From df1c971e39e245cda39d4a2e63934dd2da5bb462 Mon Sep 17 00:00:00 2001
From: Eugene Zelenko <eugene.zelenko@gmail.com>
Date: Sat, 28 Oct 2017 00:24:26 +0000
Subject: [PATCH] [ADT] Fix some Clang-tidy modernize and Include What You Use
 warnings; other minor fixes (NFC).

llvm-svn: 316818
---
 include/llvm/ADT/FoldingSet.h     |  44 ++++-------
 include/llvm/ADT/PointerIntPair.h |  31 +++++---
 include/llvm/ADT/PointerSumType.h |  50 ++++++------
 include/llvm/ADT/PointerUnion.h   |  79 ++++++++++---------
 include/llvm/ADT/STLExtras.h      | 124 ++++++++++++++++--------------
 include/llvm/ADT/Twine.h          |  54 ++++++-------
 6 files changed, 196 insertions(+), 186 deletions(-)

diff --git a/include/llvm/ADT/FoldingSet.h b/include/llvm/ADT/FoldingSet.h
index c5987a947e1..e363e69d032 100644
--- a/include/llvm/ADT/FoldingSet.h
+++ b/include/llvm/ADT/FoldingSet.h
@@ -1,4 +1,4 @@
-//===-- llvm/ADT/FoldingSet.h - Uniquing Hash Set ---------------*- C++ -*-===//
+//===- llvm/ADT/FoldingSet.h - Uniquing Hash Set ----------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -115,11 +115,9 @@ class FoldingSetBase {
 
 protected:
   /// Buckets - Array of bucket chains.
-  ///
   void **Buckets;
 
   /// NumBuckets - Length of the Buckets array.  Always a power of 2.
-  ///
   unsigned NumBuckets;
 
   /// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes
@@ -135,14 +133,13 @@ public:
   //===--------------------------------------------------------------------===//
   /// Node - This class is used to maintain the singly linked bucket list in
   /// a folding set.
-  ///
   class Node {
   private:
     // NextInFoldingSetBucket - next link in the bucket list.
-    void *NextInFoldingSetBucket;
+    void *NextInFoldingSetBucket = nullptr;
 
   public:
-    Node() : NextInFoldingSetBucket(nullptr) {}
+    Node() = default;
 
     // Accessors
     void *getNextInBucket() const { return NextInFoldingSetBucket; }
@@ -221,7 +218,6 @@ protected:
 
 /// DefaultFoldingSetTrait - This class provides default implementations
 /// for FoldingSetTrait implementations.
-///
 template<typename T> struct DefaultFoldingSetTrait {
   static void Profile(const T &X, FoldingSetNodeID &ID) {
     X.Profile(ID);
@@ -307,7 +303,6 @@ public:
 /// FoldingSetNodeID - This class is used to gather all the unique data bits of
 /// a node.  When all the bits are gathered this class is used to produce a
 /// hash value for the node.
-///
 class FoldingSetNodeID {
   /// Bits - Vector of all the data bits that make the node unique.
   /// Use a SmallVector to avoid a heap allocation in the common case.
@@ -320,7 +315,6 @@ public:
     : Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {}
 
   /// Add* - Add various data types to Bit data.
-  ///
   void AddPointer(const void *Ptr);
   void AddInteger(signed I);
   void AddInteger(unsigned I);
@@ -344,7 +338,6 @@ public:
   unsigned ComputeHash() const;
 
   /// operator== - Used to compare two nodes to each other.
-  ///
   bool operator==(const FoldingSetNodeID &RHS) const;
   bool operator==(const FoldingSetNodeIDRef RHS) const;
 
@@ -363,7 +356,7 @@ public:
 };
 
 // Convenience type to hide the implementation of the folding set.
-typedef FoldingSetBase::Node FoldingSetNode;
+using FoldingSetNode = FoldingSetBase::Node;
 template<class T> class FoldingSetIterator;
 template<class T> class FoldingSetBucketIterator;
 
@@ -415,15 +408,17 @@ protected:
   ~FoldingSetImpl() = default;
 
 public:
-  typedef FoldingSetIterator<T> iterator;
+  using iterator = FoldingSetIterator<T>;
+
   iterator begin() { return iterator(Buckets); }
   iterator end() { return iterator(Buckets+NumBuckets); }
 
-  typedef FoldingSetIterator<const T> const_iterator;
+  using const_iterator = FoldingSetIterator<const T>;
+
   const_iterator begin() const { return const_iterator(Buckets); }
   const_iterator end() const { return const_iterator(Buckets+NumBuckets); }
 
-  typedef FoldingSetBucketIterator<T> bucket_iterator;
+  using bucket_iterator = FoldingSetBucketIterator<T>;
 
   bucket_iterator bucket_begin(unsigned hash) {
     return bucket_iterator(Buckets + (hash & (NumBuckets-1)));
@@ -503,9 +498,7 @@ template <class T> class FoldingSet final : public FoldingSetImpl<T> {
   }
 
 public:
-  explicit FoldingSet(unsigned Log2InitSize = 6)
-      : Super(Log2InitSize) {}
-
+  explicit FoldingSet(unsigned Log2InitSize = 6) : Super(Log2InitSize) {}
   FoldingSet(FoldingSet &&Arg) = default;
   FoldingSet &operator=(FoldingSet &&RHS) = default;
 };
@@ -552,8 +545,7 @@ class ContextualFoldingSet final : public FoldingSetImpl<T> {
 
 public:
   explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6)
-  : Super(Log2InitSize), Context(Context)
-  {}
+      : Super(Log2InitSize), Context(Context) {}
 
   Ctx getContext() const { return Context; }
 };
@@ -569,15 +561,15 @@ class FoldingSetVector {
   VectorT Vector;
 
 public:
-  explicit FoldingSetVector(unsigned Log2InitSize = 6)
-      : Set(Log2InitSize) {
-  }
+  explicit FoldingSetVector(unsigned Log2InitSize = 6) : Set(Log2InitSize) {}
+
+  using iterator = pointee_iterator<typename VectorT::iterator>;
 
-  typedef pointee_iterator<typename VectorT::iterator> iterator;
   iterator begin() { return Vector.begin(); }
   iterator end()   { return Vector.end(); }
 
-  typedef pointee_iterator<typename VectorT::const_iterator> const_iterator;
+  using const_iterator = pointee_iterator<typename VectorT::const_iterator>;
+
   const_iterator begin() const { return Vector.begin(); }
   const_iterator end()   const { return Vector.end(); }
 
@@ -667,15 +659,13 @@ public:
 /// FoldingSetBucketIteratorImpl - This is the common bucket iterator support
 /// shared by all folding sets, which knows how to walk a particular bucket
 /// of a folding set hash table.
-
 class FoldingSetBucketIteratorImpl {
 protected:
   void *Ptr;
 
   explicit FoldingSetBucketIteratorImpl(void **Bucket);
 
-  FoldingSetBucketIteratorImpl(void **Bucket, bool)
-    : Ptr(Bucket) {}
+  FoldingSetBucketIteratorImpl(void **Bucket, bool) : Ptr(Bucket) {}
 
   void advance() {
     void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket();
diff --git a/include/llvm/ADT/PointerIntPair.h b/include/llvm/ADT/PointerIntPair.h
index eb5a3369900..884d05155bf 100644
--- a/include/llvm/ADT/PointerIntPair.h
+++ b/include/llvm/ADT/PointerIntPair.h
@@ -14,15 +14,14 @@
 #ifndef LLVM_ADT_POINTERINTPAIR_H
 #define LLVM_ADT_POINTERINTPAIR_H
 
-#include "llvm/Support/Compiler.h"
 #include "llvm/Support/PointerLikeTypeTraits.h"
 #include <cassert>
+#include <cstdint>
 #include <limits>
 
 namespace llvm {
 
 template <typename T> struct DenseMapInfo;
-
 template <typename PointerT, unsigned IntBits, typename PtrTraits>
 struct PointerIntPairInfo;
 
@@ -39,25 +38,24 @@ struct PointerIntPairInfo;
 /// for something else.  For example, this allows:
 ///   PointerIntPair<PointerIntPair<void*, 1, bool>, 1, bool>
 /// ... and the two bools will land in different bits.
-///
 template <typename PointerTy, unsigned IntBits, typename IntType = unsigned,
           typename PtrTraits = PointerLikeTypeTraits<PointerTy>,
           typename Info = PointerIntPairInfo<PointerTy, IntBits, PtrTraits>>
 class PointerIntPair {
-  intptr_t Value;
+  intptr_t Value = 0;
 
 public:
-  constexpr PointerIntPair() : Value(0) {}
+  constexpr PointerIntPair() = default;
+
   PointerIntPair(PointerTy PtrVal, IntType IntVal) {
     setPointerAndInt(PtrVal, IntVal);
   }
+
   explicit PointerIntPair(PointerTy PtrVal) { initWithPointer(PtrVal); }
 
   PointerTy getPointer() const { return Info::getPointer(Value); }
 
-  IntType getInt() const {
-    return (IntType)Info::getInt(Value);
-  }
+  IntType getInt() const { return (IntType)Info::getInt(Value); }
 
   void setPointer(PointerTy PtrVal) {
     Value = Info::updatePointer(Value, PtrVal);
@@ -88,6 +86,7 @@ public:
   }
 
   void *getOpaqueValue() const { return reinterpret_cast<void *>(Value); }
+
   void setFromOpaqueValue(void *Val) {
     Value = reinterpret_cast<intptr_t>(Val);
   }
@@ -108,14 +107,18 @@ public:
   bool operator==(const PointerIntPair &RHS) const {
     return Value == RHS.Value;
   }
+
   bool operator!=(const PointerIntPair &RHS) const {
     return Value != RHS.Value;
   }
+
   bool operator<(const PointerIntPair &RHS) const { return Value < RHS.Value; }
   bool operator>(const PointerIntPair &RHS) const { return Value > RHS.Value; }
+
   bool operator<=(const PointerIntPair &RHS) const {
     return Value <= RHS.Value;
   }
+
   bool operator>=(const PointerIntPair &RHS) const {
     return Value >= RHS.Value;
   }
@@ -180,21 +183,25 @@ struct isPodLike<PointerIntPair<PointerTy, IntBits, IntType>> {
 // Provide specialization of DenseMapInfo for PointerIntPair.
 template <typename PointerTy, unsigned IntBits, typename IntType>
 struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType>> {
-  typedef PointerIntPair<PointerTy, IntBits, IntType> Ty;
+  using Ty = PointerIntPair<PointerTy, IntBits, IntType>;
+
   static Ty getEmptyKey() {
     uintptr_t Val = static_cast<uintptr_t>(-1);
     Val <<= PointerLikeTypeTraits<Ty>::NumLowBitsAvailable;
     return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
   }
+
   static Ty getTombstoneKey() {
     uintptr_t Val = static_cast<uintptr_t>(-2);
     Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
     return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
   }
+
   static unsigned getHashValue(Ty V) {
     uintptr_t IV = reinterpret_cast<uintptr_t>(V.getOpaqueValue());
     return unsigned(IV) ^ unsigned(IV >> 9);
   }
+
   static bool isEqual(const Ty &LHS, const Ty &RHS) { return LHS == RHS; }
 };
 
@@ -207,16 +214,20 @@ struct PointerLikeTypeTraits<
   getAsVoidPointer(const PointerIntPair<PointerTy, IntBits, IntType> &P) {
     return P.getOpaqueValue();
   }
+
   static inline PointerIntPair<PointerTy, IntBits, IntType>
   getFromVoidPointer(void *P) {
     return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P);
   }
+
   static inline PointerIntPair<PointerTy, IntBits, IntType>
   getFromVoidPointer(const void *P) {
     return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P);
   }
+
   enum { NumLowBitsAvailable = PtrTraits::NumLowBitsAvailable - IntBits };
 };
 
 } // end namespace llvm
-#endif
+
+#endif // LLVM_ADT_POINTERINTPAIR_H
diff --git a/include/llvm/ADT/PointerSumType.h b/include/llvm/ADT/PointerSumType.h
index 1a49e062dc2..e37957160d9 100644
--- a/include/llvm/ADT/PointerSumType.h
+++ b/include/llvm/ADT/PointerSumType.h
@@ -11,8 +11,10 @@
 #define LLVM_ADT_POINTERSUMTYPE_H
 
 #include "llvm/ADT/DenseMapInfo.h"
-#include "llvm/Support/Compiler.h"
 #include "llvm/Support/PointerLikeTypeTraits.h"
+#include <cassert>
+#include <cstdint>
+#include <type_traits>
 
 namespace llvm {
 
@@ -24,16 +26,15 @@ template <uintptr_t N, typename PointerArgT,
           typename TraitsArgT = PointerLikeTypeTraits<PointerArgT>>
 struct PointerSumTypeMember {
   enum { Tag = N };
-  typedef PointerArgT PointerT;
-  typedef TraitsArgT TraitsT;
+  using PointerT = PointerArgT;
+  using TraitsT = TraitsArgT;
 };
 
 namespace detail {
 
-template <typename TagT, typename... MemberTs>
-struct PointerSumTypeHelper;
+template <typename TagT, typename... MemberTs> struct PointerSumTypeHelper;
 
-}
+} // end namespace detail
 
 /// A sum type over pointer-like types.
 ///
@@ -60,12 +61,12 @@ struct PointerSumTypeHelper;
 /// There is no support for constructing or accessing with a dynamic tag as
 /// that would fundamentally violate the type safety provided by the sum type.
 template <typename TagT, typename... MemberTs> class PointerSumType {
-  uintptr_t Value;
+  uintptr_t Value = 0;
 
-  typedef detail::PointerSumTypeHelper<TagT, MemberTs...> HelperT;
+  using HelperT = detail::PointerSumTypeHelper<TagT, MemberTs...>;
 
 public:
-  constexpr PointerSumType() : Value(0) {}
+  constexpr PointerSumType() = default;
 
   /// A typed constructor for a specific tagged member of the sum type.
   template <TagT N>
@@ -128,14 +129,14 @@ struct PointerSumTypeHelper : MemberTs... {
   template <TagT N> static void LookupOverload(...);
   template <TagT N> struct Lookup {
     // Compute a particular member type by resolving the lookup helper ovorload.
-    typedef decltype(LookupOverload<N>(
-        static_cast<PointerSumTypeHelper *>(nullptr))) MemberT;
+    using MemberT = decltype(
+        LookupOverload<N>(static_cast<PointerSumTypeHelper *>(nullptr)));
 
     /// The Nth member's pointer type.
-    typedef typename MemberT::PointerT PointerT;
+    using PointerT = typename MemberT::PointerT;
 
     /// The Nth member's traits type.
-    typedef typename MemberT::TraitsT TraitsT;
+    using TraitsT = typename MemberT::TraitsT;
   };
 
   // Next we need to compute the number of bits available for the discriminant
@@ -171,35 +172,36 @@ struct PointerSumTypeHelper : MemberTs... {
                 "Each member must pass the checker.");
 };
 
-}
+} // end namespace detail
 
 // Teach DenseMap how to use PointerSumTypes as keys.
 template <typename TagT, typename... MemberTs>
 struct DenseMapInfo<PointerSumType<TagT, MemberTs...>> {
-  typedef PointerSumType<TagT, MemberTs...> SumType;
-
-  typedef detail::PointerSumTypeHelper<TagT, MemberTs...> HelperT;
+  using SumType = PointerSumType<TagT, MemberTs...>;
+  using HelperT = detail::PointerSumTypeHelper<TagT, MemberTs...>;
   enum { SomeTag = HelperT::MinTag };
-  typedef typename HelperT::template Lookup<HelperT::MinTag>::PointerT
-      SomePointerT;
-  typedef DenseMapInfo<SomePointerT> SomePointerInfo;
+  using SomePointerT =
+      typename HelperT::template Lookup<HelperT::MinTag>::PointerT;
+  using SomePointerInfo = DenseMapInfo<SomePointerT>;
 
   static inline SumType getEmptyKey() {
     return SumType::create<SomeTag>(SomePointerInfo::getEmptyKey());
   }
+
   static inline SumType getTombstoneKey() {
-    return SumType::create<SomeTag>(
-        SomePointerInfo::getTombstoneKey());
+    return SumType::create<SomeTag>(SomePointerInfo::getTombstoneKey());
   }
+
   static unsigned getHashValue(const SumType &Arg) {
     uintptr_t OpaqueValue = Arg.getOpaqueValue();
     return DenseMapInfo<uintptr_t>::getHashValue(OpaqueValue);
   }
+
   static bool isEqual(const SumType &LHS, const SumType &RHS) {
     return LHS == RHS;
   }
 };
 
-}
+} // end namespace llvm
 
-#endif
+#endif // LLVM_ADT_POINTERSUMTYPE_H
diff --git a/include/llvm/ADT/PointerUnion.h b/include/llvm/ADT/PointerUnion.h
index d019edb57e5..4276859e925 100644
--- a/include/llvm/ADT/PointerUnion.h
+++ b/include/llvm/ADT/PointerUnion.h
@@ -25,7 +25,7 @@
 namespace llvm {
 
 template <typename T> struct PointerUnionTypeSelectorReturn {
-  typedef T Return;
+  using Return = T;
 };
 
 /// Get a type based on whether two types are the same or not.
@@ -33,25 +33,25 @@ template <typename T> struct PointerUnionTypeSelectorReturn {
 /// For:
 ///
 /// \code
-///   typedef typename PointerUnionTypeSelector<T1, T2, EQ, NE>::Return Ret;
+///   using Ret = typename PointerUnionTypeSelector<T1, T2, EQ, NE>::Return;
 /// \endcode
 ///
 /// Ret will be EQ type if T1 is same as T2 or NE type otherwise.
 template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
 struct PointerUnionTypeSelector {
-  typedef typename PointerUnionTypeSelectorReturn<RET_NE>::Return Return;
+  using Return = typename PointerUnionTypeSelectorReturn<RET_NE>::Return;
 };
 
 template <typename T, typename RET_EQ, typename RET_NE>
 struct PointerUnionTypeSelector<T, T, RET_EQ, RET_NE> {
-  typedef typename PointerUnionTypeSelectorReturn<RET_EQ>::Return Return;
+  using Return = typename PointerUnionTypeSelectorReturn<RET_EQ>::Return;
 };
 
 template <typename T1, typename T2, typename RET_EQ, typename RET_NE>
 struct PointerUnionTypeSelectorReturn<
     PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE>> {
-  typedef
-      typename PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE>::Return Return;
+  using Return =
+      typename PointerUnionTypeSelector<T1, T2, RET_EQ, RET_NE>::Return;
 };
 
 /// Provide PointerLikeTypeTraits for void* that is used by PointerUnion
@@ -86,8 +86,8 @@ public:
 ///    X = P.get<int*>();     // runtime assertion failure.
 template <typename PT1, typename PT2> class PointerUnion {
 public:
-  typedef PointerIntPair<void *, 1, bool, PointerUnionUIntTraits<PT1, PT2>>
-      ValTy;
+  using ValTy =
+      PointerIntPair<void *, 1, bool, PointerUnionUIntTraits<PT1, PT2>>;
 
 private:
   ValTy Val;
@@ -102,7 +102,6 @@ private:
 
 public:
   PointerUnion() = default;
-
   PointerUnion(PT1 V)
       : Val(const_cast<void *>(
             PointerLikeTypeTraits<PT1>::getAsVoidPointer(V))) {}
@@ -117,14 +116,15 @@ public:
     // we recursively strip off low bits if we have a nested PointerUnion.
     return !PointerLikeTypeTraits<PT1>::getFromVoidPointer(Val.getPointer());
   }
+
   explicit operator bool() const { return !isNull(); }
 
   /// Test if the Union currently holds the type matching T.
   template <typename T> int is() const {
-    typedef typename ::llvm::PointerUnionTypeSelector<
-        PT1, T, IsPT1, ::llvm::PointerUnionTypeSelector<
-                           PT2, T, IsPT2, UNION_DOESNT_CONTAIN_TYPE<T>>>::Return
-        Ty;
+    using Ty = typename ::llvm::PointerUnionTypeSelector<
+        PT1, T, IsPT1,
+        ::llvm::PointerUnionTypeSelector<PT2, T, IsPT2,
+                                         UNION_DOESNT_CONTAIN_TYPE<T>>>::Return;
     int TyNo = Ty::Num;
     return static_cast<int>(Val.getInt()) == TyNo;
   }
@@ -158,7 +158,8 @@ public:
     assert(
         get<PT1>() == Val.getPointer() &&
         "Can't get the address because PointerLikeTypeTraits changes the ptr");
-    return const_cast<PT1 *>(reinterpret_cast<const PT1 *>(Val.getAddrOfPointer()));
+    return const_cast<PT1 *>(
+        reinterpret_cast<const PT1 *>(Val.getAddrOfPointer()));
   }
 
   /// Assignment from nullptr which just clears the union.
@@ -227,19 +228,22 @@ struct PointerLikeTypeTraits<PointerUnion<PT1, PT2>> {
 /// for usage.
 template <typename PT1, typename PT2, typename PT3> class PointerUnion3 {
 public:
-  typedef PointerUnion<PT1, PT2> InnerUnion;
-  typedef PointerUnion<InnerUnion, PT3> ValTy;
+  using InnerUnion = PointerUnion<PT1, PT2>;
+  using ValTy = PointerUnion<InnerUnion, PT3>;
 
 private:
   ValTy Val;
 
   struct IsInnerUnion {
     ValTy Val;
+
     IsInnerUnion(ValTy val) : Val(val) {}
+
     template <typename T> int is() const {
       return Val.template is<InnerUnion>() &&
              Val.template get<InnerUnion>().template is<T>();
     }
+
     template <typename T> T get() const {
       return Val.template get<InnerUnion>().template get<T>();
     }
@@ -247,14 +251,15 @@ private:
 
   struct IsPT3 {
     ValTy Val;
+
     IsPT3(ValTy val) : Val(val) {}
+
     template <typename T> int is() const { return Val.template is<T>(); }
     template <typename T> T get() const { return Val.template get<T>(); }
   };
 
 public:
   PointerUnion3() = default;
-
   PointerUnion3(PT1 V) { Val = InnerUnion(V); }
   PointerUnion3(PT2 V) { Val = InnerUnion(V); }
   PointerUnion3(PT3 V) { Val = V; }
@@ -267,10 +272,9 @@ public:
   /// Test if the Union currently holds the type matching T.
   template <typename T> int is() const {
     // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
-    typedef typename ::llvm::PointerUnionTypeSelector<
+    using Ty = typename ::llvm::PointerUnionTypeSelector<
         PT1, T, IsInnerUnion,
-        ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3>>::Return
-        Ty;
+        ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3>>::Return;
     return Ty(Val).template is<T>();
   }
 
@@ -280,10 +284,9 @@ public:
   template <typename T> T get() const {
     assert(is<T>() && "Invalid accessor called");
     // If T is PT1/PT2 choose IsInnerUnion otherwise choose IsPT3.
-    typedef typename ::llvm::PointerUnionTypeSelector<
+    using Ty = typename ::llvm::PointerUnionTypeSelector<
         PT1, T, IsInnerUnion,
-        ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3>>::Return
-        Ty;
+        ::llvm::PointerUnionTypeSelector<PT2, T, IsInnerUnion, IsPT3>>::Return;
     return Ty(Val).template get<T>();
   }
 
@@ -348,16 +351,15 @@ struct PointerLikeTypeTraits<PointerUnion3<PT1, PT2, PT3>> {
 template <typename PT1, typename PT2, typename PT3, typename PT4>
 class PointerUnion4 {
 public:
-  typedef PointerUnion<PT1, PT2> InnerUnion1;
-  typedef PointerUnion<PT3, PT4> InnerUnion2;
-  typedef PointerUnion<InnerUnion1, InnerUnion2> ValTy;
+  using InnerUnion1 = PointerUnion<PT1, PT2>;
+  using InnerUnion2 = PointerUnion<PT3, PT4>;
+  using ValTy = PointerUnion<InnerUnion1, InnerUnion2>;
 
 private:
   ValTy Val;
 
 public:
   PointerUnion4() = default;
-
   PointerUnion4(PT1 V) { Val = InnerUnion1(V); }
   PointerUnion4(PT2 V) { Val = InnerUnion1(V); }
   PointerUnion4(PT3 V) { Val = InnerUnion2(V); }
@@ -371,9 +373,10 @@ public:
   /// Test if the Union currently holds the type matching T.
   template <typename T> int is() const {
     // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
-    typedef typename ::llvm::PointerUnionTypeSelector<
-        PT1, T, InnerUnion1, ::llvm::PointerUnionTypeSelector<
-                                 PT2, T, InnerUnion1, InnerUnion2>>::Return Ty;
+    using Ty = typename ::llvm::PointerUnionTypeSelector<
+        PT1, T, InnerUnion1,
+        ::llvm::PointerUnionTypeSelector<PT2, T, InnerUnion1,
+                                         InnerUnion2>>::Return;
     return Val.template is<Ty>() && Val.template get<Ty>().template is<T>();
   }
 
@@ -383,9 +386,10 @@ public:
   template <typename T> T get() const {
     assert(is<T>() && "Invalid accessor called");
     // If T is PT1/PT2 choose InnerUnion1 otherwise choose InnerUnion2.
-    typedef typename ::llvm::PointerUnionTypeSelector<
-        PT1, T, InnerUnion1, ::llvm::PointerUnionTypeSelector<
-                                 PT2, T, InnerUnion1, InnerUnion2>>::Return Ty;
+    using Ty = typename ::llvm::PointerUnionTypeSelector<
+        PT1, T, InnerUnion1,
+        ::llvm::PointerUnionTypeSelector<PT2, T, InnerUnion1,
+                                         InnerUnion2>>::Return;
     return Val.template get<Ty>().template get<T>();
   }
 
@@ -452,18 +456,21 @@ struct PointerLikeTypeTraits<PointerUnion4<PT1, PT2, PT3, PT4>> {
 
 // Teach DenseMap how to use PointerUnions as keys.
 template <typename T, typename U> struct DenseMapInfo<PointerUnion<T, U>> {
-  typedef PointerUnion<T, U> Pair;
-  typedef DenseMapInfo<T> FirstInfo;
-  typedef DenseMapInfo<U> SecondInfo;
+  using Pair = PointerUnion<T, U>;
+  using FirstInfo = DenseMapInfo<T>;
+  using SecondInfo = DenseMapInfo<U>;
 
   static inline Pair getEmptyKey() { return Pair(FirstInfo::getEmptyKey()); }
+
   static inline Pair getTombstoneKey() {
     return Pair(FirstInfo::getTombstoneKey());
   }
+
   static unsigned getHashValue(const Pair &PairVal) {
     intptr_t key = (intptr_t)PairVal.getOpaqueValue();
     return DenseMapInfo<intptr_t>::getHashValue(key);
   }
+
   static bool isEqual(const Pair &LHS, const Pair &RHS) {
     return LHS.template is<T>() == RHS.template is<T>() &&
            (LHS.template is<T>() ? FirstInfo::isEqual(LHS.template get<T>(),
diff --git a/include/llvm/ADT/STLExtras.h b/include/llvm/ADT/STLExtras.h
index 1d1eb601a33..3ec9dfe5de0 100644
--- a/include/llvm/ADT/STLExtras.h
+++ b/include/llvm/ADT/STLExtras.h
@@ -17,23 +17,24 @@
 #ifndef LLVM_ADT_STLEXTRAS_H
 #define LLVM_ADT_STLEXTRAS_H
 
-#include <algorithm> // for std::all_of
-#include <cassert>
-#include <cstddef> // for std::size_t
-#include <cstdlib> // for qsort
-#include <functional>
-#include <iterator>
-#include <limits>
-#include <memory>
-#include <tuple>
-#include <utility> // for std::pair
-
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/iterator.h"
 #include "llvm/ADT/iterator_range.h"
-#include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <functional>
+#include <initializer_list>
+#include <iterator>
+#include <limits>
+#include <memory>
+#include <tuple>
+#include <type_traits>
+#include <utility>
 
 namespace llvm {
 
@@ -50,7 +51,7 @@ template <typename RangeT>
 using ValueOfRange = typename std::remove_reference<decltype(
     *std::begin(std::declval<RangeT &>()))>::type;
 
-} // End detail namespace
+} // end namespace detail
 
 //===----------------------------------------------------------------------===//
 //     Extra additions to <functional>
@@ -58,6 +59,7 @@ using ValueOfRange = typename std::remove_reference<decltype(
 
 template <class Ty> struct identity {
   using argument_type = Ty;
+
   Ty &operator()(Ty &self) const {
     return self;
   }
@@ -88,7 +90,7 @@ template<typename Fn> class function_ref;
 
 template<typename Ret, typename ...Params>
 class function_ref<Ret(Params...)> {
-  Ret (*callback)(intptr_t callable, Params ...params);
+  Ret (*callback)(intptr_t callable, Params ...params) = nullptr;
   intptr_t callable;
 
   template<typename Callable>
@@ -98,7 +100,7 @@ class function_ref<Ret(Params...)> {
   }
 
 public:
-  function_ref() : callback(nullptr) {}
+  function_ref() = default;
 
   template <typename Callable>
   function_ref(Callable &&callable,
@@ -107,6 +109,7 @@ public:
                                  function_ref>::value>::type * = nullptr)
       : callback(callback_fn<typename std::remove_reference<Callable>::type>),
         callable(reinterpret_cast<intptr_t>(&callable)) {}
+
   Ret operator()(Params ...params) const {
     return callback(callable, std::forward<Params>(params)...);
   }
@@ -118,41 +121,34 @@ public:
 // delete on something.  It is used like this:
 //
 //   for_each(V.begin(), B.end(), deleter<Interval>);
-//
 template <class T>
 inline void deleter(T *Ptr) {
   delete Ptr;
 }
 
-
-
 //===----------------------------------------------------------------------===//
 //     Extra additions to <iterator>
 //===----------------------------------------------------------------------===//
 
 // mapped_iterator - This is a simple iterator adapter that causes a function to
 // be applied whenever operator* is invoked on the iterator.
-//
 template <class RootIt, class UnaryFunc>
 class mapped_iterator {
   RootIt current;
   UnaryFunc Fn;
+
 public:
-  typedef typename std::iterator_traits<RootIt>::iterator_category
-          iterator_category;
-  typedef typename std::iterator_traits<RootIt>::difference_type
-          difference_type;
-  typedef decltype(std::declval<UnaryFunc>()(*std::declval<RootIt>()))
-          value_type;
+  using iterator_category =
+      typename std::iterator_traits<RootIt>::iterator_category;
+  using difference_type =
+      typename std::iterator_traits<RootIt>::difference_type;
+  using value_type =
+      decltype(std::declval<UnaryFunc>()(*std::declval<RootIt>()));
 
-  typedef void pointer;
-  //typedef typename UnaryFunc::result_type *pointer;
-  typedef void reference;        // Can't modify value returned by fn
+  using pointer = void;
+  using reference = void; // Can't modify value returned by fn
 
-  typedef RootIt iterator_type;
-
-  inline const RootIt &getCurrent() const { return current; }
-  inline const UnaryFunc &getFunc() const { return Fn; }
+  using iterator_type = RootIt;
 
   inline explicit mapped_iterator(const RootIt &I, UnaryFunc F)
     : current(I), Fn(F) {}
@@ -204,6 +200,9 @@ public:
   difference_type operator-(const mapped_iterator &X) const {
     return current - X.current;
   }
+
+  inline const RootIt &getCurrent() const { return current; }
+  inline const UnaryFunc &getFunc() const { return Fn; }
 };
 
 template <class Iterator, class Func>
@@ -213,10 +212,8 @@ operator+(typename mapped_iterator<Iterator, Func>::difference_type N,
   return mapped_iterator<Iterator, Func>(X.getCurrent() - N, X.getFunc());
 }
 
-
 // map_iterator - Provide a convenient way to create mapped_iterators, just like
 // make_pair is useful for creating pairs...
-//
 template <class ItTy, class FuncTy>
 inline mapped_iterator<ItTy, FuncTy> map_iterator(const ItTy &I, FuncTy F) {
   return mapped_iterator<ItTy, FuncTy>(I, F);
@@ -224,8 +221,8 @@ inline mapped_iterator<ItTy, FuncTy> map_iterator(const ItTy &I, FuncTy F) {
 
 /// Helper to determine if type T has a member called rbegin().
 template <typename Ty> class has_rbegin_impl {
-  typedef char yes[1];
-  typedef char no[2];
+  using yes = char[1];
+  using no = char[2];
 
   template <typename Inner>
   static yes& test(Inner *I, decltype(I->rbegin()) * = nullptr);
@@ -363,12 +360,13 @@ template <size_t... I> struct index_sequence;
 template <class... Ts> struct index_sequence_for;
 
 namespace detail {
+
 using std::declval;
 
 // We have to alias this since inlining the actual type at the usage site
 // in the parameter list of iterator_facade_base<> below ICEs MSVC 2017.
 template<typename... Iters> struct ZipTupleType {
-  typedef std::tuple<decltype(*declval<Iters>())...> type;
+  using type = std::tuple<decltype(*declval<Iters>())...>;
 };
 
 template <typename ZipType, typename... Iters>
@@ -454,11 +452,11 @@ class zip_shortest : public zip_common<zip_shortest<Iters...>, Iters...> {
 public:
   using Base = zip_common<zip_shortest<Iters...>, Iters...>;
 
+  zip_shortest(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
+
   bool operator==(const zip_shortest<Iters...> &other) const {
     return !test(other, index_sequence_for<Iters...>{});
   }
-
-  zip_shortest(Iters &&... ts) : Base(std::forward<Iters>(ts)...) {}
 };
 
 template <template <typename...> class ItType, typename... Args> class zippy {
@@ -481,11 +479,13 @@ private:
   }
 
 public:
+  zippy(Args &&... ts_) : ts(std::forward<Args>(ts_)...) {}
+
   iterator begin() const { return begin_impl(index_sequence_for<Args...>{}); }
   iterator end() const { return end_impl(index_sequence_for<Args...>{}); }
-  zippy(Args &&... ts_) : ts(std::forward<Args>(ts_)...) {}
 };
-} // End detail namespace
+
+} // end namespace detail
 
 /// zip iterator for two or more iteratable types.
 template <typename T, typename U, typename... Args>
@@ -518,7 +518,7 @@ template <typename ValueT, typename... IterTs>
 class concat_iterator
     : public iterator_facade_base<concat_iterator<ValueT, IterTs...>,
                                   std::forward_iterator_tag, ValueT> {
-  typedef typename concat_iterator::iterator_facade_base BaseT;
+  using BaseT = typename concat_iterator::iterator_facade_base;
 
   /// We store both the current and end iterators for each concatenated
   /// sequence in a tuple of pairs.
@@ -595,6 +595,7 @@ public:
       : IterPairs({std::begin(Ranges), std::end(Ranges)}...) {}
 
   using BaseT::operator++;
+
   concat_iterator &operator++() {
     increment(index_sequence_for<IterTs...>());
     return *this;
@@ -608,6 +609,7 @@ public:
 };
 
 namespace detail {
+
 /// Helper to store a sequence of ranges being concatenated and access them.
 ///
 /// This is designed to facilitate providing actual storage when temporaries
@@ -615,9 +617,9 @@ namespace detail {
 /// based for loops.
 template <typename ValueT, typename... RangeTs> class concat_range {
 public:
-  typedef concat_iterator<ValueT,
-                          decltype(std::begin(std::declval<RangeTs &>()))...>
-      iterator;
+  using iterator =
+      concat_iterator<ValueT,
+                      decltype(std::begin(std::declval<RangeTs &>()))...>;
 
 private:
   std::tuple<RangeTs...> Ranges;
@@ -631,12 +633,14 @@ private:
   }
 
 public:
-  iterator begin() { return begin_impl(index_sequence_for<RangeTs...>{}); }
-  iterator end() { return end_impl(index_sequence_for<RangeTs...>{}); }
   concat_range(RangeTs &&... Ranges)
       : Ranges(std::forward<RangeTs>(Ranges)...) {}
+
+  iterator begin() { return begin_impl(index_sequence_for<RangeTs...>{}); }
+  iterator end() { return end_impl(index_sequence_for<RangeTs...>{}); }
 };
-}
+
+} // end namespace detail
 
 /// Concatenated range across two or more ranges.
 ///
@@ -673,7 +677,7 @@ struct less_second {
 
 /// \brief Represents a compile-time sequence of integers.
 template <class T, T... I> struct integer_sequence {
-  typedef T value_type;
+  using value_type = T;
 
   static constexpr size_t size() { return sizeof...(I); }
 };
@@ -750,7 +754,6 @@ inline int (*get_array_pod_sort_comparator(const T &))
   return array_pod_sort_comparator<T>;
 }
 
-
 /// array_pod_sort - This sorts an array with the specified start and end
 /// extent.  This is just like std::sort, except that it calls qsort instead of
 /// using an inlined template.  qsort is slightly slower than std::sort, but
@@ -1000,6 +1003,7 @@ struct equal {
 /// operands.
 template <typename T> struct deref {
   T func;
+
   // Could be further improved to cope with non-derivable functors and
   // non-binary functors (should be a variadic template member function
   // operator()).
@@ -1012,12 +1016,13 @@ template <typename T> struct deref {
 };
 
 namespace detail {
+
 template <typename R> class enumerator_iter;
 
 template <typename R> struct result_pair {
   friend class enumerator_iter<R>;
 
-  result_pair() : Index(-1) {}
+  result_pair() = default;
   result_pair(std::size_t Index, IterOfRange<R> Iter)
       : Index(Index), Iter(Iter) {}
 
@@ -1032,7 +1037,7 @@ template <typename R> struct result_pair {
   ValueOfRange<R> &value() { return *Iter; }
 
 private:
-  std::size_t Index;
+  std::size_t Index = std::numeric_limits<std::size_t>::max();
   IterOfRange<R> Iter;
 };
 
@@ -1047,7 +1052,7 @@ class enumerator_iter
 
 public:
   explicit enumerator_iter(IterOfRange<R> EndIter)
-    : Result(std::numeric_limits<size_t>::max(), EndIter) { }
+      : Result(std::numeric_limits<size_t>::max(), EndIter) {}
 
   enumerator_iter(std::size_t Index, IterOfRange<R> Iter)
       : Result(Index, Iter) {}
@@ -1085,6 +1090,7 @@ public:
   enumerator_iter<R> begin() {
     return enumerator_iter<R>(0, std::begin(TheRange));
   }
+
   enumerator_iter<R> end() {
     return enumerator_iter<R>(std::end(TheRange));
   }
@@ -1092,7 +1098,8 @@ public:
 private:
   R TheRange;
 };
-}
+
+} // end namespace detail
 
 /// Given an input range, returns a new range whose values are are pair (A,B)
 /// such that A is the 0-based index of the item in the sequence, and B is
@@ -1114,12 +1121,14 @@ template <typename R> detail::enumerator<R> enumerate(R &&TheRange) {
 }
 
 namespace detail {
+
 template <typename F, typename Tuple, std::size_t... I>
 auto apply_tuple_impl(F &&f, Tuple &&t, index_sequence<I...>)
     -> decltype(std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...)) {
   return std::forward<F>(f)(std::get<I>(std::forward<Tuple>(t))...);
 }
-}
+
+} // end namespace detail
 
 /// Given an input tuple (a1, a2, ..., an), pass the arguments of the
 /// tuple variadically to f as if by calling f(a1, a2, ..., an) and
@@ -1135,6 +1144,7 @@ auto apply_tuple(F &&f, Tuple &&t) -> decltype(detail::apply_tuple_impl(
   return detail::apply_tuple_impl(std::forward<F>(f), std::forward<Tuple>(t),
                                   Indices{});
 }
-} // End llvm namespace
 
-#endif
+} // end namespace llvm
+
+#endif // LLVM_ADT_STLEXTRAS_H
diff --git a/include/llvm/ADT/Twine.h b/include/llvm/ADT/Twine.h
index f5f00dcfafe..b60fd098139 100644
--- a/include/llvm/ADT/Twine.h
+++ b/include/llvm/ADT/Twine.h
@@ -1,4 +1,4 @@
-//===-- Twine.h - Fast Temporary String Concatenation -----------*- C++ -*-===//
+//===- Twine.h - Fast Temporary String Concatenation ------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -155,17 +155,19 @@ namespace llvm {
     /// LHS - The prefix in the concatenation, which may be uninitialized for
     /// Null or Empty kinds.
     Child LHS;
+
     /// RHS - The suffix in the concatenation, which may be uninitialized for
     /// Null or Empty kinds.
     Child RHS;
+
     /// LHSKind - The NodeKind of the left hand side, \see getLHSKind().
-    NodeKind LHSKind;
+    NodeKind LHSKind = EmptyKind;
+
     /// RHSKind - The NodeKind of the right hand side, \see getRHSKind().
-    NodeKind RHSKind;
+    NodeKind RHSKind = EmptyKind;
 
     /// Construct a nullary twine; the kind must be NullKind or EmptyKind.
-    explicit Twine(NodeKind Kind)
-      : LHSKind(Kind), RHSKind(EmptyKind) {
+    explicit Twine(NodeKind Kind) : LHSKind(Kind) {
       assert(isNullary() && "Invalid kind!");
     }
 
@@ -252,7 +254,7 @@ namespace llvm {
     /// @{
 
     /// Construct from an empty string.
-    /*implicit*/ Twine() : LHSKind(EmptyKind), RHSKind(EmptyKind) {
+    /*implicit*/ Twine() {
       assert(isValid() && "Invalid twine!");
     }
 
@@ -263,8 +265,7 @@ namespace llvm {
     /// We take care here to optimize "" into the empty twine -- this will be
     /// optimized out for string constants. This allows Twine arguments have
     /// default "" values, without introducing unnecessary string constants.
-    /*implicit*/ Twine(const char *Str)
-      : RHSKind(EmptyKind) {
+    /*implicit*/ Twine(const char *Str) {
       if (Str[0] != '\0') {
         LHS.cString = Str;
         LHSKind = CStringKind;
@@ -275,84 +276,73 @@ namespace llvm {
     }
 
     /// Construct from an std::string.
-    /*implicit*/ Twine(const std::string &Str)
-      : LHSKind(StdStringKind), RHSKind(EmptyKind) {
+    /*implicit*/ Twine(const std::string &Str) : LHSKind(StdStringKind) {
       LHS.stdString = &Str;
       assert(isValid() && "Invalid twine!");
     }
 
     /// Construct from a StringRef.
-    /*implicit*/ Twine(const StringRef &Str)
-      : LHSKind(StringRefKind), RHSKind(EmptyKind) {
+    /*implicit*/ Twine(const StringRef &Str) : LHSKind(StringRefKind) {
       LHS.stringRef = &Str;
       assert(isValid() && "Invalid twine!");
     }
 
     /// Construct from a SmallString.
     /*implicit*/ Twine(const SmallVectorImpl<char> &Str)
-      : LHSKind(SmallStringKind), RHSKind(EmptyKind) {
+        : LHSKind(SmallStringKind) {
       LHS.smallString = &Str;
       assert(isValid() && "Invalid twine!");
     }
 
     /// Construct from a formatv_object_base.
     /*implicit*/ Twine(const formatv_object_base &Fmt)
-        : LHSKind(FormatvObjectKind), RHSKind(EmptyKind) {
+        : LHSKind(FormatvObjectKind) {
       LHS.formatvObject = &Fmt;
       assert(isValid() && "Invalid twine!");
     }
 
     /// Construct from a char.
-    explicit Twine(char Val)
-      : LHSKind(CharKind), RHSKind(EmptyKind) {
+    explicit Twine(char Val) : LHSKind(CharKind) {
       LHS.character = Val;
     }
 
     /// Construct from a signed char.
-    explicit Twine(signed char Val)
-      : LHSKind(CharKind), RHSKind(EmptyKind) {
+    explicit Twine(signed char Val) : LHSKind(CharKind) {
       LHS.character = static_cast<char>(Val);
     }
 
     /// Construct from an unsigned char.
-    explicit Twine(unsigned char Val)
-      : LHSKind(CharKind), RHSKind(EmptyKind) {
+    explicit Twine(unsigned char Val) : LHSKind(CharKind) {
       LHS.character = static_cast<char>(Val);
     }
 
     /// Construct a twine to print \p Val as an unsigned decimal integer.
-    explicit Twine(unsigned Val)
-      : LHSKind(DecUIKind), RHSKind(EmptyKind) {
+    explicit Twine(unsigned Val) : LHSKind(DecUIKind) {
       LHS.decUI = Val;
     }
 
     /// Construct a twine to print \p Val as a signed decimal integer.
-    explicit Twine(int Val)
-      : LHSKind(DecIKind), RHSKind(EmptyKind) {
+    explicit Twine(int Val) : LHSKind(DecIKind) {
       LHS.decI = Val;
     }
 
     /// Construct a twine to print \p Val as an unsigned decimal integer.
-    explicit Twine(const unsigned long &Val)
-      : LHSKind(DecULKind), RHSKind(EmptyKind) {
+    explicit Twine(const unsigned long &Val) : LHSKind(DecULKind) {
       LHS.decUL = &Val;
     }
 
     /// Construct a twine to print \p Val as a signed decimal integer.
-    explicit Twine(const long &Val)
-      : LHSKind(DecLKind), RHSKind(EmptyKind) {
+    explicit Twine(const long &Val) : LHSKind(DecLKind) {
       LHS.decL = &Val;
     }
 
     /// Construct a twine to print \p Val as an unsigned decimal integer.
-    explicit Twine(const unsigned long long &Val)
-      : LHSKind(DecULLKind), RHSKind(EmptyKind) {
+    explicit Twine(const unsigned long long &Val) : LHSKind(DecULLKind) {
       LHS.decULL = &Val;
     }
 
     /// Construct a twine to print \p Val as a signed decimal integer.
-    explicit Twine(const long long &Val)
-      : LHSKind(DecLLKind), RHSKind(EmptyKind) {
+    explicit Twine(const long long &Val) : LHSKind(DecLLKind) {
       LHS.decLL = &Val;
     }