solidity/libsolidity/formal/Why3Translator.h
2016-07-13 11:16:00 +02:00

148 lines
5.0 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 2015
* Component that translates Solidity code into the why3 programming language.
*/
#pragma once
#include <libsolidity/ast/ASTVisitor.h>
#include <libsolidity/interface/Exceptions.h>
#include <string>
namespace dev
{
namespace solidity
{
class SourceUnit;
/**
* Simple translator from Solidity to Why3.
*
* @todo detect side effects in sub-expressions and limit them to one per statement.
* @todo `x = y = z`
* @todo implicit and explicit type conversion
*/
class Why3Translator: private ASTConstVisitor
{
public:
Why3Translator(ErrorList& _errors): m_lines(std::vector<Line>{{std::string(), 0}}), m_errors(_errors) {}
/// Appends formalisation of the given source unit to the output.
/// @returns false on error.
bool process(SourceUnit const& _source);
std::string translation() const;
private:
/// Creates an error and adds it to errors list.
void error(ASTNode const& _node, std::string const& _description);
/// Reports a fatal error and throws.
void fatalError(ASTNode const& _node, std::string const& _description);
/// Appends imports and constants use throughout the formal code.
void appendPreface();
/// @returns a string representation of the corresponding formal type or the empty string
/// if the type is not supported.
std::string toFormalType(Type const& _type) const;
void indent() { newLine(); m_lines.back().indentation++; }
void unindent();
void addLine(std::string const& _line);
void add(std::string const& _str);
void newLine();
void appendSemicolon();
virtual bool visit(SourceUnit const&) override { return true; }
virtual bool visit(ContractDefinition const& _contract) override;
virtual void endVisit(ContractDefinition const& _contract) override;
virtual bool visit(FunctionDefinition const& _function) override;
virtual void endVisit(FunctionDefinition const& _function) override;
virtual bool visit(Block const&) override;
virtual bool visit(IfStatement const& _node) override;
virtual bool visit(WhileStatement const& _node) override;
virtual bool visit(Return const& _node) override;
virtual bool visit(Throw const& _node) override;
virtual bool visit(VariableDeclarationStatement const& _node) override;
virtual bool visit(ExpressionStatement const&) override;
virtual bool visit(Assignment const& _node) override;
virtual bool visit(TupleExpression const& _node) override;
virtual void endVisit(TupleExpression const&) override { add(")"); }
virtual bool visit(UnaryOperation const& _node) override;
virtual bool visit(BinaryOperation const& _node) override;
virtual bool visit(FunctionCall const& _node) override;
virtual bool visit(MemberAccess const& _node) override;
virtual bool visit(IndexAccess const& _node) override;
virtual bool visit(Identifier const& _node) override;
virtual bool visit(Literal const& _node) override;
virtual bool visitNode(ASTNode const& _node) override
{
error(_node, "Code not supported for formal verification.");
return false;
}
bool isStateVariable(VariableDeclaration const* _var) const;
bool isStateVariable(std::string const& _name) const;
bool isLocalVariable(VariableDeclaration const* _var) const;
bool isLocalVariable(std::string const& _name) const;
/// @returns a string representing an expression that is a copy of this.storage
std::string copyOfStorage() const;
/// Visits the givin statement and indents it unless it is a block
/// (which does its own indentation).
void visitIndentedUnlessBlock(Statement const& _statement);
void addSourceFromDocStrings(DocumentedAnnotation const& _annotation);
/// Transforms substring like `#varName` and `#stateVarName` to code that evaluates to their value.
std::string transformVariableReferences(std::string const& _annotation);
/// True if we have already seen a contract. For now, only a single contract
/// is supported.
bool m_seenContract = false;
bool m_errorOccured = false;
/// Metadata relating to the current contract
struct ContractMetadata
{
ContractDefinition const* contract = nullptr;
std::vector<VariableDeclaration const*> stateVariables;
void reset() { contract = nullptr; stateVariables.clear(); }
};
ContractMetadata m_currentContract;
bool m_currentLValueIsRef = false;
std::map<std::string, VariableDeclaration const*> m_localVariables;
struct Line
{
std::string contents;
unsigned indentation;
};
std::vector<Line> m_lines;
ErrorList& m_errors;
};
}
}