From 500ab821044759594eb3db08876b2925b9b3709b Mon Sep 17 00:00:00 2001 From: Wei-Ning Huang Date: Thu, 18 Oct 2018 11:38:05 +0800 Subject: Add opcode RAND support DEXON has a built-in on chain random oracle that allow one to retrieve a random variable. Add `rand` solidity variable is introduced to load the random variable onto the stack. --- libevmasm/Instruction.cpp | 2 ++ libevmasm/Instruction.h | 1 + libevmasm/SemanticInformation.cpp | 1 + libsolidity/analysis/GlobalContext.cpp | 1 + libsolidity/analysis/ViewPureChecker.cpp | 2 +- libsolidity/codegen/ExpressionCompiler.cpp | 8 +++++++- 6 files changed, 13 insertions(+), 2 deletions(-) diff --git a/libevmasm/Instruction.cpp b/libevmasm/Instruction.cpp index cf98c938..2bd00821 100644 --- a/libevmasm/Instruction.cpp +++ b/libevmasm/Instruction.cpp @@ -58,6 +58,7 @@ const std::map dev::solidity::c_instructions = { "MULMOD", Instruction::MULMOD }, { "SIGNEXTEND", Instruction::SIGNEXTEND }, { "KECCAK256", Instruction::KECCAK256 }, + { "RAND", Instruction::RAND }, { "ADDRESS", Instruction::ADDRESS }, { "BALANCE", Instruction::BALANCE }, { "ORIGIN", Instruction::ORIGIN }, @@ -202,6 +203,7 @@ static const std::map c_instructionInfo = { Instruction::MULMOD, { "MULMOD", 0, 3, 1, false, Tier::Mid } }, { Instruction::SIGNEXTEND, { "SIGNEXTEND", 0, 2, 1, false, Tier::Low } }, { Instruction::KECCAK256, { "KECCAK256", 0, 2, 1, true, Tier::Special } }, + { Instruction::RAND, { "RAND", 0, 0, 1, false, Tier::High } }, { Instruction::ADDRESS, { "ADDRESS", 0, 0, 1, false, Tier::Base } }, { Instruction::BALANCE, { "BALANCE", 0, 1, 1, false, Tier::Balance } }, { Instruction::ORIGIN, { "ORIGIN", 0, 0, 1, false, Tier::Base } }, diff --git a/libevmasm/Instruction.h b/libevmasm/Instruction.h index 539a83b0..1540cbbe 100644 --- a/libevmasm/Instruction.h +++ b/libevmasm/Instruction.h @@ -66,6 +66,7 @@ enum class Instruction: uint8_t SAR, ///< bitwise SAR operation KECCAK256 = 0x20, ///< compute KECCAK-256 hash + RAND = 0x2f, ///< load a random value ADDRESS = 0x30, ///< get address of currently executing account BALANCE, ///< get balance of the given account diff --git a/libevmasm/SemanticInformation.cpp b/libevmasm/SemanticInformation.cpp index 2a24a27e..b068f6dc 100644 --- a/libevmasm/SemanticInformation.cpp +++ b/libevmasm/SemanticInformation.cpp @@ -239,6 +239,7 @@ bool SemanticInformation::invalidInPureFunctions(Instruction _instruction) case Instruction::BLOCKHASH: case Instruction::COINBASE: case Instruction::TIMESTAMP: + case Instruction::RAND: case Instruction::NUMBER: case Instruction::DIFFICULTY: case Instruction::GASLIMIT: diff --git a/libsolidity/analysis/GlobalContext.cpp b/libsolidity/analysis/GlobalContext.cpp index 2276d783..48489b6b 100644 --- a/libsolidity/analysis/GlobalContext.cpp +++ b/libsolidity/analysis/GlobalContext.cpp @@ -52,6 +52,7 @@ m_magicVariables(vector>{ make_shared("msg", make_shared(MagicType::Kind::Message)), make_shared("mulmod", make_shared(strings{"uint256", "uint256", "uint256"}, strings{"uint256"}, FunctionType::Kind::MulMod, false, StateMutability::Pure)), make_shared("now", make_shared(256)), + make_shared("rand", make_shared(256)), make_shared("require", make_shared(strings{"bool"}, strings{}, FunctionType::Kind::Require, false, StateMutability::Pure)), make_shared("require", make_shared(strings{"bool", "string memory"}, strings{}, FunctionType::Kind::Require, false, StateMutability::Pure)), make_shared("revert", make_shared(strings(), strings(), FunctionType::Kind::Revert, false, StateMutability::Pure)), diff --git a/libsolidity/analysis/ViewPureChecker.cpp b/libsolidity/analysis/ViewPureChecker.cpp index 7df7ac17..0ffe6a6a 100644 --- a/libsolidity/analysis/ViewPureChecker.cpp +++ b/libsolidity/analysis/ViewPureChecker.cpp @@ -201,7 +201,7 @@ void ViewPureChecker::endVisit(Identifier const& _identifier) mutability = StateMutability::View; break; case Type::Category::Integer: - solAssert(_identifier.name() == "now", ""); + solAssert(_identifier.name() == "now" || _identifier.name() == "rand", ""); mutability = StateMutability::View; break; default: diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp index e6bb163d..46a335bb 100644 --- a/libsolidity/codegen/ExpressionCompiler.cpp +++ b/libsolidity/codegen/ExpressionCompiler.cpp @@ -1314,6 +1314,8 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess) m_context << Instruction::COINBASE; else if (member == "timestamp") m_context << Instruction::TIMESTAMP; + else if (member == "rand") + m_context << Instruction::RAND; else if (member == "difficulty") m_context << Instruction::DIFFICULTY; else if (member == "number") @@ -1558,7 +1560,11 @@ void ExpressionCompiler::endVisit(Identifier const& _identifier) break; case Type::Category::Integer: // "now" - m_context << Instruction::TIMESTAMP; + if (_identifier.name() == "now") { + m_context << Instruction::TIMESTAMP; + } else if (_identifier.name() == "rand") { + m_context << Instruction::RAND; + } break; default: break; -- cgit