Gas estimation taking known state into account.

2 files changed, 163 insertions, 4 deletions

diff --git a/libsolidity/GasMeter.cpp b/libsolidity/GasMeter.cpp
new file mode 100644
index 00000000..43eb3f95
--- /dev/null
+++ b/libsolidity/GasMeter.cpp
@@ -0,0 +1,156 @@
+/*
+	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
+ * Unit tests for the gas estimator.
+ */
+
+#include <test/libsolidity/solidityExecutionFramework.h>
+#include <libevmasm/GasMeter.h>
+#include <libevmasm/KnownState.h>
+#include <libsolidity/AST.h>
+#include <libsolidity/StructuralGasEstimator.h>
+#include <libsolidity/SourceReferenceFormatter.h>
+
+using namespace std;
+using namespace dev::eth;
+using namespace dev::solidity;
+
+namespace dev
+{
+namespace solidity
+{
+namespace test
+{
+
+class GasMeterTestFramework: public ExecutionFramework
+{
+public:
+	GasMeterTestFramework() { }
+	void compile(string const& _sourceCode)
+	{
+		m_compiler.setSource(_sourceCode);
+		ETH_TEST_REQUIRE_NO_THROW(m_compiler.compile(), "Compiling contract failed");
+
+		StructuralGasEstimator estimator;
+		AssemblyItems const* items = m_compiler.getRuntimeAssemblyItems("");
+		ASTNode const& sourceUnit = m_compiler.getAST();
+		BOOST_REQUIRE(items != nullptr);
+		m_gasCosts = estimator.breakToStatementLevel(
+			estimator.performEstimation(*items, vector<ASTNode const*>({&sourceUnit})),
+			{&sourceUnit}
+		);
+	}
+
+	void testCreationTimeGas(string const& _sourceCode, string const& _contractName = "")
+	{
+		compileAndRun(_sourceCode);
+		auto state = make_shared<KnownState>();
+		GasMeter meter(state);
+		GasMeter::GasConsumption gas;
+		for (AssemblyItem const& item: *m_compiler.getAssemblyItems(_contractName))
+			gas += meter.estimateMax(item);
+		u256 bytecodeSize(m_compiler.getRuntimeBytecode(_contractName).size());
+		gas += bytecodeSize * c_createDataGas;
+		BOOST_REQUIRE(!gas.isInfinite);
+		BOOST_CHECK(gas.value == m_gasUsed);
+	}
+
+protected:
+	map<ASTNode const*, eth::GasMeter::GasConsumption> m_gasCosts;
+};
+
+BOOST_FIXTURE_TEST_SUITE(GasMeterTests, GasMeterTestFramework)
+
+BOOST_AUTO_TEST_CASE(non_overlapping_filtered_costs)
+{
+	char const* sourceCode = R"(
+		contract test {
+			bytes x;
+			function f(uint a) returns (uint b) {
+				x.length = a;
+				for (; a < 200; ++a) {
+					x[a] = 9;
+					b = a * a;
+				}
+				return f(a - 1);
+			}
+		}
+	)";
+	compile(sourceCode);
+	for (auto first = m_gasCosts.cbegin(); first != m_gasCosts.cend(); ++first)
+	{
+		auto second = first;
+		for (++second; second != m_gasCosts.cend(); ++second)
+			if (first->first->getLocation().intersects(second->first->getLocation()))
+			{
+				BOOST_CHECK_MESSAGE(false, "Source locations should not overlap!");
+				SourceReferenceFormatter::printSourceLocation(cout, first->first->getLocation(), m_compiler.getScanner());
+				SourceReferenceFormatter::printSourceLocation(cout, second->first->getLocation(), m_compiler.getScanner());
+			}
+	}
+}
+
+BOOST_AUTO_TEST_CASE(simple_contract)
+{
+	// Tests a simple "deploy contract" code without constructor. The actual contract is not relevant.
+	char const* sourceCode = R"(
+		contract test {
+			bytes32 public shaValue;
+			function f(uint a) {
+				shaValue = sha3(a);
+			}
+		}
+	)";
+	testCreationTimeGas(sourceCode);
+}
+
+BOOST_AUTO_TEST_CASE(store_sha3)
+{
+	char const* sourceCode = R"(
+		contract test {
+			bytes32 public shaValue;
+			function test(uint a) {
+				shaValue = sha3(a);
+			}
+		}
+	)";
+	testCreationTimeGas(sourceCode);
+}
+
+BOOST_AUTO_TEST_CASE(updating_store)
+{
+	char const* sourceCode = R"(
+		contract test {
+			uint data;
+			uint data2;
+			function test() {
+				data = 1;
+				data = 2;
+				data2 = 0;
+			}
+		}
+	)";
+	testCreationTimeGas(sourceCode);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}
+}
+}
diff --git a/libsolidity/solidityExecutionFramework.h b/libsolidity/solidityExecutionFramework.h
index f76465f2..fa25fb12 100644
--- a/libsolidity/solidityExecutionFramework.h
+++ b/libsolidity/solidityExecutionFramework.h
@@ -44,11 +44,11 @@ public:
 
 	bytes const& compileAndRun(std::string const& _sourceCode, u256 const& _value = 0, std::string const& _contractName = "")
 	{
-		dev::solidity::CompilerStack compiler(m_addStandardSources);
-		compiler.addSource("", _sourceCode);
-		ETH_TEST_REQUIRE_NO_THROW(compiler.compile(m_optimize), "Compiling contract failed");
+		m_compiler.reset(false, m_addStandardSources);
+		m_compiler.addSource("", _sourceCode);
+		ETH_TEST_REQUIRE_NO_THROW(m_compiler.compile(m_optimize), "Compiling contract failed");
 
-		bytes code = compiler.getBytecode(_contractName);
+		bytes code = m_compiler.getBytecode(_contractName);
 		sendMessage(code, true, _value);
 		BOOST_REQUIRE(!m_output.empty());
 		return m_output;
@@ -160,12 +160,14 @@ protected:
 		BOOST_REQUIRE(executive.go());
 		m_state.noteSending(m_sender);
 		executive.finalize();
+		m_gasUsed = executive.gasUsed();
 		m_output = executive.out().toVector();
 		m_logs = executive.logs();
 	}
 
 	bool m_optimize = false;
 	bool m_addStandardSources = false;
+	dev::solidity::CompilerStack m_compiler;
 	Address m_sender;
 	Address m_contractAddress;
 	eth::State m_state;
@@ -173,6 +175,7 @@ protected:
 	u256 const m_gas = 100000000;
 	bytes m_output;
 	eth::LogEntries m_logs;
+	u256 m_gasUsed;
 };
 
 }