/* Copyright 2017 - 2025 R. Thomas

* Copyright 2017 - 2025 Quarkslab

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

#include <utility>

#include <climits>

#include "LIEF/OAT/Class.hpp"

#include "LIEF/OAT/hash.hpp"

#include "LIEF/OAT/EnumToString.hpp"

#include "LIEF/DEX/Method.hpp"

#include "LIEF/DEX/Class.hpp"

#include "logging.hpp"

#if defined(_MSC_VER)

# include <intrin.h>

# define __builtin_popcount __popcnt

#endif

namespace LIEF {

namespace OAT {

Class::Class(const Class&) = default;

Class& Class::operator=(const Class&) = default;

Class::Class() = default;

Class::Class(OAT_CLASS_STATUS status, OAT_CLASS_TYPES type,

DEX::Class* dex_class, std::vector<uint32_t> bitmap) :

dex_class_{dex_class},

status_{status},

type_{type},

method_bitmap_{std::move(bitmap)}

{}

bool Class::has_dex_class() const {

return dex_class_ != nullptr;

}

const DEX::Class* Class::dex_class() const {

return dex_class_;

}

DEX::Class* Class::dex_class() {

return const_cast<DEX::Class*>(static_cast<const Class*>(this)->dex_class());

}

OAT_CLASS_STATUS Class::status() const {

return status_;

}

OAT_CLASS_TYPES Class::type() const {

return type_;

}

Class::it_methods Class::methods() {

return methods_;

}

Class::it_const_methods Class::methods() const {

return methods_;

}

DEX::dex2dex_class_info_t Class::dex2dex_info() const {

if (const DEX::Class* cls = dex_class()) {

return cls->dex2dex_info();

}

return {};

}

const std::string& Class::fullname() const {

return dex_class()->fullname();

}

size_t Class::index() const {

if (has_dex_class()) {

return dex_class()->index();

}

return SIZE_MAX;

}

const std::vector<uint32_t>& Class::bitmap() const {

return method_bitmap_;

}

bool Class::is_quickened(const DEX::Method& m) const {

if (!has_dex_class()) {

return false;

}

const DEX::Class& cls = *dex_class();

if (m.bytecode().empty()) {

return false;

}

const auto& methods = cls.methods();

const auto it_method_index = std::find_if(std::begin(methods), std::end(methods),

[&m] (const DEX::Method& mth) {

return &m == &mth;

});

if (it_method_index == std::end(methods)) {

LIEF_ERR("Can't find '{}' in {}", m.name(), cls.fullname());

return false;

}

uint32_t relative_index = std::distance(std::begin(methods), it_method_index);

return is_quickened(relative_index);

}

bool Class::is_quickened(uint32_t relative_index) const {

if (type() == OAT_CLASS_TYPES::OAT_CLASS_NONE_COMPILED) {

return false;

}

if (type() == OAT_CLASS_TYPES::OAT_CLASS_ALL_COMPILED) {

return true;

}

if (type() == OAT_CLASS_TYPES::OAT_CLASS_SOME_COMPILED) {

const uint32_t bitmap_idx = relative_index >> 5;

const uint32_t bitmap_mask = 1 << (relative_index & 0x1F);

if (bitmap_idx > method_bitmap_.size()) {

LIEF_ERR("bitmap_idx: 0x{:x} is corrupted", bitmap_idx);

return false;

}

return (method_bitmap_[bitmap_idx] & bitmap_mask) != 0;

}

return false;

}

uint32_t Class::method_offsets_index(const DEX::Method& m) const {

if (!has_dex_class()) {

return UINT_MAX;

}

const DEX::Class& cls = *dex_class();

const auto& methods = cls.methods();

const auto it_method_index = std::find_if(std::begin(methods), std::end(methods),

[&m] (const DEX::Method& mth) {

return &m == &mth;

});

if (it_method_index == std::end(methods)) {

LIEF_ERR("Can't find '{}' in {}", m.name(), cls.fullname());

return UINT_MAX;

}

uint32_t relative_index = std::distance(std::begin(methods), it_method_index);

return method_offsets_index(relative_index);

}

uint32_t Class::method_offsets_index(uint32_t relative_index) const {

if (!is_quickened(relative_index) || type() == OAT_CLASS_TYPES::OAT_CLASS_NONE_COMPILED) {

return UINT_MAX;

}

if (type() == OAT_CLASS_TYPES::OAT_CLASS_ALL_COMPILED) {

return relative_index;

}

if (type() == OAT_CLASS_TYPES::OAT_CLASS_SOME_COMPILED) {

const uint32_t bitmap_end_idx = relative_index >> 5;

const uint32_t partial_word_bits = relative_index & 0x1f;

uint32_t count = 0;

for (uint32_t word = 0; word < bitmap_end_idx; ++word) {

count += __builtin_popcount(method_bitmap_[word]);

}

if (partial_word_bits != 0) {

count += __builtin_popcount(method_bitmap_[bitmap_end_idx] & ~(0xffffffffu << partial_word_bits));

}

return count;

}

return UINT_MAX;

}

uint32_t Class::relative_index(const DEX::Method& m) const {

if (!has_dex_class()) {

return UINT_MAX;

}

const DEX::Class& cls = *dex_class();

const auto& methods = cls.methods();

const auto it_method_index = std::find_if(std::begin(methods), std::end(methods),

[&m] (const DEX::Method& mth) {

return &m == &mth;

});

if (it_method_index == std::end(methods)) {

LIEF_ERR("Can't find '{}' in {}", m.name(), cls.fullname());

return UINT_MAX;

}

return std::distance(std::begin(methods), it_method_index);

}

uint32_t Class::relative_index(uint32_t method_absolute_index) const {

if (!has_dex_class()) {

return UINT_MAX;

}

const DEX::Class& cls = *dex_class();

const auto& methods = cls.methods();

const auto it_method_index = std::find_if(std::begin(methods), std::end(methods),

[method_absolute_index] (const DEX::Method& mth) {

return mth.index() == method_absolute_index;

});

if (it_method_index == std::end(methods)) {

LIEF_ERR("Can't find find method with index {:d} in {}", method_absolute_index, cls.fullname());

return UINT_MAX;

}

return std::distance(std::begin(methods), it_method_index);

}

void Class::accept(Visitor& visitor) const {

visitor.visit(*this);

}

std::ostream& operator<<(std::ostream& os, const Class& cls) {

os << cls.fullname() << " - "

<< to_string(cls.status()) << " - "

<< to_string(cls.type()) << " - "

<< std::dec << cls.methods().size() << " methods";

return os;

}

Class::~Class() = default;

}

}