LLVM  6.0.0svn
Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
llvm::MemoryBuffer Class Referenceabstract

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:
Inheritance graph
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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
 
MemoryBufferoperator= (const MemoryBuffer &)=delete
 
virtual ~MemoryBuffer ()
 
const chargetBufferStart () const
 
const chargetBufferEnd () 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. More...
 
virtual BufferKind getBufferKind () const =0
 Return information on the memory mechanism used to support the MemoryBuffer. More...
 
MemoryBufferRef getMemBufferRef () const
 

Static Public Member Functions

static ErrorOr< std::unique_ptr< MemoryBuffer > > getFile (const Twine &Filename, int64_t FileSize=-1, bool RequiresNullTerminator=true, bool IsVolatile=false)
 Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful, otherwise returning null. More...
 
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFileAsStream (const Twine &Filename)
 Read all of the specified file into a MemoryBuffer as a stream (i.e. More...
 
static ErrorOr< std::unique_ptr< MemoryBuffer > > getOpenFileSlice (int FD, const Twine &Filename, uint64_t MapSize, int64_t Offset, bool IsVolatile=false)
 Given an already-open file descriptor, map some slice of it into a MemoryBuffer. More...
 
static ErrorOr< std::unique_ptr< MemoryBuffer > > getOpenFile (int FD, const Twine &Filename, uint64_t FileSize, bool RequiresNullTerminator=true, bool IsVolatile=false)
 Given an already-open file descriptor, read the file and return a MemoryBuffer. More...
 
static std::unique_ptr< MemoryBuffergetMemBuffer (StringRef InputData, StringRef BufferName="", bool RequiresNullTerminator=true)
 Open the specified memory range as a MemoryBuffer. More...
 
static std::unique_ptr< MemoryBuffergetMemBuffer (MemoryBufferRef Ref, bool RequiresNullTerminator=true)
 
static std::unique_ptr< MemoryBuffergetMemBufferCopy (StringRef InputData, const Twine &BufferName="")
 Open the specified memory range as a MemoryBuffer, copying the contents and taking ownership of it. More...
 
static std::unique_ptr< MemoryBuffergetNewMemBuffer (size_t Size, StringRef BufferName="")
 Allocate a new zero-initialized MemoryBuffer of the specified size. More...
 
static std::unique_ptr< MemoryBuffergetNewUninitMemBuffer (size_t Size, const Twine &BufferName="")
 Allocate a new MemoryBuffer of the specified size that is not initialized. More...
 
static ErrorOr< std::unique_ptr< MemoryBuffer > > getSTDIN ()
 Read all of stdin into a file buffer, and return it. More...
 
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFileOrSTDIN (const Twine &Filename, int64_t FileSize=-1, bool RequiresNullTerminator=true)
 Open the specified file as a MemoryBuffer, or open stdin if the Filename is "-". More...
 
static ErrorOr< std::unique_ptr< MemoryBuffer > > getFileSlice (const Twine &Filename, uint64_t MapSize, uint64_t Offset, bool IsVolatile=false)
 Map a subrange of the specified file as a MemoryBuffer. More...
 

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. More...
 

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 40 of file MemoryBuffer.h.

Member Enumeration Documentation

◆ BufferKind

The kind of memory backing used to support the MemoryBuffer.

Enumerator
MemoryBuffer_Malloc 
MemoryBuffer_MMap 

Definition at line 146 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 ( )
virtual

Definition at line 41 of file MemoryBuffer.cpp.

Member Function Documentation

◆ getBuffer()

StringRef llvm::MemoryBuffer::getBuffer ( ) const
inline

◆ getBufferEnd()

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

◆ getBufferIdentifier()

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

◆ getBufferKind()

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

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

Implemented in llvm::ObjectMemoryBuffer, and llvm::ObjectMemoryBuffer.

Referenced by getFileSlice().

◆ getBufferSize()

size_t llvm::MemoryBuffer::getBufferSize ( ) const
inline

◆ getBufferStart()

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

◆ getFile()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFile ( const Twine Filename,
int64_t  FileSize = -1,
bool  RequiresNullTerminator = true,
bool  IsVolatile = false 
)
static

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

If FileSize is specified, this means that the client knows that the file exists and that it has the specified size.

Parameters
IsVolatileSet 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.

Definition at line 254 of file MemoryBuffer.cpp.

References getFileAux(), and getOpenFileImpl().

Referenced by llvm::SourceMgr::AddIncludeFile(), llvm::LTOCodeGenerator::compileOptimized(), computeCacheKey(), llvm::SpecialCaseList::create(), llvm::LTOModule::createFromFile(), llvm::object::ObjectFile::createObjectFile(), llvm::DiffFilesWithTolerance(), ExpandResponseFile(), llvm::object::Archive::Child::getBuffer(), getBufferIdentifier(), getFileOrSTDIN(), llvm::LTOModule::isBitcodeFile(), LLVMCreateMemoryBufferWithContentsOfFile(), llvm::lto::localCache(), openFile(), llvm::SymbolRewriter::RewriteMapParser::parse(), printSymbolizedStackTrace(), and llvm::WholeProgramDevirtPass::run().

◆ 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 437 of file MemoryBuffer.cpp.

References getMemoryBufferForStream(), llvm::sys::fs::openFileForRead(), and llvm::MipsISD::Ret.

Referenced by getBufferIdentifier(), llvm::sys::getHostCPUName(), and getProcCpuinfoContent().

◆ getFileOrSTDIN()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFileOrSTDIN ( const Twine Filename,
int64_t  FileSize = -1,
bool  RequiresNullTerminator = true 
)
static

◆ getFileSlice()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFileSlice ( const Twine Filename,
uint64_t  MapSize,
uint64_t  Offset,
bool  IsVolatile = false 
)
static

◆ getMemBuffer() [1/2]

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

◆ getMemBuffer() [2/2]

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

◆ 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 123 of file MemoryBuffer.cpp.

References llvm::StringRef::data(), getNewUninitMemBuffer(), and llvm::StringRef::size().

Referenced by EmitDebugSectionImpl(), getBits(), getBufferIdentifier(), getMemoryBufferForStream(), isOperator(), isValidEncoding(), LLVMCreateMemoryBufferWithMemoryRangeCopy(), LLVMWriteBitcodeToMemoryBuffer(), srcMgrDiagHandler(), and llvm::InstrProfWriter::writeBuffer().

◆ getMemBufferRef()

MemoryBufferRef MemoryBuffer::getMemBufferRef ( ) const

◆ getNewMemBuffer()

std::unique_ptr< MemoryBuffer > MemoryBuffer::getNewMemBuffer ( size_t  Size,
StringRef  BufferName = "" 
)
static

Allocate a new zero-initialized MemoryBuffer of the specified size.

Note that the caller need not initialize the memory allocated by this method. The memory is owned by the MemoryBuffer object.

Definition at line 160 of file MemoryBuffer.cpp.

References getNewUninitMemBuffer().

Referenced by getBufferIdentifier(), and llvm::object::WindowsResourceCOFFWriter::WindowsResourceCOFFWriter().

◆ getNewUninitMemBuffer()

std::unique_ptr< MemoryBuffer > MemoryBuffer::getNewUninitMemBuffer ( size_t  Size,
const Twine BufferName = "" 
)
static

Allocate a new MemoryBuffer of the specified size that is not initialized.

Note that the caller should initialize the memory allocated by this method. The memory is owned by the MemoryBuffer object.

Definition at line 134 of file MemoryBuffer.cpp.

References llvm::alignTo(), CopyStringRef(), llvm::MipsISD::Ret, llvm::StringRef::size(), llvm::AMDGPU::CodeObject::Kernel::Arg::Key::Size, and llvm::Twine::toStringRef().

Referenced by getBufferIdentifier(), getMemBufferCopy(), getNewMemBuffer(), and getOpenFileImpl().

◆ getOpenFile()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getOpenFile ( int  FD,
const Twine Filename,
uint64_t  FileSize,
bool  RequiresNullTerminator = true,
bool  IsVolatile = false 
)
static

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

Parameters
IsVolatileSet 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.

Definition at line 413 of file MemoryBuffer.cpp.

References getOpenFileImpl().

Referenced by getBufferIdentifier(), and llvm::NewArchiveMember::getFile().

◆ getOpenFileSlice()

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getOpenFileSlice ( int  FD,
const Twine Filename,
uint64_t  MapSize,
int64_t  Offset,
bool  IsVolatile = false 
)
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 420 of file MemoryBuffer.cpp.

References assert(), and getOpenFileImpl().

Referenced by llvm::LTOModule::createFromOpenFileSlice(), and getBufferIdentifier().

◆ getSTDIN()

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

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

Definition at line 426 of file MemoryBuffer.cpp.

References llvm::sys::ChangeStdinToBinary(), and getMemoryBufferForStream().

Referenced by getBufferIdentifier(), getFileOrSTDIN(), and LLVMCreateMemoryBufferWithSTDIN().

◆ 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 45 of file MemoryBuffer.cpp.

References assert().

Referenced by getFileSlice(), and llvm::ObjectMemoryBuffer::ObjectMemoryBuffer().

◆ operator=()

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

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