From 79f11974eafee20365c65c02798200353951564a Mon Sep 17 00:00:00 2001
From: chriseth <c@ethdev.com>
Date: Wed, 20 May 2015 00:27:07 +0200
Subject: [PATCH] Gas estimation taking known state into account.

---
 GasMeter.cpp => libsolidity/GasMeter.cpp | 60 +++++++++++++++++++++++-
 libsolidity/solidityExecutionFramework.h | 11 +++--
 2 files changed, 66 insertions(+), 5 deletions(-)
 rename GasMeter.cpp => libsolidity/GasMeter.cpp (66%)

diff --git a/GasMeter.cpp b/libsolidity/GasMeter.cpp
similarity index 66%
rename from GasMeter.cpp
rename to libsolidity/GasMeter.cpp
index 0ffe41712..43eb3f956 100644
--- a/GasMeter.cpp
+++ b/libsolidity/GasMeter.cpp
@@ -21,6 +21,8 @@
  */
 
 #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>
@@ -55,8 +57,21 @@ public:
 		);
 	}
 
+	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:
-	dev::solidity::CompilerStack m_compiler;
 	map<ASTNode const*, eth::GasMeter::GasConsumption> m_gasCosts;
 };
 
@@ -91,6 +106,49 @@ BOOST_AUTO_TEST_CASE(non_overlapping_filtered_costs)
 	}
 }
 
+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 f76465f23..fa25fb12c 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;
 };
 
 }