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>

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;