solidity/libsolidity/analysis/ReferencesResolver.cpp

351 lines
13 KiB
C++

/*
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 2015
* Component that resolves type names to types and annotates the AST accordingly.
*/
#include <libsolidity/analysis/ReferencesResolver.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/analysis/NameAndTypeResolver.h>
#include <libsolidity/interface/Exceptions.h>
#include <libsolidity/analysis/ConstantEvaluator.h>
#include <libsolidity/inlineasm/AsmAnalysis.h>
#include <libsolidity/inlineasm/AsmAnalysisInfo.h>
#include <libsolidity/inlineasm/AsmData.h>
#include <libsolidity/interface/ErrorReporter.h>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace dev;
using namespace dev::solidity;
bool ReferencesResolver::resolve(ASTNode const& _root)
{
_root.accept(*this);
return !m_errorOccurred;
}
bool ReferencesResolver::visit(Identifier const& _identifier)
{
auto declarations = m_resolver.nameFromCurrentScope(_identifier.name());
if (declarations.empty())
fatalDeclarationError(_identifier.location(), "Undeclared identifier.");
else if (declarations.size() == 1)
_identifier.annotation().referencedDeclaration = declarations.front();
else
_identifier.annotation().overloadedDeclarations =
m_resolver.cleanedDeclarations(_identifier, declarations);
return false;
}
bool ReferencesResolver::visit(ElementaryTypeName const& _typeName)
{
_typeName.annotation().type = Type::fromElementaryTypeName(_typeName.typeName());
return true;
}
bool ReferencesResolver::visit(FunctionDefinition const& _functionDefinition)
{
m_returnParameters.push_back(_functionDefinition.returnParameterList().get());
return true;
}
void ReferencesResolver::endVisit(FunctionDefinition const&)
{
solAssert(!m_returnParameters.empty(), "");
m_returnParameters.pop_back();
}
bool ReferencesResolver::visit(ModifierDefinition const&)
{
m_returnParameters.push_back(nullptr);
return true;
}
void ReferencesResolver::endVisit(ModifierDefinition const&)
{
solAssert(!m_returnParameters.empty(), "");
m_returnParameters.pop_back();
}
void ReferencesResolver::endVisit(UserDefinedTypeName const& _typeName)
{
Declaration const* declaration = m_resolver.pathFromCurrentScope(_typeName.namePath());
if (!declaration)
fatalDeclarationError(_typeName.location(), "Identifier not found or not unique.");
_typeName.annotation().referencedDeclaration = declaration;
if (StructDefinition const* structDef = dynamic_cast<StructDefinition const*>(declaration))
_typeName.annotation().type = make_shared<StructType>(*structDef);
else if (EnumDefinition const* enumDef = dynamic_cast<EnumDefinition const*>(declaration))
_typeName.annotation().type = make_shared<EnumType>(*enumDef);
else if (ContractDefinition const* contract = dynamic_cast<ContractDefinition const*>(declaration))
_typeName.annotation().type = make_shared<ContractType>(*contract);
else
fatalTypeError(_typeName.location(), "Name has to refer to a struct, enum or contract.");
}
void ReferencesResolver::endVisit(FunctionTypeName const& _typeName)
{
switch (_typeName.visibility())
{
case VariableDeclaration::Visibility::Internal:
case VariableDeclaration::Visibility::External:
break;
default:
fatalTypeError(_typeName.location(), "Invalid visibility, can only be \"external\" or \"internal\".");
}
if (_typeName.isPayable() && _typeName.visibility() != VariableDeclaration::Visibility::External)
fatalTypeError(_typeName.location(), "Only external function types can be payable.");
if (_typeName.visibility() == VariableDeclaration::Visibility::External)
for (auto const& t: _typeName.parameterTypes() + _typeName.returnParameterTypes())
{
solAssert(t->annotation().type, "Type not set for parameter.");
if (!t->annotation().type->canBeUsedExternally(false))
fatalTypeError(t->location(), "Internal type cannot be used for external function type.");
}
_typeName.annotation().type = make_shared<FunctionType>(_typeName);
}
void ReferencesResolver::endVisit(Mapping const& _typeName)
{
TypePointer keyType = _typeName.keyType().annotation().type;
TypePointer valueType = _typeName.valueType().annotation().type;
// Convert key type to memory.
keyType = ReferenceType::copyForLocationIfReference(DataLocation::Memory, keyType);
// Convert value type to storage reference.
valueType = ReferenceType::copyForLocationIfReference(DataLocation::Storage, valueType);
_typeName.annotation().type = make_shared<MappingType>(keyType, valueType);
}
void ReferencesResolver::endVisit(ArrayTypeName const& _typeName)
{
TypePointer baseType = _typeName.baseType().annotation().type;
if (baseType->storageBytes() == 0)
fatalTypeError(_typeName.baseType().location(), "Illegal base type of storage size zero for array.");
if (Expression const* length = _typeName.length())
{
if (!length->annotation().type)
ConstantEvaluator e(*length);
auto const* lengthType = dynamic_cast<RationalNumberType const*>(length->annotation().type.get());
if (!lengthType || lengthType->isFractional())
fatalTypeError(length->location(), "Invalid array length, expected integer literal.");
else if (lengthType->isNegative())
fatalTypeError(length->location(), "Array with negative length specified.");
else
_typeName.annotation().type = make_shared<ArrayType>(DataLocation::Storage, baseType, lengthType->literalValue(nullptr));
}
else
_typeName.annotation().type = make_shared<ArrayType>(DataLocation::Storage, baseType);
}
bool ReferencesResolver::visit(InlineAssembly const& _inlineAssembly)
{
m_resolver.warnVariablesNamedLikeInstructions();
// Errors created in this stage are completely ignored because we do not yet know
// the type and size of external identifiers, which would result in false errors.
// The only purpose of this step is to fill the inline assembly annotation with
// external references.
ErrorList errors;
ErrorReporter errorsIgnored(errors);
julia::ExternalIdentifierAccess::Resolver resolver =
[&](assembly::Identifier const& _identifier, julia::IdentifierContext, bool _crossesFunctionBoundary) {
auto declarations = m_resolver.nameFromCurrentScope(_identifier.name);
bool isSlot = boost::algorithm::ends_with(_identifier.name, "_slot");
bool isOffset = boost::algorithm::ends_with(_identifier.name, "_offset");
if (isSlot || isOffset)
{
// special mode to access storage variables
if (!declarations.empty())
// the special identifier exists itself, we should not allow that.
return size_t(-1);
string realName = _identifier.name.substr(0, _identifier.name.size() - (
isSlot ?
string("_slot").size() :
string("_offset").size()
));
declarations = m_resolver.nameFromCurrentScope(realName);
}
if (declarations.size() != 1)
return size_t(-1);
if (auto var = dynamic_cast<VariableDeclaration const*>(declarations.front()))
if (var->isLocalVariable() && _crossesFunctionBoundary)
{
declarationError(_identifier.location, "Cannot access local Solidity variables from inside an inline assembly function.");
return size_t(-1);
}
_inlineAssembly.annotation().externalReferences[&_identifier].isSlot = isSlot;
_inlineAssembly.annotation().externalReferences[&_identifier].isOffset = isOffset;
_inlineAssembly.annotation().externalReferences[&_identifier].declaration = declarations.front();
return size_t(1);
};
// Will be re-generated later with correct information
assembly::AsmAnalysisInfo analysisInfo;
assembly::AsmAnalyzer(analysisInfo, errorsIgnored, false, resolver).analyze(_inlineAssembly.operations());
return false;
}
bool ReferencesResolver::visit(Return const& _return)
{
solAssert(!m_returnParameters.empty(), "");
_return.annotation().functionReturnParameters = m_returnParameters.back();
return true;
}
void ReferencesResolver::endVisit(VariableDeclaration const& _variable)
{
if (_variable.annotation().type)
return;
TypePointer type;
if (_variable.typeName())
{
type = _variable.typeName()->annotation().type;
using Location = VariableDeclaration::Location;
Location varLoc = _variable.referenceLocation();
DataLocation typeLoc = DataLocation::Memory;
// References are forced to calldata for external function parameters (not return)
// and memory for parameters (also return) of publicly visible functions.
// They default to memory for function parameters and storage for local variables.
// As an exception, "storage" is allowed for library functions.
if (auto ref = dynamic_cast<ReferenceType const*>(type.get()))
{
bool isPointer = true;
if (_variable.isExternalCallableParameter())
{
auto const& contract = dynamic_cast<ContractDefinition const&>(
*dynamic_cast<Declaration const&>(*_variable.scope()).scope()
);
if (contract.isLibrary())
{
if (varLoc == Location::Memory)
fatalTypeError(_variable.location(),
"Location has to be calldata or storage for external "
"library functions (remove the \"memory\" keyword)."
);
}
else
{
// force location of external function parameters (not return) to calldata
if (varLoc != Location::Default)
fatalTypeError(_variable.location(),
"Location has to be calldata for external functions "
"(remove the \"memory\" or \"storage\" keyword)."
);
}
if (varLoc == Location::Default)
typeLoc = DataLocation::CallData;
else
typeLoc = varLoc == Location::Memory ? DataLocation::Memory : DataLocation::Storage;
}
else if (_variable.isCallableParameter() && dynamic_cast<Declaration const&>(*_variable.scope()).isPublic())
{
auto const& contract = dynamic_cast<ContractDefinition const&>(
*dynamic_cast<Declaration const&>(*_variable.scope()).scope()
);
// force locations of public or external function (return) parameters to memory
if (varLoc == Location::Storage && !contract.isLibrary())
fatalTypeError(_variable.location(),
"Location has to be memory for publicly visible functions "
"(remove the \"storage\" keyword)."
);
if (varLoc == Location::Default || !contract.isLibrary())
typeLoc = DataLocation::Memory;
else
typeLoc = varLoc == Location::Memory ? DataLocation::Memory : DataLocation::Storage;
}
else
{
if (_variable.isConstant())
{
if (varLoc != Location::Default && varLoc != Location::Memory)
fatalTypeError(
_variable.location(),
"Storage location has to be \"memory\" (or unspecified) for constants."
);
typeLoc = DataLocation::Memory;
}
else if (varLoc == Location::Default)
{
if (_variable.isCallableParameter())
typeLoc = DataLocation::Memory;
else
{
typeLoc = DataLocation::Storage;
if (_variable.isLocalVariable())
m_errorReporter.warning(
_variable.location(),
"Variable is declared as a storage pointer. "
"Use an explicit \"storage\" keyword to silence this warning."
);
}
}
else
typeLoc = varLoc == Location::Memory ? DataLocation::Memory : DataLocation::Storage;
isPointer = !_variable.isStateVariable();
}
type = ref->copyForLocation(typeLoc, isPointer);
}
else if (varLoc != Location::Default && !ref)
fatalTypeError(_variable.location(), "Storage location can only be given for array or struct types.");
if (!type)
fatalTypeError(_variable.location(), "Invalid type name.");
}
else if (!_variable.canHaveAutoType())
fatalTypeError(_variable.location(), "Explicit type needed.");
// otherwise we have a "var"-declaration whose type is resolved by the first assignment
_variable.annotation().type = type;
}
void ReferencesResolver::typeError(SourceLocation const& _location, string const& _description)
{
m_errorOccurred = true;
m_errorReporter.typeError(_location, _description);
}
void ReferencesResolver::fatalTypeError(SourceLocation const& _location, string const& _description)
{
m_errorOccurred = true;
m_errorReporter.fatalTypeError(_location, _description);
}
void ReferencesResolver::declarationError(SourceLocation const& _location, string const& _description)
{
m_errorOccurred = true;
m_errorReporter.declarationError(_location, _description);
}
void ReferencesResolver::fatalDeclarationError(SourceLocation const& _location, string const& _description)
{
m_errorOccurred = true;
m_errorReporter.fatalDeclarationError(_location, _description);
}