/* This file is part of solidity. solidity is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. solidity is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with solidity. If not, see . */ // SPDX-License-Identifier: GPL-3.0 /** * @author Christian * @date 2014 * Tests for the Solidity optimizer. */ #include #include #include #include #include #include #include #include using namespace std; using namespace solidity::util; using namespace solidity::evmasm; using namespace solidity::test; namespace solidity::frontend::test { class OptimizerTestFramework: public SolidityExecutionFramework { public: bytes const& compileAndRunWithOptimizer( std::string const& _sourceCode, u256 const& _value = 0, std::string const& _contractName = "", bool const _optimize = true, unsigned const _optimizeRuns = 200 ) { OptimiserSettings previousSettings = std::move(m_optimiserSettings); // This uses "none" / "full" while most other test frameworks use // "minimal" / "standard". m_optimiserSettings = _optimize ? OptimiserSettings::full() : OptimiserSettings::none(); m_optimiserSettings.expectedExecutionsPerDeployment = _optimizeRuns; bytes const& ret = compileAndRun(_sourceCode, _value, _contractName); m_optimiserSettings = std::move(previousSettings); return ret; } /// Compiles the source code with and without optimizing. void compileBothVersions( std::string const& _sourceCode, u256 const& _value = 0, std::string const& _contractName = "", unsigned const _optimizeRuns = 200 ) { m_nonOptimizedBytecode = compileAndRunWithOptimizer("pragma solidity >=0.0;\n" + _sourceCode, _value, _contractName, false, _optimizeRuns); m_nonOptimizedContract = m_contractAddress; m_optimizedBytecode = compileAndRunWithOptimizer("pragma solidity >=0.0;\n" + _sourceCode, _value, _contractName, true, _optimizeRuns); size_t nonOptimizedSize = numInstructions(m_nonOptimizedBytecode); size_t optimizedSize = numInstructions(m_optimizedBytecode); BOOST_CHECK_MESSAGE( _optimizeRuns < 50 || optimizedSize < nonOptimizedSize, string("Optimizer did not reduce bytecode size. Non-optimized size: ") + to_string(nonOptimizedSize) + " - optimized size: " + to_string(optimizedSize) ); m_optimizedContract = m_contractAddress; } template void compareVersions(std::string _sig, Args const&... _arguments) { m_contractAddress = m_nonOptimizedContract; bytes nonOptimizedOutput = callContractFunction(_sig, _arguments...); m_gasUsedNonOptimized = m_gasUsed; m_contractAddress = m_optimizedContract; bytes optimizedOutput = callContractFunction(_sig, _arguments...); m_gasUsedOptimized = m_gasUsed; BOOST_CHECK_MESSAGE(!optimizedOutput.empty(), "No optimized output for " + _sig); BOOST_CHECK_MESSAGE(!nonOptimizedOutput.empty(), "No un-optimized output for " + _sig); BOOST_CHECK_MESSAGE(nonOptimizedOutput == optimizedOutput, "Computed values do not match." "\nNon-Optimized: " + toHex(nonOptimizedOutput) + "\nOptimized: " + toHex(optimizedOutput)); } /// @returns the number of instructions in the given bytecode, not taking the metadata hash /// into account. size_t numInstructions(bytes const& _bytecode, std::optional _which = std::optional{}) { bytes realCode = bytecodeSansMetadata(_bytecode); BOOST_REQUIRE_MESSAGE(!realCode.empty(), "Invalid or missing metadata in bytecode."); size_t instructions = 0; evmasm::eachInstruction(realCode, [&](Instruction _instr, u256 const&) { if (!_which || *_which == _instr) instructions++; }); return instructions; } protected: u256 m_gasUsedOptimized; u256 m_gasUsedNonOptimized; bytes m_nonOptimizedBytecode; bytes m_optimizedBytecode; h160 m_optimizedContract; h160 m_nonOptimizedContract; }; BOOST_FIXTURE_TEST_SUITE(SolidityOptimizer, OptimizerTestFramework) BOOST_AUTO_TEST_CASE(smoke_test) { char const* sourceCode = R"( contract test { function f(uint a) public returns (uint b) { return a; } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256)", u256(7)); } BOOST_AUTO_TEST_CASE(identities) { char const* sourceCode = R"( contract test { function f(int a) public returns (int b) { return int(0) | (int(1) * (int(0) ^ (0 + a))); } } )"; compileBothVersions(sourceCode); compareVersions("f(int256)", u256(0x12334664)); } BOOST_AUTO_TEST_CASE(unused_expressions) { char const* sourceCode = R"( contract test { uint data; function f() public returns (uint a, uint b) { 10 + 20; data; } } )"; compileBothVersions(sourceCode); compareVersions("f()"); } BOOST_AUTO_TEST_CASE(constant_folding_both_sides) { // if constants involving the same associative and commutative operator are applied from both // sides, the operator should be applied only once, because the expression compiler pushes // literals as late as possible char const* sourceCode = R"( contract test { function f(uint x) public returns (uint y) { return 98 ^ (7 * ((1 | (x | 1000)) * 40) ^ 102); } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256)", 7); } BOOST_AUTO_TEST_CASE(storage_access) { char const* sourceCode = R"( contract test { uint8[40] data; function f(uint x) public returns (uint y) { data[2] = data[7] = uint8(x); data[4] = data[2] * 10 + data[3]; } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256)", 7); } BOOST_AUTO_TEST_CASE(array_copy) { char const* sourceCode = R"( contract test { bytes2[] data1; bytes5[] data2; function f(uint x) public returns (uint l, uint y) { for (uint i = 0; i < msg.data.length; i++) data1.push(); for (uint i = 0; i < msg.data.length; ++i) data1[i] = msg.data[i]; data2 = data1; l = data2.length; y = uint(uint40(data2[x])); } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256)", 0); compareVersions("f(uint256)", 10); compareVersions("f(uint256)", 35); } BOOST_AUTO_TEST_CASE(function_calls) { char const* sourceCode = R"( contract test { function f1(uint x) public returns (uint) { unchecked { return x*x; } } function f(uint x) public returns (uint) { unchecked { return f1(7+x) - this.f1(x**9); } } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256)", 0); compareVersions("f(uint256)", 10); compareVersions("f(uint256)", 36); } BOOST_AUTO_TEST_CASE(storage_write_in_loops) { char const* sourceCode = R"( contract test { uint d; function f(uint a) public returns (uint r) { uint x = d; for (uint i = 1; i < a * a; i++) { r = d; d = i; } } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256)", 0); compareVersions("f(uint256)", 10); compareVersions("f(uint256)", 36); } // Test disabled with https://github.com/ethereum/solidity/pull/762 // Information in joining branches is not retained anymore. BOOST_AUTO_TEST_CASE(retain_information_in_branches) { // This tests that the optimizer knows that we already have "z == keccak256(abi.encodePacked(y))" inside both branches. char const* sourceCode = R"( contract c { bytes32 d; uint a; function f(uint x, bytes32 y) public returns (uint r_a, bytes32 r_d) { bytes32 z = keccak256(abi.encodePacked(y)); if (x > 8) { z = keccak256(abi.encodePacked(y)); a = x; } else { z = keccak256(abi.encodePacked(y)); a = x; } r_a = a; r_d = d; } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256,bytes32)", 0, "abc"); compareVersions("f(uint256,bytes32)", 8, "def"); compareVersions("f(uint256,bytes32)", 10, "ghi"); bytes optimizedBytecode = compileAndRunWithOptimizer(sourceCode, 0, "c", true); size_t numSHA3s = 0; eachInstruction(optimizedBytecode, [&](Instruction _instr, u256 const&) { if (_instr == Instruction::KECCAK256) numSHA3s++; }); // TEST DISABLED - OPTIMIZER IS NOT EFFECTIVE ON THIS ONE ANYMORE // BOOST_CHECK_EQUAL(1, numSHA3s); } BOOST_AUTO_TEST_CASE(store_tags_as_unions) { // This calls the same function from two sources and both calls have a certain Keccak-256 on // the stack at the same position. // Without storing tags as unions, the return from the shared function would not know where to // jump and thus all jumpdests are forced to clear their state and we do not know about the // sha3 anymore. // Note that, for now, this only works if the functions have the same number of return // parameters since otherwise, the return jump addresses are at different stack positions // which triggers the "unknown jump target" situation. char const* sourceCode = R"( contract test { bytes32 data; function f(uint x, bytes32 y) external returns (uint r_a, bytes32 r_d) { r_d = keccak256(abi.encodePacked(y)); shared(y); r_d = keccak256(abi.encodePacked(y)); r_a = 5; } function g(uint x, bytes32 y) external returns (uint r_a, bytes32 r_d) { r_d = keccak256(abi.encodePacked(y)); shared(y); r_d = bytes32(uint(keccak256(abi.encodePacked(y))) + 2); r_a = 7; } function shared(bytes32 y) internal { data = keccak256(abi.encodePacked(y)); } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256,bytes32)", 7, "abc"); bytes optimizedBytecode = compileAndRunWithOptimizer(sourceCode, 0, "test", true); size_t numSHA3s = 0; eachInstruction(optimizedBytecode, [&](Instruction _instr, u256 const&) { if (_instr == Instruction::KECCAK256) numSHA3s++; }); // TEST DISABLED UNTIL 93693404 IS IMPLEMENTED // BOOST_CHECK_EQUAL(2, numSHA3s); } BOOST_AUTO_TEST_CASE(incorrect_storage_access_bug) { // This bug appeared because a Keccak-256 operation with too low sequence number was used, // resulting in memory not being rewritten before the Keccak-256. The fix was to // take the max of the min sequence numbers when merging the states. char const* sourceCode = R"( contract C { mapping(uint => uint) data; function f() public returns (uint) { if (data[block.timestamp] == 0) data[type(uint).max - 6] = 5; return data[block.timestamp]; } } )"; compileBothVersions(sourceCode); compareVersions("f()"); } BOOST_AUTO_TEST_CASE(sequence_number_for_calls) { // This is a test for a bug that was present because we did not increment the sequence // number for CALLs - CALLs can read and write from memory (and DELEGATECALLs can do the same // to storage), so the sequence number should be incremented. char const* sourceCode = R"( contract test { function f(string memory a, string memory b) public returns (bool) { return sha256(bytes(a)) == sha256(bytes(b)); } } )"; compileBothVersions(sourceCode); compareVersions("f(string,string)", 0x40, 0x80, 3, "abc", 3, "def"); } BOOST_AUTO_TEST_CASE(computing_constants) { char const* sourceCode = R"( contract C { uint m_a; uint m_b; uint m_c; uint m_d; constructor() { set(); } function set() public returns (uint) { m_a = 0x77abc0000000000000000000000000000000000000000000000000000000001; m_b = 0x817416927846239487123469187231298734162934871263941234127518276; g(); return 1; } function g() public { m_b = 0x817416927846239487123469187231298734162934871263941234127518276; m_c = 0x817416927846239487123469187231298734162934871263941234127518276; h(); } function h() public { m_d = 0xff05694900000000000000000000000000000000000000000000000000000000; } function get() public returns (uint ra, uint rb, uint rc, uint rd) { ra = m_a; rb = m_b; rc = m_c; rd = m_d; } } )"; compileBothVersions(sourceCode, 0, "C", 1); compareVersions("get()"); compareVersions("set()"); compareVersions("get()"); bytes optimizedBytecode = compileAndRunWithOptimizer(sourceCode, 0, "C", true, 1); bytes complicatedConstant = toBigEndian(u256("0x817416927846239487123469187231298734162934871263941234127518276")); unsigned occurrences = 0; for (auto iter = optimizedBytecode.cbegin(); iter < optimizedBytecode.cend(); ++occurrences) { iter = search(iter, optimizedBytecode.cend(), complicatedConstant.cbegin(), complicatedConstant.cend()); if (iter < optimizedBytecode.cend()) ++iter; } BOOST_CHECK_EQUAL(2, occurrences); bytes constantWithZeros = toBigEndian(u256("0x77abc0000000000000000000000000000000000000000000000000000000001")); BOOST_CHECK(search( optimizedBytecode.cbegin(), optimizedBytecode.cend(), constantWithZeros.cbegin(), constantWithZeros.cend() ) == optimizedBytecode.cend()); } BOOST_AUTO_TEST_CASE(constant_optimization_early_exit) { // This tests that the constant optimizer does not try to find the best representation // indefinitely but instead stops after some number of iterations. char const* sourceCode = R"( contract HexEncoding { function hexEncodeTest(address addr) public returns (bytes32 ret) { uint x = uint(uint160(addr)) / 2**32; // Nibble interleave x = x & 0x00000000000000000000000000000000ffffffffffffffffffffffffffffffff; x = (x | (x * 2**64)) & 0x0000000000000000ffffffffffffffff0000000000000000ffffffffffffffff; x = (x | (x * 2**32)) & 0x00000000ffffffff00000000ffffffff00000000ffffffff00000000ffffffff; x = (x | (x * 2**16)) & 0x0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff; x = (x | (x * 2** 8)) & 0x00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff; x = (x | (x * 2** 4)) & 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f; // Hex encode uint h = (x & 0x0808080808080808080808080808080808080808080808080808080808080808) / 8; uint i = (x & 0x0404040404040404040404040404040404040404040404040404040404040404) / 4; uint j = (x & 0x0202020202020202020202020202020202020202020202020202020202020202) / 2; x = x + (h & (i | j)) * 0x27 + 0x3030303030303030303030303030303030303030303030303030303030303030; // Store and load next batch assembly { mstore(0, x) } x = uint160(addr) * 2**96; // Nibble interleave x = x & 0x00000000000000000000000000000000ffffffffffffffffffffffffffffffff; x = (x | (x * 2**64)) & 0x0000000000000000ffffffffffffffff0000000000000000ffffffffffffffff; x = (x | (x * 2**32)) & 0x00000000ffffffff00000000ffffffff00000000ffffffff00000000ffffffff; x = (x | (x * 2**16)) & 0x0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff; x = (x | (x * 2** 8)) & 0x00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff; x = (x | (x * 2** 4)) & 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f; // Hex encode h = (x & 0x0808080808080808080808080808080808080808080808080808080808080808) / 8; i = (x & 0x0404040404040404040404040404040404040404040404040404040404040404) / 4; j = (x & 0x0202020202020202020202020202020202020202020202020202020202020202) / 2; x = x + (h & (i | j)) * 0x27 + 0x3030303030303030303030303030303030303030303030303030303030303030; // Store and hash assembly { mstore(32, x) ret := keccak256(0, 40) } } } )"; auto start = std::chrono::steady_clock::now(); compileBothVersions(sourceCode); double duration = std::chrono::duration(std::chrono::steady_clock::now() - start).count(); // Since run time on an ASan build is not really realistic, we disable this test for those builds. size_t maxDuration = 20; #if !defined(__SANITIZE_ADDRESS__) && defined(__has_feature) #if __has_feature(address_sanitizer) #define __SANITIZE_ADDRESS__ 1 #endif #endif #if __SANITIZE_ADDRESS__ maxDuration = numeric_limits::max(); BOOST_TEST_MESSAGE("Disabled constant optimizer run time check for address sanitizer build."); #endif BOOST_CHECK_MESSAGE(duration <= double(maxDuration), "Compilation of constants took longer than 20 seconds."); compareVersions("hexEncodeTest(address)", u256(0x123456789)); } BOOST_AUTO_TEST_CASE(inconsistency) { // This is a test of a bug in the optimizer. char const* sourceCode = R"( contract Inconsistency { struct Value { uint badnum; uint number; } struct Container { uint[] valueIndices; Value[] values; } Container[] containers; uint[] valueIndices; uint INDEX_ZERO = 0; uint debug; // Called with params: containerIndex=0, valueIndex=0 function levelIII(uint containerIndex, uint valueIndex) private { Container storage container = containers[containerIndex]; Value storage value = container.values[valueIndex]; debug = container.valueIndices[value.number]; } function levelII() private { for (uint i = 0; i < valueIndices.length; i++) { levelIII(INDEX_ZERO, valueIndices[i]); } } function trigger() public returns (uint) { Container storage container = containers.push(); container.values.push(Value({ badnum: 9000, number: 0 })); container.valueIndices.push(); valueIndices.push(); levelII(); return debug; } function DoNotCallButDoNotDelete() public { levelII(); levelIII(1, 2); } } )"; compileBothVersions(sourceCode); compareVersions("trigger()"); } BOOST_AUTO_TEST_CASE(dead_code_elimination_across_assemblies) { // This tests that a runtime-function that is stored in storage in the constructor // is not removed as part of dead code elimination. char const* sourceCode = R"( contract DCE { function () internal returns (uint) stored; constructor() { stored = f; } function f() internal returns (uint) { return 7; } function test() public returns (uint) { return stored(); } } )"; compileBothVersions(sourceCode); compareVersions("test()"); } BOOST_AUTO_TEST_CASE(invalid_state_at_control_flow_join) { char const* sourceCode = R"( contract Test { uint256 public totalSupply = 100; function f() public returns (uint r) { if (false) r = totalSupply; totalSupply -= 10; } function test() public returns (uint) { f(); return this.totalSupply(); } } )"; compileBothVersions(sourceCode); compareVersions("test()"); } BOOST_AUTO_TEST_CASE(init_empty_dynamic_arrays) { // This is not so much an optimizer test, but rather a test // that allocating empty arrays is implemented efficiently. // In particular, initializing a dynamic memory array does // not use any memory. char const* sourceCode = R"( contract Test { function f() public pure returns (uint r) { uint[][] memory x = new uint[][](20000); return x.length; } } )"; compileBothVersions(sourceCode); compareVersions("f()"); BOOST_CHECK_LE(m_gasUsedNonOptimized, 1900000); BOOST_CHECK_LE(1600000, m_gasUsedNonOptimized); } BOOST_AUTO_TEST_CASE(optimise_multi_stores) { char const* sourceCode = R"( contract Test { struct S { uint16 a; uint16 b; uint16[3] c; uint[] dyn; } uint padding; S[] s; function f() public returns (uint16, uint16, uint16[3] memory, uint) { uint16[3] memory c; c[0] = 7; c[1] = 8; c[2] = 9; s.push(S(1, 2, c, new uint[](4))); return (s[0].a, s[0].b, s[0].c, s[0].dyn[2]); } } )"; compileBothVersions(sourceCode); compareVersions("f()"); BOOST_CHECK_EQUAL(numInstructions(m_nonOptimizedBytecode, Instruction::SSTORE), 8); BOOST_CHECK_EQUAL(numInstructions(m_optimizedBytecode, Instruction::SSTORE), 7); } BOOST_AUTO_TEST_CASE(optimise_constant_to_codecopy) { char const* sourceCode = R"( contract C { // We use the state variable so that the functions won't be deemed identical // and be optimised out to the same implementation. uint a; function f() public returns (uint) { a = 1; // This cannot be represented well with the `CalculateMethod`, // hence the decision will be between `LiteralMethod` and `CopyMethod`. return 0x1234123412431234123412412342112341234124312341234124; } function g() public returns (uint) { a = 2; return 0x1234123412431234123412412342112341234124312341234124; } function h() public returns (uint) { a = 3; return 0x1234123412431234123412412342112341234124312341234124; } function i() public returns (uint) { a = 4; return 0x1234123412431234123412412342112341234124312341234124; } } )"; compileBothVersions(sourceCode, 0, "C", 50); compareVersions("f()"); compareVersions("g()"); compareVersions("h()"); compareVersions("i()"); // This is counting in the deployed code. BOOST_CHECK_EQUAL(numInstructions(m_nonOptimizedBytecode, Instruction::CODECOPY), 0); BOOST_CHECK_EQUAL(numInstructions(m_optimizedBytecode, Instruction::CODECOPY), 4); } BOOST_AUTO_TEST_CASE(byte_access) { char const* sourceCode = R"( contract C { function f(bytes32 x) public returns (byte r) { assembly { r := and(byte(x, 31), 0xff) } } } )"; compileBothVersions(sourceCode); compareVersions("f(bytes32)", u256("0x1223344556677889900112233445566778899001122334455667788990011223")); } BOOST_AUTO_TEST_CASE(shift_optimizer_bug) { char const* sourceCode = R"( contract C { function f(uint x) public returns (uint) { return (x << 1) << type(uint).max; } function g(uint x) public returns (uint) { return (x >> 1) >> type(uint).max; } } )"; compileBothVersions(sourceCode); compareVersions("f(uint256)", 7); compareVersions("g(uint256)", u256(-1)); } BOOST_AUTO_TEST_CASE(avoid_double_cleanup) { char const* sourceCode = R"( contract C { receive() external payable { abi.encodePacked(uint200(0)); } } )"; compileBothVersions(sourceCode, 0, "C", 50); // Check that there is no double AND instruction in the resulting code BOOST_CHECK_EQUAL(numInstructions(m_nonOptimizedBytecode, Instruction::AND), 1); } BOOST_AUTO_TEST_SUITE_END() } // end namespaces