// BU:
// Construct the callgraph from the local graphs
// Find SCCs
// inline bottom up
//
bool BUDataStructures::runOnModuleInternal(Module& M) {
//
// Make sure we have a DSGraph for all declared functions in the Module.
// While we may not need them in this DSA pass, a later DSA pass may ask us
// for their DSGraphs, and we want to have them if asked.
//
for (Function &F : M) {
if (!(F.isDeclaration())){
getOrCreateGraph(&F);
}
}
//
// Do a post-order traversal of the SCC callgraph and do bottom-up inlining.
//
postOrderInline (M);
// At the end of the bottom-up pass, the globals graph becomes complete.
// FIXME: This is not the right way to do this, but it is sorta better than
// nothing! In particular, externally visible globals and unresolvable call
// nodes at the end of the BU phase should make things that they point to
// incomplete in the globals graph.
//
GlobalsGraph->removeTriviallyDeadNodes();
GlobalsGraph->maskIncompleteMarkers();
// Mark external globals incomplete.
GlobalsGraph->markIncompleteNodes(DSGraph::IgnoreGlobals);
GlobalsGraph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
GlobalsGraph->computeIntPtrFlags();
//
// Create equivalence classes for aliasing globals so that we only need to
// record one global per DSNode.
//
formGlobalECs();
// Merge the globals variables (not the calls) from the globals graph back
// into the individual function's graph so that changes made to globals during
// BU can be reflected. This is specifically needed for correct call graph
//
for (Function &F : M) {
if (!(F.isDeclaration())){
DSGraph *Graph = getOrCreateGraph(&F);
cloneGlobalsInto(Graph, DSGraph::DontCloneCallNodes |
DSGraph::DontCloneAuxCallNodes);
Graph->buildCallGraph(callgraph, GlobalFunctionList, filterCallees);
Graph->maskIncompleteMarkers();
Graph->markIncompleteNodes(DSGraph::MarkFormalArgs |
DSGraph::IgnoreGlobals);
Graph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
Graph->computeIntPtrFlags();
}
}
// Once the correct flags have been calculated. Update the callgraph.
for (Function &F : M) {
if (!(F.isDeclaration())){
DSGraph *Graph = getOrCreateGraph(&F);
Graph->buildCompleteCallGraph(callgraph,
GlobalFunctionList, filterCallees);
}
}
NumCallEdges += callgraph.size();
// Put the call graph in canonical form
callgraph.buildSCCs();
callgraph.buildRoots();
DEBUG(print(errs(), &M));
return false;
}
bool
StdLibDataStructures::runOnModule (Module &M) {
//
// Get the results from the local pass.
//
init (&getAnalysis<LocalDataStructures>(), true, true, false, false);
AllocWrappersAnalysis = &getAnalysis<AllocIdentify>();
//
// Fetch the DSGraphs for all defined functions within the module.
//
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isDeclaration())
getOrCreateGraph(&*I);
//
// Erase direct calls to functions that don't return a pointer and are marked
// with the readnone annotation.
//
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (I->isDeclaration() && I->doesNotAccessMemory() &&
!isa<PointerType>(I->getReturnType()))
eraseCallsTo(I);
//
// Erase direct calls to external functions that are not varargs, do not
// return a pointer, and do not take pointers.
//
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (I->isDeclaration() && !I->isVarArg() &&
!isa<PointerType>(I->getReturnType())) {
bool hasPtr = false;
for (Function::arg_iterator ii = I->arg_begin(), ee = I->arg_end();
ii != ee;
++ii)
if (isa<PointerType>(ii->getType())) {
hasPtr = true;
break;
}
if (!hasPtr)
eraseCallsTo(I);
}
if(!DisableStdLib) {
//
// Scan through the function summaries and process functions by summary.
//
for (int x = 0; recFuncs[x].name; ++x)
if (Function* F = M.getFunction(recFuncs[x].name))
if (F->isDeclaration()) {
processFunction(x, F);
}
std::set<std::string>::iterator ai = AllocWrappersAnalysis->alloc_begin();
std::set<std::string>::iterator ae = AllocWrappersAnalysis->alloc_end();
int x;
for (x = 0; recFuncs[x].name; ++x) {
if(recFuncs[x].name == std::string("malloc"))
break;
}
for(;ai != ae; ++ai) {
if(Function* F = M.getFunction(*ai))
processFunction(x, F);
}
ai = AllocWrappersAnalysis->dealloc_begin();
ae = AllocWrappersAnalysis->dealloc_end();
for (x = 0; recFuncs[x].name; ++x) {
if(recFuncs[x].name == std::string("free"))
break;
}
for(;ai != ae; ++ai) {
if(Function* F = M.getFunction(*ai))
processFunction(x, F);
}
//
// Merge return values and checked pointer values for SAFECode run-time
// checks.
//
processRuntimeCheck (M, "boundscheck", 2);
processRuntimeCheck (M, "boundscheckui", 2);
processRuntimeCheck (M, "exactcheck2", 1);
processRuntimeCheck (M, "boundscheck_debug", 2);
processRuntimeCheck (M, "boundscheckui_debug", 2);
processRuntimeCheck (M, "exactcheck2_debug", 1);
processRuntimeCheck (M, "pchk_getActualValue", 1);
}
//
// In the Local DSA Pass, we marked nodes passed to/returned from 'StdLib'
// functions as External because, at that point, they were. However, they no
// longer are necessarily External, and we need to update accordingly.
//
GlobalsGraph->maskIncompleteMarkers();
GlobalsGraph->computeExternalFlags(DSGraph::ResetExternal);
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isDeclaration()) {
DSGraph * G = getDSGraph(*I);
unsigned EFlags = 0
| DSGraph::ResetExternal
| DSGraph::DontMarkFormalsExternal
| DSGraph::ProcessCallSites;
G->maskIncompleteMarkers();
G->markIncompleteNodes(DSGraph::MarkFormalArgs
|DSGraph::IgnoreGlobals);
G->computeExternalFlags(EFlags);
DEBUG(G->AssertGraphOK());
}
GlobalsGraph->markIncompleteNodes(DSGraph::MarkFormalArgs
|DSGraph::IgnoreGlobals);
GlobalsGraph->computeExternalFlags(DSGraph::ProcessCallSites);
DEBUG(GlobalsGraph->AssertGraphOK());
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isDeclaration()) {
DSGraph *Graph = getOrCreateGraph(I);
Graph->maskIncompleteMarkers();
cloneGlobalsInto(Graph, DSGraph::DontCloneCallNodes |
DSGraph::DontCloneAuxCallNodes);
Graph->markIncompleteNodes(DSGraph::MarkFormalArgs
|DSGraph::IgnoreGlobals);
}
return false;
}
//
// Method: postOrderInline()
//
// Description:
// This methods does a post order traversal of the call graph and performs
// bottom-up inlining of the DSGraphs.
//
void
BUDataStructures::postOrderInline (Module & M) {
// Variables used for Tarjan SCC-finding algorithm. These are passed into
// the recursive function used to find SCCs.
std::vector<const Function*> Stack;
std::map<const Function*, unsigned> ValMap;
unsigned NextID = 1;
// Do post order traversal on the global ctors. Use this information to update
// the globals graph.
const char *Name = "llvm.global_ctors";
GlobalVariable *GV = M.getNamedGlobal(Name);
if (GV && !(GV->isDeclaration()) && !(GV->hasLocalLinkage())) {
// Should be an array of '{ int, void ()* }' structs. The first value is
// the init priority, which we ignore.
ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
if (InitList) {
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))) {
if (CS->getNumOperands() != 2)
break; // Not array of 2-element structs.
Constant *FP = CS->getOperand(1);
if (FP->isNullValue())
break; // Found a null terminator, exit.
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
if (CE->isCast())
FP = CE->getOperand(0);
Function *F = dyn_cast<Function>(FP);
if (F && !F->isDeclaration() && !ValMap.count(F)) {
calculateGraphs(F, Stack, NextID, ValMap);
CloneAuxIntoGlobal(getDSGraph(*F));
}
}
GlobalsGraph->removeTriviallyDeadNodes();
GlobalsGraph->maskIncompleteMarkers();
// Mark external globals incomplete.
GlobalsGraph->markIncompleteNodes(DSGraph::IgnoreGlobals);
GlobalsGraph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
GlobalsGraph->computeIntPtrFlags();
//
// Create equivalence classes for aliasing globals so that we only need to
// record one global per DSNode.
//
formGlobalECs();
// propogte information calculated
// from the globals graph to the other graphs.
for (Module::iterator F = M.begin(); F != M.end(); ++F) {
if (!(F->isDeclaration())){
DSGraph *Graph = getDSGraph(*F);
cloneGlobalsInto(Graph, DSGraph::DontCloneCallNodes |
DSGraph::DontCloneAuxCallNodes);
Graph->buildCallGraph(callgraph, GlobalFunctionList, filterCallees);
Graph->maskIncompleteMarkers();
Graph->markIncompleteNodes(DSGraph::MarkFormalArgs |
DSGraph::IgnoreGlobals);
Graph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
Graph->computeIntPtrFlags();
}
}
}
}
//
// Start the post order traversal with the main() function. If there is no
// main() function, don't worry; we'll have a separate traversal for inlining
// graphs for functions not reachable from main().
//
Function *MainFunc = M.getFunction ("main");
if (MainFunc && !MainFunc->isDeclaration()) {
calculateGraphs(MainFunc, Stack, NextID, ValMap);
CloneAuxIntoGlobal(getDSGraph(*MainFunc));
}
//
// Calculate the graphs for any functions that are unreachable from main...
//
for (Function &F : M)
if (!F.isDeclaration() && !ValMap.count(&F)) {
if (MainFunc)
DEBUG(errs() << debugname << ": Function unreachable from main: "
<< F.getName() << "\n");
calculateGraphs(&F, Stack, NextID, ValMap); // Calculate all graphs.
CloneAuxIntoGlobal(getDSGraph(F));
// Mark this graph as processed. Do this by finding all functions
// in the graph that map to it, and mark them visited.
// Note that this really should be handled neatly by calculateGraphs
// itself, not here. However this catches the worst offenders.
DSGraph *G = getDSGraph(F);
for(DSGraph::retnodes_iterator RI = G->retnodes_begin(),
RE = G->retnodes_end(); RI != RE; ++RI) {
if (getDSGraph(*RI->first) == G) {
if (!ValMap.count(RI->first))
ValMap[RI->first] = ~0U;
else
assert(ValMap[RI->first] == ~0U);
}
}
}
return;
}
bool BUDataStructures::runOnModuleInternal(Module& M) {
std::vector<const Function*> Stack;
hash_map<const Function*, unsigned> ValMap;
unsigned NextID = 1;
Function *MainFunc = M.getFunction("main");
if (MainFunc && !MainFunc->isDeclaration()) {
calculateGraphs(MainFunc, Stack, NextID, ValMap);
CloneAuxIntoGlobal(getDSGraph(MainFunc));
} else {
DEBUG(errs() << debugname << ": No 'main' function found!\n");
}
// Calculate the graphs for any functions that are unreachable from main...
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isDeclaration() && !hasDSGraph(I)) {
if (MainFunc)
DEBUG(errs() << debugname << ": Function unreachable from main: "
<< I->getName() << "\n");
calculateGraphs(I, Stack, NextID, ValMap); // Calculate all graphs.
CloneAuxIntoGlobal(getDSGraph(I));
}
// If we computed any temporary indcallgraphs, free them now.
for (std::map<std::vector<const Function*>,
std::pair<DSGraph*, std::vector<DSNodeHandle> > >::iterator I =
IndCallGraphMap.begin(), E = IndCallGraphMap.end(); I != E; ++I) {
I->second.second.clear(); // Drop arg refs into the graph.
delete I->second.first;
}
IndCallGraphMap.clear();
// At the end of the bottom-up pass, the globals graph becomes complete.
// FIXME: This is not the right way to do this, but it is sorta better than
// nothing! In particular, externally visible globals and unresolvable call
// nodes at the end of the BU phase should make things that they point to
// incomplete in the globals graph.
//
finalizeGlobals();
GlobalsGraph->removeTriviallyDeadNodes(true);
GlobalsGraph->maskIncompleteMarkers();
// Mark external globals incomplete.
GlobalsGraph->markIncompleteNodes(DSGraph::IgnoreGlobals);
formGlobalECs();
// Merge the globals variables (not the calls) from the globals graph back
// into the main function's graph so that the main function contains all of
// the information about global pools and GV usage in the program.
if (MainFunc && !MainFunc->isDeclaration()) {
DSGraph* MainGraph = getDSGraph(MainFunc);
const DSGraph* GG = MainGraph->getGlobalsGraph();
ReachabilityCloner RC(MainGraph, GG,
DSGraph::DontCloneCallNodes |
DSGraph::DontCloneAuxCallNodes);
// Clone the global nodes into this graph.
for (DSScalarMap::global_iterator I = GG->getScalarMap().global_begin(),
E = GG->getScalarMap().global_end(); I != E; ++I)
if (isa<GlobalVariable>(*I))
RC.getClonedNH(GG->getNodeForValue(*I));
MainGraph->maskIncompleteMarkers();
MainGraph->markIncompleteNodes(DSGraph::MarkFormalArgs |
DSGraph::IgnoreGlobals);
}
NumCallEdges += callee.size();
return false;
}