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Copy routines for non-byte arrays.

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This commit is contained in:
chriseth
2015-06-24 12:18:19 +02:00
parent fd1a01bbce
commit 1add48a652
5 changed files with 213 additions and 127 deletions
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ArrayUtils.cpp
+175
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@@ -231,6 +231,181 @@ void ArrayUtils::copyArrayToStorage(ArrayType const& _targetType, ArrayType cons
m_context << u256(0);
}
void ArrayUtils::copyArrayToMemory(const ArrayType& _sourceType, bool _padToWordBoundaries) const
{
solAssert(
_sourceType.getBaseType()->getCalldataEncodedSize() > 0,
"Nested arrays not yet implemented here."
);
unsigned baseSize = 1;
if (!_sourceType.isByteArray())
// We always pad the elements, regardless of _padToWordBoundaries.
baseSize = _sourceType.getBaseType()->getCalldataEncodedSize();
if (_sourceType.location() == DataLocation::CallData)
{
if (!_sourceType.isDynamicallySized())
m_context << _sourceType.getLength();
if (_sourceType.getBaseType()->getCalldataEncodedSize() > 1)
m_context << u256(baseSize) << eth::Instruction::MUL;
// stack: target source_offset source_len
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3 << eth::Instruction::DUP5;
// stack: target source_offset source_len source_len source_offset target
m_context << eth::Instruction::CALLDATACOPY;
m_context << eth::Instruction::DUP3 << eth::Instruction::ADD;
m_context << eth::Instruction::SWAP2 << eth::Instruction::POP << eth::Instruction::POP;
}
else if (_sourceType.location() == DataLocation::Memory)
{
// memcpy using the built-in contract
retrieveLength(_sourceType);
if (_sourceType.isDynamicallySized())
{
// change pointer to data part
m_context << eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD;
m_context << eth::Instruction::SWAP1;
}
// convert length to size
if (baseSize > 1)
m_context << u256(baseSize) << eth::Instruction::MUL;
// stack: <target> <source> <size>
//@TODO do not use ::CALL if less than 32 bytes?
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::DUP4;
CompilerUtils(m_context).memoryCopy();
m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
// stack: <target> <size>
bool paddingNeeded = false;
if (_sourceType.isDynamicallySized())
paddingNeeded = _padToWordBoundaries && ((baseSize % 32) != 0);
else
paddingNeeded = _padToWordBoundaries && (((_sourceType.getLength() * baseSize) % 32) != 0);
if (paddingNeeded)
{
// stack: <target> <size>
m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2 << eth::Instruction::ADD;
// stack: <length> <target + size>
m_context << eth::Instruction::SWAP1 << u256(31) << eth::Instruction::AND;
// stack: <target + size> <remainder = size % 32>
eth::AssemblyItem skip = m_context.newTag();
if (_sourceType.isDynamicallySized())
{
m_context << eth::Instruction::DUP1 << eth::Instruction::ISZERO;
m_context.appendConditionalJumpTo(skip);
}
// round off, load from there.
// stack <target + size> <remainder = size % 32>
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3;
m_context << eth::Instruction::SUB;
// stack: target+size remainder <target + size - remainder>
m_context << eth::Instruction::DUP1 << eth::Instruction::MLOAD;
// Now we AND it with ~(2**(8 * (32 - remainder)) - 1)
m_context << u256(1);
m_context << eth::Instruction::DUP4 << u256(32) << eth::Instruction::SUB;
// stack: ...<v> 1 <32 - remainder>
m_context << u256(0x100) << eth::Instruction::EXP << eth::Instruction::SUB;
m_context << eth::Instruction::NOT << eth::Instruction::AND;
// stack: target+size remainder target+size-remainder <v & ...>
m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE;
// stack: target+size remainder target+size-remainder
m_context << u256(32) << eth::Instruction::ADD;
// stack: target+size remainder <new_padded_end>
m_context << eth::Instruction::SWAP2 << eth::Instruction::POP;
if (_sourceType.isDynamicallySized())
m_context << skip.tag();
// stack <target + "size"> <remainder = size % 32>
m_context << eth::Instruction::POP;
}
else
// stack: <target> <size>
m_context << eth::Instruction::ADD;
}
else
{
solAssert(_sourceType.location() == DataLocation::Storage, "");
unsigned storageBytes = _sourceType.getBaseType()->getStorageBytes();
u256 storageSize = _sourceType.getBaseType()->getStorageSize();
solAssert(storageSize > 1 || (storageSize == 1 && storageBytes > 0), "");
m_context << eth::Instruction::POP; // remove offset, arrays always start new slot
retrieveLength(_sourceType);
// stack here: memory_offset storage_offset length
// jump to end if length is zero
m_context << eth::Instruction::DUP1 << eth::Instruction::ISZERO;
eth::AssemblyItem loopEnd = m_context.newTag();
m_context.appendConditionalJumpTo(loopEnd);
// compute memory end offset
if (baseSize > 1)
// convert length to memory size
m_context << u256(baseSize) << eth::Instruction::MUL;
m_context << eth::Instruction::DUP3 << eth::Instruction::ADD << eth::Instruction::SWAP2;
if (_sourceType.isDynamicallySized())
{
// actual array data is stored at SHA3(storage_offset)
m_context << eth::Instruction::SWAP1;
CompilerUtils(m_context).computeHashStatic();
m_context << eth::Instruction::SWAP1;
}
// stack here: memory_end_offset storage_data_offset memory_offset
bool haveByteOffset = !_sourceType.isByteArray() && storageBytes <= 16;
if (haveByteOffset)
m_context << u256(0) << eth::Instruction::SWAP1;
// stack here: memory_end_offset storage_data_offset [storage_byte_offset] memory_offset
eth::AssemblyItem loopStart = m_context.newTag();
m_context << loopStart;
// load and store
if (_sourceType.isByteArray())
{
// Packed both in storage and memory.
m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE;
// increment storage_data_offset by 1
m_context << eth::Instruction::SWAP1 << u256(1) << eth::Instruction::ADD;
// increment memory offset by 32
m_context << eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD;
}
else
{
// stack here: memory_end_offset storage_data_offset [storage_byte_offset] memory_offset
if (haveByteOffset)
m_context << eth::Instruction::DUP3 << eth::Instruction::DUP3;
else
m_context << eth::Instruction::DUP2 << u256(0);
StorageItem(m_context, *_sourceType.getBaseType()).retrieveValue(SourceLocation(), true);
CompilerUtils(m_context).storeInMemoryDynamic(*_sourceType.getBaseType());
// increment storage_data_offset and byte offset
if (haveByteOffset)
incrementByteOffset(storageBytes, 2, 3);
else
{
m_context << eth::Instruction::SWAP1;
m_context << storageSize << eth::Instruction::ADD;
m_context << eth::Instruction::SWAP1;
}
}
// check for loop condition
m_context << eth::Instruction::DUP1 << eth::dupInstruction(haveByteOffset ? 5 : 4) << eth::Instruction::GT;
m_context.appendConditionalJumpTo(loopStart);
// stack here: memory_end_offset storage_data_offset [storage_byte_offset] memory_offset
if (haveByteOffset)
m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
if (_padToWordBoundaries && baseSize % 32 != 0)
{
// memory_end_offset - start is the actual length (we want to compute the ceil of).
// memory_offset - start is its next multiple of 32, but it might be off by 32.
// so we compute: memory_end_offset += (memory_offset - memory_end_offest) & 31
m_context << eth::Instruction::DUP3 << eth::Instruction::SWAP1 << eth::Instruction::SUB;
m_context << u256(31) << eth::Instruction::AND;
m_context << eth::Instruction::DUP3 << eth::Instruction::ADD;
m_context << eth::Instruction::SWAP2;
}
m_context << loopEnd << eth::Instruction::POP << eth::Instruction::POP;
}
}
void ArrayUtils::clearArray(ArrayType const& _type) const
{
unsigned stackHeightStart = m_context.getStackHeight();