solidity/libsolidity/formal/SolverInterface.h

326 lines
9.6 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/>.
*/
#pragma once
#include <libsolidity/interface/ReadFile.h>
#include <liblangutil/Exceptions.h>
#include <libdevcore/Common.h>
#include <libdevcore/Exceptions.h>
#include <boost/noncopyable.hpp>
#include <cstdio>
#include <map>
#include <string>
#include <vector>
namespace dev
{
namespace solidity
{
namespace smt
{
enum class CheckResult
{
SATISFIABLE, UNSATISFIABLE, UNKNOWN, CONFLICTING, ERROR
};
enum class Kind
{
Int,
Bool,
Function,
Array
};
struct Sort
{
Sort(Kind _kind):
kind(_kind) {}
virtual ~Sort() = default;
virtual bool operator==(Sort const& _other) const { return kind == _other.kind; }
Kind const kind;
};
using SortPointer = std::shared_ptr<Sort>;
struct FunctionSort: public Sort
{
FunctionSort(std::vector<SortPointer> _domain, SortPointer _codomain):
Sort(Kind::Function), domain(std::move(_domain)), codomain(std::move(_codomain)) {}
bool operator==(Sort const& _other) const override
{
if (!Sort::operator==(_other))
return false;
auto _otherFunction = dynamic_cast<FunctionSort const*>(&_other);
solAssert(_otherFunction, "");
if (domain.size() != _otherFunction->domain.size())
return false;
if (!std::equal(
domain.begin(),
domain.end(),
_otherFunction->domain.begin(),
[&](SortPointer _a, SortPointer _b) { return *_a == *_b; }
))
return false;
solAssert(codomain, "");
solAssert(_otherFunction->codomain, "");
return *codomain == *_otherFunction->codomain;
}
std::vector<SortPointer> domain;
SortPointer codomain;
};
struct ArraySort: public Sort
{
/// _domain is the sort of the indices
/// _range is the sort of the values
ArraySort(SortPointer _domain, SortPointer _range):
Sort(Kind::Array), domain(std::move(_domain)), range(std::move(_range)) {}
bool operator==(Sort const& _other) const override
{
if (!Sort::operator==(_other))
return false;
auto _otherArray = dynamic_cast<ArraySort const*>(&_other);
solAssert(_otherArray, "");
solAssert(_otherArray->domain, "");
solAssert(_otherArray->range, "");
solAssert(domain, "");
solAssert(range, "");
return *domain == *_otherArray->domain && *range == *_otherArray->range;
}
SortPointer domain;
SortPointer range;
};
/// C++ representation of an SMTLIB2 expression.
class Expression
{
friend class SolverInterface;
public:
explicit Expression(bool _v): Expression(_v ? "true" : "false", Kind::Bool) {}
Expression(size_t _number): Expression(std::to_string(_number), Kind::Int) {}
Expression(u256 const& _number): Expression(_number.str(), Kind::Int) {}
Expression(s256 const& _number): Expression(_number.str(), Kind::Int) {}
Expression(bigint const& _number): Expression(_number.str(), Kind::Int) {}
Expression(Expression const&) = default;
Expression(Expression&&) = default;
Expression& operator=(Expression const&) = default;
Expression& operator=(Expression&&) = default;
bool hasCorrectArity() const
{
static std::map<std::string, unsigned> const operatorsArity{
{"ite", 3},
{"not", 1},
{"and", 2},
{"or", 2},
{"=", 2},
{"<", 2},
{"<=", 2},
{">", 2},
{">=", 2},
{"+", 2},
{"-", 2},
{"*", 2},
{"/", 2},
{"mod", 2},
{"select", 2},
{"store", 3}
};
return operatorsArity.count(name) && operatorsArity.at(name) == arguments.size();
}
static Expression ite(Expression _condition, Expression _trueValue, Expression _falseValue)
{
solAssert(*_trueValue.sort == *_falseValue.sort, "");
SortPointer sort = _trueValue.sort;
return Expression("ite", std::vector<Expression>{
std::move(_condition), std::move(_trueValue), std::move(_falseValue)
}, std::move(sort));
}
static Expression implies(Expression _a, Expression _b)
{
return !std::move(_a) || std::move(_b);
}
/// select is the SMT representation of an array index access.
static Expression select(Expression _array, Expression _index)
{
solAssert(_array.sort->kind == Kind::Array, "");
std::shared_ptr<ArraySort> arraySort = std::dynamic_pointer_cast<ArraySort>(_array.sort);
solAssert(arraySort, "");
solAssert(_index.sort, "");
solAssert(*arraySort->domain == *_index.sort, "");
return Expression(
"select",
std::vector<Expression>{std::move(_array), std::move(_index)},
arraySort->range
);
}
/// store is the SMT representation of an assignment to array index.
/// The function is pure and returns the modified array.
static Expression store(Expression _array, Expression _index, Expression _element)
{
solAssert(_array.sort->kind == Kind::Array, "");
std::shared_ptr<ArraySort> arraySort = std::dynamic_pointer_cast<ArraySort>(_array.sort);
solAssert(arraySort, "");
solAssert(_index.sort, "");
solAssert(_element.sort, "");
solAssert(*arraySort->domain == *_index.sort, "");
solAssert(*arraySort->range == *_element.sort, "");
return Expression(
"store",
std::vector<Expression>{std::move(_array), std::move(_index), std::move(_element)},
arraySort
);
}
friend Expression operator!(Expression _a)
{
return Expression("not", std::move(_a), Kind::Bool);
}
friend Expression operator&&(Expression _a, Expression _b)
{
return Expression("and", std::move(_a), std::move(_b), Kind::Bool);
}
friend Expression operator||(Expression _a, Expression _b)
{
return Expression("or", std::move(_a), std::move(_b), Kind::Bool);
}
friend Expression operator==(Expression _a, Expression _b)
{
return Expression("=", std::move(_a), std::move(_b), Kind::Bool);
}
friend Expression operator!=(Expression _a, Expression _b)
{
return !(std::move(_a) == std::move(_b));
}
friend Expression operator<(Expression _a, Expression _b)
{
return Expression("<", std::move(_a), std::move(_b), Kind::Bool);
}
friend Expression operator<=(Expression _a, Expression _b)
{
return Expression("<=", std::move(_a), std::move(_b), Kind::Bool);
}
friend Expression operator>(Expression _a, Expression _b)
{
return Expression(">", std::move(_a), std::move(_b), Kind::Bool);
}
friend Expression operator>=(Expression _a, Expression _b)
{
return Expression(">=", std::move(_a), std::move(_b), Kind::Bool);
}
friend Expression operator+(Expression _a, Expression _b)
{
return Expression("+", std::move(_a), std::move(_b), Kind::Int);
}
friend Expression operator-(Expression _a, Expression _b)
{
return Expression("-", std::move(_a), std::move(_b), Kind::Int);
}
friend Expression operator*(Expression _a, Expression _b)
{
return Expression("*", std::move(_a), std::move(_b), Kind::Int);
}
friend Expression operator/(Expression _a, Expression _b)
{
return Expression("/", std::move(_a), std::move(_b), Kind::Int);
}
friend Expression operator%(Expression _a, Expression _b)
{
return Expression("mod", std::move(_a), std::move(_b), Kind::Int);
}
Expression operator()(std::vector<Expression> _arguments) const
{
solAssert(
sort->kind == Kind::Function,
"Attempted function application to non-function."
);
auto fSort = dynamic_cast<FunctionSort const*>(sort.get());
solAssert(fSort, "");
return Expression(name, std::move(_arguments), fSort->codomain);
}
std::string name;
std::vector<Expression> arguments;
SortPointer sort;
private:
/// Manual constructors, should only be used by SolverInterface and this class itself.
Expression(std::string _name, std::vector<Expression> _arguments, SortPointer _sort):
name(std::move(_name)), arguments(std::move(_arguments)), sort(std::move(_sort)) {}
Expression(std::string _name, std::vector<Expression> _arguments, Kind _kind):
Expression(std::move(_name), std::move(_arguments), std::make_shared<Sort>(_kind)) {}
explicit Expression(std::string _name, Kind _kind):
Expression(std::move(_name), std::vector<Expression>{}, _kind) {}
Expression(std::string _name, Expression _arg, Kind _kind):
Expression(std::move(_name), std::vector<Expression>{std::move(_arg)}, _kind) {}
Expression(std::string _name, Expression _arg1, Expression _arg2, Kind _kind):
Expression(std::move(_name), std::vector<Expression>{std::move(_arg1), std::move(_arg2)}, _kind) {}
};
DEV_SIMPLE_EXCEPTION(SolverError);
class SolverInterface
{
public:
virtual ~SolverInterface() = default;
virtual void reset() = 0;
virtual void push() = 0;
virtual void pop() = 0;
virtual void declareVariable(std::string const& _name, Sort const& _sort) = 0;
Expression newVariable(std::string _name, SortPointer _sort)
{
// Subclasses should do something here
solAssert(_sort, "");
declareVariable(_name, *_sort);
return Expression(std::move(_name), {}, std::move(_sort));
}
virtual void addAssertion(Expression const& _expr) = 0;
/// Checks for satisfiability, evaluates the expressions if a model
/// is available. Throws SMTSolverError on error.
virtual std::pair<CheckResult, std::vector<std::string>>
check(std::vector<Expression> const& _expressionsToEvaluate) = 0;
/// @returns a list of queries that the system was not able to respond to.
virtual std::vector<std::string> unhandledQueries() { return {}; }
/// @returns how many SMT solvers this interface has.
virtual unsigned solvers() { return 1; }
protected:
// SMT query timeout in milliseconds.
static int const queryTimeout = 10000;
};
}
}
}