clang  3.7.0
ThreadSafetyUtil.h
Go to the documentation of this file.
1 //===- ThreadSafetyUtil.h --------------------------------------*- 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 defines some basic utility classes for use by ThreadSafetyTIL.h
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H
15 #define LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H
16 
17 #include "clang/AST/ExprCXX.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/Support/AlignOf.h"
20 #include "llvm/Support/Allocator.h"
21 #include "llvm/Support/Compiler.h"
22 #include <cassert>
23 #include <cstddef>
24 #include <ostream>
25 #include <utility>
26 #include <vector>
27 
28 namespace clang {
29 namespace threadSafety {
30 namespace til {
31 
32 // Simple wrapper class to abstract away from the details of memory management.
33 // SExprs are allocated in pools, and deallocated all at once.
34 class MemRegionRef {
35 private:
36  union AlignmentType {
37  double d;
38  void *p;
39  long double dd;
40  long long ii;
41  };
42 
43 public:
44  MemRegionRef() : Allocator(nullptr) {}
45  MemRegionRef(llvm::BumpPtrAllocator *A) : Allocator(A) {}
46 
47  void *allocate(size_t Sz) {
48  return Allocator->Allocate(Sz, llvm::AlignOf<AlignmentType>::Alignment);
49  }
50 
51  template <typename T> T *allocateT() { return Allocator->Allocate<T>(); }
52 
53  template <typename T> T *allocateT(size_t NumElems) {
54  return Allocator->Allocate<T>(NumElems);
55  }
56 
57 private:
58  llvm::BumpPtrAllocator *Allocator;
59 };
60 
61 
62 } // end namespace til
63 } // end namespace threadSafety
64 } // end namespace clang
65 
66 
67 inline void *operator new(size_t Sz,
69  return R.allocate(Sz);
70 }
71 
72 
73 namespace clang {
74 namespace threadSafety {
75 
76 std::string getSourceLiteralString(const clang::Expr *CE);
77 
78 using llvm::StringRef;
80 
81 namespace til {
82 
83 
84 // A simple fixed size array class that does not manage its own memory,
85 // suitable for use with bump pointer allocation.
86 template <class T> class SimpleArray {
87 public:
88  SimpleArray() : Data(nullptr), Size(0), Capacity(0) {}
89  SimpleArray(T *Dat, size_t Cp, size_t Sz = 0)
90  : Data(Dat), Size(Sz), Capacity(Cp) {}
91  SimpleArray(MemRegionRef A, size_t Cp)
92  : Data(Cp == 0 ? nullptr : A.allocateT<T>(Cp)), Size(0), Capacity(Cp) {}
94  : Data(A.Data), Size(A.Size), Capacity(A.Capacity) {
95  A.Data = nullptr;
96  A.Size = 0;
97  A.Capacity = 0;
98  }
99 
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  return;
121  }
122 
123  // Reserve space for at least N more items.
124  void reserveCheck(size_t N, MemRegionRef A) {
125  if (Capacity == 0)
126  reserve(u_max(InitialCapacity, N), A);
127  else if (Size + N < Capacity)
128  reserve(u_max(Size + N, Capacity * 2), A);
129  }
130 
131  typedef T *iterator;
132  typedef const T *const_iterator;
133  typedef std::reverse_iterator<iterator> reverse_iterator;
134  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
135 
136  size_t size() const { return Size; }
137  size_t capacity() const { return Capacity; }
138 
139  T &operator[](unsigned i) {
140  assert(i < Size && "Array index out of bounds.");
141  return Data[i];
142  }
143  const T &operator[](unsigned i) const {
144  assert(i < Size && "Array index out of bounds.");
145  return Data[i];
146  }
147  T &back() {
148  assert(Size && "No elements in the array.");
149  return Data[Size - 1];
150  }
151  const T &back() const {
152  assert(Size && "No elements in the array.");
153  return Data[Size - 1];
154  }
155 
156  iterator begin() { return Data; }
157  iterator end() { return Data + Size; }
158 
159  const_iterator begin() const { return Data; }
160  const_iterator end() const { return Data + Size; }
161 
162  const_iterator cbegin() const { return Data; }
163  const_iterator cend() const { return Data + Size; }
164 
167 
169  return const_reverse_iterator(end());
170  }
172  return const_reverse_iterator(begin());
173  }
174 
175  void push_back(const T &Elem) {
176  assert(Size < Capacity);
177  Data[Size++] = Elem;
178  }
179 
180  // drop last n elements from array
181  void drop(unsigned n = 0) {
182  assert(Size > n);
183  Size -= n;
184  }
185 
186  void setValues(unsigned Sz, const T& C) {
187  assert(Sz <= Capacity);
188  Size = Sz;
189  for (unsigned i = 0; i < Sz; ++i) {
190  Data[i] = C;
191  }
192  }
193 
194  template <class Iter> unsigned append(Iter I, Iter E) {
195  size_t Osz = Size;
196  size_t J = Osz;
197  for (; J < Capacity && I != E; ++J, ++I)
198  Data[J] = *I;
199  Size = J;
200  return J - Osz;
201  }
202 
203  llvm::iterator_range<reverse_iterator> reverse() {
204  return llvm::make_range(rbegin(), rend());
205  }
206  llvm::iterator_range<const_reverse_iterator> reverse() const {
207  return llvm::make_range(rbegin(), rend());
208  }
209 
210 private:
211  // std::max is annoying here, because it requires a reference,
212  // thus forcing InitialCapacity to be initialized outside the .h file.
213  size_t u_max(size_t i, size_t j) { return (i < j) ? j : i; }
214 
215  static const size_t InitialCapacity = 4;
216 
217  SimpleArray(const SimpleArray<T> &A) = delete;
218 
219  T *Data;
220  size_t Size;
221  size_t Capacity;
222 };
223 
224 
225 } // end namespace til
226 
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>
236  class VectorData {
237  public:
238  VectorData() : NumRefs(1) { }
239  VectorData(const VectorData &VD) : NumRefs(1), Vect(VD.Vect) { }
240 
241  unsigned NumRefs;
242  std::vector<T> Vect;
243  };
244 
245  // No copy constructor or copy assignment. Use clone() with move assignment.
246  CopyOnWriteVector(const CopyOnWriteVector &V) = delete;
247  void operator=(const CopyOnWriteVector &V) = delete;
248 
249 public:
250  CopyOnWriteVector() : Data(nullptr) {}
251  CopyOnWriteVector(CopyOnWriteVector &&V) : Data(V.Data) { V.Data = nullptr; }
253 
254  // Returns true if this holds a valid vector.
255  bool valid() const { return Data; }
256 
257  // Returns true if this vector is writable.
258  bool writable() const { return Data && Data->NumRefs == 1; }
259 
260  // If this vector is not valid, initialize it to a valid vector.
261  void init() {
262  if (!Data) {
263  Data = new VectorData();
264  }
265  }
266 
267  // Destroy this vector; thus making it invalid.
268  void destroy() {
269  if (!Data)
270  return;
271  if (Data->NumRefs <= 1)
272  delete Data;
273  else
274  --Data->NumRefs;
275  Data = nullptr;
276  }
277 
278  // Make this vector writable, creating a copy if needed.
279  void makeWritable() {
280  if (!Data) {
281  Data = new VectorData();
282  return;
283  }
284  if (Data->NumRefs == 1)
285  return; // already writeable.
286  --Data->NumRefs;
287  Data = new VectorData(*Data);
288  }
289 
290  // Create a lazy copy of this vector.
292 
294  destroy();
295  Data = V.Data;
296  V.Data = nullptr;
297  return *this;
298  }
299 
300  typedef typename std::vector<T>::const_iterator const_iterator;
301 
302  const std::vector<T> &elements() const { return Data->Vect; }
303 
304  const_iterator begin() const { return elements().cbegin(); }
305  const_iterator end() const { return elements().cend(); }
306 
307  const T& operator[](unsigned i) const { return elements()[i]; }
308 
309  unsigned size() const { return Data ? elements().size() : 0; }
310 
311  // Return true if V and this vector refer to the same data.
312  bool sameAs(const CopyOnWriteVector &V) const { return Data == V.Data; }
313 
314  // Clear vector. The vector must be writable.
315  void clear() {
316  assert(writable() && "Vector is not writable!");
317  Data->Vect.clear();
318  }
319 
320  // Push a new element onto the end. The vector must be writable.
321  void push_back(const T &Elem) {
322  assert(writable() && "Vector is not writable!");
323  Data->Vect.push_back(Elem);
324  }
325 
326  // Gets a mutable reference to the element at index(i).
327  // The vector must be writable.
328  T& elem(unsigned i) {
329  assert(writable() && "Vector is not writable!");
330  return Data->Vect[i];
331  }
332 
333  // Drops elements from the back until the vector has size i.
334  void downsize(unsigned i) {
335  assert(writable() && "Vector is not writable!");
336  Data->Vect.erase(Data->Vect.begin() + i, Data->Vect.end());
337  }
338 
339 private:
340  CopyOnWriteVector(VectorData *D) : Data(D) {
341  if (!Data)
342  return;
343  ++Data->NumRefs;
344  }
345 
346  VectorData *Data;
347 };
348 
349 
350 inline std::ostream& operator<<(std::ostream& ss, const StringRef str) {
351  return ss.write(str.data(), str.size());
352 }
353 
354 
355 } // end namespace threadSafety
356 } // end namespace clang
357 
358 #endif // LLVM_CLANG_THREAD_SAFETY_UTIL_H
SimpleArray(T *Dat, size_t Cp, size_t Sz=0)
Defines the clang::Expr interface and subclasses for C++ expressions.
const T & operator[](unsigned i) const
std::vector< T >::const_iterator const_iterator
llvm::iterator_range< const_reverse_iterator > reverse() const
llvm::iterator_range< reverse_iterator > reverse()
std::reverse_iterator< const_iterator > const_reverse_iterator
std::reverse_iterator< iterator > reverse_iterator
Encodes a location in the source. The SourceManager can decode this to get at the full include stack...
const std::vector< T > & elements() const
std::ostream & operator<<(std::ostream &ss, const StringRef str)
CopyOnWriteVector & operator=(CopyOnWriteVector &&V)
bool sameAs(const CopyOnWriteVector &V) const
std::string getSourceLiteralString(const clang::Expr *CE)
void reserveCheck(size_t N, MemRegionRef A)
static __inline__ uint32_t volatile uint32_t * p
Definition: arm_acle.h:75
const_reverse_iterator rend() const
MemRegionRef(llvm::BumpPtrAllocator *A)
void setValues(unsigned Sz, const T &C)
void reserve(size_t Ncp, MemRegionRef A)
SimpleArray(MemRegionRef A, size_t Cp)
SimpleArray & operator=(SimpleArray &&RHS)
const_reverse_iterator rbegin() const
const T & operator[](unsigned i) const