91 lines
4.0 KiB
C++
91 lines
4.0 KiB
C++
#include "DecoderLengthCases.hpp"
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#include <codegen/CodegenException.hpp>
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#include <codegen/x86/X64InstructionDecoder.hpp>
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#include <cstdint>
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#include <iostream>
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#include <stdexcept>
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#include <string>
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#include <string_view>
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#include <utility>
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#include <vector>
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namespace {
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using Bytes = std::vector<std::uint8_t>;
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void require(bool condition, const std::string& message) {
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if (!condition) throw std::runtime_error(message);
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}
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Bytes parse(std::string_view hex) {
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Bytes bytes;
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for (std::size_t index = 0; index + 1 < hex.size(); index += 2) {
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bytes.push_back(static_cast<std::uint8_t>(std::stoul(std::string(hex.substr(index, 2)), nullptr, 16)));
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}
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return bytes;
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}
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std::size_t decodedLength(const Codegen::X64InstructionDecoder& decoder, const Bytes& bytes, const std::string& name) {
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try {
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return decoder.Decode(bytes.data(), bytes.size());
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} catch (const Codegen::CodegenException& error) {
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throw std::runtime_error("Cannot decode " + name + ": " + error.what());
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}
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}
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bool truncationRejected(const Codegen::X64InstructionDecoder& decoder, const Bytes& bytes, std::size_t available) {
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try {
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(void)decoder.Decode(bytes.data(), available);
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} catch (const Codegen::CodegenException&) {
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return true;
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}
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return false;
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}
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}
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int main() {
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try {
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const Codegen::X64InstructionDecoder decoder;
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for (const auto& testCase : kDecoderLengthCases) {
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const std::string name = testCase.Bytes;
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auto bytes = parse(testCase.Bytes);
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require(bytes.size() == testCase.Length, "Decoder length case " + name + " does not hold its own length");
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require(decodedLength(decoder, bytes, name) == testCase.Length, "Wrong length for " + name);
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require(truncationRejected(decoder, bytes, bytes.size() - 1), "A truncated " + name + " was accepted");
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bytes.insert(bytes.end(), 15, 0x90);
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require(decodedLength(decoder, bytes, name + " followed by NOPs") == testCase.Length, "Wrong length for " + name + " followed by NOPs");
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}
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for (const auto& testCase : std::vector<std::pair<std::size_t, Bytes>>{
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{14, {0x90}},
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{12, {0x68, 0x00, 0x00}},
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{8, {0x8b, 0x84, 0x25, 0x00, 0x00, 0x00, 0x00}}
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}) {
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Bytes longest(testCase.first, 0x66);
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longest.insert(longest.end(), testCase.second.begin(), testCase.second.end());
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require(longest.size() == 15, "Maximum-length instruction fixture is not 15 bytes");
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require(decoder.Decode(longest.data(), longest.size()) == 15, "Valid 15-byte instruction was rejected");
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require(decoder.DecodeInstruction(longest.data(), longest.size()).Length == 15, "Valid 15-byte instruction metadata was rejected");
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Bytes withTrailingNops = longest;
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withTrailingNops.insert(withTrailingNops.end(), 15, 0x90);
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require(decoder.Decode(withTrailingNops.data(), withTrailingNops.size()) == 15, "Valid maximum-length instruction consumed trailing bytes");
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longest.insert(longest.begin(), 0x66);
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require(truncationRejected(decoder, longest, longest.size()), "Instruction longer than 15 bytes was accepted");
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try {
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(void)decoder.DecodeInstruction(longest.data(), longest.size());
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throw std::runtime_error("Instruction metadata accepted a length above 15 bytes");
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} catch (const Codegen::CodegenException&) {
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}
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}
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const auto threeDNow = parse("0f0f0d11223344a6");
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const auto threeDNowInfo = decoder.DecodeInstruction(threeDNow.data(), threeDNow.size());
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require(threeDNowInfo.HasModRm && threeDNowInfo.ModRmByte == 0x0d, "3DNow! ModRM was not reported");
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require(threeDNowInfo.HasRipRelativeDisp && threeDNowInfo.RipRelativeDispOffset == 3, "3DNow! RIP-relative displacement was not reported");
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std::cout << "Decoder length tests passed\n";
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} catch (const std::exception& error) {
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std::cerr << error.what() << '\n';
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return 1;
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}
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return 0;
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}
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