solidity/libsolidity/ast/AST.cpp

/*
	This file is part of solidity.

	solidity is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	solidity is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
/**
 * @author Christian <c@ethdev.com>
 * @date 2014
 * Solidity abstract syntax tree.
 */

#include <libsolidity/ast/AST.h>

#include <libsolidity/ast/ASTVisitor.h>
#include <libsolidity/ast/AST_accept.h>
#include <libsolidity/ast/TypeProvider.h>
#include <libsolutil/Keccak256.h>

#include <boost/algorithm/string.hpp>
#include <algorithm>
#include <functional>

using namespace std;
using namespace solidity;
using namespace solidity::frontend;

class IDDispenser
{
public:
	static size_t next() { return ++instance(); }
	static void reset() { instance() = 0; }
private:
	static size_t& instance()
	{
		static IDDispenser dispenser;
		return dispenser.id;
	}
	size_t id = 0;
};

ASTNode::ASTNode(SourceLocation const& _location):
	m_id(IDDispenser::next()),
	m_location(_location)
{
}

void ASTNode::resetID()
{
	IDDispenser::reset();
}

ASTAnnotation& ASTNode::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<ASTAnnotation>();
	return *m_annotation;
}

SourceUnitAnnotation& SourceUnit::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<SourceUnitAnnotation>();
	return dynamic_cast<SourceUnitAnnotation&>(*m_annotation);
}

set<SourceUnit const*> SourceUnit::referencedSourceUnits(bool _recurse, set<SourceUnit const*> _skipList) const
{
	set<SourceUnit const*> sourceUnits;
	for (ImportDirective const* importDirective: filteredNodes<ImportDirective>(nodes()))
	{
		auto const& sourceUnit = importDirective->annotation().sourceUnit;
		if (!_skipList.count(sourceUnit))
		{
			_skipList.insert(sourceUnit);
			sourceUnits.insert(sourceUnit);
			if (_recurse)
				sourceUnits += sourceUnit->referencedSourceUnits(true, _skipList);
		}
	}
	return sourceUnits;
}

ImportAnnotation& ImportDirective::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<ImportAnnotation>();
	return dynamic_cast<ImportAnnotation&>(*m_annotation);
}

TypePointer ImportDirective::type() const
{
	solAssert(!!annotation().sourceUnit, "");
	return TypeProvider::module(*annotation().sourceUnit);
}

vector<VariableDeclaration const*> ContractDefinition::stateVariablesIncludingInherited() const
{
	vector<VariableDeclaration const*> stateVars;
	for (auto const& contract: annotation().linearizedBaseContracts)
		for (auto var: contract->stateVariables())
			if (*contract == *this || var->isVisibleInDerivedContracts())
				stateVars.push_back(var);
	return stateVars;
}

map<util::FixedHash<4>, FunctionTypePointer> ContractDefinition::interfaceFunctions() const
{
	auto exportedFunctionList = interfaceFunctionList();

	map<util::FixedHash<4>, FunctionTypePointer> exportedFunctions;
	for (auto const& it: exportedFunctionList)
		exportedFunctions.insert(it);

	solAssert(
		exportedFunctionList.size() == exportedFunctions.size(),
		"Hash collision at Function Definition Hash calculation"
	);

	return exportedFunctions;
}

FunctionDefinition const* ContractDefinition::constructor() const
{
	for (FunctionDefinition const* f: definedFunctions())
		if (f->isConstructor())
			return f;
	return nullptr;
}

bool ContractDefinition::constructorIsPublic() const
{
	FunctionDefinition const* f = constructor();
	return !f || f->isPublic();
}

bool ContractDefinition::canBeDeployed() const
{
	return constructorIsPublic() && !abstract() && !isInterface();
}

FunctionDefinition const* ContractDefinition::fallbackFunction() const
{
	for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
		for (FunctionDefinition const* f: contract->definedFunctions())
			if (f->isFallback())
				return f;
	return nullptr;
}

FunctionDefinition const* ContractDefinition::receiveFunction() const
{
	for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
		for (FunctionDefinition const* f: contract->definedFunctions())
			if (f->isReceive())
				return f;
	return nullptr;
}

vector<EventDefinition const*> const& ContractDefinition::interfaceEvents() const
{
	if (!m_interfaceEvents)
	{
		set<string> eventsSeen;
		m_interfaceEvents = make_unique<vector<EventDefinition const*>>();
		for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
			for (EventDefinition const* e: contract->events())
			{
				/// NOTE: this requires the "internal" version of an Event,
				///       though here internal strictly refers to visibility,
				///       and not to function encoding (jump vs. call)
				auto const& function = e->functionType(true);
				solAssert(function, "");
				string eventSignature = function->externalSignature();
				if (eventsSeen.count(eventSignature) == 0)
				{
					eventsSeen.insert(eventSignature);
					m_interfaceEvents->push_back(e);
				}
			}
	}
	return *m_interfaceEvents;
}

vector<pair<util::FixedHash<4>, FunctionTypePointer>> const& ContractDefinition::interfaceFunctionList() const
{
	if (!m_interfaceFunctionList)
	{
		set<string> signaturesSeen;
		m_interfaceFunctionList = make_unique<vector<pair<util::FixedHash<4>, FunctionTypePointer>>>();
		for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
		{
			vector<FunctionTypePointer> functions;
			for (FunctionDefinition const* f: contract->definedFunctions())
				if (f->isPartOfExternalInterface())
					functions.push_back(TypeProvider::function(*f, false));
			for (VariableDeclaration const* v: contract->stateVariables())
				if (v->isPartOfExternalInterface())
					functions.push_back(TypeProvider::function(*v));
			for (FunctionTypePointer const& fun: functions)
			{
				if (!fun->interfaceFunctionType())
					// Fails hopefully because we already registered the error
					continue;
				string functionSignature = fun->externalSignature();
				if (signaturesSeen.count(functionSignature) == 0)
				{
					signaturesSeen.insert(functionSignature);
					util::FixedHash<4> hash(util::keccak256(functionSignature));
					m_interfaceFunctionList->emplace_back(hash, fun);
				}
			}
		}
	}
	return *m_interfaceFunctionList;
}

vector<Declaration const*> const& ContractDefinition::inheritableMembers() const
{
	if (!m_inheritableMembers)
	{
		m_inheritableMembers = make_unique<vector<Declaration const*>>();
		auto addInheritableMember = [&](Declaration const* _decl)
		{
			solAssert(_decl, "addInheritableMember got a nullpointer.");
			if (_decl->isVisibleInDerivedContracts())
				m_inheritableMembers->push_back(_decl);
		};

		for (FunctionDefinition const* f: definedFunctions())
			addInheritableMember(f);

		for (VariableDeclaration const* v: stateVariables())
			addInheritableMember(v);

		for (StructDefinition const* s: definedStructs())
			addInheritableMember(s);

		for (EnumDefinition const* e: definedEnums())
			addInheritableMember(e);

		for (EventDefinition const* e: events())
			addInheritableMember(e);
	}
	return *m_inheritableMembers;
}

TypePointer ContractDefinition::type() const
{
	return TypeProvider::typeType(TypeProvider::contract(*this));
}

ContractDefinitionAnnotation& ContractDefinition::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<ContractDefinitionAnnotation>();
	return dynamic_cast<ContractDefinitionAnnotation&>(*m_annotation);
}

TypeNameAnnotation& TypeName::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<TypeNameAnnotation>();
	return dynamic_cast<TypeNameAnnotation&>(*m_annotation);
}

TypePointer StructDefinition::type() const
{
	return TypeProvider::typeType(TypeProvider::structType(*this, DataLocation::Storage));
}

TypeDeclarationAnnotation& StructDefinition::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<TypeDeclarationAnnotation>();
	return dynamic_cast<TypeDeclarationAnnotation&>(*m_annotation);
}

TypePointer EnumValue::type() const
{
	auto parentDef = dynamic_cast<EnumDefinition const*>(scope());
	solAssert(parentDef, "Enclosing Scope of EnumValue was not set");
	return TypeProvider::enumType(*parentDef);
}

TypePointer EnumDefinition::type() const
{
	return TypeProvider::typeType(TypeProvider::enumType(*this));
}

TypeDeclarationAnnotation& EnumDefinition::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<TypeDeclarationAnnotation>();
	return dynamic_cast<TypeDeclarationAnnotation&>(*m_annotation);
}

ContractKind FunctionDefinition::inContractKind() const
{
	auto contractDef = dynamic_cast<ContractDefinition const*>(scope());
	solAssert(contractDef, "Enclosing Scope of FunctionDefinition was not set.");
	return contractDef->contractKind();
}

CallableDeclarationAnnotation& CallableDeclaration::annotation() const
{
	solAssert(
		m_annotation,
		"CallableDeclarationAnnotation is an abstract base, need to call annotation on the concrete class first."
	);
	return dynamic_cast<CallableDeclarationAnnotation&>(*m_annotation);
}


FunctionTypePointer FunctionDefinition::functionType(bool _internal) const
{
	if (_internal)
	{
		switch (visibility())
		{
		case Visibility::Default:
			solAssert(false, "visibility() should not return Default");
		case Visibility::Private:
		case Visibility::Internal:
		case Visibility::Public:
			return TypeProvider::function(*this, _internal);
		case Visibility::External:
			return {};
		}
	}
	else
	{
		switch (visibility())
		{
		case Visibility::Default:
			solAssert(false, "visibility() should not return Default");
		case Visibility::Private:
		case Visibility::Internal:
			return {};
		case Visibility::Public:
		case Visibility::External:
			return TypeProvider::function(*this, _internal);
		}
	}

	// To make the compiler happy
	return {};
}

TypePointer FunctionDefinition::type() const
{
	solAssert(visibility() != Visibility::External, "");
	return TypeProvider::function(*this);
}

string FunctionDefinition::externalSignature() const
{
	return TypeProvider::function(*this)->externalSignature();
}

string FunctionDefinition::externalIdentifierHex() const
{
	return TypeProvider::function(*this)->externalIdentifierHex();
}

FunctionDefinitionAnnotation& FunctionDefinition::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<FunctionDefinitionAnnotation>();
	return dynamic_cast<FunctionDefinitionAnnotation&>(*m_annotation);
}

TypePointer ModifierDefinition::type() const
{
	return TypeProvider::modifier(*this);
}

ModifierDefinitionAnnotation& ModifierDefinition::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<ModifierDefinitionAnnotation>();
	return dynamic_cast<ModifierDefinitionAnnotation&>(*m_annotation);
}

TypePointer EventDefinition::type() const
{
	return TypeProvider::function(*this);
}

FunctionTypePointer EventDefinition::functionType(bool _internal) const
{
	if (_internal)
		return TypeProvider::function(*this);
	else
		return nullptr;
}

EventDefinitionAnnotation& EventDefinition::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<EventDefinitionAnnotation>();
	return dynamic_cast<EventDefinitionAnnotation&>(*m_annotation);
}

UserDefinedTypeNameAnnotation& UserDefinedTypeName::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<UserDefinedTypeNameAnnotation>();
	return dynamic_cast<UserDefinedTypeNameAnnotation&>(*m_annotation);
}

SourceUnit const& Scopable::sourceUnit() const
{
	ASTNode const* s = scope();
	solAssert(s, "");
	// will not always be a declaration
	while (dynamic_cast<Scopable const*>(s) && dynamic_cast<Scopable const*>(s)->scope())
		s = dynamic_cast<Scopable const*>(s)->scope();
	return dynamic_cast<SourceUnit const&>(*s);
}

CallableDeclaration const* Scopable::functionOrModifierDefinition() const
{
	ASTNode const* s = scope();
	solAssert(s, "");
	while (dynamic_cast<Scopable const*>(s))
	{
		if (auto funDef = dynamic_cast<FunctionDefinition const*>(s))
			return funDef;
		if (auto modDef = dynamic_cast<ModifierDefinition const*>(s))
			return modDef;
		s = dynamic_cast<Scopable const*>(s)->scope();
	}
	return nullptr;
}

string Scopable::sourceUnitName() const
{
	return sourceUnit().annotation().path;
}

DeclarationAnnotation& Declaration::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<DeclarationAnnotation>();
	return dynamic_cast<DeclarationAnnotation&>(*m_annotation);
}

bool VariableDeclaration::isLValue() const
{
	// Constant declared variables are Read-Only
	if (m_isConstant)
		return false;
	// External function arguments of reference type are Read-Only
	if (isExternalCallableParameter() && dynamic_cast<ReferenceType const*>(type()))
		return false;
	return true;
}

bool VariableDeclaration::isLocalVariable() const
{
	auto s = scope();
	return
		dynamic_cast<FunctionTypeName const*>(s) ||
		dynamic_cast<CallableDeclaration const*>(s) ||
		dynamic_cast<Block const*>(s) ||
		dynamic_cast<TryCatchClause const*>(s) ||
		dynamic_cast<ForStatement const*>(s);
}

bool VariableDeclaration::isCallableOrCatchParameter() const
{
	if (isReturnParameter() || isTryCatchParameter())
		return true;

	vector<ASTPointer<VariableDeclaration>> const* parameters = nullptr;

	if (auto const* funTypeName = dynamic_cast<FunctionTypeName const*>(scope()))
		parameters = &funTypeName->parameterTypes();
	else if (auto const* callable = dynamic_cast<CallableDeclaration const*>(scope()))
		parameters = &callable->parameters();

	if (parameters)
		for (auto const& variable: *parameters)
			if (variable.get() == this)
				return true;
	return false;
}

bool VariableDeclaration::isLocalOrReturn() const
{
	return isReturnParameter() || (isLocalVariable() && !isCallableOrCatchParameter());
}

bool VariableDeclaration::isReturnParameter() const
{
	vector<ASTPointer<VariableDeclaration>> const* returnParameters = nullptr;

	if (auto const* funTypeName = dynamic_cast<FunctionTypeName const*>(scope()))
		returnParameters = &funTypeName->returnParameterTypes();
	else if (auto const* callable = dynamic_cast<CallableDeclaration const*>(scope()))
		if (callable->returnParameterList())
			returnParameters = &callable->returnParameterList()->parameters();

	if (returnParameters)
		for (auto const& variable: *returnParameters)
			if (variable.get() == this)
				return true;
	return false;
}

bool VariableDeclaration::isTryCatchParameter() const
{
	return dynamic_cast<TryCatchClause const*>(scope());
}

bool VariableDeclaration::isExternalCallableParameter() const
{
	if (!isCallableOrCatchParameter())
		return false;

	if (auto const* callable = dynamic_cast<CallableDeclaration const*>(scope()))
		if (callable->visibility() == Visibility::External)
			return !isReturnParameter();

	return false;
}

bool VariableDeclaration::isInternalCallableParameter() const
{
	if (!isCallableOrCatchParameter())
		return false;

	if (auto const* funTypeName = dynamic_cast<FunctionTypeName const*>(scope()))
		return funTypeName->visibility() == Visibility::Internal;
	else if (auto const* callable = dynamic_cast<CallableDeclaration const*>(scope()))
		return callable->visibility() <= Visibility::Internal;
	return false;
}

bool VariableDeclaration::isLibraryFunctionParameter() const
{
	if (!isCallableOrCatchParameter())
		return false;
	if (auto const* funDef = dynamic_cast<FunctionDefinition const*>(scope()))
		return dynamic_cast<ContractDefinition const&>(*funDef->scope()).isLibrary();
	else
		return false;
}

bool VariableDeclaration::isEventParameter() const
{
	return dynamic_cast<EventDefinition const*>(scope()) != nullptr;
}

bool VariableDeclaration::hasReferenceOrMappingType() const
{
	solAssert(typeName(), "");
	solAssert(typeName()->annotation().type, "Can only be called after reference resolution");
	Type const* type = typeName()->annotation().type;
	return type->category() == Type::Category::Mapping || dynamic_cast<ReferenceType const*>(type);
}

set<VariableDeclaration::Location> VariableDeclaration::allowedDataLocations() const
{
	using Location = VariableDeclaration::Location;

	if (!hasReferenceOrMappingType() || isStateVariable() || isEventParameter())
		return set<Location>{ Location::Unspecified };
	else if (isStateVariable() && isConstant())
		return set<Location>{ Location::Memory };
	else if (isExternalCallableParameter())
	{
		set<Location> locations{ Location::CallData };
		if (isLibraryFunctionParameter())
			locations.insert(Location::Storage);
		return locations;
	}
	else if (isCallableOrCatchParameter())
	{
		set<Location> locations{ Location::Memory };
		if (isInternalCallableParameter() || isLibraryFunctionParameter() || isTryCatchParameter())
			locations.insert(Location::Storage);
		return locations;
	}
	else if (isLocalVariable())
	{
		solAssert(typeName(), "");
		solAssert(typeName()->annotation().type, "Can only be called after reference resolution");
		if (typeName()->annotation().type->category() == Type::Category::Mapping)
			return set<Location>{ Location::Storage };
		else
			//  TODO: add Location::Calldata once implemented for local variables.
			return set<Location>{ Location::Memory, Location::Storage };
	}
	else
		// Struct members etc.
		return set<Location>{ Location::Unspecified };
}

string VariableDeclaration::externalIdentifierHex() const
{
	solAssert(isStateVariable() && isPublic(), "Can only be called for public state variables");
	return TypeProvider::function(*this)->externalIdentifierHex();
}

TypePointer VariableDeclaration::type() const
{
	return annotation().type;
}

FunctionTypePointer VariableDeclaration::functionType(bool _internal) const
{
	if (_internal)
		return nullptr;
	switch (visibility())
	{
	case Visibility::Default:
		solAssert(false, "visibility() should not return Default");
	case Visibility::Private:
	case Visibility::Internal:
		return nullptr;
	case Visibility::Public:
	case Visibility::External:
		return TypeProvider::function(*this);
	}

	// To make the compiler happy
	return nullptr;
}

VariableDeclarationAnnotation& VariableDeclaration::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<VariableDeclarationAnnotation>();
	return dynamic_cast<VariableDeclarationAnnotation&>(*m_annotation);
}

StatementAnnotation& Statement::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<StatementAnnotation>();
	return dynamic_cast<StatementAnnotation&>(*m_annotation);
}

InlineAssemblyAnnotation& InlineAssembly::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<InlineAssemblyAnnotation>();
	return dynamic_cast<InlineAssemblyAnnotation&>(*m_annotation);
}

BlockAnnotation& Block::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<BlockAnnotation>();
	return dynamic_cast<BlockAnnotation&>(*m_annotation);
}

TryCatchClauseAnnotation& TryCatchClause::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<TryCatchClauseAnnotation>();
	return dynamic_cast<TryCatchClauseAnnotation&>(*m_annotation);
}

ForStatementAnnotation& ForStatement::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<ForStatementAnnotation>();
	return dynamic_cast<ForStatementAnnotation&>(*m_annotation);
}

ReturnAnnotation& Return::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<ReturnAnnotation>();
	return dynamic_cast<ReturnAnnotation&>(*m_annotation);
}

ExpressionAnnotation& Expression::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<ExpressionAnnotation>();
	return dynamic_cast<ExpressionAnnotation&>(*m_annotation);
}

MemberAccessAnnotation& MemberAccess::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<MemberAccessAnnotation>();
	return dynamic_cast<MemberAccessAnnotation&>(*m_annotation);
}

BinaryOperationAnnotation& BinaryOperation::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<BinaryOperationAnnotation>();
	return dynamic_cast<BinaryOperationAnnotation&>(*m_annotation);
}

FunctionCallAnnotation& FunctionCall::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<FunctionCallAnnotation>();
	return dynamic_cast<FunctionCallAnnotation&>(*m_annotation);
}

IdentifierAnnotation& Identifier::annotation() const
{
	if (!m_annotation)
		m_annotation = make_unique<IdentifierAnnotation>();
	return dynamic_cast<IdentifierAnnotation&>(*m_annotation);
}

ASTString Literal::valueWithoutUnderscores() const
{
	return boost::erase_all_copy(value(), "_");
}

bool Literal::isHexNumber() const
{
	if (token() != Token::Number)
		return false;
	return boost::starts_with(value(), "0x");
}

bool Literal::looksLikeAddress() const
{
	if (subDenomination() != SubDenomination::None)
		return false;

	if (!isHexNumber())
		return false;

	return abs(int(valueWithoutUnderscores().length()) - 42) <= 1;
}

bool Literal::passesAddressChecksum() const
{
	solAssert(isHexNumber(), "Expected hex number");
	return util::passesAddressChecksum(valueWithoutUnderscores(), true);
}

string Literal::getChecksummedAddress() const
{
	solAssert(isHexNumber(), "Expected hex number");
	/// Pad literal to be a proper hex address.
	string address = valueWithoutUnderscores().substr(2);
	if (address.length() > 40)
		return string();
	address.insert(address.begin(), 40 - address.size(), '0');
	return util::getChecksummedAddress(address);
}