[Lity] Add rand built-in function to get an uint random numbe…

…r from the virtual machiine.

- Add a new opcode ``rand`` at 0xf9.
- Update syntax highlight for ``rand``.

Changelog.md

@@ -5,6 +5,7 @@ Features:
 
 Language Features:
  * General: Add a new modifier ``freegas``, which allows developers to use contract balance to pay the transaction fee for the users.
+ * General: Add a new built-in function ``rand`` to get an ``uint`` random number from the virtual machine.
 
 ### Lity 1.2.6 (2018-12-07)
 

docs/utils/LityLexer.py

@@ -232,7 +232,7 @@ def type_names_mn(prefix, sizerangem, sizerangen):
             (r'push\b', Name.Function),
 
             # built-in functions and/or precompiles
-            (r'(addmod|ecrecover|keccak256|mulmod|ripemd160|sha256|sha3|eni|isValidator|schedule)\b',
+            (r'(addmod|ecrecover|keccak256|mulmod|ripemd160|sha256|sha3|eni|isValidator|freegas|rand|schedule)\b',
              Name.Function),
 
             # everything else is a var/function name

libevmasm/Instruction.cpp

@@ -66,6 +66,7 @@ const std::map<std::string, Instruction> dev::solidity::c_instructions =
 	{ "SFDIV", Instruction::SFDIV },
 	{ "ENI", Instruction::ENI },
 	{ "ISVALIDATOR", Instruction::ISVALIDATOR },
+	{ "RAND", Instruction::RAND },
 	{ "FREEGAS", Instruction::FREEGAS },
 	{ "ADDRESS", Instruction::ADDRESS },
 	{ "BALANCE", Instruction::BALANCE },
@@ -219,6 +220,7 @@ static const std::map<Instruction, InstructionInfo> c_instructionInfo =
 	{ Instruction::SFDIV,		{ "SFDIV",			0, 3, 1, false, Tier::Mid } },
 	{ Instruction::ENI,			{ "ENI",			0, 3, 1, true, Tier::Special } },
 	{ Instruction::ISVALIDATOR,			{ "ISVALIDATOR",			0, 1, 1, false, Tier::VeryLow } },
+	{ Instruction::RAND,			{ "RAND",			0, 0, 1, false, Tier::Low } },
 	{ Instruction::FREEGAS,			{ "FREEGAS",			0, 0, 0, false, Tier::VeryLow } },
 	{ Instruction::ADDRESS,		{ "ADDRESS",		0, 0, 1, false, Tier::Base } },
 	{ Instruction::BALANCE,		{ "BALANCE",		0, 1, 1, false, Tier::Balance } },

libevmasm/Instruction.h

@@ -202,6 +202,7 @@ enum class Instruction: uint8_t
 	ENI,
 	ISVALIDATOR = 0xf6,
 	FREEGAS = 0xf8,
+	RAND = 0xf9,
 	STATICCALL = 0xfa,	///< like CALL but disallow state modifications
 	CREATE2 = 0xfb,		///< create new account with associated code at address `sha3(sender + salt + sha3(init code)) % 2**160`
 

libsolidity/analysis/GlobalContext.cpp

@@ -53,6 +53,7 @@ m_magicVariables(vector<shared_ptr<MagicVariableDeclaration const>>{
 	make_shared<MagicVariableDeclaration>("msg", make_shared<MagicType>(MagicType::Kind::Message)),
 	make_shared<MagicVariableDeclaration>("mulmod", make_shared<FunctionType>(strings{"uint256", "uint256", "uint256"}, strings{"uint256"}, FunctionType::Kind::MulMod, FunctionType::SpecialModifier::Default, false, StateMutability::Pure)),
 	make_shared<MagicVariableDeclaration>("now", make_shared<IntegerType>(256)),
+	make_shared<MagicVariableDeclaration>("rand", make_shared<FunctionType>(strings(), strings{"uint256"}, FunctionType::Kind::Rand, FunctionType::SpecialModifier::Default, true, StateMutability::Pure)),
 	make_shared<MagicVariableDeclaration>("require", make_shared<FunctionType>(strings{"bool"}, strings{}, FunctionType::Kind::Require, FunctionType::SpecialModifier::Default, false, StateMutability::Pure)),
 	make_shared<MagicVariableDeclaration>("require", make_shared<FunctionType>(strings{"bool", "string memory"}, strings{}, FunctionType::Kind::Require, FunctionType::SpecialModifier::Default, false, StateMutability::Pure)),
 	make_shared<MagicVariableDeclaration>("revert", make_shared<FunctionType>(strings(), strings(), FunctionType::Kind::Revert, FunctionType::SpecialModifier::Default, false, StateMutability::Pure)),

libsolidity/ast/Types.cpp

@@ -2590,6 +2590,7 @@ string FunctionType::richIdentifier() const
 	case Kind::ABIEncodeWithSignature: id += "abiencodewithsignature"; break;
 	case Kind::ENI: id += "eni"; break;
 	case Kind::IsValidator: id += "isvalidator"; break;
+	case Kind::Rand: id += "rand"; break;
 	default: solAssert(false, "Unknown function location."); break;
 	}
 	switch (m_specialModifier)
@@ -2969,6 +2970,7 @@ bool FunctionType::isPure() const
 		m_kind == Kind::ABIEncodeWithSelector ||
 		m_kind == Kind::ABIEncodeWithSignature ||
 		m_kind == Kind::IsValidator ||
+		m_kind == Kind::Rand ||
 		m_kind == Kind::ENI;
 }
 

libsolidity/ast/Types.h

@@ -930,8 +930,9 @@ class FunctionType: public Type
 		ABIEncodeWithSelector,
 		ABIEncodeWithSignature,
 		GasLeft, ///< gasleft()
-		ENI,
-		IsValidator ///< isValidator()
+		ENI, ///< eni()
+		IsValidator, ///< isValidator()
+		Rand ///< rand()
 	};
 
 	virtual Category category() const override { return Category::Function; }

libsolidity/codegen/ExpressionCompiler.cpp

@@ -1076,6 +1076,9 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 		case FunctionType::Kind::GasLeft:
 			m_context << Instruction::GAS;
 			break;
+		case FunctionType::Kind::Rand:
+			m_context << Instruction::RAND;
+			break;
 		case FunctionType::Kind::IsValidator:
 			arguments.front()->accept(*this);
 			utils().convertType(*arguments.front()->annotation().type, *function.parameterTypes().front(), true);

libsolidity/interface/EVMVersion.h

@@ -79,6 +79,8 @@ class EVMVersion:
 	bool hasStaticCall() const { return *this >= byzantium(); }
 	bool hasENI() const {return *this == lity(); }
 	bool hasIsValidator() const {return *this == lity(); }
+	bool hasFreeGas() const {return *this == lity(); }
+	bool hasRand() const {return *this == lity(); }
 	bool hasBitwiseShifting() const { return *this >= constantinople(); }
 
 	/// Whether we have to retain the costs for the call opcode itself (false),