diff options
| -rw-r--r-- | Changelog.md | 1 | ||||
| -rw-r--r-- | docs/miscellaneous.rst | 55 | ||||
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.cpp | 5 | ||||
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.h | 2 | ||||
| -rw-r--r-- | libsolidity/codegen/LValue.cpp | 1 | ||||
| -rw-r--r-- | test/libsolidity/Assembly.cpp | 2 | ||||
| -rw-r--r-- | test/libsolidity/SolidityEndToEndTest.cpp | 28 |
7 files changed, 89 insertions, 5 deletions
diff --git a/Changelog.md b/Changelog.md index 58cf1484..c76d10e1 100644 --- a/Changelog.md +++ b/Changelog.md @@ -7,6 +7,7 @@ Features: Bugfixes: * Code generator: throw if calling the identity precompile failed during memory (array) copying. * Type checker: string literals that are not valid UTF-8 cannot be converted to string type + * Code generator: any non-zero value given as a boolean argument is now converted into 1. ### 0.4.6 (2016-11-22) diff --git a/docs/miscellaneous.rst b/docs/miscellaneous.rst index e479d5f6..81e39a26 100644 --- a/docs/miscellaneous.rst +++ b/docs/miscellaneous.rst @@ -56,6 +56,8 @@ So for the following contract snippet:: The position of ``data[4][9].b`` is at ``keccak256(uint256(9) . keccak256(uint256(4) . uint256(1))) + 1``. +.. index: memory layout + **************** Layout in Memory **************** @@ -72,7 +74,8 @@ Solidity always places new objects at the free memory pointer and memory is neve .. warning:: There are some operations in Solidity that need a temporary memory area larger than 64 bytes and therefore will not fit into the scratch space. They will be placed where the free memory points to, but given their short lifecycle, the pointer is not updated. The memory may or may not be zeroed out. Because of this, one shouldn't expect the free memory to be zeroed out. -.. index: memory layout + +.. index: calldata layout ******************* Layout of Call Data @@ -85,6 +88,56 @@ specification ABI specification requires arguments to be padded to multiples of 32 bytes. The internal function calls use a different convention. + +.. index: variable cleanup + +********************************* +Internals - Cleaning Up Variables +********************************* + +When a value is shorter than 256-bit, in some cases the remaining bits +must be cleaned. +The Solidity compiler is designed to clean such remaining bits before any operations +that might be adversely affected by the potential garbage in the remaining bits. +For example, before writing a value to the memory, the remaining bits need +to be cleared because the memory contents can be used for computing +hashes or sent as the data of a message call. Similarly, before +storing a value in the storage, the remaining bits need to be cleaned +because otherwise the garbled value can be observed. + +On the other hand, we do not clean the bits if the immediately +following operation is not affected. For instance, since any non-zero +value is considered ``true`` by ``JUMPI`` instruction, we do not clean +the boolean values before they are used as the condition for +``JUMPI``. + +In addition to the design principle above, the Solidity compiler +cleans input data when it is loaded onto the stack. + +Different types have different rules for cleaning up invalid values: + ++---------------+---------------+-------------------+ +|Type |Valid Values |Invalid Values Mean| ++===============+===============+===================+ +|enum of n |0 until n - 1 |exception | +|members | | | ++---------------+---------------+-------------------+ +|bool |0 or 1 |1 | ++---------------+---------------+-------------------+ +|signed integers|sign-extended |currently silently | +| |word |wraps; in the | +| | |future exceptions | +| | |will be thrown | +| | | | +| | | | ++---------------+---------------+-------------------+ +|unsigned |higher bits |currently silently | +|integers |zeroed |wraps; in the | +| | |future exceptions | +| | |will be thrown | ++---------------+---------------+-------------------+ + + ***************** Esoteric Features ***************** diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index a8299626..7c159ff7 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -926,6 +926,8 @@ unsigned CompilerUtils::loadFromMemoryHelper(Type const& _type, bool _fromCallda if (leftAligned) m_context << shiftFactor << Instruction::MUL; } + if (_fromCalldata) + convertType(_type, _type, true); return numBytes; } @@ -940,7 +942,7 @@ void CompilerUtils::cleanHigherOrderBits(IntegerType const& _typeOnStack) m_context << ((u256(1) << _typeOnStack.numBits()) - 1) << Instruction::AND; } -unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) const +unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) { unsigned numBytes = _type.calldataEncodedSize(_padToWordBoundaries); bool leftAligned = _type.category() == Type::Category::FixedBytes; @@ -949,6 +951,7 @@ unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBou else { solAssert(numBytes <= 32, "Memory store of more than 32 bytes requested."); + convertType(_type, _type, true); if (numBytes != 32 && !leftAligned && !_padToWordBoundaries) // shift the value accordingly before storing m_context << (u256(1) << ((32 - numBytes) * 8)) << Instruction::MUL; diff --git a/libsolidity/codegen/CompilerUtils.h b/libsolidity/codegen/CompilerUtils.h index 4baf48ff..0a5d8e1c 100644 --- a/libsolidity/codegen/CompilerUtils.h +++ b/libsolidity/codegen/CompilerUtils.h @@ -185,7 +185,7 @@ private: void cleanHigherOrderBits(IntegerType const& _typeOnStack); /// Prepares the given type for storing in memory by shifting it if necessary. - unsigned prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) const; + unsigned prepareMemoryStore(Type const& _type, bool _padToWordBoundaries); /// Loads type from memory assuming memory offset is on stack top. unsigned loadFromMemoryHelper(Type const& _type, bool _fromCalldata, bool _padToWordBoundaries); diff --git a/libsolidity/codegen/LValue.cpp b/libsolidity/codegen/LValue.cpp index 23fe2d4e..b9e141d8 100644 --- a/libsolidity/codegen/LValue.cpp +++ b/libsolidity/codegen/LValue.cpp @@ -223,7 +223,6 @@ void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _loc { solAssert(m_dataType->storageBytes() <= 32, "Invalid storage bytes size."); solAssert(m_dataType->storageBytes() > 0, "Invalid storage bytes size."); - if (m_dataType->storageBytes() == 32) { solAssert(m_dataType->sizeOnStack() == 1, "Invalid stack size."); diff --git a/test/libsolidity/Assembly.cpp b/test/libsolidity/Assembly.cpp index bdbe7dba..155dd5c9 100644 --- a/test/libsolidity/Assembly.cpp +++ b/test/libsolidity/Assembly.cpp @@ -116,7 +116,7 @@ BOOST_AUTO_TEST_CASE(location_test) shared_ptr<string const> n = make_shared<string>(""); AssemblyItems items = compileContract(sourceCode); vector<SourceLocation> locations = - vector<SourceLocation>(16, SourceLocation(2, 75, n)) + + vector<SourceLocation>(18, SourceLocation(2, 75, n)) + vector<SourceLocation>(27, SourceLocation(20, 72, n)) + vector<SourceLocation>{SourceLocation(42, 51, n), SourceLocation(65, 67, n)} + vector<SourceLocation>(2, SourceLocation(58, 67, n)) + diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp index aa1eb20a..2df6e9f2 100644 --- a/test/libsolidity/SolidityEndToEndTest.cpp +++ b/test/libsolidity/SolidityEndToEndTest.cpp @@ -4591,6 +4591,34 @@ BOOST_AUTO_TEST_CASE(super_overload) BOOST_CHECK(callContractFunction("h()") == encodeArgs(2)); } +BOOST_AUTO_TEST_CASE(bool_conversion) +{ + char const* sourceCode = R"( + contract C { + function f(bool _b) returns(uint) { + if (_b) + return 1; + else + return 0; + } + function g(bool _in) returns (bool _out) { + _out = _in; + } + } + )"; + compileAndRun(sourceCode, 0, "C"); + BOOST_CHECK(callContractFunction("f(bool)", 0) == encodeArgs(0)); + BOOST_CHECK(callContractFunction("f(bool)", 1) == encodeArgs(1)); + BOOST_CHECK(callContractFunction("f(bool)", 2) == encodeArgs(1)); + BOOST_CHECK(callContractFunction("f(bool)", 3) == encodeArgs(1)); + BOOST_CHECK(callContractFunction("f(bool)", 255) == encodeArgs(1)); + BOOST_CHECK(callContractFunction("g(bool)", 0) == encodeArgs(0)); + BOOST_CHECK(callContractFunction("g(bool)", 1) == encodeArgs(1)); + BOOST_CHECK(callContractFunction("g(bool)", 2) == encodeArgs(1)); + BOOST_CHECK(callContractFunction("g(bool)", 3) == encodeArgs(1)); + BOOST_CHECK(callContractFunction("g(bool)", 255) == encodeArgs(1)); +} + BOOST_AUTO_TEST_CASE(packed_storage_signed) { char const* sourceCode = R"( |