solidity/libsolidity/analysis/FunctionCallGraph.cpp

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/*
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
#include <libsolidity/analysis/FunctionCallGraph.h>
#include <libsolutil/StringUtils.h>
#include <range/v3/range/conversion.hpp>
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#include <range/v3/view/reverse.hpp>
#include <range/v3/view/transform.hpp>
using namespace std;
using namespace ranges;
using namespace solidity::frontend;
using namespace solidity::util;
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CallGraph FunctionCallGraphBuilder::buildCreationGraph(ContractDefinition const& _contract)
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{
FunctionCallGraphBuilder builder(_contract);
solAssert(builder.m_currentNode == CallGraph::Node(CallGraph::SpecialNode::Entry), "");
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// Create graph for constructor, state vars, etc
for (ContractDefinition const* base: _contract.annotation().linearizedBaseContracts | views::reverse)
{
// The constructor and functions called in state variable initial assignments should have
// an edge from Entry
builder.m_currentNode = CallGraph::SpecialNode::Entry;
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for (auto const* stateVar: base->stateVariables())
if (!stateVar->isConstant())
stateVar->accept(builder);
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if (base->constructor())
{
builder.functionReferenced(*base->constructor());
// Constructors and functions called in state variable initializers have an edge either from
// the previous class in linearized order or from Entry if there's no class before.
builder.m_currentNode = base->constructor();
}
// Functions called from the inheritance specifier should have an edge from the constructor
// for consistency with functions called from constructor modifiers.
for (auto const& inheritanceSpecifier: base->baseContracts())
inheritanceSpecifier->accept(builder);
}
builder.m_currentNode = CallGraph::SpecialNode::Entry;
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builder.processQueue();
return move(builder.m_graph);
}
CallGraph FunctionCallGraphBuilder::buildDeployedGraph(
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ContractDefinition const& _contract,
CallGraph const& _creationGraph
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)
{
FunctionCallGraphBuilder builder(_contract);
solAssert(builder.m_currentNode == CallGraph::Node(CallGraph::SpecialNode::Entry), "");
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auto getSecondElement = [](auto const& _tuple){ return get<1>(_tuple); };
// Create graph for all publicly reachable functions
for (FunctionTypePointer functionType: _contract.interfaceFunctionList() | views::transform(getSecondElement))
{
auto const* function = dynamic_cast<FunctionDefinition const*>(&functionType->declaration());
auto const* variable = dynamic_cast<VariableDeclaration const*>(&functionType->declaration());
if (function)
builder.functionReferenced(*function);
else
// If it's not a function, it must be a getter of a public variable; we ignore those
solAssert(variable, "");
}
if (_contract.fallbackFunction())
builder.functionReferenced(*_contract.fallbackFunction());
if (_contract.receiveFunction())
builder.functionReferenced(*_contract.receiveFunction());
// All functions present in internal dispatch at creation time could potentially be pointers
// assigned to state variables and as such may be reachable after deployment as well.
builder.m_currentNode = CallGraph::SpecialNode::InternalDispatch;
for (CallGraph::Node const& dispatchTarget: valueOrDefault(_creationGraph.edges, CallGraph::SpecialNode::InternalDispatch, {}))
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{
solAssert(!holds_alternative<CallGraph::SpecialNode>(dispatchTarget), "");
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solAssert(get<CallableDeclaration const*>(dispatchTarget) != nullptr, "");
// Visit the callable to add not only it but also everything it calls too
builder.functionReferenced(*get<CallableDeclaration const*>(dispatchTarget), false);
}
builder.m_currentNode = CallGraph::SpecialNode::Entry;
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builder.processQueue();
return move(builder.m_graph);
}
bool FunctionCallGraphBuilder::visit(FunctionCall const& _functionCall)
{
if (*_functionCall.annotation().kind != FunctionCallKind::FunctionCall)
return true;
auto const* functionType = dynamic_cast<FunctionType const*>(_functionCall.expression().annotation().type);
solAssert(functionType, "");
if (functionType->kind() == FunctionType::Kind::Internal && !_functionCall.expression().annotation().calledDirectly)
// If it's not a direct call, we don't really know which function will be called (it may even
// change at runtime). All we can do is to add an edge to the dispatch which in turn has
// edges to all functions could possibly be called.
add(m_currentNode, CallGraph::SpecialNode::InternalDispatch);
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return true;
}
bool FunctionCallGraphBuilder::visit(EmitStatement const& _emitStatement)
{
auto const* functionType = dynamic_cast<FunctionType const*>(_emitStatement.eventCall().expression().annotation().type);
solAssert(functionType, "");
m_graph.emittedEvents.insert(&dynamic_cast<EventDefinition const&>(functionType->declaration()));
return true;
}
bool FunctionCallGraphBuilder::visit(Identifier const& _identifier)
{
if (auto const* variable = dynamic_cast<VariableDeclaration const*>(_identifier.annotation().referencedDeclaration))
{
if (variable->isConstant())
{
solAssert(variable->isStateVariable() || variable->isFileLevelVariable(), "");
variable->accept(*this);
}
}
else if (auto const* callable = dynamic_cast<CallableDeclaration const*>(_identifier.annotation().referencedDeclaration))
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{
solAssert(*_identifier.annotation().requiredLookup == VirtualLookup::Virtual, "");
auto funType = dynamic_cast<FunctionType const*>(_identifier.annotation().type);
// For events kind() == Event, so we have an extra check here
if (funType && funType->kind() == FunctionType::Kind::Internal)
functionReferenced(callable->resolveVirtual(m_contract), _identifier.annotation().calledDirectly);
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}
return true;
}
bool FunctionCallGraphBuilder::visit(MemberAccess const& _memberAccess)
{
auto functionType = dynamic_cast<FunctionType const*>(_memberAccess.annotation().type);
auto functionDef = dynamic_cast<FunctionDefinition const*>(_memberAccess.annotation().referencedDeclaration);
if (!functionType || !functionDef || functionType->kind() != FunctionType::Kind::Internal)
return true;
// Super functions
if (*_memberAccess.annotation().requiredLookup == VirtualLookup::Super)
{
if (auto const* typeType = dynamic_cast<TypeType const*>(_memberAccess.expression().annotation().type))
if (auto const contractType = dynamic_cast<ContractType const*>(typeType->actualType()))
{
solAssert(contractType->isSuper(), "");
functionDef = &functionDef->resolveVirtual(
m_contract,
contractType->contractDefinition().superContract(m_contract)
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);
}
}
else
solAssert(*_memberAccess.annotation().requiredLookup == VirtualLookup::Static, "");
functionReferenced(*functionDef, _memberAccess.annotation().calledDirectly);
return true;
}
bool FunctionCallGraphBuilder::visit(ModifierInvocation const& _modifierInvocation)
{
if (auto const* modifier = dynamic_cast<ModifierDefinition const*>(_modifierInvocation.name().annotation().referencedDeclaration))
{
VirtualLookup const& requiredLookup = *_modifierInvocation.name().annotation().requiredLookup;
if (requiredLookup == VirtualLookup::Virtual)
functionReferenced(modifier->resolveVirtual(m_contract));
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else
{
solAssert(requiredLookup == VirtualLookup::Static, "");
functionReferenced(*modifier);
}
}
return true;
}
bool FunctionCallGraphBuilder::visit(NewExpression const& _newExpression)
{
if (ContractType const* contractType = dynamic_cast<ContractType const*>(_newExpression.typeName().annotation().type))
m_graph.createdContracts.emplace(&contractType->contractDefinition());
return true;
}
void FunctionCallGraphBuilder::enqueueCallable(CallableDeclaration const& _callable)
{
if (!m_graph.edges.count(&_callable))
{
m_visitQueue.push_back(&_callable);
// Insert the callable to the graph (with no edges coming out of it) to mark it as visited.
m_graph.edges.insert({CallGraph::Node(&_callable), {}});
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}
}
void FunctionCallGraphBuilder::processQueue()
{
solAssert(m_currentNode == CallGraph::Node(CallGraph::SpecialNode::Entry), "Visit queue is already being processed.");
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while (!m_visitQueue.empty())
{
m_currentNode = m_visitQueue.front();
solAssert(holds_alternative<CallableDeclaration const*>(m_currentNode), "");
m_visitQueue.pop_front();
get<CallableDeclaration const*>(m_currentNode)->accept(*this);
}
m_currentNode = CallGraph::SpecialNode::Entry;
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}
void FunctionCallGraphBuilder::add(CallGraph::Node _caller, CallGraph::Node _callee)
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{
m_graph.edges[_caller].insert(_callee);
}
void FunctionCallGraphBuilder::functionReferenced(CallableDeclaration const& _callable, bool _calledDirectly)
{
if (_calledDirectly)
{
solAssert(
holds_alternative<CallGraph::SpecialNode>(m_currentNode) || m_graph.edges.count(m_currentNode) > 0,
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"Adding an edge from a node that has not been visited yet."
);
add(m_currentNode, &_callable);
}
else
add(CallGraph::SpecialNode::InternalDispatch, &_callable);
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enqueueCallable(_callable);
}
ostream& solidity::frontend::operator<<(ostream& _out, CallGraph::Node const& _node)
{
if (holds_alternative<CallGraph::SpecialNode>(_node))
switch (get<CallGraph::SpecialNode>(_node))
{
case CallGraph::SpecialNode::InternalDispatch:
_out << "InternalDispatch";
break;
case CallGraph::SpecialNode::Entry:
_out << "Entry";
break;
default:
solAssert(false, "Invalid SpecialNode type");
}
else
{
solAssert(holds_alternative<CallableDeclaration const*>(_node), "");
auto const* callableDeclaration = get<CallableDeclaration const*>(_node);
solAssert(callableDeclaration, "");
auto const* function = dynamic_cast<FunctionDefinition const *>(callableDeclaration);
auto const* event = dynamic_cast<EventDefinition const *>(callableDeclaration);
auto const* modifier = dynamic_cast<ModifierDefinition const *>(callableDeclaration);
auto typeToString = [](auto const& _var) -> string { return _var->type()->toString(true); };
vector<string> parameters = callableDeclaration->parameters() | views::transform(typeToString) | to<vector<string>>();
string scopeName;
if (!function || !function->isFree())
{
solAssert(callableDeclaration->annotation().scope, "");
auto const* parentContract = dynamic_cast<ContractDefinition const*>(callableDeclaration->annotation().scope);
solAssert(parentContract, "");
scopeName = parentContract->name();
}
if (function && function->isFree())
_out << "function " << function->name() << "(" << joinHumanReadable(parameters, ",") << ")";
else if (function && function->isConstructor())
_out << "constructor of " << scopeName;
else if (function && function->isFallback())
_out << "fallback of " << scopeName;
else if (function && function->isReceive())
_out << "receive of " << scopeName;
else if (function)
_out << "function " << scopeName << "." << function->name() << "(" << joinHumanReadable(parameters, ",") << ")";
else if (event)
_out << "event " << scopeName << "." << event->name() << "(" << joinHumanReadable(parameters, ",") << ")";
else if (modifier)
_out << "modifier " << scopeName << "." << modifier->name();
else
solAssert(false, "Unexpected AST node type in function call graph");
}
return _out;
}