solidity/libsolidity/codegen/LValue.cpp
2018-12-17 17:06:11 +01:00

560 lines
19 KiB
C++

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2015
* LValues for use in the expression compiler.
*/
#include <libsolidity/codegen/LValue.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/ast/Types.h>
#include <libsolidity/codegen/CompilerUtils.h>
#include <libevmasm/Instruction.h>
using namespace std;
using namespace dev;
using namespace langutil;
using namespace solidity;
StackVariable::StackVariable(CompilerContext& _compilerContext, VariableDeclaration const& _declaration):
LValue(_compilerContext, _declaration.annotation().type.get()),
m_baseStackOffset(m_context.baseStackOffsetOfVariable(_declaration)),
m_size(m_dataType->sizeOnStack())
{
}
void StackVariable::retrieveValue(SourceLocation const& _location, bool) const
{
unsigned stackPos = m_context.baseToCurrentStackOffset(m_baseStackOffset);
if (stackPos + 1 > 16) //@todo correct this by fetching earlier or moving to memory
BOOST_THROW_EXCEPTION(
CompilerError() <<
errinfo_sourceLocation(_location) <<
errinfo_comment("Stack too deep, try removing local variables.")
);
solAssert(stackPos + 1 >= m_size, "Size and stack pos mismatch.");
for (unsigned i = 0; i < m_size; ++i)
m_context << dupInstruction(stackPos + 1);
}
void StackVariable::storeValue(Type const&, SourceLocation const& _location, bool _move) const
{
unsigned stackDiff = m_context.baseToCurrentStackOffset(m_baseStackOffset) - m_size + 1;
if (stackDiff > 16)
BOOST_THROW_EXCEPTION(
CompilerError() <<
errinfo_sourceLocation(_location) <<
errinfo_comment("Stack too deep, try removing local variables.")
);
else if (stackDiff > 0)
for (unsigned i = 0; i < m_size; ++i)
m_context << swapInstruction(stackDiff) << Instruction::POP;
if (!_move)
retrieveValue(_location);
}
void StackVariable::setToZero(SourceLocation const& _location, bool) const
{
CompilerUtils(m_context).pushZeroValue(*m_dataType);
storeValue(*m_dataType, _location, true);
}
MemoryItem::MemoryItem(CompilerContext& _compilerContext, Type const& _type, bool _padded):
LValue(_compilerContext, &_type),
m_padded(_padded)
{
}
void MemoryItem::retrieveValue(SourceLocation const&, bool _remove) const
{
if (m_dataType->isValueType())
{
if (!_remove)
m_context << Instruction::DUP1;
CompilerUtils(m_context).loadFromMemoryDynamic(*m_dataType, false, m_padded, false);
}
else
m_context << Instruction::MLOAD;
}
void MemoryItem::storeValue(Type const& _sourceType, SourceLocation const&, bool _move) const
{
CompilerUtils utils(m_context);
if (m_dataType->isValueType())
{
solAssert(_sourceType.isValueType(), "");
utils.moveIntoStack(_sourceType.sizeOnStack());
utils.convertType(_sourceType, *m_dataType, true);
if (!_move)
{
utils.moveToStackTop(m_dataType->sizeOnStack());
utils.copyToStackTop(1 + m_dataType->sizeOnStack(), m_dataType->sizeOnStack());
}
if (!m_padded)
{
solAssert(m_dataType->calldataEncodedSize(false) == 1, "Invalid non-padded type.");
if (m_dataType->category() == Type::Category::FixedBytes)
m_context << u256(0) << Instruction::BYTE;
m_context << Instruction::SWAP1 << Instruction::MSTORE8;
}
else
{
utils.storeInMemoryDynamic(*m_dataType, m_padded);
m_context << Instruction::POP;
}
}
else
{
solUnimplementedAssert(_sourceType == *m_dataType, "Conversion not implemented for assignment to memory.");
solAssert(m_dataType->sizeOnStack() == 1, "");
if (!_move)
m_context << Instruction::DUP2 << Instruction::SWAP1;
// stack: [value] value lvalue
// only store the reference
m_context << Instruction::MSTORE;
}
}
void MemoryItem::setToZero(SourceLocation const&, bool _removeReference) const
{
CompilerUtils utils(m_context);
solAssert(_removeReference, "");
utils.pushZeroValue(*m_dataType);
utils.storeInMemoryDynamic(*m_dataType, m_padded);
m_context << Instruction::POP;
}
StorageItem::StorageItem(CompilerContext& _compilerContext, VariableDeclaration const& _declaration):
StorageItem(_compilerContext, *_declaration.annotation().type)
{
auto const& location = m_context.storageLocationOfVariable(_declaration);
m_context << location.first << u256(location.second);
}
StorageItem::StorageItem(CompilerContext& _compilerContext, Type const& _type):
LValue(_compilerContext, &_type)
{
if (m_dataType->isValueType())
{
if (m_dataType->category() != Type::Category::Function)
solAssert(m_dataType->storageSize() == m_dataType->sizeOnStack(), "");
solAssert(m_dataType->storageSize() == 1, "Invalid storage size.");
}
}
void StorageItem::retrieveValue(SourceLocation const&, bool _remove) const
{
// stack: storage_key storage_offset
if (!m_dataType->isValueType())
{
solAssert(m_dataType->sizeOnStack() == 1, "Invalid storage ref size.");
if (_remove)
m_context << Instruction::POP; // remove byte offset
else
m_context << Instruction::DUP2;
return;
}
if (!_remove)
CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
if (m_dataType->storageBytes() == 32)
m_context << Instruction::POP << Instruction::SLOAD;
else
{
bool cleaned = false;
m_context
<< Instruction::SWAP1 << Instruction::SLOAD << Instruction::SWAP1
<< u256(0x100) << Instruction::EXP << Instruction::SWAP1 << Instruction::DIV;
if (m_dataType->category() == Type::Category::FixedPoint)
// implementation should be very similar to the integer case.
solUnimplemented("Not yet implemented - FixedPointType.");
if (m_dataType->category() == Type::Category::FixedBytes)
{
CompilerUtils(m_context).leftShiftNumberOnStack(256 - 8 * m_dataType->storageBytes());
cleaned = true;
}
else if (
m_dataType->category() == Type::Category::Integer &&
dynamic_cast<IntegerType const&>(*m_dataType).isSigned()
)
{
m_context << u256(m_dataType->storageBytes() - 1) << Instruction::SIGNEXTEND;
cleaned = true;
}
else if (FunctionType const* fun = dynamic_cast<decltype(fun)>(m_dataType))
{
if (fun->kind() == FunctionType::Kind::External)
{
CompilerUtils(m_context).splitExternalFunctionType(false);
cleaned = true;
}
}
if (!cleaned)
{
solAssert(m_dataType->sizeOnStack() == 1, "");
m_context << ((u256(0x1) << (8 * m_dataType->storageBytes())) - 1) << Instruction::AND;
}
}
}
void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _location, bool _move) const
{
CompilerUtils utils(m_context);
solAssert(m_dataType, "");
// stack: value storage_key storage_offset
if (m_dataType->isValueType())
{
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.");
// offset should be zero
m_context << Instruction::POP;
if (!_move)
m_context << Instruction::DUP2 << Instruction::SWAP1;
m_context << Instruction::SWAP1;
utils.convertType(_sourceType, *m_dataType, true);
m_context << Instruction::SWAP1;
m_context << Instruction::SSTORE;
}
else
{
// OR the value into the other values in the storage slot
m_context << u256(0x100) << Instruction::EXP;
// stack: value storage_ref multiplier
// fetch old value
m_context << Instruction::DUP2 << Instruction::SLOAD;
// stack: value storege_ref multiplier old_full_value
// clear bytes in old value
m_context
<< Instruction::DUP2 << ((u256(1) << (8 * m_dataType->storageBytes())) - 1)
<< Instruction::MUL;
m_context << Instruction::NOT << Instruction::AND << Instruction::SWAP1;
// stack: value storage_ref cleared_value multiplier
utils.copyToStackTop(3 + m_dataType->sizeOnStack(), m_dataType->sizeOnStack());
// stack: value storage_ref cleared_value multiplier value
if (FunctionType const* fun = dynamic_cast<decltype(fun)>(m_dataType))
{
solAssert(_sourceType == *m_dataType, "function item stored but target is not equal to source");
if (fun->kind() == FunctionType::Kind::External)
// Combine the two-item function type into a single stack slot.
utils.combineExternalFunctionType(false);
else
m_context <<
((u256(1) << (8 * m_dataType->storageBytes())) - 1) <<
Instruction::AND;
}
else if (m_dataType->category() == Type::Category::FixedBytes)
{
solAssert(_sourceType.category() == Type::Category::FixedBytes, "source not fixed bytes");
CompilerUtils(m_context).rightShiftNumberOnStack(256 - 8 * dynamic_cast<FixedBytesType const&>(*m_dataType).numBytes());
}
else
{
solAssert(m_dataType->sizeOnStack() == 1, "Invalid stack size for opaque type.");
// remove the higher order bits
utils.convertType(_sourceType, *m_dataType, true, true);
}
m_context << Instruction::MUL << Instruction::OR;
// stack: value storage_ref updated_value
m_context << Instruction::SWAP1 << Instruction::SSTORE;
if (_move)
utils.popStackElement(*m_dataType);
}
}
else
{
solAssert(
_sourceType.category() == m_dataType->category(),
"Wrong type conversation for assignment.");
if (m_dataType->category() == Type::Category::Array)
{
m_context << Instruction::POP; // remove byte offset
ArrayUtils(m_context).copyArrayToStorage(
dynamic_cast<ArrayType const&>(*m_dataType),
dynamic_cast<ArrayType const&>(_sourceType)
);
if (_move)
m_context << Instruction::POP;
}
else if (m_dataType->category() == Type::Category::Struct)
{
// stack layout: source_ref target_ref target_offset
// note that we have structs, so offset should be zero and are ignored
m_context << Instruction::POP;
auto const& structType = dynamic_cast<StructType const&>(*m_dataType);
auto const& sourceType = dynamic_cast<StructType const&>(_sourceType);
solAssert(
structType.structDefinition() == sourceType.structDefinition(),
"Struct assignment with conversion."
);
solAssert(sourceType.location() != DataLocation::CallData, "Structs in calldata not supported.");
for (auto const& member: structType.members(nullptr))
{
// assign each member that is not a mapping
TypePointer const& memberType = member.type;
if (memberType->category() == Type::Category::Mapping)
continue;
TypePointer sourceMemberType = sourceType.memberType(member.name);
if (sourceType.location() == DataLocation::Storage)
{
// stack layout: source_ref target_ref
pair<u256, unsigned> const& offsets = sourceType.storageOffsetsOfMember(member.name);
m_context << offsets.first << Instruction::DUP3 << Instruction::ADD;
m_context << u256(offsets.second);
// stack: source_ref target_ref source_member_ref source_member_off
StorageItem(m_context, *sourceMemberType).retrieveValue(_location, true);
// stack: source_ref target_ref source_value...
}
else
{
solAssert(sourceType.location() == DataLocation::Memory, "");
// stack layout: source_ref target_ref
TypePointer sourceMemberType = sourceType.memberType(member.name);
m_context << sourceType.memoryOffsetOfMember(member.name);
m_context << Instruction::DUP3 << Instruction::ADD;
MemoryItem(m_context, *sourceMemberType).retrieveValue(_location, true);
// stack layout: source_ref target_ref source_value...
}
unsigned stackSize = sourceMemberType->sizeOnStack();
pair<u256, unsigned> const& offsets = structType.storageOffsetsOfMember(member.name);
m_context << dupInstruction(1 + stackSize) << offsets.first << Instruction::ADD;
m_context << u256(offsets.second);
// stack: source_ref target_ref target_off source_value... target_member_ref target_member_byte_off
StorageItem(m_context, *memberType).storeValue(*sourceMemberType, _location, true);
}
// stack layout: source_ref target_ref
solAssert(sourceType.sizeOnStack() == 1, "Unexpected source size.");
if (_move)
utils.popStackSlots(2);
else
m_context << Instruction::SWAP1 << Instruction::POP;
}
else
BOOST_THROW_EXCEPTION(
InternalCompilerError()
<< errinfo_sourceLocation(_location)
<< errinfo_comment("Invalid non-value type for assignment."));
}
}
void StorageItem::setToZero(SourceLocation const&, bool _removeReference) const
{
if (m_dataType->category() == Type::Category::Array)
{
if (!_removeReference)
CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
ArrayUtils(m_context).clearArray(dynamic_cast<ArrayType const&>(*m_dataType));
}
else if (m_dataType->category() == Type::Category::Struct)
{
// stack layout: storage_key storage_offset
// @todo this can be improved: use StorageItem for non-value types, and just store 0 in
// all slots that contain value types later.
auto const& structType = dynamic_cast<StructType const&>(*m_dataType);
for (auto const& member: structType.members(nullptr))
{
// zero each member that is not a mapping
TypePointer const& memberType = member.type;
if (memberType->category() == Type::Category::Mapping)
continue;
pair<u256, unsigned> const& offsets = structType.storageOffsetsOfMember(member.name);
m_context
<< offsets.first << Instruction::DUP3 << Instruction::ADD
<< u256(offsets.second);
StorageItem(m_context, *memberType).setToZero();
}
if (_removeReference)
m_context << Instruction::POP << Instruction::POP;
}
else
{
solAssert(m_dataType->isValueType(), "Clearing of unsupported type requested: " + m_dataType->toString());
if (!_removeReference)
CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
if (m_dataType->storageBytes() == 32)
{
// offset should be zero
m_context
<< Instruction::POP << u256(0)
<< Instruction::SWAP1 << Instruction::SSTORE;
}
else
{
m_context << u256(0x100) << Instruction::EXP;
// stack: storage_ref multiplier
// fetch old value
m_context << Instruction::DUP2 << Instruction::SLOAD;
// stack: storege_ref multiplier old_full_value
// clear bytes in old value
m_context
<< Instruction::SWAP1 << ((u256(1) << (8 * m_dataType->storageBytes())) - 1)
<< Instruction::MUL;
m_context << Instruction::NOT << Instruction::AND;
// stack: storage_ref cleared_value
m_context << Instruction::SWAP1 << Instruction::SSTORE;
}
}
}
/// Used in StorageByteArrayElement
static FixedBytesType byteType(1);
StorageByteArrayElement::StorageByteArrayElement(CompilerContext& _compilerContext):
LValue(_compilerContext, &byteType)
{
}
void StorageByteArrayElement::retrieveValue(SourceLocation const&, bool _remove) const
{
// stack: ref byte_number
if (_remove)
m_context << Instruction::SWAP1 << Instruction::SLOAD
<< Instruction::SWAP1 << Instruction::BYTE;
else
m_context << Instruction::DUP2 << Instruction::SLOAD
<< Instruction::DUP2 << Instruction::BYTE;
m_context << (u256(1) << (256 - 8)) << Instruction::MUL;
}
void StorageByteArrayElement::storeValue(Type const&, SourceLocation const&, bool _move) const
{
// stack: value ref byte_number
m_context << u256(31) << Instruction::SUB << u256(0x100) << Instruction::EXP;
// stack: value ref (1<<(8*(31-byte_number)))
m_context << Instruction::DUP2 << Instruction::SLOAD;
// stack: value ref (1<<(8*(31-byte_number))) old_full_value
// clear byte in old value
m_context << Instruction::DUP2 << u256(0xff) << Instruction::MUL
<< Instruction::NOT << Instruction::AND;
// stack: value ref (1<<(32-byte_number)) old_full_value_with_cleared_byte
m_context << Instruction::SWAP1;
m_context << (u256(1) << (256 - 8)) << Instruction::DUP5 << Instruction::DIV
<< Instruction::MUL << Instruction::OR;
// stack: value ref new_full_value
m_context << Instruction::SWAP1 << Instruction::SSTORE;
if (_move)
m_context << Instruction::POP;
}
void StorageByteArrayElement::setToZero(SourceLocation const&, bool _removeReference) const
{
// stack: ref byte_number
solAssert(_removeReference, "");
m_context << u256(31) << Instruction::SUB << u256(0x100) << Instruction::EXP;
// stack: ref (1<<(8*(31-byte_number)))
m_context << Instruction::DUP2 << Instruction::SLOAD;
// stack: ref (1<<(8*(31-byte_number))) old_full_value
// clear byte in old value
m_context << Instruction::SWAP1 << u256(0xff) << Instruction::MUL;
m_context << Instruction::NOT << Instruction::AND;
// stack: ref old_full_value_with_cleared_byte
m_context << Instruction::SWAP1 << Instruction::SSTORE;
}
StorageArrayLength::StorageArrayLength(CompilerContext& _compilerContext, const ArrayType& _arrayType):
LValue(_compilerContext, _arrayType.memberType("length").get()),
m_arrayType(_arrayType)
{
solAssert(m_arrayType.isDynamicallySized(), "");
}
void StorageArrayLength::retrieveValue(SourceLocation const&, bool _remove) const
{
ArrayUtils(m_context).retrieveLength(m_arrayType);
if (_remove)
m_context << Instruction::SWAP1 << Instruction::POP;
}
void StorageArrayLength::storeValue(Type const&, SourceLocation const&, bool _move) const
{
if (_move)
m_context << Instruction::SWAP1;
else
m_context << Instruction::DUP2;
ArrayUtils(m_context).resizeDynamicArray(m_arrayType);
}
void StorageArrayLength::setToZero(SourceLocation const&, bool _removeReference) const
{
solAssert(_removeReference, "");
ArrayUtils(m_context).clearDynamicArray(m_arrayType);
}
TupleObject::TupleObject(
CompilerContext& _compilerContext,
std::vector<std::unique_ptr<LValue>>&& _lvalues
):
LValue(_compilerContext), m_lvalues(move(_lvalues))
{
}
unsigned TupleObject::sizeOnStack() const
{
unsigned size = 0;
for (auto const& lv: m_lvalues)
if (lv)
size += lv->sizeOnStack();
return size;
}
void TupleObject::retrieveValue(SourceLocation const&, bool) const
{
solAssert(false, "Tried to retrieve value of tuple.");
}
void TupleObject::storeValue(Type const& _sourceType, SourceLocation const& _location, bool) const
{
// values are below the lvalue references
unsigned valuePos = sizeOnStack();
TypePointers const& valueTypes = dynamic_cast<TupleType const&>(_sourceType).components();
solAssert(valueTypes.size() == m_lvalues.size(), "");
// valuePos .... refPos ...
// We will assign from right to left to optimize stack layout.
for (size_t i = 0; i < m_lvalues.size(); ++i)
{
unique_ptr<LValue> const& lvalue = m_lvalues[m_lvalues.size() - i - 1];
TypePointer const& valType = valueTypes[valueTypes.size() - i - 1];
unsigned stackHeight = m_context.stackHeight();
solAssert(!valType == !lvalue, "");
if (!lvalue)
continue;
valuePos += valType->sizeOnStack();
// copy value to top
CompilerUtils(m_context).copyToStackTop(valuePos, valType->sizeOnStack());
// move lvalue ref above value
CompilerUtils(m_context).moveToStackTop(valType->sizeOnStack(), lvalue->sizeOnStack());
lvalue->storeValue(*valType, _location, true);
valuePos += m_context.stackHeight() - stackHeight;
}
// As the type of an assignment to a tuple type is the empty tuple, we always move.
CompilerUtils(m_context).popStackElement(_sourceType);
}
void TupleObject::setToZero(SourceLocation const&, bool) const
{
solAssert(false, "Tried to delete tuple.");
}