/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/include/clang/Analysis/Analyses/ThreadSafetyUtil.h

Source (jump to first uncovered line)
//===- ThreadSafetyUtil.h ---------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines some basic utility classes for use by ThreadSafetyTIL.h
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H
#define LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H

#include "clang/AST/Decl.h"
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Support/Allocator.h"
#include <cassert>
#include <cstddef>
#include <cstring>
#include <iterator>
#include <ostream>
#include <string>
#include <vector>

namespace clang {

class Expr;

namespace threadSafety {
namespace til {

// Simple wrapper class to abstract away from the details of memory management.
// SExprs are allocated in pools, and deallocated all at once.
class MemRegionRef {
private:
  union AlignmentType {
    double d;
    void *p;
    long double dd;
    long long ii;
  };

public:
  MemRegionRef() = default;
  MemRegionRef(llvm::BumpPtrAllocator *A) : Allocator(A) {}

  void *allocate(size_t Sz) {
    return Allocator->Allocate(Sz, alignof(AlignmentType));
  }

  template <typename T> T *allocateT() { return Allocator->Allocate<T>(); }

  template <typename T> T *allocateT(size_t NumElems) {
    return Allocator->Allocate<T>(NumElems);
  }

private:
  llvm::BumpPtrAllocator *Allocator = nullptr;
};

} // namespace til
} // namespace threadSafety

} // namespace clang

inline void *operator new(size_t Sz,
                          clang::threadSafety::til::MemRegionRef &R) {
  return R.allocate(Sz);
}

namespace clang {
namespace threadSafety {

std::string getSourceLiteralString(const Expr *CE);

namespace til {

// A simple fixed size array class that does not manage its own memory,
// suitable for use with bump pointer allocation.
template <class T> class SimpleArray {
public:
  SimpleArray() = default;
  SimpleArray(T *Dat, size_t Cp, size_t Sz = 0)
      : Data(Dat), Size(Sz), Capacity(Cp) {}
  SimpleArray(MemRegionRef A, size_t Cp)
      : Data(Cp == 0 ? nullptr : A.allocateT<T>(Cp)), Capacity(Cp) {}
  SimpleArray(const SimpleArray<T> &A) = delete;

  SimpleArray(SimpleArray<T> &&A)
      : Data(A.Data), Size(A.Size), Capacity(A.Capacity) {
    A.Data = nullptr;
    A.Size = 0;
    A.Capacity = 0;
  }

  SimpleArray &operator=(SimpleArray &&RHS) {
    if (this != &RHS) {
      Data = RHS.Data;
      Size = RHS.Size;
      Capacity = RHS.Capacity;

      RHS.Data = nullptr;
      RHS.Size = RHS.Capacity = 0;
    }
    return *this;
  }

  // Reserve space for at least Ncp items, reallocating if necessary.
  void reserve(size_t Ncp, MemRegionRef A) {
    if (Ncp <= Capacity)
      return;
    T *Odata = Data;
    Data = A.allocateT<T>(Ncp);
    Capacity = Ncp;
    memcpy(Data, Odata, sizeof(T) * Size);
  }

  // Reserve space for at least N more items.
  void reserveCheck(size_t N, MemRegionRef A) {
    if (Capacity == 0)
      reserve(u_max(InitialCapacity, N), A);
    else if (Size + N < Capacity)
      reserve(u_max(Size + N, Capacity * 2), A);
  }

  using iterator = T *;
  using const_iterator = const T *;
  using reverse_iterator = std::reverse_iterator<iterator>;
  using const_reverse_iterator = std::reverse_iterator<const_iterator>;

  size_t size() const { return Size; }
  size_t capacity() const { return Capacity; }

  T &operator[](unsigned i) {
    assert(i < Size && "Array index out of bounds.");
    return Data[i];
  }

  const T &operator[](unsigned i) const {
    assert(i < Size && "Array index out of bounds.");
    return Data[i];
  }

  T &back() {
    assert(Size && "No elements in the array.");
    return Data[Size - 1];
  }

  const T &back() const {
    assert(Size && "No elements in the array.");
    return Data[Size - 1];
  }

  iterator begin() { return Data; }
  iterator end() { return Data + Size; }

  const_iterator begin() const { return Data; }
  const_iterator end() const { return Data + Size; }

  const_iterator cbegin() const { return Data; }
  const_iterator cend() const { return Data + Size; }

  reverse_iterator rbegin() { return reverse_iterator(end()); }
  reverse_iterator rend() { return reverse_iterator(begin()); }

  const_reverse_iterator rbegin() const {
    return const_reverse_iterator(end());
  }

  const_reverse_iterator rend() const {
    return const_reverse_iterator(begin());
  }

  void push_back(const T &Elem) {
    assert(Size < Capacity);
    Data[Size++] = Elem;
  }

  // drop last n elements from array
  void drop(unsigned n = 0) {
    assert(Size > n);
    Size -= n;
  }

  void setValues(unsigned Sz, const T& C) {
    assert(Sz <= Capacity);
    Size = Sz;
    for (unsigned i = 0; i < Sz; ++i) {
      Data[i] = C;
    }
  }

  template <class Iter> unsigned append(Iter I, Iter E) {
    size_t Osz = Size;
    size_t J = Osz;
    for (; J < Capacity && I != E; ++J, ++I)
      Data[J] = *I;
    Size = J;
    return J - Osz;
  }

  llvm::iterator_range<reverse_iterator> reverse() {
    return llvm::make_range(rbegin(), rend());
  }

  llvm::iterator_range<const_reverse_iterator> reverse() const {
    return llvm::make_range(rbegin(), rend());
  }

private:
  // std::max is annoying here, because it requires a reference,
  // thus forcing InitialCapacity to be initialized outside the .h file.
  size_t u_max(size_t i, size_t j) { return (i < j) ? j : i; }

  static const size_t InitialCapacity = 4;

  T *Data = nullptr;
  size_t Size = 0;
  size_t Capacity = 0;
};

}  // namespace til

// A copy on write vector.
// The vector can be in one of three states:
// * invalid -- no operations are permitted.
// * read-only -- read operations are permitted.
// * writable -- read and write operations are permitted.
// The init(), destroy(), and makeWritable() methods will change state.
template<typename T>
class CopyOnWriteVector {
  class VectorData {
  public:
    unsigned NumRefs = 1;
    std::vector<T> Vect;

    VectorData() = default;
    VectorData(const VectorData &VD) : Vect(VD.Vect) {}
  };

public:
  CopyOnWriteVector() = default;
  CopyOnWriteVector(CopyOnWriteVector &&V) : Data(V.Data) { V.Data = nullptr; }

  CopyOnWriteVector &operator=(CopyOnWriteVector &&V) {
    destroy();
    Data = V.Data;
    V.Data = nullptr;
    return *this;
  }

  // No copy constructor or copy assignment.  Use clone() with move assignment.
  CopyOnWriteVector(const CopyOnWriteVector &) = delete;
  CopyOnWriteVector &operator=(const CopyOnWriteVector &) = delete;

  ~CopyOnWriteVector() { destroy(); }

  // Returns true if this holds a valid vector.
  bool valid() const  { return Data; }

  // Returns true if this vector is writable.
  bool writable() const { return Data && Data->NumRefs == 1; }

  // If this vector is not valid, initialize it to a valid vector.
  void init() {
    if (!Data) {
      Data = new VectorData();
    }
  }

  // Destroy this vector; thus making it invalid.
  void destroy() {
    if (!Data)
      return;
    if (Data->NumRefs <= 1)
      delete Data;
    else
      --Data->NumRefs;
    Data = nullptr;
  }

  // Make this vector writable, creating a copy if needed.
  void makeWritable() {
    if (!Data) {
      Data = new VectorData();
      return;
    }
    if (Data->NumRefs == 1)
      return;   // already writeable.
    --Data->NumRefs;
    Data = new VectorData(*Data);
  }

  // Create a lazy copy of this vector.
  CopyOnWriteVector clone() { return CopyOnWriteVector(Data); }

  using const_iterator = typename std::vector<T>::const_iterator;

  const std::vector<T> &elements() const { return Data->Vect; }

  const_iterator begin() const { return elements().cbegin(); }
  const_iterator end() const { return elements().cend(); }

  const T& operator[](unsigned i) const { return elements()[i]; }

  unsigned size() const { return Data ? elements().size() : 0; }

  // Return true if V and this vector refer to the same data.
  bool sameAs(const CopyOnWriteVector &V) const { return Data == V.Data; }

  // Clear vector.  The vector must be writable.
  void clear() {
    assert(writable() && "Vector is not writable!");
    Data->Vect.clear();
  }

  // Push a new element onto the end.  The vector must be writable.
  void push_back(const T &Elem) {
    assert(writable() && "Vector is not writable!");
    Data->Vect.push_back(Elem);
  }

  // Gets a mutable reference to the element at index(i).
  // The vector must be writable.
  T& elem(unsigned i) {
    assert(writable() && "Vector is not writable!");
    return Data->Vect[i];
  }

  // Drops elements from the back until the vector has size i.
  void downsize(unsigned i) {
    assert(writable() && "Vector is not writable!");
    Data->Vect.erase(Data->Vect.begin() + i, Data->Vect.end());
  }

private:
  CopyOnWriteVector(VectorData *D) : Data(D) {
    if (!Data)
      return;
    ++Data->NumRefs;
  }

  VectorData *Data = nullptr;
};

inline std::ostream& operator<<(std::ostream& ss, const StringRef str) {
  return ss.write(str.data(), str.size());
}

} // namespace threadSafety
} // namespace clang

#endif // LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H

Coverage Report

Created: 2022-05-17 06:19

Line	Count	Source (jump to first uncovered line)
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	2.25k	MemRegionRef(llvm::BumpPtrAllocator *A) : Allocator(A) {}
50
51	21.2k	void *allocate(size_t Sz) {
52	21.2k	return Allocator->Allocate(Sz, alignof(AlignmentType));
53	21.2k	}
54
55		template <typename T> T *allocateT() { return Allocator->Allocate<T>(); }
56
57	0	template <typename T> T *allocateT(size_t NumElems) {
58	0	return Allocator->Allocate<T>(NumElems);
59	0	} Unexecuted instantiation: clang::threadSafety::til::SExpr** clang::threadSafety::til::MemRegionRef::allocateT<clang::threadSafety::til::SExpr>(unsigned long) Unexecuted instantiation: clang::threadSafety::til::BasicBlock* clang::threadSafety::til::MemRegionRef::allocateT<clang::threadSafety::til::BasicBlock*>(unsigned long)
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	21.2k	clang::threadSafety::til::MemRegionRef &R) {
72	21.2k	return R.allocate(Sz);
73	21.2k	}
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	0	SimpleArray() = default; Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::SimpleArray() Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::SimpleArray()
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	0	: Data(Cp == 0 ? nullptr : A.allocateT<T>(Cp)), Capacity(Cp) {} Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::SimpleArray(clang::threadSafety::til::MemRegionRef, unsigned long) Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::SimpleArray(clang::threadSafety::til::MemRegionRef, unsigned long)
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	0	void reserve(size_t Ncp, MemRegionRef A) {
114	0	if (Ncp <= Capacity)
115	0	return;
116	0	T *Odata = Data;
117	0	Data = A.allocateT<T>(Ncp);
118	0	Capacity = Ncp;
119	0	memcpy(Data, Odata, sizeof(T) * Size);
120	0	} Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::reserve(unsigned long, clang::threadSafety::til::MemRegionRef) Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::reserve(unsigned long, clang::threadSafety::til::MemRegionRef)
121
122		// Reserve space for at least N more items.
123	0	void reserveCheck(size_t N, MemRegionRef A) {
124	0	if (Capacity == 0)
125	0	reserve(u_max(InitialCapacity, N), A);
126	0	else if (Size + N < Capacity)
127	0	reserve(u_max(Size + N, Capacity * 2), A);
128	0	} Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::reserveCheck(unsigned long, clang::threadSafety::til::MemRegionRef) Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::reserveCheck(unsigned long, clang::threadSafety::til::MemRegionRef)
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	0	size_t size() const { return Size; } Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::size() const Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::size() const
136		size_t capacity() const { return Capacity; }
137
138	0	T &operator[](unsigned i) {
139	0	assert(i < Size && "Array index out of bounds.");
140	0	return Data[i];
141	0	} Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::operator[](unsigned int) Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::operator[](unsigned int)
142
143	0	const T &operator[](unsigned i) const {
144	0	assert(i < Size && "Array index out of bounds.");
145	0	return Data[i];
146	0	}
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	0	iterator begin() { return Data; } Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::begin() Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::begin()
159	0	iterator end() { return Data + Size; } Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::end() Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::end()
160
161	0	const_iterator begin() const { return Data; } Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::begin() const Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::begin() const
162	0	const_iterator end() const { return Data + Size; } Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::end() const Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::end() const
163
164	0	const_iterator cbegin() const { return Data; }
165	0	const_iterator cend() const { return Data + Size; }
166
167	0	reverse_iterator rbegin() { return reverse_iterator(end()); }
168	0	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	0	void push_back(const T &Elem) {
179	0	assert(Size < Capacity);
180	0	Data[Size++] = Elem;
181	0	} Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::push_back(clang::threadSafety::til::SExpr const&) Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::push_back(clang::threadSafety::til::BasicBlock const&)
182
183		// drop last n elements from array
184	0	void drop(unsigned n = 0) {
185	0	assert(Size > n);
186	0	Size -= n;
187	0	}
188
189	0	void setValues(unsigned Sz, const T& C) {
190	0	assert(Sz <= Capacity);
191	0	Size = Sz;
192	0	for (unsigned i = 0; i < Sz; ++i) {
193	0	Data[i] = C;
194	0	}
195	0	}
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	0	llvm::iterator_range<reverse_iterator> reverse() {
207	0	return llvm::make_range(rbegin(), rend());
208	0	}
209
210		llvm::iterator_range<const_reverse_iterator> reverse() const {
211		return llvm::make_range(rbegin(), rend());
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	0	size_t u_max(size_t i, size_t j) { return (i < j) ? j : i; } Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::SExpr>::u_max(unsigned long, unsigned long) Unexecuted instantiation: clang::threadSafety::til::SimpleArray<clang::threadSafety::til::BasicBlock>::u_max(unsigned long, unsigned long)
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	0	VectorData() = default;
242	0	VectorData(const VectorData &VD) : Vect(VD.Vect) {}
243		};
244
245		public:
246	2.25k	CopyOnWriteVector() = default;
247	0	CopyOnWriteVector(CopyOnWriteVector &&V) : Data(V.Data) { V.Data = nullptr; }
248
249	0	CopyOnWriteVector &operator=(CopyOnWriteVector &&V) {
250	0	destroy();
251	0	Data = V.Data;
252	0	V.Data = nullptr;
253	0	return *this;
254	0	}
255
256		// No copy constructor or copy assignment. Use clone() with move assignment.
257		CopyOnWriteVector(const CopyOnWriteVector &) = delete;
258		CopyOnWriteVector &operator=(const CopyOnWriteVector &) = delete;
259
260	2.25k	~CopyOnWriteVector() { destroy(); }
261
262		// Returns true if this holds a valid vector.
263	0	bool valid() const { return Data; }
264
265		// Returns true if this vector is writable.
266	0	bool writable() const { return Data && Data->NumRefs == 1; }
267
268		// If this vector is not valid, initialize it to a valid vector.
269		void init() {
270		if (!Data) {
271		Data = new VectorData();
272		}
273		}
274
275		// Destroy this vector; thus making it invalid.
276	2.25k	void destroy() {
277	2.25k	if (!Data)
278	2.25k	return;
279	0	if (Data->NumRefs <= 1)
280	0	delete Data;
281	0	else
282	0	--Data->NumRefs;
283	0	Data = nullptr;
284	0	}
285
286		// Make this vector writable, creating a copy if needed.
287	0	void makeWritable() {
288	0	if (!Data) {
289	0	Data = new VectorData();
290	0	return;
291	0	}
292	0	if (Data->NumRefs == 1)
293	0	return; // already writeable.
294	0	--Data->NumRefs;
295	0	Data = new VectorData(*Data);
296	0	}
297
298		// Create a lazy copy of this vector.
299	0	CopyOnWriteVector clone() { return CopyOnWriteVector(Data); }
300
301		using const_iterator = typename std::vector<T>::const_iterator;
302
303	0	const std::vector<T> &elements() const { return Data->Vect; }
304
305		const_iterator begin() const { return elements().cbegin(); }
306		const_iterator end() const { return elements().cend(); }
307
308	0	const T& operator[](unsigned i) const { return elements()[i]; }
309
310	0	unsigned size() const { return Data ? elements().size() : 0; }
311
312		// Return true if V and this vector refer to the same data.
313	0	bool sameAs(const CopyOnWriteVector &V) const { return Data == V.Data; }
314
315		// Clear vector. The vector must be writable.
316		void clear() {
317		assert(writable() && "Vector is not writable!");
318		Data->Vect.clear();
319		}
320
321		// Push a new element onto the end. The vector must be writable.
322	0	void push_back(const T &Elem) {
323	0	assert(writable() && "Vector is not writable!");
324	0	Data->Vect.push_back(Elem);
325	0	}
326
327		// Gets a mutable reference to the element at index(i).
328		// The vector must be writable.
329	0	T& elem(unsigned i) {
330	0	assert(writable() && "Vector is not writable!");
331	0	return Data->Vect[i];
332	0	}
333
334		// Drops elements from the back until the vector has size i.
335	0	void downsize(unsigned i) {
336	0	assert(writable() && "Vector is not writable!");
337	0	Data->Vect.erase(Data->Vect.begin() + i, Data->Vect.end());
338	0	}
339
340		private:
341	0	CopyOnWriteVector(VectorData *D) : Data(D) {
342	0	if (!Data)
343	0	return;
344	0	++Data->NumRefs;
345	0	}
346
347		VectorData *Data = nullptr;
348		};
349
350	2.78k	inline std::ostream& operator<<(std::ostream& ss, const StringRef str) {
351	2.78k	return ss.write(str.data(), str.size());
352	2.78k	}
353
354		} // namespace threadSafety
355		} // namespace clang
356
357		#endif // LLVM_CLANG_ANALYSIS_ANALYSES_THREADSAFETYUTIL_H