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

#include "llvm/Bitstream/BitstreamReader.h"

Inheritance diagram for llvm::BitstreamCursor:

Collaboration diagram for llvm::BitstreamCursor:

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.

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.

Expected< unsigned >	skipRecord (unsigned AbbrevID)
	Read the current record and discard it, returning the code for the record.

Expected< unsigned >	readRecord (unsigned AbbrevID, SmallVectorImpl< uint64_t > &Vals, StringRef *Blob=nullptr)

Error	ReadAbbrevRecord ()

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

Detailed Description

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.

Member Enumeration Documentation

◆ anonymous enum

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.

Constructor & Destructor Documentation

◆ BitstreamCursor() [1/4]

llvm::BitstreamCursor::BitstreamCursor ( )

default

◆ BitstreamCursor() [2/4]

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

inlineexplicit

Definition at line 382 of file BitstreamReader.h.

◆ BitstreamCursor() [3/4]

llvm::BitstreamCursor::BitstreamCursor ( StringRef BitcodeBytes )

inlineexplicit

Definition at line 384 of file BitstreamReader.h.

◆ BitstreamCursor() [4/4]

llvm::BitstreamCursor::BitstreamCursor ( MemoryBufferRef BitcodeBytes )

inlineexplicit

Definition at line 386 of file BitstreamReader.h.

Member Function Documentation

◆ advance()

Expected< BitstreamEntry > llvm::BitstreamCursor::advance ( unsigned Flags = 0 )

inline

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(), llvm::getBitcodeFileContents(), llvm::BitcodeModule::getLTOInfo(), hasObjCCategory(), isBlock(), jumpToValueSymbolTable(), parseBlock(), llvm::remarks::BitstreamParserHelper::parseBlockInfoBlock(), readBlobInRecord(), readIdentificationBlock(), readIdentificationCode(), and readTriple().

◆ advanceSkippingSubblocks()

Expected< BitstreamEntry > llvm::BitstreamCursor::advanceSkippingSubblocks ( unsigned Flags = 0 )

inline

This is a convenience function for clients that don't expect any subblocks.

This just skips over them automatically.

Definition at line 457 of file BitstreamReader.h.

References advance(), llvm::Expected< T >::get(), SkipBlock(), and llvm::BitstreamEntry::SubBlock.

Referenced by getEnableSplitLTOUnitFlag(), hasObjCCategoryInModule(), ReadBlockInfoBlock(), and readModuleTriple().

◆ AtEndOfStream()

bool llvm::SimpleBitstreamCursor::AtEndOfStream ( )

inline

Definition at line 112 of file BitstreamReader.h.

Referenced by advance(), llvm::BitcodeAnalyzer::analyze(), llvm::remarks::BitstreamParserHelper::atEndOfStream(), EnterSubBlock(), parseBlock(), readIdentificationCode(), and SkipBlock().

◆ canSkipToPos()

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

inline

Definition at line 107 of file BitstreamReader.h.

Referenced by hasInvalidBitcodeHeader(), readRecord(), SkipBlock(), and skipRecord().

◆ EnterSubBlock()

Error BitstreamCursor::EnterSubBlock	(	unsigned	BlockID,
		unsigned *	NumWordsP = `nullptr`
	)

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::SmallVectorTemplateCommon< T, typename >::back(), llvm::bitc::BlockSizeWidth, llvm::bitc::CodeLenWidth, llvm::createStringError(), llvm::Expected< T >::get(), llvm::BitstreamBlockInfo::getBlockInfo(), Info, MaxChunkSize, llvm::SmallVectorTemplateBase< T, bool >::push_back(), Read(), ReadVBR(), llvm::SimpleBitstreamCursor::SkipToFourByteBoundary(), llvm::Error::success(), and llvm::Expected< T >::takeError().

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

◆ fillCurWord()

Error llvm::SimpleBitstreamCursor::fillCurWord ( )

inline

Definition at line 160 of file BitstreamReader.h.

◆ getAbbrev()

Expected< const BitCodeAbbrev * > llvm::BitstreamCursor::getAbbrev ( unsigned AbbrevID )

inline

Return the abbreviation for the specified AbbrevId.

Definition at line 543 of file BitstreamReader.h.

References llvm::createStringError(), and llvm::bitc::FIRST_APPLICATION_ABBREV.

Referenced by readRecord(), and skipRecord().

◆ 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

Definition at line 124 of file BitstreamReader.h.

Referenced by analyzeHeader(), llvm::getBitcodeFileContents(), and llvm::BitcodeAnalyzer::printStats().

◆ GetCurrentBitNo()

uint64_t llvm::SimpleBitstreamCursor::GetCurrentBitNo ( ) const

inline

Return the bit # of the bit we are reading.

Definition at line 117 of file BitstreamReader.h.

Referenced by llvm::getBitcodeFileContents(), isBlock(), jumpToValueSymbolTable(), readRecord(), SkipBlock(), and skipRecord().

◆ getCurrentByteNo()

uint64_t llvm::SimpleBitstreamCursor::getCurrentByteNo ( ) const

inline

Definition at line 122 of file BitstreamReader.h.

Referenced by llvm::getBitcodeFileContents().

◆ getPointerToByte()

const uint8_t * llvm::SimpleBitstreamCursor::getPointerToByte	(	uint64_t	ByteNo,
		uint64_t	NumBytes
	)

inline

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

Definition at line 148 of file BitstreamReader.h.

◆ JumpToBit()

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

inline

Reset the stream to the specified bit number.

Definition at line 127 of file BitstreamReader.h.

Referenced by llvm::BitcodeModule::getLTOInfo(), llvm::BitcodeModule::getSummary(), isBlock(), jumpToValueSymbolTable(), readRecord(), llvm::BitcodeModule::readSummary(), SkipBlock(), and skipRecord().

◆ Read()

Expected< word_t > llvm::SimpleBitstreamCursor::Read ( unsigned NumBits )

inline

Definition at line 186 of file BitstreamReader.h.

Referenced by EnterSubBlock(), hasInvalidBitcodeHeader(), llvm::remarks::BitstreamParserHelper::parseMagic(), readAbbreviatedField(), ReadAbbrevRecord(), ReadCode(), readRecord(), ReadSignature(), and SkipBlock().

◆ ReadAbbrevRecord()

Error BitstreamCursor::ReadAbbrevRecord ( )

Definition at line 363 of file BitstreamReader.cpp.

References llvm::Data, E, error, llvm::BitCodeAbbrevOp::Fixed, llvm::Expected< T >::get(), llvm::BitCodeAbbrevOp::hasEncodingData(), llvm::BitCodeAbbrevOp::isValidEncoding(), MaxChunkSize, 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

Definition at line 518 of file BitstreamReader.h.

References llvm::SmallVectorBase< Size_T >::empty(), and llvm::SimpleBitstreamCursor::SkipToFourByteBoundary().

Referenced by advance().

◆ ReadBlockInfoBlock()

Expected< std::optional< BitstreamBlockInfo > > BitstreamCursor::ReadBlockInfoBlock ( bool ReadBlockInfoNames = false )

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 422 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(), and llvm::remarks::BitstreamParserHelper::parseBlockInfoBlock().

◆ ReadCode()

Expected< unsigned > llvm::BitstreamCursor::ReadCode ( )

inline

Definition at line 474 of file BitstreamReader.h.

References Read().

Referenced by advance(), and llvm::BitcodeAnalyzer::analyze().

◆ readRecord()

Expected< unsigned > BitstreamCursor::readRecord	(	unsigned	AbbrevID,
		SmallVectorImpl< uint64_t > &	Vals,
		StringRef *	Blob = `nullptr`
	)

Definition at line 214 of file BitstreamReader.cpp.

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

◆ ReadSubBlockID()

Expected< unsigned > llvm::BitstreamCursor::ReadSubBlockID ( )

inline

Having read the ENTER_SUBBLOCK code, read the BlockID for the block.

Definition at line 480 of file BitstreamReader.h.

References llvm::bitc::BlockIDWidth, and ReadVBR().

Referenced by advance(), and llvm::BitcodeAnalyzer::analyze().

◆ ReadVBR()

Expected< uint32_t > llvm::SimpleBitstreamCursor::ReadVBR ( const unsigned NumBits )

inline

Definition at line 229 of file BitstreamReader.h.

Referenced by EnterSubBlock(), ReadAbbrevRecord(), readRecord(), ReadSubBlockID(), SkipBlock(), and skipRecord().

◆ ReadVBR64()

Expected< uint64_t > llvm::SimpleBitstreamCursor::ReadVBR64 ( const unsigned NumBits )

inline

Definition at line 264 of file BitstreamReader.h.

Referenced by readAbbreviatedField(), ReadAbbrevRecord(), readRecord(), and skipRecord().

◆ setBlockInfo()

void llvm::BitstreamCursor::setBlockInfo ( BitstreamBlockInfo * BI )

inline

Set the block info to be used by this BitstreamCursor to interpret abbreviated records.

Definition at line 573 of file BitstreamReader.h.

Referenced by llvm::BitcodeAnalyzer::analyze(), and llvm::remarks::BitstreamParserHelper::parseBlockInfoBlock().

◆ SizeInBytes()

size_t llvm::SimpleBitstreamCursor::SizeInBytes ( ) const

inline

Return the size of the stream in bytes.

Definition at line 310 of file BitstreamReader.h.

◆ 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(), 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()

Expected< unsigned > BitstreamCursor::skipRecord ( unsigned AbbrevID )

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.

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

◆ skipToEnd()

void llvm::SimpleBitstreamCursor::skipToEnd ( )

inline

Skip to the end of the file.

Definition at line 313 of file BitstreamReader.h.

Referenced by skipRecord(), and llvm::remarks::BitstreamParserHelper::skipToEnd().

Member Data Documentation

◆ MaxChunkSize

const size_t llvm::BitstreamCursor::MaxChunkSize = 32

static

Definition at line 379 of file BitstreamReader.h.

Referenced by EnterSubBlock(), readAbbreviatedField(), ReadAbbrevRecord(), and skipRecord().

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

include/llvm/Bitstream/BitstreamReader.h
lib/Bitstream/Reader/BitstreamReader.cpp

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ BitstreamCursor() [1/4]

◆ BitstreamCursor() [2/4]

◆ BitstreamCursor() [3/4]

◆ BitstreamCursor() [4/4]

Member Function Documentation

◆ advance()

◆ advanceSkippingSubblocks()

◆ AtEndOfStream()

◆ canSkipToPos()

◆ EnterSubBlock()

◆ fillCurWord()

◆ getAbbrev()

◆ getAbbrevIDWidth()

◆ getBitcodeBytes()

◆ GetCurrentBitNo()

◆ getCurrentByteNo()

◆ getPointerToByte()

◆ JumpToBit()

◆ Read()

◆ ReadAbbrevRecord()

◆ ReadBlockEnd()

◆ ReadBlockInfoBlock()

◆ ReadCode()

◆ readRecord()

◆ ReadSubBlockID()

◆ ReadVBR()

◆ ReadVBR64()

◆ setBlockInfo()

◆ SizeInBytes()

◆ SkipBlock()

◆ skipRecord()

◆ skipToEnd()

Member Data Documentation

◆ MaxChunkSize