From 7156a01acc822ab66c189435421564afc8b1c922 Mon Sep 17 00:00:00 2001 From: Erik Kundt Date: Fri, 16 Mar 2018 17:06:38 +0100 Subject: [PATCH] Implements pop() for byte arrays. --- libsolidity/codegen/ArrayUtils.cpp | 75 ++++++++++++++++--- test/libsolidity/SolidityEndToEndTest.cpp | 87 +++++++++++++++++++++-- 2 files changed, 146 insertions(+), 16 deletions(-) diff --git a/libsolidity/codegen/ArrayUtils.cpp b/libsolidity/codegen/ArrayUtils.cpp index b434fddd2..096b2d4e7 100644 --- a/libsolidity/codegen/ArrayUtils.cpp +++ b/libsolidity/codegen/ArrayUtils.cpp @@ -830,19 +830,74 @@ void ArrayUtils::popStorageArrayElement(ArrayType const& _type) const if (!_type.isByteArray() && _type.baseType()->storageBytes() < 32) solAssert(_type.baseType()->isValueType(), "Invalid storage size for non-value type."); - // stack: ArrayReference - retrieveLength(_type); - // stack: ArrayReference oldLength - m_context << Instruction::DUP1; - // stack: ArrayReference oldLength oldLength - m_context << Instruction::ISZERO; - m_context.appendConditionalInvalid(); - if (_type.isByteArray()) { + m_context.appendInlineAssembly(R"({ + let slot_value := sload(ref) + switch and(slot_value, 1) + case 0 { + // short byte array + let length := and(div(slot_value, 2), 0x3f) + if iszero(length) { invalid() } + + // Zero-out the suffix of the byte array by masking it. + // Do not zero-out the least significant byte, but mask the + // higher bits of the length. + // (((1<<(8 * (32 - length))) - 1) << 8) + 128 + let mask := add(mul(0x100, sub(exp(0x100, sub(32, length)), 1)), 0x80) + slot_value := and(not(mask), slot_value) + + // Reduce the length by 1 + slot_value := sub(slot_value, 2) + sstore(ref, slot_value) + } + case 1 { + // long byte array + let length := div(slot_value, 2) + mstore(0, ref) + + switch length + case 32 + { + let slot := keccak256(0, 0x20) + let data := sload(slot) + sstore(slot, 0) + data := and(data, not(0xff)) + sstore(ref, or(data, 62)) + } + default + { + let slot := div(sub(length, 1), 32) + let offset := and(sub(length, 1), 0x1f) + slot := add(keccak256(0, 0x20), slot) + let data := sload(slot) + + // Zero-out the suffix of the byte array by masking it. + // ((1<<(8 * (32 - offset))) - 1) + let mask := sub(exp(0x100, sub(32, offset)), 1) + data := and(not(mask), data) + sstore(slot, data) + + // Reduce the length by 1 + slot_value := sub(slot_value, 2) + sstore(ref, slot_value) + } + } + })", {"ref"}); + m_context << Instruction::POP; } else - { + { + + // stack: ArrayReference + retrieveLength(_type); + // stack: ArrayReference oldLength + m_context << Instruction::DUP1; + // stack: ArrayReference oldLength oldLength + m_context << Instruction::ISZERO; + m_context.appendConditionalInvalid(); + + // Stack: ArrayReference oldLength m_context << u256(1) << Instruction::SWAP1 << Instruction::SUB; // Stack ArrayReference newLength @@ -852,7 +907,7 @@ void ArrayUtils::popStorageArrayElement(ArrayType const& _type) const // Stack: ArrayReference newLength storage_slot byte_offset StorageItem(m_context, _type).setToZero(SourceLocation(), true); // Stack: ArrayReference newLength - m_context << Instruction::SSTORE; + m_context << Instruction::SWAP1 << Instruction::SSTORE; } } diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp index b4cf69503..411012233 100644 --- a/test/libsolidity/SolidityEndToEndTest.cpp +++ b/test/libsolidity/SolidityEndToEndTest.cpp @@ -5115,21 +5115,23 @@ BOOST_AUTO_TEST_CASE(array_pop) { char const* sourceCode = R"( contract c { + uint256 a; uint[] data; - function test() public returns (uint x, uint y, uint l) { + function test() public returns (uint x, uint l) { data.push(7); x = data.push(3); data.pop(); - y = data.push(2); + x = data.length; + data.pop(); l = data.length; } } )"; compileAndRun(sourceCode); - ABI_CHECK(callContractFunction("test()"), encodeArgs(2, 2, 2)); + ABI_CHECK(callContractFunction("test()"), encodeArgs(1, 0)); } -BOOST_AUTO_TEST_CASE(array_pop_empty) +BOOST_AUTO_TEST_CASE(array_pop_empty_exception) { char const* sourceCode = R"( contract c { @@ -5144,7 +5146,23 @@ BOOST_AUTO_TEST_CASE(array_pop_empty) ABI_CHECK(callContractFunction("test()"), encodeArgs()); } -BOOST_AUTO_TEST_CASE(bytearray_pop) +BOOST_AUTO_TEST_CASE(array_pop_storage_empty) +{ + char const* sourceCode = R"( + contract c { + uint[] data; + function test() public { + data.push(7); + data.pop(); + } + } + )"; + compileAndRun(sourceCode); + ABI_CHECK(callContractFunction("test()"), encodeArgs()); + BOOST_CHECK(storageEmpty(m_contractAddress)); +} + +BOOST_AUTO_TEST_CASE(byte_array_pop) { char const* sourceCode = R"( contract c { @@ -5163,13 +5181,31 @@ BOOST_AUTO_TEST_CASE(bytearray_pop) ABI_CHECK(callContractFunction("test()"), encodeArgs(2, 1, 1)); } -BOOST_AUTO_TEST_CASE(bytearray_pop_empty) +BOOST_AUTO_TEST_CASE(byte_array_pop_long) +{ + char const* sourceCode = R"( + contract c { + bytes data; + function test() public returns (uint l) { + for (uint i = 0; i < 33; i++) + data.push(byte(i)); + data.pop(); + l = data.length; + } + } + )"; + compileAndRun(sourceCode); + ABI_CHECK(callContractFunction("test()"), encodeArgs(32)); +} + +BOOST_AUTO_TEST_CASE(byte_array_pop_empty_exception) { char const* sourceCode = R"( contract c { bytes data; function test() public returns (bool) { data.pop(); + return true; } } )"; @@ -5177,6 +5213,45 @@ BOOST_AUTO_TEST_CASE(bytearray_pop_empty) ABI_CHECK(callContractFunction("test()"), encodeArgs()); } +BOOST_AUTO_TEST_CASE(byte_array_pop_storage_empty) +{ + char const* sourceCode = R"( + contract c { + bytes data; + function test() public { + data.push(7); + data.push(5); + data.push(3); + data.pop(); + data.pop(); + data.pop(); + } + } + )"; + compileAndRun(sourceCode); + ABI_CHECK(callContractFunction("test()"), encodeArgs()); + BOOST_CHECK(storageEmpty(m_contractAddress)); +} + +BOOST_AUTO_TEST_CASE(byte_array_pop_storage_empty_long) +{ + char const* sourceCode = R"( + contract c { + bytes data; + function test() public returns (uint l) { + for (uint i = 0; i < 33; i++) + data.push(3); + for (uint j = 0; j < 33; j++) + data.pop(); + l = data.length; + } + } + )"; + compileAndRun(sourceCode); + ABI_CHECK(callContractFunction("test()"), encodeArgs(0)); + BOOST_CHECK(storageEmpty(m_contractAddress)); +} + BOOST_AUTO_TEST_CASE(external_array_args) { char const* sourceCode = R"(