Consider extcodehash as part of Constantinople

Author: axic

Changelog.md

@@ -4,6 +4,7 @@ Language Features:
 
 
 Compiler Features:
+ * Inline Assembly: Consider ``extcodehash`` as part of Constantinople.
  * SMTChecker: Do not report underflow/overflow if they always revert. This removes false positives when using ``SafeMath``.
  * Static Analyzer: Warn about expressions with custom types when they have no effect.
  * Optimizer: Add rule for shifts with constants for Constantinople.

liblangutil/EVMVersion.h

@@ -74,6 +74,7 @@ class EVMVersion:
 	bool hasStaticCall() const { return *this >= byzantium(); }
 	bool hasBitwiseShifting() const { return *this >= constantinople(); }
 	bool hasCreate2() const { return *this >= constantinople(); }
+	bool hasExtCodeHash() const { return *this >= constantinople(); }
 
 	/// Whether we have to retain the costs for the call opcode itself (false),
 	/// or whether we can just forward easily all remaining gas (true).

libyul/AsmAnalysis.cpp

@@ -655,19 +655,7 @@ void AsmAnalyzer::warnOnInstructions(solidity::Instruction _instr, SourceLocatio
 		);
 	};
 
-	if (_instr == solidity::Instruction::EXTCODEHASH)
-	{
-		m_errorReporter.warning(
-			_location,
-			"The \"" +
-			boost::to_lower_copy(instructionInfo(_instr).name)
-			+ "\" instruction is not supported by the VM version \"" +
-			"" + m_evmVersion.name() +
-			"\" you are currently compiling for. " +
-			"It will be interpreted as an invalid instruction on this VM."
-		);
-	}
-	else if ((
+	if ((
 		_instr == solidity::Instruction::RETURNDATACOPY ||
 		_instr == solidity::Instruction::RETURNDATASIZE
 	) && !m_evmVersion.supportsReturndata())
@@ -690,6 +678,10 @@ void AsmAnalyzer::warnOnInstructions(solidity::Instruction _instr, SourceLocatio
 	{
 		warningForVM("only available for Constantinople-compatible");
 	}
+	else if (_instr == solidity::Instruction::EXTCODEHASH && !m_evmVersion.hasExtCodeHash())
+	{
+		warningForVM("only available for Constantinople-compatible");
+	}
 	else if (_instr == solidity::Instruction::JUMP || _instr == solidity::Instruction::JUMPI || _instr == solidity::Instruction::JUMPDEST)
 	{
 		if (m_dialect->flavour == AsmFlavour::Loose)

test/libsolidity/SolidityNameAndTypeResolution.cpp

@@ -417,10 +417,12 @@ BOOST_AUTO_TEST_CASE(extcodehash_as_variable)
 	)";
 	// This needs special treatment, because the message mentions the EVM version,
 	// so cannot be run via isoltest.
-	CHECK_ALLOW_MULTI(text, (std::vector<std::pair<Error::Type, std::string>>{
-		{Error::Type::Warning, "Variable is shadowed in inline assembly by an instruction of the same name"},
-		{Error::Type::Warning, "The \"extcodehash\" instruction is not supported by the VM version"},
-	}));
+	vector<pair<Error::Type, std::string>> expectations(vector<pair<Error::Type, std::string>>{
+		{Error::Type::Warning, "Variable is shadowed in inline assembly by an instruction of the same name"}
+	});
+	if (!dev::test::Options::get().evmVersion().hasExtCodeHash())
+		expectations.emplace_back(make_pair(Error::Type::Warning, std::string("\"extcodehash\" instruction is only available for Constantinople-compatible VMs.")));
+	CHECK_ALLOW_MULTI(text, expectations);
 }
 
 BOOST_AUTO_TEST_CASE(getter_is_memory_type)