mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-04-14 05:20:30 +00:00
91 lines
3.5 KiB
C++
91 lines
3.5 KiB
C++
//=== FileOutputBuffer.h - File Output Buffer -------------------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Utility for creating a in-memory buffer that will be written to a file.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SUPPORT_FILEOUTPUTBUFFER_H
|
|
#define LLVM_SUPPORT_FILEOUTPUTBUFFER_H
|
|
|
|
#include "llvm/ADT/SmallString.h"
|
|
#include "llvm/ADT/StringRef.h"
|
|
#include "llvm/Support/DataTypes.h"
|
|
#include "llvm/Support/Error.h"
|
|
#include "llvm/Support/FileSystem.h"
|
|
|
|
namespace llvm {
|
|
/// FileOutputBuffer - This interface provides simple way to create an in-memory
|
|
/// buffer which will be written to a file. During the lifetime of these
|
|
/// objects, the content or existence of the specified file is undefined. That
|
|
/// is, creating an OutputBuffer for a file may immediately remove the file.
|
|
/// If the FileOutputBuffer is committed, the target file's content will become
|
|
/// the buffer content at the time of the commit. If the FileOutputBuffer is
|
|
/// not committed, the file will be deleted in the FileOutputBuffer destructor.
|
|
class FileOutputBuffer {
|
|
public:
|
|
enum {
|
|
/// set the 'x' bit on the resulting file
|
|
F_executable = 1,
|
|
|
|
/// the contents of the new file are initialized from the file that exists
|
|
/// at the location (if present). This allows in-place modification of an
|
|
/// existing file.
|
|
F_modify = 2
|
|
};
|
|
|
|
/// Factory method to create an OutputBuffer object which manages a read/write
|
|
/// buffer of the specified size. When committed, the buffer will be written
|
|
/// to the file at the specified path.
|
|
///
|
|
/// When F_modify is specified and \p FilePath refers to an existing on-disk
|
|
/// file \p Size may be set to -1, in which case the entire file is used.
|
|
/// Otherwise, the file shrinks or grows as necessary based on the value of
|
|
/// \p Size. It is an error to specify F_modify and Size=-1 if \p FilePath
|
|
/// does not exist.
|
|
static Expected<std::unique_ptr<FileOutputBuffer>>
|
|
create(StringRef FilePath, size_t Size, unsigned Flags = 0);
|
|
|
|
/// Returns a pointer to the start of the buffer.
|
|
virtual uint8_t *getBufferStart() const = 0;
|
|
|
|
/// Returns a pointer to the end of the buffer.
|
|
virtual uint8_t *getBufferEnd() const = 0;
|
|
|
|
/// Returns size of the buffer.
|
|
virtual size_t getBufferSize() const = 0;
|
|
|
|
/// Returns path where file will show up if buffer is committed.
|
|
StringRef getPath() const { return FinalPath; }
|
|
|
|
/// Flushes the content of the buffer to its file and deallocates the
|
|
/// buffer. If commit() is not called before this object's destructor
|
|
/// is called, the file is deleted in the destructor. The optional parameter
|
|
/// is used if it turns out you want the file size to be smaller than
|
|
/// initially requested.
|
|
virtual Error commit() = 0;
|
|
|
|
/// If this object was previously committed, the destructor just deletes
|
|
/// this object. If this object was not committed, the destructor
|
|
/// deallocates the buffer and the target file is never written.
|
|
virtual ~FileOutputBuffer() {}
|
|
|
|
/// This removes the temporary file (unless it already was committed)
|
|
/// but keeps the memory mapping alive.
|
|
virtual void discard() {}
|
|
|
|
protected:
|
|
FileOutputBuffer(StringRef Path) : FinalPath(Path) {}
|
|
|
|
std::string FinalPath;
|
|
};
|
|
} // end namespace llvm
|
|
|
|
#endif
|