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Moved copy code to CompilerUtils.

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This commit is contained in:
Christian 2015-02-11 14:32:46 +01:00
parent 8a2879a603
commit 9b8cf4af1d
4 changed files with 238 additions and 176 deletions
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213
CompilerUtils.cpp
View File

@ -64,6 +64,7 @@ unsigned CompilerUtils::loadFromMemory(unsigned _offset, unsigned _bytes, bool _
unsigned CompilerUtils::storeInMemory(unsigned _offset, Type const& _type, bool _padToWordBoundaries) unsigned CompilerUtils::storeInMemory(unsigned _offset, Type const& _type, bool _padToWordBoundaries)
{ {
solAssert(_type.getCategory() != Type::Category::ByteArray, "Unable to statically store dynamic type.");
unsigned numBytes = prepareMemoryStore(_type, _padToWordBoundaries); unsigned numBytes = prepareMemoryStore(_type, _padToWordBoundaries);
if (numBytes > 0) if (numBytes > 0)
m_context << u256(_offset) << eth::Instruction::MSTORE; m_context << u256(_offset) << eth::Instruction::MSTORE;
@ -72,11 +73,47 @@ unsigned CompilerUtils::storeInMemory(unsigned _offset, Type const& _type, bool
void CompilerUtils::storeInMemoryDynamic(Type const& _type, bool _padToWordBoundaries) void CompilerUtils::storeInMemoryDynamic(Type const& _type, bool _padToWordBoundaries)
{ {
unsigned numBytes = prepareMemoryStore(_type, _padToWordBoundaries); if (_type.getCategory() == Type::Category::ByteArray)
if (numBytes > 0)
{ {
m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE; auto const& type = dynamic_cast<ByteArrayType const&>(_type);
m_context << u256(numBytes) << eth::Instruction::ADD; solAssert(type.getLocation() == ByteArrayType::Location::Storage, "Non-storage byte arrays not yet implemented.");
m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD;
// stack here: memory_offset storage_offset length_bytes
// 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
m_context << eth::Instruction::DUP3 << eth::Instruction::ADD << eth::Instruction::SWAP2;
// 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
eth::AssemblyItem loopStart = m_context.newTag();
m_context << loopStart
// load and store
<< eth::Instruction::DUP2 << eth::Instruction::SLOAD
<< eth::Instruction::DUP2 << eth::Instruction::MSTORE
// increment storage_data_offset by 1
<< eth::Instruction::SWAP1 << u256(1) << eth::Instruction::ADD
// increment memory offset by 32
<< eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD
// check for loop condition
<< eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::GT;
m_context.appendConditionalJumpTo(loopStart);
m_context << loopEnd << eth::Instruction::POP << eth::Instruction::POP;
}
else
{
unsigned numBytes = prepareMemoryStore(_type, _padToWordBoundaries);
if (numBytes > 0)
{
m_context << eth::Instruction::DUP2 << eth::Instruction::MSTORE;
m_context << u256(numBytes) << eth::Instruction::ADD;
}
} }
} }
@ -122,7 +159,153 @@ void CompilerUtils::computeHashStatic(Type const& _type, bool _padToWordBoundari
m_context << u256(length) << u256(0) << eth::Instruction::SHA3; m_context << u256(length) << u256(0) << eth::Instruction::SHA3;
} }
unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) void CompilerUtils::copyByteArrayToStorage(ByteArrayType const& _targetType,
ByteArrayType const& _sourceType) const
{
// stack layout: [source_ref] target_ref (top)
// need to leave target_ref on the stack at the end
solAssert(_targetType.getLocation() == ByteArrayType::Location::Storage, "");
switch (_sourceType.getLocation())
{
case ByteArrayType::Location::CallData:
{
// @todo this does not take length into account. It also assumes that after "CALLDATALENGTH" we only have zeros.
// 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
// 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
// store length (in bytes)
if (_sourceType.getOffset() == 0)
m_context << eth::Instruction::CALLDATASIZE;
else
m_context << _sourceType.getOffset() << eth::Instruction::CALLDATASIZE << eth::Instruction::SUB;
m_context << 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);
m_context << _sourceType.getOffset();
// stack now: target_ref target_data_end target_data_ref calldata_offset
eth::AssemblyItem copyLoopStart = m_context.newTag();
m_context << copyLoopStart
// copy from calldata and store
<< eth::Instruction::DUP1 << eth::Instruction::CALLDATALOAD
<< eth::Instruction::DUP3 << eth::Instruction::SSTORE
// increment target_data_ref by 1
<< eth::Instruction::SWAP1 << u256(1) << eth::Instruction::ADD
// 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;
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
clearStorageLoop();
m_context << eth::Instruction::POP;
break;
}
case ByteArrayType::Location::Storage:
{
// this copies source to target and also clears target if it was larger
// stack: source_ref target_ref
// store target_ref
m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2;
// fetch lengthes
m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD << eth::Instruction::SWAP2
<< eth::Instruction::DUP1 << eth::Instruction::SLOAD;
// stack: target_ref target_len_bytes target_ref source_ref source_len_bytes
// store new target length
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::SSTORE;
// compute hashes (data positions)
m_context << eth::Instruction::SWAP2;
CompilerUtils(m_context).computeHashStatic();
m_context << eth::Instruction::SWAP1;
CompilerUtils(m_context).computeHashStatic();
// stack: target_ref target_len_bytes source_len_bytes target_data_pos source_data_pos
// convert lengthes from bytes to storage slots
m_context << u256(31) << u256(32) << eth::Instruction::DUP1 << eth::Instruction::DUP3
<< eth::Instruction::DUP8 << eth::Instruction::ADD << eth::Instruction::DIV
<< eth::Instruction::SWAP2
<< eth::Instruction::DUP6 << eth::Instruction::ADD << eth::Instruction::DIV;
// stack: target_ref target_len_bytes source_len_bytes target_data_pos source_data_pos target_len source_len
// @todo we might be able to go without a third counter
m_context << u256(0);
// stack: target_ref target_len_bytes source_len_bytes target_data_pos source_data_pos target_len source_len counter
eth::AssemblyItem copyLoopStart = m_context.newTag();
m_context << copyLoopStart;
// check for loop condition
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3
<< eth::Instruction::GT << eth::Instruction::ISZERO;
eth::AssemblyItem copyLoopEnd = m_context.newTag();
m_context.appendConditionalJumpTo(copyLoopEnd);
// copy
m_context << eth::Instruction::DUP4 << eth::Instruction::DUP2 << eth::Instruction::ADD
<< eth::Instruction::SLOAD
<< eth::Instruction::DUP6 << eth::Instruction::DUP3 << eth::Instruction::ADD
<< eth::Instruction::SSTORE;
// increment
m_context << u256(1) << eth::Instruction::ADD;
m_context.appendJumpTo(copyLoopStart);
m_context << copyLoopEnd;
// zero-out leftovers in target
// stack: target_ref target_len_bytes source_len_bytes target_data_pos source_data_pos target_len source_len counter
// add counter to target_data_pos
m_context << eth::Instruction::DUP5 << eth::Instruction::ADD
<< eth::Instruction::SWAP5 << eth::Instruction::POP;
// stack: target_ref target_len_bytes target_data_pos_updated target_data_pos source_data_pos target_len source_len
// add length to target_data_pos to get target_data_end
m_context << eth::Instruction::POP << eth::Instruction::DUP3 << eth::Instruction::ADD
<< eth::Instruction::SWAP4
<< eth::Instruction::POP << eth::Instruction::POP << eth::Instruction::POP;
// stack: target_ref target_data_end target_data_pos_updated
clearStorageLoop();
m_context << eth::Instruction::POP;
break;
}
default:
solAssert(false, "Given byte array location not implemented.");
}
}
void CompilerUtils::clearByteArray(ByteArrayType const& _type) const
{
solAssert(_type.getLocation() == ByteArrayType::Location::Storage, "");
// fetch length
m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD;
// set length to zero
m_context << u256(0) << eth::Instruction::DUP3 << eth::Instruction::SSTORE;
// convert length from bytes to storage slots
m_context << u256(31) << eth::Instruction::ADD
<< u256(32) << eth::Instruction::SWAP1 << eth::Instruction::DIV;
// compute data positions
m_context << eth::Instruction::SWAP1;
CompilerUtils(m_context).computeHashStatic();
// stack: len data_pos
m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2 << eth::Instruction::ADD
<< eth::Instruction::SWAP1;
clearStorageLoop();
// cleanup
m_context << eth::Instruction::POP;
}
unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) const
{ {
unsigned _encodedSize = _type.getCalldataEncodedSize(); unsigned _encodedSize = _type.getCalldataEncodedSize();
unsigned numBytes = _padToWordBoundaries ? getPaddedSize(_encodedSize) : _encodedSize; unsigned numBytes = _padToWordBoundaries ? getPaddedSize(_encodedSize) : _encodedSize;
@ -139,5 +322,25 @@ unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWordBou
return numBytes; return numBytes;
} }
void CompilerUtils::clearStorageLoop() const
{
// stack: end_pos pos
eth::AssemblyItem loopStart = m_context.newTag();
m_context << loopStart;
// check for loop condition
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3
<< eth::Instruction::GT << eth::Instruction::ISZERO;
eth::AssemblyItem zeroLoopEnd = m_context.newTag();
m_context.appendConditionalJumpTo(zeroLoopEnd);
// zero out
m_context << u256(0) << eth::Instruction::DUP2 << eth::Instruction::SSTORE;
// increment
m_context << u256(1) << eth::Instruction::ADD;
m_context.appendJumpTo(loopStart);
// cleanup
m_context << zeroLoopEnd;
m_context << eth::Instruction::POP;
}
} }
} }

13
CompilerUtils.h
View File

@ -75,12 +75,23 @@ public:
/// @note Only works for types of fixed size. /// @note Only works for types of fixed size.
void computeHashStatic(Type const& _type = IntegerType(256), bool _padToWordBoundaries = false); void computeHashStatic(Type const& _type = IntegerType(256), bool _padToWordBoundaries = false);
/// Copies a byte array to a byte array in storage, where the target is assumed to be on the
/// to top of the stay. Leaves a reference to the target on the stack.
void copyByteArrayToStorage(ByteArrayType const& _targetType, ByteArrayType const& _sourceType) const;
/// Clears the length and data elements of the byte array referenced on the stack.
/// Removes the reference from the stack.
void clearByteArray(ByteArrayType const& _type) const;
/// Bytes we need to the start of call data. /// Bytes we need to the start of call data.
/// - The size in bytes of the function (hash) identifier. /// - The size in bytes of the function (hash) identifier.
static const unsigned int dataStartOffset; static const unsigned int dataStartOffset;
private: private:
unsigned prepareMemoryStore(Type const& _type, bool _padToWordBoundaries); unsigned prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) const;
/// Appends a loop that clears all storage between the storage reference at the stack top
/// and the one below it (excluding).
/// Will leave the single value of the end pointer on the stack.
void clearStorageLoop() const;
CompilerContext& m_context; CompilerContext& m_context;
}; };

186
ExpressionCompiler.cpp
View File

@ -105,7 +105,7 @@ bool ExpressionCompiler::visit(UnaryOperation const& _unaryOperation)
break; break;
case Token::Delete: // delete case Token::Delete: // delete
solAssert(m_currentLValue.isValid(), "LValue not retrieved."); solAssert(m_currentLValue.isValid(), "LValue not retrieved.");
m_currentLValue.setToZero(_unaryOperation); m_currentLValue.setToZero(_unaryOperation, *_unaryOperation.getSubExpression().getType());
m_currentLValue.reset(); m_currentLValue.reset();
break; break;
case Token::Inc: // ++ (pre- or postfix) case Token::Inc: // ++ (pre- or postfix)
@ -886,43 +886,7 @@ void ExpressionCompiler::appendArgumentsCopyToMemory(vector<ASTPointer<Expressio
void ExpressionCompiler::appendTypeMoveToMemory(Type const& _type, bool _padToWordBoundaries) void ExpressionCompiler::appendTypeMoveToMemory(Type const& _type, bool _padToWordBoundaries)
{ {
// @TODO move this to CompilerUtils! CompilerUtils(m_context).storeInMemoryDynamic(_type, _padToWordBoundaries);
if (_type.getCategory() == Type::Category::ByteArray)
{
auto const& type = dynamic_cast<ByteArrayType const&>(_type);
solAssert(type.getLocation() == ByteArrayType::Location::Storage, "Non-storage byte arrays not yet implemented.");
m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD;
// stack here: memory_offset storage_offset length_bytes
// 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
m_context << eth::Instruction::DUP3 << eth::Instruction::ADD << eth::Instruction::SWAP2;
// 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
eth::AssemblyItem loopStart = m_context.newTag();
m_context << loopStart
// load and store
<< eth::Instruction::DUP2 << eth::Instruction::SLOAD
<< eth::Instruction::DUP2 << eth::Instruction::MSTORE
// increment storage_data_offset by 1
<< eth::Instruction::SWAP1 << u256(1) << eth::Instruction::ADD
// increment memory offset by 32
<< eth::Instruction::SWAP1 << u256(32) << eth::Instruction::ADD
// check for loop condition
<< eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::GT;
m_context.appendConditionalJumpTo(loopStart);
m_context << loopEnd << eth::Instruction::POP << eth::Instruction::POP;
}
else
CompilerUtils(m_context).storeInMemoryDynamic(_type, _padToWordBoundaries);
} }
void ExpressionCompiler::appendExpressionCopyToMemory(Type const& _expectedType, Expression const& _expression) void ExpressionCompiler::appendExpressionCopyToMemory(Type const& _expectedType, Expression const& _expression)
@ -1097,8 +1061,9 @@ void ExpressionCompiler::LValue::storeValue(Expression const& _expression, Type
solAssert(!_move, "Move assign for non-value types not implemented."); solAssert(!_move, "Move assign for non-value types not implemented.");
solAssert(_sourceType.getCategory() == _expression.getType()->getCategory(), ""); solAssert(_sourceType.getCategory() == _expression.getType()->getCategory(), "");
if (_expression.getType()->getCategory() == Type::Category::ByteArray) if (_expression.getType()->getCategory() == Type::Category::ByteArray)
copyByteArrayToStorage(dynamic_cast<ByteArrayType const&>(*_expression.getType()), CompilerUtils(*m_context).copyByteArrayToStorage(
dynamic_cast<ByteArrayType const&>(_sourceType)); dynamic_cast<ByteArrayType const&>(*_expression.getType()),
dynamic_cast<ByteArrayType const&>(_sourceType));
else if (_expression.getType()->getCategory() == Type::Category::Struct) else if (_expression.getType()->getCategory() == Type::Category::Struct)
{ {
//@todo //@todo
@ -1122,7 +1087,7 @@ void ExpressionCompiler::LValue::storeValue(Expression const& _expression, Type
} }
} }
void ExpressionCompiler::LValue::setToZero(Expression const& _expression) const void ExpressionCompiler::LValue::setToZero(Expression const& _expression, Type const& _type) const
{ {
switch (m_type) switch (m_type)
{ {
@ -1139,20 +1104,21 @@ void ExpressionCompiler::LValue::setToZero(Expression const& _expression) const
break; break;
} }
case LValueType::Storage: case LValueType::Storage:
if (m_size == 0) if (_type.getCategory() == Type::Category::ByteArray)
*m_context << eth::Instruction::POP; CompilerUtils(*m_context).clearByteArray(dynamic_cast<ByteArrayType const&>(_type));
for (unsigned i = 0; i < m_size; ++i) else
{ {
if (i + 1 >= m_size) if (m_size == 0)
*m_context << u256(0) << eth::Instruction::SWAP1 << eth::Instruction::SSTORE; *m_context << eth::Instruction::POP;
else for (unsigned i = 0; i < m_size; ++i)
*m_context << u256(0) << eth::Instruction::DUP2 << eth::Instruction::SSTORE if (i + 1 >= m_size)
<< u256(1) << eth::Instruction::ADD; *m_context << u256(0) << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
else
*m_context << u256(0) << eth::Instruction::DUP2 << eth::Instruction::SSTORE
<< u256(1) << eth::Instruction::ADD;
} }
break; break;
case LValueType::Memory: case LValueType::Memory:
if (!_expression.getType()->isValueType())
break; // no distinction between value and reference for non-value types
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_expression.getLocation()) BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Location type not yet implemented.")); << errinfo_comment("Location type not yet implemented."));
break; break;
@ -1161,7 +1127,6 @@ void ExpressionCompiler::LValue::setToZero(Expression const& _expression) const
<< errinfo_comment("Unsupported location type.")); << errinfo_comment("Unsupported location type."));
break; break;
} }
} }
void ExpressionCompiler::LValue::retrieveValueIfLValueNotRequested(Expression const& _expression) void ExpressionCompiler::LValue::retrieveValueIfLValueNotRequested(Expression const& _expression)
@ -1198,123 +1163,6 @@ void ExpressionCompiler::LValue::fromIdentifier(Identifier const& _identifier, D
<< errinfo_comment("Identifier type not supported or identifier not found.")); << errinfo_comment("Identifier type not supported or identifier not found."));
} }
void ExpressionCompiler::LValue::copyByteArrayToStorage(ByteArrayType const& _targetType,
ByteArrayType const& _sourceType) const
{
// stack layout: [source_ref] target_ref (head)
// need to leave target_ref on the stack at the end
solAssert(m_type == LValueType::Storage, "");
solAssert(_targetType.getLocation() == ByteArrayType::Location::Storage, "");
// @TODO move this to CompilerUtils!
switch (_sourceType.getLocation())
{
case ByteArrayType::Location::CallData:
{
// @todo this does not take length into account. It also assumes that after "CALLDATALENGTH" we only have zeros.
// add some useful constants
*m_context << u256(32) << u256(1);
// stack here: target_ref 32 1
// store length (in bytes)
if (_sourceType.getOffset() == 0)
*m_context << eth::Instruction::CALLDATASIZE;
else
*m_context << _sourceType.getOffset() << eth::Instruction::CALLDATASIZE << eth::Instruction::SUB;
*m_context << eth::Instruction::DUP1 << eth::Instruction::DUP5 << eth::Instruction::SSTORE;
// jump to end if length is zero
*m_context << eth::Instruction::ISZERO;
eth::AssemblyItem loopEnd = m_context->newTag();
m_context->appendConditionalJumpTo(loopEnd);
// actual array data is stored at SHA3(storage_offset)
*m_context << eth::Instruction::DUP3;
CompilerUtils(*m_context).computeHashStatic();
*m_context << _sourceType.getOffset();
// stack now: target_ref 32 1 target_data_ref calldata_offset
eth::AssemblyItem loopStart = m_context->newTag();
*m_context << loopStart
// copy from calldata and store
<< eth::Instruction::DUP1 << eth::Instruction::CALLDATALOAD
<< eth::Instruction::DUP3 << eth::Instruction::SSTORE
// increment target_data_ref by 1
<< eth::Instruction::SWAP1 << eth::Instruction::DUP3 << eth::Instruction::ADD
// increment calldata_offset by 32
<< eth::Instruction::SWAP1 << eth::Instruction::DUP4 << eth::Instruction::ADD
// check for loop condition
<< eth::Instruction::DUP1 << eth::Instruction::CALLDATASIZE << eth::Instruction::GT;
m_context->appendConditionalJumpTo(loopStart);
*m_context << eth::Instruction::POP << eth::Instruction::POP;
*m_context << loopEnd << eth::Instruction::POP << eth::Instruction::POP;
break;
}
case ByteArrayType::Location::Storage:
{
// this copies source to target and also clears target if it was larger
// stack: source_ref target_ref
// fetch lengthes
*m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD << eth::Instruction::SWAP2
<< eth::Instruction::DUP1 << eth::Instruction::SLOAD;
// stack: target_len_bytes target_ref source_ref source_len_bytes
// store new target length
*m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::SSTORE;
// compute hashes (data positions)
*m_context << eth::Instruction::SWAP2;
CompilerUtils(*m_context).computeHashStatic();
*m_context << eth::Instruction::SWAP1;
CompilerUtils(*m_context).computeHashStatic();
// stack: target_len_bytes source_len_bytes target_data_pos source_data_pos
// convert lengthes from bytes to storage slots
*m_context << u256(31) << u256(32) << eth::Instruction::DUP1 << eth::Instruction::DUP3
<< eth::Instruction::DUP8 << eth::Instruction::ADD << eth::Instruction::DIV
<< eth::Instruction::SWAP2
<< eth::Instruction::DUP6 << eth::Instruction::ADD << eth::Instruction::DIV;
// stack: target_len_bytes source_len_bytes target_data_pos source_data_pos target_len source_len
// @todo we might be able to go without a third counter
*m_context << u256(0);
// stack: target_len_bytes source_len_bytes target_data_pos source_data_pos target_len source_len counter
eth::AssemblyItem copyLoopStart = m_context->newTag();
*m_context << copyLoopStart;
// check for loop condition
*m_context << eth::Instruction::DUP1 << eth::Instruction::DUP3
<< eth::Instruction::GT << eth::Instruction::ISZERO;
eth::AssemblyItem copyLoopEnd = m_context->newTag();
m_context->appendConditionalJumpTo(copyLoopEnd);
// copy
*m_context << eth::Instruction::DUP4 << eth::Instruction::DUP2 << eth::Instruction::ADD
<< eth::Instruction::SLOAD
<< eth::Instruction::DUP6 << eth::Instruction::DUP3 << eth::Instruction::ADD
<< eth::Instruction::SSTORE;
// increment
*m_context << u256(1) << eth::Instruction::ADD;
m_context->appendJumpTo(copyLoopStart);
*m_context << copyLoopEnd;
// zero-out leftovers in target
eth::AssemblyItem zeroLoopStart = m_context->newTag();
*m_context << zeroLoopStart;
// check for loop condition
*m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4
<< eth::Instruction::GT << eth::Instruction::ISZERO;
eth::AssemblyItem zeroLoopEnd = m_context->newTag();
m_context->appendConditionalJumpTo(zeroLoopEnd);
// zero out
*m_context << u256(0)
<< eth::Instruction::DUP6 << eth::Instruction::DUP3 << eth::Instruction::ADD
<< eth::Instruction::SSTORE;
// increment
*m_context << u256(1) << eth::Instruction::ADD;
m_context->appendJumpTo(zeroLoopStart);
// cleanup
*m_context << zeroLoopEnd;
*m_context << eth::Instruction::POP << eth::Instruction::POP << eth::Instruction::POP
<< eth::Instruction::POP << eth::Instruction::POP << eth::Instruction::POP;
break;
}
default:
solAssert(false, "Given byte array location not implemented.");
}
}
} }
} }

2
ExpressionCompiler.h
View File

@ -149,7 +149,7 @@ private:
void storeValue(Expression const& _expression, Type const& _sourceType, bool _move = false) const; void storeValue(Expression const& _expression, Type const& _sourceType, bool _move = false) const;
/// Stores zero in the lvalue. /// Stores zero in the lvalue.
/// @a _expression is the current expression, used for error reporting. /// @a _expression is the current expression, used for error reporting.
void setToZero(Expression const& _expression) const; void setToZero(Expression const& _expression, Type const& _type) const;
/// Convenience function to convert the stored reference to a value and reset type to NONE if /// Convenience function to convert the stored reference to a value and reset type to NONE if
/// the reference was not requested by @a _expression. /// the reference was not requested by @a _expression.
void retrieveValueIfLValueNotRequested(Expression const& _expression); void retrieveValueIfLValueNotRequested(Expression const& _expression);