Bitcode: Use Expected<T>::takeError() and moveInto() more, NFC

Avoid naming some Expected<T> values in the Bitcode reader by using
takeError() and moveInto() more often. This follows the smaller set of
changes included in 2410fb4.

Author: dexonsmith

llvm/lib/Bitcode/Reader/BitcodeAnalyzer.cpp

@@ -529,10 +529,9 @@ Error BitcodeAnalyzer::decodeMetadataStringsBlob(StringRef Indent,
     if (R.AtEndOfStream())
       return reportError("bad length");
 
-    Expected<uint32_t> MaybeSize = R.ReadVBR(6);
-    if (!MaybeSize)
-      return MaybeSize.takeError();
-    uint32_t Size = MaybeSize.get();
+    uint32_t Size;
+    if (Error E = R.ReadVBR(6).moveInto(Size))
+      return E;
     if (Strings.size() < Size)
       return reportError("truncated chars");
 
@@ -555,21 +554,17 @@ BitcodeAnalyzer::BitcodeAnalyzer(StringRef Buffer,
 
 Error BitcodeAnalyzer::analyze(Optional<BCDumpOptions> O,
                                Optional<StringRef> CheckHash) {
-  Expected<CurStreamTypeType> MaybeType = analyzeHeader(O, Stream);
-  if (!MaybeType)
-    return MaybeType.takeError();
-  else
-    CurStreamType = *MaybeType;
+  if (Error E = analyzeHeader(O, Stream).moveInto(CurStreamType))
+    return E;
 
   Stream.setBlockInfo(&BlockInfo);
 
   // Read block info from BlockInfoStream, if specified.
   // The block info must be a top-level block.
   if (BlockInfoStream) {
     BitstreamCursor BlockInfoCursor(*BlockInfoStream);
-    Expected<CurStreamTypeType> H = analyzeHeader(O, BlockInfoCursor);
-    if (!H)
-      return H.takeError();
+    if (Error E = analyzeHeader(O, BlockInfoCursor).takeError())
+      return E;
 
     while (!BlockInfoCursor.AtEndOfStream()) {
       Expected<unsigned> MaybeCode = BlockInfoCursor.ReadCode();
@@ -582,12 +577,11 @@ Error BitcodeAnalyzer::analyze(Optional<BCDumpOptions> O,
       if (!MaybeBlockID)
         return MaybeBlockID.takeError();
       if (MaybeBlockID.get() == bitc::BLOCKINFO_BLOCK_ID) {
-        Expected<Optional<BitstreamBlockInfo>> MaybeNewBlockInfo =
-            BlockInfoCursor.ReadBlockInfoBlock(/*ReadBlockInfoNames=*/true);
-        if (!MaybeNewBlockInfo)
-          return MaybeNewBlockInfo.takeError();
-        Optional<BitstreamBlockInfo> NewBlockInfo =
-            std::move(MaybeNewBlockInfo.get());
+        Optional<BitstreamBlockInfo> NewBlockInfo;
+        if (Error E =
+                BlockInfoCursor.ReadBlockInfoBlock(/*ReadBlockInfoNames=*/true)
+                    .moveInto(NewBlockInfo))
+          return E;
         if (!NewBlockInfo)
           return reportError("Malformed BlockInfoBlock in block info file");
         BlockInfo = std::move(*NewBlockInfo);
@@ -746,12 +740,10 @@ Error BitcodeAnalyzer::parseBlock(unsigned BlockID, unsigned IndentLevel,
   if (BlockID == bitc::BLOCKINFO_BLOCK_ID) {
     if (O && !O->DumpBlockinfo)
       O->OS << Indent << "<BLOCKINFO_BLOCK/>\n";
-    Expected<Optional<BitstreamBlockInfo>> MaybeNewBlockInfo =
-        Stream.ReadBlockInfoBlock(/*ReadBlockInfoNames=*/true);
-    if (!MaybeNewBlockInfo)
-      return MaybeNewBlockInfo.takeError();
-    Optional<BitstreamBlockInfo> NewBlockInfo =
-        std::move(MaybeNewBlockInfo.get());
+    Optional<BitstreamBlockInfo> NewBlockInfo;
+    if (Error E = Stream.ReadBlockInfoBlock(/*ReadBlockInfoNames=*/true)
+                      .moveInto(NewBlockInfo))
+      return E;
     if (!NewBlockInfo)
       return reportError("Malformed BlockInfoBlock");
     BlockInfo = std::move(*NewBlockInfo);
@@ -796,11 +788,10 @@ Error BitcodeAnalyzer::parseBlock(unsigned BlockID, unsigned IndentLevel,
 
     uint64_t RecordStartBit = Stream.GetCurrentBitNo();
 
-    Expected<BitstreamEntry> MaybeEntry =
-        Stream.advance(BitstreamCursor::AF_DontAutoprocessAbbrevs);
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    BitstreamEntry Entry = MaybeEntry.get();
+    BitstreamEntry Entry;
+    if (Error E = Stream.advance(BitstreamCursor::AF_DontAutoprocessAbbrevs)
+                      .moveInto(Entry))
+      return E;
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:
@@ -847,10 +838,9 @@ Error BitcodeAnalyzer::parseBlock(unsigned BlockID, unsigned IndentLevel,
 
     StringRef Blob;
     uint64_t CurrentRecordPos = Stream.GetCurrentBitNo();
-    Expected<unsigned> MaybeCode = Stream.readRecord(Entry.ID, Record, &Blob);
-    if (!MaybeCode)
-      return MaybeCode.takeError();
-    unsigned Code = MaybeCode.get();
+    unsigned Code;
+    if (Error E = Stream.readRecord(Entry.ID, Record, &Blob).moveInto(Code))
+      return E;
 
     // Increment the # occurrences of this code.
     if (BlockStats.CodeFreq.size() <= Code)

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -241,10 +241,9 @@ static Expected<std::string> readIdentificationCode(BitstreamCursor &Stream) {
         return std::move(Err);
       continue;
     case BitstreamEntry::Record:
-      if (Expected<unsigned> Skipped = Stream.skipRecord(Entry.ID))
-        continue;
-      else
-        return Skipped.takeError();
+      if (Error E = Stream.skipRecord(Entry.ID).takeError())
+        return std::move(E);
+      continue;
     }
   }
 }
@@ -320,10 +319,9 @@ static Expected<bool> hasObjCCategory(BitstreamCursor &Stream) {
       continue;
 
     case BitstreamEntry::Record:
-      if (Expected<unsigned> Skipped = Stream.skipRecord(Entry.ID))
-        continue;
-      else
-        return Skipped.takeError();
+      if (Error E = Stream.skipRecord(Entry.ID).takeError())
+        return std::move(E);
+      continue;
     }
   }
 }
@@ -6772,10 +6770,9 @@ llvm::getBitcodeFileContents(MemoryBufferRef Buffer) {
       continue;
     }
     case BitstreamEntry::Record:
-      if (Expected<unsigned> StreamFailed = Stream.skipRecord(Entry.ID))
-        continue;
-      else
-        return StreamFailed.takeError();
+      if (Error E = Stream.skipRecord(Entry.ID).takeError())
+        return std::move(E);
+      continue;
     }
   }
 }
@@ -6798,12 +6795,9 @@ BitcodeModule::getModuleImpl(LLVMContext &Context, bool MaterializeAll,
   if (IdentificationBit != -1ull) {
     if (Error JumpFailed = Stream.JumpToBit(IdentificationBit))
       return std::move(JumpFailed);
-    Expected<std::string> ProducerIdentificationOrErr =
-        readIdentificationBlock(Stream);
-    if (!ProducerIdentificationOrErr)
-      return ProducerIdentificationOrErr.takeError();
-
-    ProducerIdentification = *ProducerIdentificationOrErr;
+    if (Error E =
+            readIdentificationBlock(Stream).moveInto(ProducerIdentification))
+      return std::move(E);
   }
 
   if (Error JumpFailed = Stream.JumpToBit(ModuleBit))
@@ -6877,10 +6871,9 @@ static Expected<bool> getEnableSplitLTOUnitFlag(BitstreamCursor &Stream,
   SmallVector<uint64_t, 64> Record;
 
   while (true) {
-    Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    BitstreamEntry Entry = MaybeEntry.get();
+    BitstreamEntry Entry;
+    if (Error E = Stream.advanceSkippingSubblocks().moveInto(Entry))
+      return std::move(E);
 
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
@@ -6925,10 +6918,9 @@ Expected<BitcodeLTOInfo> BitcodeModule::getLTOInfo() {
     return std::move(Err);
 
   while (true) {
-    Expected<llvm::BitstreamEntry> MaybeEntry = Stream.advance();
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    llvm::BitstreamEntry Entry = MaybeEntry.get();
+    llvm::BitstreamEntry Entry;
+    if (Error E = Stream.advance().moveInto(Entry))
+      return std::move(E);
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:

llvm/lib/Bitcode/Reader/MetadataLoader.cpp

@@ -697,11 +697,12 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
   // Get the abbrevs, and preload record positions to make them lazy-loadable.
   while (true) {
     uint64_t SavedPos = IndexCursor.GetCurrentBitNo();
-    Expected<BitstreamEntry> MaybeEntry = IndexCursor.advanceSkippingSubblocks(
-        BitstreamCursor::AF_DontPopBlockAtEnd);
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    BitstreamEntry Entry = MaybeEntry.get();
+    BitstreamEntry Entry;
+    if (Error E =
+            IndexCursor
+                .advanceSkippingSubblocks(BitstreamCursor::AF_DontPopBlockAtEnd)
+                .moveInto(Entry))
+      return std::move(E);
 
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
@@ -714,10 +715,9 @@ MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
       // The interesting case.
       ++NumMDRecordLoaded;
       uint64_t CurrentPos = IndexCursor.GetCurrentBitNo();
-      Expected<unsigned> MaybeCode = IndexCursor.skipRecord(Entry.ID);
-      if (!MaybeCode)
-        return MaybeCode.takeError();
-      unsigned Code = MaybeCode.get();
+      unsigned Code;
+      if (Error E = IndexCursor.skipRecord(Entry.ID).moveInto(Code))
+        return std::move(E);
       switch (Code) {
       case bitc::METADATA_STRINGS: {
         // Rewind and parse the strings.
@@ -904,11 +904,12 @@ Expected<bool> MetadataLoader::MetadataLoaderImpl::loadGlobalDeclAttachments() {
   if (Error Err = TempCursor.JumpToBit(GlobalDeclAttachmentPos))
     return std::move(Err);
   while (true) {
-    Expected<BitstreamEntry> MaybeEntry = TempCursor.advanceSkippingSubblocks(
-        BitstreamCursor::AF_DontPopBlockAtEnd);
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    BitstreamEntry Entry = MaybeEntry.get();
+    BitstreamEntry Entry;
+    if (Error E =
+            TempCursor
+                .advanceSkippingSubblocks(BitstreamCursor::AF_DontPopBlockAtEnd)
+                .moveInto(Entry))
+      return std::move(E);
 
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
@@ -1024,10 +1025,9 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) {
 
   // Read all the records.
   while (true) {
-    Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    BitstreamEntry Entry = MaybeEntry.get();
+    BitstreamEntry Entry;
+    if (Error E = Stream.advanceSkippingSubblocks().moveInto(Entry))
+      return E;
 
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
@@ -1081,12 +1081,11 @@ void MetadataLoader::MetadataLoaderImpl::lazyLoadOneMetadata(
           GlobalMetadataBitPosIndex[ID - MDStringRef.size()]))
     report_fatal_error("lazyLoadOneMetadata failed jumping: " +
                        Twine(toString(std::move(Err))));
-  Expected<BitstreamEntry> MaybeEntry = IndexCursor.advanceSkippingSubblocks();
-  if (!MaybeEntry)
+  BitstreamEntry Entry;
+  if (Error E = IndexCursor.advanceSkippingSubblocks().moveInto(Entry))
     // FIXME this drops the error on the floor.
     report_fatal_error("lazyLoadOneMetadata failed advanceSkippingSubblocks: " +
-                       Twine(toString(MaybeEntry.takeError())));
-  BitstreamEntry Entry = MaybeEntry.get();
+                       Twine(toString(std::move(E))));
   ++NumMDRecordLoaded;
   if (Expected<unsigned> MaybeCode =
           IndexCursor.readRecord(Entry.ID, Record, &Blob)) {
@@ -1193,10 +1192,8 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     // Read name of the named metadata.
     SmallString<8> Name(Record.begin(), Record.end());
     Record.clear();
-    Expected<unsigned> MaybeCode = Stream.ReadCode();
-    if (!MaybeCode)
-      return MaybeCode.takeError();
-    Code = MaybeCode.get();
+    if (Error E = Stream.ReadCode().moveInto(Code))
+      return E;
 
     ++NumMDRecordLoaded;
     if (Expected<unsigned> MaybeNextBitCode = Stream.readRecord(Code, Record)) {
@@ -2147,10 +2144,9 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadataStrings(
     if (R.AtEndOfStream())
       return error("Invalid record: metadata strings bad length");
 
-    Expected<uint32_t> MaybeSize = R.ReadVBR(6);
-    if (!MaybeSize)
-      return MaybeSize.takeError();
-    uint32_t Size = MaybeSize.get();
+    uint32_t Size;
+    if (Error E = R.ReadVBR(6).moveInto(Size))
+      return E;
     if (Strings.size() < Size)
       return error("Invalid record: metadata strings truncated chars");
 
@@ -2187,10 +2183,9 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadataAttachment(
   PlaceholderQueue Placeholders;
 
   while (true) {
-    Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    BitstreamEntry Entry = MaybeEntry.get();
+    BitstreamEntry Entry;
+    if (Error E = Stream.advanceSkippingSubblocks().moveInto(Entry))
+      return E;
 
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.
@@ -2291,10 +2286,9 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadataKinds() {
 
   // Read all the records.
   while (true) {
-    Expected<BitstreamEntry> MaybeEntry = Stream.advanceSkippingSubblocks();
-    if (!MaybeEntry)
-      return MaybeEntry.takeError();
-    BitstreamEntry Entry = MaybeEntry.get();
+    BitstreamEntry Entry;
+    if (Error E = Stream.advanceSkippingSubblocks().moveInto(Entry))
+      return E;
 
     switch (Entry.Kind) {
     case BitstreamEntry::SubBlock: // Handled for us already.