ImHex/plugins/libimhex/source/lang/builtin_functions.cpp

#include <hex/lang/evaluator.hpp>
#include <hex/api/content_registry.hpp>

namespace hex::lang {

    #define LITERAL_COMPARE(literal, cond) std::visit([&, this](auto &&literal) { return (cond) != 0; }, literal)

    void Evaluator::registerBuiltinFunctions() {
        /* findSequence */
        ContentRegistry::PatternLanguageFunctions::add("findSequence", ContentRegistry::PatternLanguageFunctions::MoreParametersThan | 1, [this](auto &console, auto params) {
            auto& occurrenceIndex = asType<ASTNodeIntegerLiteral>(params[0])->getValue();
            std::vector<u8> sequence;
            for (u32 i = 1; i < params.size(); i++) {
                sequence.push_back(std::visit([&](auto &&value) -> u8 {
                    if (value <= 0xFF)
                        return value;
                    else
                        console.abortEvaluation("sequence bytes need to fit into 1 byte");
                }, asType<ASTNodeIntegerLiteral>(params[i])->getValue()));
            }

            std::vector<u8> bytes(sequence.size(), 0x00);
            u32 occurrences = 0;
            for (u64 offset = 0; offset < this->m_provider->getSize() - sequence.size(); offset++) {
                this->m_provider->read(offset, bytes.data(), bytes.size());

                if (bytes == sequence) {
                    if (LITERAL_COMPARE(occurrenceIndex, occurrences < occurrenceIndex)) {
                        occurrences++;
                        continue;
                    }

                    return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned64Bit, offset });
                }
            }

            console.abortEvaluation("failed to find sequence");
        });

        /* assert */
        ContentRegistry::PatternLanguageFunctions::add("readUnsigned", 2, [this](auto &console, auto params) {
            auto address = asType<ASTNodeIntegerLiteral>(params[0])->getValue();
            auto size = asType<ASTNodeIntegerLiteral>(params[1])->getValue();

            if (LITERAL_COMPARE(address, address >= this->m_provider->getActualSize()))
                console.abortEvaluation("address out of range");

            return std::visit([&, this](auto &&address, auto &&size) {
                if (size <= 0 || size > 16)
                    console.abortEvaluation("invalid read size");

                u8 value[(u8)size];
                this->m_provider->read(address, value, size);

                switch ((u8)size) {
                    case 1:  return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned8Bit,   hex::changeEndianess(*reinterpret_cast<u8*>(value), 1, this->getCurrentEndian()) });
                    case 2:  return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned16Bit,  hex::changeEndianess(*reinterpret_cast<u16*>(value), 2, this->getCurrentEndian()) });
                    case 4:  return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned32Bit,  hex::changeEndianess(*reinterpret_cast<u32*>(value), 4, this->getCurrentEndian()) });
                    case 8:  return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned64Bit,  hex::changeEndianess(*reinterpret_cast<u64*>(value), 8, this->getCurrentEndian()) });
                    case 16: return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned128Bit, hex::changeEndianess(*reinterpret_cast<u128*>(value), 16, this->getCurrentEndian()) });
                    default: console.abortEvaluation("invalid read size");
                }
            }, address, size);
        });

        ContentRegistry::PatternLanguageFunctions::add("readSigned", 2, [this](auto &console, auto params) {
            auto address = asType<ASTNodeIntegerLiteral>(params[0])->getValue();
            auto size = asType<ASTNodeIntegerLiteral>(params[1])->getValue();

            if (LITERAL_COMPARE(address, address >= this->m_provider->getActualSize()))
                console.abortEvaluation("address out of range");

            return std::visit([&, this](auto &&address, auto &&size) {
                if (size <= 0 || size > 16)
                    console.abortEvaluation("invalid read size");

                u8 value[(u8)size];
                this->m_provider->read(address, value, size);

                switch ((u8)size) {
                    case 1:  return new ASTNodeIntegerLiteral({ Token::ValueType::Signed8Bit,   hex::changeEndianess(*reinterpret_cast<s8*>(value), 1, this->getCurrentEndian()) });
                    case 2:  return new ASTNodeIntegerLiteral({ Token::ValueType::Signed16Bit,  hex::changeEndianess(*reinterpret_cast<s16*>(value), 2, this->getCurrentEndian()) });
                    case 4:  return new ASTNodeIntegerLiteral({ Token::ValueType::Signed32Bit,  hex::changeEndianess(*reinterpret_cast<s32*>(value), 4, this->getCurrentEndian()) });
                    case 8:  return new ASTNodeIntegerLiteral({ Token::ValueType::Signed64Bit,  hex::changeEndianess(*reinterpret_cast<s64*>(value), 8, this->getCurrentEndian()) });
                    case 16: return new ASTNodeIntegerLiteral({ Token::ValueType::Signed128Bit, hex::changeEndianess(*reinterpret_cast<s128*>(value), 16, this->getCurrentEndian()) });
                    default: console.abortEvaluation("invalid read size");
                }
            }, address, size);
        });

        ContentRegistry::PatternLanguageFunctions::add("assert", 2, [this](auto &console, auto params) {
            auto condition = asType<ASTNodeIntegerLiteral>(params[0])->getValue();
            auto message = asType<ASTNodeStringLiteral>(params[1])->getString();

            if (LITERAL_COMPARE(condition, condition == 0))
                console.abortEvaluation(hex::format("assert failed \"%s\"", message.data()));

            return nullptr;
        });

        ContentRegistry::PatternLanguageFunctions::add("warnAssert", 2, [this](auto console, auto params) {
            auto condition = asType<ASTNodeIntegerLiteral>(params[0])->getValue();
            auto message = asType<ASTNodeStringLiteral>(params[1])->getString();

            if (LITERAL_COMPARE(condition, condition == 0))
                console.log(LogConsole::Level::Warning, hex::format("assert failed \"%s\"", message.data()));

            return nullptr;
        });

        ContentRegistry::PatternLanguageFunctions::add("print", ContentRegistry::PatternLanguageFunctions::MoreParametersThan | 0, [](auto &console, auto params) {
            std::string message;
            for (auto& param : params) {
                if (auto integerLiteral = dynamic_cast<ASTNodeIntegerLiteral*>(param); integerLiteral != nullptr) {
                    switch (integerLiteral->getType()) {
                        case Token::ValueType::Character:       message += std::get<s8>(integerLiteral->getValue()); break;
                        case Token::ValueType::Unsigned8Bit:    message += std::to_string(std::get<u8>(integerLiteral->getValue())); break;
                        case Token::ValueType::Signed8Bit:      message += std::to_string(std::get<s8>(integerLiteral->getValue())); break;
                        case Token::ValueType::Unsigned16Bit:   message += std::to_string(std::get<u16>(integerLiteral->getValue())); break;
                        case Token::ValueType::Signed16Bit:     message += std::to_string(std::get<s16>(integerLiteral->getValue())); break;
                        case Token::ValueType::Unsigned32Bit:   message += std::to_string(std::get<u32>(integerLiteral->getValue())); break;
                        case Token::ValueType::Signed32Bit:     message += std::to_string(std::get<s32>(integerLiteral->getValue())); break;
                        case Token::ValueType::Unsigned64Bit:   message += std::to_string(std::get<u64>(integerLiteral->getValue())); break;
                        case Token::ValueType::Signed64Bit:     message += std::to_string(std::get<s64>(integerLiteral->getValue())); break;
                        case Token::ValueType::Unsigned128Bit:  message += hex::to_string(std::get<u128>(integerLiteral->getValue())); break;
                        case Token::ValueType::Signed128Bit:    message += hex::to_string(std::get<s128>(integerLiteral->getValue())); break;
                        case Token::ValueType::Float:           message += std::to_string(std::get<float>(integerLiteral->getValue())); break;
                        case Token::ValueType::Double:          message += std::to_string(std::get<double>(integerLiteral->getValue())); break;
                        case Token::ValueType::Boolean:         message += std::get<s32>(integerLiteral->getValue()) ? "true" : "false"; break;
                        case Token::ValueType::CustomType:      message += "< Custom Type >"; break;
                    }
                }
                else if (auto stringLiteral = dynamic_cast<ASTNodeStringLiteral*>(param); stringLiteral != nullptr)
                    message += stringLiteral->getString();
            }

            console.log(LogConsole::Level::Info, message);

            return nullptr;
        });

        ContentRegistry::PatternLanguageFunctions::add("addressof", 1, [this](auto &console, auto params) -> ASTNode* {
            auto name = asType<ASTNodeStringLiteral>(params[0])->getString();

            std::vector<std::string> path = splitString(name, ".");
            auto pattern = this->patternFromName(path);

            return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned64Bit, u64(pattern->getOffset()) });
        });

        ContentRegistry::PatternLanguageFunctions::add("sizeof", 1, [this](auto &console, auto params) -> ASTNode* {
            auto name = asType<ASTNodeStringLiteral>(params[0])->getString();

            std::vector<std::string> path = splitString(name, ".");
            auto pattern = this->patternFromName(path);

            return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned64Bit, u64(pattern->getSize()) });
        });

        ContentRegistry::PatternLanguageFunctions::add("nextAfter", 1, [this](auto &console, auto params) -> ASTNode* {
            auto name = asType<ASTNodeStringLiteral>(params[0])->getString();

            std::vector<std::string> path = splitString(name, ".");
            auto pattern = this->patternFromName(path);

            return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned64Bit, u64(pattern->getOffset() + pattern->getSize()) });
        });

        ContentRegistry::PatternLanguageFunctions::add("alignTo", 2, [this](auto &console, auto params) -> ASTNode* {
            auto alignment = asType<ASTNodeIntegerLiteral>(params[0])->getValue();
            auto value = asType<ASTNodeIntegerLiteral>(params[1])->getValue();

            auto result = std::visit([](auto &&alignment, auto &&value) {
                u64 remainder = u64(value) % u64(alignment);
                return remainder != 0 ? u64(value) + (u64(alignment) - remainder) : u64(value);
            }, alignment, value);

            return new ASTNodeIntegerLiteral({ Token::ValueType::Unsigned64Bit, u64(result) });
        });
    }

}