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,
50 static cl::opt<bool> DefaultExitBlockBeforeBody("gcov-exit-block-before-body",
51 cl::init(false), cl::Hidden);
53 GCOVOptions GCOVOptions::getDefault() {
55 Options.EmitNotes = true;
56 Options.EmitData = true;
57 Options.UseCfgChecksum = false;
58 Options.NoRedZone = false;
59 Options.FunctionNamesInData = true;
60 Options.ExitBlockBeforeBody = DefaultExitBlockBeforeBody;
62 if (DefaultGCOVVersion.size() != 4) {
63 llvm::report_fatal_error(std::string("Invalid -default-gcov-version: ") +
66 memcpy(Options.Version, DefaultGCOVVersion.c_str(), 4);
73 class GCOVProfiler : public ModulePass {
76 GCOVProfiler() : GCOVProfiler(GCOVOptions::getDefault()) {}
77 GCOVProfiler(const GCOVOptions &Opts) : ModulePass(ID), Options(Opts) {
78 assert((Options.EmitNotes || Options.EmitData) &&
79 "GCOVProfiler asked to do nothing?");
80 ReversedVersion[0] = Options.Version[3];
81 ReversedVersion[1] = Options.Version[2];
82 ReversedVersion[2] = Options.Version[1];
83 ReversedVersion[3] = Options.Version[0];
84 ReversedVersion[4] = '\0';
85 initializeGCOVProfilerPass(*PassRegistry::getPassRegistry());
87 const char *getPassName() const override {
88 return "GCOV Profiler";
92 bool runOnModule(Module &M) override;
94 // Create the .gcno files for the Module based on DebugInfo.
95 void emitProfileNotes();
97 // Modify the program to track transitions along edges and call into the
98 // profiling runtime to emit .gcda files when run.
99 bool emitProfileArcs();
101 // Get pointers to the functions in the runtime library.
102 Constant *getStartFileFunc();
103 Constant *getIncrementIndirectCounterFunc();
104 Constant *getEmitFunctionFunc();
105 Constant *getEmitArcsFunc();
106 Constant *getSummaryInfoFunc();
107 Constant *getDeleteWriteoutFunctionListFunc();
108 Constant *getDeleteFlushFunctionListFunc();
109 Constant *getEndFileFunc();
111 // Create or retrieve an i32 state value that is used to represent the
112 // pred block number for certain non-trivial edges.
113 GlobalVariable *getEdgeStateValue();
115 // Produce a table of pointers to counters, by predecessor and successor
117 GlobalVariable *buildEdgeLookupTable(Function *F,
118 GlobalVariable *Counter,
119 const UniqueVector<BasicBlock *>&Preds,
120 const UniqueVector<BasicBlock*>&Succs);
122 // Add the function to write out all our counters to the global destructor
124 Function *insertCounterWriteout(ArrayRef<std::pair<GlobalVariable*,
126 Function *insertFlush(ArrayRef<std::pair<GlobalVariable*, MDNode*> >);
127 void insertIndirectCounterIncrement();
129 std::string mangleName(DICompileUnit CU, const char *NewStem);
133 // Reversed, NUL-terminated copy of Options.Version.
134 char ReversedVersion[5];
135 // Checksum, produced by hash of EdgeDestinations
136 SmallVector<uint32_t, 4> FileChecksums;
140 SmallVector<std::unique_ptr<GCOVFunction>, 16> Funcs;
144 char GCOVProfiler::ID = 0;
145 INITIALIZE_PASS(GCOVProfiler, "insert-gcov-profiling",
146 "Insert instrumentation for GCOV profiling", false, false)
148 ModulePass *llvm::createGCOVProfilerPass(const GCOVOptions &Options) {
149 return new GCOVProfiler(Options);
152 static StringRef getFunctionName(DISubprogram SP) {
153 if (!SP.getLinkageName().empty())
154 return SP.getLinkageName();
161 static const char *const LinesTag;
162 static const char *const FunctionTag;
163 static const char *const BlockTag;
164 static const char *const EdgeTag;
168 void writeBytes(const char *Bytes, int Size) {
169 os->write(Bytes, Size);
172 void write(uint32_t i) {
173 writeBytes(reinterpret_cast<char*>(&i), 4);
176 // Returns the length measured in 4-byte blocks that will be used to
177 // represent this string in a GCOV file
178 static unsigned lengthOfGCOVString(StringRef s) {
179 // A GCOV string is a length, followed by a NUL, then between 0 and 3 NULs
180 // padding out to the next 4-byte word. The length is measured in 4-byte
181 // words including padding, not bytes of actual string.
182 return (s.size() / 4) + 1;
185 void writeGCOVString(StringRef s) {
186 uint32_t Len = lengthOfGCOVString(s);
188 writeBytes(s.data(), s.size());
190 // Write 1 to 4 bytes of NUL padding.
191 assert((unsigned)(4 - (s.size() % 4)) > 0);
192 assert((unsigned)(4 - (s.size() % 4)) <= 4);
193 writeBytes("\0\0\0\0", 4 - (s.size() % 4));
198 const char *const GCOVRecord::LinesTag = "\0\0\x45\x01";
199 const char *const GCOVRecord::FunctionTag = "\0\0\0\1";
200 const char *const GCOVRecord::BlockTag = "\0\0\x41\x01";
201 const char *const GCOVRecord::EdgeTag = "\0\0\x43\x01";
206 // Constructed only by requesting it from a GCOVBlock, this object stores a
207 // list of line numbers and a single filename, representing lines that belong
209 class GCOVLines : public GCOVRecord {
211 void addLine(uint32_t Line) {
212 assert(Line != 0 && "Line zero is not a valid real line number.");
213 Lines.push_back(Line);
216 uint32_t length() const {
217 // Here 2 = 1 for string length + 1 for '0' id#.
218 return lengthOfGCOVString(Filename) + 2 + Lines.size();
223 writeGCOVString(Filename);
224 for (int i = 0, e = Lines.size(); i != e; ++i)
228 GCOVLines(StringRef F, raw_ostream *os)
235 SmallVector<uint32_t, 32> Lines;
239 // Represent a basic block in GCOV. Each block has a unique number in the
240 // function, number of lines belonging to each block, and a set of edges to
242 class GCOVBlock : public GCOVRecord {
244 GCOVLines &getFile(StringRef Filename) {
245 GCOVLines *&Lines = LinesByFile[Filename];
247 Lines = new GCOVLines(Filename, os);
252 void addEdge(GCOVBlock &Successor) {
253 OutEdges.push_back(&Successor);
258 SmallVector<StringMapEntry<GCOVLines *> *, 32> SortedLinesByFile;
259 for (StringMap<GCOVLines *>::iterator I = LinesByFile.begin(),
260 E = LinesByFile.end(); I != E; ++I) {
261 Len += I->second->length();
262 SortedLinesByFile.push_back(&*I);
265 writeBytes(LinesTag, 4);
269 std::sort(SortedLinesByFile.begin(), SortedLinesByFile.end(),
270 [](StringMapEntry<GCOVLines *> *LHS,
271 StringMapEntry<GCOVLines *> *RHS) {
272 return LHS->getKey() < RHS->getKey();
274 for (SmallVectorImpl<StringMapEntry<GCOVLines *> *>::iterator
275 I = SortedLinesByFile.begin(), E = SortedLinesByFile.end();
277 (*I)->getValue()->writeOut();
283 DeleteContainerSeconds(LinesByFile);
286 GCOVBlock(const GCOVBlock &RHS) : GCOVRecord(RHS), Number(RHS.Number) {
287 // Only allow copy before edges and lines have been added. After that,
288 // there are inter-block pointers (eg: edges) that won't take kindly to
289 // blocks being copied or moved around.
290 assert(LinesByFile.empty());
291 assert(OutEdges.empty());
295 friend class GCOVFunction;
297 GCOVBlock(uint32_t Number, raw_ostream *os)
303 StringMap<GCOVLines *> LinesByFile;
304 SmallVector<GCOVBlock *, 4> OutEdges;
307 // A function has a unique identifier, a checksum (we leave as zero) and a
308 // set of blocks and a map of edges between blocks. This is the only GCOV
309 // object users can construct, the blocks and lines will be rooted here.
310 class GCOVFunction : public GCOVRecord {
312 GCOVFunction(DISubprogram SP, raw_ostream *os, uint32_t Ident,
313 bool UseCfgChecksum, bool ExitBlockBeforeBody)
314 : SP(SP), Ident(Ident), UseCfgChecksum(UseCfgChecksum), CfgChecksum(0),
318 Function *F = SP.getFunction();
319 DEBUG(dbgs() << "Function: " << getFunctionName(SP) << "\n");
322 for (auto &BB : *F) {
323 // Skip index 1 if it's assigned to the ReturnBlock.
324 if (i == 1 && ExitBlockBeforeBody)
326 Blocks.insert(std::make_pair(&BB, GCOVBlock(i++, os)));
328 if (!ExitBlockBeforeBody)
329 ReturnBlock.Number = i;
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);
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 Options.ExitBlockBeforeBody));
518 GCOVFunction &Func = *Funcs.back();
520 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
521 GCOVBlock &Block = Func.getBlock(BB);
522 TerminatorInst *TI = BB->getTerminator();
523 if (int successors = TI->getNumSuccessors()) {
524 for (int i = 0; i != successors; ++i) {
525 Block.addEdge(Func.getBlock(TI->getSuccessor(i)));
527 } else if (isa<ReturnInst>(TI)) {
528 Block.addEdge(Func.getReturnBlock());
532 for (BasicBlock::iterator I = BB->begin(), IE = BB->end();
534 // Debug intrinsic locations correspond to the location of the
535 // declaration, not necessarily any statements or expressions.
536 if (isa<DbgInfoIntrinsic>(I)) continue;
538 const DebugLoc &Loc = I->getDebugLoc();
539 if (Loc.isUnknown()) continue;
541 // Artificial lines such as calls to the global constructors.
542 if (Loc.getLine() == 0) continue;
544 if (Line == Loc.getLine()) continue;
545 Line = Loc.getLine();
546 if (SP != getDISubprogram(Loc.getScope(*Ctx))) continue;
548 GCOVLines &Lines = Block.getFile(SP.getFilename());
549 Lines.addLine(Loc.getLine());
552 EdgeDestinations += Func.getEdgeDestinations();
555 FileChecksums.push_back(hash_value(EdgeDestinations));
556 out.write("oncg", 4);
557 out.write(ReversedVersion, 4);
558 out.write(reinterpret_cast<char*>(&FileChecksums.back()), 4);
560 for (auto &Func : Funcs) {
561 Func->setCfgChecksum(FileChecksums.back());
565 out.write("\0\0\0\0\0\0\0\0", 8); // EOF
570 bool GCOVProfiler::emitProfileArcs() {
571 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
572 if (!CU_Nodes) return false;
575 bool InsertIndCounterIncrCode = false;
576 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
577 DICompileUnit CU(CU_Nodes->getOperand(i));
578 DIArray SPs = CU.getSubprograms();
579 SmallVector<std::pair<GlobalVariable *, MDNode *>, 8> CountersBySP;
580 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
581 DISubprogram SP(SPs.getElement(i));
582 assert((!SP || SP.isSubprogram()) &&
583 "A MDNode in subprograms of a CU should be null or a DISubprogram.");
586 Function *F = SP.getFunction();
588 if (!functionHasLines(F)) continue;
589 if (!Result) Result = true;
591 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
592 TerminatorInst *TI = BB->getTerminator();
593 if (isa<ReturnInst>(TI))
596 Edges += TI->getNumSuccessors();
599 ArrayType *CounterTy =
600 ArrayType::get(Type::getInt64Ty(*Ctx), Edges);
601 GlobalVariable *Counters =
602 new GlobalVariable(*M, CounterTy, false,
603 GlobalValue::InternalLinkage,
604 Constant::getNullValue(CounterTy),
606 CountersBySP.push_back(std::make_pair(Counters, (MDNode*)SP));
608 UniqueVector<BasicBlock *> ComplexEdgePreds;
609 UniqueVector<BasicBlock *> ComplexEdgeSuccs;
612 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
613 TerminatorInst *TI = BB->getTerminator();
614 int Successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
616 if (Successors == 1) {
617 IRBuilder<> Builder(BB->getFirstInsertionPt());
618 Value *Counter = Builder.CreateConstInBoundsGEP2_64(Counters, 0,
620 Value *Count = Builder.CreateLoad(Counter);
621 Count = Builder.CreateAdd(Count, Builder.getInt64(1));
622 Builder.CreateStore(Count, Counter);
623 } else if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
624 IRBuilder<> Builder(BI);
625 Value *Sel = Builder.CreateSelect(BI->getCondition(),
626 Builder.getInt64(Edge),
627 Builder.getInt64(Edge + 1));
628 SmallVector<Value *, 2> Idx;
629 Idx.push_back(Builder.getInt64(0));
631 Value *Counter = Builder.CreateInBoundsGEP(Counters, Idx);
632 Value *Count = Builder.CreateLoad(Counter);
633 Count = Builder.CreateAdd(Count, Builder.getInt64(1));
634 Builder.CreateStore(Count, Counter);
636 ComplexEdgePreds.insert(BB);
637 for (int i = 0; i != Successors; ++i)
638 ComplexEdgeSuccs.insert(TI->getSuccessor(i));
645 if (!ComplexEdgePreds.empty()) {
646 GlobalVariable *EdgeTable =
647 buildEdgeLookupTable(F, Counters,
648 ComplexEdgePreds, ComplexEdgeSuccs);
649 GlobalVariable *EdgeState = getEdgeStateValue();
651 for (int i = 0, e = ComplexEdgePreds.size(); i != e; ++i) {
652 IRBuilder<> Builder(ComplexEdgePreds[i + 1]->getFirstInsertionPt());
653 Builder.CreateStore(Builder.getInt32(i), EdgeState);
656 for (int i = 0, e = ComplexEdgeSuccs.size(); i != e; ++i) {
657 // Call runtime to perform increment.
658 IRBuilder<> Builder(ComplexEdgeSuccs[i+1]->getFirstInsertionPt());
659 Value *CounterPtrArray =
660 Builder.CreateConstInBoundsGEP2_64(EdgeTable, 0,
661 i * ComplexEdgePreds.size());
663 // Build code to increment the counter.
664 InsertIndCounterIncrCode = true;
665 Builder.CreateCall2(getIncrementIndirectCounterFunc(),
666 EdgeState, CounterPtrArray);
671 Function *WriteoutF = insertCounterWriteout(CountersBySP);
672 Function *FlushF = insertFlush(CountersBySP);
674 // Create a small bit of code that registers the "__llvm_gcov_writeout" to
675 // be executed at exit and the "__llvm_gcov_flush" function to be executed
676 // when "__gcov_flush" is called.
677 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
678 Function *F = Function::Create(FTy, GlobalValue::InternalLinkage,
679 "__llvm_gcov_init", M);
680 F->setUnnamedAddr(true);
681 F->setLinkage(GlobalValue::InternalLinkage);
682 F->addFnAttr(Attribute::NoInline);
683 if (Options.NoRedZone)
684 F->addFnAttr(Attribute::NoRedZone);
686 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", F);
687 IRBuilder<> Builder(BB);
689 FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
691 PointerType::get(FTy, 0),
692 PointerType::get(FTy, 0)
694 FTy = FunctionType::get(Builder.getVoidTy(), Params, false);
696 // Initialize the environment and register the local writeout and flush
698 Constant *GCOVInit = M->getOrInsertFunction("llvm_gcov_init", FTy);
699 Builder.CreateCall2(GCOVInit, WriteoutF, FlushF);
700 Builder.CreateRetVoid();
702 appendToGlobalCtors(*M, F, 0);
705 if (InsertIndCounterIncrCode)
706 insertIndirectCounterIncrement();
711 // All edges with successors that aren't branches are "complex", because it
712 // requires complex logic to pick which counter to update.
713 GlobalVariable *GCOVProfiler::buildEdgeLookupTable(
715 GlobalVariable *Counters,
716 const UniqueVector<BasicBlock *> &Preds,
717 const UniqueVector<BasicBlock *> &Succs) {
718 // TODO: support invoke, threads. We rely on the fact that nothing can modify
719 // the whole-Module pred edge# between the time we set it and the time we next
720 // read it. Threads and invoke make this untrue.
722 // emit [(succs * preds) x i64*], logically [succ x [pred x i64*]].
723 size_t TableSize = Succs.size() * Preds.size();
724 Type *Int64PtrTy = Type::getInt64PtrTy(*Ctx);
725 ArrayType *EdgeTableTy = ArrayType::get(Int64PtrTy, TableSize);
727 std::unique_ptr<Constant * []> EdgeTable(new Constant *[TableSize]);
728 Constant *NullValue = Constant::getNullValue(Int64PtrTy);
729 for (size_t i = 0; i != TableSize; ++i)
730 EdgeTable[i] = NullValue;
733 for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
734 TerminatorInst *TI = BB->getTerminator();
735 int Successors = isa<ReturnInst>(TI) ? 1 : TI->getNumSuccessors();
736 if (Successors > 1 && !isa<BranchInst>(TI) && !isa<ReturnInst>(TI)) {
737 for (int i = 0; i != Successors; ++i) {
738 BasicBlock *Succ = TI->getSuccessor(i);
739 IRBuilder<> Builder(Succ);
740 Value *Counter = Builder.CreateConstInBoundsGEP2_64(Counters, 0,
742 EdgeTable[((Succs.idFor(Succ)-1) * Preds.size()) +
743 (Preds.idFor(BB)-1)] = cast<Constant>(Counter);
749 GlobalVariable *EdgeTableGV =
751 *M, EdgeTableTy, true, GlobalValue::InternalLinkage,
752 ConstantArray::get(EdgeTableTy,
753 makeArrayRef(&EdgeTable[0],TableSize)),
754 "__llvm_gcda_edge_table");
755 EdgeTableGV->setUnnamedAddr(true);
759 Constant *GCOVProfiler::getStartFileFunc() {
761 Type::getInt8PtrTy(*Ctx), // const char *orig_filename
762 Type::getInt8PtrTy(*Ctx), // const char version[4]
763 Type::getInt32Ty(*Ctx), // uint32_t checksum
765 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
766 return M->getOrInsertFunction("llvm_gcda_start_file", FTy);
769 Constant *GCOVProfiler::getIncrementIndirectCounterFunc() {
770 Type *Int32Ty = Type::getInt32Ty(*Ctx);
771 Type *Int64Ty = Type::getInt64Ty(*Ctx);
773 Int32Ty->getPointerTo(), // uint32_t *predecessor
774 Int64Ty->getPointerTo()->getPointerTo() // uint64_t **counters
776 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
777 return M->getOrInsertFunction("__llvm_gcov_indirect_counter_increment", FTy);
780 Constant *GCOVProfiler::getEmitFunctionFunc() {
782 Type::getInt32Ty(*Ctx), // uint32_t ident
783 Type::getInt8PtrTy(*Ctx), // const char *function_name
784 Type::getInt32Ty(*Ctx), // uint32_t func_checksum
785 Type::getInt8Ty(*Ctx), // uint8_t use_extra_checksum
786 Type::getInt32Ty(*Ctx), // uint32_t cfg_checksum
788 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
789 return M->getOrInsertFunction("llvm_gcda_emit_function", FTy);
792 Constant *GCOVProfiler::getEmitArcsFunc() {
794 Type::getInt32Ty(*Ctx), // uint32_t num_counters
795 Type::getInt64PtrTy(*Ctx), // uint64_t *counters
797 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
798 return M->getOrInsertFunction("llvm_gcda_emit_arcs", FTy);
801 Constant *GCOVProfiler::getSummaryInfoFunc() {
802 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
803 return M->getOrInsertFunction("llvm_gcda_summary_info", FTy);
806 Constant *GCOVProfiler::getDeleteWriteoutFunctionListFunc() {
807 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
808 return M->getOrInsertFunction("llvm_delete_writeout_function_list", FTy);
811 Constant *GCOVProfiler::getDeleteFlushFunctionListFunc() {
812 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
813 return M->getOrInsertFunction("llvm_delete_flush_function_list", FTy);
816 Constant *GCOVProfiler::getEndFileFunc() {
817 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
818 return M->getOrInsertFunction("llvm_gcda_end_file", FTy);
821 GlobalVariable *GCOVProfiler::getEdgeStateValue() {
822 GlobalVariable *GV = M->getGlobalVariable("__llvm_gcov_global_state_pred");
824 GV = new GlobalVariable(*M, Type::getInt32Ty(*Ctx), false,
825 GlobalValue::InternalLinkage,
826 ConstantInt::get(Type::getInt32Ty(*Ctx),
828 "__llvm_gcov_global_state_pred");
829 GV->setUnnamedAddr(true);
834 Function *GCOVProfiler::insertCounterWriteout(
835 ArrayRef<std::pair<GlobalVariable *, MDNode *> > CountersBySP) {
836 FunctionType *WriteoutFTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
837 Function *WriteoutF = M->getFunction("__llvm_gcov_writeout");
839 WriteoutF = Function::Create(WriteoutFTy, GlobalValue::InternalLinkage,
840 "__llvm_gcov_writeout", M);
841 WriteoutF->setUnnamedAddr(true);
842 WriteoutF->addFnAttr(Attribute::NoInline);
843 if (Options.NoRedZone)
844 WriteoutF->addFnAttr(Attribute::NoRedZone);
846 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", WriteoutF);
847 IRBuilder<> Builder(BB);
849 Constant *StartFile = getStartFileFunc();
850 Constant *EmitFunction = getEmitFunctionFunc();
851 Constant *EmitArcs = getEmitArcsFunc();
852 Constant *SummaryInfo = getSummaryInfoFunc();
853 Constant *EndFile = getEndFileFunc();
855 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
857 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
858 DICompileUnit CU(CU_Nodes->getOperand(i));
859 std::string FilenameGcda = mangleName(CU, "gcda");
860 uint32_t CfgChecksum = FileChecksums.empty() ? 0 : FileChecksums[i];
861 Builder.CreateCall3(StartFile,
862 Builder.CreateGlobalStringPtr(FilenameGcda),
863 Builder.CreateGlobalStringPtr(ReversedVersion),
864 Builder.getInt32(CfgChecksum));
865 for (unsigned j = 0, e = CountersBySP.size(); j != e; ++j) {
866 DISubprogram SP(CountersBySP[j].second);
867 uint32_t FuncChecksum = Funcs.empty() ? 0 : Funcs[j]->getFuncChecksum();
869 EmitFunction, Builder.getInt32(j),
870 Options.FunctionNamesInData ?
871 Builder.CreateGlobalStringPtr(getFunctionName(SP)) :
872 Constant::getNullValue(Builder.getInt8PtrTy()),
873 Builder.getInt32(FuncChecksum),
874 Builder.getInt8(Options.UseCfgChecksum),
875 Builder.getInt32(CfgChecksum));
877 GlobalVariable *GV = CountersBySP[j].first;
879 cast<ArrayType>(GV->getType()->getElementType())->getNumElements();
880 Builder.CreateCall2(EmitArcs,
881 Builder.getInt32(Arcs),
882 Builder.CreateConstGEP2_64(GV, 0, 0));
884 Builder.CreateCall(SummaryInfo);
885 Builder.CreateCall(EndFile);
889 Builder.CreateRetVoid();
893 void GCOVProfiler::insertIndirectCounterIncrement() {
895 cast<Function>(GCOVProfiler::getIncrementIndirectCounterFunc());
896 Fn->setUnnamedAddr(true);
897 Fn->setLinkage(GlobalValue::InternalLinkage);
898 Fn->addFnAttr(Attribute::NoInline);
899 if (Options.NoRedZone)
900 Fn->addFnAttr(Attribute::NoRedZone);
902 // Create basic blocks for function.
903 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", Fn);
904 IRBuilder<> Builder(BB);
906 BasicBlock *PredNotNegOne = BasicBlock::Create(*Ctx, "", Fn);
907 BasicBlock *CounterEnd = BasicBlock::Create(*Ctx, "", Fn);
908 BasicBlock *Exit = BasicBlock::Create(*Ctx, "exit", Fn);
910 // uint32_t pred = *predecessor;
911 // if (pred == 0xffffffff) return;
912 Argument *Arg = Fn->arg_begin();
913 Arg->setName("predecessor");
914 Value *Pred = Builder.CreateLoad(Arg, "pred");
915 Value *Cond = Builder.CreateICmpEQ(Pred, Builder.getInt32(0xffffffff));
916 BranchInst::Create(Exit, PredNotNegOne, Cond, BB);
918 Builder.SetInsertPoint(PredNotNegOne);
920 // uint64_t *counter = counters[pred];
921 // if (!counter) return;
922 Value *ZExtPred = Builder.CreateZExt(Pred, Builder.getInt64Ty());
923 Arg = std::next(Fn->arg_begin());
924 Arg->setName("counters");
925 Value *GEP = Builder.CreateGEP(Arg, ZExtPred);
926 Value *Counter = Builder.CreateLoad(GEP, "counter");
927 Cond = Builder.CreateICmpEQ(Counter,
928 Constant::getNullValue(
929 Builder.getInt64Ty()->getPointerTo()));
930 Builder.CreateCondBr(Cond, Exit, CounterEnd);
933 Builder.SetInsertPoint(CounterEnd);
934 Value *Add = Builder.CreateAdd(Builder.CreateLoad(Counter),
935 Builder.getInt64(1));
936 Builder.CreateStore(Add, Counter);
937 Builder.CreateBr(Exit);
939 // Fill in the exit block.
940 Builder.SetInsertPoint(Exit);
941 Builder.CreateRetVoid();
944 Function *GCOVProfiler::
945 insertFlush(ArrayRef<std::pair<GlobalVariable*, MDNode*> > CountersBySP) {
946 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
947 Function *FlushF = M->getFunction("__llvm_gcov_flush");
949 FlushF = Function::Create(FTy, GlobalValue::InternalLinkage,
950 "__llvm_gcov_flush", M);
952 FlushF->setLinkage(GlobalValue::InternalLinkage);
953 FlushF->setUnnamedAddr(true);
954 FlushF->addFnAttr(Attribute::NoInline);
955 if (Options.NoRedZone)
956 FlushF->addFnAttr(Attribute::NoRedZone);
958 BasicBlock *Entry = BasicBlock::Create(*Ctx, "entry", FlushF);
960 // Write out the current counters.
961 Constant *WriteoutF = M->getFunction("__llvm_gcov_writeout");
962 assert(WriteoutF && "Need to create the writeout function first!");
964 IRBuilder<> Builder(Entry);
965 Builder.CreateCall(WriteoutF);
967 // Zero out the counters.
968 for (ArrayRef<std::pair<GlobalVariable *, MDNode *> >::iterator
969 I = CountersBySP.begin(), E = CountersBySP.end();
971 GlobalVariable *GV = I->first;
972 Constant *Null = Constant::getNullValue(GV->getType()->getElementType());
973 Builder.CreateStore(Null, GV);
976 Type *RetTy = FlushF->getReturnType();
977 if (RetTy == Type::getVoidTy(*Ctx))
978 Builder.CreateRetVoid();
979 else if (RetTy->isIntegerTy())
980 // Used if __llvm_gcov_flush was implicitly declared.
981 Builder.CreateRet(ConstantInt::get(RetTy, 0));
983 report_fatal_error("invalid return type for __llvm_gcov_flush");