Eliminates dead code around GasEstimator

- structuralEstimation()
- breakToStatementLevel()

libsolidity/interface/GasEstimator.cpp

@@ -42,93 +42,6 @@ using namespace solidity::evmasm;
 using namespace solidity::frontend;
 using namespace solidity::langutil;
 
-GasEstimator::ASTGasConsumptionSelfAccumulated GasEstimator::structuralEstimation(
-	AssemblyItems const& _items,
-	vector<ASTNode const*> const& _ast
-) const
-{
-	solAssert(std::count(_ast.begin(), _ast.end(), nullptr) == 0, "");
-	map<SourceLocation, GasConsumption> particularCosts;
-
-	ControlFlowGraph cfg(_items);
-	for (BasicBlock const& block: cfg.optimisedBlocks())
-	{
-		solAssert(!!block.startState, "");
-		GasMeter meter(block.startState->copy(), m_evmVersion);
-		auto const end = _items.begin() + static_cast<ptrdiff_t>(block.end);
-		for (auto iter = _items.begin() + static_cast<ptrdiff_t>(block.begin); iter != end; ++iter)
-			particularCosts[iter->location()] += meter.estimateMax(*iter);
-	}
-
-	set<ASTNode const*> finestNodes = finestNodesAtLocation(_ast);
-	ASTGasConsumptionSelfAccumulated gasCosts;
-	auto onNode = [&](ASTNode const& _node)
-	{
-		if (!finestNodes.count(&_node))
-			return true;
-		gasCosts[&_node][0] = gasCosts[&_node][1] = particularCosts[_node.location()];
-		return true;
-	};
-	auto onEdge = [&](ASTNode const& _parent, ASTNode const& _child)
-	{
-		gasCosts[&_parent][1] += gasCosts[&_child][1];
-	};
-	ASTReduce folder(onNode, onEdge);
-	for (ASTNode const* ast: _ast)
-		ast->accept(folder);
-
-	return gasCosts;
-}
-
-map<ASTNode const*, GasMeter::GasConsumption> GasEstimator::breakToStatementLevel(
-	ASTGasConsumptionSelfAccumulated const& _gasCosts,
-	vector<ASTNode const*> const& _roots
-)
-{
-	solAssert(std::count(_roots.begin(), _roots.end(), nullptr) == 0, "");
-	// first pass: statementDepth[node] is the distance from the deepend statement to node
-	// in direction of the tree root (or undefined if not possible)
-	map<ASTNode const*, int> statementDepth;
-	auto onNodeFirstPass = [&](ASTNode const& _node)
-	{
-		if (dynamic_cast<Statement const*>(&_node))
-			statementDepth[&_node] = 0;
-		return true;
-	};
-	auto onEdgeFirstPass = [&](ASTNode const& _parent, ASTNode const& _child)
-	{
-		if (statementDepth.count(&_child))
-			statementDepth[&_parent] = max(statementDepth[&_parent], statementDepth[&_child] + 1);
-	};
-	ASTReduce firstPass(onNodeFirstPass, onEdgeFirstPass);
-	for (ASTNode const* node: _roots)
-		node->accept(firstPass);
-
-	// we use the location of a node if
-	//  - its statement depth is 0 or
-	//  - its statement depth is undefined but the parent's statement depth is at least 1
-	map<ASTNode const*, GasConsumption> gasCosts;
-	auto onNodeSecondPass = [&](ASTNode const& _node)
-	{
-		return statementDepth.count(&_node);
-	};
-	auto onEdgeSecondPass = [&](ASTNode const& _parent, ASTNode const& _child)
-	{
-		bool useNode = false;
-		if (statementDepth.count(&_child))
-			useNode = statementDepth[&_child] == 0;
-		else
-			useNode = statementDepth.count(&_parent) && statementDepth.at(&_parent) > 0;
-		if (useNode)
-			gasCosts[&_child] = _gasCosts.at(&_child)[1];
-	};
-	ASTReduce secondPass(onNodeSecondPass, onEdgeSecondPass);
-	for (ASTNode const* node: _roots)
-		node->accept(secondPass);
-	// gasCosts should only contain non-overlapping locations
-	return gasCosts;
-}
-
 GasEstimator::GasConsumption GasEstimator::functionalEstimation(
 	AssemblyItems const& _items,
 	string const& _signature

libsolidity/interface/GasEstimator.h

@@ -48,22 +48,6 @@ public:
 
 	explicit GasEstimator(langutil::EVMVersion _evmVersion): m_evmVersion(_evmVersion) {}
 
-	/// Estimates the gas consumption for every assembly item in the given assembly and stores
-	/// it by source location.
-	/// @returns a mapping from each AST node to a pair of its particular and syntactically accumulated gas costs.
-	ASTGasConsumptionSelfAccumulated structuralEstimation(
-		evmasm::AssemblyItems const& _items,
-		std::vector<ASTNode const*> const& _ast
-	) const;
-	/// @returns a mapping from nodes with non-overlapping source locations to gas consumptions such that
-	/// the following source locations are part of the mapping:
-	/// 1. source locations of statements that do not contain other statements
-	/// 2. maximal source locations that do not overlap locations coming from the first rule
-	static ASTGasConsumption breakToStatementLevel(
-		ASTGasConsumptionSelfAccumulated const& _gasCosts,
-		std::vector<ASTNode const*> const& _roots
-	);
-
 	/// @returns the estimated gas consumption by the (public or external) function with the
 	/// given signature. If no signature is given, estimates the maximum gas usage.
 	GasConsumption functionalEstimation(

solc/CommandLineInterface.cpp

@@ -1638,18 +1638,6 @@ void CommandLineInterface::handleAst(string const& _argStr)
 		vector<ASTNode const*> asts;
 		for (auto const& sourceCode: m_sourceCodes)
 			asts.push_back(&m_compiler->ast(sourceCode.first));
-		map<ASTNode const*, evmasm::GasMeter::GasConsumption> gasCosts;
-		for (auto const& contract: m_compiler->contractNames())
-			if (m_compiler->compilationSuccessful())
-				if (auto const* assemblyItems = m_compiler->runtimeAssemblyItems(contract))
-				{
-					auto ret = GasEstimator::breakToStatementLevel(
-						GasEstimator(m_evmVersion).structuralEstimation(*assemblyItems, asts),
-						asts
-					);
-					for (auto const& it: ret)
-						gasCosts[it.first] += it.second;
-				}
 
 		bool legacyFormat = !m_args.count(g_argAstCompactJson);
 		if (m_args.count(g_argOutputDir))

test/libsolidity/GasMeter.cpp

@@ -49,14 +49,6 @@ public:
 		m_compiler.setOptimiserSettings(solidity::test::CommonOptions::get().optimize);
 		m_compiler.setEVMVersion(m_evmVersion);
 		BOOST_REQUIRE_MESSAGE(m_compiler.compile(), "Compiling contract failed");
-
-		AssemblyItems const* items = m_compiler.runtimeAssemblyItems(m_compiler.lastContractName());
-		ASTNode const& sourceUnit = m_compiler.ast("");
-		BOOST_REQUIRE(items != nullptr);
-		m_gasCosts = GasEstimator::breakToStatementLevel(
-			GasEstimator(solidity::test::CommonOptions::get().evmVersion()).structuralEstimation(*items, vector<ASTNode const*>({&sourceUnit})),
-			{&sourceUnit}
-		);
 	}
 
 	void testCreationTimeGas(string const& _sourceCode, u256 const& _tolerance = u256(0))
@@ -118,43 +110,10 @@ public:
 			gas += i != 0 ? GasCosts::txDataNonZeroGas(evmVersion) : GasCosts::txDataZeroGas;
 		return gas;
 	}
-
-protected:
-	map<ASTNode const*, evmasm::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) public returns (uint b) {
-				for (; a < 200; ++a) {
-					x.push(0x09);
-					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->location().intersects(second->first->location()))
-			{
-				BOOST_CHECK_MESSAGE(false, "Source locations should not overlap!");
-				langutil::SourceReferenceFormatter formatter(cout);
-
-				formatter.printSourceLocation(&first->first->location());
-				formatter.printSourceLocation(&second->first->location());
-			}
-	}
-}
-
 BOOST_AUTO_TEST_CASE(simple_contract)
 {
 	// Tests a simple "deploy contract" code without constructor. The actual contract is not relevant.