vendor/llvm/llvm-r114020

1 files changed, 31 insertions, 1 deletions

diff --git a/include/llvm/ADT/SmallVector.h b/include/llvm/ADT/SmallVector.h
index fa61d207bd305..1d6181a95da36 100644
--- a/include/llvm/ADT/SmallVector.h
+++ b/include/llvm/ADT/SmallVector.h
@@ -206,7 +206,7 @@ template <typename T, bool isPodLike>
 void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
   size_t CurCapacity = this->capacity();
   size_t CurSize = this->size();
-  size_t NewCapacity = 2*CurCapacity;
+  size_t NewCapacity = 2*CurCapacity + 1; // Always grow, even from zero.
   if (NewCapacity < MinSize)
     NewCapacity = MinSize;
   T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
@@ -707,6 +707,36 @@ public:
 
 };
 
+/// Specialize SmallVector at N=0.  This specialization guarantees
+/// that it can be instantiated at an incomplete T if none of its
+/// members are required.
+template <typename T>
+class SmallVector<T,0> : public SmallVectorImpl<T> {
+public:
+  SmallVector() : SmallVectorImpl<T>(0) {}
+
+  explicit SmallVector(unsigned Size, const T &Value = T())
+    : SmallVectorImpl<T>(0) {
+    this->reserve(Size);
+    while (Size--)
+      this->push_back(Value);
+  }
+
+  template<typename ItTy>
+  SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(0) {
+    this->append(S, E);
+  }
+
+  SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(0) {
+    SmallVectorImpl<T>::operator=(RHS);
+  }
+
+  SmallVector &operator=(const SmallVectorImpl<T> &RHS) {
+    return SmallVectorImpl<T>::operator=(RHS);
+  }
+
+};
+
 } // End llvm namespace
 
 namespace std {