xref: /llvm-project/llvm/unittests/IR/LegacyPassManagerTest.cpp (revision a494ae43bef09c8d0f6a6a98e92f3a89758247d5)
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/CallGraph.h"
17 #include "llvm/Analysis/CallGraphSCCPass.h"
18 #include "llvm/Analysis/LoopInfo.h"
19 #include "llvm/Analysis/LoopPass.h"
20 #include "llvm/AsmParser/Parser.h"
21 #include "llvm/IR/AbstractCallSite.h"
22 #include "llvm/IR/BasicBlock.h"
23 #include "llvm/IR/CallingConv.h"
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/IR/DerivedTypes.h"
26 #include "llvm/IR/Function.h"
27 #include "llvm/IR/GlobalVariable.h"
28 #include "llvm/IR/Instructions.h"
29 #include "llvm/IR/LLVMContext.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/OptBisect.h"
32 #include "llvm/InitializePasses.h"
33 #include "llvm/Support/MathExtras.h"
34 #include "llvm/Support/SourceMgr.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/Transforms/Utils/CallGraphUpdater.h"
37 #include "gtest/gtest.h"
38 
39 using namespace llvm;
40 
41 namespace llvm {
42   void initializeModuleNDMPass(PassRegistry&);
43   void initializeFPassPass(PassRegistry&);
44   void initializeCGPassPass(PassRegistry&);
45   void initializeLPassPass(PassRegistry&);
46 
47   namespace {
48     // ND = no deps
49     // NM = no modifications
50     struct ModuleNDNM: public ModulePass {
51     public:
52       static char run;
53       static char ID;
54       ModuleNDNM() : ModulePass(ID) { }
55       bool runOnModule(Module &M) override {
56         run++;
57         return false;
58       }
59       void getAnalysisUsage(AnalysisUsage &AU) const override {
60         AU.setPreservesAll();
61       }
62     };
63     char ModuleNDNM::ID=0;
64     char ModuleNDNM::run=0;
65 
66     struct ModuleNDM : public ModulePass {
67     public:
68       static char run;
69       static char ID;
70       ModuleNDM() : ModulePass(ID) {}
71       bool runOnModule(Module &M) override {
72         run++;
73         return true;
74       }
75     };
76     char ModuleNDM::ID=0;
77     char ModuleNDM::run=0;
78 
79     struct ModuleNDM2 : public ModulePass {
80     public:
81       static char run;
82       static char ID;
83       ModuleNDM2() : ModulePass(ID) {}
84       bool runOnModule(Module &M) override {
85         run++;
86         return true;
87       }
88     };
89     char ModuleNDM2::ID=0;
90     char ModuleNDM2::run=0;
91 
92     struct ModuleDNM : public ModulePass {
93     public:
94       static char run;
95       static char ID;
96       ModuleDNM() : ModulePass(ID) {
97         initializeModuleNDMPass(*PassRegistry::getPassRegistry());
98       }
99       bool runOnModule(Module &M) override {
100         run++;
101         return false;
102       }
103       void getAnalysisUsage(AnalysisUsage &AU) const override {
104         AU.addRequired<ModuleNDM>();
105         AU.setPreservesAll();
106       }
107     };
108     char ModuleDNM::ID=0;
109     char ModuleDNM::run=0;
110 
111     template<typename P>
112     struct PassTestBase : public P {
113     protected:
114       static int runc;
115       static bool initialized;
116       static bool finalized;
117       int allocated;
118       void run() {
119         EXPECT_TRUE(initialized);
120         EXPECT_FALSE(finalized);
121         EXPECT_EQ(0, allocated);
122         allocated++;
123         runc++;
124       }
125     public:
126       static char ID;
127       static void finishedOK(int run) {
128         EXPECT_GT(runc, 0);
129         EXPECT_TRUE(initialized);
130         EXPECT_TRUE(finalized);
131         EXPECT_EQ(run, runc);
132       }
133       PassTestBase() : P(ID), allocated(0) {
134         initialized = false;
135         finalized = false;
136         runc = 0;
137       }
138 
139       void releaseMemory() override {
140         EXPECT_GT(runc, 0);
141         EXPECT_GT(allocated, 0);
142         allocated--;
143       }
144     };
145     template<typename P> char PassTestBase<P>::ID;
146     template<typename P> int PassTestBase<P>::runc;
147     template<typename P> bool PassTestBase<P>::initialized;
148     template<typename P> bool PassTestBase<P>::finalized;
149 
150     template<typename T, typename P>
151     struct PassTest : public PassTestBase<P> {
152     public:
153 #ifndef _MSC_VER // MSVC complains that Pass is not base class.
154       using llvm::Pass::doInitialization;
155       using llvm::Pass::doFinalization;
156 #endif
157       bool doInitialization(T &t) override {
158         EXPECT_FALSE(PassTestBase<P>::initialized);
159         PassTestBase<P>::initialized = true;
160         return false;
161       }
162       bool doFinalization(T &t) override {
163         EXPECT_FALSE(PassTestBase<P>::finalized);
164         PassTestBase<P>::finalized = true;
165         EXPECT_EQ(0, PassTestBase<P>::allocated);
166         return false;
167       }
168     };
169 
170     struct CGPass : public PassTest<CallGraph, CallGraphSCCPass> {
171     public:
172       CGPass() {
173         initializeCGPassPass(*PassRegistry::getPassRegistry());
174       }
175       bool runOnSCC(CallGraphSCC &SCMM) override {
176         run();
177         return false;
178       }
179     };
180 
181     struct FPass : public PassTest<Module, FunctionPass> {
182     public:
183       bool runOnFunction(Function &F) override {
184         // FIXME: PR4112
185         // EXPECT_TRUE(getAnalysisIfAvailable<DataLayout>());
186         run();
187         return false;
188       }
189     };
190 
191     struct LPass : public PassTestBase<LoopPass> {
192     private:
193       static int initcount;
194       static int fincount;
195     public:
196       LPass() {
197         initializeLPassPass(*PassRegistry::getPassRegistry());
198         initcount = 0; fincount=0;
199         EXPECT_FALSE(initialized);
200       }
201       static void finishedOK(int run, int finalized) {
202         PassTestBase<LoopPass>::finishedOK(run);
203         EXPECT_EQ(run, initcount);
204         EXPECT_EQ(finalized, fincount);
205       }
206       using llvm::Pass::doInitialization;
207       using llvm::Pass::doFinalization;
208       bool doInitialization(Loop* L, LPPassManager &LPM) override {
209         initialized = true;
210         initcount++;
211         return false;
212       }
213       bool runOnLoop(Loop *L, LPPassManager &LPM) override {
214         run();
215         return false;
216       }
217       bool doFinalization() override {
218         fincount++;
219         finalized = true;
220         return false;
221       }
222     };
223     int LPass::initcount=0;
224     int LPass::fincount=0;
225 
226     struct OnTheFlyTest: public ModulePass {
227     public:
228       static char ID;
229       OnTheFlyTest() : ModulePass(ID) {
230         initializeFPassPass(*PassRegistry::getPassRegistry());
231       }
232       bool runOnModule(Module &M) override {
233         for (Module::iterator I=M.begin(),E=M.end(); I != E; ++I) {
234           Function &F = *I;
235           {
236             SCOPED_TRACE("Running on the fly function pass");
237             getAnalysis<FPass>(F);
238           }
239         }
240         return false;
241       }
242       void getAnalysisUsage(AnalysisUsage &AU) const override {
243         AU.addRequired<FPass>();
244       }
245     };
246     char OnTheFlyTest::ID=0;
247 
248     TEST(PassManager, RunOnce) {
249       LLVMContext Context;
250       Module M("test-once", Context);
251       struct ModuleNDNM *mNDNM = new ModuleNDNM();
252       struct ModuleDNM *mDNM = new ModuleDNM();
253       struct ModuleNDM *mNDM = new ModuleNDM();
254       struct ModuleNDM2 *mNDM2 = new ModuleNDM2();
255 
256       mNDM->run = mNDNM->run = mDNM->run = mNDM2->run = 0;
257 
258       legacy::PassManager Passes;
259       Passes.add(mNDM2);
260       Passes.add(mNDM);
261       Passes.add(mNDNM);
262       Passes.add(mDNM);
263 
264       Passes.run(M);
265       // each pass must be run exactly once, since nothing invalidates them
266       EXPECT_EQ(1, mNDM->run);
267       EXPECT_EQ(1, mNDNM->run);
268       EXPECT_EQ(1, mDNM->run);
269       EXPECT_EQ(1, mNDM2->run);
270     }
271 
272     TEST(PassManager, ReRun) {
273       LLVMContext Context;
274       Module M("test-rerun", Context);
275       struct ModuleNDNM *mNDNM = new ModuleNDNM();
276       struct ModuleDNM *mDNM = new ModuleDNM();
277       struct ModuleNDM *mNDM = new ModuleNDM();
278       struct ModuleNDM2 *mNDM2 = new ModuleNDM2();
279 
280       mNDM->run = mNDNM->run = mDNM->run = mNDM2->run = 0;
281 
282       legacy::PassManager Passes;
283       Passes.add(mNDM);
284       Passes.add(mNDNM);
285       Passes.add(mNDM2);// invalidates mNDM needed by mDNM
286       Passes.add(mDNM);
287 
288       Passes.run(M);
289       // Some passes must be rerun because a pass that modified the
290       // module/function was run in between
291       EXPECT_EQ(2, mNDM->run);
292       EXPECT_EQ(1, mNDNM->run);
293       EXPECT_EQ(1, mNDM2->run);
294       EXPECT_EQ(1, mDNM->run);
295     }
296 
297     Module *makeLLVMModule(LLVMContext &Context);
298 
299     template<typename T>
300     void MemoryTestHelper(int run) {
301       LLVMContext Context;
302       std::unique_ptr<Module> M(makeLLVMModule(Context));
303       T *P = new T();
304       legacy::PassManager Passes;
305       Passes.add(P);
306       Passes.run(*M);
307       T::finishedOK(run);
308     }
309 
310     template<typename T>
311     void MemoryTestHelper(int run, int N) {
312       LLVMContext Context;
313       Module *M = makeLLVMModule(Context);
314       T *P = new T();
315       legacy::PassManager Passes;
316       Passes.add(P);
317       Passes.run(*M);
318       T::finishedOK(run, N);
319       delete M;
320     }
321 
322     TEST(PassManager, Memory) {
323       // SCC#1: test1->test2->test3->test1
324       // SCC#2: test4
325       // SCC#3: indirect call node
326       {
327         SCOPED_TRACE("Callgraph pass");
328         MemoryTestHelper<CGPass>(3);
329       }
330 
331       {
332         SCOPED_TRACE("Function pass");
333         MemoryTestHelper<FPass>(4);// 4 functions
334       }
335 
336       {
337         SCOPED_TRACE("Loop pass");
338         MemoryTestHelper<LPass>(2, 1); //2 loops, 1 function
339       }
340 
341     }
342 
343     TEST(PassManager, MemoryOnTheFly) {
344       LLVMContext Context;
345       Module *M = makeLLVMModule(Context);
346       {
347         SCOPED_TRACE("Running OnTheFlyTest");
348         struct OnTheFlyTest *O = new OnTheFlyTest();
349         legacy::PassManager Passes;
350         Passes.add(O);
351         Passes.run(*M);
352 
353         FPass::finishedOK(4);
354       }
355       delete M;
356     }
357 
358     // Skips or runs optional passes.
359     struct CustomOptPassGate : public OptPassGate {
360       bool Skip;
361       CustomOptPassGate(bool Skip) : Skip(Skip) { }
362       bool shouldRunPass(const Pass *P, StringRef IRDescription) override {
363         if (P->getPassKind() == PT_Module)
364           return !Skip;
365         return OptPassGate::shouldRunPass(P, IRDescription);
366       }
367       bool isEnabled() const override { return true; }
368     };
369 
370     // Optional module pass.
371     struct ModuleOpt: public ModulePass {
372       char run = 0;
373       static char ID;
374       ModuleOpt() : ModulePass(ID) { }
375       bool runOnModule(Module &M) override {
376         if (!skipModule(M))
377           run++;
378         return false;
379       }
380     };
381     char ModuleOpt::ID=0;
382 
383     TEST(PassManager, CustomOptPassGate) {
384       LLVMContext Context0;
385       LLVMContext Context1;
386       LLVMContext Context2;
387       CustomOptPassGate SkipOptionalPasses(true);
388       CustomOptPassGate RunOptionalPasses(false);
389 
390       Module M0("custom-opt-bisect", Context0);
391       Module M1("custom-opt-bisect", Context1);
392       Module M2("custom-opt-bisect2", Context2);
393       struct ModuleOpt *mOpt0 = new ModuleOpt();
394       struct ModuleOpt *mOpt1 = new ModuleOpt();
395       struct ModuleOpt *mOpt2 = new ModuleOpt();
396 
397       mOpt0->run = mOpt1->run = mOpt2->run = 0;
398 
399       legacy::PassManager Passes0;
400       legacy::PassManager Passes1;
401       legacy::PassManager Passes2;
402 
403       Passes0.add(mOpt0);
404       Passes1.add(mOpt1);
405       Passes2.add(mOpt2);
406 
407       Context1.setOptPassGate(SkipOptionalPasses);
408       Context2.setOptPassGate(RunOptionalPasses);
409 
410       Passes0.run(M0);
411       Passes1.run(M1);
412       Passes2.run(M2);
413 
414       // By default optional passes are run.
415       EXPECT_EQ(1, mOpt0->run);
416 
417       // The first context skips optional passes.
418       EXPECT_EQ(0, mOpt1->run);
419 
420       // The second context runs optional passes.
421       EXPECT_EQ(1, mOpt2->run);
422     }
423 
424     Module *makeLLVMModule(LLVMContext &Context) {
425       // Module Construction
426       Module *mod = new Module("test-mem", Context);
427       mod->setDataLayout("e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
428                          "i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-"
429                          "a:0:64-s:64:64-f80:128:128");
430       mod->setTargetTriple("x86_64-unknown-linux-gnu");
431 
432       // Type Definitions
433       std::vector<Type*>FuncTy_0_args;
434       FunctionType *FuncTy_0 = FunctionType::get(
435           /*Result=*/IntegerType::get(Context, 32),
436           /*Params=*/FuncTy_0_args,
437           /*isVarArg=*/false);
438 
439       std::vector<Type*>FuncTy_2_args;
440       FuncTy_2_args.push_back(IntegerType::get(Context, 1));
441       FunctionType *FuncTy_2 = FunctionType::get(
442           /*Result=*/Type::getVoidTy(Context),
443           /*Params=*/FuncTy_2_args,
444           /*isVarArg=*/false);
445 
446       // Function Declarations
447 
448       Function* func_test1 = Function::Create(
449         /*Type=*/FuncTy_0,
450         /*Linkage=*/GlobalValue::ExternalLinkage,
451         /*Name=*/"test1", mod);
452       func_test1->setCallingConv(CallingConv::C);
453       AttributeList func_test1_PAL;
454       func_test1->setAttributes(func_test1_PAL);
455 
456       Function* func_test2 = Function::Create(
457         /*Type=*/FuncTy_0,
458         /*Linkage=*/GlobalValue::ExternalLinkage,
459         /*Name=*/"test2", mod);
460       func_test2->setCallingConv(CallingConv::C);
461       AttributeList func_test2_PAL;
462       func_test2->setAttributes(func_test2_PAL);
463 
464       Function* func_test3 = Function::Create(
465         /*Type=*/FuncTy_0,
466         /*Linkage=*/GlobalValue::InternalLinkage,
467         /*Name=*/"test3", mod);
468       func_test3->setCallingConv(CallingConv::C);
469       AttributeList func_test3_PAL;
470       func_test3->setAttributes(func_test3_PAL);
471 
472       Function* func_test4 = Function::Create(
473         /*Type=*/FuncTy_2,
474         /*Linkage=*/GlobalValue::ExternalLinkage,
475         /*Name=*/"test4", mod);
476       func_test4->setCallingConv(CallingConv::C);
477       AttributeList func_test4_PAL;
478       func_test4->setAttributes(func_test4_PAL);
479 
480       // Global Variable Declarations
481 
482 
483       // Constant Definitions
484 
485       // Global Variable Definitions
486 
487       // Function Definitions
488 
489       // Function: test1 (func_test1)
490       {
491 
492         BasicBlock *label_entry =
493             BasicBlock::Create(Context, "entry", func_test1, nullptr);
494 
495         // Block entry (label_entry)
496         CallInst* int32_3 = CallInst::Create(func_test2, "", label_entry);
497         int32_3->setCallingConv(CallingConv::C);
498         int32_3->setTailCall(false);
499         AttributeList int32_3_PAL;
500         int32_3->setAttributes(int32_3_PAL);
501 
502         ReturnInst::Create(Context, int32_3, label_entry);
503       }
504 
505       // Function: test2 (func_test2)
506       {
507 
508         BasicBlock *label_entry_5 =
509             BasicBlock::Create(Context, "entry", func_test2, nullptr);
510 
511         // Block entry (label_entry_5)
512         CallInst* int32_6 = CallInst::Create(func_test3, "", label_entry_5);
513         int32_6->setCallingConv(CallingConv::C);
514         int32_6->setTailCall(false);
515         AttributeList int32_6_PAL;
516         int32_6->setAttributes(int32_6_PAL);
517 
518         ReturnInst::Create(Context, int32_6, label_entry_5);
519       }
520 
521       // Function: test3 (func_test3)
522       {
523 
524         BasicBlock *label_entry_8 =
525             BasicBlock::Create(Context, "entry", func_test3, nullptr);
526 
527         // Block entry (label_entry_8)
528         CallInst* int32_9 = CallInst::Create(func_test1, "", label_entry_8);
529         int32_9->setCallingConv(CallingConv::C);
530         int32_9->setTailCall(false);
531         AttributeList int32_9_PAL;
532         int32_9->setAttributes(int32_9_PAL);
533 
534         ReturnInst::Create(Context, int32_9, label_entry_8);
535       }
536 
537       // Function: test4 (func_test4)
538       {
539         Function::arg_iterator args = func_test4->arg_begin();
540         Value *int1_f = &*args++;
541         int1_f->setName("f");
542 
543         BasicBlock *label_entry_11 =
544             BasicBlock::Create(Context, "entry", func_test4, nullptr);
545         BasicBlock *label_bb =
546             BasicBlock::Create(Context, "bb", func_test4, nullptr);
547         BasicBlock *label_bb1 =
548             BasicBlock::Create(Context, "bb1", func_test4, nullptr);
549         BasicBlock *label_return =
550             BasicBlock::Create(Context, "return", func_test4, nullptr);
551 
552         // Block entry (label_entry_11)
553         auto *AI = new AllocaInst(func_test3->getType(), 0, "func3ptr",
554                                   label_entry_11);
555         new StoreInst(func_test3, AI, label_entry_11);
556         BranchInst::Create(label_bb, label_entry_11);
557 
558         // Block bb (label_bb)
559         BranchInst::Create(label_bb, label_bb1, int1_f, label_bb);
560 
561         // Block bb1 (label_bb1)
562         BranchInst::Create(label_bb1, label_return, int1_f, label_bb1);
563 
564         // Block return (label_return)
565         ReturnInst::Create(Context, label_return);
566       }
567       return mod;
568     }
569 
570     /// Split a simple function which contains only a call and a return into two
571     /// such that the first calls the second and the second whoever was called
572     /// initially.
573     Function *splitSimpleFunction(Function &F) {
574       LLVMContext &Context = F.getContext();
575       Function *SF = Function::Create(F.getFunctionType(), F.getLinkage(),
576                                       F.getName() + "b", F.getParent());
577       F.setName(F.getName() + "a");
578       BasicBlock *Entry = BasicBlock::Create(Context, "entry", SF, nullptr);
579       CallInst &CI = cast<CallInst>(F.getEntryBlock().front());
580       CI.clone()->insertBefore(ReturnInst::Create(Context, Entry));
581       CI.setCalledFunction(SF);
582       return SF;
583     }
584 
585     struct CGModifierPass : public CGPass {
586       unsigned NumSCCs = 0;
587       unsigned NumFns = 0;
588       unsigned NumFnDecls = 0;
589       unsigned SetupWorked = 0;
590       unsigned NumExtCalledBefore = 0;
591       unsigned NumExtCalledAfter = 0;
592 
593       CallGraphUpdater CGU;
594 
595       bool runOnSCC(CallGraphSCC &SCMM) override {
596         ++NumSCCs;
597         for (CallGraphNode *N : SCMM) {
598           if (N->getFunction()){
599             ++NumFns;
600             NumFnDecls += N->getFunction()->isDeclaration();
601           }
602         }
603         CGPass::run();
604 
605         CallGraph &CG = const_cast<CallGraph &>(SCMM.getCallGraph());
606         CallGraphNode *ExtCallingNode = CG.getExternalCallingNode();
607         NumExtCalledBefore = ExtCallingNode->size();
608 
609         if (SCMM.size() <= 1)
610           return false;
611 
612         CallGraphNode *N = *(SCMM.begin());
613         Function *F = N->getFunction();
614         Module *M = F->getParent();
615         Function *Test1F = M->getFunction("test1");
616         Function *Test2aF = M->getFunction("test2a");
617         Function *Test2bF = M->getFunction("test2b");
618         Function *Test3F = M->getFunction("test3");
619 
620         auto InSCC = [&](Function *Fn) {
621           return llvm::any_of(SCMM, [Fn](CallGraphNode *CGN) {
622             return CGN->getFunction() == Fn;
623           });
624         };
625 
626         if (!Test1F || !Test2aF || !Test2bF || !Test3F || !InSCC(Test1F) ||
627             !InSCC(Test2aF) || !InSCC(Test2bF) || !InSCC(Test3F))
628           return false;
629 
630         CallInst *CI = dyn_cast<CallInst>(&Test1F->getEntryBlock().front());
631         if (!CI || CI->getCalledFunction() != Test2aF)
632           return false;
633 
634         SetupWorked += 1;
635 
636         // Create a replica of test3 and just move the blocks there.
637         Function *Test3FRepl = Function::Create(
638             /*Type=*/Test3F->getFunctionType(),
639             /*Linkage=*/GlobalValue::InternalLinkage,
640             /*Name=*/"test3repl", Test3F->getParent());
641         while (!Test3F->empty()) {
642           BasicBlock &BB = Test3F->front();
643           BB.removeFromParent();
644           BB.insertInto(Test3FRepl);
645         }
646 
647         CGU.initialize(CG, SCMM);
648 
649         // Replace test3 with the replica. This is legal as it is actually
650         // internal and the "capturing use" is not really capturing anything.
651         CGU.replaceFunctionWith(*Test3F, *Test3FRepl);
652         Test3F->replaceAllUsesWith(Test3FRepl);
653 
654         // Rewrite the call in test1 to point to the replica of 3 not test2.
655         CI->setCalledFunction(Test3FRepl);
656 
657         // Delete test2a and test2b and reanalyze 1 as we changed calls inside.
658         CGU.removeFunction(*Test2aF);
659         CGU.removeFunction(*Test2bF);
660         CGU.reanalyzeFunction(*Test1F);
661 
662         return true;
663       }
664 
665       bool doFinalization(CallGraph &CG) override {
666         CGU.finalize();
667         // We removed test2 and replaced the internal test3.
668         NumExtCalledAfter = CG.getExternalCallingNode()->size();
669         return true;
670       }
671     };
672 
673     TEST(PassManager, CallGraphUpdater0) {
674       // SCC#1: test1->test2a->test2b->test3->test1
675       // SCC#2: test4
676       // SCC#3: test3 (the empty function declaration as we replaced it with
677       //               test3repl when we visited SCC#1)
678       // SCC#4: test2a->test2b (the empty function declarations as we deleted
679       //                        these functions when we visited SCC#1)
680       // SCC#5: indirect call node
681 
682       LLVMContext Context;
683       std::unique_ptr<Module> M(makeLLVMModule(Context));
684       ASSERT_EQ(M->getFunctionList().size(), 4U);
685       Function *F = M->getFunction("test2");
686       Function *SF = splitSimpleFunction(*F);
687       CallInst::Create(F, "", &*SF->getEntryBlock().getFirstInsertionPt());
688       ASSERT_EQ(M->getFunctionList().size(), 5U);
689       CGModifierPass *P = new CGModifierPass();
690       legacy::PassManager Passes;
691       Passes.add(P);
692       Passes.run(*M);
693       ASSERT_EQ(P->SetupWorked, 1U);
694       ASSERT_EQ(P->NumSCCs, 4U);
695       ASSERT_EQ(P->NumFns, 6U);
696       ASSERT_EQ(P->NumFnDecls, 1U);
697       ASSERT_EQ(M->getFunctionList().size(), 3U);
698       ASSERT_EQ(P->NumExtCalledBefore, /* test1, 2a, 2b, 3, 4 */ 5U);
699       ASSERT_EQ(P->NumExtCalledAfter, /* test1, 3repl, 4 */ 3U);
700     }
701 
702     // Test for call graph SCC pass that replaces all callback call instructions
703     // with clones and updates CallGraph by calling CallGraph::replaceCallEdge()
704     // method. Test is expected to complete successfully after running pass on
705     // all SCCs in the test module.
706     struct CallbackCallsModifierPass : public CGPass {
707       bool runOnSCC(CallGraphSCC &SCC) override {
708         CGPass::run();
709 
710         CallGraph &CG = const_cast<CallGraph &>(SCC.getCallGraph());
711 
712         bool Changed = false;
713         for (CallGraphNode *CGN : SCC) {
714           Function *F = CGN->getFunction();
715           if (!F || F->isDeclaration())
716             continue;
717 
718           SmallVector<CallBase *, 4u> Calls;
719           for (Use &U : F->uses()) {
720             AbstractCallSite ACS(&U);
721             if (!ACS || !ACS.isCallbackCall() || !ACS.isCallee(&U))
722               continue;
723             Calls.push_back(cast<CallBase>(ACS.getInstruction()));
724           }
725           if (Calls.empty())
726             continue;
727 
728           for (CallBase *OldCB : Calls) {
729             CallGraphNode *CallerCGN = CG[OldCB->getParent()->getParent()];
730             assert(any_of(*CallerCGN,
731                           [CGN](const CallGraphNode::CallRecord &CallRecord) {
732                             return CallRecord.second == CGN;
733                           }) &&
734                    "function is not a callee");
735 
736             CallBase *NewCB = cast<CallBase>(OldCB->clone());
737 
738             NewCB->insertBefore(OldCB);
739             NewCB->takeName(OldCB);
740 
741             CallerCGN->replaceCallEdge(*OldCB, *NewCB, CG[F]);
742 
743             OldCB->replaceAllUsesWith(NewCB);
744             OldCB->eraseFromParent();
745           }
746           Changed = true;
747         }
748         return Changed;
749       }
750     };
751 
752     TEST(PassManager, CallbackCallsModifier0) {
753       LLVMContext Context;
754 
755       const char *IR = "define void @foo() {\n"
756                        "  call void @broker(void (i8*)* @callback0, i8* null)\n"
757                        "  call void @broker(void (i8*)* @callback1, i8* null)\n"
758                        "  ret void\n"
759                        "}\n"
760                        "\n"
761                        "declare !callback !0 void @broker(void (i8*)*, i8*)\n"
762                        "\n"
763                        "define internal void @callback0(i8* %arg) {\n"
764                        "  ret void\n"
765                        "}\n"
766                        "\n"
767                        "define internal void @callback1(i8* %arg) {\n"
768                        "  ret void\n"
769                        "}\n"
770                        "\n"
771                        "!0 = !{!1}\n"
772                        "!1 = !{i64 0, i64 1, i1 false}";
773 
774       SMDiagnostic Err;
775       std::unique_ptr<Module> M = parseAssemblyString(IR, Err, Context);
776       if (!M)
777         Err.print("LegacyPassManagerTest", errs());
778 
779       CallbackCallsModifierPass *P = new CallbackCallsModifierPass();
780       legacy::PassManager Passes;
781       Passes.add(P);
782       Passes.run(*M);
783     }
784   }
785 }
786 
787 INITIALIZE_PASS(ModuleNDM, "mndm", "mndm", false, false)
788 INITIALIZE_PASS_BEGIN(CGPass, "cgp","cgp", false, false)
789 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
790 INITIALIZE_PASS_END(CGPass, "cgp","cgp", false, false)
791 INITIALIZE_PASS(FPass, "fp","fp", false, false)
792 INITIALIZE_PASS_BEGIN(LPass, "lp","lp", false, false)
793 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
794 INITIALIZE_PASS_END(LPass, "lp","lp", false, false)
795