solidity/libsolidity/analysis/ReferencesResolver.cpp
hrkrshnn 1a6f0fe52f Disallow declarations to have names "this", "super" and "_".
There will be a declaration error 3726 if these names are used in the contract. Note that there is
an existing warning about shadowing a built-in for "this" and "super".
2020-11-25 11:14:13 +01:00

391 lines
11 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/>.
*/
// SPDX-License-Identifier: GPL-3.0
/**
* @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/analysis/NameAndTypeResolver.h>
#include <libsolidity/ast/AST.h>
#include <libyul/AsmAnalysis.h>
#include <libyul/AsmAnalysisInfo.h>
#include <libyul/AsmData.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <liblangutil/ErrorReporter.h>
#include <liblangutil/Exceptions.h>
#include <libsolutil/StringUtils.h>
#include <libsolutil/CommonData.h>
#include <boost/algorithm/string.hpp>
#include <boost/algorithm/string/split.hpp>
using namespace std;
using namespace solidity;
using namespace solidity::langutil;
using namespace solidity::frontend;
bool ReferencesResolver::resolve(ASTNode const& _root)
{
auto errorWatcher = m_errorReporter.errorWatcher();
_root.accept(*this);
return errorWatcher.ok();
}
bool ReferencesResolver::visit(Block const& _block)
{
if (!m_resolveInsideCode)
return false;
m_resolver.setScope(&_block);
return true;
}
void ReferencesResolver::endVisit(Block const& _block)
{
if (!m_resolveInsideCode)
return;
m_resolver.setScope(_block.scope());
}
bool ReferencesResolver::visit(TryCatchClause const& _tryCatchClause)
{
if (!m_resolveInsideCode)
return false;
m_resolver.setScope(&_tryCatchClause);
return true;
}
void ReferencesResolver::endVisit(TryCatchClause const& _tryCatchClause)
{
if (!m_resolveInsideCode)
return;
m_resolver.setScope(_tryCatchClause.scope());
}
bool ReferencesResolver::visit(ForStatement const& _for)
{
if (!m_resolveInsideCode)
return false;
m_resolver.setScope(&_for);
return true;
}
void ReferencesResolver::endVisit(ForStatement const& _for)
{
if (!m_resolveInsideCode)
return;
m_resolver.setScope(_for.scope());
}
void ReferencesResolver::endVisit(VariableDeclarationStatement const& _varDeclStatement)
{
if (!m_resolveInsideCode)
return;
for (auto const& var: _varDeclStatement.declarations())
if (var)
m_resolver.activateVariable(var->name());
}
bool ReferencesResolver::visit(VariableDeclaration const& _varDecl)
{
if (_varDecl.documentation())
resolveInheritDoc(*_varDecl.documentation(), _varDecl.annotation());
return true;
}
bool ReferencesResolver::visit(Identifier const& _identifier)
{
auto declarations = m_resolver.nameFromCurrentScope(_identifier.name());
if (declarations.empty())
{
string suggestions = m_resolver.similarNameSuggestions(_identifier.name());
string errorMessage = "Undeclared identifier.";
if (!suggestions.empty())
{
if ("\"" + _identifier.name() + "\"" == suggestions)
errorMessage += " " + std::move(suggestions) + " is not (or not yet) visible at this point.";
else
errorMessage += " Did you mean " + std::move(suggestions) + "?";
}
m_errorReporter.declarationError(7576_error, _identifier.location(), errorMessage);
}
else if (declarations.size() == 1)
_identifier.annotation().referencedDeclaration = declarations.front();
else
_identifier.annotation().candidateDeclarations = declarations;
return false;
}
bool ReferencesResolver::visit(FunctionDefinition const& _functionDefinition)
{
m_returnParameters.push_back(_functionDefinition.returnParameterList().get());
if (_functionDefinition.documentation())
resolveInheritDoc(*_functionDefinition.documentation(), _functionDefinition.annotation());
return true;
}
void ReferencesResolver::endVisit(FunctionDefinition const&)
{
solAssert(!m_returnParameters.empty(), "");
m_returnParameters.pop_back();
}
bool ReferencesResolver::visit(ModifierDefinition const& _modifierDefinition)
{
m_returnParameters.push_back(nullptr);
if (_modifierDefinition.documentation())
resolveInheritDoc(*_modifierDefinition.documentation(), _modifierDefinition.annotation());
return true;
}
void ReferencesResolver::endVisit(ModifierDefinition const&)
{
solAssert(!m_returnParameters.empty(), "");
m_returnParameters.pop_back();
}
void ReferencesResolver::endVisit(IdentifierPath const& _path)
{
Declaration const* declaration = m_resolver.pathFromCurrentScope(_path.path());
if (!declaration)
{
m_errorReporter.fatalDeclarationError(7920_error, _path.location(), "Identifier not found or not unique.");
return;
}
_path.annotation().referencedDeclaration = declaration;
}
bool ReferencesResolver::visit(InlineAssembly const& _inlineAssembly)
{
m_resolver.warnVariablesNamedLikeInstructions();
m_yulAnnotation = &_inlineAssembly.annotation();
(*this)(_inlineAssembly.operations());
m_yulAnnotation = nullptr;
return false;
}
bool ReferencesResolver::visit(Return const& _return)
{
solAssert(!m_returnParameters.empty(), "");
_return.annotation().functionReturnParameters = m_returnParameters.back();
return true;
}
void ReferencesResolver::operator()(yul::FunctionDefinition const& _function)
{
validateYulIdentifierName(_function.name, _function.location);
for (yul::TypedName const& varName: _function.parameters + _function.returnVariables)
validateYulIdentifierName(varName.name, varName.location);
bool wasInsideFunction = m_yulInsideFunction;
m_yulInsideFunction = true;
this->operator()(_function.body);
m_yulInsideFunction = wasInsideFunction;
}
void ReferencesResolver::operator()(yul::Identifier const& _identifier)
{
static set<string> suffixes{"slot", "offset", "length"};
string suffix;
for (string const& s: suffixes)
if (boost::algorithm::ends_with(_identifier.name.str(), "." + s))
suffix = s;
// Could also use `pathFromCurrentScope`, split by '.'
auto declarations = m_resolver.nameFromCurrentScope(_identifier.name.str());
if (!suffix.empty())
{
// special mode to access storage variables
if (!declarations.empty())
// the special identifier exists itself, we should not allow that.
return;
string realName = _identifier.name.str().substr(0, _identifier.name.str().size() - suffix.size() - 1);
solAssert(!realName.empty(), "Empty name.");
declarations = m_resolver.nameFromCurrentScope(realName);
if (!declarations.empty())
// To support proper path resolution, we have to use pathFromCurrentScope.
solAssert(!util::contains(realName, '.'), "");
}
if (declarations.size() > 1)
{
m_errorReporter.declarationError(
4718_error,
_identifier.location,
"Multiple matching identifiers. Resolving overloaded identifiers is not supported."
);
return;
}
else if (declarations.size() == 0)
{
if (
boost::algorithm::ends_with(_identifier.name.str(), "_slot") ||
boost::algorithm::ends_with(_identifier.name.str(), "_offset")
)
m_errorReporter.declarationError(
9467_error,
_identifier.location,
"Identifier not found. Use \".slot\" and \".offset\" to access storage variables."
);
return;
}
if (auto var = dynamic_cast<VariableDeclaration const*>(declarations.front()))
if (var->isLocalVariable() && m_yulInsideFunction)
{
m_errorReporter.declarationError(
6578_error,
_identifier.location,
"Cannot access local Solidity variables from inside an inline assembly function."
);
return;
}
m_yulAnnotation->externalReferences[&_identifier].suffix = move(suffix);
m_yulAnnotation->externalReferences[&_identifier].declaration = declarations.front();
}
void ReferencesResolver::operator()(yul::VariableDeclaration const& _varDecl)
{
for (auto const& identifier: _varDecl.variables)
{
validateYulIdentifierName(identifier.name, identifier.location);
if (
auto declarations = m_resolver.nameFromCurrentScope(identifier.name.str());
!declarations.empty()
)
{
SecondarySourceLocation ssl;
for (auto const* decl: declarations)
ssl.append("The shadowed declaration is here:", decl->location());
if (!ssl.infos.empty())
m_errorReporter.declarationError(
3859_error,
identifier.location,
ssl,
"This declaration shadows a declaration outside the inline assembly block."
);
}
}
if (_varDecl.value)
visit(*_varDecl.value);
}
void ReferencesResolver::resolveInheritDoc(StructuredDocumentation const& _documentation, StructurallyDocumentedAnnotation& _annotation)
{
switch (_annotation.docTags.count("inheritdoc"))
{
case 0:
break;
case 1:
{
string const& name = _annotation.docTags.find("inheritdoc")->second.content;
if (name.empty())
{
m_errorReporter.docstringParsingError(
1933_error,
_documentation.location(),
"Expected contract name following documentation tag @inheritdoc."
);
return;
}
vector<string> path;
boost::split(path, name, boost::is_any_of("."));
if (any_of(path.begin(), path.end(), [](auto& _str) { return _str.empty(); }))
{
m_errorReporter.docstringParsingError(
5967_error,
_documentation.location(),
"Documentation tag @inheritdoc reference \"" +
name +
"\" is malformed."
);
return;
}
Declaration const* result = m_resolver.pathFromCurrentScope(path);
if (result == nullptr)
{
m_errorReporter.docstringParsingError(
9397_error,
_documentation.location(),
"Documentation tag @inheritdoc references inexistent contract \"" +
name +
"\"."
);
return;
}
else
{
_annotation.inheritdocReference = dynamic_cast<ContractDefinition const*>(result);
if (!_annotation.inheritdocReference)
m_errorReporter.docstringParsingError(
1430_error,
_documentation.location(),
"Documentation tag @inheritdoc reference \"" +
name +
"\" is not a contract."
);
}
break;
}
default:
m_errorReporter.docstringParsingError(
5142_error,
_documentation.location(),
"Documentation tag @inheritdoc can only be given once."
);
break;
}
}
void ReferencesResolver::validateYulIdentifierName(yul::YulString _name, SourceLocation const& _location)
{
if (util::contains(_name.str(), '.'))
m_errorReporter.declarationError(
3927_error,
_location,
"User-defined identifiers in inline assembly cannot contain '.'."
);
if (set<string>{"this", "super", "_"}.count(_name.str()))
m_errorReporter.declarationError(
4113_error,
_location,
"The identifier name \"" + _name.str() + "\" is reserved."
);
}