solidity/test/libyul/KnowledgeBaseTest.cpp
2022-03-14 19:32:33 +01:00

132 lines
3.8 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/>.
*/
/**
* Unit tests for KnowledgeBase
*/
#include <test/Common.h>
#include <test/libyul/Common.h>
#include <libyul/Object.h>
#include <libyul/optimiser/KnowledgeBase.h>
#include <libyul/optimiser/SSAValueTracker.h>
#include <libyul/optimiser/NameDispenser.h>
#include <libyul/optimiser/CommonSubexpressionEliminator.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <liblangutil/ErrorReporter.h>
#include <boost/test/unit_test.hpp>
using namespace std;
using namespace solidity::langutil;
namespace solidity::yul::test
{
class KnowledgeBaseTest
{
protected:
KnowledgeBase constructKnowledgeBase(string const& _source)
{
ErrorList errorList;
shared_ptr<AsmAnalysisInfo> analysisInfo;
std::tie(m_object, analysisInfo) = yul::test::parse(_source, m_dialect, errorList);
BOOST_REQUIRE(m_object && errorList.empty() && m_object->code);
NameDispenser dispenser(m_dialect, *m_object->code);
std::set<YulString> reserved;
OptimiserStepContext context{m_dialect, dispenser, reserved, 0};
CommonSubexpressionEliminator::run(context, *m_object->code);
m_ssaValues(*m_object->code);
for (auto const& [name, expression]: m_ssaValues.values())
m_values[name].value = expression;
return KnowledgeBase(m_dialect, [this](YulString _var) { return util::valueOrNullptr(m_values, _var); });
}
EVMDialect m_dialect{EVMVersion{}, true};
shared_ptr<Object> m_object;
SSAValueTracker m_ssaValues;
map<YulString, AssignedValue> m_values;
};
BOOST_FIXTURE_TEST_SUITE(KnowledgeBase, KnowledgeBaseTest)
BOOST_AUTO_TEST_CASE(basic)
{
yul::KnowledgeBase kb = constructKnowledgeBase(R"({
let a := calldataload(0)
let b := calldataload(0)
let zero := 0
let c := add(b, 0)
let d := mul(b, 0)
let e := sub(a, b)
})");
BOOST_CHECK(!kb.knownToBeDifferent("a"_yulstring, "b"_yulstring));
// This only works if the variable names are the same.
// It assumes that SSA+CSE+Simplifier actually replaces the variables.
BOOST_CHECK(!kb.knownToBeEqual("a"_yulstring, "b"_yulstring));
BOOST_CHECK(!kb.valueIfKnownConstant("a"_yulstring));
BOOST_CHECK(kb.valueIfKnownConstant("zero"_yulstring) == u256(0));
}
BOOST_AUTO_TEST_CASE(difference)
{
yul::KnowledgeBase kb = constructKnowledgeBase(R"({
let a := calldataload(0)
let b := add(a, 200)
let c := add(a, 220)
let d := add(c, 12)
let e := sub(c, 12)
})");
BOOST_CHECK(
kb.differenceIfKnownConstant("c"_yulstring, "b"_yulstring) ==
u256(20)
);
BOOST_CHECK(
kb.differenceIfKnownConstant("b"_yulstring, "c"_yulstring) ==
u256(-20)
);
BOOST_CHECK(!kb.knownToBeDifferentByAtLeast32("b"_yulstring, "c"_yulstring));
BOOST_CHECK(kb.knownToBeDifferentByAtLeast32("b"_yulstring, "d"_yulstring));
BOOST_CHECK(kb.knownToBeDifferentByAtLeast32("a"_yulstring, "b"_yulstring));
BOOST_CHECK(kb.knownToBeDifferentByAtLeast32("b"_yulstring, "a"_yulstring));
BOOST_CHECK(
kb.differenceIfKnownConstant("e"_yulstring, "a"_yulstring) == u256(208)
);
BOOST_CHECK(
kb.differenceIfKnownConstant("e"_yulstring, "b"_yulstring) == u256(8)
);
BOOST_CHECK(
kb.differenceIfKnownConstant("a"_yulstring, "e"_yulstring) == u256(-208)
);
BOOST_CHECK(
kb.differenceIfKnownConstant("b"_yulstring, "e"_yulstring) == u256(-8)
);
}
BOOST_AUTO_TEST_SUITE_END()
}