vendor/clang/clang-release_39-r278877

29 files changed, 200 insertions, 178 deletions

diff --git a/lib/AST/ASTDiagnostic.cpp b/lib/AST/ASTDiagnostic.cpp
index 22de8bc0dd050..0f5a8b5ae8926 100644
--- a/lib/AST/ASTDiagnostic.cpp
+++ b/lib/AST/ASTDiagnostic.cpp
@@ -917,6 +917,8 @@ class TemplateDiff {
       /// template argument.
       InternalIterator(const TemplateSpecializationType *TST)
           : TST(TST), Index(0), CurrentTA(nullptr), EndTA(nullptr) {
+        if (!TST) return;
+
         if (isEnd()) return;
 
         // Set to first template argument.  If not a parameter pack, done.
@@ -937,11 +939,13 @@ class TemplateDiff {
 
       /// isEnd - Returns true if the iterator is one past the end.
       bool isEnd() const {
+        assert(TST && "InternalIterator is invalid with a null TST.");
         return Index >= TST->getNumArgs();
       }
 
       /// &operator++ - Increment the iterator to the next template argument.
       InternalIterator &operator++() {
+        assert(TST && "InternalIterator is invalid with a null TST.");
         if (isEnd()) {
           return *this;
         }
@@ -977,6 +981,7 @@ class TemplateDiff {
 
       /// operator* - Returns the appropriate TemplateArgument.
       reference operator*() const {
+        assert(TST && "InternalIterator is invalid with a null TST.");
         assert(!isEnd() && "Index exceeds number of arguments.");
         if (CurrentTA == EndTA)
           return TST->getArg(Index);
@@ -986,6 +991,7 @@ class TemplateDiff {
 
       /// operator-> - Allow access to the underlying TemplateArgument.
       pointer operator->() const {
+        assert(TST && "InternalIterator is invalid with a null TST.");
         return &operator*();
       }
     };
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index d069bfdc3dc28..81f94148d6ed3 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -807,6 +807,17 @@ void CXXRecordDecl::addedMember(Decl *D) {
             data().DefaultedDestructorIsDeleted = true;
         }
 
+        // For an anonymous union member, our overload resolution will perform
+        // overload resolution for its members.
+        if (Field->isAnonymousStructOrUnion()) {
+          data().NeedOverloadResolutionForMoveConstructor |=
+              FieldRec->data().NeedOverloadResolutionForMoveConstructor;
+          data().NeedOverloadResolutionForMoveAssignment |=
+              FieldRec->data().NeedOverloadResolutionForMoveAssignment;
+          data().NeedOverloadResolutionForDestructor |=
+              FieldRec->data().NeedOverloadResolutionForDestructor;
+        }
+
         // C++0x [class.ctor]p5:
         //   A default constructor is trivial [...] if:
         //    -- for all the non-static data members of its class that are of
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index a25a6c7e51358..df944e8f25f29 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -36,7 +36,6 @@
 #include "clang/AST/APValue.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTDiagnostic.h"
-#include "clang/AST/ASTLambda.h"
 #include "clang/AST/CharUnits.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/RecordLayout.h"
@@ -2126,22 +2125,7 @@ static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
   // If this is a local variable, dig out its value.
   if (Frame) {
     Result = Frame->getTemporary(VD);
-    if (!Result) {
-      // Assume variables referenced within a lambda's call operator that were
-      // not declared within the call operator are captures and during checking
-      // of a potential constant expression, assume they are unknown constant
-      // expressions.
-      assert(isLambdaCallOperator(Frame->Callee) &&
-             (VD->getDeclContext() != Frame->Callee || VD->isInitCapture()) &&
-             "missing value for local variable");
-      if (Info.checkingPotentialConstantExpression())
-        return false;
-      // FIXME: implement capture evaluation during constant expr evaluation.
-      Info.FFDiag(E->getLocStart(),
-           diag::note_unimplemented_constexpr_lambda_feature_ast)
-          << "captures not currently allowed";
-      return false;
-    }
+    assert(Result && "missing value for local variable");
     return true;
   }
 
diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index d7a9bdb3d82cd..a67f0910e15a7 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -3902,7 +3902,17 @@ CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const {
     case CFGElement::AutomaticObjectDtor: {
       const VarDecl *var = castAs<CFGAutomaticObjDtor>().getVarDecl();
       QualType ty = var->getType();
-      ty = ty.getNonReferenceType();
+
+      // FIXME: See CFGBuilder::addLocalScopeForVarDecl.
+      //
+      // Lifetime-extending constructs are handled here. This works for a single
+      // temporary in an initializer expression.
+      if (ty->isReferenceType()) {
+        if (const Expr *Init = var->getInit()) {
+          ty = getReferenceInitTemporaryType(astContext, Init);
+        }
+      }
+
       while (const ArrayType *arrayType = astContext.getAsArrayType(ty)) {
         ty = arrayType->getElementType();
       }
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index c3ca8c8af5d5c..7ec06bb17e3fd 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -7094,9 +7094,9 @@ class MipsTargetInfo : public TargetInfo {
     if (ABI == "o32")
       Layout = "m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64";
     else if (ABI == "n32")
-      Layout = "m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32:64-S128";
+      Layout = "m:e-p:32:32-i8:8:32-i16:16:32-i64:64-n32:64-S128";
     else if (ABI == "n64")
-      Layout = "m:m-i8:8:32-i16:16:32-i64:64-n32:64-S128";
+      Layout = "m:e-i8:8:32-i16:16:32-i64:64-n32:64-S128";
     else
       llvm_unreachable("Invalid ABI");
 
diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 5a41f361d9acf..e3658ab9b7624 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -125,10 +125,15 @@ static llvm::Constant *buildBlockDescriptor(CodeGenModule &CGM,
 
   llvm::Constant *init = llvm::ConstantStruct::getAnon(elements);
 
+  unsigned AddrSpace = 0;
+  if (C.getLangOpts().OpenCL)
+    AddrSpace = C.getTargetAddressSpace(LangAS::opencl_constant);
   llvm::GlobalVariable *global =
     new llvm::GlobalVariable(CGM.getModule(), init->getType(), true,
                              llvm::GlobalValue::InternalLinkage,
-                             init, "__block_descriptor_tmp");
+                             init, "__block_descriptor_tmp", nullptr,
+                             llvm::GlobalValue::NotThreadLocal,
+                             AddrSpace);
 
   return llvm::ConstantExpr::getBitCast(global, CGM.getBlockDescriptorType());
 }
@@ -927,7 +932,10 @@ llvm::Type *CodeGenModule::getBlockDescriptorType() {
                              UnsignedLongTy, UnsignedLongTy, nullptr);
 
   // Now form a pointer to that.
-  BlockDescriptorType = llvm::PointerType::getUnqual(BlockDescriptorType);
+  unsigned AddrSpace = 0;
+  if (getLangOpts().OpenCL)
+    AddrSpace = getContext().getTargetAddressSpace(LangAS::opencl_constant);
+  BlockDescriptorType = llvm::PointerType::get(BlockDescriptorType, AddrSpace);
   return BlockDescriptorType;
 }
 
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index c74e53ea84e07..a5fc53113bdcf 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -2209,8 +2209,9 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
       NewArg = Builder.CreateAddrSpaceCast(Arg0, NewArgT);
     else
       NewArg = Builder.CreateBitOrPointerCast(Arg0, NewArgT);
-    auto NewCall = Builder.CreateCall(CGM.CreateRuntimeFunction(FTy,
-      E->getDirectCallee()->getName()), {NewArg});
+    auto NewName = std::string("__") + E->getDirectCallee()->getName().str();
+    auto NewCall =
+        Builder.CreateCall(CGM.CreateRuntimeFunction(FTy, NewName), {NewArg});
     return RValue::get(Builder.CreateBitOrPointerCast(NewCall,
       ConvertType(E->getType())));
   }
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 5e9d73f082fc8..0607a5157a6fc 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -3637,6 +3637,16 @@ void CGDebugInfo::EmitUsingDecl(const UsingDecl &UD) {
   // Emitting one decl is sufficient - debuggers can detect that this is an
   // overloaded name & provide lookup for all the overloads.
   const UsingShadowDecl &USD = **UD.shadow_begin();
+
+  // FIXME: Skip functions with undeduced auto return type for now since we
+  // don't currently have the plumbing for separate declarations & definitions
+  // of free functions and mismatched types (auto in the declaration, concrete
+  // return type in the definition)
+  if (const auto *FD = dyn_cast<FunctionDecl>(USD.getUnderlyingDecl()))
+    if (const auto *AT =
+            FD->getType()->getAs<FunctionProtoType>()->getContainedAutoType())
+      if (AT->getDeducedType().isNull())
+        return;
   if (llvm::DINode *Target =
           getDeclarationOrDefinition(USD.getUnderlyingDecl()))
     DBuilder.createImportedDeclaration(
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 13c02f2181354..77879021f9af6 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -620,14 +620,7 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
     RunCleanupsScope ThenScope(*this);
     EmitStmt(S.getThen());
   }
-  {
-    auto CurBlock = Builder.GetInsertBlock();
-    EmitBranch(ContBlock);
-    // Eliminate any empty blocks that may have been created by nested
-    // control flow statements in the 'then' clause.
-    if (CurBlock)
-      SimplifyForwardingBlocks(CurBlock); 
-  }
+  EmitBranch(ContBlock);
 
   // Emit the 'else' code if present.
   if (const Stmt *Else = S.getElse()) {
@@ -643,12 +636,7 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
     {
       // There is no need to emit line number for an unconditional branch.
       auto NL = ApplyDebugLocation::CreateEmpty(*this);
-      auto CurBlock = Builder.GetInsertBlock();
       EmitBranch(ContBlock);
-      // Eliminate any empty blocks that may have been created by nested
-      // control flow statements emitted in the 'else' clause.
-      if (CurBlock)
-        SimplifyForwardingBlocks(CurBlock); 
     }
   }
 
@@ -1261,6 +1249,14 @@ void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) {
 }
 
 void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S) {
+  // If there is no enclosing switch instance that we're aware of, then this
+  // default statement can be elided. This situation only happens when we've
+  // constant-folded the switch.
+  if (!SwitchInsn) {
+    EmitStmt(S.getSubStmt());
+    return;
+  }
+
   llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest();
   assert(DefaultBlock->empty() &&
          "EmitDefaultStmt: Default block already defined?");
diff --git a/lib/CodeGen/CoverageMappingGen.cpp b/lib/CodeGen/CoverageMappingGen.cpp
index b4dd1a930325f..b011a0f319e37 100644
--- a/lib/CodeGen/CoverageMappingGen.cpp
+++ b/lib/CodeGen/CoverageMappingGen.cpp
@@ -351,6 +351,9 @@ struct EmptyCoverageMappingBuilder : public CoverageMappingBuilder {
     gatherFileIDs(FileIDMapping);
     emitSourceRegions();
 
+    if (MappingRegions.empty())
+      return;
+
     CoverageMappingWriter Writer(FileIDMapping, None, MappingRegions);
     Writer.write(OS);
   }
@@ -604,6 +607,9 @@ struct CounterCoverageMappingBuilder
     emitExpansionRegions();
     gatherSkippedRegions();
 
+    if (MappingRegions.empty())
+      return;
+
     CoverageMappingWriter Writer(VirtualFileMapping, Builder.getExpressions(),
                                  MappingRegions);
     Writer.write(OS);
@@ -620,6 +626,11 @@ struct CounterCoverageMappingBuilder
 
   void VisitDecl(const Decl *D) {
     Stmt *Body = D->getBody();
+
+    // Do not propagate region counts into system headers.
+    if (Body && SM.isInSystemHeader(SM.getSpellingLoc(getStart(Body))))
+      return;
+
     propagateCounts(getRegionCounter(Body), Body);
   }
 
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 4ecbf2bac3c3f..9bb7a59adc1c7 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -3281,6 +3281,19 @@ Tool *CloudABI::buildLinker() const {
   return new tools::cloudabi::Linker(*this);
 }
 
+bool CloudABI::isPIEDefault() const {
+  // Only enable PIE on architectures that support PC-relative
+  // addressing. PC-relative addressing is required, as the process
+  // startup code must be able to relocate itself.
+  switch (getTriple().getArch()) {
+  case llvm::Triple::aarch64:
+  case llvm::Triple::x86_64:
+    return true;
+  default:
+    return false;
+  }
+}
+
 SanitizerMask CloudABI::getSupportedSanitizers() const {
   SanitizerMask Res = ToolChain::getSupportedSanitizers();
   Res |= SanitizerKind::SafeStack;
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index 4e5c3f7f96a6c..369712fa934b9 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -634,8 +634,7 @@ public:
   void AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
                            llvm::opt::ArgStringList &CmdArgs) const override;
 
-  bool isPIEDefault() const override { return true; }
-
+  bool isPIEDefault() const override;
   SanitizerMask getSupportedSanitizers() const override;
   SanitizerMask getDefaultSanitizers() const override;
 
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index af70017edb056..31d4360184508 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -3258,7 +3258,7 @@ static bool shouldUseFramePointerForTarget(const ArgList &Args,
     break;
   }
 
-  if (Triple.isOSLinux()) {
+  if (Triple.isOSLinux() || Triple.getOS() == llvm::Triple::CloudABI) {
     switch (Triple.getArch()) {
     // Don't use a frame pointer on linux if optimizing for certain targets.
     case llvm::Triple::mips64:
@@ -4568,8 +4568,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                                options::OPT_gdwarf_4, options::OPT_gdwarf_5))
     DwarfVersion = DwarfVersionNum(A->getSpelling());
 
-  // Forward -gcodeview.
-  // 'EmitCodeView might have been set by CL-compatibility argument parsing.
+  // Forward -gcodeview. EmitCodeView might have been set by CL-compatibility
+  // argument parsing.
   if (Args.hasArg(options::OPT_gcodeview) || EmitCodeView) {
     // DwarfVersion remains at 0 if no explicit choice was made.
     CmdArgs.push_back("-gcodeview");
@@ -5020,9 +5020,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   Args.AddLastArg(CmdArgs, options::OPT_fdiagnostics_show_template_tree);
   Args.AddLastArg(CmdArgs, options::OPT_fno_elide_type);
 
-  // Forward flags for OpenMP
+  // Forward flags for OpenMP. We don't do this if the current action is an
+  // device offloading action.
+  //
+  // TODO: Allow OpenMP offload actions when they become available.
   if (Args.hasFlag(options::OPT_fopenmp, options::OPT_fopenmp_EQ,
-                   options::OPT_fno_openmp, false)) {
+                   options::OPT_fno_openmp, false) &&
+      JA.isDeviceOffloading(Action::OFK_None)) {
     switch (getOpenMPRuntime(getToolChain(), Args)) {
     case OMPRT_OMP:
     case OMPRT_IOMP5:
@@ -6354,9 +6358,10 @@ void Clang::AddClangCLArgs(const ArgList &Args, types::ID InputType,
     CmdArgs.push_back(Args.MakeArgString(Twine(LangOptions::SSPStrong)));
   }
 
-  // Emit CodeView if -Z7 or -Zd are present.
+  // Emit CodeView if -Z7, -Zd, or -gline-tables-only are present.
   if (Arg *DebugInfoArg =
-          Args.getLastArg(options::OPT__SLASH_Z7, options::OPT__SLASH_Zd)) {
+          Args.getLastArg(options::OPT__SLASH_Z7, options::OPT__SLASH_Zd,
+                          options::OPT_gline_tables_only)) {
     *EmitCodeView = true;
     if (DebugInfoArg->getOption().matches(options::OPT__SLASH_Z7))
       *DebugInfoKind = codegenoptions::LimitedDebugInfo;
@@ -7453,11 +7458,13 @@ void cloudabi::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   // CloudABI only supports static linkage.
   CmdArgs.push_back("-Bstatic");
-
-  // CloudABI uses Position Independent Executables exclusively.
-  CmdArgs.push_back("-pie");
   CmdArgs.push_back("--no-dynamic-linker");
-  CmdArgs.push_back("-zrelro");
+
+  // Provide PIE linker flags in case PIE is default for the architecture.
+  if (ToolChain.isPIEDefault()) {
+    CmdArgs.push_back("-pie");
+    CmdArgs.push_back("-zrelro");
+  }
 
   CmdArgs.push_back("--eh-frame-hdr");
   CmdArgs.push_back("--gc-sections");
diff --git a/lib/Headers/avx512fintrin.h b/lib/Headers/avx512fintrin.h
index badc43650bab1..0bf6582345d4f 100644
--- a/lib/Headers/avx512fintrin.h
+++ b/lib/Headers/avx512fintrin.h
@@ -7484,7 +7484,6 @@ _mm512_mask_cvtsepi64_storeu_epi8 (void * __P, __mmask8 __M, __m512i __A)
 static __inline__ __m256i __DEFAULT_FN_ATTRS
 _mm512_cvtsepi64_epi32 (__m512i __A)
 {
-  __v8si __O;
   return (__m256i) __builtin_ia32_pmovsqd512_mask ((__v8di) __A,
                (__v8si) _mm256_undefined_si256 (),
                (__mmask8) -1);
diff --git a/lib/Headers/avxintrin.h b/lib/Headers/avxintrin.h
index 86bfdfb80c796..32e8546817b3a 100644
--- a/lib/Headers/avxintrin.h
+++ b/lib/Headers/avxintrin.h
@@ -2117,7 +2117,7 @@ _mm256_cvtps_pd(__m128 __a)
 static __inline __m128i __DEFAULT_FN_ATTRS
 _mm256_cvttpd_epi32(__m256d __a)
 {
-  return (__m128i)__builtin_convertvector((__v4df) __a, __v4si);
+  return (__m128i)__builtin_ia32_cvttpd2dq256((__v4df) __a);
 }
 
 static __inline __m128i __DEFAULT_FN_ATTRS
@@ -2129,7 +2129,7 @@ _mm256_cvtpd_epi32(__m256d __a)
 static __inline __m256i __DEFAULT_FN_ATTRS
 _mm256_cvttps_epi32(__m256 __a)
 {
-  return (__m256i)__builtin_convertvector((__v8sf) __a, __v8si);
+  return (__m256i)__builtin_ia32_cvttps2dq256((__v8sf) __a);
 }
 
 static __inline double __DEFAULT_FN_ATTRS
diff --git a/lib/Headers/cpuid.h b/lib/Headers/cpuid.h
index 5da02e0e51521..400dcfacd552c 100644
--- a/lib/Headers/cpuid.h
+++ b/lib/Headers/cpuid.h
@@ -82,6 +82,7 @@
 /* Features in %ecx for level 1 */
 #define bit_SSE3        0x00000001
 #define bit_PCLMULQDQ   0x00000002
+#define bit_PCLMUL      bit_PCLMULQDQ   /* for gcc compat */
 #define bit_DTES64      0x00000004
 #define bit_MONITOR     0x00000008
 #define bit_DSCPL       0x00000010
@@ -98,15 +99,19 @@
 #define bit_PCID        0x00020000
 #define bit_DCA         0x00040000
 #define bit_SSE41       0x00080000
+#define bit_SSE4_1      bit_SSE41       /* for gcc compat */
 #define bit_SSE42       0x00100000
+#define bit_SSE4_2      bit_SSE42       /* for gcc compat */
 #define bit_x2APIC      0x00200000
 #define bit_MOVBE       0x00400000
 #define bit_POPCNT      0x00800000
 #define bit_TSCDeadline 0x01000000
 #define bit_AESNI       0x02000000
+#define bit_AES         bit_AESNI       /* for gcc compat */
 #define bit_XSAVE       0x04000000
 #define bit_OSXSAVE     0x08000000
 #define bit_AVX         0x10000000
+#define bit_F16C        0x20000000
 #define bit_RDRND       0x40000000
 
 /* Features in %edx for level 1 */
@@ -119,6 +124,7 @@
 #define bit_PAE         0x00000040
 #define bit_MCE         0x00000080
 #define bit_CX8         0x00000100
+#define bit_CMPXCHG8B   bit_CX8         /* for gcc compat */
 #define bit_APIC        0x00000200
 #define bit_SEP         0x00000800
 #define bit_MTRR        0x00001000
@@ -133,7 +139,7 @@
 #define bit_ACPI        0x00400000
 #define bit_MMX         0x00800000
 #define bit_FXSR        0x01000000
-#define bit_FXSAVE      bit_FXSR    /* for gcc compat */
+#define bit_FXSAVE      bit_FXSR        /* for gcc compat */
 #define bit_SSE         0x02000000
 #define bit_SSE2        0x04000000
 #define bit_SS          0x08000000
diff --git a/lib/Headers/emmintrin.h b/lib/Headers/emmintrin.h
index c78d059f442bf..70d6d726110af 100644
--- a/lib/Headers/emmintrin.h
+++ b/lib/Headers/emmintrin.h
@@ -417,8 +417,7 @@ _mm_cvtsd_si32(__m128d __a)
 static __inline__ __m128 __DEFAULT_FN_ATTRS
 _mm_cvtsd_ss(__m128 __a, __m128d __b)
 {
-  __a[0] = __b[0];
-  return __a;
+  return (__m128)__builtin_ia32_cvtsd2ss((__v4sf)__a, (__v2df)__b);
 }
 
 static __inline__ __m128d __DEFAULT_FN_ATTRS
@@ -444,7 +443,7 @@ _mm_cvttpd_epi32(__m128d __a)
 static __inline__ int __DEFAULT_FN_ATTRS
 _mm_cvttsd_si32(__m128d __a)
 {
-  return __a[0];
+  return __builtin_ia32_cvttsd2si((__v2df)__a);
 }
 
 static __inline__ __m64 __DEFAULT_FN_ATTRS
@@ -1707,7 +1706,7 @@ _mm_cvtsd_si64(__m128d __a)
 static __inline__ long long __DEFAULT_FN_ATTRS
 _mm_cvttsd_si64(__m128d __a)
 {
-  return __a[0];
+  return __builtin_ia32_cvttsd2si64((__v2df)__a);
 }
 #endif
 
@@ -1755,7 +1754,7 @@ _mm_cvtps_epi32(__m128 __a)
 static __inline__ __m128i __DEFAULT_FN_ATTRS
 _mm_cvttps_epi32(__m128 __a)
 {
-  return (__m128i)__builtin_convertvector((__v4sf)__a, __v4si);
+  return (__m128i)__builtin_ia32_cvttps2dq((__v4sf)__a);
 }
 
 /// \brief Returns a vector of [4 x i32] where the lowest element is the input
diff --git a/lib/Headers/xmmintrin.h b/lib/Headers/xmmintrin.h
index 3110e8babf946..99cddb0fac82b 100644
--- a/lib/Headers/xmmintrin.h
+++ b/lib/Headers/xmmintrin.h
@@ -1350,7 +1350,7 @@ _mm_cvt_ps2pi(__m128 __a)
 static __inline__ int __DEFAULT_FN_ATTRS
 _mm_cvttss_si32(__m128 __a)
 {
-  return __a[0];
+  return __builtin_ia32_cvttss2si((__v4sf)__a);
 }
 
 /// \brief Converts a float value contained in the lower 32 bits of a vector of
@@ -1386,7 +1386,7 @@ _mm_cvtt_ss2si(__m128 __a)
 static __inline__ long long __DEFAULT_FN_ATTRS
 _mm_cvttss_si64(__m128 __a)
 {
-  return __a[0];
+  return __builtin_ia32_cvttss2si64((__v4sf)__a);
 }
 
 /// \brief Converts two low-order float values in a 128-bit vector of
diff --git a/lib/Lex/Pragma.cpp b/lib/Lex/Pragma.cpp
index 1819f4f06bc53..3bdd31b26ff8b 100644
--- a/lib/Lex/Pragma.cpp
+++ b/lib/Lex/Pragma.cpp
@@ -354,7 +354,9 @@ void Preprocessor::HandleMicrosoft__pragma(Token &Tok) {
 /// HandlePragmaOnce - Handle \#pragma once.  OnceTok is the 'once'.
 ///
 void Preprocessor::HandlePragmaOnce(Token &OnceTok) {
-  if (isInPrimaryFile()) {
+  // Don't honor the 'once' when handling the primary source file, unless
+  // this is a prefix to a TU, which indicates we're generating a PCH file.
+  if (isInPrimaryFile() && TUKind != TU_Prefix) {
     Diag(OnceTok, diag::pp_pragma_once_in_main_file);
     return;
   }
diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp
index 47d1326b79895..3e87a73aafe89 100644
--- a/lib/Parse/ParseExpr.cpp
+++ b/lib/Parse/ParseExpr.cpp
@@ -447,14 +447,15 @@ Parser::ParseRHSOfBinaryExpression(ExprResult LHS, prec::Level MinPrec) {
         LHS = Actions.ActOnBinOp(getCurScope(), OpToken.getLocation(),
                                  OpToken.getKind(), LHS.get(), RHS.get());
 
-        // In this case, ActOnBinOp performed the CorrectDelayedTyposInExpr check.
-        if (!getLangOpts().CPlusPlus)
-          continue;
       } else {
         LHS = Actions.ActOnConditionalOp(OpToken.getLocation(), ColonLoc,
                                          LHS.get(), TernaryMiddle.get(),
                                          RHS.get());
       }
+      // In this case, ActOnBinOp or ActOnConditionalOp performed the
+      // CorrectDelayedTyposInExpr check.
+      if (!getLangOpts().CPlusPlus)
+        continue;
     }
     // Ensure potential typos aren't left undiagnosed.
     if (LHS.isInvalid()) {
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index b09d7dbc12fc3..85c1301fc9678 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -1053,58 +1053,6 @@ bool Parser::TryParseLambdaIntroducer(LambdaIntroducer &Intro) {
   return false;
 }
 
-static void
-tryConsumeMutableOrConstexprToken(Parser &P, SourceLocation &MutableLoc,
-                                  SourceLocation &ConstexprLoc,
-                                  SourceLocation &DeclEndLoc) {
-  assert(MutableLoc.isInvalid());
-  assert(ConstexprLoc.isInvalid());
-  // Consume constexpr-opt mutable-opt in any sequence, and set the DeclEndLoc
-  // to the final of those locations. Emit an error if we have multiple
-  // copies of those keywords and recover.
-
-  while (true) {
-    switch (P.getCurToken().getKind()) {
-    case tok::kw_mutable: {
-      if (MutableLoc.isValid()) {
-        P.Diag(P.getCurToken().getLocation(),
-               diag::err_lambda_decl_specifier_repeated)
-            << 0 << FixItHint::CreateRemoval(P.getCurToken().getLocation());
-      }
-      MutableLoc = P.ConsumeToken();
-      DeclEndLoc = MutableLoc;
-      break /*switch*/;
-    }
-    case tok::kw_constexpr:
-      if (ConstexprLoc.isValid()) {
-        P.Diag(P.getCurToken().getLocation(),
-               diag::err_lambda_decl_specifier_repeated)
-            << 1 << FixItHint::CreateRemoval(P.getCurToken().getLocation());
-      }
-      ConstexprLoc = P.ConsumeToken();
-      DeclEndLoc = ConstexprLoc;
-      break /*switch*/;
-    default:
-      return;
-    }
-  }
-}
-
-static void
-addConstexprToLambdaDeclSpecifier(Parser &P, SourceLocation ConstexprLoc,
-                                  DeclSpec &DS) {
-  if (ConstexprLoc.isValid()) {
-    P.Diag(ConstexprLoc, !P.getLangOpts().CPlusPlus1z
-                             ? diag::ext_constexpr_on_lambda_cxx1z
-                             : diag::warn_cxx14_compat_constexpr_on_lambda);
-    const char *PrevSpec = nullptr;
-    unsigned DiagID = 0;
-    DS.SetConstexprSpec(ConstexprLoc, PrevSpec, DiagID);
-    assert(PrevSpec == nullptr && DiagID == 0 &&
-           "Constexpr cannot have been set previously!");
-  }
-}
-
 /// ParseLambdaExpressionAfterIntroducer - Parse the rest of a lambda
 /// expression.
 ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
@@ -1163,13 +1111,10 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
     // compatible with MSVC.
     MaybeParseMicrosoftDeclSpecs(Attr, &DeclEndLoc);
 
-    // Parse mutable-opt and/or constexpr-opt, and update the DeclEndLoc.
+    // Parse 'mutable'[opt].
     SourceLocation MutableLoc;
-    SourceLocation ConstexprLoc;
-    tryConsumeMutableOrConstexprToken(*this, MutableLoc, ConstexprLoc,
-                                      DeclEndLoc);
-    
-    addConstexprToLambdaDeclSpecifier(*this, ConstexprLoc, DS);
+    if (TryConsumeToken(tok::kw_mutable, MutableLoc))
+      DeclEndLoc = MutableLoc;
 
     // Parse exception-specification[opt].
     ExceptionSpecificationType ESpecType = EST_None;
@@ -1227,8 +1172,7 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
                                            LParenLoc, FunLocalRangeEnd, D,
                                            TrailingReturnType),
                   Attr, DeclEndLoc);
-  } else if (Tok.isOneOf(tok::kw_mutable, tok::arrow, tok::kw___attribute,
-                         tok::kw_constexpr) ||
+  } else if (Tok.isOneOf(tok::kw_mutable, tok::arrow, tok::kw___attribute) ||
              (Tok.is(tok::l_square) && NextToken().is(tok::l_square))) {
     // It's common to forget that one needs '()' before 'mutable', an attribute
     // specifier, or the result type. Deal with this.
@@ -1238,7 +1182,6 @@ ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
     case tok::arrow: TokKind = 1; break;
     case tok::kw___attribute:
     case tok::l_square: TokKind = 2; break;
-    case tok::kw_constexpr: TokKind = 3; break;
     default: llvm_unreachable("Unknown token kind");
     }
 
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 0c25e01787c12..b8e7ede2716c9 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -6523,6 +6523,12 @@ CheckReturnStackAddr(Sema &S, Expr *RetValExp, QualType lhsType,
   if (!stackE)
     return; // Nothing suspicious was found.
 
+  // Parameters are initalized in the calling scope, so taking the address
+  // of a parameter reference doesn't need a warning.
+  for (auto *DRE : refVars)
+    if (isa<ParmVarDecl>(DRE->getDecl()))
+      return;
+
   SourceLocation diagLoc;
   SourceRange diagRange;
   if (refVars.empty()) {
@@ -6546,6 +6552,13 @@ CheckReturnStackAddr(Sema &S, Expr *RetValExp, QualType lhsType,
   } else if (isa<AddrLabelExpr>(stackE)) { // address of label.
     S.Diag(diagLoc, diag::warn_ret_addr_label) << diagRange;
   } else { // local temporary.
+    // If there is an LValue->RValue conversion, then the value of the
+    // reference type is used, not the reference.
+    if (auto *ICE = dyn_cast<ImplicitCastExpr>(RetValExp)) {
+      if (ICE->getCastKind() == CK_LValueToRValue) {
+        return;
+      }
+    }
     S.Diag(diagLoc, diag::warn_ret_local_temp_addr_ref)
      << lhsType->isReferenceType() << diagRange;
   }
@@ -7776,6 +7789,12 @@ bool AnalyzeBitFieldAssignment(Sema &S, FieldDecl *Bitfield, Expr *Init,
   unsigned OriginalWidth = Value.getBitWidth();
   unsigned FieldWidth = Bitfield->getBitWidthValue(S.Context);
 
+  if (Value.isSigned() && Value.isNegative())
+    if (UnaryOperator *UO = dyn_cast<UnaryOperator>(OriginalInit))
+      if (UO->getOpcode() == UO_Minus)
+        if (isa<IntegerLiteral>(UO->getSubExpr()))
+          OriginalWidth = Value.getMinSignedBits();
+
   if (OriginalWidth <= FieldWidth)
     return false;
 
@@ -9372,7 +9391,8 @@ void Sema::CheckUnsequencedOperations(Expr *E) {
 void Sema::CheckCompletedExpr(Expr *E, SourceLocation CheckLoc,
                               bool IsConstexpr) {
   CheckImplicitConversions(E, CheckLoc);
-  CheckUnsequencedOperations(E);
+  if (!E->isInstantiationDependent())
+    CheckUnsequencedOperations(E);
   if (!IsConstexpr && !E->isValueDependent())
     CheckForIntOverflow(E);
 }
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 2cd00f8218a67..b7a968e09d4d6 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -961,32 +961,26 @@ static QualType adjustCVQualifiersForCXXThisWithinLambda(
 QualType Sema::getCurrentThisType() {
   DeclContext *DC = getFunctionLevelDeclContext();
   QualType ThisTy = CXXThisTypeOverride;
+
   if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
     if (method && method->isInstance())
       ThisTy = method->getThisType(Context);
   }
-  if (ThisTy.isNull()) {
-    if (isGenericLambdaCallOperatorSpecialization(CurContext) &&
-        CurContext->getParent()->getParent()->isRecord()) {
-      // This is a generic lambda call operator that is being instantiated
-      // within a default initializer - so use the enclosing class as 'this'.
-      // There is no enclosing member function to retrieve the 'this' pointer
-      // from.
 
-      // FIXME: This looks wrong. If we're in a lambda within a lambda within a
-      // default member initializer, we need to recurse up more parents to find
-      // the right context. Looks like we should be walking up to the parent of
-      // the closure type, checking whether that is itself a lambda, and if so,
-      // recursing, until we reach a class or a function that isn't a lambda
-      // call operator. And we should accumulate the constness of *this on the
-      // way.
+  if (ThisTy.isNull() && isLambdaCallOperator(CurContext) &&
+      !ActiveTemplateInstantiations.empty()) {
 
-      QualType ClassTy = Context.getTypeDeclType(
-          cast<CXXRecordDecl>(CurContext->getParent()->getParent()));
-      // There are no cv-qualifiers for 'this' within default initializers, 
-      // per [expr.prim.general]p4.
-      ThisTy = Context.getPointerType(ClassTy);
-    }
+    assert(isa<CXXRecordDecl>(DC) &&
+           "Trying to get 'this' type from static method?");
+
+    // This is a lambda call operator that is being instantiated as a default
+    // initializer. DC must point to the enclosing class type, so we can recover
+    // the 'this' type from it.
+
+    QualType ClassTy = Context.getTypeDeclType(cast<CXXRecordDecl>(DC));
+    // There are no cv-qualifiers for 'this' within default initializers,
+    // per [expr.prim.general]p4.
+    ThisTy = Context.getPointerType(ClassTy);
   }
 
   // If we are within a lambda's call operator, the cv-qualifiers of 'this'
diff --git a/lib/Sema/SemaLambda.cpp b/lib/Sema/SemaLambda.cpp
index 1b8410d7f4b97..8a2bf929dfc0e 100644
--- a/lib/Sema/SemaLambda.cpp
+++ b/lib/Sema/SemaLambda.cpp
@@ -355,8 +355,7 @@ CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
                                            SourceRange IntroducerRange,
                                            TypeSourceInfo *MethodTypeInfo,
                                            SourceLocation EndLoc,
-                                           ArrayRef<ParmVarDecl *> Params,
-                                           const bool IsConstexprSpecified) {
+                                           ArrayRef<ParmVarDecl *> Params) {
   QualType MethodType = MethodTypeInfo->getType();
   TemplateParameterList *TemplateParams = 
             getGenericLambdaTemplateParameterList(getCurLambda(), *this);
@@ -393,7 +392,7 @@ CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
                             MethodType, MethodTypeInfo,
                             SC_None,
                             /*isInline=*/true,
-                            IsConstexprSpecified,
+                            /*isConstExpr=*/false,
                             EndLoc);
   Method->setAccess(AS_public);
   
@@ -878,9 +877,8 @@ void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
   CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
                                                  KnownDependent, Intro.Default);
 
-  CXXMethodDecl *Method =
-      startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
-                            ParamInfo.getDeclSpec().isConstexprSpecified());
+  CXXMethodDecl *Method = startLambdaDefinition(Class, Intro.Range,
+                                                MethodTyInfo, EndLoc, Params);
   if (ExplicitParams)
     CheckCXXDefaultArguments(Method);
   
@@ -1599,17 +1597,6 @@ ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
                                           CaptureInits, ArrayIndexVars, 
                                           ArrayIndexStarts, EndLoc,
                                           ContainsUnexpandedParameterPack);
-  // If the lambda expression's call operator is not explicitly marked constexpr
-  // and we are not in a dependent context, analyze the call operator to infer
-  // its constexpr-ness, supressing diagnostics while doing so.
-  if (getLangOpts().CPlusPlus1z && !CallOperator->isInvalidDecl() &&
-      !CallOperator->isConstexpr() &&
-      !Class->getDeclContext()->isDependentContext()) {
-    TentativeAnalysisScope DiagnosticScopeGuard(*this);
-    CallOperator->setConstexpr(
-        CheckConstexprFunctionDecl(CallOperator) &&
-        CheckConstexprFunctionBody(CallOperator, CallOperator->getBody()));
-  }
 
   if (!CurContext->isDependentContext()) {
     switch (ExprEvalContexts.back().Context) {
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index b025a397edca0..40d6e910f1fb3 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -5975,8 +5975,12 @@ EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
   SmallVector<Expr *, 16> ConvertedArgs;
   bool InitializationFailed = false;
 
+  // Ignore any variadic parameters. Converting them is pointless, since the
+  // user can't refer to them in the enable_if condition.
+  unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
+
   // Convert the arguments.
-  for (unsigned I = 0, E = Args.size(); I != E; ++I) {
+  for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
     ExprResult R;
     if (I == 0 && !MissingImplicitThis && isa<CXXMethodDecl>(Function) &&
         !cast<CXXMethodDecl>(Function)->isStatic() &&
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index 36859f61d3871..7224eef848dee 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -10222,9 +10222,7 @@ TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) {
   CXXMethodDecl *NewCallOperator = getSema().startLambdaDefinition(
       Class, E->getIntroducerRange(), NewCallOpTSI,
       E->getCallOperator()->getLocEnd(),
-      NewCallOpTSI->getTypeLoc().castAs<FunctionProtoTypeLoc>().getParams(),
-      E->getCallOperator()->isConstexpr());
-
+      NewCallOpTSI->getTypeLoc().castAs<FunctionProtoTypeLoc>().getParams());
   LSI->CallOperator = NewCallOperator;
 
   getDerived().transformAttrs(E->getCallOperator(), NewCallOperator);
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index b35bd7bd329b4..9d1554a826aaf 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -8637,6 +8637,7 @@ void ASTReader::FinishedDeserializing() {
       auto Updates = std::move(PendingExceptionSpecUpdates);
       PendingExceptionSpecUpdates.clear();
       for (auto Update : Updates) {
+        ProcessingUpdatesRAIIObj ProcessingUpdates(*this);
         auto *FPT = Update.second->getType()->castAs<FunctionProtoType>();
         auto ESI = FPT->getExtProtoInfo().ExceptionSpec;
         if (auto *Listener = Context.getASTMutationListener())
@@ -8707,6 +8708,7 @@ ASTReader::ASTReader(
       AllowConfigurationMismatch(AllowConfigurationMismatch),
       ValidateSystemInputs(ValidateSystemInputs),
       UseGlobalIndex(UseGlobalIndex), TriedLoadingGlobalIndex(false),
+      ProcessingUpdateRecords(false),
       CurrSwitchCaseStmts(&SwitchCaseStmts), NumSLocEntriesRead(0),
       TotalNumSLocEntries(0), NumStatementsRead(0), TotalNumStatements(0),
       NumMacrosRead(0), TotalNumMacros(0), NumIdentifierLookups(0),
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 4fd7aeb83ac1f..d38a701c04b5a 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -3484,6 +3484,7 @@ void ASTReader::loadDeclUpdateRecords(serialization::DeclID ID, Decl *D) {
   // The declaration may have been modified by files later in the chain.
   // If this is the case, read the record containing the updates from each file
   // and pass it to ASTDeclReader to make the modifications.
+  ProcessingUpdatesRAIIObj ProcessingUpdates(*this);
   DeclUpdateOffsetsMap::iterator UpdI = DeclUpdateOffsets.find(ID);
   if (UpdI != DeclUpdateOffsets.end()) {
     auto UpdateOffsets = std::move(UpdI->second);
@@ -3902,11 +3903,8 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
     }
 
     case UPD_DECL_MARKED_USED: {
-      // FIXME: This doesn't send the right notifications if there are
-      // ASTMutationListeners other than an ASTWriter.
-
       // Maintain AST consistency: any later redeclarations are used too.
-      D->setIsUsed();
+      D->markUsed(Reader.Context);
       break;
     }
 
@@ -3930,11 +3928,8 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
         Exported = TD->getDefinition();
       Module *Owner = SubmoduleID ? Reader.getSubmodule(SubmoduleID) : nullptr;
       if (Reader.getContext().getLangOpts().ModulesLocalVisibility) {
-        // FIXME: This doesn't send the right notifications if there are
-        // ASTMutationListeners other than an ASTWriter.
-        Reader.getContext().mergeDefinitionIntoModule(
-            cast<NamedDecl>(Exported), Owner,
-            /*NotifyListeners*/ false);
+        Reader.getContext().mergeDefinitionIntoModule(cast<NamedDecl>(Exported),
+                                                      Owner);
         Reader.PendingMergedDefinitionsToDeduplicate.insert(
             cast<NamedDecl>(Exported));
       } else if (Owner && Owner->NameVisibility != Module::AllVisible) {
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index bb6a8ae8f6283..7589b0c5dd528 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -5637,6 +5637,7 @@ void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
 }
 
 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(D->isCompleteDefinition());
   assert(!WritingAST && "Already writing the AST!");
   if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
@@ -5663,7 +5664,8 @@ static bool isImportedDeclContext(ASTReader *Chain, const Decl *D) {
 }
 
 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
-   assert(DC->isLookupContext() &&
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
+  assert(DC->isLookupContext() &&
           "Should not add lookup results to non-lookup contexts!");
 
   // TU is handled elsewhere.
@@ -5697,6 +5699,7 @@ void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
 }
 
 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(D->isImplicit());
 
   // We're only interested in cases where a local declaration is added to an
@@ -5714,6 +5717,7 @@ void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
 }
 
 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!DoneWritingDeclsAndTypes && "Already done writing updates!");
   if (!Chain) return;
   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
@@ -5728,6 +5732,7 @@ void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
 }
 
 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!Chain) return;
   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
@@ -5738,6 +5743,7 @@ void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
 
 void ASTWriter::ResolvedOperatorDelete(const CXXDestructorDecl *DD,
                                        const FunctionDecl *Delete) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   assert(Delete && "Not given an operator delete");
   if (!Chain) return;
@@ -5747,6 +5753,7 @@ void ASTWriter::ResolvedOperatorDelete(const CXXDestructorDecl *DD,
 }
 
 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!D->isFromASTFile())
     return; // Declaration not imported from PCH.
@@ -5756,6 +5763,7 @@ void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
 }
 
 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!D->isFromASTFile())
     return;
@@ -5764,6 +5772,7 @@ void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
 }
 
 void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!D->isFromASTFile())
     return;
@@ -5776,6 +5785,7 @@ void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
 }
 
 void ASTWriter::DefaultArgumentInstantiated(const ParmVarDecl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!D->isFromASTFile())
     return;
@@ -5786,6 +5796,7 @@ void ASTWriter::DefaultArgumentInstantiated(const ParmVarDecl *D) {
 
 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
                                              const ObjCInterfaceDecl *IFD) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!IFD->isFromASTFile())
     return; // Declaration not imported from PCH.
@@ -5796,6 +5807,7 @@ void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
 }
 
 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
 
   // If there is *any* declaration of the entity that's not from an AST file,
@@ -5809,6 +5821,7 @@ void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
 }
 
 void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!D->isFromASTFile())
     return;
@@ -5818,6 +5831,7 @@ void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
 
 void ASTWriter::DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
                                                      const Attr *Attr) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!D->isFromASTFile())
     return;
@@ -5827,6 +5841,7 @@ void ASTWriter::DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
 }
 
 void ASTWriter::RedefinedHiddenDefinition(const NamedDecl *D, Module *M) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   assert(D->isHidden() && "expected a hidden declaration");
   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_EXPORTED, M));
@@ -5834,6 +5849,7 @@ void ASTWriter::RedefinedHiddenDefinition(const NamedDecl *D, Module *M) {
 
 void ASTWriter::AddedAttributeToRecord(const Attr *Attr,
                                        const RecordDecl *Record) {
+  if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
   if (!Record->isFromASTFile())
     return;