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Calldata byte arrays stored on the stack.

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This commit is contained in:
Christian
2015-02-16 19:35:53 +01:00
parent 971cc9b5b9
commit a33fa270f6
6 changed files with 69 additions and 25 deletions
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CompilerUtils.cpp
+21 -13
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@@ -70,9 +70,12 @@ void CompilerUtils::storeInMemoryDynamic(Type const& _type, bool _padToWordBound
if (type.getLocation() == ByteArrayType::Location::CallData)
{
m_context << eth::Instruction::CALLDATASIZE << u256(0) << eth::Instruction::DUP3
<< eth::Instruction::CALLDATACOPY
<< eth::Instruction::CALLDATASIZE << eth::Instruction::ADD;
// 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
<< eth::Instruction::CALLDATACOPY
<< eth::Instruction::DUP3 << eth::Instruction::ADD
<< eth::Instruction::SWAP2 << eth::Instruction::POP << eth::Instruction::POP;
}
else
{
@@ -171,29 +174,32 @@ void CompilerUtils::copyByteArrayToStorage(ByteArrayType const& _targetType,
{
case ByteArrayType::Location::CallData:
{
// @todo this does not take length into account. It also assumes that after "CALLDATALENGTH" we only have zeros.
// This also assumes that after "length" we only have zeros, i.e. it cannot be used to
// slice a byte array from calldata.
// stack: source_offset source_len target_ref
// fetch old length and convert to words
m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD;
m_context << u256(31) << eth::Instruction::ADD
<< u256(32) << eth::Instruction::SWAP1 << eth::Instruction::DIV;
// stack here: target_ref target_length_words
// stack here: source_offset source_len target_ref target_length_words
// actual array data is stored at SHA3(storage_offset)
m_context << eth::Instruction::DUP2;
CompilerUtils(m_context).computeHashStatic();
// compute target_data_end
m_context << eth::Instruction::DUP1 << eth::Instruction::SWAP2 << eth::Instruction::ADD
<< eth::Instruction::SWAP1;
// stack here: target_ref target_data_end target_data_ref
// stack here: source_offset source_len target_ref target_data_end target_data_ref
// store length (in bytes)
m_context << eth::Instruction::CALLDATASIZE;
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP5 << eth::Instruction::SSTORE;
m_context << eth::Instruction::DUP4 << eth::Instruction::DUP1 << eth::Instruction::DUP5
<< eth::Instruction::SSTORE;
// jump to end if length is zero
m_context << eth::Instruction::ISZERO;
eth::AssemblyItem copyLoopEnd = m_context.newTag();
m_context.appendConditionalJumpTo(copyLoopEnd);
// store start offset
m_context << u256(0);
// stack now: target_ref target_data_end target_data_ref calldata_offset
m_context << eth::Instruction::DUP5;
// stack now: source_offset source_len target_ref target_data_end target_data_ref calldata_offset
eth::AssemblyItem copyLoopStart = m_context.newTag();
m_context << copyLoopStart
// copy from calldata and store
@@ -204,16 +210,18 @@ void CompilerUtils::copyByteArrayToStorage(ByteArrayType const& _targetType,
// increment calldata_offset by 32
<< eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD
// check for loop condition
<< eth::Instruction::DUP1 << eth::Instruction::CALLDATASIZE << eth::Instruction::GT;
<< eth::Instruction::DUP1 << eth::Instruction::DUP6 << eth::Instruction::GT;
m_context.appendConditionalJumpTo(copyLoopStart);
m_context << eth::Instruction::POP;
m_context << copyLoopEnd;
// now clear leftover bytes of the old value
// stack now: target_ref target_data_end target_data_ref
// stack now: source_offset source_len target_ref target_data_end target_data_ref
clearStorageLoop();
// stack now: source_offset source_len target_ref target_data_end
m_context << eth::Instruction::POP;
m_context << eth::Instruction::POP << eth::Instruction::SWAP2
<< eth::Instruction::POP << eth::Instruction::POP;
break;
}
case ByteArrayType::Location::Storage: