chromium/components/zucchini/reloc_win32.h

// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_ZUCCHINI_RELOC_WIN32_H_
#define COMPONENTS_ZUCCHINI_RELOC_WIN32_H_

#include <stddef.h>
#include <stdint.h>

#include <optional>
#include <vector>

#include "base/memory/raw_ref.h"
#include "components/zucchini/address_translator.h"
#include "components/zucchini/buffer_source.h"
#include "components/zucchini/buffer_view.h"
#include "components/zucchini/image_utils.h"

namespace zucchini {

// Win32 PE relocation table stores a list of (type, RVA) pairs. The table is
// organized into "blocks" for RVAs with common high-order bits (12-31). Each
// block consists of a list (even length) of 2-byte "units". Each unit stores
// type (in bits 12-15) and low-order bits (0-11) of an RVA (in bits 0-11). In
// pseudo-struct:
//   struct Block {
//     uint32_t rva_hi;
//     uint32_t block_size_in_bytes;  // 8 + multiple of 4.
//     struct {
//       uint16_t rva_lo:12, type:4;  // Little-endian.
//     } units[(block_size_in_bytes - 8) / 2];  // Size must be even.
//   } reloc_table[num_blocks];  // May have padding (type = 0).

// Extracted Win32 reloc Unit data.
struct RelocUnitWin32 { … };

// A reader that parses Win32 PE relocation data and emits RelocUnitWin32 for
// each reloc unit that lies strictly inside |[lo, hi)|.
class RelocRvaReaderWin32 { … };

// A reader for Win32 reloc References, implemented as a filtering and
// translation adaptor of RelocRvaReaderWin32.
class RelocReaderWin32 : public ReferenceReader { … };

// A writer for Win32 reloc References. This is simpler than the reader since:
// - No iteration is required.
// - High-order bits of reloc target RVAs are assumed to be handled elsewhere,
//   so only low-order bits need to be written.
class RelocWriterWin32 : public ReferenceWriter { … };

}  // namespace zucchini

#endif  // COMPONENTS_ZUCCHINI_RELOC_WIN32_H_