solidity/ExpressionCompiler.h
2014-11-06 02:36:39 +01:00

90 lines
3.6 KiB
C++

/*
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 2014
* Solidity AST to EVM bytecode compiler for expressions.
*/
#include <libsolidity/ASTVisitor.h>
namespace dev {
namespace solidity {
class CompilerContext; // forward
class Type; // forward
class IntegerType; // forward
/// Compiler for expressions, i.e. converts an AST tree whose root is an Expression into a stream
/// of EVM instructions. It needs a compiler context that is the same for the whole compilation
/// unit.
class ExpressionCompiler: private ASTVisitor
{
public:
/// Compile the given @a _expression into the @a _context.
static void compileExpression(CompilerContext& _context, Expression& _expression);
/// Appends code to remove dirty higher order bits in case of an implicit promotion to a wider type.
static void appendTypeConversion(CompilerContext& _context, Type const& _typeOnStack, Type const& _targetType);
private:
ExpressionCompiler(CompilerContext& _compilerContext): m_currentLValue(nullptr), m_context(_compilerContext) {}
virtual bool visit(Assignment& _assignment) override;
virtual void endVisit(UnaryOperation& _unaryOperation) override;
virtual bool visit(BinaryOperation& _binaryOperation) override;
virtual bool visit(FunctionCall& _functionCall) override;
virtual void endVisit(MemberAccess& _memberAccess) override;
virtual void endVisit(IndexAccess& _indexAccess) override;
virtual void endVisit(Identifier& _identifier) override;
virtual void endVisit(Literal& _literal) override;
///@{
///@name Append code for various operator types
void appendAndOrOperatorCode(BinaryOperation& _binaryOperation);
void appendCompareOperatorCode(Token::Value _operator, Type const& _type);
void appendOrdinaryBinaryOperatorCode(Token::Value _operator, Type const& _type);
void appendArithmeticOperatorCode(Token::Value _operator, Type const& _type);
void appendBitOperatorCode(Token::Value _operator);
void appendShiftOperatorCode(Token::Value _operator);
/// @}
/// Appends an implicit or explicit type conversion. For now this comprises only erasing
/// higher-order bits (@see appendHighBitCleanup) when widening integer types.
/// If @a _cleanupNeeded, high order bits cleanup is also done if no type conversion would be
/// necessary.
void appendTypeConversion(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded = false);
//// Appends code that cleans higher-order bits for integer types.
void appendHighBitsCleanup(IntegerType const& _typeOnStack);
/// Stores the value on top of the stack in the current lvalue and copies that value to the
/// top of the stack again
void storeInLValue(Expression const& _expression);
/// The same as storeInLValue but do not again retrieve the value to the top of the stack.
void moveToLValue(Expression const& _expression);
/// Returns the position of @a m_currentLValue in the stack, where 0 is the top of the stack.
unsigned stackPositionOfLValue() const;
Declaration* m_currentLValue;
CompilerContext& m_context;
};
}
}