static bool enterTopLevelModuleBlock(llvm::BitstreamCursor &cursor,
unsigned ID,
bool shouldReadBlockInfo = true) {
auto next = cursor.advance();
if (next.Kind != llvm::BitstreamEntry::SubBlock)
return false;
if (next.ID == llvm::bitc::BLOCKINFO_BLOCK_ID) {
if (shouldReadBlockInfo) {
if (cursor.ReadBlockInfoBlock())
return false;
} else {
if (cursor.SkipBlock())
return false;
}
return enterTopLevelModuleBlock(cursor, ID, false);
}
if (next.ID != ID)
return false;
cursor.EnterSubBlock(ID);
return true;
}
StreamResult DiagLoader::readToNextRecordOrBlock(llvm::BitstreamCursor &Stream,
llvm::StringRef errorContext,
unsigned &blockOrRecordID,
bool atTopLevel) {
blockOrRecordID = 0;
while (!Stream.AtEndOfStream()) {
unsigned Code = Stream.ReadCode();
// Handle the top-level specially.
if (atTopLevel) {
if (Code == llvm::bitc::ENTER_SUBBLOCK) {
unsigned BlockID = Stream.ReadSubBlockID();
if (BlockID == llvm::bitc::BLOCKINFO_BLOCK_ID) {
if (Stream.ReadBlockInfoBlock()) {
reportInvalidFile("Malformed BlockInfoBlock in diagnostics file");
return Read_Failure;
}
continue;
}
blockOrRecordID = BlockID;
return Read_BlockBegin;
}
reportInvalidFile("Only blocks can appear at the top of a "
"diagnostic file");
return Read_Failure;
}
switch ((llvm::bitc::FixedAbbrevIDs)Code) {
case llvm::bitc::ENTER_SUBBLOCK:
blockOrRecordID = Stream.ReadSubBlockID();
return Read_BlockBegin;
case llvm::bitc::END_BLOCK:
if (Stream.ReadBlockEnd()) {
reportInvalidFile("Cannot read end of block");
return Read_Failure;
}
return Read_BlockEnd;
case llvm::bitc::DEFINE_ABBREV:
Stream.ReadAbbrevRecord();
continue;
case llvm::bitc::UNABBREV_RECORD:
reportInvalidFile("Diagnostics file should have no unabbreviated "
"records");
return Read_Failure;
default:
// We found a record.
blockOrRecordID = Code;
return Read_Record;
}
}
if (atTopLevel)
return Read_EndOfStream;
reportInvalidFile(Twine("Premature end of diagnostics file within ").str() +
errorContext.str());
return Read_Failure;
}