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Change translation of implicit throws (issue ethereum#1589).
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This adds a new invalid instruction that is used for encoding
implicit throws that are emitted by the compiler. This makes it
possible to distinguish such runtime errors from user-provided,
explicit throws.
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wuestholz authored and chriseth committed Jan 26, 2017
1 parent 102fd7e commit 9bcbd93
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Showing 10 changed files with 49 additions and 17 deletions.
2 changes: 2 additions & 0 deletions libevmasm/Instruction.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -154,6 +154,7 @@ const std::map<std::string, Instruction> dev::solidity::c_instructions =
{ "LOG2", Instruction::LOG2 },
{ "LOG3", Instruction::LOG3 },
{ "LOG4", Instruction::LOG4 },
{ "INVALID", Instruction::INVALID },
{ "CREATE", Instruction::CREATE },
{ "CALL", Instruction::CALL },
{ "CALLCODE", Instruction::CALLCODE },
Expand Down Expand Up @@ -288,6 +289,7 @@ static const std::map<Instruction, InstructionInfo> c_instructionInfo =
{ Instruction::LOG2, { "LOG2", 0, 4, 0, true, Tier::Special } },
{ Instruction::LOG3, { "LOG3", 0, 5, 0, true, Tier::Special } },
{ Instruction::LOG4, { "LOG4", 0, 6, 0, true, Tier::Special } },
{ Instruction::INVALID, { "INVALID", 0, 0, 0, true, Tier::Zero } },
{ Instruction::CREATE, { "CREATE", 0, 3, 1, true, Tier::Special } },
{ Instruction::CALL, { "CALL", 0, 7, 1, true, Tier::Special } },
{ Instruction::CALLCODE, { "CALLCODE", 0, 7, 1, true, Tier::Special } },
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2 changes: 2 additions & 0 deletions libevmasm/Instruction.h
Original file line number Diff line number Diff line change
Expand Up @@ -171,6 +171,8 @@ enum class Instruction: uint8_t
LOG3, ///< Makes a log entry; 3 topics.
LOG4, ///< Makes a log entry; 4 topics.

INVALID = 0xef, ///< invalid instruction for expressing runtime errors (e.g., division-by-zero)

CREATE = 0xf0, ///< create a new account with associated code
CALL, ///< message-call into an account
CALLCODE, ///< message-call with another account's code only
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2 changes: 1 addition & 1 deletion libsolidity/codegen/ArrayUtils.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -901,7 +901,7 @@ void ArrayUtils::accessIndex(ArrayType const& _arrayType, bool _doBoundsCheck) c
// check out-of-bounds access
m_context << Instruction::DUP2 << Instruction::LT << Instruction::ISZERO;
// out-of-bounds access throws exception
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
}
if (location == DataLocation::CallData && _arrayType.isDynamicallySized())
// remove length if present
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12 changes: 12 additions & 0 deletions libsolidity/codegen/CompilerContext.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -215,6 +215,18 @@ CompilerContext& CompilerContext::appendJump(eth::AssemblyItem::JumpType _jumpTy
return *this << item;
}

CompilerContext& CompilerContext::appendInvalid()
{
return *this << Instruction::INVALID;
}

CompilerContext& CompilerContext::appendConditionalInvalid()
{
eth::AssemblyItem falseTag = appendConditionalJump();
eth::AssemblyItem endTag = appendJumpToNew();
return *this << falseTag << Instruction::INVALID << endTag;
}

void CompilerContext::resetVisitedNodes(ASTNode const* _node)
{
stack<ASTNode const*> newStack;
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4 changes: 4 additions & 0 deletions libsolidity/codegen/CompilerContext.h
Original file line number Diff line number Diff line change
Expand Up @@ -127,6 +127,10 @@ class CompilerContext
eth::AssemblyItem appendJumpToNew() { return m_asm->appendJump().tag(); }
/// Appends a JUMP to a tag already on the stack
CompilerContext& appendJump(eth::AssemblyItem::JumpType _jumpType = eth::AssemblyItem::JumpType::Ordinary);
/// Appends an INVALID instruction
CompilerContext& appendInvalid();
/// Appends a conditional INVALID instruction
CompilerContext& appendConditionalInvalid();
/// Returns an "ErrorTag"
eth::AssemblyItem errorTag() { return m_asm->errorTag(); }
/// Appends a JUMP to a specific tag
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6 changes: 3 additions & 3 deletions libsolidity/codegen/CompilerUtils.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -468,7 +468,7 @@ void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetTyp
EnumType const& enumType = dynamic_cast<decltype(enumType)>(_typeOnStack);
solAssert(enumType.numberOfMembers() > 0, "empty enum should have caused a parser error.");
m_context << u256(enumType.numberOfMembers() - 1) << Instruction::DUP2 << Instruction::GT;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
enumOverflowCheckPending = false;
}
break;
Expand Down Expand Up @@ -497,7 +497,7 @@ void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetTyp
EnumType const& enumType = dynamic_cast<decltype(enumType)>(_targetType);
solAssert(enumType.numberOfMembers() > 0, "empty enum should have caused a parser error.");
m_context << u256(enumType.numberOfMembers() - 1) << Instruction::DUP2 << Instruction::GT;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
enumOverflowCheckPending = false;
}
else if (targetTypeCategory == Type::Category::FixedPoint)
Expand Down Expand Up @@ -807,7 +807,7 @@ void CompilerUtils::pushZeroValue(Type const& _type)
{
if (funType->location() == FunctionType::Location::Internal)
{
m_context << m_context.errorTag();
m_context.appendInvalid();
return;
}
}
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8 changes: 5 additions & 3 deletions libsolidity/codegen/ContractCompiler.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -106,7 +106,7 @@ void ContractCompiler::appendCallValueCheck()
{
// Throw if function is not payable but call contained ether.
m_context << Instruction::CALLVALUE;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
}

void ContractCompiler::appendInitAndConstructorCode(ContractDefinition const& _contract)
Expand Down Expand Up @@ -271,7 +271,7 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac
appendReturnValuePacker(FunctionType(*fallback).returnParameterTypes(), _contract.isLibrary());
}
else
m_context.appendJumpTo(m_context.errorTag());
m_context.appendInvalid();

for (auto const& it: interfaceFunctions)
{
Expand Down Expand Up @@ -918,7 +918,9 @@ eth::AssemblyPointer ContractCompiler::cloneRuntime()
a << Instruction::DELEGATECALL;
//Propagate error condition (if DELEGATECALL pushes 0 on stack).
a << Instruction::ISZERO;
a.appendJumpI(a.errorTag());
eth::AssemblyItem falseTag = a.appendJumpI();
eth::AssemblyItem endTag = a.appendJump().tag();
a << falseTag << Instruction::INVALID << endTag;
//@todo adjust for larger return values, make this dynamic.
a << u256(0x20) << u256(0) << Instruction::RETURN;
return make_shared<eth::Assembly>(a);
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12 changes: 6 additions & 6 deletions libsolidity/codegen/ExpressionCompiler.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -585,7 +585,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
m_context << Instruction::CREATE;
// Check if zero (out of stack or not enough balance).
m_context << Instruction::DUP1 << Instruction::ISZERO;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
if (function.valueSet())
m_context << swapInstruction(1) << Instruction::POP;
break;
Expand Down Expand Up @@ -1234,7 +1234,7 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
m_context << u256(fixedBytesType.numBytes());
m_context << Instruction::DUP2 << Instruction::LT << Instruction::ISZERO;
// out-of-bounds access throws exception
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();

m_context << Instruction::BYTE;
m_context << (u256(1) << (256 - 8)) << Instruction::MUL;
Expand Down Expand Up @@ -1416,7 +1416,7 @@ void ExpressionCompiler::appendArithmeticOperatorCode(Token::Value _operator, Ty
{
// Test for division by zero
m_context << Instruction::DUP2 << Instruction::ISZERO;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();

if (_operator == Token::Div)
m_context << (c_isSigned ? Instruction::SDIV : Instruction::DIV);
Expand Down Expand Up @@ -1477,7 +1477,7 @@ void ExpressionCompiler::appendShiftOperatorCode(Token::Value _operator, Type co
if (c_amountSigned)
{
m_context << u256(0) << Instruction::DUP3 << Instruction::SLT;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
}

switch (_operator)
Expand Down Expand Up @@ -1663,7 +1663,7 @@ void ExpressionCompiler::appendExternalFunctionCall(
if (funKind == FunctionKind::External || funKind == FunctionKind::CallCode || funKind == FunctionKind::DelegateCall)
{
m_context << Instruction::DUP1 << Instruction::EXTCODESIZE << Instruction::ISZERO;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
existenceChecked = true;
}

Expand Down Expand Up @@ -1699,7 +1699,7 @@ void ExpressionCompiler::appendExternalFunctionCall(
{
//Propagate error condition (if CALL pushes 0 on stack).
m_context << Instruction::ISZERO;
m_context.appendConditionalJumpTo(m_context.errorTag());
m_context.appendConditionalInvalid();
}

utils().popStackSlots(remainsSize);
Expand Down
4 changes: 2 additions & 2 deletions test/libsolidity/Assembly.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -116,8 +116,8 @@ BOOST_AUTO_TEST_CASE(location_test)
shared_ptr<string const> n = make_shared<string>("");
AssemblyItems items = compileContract(sourceCode);
vector<SourceLocation> locations =
vector<SourceLocation>(18, SourceLocation(2, 75, n)) +
vector<SourceLocation>(27, SourceLocation(20, 72, n)) +
vector<SourceLocation>(17, SourceLocation(2, 75, n)) +
vector<SourceLocation>(32, SourceLocation(20, 72, n)) +
vector<SourceLocation>{SourceLocation(42, 51, n), SourceLocation(65, 67, n)} +
vector<SourceLocation>(2, SourceLocation(58, 67, n)) +
vector<SourceLocation>(3, SourceLocation(20, 72, n));
Expand Down
14 changes: 12 additions & 2 deletions test/libsolidity/SolidityExpressionCompiler.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -337,13 +337,23 @@ BOOST_AUTO_TEST_CASE(arithmetics)
byte(Instruction::ADD),
byte(Instruction::DUP2),
byte(Instruction::ISZERO),
byte(Instruction::PUSH1), 0x0,
byte(Instruction::PUSH1), 0x1e,
byte(Instruction::JUMPI),
byte(Instruction::PUSH1), 0x20,
byte(Instruction::JUMP),
byte(Instruction::JUMPDEST),
byte(Instruction::INVALID),
byte(Instruction::JUMPDEST),
byte(Instruction::MOD),
byte(Instruction::DUP2),
byte(Instruction::ISZERO),
byte(Instruction::PUSH1), 0x0,
byte(Instruction::PUSH1), 0x2a,
byte(Instruction::JUMPI),
byte(Instruction::PUSH1), 0x2c,
byte(Instruction::JUMP),
byte(Instruction::JUMPDEST),
byte(Instruction::INVALID),
byte(Instruction::JUMPDEST),
byte(Instruction::DIV),
byte(Instruction::MUL)});
BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
Expand Down

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