &RHS) const { return !(*this > RHS); }
978 : bool operator>=(const SmallVectorImpl &RHS) const { return !(*this < RHS); }
979 : };
980 :
981 : template <typename T>
982 : void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) {
983 : if (this == &RHS) return;
984 :
985 : // We can only avoid copying elements if neither vector is small.
986 : if (!this->isSmall() && !RHS.isSmall()) {
987 : std::swap(this->BeginX, RHS.BeginX);
988 : std::swap(this->Size, RHS.Size);
989 : std::swap(this->Capacity, RHS.Capacity);
990 : return;
991 : }
992 : this->reserve(RHS.size());
993 : RHS.reserve(this->size());
994 :
995 : // Swap the shared elements.
996 : size_t NumShared = this->size();
997 : if (NumShared > RHS.size()) NumShared = RHS.size();
998 : for (size_type i = 0; i != NumShared; ++i)
999 : std::swap((*this)[i], RHS[i]);
1000 :
1001 : // Copy over the extra elts.
1002 : if (this->size() > RHS.size()) {
1003 : size_t EltDiff = this->size() - RHS.size();
1004 : this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end());
1005 : RHS.set_size(RHS.size() + EltDiff);
1006 : this->destroy_range(this->begin()+NumShared, this->end());
1007 : this->set_size(NumShared);
1008 : } else if (RHS.size() > this->size()) {
1009 : size_t EltDiff = RHS.size() - this->size();
1010 : this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end());
1011 : this->set_size(this->size() + EltDiff);
1012 : this->destroy_range(RHS.begin()+NumShared, RHS.end());
1013 : RHS.set_size(NumShared);
1014 : }
1015 : }
1016 :
1017 : template <typename T>
1018 5289 : SmallVectorImpl<T> &SmallVectorImpl<T>::
1019 : operator=(const SmallVectorImpl<T> &RHS) {
1020 : // Avoid self-assignment.
1021 5289 : if (this == &RHS) return *this;
1022 :
1023 : // If we already have sufficient space, assign the common elements, then
1024 : // destroy any excess.
1025 5289 : size_t RHSSize = RHS.size();
1026 5289 : size_t CurSize = this->size();
1027 5289 : if (CurSize >= RHSSize) {
1028 : // Assign common elements.
1029 : iterator NewEnd;
1030 0 : if (RHSSize)
1031 0 : NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin());
1032 : else
1033 0 : NewEnd = this->begin();
1034 :
1035 : // Destroy excess elements.
1036 0 : this->destroy_range(NewEnd, this->end());
1037 :
1038 : // Trim.
1039 0 : this->set_size(RHSSize);
1040 0 : return *this;
1041 : }
1042 :
1043 : // If we have to grow to have enough elements, destroy the current elements.
1044 : // This allows us to avoid copying them during the grow.
1045 : // FIXME: don't do this if they're efficiently moveable.
1046 5289 : if (this->capacity() < RHSSize) {
1047 : // Destroy current elements.
1048 0 : this->clear();
1049 0 : CurSize = 0;
1050 0 : this->grow(RHSSize);
1051 5289 : } else if (CurSize) {
1052 : // Otherwise, use assignment for the already-constructed elements.
1053 0 : std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin());
1054 : }
1055 :
1056 : // Copy construct the new elements in place.
1057 5289 : this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(),
1058 5289 : this->begin()+CurSize);
1059 :
1060 : // Set end.
1061 5289 : this->set_size(RHSSize);
1062 5289 : return *this;
1063 : }
1064 :
1065 : template <typename T>
1066 8586 : SmallVectorImpl<T> &SmallVectorImpl<T>::operator=(SmallVectorImpl<T> &&RHS) {
1067 : // Avoid self-assignment.
1068 8586 : if (this == &RHS) return *this;
1069 :
1070 : // If the RHS isn't small, clear this vector and then steal its buffer.
1071 8586 : if (!RHS.isSmall()) {
1072 0 : this->assignRemote(std::move(RHS));
1073 0 : return *this;
1074 : }
1075 :
1076 : // If we already have sufficient space, assign the common elements, then
1077 : // destroy any excess.
1078 8586 : size_t RHSSize = RHS.size();
1079 8586 : size_t CurSize = this->size();
1080 8586 : if (CurSize >= RHSSize) {
1081 : // Assign common elements.
1082 0 : iterator NewEnd = this->begin();
1083 0 : if (RHSSize)
1084 0 : NewEnd = std::move(RHS.begin(), RHS.end(), NewEnd);
1085 :
1086 : // Destroy excess elements and trim the bounds.
1087 0 : this->destroy_range(NewEnd, this->end());
1088 0 : this->set_size(RHSSize);
1089 :
1090 : // Clear the RHS.
1091 0 : RHS.clear();
1092 :
1093 0 : return *this;
1094 : }
1095 :
1096 : // If we have to grow to have enough elements, destroy the current elements.
1097 : // This allows us to avoid copying them during the grow.
1098 : // FIXME: this may not actually make any sense if we can efficiently move
1099 : // elements.
1100 8586 : if (this->capacity() < RHSSize) {
1101 : // Destroy current elements.
1102 0 : this->clear();
1103 0 : CurSize = 0;
1104 0 : this->grow(RHSSize);
1105 8586 : } else if (CurSize) {
1106 : // Otherwise, use assignment for the already-constructed elements.
1107 0 : std::move(RHS.begin(), RHS.begin()+CurSize, this->begin());
1108 : }
1109 :
1110 : // Move-construct the new elements in place.
1111 8586 : this->uninitialized_move(RHS.begin()+CurSize, RHS.end(),
1112 8586 : this->begin()+CurSize);
1113 :
1114 : // Set end.
1115 8586 : this->set_size(RHSSize);
1116 :
1117 8586 : RHS.clear();
1118 8586 : return *this;
1119 : }
1120 :
1121 : /// Storage for the SmallVector elements. This is specialized for the N=0 case
1122 : /// to avoid allocating unnecessary storage.
1123 : template <typename T, unsigned N>
1124 : struct SmallVectorStorage {
1125 : alignas(T) char InlineElts[N * sizeof(T)];
1126 : };
1127 :
1128 : /// We need the storage to be properly aligned even for small-size of 0 so that
1129 : /// the pointer math in \a SmallVectorTemplateCommon::getFirstEl() is
1130 : /// well-defined.
1131 : template <typename T> struct alignas(T) SmallVectorStorage<T, 0> {};
1132 :
1133 : /// Forward declaration of SmallVector so that
1134 : /// calculateSmallVectorDefaultInlinedElements can reference
1135 : /// `sizeof(SmallVector<T, 0>)`.
1136 : template <typename T, unsigned N> class LLVM_GSL_OWNER SmallVector;
1137 :
1138 : /// Helper class for calculating the default number of inline elements for
1139 : /// `SmallVector<T>`.
1140 : ///
1141 : /// This should be migrated to a constexpr function when our minimum
1142 : /// compiler support is enough for multi-statement constexpr functions.
1143 : template <typename T> struct CalculateSmallVectorDefaultInlinedElements {
1144 : // Parameter controlling the default number of inlined elements
1145 : // for `SmallVector<T>`.
1146 : //
1147 : // The default number of inlined elements ensures that
1148 : // 1. There is at least one inlined element.
1149 : // 2. `sizeof(SmallVector<T>) <= kPreferredSmallVectorSizeof` unless
1150 : // it contradicts 1.
1151 : static constexpr size_t kPreferredSmallVectorSizeof = 64;
1152 :
1153 : // static_assert that sizeof(T) is not "too big".
1154 : //
1155 : // Because our policy guarantees at least one inlined element, it is possible
1156 : // for an arbitrarily large inlined element to allocate an arbitrarily large
1157 : // amount of inline storage. We generally consider it an antipattern for a
1158 : // SmallVector to allocate an excessive amount of inline storage, so we want
1159 : // to call attention to these cases and make sure that users are making an
1160 : // intentional decision if they request a lot of inline storage.
1161 : //
1162 : // We want this assertion to trigger in pathological cases, but otherwise
1163 : // not be too easy to hit. To accomplish that, the cutoff is actually somewhat
1164 : // larger than kPreferredSmallVectorSizeof (otherwise,
1165 : // `SmallVector<SmallVector<T>>` would be one easy way to trip it, and that
1166 : // pattern seems useful in practice).
1167 : //
1168 : // One wrinkle is that this assertion is in theory non-portable, since
1169 : // sizeof(T) is in general platform-dependent. However, we don't expect this
1170 : // to be much of an issue, because most LLVM development happens on 64-bit
1171 : // hosts, and therefore sizeof(T) is expected to *decrease* when compiled for
1172 : // 32-bit hosts, dodging the issue. The reverse situation, where development
1173 : // happens on a 32-bit host and then fails due to sizeof(T) *increasing* on a
1174 : // 64-bit host, is expected to be very rare.
1175 : static_assert(
1176 : sizeof(T) <= 256,
1177 : "You are trying to use a default number of inlined elements for "
1178 : "`SmallVector<T>` but `sizeof(T)` is really big! Please use an "
1179 : "explicit number of inlined elements with `SmallVector<T, N>` to make "
1180 : "sure you really want that much inline storage.");
1181 :
1182 : // Discount the size of the header itself when calculating the maximum inline
1183 : // bytes.
1184 : static constexpr size_t PreferredInlineBytes =
1185 : kPreferredSmallVectorSizeof - sizeof(SmallVector<T, 0>);
1186 : static constexpr size_t NumElementsThatFit = PreferredInlineBytes / sizeof(T);
1187 : static constexpr size_t value =
1188 : NumElementsThatFit == 0 ? 1 : NumElementsThatFit;
1189 : };
1190 :
1191 : /// This is a 'vector' (really, a variable-sized array), optimized
1192 : /// for the case when the array is small. It contains some number of elements
1193 : /// in-place, which allows it to avoid heap allocation when the actual number of
1194 : /// elements is below that threshold. This allows normal "small" cases to be
1195 : /// fast without losing generality for large inputs.
1196 : ///
1197 : /// \note
1198 : /// In the absence of a well-motivated choice for the number of inlined
1199 : /// elements \p N, it is recommended to use \c SmallVector<T> (that is,
1200 : /// omitting the \p N). This will choose a default number of inlined elements
1201 : /// reasonable for allocation on the stack (for example, trying to keep \c
1202 : /// sizeof(SmallVector<T>) around 64 bytes).
1203 : ///
1204 : /// \warning This does not attempt to be exception safe.
1205 : ///
1206 : /// \see https://llvm.org/docs/ProgrammersManual.html#llvm-adt-smallvector-h
1207 : template <typename T,
1208 : unsigned N = CalculateSmallVectorDefaultInlinedElements<T>::value>
1209 : class LLVM_GSL_OWNER SmallVector : public SmallVectorImpl<T>,
1210 : SmallVectorStorage<T, N> {
1211 : public:
1212 293435 : SmallVector() : SmallVectorImpl<T>(N) {}
1213 :
1214 306646 : ~SmallVector() {
1215 : // Destroy the constructed elements in the vector.
1216 306646 : this->destroy_range(this->begin(), this->end());
1217 306646 : }
1218 :
1219 : explicit SmallVector(size_t Size)
1220 : : SmallVectorImpl<T>(N) {
1221 : this->resize(Size);
1222 : }
1223 :
1224 : SmallVector(size_t Size, const T &Value)
1225 : : SmallVectorImpl<T>(N) {
1226 : this->assign(Size, Value);
1227 : }
1228 :
1229 : template <typename ItTy, typename = EnableIfConvertibleToInputIterator<ItTy>>
1230 : SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
1231 : this->append(S, E);
1232 : }
1233 :
1234 : template <typename RangeTy>
1235 : explicit SmallVector(const iterator_range<RangeTy> &R)
1236 : : SmallVectorImpl<T>(N) {
1237 : this->append(R.begin(), R.end());
1238 : }
1239 :
1240 : SmallVector(std::initializer_list<T> IL) : SmallVectorImpl<T>(N) {
1241 : this->append(IL);
1242 : }
1243 :
1244 : template <typename U,
1245 : typename = std::enable_if_t<std::is_convertible<U, T>::value>>
1246 : explicit SmallVector(ArrayRef<U> A) : SmallVectorImpl<T>(N) {
1247 : this->append(A.begin(), A.end());
1248 : }
1249 :
1250 4625 : SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(N) {
1251 4625 : if (!RHS.empty())
1252 4625 : SmallVectorImpl<T>::operator=(RHS);
1253 4625 : }
1254 :
1255 664 : SmallVector &operator=(const SmallVector &RHS) {
1256 664 : SmallVectorImpl<T>::operator=(RHS);
1257 664 : return *this;
1258 : }
1259 :
1260 8586 : SmallVector(SmallVector &&RHS) : SmallVectorImpl<T>(N) {
1261 8586 : if (!RHS.empty())
1262 8586 : SmallVectorImpl<T>::operator=(::std::move(RHS));
1263 8586 : }
1264 :
1265 : SmallVector(SmallVectorImpl<T> &&RHS) : SmallVectorImpl<T>(N) {
1266 : if (!RHS.empty())
1267 : SmallVectorImpl<T>::operator=(::std::move(RHS));
1268 : }
1269 :
1270 : SmallVector &operator=(SmallVector &&RHS) {
1271 : if (N) {
1272 : SmallVectorImpl<T>::operator=(::std::move(RHS));
1273 : return *this;
1274 : }
1275 : // SmallVectorImpl<T>::operator= does not leverage N==0. Optimize the
1276 : // case.
1277 : if (this == &RHS)
1278 : return *this;
1279 : if (RHS.empty()) {
1280 : this->destroy_range(this->begin(), this->end());
1281 : this->Size = 0;
1282 : } else {
1283 : this->assignRemote(std::move(RHS));
1284 : }
1285 : return *this;
1286 : }
1287 :
1288 : SmallVector &operator=(SmallVectorImpl<T> &&RHS) {
1289 : SmallVectorImpl<T>::operator=(::std::move(RHS));
1290 : return *this;
1291 : }
1292 :
1293 : SmallVector &operator=(std::initializer_list<T> IL) {
1294 : this->assign(IL);
1295 : return *this;
1296 : }
1297 : };
1298 :
1299 : template <typename T, unsigned N>
1300 : inline size_t capacity_in_bytes(const SmallVector<T, N> &X) {
1301 : return X.capacity_in_bytes();
1302 : }
1303 :
1304 : template <typename RangeType>
1305 : using ValueTypeFromRangeType =
1306 : std::remove_const_t<std::remove_reference_t<decltype(*std::begin(
1307 : std::declval<RangeType &>()))>>;
1308 :
1309 : /// Given a range of type R, iterate the entire range and return a
1310 : /// SmallVector with elements of the vector. This is useful, for example,
1311 : /// when you want to iterate a range and then sort the results.
1312 : template <unsigned Size, typename R>
1313 : SmallVector<ValueTypeFromRangeType<R>, Size> to_vector(R &&Range) {
1314 : return {std::begin(Range), std::end(Range)};
1315 : }
1316 : template <typename R>
1317 : SmallVector<ValueTypeFromRangeType<R>> to_vector(R &&Range) {
1318 : return {std::begin(Range), std::end(Range)};
1319 : }
1320 :
1321 : template <typename Out, unsigned Size, typename R>
1322 : SmallVector<Out, Size> to_vector_of(R &&Range) {
1323 : return {std::begin(Range), std::end(Range)};
1324 : }
1325 :
1326 : template <typename Out, typename R> SmallVector<Out> to_vector_of(R &&Range) {
1327 : return {std::begin(Range), std::end(Range)};
1328 : }
1329 :
1330 : // Explicit instantiations
1331 : extern template class llvm::SmallVectorBase<uint32_t>;
1332 : #if SIZE_MAX > UINT32_MAX
1333 : extern template class llvm::SmallVectorBase<uint64_t>;
1334 : #endif
1335 :
1336 : } // end namespace llvm
1337 :
1338 : namespace std {
1339 :
1340 : /// Implement std::swap in terms of SmallVector swap.
1341 : template<typename T>
1342 : inline void
1343 : swap(llvm::SmallVectorImpl<T> &LHS, llvm::SmallVectorImpl<T> &RHS) {
1344 : LHS.swap(RHS);
1345 : }
1346 :
1347 : /// Implement std::swap in terms of SmallVector swap.
1348 : template<typename T, unsigned N>
1349 : inline void
1350 : swap(llvm::SmallVector<T, N> &LHS, llvm::SmallVector<T, N> &RHS) {
1351 : LHS.swap(RHS);
1352 : }
1353 :
1354 : } // end namespace std
1355 :
1356 : #endif // LLVM_ADT_SMALLVECTOR_H
|
