Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f

1 files changed, 244 insertions, 0 deletions

diff --git a/include/llvm/ADT/iterator.h b/include/llvm/ADT/iterator.h
new file mode 100644
index 0000000..56041db
--- /dev/null
+++ b/include/llvm/ADT/iterator.h
@@ -0,0 +1,244 @@
+//===- iterator.h - Utilities for using and defining iterators --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_ITERATOR_H
+#define LLVM_ADT_ITERATOR_H
+
+#include <iterator>
+#include <cstddef>
+
+namespace llvm {
+
+/// \brief CRTP base class which implements the entire standard iterator facade
+/// in terms of a minimal subset of the interface.
+///
+/// Use this when it is reasonable to implement most of the iterator
+/// functionality in terms of a core subset. If you need special behavior or
+/// there are performance implications for this, you may want to override the
+/// relevant members instead.
+///
+/// Note, one abstraction that this does *not* provide is implementing
+/// subtraction in terms of addition by negating the difference. Negation isn't
+/// always information preserving, and I can see very reasonable iterator
+/// designs where this doesn't work well. It doesn't really force much added
+/// boilerplate anyways.
+///
+/// Another abstraction that this doesn't provide is implementing increment in
+/// terms of addition of one. These aren't equivalent for all iterator
+/// categories, and respecting that adds a lot of complexity for little gain.
+template <typename DerivedT, typename IteratorCategoryT, typename T,
+          typename DifferenceTypeT = std::ptrdiff_t, typename PointerT = T *,
+          typename ReferenceT = T &>
+class iterator_facade_base
+    : public std::iterator<IteratorCategoryT, T, DifferenceTypeT, PointerT,
+                           ReferenceT> {
+protected:
+  enum {
+    IsRandomAccess =
+        std::is_base_of<std::random_access_iterator_tag, IteratorCategoryT>::value,
+    IsBidirectional =
+        std::is_base_of<std::bidirectional_iterator_tag, IteratorCategoryT>::value,
+  };
+
+public:
+  DerivedT operator+(DifferenceTypeT n) const {
+    static_assert(
+        IsRandomAccess,
+        "The '+' operator is only defined for random access iterators.");
+    DerivedT tmp = *static_cast<const DerivedT *>(this);
+    tmp += n;
+    return tmp;
+  }
+  friend DerivedT operator+(DifferenceTypeT n, const DerivedT &i) {
+    static_assert(
+        IsRandomAccess,
+        "The '+' operator is only defined for random access iterators.");
+    return i + n;
+  }
+  DerivedT operator-(DifferenceTypeT n) const {
+    static_assert(
+        IsRandomAccess,
+        "The '-' operator is only defined for random access iterators.");
+    DerivedT tmp = *static_cast<const DerivedT *>(this);
+    tmp -= n;
+    return tmp;
+  }
+
+  DerivedT &operator++() {
+    return static_cast<DerivedT *>(this)->operator+=(1);
+  }
+  DerivedT operator++(int) {
+    DerivedT tmp = *static_cast<DerivedT *>(this);
+    ++*static_cast<DerivedT *>(this);
+    return tmp;
+  }
+  DerivedT &operator--() {
+    static_assert(
+        IsBidirectional,
+        "The decrement operator is only defined for bidirectional iterators.");
+    return static_cast<DerivedT *>(this)->operator-=(1);
+  }
+  DerivedT operator--(int) {
+    static_assert(
+        IsBidirectional,
+        "The decrement operator is only defined for bidirectional iterators.");
+    DerivedT tmp = *static_cast<DerivedT *>(this);
+    --*static_cast<DerivedT *>(this);
+    return tmp;
+  }
+
+  bool operator!=(const DerivedT &RHS) const {
+    return !static_cast<const DerivedT *>(this)->operator==(RHS);
+  }
+
+  bool operator>(const DerivedT &RHS) const {
+    static_assert(
+        IsRandomAccess,
+        "Relational operators are only defined for random access iterators.");
+    return !static_cast<const DerivedT *>(this)->operator<(RHS) &&
+           !static_cast<const DerivedT *>(this)->operator==(RHS);
+  }
+  bool operator<=(const DerivedT &RHS) const {
+    static_assert(
+        IsRandomAccess,
+        "Relational operators are only defined for random access iterators.");
+    return !static_cast<const DerivedT *>(this)->operator>(RHS);
+  }
+  bool operator>=(const DerivedT &RHS) const {
+    static_assert(
+        IsRandomAccess,
+        "Relational operators are only defined for random access iterators.");
+    return !static_cast<const DerivedT *>(this)->operator<(RHS);
+  }
+
+  PointerT operator->() const {
+    return &static_cast<const DerivedT *>(this)->operator*();
+  }
+  ReferenceT operator[](DifferenceTypeT n) const {
+    static_assert(IsRandomAccess,
+                  "Subscripting is only defined for random access iterators.");
+    return *static_cast<const DerivedT *>(this)->operator+(n);
+  }
+};
+
+/// \brief CRTP base class for adapting an iterator to a different type.
+///
+/// This class can be used through CRTP to adapt one iterator into another.
+/// Typically this is done through providing in the derived class a custom \c
+/// operator* implementation. Other methods can be overridden as well.
+template <
+    typename DerivedT, typename WrappedIteratorT,
+    typename IteratorCategoryT =
+        typename std::iterator_traits<WrappedIteratorT>::iterator_category,
+    typename T = typename std::iterator_traits<WrappedIteratorT>::value_type,
+    typename DifferenceTypeT =
+        typename std::iterator_traits<WrappedIteratorT>::difference_type,
+    typename PointerT = T *, typename ReferenceT = T &,
+    // Don't provide these, they are mostly to act as aliases below.
+    typename WrappedTraitsT = std::iterator_traits<WrappedIteratorT>>
+class iterator_adaptor_base
+    : public iterator_facade_base<DerivedT, IteratorCategoryT, T,
+                                  DifferenceTypeT, PointerT, ReferenceT> {
+  typedef typename iterator_adaptor_base::iterator_facade_base BaseT;
+
+protected:
+  WrappedIteratorT I;
+
+  iterator_adaptor_base() {}
+
+  template <typename U>
+  explicit iterator_adaptor_base(
+      U &&u,
+      typename std::enable_if<
+          !std::is_base_of<typename std::remove_cv<
+                               typename std::remove_reference<U>::type>::type,
+                           DerivedT>::value,
+          int>::type = 0)
+      : I(std::forward<U &&>(u)) {}
+
+public:
+  typedef DifferenceTypeT difference_type;
+
+  DerivedT &operator+=(difference_type n) {
+    static_assert(
+        BaseT::IsRandomAccess,
+        "The '+=' operator is only defined for random access iterators.");
+    I += n;
+    return *static_cast<DerivedT *>(this);
+  }
+  DerivedT &operator-=(difference_type n) {
+    static_assert(
+        BaseT::IsRandomAccess,
+        "The '-=' operator is only defined for random access iterators.");
+    I -= n;
+    return *static_cast<DerivedT *>(this);
+  }
+  using BaseT::operator-;
+  difference_type operator-(const DerivedT &RHS) const {
+    static_assert(
+        BaseT::IsRandomAccess,
+        "The '-' operator is only defined for random access iterators.");
+    return I - RHS.I;
+  }
+
+  // We have to explicitly provide ++ and -- rather than letting the facade
+  // forward to += because WrappedIteratorT might not support +=.
+  using BaseT::operator++;
+  DerivedT &operator++() {
+    ++I;
+    return *static_cast<DerivedT *>(this);
+  }
+  using BaseT::operator--;
+  DerivedT &operator--() {
+    static_assert(
+        BaseT::IsBidirectional,
+        "The decrement operator is only defined for bidirectional iterators.");
+    --I;
+    return *static_cast<DerivedT *>(this);
+  }
+
+  bool operator==(const DerivedT &RHS) const { return I == RHS.I; }
+  bool operator<(const DerivedT &RHS) const {
+    static_assert(
+        BaseT::IsRandomAccess,
+        "Relational operators are only defined for random access iterators.");
+    return I < RHS.I;
+  }
+
+  ReferenceT operator*() const { return *I; }
+};
+
+/// \brief An iterator type that allows iterating over the pointees via some
+/// other iterator.
+///
+/// The typical usage of this is to expose a type that iterates over Ts, but
+/// which is implemented with some iterator over T*s:
+///
+/// \code
+///   typedef pointee_iterator<SmallVectorImpl<T *>::iterator> iterator;
+/// \endcode
+template <typename WrappedIteratorT,
+          typename T = typename std::remove_reference<
+              decltype(**std::declval<WrappedIteratorT>())>::type>
+struct pointee_iterator
+    : iterator_adaptor_base<
+          pointee_iterator<WrappedIteratorT>, WrappedIteratorT,
+          typename std::iterator_traits<WrappedIteratorT>::iterator_category,
+          T> {
+  pointee_iterator() {}
+  template <typename U>
+  pointee_iterator(U &&u)
+      : pointee_iterator::iterator_adaptor_base(std::forward<U &&>(u)) {}
+
+  T &operator*() const { return **this->I; }
+};
+
+}
+
+#endif