LLVM: llvm::BitstreamCursor Class Reference (original) (raw)

This represents a position within a bitcode file, implemented on top of a SimpleBitstreamCursor. More...

#include "[llvm/Bitstream/BitstreamReader.h](BitstreamReader%5F8h%5Fsource.html)"

Public Types
enum { AF_DontPopBlockAtEnd = 1 , AF_DontAutoprocessAbbrevs = 2 }
Flags that modify the behavior of advance(). More...
Public Member Functions
BitstreamCursor ()=default
BitstreamCursor (ArrayRef< uint8_t > BitcodeBytes)
BitstreamCursor (StringRef BitcodeBytes)
BitstreamCursor (MemoryBufferRef BitcodeBytes)
unsigned getAbbrevIDWidth () const
Return the number of bits used to encode an abbrev #.
Expected< BitstreamEntry > advance (unsigned Flags=0)
Advance the current bitstream, returning the next entry in the stream.
Expected< BitstreamEntry > advanceSkippingSubblocks (unsigned Flags=0)
This is a convenience function for clients that don't expect any subblocks.
Expected< unsigned > ReadCode ()
Expected< unsigned > ReadSubBlockID ()
Having read the ENTER_SUBBLOCK code, read the BlockID for the block.
Error SkipBlock ()
Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body of this block.
LLVM_ABI Error EnterSubBlock (unsigned BlockID, unsigned *NumWordsP=nullptr)
Having read the ENTER_SUBBLOCK abbrevid, and enter the block.
bool ReadBlockEnd ()
Expected< const BitCodeAbbrev * > getAbbrev (unsigned AbbrevID)
Return the abbreviation for the specified AbbrevId.
LLVM_ABI Expected< unsigned > skipRecord (unsigned AbbrevID)
Read the current record and discard it, returning the code for the record.
LLVM_ABI Expected< unsigned > readRecord (unsigned AbbrevID, SmallVectorImpl< uint64_t > &Vals, StringRef *Blob=nullptr)
LLVM_ABI Error ReadAbbrevRecord ()
LLVM_ABI Expected< std::optional< BitstreamBlockInfo > > ReadBlockInfoBlock (bool ReadBlockInfoNames=false)
Read and return a block info block from the bitstream.
void setBlockInfo (BitstreamBlockInfo *BI)
Set the block info to be used by this BitstreamCursor to interpret abbreviated records.
bool AtEndOfStream ()
bool canSkipToPos (size_t pos) const
Error fillCurWord ()
ArrayRef< uint8_t > getBitcodeBytes () const
uint64_t GetCurrentBitNo () const
Return the bit # of the bit we are reading.
uint64_t getCurrentByteNo () const
const uint8_t * getPointerToByte (uint64_t ByteNo, uint64_t NumBytes)
Get a pointer into the bitstream at the specified byte offset.
Error JumpToBit (uint64_t BitNo)
Reset the stream to the specified bit number.
Expected< word_t > Read (unsigned NumBits)
Expected< uint32_t > ReadVBR (const unsigned NumBits)
Expected< uint64_t > ReadVBR64 (const unsigned NumBits)
size_t SizeInBytes () const
Return the size of the stream in bytes.
void skipToEnd ()
Skip to the end of the file.
Static Public Attributes
static const size_t MaxChunkSize = 32

This represents a position within a bitcode file, implemented on top of a SimpleBitstreamCursor.

Unlike iterators, BitstreamCursors are heavy-weight objects that should not be passed by value.

Definition at line 358 of file BitstreamReader.h.

◆ anonymous enum

Flags that modify the behavior of advance().

Enumerator
AF_DontPopBlockAtEnd If this flag is used, the advance() method does not automatically pop the block scope when the end of a block is reached.
AF_DontAutoprocessAbbrevs If this flag is used, abbrev entries are returned just like normal records.

Definition at line 407 of file BitstreamReader.h.

llvm::BitstreamCursor::BitstreamCursor ( ) default

◆ BitstreamCursor() [2/4]

llvm::BitstreamCursor::BitstreamCursor ( ArrayRef< uint8_t > BitcodeBytes) inlineexplicit

◆ BitstreamCursor() [3/4]

llvm::BitstreamCursor::BitstreamCursor ( StringRef BitcodeBytes) inlineexplicit

◆ BitstreamCursor() [4/4]

llvm::BitstreamCursor::BitstreamCursor ( MemoryBufferRef BitcodeBytes) inlineexplicit

◆ advance()

Advance the current bitstream, returning the next entry in the stream.

Definition at line 418 of file BitstreamReader.h.

References AF_DontAutoprocessAbbrevs, AF_DontPopBlockAtEnd, AtEndOfStream(), llvm::bitc::DEFINE_ABBREV, llvm::bitc::END_BLOCK, llvm::bitc::ENTER_SUBBLOCK, llvm::Expected< T >::get(), llvm::BitstreamEntry::getEndBlock(), llvm::BitstreamEntry::getError(), llvm::BitstreamEntry::getRecord(), llvm::BitstreamEntry::getSubBlock(), ReadAbbrevRecord(), ReadBlockEnd(), ReadCode(), ReadSubBlockID(), and llvm::Expected< T >::takeError().

Referenced by advanceSkippingSubblocks(), expectSubBlock(), llvm::getBitcodeFileContents(), llvm::BitcodeModule::getLTOInfo(), hasObjCCategory(), jumpToValueSymbolTable(), readBlobInRecord(), readIdentificationBlock(), readIdentificationCode(), and readTriple().

◆ advanceSkippingSubblocks()

◆ AtEndOfStream()

bool llvm::SimpleBitstreamCursor::AtEndOfStream ( ) inline

◆ canSkipToPos()

bool llvm::SimpleBitstreamCursor::canSkipToPos ( size_t pos) const inline

◆ EnterSubBlock()

Having read the ENTER_SUBBLOCK abbrevid, and enter the block.

Having read the ENTER_SUBBLOCK abbrevid, enter the block.

Definition at line 26 of file BitstreamReader.cpp.

References llvm::append_range(), AtEndOfStream(), llvm::Block, llvm::bitc::BlockSizeWidth, llvm::bitc::CodeLenWidth, llvm::createStringError(), llvm::Expected< T >::get(), MaxChunkSize, llvm::Read, ReadVBR(), llvm::SimpleBitstreamCursor::SkipToFourByteBoundary(), llvm::Error::success(), and llvm::Expected< T >::takeError().

Referenced by getEnableSplitLTOUnitAndUnifiedFlag(), llvm::BitcodeModule::getLTOInfo(), hasObjCCategoryInModule(), readBlobInRecord(), ReadBlockInfoBlock(), readIdentificationBlock(), and readModuleTriple().

◆ fillCurWord()

Error llvm::SimpleBitstreamCursor::fillCurWord ( ) inline

◆ getAbbrev()

◆ getAbbrevIDWidth()

unsigned llvm::BitstreamCursor::getAbbrevIDWidth ( ) const inline

Return the number of bits used to encode an abbrev #.

Definition at line 404 of file BitstreamReader.h.

◆ getBitcodeBytes()

ArrayRef< uint8_t > llvm::SimpleBitstreamCursor::getBitcodeBytes ( ) const inline

◆ GetCurrentBitNo()

uint64_t llvm::SimpleBitstreamCursor::GetCurrentBitNo ( ) const inline

◆ getCurrentByteNo()

uint64_t llvm::SimpleBitstreamCursor::getCurrentByteNo ( ) const inline

◆ getPointerToByte()

Get a pointer into the bitstream at the specified byte offset.

Definition at line 149 of file BitstreamReader.h.

◆ JumpToBit()

Error llvm::SimpleBitstreamCursor::JumpToBit ( uint64_t BitNo) inline

◆ Read()

◆ ReadAbbrevRecord()

Error BitstreamCursor::ReadAbbrevRecord ( )

Definition at line 364 of file BitstreamReader.cpp.

References llvm::Data, error, llvm::BitCodeAbbrevOp::Fixed, llvm::Expected< T >::get(), llvm::BitCodeAbbrevOp::hasEncodingData(), llvm::BitCodeAbbrevOp::isValidEncoding(), MaxChunkSize, llvm::Read, ReadVBR(), ReadVBR64(), llvm::Error::success(), llvm::Expected< T >::takeError(), and llvm::BitCodeAbbrevOp::VBR.

Referenced by advance(), and ReadBlockInfoBlock().

◆ ReadBlockEnd()

bool llvm::BitstreamCursor::ReadBlockEnd ( ) inline

◆ ReadBlockInfoBlock()

Read and return a block info block from the bitstream.

If an error was encountered, return std::nullopt.

Parameters

ReadBlockInfoNames Whether to read block/record name information in the BlockInfo block. Only llvm-bcanalyzer uses this.

Definition at line 423 of file BitstreamReader.cpp.

References llvm::BitstreamBlockInfo::BlockInfo::Abbrevs, advanceSkippingSubblocks(), AF_DontAutoprocessAbbrevs, llvm::bitc::BLOCKINFO_BLOCK_ID, llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, llvm::bitc::BLOCKINFO_CODE_SETBID, llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, llvm::bitc::DEFINE_ABBREV, llvm::BitstreamEntry::EndBlock, EnterSubBlock(), llvm::BitstreamEntry::Error, llvm::Expected< T >::get(), llvm::BitstreamBlockInfo::getOrCreateBlockInfo(), llvm::BitstreamBlockInfo::BlockInfo::Name, ReadAbbrevRecord(), readRecord(), llvm::BitstreamEntry::Record, llvm::BitstreamBlockInfo::BlockInfo::RecordNames, llvm::BitstreamEntry::SubBlock, and llvm::Expected< T >::takeError().

Referenced by llvm::BitcodeAnalyzer::analyze().

◆ ReadCode()

◆ readRecord()

Definition at line 214 of file BitstreamReader.cpp.

References llvm::alignTo(), llvm::SmallVectorImpl< T >::append(), llvm::BitCodeAbbrevOp::Array, assert(), llvm::BitCodeAbbrevOp::Blob, canSkipToPos(), llvm::BitCodeAbbrevOp::Char6, llvm::BitCodeAbbrevOp::DecodeChar6(), error, llvm::BitCodeAbbrevOp::Fixed, llvm::Expected< T >::get(), getAbbrev(), GetCurrentBitNo(), llvm::BitCodeAbbrevOp::getEncoding(), llvm::BitCodeAbbrevOp::getEncodingData(), llvm::BitCodeAbbrevOp::getLiteralValue(), llvm::BitCodeAbbrev::getNumOperandInfos(), llvm::BitCodeAbbrev::getOperandInfo(), llvm::SimpleBitstreamCursor::getPointerToBit(), llvm::BitCodeAbbrevOp::isEncoding(), llvm::BitCodeAbbrevOp::isLiteral(), llvm::SimpleBitstreamCursor::isSizePlausible(), JumpToBit(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::Read, readAbbreviatedField(), ReadVBR(), ReadVBR64(), llvm::SmallVectorImpl< T >::reserve(), llvm::SmallVectorTemplateCommon< T, typename >::size(), llvm::SimpleBitstreamCursor::SkipToFourByteBoundary(), llvm::Expected< T >::takeError(), llvm::toString(), llvm::bitc::UNABBREV_RECORD, and llvm::BitCodeAbbrevOp::VBR.

Referenced by getEnableSplitLTOUnitAndUnifiedFlag(), hasObjCCategoryInModule(), readBlobInRecord(), ReadBlockInfoBlock(), readIdentificationBlock(), and readModuleTriple().

◆ ReadSubBlockID()

◆ ReadVBR()

◆ ReadVBR64()

◆ setBlockInfo()

◆ SizeInBytes()

size_t llvm::SimpleBitstreamCursor::SizeInBytes ( ) const inline

◆ SkipBlock()

Error llvm::BitstreamCursor::SkipBlock ( ) inline

Having read the ENTER_SUBBLOCK abbrevid and a BlockID, skip over the body of this block.

Definition at line 484 of file BitstreamReader.h.

References AtEndOfStream(), llvm::bitc::BlockSizeWidth, canSkipToPos(), llvm::bitc::CodeLenWidth, llvm::createStringError(), llvm::Expected< T >::get(), GetCurrentBitNo(), JumpToBit(), llvm::Read, ReadVBR(), llvm::SimpleBitstreamCursor::SkipToFourByteBoundary(), llvm::Error::success(), and llvm::Expected< T >::takeError().

Referenced by advanceSkippingSubblocks(), llvm::BitcodeAnalyzer::analyze(), llvm::getBitcodeFileContents(), llvm::BitcodeModule::getLTOInfo(), hasObjCCategory(), readBlobInRecord(), readIdentificationCode(), and readTriple().

◆ skipRecord()

Read the current record and discard it, returning the code for the record.

skipRecord - Read the current record and discard it.

Definition at line 96 of file BitstreamReader.cpp.

References llvm::alignTo(), llvm::BitCodeAbbrevOp::Array, assert(), llvm::BitCodeAbbrevOp::Blob, canSkipToPos(), llvm::BitCodeAbbrevOp::Char6, llvm::createStringError(), error, llvm::BitCodeAbbrevOp::Fixed, llvm::Expected< T >::get(), getAbbrev(), GetCurrentBitNo(), llvm::BitCodeAbbrevOp::getEncoding(), llvm::BitCodeAbbrevOp::getEncodingData(), llvm::BitCodeAbbrevOp::getLiteralValue(), llvm::BitCodeAbbrev::getNumOperandInfos(), llvm::BitCodeAbbrev::getOperandInfo(), llvm::BitCodeAbbrevOp::isLiteral(), JumpToBit(), MaxChunkSize, readAbbreviatedField(), ReadVBR(), ReadVBR64(), skipToEnd(), llvm::SimpleBitstreamCursor::SkipToFourByteBoundary(), llvm::Expected< T >::takeError(), llvm::bitc::UNABBREV_RECORD, and llvm::BitCodeAbbrevOp::VBR.

Referenced by llvm::getBitcodeFileContents(), llvm::BitcodeModule::getLTOInfo(), hasObjCCategory(), readIdentificationCode(), and readTriple().

◆ skipToEnd()

void llvm::SimpleBitstreamCursor::skipToEnd ( ) inline

◆ MaxChunkSize

const size_t llvm::BitstreamCursor::MaxChunkSize = 32 static

The documentation for this class was generated from the following files: