|  | //===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file is distributed under the University of Illinois Open Source | 
|  | // License. See LICENSE.TXT for details. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // This file implements the CallGraphSCCPass class, which is used for passes | 
|  | // which are implemented as bottom-up traversals on the call graph.  Because | 
|  | // there may be cycles in the call graph, passes of this type operate on the | 
|  | // call-graph in SCC order: that is, they process function bottom-up, except for | 
|  | // recursive functions, which they process all at once. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "llvm/Analysis/CallGraphSCCPass.h" | 
|  | #include "llvm/ADT/DenseMap.h" | 
|  | #include "llvm/ADT/SCCIterator.h" | 
|  | #include "llvm/ADT/Statistic.h" | 
|  | #include "llvm/Analysis/CallGraph.h" | 
|  | #include "llvm/IR/CallSite.h" | 
|  | #include "llvm/IR/Function.h" | 
|  | #include "llvm/IR/Intrinsics.h" | 
|  | #include "llvm/IR/LLVMContext.h" | 
|  | #include "llvm/IR/LegacyPassManagers.h" | 
|  | #include "llvm/IR/Module.h" | 
|  | #include "llvm/IR/OptBisect.h" | 
|  | #include "llvm/Pass.h" | 
|  | #include "llvm/Support/CommandLine.h" | 
|  | #include "llvm/Support/Debug.h" | 
|  | #include "llvm/Support/Timer.h" | 
|  | #include "llvm/Support/raw_ostream.h" | 
|  | #include <cassert> | 
|  | #include <string> | 
|  | #include <utility> | 
|  | #include <vector> | 
|  |  | 
|  | using namespace llvm; | 
|  |  | 
|  | #define DEBUG_TYPE "cgscc-passmgr" | 
|  |  | 
|  | static cl::opt<unsigned> | 
|  | MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4)); | 
|  |  | 
|  | STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC"); | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | // CGPassManager | 
|  | // | 
|  | /// CGPassManager manages FPPassManagers and CallGraphSCCPasses. | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | class CGPassManager : public ModulePass, public PMDataManager { | 
|  | public: | 
|  | static char ID; | 
|  |  | 
|  | explicit CGPassManager() : ModulePass(ID), PMDataManager() {} | 
|  |  | 
|  | /// Execute all of the passes scheduled for execution.  Keep track of | 
|  | /// whether any of the passes modifies the module, and if so, return true. | 
|  | bool runOnModule(Module &M) override; | 
|  |  | 
|  | using ModulePass::doInitialization; | 
|  | using ModulePass::doFinalization; | 
|  |  | 
|  | bool doInitialization(CallGraph &CG); | 
|  | bool doFinalization(CallGraph &CG); | 
|  |  | 
|  | /// Pass Manager itself does not invalidate any analysis info. | 
|  | void getAnalysisUsage(AnalysisUsage &Info) const override { | 
|  | // CGPassManager walks SCC and it needs CallGraph. | 
|  | Info.addRequired<CallGraphWrapperPass>(); | 
|  | Info.setPreservesAll(); | 
|  | } | 
|  |  | 
|  | StringRef getPassName() const override { return "CallGraph Pass Manager"; } | 
|  |  | 
|  | PMDataManager *getAsPMDataManager() override { return this; } | 
|  | Pass *getAsPass() override { return this; } | 
|  |  | 
|  | // Print passes managed by this manager | 
|  | void dumpPassStructure(unsigned Offset) override { | 
|  | errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n"; | 
|  | for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { | 
|  | Pass *P = getContainedPass(Index); | 
|  | P->dumpPassStructure(Offset + 1); | 
|  | dumpLastUses(P, Offset+1); | 
|  | } | 
|  | } | 
|  |  | 
|  | Pass *getContainedPass(unsigned N) { | 
|  | assert(N < PassVector.size() && "Pass number out of range!"); | 
|  | return static_cast<Pass *>(PassVector[N]); | 
|  | } | 
|  |  | 
|  | PassManagerType getPassManagerType() const override { | 
|  | return PMT_CallGraphPassManager; | 
|  | } | 
|  |  | 
|  | private: | 
|  | bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG, | 
|  | bool &DevirtualizedCall); | 
|  |  | 
|  | bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC, | 
|  | CallGraph &CG, bool &CallGraphUpToDate, | 
|  | bool &DevirtualizedCall); | 
|  | bool RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG, | 
|  | bool IsCheckingMode); | 
|  | }; | 
|  |  | 
|  | } // end anonymous namespace. | 
|  |  | 
|  | char CGPassManager::ID = 0; | 
|  |  | 
|  | bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC, | 
|  | CallGraph &CG, bool &CallGraphUpToDate, | 
|  | bool &DevirtualizedCall) { | 
|  | bool Changed = false; | 
|  | PMDataManager *PM = P->getAsPMDataManager(); | 
|  | Module &M = CG.getModule(); | 
|  |  | 
|  | if (!PM) { | 
|  | CallGraphSCCPass *CGSP = (CallGraphSCCPass*)P; | 
|  | if (!CallGraphUpToDate) { | 
|  | DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false); | 
|  | CallGraphUpToDate = true; | 
|  | } | 
|  |  | 
|  | { | 
|  | TimeRegion PassTimer(getPassTimer(CGSP)); | 
|  | unsigned InstrCount = initSizeRemarkInfo(M); | 
|  | Changed = CGSP->runOnSCC(CurSCC); | 
|  |  | 
|  | // If the pass modified the module, it may have modified the instruction | 
|  | // count of the module. Try emitting a remark. | 
|  | emitInstrCountChangedRemark(P, M, InstrCount); | 
|  | } | 
|  |  | 
|  | // After the CGSCCPass is done, when assertions are enabled, use | 
|  | // RefreshCallGraph to verify that the callgraph was correctly updated. | 
|  | #ifndef NDEBUG | 
|  | if (Changed) | 
|  | RefreshCallGraph(CurSCC, CG, true); | 
|  | #endif | 
|  |  | 
|  | return Changed; | 
|  | } | 
|  |  | 
|  | assert(PM->getPassManagerType() == PMT_FunctionPassManager && | 
|  | "Invalid CGPassManager member"); | 
|  | FPPassManager *FPP = (FPPassManager*)P; | 
|  |  | 
|  | // Run pass P on all functions in the current SCC. | 
|  | for (CallGraphNode *CGN : CurSCC) { | 
|  | if (Function *F = CGN->getFunction()) { | 
|  | dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName()); | 
|  | { | 
|  | TimeRegion PassTimer(getPassTimer(FPP)); | 
|  | Changed |= FPP->runOnFunction(*F); | 
|  | } | 
|  | F->getContext().yield(); | 
|  | } | 
|  | } | 
|  |  | 
|  | // The function pass(es) modified the IR, they may have clobbered the | 
|  | // callgraph. | 
|  | if (Changed && CallGraphUpToDate) { | 
|  | LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: " << P->getPassName() | 
|  | << '\n'); | 
|  | CallGraphUpToDate = false; | 
|  | } | 
|  | return Changed; | 
|  | } | 
|  |  | 
|  | /// Scan the functions in the specified CFG and resync the | 
|  | /// callgraph with the call sites found in it.  This is used after | 
|  | /// FunctionPasses have potentially munged the callgraph, and can be used after | 
|  | /// CallGraphSCC passes to verify that they correctly updated the callgraph. | 
|  | /// | 
|  | /// This function returns true if it devirtualized an existing function call, | 
|  | /// meaning it turned an indirect call into a direct call.  This happens when | 
|  | /// a function pass like GVN optimizes away stuff feeding the indirect call. | 
|  | /// This never happens in checking mode. | 
|  | bool CGPassManager::RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG, | 
|  | bool CheckingMode) { | 
|  | DenseMap<Value*, CallGraphNode*> CallSites; | 
|  |  | 
|  | LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size() | 
|  | << " nodes:\n"; | 
|  | for (CallGraphNode *CGN | 
|  | : CurSCC) CGN->dump();); | 
|  |  | 
|  | bool MadeChange = false; | 
|  | bool DevirtualizedCall = false; | 
|  |  | 
|  | // Scan all functions in the SCC. | 
|  | unsigned FunctionNo = 0; | 
|  | for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end(); | 
|  | SCCIdx != E; ++SCCIdx, ++FunctionNo) { | 
|  | CallGraphNode *CGN = *SCCIdx; | 
|  | Function *F = CGN->getFunction(); | 
|  | if (!F || F->isDeclaration()) continue; | 
|  |  | 
|  | // Walk the function body looking for call sites.  Sync up the call sites in | 
|  | // CGN with those actually in the function. | 
|  |  | 
|  | // Keep track of the number of direct and indirect calls that were | 
|  | // invalidated and removed. | 
|  | unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0; | 
|  |  | 
|  | // Get the set of call sites currently in the function. | 
|  | for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ) { | 
|  | // If this call site is null, then the function pass deleted the call | 
|  | // entirely and the WeakTrackingVH nulled it out. | 
|  | if (!I->first || | 
|  | // If we've already seen this call site, then the FunctionPass RAUW'd | 
|  | // one call with another, which resulted in two "uses" in the edge | 
|  | // list of the same call. | 
|  | CallSites.count(I->first) || | 
|  |  | 
|  | // If the call edge is not from a call or invoke, or it is a | 
|  | // instrinsic call, then the function pass RAUW'd a call with | 
|  | // another value. This can happen when constant folding happens | 
|  | // of well known functions etc. | 
|  | !CallSite(I->first) || | 
|  | (CallSite(I->first).getCalledFunction() && | 
|  | CallSite(I->first).getCalledFunction()->isIntrinsic() && | 
|  | Intrinsic::isLeaf( | 
|  | CallSite(I->first).getCalledFunction()->getIntrinsicID()))) { | 
|  | assert(!CheckingMode && | 
|  | "CallGraphSCCPass did not update the CallGraph correctly!"); | 
|  |  | 
|  | // If this was an indirect call site, count it. | 
|  | if (!I->second->getFunction()) | 
|  | ++NumIndirectRemoved; | 
|  | else | 
|  | ++NumDirectRemoved; | 
|  |  | 
|  | // Just remove the edge from the set of callees, keep track of whether | 
|  | // I points to the last element of the vector. | 
|  | bool WasLast = I + 1 == E; | 
|  | CGN->removeCallEdge(I); | 
|  |  | 
|  | // If I pointed to the last element of the vector, we have to bail out: | 
|  | // iterator checking rejects comparisons of the resultant pointer with | 
|  | // end. | 
|  | if (WasLast) | 
|  | break; | 
|  | E = CGN->end(); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | assert(!CallSites.count(I->first) && | 
|  | "Call site occurs in node multiple times"); | 
|  |  | 
|  | CallSite CS(I->first); | 
|  | if (CS) { | 
|  | Function *Callee = CS.getCalledFunction(); | 
|  | // Ignore intrinsics because they're not really function calls. | 
|  | if (!Callee || !(Callee->isIntrinsic())) | 
|  | CallSites.insert(std::make_pair(I->first, I->second)); | 
|  | } | 
|  | ++I; | 
|  | } | 
|  |  | 
|  | // Loop over all of the instructions in the function, getting the callsites. | 
|  | // Keep track of the number of direct/indirect calls added. | 
|  | unsigned NumDirectAdded = 0, NumIndirectAdded = 0; | 
|  |  | 
|  | for (BasicBlock &BB : *F) | 
|  | for (Instruction &I : BB) { | 
|  | CallSite CS(&I); | 
|  | if (!CS) continue; | 
|  | Function *Callee = CS.getCalledFunction(); | 
|  | if (Callee && Callee->isIntrinsic()) continue; | 
|  |  | 
|  | // If this call site already existed in the callgraph, just verify it | 
|  | // matches up to expectations and remove it from CallSites. | 
|  | DenseMap<Value*, CallGraphNode*>::iterator ExistingIt = | 
|  | CallSites.find(CS.getInstruction()); | 
|  | if (ExistingIt != CallSites.end()) { | 
|  | CallGraphNode *ExistingNode = ExistingIt->second; | 
|  |  | 
|  | // Remove from CallSites since we have now seen it. | 
|  | CallSites.erase(ExistingIt); | 
|  |  | 
|  | // Verify that the callee is right. | 
|  | if (ExistingNode->getFunction() == CS.getCalledFunction()) | 
|  | continue; | 
|  |  | 
|  | // If we are in checking mode, we are not allowed to actually mutate | 
|  | // the callgraph.  If this is a case where we can infer that the | 
|  | // callgraph is less precise than it could be (e.g. an indirect call | 
|  | // site could be turned direct), don't reject it in checking mode, and | 
|  | // don't tweak it to be more precise. | 
|  | if (CheckingMode && CS.getCalledFunction() && | 
|  | ExistingNode->getFunction() == nullptr) | 
|  | continue; | 
|  |  | 
|  | assert(!CheckingMode && | 
|  | "CallGraphSCCPass did not update the CallGraph correctly!"); | 
|  |  | 
|  | // If not, we either went from a direct call to indirect, indirect to | 
|  | // direct, or direct to different direct. | 
|  | CallGraphNode *CalleeNode; | 
|  | if (Function *Callee = CS.getCalledFunction()) { | 
|  | CalleeNode = CG.getOrInsertFunction(Callee); | 
|  | // Keep track of whether we turned an indirect call into a direct | 
|  | // one. | 
|  | if (!ExistingNode->getFunction()) { | 
|  | DevirtualizedCall = true; | 
|  | LLVM_DEBUG(dbgs() << "  CGSCCPASSMGR: Devirtualized call to '" | 
|  | << Callee->getName() << "'\n"); | 
|  | } | 
|  | } else { | 
|  | CalleeNode = CG.getCallsExternalNode(); | 
|  | } | 
|  |  | 
|  | // Update the edge target in CGN. | 
|  | CGN->replaceCallEdge(CS, CS, CalleeNode); | 
|  | MadeChange = true; | 
|  | continue; | 
|  | } | 
|  |  | 
|  | assert(!CheckingMode && | 
|  | "CallGraphSCCPass did not update the CallGraph correctly!"); | 
|  |  | 
|  | // If the call site didn't exist in the CGN yet, add it. | 
|  | CallGraphNode *CalleeNode; | 
|  | if (Function *Callee = CS.getCalledFunction()) { | 
|  | CalleeNode = CG.getOrInsertFunction(Callee); | 
|  | ++NumDirectAdded; | 
|  | } else { | 
|  | CalleeNode = CG.getCallsExternalNode(); | 
|  | ++NumIndirectAdded; | 
|  | } | 
|  |  | 
|  | CGN->addCalledFunction(CS, CalleeNode); | 
|  | MadeChange = true; | 
|  | } | 
|  |  | 
|  | // We scanned the old callgraph node, removing invalidated call sites and | 
|  | // then added back newly found call sites.  One thing that can happen is | 
|  | // that an old indirect call site was deleted and replaced with a new direct | 
|  | // call.  In this case, we have devirtualized a call, and CGSCCPM would like | 
|  | // to iteratively optimize the new code.  Unfortunately, we don't really | 
|  | // have a great way to detect when this happens.  As an approximation, we | 
|  | // just look at whether the number of indirect calls is reduced and the | 
|  | // number of direct calls is increased.  There are tons of ways to fool this | 
|  | // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a | 
|  | // direct call) but this is close enough. | 
|  | if (NumIndirectRemoved > NumIndirectAdded && | 
|  | NumDirectRemoved < NumDirectAdded) | 
|  | DevirtualizedCall = true; | 
|  |  | 
|  | // After scanning this function, if we still have entries in callsites, then | 
|  | // they are dangling pointers.  WeakTrackingVH should save us for this, so | 
|  | // abort if | 
|  | // this happens. | 
|  | assert(CallSites.empty() && "Dangling pointers found in call sites map"); | 
|  |  | 
|  | // Periodically do an explicit clear to remove tombstones when processing | 
|  | // large scc's. | 
|  | if ((FunctionNo & 15) == 15) | 
|  | CallSites.clear(); | 
|  | } | 
|  |  | 
|  | LLVM_DEBUG(if (MadeChange) { | 
|  | dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n"; | 
|  | for (CallGraphNode *CGN : CurSCC) | 
|  | CGN->dump(); | 
|  | if (DevirtualizedCall) | 
|  | dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n"; | 
|  | } else { | 
|  | dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n"; | 
|  | }); | 
|  | (void)MadeChange; | 
|  |  | 
|  | return DevirtualizedCall; | 
|  | } | 
|  |  | 
|  | /// Execute the body of the entire pass manager on the specified SCC. | 
|  | /// This keeps track of whether a function pass devirtualizes | 
|  | /// any calls and returns it in DevirtualizedCall. | 
|  | bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG, | 
|  | bool &DevirtualizedCall) { | 
|  | bool Changed = false; | 
|  |  | 
|  | // Keep track of whether the callgraph is known to be up-to-date or not. | 
|  | // The CGSSC pass manager runs two types of passes: | 
|  | // CallGraphSCC Passes and other random function passes.  Because other | 
|  | // random function passes are not CallGraph aware, they may clobber the | 
|  | // call graph by introducing new calls or deleting other ones.  This flag | 
|  | // is set to false when we run a function pass so that we know to clean up | 
|  | // the callgraph when we need to run a CGSCCPass again. | 
|  | bool CallGraphUpToDate = true; | 
|  |  | 
|  | // Run all passes on current SCC. | 
|  | for (unsigned PassNo = 0, e = getNumContainedPasses(); | 
|  | PassNo != e; ++PassNo) { | 
|  | Pass *P = getContainedPass(PassNo); | 
|  |  | 
|  | // If we're in -debug-pass=Executions mode, construct the SCC node list, | 
|  | // otherwise avoid constructing this string as it is expensive. | 
|  | if (isPassDebuggingExecutionsOrMore()) { | 
|  | std::string Functions; | 
|  | #ifndef NDEBUG | 
|  | raw_string_ostream OS(Functions); | 
|  | for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end(); | 
|  | I != E; ++I) { | 
|  | if (I != CurSCC.begin()) OS << ", "; | 
|  | (*I)->print(OS); | 
|  | } | 
|  | OS.flush(); | 
|  | #endif | 
|  | dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions); | 
|  | } | 
|  | dumpRequiredSet(P); | 
|  |  | 
|  | initializeAnalysisImpl(P); | 
|  |  | 
|  | // Actually run this pass on the current SCC. | 
|  | Changed |= RunPassOnSCC(P, CurSCC, CG, | 
|  | CallGraphUpToDate, DevirtualizedCall); | 
|  |  | 
|  | if (Changed) | 
|  | dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, ""); | 
|  | dumpPreservedSet(P); | 
|  |  | 
|  | verifyPreservedAnalysis(P); | 
|  | removeNotPreservedAnalysis(P); | 
|  | recordAvailableAnalysis(P); | 
|  | removeDeadPasses(P, "", ON_CG_MSG); | 
|  | } | 
|  |  | 
|  | // If the callgraph was left out of date (because the last pass run was a | 
|  | // functionpass), refresh it before we move on to the next SCC. | 
|  | if (!CallGraphUpToDate) | 
|  | DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false); | 
|  | return Changed; | 
|  | } | 
|  |  | 
|  | /// Execute all of the passes scheduled for execution.  Keep track of | 
|  | /// whether any of the passes modifies the module, and if so, return true. | 
|  | bool CGPassManager::runOnModule(Module &M) { | 
|  | CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph(); | 
|  | bool Changed = doInitialization(CG); | 
|  |  | 
|  | // Walk the callgraph in bottom-up SCC order. | 
|  | scc_iterator<CallGraph*> CGI = scc_begin(&CG); | 
|  |  | 
|  | CallGraphSCC CurSCC(CG, &CGI); | 
|  | while (!CGI.isAtEnd()) { | 
|  | // Copy the current SCC and increment past it so that the pass can hack | 
|  | // on the SCC if it wants to without invalidating our iterator. | 
|  | const std::vector<CallGraphNode *> &NodeVec = *CGI; | 
|  | CurSCC.initialize(NodeVec); | 
|  | ++CGI; | 
|  |  | 
|  | // At the top level, we run all the passes in this pass manager on the | 
|  | // functions in this SCC.  However, we support iterative compilation in the | 
|  | // case where a function pass devirtualizes a call to a function.  For | 
|  | // example, it is very common for a function pass (often GVN or instcombine) | 
|  | // to eliminate the addressing that feeds into a call.  With that improved | 
|  | // information, we would like the call to be an inline candidate, infer | 
|  | // mod-ref information etc. | 
|  | // | 
|  | // Because of this, we allow iteration up to a specified iteration count. | 
|  | // This only happens in the case of a devirtualized call, so we only burn | 
|  | // compile time in the case that we're making progress.  We also have a hard | 
|  | // iteration count limit in case there is crazy code. | 
|  | unsigned Iteration = 0; | 
|  | bool DevirtualizedCall = false; | 
|  | do { | 
|  | LLVM_DEBUG(if (Iteration) dbgs() | 
|  | << "  SCCPASSMGR: Re-visiting SCC, iteration #" << Iteration | 
|  | << '\n'); | 
|  | DevirtualizedCall = false; | 
|  | Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall); | 
|  | } while (Iteration++ < MaxIterations && DevirtualizedCall); | 
|  |  | 
|  | if (DevirtualizedCall) | 
|  | LLVM_DEBUG(dbgs() << "  CGSCCPASSMGR: Stopped iteration after " | 
|  | << Iteration | 
|  | << " times, due to -max-cg-scc-iterations\n"); | 
|  |  | 
|  | MaxSCCIterations.updateMax(Iteration); | 
|  | } | 
|  | Changed |= doFinalization(CG); | 
|  | return Changed; | 
|  | } | 
|  |  | 
|  | /// Initialize CG | 
|  | bool CGPassManager::doInitialization(CallGraph &CG) { | 
|  | bool Changed = false; | 
|  | for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) { | 
|  | if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) { | 
|  | assert(PM->getPassManagerType() == PMT_FunctionPassManager && | 
|  | "Invalid CGPassManager member"); | 
|  | Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule()); | 
|  | } else { | 
|  | Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG); | 
|  | } | 
|  | } | 
|  | return Changed; | 
|  | } | 
|  |  | 
|  | /// Finalize CG | 
|  | bool CGPassManager::doFinalization(CallGraph &CG) { | 
|  | bool Changed = false; | 
|  | for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) { | 
|  | if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) { | 
|  | assert(PM->getPassManagerType() == PMT_FunctionPassManager && | 
|  | "Invalid CGPassManager member"); | 
|  | Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule()); | 
|  | } else { | 
|  | Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG); | 
|  | } | 
|  | } | 
|  | return Changed; | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | // CallGraphSCC Implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | /// This informs the SCC and the pass manager that the specified | 
|  | /// Old node has been deleted, and New is to be used in its place. | 
|  | void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) { | 
|  | assert(Old != New && "Should not replace node with self"); | 
|  | for (unsigned i = 0; ; ++i) { | 
|  | assert(i != Nodes.size() && "Node not in SCC"); | 
|  | if (Nodes[i] != Old) continue; | 
|  | Nodes[i] = New; | 
|  | break; | 
|  | } | 
|  |  | 
|  | // Update the active scc_iterator so that it doesn't contain dangling | 
|  | // pointers to the old CallGraphNode. | 
|  | scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context; | 
|  | CGI->ReplaceNode(Old, New); | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | // CallGraphSCCPass Implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | /// Assign pass manager to manage this pass. | 
|  | void CallGraphSCCPass::assignPassManager(PMStack &PMS, | 
|  | PassManagerType PreferredType) { | 
|  | // Find CGPassManager | 
|  | while (!PMS.empty() && | 
|  | PMS.top()->getPassManagerType() > PMT_CallGraphPassManager) | 
|  | PMS.pop(); | 
|  |  | 
|  | assert(!PMS.empty() && "Unable to handle Call Graph Pass"); | 
|  | CGPassManager *CGP; | 
|  |  | 
|  | if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager) | 
|  | CGP = (CGPassManager*)PMS.top(); | 
|  | else { | 
|  | // Create new Call Graph SCC Pass Manager if it does not exist. | 
|  | assert(!PMS.empty() && "Unable to create Call Graph Pass Manager"); | 
|  | PMDataManager *PMD = PMS.top(); | 
|  |  | 
|  | // [1] Create new Call Graph Pass Manager | 
|  | CGP = new CGPassManager(); | 
|  |  | 
|  | // [2] Set up new manager's top level manager | 
|  | PMTopLevelManager *TPM = PMD->getTopLevelManager(); | 
|  | TPM->addIndirectPassManager(CGP); | 
|  |  | 
|  | // [3] Assign manager to manage this new manager. This may create | 
|  | // and push new managers into PMS | 
|  | Pass *P = CGP; | 
|  | TPM->schedulePass(P); | 
|  |  | 
|  | // [4] Push new manager into PMS | 
|  | PMS.push(CGP); | 
|  | } | 
|  |  | 
|  | CGP->add(this); | 
|  | } | 
|  |  | 
|  | /// For this class, we declare that we require and preserve the call graph. | 
|  | /// If the derived class implements this method, it should | 
|  | /// always explicitly call the implementation here. | 
|  | void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const { | 
|  | AU.addRequired<CallGraphWrapperPass>(); | 
|  | AU.addPreserved<CallGraphWrapperPass>(); | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | // PrintCallGraphPass Implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | /// PrintCallGraphPass - Print a Module corresponding to a call graph. | 
|  | /// | 
|  | class PrintCallGraphPass : public CallGraphSCCPass { | 
|  | std::string Banner; | 
|  | raw_ostream &OS;       // raw_ostream to print on. | 
|  |  | 
|  | public: | 
|  | static char ID; | 
|  |  | 
|  | PrintCallGraphPass(const std::string &B, raw_ostream &OS) | 
|  | : CallGraphSCCPass(ID), Banner(B), OS(OS) {} | 
|  |  | 
|  | void getAnalysisUsage(AnalysisUsage &AU) const override { | 
|  | AU.setPreservesAll(); | 
|  | } | 
|  |  | 
|  | bool runOnSCC(CallGraphSCC &SCC) override { | 
|  | bool BannerPrinted = false; | 
|  | auto PrintBannerOnce = [&] () { | 
|  | if (BannerPrinted) | 
|  | return; | 
|  | OS << Banner; | 
|  | BannerPrinted = true; | 
|  | }; | 
|  | for (CallGraphNode *CGN : SCC) { | 
|  | if (Function *F = CGN->getFunction()) { | 
|  | if (!F->isDeclaration() && isFunctionInPrintList(F->getName())) { | 
|  | PrintBannerOnce(); | 
|  | F->print(OS); | 
|  | } | 
|  | } else if (isFunctionInPrintList("*")) { | 
|  | PrintBannerOnce(); | 
|  | OS << "\nPrinting <null> Function\n"; | 
|  | } | 
|  | } | 
|  | return false; | 
|  | } | 
|  |  | 
|  | StringRef getPassName() const override { return "Print CallGraph IR"; } | 
|  | }; | 
|  |  | 
|  | } // end anonymous namespace. | 
|  |  | 
|  | char PrintCallGraphPass::ID = 0; | 
|  |  | 
|  | Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &OS, | 
|  | const std::string &Banner) const { | 
|  | return new PrintCallGraphPass(Banner, OS); | 
|  | } | 
|  |  | 
|  | bool CallGraphSCCPass::skipSCC(CallGraphSCC &SCC) const { | 
|  | return !SCC.getCallGraph().getModule() | 
|  | .getContext() | 
|  | .getOptPassGate() | 
|  | .shouldRunPass(this, SCC); | 
|  | } | 
|  |  | 
|  | char DummyCGSCCPass::ID = 0; | 
|  |  | 
|  | INITIALIZE_PASS(DummyCGSCCPass, "DummyCGSCCPass", "DummyCGSCCPass", false, | 
|  | false) |