Update prebuilt Clang to r353983e.HEADq10.0

clang 9.0.5 (based on r353983e) from build 5696680.

Bug: http://b/135931688
Bug: http://b/136008926
Test: N/A
Change-Id: I922d17410047d2e2df4625615352c588ee71b203

1 files changed, 184 insertions, 0 deletions

diff --git a/clang-r353983e/include/llvm/ADT/CachedHashString.h b/clang-r353983e/include/llvm/ADT/CachedHashString.h
new file mode 100644
index 00000000..80144fb8
--- /dev/null
+++ b/clang-r353983e/include/llvm/ADT/CachedHashString.h
@@ -0,0 +1,184 @@
+//===- llvm/ADT/CachedHashString.h - Prehashed string/StringRef -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines CachedHashString and CachedHashStringRef.  These are owning
+// and not-owning string types that store their hash in addition to their string
+// data.
+//
+// Unlike std::string, CachedHashString can be used in DenseSet/DenseMap
+// (because, unlike std::string, CachedHashString lets us have empty and
+// tombstone values).
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_CACHED_HASH_STRING_H
+#define LLVM_ADT_CACHED_HASH_STRING_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+/// A container which contains a StringRef plus a precomputed hash.
+class CachedHashStringRef {
+  const char *P;
+  uint32_t Size;
+  uint32_t Hash;
+
+public:
+  // Explicit because hashing a string isn't free.
+  explicit CachedHashStringRef(StringRef S)
+      : CachedHashStringRef(S, DenseMapInfo<StringRef>::getHashValue(S)) {}
+
+  CachedHashStringRef(StringRef S, uint32_t Hash)
+      : P(S.data()), Size(S.size()), Hash(Hash) {
+    assert(S.size() <= std::numeric_limits<uint32_t>::max());
+  }
+
+  StringRef val() const { return StringRef(P, Size); }
+  const char *data() const { return P; }
+  uint32_t size() const { return Size; }
+  uint32_t hash() const { return Hash; }
+};
+
+template <> struct DenseMapInfo<CachedHashStringRef> {
+  static CachedHashStringRef getEmptyKey() {
+    return CachedHashStringRef(DenseMapInfo<StringRef>::getEmptyKey(), 0);
+  }
+  static CachedHashStringRef getTombstoneKey() {
+    return CachedHashStringRef(DenseMapInfo<StringRef>::getTombstoneKey(), 1);
+  }
+  static unsigned getHashValue(const CachedHashStringRef &S) {
+    assert(!isEqual(S, getEmptyKey()) && "Cannot hash the empty key!");
+    assert(!isEqual(S, getTombstoneKey()) && "Cannot hash the tombstone key!");
+    return S.hash();
+  }
+  static bool isEqual(const CachedHashStringRef &LHS,
+                      const CachedHashStringRef &RHS) {
+    return LHS.hash() == RHS.hash() &&
+           DenseMapInfo<StringRef>::isEqual(LHS.val(), RHS.val());
+  }
+};
+
+/// A container which contains a string, which it owns, plus a precomputed hash.
+///
+/// We do not null-terminate the string.
+class CachedHashString {
+  friend struct DenseMapInfo<CachedHashString>;
+
+  char *P;
+  uint32_t Size;
+  uint32_t Hash;
+
+  static char *getEmptyKeyPtr() { return DenseMapInfo<char *>::getEmptyKey(); }
+  static char *getTombstoneKeyPtr() {
+    return DenseMapInfo<char *>::getTombstoneKey();
+  }
+
+  bool isEmptyOrTombstone() const {
+    return P == getEmptyKeyPtr() || P == getTombstoneKeyPtr();
+  }
+
+  struct ConstructEmptyOrTombstoneTy {};
+
+  CachedHashString(ConstructEmptyOrTombstoneTy, char *EmptyOrTombstonePtr)
+      : P(EmptyOrTombstonePtr), Size(0), Hash(0) {
+    assert(isEmptyOrTombstone());
+  }
+
+  // TODO: Use small-string optimization to avoid allocating.
+
+public:
+  explicit CachedHashString(const char *S) : CachedHashString(StringRef(S)) {}
+
+  // Explicit because copying and hashing a string isn't free.
+  explicit CachedHashString(StringRef S)
+      : CachedHashString(S, DenseMapInfo<StringRef>::getHashValue(S)) {}
+
+  CachedHashString(StringRef S, uint32_t Hash)
+      : P(new char[S.size()]), Size(S.size()), Hash(Hash) {
+    memcpy(P, S.data(), S.size());
+  }
+
+  // Ideally this class would not be copyable.  But SetVector requires copyable
+  // keys, and we want this to be usable there.
+  CachedHashString(const CachedHashString &Other)
+      : Size(Other.Size), Hash(Other.Hash) {
+    if (Other.isEmptyOrTombstone()) {
+      P = Other.P;
+    } else {
+      P = new char[Size];
+      memcpy(P, Other.P, Size);
+    }
+  }
+
+  CachedHashString &operator=(CachedHashString Other) {
+    swap(*this, Other);
+    return *this;
+  }
+
+  CachedHashString(CachedHashString &&Other) noexcept
+      : P(Other.P), Size(Other.Size), Hash(Other.Hash) {
+    Other.P = getEmptyKeyPtr();
+  }
+
+  ~CachedHashString() {
+    if (!isEmptyOrTombstone())
+      delete[] P;
+  }
+
+  StringRef val() const { return StringRef(P, Size); }
+  uint32_t size() const { return Size; }
+  uint32_t hash() const { return Hash; }
+
+  operator StringRef() const { return val(); }
+  operator CachedHashStringRef() const {
+    return CachedHashStringRef(val(), Hash);
+  }
+
+  friend void swap(CachedHashString &LHS, CachedHashString &RHS) {
+    using std::swap;
+    swap(LHS.P, RHS.P);
+    swap(LHS.Size, RHS.Size);
+    swap(LHS.Hash, RHS.Hash);
+  }
+};
+
+template <> struct DenseMapInfo<CachedHashString> {
+  static CachedHashString getEmptyKey() {
+    return CachedHashString(CachedHashString::ConstructEmptyOrTombstoneTy(),
+                            CachedHashString::getEmptyKeyPtr());
+  }
+  static CachedHashString getTombstoneKey() {
+    return CachedHashString(CachedHashString::ConstructEmptyOrTombstoneTy(),
+                            CachedHashString::getTombstoneKeyPtr());
+  }
+  static unsigned getHashValue(const CachedHashString &S) {
+    assert(!isEqual(S, getEmptyKey()) && "Cannot hash the empty key!");
+    assert(!isEqual(S, getTombstoneKey()) && "Cannot hash the tombstone key!");
+    return S.hash();
+  }
+  static bool isEqual(const CachedHashString &LHS,
+                      const CachedHashString &RHS) {
+    if (LHS.hash() != RHS.hash())
+      return false;
+    if (LHS.P == CachedHashString::getEmptyKeyPtr())
+      return RHS.P == CachedHashString::getEmptyKeyPtr();
+    if (LHS.P == CachedHashString::getTombstoneKeyPtr())
+      return RHS.P == CachedHashString::getTombstoneKeyPtr();
+
+    // This is safe because if RHS.P is the empty or tombstone key, it will have
+    // length 0, so we'll never dereference its pointer.
+    return LHS.val() == RHS.val();
+  }
+};
+
+} // namespace llvm
+
+#endif