aboutsummaryrefslogtreecommitdiffstats
path: root/libsolidity/codegen/LValue.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'libsolidity/codegen/LValue.cpp')
-rw-r--r--libsolidity/codegen/LValue.cpp546
1 files changed, 546 insertions, 0 deletions
diff --git a/libsolidity/codegen/LValue.cpp b/libsolidity/codegen/LValue.cpp
new file mode 100644
index 00000000..574d42f8
--- /dev/null
+++ b/libsolidity/codegen/LValue.cpp
@@ -0,0 +1,546 @@
+/*
+ This file is part of cpp-ethereum.
+
+ cpp-ethereum 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.
+
+ cpp-ethereum 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 cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @author Christian <c@ethdev.com>
+ * @date 2015
+ * LValues for use in the expresison compiler.
+ */
+
+#include <libsolidity/codegen/LValue.h>
+#include <libevmcore/Instruction.h>
+#include <libsolidity/ast/Types.h>
+#include <libsolidity/ast/AST.h>
+#include <libsolidity/codegen/CompilerUtils.h>
+
+using namespace std;
+using namespace dev;
+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 << eth::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 << eth::swapInstruction(stackDiff) << eth::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 << eth::Instruction::DUP1;
+ CompilerUtils(m_context).loadFromMemoryDynamic(*m_dataType, false, m_padded, false);
+ }
+ else
+ m_context << eth::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(2, m_dataType->sizeOnStack());
+ }
+ utils.storeInMemoryDynamic(*m_dataType, m_padded);
+ m_context << eth::Instruction::POP;
+ }
+ else
+ {
+ solAssert(_sourceType == *m_dataType, "Conversion not implemented for assignment to memory.");
+
+ solAssert(m_dataType->sizeOnStack() == 1, "");
+ if (!_move)
+ m_context << eth::Instruction::DUP2 << eth::Instruction::SWAP1;
+ // stack: [value] value lvalue
+ // only store the reference
+ m_context << eth::Instruction::MSTORE;
+ }
+}
+
+void MemoryItem::setToZero(SourceLocation const&, bool _removeReference) const
+{
+ CompilerUtils utils(m_context);
+ if (!_removeReference)
+ m_context << eth::Instruction::DUP1;
+ utils.pushZeroValue(*m_dataType);
+ utils.storeInMemoryDynamic(*m_dataType, m_padded);
+ m_context << eth::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())
+ {
+ 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 << eth::Instruction::POP; // remove byte offset
+ else
+ m_context << eth::Instruction::DUP2;
+ return;
+ }
+ if (!_remove)
+ CompilerUtils(m_context).copyToStackTop(sizeOnStack(), sizeOnStack());
+ if (m_dataType->storageBytes() == 32)
+ m_context << eth::Instruction::POP << eth::Instruction::SLOAD;
+ else
+ {
+ m_context
+ << eth::Instruction::SWAP1 << eth::Instruction::SLOAD << eth::Instruction::SWAP1
+ << u256(0x100) << eth::Instruction::EXP << eth::Instruction::SWAP1 << eth::Instruction::DIV;
+ if (m_dataType->category() == Type::Category::FixedBytes)
+ m_context << (u256(0x1) << (256 - 8 * m_dataType->storageBytes())) << eth::Instruction::MUL;
+ else if (
+ m_dataType->category() == Type::Category::Integer &&
+ dynamic_cast<IntegerType const&>(*m_dataType).isSigned()
+ )
+ m_context << u256(m_dataType->storageBytes() - 1) << eth::Instruction::SIGNEXTEND;
+ else
+ m_context << ((u256(0x1) << (8 * m_dataType->storageBytes())) - 1) << eth::Instruction::AND;
+ }
+}
+
+void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _location, bool _move) const
+{
+ CompilerUtils utils(m_context);
+ // 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)
+ {
+ // offset should be zero
+ m_context << eth::Instruction::POP;
+ if (!_move)
+ m_context << eth::Instruction::DUP2 << eth::Instruction::SWAP1;
+ m_context << eth::Instruction::SSTORE;
+ }
+ else
+ {
+ // OR the value into the other values in the storage slot
+ m_context << u256(0x100) << eth::Instruction::EXP;
+ // stack: value storage_ref multiplier
+ // fetch old value
+ m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
+ // stack: value storege_ref multiplier old_full_value
+ // clear bytes in old value
+ m_context
+ << eth::Instruction::DUP2 << ((u256(1) << (8 * m_dataType->storageBytes())) - 1)
+ << eth::Instruction::MUL;
+ m_context << eth::Instruction::NOT << eth::Instruction::AND;
+ // stack: value storage_ref multiplier cleared_value
+ m_context
+ << eth::Instruction::SWAP1 << eth::Instruction::DUP4;
+ // stack: value storage_ref cleared_value multiplier value
+ if (m_dataType->category() == Type::Category::FixedBytes)
+ m_context
+ << (u256(0x1) << (256 - 8 * dynamic_cast<FixedBytesType const&>(*m_dataType).numBytes()))
+ << eth::Instruction::SWAP1 << eth::Instruction::DIV;
+ else if (
+ m_dataType->category() == Type::Category::Integer &&
+ dynamic_cast<IntegerType const&>(*m_dataType).isSigned()
+ )
+ // remove the higher order bits
+ m_context
+ << (u256(1) << (8 * (32 - m_dataType->storageBytes())))
+ << eth::Instruction::SWAP1
+ << eth::Instruction::DUP2
+ << eth::Instruction::MUL
+ << eth::Instruction::DIV;
+ m_context << eth::Instruction::MUL << eth::Instruction::OR;
+ // stack: value storage_ref updated_value
+ m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
+ if (_move)
+ m_context << eth::Instruction::POP;
+ }
+ }
+ else
+ {
+ solAssert(
+ _sourceType.category() == m_dataType->category(),
+ "Wrong type conversation for assignment.");
+ if (m_dataType->category() == Type::Category::Array)
+ {
+ m_context << eth::Instruction::POP; // remove byte offset
+ ArrayUtils(m_context).copyArrayToStorage(
+ dynamic_cast<ArrayType const&>(*m_dataType),
+ dynamic_cast<ArrayType const&>(_sourceType)
+ );
+ if (_move)
+ m_context << eth::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 << eth::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())
+ {
+ // 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 << eth::Instruction::DUP3 << eth::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 << eth::Instruction::DUP3 << eth::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 << eth::dupInstruction(1 + stackSize) << offsets.first << eth::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 << eth::Instruction::SWAP1 << eth::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())
+ {
+ // 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 << eth::Instruction::DUP3 << eth::Instruction::ADD
+ << u256(offsets.second);
+ StorageItem(m_context, *memberType).setToZero();
+ }
+ if (_removeReference)
+ m_context << eth::Instruction::POP << eth::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
+ << eth::Instruction::POP << u256(0)
+ << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
+ }
+ else
+ {
+ m_context << u256(0x100) << eth::Instruction::EXP;
+ // stack: storage_ref multiplier
+ // fetch old value
+ m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
+ // stack: storege_ref multiplier old_full_value
+ // clear bytes in old value
+ m_context
+ << eth::Instruction::SWAP1 << ((u256(1) << (8 * m_dataType->storageBytes())) - 1)
+ << eth::Instruction::MUL;
+ m_context << eth::Instruction::NOT << eth::Instruction::AND;
+ // stack: storage_ref cleared_value
+ m_context << eth::Instruction::SWAP1 << eth::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 << eth::Instruction::SWAP1 << eth::Instruction::SLOAD
+ << eth::Instruction::SWAP1 << eth::Instruction::BYTE;
+ else
+ m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD
+ << eth::Instruction::DUP2 << eth::Instruction::BYTE;
+ m_context << (u256(1) << (256 - 8)) << eth::Instruction::MUL;
+}
+
+void StorageByteArrayElement::storeValue(Type const&, SourceLocation const&, bool _move) const
+{
+ // stack: value ref byte_number
+ m_context << u256(31) << eth::Instruction::SUB << u256(0x100) << eth::Instruction::EXP;
+ // stack: value ref (1<<(8*(31-byte_number)))
+ m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
+ // stack: value ref (1<<(8*(31-byte_number))) old_full_value
+ // clear byte in old value
+ m_context << eth::Instruction::DUP2 << u256(0xff) << eth::Instruction::MUL
+ << eth::Instruction::NOT << eth::Instruction::AND;
+ // stack: value ref (1<<(32-byte_number)) old_full_value_with_cleared_byte
+ m_context << eth::Instruction::SWAP1;
+ m_context << (u256(1) << (256 - 8)) << eth::Instruction::DUP5 << eth::Instruction::DIV
+ << eth::Instruction::MUL << eth::Instruction::OR;
+ // stack: value ref new_full_value
+ m_context << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
+ if (_move)
+ m_context << eth::Instruction::POP;
+}
+
+void StorageByteArrayElement::setToZero(SourceLocation const&, bool _removeReference) const
+{
+ // stack: ref byte_number
+ if (!_removeReference)
+ m_context << eth::Instruction::DUP2 << eth::Instruction::DUP2;
+ m_context << u256(31) << eth::Instruction::SUB << u256(0x100) << eth::Instruction::EXP;
+ // stack: ref (1<<(8*(31-byte_number)))
+ m_context << eth::Instruction::DUP2 << eth::Instruction::SLOAD;
+ // stack: ref (1<<(8*(31-byte_number))) old_full_value
+ // clear byte in old value
+ m_context << eth::Instruction::SWAP1 << u256(0xff) << eth::Instruction::MUL;
+ m_context << eth::Instruction::NOT << eth::Instruction::AND;
+ // stack: ref old_full_value_with_cleared_byte
+ m_context << eth::Instruction::SWAP1 << eth::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 << eth::Instruction::SWAP1 << eth::Instruction::POP;
+}
+
+void StorageArrayLength::storeValue(Type const&, SourceLocation const&, bool _move) const
+{
+ if (_move)
+ m_context << eth::Instruction::SWAP1;
+ else
+ m_context << eth::Instruction::DUP2;
+ ArrayUtils(m_context).resizeDynamicArray(m_arrayType);
+}
+
+void StorageArrayLength::setToZero(SourceLocation const&, bool _removeReference) const
+{
+ if (!_removeReference)
+ m_context << eth::Instruction::DUP1;
+ 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& _location, bool _remove) const
+{
+ unsigned initialDepth = sizeOnStack();
+ unsigned initialStack = m_context.stackHeight();
+ for (auto const& lv: m_lvalues)
+ if (lv)
+ {
+ solAssert(initialDepth + m_context.stackHeight() >= initialStack, "");
+ unsigned depth = initialDepth + m_context.stackHeight() - initialStack;
+ if (lv->sizeOnStack() > 0)
+ {
+ if (_remove && depth > lv->sizeOnStack())
+ CompilerUtils(m_context).moveToStackTop(depth, depth - lv->sizeOnStack());
+ else if (!_remove && depth > 0)
+ CompilerUtils(m_context).copyToStackTop(depth, lv->sizeOnStack());
+ }
+ lv->retrieveValue(_location, true);
+ }
+}
+
+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& _location, bool _removeReference) const
+{
+ if (_removeReference)
+ {
+ for (size_t i = 0; i < m_lvalues.size(); ++i)
+ if (m_lvalues[m_lvalues.size() - i])
+ m_lvalues[m_lvalues.size() - i]->setToZero(_location, true);
+ }
+ else
+ {
+ unsigned depth = sizeOnStack();
+ for (auto const& val: m_lvalues)
+ if (val)
+ {
+ if (val->sizeOnStack() > 0)
+ CompilerUtils(m_context).copyToStackTop(depth, val->sizeOnStack());
+ val->setToZero(_location, false);
+ depth -= val->sizeOnStack();
+ }
+ }
+}