This interface provides simple read-only access to a block of memory, and provides simple methods for reading files and standard input into a memory buffer. More...

#include "llvm/Support/MemoryBuffer.h"

Inheritance diagram for llvm::MemoryBuffer:

[legend]

Public Types
enum	BufferKind { MemoryBuffer_Malloc , MemoryBuffer_MMap }
	The kind of memory backing used to support the MemoryBuffer. More...

Public Member Functions
	MemoryBuffer (const MemoryBuffer &)=delete

MemoryBuffer &	operator= (const MemoryBuffer &)=delete

virtual	~MemoryBuffer ()

const char *	getBufferStart () const

const char *	getBufferEnd () const

size_t	getBufferSize () const

StringRef	getBuffer () const

virtual StringRef	getBufferIdentifier () const
	Return an identifier for this buffer, typically the filename it was read from.

virtual void	dontNeedIfMmap ()
	For read-only MemoryBuffer_MMap, mark the buffer as unused in the near future and the kernel can free resources associated with it.

virtual BufferKind	getBufferKind () const =0
	Return information on the memory mechanism used to support the MemoryBuffer.

MemoryBufferRef	getMemBufferRef () const

Static Public Member Functions
static ErrorOr< std::unique_ptr< MemoryBuffer > >	getFile (const Twine &Filename, bool IsText=false, bool RequiresNullTerminator=true, bool IsVolatile=false, std::optional< Align > Alignment=std::nullopt)
	Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful, otherwise returning null.

static ErrorOr< std::unique_ptr< MemoryBuffer > >	getFileAsStream (const Twine &Filename)
	Read all of the specified file into a MemoryBuffer as a stream (i.e.

static ErrorOr< std::unique_ptr< MemoryBuffer > >	getOpenFileSlice (sys::fs::file_t FD, const Twine &Filename, uint64_t MapSize, int64_t Offset, bool IsVolatile=false, std::optional< Align > Alignment=std::nullopt)
	Given an already-open file descriptor, map some slice of it into a MemoryBuffer.

static ErrorOr< std::unique_ptr< MemoryBuffer > >	getOpenFile (sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize, bool RequiresNullTerminator=true, bool IsVolatile=false, std::optional< Align > Alignment=std::nullopt)
	Given an already-open file descriptor, read the file and return a MemoryBuffer.

static std::unique_ptr< MemoryBuffer >	getMemBuffer (StringRef InputData, StringRef BufferName="", bool RequiresNullTerminator=true)
	Open the specified memory range as a MemoryBuffer.

static std::unique_ptr< MemoryBuffer >	getMemBuffer (MemoryBufferRef Ref, bool RequiresNullTerminator=true)

static std::unique_ptr< MemoryBuffer >	getMemBufferCopy (StringRef InputData, const Twine &BufferName="")
	Open the specified memory range as a MemoryBuffer, copying the contents and taking ownership of it.

static ErrorOr< std::unique_ptr< MemoryBuffer > >	getSTDIN ()
	Read all of stdin into a file buffer, and return it.

static ErrorOr< std::unique_ptr< MemoryBuffer > >	getFileOrSTDIN (const Twine &Filename, bool IsText=false, bool RequiresNullTerminator=true, std::optional< Align > Alignment=std::nullopt)
	Open the specified file as a MemoryBuffer, or open stdin if the Filename is "-".

static ErrorOr< std::unique_ptr< MemoryBuffer > >	getFileSlice (const Twine &Filename, uint64_t MapSize, uint64_t Offset, bool IsVolatile=false, std::optional< Align > Alignment=std::nullopt)
	Map a subrange of the specified file as a MemoryBuffer.

Protected Member Functions
	MemoryBuffer ()=default

void	init (const char BufStart, const char BufEnd, bool RequiresNullTerminator)
	init - Initialize this MemoryBuffer as a reference to externally allocated memory, memory that we know is already null terminated.

Detailed Description

This interface provides simple read-only access to a block of memory, and provides simple methods for reading files and standard input into a memory buffer.

In addition to basic access to the characters in the file, this interface guarantees you can read one character past the end of the file, and that this character will read as '\0'.

The '\0' guarantee is needed to support an optimization – it's intended to be more efficient for clients which are reading all the data to stop reading when they encounter a '\0' than to continually check the file position to see if it has reached the end of the file.

Definition at line 51 of file MemoryBuffer.h.

Member Enumeration Documentation

◆ BufferKind

enum llvm::MemoryBuffer::BufferKind

The kind of memory backing used to support the MemoryBuffer.

Enumerator
MemoryBuffer_Malloc
MemoryBuffer_MMap

Definition at line 165 of file MemoryBuffer.h.

Constructor & Destructor Documentation

◆ MemoryBuffer() [1/2]

llvm::MemoryBuffer::MemoryBuffer ( )

protecteddefault

◆ MemoryBuffer() [2/2]

llvm::MemoryBuffer::MemoryBuffer ( const MemoryBuffer & )

delete

◆ ~MemoryBuffer()

MemoryBuffer::~MemoryBuffer ( )

virtualdefault

Member Function Documentation

◆ dontNeedIfMmap()

virtual void llvm::MemoryBuffer::dontNeedIfMmap ( )

inlinevirtual

For read-only MemoryBuffer_MMap, mark the buffer as unused in the near future and the kernel can free resources associated with it.

Further access is supported but may be expensive. This calls madvise(MADV_DONTNEED) on read-only file mappings on *NIX systems. This function should not be called on a writable buffer.

Definition at line 83 of file MemoryBuffer.h.

◆ getBuffer()

StringRef llvm::MemoryBuffer::getBuffer ( ) const

inline

Definition at line 70 of file MemoryBuffer.h.

References getBufferSize().

Referenced by getMemBufferRef(), GetOrCreateOffsetCache(), llvm::TextCodeGenDataReader::hasFormat(), llvm::SpecialCaseList::parse(), llvm::GCOVBuffer::readGCDAFormat(), llvm::GCOVBuffer::readGCNOFormat(), llvm::streamFile(), llvm::TGLexer::TGLexer(), and llvm::ThinLTOCodeGenerator::writeGeneratedObject().

◆ getBufferEnd()

const char * llvm::MemoryBuffer::getBufferEnd ( ) const

inline

Definition at line 67 of file MemoryBuffer.h.

Referenced by llvm::FileCheck::CanonicalizeFile(), llvm::RuntimeDyldCheckerImpl::checkAllRulesInBuffer(), llvm::DiffFilesWithTolerance(), llvm::WritableMemoryBuffer::getBufferEnd(), llvm::WriteThroughMemoryBuffer::getBufferEnd(), llvm::SourceMgr::GetMessage(), llvm::CodeGenCoverage::parse(), and readBinaryIdsInternal().

◆ getBufferIdentifier()

virtual StringRef llvm::MemoryBuffer::getBufferIdentifier ( ) const

inlinevirtual

Return an identifier for this buffer, typically the filename it was read from.

Reimplemented in llvm::SmallVectorMemoryBuffer.

Definition at line 76 of file MemoryBuffer.h.

Referenced by llvm::sampleprof::SampleProfileReaderItaniumRemapper::applyRemapping(), llvm::pdb::InputFile::getFilePath(), getMemBufferRef(), llvm::SourceMgr::GetMessage(), llvm::SIMachineFunctionInfo::initializeBaseYamlFields(), llvm::MCContext::MCContext(), llvm::orc::objDesc(), and llvm::GCNTargetMachine::parseMachineFunctionInfo().

◆ getBufferKind()

virtual BufferKind llvm::MemoryBuffer::getBufferKind ( ) const

pure virtual

Return information on the memory mechanism used to support the MemoryBuffer.

Implemented in llvm::SmallVectorMemoryBuffer.

◆ getBufferSize()

size_t llvm::MemoryBuffer::getBufferSize ( ) const

inline

Definition at line 68 of file MemoryBuffer.h.

Referenced by llvm::FileCheck::CanonicalizeFile(), llvm::DiffFilesWithTolerance(), getBuffer(), GetOrCreateOffsetCache(), llvm::IndexedCodeGenDataReader::hasFormat(), llvm::TextInstrProfReader::hasFormat(), llvm::RawInstrProfReader< IntPtrT >::hasFormat(), llvm::IndexedInstrProfReader::hasFormat(), llvm::memprof::RawMemProfReader::hasFormat(), and llvm::streamFile().

◆ getBufferStart()

const char * llvm::MemoryBuffer::getBufferStart ( ) const

inline

Definition at line 66 of file MemoryBuffer.h.

Referenced by llvm::FileCheck::CanonicalizeFile(), llvm::RuntimeDyldCheckerImpl::checkAllRulesInBuffer(), llvm::DiffFilesWithTolerance(), llvm::WritableMemoryBuffer::getBufferStart(), llvm::WriteThroughMemoryBuffer::getBufferStart(), llvm::SourceMgr::GetMessage(), llvm::IndexedCodeGenDataReader::hasFormat(), llvm::TextInstrProfReader::hasFormat(), llvm::RawInstrProfReader< IntPtrT >::hasFormat(), llvm::IndexedInstrProfReader::hasFormat(), llvm::memprof::RawMemProfReader::hasFormat(), llvm::CodeGenCoverage::parse(), and llvm::memprof::RawMemProfReader::peekBuildIds().

◆ getFile()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFile	(	const Twine &	Filename,
		bool	IsText = `false`,
		bool	RequiresNullTerminator = `true`,
		bool	IsVolatile = `false`,
		std::optional< Align >	Alignment = `std::nullopt`
	)

static

Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful, otherwise returning null.

Parameters

IsText	Set to true to indicate that the file should be read in text mode.
IsVolatile	Set to true to indicate that the contents of the file can change outside the user's control, e.g. when libclang tries to parse while the user is editing/updating the file or if the file is on an NFS.
Alignment	Set to indicate that the buffer should be aligned to at least the specified alignment.

Definition at line 261 of file MemoryBuffer.cpp.

Referenced by llvm::MachO::DylibReader::accumulateSourceLocFromDSYM(), llvm::LTOCodeGenerator::compileOptimized(), llvm::computeLTOCacheKey(), llvm::orc::COFFPlatform::Create(), llvm::LTOModule::createFromFile(), llvm::objcopy::coff::createGnuDebugLinkSectionContents(), llvm::object::ObjectFile::createObjectFile(), llvm::remarks::createYAMLParserFromMeta(), llvm::DiffFilesWithTolerance(), doList(), llvm::doSystemDiff(), llvm::findVCToolChainViaSetupConfig(), llvm::InstrProfCorrelator::get(), llvm::codegen::getBBSectionsMode(), llvm::object::Archive::Child::getBuffer(), getFileOrSTDIN(), llvm::getHeaders(), llvm::unittest::getInputFileDirectory(), llvm::identify_magic(), llvm::LTOModule::isBitcodeFile(), llvm::libDriverMain(), LLVMCreateMemoryBufferWithContentsOfFile(), llvm::orc::loadMachORelocatableObject(), llvm::OpenMPIRBuilder::loadOffloadInfoMetadata(), loadPdbFile(), llvm::orc::loadRelocatableObject(), llvm::MemProfContextDisambiguation::MemProfContextDisambiguation(), llvm::pdb::InputFile::open(), openFile(), llvm::SourceMgr::OpenIncludeFile(), llvm::orc::ExecutorNativePlatform::operator()(), llvm::SymbolRewriter::RewriteMapParser::parse(), parseCHRFilterFiles(), printSymbolizedStackTrace(), llvm::CtxProfAnalysis::run(), llvm::runFuzzerOnInputs(), llvm::TableGenMain(), llvm::lto::thinBackend(), and llvm::ifs::writeELFBinaryToFile().

◆ getFileAsStream()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFileAsStream ( const Twine & Filename )

static

Read all of the specified file into a MemoryBuffer as a stream (i.e.

until EOF reached). This is useful for special files that look like a regular file but have 0 size (e.g. /proc/cpuinfo on Linux).

Definition at line 566 of file MemoryBuffer.cpp.

References llvm::sys::fs::closeFile(), llvm::errorToErrorCode(), getMemoryBufferForStream(), llvm::sys::fs::OF_None, llvm::sys::fs::openNativeFileForRead(), and llvm::Expected< T >::takeError().

Referenced by getProcCpuinfoContent().

◆ getFileOrSTDIN()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFileOrSTDIN	(	const Twine &	Filename,
		bool	IsText = `false`,
		bool	RequiresNullTerminator = `true`,
		std::optional< Align >	Alignment = `std::nullopt`
	)

static

Open the specified file as a MemoryBuffer, or open stdin if the Filename is "-".

Definition at line 164 of file MemoryBuffer.cpp.

References getFile(), and getSTDIN().

Referenced by llvm::memprof::RawMemProfReader::create(), llvm::object::createBinary(), llvm::createMIRParserFromFile(), llvm::getLazyIRFileModule(), llvm::getModuleSummaryIndexForFile(), llvm::memprof::RawMemProfReader::hasFormat(), llvm::gsym::GsymReader::openFile(), llvm::parseAssemblyFile(), parseAssemblyFileWithIndex(), llvm::parseIRFile(), llvm::parseSummaryIndexAssemblyFile(), llvm::ReplayInlineAdvisor::ReplayInlineAdvisor(), llvm::ForceFunctionAttrsPass::run(), searchForObj(), and llvm::TableGenMain().

◆ getFileSlice()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFileSlice	(	const Twine &	Filename,
		uint64_t	MapSize,
		uint64_t	Offset,
		bool	IsVolatile = `false`,
		std::optional< Align >	Alignment = `std::nullopt`
	)

static

Map a subrange of the specified file as a MemoryBuffer.

Definition at line 177 of file MemoryBuffer.cpp.

References llvm::Offset.

Referenced by llvm::orc::StaticLibraryDefinitionGenerator::Load(), and llvm::orc::loadMachORelocatableObjectFromUniversalBinary().

◆ getMemBuffer() [1/2]

std::unique_ptr< MemoryBuffer > MemoryBuffer::getMemBuffer	(	MemoryBufferRef	Ref,
		bool	RequiresNullTerminator = `true`
	)

static

Definition at line 138 of file MemoryBuffer.cpp.

References getMemBuffer(), and llvm::Ref.

◆ getMemBuffer() [2/2]

std::unique_ptr< MemoryBuffer > MemoryBuffer::getMemBuffer	(	StringRef	InputData,
		StringRef	BufferName = `""`,
		bool	RequiresNullTerminator = `true`
	)

static

Open the specified memory range as a MemoryBuffer.

Note that InputData must be null terminated if RequiresNullTerminator is true.

Definition at line 130 of file MemoryBuffer.cpp.

Referenced by llvm::vfs::InMemoryFileSystem::addFileNoOwn(), getMemBuffer(), llvm::NewArchiveMember::getOldMember(), llvm::MIRParserImpl::initializeMachineFunction(), initializeRecordStreamer(), LLVMBinaryCopyMemoryBuffer(), LLVMCreateMemoryBufferWithMemoryRange(), loadBinaryFormat(), loadTestingFormat(), llvm::LTOModule::makeBuffer(), parseAssemblyInto(), llvm::parseConstantValue(), llvm::parseDIExpressionBodyAtBeginning(), llvm::parseModule(), parseSummaryIndexAssemblyInto(), llvm::parseType(), llvm::parseTypeAtBeginning(), llvm::ForceFunctionAttrsPass::run(), llvm::orc::COFFPlatform::setupJITDylib(), and llvm::orc::StaticLibraryDefinitionGenerator::tryToGenerate().

◆ getMemBufferCopy()

std::unique_ptr< MemoryBuffer > MemoryBuffer::getMemBufferCopy	(	StringRef	InputData,
		const Twine &	BufferName = `""`
	)

static

Open the specified memory range as a MemoryBuffer, copying the contents and taking ownership of it.

InputData does not have to be null terminated.

Definition at line 156 of file MemoryBuffer.cpp.

References getMemBufferCopyImpl().

Referenced by llvm::object::OffloadFile::copy(), llvm::gsym::GsymReader::copyBuffer(), llvm::FileCheckPatternContext::defineCmdlineVariables(), emitDebugSectionImpl(), llvm::objcopy::wasm::handleArgs(), LLVMCreateMemoryBufferWithMemoryRangeCopy(), LLVMWriteBitcodeToMemoryBuffer(), llvm::localCache(), llvm::FileCheck::readCheckFile(), llvm::InstrProfWriter::writeBuffer(), and llvm::yaml::yaml2offload().

◆ getMemBufferRef()

MemoryBufferRef MemoryBuffer::getMemBufferRef ( ) const

Definition at line 578 of file MemoryBuffer.cpp.

References llvm::Data, getBuffer(), and getBufferIdentifier().

Referenced by llvm::LTOModule::getProducerString(), and llvm::LTOModule::isBitcodeForTarget().

◆ getOpenFile()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getOpenFile	(	sys::fs::file_t	FD,
		const Twine &	Filename,
		uint64_t	FileSize,
		bool	RequiresNullTerminator = `true`,
		bool	IsVolatile = `false`,
		std::optional< Align >	Alignment = `std::nullopt`
	)

static

Given an already-open file descriptor, read the file and return a MemoryBuffer.

Parameters

IsVolatile	Set to true to indicate that the contents of the file can change outside the user's control, e.g. when libclang tries to parse while the user is editing/updating the file or if the file is on an NFS.
Alignment	Set to indicate that the buffer should be aligned to at least the specified alignment.

Definition at line 539 of file MemoryBuffer.cpp.

Referenced by llvm::NewArchiveMember::getFile(), llvm::localCache(), and llvm::streamFile().

◆ getOpenFileSlice()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getOpenFileSlice	(	sys::fs::file_t	FD,
		const Twine &	Filename,
		uint64_t	MapSize,
		int64_t	Offset,
		bool	IsVolatile = `false`,
		std::optional< Align >	Alignment = `std::nullopt`
	)

static

Given an already-open file descriptor, map some slice of it into a MemoryBuffer.

The slice is specified by an Offset and MapSize. Since this is in the middle of a file, the buffer is not null terminated.

Definition at line 547 of file MemoryBuffer.cpp.

References assert(), and llvm::Offset.

Referenced by llvm::LTOModule::createFromOpenFileSlice().

◆ getSTDIN()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getSTDIN ( )

static

Read all of stdin into a file buffer, and return it.

Definition at line 555 of file MemoryBuffer.cpp.

References llvm::sys::ChangeStdinMode(), getMemoryBufferForStream(), llvm::sys::fs::getStdinHandle(), and llvm::sys::fs::OF_Text.

Referenced by getFileOrSTDIN(), LLVMCreateMemoryBufferWithSTDIN(), llvm::setupMemoryBuffer(), and setupMemoryBuffer().

◆ init()

void MemoryBuffer::init	(	const char *	BufStart,
		const char *	BufEnd,
		bool	RequiresNullTerminator
	)

protected

init - Initialize this MemoryBuffer as a reference to externally allocated memory, memory that we know is already null terminated.

Definition at line 51 of file MemoryBuffer.cpp.

References assert().

Referenced by llvm::SmallVectorMemoryBuffer::SmallVectorMemoryBuffer().

◆ operator=()

MemoryBuffer & llvm::MemoryBuffer::operator= ( const MemoryBuffer & )

delete

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

include/llvm/Support/MemoryBuffer.h
lib/Support/MemoryBuffer.cpp

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ BufferKind

Constructor & Destructor Documentation

◆ MemoryBuffer() [1/2]

◆ MemoryBuffer() [2/2]

◆ ~MemoryBuffer()

Member Function Documentation

◆ dontNeedIfMmap()

◆ getBuffer()

◆ getBufferEnd()

◆ getBufferIdentifier()

◆ getBufferKind()

◆ getBufferSize()

◆ getBufferStart()

◆ getFile()

◆ getFileAsStream()

◆ getFileOrSTDIN()

◆ getFileSlice()

◆ getMemBuffer() [1/2]

◆ getMemBuffer() [2/2]

◆ getMemBufferCopy()

◆ getMemBufferRef()

◆ getOpenFile()

◆ getOpenFileSlice()

◆ getSTDIN()

◆ init()

◆ operator=()