This file is indexed.

/usr/include/llvm-3.9/llvm/ADT/SmallPtrSet.h is in llvm-3.9-dev 1:3.9.1-19ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
//===- llvm/ADT/SmallPtrSet.h - 'Normally small' pointer set ----*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the SmallPtrSet class.  See the doxygen comment for
// SmallPtrSetImplBase for more details on the algorithm used.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_ADT_SMALLPTRSET_H
#define LLVM_ADT_SMALLPTRSET_H

#include "llvm/Support/Compiler.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/PointerLikeTypeTraits.h"
#include <cassert>
#include <cstddef>
#include <cstring>
#include <cstdlib>
#include <iterator>
#include <utility>

namespace llvm {

class SmallPtrSetIteratorImpl;

/// SmallPtrSetImplBase - This is the common code shared among all the
/// SmallPtrSet<>'s, which is almost everything.  SmallPtrSet has two modes, one
/// for small and one for large sets.
///
/// Small sets use an array of pointers allocated in the SmallPtrSet object,
/// which is treated as a simple array of pointers.  When a pointer is added to
/// the set, the array is scanned to see if the element already exists, if not
/// the element is 'pushed back' onto the array.  If we run out of space in the
/// array, we grow into the 'large set' case.  SmallSet should be used when the
/// sets are often small.  In this case, no memory allocation is used, and only
/// light-weight and cache-efficient scanning is used.
///
/// Large sets use a classic exponentially-probed hash table.  Empty buckets are
/// represented with an illegal pointer value (-1) to allow null pointers to be
/// inserted.  Tombstones are represented with another illegal pointer value
/// (-2), to allow deletion.  The hash table is resized when the table is 3/4 or
/// more.  When this happens, the table is doubled in size.
///
class SmallPtrSetImplBase {
  friend class SmallPtrSetIteratorImpl;

protected:
  /// SmallArray - Points to a fixed size set of buckets, used in 'small mode'.
  const void **SmallArray;
  /// CurArray - This is the current set of buckets.  If equal to SmallArray,
  /// then the set is in 'small mode'.
  const void **CurArray;
  /// CurArraySize - The allocated size of CurArray, always a power of two.
  unsigned CurArraySize;

  /// Number of elements in CurArray that contain a value or are a tombstone.
  /// If small, all these elements are at the beginning of CurArray and the rest
  /// is uninitialized.
  unsigned NumNonEmpty;
  /// Number of tombstones in CurArray.
  unsigned NumTombstones;

  // Helpers to copy and move construct a SmallPtrSet.
  SmallPtrSetImplBase(const void **SmallStorage,
                      const SmallPtrSetImplBase &that);
  SmallPtrSetImplBase(const void **SmallStorage, unsigned SmallSize,
                      SmallPtrSetImplBase &&that);
  explicit SmallPtrSetImplBase(const void **SmallStorage, unsigned SmallSize)
      : SmallArray(SmallStorage), CurArray(SmallStorage),
        CurArraySize(SmallSize), NumNonEmpty(0), NumTombstones(0) {
    assert(SmallSize && (SmallSize & (SmallSize-1)) == 0 &&
           "Initial size must be a power of two!");
  }
  ~SmallPtrSetImplBase() {
    if (!isSmall())
      free(CurArray);
  }

public:
  typedef unsigned size_type;
  bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const { return size() == 0; }
  size_type size() const { return NumNonEmpty - NumTombstones; }

  void clear() {
    // If the capacity of the array is huge, and the # elements used is small,
    // shrink the array.
    if (!isSmall()) {
      if (size() * 4 < CurArraySize && CurArraySize > 32)
        return shrink_and_clear();
      // Fill the array with empty markers.
      memset(CurArray, -1, CurArraySize * sizeof(void *));
    }

    NumNonEmpty = 0;
    NumTombstones = 0;
  }

protected:
  static void *getTombstoneMarker() { return reinterpret_cast<void*>(-2); }
  static void *getEmptyMarker() {
    // Note that -1 is chosen to make clear() efficiently implementable with
    // memset and because it's not a valid pointer value.
    return reinterpret_cast<void*>(-1);
  }

  const void **EndPointer() const {
    return isSmall() ? CurArray + NumNonEmpty : CurArray + CurArraySize;
  }

  /// insert_imp - This returns true if the pointer was new to the set, false if
  /// it was already in the set.  This is hidden from the client so that the
  /// derived class can check that the right type of pointer is passed in.
  std::pair<const void *const *, bool> insert_imp(const void *Ptr) {
    if (isSmall()) {
      // Check to see if it is already in the set.
      const void **LastTombstone = nullptr;
      for (const void **APtr = SmallArray, **E = SmallArray + NumNonEmpty;
           APtr != E; ++APtr) {
        const void *Value = *APtr;
        if (Value == Ptr)
          return std::make_pair(APtr, false);
        if (Value == getTombstoneMarker())
          LastTombstone = APtr;
      }

      // Did we find any tombstone marker?
      if (LastTombstone != nullptr) {
        *LastTombstone = Ptr;
        --NumTombstones;
        return std::make_pair(LastTombstone, true);
      }

      // Nope, there isn't.  If we stay small, just 'pushback' now.
      if (NumNonEmpty < CurArraySize) {
        SmallArray[NumNonEmpty++] = Ptr;
        return std::make_pair(SmallArray + (NumNonEmpty - 1), true);
      }
      // Otherwise, hit the big set case, which will call grow.
    }
    return insert_imp_big(Ptr);
  }

  /// erase_imp - If the set contains the specified pointer, remove it and
  /// return true, otherwise return false.  This is hidden from the client so
  /// that the derived class can check that the right type of pointer is passed
  /// in.
  bool erase_imp(const void * Ptr);

  bool count_imp(const void * Ptr) const {
    if (isSmall()) {
      // Linear search for the item.
      for (const void *const *APtr = SmallArray,
                      *const *E = SmallArray + NumNonEmpty; APtr != E; ++APtr)
        if (*APtr == Ptr)
          return true;
      return false;
    }

    // Big set case.
    return *FindBucketFor(Ptr) == Ptr;
  }

private:
  bool isSmall() const { return CurArray == SmallArray; }

  std::pair<const void *const *, bool> insert_imp_big(const void *Ptr);

  const void * const *FindBucketFor(const void *Ptr) const;
  void shrink_and_clear();

  /// Grow - Allocate a larger backing store for the buckets and move it over.
  void Grow(unsigned NewSize);

  void operator=(const SmallPtrSetImplBase &RHS) = delete;

protected:
  /// swap - Swaps the elements of two sets.
  /// Note: This method assumes that both sets have the same small size.
  void swap(SmallPtrSetImplBase &RHS);

  void CopyFrom(const SmallPtrSetImplBase &RHS);
  void MoveFrom(unsigned SmallSize, SmallPtrSetImplBase &&RHS);

private:
  /// Code shared by MoveFrom() and move constructor.
  void MoveHelper(unsigned SmallSize, SmallPtrSetImplBase &&RHS);
  /// Code shared by CopyFrom() and copy constructor.
  void CopyHelper(const SmallPtrSetImplBase &RHS);
};

/// SmallPtrSetIteratorImpl - This is the common base class shared between all
/// instances of SmallPtrSetIterator.
class SmallPtrSetIteratorImpl {
protected:
  const void *const *Bucket;
  const void *const *End;

public:
  explicit SmallPtrSetIteratorImpl(const void *const *BP, const void*const *E)
    : Bucket(BP), End(E) {
    AdvanceIfNotValid();
  }

  bool operator==(const SmallPtrSetIteratorImpl &RHS) const {
    return Bucket == RHS.Bucket;
  }
  bool operator!=(const SmallPtrSetIteratorImpl &RHS) const {
    return Bucket != RHS.Bucket;
  }

protected:
  /// AdvanceIfNotValid - If the current bucket isn't valid, advance to a bucket
  /// that is.   This is guaranteed to stop because the end() bucket is marked
  /// valid.
  void AdvanceIfNotValid() {
    assert(Bucket <= End);
    while (Bucket != End &&
           (*Bucket == SmallPtrSetImplBase::getEmptyMarker() ||
            *Bucket == SmallPtrSetImplBase::getTombstoneMarker()))
      ++Bucket;
  }
};

/// SmallPtrSetIterator - This implements a const_iterator for SmallPtrSet.
template<typename PtrTy>
class SmallPtrSetIterator : public SmallPtrSetIteratorImpl {
  typedef PointerLikeTypeTraits<PtrTy> PtrTraits;

public:
  typedef PtrTy                     value_type;
  typedef PtrTy                     reference;
  typedef PtrTy                     pointer;
  typedef std::ptrdiff_t            difference_type;
  typedef std::forward_iterator_tag iterator_category;

  explicit SmallPtrSetIterator(const void *const *BP, const void *const *E)
    : SmallPtrSetIteratorImpl(BP, E) {}

  // Most methods provided by baseclass.

  const PtrTy operator*() const {
    assert(Bucket < End);
    return PtrTraits::getFromVoidPointer(const_cast<void*>(*Bucket));
  }

  inline SmallPtrSetIterator& operator++() {          // Preincrement
    ++Bucket;
    AdvanceIfNotValid();
    return *this;
  }

  SmallPtrSetIterator operator++(int) {        // Postincrement
    SmallPtrSetIterator tmp = *this; ++*this; return tmp;
  }
};

/// RoundUpToPowerOfTwo - This is a helper template that rounds N up to the next
/// power of two (which means N itself if N is already a power of two).
template<unsigned N>
struct RoundUpToPowerOfTwo;

/// RoundUpToPowerOfTwoH - If N is not a power of two, increase it.  This is a
/// helper template used to implement RoundUpToPowerOfTwo.
template<unsigned N, bool isPowerTwo>
struct RoundUpToPowerOfTwoH {
  enum { Val = N };
};
template<unsigned N>
struct RoundUpToPowerOfTwoH<N, false> {
  enum {
    // We could just use NextVal = N+1, but this converges faster.  N|(N-1) sets
    // the right-most zero bits to one all at once, e.g. 0b0011000 -> 0b0011111.
    Val = RoundUpToPowerOfTwo<(N|(N-1)) + 1>::Val
  };
};

template<unsigned N>
struct RoundUpToPowerOfTwo {
  enum { Val = RoundUpToPowerOfTwoH<N, (N&(N-1)) == 0>::Val };
};

/// \brief A templated base class for \c SmallPtrSet which provides the
/// typesafe interface that is common across all small sizes.
///
/// This is particularly useful for passing around between interface boundaries
/// to avoid encoding a particular small size in the interface boundary.
template <typename PtrType>
class SmallPtrSetImpl : public SmallPtrSetImplBase {
  typedef PointerLikeTypeTraits<PtrType> PtrTraits;

  SmallPtrSetImpl(const SmallPtrSetImpl &) = delete;

protected:
  // Constructors that forward to the base.
  SmallPtrSetImpl(const void **SmallStorage, const SmallPtrSetImpl &that)
      : SmallPtrSetImplBase(SmallStorage, that) {}
  SmallPtrSetImpl(const void **SmallStorage, unsigned SmallSize,
                  SmallPtrSetImpl &&that)
      : SmallPtrSetImplBase(SmallStorage, SmallSize, std::move(that)) {}
  explicit SmallPtrSetImpl(const void **SmallStorage, unsigned SmallSize)
      : SmallPtrSetImplBase(SmallStorage, SmallSize) {}

public:
  typedef SmallPtrSetIterator<PtrType> iterator;
  typedef SmallPtrSetIterator<PtrType> const_iterator;

  /// Inserts Ptr if and only if there is no element in the container equal to
  /// Ptr. The bool component of the returned pair is true if and only if the
  /// insertion takes place, and the iterator component of the pair points to
  /// the element equal to Ptr.
  std::pair<iterator, bool> insert(PtrType Ptr) {
    auto p = insert_imp(PtrTraits::getAsVoidPointer(Ptr));
    return std::make_pair(iterator(p.first, EndPointer()), p.second);
  }

  /// erase - If the set contains the specified pointer, remove it and return
  /// true, otherwise return false.
  bool erase(PtrType Ptr) {
    return erase_imp(PtrTraits::getAsVoidPointer(Ptr));
  }

  /// count - Return 1 if the specified pointer is in the set, 0 otherwise.
  size_type count(PtrType Ptr) const {
    return count_imp(PtrTraits::getAsVoidPointer(Ptr)) ? 1 : 0;
  }

  template <typename IterT>
  void insert(IterT I, IterT E) {
    for (; I != E; ++I)
      insert(*I);
  }

  inline iterator begin() const {
    return iterator(CurArray, EndPointer());
  }
  inline iterator end() const {
    const void *const *End = EndPointer();
    return iterator(End, End);
  }
};

/// SmallPtrSet - This class implements a set which is optimized for holding
/// SmallSize or less elements.  This internally rounds up SmallSize to the next
/// power of two if it is not already a power of two.  See the comments above
/// SmallPtrSetImplBase for details of the algorithm.
template<class PtrType, unsigned SmallSize>
class SmallPtrSet : public SmallPtrSetImpl<PtrType> {
  // In small mode SmallPtrSet uses linear search for the elements, so it is
  // not a good idea to choose this value too high. You may consider using a
  // DenseSet<> instead if you expect many elements in the set.
  static_assert(SmallSize <= 32, "SmallSize should be small");

  typedef SmallPtrSetImpl<PtrType> BaseT;

  // Make sure that SmallSize is a power of two, round up if not.
  enum { SmallSizePowTwo = RoundUpToPowerOfTwo<SmallSize>::Val };
  /// SmallStorage - Fixed size storage used in 'small mode'.
  const void *SmallStorage[SmallSizePowTwo];

public:
  SmallPtrSet() : BaseT(SmallStorage, SmallSizePowTwo) {}
  SmallPtrSet(const SmallPtrSet &that) : BaseT(SmallStorage, that) {}
  SmallPtrSet(SmallPtrSet &&that)
      : BaseT(SmallStorage, SmallSizePowTwo, std::move(that)) {}

  template<typename It>
  SmallPtrSet(It I, It E) : BaseT(SmallStorage, SmallSizePowTwo) {
    this->insert(I, E);
  }

  SmallPtrSet<PtrType, SmallSize> &
  operator=(const SmallPtrSet<PtrType, SmallSize> &RHS) {
    if (&RHS != this)
      this->CopyFrom(RHS);
    return *this;
  }

  SmallPtrSet<PtrType, SmallSize>&
  operator=(SmallPtrSet<PtrType, SmallSize> &&RHS) {
    if (&RHS != this)
      this->MoveFrom(SmallSizePowTwo, std::move(RHS));
    return *this;
  }

  /// swap - Swaps the elements of two sets.
  void swap(SmallPtrSet<PtrType, SmallSize> &RHS) {
    SmallPtrSetImplBase::swap(RHS);
  }
};
}

namespace std {
  /// Implement std::swap in terms of SmallPtrSet swap.
  template<class T, unsigned N>
  inline void swap(llvm::SmallPtrSet<T, N> &LHS, llvm::SmallPtrSet<T, N> &RHS) {
    LHS.swap(RHS);
  }
}

#endif