Update re2

third_party/re2/util/sparse_array.h

 // Copyright 2006 The RE2 Authors.  All Rights Reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // DESCRIPTION
 // 
 // SparseArray<T>(m) is a map from integers in [0, m) to T values.
 // It requires (sizeof(T)+sizeof(int))*m memory, but it provides
 // fast iteration through the elements in the array and fast clearing
 // of the array.  The array has a concept of certain elements being
@@ skipping 202 matching lines @@
   // Since it doesn't set the value associated with i,
   // this function is private, only intended as a helper
   // for other methods.
   inline void create_index(int i);
 
   // In debug mode, verify that some invariant properties of the class
   // are being maintained. This is called at the end of the constructor
   // and at the beginning and end of all public non-const member functions.
   inline void DebugCheckInvariants() const;
 
+  static bool InitMemory() {
+#ifdef MEMORY_SANITIZER
+    return true;
+#else
+    return RunningOnValgrind();
+#endif
+  }
+
   int size_;
   int max_size_;
   int* sparse_to_dense_;
   vector<IndexValue> dense_;
-  bool valgrind_;
 
-  DISALLOW_EVIL_CONSTRUCTORS(SparseArray);
+  DISALLOW_COPY_AND_ASSIGN(SparseArray);
 };
 
 template<typename Value>
 SparseArray<Value>::SparseArray()
-    : size_(0), max_size_(0), sparse_to_dense_(NULL), dense_(),
-      valgrind_(RunningOnValgrindOrMemorySanitizer()) {}
+    : size_(0), max_size_(0), sparse_to_dense_(NULL), dense_() {}
 
 // IndexValue pairs: exposed in SparseArray::iterator.
 template<typename Value>
 class SparseArray<Value>::IndexValue {
   friend class SparseArray;
  public:
   typedef int first_type;
   typedef Value second_type;
 
   IndexValue() {}
@@ skipping 22 matching lines @@
 // Invalidates all iterators.
 template<typename Value>
 void SparseArray<Value>::resize(int new_max_size) {
   DebugCheckInvariants();
   if (new_max_size > max_size_) {
     int* a = new int[new_max_size];
     if (sparse_to_dense_) {
       memmove(a, sparse_to_dense_, max_size_*sizeof a[0]);
       delete[] sparse_to_dense_;
     }
-    // Don't need to zero the memory but appease Valgrind.
-    if (valgrind_) {
-      for (int i = max_size_; i < new_max_size; i++)
-        a[i] = 0xababababU;
-    }
     sparse_to_dense_ = a;
 
     dense_.resize(new_max_size);
+
+    // These don't need to be initialized for correctness,
+    // but Valgrind will warn about use of uninitialized memory,
+    // so initialize the new memory when compiling debug binaries.
+    // Initialize it to garbage to detect bugs in the future.
+    if (InitMemory()) {
+      for (int i = max_size_; i < new_max_size; i++) {
+        sparse_to_dense_[i] = 0xababababU;
+        dense_[i].index_ = 0xababababU;
+      }
+    }
   }
   max_size_ = new_max_size;
   if (size_ > max_size_)
     size_ = max_size_;
   DebugCheckInvariants();
 }
 
 // Check whether index i is in the array.
 template<typename Value>
 bool SparseArray<Value>::has_index(int i) const {
   DCHECK_GE(i, 0);
   DCHECK_LT(i, max_size_);
-  if (static_cast<uint>(i) >= max_size_) {
+  if (static_cast<uint>(i) >= static_cast<uint>(max_size_)) {
     return false;
   }
   // Unsigned comparison avoids checking sparse_to_dense_[i] < 0.
   return (uint)sparse_to_dense_[i] < (uint)size_ && 
     dense_[sparse_to_dense_[i]].index_ == i;
 }
 
 // Set the value at index i to v.
 template<typename Value>
 typename SparseArray<Value>::iterator SparseArray<Value>::set(int i, Value v) {
   DebugCheckInvariants();
-  if (static_cast<uint>(i) >= max_size_) {
+  if (static_cast<uint>(i) >= static_cast<uint>(max_size_)) {
     // Semantically, end() would be better here, but we already know
     // the user did something stupid, so begin() insulates them from
     // dereferencing an invalid pointer.
     return begin();
   }
   if (!has_index(i))
     create_index(i);
   return set_existing(i, v);
 }
 
@@ skipping 41 matching lines @@
   DCHECK(has_index(i));
   dense_[sparse_to_dense_[i]].second = v;
   DebugCheckInvariants();
   return dense_.begin() + sparse_to_dense_[i];
 }
 
 template<typename Value>
 typename SparseArray<Value>::iterator
 SparseArray<Value>::set_new(int i, Value v) {
   DebugCheckInvariants();
-  if (static_cast<uint>(i) >= max_size_) {
+  if (static_cast<uint>(i) >= static_cast<uint>(max_size_)) {
     // Semantically, end() would be better here, but we already know
     // the user did something stupid, so begin() insulates them from
     // dereferencing an invalid pointer.
     return begin();
   }
   DCHECK(!has_index(i));
   create_index(i);
   return set_existing(i, v);
 }
 
@@ skipping 29 matching lines @@
   DCHECK(!has_index(i));
   DCHECK_LT(size_, max_size_);
   sparse_to_dense_[i] = size_;
   dense_[size_].index_ = i;
   size_++;
 }
 
 template<typename Value> SparseArray<Value>::SparseArray(int max_size) {
   max_size_ = max_size;
   sparse_to_dense_ = new int[max_size];
-  valgrind_ = RunningOnValgrindOrMemorySanitizer();
   dense_.resize(max_size);
   // Don't need to zero the new memory, but appease Valgrind.
-  if (valgrind_) {
+  if (InitMemory()) {
     for (int i = 0; i < max_size; i++) {
       sparse_to_dense_[i] = 0xababababU;
       dense_[i].index_ = 0xababababU;
     }
   }
   size_ = 0;
   DebugCheckInvariants();
 }
 
 template<typename Value> SparseArray<Value>::~SparseArray() {
   DebugCheckInvariants();
   delete[] sparse_to_dense_;
 }
 
 template<typename Value> void SparseArray<Value>::DebugCheckInvariants() const {
   DCHECK_LE(0, size_);
   DCHECK_LE(size_, max_size_);
   DCHECK(size_ == 0 || sparse_to_dense_ != NULL);
 }
 
 // Comparison function for sorting.
 template<typename Value> bool SparseArray<Value>::less(const IndexValue& a,
                                                        const IndexValue& b) {
   return a.index_ < b.index_;
 }
 
 }  // namespace re2
 
 #endif  // RE2_UTIL_SPARSE_ARRAY_H__