1 //===- ASTVector.h - Vector that uses ASTContext for allocation --*- C++ -*-=// 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 // This file provides ASTVector, a vector ADT whose contents are 11 // allocated using the allocator associated with an ASTContext.. 12 // 13 //===----------------------------------------------------------------------===// 14 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. 17 18 #ifndef LLVM_CLANG_AST_VECTOR 19 #define LLVM_CLANG_AST_VECTOR 20 21 #include "llvm/Support/type_traits.h" 22 #include "llvm/Support/Allocator.h" 23 #include "llvm/ADT/PointerIntPair.h" 24 #include <algorithm> 25 #include <memory> 26 #include <cstring> 27 28 #ifdef _MSC_VER 29 namespace std { 30 #if _MSC_VER <= 1310 31 // Work around flawed VC++ implementation of std::uninitialized_copy. Define 32 // additional overloads so that elements with pointer types are recognized as 33 // scalars and not objects, causing bizarre type conversion errors. 34 template<class T1, class T2> 35 inline _Scalar_ptr_iterator_tag _Ptr_cat(T1 **, T2 **) { 36 _Scalar_ptr_iterator_tag _Cat; 37 return _Cat; 38 } 39 40 template<class T1, class T2> 41 inline _Scalar_ptr_iterator_tag _Ptr_cat(T1* const *, T2 **) { 42 _Scalar_ptr_iterator_tag _Cat; 43 return _Cat; 44 } 45 #else 46 // FIXME: It is not clear if the problem is fixed in VS 2005. What is clear 47 // is that the above hack won't work if it wasn't fixed. 48 #endif 49 } 50 #endif 51 52 namespace clang { 53 54 template<typename T> 55 class ASTVector { 56 T *Begin, *End, *Capacity; 57 58 void setEnd(T *P) { this->End = P; } 59 60 public: 61 // Default ctor - Initialize to empty. 62 explicit ASTVector(ASTContext &C, unsigned N = 0) 63 : Begin(NULL), End(NULL), Capacity(NULL) { 64 reserve(C, N); 65 } 66 67 ~ASTVector() { 68 if (llvm::is_class<T>::value) { 69 // Destroy the constructed elements in the vector. 70 destroy_range(Begin, End); 71 } 72 } 73 74 typedef size_t size_type; 75 typedef ptrdiff_t difference_type; 76 typedef T value_type; 77 typedef T* iterator; 78 typedef const T* const_iterator; 79 80 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 81 typedef std::reverse_iterator<iterator> reverse_iterator; 82 83 typedef T& reference; 84 typedef const T& const_reference; 85 typedef T* pointer; 86 typedef const T* const_pointer; 87 88 // forward iterator creation methods. 89 iterator begin() { return Begin; } 90 const_iterator begin() const { return Begin; } 91 iterator end() { return End; } 92 const_iterator end() const { return End; } 93 94 // reverse iterator creation methods. 95 reverse_iterator rbegin() { return reverse_iterator(end()); } 96 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); } 97 reverse_iterator rend() { return reverse_iterator(begin()); } 98 const_reverse_iterator rend() const { return const_reverse_iterator(begin());} 99 100 bool empty() const { return Begin == End; } 101 size_type size() const { return End-Begin; } 102 103 reference operator[](unsigned idx) { 104 assert(Begin + idx < End); 105 return Begin[idx]; 106 } 107 const_reference operator[](unsigned idx) const { 108 assert(Begin + idx < End); 109 return Begin[idx]; 110 } 111 112 reference front() { 113 return begin()[0]; 114 } 115 const_reference front() const { 116 return begin()[0]; 117 } 118 119 reference back() { 120 return end()[-1]; 121 } 122 const_reference back() const { 123 return end()[-1]; 124 } 125 126 void pop_back() { 127 --End; 128 End->~T(); 129 } 130 131 T pop_back_val() { 132 T Result = back(); 133 pop_back(); 134 return Result; 135 } 136 137 void clear() { 138 if (llvm::is_class<T>::value) { 139 destroy_range(Begin, End); 140 } 141 End = Begin; 142 } 143 144 /// data - Return a pointer to the vector's buffer, even if empty(). 145 pointer data() { 146 return pointer(Begin); 147 } 148 149 /// data - Return a pointer to the vector's buffer, even if empty(). 150 const_pointer data() const { 151 return const_pointer(Begin); 152 } 153 154 void push_back(const_reference Elt, ASTContext &C) { 155 if (End < Capacity) { 156 Retry: 157 new (End) T(Elt); 158 ++End; 159 return; 160 } 161 grow(C); 162 goto Retry; 163 } 164 165 void reserve(ASTContext &C, unsigned N) { 166 if (unsigned(Capacity-Begin) < N) 167 grow(C, N); 168 } 169 170 /// capacity - Return the total number of elements in the currently allocated 171 /// buffer. 172 size_t capacity() const { return Capacity - Begin; } 173 174 /// append - Add the specified range to the end of the SmallVector. 175 /// 176 template<typename in_iter> 177 void append(ASTContext &C, in_iter in_start, in_iter in_end) { 178 size_type NumInputs = std::distance(in_start, in_end); 179 180 if (NumInputs == 0) 181 return; 182 183 // Grow allocated space if needed. 184 if (NumInputs > size_type(this->capacity_ptr()-this->end())) 185 this->grow(C, this->size()+NumInputs); 186 187 // Copy the new elements over. 188 // TODO: NEED To compile time dispatch on whether in_iter is a random access 189 // iterator to use the fast uninitialized_copy. 190 std::uninitialized_copy(in_start, in_end, this->end()); 191 this->setEnd(this->end() + NumInputs); 192 } 193 194 /// append - Add the specified range to the end of the SmallVector. 195 /// 196 void append(ASTContext &C, size_type NumInputs, const T &Elt) { 197 // Grow allocated space if needed. 198 if (NumInputs > size_type(this->capacity_ptr()-this->end())) 199 this->grow(C, this->size()+NumInputs); 200 201 // Copy the new elements over. 202 std::uninitialized_fill_n(this->end(), NumInputs, Elt); 203 this->setEnd(this->end() + NumInputs); 204 } 205 206 /// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory 207 /// starting with "Dest", constructing elements into it as needed. 208 template<typename It1, typename It2> 209 static void uninitialized_copy(It1 I, It1 E, It2 Dest) { 210 std::uninitialized_copy(I, E, Dest); 211 } 212 213 iterator insert(ASTContext &C, iterator I, const T &Elt) { 214 if (I == this->end()) { // Important special case for empty vector. 215 push_back(Elt); 216 return this->end()-1; 217 } 218 219 if (this->EndX < this->CapacityX) { 220 Retry: 221 new (this->end()) T(this->back()); 222 this->setEnd(this->end()+1); 223 // Push everything else over. 224 std::copy_backward(I, this->end()-1, this->end()); 225 *I = Elt; 226 return I; 227 } 228 size_t EltNo = I-this->begin(); 229 this->grow(C); 230 I = this->begin()+EltNo; 231 goto Retry; 232 } 233 234 iterator insert(ASTContext &C, iterator I, size_type NumToInsert, 235 const T &Elt) { 236 if (I == this->end()) { // Important special case for empty vector. 237 append(C, NumToInsert, Elt); 238 return this->end()-1; 239 } 240 241 // Convert iterator to elt# to avoid invalidating iterator when we reserve() 242 size_t InsertElt = I - this->begin(); 243 244 // Ensure there is enough space. 245 reserve(C, static_cast<unsigned>(this->size() + NumToInsert)); 246 247 // Uninvalidate the iterator. 248 I = this->begin()+InsertElt; 249 250 // If there are more elements between the insertion point and the end of the 251 // range than there are being inserted, we can use a simple approach to 252 // insertion. Since we already reserved space, we know that this won't 253 // reallocate the vector. 254 if (size_t(this->end()-I) >= NumToInsert) { 255 T *OldEnd = this->end(); 256 append(C, this->end()-NumToInsert, this->end()); 257 258 // Copy the existing elements that get replaced. 259 std::copy_backward(I, OldEnd-NumToInsert, OldEnd); 260 261 std::fill_n(I, NumToInsert, Elt); 262 return I; 263 } 264 265 // Otherwise, we're inserting more elements than exist already, and we're 266 // not inserting at the end. 267 268 // Copy over the elements that we're about to overwrite. 269 T *OldEnd = this->end(); 270 this->setEnd(this->end() + NumToInsert); 271 size_t NumOverwritten = OldEnd-I; 272 this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten); 273 274 // Replace the overwritten part. 275 std::fill_n(I, NumOverwritten, Elt); 276 277 // Insert the non-overwritten middle part. 278 std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt); 279 return I; 280 } 281 282 template<typename ItTy> 283 iterator insert(ASTContext &C, iterator I, ItTy From, ItTy To) { 284 if (I == this->end()) { // Important special case for empty vector. 285 append(C, From, To); 286 return this->end()-1; 287 } 288 289 size_t NumToInsert = std::distance(From, To); 290 // Convert iterator to elt# to avoid invalidating iterator when we reserve() 291 size_t InsertElt = I - this->begin(); 292 293 // Ensure there is enough space. 294 reserve(C, static_cast<unsigned>(this->size() + NumToInsert)); 295 296 // Uninvalidate the iterator. 297 I = this->begin()+InsertElt; 298 299 // If there are more elements between the insertion point and the end of the 300 // range than there are being inserted, we can use a simple approach to 301 // insertion. Since we already reserved space, we know that this won't 302 // reallocate the vector. 303 if (size_t(this->end()-I) >= NumToInsert) { 304 T *OldEnd = this->end(); 305 append(C, this->end()-NumToInsert, this->end()); 306 307 // Copy the existing elements that get replaced. 308 std::copy_backward(I, OldEnd-NumToInsert, OldEnd); 309 310 std::copy(From, To, I); 311 return I; 312 } 313 314 // Otherwise, we're inserting more elements than exist already, and we're 315 // not inserting at the end. 316 317 // Copy over the elements that we're about to overwrite. 318 T *OldEnd = this->end(); 319 this->setEnd(this->end() + NumToInsert); 320 size_t NumOverwritten = OldEnd-I; 321 this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten); 322 323 // Replace the overwritten part. 324 for (; NumOverwritten > 0; --NumOverwritten) { 325 *I = *From; 326 ++I; ++From; 327 } 328 329 // Insert the non-overwritten middle part. 330 this->uninitialized_copy(From, To, OldEnd); 331 return I; 332 } 333 334 void resize(ASTContext &C, unsigned N, const T &NV) { 335 if (N < this->size()) { 336 this->destroy_range(this->begin()+N, this->end()); 337 this->setEnd(this->begin()+N); 338 } else if (N > this->size()) { 339 if (this->capacity() < N) 340 this->grow(C, N); 341 construct_range(this->end(), this->begin()+N, NV); 342 this->setEnd(this->begin()+N); 343 } 344 } 345 346 private: 347 /// grow - double the size of the allocated memory, guaranteeing space for at 348 /// least one more element or MinSize if specified. 349 void grow(ASTContext &C, size_type MinSize = 1); 350 351 void construct_range(T *S, T *E, const T &Elt) { 352 for (; S != E; ++S) 353 new (S) T(Elt); 354 } 355 356 void destroy_range(T *S, T *E) { 357 while (S != E) { 358 --E; 359 E->~T(); 360 } 361 } 362 363 protected: 364 iterator capacity_ptr() { return (iterator)this->Capacity; } 365 }; 366 367 // Define this out-of-line to dissuade the C++ compiler from inlining it. 368 template <typename T> 369 void ASTVector<T>::grow(ASTContext &C, size_t MinSize) { 370 size_t CurCapacity = Capacity-Begin; 371 size_t CurSize = size(); 372 size_t NewCapacity = 2*CurCapacity; 373 if (NewCapacity < MinSize) 374 NewCapacity = MinSize; 375 376 // Allocate the memory from the ASTContext. 377 T *NewElts = new (C) T[NewCapacity]; 378 379 // Copy the elements over. 380 if (llvm::is_class<T>::value) { 381 std::uninitialized_copy(Begin, End, NewElts); 382 // Destroy the original elements. 383 destroy_range(Begin, End); 384 } 385 else { 386 // Use memcpy for PODs (std::uninitialized_copy optimizes to memmove). 387 memcpy(NewElts, Begin, CurSize * sizeof(T)); 388 } 389 390 C.Deallocate(Begin); 391 Begin = NewElts; 392 End = NewElts+CurSize; 393 Capacity = Begin+NewCapacity; 394 } 395 396 } // end: clang namespace 397 #endif 398