//
// Method: getDSNodeHandle()
//
// Description:
// This method looks up the DSNodeHandle for a given LLVM value. The context
// of the value is the specified function, although if it is a global value,
// the DSNodeHandle may exist within the global DSGraph.
//
// Return value:
// A DSNodeHandle for the value is returned. This DSNodeHandle could either
// be in the function's DSGraph or from the GlobalsGraph. Note that the
// DSNodeHandle may represent a NULL DSNode.
//
DSNodeHandle
CompleteChecks::getDSNodeHandle (const Value * V, const Function * F) {
//
// Get access to the points-to results.
//
EQTDDataStructures & dsaPass = getAnalysis<EQTDDataStructures>();
//
// Ensure that the function has a DSGraph
//
assert (dsaPass.hasDSGraph(*F) && "No DSGraph for function!\n");
//
// Lookup the DSNode for the value in the function's DSGraph.
//
DSGraph * TDG = dsaPass.getDSGraph(*F);
DSNodeHandle DSH = TDG->getNodeForValue(V);
//
// If the value wasn't found in the function's DSGraph, then maybe we can
// find the value in the globals graph.
//
if ((DSH.isNull()) && (isa<GlobalValue>(V))) {
//
// Try looking up this DSNode value in the globals graph. Note that
// globals are put into equivalence classes; we may need to first find the
// equivalence class to which our global belongs, find the global that
// represents all globals in that equivalence class, and then look up the
// DSNode Handle for *that* global.
//
DSGraph * GlobalsGraph = TDG->getGlobalsGraph ();
DSH = GlobalsGraph->getNodeForValue(V);
if (DSH.isNull()) {
//
// DSA does not currently handle global aliases.
//
if (!isa<GlobalAlias>(V)) {
//
// We have to dig into the globalEC of the DSGraph to find the DSNode.
//
const GlobalValue * GV = dyn_cast<GlobalValue>(V);
const GlobalValue * Leader;
Leader = GlobalsGraph->getGlobalECs().getLeaderValue(GV);
DSH = GlobalsGraph->getNodeForValue(Leader);
}
}
}
return DSH;
}
bool
SteensgaardDataStructures::runOnModuleInternal(Module &M) {
assert(ResultGraph == 0 && "Result graph already allocated!");
// Get a copy for the globals graph.
DSGraph * GG = DS->getGlobalsGraph();
GlobalsGraph = new DSGraph(GG, GG->getGlobalECs(), 0, 0);
// Create a new, empty, graph...
ResultGraph = new DSGraph(GG->getGlobalECs(), getDataLayout(), GlobalsGraph);
// Loop over the rest of the module, merging graphs for non-external functions
// into this graph.
//
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
if (!I->isDeclaration()) {
ResultGraph->spliceFrom(DS->getDSGraph(I));
}
}
ResultGraph->removeTriviallyDeadNodes();
// FIXME: Must recalculate and use the Incomplete markers!!
// Now that we have all of the graphs inlined, we can go about eliminating
// call nodes...
//
// Start with a copy of the original call sites.
std::list<DSCallSite> & Calls = ResultGraph->getFunctionCalls();
for (std::list<DSCallSite>::iterator CI = Calls.begin(), E = Calls.end();
CI != E;) {
DSCallSite &CurCall = *CI++;
// Loop over the called functions, eliminating as many as possible...
std::vector<const Function*> CallTargets;
if (CurCall.isDirectCall())
CallTargets.push_back(CurCall.getCalleeFunc());
else
CurCall.getCalleeNode()->addFullFunctionList(CallTargets);
for (unsigned c = 0; c != CallTargets.size(); ) {
// If we can eliminate this function call, do so!
const Function *F = CallTargets[c];
if (!F->isDeclaration()) {
ResolveFunctionCall(F, CurCall, ResultGraph->getReturnNodes()[F]);
CallTargets[c] = CallTargets.back();
CallTargets.pop_back();
} else
++c; // Cannot eliminate this call, skip over it...
}
if (CallTargets.empty()) { // Eliminated all calls?
std::list<DSCallSite>::iterator I = CI;
Calls.erase(--I); // Remove entry
}
}
// Remove our knowledge of what the return values of the functions are, except
// for functions that are externally visible from this module (e.g. main). We
// keep these functions so that their arguments are marked incomplete.
for (DSGraph::ReturnNodesTy::iterator I =
ResultGraph->getReturnNodes().begin(),
E = ResultGraph->getReturnNodes().end(); I != E; )
if (I->first->hasInternalLinkage())
ResultGraph->getReturnNodes().erase(I++);
else
++I;
// Update the "incomplete" markers on the nodes, ignoring unknownness due to
// incoming arguments...
ResultGraph->maskIncompleteMarkers();
ResultGraph->markIncompleteNodes(DSGraph::MarkFormalArgs | DSGraph::IgnoreGlobals);
// Remove any nodes that are dead after all of the merging we have done...
ResultGraph->removeDeadNodes(DSGraph::KeepUnreachableGlobals);
GlobalsGraph->removeTriviallyDeadNodes(true);
GlobalsGraph->maskIncompleteMarkers();
// Mark external globals incomplete.
GlobalsGraph->markIncompleteNodes(DSGraph::IgnoreGlobals);
formGlobalECs();
// Clone the global nodes into this graph.
ReachabilityCloner RC(ResultGraph, GlobalsGraph,
DSGraph::DontCloneCallNodes |
DSGraph::DontCloneAuxCallNodes);
for (DSScalarMap::global_iterator I = GlobalsGraph->getScalarMap().global_begin(),
E = GlobalsGraph->getScalarMap().global_end(); I != E; ++I)
if (isa<GlobalVariable>(*I))
RC.getClonedNH(GlobalsGraph->getNodeForValue(*I));
print(DOUT, &M);
return false;
}
void RTAssociate::replaceCall(CallSite CS, FuncInfo& FI, DataStructures* DS) {
const Function *CF = CS.getCalledFunction();
Instruction *TheCall = CS.getInstruction();
// If the called function is casted from one function type to another, peer
// into the cast instruction and pull out the actual function being called.
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(CS.getCalledValue()))
if (CE->getOpcode() == Instruction::BitCast &&
isa<Function>(CE->getOperand(0)))
CF = cast<Function>(CE->getOperand(0));
if (isa<InlineAsm>(TheCall->getOperand(0))) {
errs() << "INLINE ASM: ignoring. Hoping that's safe.\n";
return;
}
// Ignore calls to NULL pointers.
if (isa<ConstantPointerNull>(CS.getCalledValue())) {
errs() << "WARNING: Ignoring call using NULL function pointer.\n";
return;
}
// We need to figure out which local pool descriptors correspond to the pool
// descriptor arguments passed into the function call. Calculate a mapping
// from callee DSNodes to caller DSNodes. We construct a partial isomophism
// between the graphs to figure out which pool descriptors need to be passed
// in. The roots of this mapping is found from arguments and return values.
//
DSGraph::NodeMapTy NodeMapping;
Instruction *NewCall;
Value *NewCallee;
std::vector<const DSNode*> ArgNodes;
DSGraph *CalleeGraph; // The callee graph
// For indirect callees, find any callee since all DS graphs have been
// merged.
if (CF) { // Direct calls are nice and simple.
DEBUG(errs() << " Handling direct call: " << *TheCall);
FuncInfo *CFI = getFuncInfo(CF);
if (CFI == 0 || CFI->Clone == 0) // Nothing to transform...
return;
NewCallee = CFI->Clone;
ArgNodes = CFI->ArgNodes;
assert ((DS->hasDSGraph (*CF)) && "Function has no ECGraph!\n");
CalleeGraph = DS->getDSGraph(*CF);
} else {
DEBUG(errs() << " Handling indirect call: " << *TheCall);
// Here we fill in CF with one of the possible called functions. Because we
// merged together all of the arguments to all of the functions in the
// equivalence set, it doesn't really matter which one we pick.
// (If the function was cloned, we have to map the cloned call instruction
// in CS back to the original call instruction.)
Instruction *OrigInst =
cast<Instruction>(FI.getOldValueIfAvailable(CS.getInstruction()));
DSCallGraph::callee_iterator I = DS->getCallGraph().callee_begin(CS);
if (I != DS->getCallGraph().callee_end(CS))
CF = *I;
// If we didn't find the callee in the constructed call graph, try
// checking in the DSNode itself.
// This isn't ideal as it means that this call site didn't have inlining
// happen.
if (!CF) {
DSGraph* dg = DS->getDSGraph(*OrigInst->getParent()->getParent());
DSNode* d = dg->getNodeForValue(OrigInst->getOperand(0)).getNode();
assert (d && "No DSNode!\n");
std::vector<const Function*> g;
d->addFullFunctionList(g);
if (g.size()) {
EquivalenceClasses< const GlobalValue *> & EC = dg->getGlobalECs();
for(std::vector<const Function*>::const_iterator ii = g.begin(), ee = g.end();
!CF && ii != ee; ++ii) {
for (EquivalenceClasses<const GlobalValue *>::member_iterator MI = EC.findLeader(*ii);
MI != EC.member_end(); ++MI) // Loop over members in this set.
if ((CF = dyn_cast<Function>(*MI))) {
break;
}
}
}
}
//
// Do an assert unless we're bugpointing something.
//
// if ((UsingBugpoint) && (!CF)) return;
if (!CF)
errs() << "No Graph for CallSite in "
<< TheCall->getParent()->getParent()->getName().str()
<< " originally "
<< OrigInst->getParent()->getParent()->getName().str()
<< "\n";
assert (CF && "No call graph info");
// Get the common graph for the set of functions this call may invoke.
// if (UsingBugpoint && (!(Graphs.hasDSGraph(*CF)))) return;
assert ((DS->hasDSGraph(*CF)) && "Function has no DSGraph!\n");
CalleeGraph = DS->getDSGraph(*CF);
#ifndef NDEBUG
// Verify that all potential callees at call site have the same DS graph.
DSCallGraph::callee_iterator E = DS->getCallGraph().callee_end(CS);
for (; I != E; ++I)
if (!(*I)->isDeclaration())
assert(CalleeGraph == DS->getDSGraph(**I) &&
"Callees at call site do not have a common graph!");
#endif
// Find the DS nodes for the arguments that need to be added, if any.
FuncInfo *CFI = getFuncInfo(CF);
assert(CFI && "No function info for callee at indirect call?");
ArgNodes = CFI->ArgNodes;
if (ArgNodes.empty())
return; // No arguments to add? Transformation is a noop!
// Cast the function pointer to an appropriate type!
std::vector<Type*> ArgTys(ArgNodes.size(), PoolDescPtrTy);
for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
I != E; ++I)
ArgTys.push_back((*I)->getType());
FunctionType *FTy = FunctionType::get(TheCall->getType(), ArgTys, false);
PointerType *PFTy = PointerType::getUnqual(FTy);
// If there are any pool arguments cast the func ptr to the right type.
NewCallee = CastInst::CreatePointerCast(CS.getCalledValue(), PFTy, "tmp", TheCall);
}
Function::const_arg_iterator FAI = CF->arg_begin(), E = CF->arg_end();
CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
for ( ; FAI != E && AI != AE; ++FAI, ++AI)
if (!isa<Constant>(*AI))
DSGraph::computeNodeMapping(CalleeGraph->getNodeForValue(FAI),
FI.getDSNodeHFor(*AI), NodeMapping, false);
assert(AI == AE && "Varargs calls not handled yet!");
// Map the return value as well...
if (isa<PointerType>(TheCall->getType()))
DSGraph::computeNodeMapping(CalleeGraph->getReturnNodeFor(*CF),
FI.getDSNodeHFor(TheCall), NodeMapping, false);
// Okay, now that we have established our mapping, we can figure out which
// pool descriptors to pass in...
std::vector<Value*> Args;
for (unsigned i = 0, e = ArgNodes.size(); i != e; ++i) {
Value *ArgVal = Constant::getNullValue(PoolDescPtrTy);
if (NodeMapping.count(ArgNodes[i]))
if (DSNode *LocalNode = NodeMapping[ArgNodes[i]].getNode())
if (FI.PoolDescriptors.count(LocalNode))
ArgVal = FI.PoolDescriptors.find(LocalNode)->second;
if (isa<Constant > (ArgVal) && cast<Constant > (ArgVal)->isNullValue())
errs() << "WARNING: NULL POOL ARGUMENTS ARE PASSED IN!\n";
Args.push_back(ArgVal);
}
// Add the rest of the arguments...
Args.insert(Args.end(), CS.arg_begin(), CS.arg_end());
//
// There are circumstances where a function is casted to another type and
// then called (que horible). We need to perform a similar cast if the
// type doesn't match the number of arguments.
//
if (Function * NewFunction = dyn_cast<Function>(NewCallee)) {
FunctionType * NewCalleeType = NewFunction->getFunctionType();
if (NewCalleeType->getNumParams() != Args.size()) {
std::vector<Type *> Types;
Type * FuncTy = FunctionType::get (NewCalleeType->getReturnType(),
Types,
true);
FuncTy = PointerType::getUnqual (FuncTy);
NewCallee = new BitCastInst (NewCallee, FuncTy, "", TheCall);
}
}
std::string Name = TheCall->getName(); TheCall->setName("");
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) {
NewCall = InvokeInst::Create (NewCallee, II->getNormalDest(),
II->getUnwindDest(),
Args, Name, TheCall);
} else {
NewCall = CallInst::Create (NewCallee, Args, Name,
TheCall);
}
TheCall->replaceAllUsesWith(NewCall);
DEBUG(errs() << " Result Call: " << *NewCall);
if (TheCall->getType()->getTypeID() != Type::VoidTyID) {
// If we are modifying the original function, update the DSGraph...
DSGraph::ScalarMapTy &SM = FI.G->getScalarMap();
DSGraph::ScalarMapTy::iterator CII = SM.find(TheCall);
if (CII != SM.end()) {
SM[NewCall] = CII->second;
SM.erase(CII); // Destroy the CallInst
} else if (!FI.NewToOldValueMap.empty()) {
// Otherwise, if this is a clone, update the NewToOldValueMap with the new
// CI return value.
FI.UpdateNewToOldValueMap(TheCall, NewCall);
}
} else if (!FI.NewToOldValueMap.empty()) {
FI.UpdateNewToOldValueMap(TheCall, NewCall);
}
//FIXME: attributes on call?
CallSite(NewCall).setCallingConv(CallSite(TheCall).getCallingConv());
TheCall->eraseFromParent();
}
