xref: /llvm-project/llvm/unittests/IR/LegacyPassManagerTest.cpp (revision bec77ece14890d2aa40c76eedc6a7a406d84f1fc)
1 //===- llvm/unittest/IR/LegacyPassManager.cpp - Legacy PassManager tests --===//
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-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This unit test exercises the legacy pass manager infrastructure. We use the
10 // old names as well to ensure that the source-level compatibility is preserved
11 // where possible.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/IR/LegacyPassManager.h"
16 #include "llvm/Analysis/CallGraphSCCPass.h"
17 #include "llvm/Analysis/LoopInfo.h"
18 #include "llvm/Analysis/LoopPass.h"
19 #include "llvm/AsmParser/Parser.h"
20 #include "llvm/IR/AbstractCallSite.h"
21 #include "llvm/IR/BasicBlock.h"
22 #include "llvm/IR/CallingConv.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/DerivedTypes.h"
25 #include "llvm/IR/Function.h"
26 #include "llvm/IR/GlobalVariable.h"
27 #include "llvm/IR/Instructions.h"
28 #include "llvm/IR/LLVMContext.h"
29 #include "llvm/IR/Module.h"
30 #include "llvm/IR/OptBisect.h"
31 #include "llvm/InitializePasses.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/SourceMgr.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include "llvm/Transforms/Utils/CallGraphUpdater.h"
36 #include "gtest/gtest.h"
37 
38 using namespace llvm;
39 
40 namespace llvm {
41   void initializeModuleNDMPass(PassRegistry&);
42   void initializeFPassPass(PassRegistry&);
43   void initializeCGPassPass(PassRegistry&);
44   void initializeLPassPass(PassRegistry&);
45 
46   namespace {
47     // ND = no deps
48     // NM = no modifications
49     struct ModuleNDNM: public ModulePass {
50     public:
51       static char run;
52       static char ID;
53       ModuleNDNM() : ModulePass(ID) { }
54       bool runOnModule(Module &M) override {
55         run++;
56         return false;
57       }
58       void getAnalysisUsage(AnalysisUsage &AU) const override {
59         AU.setPreservesAll();
60       }
61     };
62     char ModuleNDNM::ID=0;
63     char ModuleNDNM::run=0;
64 
65     struct ModuleNDM : public ModulePass {
66     public:
67       static char run;
68       static char ID;
69       ModuleNDM() : ModulePass(ID) {}
70       bool runOnModule(Module &M) override {
71         run++;
72         return true;
73       }
74     };
75     char ModuleNDM::ID=0;
76     char ModuleNDM::run=0;
77 
78     struct ModuleNDM2 : public ModulePass {
79     public:
80       static char run;
81       static char ID;
82       ModuleNDM2() : ModulePass(ID) {}
83       bool runOnModule(Module &M) override {
84         run++;
85         return true;
86       }
87     };
88     char ModuleNDM2::ID=0;
89     char ModuleNDM2::run=0;
90 
91     struct ModuleDNM : public ModulePass {
92     public:
93       static char run;
94       static char ID;
95       ModuleDNM() : ModulePass(ID) {
96         initializeModuleNDMPass(*PassRegistry::getPassRegistry());
97       }
98       bool runOnModule(Module &M) override {
99         run++;
100         return false;
101       }
102       void getAnalysisUsage(AnalysisUsage &AU) const override {
103         AU.addRequired<ModuleNDM>();
104         AU.setPreservesAll();
105       }
106     };
107     char ModuleDNM::ID=0;
108     char ModuleDNM::run=0;
109 
110     template<typename P>
111     struct PassTestBase : public P {
112     protected:
113       static int runc;
114       static bool initialized;
115       static bool finalized;
116       int allocated;
117       void run() {
118         EXPECT_TRUE(initialized);
119         EXPECT_FALSE(finalized);
120         EXPECT_EQ(0, allocated);
121         allocated++;
122         runc++;
123       }
124     public:
125       static char ID;
126       static void finishedOK(int run) {
127         EXPECT_GT(runc, 0);
128         EXPECT_TRUE(initialized);
129         EXPECT_TRUE(finalized);
130         EXPECT_EQ(run, runc);
131       }
132       PassTestBase() : P(ID), allocated(0) {
133         initialized = false;
134         finalized = false;
135         runc = 0;
136       }
137 
138       void releaseMemory() override {
139         EXPECT_GT(runc, 0);
140         EXPECT_GT(allocated, 0);
141         allocated--;
142       }
143     };
144     template<typename P> char PassTestBase<P>::ID;
145     template<typename P> int PassTestBase<P>::runc;
146     template<typename P> bool PassTestBase<P>::initialized;
147     template<typename P> bool PassTestBase<P>::finalized;
148 
149     template<typename T, typename P>
150     struct PassTest : public PassTestBase<P> {
151     public:
152 #ifndef _MSC_VER // MSVC complains that Pass is not base class.
153       using llvm::Pass::doInitialization;
154       using llvm::Pass::doFinalization;
155 #endif
156       bool doInitialization(T &t) override {
157         EXPECT_FALSE(PassTestBase<P>::initialized);
158         PassTestBase<P>::initialized = true;
159         return false;
160       }
161       bool doFinalization(T &t) override {
162         EXPECT_FALSE(PassTestBase<P>::finalized);
163         PassTestBase<P>::finalized = true;
164         EXPECT_EQ(0, PassTestBase<P>::allocated);
165         return false;
166       }
167     };
168 
169     struct CGPass : public PassTest<CallGraph, CallGraphSCCPass> {
170     public:
171       CGPass() {
172         initializeCGPassPass(*PassRegistry::getPassRegistry());
173       }
174       bool runOnSCC(CallGraphSCC &SCMM) override {
175         run();
176         return false;
177       }
178     };
179 
180     struct FPass : public PassTest<Module, FunctionPass> {
181     public:
182       bool runOnFunction(Function &F) override {
183         // FIXME: PR4112
184         // EXPECT_TRUE(getAnalysisIfAvailable<DataLayout>());
185         run();
186         return false;
187       }
188     };
189 
190     struct LPass : public PassTestBase<LoopPass> {
191     private:
192       static int initcount;
193       static int fincount;
194     public:
195       LPass() {
196         initializeLPassPass(*PassRegistry::getPassRegistry());
197         initcount = 0; fincount=0;
198         EXPECT_FALSE(initialized);
199       }
200       static void finishedOK(int run, int finalized) {
201         PassTestBase<LoopPass>::finishedOK(run);
202         EXPECT_EQ(run, initcount);
203         EXPECT_EQ(finalized, fincount);
204       }
205       using llvm::Pass::doInitialization;
206       using llvm::Pass::doFinalization;
207       bool doInitialization(Loop* L, LPPassManager &LPM) override {
208         initialized = true;
209         initcount++;
210         return false;
211       }
212       bool runOnLoop(Loop *L, LPPassManager &LPM) override {
213         run();
214         return false;
215       }
216       bool doFinalization() override {
217         fincount++;
218         finalized = true;
219         return false;
220       }
221     };
222     int LPass::initcount=0;
223     int LPass::fincount=0;
224 
225     struct OnTheFlyTest: public ModulePass {
226     public:
227       static char ID;
228       OnTheFlyTest() : ModulePass(ID) {
229         initializeFPassPass(*PassRegistry::getPassRegistry());
230       }
231       bool runOnModule(Module &M) override {
232         for (Module::iterator I=M.begin(),E=M.end(); I != E; ++I) {
233           Function &F = *I;
234           {
235             SCOPED_TRACE("Running on the fly function pass");
236             getAnalysis<FPass>(F);
237           }
238         }
239         return false;
240       }
241       void getAnalysisUsage(AnalysisUsage &AU) const override {
242         AU.addRequired<FPass>();
243       }
244     };
245     char OnTheFlyTest::ID=0;
246 
247     TEST(PassManager, RunOnce) {
248       LLVMContext Context;
249       Module M("test-once", Context);
250       struct ModuleNDNM *mNDNM = new ModuleNDNM();
251       struct ModuleDNM *mDNM = new ModuleDNM();
252       struct ModuleNDM *mNDM = new ModuleNDM();
253       struct ModuleNDM2 *mNDM2 = new ModuleNDM2();
254 
255       mNDM->run = mNDNM->run = mDNM->run = mNDM2->run = 0;
256 
257       legacy::PassManager Passes;
258       Passes.add(mNDM2);
259       Passes.add(mNDM);
260       Passes.add(mNDNM);
261       Passes.add(mDNM);
262 
263       Passes.run(M);
264       // each pass must be run exactly once, since nothing invalidates them
265       EXPECT_EQ(1, mNDM->run);
266       EXPECT_EQ(1, mNDNM->run);
267       EXPECT_EQ(1, mDNM->run);
268       EXPECT_EQ(1, mNDM2->run);
269     }
270 
271     TEST(PassManager, ReRun) {
272       LLVMContext Context;
273       Module M("test-rerun", Context);
274       struct ModuleNDNM *mNDNM = new ModuleNDNM();
275       struct ModuleDNM *mDNM = new ModuleDNM();
276       struct ModuleNDM *mNDM = new ModuleNDM();
277       struct ModuleNDM2 *mNDM2 = new ModuleNDM2();
278 
279       mNDM->run = mNDNM->run = mDNM->run = mNDM2->run = 0;
280 
281       legacy::PassManager Passes;
282       Passes.add(mNDM);
283       Passes.add(mNDNM);
284       Passes.add(mNDM2);// invalidates mNDM needed by mDNM
285       Passes.add(mDNM);
286 
287       Passes.run(M);
288       // Some passes must be rerun because a pass that modified the
289       // module/function was run in between
290       EXPECT_EQ(2, mNDM->run);
291       EXPECT_EQ(1, mNDNM->run);
292       EXPECT_EQ(1, mNDM2->run);
293       EXPECT_EQ(1, mDNM->run);
294     }
295 
296     Module *makeLLVMModule(LLVMContext &Context);
297 
298     template<typename T>
299     void MemoryTestHelper(int run) {
300       LLVMContext Context;
301       std::unique_ptr<Module> M(makeLLVMModule(Context));
302       T *P = new T();
303       legacy::PassManager Passes;
304       Passes.add(P);
305       Passes.run(*M);
306       T::finishedOK(run);
307     }
308 
309     template<typename T>
310     void MemoryTestHelper(int run, int N) {
311       LLVMContext Context;
312       Module *M = makeLLVMModule(Context);
313       T *P = new T();
314       legacy::PassManager Passes;
315       Passes.add(P);
316       Passes.run(*M);
317       T::finishedOK(run, N);
318       delete M;
319     }
320 
321     TEST(PassManager, Memory) {
322       // SCC#1: test1->test2->test3->test1
323       // SCC#2: test4
324       // SCC#3: indirect call node
325       {
326         SCOPED_TRACE("Callgraph pass");
327         MemoryTestHelper<CGPass>(3);
328       }
329 
330       {
331         SCOPED_TRACE("Function pass");
332         MemoryTestHelper<FPass>(4);// 4 functions
333       }
334 
335       {
336         SCOPED_TRACE("Loop pass");
337         MemoryTestHelper<LPass>(2, 1); //2 loops, 1 function
338       }
339 
340     }
341 
342     TEST(PassManager, MemoryOnTheFly) {
343       LLVMContext Context;
344       Module *M = makeLLVMModule(Context);
345       {
346         SCOPED_TRACE("Running OnTheFlyTest");
347         struct OnTheFlyTest *O = new OnTheFlyTest();
348         legacy::PassManager Passes;
349         Passes.add(O);
350         Passes.run(*M);
351 
352         FPass::finishedOK(4);
353       }
354       delete M;
355     }
356 
357     // Skips or runs optional passes.
358     struct CustomOptPassGate : public OptPassGate {
359       bool Skip;
360       CustomOptPassGate(bool Skip) : Skip(Skip) { }
361       bool shouldRunPass(const Pass *P, StringRef IRDescription) override {
362         if (P->getPassKind() == PT_Module)
363           return !Skip;
364         return OptPassGate::shouldRunPass(P, IRDescription);
365       }
366       bool isEnabled() const override { return true; }
367     };
368 
369     // Optional module pass.
370     struct ModuleOpt: public ModulePass {
371       char run = 0;
372       static char ID;
373       ModuleOpt() : ModulePass(ID) { }
374       bool runOnModule(Module &M) override {
375         if (!skipModule(M))
376           run++;
377         return false;
378       }
379     };
380     char ModuleOpt::ID=0;
381 
382     TEST(PassManager, CustomOptPassGate) {
383       LLVMContext Context0;
384       LLVMContext Context1;
385       LLVMContext Context2;
386       CustomOptPassGate SkipOptionalPasses(true);
387       CustomOptPassGate RunOptionalPasses(false);
388 
389       Module M0("custom-opt-bisect", Context0);
390       Module M1("custom-opt-bisect", Context1);
391       Module M2("custom-opt-bisect2", Context2);
392       struct ModuleOpt *mOpt0 = new ModuleOpt();
393       struct ModuleOpt *mOpt1 = new ModuleOpt();
394       struct ModuleOpt *mOpt2 = new ModuleOpt();
395 
396       mOpt0->run = mOpt1->run = mOpt2->run = 0;
397 
398       legacy::PassManager Passes0;
399       legacy::PassManager Passes1;
400       legacy::PassManager Passes2;
401 
402       Passes0.add(mOpt0);
403       Passes1.add(mOpt1);
404       Passes2.add(mOpt2);
405 
406       Context1.setOptPassGate(SkipOptionalPasses);
407       Context2.setOptPassGate(RunOptionalPasses);
408 
409       Passes0.run(M0);
410       Passes1.run(M1);
411       Passes2.run(M2);
412 
413       // By default optional passes are run.
414       EXPECT_EQ(1, mOpt0->run);
415 
416       // The first context skips optional passes.
417       EXPECT_EQ(0, mOpt1->run);
418 
419       // The second context runs optional passes.
420       EXPECT_EQ(1, mOpt2->run);
421     }
422 
423     Module *makeLLVMModule(LLVMContext &Context) {
424       // Module Construction
425       Module *mod = new Module("test-mem", Context);
426       mod->setDataLayout("e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
427                          "i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-"
428                          "a:0:64-s:64:64-f80:128:128");
429       mod->setTargetTriple("x86_64-unknown-linux-gnu");
430 
431       // Type Definitions
432       std::vector<Type*>FuncTy_0_args;
433       FunctionType *FuncTy_0 = FunctionType::get(
434           /*Result=*/IntegerType::get(Context, 32),
435           /*Params=*/FuncTy_0_args,
436           /*isVarArg=*/false);
437 
438       std::vector<Type*>FuncTy_2_args;
439       FuncTy_2_args.push_back(IntegerType::get(Context, 1));
440       FunctionType *FuncTy_2 = FunctionType::get(
441           /*Result=*/Type::getVoidTy(Context),
442           /*Params=*/FuncTy_2_args,
443           /*isVarArg=*/false);
444 
445       // Function Declarations
446 
447       Function* func_test1 = Function::Create(
448         /*Type=*/FuncTy_0,
449         /*Linkage=*/GlobalValue::ExternalLinkage,
450         /*Name=*/"test1", mod);
451       func_test1->setCallingConv(CallingConv::C);
452       AttributeList func_test1_PAL;
453       func_test1->setAttributes(func_test1_PAL);
454 
455       Function* func_test2 = Function::Create(
456         /*Type=*/FuncTy_0,
457         /*Linkage=*/GlobalValue::ExternalLinkage,
458         /*Name=*/"test2", mod);
459       func_test2->setCallingConv(CallingConv::C);
460       AttributeList func_test2_PAL;
461       func_test2->setAttributes(func_test2_PAL);
462 
463       Function* func_test3 = Function::Create(
464         /*Type=*/FuncTy_0,
465         /*Linkage=*/GlobalValue::InternalLinkage,
466         /*Name=*/"test3", mod);
467       func_test3->setCallingConv(CallingConv::C);
468       AttributeList func_test3_PAL;
469       func_test3->setAttributes(func_test3_PAL);
470 
471       Function* func_test4 = Function::Create(
472         /*Type=*/FuncTy_2,
473         /*Linkage=*/GlobalValue::ExternalLinkage,
474         /*Name=*/"test4", mod);
475       func_test4->setCallingConv(CallingConv::C);
476       AttributeList func_test4_PAL;
477       func_test4->setAttributes(func_test4_PAL);
478 
479       // Global Variable Declarations
480 
481 
482       // Constant Definitions
483 
484       // Global Variable Definitions
485 
486       // Function Definitions
487 
488       // Function: test1 (func_test1)
489       {
490 
491         BasicBlock *label_entry =
492             BasicBlock::Create(Context, "entry", func_test1, nullptr);
493 
494         // Block entry (label_entry)
495         CallInst* int32_3 = CallInst::Create(func_test2, "", label_entry);
496         int32_3->setCallingConv(CallingConv::C);
497         int32_3->setTailCall(false);
498         AttributeList int32_3_PAL;
499         int32_3->setAttributes(int32_3_PAL);
500 
501         ReturnInst::Create(Context, int32_3, label_entry);
502       }
503 
504       // Function: test2 (func_test2)
505       {
506 
507         BasicBlock *label_entry_5 =
508             BasicBlock::Create(Context, "entry", func_test2, nullptr);
509 
510         // Block entry (label_entry_5)
511         CallInst* int32_6 = CallInst::Create(func_test3, "", label_entry_5);
512         int32_6->setCallingConv(CallingConv::C);
513         int32_6->setTailCall(false);
514         AttributeList int32_6_PAL;
515         int32_6->setAttributes(int32_6_PAL);
516 
517         ReturnInst::Create(Context, int32_6, label_entry_5);
518       }
519 
520       // Function: test3 (func_test3)
521       {
522 
523         BasicBlock *label_entry_8 =
524             BasicBlock::Create(Context, "entry", func_test3, nullptr);
525 
526         // Block entry (label_entry_8)
527         CallInst* int32_9 = CallInst::Create(func_test1, "", label_entry_8);
528         int32_9->setCallingConv(CallingConv::C);
529         int32_9->setTailCall(false);
530         AttributeList int32_9_PAL;
531         int32_9->setAttributes(int32_9_PAL);
532 
533         ReturnInst::Create(Context, int32_9, label_entry_8);
534       }
535 
536       // Function: test4 (func_test4)
537       {
538         Function::arg_iterator args = func_test4->arg_begin();
539         Value *int1_f = &*args++;
540         int1_f->setName("f");
541 
542         BasicBlock *label_entry_11 =
543             BasicBlock::Create(Context, "entry", func_test4, nullptr);
544         BasicBlock *label_bb =
545             BasicBlock::Create(Context, "bb", func_test4, nullptr);
546         BasicBlock *label_bb1 =
547             BasicBlock::Create(Context, "bb1", func_test4, nullptr);
548         BasicBlock *label_return =
549             BasicBlock::Create(Context, "return", func_test4, nullptr);
550 
551         // Block entry (label_entry_11)
552         auto *AI = new AllocaInst(func_test3->getType(), 0, "func3ptr",
553                                   label_entry_11);
554         new StoreInst(func_test3, AI, label_entry_11);
555         BranchInst::Create(label_bb, label_entry_11);
556 
557         // Block bb (label_bb)
558         BranchInst::Create(label_bb, label_bb1, int1_f, label_bb);
559 
560         // Block bb1 (label_bb1)
561         BranchInst::Create(label_bb1, label_return, int1_f, label_bb1);
562 
563         // Block return (label_return)
564         ReturnInst::Create(Context, label_return);
565       }
566       return mod;
567     }
568 
569     /// Split a simple function which contains only a call and a return into two
570     /// such that the first calls the second and the second whoever was called
571     /// initially.
572     Function *splitSimpleFunction(Function &F) {
573       LLVMContext &Context = F.getContext();
574       Function *SF = Function::Create(F.getFunctionType(), F.getLinkage(),
575                                       F.getName() + "b", F.getParent());
576       F.setName(F.getName() + "a");
577       BasicBlock *Entry = BasicBlock::Create(Context, "entry", SF, nullptr);
578       CallInst &CI = cast<CallInst>(F.getEntryBlock().front());
579       CI.clone()->insertBefore(ReturnInst::Create(Context, Entry));
580       CI.setCalledFunction(SF);
581       return SF;
582     }
583 
584     struct CGModifierPass : public CGPass {
585       unsigned NumSCCs = 0;
586       unsigned NumFns = 0;
587       unsigned NumFnDecls = 0;
588       unsigned SetupWorked = 0;
589       unsigned NumExtCalledBefore = 0;
590       unsigned NumExtCalledAfter = 0;
591 
592       CallGraphUpdater CGU;
593 
594       bool runOnSCC(CallGraphSCC &SCMM) override {
595         ++NumSCCs;
596         for (CallGraphNode *N : SCMM) {
597           if (N->getFunction()){
598             ++NumFns;
599             NumFnDecls += N->getFunction()->isDeclaration();
600           }
601         }
602         CGPass::run();
603 
604         CallGraph &CG = const_cast<CallGraph &>(SCMM.getCallGraph());
605         CallGraphNode *ExtCallingNode = CG.getExternalCallingNode();
606         NumExtCalledBefore = ExtCallingNode->size();
607 
608         if (SCMM.size() <= 1)
609           return false;
610 
611         CallGraphNode *N = *(SCMM.begin());
612         Function *F = N->getFunction();
613         Module *M = F->getParent();
614         Function *Test1F = M->getFunction("test1");
615         Function *Test2aF = M->getFunction("test2a");
616         Function *Test2bF = M->getFunction("test2b");
617         Function *Test3F = M->getFunction("test3");
618 
619         auto InSCC = [&](Function *Fn) {
620           return llvm::any_of(SCMM, [Fn](CallGraphNode *CGN) {
621             return CGN->getFunction() == Fn;
622           });
623         };
624 
625         if (!Test1F || !Test2aF || !Test2bF || !Test3F || !InSCC(Test1F) ||
626             !InSCC(Test2aF) || !InSCC(Test2bF) || !InSCC(Test3F))
627           return false;
628 
629         CallInst *CI = dyn_cast<CallInst>(&Test1F->getEntryBlock().front());
630         if (!CI || CI->getCalledFunction() != Test2aF)
631           return false;
632 
633         SetupWorked += 1;
634 
635         // Create a replica of test3 and just move the blocks there.
636         Function *Test3FRepl = Function::Create(
637             /*Type=*/Test3F->getFunctionType(),
638             /*Linkage=*/GlobalValue::InternalLinkage,
639             /*Name=*/"test3repl", Test3F->getParent());
640         while (!Test3F->empty()) {
641           BasicBlock &BB = Test3F->front();
642           BB.removeFromParent();
643           BB.insertInto(Test3FRepl);
644         }
645 
646         CGU.initialize(CG, SCMM);
647 
648         // Replace test3 with the replica. This is legal as it is actually
649         // internal and the "capturing use" is not really capturing anything.
650         CGU.replaceFunctionWith(*Test3F, *Test3FRepl);
651         Test3F->replaceAllUsesWith(Test3FRepl);
652 
653         // Rewrite the call in test1 to point to the replica of 3 not test2.
654         CI->setCalledFunction(Test3FRepl);
655 
656         // Delete test2a and test2b and reanalyze 1 as we changed calls inside.
657         CGU.removeFunction(*Test2aF);
658         CGU.removeFunction(*Test2bF);
659         CGU.reanalyzeFunction(*Test1F);
660 
661         return true;
662       }
663 
664       bool doFinalization(CallGraph &CG) override {
665         CGU.finalize();
666         // We removed test2 and replaced the internal test3.
667         NumExtCalledAfter = CG.getExternalCallingNode()->size();
668         return true;
669       }
670     };
671 
672     TEST(PassManager, CallGraphUpdater0) {
673       // SCC#1: test1->test2a->test2b->test3->test1
674       // SCC#2: test4
675       // SCC#3: test3 (the empty function declaration as we replaced it with
676       //               test3repl when we visited SCC#1)
677       // SCC#4: test2a->test2b (the empty function declarations as we deleted
678       //                        these functions when we visited SCC#1)
679       // SCC#5: indirect call node
680 
681       LLVMContext Context;
682       std::unique_ptr<Module> M(makeLLVMModule(Context));
683       ASSERT_EQ(M->getFunctionList().size(), 4U);
684       Function *F = M->getFunction("test2");
685       Function *SF = splitSimpleFunction(*F);
686       CallInst::Create(F, "", &*SF->getEntryBlock().getFirstInsertionPt());
687       ASSERT_EQ(M->getFunctionList().size(), 5U);
688       CGModifierPass *P = new CGModifierPass();
689       legacy::PassManager Passes;
690       Passes.add(P);
691       Passes.run(*M);
692       ASSERT_EQ(P->SetupWorked, 1U);
693       ASSERT_EQ(P->NumSCCs, 4U);
694       ASSERT_EQ(P->NumFns, 6U);
695       ASSERT_EQ(P->NumFnDecls, 1U);
696       ASSERT_EQ(M->getFunctionList().size(), 3U);
697       ASSERT_EQ(P->NumExtCalledBefore, /* test1, 2a, 2b, 3, 4 */ 5U);
698       ASSERT_EQ(P->NumExtCalledAfter, /* test1, 3repl, 4 */ 3U);
699     }
700 
701     // Test for call graph SCC pass that replaces all callback call instructions
702     // with clones and updates CallGraph by calling CallGraph::replaceCallEdge()
703     // method. Test is expected to complete successfully after running pass on
704     // all SCCs in the test module.
705     struct CallbackCallsModifierPass : public CGPass {
706       bool runOnSCC(CallGraphSCC &SCC) override {
707         CGPass::run();
708 
709         CallGraph &CG = const_cast<CallGraph &>(SCC.getCallGraph());
710 
711         bool Changed = false;
712         for (CallGraphNode *CGN : SCC) {
713           Function *F = CGN->getFunction();
714           if (!F || F->isDeclaration())
715             continue;
716 
717           SmallVector<CallBase *, 4u> Calls;
718           for (Use &U : F->uses()) {
719             AbstractCallSite ACS(&U);
720             if (!ACS || !ACS.isCallbackCall() || !ACS.isCallee(&U))
721               continue;
722             Calls.push_back(cast<CallBase>(ACS.getInstruction()));
723           }
724           if (Calls.empty())
725             continue;
726 
727           for (CallBase *OldCB : Calls) {
728             CallGraphNode *CallerCGN = CG[OldCB->getParent()->getParent()];
729             assert(any_of(*CallerCGN,
730                           [CGN](const CallGraphNode::CallRecord &CallRecord) {
731                             return CallRecord.second == CGN;
732                           }) &&
733                    "function is not a callee");
734 
735             CallBase *NewCB = cast<CallBase>(OldCB->clone());
736 
737             NewCB->insertBefore(OldCB);
738             NewCB->takeName(OldCB);
739 
740             CallerCGN->replaceCallEdge(*OldCB, *NewCB, CG[F]);
741 
742             OldCB->replaceAllUsesWith(NewCB);
743             OldCB->eraseFromParent();
744           }
745           Changed = true;
746         }
747         return Changed;
748       }
749     };
750 
751     TEST(PassManager, CallbackCallsModifier0) {
752       LLVMContext Context;
753 
754       const char *IR = "define void @foo() {\n"
755                        "  call void @broker(void (i8*)* @callback0, i8* null)\n"
756                        "  call void @broker(void (i8*)* @callback1, i8* null)\n"
757                        "  ret void\n"
758                        "}\n"
759                        "\n"
760                        "declare !callback !0 void @broker(void (i8*)*, i8*)\n"
761                        "\n"
762                        "define internal void @callback0(i8* %arg) {\n"
763                        "  ret void\n"
764                        "}\n"
765                        "\n"
766                        "define internal void @callback1(i8* %arg) {\n"
767                        "  ret void\n"
768                        "}\n"
769                        "\n"
770                        "!0 = !{!1}\n"
771                        "!1 = !{i64 0, i64 1, i1 false}";
772 
773       SMDiagnostic Err;
774       std::unique_ptr<Module> M = parseAssemblyString(IR, Err, Context);
775       if (!M)
776         Err.print("LegacyPassManagerTest", errs());
777 
778       CallbackCallsModifierPass *P = new CallbackCallsModifierPass();
779       legacy::PassManager Passes;
780       Passes.add(P);
781       Passes.run(*M);
782     }
783   }
784 }
785 
786 INITIALIZE_PASS(ModuleNDM, "mndm", "mndm", false, false)
787 INITIALIZE_PASS_BEGIN(CGPass, "cgp","cgp", false, false)
788 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
789 INITIALIZE_PASS_END(CGPass, "cgp","cgp", false, false)
790 INITIALIZE_PASS(FPass, "fp","fp", false, false)
791 INITIALIZE_PASS_BEGIN(LPass, "lp","lp", false, false)
792 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
793 INITIALIZE_PASS_END(LPass, "lp","lp", false, false)
794