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Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions
llvm::MemoryBuffer Class Reference

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 <MemoryBuffer.h>

Inheritance diagram for llvm::MemoryBuffer:
Inheritance graph
[legend]

List of all members.

Public Types

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

Public Member Functions

virtual ~MemoryBuffer ()
const char * getBufferStart () const
const char * getBufferEnd () const
size_t getBufferSize () const
StringRef getBuffer () const
virtual const char * getBufferIdentifier () const
 Return an identifier for this buffer, typically the filename it was read from.
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, int64_t FileSize=-1, bool RequiresNullTerminator=true, bool IsVolatileSize=false)
 Open the specified file as a MemoryBuffer, returning a new MemoryBuffer if successful, otherwise returning null.
static ErrorOr
< std::unique_ptr
< MemoryBuffer > > 
getOpenFileSlice (int FD, const Twine &Filename, uint64_t MapSize, int64_t Offset)
 Given an already-open file descriptor, map some slice of it into a MemoryBuffer.
static ErrorOr
< std::unique_ptr
< MemoryBuffer > > 
getOpenFile (int FD, const Twine &Filename, uint64_t FileSize, bool RequiresNullTerminator=true, bool IsVolatileSize=false)
 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 std::unique_ptr
< MemoryBuffer
getNewMemBuffer (size_t Size, StringRef BufferName="")
 Allocate a new zero-initialized MemoryBuffer of the specified size.
static std::unique_ptr
< MemoryBuffer
getNewUninitMemBuffer (size_t Size, const Twine &BufferName="")
 Allocate a new MemoryBuffer of the specified size that is not initialized.
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, int64_t FileSize=-1)
 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)
 Map a subrange of the the specified file as a MemoryBuffer.

Protected Member Functions

 MemoryBuffer ()
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 37 of file MemoryBuffer.h.


Member Enumeration Documentation

The kind of memory backing used to support the MemoryBuffer.

Enumerator:
MemoryBuffer_Malloc 
MemoryBuffer_MMap 

Definition at line 136 of file MemoryBuffer.h.


Constructor & Destructor Documentation

llvm::MemoryBuffer::MemoryBuffer ( ) [inline, protected]

Definition at line 44 of file MemoryBuffer.h.

Definition at line 41 of file MemoryBuffer.cpp.


Member Function Documentation

const char* llvm::MemoryBuffer::getBufferEnd ( ) const [inline]
virtual const char* llvm::MemoryBuffer::getBufferIdentifier ( ) const [inline, virtual]

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

Reimplemented in llvm::ObjectMemoryBuffer, and llvm::ObjectMemoryBuffer.

Definition at line 60 of file MemoryBuffer.h.

Referenced by getMemBufferRef(), and llvm::SourceMgr::GetMessage().

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.

size_t llvm::MemoryBuffer::getBufferSize ( ) const [inline]
const char* llvm::MemoryBuffer::getBufferStart ( ) const [inline]
ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFile ( const Twine Filename,
int64_t  FileSize = -1,
bool  RequiresNullTerminator = true,
bool  IsVolatileSize = 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:
IsVolatileSizeSet to true to indicate that the file size may be changing, e.g. when libclang tries to parse while the user is editing/updating the file.

Definition at line 246 of file MemoryBuffer.cpp.

References getFileAux().

Referenced by llvm::SourceMgr::AddIncludeFile(), llvm::LTOCodeGenerator::compileOptimized(), llvm::SpecialCaseList::create(), llvm::LTOModule::createFromFile(), llvm::object::ObjectFile::createObjectFile(), llvm::DiffFilesWithTolerance(), ExpandResponseFile(), getFileOrSTDIN(), llvm::LTOModule::isBitcodeFile(), LLVMCreateMemoryBufferWithContentsOfFile(), and llvm::SymbolRewriter::RewriteMapParser::parse().

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFileOrSTDIN ( const Twine Filename,
int64_t  FileSize = -1 
) [static]
ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getFileSlice ( const Twine Filename,
uint64_t  MapSize,
uint64_t  Offset 
) [static]

Map a subrange of the the specified file as a MemoryBuffer.

Definition at line 174 of file MemoryBuffer.cpp.

References getFileAux().

std::unique_ptr< MemoryBuffer > MemoryBuffer::getMemBuffer ( StringRef  InputData,
StringRef  BufferName = "",
bool  RequiresNullTerminator = true 
) [static]
std::unique_ptr< MemoryBuffer > MemoryBuffer::getMemBuffer ( MemoryBufferRef  Ref,
bool  RequiresNullTerminator = true 
) [static]
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 118 of file MemoryBuffer.cpp.

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

Referenced by getMemoryBufferForStream(), LLVMCreateMemoryBufferWithMemoryRangeCopy(), LLVMWriteBitcodeToMemoryBuffer(), and llvm::InstrProfWriter::writeBuffer().

Definition at line 431 of file MemoryBuffer.cpp.

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

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

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 155 of file MemoryBuffer.cpp.

References 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 129 of file MemoryBuffer.cpp.

References CopyStringRef(), operator new(), llvm::MipsISD::Ret, llvm::RoundUpToAlignment(), llvm::StringRef::size(), and llvm::Twine::toStringRef().

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

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

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

Parameters:
IsVolatileSizeSet to true to indicate that the file size may be changing, e.g. when libclang tries to parse while the user is editing/updating the file.

Definition at line 407 of file MemoryBuffer.cpp.

References getOpenFileImpl().

ErrorOr< std::unique_ptr< MemoryBuffer > > MemoryBuffer::getOpenFileSlice ( int  FD,
const Twine Filename,
uint64_t  MapSize,
int64_t  Offset 
) [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 414 of file MemoryBuffer.cpp.

References getOpenFileImpl().

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

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

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

Definition at line 421 of file MemoryBuffer.cpp.

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

Referenced by getFileOrSTDIN(), and LLVMCreateMemoryBufferWithSTDIN().

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.

Referenced by llvm::ObjectMemoryBuffer::ObjectMemoryBuffer().


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