Adds support for the EVM version "Paris".

Deprecates `block.difficulty` and disallow `difficulty()` in inline assembly for EVM versions >= paris.
The change is due to the renaming introduced by EIP-4399 (see: https://eips.ethereum.org/EIPS/eip-4399).
Introduces `block.prevrandao` in Solidity and `prevrandao()` in inline assembly for EVM versions >= paris.

Co-authored-by: Alex Beregszaszi <alex@rtfs.hu>
Co-authored-by: Daniel <daniel@ekpyron.org>
Co-authored-by: matheusaaguiar <95899911+matheusaaguiar@users.noreply.github.com>
Co-authored-by: Nikola Matić <nikola.matic@ethereum.org>

Changelog.md

@@ -7,7 +7,9 @@ Language Features:
 Compiler Features:
  * Commandline Interface: Return exit code ``2`` on uncaught exceptions.
  * Commandline Interface: Add `--no-cbor-metadata` that skips CBOR metadata from getting appended at the end of the bytecode.
- * EVM: Basic support for the EVM version "Paris".
+ * EVM: Deprecate ``block.difficulty`` and disallow ``difficulty()`` in inline assembly for EVM versions >= paris. The change is due to the renaming introduced by [EIP-4399](https://eips.ethereum.org/EIPS/eip-4399).
+ * EVM: Introduce ``block.prevrandao`` in Solidity and ``prevrandao()`` in inline assembly for EVM versions >= paris.
+ * EVM: Support for the EVM version "Paris".
  * Natspec: Add event Natspec inheritance for devdoc.
  * Standard JSON: Add a boolean field `settings.metadata.appendCBOR` that skips CBOR metadata from getting appended at the end of the bytecode.
  * Yul EVM Code Transform: Generate more optimal code for user-defined functions that always terminate a transaction. No return labels will be pushed for calls to functions that always terminate.

docs/cheatsheet.rst

@@ -8,7 +8,7 @@ Order of Precedence of Operators
 ================================
 .. include:: types/operator-precedence-table.rst
 
-.. index:: assert, block, coinbase, difficulty, number, block;number, timestamp, block;timestamp, msg, data, gas, sender, value, gas price, origin, revert, require, keccak256, ripemd160, sha256, ecrecover, addmod, mulmod, cryptography, this, super, selfdestruct, balance, codehash, send
+.. index:: assert, block, coinbase, difficulty, prevrandao, number, block;number, timestamp, block;timestamp, msg, data, gas, sender, value, gas price, origin, revert, require, keccak256, ripemd160, sha256, ecrecover, addmod, mulmod, cryptography, this, super, selfdestruct, balance, codehash, send
 
 Global Variables
 ================
@@ -32,9 +32,10 @@ Global Variables
 - ``block.basefee`` (``uint``): current block's base fee (`EIP-3198 <https://eips.ethereum.org/EIPS/eip-3198>`_ and `EIP-1559 <https://eips.ethereum.org/EIPS/eip-1559>`_)
 - ``block.chainid`` (``uint``): current chain id
 - ``block.coinbase`` (``address payable``): current block miner's address
-- ``block.difficulty`` (``uint``): current block difficulty
+- ``block.difficulty`` (``uint``): current block difficulty (``EVM < Paris``). For other EVM versions it behaves as a deprecated alias for ``block.prevrandao`` that will be removed in the next breaking release
 - ``block.gaslimit`` (``uint``): current block gaslimit
 - ``block.number`` (``uint``): current block number
+- ``block.prevrandao`` (``uint``): random number provided by the beacon chain (``EVM >= Paris``) (see `EIP-4399 <https://eips.ethereum.org/EIPS/eip-4399>`_ )
 - ``block.timestamp`` (``uint``): current block timestamp in seconds since Unix epoch
 - ``gasleft() returns (uint256)``: remaining gas
 - ``msg.data`` (``bytes``): complete calldata

docs/grammar/SolidityLexer.g4

@@ -291,8 +291,8 @@ YulEVMBuiltin:
 	| 'returndatacopy' | 'extcodehash' | 'create' | 'create2' | 'call' | 'callcode'
 	| 'delegatecall' | 'staticcall' | 'return' | 'revert' | 'selfdestruct' | 'invalid'
 	| 'log0' | 'log1' | 'log2' | 'log3' | 'log4' | 'chainid' | 'origin' | 'gasprice'
-	| 'blockhash' | 'coinbase' | 'timestamp' | 'number' | 'difficulty' | 'gaslimit'
+	| 'blockhash' | 'coinbase' | 'timestamp' | 'number' | 'difficulty' | 'prevrandao'
-	| 'basefee';
+	| 'gaslimit' | 'basefee';
 
 YulLBrace: '{' -> pushMode(YulMode);
 YulRBrace: '}' -> popMode;

docs/units-and-global-variables.rst

@@ -65,7 +65,7 @@ There are special variables and functions which always exist in the global
 namespace and are mainly used to provide information about the blockchain
 or are general-use utility functions.
 
-.. index:: abi, block, coinbase, difficulty, encode, number, block;number, timestamp, block;timestamp, msg, data, gas, sender, value, gas price, origin
+.. index:: abi, block, coinbase, difficulty, prevrandao, encode, number, block;number, timestamp, block;timestamp, msg, data, gas, sender, value, gas price, origin
 
 
 Block and Transaction Properties
@@ -75,9 +75,10 @@ Block and Transaction Properties
 - ``block.basefee`` (``uint``): current block's base fee (`EIP-3198 <https://eips.ethereum.org/EIPS/eip-3198>`_ and `EIP-1559 <https://eips.ethereum.org/EIPS/eip-1559>`_)
 - ``block.chainid`` (``uint``): current chain id
 - ``block.coinbase`` (``address payable``): current block miner's address
-- ``block.difficulty`` (``uint``): current block difficulty
+- ``block.difficulty`` (``uint``): current block difficulty (``EVM < Paris``). For other EVM versions it behaves as a deprecated alias for ``block.prevrandao`` (`EIP-4399 <https://eips.ethereum.org/EIPS/eip-4399>`_ )
 - ``block.gaslimit`` (``uint``): current block gaslimit
 - ``block.number`` (``uint``): current block number
+- ``block.prevrandao`` (``uint``): random number provided by the beacon chain (``EVM >= Paris``)
 - ``block.timestamp`` (``uint``): current block timestamp as seconds since unix epoch
 - ``gasleft() returns (uint256)``: remaining gas
 - ``msg.data`` (``bytes calldata``): complete calldata

docs/yul.rst

@@ -751,8 +751,8 @@ This document does not want to be a full description of the Ethereum virtual mac
 Please refer to a different document if you are interested in the precise semantics.
 
 Opcodes marked with ``-`` do not return a result and all others return exactly one value.
-Opcodes marked with ``F``, ``H``, ``B``, ``C``, ``I`` and ``L`` are present since Frontier, Homestead,
+Opcodes marked with ``F``, ``H``, ``B``, ``C``, ``I``, ``L`` and ``P`` are present since Frontier,
-Byzantium, Constantinople, Istanbul or London respectively.
+Homestead, Byzantium, Constantinople, Istanbul, London or Paris respectively.
 
 In the following, ``mem[a...b)`` signifies the bytes of memory starting at position ``a`` up to
 but not including position ``b`` and ``storage[p]`` signifies the storage contents at slot ``p``.
@@ -931,6 +931,8 @@ the ``dup`` and ``swap`` instructions as well as ``jump`` instructions, labels a
 +-------------------------+-----+---+-----------------------------------------------------------------+
 | difficulty()            |     | F | difficulty of the current block (see note below)                |
 +-------------------------+-----+---+-----------------------------------------------------------------+
+| prevrandao()            |     | P | randomness provided by the beacon chain (see note below)        |
++-------------------------+-----+---+-----------------------------------------------------------------+
 | gaslimit()              |     | F | block gas limit of the current block                            |
 +-------------------------+-----+---+-----------------------------------------------------------------+
 
@@ -945,8 +947,10 @@ the ``dup`` and ``swap`` instructions as well as ``jump`` instructions, labels a
   The remaining bytes will retain their values as of before the call.
 
 .. note::
-  With the Paris network upgrade the semantics of ``difficulty`` have been changed.
+  The `difficulty()` instruction is disallowed in EVM version >= Paris.
-  It returns the value of ``prevrandao``, which is a 256-bit value, whereas the highest recorded
+  With the Paris network upgrade the semantics of the instruction that was previously called
+  ``difficulty`` have been changed and the instruction was renamed to ``prevrandao``.
+  It can now return arbitrary values in the full 256-bit range, whereas the highest recorded
   difficulty value within Ethash was ~54 bits.
   This change is described in `EIP-4399 <https://eips.ethereum.org/EIPS/eip-4399>`_.
   Please note that irrelevant to which EVM version is selected in the compiler, the semantics of

libevmasm/Assembly.cpp

@@ -237,7 +237,7 @@ Json::Value Assembly::assemblyJSON(map<string, unsigned> const& _sourceIndices,
 				sourceIndex = static_cast<int>(iter->second);
 		}
 
-		auto [name, data] = item.nameAndData();
+		auto [name, data] = item.nameAndData(m_evmVersion);
 		Json::Value jsonItem;
 		jsonItem["name"] = name;
 		jsonItem["begin"] = item.location().start;

libevmasm/Assembly.h

@@ -49,7 +49,7 @@ using AssemblyPointer = std::shared_ptr<Assembly>;
 class Assembly
 {
 public:
-	Assembly(bool _creation, std::string _name): m_creation(_creation), m_name(std::move(_name)) { }
+	Assembly(langutil::EVMVersion _evmVersion, bool _creation, std::string _name): m_evmVersion(_evmVersion), m_creation(_creation), m_name(std::move(_name)) { }
 
 	AssemblyItem newTag() { assertThrow(m_usedTags < 0xffffffff, AssemblyException, ""); return AssemblyItem(Tag, m_usedTags++); }
 	AssemblyItem newPushTag() { assertThrow(m_usedTags < 0xffffffff, AssemblyException, ""); return AssemblyItem(PushTag, m_usedTags++); }
@@ -112,6 +112,7 @@ public:
 	/// Changes the source location used for each appended item.
 	void setSourceLocation(langutil::SourceLocation const& _location) { m_currentSourceLocation = _location; }
 	langutil::SourceLocation const& currentSourceLocation() const { return m_currentSourceLocation; }
+	langutil::EVMVersion const& evmVersion() const { return m_evmVersion; }
 
 	/// Assembles the assembly into bytecode. The assembly should not be modified after this call, since the assembled version is cached.
 	LinkerObject const& assemble() const;
@@ -208,6 +209,8 @@ protected:
 	mutable LinkerObject m_assembledObject;
 	mutable std::vector<size_t> m_tagPositionsInBytecode;
 
+	langutil::EVMVersion m_evmVersion;
+
 	int m_deposit = 0;
 	/// True, if the assembly contains contract creation code.
 	bool const m_creation = false;

libevmasm/AssemblyItem.cpp

@@ -69,12 +69,12 @@ pair<size_t, size_t> AssemblyItem::splitForeignPushTag() const
 	return make_pair(subId, tag);
 }
 
-pair<string, string> AssemblyItem::nameAndData() const
+pair<string, string> AssemblyItem::nameAndData(langutil::EVMVersion _evmVersion) const
 {
 	switch (type())
 	{
 	case Operation:
-		return {instructionInfo(instruction()).name, m_data != nullptr ? toStringInHex(*m_data) : ""};
+		return {instructionInfo(instruction(), _evmVersion).name, m_data != nullptr ? toStringInHex(*m_data) : ""};
 	case Push:
 		return {"PUSH", toStringInHex(data())};
 	case PushTag:
@@ -168,7 +168,9 @@ size_t AssemblyItem::bytesRequired(size_t _addressLength, Precision _precision)
 size_t AssemblyItem::arguments() const
 {
 	if (type() == Operation)
-		return static_cast<size_t>(instructionInfo(instruction()).args);
+		// The latest EVMVersion is used here, since the InstructionInfo is assumed to be
+		// the same across all EVM versions except for the instruction name.
+		return static_cast<size_t>(instructionInfo(instruction(), EVMVersion()).args);
 	else if (type() == VerbatimBytecode)
 		return get<0>(*m_verbatimBytecode);
 	else if (type() == AssignImmutable)
@@ -182,7 +184,9 @@ size_t AssemblyItem::returnValues() const
 	switch (m_type)
 	{
 	case Operation:
-		return static_cast<size_t>(instructionInfo(instruction()).ret);
+		// The latest EVMVersion is used here, since the InstructionInfo is assumed to be
+		// the same across all EVM versions except for the instruction name.
+		return static_cast<size_t>(instructionInfo(instruction(), EVMVersion()).ret);
 	case Push:
 	case PushTag:
 	case PushData:
@@ -251,7 +255,7 @@ string AssemblyItem::toAssemblyText(Assembly const& _assembly) const
 	case Operation:
 	{
 		assertThrow(isValidInstruction(instruction()), AssemblyException, "Invalid instruction.");
-		text = util::toLower(instructionInfo(instruction()).name);
+		text = util::toLower(instructionInfo(instruction(), _assembly.evmVersion()).name);
 		break;
 	}
 	case Push:
@@ -323,12 +327,13 @@ string AssemblyItem::toAssemblyText(Assembly const& _assembly) const
 	return text;
 }
 
+// Note: This method is exclusively used for debugging.
 ostream& solidity::evmasm::operator<<(ostream& _out, AssemblyItem const& _item)
 {
 	switch (_item.type())
 	{
 	case Operation:
-		_out << " " << instructionInfo(_item.instruction()).name;
+		_out << " " << instructionInfo(_item.instruction(), EVMVersion()).name;
 		if (_item.instruction() == Instruction::JUMP || _item.instruction() == Instruction::JUMPI)
 			_out << "\t" << _item.getJumpTypeAsString();
 		break;

libevmasm/AssemblyItem.h

@@ -108,10 +108,11 @@ public:
 
 	/// This function is used in `Assembly::assemblyJSON`.
 	/// It returns the name & data of the current assembly item.
+	/// @param _evmVersion the EVM version.
 	/// @returns a pair, where the first element is the json-assembly
 	/// item name, where second element is the string representation
 	/// of it's data.
-	std::pair<std::string, std::string> nameAndData() const;
+	std::pair<std::string, std::string> nameAndData(langutil::EVMVersion _evmVersion) const;
 
 	bytes const& verbatimData() const { assertThrow(m_type == VerbatimBytecode, util::Exception, ""); return std::get<2>(*m_verbatimBytecode); }
 

libevmasm/CommonSubexpressionEliminator.cpp

@@ -406,7 +406,7 @@ void CSECodeGenerator::generateClassElement(Id _c, bool _allowSequenced)
 		m_stack.erase(m_stackHeight - static_cast<int>(i));
 	}
 	appendItem(*expr.item);
-	if (expr.item->type() != Operation || instructionInfo(expr.item->instruction()).ret == 1)
+	if (expr.item->type() != Operation || instructionInfo(expr.item->instruction(), EVMVersion()).ret == 1)
 	{
 		m_stack[m_stackHeight] = _c;
 		m_classPositions[_c].insert(m_stackHeight);
@@ -414,7 +414,7 @@ void CSECodeGenerator::generateClassElement(Id _c, bool _allowSequenced)
 	else
 	{
 		assertThrow(
-			instructionInfo(expr.item->instruction()).ret == 0,
+			instructionInfo(expr.item->instruction(), EVMVersion()).ret == 0,
 			OptimizerException,
 			"Invalid number of return values."
 		);

libevmasm/ConstantOptimiser.cpp

@@ -79,18 +79,18 @@ unsigned ConstantOptimisationMethod::optimiseConstants(
 	return optimisations;
 }
 
-bigint ConstantOptimisationMethod::simpleRunGas(AssemblyItems const& _items)
+bigint ConstantOptimisationMethod::simpleRunGas(AssemblyItems const& _items, langutil::EVMVersion _evmVersion)
 {
 	bigint gas = 0;
 	for (AssemblyItem const& item: _items)
 		if (item.type() == Push)
-			gas += GasMeter::runGas(Instruction::PUSH1);
+			gas += GasMeter::runGas(Instruction::PUSH1, _evmVersion);
 		else if (item.type() == Operation)
 		{
 			if (item.instruction() == Instruction::EXP)
 				gas += GasCosts::expGas;
 			else
-				gas += GasMeter::runGas(item.instruction());
+				gas += GasMeter::runGas(item.instruction(), _evmVersion);
 		}
 	return gas;
 }
@@ -131,7 +131,7 @@ void ConstantOptimisationMethod::replaceConstants(
 bigint LiteralMethod::gasNeeded() const
 {
 	return combineGas(
-		simpleRunGas({Instruction::PUSH1}),
+		simpleRunGas({Instruction::PUSH1}, m_params.evmVersion),
 		// PUSHX plus data
 		(m_params.isCreation ? GasCosts::txDataNonZeroGas(m_params.evmVersion) : GasCosts::createDataGas) + dataGas(toCompactBigEndian(m_value, 1)),
 		0
@@ -142,7 +142,7 @@ bigint CodeCopyMethod::gasNeeded() const
 {
 	return combineGas(
 		// Run gas: we ignore memory increase costs
-		simpleRunGas(copyRoutine()) + GasCosts::copyGas,
+		simpleRunGas(copyRoutine(), m_params.evmVersion) + GasCosts::copyGas,
 		// Data gas for copy routines: Some bytes are zero, but we ignore them.
 		bytesRequired(copyRoutine()) * (m_params.isCreation ? GasCosts::txDataNonZeroGas(m_params.evmVersion) : GasCosts::createDataGas),
 		// Data gas for data itself
@@ -322,7 +322,7 @@ bigint ComputeMethod::gasNeeded(AssemblyItems const& _routine) const
 {
 	auto numExps = static_cast<size_t>(count(_routine.begin(), _routine.end(), Instruction::EXP));
 	return combineGas(
-		simpleRunGas(_routine) + numExps * (GasCosts::expGas + GasCosts::expByteGas(m_params.evmVersion)),
+		simpleRunGas(_routine, m_params.evmVersion) + numExps * (GasCosts::expGas + GasCosts::expByteGas(m_params.evmVersion)),
 		// Data gas for routine: Some bytes are zero, but we ignore them.
 		bytesRequired(_routine) * (m_params.isCreation ? GasCosts::txDataNonZeroGas(m_params.evmVersion) : GasCosts::createDataGas),
 		0

libevmasm/ConstantOptimiser.h

@@ -76,7 +76,7 @@ protected:
 
 protected:
 	/// @returns the run gas for the given items ignoring special gas costs
-	static bigint simpleRunGas(AssemblyItems const& _items);
+	static bigint simpleRunGas(AssemblyItems const& _items, langutil::EVMVersion _evmVersion);
 	/// @returns the gas needed to store the given data literally
 	bigint dataGas(bytes const& _data) const;
 	static size_t bytesRequired(AssemblyItems const& _items);

libevmasm/Disassemble.cpp

@@ -30,6 +30,7 @@ using namespace solidity::evmasm;
 
 void solidity::evmasm::eachInstruction(
 	bytes const& _mem,
+	langutil::EVMVersion _evmVersion,
 	function<void(Instruction,u256 const&)> const& _onInstruction
 )
 {
@@ -38,7 +39,7 @@ void solidity::evmasm::eachInstruction(
 		Instruction const instr{*it};
 		int additional = 0;
 		if (isValidInstruction(instr))
-			additional = instructionInfo(instr).additional;
+			additional = instructionInfo(instr, _evmVersion).additional;
 
 		u256 data{};
 
@@ -57,15 +58,15 @@ void solidity::evmasm::eachInstruction(
 	}
 }
 
-string solidity::evmasm::disassemble(bytes const& _mem, string const& _delimiter)
+string solidity::evmasm::disassemble(bytes const& _mem, langutil::EVMVersion _evmVersion, string const& _delimiter)
 {
 	stringstream ret;
-	eachInstruction(_mem, [&](Instruction _instr, u256 const& _data) {
+	eachInstruction(_mem, _evmVersion, [&](Instruction _instr, u256 const& _data) {
 		if (!isValidInstruction(_instr))
 			ret << "0x" << std::uppercase << std::hex << static_cast<int>(_instr) << _delimiter;
 		else
 		{
-			InstructionInfo info = instructionInfo(_instr);
+			InstructionInfo info = instructionInfo(_instr, _evmVersion);
 			ret << info.name;
 			if (info.additional)
 				ret << " 0x" << std::uppercase << std::hex << _data;

libevmasm/Disassemble.h

@@ -30,9 +30,9 @@ namespace solidity::evmasm
 {
 
 /// Iterate through EVM code and call a function on each instruction.
-void eachInstruction(bytes const& _mem, std::function<void(Instruction, u256 const&)> const& _onInstruction);
+void eachInstruction(bytes const& _mem, langutil::EVMVersion _evmVersion, std::function<void(Instruction, u256 const&)> const& _onInstruction);
 
 /// Convert from EVM code to simple EVM assembly language.
-std::string disassemble(bytes const& _mem, std::string const& _delimiter = " ");
+std::string disassemble(bytes const& _mem, langutil::EVMVersion _evmVersion, std::string const& _delimiter = " ");
 
 }

libevmasm/GasMeter.cpp

@@ -52,10 +52,10 @@ GasMeter::GasConsumption GasMeter::estimateMax(AssemblyItem const& _item, bool _
 	case PushProgramSize:
 	case PushLibraryAddress:
 	case PushDeployTimeAddress:
-		gas = runGas(Instruction::PUSH1);
+		gas = runGas(Instruction::PUSH1, m_evmVersion);
 		break;
 	case Tag:
-		gas = runGas(Instruction::JUMPDEST);
+		gas = runGas(Instruction::JUMPDEST, m_evmVersion);
 		break;
 	case Operation:
 	{
@@ -80,19 +80,19 @@ GasMeter::GasConsumption GasMeter::estimateMax(AssemblyItem const& _item, bool _
 			break;
 		case Instruction::RETURN:
 		case Instruction::REVERT:
-			gas = runGas(_item.instruction());
+			gas = runGas(_item.instruction(), m_evmVersion);
 			gas += memoryGas(0, -1);
 			break;
 		case Instruction::MLOAD:
 		case Instruction::MSTORE:
-			gas = runGas(_item.instruction());
+			gas = runGas(_item.instruction(), m_evmVersion);
 			gas += memoryGas(classes.find(Instruction::ADD, {
 				m_state->relativeStackElement(0),
 				classes.find(AssemblyItem(32))
 			}));
 			break;
 		case Instruction::MSTORE8:
-			gas = runGas(_item.instruction());
+			gas = runGas(_item.instruction(), m_evmVersion);
 			gas += memoryGas(classes.find(Instruction::ADD, {
 				m_state->relativeStackElement(0),
 				classes.find(AssemblyItem(1))
@@ -106,7 +106,7 @@ GasMeter::GasConsumption GasMeter::estimateMax(AssemblyItem const& _item, bool _
 		case Instruction::CALLDATACOPY:
 		case Instruction::CODECOPY:
 		case Instruction::RETURNDATACOPY:
-			gas = runGas(_item.instruction());
+			gas = runGas(_item.instruction(), m_evmVersion);
 			gas += memoryGas(0, -2);
 			gas += wordGas(GasCosts::copyGas, m_state->relativeStackElement(-2));
 			break;
@@ -195,13 +195,13 @@ GasMeter::GasConsumption GasMeter::estimateMax(AssemblyItem const& _item, bool _
 			gas = GasCosts::balanceGas(m_evmVersion);
 			break;
 		case Instruction::CHAINID:
-			gas = runGas(Instruction::CHAINID);
+			gas = runGas(Instruction::CHAINID, m_evmVersion);
 			break;
 		case Instruction::SELFBALANCE:
-			gas = runGas(Instruction::SELFBALANCE);
+			gas = runGas(Instruction::SELFBALANCE, m_evmVersion);
 			break;
 		default:
-			gas = runGas(_item.instruction());
+			gas = runGas(_item.instruction(), m_evmVersion);
 			break;
 		}
 		break;
@@ -252,12 +252,12 @@ GasMeter::GasConsumption GasMeter::memoryGas(int _stackPosOffset, int _stackPosS
 		}));
 }
 
-unsigned GasMeter::runGas(Instruction _instruction)
+unsigned GasMeter::runGas(Instruction _instruction, langutil::EVMVersion _evmVersion)
 {
 	if (_instruction == Instruction::JUMPDEST)
 		return 1;
 
-	switch (instructionInfo(_instruction).gasPriceTier)
+	switch (instructionInfo(_instruction, _evmVersion).gasPriceTier)
 	{
 	case Tier::Zero:    return GasCosts::tier0Gas;
 	case Tier::Base:    return GasCosts::tier1Gas;
@@ -268,7 +268,7 @@ unsigned GasMeter::runGas(Instruction _instruction)
 	case Tier::Ext:     return GasCosts::tier6Gas;
 	default: break;
 	}
-	assertThrow(false, OptimizerException, "Invalid gas tier for instruction " + instructionInfo(_instruction).name);
+	assertThrow(false, OptimizerException, "Invalid gas tier for instruction " + instructionInfo(_instruction, _evmVersion).name);
 	return 0;
 }
 

libevmasm/GasMeter.h

@@ -221,7 +221,7 @@ public:
 
 	/// @returns gas costs for simple instructions with constant gas costs (that do not
 	/// change with EVM versions)
-	static unsigned runGas(Instruction _instruction);
+	static unsigned runGas(Instruction _instruction, langutil::EVMVersion _evmVersion);
 
 	/// @returns the gas cost of the supplied data, depending whether it is in creation code, or not.
 	/// In case of @a _inCreation, the data is only sent as a transaction and is not stored, whereas
@@ -257,5 +257,4 @@ inline std::ostream& operator<<(std::ostream& _str, GasMeter::GasConsumption con
 		return _str << std::dec << _consumption.value;
 }
 
-
 }

libevmasm/Instruction.cpp

@@ -76,7 +76,8 @@ std::map<std::string, Instruction> const solidity::evmasm::c_instructions =
 	{ "COINBASE", Instruction::COINBASE },
 	{ "TIMESTAMP", Instruction::TIMESTAMP },
 	{ "NUMBER", Instruction::NUMBER },
-	{ "DIFFICULTY", Instruction::DIFFICULTY },
+	{ "DIFFICULTY", Instruction::PREVRANDAO },
+	{ "PREVRANDAO", Instruction::PREVRANDAO },
 	{ "GASLIMIT", Instruction::GASLIMIT },
 	{ "CHAINID", Instruction::CHAINID },
 	{ "SELFBALANCE", Instruction::SELFBALANCE },
@@ -174,6 +175,7 @@ std::map<std::string, Instruction> const solidity::evmasm::c_instructions =
 	{ "SELFDESTRUCT", Instruction::SELFDESTRUCT }
 };
 
+/// @note InstructionInfo is assumed to be the same across all EVM versions except for the instruction name.
 static std::map<Instruction, InstructionInfo> const c_instructionInfo =
 { //												Add, Args, Ret, SideEffects, GasPriceTier
 	{ Instruction::STOP,		{ "STOP",			0, 0, 0, true,  Tier::Zero } },
@@ -223,7 +225,7 @@ static std::map<Instruction, InstructionInfo> const c_instructionInfo =
 	{ Instruction::COINBASE,	{ "COINBASE",		0, 0, 1, false, Tier::Base } },
 	{ Instruction::TIMESTAMP,	{ "TIMESTAMP",		0, 0, 1, false, Tier::Base } },
 	{ Instruction::NUMBER,		{ "NUMBER",			0, 0, 1, false, Tier::Base } },
-	{ Instruction::DIFFICULTY,	{ "DIFFICULTY",		0, 0, 1, false, Tier::Base } },
+	{ Instruction::PREVRANDAO,	{ "PREVRANDAO",		0, 0, 1, false, Tier::Base } },
 	{ Instruction::GASLIMIT,	{ "GASLIMIT",		0, 0, 1, false, Tier::Base } },
 	{ Instruction::CHAINID,		{ "CHAINID",		0, 0, 1, false, Tier::Base } },
 	{ Instruction::SELFBALANCE,	{ "SELFBALANCE",	0, 0, 1, false, Tier::Low } },
@@ -321,10 +323,12 @@ static std::map<Instruction, InstructionInfo> const c_instructionInfo =
 	{ Instruction::SELFDESTRUCT,	{ "SELFDESTRUCT",		0, 1, 0, true, Tier::Special } }
 };
 
-InstructionInfo solidity::evmasm::instructionInfo(Instruction _inst)
+InstructionInfo solidity::evmasm::instructionInfo(Instruction _inst, langutil::EVMVersion _evmVersion)
 {
 	try
 	{
+		if (_inst == Instruction::PREVRANDAO && _evmVersion < langutil::EVMVersion::paris())
+			return InstructionInfo({ "DIFFICULTY", 0, 0, 1, false, Tier::Base });
 		return c_instructionInfo.at(_inst);
 	}
 	catch (...)

libevmasm/Instruction.h

@@ -25,6 +25,7 @@
 #include <libevmasm/Exceptions.h>
 #include <libsolutil/Common.h>
 #include <libsolutil/Assertions.h>
+#include <liblangutil/EVMVersion.h>
 
 namespace solidity::evmasm
 {
@@ -83,7 +84,7 @@ enum class Instruction: uint8_t
 	COINBASE,			///< get the block's coinbase address
 	TIMESTAMP,			///< get the block's timestamp
 	NUMBER,				///< get the block's number
-	DIFFICULTY,			///< get the block's difficulty
+	PREVRANDAO,			///< get randomness provided by the beacon chain
 	GASLIMIT,			///< get the block's gas limit
 	CHAINID,			///< get the config's chainid param
 	SELFBALANCE,		///< get balance of the current account
@@ -306,7 +307,7 @@ struct InstructionInfo
 };
 
 /// Information on all the instructions.
-InstructionInfo instructionInfo(Instruction _inst);
+InstructionInfo instructionInfo(Instruction _inst, langutil::EVMVersion _evmVersion);
 
 /// check whether instructions exists.
 bool isValidInstruction(Instruction _inst);

libevmasm/KnownState.cpp

@@ -130,7 +130,9 @@ KnownState::StoreOperation KnownState::feedItem(AssemblyItem const& _item, bool
 	else
 	{
 		Instruction instruction = _item.instruction();
-		InstructionInfo info = instructionInfo(instruction);
+		// The latest EVMVersion is used here, since the InstructionInfo is assumed to be
+		// the same across all EVM versions except for the instruction name.
+		InstructionInfo info = instructionInfo(instruction, EVMVersion());
 		if (SemanticInformation::isDupInstruction(_item))
 			setStackElement(
 				m_stackHeight + 1,

libevmasm/PeepholeOptimiser.cpp

@@ -38,7 +38,7 @@ struct OptimiserState
 {
 	AssemblyItems const& items;
 	size_t i;
-	std::back_insert_iterator<AssemblyItems> out;
+	back_insert_iterator<AssemblyItems> out;
 };
 
 template<typename FunctionType>
@@ -53,7 +53,11 @@ template <class Method>
 struct SimplePeepholeOptimizerMethod
 {
 	template <size_t... Indices>
-	static bool applyRule(AssemblyItems::const_iterator _in, back_insert_iterator<AssemblyItems> _out, index_sequence<Indices...>)
+	static bool applyRule(
+		AssemblyItems::const_iterator _in,
+		back_insert_iterator<AssemblyItems> _out,
+		index_sequence<Indices...>
+	)
 	{
 		return Method::applySimple(_in[Indices]..., _out);
 	}
@@ -75,7 +79,10 @@ struct SimplePeepholeOptimizerMethod
 
 struct Identity: SimplePeepholeOptimizerMethod<Identity>
 {
-	static bool applySimple(AssemblyItem const& _item, std::back_insert_iterator<AssemblyItems> _out)
+	static bool applySimple(
+		AssemblyItem const& _item,
+		back_insert_iterator<AssemblyItems> _out
+	)
 	{
 		*_out = _item;
 		return true;
@@ -84,7 +91,11 @@ struct Identity: SimplePeepholeOptimizerMethod<Identity>
 
 struct PushPop: SimplePeepholeOptimizerMethod<PushPop>
 {
-	static bool applySimple(AssemblyItem const& _push, AssemblyItem const& _pop, std::back_insert_iterator<AssemblyItems>)
+	static bool applySimple(
+		AssemblyItem const& _push,
+		AssemblyItem const& _pop,
+		back_insert_iterator<AssemblyItems>
+	)
 	{
 		auto t = _push.type();
 		return _pop == Instruction::POP && (
@@ -100,15 +111,15 @@ struct OpPop: SimplePeepholeOptimizerMethod<OpPop>
 	static bool applySimple(
 		AssemblyItem const& _op,
 		AssemblyItem const& _pop,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (_pop == Instruction::POP && _op.type() == Operation)
 		{
 			Instruction instr = _op.instruction();
-			if (instructionInfo(instr).ret == 1 && !instructionInfo(instr).sideEffects)
+			if (instructionInfo(instr, langutil::EVMVersion()).ret == 1 && !instructionInfo(instr, langutil::EVMVersion()).sideEffects)
 			{
-				for (int j = 0; j < instructionInfo(instr).args; j++)
+				for (int j = 0; j < instructionInfo(instr, langutil::EVMVersion()).args; j++)
 					*_out = {Instruction::POP, _op.location()};
 				return true;
 			}
@@ -122,7 +133,7 @@ struct OpStop: SimplePeepholeOptimizerMethod<OpStop>
 	static bool applySimple(
 		AssemblyItem const& _op,
 		AssemblyItem const& _stop,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (_stop == Instruction::STOP)
@@ -130,7 +141,7 @@ struct OpStop: SimplePeepholeOptimizerMethod<OpStop>
 			if (_op.type() == Operation)
 			{
 				Instruction instr = _op.instruction();
-				if (!instructionInfo(instr).sideEffects)
+				if (!instructionInfo(instr, langutil::EVMVersion()).sideEffects)
 				{
 					*_out = {Instruction::STOP, _op.location()};
 					return true;
@@ -153,7 +164,7 @@ struct OpReturnRevert: SimplePeepholeOptimizerMethod<OpReturnRevert>
 		AssemblyItem const& _push,
 		AssemblyItem const& _pushOrDup,
 		AssemblyItem const& _returnRevert,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (
@@ -162,7 +173,7 @@ struct OpReturnRevert: SimplePeepholeOptimizerMethod<OpReturnRevert>
 			(_pushOrDup.type() == Push || _pushOrDup == dupInstruction(1))
 		)
 			if (
-				(_op.type() == Operation && !instructionInfo(_op.instruction()).sideEffects) ||
+				(_op.type() == Operation && !instructionInfo(_op.instruction(), langutil::EVMVersion()).sideEffects) ||
 				_op.type() == Push
 			)
 			{
@@ -177,7 +188,11 @@ struct OpReturnRevert: SimplePeepholeOptimizerMethod<OpReturnRevert>
 
 struct DoubleSwap: SimplePeepholeOptimizerMethod<DoubleSwap>
 {
-	static size_t applySimple(AssemblyItem const& _s1, AssemblyItem const& _s2, std::back_insert_iterator<AssemblyItems>)
+	static size_t applySimple(
+		AssemblyItem const& _s1,
+		AssemblyItem const& _s2,
+		back_insert_iterator<AssemblyItems>
+	)
 	{
 		return _s1 == _s2 && SemanticInformation::isSwapInstruction(_s1);
 	}
@@ -185,7 +200,11 @@ struct DoubleSwap: SimplePeepholeOptimizerMethod<DoubleSwap>
 
 struct DoublePush: SimplePeepholeOptimizerMethod<DoublePush>
 {
-	static bool applySimple(AssemblyItem const& _push1, AssemblyItem const& _push2, std::back_insert_iterator<AssemblyItems> _out)
+	static bool applySimple(
+		AssemblyItem const& _push1,
+		AssemblyItem const& _push2,
+		back_insert_iterator<AssemblyItems> _out
+	)
 	{
 		if (_push1.type() == Push && _push2.type() == Push && _push1.data() == _push2.data())
 		{
@@ -200,7 +219,11 @@ struct DoublePush: SimplePeepholeOptimizerMethod<DoublePush>
 
 struct CommutativeSwap: SimplePeepholeOptimizerMethod<CommutativeSwap>
 {
-	static bool applySimple(AssemblyItem const& _swap, AssemblyItem const& _op, std::back_insert_iterator<AssemblyItems> _out)
+	static bool applySimple(
+		AssemblyItem const& _swap,
+		AssemblyItem const& _op,
+		back_insert_iterator<AssemblyItems> _out
+	)
 	{
 		// Remove SWAP1 if following instruction is commutative
 		if (
@@ -218,7 +241,11 @@ struct CommutativeSwap: SimplePeepholeOptimizerMethod<CommutativeSwap>
 
 struct SwapComparison: SimplePeepholeOptimizerMethod<SwapComparison>
 {
-	static bool applySimple(AssemblyItem const& _swap, AssemblyItem const& _op, std::back_insert_iterator<AssemblyItems> _out)
+	static bool applySimple(
+		AssemblyItem const& _swap,
+		AssemblyItem const& _op,
+		back_insert_iterator<AssemblyItems> _out
+	)
 	{
 		static map<Instruction, Instruction> const swappableOps{
 			{ Instruction::LT, Instruction::GT },
@@ -247,7 +274,7 @@ struct DupSwap: SimplePeepholeOptimizerMethod<DupSwap>
 	static size_t applySimple(
 		AssemblyItem const& _dupN,
 		AssemblyItem const& _swapN,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (
@@ -272,7 +299,7 @@ struct IsZeroIsZeroJumpI: SimplePeepholeOptimizerMethod<IsZeroIsZeroJumpI>
 		AssemblyItem const& _iszero2,
 		AssemblyItem const& _pushTag,
 		AssemblyItem const& _jumpi,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (
@@ -298,7 +325,7 @@ struct EqIsZeroJumpI: SimplePeepholeOptimizerMethod<EqIsZeroJumpI>
 		AssemblyItem const& _iszero,
 		AssemblyItem const& _pushTag,
 		AssemblyItem const& _jumpi,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (
@@ -327,7 +354,7 @@ struct DoubleJump: SimplePeepholeOptimizerMethod<DoubleJump>
 		AssemblyItem const& _pushTag2,
 		AssemblyItem const& _jump,
 		AssemblyItem const& _tag1,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (
@@ -356,7 +383,7 @@ struct JumpToNext: SimplePeepholeOptimizerMethod<JumpToNext>
 		AssemblyItem const& _pushTag,
 		AssemblyItem const& _jump,
 		AssemblyItem const& _tag,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (
@@ -382,7 +409,7 @@ struct TagConjunctions: SimplePeepholeOptimizerMethod<TagConjunctions>
 		AssemblyItem const& _pushTag,
 		AssemblyItem const& _pushConstant,
 		AssemblyItem const& _and,
-		std::back_insert_iterator<AssemblyItems> _out
+		back_insert_iterator<AssemblyItems> _out
 	)
 	{
 		if (_and != Instruction::AND)
@@ -417,7 +444,7 @@ struct TruthyAnd: SimplePeepholeOptimizerMethod<TruthyAnd>
 		AssemblyItem const& _push,
 		AssemblyItem const& _not,
 		AssemblyItem const& _and,
-		std::back_insert_iterator<AssemblyItems>
+		back_insert_iterator<AssemblyItems>
 	)
 	{
 		return (
@@ -484,7 +511,7 @@ bool PeepholeOptimiser::optimise()
 {
 	// Avoid referencing immutables too early by using approx. counting in bytesRequired()
 	auto const approx = evmasm::Precision::Approximate;
-	OptimiserState state {m_items, 0, std::back_inserter(m_optimisedItems)};
+	OptimiserState state {m_items, 0, back_inserter(m_optimisedItems)};
 	while (state.i < m_items.size())
 		applyMethods(
 			state,

libevmasm/SemanticInformation.cpp

@@ -110,7 +110,7 @@ vector<SemanticInformation::Operation> SemanticInformation::readWriteOperations(
 	case Instruction::CALLCODE:
 	case Instruction::DELEGATECALL:
 	{
-		size_t paramCount = static_cast<size_t>(instructionInfo(_instruction).args);
+		size_t paramCount = static_cast<size_t>(instructionInfo(_instruction, langutil::EVMVersion()).args);
 		vector<Operation> operations{
 			Operation{Location::Memory, Effect::Read, paramCount - 4, paramCount - 3, {}},
 			Operation{Location::Storage, Effect::Read, {}, {}, {}}
@@ -178,7 +178,7 @@ bool SemanticInformation::breaksCSEAnalysisBlock(AssemblyItem const& _item, bool
 			return true; // GAS and PC assume a specific order of opcodes
 		if (_item.instruction() == Instruction::MSIZE)
 			return true; // msize is modified already by memory access, avoid that for now
-		InstructionInfo info = instructionInfo(_item.instruction());
+		InstructionInfo info = instructionInfo(_item.instruction(), langutil::EVMVersion());
 		if (_item.instruction() == Instruction::SSTORE)
 			return false;
 		if (_item.instruction() == Instruction::MSTORE)
@@ -318,7 +318,7 @@ bool SemanticInformation::movable(Instruction _instruction)
 	// These are not really functional.
 	if (isDupInstruction(_instruction) || isSwapInstruction(_instruction))
 		return false;
-	InstructionInfo info = instructionInfo(_instruction);
+	InstructionInfo info = instructionInfo(_instruction, langutil::EVMVersion());
 	if (info.sideEffects)
 		return false;
 	switch (_instruction)
@@ -345,7 +345,7 @@ bool SemanticInformation::canBeRemoved(Instruction _instruction)
 	// These are not really functional.
 	assertThrow(!isDupInstruction(_instruction) && !isSwapInstruction(_instruction), AssemblyException, "");
 
-	return !instructionInfo(_instruction).sideEffects;
+	return !instructionInfo(_instruction, langutil::EVMVersion()).sideEffects;
 }
 
 bool SemanticInformation::canBeRemovedIfNoMSize(Instruction _instruction)
@@ -483,7 +483,7 @@ bool SemanticInformation::invalidInPureFunctions(Instruction _instruction)
 	case Instruction::COINBASE:
 	case Instruction::TIMESTAMP:
 	case Instruction::NUMBER:
-	case Instruction::DIFFICULTY:
+	case Instruction::PREVRANDAO:
 	case Instruction::GASLIMIT:
 	case Instruction::STATICCALL:
 	case Instruction::SLOAD:

libevmasm/SimplificationRule.h

@@ -122,7 +122,7 @@ struct EVMBuiltins
 	static auto constexpr COINBASE = PatternGenerator<Instruction::COINBASE>{};
 	static auto constexpr TIMESTAMP = PatternGenerator<Instruction::TIMESTAMP>{};
 	static auto constexpr NUMBER = PatternGenerator<Instruction::NUMBER>{};
-	static auto constexpr DIFFICULTY = PatternGenerator<Instruction::DIFFICULTY>{};
+	static auto constexpr PREVRANDAO = PatternGenerator<Instruction::PREVRANDAO>{};
 	static auto constexpr GASLIMIT = PatternGenerator<Instruction::GASLIMIT>{};
 	static auto constexpr CHAINID = PatternGenerator<Instruction::CHAINID>{};
 	static auto constexpr SELFBALANCE = PatternGenerator<Instruction::SELFBALANCE>{};

libevmasm/SimplificationRules.cpp

@@ -141,7 +141,8 @@ string Pattern::toString() const
 	switch (m_type)
 	{
 	case Operation:
-		s << instructionInfo(m_instruction).name;
+		// Note: This function is exclusively used for debugging.
+		s << instructionInfo(m_instruction, EVMVersion()).name;
 		break;
 	case Push:
 		if (m_data)

liblangutil/EVMVersion.h

@@ -96,6 +96,7 @@ public:
 	bool hasChainID() const { return *this >= istanbul(); }
 	bool hasSelfBalance() const { return *this >= istanbul(); }
 	bool hasBaseFee() const { return *this >= london(); }
+	bool hasPrevRandao() const { return *this >= paris(); }
 
 	bool hasOpcode(evmasm::Instruction _opcode) const;
 

libsolidity/analysis/TypeChecker.cpp

@@ -3296,18 +3296,33 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 			(memberName == "min" ||	memberName == "max")
 		)
 			annotation.isPure = true;
-		else if (magicType->kind() == MagicType::Kind::Block && memberName == "chainid" && !m_evmVersion.hasChainID())
+		else if (magicType->kind() == MagicType::Kind::Block)
-			m_errorReporter.typeError(
+		{
-				3081_error,
+			if (memberName == "chainid" && !m_evmVersion.hasChainID())
-				_memberAccess.location(),
+				m_errorReporter.typeError(
-				"\"chainid\" is not supported by the VM version."
+					3081_error,
-			);
+					_memberAccess.location(),
-		else if (magicType->kind() == MagicType::Kind::Block && memberName == "basefee" && !m_evmVersion.hasBaseFee())
+					"\"chainid\" is not supported by the VM version."
-			m_errorReporter.typeError(
+				);
-				5921_error,
+			else if (memberName == "basefee" && !m_evmVersion.hasBaseFee())
-				_memberAccess.location(),
+				m_errorReporter.typeError(
-				"\"basefee\" is not supported by the VM version."
+					5921_error,
-			);
+					_memberAccess.location(),
+					"\"basefee\" is not supported by the VM version."
+				);
+			else if (memberName == "prevrandao" && !m_evmVersion.hasPrevRandao())
+				m_errorReporter.warning(
+					9432_error,
+					_memberAccess.location(),
+					"\"prevrandao\" is not supported by the VM version and will be treated as \"difficulty\"."
+				);
+			else if (memberName == "difficulty" && m_evmVersion.hasPrevRandao())
+				m_errorReporter.warning(
+					8417_error,
+					_memberAccess.location(),
+					"Since the VM version paris, \"difficulty\" was replaced by \"prevrandao\", which now returns a random number based on the beacon chain."
+				);
+		}
 	}
 
 	if (

libsolidity/ast/Types.cpp

@@ -4067,6 +4067,7 @@ MemberList::MemberMap MagicType::nativeMembers(ASTNode const*) const
 			{"timestamp", TypeProvider::uint256()},
 			{"blockhash", TypeProvider::function(strings{"uint"}, strings{"bytes32"}, FunctionType::Kind::BlockHash, StateMutability::View)},
 			{"difficulty", TypeProvider::uint256()},
+			{"prevrandao", TypeProvider::uint256()},
 			{"number", TypeProvider::uint256()},
 			{"gaslimit", TypeProvider::uint256()},
 			{"chainid", TypeProvider::uint256()},

libsolidity/codegen/CompilerContext.h

@@ -65,7 +65,7 @@ public:
 		RevertStrings _revertStrings,
 		CompilerContext* _runtimeContext = nullptr
 	):
-		m_asm(std::make_shared<evmasm::Assembly>(_runtimeContext != nullptr, std::string{})),
+		m_asm(std::make_shared<evmasm::Assembly>(_evmVersion, _runtimeContext != nullptr, std::string{})),
 		m_evmVersion(_evmVersion),
 		m_revertStrings(_revertStrings),
 		m_reservedMemory{0},

libsolidity/codegen/ExpressionCompiler.cpp

@@ -1808,8 +1808,8 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 			m_context << Instruction::COINBASE;
 		else if (member == "timestamp")
 			m_context << Instruction::TIMESTAMP;
-		else if (member == "difficulty")
+		else if (member == "difficulty" || member == "prevrandao")
-			m_context << Instruction::DIFFICULTY;
+			m_context << Instruction::PREVRANDAO;
 		else if (member == "number")
 			m_context << Instruction::NUMBER;
 		else if (member == "gaslimit")

libsolidity/codegen/ir/IRGeneratorForStatements.cpp

@@ -1822,8 +1822,13 @@ void IRGeneratorForStatements::endVisit(MemberAccess const& _memberAccess)
 			define(_memberAccess) << "coinbase()\n";
 		else if (member == "timestamp")
 			define(_memberAccess) << "timestamp()\n";
-		else if (member == "difficulty")
+		else if (member == "difficulty" || member == "prevrandao")
-			define(_memberAccess) << "difficulty()\n";
+		{
+			if (m_context.evmVersion().hasPrevRandao())
+				define(_memberAccess) << "prevrandao()\n";
+			else
+				define(_memberAccess) << "difficulty()\n";
+		}
 		else if (member == "number")
 			define(_memberAccess) << "number()\n";
 		else if (member == "gaslimit")

libsolidity/interface/StandardCompiler.cpp

@@ -381,6 +381,7 @@ Json::Value formatImmutableReferences(map<u256, pair<string, vector<size_t>>> co
 }
 
 Json::Value collectEVMObject(
+	langutil::EVMVersion _evmVersion,
 	evmasm::LinkerObject const& _object,
 	string const* _sourceMap,
 	Json::Value _generatedSources,
@@ -392,7 +393,7 @@ Json::Value collectEVMObject(
 	if (_artifactRequested("object"))
 		output["object"] = _object.toHex();
 	if (_artifactRequested("opcodes"))
-		output["opcodes"] = evmasm::disassemble(_object.bytecode);
+		output["opcodes"] = evmasm::disassemble(_object.bytecode, _evmVersion);
 	if (_artifactRequested("sourceMap"))
 		output["sourceMap"] = _sourceMap ? *_sourceMap : "";
 	if (_artifactRequested("functionDebugData"))
@@ -1328,6 +1329,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 			wildcardMatchesExperimental
 		))
 			evmData["bytecode"] = collectEVMObject(
+				_inputsAndSettings.evmVersion,
 				compilerStack.object(contractName),
 				compilerStack.sourceMapping(contractName),
 				compilerStack.generatedSources(contractName),
@@ -1349,6 +1351,7 @@ Json::Value StandardCompiler::compileSolidity(StandardCompiler::InputsAndSetting
 			wildcardMatchesExperimental
 		))
 			evmData["deployedBytecode"] = collectEVMObject(
+				_inputsAndSettings.evmVersion,
 				compilerStack.runtimeObject(contractName),
 				compilerStack.runtimeSourceMapping(contractName),
 				compilerStack.generatedSources(contractName, true),
@@ -1491,6 +1494,7 @@ Json::Value StandardCompiler::compileYul(InputsAndSettings _inputsAndSettings)
 			if (o.bytecode)
 				output["contracts"][sourceName][contractName]["evm"][kind] =
 					collectEVMObject(
+						_inputsAndSettings.evmVersion,
 						*o.bytecode,
 						o.sourceMappings.get(),
 						Json::arrayValue,

libyul/AsmAnalysis.cpp

@@ -119,7 +119,6 @@ vector<YulString> AsmAnalyzer::operator()(Literal const& _literal)
 			"Invalid type \"" + _literal.type.str() + "\" for literal \"" + _literal.value.str() + "\"."
 		);
 
-
 	return {_literal.type};
 }
 
@@ -619,7 +618,6 @@ Scope& AsmAnalyzer::scope(Block const* _block)
 void AsmAnalyzer::expectValidIdentifier(YulString _identifier, SourceLocation const& _location)
 {
 	// NOTE: the leading dot case is handled by the parser not allowing it.
-
 	if (boost::ends_with(_identifier.str(), "."))
 		m_errorReporter.syntaxError(
 			3384_error,
@@ -692,7 +690,7 @@ bool AsmAnalyzer::validateInstructions(evmasm::Instruction _instr, SourceLocatio
 			_location,
 			fmt::format(
 				"The \"{instruction}\" instruction is {kind} VMs (you are currently compiling for \"{version}\").",
-				fmt::arg("instruction", boost::to_lower_copy(instructionInfo(_instr).name)),
+				fmt::arg("instruction", boost::to_lower_copy(instructionInfo(_instr, m_evmVersion).name)),
 				fmt::arg("kind", vmKindMessage),
 				fmt::arg("version", m_evmVersion.name())
 			)

libyul/CompilabilityChecker.cpp

@@ -50,7 +50,7 @@ CompilabilityChecker::CompilabilityChecker(
 			builtinContext.subIDs[_object.name] = 1;
 		for (auto const& subNode: _object.subObjects)
 			builtinContext.subIDs[subNode->name] = 1;
-		NoOutputAssembly assembly;
+		NoOutputAssembly assembly{evmDialect->evmVersion()};
 		CodeTransform transform(
 			assembly,
 			analysisInfo,

libyul/YulStack.cpp

@@ -264,7 +264,7 @@ YulStack::assembleEVMWithDeployed(optional<string_view> _deployName) const
 	yulAssert(m_parserResult->code, "");
 	yulAssert(m_parserResult->analysisInfo, "");
 
-	evmasm::Assembly assembly(true, {});
+	evmasm::Assembly assembly(m_evmVersion, true, {});
 	EthAssemblyAdapter adapter(assembly);
 	compileEVM(adapter, m_optimiserSettings.optimizeStackAllocation);
 

libyul/backends/evm/AbstractAssembly.h

@@ -28,6 +28,7 @@
 #include <libsolutil/Common.h>
 #include <libsolutil/CommonData.h>
 #include <libsolutil/Numeric.h>
+#include <liblangutil/EVMVersion.h>
 
 #include <functional>
 #include <memory>

libyul/backends/evm/EVMDialect.cpp

@@ -47,11 +47,12 @@ namespace
 {
 
 pair<YulString, BuiltinFunctionForEVM> createEVMFunction(
+	langutil::EVMVersion _evmVersion,
 	string const& _name,
 	evmasm::Instruction _instruction
 )
 {
-	evmasm::InstructionInfo info = evmasm::instructionInfo(_instruction);
+	evmasm::InstructionInfo info = evmasm::instructionInfo(_instruction, _evmVersion);
 	BuiltinFunctionForEVM f;
 	f.name = YulString{_name};
 	f.parameters.resize(static_cast<size_t>(info.args));
@@ -119,11 +120,19 @@ set<YulString> createReservedIdentifiers(langutil::EVMVersion _evmVersion)
 		return _instr == evmasm::Instruction::BASEFEE && _evmVersion < langutil::EVMVersion::london();
 	};
 
+	// TODO remove this in 0.9.0. We allow creating functions or identifiers in Yul with the name
+	// prevrandao for VMs before paris.
+	auto prevRandaoException = [&](string const& _instrName) -> bool
+	{
+		// Using string comparison as the opcode is the same as for "difficulty"
+		return _instrName == "prevrandao" && _evmVersion < langutil::EVMVersion::paris();
+	};
+
 	set<YulString> reserved;
 	for (auto const& instr: evmasm::c_instructions)
 	{
 		string name = toLower(instr.first);
-		if (!baseFeeException(instr.second))
+		if (!baseFeeException(instr.second) && !prevRandaoException(name))
 			reserved.emplace(name);
 	}
 	reserved += vector<YulString>{
@@ -139,6 +148,13 @@ set<YulString> createReservedIdentifiers(langutil::EVMVersion _evmVersion)
 
 map<YulString, BuiltinFunctionForEVM> createBuiltins(langutil::EVMVersion _evmVersion, bool _objectAccess)
 {
+
+	// Exclude prevrandao as builtin for VMs before paris and difficulty for VMs after paris.
+	auto prevRandaoException = [&](string const& _instrName) -> bool
+	{
+		return (_instrName == "prevrandao" && _evmVersion < langutil::EVMVersion::paris()) || (_instrName == "difficulty" && _evmVersion >= langutil::EVMVersion::paris());
+	};
+
 	map<YulString, BuiltinFunctionForEVM> builtins;
 	for (auto const& instr: evmasm::c_instructions)
 	{
@@ -152,9 +168,10 @@ map<YulString, BuiltinFunctionForEVM> createBuiltins(langutil::EVMVersion _evmVe
 			opcode != evmasm::Instruction::JUMP &&
 			opcode != evmasm::Instruction::JUMPI &&
 			opcode != evmasm::Instruction::JUMPDEST &&
-			_evmVersion.hasOpcode(opcode)
+			_evmVersion.hasOpcode(opcode) &&
+			!prevRandaoException(name)
 		)
-			builtins.emplace(createEVMFunction(name, opcode));
+			builtins.emplace(createEVMFunction(_evmVersion, name, opcode));
 	}
 
 	if (_objectAccess)

libyul/backends/evm/EVMMetrics.cpp

@@ -88,7 +88,7 @@ void GasMeterVisitor::operator()(FunctionCall const& _funCall)
 
 void GasMeterVisitor::operator()(Literal const& _lit)
 {
-	m_runGas += evmasm::GasMeter::runGas(evmasm::Instruction::PUSH1);
+	m_runGas += evmasm::GasMeter::runGas(evmasm::Instruction::PUSH1, m_dialect.evmVersion());
 	m_dataGas +=
 		singleByteDataGas() +
 		evmasm::GasMeter::dataGas(
@@ -100,7 +100,7 @@ void GasMeterVisitor::operator()(Literal const& _lit)
 
 void GasMeterVisitor::operator()(Identifier const&)
 {
-	m_runGas += evmasm::GasMeter::runGas(evmasm::Instruction::DUP1);
+	m_runGas += evmasm::GasMeter::runGas(evmasm::Instruction::DUP1, m_dialect.evmVersion());
 	m_dataGas += singleByteDataGas();
 }
 
@@ -120,6 +120,6 @@ void GasMeterVisitor::instructionCostsInternal(evmasm::Instruction _instruction)
 		// Assumes that Keccak-256 is computed on a single word (rounded up).
 		m_runGas += evmasm::GasCosts::keccak256Gas + evmasm::GasCosts::keccak256WordGas;
 	else
-		m_runGas += evmasm::GasMeter::runGas(_instruction);
+		m_runGas += evmasm::GasMeter::runGas(_instruction, m_dialect.evmVersion());
 	m_dataGas += singleByteDataGas();
 }

libyul/backends/evm/EthAssemblyAdapter.cpp

@@ -124,7 +124,7 @@ void EthAssemblyAdapter::appendAssemblySize()
 
 pair<shared_ptr<AbstractAssembly>, AbstractAssembly::SubID> EthAssemblyAdapter::createSubAssembly(bool _creation, string _name)
 {
-	shared_ptr<evmasm::Assembly> assembly{make_shared<evmasm::Assembly>(_creation, std::move(_name))};
+	shared_ptr<evmasm::Assembly> assembly{make_shared<evmasm::Assembly>(m_assembly.evmVersion(), _creation, std::move(_name))};
 	auto sub = m_assembly.newSub(assembly);
 	return {make_shared<EthAssemblyAdapter>(*assembly), static_cast<size_t>(sub.data())};
 }

libyul/backends/evm/NoOutputAssembly.cpp

@@ -37,7 +37,7 @@ using namespace solidity::langutil;
 
 void NoOutputAssembly::appendInstruction(evmasm::Instruction _instr)
 {
-	m_stackHeight += instructionInfo(_instr).ret - instructionInfo(_instr).args;
+	m_stackHeight += instructionInfo(_instr, m_evmVersion).ret - instructionInfo(_instr, m_evmVersion).args;
 }
 
 void NoOutputAssembly::appendConstant(u256 const&)

libyul/backends/evm/NoOutputAssembly.h

@@ -45,7 +45,7 @@ namespace solidity::yul
 class NoOutputAssembly: public AbstractAssembly
 {
 public:
-	explicit NoOutputAssembly() { }
+	explicit NoOutputAssembly(langutil::EVMVersion _evmVersion): m_evmVersion(_evmVersion) { }
 	~NoOutputAssembly() override = default;
 
 	void setSourceLocation(langutil::SourceLocation const&) override {}
@@ -79,6 +79,7 @@ public:
 
 private:
 	int m_stackHeight = 0;
+	langutil::EVMVersion m_evmVersion;
 };
 
 

libyul/backends/evm/StackLayoutGenerator.cpp

@@ -747,23 +747,23 @@ void StackLayoutGenerator::fillInJunk(CFG::BasicBlock const& _block, CFG::Functi
 			if (_swapDepth > 16)
 				opGas += 1000;
 			else
-				opGas += evmasm::GasMeter::runGas(evmasm::swapInstruction(_swapDepth));
+				opGas += evmasm::GasMeter::runGas(evmasm::swapInstruction(_swapDepth), langutil::EVMVersion());
 		};
 		auto dupOrPush = [&](StackSlot const& _slot)
 		{
 			if (canBeFreelyGenerated(_slot))
-				opGas += evmasm::GasMeter::runGas(evmasm::pushInstruction(32));
+				opGas += evmasm::GasMeter::runGas(evmasm::pushInstruction(32), langutil::EVMVersion());
 			else
 			{
 				auto depth = util::findOffset(_source | ranges::views::reverse, _slot);
 				yulAssert(depth);
 				if (*depth < 16)
-					opGas += evmasm::GasMeter::runGas(evmasm::dupInstruction(static_cast<unsigned>(*depth + 1)));
+					opGas += evmasm::GasMeter::runGas(evmasm::dupInstruction(static_cast<unsigned>(*depth + 1)), langutil::EVMVersion());
 				else
 					opGas += 1000;
 			}
 		};
-		auto pop = [&]() { opGas += evmasm::GasMeter::runGas(evmasm::Instruction::POP); };
+		auto pop = [&]() { opGas += evmasm::GasMeter::runGas(evmasm::Instruction::POP,langutil::EVMVersion()); };
 		createStackLayout(_source, _target, swap, dupOrPush, pop);
 		return opGas;
 	};

libyul/optimiser/ExpressionSimplifier.cpp

@@ -47,7 +47,7 @@ void ExpressionSimplifier::visit(Expression& _expression)
 		m_dialect,
 		[this](YulString _var) { return variableValue(_var); }
 	))
-		_expression = match->action().toExpression(debugDataOf(_expression));
+		_expression = match->action().toExpression(debugDataOf(_expression), evmVersionFromDialect(m_dialect));
 
 	if (auto* functionCall = get_if<FunctionCall>(&_expression))
 		if (optional<evmasm::Instruction> instruction = toEVMInstruction(m_dialect, functionCall->functionName.name))

libyul/optimiser/KnowledgeBase.cpp

@@ -102,7 +102,7 @@ Expression KnowledgeBase::simplifyRecursively(Expression _expression)
 			arg = simplifyRecursively(arg);
 
 	if (auto match = SimplificationRules::findFirstMatch(_expression, m_dialect, m_variableValues))
-		return simplifyRecursively(match->action().toExpression(debugDataOf(_expression)));
+		return simplifyRecursively(match->action().toExpression(debugDataOf(_expression), langutil::EVMVersion()));
 
 	return _expression;
 }

libyul/optimiser/Metrics.cpp

@@ -20,6 +20,7 @@
 
 #include <libyul/optimiser/Metrics.h>
 #include <libyul/optimiser/OptimizerUtilities.h>
+#include <libyul/backends/evm/EVMDialect.h>
 
 #include <libyul/AST.h>
 #include <libyul/Exceptions.h>
@@ -180,7 +181,7 @@ void CodeCost::visit(Expression const& _expression)
 
 void CodeCost::addInstructionCost(evmasm::Instruction _instruction)
 {
-	evmasm::Tier gasPriceTier = evmasm::instructionInfo(_instruction).gasPriceTier;
+	evmasm::Tier gasPriceTier = evmasm::instructionInfo(_instruction, evmVersionFromDialect(m_dialect)).gasPriceTier;
 	if (gasPriceTier < evmasm::Tier::VeryLow)
 		m_cost -= 1;
 	else if (gasPriceTier < evmasm::Tier::High)

libyul/optimiser/OptimizerUtilities.cpp

@@ -58,6 +58,13 @@ optional<evmasm::Instruction> yul::toEVMInstruction(Dialect const& _dialect, Yul
 	return nullopt;
 }
 
+langutil::EVMVersion const yul::evmVersionFromDialect(Dialect const& _dialect)
+{
+	if (auto const* dialect = dynamic_cast<EVMDialect const*>(&_dialect))
+		return dialect->evmVersion();
+	return langutil::EVMVersion();
+}
+
 void StatementRemover::operator()(Block& _block)
 {
 	util::iterateReplacing(

libyul/optimiser/OptimizerUtilities.h

@@ -26,6 +26,7 @@
 #include <libyul/Dialect.h>
 #include <libyul/YulString.h>
 #include <libyul/optimiser/ASTWalker.h>
+#include <liblangutil/EVMVersion.h>
 
 #include <optional>
 
@@ -49,6 +50,10 @@ bool isRestrictedIdentifier(Dialect const& _dialect, YulString const& _identifie
 /// Helper function that returns the instruction, if the `_name` is a BuiltinFunction
 std::optional<evmasm::Instruction> toEVMInstruction(Dialect const& _dialect, YulString const& _name);
 
+/// Helper function that returns the EVM version from a dialect.
+/// It returns the default EVM version if dialect is not an EVMDialect.
+langutil::EVMVersion const evmVersionFromDialect(Dialect const& _dialect);
+
 class StatementRemover: public ASTModifier
 {
 public:

libyul/optimiser/SimplificationRules.cpp

@@ -235,7 +235,7 @@ evmasm::Instruction Pattern::instruction() const
 	return m_instruction;
 }
 
-Expression Pattern::toExpression(shared_ptr<DebugData const> const& _debugData) const
+Expression Pattern::toExpression(shared_ptr<DebugData const> const& _debugData, langutil::EVMVersion _evmVersion) const
 {
 	if (matchGroup())
 		return ASTCopier().translate(matchGroupValue());
@@ -248,9 +248,9 @@ Expression Pattern::toExpression(shared_ptr<DebugData const> const& _debugData)
 	{
 		vector<Expression> arguments;
 		for (auto const& arg: m_arguments)
-			arguments.emplace_back(arg.toExpression(_debugData));
+			arguments.emplace_back(arg.toExpression(_debugData, _evmVersion));
 
-		string name = util::toLower(instructionInfo(m_instruction).name);
+		string name = util::toLower(instructionInfo(m_instruction, _evmVersion).name);
 
 		return FunctionCall{_debugData,
 			Identifier{_debugData, YulString{name}},

libyul/optimiser/SimplificationRules.h

@@ -131,7 +131,7 @@ public:
 
 	/// Turns this pattern into an actual expression. Should only be called
 	/// for patterns resulting from an action, i.e. with match groups assigned.
-	Expression toExpression(std::shared_ptr<DebugData const> const& _debugData) const;
+	Expression toExpression(std::shared_ptr<DebugData const> const& _debugData, langutil::EVMVersion _evmVersion) const;
 
 private:
 	Expression const& matchGroupValue() const;

scripts/check_style.sh

@@ -5,9 +5,10 @@ set -eu
 ERROR_LOG="$(mktemp -t check_style_XXXXXX.log)"
 
 EXCLUDE_FILES=(
+    # The line below is left unquoted to allow the shell globbing path expansion
+    test/cmdlineTests/*/{err,output}
     "libsolutil/picosha2.h"
     "test/cmdlineTests/strict_asm_only_cr/input.yul"
-    "test/cmdlineTests/strict_asm_only_cr/err"
     "test/libsolutil/UTF8.cpp"
     "test/libsolidity/syntaxTests/license/license_cr_endings.sol"
     "test/libsolidity/syntaxTests/license/license_crlf_endings.sol"

scripts/test_antlr_grammar.sh

@@ -121,6 +121,9 @@ done < <(
       grep -v -E 'revertStatement/non_called.sol' |
       # Skipping a test with "let basefee := ..."
       grep -v -E 'inlineAssembly/basefee_berlin_function.sol' |
+      # Skipping tests with "let prevrandao := ..."
+      grep -v -E 'inlineAssembly/prevrandao_allowed_function_pre_paris.sol' |
+      grep -v -E 'inlineAssembly/prevrandao_disallowed_function_post_paris.sol' |
       # Skipping license error, unrelated to the grammar
       grep -v -E 'license/license_double5.sol' |
       grep -v -E 'license/license_hidden_unicode.sol' |

solc/CommandLineInterface.cpp

@@ -198,11 +198,11 @@ void CommandLineInterface::handleOpcode(string const& _contract)
 	solAssert(CompilerInputModes.count(m_options.input.mode) == 1);
 
 	if (!m_options.output.dir.empty())
-		createFile(m_compiler->filesystemFriendlyName(_contract) + ".opcode", evmasm::disassemble(m_compiler->object(_contract).bytecode));
+		createFile(m_compiler->filesystemFriendlyName(_contract) + ".opcode", evmasm::disassemble(m_compiler->object(_contract).bytecode, m_options.output.evmVersion));
 	else
 	{
 		sout() << "Opcodes:" << endl;
-		sout() << std::uppercase << evmasm::disassemble(m_compiler->object(_contract).bytecode);
+		sout() << std::uppercase << evmasm::disassemble(m_compiler->object(_contract).bytecode, m_options.output.evmVersion);
 		sout() << endl;
 	}
 }
@@ -825,7 +825,7 @@ void CommandLineInterface::handleCombinedJSON()
 		if (m_options.compiler.combinedJsonRequests->binaryRuntime && m_compiler->compilationSuccessful())
 			contractData[g_strBinaryRuntime] = m_compiler->runtimeObject(contractName).toHex();
 		if (m_options.compiler.combinedJsonRequests->opcodes && m_compiler->compilationSuccessful())
-			contractData[g_strOpcodes] = evmasm::disassemble(m_compiler->object(contractName).bytecode);
+			contractData[g_strOpcodes] = evmasm::disassemble(m_compiler->object(contractName).bytecode, m_options.output.evmVersion);
 		if (m_options.compiler.combinedJsonRequests->asm_ && m_compiler->compilationSuccessful())
 			contractData[g_strAsm] = m_compiler->assemblyJSON(contractName);
 		if (m_options.compiler.combinedJsonRequests->storageLayout && m_compiler->compilationSuccessful())

test/cmdlineTests/evmasm_difficulty_post_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version paris

test/cmdlineTests/evmasm_difficulty_post_paris/err

@@ -0,0 +1,5 @@
+Warning: Since the VM version paris, "difficulty" was replaced by "prevrandao", which now returns a random number based on the beacon chain.
+ --> evmasm_difficulty_post_paris/input.sol:6:21:
+  |
+6 |         uint256 x = block.difficulty;
+  |                     ^^^^^^^^^^^^^^^^

test/cmdlineTests/evmasm_difficulty_post_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.difficulty;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_difficulty_post_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_difficulty_post_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, prevrandao)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+PREVRANDAO PUSH1 0x0 SSTORE STOP INVALID 

test/cmdlineTests/evmasm_difficulty_pre_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version london

test/cmdlineTests/evmasm_difficulty_pre_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.difficulty;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_difficulty_pre_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_difficulty_pre_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, difficulty)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+DIFFICULTY PUSH1 0x0 SSTORE STOP INVALID 

test/cmdlineTests/evmasm_prevrandao_post_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version paris

test/cmdlineTests/evmasm_prevrandao_post_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.prevrandao;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_prevrandao_post_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_prevrandao_post_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, prevrandao)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+PREVRANDAO PUSH1 0x0 SSTORE STOP INVALID 

test/cmdlineTests/evmasm_prevrandao_pre_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version london

test/cmdlineTests/evmasm_prevrandao_pre_paris/err

@@ -0,0 +1,5 @@
+Warning: "prevrandao" is not supported by the VM version and will be treated as "difficulty".
+ --> evmasm_prevrandao_pre_paris/input.sol:6:21:
+  |
+6 |         uint256 x = block.prevrandao;
+  |                     ^^^^^^^^^^^^^^^^

test/cmdlineTests/evmasm_prevrandao_pre_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.prevrandao;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_prevrandao_pre_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_prevrandao_pre_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, difficulty)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+DIFFICULTY PUSH1 0x0 SSTORE STOP INVALID 

test/libevmasm/Assembler.cpp

@@ -20,6 +20,7 @@
  * @date 2018
  * Tests for the assembler.
  */
+#include <test/Common.h>
 
 #include <libevmasm/Assembly.h>
 #include <libsolutil/JSON.h>
@@ -59,15 +60,16 @@ BOOST_AUTO_TEST_CASE(all_assembly_items)
 		{ "sub.asm", 1 },
 		{ "verbatim.asm", 2 }
 	};
-	Assembly _assembly{false, {}};
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	Assembly _assembly{evmVersion, false, {}};
 	auto root_asm = make_shared<string>("root.asm");
 	_assembly.setSourceLocation({1, 3, root_asm});
 
-	Assembly _subAsm{false, {}};
+	Assembly _subAsm{evmVersion, false, {}};
 	auto sub_asm = make_shared<string>("sub.asm");
 	_subAsm.setSourceLocation({6, 8, sub_asm});
 
-	Assembly _verbatimAsm(true, "");
+	Assembly _verbatimAsm(evmVersion, true, "");
 	auto verbatim_asm = make_shared<string>("verbatim.asm");
 	_verbatimAsm.setSourceLocation({8, 18, verbatim_asm});
 
@@ -215,6 +217,7 @@ BOOST_AUTO_TEST_CASE(all_assembly_items)
 
 BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 {
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
 	// Tests for 1, 2, 3 number of immutables.
 	for (int numImmutables = 1; numImmutables <= 3; ++numImmutables)
 	{
@@ -243,7 +246,7 @@ BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 				{ *subName, 1 }
 			};
 
-			auto subAsm = make_shared<Assembly>(false, string{});
+			auto subAsm = make_shared<Assembly>(evmVersion, false, string{});
 			for (char i = 0; i < numImmutables; ++i)
 			{
 				for (int r = 0; r < numActualRefs; ++r)
@@ -253,7 +256,7 @@ BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 				}
 			}
 
-			Assembly assembly{true, {}};
+			Assembly assembly{evmVersion, true, {}};
 			for (char i = 1; i <= numImmutables; ++i)
 			{
 				assembly.setSourceLocation({10*i, 10*i + 3+i, assemblyName});
@@ -270,7 +273,7 @@ BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 			auto const numberOfMappings = std::count(sourceMappings.begin(), sourceMappings.end(), ';');
 
 			LinkerObject const& obj = assembly.assemble();
-			string const disassembly = disassemble(obj.bytecode, "\n");
+			string const disassembly = disassemble(obj.bytecode, evmVersion, "\n");
 			auto const numberOfOpcodes = std::count(disassembly.begin(), disassembly.end(), '\n');
 
 			#if 0 // {{{ debug prints
@@ -302,11 +305,12 @@ BOOST_AUTO_TEST_CASE(immutable)
 		{ "root.asm", 0 },
 		{ "sub.asm", 1 }
 	};
-	Assembly _assembly{true, {}};
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	Assembly _assembly{evmVersion, true, {}};
 	auto root_asm = make_shared<string>("root.asm");
 	_assembly.setSourceLocation({1, 3, root_asm});
 
-	Assembly _subAsm{false, {}};
+	Assembly _subAsm{evmVersion, false, {}};
 	auto sub_asm = make_shared<string>("sub.asm");
 	_subAsm.setSourceLocation({6, 8, sub_asm});
 	_subAsm.appendImmutable("someImmutable");
@@ -395,10 +399,11 @@ BOOST_AUTO_TEST_CASE(immutable)
 
 BOOST_AUTO_TEST_CASE(subobject_encode_decode)
 {
-	Assembly assembly{true, {}};
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	Assembly assembly{evmVersion, true, {}};
 
-	shared_ptr<Assembly> subAsmPtr = make_shared<Assembly>(false, string{});
+	shared_ptr<Assembly> subAsmPtr = make_shared<Assembly>(evmVersion, false, string{});
-	shared_ptr<Assembly> subSubAsmPtr = make_shared<Assembly>(false, string{});
+	shared_ptr<Assembly> subSubAsmPtr = make_shared<Assembly>(evmVersion, false, string{});
 
 	assembly.appendSubroutine(subAsmPtr);
 	subAsmPtr->appendSubroutine(subSubAsmPtr);

test/libevmasm/Optimiser.cpp

@@ -1250,8 +1250,18 @@ BOOST_AUTO_TEST_CASE(jumpdest_removal_subassemblies)
 	// tag unifications (due to block deduplication) is also
 	// visible at the super-assembly.
 
-	Assembly main{false, {}};
+	Assembly::OptimiserSettings settings;
-	AssemblyPointer sub = make_shared<Assembly>(true, string{});
+	settings.runInliner = false;
+	settings.runJumpdestRemover = true;
+	settings.runPeephole = true;
+	settings.runDeduplicate = true;
+	settings.runCSE = true;
+	settings.runConstantOptimiser = true;
+	settings.evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	settings.expectedExecutionsPerDeployment = OptimiserSettings{}.expectedExecutionsPerDeployment;
+
+	Assembly main{settings.evmVersion, false, {}};
+	AssemblyPointer sub = make_shared<Assembly>(settings.evmVersion, true, string{});
 
 	sub->append(u256(1));
 	auto t1 = sub->newTag();
@@ -1277,16 +1287,6 @@ BOOST_AUTO_TEST_CASE(jumpdest_removal_subassemblies)
 	main.append(t1.toSubAssemblyTag(subId));
 	main.append(u256(8));
 
-	Assembly::OptimiserSettings settings;
-	settings.runInliner = false;
-	settings.runJumpdestRemover = true;
-	settings.runPeephole = true;
-	settings.runDeduplicate = true;
-	settings.runCSE = true;
-	settings.runConstantOptimiser = true;
-	settings.evmVersion = solidity::test::CommonOptions::get().evmVersion();
-	settings.expectedExecutionsPerDeployment = OptimiserSettings{}.expectedExecutionsPerDeployment;
-
 	main.optimise(settings);
 
 	AssemblyItems expectationMain{

test/libsolidity/SolidityOptimizer.cpp

@@ -109,7 +109,7 @@ public:
 		bytes realCode = bytecodeSansMetadata(_bytecode);
 		BOOST_REQUIRE_MESSAGE(!realCode.empty(), "Invalid or missing metadata in bytecode.");
 		size_t instructions = 0;
-		evmasm::eachInstruction(realCode, [&](Instruction _instr, u256 const&) {
+		evmasm::eachInstruction(realCode, m_evmVersion, [&](Instruction _instr, u256 const&) {
 			if (!_which || *_which == _instr)
 				instructions++;
 		});
@@ -287,7 +287,7 @@ BOOST_AUTO_TEST_CASE(retain_information_in_branches)
 
 	bytes optimizedBytecode = compileAndRunWithOptimizer(sourceCode, 0, "c", true);
 	size_t numSHA3s = 0;
-	eachInstruction(optimizedBytecode, [&](Instruction _instr, u256 const&) {
+	eachInstruction(optimizedBytecode, m_evmVersion, [&](Instruction _instr, u256 const&) {
 		if (_instr == Instruction::KECCAK256)
 			numSHA3s++;
 	});
@@ -330,7 +330,7 @@ BOOST_AUTO_TEST_CASE(store_tags_as_unions)
 
 	bytes optimizedBytecode = compileAndRunWithOptimizer(sourceCode, 0, "test", true);
 	size_t numSHA3s = 0;
-	eachInstruction(optimizedBytecode, [&](Instruction _instr, u256 const&) {
+	eachInstruction(optimizedBytecode, m_evmVersion, [&](Instruction _instr, u256 const&) {
 		if (_instr == Instruction::KECCAK256)
 			numSHA3s++;
 	});

test/libsolidity/analysis/FunctionCallGraph.cpp

@@ -1860,6 +1860,7 @@ BOOST_AUTO_TEST_CASE(builtins)
 				block.chainid;
 				block.coinbase;
 				block.difficulty;
+				block.prevrandao;
 				block.gaslimit;
 				block.number;
 				block.timestamp;

test/libsolidity/semanticTests/inlineAssembly/difficulty.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public view returns (uint ret) {
+        assembly {
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: <paris
+// ----
+// f() -> 200000000

test/libsolidity/semanticTests/inlineAssembly/prevrandao.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public view returns (uint ret) {
+        assembly {
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: >=paris
+// ----
+// f() -> 0xa86c2e601b6c44eb4848f7d23d9df3113fbcac42041c49cbed5000cb4f118777

test/libsolidity/semanticTests/state/block_prevrandao.sol

@@ -0,0 +1,10 @@
+contract C {
+    function f() public view returns (uint) {
+        return block.prevrandao;
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: >=paris
+// ----
+// f() -> 0xa86c2e601b6c44eb4848f7d23d9df3113fbcac42041c49cbed5000cb4f118777

test/libsolidity/semanticTests/state/block_prevrandao_pre_paris.sol

@@ -0,0 +1,10 @@
+contract C {
+    function f() public view returns (uint) {
+        return block.prevrandao;
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: <paris
+// ----
+// f() -> 200000000

test/libsolidity/syntaxTests/inlineAssembly/difficulty_builtin_pre_paris.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.difficulty;
+    }
+
+    function g() public view returns (uint256 ret) {
+        assembly {
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----

test/libsolidity/syntaxTests/inlineAssembly/difficulty_disallowed_function_pre_paris.sol

@@ -0,0 +1,21 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let difficulty := sload(0)
+            ret := difficulty
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function difficulty() -> r {
+                r := 1000
+            }
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----
+// ParserError 5568: (101-111): Cannot use builtin function name "difficulty" as identifier name.

test/libsolidity/syntaxTests/inlineAssembly/difficulty_magic_block_warn_post_paris.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.difficulty;
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// Warning 8417: (77-93): Since the VM version paris, "difficulty" was replaced by "prevrandao", which now returns a random number based on the beacon chain.

test/libsolidity/syntaxTests/inlineAssembly/difficulty_nobuiltin_post_paris.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public {
+        assembly {
+            pop(difficulty())
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// DeclarationError 4619: (74-84): Function "difficulty" not found.
+// TypeError 3950: (74-86): Expected expression to evaluate to one value, but got 0 values instead.

test/libsolidity/syntaxTests/inlineAssembly/difficulty_reserved_post_paris.sol

@@ -0,0 +1,22 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let difficulty := sload(0)
+            ret := difficulty
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function difficulty() -> r {
+                r := 1000
+            }
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// DeclarationError 5017: (101-111): The identifier "difficulty" is reserved and can not be used.
+// DeclarationError 5017: (255-323): The identifier "difficulty" is reserved and can not be used.

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_allowed_function_pre_paris.sol

@@ -0,0 +1,20 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let prevrandao := sload(0)
+            ret := prevrandao
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function prevrandao() -> r {
+                r := 1000
+            }
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_builtin_post_paris.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.prevrandao;
+    }
+
+    function g() public view returns (uint256 ret) {
+        assembly {
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_disallowed_function_post_paris.sol

@@ -0,0 +1,21 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let prevrandao := sload(0)
+            ret := prevrandao
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function prevrandao() -> r {
+                r := 1000
+            }
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// ParserError 5568: (101-111): Cannot use builtin function name "prevrandao" as identifier name.

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_magic_block_warn_pre_paris.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.prevrandao;
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----
+// Warning 9432: (77-93): "prevrandao" is not supported by the VM version and will be treated as "difficulty".

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_nobuitin_pre_paris.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public {
+        assembly {
+            pop(prevrandao())
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----
+// DeclarationError 4619: (74-84): Function "prevrandao" not found.
+// TypeError 3950: (74-86): Expected expression to evaluate to one value, but got 0 values instead.

test/libsolidity/syntaxTests/tryCatch/low_level_homestead.sol

@@ -8,6 +8,6 @@ contract C {
     }
 }
 // ====
-// EVMVersion: <byzantium
+// EVMVersion: =homestead
 // ----
 // TypeError 9908: (73-106): This catch clause type cannot be used on the selected EVM version (homestead). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/low_level_spuriousDragon.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch (bytes memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =spuriousDragon
+// ----
+// TypeError 9908: (73-106): This catch clause type cannot be used on the selected EVM version (spuriousDragon). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/low_level_tangerineWhistle.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch (bytes memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =tangerineWhistle
+// ----
+// TypeError 9908: (73-106): This catch clause type cannot be used on the selected EVM version (tangerineWhistle). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/structured_homestead.sol

@@ -8,6 +8,6 @@ contract C {
     }
 }
 // ====
-// EVMVersion: <byzantium
+// EVMVersion: =homestead
 // ----
 // TypeError 1812: (73-112): This catch clause type cannot be used on the selected EVM version (homestead). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/structured_spuriousDragon.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch Error(string memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =spuriousDragon
+// ----
+// TypeError 1812: (73-112): This catch clause type cannot be used on the selected EVM version (spuriousDragon). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/structured_tangerineWhistle.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch Error(string memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =tangerineWhistle
+// ----
+// TypeError 1812: (73-112): This catch clause type cannot be used on the selected EVM version (tangerineWhistle). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/types/magic_block_istanbul.sol

@@ -3,15 +3,12 @@ contract C {
         return block.coinbase;
     }
     function g() public view returns (uint) {
-        return block.difficulty;
-    }
-    function h() public view returns (uint) {
         return block.gaslimit;
     }
-    function i() public view returns (uint) {
+    function h() public view returns (uint) {
         return block.timestamp;
     }
-    function j() public view returns (uint) {
+    function i() public view returns (uint) {
         return block.chainid;
     }
 }

test/libsolidity/syntaxTests/types/magic_block_paris.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public view returns (uint) {
+        return block.prevrandao;
+    }
+    function g() public view returns (uint ret) {
+        assembly {
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed.sol

@@ -73,7 +73,7 @@ contract C {
             pop(coinbase())
             pop(timestamp())
             pop(number())
-            pop(difficulty())
+            pop(prevrandao())
             pop(gaslimit())
 
             // NOTE: msize() is allowed only with optimizer disabled
@@ -83,7 +83,7 @@ contract C {
     }
 }
 // ====
-// EVMVersion: >=london
+// EVMVersion: >=paris
 // ----
 // Warning 5740: (89-1716): Unreachable code.
 // Warning 5740: (1729-1741): Unreachable code.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_london.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public {
+        assembly {
+            pop(difficulty())
+        }
+    }
+}
+// ====
+// EVMVersion: <=london
+// ----
+// Warning 2018: (17-103): Function state mutability can be restricted to view

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_pure.sol

@@ -73,7 +73,6 @@ contract C {
             //pop(coinbase())
             //pop(timestamp())
             //pop(number())
-            //pop(difficulty())
             //pop(gaslimit())
 
             // NOTE: msize() is allowed only with optimizer disabled

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_view.sol

@@ -73,7 +73,7 @@ contract C {
             pop(coinbase())
             pop(timestamp())
             pop(number())
-            pop(difficulty())
+            pop(prevrandao())
             pop(gaslimit())
 
             // NOTE: msize() is allowed only with optimizer disabled
@@ -83,7 +83,7 @@ contract C {
     }
 }
 // ====
-// EVMVersion: >=london
+// EVMVersion: >=paris
 // ----
 // Warning 5740: (94-1733): Unreachable code.
 // Warning 5740: (1746-1758): Unreachable code.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_view_london.sol

@@ -0,0 +1,10 @@
+contract C {
+    function f() public view {
+        assembly {
+            pop(difficulty())
+        }
+    }
+}
+// ====
+// EVMVersion: <=london
+// ----

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure.sol

@@ -6,33 +6,26 @@ contract C {
             pop(gas())
             pop(address())
             pop(balance(0))
-            pop(selfbalance())
             pop(caller())
             pop(callvalue())
             pop(extcodesize(0))
             extcodecopy(0, 1, 2, 3)
-            pop(extcodehash(0))
             pop(create(0, 1, 2))
-            pop(create2(0, 1, 2, 3))
             pop(call(0, 1, 2, 3, 4, 5, 6))
             pop(callcode(0, 1, 2, 3, 4, 5, 6))
             pop(delegatecall(0, 1, 2, 3, 4, 5))
-            pop(staticcall(0, 1, 2, 3, 4, 5))
             selfdestruct(0)
             log0(0, 1)
             log1(0, 1, 2)
             log2(0, 1, 2, 3)
             log3(0, 1, 2, 3, 4)
             log4(0, 1, 2, 3, 4, 5)
-            pop(chainid())
-            pop(basefee())
             pop(origin())
             pop(gasprice())
             pop(blockhash(0))
             pop(coinbase())
             pop(timestamp())
             pop(number())
-            pop(difficulty())
             pop(gaslimit())
 
             // These two are disallowed too but the error suppresses other errors.
@@ -41,40 +34,31 @@ contract C {
         }
     }
 }
-// ====
-// EVMVersion: >=london
 // ----
-// Warning 5740: (672-1083): Unreachable code.
+// Warning 5740: (526-853): Unreachable code.
 // TypeError 2527: (79-87): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
 // TypeError 8961: (101-113): Function cannot be declared as pure because this expression (potentially) modifies the state.
 // TypeError 2527: (130-135): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
 // TypeError 2527: (153-162): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
 // TypeError 2527: (180-190): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (208-221): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (208-216): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (239-247): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (234-245): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (265-276): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (263-277): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (294-308): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (291-314): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (322-345): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (331-346): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 2527: (362-376): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (364-389): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (394-409): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (407-436): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (427-446): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (454-484): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (464-489): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (498-513): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (507-536): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (526-536): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (554-584): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (549-562): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 2527: (602-630): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (575-591): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (644-659): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (604-623): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (672-682): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (636-658): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (695-708): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (675-683): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 8961: (721-737): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (701-711): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 8961: (750-769): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (729-741): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 8961: (782-804): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (759-769): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (821-830): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (787-798): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (848-857): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (816-824): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (875-883): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (842-852): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (901-911): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (929-941): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (959-969): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (987-998): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (1016-1024): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (1042-1054): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (1072-1082): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_byzantium.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(staticcall(0, 1, 2, 3, 4, 5))
+        }
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// ----
+// TypeError 2527: (79-107): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_constantinople.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(extcodehash(0))
+            pop(create2(0, 1, 2, 3))
+        }
+    }
+}
+// ====
+// EVMVersion: >=constantinople
+// ----
+// TypeError 2527: (79-93): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (111-130): Function cannot be declared as pure because this expression (potentially) modifies the state.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_istanbul.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(selfbalance())
+            pop(chainid())
+        }
+    }
+}
+// ====
+// EVMVersion: >=istanbul
+// ----
+// TypeError 2527: (79-92): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (110-119): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_london.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(basefee())
+        }
+    }
+}
+// ====
+// EVMVersion: >=london
+// ----
+// TypeError 2527: (79-88): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".