vendor/clang/clang-release_60-r325330

32 files changed, 412 insertions, 124 deletions

diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index c5e037d0cd9d..be33f15cb229 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -132,6 +132,11 @@ New Compiler Flags
   difference between the ``-std=c17`` and ``-std=c11`` language modes is the
   value of the ``__STDC_VERSION__`` macro, as C17 is a bug fix release.
 
+- Added the ``-fexperimental-isel`` and ``-fno-experimental-isel`` flags to
+  enable/disable the new GlobalISel instruction selection framework. This
+  feature is enabled by default for AArch64 at the ``-O0`` optimization level.
+  Support for other targets or optimization levels is currently incomplete.
+
 Deprecated Compiler Flags
 -------------------------
 
diff --git a/include/clang/AST/DeclBase.h b/include/clang/AST/DeclBase.h
index f93c9f0b9aaa..15de482a8619 100644
--- a/include/clang/AST/DeclBase.h
+++ b/include/clang/AST/DeclBase.h
@@ -836,6 +836,10 @@ public:
 
   void setLexicalDeclContext(DeclContext *DC);
 
+  /// Determine whether this declaration is a templated entity (whether it is
+  // within the scope of a template parameter).
+  bool isTemplated() const;
+
   /// isDefinedOutsideFunctionOrMethod - This predicate returns true if this
   /// scoped decl is defined outside the current function or method.  This is
   /// roughly global variables and functions, but also handles enums (which
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 3dc961d4f12b..c73ae9efe170 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2145,7 +2145,7 @@ static bool unionHasUniqueObjectRepresentations(const ASTContext &Context,
     if (FieldSize != UnionSize)
       return false;
   }
-  return true;
+  return !RD->field_empty();
 }
 
 static bool isStructEmpty(QualType Ty) {
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 2cdcdae9ab02..d427c79c44ab 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -236,10 +236,23 @@ TemplateDecl *Decl::getDescribedTemplate() const {
     return RD->getDescribedClassTemplate();
   else if (auto *VD = dyn_cast<VarDecl>(this))
     return VD->getDescribedVarTemplate();
+  else if (auto *AD = dyn_cast<TypeAliasDecl>(this))
+    return AD->getDescribedAliasTemplate();
 
   return nullptr;
 }
 
+bool Decl::isTemplated() const {
+  // A declaration is dependent if it is a template or a template pattern, or
+  // is within (lexcially for a friend, semantically otherwise) a dependent
+  // context.
+  // FIXME: Should local extern declarations be treated like friends?
+  if (auto *AsDC = dyn_cast<DeclContext>(this))
+    return AsDC->isDependentContext();
+  auto *DC = getFriendObjectKind() ? getLexicalDeclContext() : getDeclContext();
+  return DC->isDependentContext() || isTemplateDecl() || getDescribedTemplate();
+}
+
 const DeclContext *Decl::getParentFunctionOrMethod() const {
   for (const DeclContext *DC = getDeclContext();
        DC && !DC->isTranslationUnit() && !DC->isNamespace(); 
diff --git a/lib/AST/MicrosoftMangle.cpp b/lib/AST/MicrosoftMangle.cpp
index 0c55c1a92287..b4e7a82eb000 100644
--- a/lib/AST/MicrosoftMangle.cpp
+++ b/lib/AST/MicrosoftMangle.cpp
@@ -950,11 +950,10 @@ void MicrosoftCXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
   }
 }
 
+// <postfix> ::= <unqualified-name> [<postfix>]
+//           ::= <substitution> [<postfix>]
 void MicrosoftCXXNameMangler::mangleNestedName(const NamedDecl *ND) {
-  // <postfix> ::= <unqualified-name> [<postfix>]
-  //           ::= <substitution> [<postfix>]
   const DeclContext *DC = getEffectiveDeclContext(ND);
-
   while (!DC->isTranslationUnit()) {
     if (isa<TagDecl>(ND) || isa<VarDecl>(ND)) {
       unsigned Disc;
@@ -2140,6 +2139,7 @@ void MicrosoftCXXNameMangler::mangleCallingConvention(CallingConv CC) {
     case CC_X86StdCall: Out << 'G'; break;
     case CC_X86FastCall: Out << 'I'; break;
     case CC_X86VectorCall: Out << 'Q'; break;
+    case CC_Swift: Out << 'S'; break;
     case CC_X86RegCall: Out << 'w'; break;
   }
 }
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index df33fc3e8200..2172486682cf 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -4000,18 +4000,13 @@ void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
 /// EmitTopLevelDecl - Emit code for a single top level declaration.
 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
   // Ignore dependent declarations.
-  if (D->getDeclContext() && D->getDeclContext()->isDependentContext())
+  if (D->isTemplated())
     return;
 
   switch (D->getKind()) {
   case Decl::CXXConversion:
   case Decl::CXXMethod:
   case Decl::Function:
-    // Skip function templates
-    if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
-        cast<FunctionDecl>(D)->isLateTemplateParsed())
-      return;
-
     EmitGlobal(cast<FunctionDecl>(D));
     // Always provide some coverage mapping
     // even for the functions that aren't emitted.
@@ -4024,10 +4019,6 @@ void CodeGenModule::EmitTopLevelDecl(Decl *D) {
 
   case Decl::Var:
   case Decl::Decomposition:
-    // Skip variable templates
-    if (cast<VarDecl>(D)->getDescribedVarTemplate())
-      return;
-    LLVM_FALLTHROUGH;
   case Decl::VarTemplateSpecialization:
     EmitGlobal(cast<VarDecl>(D));
     if (auto *DD = dyn_cast<DecompositionDecl>(D))
@@ -4086,16 +4077,9 @@ void CodeGenModule::EmitTopLevelDecl(Decl *D) {
       DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
     return;
   case Decl::CXXConstructor:
-    // Skip function templates
-    if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
-        cast<FunctionDecl>(D)->isLateTemplateParsed())
-      return;
-
     getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
     break;
   case Decl::CXXDestructor:
-    if (cast<FunctionDecl>(D)->isLateTemplateParsed())
-      return;
     getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
     break;
 
diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index c375b82ea936..a3c2766dbb49 100644
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2761,6 +2761,11 @@ static bool ShouldUseExternalRTTIDescriptor(CodeGenModule &CGM,
     // N.B. We must always emit the RTTI data ourselves if there exists a key
     // function.
     bool IsDLLImport = RD->hasAttr<DLLImportAttr>();
+
+    // Don't import the RTTI but emit it locally.
+    if (CGM.getTriple().isWindowsGNUEnvironment() && IsDLLImport)
+      return false;
+
     if (CGM.getVTables().isVTableExternal(RD))
       return IsDLLImport && !CGM.getTriple().isWindowsItaniumEnvironment()
                  ? false
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index 4b8006428f8f..abd633280b9d 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -3543,7 +3543,17 @@ ABIArgInfo X86_64ABIInfo::classifyRegCallStructType(QualType Ty,
 
 void X86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
 
-  bool IsRegCall = FI.getCallingConvention() == llvm::CallingConv::X86_RegCall;
+  const unsigned CallingConv = FI.getCallingConvention();
+  // It is possible to force Win64 calling convention on any x86_64 target by
+  // using __attribute__((ms_abi)). In such case to correctly emit Win64
+  // compatible code delegate this call to WinX86_64ABIInfo::computeInfo.
+  if (CallingConv == llvm::CallingConv::Win64) {
+    WinX86_64ABIInfo Win64ABIInfo(CGT);
+    Win64ABIInfo.computeInfo(FI);
+    return;
+  }
+
+  bool IsRegCall = CallingConv == llvm::CallingConv::X86_RegCall;
 
   // Keep track of the number of assigned registers.
   unsigned FreeIntRegs = IsRegCall ? 11 : 6;
diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index 298c72b002f8..079b330f3a7d 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -1723,15 +1723,18 @@ void TokenAnnotator::setCommentLineLevels(
       }
     }
 
-    if (NextNonCommentLine && CommentLine) {
-      // If the comment is currently aligned with the line immediately following
-      // it, that's probably intentional and we should keep it.
-      bool AlignedWithNextLine =
-          NextNonCommentLine->First->NewlinesBefore <= 1 &&
-          NextNonCommentLine->First->OriginalColumn ==
-              (*I)->First->OriginalColumn;
-      if (AlignedWithNextLine)
-        (*I)->Level = NextNonCommentLine->Level;
+    // If the comment is currently aligned with the line immediately following
+    // it, that's probably intentional and we should keep it.
+    if (NextNonCommentLine && CommentLine &&
+        NextNonCommentLine->First->NewlinesBefore <= 1 &&
+        NextNonCommentLine->First->OriginalColumn ==
+            (*I)->First->OriginalColumn) {
+      // Align comments for preprocessor lines with the # in column 0.
+      // Otherwise, align with the next line.
+      (*I)->Level = (NextNonCommentLine->Type == LT_PreprocessorDirective ||
+                     NextNonCommentLine->Type == LT_ImportStatement)
+                        ? 0
+                        : NextNonCommentLine->Level;
     } else {
       NextNonCommentLine = (*I)->First->isNot(tok::r_brace) ? (*I) : nullptr;
     }
diff --git a/lib/Format/UnwrappedLineParser.cpp b/lib/Format/UnwrappedLineParser.cpp
index b8608dcac9c7..34d4ce28aad1 100644
--- a/lib/Format/UnwrappedLineParser.cpp
+++ b/lib/Format/UnwrappedLineParser.cpp
@@ -234,14 +234,17 @@ UnwrappedLineParser::UnwrappedLineParser(const FormatStyle &Style,
       CurrentLines(&Lines), Style(Style), Keywords(Keywords),
       CommentPragmasRegex(Style.CommentPragmas), Tokens(nullptr),
       Callback(Callback), AllTokens(Tokens), PPBranchLevel(-1),
-      IfNdefCondition(nullptr), FoundIncludeGuardStart(false),
-      IncludeGuardRejected(false), FirstStartColumn(FirstStartColumn) {}
+      IncludeGuard(Style.IndentPPDirectives == FormatStyle::PPDIS_None
+                       ? IG_Rejected
+                       : IG_Inited),
+      IncludeGuardToken(nullptr), FirstStartColumn(FirstStartColumn) {}
 
 void UnwrappedLineParser::reset() {
   PPBranchLevel = -1;
-  IfNdefCondition = nullptr;
-  FoundIncludeGuardStart = false;
-  IncludeGuardRejected = false;
+  IncludeGuard = Style.IndentPPDirectives == FormatStyle::PPDIS_None
+                     ? IG_Rejected
+                     : IG_Inited;
+  IncludeGuardToken = nullptr;
   Line.reset(new UnwrappedLine);
   CommentsBeforeNextToken.clear();
   FormatTok = nullptr;
@@ -264,6 +267,14 @@ void UnwrappedLineParser::parse() {
 
     readToken();
     parseFile();
+
+    // If we found an include guard then all preprocessor directives (other than
+    // the guard) are over-indented by one.
+    if (IncludeGuard == IG_Found)
+      for (auto &Line : Lines)
+        if (Line.InPPDirective && Line.Level > 0)
+          --Line.Level;
+
     // Create line with eof token.
     pushToken(FormatTok);
     addUnwrappedLine();
@@ -712,26 +723,27 @@ void UnwrappedLineParser::parsePPIf(bool IfDef) {
   // If there's a #ifndef on the first line, and the only lines before it are
   // comments, it could be an include guard.
   bool MaybeIncludeGuard = IfNDef;
-  if (!IncludeGuardRejected && !FoundIncludeGuardStart && MaybeIncludeGuard) {
+  if (IncludeGuard == IG_Inited && MaybeIncludeGuard)
     for (auto &Line : Lines) {
       if (!Line.Tokens.front().Tok->is(tok::comment)) {
         MaybeIncludeGuard = false;
-        IncludeGuardRejected = true;
+        IncludeGuard = IG_Rejected;
         break;
       }
     }
-  }
   --PPBranchLevel;
   parsePPUnknown();
   ++PPBranchLevel;
-  if (!IncludeGuardRejected && !FoundIncludeGuardStart && MaybeIncludeGuard)
-    IfNdefCondition = IfCondition;
+  if (IncludeGuard == IG_Inited && MaybeIncludeGuard) {
+    IncludeGuard = IG_IfNdefed;
+    IncludeGuardToken = IfCondition;
+  }
 }
 
 void UnwrappedLineParser::parsePPElse() {
   // If a potential include guard has an #else, it's not an include guard.
-  if (FoundIncludeGuardStart && PPBranchLevel == 0)
-    FoundIncludeGuardStart = false;
+  if (IncludeGuard == IG_Defined && PPBranchLevel == 0)
+    IncludeGuard = IG_Rejected;
   conditionalCompilationAlternative();
   if (PPBranchLevel > -1)
     --PPBranchLevel;
@@ -745,34 +757,37 @@ void UnwrappedLineParser::parsePPEndIf() {
   conditionalCompilationEnd();
   parsePPUnknown();
   // If the #endif of a potential include guard is the last thing in the file,
-  // then we count it as a real include guard and subtract one from every
-  // preprocessor indent.
+  // then we found an include guard.
   unsigned TokenPosition = Tokens->getPosition();
   FormatToken *PeekNext = AllTokens[TokenPosition];
-  if (FoundIncludeGuardStart && PPBranchLevel == -1 && PeekNext->is(tok::eof) &&
+  if (IncludeGuard == IG_Defined && PPBranchLevel == -1 &&
+      PeekNext->is(tok::eof) &&
       Style.IndentPPDirectives != FormatStyle::PPDIS_None)
-    for (auto &Line : Lines)
-      if (Line.InPPDirective && Line.Level > 0)
-        --Line.Level;
+    IncludeGuard = IG_Found;
 }
 
 void UnwrappedLineParser::parsePPDefine() {
   nextToken();
 
   if (FormatTok->Tok.getKind() != tok::identifier) {
+    IncludeGuard = IG_Rejected;
+    IncludeGuardToken = nullptr;
     parsePPUnknown();
     return;
   }
-  if (IfNdefCondition && IfNdefCondition->TokenText == FormatTok->TokenText) {
-    FoundIncludeGuardStart = true;
+
+  if (IncludeGuard == IG_IfNdefed &&
+      IncludeGuardToken->TokenText == FormatTok->TokenText) {
+    IncludeGuard = IG_Defined;
+    IncludeGuardToken = nullptr;
     for (auto &Line : Lines) {
       if (!Line.Tokens.front().Tok->isOneOf(tok::comment, tok::hash)) {
-        FoundIncludeGuardStart = false;
+        IncludeGuard = IG_Rejected;
         break;
       }
     }
   }
-  IfNdefCondition = nullptr;
+
   nextToken();
   if (FormatTok->Tok.getKind() == tok::l_paren &&
       FormatTok->WhitespaceRange.getBegin() ==
@@ -799,7 +814,6 @@ void UnwrappedLineParser::parsePPUnknown() {
   if (Style.IndentPPDirectives == FormatStyle::PPDIS_AfterHash)
     Line->Level += PPBranchLevel + 1;
   addUnwrappedLine();
-  IfNdefCondition = nullptr;
 }
 
 // Here we blacklist certain tokens that are not usually the first token in an
diff --git a/lib/Format/UnwrappedLineParser.h b/lib/Format/UnwrappedLineParser.h
index 1d8ccabbd0f8..cee03e9bce33 100644
--- a/lib/Format/UnwrappedLineParser.h
+++ b/lib/Format/UnwrappedLineParser.h
@@ -248,10 +248,23 @@ private:
   // sequence.
   std::stack<int> PPChainBranchIndex;
 
-  // Contains the #ifndef condition for a potential include guard.
-  FormatToken *IfNdefCondition;
-  bool FoundIncludeGuardStart;
-  bool IncludeGuardRejected;
+  // Include guard search state. Used to fixup preprocessor indent levels
+  // so that include guards do not participate in indentation.
+  enum IncludeGuardState {
+    IG_Inited,   // Search started, looking for #ifndef.
+    IG_IfNdefed, // #ifndef found, IncludeGuardToken points to condition.
+    IG_Defined,  // Matching #define found, checking other requirements.
+    IG_Found,    // All requirements met, need to fix indents.
+    IG_Rejected, // Search failed or never started.
+  };
+
+  // Current state of include guard search.
+  IncludeGuardState IncludeGuard;
+
+  // Points to the #ifndef condition for a potential include guard. Null unless
+  // IncludeGuardState == IG_IfNdefed.
+  FormatToken *IncludeGuardToken;
+
   // Contains the first start column where the source begins. This is zero for
   // normal source code and may be nonzero when formatting a code fragment that
   // does not start at the beginning of the file.
diff --git a/lib/Headers/avx512bwintrin.h b/lib/Headers/avx512bwintrin.h
index 3ff0e3aafdcc..064300a48798 100644
--- a/lib/Headers/avx512bwintrin.h
+++ b/lib/Headers/avx512bwintrin.h
@@ -1854,13 +1854,15 @@ _mm512_maskz_set1_epi8 (__mmask64 __M, char __A)
 static __inline__ __mmask64 __DEFAULT_FN_ATTRS
 _mm512_kunpackd (__mmask64 __A, __mmask64 __B)
 {
-  return (__mmask64)  (( __A  & 0xFFFFFFFF) | ( __B << 32));
+  return (__mmask64) __builtin_ia32_kunpckdi ((__mmask64) __A,
+                (__mmask64) __B);
 }
 
 static __inline__ __mmask32 __DEFAULT_FN_ATTRS
 _mm512_kunpackw (__mmask32 __A, __mmask32 __B)
 {
-return (__mmask32)  (( __A  & 0xFFFF) | ( __B << 16));
+  return (__mmask32) __builtin_ia32_kunpcksi ((__mmask32) __A,
+                (__mmask32) __B);
 }
 
 static __inline__ __m512i __DEFAULT_FN_ATTRS
diff --git a/lib/Headers/avx512fintrin.h b/lib/Headers/avx512fintrin.h
index d34f0b1327ae..f5137428ba3f 100644
--- a/lib/Headers/avx512fintrin.h
+++ b/lib/Headers/avx512fintrin.h
@@ -8787,7 +8787,7 @@ _mm512_kortestz (__mmask16 __A, __mmask16 __B)
 static __inline__ __mmask16 __DEFAULT_FN_ATTRS
 _mm512_kunpackb (__mmask16 __A, __mmask16 __B)
 {
-  return (__mmask16)  (( __A  & 0xFF) | ( __B << 8));
+  return (__mmask16) __builtin_ia32_kunpckhi ((__mmask16) __A, (__mmask16) __B);
 }
 
 static __inline__ __mmask16 __DEFAULT_FN_ATTRS
diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index cbec5e6b6385..ec342ee3ae2a 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -738,15 +738,17 @@ void NumericLiteralParser::ParseDecimalOrOctalCommon(SourceLocation TokLoc){
     s++;
     radix = 10;
     saw_exponent = true;
-    if (*s == '+' || *s == '-')  s++; // sign
+    if (s != ThisTokEnd && (*s == '+' || *s == '-'))  s++; // sign
     const char *first_non_digit = SkipDigits(s);
     if (containsDigits(s, first_non_digit)) {
       checkSeparator(TokLoc, s, CSK_BeforeDigits);
       s = first_non_digit;
     } else {
-      PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
-              diag::err_exponent_has_no_digits);
-      hadError = true;
+      if (!hadError) {
+        PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
+                diag::err_exponent_has_no_digits);
+        hadError = true;
+      }
       return;
     }
   }
@@ -787,10 +789,12 @@ void NumericLiteralParser::checkSeparator(SourceLocation TokLoc,
   } else if (Pos == ThisTokEnd)
     return;
 
-  if (isDigitSeparator(*Pos))
+  if (isDigitSeparator(*Pos)) {
     PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Pos - ThisTokBegin),
             diag::err_digit_separator_not_between_digits)
       << IsAfterDigits;
+    hadError = true;
+  }
 }
 
 /// ParseNumberStartingWithZero - This method is called when the first character
@@ -840,12 +844,14 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
       const char *Exponent = s;
       s++;
       saw_exponent = true;
-      if (*s == '+' || *s == '-')  s++; // sign
+      if (s != ThisTokEnd && (*s == '+' || *s == '-'))  s++; // sign
       const char *first_non_digit = SkipDigits(s);
       if (!containsDigits(s, first_non_digit)) {
-        PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
-                diag::err_exponent_has_no_digits);
-        hadError = true;
+        if (!hadError) {
+          PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, Exponent-ThisTokBegin),
+                  diag::err_exponent_has_no_digits);
+          hadError = true;
+        }
         return;
       }
       checkSeparator(TokLoc, s, CSK_BeforeDigits);
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 803f87b3c568..57af6b86bf80 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -8972,6 +8972,16 @@ static void AnalyzeComparison(Sema &S, BinaryOperator *E) {
   LHS = LHS->IgnoreParenImpCasts();
   RHS = RHS->IgnoreParenImpCasts();
 
+  if (!S.getLangOpts().CPlusPlus) {
+    // Avoid warning about comparison of integers with different signs when
+    // RHS/LHS has a `typeof(E)` type whose sign is different from the sign of
+    // the type of `E`.
+    if (const auto *TET = dyn_cast<TypeOfExprType>(LHS->getType()))
+      LHS = TET->getUnderlyingExpr()->IgnoreParenImpCasts();
+    if (const auto *TET = dyn_cast<TypeOfExprType>(RHS->getType()))
+      RHS = TET->getUnderlyingExpr()->IgnoreParenImpCasts();
+  }
+
   // Check to see if one of the (unmodified) operands is of different
   // signedness.
   Expr *signedOperand, *unsignedOperand;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 743f4bb5e822..7ca48c34e516 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -12507,10 +12507,20 @@ void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D,
 /// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
 NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
                                           IdentifierInfo &II, Scope *S) {
+  // Find the scope in which the identifier is injected and the corresponding
+  // DeclContext.
+  // FIXME: C89 does not say what happens if there is no enclosing block scope.
+  // In that case, we inject the declaration into the translation unit scope
+  // instead.
   Scope *BlockScope = S;
   while (!BlockScope->isCompoundStmtScope() && BlockScope->getParent())
     BlockScope = BlockScope->getParent();
 
+  Scope *ContextScope = BlockScope;
+  while (!ContextScope->getEntity())
+    ContextScope = ContextScope->getParent();
+  ContextRAII SavedContext(*this, ContextScope->getEntity());
+
   // Before we produce a declaration for an implicitly defined
   // function, see whether there was a locally-scoped declaration of
   // this name as a function or variable. If so, use that
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 011051da58e5..df64a33954fa 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -352,6 +352,7 @@ class InitListChecker {
                                bool FillWithNoInit = false);
   void FillInEmptyInitializations(const InitializedEntity &Entity,
                                   InitListExpr *ILE, bool &RequiresSecondPass,
+                                  InitListExpr *OuterILE, unsigned OuterIndex,
                                   bool FillWithNoInit = false);
   bool CheckFlexibleArrayInit(const InitializedEntity &Entity,
                               Expr *InitExpr, FieldDecl *Field,
@@ -517,12 +518,13 @@ void InitListChecker::FillInEmptyInitForBase(
     ILE->setInit(Init, BaseInit.getAs<Expr>());
   } else if (InitListExpr *InnerILE =
                  dyn_cast<InitListExpr>(ILE->getInit(Init))) {
-    FillInEmptyInitializations(BaseEntity, InnerILE,
-                               RequiresSecondPass, FillWithNoInit);
+    FillInEmptyInitializations(BaseEntity, InnerILE, RequiresSecondPass,
+                               ILE, Init, FillWithNoInit);
   } else if (DesignatedInitUpdateExpr *InnerDIUE =
                dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
     FillInEmptyInitializations(BaseEntity, InnerDIUE->getUpdater(),
-                               RequiresSecondPass, /*FillWithNoInit =*/true);
+                               RequiresSecondPass, ILE, Init,
+                               /*FillWithNoInit =*/true);
   }
 }
 
@@ -605,24 +607,43 @@ void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
   } else if (InitListExpr *InnerILE
                = dyn_cast<InitListExpr>(ILE->getInit(Init)))
     FillInEmptyInitializations(MemberEntity, InnerILE,
-                               RequiresSecondPass, FillWithNoInit);
+                               RequiresSecondPass, ILE, Init, FillWithNoInit);
   else if (DesignatedInitUpdateExpr *InnerDIUE
                = dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init)))
     FillInEmptyInitializations(MemberEntity, InnerDIUE->getUpdater(),
-                               RequiresSecondPass, /*FillWithNoInit =*/ true);
+                               RequiresSecondPass, ILE, Init,
+                               /*FillWithNoInit =*/true);
 }
 
 /// Recursively replaces NULL values within the given initializer list
 /// with expressions that perform value-initialization of the
-/// appropriate type.
+/// appropriate type, and finish off the InitListExpr formation.
 void
 InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
                                             InitListExpr *ILE,
                                             bool &RequiresSecondPass,
+                                            InitListExpr *OuterILE,
+                                            unsigned OuterIndex,
                                             bool FillWithNoInit) {
   assert((ILE->getType() != SemaRef.Context.VoidTy) &&
          "Should not have void type");
 
+  // If this is a nested initializer list, we might have changed its contents
+  // (and therefore some of its properties, such as instantiation-dependence)
+  // while filling it in. Inform the outer initializer list so that its state
+  // can be updated to match.
+  // FIXME: We should fully build the inner initializers before constructing
+  // the outer InitListExpr instead of mutating AST nodes after they have
+  // been used as subexpressions of other nodes.
+  struct UpdateOuterILEWithUpdatedInit {
+    InitListExpr *Outer;
+    unsigned OuterIndex;
+    ~UpdateOuterILEWithUpdatedInit() {
+      if (Outer)
+        Outer->setInit(OuterIndex, Outer->getInit(OuterIndex));
+    }
+  } UpdateOuterRAII = {OuterILE, OuterIndex};
+
   // A transparent ILE is not performing aggregate initialization and should
   // not be filled in.
   if (ILE->isTransparent())
@@ -769,11 +790,12 @@ InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
     } else if (InitListExpr *InnerILE
                  = dyn_cast_or_null<InitListExpr>(InitExpr))
       FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass,
-                                 FillWithNoInit);
+                                 ILE, Init, FillWithNoInit);
     else if (DesignatedInitUpdateExpr *InnerDIUE
                  = dyn_cast_or_null<DesignatedInitUpdateExpr>(InitExpr))
       FillInEmptyInitializations(ElementEntity, InnerDIUE->getUpdater(),
-                                 RequiresSecondPass, /*FillWithNoInit =*/ true);
+                                 RequiresSecondPass, ILE, Init,
+                                 /*FillWithNoInit =*/true);
   }
 }
 
@@ -795,10 +817,11 @@ InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
 
   if (!hadError && !VerifyOnly) {
     bool RequiresSecondPass = false;
-    FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass);
+    FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
+                               /*OuterILE=*/nullptr, /*OuterIndex=*/0);
     if (RequiresSecondPass && !hadError)
       FillInEmptyInitializations(Entity, FullyStructuredList,
-                                 RequiresSecondPass);
+                                 RequiresSecondPass, nullptr, 0);
   }
 }
 
@@ -1162,10 +1185,12 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
       if (!hadError && !VerifyOnly) {
         bool RequiresSecondPass = false;
         FillInEmptyInitializations(Entity, InnerStructuredList,
-                                   RequiresSecondPass);
+                                   RequiresSecondPass, StructuredList,
+                                   StructuredIndex);
         if (RequiresSecondPass && !hadError)
           FillInEmptyInitializations(Entity, InnerStructuredList,
-                                     RequiresSecondPass);
+                                     RequiresSecondPass, StructuredList,
+                                     StructuredIndex);
       }
       ++StructuredIndex;
       ++Index;
diff --git a/test/CodeGen/avx512bw-builtins.c b/test/CodeGen/avx512bw-builtins.c
index 3160a6667c00..190387b2d97a 100644
--- a/test/CodeGen/avx512bw-builtins.c
+++ b/test/CodeGen/avx512bw-builtins.c
@@ -1626,26 +1626,16 @@ __m512i test_mm512_maskz_set1_epi8(__mmask64 __M, char __A) {
   return _mm512_maskz_set1_epi8(__M, __A); 
 }
 
-__mmask64 test_mm512_kunpackd(__m512i __A, __m512i __B, __m512i __C, __m512i __D, __m512i __E, __m512i __F) {
+__mmask64 test_mm512_kunpackd(__mmask64 __A, __mmask64 __B) {
   // CHECK-LABEL: @test_mm512_kunpackd
-  // CHECK: bitcast <64 x i1> %{{.*}} to i64
-  // CHECK: bitcast <64 x i1> %{{.*}} to i64
-  // CHECK: and i64 %{{.*}}, 4294967295
-  // CHECK: shl i64 %{{.*}}, 32
-  // CHECK: or i64 %{{.*}}, %{{.*}}
-  // CHECK: bitcast i64 %{{.*}} to <64 x i1>
-  return _mm512_mask_cmpneq_epu8_mask(_mm512_kunpackd(_mm512_cmpneq_epu8_mask(__B, __A),_mm512_cmpneq_epu8_mask(__C, __D)), __E, __F); 
+  // CHECK: @llvm.x86.avx512.kunpck.dq
+  return _mm512_kunpackd(__A, __B); 
 }
 
-__mmask32 test_mm512_kunpackw(__m512i __A, __m512i __B, __m512i __C, __m512i __D, __m512i __E, __m512i __F) {
+__mmask32 test_mm512_kunpackw(__mmask32 __A, __mmask32 __B) {
   // CHECK-LABEL: @test_mm512_kunpackw
-  // CHECK: bitcast <32 x i1> %{{.*}} to i32
-  // CHECK: bitcast <32 x i1> %{{.*}} to i32
-  // CHECK: and i32 %{{.*}}, 65535
-  // CHECK: shl i32 %{{.*}}, 16
-  // CHECK: or i32 %{{.*}}, %{{.*}}
-  // CHECK: bitcast i32 %{{.*}} to <32 x i1>
-  return _mm512_mask_cmpneq_epu16_mask(_mm512_kunpackw(_mm512_cmpneq_epu16_mask(__B, __A),_mm512_cmpneq_epu16_mask(__C, __D)), __E, __F); 
+  // CHECK: @llvm.x86.avx512.kunpck.wd
+  return _mm512_kunpackw(__A, __B); 
 }
 
 __m512i test_mm512_mask_loadu_epi16(__m512i __W, __mmask32 __U, void const *__P) {
diff --git a/test/CodeGen/avx512f-builtins.c b/test/CodeGen/avx512f-builtins.c
index ce831d690ee7..2ba2faf1b697 100644
--- a/test/CodeGen/avx512f-builtins.c
+++ b/test/CodeGen/avx512f-builtins.c
@@ -6259,17 +6259,10 @@ int test_mm512_kortestz(__mmask16 __A, __mmask16 __B) {
   return _mm512_kortestz(__A, __B); 
 }
 
-__mmask16 test_mm512_kunpackb(__m512i __A, __m512i __B, __m512i __C, __m512i __D, __m512i __E, __m512i __F) {
+__mmask16 test_mm512_kunpackb(__mmask16 __A, __mmask16 __B) {
   // CHECK-LABEL: @test_mm512_kunpackb
-  // CHECK: bitcast <16 x i1> %{{.*}} to i16
-  // CHECK: bitcast <16 x i1> %{{.*}} to i16
-  // CHECK: and i32 %{{.*}}, 255
-  // CHECK: shl i32 %{{.*}}, 8
-  // CHECK: or i32 %{{.*}}, %{{.*}}
-  // CHECK: bitcast i16 %{{.*}} to <16 x i1>
-  return _mm512_mask_cmpneq_epu32_mask(_mm512_kunpackb(_mm512_cmpneq_epu32_mask(__A, __B),
-                                                       _mm512_cmpneq_epu32_mask(__C, __D)),
-                                                       __E, __F);
+  // CHECK: @llvm.x86.avx512.kunpck.bw
+  return _mm512_kunpackb(__A, __B); 
 }
 
 __mmask16 test_mm512_kxnor(__m512i __A, __m512i __B, __m512i __C, __m512i __D, __m512i __E, __m512i __F) {
diff --git a/test/CodeGen/ms_abi.c b/test/CodeGen/ms_abi.c
index 407087e40916..7486166c78d4 100644
--- a/test/CodeGen/ms_abi.c
+++ b/test/CodeGen/ms_abi.c
@@ -146,3 +146,16 @@ void __attribute__((sysv_abi)) f6(__builtin_ms_va_list ap) {
   // WIN64: %[[AP_VAL:.*]] = load i8*, i8** %[[AP]]
   // WIN64-NEXT: store i8* %[[AP_VAL]], i8** %[[AP2:.*]]
 }
+
+// This test checks if structs are passed according to Win64 calling convention
+// when it's enforced by __attribute((ms_abi)).
+struct i128 {
+  unsigned long long a;
+  unsigned long long b;
+};
+
+__attribute__((ms_abi)) struct i128 f7(struct i128 a) {
+  // WIN64: define void @f7(%struct.i128* noalias sret %agg.result, %struct.i128* %a)
+  // FREEBSD: define win64cc void @f7(%struct.i128* noalias sret %agg.result, %struct.i128* %a)
+  return a;
+}
diff --git a/test/CodeGenCXX/dllimport-missing-key.cpp b/test/CodeGenCXX/dllimport-missing-key.cpp
new file mode 100644
index 000000000000..d8ef7aa7ea68
--- /dev/null
+++ b/test/CodeGenCXX/dllimport-missing-key.cpp
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -triple i686-windows-gnu -emit-llvm -std=c++1y -O0 -o - %s -w | FileCheck --check-prefix=GNU %s
+
+class __declspec(dllimport) QObjectData {
+public:
+    virtual ~QObjectData() = 0;
+    void *ptr;
+
+    int method() const;
+};
+
+class LocalClass : public QObjectData {
+};
+
+void call() {
+    (new LocalClass())->method();
+}
+
+// GNU-DAG: @_ZTV11QObjectData = available_externally dllimport
+// GNU-DAG: @_ZTS11QObjectData = linkonce_odr
+// GNU-DAG: @_ZTI11QObjectData = linkonce_odr
diff --git a/test/CodeGenCXX/dllimport-rtti.cpp b/test/CodeGenCXX/dllimport-rtti.cpp
index 91e747ae1c15..dfb39a15eda5 100644
--- a/test/CodeGenCXX/dllimport-rtti.cpp
+++ b/test/CodeGenCXX/dllimport-rtti.cpp
@@ -12,7 +12,7 @@ struct __declspec(dllimport) S {
 // MSVC-DAG: @"\01??_R3S@@8" = linkonce_odr
 
 // GNU-DAG: @_ZTV1S = available_externally dllimport
-// GNU-DAG: @_ZTI1S = external dllimport
+// GNU-DAG: @_ZTI1S = linkonce_odr
 
 struct U : S {
 } u;
diff --git a/test/CodeGenCXX/microsoft-abi-emit-dependent.cpp b/test/CodeGenCXX/microsoft-abi-emit-dependent.cpp
new file mode 100644
index 000000000000..e74ebc879f5b
--- /dev/null
+++ b/test/CodeGenCXX/microsoft-abi-emit-dependent.cpp
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -emit-llvm-only -fmodules -triple x86_64-windows %s
+// PR36181
+#pragma clang module build foo
+module foo {}
+#pragma clang module contents
+template <typename T> struct A {
+  friend void f(A<T>) {}
+};
+#pragma clang module endbuild
+#pragma clang module import foo
+void g() { f(A<int>()); }
diff --git a/test/CodeGenCXX/msabi-swiftcall-cc.cpp b/test/CodeGenCXX/msabi-swiftcall-cc.cpp
new file mode 100644
index 000000000000..5a5453af8fa1
--- /dev/null
+++ b/test/CodeGenCXX/msabi-swiftcall-cc.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -triple i686-unknown-windows-msvc -fdeclspec -emit-llvm %s -o - | FileCheck %s
+
+void __attribute__((__swiftcall__)) f() {}
+// CHECK-DAG: @"\01?f@@YSXXZ"
+
+void (__attribute__((__swiftcall__)) *p)();
+// CHECK-DAG: @"\01?p@@3P6SXXZA"
+
+namespace {
+void __attribute__((__swiftcall__)) __attribute__((__used__)) f() { }
+// CHECK-DAG: "\01?f@?A@@YSXXZ"
+}
+
+namespace n {
+void __attribute__((__swiftcall__)) f() {}
+// CHECK-DAG: "\01?f@n@@YSXXZ"
+}
+
+struct __declspec(dllexport) S {
+  S(const S &) = delete;
+  S & operator=(const S &) = delete;
+  void __attribute__((__swiftcall__)) m() { }
+  // CHECK-DAG: "\01?m@S@@QASXXZ"
+};
+
+void f(void (__attribute__((__swiftcall__))())) {}
+// CHECK-DAG: "\01?f@@YAXP6SXXZ@Z"
+
diff --git a/test/Lexer/cxx1y_digit_separators.cpp b/test/Lexer/cxx1y_digit_separators.cpp
index 55366342eda0..67dcd7c510ed 100644
--- a/test/Lexer/cxx1y_digit_separators.cpp
+++ b/test/Lexer/cxx1y_digit_separators.cpp
@@ -51,6 +51,8 @@ namespace floating {
   float u = 0x.'p1f; // expected-error {{hexadecimal floating literal requires a significand}}
   float v = 0e'f; // expected-error {{exponent has no digits}}
   float w = 0x0p'f; // expected-error {{exponent has no digits}}
+  float x = 0'e+1; // expected-error {{digit separator cannot appear at end of digit sequence}}
+  float y = 0x0'p+1; // expected-error {{digit separator cannot appear at end of digit sequence}}
 }
 
 #line 123'456
diff --git a/test/Sema/bitfield.c b/test/Sema/bitfield.c
index d625366e4e1f..13e9480a378b 100644
--- a/test/Sema/bitfield.c
+++ b/test/Sema/bitfield.c
@@ -82,3 +82,7 @@ typedef __typeof__(+(t5.n--)) Unsigned; // also act like compound-assignment.
 struct Test6 {
   : 0.0; // expected-error{{type name requires a specifier or qualifier}}
 };
+
+struct PR36157 {
+  int n : 1 ? 1 : implicitly_declare_function(); // expected-warning {{invalid in C99}}
+};
diff --git a/test/Sema/compare.c b/test/Sema/compare.c
index 7cd8adab8921..b2b486f59f87 100644
--- a/test/Sema/compare.c
+++ b/test/Sema/compare.c
@@ -391,3 +391,16 @@ typedef char two_chars[2];
 void test12(unsigned a) {
   if (0 && -1 > a) { }
 }
+
+// PR36008
+
+enum PR36008EnumTest {
+  kPR36008Value = 0,
+};
+
+void pr36008(enum PR36008EnumTest lhs) {
+  __typeof__(lhs) x = lhs;
+  __typeof__(kPR36008Value) y = (kPR36008Value);
+  if (x == y) x = y; // no warning
+  if (y == x) y = x; // no warning
+}
diff --git a/test/Sema/cxx-as-c.c b/test/Sema/cxx-as-c.c
new file mode 100644
index 000000000000..41d7350d1f15
--- /dev/null
+++ b/test/Sema/cxx-as-c.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 %s -verify
+
+// PR36157
+struct Foo {
+  Foo(int n) : n_(n) {} // expected-error 1+{{}} expected-warning 1+{{}}
+private:
+  int n;
+};
+int main() { Foo f; } // expected-error 1+{{}}
diff --git a/test/SemaCXX/init-expr-crash.cpp b/test/SemaCXX/init-expr-crash.cpp
index 407da78e60b0..201ab03955cd 100644
--- a/test/SemaCXX/init-expr-crash.cpp
+++ b/test/SemaCXX/init-expr-crash.cpp
@@ -29,3 +29,11 @@ template <class T> struct B {
     return 0;
   }
 };
+
+// This test checks for a crash that resulted from us miscomputing the
+// dependence of a nested initializer list.
+template<int> struct X {
+  static constexpr int n = 4;
+  static constexpr int a[1][1] = {n};
+};
+
diff --git a/test/SemaCXX/type-traits.cpp b/test/SemaCXX/type-traits.cpp
index b334e507554f..3c2f9c7f0fb6 100644
--- a/test/SemaCXX/type-traits.cpp
+++ b/test/SemaCXX/type-traits.cpp
@@ -2524,6 +2524,7 @@ static_assert(!has_unique_object_representations<const int &>::value, "No refere
 static_assert(!has_unique_object_representations<volatile int &>::value, "No references!");
 static_assert(!has_unique_object_representations<const volatile int &>::value, "No references!");
 static_assert(!has_unique_object_representations<Empty>::value, "No empty types!");
+static_assert(!has_unique_object_representations<EmptyUnion>::value, "No empty types!");
 
 class Compressed : Empty {
   int x;
diff --git a/test/SemaTemplate/instantiate-init.cpp b/test/SemaTemplate/instantiate-init.cpp
index 244e94f6d605..51fa6955d0c0 100644
--- a/test/SemaTemplate/instantiate-init.cpp
+++ b/test/SemaTemplate/instantiate-init.cpp
@@ -142,3 +142,17 @@ namespace ReturnStmtIsInitialization {
   template<typename T> X f() { return {}; }
   auto &&x = f<void>();
 }
+
+namespace InitListUpdate {
+  struct A { int n; };
+  using AA = A[1];
+
+  // Check that an init list update doesn't "lose" the pack-ness of an expression.
+  template <int... N> void f() {
+    g(AA{0, [0].n = N} ...); // expected-warning 3{{overrides prior init}} expected-note 3{{previous init}}
+    g(AA{N, [0].n = 0} ...); // expected-warning 3{{overrides prior init}} expected-note 3{{previous init}}
+  };
+
+  void g(AA, AA);
+  void h() { f<1, 2>(); } // expected-note {{instantiation of}}
+}
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 2cae9dd0c547..593caf0fdc9a 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -2532,6 +2532,20 @@ TEST_F(FormatTest, IndentPreprocessorDirectives) {
                "#elif FOO\n"
                "#endif",
                Style);
+  // Non-identifier #define after potential include guard.
+  verifyFormat("#ifndef FOO\n"
+               "#  define 1\n"
+               "#endif\n",
+               Style);
+  // #if closes past last non-preprocessor line.
+  verifyFormat("#ifndef FOO\n"
+               "#define FOO\n"
+               "#if 1\n"
+               "int i;\n"
+               "#  define A 0\n"
+               "#endif\n"
+               "#endif\n",
+               Style);
   // FIXME: This doesn't handle the case where there's code between the
   // #ifndef and #define but all other conditions hold. This is because when
   // the #define line is parsed, UnwrappedLineParser::Lines doesn't hold the
@@ -2580,21 +2594,85 @@ TEST_F(FormatTest, IndentPreprocessorDirectives) {
                    "code();\n"
                    "#endif",
                    Style));
-  // FIXME: The comment indent corrector in TokenAnnotator gets thrown off by
-  // preprocessor indentation.
-  EXPECT_EQ("#if 1\n"
-            "  // comment\n"
-            "#  define A 0\n"
-            "// comment\n"
-            "#  define B 0\n"
-            "#endif",
-            format("#if 1\n"
-                   "// comment\n"
-                   "#  define A 0\n"
-                   "   // comment\n"
-                   "#  define B 0\n"
-                   "#endif",
-                   Style));
+  // Keep comments aligned with #, otherwise indent comments normally. These
+  // tests cannot use verifyFormat because messUp manipulates leading
+  // whitespace.
+  {
+    const char *Expected = ""
+                           "void f() {\n"
+                           "#if 1\n"
+                           "// Preprocessor aligned.\n"
+                           "#  define A 0\n"
+                           "  // Code. Separated by blank line.\n"
+                           "\n"
+                           "#  define B 0\n"
+                           "  // Code. Not aligned with #\n"
+                           "#  define C 0\n"
+                           "#endif";
+    const char *ToFormat = ""
+                           "void f() {\n"
+                           "#if 1\n"
+                           "// Preprocessor aligned.\n"
+                           "#  define A 0\n"
+                           "// Code. Separated by blank line.\n"
+                           "\n"
+                           "#  define B 0\n"
+                           "   // Code. Not aligned with #\n"
+                           "#  define C 0\n"
+                           "#endif";
+    EXPECT_EQ(Expected, format(ToFormat, Style));
+    EXPECT_EQ(Expected, format(Expected, Style));
+  }
+  // Keep block quotes aligned.
+  {
+    const char *Expected = ""
+                           "void f() {\n"
+                           "#if 1\n"
+                           "/* Preprocessor aligned. */\n"
+                           "#  define A 0\n"
+                           "  /* Code. Separated by blank line. */\n"
+                           "\n"
+                           "#  define B 0\n"
+                           "  /* Code. Not aligned with # */\n"
+                           "#  define C 0\n"
+                           "#endif";
+    const char *ToFormat = ""
+                           "void f() {\n"
+                           "#if 1\n"
+                           "/* Preprocessor aligned. */\n"
+                           "#  define A 0\n"
+                           "/* Code. Separated by blank line. */\n"
+                           "\n"
+                           "#  define B 0\n"
+                           "   /* Code. Not aligned with # */\n"
+                           "#  define C 0\n"
+                           "#endif";
+    EXPECT_EQ(Expected, format(ToFormat, Style));
+    EXPECT_EQ(Expected, format(Expected, Style));
+  }
+  // Keep comments aligned with un-indented directives.
+  {
+    const char *Expected = ""
+                           "void f() {\n"
+                           "// Preprocessor aligned.\n"
+                           "#define A 0\n"
+                           "  // Code. Separated by blank line.\n"
+                           "\n"
+                           "#define B 0\n"
+                           "  // Code. Not aligned with #\n"
+                           "#define C 0\n";
+    const char *ToFormat = ""
+                           "void f() {\n"
+                           "// Preprocessor aligned.\n"
+                           "#define A 0\n"
+                           "// Code. Separated by blank line.\n"
+                           "\n"
+                           "#define B 0\n"
+                           "   // Code. Not aligned with #\n"
+                           "#define C 0\n";
+    EXPECT_EQ(Expected, format(ToFormat, Style));
+    EXPECT_EQ(Expected, format(Expected, Style));
+  }
   // Test with tabs.
   Style.UseTab = FormatStyle::UT_Always;
   Style.IndentWidth = 8;