Add option to choose solver

libsmtutil/SMTPortfolio.cpp

@@ -40,7 +40,8 @@ SMTPortfolio::SMTPortfolio(
 ):
 	SolverInterface(_queryTimeout)
 {
-	m_solvers.emplace_back(make_unique<SMTLib2Interface>(move(_smtlib2Responses), move(_smtCallback), m_queryTimeout));
+	if (_enabledSolvers.smtlib2)
+		m_solvers.emplace_back(make_unique<SMTLib2Interface>(move(_smtlib2Responses), move(_smtCallback), m_queryTimeout));
 #ifdef HAVE_Z3
 	if (_enabledSolvers.z3 && Z3Interface::available())
 		m_solvers.emplace_back(make_unique<Z3Interface>(m_queryTimeout));
@@ -143,10 +144,11 @@ pair<CheckResult, vector<string>> SMTPortfolio::check(vector<Expression> const&
 vector<string> SMTPortfolio::unhandledQueries()
 {
 	// This code assumes that the constructor guarantees that
-	// SmtLib2Interface is in position 0.
-	smtAssert(!m_solvers.empty(), "");
-	smtAssert(dynamic_cast<SMTLib2Interface*>(m_solvers.front().get()), "");
-	return m_solvers.front()->unhandledQueries();
+	// SmtLib2Interface is in position 0, if enabled.
+	if (!m_solvers.empty())
+		if (auto smtlib2 = dynamic_cast<SMTLib2Interface*>(m_solvers.front().get()))
+			return smtlib2->unhandledQueries();
+	return {};
 }
 
 bool SMTPortfolio::solverAnswered(CheckResult result)

libsmtutil/SolverInterface.h

@@ -23,10 +23,13 @@
 
 #include <libsolutil/Common.h>
 
+#include <range/v3/view.hpp>
+
 #include <cstdio>
 #include <map>
 #include <memory>
 #include <optional>
+#include <set>
 #include <string>
 #include <vector>
 
@@ -36,16 +39,71 @@ namespace solidity::smtutil
 struct SMTSolverChoice
 {
 	bool cvc4 = false;
+	bool smtlib2 = false;
 	bool z3 = false;
 
-	static constexpr SMTSolverChoice All() { return {true, true}; }
-	static constexpr SMTSolverChoice CVC4() { return {true, false}; }
-	static constexpr SMTSolverChoice Z3() { return {false, true}; }
-	static constexpr SMTSolverChoice None() { return {false, false}; }
+	static constexpr SMTSolverChoice All() { return {true, true, true}; }
+	static constexpr SMTSolverChoice CVC4() { return {true, false, false}; }
+	static constexpr SMTSolverChoice SMTLIB2() { return {false, true, false}; }
+	static constexpr SMTSolverChoice Z3() { return {false, false, true}; }
+	static constexpr SMTSolverChoice None() { return {false, false, false}; }
+
+	static std::optional<SMTSolverChoice> fromString(std::string const& _solvers)
+	{
+		SMTSolverChoice solvers;
+		if (_solvers == "all")
+		{
+			smtAssert(solvers.setSolver("cvc4"), "");
+			smtAssert(solvers.setSolver("smtlib2"), "");
+			smtAssert(solvers.setSolver("z3"), "");
+		}
+		else
+			for (auto&& s: _solvers | ranges::views::split(',') | ranges::to<std::vector<std::string>>())
+				if (!solvers.setSolver(s))
+					return {};
+
+		return solvers;
+	}
+
+	SMTSolverChoice& operator&(SMTSolverChoice const& _other)
+	{
+		cvc4 &= _other.cvc4;
+		smtlib2 &= _other.smtlib2;
+		z3 &= _other.z3;
+		return *this;
+	}
+
+	SMTSolverChoice& operator&=(SMTSolverChoice const& _other)
+	{
+		return *this & _other;
+	}
+
+	bool operator!=(SMTSolverChoice const& _other) const noexcept { return !(*this == _other); }
+
+	bool operator==(SMTSolverChoice const& _other) const noexcept
+	{
+		return cvc4 == _other.cvc4 &&
+			smtlib2 == _other.smtlib2 &&
+			z3 == _other.z3;
+	}
+
+	bool setSolver(std::string const& _solver)
+	{
+		static std::set<std::string> const solvers{"cvc4", "smtlib2", "z3"};
+		if (!solvers.count(_solver))
+			return false;
+		if (_solver == "cvc4")
+			cvc4 = true;
+		else if (_solver == "smtlib2")
+			smtlib2 = true;
+		else if (_solver == "z3")
+			z3 = true;
+		return true;
+	}
 
 	bool none() { return !some(); }
-	bool some() { return cvc4 || z3; }
-	bool all() { return cvc4 && z3; }
+	bool some() { return cvc4 || smtlib2 || z3; }
+	bool all() { return cvc4 && smtlib2 && z3; }
 };
 
 enum class CheckResult