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Helper functions to access memory.

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This commit is contained in:
Christian 2014-12-10 17:15:17 +01:00
parent 130ff85e85
commit 373f0da267
4 changed files with 61 additions and 34 deletions
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17
Compiler.cpp
View File

@ -130,7 +130,6 @@ unsigned Compiler::appendCalldataUnpacker(FunctionDefinition const& _function, b
{
// We do not check the calldata size, everything is zero-padded.
unsigned dataOffset = 1;
eth::Instruction load = _fromMemory ? eth::Instruction::MLOAD : eth::Instruction::CALLDATALOAD;
//@todo this can be done more efficiently, saving some CALLDATALOAD calls
for (ASTPointer<VariableDeclaration> const& var: _function.getParameters())
@ -140,14 +139,8 @@ unsigned Compiler::appendCalldataUnpacker(FunctionDefinition const& _function, b
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_sourceLocation(var->getLocation())
<< errinfo_comment("Type " + var->getType()->toString() + " not yet supported."));
if (numBytes == 32)
m_context << u256(dataOffset) << load;
else if (var->getType()->getCategory() == Type::Category::STRING)
m_context << (u256(1) << ((32 - numBytes) * 8)) << eth::Instruction::DUP1
<< u256(dataOffset) << load << eth::Instruction::DIV << eth::Instruction::MUL;
else
m_context << (u256(1) << ((32 - numBytes) * 8)) << u256(dataOffset)
<< load << eth::Instruction::DIV;
bool leftAligned = var->getType()->getCategory() == Type::Category::STRING;
CompilerUtils(m_context).loadFromMemory(dataOffset, numBytes, leftAligned, !_fromMemory);
dataOffset += numBytes;
}
return dataOffset;
@ -168,10 +161,8 @@ void Compiler::appendReturnValuePacker(FunctionDefinition const& _function)
<< errinfo_sourceLocation(parameters[i]->getLocation())
<< errinfo_comment("Type " + paramType.toString() + " not yet supported."));
CompilerUtils(m_context).copyToStackTop(stackDepth, paramType);
if (numBytes != 32)
if (paramType.getCategory() != Type::Category::STRING)
m_context << (u256(1) << ((32 - numBytes) * 8)) << eth::Instruction::MUL;
m_context << u256(dataOffset) << eth::Instruction::MSTORE;
bool const leftAligned = paramType.getCategory() == Type::Category::STRING;
CompilerUtils(m_context).storeInMemory(dataOffset, numBytes, leftAligned);
stackDepth -= paramType.getSizeOnStack();
dataOffset += numBytes;
}

30
CompilerUtils.cpp
View File

@ -31,6 +31,36 @@ namespace dev
namespace solidity
{
void CompilerUtils::loadFromMemory(unsigned _offset, unsigned _bytes, bool _leftAligned, bool _fromCalldata)
{
eth::Instruction load = _fromCalldata ? eth::Instruction::CALLDATALOAD : eth::Instruction::MLOAD;
if (asserts(0 < _bytes && _bytes <= 32))
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Memory load of 0 or more than 32 bytes requested."));
if (_bytes == 32)
m_context << u256(_offset) << load;
else
{
// load data and add leading or trailing zeros by dividing/multiplying depending on alignment
u256 shiftFactor = u256(1) << ((32 - _bytes) * 8);
m_context << shiftFactor;
if (_leftAligned)
m_context << eth::Instruction::DUP1;
m_context << u256(_offset) << load << eth::Instruction::DIV;
if (_leftAligned)
m_context << eth::Instruction::MUL;
}
}
void CompilerUtils::storeInMemory(unsigned _offset, unsigned _bytes, bool _leftAligned)
{
if (asserts(0 < _bytes && _bytes <= 32))
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Memory store of 0 or more than 32 bytes requested."));
if (_bytes != 32 && !_leftAligned)
// shift the value accordingly before storing
m_context << (u256(1) << ((32 - _bytes) * 8)) << eth::Instruction::MUL;
m_context << u256(_offset) << eth::Instruction::MSTORE;
}
void CompilerUtils::moveToStackVariable(VariableDeclaration const& _variable)
{
unsigned const stackPosition = m_context.baseToCurrentStackOffset(m_context.getBaseStackOffsetOfVariable(_variable));

12
CompilerUtils.h
View File

@ -35,6 +35,18 @@ class CompilerUtils
public:
CompilerUtils(CompilerContext& _context): m_context(_context) {}
/// Loads data from memory to the stack.
/// @param _offset offset in memory (or calldata)
/// @param _bytes number of bytes to load
/// @param _leftAligned if true, store left aligned on stack (otherwise right aligned)
/// @param _fromCalldata if true, load from calldata, not from memory
void loadFromMemory(unsigned _offset, unsigned _bytes = 32, bool _leftAligned = false, bool _fromCalldata = false);
/// Stores data from stack in memory.
/// @param _offset offset in memory
/// @param _bytes number of bytes to store
/// @param _leftAligned if true, data is left aligned on stack (otherwise right aligned)
void storeInMemory(unsigned _offset, unsigned _bytes = 32, bool _leftAligned = false);
/// Moves the value that is at the top of the stack to a stack variable.
void moveToStackVariable(VariableDeclaration const& _variable);
/// Copies a variable of type @a _type from a stack depth of @a _stackDepth to the top of the stack.

36
ExpressionCompiler.cpp
View File

@ -225,15 +225,14 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall)
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_sourceLocation(arguments[i]->getLocation())
<< errinfo_comment("Type " + type.toString() + " not yet supported."));
if (numBytes != 32)
if (type.getCategory() != Type::Category::STRING)
m_context << (u256(1) << ((32 - numBytes) * 8)) << eth::Instruction::MUL;
m_context << u256(dataOffset) << eth::Instruction::MSTORE;
bool const leftAligned = type.getCategory() == Type::Category::STRING;
CompilerUtils(m_context).storeInMemory(dataOffset, numBytes, leftAligned);
dataOffset += numBytes;
}
//@todo only return the first return value for now
unsigned retSize = function.getReturnParameterTypes().empty() ? 0
: function.getReturnParameterTypes().front()->getCalldataEncodedSize();
Type const* firstType = function.getReturnParameterTypes().empty() ? nullptr :
function.getReturnParameterTypes().front().get();
unsigned retSize = firstType ? firstType->getCalldataEncodedSize() : 0;
// CALL arguments: outSize, outOff, inSize, inOff, value, addr, gas (stack top)
m_context << u256(retSize) << u256(0) << u256(dataOffset) << u256(0) << u256(0);
_functionCall.getExpression().accept(*this); // pushes addr and function index
@ -241,17 +240,10 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall)
<< u256(25) << eth::Instruction::GAS << eth::Instruction::SUB
<< eth::Instruction::CALL
<< eth::Instruction::POP; // @todo do not ignore failure indicator
if (retSize == 32)
m_context << u256(0) << eth::Instruction::MLOAD;
else if (retSize > 0)
if (retSize > 0)
{
if (function.getReturnParameterTypes().front()->getCategory() == Type::Category::STRING)
m_context << (u256(1) << ((32 - retSize) * 8)) << eth::Instruction::DUP1
<< u256(0) << eth::Instruction::MLOAD
<< eth::Instruction::DIV << eth::Instruction::MUL;
else
m_context << (u256(1) << ((32 - retSize) * 8))
<< u256(0) << eth::Instruction::MLOAD << eth::Instruction::DIV;
bool const leftAligned = firstType->getCategory() == Type::Category::STRING;
CompilerUtils(m_context).loadFromMemory(0, retSize, leftAligned);
}
break;
}
@ -275,7 +267,8 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall)
arguments.front()->accept(*this);
appendTypeConversion(*arguments.front()->getType(), *function.getParameterTypes().front(), true);
// @todo move this once we actually use memory
m_context << u256(0) << eth::Instruction::MSTORE << u256(32) << u256(0) << eth::Instruction::SHA3;
CompilerUtils(m_context).storeInMemory(0);
m_context << u256(32) << u256(0) << eth::Instruction::SHA3;
break;
case Location::ECRECOVER:
case Location::SHA256:
@ -291,13 +284,13 @@ bool ExpressionCompiler::visit(FunctionCall& _functionCall)
arguments[i]->accept(*this);
appendTypeConversion(*arguments[i]->getType(), *function.getParameterTypes()[i], true);
// @todo move this once we actually use memory
m_context << u256(i * 32) << eth::Instruction::MSTORE;
CompilerUtils(m_context).storeInMemory(i * 32);
}
m_context << u256(32) << u256(0) << u256(arguments.size() * 32) << u256(0) << u256(0)
<< contractAddress << u256(500) //@todo determine actual gas requirement
<< eth::Instruction::CALL
<< eth::Instruction::POP
<< u256(0) << eth::Instruction::MLOAD;
<< eth::Instruction::POP;
CompilerUtils(m_context).loadFromMemory(0);
break;
}
default:
@ -381,7 +374,8 @@ bool ExpressionCompiler::visit(IndexAccess& _indexAccess)
*dynamic_cast<MappingType const&>(*_indexAccess.getBaseExpression().getType()).getKeyType(),
true);
// @todo move this once we actually use memory
m_context << u256(32) << eth::Instruction::MSTORE << u256(0) << eth::Instruction::MSTORE;
CompilerUtils(m_context).storeInMemory(0);
CompilerUtils(m_context).storeInMemory(32);
m_context << u256(64) << u256(0) << eth::Instruction::SHA3;
m_currentLValue = LValue(m_context, LValue::STORAGE, *_indexAccess.getType());