llvm/llvm/include/llvm/Support/MemoryBuffer.h

//===--- MemoryBuffer.h - Memory Buffer Interface ---------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//  This file defines the MemoryBuffer interface.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_MEMORYBUFFER_H
#define LLVM_SUPPORT_MEMORYBUFFER_H

#include "llvm-c/Types.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/CBindingWrapping.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MemoryBufferRef.h"
#include <cstddef>
#include <cstdint>
#include <memory>

namespace llvm {
namespace sys {
namespace fs {
// Duplicated from FileSystem.h to avoid a dependency.
#if defined(_WIN32)
// A Win32 HANDLE is a typedef of void*
using file_t = void *;
#else
file_t;
#endif
} // namespace fs
} // namespace sys

/// 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.
class MemoryBuffer { … };

/// This class is an extension of MemoryBuffer, which allows copy-on-write
/// access to the underlying contents.  It only supports creation methods that
/// are guaranteed to produce a writable buffer.  For example, mapping a file
/// read-only is not supported.
class WritableMemoryBuffer : public MemoryBuffer { … };

/// This class is an extension of MemoryBuffer, which allows write access to
/// the underlying contents and committing those changes to the original source.
/// It only supports creation methods that are guaranteed to produce a writable
/// buffer.  For example, mapping a file read-only is not supported.
class WriteThroughMemoryBuffer : public MemoryBuffer { … };

// Create wrappers for C Binding types (see CBindingWrapping.h).
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(…)

} // end namespace llvm

#endif // LLVM_SUPPORT_MEMORYBUFFER_H