Some more base fees.

Author: chriseth

libevmasm/SimplificationRule.h

@@ -126,6 +126,7 @@ struct EVMBuiltins
 	static auto constexpr GASLIMIT = PatternGenerator<Instruction::GASLIMIT>{};
 	static auto constexpr CHAINID = PatternGenerator<Instruction::CHAINID>{};
 	static auto constexpr SELFBALANCE = PatternGenerator<Instruction::SELFBALANCE>{};
+	static auto constexpr BASEFEE = PatternGenerator<Instruction::BASEFEE>{};
 	static auto constexpr POP = PatternGenerator<Instruction::POP>{};
 	static auto constexpr MLOAD = PatternGenerator<Instruction::MLOAD>{};
 	static auto constexpr MSTORE = PatternGenerator<Instruction::MSTORE>{};

libsolidity/formal/Predicate.cpp

@@ -518,6 +518,7 @@ bool Predicate::fillArray(smtutil::Expression const& _expr, vector<string>& _arr
 map<string, optional<string>> Predicate::readTxVars(smtutil::Expression const& _tx) const
 {
 	map<string, Type const*> const txVars{
+		{"block.basefee", TypeProvider::uint256()},
 		{"block.chainid", TypeProvider::uint256()},
 		{"block.coinbase", TypeProvider::address()},
 		{"block.difficulty", TypeProvider::uint256()},

libsolidity/formal/SymbolicState.cpp

@@ -128,7 +128,9 @@ smtutil::Expression SymbolicState::txMember(string const& _member) const
 
 smtutil::Expression SymbolicState::txTypeConstraints() const
 {
-	return smt::symbolicUnknownConstraints(m_tx.member("block.chainid"), TypeProvider::uint256()) &&
+	return
+		smt::symbolicUnknownConstraints(m_tx.member("block.basefee"), TypeProvider::uint256()) &&
+		smt::symbolicUnknownConstraints(m_tx.member("block.chainid"), TypeProvider::uint256()) &&
 		smt::symbolicUnknownConstraints(m_tx.member("block.coinbase"), TypeProvider::address()) &&
 		smt::symbolicUnknownConstraints(m_tx.member("block.difficulty"), TypeProvider::uint256()) &&
 		smt::symbolicUnknownConstraints(m_tx.member("block.gaslimit"), TypeProvider::uint256()) &&

libsolidity/formal/SymbolicState.h

@@ -65,6 +65,7 @@ class BlockchainVariable
  *   - TODO: potentially storage of contracts
  * - block and transaction properties, represented as a tuple of:
  *   - blockhash
+ *   - block basefee
  *   - block chainid
  *   - block coinbase
  *   - block difficulty
@@ -191,6 +192,7 @@ class SymbolicState
 	BlockchainVariable m_tx{
 		"tx",
 		{
+			{"block.basefee", smtutil::SortProvider::uintSort},
 			{"block.chainid", smtutil::SortProvider::uintSort},
 			{"block.coinbase", smt::smtSort(*TypeProvider::address())},
 			{"block.difficulty", smtutil::SortProvider::uintSort},

libyul/backends/wasm/WasmDialect.cpp

@@ -190,6 +190,7 @@ void WasmDialect::addExternals()
 	static vector<External> externals{
 		{"eth", "getAddress", {i32ptr}, {}},
 		{"eth", "getExternalBalance", {i32ptr, i32ptr}, {}},
+		{"eth", "getBlockBaseFee", {i32ptr}, {}},
 		{"eth", "getBlockHash", {i64, i32ptr}, {i32}},
 		{"eth", "call", {i64, i32ptr, i32ptr, i32ptr, i32}, {i32}},
 		{"eth", "callDataCopy", {i32ptr, i32, i32}, {}},

test/libsolidity/analysis/FunctionCallGraph.cpp

@@ -1854,6 +1854,7 @@ BOOST_AUTO_TEST_CASE(builtins)
 				abi.encodePacked;
 				abi.encodeWithSelector;
 				abi.encodeWithSignature;
+				block.basefee;
 				block.chainid;
 				block.coinbase;
 				block.difficulty;

test/tools/yulInterpreter/EwasmBuiltinInterpreter.cpp

@@ -413,6 +413,11 @@ u256 EwasmBuiltinInterpreter::evalEthBuiltin(string const& _fun, vector<uint64_t
 		writeAddress(arg[3], h160(0xcccccc + arg[1]));
 		return 1;
 	}
+	else if (_fun == "getBlockBaseFee")
+	{
+		writeU128(arg[0], m_state.basefee);
+		return 0;
+	}
 	else if (_fun == "getBlockDifficulty")
 	{
 		writeU256(arg[0], m_state.difficulty);