1 //===- ASTVector.h - Vector that uses ASTContext for allocation --*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides ASTVector, a vector ADT whose contents are
11 // allocated using the allocator associated with an ASTContext..
13 //===----------------------------------------------------------------------===//
15 // FIXME: Most of this is copy-and-paste from BumpVector.h and SmallVector.h.
16 // We can refactor this core logic into something common.
18 #ifndef LLVM_CLANG_AST_VECTOR
19 #define LLVM_CLANG_AST_VECTOR
21 #include "clang/AST/AttrIterator.h"
22 #include "llvm/ADT/PointerIntPair.h"
23 #include "llvm/Support/Allocator.h"
24 #include "llvm/Support/type_traits.h"
36 llvm::PointerIntPair<T*, 1, bool> Capacity;
38 void setEnd(T *P) { this->End = P; }
41 // Make a tag bit available to users of this class.
42 // FIXME: This is a horrible hack.
43 bool getTag() const { return Capacity.getInt(); }
44 void setTag(bool B) { Capacity.setInt(B); }
47 // Default ctor - Initialize to empty.
48 ASTVector() : Begin(nullptr), End(nullptr), Capacity(nullptr, false) {}
50 ASTVector(ASTVector &&O) : Begin(O.Begin), End(O.End), Capacity(O.Capacity) {
51 O.Begin = O.End = nullptr;
52 O.Capacity.setPointer(nullptr);
53 O.Capacity.setInt(false);
56 ASTVector(const ASTContext &C, unsigned N)
57 : Begin(nullptr), End(nullptr), Capacity(nullptr, false) {
61 ASTVector &operator=(ASTVector &&RHS) {
62 ASTVector O(std::move(RHS));
66 swap(Capacity, O.Capacity);
71 if (std::is_class<T>::value) {
72 // Destroy the constructed elements in the vector.
73 destroy_range(Begin, End);
77 typedef size_t size_type;
78 typedef ptrdiff_t difference_type;
81 typedef const T* const_iterator;
83 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
84 typedef std::reverse_iterator<iterator> reverse_iterator;
87 typedef const T& const_reference;
89 typedef const T* const_pointer;
91 // forward iterator creation methods.
92 iterator begin() { return Begin; }
93 const_iterator begin() const { return Begin; }
94 iterator end() { return End; }
95 const_iterator end() const { return End; }
97 // reverse iterator creation methods.
98 reverse_iterator rbegin() { return reverse_iterator(end()); }
99 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
100 reverse_iterator rend() { return reverse_iterator(begin()); }
101 const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
103 bool empty() const { return Begin == End; }
104 size_type size() const { return End-Begin; }
106 reference operator[](unsigned idx) {
107 assert(Begin + idx < End);
110 const_reference operator[](unsigned idx) const {
111 assert(Begin + idx < End);
118 const_reference front() const {
125 const_reference back() const {
141 if (std::is_class<T>::value) {
142 destroy_range(Begin, End);
147 /// data - Return a pointer to the vector's buffer, even if empty().
149 return pointer(Begin);
152 /// data - Return a pointer to the vector's buffer, even if empty().
153 const_pointer data() const {
154 return const_pointer(Begin);
157 void push_back(const_reference Elt, const ASTContext &C) {
158 if (End < this->capacity_ptr()) {
168 void reserve(const ASTContext &C, unsigned N) {
169 if (unsigned(this->capacity_ptr()-Begin) < N)
173 /// capacity - Return the total number of elements in the currently allocated
175 size_t capacity() const { return this->capacity_ptr() - Begin; }
177 /// append - Add the specified range to the end of the SmallVector.
179 template<typename in_iter>
180 void append(const ASTContext &C, in_iter in_start, in_iter in_end) {
181 size_type NumInputs = std::distance(in_start, in_end);
186 // Grow allocated space if needed.
187 if (NumInputs > size_type(this->capacity_ptr()-this->end()))
188 this->grow(C, this->size()+NumInputs);
190 // Copy the new elements over.
191 // TODO: NEED To compile time dispatch on whether in_iter is a random access
192 // iterator to use the fast uninitialized_copy.
193 std::uninitialized_copy(in_start, in_end, this->end());
194 this->setEnd(this->end() + NumInputs);
197 /// append - Add the specified range to the end of the SmallVector.
199 void append(const ASTContext &C, size_type NumInputs, const T &Elt) {
200 // Grow allocated space if needed.
201 if (NumInputs > size_type(this->capacity_ptr()-this->end()))
202 this->grow(C, this->size()+NumInputs);
204 // Copy the new elements over.
205 std::uninitialized_fill_n(this->end(), NumInputs, Elt);
206 this->setEnd(this->end() + NumInputs);
209 /// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory
210 /// starting with "Dest", constructing elements into it as needed.
211 template<typename It1, typename It2>
212 static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
213 std::uninitialized_copy(I, E, Dest);
216 iterator insert(const ASTContext &C, iterator I, const T &Elt) {
217 if (I == this->end()) { // Important special case for empty vector.
219 return this->end()-1;
222 if (this->End < this->capacity_ptr()) {
224 new (this->end()) T(this->back());
225 this->setEnd(this->end()+1);
226 // Push everything else over.
227 std::copy_backward(I, this->end()-1, this->end());
231 size_t EltNo = I-this->begin();
233 I = this->begin()+EltNo;
237 iterator insert(const ASTContext &C, iterator I, size_type NumToInsert,
239 if (I == this->end()) { // Important special case for empty vector.
240 append(C, NumToInsert, Elt);
241 return this->end()-1;
244 // Convert iterator to elt# to avoid invalidating iterator when we reserve()
245 size_t InsertElt = I - this->begin();
247 // Ensure there is enough space.
248 reserve(C, static_cast<unsigned>(this->size() + NumToInsert));
250 // Uninvalidate the iterator.
251 I = this->begin()+InsertElt;
253 // If there are more elements between the insertion point and the end of the
254 // range than there are being inserted, we can use a simple approach to
255 // insertion. Since we already reserved space, we know that this won't
256 // reallocate the vector.
257 if (size_t(this->end()-I) >= NumToInsert) {
258 T *OldEnd = this->end();
259 append(C, this->end()-NumToInsert, this->end());
261 // Copy the existing elements that get replaced.
262 std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
264 std::fill_n(I, NumToInsert, Elt);
268 // Otherwise, we're inserting more elements than exist already, and we're
269 // not inserting at the end.
271 // Copy over the elements that we're about to overwrite.
272 T *OldEnd = this->end();
273 this->setEnd(this->end() + NumToInsert);
274 size_t NumOverwritten = OldEnd-I;
275 this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
277 // Replace the overwritten part.
278 std::fill_n(I, NumOverwritten, Elt);
280 // Insert the non-overwritten middle part.
281 std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
285 template<typename ItTy>
286 iterator insert(const ASTContext &C, iterator I, ItTy From, ItTy To) {
287 if (I == this->end()) { // Important special case for empty vector.
289 return this->end()-1;
292 size_t NumToInsert = std::distance(From, To);
293 // Convert iterator to elt# to avoid invalidating iterator when we reserve()
294 size_t InsertElt = I - this->begin();
296 // Ensure there is enough space.
297 reserve(C, static_cast<unsigned>(this->size() + NumToInsert));
299 // Uninvalidate the iterator.
300 I = this->begin()+InsertElt;
302 // If there are more elements between the insertion point and the end of the
303 // range than there are being inserted, we can use a simple approach to
304 // insertion. Since we already reserved space, we know that this won't
305 // reallocate the vector.
306 if (size_t(this->end()-I) >= NumToInsert) {
307 T *OldEnd = this->end();
308 append(C, this->end()-NumToInsert, this->end());
310 // Copy the existing elements that get replaced.
311 std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
313 std::copy(From, To, I);
317 // Otherwise, we're inserting more elements than exist already, and we're
318 // not inserting at the end.
320 // Copy over the elements that we're about to overwrite.
321 T *OldEnd = this->end();
322 this->setEnd(this->end() + NumToInsert);
323 size_t NumOverwritten = OldEnd-I;
324 this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
326 // Replace the overwritten part.
327 for (; NumOverwritten > 0; --NumOverwritten) {
332 // Insert the non-overwritten middle part.
333 this->uninitialized_copy(From, To, OldEnd);
337 void resize(const ASTContext &C, unsigned N, const T &NV) {
338 if (N < this->size()) {
339 this->destroy_range(this->begin()+N, this->end());
340 this->setEnd(this->begin()+N);
341 } else if (N > this->size()) {
342 if (this->capacity() < N)
344 construct_range(this->end(), this->begin()+N, NV);
345 this->setEnd(this->begin()+N);
350 /// grow - double the size of the allocated memory, guaranteeing space for at
351 /// least one more element or MinSize if specified.
352 void grow(const ASTContext &C, size_type MinSize = 1);
354 void construct_range(T *S, T *E, const T &Elt) {
359 void destroy_range(T *S, T *E) {
367 const_iterator capacity_ptr() const {
368 return (iterator) Capacity.getPointer();
370 iterator capacity_ptr() { return (iterator)Capacity.getPointer(); }
373 // Define this out-of-line to dissuade the C++ compiler from inlining it.
374 template <typename T>
375 void ASTVector<T>::grow(const ASTContext &C, size_t MinSize) {
376 size_t CurCapacity = this->capacity();
377 size_t CurSize = size();
378 size_t NewCapacity = 2*CurCapacity;
379 if (NewCapacity < MinSize)
380 NewCapacity = MinSize;
382 // Allocate the memory from the ASTContext.
383 T *NewElts = new (C, llvm::alignOf<T>()) T[NewCapacity];
385 // Copy the elements over.
386 if (std::is_class<T>::value) {
387 std::uninitialized_copy(Begin, End, NewElts);
388 // Destroy the original elements.
389 destroy_range(Begin, End);
392 // Use memcpy for PODs (std::uninitialized_copy optimizes to memmove).
393 memcpy(NewElts, Begin, CurSize * sizeof(T));
396 // ASTContext never frees any memory.
398 End = NewElts+CurSize;
399 Capacity.setPointer(Begin+NewCapacity);
402 } // end: clang namespace