1 | //===- ThreadSafetyUtil.h ---------------------------------------*- 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 | // This file defines some basic utility classes for use by ThreadSafetyTIL.h |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H |
14 | #define LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H |
15 | |
16 | #include "clang/AST/Decl.h" |
17 | #include "clang/Basic/LLVM.h" |
18 | #include "llvm/ADT/StringRef.h" |
19 | #include "llvm/ADT/iterator_range.h" |
20 | #include "llvm/Support/Allocator.h" |
21 | #include <cassert> |
22 | #include <cstddef> |
23 | #include <cstring> |
24 | #include <iterator> |
25 | #include <ostream> |
26 | #include <string> |
27 | #include <vector> |
28 | |
29 | namespace clang { |
30 | |
31 | class Expr; |
32 | |
33 | namespace threadSafety { |
34 | namespace til { |
35 | |
36 | // Simple wrapper class to abstract away from the details of memory management. |
37 | // SExprs are allocated in pools, and deallocated all at once. |
38 | class MemRegionRef { |
39 | private: |
40 | union AlignmentType { |
41 | double d; |
42 | void *p; |
43 | long double dd; |
44 | long long ii; |
45 | }; |
46 | |
47 | public: |
48 | MemRegionRef() = default; |
49 | MemRegionRef(llvm::BumpPtrAllocator *A) : Allocator(A) {} |
50 | |
51 | void *allocate(size_t Sz) { |
52 | return Allocator->Allocate(Size: Sz, Alignment: alignof(AlignmentType)); |
53 | } |
54 | |
55 | template <typename T> T *allocateT() { return Allocator->Allocate<T>(); } |
56 | |
57 | template <typename T> T *allocateT(size_t NumElems) { |
58 | return Allocator->Allocate<T>(NumElems); |
59 | } |
60 | |
61 | private: |
62 | llvm::BumpPtrAllocator *Allocator = nullptr; |
63 | }; |
64 | |
65 | } // namespace til |
66 | } // namespace threadSafety |
67 | |
68 | } // namespace clang |
69 | |
70 | inline void *operator new(size_t Sz, |
71 | clang::threadSafety::til::MemRegionRef &R) { |
72 | return R.allocate(Sz); |
73 | } |
74 | |
75 | namespace clang { |
76 | namespace threadSafety { |
77 | |
78 | std::string getSourceLiteralString(const Expr *CE); |
79 | |
80 | namespace til { |
81 | |
82 | // A simple fixed size array class that does not manage its own memory, |
83 | // suitable for use with bump pointer allocation. |
84 | template <class T> class SimpleArray { |
85 | public: |
86 | SimpleArray() = default; |
87 | SimpleArray(T *Dat, size_t Cp, size_t Sz = 0) |
88 | : Data(Dat), Size(Sz), Capacity(Cp) {} |
89 | SimpleArray(MemRegionRef A, size_t Cp) |
90 | : Data(Cp == 0 ? nullptr : A.allocateT<T>(Cp)), Capacity(Cp) {} |
91 | SimpleArray(const SimpleArray<T> &A) = delete; |
92 | |
93 | SimpleArray(SimpleArray<T> &&A) |
94 | : Data(A.Data), Size(A.Size), Capacity(A.Capacity) { |
95 | A.Data = nullptr; |
96 | A.Size = 0; |
97 | A.Capacity = 0; |
98 | } |
99 | |
100 | SimpleArray &operator=(SimpleArray &&RHS) { |
101 | if (this != &RHS) { |
102 | Data = RHS.Data; |
103 | Size = RHS.Size; |
104 | Capacity = RHS.Capacity; |
105 | |
106 | RHS.Data = nullptr; |
107 | RHS.Size = RHS.Capacity = 0; |
108 | } |
109 | return *this; |
110 | } |
111 | |
112 | // Reserve space for at least Ncp items, reallocating if necessary. |
113 | void reserve(size_t Ncp, MemRegionRef A) { |
114 | if (Ncp <= Capacity) |
115 | return; |
116 | T *Odata = Data; |
117 | Data = A.allocateT<T>(Ncp); |
118 | Capacity = Ncp; |
119 | memcpy(Data, Odata, sizeof(T) * Size); |
120 | } |
121 | |
122 | // Reserve space for at least N more items. |
123 | void reserveCheck(size_t N, MemRegionRef A) { |
124 | if (Capacity == 0) |
125 | reserve(Ncp: u_max(i: InitialCapacity, j: N), A); |
126 | else if (Size + N < Capacity) |
127 | reserve(Ncp: u_max(i: Size + N, j: Capacity * 2), A); |
128 | } |
129 | |
130 | using iterator = T *; |
131 | using const_iterator = const T *; |
132 | using reverse_iterator = std::reverse_iterator<iterator>; |
133 | using const_reverse_iterator = std::reverse_iterator<const_iterator>; |
134 | |
135 | size_t size() const { return Size; } |
136 | size_t capacity() const { return Capacity; } |
137 | |
138 | T &operator[](unsigned i) { |
139 | assert(i < Size && "Array index out of bounds." ); |
140 | return Data[i]; |
141 | } |
142 | |
143 | const T &operator[](unsigned i) const { |
144 | assert(i < Size && "Array index out of bounds." ); |
145 | return Data[i]; |
146 | } |
147 | |
148 | T &back() { |
149 | assert(Size && "No elements in the array." ); |
150 | return Data[Size - 1]; |
151 | } |
152 | |
153 | const T &back() const { |
154 | assert(Size && "No elements in the array." ); |
155 | return Data[Size - 1]; |
156 | } |
157 | |
158 | iterator begin() { return Data; } |
159 | iterator end() { return Data + Size; } |
160 | |
161 | const_iterator begin() const { return Data; } |
162 | const_iterator end() const { return Data + Size; } |
163 | |
164 | const_iterator cbegin() const { return Data; } |
165 | const_iterator cend() const { return Data + Size; } |
166 | |
167 | reverse_iterator rbegin() { return reverse_iterator(end()); } |
168 | reverse_iterator rend() { return reverse_iterator(begin()); } |
169 | |
170 | const_reverse_iterator rbegin() const { |
171 | return const_reverse_iterator(end()); |
172 | } |
173 | |
174 | const_reverse_iterator rend() const { |
175 | return const_reverse_iterator(begin()); |
176 | } |
177 | |
178 | void push_back(const T &Elem) { |
179 | assert(Size < Capacity); |
180 | Data[Size++] = Elem; |
181 | } |
182 | |
183 | // drop last n elements from array |
184 | void drop(unsigned n = 0) { |
185 | assert(Size > n); |
186 | Size -= n; |
187 | } |
188 | |
189 | void setValues(unsigned Sz, const T& C) { |
190 | assert(Sz <= Capacity); |
191 | Size = Sz; |
192 | for (unsigned i = 0; i < Sz; ++i) { |
193 | Data[i] = C; |
194 | } |
195 | } |
196 | |
197 | template <class Iter> unsigned append(Iter I, Iter E) { |
198 | size_t Osz = Size; |
199 | size_t J = Osz; |
200 | for (; J < Capacity && I != E; ++J, ++I) |
201 | Data[J] = *I; |
202 | Size = J; |
203 | return J - Osz; |
204 | } |
205 | |
206 | llvm::iterator_range<reverse_iterator> reverse() { |
207 | return llvm::reverse(*this); |
208 | } |
209 | |
210 | llvm::iterator_range<const_reverse_iterator> reverse() const { |
211 | return llvm::reverse(*this); |
212 | } |
213 | |
214 | private: |
215 | // std::max is annoying here, because it requires a reference, |
216 | // thus forcing InitialCapacity to be initialized outside the .h file. |
217 | size_t u_max(size_t i, size_t j) { return (i < j) ? j : i; } |
218 | |
219 | static const size_t InitialCapacity = 4; |
220 | |
221 | T *Data = nullptr; |
222 | size_t Size = 0; |
223 | size_t Capacity = 0; |
224 | }; |
225 | |
226 | } // namespace til |
227 | |
228 | // A copy on write vector. |
229 | // The vector can be in one of three states: |
230 | // * invalid -- no operations are permitted. |
231 | // * read-only -- read operations are permitted. |
232 | // * writable -- read and write operations are permitted. |
233 | // The init(), destroy(), and makeWritable() methods will change state. |
234 | template<typename T> |
235 | class CopyOnWriteVector { |
236 | class VectorData { |
237 | public: |
238 | unsigned NumRefs = 1; |
239 | std::vector<T> Vect; |
240 | |
241 | VectorData() = default; |
242 | VectorData(const VectorData &VD) : Vect(VD.Vect) {} |
243 | |
244 | // The copy assignment operator is defined as deleted pending further |
245 | // motivation. |
246 | VectorData &operator=(const VectorData &) = delete; |
247 | }; |
248 | |
249 | public: |
250 | CopyOnWriteVector() = default; |
251 | CopyOnWriteVector(CopyOnWriteVector &&V) : Data(V.Data) { V.Data = nullptr; } |
252 | |
253 | CopyOnWriteVector &operator=(CopyOnWriteVector &&V) { |
254 | destroy(); |
255 | Data = V.Data; |
256 | V.Data = nullptr; |
257 | return *this; |
258 | } |
259 | |
260 | // No copy constructor or copy assignment. Use clone() with move assignment. |
261 | CopyOnWriteVector(const CopyOnWriteVector &) = delete; |
262 | CopyOnWriteVector &operator=(const CopyOnWriteVector &) = delete; |
263 | |
264 | ~CopyOnWriteVector() { destroy(); } |
265 | |
266 | // Returns true if this holds a valid vector. |
267 | bool valid() const { return Data; } |
268 | |
269 | // Returns true if this vector is writable. |
270 | bool writable() const { return Data && Data->NumRefs == 1; } |
271 | |
272 | // If this vector is not valid, initialize it to a valid vector. |
273 | void init() { |
274 | if (!Data) { |
275 | Data = new VectorData(); |
276 | } |
277 | } |
278 | |
279 | // Destroy this vector; thus making it invalid. |
280 | void destroy() { |
281 | if (!Data) |
282 | return; |
283 | if (Data->NumRefs <= 1) |
284 | delete Data; |
285 | else |
286 | --Data->NumRefs; |
287 | Data = nullptr; |
288 | } |
289 | |
290 | // Make this vector writable, creating a copy if needed. |
291 | void makeWritable() { |
292 | if (!Data) { |
293 | Data = new VectorData(); |
294 | return; |
295 | } |
296 | if (Data->NumRefs == 1) |
297 | return; // already writeable. |
298 | --Data->NumRefs; |
299 | Data = new VectorData(*Data); |
300 | } |
301 | |
302 | // Create a lazy copy of this vector. |
303 | CopyOnWriteVector clone() { return CopyOnWriteVector(Data); } |
304 | |
305 | using const_iterator = typename std::vector<T>::const_iterator; |
306 | |
307 | const std::vector<T> &elements() const { return Data->Vect; } |
308 | |
309 | const_iterator begin() const { return elements().cbegin(); } |
310 | const_iterator end() const { return elements().cend(); } |
311 | |
312 | const T& operator[](unsigned i) const { return elements()[i]; } |
313 | |
314 | unsigned size() const { return Data ? elements().size() : 0; } |
315 | |
316 | // Return true if V and this vector refer to the same data. |
317 | bool sameAs(const CopyOnWriteVector &V) const { return Data == V.Data; } |
318 | |
319 | // Clear vector. The vector must be writable. |
320 | void clear() { |
321 | assert(writable() && "Vector is not writable!" ); |
322 | Data->Vect.clear(); |
323 | } |
324 | |
325 | // Push a new element onto the end. The vector must be writable. |
326 | void push_back(const T &Elem) { |
327 | assert(writable() && "Vector is not writable!" ); |
328 | Data->Vect.push_back(Elem); |
329 | } |
330 | |
331 | // Gets a mutable reference to the element at index(i). |
332 | // The vector must be writable. |
333 | T& elem(unsigned i) { |
334 | assert(writable() && "Vector is not writable!" ); |
335 | return Data->Vect[i]; |
336 | } |
337 | |
338 | // Drops elements from the back until the vector has size i. |
339 | void downsize(unsigned i) { |
340 | assert(writable() && "Vector is not writable!" ); |
341 | Data->Vect.erase(Data->Vect.begin() + i, Data->Vect.end()); |
342 | } |
343 | |
344 | private: |
345 | CopyOnWriteVector(VectorData *D) : Data(D) { |
346 | if (!Data) |
347 | return; |
348 | ++Data->NumRefs; |
349 | } |
350 | |
351 | VectorData *Data = nullptr; |
352 | }; |
353 | |
354 | inline std::ostream& operator<<(std::ostream& ss, const StringRef str) { |
355 | return ss.write(s: str.data(), n: str.size()); |
356 | } |
357 | |
358 | } // namespace threadSafety |
359 | } // namespace clang |
360 | |
361 | #endif // LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H |
362 | |