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>

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())
-			m_errorReporter.typeError(
-				3081_error,
-				_memberAccess.location(),
-				"\"chainid\" is not supported by the VM version."
-			);
-		else if (magicType->kind() == MagicType::Kind::Block && memberName == "basefee" && !m_evmVersion.hasBaseFee())
-			m_errorReporter.typeError(
-				5921_error,
-				_memberAccess.location(),
-				"\"basefee\" is not supported by the VM version."
-			);
+		else if (magicType->kind() == MagicType::Kind::Block)
+		{
+			if (memberName == "chainid" && !m_evmVersion.hasChainID())
+				m_errorReporter.typeError(
+					3081_error,
+					_memberAccess.location(),
+					"\"chainid\" is not supported by the VM version."
+				);
+			else if (memberName == "basefee" && !m_evmVersion.hasBaseFee())
+				m_errorReporter.typeError(
+					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")
-			m_context << Instruction::DIFFICULTY;
+		else if (member == "difficulty" || member == "prevrandao")
+			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")
-			define(_memberAccess) << "difficulty()\n";
+		else if (member == "difficulty" || member == "prevrandao")
+		{
+			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,