731 lines · cpp
1//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements the CallGraphSCCPass class, which is used for passes10// which are implemented as bottom-up traversals on the call graph. Because11// there may be cycles in the call graph, passes of this type operate on the12// call-graph in SCC order: that is, they process function bottom-up, except for13// recursive functions, which they process all at once.14//15//===----------------------------------------------------------------------===//16 17#include "llvm/Analysis/CallGraphSCCPass.h"18#include "llvm/ADT/DenseMap.h"19#include "llvm/ADT/SCCIterator.h"20#include "llvm/ADT/Statistic.h"21#include "llvm/ADT/StringExtras.h"22#include "llvm/Analysis/CallGraph.h"23#include "llvm/IR/AbstractCallSite.h"24#include "llvm/IR/Function.h"25#include "llvm/IR/Intrinsics.h"26#include "llvm/IR/LLVMContext.h"27#include "llvm/IR/LegacyPassManagers.h"28#include "llvm/IR/Module.h"29#include "llvm/IR/PassTimingInfo.h"30#include "llvm/IR/PrintPasses.h"31#include "llvm/Pass.h"32#include "llvm/Support/CommandLine.h"33#include "llvm/Support/Debug.h"34#include "llvm/Support/Timer.h"35#include "llvm/Support/raw_ostream.h"36#include <cassert>37#include <string>38#include <utility>39#include <vector>40 41using namespace llvm;42 43#define DEBUG_TYPE "cgscc-passmgr"44 45namespace llvm {46cl::opt<unsigned> MaxDevirtIterations("max-devirt-iterations", cl::ReallyHidden,47 cl::init(4));48} // namespace llvm49 50STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC");51 52//===----------------------------------------------------------------------===//53// CGPassManager54//55/// CGPassManager manages FPPassManagers and CallGraphSCCPasses.56 57namespace {58 59class CGPassManager : public ModulePass, public PMDataManager {60public:61 static char ID;62 63 explicit CGPassManager() : ModulePass(ID) {}64 65 /// Execute all of the passes scheduled for execution. Keep track of66 /// whether any of the passes modifies the module, and if so, return true.67 bool runOnModule(Module &M) override;68 69 using ModulePass::doInitialization;70 using ModulePass::doFinalization;71 72 bool doInitialization(CallGraph &CG);73 bool doFinalization(CallGraph &CG);74 75 /// Pass Manager itself does not invalidate any analysis info.76 void getAnalysisUsage(AnalysisUsage &Info) const override {77 // CGPassManager walks SCC and it needs CallGraph.78 Info.addRequired<CallGraphWrapperPass>();79 Info.setPreservesAll();80 }81 82 StringRef getPassName() const override { return "CallGraph Pass Manager"; }83 84 PMDataManager *getAsPMDataManager() override { return this; }85 Pass *getAsPass() override { return this; }86 87 // Print passes managed by this manager88 void dumpPassStructure(unsigned Offset) override {89 errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n";90 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {91 Pass *P = getContainedPass(Index);92 P->dumpPassStructure(Offset + 1);93 dumpLastUses(P, Offset+1);94 }95 }96 97 Pass *getContainedPass(unsigned N) {98 assert(N < PassVector.size() && "Pass number out of range!");99 return static_cast<Pass *>(PassVector[N]);100 }101 102 PassManagerType getPassManagerType() const override {103 return PMT_CallGraphPassManager;104 }105 106private:107 bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,108 bool &DevirtualizedCall);109 110 bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,111 CallGraph &CG, bool &CallGraphUpToDate,112 bool &DevirtualizedCall);113 bool RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,114 bool IsCheckingMode);115};116 117} // end anonymous namespace.118 119char CGPassManager::ID = 0;120 121bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,122 CallGraph &CG, bool &CallGraphUpToDate,123 bool &DevirtualizedCall) {124 bool Changed = false;125 PMDataManager *PM = P->getAsPMDataManager();126 Module &M = CG.getModule();127 128 if (!PM) {129 CallGraphSCCPass *CGSP = (CallGraphSCCPass *)P;130 if (!CallGraphUpToDate) {131 DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);132 CallGraphUpToDate = true;133 }134 135 {136 unsigned InstrCount, SCCCount = 0;137 StringMap<std::pair<unsigned, unsigned>> FunctionToInstrCount;138 bool EmitICRemark = M.shouldEmitInstrCountChangedRemark();139 TimeRegion PassTimer(getPassTimer(CGSP));140 if (EmitICRemark)141 InstrCount = initSizeRemarkInfo(M, FunctionToInstrCount);142 Changed = CGSP->runOnSCC(CurSCC);143 144 if (EmitICRemark) {145 // FIXME: Add getInstructionCount to CallGraphSCC.146 SCCCount = M.getInstructionCount();147 // Is there a difference in the number of instructions in the module?148 if (SCCCount != InstrCount) {149 // Yep. Emit a remark and update InstrCount.150 int64_t Delta =151 static_cast<int64_t>(SCCCount) - static_cast<int64_t>(InstrCount);152 emitInstrCountChangedRemark(P, M, Delta, InstrCount,153 FunctionToInstrCount);154 InstrCount = SCCCount;155 }156 }157 }158 159 // After the CGSCCPass is done, when assertions are enabled, use160 // RefreshCallGraph to verify that the callgraph was correctly updated.161#ifndef NDEBUG162 if (Changed)163 RefreshCallGraph(CurSCC, CG, true);164#endif165 166 return Changed;167 }168 169 assert(PM->getPassManagerType() == PMT_FunctionPassManager &&170 "Invalid CGPassManager member");171 FPPassManager *FPP = (FPPassManager*)P;172 173 // Run pass P on all functions in the current SCC.174 for (CallGraphNode *CGN : CurSCC) {175 if (Function *F = CGN->getFunction()) {176 dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());177 {178 TimeRegion PassTimer(getPassTimer(FPP));179 Changed |= FPP->runOnFunction(*F);180 }181 F->getContext().yield();182 }183 }184 185 // The function pass(es) modified the IR, they may have clobbered the186 // callgraph.187 if (Changed && CallGraphUpToDate) {188 LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: " << P->getPassName()189 << '\n');190 CallGraphUpToDate = false;191 }192 return Changed;193}194 195/// Scan the functions in the specified CFG and resync the196/// callgraph with the call sites found in it. This is used after197/// FunctionPasses have potentially munged the callgraph, and can be used after198/// CallGraphSCC passes to verify that they correctly updated the callgraph.199///200/// This function returns true if it devirtualized an existing function call,201/// meaning it turned an indirect call into a direct call. This happens when202/// a function pass like GVN optimizes away stuff feeding the indirect call.203/// This never happens in checking mode.204bool CGPassManager::RefreshCallGraph(const CallGraphSCC &CurSCC, CallGraph &CG,205 bool CheckingMode) {206 DenseMap<Value *, CallGraphNode *> Calls;207 208 LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()209 << " nodes:\n";210 for (CallGraphNode *CGN211 : CurSCC) CGN->dump(););212 213 bool MadeChange = false;214 bool DevirtualizedCall = false;215 216 // Scan all functions in the SCC.217 unsigned FunctionNo = 0;218 for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end();219 SCCIdx != E; ++SCCIdx, ++FunctionNo) {220 CallGraphNode *CGN = *SCCIdx;221 Function *F = CGN->getFunction();222 if (!F || F->isDeclaration()) continue;223 224 // Walk the function body looking for call sites. Sync up the call sites in225 // CGN with those actually in the function.226 227 // Keep track of the number of direct and indirect calls that were228 // invalidated and removed.229 unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0;230 231 CallGraphNode::iterator CGNEnd = CGN->end();232 233 auto RemoveAndCheckForDone = [&](CallGraphNode::iterator I) {234 // Just remove the edge from the set of callees, keep track of whether235 // I points to the last element of the vector.236 bool WasLast = I + 1 == CGNEnd;237 CGN->removeCallEdge(I);238 239 // If I pointed to the last element of the vector, we have to bail out:240 // iterator checking rejects comparisons of the resultant pointer with241 // end.242 if (WasLast)243 return true;244 245 CGNEnd = CGN->end();246 return false;247 };248 249 // Get the set of call sites currently in the function.250 for (CallGraphNode::iterator I = CGN->begin(); I != CGNEnd;) {251 // Delete "reference" call records that do not have call instruction. We252 // reinsert them as needed later. However, keep them in checking mode.253 if (!I->first) {254 if (CheckingMode) {255 ++I;256 continue;257 }258 if (RemoveAndCheckForDone(I))259 break;260 continue;261 }262 263 // If this call site is null, then the function pass deleted the call264 // entirely and the WeakTrackingVH nulled it out.265 auto *Call = dyn_cast_or_null<CallBase>(*I->first);266 if (!Call ||267 // If we've already seen this call site, then the FunctionPass RAUW'd268 // one call with another, which resulted in two "uses" in the edge269 // list of the same call.270 Calls.count(Call)) {271 assert(!CheckingMode &&272 "CallGraphSCCPass did not update the CallGraph correctly!");273 274 // If this was an indirect call site, count it.275 if (!I->second->getFunction())276 ++NumIndirectRemoved;277 else278 ++NumDirectRemoved;279 280 if (RemoveAndCheckForDone(I))281 break;282 continue;283 }284 285 assert(!Calls.count(Call) && "Call site occurs in node multiple times");286 287 if (Call) {288 Function *Callee = Call->getCalledFunction();289 // Ignore intrinsics because they're not really function calls.290 if (!Callee || !(Callee->isIntrinsic()))291 Calls.insert(std::make_pair(Call, I->second));292 }293 ++I;294 }295 296 // Loop over all of the instructions in the function, getting the callsites.297 // Keep track of the number of direct/indirect calls added.298 unsigned NumDirectAdded = 0, NumIndirectAdded = 0;299 300 for (BasicBlock &BB : *F)301 for (Instruction &I : BB) {302 auto *Call = dyn_cast<CallBase>(&I);303 if (!Call)304 continue;305 Function *Callee = Call->getCalledFunction();306 if (Callee && Callee->isIntrinsic())307 continue;308 309 // If we are not in checking mode, insert potential callback calls as310 // references. This is not a requirement but helps to iterate over the311 // functions in the right order.312 if (!CheckingMode) {313 forEachCallbackFunction(*Call, [&](Function *CB) {314 CGN->addCalledFunction(nullptr, CG.getOrInsertFunction(CB));315 });316 }317 318 // If this call site already existed in the callgraph, just verify it319 // matches up to expectations and remove it from Calls.320 DenseMap<Value *, CallGraphNode *>::iterator ExistingIt =321 Calls.find(Call);322 if (ExistingIt != Calls.end()) {323 CallGraphNode *ExistingNode = ExistingIt->second;324 325 // Remove from Calls since we have now seen it.326 Calls.erase(ExistingIt);327 328 // Verify that the callee is right.329 if (ExistingNode->getFunction() == Call->getCalledFunction())330 continue;331 332 // If we are in checking mode, we are not allowed to actually mutate333 // the callgraph. If this is a case where we can infer that the334 // callgraph is less precise than it could be (e.g. an indirect call335 // site could be turned direct), don't reject it in checking mode, and336 // don't tweak it to be more precise.337 if (CheckingMode && Call->getCalledFunction() &&338 ExistingNode->getFunction() == nullptr)339 continue;340 341 assert(!CheckingMode &&342 "CallGraphSCCPass did not update the CallGraph correctly!");343 344 // If not, we either went from a direct call to indirect, indirect to345 // direct, or direct to different direct.346 CallGraphNode *CalleeNode;347 if (Function *Callee = Call->getCalledFunction()) {348 CalleeNode = CG.getOrInsertFunction(Callee);349 // Keep track of whether we turned an indirect call into a direct350 // one.351 if (!ExistingNode->getFunction()) {352 DevirtualizedCall = true;353 LLVM_DEBUG(dbgs() << " CGSCCPASSMGR: Devirtualized call to '"354 << Callee->getName() << "'\n");355 }356 } else {357 CalleeNode = CG.getCallsExternalNode();358 }359 360 // Update the edge target in CGN.361 CGN->replaceCallEdge(*Call, *Call, CalleeNode);362 MadeChange = true;363 continue;364 }365 366 assert(!CheckingMode &&367 "CallGraphSCCPass did not update the CallGraph correctly!");368 369 // If the call site didn't exist in the CGN yet, add it.370 CallGraphNode *CalleeNode;371 if (Function *Callee = Call->getCalledFunction()) {372 CalleeNode = CG.getOrInsertFunction(Callee);373 ++NumDirectAdded;374 } else {375 CalleeNode = CG.getCallsExternalNode();376 ++NumIndirectAdded;377 }378 379 CGN->addCalledFunction(Call, CalleeNode);380 MadeChange = true;381 }382 383 // We scanned the old callgraph node, removing invalidated call sites and384 // then added back newly found call sites. One thing that can happen is385 // that an old indirect call site was deleted and replaced with a new direct386 // call. In this case, we have devirtualized a call, and CGSCCPM would like387 // to iteratively optimize the new code. Unfortunately, we don't really388 // have a great way to detect when this happens. As an approximation, we389 // just look at whether the number of indirect calls is reduced and the390 // number of direct calls is increased. There are tons of ways to fool this391 // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a392 // direct call) but this is close enough.393 if (NumIndirectRemoved > NumIndirectAdded &&394 NumDirectRemoved < NumDirectAdded)395 DevirtualizedCall = true;396 397 // After scanning this function, if we still have entries in callsites, then398 // they are dangling pointers. WeakTrackingVH should save us for this, so399 // abort if400 // this happens.401 assert(Calls.empty() && "Dangling pointers found in call sites map");402 403 // Periodically do an explicit clear to remove tombstones when processing404 // large scc's.405 if ((FunctionNo & 15) == 15)406 Calls.clear();407 }408 409 LLVM_DEBUG(if (MadeChange) {410 dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n";411 for (CallGraphNode *CGN : CurSCC)412 CGN->dump();413 if (DevirtualizedCall)414 dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n";415 } else {416 dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n";417 });418 (void)MadeChange;419 420 return DevirtualizedCall;421}422 423/// Execute the body of the entire pass manager on the specified SCC.424/// This keeps track of whether a function pass devirtualizes425/// any calls and returns it in DevirtualizedCall.426bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,427 bool &DevirtualizedCall) {428 bool Changed = false;429 430 // Keep track of whether the callgraph is known to be up-to-date or not.431 // The CGSSC pass manager runs two types of passes:432 // CallGraphSCC Passes and other random function passes. Because other433 // random function passes are not CallGraph aware, they may clobber the434 // call graph by introducing new calls or deleting other ones. This flag435 // is set to false when we run a function pass so that we know to clean up436 // the callgraph when we need to run a CGSCCPass again.437 bool CallGraphUpToDate = true;438 439 // Run all passes on current SCC.440 for (unsigned PassNo = 0, e = getNumContainedPasses();441 PassNo != e; ++PassNo) {442 Pass *P = getContainedPass(PassNo);443 444 // If we're in -debug-pass=Executions mode, construct the SCC node list,445 // otherwise avoid constructing this string as it is expensive.446 if (isPassDebuggingExecutionsOrMore()) {447 std::string Functions;448 #ifndef NDEBUG449 raw_string_ostream OS(Functions);450 ListSeparator LS;451 for (const CallGraphNode *CGN : CurSCC) {452 OS << LS;453 CGN->print(OS);454 }455 #endif456 dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions);457 }458 dumpRequiredSet(P);459 460 initializeAnalysisImpl(P);461 462#ifdef EXPENSIVE_CHECKS463 uint64_t RefHash = P->structuralHash(CG.getModule());464#endif465 466 // Actually run this pass on the current SCC.467 bool LocalChanged =468 RunPassOnSCC(P, CurSCC, CG, CallGraphUpToDate, DevirtualizedCall);469 470 Changed |= LocalChanged;471 472#ifdef EXPENSIVE_CHECKS473 if (!LocalChanged && (RefHash != P->structuralHash(CG.getModule()))) {474 llvm::errs() << "Pass modifies its input and doesn't report it: "475 << P->getPassName() << "\n";476 llvm_unreachable("Pass modifies its input and doesn't report it");477 }478#endif479 if (LocalChanged)480 dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");481 dumpPreservedSet(P);482 483 verifyPreservedAnalysis(P);484 if (LocalChanged)485 removeNotPreservedAnalysis(P);486 recordAvailableAnalysis(P);487 removeDeadPasses(P, "", ON_CG_MSG);488 }489 490 // If the callgraph was left out of date (because the last pass run was a491 // functionpass), refresh it before we move on to the next SCC.492 if (!CallGraphUpToDate)493 DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);494 return Changed;495}496 497/// Execute all of the passes scheduled for execution. Keep track of498/// whether any of the passes modifies the module, and if so, return true.499bool CGPassManager::runOnModule(Module &M) {500 CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();501 bool Changed = doInitialization(CG);502 503 // Walk the callgraph in bottom-up SCC order.504 scc_iterator<CallGraph*> CGI = scc_begin(&CG);505 506 CallGraphSCC CurSCC(CG, &CGI);507 while (!CGI.isAtEnd()) {508 // Copy the current SCC and increment past it so that the pass can hack509 // on the SCC if it wants to without invalidating our iterator.510 const std::vector<CallGraphNode *> &NodeVec = *CGI;511 CurSCC.initialize(NodeVec);512 ++CGI;513 514 // At the top level, we run all the passes in this pass manager on the515 // functions in this SCC. However, we support iterative compilation in the516 // case where a function pass devirtualizes a call to a function. For517 // example, it is very common for a function pass (often GVN or instcombine)518 // to eliminate the addressing that feeds into a call. With that improved519 // information, we would like the call to be an inline candidate, infer520 // mod-ref information etc.521 //522 // Because of this, we allow iteration up to a specified iteration count.523 // This only happens in the case of a devirtualized call, so we only burn524 // compile time in the case that we're making progress. We also have a hard525 // iteration count limit in case there is crazy code.526 unsigned Iteration = 0;527 bool DevirtualizedCall = false;528 do {529 LLVM_DEBUG(if (Iteration) dbgs()530 << " SCCPASSMGR: Re-visiting SCC, iteration #" << Iteration531 << '\n');532 DevirtualizedCall = false;533 Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);534 } while (Iteration++ < MaxDevirtIterations && DevirtualizedCall);535 536 if (DevirtualizedCall)537 LLVM_DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after "538 << Iteration539 << " times, due to -max-devirt-iterations\n");540 541 MaxSCCIterations.updateMax(Iteration);542 }543 Changed |= doFinalization(CG);544 return Changed;545}546 547/// Initialize CG548bool CGPassManager::doInitialization(CallGraph &CG) {549 bool Changed = false;550 for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {551 if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {552 assert(PM->getPassManagerType() == PMT_FunctionPassManager &&553 "Invalid CGPassManager member");554 Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule());555 } else {556 Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG);557 }558 }559 return Changed;560}561 562/// Finalize CG563bool CGPassManager::doFinalization(CallGraph &CG) {564 bool Changed = false;565 for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {566 if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {567 assert(PM->getPassManagerType() == PMT_FunctionPassManager &&568 "Invalid CGPassManager member");569 Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule());570 } else {571 Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG);572 }573 }574 return Changed;575}576 577//===----------------------------------------------------------------------===//578// CallGraphSCC Implementation579//===----------------------------------------------------------------------===//580 581/// This informs the SCC and the pass manager that the specified582/// Old node has been deleted, and New is to be used in its place.583void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) {584 assert(Old != New && "Should not replace node with self");585 for (unsigned i = 0; ; ++i) {586 assert(i != Nodes.size() && "Node not in SCC");587 if (Nodes[i] != Old) continue;588 if (New)589 Nodes[i] = New;590 else591 Nodes.erase(Nodes.begin() + i);592 break;593 }594 595 // Update the active scc_iterator so that it doesn't contain dangling596 // pointers to the old CallGraphNode.597 scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;598 CGI->ReplaceNode(Old, New);599}600 601void CallGraphSCC::DeleteNode(CallGraphNode *Old) {602 ReplaceNode(Old, /*New=*/nullptr);603}604 605//===----------------------------------------------------------------------===//606// CallGraphSCCPass Implementation607//===----------------------------------------------------------------------===//608 609/// Assign pass manager to manage this pass.610void CallGraphSCCPass::assignPassManager(PMStack &PMS,611 PassManagerType PreferredType) {612 // Find CGPassManager613 while (!PMS.empty() &&614 PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)615 PMS.pop();616 617 assert(!PMS.empty() && "Unable to handle Call Graph Pass");618 CGPassManager *CGP;619 620 if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager)621 CGP = (CGPassManager*)PMS.top();622 else {623 // Create new Call Graph SCC Pass Manager if it does not exist.624 assert(!PMS.empty() && "Unable to create Call Graph Pass Manager");625 PMDataManager *PMD = PMS.top();626 627 // [1] Create new Call Graph Pass Manager628 CGP = new CGPassManager();629 630 // [2] Set up new manager's top level manager631 PMTopLevelManager *TPM = PMD->getTopLevelManager();632 TPM->addIndirectPassManager(CGP);633 634 // [3] Assign manager to manage this new manager. This may create635 // and push new managers into PMS636 Pass *P = CGP;637 TPM->schedulePass(P);638 639 // [4] Push new manager into PMS640 PMS.push(CGP);641 }642 643 CGP->add(this);644}645 646/// For this class, we declare that we require and preserve the call graph.647/// If the derived class implements this method, it should648/// always explicitly call the implementation here.649void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {650 AU.addRequired<CallGraphWrapperPass>();651 AU.addPreserved<CallGraphWrapperPass>();652}653 654//===----------------------------------------------------------------------===//655// PrintCallGraphPass Implementation656//===----------------------------------------------------------------------===//657 658namespace {659 660 /// PrintCallGraphPass - Print a Module corresponding to a call graph.661 ///662 class PrintCallGraphPass : public CallGraphSCCPass {663 std::string Banner;664 raw_ostream &OS; // raw_ostream to print on.665 666 public:667 static char ID;668 669 PrintCallGraphPass(const std::string &B, raw_ostream &OS)670 : CallGraphSCCPass(ID), Banner(B), OS(OS) {}671 672 void getAnalysisUsage(AnalysisUsage &AU) const override {673 AU.setPreservesAll();674 }675 676 bool runOnSCC(CallGraphSCC &SCC) override {677 bool BannerPrinted = false;678 auto PrintBannerOnce = [&]() {679 if (BannerPrinted)680 return;681 OS << Banner;682 BannerPrinted = true;683 };684 685 bool NeedModule = llvm::forcePrintModuleIR();686 if (isFunctionInPrintList("*") && NeedModule) {687 PrintBannerOnce();688 OS << "\n";689 SCC.getCallGraph().getModule().print(OS, nullptr);690 return false;691 }692 bool FoundFunction = false;693 for (CallGraphNode *CGN : SCC) {694 if (Function *F = CGN->getFunction()) {695 if (!F->isDeclaration() && isFunctionInPrintList(F->getName())) {696 FoundFunction = true;697 if (!NeedModule) {698 PrintBannerOnce();699 F->print(OS);700 }701 }702 } else if (isFunctionInPrintList("*")) {703 PrintBannerOnce();704 OS << "\nPrinting <null> Function\n";705 }706 }707 if (NeedModule && FoundFunction) {708 PrintBannerOnce();709 OS << "\n";710 SCC.getCallGraph().getModule().print(OS, nullptr);711 }712 return false;713 }714 715 StringRef getPassName() const override { return "Print CallGraph IR"; }716 };717 718} // end anonymous namespace.719 720char PrintCallGraphPass::ID = 0;721 722Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &OS,723 const std::string &Banner) const {724 return new PrintCallGraphPass(Banner, OS);725}726 727char DummyCGSCCPass::ID = 0;728 729INITIALIZE_PASS(DummyCGSCCPass, "DummyCGSCCPass", "DummyCGSCCPass", false,730 false)731