1 //===- GCOVProfiling.cpp - Insert edge counters for gcov profiling --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass implements GCOV-style profiling. When this pass is run it emits
11 // "gcno" files next to the existing source, and instruments the code that runs
12 // to records the edges between blocks that run and emit a complementary "gcda"
15 //===----------------------------------------------------------------------===//
17 #include "llvm/Transforms/Instrumentation.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/Hashing.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/StringMap.h"
24 #include "llvm/ADT/UniqueVector.h"
25 #include "llvm/IR/DebugInfo.h"
26 #include "llvm/IR/DebugLoc.h"
27 #include "llvm/IR/IRBuilder.h"
28 #include "llvm/IR/InstIterator.h"
29 #include "llvm/IR/Instructions.h"
30 #include "llvm/IR/IntrinsicInst.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/Pass.h"
33 #include "llvm/Support/CommandLine.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/FileSystem.h"
36 #include "llvm/Support/Path.h"
37 #include "llvm/Support/raw_ostream.h"
38 #include "llvm/Transforms/Utils/ModuleUtils.h"
45 #define DEBUG_TYPE "insert-gcov-profiling"
47 static cl::opt<std::string>
48 DefaultGCOVVersion("default-gcov-version", cl::init("402*"), cl::Hidden,
51 GCOVOptions GCOVOptions::getDefault() {
53 Options.EmitNotes = true;
54 Options.EmitData = true;
55 Options.UseCfgChecksum = false;
56 Options.NoRedZone = false;
57 Options.FunctionNamesInData = true;
59 if (DefaultGCOVVersion.size() != 4) {
60 llvm::report_fatal_error(std::string("Invalid -default-gcov-version: ") +
63 memcpy(Options.Version, DefaultGCOVVersion.c_str(), 4);
70 class GCOVProfiler : public ModulePass {
73 GCOVProfiler() : ModulePass(ID), Options(GCOVOptions::getDefault()) {
76 GCOVProfiler(const GCOVOptions &Options) : ModulePass(ID), Options(Options){
77 assert((Options.EmitNotes || Options.EmitData) &&
78 "GCOVProfiler asked to do nothing?");
81 const char *getPassName() const override {
82 return "GCOV Profiler";
87 ReversedVersion[0] = Options.Version[3];
88 ReversedVersion[1] = Options.Version[2];
89 ReversedVersion[2] = Options.Version[1];
90 ReversedVersion[3] = Options.Version[0];
91 ReversedVersion[4] = '\0';
92 initializeGCOVProfilerPass(*PassRegistry::getPassRegistry());
94 bool runOnModule(Module &M) override;
96 // Create the .gcno files for the Module based on DebugInfo.
97 void emitProfileNotes();
99 // Modify the program to track transitions along edges and call into the
100 // profiling runtime to emit .gcda files when run.
101 bool emitProfileArcs();
103 // Get pointers to the functions in the runtime library.
104 Constant *getStartFileFunc();
105 Constant *getIncrementIndirectCounterFunc();
106 Constant *getEmitFunctionFunc();
107 Constant *getEmitArcsFunc();
108 Constant *getSummaryInfoFunc();
109 Constant *getDeleteWriteoutFunctionListFunc();
110 Constant *getDeleteFlushFunctionListFunc();
111 Constant *getEndFileFunc();
113 // Create or retrieve an i32 state value that is used to represent the
114 // pred block number for certain non-trivial edges.
115 GlobalVariable *getEdgeStateValue();
117 // Produce a table of pointers to counters, by predecessor and successor
119 GlobalVariable *buildEdgeLookupTable(Function *F,
120 GlobalVariable *Counter,
121 const UniqueVector<BasicBlock *>&Preds,
122 const UniqueVector<BasicBlock*>&Succs);
124 // Add the function to write out all our counters to the global destructor
126 Function *insertCounterWriteout(ArrayRef<std::pair<GlobalVariable*,
128 Function *insertFlush(ArrayRef<std::pair<GlobalVariable*, MDNode*> >);
129 void insertIndirectCounterIncrement();
131 std::string mangleName(DICompileUnit CU, const char *NewStem);
135 // Reversed, NUL-terminated copy of Options.Version.
136 char ReversedVersion[5];
137 // Checksum, produced by hash of EdgeDestinations
138 SmallVector<uint32_t, 4> FileChecksums;
142 SmallVector<std::unique_ptr<GCOVFunction>, 16> Funcs;
146 char GCOVProfiler::ID = 0;
147 INITIALIZE_PASS(GCOVProfiler, "insert-gcov-profiling",
148 "Insert instrumentation for GCOV profiling", false, false)
150 ModulePass *llvm::createGCOVProfilerPass(const GCOVOptions &Options) {
151 return new GCOVProfiler(Options);
154 static StringRef getFunctionName(DISubprogram SP) {
155 if (!SP.getLinkageName().empty())
156 return SP.getLinkageName();
163 static const char *const LinesTag;
164 static const char *const FunctionTag;
165 static const char *const BlockTag;
166 static const char *const EdgeTag;
170 void writeBytes(const char *Bytes, int Size) {
171 os->write(Bytes, Size);
174 void write(uint32_t i) {
175 writeBytes(reinterpret_cast<char*>(&i), 4);
178 // Returns the length measured in 4-byte blocks that will be used to
179 // represent this string in a GCOV file
180 static unsigned lengthOfGCOVString(StringRef s) {
181 // A GCOV string is a length, followed by a NUL, then between 0 and 3 NULs
182 // padding out to the next 4-byte word. The length is measured in 4-byte
183 // words including padding, not bytes of actual string.
184 return (s.size() / 4) + 1;
187 void writeGCOVString(StringRef s) {
188 uint32_t Len = lengthOfGCOVString(s);
190 writeBytes(s.data(), s.size());
192 // Write 1 to 4 bytes of NUL padding.
193 assert((unsigned)(4 - (s.size() % 4)) > 0);
194 assert((unsigned)(4 - (s.size() % 4)) <= 4);
195 writeBytes("\0\0\0\0", 4 - (s.size() % 4));
200 const char *const GCOVRecord::LinesTag = "\0\0\x45\x01";
201 const char *const GCOVRecord::FunctionTag = "\0\0\0\1";
202 const char *const GCOVRecord::BlockTag = "\0\0\x41\x01";
203 const char *const GCOVRecord::EdgeTag = "\0\0\x43\x01";
208 // Constructed only by requesting it from a GCOVBlock, this object stores a
209 // list of line numbers and a single filename, representing lines that belong
211 class GCOVLines : public GCOVRecord {
213 void addLine(uint32_t Line) {
214 assert(Line != 0 && "Line zero is not a valid real line number.");
215 Lines.push_back(Line);
218 uint32_t length() const {
219 // Here 2 = 1 for string length + 1 for '0' id#.
220 return lengthOfGCOVString(Filename) + 2 + Lines.size();
225 writeGCOVString(Filename);
226 for (int i = 0, e = Lines.size(); i != e; ++i)
230 GCOVLines(StringRef F, raw_ostream *os)
237 SmallVector<uint32_t, 32> Lines;
241 // Represent a basic block in GCOV. Each block has a unique number in the
242 // function, number of lines belonging to each block, and a set of edges to
244 class GCOVBlock : public GCOVRecord {
246 GCOVLines &getFile(StringRef Filename) {
247 GCOVLines *&Lines = LinesByFile[Filename];
249 Lines = new GCOVLines(Filename, os);
254 void addEdge(GCOVBlock &Successor) {
255 OutEdges.push_back(&Successor);
260 SmallVector<StringMapEntry<GCOVLines *> *, 32> SortedLinesByFile;
261 for (StringMap<GCOVLines *>::iterator I = LinesByFile.begin(),
262 E = LinesByFile.end(); I != E; ++I) {
263 Len += I->second->length();
264 SortedLinesByFile.push_back(&*I);
267 writeBytes(LinesTag, 4);
271 std::sort(SortedLinesByFile.begin(), SortedLinesByFile.end(),
272 [](StringMapEntry<GCOVLines *> *LHS,
273 StringMapEntry<GCOVLines *> *RHS) {
274 return LHS->getKey() < RHS->getKey();
276 for (SmallVectorImpl<StringMapEntry<GCOVLines *> *>::iterator
277 I = SortedLinesByFile.begin(), E = SortedLinesByFile.end();
279 (*I)->getValue()->writeOut();
285 DeleteContainerSeconds(LinesByFile);
288 GCOVBlock(const GCOVBlock &RHS) : GCOVRecord(RHS), Number(RHS.Number) {
289 // Only allow copy before edges and lines have been added. After that,
290 // there are inter-block pointers (eg: edges) that won't take kindly to
291 // blocks being copied or moved around.
292 assert(LinesByFile.empty());
293 assert(OutEdges.empty());
297 friend class GCOVFunction;
299 GCOVBlock(uint32_t Number, raw_ostream *os)
305 StringMap<GCOVLines *> LinesByFile;
306 SmallVector<GCOVBlock *, 4> OutEdges;
309 // A function has a unique identifier, a checksum (we leave as zero) and a
310 // set of blocks and a map of edges between blocks. This is the only GCOV
311 // object users can construct, the blocks and lines will be rooted here.
312 class GCOVFunction : public GCOVRecord {
314 GCOVFunction(DISubprogram SP, raw_ostream *os, uint32_t Ident,
316 : SP(SP), Ident(Ident), UseCfgChecksum(UseCfgChecksum), CfgChecksum(0),
320 Function *F = SP.getFunction();
321 DEBUG(dbgs() << "Function: " << getFunctionName(SP) << "\n");
324 for (auto &BB : *F) {
325 // Skip index 1 (0, 2, 3, 4, ...) because that's assigned to the
328 Blocks.insert(std::make_pair(&BB, GCOVBlock(i++ + !first, os)));
331 std::string FunctionNameAndLine;
332 raw_string_ostream FNLOS(FunctionNameAndLine);
333 FNLOS << getFunctionName(SP) << SP.getLineNumber();
335 FuncChecksum = hash_value(FunctionNameAndLine);
338 GCOVBlock &getBlock(BasicBlock *BB) {
339 return Blocks.find(BB)->second;
342 GCOVBlock &getReturnBlock() {
346 std::string getEdgeDestinations() {
347 std::string EdgeDestinations;
348 raw_string_ostream EDOS(EdgeDestinations);
349 Function *F = Blocks.begin()->first->getParent();
350 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
351 GCOVBlock &Block = getBlock(I);
352 for (int i = 0, e = Block.OutEdges.size(); i != e; ++i)
353 EDOS << Block.OutEdges[i]->Number;
355 return EdgeDestinations;
358 uint32_t getFuncChecksum() {
362 void setCfgChecksum(uint32_t Checksum) {
363 CfgChecksum = Checksum;
367 writeBytes(FunctionTag, 4);
368 uint32_t BlockLen = 1 + 1 + 1 + lengthOfGCOVString(getFunctionName(SP)) +
369 1 + lengthOfGCOVString(SP.getFilename()) + 1;
377 writeGCOVString(getFunctionName(SP));
378 writeGCOVString(SP.getFilename());
379 write(SP.getLineNumber());
381 // Emit count of blocks.
382 writeBytes(BlockTag, 4);
383 write(Blocks.size() + 1);
384 for (int i = 0, e = Blocks.size() + 1; i != e; ++i) {
385 write(0); // No flags on our blocks.
387 DEBUG(dbgs() << Blocks.size() << " blocks.\n");
389 // Emit edges between blocks.
390 if (Blocks.empty()) return;
391 Function *F = Blocks.begin()->first->getParent();
392 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
393 GCOVBlock &Block = getBlock(I);
394 if (Block.OutEdges.empty()) continue;
396 writeBytes(EdgeTag, 4);
397 write(Block.OutEdges.size() * 2 + 1);
399 for (int i = 0, e = Block.OutEdges.size(); i != e; ++i) {
400 DEBUG(dbgs() << Block.Number << " -> " << Block.OutEdges[i]->Number
402 write(Block.OutEdges[i]->Number);
403 write(0); // no flags
407 // Emit lines for each block.
408 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
409 getBlock(I).writeOut();
416 uint32_t FuncChecksum;
418 uint32_t CfgChecksum;
419 DenseMap<BasicBlock *, GCOVBlock> Blocks;
420 GCOVBlock ReturnBlock;
424 std::string GCOVProfiler::mangleName(DICompileUnit CU, const char *NewStem) {
425 if (NamedMDNode *GCov = M->getNamedMetadata("llvm.gcov")) {
426 for (int i = 0, e = GCov->getNumOperands(); i != e; ++i) {
427 MDNode *N = GCov->getOperand(i);
428 if (N->getNumOperands() != 2) continue;
429 MDString *GCovFile = dyn_cast<MDString>(N->getOperand(0));
430 MDNode *CompileUnit = dyn_cast<MDNode>(N->getOperand(1));
431 if (!GCovFile || !CompileUnit) continue;
432 if (CompileUnit == CU) {
433 SmallString<128> Filename = GCovFile->getString();
434 sys::path::replace_extension(Filename, NewStem);
435 return Filename.str();
440 SmallString<128> Filename = CU.getFilename();
441 sys::path::replace_extension(Filename, NewStem);
442 StringRef FName = sys::path::filename(Filename);
443 SmallString<128> CurPath;
444 if (sys::fs::current_path(CurPath)) return FName;
445 sys::path::append(CurPath, FName.str());
446 return CurPath.str();
449 bool GCOVProfiler::runOnModule(Module &M) {
451 Ctx = &M.getContext();
453 if (Options.EmitNotes) emitProfileNotes();
454 if (Options.EmitData) return emitProfileArcs();
458 static bool functionHasLines(Function *F) {
459 // Check whether this function actually has any source lines. Not only
460 // do these waste space, they also can crash gcov.
461 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
462 for (BasicBlock::iterator I = BB->begin(), IE = BB->end();
464 // Debug intrinsic locations correspond to the location of the
465 // declaration, not necessarily any statements or expressions.
466 if (isa<DbgInfoIntrinsic>(I)) continue;
468 const DebugLoc &Loc = I->getDebugLoc();
469 if (Loc.isUnknown()) continue;
471 // Artificial lines such as calls to the global constructors.
472 if (Loc.getLine() == 0) continue;
480 void GCOVProfiler::emitProfileNotes() {
481 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
482 if (!CU_Nodes) return;
484 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
485 // Each compile unit gets its own .gcno file. This means that whether we run
486 // this pass over the original .o's as they're produced, or run it after
487 // LTO, we'll generate the same .gcno files.
489 DICompileUnit CU(CU_Nodes->getOperand(i));
491 raw_fd_ostream out(mangleName(CU, "gcno"), EC, sys::fs::F_None);
492 std::string EdgeDestinations;
494 DIArray SPs = CU.getSubprograms();
495 unsigned FunctionIdent = 0;
496 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
497 DISubprogram SP(SPs.getElement(i));
498 assert((!SP || SP.isSubprogram()) &&
499 "A MDNode in subprograms of a CU should be null or a DISubprogram.");
503 Function *F = SP.getFunction();
505 if (!functionHasLines(F)) continue;
507 // gcov expects every function to start with an entry block that has a
508 // single successor, so split the entry block to make sure of that.
509 BasicBlock &EntryBlock = F->getEntryBlock();
510 BasicBlock::iterator It = EntryBlock.begin();
511 while (isa<AllocaInst>(*It) || isa<DbgInfoIntrinsic>(*It))
513 EntryBlock.splitBasicBlock(It);
515 Funcs.push_back(make_unique<GCOVFunction>(SP, &out, FunctionIdent++,
516 Options.UseCfgChecksum));
517 GCOVFunction &Func = *Funcs.back();
519 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
520 GCOVBlock &Block = Func.getBlock(BB);
521 TerminatorInst *TI = BB->getTerminator();
522 if (int successors = TI->getNumSuccessors()) {
523 for (int i = 0; i != successors; ++i) {
524 Block.addEdge(Func.getBlock(TI->getSuccessor(i)));
526 } else if (isa<ReturnInst>(TI)) {
527 Block.addEdge(Func.getReturnBlock());
531 for (BasicBlock::iterator I = BB->begin(), IE = BB->end();
533 // Debug intrinsic locations correspond to the location of the
534 // declaration, not necessarily any statements or expressions.
535 if (isa<DbgInfoIntrinsic>(I)) continue;
537 const DebugLoc &Loc = I->getDebugLoc();
538 if (Loc.isUnknown()) continue;
540 // Artificial lines such as calls to the global constructors.
541 if (Loc.getLine() == 0) continue;
543 if (Line == Loc.getLine()) continue;
544 Line = Loc.getLine();
545 if (SP != getDISubprogram(Loc.getScope(*Ctx))) continue;
547 GCOVLines &Lines = Block.getFile(SP.getFilename());
548 Lines.addLine(Loc.getLine());
551 EdgeDestinations += Func.getEdgeDestinations();
554 FileChecksums.push_back(hash_value(EdgeDestinations));
555 out.write("oncg", 4);
556 out.write(ReversedVersion, 4);
557 out.write(reinterpret_cast<char*>(&FileChecksums.back()), 4);
559 for (auto &Func : Funcs) {
560 Func->setCfgChecksum(FileChecksums.back());
564 out.write("\0\0\0\0\0\0\0\0", 8); // EOF
569 bool GCOVProfiler::emitProfileArcs() {
570 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
571 if (!CU_Nodes) return false;
574 bool InsertIndCounterIncrCode = false;
575 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
576 DICompileUnit CU(CU_Nodes->getOperand(i));
577 DIArray SPs = CU.getSubprograms();
578 SmallVector<std::pair<GlobalVariable *, MDNode *>, 8> CountersBySP;
579 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
580 DISubprogram SP(SPs.getElement(i));
581 assert((!SP || SP.isSubprogram()) &&
582 "A MDNode in subprograms of a CU should be null or a DISubprogram.");
585 Function *F = SP.getFunction();
587 if (!functionHasLines(F)) continue;
588 if (!Result) Result = true;
590 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
591 TerminatorInst *TI = BB->getTerminator();
592 if (isa<ReturnInst>(TI))
595 Edges += TI->getNumSuccessors();
598 ArrayType *CounterTy =
599 ArrayType::get(Type::getInt64Ty(*Ctx), Edges);
600 GlobalVariable *Counters =
601 new GlobalVariable(*M, CounterTy, false,
602 GlobalValue::InternalLinkage,
603 Constant::getNullValue(CounterTy),
605 CountersBySP.push_back(std::make_pair(Counters, (MDNode*)SP));
607 UniqueVector<BasicBlock *> ComplexEdgePreds;
608 UniqueVector<BasicBlock *> ComplexEdgeSuccs;
611 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
612 TerminatorInst *TI = BB->getTerminator();
613 int Successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
615 if (Successors == 1) {
616 IRBuilder<> Builder(BB->getFirstInsertionPt());
617 Value *Counter = Builder.CreateConstInBoundsGEP2_64(Counters, 0,
619 Value *Count = Builder.CreateLoad(Counter);
620 Count = Builder.CreateAdd(Count, Builder.getInt64(1));
621 Builder.CreateStore(Count, Counter);
622 } else if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
623 IRBuilder<> Builder(BI);
624 Value *Sel = Builder.CreateSelect(BI->getCondition(),
625 Builder.getInt64(Edge),
626 Builder.getInt64(Edge + 1));
627 SmallVector<Value *, 2> Idx;
628 Idx.push_back(Builder.getInt64(0));
630 Value *Counter = Builder.CreateInBoundsGEP(Counters, Idx);
631 Value *Count = Builder.CreateLoad(Counter);
632 Count = Builder.CreateAdd(Count, Builder.getInt64(1));
633 Builder.CreateStore(Count, Counter);
635 ComplexEdgePreds.insert(BB);
636 for (int i = 0; i != Successors; ++i)
637 ComplexEdgeSuccs.insert(TI->getSuccessor(i));
644 if (!ComplexEdgePreds.empty()) {
645 GlobalVariable *EdgeTable =
646 buildEdgeLookupTable(F, Counters,
647 ComplexEdgePreds, ComplexEdgeSuccs);
648 GlobalVariable *EdgeState = getEdgeStateValue();
650 for (int i = 0, e = ComplexEdgePreds.size(); i != e; ++i) {
651 IRBuilder<> Builder(ComplexEdgePreds[i + 1]->getFirstInsertionPt());
652 Builder.CreateStore(Builder.getInt32(i), EdgeState);
655 for (int i = 0, e = ComplexEdgeSuccs.size(); i != e; ++i) {
656 // Call runtime to perform increment.
657 IRBuilder<> Builder(ComplexEdgeSuccs[i+1]->getFirstInsertionPt());
658 Value *CounterPtrArray =
659 Builder.CreateConstInBoundsGEP2_64(EdgeTable, 0,
660 i * ComplexEdgePreds.size());
662 // Build code to increment the counter.
663 InsertIndCounterIncrCode = true;
664 Builder.CreateCall2(getIncrementIndirectCounterFunc(),
665 EdgeState, CounterPtrArray);
670 Function *WriteoutF = insertCounterWriteout(CountersBySP);
671 Function *FlushF = insertFlush(CountersBySP);
673 // Create a small bit of code that registers the "__llvm_gcov_writeout" to
674 // be executed at exit and the "__llvm_gcov_flush" function to be executed
675 // when "__gcov_flush" is called.
676 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
677 Function *F = Function::Create(FTy, GlobalValue::InternalLinkage,
678 "__llvm_gcov_init", M);
679 F->setUnnamedAddr(true);
680 F->setLinkage(GlobalValue::InternalLinkage);
681 F->addFnAttr(Attribute::NoInline);
682 if (Options.NoRedZone)
683 F->addFnAttr(Attribute::NoRedZone);
685 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", F);
686 IRBuilder<> Builder(BB);
688 FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
690 PointerType::get(FTy, 0),
691 PointerType::get(FTy, 0)
693 FTy = FunctionType::get(Builder.getVoidTy(), Params, false);
695 // Initialize the environment and register the local writeout and flush
697 Constant *GCOVInit = M->getOrInsertFunction("llvm_gcov_init", FTy);
698 Builder.CreateCall2(GCOVInit, WriteoutF, FlushF);
699 Builder.CreateRetVoid();
701 appendToGlobalCtors(*M, F, 0);
704 if (InsertIndCounterIncrCode)
705 insertIndirectCounterIncrement();
710 // All edges with successors that aren't branches are "complex", because it
711 // requires complex logic to pick which counter to update.
712 GlobalVariable *GCOVProfiler::buildEdgeLookupTable(
714 GlobalVariable *Counters,
715 const UniqueVector<BasicBlock *> &Preds,
716 const UniqueVector<BasicBlock *> &Succs) {
717 // TODO: support invoke, threads. We rely on the fact that nothing can modify
718 // the whole-Module pred edge# between the time we set it and the time we next
719 // read it. Threads and invoke make this untrue.
721 // emit [(succs * preds) x i64*], logically [succ x [pred x i64*]].
722 size_t TableSize = Succs.size() * Preds.size();
723 Type *Int64PtrTy = Type::getInt64PtrTy(*Ctx);
724 ArrayType *EdgeTableTy = ArrayType::get(Int64PtrTy, TableSize);
726 std::unique_ptr<Constant * []> EdgeTable(new Constant *[TableSize]);
727 Constant *NullValue = Constant::getNullValue(Int64PtrTy);
728 for (size_t i = 0; i != TableSize; ++i)
729 EdgeTable[i] = NullValue;
732 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
733 TerminatorInst *TI = BB->getTerminator();
734 int Successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
735 if (Successors > 1 && !isa<BranchInst>(TI) && !isa<ReturnInst>(TI)) {
736 for (int i = 0; i != Successors; ++i) {
737 BasicBlock *Succ = TI->getSuccessor(i);
738 IRBuilder<> Builder(Succ);
739 Value *Counter = Builder.CreateConstInBoundsGEP2_64(Counters, 0,
741 EdgeTable[((Succs.idFor(Succ)-1) * Preds.size()) +
742 (Preds.idFor(BB)-1)] = cast<Constant>(Counter);
748 GlobalVariable *EdgeTableGV =
750 *M, EdgeTableTy, true, GlobalValue::InternalLinkage,
751 ConstantArray::get(EdgeTableTy,
752 makeArrayRef(&EdgeTable[0],TableSize)),
753 "__llvm_gcda_edge_table");
754 EdgeTableGV->setUnnamedAddr(true);
758 Constant *GCOVProfiler::getStartFileFunc() {
760 Type::getInt8PtrTy(*Ctx), // const char *orig_filename
761 Type::getInt8PtrTy(*Ctx), // const char version[4]
762 Type::getInt32Ty(*Ctx), // uint32_t checksum
764 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
765 return M->getOrInsertFunction("llvm_gcda_start_file", FTy);
768 Constant *GCOVProfiler::getIncrementIndirectCounterFunc() {
769 Type *Int32Ty = Type::getInt32Ty(*Ctx);
770 Type *Int64Ty = Type::getInt64Ty(*Ctx);
772 Int32Ty->getPointerTo(), // uint32_t *predecessor
773 Int64Ty->getPointerTo()->getPointerTo() // uint64_t **counters
775 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
776 return M->getOrInsertFunction("__llvm_gcov_indirect_counter_increment", FTy);
779 Constant *GCOVProfiler::getEmitFunctionFunc() {
781 Type::getInt32Ty(*Ctx), // uint32_t ident
782 Type::getInt8PtrTy(*Ctx), // const char *function_name
783 Type::getInt32Ty(*Ctx), // uint32_t func_checksum
784 Type::getInt8Ty(*Ctx), // uint8_t use_extra_checksum
785 Type::getInt32Ty(*Ctx), // uint32_t cfg_checksum
787 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
788 return M->getOrInsertFunction("llvm_gcda_emit_function", FTy);
791 Constant *GCOVProfiler::getEmitArcsFunc() {
793 Type::getInt32Ty(*Ctx), // uint32_t num_counters
794 Type::getInt64PtrTy(*Ctx), // uint64_t *counters
796 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
797 return M->getOrInsertFunction("llvm_gcda_emit_arcs", FTy);
800 Constant *GCOVProfiler::getSummaryInfoFunc() {
801 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
802 return M->getOrInsertFunction("llvm_gcda_summary_info", FTy);
805 Constant *GCOVProfiler::getDeleteWriteoutFunctionListFunc() {
806 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
807 return M->getOrInsertFunction("llvm_delete_writeout_function_list", FTy);
810 Constant *GCOVProfiler::getDeleteFlushFunctionListFunc() {
811 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
812 return M->getOrInsertFunction("llvm_delete_flush_function_list", FTy);
815 Constant *GCOVProfiler::getEndFileFunc() {
816 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
817 return M->getOrInsertFunction("llvm_gcda_end_file", FTy);
820 GlobalVariable *GCOVProfiler::getEdgeStateValue() {
821 GlobalVariable *GV = M->getGlobalVariable("__llvm_gcov_global_state_pred");
823 GV = new GlobalVariable(*M, Type::getInt32Ty(*Ctx), false,
824 GlobalValue::InternalLinkage,
825 ConstantInt::get(Type::getInt32Ty(*Ctx),
827 "__llvm_gcov_global_state_pred");
828 GV->setUnnamedAddr(true);
833 Function *GCOVProfiler::insertCounterWriteout(
834 ArrayRef<std::pair<GlobalVariable *, MDNode *> > CountersBySP) {
835 FunctionType *WriteoutFTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
836 Function *WriteoutF = M->getFunction("__llvm_gcov_writeout");
838 WriteoutF = Function::Create(WriteoutFTy, GlobalValue::InternalLinkage,
839 "__llvm_gcov_writeout", M);
840 WriteoutF->setUnnamedAddr(true);
841 WriteoutF->addFnAttr(Attribute::NoInline);
842 if (Options.NoRedZone)
843 WriteoutF->addFnAttr(Attribute::NoRedZone);
845 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", WriteoutF);
846 IRBuilder<> Builder(BB);
848 Constant *StartFile = getStartFileFunc();
849 Constant *EmitFunction = getEmitFunctionFunc();
850 Constant *EmitArcs = getEmitArcsFunc();
851 Constant *SummaryInfo = getSummaryInfoFunc();
852 Constant *EndFile = getEndFileFunc();
854 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
856 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
857 DICompileUnit CU(CU_Nodes->getOperand(i));
858 std::string FilenameGcda = mangleName(CU, "gcda");
859 uint32_t CfgChecksum = FileChecksums.empty() ? 0 : FileChecksums[i];
860 Builder.CreateCall3(StartFile,
861 Builder.CreateGlobalStringPtr(FilenameGcda),
862 Builder.CreateGlobalStringPtr(ReversedVersion),
863 Builder.getInt32(CfgChecksum));
864 for (unsigned j = 0, e = CountersBySP.size(); j != e; ++j) {
865 DISubprogram SP(CountersBySP[j].second);
866 uint32_t FuncChecksum = Funcs.empty() ? 0 : Funcs[j]->getFuncChecksum();
868 EmitFunction, Builder.getInt32(j),
869 Options.FunctionNamesInData ?
870 Builder.CreateGlobalStringPtr(getFunctionName(SP)) :
871 Constant::getNullValue(Builder.getInt8PtrTy()),
872 Builder.getInt32(FuncChecksum),
873 Builder.getInt8(Options.UseCfgChecksum),
874 Builder.getInt32(CfgChecksum));
876 GlobalVariable *GV = CountersBySP[j].first;
878 cast<ArrayType>(GV->getType()->getElementType())->getNumElements();
879 Builder.CreateCall2(EmitArcs,
880 Builder.getInt32(Arcs),
881 Builder.CreateConstGEP2_64(GV, 0, 0));
883 Builder.CreateCall(SummaryInfo);
884 Builder.CreateCall(EndFile);
888 Builder.CreateRetVoid();
892 void GCOVProfiler::insertIndirectCounterIncrement() {
894 cast<Function>(GCOVProfiler::getIncrementIndirectCounterFunc());
895 Fn->setUnnamedAddr(true);
896 Fn->setLinkage(GlobalValue::InternalLinkage);
897 Fn->addFnAttr(Attribute::NoInline);
898 if (Options.NoRedZone)
899 Fn->addFnAttr(Attribute::NoRedZone);
901 // Create basic blocks for function.
902 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", Fn);
903 IRBuilder<> Builder(BB);
905 BasicBlock *PredNotNegOne = BasicBlock::Create(*Ctx, "", Fn);
906 BasicBlock *CounterEnd = BasicBlock::Create(*Ctx, "", Fn);
907 BasicBlock *Exit = BasicBlock::Create(*Ctx, "exit", Fn);
909 // uint32_t pred = *predecessor;
910 // if (pred == 0xffffffff) return;
911 Argument *Arg = Fn->arg_begin();
912 Arg->setName("predecessor");
913 Value *Pred = Builder.CreateLoad(Arg, "pred");
914 Value *Cond = Builder.CreateICmpEQ(Pred, Builder.getInt32(0xffffffff));
915 BranchInst::Create(Exit, PredNotNegOne, Cond, BB);
917 Builder.SetInsertPoint(PredNotNegOne);
919 // uint64_t *counter = counters[pred];
920 // if (!counter) return;
921 Value *ZExtPred = Builder.CreateZExt(Pred, Builder.getInt64Ty());
922 Arg = std::next(Fn->arg_begin());
923 Arg->setName("counters");
924 Value *GEP = Builder.CreateGEP(Arg, ZExtPred);
925 Value *Counter = Builder.CreateLoad(GEP, "counter");
926 Cond = Builder.CreateICmpEQ(Counter,
927 Constant::getNullValue(
928 Builder.getInt64Ty()->getPointerTo()));
929 Builder.CreateCondBr(Cond, Exit, CounterEnd);
932 Builder.SetInsertPoint(CounterEnd);
933 Value *Add = Builder.CreateAdd(Builder.CreateLoad(Counter),
934 Builder.getInt64(1));
935 Builder.CreateStore(Add, Counter);
936 Builder.CreateBr(Exit);
938 // Fill in the exit block.
939 Builder.SetInsertPoint(Exit);
940 Builder.CreateRetVoid();
943 Function *GCOVProfiler::
944 insertFlush(ArrayRef<std::pair<GlobalVariable*, MDNode*> > CountersBySP) {
945 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
946 Function *FlushF = M->getFunction("__llvm_gcov_flush");
948 FlushF = Function::Create(FTy, GlobalValue::InternalLinkage,
949 "__llvm_gcov_flush", M);
951 FlushF->setLinkage(GlobalValue::InternalLinkage);
952 FlushF->setUnnamedAddr(true);
953 FlushF->addFnAttr(Attribute::NoInline);
954 if (Options.NoRedZone)
955 FlushF->addFnAttr(Attribute::NoRedZone);
957 BasicBlock *Entry = BasicBlock::Create(*Ctx, "entry", FlushF);
959 // Write out the current counters.
960 Constant *WriteoutF = M->getFunction("__llvm_gcov_writeout");
961 assert(WriteoutF && "Need to create the writeout function first!");
963 IRBuilder<> Builder(Entry);
964 Builder.CreateCall(WriteoutF);
966 // Zero out the counters.
967 for (ArrayRef<std::pair<GlobalVariable *, MDNode *> >::iterator
968 I = CountersBySP.begin(), E = CountersBySP.end();
970 GlobalVariable *GV = I->first;
971 Constant *Null = Constant::getNullValue(GV->getType()->getElementType());
972 Builder.CreateStore(Null, GV);
975 Type *RetTy = FlushF->getReturnType();
976 if (RetTy == Type::getVoidTy(*Ctx))
977 Builder.CreateRetVoid();
978 else if (RetTy->isIntegerTy())
979 // Used if __llvm_gcov_flush was implicitly declared.
980 Builder.CreateRet(ConstantInt::get(RetTy, 0));
982 report_fatal_error("invalid return type for __llvm_gcov_flush");