lib/Frontend/SerializedDiagnosticReader.cpp - clang - Git at Google

 //===- SerializedDiagnosticReader.cpp - Reads diagnostics -----------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include "clang/Frontend/SerializedDiagnosticReader.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/FileSystemOptions.h"
 #include "clang/Frontend/SerializedDiagnostics.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Bitstream/BitCodes.h"
 #include "llvm/Bitstream/BitstreamReader.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/ManagedStatic.h"
 #include <cstdint>
 #include <system_error>

 using namespace clang;
 using namespace serialized_diags;

 std::error_code SerializedDiagnosticReader::readDiagnostics(StringRef File) {
   // Open the diagnostics file.
   FileSystemOptions FO;
   FileManager FileMgr(FO);

   auto Buffer = FileMgr.getBufferForFile(File);
   if (!Buffer)
     return SDError::CouldNotLoad;

   llvm::BitstreamCursor Stream(**Buffer);
   Optional<llvm::BitstreamBlockInfo> BlockInfo;

   if (Stream.AtEndOfStream())
     return SDError::InvalidSignature;

   // Sniff for the signature.
   for (unsigned char C : {'D', 'I', 'A', 'G'}) {
     if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Stream.Read(8)) {
       if (Res.get() == C)
         continue;
     } else {
       // FIXME this drops the error on the floor.
       consumeError(Res.takeError());
     }
     return SDError::InvalidSignature;
   }

   // Read the top level blocks.
   while (!Stream.AtEndOfStream()) {
     if (Expected<unsigned> Res = Stream.ReadCode()) {
       if (Res.get() != llvm::bitc::ENTER_SUBBLOCK)
         return SDError::InvalidDiagnostics;
     } else {
       // FIXME this drops the error on the floor.
       consumeError(Res.takeError());
       return SDError::InvalidDiagnostics;
     }

     std::error_code EC;
     Expected<unsigned> MaybeSubBlockID = Stream.ReadSubBlockID();
     if (!MaybeSubBlockID) {
       // FIXME this drops the error on the floor.
       consumeError(MaybeSubBlockID.takeError());
       return SDError::InvalidDiagnostics;
     }

     switch (MaybeSubBlockID.get()) {
     case llvm::bitc::BLOCKINFO_BLOCK_ID: {
       Expected<Optional<llvm::BitstreamBlockInfo>> MaybeBlockInfo =
           Stream.ReadBlockInfoBlock();
       if (!MaybeBlockInfo) {
         // FIXME this drops the error on the floor.
         consumeError(MaybeBlockInfo.takeError());
         return SDError::InvalidDiagnostics;
       }
       BlockInfo = std::move(MaybeBlockInfo.get());
     }
       if (!BlockInfo)
         return SDError::MalformedBlockInfoBlock;
       Stream.setBlockInfo(&*BlockInfo);
       continue;
     case BLOCK_META:
       if ((EC = readMetaBlock(Stream)))
         return EC;
       continue;
     case BLOCK_DIAG:
       if ((EC = readDiagnosticBlock(Stream)))
         return EC;
       continue;
     default:
       if (llvm::Error Err = Stream.SkipBlock()) {
         // FIXME this drops the error on the floor.
         consumeError(std::move(Err));
         return SDError::MalformedTopLevelBlock;
       }
       continue;
     }
   }
   return {};
 }

 enum class SerializedDiagnosticReader::Cursor {
   Record = 1,
   BlockEnd,
   BlockBegin
 };

 llvm::ErrorOr<SerializedDiagnosticReader::Cursor>
 SerializedDiagnosticReader::skipUntilRecordOrBlock(
     llvm::BitstreamCursor &Stream, unsigned &BlockOrRecordID) {
   BlockOrRecordID = 0;

   while (!Stream.AtEndOfStream()) {
     unsigned Code;
     if (Expected<unsigned> Res = Stream.ReadCode())
       Code = Res.get();
     else
       return llvm::errorToErrorCode(Res.takeError());

     if (Code >= static_cast<unsigned>(llvm::bitc::FIRST_APPLICATION_ABBREV)) {
       // We found a record.
       BlockOrRecordID = Code;
       return Cursor::Record;
     }
     switch (static_cast<llvm::bitc::FixedAbbrevIDs>(Code)) {
     case llvm::bitc::ENTER_SUBBLOCK:
       if (Expected<unsigned> Res = Stream.ReadSubBlockID())
         BlockOrRecordID = Res.get();
       else
         return llvm::errorToErrorCode(Res.takeError());
       return Cursor::BlockBegin;

     case llvm::bitc::END_BLOCK:
       if (Stream.ReadBlockEnd())
         return SDError::InvalidDiagnostics;
       return Cursor::BlockEnd;

     case llvm::bitc::DEFINE_ABBREV:
       if (llvm::Error Err = Stream.ReadAbbrevRecord())
         return llvm::errorToErrorCode(std::move(Err));
       continue;

     case llvm::bitc::UNABBREV_RECORD:
       return SDError::UnsupportedConstruct;

     case llvm::bitc::FIRST_APPLICATION_ABBREV:
       llvm_unreachable("Unexpected abbrev id.");
     }
   }

   return SDError::InvalidDiagnostics;
 }

 std::error_code
 SerializedDiagnosticReader::readMetaBlock(llvm::BitstreamCursor &Stream) {
   if (llvm::Error Err =
           Stream.EnterSubBlock(clang::serialized_diags::BLOCK_META)) {
     // FIXME this drops the error on the floor.
     consumeError(std::move(Err));
     return SDError::MalformedMetadataBlock;
   }

   bool VersionChecked = false;

   while (true) {
     unsigned BlockOrCode = 0;
     llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
     if (!Res)
       Res.getError();

     switch (Res.get()) {
     case Cursor::Record:
       break;
     case Cursor::BlockBegin:
       if (llvm::Error Err = Stream.SkipBlock()) {
         // FIXME this drops the error on the floor.
         consumeError(std::move(Err));
         return SDError::MalformedMetadataBlock;
       }
       LLVM_FALLTHROUGH;
     case Cursor::BlockEnd:
       if (!VersionChecked)
         return SDError::MissingVersion;
       return {};
     }

     SmallVector<uint64_t, 1> Record;
     Expected<unsigned> MaybeRecordID = Stream.readRecord(BlockOrCode, Record);
     if (!MaybeRecordID)
       return errorToErrorCode(MaybeRecordID.takeError());
     unsigned RecordID = MaybeRecordID.get();

     if (RecordID == RECORD_VERSION) {
       if (Record.size() < 1)
         return SDError::MissingVersion;
       if (Record[0] > VersionNumber)
         return SDError::VersionMismatch;
       VersionChecked = true;
     }
   }
 }

 std::error_code
 SerializedDiagnosticReader::readDiagnosticBlock(llvm::BitstreamCursor &Stream) {
   if (llvm::Error Err =
           Stream.EnterSubBlock(clang::serialized_diags::BLOCK_DIAG)) {
     // FIXME this drops the error on the floor.
     consumeError(std::move(Err));
     return SDError::MalformedDiagnosticBlock;
   }

   std::error_code EC;
   if ((EC = visitStartOfDiagnostic()))
     return EC;

   SmallVector<uint64_t, 16> Record;
   while (true) {
     unsigned BlockOrCode = 0;
     llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
     if (!Res)
       Res.getError();

     switch (Res.get()) {
     case Cursor::BlockBegin:
       // The only blocks we care about are subdiagnostics.
       if (BlockOrCode == serialized_diags::BLOCK_DIAG) {
         if ((EC = readDiagnosticBlock(Stream)))
           return EC;
       } else if (llvm::Error Err = Stream.SkipBlock()) {
         // FIXME this drops the error on the floor.
         consumeError(std::move(Err));
         return SDError::MalformedSubBlock;
       }
       continue;
     case Cursor::BlockEnd:
       if ((EC = visitEndOfDiagnostic()))
         return EC;
       return {};
     case Cursor::Record:
       break;
     }

     // Read the record.
     Record.clear();
     StringRef Blob;
     Expected<unsigned> MaybeRecID =
         Stream.readRecord(BlockOrCode, Record, &Blob);
     if (!MaybeRecID)
       return errorToErrorCode(MaybeRecID.takeError());
     unsigned RecID = MaybeRecID.get();

     if (RecID < serialized_diags::RECORD_FIRST ||
         RecID > serialized_diags::RECORD_LAST)
       continue;

     switch ((RecordIDs)RecID) {
     case RECORD_CATEGORY:
       // A category has ID and name size.
       if (Record.size() != 2)
         return SDError::MalformedDiagnosticRecord;
       if ((EC = visitCategoryRecord(Record[0], Blob)))
         return EC;
       continue;
     case RECORD_DIAG:
       // A diagnostic has severity, location (4), category, flag, and message
       // size.
       if (Record.size() != 8)
         return SDError::MalformedDiagnosticRecord;
       if ((EC = visitDiagnosticRecord(
                Record[0], Location(Record[1], Record[2], Record[3], Record[4]),
                Record[5], Record[6], Blob)))
         return EC;
       continue;
     case RECORD_DIAG_FLAG:
       // A diagnostic flag has ID and name size.
       if (Record.size() != 2)
         return SDError::MalformedDiagnosticRecord;
       if ((EC = visitDiagFlagRecord(Record[0], Blob)))
         return EC;
       continue;
     case RECORD_FILENAME:
       // A filename has ID, size, timestamp, and name size. The size and
       // timestamp are legacy fields that are always zero these days.
       if (Record.size() != 4)
         return SDError::MalformedDiagnosticRecord;
       if ((EC = visitFilenameRecord(Record[0], Record[1], Record[2], Blob)))
         return EC;
       continue;
     case RECORD_FIXIT:
       // A fixit has two locations (4 each) and message size.
       if (Record.size() != 9)
         return SDError::MalformedDiagnosticRecord;
       if ((EC = visitFixitRecord(
                Location(Record[0], Record[1], Record[2], Record[3]),
                Location(Record[4], Record[5], Record[6], Record[7]), Blob)))
         return EC;
       continue;
     case RECORD_SOURCE_RANGE:
       // A source range is two locations (4 each).
       if (Record.size() != 8)
         return SDError::MalformedDiagnosticRecord;
       if ((EC = visitSourceRangeRecord(
                Location(Record[0], Record[1], Record[2], Record[3]),
                Location(Record[4], Record[5], Record[6], Record[7]))))
         return EC;
       continue;
     case RECORD_VERSION:
       // A version is just a number.
       if (Record.size() != 1)
         return SDError::MalformedDiagnosticRecord;
       if ((EC = visitVersionRecord(Record[0])))
         return EC;
       continue;
     }
   }
 }

 namespace {

 class SDErrorCategoryType final : public std::error_category {
   const char *name() const noexcept override {
     return "clang.serialized_diags";
   }

   std::string message(int IE) const override {
     auto E = static_cast<SDError>(IE);
     switch (E) {
     case SDError::CouldNotLoad:
       return "Failed to open diagnostics file";
     case SDError::InvalidSignature:
       return "Invalid diagnostics signature";
     case SDError::InvalidDiagnostics:
       return "Parse error reading diagnostics";
     case SDError::MalformedTopLevelBlock:
       return "Malformed block at top-level of diagnostics";
     case SDError::MalformedSubBlock:
       return "Malformed sub-block in a diagnostic";
     case SDError::MalformedBlockInfoBlock:
       return "Malformed BlockInfo block";
     case SDError::MalformedMetadataBlock:
       return "Malformed Metadata block";
     case SDError::MalformedDiagnosticBlock:
       return "Malformed Diagnostic block";
     case SDError::MalformedDiagnosticRecord:
       return "Malformed Diagnostic record";
     case SDError::MissingVersion:
       return "No version provided in diagnostics";
     case SDError::VersionMismatch:
       return "Unsupported diagnostics version";
     case SDError::UnsupportedConstruct:
       return "Bitcode constructs that are not supported in diagnostics appear";
     case SDError::HandlerFailed:
       return "Generic error occurred while handling a record";
     }
     llvm_unreachable("Unknown error type!");
   }
 };

 } // namespace

 static llvm::ManagedStatic<SDErrorCategoryType> ErrorCategory;
 const std::error_category &clang::serialized_diags::SDErrorCategory() {
   return *ErrorCategory;
 }
	//===- SerializedDiagnosticReader.cpp - Reads diagnostics -----------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include "clang/Frontend/SerializedDiagnosticReader.h"
	#include "clang/Basic/FileManager.h"
	#include "clang/Basic/FileSystemOptions.h"
	#include "clang/Frontend/SerializedDiagnostics.h"
	#include "llvm/ADT/Optional.h"
	#include "llvm/ADT/SmallVector.h"
	#include "llvm/ADT/StringRef.h"
	#include "llvm/Bitstream/BitCodes.h"
	#include "llvm/Bitstream/BitstreamReader.h"
	#include "llvm/Support/Compiler.h"
	#include "llvm/Support/ErrorHandling.h"
	#include "llvm/Support/ErrorOr.h"
	#include "llvm/Support/ManagedStatic.h"
	#include <cstdint>
	#include <system_error>

	using namespace clang;
	using namespace serialized_diags;

	std::error_code SerializedDiagnosticReader::readDiagnostics(StringRef File) {
	// Open the diagnostics file.
	FileSystemOptions FO;
	FileManager FileMgr(FO);

	auto Buffer = FileMgr.getBufferForFile(File);
	if (!Buffer)
	return SDError::CouldNotLoad;

	llvm::BitstreamCursor Stream(**Buffer);
	Optional<llvm::BitstreamBlockInfo> BlockInfo;

	if (Stream.AtEndOfStream())
	return SDError::InvalidSignature;

	// Sniff for the signature.
	for (unsigned char C : {'D', 'I', 'A', 'G'}) {
	if (Expected<llvm::SimpleBitstreamCursor::word_t> Res = Stream.Read(8)) {
	if (Res.get() == C)
	continue;
	} else {
	// FIXME this drops the error on the floor.
	consumeError(Res.takeError());
	}
	return SDError::InvalidSignature;
	}

	// Read the top level blocks.
	while (!Stream.AtEndOfStream()) {
	if (Expected<unsigned> Res = Stream.ReadCode()) {
	if (Res.get() != llvm::bitc::ENTER_SUBBLOCK)
	return SDError::InvalidDiagnostics;
	} else {
	// FIXME this drops the error on the floor.
	consumeError(Res.takeError());
	return SDError::InvalidDiagnostics;
	}

	std::error_code EC;
	Expected<unsigned> MaybeSubBlockID = Stream.ReadSubBlockID();
	if (!MaybeSubBlockID) {
	// FIXME this drops the error on the floor.
	consumeError(MaybeSubBlockID.takeError());
	return SDError::InvalidDiagnostics;
	}

	switch (MaybeSubBlockID.get()) {
	case llvm::bitc::BLOCKINFO_BLOCK_ID: {
	Expected<Optional<llvm::BitstreamBlockInfo>> MaybeBlockInfo =
	Stream.ReadBlockInfoBlock();
	if (!MaybeBlockInfo) {
	// FIXME this drops the error on the floor.
	consumeError(MaybeBlockInfo.takeError());
	return SDError::InvalidDiagnostics;
	}
	BlockInfo = std::move(MaybeBlockInfo.get());
	}
	if (!BlockInfo)
	return SDError::MalformedBlockInfoBlock;
	Stream.setBlockInfo(&*BlockInfo);
	continue;
	case BLOCK_META:
	if ((EC = readMetaBlock(Stream)))
	return EC;
	continue;
	case BLOCK_DIAG:
	if ((EC = readDiagnosticBlock(Stream)))
	return EC;
	continue;
	default:
	if (llvm::Error Err = Stream.SkipBlock()) {
	// FIXME this drops the error on the floor.
	consumeError(std::move(Err));
	return SDError::MalformedTopLevelBlock;
	}
	continue;
	}
	}
	return {};
	}

	enum class SerializedDiagnosticReader::Cursor {
	Record = 1,
	BlockEnd,
	BlockBegin
	};

	llvm::ErrorOr<SerializedDiagnosticReader::Cursor>
	SerializedDiagnosticReader::skipUntilRecordOrBlock(
	llvm::BitstreamCursor &Stream, unsigned &BlockOrRecordID) {
	BlockOrRecordID = 0;

	while (!Stream.AtEndOfStream()) {
	unsigned Code;
	if (Expected<unsigned> Res = Stream.ReadCode())
	Code = Res.get();
	else
	return llvm::errorToErrorCode(Res.takeError());

	if (Code >= static_cast<unsigned>(llvm::bitc::FIRST_APPLICATION_ABBREV)) {
	// We found a record.
	BlockOrRecordID = Code;
	return Cursor::Record;
	}
	switch (static_cast<llvm::bitc::FixedAbbrevIDs>(Code)) {
	case llvm::bitc::ENTER_SUBBLOCK:
	if (Expected<unsigned> Res = Stream.ReadSubBlockID())
	BlockOrRecordID = Res.get();
	else
	return llvm::errorToErrorCode(Res.takeError());
	return Cursor::BlockBegin;

	case llvm::bitc::END_BLOCK:
	if (Stream.ReadBlockEnd())
	return SDError::InvalidDiagnostics;
	return Cursor::BlockEnd;

	case llvm::bitc::DEFINE_ABBREV:
	if (llvm::Error Err = Stream.ReadAbbrevRecord())
	return llvm::errorToErrorCode(std::move(Err));
	continue;

	case llvm::bitc::UNABBREV_RECORD:
	return SDError::UnsupportedConstruct;

	case llvm::bitc::FIRST_APPLICATION_ABBREV:
	llvm_unreachable("Unexpected abbrev id.");
	}
	}

	return SDError::InvalidDiagnostics;
	}

	std::error_code
	SerializedDiagnosticReader::readMetaBlock(llvm::BitstreamCursor &Stream) {
	if (llvm::Error Err =
	Stream.EnterSubBlock(clang::serialized_diags::BLOCK_META)) {
	// FIXME this drops the error on the floor.
	consumeError(std::move(Err));
	return SDError::MalformedMetadataBlock;
	}

	bool VersionChecked = false;

	while (true) {
	unsigned BlockOrCode = 0;
	llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
	if (!Res)
	Res.getError();

	switch (Res.get()) {
	case Cursor::Record:
	break;
	case Cursor::BlockBegin:
	if (llvm::Error Err = Stream.SkipBlock()) {
	// FIXME this drops the error on the floor.
	consumeError(std::move(Err));
	return SDError::MalformedMetadataBlock;
	}
	LLVM_FALLTHROUGH;
	case Cursor::BlockEnd:
	if (!VersionChecked)
	return SDError::MissingVersion;
	return {};
	}

	SmallVector<uint64_t, 1> Record;
	Expected<unsigned> MaybeRecordID = Stream.readRecord(BlockOrCode, Record);
	if (!MaybeRecordID)
	return errorToErrorCode(MaybeRecordID.takeError());
	unsigned RecordID = MaybeRecordID.get();

	if (RecordID == RECORD_VERSION) {
	if (Record.size() < 1)
	return SDError::MissingVersion;
	if (Record[0] > VersionNumber)
	return SDError::VersionMismatch;
	VersionChecked = true;
	}
	}
	}

	std::error_code
	SerializedDiagnosticReader::readDiagnosticBlock(llvm::BitstreamCursor &Stream) {
	if (llvm::Error Err =
	Stream.EnterSubBlock(clang::serialized_diags::BLOCK_DIAG)) {
	// FIXME this drops the error on the floor.
	consumeError(std::move(Err));
	return SDError::MalformedDiagnosticBlock;
	}

	std::error_code EC;
	if ((EC = visitStartOfDiagnostic()))
	return EC;

	SmallVector<uint64_t, 16> Record;
	while (true) {
	unsigned BlockOrCode = 0;
	llvm::ErrorOr<Cursor> Res = skipUntilRecordOrBlock(Stream, BlockOrCode);
	if (!Res)
	Res.getError();

	switch (Res.get()) {
	case Cursor::BlockBegin:
	// The only blocks we care about are subdiagnostics.
	if (BlockOrCode == serialized_diags::BLOCK_DIAG) {
	if ((EC = readDiagnosticBlock(Stream)))
	return EC;
	} else if (llvm::Error Err = Stream.SkipBlock()) {
	// FIXME this drops the error on the floor.
	consumeError(std::move(Err));
	return SDError::MalformedSubBlock;
	}
	continue;
	case Cursor::BlockEnd:
	if ((EC = visitEndOfDiagnostic()))
	return EC;
	return {};
	case Cursor::Record:
	break;
	}

	// Read the record.
	Record.clear();
	StringRef Blob;
	Expected<unsigned> MaybeRecID =
	Stream.readRecord(BlockOrCode, Record, &Blob);
	if (!MaybeRecID)
	return errorToErrorCode(MaybeRecID.takeError());
	unsigned RecID = MaybeRecID.get();

	if (RecID < serialized_diags::RECORD_FIRST \|\|
	RecID > serialized_diags::RECORD_LAST)
	continue;

	switch ((RecordIDs)RecID) {
	case RECORD_CATEGORY:
	// A category has ID and name size.
	if (Record.size() != 2)
	return SDError::MalformedDiagnosticRecord;
	if ((EC = visitCategoryRecord(Record[0], Blob)))
	return EC;
	continue;
	case RECORD_DIAG:
	// A diagnostic has severity, location (4), category, flag, and message
	// size.
	if (Record.size() != 8)
	return SDError::MalformedDiagnosticRecord;
	if ((EC = visitDiagnosticRecord(
	Record[0], Location(Record[1], Record[2], Record[3], Record[4]),
	Record[5], Record[6], Blob)))
	return EC;
	continue;
	case RECORD_DIAG_FLAG:
	// A diagnostic flag has ID and name size.
	if (Record.size() != 2)
	return SDError::MalformedDiagnosticRecord;
	if ((EC = visitDiagFlagRecord(Record[0], Blob)))
	return EC;
	continue;
	case RECORD_FILENAME:
	// A filename has ID, size, timestamp, and name size. The size and
	// timestamp are legacy fields that are always zero these days.
	if (Record.size() != 4)
	return SDError::MalformedDiagnosticRecord;
	if ((EC = visitFilenameRecord(Record[0], Record[1], Record[2], Blob)))
	return EC;
	continue;
	case RECORD_FIXIT:
	// A fixit has two locations (4 each) and message size.
	if (Record.size() != 9)
	return SDError::MalformedDiagnosticRecord;
	if ((EC = visitFixitRecord(
	Location(Record[0], Record[1], Record[2], Record[3]),
	Location(Record[4], Record[5], Record[6], Record[7]), Blob)))
	return EC;
	continue;
	case RECORD_SOURCE_RANGE:
	// A source range is two locations (4 each).
	if (Record.size() != 8)
	return SDError::MalformedDiagnosticRecord;
	if ((EC = visitSourceRangeRecord(
	Location(Record[0], Record[1], Record[2], Record[3]),
	Location(Record[4], Record[5], Record[6], Record[7]))))
	return EC;
	continue;
	case RECORD_VERSION:
	// A version is just a number.
	if (Record.size() != 1)
	return SDError::MalformedDiagnosticRecord;
	if ((EC = visitVersionRecord(Record[0])))
	return EC;
	continue;
	}
	}
	}

	namespace {

	class SDErrorCategoryType final : public std::error_category {
	const char *name() const noexcept override {
	return "clang.serialized_diags";
	}

	std::string message(int IE) const override {
	auto E = static_cast<SDError>(IE);
	switch (E) {
	case SDError::CouldNotLoad:
	return "Failed to open diagnostics file";
	case SDError::InvalidSignature:
	return "Invalid diagnostics signature";
	case SDError::InvalidDiagnostics:
	return "Parse error reading diagnostics";
	case SDError::MalformedTopLevelBlock:
	return "Malformed block at top-level of diagnostics";
	case SDError::MalformedSubBlock:
	return "Malformed sub-block in a diagnostic";
	case SDError::MalformedBlockInfoBlock:
	return "Malformed BlockInfo block";
	case SDError::MalformedMetadataBlock:
	return "Malformed Metadata block";
	case SDError::MalformedDiagnosticBlock:
	return "Malformed Diagnostic block";
	case SDError::MalformedDiagnosticRecord:
	return "Malformed Diagnostic record";
	case SDError::MissingVersion:
	return "No version provided in diagnostics";
	case SDError::VersionMismatch:
	return "Unsupported diagnostics version";
	case SDError::UnsupportedConstruct:
	return "Bitcode constructs that are not supported in diagnostics appear";
	case SDError::HandlerFailed:
	return "Generic error occurred while handling a record";
	}
	llvm_unreachable("Unknown error type!");
	}
	};

	} // namespace

	static llvm::ManagedStatic<SDErrorCategoryType> ErrorCategory;
	const std::error_category &clang::serialized_diags::SDErrorCategory() {
	return *ErrorCategory;
	}