Extend knowledge base.

test/libyul/KnowledgeBaseTest.cpp

@@ -0,0 +1,84 @@
+/*
+    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/DataFlowAnalyzer.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<Object> object;
+		shared_ptr<AsmAnalysisInfo> analysisInfo;
+		std::tie(object, analysisInfo) = yul::test::parse(_source, m_dialect, errorList);
+		BOOST_REQUIRE(object && errorList.empty() && object->code);
+
+		SSAValueTracker ssaValues;
+		ssaValues(*object->code);
+		for (auto const& [name, expression]: ssaValues.values())
+			m_values[name].value = expression;
+
+		return KnowledgeBase(m_dialect, m_values);
+	}
+
+	EVMDialect m_dialect{EVMVersion{}, true};
+	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));
+	BOOST_CHECK(kb.valueIfKnownConstant("zero"_yulstring) == u256(0));
+
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}