solidity/libsolidity/analysis/ControlFlowBuilder.cpp

371 lines
9.7 KiB
C++
Raw Normal View History

2018-05-04 13:58:10 +00:00
/*
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/>.
*/
#include <libsolidity/analysis/ControlFlowBuilder.h>
using namespace dev;
using namespace solidity;
using namespace std;
ControlFlowBuilder::ControlFlowBuilder(CFG::NodeContainer& _nodeContainer, FunctionFlow const& _functionFlow):
m_nodeContainer(_nodeContainer), m_currentFunctionFlow(_functionFlow), m_currentNode(_functionFlow.entry)
{
}
unique_ptr<FunctionFlow> ControlFlowBuilder::createFunctionFlow(
CFG::NodeContainer& _nodeContainer,
FunctionDefinition const& _function
)
{
auto functionFlow = unique_ptr<FunctionFlow>(new FunctionFlow());
functionFlow->entry = _nodeContainer.newNode();
functionFlow->exit = _nodeContainer.newNode();
functionFlow->revert = _nodeContainer.newNode();
ControlFlowBuilder builder(_nodeContainer, *functionFlow);
builder.appendControlFlow(_function);
connect(builder.m_currentNode, functionFlow->exit);
return functionFlow;
}
unique_ptr<ModifierFlow> ControlFlowBuilder::createModifierFlow(
CFG::NodeContainer& _nodeContainer,
ModifierDefinition const& _modifier
)
{
auto modifierFlow = unique_ptr<ModifierFlow>(new ModifierFlow());
modifierFlow->entry = _nodeContainer.newNode();
modifierFlow->exit = _nodeContainer.newNode();
modifierFlow->revert = _nodeContainer.newNode();
modifierFlow->placeholderEntry = _nodeContainer.newNode();
modifierFlow->placeholderExit = _nodeContainer.newNode();
ControlFlowBuilder builder(_nodeContainer, *modifierFlow);
builder.appendControlFlow(_modifier);
connect(builder.m_currentNode, modifierFlow->exit);
return modifierFlow;
}
bool ControlFlowBuilder::visit(BinaryOperation const& _operation)
{
solAssert(!!m_currentNode, "");
switch(_operation.getOperator())
{
case Token::Or:
case Token::And:
{
appendControlFlow(_operation.leftExpression());
auto nodes = splitFlow<2>();
nodes[0] = createFlow(nodes[0], _operation.rightExpression());
mergeFlow(nodes, nodes[1]);
return false;
}
default:
break;
}
return ASTConstVisitor::visit(_operation);
}
bool ControlFlowBuilder::visit(Conditional const& _conditional)
{
solAssert(!!m_currentNode, "");
_conditional.condition().accept(*this);
auto nodes = splitFlow<2>();
nodes[0] = createFlow(nodes[0], _conditional.trueExpression());
nodes[1] = createFlow(nodes[1], _conditional.falseExpression());
mergeFlow(nodes);
return false;
}
bool ControlFlowBuilder::visit(IfStatement const& _ifStatement)
{
solAssert(!!m_currentNode, "");
_ifStatement.condition().accept(*this);
auto nodes = splitFlow<2>();
nodes[0] = createFlow(nodes[0], _ifStatement.trueStatement());
if (_ifStatement.falseStatement())
{
nodes[1] = createFlow(nodes[1], *_ifStatement.falseStatement());
mergeFlow(nodes);
}
else
mergeFlow(nodes, nodes[1]);
return false;
}
bool ControlFlowBuilder::visit(ForStatement const& _forStatement)
{
solAssert(!!m_currentNode, "");
if (_forStatement.initializationExpression())
_forStatement.initializationExpression()->accept(*this);
auto condition = createLabelHere();
if (_forStatement.condition())
appendControlFlow(*_forStatement.condition());
auto loopExpression = newLabel();
auto nodes = splitFlow<2>();
auto afterFor = nodes[1];
m_currentNode = nodes[0];
{
BreakContinueScope scope(*this, afterFor, loopExpression);
appendControlFlow(_forStatement.body());
}
placeAndConnectLabel(loopExpression);
if (auto expression = _forStatement.loopExpression())
appendControlFlow(*expression);
connect(m_currentNode, condition);
m_currentNode = afterFor;
return false;
}
bool ControlFlowBuilder::visit(WhileStatement const& _whileStatement)
{
solAssert(!!m_currentNode, "");
if (_whileStatement.isDoWhile())
{
auto afterWhile = newLabel();
auto whileBody = createLabelHere();
{
// Note that "continue" in this case currently indeed jumps to whileBody
// and not to the condition. This is inconsistent with JavaScript and C and
// therefore a bug. This will be fixed in the future (planned for 0.5.0)
// and the Control Flow Graph will have to be adjusted accordingly.
BreakContinueScope scope(*this, afterWhile, whileBody);
appendControlFlow(_whileStatement.body());
}
appendControlFlow(_whileStatement.condition());
connect(m_currentNode, whileBody);
placeAndConnectLabel(afterWhile);
}
else
{
auto whileCondition = createLabelHere();
appendControlFlow(_whileStatement.condition());
auto nodes = splitFlow<2>();
auto whileBody = nodes[0];
auto afterWhile = nodes[1];
m_currentNode = whileBody;
{
BreakContinueScope scope(*this, afterWhile, whileCondition);
appendControlFlow(_whileStatement.body());
}
connect(m_currentNode, whileCondition);
m_currentNode = afterWhile;
}
return false;
}
bool ControlFlowBuilder::visit(Break const&)
{
solAssert(!!m_currentNode, "");
solAssert(!!m_breakJump, "");
connect(m_currentNode, m_breakJump);
m_currentNode = newLabel();
return false;
}
bool ControlFlowBuilder::visit(Continue const&)
{
solAssert(!!m_currentNode, "");
solAssert(!!m_continueJump, "");
connect(m_currentNode, m_continueJump);
m_currentNode = newLabel();
return false;
}
bool ControlFlowBuilder::visit(Throw const&)
{
solAssert(!!m_currentNode, "");
solAssert(!!m_currentFunctionFlow.revert, "");
connect(m_currentNode, m_currentFunctionFlow.revert);
m_currentNode = newLabel();
return false;
}
bool ControlFlowBuilder::visit(Block const&)
{
solAssert(!!m_currentNode, "");
createLabelHere();
return true;
}
void ControlFlowBuilder::endVisit(Block const&)
{
solAssert(!!m_currentNode, "");
createLabelHere();
}
bool ControlFlowBuilder::visit(Return const& _return)
{
solAssert(!!m_currentNode, "");
solAssert(!!m_currentFunctionFlow.exit, "");
solAssert(!m_currentNode->block.returnStatement, "");
m_currentNode->block.returnStatement = &_return;
connect(m_currentNode, m_currentFunctionFlow.exit);
m_currentNode = newLabel();
return true;
}
bool ControlFlowBuilder::visit(PlaceholderStatement const&)
{
solAssert(!!m_currentNode, "");
auto modifierFlow = dynamic_cast<ModifierFlow const*>(&m_currentFunctionFlow);
solAssert(!!modifierFlow, "");
connect(m_currentNode, modifierFlow->placeholderEntry);
m_currentNode = newLabel();
connect(modifierFlow->placeholderExit, m_currentNode);
return false;
}
bool ControlFlowBuilder::visitNode(ASTNode const& node)
{
solAssert(!!m_currentNode, "");
if (auto const* expression = dynamic_cast<Expression const*>(&node))
m_currentNode->block.expressions.emplace_back(expression);
else if (auto const* variableDeclaration = dynamic_cast<VariableDeclaration const*>(&node))
m_currentNode->block.variableDeclarations.emplace_back(variableDeclaration);
else if (auto const* assembly = dynamic_cast<InlineAssembly const*>(&node))
m_currentNode->block.inlineAssemblyStatements.emplace_back(assembly);
return true;
}
bool ControlFlowBuilder::visit(FunctionCall const& _functionCall)
{
solAssert(!!m_currentNode, "");
solAssert(!!_functionCall.expression().annotation().type, "");
if (auto functionType = dynamic_pointer_cast<FunctionType const>(_functionCall.expression().annotation().type))
switch (functionType->kind())
{
case FunctionType::Kind::Revert:
solAssert(!!m_currentFunctionFlow.revert, "");
_functionCall.expression().accept(*this);
ASTNode::listAccept(_functionCall.arguments(), *this);
connect(m_currentNode, m_currentFunctionFlow.revert);
m_currentNode = newLabel();
return false;
case FunctionType::Kind::Require:
case FunctionType::Kind::Assert:
{
solAssert(!!m_currentFunctionFlow.revert, "");
_functionCall.expression().accept(*this);
ASTNode::listAccept(_functionCall.arguments(), *this);
connect(m_currentNode, m_currentFunctionFlow.revert);
auto nextNode = newLabel();
connect(m_currentNode, nextNode);
m_currentNode = nextNode;
return false;
}
default:
break;
}
return ASTConstVisitor::visit(_functionCall);
}
void ControlFlowBuilder::appendControlFlow(ASTNode const& _node)
{
_node.accept(*this);
}
CFGNode* ControlFlowBuilder::createFlow(CFGNode* _entry, ASTNode const& _node)
{
auto oldCurrentNode = m_currentNode;
m_currentNode = _entry;
appendControlFlow(_node);
auto endNode = m_currentNode;
m_currentNode = oldCurrentNode;
return endNode;
}
void ControlFlowBuilder::connect(CFGNode* _from, CFGNode* _to)
{
solAssert(_from, "");
solAssert(_to, "");
_from->exits.push_back(_to);
_to->entries.push_back(_from);
}
CFGNode* ControlFlowBuilder::newLabel()
{
return m_nodeContainer.newNode();
}
CFGNode* ControlFlowBuilder::createLabelHere()
{
auto label = m_nodeContainer.newNode();
connect(m_currentNode, label);
m_currentNode = label;
return label;
}
void ControlFlowBuilder::placeAndConnectLabel(CFGNode* _node)
{
connect(m_currentNode, _node);
m_currentNode = _node;
}
ControlFlowBuilder::BreakContinueScope::BreakContinueScope(
ControlFlowBuilder& _parser,
CFGNode* _breakJump,
CFGNode* _continueJump
): m_parser(_parser), m_origBreakJump(_parser.m_breakJump), m_origContinueJump(_parser.m_continueJump)
{
m_parser.m_breakJump = _breakJump;
m_parser.m_continueJump = _continueJump;
}
ControlFlowBuilder::BreakContinueScope::~BreakContinueScope()
{
m_parser.m_breakJump = m_origBreakJump;
m_parser.m_continueJump = m_origContinueJump;
}