revert r354873 as this breaks lldb builds.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@354875 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 145 insertions, 325 deletions

diff --git a/include/clang/Basic/Attr.td b/include/clang/Basic/Attr.td
index bf226c824d..faad45db35 100644
--- a/include/clang/Basic/Attr.td
+++ b/include/clang/Basic/Attr.td
@@ -2366,7 +2366,7 @@ def NoSanitize : InheritableAttr {
   let Documentation = [NoSanitizeDocs];
   let AdditionalMembers = [{
     SanitizerMask getMask() const {
-      SanitizerMask Mask;
+      SanitizerMask Mask = 0;
       for (auto SanitizerName : sanitizers()) {
         SanitizerMask ParsedMask =
             parseSanitizerValue(SanitizerName, /*AllowGroups=*/true);
diff --git a/include/clang/Basic/Sanitizers.def b/include/clang/Basic/Sanitizers.def
index 98e9aaa5b8..34bd6fc5f0 100644
--- a/include/clang/Basic/Sanitizers.def
+++ b/include/clang/Basic/Sanitizers.def
@@ -177,7 +177,7 @@ SANITIZER("scudo", Scudo)
 
 // Magic group, containing all sanitizers. For example, "-fno-sanitize=all"
 // can be used to disable all the sanitizers.
-SANITIZER_GROUP("all", All, ~SanitizerMask())
+SANITIZER_GROUP("all", All, ~0ULL)
 
 #undef SANITIZER
 #undef SANITIZER_GROUP
diff --git a/include/clang/Basic/Sanitizers.h b/include/clang/Basic/Sanitizers.h
index afbdf63840..f2cfadbee0 100644
--- a/include/clang/Basic/Sanitizers.h
+++ b/include/clang/Basic/Sanitizers.h
@@ -21,167 +21,44 @@
 #include <cstdint>
 
 namespace clang {
-class SanitizerMask;
-}
-
-namespace llvm {
-class hashcode;
-hash_code hash_value(const clang::SanitizerMask &Arg);
-} // namespace llvm
-
-namespace clang {
-
-class SanitizerMask {
-  /// Number of array elements.
-  static constexpr unsigned kNumElem = 2;
-  /// Mask value initialized to 0.
-  uint64_t maskLoToHigh[kNumElem]{};
-  /// Number of bits in a mask.
-  static constexpr unsigned kNumBits = sizeof(decltype(maskLoToHigh)) * 8;
-  /// Number of bits in a mask element.
-  static constexpr unsigned kNumBitElem = sizeof(decltype(maskLoToHigh[0])) * 8;
-
-public:
-  static constexpr bool checkBitPos(const unsigned Pos) {
-    return Pos < kNumBits;
-  }
-
-  /// Create a mask with a bit enabled at position Pos.
-  static SanitizerMask bitPosToMask(const unsigned Pos) {
-    assert(Pos < kNumBits && "Bit position too big.");
-    SanitizerMask mask;
-    mask.maskLoToHigh[Pos / kNumBitElem] = 1ULL << Pos % kNumBitElem;
-    return mask;
-  }
-
-  unsigned countPopulation() const {
-    unsigned total = 0;
-    for (const auto &Val : maskLoToHigh)
-      total += llvm::countPopulation(Val);
-    return total;
-  }
-
-  void flipAllBits() {
-    for (auto &Val : maskLoToHigh)
-      Val = ~Val;
-  }
-
-  bool isPowerOf2() const {
-    return countPopulation() == 1;
-  }
-
-  llvm::hash_code hash_value() const;
-
-  explicit operator bool() const {
-    for (const auto &Val : maskLoToHigh)
-      if (Val)
-        return true;
-    return false;
-  };
-
-  bool operator==(const SanitizerMask &V) const {
-    for (unsigned k = 0; k < kNumElem; k++) {
-      if (maskLoToHigh[k] != V.maskLoToHigh[k])
-        return false;
-    }
-    return true;
-  }
-
-  SanitizerMask &operator&=(const SanitizerMask &RHS) {
-    for (unsigned k = 0; k < kNumElem; k++)
-      maskLoToHigh[k] &= RHS.maskLoToHigh[k];
-    return *this;
-  }
 
-  SanitizerMask &operator|=(const SanitizerMask &RHS) {
-    for (unsigned k = 0; k < kNumElem; k++)
-      maskLoToHigh[k] |= RHS.maskLoToHigh[k];
-    return *this;
-  }
+using SanitizerMask = uint64_t;
 
-  bool operator!() const {
-    for (const auto &Val : maskLoToHigh)
-      if (Val)
-        return false;
-    return true;
-  }
+namespace SanitizerKind {
 
-  bool operator!=(const SanitizerMask &RHS) const { return !((*this) == RHS); }
+// Assign ordinals to possible values of -fsanitize= flag, which we will use as
+// bit positions.
+enum SanitizerOrdinal : uint64_t {
+#define SANITIZER(NAME, ID) SO_##ID,
+#define SANITIZER_GROUP(NAME, ID, ALIAS) SO_##ID##Group,
+#include "clang/Basic/Sanitizers.def"
+  SO_Count
 };
 
-inline SanitizerMask operator~(SanitizerMask v) {
-  v.flipAllBits();
-  return v;
-}
-
-inline SanitizerMask operator&(SanitizerMask a, const SanitizerMask &b) {
-  a &= b;
-  return a;
-}
-
-inline SanitizerMask operator|(SanitizerMask a, const SanitizerMask &b) {
-  a |= b;
-  return a;
-}
-
 // Define the set of sanitizer kinds, as well as the set of sanitizers each
 // sanitizer group expands into.
-// Uses static data member of a class template as recommended in second
-// workaround from n4424 to avoid odr issues.
-// FIXME: Can be marked as constexpr once c++14 can be used in llvm.
-// FIXME: n4424 workaround can be replaced by c++17 inline variable.
-template <typename T = void> struct SanitizerMasks {
-
-  // Assign ordinals to possible values of -fsanitize= flag, which we will use
-  // as bit positions.
-  enum SanitizerOrdinal : uint64_t {
-#define SANITIZER(NAME, ID) SO_##ID,
-#define SANITIZER_GROUP(NAME, ID, ALIAS) SO_##ID##Group,
-#include "clang/Basic/Sanitizers.def"
-    SO_Count
-  };
-
-#define SANITIZER(NAME, ID)                                                    \
-  static const SanitizerMask ID;                                               \
-  static_assert(SanitizerMask::checkBitPos(SO_##ID), "Bit position too big.");
-#define SANITIZER_GROUP(NAME, ID, ALIAS)                                       \
-  static const SanitizerMask ID;                                               \
-  static const SanitizerMask ID##Group;                                        \
-  static_assert(SanitizerMask::checkBitPos(SO_##ID##Group),                    \
-                "Bit position too big.");
+#define SANITIZER(NAME, ID) \
+  const SanitizerMask ID = 1ULL << SO_##ID;
+#define SANITIZER_GROUP(NAME, ID, ALIAS) \
+  const SanitizerMask ID = ALIAS; \
+  const SanitizerMask ID##Group = 1ULL << SO_##ID##Group;
 #include "clang/Basic/Sanitizers.def"
-}; // SanitizerMasks
-
-#define SANITIZER(NAME, ID)                                                    \
-  template <typename T>                                                        \
-  const SanitizerMask SanitizerMasks<T>::ID =                                  \
-      SanitizerMask::bitPosToMask(SO_##ID);
-#define SANITIZER_GROUP(NAME, ID, ALIAS)                                       \
-  template <typename T>                                                        \
-  const SanitizerMask SanitizerMasks<T>::ID = SanitizerMask(ALIAS);            \
-  template <typename T>                                                        \
-  const SanitizerMask SanitizerMasks<T>::ID##Group =                           \
-      SanitizerMask::bitPosToMask(SO_##ID##Group);
-#include "clang/Basic/Sanitizers.def"
-
-// Explicit instantiation here to ensure correct initialization order.
-template struct SanitizerMasks<>;
 
-using SanitizerKind = SanitizerMasks<>;
+} // namespace SanitizerKind
 
 struct SanitizerSet {
   /// Check if a certain (single) sanitizer is enabled.
   bool has(SanitizerMask K) const {
-    assert(K.isPowerOf2() && "Has to be a single sanitizer.");
-    return static_cast<bool>(Mask & K);
+    assert(llvm::isPowerOf2_64(K));
+    return Mask & K;
   }
 
   /// Check if one or more sanitizers are enabled.
-  bool hasOneOf(SanitizerMask K) const { return static_cast<bool>(Mask & K); }
+  bool hasOneOf(SanitizerMask K) const { return Mask & K; }
 
   /// Enable or disable a certain (single) sanitizer.
   void set(SanitizerMask K, bool Value) {
-    assert(K.isPowerOf2() && "Has to be a single sanitizer.");
+    assert(llvm::isPowerOf2_64(K));
     Mask = Value ? (Mask | K) : (Mask & ~K);
   }
 
@@ -189,10 +66,10 @@ struct SanitizerSet {
   void clear(SanitizerMask K = SanitizerKind::All) { Mask &= ~K; }
 
   /// Returns true if no sanitizers are enabled.
-  bool empty() const { return !Mask; }
+  bool empty() const { return Mask == 0; }
 
   /// Bitmask of enabled sanitizers.
-  SanitizerMask Mask;
+  SanitizerMask Mask = 0;
 };
 
 /// Parse a single value from a -fsanitize= or -fno-sanitize= value list.
diff --git a/include/clang/Driver/ToolChain.h b/include/clang/Driver/ToolChain.h
index 014b23843a..e82675d334 100644
--- a/include/clang/Driver/ToolChain.h
+++ b/include/clang/Driver/ToolChain.h
@@ -565,9 +565,7 @@ public:
   virtual SanitizerMask getSupportedSanitizers() const;
 
   /// Return sanitizers which are enabled by default.
-  virtual SanitizerMask getDefaultSanitizers() const {
-    return SanitizerMask();
-  }
+  virtual SanitizerMask getDefaultSanitizers() const { return 0; }
 };
 
 /// Set a ToolChain's effective triple. Reset it when the registration object
diff --git a/lib/Basic/SanitizerSpecialCaseList.cpp b/lib/Basic/SanitizerSpecialCaseList.cpp
index 5fb0f9660b..e042db92b4 100644
--- a/lib/Basic/SanitizerSpecialCaseList.cpp
+++ b/lib/Basic/SanitizerSpecialCaseList.cpp
@@ -36,7 +36,7 @@ SanitizerSpecialCaseList::createOrDie(const std::vector<std::string> &Paths) {
 
 void SanitizerSpecialCaseList::createSanitizerSections() {
   for (auto &S : Sections) {
-    SanitizerMask Mask;
+    SanitizerMask Mask = 0;
 
 #define SANITIZER(NAME, ID)                                                    \
   if (S.SectionMatcher->match(NAME))                                           \
diff --git a/lib/Basic/Sanitizers.cpp b/lib/Basic/Sanitizers.cpp
index 6203c1ac77..dd0fddbdc7 100644
--- a/lib/Basic/Sanitizers.cpp
+++ b/lib/Basic/Sanitizers.cpp
@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Basic/Sanitizers.h"
-#include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/StringSwitch.h"
 
 using namespace clang;
@@ -20,9 +19,9 @@ SanitizerMask clang::parseSanitizerValue(StringRef Value, bool AllowGroups) {
   SanitizerMask ParsedKind = llvm::StringSwitch<SanitizerMask>(Value)
 #define SANITIZER(NAME, ID) .Case(NAME, SanitizerKind::ID)
 #define SANITIZER_GROUP(NAME, ID, ALIAS)                                       \
-  .Case(NAME, AllowGroups ? SanitizerKind::ID##Group : SanitizerMask())
+  .Case(NAME, AllowGroups ? SanitizerKind::ID##Group : 0)
 #include "clang/Basic/Sanitizers.def"
-    .Default(SanitizerMask());
+    .Default(0);
   return ParsedKind;
 }
 
@@ -34,13 +33,3 @@ SanitizerMask clang::expandSanitizerGroups(SanitizerMask Kinds) {
 #include "clang/Basic/Sanitizers.def"
   return Kinds;
 }
-
-llvm::hash_code SanitizerMask::hash_value() const {
-  return llvm::hash_combine_range(&maskLoToHigh[0], &maskLoToHigh[kNumElem]);
-}
-
-namespace llvm {
-hash_code hash_value(const clang::SanitizerMask &Arg) {
-  return Arg.hash_value();
-}
-} // namespace llvm
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 09ba2a0eb7..5ee0378efe 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -2855,13 +2855,16 @@ enum class CheckRecoverableKind {
 }
 
 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
-  assert(Kind.countPopulation() == 1);
-  if (Kind == SanitizerKind::Vptr)
+  assert(llvm::countPopulation(Kind) == 1);
+  switch (Kind) {
+  case SanitizerKind::Vptr:
     return CheckRecoverableKind::AlwaysRecoverable;
-  else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
+  case SanitizerKind::Return:
+  case SanitizerKind::Unreachable:
     return CheckRecoverableKind::Unrecoverable;
-  else
+  default:
     return CheckRecoverableKind::Recoverable;
+  }
 }
 
 namespace {
diff --git a/lib/Driver/SanitizerArgs.cpp b/lib/Driver/SanitizerArgs.cpp
index e84933bea0..0112416a88 100644
--- a/lib/Driver/SanitizerArgs.cpp
+++ b/lib/Driver/SanitizerArgs.cpp
@@ -21,52 +21,33 @@
 #include <memory>
 
 using namespace clang;
+using namespace clang::SanitizerKind;
 using namespace clang::driver;
 using namespace llvm::opt;
 
-static const SanitizerMask NeedsUbsanRt =
-    SanitizerKind::Undefined | SanitizerKind::Integer |
-    SanitizerKind::ImplicitConversion | SanitizerKind::Nullability |
-    SanitizerKind::CFI;
-static const SanitizerMask NeedsUbsanCxxRt =
-    SanitizerKind::Vptr | SanitizerKind::CFI;
-static const SanitizerMask NotAllowedWithTrap = SanitizerKind::Vptr;
-static const SanitizerMask NotAllowedWithMinimalRuntime = SanitizerKind::Vptr;
-static const SanitizerMask RequiresPIE =
-    SanitizerKind::DataFlow | SanitizerKind::HWAddress | SanitizerKind::Scudo;
-static const SanitizerMask NeedsUnwindTables =
-    SanitizerKind::Address | SanitizerKind::HWAddress | SanitizerKind::Thread |
-    SanitizerKind::Memory | SanitizerKind::DataFlow;
-static const SanitizerMask SupportsCoverage =
-    SanitizerKind::Address | SanitizerKind::HWAddress |
-    SanitizerKind::KernelAddress | SanitizerKind::KernelHWAddress |
-    SanitizerKind::Memory | SanitizerKind::KernelMemory | SanitizerKind::Leak |
-    SanitizerKind::Undefined | SanitizerKind::Integer |
-    SanitizerKind::ImplicitConversion | SanitizerKind::Nullability |
-    SanitizerKind::DataFlow | SanitizerKind::Fuzzer |
-    SanitizerKind::FuzzerNoLink;
-static const SanitizerMask RecoverableByDefault =
-    SanitizerKind::Undefined | SanitizerKind::Integer |
-    SanitizerKind::ImplicitConversion | SanitizerKind::Nullability;
-static const SanitizerMask Unrecoverable =
-    SanitizerKind::Unreachable | SanitizerKind::Return;
-static const SanitizerMask AlwaysRecoverable =
-    SanitizerKind::KernelAddress | SanitizerKind::KernelHWAddress;
-static const SanitizerMask LegacyFsanitizeRecoverMask =
-    SanitizerKind::Undefined | SanitizerKind::Integer;
-static const SanitizerMask NeedsLTO = SanitizerKind::CFI;
-static const SanitizerMask TrappingSupported =
-    (SanitizerKind::Undefined & ~SanitizerKind::Vptr) |
-    SanitizerKind::UnsignedIntegerOverflow | SanitizerKind::ImplicitConversion |
-    SanitizerKind::Nullability | SanitizerKind::LocalBounds |
-    SanitizerKind::CFI;
-static const SanitizerMask TrappingDefault = SanitizerKind::CFI;
-static const SanitizerMask CFIClasses =
-    SanitizerKind::CFIVCall | SanitizerKind::CFINVCall |
-    SanitizerKind::CFIMFCall | SanitizerKind::CFIDerivedCast |
-    SanitizerKind::CFIUnrelatedCast;
-static const SanitizerMask CompatibleWithMinimalRuntime =
-    TrappingSupported | SanitizerKind::Scudo | SanitizerKind::ShadowCallStack;
+enum : SanitizerMask {
+  NeedsUbsanRt = Undefined | Integer | ImplicitConversion | Nullability | CFI,
+  NeedsUbsanCxxRt = Vptr | CFI,
+  NotAllowedWithTrap = Vptr,
+  NotAllowedWithMinimalRuntime = Vptr,
+  RequiresPIE = DataFlow | HWAddress | Scudo,
+  NeedsUnwindTables = Address | HWAddress | Thread | Memory | DataFlow,
+  SupportsCoverage = Address | HWAddress | KernelAddress | KernelHWAddress |
+                     Memory | KernelMemory | Leak | Undefined | Integer |
+                     ImplicitConversion | Nullability | DataFlow | Fuzzer |
+                     FuzzerNoLink,
+  RecoverableByDefault = Undefined | Integer | ImplicitConversion | Nullability,
+  Unrecoverable = Unreachable | Return,
+  AlwaysRecoverable = KernelAddress | KernelHWAddress,
+  LegacyFsanitizeRecoverMask = Undefined | Integer,
+  NeedsLTO = CFI,
+  TrappingSupported = (Undefined & ~Vptr) | UnsignedIntegerOverflow |
+                      ImplicitConversion | Nullability | LocalBounds | CFI,
+  TrappingDefault = CFI,
+  CFIClasses =
+      CFIVCall | CFINVCall | CFIMFCall | CFIDerivedCast | CFIUnrelatedCast,
+  CompatibleWithMinimalRuntime = TrappingSupported | Scudo | ShadowCallStack,
+};
 
 enum CoverageFeature {
   CoverageFunc = 1 << 0,
@@ -119,15 +100,13 @@ static void addDefaultBlacklists(const Driver &D, SanitizerMask Kinds,
   struct Blacklist {
     const char *File;
     SanitizerMask Mask;
-  } Blacklists[] = {{"asan_blacklist.txt", SanitizerKind::Address},
-                    {"hwasan_blacklist.txt", SanitizerKind::HWAddress},
-                    {"msan_blacklist.txt", SanitizerKind::Memory},
-                    {"tsan_blacklist.txt", SanitizerKind::Thread},
-                    {"dfsan_abilist.txt", SanitizerKind::DataFlow},
-                    {"cfi_blacklist.txt", SanitizerKind::CFI},
-                    {"ubsan_blacklist.txt", SanitizerKind::Undefined |
-                                                SanitizerKind::Integer |
-                                                SanitizerKind::Nullability}};
+  } Blacklists[] = {{"asan_blacklist.txt", Address},
+                    {"hwasan_blacklist.txt", HWAddress},
+                    {"msan_blacklist.txt", Memory},
+                    {"tsan_blacklist.txt", Thread},
+                    {"dfsan_abilist.txt", DataFlow},
+                    {"cfi_blacklist.txt", CFI},
+                    {"ubsan_blacklist.txt", Undefined | Integer | Nullability}};
 
   for (auto BL : Blacklists) {
     if (!(Kinds & BL.Mask))
@@ -137,7 +116,7 @@ static void addDefaultBlacklists(const Driver &D, SanitizerMask Kinds,
     llvm::sys::path::append(Path, "share", BL.File);
     if (llvm::sys::fs::exists(Path))
       BlacklistFiles.push_back(Path.str());
-    else if (BL.Mask == SanitizerKind::CFI)
+    else if (BL.Mask == CFI)
       // If cfi_blacklist.txt cannot be found in the resource dir, driver
       // should fail.
       D.Diag(clang::diag::err_drv_no_such_file) << Path;
@@ -157,10 +136,10 @@ static SanitizerMask setGroupBits(SanitizerMask Kinds) {
 
 static SanitizerMask parseSanitizeTrapArgs(const Driver &D,
                                            const llvm::opt::ArgList &Args) {
-  SanitizerMask TrapRemove;     // During the loop below, the accumulated set of
+  SanitizerMask TrapRemove = 0; // During the loop below, the accumulated set of
                                 // sanitizers disabled by the current sanitizer
                                 // argument or any argument after it.
-  SanitizerMask TrappingKinds;
+  SanitizerMask TrappingKinds = 0;
   SanitizerMask TrappingSupportedWithGroups = setGroupBits(TrappingSupported);
 
   for (ArgList::const_reverse_iterator I = Args.rbegin(), E = Args.rend();
@@ -184,12 +163,11 @@ static SanitizerMask parseSanitizeTrapArgs(const Driver &D,
                    options::OPT_fsanitize_undefined_trap_on_error)) {
       Arg->claim();
       TrappingKinds |=
-          expandSanitizerGroups(SanitizerKind::UndefinedGroup & ~TrapRemove) &
-          ~TrapRemove;
+          expandSanitizerGroups(UndefinedGroup & ~TrapRemove) & ~TrapRemove;
     } else if (Arg->getOption().matches(
                    options::OPT_fno_sanitize_undefined_trap_on_error)) {
       Arg->claim();
-      TrapRemove |= expandSanitizerGroups(SanitizerKind::UndefinedGroup);
+      TrapRemove |= expandSanitizerGroups(UndefinedGroup);
     }
   }
 
@@ -211,13 +189,13 @@ bool SanitizerArgs::needsUbsanRt() const {
 }
 
 bool SanitizerArgs::needsCfiRt() const {
-  return !(Sanitizers.Mask & SanitizerKind::CFI & ~TrapSanitizers.Mask) &&
-         CfiCrossDso && !ImplicitCfiRuntime;
+  return !(Sanitizers.Mask & CFI & ~TrapSanitizers.Mask) && CfiCrossDso &&
+         !ImplicitCfiRuntime;
 }
 
 bool SanitizerArgs::needsCfiDiagRt() const {
-  return (Sanitizers.Mask & SanitizerKind::CFI & ~TrapSanitizers.Mask) &&
-         CfiCrossDso && !ImplicitCfiRuntime;
+  return (Sanitizers.Mask & CFI & ~TrapSanitizers.Mask) && CfiCrossDso &&
+         !ImplicitCfiRuntime;
 }
 
 bool SanitizerArgs::requiresPIE() const {
@@ -225,26 +203,24 @@ bool SanitizerArgs::requiresPIE() const {
 }
 
 bool SanitizerArgs::needsUnwindTables() const {
-  return static_cast<bool>(Sanitizers.Mask & NeedsUnwindTables);
+  return Sanitizers.Mask & NeedsUnwindTables;
 }
 
-bool SanitizerArgs::needsLTO() const {
-  return static_cast<bool>(Sanitizers.Mask & NeedsLTO);
-}
+bool SanitizerArgs::needsLTO() const { return Sanitizers.Mask & NeedsLTO; }
 
 SanitizerArgs::SanitizerArgs(const ToolChain &TC,
                              const llvm::opt::ArgList &Args) {
-  SanitizerMask AllRemove;      // During the loop below, the accumulated set of
+  SanitizerMask AllRemove = 0;  // During the loop below, the accumulated set of
                                 // sanitizers disabled by the current sanitizer
                                 // argument or any argument after it.
-  SanitizerMask AllAddedKinds;      // Mask of all sanitizers ever enabled by
+  SanitizerMask AllAddedKinds = 0;  // Mask of all sanitizers ever enabled by
                                     // -fsanitize= flags (directly or via group
                                     // expansion), some of which may be disabled
                                     // later. Used to carefully prune
                                     // unused-argument diagnostics.
-  SanitizerMask DiagnosedKinds;      // All Kinds we have diagnosed up to now.
+  SanitizerMask DiagnosedKinds = 0;  // All Kinds we have diagnosed up to now.
                                      // Used to deduplicate diagnostics.
-  SanitizerMask Kinds;
+  SanitizerMask Kinds = 0;
   const SanitizerMask Supported = setGroupBits(TC.getSupportedSanitizers());
 
   CfiCrossDso = Args.hasFlag(options::OPT_fsanitize_cfi_cross_dso,
@@ -319,12 +295,12 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
       //   identifiers.
       // Fixing both of those may require changes to the cross-DSO CFI
       // interface.
-      if (CfiCrossDso && (Add & SanitizerKind::CFIMFCall & ~DiagnosedKinds)) {
+      if (CfiCrossDso && (Add & CFIMFCall & ~DiagnosedKinds)) {
         D.Diag(diag::err_drv_argument_not_allowed_with)
             << "-fsanitize=cfi-mfcall"
             << "-fsanitize-cfi-cross-dso";
-        Add &= ~SanitizerKind::CFIMFCall;
-        DiagnosedKinds |= SanitizerKind::CFIMFCall;
+        Add &= ~CFIMFCall;
+        DiagnosedKinds |= CFIMFCall;
       }
 
       if (SanitizerMask KindsToDiagnose = Add & ~Supported & ~DiagnosedKinds) {
@@ -338,7 +314,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
       // Test for -fno-rtti + explicit -fsanitizer=vptr before expanding groups
       // so we don't error out if -fno-rtti and -fsanitize=undefined were
       // passed.
-      if ((Add & SanitizerKind::Vptr) && (RTTIMode == ToolChain::RM_Disabled)) {
+      if ((Add & Vptr) && (RTTIMode == ToolChain::RM_Disabled)) {
         if (const llvm::opt::Arg *NoRTTIArg = TC.getRTTIArg()) {
           assert(NoRTTIArg->getOption().matches(options::OPT_fno_rtti) &&
                   "RTTI disabled without -fno-rtti option?");
@@ -353,7 +329,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
         }
 
         // Take out the Vptr sanitizer from the enabled sanitizers
-        AllRemove |= SanitizerKind::Vptr;
+        AllRemove |= Vptr;
       }
 
       Add = expandSanitizerGroups(Add);
@@ -366,14 +342,14 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
         Add &= ~NotAllowedWithMinimalRuntime;
       }
       if (CfiCrossDso)
-        Add &= ~SanitizerKind::CFIMFCall;
+        Add &= ~CFIMFCall;
       Add &= Supported;
 
-      if (Add & SanitizerKind::Fuzzer)
-        Add |= SanitizerKind::FuzzerNoLink;
+      if (Add & Fuzzer)
+        Add |= FuzzerNoLink;
 
       // Enable coverage if the fuzzing flag is set.
-      if (Add & SanitizerKind::FuzzerNoLink) {
+      if (Add & FuzzerNoLink) {
         CoverageFeatures |= CoverageInline8bitCounters | CoverageIndirCall |
                             CoverageTraceCmp | CoveragePCTable;
         // Due to TLS differences, stack depth tracking is only enabled on Linux
@@ -390,42 +366,23 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   }
 
   std::pair<SanitizerMask, SanitizerMask> IncompatibleGroups[] = {
-      std::make_pair(SanitizerKind::Address,
-                     SanitizerKind::Thread | SanitizerKind::Memory),
-      std::make_pair(SanitizerKind::Thread, SanitizerKind::Memory),
-      std::make_pair(SanitizerKind::Leak,
-                     SanitizerKind::Thread | SanitizerKind::Memory),
-      std::make_pair(SanitizerKind::KernelAddress,
-                     SanitizerKind::Address | SanitizerKind::Leak |
-                         SanitizerKind::Thread | SanitizerKind::Memory),
-      std::make_pair(SanitizerKind::HWAddress,
-                     SanitizerKind::Address | SanitizerKind::Thread |
-                         SanitizerKind::Memory | SanitizerKind::KernelAddress),
-      std::make_pair(SanitizerKind::Efficiency,
-                     SanitizerKind::Address | SanitizerKind::HWAddress |
-                         SanitizerKind::Leak | SanitizerKind::Thread |
-                         SanitizerKind::Memory | SanitizerKind::KernelAddress),
-      std::make_pair(SanitizerKind::Scudo,
-                     SanitizerKind::Address | SanitizerKind::HWAddress |
-                         SanitizerKind::Leak | SanitizerKind::Thread |
-                         SanitizerKind::Memory | SanitizerKind::KernelAddress |
-                         SanitizerKind::Efficiency),
-      std::make_pair(SanitizerKind::SafeStack,
-                     SanitizerKind::Address | SanitizerKind::HWAddress |
-                         SanitizerKind::Leak | SanitizerKind::Thread |
-                         SanitizerKind::Memory | SanitizerKind::KernelAddress |
-                         SanitizerKind::Efficiency),
-      std::make_pair(SanitizerKind::KernelHWAddress,
-                     SanitizerKind::Address | SanitizerKind::HWAddress |
-                         SanitizerKind::Leak | SanitizerKind::Thread |
-                         SanitizerKind::Memory | SanitizerKind::KernelAddress |
-                         SanitizerKind::Efficiency | SanitizerKind::SafeStack),
-      std::make_pair(SanitizerKind::KernelMemory,
-                     SanitizerKind::Address | SanitizerKind::HWAddress |
-                         SanitizerKind::Leak | SanitizerKind::Thread |
-                         SanitizerKind::Memory | SanitizerKind::KernelAddress |
-                         SanitizerKind::Efficiency | SanitizerKind::Scudo |
-                         SanitizerKind::SafeStack)};
+      std::make_pair(Address, Thread | Memory),
+      std::make_pair(Thread, Memory),
+      std::make_pair(Leak, Thread | Memory),
+      std::make_pair(KernelAddress, Address | Leak | Thread | Memory),
+      std::make_pair(HWAddress, Address | Thread | Memory | KernelAddress),
+      std::make_pair(Efficiency, Address | HWAddress | Leak | Thread | Memory |
+                                     KernelAddress),
+      std::make_pair(Scudo, Address | HWAddress | Leak | Thread | Memory |
+                                KernelAddress | Efficiency),
+      std::make_pair(SafeStack, Address | HWAddress | Leak | Thread | Memory |
+                                    KernelAddress | Efficiency),
+      std::make_pair(KernelHWAddress, Address | HWAddress | Leak | Thread |
+                                          Memory | KernelAddress | Efficiency |
+                                          SafeStack),
+      std::make_pair(KernelMemory, Address | HWAddress | Leak | Thread |
+                                       Memory | KernelAddress | Efficiency |
+                                       Scudo | SafeStack)};
   // Enable toolchain specific default sanitizers if not explicitly disabled.
   SanitizerMask Default = TC.getDefaultSanitizers() & ~AllRemove;
 
@@ -441,8 +398,8 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
 
   // We disable the vptr sanitizer if it was enabled by group expansion but RTTI
   // is disabled.
-  if ((Kinds & SanitizerKind::Vptr) && (RTTIMode == ToolChain::RM_Disabled)) {
-    Kinds &= ~SanitizerKind::Vptr;
+  if ((Kinds & Vptr) && (RTTIMode == ToolChain::RM_Disabled)) {
+    Kinds &= ~Vptr;
   }
 
   // Check that LTO is enabled if we need it.
@@ -451,12 +408,12 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
         << lastArgumentForMask(D, Args, Kinds & NeedsLTO) << "-flto";
   }
 
-  if ((Kinds & SanitizerKind::ShadowCallStack) &&
+  if ((Kinds & ShadowCallStack) &&
       TC.getTriple().getArch() == llvm::Triple::aarch64 &&
       !llvm::AArch64::isX18ReservedByDefault(TC.getTriple()) &&
       !Args.hasArg(options::OPT_ffixed_x18)) {
     D.Diag(diag::err_drv_argument_only_allowed_with)
-        << lastArgumentForMask(D, Args, Kinds & SanitizerKind::ShadowCallStack)
+        << lastArgumentForMask(D, Args, Kinds & ShadowCallStack)
         << "-ffixed-x18";
   }
 
@@ -464,12 +421,12 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   // c++abi-specific  parts of UBSan runtime, and they are not provided by the
   // toolchain. We don't have a good way to check the latter, so we just
   // check if the toolchan supports vptr.
-  if (~Supported & SanitizerKind::Vptr) {
+  if (~Supported & Vptr) {
     SanitizerMask KindsToDiagnose = Kinds & ~TrappingKinds & NeedsUbsanCxxRt;
     // The runtime library supports the Microsoft C++ ABI, but only well enough
     // for CFI. FIXME: Remove this once we support vptr on Windows.
     if (TC.getTriple().isOSWindows())
-      KindsToDiagnose &= ~SanitizerKind::CFI;
+      KindsToDiagnose &= ~CFI;
     if (KindsToDiagnose) {
       SanitizerSet S;
       S.Mask = KindsToDiagnose;
@@ -498,8 +455,8 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
 
   // Parse -f(no-)?sanitize-recover flags.
   SanitizerMask RecoverableKinds = RecoverableByDefault | AlwaysRecoverable;
-  SanitizerMask DiagnosedUnrecoverableKinds;
-  SanitizerMask DiagnosedAlwaysRecoverableKinds;
+  SanitizerMask DiagnosedUnrecoverableKinds = 0;
+  SanitizerMask DiagnosedAlwaysRecoverableKinds = 0;
   for (const auto *Arg : Args) {
     const char *DeprecatedReplacement = nullptr;
     if (Arg->getOption().matches(options::OPT_fsanitize_recover)) {
@@ -582,7 +539,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   }
 
   // Parse -f[no-]sanitize-memory-track-origins[=level] options.
-  if (AllAddedKinds & SanitizerKind::Memory) {
+  if (AllAddedKinds & Memory) {
     if (Arg *A =
             Args.getLastArg(options::OPT_fsanitize_memory_track_origins_EQ,
                             options::OPT_fsanitize_memory_track_origins,
@@ -610,19 +567,19 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     MsanUseAfterDtor = false;
   }
 
-  if (AllAddedKinds & SanitizerKind::Thread) {
-    TsanMemoryAccess = Args.hasFlag(
-        options::OPT_fsanitize_thread_memory_access,
-        options::OPT_fno_sanitize_thread_memory_access, TsanMemoryAccess);
-    TsanFuncEntryExit = Args.hasFlag(
-        options::OPT_fsanitize_thread_func_entry_exit,
-        options::OPT_fno_sanitize_thread_func_entry_exit, TsanFuncEntryExit);
-    TsanAtomics =
-        Args.hasFlag(options::OPT_fsanitize_thread_atomics,
-                     options::OPT_fno_sanitize_thread_atomics, TsanAtomics);
+  if (AllAddedKinds & Thread) {
+    TsanMemoryAccess = Args.hasFlag(options::OPT_fsanitize_thread_memory_access,
+                                    options::OPT_fno_sanitize_thread_memory_access,
+                                    TsanMemoryAccess);
+    TsanFuncEntryExit = Args.hasFlag(options::OPT_fsanitize_thread_func_entry_exit,
+                                     options::OPT_fno_sanitize_thread_func_entry_exit,
+                                     TsanFuncEntryExit);
+    TsanAtomics = Args.hasFlag(options::OPT_fsanitize_thread_atomics,
+                               options::OPT_fno_sanitize_thread_atomics,
+                               TsanAtomics);
   }
 
-  if (AllAddedKinds & SanitizerKind::CFI) {
+  if (AllAddedKinds & CFI) {
     // Without PIE, external function address may resolve to a PLT record, which
     // can not be verified by the target module.
     NeedPIE |= CfiCrossDso;
@@ -646,7 +603,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
           << "-fsanitize-minimal-runtime"
           << lastArgumentForMask(D, Args, IncompatibleMask);
 
-    SanitizerMask NonTrappingCfi = Kinds & SanitizerKind::CFI & ~TrappingKinds;
+    SanitizerMask NonTrappingCfi = Kinds & CFI & ~TrappingKinds;
     if (NonTrappingCfi)
       D.Diag(clang::diag::err_drv_argument_only_allowed_with)
           << "fsanitize-minimal-runtime"
@@ -734,7 +691,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
 
   ImplicitCfiRuntime = TC.getTriple().isAndroid();
 
-  if (AllAddedKinds & SanitizerKind::Address) {
+  if (AllAddedKinds & Address) {
     NeedPIE |= TC.getTriple().isOSFuchsia();
     if (Arg *A =
             Args.getLastArg(options::OPT_fsanitize_address_field_padding)) {
@@ -756,7 +713,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
       case options::OPT__SLASH_LDd:
         D.Diag(clang::diag::err_drv_argument_not_allowed_with)
             << WindowsDebugRTArg->getAsString(Args)
-            << lastArgumentForMask(D, Args, SanitizerKind::Address);
+            << lastArgumentForMask(D, Args, Address);
         D.Diag(clang::diag::note_drv_address_sanitizer_debug_runtime);
       }
     }
@@ -785,7 +742,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     AsanUseAfterScope = false;
   }
 
-  if (AllAddedKinds & SanitizerKind::HWAddress) {
+  if (AllAddedKinds & HWAddress) {
     if (Arg *HwasanAbiArg =
             Args.getLastArg(options::OPT_fsanitize_hwaddress_abi_EQ)) {
       HwasanAbi = HwasanAbiArg->getValue();
@@ -797,7 +754,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     }
   }
 
-  if (AllAddedKinds & SanitizerKind::SafeStack) {
+  if (AllAddedKinds & SafeStack) {
     // SafeStack runtime is built into the system on Fuchsia.
     SafeStackRuntime = !TC.getTriple().isOSFuchsia();
   }
@@ -817,7 +774,7 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
 static std::string toString(const clang::SanitizerSet &Sanitizers) {
   std::string Res;
 #define SANITIZER(NAME, ID)                                                    \
-  if (Sanitizers.has(SanitizerKind::ID)) {                                     \
+  if (Sanitizers.has(ID)) {                                                    \
     if (!Res.empty())                                                          \
       Res += ",";                                                              \
     Res += NAME;                                                               \
@@ -979,8 +936,7 @@ void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
   // https://github.com/google/sanitizers/issues/373
   // We can't make this conditional on -fsanitize=leak, as that flag shouldn't
   // affect compilation.
-  if (Sanitizers.has(SanitizerKind::Memory) ||
-      Sanitizers.has(SanitizerKind::Address))
+  if (Sanitizers.has(Memory) || Sanitizers.has(Address))
     CmdArgs.push_back("-fno-assume-sane-operator-new");
 
   // Require -fvisibility= flag on non-Windows when compiling if vptr CFI is
@@ -1003,18 +959,18 @@ SanitizerMask parseArgValues(const Driver &D, const llvm::opt::Arg *A,
           A->getOption().matches(options::OPT_fsanitize_trap_EQ) ||
           A->getOption().matches(options::OPT_fno_sanitize_trap_EQ)) &&
          "Invalid argument in parseArgValues!");
-  SanitizerMask Kinds;
+  SanitizerMask Kinds = 0;
   for (int i = 0, n = A->getNumValues(); i != n; ++i) {
     const char *Value = A->getValue(i);
     SanitizerMask Kind;
     // Special case: don't accept -fsanitize=all.
     if (A->getOption().matches(options::OPT_fsanitize_EQ) &&
         0 == strcmp("all", Value))
-      Kind = SanitizerMask();
+      Kind = 0;
     // Similarly, don't accept -fsanitize=efficiency-all.
     else if (A->getOption().matches(options::OPT_fsanitize_EQ) &&
         0 == strcmp("efficiency-all", Value))
-      Kind = SanitizerMask();
+      Kind = 0;
     else
       Kind = parseSanitizerValue(Value, /*AllowGroups=*/true);
 
diff --git a/lib/Driver/ToolChain.cpp b/lib/Driver/ToolChain.cpp
index 289d47d394..fcf373e9f7 100644
--- a/lib/Driver/ToolChain.cpp
+++ b/lib/Driver/ToolChain.cpp
@@ -818,23 +818,21 @@ SanitizerMask ToolChain::getSupportedSanitizers() const {
   // Return sanitizers which don't require runtime support and are not
   // platform dependent.
 
-  SanitizerMask Res = (SanitizerKind::Undefined & ~SanitizerKind::Vptr &
-                       ~SanitizerKind::Function) |
-                      (SanitizerKind::CFI & ~SanitizerKind::CFIICall) |
-                      SanitizerKind::CFICastStrict |
-                      SanitizerKind::UnsignedIntegerOverflow |
-                      SanitizerKind::ImplicitConversion |
-                      SanitizerKind::Nullability | SanitizerKind::LocalBounds;
+  using namespace SanitizerKind;
+
+  SanitizerMask Res = (Undefined & ~Vptr & ~Function) | (CFI & ~CFIICall) |
+                      CFICastStrict | UnsignedIntegerOverflow |
+                      ImplicitConversion | Nullability | LocalBounds;
   if (getTriple().getArch() == llvm::Triple::x86 ||
       getTriple().getArch() == llvm::Triple::x86_64 ||
       getTriple().getArch() == llvm::Triple::arm ||
       getTriple().getArch() == llvm::Triple::aarch64 ||
       getTriple().getArch() == llvm::Triple::wasm32 ||
       getTriple().getArch() == llvm::Triple::wasm64)
-    Res |= SanitizerKind::CFIICall;
+    Res |= CFIICall;
   if (getTriple().getArch() == llvm::Triple::x86_64 ||
       getTriple().getArch() == llvm::Triple::aarch64)
-    Res |= SanitizerKind::ShadowCallStack;
+    Res |= ShadowCallStack;
   return Res;
 }
 
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 4d061c6b6c..b1a886241a 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -551,7 +551,7 @@ static void parseSanitizerKinds(StringRef FlagName,
                                 DiagnosticsEngine &Diags, SanitizerSet &S) {
   for (const auto &Sanitizer : Sanitizers) {
     SanitizerMask K = parseSanitizerValue(Sanitizer, /*AllowGroups=*/false);
-    if (K == SanitizerMask())
+    if (K == 0)
       Diags.Report(diag::err_drv_invalid_value) << FlagName << Sanitizer;
     else
       S.set(K, true);
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index d312936ebc..bf11ae98bc 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -6211,8 +6211,7 @@ static void handleNoSanitizeAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     if (!S.checkStringLiteralArgumentAttr(AL, I, SanitizerName, &LiteralLoc))
       return;
 
-    if (parseSanitizerValue(SanitizerName, /*AllowGroups=*/true) ==
-        SanitizerMask())
+    if (parseSanitizerValue(SanitizerName, /*AllowGroups=*/true) == 0)
       S.Diag(LiteralLoc, diag::warn_unknown_sanitizer_ignored) << SanitizerName;
     else if (isGlobalVar(D) && SanitizerName != "address")
       S.Diag(D->getLocation(), diag::err_attribute_wrong_decl_type)