Revert "Remove redundant "std::move"s in return statements"

The build failed with

  error: call to deleted constructor of 'llvm::Error'

errors.

This reverts commit 1c2241a7936bf85aa68aef94bd40c3ba77d8ddf2.

include/llvm/Bitstream/BitstreamReader.h

@@ -209,7 +209,7 @@ public:
     unsigned BitsLeft = NumBits - BitsInCurWord;
 
     if (Error fillResult = fillCurWord())
-      return fillResult;
+      return std::move(fillResult);
 
     // If we run out of data, abort.
     if (BitsLeft > BitsInCurWord)
@@ -425,7 +425,7 @@ public:
         // We read and accumulate abbrev's, the client can't do anything with
         // them anyway.
         if (Error Err = ReadAbbrevRecord())
-          return Err;
+          return std::move(Err);
         continue;
       }
 
@@ -448,7 +448,7 @@ public:
 
       // If we found a sub-block, just skip over it and check the next entry.
       if (Error Err = SkipBlock())
-        return Err;
+        return std::move(Err);
     }
   }
 

include/llvm/DebugInfo/CodeView/CVRecord.h

@@ -100,14 +100,14 @@ inline Expected<CVRecord<Kind>> readCVRecordFromStream(BinaryStreamRef Stream,
   Reader.setOffset(Offset);
 
   if (auto EC = Reader.readObject(Prefix))
-    return EC;
+    return std::move(EC);
   if (Prefix->RecordLen < 2)
     return make_error<CodeViewError>(cv_error_code::corrupt_record);
 
   Reader.setOffset(Offset);
   ArrayRef<uint8_t> RawData;
   if (auto EC = Reader.readBytes(RawData, Prefix->RecordLen + sizeof(uint16_t)))
-    return EC;
+    return std::move(EC);
   return codeview::CVRecord<Kind>(RawData);
 }
 

include/llvm/DebugInfo/CodeView/SymbolDeserializer.h

@@ -48,7 +48,7 @@ public:
   template <typename T> static Expected<T> deserializeAs(CVSymbol Symbol) {
     T Record(static_cast<SymbolRecordKind>(Symbol.kind()));
     if (auto EC = deserializeAs<T>(Symbol, Record))
-      return EC;
+      return std::move(EC);
     return Record;
   }
 

include/llvm/DebugInfo/CodeView/TypeDeserializer.h

@@ -60,7 +60,7 @@ public:
     T Record(K);
     CVType CVT(Data);
     if (auto EC = deserializeAs<T>(CVT, Record))
-      return EC;
+      return std::move(EC);
     return Record;
   }
 

include/llvm/DebugInfo/DWARF/DWARFListTable.h

@@ -280,7 +280,7 @@ DWARFListTableBase<DWARFListType>::findList(DWARFDataExtractor Data,
   if (Error E =
           List.extract(Data, getHeaderOffset(), End, &Offset,
                        Header.getSectionName(), Header.getListTypeString()))
-    return E;
+    return std::move(E);
   ListMap[StartingOffset] = List;
   return List;
 }

include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h

@@ -233,7 +233,7 @@ private:
         if (auto Sym = BaseLayer.findSymbolIn(BLK, Name, ExportedSymbolsOnly))
           return Sym;
         else if (auto Err = Sym.takeError())
-          return Err;
+          return std::move(Err);
       return nullptr;
     }
 
@@ -342,7 +342,7 @@ public:
               findSymbolIn(KV.first, std::string(Name), ExportedSymbolsOnly))
         return Sym;
       else if (auto Err = Sym.takeError())
-        return Err;
+        return std::move(Err);
     }
     return BaseLayer.findSymbol(std::string(Name), ExportedSymbolsOnly);
   }
@@ -518,7 +518,7 @@ private:
       if (auto Sym = LD.findSymbol(BaseLayer, std::string(Name), false))
         return Sym;
       else if (auto Err = Sym.takeError())
-        return Err;
+        return std::move(Err);
 
       return nullptr;
     };
@@ -611,7 +611,7 @@ private:
           } else
             return FnBodyAddrOrErr.takeError();
         } else if (auto Err = FnBodySym.takeError())
-          return Err;
+          return std::move(Err);
         else
           llvm_unreachable("Function not emitted for partition");
       }
@@ -729,7 +729,7 @@ private:
     SetSymbolResolver(K, std::move(Resolver));
 
     if (auto Err = BaseLayer.addModule(std::move(K), std::move(M)))
-      return Err;
+      return std::move(Err);
 
     return K;
   }

include/llvm/ExecutionEngine/Orc/IndirectionUtils.h

@@ -80,8 +80,8 @@ public:
         new LocalTrampolinePool(std::move(GetTrampolineLanding), Err));
 
     if (Err)
-      return Err;
-    return LTP;
+      return std::move(Err);
+    return std::move(LTP);
   }
 
   /// Get a free trampoline. Returns an error if one can not be provided (e.g.
@@ -90,7 +90,7 @@ public:
     std::lock_guard<std::mutex> Lock(LTPMutex);
     if (AvailableTrampolines.empty()) {
       if (auto Err = grow())
-        return Err;
+        return std::move(Err);
     }
     assert(!AvailableTrampolines.empty() && "Failed to grow trampoline pool");
     auto TrampolineAddr = AvailableTrampolines.back();
@@ -229,8 +229,8 @@ public:
     auto CCMgr = std::unique_ptr<LocalJITCompileCallbackManager>(
         new LocalJITCompileCallbackManager(ES, ErrorHandlerAddress, Err));
     if (Err)
-      return Err;
-    return CCMgr;
+      return std::move(Err);
+    return std::move(CCMgr);
   }
 
 private:

include/llvm/ExecutionEngine/Orc/LLJIT.h

@@ -262,13 +262,13 @@ public:
   /// Create an instance of the JIT.
   Expected<std::unique_ptr<JITType>> create() {
     if (auto Err = impl().prepareForConstruction())
-      return Err;
+      return std::move(Err);
 
     Error Err = Error::success();
     std::unique_ptr<JITType> J(new JITType(impl(), Err));
     if (Err)
-      return Err;
-    return J;
+      return std::move(Err);
+    return std::move(J);
   }
 
 protected:

include/llvm/ExecutionEngine/Orc/LazyEmittingLayer.h

@@ -57,13 +57,13 @@ private:
             else if (this->EmitState == NotEmitted) {
               this->EmitState = Emitting;
               if (auto Err = this->emitToBaseLayer(B))
-                return Err;
+                return std::move(Err);
               this->EmitState = Emitted;
             }
             if (auto Sym = B.findSymbolIn(K, Name, ExportedSymbolsOnly))
               return Sym.getAddress();
             else if (auto Err = Sym.takeError())
-              return Err;
+              return std::move(Err);
             else
               llvm_unreachable("Successful symbol lookup should return "
                                "definition address here");

include/llvm/ExecutionEngine/Orc/LazyReexports.h

@@ -101,9 +101,9 @@ public:
         new LocalLazyCallThroughManager(ES, ErrorHandlerAddr));
 
     if (auto Err = LLCTM->init<ORCABI>())
-      return Err;
+      return std::move(Err);
 
-    return LLCTM;
+    return std::move(LLCTM);
   }
 };
 

include/llvm/ExecutionEngine/Orc/Legacy.h

@@ -123,7 +123,7 @@ getResponsibilitySetWithLegacyFn(const SymbolNameSet &Symbols,
       if (!Sym.getFlags().isStrong())
         Result.insert(S);
     } else if (auto Err = Sym.takeError())
-      return Err;
+      return std::move(Err);
   }
 
   return Result;

include/llvm/ExecutionEngine/Orc/OrcRemoteTargetClient.h

@@ -457,7 +457,7 @@ public:
       std::lock_guard<std::mutex> Lock(RTPMutex);
       if (AvailableTrampolines.empty()) {
         if (auto Err = grow())
-          return Err;
+          return std::move(Err);
       }
       assert(!AvailableTrampolines.empty() && "Failed to grow trampoline pool");
       auto TrampolineAddr = AvailableTrampolines.back();
@@ -506,8 +506,8 @@ public:
     auto Client = std::unique_ptr<OrcRemoteTargetClient>(
         new OrcRemoteTargetClient(Channel, ES, Err));
     if (Err)
-      return Err;
-    return Client;
+      return std::move(Err);
+    return std::move(Client);
   }
 
   /// Call the int(void) function at the given address in the target and return
@@ -541,7 +541,7 @@ public:
   createRemoteMemoryManager() {
     auto Id = AllocatorIds.getNext();
     if (auto Err = callB<mem::CreateRemoteAllocator>(Id))
-      return Err;
+      return std::move(Err);
     return std::unique_ptr<RemoteRTDyldMemoryManager>(
         new RemoteRTDyldMemoryManager(*this, Id));
   }
@@ -552,7 +552,7 @@ public:
   createIndirectStubsManager() {
     auto Id = IndirectStubOwnerIds.getNext();
     if (auto Err = callB<stubs::CreateIndirectStubsOwner>(Id))
-      return Err;
+      return std::move(Err);
     return std::make_unique<RemoteIndirectStubsManager>(*this, Id);
   }
 
@@ -562,7 +562,7 @@ public:
 
     // Emit the resolver block on the JIT server.
     if (auto Err = callB<stubs::EmitResolverBlock>())
-      return Err;
+      return std::move(Err);
 
     // Create the callback manager.
     CallbackManager.emplace(*this, ES, ErrorHandlerAddress);

include/llvm/ExecutionEngine/Orc/OrcRemoteTargetServer.h

@@ -265,7 +265,7 @@ private:
     typename TargetT::IndirectStubsInfo IS;
     if (auto Err =
             TargetT::emitIndirectStubsBlock(IS, NumStubsRequired, nullptr))
-      return Err;
+      return std::move(Err);
 
     JITTargetAddress StubsBase = static_cast<JITTargetAddress>(
         reinterpret_cast<uintptr_t>(IS.getStub(0)));
@@ -382,7 +382,7 @@ private:
     auto &Allocator = I->second;
     void *LocalAllocAddr = nullptr;
     if (auto Err = Allocator.allocate(LocalAllocAddr, Size, Align))
-      return Err;
+      return std::move(Err);
 
     LLVM_DEBUG(dbgs() << "  Allocator " << Id << " reserved " << LocalAllocAddr
                       << " (" << Size << " bytes, alignment " << Align

include/llvm/ExecutionEngine/Orc/RPC/RPCUtils.h

@@ -1528,20 +1528,20 @@ public:
             Args...)) {
       detail::ResultTraits<typename Func::ReturnType>::consumeAbandoned(
           std::move(Result));
-      return Err;
+      return std::move(Err);
     }
 
     if (auto Err = this->C.send()) {
       detail::ResultTraits<typename Func::ReturnType>::consumeAbandoned(
           std::move(Result));
-      return Err;
+      return std::move(Err);
     }
 
     while (!ReceivedResponse) {
       if (auto Err = this->handleOne()) {
         detail::ResultTraits<typename Func::ReturnType>::consumeAbandoned(
             std::move(Result));
-        return Err;
+        return std::move(Err);
       }
     }
 

include/llvm/ExecutionEngine/Orc/RTDyldObjectLinkingLayer.h

@@ -276,7 +276,7 @@ private:
         // and its execution, so we need to double check.
         if (!this->Finalized)
           if (auto Err = this->finalize())
-            return Err;
+            return std::move(Err);
         return this->getSymbol(Name, false).getAddress();
       };
     }
@@ -430,7 +430,7 @@ public:
       if (auto Sym = KV.second->getSymbol(Name, ExportedSymbolsOnly))
         return Sym;
       else if (auto Err = Sym.takeError())
-        return Err;
+        return std::move(Err);
 
     return nullptr;
   }

include/llvm/Object/ELF.h

@@ -601,7 +601,7 @@ ELFFile<ELFT>::getStringTable(const Elf_Shdr *Section,
                               ": expected SHT_STRTAB, but got " +
                               object::getELFSectionTypeName(
                                   getHeader()->e_machine, Section->sh_type)))
-      return E;
+      return std::move(E);
 
   auto V = getSectionContentsAsArray<char>(Section);
   if (!V)

include/llvm/Object/ELFObjectFile.h

@@ -948,7 +948,7 @@ Expected<ELFObjectFile<ELFT>>
 ELFObjectFile<ELFT>::create(MemoryBufferRef Object) {
   auto EFOrErr = ELFFile<ELFT>::create(Object.getBuffer());
   if (Error E = EFOrErr.takeError())
-    return E;
+    return std::move(E);
   auto EF = std::move(*EFOrErr);
 
   auto SectionsOrErr = EF.sections();

include/llvm/ProfileData/Coverage/CoverageMappingReader.h

@@ -77,7 +77,7 @@ public:
     if (ReadErr != coveragemap_error::success) {
       auto E = make_error<CoverageMapError>(ReadErr);
       ReadErr = coveragemap_error::success;
-      return E;
+      return std::move(E);
     }
     return Record;
   }
@@ -85,7 +85,7 @@ public:
     if (ReadErr != coveragemap_error::success) {
       auto E = make_error<CoverageMapError>(ReadErr);
       ReadErr = coveragemap_error::success;
-      return E;
+      return std::move(E);
     }
     return &Record;
   }

include/llvm/Support/Error.h

@@ -963,7 +963,7 @@ Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
 
   if (auto Err = handleErrors(ValOrErr.takeError(),
                               std::forward<HandlerTs>(Handlers)...))
-    return Err;
+    return std::move(Err);
 
   return RecoveryPath();
 }

include/llvm/Support/TaskQueue.h

@@ -98,7 +98,7 @@ public:
         IsTaskInFlight = true;
       }
     }
-    return F;
+    return std::move(F);
   }
 
 private:

lib/Bitcode/Reader/BitcodeAnalyzer.cpp

@@ -415,41 +415,41 @@ static Expected<CurStreamTypeType> ReadSignature(BitstreamCursor &Stream) {
 
   char Signature[6];
   if (Error Err = tryRead(Signature[0], 8))
-    return Err;
+    return std::move(Err);
   if (Error Err = tryRead(Signature[1], 8))
-    return Err;
+    return std::move(Err);
 
   // Autodetect the file contents, if it is one we know.
   if (Signature[0] == 'C' && Signature[1] == 'P') {
     if (Error Err = tryRead(Signature[2], 8))
-      return Err;
+      return std::move(Err);
     if (Error Err = tryRead(Signature[3], 8))
-      return Err;
+      return std::move(Err);
     if (Signature[2] == 'C' && Signature[3] == 'H')
       return ClangSerializedASTBitstream;
   } else if (Signature[0] == 'D' && Signature[1] == 'I') {
     if (Error Err = tryRead(Signature[2], 8))
-      return Err;
+      return std::move(Err);
     if (Error Err = tryRead(Signature[3], 8))
-      return Err;
+      return std::move(Err);
     if (Signature[2] == 'A' && Signature[3] == 'G')
       return ClangSerializedDiagnosticsBitstream;
   } else if (Signature[0] == 'R' && Signature[1] == 'M') {
     if (Error Err = tryRead(Signature[2], 8))
-      return Err;
+      return std::move(Err);
     if (Error Err = tryRead(Signature[3], 8))
-      return Err;
+      return std::move(Err);
     if (Signature[2] == 'R' && Signature[3] == 'K')
       return LLVMBitstreamRemarks;
   } else {
     if (Error Err = tryRead(Signature[2], 4))
-      return Err;
+      return std::move(Err);
     if (Error Err = tryRead(Signature[3], 4))
-      return Err;
+      return std::move(Err);
     if (Error Err = tryRead(Signature[4], 4))
-      return Err;
+      return std::move(Err);
     if (Error Err = tryRead(Signature[5], 4))
-      return Err;
+      return std::move(Err);
     if (Signature[0] == 'B' && Signature[1] == 'C' && Signature[2] == 0x0 &&
         Signature[3] == 0xC && Signature[4] == 0xE && Signature[5] == 0xD)
       return LLVMIRBitstream;

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -141,9 +141,9 @@ static Expected<BitstreamCursor> initStream(MemoryBufferRef Buffer) {
 
   BitstreamCursor Stream(ArrayRef<uint8_t>(BufPtr, BufEnd));
   if (Error Err = hasInvalidBitcodeHeader(Stream))
-    return Err;
+    return std::move(Err);
 
-  return Stream;
+  return std::move(Stream);
 }
 
 /// Convert a string from a record into an std::string, return true on failure.
@@ -172,7 +172,7 @@ static void stripTBAA(Module *M) {
 /// "epoch" encoded in the bitcode, and return the producer name if any.
 static Expected<std::string> readIdentificationBlock(BitstreamCursor &Stream) {
   if (Error Err = Stream.EnterSubBlock(bitc::IDENTIFICATION_BLOCK_ID))
-    return Err;
+    return std::move(Err);
 
   // Read all the records.
   SmallVector<uint64_t, 64> Record;
@@ -244,7 +244,7 @@ static Expected<std::string> readIdentificationCode(BitstreamCursor &Stream) {
 
       // Ignore other sub-blocks.
       if (Error Err = Stream.SkipBlock())
-        return Err;
+        return std::move(Err);
       continue;
     case BitstreamEntry::Record:
       if (Expected<unsigned> Skipped = Stream.skipRecord(Entry.ID))
@@ -257,7 +257,7 @@ static Expected<std::string> readIdentificationCode(BitstreamCursor &Stream) {
 
 static Expected<bool> hasObjCCategoryInModule(BitstreamCursor &Stream) {
   if (Error Err = Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
-    return Err;
+    return std::move(Err);
 
   SmallVector<uint64_t, 64> Record;
   // Read all the records for this module.
@@ -324,7 +324,7 @@ static Expected<bool> hasObjCCategory(BitstreamCursor &Stream) {
 
       // Ignore other sub-blocks.
       if (Error Err = Stream.SkipBlock())
-        return Err;
+        return std::move(Err);
       continue;
 
     case BitstreamEntry::Record:
@@ -338,7 +338,7 @@ static Expected<bool> hasObjCCategory(BitstreamCursor &Stream) {
 
 static Expected<std::string> readModuleTriple(BitstreamCursor &Stream) {
   if (Error Err = Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
-    return Err;
+    return std::move(Err);
 
   SmallVector<uint64_t, 64> Record;
 
@@ -402,7 +402,7 @@ static Expected<std::string> readTriple(BitstreamCursor &Stream) {
 
       // Ignore other sub-blocks.
       if (Error Err = Stream.SkipBlock())
-        return Err;
+        return std::move(Err);
       continue;
 
     case BitstreamEntry::Record:
@@ -2044,7 +2044,7 @@ static Expected<uint64_t> jumpToValueSymbolTable(uint64_t Offset,
   // of the VST read.
   uint64_t CurrentBit = Stream.GetCurrentBitNo();
   if (Error JumpFailed = Stream.JumpToBit(Offset * 32))
-    return JumpFailed;
+    return std::move(JumpFailed);
   Expected<BitstreamEntry> MaybeEntry = Stream.advance();
   if (!MaybeEntry)
     return MaybeEntry.takeError();
@@ -6293,7 +6293,7 @@ const std::error_category &llvm::BitcodeErrorCategory() {
 static Expected<StringRef> readBlobInRecord(BitstreamCursor &Stream,
                                             unsigned Block, unsigned RecordID) {
   if (Error Err = Stream.EnterSubBlock(Block))
-    return Err;
+    return std::move(Err);
 
   StringRef Strtab;
   while (true) {
@@ -6311,7 +6311,7 @@ static Expected<StringRef> readBlobInRecord(BitstreamCursor &Stream,
 
     case BitstreamEntry::SubBlock:
       if (Error Err = Stream.SkipBlock())
-        return Err;
+        return std::move(Err);
       break;
 
     case BitstreamEntry::Record:
@@ -6372,7 +6372,7 @@ llvm::getBitcodeFileContents(MemoryBufferRef Buffer) {
       if (Entry.ID == bitc::IDENTIFICATION_BLOCK_ID) {
         IdentificationBit = Stream.GetCurrentBitNo() - BCBegin * 8;
         if (Error Err = Stream.SkipBlock())
-          return Err;
+          return std::move(Err);
 
         {
           Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
@@ -6389,7 +6389,7 @@ llvm::getBitcodeFileContents(MemoryBufferRef Buffer) {
       if (Entry.ID == bitc::MODULE_BLOCK_ID) {
         uint64_t ModuleBit = Stream.GetCurrentBitNo() - BCBegin * 8;
         if (Error Err = Stream.SkipBlock())
-          return Err;
+          return std::move(Err);
 
         F.Mods.push_back({Stream.getBitcodeBytes().slice(
                               BCBegin, Stream.getCurrentByteNo() - BCBegin),
@@ -6438,7 +6438,7 @@ llvm::getBitcodeFileContents(MemoryBufferRef Buffer) {
       }
 
       if (Error Err = Stream.SkipBlock())
-        return Err;
+        return std::move(Err);
       continue;
     }
     case BitstreamEntry::Record:
@@ -6466,7 +6466,7 @@ BitcodeModule::getModuleImpl(LLVMContext &Context, bool MaterializeAll,
   std::string ProducerIdentification;
   if (IdentificationBit != -1ull) {
     if (Error JumpFailed = Stream.JumpToBit(IdentificationBit))
-      return JumpFailed;
+      return std::move(JumpFailed);
     Expected<std::string> ProducerIdentificationOrErr =
         readIdentificationBlock(Stream);
     if (!ProducerIdentificationOrErr)
@@ -6476,7 +6476,7 @@ BitcodeModule::getModuleImpl(LLVMContext &Context, bool MaterializeAll,
   }
 
   if (Error JumpFailed = Stream.JumpToBit(ModuleBit))
-    return JumpFailed;
+    return std::move(JumpFailed);
   auto *R = new BitcodeReader(std::move(Stream), Strtab, ProducerIdentification,
                               Context);
 
@@ -6487,18 +6487,18 @@ BitcodeModule::getModuleImpl(LLVMContext &Context, bool MaterializeAll,
   // Delay parsing Metadata if ShouldLazyLoadMetadata is true.
   if (Error Err =
           R->parseBitcodeInto(M.get(), ShouldLazyLoadMetadata, IsImporting))
-    return Err;
+    return std::move(Err);
 
   if (MaterializeAll) {
     // Read in the entire module, and destroy the BitcodeReader.
     if (Error Err = M->materializeAll())
-      return Err;
+      return std::move(Err);
   } else {
     // Resolve forward references from blockaddresses.
     if (Error Err = R->materializeForwardReferencedFunctions())
-      return Err;
+      return std::move(Err);
   }
-  return M;
+  return std::move(M);
 }
 
 Expected<std::unique_ptr<Module>>
@@ -6526,22 +6526,22 @@ Error BitcodeModule::readSummary(ModuleSummaryIndex &CombinedIndex,
 Expected<std::unique_ptr<ModuleSummaryIndex>> BitcodeModule::getSummary() {
   BitstreamCursor Stream(Buffer);
   if (Error JumpFailed = Stream.JumpToBit(ModuleBit))
-    return JumpFailed;
+    return std::move(JumpFailed);
 
   auto Index = std::make_unique<ModuleSummaryIndex>(/*HaveGVs=*/false);
   ModuleSummaryIndexBitcodeReader R(std::move(Stream), Strtab, *Index,
                                     ModuleIdentifier, 0);
 
   if (Error Err = R.parseModule())
-    return Err;
+    return std::move(Err);
 
-  return Index;
+  return std::move(Index);
 }
 
 static Expected<bool> getEnableSplitLTOUnitFlag(BitstreamCursor &Stream,
                                                 unsigned ID) {
   if (Error Err = Stream.EnterSubBlock(ID))
-    return Err;
+    return std::move(Err);
   SmallVector<uint64_t, 64> Record;
 
   while (true) {
@@ -6587,10 +6587,10 @@ static Expected<bool> getEnableSplitLTOUnitFlag(BitstreamCursor &Stream,
 Expected<BitcodeLTOInfo> BitcodeModule::getLTOInfo() {
   BitstreamCursor Stream(Buffer);
   if (Error JumpFailed = Stream.JumpToBit(ModuleBit))
-    return JumpFailed;
+    return std::move(JumpFailed);
 
   if (Error Err = Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
-    return Err;
+    return std::move(Err);
 
   while (true) {
     Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
@@ -6626,7 +6626,7 @@ Expected<BitcodeLTOInfo> BitcodeModule::getLTOInfo() {
 
       // Ignore other sub-blocks.
       if (Error Err = Stream.SkipBlock())
-        return Err;
+        return std::move(Err);
       continue;
 
     case BitstreamEntry::Record:

lib/Bitcode/Reader/MetadataLoader.cpp

@@ -711,7 +711,7 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
       case bitc::METADATA_STRINGS: {
         // Rewind and parse the strings.
         if (Error Err = IndexCursor.JumpToBit(CurrentPos))
-          return Err;
+          return std::move(Err);
         StringRef Blob;
         Record.clear();
         if (Expected<unsigned> MaybeRecord =
@@ -725,14 +725,14 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
           MDStringRef.push_back(Str);
         };
         if (auto Err = parseMetadataStrings(Record, Blob, IndexNextMDString))
-          return Err;
+          return std::move(Err);
         break;
       }
       case bitc::METADATA_INDEX_OFFSET: {
         // This is the offset to the index, when we see this we skip all the
         // records and load only an index to these.
         if (Error Err = IndexCursor.JumpToBit(CurrentPos))
-          return Err;
+          return std::move(Err);
         Record.clear();
         if (Expected<unsigned> MaybeRecord =
                 IndexCursor.readRecord(Entry.ID, Record))
@@ -744,7 +744,7 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
         auto Offset = Record[0] + (Record[1] << 32);
         auto BeginPos = IndexCursor.GetCurrentBitNo();
         if (Error Err = IndexCursor.JumpToBit(BeginPos + Offset))
-          return Err;
+          return std::move(Err);
         Expected<BitstreamEntry> MaybeEntry =
             IndexCursor.advanceSkippingSubblocks(
                 BitstreamCursor::AF_DontPopBlockAtEnd);
@@ -778,7 +778,7 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
       case bitc::METADATA_NAME: {
         // Named metadata need to be materialized now and aren't deferred.
         if (Error Err = IndexCursor.JumpToBit(CurrentPos))
-          return Err;
+          return std::move(Err);
         Record.clear();
 
         unsigned Code;
@@ -823,7 +823,7 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
         // FIXME: we need to do this early because we don't materialize global
         // value explicitly.
         if (Error Err = IndexCursor.JumpToBit(CurrentPos))
-          return Err;
+          return std::move(Err);
         Record.clear();
         if (Expected<unsigned> MaybeRecord =
                 IndexCursor.readRecord(Entry.ID, Record))
@@ -838,7 +838,7 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
         if (auto *GO = dyn_cast<GlobalObject>(ValueList[ValueID]))
           if (Error Err = parseGlobalObjectAttachment(
                   *GO, ArrayRef<uint64_t>(Record).slice(1)))
-            return Err;
+            return std::move(Err);
         break;
       }
       case bitc::METADATA_KIND:

lib/Bitstream/Reader/BitstreamReader.cpp

@@ -158,7 +158,7 @@ Expected<unsigned> BitstreamCursor::skipRecord(unsigned AbbrevID) {
         assert((unsigned)EltEnc.getEncodingData() <= MaxChunkSize);
         if (Error Err = JumpToBit(GetCurrentBitNo() +
                                   NumElts * EltEnc.getEncodingData()))
-          return Err;
+          return std::move(Err);
         break;
       case BitCodeAbbrevOp::VBR:
         assert((unsigned)EltEnc.getEncodingData() <= MaxChunkSize);
@@ -171,7 +171,7 @@ Expected<unsigned> BitstreamCursor::skipRecord(unsigned AbbrevID) {
         break;
       case BitCodeAbbrevOp::Char6:
         if (Error Err = JumpToBit(GetCurrentBitNo() + NumElts * 6))
-          return Err;
+          return std::move(Err);
         break;
       }
       continue;
@@ -197,7 +197,7 @@ Expected<unsigned> BitstreamCursor::skipRecord(unsigned AbbrevID) {
 
     // Skip over the blob.
     if (Error Err = JumpToBit(NewEnd))
-      return Err;
+      return std::move(Err);
   }
   return Code;
 }
@@ -326,7 +326,7 @@ Expected<unsigned> BitstreamCursor::readRecord(unsigned AbbrevID,
     // over tail padding first, in case jumping to NewEnd invalidates the Blob
     // pointer.
     if (Error Err = JumpToBit(NewEnd))
-      return Err;
+      return std::move(Err);
     const char *Ptr = (const char *)getPointerToBit(CurBitPos, NumElts);
 
     // If we can return a reference to the data, do so to avoid copying it.
@@ -401,7 +401,7 @@ Error BitstreamCursor::ReadAbbrevRecord() {
 Expected<Optional<BitstreamBlockInfo>>
 BitstreamCursor::ReadBlockInfoBlock(bool ReadBlockInfoNames) {
   if (llvm::Error Err = EnterSubBlock(bitc::BLOCKINFO_BLOCK_ID))
-    return Err;
+    return std::move(Err);
 
   BitstreamBlockInfo NewBlockInfo;
 
@@ -421,7 +421,7 @@ BitstreamCursor::ReadBlockInfoBlock(bool ReadBlockInfoNames) {
     case llvm::BitstreamEntry::Error:
       return None;
     case llvm::BitstreamEntry::EndBlock:
-      return NewBlockInfo;
+      return std::move(NewBlockInfo);
     case llvm::BitstreamEntry::Record:
       // The interesting case.
       break;
@@ -431,7 +431,7 @@ BitstreamCursor::ReadBlockInfoBlock(bool ReadBlockInfoNames) {
     if (Entry.ID == bitc::DEFINE_ABBREV) {
       if (!CurBlockInfo) return None;
       if (Error Err = ReadAbbrevRecord())
-        return Err;
+        return std::move(Err);
 
       // ReadAbbrevRecord installs the abbrev in CurAbbrevs.  Move it to the
       // appropriate BlockInfo.

lib/DebugInfo/CodeView/DebugStringTableSubsection.cpp

@@ -37,7 +37,7 @@ DebugStringTableSubsectionRef::getString(uint32_t Offset) const {
   Reader.setOffset(Offset);
   StringRef Result;
   if (auto EC = Reader.readCString(Result))
-    return EC;
+    return std::move(EC);
   return Result;
 }
 

lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp

@@ -481,7 +481,7 @@ DWARFDebugNames::NameIndex::extractAttributeEncodings(uint64_t *Offset) {
     if (!AttrEncOr)
       return AttrEncOr.takeError();
     if (isSentinel(*AttrEncOr))
-      return Result;
+      return std::move(Result);
 
     Result.emplace_back(*AttrEncOr);
   }
@@ -649,7 +649,7 @@ DWARFDebugNames::NameIndex::getEntry(uint64_t *Offset) const {
       return createStringError(errc::io_error,
                                "Error extracting index attribute values.");
   }
-  return E;
+  return std::move(E);
 }
 
 DWARFDebugNames::NameTableEntry

lib/DebugInfo/DWARF/DWARFDebugLine.cpp

@@ -522,7 +522,7 @@ Expected<const DWARFDebugLine::LineTable *> DWARFDebugLine::getOrParseLineTable(
   if (Pos.second) {
     if (Error Err =
             LT->parse(DebugLineData, &Offset, Ctx, U, RecoverableErrorCallback))
-      return Err;
+      return std::move(Err);
     return LT;
   }
   return LT;

lib/DebugInfo/DWARF/DWARFUnit.cpp

@@ -349,7 +349,7 @@ parseListTableHeader(DWARFDataExtractor &DA, uint64_t Offset,
   }
   ListTableType Table;
   if (Error E = Table.extractHeaderAndOffsets(DA, &Offset))
-    return E;
+    return std::move(E);
   return Table;
 }
 
@@ -621,7 +621,7 @@ DWARFUnit::findRnglistFromOffset(uint64_t Offset) {
   if (getVersion() <= 4) {
     DWARFDebugRangeList RangeList;
     if (Error E = extractRangeList(Offset, RangeList))
-      return E;
+      return std::move(E);
     return RangeList.getAbsoluteRanges(getBaseAddress());
   }
   if (RngListTable) {

lib/DebugInfo/DWARF/DWARFVerifier.cpp

@@ -34,11 +34,11 @@ DWARFVerifier::DieRangeInfo::insert(const DWARFAddressRange &R) {
 
   if (Pos != End) {
     if (Pos->intersects(R))
-      return Pos;
+      return std::move(Pos);
     if (Pos != Begin) {
       auto Iter = Pos - 1;
       if (Iter->intersects(R))
-        return Iter;
+        return std::move(Iter);
     }
   }
 

lib/DebugInfo/GSYM/FunctionInfo.cpp

@@ -90,7 +90,7 @@ llvm::Expected<FunctionInfo> FunctionInfo::decode(DataExtractor &Data,
     }
     Offset += InfoLength;
   }
-  return FI;
+  return std::move(FI);
 }
 
 llvm::Expected<uint64_t> FunctionInfo::encode(FileWriter &O) const {
@@ -114,7 +114,7 @@ llvm::Expected<uint64_t> FunctionInfo::encode(FileWriter &O) const {
     const auto StartOffset = O.tell();
     llvm::Error err = OptLineTable->encode(O, Range.Start);
     if (err)
-      return err;
+      return std::move(err);
     const auto Length = O.tell() - StartOffset;
     if (Length > UINT32_MAX)
         return createStringError(std::errc::invalid_argument,
@@ -132,7 +132,7 @@ llvm::Expected<uint64_t> FunctionInfo::encode(FileWriter &O) const {
     const auto StartOffset = O.tell();
     llvm::Error err = Inline->encode(O, Range.Start);
     if (err)
-      return err;
+      return std::move(err);
     const auto Length = O.tell() - StartOffset;
     if (Length > UINT32_MAX)
         return createStringError(std::errc::invalid_argument,
@@ -244,6 +244,6 @@ llvm::Expected<LookupResult> FunctionInfo::lookup(DataExtractor &Data,
   llvm::Error Err = InlineInfo::lookup(GR, *InlineInfoData, FuncAddr, Addr,
                                        LR.Locations);
   if (Err)
-    return Err;
+    return std::move(Err);
   return LR;
 }

lib/DebugInfo/GSYM/GsymReader.cpp

@@ -54,8 +54,8 @@ GsymReader::create(std::unique_ptr<MemoryBuffer> &MemBuffer) {
   GsymReader GR(std::move(MemBuffer));
   llvm::Error Err = GR.parse();
   if (Err)
-    return Err;
-  return GR;
+    return std::move(Err);
+  return std::move(GR);
 }
 
 llvm::Error

lib/DebugInfo/GSYM/Header.cpp

@@ -78,7 +78,7 @@ llvm::Expected<Header> Header::decode(DataExtractor &Data) {
   H.StrtabSize = Data.getU32(&Offset);
   Data.getU8(&Offset, H.UUID, GSYM_MAX_UUID_SIZE);
   if (llvm::Error Err = H.checkForError())
-    return Err;
+    return std::move(Err);
   return H;
 }
 

lib/DebugInfo/GSYM/LineTable.cpp

@@ -256,7 +256,7 @@ llvm::Expected<LineTable> LineTable::decode(DataExtractor &Data,
     return true; // Keep parsing by returning true.
   });
   if (Err)
-    return Err;
+    return std::move(Err);
   return LT;
 }
 // Parse the line table on the fly and find the row we are looking for.
@@ -278,7 +278,7 @@ Expected<LineEntry> LineTable::lookup(DataExtractor &Data, uint64_t BaseAddr, ui
     return true; // Keep parsing till we find the right row.
   });
   if (Err)
-    return Err;
+    return std::move(Err);
   if (Result.isValid())
     return Result;
   return createStringError(std::errc::invalid_argument,

lib/DebugInfo/MSF/MSFBuilder.cpp

@@ -183,7 +183,7 @@ Expected<uint32_t> MSFBuilder::addStream(uint32_t Size) {
   std::vector<uint32_t> NewBlocks;
   NewBlocks.resize(ReqBlocks);
   if (auto EC = allocateBlocks(ReqBlocks, NewBlocks))
-    return EC;
+    return std::move(EC);
   StreamData.push_back(std::make_pair(Size, NewBlocks));
   return StreamData.size() - 1;
 }
@@ -267,7 +267,7 @@ Expected<MSFLayout> MSFBuilder::generateLayout() {
     uint32_t NumExtraBlocks = NumDirectoryBlocks - DirectoryBlocks.size();
     ExtraBlocks.resize(NumExtraBlocks);
     if (auto EC = allocateBlocks(NumExtraBlocks, ExtraBlocks))
-      return EC;
+      return std::move(EC);
     DirectoryBlocks.insert(DirectoryBlocks.end(), ExtraBlocks.begin(),
                            ExtraBlocks.end());
   } else if (NumDirectoryBlocks < DirectoryBlocks.size()) {
@@ -346,14 +346,14 @@ Expected<FileBufferByteStream> MSFBuilder::commit(StringRef Path,
   uint64_t FileSize = Layout.SB->BlockSize * Layout.SB->NumBlocks;
   auto OutFileOrError = FileOutputBuffer::create(Path, FileSize);
   if (auto EC = OutFileOrError.takeError())
-    return EC;
+    return std::move(EC);
 
   FileBufferByteStream Buffer(std::move(*OutFileOrError),
                               llvm::support::little);
   BinaryStreamWriter Writer(Buffer);
 
   if (auto EC = Writer.writeObject(*Layout.SB))
-    return EC;
+    return std::move(EC);
 
   commitFpm(Buffer, Layout, Allocator);
 
@@ -361,21 +361,21 @@ Expected<FileBufferByteStream> MSFBuilder::commit(StringRef Path,
       msf::blockToOffset(Layout.SB->BlockMapAddr, Layout.SB->BlockSize);
   Writer.setOffset(BlockMapOffset);
   if (auto EC = Writer.writeArray(Layout.DirectoryBlocks))
-    return EC;
+    return std::move(EC);
 
   auto DirStream = WritableMappedBlockStream::createDirectoryStream(
       Layout, Buffer, Allocator);
   BinaryStreamWriter DW(*DirStream);
   if (auto EC = DW.writeInteger<uint32_t>(Layout.StreamSizes.size()))
-    return EC;
+    return std::move(EC);
 
   if (auto EC = DW.writeArray(Layout.StreamSizes))
-    return EC;
+    return std::move(EC);
 
   for (const auto &Blocks : Layout.StreamMap) {
     if (auto EC = DW.writeArray(Blocks))
-      return EC;
+      return std::move(EC);
   }
 
-  return Buffer;
+  return std::move(Buffer);
 }

lib/DebugInfo/PDB/Native/DbiModuleList.cpp

@@ -274,6 +274,6 @@ Expected<StringRef> DbiModuleList::getFileName(uint32_t Index) const {
   Names.setOffset(FileOffset);
   StringRef Name;
   if (auto EC = Names.readCString(Name))
-    return EC;
+    return std::move(EC);
   return Name;
 }

lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp

@@ -137,7 +137,7 @@ ModuleDebugStreamRef::findChecksumsSubsection() const {
       continue;
 
     if (auto EC = Result.initialize(SS.getRecordData()))
-      return EC;
+      return std::move(EC);
     return Result;
   }
   return Result;

lib/DebugInfo/PDB/Native/NativeEnumInjectedSources.cpp

@@ -24,7 +24,7 @@ Expected<std::string> readStreamData(BinaryStream &Stream, uint32_t Limit) {
   while (Offset < DataLength) {
     ArrayRef<uint8_t> Data;
     if (auto E = Stream.readLongestContiguousChunk(Offset, Data))
-      return E;
+      return std::move(E);
     Data = Data.take_front(DataLength - Offset);
     Offset += Data.size();
     Result += toStringRef(Data);

lib/DebugInfo/PDB/Native/PDBFile.cpp

@@ -108,7 +108,7 @@ Expected<ArrayRef<uint8_t>> PDBFile::getBlockData(uint32_t BlockIndex,
 
   ArrayRef<uint8_t> Result;
   if (auto EC = Buffer->readBytes(StreamBlockOffset, NumBytes, Result))
-    return EC;
+    return std::move(EC);
   return Result;
 }
 
@@ -267,7 +267,7 @@ Expected<GlobalsStream &> PDBFile::getPDBGlobalsStream() {
       return GlobalS.takeError();
     auto TempGlobals = std::make_unique<GlobalsStream>(std::move(*GlobalS));
     if (auto EC = TempGlobals->reload())
-      return EC;
+      return std::move(EC);
     Globals = std::move(TempGlobals);
   }
   return *Globals;
@@ -280,7 +280,7 @@ Expected<InfoStream &> PDBFile::getPDBInfoStream() {
       return InfoS.takeError();
     auto TempInfo = std::make_unique<InfoStream>(std::move(*InfoS));
     if (auto EC = TempInfo->reload())
-      return EC;
+      return std::move(EC);
     Info = std::move(TempInfo);
   }
   return *Info;
@@ -293,7 +293,7 @@ Expected<DbiStream &> PDBFile::getPDBDbiStream() {
       return DbiS.takeError();
     auto TempDbi = std::make_unique<DbiStream>(std::move(*DbiS));
     if (auto EC = TempDbi->reload(this))
-      return EC;
+      return std::move(EC);
     Dbi = std::move(TempDbi);
   }
   return *Dbi;
@@ -306,7 +306,7 @@ Expected<TpiStream &> PDBFile::getPDBTpiStream() {
       return TpiS.takeError();
     auto TempTpi = std::make_unique<TpiStream>(*this, std::move(*TpiS));
     if (auto EC = TempTpi->reload())
-      return EC;
+      return std::move(EC);
     Tpi = std::move(TempTpi);
   }
   return *Tpi;
@@ -322,7 +322,7 @@ Expected<TpiStream &> PDBFile::getPDBIpiStream() {
       return IpiS.takeError();
     auto TempIpi = std::make_unique<TpiStream>(*this, std::move(*IpiS));
     if (auto EC = TempIpi->reload())
-      return EC;
+      return std::move(EC);
     Ipi = std::move(TempIpi);
   }
   return *Ipi;
@@ -340,7 +340,7 @@ Expected<PublicsStream &> PDBFile::getPDBPublicsStream() {
       return PublicS.takeError();
     auto TempPublics = std::make_unique<PublicsStream>(std::move(*PublicS));
     if (auto EC = TempPublics->reload())
-      return EC;
+      return std::move(EC);
     Publics = std::move(TempPublics);
   }
   return *Publics;
@@ -359,7 +359,7 @@ Expected<SymbolStream &> PDBFile::getPDBSymbolStream() {
 
     auto TempSymbols = std::make_unique<SymbolStream>(std::move(*SymbolS));
     if (auto EC = TempSymbols->reload())
-      return EC;
+      return std::move(EC);
     Symbols = std::move(TempSymbols);
   }
   return *Symbols;
@@ -374,7 +374,7 @@ Expected<PDBStringTable &> PDBFile::getStringTable() {
     auto N = std::make_unique<PDBStringTable>();
     BinaryStreamReader Reader(**NS);
     if (auto EC = N->reload(Reader))
-      return EC;
+      return std::move(EC);
     assert(Reader.bytesRemaining() == 0);
     StringTableStream = std::move(*NS);
     Strings = std::move(N);
@@ -394,7 +394,7 @@ Expected<InjectedSourceStream &> PDBFile::getInjectedSourceStream() {
 
     auto IJ = std::make_unique<InjectedSourceStream>(std::move(*IJS));
     if (auto EC = IJ->reload(*Strings))
-      return EC;
+      return std::move(EC);
     InjectedSources = std::move(IJ);
   }
   return *InjectedSources;

lib/DebugInfo/PDB/Native/TpiHashing.cpp

@@ -44,7 +44,7 @@ static Expected<uint32_t> getHashForUdt(const CVType &Rec) {
   T Deserialized;
   if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
                                                Deserialized))
-    return E;
+    return std::move(E);
   return getHashForUdt(Deserialized, Rec.data());
 }
 
@@ -53,7 +53,7 @@ static Expected<TagRecordHash> getTagRecordHashForUdt(const CVType &Rec) {
   T Deserialized;
   if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
                                                Deserialized))
-    return E;
+    return std::move(E);
 
   ClassOptions Opts = Deserialized.getOptions();
 
@@ -79,7 +79,7 @@ static Expected<uint32_t> getSourceLineHash(const CVType &Rec) {
   T Deserialized;
   if (auto E = TypeDeserializer::deserializeAs(const_cast<CVType &>(Rec),
                                                Deserialized))
-    return E;
+    return std::move(E);
   char Buf[4];
   support::endian::write32le(Buf, Deserialized.getUDT().getIndex());
   return hashStringV1(StringRef(Buf, 4));

lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp

@@ -101,7 +101,7 @@ SymbolizableObjectFile::create(const object::ObjectFile *Obj,
   Uniquify(Fs);
   Uniquify(Os);
 
-  return res;
+  return std::move(res);
 }
 
 SymbolizableObjectFile::SymbolizableObjectFile(const ObjectFile *Obj,

lib/ExecutionEngine/JITLink/EHFrameSupport.cpp

@@ -547,7 +547,7 @@ EHFrameEdgeFixer::parseAugmentationString(BinaryStreamReader &RecordReader) {
   uint8_t *NextField = &AugInfo.Fields[0];
 
   if (auto Err = RecordReader.readInteger(NextChar))
-    return Err;
+    return std::move(Err);
 
   while (NextChar != 0) {
     switch (NextChar) {
@@ -556,7 +556,7 @@ EHFrameEdgeFixer::parseAugmentationString(BinaryStreamReader &RecordReader) {
       break;
     case 'e':
       if (auto Err = RecordReader.readInteger(NextChar))
-        return Err;
+        return std::move(Err);
       if (NextChar != 'h')
         return make_error<JITLinkError>("Unrecognized substring e" +
                                         Twine(NextChar) +
@@ -575,10 +575,10 @@ EHFrameEdgeFixer::parseAugmentationString(BinaryStreamReader &RecordReader) {
     }
 
     if (auto Err = RecordReader.readInteger(NextChar))
-      return Err;
+      return std::move(Err);
   }
 
-  return AugInfo;
+  return std::move(AugInfo);
 }
 
 Expected<JITTargetAddress>
@@ -589,11 +589,11 @@ EHFrameEdgeFixer::readAbsolutePointer(LinkGraph &G,
   JITTargetAddress Addr;
   if (G.getPointerSize() == 8) {
     if (auto Err = RecordReader.readInteger(Addr))
-      return Err;
+      return std::move(Err);
   } else if (G.getPointerSize() == 4) {
     uint32_t Addr32;
     if (auto Err = RecordReader.readInteger(Addr32))
-      return Err;
+      return std::move(Err);
     Addr = Addr32;
   } else
     llvm_unreachable("Pointer size is not 32-bit or 64-bit");

lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp

@@ -28,19 +28,19 @@ Expected<std::unique_ptr<LinkGraph>> MachOLinkGraphBuilder::buildGraph() {
     return make_error<JITLinkError>("Object is not a relocatable MachO");
 
   if (auto Err = createNormalizedSections())
-    return Err;
+    return std::move(Err);
 
   if (auto Err = createNormalizedSymbols())
-    return Err;
+    return std::move(Err);
 
   if (auto Err = graphifyRegularSymbols())
-    return Err;
+    return std::move(Err);
 
   if (auto Err = graphifySectionsWithCustomParsers())
-    return Err;
+    return std::move(Err);
 
   if (auto Err = addRelocations())
-    return Err;
+    return std::move(Err);
 
   return std::move(G);
 }

lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp

@@ -102,7 +102,7 @@ private:
 
 Optional<CompileOnDemandLayer::GlobalValueSet>
 CompileOnDemandLayer::compileRequested(GlobalValueSet Requested) {
-  return Requested;
+  return std::move(Requested);
 }
 
 Optional<CompileOnDemandLayer::GlobalValueSet>
@@ -294,7 +294,7 @@ void CompileOnDemandLayer::emitPartition(
             SymbolFlags[Mangle(GV->getName())] =
                 JITSymbolFlags::fromGlobalValue(*GV);
           if (auto Err = R.defineMaterializing(SymbolFlags))
-            return Err;
+            return std::move(Err);
         }
 
         expandPartition(*GVsToExtract);

lib/ExecutionEngine/Orc/CompileUtils.cpp

@@ -37,7 +37,7 @@ irManglingOptionsFromTargetOptions(const TargetOptions &Opts) {
 Expected<SimpleCompiler::CompileResult> SimpleCompiler::operator()(Module &M) {
   CompileResult CachedObject = tryToLoadFromObjectCache(M);
   if (CachedObject)
-    return CachedObject;
+    return std::move(CachedObject);
 
   SmallVector<char, 0> ObjBufferSV;
 
@@ -61,7 +61,7 @@ Expected<SimpleCompiler::CompileResult> SimpleCompiler::operator()(Module &M) {
     return Obj.takeError();
 
   notifyObjectCompiled(M, *ObjBuffer);
-  return ObjBuffer;
+  return std::move(ObjBuffer);
 }
 
 SimpleCompiler::CompileResult

lib/ExecutionEngine/Orc/Core.cpp

@@ -1455,7 +1455,7 @@ JITDylib::lookupFlags(LookupKind K, JITDylibLookupFlags JDLookupFlags,
 
       // Run this generator.
       if (auto Err = DG->tryToGenerate(K, *this, JDLookupFlags, LookupSet))
-        return Err;
+        return std::move(Err);
 
       // Re-try the search.
       lookupFlagsImpl(Result, K, JDLookupFlags, LookupSet);
@@ -1613,7 +1613,7 @@ JITDylib::legacyLookup(std::shared_ptr<AsynchronousSymbolQuery> Q,
   });
 
   if (Err)
-    return Err;
+    return std::move(Err);
 
   assert((MUs.empty() || !QueryComplete) &&
          "If action flags are set, there should be no work to do (so no MUs)");
@@ -1970,12 +1970,12 @@ Expected<SymbolMap> ExecutionSession::legacyLookup(
   auto ResultFuture = PromisedResult.get_future();
   auto Result = ResultFuture.get();
   if (ResolutionError)
-    return ResolutionError;
-  return Result;
+    return std::move(ResolutionError);
+  return std::move(Result);
 
 #else
   if (ResolutionError)
-    return ResolutionError;
+    return std::move(ResolutionError);
 
   return Result;
 #endif
@@ -2125,13 +2125,13 @@ ExecutionSession::lookup(const JITDylibSearchOrder &SearchOrder,
   auto Result = ResultFuture.get();
 
   if (ResolutionError)
-    return ResolutionError;
+    return std::move(ResolutionError);
 
-  return Result;
+  return std::move(Result);
 
 #else
   if (ResolutionError)
-    return ResolutionError;
+    return std::move(ResolutionError);
 
   return Result;
 #endif

lib/ExecutionEngine/Orc/DebugUtils.cpp

@@ -53,7 +53,7 @@ DumpObjects::operator()(std::unique_ptr<MemoryBuffer> Obj) {
     return errorCodeToError(EC);
   DumpStream.write(Obj->getBufferStart(), Obj->getBufferSize());
 
-  return Obj;
+  return std::move(Obj);
 }
 
 StringRef DumpObjects::getBufferIdentifier(MemoryBuffer &B) {

lib/ExecutionEngine/Orc/ExecutionUtils.cpp

@@ -267,9 +267,9 @@ StaticLibraryDefinitionGenerator::Create(
       new StaticLibraryDefinitionGenerator(L, std::move(ArchiveBuffer), Err));
 
   if (Err)
-    return Err;
+    return std::move(Err);
 
-  return ADG;
+  return std::move(ADG);
 }
 
 Error StaticLibraryDefinitionGenerator::tryToGenerate(

lib/ExecutionEngine/Orc/OrcCBindingsStack.h

@@ -305,7 +305,7 @@ public:
     Resolvers[K] = std::make_shared<CBindingsResolver>(*this, ExternalResolver,
                                                        ExternalResolverCtx);
     if (auto Err = Layer.addModule(K, std::move(M)))
-      return Err;
+      return std::move(Err);
 
     KeyLayers[K] = detail::createGenericLayer(Layer);
 
@@ -314,7 +314,7 @@ public:
     orc::LegacyCtorDtorRunner<OrcCBindingsStack> CtorRunner(
         AcknowledgeORCv1Deprecation, std::move(CtorNames), K);
     if (auto Err = CtorRunner.runViaLayer(*this))
-      return Err;
+      return std::move(Err);
 
     IRStaticDestructorRunners.emplace_back(AcknowledgeORCv1Deprecation,
                                            std::move(DtorNames), K);
@@ -365,7 +365,7 @@ public:
           *this, ExternalResolver, ExternalResolverCtx);
 
       if (auto Err = ObjectLayer.addObject(K, std::move(ObjBuffer)))
-        return Err;
+        return std::move(Err);
 
       KeyLayers[K] = detail::createGenericLayer(ObjectLayer);
 
@@ -399,7 +399,7 @@ public:
         return AddrOrErr.takeError();
     } else if (auto Err = Sym.takeError()) {
       // Lookup failure - report error.
-      return Err;
+      return std::move(Err);
     }
 
     // No symbol not found. Return 0.
@@ -417,7 +417,7 @@ public:
         return AddrOrErr.takeError();
     } else if (auto Err = Sym.takeError()) {
       // Lookup failure - report error.
-      return Err;
+      return std::move(Err);
     }
 
     // Symbol not found. Return 0.

lib/ExecutionEngine/RuntimeDyld/JITSymbol.cpp

@@ -119,7 +119,7 @@ LegacyJITSymbolResolver::getResponsibilitySet(const LookupSet &Symbols) {
       if (!Sym.getFlags().isStrong())
         Result.insert(Symbol);
     } else if (auto Err = Sym.takeError())
-      return Err;
+      return std::move(Err);
     else {
       // If there is no existing definition then the caller is responsible for
       // it.
@@ -127,5 +127,5 @@ LegacyJITSymbolResolver::getResponsibilitySet(const LookupSet &Symbols) {
     }
   }
 
-  return Result;
+  return std::move(Result);
 }

lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

@@ -194,7 +194,7 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
                                          CodeSize, CodeAlign,
                                          RODataSize, RODataAlign,
                                          RWDataSize, RWDataAlign))
-      return Err;
+      return std::move(Err);
     MemMgr.reserveAllocationSpace(CodeSize, CodeAlign, RODataSize, RODataAlign,
                                   RWDataSize, RWDataAlign);
   }
@@ -319,7 +319,7 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
       // Get symbol offset.
       uint64_t SectOffset;
       if (auto Err = getOffset(*I, *SI, SectOffset))
-        return Err;
+        return std::move(Err);
 
       bool IsCode = SI->isText();
       unsigned SectionID;
@@ -341,7 +341,7 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
   // Allocate common symbols
   if (auto Err = emitCommonSymbols(Obj, CommonSymbolsToAllocate, CommonSize,
                                    CommonAlign))
-    return Err;
+    return std::move(Err);
 
   // Parse and process relocations
   LLVM_DEBUG(dbgs() << "Parse relocations:\n");
@@ -432,7 +432,7 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
 
   // Give the subclasses a chance to tie-up any loose ends.
   if (auto Err = finalizeLoad(Obj, LocalSections))
-    return Err;
+    return std::move(Err);
 
 //   for (auto E : LocalSections)
 //     llvm::dbgs() << "Added: " << E.first.getRawDataRefImpl() << " -> " << E.second << "\n";

lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp

@@ -102,10 +102,10 @@ Expected<std::unique_ptr<DyldELFObject<ELFT>>>
 DyldELFObject<ELFT>::create(MemoryBufferRef Wrapper) {
   auto Obj = ELFObjectFile<ELFT>::create(Wrapper);
   if (auto E = Obj.takeError())
-    return E;
+    return std::move(E);
   std::unique_ptr<DyldELFObject<ELFT>> Ret(
       new DyldELFObject<ELFT>(std::move(*Obj)));
-  return Ret;
+  return std::move(Ret);
 }
 
 template <class ELFT>
@@ -153,7 +153,7 @@ createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject,
   Expected<std::unique_ptr<DyldELFObject<ELFT>>> ObjOrErr =
       DyldELFObject<ELFT>::create(Buffer);
   if (Error E = ObjOrErr.takeError())
-    return E;
+    return std::move(E);
 
   std::unique_ptr<DyldELFObject<ELFT>> Obj = std::move(*ObjOrErr);
 
@@ -180,7 +180,7 @@ createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject,
     ++SI;
   }
 
-  return Obj;
+  return std::move(Obj);
 }
 
 static OwningBinary<ObjectFile>
@@ -1460,7 +1460,7 @@ RuntimeDyldELF::processRelocationRef(
           // so the final symbol value is calculated based on the relocation
           // values in the .opd section.
           if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value))
-            return Err;
+            return std::move(Err);
         } else {
           // In the ELFv2 ABI, a function symbol may provide a local entry
           // point, which must be used for direct calls.
@@ -1574,7 +1574,7 @@ RuntimeDyldELF::processRelocationRef(
 
       RelocationValueRef TOCValue;
       if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue))
-        return Err;
+        return std::move(Err);
       if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
         llvm_unreachable("Unsupported TOC relocation.");
       Value.Addend -= TOCValue.Addend;
@@ -1587,10 +1587,10 @@ RuntimeDyldELF::processRelocationRef(
       if (RelType == ELF::R_PPC64_TOC) {
         RelType = ELF::R_PPC64_ADDR64;
         if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
-          return Err;
+          return std::move(Err);
       } else if (TargetName == ".TOC.") {
         if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
-          return Err;
+          return std::move(Err);
         Value.Addend += Addend;
       }
 

lib/IR/LLVMRemarkStreamer.cpp

@@ -133,7 +133,7 @@ Expected<std::unique_ptr<ToolOutputFile>> llvm::setupLLVMOptimizationRemarks(
     if (Error E = Context.getMainRemarkStreamer()->setFilter(RemarksPasses))
       return make_error<LLVMRemarkSetupPatternError>(std::move(E));
 
-  return RemarksFile;
+  return std::move(RemarksFile);
 }
 
 Error llvm::setupLLVMOptimizationRemarks(LLVMContext &Context, raw_ostream &OS,

lib/LTO/LTO.cpp

@@ -456,7 +456,7 @@ Expected<std::unique_ptr<InputFile>> InputFile::create(MemoryBufferRef Object) {
 
   File->Mods = FOrErr->Mods;
   File->Strtab = std::move(FOrErr->Strtab);
-  return File;
+  return std::move(File);
 }
 
 StringRef InputFile::getName() const {
@@ -676,7 +676,7 @@ LTO::addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
   Mod.M = std::move(*MOrErr);
 
   if (Error Err = M.materializeMetadata())
-    return Err;
+    return std::move(Err);
   UpgradeDebugInfo(M);
 
   ModuleSymbolTable SymTab;
@@ -776,7 +776,7 @@ LTO::addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms,
     for (GlobalValue &GV : M.global_values())
       handleNonPrevailingComdat(GV, NonPrevailingComdats);
   assert(MsymI == MsymE);
-  return Mod;
+  return std::move(Mod);
 }
 
 Error LTO::linkRegularLTO(RegularLTOState::AddedModule Mod,
@@ -1429,7 +1429,7 @@ Expected<std::unique_ptr<ToolOutputFile>> lto::setupLLVMOptimizationRemarks(
   auto ResultOrErr = llvm::setupLLVMOptimizationRemarks(
       Context, Filename, RemarksPasses, RemarksFormat, RemarksWithHotness);
   if (Error E = ResultOrErr.takeError())
-    return E;
+    return std::move(E);
 
   if (*ResultOrErr)
     (*ResultOrErr)->keep();
@@ -1451,5 +1451,5 @@ lto::setupStatsFile(StringRef StatsFilename) {
     return errorCodeToError(EC);
 
   StatsFile->keep();
-  return StatsFile;
+  return std::move(StatsFile);
 }

lib/LTO/LTOModule.cpp

@@ -232,7 +232,7 @@ LTOModule::makeLTOModule(MemoryBufferRef Buffer, const TargetOptions &options,
   Ret->parseSymbols();
   Ret->parseMetadata();
 
-  return Ret;
+  return std::move(Ret);
 }
 
 /// Create a MemoryBuffer from a memory range with an optional name.

lib/MCA/InstrBuilder.cpp

@@ -564,7 +564,7 @@ InstrBuilder::createInstrDescImpl(const MCInst &MCI) {
   computeMaxLatency(*ID, MCDesc, SCDesc, STI);
 
   if (Error Err = verifyOperands(MCDesc, MCI))
-    return Err;
+    return std::move(Err);
 
   populateWrites(*ID, MCI, SchedClassID);
   populateReads(*ID, MCI, SchedClassID);
@@ -574,7 +574,7 @@ InstrBuilder::createInstrDescImpl(const MCInst &MCI) {
 
   // Sanity check on the instruction descriptor.
   if (Error Err = verifyInstrDesc(*ID, MCI))
-    return Err;
+    return std::move(Err);
 
   // Now add the new descriptor.
   bool IsVariadic = MCDesc.isVariadic();
@@ -666,7 +666,7 @@ InstrBuilder::createInstruction(const MCInst &MCI) {
 
   // Early exit if there are no writes.
   if (D.Writes.empty())
-    return NewIS;
+    return std::move(NewIS);
 
   // Track register writes that implicitly clear the upper portion of the
   // underlying super-registers using an APInt.
@@ -695,7 +695,7 @@ InstrBuilder::createInstruction(const MCInst &MCI) {
     ++WriteIndex;
   }
 
-  return NewIS;
+  return std::move(NewIS);
 }
 } // namespace mca
 } // namespace llvm

lib/MCA/Pipeline.cpp

@@ -40,7 +40,7 @@ Expected<unsigned> Pipeline::run() {
   do {
     notifyCycleBegin();
     if (Error Err = runCycle())
-      return Err;
+      return std::move(Err);
     notifyCycleEnd();
     ++Cycles;
   } while (hasWorkToProcess());

lib/Object/Archive.cpp

@@ -481,7 +481,7 @@ Expected<Archive::Child> Archive::Child::getNext() const {
   Error Err = Error::success();
   Child Ret(Parent, NextLoc, &Err);
   if (Err)
-    return Err;
+    return std::move(Err);
   return Ret;
 }
 
@@ -531,8 +531,8 @@ Expected<std::unique_ptr<Archive>> Archive::create(MemoryBufferRef Source) {
   Error Err = Error::success();
   std::unique_ptr<Archive> Ret(new Archive(Source, Err));
   if (Err)
-    return Err;
-  return Ret;
+    return std::move(Err);
+  return std::move(Ret);
 }
 
 void Archive::setFirstRegular(const Child &C) {
@@ -852,7 +852,7 @@ Expected<Archive::Child> Archive::Symbol::getMember() const {
   Error Err = Error::success();
   Child C(Parent, Loc, &Err);
   if (Err)
-    return Err;
+    return std::move(Err);
   return C;
 }
 

lib/Object/ArchiveWriter.cpp

@@ -70,7 +70,7 @@ NewArchiveMember::getOldMember(const object::Archive::Child &OldMember,
       return AccessModeOrErr.takeError();
     M.Perms = AccessModeOrErr.get();
   }
-  return M;
+  return std::move(M);
 }
 
 Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
@@ -109,7 +109,7 @@ Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
     M.GID = Status.getGroup();
     M.Perms = Status.permissions();
   }
-  return M;
+  return std::move(M);
 }
 
 template <typename T>
@@ -379,7 +379,7 @@ getSymbols(MemoryBufferRef Buf, raw_ostream &SymNames, bool &HasObject) {
       continue;
     Ret.push_back(SymNames.tell());
     if (Error E = S.printName(SymNames))
-      return E;
+      return std::move(E);
     SymNames << '\0';
   }
   return Ret;
@@ -492,7 +492,7 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
     Expected<std::vector<unsigned>> Symbols =
         getSymbols(Buf, SymNames, HasObject);
     if (auto E = Symbols.takeError())
-      return E;
+      return std::move(E);
 
     Pos += Header.size() + Data.size() + Padding.size();
     Ret.push_back({std::move(*Symbols), std::move(Header), Data, Padding});

lib/Object/COFFModuleDefinition.cpp

@@ -151,7 +151,7 @@ public:
   Expected<COFFModuleDefinition> parse() {
     do {
       if (Error Err = parseOne())
-        return Err;
+        return std::move(Err);
     } while (Tok.K != Eof);
     return Info;
   }

lib/Object/COFFObjectFile.cpp

@@ -297,7 +297,7 @@ COFFObjectFile::getSectionContents(DataRefImpl Ref) const {
   const coff_section *Sec = toSec(Ref);
   ArrayRef<uint8_t> Res;
   if (Error E = getSectionContents(Sec, Res))
-    return E;
+    return std::move(E);
   return Res;
 }
 
@@ -1625,7 +1625,7 @@ ObjectFile::createCOFFObjectFile(MemoryBufferRef Object) {
   std::unique_ptr<COFFObjectFile> Ret(new COFFObjectFile(Object, EC));
   if (EC)
     return errorCodeToError(EC);
-  return Ret;
+  return std::move(Ret);
 }
 
 bool BaseRelocRef::operator==(const BaseRelocRef &Other) const {
@@ -1666,7 +1666,7 @@ std::error_code BaseRelocRef::getRVA(uint32_t &Result) const {
   do {                                                                         \
     Error E = (Expr);                                                          \
     if (E)                                                                     \
-      return E;                                                                \
+      return std::move(E);                                                     \
   } while (0)
 
 Expected<ArrayRef<UTF16>>
@@ -1832,7 +1832,7 @@ ResourceSectionRef::getContents(const coff_resource_data_entry &Entry) {
     uint64_t Offset = Entry.DataRVA + Sym->getValue();
     ArrayRef<uint8_t> Contents;
     if (Error E = Obj->getSectionContents(Section, Contents))
-      return E;
+      return std::move(E);
     if (Offset + Entry.DataSize > Contents.size())
       return createStringError(object_error::parse_failed,
                                "data outside of section");

lib/Object/Decompressor.cpp

@@ -26,7 +26,7 @@ Expected<Decompressor> Decompressor::create(StringRef Name, StringRef Data,
   Error Err = isGnuStyle(Name) ? D.consumeCompressedGnuHeader()
                                : D.consumeCompressedZLibHeader(Is64Bit, IsLE);
   if (Err)
-    return Err;
+    return std::move(Err);
   return D;
 }
 

lib/Object/ELFObjectFile.cpp

@@ -62,7 +62,7 @@ static Expected<std::unique_ptr<ELFObjectFile<ELFT>>>
 createPtr(MemoryBufferRef Object) {
   auto Ret = ELFObjectFile<ELFT>::create(Object);
   if (Error E = Ret.takeError())
-    return E;
+    return std::move(E);
   return std::make_unique<ELFObjectFile<ELFT>>(std::move(*Ret));
 }
 

lib/Object/IRObjectFile.cpp

@@ -151,5 +151,5 @@ Expected<IRSymtabFile> object::readIRSymtab(MemoryBufferRef MBRef) {
   F.Symtab = std::move(FCOrErr->Symtab);
   F.Strtab = std::move(FCOrErr->Strtab);
   F.TheReader = std::move(FCOrErr->TheReader);
-  return F;
+  return std::move(F);
 }

lib/Object/IRSymtab.cpp

@@ -363,7 +363,7 @@ static Expected<FileContents> upgrade(ArrayRef<BitcodeModule> BMs) {
   StringTableBuilder StrtabBuilder(StringTableBuilder::RAW);
   BumpPtrAllocator Alloc;
   if (Error E = build(Mods, FC.Symtab, StrtabBuilder, Alloc))
-    return E;
+    return std::move(E);
 
   StrtabBuilder.finalizeInOrder();
   FC.Strtab.resize(StrtabBuilder.getSize());
@@ -371,7 +371,7 @@ static Expected<FileContents> upgrade(ArrayRef<BitcodeModule> BMs) {
 
   FC.TheReader = {{FC.Symtab.data(), FC.Symtab.size()},
                   {FC.Strtab.data(), FC.Strtab.size()}};
-  return FC;
+  return std::move(FC);
 }
 
 Expected<FileContents> irsymtab::readBitcode(const BitcodeFileContents &BFC) {
@@ -405,5 +405,5 @@ Expected<FileContents> irsymtab::readBitcode(const BitcodeFileContents &BFC) {
   if (FC.TheReader.getNumModules() != BFC.Mods.size())
     return upgrade(std::move(BFC.Mods));
 
-  return FC;
+  return std::move(FC);
 }

lib/Object/MachOObjectFile.cpp

@@ -1251,8 +1251,8 @@ MachOObjectFile::create(MemoryBufferRef Object, bool IsLittleEndian,
                           Is64Bits, Err, UniversalCputype,
                           UniversalIndex));
   if (Err)
-    return Err;
-  return Obj;
+    return std::move(Err);
+  return std::move(Obj);
 }
 
 MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,

lib/Object/MachOUniversal.cpp

@@ -105,8 +105,8 @@ MachOUniversalBinary::create(MemoryBufferRef Source) {
   std::unique_ptr<MachOUniversalBinary> Ret(
       new MachOUniversalBinary(Source, Err));
   if (Err)
-    return Err;
-  return Ret;
+    return std::move(Err);
+  return std::move(Ret);
 }
 
 MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)

lib/Object/ObjectFile.cpp

@@ -182,7 +182,7 @@ ObjectFile::createObjectFile(StringRef ObjectPath) {
   Expected<std::unique_ptr<ObjectFile>> ObjOrErr =
       createObjectFile(Buffer->getMemBufferRef());
   if (Error Err = ObjOrErr.takeError())
-    return Err;
+    return std::move(Err);
   std::unique_ptr<ObjectFile> Obj = std::move(ObjOrErr.get());
 
   return OwningBinary<ObjectFile>(std::move(Obj), std::move(Buffer));

lib/Object/SymbolicFile.cpp

@@ -82,13 +82,13 @@ SymbolicFile::createSymbolicFile(MemoryBufferRef Object, file_magic Type,
     Expected<std::unique_ptr<ObjectFile>> Obj =
         ObjectFile::createObjectFile(Object, Type);
     if (!Obj || !Context)
-      return Obj;
+      return std::move(Obj);
 
     Expected<MemoryBufferRef> BCData =
         IRObjectFile::findBitcodeInObject(*Obj->get());
     if (!BCData) {
       consumeError(BCData.takeError());
-      return Obj;
+      return std::move(Obj);
     }
 
     return IRObjectFile::create(

lib/Object/TapiUniversal.cpp

@@ -49,6 +49,6 @@ TapiUniversal::create(MemoryBufferRef Source) {
   Error Err = Error::success();
   std::unique_ptr<TapiUniversal> Ret(new TapiUniversal(Source, Err));
   if (Err)
-    return Err;
-  return Ret;
+    return std::move(Err);
+  return std::move(Ret);
 }

lib/Object/WasmObjectFile.cpp

@@ -58,9 +58,9 @@ ObjectFile::createWasmObjectFile(MemoryBufferRef Buffer) {
   Error Err = Error::success();
   auto ObjectFile = std::make_unique<WasmObjectFile>(Buffer, Err);
   if (Err)
-    return Err;
+    return std::move(Err);
 
-  return ObjectFile;
+  return std::move(ObjectFile);
 }
 
 #define VARINT7_MAX ((1 << 7) - 1)

lib/Object/WindowsResource.cpp

@@ -63,7 +63,7 @@ WindowsResource::createWindowsResource(MemoryBufferRef Source) {
         Source.getBufferIdentifier() + ": too small to be a resource file",
         object_error::invalid_file_type);
   std::unique_ptr<WindowsResource> Ret(new WindowsResource(Source));
-  return Ret;
+  return std::move(Ret);
 }
 
 Expected<ResourceEntryRef> WindowsResource::getHeadEntry() {
@@ -81,7 +81,7 @@ Expected<ResourceEntryRef>
 ResourceEntryRef::create(BinaryStreamRef BSR, const WindowsResource *Owner) {
   auto Ref = ResourceEntryRef(BSR, Owner);
   if (auto E = Ref.loadNext())
-    return E;
+    return std::move(E);
   return Ref;
 }
 
@@ -1005,7 +1005,7 @@ writeWindowsResourceCOFF(COFF::MachineTypes MachineType,
   Error E = Error::success();
   WindowsResourceCOFFWriter Writer(MachineType, Parser, E);
   if (E)
-    return E;
+    return std::move(E);
   return Writer.write(TimeDateStamp);
 }
 

lib/Object/XCOFFObjectFile.cpp

@@ -604,7 +604,7 @@ XCOFFObjectFile::relocations(const XCOFFSectionHeader32 &Sec) const {
                                       Sec.FileOffsetToRelocationInfo);
   auto NumRelocEntriesOrErr = getLogicalNumberOfRelocationEntries(Sec);
   if (Error E = NumRelocEntriesOrErr.takeError())
-    return E;
+    return std::move(E);
 
   uint32_t NumRelocEntries = NumRelocEntriesOrErr.get();
 
@@ -613,7 +613,7 @@ XCOFFObjectFile::relocations(const XCOFFSectionHeader32 &Sec) const {
       getObject<XCOFFRelocation32>(Data, reinterpret_cast<void *>(RelocAddr),
                                    NumRelocEntries * sizeof(XCOFFRelocation32));
   if (Error E = RelocationOrErr.takeError())
-    return E;
+    return std::move(E);
 
   const XCOFFRelocation32 *StartReloc = RelocationOrErr.get();
 
@@ -639,7 +639,7 @@ XCOFFObjectFile::parseStringTable(const XCOFFObjectFile *Obj, uint64_t Offset) {
   auto StringTableOrErr =
       getObject<char>(Obj->Data, Obj->base() + Offset, Size);
   if (Error E = StringTableOrErr.takeError())
-    return E;
+    return std::move(E);
 
   const char *StringTablePtr = StringTableOrErr.get();
   if (StringTablePtr[Size - 1] != '\0')
@@ -662,7 +662,7 @@ XCOFFObjectFile::create(unsigned Type, MemoryBufferRef MBR) {
   auto FileHeaderOrErr =
       getObject<void>(Data, Base + CurOffset, Obj->getFileHeaderSize());
   if (Error E = FileHeaderOrErr.takeError())
-    return E;
+    return std::move(E);
   Obj->FileHeader = FileHeaderOrErr.get();
 
   CurOffset += Obj->getFileHeaderSize();
@@ -676,17 +676,17 @@ XCOFFObjectFile::create(unsigned Type, MemoryBufferRef MBR) {
                                            Obj->getNumberOfSections() *
                                                Obj->getSectionHeaderSize());
     if (Error E = SecHeadersOrErr.takeError())
-      return E;
+      return std::move(E);
     Obj->SectionHeaderTable = SecHeadersOrErr.get();
   }
 
   // 64-bit object supports only file header and section headers for now.
   if (Obj->is64Bit())
-    return Obj;
+    return std::move(Obj);
 
   // If there is no symbol table we are done parsing the memory buffer.
   if (Obj->getLogicalNumberOfSymbolTableEntries32() == 0)
-    return Obj;
+    return std::move(Obj);
 
   // Parse symbol table.
   CurOffset = Obj->fileHeader32()->SymbolTableOffset;
@@ -695,7 +695,7 @@ XCOFFObjectFile::create(unsigned Type, MemoryBufferRef MBR) {
   auto SymTableOrErr =
       getObject<XCOFFSymbolEntry>(Data, Base + CurOffset, SymbolTableSize);
   if (Error E = SymTableOrErr.takeError())
-    return E;
+    return std::move(E);
   Obj->SymbolTblPtr = SymTableOrErr.get();
   CurOffset += SymbolTableSize;
 
@@ -703,10 +703,10 @@ XCOFFObjectFile::create(unsigned Type, MemoryBufferRef MBR) {
   Expected<XCOFFStringTable> StringTableOrErr =
       parseStringTable(Obj.get(), CurOffset);
   if (Error E = StringTableOrErr.takeError())
-    return E;
+    return std::move(E);
   Obj->StringTable = StringTableOrErr.get();
 
-  return Obj;
+  return std::move(Obj);
 }
 
 Expected<std::unique_ptr<ObjectFile>>

lib/ObjectYAML/CodeViewYAMLDebugSections.cpp

@@ -694,11 +694,11 @@ YAMLStringTableSubsection::fromCodeViewSubsection(
   StringRef S;
   // First item is a single null string, skip it.
   if (auto EC = Reader.readCString(S))
-    return EC;
+    return std::move(EC);
   assert(S.empty());
   while (Reader.bytesRemaining() > 0) {
     if (auto EC = Reader.readCString(S))
-      return EC;
+      return std::move(EC);
     Result->Strings.push_back(S);
   }
   return Result;
@@ -749,7 +749,7 @@ llvm::CodeViewYAML::toCodeViewSubsectionList(
     const codeview::StringsAndChecksums &SC) {
   std::vector<std::shared_ptr<DebugSubsection>> Result;
   if (Subsections.empty())
-    return Result;
+    return std::move(Result);
 
   for (const auto &SS : Subsections) {
     std::shared_ptr<DebugSubsection> CVS;
@@ -757,7 +757,7 @@ llvm::CodeViewYAML::toCodeViewSubsectionList(
     assert(CVS != nullptr);
     Result.push_back(std::move(CVS));
   }
-  return Result;
+  return std::move(Result);
 }
 
 namespace {
@@ -892,7 +892,7 @@ YAMLDebugSubsection::fromCodeViewSubection(const StringsAndChecksumsRef &SC,
                                            const DebugSubsectionRecord &SS) {
   SubsectionConversionVisitor V;
   if (auto EC = visitDebugSubsection(SS, V, SC))
-    return EC;
+    return std::move(EC);
 
   return V.Subsection;
 }

lib/ObjectYAML/CodeViewYAMLSymbols.cpp

@@ -585,7 +585,7 @@ fromCodeViewSymbolImpl(CVSymbol Symbol) {
 
   auto Impl = std::make_shared<SymbolType>(Symbol.kind());
   if (auto EC = Impl->fromCodeViewSymbol(Symbol))
-    return EC;
+    return std::move(EC);
   Result.Symbol = Impl;
   return Result;
 }

lib/ObjectYAML/CodeViewYAMLTypes.cpp

@@ -671,7 +671,7 @@ static inline Expected<LeafRecord> fromCodeViewRecordImpl(CVType Type) {
 
   auto Impl = std::make_shared<LeafRecordImpl<T>>(Type.kind());
   if (auto EC = Impl->fromCodeViewRecord(Type))
-    return EC;
+    return std::move(EC);
   Result.Leaf = Impl;
   return Result;
 }

lib/ObjectYAML/DWARFEmitter.cpp

@@ -377,5 +377,5 @@ DWARFYAML::EmitDebugSections(StringRef YAMLString, bool ApplyFixups,
                        DebugSections);
   EmitDebugSectionImpl(DI, &DWARFYAML::EmitDebugAranges, "debug_aranges",
                        DebugSections);
-  return DebugSections;
+  return std::move(DebugSections);
 }

lib/ProfileData/Coverage/CoverageMapping.cpp

@@ -284,14 +284,14 @@ Expected<std::unique_ptr<CoverageMapping>> CoverageMapping::load(
   for (const auto &CoverageReader : CoverageReaders) {
     for (auto RecordOrErr : *CoverageReader) {
       if (Error E = RecordOrErr.takeError())
-        return E;
+        return std::move(E);
       const auto &Record = *RecordOrErr;
       if (Error E = Coverage->loadFunctionRecord(Record, ProfileReader))
-        return E;
+        return std::move(E);
     }
   }
 
-  return Coverage;
+  return std::move(Coverage);
 }
 
 // If E is a no_data_found error, returns success. Otherwise returns E.
@@ -309,7 +309,7 @@ CoverageMapping::load(ArrayRef<StringRef> ObjectFilenames,
                       StringRef ProfileFilename, ArrayRef<StringRef> Arches) {
   auto ProfileReaderOrErr = IndexedInstrProfReader::create(ProfileFilename);
   if (Error E = ProfileReaderOrErr.takeError())
-    return E;
+    return std::move(E);
   auto ProfileReader = std::move(ProfileReaderOrErr.get());
 
   SmallVector<std::unique_ptr<CoverageMappingReader>, 4> Readers;
@@ -326,7 +326,7 @@ CoverageMapping::load(ArrayRef<StringRef> ObjectFilenames,
     if (Error E = CoverageReadersOrErr.takeError()) {
       E = handleMaybeNoDataFoundError(std::move(E));
       if (E)
-        return E;
+        return std::move(E);
       // E == success (originally a no_data_found error).
       continue;
     }

lib/ProfileData/Coverage/CoverageMappingReader.cpp

@@ -321,28 +321,28 @@ Expected<bool> RawCoverageMappingDummyChecker::isDummy() {
   // A dummy coverage mapping data consists of just one region with zero count.
   uint64_t NumFileMappings;
   if (Error Err = readSize(NumFileMappings))
-    return Err;
+    return std::move(Err);
   if (NumFileMappings != 1)
     return false;
   // We don't expect any specific value for the filename index, just skip it.
   uint64_t FilenameIndex;
   if (Error Err =
           readIntMax(FilenameIndex, std::numeric_limits<unsigned>::max()))
-    return Err;
+    return std::move(Err);
   uint64_t NumExpressions;
   if (Error Err = readSize(NumExpressions))
-    return Err;
+    return std::move(Err);
   if (NumExpressions != 0)
     return false;
   uint64_t NumRegions;
   if (Error Err = readSize(NumRegions))
-    return Err;
+    return std::move(Err);
   if (NumRegions != 1)
     return false;
   uint64_t EncodedCounterAndRegion;
   if (Error Err = readIntMax(EncodedCounterAndRegion,
                              std::numeric_limits<unsigned>::max()))
-    return Err;
+    return std::move(Err);
   unsigned Tag = EncodedCounterAndRegion & Counter::EncodingTagMask;
   return Tag == Counter::Zero;
 }
@@ -494,7 +494,7 @@ public:
     size_t FilenamesBegin = Filenames.size();
     RawCoverageFilenamesReader Reader(StringRef(Buf, FilenamesSize), Filenames);
     if (auto Err = Reader.read())
-      return Err;
+      return std::move(Err);
     Buf += FilenamesSize;
 
     // We'll read the coverage mapping records in the loop below.
@@ -521,7 +521,7 @@ public:
 
       if (Error Err =
               insertFunctionRecordIfNeeded(CFR, Mapping, FilenamesBegin))
-        return Err;
+        return std::move(Err);
       CFR++;
     }
     return Buf;
@@ -545,7 +545,7 @@ Expected<std::unique_ptr<CovMapFuncRecordReader>> CovMapFuncRecordReader::get(
   case CovMapVersion::Version3:
     // Decompress the name data.
     if (Error E = P.create(P.getNameData()))
-      return E;
+      return std::move(E);
     if (Version == CovMapVersion::Version2)
       return std::make_unique<VersionedCovMapFuncRecordReader<
           CovMapVersion::Version2, IntPtrT, Endian>>(P, R, F);
@@ -597,26 +597,26 @@ BinaryCoverageReader::createCoverageReaderFromBuffer(
             readCoverageMappingData<uint32_t, support::endianness::little>(
                 Reader->ProfileNames, Coverage, Reader->MappingRecords,
                 Reader->Filenames))
-      return E;
+      return std::move(E);
   } else if (BytesInAddress == 4 && Endian == support::endianness::big) {
     if (Error E = readCoverageMappingData<uint32_t, support::endianness::big>(
             Reader->ProfileNames, Coverage, Reader->MappingRecords,
             Reader->Filenames))
-      return E;
+      return std::move(E);
   } else if (BytesInAddress == 8 && Endian == support::endianness::little) {
     if (Error E =
             readCoverageMappingData<uint64_t, support::endianness::little>(
                 Reader->ProfileNames, Coverage, Reader->MappingRecords,
                 Reader->Filenames))
-      return E;
+      return std::move(E);
   } else if (BytesInAddress == 8 && Endian == support::endianness::big) {
     if (Error E = readCoverageMappingData<uint64_t, support::endianness::big>(
             Reader->ProfileNames, Coverage, Reader->MappingRecords,
             Reader->Filenames))
-      return E;
+      return std::move(E);
   } else
     return make_error<CoverageMapError>(coveragemap_error::malformed);
-  return Reader;
+  return std::move(Reader);
 }
 
 static Expected<std::unique_ptr<BinaryCoverageReader>>
@@ -643,7 +643,7 @@ loadTestingFormat(StringRef Data) {
     return make_error<CoverageMapError>(coveragemap_error::malformed);
   InstrProfSymtab ProfileNames;
   if (Error E = ProfileNames.create(Data.substr(0, ProfileNamesSize), Address))
-    return E;
+    return std::move(E);
   StringRef CoverageMapping = Data.substr(ProfileNamesSize);
   // Skip the padding bytes because coverage map data has an alignment of 8.
   if (CoverageMapping.empty())
@@ -708,12 +708,12 @@ loadBinaryFormat(std::unique_ptr<Binary> Bin, StringRef Arch) {
       lookupSection(*OF, getInstrProfSectionName(IPSK_name, ObjFormat,
                                                  /*AddSegmentInfo=*/false));
   if (auto E = NamesSection.takeError())
-    return E;
+    return std::move(E);
   auto CoverageSection =
       lookupSection(*OF, getInstrProfSectionName(IPSK_covmap, ObjFormat,
                                                  /*AddSegmentInfo=*/false));
   if (auto E = CoverageSection.takeError())
-    return E;
+    return std::move(E);
 
   // Get the contents of the given sections.
   auto CoverageMappingOrErr = CoverageSection->getContents();
@@ -722,7 +722,7 @@ loadBinaryFormat(std::unique_ptr<Binary> Bin, StringRef Arch) {
 
   InstrProfSymtab ProfileNames;
   if (Error E = ProfileNames.create(*NamesSection))
-    return E;
+    return std::move(E);
 
   return BinaryCoverageReader::createCoverageReaderFromBuffer(
       CoverageMappingOrErr.get(), std::move(ProfileNames), BytesInAddress,
@@ -741,7 +741,7 @@ BinaryCoverageReader::create(
     if (!ReaderOrErr)
       return ReaderOrErr.takeError();
     Readers.push_back(std::move(ReaderOrErr.get()));
-    return Readers;
+    return std::move(Readers);
   }
 
   auto BinOrErr = createBinary(ObjectBuffer);
@@ -786,7 +786,7 @@ BinaryCoverageReader::create(
         Readers.push_back(std::move(Reader));
     }
     if (Err)
-      return Err;
+      return std::move(Err);
 
     // Thin archives reference object files outside of the archive file, i.e.
     // files which reside in memory not owned by the caller. Transfer ownership
@@ -795,14 +795,14 @@ BinaryCoverageReader::create(
       for (auto &Buffer : Ar->takeThinBuffers())
         ObjectFileBuffers.push_back(std::move(Buffer));
 
-    return Readers;
+    return std::move(Readers);
   }
 
   auto ReaderOrErr = loadBinaryFormat(std::move(Bin), Arch);
   if (!ReaderOrErr)
     return ReaderOrErr.takeError();
   Readers.push_back(std::move(ReaderOrErr.get()));
-  return Readers;
+  return std::move(Readers);
 }
 
 Error BinaryCoverageReader::readNextRecord(CoverageMappingRecord &Record) {

lib/ProfileData/GCOV.cpp

@@ -711,7 +711,7 @@ FileInfo::openCoveragePath(StringRef CoveragePath) {
     errs() << EC.message() << "\n";
     return std::make_unique<raw_null_ostream>();
   }
-  return OS;
+  return std::move(OS);
 }
 
 /// print -  Print source files with collected line count information.

lib/ProfileData/InstrProf.cpp

@@ -891,9 +891,9 @@ ValueProfData::getValueProfData(const unsigned char *D,
 
   Error E = VPD->checkIntegrity();
   if (E)
-    return E;
+    return std::move(E);
 
-  return VPD;
+  return std::move(VPD);
 }
 
 void ValueProfData::swapBytesToHost(support::endianness Endianness) {

lib/ProfileData/InstrProfReader.cpp

@@ -55,7 +55,7 @@ InstrProfReader::create(const Twine &Path) {
   // Set up the buffer to read.
   auto BufferOrError = setupMemoryBuffer(Path);
   if (Error E = BufferOrError.takeError())
-    return E;
+    return std::move(E);
   return InstrProfReader::create(std::move(BufferOrError.get()));
 }
 
@@ -83,9 +83,9 @@ InstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
 
   // Initialize the reader and return the result.
   if (Error E = initializeReader(*Result))
-    return E;
+    return std::move(E);
 
-  return Result;
+  return std::move(Result);
 }
 
 Expected<std::unique_ptr<IndexedInstrProfReader>>
@@ -93,7 +93,7 @@ IndexedInstrProfReader::create(const Twine &Path, const Twine &RemappingPath) {
   // Set up the buffer to read.
   auto BufferOrError = setupMemoryBuffer(Path);
   if (Error E = BufferOrError.takeError())
-    return E;
+    return std::move(E);
 
   // Set up the remapping buffer if requested.
   std::unique_ptr<MemoryBuffer> RemappingBuffer;
@@ -101,7 +101,7 @@ IndexedInstrProfReader::create(const Twine &Path, const Twine &RemappingPath) {
   if (!RemappingPathStr.empty()) {
     auto RemappingBufferOrError = setupMemoryBuffer(RemappingPathStr);
     if (Error E = RemappingBufferOrError.takeError())
-      return E;
+      return std::move(E);
     RemappingBuffer = std::move(RemappingBufferOrError.get());
   }
 
@@ -124,9 +124,9 @@ IndexedInstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer,
 
   // Initialize the reader and return the result.
   if (Error E = initializeReader(*Result))
-    return E;
+    return std::move(E);
 
-  return Result;
+  return std::move(Result);
 }
 
 void InstrProfIterator::Increment() {
@@ -874,7 +874,7 @@ IndexedInstrProfReader::getInstrProfRecord(StringRef FuncName,
   ArrayRef<NamedInstrProfRecord> Data;
   Error Err = Remapper->getRecords(FuncName, Data);
   if (Err)
-    return Err;
+    return std::move(Err);
   // Found it. Look for counters with the right hash.
   for (unsigned I = 0, E = Data.size(); I < E; ++I) {
     // Check for a match and fill the vector if there is one.

lib/ProfileData/SampleProfReader.cpp

@@ -1250,7 +1250,7 @@ setupMemoryBuffer(const Twine &Filename) {
   if (uint64_t(Buffer->getBufferSize()) > std::numeric_limits<uint32_t>::max())
     return sampleprof_error::too_large;
 
-  return Buffer;
+  return std::move(Buffer);
 }
 
 /// Create a sample profile reader based on the format of the input file.
@@ -1362,7 +1362,7 @@ SampleProfileReader::create(std::unique_ptr<MemoryBuffer> &B, LLVMContext &C,
     return EC;
   }
 
-  return Reader;
+  return std::move(Reader);
 }
 
 // For text and GCC file formats, we compute the summary after reading the

lib/ProfileData/SampleProfWriter.cpp

@@ -607,7 +607,7 @@ SampleProfileWriter::create(std::unique_ptr<raw_ostream> &OS,
     return EC;
 
   Writer->Format = Format;
-  return Writer;
+  return std::move(Writer);
 }
 
 void SampleProfileWriter::computeSummary(

lib/Remarks/BitstreamRemarkParser.cpp

@@ -266,7 +266,7 @@ static Expected<bool> isBlock(BitstreamCursor &Stream, unsigned BlockID) {
     break;
   }
   if (Error E = Stream.JumpToBit(PreviousBitNo))
-    return E;
+    return std::move(E);
   return Result;
 }
 
@@ -316,7 +316,7 @@ remarks::createBitstreamParserFromMeta(
 
   if (Error E = validateMagicNumber(
           StringRef(MagicNumber->data(), MagicNumber->size())))
-    return E;
+    return std::move(E);
 
   auto Parser =
       StrTab ? std::make_unique<BitstreamRemarkParser>(Buf, std::move(*StrTab))
@@ -325,7 +325,7 @@ remarks::createBitstreamParserFromMeta(
   if (ExternalFilePrependPath)
     Parser->ExternalFilePrependPath = std::string(*ExternalFilePrependPath);
 
-  return Parser;
+  return std::move(Parser);
 }
 
 Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::next() {
@@ -334,7 +334,7 @@ Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::next() {
 
   if (!ReadyToParseRemarks) {
     if (Error E = parseMeta())
-      return E;
+      return std::move(E);
     ReadyToParseRemarks = true;
   }
 
@@ -491,7 +491,7 @@ Error BitstreamRemarkParser::processSeparateRemarksMetaMeta(
 Expected<std::unique_ptr<Remark>> BitstreamRemarkParser::parseRemark() {
   BitstreamRemarkParserHelper RemarkHelper(ParserHelper.Stream);
   if (Error E = RemarkHelper.parse())
-    return E;
+    return std::move(E);
 
   return processRemark(RemarkHelper);
 }
@@ -562,7 +562,7 @@ BitstreamRemarkParser::processRemark(BitstreamRemarkParserHelper &Helper) {
     R.Hotness = *Helper.Hotness;
 
   if (!Helper.Args)
-    return Result;
+    return std::move(Result);
 
   for (const BitstreamRemarkParserHelper::Argument &Arg : *Helper.Args) {
     if (!Arg.KeyIdx)
@@ -600,5 +600,5 @@ BitstreamRemarkParser::processRemark(BitstreamRemarkParserHelper &Helper) {
     }
   }
 
-  return Result;
+  return std::move(Result);
 }

lib/Remarks/YAMLRemarkParser.cpp

@@ -164,7 +164,7 @@ remarks::createYAMLParserFromMeta(StringRef Buf,
           : std::make_unique<YAMLRemarkParser>(Buf);
   if (SeparateBuf)
     Result->SeparateBuf = std::move(SeparateBuf);
-  return Result;
+  return std::move(Result);
 }
 
 YAMLRemarkParser::YAMLRemarkParser(StringRef Buf)
@@ -190,7 +190,7 @@ Error YAMLRemarkParser::error() {
 Expected<std::unique_ptr<Remark>>
 YAMLRemarkParser::parseRemark(yaml::Document &RemarkEntry) {
   if (Error E = error())
-    return E;
+    return std::move(E);
 
   yaml::Node *YAMLRoot = RemarkEntry.getRoot();
   if (!YAMLRoot) {
@@ -267,7 +267,7 @@ YAMLRemarkParser::parseRemark(yaml::Document &RemarkEntry) {
     return error("Type, Pass, Name or Function missing.",
                  *RemarkEntry.getRoot());
 
-  return Result;
+  return std::move(Result);
 }
 
 Expected<Type> YAMLRemarkParser::parseType(yaml::MappingNode &Node) {

lib/Support/APFloat.cpp

@@ -2518,7 +2518,7 @@ IEEEFloat::convertFromDecimalString(StringRef str, roundingMode rounding_mode) {
   /* Scan the text.  */
   StringRef::iterator p = str.begin();
   if (Error Err = interpretDecimal(p, str.end(), &D))
-    return Err;
+    return std::move(Err);
 
   /* Handle the quick cases.  First the case of no significant digits,
      i.e. zero, and then exponents that are obviously too large or too

lib/Support/FileCheck.cpp

@@ -86,7 +86,7 @@ Expected<uint64_t> BinaryOperation::eval() const {
       Err = joinErrors(std::move(Err), LeftOp.takeError());
     if (!RightOp)
       Err = joinErrors(std::move(Err), RightOp.takeError());
-    return Err;
+    return std::move(Err);
   }
 
   return EvalBinop(*LeftOp, *RightOp);
@@ -284,7 +284,7 @@ Pattern::parseBinop(StringRef &Expr, std::unique_ptr<ExpressionAST> LeftOp,
                     FileCheckPatternContext *Context, const SourceMgr &SM) {
   Expr = Expr.ltrim(SpaceChars);
   if (Expr.empty())
-    return LeftOp;
+    return std::move(LeftOp);
 
   // Check if this is a supported operation and select a function to perform
   // it.
@@ -425,7 +425,7 @@ Expected<std::unique_ptr<Expression>> Pattern::parseNumericSubstitutionBlock(
     DefinedNumericVariable = *ParseResult;
   }
 
-  return ExpressionPointer;
+  return std::move(ExpressionPointer);
 }
 
 bool Pattern::parsePattern(StringRef PatternStr, StringRef Prefix,

lib/Support/JSON.cpp

@@ -513,7 +513,7 @@ Expected<Value> parse(StringRef JSON) {
   if (P.checkUTF8())
     if (P.parseValue(E))
       if (P.assertEnd())
-        return E;
+        return std::move(E);
   return P.takeError();
 }
 char ParseError::ID = 0;

lib/Support/MemoryBuffer.cpp

@@ -128,7 +128,7 @@ getMemBufferCopyImpl(StringRef InputData, const Twine &BufferName) {
   if (!Buf)
     return make_error_code(errc::not_enough_memory);
   memcpy(Buf->getBufferStart(), InputData.data(), InputData.size());
-  return Buf;
+  return std::move(Buf);
 }
 
 std::unique_ptr<MemoryBuffer>
@@ -398,7 +398,7 @@ getReadWriteFile(const Twine &Filename, uint64_t FileSize, uint64_t MapSize,
                                                          Offset, EC));
   if (EC)
     return EC;
-  return Result;
+  return std::move(Result);
 }
 
 ErrorOr<std::unique_ptr<WriteThroughMemoryBuffer>>
@@ -450,7 +450,7 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
         new (NamedBufferAlloc(Filename)) MemoryBufferMMapFile<MB>(
             RequiresNullTerminator, FD, MapSize, Offset, EC));
     if (!EC)
-      return Result;
+      return std::move(Result);
   }
 
   auto Buf = WritableMemoryBuffer::getNewUninitMemBuffer(MapSize, Filename);
@@ -475,7 +475,7 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
     Offset += *ReadBytes;
   }
 
-  return Buf;
+  return std::move(Buf);
 }
 
 ErrorOr<std::unique_ptr<MemoryBuffer>>

lib/Support/Path.cpp

@@ -1264,7 +1264,7 @@ Expected<TempFile> TempFile::create(const Twine &Model, unsigned Mode) {
     return errorCodeToError(EC);
   }
 #endif
-  return Ret;
+  return std::move(Ret);
 }
 }
 

lib/Support/YAMLTraits.cpp

@@ -388,7 +388,7 @@ std::unique_ptr<Input::HNode> Input::createHNodes(Node *N) {
         break;
       SQHNode->Entries.push_back(std::move(Entry));
     }
-    return SQHNode;
+    return std::move(SQHNode);
   } else if (MappingNode *Map = dyn_cast<MappingNode>(N)) {
     auto mapHNode = std::make_unique<MapHNode>(N);
     for (KeyValueNode &KVN : *Map) {
@@ -413,7 +413,7 @@ std::unique_ptr<Input::HNode> Input::createHNodes(Node *N) {
         break;
       mapHNode->Mapping[KeyStr] = std::move(ValueHNode);
     }
-    return mapHNode;
+    return std::move(mapHNode);
   } else if (isa<NullNode>(N)) {
     return std::make_unique<EmptyHNode>(N);
   } else {

lib/TableGen/JSONBackend.cpp

@@ -54,7 +54,7 @@ json::Value JSONEmitter::translateInit(const Init &I) {
     json::Array array;
     for (unsigned i = 0, limit = Bits->getNumBits(); i < limit; i++)
       array.push_back(translateInit(*Bits->getBit(i)));
-    return array;
+    return std::move(array);
   } else if (auto *Int = dyn_cast<IntInit>(&I)) {
     return Int->getValue();
   } else if (auto *Str = dyn_cast<StringInit>(&I)) {
@@ -65,7 +65,7 @@ json::Value JSONEmitter::translateInit(const Init &I) {
     json::Array array;
     for (auto val : *List)
       array.push_back(translateInit(*val));
-    return array;
+    return std::move(array);
   }
 
   // Init subclasses that we return as JSON objects containing a
@@ -79,17 +79,17 @@ json::Value JSONEmitter::translateInit(const Init &I) {
   if (auto *Def = dyn_cast<DefInit>(&I)) {
     obj["kind"] = "def";
     obj["def"] = Def->getDef()->getName();
-    return obj;
+    return std::move(obj);
   } else if (auto *Var = dyn_cast<VarInit>(&I)) {
     obj["kind"] = "var";
     obj["var"] = Var->getName();
-    return obj;
+    return std::move(obj);
   } else if (auto *VarBit = dyn_cast<VarBitInit>(&I)) {
     if (auto *Var = dyn_cast<VarInit>(VarBit->getBitVar())) {
       obj["kind"] = "varbit";
       obj["var"] = Var->getName();
       obj["index"] = VarBit->getBitNum();
-      return obj;
+      return std::move(obj);
     }
   } else if (auto *Dag = dyn_cast<DagInit>(&I)) {
     obj["kind"] = "dag";
@@ -107,7 +107,7 @@ json::Value JSONEmitter::translateInit(const Init &I) {
       args.push_back(std::move(arg));
     }
     obj["args"] = std::move(args);
-    return obj;
+    return std::move(obj);
   }
 
   // Final fallback: anything that gets past here is simply given a
@@ -116,7 +116,7 @@ json::Value JSONEmitter::translateInit(const Init &I) {
 
   assert(!I.isConcrete());
   obj["kind"] = "complex";
-  return obj;
+  return std::move(obj);
 }
 
 void JSONEmitter::run(raw_ostream &OS) {

lib/TextAPI/ELF/TBEHandler.cpp

@@ -149,7 +149,7 @@ Expected<std::unique_ptr<ELFStub>> elfabi::readTBEFromBuffer(StringRef Buf) {
   if (std::error_code Err = YamlIn.error())
     return createStringError(Err, "YAML failed reading as TBE");
 
-  return Stub;
+  return std::move(Stub);
 }
 
 Error elfabi::writeTBEToOutputStream(raw_ostream &OS, const ELFStub &Stub) {

lib/TextAPI/MachO/TextStub.cpp

@@ -1122,7 +1122,7 @@ TextAPIReader::get(MemoryBufferRef InputBuffer) {
   if (YAMLIn.error())
     return make_error<StringError>(Ctx.ErrorMessage, YAMLIn.error());
 
-  return File;
+  return std::move(File);
 }
 
 Error TextAPIWriter::writeToStream(raw_ostream &OS, const InterfaceFile &File) {

lib/Transforms/IPO/FunctionImport.cpp

@@ -1154,7 +1154,7 @@ Expected<bool> FunctionImporter::importFunctions(
     // If modules were created with lazy metadata loading, materialize it
     // now, before linking it (otherwise this will be a noop).
     if (Error Err = SrcModule->materializeMetadata())
-      return Err;
+      return std::move(Err);
 
     auto &ImportGUIDs = FunctionsToImportPerModule->second;
     // Find the globals to import
@@ -1169,7 +1169,7 @@ Expected<bool> FunctionImporter::importFunctions(
                         << SrcModule->getSourceFileName() << "\n");
       if (Import) {
         if (Error Err = F.materialize())
-          return Err;
+          return std::move(Err);
         if (EnableImportMetadata) {
           // Add 'thinlto_src_module' metadata for statistics and debugging.
           F.setMetadata(
@@ -1191,7 +1191,7 @@ Expected<bool> FunctionImporter::importFunctions(
                         << SrcModule->getSourceFileName() << "\n");
       if (Import) {
         if (Error Err = GV.materialize())
-          return Err;
+          return std::move(Err);
         ImportedGVCount += GlobalsToImport.insert(&GV);
       }
     }
@@ -1205,11 +1205,11 @@ Expected<bool> FunctionImporter::importFunctions(
                         << SrcModule->getSourceFileName() << "\n");
       if (Import) {
         if (Error Err = GA.materialize())
-          return Err;
+          return std::move(Err);
         // Import alias as a copy of its aliasee.
         GlobalObject *Base = GA.getBaseObject();
         if (Error Err = Base->materialize())
-          return Err;
+          return std::move(Err);
         auto *Fn = replaceAliasWithAliasee(SrcModule.get(), &GA);
         LLVM_DEBUG(dbgs() << "Is importing aliasee fn " << Base->getGUID()
                           << " " << Base->getName() << " from "

lib/XRay/FDRRecordProducer.cpp

@@ -101,8 +101,8 @@ FileBasedRecordProducer::findNextBufferExtent() {
         R = std::move(MetadataRecordOrErr.get());
         RecordInitializer RI(E, OffsetPtr);
         if (auto Err = R->apply(RI))
-          return Err;
-        return R;
+          return std::move(Err);
+        return std::move(R);
       }
     }
   }
@@ -132,7 +132,7 @@ Expected<std::unique_ptr<Record>> FileBasedRecordProducer::produce() {
     assert(isa<BufferExtents>(R.get()));
     auto BE = cast<BufferExtents>(R.get());
     CurrentBufferBytes = BE->size();
-    return R;
+    return std::move(R);
   }
 
   //
@@ -172,7 +172,7 @@ Expected<std::unique_ptr<Record>> FileBasedRecordProducer::produce() {
   RecordInitializer RI(E, OffsetPtr);
 
   if (auto Err = R->apply(RI))
-    return Err;
+    return std::move(Err);
 
   // If we encountered a BufferExtents record, we should record the remaining
   // bytes for the current buffer, to determine when we should start ignoring
@@ -191,7 +191,7 @@ Expected<std::unique_ptr<Record>> FileBasedRecordProducer::produce() {
     CurrentBufferBytes -= OffsetPtr - PreReadOffset;
   }
   assert(R != nullptr);
-  return R;
+  return std::move(R);
 }
 
 } // namespace xray

lib/XRay/FileHeaderReader.cpp

@@ -66,7 +66,7 @@ Expected<XRayFileHeader> readBinaryFormatHeader(DataExtractor &HeaderExtractor,
   // Manually advance the offset pointer 16 bytes, after getting a raw memcpy
   // from the underlying data.
   OffsetPtr += 16;
-  return FileHeader;
+  return std::move(FileHeader);
 }
 
 } // namespace xray

lib/XRay/InstrumentationMap.cpp

@@ -232,26 +232,26 @@ llvm::xray::loadInstrumentationMap(StringRef Filename) {
     if (!FdOrErr) {
       // Report the ELF load error if YAML failed.
       consumeError(FdOrErr.takeError());
-      return E;
+      return std::move(E);
     }
 
     uint64_t FileSize;
     if (sys::fs::file_size(Filename, FileSize))
-      return E;
+      return std::move(E);
 
     // If the file is empty, we return the original error.
     if (FileSize == 0)
-      return E;
+      return std::move(E);
 
     // From this point on the errors will be only for the YAML parts, so we
     // consume the errors at this point.
     consumeError(std::move(E));
     if (auto E = loadYAML(*FdOrErr, FileSize, Filename, Map.Sleds,
                           Map.FunctionAddresses, Map.FunctionIds))
-      return E;
+      return std::move(E);
   } else if (auto E = loadObj(Filename, *ObjectFileOrError, Map.Sleds,
                                 Map.FunctionAddresses, Map.FunctionIds)) {
-    return E;
+    return std::move(E);
   }
   return Map;
 }

lib/XRay/Profile.cpp

@@ -90,7 +90,7 @@ static Expected<std::vector<Profile::FuncID>> readPath(DataExtractor &Extractor,
     CurrentOffset = Offset;
     Path.push_back(FuncId);
   } while (FuncId != 0);
-  return Path;
+  return std::move(Path);
 }
 
 static Expected<Profile::Data> readData(DataExtractor &Extractor,
@@ -137,7 +137,7 @@ Expected<std::vector<Profile::FuncID>> Profile::expandPath(PathID P) const {
   std::vector<Profile::FuncID> Path;
   for (auto Node = It->second; Node; Node = Node->Caller)
     Path.push_back(Node->Func);
-  return Path;
+  return std::move(Path);
 }
 
 Profile::PathID Profile::internPath(ArrayRef<FuncID> P) {
@@ -308,7 +308,7 @@ Expected<Profile> loadProfile(StringRef Filename) {
     if (auto E =
             P.addBlock(Profile::Block{Profile::ThreadID{Header.Thread},
                                       {{P.internPath(Path), std::move(Data)}}}))
-      return E;
+      return std::move(E);
   }
 
   return P;
@@ -393,7 +393,7 @@ Expected<Profile> profileFromTrace(const Trace &T) {
             std::vector<std::pair<Profile::PathID, Profile::Data>>(
                 PathsData.begin(), PathsData.end()),
         }))
-      return E;
+      return std::move(E);
   }
 
   return P;

lib/XRay/Trace.cpp

@@ -443,7 +443,7 @@ Expected<Trace> llvm::xray::loadTrace(const DataExtractor &DE, bool Sort) {
     if (Version == 1 || Version == 2 || Version == 3) {
       if (auto E = loadNaiveFormatLog(DE.getData(), DE.isLittleEndian(),
                                       T.FileHeader, T.Records))
-        return E;
+        return std::move(E);
     } else {
       return make_error<StringError>(
           Twine("Unsupported version for Basic/Naive Mode logging: ") +
@@ -455,7 +455,7 @@ Expected<Trace> llvm::xray::loadTrace(const DataExtractor &DE, bool Sort) {
     if (Version >= 1 && Version <= 5) {
       if (auto E = loadFDRLog(DE.getData(), DE.isLittleEndian(), T.FileHeader,
                               T.Records))
-        return E;
+        return std::move(E);
     } else {
       return make_error<StringError>(
           Twine("Unsupported version for FDR Mode logging: ") + Twine(Version),
@@ -464,7 +464,7 @@ Expected<Trace> llvm::xray::loadTrace(const DataExtractor &DE, bool Sort) {
     break;
   default:
     if (auto E = loadYAMLLog(DE.getData(), T.FileHeader, T.Records))
-      return E;
+      return std::move(E);
   }
 
   if (Sort)
@@ -472,5 +472,5 @@ Expected<Trace> llvm::xray::loadTrace(const DataExtractor &DE, bool Sort) {
       return L.TSC < R.TSC;
     });
 
-  return T;
+  return std::move(T);
 }