Side effects propagator.

This commit is contained in:
chriseth 2019-08-13 16:25:12 +02:00
parent c047803b80
commit a2a06d0318
5 changed files with 74 additions and 7 deletions

View File

@ -73,6 +73,16 @@ struct SideEffects
*this = *this + _other;
return *this;
}
bool operator==(SideEffects const& _other) const
{
return
movable == _other.movable &&
sideEffectFree == _other.sideEffectFree &&
sideEffectFreeIfNoMSize == _other.sideEffectFreeIfNoMSize &&
invalidatesStorage == _other.invalidatesStorage &&
invalidatesMemory == _other.invalidatesMemory;
}
};
}

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@ -29,18 +29,24 @@ using namespace std;
using namespace dev;
using namespace yul;
map<YulString, set<YulString>> CallGraphGenerator::callGraph(Block const& _ast)
{
CallGraphGenerator gen;
gen(_ast);
return std::move(gen.m_callGraph);
}
void CallGraphGenerator::operator()(FunctionalInstruction const& _functionalInstruction)
{
m_callGraph.insert(m_currentFunction, YulString{
dev::eth::instructionInfo(_functionalInstruction.instruction).name
});
string name = dev::eth::instructionInfo(_functionalInstruction.instruction).name;
std::transform(name.begin(), name.end(), name.begin(), [](unsigned char _c) { return tolower(_c); });
m_callGraph[m_currentFunction].insert(YulString{name});
ASTWalker::operator()(_functionalInstruction);
}
void CallGraphGenerator::operator()(FunctionCall const& _functionCall)
{
m_callGraph.insert(m_currentFunction, _functionCall.functionName.name);
m_callGraph[m_currentFunction].insert(_functionCall.functionName.name);
ASTWalker::operator()(_functionCall);
}
@ -48,7 +54,14 @@ void CallGraphGenerator::operator()(FunctionDefinition const& _functionDefinitio
{
YulString previousFunction = m_currentFunction;
m_currentFunction = _functionDefinition.name;
yulAssert(m_callGraph.count(m_currentFunction) == 0, "");
m_callGraph[m_currentFunction] = {};
ASTWalker::operator()(_functionDefinition);
m_currentFunction = previousFunction;
}
CallGraphGenerator::CallGraphGenerator()
{
m_callGraph[YulString{}] = {};
}

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@ -40,8 +40,7 @@ namespace yul
class CallGraphGenerator: public ASTWalker
{
public:
/// @returns the call graph of the visited AST.
InvertibleRelation<YulString> const& callGraph() const { return m_callGraph; }
static std::map<YulString, std::set<YulString>> callGraph(Block const& _ast);
using ASTWalker::operator();
void operator()(FunctionalInstruction const& _functionalInstruction) override;
@ -49,7 +48,9 @@ public:
void operator()(FunctionDefinition const& _functionDefinition) override;
private:
InvertibleRelation<YulString> m_callGraph;
CallGraphGenerator();
std::map<YulString, std::set<YulString>> m_callGraph;
/// The name of the function we are currently visiting during traversal.
YulString m_currentFunction;
};

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@ -28,6 +28,7 @@
#include <libevmasm/SemanticInformation.h>
#include <libdevcore/CommonData.h>
#include <libdevcore/Algorithms.h>
using namespace std;
using namespace dev;
@ -93,6 +94,33 @@ void MSizeFinder::operator()(FunctionCall const& _functionCall)
m_msizeFound = true;
}
map<YulString, SideEffects> SideEffectsPropagator::sideEffects(
Dialect const& _dialect,
map<YulString, std::set<YulString>> const& _directCallGraph
)
{
map<YulString, SideEffects> ret;
for (auto const& call: _directCallGraph)
{
YulString funName = call.first;
SideEffects sideEffects;
BreadthFirstSearch<YulString>{call.second, {funName}}.run(
[&](YulString _function, auto&& _addChild) {
if (sideEffects == SideEffects::worst())
return;
if (BuiltinFunction const* f = _dialect.builtin(_function))
sideEffects += f->sideEffects;
else
for (YulString callee: _directCallGraph.at(_function))
_addChild(callee);
}
);
ret[funName] = sideEffects;
}
return ret;
}
MovableChecker::MovableChecker(Dialect const& _dialect, Expression const& _expression):
MovableChecker(_dialect)
{

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@ -62,6 +62,21 @@ private:
SideEffects m_sideEffects;
};
/**
* This class can be used to determine the side-effects of user-defined functions.
*
* It is given a dialect and a mapping that represents the direct calls from user-defined
* functions to other user-defined functions and built-in functions.
*/
class SideEffectsPropagator
{
public:
static std::map<YulString, SideEffects> sideEffects(
Dialect const& _dialect,
std::map<YulString, std::set<YulString>> const& _directCallGraph
);
};
/**
* Class that can be used to find out if certain code contains the MSize instruction.
*